@article {pmid37242644, year = {2023}, author = {Costa-Orlandi, CB and Bila, NM and Bonatti, JLC and Vaso, CO and Santos, MB and Polaquini, CR and Santoni Biasioli, MM and Herculano, RD and Regasini, LO and Fusco-Almeida, AM and Mendes-Giannini, MJS}, title = {Membranolytic Activity Profile of Nonyl 3,4-Dihydroxybenzoate: A New Anti-Biofilm Compound for the Treatment of Dermatophytosis.}, journal = {Pharmaceutics}, volume = {15}, number = {5}, pages = {}, pmid = {37242644}, issn = {1999-4923}, abstract = {The ability of dermatophytes to live in communities and resist antifungal drugs may explain treatment recurrence, especially in onychomycosis. Therefore, new molecules with reduced toxicity that target dermatophyte biofilms should be investigated. This study evaluated nonyl 3,4-dihydroxybenzoate (nonyl) susceptibility and mechanism of action on planktonic cells and biofilms of T. rubrum and T. mentagrophytes. Metabolic activities, ergosterol, and reactive oxygen species (ROS) were quantified, and the expression of genes encoding ergosterol was determined by real-time PCR. The effects on the biofilm structure were visualized using confocal electron microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). T. rubrum and T. mentagrophytes biofilms were susceptible to nonyl and resistant to fluconazole, griseofulvin (all strains), and terbinafine (two strains). The SEM results revealed that nonyl groups seriously damaged the biofilms, whereas synthetic drugs caused little or no damage and, in some cases, stimulated the development of resistance structures. Confocal microscopy showed a drastic reduction in biofilm thickness, and transmission electron microscopy results indicated that the compound promoted the derangement and formation of pores in the plasma membrane. Biochemical and molecular assays indicated that fungal membrane ergosterol is a nonyl target. These findings show that nonyl 3,4-dihydroxybenzoate is a promising antifungal compound.}, }
@article {pmid37242643, year = {2023}, author = {Almasri, D and Dahman, Y}, title = {Prosthetic Joint Infections: Biofilm Formation, Management, and the Potential of Mesoporous Bioactive Glass as a New Treatment Option.}, journal = {Pharmaceutics}, volume = {15}, number = {5}, pages = {}, doi = {10.3390/pharmaceutics15051401}, pmid = {37242643}, issn = {1999-4923}, abstract = {Infection of prosthetic joints is one of the biggest challenges to a successful replacement of the joint after a total joint arthroplasty. Such infections are caused by bacterial colonies that are difficult to treat by systemic delivery of antibiotics. Local delivery of antibiotics can prove to be the solution to such a devastating outcome that impacts patients' health and ability to regain function in their joints as well as costs the healthcare system millions of dollars every year. This review will discuss prosthetic joint infections in detail with a focus on the development, management, and diagnosis of the infections. Surgeons often opt to use polymethacrylate cement locally to deliver antibiotics; however, due to the rapid release of antibiotics, non-biodegradability, and high chance of reinfection, the search for alternatives is in high demand. One of the most researched alternatives to current treatments is the use of biodegradable and highly compatible bioactive glass. The novelty of this review lies in its focus on mesoporous bioactive glass as a potential alternative to current treatments for prosthetic joint infection. Mesoporous bioactive glass is the focus of this review because it has a higher capacity to deliver biomolecules, stimulate bone growth, and treat infections after prosthetic joint replacement surgeries. The review also examines different synthesis methods, compositions, and properties of mesoporous bioactive glass, highlighting its potential as a biomaterial for the treatment of joint infections.}, }
@article {pmid37242528, year = {2023}, author = {Abudalu, M and Aqawi, M and Sionov, RV and Friedman, M and Gati, I and Munz, Y and Ohana, G and Steinberg, D}, title = {Polyglactin 910 Meshes Coated with Sustained-Release Cannabigerol Varnish Inhibit Staphylococcus aureus Biofilm Formation and Macrophage Cytokine Secretion: An In Vitro Study.}, journal = {Pharmaceuticals (Basel, Switzerland)}, volume = {16}, number = {5}, pages = {}, doi = {10.3390/ph16050745}, pmid = {37242528}, issn = {1424-8247}, abstract = {Synthetic surgical meshes are commonly used in abdominal wall reconstruction surgeries to strengthen a weak abdominal wall. Common mesh-related complications include local infection and inflammatory processes. Because cannabigerol (CBG) has both antibacterial and anti-inflammatory properties, we proposed that coating VICRYL (polyglactin 910) mesh with a sustained-release varnish (SRV) containing CBG would prevent these complications. We used an in vitro infection model with Staphylococcus aureus and an in vitro inflammation model of lipopolysaccharide (LPS)-stimulated macrophages. Meshes coated with either SRV-placebo or SRV-CBG were exposed daily to S. aureus in tryptic soy medium (TSB) or macrophage Dulbecco's modified eagle medium (DMEM). Bacterial growth and biofilm formation in the environment and on the meshes were assessed by changes in optical density, bacterial ATP content, metabolic activity, crystal violet staining, spinning disk confocal microscopy (SDCM), and high-resolution scanning electron microscopy (HR-SEM). The anti-inflammatory effect of the culture medium that was exposed daily to the coated meshes was analyzed by measuring the release of the cytokines IL-6 and IL-10 from LPS-stimulated RAW 264.7 macrophages with appropriate ELISA kits. Additionally, a cytotoxicity assay was performed on Vero epithelial cell lines. We observed that compared with SRV-placebo, the segments coated with SRV-CBG inhibited the bacterial growth of S. aureus in the mesh environment for 9 days by 86 ± 4% and prevented biofilm formation and metabolic activity in the surroundings for 9 days, with respective 70 ± 2% and 95 ± 0.2% reductions. The culture medium that was incubated with the SRV-CBG-coated mesh inhibited LPS-induced secretion of IL-6 and IL-10 from the RAW 264.7 macrophages for up to 6 days without affecting macrophage viability. A partial anti-inflammatory effect was also observed with SRV-placebo. The conditioned culture medium was not toxic to Vero epithelial cells, which had an IC50 of 25 µg/mL for CBG. In conclusion, our data indicate a potential role of coating VICRYL mesh with SRV-CBG in preventing infection and inflammation in the initial period after surgery.}, }
@article {pmid37242523, year = {2023}, author = {Leesombun, A and Sungpradit, S and Bangphoomi, N and Thongjuy, O and Wechusdorn, J and Riengvirodkij, S and Wannawong, J and Boonmasawai, S}, title = {Effects of Piper betle Extracts against Biofilm Formation by Methicillin-Resistant Staphylococcus pseudintermedius Isolated from Dogs.}, journal = {Pharmaceuticals (Basel, Switzerland)}, volume = {16}, number = {5}, pages = {}, doi = {10.3390/ph16050741}, pmid = {37242523}, issn = {1424-8247}, abstract = {Emergence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolated from dogs with cutaneous and wound infections has significantly impacted veterinary medicine. This study aimed to isolate S. pseudintermedius from canine pyoderma and investigate the effects of ethanolic extracts of Piper betle (PB), P. sarmentosum (PS), and P. nigrum (PN) on the bacterial growth and biofilm formation of S. pseudintermedius and MRSP. Of the isolated 152 isolates, 53 were identified as S. pseudintermedius using polymerase chain reaction, and 10 isolates (6.58%) were identified as MRSP based on the presence of mecA. Based on phenotype, 90% of MRSPs were multidrug-resistant. All MRSP had moderate (10%, 1/10) and strong (90%, 9/10) biofilm production ability. PB extracts were the most effective in inhibiting planktonic cells, and the minimum inhibitory concentration at which ≥50% of the isolates were inhibited (MIC50) was 256 µg/mL (256-1024 µg/mL) for S. pseudintermedius isolates and 512 µg/mL (256-1024 µg/mL) for MRSP isolates. The MIC90 for S. pseudintermedius and MRSP was 512 µg/mL. In XTT assay, PB at 4× MIC showed an inhibition rate of 39.66-68.90% and 45.58-59.13% for S. pseudintermedius and MRSP, respectively, in inhibiting biofilm formation. For PB at 8× MIC, the inhibition rates for S. pseudintermedius and MRSP were 50.74-81.66% and 59.57-78.33%, respectively. Further, 18 compounds were identified in PB using gas chromatography-mass spectrometry, and hydroxychavicol (36.02%) was the major constituent. These results indicated that PB could inhibit bacteria growth of and biofilm formation by S. pseudintermedius and MRSP isolated from canine pyoderma in a concentration-dependent manner. Therefore, PB is a potential candidate for the treatment of MRSP infection and biofilm formation in veterinary medicine.}, }
@article {pmid37241392, year = {2023}, author = {Ścibik, &#x141; and Ochońska, D and Gołda-Cępa, M and Kwiecień, K and Pamuła, E and Kotarba, A and Brzychczy-Włoch, M}, title = {Sonochemical Deposition of Gentamicin Nanoparticles at the PCV Tracheostomy Tube Surface Limiting Bacterial Biofilm Formation.}, journal = {Materials (Basel, Switzerland)}, volume = {16}, number = {10}, pages = {}, doi = {10.3390/ma16103765}, pmid = {37241392}, issn = {1996-1944}, abstract = {BACKGROUND: The use of nanotechnology in the production of medical equipment has opened new possibilities to fight bacterial biofilm developing on their surfaces, which can cause infectious complications. In this study, we decided to use gentamicin nanoparticles. An ultrasonic technique was used for their synthesis and immediate deposition onto the surface of tracheostomy tubes, and their effect on bacterial biofilm formation was evaluated.<br><br>METHODS: Polyvinyl chloride was functionalized using oxygen plasma followed by sonochemical formation and the embedment of gentamicin nanoparticles. The resulting surfaces were characterized with the use of AFM, WCA, NTA, FTIR and evaluated for cytotoxicity with the use of A549 cell line and for bacterial adhesion using reference strains of S. aureus (ATCC[&#xae;] 25923&#x2122;) and E. coli (ATCC[&#xae;] 25922&#x2122;).<br><br>RESULTS: The use of gentamicin nanoparticles significantly reduced the adhesion of bacterial colonies on the surface of the tracheostomy tube for S. aureus from 6 &#xd7; 10[5] CFU/mL to 5 &#xd7; 10[3] CFU/mL and for E. coli from 1.655 &#xd7; 10[5] CFU/mL to 2 &#xd7; 10[1] CFU/mL, and the functionalized surfaces did not show a cytotoxic effect on A549 cells (ATTC CCL 185).<br><br>CONCLUSIONS: The use of gentamicin nanoparticles on the polyvinyl chloride surface may be an additional supporting method for patients after tracheostomy in order to prevent the colonization of the biomaterial by potentially pathogenic microorganisms.}, }
@article {pmid37241277, year = {2023}, author = {Vladkova, TG and Staneva, AD and Avramova, IA and Ivanova, IA and Gospodinova, DN}, title = {Fucoidan-Containing, Low-Adhesive Siloxane Coatings for Medical Applications: Inhibition of Bacterial Growth and Biofilm Development.}, journal = {Materials (Basel, Switzerland)}, volume = {16}, number = {10}, pages = {}, doi = {10.3390/ma16103651}, pmid = {37241277}, issn = {1996-1944}, abstract = {The deposition of low-adhesive siloxane coatings is a current trend for the non-toxic control of bacterial growth and biofilm formation. Total elimination of biofilm formation has not been reported so far. The aim of this investigation was to study the ability of a non-toxic, natural, biologically active substance, such as fucoidan, to inhibit bacterial growth on similar medical coatings. The fucoidan amount was varied, and its impact on the bioadhesion-influencing surface characteristics, as well as on bacterial cell growth, was investigated. The inclusion of up to 3-4 wt.% brown algae-derived fucoidan in the coatings increases their inhibitory effect, more significantly on the Gram-positive bacterium S. aureus than on the Gram-negative bacterium Escherichia coli. The biological activity of the studied siloxane coatings was ascribed to the formation of a low-adhesive, biologically active surface top layer consisting of siloxane oil and dispersed water-soluble fucoidan particles. This is the first report on the antibacterial activity of fucoidan-containing medical siloxane coatings. The experimental results give reason to expect that relevantly selected, natural biologically active substances can be efficient in the non-toxic control of bacterial growth on medical devices and, as a result, medical device-associated infections.}, }
@article {pmid37240199, year = {2023}, author = {Ma, X and Liu, H and Liu, Z and Wang, Y and Zhong, Z and Peng, G and Gu, Y}, title = {Trichosporon asahii PLA2 Gene Enhances Drug Resistance to Azoles by Improving Drug Efflux and Biofilm Formation.}, journal = {International journal of molecular sciences}, volume = {24}, number = {10}, pages = {}, doi = {10.3390/ijms24108855}, pmid = {37240199}, issn = {1422-0067}, abstract = {Trichosporon asahii is an opportunistic pathogen that can cause severe or even fatal infections in patients with low immune function. sPLA2 plays different roles in different fungi and is also related to fungal drug resistance. However, the mechanism underlying its drug resistance to azoles has not yet been reported in T. asahii. Therefore, we investigated the drug resistance of T. asahii PLA2 (TaPLA2) by constructing overexpressing mutant strains (TaPLA2[OE]). TaPLA2[OE] was generated by homologous recombination of the recombinant vector pEGFP-N1-TaPLA2, induced by the CMV promoter, with Agrobacterium tumefaciens. The structure of the protein was found to be typical of sPLA2, and it belongs to the phospholipase A2_3 superfamily. TaPLA2[OE] enhanced antifungal drug resistance by upregulating the expression of effector genes and increasing the number of arthrospores to promote biofilm formation. TaPLA2[OE] was highly sensitive to sodium dodecyl sulfate and Congo red, indicating impaired cell wall integrity due to downregulation of chitin synthesis or degradation genes, which can indirectly affect fungal resistance. In conclusion, TaPLA2 overexpression enhanced the resistance to azoles of T. asahii by enhancing drug efflux and biofilm formation and upregulating HOG-MAPK pathway genes; therefore, it has promising research prospects.}, }
@article {pmid37240055, year = {2023}, author = {Chung, J and Eisha, S and Park, S and Morris, AJ and Martin, I}, title = {How Three Self-Secreted Biofilm Exopolysaccharides of Pseudomonas aeruginosa, Psl, Pel, and Alginate, Can Each Be Exploited for Antibiotic Adjuvant Effects in Cystic Fibrosis Lung Infection.}, journal = {International journal of molecular sciences}, volume = {24}, number = {10}, pages = {}, doi = {10.3390/ijms24108709}, pmid = {37240055}, issn = {1422-0067}, abstract = {In cystic fibrosis (CF), pulmonary infection with Pseudomonas aeruginosa is a cause of increased morbidity and mortality, especially in patients for whom infection becomes chronic and there is reliance on long-term suppressive therapies. Current antimicrobials, though varied mechanistically and by mode of delivery, are inadequate not only due to their failure to eradicate infection but also because they do not halt the progression of lung function decline over time. One of the reasons for this failure is thought to be the biofilm mode of growth of P. aeruginosa, wherein self-secreted exopolysaccharides (EPSs) provide physical protection against antibiotics and an array of niches with resulting metabolic and phenotypic heterogeneity. The three biofilm-associated EPSs secreted by P. aeruginosa (alginate, Psl, and Pel) are each under investigation and are being exploited in ways that potentiate antibiotics. In this review, we describe the development and structure of P. aeruginosa biofilms before examining each EPS as a potential therapeutic target for combating pulmonary infection with P. aeruginosa in CF, with a particular focus on the current evidence for these emerging therapies and barriers to bringing these therapies into clinic.}, }
@article {pmid37239957, year = {2023}, author = {Su, X and Cui, H and Zhang, W}, title = {Copiotrophy in a Marine-Biofilm-Derived Roseobacteraceae Bacterium Can Be Supported by Amino Acid Metabolism and Thiosulfate Oxidation.}, journal = {International journal of molecular sciences}, volume = {24}, number = {10}, pages = {}, doi = {10.3390/ijms24108617}, pmid = {37239957}, issn = {1422-0067}, abstract = {Copiotrophic bacteria that respond rapidly to nutrient availability, particularly high concentrations of carbon sources, play indispensable roles in marine carbon cycling. However, the molecular and metabolic mechanisms governing their response to carbon concentration gradients are not well understood. Here, we focused on a new member of the family Roseobacteraceae isolated from coastal marine biofilms and explored the growth strategy at different carbon concentrations. When cultured in a carbon-rich medium, the bacterium grew to significantly higher cell densities than Ruegeria pomeroyi DSS-3, although there was no difference when cultured in media with reduced carbon. Genomic analysis showed that the bacterium utilized various pathways involved in biofilm formation, amino acid metabolism, and energy production via the oxidation of inorganic sulfur compounds. Transcriptomic analysis indicated that 28.4% of genes were regulated by carbon concentration, with increased carbon concentration inducing the expression of key enzymes in the EMP, ED, PP, and TCA cycles, genes responsible for the transformation of amino acids into TCA intermediates, as well as the sox genes for thiosulfate oxidation. Metabolomics showed that amino acid metabolism was enhanced and preferred in the presence of a high carbon concentration. Mutation of the sox genes decreased cell proton motive force when grown with amino acids and thiosulfate. In conclusion, we propose that copiotrophy in this Roseobacteraceae bacterium can be supported by amino acid metabolism and thiosulfate oxidation.}, }
@article {pmid37237796, year = {2023}, author = {Arumugam, M and Manikandan, DB and Marimuthu, SK and Muthusamy, G and Kari, ZA and Téllez-Isaías, G and Ramasamy, T}, title = {Evaluating Biofilm Inhibitory Potential in Fish Pathogen, Aeromonas hydrophila by Agricultural Waste Extracts and Assessment of Aerolysin Inhibitors Using In Silico Approach.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {5}, pages = {}, doi = {10.3390/antibiotics12050891}, pmid = {37237796}, issn = {2079-6382}, abstract = {Aeromonas hydrophila, an opportunistic bacteria, causes several devastating diseases in humans and animals, particularly aquatic species. Antibiotics have been constrained by the rise of antibiotic resistance caused by drug overuse. Therefore, new strategies are required to prevent appropriate antibiotic inability from antibiotic-resistant strains. Aerolysin is essential for A. hydrophila pathogenesis and has been proposed as a potential target for inventing drugs with anti-virulence properties. It is a unique method of disease prevention in fish to block the quorum-sensing mechanism of A. hydrophila. In SEM analysis, the crude solvent extracts of both groundnut shells and black gram pods exhibited a reduction of aerolysin formation and biofilm matrix formation by blocking the QS in A. hydrophila. Morphological changes were identified in the extracts treated bacterial cells. Furthermore, in previous studies, 34 ligands were identified with potential antibacterial metabolites from agricultural wastes, groundnut shells, and black gram pods using a literature survey. Twelve potent metabolites showed interactions between aerolysin and metabolites during molecular docking analysis, in that H-Pyran-4-one-2,3 dihydro-3,5 dihydroxy-6-methyl (-5.3 kcal/mol) and 2-Hexyldecanoic acid (-5.2 kcal/mol) showed promising results with potential hydrogen bond interactions with aerolysin. These metabolites showed a better binding affinity with aerolysin for 100 ns in molecular simulation dynamics. These findings point to a novel strategy for developing drugs using metabolites from agricultural wastes that may be feasible pharmacological solutions for treating A. hydrophila infections for the betterment of aquaculture.}, }
@article {pmid37237778, year = {2023}, author = {Makhlouf, Z and Ali, AA and Al-Sayah, MH}, title = {Liposomes-Based Drug Delivery Systems of Anti-Biofilm Agents to Combat Bacterial Biofilm Formation.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {5}, pages = {}, doi = {10.3390/antibiotics12050875}, pmid = {37237778}, issn = {2079-6382}, abstract = {All currently approved antibiotics are being met by some degree of resistance by the bacteria they target. Biofilm formation is one of the crucial enablers of bacterial resistance, making it an important bacterial process to target for overcoming antibiotic resistance. Accordingly, several drug delivery systems that target biofilm formation have been developed. One of these systems is based on lipid-based nanocarriers (liposomes), which have shown strong efficacy against biofilms of bacterial pathogens. Liposomes come in various types, namely conventional (charged or neutral), stimuli-responsive, deformable, targeted, and stealth. This paper reviews studies employing liposomal formulations against biofilms of medically salient gram-negative and gram-positive bacterial species reported recently. When it comes to gram-negative species, liposomal formulations of various types were reported to be efficacious against Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, and members of the genera Klebsiella, Salmonella, Aeromonas, Serratia, Porphyromonas, and Prevotella. A range of liposomal formulations were also effective against gram-positive biofilms, including mostly biofilms of Staphylococcal strains, namely Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus saprophyticus subspecies bovis, followed by Streptococcal strains (pneumonia, oralis, and mutans), Cutibacterium acnes, Bacillus subtilis, Mycobacterium avium, Mycobacterium avium subsp. hominissuis, Mycobacterium abscessus, and Listeria monocytogenes biofilms. This review outlines the benefits and limitations of using liposomal formulations as means to combat different multidrug-resistant bacteria, urging the investigation of the effects of bacterial gram-stain on liposomal efficiency and the inclusion of pathogenic bacterial strains previously unstudied.}, }
@article {pmid37237774, year = {2023}, author = {Neidhöfer, C and Rathore, K and Parčina, M and Sieber, MA}, title = {ESKAPEE Pathogen Biofilm Control on Surfaces with Probiotic Lactobacillaceae and Bacillus species.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {5}, pages = {}, doi = {10.3390/antibiotics12050871}, pmid = {37237774}, issn = {2079-6382}, abstract = {Combatting the rapidly growing threat of antimicrobial resistance and reducing prevalence and transmission of ESKAPEE pathogens in healthcare settings requires innovative strategies, one of which is displacing these pathogens using beneficial microorganisms. Our review comprehensively examines the evidence of probiotic bacteria displacing ESKAPEE pathogens, with a focus on inanimate surfaces. A systematic search was conducted using the PubMed and Web of Science databases on 21 December 2021, and 143 studies were identified examining the effects of Lactobacillaceae and Bacillus spp. cells and products on the growth, colonization, and survival of ESKAPEE pathogens. While the diversity of study methods limits evidence analysis, results presented by narrative synthesis demonstrate that several species have the potential as cells or their products or supernatants to displace nosocomial infection-causing organisms in a variety of in vitro and in vivo settings. Our review aims to aid the development of new promising approaches to control pathogen biofilms in medical settings by informing researchers and policymakers about the potential of probiotics to combat nosocomial infections. More targeted studies are needed to assess safety and efficacy of different probiotic formulations, followed by large-scale studies to assess utility in infection control and medical practice.}, }
@article {pmid37237757, year = {2023}, author = {Hwang, HJ and Li, DD and Lee, J and Kang, MK and Moon, HR and Lee, JH}, title = {Compounds That Have an Anti-Biofilm Effect against Common Bacteria at Very Low Concentrations and Their Antibiotic Combination Effect.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {5}, pages = {}, doi = {10.3390/antibiotics12050853}, pmid = {37237757}, issn = {2079-6382}, abstract = {Two synthetic compounds, MHY1383, azo-resveratrol and MHY1387, 5-[4-hydroxy-3,5-methoxybenzy]-2-thioxodihydropyrimidine-4,6[1H,5H]-dione have been reported to have an anti-biofilm effect on Pseudomonas aeruginosa at very low concentrations (1-10 pM). Here, we investigated the anti-biofilm effects of these compounds in various bacteria. We found that MHY1383 significantly inhibited Escherichia coli, Bacillus subtilis, and Staphylococcus aureus biofilm formation at 1 pM, 1 nM, and 10 nM, respectively. MHY1387 also inhibited the biofilm formation of E. coli, B. subtilis, and S. aureus at 1 pM, 10 nM, and 100 pM, respectively. Both MHY1383 and MHY1387 showed medium-dependent anti-biofilm effects on Salmonella enterica at high concentrations (10 μM). We also tested the susceptibility to antibiotics by measuring the minimum inhibitory concentration (MIC) in various bacteria. When P. aeruginosa, E. coli, B. subtilis, S. enterica, and S. aureus were treated with MHY1383 or MHY1387 in combination with four different antibiotics, the MICs of carbenicillin against B. subtilis and S. aureus were lowered more than two-fold by the combination with MHY1387. However, in all other combinations, the MIC changed within two-fold. The results of this study suggest that MHY1383 and MHY1387 are effective anti-biofilm agents and can be used at very low concentrations against biofilms formed by various types of bacteria. We also suggest that even if a substance that inhibits biofilm is used together with antibiotics, it does not necessarily have the effect of lowering the MIC of the antibiotics.}, }
@article {pmid37237748, year = {2023}, author = {Martínez, A and Stashenko, EE and Sáez, RT and Zafra, G and Ortiz, C}, title = {Effect of Essential Oil from Lippia origanoides on the Transcriptional Expression of Genes Related to Quorum Sensing, Biofilm Formation, and Virulence of Escherichia coli and Staphylococcus aureus.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {5}, pages = {}, doi = {10.3390/antibiotics12050845}, pmid = {37237748}, issn = {2079-6382}, abstract = {Microbial infections resistant to conventional antibiotics constitute one of the most important causes of mortality in the world. In some bacterial species, such as Escherichia coli and Staphylococcus aureus pathogens, biofilm formation can favor their antimicrobial resistance. These biofilm-forming bacteria produce a compact and protective matrix, allowing their adherence and colonization to different surfaces, and contributing to resistance, recurrence, and chronicity of the infections. Therefore, different therapeutic alternatives have been investigated to interrupt both cellular communication routes and biofilm formation. Among these, essential oils (EO) from Lippia origanoides thymol-carvacrol II chemotype (LOTC II) plants have demonstrated biological activity against different biofilm-forming pathogenic bacteria. In this work, we determined the effect of LOTC II EO on the expression of genes associated with quorum sensing (QS) communication, biofilm formation, and virulence of E. coli ATCC 25922 and S. aureus ATCC 29213. This EO was found to have high efficacy against biofilm formation, decreasing-by negative regulation-the expression of genes involved in motility (fimH), adherence and cellular aggregation (csgD), and exopolysaccharide production (pgaC) in E. coli. In addition, this effect was also determined in S. aureus where the L. origanoides EO diminished the expression of genes involved in QS communication (agrA), production of exopolysaccharides by PIA/PNG (icaA), synthesis of alpha hemolysin (hla), transcriptional regulators of the production of extracellular toxins (RNA III), QS and biofilm formation transcriptional regulators (sarA) and global regulators of biofilm formation (rbf and aur). Positive regulation was observed on the expression of genes encoding inhibitors of biofilm formation (e.g., sdiA and ariR). These findings suggest that LOTCII EO can affect biological pathways associated with QS communication, biofilm formation, and virulence of E. coli and S. aureus at subinhibitory concentrations and could be a promising candidate as a natural antibacterial alternative to conventional antibiotics.}, }
@article {pmid37237611, year = {2023}, author = {Kurow, O and Nuwayhid, R and Stock, P and Steinert, M and Langer, S and Krämer, S and Metelmann, IB}, title = {Organotypic 3D Co-Culture of Human Pleura as a Novel In Vitro Model of Staphylococcus aureus Infection and Biofilm Development.}, journal = {Bioengineering (Basel, Switzerland)}, volume = {10}, number = {5}, pages = {}, doi = {10.3390/bioengineering10050537}, pmid = {37237611}, issn = {2306-5354}, abstract = {Bacterial pleural infections are associated with high mortality. Treatment is complicated due to biofilm formation. A common causative pathogen is Staphylococcus aureus (S. aureus). Since it is distinctly human-specific, rodent models do not provide adequate conditions for research. The purpose of this study was to examine the effects of S. aureus infection on human pleural mesothelial cells using a recently established 3D organotypic co-culture model of pleura derived from human specimens. After infection of our model with S. aureus, samples were harvested at defined time points. Histological analysis and immunostaining for tight junction proteins (c-Jun, VE-cadherin, and ZO-1) were performed, demonstrating changes comparable to in vivo empyema. The measurement of secreted cytokine levels (TNF-α, MCP-1, and IL-1β) proved host-pathogen interactions in our model. Similarly, mesothelial cells produced VEGF on in vivo levels. These findings were contrasted by vital, unimpaired cells in a sterile control model. We were able to establish a 3D organotypic in vitro co-culture model of human pleura infected with S. aureus resulting in the formation of biofilm, including host-pathogen interactions. This novel model could be a useful microenvironment tool for in vitro studies on biofilm in pleural empyema.}, }
@article {pmid37237397, year = {2023}, author = {Zhang, Q and Peng, L and Han, W and Chen, H and Tang, H and Chen, X and Langford, PR and Huang, Q and Zhou, R and Li, L}, title = {The morphology and metabolic changes of Actinobacillus pleuropneumoniae during its growth as a biofilm.}, journal = {Veterinary research}, volume = {54}, number = {1}, pages = {42}, pmid = {37237397}, issn = {1297-9716}, support = {BB/S019901/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, abstract = {Actinobacillus pleuropneumoniae is an important swine respiratory pathogen. Previous studies have suggested that growth as a biofilm is a natural state of A. pleuropneumoniae infection. To understand the survival features involved in the biofilm state, the growth features, morphology and gene expression profiles of planktonic and biofilm A. pleuropneumoniae were compared. A. pleuropneumoniae in biofilms showed reduced viability but maintained the presence of extracellular polymeric substances (EPS) after late log-phase. Under the microscope, bacteria in biofilms formed dense aggregated structures that were connected by abundant EPS, with reduced condensed chromatin. By construction of Δpga and ΔdspB mutants, polymeric β-1,6-linked N-acetylglucosamine and dispersin B were confirmed to be critical for normal biofilm formation. RNA-seq analysis indicated that, compared to their planktonic counterparts, A. pleuropneumoniae in biofilms had an extensively altered transcriptome. Carbohydrate metabolism, energy metabolism and translation were significantly repressed, while fermentation and genes contributing to EPS synthesis and translocation were up-regulated. The regulators Fnr (HlyX) and Fis were found to be up-regulated and their binding motifs were identified in the majority of the differentially expressed genes, suggesting their coordinated global role in regulating biofilm metabolism. By comparing the transcriptome of wild-type biofilm and Δpga, the utilization of oligosaccharides, iron and sulfur and fermentation were found to be important in adhesion and aggregation during biofilm formation. Additionally, when used as inocula, biofilm bacteria showed reduced virulence in mouse, compared with planktonic grown cells. Thus, these results have identified new facets of A. pleuropneumoniae biofilm maintenance and regulation.}, }
@article {pmid37236447, year = {2023}, author = {Elad, T and Hally, MP and Domingo-Félez, C and Knoop, O and Drewes, JE and Valverde-Pérez, B and Smets, BF}, title = {Exploring the effects of intermittent aeration on the performance of nitrifying membrane-aerated biofilm reactors.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {164329}, doi = {10.1016/j.scitotenv.2023.164329}, pmid = {37236447}, issn = {1879-1026}, abstract = {Membrane-aerated biofilm reactors (MABRs) are an emerging technology for nutrient removal; however, a trade-off remains between their removal rate and oxygen transfer efficiency. This study compares nitrifying flow-through MABRs operated under continuous and intermittent aeration modes at mainstream wastewater ammonia levels. The intermittently-aerated MABRs maintained maximal nitrification rates, including under conditions allowing the oxygen partial pressure on the gas side of the membrane to considerably drop during the no-aeration period. Nitrous oxide emissions of all reactors were comparable and amounted to approximately 20 % of the converted ammonia. Intermittent aeration increased the transformation rate constant of atenolol, yet did not affect the removal of sulfamethoxazole. Seven additional trace organic chemicals were not biodegraded by any of the reactors. The ammonia-oxidizing bacteria in the intermittently-aerated MABRs were dominated by Nitrosospira, previously shown to be abundant at low oxygen concentrations and provide reactor stability under changing conditions. Our findings indicate that intermittently-aerated flow-through MABRs can achieve high nitrification rates and oxygen transfer efficiencies, highlighting the possible implications of air supply discontinuity on nitrous oxide emissions and trace organic chemical biotransformation.}, }
@article {pmid37236444, year = {2023}, author = {Guo, L and Ye, C and Yu, X and Horn, H}, title = {Induction of bacteria in biofilm into a VBNC state by chlorine and monitoring of biofilm structure changes by means of OCT.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {164294}, doi = {10.1016/j.scitotenv.2023.164294}, pmid = {37236444}, issn = {1879-1026}, abstract = {The occurrence of viable but non-culturable (VBNC) bacteria in drinking water may result in significant underestimation of viable cell counts detected by culture-based method, thus raising microbiological safety concern. Chlorine disinfection has been widely used in drinking water treatment to ensure microbiological safety. However, the effect of residual chlorine on inducing bacteria in biofilms into a VBNC state remains unclear. We determined cell numbers of Pseudomonas fluorescence in different physiological states (culturable, viable, dead) by heterotrophic plate count method and flow cytometer in a flow cell system under 0, 0.1, 0.5, 1.0 mg/L chlorine treatment. Numbers of culturable cells were 4.66 ± 0.47 Log10, 2.82 ± 0.76 Log10, 2.30 ± 1.23 Log10 (CFU/112.5 mm[3]) in each chlorine treatment group. However, viable cell numbers remained at 6.32 ± 0.05 Log10, 6.11 ± 0.24 Log10, 5.08 ± 0.81 Log10 (cells/112.5 mm[3]). Significant difference between numbers of viable and culturable cells demonstrated chlorine could induce bacteria in biofilms into a VBNC state. In this study, flow cells combination with Optical Coherence Tomography (OCT) were applied to construct an Automated experimental Platform for replicate Biofilm cultivation and structural Monitoring (APBM) system. The OCT imaging results demonstrated that changes of biofilm structure under chlorine treatment were closely related to their inherent characteristics. Biofilms with low thickness and high roughness coefficient or porosity were easier to be removed from the substrate. Biofilm with high rigid properties were more resistant to chlorine treatment. Even though >95 % bacteria in biofilms entered a VBNC state, the biofilm physical structure was still remained. This study revealed the possibility of bacteria to enter a VBNC state in drinking water biofilms and changes of biofilm structure with different characteristics under chlorine treatment, which provide reference for biofilms control in drinking water distribution system.}, }
@article {pmid37235946, year = {2023}, author = {Xu, Y and Liu, S and Zhao, H and Li, Y and Cui, C and Chou, W and Zhao, Y and Yang, J and Qiu, H and Zeng, J and Chen, D and Wu, S and Tan, Y and Wang, Y and Gu, Y}, title = {Ultrasonic irradiation enhanced the efficacy of antimicrobial photodynamic therapy against methicillin-resistant Staphylococcus aureus biofilm.}, journal = {Ultrasonics sonochemistry}, volume = {97}, number = {}, pages = {106423}, doi = {10.1016/j.ultsonch.2023.106423}, pmid = {37235946}, issn = {1873-2828}, abstract = {Antimicrobial photodynamic therapy (aPDT) is a non-pharmacological antimicrobial regimen based on light, photosensitizer and oxygen. It has become a potential method to inactivate multidrug-resistant bacteria. However, limited by the delivery of photosensitizer (PS) in biofilm, eradicating biofilm-associated infections by aPDT remains challenging. This study aimed to explore the feasibility of combining ultrasonic irradiation with aPDT to enhance the efficacy of aPDT against methicillin-resistant staphylococcus aureus (MRSA) biofilm. A cationic benzylidene cyclopentanone photosensitizer with much higher selectivity to bacterial cells than mammalian cells were applied at the concentration of 10 μM. 532 nm laser (40 mW/cm[2], 10 min) and 1 MHz ultrasound (500 mW/cm[2], 10 min, simultaneously with aPDT) were employed against MRSA biofilms in vitro. In addition to combined with ultrasonic irradiation and aPDT, MRSA biofilms were treated with laser irradiation only, photosensitizer only, ultrasonic irradiation only, ultrasonic irradiation and photosensitizer, and aPDT respectively. The antibacterial efficacy was determined by XTT assay, and the penetration depth of PS in biofilm was observed using a photoluminescence spectrometer and a confocal laser scanning microscopy (CLSM). In addition, the viability of human dermal fibroblasts (WS-1 cells) after the same treatments mentioned above and the uptake of P3 by WS-1 cells after ultrasonic irradiation were detected by CCK-8 and CLSM in vitro. Results showed that the percent decrease in metabolic activity resulting from the US + aPDT group (75.76%) was higher than the sum of the aPDT group (44.14%) and the US group (9.88%), suggesting synergistic effects. Meanwhile, the diffusion of PS in the biofilm of MRSA was significantly increased by 1 MHz ultrasonic irradiation. Ultrasonic irradiation neither induced the PS uptake by WS-1 cells nor reduced the viability of WS-1 cells. These results suggested that 1 MHz ultrasonic irradiation significantly enhanced the efficacy of aPDT against MRSA biofilm by increasing the penetration depth of PS. In addition, the antibacterial efficacy of aPDT can be enhanced by ultrasonic irradiation, the US + aPDT treatment demonstrated encouraging in vivo antibacterial efficacy (1.73 log10 CFU/mL reduction). In conclusion, the combination of aPDT and 1 MHz ultrasound is a potential and promising strategy to eradicate biofilm-associated infections of MRSA.}, }
@article {pmid37235500, year = {2023}, author = {Shi, X and Lin, L and Sun, J}, title = {The Value of Continuous Closed Negative Pressure Drainage Combined with Antibacterial Biofilm Dressing in Postoperative Wound Healing for Severe Pancreatitis.}, journal = {Alternative therapies in health and medicine}, volume = {}, number = {}, pages = {}, pmid = {37235500}, issn = {1078-6791}, abstract = {OBJECTIVE: To investigate the application value of continuous vacuum sealing drainage (VSD) combined with antibacterial biofilm hydraulic fiber dressing in wound healing after surgery for severe acute pancreatitis (SAP).<br><br>METHODS: A total of 82 SAP patients who underwent minimally invasive surgery in our hospital from March 2021 to September 2022 were randomly divided into two groups using a random number table method. Each group consisted of 41 cases. Both groups received surgical treatment, with the control group receiving VSD treatment and the observation group receiving VSD treatment combined with antibacterial biofilm hydraulic fiber dressing. The postoperative recovery efficiency, preoperative and postoperative wound area reduction rate, pressure ulcer healing score (PUSH), serum biological indicators (white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT)), and the rate of wound-related adverse reactions were compared between the two groups.<br><br>RESULTS: There was no statistical difference between the two groups in the time to resume eating (P > .05). However, the wound healing time and hospitalization days in the observation group were significantly shorter than those in the control group (P < .05). After 7 and 14 days of treatment, the wound area reduction rate in the observation group was significantly higher than in the control group, and the PUSH score was significantly lower than in the control group (P < .05). WBC, CRP, and PCT levels in the observation group were lower than in the control group (P < .05). The incidence of wound-related adverse reactions in the observation group (12.20%) was significantly lower than that in the control group (34.15%) (P < .05).<br><br>CONCLUSIONS: The application of VSD combined with antibacterial biofilm hydraulic fiber dressing in the postoperative wound healing of SAP has a significant effect. It improves wound healing efficiency, reduces pressure ulcer scores, decreases inflammation indicators, and lowers the incidence of adverse reactions. While further research is needed to determine its impact on infection and inflammation prevention, this treatment approach shows promise for clinical application.}, }
@article {pmid37235397, year = {2023}, author = {Katsburg, M and Weingart, C and Aubry, E and Kershaw, O and Kikhney, J and Kursawe, L and Lübke-Becker, A and Moter, A and Skrodzki, M and Kohn, B and Fulde, M}, title = {Limiting Factors in Treatment Success of Biofilm-Forming Streptococci in the Case of Canine Infective Endocarditis Caused by Streptococcus canis.}, journal = {Veterinary sciences}, volume = {10}, number = {5}, pages = {}, doi = {10.3390/vetsci10050314}, pmid = {37235397}, issn = {2306-7381}, abstract = {An 8-year-old male Rhodesian Ridgeback was presented with fever and severe thrombocytopenia. Clinical and laboratory examination, echocardiography, blood culture, and pathohistology revealed evidence of infective endocarditis, ischemic renal infarcts, and septic encephalitis. Treatment was started immediately but the dog's condition worsened, and the dog had to be euthanized. The causative Streptococcus canis strain was detected by blood culture and MALDI-TOF MS and analyzed using whole-genome sequencing and multilocus sequence typing. Antibiotic susceptibility testing did not detect any resistance. The affected heart valve was analyzed using FISH imaging, which showed a streptococcal biofilm on the heart valve. Bacteria in biofilms are recalcitrant to antibiotic treatment. Early diagnosis could be beneficial to treatment outcome. Treatment of endocarditis could be improved by researching the optimal dosage of antibiotics in conjunction with the use of biofilm-active drugs.}, }
@article {pmid37234778, year = {2023}, author = {Ren, Q and Luo, W and Chi, H and Zhang, L and Chen, W}, title = {Down-regulation of β-lactam antibiotics resistance and biofilm formation by Staphylococcus epidermidis is associated with isookanin.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1139796}, pmid = {37234778}, issn = {2235-2988}, abstract = {INTRODUCTION: Biofilm formation is the major pathogenicity of Staphylococcus epidermidis (S. epidermidis), which enhances bacterial resistance to antibiotics. Isookanin has potential inhibitory activity on biofilm.<br><br>METHOD: The inhibiting mechanisms of isookanin against biofilm formation through surface hydrophobicity assay, exopolysaccharides, eDNA, gene expression analysis, microscopic visualization, and molecular docking were explored. Additionally, the combination of isookanin and &#x3b2;-lactam antibiotics were evaluated by the broth micro-checkerboard assay.<br><br>RESULTS: The results showed that isookanin could decrease the biofilm formation of S. epidermidis by &#x2265;85% at 250 &#x3bc;g/mL. The exopolysaccharides, eDNA and surface hydrophobicity were reduced after treatment with isookanin. Microscopic visualization analysis showed that there were fewer bacteria on the surface of the microscopic coverslip and the bacterial cell membrane was damaged after treatment with isookanin. The down-regulation of icaB and up-regulation of icaR were observed after treatment with isookanin. Additionally, the RNAIII gene was significantly up-regulated (p < 0.0001) at the mRNA level. Molecular docking showed that isookanin could bind to biofilm-related proteins. This indicated that isookanin can affect biofilm formation at the initial attachment phase and the aggregation phase. The FICI index showed that the combination of isookanin and &#x3b2;-lactam antibiotics were synergistic and could reduce doses of antibiotics by inhibiting biofilm formation.<br><br>DISCUSSION: This study improved the antibiotic susceptibility of S. epidermidis through inhibition of the biofilm formation, and provided a guidance for the treatment of antibiotic resistance caused by biofilm.}, }
@article {pmid37234777, year = {2023}, author = {Alamiri, F and André, O and De, S and Nordenfelt, P and Hakansson, AP}, title = {Role of serotype and virulence determinants of Streptococcus pyogenes biofilm bacteria in internalization and persistence in epithelial cells in vitro.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1146431}, pmid = {37234777}, issn = {2235-2988}, abstract = {Streptococcus pyogenes causes a multitude of local and systemic infections, the most common being pharyngitis in children. Recurrent pharyngeal infections are common and are thought to be due to the re-emergence of intracellular GAS upon completion of antibiotic treatment. The role of colonizing biofilm bacteria in this process is not fully clear. Here, live respiratory epithelial cells were inoculated with broth-grown or biofilm bacteria of different M-types, as well as with isogenic mutants lacking common virulence factors. All M-types tested adhered to and were internalized into epithelial cells. Interestingly, internalization and persistence of planktonic bacteria varied significantly between strains, whereas biofilm bacteria were internalized in similar and higher numbers, and all strains persisted beyond 44 hours, showing a more homogenous phenotype. The M3 protein, but not the M1 or M5 proteins, was required for optimal uptake and persistence of both planktonic and biofilm bacteria inside cells. Moreover, the high expression of capsule and SLO inhibited cellular uptake and capsule expression was required for intracellular survival. Streptolysin S was required for optimal uptake and persistence of M3 planktonic bacteria, whereas SpeB improved intracellular survival of biofilm bacteria. Microscopy of internalized bacteria showed that planktonic bacteria were internalized in lower numbers as individual or small clumps of bacteria in the cytoplasm, whereas GAS biofilm bacteria displayed a pattern of perinuclear localization of bacterial aggregates that affected actin structure. Using inhibitors targeting cellular uptake pathways, we confirmed that planktonic GAS mainly uses a clathrin-mediated uptake pathway that also required actin and dynamin. Clathrin was not involved in biofilm internalization, but internalization required actin rearrangement and PI3 kinase activity, possibly suggesting macropinocytosis. Together these results provide a better understanding of the potential mechanisms of uptake and survival of various phenotypes of GAS bacteria relevant for colonization and recurrent infection.}, }
@article {pmid37234036, year = {2023}, author = {Chen, Y and Gao, Y and Huang, Y and Jin, Q and Ji, J}, title = {Inhibiting Quorum Sensing by Active Targeted pH-Sensitive Nanoparticles for Enhanced Antibiotic Therapy of Biofilm-Associated Bacterial Infections.}, journal = {ACS nano}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsnano.2c12151}, pmid = {37234036}, issn = {1936-086X}, abstract = {Inhibition of quorum sensing (QS) is considered as an effective strategy in combatting biofilm-associated bacterial infections. However, the application of quorum sensing inhibitors (QSI) is strongly restricted by poor water-solubility and low bioavailability. We herein fabricate pH-sensitive curcumin (Cur) loaded clustered nanoparticles with active targeting ability (denoted as anti-CD54@Cur-DA NPs) to inhibit QS for enhanced antibiotic therapy. Cur-DA NPs are first prepared through electrostatic interaction between Cur loaded amino-ended poly(amidoamine) dendrimer (PAMAM) and 2,3-dimethyl maleic anhydride (DA) modified biotin-poly(ethylene glycol)-polylysine (biotin-PEG-PLys). Anti-CD54@Cur-DA NPs are then obtained by the modification of Cur-DA NPs with anti-CD54. Cur loaded PAMAM can be released from Cur-DA NPs in acidic pH, leading to simultaneous charge reversal and size decrease, which is beneficial for biofilm penetration. Cur-DA NPs are hence much better in inhibiting QS than free Cur due to enhanced biofilm penetration. Compared to free Cur, Cur-DA NPs exhibit stronger capability in inhibiting the development of biofilm architecture and maturation, thus downregulating efflux pump-related genes and improving bactericidal performance of multiple antibiotics, including Penicillin G, ciprofloxacin, and tobramycin. Moreover, since anti-CD54 can selectively bind to inflamed endothelial cells, anti-CD54@Cur-DA NPs can be targeted accumulated in bacteria-infected tissues. The sequential treatment using anti-CD54@Cur-DA NPs and free antibiotics can effectively reduce bacterial burden and alleviate inflammation in a chronic lung infection model in vivo. This research provides an effective way to improve the therapeutic performance of QSI to enhance the anti-biofilm effects of antibiotics, which radiate a vitality of conventional antibiotics in treating biofilm-associated bacterial infections.}, }
@article {pmid37233292, year = {2023}, author = {Salvador, A and Veiga, FF and Svidzinski, TIE and Negri, M}, title = {Case of Mixed Infection of Toenail Caused by Candida parapsilosis and Exophiala dermatitidis and In Vitro Effectiveness of Propolis Extract on Mixed Biofilm.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {5}, pages = {}, pmid = {37233292}, issn = {2309-608X}, abstract = {Onychomycosis is a chronic fungal nail infection caused by several filamentous and yeast-like fungi, such as the genus Candida spp., of great clinical importance. Black yeasts, such as Exophiala dermatitidis, a closely related Candida spp. species, also act as opportunistic pathogens. Fungi infectious diseases are affected by organisms organized in biofilm in onychomycosis, making treatment even more difficult. This study aimed to evaluate the in vitro susceptibility profile to propolis extract and the ability to form a simple and mixed biofilm of two yeasts isolated from the same onychomycosis infection. The yeasts isolated from a patient with onychomycosis were identified as Candida parapsilosis sensu stricto and Exophiala dermatitidis. Both yeasts were able to form simple and mixed (in combination) biofilms. Notably, C. parapsilosis prevailed when presented in combination. The susceptibility profile of propolis extract showed action against E. dermatitidis and C. parapsilosis in planktonic form, but when the yeasts were in mixed biofilm, we only observed action against E. dermatitidis, until total eradication.}, }
@article {pmid37233237, year = {2023}, author = {Zheng, L and Gu, X and Sun, L and Dong, M and Gao, A and Han, Z and Pan, H and Zhang, H}, title = {Adding Metal Ions to the Bacillus mojavensis D50 Promotes Biofilm Formation and Improves Ability of Biocontrol.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {5}, pages = {}, pmid = {37233237}, issn = {2309-608X}, abstract = {Bacillus mojavensis D50, a biocontrol strain, is used to prevent and treat the fungal plant pathogen Botrytis cinerea. Bacillus mojavensis D50's biofilms can affect its colonization; thus, the effects of different metal ions and culture conditions on biofilm formation were determined in this study. The results of medium optimization showed that Ca[2+] had the best ability to promote biofilm formation. The optimal medium composition for the formation of biofilms contained tryptone (10 g/L), CaCl2 (5.14 g/L), and yeast extract (5.0 g/L), and the optimal fermentation conditions included pH 7, a temperature of 31.4 °C, and a culture time of 51.8 h. We found that the antifungal activity and abilities to form biofilms and colonize roots were improved after optimization. In addition, the levels of expression of the genes luxS, SinR, FlhA, and tasA were up-regulated by 37.56-, 2.87-, 12.46-, and 6.22-fold, respectively. The soil enzymatic activities which related biocontrol-related enzymes were the highest when the soil was treated by strain D50 after optimization. In vivo biocontrol assays indicated that the biocontrol effect of strain D50 after optimization was improved.}, }
@article {pmid37231227, year = {2023}, author = {Bajire, SK and Prabhu, A and Bhandary, YP and Irfan, KM and Shastry, RP}, title = {7-Ethoxycoumarin rescued Caenorhabditis elegans from infection of COPD derived clinical isolate Pseudomonas aeruginosa through virulence and biofilm inhibition via targeting Rhl and Pqs quorum sensing systems.}, journal = {World journal of microbiology &amp; biotechnology}, volume = {39}, number = {8}, pages = {208}, pmid = {37231227}, issn = {1573-0972}, abstract = {Pseudomonas aeruginosa is an ambidextrous Gram-negative contagium with density convoluted network defined quorum sensing, which enables the persistent survival within the host environment, contributing to various lung related diseases including Chronic Obstructive Pulmonary Disease (COPD). It is clear that P. aeruginosa is a powerful, exquisite pathogen that has adopted a variety of virulence properties through quorum sensing (QS) regulated phenomenon and that it dominates both in the development and exacerbations of COPD. Interestingly, 7-Ethoxycoumarin (7-EC), a compound that adequately mimics QS signaling molecule of P. aeruginosa, was introduced as part of the process of developing novel ways to treat the severe exacerbations. The results showed that, introduction of 7-EC significantly decreased exopolysaccharide-mediated biofilm development of strains isolated from COPD sputum, as evidenced by SEM analysis. Furthermore, 7-EC was able to modulate a variety of virulence factors and motility without subjecting planktonic cells to any selection pressure. Bacterial invasion assay revealed the potential activity of the 7-EC in preventing the active entry to A549 cells without causing any damage to the cells and found functionally active in protecting the C. elegans from P. aeruginosa infection and being non-toxic to the worms. Docking analysis was further proved that 7-EC to be the potential anti-QS compound competing specifically with Rhl and Pqs Systems. Therefore, 7-EC in the utilisation against the P. aeruginosa based infections, may open an avenue for the futuristic mechanistic study in chronic respiratory diseases and a initiator for the development of non-antibiotic based antibacterial therapy.}, }
@article {pmid37230332, year = {2023}, author = {Siriweera, B and Ahmar Siddiqui, M and Zou, X and Chen, G and Wu, D}, title = {Integrated thiosulfate-driven denitrification, partial nitrification and anammox process in membrane-aerated biofilm reactor for low-carbon, energy-efficient biological nitrogen removal.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {129212}, doi = {10.1016/j.biortech.2023.129212}, pmid = {37230332}, issn = {1873-2976}, abstract = {Combining multiple bioprocesses in a single membrane-aerated biofilm reactor (MABR) unit for wastewater treatment is an emerging research focus. This study investigated the feasibility of coupling thiosulfate-driven denitrification (TDD) with partial nitrification and anammox (PNA) in a MABR for the treatment of ammonium-containing wastewater. The integrated bioprocess was tested over a continuous operation period (>130 d) in two MABRs: one with a polyvinylidene fluoride membrane (MABR-1), and the other with micro-porous aeration tubes covered with non-wovenpolyester fabrics (MABR-2). After start-up, the MABR-1 and MABR-2 based on the TDD-PNA process achieved satisfactory total nitrogen removal efficiencies of 63% and 76%, with maximum oxygen utilisation efficiencies of up to 66% and 80% and nitrogen removal fluxes of 1.3 and 4.7 gN/(m[2]·d), respectively. Predictions from the AQUASIM-model verified the integrated bioprocess. These lab scale findings confirmed the applicability of MABR technology for simultaneous sulfur and nitrogen removal, promising for pilot-scale application.}, }
@article {pmid37229517, year = {2023}, author = {Mello, TP and Barcellos, IC and Branquinha, MH and Santos, ALS}, title = {Cell dispersion during biofilm formation by Scedosporium apiospermum, Scedosporium aurantiacum, Scedosporium minutisporum and Lomentospora prolificans.}, journal = {Current research in microbial sciences}, volume = {4}, number = {}, pages = {100191}, pmid = {37229517}, issn = {2666-5174}, abstract = {Dispersion is an essential step in the lifecycle of biofilms, since it enables the dissemination of microbial cells and, consequently, the potential colonization of new sites. Filamentous fungi belonging to the Scedosporium/Lomentospora genera are opportunistic human pathogens able to form multidrug-resistant biofilms on surfaces of different chemical compositions, environments and nutritional conditions. Despite the rising understanding of how biofilms are formed by Scedosporium/Lomentospora species, the cell dispersal step has not yet been explored. In the present study, the cell dispersion was investigated during biofilm formation by S. apiospermum, S. minutisporum, S. aurantiacum and L. prolificans cells. The results revealed that conidia were the major type of dispersed cells, which were detected throughout biofilm development (from 24 to 72 h). Dispersion was not influenced by increased glucose concentration (the main source for energetic metabolism) neither the presence of voriconazole (the most common antifungal used to treat scedosporiosis); however, the presence of mucin (a component of mucous, present in the lungs of cystic fibrosis patients, who are usually affected by these filamentous fungi) triggered cell dispersion. Contrarily, a poor nutritional environment (e.g., phosphate-buffered saline) inhibited this step. Overall, our study reveals new insights into the biofilm development of Scedosporium/Lomentospora species.}, }
@article {pmid37228667, year = {2023}, author = {Theis, TJ and Daubert, TA and Kluthe, KE and Brodd, KL and Nuxoll, AS}, title = {Staphylococcus aureus persisters are associated with reduced clearance in a catheter-associated biofilm infection.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1178526}, pmid = {37228667}, issn = {2235-2988}, abstract = {BACKGROUND: Staphylococcus aureus causes a wide variety of infections, many of which are chronic or relapsing in nature. Antibiotic therapy is often ineffective against S. aureus biofilm-mediated infections. Biofilms are difficult to treat partly due to their tolerance to antibiotics, however the underlying mechanism responsible for this remains unknown. One possible explanation is the presence of persister cells-dormant-like cells that exhibit tolerance to antibiotics. Recent studies have shown a connection between a fumC (fumarase C, a gene in the tricarboxylic acid cycle) knockout strain and increased survival to antibiotics, antimicrobial peptides, and in a Drosophila melanogaster model.<br><br>OBJECTIVE: It remained unclear whether a S. aureus high persister strain would have a survival advantage in the presence of innate and adaptive immunity. To further investigate this, a fumC knockout and wild type strains were examined in a murine catheter-associated biofilm model.<br><br>RESULTS: Interestingly, mice struggled to clear both S. aureus wild type and the fumC knockout strains. We reasoned both biofilm-mediated infections predominantly consisted of persister cells. To determine the persister cell population within biofilms, expression of a persister cell marker (Pcap5A::dsRED) in a biofilm was examined. Cell sorting of biofilms challenged with antibiotics revealed cells with intermediate and high expression of cap5A had 5.9-and 4.5-fold higher percent survival compared to cells with low cap5A expression. Based on previous findings that persisters are associated with reduced membrane potential, flow cytometry analysis was used to examine the metabolic state of cells within a biofilm. We confirmed cells within biofilms had reduced membrane potential compared to both stationary phase cultures (2.5-fold) and exponential phase cultures (22.4-fold). Supporting these findings, cells within a biofilm still exhibited tolerance to antibiotic challenge following dispersal of the matrix through proteinase K.<br><br>CONCLUSION: Collectively, these data show that biofilms are largely comprised of persister cells, and this may explain why biofilm infections are often chronic and/or relapsing in clinical settings.}, }
@article {pmid37228184, year = {2023}, author = {Kandoth, N and Chaudhary, SP and Gupta, S and Raksha, K and Chatterjee, A and Gupta, S and Karuthedath, S and De Castro, CSP and Laquai, F and Pramanik, SK and Bhattacharyya, S and Mallick, AI and Das, A}, title = {Multimodal Biofilm Inactivation Using a Photocatalytic Bismuth Perovskite-TiO2-Ru(II)polypyridyl-Based Multisite Heterojunction.}, journal = {ACS nano}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsnano.3c01064}, pmid = {37228184}, issn = {1936-086X}, abstract = {Infectious bacterial biofilms are recalcitrant to most antibiotics compared to their planktonic version, and the lack of appropriate therapeutic strategies for mitigating them poses a serious threat to clinical treatment. A ternary heterojunction material derived from a Bi-based perovskite-TiO2 hybrid and a [Ru(2,2'-bpy)2(4,4'-dicarboxy-2,2'-bpy)][2+] (2,2'-bpy, 2,2'-bipyridyl) as a photosensitizer (RuPS) is developed. This hybrid material is found to be capable of generating reactive oxygen species (ROS)/reactive nitrogen species (RNS) upon solar light irradiation. The aligned band edges and effective exciton dynamics between multisite heterojunctions are established by steady-state/time-resolved optical and other spectroscopic studies. Proposed mechanistic pathways for the photocatalytic generation of ROS/RNS are rationalized based on a cascade-redox processes arising from three catalytic centers. These ROS/RNS are utilized to demonstrate a proof-of-concept in treating two elusive bacterial biofilms while maintaining a high level of biocompatibility (IC50 > 1 mg/mL). The in situ generation of radical species (ROS/RNS) upon photoirradiation is established with EPR spectroscopic measurements and colorimetric assays. Experimental results showed improved efficacy toward biofilm inactivation of the ternary heterojunction material as compared to their individual/binary counterparts under solar light irradiation. The multisite heterojunction formation helped with better exciton delocalization for an efficient catalytic biofilm inactivation. This was rationalized based on the favorable exciton dissociation followed by the onset of multiple oxidation and reduction sites in the ternary heterojunction. This together with exceptional photoelectric features of lead-free halide perovskites outlines a proof-of-principle demonstration in biomedical optoelectronics addressing multimodal antibiofilm/antimicrobial modality.}, }
@article {pmid37227545, year = {2023}, author = {Kuwada, N and Fujii, Y and Nakatani, T and Ousaka, D and Tsuji, T and Imai, Y and Kobayashi, Y and Oozawa, S and Kasahara, S and Tanemoto, K}, title = {Diamond-like carbon coating to inner surface of polyurethane tube reduces Staphylococcus aureus bacterial adhesion and biofilm formation.}, journal = {Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs}, volume = {}, number = {}, pages = {}, pmid = {37227545}, issn = {1619-0904}, abstract = {Staphylococcus aureus is one of the main causative bacteria for polyurethane catheter and artificial graft infection. Recently, we developed a unique technique for coating diamond-like carbon (DLC) inside the luminal resin structure of polyurethane tubes. This study aimed to elucidate the infection-preventing effects of diamond-like carbon (DLC) coating on a polyurethane surface against S. aureus. We applied DLC to polyurethane tubes and rolled polyurethane sheets with our newly developed DLC coating technique for resin tubes. The DLC-coated and uncoated polyurethane surfaces were tested in smoothness, hydrophilicity, zeta-potential, and anti-bacterial properties against S. aureus (biofilm formation and bacterial attachment) by contact with bacterial fluids under static and flow conditions. The DLC-coated polyurethane surface was significantly smoother, more hydrophilic, and had a more negative zeta-potential than did the uncoated polyurethane surface. Upon exposure to bacterial fluid under both static and flow conditions, DLC-coated polyurethane exhibited significantly less biofilm formation than uncoated polyurethane, based on absorbance measurements. In addition, the adherence of S. aureus was significantly lower for DLC-coated polyurethane than for uncoated polyurethane under both conditions, based on scanning electron microscopy. These results show that applying DLC coating to the luminal resin of polyurethane tubes may impart antimicrobial effects against S. aureus to implantable medical polyurethane devices, such as vascular grafts and central venous catheters.}, }
@article {pmid37226152, year = {2023}, author = {Bakó, C and Balázs, VL and Kerekes, E and Kocsis, B and Nagy, DU and Szabó, P and Micalizzi, G and Mondello, L and Krisch, J and Pethő, D and Horváth, G}, title = {Flowering phenophases influence the antibacterial and anti-biofilm effects of Thymus vulgaris L. essential oil.}, journal = {BMC complementary medicine and therapies}, volume = {23}, number = {1}, pages = {168}, pmid = {37226152}, issn = {2662-7671}, mesh = {*Oils, Volatile/pharmacology ; *Thymus Plant ; Gas Chromatography-Mass Spectrometry ; Anti-Bacterial Agents/pharmacology ; }, abstract = {BACKGROUND: Essential oils are becoming increasingly popular in medicinal applications because of their antimicrobial effect. Thymus vulgaris L. (Lamiaceae) is a well-known and widely cultivated medicinal plant, which is used as a remedy for cold, cough and gastrointestinal symptoms. Essential oil content of thyme is responsible for its antimicrobial activity, however, it has been reported that the chemical composition of essential oils influences its biological activity. In order to explore flowering phenophases influence on the chemical composition of thyme essential oil and its antibacterial and anti-biofilm activity, plant materials were collected at the beginning of flowering, in full bloom and at the end of flowering periods in 2019.<br><br>METHODS: Essential oils from fresh and dried plant materials were distilled and analyzed with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). The antibacterial activity was performed by broth microdilution and thin layer chromatography-direct bioautography (TLC-DB) assays and the anti-biofilm effect by crystal violet assay, respectively. Scanning electron microscopy was applied to illustrate the cellular changes of bacterial cells after essential oil treatment.<br><br>RESULTS: Thymol (52.33-62.46%) was the main component in the thyme essential oils. Thyme oil distilled from fresh plant material and collected at the beginning of flowering period exerted the highest antibacterial and anti-biofilm activity against Haemophilus influenzae, H. parainfluenzae and Pseudomonas aeruginosa.<br><br>CONCLUSION: The different flowering periods of Thymus vulgaris influence the antibacterial and anti-biofilm activity of its essential oils, therefore, the collection time has to be taken into consideration and not only the full bloom, but the beginning of flowering period may provide biological active thyme essential oil.}, }
@article {pmid37224996, year = {2023}, author = {Karine Marcomini, E and Negri, M}, title = {Fungal quorum-sensing molecules and antiseptics: a promising strategy for biofilm modulation?.}, journal = {Drug discovery today}, volume = {}, number = {}, pages = {103624}, doi = {10.1016/j.drudis.2023.103624}, pmid = {37224996}, issn = {1878-5832}, abstract = {New strategies to control fungal biofilms are essential, especially those that interfere in the biofilm organization process and cellular communication, known as quorum sensing. The effect of antiseptics and quorum-sensing molecules (QSMs) have been considered with regard to this; however, little has been elucidated, particularly because studies are often restricted to the action of antiseptics and QSMs against a few fungal genera. In this review, we discuss progress reported in the literature thus far and analyze, through in silico methods, 13 fungal QSMs with regard to their physicochemical, pharmacological, and toxicity properties, including their mutagenicity, tumorigenicity, hepatotoxicity, and nephrotoxicity. From these in silico analyses, we highlight 4-hydroxyphenylacetic acid and tryptophol as having satisfactory properties and, thus, propose that these should be investigated further as antifungal agents. We also recommend future in vitro approaches to determine the association of QSMs with commonly used antiseptics as potential antibiofilm agents.}, }
@article {pmid37224983, year = {2023}, author = {Gao, L and Tang, Z and Li, T and Wang, J}, title = {Myricetin exerts anti-biofilm activity and attenuates osteomyelitis by inhibiting the TLR2/MAPK pathway in experimental mice.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106165}, doi = {10.1016/j.micpath.2023.106165}, pmid = {37224983}, issn = {1096-1208}, abstract = {AIMS: To evaluate the potential of Myricetin against S.aureus induced osteomyelitis.<br><br>BACKGROUND: Osteomyelitis is infected condition of bone by micro-organisms. The mitogen-activated protein kinase (MAPK), inflammatory cytokines and Toll-like receptor-2 (TLR-2) pathway are mainly involved in osteomyelitis. Myricetin is a plant-food derived flavonoid which shows anti-inflammatory activity.<br><br>OBJECTIVE: In the present study, we evaluated the potential of Myricetin against S.aureus induced osteomyelitis. MC3T3-E1 cells were used for in vitro studies.<br><br>METHOD: Murine model of osteomyelitis was developed in BALB/c mice by injecting S.aureus in the medullary cavity of the femur. The mice were studied for bone destruction, anti-biofilm activity, osteoblast growth markers alkaline phosphatase (ALP), osteopontin (OCN) and collagen type-I (COLL-1) were studied by RT-PCR, ELISA analysis for levels of proinflammatory factors CRP, IL-6 and IL-1&#x3b2;. Expression of proteins by Western blot analysis and anti-biofilm effect by Sytox green dye fluorescence assay. Target confirmation was done by performing in silico docking analysis.<br><br>RESULTS: Myricetin reduced bone destruction in osteomyelitis induced mice. The treatment decreased bone levels of ALP, OCN, COLL-1 and TLR2. Myricetin decreased serum levels of CRP, IL-6 and IL-1&#x3b2;. The treatment suppressed activation of MAPK pathway and showed anti-biofilm effect. Docking studies suggested high binding affinity of Myricetin with MAPK protein in silico, by showing lower binding energies.<br><br>CONCLUSION: Myricetin suppresses osteomyelitis by inhibiting ALP, OCN, COLL-1 via the TLR2 and MAPK pathway involving inhibition of biofilm formation. In silico studies suggested MAPK as potential binding protein for myricetin.}, }
@article {pmid37224668, year = {2023}, author = {Kim, B and Madukoma, CS and Shrout, JD and Nerenberg, R}, title = {Effect of EPS production on the performance of membrane-based biofilm reactors.}, journal = {Water research}, volume = {240}, number = {}, pages = {120101}, doi = {10.1016/j.watres.2023.120101}, pmid = {37224668}, issn = {1879-2448}, abstract = {This study explored the effect of extracellular polymeric substance (EPS) production on the performance of membrane-based biofilm reactors. Changing EPS production was induced by eliminating one of the main EPS polysaccharides, i.e., Pel. The studies were carried out using a pure culture of either Pseudomonas aeruginosa or an isogenic P. aeruginosa mutant that was unable to produce the Pel polysaccharide. The biofilm cell density for both strains was compared to confirm the Pel deletion mutant decreased overall EPS production in a bioreactor system. When the Pel-deficient mutant was grown as a biofilm, its cell density, i.e., ratio of cells/(cells + EPS), was 74 % higher than the wild type, showing EPS production was reduced by eliminating pel production. The growth kinetics were determined for both strains. The Pel-deficient mutant had a maximum specific growth rate (μ^) that was 14% higher than the wild type. Next, the effects of EPS reduction on reactor performance were assessed for a membrane aerated biofilm reactor (MABR) and a membrane bioreactor (MBR). For the MABR, the organic removal with the Pel-deficient mutant was around 8% higher than for the wild type. For the MBR, the time to reach the fouling threshold was 65 % greater for the Pel-deficient mutant than for the wild type. These results suggest that amount of EPS production can have significant effects on bacterial growth kinetics and bacterial cell density, which in turn can affect the performance of the membrane-based biofilm reactors. In both cases, lower EPS production correlated with more efficient treatment processes.}, }
@article {pmid37223955, year = {2023}, author = {Jakkampudi, T and Lin, Q and Mitra, S and Vijai, A and Qin, W and Kang, A and Chen, J and Ryan, E and Wang, R and Gong, Y and Heinrich, F and Song, J and Di, YP and Tristram-Nagle, S}, title = {Lung SPLUNC1 Peptide Derivatives in the Lipid Membrane Headgroup Kill Gram-Negative Planktonic and Biofilm Bacteria.}, journal = {Biomacromolecules}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.biomac.3c00218}, pmid = {37223955}, issn = {1526-4602}, abstract = {SPLUNC1 (short palate lung and nasal epithelial clone 1) is a multifunctional host defense protein found in human respiratory tract with antimicrobial properties. In this work, we compare the biological activities of four SPLUNC1 antimicrobial peptide (AMP) derivatives using paired clinical isolates of the Gram-negative (G(-)) bacteria Klebsiella pneumoniae, obtained from 11 patients with/without colistin resistance. Secondary structural studies were carried out to study interactions between the AMPs and lipid model membranes (LMMs) utilizing circular dichroism (CD). Two peptides were further characterized using X-ray diffuse scattering (XDS) and neutron reflectivity (NR). A4-153 displayed superior antibacterial activity in both G(-) planktonic cultures and biofilms. NR and XDS revealed that A4-153 (highest activity) is located primarily in membrane headgroups, while A4-198 (lowest activity) is located in hydrophobic interior. CD revealed that A4-153 is helical, while A4-198 has little helical character, demonstrating that helicity and efficacy are correlated in these SPLUNC1 AMPs.}, }
@article {pmid37222596, year = {2023}, author = {Ma, D and Yu, M and Eszterhas, S and Rollenhagen, C and Lee, SA}, title = {A C. albicans TRAPP Complex-Associated Gene Contributes to Cell Wall Integrity, Hyphal and Biofilm Formation, and Tissue Invasion.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0536122}, doi = {10.1128/spectrum.05361-22}, pmid = {37222596}, issn = {2165-0497}, abstract = {While endocytic and secretory pathways are well-studied cellular processes in the model yeast Saccharomyces cerevisiae, they remain understudied in the opportunistic fungal pathogen Candida albicans. We previously found that null mutants of C. albicans homologs of the S. cerevisiae early endocytosis genes ENT2 and END3 not only exhibited delayed endocytosis but also had defects in cell wall integrity, filamentation, biofilm formation, extracellular protease activity, and tissue invasion in an in vitro model. In this study, we focused on a potential C. albicans homolog to S. cerevisiae TCA17, which was discovered in our whole-genome bioinformatics approach aimed at identifying genes involved in endocytosis. In S. cerevisiae, TCA17 encodes a transport protein particle (TRAPP) complex-associated protein. Using a reverse genetics approach with CRISPR-Cas9-mediated gene deletion, we analyzed the function of the TCA17 homolog in C. albicans. Although the C. albicans tca17Δ/Δ null mutant did not have defects in endocytosis, it displayed an enlarged cell and vacuole morphology, impaired filamentation, and reduced biofilm formation. Moreover, the mutant exhibited altered sensitivity to cell wall stressors and antifungal agents. When assayed using an in vitro keratinocyte infection model, virulence properties were also diminished. Our findings indicate that C. albicans TCA17 may be involved in secretion-related vesicle transport and plays a role in cell wall and vacuolar integrity, hyphal and biofilm formation, and virulence. IMPORTANCE The fungal pathogen Candida albicans causes serious opportunistic infections in immunocompromised patients and has become a major cause of hospital-acquired bloodstream infections, catheter-associated infections, and invasive disease. However, due to a limited understanding of Candida molecular pathogenesis, clinical approaches for the prevention, diagnosis, and treatment of invasive candidiasis need significant improvement. In this study, we focus on identifying and characterizing a gene potentially involved in the C. albicans secretory pathway, as intracellular transport is critical for C. albicans virulence. We specifically investigated the role of this gene in filamentation, biofilm formation, and tissue invasion. Ultimately, these findings advance our current understanding of C. albicans biology and may have implications for the diagnosis and treatment of candidiasis.}, }
@article {pmid37223347, year = {2022}, author = {Yoshida, M and Thiriet-Rupert, S and Mayer, L and Beloin, C and Ghigo, JM}, title = {Selection for nonspecific adhesion is a driver of FimH evolution increasing Escherichia coli biofilm capacity.}, journal = {microLife}, volume = {3}, number = {}, pages = {uqac001}, pmid = {37223347}, issn = {2633-6693}, abstract = {Bacterial interactions with surfaces rely on the coordinated expression of a vast repertoire of surface-exposed adhesins. However, how bacteria dynamically modulate their adhesion potential to achieve successful surface colonization is not yet well understood. Here, we investigated changes in adhesion capacity of an initially poorly adherent Escherichia coli strain using experimental evolution and positive selection for mutations improving adhesion and biofilm formation on abiotic surfaces. We showed that all identified evolved populations and clones acquired mutations located almost exclusively in the lectin domain of fimH, the gene coding for the α-d-mannose-specific tip adhesin of type 1 fimbriae, a key E. coli virulence factor. While most of these fimH mutants showed reduced mannose-binding ability, they all displayed enhanced binding to abiotic surfaces, indicating a trade-off between FimH-mediated specific and nonspecific adhesion properties. Several of the identified mutations were already reported in the FimH lectin domain of pathogenic and environmental E. coli, suggesting that, beyond pathoadaptation, FimH microevolution favoring nonspecific surface adhesion could constitute a selective advantage for natural E. coli isolates. Consistently, although E. coli deleted for the fim operon still evolves an increased adhesion capacity, mutants selected in the ∆fim background are outcompeted by fimH mutants revealing clonal interference for adhesion. Our study therefore provides insights into the plasticity of E. coli adhesion potential and shows that evolution of type 1 fimbriae is a major driver of the adaptation of natural E. coli to colonization.}, }
@article {pmid37222591, year = {2023}, author = {Morrisette, T and Stamper, KC and Lev, KL and Kebriaei, R and Holger, DJ and Abdul-Mutakabbir, JC and Kunz Coyne, AJ and Rybak, MJ}, title = {Evaluation of Omadacycline Alone and in Combination with Rifampin against Staphylococcus aureus and Staphylococcus epidermidis in an In Vitro Pharmacokinetic/Pharmacodynamic Biofilm Model.}, journal = {Antimicrobial agents and chemotherapy}, volume = {}, number = {}, pages = {e0131722}, doi = {10.1128/aac.01317-22}, pmid = {37222591}, issn = {1098-6596}, abstract = {Biofilm-associated infections lead to substantial morbidity. Omadacycline (OMC) is a novel aminomethylcycline with potent in vitro activity against Staphylococcus aureus and Staphylococcus epidermidis, but data surrounding its use in biofilm-associated infections are lacking. We investigated the activity of OMC alone and in combination with rifampin (RIF) against 20 clinical strains of staphylococci in multiple in vitro biofilm analyses, including an in vitro pharmacokinetic/pharmacodynamic (PK/PD) CDC biofilm reactor (CBR) model (simulating human exposures). The observed MICs for OMC demonstrated potent activity against the evaluated strains (0.125 to 1 mg/L), with an increase of MICs generally observed in the presence of biofilm (0.25 to >64 mg/L). Furthermore, RIF was shown to reduce OMC biofilm MICs (bMICs) in 90% of strains, and OMC plus RIF combination in biofilm time-kill analyses (TKAs) exhibited synergistic activity in most of the strains. Within the PK/PD CBR model, OMC monotherapy primarily displayed bacteriostatic activity, while RIF monotherapy generally exhibited initial bacterial eradication, followed by rapid regrowth likely due to the emergence of RIF resistance (RIF bMIC, >64 mg/L). However, the combination of OMC plus RIF produced rapid and sustained bactericidal activity in nearly all the strains (3.76 to 4.03 log10 CFU/cm[2] reductions from starting inoculum in strains in which bactericidal activity was reached). Furthermore, OMC was shown to prevent the emergence of RIF resistance. Our data provide preliminary evidence that OMC in combination with RIF could be a viable option for biofilm-associated infections with S. aureus and S. epidermidis. Further research involving OMC in biofilm-associated infections is warranted.}, }
@article {pmid37222310, year = {2023}, author = {Tkachuk, N and Zelena, L}, title = {Bacterial sulfidogenic community from the surface of technogenic materials in vitro: composition and biofilm formation.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-12}, doi = {10.1080/08927014.2023.2215694}, pmid = {37222310}, issn = {1029-2454}, abstract = {Microbial biofilms of sulfate-reducing bacteria Desulfovibrio oryzae SRB1 and SRB2 were evaluated on polyethylene terephthalate in mono- and associative bacterial cultures. Bacillus velesensis strains C1 and C2b suppressed both the formation of biofilm and reduced the number of sulfate-reducing bacteria in the biofilm on the polyethylene terephthalate during the 50-day experiment. A decrease in the number of sulfate-reducing bacteria compared to the monoculture was also noted in association of D. oryzae SRB1 + Sat1 (bacterium-satellite of the sulfate-reducing bacteria). The strain Sat1 was identified as Anaerotignum (Clostridium) propionicum based on some microbiological, physiological and biochemical, genetic features. The importance of studying existing interactions between microorganisms in the ferrosphere and plastisphere is emphasized.}, }
@article {pmid37221180, year = {2023}, author = {Noach, N and Lavy, E and Reifen, R and Friedman, M and Kirmayer, D and Zelinger, E and Ritter, A and Yaniv, D and Reifen, E}, title = {Zinc chloride is effective as an antibiotic in biofilm prevention following septoplasty.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {8344}, pmid = {37221180}, issn = {2045-2322}, abstract = {Biofilm-state bacterial infections associated with inserted medical devices constitute a massive health and financial problem worldwide. Although bacteria exhibit significantly lower susceptibility to antibiotics in the biofilm state, the most common treatment approach still relies on antibiotics, exacerbating the phenomenon of antibiotic-resistant bacteria. In this study, we aimed to assess whether ZnCl2 coating of intranasal silicone splints (ISSs) can reduce the biofilm infections associated with the insertion of these devices and prevent the overuse of antibiotics while minimizing waste, pollution and costs. We tested the ability of ZnCl2 to prevent biofilm formation on ISS both in vitro and in vivo by using the microtiter dish biofilm formation assay, crystal violet staining, and electron and confocal microscopy. We found a significant decrease in biofilm formation between the treatment group and the growth control when ZnCl2-coated splints were placed in patients' nasal flora. According to these results, infections associated with ISS insertion may be prevented by using ZnCl2 coating, thereby obviating the overuse and abuse of antibiotics.}, }
@article {pmid37220603, year = {2023}, author = {de Menezes, CLA and Boscolo, M and da Silva, R and Gomes, E and da Silva, RR}, title = {The degradation of chicken feathers by Ochrobactrum intermedium results in antioxidant and metal chelating hydrolysates and proteolytic enzymes for staphylococcal biofilm dispersion.}, journal = {3 Biotech}, volume = {13}, number = {6}, pages = {202}, pmid = {37220603}, issn = {2190-572X}, abstract = {The increase in the generation of chicken feathers, due to the large production of the poultry industry, has created the need to search for ecologically safer ways to manage these residues. As a sustainable alternative for recycling keratin waste, we investigated the ability of the bacterium Ochrobactrum intermedium to hydrolyze chicken feathers and the valorization of the resulting enzymes and protein hydrolysate. In submerged fermentation with three different inoculum sizes (2.5, 5.0, and 10.0 mg of bacterial cells per 50 mL of medium), the fastest degradation of feathers was achieved with 5.0 mg cells, in which a complete decomposition of the substrate (96 h) and earlier peaks of keratinolytic and caseinolytic activities were detected. In the resulting protein hydrolysate, we noticed antioxidant and Fe[2+] and Cu[2+] chelating activities. ABTS scavenging, Fe[3+]-reducing ability and metal chelating activities of the fermentative samples followed the same trend of feather degradation; as feather mass decreased in the media, these activities increased. Furthermore, we noticed about 47% and 60% dispersion of established 7-day biofilms formed by S. aureus after enzymatic treatment for 5 h and 24 h, respectively. These findings highlight the potential use of this bacterium as an environmentally friendly alternative to treat this poultry waste and offer valuable products.}, }
@article {pmid37217630, year = {2023}, author = {Zhao, W and Wang, Y and Bai, M}, title = {Nitrogen removal enhancement reinforced by nitritation/anammox in an anaerobic/oxic/anoxic system with integrated fixed biofilm activated sludge.}, journal = {Bioprocess and biosystems engineering}, volume = {}, number = {}, pages = {}, pmid = {37217630}, issn = {1615-7605}, abstract = {The enhancement of nitrogen removal was reinforced by nitritation/anammox in an anaerobic/oxic/anoxic (AOA) system of integrated fixed biofilm activated sludge. Nitritation was first attained by the method of free nitrous acid (FNA) inhibition with ammonia residues, and anaerobic ammonia oxidizing bacteria (AnAOB) were then added into the system, which enabled the occurrence of nitritation coupled with anaerobic ammonia oxidation (anammox). The results indicated that nitrogen removal was enhanced by the nitritation/anammox pathway with an efficiency of 88.9%. A microbial analysis showed that the ammonia oxidizing bacterium (AOB) Nitrosomonas was enriched on the biofilm (5.98%) and in the activated sludge (2.40%), and the AnAOB Candidatus Brocadia was detected on the biofilm with a proportion of 0.27%. Nitritation/anammox was attained and maintained due to the accumulation of functional bacteria.}, }
@article {pmid37217567, year = {2023}, author = {Wardani, AK and Buana, EOGHN and Sutrisno, A}, title = {The potency of bacteriophages isolated from chicken intestine and beef tribe to control biofilm-forming bacteria, Bacillus subtilis.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {8222}, pmid = {37217567}, issn = {2045-2322}, mesh = {Animals ; Cattle ; Bacillus subtilis ; *Bacteriophages ; Chickens ; Biofilms ; *Disinfectants ; }, abstract = {Biofilm becomes one of the crucial food safety problems in the food industry as the formation of biofilm can be a source of contamination. To deal with the problem, an industry generally employs physical and chemical methods including sanitizers, disinfectants, and antimicrobials to remove biofilm. However, the use of these methods may bring about new problems, which are bacterial resistance in the biofilm and the risk for product contamination. New strategies to deal with bacterial biofilms are needed. Bacteriophages (phages), as a green alternative to chemical, have re-emerged as a promising approach to treat bacterial biofilm. In the present study, the potential of lytic phages which have antibiofilm activity on biofilm-forming bacteria (Bacillus subtilis), were isolated from chicken intestines and beef tripe obtained from Indonesian traditional markets using host cells obtained isolated from these samples. Phages isolation was conducted by using double layer agar technique. A lytic test of phages was administered on biofilm-forming bacteria. The difference of turbidity level between control (which were not infected by phages) and the test tubes containing host bacteria infected by phages was investigated. The infection time for the production of phages was determined based on the level of clarity of the media in the test tube with a longer lysate addition time. Three phages were isolated namely: ϕBS6, ϕBS8, and ϕUA7. It showed the ability to inhibit B. subtilis as biofilm-forming spoilage bacteria. The best inhibition results were obtained from ϕBS6. Infection with ϕBS6 in B. subtilis lead to 0.5 log cycle decreased in bacterial cells. This study showed that isolated phages might be used as a potential approach for handling the problem of biofilm formation by B. subtilis.}, }
@article {pmid37217495, year = {2023}, author = {Cho, H and Ren, Z and Divaris, K and Roach, J and Lin, BM and Liu, C and Azcarate-Peril, MA and Simancas-Pallares, MA and Shrestha, P and Orlenko, A and Ginnis, J and North, KE and Zandona, AGF and Ribeiro, AA and Wu, D and Koo, H}, title = {Selenomonas sputigena acts as a pathobiont mediating spatial structure and biofilm virulence in early childhood caries.}, journal = {Nature communications}, volume = {14}, number = {1}, pages = {2919}, pmid = {37217495}, issn = {2041-1723}, mesh = {Male ; Child ; Female ; Humans ; Child, Preschool ; Virulence ; *Dental Caries Susceptibility ; *Streptococcus mutans/genetics ; Biofilms ; }, abstract = {Streptococcus mutans has been implicated as the primary pathogen in childhood caries (tooth decay). While the role of polymicrobial communities is appreciated, it remains unclear whether other microorganisms are active contributors or interact with pathogens. Here, we integrate multi-omics of supragingival biofilm (dental plaque) from 416 preschool-age children (208 males and 208 females) in a discovery-validation pipeline to identify disease-relevant inter-species interactions. Sixteen taxa associate with childhood caries in metagenomics-metatranscriptomics analyses. Using multiscale/computational imaging and virulence assays, we examine biofilm formation dynamics, spatial arrangement, and metabolic activity of Selenomonas sputigena, Prevotella salivae and Leptotrichia wadei, either individually or with S. mutans. We show that S. sputigena, a flagellated anaerobe with previously unknown role in supragingival biofilm, becomes trapped in streptococcal exoglucans, loses motility but actively proliferates to build a honeycomb-like multicellular-superstructure encapsulating S. mutans, enhancing acidogenesis. Rodent model experiments reveal an unrecognized ability of S. sputigena to colonize supragingival tooth surfaces. While incapable of causing caries on its own, when co-infected with S. mutans, S. sputigena causes extensive tooth enamel lesions and exacerbates disease severity in vivo. In summary, we discover a pathobiont cooperating with a known pathogen to build a unique spatial structure and heighten biofilm virulence in a prevalent human disease.}, }
@article {pmid37216726, year = {2023}, author = {Cohen, R and Mani, KA and Primatova, M and Jacobi, G and Zelinger, E and Belausov, E and Fallik, E and Banin, E and Mechrez, G}, title = {A green formulation for superhydrophobic coatings based on Pickering emulsion templating for anti-biofilm applications.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {227}, number = {}, pages = {113355}, doi = {10.1016/j.colsurfb.2023.113355}, pmid = {37216726}, issn = {1873-4367}, abstract = {This study reports significant steps toward developing anti-biofilm surfaces based on superhydrophobic properties that meet the complex demands of today's food and medical regulations. It presents inverse Pickering emulsions of water in dimethyl carbonate (DMC) stabilized by hydrophobic silica (R202) as a possible food-grade coating formulation and describes its significant passive anti-biofilm properties. The final coatings are formed by applying the emulsions on the target surface, followed by evaporation to form a rough layer. Analysis shows that the final coatings exhibited a Contact Angle (CA) of up to 155° and a Roll-off Angle (RA) lower than 1° on the polypropylene (PP) surface, along with a relatively high light transition. Dissolving polycaprolactone (PCL) into the continuous phase enhanced the average CA and coating uniformity but hindered the anti-biofilm activity and light transmission. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed a uniform coating by a "Swiss-cheese" like structure with high nanoscale and microscale roughness. Biofilm experiments confirm the coating's anti-biofilm abilities that led to the reduction in survival rates of S.aureus and E.coli, by 90-95% respectively, compared to uncoated PP surfaces.}, }
@article {pmid37216386, year = {2023}, author = {Kitts, G and Rogers, A and Teschler, JK and Park, JH and Trebino, MA and Chaudry, I and Erill, I and Yildiz, FH}, title = {The Rvv two-component regulatory system regulates biofilm formation and colonization in Vibrio cholerae.}, journal = {PLoS pathogens}, volume = {19}, number = {5}, pages = {e1011415}, doi = {10.1371/journal.ppat.1011415}, pmid = {37216386}, issn = {1553-7374}, abstract = {The facultative human pathogen, Vibrio cholerae, employs two-component signal transduction systems (TCS) to sense and respond to environmental signals encountered during its infection cycle. TCSs consist of a sensor histidine kinase (HK) and a response regulator (RR); the V. cholerae genome encodes 43 HKs and 49 RRs, of which 25 are predicted to be cognate pairs. Using deletion mutants of each HK gene, we analyzed the transcription of vpsL, a biofilm gene required for Vibrio polysaccharide and biofilm formation. We found that a V. cholerae TCS that had not been studied before, now termed Rvv, controls biofilm gene transcription. The Rvv TCS is part of a three-gene operon that is present in 30% of Vibrionales species. The rvv operon encodes RvvA, the HK; RvvB, the cognate RR; and RvvC, a protein of unknown function. Deletion of rvvA increased transcription of biofilm genes and altered biofilm formation, while deletion of rvvB or rvvC lead to no changes in biofilm gene transcription. The phenotypes observed in ΔrvvA depend on RvvB. Mutating RvvB to mimic constitutively active and inactive versions of the RR only impacted phenotypes in the ΔrvvA genetic background. Mutating the conserved residue required for kinase activity in RvvA did not affect phenotypes, whereas mutation of the conserved residue required for phosphatase activity mimicked the phenotype of the rvvA mutant. Furthermore, ΔrvvA displayed a significant colonization defect which was dependent on RvvB and RvvB phosphorylation state, but not on VPS production. We found that RvvA's phosphatase activity regulates biofilm gene transcription, biofilm formation, and colonization phenotypes. This is the first systematic analysis of the role of V. cholerae HKs in biofilm gene transcription and resulted in the identification of a new regulator of biofilm formation and virulence, advancing our understanding of the role TCSs play in regulating these critical cellular processes in V. cholerae.}, }
@article {pmid37214349, year = {2023}, author = {Auria, E and Deschamps, J and Briandet, R and Dupuy, B}, title = {Extracellular succinate induces spatially organized biofilm formation in Clostridioides difficile.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100125}, pmid = {37214349}, issn = {2590-2075}, abstract = {Clostridioides difficile infection associated to gut microbiome dysbiosis is the leading cause for nosocomial diarrhea. The ability of C. difficile to form biofilms has been progressively linked to its pathogenesis as well as its persistence in the gut. Although C. difficile has been reported to form biofilms in an increasing number of conditions, little is known about how these biofilms are formed in the gut and what factors may trigger their formation. Here we report that succinate, a metabolite abundantly produced by the dysbiotic gut microbiota, induces in vitro biofilm formation of C. difficile strains. We characterized the morphology and spatial composition of succinate-induced biofilms, and compared to non-induced or deoxycholate (DCA) induced biofilms. Biofilms induced by succinate are significantly thicker, structurally more complex, and poorer in proteins and exopolysaccharides (EPS). We then applied transcriptomics and genetics to characterize the early stages of succinate-induced biofilm formation and we showed that succinate-induced biofilm results from major metabolic shifts and cell-wall composition changes. Similar to DCA-induced biofilms, biofilms induced by succinate depend on the presence of a rapidly metabolized sugar. Finally, although succinate can be consumed by the bacteria, we found that the extracellular succinate is in fact responsible for the induction of biofilm formation through complex regulation involving global metabolic regulators and the osmotic stress response. Thus, our work suggests that as a gut signal, succinate may drive biofilm formation and help persistence of C. difficile in the gut, increasing the risk of relapse.}, }
@article {pmid37214032, year = {2023}, author = {Tsopmene, UJ and Iwewe, YS and Eyong, IM and Bisso, BN and Dzoyem, JP}, title = {Antibiotic Resistance Profile, Biofilm Formation Ability, and Virulence Factors Analysis of Three Staphylococcus spp. Isolates From Urine.}, journal = {Cureus}, volume = {15}, number = {4}, pages = {e37877}, pmid = {37214032}, issn = {2168-8184}, abstract = {Background Staphylococcus spp. is one of the most causative agents of urinary tract infections (UTIs). This study aimed to investigate the antibiotic resistance profile and the virulence factors, including the biofilm formation ability of Staphylococcus spp. isolates from urine. Methodology The agar disk diffusion method was used to test the susceptibility of Staphylococcus isolates to ten antibiotics. The biofilm formation ability was determined using the safranin microplate-based method, and the phospholipase, esterase, and hemolysin activities were assessed by the agar plate method. Results During the study period, a prevalence of 18.12% of urinary tract infections caused by the identified Staphylococci was obtained. All the isolated Staphylococcus aureus and S. epidermidis were resistant to cefazolin. Multi-drug resistance (MDR) was recorded in 80.01%, 81.49%, and 76.20% of S. aureus, S. epidermidis, and S. saprophyticus isolates, respectively. Most of the isolates were moderate biofilm formers, while 44.44%, 31.75%, and 30.16% were positive for phospholipase, esterase, and hemolysin activities, respectively. No relevant correlations were observed between the ability of biofilm formation and the resistance to antibiotics or the expression of virulence factors investigated. Conclusion This study shows that Staphylococcus spp. isolates from patients with clinical manifestations of UTIs expressed a high degree of virulence factors, including the ability of biofilm formation, and exhibited multi-drug resistance to the majority of antimicrobials commonly used for the treatment of Staphylococcal infections.}, }
@article {pmid37213696, year = {2023}, author = {Ahmad Ansari, F and Ahmad, I and Pichtel, J}, title = {Synergistic effects of biofilm-producing PGPR strains on wheat plant colonization, growth and soil resilience under drought stress.}, journal = {Saudi journal of biological sciences}, volume = {30}, number = {6}, pages = {103664}, pmid = {37213696}, issn = {1319-562X}, abstract = {Drought stress substantially impedes crop productivity throughout the world. Microbial based approaches have been considered a potential possibility and are under study. Based on our prior screening examination, two distinct and novel biofilm-forming PGPR strains namely Bacillus subtilis-FAB1 and Pseudomonas azotoformans-FAP3 are encompassed in this research. Bacterial biofilm development on glass surface, microtiter plate and seedling roots were assessed and characterized quantitatively and qualitatively by light and scanning electron microscopy. Above two isolates were further evaluated for their consistent performance by inoculating on wheat plants in a pot-soil system under water stresses. Bacterial moderate tolerance to ten-day drought was recorded on the application of individual strains with wheat plants; however, the FAB1 + FAP3 consortium expressively improved wheat survival during drought. The strains FAB1 and FAP3 displayed distinct and multifunctional plant growth stimulating attributes as well as effective roots and rhizosphere colonization in combination which could provide sustained wheat growth during drought. FAB1 and FAP3-induced alterations cooperatively conferred improved plant drought tolerance by controlling physiological traits (gs, Ci, E, iWUE and PN), stress indicators (SOD, CAT, GR, proline and MDA content) and also maintained physico-chemical attributes and hydrolytic enzymes including DHA, urease, ALP, protease, ACP and β glucosidase in the soil. Our findings could support future efforts to enhance plant drought tolerance by engineering the rhizobacterial biofilms and associated attributes which requires in-depth exploration and exploiting potential native strains for local agricultural application.}, }
@article {pmid37213612, year = {2023}, author = {Zdziarski, P and Paściak, M and Chudzik, A and Kozińska, M and Augustynowicz-Kopeć, E and Gamian, A}, title = {Cutaneous tuberculosis-ambiguous transmission, bacterial diversity with biofilm formation in humoral abnormality: case report illustration.}, journal = {Frontiers in public health}, volume = {11}, number = {}, pages = {1091373}, pmid = {37213612}, issn = {2296-2565}, abstract = {BACKGROUND: Cutaneous tuberculosis (CTB) and its paucibacillary forms are rare and difficult to diagnose, especially in immunocompromised patients with significant comorbidity. The aim of the study was to introduce the modern concept of the microbiome and diagnostic chain into clinical practice (patient-centered care) with the presentation of an atypical form of cutaneous tuberculosis with necrotizing non-healing ulcers leading to polymicrobial infection.<br><br>METHODS: The study material included samples from sputum, broncho-alveolar lavage and skin ulcer, taken from a patient developing cutaneous tuberculosis. The microbiological investigation was performed, and identification of the isolates was carried out using genotyping and the matrix-assisted laser desorption ionization-time of flight mass spectrometry.<br><br>RESULTS: The immunocompromised patient with humoral abnormality (plasma cell dyscrasia) and severe paraproteinemia developed multiorgan tuberculosis. Although cutaneous manifestation preceded systemic and pulmonary symptoms (approximately half a year), the mycobacterial genotyping confirmed the same MTB strain existence in skin ulcers and the respiratory system. Therefore, the infectious chain: transmission, the portal of entry, and bacterial spreading in vivo, were unclear. Microbial diversity found in wound microbiota (among others Gordonia bronchialis, Corynebacterium tuberculostearicum, Staphylococcus haemolyticus, and Pseudomonas oryzihabitans) was associated with the spread of a skin lesion. The in vitro biofilm-forming capacity of strains isolated from the wound may represent the potential virulence of these strains. Thus, the role of polymicrobial biofilm may be crucial in ulcer formation and CTB manifestation.<br><br>CONCLUSIONS: Severe wound healing as a unique biofilm-forming niche should be tested for Mycobacterium (on species and strain levels) and coexisting microorganisms using a wide range of microbiological techniques. In immunodeficient patients with non-typical CTB presentation, the chain of transmission and MTB spread is still an open issue for further research.}, }
@article {pmid37213153, year = {2023}, author = {Wu, Y and Yang, D}, title = {Effects of Bacterial Biofilm on Regulation of Neurovascular Unit Functions and Neuroinflammation of Patients with Ischemic Cerebral Stroke by Immunocyte.}, journal = {Cellular and molecular biology (Noisy-le-Grand, France)}, volume = {69}, number = {1}, pages = {81-86}, doi = {10.14715/cmb/2022.69.1.14}, pmid = {37213153}, issn = {1165-158X}, abstract = {In this experiment, the effects of biofilm on neurovascular unit functions and neuroinflammation of patients with ischemic cerebral stroke were investigated. For this purpose, 20 adult male rats were purchased from Taconic (8 to 10 weeks old, weighing between 20 and 24g) and selected as the research objects. Then, they were randomly divided into an experimental group (10 rats) and a control group (10 rats). Ischemic cerebral stroke rat models were established. Besides, pseudomonas aeruginosa (PAO1) was prepared manually and implanted into the bodies of rats in the experimental group. mNSS scores, cerebral infarction area, and the release of inflammatory cytokines of rats in the two groups were compared. Results showed that mNSS scores for rats in the experimental group at all periods were remarkably higher than those for rats in the control group (P<0.05), which demonstrated that the rats in the experimental group suffered much severer neurological impairment than those in the control group. In addition, the release of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, inducible nitric oxide synthase (iNOS), and IL-10 were all higher than those of the control group (P<0.05). The cerebral infarction area of the experimental group at all periods was remarkably larger than that of the control group (P<0.05). In conclusion, the formation of biofilm led to the aggravation of neurological impairment and inflammatory reactions among patients with ischemic cerebral stroke.}, }
@article {pmid37213152, year = {2023}, author = {Sun, H and Chai, X and Xu, G and Wei, S}, title = {The Formation and Drug Resistance Mechanism of Biofilm for Streptococcus pneumoniae Infection in Severe Respiratory Patients.}, journal = {Cellular and molecular biology (Noisy-le-Grand, France)}, volume = {69}, number = {1}, pages = {75-80}, doi = {10.14715/cmb/2022.69.1.13}, pmid = {37213152}, issn = {1165-158X}, abstract = {This study was to explore whether Streptococcus pneumoniae would form biofilms and the formative factors of biofilms, as well as the drug resistance mechanism of S. pneumoniae. In this study, a total of 150 strains of S. pneumoniae were collected from 5 local hospitals in the past two years, and the minimum inhibitory concentrations (MIC) of levofloxacin, moxifloxacin and penicillin were determined by agar double dilution method to select the drug-resistant strains. The polymerase chain reaction (PCR) amplification and sequencing were performed on specific genes of drug-resistant strains. In addition, 5 strains of S. pneumoniae with penicillin MIC ≤ 0.065 μg/mL, 0.5 μg/mL, 2 μg/mL, ≥ 4μg/mL were randomly selected, and the biofilms were cultured on two kinds of well plates for 24 hours. Finally, whether the biofilms were formed was observed. Experimental results revealed that the resistance rate of S. pneumoniae to erythromycin in this area was as high as 90.3%, and the strains that were resistant to penicillin account for only 1.5%. The amplification and sequencing experiment revealed that one (strain 1) of the strains, which was resistant to both drugs, had a GyrA mutation and ParE mutation, and strain 2 had a parC mutation. All strains generated biofilms, and the optical density (OD) value of penicillin MIC ≤ 0.065 μg/mL group (0.235 ± 0.053) was higher than that of 0.5 μg/mL group (0.192 ± 0.073) (P< 0.05) and higher than the OD value of the 4 μg/mL group (0.200 ± 0.041) (P< 0.05), showing statistically great differences. It was confirmed that the resistance rate of S. pneumoniae to erythromycin remained high, the rate of sensitivity to penicillin was relatively high, and the moxifloxacin and levofloxacin-resistant strains had appeared; S. pneumoniae mainly showed QRDR mutations in gyrA, parE, and parC; and it was confirmed that S. pneumoniae can generate biofilms in vitro.}, }
@article {pmid37212952, year = {2023}, author = {Seebach, E and Elschner, T and Kraus, FV and Souto-Carneiro, M and Kubatzky, KF}, title = {Bacterial and Metabolic Factors of Staphylococcal Planktonic and Biofilm Environments Differentially Regulate Macrophage Immune Activation.}, journal = {Inflammation}, volume = {}, number = {}, pages = {}, pmid = {37212952}, issn = {1573-2576}, abstract = {Biofilm formation is a leading cause for chronic implant-related bone infections as biofilms shield bacteria against the immune system and antibiotics. Additionally, biofilms generate a metabolic microenvironment that shifts the immune response towards tolerance. Here, we compared the impact of the metabolite profile of bacterial environments on macrophage immune activation using Staphylococcus aureus (SA) and epidermidis (SE) conditioned media (CM) of planktonic and biofilm cultures. The biofilm environment had reduced glucose and increased lactate concentrations. Moreover, the expression of typical immune activation markers on macrophages was reduced in the biofilm environment compared to the respective planktonic CM. However, all CM caused a predominantly pro-inflammatory macrophage cytokine response with a comparable induction of Tnfa expression. In biofilm CM, this was accompanied by higher levels of anti-inflammatory Il10. Planktonic CM, on the other hand, induced an IRF7 mediated Ifnb gene expression which was absent in the biofilm environments. For SA but not for SE planktonic CM, this was accompanied by IRF3 activation. Stimulation of macrophages with TLR-2/-9 ligands under varying metabolic conditions revealed that, like in the biofilm setting, low glucose concentration reduced the Tnfa to Il10 mRNA ratio. However, the addition of extracellular L-lactate but not D-lactate increased the Tnfa to Il10 mRNA ratio upon TLR-2/-9 stimulation. In summary, our data indicate that the mechanisms behind the activation of macrophages differ between planktonic and biofilm environments. These differences are independent of the metabolite profiles, suggesting that the production of different bacterial factors is ultimately more important than the concentrations of glucose and lactate in the environment.}, }
@article {pmid37212713, year = {2023}, author = {Wang, K and Deng, Y and Cui, X and Chen, M and Ou, Y and Li, D and Guo, M and Li, W}, title = {PatA Regulates Isoniazid Resistance by Mediating Mycolic Acid Synthesis and Controls Biofilm Formation by Affecting Lipid Synthesis in Mycobacteria.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0092823}, doi = {10.1128/spectrum.00928-23}, pmid = {37212713}, issn = {2165-0497}, abstract = {Lipids are prominent components of the mycobacterial cell wall, and they play critical roles not only in maintaining biofilm formation but also in resisting environmental stress, including drug resistance. However, information regarding the mechanism mediating mycobacterial lipid synthesis remains limited. PatA is a membrane-associated acyltransferase and synthesizes phosphatidyl-myo-inositol mannosides (PIMs) in mycobacteria. Here, we found that PatA could regulate the synthesis of lipids (except mycolic acids) to maintain biofilm formation and environmental stress resistance in Mycolicibacterium smegmatis. Interestingly, the deletion of patA significantly enhanced isoniazid (INH) resistance in M. smegmatis, although it reduced bacterial biofilm formation. This might be due to the fact that the patA deletion promoted the synthesis of mycolic acids through an unknown synthesis pathway other than the reported fatty acid synthase (FAS) pathway, which could effectively counteract the inhibition by INH of mycolic acid synthesis in mycobacteria. Furthermore, the amino acid sequences and physiological functions of PatA were highly conserved in mycobacteria. Therefore, we found a mycolic acid synthesis pathway regulated by PatA in mycobacteria. In addition, PatA also affected biofilm formation and environmental stress resistance by regulating the synthesis of lipids (except mycolic acids) in mycobacteria. IMPORTANCE Tuberculosis, caused by Mycobacterium tuberculosis, leads to a large number of human deaths every year. This is so serious, which is due mainly to the drug resistance of mycobacteria. INH kills M. tuberculosis by inhibiting the synthesis of mycolic acids, which are synthesized by the FAS pathway. However, whether there is another mycolic acid synthesis pathway is unknown. In this study, we found a PatA-mediated mycolic acid synthesis pathway that led to INH resistance of in patA-deleted mutant. In addition, we first report the regulatory effect of PatA on mycobacterial biofilm formation, which could affect the bacterial response to environmental stress. Our findings represent a new model for regulating biofilm formation by mycobacteria. More importantly, the discovery of the PatA-mediated mycolic acid synthesis pathway indicates that the study of mycobacterial lipids has entered a new stage, and the enzymes might be new targets of antituberculosis drugs.}, }
@article {pmid37211854, year = {2023}, author = {Var, I and AlMatar, M and Heshmati, B and Albarri, O}, title = {Bacteriophage Cocktail Can Effectively Control Salmonella Biofilm on Gallstone and Tooth Surfaces.}, journal = {Current drug targets}, volume = {}, number = {}, pages = {}, doi = {10.2174/1389450124666230519121940}, pmid = {37211854}, issn = {1873-5592}, abstract = {Salmonellosis, which is typically distinguished by an immediate onset of fever, abdominal pain, diarrhea, nausea, and vomiting, is a bacterial infection caused by Salmonella. The rising incidence of antibiotic resistance in Salmonella Typhimurium is a major worldwide problem, and a better knowledge of the distribution of antibiotic resistance patterns in Salmonella Typhimurium is critical for selecting the best antibiotic for infection treatment. In this work, the efficiency of bacteriophage therapy of vegetative cells and biofilms of S. Typhimurium was investigated. Based on their host ranges, five Bacteriophages were chosen for therapy against 22 Salmonella isolates collected from various sources. PSCs1, PSDs1, PSCs2, PSSr1, and PSMc1 phages were found to exhibit potent anti-S. Typhimurium properties. In a 96-well microplate, the efficacy of bacteriophage therapy (105-1011 PFU/mL) against S. Typhimurium biofilm formers was first tested. A bacteriophage treatment (109 PFU/mL) was subsequently applied in the laboratory for 24 hours to minimize Salmonella adhering to the surfaces of gallstones and teeth. In 96-well microplate experiments, bacteriophage treatment inhibited biofilm development and reduced biofilm by up to 63.6% (P ≤ 0.05). When compared to controls, bacteriophages (PSCs1, PSDs1, PSCs2, PSSr1, PSMc1) demonstrated a rapid drop in the populations of S. Typhimurium biofilms generated on the surfaces of gallstones and teeth where the structure of the Salmonella bacteria in the biofilm was broken and holes were created. Clearly, this study indicated that phages might be employed to eliminate S. Typhimurium biofilms on gallstone and tooth surfaces.}, }
@article {pmid37211593, year = {2023}, author = {Eghbalifam, N and Shojaosadati, SA and Hashemi-Najafabadi, S}, title = {Role of bioactive magnetic nanoparticles in the prevention of wound pathogenic biofilm formation using smart nanocomposites.}, journal = {Journal of nanobiotechnology}, volume = {21}, number = {1}, pages = {161}, pmid = {37211593}, issn = {1477-3155}, abstract = {BACKGROUND: Biofilm formation and its resistance to various antibiotics is a serious health problem in the treatment of wound infections. An ideal wound dressing should have characteristics such as protection of wound from microbial infection, suitable porosity (to absorb wound exudates), proper permeability (to maintain wound moisture), nontoxicity, and biocompatibility. Although silver nanoparticles (AgNPs) have been investigated as antimicrobial agents, their limitations in penetrating into the biofilm, affecting their efficiency, have consistently been an area for further research.<br><br>RESULTS: Consequently, in this study, the optimal amounts of natural and synthetic polymers combination, along with AgNPs, accompanied by iron oxide nanoparticles (IONPs), were utilized to fabricate a smart bionanocomposite that meets all the requirements of an ideal wound dressing. Superparamagnetic IONPs (with the average size of 11.8&#xa0;nm) were synthesized through co-precipitation method using oleic acid to improve their stability. It was found that the addition of IONPs to bionanocomposites had a synergistic effect on their antibacterial and antibiofilm properties. Cytotoxicity assay results showed that nanoparticles does not considerably affect eukaryotic cells compared to prokaryotic cells. Based on the images obtained by confocal laser scanning microscopy (CLSM), significant AgNPs release was observed when an external magnetic field (EMF) was applied to the bionanocomposites loaded with IONPs, which increased the antibacterial activity and inhibited the formation of biofilm significantly.<br><br>CONCLUSION: These finding indicated that the nanocomposite recommended can have an efficient properties for the management of wounds through prevention and treatment of antibiotic-resistant biofilm.}, }
@article {pmid37211260, year = {2023}, author = {Benavent, E and Ulldemolins, M and Haj, CE and Rigo-Bonnin, R and Yu, H and Wang, L and Wickremasinghe, H and Ariza, J and Murillo, O}, title = {Efficacy of meropenem extended infusion vs. intermittent bolus monotherapy and its combinations with colistin against Pseudomonas aeruginosa biofilm.}, journal = {International journal of antimicrobial agents}, volume = {}, number = {}, pages = {106856}, doi = {10.1016/j.ijantimicag.2023.106856}, pmid = {37211260}, issn = {1872-7913}, abstract = {INTRODUCTION: Device-related infections are difficult-to-treat due to biofilms. In this setting, optimizing the antibiotic efficacy is difficult since most PK/PD studies have been performed on planktonic cells, and therapies are limited when multidrug-resistant bacteria are involved. We aimed to analyze the PK/PD indices of meropenem predicting anti-biofilm efficacy against meropenem-susceptible and -resistant P. aeruginosa strains.<br><br>MATERIAL AND METHODS: Pharmacodynamics of meropenem dosages mimicking those of clinical practice (intermittent bolus of 2g every 8h; extended infusion of 2g over 4h every 8h), with and without colistin, were evaluated with the CDC Biofilm Reactor in vitro model for susceptible (PAO1) and extensively drug resistant (XDR-HUB3) P. aeruginosa. Efficacy was correlated with the pharmacokinetic/pharmacodynamic indices for meropenem.<br><br>RESULTS: Concerning PAO1, both meropenem regimens were bactericidal, with higher killing for the extended infusion (&#x2206;log10 CFU/mL 54-0h=-4.66&#xb1;0.93 and &#x2206;log10 CFU/mL 54-0h=-3.4&#xb1;0.41 for intermittent bolus; p<0.001). Concerning XDR-HUB3, meropenem by intermittent bolus was non-active whereas it showed bactericidal effect by extended infusion (&#x2206;log10 CFU/mL 54-0h=-3.65&#xb1;0.29; p<0.001). Time above minimum inhibitory concentration (f%T>MIC) had the best correlation with efficacy for both strains. Adding colistin always improved meropenem activity and resistant-strains did not emerge.<br><br>CONCLUSION: The&#xa0;f%T>MIC was the PK/PD index that best correlated with the anti-biofilm efficacy of meropenem; it was better optimized when using extended infusion, allowing to recover bactericidal activity in monotherapy also against meropenem-resistant&#xa0;P. aeruginosa.&#xa0;Combining meropenem&#xa0;by extended infusion&#xa0;with colistin offered the most effective therapy for both strains. Optimizing meropenem dosing by extended infusion should be encouraged when treating biofilm-related infections.}, }
@article {pmid37211213, year = {2023}, author = {Queraltó, C and Ortega, C and Díaz-Yáñez, F and Inostroza, O and Espinoza, G and Álvarez, R and González, R and Parra, F and Paredes-Sabja, D and Acuña, LG and Calderón, IL and Fuentes, JA and Gil, F}, title = {The chaperone ClpC participates in sporulation, motility, biofilm, and toxin production of Clostridioides difficile.}, journal = {Journal of global antimicrobial resistance}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jgar.2023.05.004}, pmid = {37211213}, issn = {2213-7173}, abstract = {UNLABELLED: Clostridioides difficile is a nosocomial pathogen that is associated with the use of antibiotics. One of the most worrying aspects of C. difficile infection is its ability to resist antimicrobial therapies due to spore formation. In several bacterial pathogens, proteases of the Clp family participate in phenotypes associated with persistence and virulence. This suggests that these proteins could be involved in virulence-related traits.<br><br>OBJECTIVES: In this study, we analyzed the role of ClpC chaperone-protease of C. difficile in virulence-related traits by comparing the phenotypes of a wild-type and a mutant strain lacking the clpC gene (&#x394;clpC).<br><br>METHODS: We performed biofilm, motility, spore formation, and cytotoxicity assays.<br><br>RESULTS: Our results show significant differences between the wild-type and &#x394;clpC strains in all analyzed parameters.<br><br>CONCLUSIONS: Based on these findings, we conclude that clpC plays a role in the virulence properties of C. difficile.}, }
@article {pmid37211134, year = {2023}, author = {Saint-Aimé, R and Guittonny, M and Neculita, CM}, title = {Valorization potential of N-rich zeolite and moving bed biofilm reactor (MBBR) biomass in the revegetation of non-acid generating gold mine tailings.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {164279}, doi = {10.1016/j.scitotenv.2023.164279}, pmid = {37211134}, issn = {1879-1026}, abstract = {Treatment of ammonia nitrogen (NH3-N) in mine effluents generates N-rich residual materials, such as moving bed biofilm reactor (MBBR) biomass and spent zeolite. Using them as substitutes for mineral fertilizers in revegetation of mine tailings avoids disposal and contributes to a circular economy. The study evaluated the effect of MBBR biomass and N-rich zeolite amendments on above- and below-ground growth and foliar nutrient and trace element concentrations of a legume and several graminoid species grown on non-acid generating gold mine tailings. N-rich zeolite (clinoptilolite) was produced by treating saline (up to 60 mS/cm) synthetic and real mine effluents (250 vs 280 mg/L NH3-N). A three-month pot experiment was conducted with a dose of tested amendments equivalent to 100 kg/ha N and compared to unamended tailings (as negative control), tailings with a mineral NPK fertilizer, and a topsoil (as positive controls). Higher foliar N concentrations were found in amended and fertilized tailings vs negative control, but N was less available in the zeolite treatments than in other tailings treatments. For all plant species, the mean leaf area and above-ground, root, and total biomasses were similar in the zeolite-amended tailings to the unamended tailings, while the MBBR biomass amendment resulted in similar above- and below-ground growth to the NPK fertilized tailings and the commercial topsoil. Trace metal concentrations in water leaching from the amended tailings remained low, but tailings amended with zeolite exported NO3-N concentrations up to 10 times greater (>200 mg/L) after 28 days compared to all other treatments. Foliar Na concentrations in zeolite mixtures were six to nine times higher than in other treatments. The MBBR biomass is a promising potential amendment for revegetation of mine tailings. However, Se concentrations in plants after MBBR biomass amendment should not be underestimated, while Cr transfer from tailings to plants was observed.}, }
@article {pmid37210905, year = {2023}, author = {Ferreres, G and Ivanova, K and Torrent-Burgués, J and Tzanov, T}, title = {Multimodal silver-chitosan-acylase nanoparticles inhibit bacterial growth and biofilm formation by Gram-negative Pseudomonas aeruginosa bacterium.}, journal = {Journal of colloid and interface science}, volume = {646}, number = {}, pages = {576-586}, doi = {10.1016/j.jcis.2023.04.184}, pmid = {37210905}, issn = {1095-7103}, abstract = {Pseudomonas aeruginosa bacteria originate severe infections in hospitalized patients and those with chronic debilitating diseases leading to increased morbidity and mortality, longer hospitalization and huge financial burden to the healthcare system. The clinical relevance of P. aeruginosa infections is increased by the capability of this bacterium to grow in biofilms and develop multidrug resistant mechanisms that preclude conventional antibiotic treatments. Herein, we engineered novel multimodal nanocomposites that integrate in the same entity antimicrobial silver nanoparticles (NPs), the intrinsically antimicrobial, but biocompatible biopolymer chitosan, and the anti-infective quorum quenching enzyme acylase I. Acylase present in the NPs specifically degraded the signal molecules governing bacterial cell-to-cell communication and inhibited by ∼ 55 % P. aeruginosa biofilm formation, while the silver/chitosan template altered the integrity of bacterial membrane, leading to complete eradication of planktonic bacteria. The innovative combination of multiple bacteria targeting modalities resulted in 100-fold synergistic enhancement of the antimicrobial efficacy of the nanocomposite at lower and non-hazardous towards human skin cells concentrations, compared to the silver/chitosan NPs alone.}, }
@article {pmid37210603, year = {2023}, author = {Fei, F and Wang, T and Jiang, Y and Chen, X and Ma, C and Zhou, M and Wu, Q and Cao, P and Duan, J and Chen, T and Burrows, JF and Wang, L}, title = {A frog-derived antimicrobial peptide as a potential anti-biofilm agent in combating Staphylococcus aureus skin infection.}, journal = {Journal of cellular and molecular medicine}, volume = {}, number = {}, pages = {}, doi = {10.1111/jcmm.17785}, pmid = {37210603}, issn = {1582-4934}, abstract = {Staphylococcus aureus (S. aureus), one of the most prevalent bacteria found in atopic dermatitis lesions, can induce ongoing infections and inflammation by downregulating the expression of host defence peptides in the skin. In addition, the emergence of the 'superbug' Methicillin-resistant S. aureus (MRSA) has made the treatment of these infections more challenging. Antimicrobial peptides (AMPs), due to their potent antimicrobial activity, limited evidence of resistance development, and potential immunomodulatory effects, have gained increasing attention as potential therapeutic agents for atopic dermatitis. In this study, we report a novel AMP, brevinin-1E-OG9, isolated from the skin secretions of Odorrana grahami, which shows potent antibacterial activity, especially against S. aureus. Based on the characteristics of the 'Rana Box', we designed a set of brevinin-1E-OG9 analogues to explore its structure-activity relationship. Brevinin-1E-OG9c-De-NH2 exhibited the most potent antimicrobial efficacy in both in vitro and ex vivo studies and attenuated inflammatory responses induced by lipoteichoic acid and heat-killed microbes. As a result, brevinin-1E-OG9c-De-NH2 might represent a promising candidate for the treatment of S. aureus skin infections.}, }
@article {pmid37210035, year = {2023}, author = {Wu, KK and Zhao, L and Zheng, XC and Sun, ZF and Wang, ZH and Chen, C and Xing, DF and Yang, SS and Ren, NQ}, title = {Recovery of methane and acetate during ex-situ biogas upgrading via novel dual-membrane aerated biofilm reactor.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {129181}, doi = {10.1016/j.biortech.2023.129181}, pmid = {37210035}, issn = {1873-2976}, abstract = {Biological biogas upgrading has been well-proven to be a promising approach for renewable bioenergy recovery, but hydrogen (H2)-assisted ex-situ biogas upgrading is hindered by a large solubility discrepancy between H2 and carbon dioxide (CO2). This study established a new dual-membrane aerated biofilm reactor (dMBfR) to improve the upgrading efficiency. Results showed that dMBfR operated at 1.25 atm H2 partial pressure, 1.5 atm biogas partial pressure, and 1.0 d hydraulic retention time could significantly improve the efficiency. The maximum methane purity of 97.6%, acetate production rate of 34.5 mmol L[-1]d[-1], and H2 and CO2 utilization ratios of 96.5% and 96.3% were achieved. Further analysis showed that the improved performances of biogas upgrading and acetate recovery were positively correlated with the total abundances of functional microorganisms. Taken together, these results suggest that the dMBfR, which facilitates the precise CO2 and H2 supply, is an ideal approach for efficient biological biogas upgrading.}, }
@article {pmid37209516, year = {2023}, author = {Cui, Y and Gao, J and Zhao, M and Guo, Y and Zhao, Y and Wang, Z}, title = {Deciphering the interaction impacts between antiseptic benzethonium chloride and biofilm nitrification system: Performance, resistance mechanisms and biodegradation.}, journal = {Water research}, volume = {240}, number = {}, pages = {120062}, doi = {10.1016/j.watres.2023.120062}, pmid = {37209516}, issn = {1879-2448}, abstract = {Benzethonium chloride (BEC) is one of emerging bacteriostatic agents. BEC-bearing wastewater generated during sanitary applications in food and medication is easily combined with other wastewater streams to flow into wastewater treatment plants. This study focused on the long-term (231 days) impacts of BEC on the sequencing moving bed biofilm nitrification system. Nitrification performance was tolerant to low concentration of BEC (≤ 0.2 mg/L), but the nitrite oxidation was severely inhibited when the concentration of BEC was 1.0-2.0 mg/L. Partial nitrification maintained about 140 days with nitrite accumulation ratio over 80%, mainly caused by the inhibition of Nitrospira, Nitrotoga and Comammox. Notably, BEC exposure in the system might cause the co-selection of antibiotic resistance genes (ARGs) and disinfectant resistance genes (DRGs), and the resistance of biofilm system to BEC was strengthened by efflux pumps mechanism (qacEdelta1 and qacH) and antibiotic deactivation mechanism (aadA, aac(6')-Ib and blaTEM). Extracellular polymeric substances secretion and BEC biodegradation were also contributed to the system microorganisms resisting BEC exposure. In addition, Klebsiella, Enterobacter, Citrobacter and Pseudomonas were isolated and identified as BEC degrading bacteria. The metabolites of N,N-dimethylbenzylamine, N-benzylmethylamine and benzoic acid were identified, and the biodegradation pathway of BEC was proposed. This study brought new knowledge about the fate of BEC in biological treatment units and laid a foundation for its elimination from wastewater.}, }
@article {pmid37209244, year = {2023}, author = {Karley, D and Shukla, SK and Rao, TS}, title = {Sequestration of cobalt and nickel by biofilm forming bacteria isolated from spent nuclear fuel pool water.}, journal = {Environmental monitoring and assessment}, volume = {195}, number = {6}, pages = {699}, pmid = {37209244}, issn = {1573-2959}, abstract = {In the current study, six bacterial types, isolated from spent nuclear fuel (SNF) pool facility, were investigated for their ability to sequester heavy metals (cobalt and nickel). Biofilm formation by the six bacterial isolates, viz., Bacillus subtilis, Staphylococcus species, Staphylococcus arlettae, Staphylococcus epidermidis, Staphylococcus auricularis, and Chryseobacterium gleum, were assayed, and they were found to have significant biofilm forming property. Their biofilms were characterised using confocal scanning laser microscopy, and their potential to accumulate Co[2+] and Ni[2+] from bulk solutions was analysed with respect to time. A comparative assessment of bioaccumulation capacity was done using biofilms, planktonic cells, and live vs dead cells. The strains accumulated Co[2+] and Ni[2+] in the range of 4 × 10[-4] to 1 × 10[-5] g/mg of cell biomass. It is interesting to note that dead biomass also showed significant removal of the two metal ions, suggesting an alternative process for metal removal. This study suggests that hostile environments can be a repertoire of putative bacterial species with potential heavy metals and other contaminants remediation properties.}, }
@article {pmid37207853, year = {2023}, author = {Çam, S and Küçük, &#xc7; and Almaca, A}, title = {Bacillus strains exhibit various plant growth promoting traits and their biofilm-forming capability correlates to their salt stress alleviation effect on maize seedlings.}, journal = {Journal of biotechnology}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jbiotec.2023.05.004}, pmid = {37207853}, issn = {1873-4863}, abstract = {Soil salinity interferes with plant growth and development. Bacillus genus has been used to increase the growth and productivity of a wide variety of crops by alleviating the effects of salt stress. A total of thirty two Bacillus isolates were obtained from maize rhizosphere, and their plant growth-promoting (PGP) traits and biocontrol activities were tested. Bacillus isolates displayed varying degrees of PGP properties-the production of extracellular enzymes, indole acetic acid, hydrogen cyanide, phosphate solubilization, biofilm formation, and antifungal potential against several fungal pathogens. The phosphate-solubilizing isolates belong to B. safensis, B. thuringiensis, B. cereus, and B. megaterium species. Each Bacillus isolate demonstrated different levels of antifungal activity against the fungal pathogens tested. Biofilm production by some salt-tolerant isolates significantly increased at elevated levels of NaCl (p<0.05). The strains B. safensis B24, B. halotolerans B7/B18, B. subtilis B26, and B. thuringiensis B10 significantly increased the length of root (by 32.7-38.2%) and shoot (by 19.5-29.8%) of maize (p<0.05). Maize plants treated with some Bacillus strains displayed significantly greater chlorophyll content with an increase of 26.7-32.1% (p <0.05). Among PGP properties, enhanced biofilm formation played a more important role in maize growth under higher salinity. These salt-tolerant biofilm-forming strains could be efficiently used as bio-inoculant for maize under salinity stress.}, }
@article {pmid37207779, year = {2023}, author = {Chen, X and Li, D and Zhou, C and Liu, X and Liu, G}, title = {Predation preference for extracellular polysaccharides by paramecia and rotifers may have accelerated the decline of membrane biofilm hydraulic resistance.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {164090}, doi = {10.1016/j.scitotenv.2023.164090}, pmid = {37207779}, issn = {1879-1026}, abstract = {The hydraulic resistance of biofilm layer on membranes impacts the filtration resistance significantly. The effect of predation by two model microfauna (i.e., paramecia and rotifers) on the hydraulic resistance, structure, extracellular polymeric substance (EPS), and bacterial community of biofilms developed on supporting materials (i.e., nylon mesh) was evaluated in this study. Long-term experiments demonstrated that predation could alter biofilm compositions and accelerated the decline of hydraulic resistance by increasing biofilm heterogeneity and deformation. Importantly, predation preference of paramecia and rotifers on biofilm components were further investigated for the first time by tracking the fluorescence change in the predator bodies after exposure to the stained biofilms. Results indicated that after 12-hour's incubation, the ratio of extracellular α-polysaccharides (α-PS) to proteins (PN) within the bodies of paramecia and rotifers increased to 2.6 and 3.9, respectively, which was 0.76 in the original biofilms. The ratios of α-PS/live cells within paramecia and rotifers increased to 1.42 and 1.64 from 0.81 in the original biofilms. The ratio of live/dead cells in the predator bodies, however, changed slightly compared to the original biofilms. These results clearly and directly evidenced that both paramecia and rotifers could feed on biofilm EPS and cells, but having a significant preference for PS over PN and cells. Since extracellular PS is recognized as a primary biofilm adhesion agent, the preference for PS could better explain why predation had accelerated the disintegration and hydraulic resistance decline of mesh biofilms.}, }
@article {pmid37206316, year = {2023}, author = {Nandy, A and Farkas, D and Pepió-Tárrega, B and Martinez-Crespiera, S and Borràs, E and Avignone-Rossa, C and Di Lorenzo, M}, title = {Influence of carbon-based cathodes on biofilm composition and electrochemical performance in soil microbial fuel cells.}, journal = {Environmental science and ecotechnology}, volume = {16}, number = {}, pages = {100276}, pmid = {37206316}, issn = {2666-4984}, abstract = {Increasing energy demands and environmental pollution concerns press for sustainable and environmentally friendly technologies. Soil microbial fuel cell (SMFC) technology has great potential for carbon-neutral bioenergy generation and self-powered electrochemical bioremediation. In this study, an in-depth assessment on the effect of several carbon-based cathode materials on the electrochemical performance of SMFCs is provided for the first time. An innovative carbon nanofibers electrode doped with Fe (CNFFe) is used as cathode material in membrane-less SMFCs, and the performance of the resulting device is compared with SMFCs implementing either Pt-doped carbon cloth (PtC), carbon cloth, or graphite felt (GF) as the cathode. Electrochemical analyses are integrated with microbial analyses to assess the impact on both electrogenesis and microbial composition of the anodic and cathodic biofilm. The results show that CNFFe and PtC generate very stable performances, with a peak power density (with respect to the cathode geometric area) of 25.5 and 30.4 mW m[-2], respectively. The best electrochemical performance was obtained with GF, with a peak power density of 87.3 mW m[-2]. Taxonomic profiling of the microbial communities revealed differences between anodic and cathodic communities. The anodes were predominantly enriched with Geobacter and Pseudomonas species, while cathodic communities were dominated by hydrogen-producing and hydrogenotrophic bacteria, indicating H2 cycling as a possible electron transfer mechanism. The presence of nitrate-reducing bacteria, combined with the results of cyclic voltammograms, suggests microbial nitrate reduction occurred on GF cathodes. The results of this study can contribute to the development of effective SMFC design strategies for field implementation.}, }
@article {pmid37205937, year = {2023}, author = {Khoshnood, S and Akrami, S and Saki, M and Motahar, M and Masihzadeh, S and Daneshfar, S and Meghdadi, H and Abbasi Montazeri, E and Abdi, M and Farshadzadeh, Z}, title = {Molecular evaluation of aminoglycosides resistance and biofilm formation in Klebsiella pneumoniae clinical isolates: A cross-sectional study.}, journal = {Health science reports}, volume = {6}, number = {5}, pages = {e1266}, pmid = {37205937}, issn = {2398-8835}, abstract = {BACKGROUND AND AIMS: Resistance to antibiotics and the capability to develop biofilm as two main virulent determinants of Klebsiella pneumoniae have important role in infection persistence. The aim of the study was to evaluate the association between the prevalence of aminoglycoside resistance and virulence genes and biofilm formation capacity in K. pneumoniae strains isolated from hospitalized patients in South-West of Iran.<br><br>METHODS: A total of 114 non-duplicate clinical isolates of K. pneumoniae collected from Ahvaz teaching hospitals. Identification of species was performed by biochemical tests and then confirmed by polymerase chain reaction&#xa0;(PCR) of rpoB gene. The susceptibility to antibiotics was determined by Kirby-Bauer disk diffusion method. Biofilm formation was assessed by microtiter plate method. Finally, PCR was conducted to detect virulence gene determinants including fimbrial genes, aminoglycoside modifying enzymes- and 16S rRNA methylase (RMTase) genes.<br><br>RESULTS: Totally, all collected strains were carbapenem resistant and showed multidrug- and extensively drug-resistance phenotype (75% and 25%, respectively). Seventy-one percent (n&#x2009;=&#x2009;81) of isolates were non-susceptible to aminoglycosides. Among aminoglycoside antibiotics, K. pneumoniae isolates showed the highest and lowest resistance rates to tobramycin (71%) and the amikacin (25%), respectively. All biofilm producer strains were positive for the presence virulence determinants including ecpA, fimA, mrkD, and mrkA. Of 81 aminoglycosides non-susceptible isolates 33% were positive for the presence ant (2&#x2033;)-Ia as the most prevalent gene followed by aac (3')-IIa and armA (27%), aac (6')-Ib (18%), and aph (3')-Ia (15%).<br><br>CONCLUSION: K. pneumoniae isolates showed the highest and the lowest aminoglycoside resistance rates to tobramycin and amikacin, respectively. Majority of isolates were biofilm producers and there was significant association between antibiotic resistance pattern and the strength of biofilm production. The ant(2&#x2033;)-Ia, aac (3')-IIa, and armA genes in aminoglycoside-resistant isolates.}, }
@article {pmid37205794, year = {2023}, author = {Markale, I and Carrel, M and Kurz, DL and Morales, VL and Holzner, M and Jiménez-Martínez, J}, title = {Internal Biofilm Heterogeneities Enhance Solute Mixing and Chemical Reactions in Porous Media.}, journal = {Environmental science &amp; technology}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.est.2c09082}, pmid = {37205794}, issn = {1520-5851}, abstract = {Bacterial biofilms can form in porous media that are of interest in industrial applications ranging from medical implants to biofilters as well as in environmental applications such as in situ groundwater remediation, where they can be critical locations for biogeochemical reactions. The presence of biofilms modifies porous media topology and hydrodynamics by clogging pores and consequently solutes transport and reactions kinetics. The interplay between highly heterogeneous flow fields found in porous media and microbial behavior, including biofilm growth, results in a spatially heterogeneous biofilm distribution in the porous media as well as internal heterogeneity across the thickness of the biofilm. Our study leverages highly resolved three-dimensional X-ray computed microtomography images of bacterial biofilms in a tubular reactor to numerically compute pore-scale fluid flow and solute transport by considering multiple equivalent stochastically generated internal permeability fields for the biofilm. We show that the internal heterogeneous permeability mainly impacts intermediate velocities when compared with homogeneous biofilm permeability. While the equivalent internal permeability fields of the biofilm do not impact fluid-fluid mixing, they significantly control a fast reaction. For biologically driven reactions such as nutrient or contaminant uptake by the biofilm, its internal permeability field controls the efficiency of the process. This study highlights the importance of considering the internal heterogeneity of biofilms to better predict reactivity in industrial and environmental bioclogged porous systems.}, }
@article {pmid37204124, year = {2023}, author = {Middlemiss, AD and Haycocks, JRJ and Stringer, AM and Piddock, LJV and Wade, JT and Grainger, DC}, title = {Mapping direct and indirect MarA/SoxS/Rob/RamA regulons in Salmonella Typhimurium reveals repression of csgD and biofilm formation.}, journal = {Microbiology (Reading, England)}, volume = {169}, number = {5}, pages = {}, doi = {10.1099/mic.0.001330}, pmid = {37204124}, issn = {1465-2080}, abstract = {The closely related transcription factors MarA, SoxS, Rob and RamA control overlapping stress responses in many enteric bacteria. Furthermore, constitutive expression of such regulators is linked to clinical antibiotic resistance. In this work we have mapped the binding of MarA, SoxS, Rob and RamA across the Salmonella Typhimurium genome. In parallel, we have monitored changes in transcription start site use resulting from expression of the regulators. Together, these data allow direct and indirect gene regulatory effects to be disentangled. Promoter architecture across the regulon can also be deduced. At a phylogenetic scale, around one third of regulatory targets are conserved in most organisms encoding MarA, SoxS, Rob or RamA. We focused our attention on the control of csgD, which encodes a transcriptional activator responsible for stimulating production of curli fibres during biofilm formation. We show that expression of csgD is particularly sensitive to SoxS that binds upstream to repress transcription. This differs to the situation in Escherichia coli, where MarA regulates csgD indirectly.}, }
@article {pmid37202876, year = {2023}, author = {Septama, AW and Chiara, MA and Turnip, G and Tasfiyati, AN and Dewi, RT and Sianipar, EA and Jaisi, A}, title = {Essential Oil of Zingiber cassumunar Roxb. and Zingiber officinale Rosc.: A Comparative Study on Chemical Constituents, Antibacterial Activity, Biofilm Formation, and Inhibition of Pseudomonas aeruginosa Quorum Sensing System.}, journal = {Chemistry &amp; biodiversity}, volume = {}, number = {}, pages = {e202201205}, doi = {10.1002/cbdv.202201205}, pmid = {37202876}, issn = {1612-1880}, abstract = {Pseudomonas aeruginosa can regulate its pathogenicity via quorum sensing (QS) system. Zingiber cassumunar and Z. officinale have been used for the treatment of infectious diseases. The study aimed to evaluate and compare the chemical constituents, antibacterial, and QS inhibitor of Z. cassumunar essential oils (ZCEO) and Z. officinale essential oils (ZOEO). The chemical constituent was analysed using GC-MS. Broth microdilution and spectrophotometry analysis were used to evaluate their antibacterial and QS inhibitor activities. The main constituent of ZOEO with percent composition above 6% (α-curcumene, α-zingiberene, β-sesquiphellandrene, and β-bisabolene, α-citral, and α-farnesene) were exist in a very minimal percentage less than 0.7% in Z. cassumunar. All major components of ZCEO with percentages higher than 5% (terpinen-4-ol, sabinene, γ-terpinene) were present in low proportion (<1.18%) in Z. officinale. ZCEO demonstrated moderate antibacterial activity against P. aeruginosa. The combination of ZCEO and tetracycline showed a synergistic effect (FICI of 0.5). ZCEO exhibited strong activity in inhibiting biofilm formation. ZCEO at ½ MIC (62.5 μg/mL) was able to reduce pyoverdine, pyocyanin, and proteolytic activity. This is the first report on the activity of ZCEO in the inhibition of P. aeruginosa QS system and it may be used to control the pathogenicity of P. aeruginosa.}, }
@article {pmid37202810, year = {2023}, author = {Wang, G and Yin, X and Feng, Z and Chen, C and Chen, D and Wu, B and Liu, C and Morel, JL and Jiang, Y and Yu, H and He, H and Chao, Y and Tang, Y and Qiu, R and Wang, S}, title = {Novel biological aqua crust enhances in situ metal(loid) bioremediation driven by phototrophic/diazotrophic biofilm.}, journal = {Microbiome}, volume = {11}, number = {1}, pages = {110}, pmid = {37202810}, issn = {2049-2618}, abstract = {BACKGROUND: Understanding the ecological and environmental functions of phototrophic biofilms in the biological crust is crucial for improving metal(loid) (e.g. Cd, As) bioremediation in mining ecosystems. In this study, in combination with metal(loid) monitoring and metagenomic analysis, we systematically evaluated the effect of biofilm in a novel biological aqua crust (biogenic aqua crust-BAC) on in situ metal(loid) bioremediation of a representative Pb/Zn tailing pond.<br><br>RESULTS: We observed strong accumulation of potentially bioavailable metal(loid)s and visible phototrophic biofilms in the BAC. Furthermore, dominating taxa Leptolyngbyaceae (10.2-10.4%, Cyanobacteria) and Cytophagales (12.3-22.1%, Bacteroidota) were enriched in biofilm. Along with predominant heterotrophs (e.g. Cytophagales sp.) as well as diazotrophs (e.g. Hyphomonadaceae sp.), autotrophs/diazotrophs (e.g. Leptolyngbyaceae sp.) in phototrophic biofilm enriched the genes encoding extracellular peptidase (e.g. family S9, S1), CAZymes (e.g. CBM50, GT2) and biofilm formation (e.g. OmpR, CRP and LuxS), thus enhancing the capacity of nutrient accumulation and metal(loid) bioremediation in BAC system.<br><br>CONCLUSIONS: Our study demonstrated that a phototrophic/diazotrophic biofilm constitutes the structured communities containing specific autotrophs (e.g. Leptolyngbyaceae sp.) and heterotrophs (e.g. Cytophagales sp.), which effectively control metal(loid) and nutrient input using solar energy in aquatic environments. Elucidation of the mechanisms of biofilm formation coupled with metal(loid) immobilization in BAC expands the fundamental understanding of the geochemical fate of metal(loid)s, which may be harnessed to enhance in situ metal(loid) bioremediation in the aquatic ecosystem of the mining area. Video Abstract.}, }
@article {pmid37202425, year = {2023}, author = {He, L and Lv, H and Wang, Y and Jiang, F and Liu, Q and Zhang, F and Wang, H and Shen, H and Otto, M and Li, M}, title = {Antibiotic treatment can exacerbate biofilm-associated infection by promoting quorum cheater development.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {26}, pmid = {37202425}, issn = {2055-5008}, support = {ZIA AI001080/ImNIH/Intramural NIH HHS/United States ; }, abstract = {Quorum cheating, a socio-microbiological process that is based on mutations in cell density-sensing (quorum-sensing) systems, has emerged as an important contributor to biofilm-associated infection in the leading human pathogen Staphylococcus aureus. This is because inactivation of the staphylococcal Agr quorum-sensing system leads to pronounced biofilm formation, increasing resistance to antibiotics and immune defense mechanisms. Since biofilm infections in the clinic usually progress under antibiotic treatment, we here investigated whether such treatment promotes biofilm infection via the promotion of quorum cheating. Quorum cheater development was stimulated by several antibiotics used in the treatment of staphylococcal biofilm infections more strongly in biofilm than in the planktonic mode of growth. Sub-inhibitory concentrations of levofloxacin and vancomycin were investigated for their impact on biofilm-associated (subcutaneous catheter-associated and prosthetic joint-associated infection), where in contrast to a non-biofilm-associated subcutaneous skin infection model, a significant increase of the bacterial load and development of agr mutants was observed. Our results directly demonstrate the development of Agr dysfunctionality in animal biofilm-associated infection models and reveal that inappropriate antibiotic treatment can be counterproductive for such infections as it promotes quorum cheating and the associated development of biofilms.}, }
@article {pmid37201119, year = {2023}, author = {Fernández-Barat, L and Vázquez Burgos, N and Alcaraz, V and Bueno-Freire, L and López-Aladid, R and Cabrera, R and Gabarrús, A and Palomeque, A and Oscanoa, P and Ceccato, A and Motos, A and Amaro, R and Bernardi, T and Provot, C and Soler-Comas, A and Muñoz, L and Vila, J and Torres, A}, title = {The value of biofilm testing to guide antimicrobial stewardship in chronic respiratory diseases.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1142274}, pmid = {37201119}, issn = {2235-2988}, abstract = {INTRODUCTION: Biofilm production is an important yet currently overlooked aspect of diagnostic microbiology that has implications for antimicrobial stewardship. In this study, we aimed to validate and identify additional applications of the BioFilm Ring Test® (BRT) for Pseudomonas aeruginosa (PA) isolates from patients with bronchiectasis (BE).<br><br>MATERIALS AND METHODS: Sputa were collected from BE patients who had at least one PA positive culture in the previous year. We processed the sputa to isolate both mucoid and non-mucoid PA, and determined their susceptibility pattern, mucA gene status, and presence of ciprofloxacin mutations in QRDR genes. The Biofilm production index (BPI) was obtained at 5 and 24 hours. Biofilms were imaged using Gram staining.<br><br>RESULTS: We collected 69 PA isolates, including 33 mucoid and 36 non-mucoid. A BPI value below 14.75 at 5 hours predicted the mucoid PA phenotype with 64% sensitivity and 72% specificity.<br><br>CONCLUSION: Overall, our findings suggest that the fitness-cost associated with the mucoid phenotype or ciprofloxacin resistance is shown through a time-dependent BPI profile. The BRT has the potential to reveal biofilm features with clinical implications.}, }
@article {pmid37201113, year = {2023}, author = {Takano, T and Kudo, H and Eguchi, S and Matsumoto, A and Oka, K and Yamasaki, Y and Takahashi, M and Koshikawa, T and Takemura, H and Yamagishi, Y and Mikamo, H and Kunishima, H}, title = {Inhibitory effects of vaginal Lactobacilli on Candida albicans growth, hyphal formation, biofilm development, and epithelial cell adhesion.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1113401}, pmid = {37201113}, issn = {2235-2988}, abstract = {INTRODUCTION: Antifungal agents are not always efficient in resolving vulvovaginal candidiasis (VVC), a common genital infection caused by the overgrowth of Candida spp., including Candida albicans, or in preventing recurrent infections. Although lactobacilli (which are dominant microorganisms constituting healthy human vaginal microbiota) are important barriers against VVC, the Lactobacillus metabolite concentration needed to suppress VVC is unknown.<br><br>METHODS: We quantitatively evaluated Lactobacillus metabolite concentrations to determine their effect on Candida spp., including 27 vaginal strains of Lactobacillus crispatus, L. jensenii, L. gasseri, Lacticaseibacillus rhamnosus, and Limosilactobacillus vaginalis, with inhibitory abilities against biofilms of C. albicans clinical isolates.<br><br>RESULTS: Lactobacillus culture supernatants suppressed viable fungi by approximately 24%-92% relative to preformed C. albicans biofilms; however, their suppression differed among strains and not species. A moderate negative correlation was found between Lactobacillus lactate production and biofilm formation, but no correlation was observed between hydrogen peroxide production and biofilm formation. Both lactate and hydrogen peroxide were required to suppress C. albicans planktonic cell growth. Lactobacillus strains that significantly inhibited biofilm formation in culture supernatant also inhibited C. albicans adhesion to epithelial cells in an actual live bacterial adhesion competition test.<br><br>DISCUSSION: Healthy human microflora and their metabolites may play important roles in the development of new antifungal agent against C. albicans-induced VVC.}, }
@article {pmid37199658, year = {2023}, author = {Park, S and Dingemans, J and Sauer, K}, title = {Manganese Acts as an Environmental Inhibitor of Pseudomonas aeruginosa Biofilm Development by Inducing Dispersion and Modulating c-di-GMP and Exopolysaccharide Production via RbdA.}, journal = {Journal of bacteriology}, volume = {}, number = {}, pages = {e0000323}, doi = {10.1128/jb.00003-23}, pmid = {37199658}, issn = {1098-5530}, abstract = {The opportunistic human pathogen Pseudomonas aeruginosa causes chronic infections that involve multicellular aggregates called biofilms. Biofilm formation is modulated by the host environment and the presence of cues and/or signals, likely affecting the pool of the bacterial second messenger cyclic diguanylate monophosphate (c-di-GMP). The manganese ion Mn[2+] is a divalent metal cation that is essential for pathogenic bacterial survival and replication during the infection in a host organism. In this study, we investigated how Mn[2+] alters P. aeruginosa biofilm formation via the regulation of c-di-GMP levels. Exposure to Mn[2+] was found to temporally enhance attachment but impair subsequent biofilm development, apparent by reduced biofilm biomass accumulation and lack of microcolony formation due to the induction of dispersion. Moreover, exposure to Mn[2+] coincided with reduced production of the exopolysaccharides Psl and Pel, decreased transcriptional abundance of pel and psl, and decreased levels of c-di-GMP. To determine whether the effect of Mn[2+] was linked to the activation of phosphodiesterases (PDEs), we screened several PDE mutants for Mn[2+]-dependent phenotypes (attachment and polysaccharide production) as well as PDE activity. The screen revealed that the PDE RbdA is activated by Mn[2+] and is responsible for Mn[2+]-dependent attachment, inhibition of Psl production, and dispersion. Taken together, our findings suggest Mn[2+] is an environmental inhibitor of P. aeruginosa biofilm development that acts through the PDE RbdA to modulate c-di-GMP levels, thereby impeding polysaccharide production and biofilm formation but enhancing dispersion. IMPORTANCE While diverse environmental conditions such as the availability of metal ions have been shown to affect biofilm development, little is known about the mechanism. Here, we demonstrate that Mn[2+] affects Pseudomonas aeruginosa biofilm development by stimulating phosphodiesterase RbdA activity to reduce the signaling molecule c-di-GMP levels, thereby hindering polysaccharide production and biofilm formation but enhancing dispersion. Our findings demonstrate that Mn[2+] acts as an environmental inhibitor of P. aeruginosa biofilms, further suggesting manganese to be a promising new antibiofilm factor.}, }
@article {pmid37197929, year = {2023}, author = {Shin, JY and Kim, MA and Kim, HJ and Neelakantan, P and Yu, MK and Min, KS}, title = {Evaluation of machine-assisted irrigation on removal of intracanal biofilm and extrusion of sodium hypochlorite using a three-dimensionally printed root canal model.}, journal = {Journal of oral science}, volume = {}, number = {}, pages = {}, doi = {10.2334/josnusd.23-0025}, pmid = {37197929}, issn = {1880-4926}, abstract = {PURPOSE: This study aimed to compare the biofilm removal and apical extrusion of sodium hypochlorite (NaOCl) following machine-assisted irrigation using a three-dimensionally (3D) printed dentin-insert model.<br><br>METHODS: Multispecies biofilms were formed in a 3D-printed curved root canal model with dentin insert. The model was then placed in a container that was filled with 0.2% agarose gel containing 0.1% m-Cresol purple. Root canals were irrigated with 1% NaOCl using syringe irrigation, sonically agitated (EndoActivator or EDDY) or ultrasonically activated (Endosonic Blue) irrigation. Samples were photographed and the color-changed area was measured. Biofilm removal was assessed using colony-forming unit counting, confocal laser scanning microscopic analysis and scanning electron microscopic observations. The data were analyzed using one-way ANOVA, followed by Tukey test (P < 0.05).<br><br>RESULTS: EDDY and Endosonic Blue demonstrated significantly greater reduction of biofilms compared to other groups. No significant differences were observed in the remaining biofilm volume in syringe irrigation and EndoActivator groups. Furthermore, EDDY and Endosonic Blue presented with numerous exposed dentinal tubules. EDDY showed significantly greater NaOCl extrusion compared to other groups.<br><br>CONCLUSION: Ultrasonic activation with a small-sized nickel-titanium file irrigation system may be beneficial in intracanal biofilm removal avoiding extrusion of NaOCl beyond the root apex.}, }
@article {pmid37197683, year = {2023}, author = {Lin, X and Yin, H and Wang, L and Chen, Y and Zhao, F and Pu, Y and Tang, X}, title = {Study of a three-dimensional biofilm-electrode reactor (3D-BER) that combined heterotrophic and autotrophic denitrification (HAD) to remove nitrate from water.}, journal = {RSC advances}, volume = {13}, number = {21}, pages = {14675-14684}, pmid = {37197683}, issn = {2046-2069}, abstract = {A three-dimensional biofilm-electrode reactor (3D-BER) that combined heterotrophic and autotrophic denitrification (HAD) was developed to remove nitrate. The denitrification performance of the 3D-BER was evaluated under different experimental conditions, including current intensities (0-80 mA), COD/N ratios (0.5-5), and hydraulic retention times (2-12 h). The results showed that excessive current limited the nitrate removal efficiency. However, a longer hydraulic retention time was not required to achieve a better denitrification effect in the 3D-BER. Moreover, the nitrate could be effectively reduced over a broad range of COD/Ns (1-2.5), and its removal rate peaked at 89% at I = 40 mA, HRT = 8 h, and COD/N = 2. Although the current reduced the diversity of microorganisms in the system, it promoted the growth of dominant species. Nitrification microorganisms were enriched in the reactor, especially Thauera and Hydrogenophaga, which were crucial to the denitrification process. Thus, the combination of autotrophic denitrification and heterotrophic denitrification was promoted by the 3D-BER system to increase the efficiency of nitrogen removal.}, }
@article {pmid37196846, year = {2023}, author = {Kim, SY and Kim, SH and Park, SH}, title = {Inactivation of foodborne pathogen biofilm cells using a combination treatment with gaseous chlorine dioxide and aerosolized sanitizers.}, journal = {Journal of food protection}, volume = {}, number = {}, pages = {100105}, doi = {10.1016/j.jfp.2023.100105}, pmid = {37196846}, issn = {1944-9097}, abstract = {A biofilm is a three-dimensional microbial community, which is difficult to completely control with a typical sanitizer owing to its complex structure. The aim of this study was to establish a system for the combined treatment of biofilms with 10 ppmv gaseous chlorine dioxide (ClO2) and antimicrobial agents (2% citric acid, 2% hydrogen peroxide [H2O2], and 100 ppm peracetic acid [PAA]), and to investigate the synergistic microbicidal efficacy of the combination treatments to inactivate Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7 in biofilms. The antimicrobial agents were aerosolized using a humidifier on top of a chamber to achieve a relative humidity of 90% (within a range of ±2%). While biofilm treatment with the aerosolized antimicrobial agents for 20 min inactivated approximately 1 log CFU/cm[2] (0.72-1.26 log CFU/cm[2]) of the pathogens and the gaseous ClO2 gas treatment for 20 min inactivated <3 log CFU/cm[2] (2.19-2.77 log CFU/cm[2]), combination treatment with citric acid, H2O2, and PAA for 20 min achieved microbial reductions of 2.71-3.79, 4.56-5.12, and 4.45-4.67 log CFU/cm[2] respectively. Our study demonstrates that foodborne pathogens in biofilms can be inactivated by combining gaseous ClO2 treatment with aerosolized antimicrobial agents. The results of this study provide baseline data for the food industry to help control foodborne pathogens in biofilms on inaccessible surfaces.}, }
@article {pmid37196792, year = {2023}, author = {Liang, K and Liu, T and Quan, X}, title = {Simultaneous removal of refractory organic pollutants and nitrogen using electron shuttle suspended biofilm carriers in an integrated hydrolysis/acidification-anoxic/aerobic process.}, journal = {Chemosphere}, volume = {333}, number = {}, pages = {138946}, doi = {10.1016/j.chemosphere.2023.138946}, pmid = {37196792}, issn = {1879-1298}, abstract = {Azo dyes wastewater contains refractory pollutant and nitrogen, which threatens human health and ecological environment when discharged into environment directly. Electron shuttle (ES) is able to participate in the extracellular electron transfer, and thus enhances the removal efficiency of refractory pollutant. However, the continuous dosing of soluble ES would rise operation cost and cause contamination inevitably. In this study, a type of insoluble ES (carbonylated graphene oxide (C-GO)) was developed and melt blended into polyethylene (PE) to prepare novel C-GO-modified suspended carriers. Compared to those of conventional carrier (31.60%), the surface active sites of novel C-GO-modified carrier increased to 52.95%. An integrated hydrolysis/acidification (HA, filled with C-GO-modified carrier) - anoxic/aerobic (AO, filled with clinoptilolite-modified carrier) process was applied to remove azo dye acid red B (ARB) and nitrogen simultaneously. ARB removal efficiency was significantly improved in the reactor filled with C-GO-modified carriers (HA2) compared to the reactor filled with conventional PE carriers (HA1) or activated sludge (HA0). Total nitrogen (TN) removal efficiency of the proposed process increased by 25.95-32.64% compared to the reactor filled with activated sludge. Moreover, the intermediates of ARB were identified by liquid chromatograph-mass spectrometer (LC-MS), and the degradation pathway of ARB through ES was proposed. C-GO-modified carriers induced ARB-removal-related bacterial enrichment (such as Chloroflexi, Lactivibrio, Longilinea, Bacteroidales and Anaerolineaceae). Besides, the relative abundance of denitrifiers and nitrifiers in the AO reactor filled with clinoptilolite-modified carrier was increased by 11.60% compared with activated sludge. Copy numbers of genes related to membrane transport, carbon/energy metabolism and nitrogen metabolism increased significantly on the surface-modified carriers. This study proposed an efficient approach for simultaneous azo dyes and nitrogen removal, showing potential in actual application.}, }
@article {pmid37196686, year = {2023}, author = {Daabash, R and Alqahtani, MQ and Price, RB and Alshabib, A and Niazy, A and Alshaafi, MM}, title = {Surface Properties and Streptococcus mutans Biofilm Adhesion of Ion-Releasing Resin-Based Composite Materials.}, journal = {Journal of dentistry}, volume = {}, number = {}, pages = {104549}, doi = {10.1016/j.jdent.2023.104549}, pmid = {37196686}, issn = {1879-176X}, abstract = {OBJECTIVE: To evaluate the adhesion of Streptococcus mutans (S. mutans) and related surface properties of ion-releasing resin-based composite (RBC) restorative materials.<br><br>METHODS: Two ion-releasing RBCs, Activa (ACT) and Cention-N (CN), were compared to a conventional RBC (Z350) and a resin-modified glass ionomer cement (Fuji-II-LC). Ten disk-shaped specimens were fabricated for each material (n=40). After standardized surface polishing procedure, the surface properties of the specimens were evaluated using surface roughness measurements by a profilometer and hydrophobicity using water contact angle measurements. To assess bacterial adhesion, the number of S. mutans bacteria was calculated from colony-forming units (CFU). Confocal laser scanning microscope analysis was done for qualitative &amp; quantitative assessment. The data were analyzed using One-way ANOVA followed by Tukey's post-hoc test to compare the mean values of surface roughness, water contact angle and CFU values. To compare the mean dead cell percentage Kruskal-Wallis rank test and Conover test were used. A p-value of &#x2264; 0.05 was used to report the statistical significance.<br><br>RESULTS: Z350 and ACT had the smoothest surfaces, followed by CN, and the roughest surface was seen in FUJI-II-LC. The lowest water contact angles were seen in CN, and Z350, and the highest were in ACT. S. mutans counts were the highest in ACT and the lowest in Z350 and CN. CN and Fuji-II-LC registered the highest percentage of dead bacterial cells, while the lowest were in ACT.<br><br>SIGNIFICANCE: Surface properties did not significantly influence bacterial adhesion. More S. mutans bacteria accumulated on ACT than on the nanofilled composite and on CN. CN had antibacterial effects against Streptococcus mutans biofilms.}, }
@article {pmid37196464, year = {2023}, author = {Wang, J and Wu, J and Li, J and Kong, R and Li, X and Wang, X}, title = {Simulation of various biofilm fractal morphologies by agent-based model.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {227}, number = {}, pages = {113352}, doi = {10.1016/j.colsurfb.2023.113352}, pmid = {37196464}, issn = {1873-4367}, abstract = {Biofilms are clusters of bacteria wrapped in extracellular matrix and polymers. The study of biofilm morphological transformation has been around for a long time and has attracted widespread attention. In this paper, we present a model for biofilm growth based on the interaction force, in which bacteria are treated as tiny particles and locations of particles are updated by calculating the repulsive forces among particles. We adapt a continuity equation to indicate nutrient concentration variation in the substrate. Based on the above, we study the morphological transformation of biofilms. We find that nutrient concentration and nutrient diffusion rate dominate different biofilm morphological transition processes, in which biofilms would grow into fractal morphology under the conditions of low nutrient concentration and nutrient diffusivity. At the same time, we expand our model by introducing a second particle to mimic extracellular polymeric substances (EPS) in biofilms. We find that the interaction between different particles can lead to phase separation patterns between cells and EPSs, and the adhesion effect of EPS can attenuate this phenomenon. In contrast to single particle system models, branches are inhibited due to EPS filling in dual particle system models, and this invalidation is boosted by the enhancement of the depletion effect.}, }
@article {pmid37196462, year = {2023}, author = {Xu, LC and Ochetto, A and Chen, C and Sun, D and Allcock, HR and Siedlecki, CA}, title = {Surfaces modified with small molecules that interfere with nucleotide signaling reduce Staphylococcus epidermidis biofilm and increase the efficacy of ciprofloxacin.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {227}, number = {}, pages = {113345}, doi = {10.1016/j.colsurfb.2023.113345}, pmid = {37196462}, issn = {1873-4367}, abstract = {Staphylococcus epidermidis are common bacteria associated with biofilm related infections on implanted medical devices. Antibiotics are often used in combating such infections, but they may lose their efficacy in the presence of biofilms. Bacterial intracellular nucleotide second messenger signaling plays an important role in biofilm formation, and interference with the nucleotide signaling pathways provides a possible way to control biofilm formation and to increase biofilm susceptibility to antibiotic therapy. This study synthesized small molecule derivates of 4-arylazo-3,5-diamino-1 H-pyrazole (named as SP02 and SP03) and found these molecules inhibited S. epidermidis biofilm formation and induced biofilm dispersal. Analysis of bacterial nucleotide signaling molecules showed that both SP02 and SP03 significantly reduced cyclic dimeric adenosine monophosphate (c-di-AMP) levels in S. epidermidis at doses as low as 25 µM while having significant effects on multiple nucleotides signaling including cyclic dimeric guanosine monophosphate (c-di-GMP), c-di-AMP, and cyclic adenosine monophosphate (cAMP) at high doses (100 µM or greater). We then tethered these small molecules to polyurethane (PU) biomaterial surfaces and investigated biofilm formation on the modified surfaces. Results showed that the modified surfaces significantly inhibited biofilm formation during 24 h and 7-day incubations. The antibiotic ciprofloxacin was used to treat these biofilms and the efficacy of the antibiotic (2 µg/mL) was found to increase from 94.8% on unmodified PU surfaces to > 99.9% on both SP02 and SP03 modified surfaces (>3 log units). Results demonstrated the feasibility of tethering small molecules that interfere with nucleotide signaling onto polymeric biomaterial surfaces and in a way that interrupts biofilm formation and increases antibiotic efficacy for S. epidermidis infections.}, }
@article {pmid37196354, year = {2023}, author = {Wang, H and Fu, Y and Du, S and Liu, P and Ren, J and Liu, Y and Tao, J and Zhang, L and Zhu, J}, title = {Mechanically Robust Dissolving Microneedles Made of Supramolecular Photosensitizers for Effective Photodynamic Bacterial Biofilm Elimination.}, journal = {ACS applied materials &amp; interfaces}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsami.3c03614}, pmid = {37196354}, issn = {1944-8252}, abstract = {Bacterial biofilms pose severe threats to public health worldwide and are intractable by conventional antibiotic treatment. Antimicrobial photodynamic therapy (PDT) is emerging as a promising strategy for eradicating biofilms by virtue of low invasiveness, broad-spectrum antibacterial activity, and nondrug resistance. However, its practical efficacy is impeded by the low water solubility, severe aggregation, and poor penetration of photosensitizers (PSs) into the dense extracellular polymeric substances (EPS) of biofilms. Herein, we develop a dissolving microneedle (DMN) patch composed of a sulfobutylether-β-cyclodextrin (SCD)/tetra(4-pyridyl)-porphine (TPyP) supramolecular PS for enhanced biofilm penetration and eradication. The inclusion of TPyP into the SCD cavity can drastically inhibit the aggregation of TPyP, thereby allowing for nearly tenfold reactive oxygen species production and high photodynamic antibacterial efficacy. Moreover, the TPyP/SCD-based DMN (TSMN) possesses excellent mechanical performance that can easily pierce the EPS of biofilm with a penetration depth of ∼350 μm, enabling sufficient contact of TPyP with bacteria and optimal photodynamic elimination of bacterial biofilms. Furthermore, TSMN could efficiently eradicate Staphylococcus aureus biofilm infection in vivo with good biosafety. This study offers a promising platform for supramolecular DMN for efficient biofilm elimination and other PDTs.}, }
@article {pmid37196016, year = {2023}, author = {Alvarado, M and Gómez-Navajas, JA and Blázquez-Muñoz, MT and Gómez-Molero, E and Berbegal, C and Eraso, E and Kramer, G and De Groot, PWJ}, title = {Integrated post-genomic cell wall analysis reveals floating biofilm formation associated with high expression of flocculins in the pathogen Pichia kudriavzevii.}, journal = {PLoS pathogens}, volume = {19}, number = {5}, pages = {e1011158}, doi = {10.1371/journal.ppat.1011158}, pmid = {37196016}, issn = {1553-7374}, abstract = {The pathogenic yeast Pichia kudriavzevii, previously known as Candida krusei, is more distantly related to Candida albicans than clinically relevant CTG-clade Candida species. Its cell wall, a dynamic organelle that is the first point of interaction between pathogen and host, is relatively understudied, and its wall proteome remains unidentified to date. Here, we present an integrated study of the cell wall in P. kudriavzevii. Our comparative genomic studies and experimental data indicate that the general structure of the cell wall in P. kudriavzevii is similar to Saccharomyces cerevisiae and C. albicans and is comprised of β-1,3-glucan, β-1,6-glucan, chitin, and mannoproteins. However, some pronounced differences with C. albicans walls were observed, for instance, higher mannan and protein levels and altered protein mannosylation patterns. Further, despite absence of proteins with high sequence similarity to Candida adhesins, protein structure modeling identified eleven proteins related to flocculins/adhesins in S. cerevisiae or C. albicans. To obtain a proteomic comparison of biofilm and planktonic cells, P. kudriavzevii cells were grown to exponential phase and in static 24-h cultures. Interestingly, the 24-h static cultures of P. kudriavzevii yielded formation of floating biofilm (flor) rather than adherence to polystyrene at the bottom. The proteomic analysis of both conditions identified a total of 33 cell wall proteins. In line with a possible role in flor formation, increased abundance of flocculins, in particular Flo110, was observed in the floating biofilm compared to exponential cells. This study is the first to provide a detailed description of the cell wall in P. kudriavzevii including its cell wall proteome, and paves the way for further investigations on the importance of flor formation and flocculins in the pathogenesis of P. kudriavzevii.}, }
@article {pmid37195208, year = {2023}, author = {Howard, MK and Miller, KR and Sohn, BS and Ryan, JJ and Xu, A and Jackrel, ME}, title = {Probing the drivers of Staphylococcus aureus biofilm protein amyloidogenesis and disrupting biofilms with engineered protein disaggregases.}, journal = {mBio}, volume = {}, number = {}, pages = {e0058723}, doi = {10.1128/mbio.00587-23}, pmid = {37195208}, issn = {2150-7511}, abstract = {Phenol-soluble modulins (PSMs) are the primary proteinaceous component of Staphylococcus aureus biofilms. Residence in the protective environment of biofilms allows bacteria to rapidly evolve and acquire antimicrobial resistance, which can lead to persistent infections such as those caused by methicillin-resistant S. aureus (MRSA). In their soluble form, PSMs hinder the immune response of the host and can increase the virulence potential of MRSA. PSMs also self-assemble into insoluble functional amyloids that contribute to the structural scaffold of biofilms. The specific roles of PSM peptides in biofilms remain poorly understood. Here, we report the development of a genetically tractable yeast model system for studying the properties of PSMα peptides. Expression of PSMα peptides in yeast drives the formation of toxic insoluble aggregates that adopt vesicle-like structures. Using this system, we probed the molecular drivers of PSMα aggregation to delineate key similarities and differences among the PSMs and identified a crucial residue that drives PSM features. Biofilms are a major public health threat; thus, biofilm disruption is a key goal. To solubilize aggregates comprised of a diverse range of amyloid and amyloid-like species, we have developed engineered variants of Hsp104, a hexameric AAA+ protein disaggregase from yeast. Here, we demonstrate that potentiated Hsp104 variants counter the toxicity and aggregation of PSMα peptides. Further, we demonstrate that a potentiated Hsp104 variant can drive the disassembly of preformed S. aureus biofilms. We suggest that this new yeast model can be a powerful platform for screening for agents that disrupt PSM aggregation and that Hsp104 disaggregases could be a promising tool for the safe enzymatic disruption of biofilms.}, }
@article {pmid37195016, year = {2023}, author = {Visser, JA and Yager, D and Chambers, SA and Lim, JY and Cao, X and Cegelski, L}, title = {Nordihydroguaiaretic Acid (NDGA) Inhibits CsgA Polymerization, Bacterial Amyloid Biogenesis, and Biofilm Formation.}, journal = {Chembiochem : a European journal of chemical biology}, volume = {}, number = {}, pages = {e202300266}, doi = {10.1002/cbic.202300266}, pmid = {37195016}, issn = {1439-7633}, abstract = {Escherichia coli and other Enterobacteriaceae thrive in robust biofilm communities through the coproduction of curli amyloid fibers and phosphoethanolamine cellulose. Curli promote adhesion to abiotic surfaces and plant and human host tissues and are associated with pathogenesis in urinary tract infection and foodborne illness. As amyloid, curli production in the host has also been implicated in the pathogenesis of neurodegenerative diseases. We report that the natural product nordihydroguaiaretic acid (NDGA) is effective as a curlicide in E. coli. NDGA prevents CsgA polymerization in vitro in a dose-dependent manner. NDGA selectively inhibits cellassociated curli assembly in E. coli and inhibits biofilm formation among uropathogenic E. coli in a curli-specific manner. More broadly, our work emphasizes the ability to evaluate and identify bioactive amyloid assembly inhibitors using the powerful gene-directed amyloid biogenesis machinery in E. coli.}, }
@article {pmid37193875, year = {2023}, author = {Wang, Y and Liu, H and Geng, F and Yang, P and Lü, J and Li, X}, title = {Label-free analysis of biofilm phenotypes by infrared micro- and correlation spectroscopy.}, journal = {Analytical and bioanalytical chemistry}, volume = {}, number = {}, pages = {}, pmid = {37193875}, issn = {1618-2650}, abstract = {The methodology development for deeply describing the complex biofilm phenotypes is an urgent demand for understanding their basic biology and the central clinic relevance. Here, we developed an infrared microspectroscopy-based method for the quantitative evaluation and description of biofilm phenotypic characteristics by calculating the spectral similarity of the infrared data. Using this approach, we revealed the phenotypic variation during the biofilm formation process and biofilm heterogeneity between two E. coli strains. Two-dimensional correlation spectroscopy was further combined to deeply investigate the biochemical component evolution sequences during E. coli biofilm formation and revealed the first-order of the polysaccharide molecules change, expanding new opportunities for infrared microspectroscopy in revealing molecule evolution in the biofilm formation. This novel development offers a label-free optical toolkit for the bioanalytical analysis of biofilm phenotypes but also paves the way for screening the drugs to modulate the structure and ecology of biofilm microbiome.}, }
@article {pmid37193303, year = {2023}, author = {Mao, Y and Liu, P and Chen, H and Wang, Y and Li, C and Wang, Q}, title = {Baicalein Inhibits the Staphylococcus aureus Biofilm and the LuxS/AI-2 System in vitro.}, journal = {Infection and drug resistance}, volume = {16}, number = {}, pages = {2861-2882}, pmid = {37193303}, issn = {1178-6973}, abstract = {INTRODUCTION: Staphylococcus aureus (S. aureus) is a common cause of mastitis in dairy cows, a condition that has a significant economic impact. S. aureus displays quorum sensing (QS) system-controlled virulence characteristics, like biofilm formation, that make therapy challenging. In order to effectively combat S. aureus, one potential technique is to interfere with quorum sensing.<br><br>METHODS: This study evaluated the effects of different Baicalin (BAI) concentrations on the growth and the biofilm of S. aureus isolates, including the biofilm formation and mature biofilm clearance. The binding activity of BAI to LuxS was verified by molecular docking and kinetic simulations. The secondary structure of LuxS in the formulations was characterized using fluorescence quenching and Fourier transform infrared (FTIR) spectroscopy. Additionally, using fluorescence quantitative PCR, the impact of BAI on the transcript levels of the luxS and biofilm-related genes was investigated. The impact of BAI on LuxS at the level of protein expression was also confirmed by a Western blotting investigation.<br><br>RESULTS: According to the docking experiments, they were able to engage with the amino acid residues in LuxS and BAI through hydrogen bonding. The results of molecular dynamics simulations and the binding free energy also confirmed the stability of the complex and supported the experimental results. BAI&#xa0;showed&#xa0;weak inhibitory activity against S. aureus but significantly reduced biofilm formation and disrupted mature biofilms. BAI also downregulated luxS and biofilm-associated genes' mRNA expression. Successful binding was confirmed using fluorescence quenching and FTIR.<br><br>DISCUSSION: We thus report that BAI inhibits the S. aureus LuxS/AI-2 system for the first time, which raises the possibility that BAI could be employed as a possible antimicrobial drug to treat S. aureus strain-caused biofilms.}, }
@article {pmid37192897, year = {2023}, author = {Xia, F and Tao, X and Wang, H and Shui, J and Min, C and Xia, Y and Li, J and Tang, M and Liu, Z and Hu, Y and Luo, H and Zou, M}, title = {Biosynthesis of Silver Nanoparticles Using the Biofilm Supernatant of Pseudomonas aeruginosa PA75 and Evaluation of Their Antibacterial, Antibiofilm, and Antitumor Activities.}, journal = {International journal of nanomedicine}, volume = {18}, number = {}, pages = {2485-2502}, pmid = {37192897}, issn = {1178-2013}, abstract = {PURPOSE: As an under-explored biomaterial, bacterial biofilms have a wide range of applications in the green synthesis of nanomaterials. The biofilm supernatant of Pseudomonas aeruginosa PA75 was used to synthesize novel silver nanoparticles (AgNPs). BF75-AgNPs were found to possess several biological properties.<br><br>METHODS: In this study, we biosynthesized BF75-AgNPs using biofilm supernatant as the reducing agent, stabilizer, and dispersant and investigated their biopotential in terms of antibacterial, antibiofilm, and antitumor activities.<br><br>RESULTS: The synthesized BF75-AgNPs demonstrated a typical face-centered cubic crystal structure; they were well dispersed; and they were spherical with a size of 13.899 &#xb1; 4.036 nm. The average zeta potential of the BF75-AgNPs was -31.0 &#xb1; 8.1 mV. The BF75-AgNPs exhibited strong antibacterial activities against the methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase Escherichia coli (ESBL-EC), extensively drug-resistant Klebsiella pneumoniae (XDR-KP), and carbapenem-resistant Pseudomonas aeruginosa (CR-PA). Moreover, the BF75-AgNPs had a strong bactericidal effect on XDR-KP at 1/2 &#xd7; MIC, and the expression level of reactive oxygen species (ROS) in bacteria was significantly increased. A synergistic effect was observed when the BF75-AgNPs and colistin were used for the co-treatment of two colistin-resistant XDR-KP strains, with fractional inhibitory concentration index (FICI) values of 0.281 and 0.187, respectively. Furthermore, the BF75-AgNPs demonstrated a strong biofilm inhibition activity and mature biofilm bactericidal activity against XDR-KP. The BF75-AgNPs also exhibited a strong antitumor activity against melanoma cells and low cytotoxicity against normal epidermal cells. In addition, the BF75-AgNPs increased the proportion of apoptotic cells in two melanoma cell lines, and the proportion of late apoptotic cells increased with BF75-AgNP concentration.<br><br>CONCLUSION: This study suggests that BF75-AgNPs synthesized from biofilm supernatant have broad prospects for antibacterial, antibiofilm, and antitumor applications.}, }
@article {pmid37192894, year = {2023}, author = {Tong, F and Wang, P and Chen, Z and Liu, Y and Wang, L and Guo, J and Li, Z and Cai, H and Wei, J}, title = {Combined Ferromagnetic Nanoparticles for Effective Periodontal Biofilm Eradication in Rat Model.}, journal = {International journal of nanomedicine}, volume = {18}, number = {}, pages = {2371-2388}, pmid = {37192894}, issn = {1178-2013}, abstract = {INTRODUCTION: The critical challenge for periodontitis therapy is thoroughly eliminating the dental plaque biofilm, particularly penetrating the deep periodontal tissue. Regular therapeutic strategies are insufficient to penetrate the plaque without disturbing the commensal microflora of the oral cavity. Here, we constructed a Fe3O4 magnetic nanoparticle loading minocycline (FPM NPs) to penetrate the biofilm physically and effectively eliminate periodontal biofilm.<br><br>METHODS: In order to penetrate and remove the biofilm effectively, Fe3O4 magnetic nanoparticles were modified with minocycline using a co-precipitation method. The particle size and dispersion of the nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. The antibacterial effects were examined to verify the magnetic targeting of FPM NPs. Confocal laser scanning microscopy was employed to check the effect of FPM + MF and develop the best FPM NPs treatment strategy. Additionally, the therapeutic effect of FPM NPs was investigated in periodontitis rat models. The expression of IL-1&#x3b2;, IL-6, and TNF-&#x3b1; in periodontal tissues was measured by qRT-PCR and Western blot.<br><br>RESULTS: The multifunctional nanoparticles exhibited intense anti-biofilm activity and good biocompatibility. The magnetic forces could pull FMP NPs against the biofilm mass and kill bacteria deep in the biofilms both in vivo and in vitro. The integrity of the bacterial biofilm is disrupted under the motivation of the magnetic field, allowing for improved drug penetration and antibacterial performance. The periodontal inflammation recovered well after FPM NPs treatment in rat models. Furthermore, FPM NPs could be monitored in real-time and have magnetic targeting potentials.<br><br>CONCLUSION: FPM NPs exhibit good chemical stability and biocompatibility. The novel nanoparticle presents a new approach for treating periodontitis and provides experimental support for using magnetic-targeted nanoparticles in clinic applications.}, }
@article {pmid37191582, year = {2023}, author = {Nassar, R and Nassar, M and Senok, A and Williams, D}, title = {Phytic Acid Demonstrates Rapid Antibiofilm Activity and Inhibits Biofilm Formation When Used as a Surface Conditioning Agent.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0026723}, doi = {10.1128/spectrum.00267-23}, pmid = {37191582}, issn = {2165-0497}, abstract = {Root canal infections are associated with biofilms and are treated with chemical irrigants with a high success rate. However, treatment failure does arise, which is attributed primarily to resistance exhibited by biofilms. Currently used irrigants in root canal treatment have disadvantages, and there is therefore a need for more biocompatible alternatives with antibiofilm properties to reduce root canal treatment failure and complications. The aim of this study was to evaluate the in vitro antibiofilm properties of phytic acid (IP6), which is a potential alternative treatment agent. Single- and dual-species biofilms of Enterococcus faecalis and Candida albicans were developed on the well surfaces of 12-well plates and on hydroxyapatite (HA) coupons, and then exposed to IP6. In addition, selected HA coupons were preconditioned with IP6 before biofilm development. IP6 demonstrated bactericidal effects and altered the metabolic activity of biofilm cells. Confocal laser-scanning microscopy showed that IP6 caused significant and rapid reduction in live biofilm cells. At sublethal concentrations, IP6 did not alter the expression of tested virulence genes except for C. albicans hwp1, the expression of which was upregulated but not reflected by a change in hyphal transformation. IP6-preconditioned HA coupons led to extensive inhibition of dual-species biofilm formation. The results of this study highlight for the first time the antibiofilm inhibitory properties of IP6 and the potential for its exploitation in several clinical applications. IMPORTANCE Root canal infections are biofilm associated, and despite mechanical and chemical treatment procedures, infection recurrence occurs, and this is likely due to the high tolerance of associated biofilms to antimicrobials. The currently used treatment agents have several disadvantages, which necessitates the search for new improved agents. In this study, the natural chemical phytic acid was found to exhibit antibiofilm activity against established mono and dual mature biofilms over a short contact time. Most importantly, phytic acid was found to cause significant inhibition of dual-species biofilm formation when used as a surface preconditioning agent. The findings of this study identified a novel use of phytic acid as a potential antibiofilm agent that can be used in several clinical applications.}, }
@article {pmid37191545, year = {2023}, author = {Silva-Rohwer, AR and Held, K and Yakhnin, H and Babitzke, P and Vadyvaloo, V}, title = {CsrA-Mediated Translational Activation of the hmsE mRNA Enhances HmsD-Dependent C-di-GMP-Enabled Biofilm Production in Yersinia pestis.}, journal = {Journal of bacteriology}, volume = {}, number = {}, pages = {e0010523}, doi = {10.1128/jb.00105-23}, pmid = {37191545}, issn = {1098-5530}, abstract = {The plague bacterium, Yersinia pestis, forms a biofilm-mediated blockage in the flea foregut that enhances its transmission by fleabite. Biofilm formation is positively controlled by cyclic di-GMP (c-di-GMP), which is synthesized by the diguanylate cyclases (DGC), HmsD and HmsT. While HmsD primarily promotes biofilm-mediated blockage of fleas, HmsT plays a more minor role in this process. HmsD is a component of the HmsCDE tripartite signaling system. HmsC and HmsE posttranslationally inhibit or activate HmsD, respectively. HmsT-dependent c-di-GMP levels and biofilm formation are positively regulated by the RNA-binding protein CsrA. In this study we determined whether CsrA positively regulates HmsD-dependent biofilm formation through interactions with the hmsE mRNA. Gel mobility shift assays determined that CsrA binds specifically to the hmsE transcript. RNase T1 footprint assays identified a single CsrA binding site and CsrA-induced structural changes in the hmsE leader region. Translational activation of the hmsE mRNA was confirmed in vivo using plasmid-encoded inducible translational fusion reporters and by HmsE protein expression studies. Furthermore, mutation of the CsrA binding site in the hmsE transcript significantly reduced HmsD-dependent biofilm formation. These results suggest that CsrA binding leads to structural changes in the hmsE mRNA that enhance its translation to enable increased HmsD-dependent biofilm formation. Given the requisite function of HmsD in biofilm-mediated flea blockage, this CsrA-dependent increase in HmsD activity underscores that complex and conditionally defined modulation of c-di-GMP synthesis within the flea gut is required for Y. pestis transmission. IMPORTANCE Mutations enhancing c-di-GMP biosynthesis drove the evolution of Y. pestis to flea-borne transmissibility. c-di-GMP-dependent biofilm-mediated blockage of the flea foregut enables regurgitative transmission of Y. pestis by fleabite. The Y. pestis diguanylate cyclases (DGC), HmsT and HmsD, which synthesize c-di-GMP, play significant roles in transmission. Several regulatory proteins involved in environmental sensing, as well as signal transduction and response regulation, tightly control DGC function. An example is CsrA, a global posttranscriptional regulator that modulates carbon metabolism and biofilm formation. CsrA integrates alternative carbon usage metabolism cues to activate c-di-GMP biosynthesis through HmsT. Here, we demonstrated that CsrA additionally activates hmsE translation to promote c-di-GMP biosynthesis through HmsD. This emphasizes that a highly evolved regulatory network controls c-di-GMP synthesis and Y. pestis transmission.}, }
@article {pmid37191458, year = {2023}, author = {Shaghayegh, G and Cooksley, C and Bouras, G and Nepal, R and Houtak, G and Panchatcharam, BS and Fenix, KA and Psaltis, AJ and Wormald, PJ and Vreugde, S}, title = {Staphylococcus aureus biofilm properties and chronic rhinosinusitis severity scores correlate positively with total CD4+ T-cell frequencies and inversely with its Th1, Th17 and regulatory cell frequencies.}, journal = {Immunology}, volume = {}, number = {}, pages = {}, doi = {10.1111/imm.13655}, pmid = {37191458}, issn = {1365-2567}, abstract = {Chronic rhinosinusitis (CRS) represents chronic inflammation of the sinus mucosa characterised by dysfunction of the sinuses' natural defence mechanisms and induction of different inflammatory pathways ranging from a Th1 to a Th2 predominant polarisation. Recalcitrant CRS is associated with Staphylococcus aureus dominant mucosal biofilms; however, S. aureus colonisation of the sinonasal mucosa has also been observed in healthy individuals challenging the significance of S. aureus in CRS pathogenesis. We aimed to investigate the relationship between CRS key inflammatory markers, S. aureus biofilm properties/virulence genes and the severity of the disease. Tissue samples were collected during endoscopic sinus surgery from the ethmoid sinuses of CRS patients with (CRSwNP) and without (CRSsNP) nasal polyps and controls (n = 59). CD3+ T-cell subset frequencies and key inflammatory markers of CD4+ helper T cells were determined using FACS analysis. Sinonasal S. aureus clinical isolates were isolated (n = 26), sequenced and grown into biofilm in vitro, followed by determining their properties, including metabolic activity, biomass, colony-forming units and exoprotein production. Disease severity was assessed using Lund-Mackay radiologic scores, Lund-Kennedy endoscopic scores and SNOT22 quality of life scores. Our results showed that S. aureus biofilm properties and CRS severity scores correlated positively with total CD4+ T-cell frequencies but looking into CD4+ T-cell subsets showed an inverse correlation with Th1 and Th17 cell frequencies. CD4+ T-cell frequencies were higher in patients harbouring lukF.PV-positive S. aureus while its regulatory and Th17 cell subset frequencies were lower in patients carrying sea- and sarT/U-positive S. aureus. Recalcitrant CRS is characterised by increased S. aureus biofilm properties in relation to increased total CD4+ helper T-cell frequencies and reduced frequencies of its Th1, Th17 and regulatory T-cell subsets. These findings offer insights into the pathophysiology of CRS and could lead to the development of more targeted therapies.}, }
@article {pmid37190965, year = {2023}, author = {Luan, Y and Wang, Y and Liu, C and Lv, L and Xu, A and Song, Z}, title = {Effects of potassium monopersulfate on nitrification activity and bacterial community structure of sponge biocarrier biofilm in Litopenaeus vannamei aquaculture system.}, journal = {Environmental technology}, volume = {}, number = {}, pages = {1-22}, doi = {10.1080/09593330.2023.2215455}, pmid = {37190965}, issn = {1479-487X}, abstract = {Effects of potassium monopersulfate (KMPS) on the nitrification activity, aquacultural water quality and bacterial community structure of sponge biocarriers with pre-cultured biofilm (SBBF) were analysed through shaking flask experiments and L. vannamei aquaculture experiments. Changes in the ammonia oxidation rate (AOR) and nitrite oxidation rate (NOR) of SBBF under six KMPS concentration treatments (0 mg/L, 1 mg/L, 2 mg/L, 3 mg/L, 4 mg/L and 5 mg/L) were studied. The results showed that the AOR and NOR of SBBF treated with high concentrations of KMPS (3 mg/L, 4 mg/L and 5 mg/L) were significantly lower than those of the control group (CK) (p < 0.05). However, compared with the first dosing of NH4Cl and NaNO2, the inhibition of AOR and NOR by KMPS on AOR and NOR was weakened after the second and third dosing times. That is, AOR and NOR can recover partially or completely over time. The L. vannamei aquaculture experiment was performed using four concentrations of KMPS (0 mg/L, 2 mg/L, 4 mg/L and 8 mg/L). The results showed that with increasing KMPS dosage, the average and peak concentrations of NH4[+]-N and NO2[-]-N in each treatment significantly increased (P <0.05), and the final body weight of shrimp significantly decreased (P <0.05). Furthermore the highest dose (8.0 mg/L) of KMPS reduced the survival rate by 9.33% compared to the CK. High-throughput sequencing analysis of the biofilm structure showed that the relative abundances of Nitrospirota, Nitrosomonas and Nitrococcus, which are related to nitrogen cycling, and beneficial bacteria including Firmicutes and Bacilli decreased with the addition of KMPS (p<0.05).}, }
@article {pmid37189223, year = {2023}, author = {Sun, H and Si, F and Zhao, X and Li, F and Qi, G}, title = {The cellular redox state in Bacillus amyloliquefaciens WH1 affects biofilm formation indirectly in a surfactant direct manner.}, journal = {Journal of basic microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1002/jobm.202300064}, pmid = {37189223}, issn = {1521-4028}, abstract = {Surfactin is a signal to trigger biofilm formation against harsh environments. Generally, harsh environments can result in change of the cellular redox state to induce biofilm formation, but we know little about whether the cellular redox state influences biofilm formation via surfactin. Here, the reductant glucose could reduce surfactin and enhance biofilm formation by a surfactin-indirect way. The oxidant H2 O2 led to a decrease of surfactin accompanying with weakened biofilm formation. Spx and PerR were both necessary for surfactin production and biofilm formation. H2 O2 improved surfactin production but inhibited biofilm formation by a surfactin-indirect manner in Δspx, while it reduced surfactin production without obvious influence on biofilm formation in ΔperR. The ability against H2 O2 stress was enhanced in Δspx, but weakened in ΔperR. Thereby, PerR was favorable for resisting oxidative stress, while Spx played a negative role in this action. Knockout and compensation of rex also supported that the cells could form biofilm by a surfactin-indirect way. Collectively, surfactin is not a unique signal to trigger biofilm formation, and the cellular redox state can influence biofilm formation by a surfactin-direct or -indirect way in Bacillus amyloliquefaciens WH1.}, }
@article {pmid37189214, year = {2023}, author = {Harpke, M and Kothe, E}, title = {Biofilm formation in Gram-positives as an answer to combined salt and metal stress.}, journal = {Journal of basic microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1002/jobm.202300149}, pmid = {37189214}, issn = {1521-4028}, abstract = {Biofilm formation can lead to tolerance against stressors like antibiotics, toxic metals, salts, and other environmental contaminants. Halo- and metal-tolerant bacilli and actinomycete strains isolated from a former uranium mining and milling site in Germany were shown to form biofilm in response to salt and metal treatment; specifically, Cs and Sr exposition led to biofilm formation. Since the strains were obtained from soil samples, a more structured environment was tested using expanded clay to provide porous structures resembling the natural environment. There, accumulation of Cs could be shown for Bacillus sp. SB53B, and high Sr accumulation ranging from 75% to 90% was seen with all isolates tested. We could, therefore, show that biofilms in a structured environment like soil will contribute to the water purification obtained by the passage of water through the critical zone of soil, providing an ecosystem benefit that can hardly be overestimated.}, }
@article {pmid37188866, year = {2023}, author = {Islam, OK and Islam, I and Saha, O and Rahaman, MM and Sultana, M and Bockmühl, DP and Hossain, MA}, title = {Genomic variability correlates with biofilm phenotypes in multidrug resistant clinical isolates of Pseudomonas aeruginosa.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {7867}, pmid = {37188866}, issn = {2045-2322}, abstract = {The multifactorial nature of Pseudomonas aeruginosa biofilm development and genomic variabilities implicates its resistance to conventional antimicrobials and virulence. Therefore, genetic determinants need to be extensively studied to block the early steps of biofilm or already formed biofilms. In this study, a total of 20 multidrug resistant (MDR) clinical P. aeruginosa isolates were evaluated for their biofilm forming abilities and related genes. Of the isolates tested, all of them showed surface attachment tendencies in nutrient limiting conditions, and classified as strong (SBF = 45%), moderate (MBF = 30%) and weak (WBF = 25%) biofilm formers. Complete genome sequencing of representative strong (DMC-27b), moderate (DMC-20c) and weak biofilm former (DMC-30b) isolates was performed. Analysis of biofilm related genes in the sequenced genomes revealed that, 80 of the 88 biofilm related genes possess 98-100% sequence identity to the reference PAO1 strain. Complete and partial sequence data of LecB proteins from tested isolates indicate that isolates containing PA14-like LecB sequences produced strong biofilms. All of the 7 pel operon protein coding genes in weak biofilm former isolate 30b showed significant nucleotide sequence variation with other tested isolates, and their corresponding proteins are 99% identical with the pel operon proteins of PA7. Bioinformatics analyses identified divergent sequence and structural features that separate PA7 like pel operon proteins from reference PAO1-like pel operon. Congo red and pellicle forming assays revealed that the sequence and structure variations may have interfered with the Pel production pathway and resulted in impaired Pel production in isolate 30b that has a PA7 like pel operon. Expression analysis also showed that both pelB and lecB genes were about 5 to 6 folds upregulated after 24 h in SBF 27b in comparison with WBF 30b. Our findings indicate significant genomic divergence in biofilm related genes of P. aeruginosa strains that affect their biofilm phenotypes.}, }
@article {pmid37187675, year = {2023}, author = {Parga, A and Manoil, D and Brundin, M and Otero, A and Belibasakis, GN}, title = {Gram-negative quorum sensing signalling enhances biofilm formation and virulence traits in gram-positive pathogen Enterococcus faecalis.}, journal = {Journal of oral microbiology}, volume = {15}, number = {1}, pages = {2208901}, pmid = {37187675}, issn = {2000-2297}, abstract = {Acyl-homoserine lactones (AHLs) are typical quorum-sensing molecules of gram-negative bacteria. Recent evidence suggests that AHLs may also affect gram-positives, although knowledge of these interactions remains scarce. Here, we assessed the effect of AHLs on biofilm formation and transcriptional regulations in the gram-positive Enterococcus faecalis. Five E. faecalis strains were investigated herein. Crystal violet was employed to quantify the biomass formed, and confocal microscopy in combination with SYTO9/PI allowed the visualisation of biofilms' structure. The differential expression of 10 genes involved in quorum-sensing, biofilm formation and stress responses was evaluated using reverse-transcription-qPCR. The AHL exposure significantly increased biofilm production in strain ATCC 29212 and two isolates from infected dental roots, UmID4 and UmID5. In strains ATCC 29212 and UmID7, AHLs up-regulated the quorum-sensing genes (fsrC, cylA), the adhesins ace, efaA and asa1, together with the glycosyltransferase epaQ. In strain UmID7, AHL exposure additionally up-regulated two membrane-stress response genes (σ[V], groEL) associated with increased stress-tolerance and virulence. Altogether, our results demonstrate that AHLs promote biofilm formation and up-regulate a transcriptional network involved in virulence and stress tolerance in several E. faecalis strains. These data provide yet-unreported insights into E. faecalis biofilm responses to AHLs, a family of molecules long-considered the monopole of gram-negative signalling.}, }
@article {pmid37187373, year = {2023}, author = {Geng, YK and Gu, J and Zhang, X and Lim, ZK and Jiang, Y and Zhang, M and Zhou, Y and Liu, Y}, title = {Multi-parameter control-based operation strategy for mainstream deammonification in an integrated anaerobic biofilm reactor-step feed MBR.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138941}, doi = {10.1016/j.chemosphere.2023.138941}, pmid = {37187373}, issn = {1879-1298}, abstract = {The mainstream deammonification of municipal wastewater has been recognized as one of the greatest challenges in wastewater engineering. The conventional activated sludge process has disadvantages of high energy input and sludge production. To tackle this situation, an innovative A-B process, where an anaerobic biofilm reactor (AnBR) was functioned as the A stage for energy recovery, and a step-feed membrane bioreactor (MBR) was functioned as the B stage for mainstream deammonification, was constructed for carbon-neutral wastewater treatment. For addressing the challenge associated with selective retention of ammonia-oxidizing bacteria (AOB) over nitrite oxidizing bacteria (NOB), a multi-parameter control-based operation strategy was developed with synergistic control of influent COD redistribution, dissolved oxygen (DO) concentration and sludge retention time (SRT) in the innovative AnBR - step-feed MBR system. Results showed that more than 85% of wastewater COD could be removed with the direct production of methane gas in the AnBR. A relatively stable partial nitritation, which is a prerequisite of anammox, was achieved with the successful suppression of NOB, leading to 98% of ammonium-N and 73% of total nitrogen removed. Anammox bacteria could well survive and enrich in the integrated system, and the contribution of anammox to the total nitrogen removal was more than 70% at optimal conditions. Reactions network involved in the nitrogen transformation in the integrated system was further constructed through the mass balance and microbial community structure analyses. Consequently, this study demonstrated a practically feasible process configuration with high operation and control flexibility towards stable mainstream deammonification of municipal wastewater.}, }
@article {pmid37186226, year = {2023}, author = {Gill, SP and Snelling, WJ and Dooley, JSG and Ternan, NG and Banat, IM and Arnscheidt, J and Hunter, WR}, title = {Biological and synthetic surfactant exposure increases antimicrobial gene occurrence in a freshwater mixed microbial biofilm environment.}, journal = {MicrobiologyOpen}, volume = {12}, number = {2}, pages = {e1351}, pmid = {37186226}, issn = {2045-8827}, abstract = {Aquatic habitats are particularly susceptible to chemical pollution, such as antimicrobials, from domestic, agricultural, and industrial sources. This has led to the rapid increase of antimicrobial resistance (AMR) gene prevalence. Alternate approaches to counteract pathogenic bacteria are in development including synthetic and biological surfactants such as sodium dodecyl sulfate (SDS) and rhamnolipids. In the aquatic environment, these surfactants may be present as pollutants with the potential to affect biofilm formation and AMR gene occurrence. We tested the effects of rhamnolipid and SDS on aquatic biofilms in a freshwater stream in Northern Ireland. We grew biofilms on contaminant exposure substrates deployed within the stream over 4 weeks. We then extracted DNA and carried out shotgun sequencing using a MinION portable sequencer to determine microbial community composition, with 16S rRNA analyses (64,678 classifiable reads identified), and AMR gene occurrence (81 instances of AMR genes over 9 AMR gene classes) through a metagenomic analysis. There were no significant changes in community composition within all systems; however, biofilm exposed to rhamnolipid had a greater number of unique taxa as compared to SDS treatments and controls. AMR gene prevalence was higher in surfactant-treated biofilms, although not significant, with biofilm exposed to rhamnolipids having the highest presence of AMR genes and classes compared to the control or SDS treatments. Our results suggest that the presence of rhamnolipid encourages an increase in the prevalence of AMR genes in biofilms produced in mixed-use water bodies.}, }
@article {pmid37184670, year = {2023}, author = {Hammarén, MM and Luukinen, H and Sillanpää, A and Remans, K and Lapouge, K and Custódio, T and Löw, C and Myllymäki, H and Montonen, T and Seeger, M and Robertson, J and Nyman, TA and Savijoki, K and Parikka, M}, title = {In vitro and ex vivo proteomics of Mycobacterium marinum biofilms and the development of biofilm-binding synthetic nanobodies.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0107322}, doi = {10.1128/msystems.01073-22}, pmid = {37184670}, issn = {2379-5077}, abstract = {The antibiotic-tolerant biofilms present in tuberculous granulomas add an additional layer of complexity when treating mycobacterial infections, including tuberculosis (TB). For a more efficient treatment of TB, the biofilm forms of mycobacteria warrant specific attention. Here, we used Mycobacterium marinum (Mmr) as a biofilm-forming model to identify the abundant proteins covering the biofilm surface. We used biotinylation/streptavidin-based proteomics on the proteins exposed at the Mmr biofilm matrices in vitro to identify 448 proteins and ex vivo proteomics to detect 91 Mmr proteins from the mycobacterial granulomas isolated from adult zebrafish. In vitro and ex vivo proteomics data are available via ProteomeXchange with identifier PXD033425 and PXD039416, respectively. Data comparisons pinpointed the molecular chaperone GroEL2 as the most abundant Mmr protein within the in vitro and ex vivo proteomes, while its paralog, GroEL1, with a known role in biofilm formation, was detected with slightly lower intensity values. To validate the surface exposure of these targets, we created in-house synthetic nanobodies (sybodies) against the two chaperones and identified sybodies that bind the mycobacterial biofilms in vitro and those present in ex vivo granulomas. Taken together, the present study reports a proof-of-concept showing that surface proteomics in vitro and ex vivo proteomics combined are a valuable strategy to identify surface-exposed proteins on the mycobacterial biofilm. Biofilm-surface-binding nanobodies could be eventually used as homing agents to deliver biofilm-targeting treatments to the sites of persistent biofilm infection.}, }
@article {pmid37184412, year = {2023}, author = {Yang, X and Tran, F and Zhang, P}, title = {Comparative Genomic Analyses of Escherichia coli from a Meat Processing Environment in Relation to Their Biofilm Formation and Persistence.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0018323}, doi = {10.1128/spectrum.00183-23}, pmid = {37184412}, issn = {2165-0497}, abstract = {We investigated the phylogeny of biofilm forming (BF) and nonbiofilm forming (NBF) Escherichia coli (n = 114) from a beef processing environment as well as genetic elements in their BF and persistence via a comparative genomic analysis. Phylogroup B1 made up the largest proportion of both the BF (73.8%) and NBF (50.9%) groups. E. coli from all of the sources that were examined had mixed phylogroups, except for those that were recovered from equipment after cleaning, which were exclusively from phylogroup B1. Both the core genome and gene content trees showed a tree-wide spread of BF strains, with clusters, including both BF and NBF strains. Genome-wide association studies (GWAS) via Scoary or Pyseer did not find any genes or mutations that were overrepresented in the BF group. A retrospective analysis of phenotypes found a significant correlation (P < 0.05) between BF ability and curli production, cellulose synthesis, and/or mobility. However, the BF group also included strains that were negative for curli and cellulose and/or missing encoding genes for the two traits. All curli and cellulose encoding genes were present in most genomes, regardless of their BF status. The degree of motility was correlated with both curli and cellulose production, and 80 common genes were overrepresented in all three of the trait-positive groups. A PTS enzyme II, a subsidiary gluconate catabolism pathway, and an iron-dicitrate transport system were more abundant in the persisting E. coli group. These findings suggest gene function redundancy in E. coli for biofilm formation as well as additional substrate utilization and iron acquisition in its persistence. IMPORTANCE The persistence of potentially hazardous bacteria is a major challenge for meat processing environments, which are conducive for biofilm formation. Marker genes/phenotypes are commonly used to differentiate biofilm forming E. coli strains from their nonbiofilm forming counterparts. We took a comparative genomic analysis approach to analyze E. coli strains that were from the same environment but were differentiated by their biofilm forming ability. A diversification of the genes involved in the biofilm formation of E. coli was observed. Even though there is a correlation on the population level between biofilm formation and the expression of curli and cellulose, uncertainties exist on the individual strain level. Novel substrate utilization and iron acquisition could contribute to the persistence of E. coli. These findings not only advance our understanding of the ecology of E. coli with respect to its persistence but also show that a marker gene/phenotype driven approach for the biofilm control of E. coli may not be prudent.}, }
@article {pmid37183189, year = {2023}, author = {Thaarup, IC and Lichtenberg, M and Nørgaard Master, KTH and Xu, Y and Lorenzen, J and Thomsen, TR and Bjarnsholt, T}, title = {A collagen-based layered chronic wound biofilm model for testing antimicrobial wound products.}, journal = {Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society}, volume = {}, number = {}, pages = {}, doi = {10.1111/wrr.13087}, pmid = {37183189}, issn = {1524-475X}, abstract = {A new in vitro chronic wound biofilm model was recently published, which provided a layered scaffold simulating mammalian tissue composition on which topical wound care products could be tested. In this paper, we updated the model even further to mimic the dynamic influx of nutrients from below as is the case in a chronic wound. The modified in vitro model was created using collagen instead of agar as the main matrix component and contained both Staphylococcus aureus and Pseudomonas aeruginosa. The model was cast in transwell inserts and then placed in wound simulating media, which allowed for an exchange of nutrients and waste products across a filter. Three potential wound care products and chlorhexidine digluconate 2% solution as a positive control were used to evaluate the model. The tested products were composed of hydrogels made from completely biodegradable starch microspheres carrying different active compounds. The compounds were applied topically and left for 2-4 days. Profiles of oxygen concentration and pH were measured to assess the effect of treatments on bacterial activity. Confocal microscope images were obtained of the models to visualise the existence of microcolonies. Results showed that the modified in vitro model maintained a stable number of the two bacterial species over 6 days. In untreated models, steep oxygen gradients developed and pH increased to >8.0. Hydrogels containing active compounds alleviated the high oxygen consumption and decreased pH drastically. Moreover, all three hydrogels reduced the colony forming units significantly and to a larger extent than the chlorhexidine control treatment. Overall, the modified model expressed several characteristics similar to in vivo chronic wounds. This article is protected by copyright. All rights reserved.}, }
@article {pmid37182783, year = {2023}, author = {Zhou, T and Xiang, Y and Liu, S and Shao, Z and Liu, Y and Ma, H and He, Q and Chai, H}, title = {Insights into simultaneous nitrogen and phosphorus removal in biofilm: The overlooked comammox Nitrospira and the positive role of glycogen-accumulating organisms.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {164130}, doi = {10.1016/j.scitotenv.2023.164130}, pmid = {37182783}, issn = {1879-1026}, abstract = {Simultaneous nitrogen and phosphorus removal (SNPR) biofilm system is an effective wastewater treatment process. However, the understanding on the mechanism of functional microorganisms driving SNPR is still limited, especially the role of complete ammonia oxidation (comammox) Nitrospira and glycogen-accumulating organisms (GAO). In this study, a sequencing batch biofilm reactor (SBBR) performing SNPR was operated for 249 d. Based on the 16S rRNA gene, comammox amoA amplicon sequencing, metagenomics and batch experiment, we found that comammox Nitrospira was the main ammonia-oxidizing microorganisms (AOM) and provided nitrite for anaerobic ammonia oxidation (anammox) bacteria (AnAOB). Besides, GAO was dominated by the bacteria of genus Defluviicoccus and played a primary role in reducing nitrate rather than nitrite. Fluorescent in situ hybridization (FISH) analysis confirmed that Nitrospira was enriched in the inner layer of the biofilm. Thus, we put forward a novel insight into the mechanism of SNPR biofilm system. Comammox Nitrospira was responsible for nitrite and nitrate production in the inner biofilm, and AnAOB consumed the produced nitrite during the anammox process. While GAO reduced nitrate to nitrite and polyphosphate-accumulating organisms (PAO) converted nitrite to dinitrogen via denitrifying phosphorus removal in the outer biofilm. These findings provide a new understanding in SNPR biofilm system.}, }
@article {pmid37180695, year = {2023}, author = {Teimoorian, M and Mirzaie, M and Tashakkorian, H and Gholinia, H and Alaghemand, H and Pournajaf, A and Ghorbanipour, R}, title = {Effects of adding functionalized graphene oxide nanosheets on physical, mechanical, and anti-biofilm properties of acrylic resin: In vitro- experimental study.}, journal = {Dental research journal}, volume = {20}, number = {}, pages = {37}, pmid = {37180695}, issn = {1735-3327}, abstract = {BACKGROUND: Polymethyl methacrylate resin is widely used in orthodontic treatments. Graphene oxide (GO) has reactive functional groups on its surface that facilitate binding to various materials such as polymers, biomolecules, DNA, and proteins. This study aimed to investigate the impact of adding functionalized GO nanosheets on the physical, mechanical, cytotoxicity, and anti-biofilm properties of acrylic resin.<br><br>MATERIALS AND METHODS: In this experimental study, fifty samples (for each test) were divided into groups of 10, in the form of acrylic resin discs with concentrations of 0, 0.25, 0.5, 1, and 2 weight percentage (wt%) of functionalized GO nanosheets and also the control group. Samples were evaluated in terms of physical properties (surface hardness, surface roughness, compressive strength, fracture toughness, and flexural strength), anti-biofilm properties (On four groups of micro-organisms, including Streptococcus mutans, Streptococcus sanguis, Staphylococcus aureus, and Candida albicans), and cytotoxicity. Data were analyzed using SPSS software version 22, descriptive statistics, one-way analysis of variance test, and Tukey post hoc test. The significance level was considered P < 0.05.<br><br>RESULTS: No significant difference was observed between the different groups with weight percentages of 0.25, 0.5, 1, and 2% nano GO (nGO) and the control group (without nGO) in terms of surface roughness and toughness. However, compressive strength, three-point flexural strength, and surface hardness showed significant differences between the groups. Furthermore, the degree of cytotoxicity increased by increasing the weight percentage of nano-GO.<br><br>CONCLUSION: The addition of functionalized nGO in appropriate concentrations to polymethyl methacrylate can improve the anti-bacterial and anti-fungal biofilm properties without changing or increasing their physical and mechanical properties.}, }
@article {pmid37180277, year = {2023}, author = {Wang, C and Xiong, Y and Bao, C and Wei, Y and Wen, Z and Cao, X and Yu, Z and Deng, X and Li, G and Deng, Q}, title = {Antibacterial and anti-biofilm activity of radezolid against Staphylococcus aureus clinical isolates from China.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1131178}, pmid = {37180277}, issn = {1664-302X}, abstract = {Although the potent antibacterial ability of radezolid against Staphylococcus aureus has been widely reported worldwide, its antibacterial and anti-biofilm activity against the S. aureus clinical isolates from China remains elusive. In this study, the minimum inhibitory concentration (MIC) of radezolid was determined in S. aureus clinical isolates from China using the agar dilution method, and the relationship between radezolid susceptibility and ST distribution was also investigated. The anti-biofilm activity of radezolid against S. aureus was determined by a crystal violet assay and compared with that of linezolid and contezolid. The quantitative proteomics of S. aureus treated with radezolid was analyzed, and the genetic mutations in radezolid-induced resistant S. aureus were determined by whole-genome sequencing. The dynamic changes in transcriptional expression levels of several biofilm-related genes were analyzed by quantitative RT-PCR. Our data showed that radezolid MIC ranged from ≤0.125 to 0.5 mg/L, which was almost 1/4 × MIC of linezolid against S. aureus, indicating the greater antibacterial activity of radezolid than linezolid. The S. aureus clinical isolates with radezolid MICs of 0.5 mg/L were most widely distributed in ST239 of MRSA and ST7 of MSSA. Moreover, the more robust anti-biofilm activity of radezolid with subinhibitory concentrations (1/8 × MIC and 1/16 × MIC) was demonstrated against S. aureus when compared with that of contezolid and linezolid. Genetic mutations were found in glmS, 23S rRNA, and DUF1542 domain-containing protein in radezolid-induced resistant S. aureus selected by in vitro induction of drug exposure. Quantitative proteomic analysis of S. aureus indicated that the global expression of some biofilm-related and virulence-related proteins was downregulated. Quantitative RT-PCR further confirmed that the expressions of some downregulated biofilm-related proteins, including sdrD, carA, sraP, hlgC, sasG, spa, sspP, fnbA, and oatA, were decreased after 12 h and 24 h of exposure to radezolid. Conclusively, radezolid shows robust antibacterial and anti-biofilm activity against S. aureus clinical isolates from China when compared with contezolid and linezolid.}, }
@article {pmid37179329, year = {2023}, author = {Anderson, AC and von Ohle, C and Frese, C and Boutin, S and Bridson, C and Schoilew, K and Peikert, SA and Hellwig, E and Pelz, K and Wittmer, A and Wolff, D and Al-Ahmad, A}, title = {The oral microbiota is a reservoir for antimicrobial resistance: resistome and phenotypic resistance characteristics of oral biofilm in health, caries, and periodontitis.}, journal = {Annals of clinical microbiology and antimicrobials}, volume = {22}, number = {1}, pages = {37}, pmid = {37179329}, issn = {1476-0711}, mesh = {Humans ; Anti-Bacterial Agents/pharmacology ; Drug Resistance, Bacterial/genetics ; Dental Caries Susceptibility ; *Microbiota/genetics ; *Periodontitis/genetics ; Bacteria ; Genes, Bacterial ; }, abstract = {BACKGROUND: Antimicrobial resistance (AMR) is an ever-growing threat to modern medicine and, according to the latest reports, it causes nearly twice as many deaths globally as AIDS or malaria. Elucidating reservoirs and dissemination routes of antimicrobial resistance genes (ARGs) are essential in fighting AMR. Human commensals represent an important reservoir, which is underexplored for the oral microbiota. Here, we set out to investigate the resistome and phenotypic resistance of oral biofilm microbiota from 179 orally healthy (H), caries active (C), and periodontally diseased (P) individuals (TRN: DRKS00013119, Registration date: 22.10.2022). The samples were analysed using shotgun metagenomic sequencing combined, for the first time, with culture technique. A selection of 997 isolates was tested for resistance to relevant antibiotics.<br><br>RESULTS: The shotgun metagenomics sequencing resulted in 2,069,295,923 reads classified into 4856 species-level OTUs. PERMANOVA analysis of beta-diversity revealed significant differences between the groups regarding their microbiota composition and their ARG profile. The samples were clustered into three ecotypes based on their microbial composition. The bacterial composition of H and C samples greatly overlapped and was based on ecotypes 1 and 2 whereas ecotype 3 was only detected in periodontitis. We found 64 ARGs conveying resistance to 36 antibiotics, particularly to tetracycline, macrolide-lincosamide-streptogramin, and beta-lactam antibiotics, and a correspondingly high prevalence of phenotypic resistance. Based on the microbiota composition, these ARGs cluster in different resistotypes, and a higher prevalence is found in healthy and caries active than in periodontally diseased individuals. There was a significant association between the resistotypes and the ecotypes. Although numerous associations were found between specific antibiotic resistance and bacterial taxa, only a few taxa showed matching associations with both genotypic and phenotypic analyses.<br><br>CONCLUSIONS: Our findings show the importance of the oral microbiota from different niches within the oral cavity as a reservoir for antibiotic resistance. Additionally, the present study showed the need for using more than one method to reveal antibiotic resistance within the total oral biofilm, as a clear mismatch between the shotgun metagenomics method and the phenotypic resistance characterization was shown.}, }
@article {pmid37177837, year = {2023}, author = {Bae, WY and Jung, WH and Lee, YJ and Shin, SL and An, YK and Kim, TR and Sohn, M}, title = {Heat-treated Pediococcus acidilactici LM1013-mediated inhibition of biofilm formation by Cutibacterium acnes and its application in acne vulgaris: A single-arm clinical trial.}, journal = {Journal of cosmetic dermatology}, volume = {}, number = {}, pages = {}, doi = {10.1111/jocd.15809}, pmid = {37177837}, issn = {1473-2165}, abstract = {PURPOSE: Acne vulgaris is a common skin disease accompanied by chronic inflammation in the pilosebaceous follicles, resulting from excessive Cutibacterium acnes. This study aimed to investigate the inhibition of biofilm formation by C. acnes ATCC 6919 using heat-treated Pediococcus acidilactici LM1013 (HT-LM1013), previously isolated from the Korean traditional fermented alcoholic beverage-makgeolli, and its application as a leave-on-type product for patients with acne vulgaris.<br><br>METHODS: HT-LM1013 was prepared by Lactomason and homogenized using a high-pressure homogenizer. The minimum inhibitory concentration (MIC), tricarboxylic acid (TCA) cycle, and lipase activity were evaluated for C. acnes inhibition. Inhibition of biofilm formation was demonstrated using a crystal violet solution. Damaged C. acnes was observed using field-emission scanning electron microscopy (FE-SEM). Clinical trials were performed using a leave-on-type product containing HT-LM1013.<br><br>RESULTS: HT-LM1013 inhibited the TCA cycle (36.80%) and lipase activity using palmitate (31.89%), stearate (36.91%), and oleate (30.86%) as substrates at 1&#x2009;&#xd7;&#x2009;MIC (p&#x2009;<&#x2009;0.01). After treatment with HT-LM1013, concave and elongated shapes of C. acnes were observed by FE-SEM. In addition, HT-LM1013 inhibited biofilm formation by 71.75% at 1&#x2009;&#xd7;&#x2009;MIC (p&#x2009;<&#x2009;0.001) and removed 73.35% of mature biofilms (p&#x2009;<&#x2009;0.01). In the clinical trial, the leave-on-type product decreased the number of closed comedones from 14.04 to 10.22, open comedones from 7.22 to 4.39%, and sebum content to 76.23% at week 4 (p&#x2009;<&#x2009;0.01). The satisfaction score of the participants was recorded 3.83 on a five-point scale.<br><br>CONCLUSION: HT-LM1013 is potent for the treatment of acne vulgaris.}, }
@article {pmid37177285, year = {2023}, author = {Vulović, S and Nikolić-Jakoba, N and Radunović, M and Petrović, S and Popovac, A and Todorović, M and Milić-Lemić, A}, title = {Biofilm Formation on the Surfaces of CAD/CAM Dental Polymers.}, journal = {Polymers}, volume = {15}, number = {9}, pages = {}, pmid = {37177285}, issn = {2073-4360}, abstract = {Dental polymers are now available as monolithic materials which can be readily used in computer-aided design and computer-aided manufacturing (CAD/CAM) systems. Despite possessing numerous advantages over conventionally produced polymers, the polymers produced by either of these systems fail to exhibit immunity to surface microbial adhesion when introduced into the oral environment, leading to the development of oral diseases. The aim of this study was to analyze the biofilm formation of six microorganisms from the oral cavity and its correlation to the surface characteristics of CAD/CAM dental polymers. A total of ninety specimens were divided into three groups: resin-based composite, polymethyl methacrylate, and polyether ether ketone. The experimental procedure included surface roughness and water contact angle measurements, colony forming unit counting, and scanning electron microscopy analysis of biofilm formed on the surface of the tested materials. The data were analyzed using the Kruskal-Wallis test, with a Dunn's post hoc analysis, and one way analysis of variance, with a Tukey's post hoc test; the correlation between the measurements was tested using Spearman's correlation coefficient, and descriptive statistics were used to present the data. Despite using the same manufacturing procedure, as well as the identical manufacturer's finishing and polishing protocols, CAD/CAM dental polymers revealed significant differences in surface roughness and water contact angle, and the increased values of both parameters led to an increase in biofilm formation on the surface of the materials. The CAD/CAM resin-based composite showed the lowest number of adhered microorganisms compared to CAD/CAM polymethyl methacrylate and CAD/CAM polyether ether ketone.}, }
@article {pmid37175289, year = {2023}, author = {Ye, X and Mao, S and Li, Y and Yang, Z and Du, A and Wang, H}, title = {Design, Synthesis, and Biological Evaluation of Phenyloxadiazole Sulfoxide Derivatives as Potent Pseudomonas aeruginosa Biofilm Inhibitors.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {9}, pages = {}, pmid = {37175289}, issn = {1420-3049}, abstract = {With the development of antimicrobial agents, researchers have developed new strategies through key regulatory systems to block the expression of virulence genes without affecting bacterial growth. This strategy can minimize the selective pressure that leads to the emergence of resistance. Quorum sensing (QS) is an intercellular communication system that plays a key role in the regulation of bacterial virulence and biofilm formation. Studies have revealed that the QS system controls 4-6% of the total number of P. aeruginosa genes, and quorum sensing inhibitors (QSIs) could be a promising target for developing new prevention and treatment strategies against P. aeruginosa infection. In this study, four series of phenyloxadiazole and phenyltetrazole sulfoxide derivatives were synthesized and evaluated for their inhibitory effects on P. aeruginosa PAO1 biofilm formation. Our results showed that 5b had biofilm inhibitory activity and reduced the production of QS-regulated virulence factors in P. aeruginosa. In addition, silico molecular docking studies have shown that 5b binds to the P. aeruginosa QS receptor protein LasR through hydrogen bond interaction. Preliminary structure-activity relationship and docking studies show that 5b has broad application prospects as an anti-biofilm compound, and further research will be carried out in the future to solve the problem of microbial resistance.}, }
@article {pmid37174548, year = {2023}, author = {Gao, M and Zuo, J and Shen, Y and Yuan, S and Gao, S and Wang, Y and Wang, Y and Yi, L}, title = {Modeling Co-Infection by Streptococcus suis and Haemophilus parasuis Reveals Influences on Biofilm Formation and Host Response.}, journal = {Animals : an open access journal from MDPI}, volume = {13}, number = {9}, pages = {}, pmid = {37174548}, issn = {2076-2615}, abstract = {Streptococcus suis (S. suis) and Haemophilus parasuis (H. parasuis) are two primary pathogens currently affecting the porcine industry. They often cause encephalitis and arthritis. They also frequently co-infect in clinical settings. In the current study, we identified significant correlations between S. suis and H. parasuis. The results from CI versus RIR suggested that S. suis and H. parasuis were competitive in general. Compared to mono-species biofilm, the biomass, bio-volume, and thickness of mixed-species biofilms were significantly higher, which was confirmed using crystal violet staining, confocal laser scanning microscopy, and scanning electron microscopy. Compared to mono-species biofilm, the viable bacteria in the mixed-species biofilms were significantly lower, which was confirmed using the enumeration of colony-forming units (CFU cm[-2]). The susceptibility of antibiotics in the co-culture decreased in the planktonic state. In contrast, biofilm state bacteria are significantly more difficult to eradicate with antibiotics than in a planktonic state. Whether in planktonic or biofilm state, the expression of virulence genes of S. suis and H. parasuis in mixed culture was very different from that in single culture. Subsequently, by establishing a mixed infection model in mice, we found that the colonization of the two pathogens in organs increased after mixed infection, and altered the host's inflammatory response. In summary, our results indicate that S. suis and H. parasuis compete when co-cultured in vitro. Surprisingly, S. suis and H. parasuis synergistically increased colonization capacity after co-infection in vivo. This study elucidated the interaction between S. suis and H. parasuis during single infections and co-infections. Future studies on bacterial disease control and antibiotic treatment should consider the interaction of mixed species.}, }
@article {pmid37174455, year = {2023}, author = {Thames, HT and Pokhrel, D and Willis, E and Rivers, O and Dinh, TTN and Zhang, L and Schilling, MW and Ramachandran, R and White, S and Sukumaran, AT}, title = {Salmonella Biofilm Formation under Fluidic Shear Stress on Different Surface Materials.}, journal = {Foods (Basel, Switzerland)}, volume = {12}, number = {9}, pages = {}, pmid = {37174455}, issn = {2304-8158}, abstract = {This study characterized biofilm formation of various Salmonella strains on common processing plant surface materials (stainless steel, concrete, rubber, polyethylene) under static and fluidic shear stress conditions. Surface-coupons were immersed in well-plates containing 1 mL of Salmonella (6 log CFU/mL) and incubated aerobically for 48 h at 37 °C in static or shear stress conditions. Biofilm density was determined using crystal violet assay, and biofilm cells were enumerated by plating on tryptic soy agar plates. Biofilms were visualized using scanning electron microscopy. Data were analyzed by SAS 9.4 at a significance level of 0.05. A surface-incubation condition interaction was observed for biofilm density (p < 0.001). On stainless steel, the OD600 was higher under shear stress than static incubation; whereas, on polyethylene, the OD600 was higher under static condition. Enumeration revealed surface-incubation condition (p = 0.024) and surface-strain (p < 0.001) interactions. Among all surface-incubation condition combinations, the biofilm cells were highest on polyethylene under fluidic shear stress (6.4 log/coupon; p < 0.001). Biofilms of S. Kentucky on polyethylene had the highest number of cells (7.80 log/coupon) compared to all other strain-surface combinations (p < 0.001). Electron microscopy revealed morphological and extracellular matrix differences between surfaces. Results indicate that Salmonella biofilm formation is influenced by serotype, surface, and fluidic shear stress.}, }
@article {pmid37172659, year = {2023}, author = {Kang, CE and Park, YJ and Kim, JH and Lee, NK and Paik, HD}, title = {Probiotic Weissella cibaria displays antibacterial and anti-biofilm effect against cavity-causing Streptococcus mutans.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106151}, doi = {10.1016/j.micpath.2023.106151}, pmid = {37172659}, issn = {1096-1208}, abstract = {Streptococcus mutans is a significant contributor to dental caries and causes functional and aesthetic discomfort. Weissella cibaria strains were isolated from kimchi, and their functional properties were determined. In this study, the antibacterial and antibiofilm effects of four W. cibaria strains (D29, D30, D31, and B22) were evaluated against three S. mutans strains using culture fluid and cell-free supernatants. The results showed that W. cibaria reduced the exopolysaccharides production and auto-aggregation, increased co-aggregation, and downregulated virulence factors, leading to the inhibition of bacterial growth and biofilm formation. These findings were confirmed using scanning electron microscopy and confocal laser scanning microscopy. These results indicate that oral health can be potentially improved by W. cibaria.}, }
@article {pmid37172383, year = {2023}, author = {Liu, YJ and Li, ZH and He, YT and Yuan, L and Sheng, GP}, title = {Antibiotic resistomes in face-mask biofilm along an urban river: Multiple drivers and co-occurrence with human opportunistic pathogens.}, journal = {Journal of hazardous materials}, volume = {455}, number = {}, pages = {131587}, pmid = {37172383}, issn = {1873-3336}, abstract = {Discarded face masks from the global COVID-19 pandemic have contributed significantly to plastic pollution in surface water, whereas their potential as a reservoir for aquatic pollutants is not well understood. Herein, we conducted a field experiment along a human-impacted urban river, investigating the variations of antibiotic resistance genes (ARGs), pathogens, and water-borne contaminants in commonly-used face masks. Results showed that high-biomass biofilms formed on face masks selectively enriched more ARGs than stone biofilm (0.08-0.22 vs 0.07-0.15 copies/16 S rRNA gene copies) from bulk water, which mainly due to unique microbial communities, enhanced horizontal gene transfer, and selective pressure of accumulated contaminants based on redundancy analysis and variation partitioning analysis. Several human opportunistic pathogens (e.g., Acinetobacter, Escherichia-Shigella, Bacillus, and Klebsiella), which are considered potential ARG carriers, were also greatly concentrated in face-mask biofilms, imposing a potential threat to aquatic ecological environment and human health. Moreover, wastewater treatment plant effluents, as an important source of pollutants to urban rivers, further aggravated the abundances of ARGs and opportunistic pathogens in face-mask biofilms. Our findings demonstrated that discarded face masks provide a hotspot for the proliferation and spread of ARGs and pathogens in urban water, highlighting the urgent requirement for implementing stricter regulations in face mask disposal.}, }
@article {pmid37171757, year = {2023}, author = {Roy, B and Maitra, D and Biswas, A and Chowdhury, N and Ganguly, S and Bera, M and Dutta, S and Golder, S and Roy, S and Ghosh, J and Mitra, AK}, title = {Efficacy of High-Altitude Biofilm-Forming Novel Bacillus subtilis Species as Plant Growth-Promoting Rhizobacteria on Zea mays L.}, journal = {Applied biochemistry and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {37171757}, issn = {1559-0291}, abstract = {With the global population explosion, the need for increasing crop productivity is reaching its peak. The significance of organic means of cultivation including biofertilizers and biopesticides is undeniable in this context. Over the last few decades, the use of rhizobacteria to induce crop productivity has gained particular interest of researchers. Of these, several Bacillus spp. have been known for their potential plant growth-promoting and phyto-pathogenic actions. Keeping this background in mind, this study was formulated with an aim to unravel the PGPR and phyto-pathogenic potency of Bacillus sp. isolated from extreme environmental conditions, viz. high-altitude waters of Ganges at Gangotri (Basin Extent Longitude Latitude-73° 2' to 89° 5' E 21° 6' to 31° 21' N). Based on recent studies showing the impact of biofilm on bacterial PGPR potency, three novel strains of Bacillus subtilis were isolated on basis of their extremely high biofilm-producing abilities (BRAM_G1: Accession Number MW006633; BRAM_G2: Accession Numbers MT998278-MT998280; BRAM_G3: Accession Number MT998617), and were tested for their PGPR properties like nutrient sequestration, growth hormone production (IAA, GA3), stress-responsive enzyme production (ACC deaminase) and lignocellulolytic and agriculturally important enzyme productions. The strains were further tested for the plethora of metabolites (liquid and VOCs) exuded by them. Finally, the strains both in individually and in an association, i.e. consortium was tested on a test crop, viz. Zea mays L., and the data were collected at regular intervals and the results were statistically analysed. In the present study, the role of high-altitude novel Bacillus subtilis strains as potent PGPR has been analysed statistically.}, }
@article {pmid37170818, year = {2023}, author = {Snowdon, AA and Dennington, SP and Longyear, JE and Wharton, JA and Stoodley, P}, title = {Surface properties influence marine biofilm rheology, with implications for ship drag.}, journal = {Soft matter}, volume = {}, number = {}, pages = {}, doi = {10.1039/d2sm01647h}, pmid = {37170818}, issn = {1744-6848}, abstract = {Marine biofilms on ship hulls increase frictional drag, which has economic and environmental consequences. It is hypothesised that biofilm mechanics, such as viscoelasticity, play a critical role in biofilm-associated drag, yet is a poorly studied area. The current study aimed to rheologically characterise ship-relevant marine biofilms. To combat marine biofilms on ship hulls, fouling-control coatings are often applied; therefore, the effect of different surfaces on marine biofilm mechanics was also investigated. Three surfaces were tested: a non-biocidal, chemically inert foul-release coating (FRC), an inert primer (ACP) and inert PVC. Physical properties of biofilms were explored using Optical Coherence Tomography (OCT) and a parallel-plate rheometer was used for rheological testing. Image analysis revealed differences in the thickness, roughness, and percent coverage between the different biofilms. Rheological testing showed that marine biofilms, grown on FRC and ACP acted as viscoelastic materials, although there were differences. FRC biofilms had a lower shear modulus, a higher viscosity, and a higher yield stress than the ACP biofilms, suggesting that the FRC biofilms were more readily deformable but potentially more robust. The results confirmed that surface treatment influences the structural and mechanical properties of ship-relevant marine biofilms, which could have implications for drag. A better understanding of how different surface treatments affect marine biofilm rheology is required to improve our knowledge on biofilm fluid-structure interactions and to better inform the coating industry of strategies to control biofilm formation and reduce drag.}, }
@article {pmid37170476, year = {2023}, author = {Delaney, C and Alapati, S and Alshehri, M and Kubalova, D and Veena, CLR and Abusrewil, S and Short, B and Bradshaw, D and Brown, JL}, title = {Investigating the role of Candida albicans as a universal substrate for oral bacteria using a transcriptomic approach: implications for interkingdom biofilm control?.}, journal = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica}, volume = {}, number = {}, pages = {}, doi = {10.1111/apm.13327}, pmid = {37170476}, issn = {1600-0463}, abstract = {Candida albicans is frequently identified as a colonizer of the oral cavity in health and has recently been termed a "keystone" commensal due to its role on the bacterial communities. However, the role that C. albicans plays in such interactions is not fully understood. Therefore, this study aimed to identify the relationship between C. albicans and bacteria associated with oral symbiosis and dysbiosis. To do this, we evaluated the ability of C. albicans to support the growth of the aerobic commensal Streptococcus gordonii and the anaerobic pathogens Fusobacterium nucleatum and Porphyromonas gingivalis in the biofilm environment. RNA-Sequencing with the Illumina platform was then utilized to identify C. albicans gene expression and functional pathways involved during such interactions in dual-species and a 4-species biofilm model. Results indicated that C. albicans was capable of supporting growth of all three bacteria, with a significant increase in colony counts of each bacteria in the dual-species biofilm (p < 0.05). We identified specific functional enrichment of pathways in our 4-species community as well as transcriptional profiles unique to the F. nucleatum and S. gordonii dual-species biofilms, indicating a species-specific effect on C. albicans. Candida-related hemin acquisition and heat shock protein mediated processes were unique to the organism following co-culture with anaerobic and aerobic bacteria, respectively, suggestive that such pathways may be feasible options for therapeutic targeting to interfere with these fungal-bacterial interactions. Targeted antifungal therapy may be considered as an option for biofilm destabilization and treatment of complex communities. Moving forward, we propose that further studies must continue to investigate the role of this fungal organism in the context of the interkingdom nature of oral diseases.}, }
@article {pmid37169797, year = {2023}, author = {Auria, E and Hunault, L and England, P and Monot, M and Pipoli Da Fonseca, J and Matondo, M and Duchateau, M and Tremblay, YDN and Dupuy, B}, title = {The cell wall lipoprotein CD1687 acts as a DNA binding protein during deoxycholate-induced biofilm formation in Clostridioides difficile.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {24}, pmid = {37169797}, issn = {2055-5008}, abstract = {The ability of bacterial pathogens to establish recurrent and persistent infections is frequently associated with their ability to form biofilms. Clostridioides difficile infections have a high rate of recurrence and relapses and it is hypothesized that biofilms are involved in its pathogenicity and persistence. Biofilm formation by C. difficile is still poorly understood. It has been shown that specific molecules such as deoxycholate (DCA) or metronidazole induce biofilm formation, but the mechanisms involved remain elusive. In this study, we describe the role of the C. difficile lipoprotein CD1687 during DCA-induced biofilm formation. We showed that the expression of CD1687, which is part of an operon within the CD1685-CD1689 gene cluster, is controlled by multiple transcription starting sites and some are induced in response to DCA. Only CD1687 is required for biofilm formation and the overexpression of CD1687 is sufficient to induce biofilm formation. Using RNAseq analysis, we showed that CD1687 affects the expression of transporters and metabolic pathways and we identified several potential binding partners by pull-down assay, including transport-associated extracellular proteins. We then demonstrated that CD1687 is surface exposed in C. difficile, and that this localization is required for DCA-induced biofilm formation. Given this localization and the fact that C. difficile forms eDNA-rich biofilms, we confirmed that CD1687 binds DNA in a non-specific manner. We thus hypothesize that CD1687 is a component of the downstream response to DCA leading to biofilm formation by promoting interaction between the cells and the biofilm matrix by binding eDNA.}, }
@article {pmid37168114, year = {2023}, author = {Németh, A and Ainsworth, J and Ravishankar, H and Lens, PNL and Heffernan, B}, title = {Temperature dependence of nitrification in a membrane-aerated biofilm reactor.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1114647}, pmid = {37168114}, issn = {1664-302X}, abstract = {The membrane-aerated biofilm reactor (MABR) is a novel method for the biological treatment of wastewaters and has been successfully applied for nitrification. To improve the design and adaptation of MABR processes for colder climates and varying temperatures, the temperature dependence of a counter-diffusional biofilm's nitrification performance was investigated. A lab-scale MABR system with silicone hollow fibre membranes was operated at various temperatures between 8 and 30°C, and batch tests were performed to determine the ammonia oxidation kinetics. Biofilm samples were taken at 8 and 24°C and analysed with 16S rRNA sequencing to monitor changes in the microbial community composition, and a mathematical model was used to study the temperature dependence of mass transfer. A high nitrification rate (3.08 g N m[-2] d[-1]) was achieved at 8°C, and temperature dependence was found to be low (θ = 1.024-1.026) compared to suspended growth processes. Changes in the community composition were moderate, Nitrospira defluvii remaining the most dominant species. Mass transfer limitations were shown to be largely responsible for the observed trends, consistent with other biofilm processes. The results show that the MABR is a promising technology for low temperature nitrification, and appropriate management of the mass transfer resistance can optimise the process for both low and high temperature operation.}, }
@article {pmid37166296, year = {2023}, author = {Shen, L and Zhang, J and Chen, Y and Rao, L and Wang, X and Zhao, H and Wang, B and Xiao, Y and Yu, J and Xu, Y and Shi, J and Han, W and Song, Z and Yu, F}, title = {Small-Molecule Compound CY-158-11 Inhibits Staphylococcus aureus Biofilm Formation.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0004523}, doi = {10.1128/spectrum.00045-23}, pmid = {37166296}, issn = {2165-0497}, abstract = {Staphylococcus aureus is an important human pathogen and brings about many community-acquired, hospital-acquired, and biofilm-associated infections worldwide. It tends to form biofilms, triggering the release of toxins and initiating resistance mechanisms. As a result of the development of S. aureus tolerance to antibiotics, there are few drugs can availably control biofilm-associated infections. In this study, we synthesized a novel small-molecule compound CY-158-11 (C22H14Cl2NO2Se2) and proved its inhibitory effect on the biofilm formation of S. aureus at a subinhibitory concentration (1/8 MIC). The subinhibitory concentration of CY-158-11 not only did not affect the growth of bacteria but also had no toxicity to A549 cells or G. mellonella. Total biofilm biomass was investigated by crystal violet staining, and the results were confirmed by SYTO 9 and PI staining through confocal laser scanning microscopy. Moreover, CY-158-11 effectively prevented initial attachment and repressed the production of PIA instead of autolysis. RT-qPCR analysis also exhibited significant suppression of the genes involved in biofilm formation. Taken together, CY-158-11 exerted its inhibitory effects against the biofilm formation in S. aureus by inhibiting cell adhesion and the expression of icaA related to PIA production. IMPORTANCE Most bacteria exist in the form of biofilms, often strongly adherent to various surfaces, causing bacterial resistance and chronic infections. In general, antibacterial drugs are not effective against biofilms. The small-molecule compound CY-158-11 inhibited the biofilm formation of S. aureus at a subinhibitory concentration. By hindering adhesion and PIA-mediated biofilm formation, CY-158-11 exhibits antibiofilm activity toward S. aureus. These findings point to a novel therapeutic agent for combating intractable S. aureus-biofilm-related infections.}, }
@article {pmid37165699, year = {2023}, author = {Russo, A and Gatti, A and Felici, S and Gambardella, A and Fini, M and Neri, MP and Zaffagnini, S and Lazzarotto, T}, title = {Piezoelectric ultrasonic debridement as new tool for biofilm removal from orthopaedic implants: a study in vitro.}, journal = {Journal of orthopaedic research : official publication of the Orthopaedic Research Society}, volume = {}, number = {}, pages = {}, doi = {10.1002/jor.25599}, pmid = {37165699}, issn = {1554-527X}, abstract = {Pulse lavage (PL) debridement is the standard treatment used in Debridement, Antibiotics and Implant Retention (DAIR) for bacterial biofilm removal during acute and early post-operative cases of periprosthetic joint infection (PJI). The failure rate of DAIR is still high due to the inadequacy of PL in removing the biofilm. Ultrasound-based techniques are a well-established tool for PJI diagnosis due to their ability to completely eradicate the biofilm from implant surfaces. Hence, this study investigates the efficiency of a piezoelectric ultrasonic scalpel (PUS) in removing bacterial biofilm from different orthopedic implant materials in vitro and compares the results with PL. Biofilms of methicillin-resistant Staphylococcus aureus strains were grown on titanium alloy (Ti6Al4V ELI), stainless steel (AISI 316L) and ultra-high molecular weight polyethylene (UHMWPE) disks for 24 h. The disks of each material were divided into three groups: (i) a control group (no lavage/debridement), (ii) a group treated with PL, (iii) a group treated with PUS. The disks were then sonicated for viable cell count to measure the residual biofilm content. Compared to the initial cell count (10[5] CFU/ml for each material), PL showed a two-log reduction of CFU/ml (p < 0.001 for each material), while for PUS a four-log reduction was found (p < 0.001 for each material). The comparison between the two lavage/debridement displayed a two-log reduction of CFU/ml (p < 0.001 for each material) of PUS compared with PL. Its increased efficiency compared with PL promotes the use of PUS in removing bacterial biofilm from orthopedic implants, suggesting its implementation to improve the success rate of DAIR This article is protected by copyright. All rights reserved.}, }
@article {pmid37165063, year = {2023}, author = {Kato, H and Okino, N and Kijitori, H and Izawa, Y and Wada, Y and Maki, M and Yamamoto, T and Yano, T}, title = {Analysis of biofilm and bacterial communities in the towel environment with daily use.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {7611}, pmid = {37165063}, issn = {2045-2322}, mesh = {Humans ; Bacteria ; *Microbiota ; *Alphaproteobacteria ; Biofilms ; }, abstract = {Towels differ remarkably from other textile products in their fibre structure and usage, and microbial behaviours on towels remain underexplored. Thus, we evaluated biofilm formation on towels during use for 6 months in daily life and analysed its relationship with odour, dullness, and laundry habits. The towels exhibited odour and dullness after 2 months of use and biofilm structures were observed over the 6 months, especially in the ground warp part. Polysaccharides, proteins, nucleic acids, and viable counts on the towels increased over time. The microbiota was significantly different from that on human skin and clothing. Several species of Alphaproteobacteria were correlated with dullness intensity and the quantity of biofilm components. Therefore, bacterial species that specifically adapt to the towel fibre environment could form biofilms. Our results demonstrate bacterial diversity in textile products and suggest careful consideration of the textile fibre material, structure, and usage pattern to control bacterial communities.}, }
@article {pmid37163833, year = {2023}, author = {Ni, M and Zhao, Y and Pan, Y and Li, D and Huang, Y and Chen, Z and Li, L and Song, Z}, title = {A new insight in enhancing phosphate enrichment in biofilm process: Comparison of the key metabolic pathways in highly-efficient and dominant PAOs based on metagenomics.}, journal = {Journal of environmental management}, volume = {341}, number = {}, pages = {118114}, doi = {10.1016/j.jenvman.2023.118114}, pmid = {37163833}, issn = {1095-8630}, abstract = {The formation of dominant phosphate-accumulating organisms (PAOs) is essential for the high enrichment of phosphate in biofilm sequencing batch reactors (BSBR) for phosphorus recovery. The dominant PAOs in the biofilm process have not been isolated and purified, and the key metabolic pathways that promote the formation of dominant PAOs are still unclear. In this study, four strains of highly-efficient PAOs were obtained by an innovative isolation procedure. The relationship between the abundance of highly-efficient and dominant PAOs and the phosphate removal ability was compared. We found that the abundance of PAOs was positively correlated with the phosphate removal efficiency in vitro pure culture and complex biofilm process. Metagenomics analysis revealed that compared with highly-efficient PAOs cultured in vitro, dominant PAOs in biofilms had unique key metabolic pathways, F-ATPases and N-Acyl homoserine lactones (AHLs). F-ATPases are important for maintaining the proton motive force (PMF) required for the uptake of carbon sources by PAOs, and AHLs are participating in phosphate metabolism through quorum sensing (QS) mediated secretion of extracellular polymeric substance (EPS). The formation of dominant PAOs was promoted by optimizing carbon source uptake and phosphate metabolism. This study revealed that the difficult isolation of dominant PAOs was due to the AHLs-mediated QS, and we identified the key pathways regulating the formation of dominant PAOs in biofilms through genomics analysis. Our findings provide insights in enhancing phosphate enrichment in BSBR by modulating the components of microbial community under the low concentration of carbon source consumption.}, }
@article {pmid37162737, year = {2023}, author = {Byeon, CH and Wang, PC and Byeon, IL and Akbey, &#xdc;}, title = {Solution-state NMR assignment and secondary structure propensity of the full length and minimalistic-truncated prefibrillar monomeric form of biofilm forming functional amyloid FapC from Pseudomonas aeruginosa.}, journal = {Biomolecular NMR assignments}, volume = {}, number = {}, pages = {}, pmid = {37162737}, issn = {1874-270X}, abstract = {Functional bacterial amyloids provide structural scaffolding to bacterial biofilms. In contrast to the pathological amyloids, they have a role in vivo and are tightly regulated. Their presence is essential to the integrity of the bacterial communities surviving in biofilms and may cause serious health complications. Targeting amyloids in biofilms could be a novel approach to prevent chronic infections. However, structural information is very scarce on them in both soluble monomeric and insoluble fibrillar forms, hindering our molecular understanding and strategies to fight biofilm related diseases. Here, we present solution-state NMR assignment of 250 amino acid long biofilm-forming functional-amyloid FapC from Pseudomonas aeruginosa. We studied full-length (FL) and shorter minimalistic-truncated (L2R3C) FapC constructs without the signal-sequence that is required for secretion. 91% and 100% backbone NH resonance assignments for FL and L2R3C constructs, respectively, indicate that soluble monomeric FapC is predominantly disordered, with sizeable secondary structural propensities mostly as PP2 helices, but also as α-helices and β-sheets highlighting hotspots for fibrillation initiation interface. A shorter construct showing almost identical NMR chemical shifts highlights the promise of utilizing it for more demanding solid-state NMR studies that require methods to alleviate signal redundancy due to almost identical repeat units. This study provides key NMR resonance assignments for future structural studies of soluble, pre-fibrillar and fibrillar forms of FapC.}, }
@article {pmid37161489, year = {2023}, author = {Cheng, C and Jiang, T and Zhang, D and Wang, H and Fang, T and Li, C}, title = {Attachment characteristics and kinetics of biofilm formation by Staphylococcus aureus on ready-to-eat cooked beef contact surfaces.}, journal = {Journal of food science}, volume = {}, number = {}, pages = {}, doi = {10.1111/1750-3841.16592}, pmid = {37161489}, issn = {1750-3841}, abstract = {Staphylococcus aureus is a food-borne pathogen that quickly forms biofilm on meat contact surfaces and thus poses a serious threat to the safety of the meat industry. This study evaluated the attachment, survival, and growth of S. aureus biofilm with exposure to environmental factors in the meat industry by simulated ready-to-eat (RTE) cooked beef product contamination scenarios. The results indicated that the meat-borne S. aureus biofilm formation dynamic could be divided into four different phases: initial adhesion (4-12 h), exponential (12-24 h), slow growth (1-3 days), and stationary (3-7 days). Meat-borne S. aureus has strong adhesion and biofilm formation ability, and its biofilm exhibits persistence, high-intensity metabolic activity, aerotaxis, and strain heterogeneity. This study has also demonstrated that in the long-term existence of meat-borne S. aureus biofilm on stainless steel and plexiglass surfaces (>7 days, 7.2-8.8 log CFU/cm[2]), expose to RTE cooked beef products, may cause it to become high-risk contaminated food. Meat-borne S. aureus that forms a dense and rough concave-convex in the shape of biofilm architecture was observed by scanning electron microscopy, consisting of complex components and adhesion of living and dead cells. This was further confirmed by the meat-borne S. aureus biofilm on the stainless steel surface by attenuated total reflectance Fourier transformed infrared spectroscopy, and the dominant peaks in biofilm spectra were mainly associated with proteins, polysaccharides, amino acid residues, and phospholipids (>50%). These findings may help in the identification of the main sources of contamination within the meat industry and the subsequent establishment of strategies for biofilm prevention and removal. PRACTICAL APPLICATION: This study revealed the meat-borne S. aureus biofilm formation mechanism and found that it exhibited strong colonization and biofilm-forming ability, which can persist on the contact surfaces of ready-to-eat beef products. These initial findings could provide information on the behavior of meat-borne S. aureus biofilm attached to meat contact surfaces under conditions commonly encountered in meat environments, which help to support the determination of the main sources of contamination within the meat industry and the subsequent establishment of strategies for biofilm prevention and removal. It was also helpful in controlling biofilm contamination and improving meat safety to minimize it.}, }
@article {pmid37159227, year = {2023}, author = {Xu, D and Liu, J and Dai, H and Zhang, J and Hou, W and Wu, X and Zhao, Y}, title = {A premixed magnesium phosphate-based sealer with anti-biofilm ability for root canal filling.}, journal = {Journal of materials chemistry. B}, volume = {}, number = {}, pages = {}, doi = {10.1039/d3tb00375b}, pmid = {37159227}, issn = {2050-7518}, abstract = {The complex structure of the root canal system and microbial resistance increase the difficulty of endodontic treatment and the development of root canal sealers with good antibacterial and physicochemical properties is the key to treat refractory root canal infection. In the present study, a novel premixed root canal sealer containing trimagnesium phosphate (TMP), potassium dihydrogen phosphate (KH2PO4), magnesium oxide (MgO), zirconium oxide (ZrO2), and a bioactive oil phase was developed, and the physicochemical properties, radiopacity, antibacterial activity in vitro, anti-biofilm ability and cytotoxicity were investigated. MgO significantly improved the anti-biofilm ability and ZrO2 enhanced the radiopacity of the premixed sealer, and they had an obvious adverse effect on other properties. In addition, this sealer has advantages such as easy-to-use design, storabality, good sealing ability and biocompatibility. Therefore, this sealer has high potential for use in treating root canal infection.}, }
@article {pmid37158596, year = {2023}, author = {Gomez, S and Bureau, L and John, K and Chêne, EN and Débarre, D and Lecuyer, S}, title = {Substrate stiffness impacts early biofilm formation by modulating Pseudomonas aeruginosa twitching motility.}, journal = {eLife}, volume = {12}, number = {}, pages = {}, doi = {10.7554/eLife.81112}, pmid = {37158596}, issn = {2050-084X}, abstract = {Surface-associated lifestyles dominate in the bacterial world. Large multicellular assemblies, called biofilms, are essential to the survival of bacteria in harsh environments, and are closely linked to antibiotic resistance in pathogenic strains. Biofilms stem from the surface colonization of a wide variety of substrates encountered by bacteria, from living tissues to inert materials. Here, we demonstrate experimentally that the promiscuous opportunistic pathogen Pseudomonas aeruginosa explores substrates differently based on their rigidity, leading to striking variations in biofilm structure, exopolysaccharides (EPS) distribution, strain mixing during co-colonization and phenotypic expression. Using simple kinetic models, we show that these phenotypes arise through a mechanical interaction between the elasticity of the substrate and the type IV pilus (T4P) machinery, that mediates the surface-based motility called twitching. Together, our findings reveal a new role for substrate softness in the spatial organization of bacteria in complex microenvironments, with far-reaching consequences on efficient biofilm formation.}, }
@article {pmid37156358, year = {2023}, author = {O'Brien, EP and Mondal, K and Chen, CC and Hanley, L and Drummond, JL and Rockne, KJ}, title = {Relationships between composite roughness and Streptococcus mutans biofilm depth under shear in vitro.}, journal = {Journal of dentistry}, volume = {}, number = {}, pages = {104535}, doi = {10.1016/j.jdent.2023.104535}, pmid = {37156358}, issn = {1879-176X}, abstract = {OBJECTIVE: To investigate the effect of substrate, surface roughness, and hydraulic residence time (HRT) on Streptococcus mutans biofilms growing on dental composites under conditions relevant to the oral cavity.<br><br>METHODS: Dental composites were prepared with varying amounts of polishing and incubated in a CDC bioreactor with an approximate shear of 0.4 Pa. S. mutans biofilms developed in the bioreactors fed sucrose or glucose and at 10-h or 40-h HRT for one week. Biofilms were characterized by confocal laser microscopy (CLM). Composite surface roughness was characterized by optical profilometry, and pre- and post-incubation composite surface fine structure and elemental composition were determined using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS).<br><br>RESULTS: Polishing had a significant impact on surface roughness, varying by a factor of 15 between the polished samples and the unpolished control. S. mutans biofilms grew statistically significantly thicker on the unpolished composites. Biofilm thickness was greater at shorter 10-h HRT compared to 40-h HRT. In most cases, biofilm thickness was not statistically significantly greater in sucrose-fed bioreactors than in glucose-fed bioreactors. SEM-EDS analysis did not identify any significant change in elemental composition after aging.<br><br>CONCLUSIONS: Accurate characterization of oral cavity biofilms must consider shear forces and the use of techniques that minimize alteration of the biofilm structure. Under shear, surface smoothness is the most important factor determining S. mutans biofilm thickness followed by HRT, while sucrose presence did not result in significantly greater biofilm thickness.<br><br>CLINICAL SIGNIFICANCE: The obvious patterns of S. mutans growth along sub-micron scale grooving created by the polishing process suggested that initial biofilm attachment occurred in the shear-protected grooves. These results suggest that fine polishing may help prevent the initial formation of S. mutans biofilms compared to unpolished/coarse polished composites.}, }
@article {pmid37154695, year = {2023}, author = {de Lima, EJSP and Paz, WHP and Dávila Cardozo, NM and Boleti, APA and Silva, PSE and Mukoyama, LTH and da Silva, FMA and Costa, EV and Tavares, JF and Migliolo, L and Koolen, HHF}, title = {Anti-biofilm and anti-inflammatory active diterpene isolated from the fruit of Xylopia benthamii R.E.Fr.}, journal = {Natural product research}, volume = {}, number = {}, pages = {1-12}, doi = {10.1080/14786419.2023.2208357}, pmid = {37154695}, issn = {1478-6427}, abstract = {Xylopia benthamii (Annonaceae) is a plant with limited phytochemical and pharmacological evidence. Thus, using LC-MS/MS, we performed exploratory analyses of the fruit extract of X. benthamii, resulting in the tentative identification of alkaloids (1-7) and diterpenes (8-13). Through the application of chromatography techniques with the extract of X. benthamii, two kaurane diterpenes were isolated, xylopinic acid (9) and ent-15-oxo-kaur-16-en-19-oic acid (11). Their structures were established using spectroscopy (NMR 1D/2D) and mass spectrometry. The isolated compounds were submitted to anti-biofilm analysis against Acinetobacter baumannii, anti-neuroinflammatory and cytotoxic activity in BV-2 cells. Compound 11 (201.75 µM) inhibited 35% of bacterial biofilm formation and high anti-inflammatory activity in BV-2 (IC50 = 0.78 µM). In conclusion, the results demonstrated that compound 11 was characterized for the first time with pharmacological potential in the development of new alternatives for studies with neuroinflammatory diseases.}, }
@article {pmid37154227, year = {2023}, author = {He, Y and Wang, X and Zhang, C and Sun, J and Xu, J and Li, D}, title = {Near-Infrared Light-Mediated Cyclodextrin Metal-Organic Frameworks for Synergistic Antibacterial and Anti-Biofilm Therapies.}, journal = {Small (Weinheim an der Bergstrasse, Germany)}, volume = {}, number = {}, pages = {e2300199}, doi = {10.1002/smll.202300199}, pmid = {37154227}, issn = {1613-6829}, abstract = {Bacterial infections pose a significant threat to global public health; therefore, the development of novel therapeutics is urgently needed. Herein, a controllable antibacterial nanoplatform utilizing cyclodextrin metal-organic frameworks (CD-MOFs) as a template to synthesize ultrafine silver nanoparticles (Ag NPs) in their porous structure is constructed. Subsequently, polydopamine (PDA) is encapsulated on the CD-MOFs' surface via dopamine polymerization to enhance the water stability and enable hyperthermia capacity. The resulting Ag@MOF@PDA generates localized hyperthermia and gradually releases Ag[+] to achieve long-term photothermal-chemical bactericidal capability. The release rate of Ag[+] can be accelerated by NIR-mediated heating in a controllable manner, quickly reaching the effective concentration and reducing the frequency of medication to avoid potential toxicity. In vitro experiments demonstrate that the combined antibacterial strategy can not only effectively kill both gram-negative and gram-positive bacteria, but also directly eradicate mature biofilms. In vivo results confirm that both bacterial- and biofilm-infected wounds treated with a combination of Ag@MOF@PDA and laser exhibit satisfactory recovery with minimal toxicity, displaying a superior therapeutic effect compared to other groups. Together, the results warrant that the Ag@MOF@PDA realizes synergistic antibacterial capacity and controllable release of Ag[+] to combat bacterial and biofilm infections, providing a potential antibiotic-free alternative in the "post-antibiotic era."}, }
@article {pmid37154041, year = {2023}, author = {Yan, L and Zhang, S and Zhou, X and Tian, S}, title = {Anti-biofilm and bacteriostatic effects of three flavonoid compounds on Streptococcus mutans.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-12}, doi = {10.1080/08927014.2023.2209012}, pmid = {37154041}, issn = {1029-2454}, abstract = {Streptococcus mutans (S. mutans) is the main cariogenic pathogen associated with dental caries. Orientin-2''-O-β-L-galactoside, orientin and vitexin are natural flavonoids compound. In this study, the antibacterial ability of these flavonoids and their mechanisms in inhibiting S. mutans biofilm formation were investigated. Inhibition zone and 2-fold-dilution tests showed that these flavonoids exerted inhibitory effects on S. mutans. Phenol sulfuric acid method and lactate dehydrogenase (LDH) test revealed that they could reduce EPS formation and stimulate S. mutans to release LDH. Moreover, crystal violet and live/dead bacterial staining test showed that they inhibited biofilm formation. Finally, qRT-PCR test indicated that the down-regulated the transcription levels of spaP, srtA, brpA, gtfB and luxS genes of S. mutans. In conclusion, orientin-2''-O-β-L-galactoside, orientin and vitexin had antibacterial and anti-biofilm activities.}, }
@article {pmid37153739, year = {2023}, author = {Wu, X and Qi, M and Liu, C and Yang, Q and Li, S and Shi, F and Sun, X and Wang, L and Li, C and Dong, B}, title = {Near-infrared light-triggered nitric oxide nanocomposites for photodynamic/photothermal complementary therapy against periodontal biofilm in an animal model.}, journal = {Theranostics}, volume = {13}, number = {7}, pages = {2350-2367}, pmid = {37153739}, issn = {1838-7640}, mesh = {Animals ; Nitric Oxide ; Reactive Oxygen Species ; *Photochemotherapy/methods ; Biofilms ; *Nanocomposites ; Anti-Bacterial Agents/pharmacology ; Models, Animal ; *Complementary Therapies ; }, abstract = {Background: Periodontal disease, an oral disease that initiates with plaque biofilm infection, affects 10% of the global population. Due to the complexity of tooth root anatomy, biofilm resistance and antibiotic resistance, traditional mechanical debridement and antibiotic removal of biofilms are not ideal. Nitric oxide (NO) gas therapy and its multifunctional therapy are effective methods to clear biofilms. However, large and controlled delivery of NO gas molecules is currently a great challenge. Methods: The core-shell structure of Ag2S@ZIF-90/Arg/ICG was developed and characterized in detail. The ability of Ag2S@ZIF-90/Arg/ICG to produce heat, ROS and NO under 808 nm NIR excitation was detected by an infrared thermal camera, probes and Griess assay. In vitro anti-biofilm effects were evaluated by CFU, Dead/Live staining and MTT assays. Hematoxylin-eosin staining, Masson staining and immunofluorescence staining were used to analyze the therapeutic effects in vivo. Results: Antibacterial photothermal therapy (aPTT) and antibacterial photodynamic therapy (aPDT) could be excited by 808 nm NIR light, and the produced heat and ROS further triggered the release of NO gas molecules simultaneously. The antibiofilm effect had a 4-log reduction in vitro. The produced NO caused biofilm dispersion through the degradation of the c-di-AMP pathway and improved biofilm eradication performance. In addition, Ag2S@ZIF-90/Arg/ICG had the best therapeutic effect on periodontitis and NIR II imaging ability in vivo. Conclusions: We successfully prepared a novel nanocomposite with NO synergistic aPTT and aPDT. It had an outstanding therapeutic effect in treating deep tissue biofilm infection. This study not only enriches the research on compound therapy with NO gas therapy but also provides a new solution for other biofilm infection diseases.}, }
@article {pmid37153005, year = {2023}, author = {Teixeira, ABV and Valente, MLDC and Sessa, JPN and Gubitoso, B and Schiavon, MA and Dos Reis, AC}, title = {Adhesion of biofilm, surface characteristics, and mechanical properties of antimicrobial denture base resin.}, journal = {The journal of advanced prosthodontics}, volume = {15}, number = {2}, pages = {80-92}, pmid = {37153005}, issn = {2005-7806}, abstract = {PURPOSE: This study incorporated the nanomaterial, nanostructured silver vanadate decorated with silver nanoparticles (AgVO3), into heat-cured resin (HT) at concentrations of 2.5%, 5%, and 10% and compared the adhesion of multispecies biofilms, surface characteristics, and mechanical properties with conventional heat-cured (HT 0%) and printed resins.<br><br>MATERIALS AND METHODS: AgVO3 was incorporated in mass into HT powder. A denture base resin was used to obtain printed samples. Adhesion of a multispecies biofilm of Candida albicans, Candida glabrata, and Streptococcus mutans was evaluated by colony-forming units per milliliter (CFU/mL) and metabolic activity. Wettability, roughness, and scanning electron microscopy (SEM) were used to assess the physical characteristics of the surface. The mechanical properties of flexural strength and elastic modulus were tested.<br><br>RESULTS: HT 10%-AgVO3 showed efficacy against S. mutans; however, it favored C. albicans CFU/mL (P < .05). The printed resin showed a higher metabolically active biofilm than HT 0% (P < .05). There was no difference in wettability or roughness between groups (P > .05). Irregularities on the printed resin surface and pores in HT 5%-AgVO3 were observed by SEM. HT 0% showed the highest flexural strength, and the resins incorporated with AgVO3 had the highest elastic modulus (P < .05).<br><br>CONCLUSION: The incorporation of 10% AgVO3 into heat-cured resin provided antimicrobial activity against S. mutans in a multispecies biofilm did not affect the roughness or wettability but reduced flexural strength and increased elastic modulus. Printed resin showed higher irregularity, an active biofilm, and lower flexural strength and elastic modulus than heat-cured resin.}, }
@article {pmid37152853, year = {2023}, author = {Zargar, N and Parhizkar, A and Nasiri, MJ and Saedi, S}, title = {Antibacterial Efficacy of Polymer-Coated Ceramic Microparticles Loaded with a Modified Combination of Antibiotics on the Enterococcus faecalis Biofilm.}, journal = {Iranian endodontic journal}, volume = {18}, number = {2}, pages = {85-90}, pmid = {37152853}, issn = {2008-2746}, abstract = {INTRODUCTION: Nano-technology applied for the local delivery of different agents and/or drugs has made its path to endodontics. In the current study, the antibacterial efficacy of biopolymer-coated ceramic microparticles loaded with a modified combination of triple antibiotics, i.e. Penicillin G, Metronidazole and Ciprofloxacin (PMC), was evaluated against two strains of Enterococcus faecalis (E.faecalis); a standard clinical strain obtained from previously root-filled teeth with persistent periapical lesions, and compared to the most common antimicrobials used in endodontics.<br><br>METHODS AND MATERIALS: After synthesis of the polymer-coated microparticles loaded with antibiotics, the 21-day release of antibiotics were evaluated and a stock solution was produced using the maximum released amount of drugs and distilled water. The antibacterial activity of PMC, triple antibiotic paste (TAP), calcium hydroxide (CH), chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against two bacterial strains was determined using "Minimum Inhibitory Concentration" and "Agar Diffusion Test". Additionally, "Microtiter Plate Assay" was performed to assess anti-biofilm properties.<br><br>RESULTS: Minimum inhibitory concentration values reported for TAP and PMC were 1/256. PMC showed the maximum diameter of growth inhibition in both strains (33 mm and 35 mm), while CH had the minimum diameters (13 mm and13 mm). Based on microtiter plate assay, TAP showed higher biofilm formation than PMC. Biofilm formation was higher in the standard strain for PMC; however, NaOCl, CHX and CH completely inhibited biofilm formation.<br><br>CONCLUSIONS: Based on the findings of the present study, it could be concluded that PMC and TAP were the most effective medicaments against E.faecalis in its planktonic form; however, none could inhibit its biofilm formation. Further studies using larger sample size and "Confocal Scanning Laser Microscopy" are recommended.}, }
@article {pmid37152752, year = {2023}, author = {van Dun, SCJ and Verheul, M and Pijls, BGCW and van Prehn, J and Scheper, H and Galli, F and Nibbering, PH and de Boer, MGJ}, title = {Influence of surface characteristics of implant materials on MRSA biofilm formation and effects of antimicrobial treatment.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1145210}, pmid = {37152752}, issn = {1664-302X}, abstract = {INTRODUCTION: One of the main causes of treatment failure in bacterial prosthetic joint infections (PJI) is biofilm formation. The topography of the biofilm may be associated with susceptibility to antimicrobial treatment. The aims of this study were to assess differences in topography of biofilms on different implant materials and the correlation thereof with susceptibility to antimicrobial treatment.<br><br>METHODS: Methicillin-resistant Staphylococcus aureus (MRSA) 7-day mature biofilms were generated on disks made from titanium alloys (Ti-6Al-7Nb and Ti-6Al-4V), synthetic polymer and orthopedic bone cement, commonly used in implant surgery. The surface topography of these implant materials and the biofilms cultured on them was assessed using atomic force microscopy. This provided detailed images, as well as average roughness (Ra) and peak-to-valley roughness (Rt) values in nanometers, of the biofilm and the material surfaces. Bacterial counts within biofilms were assessed microbiologically. Antimicrobial treatment of biofilms was performed by 24-h exposure to the combination of rifampicin and ciprofloxacin in concentrations of 1-, 5- and 10-times the minimal bactericidal concentration (MBC). Finally, treatment-induced differences in bacterial loads and their correlation with biofilm surface parameters were assessed.<br><br>RESULTS: The biofilm surfaces on titanium alloys Ti-6Al-7Nb (Ra = 186 nm) and Ti-6Al-4V (Ra = 270 nm) were less rough than those of biofilms on silicone (Ra = 636 nm). The highest roughness was observed for biofilms on orthopedic bone cement with an Ra of 1,551 nm. Interestingly, the roughness parameters of the titanium alloys themselves were lower than the value for silicone, whereas the surface of the bone cement was the roughest. Treatment with 1- and 5-times the MBC of antibiotics resulted in inter-material differences in colony forming units (CFU) counts, ultimately showing comparable reductions of 2.4-3.0 log CFU/mL at the highest tested concentration. No significant differences in bacterial loads within MRSA biofilms were observed between the various implant materials, upon exposure to increasing concentrations of antibiotics.<br><br>DISCUSSION: The surface parameters of MRSA biofilms were determined by those of the implant materials on which they were formed. The antibiotic susceptibility of MRSA biofilms on the various tested implant materials did not differ, indicating that the efficacy of antibiotics was not affected by the roughness of the biofilm.}, }
@article {pmid37152721, year = {2023}, author = {Breser, ML and Tisera, L and Orellano, MS and Bohl, LP and Isaac, P and Bianco, I and Porporatto, C}, title = {Chitosan can improve antimicrobial treatment independently of bacterial lifestyle, biofilm biomass intensity and antibiotic resistance pattern in non-aureus staphylococci (NAS) isolated from bovine clinical mastitis.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1167693}, pmid = {37152721}, issn = {1664-302X}, abstract = {Bovine mastitis is the most frequent and costly disease that affects dairy cattle. Non-aureus staphylococci (NAS) are currently one of the main pathogens associated with difficult-to-treat intramammary infections. Biofilm is an important virulence factor that can protect bacteria against antimicrobial treatment and prevent their recognition by the host's immune system. Previously, we found that chronic mastitis isolates which were refractory to antibiotic therapy developed strong biofilm biomass. Now, we evaluated the influence of biofilm biomass intensity on the antibiotic resistance pattern in strong and weak biofilm-forming NAS isolates from clinical mastitis. We also assessed the effect of cloxacillin (Clx) and chitosan (Ch), either alone or in combination, on NAS isolates with different lifestyles and abilities to form biofilm. The antibiotic resistance pattern was not the same in strong and weak biofilm producers, and there was a significant association (p ≤ 0.01) between biofilm biomass intensity and antibiotic resistance. Bacterial viability assays showed that a similar antibiotic concentration was effective at killing both groups when they grew planktonically. In contrast, within biofilm the concentrations needed to eliminate strong producers were 16 to 128 times those needed for weak producers, and more than 1,000 times those required for planktonic cultures. Moreover, Ch alone or combined with Clx had significant antimicrobial activity, and represented an improvement over the activity of the antibiotic on its own, independently of the bacterial lifestyle, the biofilm biomass intensity or the antibiotic resistance pattern. In conclusion, the degree of protection conferred by biofilm against antibiotics appears to be associated with the intensity of its biomass, but treatment with Ch might be able to help counteract it. These findings suggest that bacterial biomass should be considered when designing new antimicrobial therapies aimed at reducing antibiotic concentrations while improving cure rates.}, }
@article {pmid37151214, year = {2023}, author = {Naaz, S and Sakib, N and Houserova, D and Badve, R and Crucello, A and Borchert, GM}, title = {Characterization of a novel sRNA contributing to biofilm formation in Salmonella enterica serovar Typhimurium.}, journal = {microPublication biology}, volume = {2023}, number = {}, pages = {}, pmid = {37151214}, issn = {2578-9430}, abstract = {Small RNAs (sRNAs) are short noncoding RNAs of ~50-200 nucleotides believed to primarily function in regulating crucial activities in bacteria during periods of cellular stress. This study examined the relevance of specific sRNAs on biofilm formation in nutrient starved Salmonella enterica serovar Typhimurium. Eight unique sRNAs were selected for deletion primarily based on their genomic location and/or putative targets. Quantitative and qualitative analyses confirm one of these, sRNA1186573, is required for efficient biofilm formation in S. enterica further highlighting the significance of sRNAs during Salmonella stress response.}, }
@article {pmid37150474, year = {2023}, author = {Premetis, GE and Georgakis, ND and Stathi, A and Labrou, NE}, title = {Metaviromics analysis of marine biofilm reveals a glycoside hydrolase endolysin with high specificity towards Acinetobacter baumannii.}, journal = {Biochimica et biophysica acta. Proteins and proteomics}, volume = {}, number = {}, pages = {140918}, doi = {10.1016/j.bbapap.2023.140918}, pmid = {37150474}, issn = {1878-1454}, abstract = {Multidrug-resistant (MDR) bacteria are a growing threat to the public health. Among them, the Gram-negative Acinetobacter baumannii is considered today as the most dangerous MDR pathogen. Phage-derived endolysins are peptidoglycan (PG) hydrolytic enzymes that can function as effective tools in the fight against MDR bacteria. In the present work, the viral diversity of a marine environmental sample (biofilm), formed near an industrial zone, was mined for the identification of a putative endolysin (AbLys2) that belongs to the glycoside hydrolase family 24 (GH24) (EC 3.2.1.17). The coding sequence of AbLys2 was cloned and expressed in E. coli. The lytic activity and specificity of the recombinant enzyme were evaluated against suspensions of a range of Gram-positive and Gram-negative human pathogens using turbidity assays. AbLys2 displayed enhanced selectivity towards A. baumannii cells, compared to other bacteria. Kinetics analysis was carried out to characterize the dependence of its lytic activity on pH and showed that the enzyme exhibits its maximal activity at pH 5.5. Thermostability analysis showed that AbLys2 displays melting temperature Tm 47.1 °C. Florescence microscopy and cell viability assays established that AbLys2 is active towards live cultures of A. baumannii cells with an inhibitory concentration IC50 3.41 ± 0.09 μM. Molecular modeling allowed the prediction of important amino acid residues involved in catalysis. The results of the present study suggest that AbLys2 provides efficient lytic and antimicrobial activity towards A. baumannii cells and therefore is a promising new antimicrobial against this pathogen.}, }
@article {pmid37150370, year = {2023}, author = {Lu, T and Han, X and Wang, H and Zhang, Z and Lu, S}, title = {Multi-functional bio-film based on sisal cellulose nanofibres and carboxymethyl chitosan with flame retardancy, water resistance, and self-cleaning for fire alarm sensors.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {124740}, doi = {10.1016/j.ijbiomac.2023.124740}, pmid = {37150370}, issn = {1879-0003}, abstract = {Flexible and environmentally friendly bio-based films have attracted significant attention as next-generation fire-responsive sensors. However, the low structural stability, durability, and flame retardancy of pure bio-based films limit their application in outdoor and extreme environments. Here, we report the design of a sustainable bio-based composite film assembled from carboxymethyl-modified sisal fibre microcrystals (C-MSF), carboxymethyl chitosan (CMC), graphene nanosheets (GNs), phytic acid (PA), and trivalent iron ions (Fe[3+]). Cross-linking between Fe[3+] and the C-MSF/CMC matrix and the formation of PA-Fe[3+] complexes on the surface of the film imparted excellent mechanical properties, chemical stability, self-cleaning ability, and flame retardancy to the bio-film. Furthermore, the bio-film produced a reversible and sensitive response to temperature at 55.3-214.1 °C, and a fire alarm system made from the bio-film had a fire-response time of 4.6 s. In addition, the char layer of the bio-film retained a stable cyclic response to temperature, enabling it to serve as a fire resurgence sensor with a response time of 2.3 s and recovery time of 11.2 s. This work provides a simple pathway for the fabrication of self-cleaning, flame retardant, and water-resistant bio-films that can be assembled into fire alarm systems for the real-time monitoring of fire accidents and resurgence.}, }
@article {pmid37150060, year = {2023}, author = {Laconi, A and Tolosi, R and Drigo, I and Bano, L and Piccirillo, A}, title = {Association between ability to form biofilm and virulence factors of poultry extra-intestinal Campylobacter jejuni and Campylobacter coli.}, journal = {Veterinary microbiology}, volume = {282}, number = {}, pages = {109770}, doi = {10.1016/j.vetmic.2023.109770}, pmid = {37150060}, issn = {1873-2542}, abstract = {Campylobacter species are known to be able to produce biofilm, which represents an ideal protective environment for the maintenance of such fragile bacteria. Since the genetic mechanisms promoting biofilm formation are still poorly understood, in this study we assessed the ability of C. jejuni (n = 7) and C. coli (n = 3) strains isolated from diseased poultry, and previously characterized by whole genome sequencing, to form biofilm. The in vitro analyses were carried out by using a microtiter based protocol including biofilm culturing and fixation, staining with crystal violet, and measurement of the optical density (OD570). The ability to form biofilm was categorized into four classes (no, weak, moderate, and strong producers). Potential correlations between OD570 and the presence/absence of virulence determinants were examined. The C. jejuni were classified as no (n = 3), weak (n = 2), and moderate (n = 2) biofilm producers; however, all possessed genes involved in chemotaxis, adhesion, and invasion to the host cells. No genes present exclusively in biofilm producers or in non-biofilm producers were identified. All C. coli were classified as weak producers and showed a similar set of virulence genes between each other. A trend of increased mean OD570 was observed in the presence of flaA and maf7 genes. No association between biofilm production classes and the explanatory variables considered was observed. The results of this study suggest that further investigations are needed to better identify and characterize the genetic determinants involved in extra-intestinal Campylobacter biofilm formation.}, }
@article {pmid37149027, year = {2023}, author = {Bao, HX and Wang, HL and Wang, ST and Sun, YL and Zhang, XN and Cheng, HY and Qian, ZM and Wang, AJ}, title = {Response of sulfur-metabolizing biofilm to external sulfide in element sulfur-based dentification packed-bed reactor.}, journal = {Environmental research}, volume = {}, number = {}, pages = {116061}, doi = {10.1016/j.envres.2023.116061}, pmid = {37149027}, issn = {1096-0953}, abstract = {Dosing sulfide into the sulfur-packed-bed (S[0]PB) has great potential to enhance the denitrification efficiency by providing compensatory electron donors, however, the response of sulfur-metabolizing biofilm to various sulfide dosages has never been investigated. In this study, the S[0]PB reactor was carried out with increasing sulfide dosages by 3.6 kg/m[3]/d, presenting a decreasing effluent nitrate from 14.2 to 2.7 mg N/L with accelerated denitrification efficiency (k: 0.04 to 0.27). However, 6.5 mg N/L of nitrite accumulated when the sulfide dosage exceeded 0.9 kg/m[3]/d (optimum value). The increasing electron export contribution of sulfide as maximum as 85.5% illustrated its competition with the in-situ sulfur. Meanwhile, over-dosing sulfide caused serious biofilm expulsion with significant decreases in the total biomass, live cell population, and ATP by 90.2%, 86.7%, and 54.8%, respectively. This study verified the capacity of dosing sulfide to improve the denitrification efficiency in S[0]PB but alerted the negative effect by exceeded dosing.}, }
@article {pmid37148923, year = {2023}, author = {Shi, C and Zheng, L and Lu, Z and Zhang, X and Bie, X}, title = {The global regulator SpoVG regulates Listeria monocytogenes biofilm formation.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106144}, doi = {10.1016/j.micpath.2023.106144}, pmid = {37148923}, issn = {1096-1208}, abstract = {Biofilms provide a suitable environment for L. monocytogenes and are the cause of enormous risks in the food industry. SpoVG is a global regulatory factor that plays a vital role in physiological activity of L. monocytogenes. We constructed spoVG mutant strains to investigate the effects of these mutants on L. monocytogenes biofilms. The results show that L. monocytogenes biofilm formation was decreased by 40%. Furthermore, we measured biofilm related phenotypes to study the regulation of SpoVG. The motility capacity of L. monocytogenes was found to decrease after the deletion of spoVG. The cell surface properties changed in the spoVG mutant strains, with an increase in both the cell surface hydrophobicity and the auto-aggregation capacity after spoVG deletion. SpoVG mutant strains were found to be more sensitive to antibiotics, and had a reduced tolerance to inappropriate pH, salt stress and low temperature. The RT-qPCR results showed that SpoVG effectively regulated the expression of genes related to quorum sensing, flagella, virulence and stress factors. These findings suggest that spoVG has potential as a target to decrease biofilm formation and control L. monocytogenes contamination in the food industry.}, }
@article {pmid37148370, year = {2023}, author = {Lv, Z and Yin, S and Jiang, K and Wang, W and Luan, Y and Wu, S and Shi, J and Li, Z and Ma, X and Wang, Z and Yan, H}, title = {The whole-cell proteome shows the characteristics of macrolides-resistant Bordetella pertussis in China linked to the biofilm formation.}, journal = {Archives of microbiology}, volume = {205}, number = {6}, pages = {219}, pmid = {37148370}, issn = {1432-072X}, mesh = {Humans ; *Bordetella pertussis/genetics ; Macrolides/pharmacology ; *Whooping Cough ; Proteome ; Proteomics ; Anti-Bacterial Agents/pharmacology ; }, abstract = {The macrolides-resistant Bordetella pertussis (MR-Bp) isolates in China evolved from the ptxP1/fhaB3 allele and rapidly became predominant, suggestive of an adaptive transmission ability. This was different from the global prevalent ptxP3 strains, in which MR-Bp was rarely reported. The study aimed to determine the underlying mechanism responsible for fitness and resistance in these two strains. We identify proteomic differences between ptxP1/fhaB3 and ptxP3/fhaB1 strains using tandem mass tag (TMT)-based proteomics. We then performed in-depth bioinformatic analysis to determine differentially expressed genes (DEGs), followed by gene ontology (GO), and protein-protein interaction (PPI) network analysis. Further parallel reaction monitoring (PRM) analysis confirmed the expression of four target proteins. Finally, the crystal violet method was used to determine biofilm-forming ability. The results showed that the main significantly different proteins between the two represent isolates were related to biofilm formation. Furthermore, we have confirmed that ptxP1/fhaB3 showed hyperbiofilm formation in comparison with ptxP3/fhaB1. It is suggested that the resistance and adaptability of ptxP1/fhaB3 strains may be related to the formation of biofilm through proteomics. In a word, we determined the significantly different proteins between the ptxP1/fhaB3 and ptxP3/fhaB1 strains through whole-cell proteome, which were related to biofilm formation.}, }
@article {pmid37146493, year = {2023}, author = {Masoudi-Sobhanzadeh, Y and Pourseif, MM and Khalili-Sani, A and Jafari, B and Salemi, A and Omidi, Y}, title = {Deciphering anti-biofilm property of Arthrospira platensis-origin peptides against Staphylococcusaureus.}, journal = {Computers in biology and medicine}, volume = {160}, number = {}, pages = {106975}, doi = {10.1016/j.compbiomed.2023.106975}, pmid = {37146493}, issn = {1879-0534}, abstract = {Arthrospira platensis is a valuable natural health supplement consisting of various types of vitamins, dietary minerals, and antioxidants. Although different studies have been conducted to explore the hidden benefits of this bacterium, its antimicrobial property has been poorly understood. To decipher this important feature, here, we extended our recently introduced optimization algorithm (Trader) for aligning amino acid sequences associated with the antimicrobial peptides (AMPs) of Staphylococcus aureus and A.platensis. As a result, similar amino acid sequences were identified, and several candidate peptides were generated accordingly. The obtained peptides were then filtered based on their potential biochemical and biophysical properties, and their 3D structures were simulated based on homology modeling techniques. Next, to investigate how the generated peptides can interact with S. aureus proteins (i.e., heptameric state of the hly and homodimeric form of the arsB), molecular docking approaches were used. The results indicated that four peptides included better molecular interactions relative to the other generated ones in terms of the number/average length of hydrogen bonds and hydrophobic interactions. Based on the outcomes, it can be concluded that the antimicrobial property of A.platensis might be associated with its capability in disturbing the membrane of pathogens and their functions.}, }
@article {pmid37144188, year = {2023}, author = {Adhikari, S and Sharma Regmi, R and Sapkota, S and Khadka, S and Patel, N and Gurung, S and Thapa, D and Bhattarai, P and Sapkota, P and Devkota, R and Ghimire, A and Rijal, KR}, title = {Multidrug resistance, biofilm formation and detection of bla CTX-M and bla VIM genes in E. coli and Salmonella isolates from chutney served at the street-food stalls of Bharatpur, Nepal.}, journal = {Heliyon}, volume = {9}, number = {5}, pages = {e15739}, pmid = {37144188}, issn = {2405-8440}, abstract = {Antimicrobial resistance (AMR) amid the bacteria found in ready-to-eat foods is a grave concern today warranting an immediate intervention. The current study was undertaken to explore the status of AMR in E. coli and Salmonella species in ready-to-eat Chutney samples (n = 150) served at the street food stalls in Bharatpur, Nepal, with a major focus on detecting extended-spectrum β-lactamase (ESBL) and metallo β-lactamase (MBL) genes along with biofilm formation. Average viable counts, coliform counts, and Salmonella Shigella counts were 1.33 × 10[6]±141481.4, 1.83 × 10[5]±91303.6, and 1.24 × 10[5]±63933.19 respectively. Out of 150 samples, 41 (27.33%) harbored E. coli, of which 7 were E. coli O157:H7; whereas Salmonella spp. were found in 31 (20.67%) samples. Bacterial contamination of Chutney by E. coli and Salmonella and ESBL-production were both found significantly affected by different sources of water used, personal hygiene and literacy rate of the vendors as well as by the type of cleaning materials used to wash knives and chopping boards (P < 0.05). Antibiotic susceptibility testing revealed that imipenem was the most effective drug against both types of bacterial isolates. Additionally, 14 (45.16%) Salmonella isolates and 27 (65.85%) E. coli isolates were found to be multi-drug resistant (MDR). Total ESBL (bla CTX-M) producers reported were 4 (12.90%) Salmonella spp. and 9 (21.95%) E. coli. Only 1 (3.23%) Salmonella spp. and 2 (4.88%) E. coli isolates were bla VIM gene carriers. Dissemination of knowledge of personal hygiene amongst the street vendors and consumer awareness regarding ready-to-eat foods are crucial factors that can be suggested to curtail the emergence and transmission of food-borne pathogens.}, }
@article {pmid37142893, year = {2023}, author = {Paul, P and Sarkar, S and Dastidar, DG and Shukla, A and Das, S and Chatterjee, S and Chakraborty, P and Tribedi, P}, title = {1, 4-naphthoquinone efficiently facilitates the disintegration of pre-existing biofilm of Staphylococcus aureus through eDNA intercalation.}, journal = {Folia microbiologica}, volume = {}, number = {}, pages = {}, pmid = {37142893}, issn = {1874-9356}, abstract = {1, 4-naphthoquinone, a plant-based quinone derivative, has gained much attention for its effectiveness against several biofilm-linked diseases. The biofilm inhibitory effect of 1, 4-naphthoquinone against Staphylococcus aureus has already been reported in our previous study. We observed that the extracellular DNA (eDNA) could play an important role in holding the structural integrity of the biofilm. Hence, in this study, efforts have been directed to examine the possible interactions between 1, 4-naphthoquinone and DNA. An in silico analysis indicated that 1, 4-naphthoquinone could interact with DNA through intercalation. To validate the same, UV-Vis spectrophotometric analysis was performed in which a hypochromic shift was observed when the said molecule was titrated with calf-thymus DNA (CT-DNA). Thermal denaturation studies revealed a change of 8℃ in the melting temperature (Tm) of CT-DNA when complexed with 1, 4-naphthoquinone. The isothermal calorimetric titration (ITC) assay revealed a spontaneous intercalation between CT-DNA and 1, 4-naphthoquinone with a binding constant of 0.95 ± 0.12 × 10[8]. Furthermore, DNA was run through an agarose gel electrophoresis with a fixed concentration of ethidium bromide and increasing concentrations of 1, 4-naphthoquinone. The result showed that the intensity of ethidium bromide-stained DNA got reduced concomitantly with the gradual increase of 1, 4-naphthoquinone suggesting its intercalating nature. To gain further confidence, the pre-existing biofilm was challenged with ethidium bromide wherein we observed that it could also show biofilm disintegration. Therefore, the results suggested that 1, 4-naphthoquinone could exhibit disintegration of the pre-existing biofilm of Staphylococcus aureus through eDNA intercalation.}, }
@article {pmid37141849, year = {2023}, author = {Wang, J and Wang, Y and Lou, H and Wang, W}, title = {AlgU controls environmental stress adaptation, biofilm formation, motility, pyochelin synthesis and antagonism potential in Pseudomonas protegens SN15-2.}, journal = {Microbiological research}, volume = {272}, number = {}, pages = {127396}, doi = {10.1016/j.micres.2023.127396}, pmid = {37141849}, issn = {1618-0623}, abstract = {Pseudomonas protegens is a typical plant-growth-promoting rhizobacterium that can serve as an agricultural biocontrol agent. The extracytoplasmic function (ECF) sigma factor AlgU is a global transcription regulator controlling stress adaption and virulence in Pseudomonas aeruginosa and Pseudomonas syringae. Meanwhile, the regulatory role of AlgU in the biocontrol ability of P.protegens has been poorly studied. In this study, deletion mutations of algU and its antagonist coding gene mucA were constructed to investigate the function of AlgU in P.protegens SN15-2 via phenotypic experiment and transcriptome sequencing analysis. On the basis of phenotypic analyses, it was concluded that the AlgU whose transcription was induced by osmotic stress and oxidative stress positively regulated biofilm formation and tolerance towards osmotic, heat, and oxidation stresses, while it negatively regulated motility, pyochelin synthesis, and the ability to inhibit pathogens. On the basis of the RNA-seq analysis, compared to the wild-type strain, 12 genes were significantly upregulated and 77 genes were significantly downregulated in ΔalgU, while 407 genes were significantly upregulated and 279 genes were significantly downregulated in ΔmucA, indicating the involvement of AlgU in several cellular processes, mainly related to resistance, carbohydrate metabolism, membrane formation, alginate production, the type VI secretion system, flagella motility and pyochelin production. Our findings provide insights into the important role of AlgU of P.protegens in biocontrol, which is of value in improving the biocontrol ability of P.protegens.}, }
@article {pmid37141712, year = {2023}, author = {Yan, H and Zhang, Q and Wang, Y and Cui, X and Liu, Y and Yu, Z and Xu, S and Ruan, R}, title = {Rice straw as microalgal biofilm bio-carrier: Effects of indigenous microorganisms on rice straw and microalgal biomass production.}, journal = {Journal of environmental management}, volume = {341}, number = {}, pages = {118075}, doi = {10.1016/j.jenvman.2023.118075}, pmid = {37141712}, issn = {1095-8630}, abstract = {Microalgal biofilm cultivation is a promising method for efficient microalgae production. However, expensive, difficult-to-obtain and non-durable carriers hinder its up-scaling. This study adopted both sterilized and unsterilized rice straw (RS) as a carrier for the development of microalgal biofilm, with polymethyl methacrylate as control. The biomass production and chemical composition of Chlorella sorokiniana, as well as the microbial community composition during cultivation were examined. The physicochemical properties of RS before and after utilized as carrier were investigated. The biomass productivity of unsterilized RS biofilm exceeded that of suspended culture by 4.85 g m[-2]·d[-1]. The indigenous microorganisms, mainly fungus, could effectively fixed microalgae to the bio-carrier and enhance its biomass production. They could also degrade RS into dissolved matters for microalgal utilization, leading to the physicochemical properties change of RS in the direction which favored its energy conversion. This study showed that RS can be used effectively as a microalgal biofilm carrier, thus presenting a new possibility for the recycling of rice straw.}, }
@article {pmid37140860, year = {2023}, author = {Díaz, O and González, E and Vera, L and Fernández, LJ and Díaz-Marrero, AR and Fernández, JJ}, title = {Recirculating packed-bed biofilm photobioreactor combined with membrane ultrafiltration as advanced wastewater treatment.}, journal = {Environmental science and pollution research international}, volume = {}, number = {}, pages = {}, pmid = {37140860}, issn = {1614-7499}, abstract = {Packed-bed biofilm photobioreactor combined with ultrafiltration membrane was investigated for intensifying the process for secondary wastewater effluent treatment. Cylindrical glass carriers were used as supporting material for the microalgal-bacterial biofilm, which developed from indigenous microbial consortium. Glass carriers allowed adequate growth of the biofilm with limited suspended biomass. Stable operation was achieved after a start-up period of 1000 h, where supernatant biopolymer clusters were minimized and complete nitrification was observed. After that time, biomass productivity was 54 ± 18 mg·L[-1]·day[-1]. Green microalgae Tetradesmus obliquus and several strains of heterotrophic nitrification-aerobic denitrification bacteria and fungi were identified. Combined process exhibited COD, nitrogen and phosphorus removal rates of 56 ± 5%, 12 ± 2% and 20 ± 6%, respectively. Membrane fouling was mainly caused by biofilm formation, which was not effectively mitigated by air-scouring aided backwashing.}, }
@article {pmid37140461, year = {2023}, author = {Jiang, X and Kang, R and Yu, T and Jiang, X and Chen, H and Zhang, Y and Li, Y and Wang, H}, title = {Cinnamaldehyde Targets the LytTR DNA-Binding Domain of the Response Regulator AgrA to Attenuate Biofilm Formation of Listeria monocytogenes.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0030023}, doi = {10.1128/spectrum.00300-23}, pmid = {37140461}, issn = {2165-0497}, abstract = {The Agr quorum sensing (QS) system is known to contribute to biofilm formation in Listeria monocytogenes. Cinnamaldehyde, a natural food preservative, is considered an inhibitor of Agr-mediated QS in L. monocytogenes. However, the exact mechanism by which cinnamaldehyde acts on Agr remains unclear. In this study, we assessed the effects of cinnamaldehyde on the histidine kinase AgrC and the response regulator AgrA in the Agr system. AgrC kinase activity was not influenced by cinnamaldehyde, and binding between AgrC and cinnamaldehyde was not observed when microscale thermophoresis (MST) was performed, indicating that AgrC was not the target of cinnamaldehyde. AgrA is specifically bound to the agr promoter (P2) to activate the transcription of the Agr system. However, AgrA-P2 binding was prevented by cinnamaldehyde. The interaction between cinnamaldehyde and AgrA was further confirmed with MST. Two conserved amino acids, Asn-178 and Arg-179, located in the LytTR DNA-binding domain of AgrA, were identified as the key sites for cinnamaldehyde-AgrA binding by alanine mutagenesis and MST. Coincidentally, Asn-178 was also involved in the AgrA-P2 interaction. Taken together, these results suggest that cinnamaldehyde acts as a competitive inhibitor of AgrA in AgrA-P2 binding, which leads to suppressed transcription of the Agr system and reduced biofilm formation in L. monocytogenes. IMPORTANCE Listeria monocytogenes can form biofilms on various food contact surfaces, posing a serious threat to food safety. Biofilm formation of L. monocytogenes is positively regulated by the Agr quorum sensing system. Thus, an alternative strategy for controlling L. monocytogenes biofilms is interfering with the Agr system. Cinnamaldehyde is considered an inhibitor of the L. monocytogenes Agr system; however, its exact mechanism of action is still unclear. Here, we found that AgrA (response regulator), rather than AgrC (histidine kinase), was the target of cinnamaldehyde. The conserved Asn-178 in the LytTR DNA-binding domain of AgrA was involved in cinnamaldehyde-AgrA and AgrA-P2 binding. Therefore, the occupation of Asn-178 by cinnamaldehyde suppressed transcription of the Agr system and reduced biofilm formation in L. monocytogenes. Our findings could provide a better understanding of the mechanism by which cinnamaldehyde inhibits L. monocytogenes biofilm formation.}, }
@article {pmid37140383, year = {2023}, author = {Ding, Y and Liu, G and Liu, S and Li, X and Xu, K and Liu, P and Cai, K}, title = {A multi-function hydrogel-coating engineered implant for rescuing biofilm infection and boosting osseointegration by macrophage-related immunomodulation.}, journal = {Advanced healthcare materials}, volume = {}, number = {}, pages = {e2300722}, doi = {10.1002/adhm.202300722}, pmid = {37140383}, issn = {2192-2659}, abstract = {Incurable bacterial infections, impenetrable microbial biofilm and dysregulated immune microenvironments are among the most intractable threats for the treatment of implant-associated infections (IAIs). Innovative methodologies combined with reactive oxygen species (ROS) scavenging suppress the oxidative stress damage and promote macrophage polarization to M2 phenotype may be ideal for remodeling implant-infected bone tissue. Herein, a functionalization strategy for doping Tannic acid-D-Tyrosine nanoparticles (TA-D-Tyr NPs) with photothermal profile into the hydrogel coating composed of konjac gum and gelatin on the titanium (Ti) surface w as accurately constructed, named as Ti-G-TA-D-Tyr sample. The prepared hydrogel coating exhibited excellent properties of eliminating biofilm and killing planktonic bacteria, which w as based on increasing susceptibility to bacteria by the photothermal transduction effect of TA-D-Tyr NPs, biofilm-dissipation effect of D-Tyr, as well as the bactericidal effect of TA. In addition, Ti-G-TA-Tyr sample h ad effectively alleviated proinflammatory responses by scavenging intracellular excessive ROS and guiding macrophages polarization towards M2. More interesting, conditioned medium from macrophage indicated that paracrine w as conducive to osteogenic proliferation and differentiation of mesenchymal stem cells. Results from Rat model of femur infection in vivo demonstrated that the modified Ti implant significantly eliminated the residual bacteria, relieved inflammation, mediated macrophage polarization, and accelerated osseointegration. Altogether, this study exhibited a new perspective for the development of advanced functional implant with great application potential in bone tissue regeneration and repair. This article is protected by copyright. All rights reserved.}, }
@article {pmid37139491, year = {2023}, author = {Bari, AK and Belalekar, TS and Poojary, A and Rohra, S}, title = {Combination drug strategies for biofilm eradication using synthetic and natural agents in KAPE pathogens.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1155699}, pmid = {37139491}, issn = {2235-2988}, mesh = {*Biofilms ; *Anti-Bacterial Agents/pharmacology ; Bacteria ; Tobramycin/pharmacology ; Chlorhexidine ; }, abstract = {Antibiotic resistance is a global threat caused by factors such as overuse of antibiotics, lack of awareness, development of biofilms etc. World Health Organization released a list of global priority pathogens which consisted of 12 species of bacteria categorized as expressing critical, high and medium resistance. Several Gram-negative and Gram-positive species are known to cause wide varieties of infections and have become multidrug or extremely drug resistant. Pathogens causing infections associated with invasive medical devices are biofilm producers and hence their treatment becomes difficult due to a structurally stable matrix which prevents antibiotics from penetrating the biofilm and thereby showing its effects. Factors contributing to tolerance are inhibition of penetration, restricted growth and activation of biofilm genes. Combination drug therapies has also shown potential to eradicate biofilm infections. A combination of inhaled Fosfomycin/tobramycin antibiotic strategy has been effective against Gram-negative as well as Gram positive organisms. Along with antibiotics, use of natural or synthetic adjuvants shows promising effects to treat biofilm infections. Fluroquinolone activity on biofilms is disrupted by low oxygen tension in the matrix, a strategy known as hyperbaric oxygen treatment that can enhance efficacy of antibiotics if well optimized. Adjuvants such as Ethylenediaminetetraacetic acid (EDTA), Sodium Dodecyl Sulphate (SDS) and chlorhexidine act by killing non-growing microbial cells aggregated on the inner layer of the biofilm. This review aims to list down current combination therapies used against Gram-negative and Gram-positive biofilm forming pathogens and brief about comparison of combination drugs and their efficacies.}, }
@article {pmid37138664, year = {2023}, author = {Sun, Y and Chen, H and Xu, M and He, L and Mao, H and Yang, S and Qiao, X and Yang, D}, title = {Exopolysaccharides metabolism and cariogenesis of Streptococcus mutans biofilm regulated by antisense vicK RNA.}, journal = {Journal of oral microbiology}, volume = {15}, number = {1}, pages = {2204250}, pmid = {37138664}, issn = {2000-2297}, abstract = {BACKGROUND: Streptococcus mutans (S. mutans) is a pivotal cariogenic pathogen contributing to its multiple virulence factors, one of which is synthesizing exopolysaccharides (EPS). VicK, a sensor histidine kinase, plays a major role in regulating genes associated with EPS synthesis and adhesion. Here we first identified an antisense vicK RNA (ASvicK) bound with vicK into double-stranded RNA (dsRNA).<br><br>OBJECTIVE: This study aims to investigate the effect and mechanism of ASvicK in the EPS metabolism and cariogenesis of S. mutans.<br><br>METHODS: The phenotypes of biofilm were detected by scanning electron microscopy (SEM), gas chromatography-mass spectrometery (GC-MS) , gel permeation chromatography (GPC) , transcriptome analysis and Western blot. Co-immunoprecipitation (Co-ip) assay and enzyme activity experiment were adopted to investigate the mechanism of ASvicK regulation. Caries animal models were developed to study the relationship between ASvicK and cariogenicity of S. mutans.<br><br>RESULTS: Overexpression of ASvicK can inhibit the growth of biofilm, reduce the production of EPS and alter genes and protein related to EPS metabolism. ASvicK can adsorb RNase III to regulate vicK and affect the cariogenicity of S. mutans.<br><br>CONCLUSIONS: ASvicK regulates vicK at the transcriptional and post-transcriptional levels, effectively inhibits EPS synthesis and biofilm formation and reduces its cariogenicity in vivo.}, }
@article {pmid37138622, year = {2023}, author = {Zhou, Y and Jiang, D and Yao, X and Luo, Y and Yang, Z and Ren, M and Zhang, G and Yu, Y and Lu, A and Wang, Y}, title = {Pan-genome wide association study of Glaesserella parasuis highlights genes associated with virulence and biofilm formation.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1160433}, pmid = {37138622}, issn = {1664-302X}, abstract = {Glaesserella parasuis is a gram-negative bacterium that causes fibrotic polyserositis and arthritis in pig, significantly affecting the pig industry. The pan-genome of G. parasuis is open. As the number of genes increases, the core and accessory genomes may show more pronounced differences. The genes associated with virulence and biofilm formation are also still unclear due to the diversity of G. parasuis. Therefore, we have applied a pan-genome-wide association study (Pan-GWAS) to 121 strains G. parasuis. Our analysis revealed that the core genome consists of 1,133 genes associated with the cytoskeleton, virulence, and basic biological processes. The accessory genome is highly variable and is a major cause of genetic diversity in G. parasuis. Furthermore, two biologically important traits (virulence, biofilm formation) of G. parasuis were studied via pan-GWAS to search for genes associated with the traits. A total of 142 genes were associated with strong virulence traits. By affecting metabolic pathways and capturing the host nutrients, these genes are involved in signal pathways and virulence factors, which are beneficial for bacterial survival and biofilm formation. This research lays the foundation for further studies on virulence and biofilm formation and provides potential new drug and vaccine targets against G. parasuis.}, }
@article {pmid37138171, year = {2023}, author = {Gao, M and Xu, B and Huang, Y and Cao, J and Yang, L and Liu, X and Djumaev, A and Wu, D and Shoxiddinova, M and Cai, X and Tojiyev, B and Zheng, H and Li, X and Normurodova, K and Liu, H and Li, R}, title = {Nano-enabled Quenching of Bacterial Communications for the Prevention of Biofilm Formation.}, journal = {Angewandte Chemie (International ed. in English)}, volume = {}, number = {}, pages = {e202305485}, doi = {10.1002/anie.202305485}, pmid = {37138171}, issn = {1521-3773}, abstract = {Biofilm formation is a major threat to industry, the environment and human health. While killing of embedded microbes in biofilms may inevitably lead to the evolution of antimicrobial resistance (AMR), catalytic quenching of bacterial communications by lactonase is a promising antifouling approach. Given the shortcomings of protein enzymes, it's attractive to engineer synthetic materials to mimic the activity of lactonase. Herein, an efficient lactonase-like Zn-Nx-C nanomaterial was synthesized by tuning the coordination environment around zinc atoms to mimic the active domain of lactonase for catalytical interception of bacterial communications in biofilm formation. The Zn-Nx-C material could selectively catalyze 77.5% hydrolysis of N-acylated-L-homoserine lactone (AHL), a critical bacterial quorum sensing (QS) signal in biofilm construction. Consequently, AHL degradation downregulated the expression of QS-related genes in antibiotic resistant bacteria and significantly prevented biofilm formation. As a proof of concept, Zn-Nx-C-coated iron plates prevented 80.3% biofouling after a month exposure in river. Overall, our study provides a nano-enabled contactless antifouling insight to avoid AMR evolutions by engineering nanomaterials for mimicking the key bacterial enzymes (e.g., lactonase) functioning in biofilm construction.}, }
@article {pmid37134292, year = {2023}, author = {Strange, M}, title = {Biofilm Management Technology: Air Polishing a Safe, Effective Modality.}, journal = {Compendium of continuing education in dentistry (Jamesburg, N.J. : 1995)}, volume = {44}, number = {5}, pages = {276-277}, pmid = {37134292}, issn = {2158-1797}, abstract = {Biofilms are complex communities of microorganisms that adhere to each other. They thrive and proliferate in all kinds of natural aqueous environments. Dentistry regards biofilms as an etiological factor for a range of oral diseases, including dental caries, periodontal disease, and implant-associated infections.1 This assertion is because the oral cavity and polymicrobial biofilm are home to numerous microbial species, including healthy microorganisms and those with pathogenic potential. Due to their stickiness and ability to multiply on surfaces, biofilms are highly resistant to both the host's defense system and traditional antimicrobials. As a result, the study and understanding of biofilm and resulting management technology have come a long way with novel methods to combat the formation and accumulation of bacterial biofilms on teeth and oral surfaces. Over the years, significant advancements have greatly improved the prevention and treatment of oral diseases caused by biofilms.}, }
@article {pmid37133975, year = {2023}, author = {Duarte, PM and Felix, E and Santos, VR and Figueiredo, LC and da Silva, HD and Mendes, JA and Feres, M and Miranda, TS}, title = {Patients with type 2 diabetes and severe periodontitis harbor a less pathogenic subgingival biofilm than normoglycemic individuals with severe periodontitis.}, journal = {Journal of periodontology}, volume = {}, number = {}, pages = {}, doi = {10.1002/JPER.22-0657}, pmid = {37133975}, issn = {1943-3670}, abstract = {BACKGROUND: If, and to what extent, diabetes mellitus (DM) can affect the subgingival biofilm composition remain controversial. Thus, the aim of this study was to compare the composition of the subgingival microbiota of non-diabetic and type 2 diabetic patients with periodontitis using 40 "biomarker bacterial species".<br><br>METHODS: Biofilm samples of shallow (probing depth (PD) and clinical attachment level (CAL) &#x2264; 3mm without bleeding) and deep sites (PD and CAL &#x2265; 5mm) of patients with or without type 2 DM were evaluated for levels/proportions of 40 bacterial species by checkerboard DNA-DNA hybridization.<br><br>RESULTS: Eight hundred and twenty eight subgingival biofilm samples from 207 patients with periodontitis (118 normoglycemic and 89 with type 2 DM) were analyzed. The levels of most of the bacterial species evaluated were reduced in the diabetic than in the normoglycemic group, both in shallow and in deep sites. The shallow and deep sites of patients with type 2 DM presented higher proportions of Actinomyces species, purple and green complexes, and lower proportions of red complex pathogens than those of normoglycemic patients (p<0.05).<br><br>CONCLUSIONS: Patients with type 2 DM have a less dysbiotic subgingival microbial profile than normoglycemic patients, including lower levels/proportions of pathogens and higher levels/proportions of host-compatible species. Thus, type 2 diabetic patients seem to require less remarkable changes in biofilm composition than non-diabetic patients to develop the same pattern of periodontitis. This article is protected by copyright. All rights reserved.}, }
@article {pmid37133439, year = {2023}, author = {Tran, NN and Morrisette, T and Jorgensen, SCJ and Orench-Benvenutti, JM and Kebriaei, R}, title = {Current therapies and challenges for the treatment of Staphylococcus aureus biofilm-related infections.}, journal = {Pharmacotherapy}, volume = {}, number = {}, pages = {}, doi = {10.1002/phar.2806}, pmid = {37133439}, issn = {1875-9114}, abstract = {Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and contributes to significant increase in morbidity and mortality especially when associated with medical devices and in biofilm form. Biofilm structure provides a pathway for enrichment of resistant and persistent phenotypes of S. aureus leading to relapse and recurrence of infection. Minimal diffusion of antibiotics inside biofilm structure leads to heterogeneity and distinct physiological activity. Additionally, horizontal gene transfer between cells in proximity adds to the challenges associated with eradication of biofilms. This narrative review focuses on biofilm-associated infections caused by S. aureus, the impact of environmental conditions on biofilm formation, interactions inside biofilm communities, and the clinical challenges that they present. Conclusively, potential solutions, novel treatment strategies, combination therapies and reported alternatives are discussed.}, }
@article {pmid37132134, year = {2023}, author = {Shakib, P and Saki, R and Marzban, A and Goudarzi, G and Ghotekar, S and Cheraghipour, K and Zolfaghari, MR}, title = {Antibacterial Effects of Nanocomposites on Efflux Pump Expression and Biofilm Production in Pseudomonas aeruginosa: A Systematic Review.}, journal = {Current pharmaceutical biotechnology}, volume = {}, number = {}, pages = {}, doi = {10.2174/1389201024666230428121122}, pmid = {37132134}, issn = {1873-4316}, abstract = {BACKGROUND: Pseudomonas aeruginosa is an opportunistic gram-negative pathogen with multiple mechanisms of resistance to antibiotics. This systematic review aimed to study the antibacterial effects of nanocomposites on efflux pump expression and biofilm production in P. aeruginosa.<br><br>METHODS: The search was conducted from January 1, 2000, to May 30, 2022, using terms such as (P. aeruginosa) AND (biofilm) AND (antibiofilm activity) AND (anti-Efflux Pump Expression activity) AND (nanoparticles) AND (Efflux Pump Expression) AND (Solid Lipid NPS) AND (Nano Lipid Carriers). Many databases are included in the collection, including ScienceDirect, PubMed, Scopus, Ovid, and Cochrane.<br><br>RESULTS: A list of selected articles was retrieved by using the relevant keywords. A total of 323 published papers were selected and imported into the Endnote library (version X9). Following the removal of duplicates, 240 were selected for further processing. Based on the titles and abstracts of the articles, 54 irrelevant studies were excluded. Among the remaining 186 articles, 54 were included in the analysis because their full texts were accessible. Ultimately, 74 studies were selected based on inclusion/exclusion criteria.<br><br>CONCLUSION: Recent studies regarding the impact of NPs on drug resistance in P. aeruginosa found that various nanostructures were developed with different antimicrobial properties. The results of our study suggest that NPs may be a feasible alternative for combating microbial resistance in P. aeruginosa by blocking flux pumps and inhibiting biofilm formation.}, }
@article {pmid37132080, year = {2023}, author = {Irwin, S and Wang, T and Bolam, SM and Alvares, S and Swift, S and Cornish, J and Williams, D and Ashton, NN and Matthews, BG}, title = {Rat model of recalcitrant prosthetic joint infection using biofilm inocula.}, journal = {Journal of orthopaedic research : official publication of the Orthopaedic Research Society}, volume = {}, number = {}, pages = {}, doi = {10.1002/jor.25587}, pmid = {37132080}, issn = {1554-527X}, abstract = {Prosthetic joint infection (PJI) is a rare but devastating complication of joint arthroplasty. Biofilm formation around the prosthesis confers tolerance to antibiotics so that treatment is challenging. Most animal models of PJI use planktonic bacteria to establish the infection which fails to reproduce the pathology of chronic infection. We aimed to establish a rat model of Staphylococcus aureus PJI in male Sprague Dawley rats using biofilm inocula and demonstrate its tolerance to frontline antibiotics. Pilot studies indicated that infection could be introduced to the knee joint by a biofilm-coated pin but that handling the prosthetic without disturbing the biofilmwas difficult. We therefore developed a pin with a slotted end and used a miniature-biofilm reactor to develop mature biofilm in this niche. These biofilm-laden pins consistently produced infection of the bone and jointspace. Treatment with high dose cefazolin, 250mg/kg, starting the day of surgery reduced or cleared pin-adherent bioburden within seven days, however when escalation from 25mg/kg to 250mg/kg cefazolin treatment was delayed for 48h, rats were unable to clear the infection.To track infections, we used bioluminescentbacteria, however the bioluminescent signal did not accurately track the degree of infection in the bone and joint space as the signal did not penetrate the bone. In conclusion, we demonstrate that using a custom prosthetic pin, we can generate biofilm in a specific niche using a novel bioreactor setup and initiate a rat PJI that rapidly develops tolerance to supra-clinical doses of cefazolin. This article is protected by copyright. All rights reserved.}, }
@article {pmid37129770, year = {2023}, author = {Young, ES and Butler, JD and Molesworth-Kenyon, SJ and Kenyon, WJ}, title = {Biofilm-Mediated Fragmentation and Degradation of Microcrystalline Cellulose by Cellulomonas flavigena KU (ATCC 53703).}, journal = {Current microbiology}, volume = {80}, number = {6}, pages = {200}, pmid = {37129770}, issn = {1432-0991}, mesh = {*Cellulose/metabolism ; *Glucans ; Biofilms ; }, abstract = {Cellulomonas flavigena KU (ATCC 53703) produces an extracellular matrix involved in the degradation of microcrystalline cellulose. This extracellular material is primarily composed of the gel-forming, β-1,3-glucan known as curdlan and associated, cellulose-degrading enzymes. In this study, the effects of various forms of nutrient limitation on cellulose attachment, cellular aggregation, curdlan production, and biofilm formation were investigated throughout a 7-day incubation period by using phase-contrast microscopy. Compared to cultures grown in non-limiting media, nitrogen-limitation promoted early attachment of C. flavigena KU cells to the cellulose surface, and cellulose attachment was congruent with cellular aggregation and curdlan production. Over the course of the experiment, microcolonies of attached cells grew into curdlan-producing biofilms on the cellulose. By contrast, bacterial cells grown on cellulose in non-limiting media remained unattached and unaggregated throughout most of the incubation period. By 7 days of incubation, bacterial aggregation was ninefold greater in N-limited cultures compared to nutritionally complete cultures. In a similar way, phosphorus- and vitamin-limitation (i.e., yeast extract-limitation) also resulted in early cellulose attachment and biofilm formation. Furthermore, nutrient limitation promoted more rapid and efficient fragmentation and degradation of cellulose, with cellulose fragments in low-N media averaging half the size of those in high-N media after 7 days. Two modes of cellulose degradation are proposed for C. flavigena KU, a "planktonic mode" and a "biofilm mode". Similar observations have been reported for other curdlan-producing cellulomonads, and these differing cellulose degradation strategies may ultimately prove to reflect sequential stages of a multifaceted biofilm cycle important in the bioconversion of this abundant and renewable natural resource.}, }
@article {pmid37129526, year = {2023}, author = {Vasicek, EM and Gunn, JS}, title = {Invasive Non-Typhoidal Salmonella Lineage Biofilm Formation and Gallbladder Colonization Vary But Do Not Correlate Directly with Known Biofilm-Related Mutations.}, journal = {Infection and immunity}, volume = {}, number = {}, pages = {e0013523}, doi = {10.1128/iai.00135-23}, pmid = {37129526}, issn = {1098-5522}, abstract = {Non-typhoidal Salmonella (NTS) serovars have a broad host range and cause gastroenteritis in humans. However, invasive NTS (iNTS) bloodstream infections have increased in the last decade, causing 60,000 deaths annually. Human-specific typhoidal Salmonella colonizes and forms biofilms on gallstones, resulting in chronic, asymptomatic infection. iNTS lineages are undergoing genomic reduction and may have adapted to person-to-person transmission via mutations in virulence, bile resistance, and biofilm formation. As such, we sought to determine the capacity of iNTS lineages for biofilm formation and the development of chronic infections in the gallbladder in our mouse model. Of the lineages tested (L1, L2, L3 and UK), only L2 and UK were defective for the rough, dry and red (RDAR) morphotype, correlating with the known bcsG (cellulose) mutation but not with csgD (curli) gene mutations. Biofilm-forming ability was assessed in vitro, which revealed a biofilm formation hierarchy of L3 > ST19 > UK > L1 = L2, which did not correlate directly with either the bcsG or the csgD mutation. By confocal microscopy, biofilms of L2 and UK had significantly less curli and cellulose, while L1 biofilms had significantly lower cellulose. All iNTS strains were able to colonize the mouse gallbladder, liver, and spleen in a similar manner, while L3 had a significantly higher bacterial load in the gallbladder and increased lethality. While there was iNTS lineage variability in biofilm formation, gallbladder colonization, and virulence in a chronic mouse model, all tested lineages were capable of colonization despite possessing biofilm-related mutations. Thus, iNTS strains may be unrecognized chronic pathogens in endemic settings.}, }
@article {pmid37129321, year = {2023}, author = {Bernardi, S and Qorri, E and Botticelli, G and Scarano, A and Marzo, G and Gatto, R and Greco Lucchina, A and Mortellaro, C and Lupi, E and Rastelli, C and Falisi, G}, title = {Use of electrical field for biofilm implant removal.}, journal = {European review for medical and pharmacological sciences}, volume = {27}, number = {3 Suppl}, pages = {114-121}, doi = {10.26355/eurrev_202304_31328}, pmid = {37129321}, issn = {2284-0729}, mesh = {Humans ; *Peri-Implantitis ; *Mucositis ; Device Removal ; Biofilms ; Microscopy, Electron, Scanning ; *Dental Implants ; Surface Properties ; }, abstract = {OBJECTIVE: New methods for biofilm removal are being investigated. A recent new one involves the use of the electric field for biofilm removal. In particular, electrolytic cleaning works on the adhesion forces of the biofilm on the surfaces, with few studies showing promising results in decontamination and implant re-integration in the bone. This study aims at assessing the effect of a new decontamination device that implies the electric field for implant-biofilm removal.<br><br>MATERIALS AND METHODS: Three implants affected by peri-implantitis were selected for the study. After the treatment, the implants were observed by the Scanning Electron Microscopy.<br><br>RESULTS: All three samples showed no microbial biofilm in the application area, while the rest of the surface observed was covered with microbial biofilm, with an intensely thickened bacterial population.<br><br>CONCLUSIONS: Peri-mucositis and peri-implantitis prevention and early treatments are essential for implant maintenance, thus saving the surrounding hard and soft tissues. The technological innovation is providing electrolytic devices which act not only on the microbial population but on the biofilm adhesion to the implant surface, with promising results for a new and valid therapeutic option.}, }
@article {pmid37127198, year = {2023}, author = {Han, Y and Yang, P and Feng, Y and Wang, N and Yuan, X and An, J and Liu, J and Li, N and He, W}, title = {Liquid-gas phase transition enables microbial electrolysis and H2-based membrane biofilm hybrid system to degrade organic pollution and achieve effective hydrogenotrophic denitrification of groundwater.}, journal = {Chemosphere}, volume = {331}, number = {}, pages = {138819}, doi = {10.1016/j.chemosphere.2023.138819}, pmid = {37127198}, issn = {1879-1298}, abstract = {Electron-donor Lacking was the limiting factor for the denitrification of oligotrophic groundwater and hydrogenotrophic denitrification provided an efficient approach without secondary pollution. In this study, a hybrid system with microbial electrolysis cell (MEC) assisted hydrogen-based membrane biofilm reactor (MBfR) was established for advanced groundwater denitrification. The liquid-gas phase transition prevented the potential pollution from organic wastes in MEC to groundwater, while the bubble-free diffusion of MBfR promoted hydrogen utilization efficiency. The negative-pressure extraction from MEC and the positive pressure for gas supply into MBfR increased the hydrogen proportion and current density of MEC, and improved the kinetic constant K of the denitrification reaction in MBfR. With actual groundwater, the MEC-MBfR hybrid system achieved a nitrate reduction of 97.8% with an effluent NO3[-]-N of 2.2 ± 1.0 mg L[-1]. The hydrogenotrophic denitrifiers of Thauera, Pannonibacter, and Azonexus, dominated the denitrification biofilm on the membrane and elastic filler in MBfR.}, }
@article {pmid37127169, year = {2023}, author = {Zhang, X and Zuo, S and Li, S and Shang, Y and Du, Q and Wang, H and Guo, W and Hao Ngo, H}, title = {Responses of biofilm communities in a hybrid moving bed biofilm reactor-membrane bioreactor system to sulfadiazine antibiotic exposure.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {129126}, doi = {10.1016/j.biortech.2023.129126}, pmid = {37127169}, issn = {1873-2976}, abstract = {Antibiotics in wastewater can affect the structures and functions of bacterial communities, subsequently influencing how well a biological process performs. Therefore, the characteristics of bacterial community were investigated in a hybrid moving bed biofilm reactor-membrane bioreactor system when treating domestic wastewater containing sulfadiazine (SDZ). Results indicated total nitrogen removal reduced by 10.2%, 9.1%, 2.7% and 2.9%, respectively, with increasing carbon to nitrogen (C/N) ratios (2.5, 4, 6 and 9) when SDZ was present (0.5 mg/L). The microbial communities' analysis revealed that the abundance of nitrogen removal-related bacteria increased with C/N. Specifically, the abundance of ammonia-oxidizing bacteria (0.46%-0.90%) was low, and the nitrite-oxidizing bacteria (2.16%-7.13%) and denitrifying bacteria showed a significant increase (Hyphomicrobium: 0.57%-3.54%) when C/N ratio increased. The abundance of denitrifying bacterial declined by 4.82-8.56% at different C/N ratios, while nitrifying bacterial rose by 0.70-5.67%. Interestingly, the denitrifying bacteria Enterobacter, Sphingomonas and Gemmatimonas acted as mutualistic bacteria that stabilized denitrification.}, }
@article {pmid37125396, year = {2023}, author = {Díaz-Navarro, M and Irigoyen Von-Sierakowski, &#xc1; and Palomo, M and Escribano, P and Guinea, J and Burillo, A and Galar, A and Muñoz, P and Guembe, M}, title = {In vitro study to assess modulation of Candida biofilm by Escherichia coli from vaginal strains.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100116}, pmid = {37125396}, issn = {2590-2075}, abstract = {BACKGROUND: Vulvovaginal candidiasis (VVC) is caused by biofilm formation and epithelial invasion. In addition, Escherichia coli (EC) can establish a vaginal intracellular reservoir modulating Candida spp. biofilm production. We aimed to analyze the behavior of Candida albicans (CA) and EC biofilm both in single cultures and in co-cultures.<br><br>METHODS: We prospectively collected CA and EC isolates from vaginal swabs over 6 months. We selected positive cultures with both CA and EC (cases) and a comparator group with either CA or EC (controls). We analyzed overall biomass production and metabolic activity in single cultures and in co-cultures based on staining assays, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) to assess biofilm occupation. We also analyzed clinical manifestations.<br><br>RESULTS: We cultured 455 samples, 16 (3.5%) of which had CA and EC (cases); only CA or EC (controls) was detected, respectively, in 72 (15.8%) and 98 (21.5%). Biomass production and metabolic activity were significantly more pronounced in co-cultures in both groups. CLSM and SEM, on the other hand, showed the biofilm of each species to be significantly reduced when they were cultured together, with higher values in CA (percentage biofilm reduction: CA, 95.8% vs. EC, 36.2%, p&#xa0;<&#xa0;0.001). There were no clinically significant differences between co-infected patients and patients infected only by C. albicans.<br><br>CONCLUSION: Ours is the first study assessing co-cultures of CA and EC in a large collection of samples. We observed that coinfection of CA and EC was unusual (3.5%) and promoted high biomass, whereas microscopy enabled us to detect a reduction in biofilm production when microorganisms were co-cultured. No differences in symptoms were observed.}, }
@article {pmid37125394, year = {2023}, author = {Lamret, F and Lemaire, A and Lagoutte, M and Varin-Simon, J and Abraham, L and Colin, M and Braux, J and Velard, F and Gangloff, SC and Reffuveille, F}, title = {Approaching prosthesis infection environment: Development of an innovative in vitro Staphylococcus aureus biofilm model.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100120}, pmid = {37125394}, issn = {2590-2075}, abstract = {The major role and implication of bacterial biofilms in the case of bone and prosthesis infections have been highlighted and often linked to implant colonization. Management strategies of these difficult-to-treat infections consist in surgeries and antibiotic treatment, but the rate of relapse remains high, especially if Staphylococcus aureus, a high-virulent pathogen, is involved. Therapeutic approaches are not adapted to the specific features of biofilm in bone context whereas infectious environment is known to importantly influence biofilm structure. In the present study, we aim to characterize S. aureus SH1000 (methicillin-sensitive strain, MSSA) and USA300 (methicillin-resistant strain, MRSA) biofilm on different surfaces mimicking the periprosthetic environment. As expected, protein adsorption on titanium enhanced the number of adherent bacteria for both strains. On bone explant, USA300 adhered more than SH1000. The simultaneous presence of two different surfaces was also found to change the bacterial behaviour. Thus, proteins adsorption on titanium and bone samples (from bank or directly recovered after an arthroplasty) were found to be key parameters that influence S. aureus biofilm formation: adhesion, matrix production and biofilm-related gene regulation. These results highlighted the need for new biofilm models, more relevant with the infectious environment by using adapted culture medium and presence of surfaces that are representative of in situ conditions to better evaluate therapeutic strategies against biofilm.}, }
@article {pmid37125177, year = {2023}, author = {Sadiq, FA and De Reu, K and Burmølle, M and Maes, S and Heyndrickx, M}, title = {Synergistic interactions in multispecies biofilm combinations of bacterial isolates recovered from diverse food processing industries.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1159434}, pmid = {37125177}, issn = {1664-302X}, abstract = {Most biofilms within the food industry are formed by multiple bacterial species which co-exist on surfaces as a result of interspecies interactions. These ecological interactions often make these communities tolerant against antimicrobials. Our previous work led to the identification of a large number (327) of highly diverse bacterial species on food contact surfaces of the dairy, meat, and egg industries after routine cleaning and disinfection (C&amp;D) regimes. In the current study, biofilm-forming ability of 92 bacterial strains belonging to 26 genera and 42 species was assessed and synergistic interactions in biofilm formation were investigated by coculturing species in all possible four-species combinations. Out of the total 455 four-species biofilm combinations, greater biofilm mass production, compared to the sum of biofilm masses of individual species in monoculture, was observed in 34 combinations. Around half of the combinations showed synergy in biofilm mass > 1.5-fold and most of the combinations belonged to dairy strains. The highest synergy (3.13-fold) was shown by a combination of dairy strains comprising Stenotrophomonas rhizophila, Bacillus licheniformis, Microbacterium lacticum, and Calidifontibacter indicus. The observed synergy in mixed biofilms turned out to be strain-specific rather than species-dependent. All biofilm combinations showing remarkable synergy appeared to have certain common species in all combinations which shows there are keystone industry-specific bacterial species which stimulate synergy or antagonism and this may have implication for biofilm control in the concerned food industries.}, }
@article {pmid37123502, year = {2023}, author = {Dao, A and O'Donohue, AK and Vasiljevski, ER and Bobyn, JD and Little, DG and Schindeler, A}, title = {Murine models of orthopedic infection featuring Staphylococcus aureus biofilm.}, journal = {Journal of bone and joint infection}, volume = {8}, number = {2}, pages = {81-89}, pmid = {37123502}, issn = {2206-3552}, abstract = {Introduction: Osteomyelitis remains a major clinical challenge. Many published rodent fracture infection models are costly compared with murine models for rapid screening and proof-of-concept studies. We aimed to develop a dependable and cost-effective murine bone infection model that mimics bacterial bone infections associated with biofilm and metal implants. Methods: Tibial drilled hole (TDH) and needle insertion surgery (NIS) infection models were compared in C57BL/6 mice (female, N = 150). Metal pins were inserted selectively into the medullary canal adjacent to the defect sites on the metaphysis. Free Staphylococcus aureus (ATCC 12600) or biofilm suspension (ATCC 25923) was locally inoculated. Animals were monitored for physiological or radiographic evidence of infection without prophylactic antibiotics for up to 14 d. At the end point, bone swabs, soft-tissue biopsies, and metal pins were taken for cultures. X-ray and micro-CT scans were performed along with histology analysis. Results: TDH and NIS both achieved a 100 % infection rate in tibiae when a metal implant was present with injection of free bacteria. In the absence of an implant, inoculation with a bacterial biofilm still induced a 40 %-50 % infection rate. In contrast, freely suspended bacteria and no implant consistently showed lower or negligible infection rates. Micro-CT analysis confirmed that biofilm infection caused local bone loss even without a metal implant as a nidus. Although a metal surface permissive for biofilm formation is impermeable to create progressive bone infections in animal models, the metal implant can be dismissed if a bacterial biofilm is used. Conclusion: These models have a high potential utility for modeling surgery-related osteomyelitis, with NIS being simpler to perform than TDH.}, }
@article {pmid37123152, year = {2022}, author = {Kareem Musafer, H and Nabeeh Jaafar, F and Ahmed Al-Bayati, M}, title = {Association of Biofilm Inducer with bla VIM, bla IMP, and bla NDM in Pseudomonas aeruginosa Isolates.}, journal = {Archives of Razi Institute}, volume = {77}, number = {5}, pages = {1723-1728}, pmid = {37123152}, issn = {2008-9872}, mesh = {Animals ; *Pseudomonas aeruginosa/genetics ; Meropenem ; beta-Lactamases/genetics ; Bacterial Proteins/genetics ; *Pseudomonas Infections/epidemiology/microbiology/veterinary ; Imipenem ; Carbapenems ; }, abstract = {Pseudomonas aeruginosa (P. aeruginosa) is a ubiquitous opportunistic organism that is hard to treat. This study aimed to investigate the association of bla VIM, bla IMP, and bla NDM prevalence with Cyclic di-GMP (c-di-GMP) in P. aeruginosa. To this end, 27 clinical isolates of P. aeruginosa were obtained from different hospitals in Baghdad, Iraq. The phenotypic detection of carbapenem and biofilm assays was performed by the M63 minimal medium, supplemented with glucose, magnesium sulfate. The polymerase chain reaction was utilized to detect carbapenem genes. The results showed that the isolates were highly resistant to Imipenem (37%) and Meropenem (63%). Imipenem (37%) and Meropenem (63%) demonstrated a moderate sensitivity against P. aeruginosa. The P. aeruginosa No.5 showed high resistance to carbapenem by bla VIM [+], bla IMP [+], and bla NDM [+], followed by a robust biofilm confirmed with c-di-GMP levels and the twitching motility ability. Upon these findings, the use of antibiotics should be restricted to severe bacterial infections to avoid the rapid emergence of new resistant isolates, which leads to the hard treatment of infection with P. aeruginosa. It is highly recommended that these findings be notified for infectious control. Future studies can investigate the link between transferable resistant genes and c-di-GMP values.}, }
@article {pmid37122169, year = {2023}, author = {Aguiar, ALR and Silva, BND and Fiallos, NM and Pereira, LMG and Silva, ML and Souza, PFSM and Portela, FVM and Sidrim, JJC and Rocha, MFG and Castelo-Branco, DSCM and Cordeiro, RA}, title = {Promethazine inhibits efflux, enhances antifungal susceptibility and disrupts biofilm structure and functioning in Trichosporon.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-13}, doi = {10.1080/08927014.2023.2202315}, pmid = {37122169}, issn = {1029-2454}, abstract = {Trichosporon spp. are emerging opportunistic fungi associated with invasive infections, especially in patients with haematological malignancies. The present study investigated the in vitro inhibition of efflux pumps by promethazine (PMZ) as a strategy to control T. asahii and T. inkin. Planktonic cells were evaluated for antifungal susceptibility to PMZ, as well as inhibition of efflux. The effect of PMZ was also studied in Trichosporon biofilms. PMZ inhibited T. asahii and T. inkin planktonic cells at concentrations ranging from 32 to 256 μg[ ]ml[-1]. Subinhibitory concentrations of PMZ inhibited efflux activity in Trichosporon. Biofilms were completely eradicated by PMZ. PMZ potentiated the action of antifungals, affected the morphology, changed the amount of carbohydrates and proteins and reduced the amount of persister cells inside biofilms. The results showed indirect evidences of the occurrence of efflux pumps in Trichosporon and opens a perspective for the use of this target in the control of trichosporonosis.}, }
@article {pmid37121323, year = {2023}, author = {Zheng, S and Lin, T and Chen, H and Zhang, X and Jiang, F}, title = {Characterization of young biofilm morphology, disinfection byproduct formation potential and toxicity of renewed water supply pipelines by phosphorus release from corroded pipes.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {163813}, doi = {10.1016/j.scitotenv.2023.163813}, pmid = {37121323}, issn = {1879-1026}, abstract = {The deterioration of drinking water quality due to corrosion of the water supply network has become inevitable and regular renewal of pipes has become a common means of doing so. Severely corroded pipes release certain nutrients (e.g., elemental phosphorus), however, little has been reported on the effect of old pipes on the young biofilm of new pipe sections and on ensuring water safety in the early stages of the water supply. The aim of our study was to model the effect of key phosphorus nutrients released from corroded old pipes on the morphological characteristics of young biofilms in new pipe sections, mediated disinfection byproducts (DBPs) production and their combined toxicity. Based on the experimental results, phosphorus showed significant differences in the morphological characteristics, spatial structure of extracellular polymers (EPS), functional abundance, disinfection byproduct formation potential (DBPsFP) and toxicity of young biofilms. Under residual chlorine (1.0 ± 0.2 mg/L) incubation, the functional abundance of young biofilm metabolism was dominant, particularly amino acid metabolism and carbohydrate metabolism. There is a dynamic balance between the trophic and shedding effects of phosphorus, where concentration changes affect young biofilm morphology and DBPFP. Relatively moderate phosphorus concentrations resulted in the highest density of PN/PS organic precursors in EPS and a clear advantage of DBPFP; relatively high phosphorus conditions had limited promotion of young biofilm, while membrane structure shedding was more pronounced, increasing young biofilm-mediated DBPs production. Nitrogen-containing disinfection byproducts (N-DBPs) in young biofilms had a clear toxicity advantage, with HANs and HNMs being key to controlling cytotoxicity and genotoxicity, respectively.}, }
@article {pmid37121181, year = {2023}, author = {Kang, D and Zhang, L and Yang, S and Li, J and Peng, Y}, title = {Linking morphological features to anammox communities in a partial nitritation and anammox (PN/A) biofilm reactor.}, journal = {Journal of environmental management}, volume = {341}, number = {}, pages = {118038}, doi = {10.1016/j.jenvman.2023.118038}, pmid = {37121181}, issn = {1095-8630}, abstract = {Partial nitritation/anammox (PN/A) has been recognized as a cost-efficient process for wastewater nitrogen removal. The addition of carriers could help achieve biomass retention and enhance the treatment efficiency by forming the dense biofilm. However, accurately determining the abundance of anammox bacteria (AnAOB) to evaluate the biofilm development still remains challenging in practice without access to specialized facilities and experimental skills. In this study, we explored the feasibility of utilizing the morphological features of anammox biofilm as an indication of the biofilm development progression, and its correlation with microbial communities was also revealed. The time-series biofilms from an integrated fixed-film activated sludge (IFAS) system with stable PN/A performance were sampled representing the different biofilm development stages. The biofilm morphological features including color and texture were respectively quantified by red (R) coordinate and Local binary pattern (LBP) descriptor via image processing. Hierarchy clustering analysis proved that the extracted morphological descriptors could well distinguish the different stages (colonization, succession, and maturation) of biofilm development. The microbial community dynamics of time-series anammox biofilms were investigated using the amplicon sequence variant (ASV) analysis. Candidatus Brocadia, as the typical AnAOB, dominated in the whole communities of 16.3%-20.0%, moreover, the biofilm development was found to be driven by distinct Brocadia species. Linear regression evidenced that the Brocadia abundance could be directly correlated to the value of R and LBP, and the total variation of microbial communities could be significantly explained by the morphological features via redundancy analysis. This study demonstrates a new way to monitor the biofilm development by extracting the visible features of anammox aggregates, which can help facilitate the automated control of anammox-based bioprocess.}, }
@article {pmid37120944, year = {2023}, author = {Wang, S and Mirmiran, SD and Li, X and Li, X and Zhang, F and Duan, X and Gao, D and Chen, Y and Chen, H and Qian, P}, title = {Temperate phage influence virulence and biofilm-forming of Salmonella Typhimurium and enhance the ability to contaminate food product.}, journal = {International journal of food microbiology}, volume = {398}, number = {}, pages = {110223}, doi = {10.1016/j.ijfoodmicro.2023.110223}, pmid = {37120944}, issn = {1879-3460}, abstract = {Salmonella is a food-borne zoonotic pathogen that threatens food safety and public health security. Temperate phages can influence bacterial virulence and phenotype and play an important role in bacterial evolution. However, most studies on Salmonella temperate phages focus on prophage induced by bacteria, with few reports on Salmonella temperate phages isolated in the environment. Moreover, whether temperate phages drive bacterial virulence and biofilm formation in food and animal models remains unknown. In this study, Salmonella temperate phage vB_Sal_PHB48 was isolated from sewage. TEM and phylogenetic analysis indicated that phage PHB48 belongs to the Myoviridae family. Additionally, Salmonella Typhimurium integrating PHB48 was screened and designated as Sal013[+]. Whole genome sequencing revealed that the integration site was specific and we confirmed that the integration of PHB48 did not change the O-antigen and coding sequences of Sal013. Our in vitro and in vivo studies showed that the integration of PHB48 could significantly enhance the virulence and biofilm formation of S. Typhimurium. More importantly, the integration of PHB48 significantly improved the colonization and contamination ability of bacteria in food samples. In conclusion, we isolated Salmonella temperate phage directly from the environment and systematically clarified that PHB48 enhanced the virulence and biofilm-forming ability of Salmonella. In addition, we found that PHB48 increased the colonization and contamination ability of Salmonella in food samples. These results indicated that the highly pathogenic Salmonella induced by temperate phage was more harmful to food matrices and public health security. Our results could enhance the understanding of the evolutionary relationship between bacteriophages and bacteria, and raise public awareness of large-scale outbreaks resulting from Salmonella virulence enhancement in food industry.}, }
@article {pmid37120455, year = {2023}, author = {Singh, I and Roshan, M and Vats, A and Behera, M and Gautam, D and Rajput, S and Rana, C and De, S}, title = {Evaluation of Virulence, Antimicrobial Resistance and Biofilm Forming Potential of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Bovine Suspected with Mastitis.}, journal = {Current microbiology}, volume = {80}, number = {6}, pages = {198}, pmid = {37120455}, issn = {1432-0991}, mesh = {Female ; Animals ; Cattle ; Humans ; *Methicillin-Resistant Staphylococcus aureus ; Anti-Bacterial Agents/pharmacology ; Virulence/genetics ; *Staphylococcal Infections/veterinary ; Drug Resistance, Bacterial ; Biofilms ; Virulence Factors/genetics ; *Mastitis, Bovine ; Microbial Sensitivity Tests ; }, abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen that poses a significant threat in cases of chronic mastitis in dairy animals. The ability of MRSA to persist in the host is attributed to various virulence factors, genes encoding surface adhesins, and determinants of antibiotic resistance, which provide it a survival advantage. This investigation focused to determine the virulence factors, antimicrobial resistance (AMR) profile and biofilm production potential of 46 MRSA isolates from 300 bovine mastitis milk samples. The AMR profile revealed a high level of resistance, with 46 and 42 isolates resistant to cefoxitin and oxacillin, respectively, followed by 24 and 12 isolates resistant to lomefloxacin and erythromycin, respectively. Only 2 isolates resistant to tetracycline and none were resistant to chloramphenicol. The study also evaluated various virulence factors such as coa (n = 46), nuc (n = 35) hlg (n = 36), pvl (n = 14), tsst-1(n = 28) spa (n = 39) and enterotoxin genes sea (n = 12) and seg (n = 28) and identified antibiotic resistance determinants mecA and blaZ in 46 and 27 isolates, respectively. Intercellular adhesion genes icaA and icaD were present in 40 and 43 isolates, respectively and surface adhesion genes ebps, fnbpA, eno, sasG, cna, and bap were found in 43, 40, 38, 26, 21 and 1 isolates, respectively. Microtiter plate (MTP) assay revealed that 29 MRSA isolates were capable of producing biofilms, whereas 17 were not. Biofilms producing MRSA isolates possessed adhesion genes, virulence factors, toxin genes and AMR genes that may act synergistically towards a chronic disease progression, illness and severe damage to the udder, which generally last for several months and very challenging to cure.}, }
@article {pmid37120241, year = {2023}, author = {He, X and Ding, H and Gao, Z and Zhang, X and Wu, R and Li, K}, title = {Variations in the motility and biofilm formation abilities of Escherichia coli O157:H7 during noodle processing.}, journal = {Food research international (Ottawa, Ont.)}, volume = {168}, number = {}, pages = {112670}, doi = {10.1016/j.foodres.2023.112670}, pmid = {37120241}, issn = {1873-7145}, mesh = {*Escherichia coli O157 ; Biofilms ; Food Handling ; Repressor Proteins/pharmacology ; RNA-Binding Proteins/pharmacology ; *Escherichia coli Proteins/metabolism ; }, abstract = {Motility and biofilm formation help to protect bacteria from host immune responses and facilitate tolerance of environmental stimuli to improve their adaptability. However, few reports have investigated the adaptability of bacteria that live in food substrates undergoing food processing-induced stress. In this study, variations in the surface morphology, bacterial count, motility, and biofilm formation abilities of Escherichia coli O157:H7 NCTC12900 were investigated during noodle processing, including the kneading, squeezing, resting, and sheeting phases. The results showed that bacterial surface morphology, count, and motility were impaired in the squeezing phase, whereas biofilm biomass continuously increased across all processing phases. Twenty-one genes and sRNAs were measured using RT-qPCR to reveal the mechanisms underlying these changes. Of these, the genes adrA, csrA, flgM, flhD, fliM, ydaM, and the sRNA McaS were significantly upregulated, whereas the genes fliA, fliG, and the sRNAs CsrC, DsrA, GcvB, and OxyS were evidently repressed. According to the correlation matrix results based on the reference gene adrA, we found that csrA, GcvB, McaS, and OxyS were the most relevant genes and sRNAs for biofilm formation and motility. For each of them, their overexpressions was found to inhibit bacterial motility and biofilm formation to varying degrees during noodle processing. Among these, 12900/pcsrA had the highest inhibitory potential against motility, yielding a minimum of 11.2 mm motility diameter in the resting phase. Furthermore, 12900/pOxyS showed the most significant inhibitory effect against biofilm formation, yielding a minimum biofilm formation value of 5% of that exhibited the wild strain in the sheeting phase. Therefore, we prospect to find an effective and feasible novel approach to weaken bacterial survival during food processing by regulating the genes or sRNAs related to motility and biofilm formation.}, }
@article {pmid37116243, year = {2023}, author = {Daffinee, KE and O'Neill, ET and Bleick, CR and Williams, G and Antoci, V and Garcia, D and LaPlante, KL}, title = {Staphylococcal biofilm: penetration and bioavailability of vancomycin with or without rifampin.}, journal = {Diagnostic microbiology and infectious disease}, volume = {106}, number = {3}, pages = {115947}, doi = {10.1016/j.diagmicrobio.2023.115947}, pmid = {37116243}, issn = {1879-0070}, abstract = {We measured antibiotic penetration and bioavailability in staphylococcus biofilms using simulated humanized concentrations of fluorescent vancomycin plus or minus rifampin. Vancomycin percent recovery across biofilm layers was:upper = 46%, middle = 40%, and lower = 33%. Vancomycin plus rifampin was not significantly different (P = 0.65). Addition of rifampin did not improve vancomycin penetration across biofilm layers.}, }
@article {pmid37115440, year = {2023}, author = {Tziourrou, P and Vakros, J and Karapanagioti, HK}, title = {Diffuse reflectance spectroscopy (DRS) and infrared (IR) measurements for studying biofilm formation on common plastic litter polymer (LDPE and PET) surfaces in three different laboratory aquatic environments.}, journal = {Environmental science and pollution research international}, volume = {}, number = {}, pages = {}, pmid = {37115440}, issn = {1614-7499}, abstract = {Different species of microorganisms colonize the plastic surfaces and form biofilms depending on the aquatic environment. In the current investigation, characteristics of the plastic surface after exposure to three different aquatic environments based on visualization using scanning electron microscopy (SEM) and spectroscopic (diffuse reflectance (DR) and infrared (IR)) techniques were examined in laboratory bioreactors with time. For both materials, there were no differences observed in the ultraviolet (UV) region among the reactors and several peaks were observed with fluctuating intensities and without any trends. For light density polyethylene (LDPE), peaks indicating the presence of biofilm could be observed in the visible region for activated sludge bioreactor, and for polyethylene terephthalate (PET), freshwater algae biofilm was also visible. PET in freshwater bioreactor is the most densely populated sample both under the optical microscope and SEM. Based on the DR spectra, different visible peaks for LDPE and PET were observed but, in both cases, the visible region peaks (~ 450 and 670 nm) correspond to the peaks found in the water samples of the bioreactors. The difference on these surfaces could not be identified with IR but the fluctuations observed in the UV wavelength region were also detectable using indices obtained from the IR spectra such as keto, ester, and vinyl. For instance, the virgin PET sample shows higher values in all the indices than the virgin LDPE sample [(virgin LDPE: ester Index (I) = 0.051, keto I = 0.039, vinyl I = 0.067), (virgin PET: ester I = 3.5, keto I = 19, vinyl I = 0.18)]. This suggests that virgin PET surface is hydrophilic as expected. At the same time, for all the LDPE samples, all the indices demonstrated higher values (especially for R2) than the virgin LDPE. On the other hand, ester and keto indices for PET samples demonstrated lower values than virgin PET. In addition, DRS technique was able to identify the formation of the biofilm both on wet and dry samples. Both DRS and IR can describe changes in the hydrophobicity during the initial formation of biofilm but DRS can better describe the fluctuations of biofilm in the visible spectra region.}, }
@article {pmid37115139, year = {2023}, author = {Uchoa-Junior, FA and Barata, TJE and Leão-Vasconcelos, LSNO and Ribeiro, EL and Tipple, AFV}, title = {Biofilm on and structural damage of rotary cutting instruments after 5 cycles of clinical use and processing.}, journal = {Journal of the American Dental Association (1939)}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.adaj.2023.03.005}, pmid = {37115139}, issn = {1943-4723}, abstract = {BACKGROUND: Rotary cutting instruments (RCIs) are sterilized routinely. The authors aimed to analyze the structural integrity, presence of dirt, and microbial contamination of RCIs used in clinical practice after processing.<br><br>METHODS: Eighty-four RCIs (42 carbide burs, 42 diamond burs) were divided into baseline, control, and test groups. The RCIs were evaluated by means of scanning electron microscopy and microbiological analysis. Evaluation criteria included presence of structural damage, dirt, biofilm, and isolated cells and their phenotypic profile.<br><br>RESULTS: The carbide burs from all groups and diamond burs from the test groups had structural damage. Dirt was observed in the baseline and test groups. Three bacterial species were isolated from 4 RCIs (9.52%). An isolated cell was observed from 1 carbide bur. Biofilm was observed on 3 RCIs (7.14%).<br><br>CONCLUSIONS: RCIs should not be subjected to multiple uses; after the first clinical use they accumulate structural damage and dirt that hampers the cleaning step, causing failure in the sterilization process.<br><br>PRACTICAL IMPLICATIONS: The presence of microorganisms and structural damage on the RCIs confirmed that they are not amenable to processing, a fact that characterizes them as a single-use health care product.}, }
@article {pmid37111983, year = {2023}, author = {Osman, RB and Khoder, G and Fayed, B and Kedia, RA and Elkareimi, Y and Alharbi, N}, title = {Influence of Fabrication Technique on Adhesion and Biofilm Formation of Candida albicans to Conventional, Milled, and 3D-Printed Denture Base Resin Materials: A Comparative In Vitro Study.}, journal = {Polymers}, volume = {15}, number = {8}, pages = {}, pmid = {37111983}, issn = {2073-4360}, abstract = {The aim of this study was to evaluate the adhesion and biofilm formation of Candida albicans (C. albicans) on conventionally fabricated, milled, and 3D-printed denture base resin materials in order to determine the susceptibility of denture contamination during clinical use. Specimens were incubated with C. albicans (ATCC 10231) for 1 and 24 h. Adhesion and biofilm formation of C. albicans were assessed using the field emission scanning electron microscopy (FESEM). The XTT (2,3-(2-methoxy-4-nitro-5-sulphophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide) assay was used for the quantification of fungal adhesion and biofilm formation. The data were analyzed using GraphPad Prism 8.02 for windows. One-way ANOVA with Tukey's post hoc testing were performed with a statistical significance level set at α = 0.05. The quantitative XTT biofilm assay revealed significant differences in the biofilm formation of C. albicans between the three groups in the 24 h incubation period. The highest proportion of biofilm formation was observed in the 3D-printed group, followed by the conventional group, while the lowest candida biofilm formation was observed in the milled group. The difference in biofilm formation among the three tested dentures was statistically significant (p < 0.001). The manufacturing technique has an influence on the surface topography and microbiological properties of the fabricated denture base resin material. Additive 3D-printing technology results in increased candida adhesion and the roughest surface topography of maxillary resin denture base as compared to conventional flask compression and CAD/CAM milling techniques. In a clinical setting, patients wearing additively manufactured maxillary complete dentures are thus more susceptible to the development of candida-associated denture stomatitis and accordingly, strict oral hygiene measures and maintenance programs should be emphasized to patients.}, }
@article {pmid37111459, year = {2023}, author = {Doulgeraki, AI and Kamarinou, CS and Nychas, GE and Argyri, AA and Tassou, CC and Moulas, G and Chorianopoulos, N}, title = {Role of Microbial Interactions across Food-Related Bacteria on Biofilm Population and Biofilm Decontamination by a TiO2-Nanoparticle-Based Surfactant.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {4}, pages = {}, pmid = {37111459}, issn = {2076-0817}, abstract = {Microbial interactions play an important role in initial cell adhesion and the endurance of biofilm toward disinfectant stresses. The present study aimed to evaluate the effect of microbial interactions on biofilm formation and the disinfecting activity of an innovative photocatalytic surfactant based on TiO2 nanoparticles. Listeria monocytogenes, Salmonella Enteritidis, Escherichia coli, Leuconostoc spp., Latilactobacillus sakei, Serratia liquefaciens, Serratia proteomaculans, Citrobacter freundii, Hafnia alvei, Proteus vulgaris, Pseudomonas fragi, and Brochothrix thermosphacta left to form mono- or dual-species biofilms on stainless steel (SS) coupons. The effectiveness of the photocatalytic disinfectant after 2 h of exposure under UV light on biofilm decontamination was evaluated. The effect of one parameter i.e., exposure to UV or disinfectant, was also determined. According to the obtained results, the microbial load of a mature biofilm depended on the different species or dual species that had adhered to the surface, while the presence of other species could affect the biofilm population of a specific microbe (p < 0.05). The disinfectant strengthened the antimicrobial activity of UV, as, in most cases, the remaining biofilm population was below the detection limit of the method. Moreover, the presence of more than one species affected the resistance of the biofilm cells to UV and the disinfectant (p < 0.05). In conclusion, this study confirms that microbial interactions affected biofilm formation and decontamination, and it demonstrates the effectiveness of the surfactant with the photocatalytic TiO2 agent, suggesting that it could be an alternative agent with which to disinfect contaminated surfaces.}, }
@article {pmid37111423, year = {2023}, author = {Maione, A and Galdiero, E and Cirillo, L and Gambino, E and Gallo, MA and Sasso, FP and Petrillo, A and Guida, M and Galdiero, M}, title = {Prevalence, Resistance Patterns and Biofilm Production Ability of Bacterial Uropathogens from Cases of Community-Acquired Urinary Tract Infections in South Italy.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {4}, pages = {}, pmid = {37111423}, issn = {2076-0817}, abstract = {Community-acquired urinary tract infections represent the most common infectious diseases in the community setting. Knowing the antibiotic resistance patterns of uropathogens is crucial for establishing empirical treatment. The aim of the current study is to determine the incidence of the causative agents of UTIs and their resistance profiles. Patients of all ages and both sexes were enrolled in the study, and admitted to San Ciro Diagnostic Center in Naples between January 2019 and Jun 2020. Bacterial identification and antibiotic susceptibility testing were carried out using Vitek 2 system. Among the 2741 urine samples, 1702 (62.1%) and 1309 (37.9%) were negative and positive for bacterial growth, respectively. Of 1309 patients with infection, 760 (73.1%) were females and 279 (26.9%) were males. The greatest number of positive cases were found in the in the elderly (>61 years). Regarding uropathogens, 1000 (96.2%) were Gram-negative while 39 (3.8%) were Gram-positive strains. The three most isolated pathogenic strains were Escherichia coli (72.2%), Klebsiella pneumoniae (12.4%), and Proteus mirabilis (9.0%). Strong biofilm formation ability was observed in about 30% of the tested isolates. The low resistance rates recorded against nitrofurantoin, fosfomycin, piperacillin-tazobactam, and gentamicin could suggest them as the most appropriate therapies for CA-UTIs.}, }
@article {pmid37111322, year = {2023}, author = {Manoharadas, S and Ahmad, N and Altaf, M and Alrefaei, AF and Al-Rayes, BF}, title = {An Enzybiotic Cocktail Effectively Disrupts Preformed Dual Biofilm of Staphylococcus aureus and Enterococcus faecalis.}, journal = {Pharmaceuticals (Basel, Switzerland)}, volume = {16}, number = {4}, pages = {}, pmid = {37111322}, issn = {1424-8247}, abstract = {Multidrug-resistant bacterial infections are on the rise around the world. Chronic infections caused by these pathogens through biofilm mediation often complicate the situation. In natural settings, biofilms are often formed with different species of bacteria existing synergistically or antagonistically. Biofilms on diabetic foot ulcers are formed predominantly by two opportunistic pathogens, Staphylococcus aureus and Enterococcus faecalis. Bacteriophages and phage-based proteins, including endolysins, have been found to be active against biofilms. In this study, we evaluated the activity of two engineered enzybiotics either by themselves or as a combination against a dual biofilm formed by S. aureus and E. faecalis in an inert glass surface. An additive effect in rapidly disrupting the preformed dual biofilm was observed with the cocktail of proteins, in comparison with mono treatment. The cocktail-treated biofilms were dispersed by more than 90% within 3 h of treatment. Apart from biofilm disruption, bacterial cells embedded in the biofilm matrix were also effectively reduced by more than 90% within 3 h of treatment. This is the first instance where a cocktail of engineered enzybiotics has been effectively used to impede the structural integrity of a dual biofilm.}, }
@article {pmid37110446, year = {2023}, author = {Vanheuverzwijn, J and Maillard, EE and Mahat, A and Fowler, L and Monteyne, D and Bonnaud, L and Landercy, N and Hemberg, A and Janković, A and Meyer, F and Mišković-Stanković, V and Stevanović, M and Mirica, C and Pérez-Morga, D and Luginbuehl, R and Combes, C and Furtos, G and Fontaine, V}, title = {Easy, Flexible and Standardizable Anti-Nascent Biofilm Activity Assay to Assess Implant Materials.}, journal = {Microorganisms}, volume = {11}, number = {4}, pages = {}, doi = {10.3390/microorganisms11041023}, pmid = {37110446}, issn = {2076-2607}, abstract = {Medical implants have improved the quality of life of many patients. However, surgical intervention may eventually lead to implant microbial contamination. The aims of this research were to develop an easy, robust, quantitative assay to assess surface antimicrobial activities, especially the anti-nascent biofilm activity, and to identify control surfaces, allowing for international comparisons. Using new antimicrobial assays to assess the inhibition of nascent biofilm during persistent contact or after transient contact with bacteria, we show that the 5 cent Euro coin or other metal-based antibacterial coins can be used as positive controls, as more than 4 log reduction on bacterial survival was observed when using either S. aureus or P. aeruginosa as targets. The methods and controls described here could be useful to develop an easy, flexible and standardizable assay to assess relevant antimicrobial activities of new implant materials developed by industries and academics.}, }
@article {pmid37110385, year = {2023}, author = {Kang, MS and Park, GY and Lee, AR}, title = {In Vitro Preventive Effect and Mechanism of Action of Weissella cibaria CMU against Streptococcus mutans Biofilm Formation and Periodontal Pathogens.}, journal = {Microorganisms}, volume = {11}, number = {4}, pages = {}, doi = {10.3390/microorganisms11040962}, pmid = {37110385}, issn = {2076-2607}, abstract = {In this study, we evaluated the in vitro anti-biofilm, antibacterial, and anti-inflammatory activity of Weissella cibaria CMU (CMU), an oral probiotic, against periodontopathogens. Compared to other oral probiotics, CMU showed a superior inhibitory effect on the biofilm formation and growth of Streptococcus mutans on orthodontic wires and artificial teeth (p < 0.05). CMU exerted potent antibacterial effects against S. mutans and Porphyromonas gingivalis according to a line test. In human gingival fibroblasts (HGFs) stimulated by P. gingivalis, Fusobacterium nucleatum, or Prevotella intermedia, CMU suppressed the gene expression of pro-inflammatory cytokines [interleukin (IL)-6, IL-1β, IL-8, and tumor necrosis factor-α] in a dose-dependent manner (p < 0.05). CMU restored the production of the tissue inhibitor of metalloproteinase-1 following its inhibition by P. gingivalis, and it suppressed the expression of matrix metalloproteinase (MMP)-1 and -3 induced by periodontopathogens (p < 0.05). Moreover, CMU needed direct contact with HGFs to exert their anti-inflammatory function, indicating that they act directly on gingival cells to modulate local inflammation. Our preclinical study provides evidence for the potential benefits of topical CMU treatments in preventing the development of caries and periodontitis caused by the dysbiosis of the dental plaque microbiome.}, }
@article {pmid37110336, year = {2023}, author = {Elzahaby, DA and Farrag, HA and Haikal, RR and Alkordi, MH and Abdeltawab, NF and Ramadan, MA}, title = {Inhibition of Adherence and Biofilm Formation of Pseudomonas aeruginosa by Immobilized ZnO Nanoparticles on Silicone Urinary Catheter Grafted by Gamma Irradiation.}, journal = {Microorganisms}, volume = {11}, number = {4}, pages = {}, doi = {10.3390/microorganisms11040913}, pmid = {37110336}, issn = {2076-2607}, abstract = {Nosocomial infections caused by microbial biofilm formation on biomaterial surfaces such as urinary catheters are complicated by antibiotic resistance, representing a common problem in hospitalized patients. Therefore, we aimed to modify silicone catheters to resist microbial adherence and biofilm formation by the tested microorganisms. This study used a simple direct method to graft poly-acrylic acid onto silicone rubber films using gamma irradiation to endow the silicone surface with hydrophilic carboxylic acid functional groups. This modification allowed the silicone to immobilize ZnO nanoparticles (ZnO NPs) as an anti-biofilm. The modified silicone films were characterized by FT-IR, SEM, and TGA. The anti-adherence ability of the modified silicone films was evidenced by the inhibition of biofilm formation by otherwise strong biofilm-producing Gram-positive, Gram-negative, and yeast clinical isolates. The modified ZnO NPs grafted silicone showed good cytocompatibility with the human epithelial cell line. Moreover, studying the molecular basis of the inhibitory effect of the modified silicone surface on biofilm-associated genes in a selected Pseudomonas aeruginosa isolate showed that anti-adherence activity might be due to the significant downregulation of the expression of lasR, lasI, and lecB genes by 2, 2, and 3.3-fold, respectively. In conclusion, the modified silicone catheters were low-cost, offering broad-spectrum anti-biofilm activity with possible future applications in hospital settings.}, }
@article {pmid37110286, year = {2023}, author = {Ignatova, N and Abidullina, A and Streltsova, O and Elagin, V and Kamensky, V}, title = {Effect of pH, Norepinephrine and Glucose on Metabolic and Biofilm Activity of Uropathogenic Microorganisms.}, journal = {Microorganisms}, volume = {11}, number = {4}, pages = {}, doi = {10.3390/microorganisms11040862}, pmid = {37110286}, issn = {2076-2607}, abstract = {Urinary tract infection (UTIs) aremainly caused by a number of anatomical and physiological dysfunctions, but there are also some iatrogenic factors, including the use of certain medications, that contribute to the development of UTIs. The virulence of bacteria that colonize the urinary tract may be modified by pH and by the presence of soluble substances in urine, such as norepinephrine (NE) and glucose. In this work, we studied the influence of NE and glucose across a range of pHs (5, 7, 8) on the biomass, matrix production and metabolism of uropathogenic strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecalis. We used Congo red and gentian violet to stain the extracellular matrix and biomass, respectively, of biofilms. The optical density of staining of the biofilms was measured using a multichannel spectrophotometer. The metabolic activity was analyzed by MTT assay. It was shown that NE and glucose stimulate biomass production both in the Gram-negative and Gram-positive uropathogens. The metabolic activity in the presence of glucose was higher at pH 5 for E. coli (in 4.0 ± 0.1 times), Ps. aeruginosa (in 8.2 ± 0.2 times) and Kl. pneumoniae (in 4.1 ± 0.2 times). Matrix production of Kl. pneumoniae increased under NE (in 8.2 ± 0.2 times) and in the presence of glucose (in 1.5 ± 0.3 times). Thus, NE and glucose in urine may lead to persistent UTI under patient stress and in the case of metabolic glucose disorders.}, }
@article {pmid37109533, year = {2023}, author = {Amante, C and De Soricellis, C and Luccheo, G and Luccheo, L and Russo, P and Aquino, RP and Del Gaudio, P}, title = {Flogomicina: A Natural Antioxidant Mixture as an Alternative Strategy to Reduce Biofilm Formation.}, journal = {Life (Basel, Switzerland)}, volume = {13}, number = {4}, pages = {}, doi = {10.3390/life13041005}, pmid = {37109533}, issn = {2075-1729}, abstract = {The National Institute of Health has reported that approximately 80% of chronic infections are associated with biofilms, which are indicated as one of the main reasons for bacteria's resistance to antimicrobial agents. Several studies have revealed the role of N-acetylcysteine (NAC), in reducing biofilm formation induced by different microorganisms. A novel mixture made up of NAC and different natural ingredients (bromelain, ascorbic acid, Ribes nigrum, resveratrol, and pelargonium) has been developed in order to obtain a pool of antioxidants as an alternative strategy for biofilm reduction. The study has demonstrated that the mixture is able to significantly enhance NAC activity against different Gram-positive and Gram-negative bacteria. It has shown an increase in NAC permeation in vitro through an artificial fluid, moving from 2.5 to 8 μg/cm[2] after 30 min and from 4.4 to 21.6 μg/cm[2] after 180 min, and exhibiting a strongly fibrinolytic activity compared to the single components of the mixture. Moreover, this novel mixture has exhibited an antibiofilm activity against S aureus and the ability to reduce S. aureus growth by more than 20% in a time-killing assay, while on E. coli, and P. mirabilis, the growth was reduced by more than 80% compared to NAC. The flogomicina mixture has also been proven capable of reducing bacterial adhesion to abiotic surfaces of E.coli, by more than 11% concerning only the NAC. In combination with amoxicillin, it has been shown to significantly increase the drug's effectiveness after 14 days, offering a safe and natural way to reduce the daily dosage of antibiotics in prolonged therapies and consequently, reduce antibiotic resistance.}, }
@article {pmid37108414, year = {2023}, author = {Begić, G and Badovinac, IJ and Karleuša, L and Kralik, K and Cvijanovic Peloza, O and Kuiš, D and Gobin, I}, title = {Streptococcus salivarius as an Important Factor in Dental Biofilm Homeostasis: Influence on Streptococcus mutans and Aggregatibacter actinomycetemcomitans in Mixed Biofilm.}, journal = {International journal of molecular sciences}, volume = {24}, number = {8}, pages = {}, doi = {10.3390/ijms24087249}, pmid = {37108414}, issn = {1422-0067}, abstract = {A disturbed balance within the dental biofilm can result in the dominance of cariogenic and periodontopathogenic species and disease development. Due to the failure of pharmacological treatment of biofilm infection, a preventive approach to promoting healthy oral microbiota is necessary. This study analyzed the influence of Streptococcus salivarius K12 on the development of a multispecies biofilm composed of Streptococcus mutans, S. oralis and Aggregatibacter actinomycetemcomitans. Four different materials were used: hydroxyapatite, dentin and two dense polytetrafluoroethylene (d-PTFE) membranes. Total bacteria, individual species and their proportions in the mixed biofilm were quantified. A qualitative analysis of the mixed biofilm was performed using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results showed that in the presence of S. salivarius K 12 in the initial stage of biofilm development, the proportion of S. mutans was reduced, which resulted in the inhibition of microcolony development and the complex three-dimensional structure of the biofilm. In the mature biofilm, a significantly lower proportion of the periodontopathogenic species A. actinomycetemcomitans was found in the salivarius biofilm. Our results show that S. salivarius K 12 can inhibit the growth of pathogens in the dental biofilm and help maintain the physiological balance in the oral microbiome.}, }
@article {pmid37107116, year = {2023}, author = {Tomé, AR and Carvalho, FM and Teixeira-Santos, R and Burmølle, M and Mergulhão, FJM and Gomes, LC}, title = {Use of Probiotics to Control Biofilm Formation in Food Industries.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {4}, pages = {}, doi = {10.3390/antibiotics12040754}, pmid = {37107116}, issn = {2079-6382}, abstract = {Microorganisms tend to adhere to food contact surfaces and form biofilms, which serve as reservoirs for bacteria that can contaminate food. As part of a biofilm, bacteria are protected from the stressful conditions found during food processing and become tolerant to antimicrobials, including traditional chemical sanitisers and disinfectants. Several studies in the food industry have shown that probiotics can prevent attachment and the consequent biofilm formation by spoilage and pathogenic microorganisms. This review discusses the most recent and relevant studies on the effects of probiotics and their metabolites on pre-established biofilms in the food industry. It shows that the use of probiotics is a promising approach to disrupt biofilms formed by a large spectrum of foodborne microorganisms, with Lactiplantibacillus and Lacticaseibacillus being the most tested genera, both in the form of probiotic cells and as sources of cell-free supernatant. The standardisation of anti-biofilm assays for evaluating the potential of probiotics in biofilm control is of extreme importance, enabling more reliable, comparable, and predictable results, thus promoting significant advances in this field.}, }
@article {pmid37107000, year = {2023}, author = {Tian, C and Yuan, M and Tao, Q and Xu, T and Liu, J and Huang, Z and Wu, Q and Pan, Y and Zhao, Y and Zhang, Z}, title = {Discovery of Novel Resistance Mechanisms of Vibrio parahaemolyticus Biofilm against Aminoglycoside Antibiotics.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {4}, pages = {}, doi = {10.3390/antibiotics12040638}, pmid = {37107000}, issn = {2079-6382}, abstract = {Inappropriate use of antibiotics eventually leads to the emergence of antibiotic-resistant strains and invalidates the treatment of infectious diseases. Aminoglycoside antibiotics (AGAs) are a class of broad-spectrum cationic antibiotics widely used for the treatment of Gram-negative bacterial infections. Understanding the AGA resistance mechanism of bacteria would increase the efficacy of treating these infections. This study demonstrates a significant correlation between AGA resistance and the adaptation of biofilms by Vibrio parahaemolyticus (VP). These adaptations were the result of challenges against the aminoglycosides (amikacin and gentamicin). Confocal laser scanning microscope (CLSM) analysis revealed an enclosure type mechanism where the biological volume (BV) and average thickness (AT) of V. parahaemolyticus biofilm were significantly positively correlated with amikacin resistance (BIC) (p < 0.01). A neutralization type mechanism was mediated by anionic extracellular polymeric substances (EPSs). The biofilm minimum inhibitory concentrations of amikacin and gentamicin were reduced from 32 µg/mL to 16 µg/mL and from 16 µg/mL to 4 µg/mL, respectively, after anionic EPS treatment with DNase I and proteinase K. Here, anionic EPSs bind cationic AGAs to develop antibiotic resistance. Transcriptomic sequencing revealed a regulatory type mechanism, where antibiotic resistance associated genes were significantly upregulated in biofilm producing V. parahaemolyticus when compared with planktonic cells. The three mechanistic strategies of developing resistance demonstrate that selective and judicious use of new antibiotics are needed to win the battle against infectious disease.}, }
@article {pmid37106905, year = {2023}, author = {Afonso, AC and Sousa, M and Pinto, AR and Cotovio, M and Simões, M and Saavedra, MJ}, title = {Biofilm Production by Critical Antibiotic-Resistant Pathogens from an Equine Wound.}, journal = {Animals : an open access journal from MDPI}, volume = {13}, number = {8}, pages = {}, doi = {10.3390/ani13081342}, pmid = {37106905}, issn = {2076-2615}, abstract = {As in human medicine, in veterinary medicine, chronic wounds are often related to polymicrobial infections and the presence of a biofilm, which compromises the effectiveness of therapeutic approaches. In this study, a Lusitano mare presented a 21-day-old chronic wound that was only being treated with an antiseptic. A swab sample was collected, and three isolates of Staphylococcus aureus and one of Pseudomonas aeruginosa were isolated. S. aureus did not show resistance to a panel of antibiotics. However, the P. aeruginosa isolate showed a resistance profile to carbapenems and fluoroquinolones, which may suggest a cross-resistance between antiseptic and antibiotics, given that no antibiotic therapy was applied to the wound or the mare in the previous year. Further experiments were conducted to assess the ability of the isolates to form biofilms, and to ascertain their susceptibility to gentamicin. The results demonstrated that the isolates produced biofilms. Gentamicin at the minimum inhibitory concentration (MIC) and 10× MIC caused biofilm removal between 59.3% and 85.7%, with the highest removal percentage being obtained for the P. aeruginosa isolate (at 10× MIC concentration). This study reveals that an equine wound was colonized by antibiotic resistant bacteria, and that all the wound colonizers could form biofilms, demonstrating the relevance of an adequate diagnosis and treatment when there is a suspicion of a biofilm-infected wound. It also highlights the possibility of resistance transmission between animals, animals and humans, or animals and the environment.}, }
@article {pmid37105262, year = {2023}, author = {Cui, H and Zhang, L and Zhang, Q and Li, X and Peng, Y and Wang, C}, title = {Enhancing nitrogen removal of carbon-limited municipal wastewater in step-feed biofilm batch reactor through integration of anammox.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {129091}, doi = {10.1016/j.biortech.2023.129091}, pmid = {37105262}, issn = {1873-2976}, abstract = {The biological nitrogen removal of municipal wastewater was successfully improved by integrating anammox in a step-feed sequencing biofilm batch reactor. Despite fluctuating influent carbon to nitrogen ratio (1.9-5.1) and decreasing temperature (24.1-16.3 ℃), nitrogen removal efficiency of 95.9±1.4 % and nitrogen removal rate of 0.23±0.02 kg N/(m[3]·d) were successfully maintained without requirement of external carbon sources. The advanced removal performance was mainly attributed to the enhanced anammox. Anammox bacteria presented a high relative abundance (42.9% in biofilms, 1.5% in flocs) and anammox activity was as high as 5.42±0.12 mg N/(g volatile suspended solids·h). Further analysis suggested that flexible control of influent organic and ammonium through step-feeding could provide multiple substrate supply for anammox reaction, potentially resulting in stable combination of anammox with hybrid-nitrite-shunt processes. Overall, this study provides a promising anammox-related application with simple-control step-feed strategy for enhanced and stable nitrogen removal from carbon-limited municipal wastewater.}, }
@article {pmid37105205, year = {2023}, author = {Ma, Y and Aung, TT and Lakshminarayanan, R and Chua, SL}, title = {Biofilm formation and virulence potential of carbapenem-resistant Pseudomonas aeruginosa.}, journal = {The Lancet. Microbe}, volume = {}, number = {}, pages = {}, doi = {10.1016/S2666-5247(23)00097-6}, pmid = {37105205}, issn = {2666-5247}, }
@article {pmid37104940, year = {2023}, author = {Hewawaduge, C and Senevirathne, A and Sivasankar, C and Lee, JH}, title = {The impact of lipid A modification on biofilm and related pathophysiological phenotypes, endotoxicity, immunogenicity, and protection of Salmonella Typhimurium.}, journal = {Veterinary microbiology}, volume = {282}, number = {}, pages = {109759}, doi = {10.1016/j.vetmic.2023.109759}, pmid = {37104940}, issn = {1873-2542}, abstract = {This study presents the engineering of a less endotoxic Salmonella Typhimurium strain by manipulating the lipid-A structure of the lipopolysaccharide (LPS) component. Salmonella lipid A was dephosphorylated by using lpxE from Francisella tularensis. The 1-phosphate group from lipid-A was removed selectively, resulting in a close analog of monophosphoryl lipid A. We observed a significant impact of ∆pagL on major virulence factors such as biofilm formation, motility, persistency, and immune evasion. In correlation with biofilm and motility retardation, adhesion and invasion were elevated but with reduced intracellular survival, a favorable phenotype prospect of a vaccine strain. Western blotting and silver staining confirmed the absence of the O-antigen and truncated lipid-A core in the detoxified Salmonella mutant. In vitro and in vivo studies demonstrated that the dephosphorylated Salmonella mutant mediated lower pro-inflammatory cytokine secretion than the wild-type strain. The vaccine strains were present in the spleen and liver for five days and were cleared from the organs by day seven. However, the wild-type strain persisted in the spleen, liver, and brain, leading to sepsis-induced death. Histological evaluations of tissue samples further confirmed the reduced endotoxic activity of the detoxified Salmonella mutant. The detoxification strategy did not compromise the level of protective immunity, as the vaccine strain could enhance humoral and cellular immune responses and protect against the wild-type challenge in immunized mice.}, }
@article {pmid37103266, year = {2023}, author = {Dede, M and Basche, S and Neunzehn, J and Dannemann, M and Hannig, C and Kühne, MT}, title = {Efficacy of Endodontic Disinfection Protocols in an E. faecalis Biofilm Model-Using DAPI Staining and SEM.}, journal = {Journal of functional biomaterials}, volume = {14}, number = {4}, pages = {}, doi = {10.3390/jfb14040176}, pmid = {37103266}, issn = {2079-4983}, abstract = {The aim of this study was to investigate the antimicrobial efficacy of different disinfection protocols in a novel Enterococcus faecalis biofilm model based on a visualization method and to evaluate the potential alteration of dentinal surface. A total of 120 extracted human premolars were allocated to 6 groups with different irrigation protocols. The assessment of the effectiveness of each protocol and the alteration of dentinal surface were visualized by using SEM and fluorescence microscopy (DAPI). A dense E. faecalis biofilm with a penetration depth of 289 μm (medial part of the root canal) and 93 μm (apical part) validated that the biofilm model had been successfully implemented. A significant difference between the 3% NaOCl groups and all the other groups in both observed parts of the root canal (p < 0.05) was detected. However, the SEM analysis revealed that the dentinal surface in the 3% NaOCl groups was severely altered. The established biofilm model and the visualization method based on DAPI are appropriate for bacterial quantification and evaluation of the depth effect of different disinfection protocols in the root canal system. The combination of 3% NaOCl with 20% EDTA or MTAD with PUI allows the decontamination of deeper dentine zones within the root canal but simultaneously alters the dentinal surface.}, }
@article {pmid37100298, year = {2023}, author = {Svendsen, S and Rebien Jørgensen, L and Liang, C and Carvalho, PN and Bendix Larsen, S and Bester, K}, title = {Mechanistic studies on the effect of easy degradable carbon on pharmaceuticals removal in intermittently fed Moving Bed Biofilm Reactors.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {129084}, doi = {10.1016/j.biortech.2023.129084}, pmid = {37100298}, issn = {1873-2976}, abstract = {This study was conducted to provide for the first time systematic data on how intermittent feeding with carbon (ethanol) affects the kinetics of pharmaceuticals degradation in a moving bed biofilm reactor (MBBR). The relationship between the degradation rate constants (K) of 36 pharmaceuticals and the length of famine was tested with 12 different feast-famine ratios: For 17 pharmaceuticals, intermittent feeding increased K with a factor of 3-17, while for six other pharmaceuticals, it decreased K. Concerning intermittent loading, three dependencies were detected: 1) for some compounds (e.g., valsartan, ibuprofen, iohexol), the K decreased linearly with carbon loading, 2) for three compounds (2 sulfonamides and benzotriazole) K increased linearly with carbon loading 3) for most compounds (e.g., beta blockers, macrocyclic antibiotics, candesartan, citalopram, clindamycin, gabapentin) K had a maximum around 6 d famine (with 2 d feast). Optimizing processes on MBBRs need therefore be conducted based on a prioritization of compounds.}, }
@article {pmid37100294, year = {2023}, author = {Zhu, L and Ma, J and Yuan, H and Deng, L and Shi, Z and He, Q and Ke, S}, title = {Effects of successional sulfadiazine exposure on biofilm in moving bed biofilm reactor: secretion of extracellular polymeric substances, community activity and functional gene expression.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {129092}, doi = {10.1016/j.biortech.2023.129092}, pmid = {37100294}, issn = {1873-2976}, abstract = {The effects of sulfadiazine (SDZ) on responses of biofilm in a moving bed biofilm reactor were explored with emphasis on the changes in extracellular polymeric substances (EPS) and functional genes. It was found that 3 to 10 mg/L SDZ reduced the protein (PN) and polysaccharide (PS) contents of EPS by 28.7%-55.1% and 33.3%-61.4%, respectively. The EPS maintained high ratio of PN to PS (10.3-15.1), and the major functional groups within EPS remained unaffected to SDZ. Bioinformatics analysis showed that SDZ significantly altered the community activity such as increased expression of s_Alcaligenes faecali. Totally, the biofilm held high SDZ removal rates, which were ascribed to the self-protection by secreted EPS, and genes levels upregulation of antibiotic resistance and transporter protein. Collectively, this study provides more details on the biofilm community exposure to an antibiotic and highlights the role of EPS and functional genes in antibiotic removal.}, }
@article {pmid37100251, year = {2023}, author = {Wei, T and Wang, Z and Yang, Y and Xiang, W and Liu, Y and Wu, B and Cui, X and Guo, B and Zhou, Y}, title = {Microbial niches and dynamics of antibiotic resistance genes in a bio-enhanced granular-activated carbon biofilm treating greywater.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138774}, doi = {10.1016/j.chemosphere.2023.138774}, pmid = {37100251}, issn = {1879-1298}, abstract = {Accumulation and transmission of antibiotic resistance genes (ARGs) in greywater treatment systems present risks for its reuse. In this study, a gravity flow self-supplying oxygen (O2) bio-enhanced granular activated carbon dynamic biofilm reactor (BhGAC-DBfR) was developed to treat greywater. Maximum removal efficiencies were achieved at saturated/unsaturated ratios (RSt/Ust) of 1:1.1 for chemical oxygen demand (97.6 ± 1.5%), linear alkylbenzene sulfonates (LAS) (99.2 ± 0.5%), NH+ 4-N (99.3 ± 0.7%) and total nitrogen (85.3 ± 3.2%). Microbial communities were significantly different at various RSt/Ust and reactor positions (P < 0.05). The unsaturated zone with low RSt/Ust showed more abundant microorganisms than the saturated zone with high RSt/Ust. The reactor-top community was predominant by aerobic nitrification (Nitrospira) and LAS biodegradation (Pseudomonas, Rhodobacter and Hydrogenophaga) related genera; but reactor-bottom community was predominant by anaerobic denitrification and organics removal related genera (Dechloromonas and Desulfovibrio). Most of the ARGs (e.g., intI-1, sul1, sul2 and korB) were accumulated in the biofilm, which were closely associated with microbial communities at reactor top and stratification. The saturated zone can achieve over 80% removal of the tested ARGs at all operation Phases. Results suggested that BhGAC-DBfR can provide assistance in blocking the environment dissemination of ARGs during greywater treatment.}, }
@article {pmid37099227, year = {2023}, author = {Araújo, D and Gonçalves, B and Vilas Boas, D and Rodrigues, ME and Henriques, M and Silva, S}, title = {Combined Application of Antisense Oligomers to Control Transcription Factors of Candida albicans Biofilm Formation.}, journal = {Mycopathologia}, volume = {}, number = {}, pages = {}, pmid = {37099227}, issn = {1573-0832}, abstract = {Antisense oligomers (ASOs) have been little exploited to control determinants of Candida albicans virulence. Biofilm formation is an important virulence factor of C. albicans, that is regulated by a complex network of transcription factors (such as EFG1, BRG1 and ROB1). Thus, the main goal of this work was to project ASOs, based on the 2'-OMethyl chemical modification, to target BRG1 and ROB1 mRNA and to validate its application either alone or in combination with the EFG1 mRNA target, to reduce C. albicans biofilm formation. The ability of ASOs to control gene expression was evaluate by qRT-PCR. The effect on biofilm formation was determined by the total biomass quantification, and simultaneously the carbohydrates and proteins reduction on extracellular matrix. It was verified that all the oligomers were able to reduce the levels of gene expression and the ability of C. albicans to form biofilms. Furthermore, the combined application of the cocktail of ASOs enhances the inhibition of C. albicans biofilm formation, minimizing biofilm thickness by reducing the quantity of matrix content (protein and carbohydrate). So, our work confirms that ASOs are useful tools for research and therapeutic development on the control of Candida species biofilm formation.}, }
@article {pmid37098964, year = {2023}, author = {Kaleta, MF and Sauer, K}, title = {MoaB1 Homologs Contribute to Biofilm Formation and Motility by Pseudomonas aeruginosa and Escherichia coli.}, journal = {Journal of bacteriology}, volume = {}, number = {}, pages = {e0000423}, doi = {10.1128/jb.00004-23}, pmid = {37098964}, issn = {1098-5530}, abstract = {moaB homologs, encoding the molybdopterin biosynthetic protein B1, have been reported to be expressed under anoxic conditions and during biofilm growth in various microorganisms; however, little is known about MoaB's function. Here, we demonstrate that in Pseudomonas aeruginosa, MoaB1 (PA3915) contributes to biofilm-related phenotypes. Specifically, moaB1 expression is induced in biofilms, and insertional inactivation of moaB1 reduced biofilm biomass accumulation and pyocyanin production while enhancing swarming motility, and pyoverdine abundance without affecting attachment, swimming motility, or c-di-GMP levels. Inactivation of the highly conserved E. coli homolog of moaB1, moaBEc, likewise coincided with reduced biofilm biomass accumulation. In turn, heterologous expression of moaBEc restored biofilm formation and swarming motility by the P. aeruginosa moaB1 mutant to wild-type levels. Moreover, MoaB1 was found to interact with other conserved biofilm-associated proteins, PA2184 and PA2146, as well as the sensor-kinase SagS. However, despite the interaction, MoaB1 failed to restore SagS-dependent expression of brlR encoding the transcriptional regulator BrlR, and inactivation of moaB1 or moaBEc had no effect on the antibiotic susceptibility phenotype of biofilms formed by P. aeruginosa and E. coli, respectively. While our findings did not establish a link between MoaB1 and molybdenum cofactor biosynthesis, they suggest that MoaB1 homologs contribute to biofilm-associated phenotypes across species boundaries, possibly hinting at the existence of a previously undescribed conserved biofilm pathway. IMPORTANCE Proteins contributing to the biogenesis of molybdenum cofactors have been characterized; however, the role of the molybdopterin biosynthetic protein B1 (MoaB1) has remained elusive, and solid evidence to support its role in biosynthesis of molybdenum cofactor is lacking. Here, we demonstrate that, in Pseudomonas aeruginosa, MoaB1 (PA3915) contributes to biofilm-related phenotypes in a manner that does not support a role of MoaB1 in the biosynthesis of molybdenum cofactors.}, }
@article {pmid37098957, year = {2023}, author = {Reichhardt, C}, title = {The Pseudomonas aeruginosa Biofilm Matrix Protein CdrA Has Similarities to Other Fibrillar Adhesin Proteins.}, journal = {Journal of bacteriology}, volume = {}, number = {}, pages = {e0001923}, doi = {10.1128/jb.00019-23}, pmid = {37098957}, issn = {1098-5530}, abstract = {The ability of bacteria to adhere to each other and both biotic and abiotic surfaces is key to biofilm formation, and one way that bacteria adhere is using fibrillar adhesins. Fibrillar adhesins share several key characteristics, including (i) they are extracellular, surface-associated proteins, (ii) they contain an adhesive domain as well as a repetitive stalk domain, and (iii) they are either a monomer or homotrimer (i.e., identical, coiled-coil) of a high molecular weight protein. Pseudomonas aeruginosa uses the fibrillar adhesin called CdrA to promote bacterial aggregation and biofilm formation. Here, the current literature on CdrA is reviewed, including its transcriptional and posttranslational regulation by the second messenger c-di-GMP as well as what is known about its structure and ability to interact with other molecules. I highlight its similarities to other fibrillar adhesins and discuss open questions that remain to be answered toward a better understanding of CdrA.}, }
@article {pmid37098898, year = {2023}, author = {Razvi, E and DiFrancesco, BR and Wasney, GA and Morrison, ZA and Tam, J and Auger, A and Baker, P and Alnabelseya, N and Rich, JD and Sivarajah, P and Whitfield, GB and Harrison, JJ and Melnyk, RA and Nitz, M and Howell, PL}, title = {Small Molecule Inhibition of an Exopolysaccharide Modification Enzyme is a Viable Strategy To Block Pseudomonas aeruginosa Pel Biofilm Formation.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0029623}, doi = {10.1128/spectrum.00296-23}, pmid = {37098898}, issn = {2165-0497}, abstract = {Biosynthesis of the Pel exopolysaccharide in Pseudomonas aeruginosa requires all seven genes of the pelABCDEFG operon. The periplasmic modification enzyme PelA contains a C-terminal deacetylase domain that is necessary for Pel-dependent biofilm formation. Herein, we show that extracellular Pel is not produced by a P. aeruginosa PelA deacetylase mutant. This positions PelA deacetylase activity as an attractive target to prevent Pel-dependent biofilm formation. Using a high-throughput screen (n = 69,360), we identified 56 compounds that potentially inhibit PelA esterase activity, the first enzymatic step in the deacetylase reaction. A secondary biofilm inhibition assay identified methyl 2-(2-pyridinylmethylene) hydrazinecarbodithioate (SK-017154-O) as a specific Pel-dependent biofilm inhibitor. Structure-activity relationship studies identified the thiocarbazate as a necessary functional group and that the pyridyl ring could be replaced with a phenyl substituent (compound 1). Both SK-017154-O and compound 1 inhibit Pel-dependent biofilm formation in Bacillus cereus ATCC 10987, which has a predicted extracellular PelA deacetylase in its pel operon. Michaelis-Menten kinetics determined SK-017154-O to be a noncompetitive inhibitor of PelA, while compound 1 did not directly inhibit PelA esterase activity. Cytotoxicity assays using human lung fibroblast cells showed that compound 1 is less cytotoxic than SK-017154-O. This work provides proof of concept that biofilm exopolysaccharide modification enzymes are important for biofilm formation and can serve as useful antibiofilm targets. IMPORTANCE Present in more than 500 diverse Gram-negative and 900 Gram-positive organisms, the Pel polysaccharide is one of the most phylogenetically widespread biofilm matrix determinants found to date. Partial de-N-acetylation of this α-1,4 linked N-acetylgalactosamine polymer by the carbohydrate modification enzyme PelA is required for Pel-dependent biofilm formation in Pseudomonas aeruginosa and Bacillus cereus. Given this and our observation that extracellular Pel is not produced by a P. aeruginosa PelA deactylase mutant, we developed an enzyme-based high-throughput screen and identified methyl 2-(2-pyridinylmethylene) hydrazinecarbodithioate (SK-017154-O) and its phenyl derivative as specific Pel-dependent biofilm inhibitors. Michaelis-Menten kinetics revealed SK-017154-O is a noncompetitive inhibitor and that its noncytotoxic, phenyl derivative does not directly inhibit P. aeruginosa PelA esterase activity. We provide proof of concept that exopolysaccharide modification enzymes can be targeted with small molecule inhibitors to block Pel-dependent biofilm development in both Gram-negative and Gram-positive bacteria.}, }
@article {pmid37098889, year = {2023}, author = {Jin, X and Luan, X and Xie, F and Chang, W and Lou, H}, title = {Erg6 Acts as a Downstream Effector of the Transcription Factor Flo8 To Regulate Biofilm Formation in Candida albicans.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0039323}, doi = {10.1128/spectrum.00393-23}, pmid = {37098889}, issn = {2165-0497}, abstract = {The yeast-to-hyphal morphotype transition and subsequent biofilm formation are important virulence factors of Candida albicans and are closely associated with ergosterol biosynthesis. Flo8 is an important transcription factor that determines filamentous growth and biofilm formation in C. albicans. However, the relationship between Flo8 and regulation of the ergosterol biosynthesis pathway remains elusive. Here, we analyzed the sterol composition of a flo8-deficient C. albicans strain by gas chromatography-mass spectrometry and observed the accumulation of the sterol intermediate zymosterol, the substrate of Erg6 (C-24 sterol methyltransferase). Accordingly, the transcription level of ERG6 was reduced in the flo8-deficient strain. Yeast one-hybrid experiments revealed that Flo8 physically interacted with the ERG6 promoter. Ectopic overexpression of ERG6 in the flo8-deficient strain partially restored biofilm formation and in vivo virulence in a Galleria mellonella infection model. These findings suggest that Erg6 is a downstream effector of the transcription factor Flo8 that mediates the cross talk between sterol synthesis and virulence factors in C. albicans. IMPORTANCE Biofilm formation by C. albicans hinders its eradication by immune cells and antifungal drugs. Flo8 is an important morphogenetic transcription factor that regulates the biofilm formation and in vivo virulence of C. albicans. However, little is known about how Flo8 regulates biofilm formation and fungal pathogenicity. Here, we determined that Flo8 directly binds to the promoter of ERG6 to positively regulate its transcriptional expression. Consistently, loss of flo8 results in the accumulation of the substrate of Erg6. Moreover, ectopic overexpression of ERG6 at least partially restores the biofilm formation and virulence of the flo8-deficient strain both in vitro and in vivo. This work provides a new perspective on the metabolic link between transcription factors and morphotypes in C. albicans.}, }
@article {pmid37098583, year = {2023}, author = {Goswami, AG and Basu, S and Banerjee, T and Shukla, VK}, title = {Biofilm and wound healing: from bench to bedside.}, journal = {European journal of medical research}, volume = {28}, number = {1}, pages = {157}, pmid = {37098583}, issn = {2047-783X}, abstract = {The bubbling community of microorganisms, consisting of diverse colonies encased in a self-produced protective matrix and playing an essential role in the persistence of infection and antimicrobial resistance, is often referred to as a biofilm. Although apparently indolent, the biofilm involves not only inanimate surfaces but also living tissue, making it truly ubiquitous. The mechanism of biofilm formation, its growth, and the development of resistance are ever-intriguing subjects and are yet to be completely deciphered. Although an abundance of studies in recent years has focused on the various ways to create potential anti-biofilm and antimicrobial therapeutics, a dearth of a clear standard of clinical practice remains, and therefore, there is essentially a need for translating laboratory research to novel bedside anti-biofilm strategies that can provide a better clinical outcome. Of significance, biofilm is responsible for faulty wound healing and wound chronicity. The experimental studies report the prevalence of biofilm in chronic wounds anywhere between 20 and 100%, which makes it a topic of significant concern in wound healing. The ongoing scientific endeavor to comprehensively understand the mechanism of biofilm interaction with wounds and generate standardized anti-biofilm measures which are reproducible in the clinical setting is the challenge of the hour. In this context of "more needs to be done", we aim to explore various effective and clinically meaningful methods currently available for biofilm management and how these tools can be translated into safe clinical practice.}, }
@article {pmid37098362, year = {2023}, author = {Shitu, A and Chen, W and Tadda, MA and Zhang, Y and Ye, Z and Liu, D and Zhu, S and Zhao, J}, title = {Enhanced aquaculture wastewater treatment in a biofilm reactor filled with sponge/ferrous oxalate/biochar composite (Sponge-C2FeO4@NBC) biocarriers: Performance and mechanism.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138772}, doi = {10.1016/j.chemosphere.2023.138772}, pmid = {37098362}, issn = {1879-1298}, abstract = {Fabricating low-cost and efficient biofilm carriers for moving bed biofilm reactors in wastewater treatment is crucial for achieving environmental sustainability. Herein, a novel sponge biocarrier doped with NaOH-loaded biochar and nano ferrous oxalate (sponge-C2FeO4@NBC) was prepared and evaluated for nitrogenous compounds removal from recirculating aquaculture systems (RAS) wastewater by stepwise increasing ammonium nitrogen (NH4[+]-N) loading rates. The prepared NBC, sponge-C2FeO4@NBC and matured biofilms were characterized using SEM, FTIR, BET, and N2 adsorption-desorption techniques. The results reveal that the highest removal rates of NH4[+]-N reached 99.28 ± 1.3% was yielded by the bioreactor filled with sponge-C2FeO4@NBC, with no obvious nitrite (NO2[-]-N) accumulation in the final phase. The reactor packed with sponge-C2FeO4@NBC biocarrier had the highest relative abundance of functional microorganisms responsible for nitrogen metabolism than in the control reactor, confirmed from 16S rRNA gene sequencing analysis. Our study provides new insights into the newly developed biocarriers for enhancing RAS biofilters treatment performance in keeping water quality within the acceptable level for the rearing of aquatic species.}, }
@article {pmid37097921, year = {2023}, author = {Shastry, RP and Abhinand, CS}, title = {Targeting the Pseudomonas aeruginosa quorum sensing system to inhibit virulence factors and eradicate biofilm formation using AHL-analogue phytochemicals.}, journal = {Journal of biomolecular structure &amp; dynamics}, volume = {}, number = {}, pages = {1-10}, doi = {10.1080/07391102.2023.2202270}, pmid = {37097921}, issn = {1538-0254}, abstract = {Quorum sensing plays a major role in the expression of virulence and development of biofilm in the human pathogen Pseudomonas aeruginosa. Natural compounds are well-known for their antibacterial characteristics by blocking various metabolic pathways. The goal of this study is to find natural compounds that mimic AHL (Acyl homoserine lactone) and suppress virulence in P. aeruginosa, which is triggered by quorum sensing-dependent pathways as an alternative drug development strategy. To support this rationale, functional network analysis and in silico investigations were carried out to find natural AHL analogues, followed by molecular docking studies. Out of the 16 top-hit AHL analogues derived from phytochemicals, seven ligands were found to bind to the quorum sensing activator proteins. Cassialactone, an AHL analogue, exhibited the highest binding affinity for RhlI, RhlR, and PqsE of P. aeruginosa, with a docking score of -9.4, -8.9, and -8.7 kcal/mol, respectively. 2(5H)-Furanone, a well-known inhibitor, was also docked to compare the docking score and intermolecular interactions between the ligand and the target protein. Furthermore, molecular dynamics simulations and binding free energy calculations were performed to determine the stability of the docked complexes. Additionally, the ADME properties of the analogues were also analyzed to evaluate the pharmacological parameters. Functional network analysis further showed that the interconnectedness of proteins such as RhlI, RhlR, LasI, and PqsE with the virulence and biofilm phenotype of the pathogen could offer potential as a therapeutic target.Communicated by Ramaswamy H. Sarma.}, }
@article {pmid37097592, year = {2023}, author = {Paul, P and Roy, R and Das, S and Sarkar, S and Chatterjee, S and Mallik, M and Shukla, A and Chakraborty, P and Tribedi, P}, title = {The combinatorial applications of 1,4-naphthoquinone and tryptophan inhibit the biofilm formation of Staphylococcus aureus.}, journal = {Folia microbiologica}, volume = {}, number = {}, pages = {}, pmid = {37097592}, issn = {1874-9356}, abstract = {Microorganisms embedded within an extracellular polymeric matrix are known as biofilm. The extensive use of antibiotics to overcome the biofilm-linked challenges has led to the emergence of multidrug-resistant strains. Staphylococcus aureus is one such nosocomial pathogen that is known to cause biofilm-linked infections. Thus, novel strategies have been adopted in this study to inhibit the biofilm formation of S. aureus. Two natural compounds, namely, 1,4-naphthoquinone (a quinone derivative) and tryptophan (aromatic amino acid), have been chosen as they could independently show efficient antibiofilm activity. To enhance the antibiofilm potential, the two compounds were combined and tested against the same organism. Several experiments like crystal violet (CV) assay, protein estimation, extracellular polymeric substance (EPS) extraction, and estimation of metabolic activity confirmed that the combination of the two compounds could significantly inhibit the biofilm formation of S. aureus. To comprehend the underlying mechanism, efforts were further directed to understand whether the two compounds could inhibit biofilm formation by compromising the cell surface hydrophobicity of the bacteria. The results revealed that the cell surface hydrophobicity got reduced by ~ 49% when the compounds were applied together. Thus, the combinations could show enhanced antibiofilm activity by attenuating cell surface hydrophobicity. Further studies revealed that the selected concentrations of the compounds could disintegrate (~ 70%) the pre-existing biofilm of the test bacteria without showing any antimicrobial activity. Hence, the combined application of tryptophan and 1,4-naphthoquinone could be used to inhibit the biofilm threats of S. aureus.}, }
@article {pmid37097401, year = {2023}, author = {Sun, N and Jiang, X and Meng, Q and Jiang, H and Yuan, Z and Zhang, J}, title = {Preparation of Nanoparticles Loaded with Quercetin and Effects on Bacterial Biofilm and LPS-Induced Oxidative Stress in Dugesia japonica.}, journal = {Applied biochemistry and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {37097401}, issn = {1559-0291}, abstract = {Quercetin is a kind of flavonol compound, which has been widely concerned because of its good pharmacological effects. However, its poor water solubility and poor oral absorption limit its application. To address the above problems, the optimal technological conditions for preparing quercetin-loaded chitosan sodium alginate nanoparticles (Q-CSNPs) were obtained through single-factor experiment method. Q-CSNPs were characterized by particle size analyzer, scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FTIR). Biofilm experiment evaluated the antibacterial activity of five different concentrations of Q-CSNPs against Escherichia coli and Staphylococcus aureus. DPPH and hydroxyl radical scavenging experiments determined their antioxidant activity. The effect of Q-CSNPs labeled with FITC on the oxidative stress of planarian was determined. The results showed that quercetin was successfully encapsulated and had good antibacterial and antioxidant capacity in vitro. In vivo experiments of planarians also showed that Q-CSNPs could inhibit the oxidative stress induced by lipopolysaccharide (LPS) and especially alleviate the decrease of CAT activity and the increase of MDA content in planarians induced by LPS. After being supported by future in vivo studies, this preparation will provide research possibilities for the development of quercetin nano-drugs, quercetin dietary supplement, and so on.}, }
@article {pmid37096639, year = {2023}, author = {Chen, K and Zhu, Y and Su, H and Jiang, H and Liu, X}, title = {Modified Zhibai Dihuang pill alleviated urinary tract infection induced by extended-spectrum β-lactamase Escherichia coli in rats by regulating biofilm formation.}, journal = {Pharmaceutical biology}, volume = {61}, number = {1}, pages = {674-682}, doi = {10.1080/13880209.2023.2199786}, pmid = {37096639}, issn = {1744-5116}, mesh = {Rats ; Animals ; Escherichia coli ; *Escherichia coli Infections/drug therapy/microbiology ; beta-Lactamases/genetics/metabolism ; Rats, Sprague-Dawley ; *Urinary Tract Infections/drug therapy/microbiology ; Biofilms ; Anti-Bacterial Agents/pharmacology ; }, abstract = {CONTEXT: Zhibai Dihuang pill (ZD), a traditional Chinese medicine nourishes Yin and reduces internal heat, is believed to have therapeutic effects on urinary tract infections (UTIs).<br><br>OBJECTIVE: To explore the effects and mechanism of modified ZD (MZD) on UTI induced by extended-spectrum &#x3b2;-lactamase (ESBLs) Escherichia coli.<br><br>MATERIALS AND METHODS: Thirty Sprague-Dawley rats were randomly divided into control, model (0.5&#x2009;mL 1.5&#x2009;&#xd7;&#x2009;10[8] CFU/mL ESBLs E. coli), MZD (20&#x2009;g/kg MZD), LVFX (0.025&#x2009;g/kg LVFX), and MZD&#x2009;+&#x2009;LVFX groups (20&#x2009;g/kg MZD + 0.025&#x2009;g/kg LVFX), n&#x2009;=&#x2009;6. After 14 days of treatment, serum biochemical indicators, renal function indicators, bladder and renal histopathology, and urine bacterial counts in rats were determined. Additionally, the effects of MZD on ESBLs E. coli biofilm formation and related gene expression were analyzed.<br><br>RESULTS: MZD significantly decreased the count of white blood cells (from 13.12 to 9.13), the proportion of neutrophils (from 43.53 to 23.18), C-reactive protein (from 13.21 to 9.71), serum creatinine (from 35.78 to 30.15), and urea nitrogen (from 12.56 to 10.15), relieved the inflammation and fibrosis of bladder and kidney tissues, and reduced the number of bacteria in urine (from 2174 to 559). In addition, MZD inhibited the formation of ESBLs E. coli biofilms (2.04-fold) and decreased the gene expressions of luxS, pfS and ompA (1.41-1.62-fold).<br><br>DISCUSSION AND CONCLUSION: MZD treated ESBLs E. coli-induced UTI inhibited biofilm formation, providing a theoretical basis for the clinical application of MZD. Further study on the clinical effect of MZD may provide a novel therapy option for UTI.}, }
@article {pmid37096387, year = {2023}, author = {Balkrishna, A and Kharayat, B and Rastogi, S and Kabdwal, M and Haldar, S and Varshney, A}, title = {Withania somnifera Seed Oil Exhibits Anti-biofilm Properties Against Drug-resistant Candida auris Clinical Isolate through Modulation in Cell Permeability.}, journal = {Journal of applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jambio/lxad087}, pmid = {37096387}, issn = {1365-2672}, abstract = {AIM: Candida auris, fast evolving drug-resistant fungus, poses an imminent global health threat. Alternative drug-resistance non-evoking treatment options are necessary. This study explored the antifungal and anti-biofilm efficacies of Withania somnifera seed oil extracted using super critical CO2 (WSSO) against clinically-isolated Fluconazole-resistant C. auris and its putative mode-of-action.<br><br>METHODS AND RESULTS: Effects of WSSO on C. auris was tested by broth microdilution method, with observed IC50 at 5.96&#xa0;mg ml-1. Time-kill assay revealed that WSSO is fungistatic. Mechanistically, ergosterol binding and sorbitol protection assays showed that C. auris cell membrane and cell wall are the targets for WSSO. Lactophenol: Cotton-Blue: Trypan-Blue staining confirmed loss of intracellular contents by WSSO treatment. C. auris biofilm formation was disrupted by WSSO (BIC50: 8.52&#xa0;mg ml-1). Additionally, WSSO exhibited dose and time dependent mature biofilm eradication property with 50% efficacies at 23.27, 19.28, 18.18 and 7.22&#xa0;mg ml-1 over 24, 48, 72 and 96&#xa0;h, respectively. Biofilm eradication by WSSO was further substantiated through Scanning-Electron-Microscopy (SEM). Standard-of-Care Amphotericin B, at its break-point concentration, (2&#xa0;&#xb5;g ml-1) was found to be inefficient as an anti-biofilm agent.<br><br>CONCLUSIONS: WSSO is a potent antifungal agent effective against planktonic C. auris and its biofilm.}, }
@article {pmid37096222, year = {2023}, author = {Chiou, LL and Panariello, BHD and Hamada, Y and Gregory, RL and Blanchard, S and Duarte, S}, title = {Comparison of In Vitro Biofilm Formation on Titanium and Zirconia Implants.}, journal = {BioMed research international}, volume = {2023}, number = {}, pages = {8728499}, pmid = {37096222}, issn = {2314-6141}, abstract = {BACKGROUND: Peri-implant diseases are emerging issues in contemporary implant dentistry. As biofilms play a critical role in peri-implant diseases, the characteristic of resisting bacterial adhesion would be ideal for dental implants. The aims of the study were to compare titanium (Ti) and zirconia (Zr) implants regarding the amount of biofilm formation at different time frames and assess the distribution of biofilm on different aspects of dental implants.<br><br>METHODS: Biofilm was developed on Ti and Zr dental implants with a peri-implant-related multispecies model with Streptococcus oralis, Actinomyces naeslundii, Veillonella dispar, and Porphyromonas gingivalis, for 3 and 14 days. Quantitative assessment was performed with the measurement of total bacterial viability (colony forming units, CFU/mg). Scanning electron microscopy (SEM) was used to evaluate biofilm formation on different aspects of the implants.<br><br>RESULTS: Three-day-old biofilm on Ti implants was significantly higher than that on Zr implants (p < 0.001). The Ti and Zr groups were not significantly different for 14-day-old biofilm. SEM images demonstrated that 3-day-old biofilm on Zr implants was sparse while biofilm growth was more pronounced for 3-day-old biofilm on Ti implants and 14-day-old biofilm groups. It appeared that less biofilm formed on the valley compared to the thread top for 3-day-old biofilm on Zr implants. Differences between the valley and the thread top became indistinguishable with the development of mature biofilm.<br><br>CONCLUSION: While early formed biofilms show greater accumulation on Ti implants compared to Zr implants, older biofilms between the two groups are comparable. The distribution of biofilms was not uniform on different areas of implant threads during early biofilm development.}, }
@article {pmid37094684, year = {2023}, author = {Zhao, Q and Liu, Y and Liao, C and Yan, X and Tian, L and Li, T and Li, N and Wang, X}, title = {Reduction of S[0] deposited on electroactive biofilm under an oxidative potential.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {163698}, doi = {10.1016/j.scitotenv.2023.163698}, pmid = {37094684}, issn = {1879-1026}, abstract = {The inevitable deposition of S[0] on the electroactive biofilm (EAB) via anodic sulfide oxidation affects the stability of bioelectrochemical systems (BESs) when an accidental discharge of sulfide occurred, leading to the inhibition of electroacitivity, because the potential of anode (e.g., 0 V versus Ag/AgCl) is ~500 mV more positive than the redox potential of S[2-]/S[0]. Here we found that S[0] deposited on the EAB can be spontaneously reduced under this oxidative potential independent of microbial community variation, leading to a self-recovery of electroactivity (> 100 % in current density) with biofilm thickening (~210 μm). Transcriptomics of pure culture indicated that Geobacter highly expressed genes involving in S[0] metabolism, which had an additional benefit to improve the viability (25 % - 36 %) of bacterial cells in biofilm distant from the anode and the cellular metabolic activity via electron shuttle pair of S[0]/S[2-](Sx[2-]). Our findings highlighted the importance of spatially heterogeneous metabolism to its stability when EABs encountered with the problem of S[0] deposition, and that in turn improved the electroactivity of EABs.}, }
@article {pmid37094608, year = {2023}, author = {Ravazzi, R and Neves, JG and Santamaria, MP and Rosa, LP and Rosa, FCS and Santamaria-Jr, M}, title = {Porphyrin-associated fluorescence spectroscopy (Photogen®) for the optical diagnosis of dental biofilm in orthodontic treatment: an observational clinical trial.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103580}, doi = {10.1016/j.pdpdt.2023.103580}, pmid = {37094608}, issn = {1873-1597}, abstract = {OBJECTIVE: This study assessed the presence of dental biofilm with fluorescence spectroscopy associated with porphyrin (Photogen®) in users of orthodontic appliances.<br><br>METHODS: This cross-sectional observational clinical trial included 21 patients with metallic orthodontic fixed appliances. The presence of biofilm was evaluated by fluorescence spectroscopy (Evince-MM&#xd3;ptics. S&#xe3;o Carlos-SP, Brazil) with a porphyrin photo-evidence device (Photogen&#xae;). Digital images of the buccal surface of the upper anterior teeth (central and lateral incisors and canines) without and with porphyrin were analyzed using the histogram R (red) function in ImageJ software. The results were analyzed using the maximum and mode values of the red pixels from the histograms. The statistical analysis considered the significance level of 5%.<br><br>RESULTS: The maximum values and modes of the red pixels were significantly higher in biofilms analyzed by porphyrin-associated optical spectroscopy compared to optical spectroscopy alone.<br><br>CONCLUSIONS: Porphyrin-associated fluorescence spectroscopy was able to detect dental biofilm in the oral environment of patients with orthodontic treatment. This method better evidenced the presence of biofilm on the buccal surfaces of the upper teeth compared to that observed with fluorescence spectroscopy without porphyrin.}, }
@article {pmid37094480, year = {2023}, author = {Vashistha, A and Sharma, N and Nanaji, Y and Kumar, D and Singh, G and Barnwal, RP and Yadav, AK}, title = {Quorum sensing inhibitors as Therapeutics: Bacterial biofilm inhibition.}, journal = {Bioorganic chemistry}, volume = {136}, number = {}, pages = {106551}, doi = {10.1016/j.bioorg.2023.106551}, pmid = {37094480}, issn = {1090-2120}, abstract = {The overuse and inappropriate use of antibiotics to treat bacterial infections has led to the development of multiple drug resistant strains. Biofilm is a complex microorganism aggregation defined by the presence of a dynamic, sticky, and protective extracellular matrix made of polysaccharides, proteins, and nucleic acids. The infectious diseases are caused by bacteria that flourish within quorum sensing (QS) mediated biofilms. Efforts to disrupt biofilms have enabled the identification of bioactive molecules produced by prokaryotes and eukaryotes. The QS system is quenched predominantly by these molecules. The phenomenon is also termed as quorum sensing (QS). Both synthetic and natural substances have been discovered to be useful in QS. This review describes natural and synthetic quorum sensing inhibitors (QSIs) with the potential to treat bacterial infections. It includes the discussion on quorum sensing, mechanism of quorum sensing, effect of substituents on the activity. These discoveries could result in effective therapies using far lower dosages of medications, particularly antibiotics, are currently needed.}, }
@article {pmid37093361, year = {2023}, author = {Eshtiaghi, S and Nazari, R and Fasihi-Ramandi, M}, title = {Molecular Docking, Anti-Biofilm &amp; Antibacterial Activities and Therapeutic Index of mCM11 Peptide on Acinetobacter baumannii Strains.}, journal = {Current microbiology}, volume = {80}, number = {6}, pages = {191}, pmid = {37093361}, issn = {1432-0991}, abstract = {Despite the huge efforts of microbiologists, infectious diseases have yet remained one of the leading causes of death in humans, further highlighting the research priority for controlling opportunistic pathogens. Many researchers have used antibacterial peptides to solve the problem of antibiotic resistance. This research is thus conducted to investigate the antibacterial and anti-biofilm activity of a novel modified cecropin-melittin 11-peptide with improved therapeutic properties and lower side effects. After synthesis and purification of mCM11 (NH2-WRLFRRILRVL-NH2) by solid-phase synthesis and HPLC methods, respectively, the antibacterial and biofilm inhibitory activities were explored in vitro. TMHMM was used to confirm the reaction of mCM11 on the plasma membrane of the prokaryotic cells. The interaction between mCM11 on Acinetobacter baumannii strains was investigated by molecular docking using ClusPro2.0. Hemolysis and therapeutic indexes were also calculated to quantify the relative safety and adverse effects of mCM11. According to the results, mCM11 has a high inhibitory and lethal effect on A. baumannii strains due to its cationic properties and new specific sequence. Molecular docking revealed the release of a significant amount of energy when mCM11 binds to the surface of A. baumannii in an appropriate site. The findings indicated that mCM11 IC50 (4 μg/mL) lysed 2.78% of RBCs; moreover, 8 strains of Acinetobacter baumannii showed a favorable therapeutic index. The mCM11 exhibits strong antibacterial and antibiofilm activities against A. baumannii strains, suggesting its potential therapeutic role in infections caused by these strains. Similar to its impact on A. baumannii, mCM11 could be a suitable alternative to antibiotics in combat against antibiotic-resistant bacteria in the in vivo experiments.}, }
@article {pmid37091817, year = {2023}, author = {Abu-Sini, M and Al-Kafaween, MA and Al-Groom, RM and Hilmi, ABM}, title = {Comparative in vitro activity of various antibiotic against planktonic and biofilm and the gene expression profile in Pseudomonas aeruginosa.}, journal = {AIMS microbiology}, volume = {9}, number = {2}, pages = {313-331}, pmid = {37091817}, issn = {2471-1888}, abstract = {P. aeruginosa is an opportunistic pathogen that is commonly found in nosocomial infections. The purpose of this study was to investigate the effects of seven antibiotics on P. aeruginosa planktonic growth, biofilm formation, and the expression of virulence factors. These antibiotics included Ciprofloxacin (CP), Amikacin (AMK), Vancomycin (VAN), Tetracycline (TET), Gentamicin (GEN), Erythromycin (Ery), and Clindamycin (CLI). Antibiotic susceptibility testing, Minimum Bactericidal Concentration (MBC), Minimum Inhibitory Concentration (MIC), growth curve, time-kill curve, biofilm inhibition and reduction assay, and RT-qPCR were used to assess the effects of these antibiotics on P. aeruginosa planktonic and biofilm. The clear zones of inhibition against P. aeruginosa for the CP, AMK, VAN, TET, GEN, Ery, and CLI were 26 mm, 20 mm, 21 mm, 22 mm, 20 mm, 25 mm and 23 mm, respectively. The MIC values for CP, AMK, VAN, TET, GEN, Ery and CLI against P. aeruginosa ranged from 0.25 to 1 µg/mL while the MBC values ranged from 1 and 0.5 to 2 µg/mL respectively. The growth, total viable counts (TVCs), bacterial adhesion and biofilm formation of P. aeruginosa were reduced after exposure to all the tested antibiotics in a dose-dependent manner. The RT-qPCR analysis showed that all the tested antibiotics share a similar overall pattern of gene expression, with a trend toward reduced expression of the virulence genes of interest (lasR, lasI, fleN, fleQ and fleR, oprB and oprC) in P. aeruginosa. The results indicate that all of the tested antibiotics possess antimicrobial and anti-biofilm activities, and that they may be multiple inhibitors and moderators of P. aeruginosa virulence via a variety of molecular targets. This deduction requires to be investigated in vivo.}, }
@article {pmid37091291, year = {2023}, author = {Velez, KEC and Leighton, RE and Decho, AW and Pinckney, JL and Norman, RS}, title = {Modeling pH and Temperature Effects as Climatic Hazards in Vibrio Vulnificus and Vibrio Parahaemolyticus Planktonic Growth and Biofilm Formation.}, journal = {GeoHealth}, volume = {7}, number = {4}, pages = {e2022GH000769}, pmid = {37091291}, issn = {2471-1403}, abstract = {Climate-induced stressors, such as changes in temperature, salinity, and pH, contribute to the emergence of infectious diseases. These changes alter geographical constraint, resulting in increased Vibrio spread, exposure, and infection rates, thus facilitating greater Vibrio-human interactions. Multiple efforts have been developed to predict Vibrio exposure and raise awareness of health risks, but most models only use temperature and salinity as prediction factors. This study aimed to better understand the potential effects of temperature and pH on V. vulnificus and V. parahaemolyticus planktonic and biofilm growth. Vibrio strains were grown in triplicate at 25°, 30°, and 37°C in 96 well plates containing Modified Seawater Yeast Extract modified with CaCl2 at pH's ranging from 5 to 9.6. AMiGA software was used to model growth curves using Gaussian process regression. The effects of temperature and pH were evaluated using randomized complete block analysis of variance, and the growth rates of V. parahaemolyticus and V. vulnificus were modeled using the interpolation fit on the MatLab Curve Fitting Toolbox. Different optimal conditions involving temperature and pH were observed for planktonic and biofilm Vibrio growth within- and between-species. This study showed that temperature and pH factors significantly affect Vibrio planktonic growth rates and V. parahaemolyticus biofilm formation. Therefore, pH effects must be added to the Vibrio growth modeling efforts to better predict Vibrio risk in estuarine and coastal zones that can potentially experience the cooccurrence of Vibrio and harmful algal bloom outbreak events.}, }
@article {pmid37090160, year = {2023}, author = {Qi, W and Skov, PV and de Jesus Gregersen, KJ and Pedersen, LF}, title = {A novel method to estimate biofilm activity based on enzymatic oxygen release from hydrogen peroxide decomposition.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100121}, pmid = {37090160}, issn = {2590-2075}, abstract = {Biofilm is central for biological water treatment processes in recirculating aquaculture systems (RAS). A lack of suitable methods for quantifying biofilm activity, however, makes it difficult to assess and compare the microbial status of biofilm. This type of information of the biofilm will be useful to assess the colonization status of nitrifying biocarriers or to evaluate the effect of disinfectants on the biofilm activity. Here we introduce a novel assay for rapid assessment of microbial activities in the biofilm attached on bioelements from a RAS biofilter. The assay consisted of an intermittent respirometer platform where biofilter elements were exposed to 10 mg/L hydrogen peroxide (H2O2) for 1 h, following concurrent measurements of oxygen release from the decomposition of H2O2 caused by biofilm-associated enzymes. A different number of colonized, mature bioelements from a moving bed biofilter in a freshwater RAS were tested with repeated H2O2 exposure, and compared against their autoclaved forms. A substantial increase in dissolved oxygen (DO) concentration (0.92-2.31 mg O2/L) occurred with mature bioelements during 1 h of H2O2 exposure, compared to small amounts of DO release (≤0.27 mg O2/L) with autoclaved bioelements. This substantiates that H2O2 decomposition by biofilm is mainly governed by microbial enzymatic activities. A monomolecular model fitted well with the observed oxygen release profiles of tested mature bioelements after H2O2 exposure (R[2] > 0.98). The kinetic rate constant of net oxygen release (k or , h[-1]) was proportional (R[2] for linear fit = 0.99) to the number of mature bioelements tested. Repeated exposure of H2O2 to the same bioelements did not change k or , which indicates that 10 mg/L H2O2 with an exposure time of 1 h does not suppress enzymatic activity in biofilm. Our study provides a new rapid method that allows simple quantification of microbial activity in biofilm samples from aquaculture systems, which could potentially be also applied to study biofilm from wastewater treatment plants and other industries.}, }
@article {pmid37089575, year = {2023}, author = {Guo, M and Yang, K and Zhou, Z and Chen, Y and Zhou, Z and Chen, P and Huang, R and Wang, X}, title = {Inhibitory effects of Stevioside on Streptococcus mutans and Candida albicans dual-species biofilm.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1128668}, pmid = {37089575}, issn = {1664-302X}, abstract = {INTRODUCTION: Streptococcus mutans is the most prevalent biofilm-forming pathogen in dental caries, while Candida albicans is often detected in the presence of S. mutans.<br><br>METHODS: We aimed to evaluate the anti-caries effect of stevioside in medium trypticase soy broth (TSB) with or without sucrose supplementation compared with the same sweetness sucrose and xylitol in a dual-species model of S. mutans and C. albicans, based on planktonic growth, crystal violet assay, acid production, biofilm structural imaging, confocal laser scanning microscopy, and RNA sequencing.<br><br>RESULTS: Our results showed that compared with sucrose, stevioside significantly inhibited planktonic growth and acid production, changed the structure of the mixed biofilm, and reduced the viability of biofilm and the production of extracellular polysaccharides in dual-species biofilm. Through RNA-seq, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway impact analysis showed that stevioside decreased sucrose metabolism and increased galactose and intracellular polysaccharide metabolism in S. mutans, and decreased genes related to GPI-modified proteins and secreted aspartyl proteinase (SAP) family in C. albicans. In contrast to xylitol, stevioside also inhibited the transformation of fungal morphology of C. albicans, which did not form mycelia and thus had reduced pathogenicity. Stevioside revealed a superior suppression of dual-species biofilm formation compared to sucrose and a similar anti-caries effect with xylitol. However, sucrose supplementation diminished the suppression of stevioside on S. mutans and C. albicans.<br><br>CONCLUSIONS: Our study is the first to confirm that stevioside has anticariogenic effects on S. mutans and C. albicans in a dual-species biofilm. As a substitute for sucrose, it may help reduce the risk of developing dental caries.}, }
@article {pmid37089551, year = {2023}, author = {Wu, T and Zhong, L and Pang, JW and Ren, NQ and Ding, J and Yang, SS}, title = {Effect of Fe[3+] on the nutrient removal performance and microbial community in a biofilm system.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1140404}, pmid = {37089551}, issn = {1664-302X}, abstract = {In this study, the influence of Fe[3+] on N removal, microbial assembly, and species interactions in a biofilm system was determined. The results showed that maximum efficiencies of ammonia nitrogen (NH4 [+]-N), total nitrogen (TN), phosphorus (P), and chemical oxygen demand (COD) removal were achieved using 10 mg/L Fe[3+], reaching values of 100, 78.85, 100, and 95.8%, respectively, whereas at concentrations of 15 and 30 mg/L Fe[3+] suppressed the removal of NH4 [+]-N, TN, and COD. In terms of absolute abundance, the expression of bacterial amoA, narG, nirK, and napA was maximal in the presence of 10 mg/L Fe[3+] (9.18 × 10[5], 8.58 × 10[8], 1.09 × 10[8], and 1.07 × 10[9] copies/g dry weight, respectively). Irrespective of Fe[3+] concentrations, the P removal efficiency remained at almost 100%. Candidatus_Competibacter (10.26-23.32%) was identified as the most abundant bacterial genus within the system. Determinism (50%) and stochasticity (50%) contributed equally to microbial community assembly. Co-occurrence network analysis revealed that in the presence of Fe[3+], 60.94% of OTUs in the biofilm system exhibited positive interactions, whereas 39.06% exhibited negative interactions. Within the OTU-based co-occurrence network, fourteen species were identified as key microbes. The stability of the system was found to be predominantly shaped by microbial cooperation, complemented by competition for resources or niche incompatibility. The results of this study suggested that during chemical P removal in wastewater treatment plants using biofilm methods, the concentration of supplemental Fe[3+] should be maintained at 10 mg/L, which would not only contribute to P elimination, but also enhance N and COD removal.}, }
@article {pmid37089543, year = {2023}, author = {Clarke, OE and Pelling, H and Bennett, V and Matsumoto, T and Gregory, GE and Nzakizwanayo, J and Slate, AJ and Preston, A and Laabei, M and Bock, LJ and Wand, ME and Ikebukuro, K and Gebhard, S and Sutton, JM and Jones, BV}, title = {Lipopolysaccharide structure modulates cationic biocide susceptibility and crystalline biofilm formation in Proteus mirabilis.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1150625}, pmid = {37089543}, issn = {1664-302X}, abstract = {Chlorhexidine (CHD) is a cationic biocide used ubiquitously in healthcare settings. Proteus mirabilis, an important pathogen of the catheterized urinary tract, and isolates of this species are often described as "resistant" to CHD-containing products used for catheter infection control. To identify the mechanisms underlying reduced CHD susceptibility in P. mirabilis, we subjected the CHD tolerant clinical isolate RS47 to random transposon mutagenesis and screened for mutants with reduced CHD minimum inhibitory concentrations (MICs). One mutant recovered from these screens (designated RS47-2) exhibited ~ 8-fold reduction in CHD MIC. Complete genome sequencing of RS47-2 showed a single mini-Tn5 insert in the waaC gene involved in lipopolysaccharide (LPS) inner core biosynthesis. Phenotypic screening of RS47-2 revealed a significant increase in cell surface hydrophobicity and serum susceptibility compared to the wildtype, and confirmed defects in LPS production congruent with waaC inactivation. Disruption of waaC was also associated with increased susceptibility to a range of other cationic biocides but did not affect susceptibility to antibiotics tested. Complementation studies showed that repression of smvA efflux activity in RS47-2 further increased susceptibility to CHD and other cationic biocides, reducing CHD MICs to values comparable with the most CHD susceptible isolates characterized. The formation of crystalline biofilms and blockage of urethral catheters was also significantly attenuated in RS47-2. Taken together, these data show that aspects of LPS structure and upregulation of the smvA efflux system function in synergy to modulate susceptibility to CHD and other cationic biocides, and that LPS structure is also an important factor in P. mirabilis crystalline biofilm formation.}, }
@article {pmid37088696, year = {2023}, author = {Ryder, M and deLancey-Pulcini, E and Parker, AE and James, GA}, title = {Bacterial transfer and biofilm formation in needleless connectors in a clinically simulated in vitro catheter model.}, journal = {Infection control and hospital epidemiology}, volume = {}, number = {}, pages = {1-9}, doi = {10.1017/ice.2023.60}, pmid = {37088696}, issn = {1559-6834}, abstract = {OBJECTIVE: Although needleless connectors (NCs) are widely used in clinical practice, they carry significant risk of bloodstream infection (BSI). In this study, we quantified differences in bacterial transfer and biofilm formation between various NCs.<br><br>DESIGN: Prospective, clinically simulated in vitro experimental study.<br><br>METHODS: We tested 20 NCs in a 5-day clinical simulation of Staphylococcus aureus inoculations onto NC septum surfaces, which were then flushed with saline and cultured for bacterial transfer. Biofilm formation was measured through destructive sampling of the connector-catheter system. Moreover, 8 NC design factors were evaluated for their influence on bacterial transfer and biofilm formation. This study was designed without a disinfection protocol to ascertain the intrinsic risk of each NC.<br><br>RESULTS: Clave Neutron and MicroClave had the lowest overall mean log density of bacteria in the flush compared to other NCs (P < .05), except there were no statistically significant differences between Clave Neutron, Microclave, SafeTouch, and SafeAccess (P &#x2265; .05). The amount of biofilm in the NC was positively associated with bacteria in the flush (P < .0005). Among 8 design factors, flow path was most important, with the internal cannula associated with a statistically significant 1 log reduction (LR) in bacteria in the flush (R[2] = 49%) and 0.5-2 LR in the connector (R[2] = 34%). All factors together best explained bacteria in the flush (R[2] = 65%) and biofilm in the connector (R[2] = 48%).<br><br>CONCLUSIONS: Bacterial transfer and biofilm formation in the connector-catheter system varied statistically significantly between the 20 NCs, suggesting that NC choice can lower the risk of developing catheter-related BSIs.}, }
@article {pmid37088385, year = {2023}, author = {Qiongjie, W and Yangyang, Z and Huijuan, C and Sulin, C and Yulai, W}, title = {Effects of humic acids on the adsorption of Pb(II) ions onto biofilm-developed microplastics in aqueous ecosystems.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {163466}, doi = {10.1016/j.scitotenv.2023.163466}, pmid = {37088385}, issn = {1879-1026}, abstract = {Microplastics (MPs), as emerging contaminants can behave as carriers for heavy metals in the water environments. Although the adsorption performance of heavy metals on MPs has been widely investigated, the effects of humic acids (HA) on the adsorption have seldom been explored. The authors were compared the Pb(II) adsorption onto biofilm-developed polyvinyl chloride (Bio-PVC) MPs with Pb(II) adsorption onto virgin PVC MPs (V-PVC), and explored the relationship between surface characteristics and the adsorption properties in the coexistence of HA. Our results showed that due to a larger specific surface area and more oxygen containing groups, Bio-PVC had a larger adsorption capability with a value of 3.57 mg/g than original ones (1.85 mg/g) due to its huge specific surface area and more oxygen containing groups. Microbial community analysis showed that the predominate bacteria in biofilms as Proteobacteria, Acidobacteria, Cyanobacteria, Firmicutes, and Bacteroidetes. Notably, the Pb(II) adsorption onto the V-PVC surfaces was increased, but the adsorption capacities of Pb(II) on Bio-PVC were suppressed with increasing HA. With the co-existence of HA, the increasing complexation and electrostatic attraction had attributed to the increased Pb(II) adsorption ability on V-PVC. Except for its competitive ability, HA has a shield effect which decreases the sorption sites on Bio-PVC. Overall, our findings provide a better understanding of the HA effect on the adsorption mechanism of heavy metals onto MPs in aquatic ecosystems.}, }
@article {pmid37087512, year = {2023}, author = {Feng, W and Yang, J and Ma, Y and Zhang, L and Yin, R and Qiao, Z and Ji, Y and Zhou, Y}, title = {Relationships between Secreted Aspartyl Proteinase 2 and General Control Nonderepressible 4 gene in the Candida albicans resistant to itraconazole under planktonic and biofilm conditions.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {37087512}, issn = {1678-4405}, abstract = {This study aimed to explore the roles of SAP2 and GCN4 in itraconazole (ITR) resistance of C. albicans under different conditions, and their correlations. A total of 20 clinical strains of C. albicans, including 10 ITR resistant strains and 10 sensitive strains, were used. Then, SAP2 sequencing and GCN4 sequencing were performed, and the biofilm formation ability of different C. albicans strains was determined. Finally, real-time quantitative PCR was used to measure the expression of SAP2 and GCN4 in C. albicans under planktonic and biofilm conditions, as well as their correlation was also analyzed. No missense mutations and three synonymous mutation sites, including T276A, G543A, and A675C, were found in SAP2 sequencing. GCN4 sequencing showed one missense mutation site (A106T (T36S)) and six synonymous mutation sites (A147C, C426T, T513C, T576A, G624A and C732T). The biofilm formation ability of drug-resistant C. albicans strains was significantly higher than that of sensitive strains (P < 0.05). Additionally, SAP2 and GCN4 were up-regulated in the ITR-resistant strains, and were both significantly higher in C. albicans under biofilm condition. The mRNA expression levels of SAP2 and GCN4 had significantly positive correlation. The higher expression levels of SAP2 and GCN4 were observed in the ITR-resistant strains of C. albicans under planktonic and biofilm conditions, as well as there was a positive correlation between SAP2 and GCN4 mRNA expression.}, }
@article {pmid37087265, year = {2023}, author = {Wang, Y and Wu, Y and Niu, H and Liu, Y and Ma, Y and Wang, X and Li, Z and Dong, Q}, title = {Different cellular fatty acid pattern and gene expression of planktonic and biofilm state Listeria monocytogenes under nutritional stress.}, journal = {Food research international (Ottawa, Ont.)}, volume = {167}, number = {}, pages = {112698}, doi = {10.1016/j.foodres.2023.112698}, pmid = {37087265}, issn = {1873-7145}, abstract = {Listeria monocytogenes is a Gram-positive bacterium frequently involved in food-borne disease outbreaks and is widely distributed in the food-processing environment. This work aims to depict the impact of nutrition deficiency on the survival strategy of L. monocytogenes both in planktonic and biofilm states. In the present study, cell characteristics (autoaggression, hydrophobicity and motility), membrane fatty acid composition of MRL300083 (Lm83) in the forms of planktonic and biofilm-associated cells cultured in TSB-YE and 10-fold dilutions of TSB-YE (DTSB-YE) were investigated. Additionally, the relative expression of related genes were also determined by RT-qPCR. It was observed that cell growth in different bacterial life modes under nutritional stress rendered the cells a distinct phenotype. The higher autoaggression (AAG) and motility of the planktonic cells in DTSB-YE is associated with better biofilm formation. An increased proportion of unsaturated fatty acid/saturated fatty acid (USFA/SFA) indicates more fluidic biophysical properties for cell membranes of L. monocytogenes in planktonic and biofilm cells in DTSB-YE. Biofilm cells produced a higher percentage of USFA and straight fatty acids than the corresponding planktonic cells. An appropriate degree of membrane fluidity is crucial for survival, and alteration of membrane lipids is an essential adaptive response. The adaptation of bacteria to stress is a multifactorial cellular process, the expression of flagella-related genes fliG, fliP, flgE and the two-component chemotactic system cheA/Y genes of planktonic cells in DTSB-YE significantly increased compared to that in TSB-YE (p < 0.05). This study provides new information on the role of the physiological adaptation and gene expression of L. monocytogenes for planktonic and biofilm growth under nutritional stress.}, }
@article {pmid37086710, year = {2023}, author = {Arslan, E and Coşkun, MK and Çobanoğlu, &#x15e; and Aslan, MH and Yazıcı, A}, title = {Effects of four antibiotics on Pseudomonas aeruginosa motility, biofilm formation, and biofilm-specific antibiotic resistance genes expression.}, journal = {Diagnostic microbiology and infectious disease}, volume = {106}, number = {3}, pages = {115931}, doi = {10.1016/j.diagmicrobio.2023.115931}, pmid = {37086710}, issn = {1879-0070}, abstract = {The aim of this study was to determine the effects of 4 antibiotics (tobramycin, fosfomycin, ciprofloxacin, and piperacillin/tazobactam) against Pseudomonas aeruginosa motility, biofilm formation, and biofilm resistance gene expression changes using different methods including microscopy, microdilution, crystal violet staining, and qRT-PCR. Although the antibiotics reduced swarming motility, they inhibited biofilm formation to a greater extent than the minimum inhibitory concentration (MIC) value. The qRT-PCR results showed that the antibiotics, other than fosfomycin, decreased the expression levels of the selected biofilm resistance genes (ndvB, tssC1, PA5033 and PA2070) in the biofilm structure compared to planktonic cells. Furthermore, it was found that there was an increase in the expression levels of biofilm resistance genes in the antibiotic application groups compared to the biofilm structure that was not treated with antibiotics. These results showed for the first time that the treatment of antibiotics at sub-MIC concentrations increases the expression levels of biofilm-specific resistance genes and contributes to resistance and motility.}, }
@article {pmid37086303, year = {2023}, author = {Marchi, AP and Farrel Côrtes, M and Vásconez Noguera, S and Rossi, F and Levin, AS and Figueiredo Costa, S and Perdigão Neto, LV}, title = {Chlorhexidine susceptibility and Eagle effect in planktonic cells and biofilm of nosocomial isolates.}, journal = {European journal of clinical microbiology &amp; infectious diseases : official publication of the European Society of Clinical Microbiology}, volume = {}, number = {}, pages = {}, pmid = {37086303}, issn = {1435-4373}, abstract = {The aim of this study is to evaluate the chlorhexidine gluconate (CHG) susceptibility in both planktonic cells and biofilm of 32 Gram-negative (Gn) and 6 Gram-positive (Gp) isolates by minimal inhibitory concentration (2-256 μg/mL for Gn and 2-32 μg/mL for Gp), minimal bactericidal concentration (4-256 μg/mL for Gn and 2-32 μg/mL for Gp) in planktonic cells, and minimal biofilm elimination concentration (128 ≥ 16,384 μg/mL in Gn and 32 ≥ 16,384 μg/mL in Gp) in biofilm environment. Our study showed that Gn isolates have higher minimal concentrations than Gp and bacteria in biofilms are more tolerant than planktonic ones. No correlation between MBC or MBEC and biofilm formation was statistically confirmed. The Eagle effect, previously described for antimicrobials and antifungals, was evidenced in this work for CHG, an antiseptic. Besides that, the phenomenon was described in 23/38 isolates (60.5%), raising minimal concentration up to ≥ 16,384 μg/mL. Our study showed that clinical isolates have a high ability to form biofilm allowing them to tolerate CHG concentrations as high as the ones used in clinical practice. Therefore, attention should be given to the occurrence of this phenomenon to avoid false susceptibility results.}, }
@article {pmid37085670, year = {2023}, author = {Tsarenko, SV and Zigangirova, NA and Soloveva, AV and Bondareva, NE and Koroleva, EA and Sheremet, AB and Kapotina, LN and Shevlyagina, NV and Andreevskaya, SG and Zhukhovitsky, VG and Filimonova, EV and Gintsburg, AL}, title = {A novel antivirulent compound fluorothiazinone inhibits Klebsiella pneumoniae biofilm in vitro and suppresses model pneumonia.}, journal = {The Journal of antibiotics}, volume = {}, number = {}, pages = {}, pmid = {37085670}, issn = {1881-1469}, abstract = {The problematic treatment of infections caused by multiple-resistant Klebsiella, especially in ICU, is the leading cause of prolonged hospitalization and high mortality rates. The use of antibiotics for the prevention of infections is considered unreasonable as it may contribute to the selection of resistant bacteria. In this regard, the development of drugs that will be effective in preventing infection during various invasive procedures is extremely necessary. We have shown that the developed innovative antibacterial compound fluorothiazinone (FT) that suppresses the formation of biofilms is effective in the prevention of a model pneumonia caused by a multi-resistant clinical K. pneumoniae isolate. Prophylactic use followed by treatment with FT in mice with acute pneumonia modulates the local innate immune response without suppressing protective properties in the early stages of infection, while contributing to a decrease in the bacterial load in the organs and preventing lethal pathological changes in the lungs at later stages of K. pneumoniae infection. Further development of such antivirulence drugs and their use will reduce morbidity and mortality in nosocomial infections, as well as reduce the number of antibiotics used.}, }
@article {pmid37085401, year = {2023}, author = {Lü, J and Ren, G and Hu, Q and Rensing, C and Zhou, S}, title = {Microbial biofilm-based hydrovoltaic technology.}, journal = {Trends in biotechnology}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.tibtech.2023.03.012}, pmid = {37085401}, issn = {1879-3096}, abstract = {Hydrovoltaic electricity generation (HEG) utilizes the latent environmental heat stored in water, and subsequently harvests the electrical energy. However, sustainable HEG has remained extremely challenging due either to complex fabrication and high cost, or to restricted environmental compatibility and renewability. Electroactive microorganisms are environmentally abundant and viable in performing directional electron transport to produce currents. These distinctive features have inspired microbial HEG systems that can convert environmental energy into hygroelectricity upon water circulation from raindrops, waves, and water moisture, and has recently succeeded as proof of concept for becoming a cutting-edge biotechnology. In this review, recent advances in microbial biofilm-based hydrovoltaic technology are highlighted to better understand a promising method of electricity generation from environmental energy with the aim of practical applications.}, }
@article {pmid37085193, year = {2023}, author = {Cai, JN and Kim, D}, title = {Biofilm ecology associated with dental caries: understanding of microbial interactions in oral communities leads to development of therapeutic strategies targeting cariogenic biofilms.}, journal = {Advances in applied microbiology}, volume = {122}, number = {}, pages = {27-75}, doi = {10.1016/bs.aambs.2023.02.001}, pmid = {37085193}, issn = {0065-2164}, abstract = {A biofilm is a sessile community characterized by cells attached to the surface and organized into a complex structural arrangement. Dental caries is a biofilm-dependent oral disease caused by infection with cariogenic pathogens, such as Streptococcus mutans, and associated with frequent exposure to a sugar-rich diet and poor oral hygiene. The virulence of cariogenic biofilms is often associated with the spatial organization of S. mutans enmeshed with exopolysaccharides on tooth surfaces. However, in the oral cavity, S. mutans does not act alone, and several other microbes contribute to cariogenic biofilm formation. Microbial communities in cariogenic biofilms are spatially organized into complex structural arrangements of various microbes and extracellular matrices. The balance of microbiota diversity with reduced diversity and a high proportion of acidogenic-aciduric microbiota within the biofilm is closely related to the disease state. Understanding the characteristics of polymicrobial biofilms and the association of microbial interactions within the biofilm (e.g., symbiosis, cooperation, and competition) in terms of their potential role in the pathogenesis of oral disease would help develop new strategies for interventions in virulent biofilm formation.}, }
@article {pmid37083842, year = {2023}, author = {Fernandes, M and González-Ballesteros, N and da Costa, A and Machado, R and Gomes, AC and Rodríguez-Argüelles, MC}, title = {Antimicrobial and anti-biofilm activity of silver nanoparticles biosynthesized with Cystoseira algae extracts.}, journal = {Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry}, volume = {}, number = {}, pages = {}, pmid = {37083842}, issn = {1432-1327}, abstract = {Antimicrobial resistance is an ever-growing global concern to public health with no clear or immediate solution. Silver nanoparticles (AgNPs) have long been proposed as efficient agents to fight the growing number of antibiotic-resistant strains. However, the synthesis of these particles is often linked to high costs and the use of toxic, hazardous chemicals, with environmental and health impact. In this study, we successfully produced AgNPs by green synthesis with the aid of the extract of two brown algae-Cystoseira baccata (CB) and Cystoseira tamariscifolia (CT)-and characterized their physico-chemical properties. The NPs produced in both cases (Ag@CB and Ag@CT) present similar sizes, with mean diameters of around 22 nm. The antioxidant activity of the extracts and the NPs was evaluated, with the extracts showing important antioxidant activity. The bacteriostatic and bactericidal properties of both Ag@CB and Ag@CT were tested and compared with gold NPs produced in the same algae extracts as previously reported. AgNPs demonstrated the strongest bacteriostatic and bactericidal properties, at concentrations as low as 2.16 µg/mL against Pseudomonas aeruginosa and Escherichia coli. Finally, the capacity of these samples to prevent the formation of biofilms characteristic of infections with a poorer outcome was assessed, obtaining similar results. This work points towards an alternative for the treatment of bacterial infections, even biofilm-inducing, with the possibility of minimizing the risk of drug resistance, albeit the necessary caution implied using metallic NPs.}, }
@article {pmid37082420, year = {2023}, author = {Marienborg, K and Ambur, OH and Økstad, OAL and Skaare, D}, title = {The alginate polymer OligoG alters susceptibility of biofilm-embedded non-typeable Haemophilus influenzae to ampicillin and ciprofloxacin.}, journal = {JAC-antimicrobial resistance}, volume = {5}, number = {2}, pages = {dlad046}, pmid = {37082420}, issn = {2632-1823}, abstract = {OBJECTIVES: Treatment of respiratory infections with non-typeable Haemophilus influenzae (NTHi) in COPD patients is complicated by biofilm formation, protecting the bacteria against the hosts' immune response and antibiotics. We investigated the antibiofilm and antibacterial effects of the alginate polymer OligoG, alone or combined with ampicillin or ciprofloxacin, on mature NTHi biofilms.<br><br>MATERIALS AND METHODS: Two unrelated COPD strains with PBP3-mediated &#x3b2;-lactam resistance, with additional TEM-1 &#x3b2;-lactamase (Hi-022) or quinolone resistance due to altered GyrA and ParC (Hi-072) were used. Antibiofilm and antibacterial effects were assessed macroscopically, by measurement of biofilm biomass (OD), and by viable cell counts, with determination of minimum biofilm inhibitory concentration (MBIC) and the novel parameter 'minimum concentration for 2&#x2005;log10&#x2005;drop in viable cells in biofilm' (MB2LDC). Drug interactions between OligoG and antibiotics were assessed by comparing expected and observed inhibitory effects (percent inhibition of no-treatment control) of combined treatment.<br><br>RESULTS: OligoG had dose-dependent biofilm disruptive abilities and a weak inhibitory effect on viable cells. Combination with OligoG (64&#x2005;g/L) significantly lowered MBIC for ampicillin (both strains) and MB2LDC for ciprofloxacin (Hi-022). For Hi-022, there was significant synergism between OligoG and both antibiotics. For Hi-072, interactions were subtle, but a tendency in direction of antagonism was significant at two concentrations of ciprofloxacin.<br><br>CONCLUSIONS: OligoG shows promise as a potential adjuvant to antibiotics in NTHi infections, but strain-specific factors appear to affect drug interactions and may lead to antagonism. More research is needed to clarify the mechanisms of action of OligoG and interactions with antibiotics.}, }
@article {pmid37082178, year = {2023}, author = {Pang, L and Lin, H and Yang, F and Deng, D}, title = {Editorial: Mechanisms of biofilm development and antibiofilm strategies.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1190611}, pmid = {37082178}, issn = {1664-302X}, }
@article {pmid37081770, year = {2023}, author = {Yang, X and Lan, W and Xie, J}, title = {Inhibitory effect of chlorogenic acid-grafted chitosan on seafood isolates Pseudomonas fluorescens and its biofilm.}, journal = {Letters in applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/lambio/ovad050}, pmid = {37081770}, issn = {1472-765X}, abstract = {This study aimed to examine the inhibition of chlorogenic acid-grafted chitosan (CS-g-CA) on Pseudomonas fluorescens (P. fluorescens) and its biofilm. The minimum inhibitory concentration (MIC) of CS-g-CA against P. fluorescens was 1.25 mg/mL. Alkaline phosphatase (AKP) leak assay and scanning electron microscopy (SEM) indicted that CS-g-CA causes structural damage to cell walls and membranes, resulting in the loss of function. In addition, CS-g-CA was able to disrupt the antioxidant system of P. fluorescens, interfere with energy metabolism, and interact with genomic DNA, affecting the normal physiological function of bacteria. It was also found that CS-g-CA inhibited the flagellar motility of P. fluorescens, which may be responsible for the inhibition of its biofilm formation. CS-g-CA at 2MIC was able to remove 71.64% of the mature biofilm and reduce the production of extracellular polysaccharides (EPS) by 60.72%. This was further confirmed by confocal laser scanning microscopy (CLSM), which showed a significant reduction in the amount of biofilm. In summary, CS-g-CA has strong antibacterial and anti-biofilm activities against P. fluorescens, and it can be applied as a potential seafood bacteriostatic agent.}, }
@article {pmid37081415, year = {2023}, author = {Shaaban, S and Genena, S and Elraggal, A and Hamad, GM and Meheissen, MA and Moussa, S}, title = {Antibacterial effectiveness of multi-strain probiotics supernatants intracanal medication on Enterococcus faecalis biofilm in a tooth model.}, journal = {BMC oral health}, volume = {23}, number = {1}, pages = {228}, pmid = {37081415}, issn = {1472-6831}, abstract = {BACKGROUND: To assess the antibacterial activity of multi-strain probiotics supernatants (MSP); Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus acidophilus as an intracanal medication on Enterococcus faecalis (E. faecalis) biofilm in a tooth model.<br><br>METHODS: Sixty extracted human single-rooted teeth with single canals were instrumented, sterilized, and inoculated with E. faecalis. After 21 days of incubation, four specimens were randomly selected to validate the biofilm formation by scanning electron microscope (SEM). The remaining specimens were randomly divided (n&#x2009;=&#x2009;14), according to the intracanal medication (ICM) received into: Ca(OH)2: calcium hydroxide paste (35% Ultra Cal XS Ca(OH)2), Probiotics supernatants: MSP in poloxamer gel vehicle Poloxamer: poloxamer gel vehicle and, Control: E. faecalis biofilm only. The tested groups were further subdivided into two equal subgroups (n&#x2009;=&#x2009;7) according to the incubation period (24&#xa0;h and 7 days). Shaved dentin chips were obtained and collected by H-files and paper points, respectively for bacterial culture. The antibacterial activity was assessed after each incubation period quantitatively and qualitatively using bacterial colony-forming units per milliliter (CFUs/ml) and SEM, respectively.<br><br>RESULTS: The lowest CFUs/ml was found in Ca (OH)2 with a significant difference compared to other groups after 24&#xa0;h. After 7 days, a similar outcome was found with a further significant reduction of CFUs/ml in all groups with no statistical difference between Ca(OH)2 and probiotics supernatants groups. Ca (OH)2 and Probiotics supernatants groups showed a significant (p&#x2009;<&#x2009;0.05) percentage of overall bacterial reduction (100.00&#x2009;&#xb1;&#x2009;0.00% and 70.30&#x2009;&#xb1;&#x2009;12.95%, respectively) compared to poloxamer and control groups (27.80&#x2009;&#xb1;&#x2009;14.45 and 28.29&#x2009;&#xb1;&#x2009;19.79). SEM images showed a bacteria-free state in the Ca(OH)2 group after 7 days while few bacteria were found in the probiotics supernatants group. An extensive invasion of bacteria was found in poloxamer and controls groups.<br><br>CONCLUSION: MSP has a potential antibacterial effect on E. faecalis growth closely similar to the routinely used Ca (OH)2.}, }
@article {pmid37080530, year = {2023}, author = {Bijle, MN and Abdalla, MM and Hung, IFN and Yiu, CKY}, title = {The effect of synbiotic-fluoride therapy on multi-species biofilm.}, journal = {Journal of dentistry}, volume = {}, number = {}, pages = {104523}, doi = {10.1016/j.jdent.2023.104523}, pmid = {37080530}, issn = {1879-176X}, abstract = {OBJECTIVES: The study objective was to examine the effect of synbiotic-fluoride (SF) therapy within a multi-species cariogenic biofilm model system comprising of S. mutans, S. sanguinis, and S. gordonii.<br><br>METHODS: The SF therapy was prepared using 2% L-arginine (Arg), 0.2% NaF and probiotic L. rhamnosus GG (LRG). The 8 treatment groups were: Group 1: No treatment, Group 2: 2% Arg, Group 3: 0.2% NaF, Group 4: LRG, Group 5: 2% Arg+0.2% NaF, Group 6: 2% Arg+LRG, Group 7: 0.2% NaF+LRG, and Group 8: SF therapy (2% Arg+0.2% NaF +LRG). Multi-species biofilm model over 96 h comprising Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii was utilized. The biofilms received cariogenic challenge and SF therapy 2&#x202f;&#xd7;&#x202f;/day. The extracellular matrix components were analyzed for carbohydrates, proteins, and extra-cellular DNA (eDNA). The live/dead cells were imaged and quantified using confocal microscopy. The viable/dead bacterial concentrations were estimated using propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR). The gene expressions for gtfB, sagP, arcA, argG, and argH were measured using real-time reverse transcriptase qPCR.<br><br>RESULTS: Carbohydrates and protein content with SF therapy were higher than non-LRG containing groups, while eDNA content was lower than other groups (p<0.05). Live bacterial proportions determined using confocal imaging with SF therapy were the lowest (p<0.05). The 2% Arg+LRG and SF therapy showed higher viable L. rhamnosus GG than 0.2% NaF+LRG (p<0.05). The dead S. mutans with SF therapy were higher than the other groups (p<0.05) with no difference from 2% Arg+0.2% NaF and 2% Arg+LRG (p>0.05). The SF therapy significantly downregulates gtfB and upregulates sagP, arcA, argG, argH gene expression (p<0.05).<br><br>CONCLUSION: Synbiotic-fluoride therapy effectuates multi-fold changes in the multi-species biofilm matrix and cellular components leading to superior ecological homeostasis than its individual contents, prebiotics (arginine), probiotic (L. rhamnosus GG), and fluorides (NaF).<br><br>CLINICAL SIGNIFICANCE: The ecological-based synbiotic-fluoride caries-preventive therapy aids in maintaining biofilm homeostasis to preempt/restore dysbiosis thereby sustaining dynamic-diverse health-associated microbial stability significant as a preventive regimen for high caries-risk patients.}, }
@article {pmid37080258, year = {2023}, author = {Huijboom, L and Tempelaars, M and Fan, M and Zhu, Y and Boeren, S and van der Linden, E and Abee, T}, title = {L-tyrosine modulates biofilm formation of Bacillus cereus ATCC 14579.}, journal = {Research in microbiology}, volume = {}, number = {}, pages = {104072}, doi = {10.1016/j.resmic.2023.104072}, pmid = {37080258}, issn = {1769-7123}, abstract = {Bacillus cereus is a food-borne pathogen capable of producing biofilms. Following analysis of biofilm formation by B. cereus ATCC 14579 transposon mutants in defined medium (DM), a deletion mutant of bc2939 (Δbc2939) was constructed that showed decreased crystal violet biofilm staining and biofilm cell counts. In addition, Δbc2939 also produced smaller colony biofilms with lower cell counts and loss of wrinkly morphology. The bc2939 gene encodes for Prephenate dehydrogenase, which converts Prephenate to 4-Hydroxy-phenylpyruvate (4-HPPA) in the L-tyrosine branch of the Shikimate pathway. While growth of the mutant and WT in DM was similar, addition of L-tyrosine was required to restore WT-like (colony) biofilm formation. Comparative proteomics showed reduced expression of Tyrosine-protein kinase/phosphatase regulators and extracellular polysaccharide cluster 1 (EPS1) proteins, aerobic electron transfer chain cytochrome aa3/d quinol oxidases, and iso-chorismate synthase involved in menaquinone synthesis in DM grown mutant biofilm cells, while multiple oxidative stress-related catalases and superoxide dismutases were upregulated. Performance in shaking cultures showed a 100-fold lower concentration of menaquinone-7 and reduction in cell counts of DM grown Δbc2939 indicating increased oxygen sensitivity. Combining all results, points to an important role of Tyrosine-modulated EPS1 production and menaquinone-dependent aerobic respiration in B. cereus ATCC 14579 (colony) biofilm formation.}, }
@article {pmid37080094, year = {2023}, author = {Cattò, C and Mu, A and Moreau, JW and Wang, N and Cappitelli, F and Strugnell, R}, title = {Biofilm colonization of stone materials from an Australian outdoor sculpture: Importance of geometry and exposure.}, journal = {Journal of environmental management}, volume = {339}, number = {}, pages = {117948}, doi = {10.1016/j.jenvman.2023.117948}, pmid = {37080094}, issn = {1095-8630}, abstract = {The safeguarding of Australian outdoor stone heritage is currently limited by a lack of information concerning mechanisms responsible for the degradation of the built heritage. In this study, the bacterial community colonizing the stone surface of an outdoor sculpture located at the Church of St. John the Evangelist in Melbourne was analysed, providing an overview of the patterns of microbial composition associated with stone in an anthropogenic context. Illumina MiSeq 16S rRNA gene sequencing together with confocal laser microscope investigations highlighted the bacterial community was composed of both phototrophic and chemotrophic microorganisms characteristic of stone and soil, and typical of arid, salty and urban environments. Cardinal exposure, position and surface geometry were the most important factors in determining the structure of the microbial community. The North-West exposed areas on the top of the sculpture with high light exposure gave back the highest number of sequences and were dominated by Cyanobacteria. The South and West facing in middle and lower parts of the sculpture received significantly lower levels of radiation and were dominated by Actinobacteria. Proteobacteria were observed as widespread on the sculpture. This pioneer research provided an in-depth investigation of the microbial community structure on a deteriorated artistic stone in the Australian continent and provides information for the identification of deterioration-associated microorganisms and/or bacteria beneficial for stone preservation.}, }
@article {pmid37079063, year = {2023}, author = {Wang, H and Ge, Q and Shao, X and Wei, Y and Zhang, X and Wang, H and Xu, F}, title = {Influences of flavonoids from Sedum aizoon L. on biofilm formation of Pseudomonas fragi.}, journal = {Applied microbiology and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {37079063}, issn = {1432-0614}, abstract = {Pseudomonas fragi (P. fragi) is one of the main categories of bacteria responsible for the spoilage of chilled meat. In the processing and preservation of chilled meat, it is easy to form biofilms on the meat, leading to the development of slime on the meat, which becomes a major quality defect. Flavonoids, as one of the critical components of secondary plant metabolites, are receiving increasing attention for their antibacterial activity. Flavonoids in Sedum aizoon L. (FSAL), relying on its prominent antibacterial activity, are of research importance in food preservation and other applications. This article aims to investigate the effect of FSAL on the biofilm formation of P. fragi, to better apply FSAL to the processing and preservation of meat products. The disruption of cellular structure and aggregation properties by FSAL was demonstrated by the observation of the cellular state within the biofilm. The amount of biofilm formation was determined by crystal violet staining, and the content of polysaccharides and proteins in the extracellular wrapped material was determined. It was shown that the experimental concentrations of FSAL (1.0 MIC) was able to inhibit biofilm formation and reduce the main components in the extracellular secretion. The swimming motility assay and the downregulation of flagellin-related genes confirmed that FSAL reduced cell motility and adhesion. The downregulation of cell division genes and the lowering of bacterial metabolic activity suggested that FSAL could hinder bacterial growth and reproduction within P. fragi biofilms. KEY POINTS: • FSAL inhibited the activity of Pseudomonas fragi in the dominant meat strain • The absence of EPS components affected the formation of P. fragi biofilms • P. fragi has reduced adhesion capacity due to impaired flagellin function.}, }
@article {pmid37079062, year = {2023}, author = {Elfaky, MA and Elbaramawi, SS and Eissa, AG and Ibrahim, TS and Khafagy, ES and Ali, MAM and Hegazy, WAH}, title = {Drug repositioning: doxazosin attenuates the virulence factors and biofilm formation in Gram-negative bacteria.}, journal = {Applied microbiology and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {37079062}, issn = {1432-0614}, abstract = {The resistance development is an increasing global health risk that needs innovative solutions. Repurposing drugs to serve as anti-virulence agents is suggested as an advantageous strategy to diminish bacterial resistance development. Bacterial virulence is controlled by quorum sensing (QS) system that orchestrates the expression of biofilm formation, motility, and virulence factors production as enzymes and virulent pigments. Interfering with QS could lead to bacterial virulence mitigation without affecting bacterial growth that does not result in bacterial resistance development. This study investigated the probable anti-virulence and anti-QS activities of α-adrenoreceptor blocker doxazosin against Proteus mirabilis and Pseudomonas aeruginosa. Besides in silico study, in vitro and in vivo investigations were conducted to assess the doxazosin anti-virulence actions. Doxazosin significantly diminished the biofilm formation and release of QS-controlled Chromobacterium violaceum pigment and virulence factors in P. aeruginosa and P. mirabilis, and downregulated the QS encoding genes in P. aeruginosa. Virtually, doxazosin interfered with QS proteins, and in vivo protected mice against P. mirabilis and P. aeruginosa. The role of the membranal sensors as QseC and PmrA was recognized in enhancing the Gram-negative virulence. Doxazosin downregulated the membranal sensors PmR and QseC encoding genes and could in silico interfere with them. In conclusion, this study preliminary documents the probable anti-QS and anti-virulence activities of doxazosin, which indicate its possible application as an alternative or in addition to antibiotics. However, extended toxicological and pharmacological investigations are essential to approve the feasible clinical application of doxazosin as novel efficient anti-virulence agent. KEY POINTS: • Anti-hypertensive doxazosin acquires anti-quorum sensing activities • Doxazosin diminishes the virulence of Proteus mirabilis and Pseudomonas aeruginosa • Doxazosin could dimmish the bacterial espionage.}, }
@article {pmid37078875, year = {2023}, author = {Palau, M and Muñoz, E and Gusta, MF and Larrosa, N and Gomis, X and Gilabert, J and Almirante, B and Puntes, V and Texidó, R and Gavaldà, J}, title = {In Vitro Antibacterial Activity of Silver Nanoparticles Conjugated with Amikacin and Combined with Hyperthermia against Drug-Resistant and Biofilm-Producing Strains.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0028023}, doi = {10.1128/spectrum.00280-23}, pmid = {37078875}, issn = {2165-0497}, abstract = {In view of the current increase and spread of antimicrobial resistance (AMR), there is an urgent need to find new strategies to combat it. This study had two aims. First, we synthesized highly monodispersed silver nanoparticles (AgNPs) of approximately 17 nm, and we functionalized them with mercaptopoly(ethylene glycol) carboxylic acid (mPEG-COOH) and amikacin (AK). Second, we evaluated the antibacterial activity of this treatment (AgNPs_mPEG_AK) alone and in combination with hyperthermia against planktonic and biofilm-growing strains. AgNPs, AgNPs_mPEG, and AgNPs_mPEG_AK were characterized using a suite of spectroscopy and microscopy methods. Susceptibility to these treatments and AK was determined after 24 h and over time against 12 clinical multidrug-resistant (MDR)/extensively drug-resistant (XDR) isolates of Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The efficacy of the treatments alone and in combination with hyperthermia (1, 2, and 3 pulses at 41°C to 42°C for 15 min) was tested against the same planktonic strains using quantitative culture and against one P. aeruginosa strain growing on silicone disks using confocal laser scanning microscopy. The susceptibility studies showed that AgNPs_mPEG_AK was 10-fold more effective than AK alone, and bactericidal efficacy after 4, 8, 24, or 48 h was observed against 100% of the tested strains. The combination of AgNPs_mPEG_AK and hyperthermia eradicated 75% of the planktonic strains and exhibited significant reductions in biofilm formation by P. aeruginosa in comparison with the other treatments tested, except for AgNPs_mPEG_AK without hyperthermia. In conclusion, the combination of AgNPs_mPEG_AK and hyperthermia may be a promising therapy against MDR/XDR and biofilm-producing strains. IMPORTANCE Antimicrobial resistance (AMR) is one of the greatest public health challenges, accounting for 1.27 million deaths worldwide in 2019. Biofilms, a complex microbial community, directly contribute to increased AMR. Therefore, new strategies are urgently required to combat infections caused by AMR and biofilm-producing strains. Silver nanoparticles (AgNPs) exhibit antimicrobial activity and can be functionalized with antibiotics. Although AgNPs are very promising, their effectiveness in complex biological environments still falls below the concentrations at which AgNPs are stable in terms of aggregation. Thus, improving the antibacterial effectiveness of AgNPs by functionalizing them with antibiotics may be a significant change to consolidate AgNPs as an alternative to antibiotics. It has been reported that hyperthermia has a large effect on the growth of planktonic and biofilm-producing strains. Therefore, we propose a new strategy based on AgNPs functionalized with amikacin and combined with hyperthermia (41°C to 42°C) to treat AMR and biofilm-related infections.}, }
@article {pmid37077927, year = {2023}, author = {Marshall-Hudson, A and Tuley, M and Damstra, M and Dosik, JS and Myntti, MF and Porral, D and Palomo, J}, title = {A 6-month, Multi-center, Double-blind, Controlled Study to Evaluate the Effect of a Biofilm Disrupting Acne Cream on Mild-to-Moderate Facial Acne in Female Volunteer Subjects.}, journal = {The Journal of clinical and aesthetic dermatology}, volume = {16}, number = {4}, pages = {43-52}, pmid = {37077927}, issn = {1941-2789}, abstract = {OBJECTIVES: The primary aim of this study was to assess the change in acne lesions and severity within all treatment groups over the course of a six-month study.<br><br>METHODS: This was a six-month, multisite, randomized, double-blind, controlled study in female subjects with mild-to-moderate acne to assess the clinical and psychological outcomes of treatment with biofilm disrupting acne cream 2x, biofilm disrupting acne cream 1x, biofilm disrupting acne cream without salicylic acid, 2.5% benzoyl peroxide (BPO) gel, and placebo. Subjects applied the assigned product to their face twice daily and were evaluated for clinical acne and quality of life outcomes at baseline and after six, 12, 18, and 24 weeks of treatment.<br><br>RESULTS: After 24 weeks of use, subjects treated with biofilm disrupting acne cream 2x had a significantly greater improvement in the Investigator Global Assessment (IGA), compared to those treated with 2.5% BPO gel. Based on dermatologic assessments, biofilm disrupting acne cream 2x, biofilm disrupting acne cream 1x, biofilm disrupting acne cream without salicylic acid, and placebo control were associated with less erythema and dryness, compared to 2.5% BPO gel.<br><br>LIMITATIONS: Assessments within this study had the potential for subjective differences due to variability between evaluators.<br><br>CONCLUCION: Biofilm disrupting acne cream 2x and biofilm disrupting acne cream 1x provided equivalent efficacy to 2.5% BPO gel with less of the adverse effects commonly associated with BPO, such as erythema and dryness. Both the biofilm disrupting acne cream without salicylic acid and the placebo control were associated with mild improvements to acne symptoms over the course of the 24-week study.<br><br>TRIAL REGISTRY INFORMATION: ClinicalTrials.gov, NCT03106766.}, }
@article {pmid37077117, year = {2023}, author = {Namazoğlu, B and Aksoy, M and Memiş-Özgül, B and Tulga-Öz, F}, title = {Anti-microbial efficiency of gaseous ozone's combined use with fluoride and chlorhexidine on time-related oral biofilm: an in situ study on pediatric patients.}, journal = {Medical gas research}, volume = {13}, number = {4}, pages = {192-197}, doi = {10.4103/2045-9912.372820}, pmid = {37077117}, issn = {2045-9912}, abstract = {Oral biofilm formation is the main reason for both caries progression and soft tissue diseases. Preventing the formation and promotion of biofilm has been known as the first attempt to prevent the development of caries and soft tissue problems in the oral cavity. The present study aimed to assess the effect of ozone and its combined use with chlorhexidine (CHX) and fluoride on the complex biofilm formation of pediatric patients under in situ conditions. Extracted bovine teeth were sterilized and cut into 2 × 3 mm[2] sections. The samples were placed in removable maxillary plates and 10 healthy individuals (6 boys, 4 girls; aged 7-14 years) were asked to wear these plates for 6, 24 and 48 hours. Afterwards, the tooth samples were removed, and anti-plaque agents were applied to the time-related plaque formation. Plaque thickness and viable bacterial percentages were detected by confocal laser scanning microscopy. All materials used in the study decreased the plaque formation and the percentage of viable microorganisms compared with the control group (physiological saline). In 6- and 24-hour biofilm evaluations, ozone-CHX was the most effective group in decreasing the plaque thickness (P > 0.05). Ozone-CHX and Ozone-Fluoride groups were found to be better in 48-hour biofilm assessments in caries-free group (P > 0.05). Ozone-CHX group showed a better inhibitory effect on the viability of microorganisms in 6-, 24- and 48-hour biofilm formations (P < 0.05). Although CHX has been known as the gold standard for inhibiting the oral biofilm formation, according to the results of the study, gaseous ozone and its combined use with CHX have shown better results in reducing the biofilm thickness and viable bacterial percentages of in situ formed time-related biofilm formation in pediatric patients. The use of gaseous ozone can be preferred in clinical conditions in pediatric patients instead of the CHX agents.}, }
@article {pmid37076397, year = {2023}, author = {Scavone, P and Iribarnegaray, V and González, MJ and Navarro, N and Caneles-Huerta, N and Jara-Wilde, J and Härtel, S and Zunino, P}, title = {Role of Proteus mirabilis flagella in biofilm formation.}, journal = {Revista Argentina de microbiologia}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.ram.2023.01.005}, pmid = {37076397}, issn = {0325-7541}, abstract = {Proteus mirabilis(P. mirabilis) is a common etiological agent of urinary tract infections, particularly those associated with catheterization. P. mirabilis efficiently forms biofilms on different surfaces and shows a multicellular behavior called 'swarming', mediated by flagella. To date, the role of flagella in P. mirabilis biofilm formation has been under debate. In this study, we assessed the role of P. mirabilis flagella in biofilm formation using an isogenic allelic replacement mutant unable to express flagellin. Different approaches were used, such as the evaluation of cell surface hydrophobicity, bacterial motility and migration across catheter sections, measurements of biofilm biomass and biofilm dynamics by immunofluorescence and confocal microscopy in static and flow models. Our findings indicate that P. mirabilis flagella play a role in biofilm formation, although their lack does not completely avoid biofilm generation. Our data suggest that impairment of flagellar function can contribute to biofilm prevention in the context of strategies focused on particular bacterial targets.}, }
@article {pmid37076015, year = {2023}, author = {Zhou, Q and Wang, T and Li, K and Zhang, S and Wang, K and Hong, W and Liu, R and Li, P}, title = {Biofilm microenvironment-responsive polymeric CO releasing micelles for enhanced amikacin efficacy.}, journal = {Journal of controlled release : official journal of the Controlled Release Society}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jconrel.2023.04.025}, pmid = {37076015}, issn = {1873-4995}, abstract = {Biofilm-associated infections (BAI) have posed serious threats to public health. Novel therapy based on carbon monoxide (CO) is being increasingly appreciated. However, CO therapy like inhaled gas treatment was impeded owing to its low bioavailability. Besides, the direct use of CO releasing molecules (CORM) showed low therapeutic efficacy in BAI. Therefore, it is vital to improve the efficiency of CO therapy. Herein, we proposed polymeric CO releasing micelles (pCORM) from self-assembly of amphiphilic polymer containing CORM bearing block as hydrophobic part and acryloylmorpholine block as hydrophilic part. The catechol modified CORM were conjugated through pH cleavable boronate ester bonds and releasing CO passively under biofilm microenvironment. When combined with subminimal inhibitory concentration antibiotic amikacin, pCORM could significantly enhance its bactericidal efficiency against biofilm-encapsulated multidrug-resistant bacteria, representing a promising approach to combat BAI.}, }
@article {pmid37075926, year = {2023}, author = {Rao Tatta, E and Paul, S and Kumavath, R}, title = {Transcriptome Analysis revealed the Synergism of Novel Rhodethrin inhibition on Biofilm architecture, Antibiotic Resistance and Quorum sensing inEnterococcus faecalis.}, journal = {Gene}, volume = {}, number = {}, pages = {147436}, doi = {10.1016/j.gene.2023.147436}, pmid = {37075926}, issn = {1879-0038}, abstract = {Enterococcus sp. emerged as an opportunistic nosocomial pathogen with the highest antibiotic resistance and mortality rate. Biofilm is problematic primarily since it is regulated by the global bacterial cell to cell communication mediated by the quorum sensing system. sing system. Thus, potential natural antagonists in a novel drug formulation against biofilm-forming Enterococcus faecalis is critical. We used RNA-Seq to evaluate the effects of the novel molecule rhodethrin with chloramphenicol induced on Enterococcus faecalis and DEGs were identified. In transcriptome sequence analysis, a total of 448 with control Vs rhodethrin, 1591 were in control Vs chloramphenicol, 379 genes were DEGs from control Vs synergies, in rhodethrin with chloramphenicol, 379 genes were differentially expressed, whereas 264 genes were significantly downregulated, indicating that 69.69% ofE. faecaliswas altered. The transcriptional sequence data further expression analysis qRT-PCR, and the results shed that the expression profiles of five significant biofilm formation responsible genes such as, Ace, AtpB, lepA, bopD, and typA, 3 genes involved in quorum sensing are sylA, fsrC and camE, and 4 genes involved in resistance were among including liaX, typA, EfrA, and lepA, were significantly suppressed expressions of the biofilm, quorum sensing, and resistance that are supported by transcriptome analysis.}, }
@article {pmid37074383, year = {2023}, author = {Chen, X and Xiao, L and Niu, J and Wang, Y and Zhang, X and Gong, L and Yao, F and Xu, K}, title = {Early succession of biofilm bacterial communities in newly built drinking water pipelines via multi-area analysis.}, journal = {Applied microbiology and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {37074383}, issn = {1432-0614}, abstract = {Biofilms inhabiting pipeline walls are critical to drinking water quality and safety. With massive pipeline replacement underway, however, biofilm formation process in newly built pipes and its effects on water quality are unclear. Moreover, differences and connections between biofilms in newly built and old pipes are unknown. In this study, early succession (≤ 120 days) of biofilm bacterial communities (abundance and diversity) in upper, middle and bottom areas of a newly built cement-lined ductile iron pipeline were evaluated using improved Propella™ biofilm reactor and multi-area analysis. A comparison with old pipelines (grey cast iron, 10 years) was performed. In the newly built pipeline, the abundance of biofilm bacteria did not change significantly between 40 and 80 days, but increased significantly between 80 and 120 days. The biofilm bacterial abundance (per unit area) in the bottom area was always higher than that in the upper and middle areas. Based on alpha diversity index and PCoA results, biofilm bacterial community richness, diversity and composition did not change significantly during the 120-day operation. Besides, biofilm shedding from the walls of newly built pipeline significantly increased bacterial abundance in the outlet water. Opportunistic pathogen-containing genera, such as Burkholderia, Acinetobacter and Legionella, were identified in both water and biofilm samples from newly built pipelines. The comparison between new and old pipelines suggested a higher bacterial abundance per unit area at the middle and bottom areas in old pipelines. Moreover, the bacterial community composition of biofilms in old pipelines was similar to that of newly built pipelines. These results contribute to accurate prediction and management of biofilm microbial communities in drinking water pipelines, ensuring the biosafety of drinking water. KEY POINTS: • Biofilm bacterial communities in different areas of pipe wall were revealed. • The abundance of biofilm bacteria increased significantly between 80 and 120 days. • Biofilm bacterial community compositions of newly built and old pipes were similar.}, }
@article {pmid37073912, year = {2022}, author = {Goutham, PAJ and Kalaiselvam, R and Ganesh, A and C, BP}, title = {Antibacterial Efficacy of Irrigants with Varying Osmolarity on E. faecalis Biofilm: An In Vitro Study.}, journal = {The journal of contemporary dental practice}, volume = {23}, number = {10}, pages = {998-1003}, doi = {10.5005/jp-journals-10024-3417}, pmid = {37073912}, issn = {1526-3711}, mesh = {*Sodium Chloride/pharmacology ; *Root Canal Irrigants/pharmacology ; Chlorhexidine/pharmacology ; Anti-Bacterial Agents/pharmacology ; Biofilms ; Enterococcus faecalis ; Sodium Hypochlorite/pharmacology ; Dental Pulp Cavity/microbiology ; }, abstract = {AIM: To evaluate the role of the addition of different concentrations of sodium chloride salt to conventional intracanal irrigants to vary their osmotic values and thereby compare their antibacterial efficacy.<br><br>MATERIALS AND METHODS: In an active attachment biofilm model, Enterococcus faecalis (ATCC 29212) biofilms were grown. Sodium chloride salts were added to 100 mL of distilled water to make 6M (hyperosmotic), 0.5M, and 0.25M (hypoosmotic) sodium chloride solutions, respectively. The experimental groups were divided into three groups: Group I: 5.25% sodium hypochlorite, group II: 2% chlorhexidine, and group III: 2% povidone iodine, and four subgroups within these three groups, such as subgroup A (without salt solution), subgroup B (with 6M of hyperosmotic salt solution), subgroup C (with 0.5M of hypoosmotic salt solution), and subgroup D (with 0.25M of hypoosmotic salt solution), respectively. Biofilms were treated with all the subgroups for a contact time of 15 min. A crystal violet assay was done to estimate the bacterial cell biomass.<br><br>RESULTS: The results revealed that subgroups IIIB, IB, and IID, ID had a statistical reduction in bacterial biomass at p < 0.05. There were no significant differences between subgroups IC, IIC, and IIIC and subgroups IA, IIA, and IIIA.<br><br>CONCLUSION: The antibacterial efficacy of all three irrigants was significantly affected by varying the osmolarities.<br><br>CLINICAL SIGNIFICANCE: The results prove that the hyperosmotic and hypoosmotic salt solutions, along with irrigants, have enhanced antibacterial efficacy on E. faecalis biofilm due to its ability to vary the turgor pressure of cell wall, as well as the inherent properties of the irrigants such as hypochlorous acid formation, ionic interaction, and free radical interactions.}, }
@article {pmid37073093, year = {2023}, author = {Kıvanç, SA and Akova, B and Kıvanç, M}, title = {Effects of the Dibenzofuran, Usnic Acid, on Inhibition of Ocular Biofilm Formation Due to Coagulase-Negative Staphylococci.}, journal = {Medical science monitor : international medical journal of experimental and clinical research}, volume = {29}, number = {}, pages = {e940266}, doi = {10.12659/MSM.940266}, pmid = {37073093}, issn = {1643-3750}, mesh = {Humans ; *Coagulase/pharmacology ; *Staphylococcal Infections/microbiology ; Anti-Bacterial Agents/pharmacology ; Dibenzofurans/pharmacology ; Biofilms ; Microbial Sensitivity Tests ; }, abstract = {BACKGROUND Coagulase-negative staphylococci (CoNS) are gram-positive, aerobic, commensal bacteria found on the skin and mucus membranes, including the conjunctiva. Usnic acid (UA) is a dibenzofuran derivative isolated from lichens. This study aimed to investigate the effects of usnic acid on inhibition of ocular biofilm formation due to CoNS. MATERIAL AND METHODS Nine Staphylococcus epidermidis isolates, 5 Staphylococcus hominis isolates, 2 Staphylococcus saprophyticus isolates, and 1 Staphylococcus capitis and Staphylococcus lentus isolates were taken as test bacteria. They were inoculated into brain heart infusion broth and incubated for 24 hours at 35°C and activated. Antibiotic susceptibility was investigated by Kirby-Bauer disc diffusion method. Biofilm production was determined using the microtiter plate method and optical densitometry was measured at 570 nm using an automated microplate reader. Anti-biofilm activity of UA was determined by microtitration method and biofilm removal percentage was calculated. RESULTS All tested bacteria were found as high biofilm-producer strains; they were generally resistant to methicillin, but susceptible to vancomycin. UA inhibited the biofilm formation of S. epidermidis isolates, ranging from 5.7% to 81.5%. It inhibited the biofilm formation of S. saprophyticus and S. lentus by 73.3% and 74.3%, respectively. There was no effect of UA on mature biofilms of S. epidermidis 17.7H, S. epidermidis 15.41, S. hominis 9.3, S. hominis 17.2H, S. saprophyticus, and S. lentus. CONCLUSIONS It was determined that UA exerted anti-biofilm activity on some CoNS isolated from the ocular surface. Anti-biofilm activity was found to be higher even in strains that did not show antibacterial activity.}, }
@article {pmid37071524, year = {2023}, author = {Esfahani, MB and Khodavandi, A and Alizadeh, F and Bahador, N}, title = {Antibacterial and Anti-Biofilm Activities of Microbial Synthesized Silver and Magnetic Iron Oxide Nanoparticles against Pseudomonas aeruginosa.}, journal = {IEEE transactions on nanobioscience}, volume = {PP}, number = {}, pages = {}, doi = {10.1109/TNB.2023.3268138}, pmid = {37071524}, issn = {1558-2639}, abstract = {Pseudomonas aeruginosa is a human bacterial pathogen causing devastating diseases and equipped with various virulence factors like biofilm formation. Common antibiotic treatment has limited efficacy for the P. aeruginosa present in biofilms because of the increased resistance. In this study, we focused our attention on the antibacterial and anti-biofilm activities of various microbial synthesized silver (nano-Ag) and magnetic iron oxide (nano-Fe3O4) nanoparticles against clinical isolates of P. aeruginosa that displayed ceftazidime resistance. The nano-Ag and nano-Fe3O4 represented great antibacterial properties. Nano-Ag and nano-Fe3O4 exhibited a reduction in the biofilm formation by P. aeruginosa reference strain as determined by crystal violet and XTT assays and light microscopy method. Among all, nano-Ag-2 and 7 owing to inherent attributes and mechanisms of resistance in the bacterial biofilm, exhibited anti-biofilm efficacy against ceftazidime resistance clinical isolate of P. aeruginosa. Moreover, nano-Ag and nano-Fe3O4 changed the relative expression of biofilm-associated genes, PELA and PSLA in a concentration dependent manner by P. aeruginosa reference strain. As revealed by qRT-PCR, the expression levels of biofilm-associated genes were downregulated in P. aeruginosa biofilms treated with nano-Ag, while selected biofilm-associated genes were low expressed under treated with nano-Fe3O4. Results of the study demonstrate the potential of microbial synthesized nano-Ag-2 and 7 to act as anti-biofilm agents against ceftazidime resistance clinical isolate of P. aeruginosa. Molecular targeting of biofilm-associated genes by nano-Ag and nano-Fe3O4 may be candidate for new therapeutics against P. aeruginosa diseases.}, }
@article {pmid37070220, year = {2023}, author = {Chen, Q and Zhang, X and Wang, Q and Yang, J and Zhong, Q}, title = {The mixed biofilm formed by Listeria monocytogenes and other bacteria: Formation, interaction and control strategies.}, journal = {Critical reviews in food science and nutrition}, volume = {}, number = {}, pages = {1-17}, doi = {10.1080/10408398.2023.2200861}, pmid = {37070220}, issn = {1549-7852}, abstract = {Listeria monocytogenes is an important foodborne pathogen. It can adhere to food or food contact surface for a long time and form biofilm, which will lead to equipment damage, food deterioration, and even human diseases. As the main form of bacteria to survive, the mixed biofilms often exhibit higher resistance to disinfectants and antibiotics, including the mixed biofilms formed by L. monocytogenes and other bacteria. However, the structure and interspecific interaction of the mixed biofilms are very complex. It remains to be explored what role the mixed biofilm could play in the food industry. In this review, we summarized the formation and influence factors of the mixed biofilm developed by L. monocytogenes and other bacteria, as well as the interspecific interactions and the novel control measures in recent years. Moreover, the future control strategies are prospected, in order to provide theoretical basis and reference for the research of the mixed biofilms and the targeted control measures.}, }
@article {pmid37070126, year = {2023}, author = {Pei, ZJ and Li, C and Dai, W and Lou, Z and Sun, X and Wang, H and Khan, AA and Wan, C}, title = {The Anti-Biofilm Activity and Mechanism of Apigenin-7-O-Glucoside Against Staphylococcus aureus and Escherichia coli.}, journal = {Infection and drug resistance}, volume = {16}, number = {}, pages = {2129-2140}, pmid = {37070126}, issn = {1178-6973}, abstract = {INTRODUCTION: This study aimed to examine the anti-biofilm activity and mechanism of gallic acid (GA), kaempferol-7-O-glucoside (K7G) and apigenin-7-O-glucoside (A7G) against Staphylococcus aureus and Escherichia coli.<br><br>METHODS: The antibacterial activity of the natural compounds was determined by serial dilution method. The inhibitory activity of natural compounds on biofilms was determined by crystal violet staining method. The effects and mechanisms of natural compounds on bacterial biofilms were analyzed by atomic force microscopy.<br><br>RESULTS: In our study, compared with GA and K7G, A7G was found to exhibit the strongest anti-biofilm and antibacterial activities. The minimum biofilm inhibitory concentration (MBIC) of A7G against S. aureus and E. coli was 0.20 mg/mL and 0.10 mg/mL, respectively. The inhibition rates of 1/2 MIC of A7G on biofilms of S. aureus and E. coli were 88.9%, and 83.2% respectively. Moreover, atomic force microscope (AFM) images showed the three-dimensional biofilm morphology of S. aureus and E. coli, and the results indicated that A7G was highly effective in biofilm inhibition.<br><br>DISCUSSION: It was found that the inhibition of A7G on biofilm was achieved through inhibiting on exopolysaccharides (EPS), quorum sensing (QS), and cell surface hydrophobicity (CSH). A7G exerted strong anti-biofilm activities by inhibiting EPS production, QS, and CSH. Hence, A7G, as a natural substance, could be a promising novel antibacterial and anti-biofilm agent for control of biofilm in food industry.}, }
@article {pmid37069901, year = {2023}, author = {Naisi, S and Bayat, M and Zahraei Salehi, T and Rahimian Zarif, B and Yahyaraeyat, R}, title = {Antimicrobial and anti-biofilm effects of carotenoid pigment extracted from Rhodotorula glutinis strain on food-borne bacteria.}, journal = {Iranian journal of microbiology}, volume = {15}, number = {1}, pages = {79-88}, pmid = {37069901}, issn = {2008-3289}, abstract = {BACKGROUND AND OBJECTIVES: Carotenoid pigments are among the most important pigments and have many applications in various food, cosmetics, hygiene industries and biotechnology. These pigments are produced by plants and microorganisms including Rhodotorula spp. This research intended to study the antimicrobial and antibiofilm effects of the carotenoid pigment from Rhodotorula glutinis on food spoilage bacteria (Staphylococcus aureus and Salmonella Typhimurium).<br><br>MATERIALS AND METHODS: The R. glutinis was isolated from milk samples of cows with mastitis and ITS sequence-based typing was performed on them. After extracting the pigment from R. glutinis, its purity was examined using thin-layer chromatography. Following that, the broth microdilution method was used to evaluate antimicrobial effects of the pigment and MtP assay and subsequently scanning electron microscopy were used to assess the antibiofilm effects. In addition, the sub-MIC effects of the pigment on expression of quorum-sensing (QS) genes in S. Typhimurium isolates (sdiA and luxS) and S. aureus isolates (hld) were studied. Finally, the degree of toxicity of the pigment was analyzed using the MTT assay.<br><br>RESULTS: ITS sequence analysis of R. glutinis revealed that the recently separated isolates exhibited strong differences with the strains recorded in NCBI database in genetic structure. The pigment produced by R. glutinis had strong antimicrobial effects and its mean MIC against S. Typhimurium isolates (17.0 &#x3bc;l.ml[-1]) was higher than the mean MIC against the S. aureus isolates (4.1 &#x3bc;l.ml[-1]). Electron microscope images and real-time observations indicated that the sub-MIC values of the pigment suppressed biofilm formation by suppressing expression of QS genes. In addition, the mentioned pigment at high MIC concentrations did not have toxic effects on Vero cells.<br><br>CONCLUSION: This research suggests that R. glutinis pigment is effective in destroying the planktonic form of food spoilage bacteria and degrading food spoilage biofilm-forming bacteria. Moreover, considering the low toxicity level of R. glutinis pigment for eukaryotic cells, we can suggest its use as a natural antibacterial preservative in various food materials.}, }
@article {pmid37066293, year = {2023}, author = {Huang, Y and Liu, Y and Pandey, N and Shah, S and Simon-Soro, A and Hsu, J and Ren, Z and Xiang, Z and Kim, D and Ito, T and Oh, MJ and Buckley, C and Alawi, F and Li, Y and Smeets, P and Boyer, S and Zhao, X and Joester, D and Zero, D and Cormode, D and Koo, H}, title = {Iron oxide nanozymes stabilize stannous fluoride for targeted biofilm killing and synergistic oral disease prevention.}, journal = {Research square}, volume = {}, number = {}, pages = {}, doi = {10.21203/rs.3.rs-2723097/v1}, pmid = {37066293}, abstract = {Dental caries (tooth decay) is the most prevalent human disease caused by oral biofilms, affecting nearly half of the global population despite increased use of fluoride, the mainstay anticaries (tooth-enamel protective) agent. Recently, an FDA-approved iron oxide nanozyme formulation (ferumoxytol, Fer) has been shown to disrupt caries-causing biofilms with high specificity via catalytic activation of hydrogen peroxide, but it is incapable of interfering with enamel acid demineralization. Here, we find notable synergy when Fer is combined with stannous fluoride (SnF 2), markedly inhibiting both biofilm accumulation and enamel damage more effectively than either alone. Unexpectedly, our data show that SnF 2 enhances the catalytic activity of Fer, significantly increasing reactive oxygen species (ROS) generation and antibiofilm activity. We discover that the stability of SnF 2 (unstable in water) is markedly enhanced when mixed with Fer in aqueous solutions without any additives. Further analyses reveal that Sn [2+] is bound by carboxylate groups in the carboxymethyl-dextran coating of Fer, thus stabilizing SnF 2 and boosting the catalytic activity. Notably, Fer in combination with SnF 2 is exceptionally effective in controlling dental caries in vivo , preventing enamel demineralization and cavitation altogether without adverse effects on the host tissues or causing changes in the oral microbiome diversity. The efficacy of SnF 2 is also enhanced when combined with Fer, showing comparable therapeutic effects at four times lower fluoride concentration. Enamel ultrastructure examination shows that fluoride, iron, and tin are detected in the outer layers of the enamel forming a polyion-rich film, indicating co-delivery onto the tooth surface. Overall, our results reveal a unique therapeutic synergism using approved agents that target complementary biological and physicochemical traits, while providing facile SnF 2 stabilization, to prevent a widespread oral disease more effectively with reduced fluoride exposure.}, }
@article {pmid37064802, year = {2023}, author = {Ma, H and Tang, Y and Rong, F and Wang, K and Wang, T and Li, P}, title = {Surface charge adaptive nitric oxide nanogenerator for enhanced photothermal eradication of drug-resistant biofilm infections.}, journal = {Bioactive materials}, volume = {27}, number = {}, pages = {154-167}, pmid = {37064802}, issn = {2452-199X}, abstract = {Due to protection of extracellular polymeric substances, the therapeutic efficiency of conventional antimicrobial agents is often impeded by their poor infiltration and accumulation in biofilm. Herein, one type of surface charge adaptable nitric oxide (NO) nanogenerator was developed for biofilm permeation, retention and eradication. This nanogenerator (PDG@Au-NO/PBAM) is composed of a core-shell structure: thermo-sensitive NO donor conjugated AuNPs on cationic poly(dopamine-co-glucosamine) nanoparticle (PDG@Au-NO) served as core, and anionic phenylboronic acid-acryloylmorpholine (PBAM) copolymer was employed as a shell. The NO nanogenerator featured long circulation and good biocompatibility. Once the nanogenerator reached acidic biofilm, its surface charge would be switched to positive after shell dissociation and cationic core exposure, which was conducive for the nanogenerator to infiltrate and accumulate in the depth of biofilm. In addition, the nanogenerator could sustainably generate NO to disturb the integrity of biofilm at physiological temperature, then generate hyperthermia and explosive NO release upon NIR irradiation to efficiently eradicate drug-resistant bacteria biofilm. Such rational design offers a promising approach for developing nanosystems against biofilm-associated infections.}, }
@article {pmid37064519, year = {2023}, author = {Maggio, F and Serio, A and Rossi, C and Purgatorio, C and Buccioni, F and Chaves-López, C and Paparella, A}, title = {Effectiveness of essential oils against dual-species biofilm of Listeria monocytogenes and Pseudomonas fluorescens in a Ricotta-based model system.}, journal = {Italian journal of food safety}, volume = {12}, number = {1}, pages = {11048}, pmid = {37064519}, issn = {2239-7132}, abstract = {Biofilms represent an evolutionary form of life, which translates from life in free-living cells to a community lifestyle. In natural habitats, biofilms are a multispecies complex, where synergies or antagonisms can be established. For example, Listeria monocytogenes and Pseudomonas fluorescens are associated with a dual-species biofilm that is widespread in dairy plants. In food plants, multiple strategies are devised to control biofilms, including natural compounds such as essential oils (EOs). In this respect, this study evaluated the effectiveness of Thymbra capitata (L.) Cav. (TEO) and Cinnamomum zeylanicum (CEO) against a dual-species biofilm of L. monocytogenes and P. fluorescens, mimicking dairy process conditions. Based on Minimum Inhibitory Concentrations results, the EOs concentration (10 μL/mL) was chosen for the antibiofilm assay at 12°C on polystyrene (PS), and stainless-steel surfaces for 168 h, using a Ricotta-based model system as culture medium. Biofilm biomass was assessed by crystal violet staining, and the planktonic and sessile cells were quantified in terms of Log CFU/cm[2]. Results showed that CEO displayed the greatest antibiofilm activity, reducing significantly (P<0.05) P. fluorescens and L. monocytogenes sessile cells of about 2.5 and 2.8 Log CFU/cm[2] after 72 h, respectively. However, L. monocytogenes gained the protection of P. fluorescens, evading CEO treatment and showing a minimal sessile cell reduction of 0.7 Log CFU/cm[2] after 72 h. Considering the outcome of this study, CEO might have promising perspectives for applications in dairy facilities.}, }
@article {pmid37060635, year = {2023}, author = {Akbarzadeh, I and Rezaei, N and Bazzazan, S and Mezajin, MN and Mansouri, A and Karbalaeiheidar, H and Ashkezari, S and Moghaddam, ZS and Lalami, ZA and Mostafavi, E}, title = {In silico and in vitro studies of GENT-EDTA encapsulated niosomes: A novel approach to enhance the antibacterial activity and biofilm inhibition in drug-resistant Klebsiella pneumoniae.}, journal = {Biomaterials advances}, volume = {149}, number = {}, pages = {213384}, doi = {10.1016/j.bioadv.2023.213384}, pmid = {37060635}, issn = {2772-9508}, abstract = {Klebsiella pneumoniae (Kp) is a common pathogen inducing catheter-related biofilm infections. Developing effective therapy to overcome antimicrobial resistance (AMR) in Kp is a severe therapeutic challenge that must be solved. This study aimed to prepare niosome-encapsulated GENT (Gentamicin) and EDTA (Ethylenediaminetetraacetic acid) (GENT-EDTA/Nio) to evaluate its efficacy toward Kp strains. The thin-film hydration method was used to prepare various formulations of GENT-EDTA/Nio. Formulations were characterized for their physicochemical characteristics. GENT-EDTA/Nio properties were used for optimization with Design-Expert Software. Molecular docking was utilized to determine the antibacterial activity of GENT. The niosomes displayed a controlled drug release and storage stability of at least 60 days at 4 and 25 °C. GENT-EDTA/Nio performance as antimicrobial agents has been evaluated by employing agar well diffusion method, minimum bactericidal concentration (MBC), and minimum inhibitory concentration (MIC) against the Kp bacteria strains. Biofilm formation was investigated after GENT-EDTA/Nio administration through different detection methods, which showed that this formulation reduces biofilm formation. The effect of GENT-EDTA/Nio on the expression of biofilm-related genes (mrkA, ompA, and vzm) was estimated using QRT-PCR. MTT assay was used to evaluate the toxicity effect of niosomal formulations on HFF cells. The present study results indicate that GENT-EDTA/Nio decreases Kp's resistance to antibiotics and increases its antibiotic and anti-biofilm activity and could be helpful as a new approach for drug delivery.}, }
@article {pmid37059195, year = {2023}, author = {Gholipour, S and Shamsizadeh, Z and Gwenzi, W and Nikaeen, M}, title = {The bacterial biofilm resistome in drinking water distribution systems: A systematic review.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138642}, doi = {10.1016/j.chemosphere.2023.138642}, pmid = {37059195}, issn = {1879-1298}, abstract = {Antibiotic resistance in drinking water systems poses human health risks. Earlier studies, including reviews on antibiotic resistance in drinking water systems are limited to the occurrence, behaviour and fate in bulk raw water and drinking water treatment systems. By comparison, reviews on the bacterial biofilm resistome in drinking water distribution systems are still limited. Therefore, the present systematic review investigates the occurrence, behaviour and fate and, detection methods of bacterial biofilm resistome in the drinking water distribution systems. A total of 12 original articles drawn from 10 countries were retrieved and analyzed. Antibiotic resistant bacteria and antibiotic resistance genes detected in biofilms include those for sulfonamides, tetracycline, and beta-lactamase. The genera detected in biofilms include Staphylococcus, Enterococcus, Pseudomonas, Ralstonia, Mycobacteria, as well as Enterobacteriaceae family and other gram-negative bacteria. The presence of Enterococcus faecium, S. aureus, Klebsiella pneumoniae, A. baumannii, Pseudomonas aeruginosa, and Enterobacter species (ESKAPE bacteria) among the detected bacteria points to potential human exposure and health risks especially for susceptible individuals via the consumption of drinking water. Besides, the effects of water quality parameter and residual chlorine, the physico-chemical factors controlling the emergence, persistence and fate of the biofilm resistome are still poorly understood. Culture-based methods, and molecular methods, and their advantages and limitations are discussed. The limited data on the bacterial biofilm resistome in drinking water distribution system points to the need for further research. To this end, future research directions are discussed including understanding the formation, behaviour, and fate of the resistome and the controlling factors.}, }
@article {pmid37058918, year = {2023}, author = {Zhao, Q and Li, J and Deng, L and Jia, T and Zhao, Y and Li, X and Peng, Y}, title = {From hybrid process to pure biofilm anammox process: Suspended sludge biomass management contributing to high-level anammox enrichment in biofilms.}, journal = {Water research}, volume = {236}, number = {}, pages = {119959}, doi = {10.1016/j.watres.2023.119959}, pmid = {37058918}, issn = {1879-2448}, abstract = {The application of mainstream anammox is highly desirable for municipal wastewater treatment. However, enrichment of anammox bacteria (AnAOB) is challenging, particularly given the vicious competition from denitrifying bacteria (DB). Here, suspended sludge biomass management, a novel operational strategy for hybrid process (suspended sludge/biofilm), was investigated for 570 days based on a modified anaerobic-anoxic-oxic system treating municipal wastewater. By successively decreasing the suspended sludge concentration, the traditional hybrid process was successfully upgraded to a pure biofilm anammox process. During this process, both the nitrogen removal efficiency (NRE) and rate (NRR) were significantly improved (P < 0.001), from 62.1 ± 4.5% to 79.2 ± 3.9% and from 48.7 ± 9.7 to 62.3 ± 9.0 g N/(m[3]·d), respectively. Mainstream anammox was improved in the following: Candidatus Brocadia was enriched from 0.70% to 5.99% in anoxic biofilms [from (9.94 ± 0.99) × 10[8] to (1.16 ± 0.01) × 10[10] copies/g VSS, P < 0.001]; the in situ anammox reaction rate increased from 8.8 ± 1.9 to 45.5 ± 3.2 g N/(m[3]·d) (P < 0.001); the anammox contribution to nitrogen removal rose from 9.2 ± 2.8% to 67.1 ± 8.3% (P < 0.001). Core bacterial microbiome analysis, functional gene quantification, and a series of ex situ batch experiments demonstrated that the stepwise decreases in suspended sludge concentration effectively mitigated the vicious competition of DB against AnAOB, enabling high-level AnAOB enrichment. This study presents a straightforward and effective strategy for enriching AnAOB in municipal wastewater, shedding fresh light on the application and upgradation of mainstream anammox.}, }
@article {pmid37058467, year = {2023}, author = {Böhning, J and Dobbelstein, AW and Sulkowski, N and Eilers, K and von Kügelgen, A and Tarafder, AK and Peak-Chew, SY and Skehel, M and Alva, V and Filloux, A and Bharat, TAM}, title = {Architecture of the biofilm-associated archaic Chaperone-Usher pilus CupE from Pseudomonas aeruginosa.}, journal = {PLoS pathogens}, volume = {19}, number = {4}, pages = {e1011177}, pmid = {37058467}, issn = {1553-7374}, support = {202231/Z/16/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Humans ; *Pseudomonas aeruginosa/metabolism ; *Fimbriae, Bacterial/metabolism ; Biofilms ; Adhesins, Bacterial/metabolism ; Molecular Chaperones/metabolism ; Fimbriae Proteins/metabolism ; }, abstract = {Chaperone-Usher Pathway (CUP) pili are major adhesins in Gram-negative bacteria, mediating bacterial adherence to biotic and abiotic surfaces. While classical CUP pili have been extensively characterized, little is known about so-called archaic CUP pili, which are phylogenetically widespread and promote biofilm formation by several human pathogens. In this study, we present the electron cryomicroscopy structure of the archaic CupE pilus from the opportunistic human pathogen Pseudomonas aeruginosa. We show that CupE1 subunits within the pilus are arranged in a zigzag architecture, containing an N-terminal donor β-strand extending from each subunit into the next, where it is anchored by hydrophobic interactions, with comparatively weaker interactions at the rest of the inter-subunit interface. Imaging CupE pili on the surface of P. aeruginosa cells using electron cryotomography shows that CupE pili adopt variable curvatures in response to their environment, which might facilitate their role in promoting cellular attachment. Finally, bioinformatic analysis shows the widespread abundance of cupE genes in isolates of P. aeruginosa and the co-occurrence of cupE with other cup clusters, suggesting interdependence of cup pili in regulating bacterial adherence within biofilms. Taken together, our study provides insights into the architecture of archaic CUP pili, providing a structural basis for understanding their role in promoting cellular adhesion and biofilm formation in P. aeruginosa.}, }
@article {pmid37057638, year = {2023}, author = {Singha, S and Thomas, R and Kumar, A and Bharadwaj, D and Vishwakarma, JN and Gupta, VK}, title = {Presence of potent inhibitors of bacterial biofilm associated proteins is the key to Citrus limon's antibiofilm activity against pathogenic Escherichia coli.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-18}, doi = {10.1080/08927014.2023.2199934}, pmid = {37057638}, issn = {1029-2454}, abstract = {In an era of antibiotic resistance where natural antibiotic substitutes are considered essential, the antimicrobial and antibiofilm activities of Citrus limon extract on strains of pathogenic Escherichia coli isolated from pork were evaluated. The strains which form biofilms were more resistant (MIC50 = 2.5 mgml[-1]) compared to non-biofilm forming strains (MIC50 = 1.25 mgml[-1]). Use of C. limon extract at 20 mgml[-1] concentration has resulted in inhibition of biofilm formation by 53.96%. Cyclobarbital, 5, 8-dimethoxycumarin, orotic acid and 3-methylsalicylhydrazide were the major phytochemicals in C. limon extract with highest docking affinities against the biofilm associated proteins in E. coli. The results of simulation studies have clearly illustrated the energy stability of the protein-ligand complexes. Absorption, distribution, metabolism, excretion and toxicity (ADMET) profiles revealed that the phytochemicals in C. limon could be used in the drug design studies to preferentially target the specific receptors to combat biofilms associated with E. coli.}, }
@article {pmid37057584, year = {2022}, author = {Narasimman, M and Ory, J and Bartra, SS and Plano, GV and Ramasamy, R}, title = {Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis.}, journal = {The journal of sexual medicine}, volume = {19}, number = {6}, pages = {1024-1031}, doi = {10.1016/j.jsxm.2022.03.602}, pmid = {37057584}, issn = {1743-6109}, mesh = {Humans ; *Penile Prosthesis/microbiology ; Rifampin/therapeutic use ; Staphylococcus aureus ; Gentian Violet ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Biofilms ; Gentamicins/pharmacology ; Bacteria ; Postoperative Complications/drug therapy ; }, abstract = {BACKGROUND: Delayed infection, thought to be due to gradual biofilm formation, remains a feared complication after inflatable penile prosthesis (IPP) insertion. Understanding and preventing biofilm formation is necessary to prevent infections.<br><br>AIM: To develop an in vitro model and compare growth of biofilm by different bacteria on IPPs and evaluate the anti-infective efficacy of the Coloplast Titan and AMS 700 InhibiZone.<br><br>METHODS: Sterile IPPs (Coloplast) were cut into rings and incubated with S. epidermidis, S. aureus, P. aeruginosa, A. baumannii, or K. pneumoniae cultures in tryptic soy broth (TSB) (4 hour) to ensure adequate bacteria attachment, and then in only TSB (120 hours) to allow for biofilm formation. Rings were fixed with ethanol and biofilm measured by spectrophotometer (OD570) after crystal violet staining. This methodology was repeated for S. epidermidis and P. aeruginosa with Coloplast rings dipped in 10 ml of a 10 mg/ml Rifampin, 1 mg/ml Gentamicin, and deionized water solution and undipped AMS InhibiZone rings. Crystal violet assay (OD570) was repeated after incubation within bacteria (2 hour), and then only TSB (120 hours).<br><br>OUTCOMES: The primary outcome of the study was OD570 readings, indirectly measuring biofilm mass on implant rings.<br><br>RESULTS: S. epidermidis, S. aureus, A. baumannii, P. aeruginosa, and K. pneumoniae all formed significant biofilm. P. aeruginosa showed the strongest predilection to grow biofilm on IPPs. P. aeruginosa also formed significant biofilm on antibiotic-treated Coloplast and AMS rings, while S. epidermidis was inhibited. No significant difference was found in biofilm inhibition between the implants.<br><br>CLINICAL TRANSLATION: Our findings suggest gram-negative bacteria may form biofilm more proficiently and quickly on IPPs than gram-positive organisms. Commonly used antibiotic treatments on IPPs may be effective against S. epidermidis but not against P. aeruginosa biofilm formation.<br><br>STRENGTHS &amp; LIMITATIONS: This is the first study comparing biofilm formation by different bacteria organisms on IPPs and the inhibitive ability of Coloplast and AMS implants against biofilm formation. Clinical data on organisms responsible for infected IPPs is needed to determine the clinical relevance of our findings.<br><br>CONCLUSION: Our novel in vitro model of biofilm formation of IPPs evaluated the effect of a gentamicin/rifampin antibiotic dip on Coloplast Titan implants and the anti-infective capacity of the minocycline/rifampin precoated AMS 700 InhibiZone against S. epidermidis and P. aeruginosa. P. aeruginosa was able to grow on both antibiotic-treated implants, with no significant difference, and should continue to be a specific target of investigation to reduce delayed post-operative IPP infections.}, }
@article {pmid37057221, year = {2023}, author = {Saidi, N and Saderi, H and Owlia, P and Soleimani, M}, title = {Anti-Biofilm Potential of Lactobacillus casei and Lactobacillus rhamnosus Cell-Free Supernatant Extracts against Staphylococcus aureus.}, journal = {Advanced biomedical research}, volume = {12}, number = {}, pages = {50}, pmid = {37057221}, issn = {2277-9175}, abstract = {BACKGROUND: Biofilm production is an important virulence factor in Staphylococcus aureus. Most of the infections associated with biofilms of this bacterium are very difficult to treat using antibiotics. The present research studied the effects of the two probiotic Lactobacillus species L. casei and L. rhamnosus on S. aureus biofilm.<br><br>MATERIALS AND METHODS: Cell-free supernatant (CFS) extracts of L. casei ATCC 39392 and L. rhamnosus ATCC 7469 culture were prepared. The effects of sub-minimum inhibitory concentrations of the CFS extracts on cell surface hydrophobicity (CSH), initial attachment, biofilm formation, and their ability in eradicating S. aureus ATCC 33591 biofilms were assessed. In addition, the effects of CFS extracts on expression of the genes involved in formation of S. aureus biofilms (cidA, hld, sarA, icaA, and icaR) were also evaluated through real-time polymerase chain reaction.<br><br>RESULTS: CFSs of both Lactobacillus spp. significantly reduced CSH, initial attachment, and biofilm formation and eradicated the biofilms. The above findings were supported by scanning electron microscopy results. These two Lactobacillus CFSs significantly changed the expression of all studied biofilm-related genes. Expression levels of cidA, hld, and icaR genes significantly increased by 4.4, 2.3, and 4.76 fold, respectively, but sarA and icaA genes were significantly downregulated by 3.12 and 2.3 fold.<br><br>CONCLUSION: The results indicated that CFS extracts of L. casei and L. rhamnosus had desirable antagonistic and anti-biofilm effects against S. aureus. Consequently, carrying out further research enables us to prepare pharmaceuticals from these CFSs in order to prevent and treat infections caused by S. aureus biofilms.}, }
@article {pmid37056424, year = {2023}, author = {Xu, Q and Chen, S and Jiang, L and Xia, C and Zeng, L and Cai, X and Jin, Z and Qin, S and Ding, W and He, Q}, title = {Sonocatalytic hydrogen/hole-combined therapy for anti-biofilm and infected diabetic wound healing.}, journal = {National science review}, volume = {10}, number = {5}, pages = {nwad063}, pmid = {37056424}, issn = {2053-714X}, abstract = {It is a great challenge to effectively eradicate biofilm and cure biofilm-infected diseases because dense extracellular polymeric substance matrix prevents routine antibacterial agents from penetrating into biofilm. H2 is an emerging energy-regulating molecule possessing both high biosafety and high tissue permeability. In this work, we propose a concept of sonocatalytic hydrogen/hole-combined 'inside/outside-cooperation' anti-biofilm for promoting bacteria-infected diabetic wound healing based on two-dimensional piezoelectric nanomaterials. Proof-of-concept experiments using C3N4 nanosheets as a representative piezoelectric catalyst with wide band gap and high biosafety have verified that sonocatalytically generated H2 and holes rapidly penetrate into biofilm to inhibit bacterial energy metabolism and oxidatively deprive polysaccharides/NADH in biofilm to destroy the bacterial membrane/electron transport chain, respectively, inside/outside-cooperatively eradicating biofilm. A bacteria-infected diabetic wound model is used to confirm the excellent in vivo antibacterial performance of sonocatalytic hydrogen/hole-combined therapy, remarkably improving bacteria-infected diabetic wound healing. The proposed strategy of sonocatalytic hole/hydrogen-combined 'inside/outside-cooperation' will make a highway for treatment of deep-seated biofilm infection.}, }
@article {pmid37055625, year = {2023}, author = {Bezerra, FM and Rocchetti, TT and Lima, SL and Yu, MCZ and da Matta, DA and Höfling-Lima, AL and Melo, ASA and de Oliveira, LA}, title = {Candida species causing fungal keratitis: molecular identification, antifungal susceptibility, biofilm formation, and clinical aspects.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {37055625}, issn = {1678-4405}, abstract = {The study aimed to evaluate the clinical aspects, molecular identification, biofilm formation, and antifungal susceptibility profile of Candida species isolated from fungal keratitis. Thirteen Candida isolates from 13 patients diagnosed with Candida keratitis were retrieved and grown in pure culture. Species identification was performed by micromorphology analysis and ITS-rDNA sequencing. The broth microdilution method tested the minimum inhibitory concentration (MIC) of four antifungal drugs (fluconazole, amphotericin B, voriconazole, and anidulafungin). The biofilms were cultured and incubated with antifungal drugs for 24 h. The XTT reduction assay measured the biofilm activity. Biofilm MICs were calculated based on a 50% reduction in metabolic activity compared with the activity of the drug-free control. Among isolates, two were C. albicans, 10 were C. parapsilosis (sensu stricto), and one was C. orthopsilosis. All isolates were classified as susceptible or intermediate to all four antifungal drugs. Four isolates were very low biofilm producers (30%). Nine isolates were biofilm producers, and all biofilm samples were unsusceptible to all drugs tested. Previous ocular surgery was the most common underlying condition for fungal keratitis (84.6%), and C. parapsilosis was the most frequent Candida species (76.9%). Four patients (30.7%) needed keratoplasty, whereas two (15.3%) required evisceration. The biofilm formation ability of Candida isolates decreased antifungal susceptibility compared with planktonic cells. Despite in vitro antifungal susceptibility, almost half of the patients were unresponsive to clinical treatment and needed surgery.}, }
@article {pmid37055614, year = {2023}, author = {Wang, T and Shen, P and He, Y and Zhang, Y and Liu, J}, title = {Spatial transcriptome uncovers rich coordination of metabolism in E. coli K12 biofilm.}, journal = {Nature chemical biology}, volume = {}, number = {}, pages = {}, pmid = {37055614}, issn = {1552-4469}, abstract = {Microbial communities often display region-specific properties, which give rise to complex interactions and emergent behaviors that are critical to the homeostasis and stress response of the communities. However, systems-level understanding of these properties still remains elusive. In this study, we established RAINBOW-seq and profiled the transcriptome of Escherichia coli biofilm communities with high spatial resolution and high gene coverage. We uncovered three modes of community-level coordination, including cross-regional resource allocation, local cycling and feedback signaling, which were mediated by strengthened transmembrane transport and spatially specific activation of metabolism. As a consequence of such coordination, the nutrient-limited region of the community maintained an unexpectedly high level of metabolism, enabling it to express many signaling genes and functionally unknown genes with potential sociality functions. Our work provides an extended understanding of the metabolic interplay in biofilms and presents a new approach of investigating complex interactions in bacterial communities on the systems level.}, }
@article {pmid37051725, year = {2023}, author = {Sanders, MK and Duarte, S and Ayoub, HM and Scully, AC and Vinson, LA and Gregory, RL}, title = {Effect of titanium dioxide on Streptococcus mutans biofilm.}, journal = {Journal of applied biomaterials &amp; functional materials}, volume = {21}, number = {}, pages = {22808000221131892}, doi = {10.1177/22808000221131892}, pmid = {37051725}, issn = {2280-8000}, mesh = {Humans ; Streptococcus mutans ; Reactive Oxygen Species/metabolism ; *Metal Nanoparticles ; Silver/pharmacology ; *Dental Caries ; Biofilms ; }, abstract = {BACKGROUND: Streptococcus mutans (S. mutans) participates in the dental caries process. Titanium dioxide (TiO2) nanoparticles produce reactive oxygen species capable of disrupting bacterial DNA synthesis by creating pores in cell walls and membranes.<br><br>OBJECTIVE: The objective of this study was to determine the effect of TiO2 on the disruption of S. mutans biofilm.<br><br>METHODS: This study was conducted in four phases involving a TiO2-containing toothbrush and TiO2 nanoparticles. Each phase was completed using 24 h established S. mutans biofilm growth. Phase one data was collected through a bacterial plating study, assessing biofilm viability. Biofilm mass was evaluated in phase two of the study by measuring S. mutans biofilm grown on microtiter plates following crystal violet staining. The third phase of the study involved a generalized oxygen radical assay to determine the relative amount of oxygen radicals released intracellularly. Phase four of the study included the measurement of insoluble glucan/extracellular polysaccharide (EPS) synthesis using a phenol-sulfuric acid assay.<br><br>RESULTS: Both exposure time and time intervals had a significant effect on bacterial viability counts (p = 0.0323 and p = 0.0014, respectively). Bacterial counts after 6 min of exposure were significantly lower than after 2 min (p = 0.034), compared to the no treatment control (p = 0.0056). As exposure time increased, the amount of remaining biofilm mass was statistically lower than the no treatment control. Exposure time had a significant effect on oxygen radical production. Both the 30 and 100 nm TiO2 nanoparticles had a significant effect on bacterial mass. The silver nanoparticles and the 30 and 100 nm TiO2 nanoparticles significantly inhibited EPS production.<br><br>CONCLUSION: The TiO2-containing toothbrush kills, disrupts, and produces oxygen radicals that disrupt established S. mutans biofilm. TiO2 and silver nanoparticles inhibit EPS production and reduce biofilm mass. The addition of TiO2 to dental products may be effective in reducing cariogenic dental biofilm.}, }
@article {pmid37051555, year = {2022}, author = {Larijani, M and Zareshahrabadi, Z and Alhavaz, A and Hajipour, R and Ranjbaran, A and Giti, R and Soltankarimi, V and Zomorodian, K}, title = {Evaluation of Candida albicans biofilm formation on conventional and computer-aided-design/computer-aided manufacturing (CAD/CAM) denture base materials.}, journal = {Current medical mycology}, volume = {8}, number = {3}, pages = {23-29}, pmid = {37051555}, issn = {2423-3439}, abstract = {BACKGROUND AND PURPOSE: The human mouth mucosal surface is colonized by indigenous microflora, which normally maintains an ecological balance among different species. However, certain environmental or biological factors may disrupt this balance, leading to microbial diseases. Candida albicans biofilms are formed on indwelling medical devices and have an association with both oral and invasive candidiasis. This study aimed to compare the amount of adherent C. albicans and the biofilm formed on different denture base materials. The adhesion of C. albicans to denture base materials is widely recognized as the main reason for the development of denture stomatitis.<br><br>MATERIALS AND METHODS: In total, 56 polymethyl methacrylate (PMMA) acrylic resin disc-shaped samples were divided into four groups as follows: 1) chemically polymerized PMMA, 2) heat-polymerized PMMA, 3) computer-aided design and computer-aided manufacturing (CAD/CAM) PMMA in high polish, and 4) CAD/CAM resins in glazed form. The adherent cells and formation of C. albicans strains (562, 1905, 1912, and 1949) biofilm were measured by the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) method and use of a microplate reader. Moreover, morphological alterations of C. albicans cells were investigated using scanning electron microscopy (SEM).<br><br>RESULTS: The biofilm formation was significantly lower on CAD/CAM acrylic resins, compared to conventional denture base materials. The obtained results were confirmed by the SEM images of C. albicans biofilms. CAD/CAM PMMA-based polymers may be preferable to inhibit C. albicans biofilm formation and reduce Candida-associated denture stomatitis in long-term use.<br><br>CONCLUSION: Based on the findings, the CAD/CAM technique can be used as an efficient technique for denture fabrication as it inhibits microbial accumulation, and consequently, microbial biofilm.}, }
@article {pmid37050896, year = {2023}, author = {Wang, Y and Zhang, L and Yuan, X and Wang, D}, title = {Treatment with paeoniflorin increases lifespan of Pseudomonas aeruginosa infected Caenorhabditis elegans by inhibiting bacterial accumulation in intestinal lumen and biofilm formation.}, journal = {Frontiers in pharmacology}, volume = {14}, number = {}, pages = {1114219}, pmid = {37050896}, issn = {1663-9812}, abstract = {Paeoniflorin is one of the important components in Paeoniaceae plants. In this study, we used Caenorhabditis elegans as a model host and Pseudomonas aeruginosa as a bacterial pathogen to investigate the possible role of paeoniflorin treatment against P. aeruginosa infection in the host and the underlying mechanisms. Posttreatment with 1.25-10 mg/L paeoniflorin could significantly increase the lifespan of P. aeruginosa infected nematodes. After the infection, the P. aeruginosa colony-forming unit (CFU) and P. aeruginosa accumulation in intestinal lumen were also obviously reduced by 1.25-10 mg/L paeoniflorin treatment. The beneficial effects of paeoniflorin treatment in increasing lifespan in P. aeruginosa infected nematodes and in reducing P. aeruginosa accumulation in intestinal lumen could be inhibited by RNAi of pmk-1, egl-1, and bar-1. In addition, paeoniflorin treatment suppressed the inhibition in expressions of pmk-1, egl-1, and bar-1 caused by P. aeruginosa infection in nematodes, suggesting that paeoniflorin could increase lifespan of P. aeruginosa infected nematode by activating PMK-1, EGL-1, and BAR-1. Moreover, although treatment with 1.25-10 mg/L paeoniflorin did not show obvious anti-P. aeruginosa activity, the P. aeruginosa biofilm formation and expressions of related virulence genes (pelA, pelB, phzA, lasB, lasR, rhlA, and rhlC) were significantly inhibited by paeoniflorin treatment. Treatment with 1.25-10 mg/L paeoniflorin could further decrease the levels of related virulence factors of pyocyanin, elastase, and rhamnolipid. In addition, 2.5-10 mg/L paeoniflorin treatment could inhibit the swimming, swarming, and twitching motility of P. aeruginosa, and treatment with 2.5-10 mg/L paeoniflorin reduced the cyclic-di-GMP (c-di-GMP) level. Therefore, paeoniflorin treatment has the potential to extend lifespan of P. aeruginosa infected hosts by reducing bacterial accumulation in intestinal lumen and inhibiting bacterial biofilm formation.}, }
@article {pmid37050135, year = {2023}, author = {Fontana, R and Caproni, A and Sicurella, M and Manfredini, S and Baldisserotto, A and Marconi, P}, title = {Effects of Flavonoids and Phenols from Moringa oleifera Leaf Extracts on Biofilm Processes in Xanthomonas campestris pv. campestris.}, journal = {Plants (Basel, Switzerland)}, volume = {12}, number = {7}, pages = {}, pmid = {37050135}, issn = {2223-7747}, abstract = {Xanthomonas campestris pv. campestris is the causal agent of black rot in crucifers, a plant disease with significant economic impact. Xanthomonadaceae is a large family of Gram-negative bacteria that cause symptoms by blocking water flow in plants by invading the xylem. To accomplish this, the main mechanism the bacteria use to adapt to environmental changes and colonize tissues is biofilm formation. In recent years, growing interest in natural antimicrobial compounds has led to the study of different phytocomplexes derived from plants. In this work, Moringa oleifera was selected, as its leaves are rich in phenols, essential oils, and vitamins that exert antibacterial activity. X. campestris pv. campestris biofilm, one of its major virulence factors, was studied. Biofilm formation and removal were analyzed on abiotic and biotic surfaces with and without M. oleifera leaf extracts. The data from the analysis show that Moringa oleifera leaf extracts and single phenols were able to inhibit biofilm growth on abiotic surfaces, but the activity of the whole phytocomplex was significantly higher compared to that of individual phenols. The effect of Moringa oleifera extracts on cabbage leaves in vivo was also found to be very important, as scanning electron microscopy showed that treatment with the extracts led to clear unblocking of the xylem, implying many advantages for use in black rot control.}, }
@article {pmid37049901, year = {2023}, author = {Yu, M and Xin, J and Liu, Y and Chen, Y and Zhao, H and Li, Y and Hou, Y and Jia, M and Wang, B and Li, M}, title = {Pharmacological Characters and Toxicity Evaluation of Coumarin Derivative LP4C as Lead Compound against Biofilm Formation of Pseudomonas aeruginosa.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {7}, pages = {}, pmid = {37049901}, issn = {1420-3049}, mesh = {Animals ; Mice ; Anti-Bacterial Agents/pharmacology/metabolism ; Pseudomonas aeruginosa ; Biofilms ; *Anti-Infective Agents/pharmacology ; *Pseudomonas Infections/metabolism ; Microbial Sensitivity Tests ; }, abstract = {Pseudomonas aeruginosa-induced biofilm infection is difficult to treat and poses a significant threat to public health. Our previous study found a new coumarin derivative LP4C which exerted potent in vitro and in vivo anti-biofilm activity against Pseudomonas aeruginosa; however, the underlying molecular mechanism and drug-likeness of LP4C is unclear. In this study, we confirmed that LP4C could inhibit the biofilm in dose-dependent manner without bactericidal activity. The transcriptomic profiling and RT-PCR result revealed that bacterial pyrimidine mediated the inhibitory activity of LP4C. The cell viability was not affected in LP4C treatment groups with the concentration under 200 μg/mL, and no death or toxicity sign was observed in mice treated by 20, 40 and 80 mg/kg LP4C during the three-week test period. Ames test presented that LP4C had no effect on the bacterial reverse mutation. In additional, pharmacokinetic results showed that LP4C was likely to have the orally bioavailable properties. Our data indicate that LP4C is a possible lead compound for the development of new anti-biofilm infection agents against Pseudomonas aeruginosa.}, }
@article {pmid37049615, year = {2023}, author = {Rizzo, G and Pineda Chavez, SE and Vandenkoornhuyse, E and Cárdenas Rincón, CL and Cento, V and Garlatti, V and Wozny, M and Sammarco, G and Di Claudio, A and Meanti, L and Elangovan, S and Romano, A and Roda, G and Loy, L and Dal Buono, A and Gabbiadini, R and Lovisa, S and Rusconi, R and Repici, A and Armuzzi, A and Vetrano, S}, title = {Pomegranate Extract Affects Gut Biofilm Forming Bacteria and Promotes Intestinal Mucosal Healing Regulating the Crosstalk between Epithelial Cells and Intestinal Fibroblasts.}, journal = {Nutrients}, volume = {15}, number = {7}, pages = {}, doi = {10.3390/nu15071771}, pmid = {37049615}, issn = {2072-6643}, abstract = {Background: Pomegranate (Punica granatum) can be used to prepare a bioactive extract exerting anti-inflammatory activities. Clinical studies demonstrated an improvement in clinical response in inflammatory bowel disease (IBD) patients when pomegranate extract (PG) was taken as a complement to standard medications. However, the molecular mechanisms underlying its beneficial effects are still scarcely investigated. This study investigates the effect of PG on bacterial biofilm formation and the promotion of mucosal wound healing. Methods: The acute colitis model was induced in C57BL/6N mice by 3% dextran sodium sulfate administration in drinking water for 5 days. During the recovery phase of colitis, mice received saline or PG (200 mg/kg body weight) by oral gavage for 11 days. Colitis was scored daily by evaluating body weight loss, bleeding, and stool consistency. In vivo intestinal permeability was evaluated by fluorescein isothiocyanate-conjugated dextran assay, bacterial translocation was assessed by fluorescence in situ hybridization on tissues, whereas epithelial and mucus integrity were monitored by immunostaining for JAM-A and MUC-2 markers. Bacterial biofilm formation was assessed using microfluidic devices for 24 or 48 h. Primary fibroblasts were isolated from healthy and inflamed areas of 8 IBD patients, and Caco-2 cells were stimulated with or without PG (5 μg/mL). Inflammatory mediators were measured at the mRNA and protein level by RT-PCR, WB, or Bio-plex multiplex immunoassay, respectively. Results: In vivo, PG boosted the recovery phase of colitis, promoting a complete restoration of the intestinal barrier with the regeneration of the mucus layer, as also demonstrated by the absence of bacterial spread into the mucosa and the enrichment of crypt-associated fibroblasts. Microfluidic experiments did not highlight a specific effect of PG on Enterobacterales biofilm formation, even though Citrobacter freundii biofilm was slightly impaired in the presence of PG. In vitro, inflamed fibroblasts responded to PG by downregulating the release of metalloproteinases, IL-6, and IL-8 and upregulating the levels of HGF. Caco-2 cells cultured in a medium supplemented with PG increased the expression of SOX-9 and CD44, whereas in the presence of HGF or plated with a fibroblast-conditioned medium, they displayed a decrease in SOX-9 and CD44 expression and an increase in AXIN2, a negative regulator of Wnt signaling. Conclusions: These data provide new insight into the manifold effects of PG on promoting mucosal homeostasis in IBD by affecting pathogen biofilm formation and favoring the regeneration of the intestinal barrier through the regulation of the crosstalk between epithelial and stromal cells.}, }
@article {pmid37048337, year = {2023}, author = {Li, J and Mu, G and Tuo, Y}, title = {Phenotypic Traits and Probiotic Functions of Lactiplantibacillus plantarum Y42 in Planktonic and Biofilm Forms.}, journal = {Foods (Basel, Switzerland)}, volume = {12}, number = {7}, pages = {}, doi = {10.3390/foods12071516}, pmid = {37048337}, issn = {2304-8158}, abstract = {Bacteria in planktonic and biofilm forms exhibit different phenotypic properties. In this study, the phenotypic traits and probiotic functions of Lactiplantibacillus plantarum Y42 in planktonic and biofilm forms were assessed. After 36 h of static culture, scanning electron microscopy and confocal laser scanning microscopy showed that the L. plantarum Y42 bacterial cells contained interconnected adhesive matter on the surface, forming a ~18 μm layer of dense biofilms. The surface properties of L. plantarum Y42 in biofilm form, including autoaggregation ability, hydrophobicity, acid-base charge, and adhesiveness, were all higher than those in the planktonic form. Biofilm L. plantarum Y42 showed a higher tolerance to adverse environmental conditions and a higher survival rate, enzymatic activity, and integrity after vacuum lyophilization. And biofilm L. plantarum Y42 had higher adhesion to human enterocyte HT-29 cell monolayers, inhibited the expressions of proinflammatory factors IL-6 and TNF-α, and promoted the expressions of the anti-inflammatory factor IL-10 and barrier proteins Claudin-1 and Occludin. In addition, L. plantarum Y42 in biofilm form can inhibit the adhesion and invasion of Listeria monocytogenes ATCC 19115 to HT-29 cell monolayers and is more effective in relieving the inflammatory reactions and injuries of HT-29 cells caused by L. monocytogenes ATCC 19115. In conclusion, L. plantarum Y42 in biofilm form exhibited better probiotic functions compared to that in planktonic form. This indicated that L. plantarum Y42 can form biofilms to enhance its probiotic functions, which provided a theoretical basis for better development and utilization of L. plantarum Y42.}, }
@article {pmid37048183, year = {2023}, author = {He, J and Gao, X and Huang, H and Hao, J}, title = {Proposal and Verification of the Theory of Layer-by-Layer Elimination of Biofilm in Listeria monocytogenes.}, journal = {Foods (Basel, Switzerland)}, volume = {12}, number = {7}, pages = {}, doi = {10.3390/foods12071361}, pmid = {37048183}, issn = {2304-8158}, abstract = {Biofilms are microbial communities that represent a high abundance of microbial life forms on Earth. Within biofilms, structural changes during clearance processes occur in three spatial and temporal dimensions; therefore, microscopy and quantitative image analysis are essential in elucidating their function. Here, we present confocal laser scanning microscopy (CLSM) in conjunction with ISA-2 software analysis for the automated and high-throughput quantification, analysis, and visualisation of biofilm interiors and overall biofilm properties in three spatial and temporal dimensions. This paper discusses the removal process of Listeria monocytogenes (LM) biofilms using slightly acidic electrolytic water, non-electrolytic hypochlorite water, and alternating the use of strongly acidic and strongly alkaline electrolytic water. The results show that the biofilm gradually thins and gutters from the initial viscous dense and thick morphology under the action of either biocide. This process is consistent with first-level kinetics. After CLSM filming to observe the biofilm structure, analysis software was used to process and quantify the biovolume, average biofilm thickness, biofilm roughness and other indicators; fluorescence enzyme markers were used to verify the remaining amount of extracellular nucleic acid. In this study, we proposed and validated the theory of layer-by-layer elimination of LM biofilm.}, }
@article {pmid37047667, year = {2023}, author = {Pezzotti, G and Ofuji, S and Imamura, H and Adachi, T and Yamamoto, T and Kanamura, N and Ohgitani, E and Marin, E and Zhu, W and Mazda, O and Togo, A and Kimura, S and Iwata, T and Shiba, H and Ouhara, K and Aoki, T and Kawai, T}, title = {In Situ Raman Analysis of Biofilm Exopolysaccharides Formed in Streptococcus mutans and Streptococcus sanguinis Commensal Cultures.}, journal = {International journal of molecular sciences}, volume = {24}, number = {7}, pages = {}, doi = {10.3390/ijms24076694}, pmid = {37047667}, issn = {1422-0067}, abstract = {This study probed in vitro the mechanisms of competition/coexistence between Streptococcus sanguinis (known for being correlated with health in the oral cavity) and Streptococcus mutans (responsible for aciduric oral environment and formation of caries) by means of quantitative Raman spectroscopy and imaging. In situ Raman assessments of live bacterial culture/coculture focusing on biofilm exopolysaccharides supported the hypothesis that both species engaged in antagonistic interactions. Experiments of simultaneous colonization always resulted in coexistence, but they also revealed fundamental alterations of the biofilm with respect to their water-insoluble glucan structure. Raman spectra (collected at fixed time but different bacterial ratios) showed clear changes in chemical bonds in glucans, which pointed to an action by Streptococcus sanguinis to discontinue the impermeability of the biofilm constructed by Streptococcus mutans. The concurrent effects of glycosidic bond cleavage in water-insoluble α - 1,3-glucan and oxidation at various sites in glucans' molecular chains supported the hypothesis that secretion of oxygen radicals was the main "chemical weapon" used by Streptococcus sanguinis in coculture.}, }
@article {pmid37047479, year = {2023}, author = {Chen, T and Wang, S and Niu, H and Yang, G and Wang, S and Wang, Y and Zhou, C and Yu, B and Yang, P and Sun, W and Liu, D and Ying, H and Chen, Y}, title = {Biofilm-Based Biocatalysis for Galactooligosaccharides Production by the Surface Display of β-Galactosidase in Pichia pastoris.}, journal = {International journal of molecular sciences}, volume = {24}, number = {7}, pages = {}, doi = {10.3390/ijms24076507}, pmid = {37047479}, issn = {1422-0067}, abstract = {Galactooligosaccharides (GOS) are one of the most important functional oligosaccharide prebiotics. The surface display of enzymes was considered one of the most excellent strategies to obtain these products. However, a rough industrial environment would affect the biocatalytic process. The catalytic process could be efficiently improved using biofilm-based fermentation with high resistance and activity. Therefore, the combination of the surface display of β-galactosidase and biofilm formation in Pichia pastoris was constructed. The results showed that the catalytic conversion rate of GOS was up to 50.3% with the maximum enzyme activity of 5125 U/g by screening the anchorin, and the number of the continuous catalysis batches was up to 23 times. Thus, surface display based on biofilm-immobilized fermentation integrated catalysis and growth was a co-culture system, such that a dynamic equilibrium in the consolidated integrative process was achieved. This study provides the basis for developing biofilm-based surface display methods in P. pastoris during biochemical production processes.}, }
@article {pmid37047147, year = {2023}, author = {Wolfson, G and Sionov, RV and Smoum, R and Korem, M and Polacheck, I and Steinberg, D}, title = {Anti-Bacterial and Anti-Biofilm Activities of Anandamide against the Cariogenic Streptococcus mutans.}, journal = {International journal of molecular sciences}, volume = {24}, number = {7}, pages = {}, doi = {10.3390/ijms24076177}, pmid = {37047147}, issn = {1422-0067}, abstract = {Streptococcus mutans is a cariogenic bacterium in the oral cavity involved in plaque formation and dental caries. The endocannabinoid anandamide (AEA), a naturally occurring bioactive lipid, has been shown to have anti-bacterial and anti-biofilm activities against Staphylococcus aureus. We aimed here to study its effects on S. mutans viability, biofilm formation and extracellular polysaccharide substance (EPS) production. S. mutans were cultivated in the absence or presence of various concentrations of AEA, and the planktonic growth was followed by changes in optical density (OD) and colony-forming units (CFU). The resulting biofilms were examined by MTT metabolic assay, Crystal Violet (CV) staining, spinning disk confocal microscopy (SDCM) and high-resolution scanning electron microscopy (HR-SEM). The EPS production was determined by Congo Red and fluorescent dextran staining. Membrane potential and membrane permeability were determined by diethyloxacarbocyanine iodide (DiOC2(3)) and SYTO 9/propidium iodide (PI) staining, respectively, using flow cytometry. We observed that AEA was bactericidal to S. mutans at 12.5 µg/mL and prevented biofilm formation at the same concentration. AEA reduced the biofilm thickness and biomass with concomitant reduction in total EPS production, although there was a net increase in EPS per bacterium. Preformed biofilms were significantly affected at 50 µg/mL AEA. We further show that AEA increased the membrane permeability and induced membrane hyperpolarization of these bacteria. AEA caused S. mutans to become elongated at the minimum inhibitory concentration (MIC). Gene expression studies showed a significant increase in the cell division gene ftsZ. The concentrations of AEA needed for the anti-bacterial effects were below the cytotoxic concentration for normal Vero epithelial cells. Altogether, our data show that AEA has anti-bacterial and anti-biofilm activities against S. mutans and may have a potential role in preventing biofilms as a therapeutic measure.}, }
@article {pmid37044235, year = {2023}, author = {Delik, E and Eroğlu, B and Çolak, &#xc7;Y and Özçelik, AT and Tefon Öztürk, BE}, title = {Alterations of Growth, Biofilm-Forming, and Gene Expression of Bordetella pertussis by Antibiotics at Sub-Minimal Inhibitory Concentrations.}, journal = {Research in microbiology}, volume = {}, number = {}, pages = {104058}, doi = {10.1016/j.resmic.2023.104058}, pmid = {37044235}, issn = {1769-7123}, abstract = {Bordetella pertussis is the primary agent of the acute respiratory disease pertussis. It has been reported that the disease has recently become more common, especially in adults and adolescents, and adaptation of the pathogen is thought to have an important influence on the recurrence of the disease. This study aims to determine the effect of erythromycin, azithromycin, and trimethoprim-sulfamethoxazole used in the treatment of pertussis on the virulence gene expressions (prn, ptxS1, fhaB), biofilm-forming and growth of B. pertussis. In this study, the minimal inhibitory concentration (MIC) values of azithromycin and erythromycin in B. pertussis local strain Saadet were determined to be 0.09 μg/mL and 0.3 μg/mL, respectively. However, the Tohama-I and Saadet strains were resistant to trimethoprim-sulfamethoxazole (MIC>32 μg/mL). The biofilm-forming of the Saadet strain decreased with the increase in antibiotic doses. It was observed that 1/32MIC erythromycin and 1/32MIC azithromycin upregulated the expression of fhaB in Tohama-I, whereas the expression of ptxS1 and prn significantly decreased in sub-MICs of erythromycin. In the Saadet strain, only ptxS1 was highly expressed at 1/16MIC azithromycin and erythromycin (p>0.05). This is the first study to investigate the effect of sub-MIC antibiotics on the expression of virulence genes and biofilm-forming of B. pertussis.}, }
@article {pmid37043980, year = {2023}, author = {Tan, Y and Lin, Q and Yao, J and Zhang, G and Peng, X and Tian, J}, title = {In vitro outcomes of quercetin on Candida albicans planktonic and biofilm cells and in vivo effects on vulvovaginal candidiasis. Evidences of its mechanisms of action.}, journal = {Phytomedicine : international journal of phytotherapy and phytopharmacology}, volume = {114}, number = {}, pages = {154800}, doi = {10.1016/j.phymed.2023.154800}, pmid = {37043980}, issn = {1618-095X}, abstract = {BACKGROUND AND PURPOSE: Candida albicans is a fungus that produces common fungal infection in humans, including vulvovaginal candidiasis (VVC). While quercetin (QC) has potential antifungal activities against C. albicans, studies on the in vivo anti-VVC activity of QC are limited. This study evaluated the antifungal capacity of QC against cultured C. albicans strain SC5314 or in C. albicans-infected mice.<br><br>METHODS: Microdilution and XTT reduction assay were used to determine the minimum inhibitory concentration (MIC) and biofilm formation of QC on C. albicans, respectively. Immunofluorescence was performed to detect the anti-invasive capacity of QC upon co-culturing C. albicans with VK2/E6E7 cells. The potential anti-VVC effects of QC were assessed in C. albicans-infected mice with VVC. Further, inflammatory cytokine levels were determined using ELISA. PAS and Papanicolaou staining were used to detect C. albicans cells and polymorphonuclear leukocytes (PMNs) in vaginal tissues. Western blotting and immunohistochemistry were performed to measure the expression of MAPK, ERK, JUN, and P38.<br><br>RESULTS: MIC and minimal fungicidal concentration (MFC) of QC for C. albicans were 128 &#x3bc;M and > 512 &#x3bc;M, respectively. QC concentration lower than 128 &#x3bc;M (32-128 &#x3bc;M) could not inhibit C. albicans. QC (16 &#x3bc;M) notably inhibited C. albicans biofilm formation and suppressed the adhesion and invasion of C. albicans to VK2/E6E7 cells. In addition, the pharmacokinetic parameters of orally administered QC in mice showed rapid absorption (approximately 1 h) and slow elimination (approximately 6 h). Oral QC showed an effective protective function against C. albicans infection with no toxic effects a in mouse VVC model. QC significantly reduced IL-1&#x3b1;, TNF-&#x3b1;, IL-22 and IL-23 levels in vaginal lavage solution, inhibited invasive C. albicans and PMN infiltration in vaginal tissue, and effectively protected the integrity of vaginal mucosa.<br><br>CONCLUSIONS: The present study showed that QC has rapid oral absorption, slow elimination, good viral distribution, and a lack of toxicity. QC not only inhibited biofilm formation, adhesion, and invasion of C. albicans in vitro, but also ameliorated C. albicans-induced inflammation and protected the integrity of the vaginal mucosa in vivo, suggesting that QC has the potential for the treatment of candidiasis.}, }
@article {pmid37042006, year = {2023}, author = {Edris, SN and Hamad, A and Awad, DAB and Sabeq, II}, title = {Prevalence, antibiotic resistance patterns, and biofilm formation ability of Enterobacterales recovered from food of animal origin in Egypt.}, journal = {Veterinary world}, volume = {16}, number = {2}, pages = {403-413}, pmid = {37042006}, issn = {0972-8988}, abstract = {BACKGROUND AND AIM: The majority of animal-derived food safety studies have focused on foodborne zoonotic agents; however, members of the opportunistic Enterobacteriaceae (Ops) family are increasingly implicated in foodborne and public health crises due to their robust evolution of acquiring antimicrobial resistance and biofilms, consequently require thorough characterization, particularly in the Egyptian food sector. Therefore, this study aimed to determine the distribution and prevalence of Enterobacteriaceae family members in animal-derived foods, as well as their resistance to important antimicrobials and biofilm-forming potential.<br><br>MATERIALS AND METHODS: A total of 274 beef, rabbit meat, chicken meat, egg, butter, and milk samples were investigated for the presence of Enterobacteriaceae. All isolated strains were first recognized using traditional microbiological techniques. Following that, matrix-assisted laser desorption ionization-time of flight mass spectrometry was used to validate the Enterobacteriaceae's identity. The isolated enterobacteria strains were tested on disk diffusion and crystal violet quantitative microtiter plates to determine their antibiotic resistance and capacity to form biofilms.<br><br>RESULTS: There have been thirty isolates of Enterobacteriaceae from seven different species and four genera. Out of the three food types, Pseudomonas aeruginosa had the highest prevalence rate (4.1%). With three species, Enterobacter genera had the second-highest prevalence (3.28%) across five different food categories. In four different food types, the Klebsiella genera had the second-highest distribution and third-highest incidence (2.55%). Almost all isolates, except three Proteus mirabilis, showed prominent levels of resistance, particularly to beta-lactam antibiotics. Except for two Enterobacter cloacae and three P. mirabilis isolates, all isolates were classified as multidrug-resistant (MDR) orextensively multidrug-resistant (XDR). The multiple antibiotic resistance index (MARI) of the majority of isolates dropped between 0.273 and 0.727. The highest MARI was conferred by Klebsiella pneumoniae, at 0.727. Overall, 83.33% of the isolates had strong biofilm capacity, while only 16.67% exhibited moderate capacity.<br><br>CONCLUSION: The MDR, XDR, and strong biofilm indicators confirmed in 83.33% of the currently tested Enterobacteriaceae from animal-derived foods suggest that, if not addressed, there may be rising risks to Egypt's economy and public health.}, }
@article {pmid37041833, year = {2023}, author = {Ibraheim, HK and Madhi, KS and Baqer, GK and Gharban, HAJ}, title = {Effectiveness of raw bacteriocin produced from lactic acid bacteria on biofilm of methicillin-resistant Staphylococcus aureus.}, journal = {Veterinary world}, volume = {16}, number = {3}, pages = {491-499}, pmid = {37041833}, issn = {0972-8988}, abstract = {BACKGROUND AND AIM: Probiotics are proven beneficial to health since they enhance immunity against dangerous pathogens and increase resistance to illness. Bacteriocin produced by lactic acid bacteria (LAB), demonstrates a broad inhibitory spectrum and therapeutic potential. This study aimed to isolate LAB-producing bacteriocin and investigate the effect of crude bacteriocin on biofilm from methicillin-resistant Staphylococcus aureus (MRSA).<br><br>MATERIALS AND METHODS: This study used randomly collected 80 white soft local cheeses (40 each from cows and sheep) from different supermarkets in Basrah Province. The obtained samples were cultured and the bacterial suspension of S. aureus was prepared at 1.5 &#xd7; 10[8] cells/mL. The crude bacteriocin extracted from LAB was obtained, and the tube was dried and inverted to detect the biofilm loss at the bottom.<br><br>RESULTS: There were 67 (83.75%) LAB isolates. Among 40 milk samples collected directly and indirectly, there were 36 (83.33%). Staphylococcus aureus isolates based on conventional bacteriological analysis and biochemical tests. Molecular testing was conducted to identify LAB and MRSA. Depending on genotypic results, the effect of white soft local cheese (cows and sheep) and the amplification results of the 16S rRNA gene were detected in 46 LAB isolates from white soft local cheese from cows and sheep. Based on the molecular identification of the mecA, results on Staphylococcus determined that only 2 of 36 isolates of S. aureus carried the mecA. Moreover, there were 26 (86.66%) isolates (MRSA) from samples of raw milk from local markets and subclinical mastitis in cows. The ability of LAB isolates was tested. The effects of bacteriocin production on preventing biofilm growth and formation were investigated. Results demonstrated that bacteriocin has high activity. Microtiter plates applied to investigate the ability of S. aureus to produce biofilms revealed that all isolates were either weak or moderate biofilm producers, with neither non-biofilm nor strong biofilm producers found among the tested isolates.<br><br>CONCLUSION: Lactic acid bacteria demonstrate a high ability to produce bacteriocin. Crude bacteriocin from LAB has a restrictive effect on biofilms produced by MRSA; thus, it can be used to reduce the pathogenicity of this bacterium.}, }
@article {pmid37041795, year = {2022}, author = {Asnaashari, M and Mehrabinia, P and Yadegari, Z and Hoseini, H and Sadafi, M and Shojaeian, S}, title = {Evaluation of Antibacterial Effects of Cold Atmospheric Plasma, Calcium Hydroxide, and Triple Antibiotic Paste on Enterococcus faecalis Biofilm in the Root Canal System: An In Vitro Study.}, journal = {Journal of lasers in medical sciences}, volume = {13}, number = {}, pages = {e50}, pmid = {37041795}, issn = {2008-9783}, abstract = {Introduction: One of the essential factors in successful endodontic therapy is the effective cleaning and disinfection of the root canal. This study aimed to determine the effect of cold plasma on infected root canals with Enterococcus faecalis and compare its antibacterial effect with the conventional medicaments in vitro. Methods: Sixty-tree single-root teeth were extracted. Canals were cleaned and shaped. Ten teeth were selected as the negative control randomly. The rest of the teeth were incubated at 37°C for 21 days to form E. faecalis biofilm. The specimens were divided into six groups; each group had 10 teeth. In group 1 (the positive control group of calcium hydroxide and triple antibiotic paste [TAP]), methylcellulose was placed in the root canal; in group 2, calcium hydroxide was placed in the root canal for 12 days; in group 3, 10 mg/mL of TAP was placed in the root canal for 12 days; in group 4, helium/oxygen plasma jet was used for 10 minutes. Group 5 was considered as a positive control of plasma, and group 6 was the negative control. After treatment, F4 Pro-Taper rotary file was used to collect root canal microbial biofilms. Bacterial suspensions were serially diluted, and the percentage of growth reduction for each group was obtained by dividing the logarithm of CFU/mL of each group by CFU/mL of the control of the same group. Results: The CFU/mL of TAP and plasma-treated samples was significantly lower than that of the control groups; however, there were no significant differences between the control group and the samples treated by calcium hydroxide. The most percentage of CFU reduction was in the TAP-treated group compared with plasma and calcium hydroxide-treated groups. Conclusion: The application of cold plasma effectively inhibited the growth of E. faecalis and reduced bacterial biofilm. Also, in the present study, 10 mg/mL of TAP caused the complete elimination of E. faecalis. Calcium hydroxide had the most negligible effect on E. faecalis biofilm elimination.}, }
@article {pmid37041658, year = {2023}, author = {}, title = {Correction to "Azospirillum baldaniorum Sp245 exploits Pseudomonas fluorescens A506 biofilm to overgrow in dual-species macrocolonies".}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.16383}, pmid = {37041658}, issn = {1462-2920}, }
@article {pmid37036347, year = {2023}, author = {Lewis, AM and Willard, DJ and H Manesh, MJ and Sivabalasarma, S and Albers, SV and Kelly, RM}, title = {Stay or Go: Sulfolobales Biofilm Dispersal Is Dependent on a Bifunctional VapB Antitoxin.}, journal = {mBio}, volume = {}, number = {}, pages = {e0005323}, doi = {10.1128/mbio.00053-23}, pmid = {37036347}, issn = {2150-7511}, abstract = {A type II VapB14 antitoxin regulates biofilm dispersal in the archaeal thermoacidophile Sulfolobus acidocaldarius through traditional toxin neutralization but also through noncanonical transcriptional regulation. Type II VapC toxins are ribonucleases that are neutralized by their proteinaceous cognate type II VapB antitoxin. VapB antitoxins have a flexible tail at their C terminus that covers the toxin's active site, neutralizing its activity. VapB antitoxins also have a DNA-binding domain at their N terminus that allows them to autorepress not only their own promoters but also distal targets. VapB14 antitoxin gene deletion in S. acidocaldarius stunted biofilm and planktonic growth and increased motility structures (archaella). Conversely, planktonic cells were devoid of archaella in the ΔvapC14 cognate toxin mutant. VapB14 is highly conserved at both the nucleotide and amino acid levels across the Sulfolobales, extremely unusual for type II antitoxins, which are typically acquired through horizontal gene transfer. Furthermore, homologs of VapB14 are found across the Crenarchaeota, in some Euryarchaeota, and even bacteria. S. acidocaldarius vapB14 and its homolog in the thermoacidophile Metallosphaera sedula (Msed_0871) were both upregulated in biofilm cells, supporting the role of the antitoxin in biofilm regulation. In several Sulfolobales species, including M. sedula, homologs of vapB14 and vapC14 are not colocalized. Strikingly, Sulfuracidifex tepidarius has an unpaired VapB14 homolog and lacks a cognate VapC14, illustrating the toxin-independent conservation of the VapB14 antitoxin. The findings here suggest that a stand-alone VapB-type antitoxin was the product of selective evolutionary pressure to influence biofilm formation in these archaea, a vital microbial community behavior. IMPORTANCE Biofilms allow microbes to resist a multitude of stresses and stay proximate to vital nutrients. The mechanisms of entering and leaving a biofilm are highly regulated to ensure microbial survival, but are not yet well described in archaea. Here, a VapBC type II toxin-antitoxin system in the thermoacidophilic archaeon Sulfolobus acidocaldarius was shown to control biofilm dispersal through a multifaceted regulation of the archaeal motility structure, the archaellum. The VapC14 toxin degrades an RNA that causes an increase in archaella and swimming. The VapB14 antitoxin decreases archaella and biofilm dispersal by binding the VapC14 toxin and neutralizing its activity, while also repressing the archaellum genes. VapB14-like antitoxins are highly conserved across the Sulfolobales and respond similarly to biofilm growth. In fact, VapB14-like antitoxins are also found in other archaea, and even in bacteria, indicating an evolutionary pressure to maintain this protein and its role in biofilm formation.}, }
@article {pmid37035538, year = {2023}, author = {Bisso, BN and Makuété, AL and Tsopmene, JU and Dzoyem, JP}, title = {Biofilm Formation and Phospholipase and Proteinase Production in Cryptococcus neoformans Clinical Isolates and Susceptibility towards Some Bioactive Natural Products.}, journal = {TheScientificWorldJournal}, volume = {2023}, number = {}, pages = {6080489}, pmid = {37035538}, issn = {1537-744X}, mesh = {Humans ; Antifungal Agents/pharmacology ; *Cryptococcus neoformans ; Peptide Hydrolases ; Thymol ; Phospholipases ; *Cryptococcosis/drug therapy/epidemiology/microbiology ; Microbial Sensitivity Tests ; Virulence Factors ; Biofilms ; }, abstract = {BACKGROUND: Cryptococcosis is one of the most common fungal infections in immunocompromised patients, which is caused by Cryptococcus neoformans. However, relatively little is known about the virulence factors of C. neoformans and the incidence of antifungal drug resistance in C. neoformans is rapidly increasing. This study was undertaken to investigate the virulence factors in C. neoformans, thymol, curcumin, piperine, gallic acid, eugenol, and plumbagin for their potential antimicrobial activity against C. neoformans.<br><br>METHODS: The production of phospholipase and proteinase was detected using standard methods. Biofilm formation was determined using the microtiter plate method. The broth microdilution method was used to determine the antifungal activity. The antibiofilm activity was assessed using the safranin staining method.<br><br>RESULTS: All isolates of C. neoformans produced biofilms with optical density values ranging from 0.16 to 0.89. A majority of C. neoformans isolates that were tested exhibited strong phospholipase (7/8) and proteinase (5/8) production. Plumbagin (with minimum inhibitory concentration values ranging from 4 to 16&#x2009;&#x3bc;g/mL) showed the highest antifungal activity followed by thymol (with minimum biofilm inhibitory concentration values ranging from 8 to 64&#x2009;&#x3bc;g/mL). In addition, plumbagin showed the highest antibiofilm activity with minimum biofilm inhibitory concentration and minimum biofilm eradication concentration values ranging from 4 to 16&#x2009;&#x3bc;g/mL and 32 to 256&#x2009;&#x3bc;g/mL, respectively.<br><br>CONCLUSION: Plumbagin, compared to other natural products studied, was the most efficient in terms of antifungal and antibiofilm activities. Hence, plumbagin could be used in combination with antifungals for the development of new anticryptococcal drugs.}, }
@article {pmid37034999, year = {2023}, author = {Xiong, Y and Liu, S and Zheng, J and Chen, J and Wen, Z and Deng, X and Bai, B and Li, D and Yu, Z and Han, S and Liu, X and Li, P}, title = {Cinacalcet exhibits rapid bactericidal and efficient anti-biofilm activities against multidrug-resistant Gram-positive pathogens.}, journal = {iScience}, volume = {26}, number = {4}, pages = {106378}, pmid = {37034999}, issn = {2589-0042}, abstract = {Infections caused by Gram-positive bacteria pose a serious threat to global public health. Drug resistance, dormant persister cells, and biofilm formation are the key challenges affecting the efficacy of antibiotics against Gram-positive bacterial infections. In this study, cinacalcet exhibited good inhibitory activity against multidrug-resistant Gram-positive bacteria, with minimum inhibitory concentrations (MICs) ranging from 3.13 μg/mL to 25 μg/mL. Cinacalcet displayed more rapid and stronger bactericidal activity against planktonic and persister cells of Staphylococcus aureus and Enterococcus faecalis compared with the antibiotics vancomycin or ampicillin, as well as potent inhibition and eradication of mature biofilms of methicillin-resistant S. aureus (MRSA) and linezolid-resistant E. faecalis (LRE). In addition, the robust antibacterial activity was demonstrated in vivo by a pneumonia infection model and a biofilm formation and deep-seated infection model. Collectively, these findings indicate that cinacalcet may be a promising new candidate antibiotic to combat infections caused by multidrug-resistant Gram-positive pathogens.}, }
@article {pmid37031894, year = {2023}, author = {Castelo-Branco, DSCM and de Aguiar, L and de Melo Guedes, GM and de Aquino Pereira-Neto, W and de Aguiar Cordeiro, R and Brilhante, RSN and Sidrim, JJC and Rocha, MFG}, title = {Standardization of in vitro dual-species biofilms of Staphylococcus pseudintermedius and Malassezia pachydermatis: A strategy to establish an ex vivo biofilm model.}, journal = {Journal of microbiological methods}, volume = {}, number = {}, pages = {106721}, doi = {10.1016/j.mimet.2023.106721}, pmid = {37031894}, issn = {1872-8359}, abstract = {Ex vivo experiments have been performed aiming at mimicking in vivo environments. The main aim of this research was to standardize in vitro dual-species biofilm formation by Staphylococcus pseudintermedius and Malassezia pachydermatis as a strategy to establish an ex vivo biofilm model. Initially, the in vitro formation of biofilms in co-culture was established, using YPD medium, inoculum turbidity of 0.5 on the McFarland scale and maturation periods of 96 h for M. pachydermatis and 48 h for S. pseudintermedius. Subsequently, biofilms were formed on porcine skin using the same conditions, under which a greater number of cells/ml was observed in in vitro dual-species than in in vitro mono-species biofilms. Furthermore, ex vivo biofilm images demonstrated the formation of a highly structured biofilm with the presence of cocci and yeasts surrounded by the matrix. Thus, these conditions optimized the growth of both microorganisms within biofilms in vitro and ex vivo.}, }
@article {pmid37031284, year = {2023}, author = {Vasconcelos, L and Aburjaile, F and Andrade, L and Cancio, AF and Seyffert, N and Aguiar, ERGR and Ristow, P}, title = {Genomic insights into the c-di-GMP signaling and biofilm development in the saprophytic spirochete Leptospira biflexa.}, journal = {Archives of microbiology}, volume = {205}, number = {5}, pages = {180}, pmid = {37031284}, issn = {1432-072X}, mesh = {Bacterial Proteins/genetics/metabolism ; Spirochaetales/metabolism ; *Escherichia coli Proteins/genetics ; Bacteria/metabolism ; *Leptospira/genetics/metabolism ; Genomics ; Biofilms ; Gene Expression Regulation, Bacterial ; }, abstract = {C-di-GMP is a bacterial second messenger with central role in biofilm formation. Spirochete bacteria from Leptospira genus present a wide diversity, with species of medical importance and environmental species, named as saprophytic. Leptospira form biofilms in the rat's reservoir kidneys and in the environment. Here, we performed genomic analyses to identify enzymatic and effector c-di-GMP proteins in the saprophytic biofilm-forming species Leptospira biflexa serovar Patoc. We identified 40 proteins through local alignments. Amongst them, 16 proteins are potentially functional diguanylate cyclases, phosphodiesterases, or hybrid proteins. We also identified nine effectors, including PilZ proteins. Enrichment analyses suggested that c-di-GMP interacts with cAMP signaling system, CsrA system, and flagella assembly regulation during biofilm development of L. biflexa. Finally, we identified eight proteins in the pathogen Leptospira interrogans serovar Copenhageni that share high similarity with L. biflexa c-di-GMP-related proteins. This work revealed proteins related to c-di-GMP turnover and cellular response in Leptospira and their potential roles during biofilm development.}, }
@article {pmid37030463, year = {2023}, author = {Bains, A and Sharma, P and Kaur, S and Yadav, R and Kumar, A and Sridhar, K and Chawla, P and Sharma, M}, title = {Gum arabic/guar gum stabilized Hydnocarpus wightiana oil nanohydrogel: Characterization, antimicrobial, anti-inflammatory, and anti-biofilm activities.}, journal = {International journal of biological macromolecules}, volume = {239}, number = {}, pages = {124341}, doi = {10.1016/j.ijbiomac.2023.124341}, pmid = {37030463}, issn = {1879-0003}, abstract = {Hydnocarpus wightiana oil has proven to inhibit the growth of pathogenic microorganisms; however, the raw form is highly susceptible to oxidation, and thus it becomes toxic when uptake is in high amounts. Therefore, to minimize the deterioration, we formulated Hydnocarpus wightiana oil-based nanohydrogel and studied its characteristics as well biological activity. The low energy-assisted hydrogel was formulated by including gelling agent, connective linker, and cross-linker and it resulted in internal micellar polymerization of the milky white emulsion. The oil showed the presence of octanoic acid, n-tetradecane, methyl 11-(2-cyclopenten-1-yl) undecanoate (methyl hydnocarpate), 13-(2-cyclopenten-1-yl) tridecanoic acid (methyl chaulmoograte), and 10,13-eicosadienoic acid. The amount of caffeic acid was 0.0636 mg/g, which was higher than the amount of gallic acid (0.0076 mg/g) in the samples. The formulated nanohydrogel showed an average droplet size of 103.6 nm with a surface charge of -17.6 mV. The minimal inhibitory bactericidal, and fungicidal concentrations of nanohydrogel against pathogenic bacteria and fungi were ranging from 0.78 to 1.56 μl/mL with 70.29-83.62 % antibiofilm activity. Also, nanohydrogel showed a significantly (p < 0.05) higher killing rate for Escherichia coli (7.89 log CFU/mL) than Staphylococcus aureus (7.81 log CFU/mL) with comparable anti-inflammatory activity than commercial standard (49.28-84.56 %). Therefore, it can be concluded that being hydrophobic, and having the capability of target-specific drug absorption as well as biocompatibility nanohydrogels can be utilized to cure various pathogenic microbial infections.}, }
@article {pmid37030196, year = {2023}, author = {Sanchez-Huerta, C and Medina, JS and Wang, C and Fortunato, L and Hong, PY}, title = {Understanding the role of sorption and biodegradation in the removal of organic micropollutants by membrane aerated biofilm reactor (MABR) with different biofilm thickness.}, journal = {Water research}, volume = {236}, number = {}, pages = {119935}, doi = {10.1016/j.watres.2023.119935}, pmid = {37030196}, issn = {1879-2448}, abstract = {The role of sorption and biodegradation in a membrane aerated biofilm reactor (MABR) were investigated for the removal of 10 organic micropollutants (OMPs) including endocrine disruptors and pharmaceutical active compounds. The influence of the biofilm thickness on the mechanisms of removal was analyzed via kinetic test at three different stages. At all biofilm stages, biodegradation was demonstrated to dominate the removal of selected OMPs. Higher OMPs rates of removal via biodegradation (Kbiol) were achieved when biofilm increased its thickness from (stage T1) 0.26 mm, to (stage T2) 0.58 mm and (stage T3) 1.03 mm. At stage T1 of biofilm, heterotrophs contribute predominantly to OMPs degradation. Hydrophilic compounds removal (i.e., acetaminophen) continue to be driven by heterotrophic bacteria at the next stages of biofilm thickness. However, for medium hydrophobic neutral and charged OMPs, the combined action of heterotrophic and enriched nitrifying activity at stages T2 and T3 enhanced the overall removal. A degradation pathway based on heterotrophic activity for acetaminophen and combined action of nitrifiers-heterotrophs for estrone was proposed based on identified metabolites. Although biodegradation dominated the removal of most OMPs, sorption was also observed to be essential in the removal of biologically recalcitrant and lipophilic compounds like triclosan. Furthermore, sorption capacity of apolar compound was enhanced as the biofilm thickness grew and increased in EPS protein fraction. Microbial analysis confirmed the higher abundance of nitrifying and denitrifying activity at stage T3 of biofilm, which not only facilitated near complete ammonium removal but also enhanced degradation of OMPs.}, }
@article {pmid37029837, year = {2023}, author = {Mirzaei, B and Ebrahimi, A and Keshavarzi, S and Hydarzadeh, S and Badmasti, F and Dadar, M and Moradi, N}, title = {Antibiotic Susceptibility, Biofilm-Forming Ability, and Prevalence of Extended-Spectrum Beta-Lactamase (ESBL)- and Biofilm-Associated Genes Among Klebsiella pneumoniae Isolates from Hospitalized Patients in Northwest of Iran.}, journal = {Current microbiology}, volume = {80}, number = {5}, pages = {175}, pmid = {37029837}, issn = {1432-0991}, abstract = {Klebsiella pneumoniae is an opportunistic bacterium, which is globally recognized for its high prevalence and antimicrobial resistance (AMR). Biofilm-forming capability, susceptibility testing, and phenotypic confirmatory test for extended-spectrum beta-lactamase (ESBL)-producing isolate recognition of 104 K. pneumoniae isolates were performed according to the Clinical Laboratory Standard Institute (CLSI) guidelines. The prevalence of ESBL-associated genes bla-VIM, bla-NDM, and bla-OXA-48, as well as biofilm-associated genes luxS, fimH1, wza, and mrkD, was determined by multiplex PCR. The highest resistance rate was against ampicillin (100.0%). Among the 104 K. pneumoniae isolates, 52 (50.0%) and 31 (29.8%) isolates were determined as multi- and extensively drug resistant (MDR, XDR), respectively. Moreover, 21 (40.4%) isolates were determined as ESBL producing. Among 50 biofilm-producing K. pneumoniae isolates, 7 (14.0%), 15 (30.0%), and 28 (56.0%) isolates exhibited high, moderate, and weak levels of biofilm formation, respectively. A number of 41 (78.8%) isolates were susceptible to colistin, and 10 (19.2%) were resistant. AMR was significantly higher (P < 0.05) in the biofilm-forming isolates compared with non-biofilm formers.}, }
@article {pmid37028211, year = {2023}, author = {Bydalek, F and Webster, G and Barden, R and Weightman, AJ and Kasprzyk-Hordern, B and Wenk, J}, title = {Microplastic biofilm, associated pathogen and antimicrobial resistance dynamics through a wastewater treatment process incorporating a constructed wetland.}, journal = {Water research}, volume = {235}, number = {}, pages = {119936}, doi = {10.1016/j.watres.2023.119936}, pmid = {37028211}, issn = {1879-2448}, abstract = {Microplastics in wastewater are colonized by biofilms containing pathogens and antimicrobial resistance (AMR) genes that can be exported into receiving water bodies. This study investigated establishment and changes in microplastic-associated biofilm and AMR during a conventional full-scale 2100 population equivalent wastewater treatment process combined with a free water surface polishing constructed wetland. Sequential microplastic colonization experiments were conducted at different stages of the wastewater treatment process, including in raw sewage, treated effluent and the constructed wetland. Two scenarios were tested in which the constructed wetland served as either (i) a polishing step or (ii) as primary recipient of sewage inoculated microplastics. Bacterial 16S rRNA gene sequencing was carried out for qualitative bacterial community analysis. qPCR was applied for quantitative analysis of AMR genes (sul1, ermB, tetW, intiI1), bacterial biomass (16S rRNA) and a human fecal marker (HF183). Microbial diversity on microplastics increased with incubation time. The initial sewage-derived biofilm composition changed more significantly in the wastewater effluent compared to the constructed wetland. Pathogen and AMR load decreased by up to two orders of magnitude after coupled conventional and constructed wetland treatment, while less impact was observed when sewage-inoculated microplastic material was directly transferred into the constructed wetland. Aeromonas, Klebsiella, and Streptococcus were key pathogenic genera correlated with AMR in microplastic-associated biofilms. Despite decreasing trends on human pathogens and AMR load along the treatment process, microplastic-associated biofilms were a considerable potential hotspot for AMR (intI1 gene) and accommodated Cyanobacteria and fish pathogens.}, }
@article {pmid37027924, year = {2023}, author = {Zhang, J and Shao, Y and Li, Z and Han, G and Jing, X and Wang, N and Xu, J and Chen, G}, title = {Characteristics analysis of plastisphere biofilm and effect of aging products on nitrogen metabolizing flora in microcosm wetlands experiment.}, journal = {Journal of hazardous materials}, volume = {452}, number = {}, pages = {131336}, doi = {10.1016/j.jhazmat.2023.131336}, pmid = {37027924}, issn = {1873-3336}, abstract = {The marsh, a significant terrestrial ecosystem, has steadily developed the capacity to act as a microplastics collection place (MPs). Here, 180 days of exposure to three different polymer kinds of plastics: polyethylene (PE), polystyrene (PS), and polyvinyl chloride (PVC), were conducted in miniature wetlands (CWs). Water contact angle (WCA), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and High-throughput sequencing were used to study the succession of microbial community structure and function on MPs after 0, 90, and 180 days of exposure. The results showed that different polymers were degrading and aging differing degrees; PVC contained new functional groups with the symbols -CC-, -CO-, and -OH, while PE had the biggest range of contact angles (74.0-45.5°). Bacteria colonization was discovered on plastic surfaces, and as time went on, it became increasingly evident that the surfaces' composition had altered, and their hydrophobicity had diminished. The plastisphere's microbial community structure as well as water nitrification and denitrification were altered by MPs. In general, our study created a vertical flow-built wetland environment, monitored the impacts of plastic aging and breakdown products on nitrogen metabolizing microorganisms in wetland water, and offered a reliable site for the screening of plastic-degrading bacteria.}, }
@article {pmid37025362, year = {2023}, author = {Alangari, A and Mateen, A and Alqahtani, MS and Shahid, M and Syed, R and Shaik, MR and Khan, M and Adil, SF and Kuniyil, M}, title = {Antimicrobial, anticancer, and biofilm inhibition studies of highly reduced graphene oxide (HRG): In vitro and in silico analysis.}, journal = {Frontiers in bioengineering and biotechnology}, volume = {11}, number = {}, pages = {1149588}, pmid = {37025362}, issn = {2296-4185}, abstract = {Background: Bacterial infections and cancers may cause various acute or chronic diseases, which have become serious global health issues. This requires suitable alternatives involving novel and efficient materials to replace ineffective existing therapies. In this regard, graphene composites are being continuously explored for a variety of purposes, including biomedical applications, due to their remarkable properties. Methods: Herein, we explore, in-vitro, the different biological properties of highly reduced graphene oxide (HRG), including anti-cancer, anti-bacterial, and anti-biofilm properties. Furthermore, to analyze the interactions of graphene with proteins of microbes, in silico docking analysis was also carried out. To do this, HRG was prepared using graphene oxide as a precursor, which was further chemically reduced to obtain the final product. The as-prepared HRG was characterized using different types of microscopic and spectroscopic techniques. Results: The HRG revealed significant cytotoxic ability, using a dose-dependent anti-cell proliferation approach, which substantially killed human breast cancer cells (MCF-7) with IC50 of 29.51 ± 2.68 μg/mL. The HRG demonstrated efficient biological properties, i.e., even at low concentrations, HRG exhibited efficient anti-microbial properties against a variety of microorganisms. Among the different strains, Gram-positive bacteria, such as B. subtilis, MRSA, and S. aureus are more sensitive to HRG compared to Gram-negative bacteria. The bactericidal properties of HRG are almost similar to a commercially available effective antibiotic (ampicillin). To evaluate the efficacy of HRG against bacterial biofilms, Pseudomonas aeruginosa and MRSA were applied, and the results were compared with gentamycin and ampicillin, which are commonly applied standard antibiotics. Notably, HRG demonstrated high inhibition (94.23%) against P.aeruginosa, with lower MIC (50 μg/mL) and IC50 (26.53 μg/mL) values, whereas ampicillin and gentamicin showed similar inhibition (90.45% and 91.31% respectively) but much higher MIC and IC50 values. Conclusion: Therefore, these results reveal the excellent biopotential of HRG in different biomedical applications, including cancer therapy; antimicrobial activity, especially anti-biofilm activity; and other biomedicine-based therapies. Based on the molecular docking results of Binding energy, it is predicted that pelB protein and HRG would form the best stable docking complex, and high hydrogen and hydrophobic interactions between the pelB protein and HRG have been revealed. Therefore, we conclude that HRG could be used as an antibiofilm agent against P. aeruginosa infections.}, }
@article {pmid37024695, year = {2023}, author = {Ajetunmobi, OH and Wall, G and Bonifacio, BV and Montelongo-Jauregui, D and Lopez-Ribot, JL}, title = {A 384-Well Microtiter Plate Model for Candida Biofilm Formation and Its Application to High-Throughput Screening.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2658}, number = {}, pages = {53-64}, pmid = {37024695}, issn = {1940-6029}, abstract = {Candidiasis, infections caused by Candida spp., represents one of the most common nosocomial infections afflicting an expanding number of compromised patients. Antifungal therapeutic options are few and show limited efficacy. Moreover, biofilm formation is frequently associated with different manifestations of candidiasis and further complicates therapy. Thus, there is an urgent need for new effective therapeutic agents, particularly those with anti-biofilm activity. Here we describe the development of a novel, simple, fast, economical, and highly reproducible 384-well microtiter plate model for the formation of both Candida albicans and Candida auris biofilms and its application in high-throughput screening (HTS) techniques.}, }
@article {pmid37024470, year = {2023}, author = {Young, E and Melaugh, G and Allen, RJ}, title = {Active layer dynamics drives a transition to biofilm fingering.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {17}, pmid = {37024470}, issn = {2055-5008}, abstract = {The emergence of spatial organisation in biofilm growth is one of the most fundamental topics in biofilm biophysics and microbiology. It has long been known that growing biofilms can adopt smooth or rough interface morphologies, depending on the balance between nutrient supply and microbial growth; this 'fingering' transition has been linked with the average width of the 'active layer' of growing cells at the biofilm interface. Here we use long-time individual-based simulations of growing biofilms to investigate in detail the driving factors behind the biofilm-fingering transition. We show that the transition is associated with dynamical changes in the active layer. Fingering happens when gaps form in the active layer, which can cause local parts of the biofilm interface to pin, or become stationary relative to the moving front. Pinning can be transient or permanent, leading to different biofilm morphologies. By constructing a phase diagram for the transition, we show that the controlling factor is the magnitude of the relative fluctuations in the active layer thickness, rather than the active layer thickness per se. Taken together, our work suggests a central role for active layer dynamics in controlling the pinning of the biofilm interface and hence biofilm morphology.}, }
@article {pmid37024282, year = {2023}, author = {Sanford, PA and Miller, KG and Hoyt, KO and Woolston, BM}, title = {Deletion of biofilm synthesis in Eubacterium limosum ATCC 8486 improves handling and transformation efficiency.}, journal = {FEMS microbiology letters}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsle/fnad030}, pmid = {37024282}, issn = {1574-6968}, abstract = {Eubacterium limosum is an acetogenic bacterium of potential industrial relevance for its ability to efficiently metabolize a range of single carbon compounds. However, extracellular polymeric substance (EPS) produced by the type strain ATCC 8486 is a serious impediment to bioprocessing and genetic engineering. To remove these barriers, here we bioinformatically identified genes involved in EPS biosynthesis, and targeted several of the most promising candidates for inactivation, using a homologous recombination-based approach. Deletion of a single genomic region encoding homologues for epsABC, ptkA, and tmkA resulted in a strain incapable of producing EPS. This strain is significantly easier to handle by pipetting and centrifugation, and retains important wild-type phenotypes including the ability to grow on methanol and carbon dioxide and limited oxygen tolerance. Additionally, this strain is also more genetically tractable with a two-fold increase in transformation efficiency compared to the highest previous reports. This work advances a simple, rapid protocol for gene knockouts in E. limosum using only the native homologous recombination machinery. These results will hasten the development of this organism as a workhorse for valorization of single carbon substrates, as well as facilitate exploration of its role in the Human gut microbiota.}, }
@article {pmid37024280, year = {2023}, author = {Carrié, M and Gabelle, JC and Lopes-Ferreira, N and Velly, H}, title = {Enzymatic breakdown of biofilm matrix to allow flow cytometry viability analysis of Clostridium beijerinckii cells.}, journal = {Journal of applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jambio/lxad062}, pmid = {37024280}, issn = {1365-2672}, abstract = {AIMS: Flow cytometry (FC) is a good way to enumerate the number of viable cells in suspension but is not adapted to mature biofilm analysis. The aim of this study is to investigate the effect of mechanical treatment coupled with enzymatic hydrolysis of biofilm matrix on FC viability analysis of biofilm cells.<br><br>METHODS AND RESULTS: Biofilm was grown for 300&#xa0;h of continuous fermentation on polyurethane foams. Fermentation was stopped and the biofilm was detached by agitating the foams in PBS buffer with vortex agitation for two minutes. The best enzymatic hydrolysis consisted of sequential use of DNase I and proteinase K incubated for 1&#xa0;h at 34&#xb0;C. Biofilm cells detached from polyurethane foams were stained with both propidium iodide (PI) and carboxy fluoresceine diacetate (cFDA) and analyzed by FC. FC analysis performed after vortex agitation revealed the presence of high non-fluorescent events (78.9&#xa0;&#xb1;&#xa0;3.3%). After enzymatic treatment, a cell population was extracted from background noise and could be observed on FSC-SSC profile. The non-fluorescent events of this cell population decreased drastically to 41.9&#xa0;&#xb1;&#xa0;6.6% and the percentage of viable cells was enhanced from 2.6&#xa0;&#xb1;&#xa0;0.9% to 38.2&#xa0;&#xb1;&#xa0;4.0% compared to analysis performed after mechanical treatment alone.<br><br>CONCLUSIONS: Consequently, protease and nuclease activity are essential to hydrolyze EPS prior to FC viability analysis in mature biofilm formed by C. beijerinckii.}, }
@article {pmid37022591, year = {2023}, author = {Xin, C and Wang, F and Zhang, J and Zhou, Q and Liu, F and Zhao, C and Song, Z}, title = {Erratum: Secretions from Serratia marcescens Inhibit the Growth and Biofilm Formation of Candida spp. and Cryptococcus neoformans.}, journal = {Journal of microbiology (Seoul, Korea)}, volume = {}, number = {}, pages = {}, doi = {10.1007/s12275-023-00037-5}, pmid = {37022591}, issn = {1976-3794}, }
@article {pmid37021122, year = {2023}, author = {Guo, L and Dai, H and Feng, S and Zhao, Y}, title = {Contribution of GalU to biofilm formation, motility, antibiotic and serum resistance, and pathogenicity of Salmonella Typhimurium.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1149541}, pmid = {37021122}, issn = {2235-2988}, mesh = {Mice ; Chick Embryo ; Animals ; Virulence/genetics ; *Salmonella typhimurium/genetics ; *Anti-Bacterial Agents ; Chickens ; Biofilms ; Bacterial Proteins/genetics ; }, abstract = {INTRODUCTION: Salmonella Typhimurium is the leading cause of foodborne illnesses in China, resulting in major epidemics and economic losses in recent years. Uridine diphosphate-glucose pyrophosphorylase galU plays an important role in thebiosynthesis of the bacterial envelope. Herein, we evaluated the role of galU in S. Typhimurium infection in chicken.<br><br>METHODS: A galU gene mutant was successfully constructed by red homologous recombination technology, and biological characteristics were studied.<br><br>RESULTS: The galU mutant strain had a rough phenotype;was defective in biofilm formation, autoagglutination, and motility; exhibited greater sensitivity to most antibiotics, serum, and egg albumen; and had lowercapacity for adhesion to chicken embryo fibroblasts cell line (DF-1). The galU mutant showed dramatically attenuated pathogenicity in chicken embryos (100,000-fold), BALB/c mice (420-fold), and chicks (100-fold).<br><br>DISCUSSION: The results imply that galU is an important virulence factor in the pathogenicity of S. Typhimurium, and it may serve a target for the development of veterinary drugs, providing a theoretical basis for the prevention and control of S. Typhimurium.}, }
@article {pmid37020863, year = {2023}, author = {Nystedt, HL and Grønlien, KG and Rolfsnes, RR and Winther-Larsen, HC and Løchen Økstad, OA and Tønnesen, HH}, title = {Neutral natural deep eutectic solvents as anti-biofilm agents.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100114}, pmid = {37020863}, issn = {2590-2075}, abstract = {Natural deep eutectic solvents (NADES) are a class of liquids with promising properties as components in pharmaceutical formulations, such as a low toxicity profile, biodegradability and versatility. Recently, their potential use as anti-biofilm agents has been proposed, due to their ability to solubilize and stabilize biological macromolecules. In the current work, the ability to break down biofilm matrix and the biofilm killing activity of three NADES of neutral pH were investigated against Staphylococcus aureus ATCC 6538 and Pseudomonas aeruginosa ATCC 9027 biofilms. The tested NADES were choline chloride:xylitol (ChX), choline chloride:glycerol (ChG) and betaine:sucrose (BS). Two of the NADES (ChX and ChG) significantly reduced the number of remaining viable cells of both bacterial species in pre-formed biofilm by 4-6 orders of magnitude, while the average biofilm biomass removal for all NADES was 27-67% (S. aureus) and 34-49% (P. aeruginosa). The tested NADES also inhibited biofilm formation of both bacterial species at concentrations at or below 0.5 x the minimal inhibitory concentration (MIC), possibly in part due to observed restrictions imposed by NADES on planktonic growth. These results demonstrate the potential value of neutral NADES as anti-biofilm agents in future antimicrobial preparations.}, }
@article {pmid37019921, year = {2023}, author = {Patkowski, JB and Dahlberg, T and Amin, H and Gahlot, DK and Vijayrajratnam, S and Vogel, JP and Francis, MS and Baker, JL and Andersson, M and Costa, TRD}, title = {The F-pilus biomechanical adaptability accelerates conjugative dissemination of antimicrobial resistance and biofilm formation.}, journal = {Nature communications}, volume = {14}, number = {1}, pages = {1879}, pmid = {37019921}, issn = {2041-1723}, abstract = {Conjugation is used by bacteria to propagate antimicrobial resistance (AMR) in the environment. Central to this process are widespread conjugative F-pili that establish the connection between donor and recipient cells, thereby facilitating the spread of IncF plasmids among enteropathogenic bacteria. Here, we show that the F-pilus is highly flexible but robust at the same time, properties that increase its resistance to thermochemical and mechanical stresses. By a combination of biophysical and molecular dynamics methods, we establish that the presence of phosphatidylglycerol molecules in the F-pilus contributes to the structural stability of the polymer. Moreover, this structural stability is important for successful delivery of DNA during conjugation and facilitates rapid formation of biofilms in harsh environmental conditions. Thus, our work highlights the importance of F-pilus structural adaptations for the efficient spread of AMR genes in a bacterial population and for the formation of biofilms that protect against the action of antibiotics.}, }
@article {pmid37018485, year = {2023}, author = {Park, S and Kumar, S and Maier, CS and Kreth, J and Koley, D}, title = {Simultaneous Chemical Mapping of Live Biofilm Microenvironmental pH and Hydrogen Peroxide in Real Time with a Triple Scanning Electrochemical Microscopy Tip.}, journal = {Analytical chemistry}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.analchem.2c05258}, pmid = {37018485}, issn = {1520-6882}, abstract = {Dental plaque biofilm is a complex ecosystem. The distribution of microbial species in the biofilm is heavily influenced by local chemical interactions that result from diverse metabolic activities and the nature of the released molecules. As a relevant example, H2O2-producing bacteria can antagonize disease-associated bacteria, leading to the maintenance of a healthy oral microbiome. Herein, we report the development of a triple-sensor (redox, pH, and H2O2) scanning electrochemical microscopy (SECM) tip capable of simultaneously mapping the pH and H2O2 concentration produced by a dental plaque-derived multispecies biofilm grown on hydroxyapatite. The pH sensor of the triple SECM tip showed a near Nernstian slope of -71.1 ± 2 mV/pH (N = 3), whereas the H2O2 sensor showed a slope of -0.052 ± 0.002 nA/μM H2O2 at pH 7.2 and a detection limit of 1.0 ± 0.2 μM (N = 7). There is no significant difference in the sensitivities of H2O2 sensors at pH 6.2, 7.2, and 8.2 at 95% CI (N = 7). The pH and H2O2 sensors demonstrated excellent reversibility with response times of 3 and 5 s, respectively, along with reliable stability over 4 h at 37 °C. The sensors did not show any cross talk between pH and H2O2 concentration ([H2O2]) measurements, highlighting the accuracy and versatility of the SECM tip. Simultaneous chemical imaging of pH and [H2O2] across the biofilm revealed a clustered distribution of local H2O2 concentrations, ranging from 0 to 17 μM. Conversely, the local pH remained constant at 7.2. The relation of local chemical profiles and the distribution of bacterial species within the oral microbiome was experimentally investigated in the context of bacterial H2O2 antagonism. The benefit of clustered H2O2 production was that the total area of H2O2 produced by smaller clusters was 67% more than that of a single cluster with the same starting number of bacteria. Thus, this triple SECM tip can potentially be used to study local molecular mechanisms that result in dysbiosis of the oral microbiome.}, }
@article {pmid37017538, year = {2023}, author = {Jonsdottir, I and Given, C and Penttinen, R and Jalasvuori, M}, title = {Preceding Host History of Conjugative Resistance Plasmids Affects Intra- and Interspecific Transfer Potential from Biofilm.}, journal = {mSphere}, volume = {}, number = {}, pages = {e0010723}, doi = {10.1128/msphere.00107-23}, pmid = {37017538}, issn = {2379-5042}, abstract = {Conjugative plasmids can confer antimicrobial resistance (AMR) to their host bacterium. The plasmids disperse even between distantly related host species, rescuing the host from otherwise detrimental effects of antibiotics. Little is known about the role of these plasmids in the spread of AMR during antibiotic treatment. One unstudied question is whether the past evolutionary history of a plasmid in a particular species creates host specificity in its rescue potential or if interspecific coevolution can improve interspecific rescues. To study this, we coevolved the plasmid RP4 under three different host settings; solely Escherichia coli or Klebsiella pneumoniae, or alternating between both of them. The ability of evolved plasmids in bacterial biofilm to rescue susceptible planktonic host bacteria of either the same or different species during beta-lactam treatment was tested. The interspecific coevolution seemed to decrease rescue potential for the RP4 plasmid, while the K. pneumoniae evolved plasmid became more host specific. Large deletion in the region encoding the mating pair formation (Tra2) apparatus was detected in the plasmids evolved with K. pneumoniae. This adaptation resulted in the exapted evolution of resistance against a plasmid-dependent bacteriophage PRD1. Further, previous studies have suggested that mutations in this region completely abolish the plasmid's ability to conjugate; however, our study shows it is not essential for conjugation but rather affects the host-specific conjugation efficiency. Overall, the results suggest that previous evolutionary history can result in the separation of host-specific plasmid lineages that may be further amplified by unselected exaptations such as phage resistance. IMPORTANCE Antimicrobial resistance (AMR) is a major global public health threat which can rapidly spread in microbial communities via conjugative plasmids. Here, we advance with evolutionary rescue via conjugation in a more natural setting, namely, biofilm, and incorporate a broad-host range plasmid RP4 to test whether intra- and interspecific host histories affect its transfer potential. Escherichia coli and Klebsiella pneumoniae hosts were seen to elicit different evolutionary influences on the RP4 plasmid, leading to clear differences in the rescue potential and underlining the significant role of the plasmid-host interactions in the spread of AMR. We also contradicted previous reports that established certain conjugal transfer genes of RP4 as essential. This work enhances the understanding of how plasmid host range evolve in different host settings and further, the potential effects it may have on the horizontal spread of AMR in complex environments such as biofilms.}, }
@article {pmid37013928, year = {2023}, author = {Dash, P and Rana, K and Turuk, J and Palo, SK and Pati, S}, title = {Antimicrobial Resistance and Biofilm Formation of Staphylococcus aureus Isolates from Febrile Cases: Findings from a Rural Cohort of Odisha, India.}, journal = {Polish journal of microbiology}, volume = {}, number = {}, pages = {}, doi = {10.33073/pjm-2023-005}, pmid = {37013928}, issn = {2544-4646}, abstract = {This study investigated the major pathogens in fever patients' blood in a rural cohort and characterized its virulence. A total of 718 blood samples received from IPD/OPD (inpatient department/outpatient department) patients with H/O (history of) fever were cultured, and 73 out of 83 culture-positive samples were identified as Staphylococcus aureus. The isolates showed higher resistance to penicillin, most being multidrug resistant. They formed biofilm in vitro, and 27.4% of the isolates were strong biofilm producers. They were sensitive towards linezolid, gentamicin, and tetracycline. The findings emphasize the necessity of preventing and managing staphylococcal infection and regular antimicrobial surveillance in rural areas.}, }
@article {pmid37012571, year = {2023}, author = {Wang, Y and Xu, X and Zhang, S and Zhang, X and Ga, Z and Yan, Q and Lu, Y and Zuo, L and Wang, G}, title = {Vertical patterns of leaf physiology and biofilm characteristics for Hydrilla verticillata in both single and mixed communities.}, journal = {Environmental science and pollution research international}, volume = {}, number = {}, pages = {}, pmid = {37012571}, issn = {1614-7499}, abstract = {Little is known about how community composition affects vertical patterns of leaf characteristics for submerged macrophytes in freshwater lakes. Here, after sampling Hydrilla verticillata in both single and mixed communities in shallow and deep areas in a shallow lake, we measured vertical patterns of leaf biofilm and physiology characteristics. Upper leaves of H. verticillata always had more attached abiotic biofilm matters, and all biofilm characteristics exhibited declining trends from top to bottom segments in deep areas. Moreover, the amount of attached biofilm matter in the mixed community was less than in the single community in shallow areas, but the reverse was true in deep areas. The vertical pattern of leaf physiology characteristics was obvious in the mixed community. In the shallow area, leaf pigment concentrations showed increasing trends with an increasing water depth, but the enzymatic specific activity of peroxidase (POD-ESA) was precisely the opposite. In the deep area, leaf chlorophyll concentrations were greatest in the leaves of bottom segments and lowest in top segments, while carotenoids and POD-ESA were greatest in the leaves of the middle segment-II. Light intensity and biofilm were found to play an important role in regulating the vertical patterns of photosynthetic pigments and POD-ESA. Our study highlighted the effect of community composition on the vertical pattern of leaf physiology and biofilm characteristics. HIGHLIGHTS: Biofilm characteristics always showed increasing trends with increasing water depth. Community composition changed the amount of attached biofilm matter. The vertical pattern of leaf physiology was more obvious in mixed communities. Light intensity and biofilm regulated the vertical pattern of leaf physiology.}, }
@article {pmid37011602, year = {2023}, author = {Li, M and Yu, J and Guo, G and Shen, H}, title = {Interactions between macrophages and biofilm during Staphylococcus aureus-associated implant infection: difficulties and solutions.}, journal = {Journal of innate immunity}, volume = {}, number = {}, pages = {}, doi = {10.1159/000530385}, pmid = {37011602}, issn = {1662-8128}, abstract = {Staphylococcus aureus (S. aureus) biofilm is the major cause of failure of implant infection treatment that results in heavy social and economic burden on individuals, families, and communities. Planktonic S. aureus attaches to medical implant surfaces where it proliferates and is wrapped by extracellular polymeric substances (EPS), forming a solid and complex biofilm. This provides a stable environment for bacterial growth, infection maintenance, and diffusion, and protects the bacteria from antimicrobial agents and the immune system of the host. Macrophages are an important component of the innate immune system, and resist pathogen invasion and infection through phagocytosis, antigen presentation, and cytokine secretion. The persistence, spread, or clearance of infection is determined by interplay between macrophages and S. aureus in the implant infection microenvironment. In this review, we discuss the interactions between S. aureus biofilm and macrophages, including the effects of biofilm-related bacteria on the macrophage immune response, roles of myeloid-derived suppressor cells during biofilm infection, regulation of immune cell metabolic patterns by the biofilm environment, and immune evasion strategies adopted by the biofilm against macrophages. Finally, we summarize the current methods that support macrophage mediated removal of biofilms and emphasize the importance of considering multi-dimensions and factors related to implant associated infection such as immunity, metabolism, the host, and the pathogen when developing new treatments.}, }
@article {pmid37010966, year = {2023}, author = {Serbanescu, MA and Apple, CG and Fernandez-Moure, JS}, title = {Role of Resident Microbial Communities in Biofilm-Related Implant Infections: Recent Insights and Implications.}, journal = {Surgical infections}, volume = {24}, number = {3}, pages = {258-264}, doi = {10.1089/sur.2023.009}, pmid = {37010966}, issn = {1557-8674}, mesh = {Humans ; *Staphylococcal Infections ; Biofilms ; Postoperative Complications ; *Microbiota ; Prostheses and Implants/adverse effects ; }, abstract = {The use of medical implants continues to grow as the population ages. Biofilm-related implant infection is the leading cause of medical implant failure and remains difficult to diagnose and treat. Recent technologies have enhanced our understanding of the composition and complex functions of microbiota occupying various body site niches. In this review, we leverage data from molecular sequencing technologies to explore how silent changes in microbial communities from various sites can influence the development of biofilm-related infections. Specifically, we address biofilm formation and recent insights of the organisms involved in biofilm-related implant infections; how composition of microbiomes from skin, nasopharyngeal, and nearby tissue can impact biofilm-formation, and infection; the role of the gut microbiome in implant-related biofilm formation; and therapeutic strategies to mitigate implant colonization.}, }
@article {pmid37009860, year = {2023}, author = {Hirose, S and Asano, T and Hamada, M and Morohoshi, S and Kunihiro, T and Hanada, S}, title = {Roseomonas fluvialis sp. nov., an aerobic bacteriochlorophyll a-containing freshwater bacterium isolated from river epilithic biofilm.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {73}, number = {3}, pages = {}, doi = {10.1099/ijsem.0.005810}, pmid = {37009860}, issn = {1466-5034}, mesh = {*Fatty Acids/chemistry ; Rivers/microbiology ; Bacteriochlorophyll A ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; DNA, Bacterial/genetics ; Base Composition ; Bacterial Typing Techniques ; Sequence Analysis, DNA ; Ubiquinone ; *Methylobacteriaceae ; Biofilms ; Phospholipids ; }, abstract = {A strictly aerobic bacteriochlorophyll a-containing alphaproteobacterium, designated strain S08[T], was isolated from a biofilm sampled at Tama River in Japan. The non-motile and rod-shaped cells formed pink-beige pigmented colonies on agar plates containing organic compounds and showed in vivo absorption maxima at 798 and 866 nm in the near-infrared region, typical for the presence of bacteriochlorophyll a. The new bacterial isolate is Gram-negative, oxidase-negative and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain S08[T] was closely related to species in the genus Roseomonas. The closest phylogenetic relative of strain S08[T] was Roseomonas lacus TH-G33[T] (98.2 % sequence similarity). The major cellular fatty acids were C16 : 0, C18 : 1 2-OH and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c). The predominant respiratory quinone was ubiquinone-9. The major polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an aminolipid. The G+C content of the genomic DNA was 70.6 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain S08[T] and the related Roseomonas type strains were all far lower than the cut-off value for the delineation of species. The results of polyphasic comparisons showed that strain S08[T] was clearly distinguishable from other members of the genus Roseomonas. Therefore, we propose a new species in the genus Roseomonas, namely, Roseomonas fluvialis sp. nov. The type strain is S08[T] (=DSM 111902[T]=NBRC 112025[T]).}, }
@article {pmid37007057, year = {2023}, author = {Hu, Z and Tang, Y and Jiang, B and Xu, Y and Liu, S and Huang, C}, title = {Functional liposome loaded curcumin for the treatment of Streptococcus mutans biofilm.}, journal = {Frontiers in chemistry}, volume = {11}, number = {}, pages = {1160521}, pmid = {37007057}, issn = {2296-2646}, abstract = {Introduction: Plaque biofilms, mainly formed by Streptococcus mutans (S. mutans), play an important role in the occurrence and development of dental caries. Antibiotic treatment is the traditional way to control plaque. However, problems such as poor drug penetration and antibiotic resistance have encouraged the search for alternative strategies. In this paper, we hope to avoid antibiotic resistance through the antibacterial effect of curcumin, a natural plant extract with photodynamic effects, on S. mutans. However, the clinical application of curcumin is limited due to its low water solubility, poor stability, high metabolic rate, fast clearance rate, and limited bioavailability. In recent years, liposomes have become a widely used drug carrier due to their numerous advantages, such as high drug loading efficiency, high stability in the biological environment, controlled release, biocompatibility, non-toxic, and biodegradability. So, we constructed a curcumin-loaded liposome (Cur@LP) to avoid the defect of curcumin. Methods: Cur@LP functioned with NHS can adhere to the surface of the S. mutans biofilm by condensation reaction. Liposome (LP) and Cur@LP was characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The cytotoxicity of Cur@LP was evaluated by CCK-8 assay and LDH assay. The adhesion of Cur@LP to S. mutans biofilm was observed by confocal laser scanning microscope (CLSM). The antibiofilm efficiency of Cur@LP were evaluated by crystal violet staining, CLSM, and scanning electron microscope (SEM). Results: The mean diameter of LP and Cur@LP were 206.67 ± 8.38 nm and 312 ± 18.78 nm respectively. The ζ-potential of LP and Cur@LP were ∼-19.3 mV and ∼-20.8 mV respectively. The encapsulation efficiency of Cur@LP was (42.61 ± 2.19) %, and curcumin was rapidly released up to ±21% at 2 h. Cur@LP has negligible cytotoxicity, and can effectively adhered to the S. mutans biofilm and inhibited its growth. Discussion: Curcumin has been widely studied in many fields such as cancer, which can be attributed to its antioxidant and anti-inflammatory effects. At present, there are few studies on the delivery of curcumin to S. mutans biofilm. In this study, we verified the adhesion and antibiofilm of Cur@LP to S. mutans biofilm. This biofilm removal strategy has the potential to be translated into the clinic.}, }
@article {pmid37005968, year = {2023}, author = {Yu, F and Dong, C and Zhang, Y and Che, R and Xie, C and Liu, Y and Zhang, Z and Li, L and Chen, X and Cai, X and Wang, G and Li, Y}, title = {GrpE and ComD contribute to the adherence, biofilm formation, and pathogenicity of Streptococcus suis.}, journal = {Archives of microbiology}, volume = {205}, number = {4}, pages = {159}, pmid = {37005968}, issn = {1432-072X}, mesh = {Animals ; Swine ; Virulence ; *Streptococcus suis/genetics ; Biofilms ; Cytokines/metabolism ; Brain ; Disease Models, Animal ; Bacterial Proteins/genetics/metabolism ; }, abstract = {Streptococcus suis is a major bacterial pathogen of swine and an emerging zoonotic agent that has to date resulted in substantial economic losses to the swine industry worldwide, and can cause persistent infection by forming biofilms. GrpE and histidine protein kinase ComD are important proteins implicated in the pathogenicity of S. suis, although whether they play roles in adhesion and biofilm formation has yet to be sufficiently clarified. In this study, we constructed grpE and comD deletion strains of S. suis by homologous recombination, and examined their cell adhesion and biofilm formation capacities compared with those of the wild-type strain. The pathogenicity of the grpE and comD deletion strains was evaluated using a mouse infection model, which revealed that compared with the wild-type, these deletion strains induced milder symptoms and lower bacteremia, as well as comparatively minor organ (brain, spleen, liver, and lung) lesions, in the infected mice. Moreover, the deletion of grpE and comD significantly reduced the pro-inflammatory cytokine (IL-6, IL-1β, and TNF-α) induction capacity of S. suis. Collectively, the findings of this study indicate that the GrpE and ComD proteins of Streptococcus suis play key roles in the adherence to PK-15 cells and the formation of biofilms, thereby contributing to the virulence of this pathogen.}, }
@article {pmid37004897, year = {2023}, author = {Koskeroglu, K and Barel, M and Hizlisoy, H and Yildirim, Y}, title = {"Biofilm Formationand Antibiotic Resistance Profiles of Water-borne Pathogens.}, journal = {Research in microbiology}, volume = {}, number = {}, pages = {104056}, doi = {10.1016/j.resmic.2023.104056}, pmid = {37004897}, issn = {1769-7123}, abstract = {Water sources (surface water, drinking water, rivers, and ponds) are significant reservoirs for transmitting antibiotic-resistant bacteria. In addition, these waters are an important public health problem because they are suitable environments for transferring antibiotic resistance genes between bacterial species. Our study aimed to assess the prevalence of Extended-spectrum beta-lactamase (ESBL) producing isolates in water samples, the susceptibility of the isolates to the specified antibiotics, the determination of biofilm ability, antibiotic resistance genes, and the molecular typing of the isolates. For this purpose, Polymerase chain reaction (PCR) and Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analyses were used. Out of 70 isolates, 15 (21%) were ESBL producing, and sent for the MALDI-TOF analysis, where Escherichia coli, Acinetobacter calcoaceticus, Enterobacter bugandensis, Acinetobacter pittii, Pseudomonas aeruginosa, Acinetobacter junii, Pseudomonas oleovorans, and Enterobacter ludwigigii were identified. Moreover, colistin resistance genes (mcr1/2/6, mcr 4, mcr 5, mcr 3/7, and mcr 8), ESBL-encoding genes(blaSHV, blaTEM, and blaCTX-M) and carbapenemase genes (blaNDM, blaOXA-48, and blaKPC) using molecular analysis (PCR) were confirmed. The colistin resistance gene was detected at 80% (12/15) in the isolates obtained. The distribution of these isolates according to resistance genes was found as mcr 1/2/6 4 (20%), mcr3/7 3 (13%), and mcr 5 (40%). Additionally, the isolates harbored blaSHV(6.6%) and blaTEM (6.6%) genes. However, blaNDM, blaOXA-48, blaKPC, and blaCTX-M genes were not detected in any isolates. According to the Congo red agar method, seven (46.6%) isolates showed negative biofilm ability, and eight (53.3%) showed moderate biofilm ability. However, the microplate method detected weak biofilm in 53.3% of the isolates.In conclusion, this study provides evidence for the existence of multidrug-resistant bacteria that co-exist with mcr and ESBL genes in water sources. These bacteria can migrate to other environments and pose increasing threats to public health.}, }
@article {pmid37004854, year = {2023}, author = {Jiao, P and Tian, Q and Sand, W and Dong, X and Wu, Y}, title = {Cold-resistant performance and the promoted development of functional community with flexible metabolic patterns in a Biofilm Bio-Nutrient Removal (BBNR) system amended with supplementary carbon source for phosphorus recovery.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115807}, doi = {10.1016/j.envres.2023.115807}, pmid = {37004854}, issn = {1096-0953}, abstract = {The need for recovery of phosphorus (P) from wastewater has accelerated the retrofitting of existing bio-nutrient removal (BNR) processes into bio-nutrient removal-phosphorus recovery processes (BNR-PR). A periodical carbon source supplement is needed to facilitate the P-recovery. But the impact of this amendment on the cold resistances of the reactor and the functional microorganisms (for nitrogen and phosphorus (P) removal/recovery) are still unknown. This study presents the performances of a biofilm BNR process with a carbon source regulated the P recovery (BBNR-CPR) process operating at different temperatures. When the temperature was decreased from 25 ± 1 °C to 6 ± 1 °C, the system total nitrogen and total phosphorus removals and the corresponding kinetic coefficients decreased moderately. The indicative genes of the phosphorus-accumulating organisms (e.g., Thauera spp. and Candidatus Accumulibacter spp.) increased significantly. An increase of Nitrosomonas spp. genes aligned to polyhydroxyalkanoates (PHAs), glycine, and extracellular polymeric substance synthesis were observed, which was probably related to cold resistance. The results provide a new vision for understanding the advantages of P recovery-targeted carbon source supplementation for constructing a new type of cold-resistant BBNR-CPR processes.}, }
@article {pmid37004772, year = {2023}, author = {Zhou, Z and Ma, W and Li, F and Zhong, D and Zhang, W and Liu, L and Zhang, J and Zhu, Y and Su, P}, title = {Deciphering the distribution and microbial secretors of extracellular polymeric substances associated antibiotic resistance genes in tube wall biofilm.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {163218}, doi = {10.1016/j.scitotenv.2023.163218}, pmid = {37004772}, issn = {1879-1026}, abstract = {Antibiotics and disinfectants have both been proposed to exert selective pressures on the biofilm as well as affecting the emergence and spread of antibiotic resistance genes (ARGs). However, the transfer mechanism of ARGs in drinking water distribution system (DWDS) under the coupling effect of antibiotics and disinfectants has not been completely understood. In the current study, four lab-scale biological annular reactors (BARs) were constructed to evaluate the effects of sulfamethoxazole (SMX) and NaClO coupling in DWDS and reveal the related mechanisms of ARGs proliferation. TetM was abundant in both the liquid phase and the biofilm, and redundancy analysis showed that the total organic carbon (TOC) and temperature were significantly correlated with ARGs in the water phase. There was a significant correlation between the relative abundance of ARGs in the biofilm phase and extracellular polymeric substances (EPS). Additionally, the proliferation and spread of ARGs in water phase were related to microbial community structure. Partial least-squares path modeling showed that antibiotic concentration may influence ARGs by affecting MGEs. These findings help us to better understand the diffusion process of ARGs in drinking water and provide a theoretical support for technologies to control ARGs at the front of pipeline.}, }
@article {pmid37004626, year = {2023}, author = {Gryson, L and Meaume, S and Feldkaemper, I and Favalli, F}, title = {Anti-biofilm Activity of Povidone-Iodine and Polyhexamethylene Biguanide: Evidence from In Vitro Tests.}, journal = {Current microbiology}, volume = {80}, number = {5}, pages = {161}, pmid = {37004626}, issn = {1432-0991}, abstract = {Biofilm in chronic wounds is associated with delayed healing and ineffective local treatment. The purpose of this study was to investigate the in vitro anti-biofilm activity of two commonly used antimicrobials, povidone-iodine (PVP-I) and polyhexamethylene biguanide (PHMB). The rate of anti-biofilm activity of PVP-I, PHMB, and phosphate-buffered saline (negative control) was assessed on monomicrobial biofilms of varying maturity and composition. Antimicrobial efficacy was determined by counting colony-forming units (CFU). Live/dead cell staining and time-lapse confocal microscopy were also performed. Both PVP-I and PHMB demonstrated robust in vitro anti-biofilm activity against all tested biofilms; however, PVP-I had a more rapid action versus PHMB against methicillin-resistant Staphylococcus aureus (MRSA) biofilms, as determined by both CFU counts and microscopy. PVP-I completely eradicated Pseudomonas aeruginosa biofilms of 3- and 5-day maturity (in ≤0.5 h) and 7-day maturity (in ≤3 h), while PHMB only partially depleted cell density, with no complete biofilm eradication even after 24 h. In conclusion, PVP-I had a similar in vitro anti-biofilm activity to PHMB against biofilms of varying microbial compositions and maturity, and in some cases demonstrated more potent and rapid activity versus PHMB. PVP-I may be particularly effective in treating MRSA biofilms. However, further high-quality clinical research on the efficacy of antimicrobials is required.}, }
@article {pmid37003115, year = {2023}, author = {Wang, YC and Lv, YH and Wang, C and Jiang, GY and Han, MF and Deng, JG and Hsi, HC}, title = {Microbial community evolution and functional trade-offs of biofilm in odor treatment biofilters.}, journal = {Water research}, volume = {235}, number = {}, pages = {119917}, doi = {10.1016/j.watres.2023.119917}, pmid = {37003115}, issn = {1879-2448}, abstract = {Biofilters inoculated with activated sludge are widely used for odor control in WWTP. In this process, biofilm community evolution plays an important role in the function of reactor and is closely related to reactor performance. However, the trade-offs in biofilm community and bioreactor function during the operation are still unclear. Herein, an artificially constructed biofilter for odorous gas treatment was operated for 105 days to study the trade-offs in the biofilm community and function. Biofilm colonization was found to drive community evolution during the start-up phase (phase 1, days 0-25). Although the removal efficiency of the biofilter was unsatisfactory at this phase, the microbial genera related to quorum sensing and extracellular polymeric substance secretion led to the rapid accumulation of the biofilm (2.3 kg biomass/m[3] filter bed /day). During the stable operation phase (phase 2, days 26-80), genera related to target-pollutant degradation showed increases in relative abundance, which accompanied a high removal efficiency and a stable accumulation of biofilm (1.1 kg biomass/m[3] filter bed/day). At the clogging phase (phase 3, days 81-105), a sharp decline in the biofilm accumulation rate (0.5 kg biomass/m[3] filter bed /day) and fluctuating removal efficiency were observed. The quorum quenching-related genera and quenching genes of signal molecules increased, and competition for resources among species drove the evolution of the community in this phase. The results of this study highlight the trade-offs in biofilm community and functions during the operation of bioreactors, which could help improve bioreactor performance from a biofilm community perspective.}, }
@article {pmid37001755, year = {2023}, author = {Tong, Z and Wang, YC and Jiang, GY and Hu, XR and Xue, YM and Wang, C}, title = {A method establishment and application for biofilm quorum quenching activity assay.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138549}, doi = {10.1016/j.chemosphere.2023.138549}, pmid = {37001755}, issn = {1879-1298}, abstract = {The existence of quorum sensing (QS) and quorum quenching (QQ) plays important roles in biofilm formation. However, direct detection of QS ability is difficult due to the low concentrations of signal molecules inside the biofilm. Therefore, QQ activity is typically used to indicate the attribution of QS/QQ to the biofilm. Nevertheless, current detection methods of QQ activity based on biosensors present undesirable operability and accuracy. In this study, the 96-well plate assay based on a specific biosensor, Agrobacterium tumefaciens A136, and a colorimetric substance, X-gal was established. The reliable fitting results were obtained by standardizing the composition of the A136 X-gal assay solution and optimizing the operating conditions. This method improved the accuracy of QQ activity detection and reduced time and cost consumption. Finally, the 96-well plate assay was successfully applied to detect the QQ activities of biofilm samples and explore possible environmental influencing factors. In general, this study provided a new strategy for understanding the QQ effect in biofilm systems.}, }
@article {pmid37001699, year = {2023}, author = {Shi, S and Cao, M and Zhang, Y and Fan, X and Liu, S and Chen, J and Zhou, J}, title = {Enhanced hydrolysis/acidogenesis and potential mechanism in thermal-alkali-biofilm synergistic pretreatment of high-solid and low-organic-content sludge.}, journal = {Bioresource technology}, volume = {378}, number = {}, pages = {128988}, doi = {10.1016/j.biortech.2023.128988}, pmid = {37001699}, issn = {1873-2976}, abstract = {Improving the anaerobic digestion (AD) of high-solid and low-organic-content sludge is imperative for sustainable waste activated sludge (WAS) management. Here, a thermal-alkali-biofilm pretreatment (TAB) was established to treat high-solid and low-organic-content sludge and compared with thermal and thermal-alkali methods. The results showed that TAB drastically improved WAS reduction, hydrolysis/acidogenesis efficiency, and biochemical methane potential. TAB possessed the lowest sludge particle size and the highest surface charge due to the stimulated proteolysis and WAS solubilization, supported by the protease activity test and secondary substrate identification. In addition, the biofilm assistance noticeably accelerated the elimination of autochthonous bacteria in WAS (e.g., Proteobacteria) and facilitated the enrichment of specialized fermentative microorganisms (e.g., Firmicutes) along with relevant functional genes, lying molecular foundation for the enhanced hydrolysis/acidogenesis in TAB. These findings could expand the application of biofilm in the AD of WAS and provide new insight into the pretreatment strategy of high-solid and low-organic-content sludge.}, }
@article {pmid37001670, year = {2023}, author = {Fang, G and Wang, J and Li, M and Yang, Q and Huang, H}, title = {In-situ cathodic electrolysis coupled with hydraulic backwash inhibited biofilm formation on a backwashable carbon nanotube membrane.}, journal = {The Science of the total environment}, volume = {878}, number = {}, pages = {163130}, doi = {10.1016/j.scitotenv.2023.163130}, pmid = {37001670}, issn = {1879-1026}, abstract = {Electro-coupled membrane filtration (ECMF) is an innovative and green technology for water and wastewater treatment. However, the dynamics of biofouling development in the ECMF system has yet been determined. This fundamental question was systematically investigated in this study through laboratory dead-end ECMF experiments. It was found that the ECMF process with an applied voltage of 3 V and a backwash interval of 60 min was capable of completely eradicating membrane biofouling in an extended filtration time of 1450 min. In contrast, membrane biofouling was much severer with a longer backwash interval of 720 min or without backwash. The complemental permeate analysis and membrane characterization results revealed that biofouling during ECMF involved two sequential stages. During the first stage, dead bacteria and their degradation debris formed a loose deposit layer on the membrane surface. The continuous accumulation of this layer decreased the electrochemical performance of the membrane cathode. As such, bacteria in the top deposit layer proliferated and secreted extracellular polymeric substances, which led to irreversible fouling in the second stage. Therefore, timely removal of the initial deposit layer by hydraulic backwash was crucial in preventing irreversible membrane biofouling. These findings provided novel insights into the synergistic effects of cathodic electrolysis and hydraulic backwash for biofouling mitigation.}, }
@article {pmid36999125, year = {2023}, author = {Mamdoh, H and Hassanein, KM and Eltoony, LF and Khalifa, WA and Hamed, E and Alshammari, TO and Abd El-Kareem, DM and El-Mokhtar, MA}, title = {Clinical and Bacteriological Analyses of Biofilm-Forming Staphylococci Isolated from Diabetic Foot Ulcers.}, journal = {Infection and drug resistance}, volume = {16}, number = {}, pages = {1737-1750}, pmid = {36999125}, issn = {1178-6973}, abstract = {BACKGROUND: Diabetes mellitus is a chronic disease that is associated with increased morbidity and mortality. Unfortunately, foot ulcers and amputations due to diabetes are very common in developing countries. The purpose of this study was to characterize the clinical presentation of diabetic foot ulcer (DFU) infections, isolate the causative agent, and analyze the biofilm formation and distribution of biofilm-related genes among isolated Staphylococci.<br><br>MATERIAL AND METHODS: The study included 100 diabetic patients suffering from DFUs attending Assiut University Hospital. Swabs were collected and antimicrobial susceptibility testing of the isolates was performed. Biofilm formation was tested phenotypically among staphylococcal isolates and the frequency of different biofilm genes was analyzed by PCR. Clinical presentations of diabetic foot ulcers were correlated with bacterial genetic characteristics. Spa types were determined using DNA Gear-a software.<br><br>RESULTS: Microbiological analysis showed that 94/100 of the DFUs were positive for bacterial growth. The majority of infections were polymicrobial (54%, n=54/100). Staphylococci were the most commonly detected organisms, of which S. aureus represented 37.5% (n=24/64), S. haemolyticus 23.4% (n=15/64), S. epidermidis 34.3% (n=22/64) and other CNS 4.7% (n=3/64). Interestingly, co-infection with more than one species of Staphylococci was observed in 17.1% (n=11/64) of samples. A high level of antibiotic resistance was observed, where 78.1% (n=50/64) of Staphylococci spp were multidrug-resistant (MDR). Phenotypic detection showed that all isolated Staphylococci were biofilm-formers with different grades. Analysis of biofilm-forming genes among Staphylococci showed that the most predominant genes were icaD, spa, and bap. Isolates with a higher number of biofilm-related genes were associated with strong biofilm formation. Sequencing of the spa gene in S. aureus showed that our isolates represent a collection of 17 different spa types.<br><br>CONCLUSION: The majority of DFUs in our hospital are polymicrobial. Staphylococci other than S.aureus are major contributors to infected DFUs. MDR and biofilm formation are marked among isolates, which is paralleled by the presence of different categories of virulence-related genes. All severely infected wounds were associated with either strong or intermediate biofilm formers. The severity of DFU is directly related to the number of biofilm genes.}, }
@article {pmid36997857, year = {2023}, author = {Grudlewska-Buda, K and Skowron, K and Bauza-Kaszewska, J and Budzyńska, A and Wiktorczyk-Kapischke, N and Wilk, M and Wujak, M and Paluszak, Z}, title = {Assessment of antibiotic resistance and biofilm formation of Enterococcus species isolated from different pig farm environments in Poland.}, journal = {BMC microbiology}, volume = {23}, number = {1}, pages = {89}, pmid = {36997857}, issn = {1471-2180}, abstract = {BACKGROUND: Enteroccocus spp. are human opportunistic pathogens causing a variety of serious and life-threating infections in humans, including urinary tract infection, endocarditis, skin infection and bacteraemia. Farm animals and direct contact with them are important sources of Enterococcus faecalis (EFA) and Enterococcus faecium (EFM) infections among farmers, veterinarians and individuals working in breeding farms and abattoirs. The spread of antibiotic-resistant strains is one of the most serious public health concerns, as clinicians will be left without therapeutic options for the management of enterococcal infections. The aim of the study was to evaluate the occurrence and antimicrobial susceptibility of EFA and EFM strains isolated from a pig farm environment and to determine the biofilm formation ability of identified Enterococcus spp. strains.<br><br>RESULTS: A total numer of 160 enterococcal isolates were obtained from 475 samples collected in total (33.7%). Among them, 110 of genetically different strains were identified and classified into EFA (82; 74.5%) and EFM (28; 25.5%). Genetic similarity analysis revealed the presence of 7 and 1 clusters among the EFA and EFM strains, respectively. The highest percentage of EFA strains (16; 19.5%) was resistant to high concentrations of gentamicin. Among the EFM strains, the most frequent strains were resistant to ampicillin and high concentrations of gentamicin (5 each; 17.9%). Six (7.3%) EFA and 4 (14.3%) EFM strains showed vancomycin resistance (VRE - Vancomycin-Resistant Enterococcus). Linezolid resistance was found in 2 strains of each species. The multiplex PCR analysis was performed to identify the vancomycin resistant enterococci. vanB, vanA and vanD genotypes were detected in 4, 1 and 1 EFA strains, respectively. Four EFA VRE-strains in total, 2 with the vanA and 2 with the vanB genotypes, were identified. The biofilm analysis revealed that all vancomycin-resistant E. faecalis and E. faecium strains demonstrated a higher biofilm-forming capacity, as compared to the susceptible strains. The lowest cell count (5.31 log CFU / cm[2]) was reisolated from the biofilm produced by the vancomycin-sensitive strain EFM 2. The highest level of re-isolated cells was observed for VRE EFA 25 and VRE EFM 7 strains, for which the number was 7 log CFU / cm[2] and 6.75 log CFU / cm[2], respectively.<br><br>CONCLUSIONS: The irrational use of antibiotics in agriculture and veterinary practice is considered to be one of the key reasons for the rapid spread of antibiotic resistance among microorganisms. Owing to the fact that piggery environment can be a reservoir of antimicrobial resistance and transmission route of antimicrobial resistance genes from commensal zoonotic bacteria to clinical strains, it is of a great importance to public health to monitor trends in this biological phenomenon.}, }
@article {pmid36997849, year = {2023}, author = {Liu, X and Ye, Y and Zhang, Z and Rensing, C and Zhou, S and Nealson, KH}, title = {Prophage Induction Causes Geobacter Electroactive Biofilm Decay.}, journal = {Environmental science &amp; technology}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.est.2c08443}, pmid = {36997849}, issn = {1520-5851}, abstract = {Sustaining a metabolically active electroactive biofilm (EAB) is essential for the high efficiency and durable operation of microbial fuel cells (MFCs). However, EABs usually decay during long-term operation, and, until now, the causes remain unknown. Here, we report that lysogenic phages can cause EAB decay in Geobacter sulfurreducens fuel cells. A cross-streak agar assay and bioinformatic analysis revealed the presence of prophages on the G. sulfurreducens genome, and a mitomycin C induction assay revealed the lysogenic to lytic transition of those prophages, resulting in a progressive decay in both current generation and the EAB. Furthermore, the addition of phages purified from decayed EAB resulted in accelerated decay of the EAB, thereafter contributing to a faster decline in current generation; otherwise, deleting prophage-related genes rescued the decay process. Our study provides the first evidence of an interaction between phages and electroactive bacteria and suggests that attack by phages is a primary cause of EAB decay, having significant implications in bioelectrochemical systems.}, }
@article {pmid36997801, year = {2023}, author = {Suchi, SA and Nam, KB and Kim, YK and Tarek, H and Yoo, JC}, title = {A novel antimicrobial peptide YS12 isolated from Bacillus velezensis CBSYS12 exerts anti-biofilm properties against drug-resistant bacteria.}, journal = {Bioprocess and biosystems engineering}, volume = {}, number = {}, pages = {}, pmid = {36997801}, issn = {1615-7605}, abstract = {Nowadays, the abuse of antibiotics has led to the rise of multi-drug-resistant bacteria. Antimicrobial peptides (AMPs), with broad-spectrum antimicrobial activity have attracted considerable attention as possible alternatives to traditional antibiotics. In this work, we aimed to evaluate the antimicrobial and anti-biofilm activity of an antimicrobial peptide designed as YS12 derived from Bacillus velezensis CBSYS12. The strain CBSYS12 was isolated from Korean food kimchi and purified followed by ultrafiltration and sequential chromatographic methodology. Hereafter, Tricine SDS-PAGE revealed a single protein band of around 3.3 kDa that was further confirmed in situ inhibitory activity of the gel. A similar molecular weight (~ 3348.4 Da) protein also appeared in MALDI-TOF confirming the purity and homogeneity of peptide YS12. Intriguingly, YS12 revealed a strong antimicrobial activity with a minimum inhibitory concentration (MIC) value ranging from 6 to 12 μg/ml for both Gram-positive and Gram-negative bacteria, such as E. coli, P. aeruginosa, MRSA 4-5, VRE 82, and M. smegmatis. We also determined the mode of action of the peptide against pathogenic microorganisms using different fluorescent dyes. In addition, the anti-biofilm assay demonstrated that peptide YS12 was able to inhibit biofilm formation around 80% for both bacterial strains E. coli and P. aeruginosa at 80 µg/ml. Notably, YS12 exhibited a greater biofilm eradication activity than commercial antibiotics. In summary, our study proposed that peptide YS12 may be used as a promising therapeutic agent to overcome drug and biofilm-related infections.}, }
@article {pmid36997145, year = {2023}, author = {Liu, Y and Wu, B and Cui, X and Ren, Q and Ren, T and Zhou, Y}, title = {Distribution and dynamics of antibiotic resistance genes in a three-dimensional multifunctional biofilm during greywater treatment.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {}, number = {}, pages = {121533}, doi = {10.1016/j.envpol.2023.121533}, pmid = {36997145}, issn = {1873-6424}, abstract = {Antibiotic resistance genes (ARGs) have been identified as serious threats to public health. Despite the widespread in various systems, dynamics of ARGs in three-dimensional multifunctional biofilm (3D-MFB) treating greywater are largely undefined. This work tracked the distributions and dynamics of eight target genes (intI1, korB, sul1, sul2, tetM, ermB, blaCTX-M and qnrS) in a 3D-MFB during greywater treatment. Results showed that hydraulic retention times at 9.0 h achieved the highest linear alkylbenzene sulfonate (LAS) and total nitrogen removal rates at 99.4% and 79.6%, respectively. ARGs presented significant liquid-solid distribution feature, but non-significant with biofilm position. Intracellular ARGs (predominant by intI1, korB, sul1 and sul2) at bottom biofilm were 210- to 4.2 × 10[4]- fold higher than that in cell-free liquid. Extracellular polymeric substances (EPS)-attached LAS showed linear relationship with most of ARGs (R[2] > 0.90, P < 0.05). Sphingobacteriales, Chlamydiales, Microthrixaceae, SB-1, Cryomorphaceae, Chitinophagaceae, Leadbetterella and Niabella were tightly bound up with target ARGs. Key is that EPS-attached LAS considerably determines the occurrence of ARGs, and microbial taxa play an important role in the dissemination of ARGs in the 3D-MFB.}, }
@article {pmid36996938, year = {2023}, author = {Asif, M and Alvi, IA and Waqas, M and Basit, A and Raza, FA and Rehman, SU}, title = {A K-17 serotype specific Klebsiella phage JKP2 with biofilm reduction potential.}, journal = {Virus research}, volume = {}, number = {}, pages = {199107}, doi = {10.1016/j.virusres.2023.199107}, pmid = {36996938}, issn = {1872-7492}, abstract = {Klebsiella pneumoniae is an opportunistic pathogen responsible for nearly one-third of all Gram-negative infections. Increasing antibiotic resistance has pushed scientists to look for alternative therapeutics. Bacteriophages have emerged as one of the promising alternatives. In the current study, the Klebsiella phage JKP2 was isolated from a sewage sample and characterized against the K-17 serotype of K. pneumoniae. It produced bulls-eye-shaped clear plaques and has a latent period of 45 minutes with a burst size of 70 pfu/cell. It remained stable at tested pH (5 to 10) and temperatures (37 to 60 °C). Its optimum temperature for long-term storage is 4 °C and -80 °C. The JKP2 showed its infectivity against the K. pneumoniae K-17 serotype only. It controlled planktonic cells of K. pneumoniae 12 hours post-incubation. At MOI-1, it efficiently eliminated 98% of 24 and 96% of 48-hour-old biofilm and 86% and 82% of mature biofilm of day 3 and 4, respectively. The JKP2 has an icosahedral capsid of 54 ± 0.5 nm with a short, non-contractile tail, measuring 12 ± 0.2 nm. It possesses a double-stranded DNA genome of 43.2 kbp with 54.1% GC content and encodes 54 proteins, including 29 with known functions and 25 with unknown functions. JKP2 was classified as Drulisvirus within the Autographiviridae family. It uses a T7-like direct terminal repeat strategy for genome packaging. JKP2 can be applied safely for therapeutic purposes as it does not encode an integrase or repressor genes, antibiotic resistance genes, bacterial virulence factors, and mycotoxins.}, }
@article {pmid36996693, year = {2023}, author = {Wan Omar, WH and Mahyudin, NA and Azmi, NN and Mahmud Ab Rashid, NK and Ismail, R and Mohd Yusoff, MHY and Khairil Mokhtar, NF and Sharples, GJ}, title = {Effect of natural antibacterial clays against single biofilm formation by Staphylococcus aureus and Salmonella Typhimurium bacteria on a stainless-steel surface.}, journal = {International journal of food microbiology}, volume = {394}, number = {}, pages = {110184}, doi = {10.1016/j.ijfoodmicro.2023.110184}, pmid = {36996693}, issn = {1879-3460}, abstract = {Staphylococcus aureus and Salmonella Typhimurium have a propensity to develop biofilms on food contact surfaces, such as stainless-steel, that persist despite rigorous cleaning and sanitizing procedures. Since both bacterial species pose a significant public health risk within the food chain, improved anti-biofilm measures are needed. This study examined the potential of clays as antibacterial and anti-biofilm agents against these two pathogens on appropriate contact surfaces. Natural soil was processed to yield leachates and suspensions of both untreated and treated clays. Soil particle size, pH, cation-exchange capacity, and metal ions were characterized to assess their importance in bacterial killing. Initial antibacterial screening was performed on nine distinct types of natural Malaysian soil using a disk diffusion assay. Untreated leachate from Kuala Gula and Kuala Kangsar clays were found to inhibit S. aureus (7.75 ± 0.25 mm) and Salmonella Typhimurium (11.85 ± 1.63 mm), respectively. The treated Kuala Gula suspension (50.0 and 25.0 %) reduced S. aureus biofilms by 4.4 and 4.2 log at 24 and 6 h, respectively, while treated Kuala Kangsar suspension (12.5 %) by a 4.16 log reduction at 6 h. Although less effective, the treated Kuala Gula leachate (50.0 %) was effective in removing Salmonella Typhimurium biofilm with a decrease of >3 log in 24 h. In contrast to Kuala Kangsar clays, the treated Kuala Gula clays contained a much higher soluble metal content, especially Al (301.05 ± 0.45 ppm), Fe (691.83 ± 4.80 ppm) and Mg (88.44 ± 0.47 ppm). Elimination of S. aureus biofilms correlated with the presence of Fe, Cu, Pb, Ni, Mn and Zn irrespective of the pH of the leachate. Our findings demonstrate that a treated suspension is the most effective for eradication of S. aureus biofilms with a potential as a sanitizer-tolerant, natural antibacterial against biofilms for applications in the food industry.}, }
@article {pmid36995927, year = {2023}, author = {Mayorga-Martinez, CC and Zelenka, J and Klima, K and Kubanova, M and Ruml, T and Pumera, M}, title = {Multimodal-Driven Magnetic Microrobots with Enhanced Bactericidal Activity for Biofilm Eradication and Removal from Titanium Mesh.}, journal = {Advanced materials (Deerfield Beach, Fla.)}, volume = {}, number = {}, pages = {e2300191}, doi = {10.1002/adma.202300191}, pmid = {36995927}, issn = {1521-4095}, abstract = {Modern micro/nanorobots can perform multiple tasks for biomedical and environmental applications. Particularly, magnetic microrobots can be completely controlled by a rotating magnetic field and their motion powered and controlled without the use of toxic fuels, which makes them most promising for biomedical application. Moreover, they are able to form swarms, allowing them to perform specific tasks at a larger scale than a single microrobot. In this work, we developed magnetic microrobots composed of halloysite nanotubes as backbone and Fe3 O4 nanoparticles as magnetic material allowing magnetic propulsion and covered these with polyethylenimine to load ampicillin and prevent the microrobots from disassembling. These microrobots exhibit multimodal motion as single robots as well as in swarms. In addition, they can transform from tumbling to spinning motion and vice-versa, and when in swarm mode they can change their motion from vortex to ribbon and back again. Finally, the vortex motion mode is used to penetrate and disrupt the extracellular matrix of Staphylococcus aureus biofilm colonized on titanium mesh used for bone restoration, which improves the effect of the antibiotic's activity. Such magnetic microrobots for biofilm removal from medical implants could reduce implant rejection and improve patients' well-being. This article is protected by copyright. All rights reserved.}, }
@article {pmid36995247, year = {2023}, author = {Ding, R and Ouyang, Z and Zhang, X and Dong, Y and Guo, X and Zhu, L}, title = {Biofilm-Colonized versus Virgin Black Microplastics to Accelerate the Photodegradation of Tetracycline in Aquatic Environments: Analysis of Underneath Mechanisms.}, journal = {Environmental science &amp; technology}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.est.3c00019}, pmid = {36995247}, issn = {1520-5851}, abstract = {Tire wear particles (TWPs) exposed to the aquatic environment are rapidly colonized by microorganisms and provide unique substrates for biofilm formation, which potentially serve as vectors for tetracycline (TC) to influence their behaviors and potential risks. To date, the photodegradation capacity of TWPs on contaminants due to biofilm formation has not been quantified. To accomplish this, we examined the ability of virgin TWPs (V-TWPs) and biofilm-developed TWPs (Bio-TWPs) to photodegrade TC when exposed to simulated sunlight irradiation. V-TWPs and Bio-TWPs accelerated the photodegradation of TC, with rates (kobs) of 0.0232 ± 0.0014 and 0.0152 ± 0.0010 h[-1], respectively (kobs increased by 2.5-3.7 times compared to that for only TC solution). An important factor of increased TC photodegradation behavior was identified and linked to the changed reactive oxygen species (ROS) of different TWPs. The V-TWPs were exposed to light for 48 h, resulting in more ROS for attacking TC, with hydroxyl radicals ([•]OH) and superoxide anions (O2[•-]) playing a dominant role in TC photodegradation measured using scavenger/probe chemicals. This was primarily due to the greater photosensitization effects and higher electron-transfer capacity of V-TWPs in comparison to Bio-TWPs. In addition, this study first sheds light on the unique effect and intrinsic mechanism of the crucial role of Bio-TWPs in TC photodegradation, enhancing our holistic understanding of the environmental behavior of TWPs and the associated contaminants.}, }
@article {pmid36994560, year = {2023}, author = {Jiang, M and Li, Y}, title = {[Advances in electrochemically active biofilm of Shewanella oneidensis MR-1].}, journal = {Sheng wu gong cheng xue bao = Chinese journal of biotechnology}, volume = {39}, number = {3}, pages = {881-897}, doi = {10.13345/j.cjb.220468}, pmid = {36994560}, issn = {1872-2075}, abstract = {Facing the increasingly severe energy shortage and environmental pollution, electrocatalytic processes using electroactive microorganisms provide a new alternative for achieving environmental-friendly production. Because of its unique respiratory mode and electron transfer ability, Shewanella oneidensis MR-1 has been widely used in the fields of microbial fuel cell, bioelectrosynthesis of value-added chemicals, metal waste treatment and environmental remediation system. The electrochemically active biofilm of S. oneidensis MR-1 is an excellent carrier for transferring the electrons of the electroactive microorganisms. The formation of electrochemically active biofilm is a dynamic and complex process, which is affected by many factors, such as electrode materials, culture conditions, strains and their metabolism. The electrochemically active biofilm plays a very important role in enhancing bacterial environmental stress resistance, improving nutrient uptake and electron transfer efficiency. This paper reviewed the formation process, influencing factors and applications of S. oneidensis MR-1 biofilm in bio-energy, bioremediation and biosensing, with the aim to facilitate and expand its further application.}, }
@article {pmid36993593, year = {2023}, author = {Hunt, BC and Brix, V and Vath, J and Gutterman, LB and Taddei, SM and Learman, BS and Brauer, AL and Armbruster, CE}, title = {Metabolic interplay between Proteus mirabilis and Enterococcus faecalis facilitates polymicrobial biofilm formation and invasive disease.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.03.17.533237}, pmid = {36993593}, abstract = {Catheter-associated urinary tract infections (CAUTI) account for 40% of all nosocomial infections and can lead to significant life-threatening complications such as bacteremia. Microbial biofilms play an important role in the development and pathogenesis of CAUTI, and these biofilms are often polymicrobial. Proteus mirabilis and Enterococcus faecalis are two of the most common causes of CAUTI, and they often persistently co-colonize the catheterized urinary tract. We previously demonstrated that co-culture of E. faecalis with P. mirabilis increased biofilm biomass, antimicrobial resistance, and disease severity. In this study, we uncover the metabolic interplay that drives biofilm enhancement and examine the contribution of this polymicrobial interaction to CAUTI severity. Though compositional and proteomic biofilm analyses, we determined that the increase in biofilm biomass stems from an increase in the protein fraction of the polymicrobial biofilm. We further observed an enrichment in proteins associated with ornithine and arginine metabolism in polymicrobial biofilms compared to single- species biofilms. By testing mutants of E. faecalis and P. mirabilis, we found that L-ornithine secreted by the E. faecalis ArcD antiporter promotes L-arginine biosynthesis in P. mirabilis via ArgF, which ultimately fuels production of proteins that facilitate contact-dependent interactions to enhance biofilm biomass. We further demonstrate that ArcD and ArgF are not important for urinary tract colonization by either species when alone, but ornithine/arginine interplay is critical for the increased disease severity that occurs during coinfection. This study provides deeper insight into the polymicrobial interactions occurring during CAUTI and highlights how these interactions can have significant impacts on pathogenesis and bacterial persistence.}, }
@article {pmid36992682, year = {2023}, author = {Hammouda, ZK and Wasfi, R and Abdeltawab, NF}, title = {Hormonal drugs: Influence on growth, biofilm formation, and adherence of selected gut microbiota.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1147585}, pmid = {36992682}, issn = {2235-2988}, abstract = {Many studies have reported the influence of hormonal drugs on gut microbiota composition. However, the underlying mechanism of this interaction is still under study. Therefore, this study aimed to evaluate the possible in vitro changes in selected members of gut bacteria exposed to oral hormonal drugs used for years. Selected members of gut bacteria were Bifidobacterium longum, Limosilactobacillus reuteri, Bacteroides fragilis, and Escherichia coli representing the four main phyla in the gut. Selected hormonal drugs used for a long time were estradiol, progesterone, and thyroxine. The effect of intestinal concentrations of these drugs on the selected bacterial growth, biofilm formation, and adherence to Caco-2/HT-29 cell line was assessed. Short-chain fatty acids (SCFAs) have been included in host functions including the gut, immune and nervous functions; thus, the drug's effects on their production were assayed using High- Performance Liquid Chromatography. Sex steroids significantly increased the growth of all tested bacteria except B. longum, similarly, thyroxine increased the growth of tested Gram-negative bacteria however reducing that of tested Gram-positive bacteria. The effect of drugs on biofilm formation and bacterial adherence to cell lines cocultures was variable. Progesterone decreased the biofilm formation of tested Gram-positive bacteria, it nevertheless increased L. reuteri adherence to Caco-2/HT-29 cell line cell lines coculture. By contrast, progesterone increased biofilm formation by Gram-negative bacteria and increased adherence of B. fragilis to the cell lines coculture. Moreover, thyroxine and estradiol exhibited antibiofilm activity against L. reuteri, while thyroxine increased the ability of E. coli to form a biofilm. Moreover, hormones affected bacterial adherence to cell lines independently of their effect on hydrophobicity suggesting other specific binding factors might contribute to this effect. Tested drugs affected SCFAs production variably, mostly independent of their effect on bacterial growth. In conclusion, our results showed that the microbiota signature associated with some hormonal drug consumption could be the result of the direct effect of these drugs on bacterial growth, and adherence to enterocytes besides the effect of these drugs on the host tissue targets. Additionally, these drugs affect the production of SCFAs which could contribute to some of the side effects of these drugs.}, }
@article {pmid36991258, year = {2023}, author = {Al-Momani, H and Al Balawi, D and Hamed, S and Albiss, BA and Almasri, M and AlGhawrie, H and Ibrahim, L and Al Balawi, H and Al Haj Mahmoud, S and Pearson, J and Ward, C}, title = {The impact of biosynthesized ZnO nanoparticles from Olea europaea (Common Olive) on Pseudomonas aeruginosa growth and biofilm formation.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {5096}, pmid = {36991258}, issn = {2045-2322}, abstract = {There is a limitation in the range of effectual antibiotics due to the Pseudomonas aeruginosa (PA) infection due to its innate antimicrobial resistance. Researchers have therefore been concentrating their efforts to discover advanced and cost effective antibacterial agents among the ever-increasing PA bacterial resistance strains. It has been discovered that various nanoparticles can be employed as antimicrobial agents. Here, we evaluated the antibacterial properties of the Zinc Oxide nanoparticles (ZnO NPs), which was biosynthesized, being examined on six hospital strains of PA alongside a reference strain (ATCC 27853). A chemical approach was applied to biosynthesize the ZnO NPs from Olea europaea was performed, and confirmed by using X-ray diffraction and Scanning Electron Microscopes. The nanoparticles then applied their antibacterial properties to examine them against six clinically isolated PA strains alongside the reference strain. This process tested for the results of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The Growth, biofilm formation and eradication were analyzed. The influence of the differentiating degrees ZnO NPs in regard to Quorom sensing gene expression were further examined. The ZnO NPs exhibited a crystalline size and diameter (Dc) of 40-60 nm and both the MIC and MBC tests revealed positive outcomes of concentrations of 3 and 6 mg/ml for each PA strain, respectively. At sub inhibitory concentration, The ZnO NPs were found to significantly inhibit the growth and biofilm formation of all PA strains and decreases in the biomass and metabolic behavior of PA established biofilms; these decreases varied depending on the dosage. At ZnO NPs concentrations of 900 µg/ml, the expression of majority of quorum sensing genes of all strains were significantly reduced, at ZnO NPs concentrations of 300 µg/ml, few genes were significantly impacted. In conclusion, the treatment of PA and could be other antibiotic resistant bacteria can therefore be approached by using ZnO NPs as it has been uncovered that they withhold advanced antibacterial properties.}, }
@article {pmid36989304, year = {2023}, author = {Lee, SH and Secchi, E and Kang, PK}, title = {Rapid formation of bioaggregates and morphology transition to biofilm streamers induced by pore-throat flows.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {14}, pages = {e2204466120}, doi = {10.1073/pnas.2204466120}, pmid = {36989304}, issn = {1091-6490}, abstract = {Bioaggregates are condensed porous materials comprising microbes, organic and inorganic matters, and water. They are commonly found in natural and engineered porous media and often cause clogging. Despite their importance, the formation mechanism of bioaggregates in porous media systems is largely unknown. Through microfluidic experiments and direct numerical simulations of fluid flow, we show that the rapid bioaggregation is driven by the interplay of the viscoelastic nature of biomass and hydrodynamic conditions at pore throats. At an early stage, unique flow structures around a pore throat promote the biomass attachment at the throat. Then, the attached biomass fluidizes when the shear stress at the partially clogged pore throat reaches a critical value. After the fluidization, the biomass is displaced and accumulated in the expansion region of throats forming bioaggregates. We further find that such criticality in shear stress triggers morphological changes in bioaggregates from rounded- to streamer-like shapes. This knowledge was used to control the clogging of throats by tuning the flow conditions: When the shear stress at the throat exceeded the critical value, clogging was prevented. The bioaggregation process did not depend on the detailed pore-throat geometry, as we reproduced the same dynamics in various pore-throat geometries. This study demonstrates that pore-throat structures, which are ubiquitous in porous media systems, induce bioaggregation and can lead to abrupt disruptions in flow.}, }
@article {pmid36988848, year = {2023}, author = {Maurya, KL and Swain, G and Kumar, M and Sonwani, RK and Verma, A and Singh, RS}, title = {Biodegradation of Congo Red Dye Using Lysinibacillus Species in a Moving Bed Biofilm Reactor: Continuous Study and Kinetic Evaluation.}, journal = {Applied biochemistry and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {36988848}, issn = {1559-0291}, abstract = {The objective of this work was to develop a low-cost and efficient biocarrier for biodegradation of azo dye (i.e., Congo red (CR) dye). The potential bacterial species, i.e., Lysinibacillus fusiformis KLM1 and Lysinibacillus macrolides KLM2, were isolated from the dye-contaminated site. These bacterial species were immobilized onto the polypropylene-polyurethane foam (PP-PUF) and employed in a moving bed biofilm reactor (MBBR) for the treatment of CR dye. The effectiveness of the MBBR was investigated by operating the bioreactor in a continuous mode at various initial CR dye concentrations (50-250 mg/L) for 113 days. The removal efficiency was found in the range of 88.4-64.6% when the initial dye concentration was varied from 50 to 250 mg/L. The maximum elimination capacity (EC) of 213.18 mg/L.d was found at 250 mg/L of CR dye concentration. In addition, the CR dye utilization rate in the MBBR was studied by using two kinetics, namely, first-order and second-order (Grau) models. The high regression coefficients (R[2] > 0.97) and the satisfactory root mean square (RMSE) values (0.00096-0.02610) indicated the reasonable prediction of CR dye degradation rate by the Grau model.}, }
@article {pmid36987290, year = {2023}, author = {Fan, Z and Zhou, X}, title = {Decoding the Role of Extracellular Polymeric Substances in Enhancing Nitrogen Removal from High-Ammonia and Low-C/N Wastewater in a Sequencing Batch Packed-Bed Biofilm Reactor.}, journal = {Polymers}, volume = {15}, number = {6}, pages = {}, pmid = {36987290}, issn = {2073-4360}, abstract = {Although the role of extracellular polymeric substances (EPSs) as a viscous high-molecular polymer in biological wastewater treatment has been recognized, in-depth knowledge of how EPSs affect nitrogen removal remains limited in biofilm-based reactors. Herein, we explored EPS characteristics associated with nitrogen removal from high-ammonia (NH4[+]-N: 300 mg/L) and low carbon-to-nitrogen ratio (C/N: 2-3) wastewater in a sequencing batch packed-bed biofilm reactor (SBPBBR) under four different operating scenarios for a total of 112 cycles. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier-transform infrared (FTIR) analysis revealed that the distinct physicochemical properties, interface microstructure, and chemical composition of the bio-carrier were conducive to biofilm formation and microbial immobilization and enrichment. Under the optimal conditions (C/N: 3, dissolved oxygen: 1.3 mg/L, and cycle time: 12 h), 88.9% ammonia removal efficiency (ARE) and 81.9% nitrogen removal efficiency (NRE) could be achieved in the SBPBBR. Based on visual and SEM observations of the bio-carriers, biofilm development, biomass concentration, and microbial morphology were closely linked with nitrogen removal performance. Moreover, FTIR and three-dimensional excitation-emission matrix (3D-EEM) spectroscopy demonstrated that tightly bound EPSs (TB-EPSs) play a more important role in maintaining the stability of the biofilm. Significant shifts in the number, intensity, and position of fluorescence peaks of EPSs determined different nitrogen removal. More importantly, the high presence of tryptophan proteins and humic acids might promote advanced nitrogen removal. These findings uncover intrinsic correlations between EPSs and nitrogen removal for better controlling and optimizing biofilm reactors.}, }
@article {pmid36987156, year = {2023}, author = {Cai, K and Liu, Y and Yue, Y and Liu, Y and Guo, F}, title = {Essential Oil Nanoemulsion Hydrogel with Anti-Biofilm Activity for the Treatment of Infected Wounds.}, journal = {Polymers}, volume = {15}, number = {6}, pages = {}, pmid = {36987156}, issn = {2073-4360}, abstract = {The formation of a bacterial biofilm on an infected wound can impede drug penetration and greatly thwart the healing process. Thus, it is essential to develop a wound dressing that can inhibit the growth of and remove biofilms, facilitating the healing of infected wounds. In this study, optimized eucalyptus essential oil nanoemulsions (EEO NEs) were prepared from eucalyptus essential oil, Tween 80, anhydrous ethanol, and water. Afterward, they were combined with a hydrogel matrix physically cross-linked with Carbomer 940 (CBM) and carboxymethyl chitosan (CMC) to prepare eucalyptus essential oil nanoemulsion hydrogels (CBM/CMC/EEO NE). The physical-chemical properties, in vitro bacterial inhibition, and biocompatibility of EEO NE and CBM/CMC/EEO NE were extensively investigated and the infected wound models were proposed to validate the in vivo therapeutic efficacy of CBM/CMC/EEO NE. The results showed that the average particle size of EEO NE was 15.34 ± 3.77 nm with PDI ˂ 0.2, the minimum inhibitory concentration (MIC) of EEO NE was 15 mg/mL, and the minimum bactericidal concentration (MBC) against S. aureus was 25 mg/mL. The inhibition and clearance of EEO NE against S. aureus biofilm at 2×MIC concentrations were 77.530 ± 7.292% and 60.700 ± 3.341%, respectively, demonstrating high anti-biofilm activity in vitro. CBM/CMC/EEO NE exhibited good rheology, water retention, porosity, water vapor permeability, and biocompatibility, meeting the requirements for trauma dressings. In vivo experiments revealed that CBM/CMC/EEO NE effectively promoted wound healing, reduced the bacterial load of wounds, and accelerated the recovery of epidermal and dermal tissue cells. Moreover, CBM/CMC/EEO NE significantly down-regulated the expression of two inflammatory factors, IL-6 and TNF-α, and up-regulated three growth-promoting factors, TGF-β1, VEGF, and EGF. Thus, the CBM/CMC/EEO NE hydrogel effectively treated wounds infected with S. aureus, enhancing the healing process. It is expected to be a new clinical alternative for healing infected wounds in the future.}, }
@article {pmid36987108, year = {2023}, author = {Adeosun, IJ and Baloyi, IT and Cosa, S}, title = {Correction: Adeosun et al. Anti-Biofilm and Associated Anti-Virulence Activities of Selected Phytochemical Compounds against Klebsiella pneumoniae. Plants 2022, 11, 1429.}, journal = {Plants (Basel, Switzerland)}, volume = {12}, number = {6}, pages = {}, doi = {10.3390/plants12061236}, pmid = {36987108}, issn = {2223-7747}, abstract = {In the original publication [...].}, }
@article {pmid36986869, year = {2023}, author = {Velázquez-Moreno, S and González-Amaro, AM and Aragón-Piña, A and López-López, LI and Sánchez-Sánchez, R and Pérez-Díaz, MA and Oliva Rodríguez, R and Lorenzo-Leal, AC and González-Ortega, O and Martinez-Gutierrez, F and Bach, H}, title = {Use of a Cellulase from Trichoderma reesei as an Adjuvant for Enterococcus faecalis Biofilm Disruption in Combination with Antibiotics as an Alternative Treatment in Secondary Endodontic Infection.}, journal = {Pharmaceutics}, volume = {15}, number = {3}, pages = {}, pmid = {36986869}, issn = {1999-4923}, abstract = {Apical periodontitis is an inflammation leading to the injury and destruction of periradicular tissues. It is a sequence of events that starts from root canal infection, endodontic treatment, caries, or other dental interventions. Enterococcus faecalis is a ubiquitous oral pathogen that is challenging to eradicate because of biofilm formation during tooth infection. This study evaluated a hydrolase (CEL) from the fungus Trichoderma reesei combined with amoxicillin/clavulanic acid as a treatment against a clinical E. faecalis strain. Electron microscopy was used to visualize the structure modification of the extracellular polymeric substances. Biofilms were developed on human dental apices using standardized bioreactors to evaluate the antibiofilm activity of the treatment. Calcein and ethidium homodimer assays were used to evaluate the cytotoxic activity in human fibroblasts. In contrast, the human-derived monocytic cell line (THP-1) was used to evaluate the immunological response of CEL. In addition, the secretion of the pro-inflammatory cytokines IL-6 and TNF-α and the anti-inflammatory cytokine IL-10 were measured by ELISA. The results demonstrated that CEL did not induce the secretion of IL-6 and TNF-α when compared with lipopolysaccharide used as a positive control. Furthermore, the treatment combining CEL with amoxicillin/clavulanic acid showed excellent antibiofilm activity, with a 91.4% reduction in CFU on apical biofilms and a 97.6% reduction in the microcolonies. The results of this study could be used to develop a treatment to help eradicate persistent E. faecalis in apical periodontitis.}, }
@article {pmid36986852, year = {2023}, author = {Fathil, MAM and Katas, H}, title = {Antibacterial, Anti-Biofilm and Pro-Migratory Effects of Double Layered Hydrogels Packaged with Lactoferrin-DsiRNA-Silver Nanoparticles for Chronic Wound Therapy.}, journal = {Pharmaceutics}, volume = {15}, number = {3}, pages = {}, doi = {10.3390/pharmaceutics15030991}, pmid = {36986852}, issn = {1999-4923}, abstract = {Antimicrobial resistance and biofilm formation in diabetic foot infections worsened during the COVID-19 pandemic, resulting in more severe infections and increased amputations. Therefore, this study aimed to develop a dressing that could effectively aid in the wound healing process and prevent bacterial infections by exerting both antibacterial and anti-biofilm effects. Silver nanoparticles (AgNPs) and lactoferrin (LTF) have been investigated as alternative antimicrobial and anti-biofilm agents, respectively, while dicer-substrate short interfering RNA (DsiRNA) has also been studied for its wound healing effect in diabetic wounds. In this study, AgNPs were complexed with LTF and DsiRNA via simple complexation before packaging in gelatin hydrogels. The formed hydrogels exhibited 1668% maximum swellability, with a 46.67 ± 10.33 µm average pore size. The hydrogels demonstrated positive antibacterial and anti-biofilm effects toward the selected Gram-positive and Gram-negative bacteria. The hydrogel containing AgLTF at 125 µg/mL was also non-cytotoxic on HaCaT cells for up to 72 h of incubation. The hydrogels containing DsiRNA and LTF demonstrated superior pro-migratory effects compared to the control group. In conclusion, the AgLTF-DsiRNA-loaded hydrogel possessed antibacterial, anti-biofilm, and pro-migratory activities. These findings provide a further understanding and knowledge on forming multipronged AgNPs consisting of DsiRNA and LTF for chronic wound therapy.}, }
@article {pmid36985403, year = {2023}, author = {Liu, X and Yao, H and Zhao, X and Ge, C}, title = {Biofilm Formation and Control of Foodborne Pathogenic Bacteria.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {6}, pages = {}, doi = {10.3390/molecules28062432}, pmid = {36985403}, issn = {1420-3049}, abstract = {Biofilms are microbial aggregation membranes that are formed when microorganisms attach to the surfaces of living or nonliving things. Importantly, biofilm properties provide microorganisms with protection against environmental pressures and enhance their resistance to antimicrobial agents, contributing to microbial persistence and toxicity. Thus, bacterial biofilm formation is part of the bacterial survival mechanism. However, if foodborne pathogens form biofilms, the risk of foodborne disease infections can be greatly exacerbated, which can cause major public health risks and lead to adverse economic consequences. Therefore, research on biofilms and their removal strategies are very important in the food industry. Food waste due to spoilage within the food industry remains a global challenge to environmental sustainability and the security of food supplies. This review describes bacterial biofilm formation, elaborates on the problem associated with biofilms in the food industry, enumerates several kinds of common foodborne pathogens in biofilms, summarizes the current strategies used to eliminate or control harmful bacterial biofilm formation, introduces the current and emerging control strategies, and emphasizes future development prospects with respect to bacterial biofilms.}, }
@article {pmid36985334, year = {2023}, author = {Richter, AM and Konrat, K and Osland, AM and Brook, E and Oastler, C and Vestby, LK and Gosling, RJ and Nesse, LL and Arvand, M}, title = {Evaluation of Biofilm Cultivation Models for Efficacy Testing of Disinfectants against Salmonella Typhimurium Biofilms.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030761}, pmid = {36985334}, issn = {2076-2607}, abstract = {Within the European Union, Salmonella is frequently reported in food and feed products. A major route of transmission is upon contact with contaminated surfaces. In nature, bacteria such as Salmonella are often encountered in biofilms, where they are protected against antibiotics and disinfectants. Therefore, the removal and inactivation of biofilms is essential to ensure hygienic conditions. Currently, recommendations for disinfectant usage are based on results of efficacy testing against planktonic bacteria. There are no biofilm-specific standards for the efficacy testing of disinfectants against Salmonella. Here, we assessed three models for disinfectant efficacy testing on Salmonella Typhimurium biofilms. Achievable bacterial counts per biofilm, repeatability, and intra-laboratory reproducibility were analyzed. Biofilms of two Salmonella strains were grown on different surfaces and treated with glutaraldehyde or peracetic acid. Disinfectant efficacy was compared with results for planktonic Salmonella. All methods resulted in highly repeatable cell numbers per biofilm, with one assay showing variations of less than 1 log10 CFU in all experiments for both strains tested. Disinfectant concentrations required to inactivate biofilms were higher compared to planktonic cells. Differences were found between the biofilm methods regarding maximal achievable cell numbers, repeatability, and intra-laboratory reproducibility of results, which may be used to identify the most appropriate method in relation to application context. Developing a standardized protocol for testing disinfectant efficacy on biofilms will help identify conditions that are effective against biofilms.}, }
@article {pmid36985206, year = {2023}, author = {da Silva, AA and Galego, L and Arraiano, CM}, title = {New Perspectives on BolA: A Still Mysterious Protein Connecting Morphogenesis, Biofilm Production, Virulence, Iron Metabolism, and Stress Survival.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030632}, pmid = {36985206}, issn = {2076-2607}, abstract = {The BolA-like protein family is widespread among prokaryotes and eukaryotes. BolA was originally described in E. coli as a gene induced in the stationary phase and in stress conditions. The BolA overexpression makes cells spherical. It was characterized as a transcription factor modulating cellular processes such as cell permeability, biofilm production, motility, and flagella assembly. BolA is important in the switch between motile and sedentary lifestyles having connections with the signaling molecule c-di-GMP. BolA was considered a virulence factor in pathogens such as Salmonella Typhimurium and Klebsiella pneumoniae and it promotes bacterial survival when facing stresses due to host defenses. In E. coli, the BolA homologue IbaG is associated with resistance to acidic stress, and in Vibrio cholerae, IbaG is important for animal cell colonization. Recently, it was demonstrated that BolA is phosphorylated and this modification is important for the stability/turnover of BolA and its activity as a transcription factor. The results indicate that there is a physical interaction between BolA-like proteins and the CGFS-type Grx proteins during the biogenesis of Fe-S clusters, iron trafficking and storage. We also review recent progress regarding the cellular and molecular mechanisms by which BolA/Grx protein complexes are involved in the regulation of iron homeostasis in eukaryotes and prokaryotes.}, }
@article {pmid36985196, year = {2023}, author = {Marra, D and Perna, I and Pota, G and Vitiello, G and Pezzella, A and Toscano, G and Luciani, G and Caserta, S}, title = {Nanoparticle Coatings on Glass Surfaces to Prevent Pseudomonas fluorescens AR 11 Biofilm Formation.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030621}, pmid = {36985196}, issn = {2076-2607}, abstract = {Microbial colonization of surfaces is a sanitary and industrial issue for many applications, leading to product contamination and human infections. When microorganisms closely interact with a surface, they start to produce an exo-polysaccaridic matrix to adhere to and protect themselves from adverse environmental conditions. This type of structure is called a biofilm. The aim of our work is to investigate novel technologies able to prevent biofilm formation by surface coatings. We coated glass surfaces with melanin-ZnO2, melanin-TiO2, and TiO2 hybrid nanoparticles. The functionalization was performed using cold plasma to activate glass-substrate-coated surfaces, that were characterized by performing water and soybean oil wetting tests. A quantitative characterization of the antibiofilm properties was done using Pseudomonas fluorescens AR 11 as a model organism. Biofilm morphologies were observed using confocal laser scanning microscopy and image analysis techniques were used to obtain quantitative morphological parameters. The results highlight the efficacy of the proposed surface coating to prevent biofilm formation. Melanin-TiO2 proved to be the most efficient among the particles investigated. Our results can be a valuable support for future implementation of the technique proposed here in an extended range of applications that may include further testing on other strains and other support materials.}, }
@article {pmid36985130, year = {2023}, author = {Rühl-Teichner, J and Jacobmeyer, L and Leidner, U and Semmler, T and Ewers, C}, title = {Genomic Diversity, Antimicrobial Susceptibility, and Biofilm Formation of Clinical Acinetobacter baumannii Isolates from Horses.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030556}, pmid = {36985130}, issn = {2076-2607}, abstract = {Acinetobacter (A.) baumannii is an opportunistic pathogen that causes severe infections in humans and animals, including horses. The occurrence of dominant international clones (ICs), frequent multidrug resistance, and the capability to form biofilms are considered major factors in the successful spread of A. baumannii in human and veterinary clinical environments. Since little is known about A. baumannii isolates from horses, we studied 78 equine A. baumannii isolates obtained from clinical samples between 2008 and 2020 for their antimicrobial resistance (AMR), clonal distribution, biofilm-associated genes (BAGs), and biofilm-forming capability. Based on whole-genome sequence analyses, ICs, multilocus (ML) and core-genome ML sequence types (STs), and AMR genes were determined. Antimicrobial susceptibility testing was performed by microbroth dilution. A crystal violet assay was used for biofilm quantification. Almost 37.2% of the isolates were assigned to IC1 (10.3%), IC2 (20.5%), and IC3 (6.4%). Overall, the isolates revealed high genomic diversity. We identified 51 different STs, including 22 novel STs (ST1723-ST1744), and 34 variants of the intrinsic oxacillinase (OXA), including 8 novel variants (OXA-970 to OXA-977). All isolates were resistant to ampicillin, amoxicillin/clavulanic acid, cephalexin, cefpodoxime, and nitrofurantoin. IC1-IC3 isolates were also resistant to gentamicin, enrofloxacin, marbofloxacin, tetracycline, and trimethoprim/sulfamethoxazole. All isolates were susceptible to imipenem. Thirty-one multidrug-resistant (MDR) isolates mainly accumulated in the IC1-IC3 groups. In general, these isolates showed less biofilm formation (IC1 = 25.0%, IC2 = 18.4%, IC3 = 15.0%) than the group of non-IC1-IC3 isolates (58.4%). Isolates belonging to the same ICs/STs revealed identical BAG patterns. BAG blp1 was absent in all isolates, whereas bfmR and pgaA were present in all isolates. At the level of the IC groups, the AMR status was negatively correlated with the isolates' ability to form a biofilm. A considerable portion of equine A. baumannii isolates revealed ICs/STs that are globally present in humans. Both an MDR phenotype and the capability to form biofilms might lead to therapeutic failures in equine medicine, particularly due to the limited availability of licensed drugs.}, }
@article {pmid36985119, year = {2023}, author = {Ioannidis, A and Chatzipanagiotou, S and Vassilaki, N and Giannakopoulos, P and Hatzaki, D and Magana, M and Sachlas, A and Mpekoulis, G and Radiotis, A and Tsakanikos, M and Tzanakaki, G and Lebessi, E and Tsolia, MN}, title = {Biofilm-Forming Bacteria Implicated in Complex Otitis Media in Children in the Post-Heptavalent Pneumococcal Conjugate Vaccine (PCV7) Era.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030545}, pmid = {36985119}, issn = {2076-2607}, abstract = {Background: Chronic media with effusion (COME) and recurrent acute otitis media (RAOM) are closely related clinical entities that affect childhood. The aims of the study were to investigate the microbiological profile of otitis-prone children in the post-PCV7 era and, to examine the biofilm-forming ability in association with clinical history and outcome during a two-year post-operative follow-up. Methods: In this prospective study, pathogens from patients with COME and RAOM were isolated and studied in vitro for their biofilm-forming ability. The minimum inhibitory concentrations (MIC) of both the planktonic and the sessile forms were compared. The outcome of the therapeutic method used in each case and patient history were correlated with the pathogens and their ability to form biofilms. Results: Haemophilus influenzae was the leading pathogen (35% in COME and 40% in RAOM), and Streptococcus pneumoniae ranked second (12% in COME and 24% in RAOM). Polymicrobial infections were identified in 5% of COME and 19% of RAOM cases. Of the isolated otopathogens, 94% were positive for biofilm formation. Conclusions: This is the first Greek research studying biofilm formation in complex otitis media-prone children population in the post-PCV7 era. High rates of polymicrobial infections, along with treatment failure in biofilms, may explain the lack of antimicrobial efficacy in otitis-prone children.}, }
@article {pmid36984711, year = {2023}, author = {Li, S and Duan, L and Zhao, Y and Gao, F and Hermanowicz, SW}, title = {Analysis of Microbial Communities in Membrane Biofilm Reactors Using a High-Density Microarray.}, journal = {Membranes}, volume = {13}, number = {3}, pages = {}, doi = {10.3390/membranes13030324}, pmid = {36984711}, issn = {2077-0375}, abstract = {Membrane biofilm reactors (MBfRs) have attracted more and more attention in the field of wastewater treatment due to their advantages of high mass transfer efficiency and low-carbon emissions. There are many factors affecting their nitrogen removal abilities, such as operation time, electron donor types, and operation modes. The operation time is directly related to the growth status of microorganisms, so it is very important to understand the effect of different operation times on microbial composition and community succession. In this study, two parallel H2-based MBfRs were operated, and differences in microbial composition, community succession, and NO3[-]-N removal efficiency were investigated on the 30th day and the 60th day of operation. The nitrogen removal efficiency of MBfRs with an operation time of 60 days was higher than that of MBfRs with an operation time of 30 days. Proteobacteria was the dominant phylum in both MBfRs; however, the composition of the microbial community was quite different. At the class level, the community composition of Proteobacteria was similar between the two MBfRs. Alphaproteobacteria was the dominant class in MBfR, and Betaproteobacteria and Gammaproteobacteria were also in high proportion. Combined with the analysis of microbial relative abundance and concentration, the similarity of microbial distribution in the MBfRs was very low on day 30 and day 60, and the phylogenetic relationships of the top 50 dominant universal bacteria and Proteobacteria were different. Although the microbial concentration decreased with the extension of the operation time, the microbial abundance and diversity of specific functional microorganisms increased further. Therefore, the operation time had a significant effect on microbial composition and community succession.}, }
@article {pmid36983858, year = {2023}, author = {Alenazy, R}, title = {Antimicrobial Activities and Biofilm Inhibition Properties of Trigonella foenumgraecum Methanol Extracts against Multidrug-Resistant Staphylococcus aureus and Escherichia coli.}, journal = {Life (Basel, Switzerland)}, volume = {13}, number = {3}, pages = {}, doi = {10.3390/life13030703}, pmid = {36983858}, issn = {2075-1729}, abstract = {Multidrug-resistant bacteria are becoming the leading cause of death globally due to their resistance to many currently used antibiotics. Bacteria naturally have intrinsic resistance or acquired resistance to certain commonly used antibiotics. Therefore, searching for novel compounds has become necessary. Trigonella foenumgraecum extract was evaluated for antimicrobial and antibiofilm activities against multidrug-resistant bacteria Staphylococcus aureus and Escherichia coli. The minimum inhibitory concentration and minimum bactericidal concentration of the extract were also determined. Moreover, gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the phytochemical components present in the extract. GC-MS analysis revealed that T. foenumgraecum extract contains major compounds such as Phenol, 2-methoxy-3-(2-propenyl)-, n-Hexadecanoic acid, and 9,12,15-Octadecatrienoic acid. Both bacterial strains showed resistance to some of the antibiotics tested. T. foenumgraecum showed inhibitory activity against the tested bacterial strains with a MIC of 500 µg/mL and MBC of 1000 µg/mL. The methanol extract decreased the biofilm activity of both E. coli and S. aureus below the sub-minimum inhibitory concentration. The extract showed antibacterial and antibiofilm activity against the tested bacterial pathogens.}, }
@article {pmid36983523, year = {2023}, author = {Maione, A and Imparato, M and Buonanno, A and Carraturo, F and Schettino, A and Schettino, MT and Galdiero, M and de Alteriis, E and Guida, M and Galdiero, E}, title = {Anti-Biofilm Activity of Phenyllactic Acid against Clinical Isolates of Fluconazole-Resistant Candida albicans.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {3}, pages = {}, doi = {10.3390/jof9030355}, pmid = {36983523}, issn = {2309-608X}, abstract = {Commonly found colonizing the human microbiota, Candida albicans is a microorganism known for its ability to cause infections, mainly in the vulvovaginal region, and is responsible for 85% to 90% of vulvovaginal candidiasis (VVC) cases. The development of drug resistance in C. albicans isolates after long-term therapy with fluconazole is an important complication to solve and new therapeutic strategies are required to target this organism and its pathogenicity. In the present study, phenyllactic acid (PLA) an important broad-spectrum antimicrobial compound was investigated for its antifungal and antivirulence activities against clinical isolates of C. albicans. Previously characterized strains of C. albicans isolates from women with VVC and C. albicans ATCC90028 were used to evaluate the antimicrobial and time dependent killing assay activity of PLA showing a MIC 7.5 mg mL[-1] and a complete reduction of viable Candida cells detected by killing kinetics after 4 h of treatment with PLA. Additionally, PLA significantly reduced the biomass and the metabolic activity of C. albicans biofilms and impaired biofilm formation also with changes in ERG11, ALS3, and HWP1 genes expression as detected by qPCR. PLA eradicated pre-formed biofilms as showed also with confocal laser scanning microscopy (CLSM) observations. Furthermore, the compound prolonged the survival rate of Galleria mellonella infected by C. albicans isolates. These results indicate that PLA is a promising candidate as novel and safe antifungal agents for the treatment of vulvovaginal candidiasis.}, }
@article {pmid36982399, year = {2023}, author = {Li, Y and Chen, X and Xu, X and Yu, C and Liu, Y and Jiang, N and Li, J and Luo, L}, title = {Deletion of pbpC Enhances Bacterial Pathogenicity on Tomato by Affecting Biofilm Formation, Exopolysaccharides Production, and Exoenzyme Activities in Clavibacter michiganensis.}, journal = {International journal of molecular sciences}, volume = {24}, number = {6}, pages = {}, doi = {10.3390/ijms24065324}, pmid = {36982399}, issn = {1422-0067}, abstract = {Penicillin-binding proteins (PBPs) are considered essential for bacterial peptidoglycan biosynthesis and cell wall assembly. Clavibacter michiganensis is a representative Gram-positive bacterial species that causes bacterial canker in tomato. pbpC plays a significant role in maintaining cell morphological characteristics and stress responses in C. michiganensis. The current study demonstrated that the deletion of pbpC commonly enhances bacterial pathogenicity in C. michiganensis and revealed the mechanisms through which this occurs. The expression of interrelated virulence genes, including celA, xysA, xysB, and pelA, were significantly upregulated in △pbpC mutants. Compared with those in wild-type strains, exoenzyme activities, the formation of biofilm, and the production of exopolysaccharides (EPS) were significantly increased in △pbpC mutants. It is noteworthy that EPS were responsible for the enhancement in bacterial pathogenicity, with the degree of necrotic tomato stem cankers intensifying with the injection of a gradient of EPS from C. michiganensis. These findings highlight new insights into the role of pbpC affecting bacterial pathogenicity, with an emphasis on EPS, advancing the current understanding of phytopathogenic infection strategies for Gram-positive bacteria.}, }
@article {pmid36982293, year = {2023}, author = {François, P and Schrenzel, J and Götz, F}, title = {Biology and Regulation of Staphylococcal Biofilm.}, journal = {International journal of molecular sciences}, volume = {24}, number = {6}, pages = {}, doi = {10.3390/ijms24065218}, pmid = {36982293}, issn = {1422-0067}, abstract = {Despite continuing progress in medical and surgical procedures, staphylococci remain the major Gram-positive bacterial pathogens that cause a wide spectrum of diseases, especially in patients requiring the utilization of indwelling catheters and prosthetic devices implanted temporarily or for prolonged periods of time. Within the genus, if Staphylococcus aureus and S. epidermidis are prevalent species responsible for infections, several coagulase-negative species which are normal components of our microflora also constitute opportunistic pathogens that are able to infect patients. In such a clinical context, staphylococci producing biofilms show an increased resistance to antimicrobials and host immune defenses. Although the biochemical composition of the biofilm matrix has been extensively studied, the regulation of biofilm formation and the factors contributing to its stability and release are currently still being discovered. This review presents and discusses the composition and some regulation elements of biofilm development and describes its clinical importance. Finally, we summarize the numerous and various recent studies that address attempts to destroy an already-formed biofilm within the clinical context as a potential therapeutic strategy to avoid the removal of infected implant material, a critical event for patient convenience and health care costs.}, }
@article {pmid36981945, year = {2023}, author = {Lopez-Gigosos, RM and Mariscal-Lopez, E and Gutierrez-Bedmar, M and Mariscal, A}, title = {Effect of Long-Term Use of Alcohol-Containing Handwashing Gels on the Biofilm-Forming Capacity of Staphylococcus epidermidis.}, journal = {International journal of environmental research and public health}, volume = {20}, number = {6}, pages = {}, doi = {10.3390/ijerph20065037}, pmid = {36981945}, issn = {1660-4601}, abstract = {The spread of coronavirus disease 2019 (COVID-19) has promoted the use of hand sanitizers among the general population as recommended by health authorities. Alcohols, which are used in many hand sanitizers, have been shown to promotes the formation of biofilms by certain bacteria and to increase bacterial resistance to disinfection. We investigated the effect of continued use of alcohol-based gel hand sanitizer on biofilm formation by the Staphylococcus epidermidis resident strain isolated from the hands of health science students. Hand microbes were counted before and after handwashing, and the ability to produce biofilms was investigated. We found that 179 (84.8%) strains of S. epidermidis isolated from hands had the ability to form biofilm (biofilm-positive strains) in an alcohol-free culture medium. Furthermore, the presence of alcohol in the culture medium induced biofilm formation in 13 (40.6%) of the biofilm-negative strains and increased biofilm production in 111 (76.6%) strains, which were classified as low-grade biofilm-producing. Based on our findings, there is no clear evidence that the continued use of alcohol-based gels results in the selection of strains with the capacity to form biofilms. However, other disinfectant formulations that are more commonly used in clinical settings, such as alcohol-based hand-rub solutions, should be tested for their long-term effects.}, }
@article {pmid36979940, year = {2023}, author = {Shahab, M and Danial, M and Khan, T and Liang, C and Duan, X and Wang, D and Gao, H and Zheng, G}, title = {In Silico Identification of Lead Compounds for Pseudomonas Aeruginosa PqsA Enzyme: Computational Study to Block Biofilm Formation.}, journal = {Biomedicines}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/biomedicines11030961}, pmid = {36979940}, issn = {2227-9059}, abstract = {Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium implicated in acute and chronic nosocomial infections and a leading cause of patient mortality. Pseudomonas aeruginosa infections are frequently associated with the development of biofilms, which give the bacteria additional drug resistance and increase their virulence. The goal of this study was to find strong compounds that block the Anthranilate-CoA ligase enzyme made by the pqsA gene. This would stop the P. aeruginosa quorum signaling system. This enzyme plays a crucial role in the pathogenicity of P. aeruginosa by producing autoinducers for cell-to-cell communication that lead to the production of biofilms. Pharmacophore-based virtual screening was carried out utilizing a library of commercially accessible enzyme inhibitors. The most promising hits obtained during virtual screening were put through molecular docking with the help of MOE. The virtual screening yielded 7/160 and 10/249 hits (ZINC and Chembridge). Finally, 2/7 ZINC hits and 2/10 ChemBridge hits were selected as potent lead compounds employing diverse scaffolds due to their high pqsA enzyme binding affinity. The results of the pharmacophore-based virtual screening were subsequently verified using a molecular dynamic simulation-based study (MDS). Using MDS and post-MDS, the stability of the complexes was evaluated. The most promising lead compounds exhibited a high binding affinity towards protein-binding pocket and interacted with the catalytic dyad. At least one of the scaffolds selected will possibly prove useful for future research. However, further scientific confirmation in the form of preclinical and clinical research is required before implementation.}, }
@article {pmid36979838, year = {2023}, author = {Zanetta, P and Squarzanti, DF and di Coste, A and Amoruso, A and Pane, M and Azzimonti, B}, title = {Growth Conditions Influence Lactobacillus Cell-Free Supernatant Impact on Viability, Biofilm Formation, and Co-Aggregation of the Oral Periodontopathogens Fusobacterium nucleatum and Porphyromonas gingivalis.}, journal = {Biomedicines}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/biomedicines11030859}, pmid = {36979838}, issn = {2227-9059}, abstract = {Fusobacterium nucleatum and Porphyromonas gingivalis human periodontopathogens play a leading part in oral squamous cell carcinoma through cell proliferation, invasion, and persistent inflammation promotion and maintenance. To explore how the activity of Lactobacillus-derived cell-free supernatants (CFSs) can be influenced by growth medium components, CFSs were produced both in the standard MRS and the novel animal-derivative-free "Terreno Industriale Lattobacilli" (TIL) media, and in vitro screened for the containment of F. nucleatum and P. gingivalis both single and co-cultured and also for the interference on their co-aggregation. The viability assay demonstrated that the Limosilactobacillus reuteri LRE11 and Ligilactobacillus salivarius LS03 MRS-produced CFSs were significantly more effective against single and co-cultured pathogens. All the other CFSs significantly improved their efficacy when produced in TIL. Both MRS- and TIL-produced CFSs significantly inhibited the single and co-cultured pathogen biofilm formation. Only Levilactobacillus brevis LBR01 CFS in MRS specifically reduced F. nucleatum and P. gingivalis co-aggregation, while viable LBR01, LS03, and LRE11 in MRS significantly co-aggregated with the pathogens, but only LS03 cultivated in TIL improved this effect. This work paves the way to better consider environmental growth conditions when screening for probiotic and postbiotic efficacy as crucial to pathogen aggregation, adhesion to the host's niches, and exclusion.}, }
@article {pmid36979113, year = {2023}, author = {El-Hossary, D and Mahdy, A and Elariny, EYT and Askora, A and Merwad, AMA and Saber, T and Dahshan, H and Hakami, NY and Ibrahim, RA}, title = {Antibiotic Resistance, Virulence Gene Detection, and Biofilm Formation in Aeromonas spp. Isolated from Fish and Humans in Egypt.}, journal = {Biology}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/biology12030421}, pmid = {36979113}, issn = {2079-7737}, abstract = {The genus Aeromonas is widely distributed in aquatic environments and is recognized as a potential human pathogen. Some Aeromonas species are able to cause a wide spectrum of diseases, mainly gastroenteritis, skin and soft-tissue infections, bacteremia, and sepsis. The aim of the current study was to determine the prevalence of Aeromonas spp. in raw fish markets and humans in Zagazig, Egypt; identify the factors that contribute to virulence; determine the isolates' profile of antibiotic resistance; and to elucidate the ability of Aeromonas spp. to form biofilms. The examined samples included fish tissues and organs from tilapia (Oreochromis niloticus, n = 160) and mugil (Mugil cephalus, n = 105), and human skin swabs (n = 51) and fecal samples (n = 27). Based on biochemical and PCR assays, 11 isolates (3.2%) were confirmed as Aeromonas spp. and four isolates (1.2%) were confirmed as A. hydrophila. The virulence genes including haemolysin (hyl A) and aerolysin (aer) were detected using PCR in A. hydrophila in percentages of 25% and 50%, respectively. The antimicrobial resistance of Aeromonas spp. was assessed against 14 antibiotics comprising six classes. The resistance to cefixime (81.8%) and tobramycin (45.4%) was observed. The multiple antibiotic resistance (MAR) index ranged between 0.142-0.642 with 64.2% of the isolates having MAR values equal to 0.642. Biofilm formation capacity was assessed using a microtiter plate assay, and two isolates (18.1%) were classified as biofilm producers. This study establishes a baseline for monitoring and controlling the multidrug-resistant Aeromonas spp. and especially A. hydrophila in marine foods consumed in our country to protect humans and animals.}, }
@article {pmid36978493, year = {2023}, author = {Akinduti, PA and George, OW and Ohore, HU and Ariyo, OE and Popoola, ST and Adeleye, AI and Akinwande, KS and Popoola, JO and Rotimi, SO and Olufemi, FO and Omonhinmin, CA and Olasehinde, GI}, title = {Evaluation of Efflux-Mediated Resistance and Biofilm formation in Virulent Pseudomonas aeruginosa Associated with Healthcare Infections.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030626}, pmid = {36978493}, issn = {2079-6382}, abstract = {Pseudomonas aeruginosa is a significant pathogen identified with healthcare-associated infections. The present study evaluates the role of biofilm and efflux pump activities in influencing high-level resistance in virulent P. aeruginosa strains in clinical infection. Phenotypic resistance in biotyped Pseudomonas aeruginosa (n = 147) from diagnosed disease conditions was classified based on multiple antibiotic resistance (MAR) indices and analysed with logistic regression for risk factors. Efflux pump activity, biofilm formation, and virulence factors were analysed for optimal association in Pseudomonas infection using receiver operation characteristics (ROC). Age-specificity (OR [CI] = 0.986 [0.946-1.027]), gender (OR [CI] = 1.44 [0.211-9.827]) and infection sources (OR [CI] = 0.860 [0.438-1.688]) were risk variables for multidrug resistance (MDR)-P. aeruginosa infection (p < 0.05). Biofilm formers caused 48.2% and 18.5% otorrhea and wound infections (95% CI = 0.820-1.032; p = 0.001) respectively and more than 30% multidrug resistance (MDR) strains demonstrated high-level efflux pump activity (95% CI = 0.762-1.016; p = 0.001), protease (95% CI = 0.112-0.480; p = 0.003), lipase (95% CI = 0.143-0.523; p = 0.001), and hemolysin (95% CI = 1.109-1.780; p = 0.001). Resistance relatedness of more than 80% and 60% to cell wall biosynthesis inhibitors (ceftazidime, ceffproxil, augumentin, ampicillin) and, DNA translational and transcriptional inhibitors (gentamicin, ciprofloxacin, ofloxacin, nitrofurantoin) were observed (p < 0.05). Strong efflux correlation (r = 0.85, p = 0.034) with MDR strains, with high predictive performances in efflux pump activity (ROC-AUC 0.78), biofilm formation (ROC-AUC 0.520), and virulence hierarchical-clustering. Combine activities of the expressed efflux pump and biofilm formation in MDR-P. aeruginosa pose risk to clinical management and infection control.}, }
@article {pmid36978490, year = {2023}, author = {Rajapaksha, DC and Edirisinghe, SL and Nikapitiya, C and Whang, I and De Zoysa, M}, title = {The Antimicrobial Peptide Octopromycin Suppresses Biofilm Formation and Quorum Sensing in Acinetobacter baumannii.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030623}, pmid = {36978490}, issn = {2079-6382}, abstract = {Acinetobacter baumannii is an opportunistic bacterial pathogen that causes severe infections in immunocompromised individuals. A. baumannii forms biofilm and produces extracellular matrix, which supports bacteria to survive under harsh conditions and be resistant to antibacterial treatments. In the present study, we investigated the biofilm and quorum-sensing inhibitory effects of antimicrobial peptide, octopromycin in A. baumannii. Field emission-scanning electron microscopy results clearly showed significantly reduced biofilm mass and caused a collapse in biofilm architecture at the minimum inhibitory concentration (50 µg/mL) and minimum bactericidal concentration (200 µg/mL) of octopromycin. Antibiotic-resistant persister cells of A. baumannii were successfully killed by octopromycin treatment, and it inhibited violacein production in Chromobacterium violaceum in a concentration-dependent manner. Octopromycin also inhibited alginate production, surface movements (swarming and swimming), and twitching motility of A. baumannnii, confirming its anti-quorum-sensing activity. Multiple metabolic pathways, two-component regulation systems, quorum-sensing, and antibiotic synthesis-related pathways in A. baumannii biofilms were strongly affected by octopromycin treatment. The collective findings indicate that the antibacterial peptide octopromycin may control A. baumannii biofilms through multi-target interactions. Octopromycin could be a desirable therapeutic option for the prevention and control of A. baumannii infections.}, }
@article {pmid36978452, year = {2023}, author = {Kuppusamy, R and Yasir, M and Yu, TT and Voli, F and Vittorio, O and Miller, MJ and Lewis, P and Black, DS and Willcox, M and Kumar, N}, title = {Tuning the Anthranilamide Peptidomimetic Design to Selectively Target Planktonic Bacteria and Biofilm.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030585}, pmid = {36978452}, issn = {2079-6382}, abstract = {There is a pressing need to develop new antimicrobials to help combat the increase in antibiotic resistance that is occurring worldwide. In the current research, short amphiphilic antibacterial and antibiofilm agents were produced by tuning the hydrophobic and cationic groups of anthranilamide peptidomimetics. The attachment of a lysine cationic group at the tail position increased activity against E. coli by >16-fold (from >125 μM to 15.6 μM) and greatly reduced cytotoxicity against mammalian cells (from ≤20 μM to ≥150 μM). These compounds showed significant disruption of preformed biofilms of S. aureus at micromolar concentrations.}, }
@article {pmid36978412, year = {2023}, author = {Praseetha, S and Sukumaran, ST and Dan, M and Augustus, AR and Pandian, SK and Sugathan, S}, title = {The Anti-Biofilm Potential of Linalool, a Major Compound from Hedychium larsenii, against Streptococcus pyogenes and Its Toxicity Assessment in Danio rerio.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030545}, pmid = {36978412}, issn = {2079-6382}, abstract = {The anti-biofilm and anti-virulence potential of the essential oil (E.O.) extracted from Hedychium larsenii M. Dan &amp; Sathish was determined against Streptococcus pyogenes. A crystal violet assay was employed to quantify the biofilm. Linalool, a monoterpene alcohol from the E.O., showed concentration-dependent biofilm inhibition, with a maximum of 91% at a concentration of 0.004% (v/v). The AlamarBlue[TM] assay also confirmed Linalool's non-bactericidal anti-biofilm efficacy (0.004%). Linalool treatment impeded micro-colony formation, mature biofilm architecture, surface coverage, and biofilm thickness and impaired cell surface hydrophobicity and EPS production. Cysteine protease synthesis was quantified using the Azocasein assay, and Linalool treatment augmented its production. This suggests that Linalool destabilizes the biofilm matrix. It altered the expression of core regulons covRS, mga, srv, and ropB, and genes associated with virulence and biofilm formation, such as speB, dltA, slo, hasA, and ciaH, as revealed by qPCR analysis. Cytotoxicity analysis using human kidney cells (HEK) and the histopathological analysis in Danio rerio proved Linalool to be a druggable molecule against the biofilms formed by S. pyogenes. This is the first report on Linalool's anti-biofilm and anti-virulence potential against S. pyogenes.}, }
@article {pmid36978402, year = {2023}, author = {Regulski, M and Myntti, MF and James, GA}, title = {Anti-Biofilm Efficacy of Commonly Used Wound Care Products in In Vitro Settings.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030536}, pmid = {36978402}, issn = {2079-6382}, abstract = {Considering the prevalence and pathogenicity of biofilms in wounds, this study was designed to evaluate the anti-biofilm capabilities of eight commercially available wound care products using established in vitro assays for biofilms. The products evaluated included dressings with multiple delivery formats for ionic silver including nanocrystalline, gelling fibers, polyurethane (PU) foam, and polymer matrix. Additionally, non-silver-based products including an extracellular polymeric substance (EPS)-dissolving antimicrobial wound gel (BDWG), a collagenase-based debriding ointment and a fish skin-based skin substitute were also evaluated. The products were evaluated on Staphylococcus aureus and Pseudomonas aeruginosa mixed-species biofilms grown using colony drip flow reactor (CDFR) and standard drip flow reactor (DFR) methodologies. Anti-biofilm efficacy was measured by viable plate counts and confocal scanning laser microscopy (CSLM). Four of the eight wound care products tested were efficacious in inhibiting growth of new biofilm when compared with untreated controls. These four products were further evaluated against mature biofilms. BDWG was the only product that achieved greater than 2-log growth reduction (5.88 and 6.58 for S. aureus and P. aeruginosa, respectively) of a mature biofilm. Evaluating both biofilm prevention and mature biofilm disruption capacity is important to a comprehensive understanding of the anti-biofilm efficacy of wound care products.}, }
@article {pmid36978347, year = {2023}, author = {Bomfim de Barros, D and de Oliveira E Lima, L and Alves da Silva, L and Cavalcante Fonseca, M and Ferreira, RC and Diniz Neto, H and da Nóbrega Alves, D and da Silva Rocha, WP and Scotti, L and de Oliveira Lima, E and Vieira Sobral, M and Cançado Castellano, LR and Moura-Mendes, J and Queiroga Sarmento Guerra, F and da Silva, MV}, title = {α-Pinene: Docking Study, Cytotoxicity, Mechanism of Action, and Anti-Biofilm Effect against Candida albicans.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030480}, pmid = {36978347}, issn = {2079-6382}, abstract = {Candida albicans is associated with serious infections in immunocompromised patients. Terpenes are natural-product derivatives, widely studied as antifungal alternatives. In a previous study reported by our group, the antifungal activity of α-pinene against C. albicans was verified; α-pinene presented an MIC between 128-512 µg/mL. In this study, we evaluate time-kill, a mechanism of action using in silico and in vitro tests, anti-biofilm activity against the Candida albicans, and toxicity against human cells (HaCaT). Results from the molecular-docking simulation demonstrated that thymidylate synthase (-52 kcal mol[-1]), and δ-14-sterol reductase (-44 kcal mol[-1]) presented the best interactions. Our in vitro results suggest that α-pinene's antifungal activity involves binding to ergosterol in the cellular membrane. In the time-kill assay, the antifungal activity was not time-dependent, and also inhibited biofilm formation, while rupturing up to 88% of existing biofilm. It was non-cytotoxic to human keratinocytes. Our study supports α-pinene as a candidate to treat fungal infections caused by C. albicans.}, }
@article {pmid36978196, year = {2023}, author = {Li, F and Huang, K and Wang, J and Yuan, K and Yang, Y and Liu, Y and Zhou, X and Kong, K and Yang, T and He, J and Liu, C and Ao, H and Liu, F and Liu, Q and Tang, T and Yang, S}, title = {A dual functional Ti-Ga alloy: inhibiting biofilm formation and osteoclastogenesis differentiation via disturbing iron metabolism.}, journal = {Biomaterials research}, volume = {27}, number = {1}, pages = {24}, pmid = {36978196}, issn = {1226-4601}, abstract = {BACKGROUND: Although biomedical implants have been widely used in orthopedic treatments, two major clinical challenges remain to be solved, one is the bacterial infection resulting in biofilm formation, and the other is aseptic loosening during implantation due to over-activated osteoclastogenesis. These factors can cause many clinical issues and even lead to implant failure. Thus, it is necessary to endow implants with antibiofilm and aseptic loosening-prevention properties, to facilitate the integration between implants and bone tissues for successful implantation. To achieve this goal, this study aimed to develop a biocompatible titanium alloy with antibiofilm and anti-aseptic loosening dual function by utilizing gallium (Ga) as a component.<br><br>METHODS: A series of Ti-Ga alloys were prepared. We examined the Ga content, Ga distribution, hardness, tensile strength, biocompatibility, and anti-biofilm performance in vitro and in vivo. We also explored how Ga[3+] ions inhibited the biofilm formation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and osteoclast differentiation.<br><br>RESULTS: The alloy exhibited outstanding antibiofilm properties against both S. aureus and E. coli in vitro and decent antibiofilm performance against S. aureus in vivo. The proteomics results demonstrated that Ga[3+] ions could disturb the bacterial Fe metabolism of both S. aureus and E. coli, inhibiting bacterial biofilm formation. In addition, Ti-Ga alloys could inhibit receptor activator of nuclear factor-&#x3ba;B ligand (RANKL)-dependent osteoclast differentiation and function by targeting iron metabolism, then suppressing the activation of the NF-&#x3ba;B signaling pathway, thus, showing their potential to prevent aseptic loosening.<br><br>CONCLUSION: This study provides an advanced Ti-Ga alloy that can be used as a promising orthopedic implant raw material for various clinical scenarios. This work also revealed that iron metabolism is the common target of Ga[3+] ions to inhibit biofilm formation and osteoclast differentiation.}, }
@article {pmid36976452, year = {2023}, author = {Ebrahimi, MT and Hedayati, MA and Pirlar, RF and Mortazavi, N and Nazari, M and Ahmadi, A and Hemmati, J and Erfani, Y}, title = {Investigation of the biofilm formation in extra-intestinal pathogenic Escherichia coli ST131 strains and its correlation with the presence of fimH, afa, and kpsMSTII genes.}, journal = {Journal of applied genetics}, volume = {}, number = {}, pages = {}, pmid = {36976452}, issn = {2190-3883}, abstract = {Escherichia coli sequence type 131 (ST131) is a multidrug-resistant strain with the global dissemination. Biofilm formation-related factors include the most important virulence factors in extra-intestinal pathogenic E. coli (ExPEC) ST131 strains causing infections with treatment-limited subjects. This study aims to investigate the biofilm formation ability and its correlation with the presence of fimH, afa, and kpsMSTII genes in clinical isolates of ExPEC ST131. In this regard, the prevalence and characteristics of these strains collected and evaluated. The results revealed strong, moderate, and weak attachment abilities related to biofilm formation attributes in 45%, 20%, and 35% of strains, respectively. In the meantime, the frequency of the fimH, afa, and kpsMSTII genes among the isolates was observed as follows: fimH positive: 65%; afa positive: 55%; and kpsMSTII positive: 85%. The results convey a significant different of biofilm formation ability between clinical E. coli ST131 and non-ST131 isolates. Furthermore, while 45% of ST131 isolates produced strong biofilms, only 2% of non-ST131 isolates showed the ability to form strong biofilms. The attending of fimH, afa, and kpsMSTII genes in the majority of ST131 strains demonstrated a key role leading to biofilm formation. These findings suggested the application of fimH, afa, and kpsMSTII gene suppressors for treating biofilm infections caused by drug-resistant ST131 strains.}, }
@article {pmid36972823, year = {2023}, author = {Wang, M and Muhammad, T and Gao, H and Liu, J and Liang, H}, title = {Targeted pH-responsive chitosan nanogels with Tanshinone IIA for enhancing the antibacterial/anti-biofilm efficacy.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {124177}, doi = {10.1016/j.ijbiomac.2023.124177}, pmid = {36972823}, issn = {1879-0003}, abstract = {Persistent bacterial infection caused by biofilms is one of the most serious problems that threatened human health. The development of antibacterial agents remains a challenge to penetrate biofilm and effectively treat the underlying bacterial infection. In the current study, chitosan-based nanogels were developed for encapsulating the Tanshinone IIA (TA) to enhance the antibacterial and anti-biofilm efficacy against Streptococcus mutans (S. mutans). The as-prepared nanogels (TA@CS) displayed excellent encapsulation efficiency (91.41 ± 0.11 %), uniform particle sizes (393.97 ± 13.92 nm), and enhanced positive potential (42.27 ± 1.25 mV). After being coated with CS, the stability of TA under light and other harsh environments was greatly improved. In addition, TA@CS displayed pH responsiveness, allowing it to selectively release more TA in acidic conditions. Furthermore, the positively charged TA@CS were equipped to target negatively charged biofilm surfaces and efficiently penetrate through biofilm barriers, making it promising for remarkable anti-biofilm activity. More importantly, when TA was encapsulated into CS nanogels, the antibacterial activity of TA was enhanced at least 4-fold. Meanwhile, TA@CS inhibited 72 % of biofilm formation at 500 μg/mL. The results demonstrated that the nanogels constituted CS and TA had antibacterial/anti-biofilm properties with synergistic enhanced effects, which will benefit pharmaceutical, food, and other fields.}, }
@article {pmid36972812, year = {2023}, author = {Tian, H and Li, Y and Chen, H and Zhang, J and Hui, M and Xu, X and Su, Q and Smets, BF}, title = {Aerobic biodegradation of quinoline under denitrifying conditions in membrane-aerated biofilm reactor.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {326}, number = {}, pages = {121507}, doi = {10.1016/j.envpol.2023.121507}, pmid = {36972812}, issn = {1873-6424}, abstract = {Aerobic denitrification is being investigated as a novel biological nitrogen removal process, yet the knowledge on aerobic denitrification is limited to pure culture isolations and its occurrence in bioreactors remains unclear. This study investigated the feasibility and capacity of applying aerobic denitrification in membrane aerated biofilm reactor (MABR) for biological treatment of quinoline-laden wastewater. Stable and efficient removals of quinoline (91.5 ± 5.2%) and nitrate (NO3[-]) (86.5 ± 9.3%) were obtained under different operational conditions. Enhanced formation and function of extracellular polymeric substances (EPS) were observed at increasing quinoline loadings. MABR biofilm was highly enriched with aerobic quinoline-degrading bacteria, with a predominance of Rhodococcus (26.9 ± 3.7%) and secondary abundance of Pseudomonas (1.7 ± 1.2%) and Comamonas (0.94 ± 0.9%). Metagenomic analysis indicated that Rhodococcus contributed significantly to both aromatic degradation (24.5 ± 21.3%) and NO3[-] reduction (4.5 ± 3.9%), indicating its key role in aerobic denitrifying quinoline biodegradation. At increasing quinoline loadings, abundances of aerobic quinoline degradation gene oxoO and denitrifying genes of napA, nirS and nirK increased; there was a significant positive correlation of oxoO with nirS and nirK (p < 0.05). Aerobic quinoline degradation was likely initiated by hydroxylation, encoded by oxoO, followed by stepwise oxidations through 5,6-dihydroxy-1H-2-oxoquinoline or 8-hydroxycoumarin pathway. The results advance our understanding of quinoline degradation during biological nitrogen removal, and highlight the potential implementation of aerobic denitrification driven quinoline biodegradation in MABR for simultaneous removal of nitrogen and recalcitrant organic carbon from coking, coal gasification and pharmaceutical wastewaters.}, }
@article {pmid36972615, year = {2023}, author = {de Oliveira Martinez, JP and Vazquez, L and Takeyama, MM and Dos Santos Filho, TJ and Cavalcante, FS and Guimarães, LC and Pereira, EM and Dos Santos, KRN}, title = {Novel biochemical aspects of lugdulysin, a Staphylococcus lugdunensis metalloprotease that inhibits formation and disrupts protein biofilm of methicillin-resistant Staphylococcus aureus.}, journal = {Bioscience, biotechnology, and biochemistry}, volume = {}, number = {}, pages = {}, doi = {10.1093/bbb/zbad035}, pmid = {36972615}, issn = {1347-6947}, abstract = {Staphylococcus lugdunensis produces lugdulysin, a metalloprotease that may contribute to its virulence. This study aimed to evaluate the biochemical aspects of lugdulysin and investigate its effect on Staphylococcus aureus biofilms. The protease was isolated and characterized for its optimal pH and temperature, hydrolysis kinetics, and influence of metal cofactor supplementation. The protein structure was determined via homology modelling. The effect on S. aureus biofilms was assessed by the micromethod technique. The protease optimal pH and temperature were 7.0 and 37°C, respectively. EDTA inhibited protease activity, confirming it as a metalloprotease. Lugdulysin activity was not recovered by divalent ion supplementation post-inhibition and supplementation with divalent ions did not change enzymatic activity. The isolated enzyme was stable for up to 3 hours. Lugdulysin significantly inhibited the formation and disrupted pre-established protein-matrix MRSA biofilm. This preliminary study indicates that lugdulysin has a potential role as a competition mechanism and/or modulation of staphylococcal biofilm.}, }
@article {pmid36971546, year = {2023}, author = {Yahya, AH and Harston, SR and Colton, WL and Cabeen, MT}, title = {Distinct Screening Approaches Uncover PA14_36820 and RecA as Negative Regulators of Biofilm Phenotypes in Pseudomonas aeruginosa PA14.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0377422}, doi = {10.1128/spectrum.03774-22}, pmid = {36971546}, issn = {2165-0497}, abstract = {Pseudomonas aeruginosa commonly infects hospitalized patients and the lungs of individuals with cystic fibrosis. This species is known for forming biofilms, which are communities of bacterial cells held together and encapsulated by a self-produced extracellular matrix. The matrix provides extra protection to the constituent cells, making P. aeruginosa infections challenging to treat. We previously identified a gene, PA14_16550, which encodes a DNA-binding TetR-type repressor and whose deletion reduced biofilm formation. Here, we assessed the transcriptional impact of the 16550 deletion and found six differentially regulated genes. Among them, our results implicated PA14_36820 as a negative regulator of biofilm matrix production, while the remaining 5 had modest effects on swarming motility. We also screened a transposon library in a biofilm-impaired ΔamrZ Δ16550 strain for restoration of matrix production. Surprisingly, we found that disruption or deletion of recA increased biofilm matrix production, both in biofilm-impaired and wild-type strains. Because RecA functions both in recombination and in the DNA damage response, we asked which function of RecA is important with respect to biofilm formation by using point mutations in recA and lexA to specifically disable each function. Our results implied that loss of either function of RecA impacts biofilm formation, suggesting that enhanced biofilm formation may be one physiological response of P. aeruginosa cells to loss of either RecA function. IMPORTANCE Pseudomonas aeruginosa is a notorious human pathogen well known for forming biofilms, communities of bacteria that protect themselves within a self-secreted matrix. Here, we sought to find genetic determinants that impacted biofilm matrix production in P. aeruginosa strains. We identified a largely uncharacterized protein (PA14_36820) and, surprisingly, RecA, a widely conserved bacterial DNA recombination and repair protein, as negatively regulating biofilm matrix production. Because RecA has two main functions, we used specific mutations to isolate each function and found that both functions influenced matrix production. Identifying negative regulators of biofilm production may suggest future strategies to reduce the formation of treatment-resistant biofilms.}, }
@article {pmid36971485, year = {2023}, author = {Ousey, K and Ovens, L}, title = {Comparing methods of debridement for removing biofilm in hard-to-heal wounds.}, journal = {Journal of wound care}, volume = {32}, number = {Sup3b}, pages = {S4-S10}, doi = {10.12968/jowc.2023.32.Sup3b.S4}, pmid = {36971485}, issn = {0969-0700}, mesh = {Humans ; Debridement/methods ; *Wound Healing ; *Wound Infection/therapy ; Biofilms ; }, }
@article {pmid36970701, year = {2023}, author = {Aljohani, AM and El-Chami, C and Alhubail, M and Ledder, RG and O'Neill, CA and McBain, AJ}, title = {Escherichia coli Nissle 1917 inhibits biofilm formation and mitigates virulence in Pseudomonas aeruginosa.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1108273}, pmid = {36970701}, issn = {1664-302X}, abstract = {In the quest for mitigators of bacterial virulence, cell-free supernatants (CFS) from 25 human commensal and associated bacteria were tested for activity against Pseudomonas aeruginosa. Among these, Escherichia coli Nissle 1917 CFS significantly inhibited biofilm formation and dispersed extant pseudomonas biofilms without inhibiting planktonic bacterial growth. eDNA was reduced in biofilms following exposure to E. coli Nissle CFS, as visualized by confocal microscopy. E. coli Nissle CFS also showed a significant protective effect in a Galleria mellonella-based larval virulence assay when administrated 24 h before challenge with the P. aeruginosa. No inhibitory effects against P. aeruginosa were observed for other tested E. coli strains. According to proteomic analysis, E. coli Nissle CFS downregulated the expression of several P. aeruginosa proteins involved in motility (Flagellar secretion chaperone FliSB, B-type flagellin fliC, Type IV pilus assembly ATPase PilB), and quorum sensing (acyl-homoserine lactone synthase lasI and HTH-type quorum-sensing regulator rhlR), which are associated with biofilm formation. Physicochemical characterization of the putative antibiofilm compound(s) indicates the involvement of heat-labile proteinaceous factors of greater than 30 kDa molecular size.}, }
@article {pmid36969800, year = {2023}, author = {Delaney, C and Short, B and Rajendran, R and Kean, R and Burgess, K and Williams, C and Munro, CA and Ramage, G}, title = {An integrated transcriptomic and metabolomic approach to investigate the heterogeneous Candida albicans biofilm phenotype.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100112}, pmid = {36969800}, issn = {2590-2075}, abstract = {Candida albicans is the most prevalent and notorious of the Candida species involved in bloodstream infections, which is characterised by its capacity to form robust biofilms. Biofilm formation is an important clinical entity shown to be highly variable among clinical isolates. There are various environmental and physiological factors, including nutrient availability which influence the phenotype of Candida species. However, mechanisms underpinning adaptive biofilm heterogeneity have not yet been fully explored. Within this study we have profiled previously characterised and phenotypically distinct C. albicans bloodstream isolates. We assessed the dynamic susceptibility of these differing populations to antifungal treatments using population analysis profiling in addition to assessing biofilm formation and morphological changes. High throughput methodologies of RNA-Seq and LC-MS were employed to map and integrate the transcriptional and metabolic reprogramming undertaken by heterogenous C. albicans isolates in response to biofilm and hyphal inducing serum. We found a significant relationship between biofilm heterogeneity and azole resistance (P < 0.05). In addition, we observed that in response to serum our low biofilm forming (LBF) C. albicans exhibited a significant increase in biofilm formation and hyphal elongation. The transcriptional reprogramming of LBF strains compared to high biofilm forming (HBF) was distinct, indicating a high level of plasticity and variation in stress responses by heterogenous strains. The metabolic responses, although variable between LBF and HBF, shared many of the same responses to serum. Notably, a high upregulation of the arachidonic acid cascade, part of the COX pathway, was observed and this pathway was found to induce biofilm formation in LBF 3-fold. C. albicans is a highly heterogenous bloodstream pathogen with clinical isolates varying in antifungal tolerance and biofilm formation. In addition to this, C. albicans is capable of highly complex and variable regulation of transcription and metabolic pathways and heterogeneity across isolates further increases the complexity of these pathways. Here we have shown with a dual and integrated approach, the importance of studying a diverse panel of C. albicans isolates, which has the potential to reveal distinct pathways that can harnessed for drug discovery.}, }
@article {pmid36969455, year = {2023}, author = {Kang, MG and Khan, F and Tabassum, N and Cho, KJ and Jo, DM and Kim, YM}, title = {Inhibition of Biofilm and Virulence Properties of Pathogenic Bacteria by Silver and Gold Nanoparticles Synthesized from Lactiplantibacillus sp. Strain C1.}, journal = {ACS omega}, volume = {8}, number = {11}, pages = {9873-9888}, pmid = {36969455}, issn = {2470-1343}, abstract = {The emergence of antibiotic resistance in microbial pathogens necessitates the development of alternative ways to combat the infections that arise. The current study used nanotechnology as an alternate technique to control virulence characteristics and biofilm development in Pseudomonas aeruginosa and Staphylococcus aureus. Furthermore, based on the acceptance and biocompatibility of the probiotic bacteria, we chose a lactic acid bacteria (LAB) for synthesizing two types of metallic nanoparticles (NPs) in this study. Using molecular techniques, the LAB strain C1 was isolated from Kimchi food samples and identified as Lactiplantibacillus sp. strain C1. The prepared supernatant from strain C1 was used to produce gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs). C1-AuNPs and C1-AgNPs were characterized physiochemically using a variety of instruments. C1-AuNPs and C1-AgNPs had spherical shapes and sizes of 100.54 ± 14.07 nm (AuNPs) and 129.51 ± 12.31 nm (AgNPs), respectively. C1-AuNPs and C1-AgNPs were discovered to have high zeta potentials of -23.29 ± 1.17 and -30.57 ± 0.29 mV, respectively. These nanoparticles have antibacterial properties against several bacterial pathogens. C1-AuNPs and C1-AgNPs significantly inhibited the initial stage biofilm formation and effectively eradicated established mature biofilms of P. aeruginosa and S. aureus. Furthermore, when P. aeruginosa was treated with sub-MIC levels of C1-AuNPs and C1-AgNPs, their different virulence features were significantly reduced. Both NPs greatly inhibited the hemolytic activity of S. aureus. The inhibition of P. aeruginosa and S. aureus biofilms and virulence features by C1-AuNPs and C1-AgNPs can be regarded as viable therapeutic strategies for preventing infections caused by these bacteria.}, }
@article {pmid36968011, year = {2023}, author = {Nguyen, HTT and Nguyen, TH and Otto, M}, title = {Corrigendum to "The staphylococcal exopolysaccharide PIA - Biosynthesis and role in biofilm formation, colonization, and infection" [Comput Struct Biotechnol J 4/18 (2020) 3324-3334].}, journal = {Computational and structural biotechnology journal}, volume = {21}, number = {}, pages = {2035}, doi = {10.1016/j.csbj.2023.03.012}, pmid = {36968011}, issn = {2001-0370}, abstract = {[This corrects the article DOI: 10.1016/j.csbj.2020.10.027.].}, }
@article {pmid36967885, year = {2023}, author = {He, C and Li, B and Gong, Z and Huang, S and Liu, X and Wang, J and Xie, J and Shi, T}, title = {Polyphosphate kinase 1 is involved in formation, the morphology and ultramicrostructure of biofilm of Mycobacterium smegmatis and its survivability in macrophage.}, journal = {Heliyon}, volume = {9}, number = {3}, pages = {e14513}, pmid = {36967885}, issn = {2405-8440}, abstract = {The most unique characteristic of Mycobacterium tuberculosis is persistence in the human host, and the biofilm formation is related to the persistance. Polyphosphate (polyP) kinase 1 (PPK1) is conserved in Mycobacteria and is responsible for polyP synthesis. polyP is a chain molecule linked by high-energy phosphate bonds, which is considered to play a very important role in bacterial persistence. However, the relationship of PPK1 and mycobacterial biofilm formation is still adequately unclear. In current study, ppk1-deficient mutant (MT), ppk1-complemented (CT) and wild-type strains of M. smegmatis mc[2] 155 were used to investigate the formation, morphology and ultramicrostructure of the biofilm and to analyze the lipid levels and susceptibility to vancomycin antibiotic. And then WT, MT and CT strains were used to infect macrophages and to analyze the expression levels of various inflammatory factors, respectively. We found that PPK1 was required for M. smegmatis polyP production in vivo and polyP deficiency not only attenuated the biofilm formation, but also altered the phenotype and ultramicrostructure of the biofilm and reduced the cell lipid composition (except for C16.1 and C17.1, most of the fatty acid components from C8-C24). Moreover, the ppk1-deficient mutant was also significantly more sensitive to vancomycin which targets the cell wall, and its ability to survive in macrophages was decreased, which was related to the change of the expression level of inflammatory factors in macrophage. This study demonstrates that the PPK1 can affect the biofilm structure through affecting the content of short chain fatty acid and promote intracellular survival of M. smegmatis by altering the expression of inflammatory factors. These findings establish a basis for investigating the role of PPK1 in the persistence of M. tuberculosis, and provide clues for treating latent infection of M. tuberculosis with PPK1 as a potential drug target.}, }
@article {pmid36967503, year = {2023}, author = {Majeed, N and Ismail, F}, title = {In vitro characteristics of fungal biofilm formation and the influence of physiological stress on biofilm growth.}, journal = {Pakistan journal of pharmaceutical sciences}, volume = {36}, number = {1}, pages = {103-109}, pmid = {36967503}, issn = {1011-601X}, abstract = {Fungal biofilms are a growing clinical concern associated with high mortality rates. This study included three fungal groups, dimorphic fungi (Candida albicans), Dermatophytes (Trichophyton mentagrophytes) and non-dermatophytes (Acremonium sclerotigenum, Aspergillus niger). This research describes the in vitro characteristics of biofilm formation in three fungal groups. The influence of osmotic, oxidative and pH stress environment on biofilm growth was also focused. Biofilm characteristics in A. sclerotigenum and A. niger were studied for the first time. In vitro qualitative and quantitative approaches were used to evaluate biofilm development including the test tube method, tissue culture plate method in addition to staining with crystal violet and safranin. All the isolates were able to form biofilm. Biofilm development under different pH range showed maximum growth at neutral pH. At a concentration of 5mM hydrogen peroxide and 2M NaCl biofilm formation was maximum for all three fungal groups under an oxidative and osmotic stress respectively. Study revealed that biofilm production was increased under osmotic and oxidative stress. All isolates respond to oxidative and osmotic stress by changing the cell wall composition with a rich exopolymeric matrix in order to survive in stress environment.}, }
@article {pmid36966927, year = {2023}, author = {Liu, Q and Hou, J and Zeng, Y and Wu, J and Miao, L and Yang, Z}, title = {Fabrication of an intimately coupled photocatalysis and biofilm system for removing sulfamethoxazole from wastewater: Effectiveness, degradation pathway and microbial community analysis.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138507}, doi = {10.1016/j.chemosphere.2023.138507}, pmid = {36966927}, issn = {1879-1298}, abstract = {Sulfamethoxazole (SMX) is an extensively applied antibiotic frequently detected in municipal wastewater, which cannot be efficiently removed by conventional biological wastewater processes. In this work, an intimately coupled photocatalysis and biodegradation (ICPB) system consisting of Fe[3+]-doped graphitic carbon nitride photocatalyst and biofilm carriers was fabricated to remove SMX. The results of wastewater treatment experiments showed that 81.2 ± 2.1% of SMX was removed in the ICPB system during the 12 h, while only 23.7 ± 4.0% was removed in the biofilm system within the same time. In the ICPB system, photocatalysis played a key role in removing SMX by producing hydroxyl radicals and superoxide radicals. Besides, the synergism between photocatalysis and biodegradation enhanced the mineralization of SMX. To understand the degradation process of SMX, nine degradation products and possible degradation pathways of SMX were analyzed. The results of high throughput sequencing showed that the diversity, abundance, and structure of the biofilm microbial community remained stable in the ICPB system at the end of the experiments, which suggested that microorganisms had accommodated to the environment of the ICPB system. This study could provide insights into the application of the ICPB system in treating antibiotic-contaminated wastewater.}, }
@article {pmid36966821, year = {2023}, author = {Zhang, H and Gong, W and Xue, Y and Zeng, W and Wang, H and Wang, J and Tang, X and Li, G and Liang, H}, title = {Municipal wastewater contains antibiotic treatment using O2 transfer membrane based biofilm reactor: Interaction between regular pollutants metabolism and sulfamethoxazole degradation.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {163060}, doi = {10.1016/j.scitotenv.2023.163060}, pmid = {36966821}, issn = {1879-1026}, abstract = {The antibiotic sulfamethoxazole (SMX) is frequently detected in wastewater treatment plant effluents and has attracted significant attention owing to its significant potential environmental effects. We present a novel O2 transfer membrane based biofilm reactor (O2TM-BR) to treat municipal wastewater to eliminate containing SMX. Furthermore, conducting metagenomics analyses, the interactions in biodegradation process between SMX and regular pollutants (NH4[+]-N and COD) were studied. Results suggest that O2TM-BR yields evident advantages in SMX degradation. Increasing SMX concentrations did not affect the efficiency of the system, and the effluent concentration remained consistent at approximately 17.0 μg/L. The interaction experiment showed that heterotrophic bacteria tend to consume easily degradable COD for metabolism, resulting in a delay (>36 h) in complete SMX degradation, which is 3-times longer than without COD. It is worth noting that the taxonomic and functional structure and composition in nitrogen metabolism were significantly shifted upon the SMX. NH4[+]-N removal remained unaffected by SMX in O2TM-BR, and the expression of K10944 and K10535 has no significant difference under the stress of SMX (P > 0.02). However, the K00376 and K02567 required in the nitrate reductase is inhibited by SMX (P < 0.01), which hinders the reduction of NO3[-]-N and hence the accumulation of TN. This study provides a new method for SMX treatment and reveals the interaction between SMX and conventional pollutants in O2TM-BR as well as the microbial community function and assembly mechanism.}, }
@article {pmid36965588, year = {2023}, author = {Zhong, J and Liu, J and Hu, R and Pan, D and Shao, S and Wu, X}, title = {Performance of nitrification-denitrification and denitrifying phosphorus removal driven by in-situ generated biogenic manganese oxides in a moving bed biofilm reactor.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128957}, doi = {10.1016/j.biortech.2023.128957}, pmid = {36965588}, issn = {1873-2976}, abstract = {Simultaneous removal of NH4[+]-N, NO3[-]-N, COD, and P by manganese redox cycling in nutrient wastewater was established with two moving bed biofilm reactors (MBBRs) with in-situ generated biogenic manganese oxides (BioMnOx) and non-BioMnOx. In-situ generated BioMnOx preferentially promoted the denitrification, and the average removal of NO3[-]-N, NH4[+]-N, and TN in the experimental MBBR with BioMnOx increased to 89.00%, 70.64%, and 76.06% compared with the control MBBR with non-BioMnOx. The relevant enzymes activity, extracellular polymeric substance (EPS), electron transport system activity (ETSA), and reactive oxygen species (ROS) were investigated. The element valence and morphology of purified BioMnOx were characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM), as well as the effect of BioMnOx on nitrogen and phosphorus removal. The results suggested that BioMnOx could improve nitrogen conversion. Electrochemical characteristic and microbial community were detected. This study provided a new strategy for nutrients removal in BioMnOx-mediated wastewater treatment.}, }
@article {pmid36965431, year = {2023}, author = {Gao, S and Sun, Y and Lu, Z and Jiang, N and Yao, H}, title = {Synergistic antibacterial and biofilm eradication activity of quaternary-ammonium compound with copper ion.}, journal = {Journal of inorganic biochemistry}, volume = {243}, number = {}, pages = {112190}, doi = {10.1016/j.jinorgbio.2023.112190}, pmid = {36965431}, issn = {1873-3344}, abstract = {Antibiotics overuse and misuse increase the emergence of multidrug-resistant bacterial strains, which often leads to the failure of conventional antibiotic therapies. Even worse, the tendency of bacteria to form biofilms further increases the therapeutic difficulty, because the extracellular matrix prevents the penetration of antibiotics and triggers bacterial tolerance. Therefore, developing novel antibacterial agents or therapeutic strategies with diverse antibacterial mechanisms and destruction of bacteria biofilm is a promising way to combat bacterial infections. In the present study, the combination of quaternary ammonium compound poly(diallyl dimethyl ammonium chloride) (PDDA) with Cu[2+] was screened out to fight common pathogenic Staphylococcus aureus (S. aureus) through multi-mechanisms. This combination appeared strong synergistic antibacterial activity, and the fractional inhibitory concentration index was as low as 0.032. The synergistic antibacterial mechanism involved the destruction of the membrane function, generation of intracellular reactive oxygen, and promotion more Cu[2+] into the cytoplasm. Further, the combination of PDDA and Cu[2+] reduced the extracellular polysaccharide matrix, meanwhile killing the bacteria embedded in the biofilm. The biocompatibility study in vitro revealed this combination exhibited low cytotoxicity and hemolysis ratio even at 8 times of minimum bactericidal concentration. This work provides a novel antibacterial agents combination with higher efficiency to fight planktonic and biofilm conditions of S. aureus.}, }
@article {pmid36965425, year = {2023}, author = {Zhang, X and Ji, B and Tian, J and Liu, Y}, title = {Development, performance and microbial community analysis of a continuous-flow microalgal-bacterial biofilm photoreactor for municipal wastewater treatment.}, journal = {Journal of environmental management}, volume = {338}, number = {}, pages = {117770}, doi = {10.1016/j.jenvman.2023.117770}, pmid = {36965425}, issn = {1095-8630}, abstract = {This work reported the development, performance and microbial community of microalgal-bacterial biofilms cultivated in a continuous-flow photoreactor for municipal wastewater treatment under various conditions. Results showed that microalgal-bacterial biofilms were successfully developed at a HRT of 9 h without external aeration, with a biofilm concentration of around 4690 mg/L being achieved in the steady-state. It was found that further increase of HRT to 12 h did not improve the overall accumulation of biofilm, whereas the growth of microalgae in biofilms was faster than bacteria in the initial stage, indicated by an increased chlorophyll-a&amp;b content in biofilms. After which, the chlorophyll-a&amp;b content in biofilms gradually stabilized at the level comparable with the seed, suggesting that there was a balanced distribution of microalgae and bacteria in biofilms. About 90% of TOC, 71.4% of total nitrogen and 72.6% of phosphorus were removed by microalgal-bacterial biofilms mainly through assimilation in the steady-state photoreactor run at the HRT of 12 h with external aeration. The community analysis further revealed that Cyanobacteria and Chloroflexi were the main components, while Chlorophyta appeared to be the dominant eukaryotic algal community in biofilms. This study could offer new insights into the development of microalgal-bacterial biofilms in a continuous-flow photoreactor for sustainable low-carbon municipal wastewater treatment.}, }
@article {pmid36963701, year = {2023}, author = {Zhao, J and Dong, X and Su, H and Huang, J and Liu, Z and He, P and Zhang, D}, title = {Rapid start-up of PN/A process and efficient enrichment of functional bacteria: a novel aerobic-biofilm/anaerobic-granular nitrogen removal system (OANRS).}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128944}, doi = {10.1016/j.biortech.2023.128944}, pmid = {36963701}, issn = {1873-2976}, abstract = {Reactor configuration, control strategy and inoculation method were key factors affecting the rapid start-up of partial nitrification/anammox (PN/A) process and the efficient enrichment of functional bacteria (anammox and ammonia oxidizing bacteria). At present, PN/A process was generally operated through single factor rather than forming a system. In this study, a novel aerobic-biofilm/anaerobic-granular nitrogen removal system (OANRS) was constructed, which consisted of a multi-stage aerobic-biofilm/anaerobic-granular baffle reactor (MOABR) and a control strategy on pH/aeration time. PN process was started within 10d, and PN/A process was started on the basis of stable PN process within 41d. The simultaneous enrichment of functional bacteria was achieved by combining the advantages of single-stage and two-stage PN/A process. The results of high-throughput sequencing showed that Candidatus Kuenenia (20.42±15.88%) was highly enriched in each compartment at day 98, and the relative abundance of Candidatus Kuenenia in the anaerobic compartment R4 was as high as 43.13%.}, }
@article {pmid36963576, year = {2023}, author = {Li, M and Perez-Calleja, P and Kim, B and Picioreanu, C and Nerenberg, R}, title = {Unique stratification of biofilm density in heterotrophic membrane-aerated biofilms: An experimental and modeling study.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138501}, doi = {10.1016/j.chemosphere.2023.138501}, pmid = {36963576}, issn = {1879-1298}, abstract = {We consistently find a band of high cell density develop within heterotrophic membrane-aerated biofilms. This study reports and attempts to explain this unique behavior. Biofilm density affects volumetric reaction rates, biofilm growth rates, substrate diffusion, and mechanical behavior. Yet the mechanisms and dynamics of biofilm density development are poorly understood. In this study, a membrane-aerated biofilm, where O2 was supplied from the base of the biofilm and acetate from the bulk liquid, was used to explore spatial and temporal patterns of density development. Biofilm density was assessed by optical coherence tomography. After inoculation, the biofilm quickly increased in thickness, with a low density throughout. However, as the biofilm reached a stable thickness of around 1000 μm, a high-density layer developed in the biofilm interior. The layer slowly expanded over time. Oxygen microprofiles in the biofilm showed this layer coincided with the most metabolically active zone, resulting from counter-diffusing O2 and acetate. The formation of this dense layer appeared to be related to changes in growth rates. Initially, high growth rates throughout the biofilm presumably led to fast-growing, low-density biofilms. As the biofilm became thicker, and as substrates became limiting in the biofilm interior, growth rates decreased, resulting in new growth at a higher density. A 1-D mathematical model with variable biofilm density was developed by linking the rates of extracellular polymeric substances (EPS) production to the growth rate. The model captured the initial fast growth at a low density, followed by a slower, substrate-limited growth in the biofilm interior, producing a dense band within the biofilm. Together, these results suggest that low growth rates can lead to high-density zones within the interior of counter-diffusional biofilms. These findings should also be relevant to conventional, co-diffusional biofilms, although differences in density may be less obvious.}, }
@article {pmid36960491, year = {2023}, author = {Johnston, W and Rosier, BT and Carda-Diéguez, M and Paterson, M and Watson, P and Piela, K and Goulding, M and Ramage, G and Baranyia, D and Chen, T and Al-Hebshi, N and Mira, A and Culshaw, S}, title = {Longitudinal changes in subgingival biofilm composition following periodontal treatment.}, journal = {Journal of periodontology}, volume = {}, number = {}, pages = {}, doi = {10.1002/JPER.22-0749}, pmid = {36960491}, issn = {1943-3670}, abstract = {BACKGROUND: Current periodontal treatment involves instrumentation using hand and/or ultrasonic instruments, which are used either alone or in combination based on patient and clinician preference, with comparable clinical outcomes. This study sought to investigate early and later changes in the subgingival biofilm following periodontal treatment; to identify whether these changes were associated with treatment outcomes; and to investigate whether the biofilm responded differently to hand compared with ultrasonic instruments.<br><br>METHODS: This was a secondary-outcome analysis of a randomised controlled trial. Thirty-eight periodontitis patients received full-mouth subgingival instrumentation using hand (n = 20) or ultrasonic instrumentation (n = 18). Subgingival plaque was sampled at baseline and 1, 7 and 90 days following treatment. Bacterial DNA was analysed using 16S rRNA sequencing. Periodontal clinical parameters were evaluated before and after treatment.<br><br>RESULTS: Biofilm composition was comparable in both (hand and ultrasonics) treatment groups at all timepoints (all genus and species; p[adjusted]>0.05). Large-scale changes were observed within-groups across timepoints. At days 1 and 7, taxonomic diversity and dysbiosis were reduced, with an increase in health-associated genera including Streptococcus and Rothia equating to 30-40% of the relative abundance. When reassessed at day 90 a subset of samples reformed a microbiome more comparable with baseline, which was independent of instrumentation choice and residual disease.<br><br>CONCLUSIONS: Hand and ultrasonic instruments induced comparable impacts on the subgingival plaque microbiome. There were marked early changes in the subgingival biofilm composition, although there was limited evidence that community shifts associated with treatment outcomes. This article is protected by copyright. All rights reserved.}, }
@article {pmid36959476, year = {2023}, author = {Kilic, T and Bali, EB}, title = {Biofilm control strategies in the light of biofilm-forming microorganisms.}, journal = {World journal of microbiology &amp; biotechnology}, volume = {39}, number = {5}, pages = {131}, pmid = {36959476}, issn = {1573-0972}, abstract = {Biofilm is a complex consortium of microorganisms attached to biotic or abiotic surfaces and live in self-produced or acquired extracellular polymeric substances (EPSs). EPSs are mainly formed by lipids, polysaccharides, proteins, and extracellular DNAs. The adherence to the surface of microbial communities is seen in food, medical, dental, industrial, and environmental fields. Biofilm development in food processing areas challenges food hygiene, and human health. In addition, bacterial attachment and biofilm formation on medical implants inside human tissue can cause multiple critical chronic infections. More than 30 years of international research on the mechanisms of biofilm formation have been underway to address concerns about bacterial biofilm infections. Antibiofilm strategies contain cold atmospheric plasma, nanotechnological, phage-based, antimicrobial peptides, and quorum sensing inhibition. In the last years, the studies on environmentally-friendly techniques such as essential oils and bacteriophages have been intensified to reduce microbial growth. However, the mechanisms of the biofilm matrix formation are still unclear. This review aims to discuss the latest antibiofilm therapeutic strategies against biofilm-forming bacteria.}, }
@article {pmid36959215, year = {2023}, author = {Bech, PK and Zhang, SD and Henriksen, NNSE and Bentzon-Tilia, M and Strube, ML and Gram, L}, title = {The potential to produce tropodithietic acid by Phaeobacter inhibens affects the assembly of microbial biofilm communities in natural seawater.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {12}, pmid = {36959215}, issn = {2055-5008}, abstract = {Microbial secondary metabolites play important roles in biotic interactions in microbial communities and yet, we do not understand how these compounds impact the assembly and development of microbial communities. To address the implications of microbial secondary metabolite production on biotic interactions in the assembly of natural seawater microbiomes, we constructed a model system where the assembly of a natural seawater biofilm community was influenced by the addition of the marine biofilm forming Phaeobacter inhibens that can produce the antibiotic secondary metabolite tropodithietic acid (TDA), or a mutant incapable of TDA production. Because of the broad antibiotic activity of TDA, we hypothesized that the potential of P. inhibens to produce TDA would strongly affect both biofilm and planktonic community assembly patterns. We show that 1.9 % of the microbial composition variance across both environments could be attributed to the presence of WT P. inhibens, and especially genera of the Bacteriodetes were increased by the presence of the TDA producer. Moreover, network analysis with inferred putative microbial interactions revealed that P. inhibens mainly displayed strong positive associations with genera of the Flavobacteriaceae and Alteromonadaceae, and that P. inhibens acts as a keystone OTU in the biofilm exclusively due to its potential to produce TDA. Our results demonstrate the potential impact of microbial secondary metabolites on microbial interactions and assembly dynamics of complex microbial communities.}, }
@article {pmid36950165, year = {2023}, author = {Racioppo, A and Speranza, B and Altieri, C and Sinigaglia, M and Corbo, MR and Bevilacqua, A}, title = {Ultrasound can increase biofilm formation by Lactiplantibacillus plantarum and Bifidobacterium spp.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1094671}, pmid = {36950165}, issn = {1664-302X}, abstract = {The main goal of this research was to study the effect of an Ultrasound (US) treatment on biofilm formation of Lactiplantibacillus plantarum (strains c19 and DSM 1055), Bifidobacterium animalis subsp. lactis DSM 10140, Bifidobacterium longum subsp. longum DSM 20219, and Bifidobacterium longum subsp. infantis DSM 20088. From a methodological point of view, each microorganism was treated through six US treatments, different for the power (10, 30, or 50% of the net power, 130 W), the duration (2, 6, or 10 min) and the application of pulses (0 or 10 s). After the treatment, a biofilm of the strains was let to form on glass slides and the concentration of sessile cells was analyzed for 16 days. Biofilms formed by untreated microorganisms were used as controls. As a first result, it was found that US significantly increased the concentration of sessile cells of B. longum subsp. infantis, while for some other strains US treatment could not affect the formation of biofilm while improving its stability, as found for L. plantarum DSM1055 after 16 days. The variable mainly involved in this positive effect of US was the duration of the treatment, as biofilm formation and stability were improved only for 2 min-treatments; on the other hand, the effect of power and pulses were strain-dependent. In conclusion, the results suggest practical implication of a US pre-treatment for various fields (improvement of adhesion of microorganisms useful in food or in the gut, biomedical and environmental industries), although further investigations are required to elucidate the mode of action.}, }
@article {pmid36950159, year = {2023}, author = {Liang, J and Huang, TY and Mao, Y and Li, X}, title = {Biofilm formation of two genetically diverse Staphylococcus aureus isolates under beta-lactam antibiotics.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1139753}, pmid = {36950159}, issn = {1664-302X}, abstract = {PURPOSE: Our aim was to evaluate the biofilm formation of 2 genetically diverse Staphylococcus aureus isolates, 10379 and 121940, under different concentrations of beta-lactam antibiotics on biomass content and biofilm viability.<br><br>METHODS: Biofilm formation and methicillin resistance genes were tested using PCR and multiplex PCR. PCR was combined with bioinformatics analysis to detect multilocal sequence typing (MLST) and SCCmec types, to study the genetical correlation between the tested strains. Then, the crystal violet (CV) test and XTT were used to detect biomass content and biofilm activity. Antibiotic susceptibility was tested using a broth dilution method. According to their specific MIC, different concentrations of beta-lactam antibiotics were used to study its effect on biomass content and biofilm viability.<br><br>RESULTS: Strain 10379 carried the icaD, icaBC, and MRSA genes, not the icaA, atl, app, and agr genes, and MLST and SCCmec typing was ST45 and IV, respectively. Strain 121940 carried the icaA, icaD, icaBC, atl, and agr genes, not the aap gene, and MLST and SCCmec typed as ST546 and IV, respectively. This suggested that strains 10379 and 121940 were genotypically very different. Two S. aureus isolates, 10379 and 121940, showed resistance to beta-lactam antibiotics, penicillin, ampicillin, meropenem, streptomycin and kanamycin, some of which promoted the formation of biofilm and biofilm viability at low concentrations.<br><br>CONCLUSION: Despite the large differences in the genetic background of S. aureus 10379 and 121940, some sub-inhibitory concentrations of beta-lactam antibiotics are able to promote biomass and biofilm viability of both two isolates.}, }
@article {pmid36948593, year = {2023}, author = {Wang, M and Wang, J and Li, T and Bao, X and Li, P and Zhang, X and Huang, Q and Meng, X and Li, S}, title = {Penicillin-binding protein 1b encoded by mrcB gene mediates the enhancement of biofilm formation by sub-inhibitory concentrations of cefotaxime in monophasic Salmonella Typhimurium strain SH16SP46.}, journal = {FEMS microbiology letters}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsle/fnad021}, pmid = {36948593}, issn = {1574-6968}, abstract = {Development of cefotaxime-resistance and biofilm formation increase the difficulty to prevent and control the infection and contamination of Salmonella, one of the most important foodborne and zoonotic bacterial pathogen. Our previous study observed that 1/8 MIC of cefotaxime induced the enhancement of biofilm formation and filamentous morphological change by a monophasic Salmonella Typhimurium strain SH16SP46. This study was designed to explore the role of three penicillin-binding proteins (PBPs) in mediating the induction effect of cefotaxime. Three deletion mutants of the genes mrcA, mrcB, and ftsI, encoding the proteins PBP1a, PBP1b, and PBP3, respectively, were constructed using the parental Salmonella strain SH16SP46. Gram staining and scanning electron microscopy showed that these mutants showed normal morphology comparable to the parental strain without cefotaxime treatment. However, under the stress of 1/8 MIC of cefotaxime, the strains WT, ΔmrcA, and ΔftsI, rather than ΔmrcB, exhibited filamentous morphological change. Moreover, cefotaxime treatment significantly enhanced biofilm formation by the strains WT, ΔmrcA, and ΔftsI, but not by the ΔmrcB strain. The complement of mrcB gene in the ΔmrcB strain recovered the enhanced biofilm formation and filamentous morphological change induced by cefotaxime. Our results suggest that PBP1b encoded by mrcB gene may be a binding target of cefotaxime for initiating the effect on Salmonella morphology and biofilm formation. The study will contribute to further understanding of the regulatory mechanism of cefotaxime on Salmonella biofilm formation.}, }
@article {pmid36948321, year = {2023}, author = {Cheng, L and Yang, W and Liang, H and Nabi, M and Li, Y and Wang, H and Hu, J and Chen, T and Gao, D}, title = {Nitrogen removal from mature landfill leachate through enhanced Partial Nitrification-Anammox process in an innovative multi-stage fixed biofilm reactor.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162959}, doi = {10.1016/j.scitotenv.2023.162959}, pmid = {36948321}, issn = {1879-1026}, abstract = {In the current integrated PN/A method/process for mature landfill leachate treatment, microbial inhibition and low nitrogen removal capacity are the big barriers due to high ammonia concentration and low C/N. This study aimed to evaluate the performance of a high-rate nitrogen removal lab-scale reactor, which combines pre-denitrification and Partial Nitrification-Anammox (PN/A) in a multi-stage fixed biofilm reactor (MFBR), for mature landfill leachate treatment. A nitrogen removal efficiency (NRE) of 90.43 % and an average nitrogen removal rate (NRR) of 0.94 kg/m[3]·d were observed at an influent NH+ 4-N concentration of 2274.39 mg/L during the last operational phase. The nitrogen mass balance showed that the nitrogen concentration gradually decreases along the course, and nitrogen was mainly removed in the aerobic chambers, in which Anammox contributed to 86.4 % of the removed nitrogen, while the front anoxic chamber is mainly used to remove NO- 3-N from the recirculation. Redundancy analysis showed that the variation in NH+ 4-N concentration along the course was the main factor affecting microbial community succession, which shows that the reactor configuration enables efficient cooperation and distribution of different microorganisms. Moreover, economic analysis of MFBR process showed that the energy consumption and carbon addition were reduced by 58.9 % and 100 %, respectively. Therefore, the MFBR established in this study, with its new configuration, achieves efficient treatment of landfill leachate in a single reactor and is environmentally friendly, and could be considered as a reference for full-scale landfill leachate treatment.}, }
@article {pmid36947926, year = {2023}, author = {Wu, M and Lai, CY and Wang, Y and Yuan, Z and Guo, J}, title = {Microbial nitrate reduction in propane- or butane-based membrane biofilm reactors under oxygen-limiting conditions.}, journal = {Water research}, volume = {235}, number = {}, pages = {119887}, doi = {10.1016/j.watres.2023.119887}, pmid = {36947926}, issn = {1879-2448}, abstract = {Nitrate contamination has been commonly detected in water environments and poses serious hazards to human health. Previously methane was proposed as a promising electron donor to remove nitrate from contaminated water. Compared with pure methane, natural gas, which not only contains methane but also other short chain gaseous alkanes (SCGAs), is less expensive and more widely available, representing a more attractive electron source for removing oxidized contaminants. However, it remains unknown if these SCGAs can be utilized as electron donors for nitrate reduction. Here, two lab-scale membrane biofilm reactors (MBfRs) separately supplied with propane and butane were operated under oxygen-limiting conditions to test its feasibility of microbial nitrate reduction. Long-term performance suggested nitrate could be continuously removed at a rate of ∼40-50 mg N/L/d using propane/butane as electron donors. In the absence of propane/butane, nitrate removal rates significantly decreased both in the long-term operation (∼2-10 and ∼4-9 mg N/L/d for propane- and butane-based MBfRs, respectively) and batch tests, indicating nitrate bio-reduction was driven by propane/butane. The consumption rates of nitrate and propane/butane dramatically decreased under anaerobic conditions, but recovered after resupplying limited oxygen, suggesting oxygen was an essential triggering factor for propane/butane-based nitrate reduction. High-throughput sequencing targeting 16S rRNA, bmoX and narG genes indicated Mycobacterium/Rhodococcus/Thauera were the potential microorganisms oxidizing propane/butane, while various denitrifiers (e.g. Dechloromonas, Denitratisoma, Zoogloea, Acidovorax, Variovorax, Pseudogulbenkiania and Rhodanobacter) might perform nitrate reduction in the biofilms. Our findings provide evidence to link SCGA oxidation with nitrate reduction under oxygen-limiting conditions and may ultimately facilitate the design of cost-effective techniques for ex-situ groundwater remediation using natural gas.}, }
@article {pmid36947565, year = {2023}, author = {Trindade, SC and Lopes, MPP and Oliveira, TTMC and Silva, MJ and Queiroz, GA and Jesus, TS and Santos, EKN and Carvalho-Filho, PC and Falcão, MML and Miranda, PM and Santos, RPB and Figueiredo, CA and Cruz, &#xc1;A and Seymour, GJ and Gomes-Filho, IS}, title = {Single nucleotide variants in the IL33 and IL1RL1 (ST2) genes are associated with periodontitis and with Aggregatibacter actinomycetemcomitans in the dental plaque biofilm: A putative role in understanding the host immune response in periodontitis.}, journal = {PloS one}, volume = {18}, number = {3}, pages = {e0283179}, pmid = {36947565}, issn = {1932-6203}, mesh = {Humans ; Aggregatibacter actinomycetemcomitans/genetics ; Biofilms ; Cross-Sectional Studies ; *Dental Plaque/genetics ; Immunity ; *Interleukin-1 Receptor-Like 1 Protein/genetics ; *Interleukin-33/genetics ; Nucleotides ; *Periodontitis/genetics ; Polymorphism, Single Nucleotide ; }, abstract = {The Interleukin (IL)-33 is important in several inflammatory diseases and its cellular receptor is the Interleukin 1 receptor-like 1 (IL1RL1), also called suppression of tumorigenicity 2 ligand (ST2L). This study investigated associations between single nucleotide variants (SNVs) in the IL33 gene and in the IL1RL1 (ST2) gene with periodontitis. Additionally, aimed to determine the role of Aggregatibacter actinomycetemcomitans (Aa) relative amount in the subgingival biofilm in these associations. A cross-sectional study was carried out with 506 individuals that answered a structured questionnaire used to collect their health status, socioeconomic-demographic, and behavioral characteristics. Periodontal examination was performed to determine the presence and severity of periodontitis, and subgingival biofilm samples were collected to quantify the relative amount of Aa by real time polymerase chain reaction. Human genomic DNA was extracted from whole blood cells and SNV genotyping was performed. Logistic regression estimated the association measurements, odds ratio (OR), and 95% confidence interval (95%CI), between the IL33 and ST2 genes with periodontitis, and subgroup analyses assessed the relative amount of Aa in these associations. 23% of individuals had periodontitis. Adjusted measurements showed a statistically significant inverse association between two SNVs of the ST2; rs148548829 (C allele) and rs10206753 (G allele). These two alleles together with a third SNV, the rs11693204 (A allele), were inversely associated with moderate periodontitis. One SNV of the IL33 gene also showed a statistically significant inverse association with moderate periodontitis. Nine SNVs of the ST2 gene were inversely associated with the relative amount of Aa. In the high Aa subgroup, there was a direct association between 11 SNVs of the ST2 gene and moderate periodontitis and two SNVs of the ST2 gene and severe periodontitis, and eight SNVs of the ST2 gene and periodontitis. These exploratory findings of genetic variants in IL-33/ST2 axis support the concept that the different tissue responses among individuals with periodontitis may be modulated by the host's genetics, influencing the physiopathology of the disease.}, }
@article {pmid36946779, year = {2023}, author = {Johnston, EL and Zavan, L and Bitto, NJ and Petrovski, S and Hill, AF and Kaparakis-Liaskos, M}, title = {Planktonic and Biofilm-Derived Pseudomonas aeruginosa Outer Membrane Vesicles Facilitate Horizontal Gene Transfer of Plasmid DNA.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0517922}, doi = {10.1128/spectrum.05179-22}, pmid = {36946779}, issn = {2165-0497}, abstract = {Outer membrane vesicles (OMVs) produced by Gram-negative bacteria package various cargo, including DNA that can be transferred to other bacteria or to host cells. OMV-associated DNA has been implicated in mediating horizontal gene transfer (HGT) between bacteria, which includes the dissemination of antibiotic resistance genes within and between bacterial species. Despite the known ability of OMVs to mediate HGT, the mechanisms of DNA packaging into OMVs remain poorly characterized, as does the effect of bacterial growth conditions on the DNA cargo composition of OMVs and their subsequent abilities to mediate HGT. In this study, we examined the DNA content of OMVs produced by the opportunistic pathogen Pseudomonas aeruginosa grown in either planktonic or biofilm conditions. Analysis of planktonic growth-derived OMVs revealed their ability to package and protect plasmid DNA from DNase degradation and to transfer plasmid-encoded antibiotic resistance genes to recipient, antibiotic-sensitive P. aeruginosa bacteria at a greater efficiency than transformation with plasmid alone. Comparisons of planktonic and biofilm-derived P. aeruginosa OMVs demonstrated that biofilm-derived OMVs were smaller but were associated with more plasmid DNA than planktonic-derived OMVs. Additionally, biofilm-derived P. aeruginosa OMVs were more efficient in the transformation of competent P. aeruginosa bacteria, compared to transformations with an equivalent number of planktonic-derived OMVs. The findings of this study highlight the importance of bacterial growth conditions for the packaging of DNA within P. aeruginosa OMVs and their ability to facilitate HGT, thus contributing to the spread of antibiotic resistance genes between P. aeruginosa bacteria. IMPORTANCE Bacterial membrane vesicles (BMVs) mediate interbacterial communication, and their ability to package DNA specifically contributes to biofilm formation, antibiotic resistance, and HGT between bacteria. However, the ability of P. aeruginosa OMVs to mediate HGT has not yet been demonstrated. Here, we reveal that P. aeruginosa planktonic and biofilm-derived OMVs can deliver plasmid-encoded antibiotic resistance to recipient P. aeruginosa. Additionally, we demonstrated that P. aeruginosa biofilm-derived OMVs were associated with more plasmid DNA compared to planktonic-derived OMVs and were more efficient in the transfer of plasmid DNA to recipient bacteria. Overall, this demonstrated the ability of P. aeruginosa OMVs to facilitate the dissemination of antibiotic resistance genes, thereby enabling the survival of susceptible bacteria during antibiotic treatment. Investigating the roles of biofilm-derived BMVs may contribute to furthering our understanding of the role of BMVs in HGT and the spread of antibiotic resistance in the environment.}, }
@article {pmid36946276, year = {2023}, author = {Sójka, O and Keskin, D and van der Mei, HC and van Rijn, P and Gagliano, MC}, title = {Nanogel-based coating as an alternative strategy for biofilm control in drinking water distribution systems.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-14}, doi = {10.1080/08927014.2023.2190023}, pmid = {36946276}, issn = {1029-2454}, abstract = {Biofilm formation and detachment in drinking water distribution systems (DWDS) can lead to several operational issues. Here, an alternative biofilm control strategy of limiting bacterial adhesion by application of a poly(N-isopropylmethacrylamide)-based nanogel coating on DWDS pipe walls was investigated. The nanogel coatings were successfully deposited on surfaces of four polymeric pipe materials commonly applied in DWDS construction. Nanogel-coated and non-coated pipe materials were characterized in terms of their surface hydrophilicity and roughness. Four DWDS relevant bacterial strains, representing Sphingomonas and Pseudomonas, were used to evaluate the anti-adhesive performance of the coating in 4 h adhesion and 24 h biofilm assays. The presence of the nanogel coating resulted in adhesion reduction up to 97%, and biofilm reduction up to 98%, compared to non-coated surfaces. These promising results motivate further investigation of nanogel coatings as a strategy for biofilm prevention in DWDS.}, }
@article {pmid36946046, year = {2023}, author = {Zhang, Z and Liao, H and Yang, M and Hu, C and DU, Y}, title = {[Levofloxacin combined with cellulase can eradicate bacille Calmette-Guerin biofilm infection].}, journal = {Nan fang yi ke da xue xue bao = Journal of Southern Medical University}, volume = {43}, number = {2}, pages = {257-264}, doi = {10.12122/j.issn.1673-4254.2023.02.14}, pmid = {36946046}, issn = {1673-4254}, abstract = {OBJECTIVE: To investigate the inhibitory effects of levofloxacin (LEV) combined with cellulase against bacille CalmetteGuerin (BCG) biofilms in vitro.<br><br>METHODS: The mature growth cycle of BCG biofilms was determined using the XTT method and crystal violet staining. BCG planktonic bacteria and BCG biofilms were treated with different concentrations of LEV and cellulose alone or jointly, and the changes in biofilm biomass were quantified with crystal violet staining. The mature BCG biofilm was then treated with cellulase alone for 24 h, and after staining with SYTO 9 and Calcofluor White Stain, the number of viable bacteria and the change in cellulose content in the biofilm were observed with confocal laser scanning microscopy. The structural changes of the treated biofilm were observed under scanning electron microscopy.<br><br>RESULTS: The MIC, MBC and MBEC values of LEV determined by broth microdilution method were 4 &#x3bc;g/mL, 8 &#x3bc;g/mL and 1024 &#x3bc;g/mL, respectively. The combined treatment with 1/4&#xd7;MIC LEV and 2.56, 5.12 or 10.24 U/mL cellulase resulted in a significant reduction in biofilm biomass (P < 0.001). Cellulase treatments at the concentrations of 10.24, 5.12 and 2.56 U/mL all produced significant dispersion effects on mature BCG biofilms (P < 0.001).<br><br>CONCLUSION: LEV combined with cellulose can effectively eradicate BCG biofilm infections, suggesting the potential of glycoside hydrolase therapy for improving the efficacy of antibiotics against biofilmassociated infections caused by Mycobacterium tuberculosis.}, }
@article {pmid36944677, year = {2023}, author = {Brothers, KM and Parker, DM and Taguchi, M and Ma, D and Mandell, JB and Thurlow, LL and Byrapogu, VC and Urish, KL}, title = {Dose optimization in surgical prophylaxis: sub-inhibitory dosing of vancomycin increases rates of biofilm formation and the rates of surgical site infection.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {4593}, pmid = {36944677}, issn = {2045-2322}, support = {NIAMS K08AR071494/AR/NIAMS NIH HHS/United States ; NCATS KL2TR0001856/TR/NCATS NIH HHS/United States ; }, abstract = {Antibiotic stewardship is viewed as having great public health benefit with limited direct benefit to the patient at the time of administration. The objective of our study was to determine if inappropriate administration of antibiotics could create conditions that would increase the rates of surgical infection. We hypothesized that sub-MIC levels of vancomycin would increase Staphylococcus aureus growth, biofilm formation, and rates of infection. S. aureus MRSA and MSSA strains were used for all experiments. Bacteria were grown planktonically and monitored using spectrophotometry. Quantitative agar culture was used to measure planktonic and biofilm bacterial burden. A mouse abscess model was used to confirm phenotypes in vivo. In the planktonic growth assay, increases in bacterial burden at ¼ MIC vancomycin were observed in USA300 JE2 by 72 h. Similar findings were observed with ½ MIC in Newman and SH1000. For biofilm formation, USA300 JE2 at ¼ and ½ MIC vancomycin increased biofilm formation by approximately 1.3- and 2.3-fold respectively at 72 h as compared to untreated controls. Similar findings were observed with Newman and SH1000 with a 2.4-fold increase in biofilm formation at ½ MIC vancomycin. In a mouse abscess model, there was a 1.2-fold increase with sub-MIC vancomycin at 3 days post infection. Our study showed that Sub-optimal vancomycin dosing promoted S. aureus planktonic growth and biofilm formation, phenotypic measures of bacterial virulence. This phenotype induced by sub-MIC levels of vancomycin was also observed to increase rates of infection and pathogenesis in our mouse model. Risks of exposure to sub-MIC concentrations with vancomycin in surgical procedures are greater as there is decreased bioavailability in tissue in comparison to other antibiotics. This highlights the importance of proper antibiotic selection, stewardship, and dosing for both surgical prophylaxis and treatment of infection.}, }
@article {pmid36944321, year = {2023}, author = {Kognou, ALM and Chio, C and Khatiwada, JR and Shrestha, S and Chen, X and Zhu, Y and Ngono Ngane, RA and Agbor Agbor, G and Jiang, ZH and Xu, CC and Qin, W}, title = {Characterization of Potential Virulence, Resistance to Antibiotics and Heavy Metals, and Biofilm-forming Capabilities of Soil Lignocellulolytic Bacteria.}, journal = {Microbial physiology}, volume = {}, number = {}, pages = {}, doi = {10.1159/000530228}, pmid = {36944321}, issn = {2673-1673}, abstract = {Soil bacteria participate in self-immobilization processes for survival, persistence and producing virulence factors in some niches or hosts through their capacities of autoaggregation, cell surface hydrophobicity, biofilm formation, and antibiotic and heavy metal resistance. This study investigated potential virulence, antibiotics and heavy metals resistance, solvent adhesion, and biofilm-forming capabilities of six cellulolytic bacteria isolated from soil samples: Paenarthrobacter sp. MKAL1, Hymenobacter sp. MKAL2, Mycobacterium sp. MKAL3, Stenotrophomonas sp. MKAL4, Chryseobacterium sp. MKAL5 and Bacillus sp. MKAL6. Strains were subjected to phenotypic methods, including heavy metal and antibiotic susceptibility and virulence factors (protease, lipase, capsule production, autoaggregation, hydrophobicity and biofilm formation). The effect of ciprofloxacin was also investigated on bacterial susceptibility over time, cell membrane and biofilm formation. Strains MKAL2, MKAL5 and MKAL6 exhibited protease and lipase activities, while only MKAL6 produced capsules. All strains were capable of aggregating, forming biofilm and adhering to solvents. Strains tolerated high amounts of chromium, lead, zinc, nickel and manganese and were resistant to lincomycin. Ciprofloxacin exhibited bactericidal activity against these strains. Although the phenotypic evaluation of virulence factors of bacteria can indicate their pathogenic nature, an in-depth genetic study of virulence, antibiotic and heavy metal resistance genes is required.}, }
@article {pmid36942961, year = {2023}, author = {Archambault, L and Koshy-Chenthittayil, S and Thompson, A and Dongari-Bagtzoglou, A and Laubenbacher, R and Mendes, P}, title = {Corrected and Republished from: "Understanding Lactobacillus paracasei and Streptococcus oralis Biofilm Interactions through Agent-Based Modeling".}, journal = {mSphere}, volume = {}, number = {}, pages = {e0065622}, doi = {10.1128/msphere.00656-22}, pmid = {36942961}, issn = {2379-5042}, abstract = {As common commensals residing on mucosal tissues, Lactobacillus species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other organisms in those environments. In this study we used a combination of in vitro imaging of live biofilms and computational modeling to explore biofilm interactions between Streptococcus oralis, an accessory pathogen in oral candidiasis, and Lactobacillus paracasei, an organism with known probiotic properties. A computational agent-based model was created where the two species interact only by competing for space, oxygen, and glucose. Quantification of bacterial growth in live biofilms indicated that S. oralis biomass and cell numbers were much lower than predicted by the model. Two subsequent models were then created to examine more complex interactions between these species, one where L. paracasei secretes a surfactant and another where L. paracasei secretes an inhibitor of S. oralis growth. We observed that the growth of S. oralis could be affected by both mechanisms. Further biofilm experiments support the hypothesis that L. paracasei may secrete an inhibitor of S. oralis growth, although they do not exclude that a surfactant could also be involved. This contribution shows how agent-based modeling and experiments can be used in synergy to address multiple-species biofilm interactions, with important roles in mucosal health and disease. IMPORTANCE We previously discovered a role of the oral commensal Streptococcus oralis as an accessory pathogen. S. oralis increases the virulence of Candida albicans infections in murine oral candidiasis and epithelial cell models through mechanisms which promote the formation of tissue-damaging biofilms. Lactobacillus species have known inhibitory effects on biofilm formation of many microbes, including Streptococcus species. Agent-based modeling has great advantages as a means of exploring multifaceted relationships between organisms in complex environments such as biofilms. Here, we used an iterative collaborative process between experimentation and modeling to reveal aspects of the mostly unexplored relationship between S. oralis and L. paracasei in biofilm growth. The inhibitory nature of L. paracasei on S. oralis in biofilms may be exploited as a means of preventing or alleviating mucosal fungal infections.}, }
@article {pmid36942960, year = {2023}, author = {Archambault, L and Koshy-Chenthittayil, S and Thompson, A and Dongari-Bagtzoglou, A and Laubenbacher, R and Mendes, P}, title = {Correction for Archambault et al., "Understanding Lactobacillus paracasei and Streptococcus oralis Biofilm Interactions through Agent-Based Modeling".}, journal = {mSphere}, volume = {}, number = {}, pages = {e0064822}, doi = {10.1128/msphere.00648-22}, pmid = {36942960}, issn = {2379-5042}, }
@article {pmid36942200, year = {2023}, author = {Alharbi, MS and Alshehri, FA and Alobaidi, AS and Alrowis, R and Alshibani, N and Niazy, AA}, title = {High molecular weight hyaluronic acid reduces the growth and biofilm formation of the oral pathogen Porphyromonas gingivalis.}, journal = {The Saudi dental journal}, volume = {35}, number = {2}, pages = {141-146}, pmid = {36942200}, issn = {1013-9052}, abstract = {BACKGROUND: Porphyromonas gingivalis (P. gingivalis) is viewed as a keystone microorganism in the pathogenesis of periodontal and peri-implant diseases. Hyaluronic acid (HA) is believed to exert antimicrobial activity. The aim of this study is to assess the in-vitro growth and biofilm formation of P. gingivalis under HA and compare the effect of HA to that of azithromycin (AZM) and chlorhexidine (CHX).<br><br>MATERIALS AND METHODS: In each material, the minimum inhibitory concentration (MIC), 50% MIC, 25% MIC, and 12.5% MIC were tested. The growth of P. gingivalis was evaluated by absorbance spectrophotometry after 48&#xa0;h. A biofilm inhibition assay was performed on a 72-hour culture by washing planktonic bacterial cells, fixing and staining adherent cells, and measuring the variation in stain concentrations relative to the untreated control using absorbance spectrophotometry.<br><br>RESULTS: The results show that the overall growth of P. gingivalis after 48&#xa0;h was 0.048&#xa0;&#xb1;&#xa0;0.030, 0.008&#xa0;&#xb1;&#xa0;0.013, and 0.073&#xa0;&#xb1;&#xa0;0.071 under HA, AZM, and CHX, respectively, while the untreated control reached 0.236&#xa0;&#xb1;&#xa0;0.039. HA was also able to significantly reduce the biofilm formation of P. gingivalis by 64.30&#xa0;% &#xb1; 22.39, while AZM and CHX reduced biofilm formation by 91.16&#xa0;%&#xb1;12.58 and 88.35&#xa0;%&#xb1;17.11, respectively.<br><br>CONCLUSIONS: High molecular-weight HA significantly inhibited the growth of P. gingivalis. The overall effect of HA on the growth of P. gingivalis was similar to that of CHX but less than that of AZM. HA was also able to significantly reduce the biofilm formation of P. gingivalis. However, the ability of HA to prevent the biofilm formation of P. gingivalis was generally less than that of both AZM and CHX.}, }
@article {pmid36938129, year = {2022}, author = {Mohanta, YK and Chakrabartty, I and Mishra, AK and Chopra, H and Mahanta, S and Avula, SK and Patowary, K and Ahmed, R and Mishra, B and Mohanta, TK and Saravanan, M and Sharma, N}, title = {Nanotechnology in combating biofilm: A smart and promising therapeutic strategy.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1028086}, pmid = {36938129}, issn = {1664-302X}, abstract = {Since the birth of civilization, people have recognized that infectious microbes cause serious and often fatal diseases in humans. One of the most dangerous characteristics of microorganisms is their propensity to form biofilms. It is linked to the development of long-lasting infections and more severe illness. An obstacle to eliminating such intricate structures is their resistance to the drugs now utilized in clinical practice (biofilms). Finding new compounds with anti-biofilm effect is, thus, essential. Infections caused by bacterial biofilms are something that nanotechnology has lately shown promise in treating. More and more studies are being conducted to determine whether nanoparticles (NPs) are useful in the fight against bacterial infections. While there have been a small number of clinical trials, there have been several in vitro outcomes examining the effects of antimicrobial NPs. Nanotechnology provides secure delivery platforms for targeted treatments to combat the wide range of microbial infections caused by biofilms. The increase in pharmaceuticals' bioactive potential is one of the many ways in which nanotechnology has been applied to drug delivery. The current research details the utilization of several nanoparticles in the targeted medication delivery strategy for managing microbial biofilms, including metal and metal oxide nanoparticles, liposomes, micro-, and nanoemulsions, solid lipid nanoparticles, and polymeric nanoparticles. Our understanding of how these nanosystems aid in the fight against biofilms has been expanded through their use.}, }
@article {pmid36937307, year = {2023}, author = {Zhu, X and Dou, F and Long, M and Wang, X and Liu, W and Li, F and Liu, T and Wu, Y}, title = {Electron shuttle-dependent biofilm formation and biocurrent generation: Concentration effects and mechanistic insights.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1070800}, pmid = {36937307}, issn = {1664-302X}, abstract = {INTRODUCTION: Electron shuttles (ESs) play a key role in extracellular electron transfer (EET) in Shewanella oneidensis MR-1. However, the quantification relationship between ES concentration, biofilm formation, and biocurrent generation has not been clarified.<br><br>METHODS: In this study, 9,10-anthraquinone-2-sulfonic acid (AQS)-mediated EET and biofilm formation were evaluated at different AQS concentrations in bioelectrochemical systems (BESs) with S. oneidensis MR-1.<br><br>RESULTS AND DISCUSSION: Both the biofilm biomass (9- to 17-fold) and biocurrent (21- to 80-fold) were substantially enhanced by exogenous AQS, suggesting the dual ability of AQS to promote both biofilm formation and electron shuttling. Nevertheless, biofilms barely grew without the addition of exogenous AQS, revealing that biofilm formation by S. oneidensis MR-1 is highly dependent on electron shuttling. The biofilm growth was delayed in a BES of 2,000 &#x3bc;M AQS, which is probably because the redundant AQS in the bulk solution acted as a soluble electron acceptor and delayed biofilm formation. In addition, the maximum biocurrent density in BESs with different concentrations of AQS was fitted to the Michaelis-Menten equation (R [2] = 0.97), demonstrating that microbial-catalyzed ES bio-reduction is the key limiting factor of the maximum biocurrent density in BESs. This study provided a fundamental understanding of ES-mediated EET, which could be beneficial for the enrichment of electroactive biofilms, the rapid start-up of microbial fuel cells (MFCs), and the design of BESs for wastewater treatment.}, }
@article {pmid36937277, year = {2023}, author = {Xie, J and Zhang, H and Li, Y and Li, H and Pan, Y and Zhao, Y and Xie, Q}, title = {Transcriptome analysis of the biofilm formation mechanism of Vibrio parahaemolyticus under the sub-inhibitory concentrations of copper and carbenicillin.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1128166}, pmid = {36937277}, issn = {1664-302X}, abstract = {Biofilm formation of Vibrio parahaemolyticus enhanced its tolerance to the environment, but caused many serious problems to food safety and human health. In this paper, the effects of copper and carbenicillin (CARB) stress on the formation of the biofilms of V. parahaemolyticus organisms were studied, and RNA sequencing technology was used to compare the differences in transcriptome profiles of the biofilm-related genes of V. parahaemolyticus organisms under different sub-inhibitory stresses. The results proved that V. parahaemolyticus had a large growth difference under the two stresses, copper and CARB at 1/2 minimal inhibitory concentration (MIC), and it could form a stable biofilm under both stress conditions. The amount of biofilm formed under CARB stress was significantly higher than that of copper stress (p < 0.05). Based on the analysis of transcriptome sequencing results 323, 1,550, and 1,296 significantly differential expressed genes were identified in the three treatment groups namely 1/2 MIC CARB, Cu[2+], and Cu[2+]+CARB. Through COG annotation, KEGG metabolic pathway analysis and gene expression analysis related to biofilm formation, the functional pathways of transcriptome changes affecting V. parahaemolyticus were different in the three treatment groups, and the CARB treatment group was significantly different from the other two groups. These differences indicated that the ABC transport system, two-component system and quorum sensing were all involved in the biofilm formation of the V. parahaemolytic by regulating flagellar motility, extracellular polysaccharides and extracellular polymer synthesis. Exploring the effects of different stress conditions on the transcriptome of V. parahaemolyticus could provide a basis for future research on the complex network system that regulates the formation of bacterial biofilms.}, }
@article {pmid36936302, year = {2023}, author = {Mao, T and Chai, B and Xiong, Y and Wang, H and Nie, L and Peng, R and Li, P and Yu, Z and Fang, F and Gong, X}, title = {In Vitro Inhibition of Growth, Biofilm Formation, and Persisters of Staphylococcus aureus by Pinaverium Bromide.}, journal = {ACS omega}, volume = {8}, number = {10}, pages = {9652-9661}, pmid = {36936302}, issn = {2470-1343}, abstract = {Biofilm or persister cells formed by Staphylococcus aureus are closely related to pathogenicity. However, no antimicrobials exist to inhibit biofilm formation or persister cells induced by S. aureus in clinical practice. This study found that pinaverium bromide had antibacterial activity against S. aureus, with the MIC50/MIC90 at 12.5/25 μM, respectively. Pinaverium bromide (at 4 × MIC) showed a rapid bactericidal effect on S. aureus planktonic cells, and it was more effective (at least 1-log10 cfu/mL) than linezolid, vancomycin, and ampicillin at 4 h of the time-killing test. Pinaverium bromide (at 10 × MIC) significantly inhibited the formation of S. aureus persister cells (at least 3-log10 cfu/mL) than linezolid, vancomycin, and ampicillin at 24, 48, 72, 96, and 120 h of the time-killing test. Biofilm formation and adherent cells of S. aureus isolates were significantly inhibited by pinaverium bromide (at 1/2 or 1/4 × MICs). The fluorescence intensity of the membrane polarity of S. aureus increased with the treatment of pinaverium bromide (≥1 × MIC), and the MICs of pinaverium bromide increased by 4 times with the addition of cell membrane phospholipids, phosphatidyl glycerol and cardiolipin. The cell viabilities of human hepatocellular carcinoma cells HepG2 and Huh7, mouse monocyte-macrophage cells J774, and human hepatic stellate cells LX-2 were slightly inhibited by pinaverium bromide (<50 μM). There were 54 different abundance proteins detected in the pinaverium bromide-treated S. aureus isolate by proteomics analysis, of which 33 proteins increased, whereas 21 proteins decreased. The abundance of superoxide dismutase sodM and ica locus proteins icaA and icaB decreased. While the abundance of global transcriptional regulator spxA and Gamma-hemolysin component B increased. In conclusion, pinaverium bromide had an antibacterial effect on S. aureus and significantly inhibited the formation of biofilm and persister cells of S. aureus.}, }
@article {pmid36935141, year = {2023}, author = {Arismendi, D and Vera, I and Ahumada, I and Richter, P}, title = {A thin biofilm of chitosan as a sorptive phase in the rotating disk sorptive extraction of triclosan and methyl triclosan from water samples.}, journal = {Analytica chimica acta}, volume = {1252}, number = {}, pages = {341053}, doi = {10.1016/j.aca.2023.341053}, pmid = {36935141}, issn = {1873-4324}, mesh = {Animals ; *Triclosan/analysis ; *Chitosan ; Water ; *Water Pollutants, Chemical/analysis ; }, abstract = {The features and nature of the sorptive phase may be the stage that determines the scope of microextraction techniques. In search of new alternatives, materials of natural origin have recently been explored to establish greener analytical strategies. Based on that search, this research proposes the use of chitosan as a sorptive phase, which was assessed in the rotating disk sorptive extraction of emerging contaminants from aqueous systems. Chitosan is a biopolymer of animal origin that is usually found in the shells of crustaceans. The main characteristic of this material is the presence of a high number of nitrogenous groups, which gives it high reactivity, but its main disadvantage is associated with its high swelling capacity. In this research, chitosan was crosslinked with a low concentration of glutaraldehyde to form thin films that were easily immobilized on the surface of the rotating disk. The main advantage of this modification is the considerable decrease in the swelling capacity, which prevents loss and rupture of the sorbent during high rotation of the disk. In addition, it not only improved the physical characteristics of chitosan but also increased its extraction capacity. With regard to its use as a sorptive phase, all the variables associated with the microextraction of the analytes were studied, and optimal variables were found to be: pH 4, 20% NaCl (salting out effect), 30-45 min as equilibrium time and elution of analytes with a mixture of methanol:ethyl acetate (1:1). Validation of the methodology for the determination of methyl triclosan and triclosan was carried out, and relative recoveries between 89 and 96% and relative standard deviations less than 14% were found. The detection limits were 0.11 and 0.20 μg L[-1], respectively. Through its application in real samples (natural and residual waters), triclosan was quantified between 0.7 and 1.3 μg L[-1]. Finally, the "green" properties of the phase were evaluated, demonstrating that it is reusable for at least three cycles and biodegradable. Compared to its efficiency with a commercial phase (in this case, the styrene divinyl benzene phase), the proposed biosorbent provided a similar and even higher sorptive capacity (depending on the analyte).}, }
@article {pmid36934281, year = {2023}, author = {Bayani, M and Raisolvaezin, K and Almasi-Hashiani, A and Mirhoseini, SH}, title = {Bacterial biofilm prevalence in dental unit waterlines: a systematic review and meta-analysis.}, journal = {BMC oral health}, volume = {23}, number = {1}, pages = {158}, pmid = {36934281}, issn = {1472-6831}, abstract = {BACKGROUNDS: Numerous studies have shown that dental unit water lines (DUWLs) are often contaminated by a wide range of micro-organisms (bacteria, fungi, protozoa) and various prevalence have been reported for it in previous studies. Therefore, this review study aims to describe the prevalence of bacterial biofilm contamination of DUWLs.<br><br>METHODS: This is a systematic review and meta-analysis in which the related keywords in different international databases, including Medline (via PubMed) and Scopus were searched. The retrieved studies were screened and the required data were extracted from the included studies. Three standard methods including American Dental Association (ADA), The Center for Disease Control and Prevention (CDC) and contaminated&#x2009;>&#x2009;100&#xa0;CFU/ml(C-100) standards were used to assess the bacterial biofilm contamination of DUWLs. All studies that calculated the prevalence of bacterial biofilm contamination of DUWLs, and English full-text studies were included in the meta-analysis. Studies that did not have relevant data or used unusual laboratory methods were excluded. Methodological risk of bias was assessed by a related checklist and finally, the data were pooled by fixed or random-effect models.<br><br>RESULTS: Seven hundred and thirty-six studies were identified and screened and 26 related studies were included in the meta-analysis. The oldest included study was published in 1976 and the most recent study was published in 2020. According to the ADA, CDC and C-100 standards, the prevalence of bacterial contamination was estimated to be 85.0% (95% confidence interval (CI): 66.0-94.0%), 77.0% (95%CI: 66.0-85.0%) and 69.0% (95%CI: 67.0-71.0%), respectively. The prevalence of Legionella Pneumophila and Pseudomonas Aeruginosa in DUWLs was estimated to be 12.0% (95%CI: 10.0-14.0%) and 8.0% (95%CI: 2.0-24.0%), respectively.<br><br>CONCLUSION: The results of this review study suggested a high prevalence of bacterial biofilm in DUWLs; therefore, the use of appropriate disinfecting protocol is recommended to reduce the prevalence of contamination and reduce the probable cross-infection.}, }
@article {pmid36933573, year = {2023}, author = {Yang, J and Sim, YB and Moon Kim, S and Joo, HH and Jung, JH and Kim, SH}, title = {Enhanced Continuous Biohydrogen Production using Dynamic Membrane with Conductive Biofilm Supporter.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128900}, doi = {10.1016/j.biortech.2023.128900}, pmid = {36933573}, issn = {1873-2976}, abstract = {The present study investigated the effect of a conductive biofilm supporter on continuous production of biohydrogen in a dynamic membrane bioreactor (DMBR). Two lab-scale DMBRs were operated: one with a nonconductive polyester mesh (DMBR I) and the other with a conductive stainless-steel mesh (DMBR II). The highest average hydrogen productivity and the yield were 16.8% greater in DMBR II than in DMBR I, with values of 51.64 ± 0.66 L/L-d and 2.01 ± 0.03 mol H2/mol hexoseconsumed, respectively. The improved hydrogen production was concurrent with a higher NADH/NAD[+] ratio and a lower ORP (Oxidation-reduction potential). Metabolic flux analysis implied that the conductive supporter promoted H2-producing acetogenesis and repressed competitive NADH-consuming pathways, such as homoacetogenesis and lactate production. Microbial community analysis revealed that electroactive Clostridium sp. were the dominant H2 producers in DMBR II. Conclusively, conductive meshes may be useful as biofilm supporters of dynamic membranes during H2 production for selectively enhancing H2-producing pathways.}, }
@article {pmid36933360, year = {2023}, author = {Wu, J and McAuliffe, O and O'Byrne, CP}, title = {Trehalose transport occurs via TreB in Listeria monocytogenes and it influences biofilm development and acid resistance.}, journal = {International journal of food microbiology}, volume = {394}, number = {}, pages = {110165}, doi = {10.1016/j.ijfoodmicro.2023.110165}, pmid = {36933360}, issn = {1879-3460}, abstract = {Listeria monocytogenes is a pathogenic bacterium that can inhabit a diverse range of environmental niches. This is largely attributed to the high proportion of carbohydrate-specific phosphotransferase system (PTS) genes in its genome. Carbohydrates can be assimilated as sources of energy but additionally they can serve as niche-specific cues for L. monocytogenes to shape its global gene expression, in order to cope with anticipated stresses. To examine carbon source utilization among wild L. monocytogenes isolates and to understand underlying molecular mechanisms, a diverse collection of L. monocytogenes strains (n = 168) with whole genome sequence (WGS) data available was screened for the ability to grow in chemically defined media with different carbon sources. The majority of the strains grew in glucose, mannose, fructose, cellobiose, glycerol, trehalose, and sucrose. Maltose, lactose, and rhamnose supported slower growth while ribose did not support any growth. In contrast to other strains, strain1386, which belonged to clonal complex 5 (CC5), was unable to grow on trehalose as a sole carbon source. WGS data revealed that it carried a substitution (N352K) in a putative PTS EIIBC trehalose transporter, TreB, while this asparagine residue is conserved in other strains in this collection. Spontaneous mutants of strain 1386 that could grow in trehalose were found to harbour a reversion of the substitution in TreB. These results provide genetic evidence that TreB is responsible for trehalose uptake and that the N352 residue is essential for TreB activity. Moreover, reversion mutants also restored other unusual phenotypes that strain 1386 displayed, i.e. altered colony morphology, impaired biofilm development, and reduced acid resistance. Transcriptional analysis at stationary phase with buffered BHI media revealed that trehalose metabolism positively influences the transcription of genes encoding amino acid-based acid resistance mechanisms. In summary, our results demonstrated that N352 is key to the function of the sole trehalose transporter TreB in L. monocytogenes and suggest that trehalose metabolism alters physiology to favour biofilm development and acid stress resistance. Moreover, since strain 1386 is among the strains recommended by the European Union Reference Laboratory for conducting food challenge studies in order to determine whether or not L. monocytogenes can grow in food, these findings have important implications for food safety.}, }
@article {pmid36933236, year = {2023}, author = {Chen, Q and Qi, M and Shi, F and Liu, C and Shi, Y and Sun, Y and Bai, X and Wang, L and Sun, X and Dong, B and Li, C}, title = {Novel Twin-Crystal Nanosheets with MnO2 Modification to Combat Bacterial Biofilm against Periodontal Infections via Multipattern Strategies.}, journal = {Advanced healthcare materials}, volume = {}, number = {}, pages = {e2300313}, doi = {10.1002/adhm.202300313}, pmid = {36933236}, issn = {2192-2659}, abstract = {Nowadays the multifunctional approaches to kill oral bacteria based on various nanocomposites have made great progress against periodontal infections, while the material structure and its functional integration are still insufficient. Herein, we proposed a therapeutic strategy of chemodynamical therapy (CDT) and photothermal therapy (PTT) in monocrystals to effectively enhance the synergistic treatment. The CuS/MnS@MnO2 consisting of hexagonal CuS/MnS nano-twin-crystal with a shell layer of MnO2 was developed. In this nanosystem, the purpose of synergistic treatment of periodontitis by combining PTT/CDT has been achieved within CuS/MnS monocrystal, where CuS served to achieve photothermal conversion, dissipate the biofilm and transfer the heat in situ to the integrated MnS, thus promoting the Mn[2+] -mediated CDT process. Meanwhile, the CDT process could generate the highly toxic hydroxyl radical to destroy extracellular DNA by utilization of endogenous H2 O2 produced by Streptococci in oral biofilm, cooperating with PTT to dissipate bacterial biofilm. With the design of outer shell of MnO2 , the selective bacteria-killing can be realized by producing oxygen which can protect the periodontal non-pathogenic aerobic bacteria and threatened the survival of anaerobic pathogens Therefore, such design via multipattern strategies to combat microorganisms would provide a bright prospect for the clinical treatment of bacterial infections. This article is protected by copyright. All rights reserved.}, }
@article {pmid36931893, year = {2023}, author = {Wang, F and Yuan, J and Wang, X and Xuan, H}, title = {Antibacterial and anti-biofilm activities of chinese Propolis essential oil microemulsion against Streptococcus mutans.}, journal = {Journal of applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jambio/lxad056}, pmid = {36931893}, issn = {1365-2672}, abstract = {AIMS: To solve the shortcomings of poor solubility, easy volatilization and decomposition, propolis essential oil microemulsion (PEOME) was prepared. The antibacterial, anti-biofilm activities and action mechanism of PEOME against Streptococcus mutans was analyzed.<br><br>METHODS: PEOME was prepared using anhydrous ethanol and Tween-80 as the cosurfactant and surfactant respectively. The antibacterial activity of PEOME against Streptococcus mutans was evaluated using the agar disk-diffusion method and broth microdilution method. The effects of PEOME on S. mutans biofilm was detected through the assays of crystal violet (CV), XTT reduction, lactic dehydrogenase (LDH) and calcium ions leaking, live/dead staining and scanning electron microscopy (SEM). And the anti-biofilm mechanism of PEOME was elaborated by the assays of extracellular polysaccharide (EPS) production and glucosyltransferase (GTF) activity.<br><br>RESULTS: The inhibition zone diameter (DIZ) of PEOME against S. mutans was 31&#xa0;mm, while the minimal inhibitory concentration (MIC) was 2.5&#xa0;&#xb5;L mL-1. CV and XTT assays showed that PEOME could prevent fresh biofilm formation and disrupt preformed biofilm through decreasing the activities and biomass of biofilm. The leaking assays for LDH and calcium ions, as well as the live/dead staining assay, indicated that PEOME was able to damage the integrity of bacterial cell membranes within the biofilm. SEM revealed that PEOME had a noticeable inhibitory effect on bacterial adhesion and aggregation through observing the overall structure of biofilm. The assays of EPS production and GTF activity suggested that PEOME could reduce EPS production by inhibiting the activity of GTFs, thus showing an anti-biofilm effect.<br><br>CONCLUSIONS: The significant antibacterial and anti-biofilm activities against S. mutans of PEOME meant that PEOME has great potential to be developed as a drug to prevent and cure dental caries caused by S. mutans.}, }
@article {pmid36931368, year = {2023}, author = {Sindelo, A and Sen, P and Nyokong, T}, title = {Photoantimicrobial activity of Schiff-base Morpholino phthalocyanines against drug resistant micro-organisms in their planktonic and biofilm forms.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103519}, doi = {10.1016/j.pdpdt.2023.103519}, pmid = {36931368}, issn = {1873-1597}, abstract = {Antimicrobial photodynamic inactivation (aPDI) is an alternative treatment for the eradication of drug-resistant micro-organisms. One of the advantages of this technique, it that there is no possibility of microbial resistance. Hence, herein, the preparation and characterization of novel neutral and cationic morpholine containing Schiff base phthalocyanines are reported. The cationic complexes (4 and 5) gave moderate singlet oxygen quantum yields (ΦΔ) of ∼0.2 in aqueous media. Conversely, the neutral complexes generated very low ΦΔ values making them very poor candidates for antimicrobial studies. The cationic phthalocyanines showed excellent photodynamic activity against planktonic cells of all micro-organisms (Candida albicans, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella enterica subspecies enterica serovar Choleraesuis, vancomycin-resistant E. faecium, and methicillin-resistant Staphylococcus aureus). The efficiency of aPDI was shown to be both concentration and light-dose-dependent. Mono biofilms were susceptible when treated with 200 µM of cationic Pcs at 108 J/cm[2]. However, ∼10% of the mixed biofilm survived after treatment.}, }
@article {pmid36930448, year = {2023}, author = {Yazıcı, BC and Bakhedda, N and Akçelik, N}, title = {Effect of nisin and p-coumaric acid on autoinducer-2 activity, biofilm formation, and sprE expression of Enterococcus faecalis.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {36930448}, issn = {1678-4405}, abstract = {Quorum sensing (QS) is an inter- and intracellular communication mechanism that regulates gene expression in response to population size. Autoinducer-2 (AI-2) signaling is a QS signaling molecule common to both Gram-negative and Gram-positive bacteria. Enterococcus faecalis is one of the leading causes of nosocomial infections worldwide. There has been an increasing interest in controlling infectious diseases through targeting the QS mechanism using natural compounds. This study aimed to investigate the effect of nisin and p-coumaric acid (pCA), on biofilm formation and AI-2 signaling in E. faecalis. Their effect on the expression of the QS-regulated virulence encoding gene sprE was also investigated. Nisin exhibited a MIC ranging from 0.25 to 0.5 mg/mL, while the MIC of pCA was 1 mg/mL. The luminescence-based response of the reporter strain Vibrio harveyi BB170 was used to determine AI-2 activity in E. faecalis strains. Nisin was not effective in inhibiting AI-2 activity, while pCA reduced AI-2 activity by ≥ 60%. Moreover, pCA and nisin combination showed higher inhibitory effect on biofilm formation of E. faecalis, compared to the treatment of pCA or nisin alone. qRT-PCR analysis showed that nisin alone and the combination of nisin and pCA, at their MIC values, led to a 32.78- and 40.22-fold decrease in sprE gene expression, respectively, while pCA alone did not have a significant effect. Considering the demand to explore new therapeutic avenues for infectious bacteria, this study was the first to report that pCA can act like a quorum sensing inhibitor (QSI) against AI-2 signaling in E. faecalis.}, }
@article {pmid36930446, year = {2023}, author = {Baghiat Esfahani, M and Khodavandi, A and Alizadeh, F and Bahador, N}, title = {Biofilm-associated genes as potential molecular targets of nano-Fe3O4 in Candida albicans.}, journal = {Pharmacological reports : PR}, volume = {}, number = {}, pages = {}, pmid = {36930446}, issn = {2299-5684}, abstract = {BACKGROUND: There are few effective treatments for Candida biofilm-associated infections. The present study demonstrated changes in the expression of biofilm-associated genes in Candida albicans treated with magnetic iron oxide nanoparticles (denoted as nano-Fe3O4).<br><br>METHODS: Nano-Fe3O4 was biologically synthesized using Bacillus licheniformis, Bacillus cereus, and Fusarium oxysporum. Additionally, the&#xa0;biologically synthesized nano-Fe3O4 was characterized by visual observation; ultraviolet-visible spectroscopy, scanning electron microscopy, X-ray diffraction spectroscopy, and Fourier transform infrared spectroscopy. The biologically synthesized nano-Fe3O4 was tested for growth and biofilm formation in&#xa0;C. albicans. Furthermore, quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to study the inhibition of biofilm-associated genes in C. albicans treated with nano-Fe3O4.<br><br>RESULTS: The production of biologically synthesized nano-Fe3O4 was confirmed using extensive characterization methods. The nano-Fe3O4 inhibited growth and biofilm formation. Nano-Fe3O4 exhibited growth inhibition with minimum inhibition concentrations (MICs) of 50 to 200&#xa0;&#x3bc;g&#xa0;mL[-1]. The anti-biofilm effects of nano-Fe3O4 were shown by 2,3-bis (2-methoxy-4-nitro-5 sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay, crystal violet staining, and light field microscopy. The gene expression results showed that the downregulation of&#xa0;BCR1, ALS1, ALS3, HWP1, and ECE1 genes inhibited the biofilm formation in&#xa0;C. albicans. ALS1 reduction was greater than others, with downregulation of 1375.83-, 1178.71-, and 768.47-fold at 2&#x2009;&#xd7;&#x2009;MIC, 1&#x2009;&#xd7;&#x2009;MIC, and &#xbd;&#x2009;&#xd7;&#x2009;MIC of nano-Fe3O4, respectively.<br><br>CONCLUSION: Biofilm-associated genes as potential molecular targets of nano-Fe3O4 in C. albicans may be an effective novel treatment strategy for biofilm-associated infections.}, }
@article {pmid36929684, year = {2023}, author = {Du, X and Ma, M and Zhang, Y and Yu, X and Chen, L and Zhang, H and Meng, Z and Jia, X and Chen, J and Meng, Q and Li, C}, title = {Synthesis of Cationic Biphen[4, 5]arenes as Biofilm Disruptors.}, journal = {Angewandte Chemie (International ed. in English)}, volume = {}, number = {}, pages = {e202301857}, doi = {10.1002/anie.202301857}, pmid = {36929684}, issn = {1521-3773}, abstract = {Since bacteria in biofilms are inherently resistant to antibiotics and biofilm-associated infections pose serious threat to global public health, new therapeutic agents and schemes are urgently needed to meet clinical requirements. Here two quaternary ammonium-functionalized biphen[n]arenes (WBPn, n = 4, 5) were designed and synthesized with excellent anti-biofilm potency. Not only could they inhibit assembly of biofilm, but also eradicate intractable mature biofilm formed by Gram-positive S. aureus and Gram-negative E. coli bacterial strains. Moreover, they could strongly complex a conventional antibiotic, cefazolin sodium (CFZ) with complex stability constants of (7.41 ± 0.29) × 104 M-1 for CFZ/WBP4 and (4.98 ± 0.49) × 103 M-1 for CFZ/WBP5. Combination of CFZ by WBP4 and WBP5 synergistically enhanced biofilm eradication performance in vitro and statistically improved healing efficacy on E. coli-infected mice models, providing novel supramolecular strategy for combating biofilm-associated infections.}, }
@article {pmid36929159, year = {2023}, author = {Kobayashi, A and Nakamura, M and Tsujii, M and Makino, K and Nagayama, T and Nakamura, K and Nanatani, K and Kota, K and Furuuchi, Y and Kayamori, S and Furuta, T and Suzuki, I and Hayakawa, Y and Ellen, T and Ishimaru, Y and Uozumi, N}, title = {Two cyanobacterial response regulators with diguanylate cyclase activity, Rre2 and Rre8, participate in biofilm formation.}, journal = {Molecular microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mmi.15057}, pmid = {36929159}, issn = {1365-2958}, abstract = {Phototrophic bacteria face diurnal variations of environmental conditions such as light and osmolarity, that affect their carbon metabolism and ability to generate organic compounds. The model cyanobacterium, Synechocystis sp. PCC 6803 forms a biofilm when it encounters extreme conditions like high salt stress, but the molecular mechanisms involved in perception of environmental changes that lead to biofilm formation are unknown. Here, we studied two two-component regulatory systems (TCSs) that contain diguanylate cyclases (DGCs), which produce the second messenger c-di-GMP, as potential components of the biofilm-inducing signaling pathway in Synechocystis. Analysis of single mutants provided evidence for involvement of Rre2 and Rre8 in biofilm formation. A bacterial two-hybrid assay showed that the response regulators, Rre2 and Rre8 each formed a TCS with a specific histidine kinase, Hik12 and Hik14, respectively. The in vitro assay showed that Rre2 had DGC activity regardless of its de/phosphorylation status, whereas Rre8 required phosphorylation for DGC activity. Hik14-Rre8 likely functioned as an inducible sensing system in response to environmental change. Biofilm assays with Synechocystis mutants suggested that pairs of hik12-rre2 and hik14-rre8 responded to high salinity-induced biofilm formation. Inactivation of hik12-rre2 and hik14-rre8 did not affect the performance of the light reactions of photosynthesis. These data suggest that Hik12-Rre2 and Hik14-Rre8 participate in biofilm formation in Synechocystis by regulating c-di-GMP production via the DGC activity of Rre2 and Rre8.}, }
@article {pmid36928367, year = {2023}, author = {El-Naggar, NE and Dalal, SR and Zweil, AM and Eltarahony, M}, title = {Artificial intelligence-based optimization for chitosan nanoparticles biosynthesis, characterization and in‑vitro assessment of its anti-biofilm potentiality.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {4401}, pmid = {36928367}, issn = {2045-2322}, abstract = {Chitosan nanoparticles (CNPs) are promising biopolymeric nanoparticles with excellent physicochemical, antimicrobial, and biological properties. CNPs have a wide range of applications due to their unique characteristics, including plant growth promotion and protection, drug delivery, antimicrobials, and encapsulation. The current study describes an alternative, biologically-based strategy for CNPs biosynthesis using Olea europaea leaves extract. Face centered central composite design (FCCCD), with 50 experiments was used for optimization of CNPs biosynthesis. The artificial neural network (ANN) was employed for analyzing, validating, and predicting CNPs biosynthesis using Olea europaea leaves extract. Using the desirability function, the optimum conditions for maximum CNPs biosynthesis were determined theoretically and verified experimentally. The highest experimental yield of CNPs (21.15 mg CNPs/mL) was obtained using chitosan solution of 1%, leaves extract solution of 100%, initial pH 4.47, and incubation time of 60 min at 53.83°C. The SEM and TEM images revealed that CNPs had a spherical form and varied in size between 6.91 and 11.14 nm. X-ray diffraction demonstrates the crystalline nature of CNPs. The surface of the CNPs is positively charged, having a Zeta potential of 33.1 mV. FTIR analysis revealed various functional groups including C-H, C-O, CONH2, NH2, C-OH and C-O-C. The thermogravimetric investigation indicated that CNPs are thermally stable. The CNPs were able to suppress biofilm formation by P. aeruginosa, S. aureus and C. albicans at concentrations ranging from 10 to 1500 µg/mL in a dose-dependent manner. Inhibition of biofilm formation was associated with suppression of metabolic activity, protein/exopolysaccharide moieties, and hydrophobicity of biofilm encased cells (r ˃ 0.9, P = 0.00). Due to their small size, in the range of 6.91 to 11.14 nm, CNPs produced using Olea europaea leaves extract are promising for applications in the medical and pharmaceutical industries, in addition to their potential application in controlling multidrug-resistant microorganisms, especially those associated with post COVID-19 pneumonia in immunosuppressed patients.}, }
@article {pmid36926839, year = {2023}, author = {Bird, LJ and Leary, DH and Hervey, J and Compton, J and Phillips, D and Tender, LM and Voigt, CA and Glaven, SM}, title = {Marine Biofilm Engineered to Produce Current in Response to Small Molecules.}, journal = {ACS synthetic biology}, volume = {}, number = {}, pages = {}, doi = {10.1021/acssynbio.2c00417}, pmid = {36926839}, issn = {2161-5063}, abstract = {Engineered electroactive bacteria have potential applications ranging from sensing to biosynthesis. In order to advance the use of engineered electroactive bacteria, it is important to demonstrate functional expression of electron transfer modules in chassis adapted to operationally relevant conditions, such as non-freshwater environments. Here, we use the Shewanella oneidensis electron transfer pathway to induce current production in a marine bacterium, Marinobacter atlanticus, during biofilm growth in artificial seawater. Genetically encoded sensors optimized for use in Escherichia coli were used to control protein expression in planktonic and biofilm attached cells. Significant current production required the addition of menaquinone, which M. atlanticus does not produce, for electron transfer from the inner membrane to the expressed electron transfer pathway. Current through the S. oneidensis pathway in M. atlanticus was observed when inducing molecules were present during biofilm formation. Electron transfer was also reversible, indicating that electron transfer into M. atlanticus could be controlled. These results show that an operationally relevant marine bacterium can be genetically engineered for environmental sensing and response using an electrical signal.}, }
@article {pmid36926823, year = {2023}, author = {Estes Bright, LM and Garren, MRS and Douglass, M and Handa, H}, title = {Synthesis and Characterization of Nitric Oxide-Releasing Ampicillin as a Potential Strategy for Combatting Bacterial Biofilm Formation.}, journal = {ACS applied materials &amp; interfaces}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsami.3c00140}, pmid = {36926823}, issn = {1944-8252}, abstract = {Biofilm formation on biomaterial interfaces and the development of antibiotic-resistant bacteria have decreased the effectiveness of traditional antibiotic treatment of infections. In this project, ampicillin, a commonly used antibiotic, was conjugated with S-nitroso-N-acetylpenicillamine (SNAP), an S-nitrosothiol compound (RSNO) used for controlled nitric oxide (NO) release. This novel multifunctional molecule is the first of its kind to provide combined antibiotic and NO treatment of infectious pathogens. Characterization of the molecule included NMR, FTIR, and mass spectrometry. NO release behavior was also measured and compared to pure, unmodified SNAP. When evaluating the antimicrobial efficacy, the synthesized SNAPicillin molecule showed the lowest MIC value against Gram-negative Pseudomonas aeruginosa and Gram-positive methicillin-resistant Staphylococcus aureus compared to ampicillin and SNAP alone. SNAPicillin also displayed enhanced biofilm dispersal and killing of both bacterial strains when treating a 48 h biofilm preformed on a polymer surface. The antibacterial results combined with the biocompatibility of the molecule show great promise for infection prevention and treatment of polymeric interfaces to reduce medical device-related infections.}, }
@article {pmid36926513, year = {2023}, author = {Varma, A and Warghane, A and Dhiman, NK and Paserkar, N and Upadhye, V and Modi, A and Saini, R}, title = {The role of nanocomposites against biofilm infections in humans.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1104615}, pmid = {36926513}, issn = {2235-2988}, abstract = {The use of nanomaterials in several fields of science has undergone a revolution in the last few decades. It has been reported by the National Institutes of Health (NIH) that 65% and 80% of infections are accountable for at least 65% of human bacterial infections. One of their important applications in healthcare is the use of nanoparticles (NPs) to eradicate free-floating bacteria and those that form biofilms. A nanocomposite (NC) is a multiphase stable fabric with one or three dimensions that are much smaller than 100 nm, or systems with nanoscale repeat distances between the unique phases that make up the material. Using NC materials to get rid of germs is a more sophisticated and effective technique to destroy bacterial biofilms. These biofilms are refractory to standard antibiotics, mainly to chronic infections and non-healing wounds. Materials like graphene and chitosan can be utilized to make several forms of NCs, in addition to different metal oxides. The ability of NCs to address the issue of bacterial resistance is its main advantage over antibiotics. This review highlights the synthesis, characterization, and mechanism through which NCs disrupt Gram-positive and Gram-negative bacterial biofilms, and their relative benefits and drawbacks. There is an urgent need to develop materials like NCs with a larger spectrum of action due to the rising prevalence of human bacterial diseases that are multidrug-resistant and form biofilms.}, }
@article {pmid36924752, year = {2023}, author = {Sterniša, M and Gradišar Centa, U and Drnovšek, A and Remškar, M and Smole Možina, S}, title = {Pseudomonas fragi biofilm on stainless steel (at low temperatures) affects the survival of Campylobacter jejuni and Listeria monocytogenes and their control by a polymer molybdenum oxide nanocomposite coating.}, journal = {International journal of food microbiology}, volume = {394}, number = {}, pages = {110159}, doi = {10.1016/j.ijfoodmicro.2023.110159}, pmid = {36924752}, issn = {1879-3460}, abstract = {Pseudomonas spp. are widely distributed bacteria on surfaces in the food production and processing environment, where they form extracellular polymeric substance rich biofilms that interact with other bacteria. In this study, the influence of biofilm of Pseudomonas fragi ATCC 4973 on Listeria monocytogenes ATCC 19115 and Campylobacter jejuni NCTC 11168 was investigated at 5 °C and 15 °C on stainless steel in broth and food homogenates (fish or chicken meat). Stainless steel was then coated with PVDF-HFP/PVP/MoO3 nanocomposite and examined for surface changes (scanning electron microscope, static contact angle, Vickers hardness and elastic modulus). The effect of the prepared nanocomposite coating on P. fragi and on L. monocytogenes and C. jejuni was evaluated in mono- and co-culture. P. fragi produced more biofilm at 15 °C than at 5 °C, especially when food homogenates were used as growth media. Co-cultivation with pathogens did not affect biofilm production by P. fragi, but significant changes were observed in L. monocytogenes and C. jejuni, resulting in a decrease and increase, respectively, in the determined number of culturable biofilm cells. The first change was probably due to competition for the surface, and the second to the oxygen gradient. Stainless steel was then coated with a PVDF-HFP/PVP/MoO3 nanocomposite, which was characterised by lower roughness and higher wettability, but lower hardness compared to uncoated stainless steel. The prepared nanocoating showed bactericidal activity when tested in phosphate buffered saline. When used in food homogenates, a reduction of over 95 % in bacterial counts was observed. An abundant biofilm of P. fragi proved protective to L. monocytogenes and C. jejuni against the functionalised nanocomposite surface when tested in food homogenates. The control of spoilage Pseudomonas spp., which are common in the food production and processing environment, is important for reducing the contamination of food with spoilage bacteria and with pathogens such as L. monocytogenes and C. jejuni, which may be present in the same environment. The PVDF-HFP/PVP/MoO3 nanocomposite showed good potential for use as a coating for food contact surfaces, but possible migration of nanoparticles from the nanocomposite coating to food should be evaluated before its commercial use.}, }
@article {pmid36922940, year = {2023}, author = {Diaz, A and Dixit, AR and Khodadad, CL and Hummerick, ME and Justiano-Velez, YA and Li, W and O'Rourke, A}, title = {Biofilm formation is correlated with low nutrient and simulated microgravity conditions in a Burkholderia isolate from the ISS water processor assembly.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100110}, pmid = {36922940}, issn = {2590-2075}, abstract = {The International Space Station (ISS) Water Processor Assembly (WPA) experiences intermittent dormancy in the WPA wastewater tank during water recycling events which promotes biofilm formation within the system. In this work we aimed to gain a deeper understanding of the impact of nutrient limitation on bacterial growth and biofilm formation under microgravity in support of biofilm mitigation efforts in exploration water recovery systems. A representative species of bacteria that is commonly cultured from the ISS WPA was cultured in an WPA influent water ersatz formulation tailored for microbiological studies. An isolate of Burkholderia contaminans was cultured under a simulated microgravity (SμG) treatment in a vertically rotating high-aspect rotating vessel (HARV) to create the low shear modeled microgravity (LSMMG) environment on a rotating wall vessel (RWV), with a rotating control (R) in the horizontal plane at the predetermined optimal rotation per minute (rpm) speed of 20. Over the course of the growth curve, the bacterial culture in ersatz media was harvested for bacterial counts, and transcriptomic and nutrient content analyses. The cultures under SμG treatment showed a transcriptomic signature indicative of nutrient stress and biofilm formation as compared to the R control treatment. Further analysis of the WPA ersatz over the course of the growth curve suggests that the essential nutrients of the media were consumed faster in the early stages of growth for the SμG treatment and thus approached a nutrient limited growth condition earlier than in the R control culture. The observed limited nutrient response may serve as one element to explain a moderate enhancement of adherent biofilm formation in the SμG treatment after 24 h. While nutrients levels can be modulated, one implication of this investigation is that biofilm mitigation in the ISS environment could benefit from methods such as mixing or the maintenance of minimum flow within a dormant water system in order to force convection and offset the response of microbes to the secondary effects of microgravity.}, }
@article {pmid36922440, year = {2023}, author = {Ji, C and Wang, H and Cui, H and Zhang, C and Li, R and Liu, T}, title = {Characterization and evaluation of substratum material selection for microalgal biofilm cultivation.}, journal = {Applied microbiology and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {36922440}, issn = {1432-0614}, abstract = {Biofilm cultivation is considered a promising method to achieve higher microalgae biomass productivity with less water consumption and easier harvest compared to conventional suspended cultivation. However, studies focusing on the selection of substratum material and optimization of the growth of certain microalgae species on specific substratum are limited. This study investigated the selection of membranous and fabric fiber substrata for the attachment of unicellular microalgae Scenedesmus dimorphus and filamentous microalgae Tribonema minus in biofilm cultivation. The results indicated that both algal species preferred hydrophilic membranous substrata and nitrate cellulose/cellulose acetate membrane (CN-CA) was selected as a suitable candidate on which the obtained biomass yields were up to 10.24 and 7.81 g m[-2] day[-1] for S. dimorphus and T. minus, respectively. Furthermore, high-thread cotton fiber (HCF) and low-thread polyester fiber (LPEF) were verified as the potential fabric fiber substrata for S. dimorphus (5.42 g m[-2] day[-1]) and T. minus (5.49 g m[-2] day[-1]) attachment, respectively. The regrowth of microalgae biofilm cultivation strategy was applied to optimize the algae growth on the fabric fiber substrata, with higher biomass density and shear resistibility achieved for both algal species. The present data highlight the importance to establish the standards for selection the suitable substratum materials in ensuring the high efficiency and sustainability of the attached microalgal biomass production. KEY POINTS: • CN-CA was suitable membranous substratum candidate for algal biofilm cultivation. • HCF and LPEF were potential fabric fiber substrata for S. dimorphus and T. minus. • Regrowth biofilm cultivation was effective in improving algal biomass and attachment.}, }
@article {pmid36921788, year = {2023}, author = {Yadav, S and Tripathi, S and Purchase, D and Chandra, R}, title = {Development of a biofilm-forming bacterial consortium and quorum sensing molecules for the degradation of lignin-containing organic pollutants.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115618}, doi = {10.1016/j.envres.2023.115618}, pmid = {36921788}, issn = {1096-0953}, abstract = {Due to presence of lignin along with other pollutants makes effluent more complex which is discharged from Pulp and paper mills. The present study investigates the use of biofilm-forming bacteria isolated from pulp paper mill effluent contaminated sites (PPMECSs) for lignin degradation. Isolated biofilm-forming and lignin-degrading bacteria were identified as Bacillus subtilis, Enterobacter cancerogenus, and Bacillus licheniformis by 16S rRNA gene sequencing. Thin liquid chromatography (TLC) analysis showed that the consortium of bacteria produced acyl-homoserine lactone (AHL) as quorum sensing molecules and extracellular polymeric substances (EPS) that protect the bacterial consortium under unfavorable conditions. The potential consortium was able to reduce lignin (900 ppm) by 73% after 8 days of incubation in a minimal salt medium containing kraft lignin and glucose at pH 7.0 and 37 °C as compared to individual strains. The degradation by-products were identified as amides, alcohols, and acids. The major organic pollutants in the effluent were reduced after treatment of the constructed consortium, thus confirming active biotransformation and biodegradation of the lignin. Microscopic examination also indicated the presence of lignin induced biofilm formation. Hence, the constructed biofilm-forming bacterial consortia based on quorum sensing offered a sustainable and effective solution to treat lignin-containing complex pollutants.}, }
@article {pmid36921636, year = {2023}, author = {Yang, L and Pang, S and Zhou, J and Li, X and Yao, M and Xia, S}, title = {Biological Reduction and Hydrodechlorination of Chlorinated Nitroaromatic Antibiotic Chloramphenicol under H2-Transfer Membrane Biofilm Reactor.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128881}, doi = {10.1016/j.biortech.2023.128881}, pmid = {36921636}, issn = {1873-2976}, abstract = {Chlorinated nitroaromatic antibiotic chloramphenicol (CAP) is a persistent pollutant that is widely present in environments. A H2 transfer membrane biofilm reactor (H2-MBfR) and short-term batch tests were setup to investigate the co-removal of CAP and NO- 3. Results showed that the presence of CAP (< 10 mg L[-1]) has no effect on the denitrification process while 100% removal efficiency of CAP can be obtained when nitrate was absent. Nitroaromatic reduction and completely dechlorination were successfully realized when CAP was removed. The CAP transformation product p-aminobenzoic acid (PABA) was detected and batch tests revealed that the hydroxy carboxylation was far faster than nitroaromatic reduction when p-nitrobenzyl alcohol (PNBOH) was conversed to p-aminobenzoic acid (PABA). The path way of CAP degradation was proposed based on the intermediate's analysis. Microbial community analysis indicated that Pleomorphomonadaceae accounts for the dechlorination of CAP.}, }
@article {pmid36921483, year = {2023}, author = {Zeng, X and Mo, Z and Zheng, J and Wei, C and Dai, Y and Yan, Y and Qiu, S}, title = {Effects of biofilm and co-culture with Bacillus velezensis on the synthesis of esters in the strong flavor Baijiu.}, journal = {International journal of food microbiology}, volume = {394}, number = {}, pages = {110166}, doi = {10.1016/j.ijfoodmicro.2023.110166}, pmid = {36921483}, issn = {1879-3460}, abstract = {Biofilm plays an important role in resisting the adverse environment, improving the taste and texture, and promoting the synthesis of flavor substances. However, to date, the findings on the effect of biofilm and dominating bacteria Bacillus on the ester synthesis in the Baijiu field have been largely lacked. Therefore, the objectives of the present study were to primarily isolate biofilm-producing microbes in the fermented grains, evaluate the stress tolerance capacity, and unveil the effect of biofilm and co-culture with Bacillus on the ester synthesis in the strong flavor Baijiu. Results indicated that after isolation and evaluation of stress-tolerance capacity, bacterial strain BG-5 and yeast strains YM-21 and YL-10 were demonstrated as mediate or strong biofilm-producing microbes and were identified as Bacillus velezensis, Saccharomycopsis fibuligera, and Zygosaccharomyces bailii, respectively. Solid phase microextraction/gas chromatography-mass spectrometer indicated that biofilm could enhance the diversity of esters while reduce the contents of ester. The scanning electron microscopy showed an inhibitory effect of B. velezensis on the growth of S. fibuligera, further restraining the production of esters. Taken together, both biofilm and B. velezensis influence the ester synthesis process. The present study is the first to reveal the biofilm-producing microorganisms in fermented grains and to preliminarily investigate the effect of biofilm on the ester synthesis in the Baijiu field.}, }
@article {pmid36920192, year = {2023}, author = {Al-Shamiri, MM and Wang, J and Zhang, S and Li, P and Odhiambo, WO and Chen, Y and Han, B and Yang, E and Xun, M and Han, L and Han, S}, title = {Probiotic Lactobacillus Species and Their Biosurfactants Eliminate Acinetobacter baumannii Biofilm in Various Manners.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0461422}, doi = {10.1128/spectrum.04614-22}, pmid = {36920192}, issn = {2165-0497}, abstract = {Acinetobacter baumannii is a critical biofilm-forming pathogen that has presented great challenges in the clinic due to multidrug resistance. Thus, new methods of intervention are needed to control biofilm-associated infections. In this study, among three tested Lactobacillus species, Lactobacillus rhamnosus showed significant antimaturation and antiadherence effects against A. baumannii biofilm. Lactic acid (LA) and acetic acid (AA) were the most effective antibiofilm biosurfactants (BSs) produced by L. rhamnosus. This antibiofilm phenomenon produced by LA and AA was due to the strong bactericidal effect, which worked from very early time points, as determined by colony enumeration and confocal laser scanning microscope. The cell destruction of A. baumannii appeared in both the cell envelope and cytoplasm. A discontinuous cell envelope, the leakage of cell contents, and the increased extracellular activity of ATPase demonstrated the disruption of the cell membrane by LA and AA. These effects also demonstrated the occurrence of protein lysis. In addition, bacterial DNA interacted with and was damaged by LA and AA, resulting in significantly reduced expression of biofilm and DNA repair genes. The results highlight the possibility and importance of using probiotics in clinical prevention. Probiotics can be utilized as novel biocides to block and decrease biofilm formation and microbial contamination in medical equipment and during the treatment of infections. IMPORTANCE A. baumannii biofilm is a significant virulence factor that causes the biofilm colonization of invasive illnesses. Rising bacterial resistance to synthetic antimicrobials has prompted researchers to look at natural alternatives, such as probiotics and their derivatives. In this study, L. rhamnosus and its BSs (LA and AA) demonstrated remarkable antibiofilm and antimicrobial characteristics, with a significant inhibitory effect on A. baumannii. These effects were achieved by several mechanisms, including the disruption of the cell envelope membrane, protein lysis, reduced expression of biofilm-related genes, and destruction of bacterial DNA. The results provide support for the possibility of using probiotics and their derivatives in the clinical prevention and therapy of A. baumannii infections.}, }
@article {pmid36916551, year = {2023}, author = {Nguyen Trang, P and Thi Anh Ngoc, T and Masuda, Y and Hohjoh, KI and Miyamoto, T}, title = {Biofilm Formation From Listeria monocytogenes Isolated From Pangasius Fish-processing Plants.}, journal = {Journal of food protection}, volume = {86}, number = {3}, pages = {100044}, doi = {10.1016/j.jfp.2023.100044}, pmid = {36916551}, issn = {1944-9097}, mesh = {Animals ; *Listeria monocytogenes ; Muramidase/pharmacology ; Chlorine/pharmacology ; Polylysine/pharmacology ; Stainless Steel ; Biofilms ; *Catfishes ; Water/pharmacology ; Colony Count, Microbial ; }, abstract = {Biofilm formation of Listeria monocytogenes in food processing environments cause potential source of cross-contamination to foodstuffs; hence, the control of biofilm is currently addressed to find effective solutions for preventing biofilm formation or eliminating the established one. Forty-five strains of Listeria monocytogenes isolated from Pangasius fish-processing plants were studied for their capability to form a biofilm on 96-well microtiter plate by using the conventional crystal violet staining. Additionally, the inhibitory effect of biofilm formation by food additives including monascus pigment and ε-polylysine was examined. The average OD value showing biofilm mass of all 45 strains L. monocytogenes increased with an increasing temperature and time (p < 0.05). Monascus pigment and ε-polylysine significantly decreased biofilm formation by 80 ± 5.5% and 20 ± 5.9%, respectively, at the tested concentration (p < 0.05) Further, the effects of lysozyme (0.1 mg/mL) alone or in combination with slightly acidic hypochlorous water (SAHW) with 40 mg/L available chlorine or sodium hypochlorite (NaOCl) with 100 mg/L available chlorine against 7-d established biofilm of L. monocytogenes were investigated. The results indicated that slightly acidic hypochlorous water alone exhibited significant antibacterial activity (p < 0.05), decreasing the viable count by 5.2 ± 0.5 log CFU/mL. It seems that sequential treatment of lysozyme and SAHW showed an additional efficacy against biofilm of L. monocytogenes on polystyrene plate surface, reducing 70% of biomass of biofilm and 7.6 ± 0.3 log of biofilm viable cells (p < 0.05). Additionally, SAHW exhibited greater bactericidal activity against viable biofilm cells than NaOCl did. This result reveals that SAHW is a promising disinfectant agent against L. monocytogenes and the potential alternative to NaOCl in practice.}, }
@article {pmid36914689, year = {2023}, author = {Bano, N and Iqbal, D and Al Othaim, A and Kamal, M and Albadrani, HM and Algehainy, NA and Alyenbaawi, H and Alghofaili, F and Amir, M and Roohi, }, title = {Antibacterial efficacy of synthesized silver nanoparticles of Microbacterium proteolyticum LA2(R) and Streptomyces rochei LA2(O) against biofilm forming meningitis causing microbes.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {4150}, pmid = {36914689}, issn = {2045-2322}, mesh = {Humans ; Silver/pharmacology/chemistry ; *Metal Nanoparticles/chemistry ; Anti-Bacterial Agents/chemistry ; *Streptomyces ; Biofilms ; *Actinomycetales ; *Actinobacteria ; *Meningitis ; Microbial Sensitivity Tests ; }, abstract = {Actinobacteria obtained from the least explored Indian regions were studied for their ability to suppress meningitis-causing bacteria in nanoparticle form. Drug-resistant bacteria and long-term treatment with different medications make meningitis control complicated. Thus, new meningitis drugs are required to combat MDR bacteria. In this study, secondary metabolites isolated from actinomycetes strains, Microbacterium proteolyticum LA2(R) and Streptomyces rochei LA2(O), were employed to synthesize silver nanoparticles (AgNPs) at 37 °C for seven days incubation. UV-Vis spectroscopy, TEM, FTIR, and HPLC studies were used for the confirmation of the synthesis of AgNPs. Furthermore, these NPs demonstrated antibacterial and antibiofilm activities against meningitis-causing bacteria. The average size of LA2(R) and LA2(O) isolated secondary metabolites mediated AgNPs was observed to be 27 ± 1and 29 ± 2 nm by TEM analysis. FTIR study of RAgNPs and OAgNPs revealed that presence of peaks with positions of 1637.17 cm[1] and 1636.10 cm[1] for C=O amide group appearances in the amide I linkage. These NPs were effective against bacterial pathogens such as S. pneumoniae, H. influenzae, and N. meningitidis and confirmed by their MICs, i.e., 109.4, 120.60, and 138.80 μg/ml of RAgNPs and 105.80, 114.40 and 129.06 μg/ml of OAgNPs, respectively. Additionally, the production of biofilms is impeded by these nanoparticles on S. pneumoniae, H. influenzae, and N. meningitidis by 73.14%, 71.89% and 64.81%, respectively. These findings confirm the potential role of synthesized AgNPs against biofilm forming meningitis causing Multidrug resistance (MDR) microbes.}, }
@article {pmid36914349, year = {2023}, author = {Wang, D and Fletcher, GC and Gagic, D and On, SLW and Palmer, JS and Flint, SH}, title = {Comparative genome identification of accessory genes associated with strong biofilm formation in Vibrio parahaemolyticus.}, journal = {Food research international (Ottawa, Ont.)}, volume = {166}, number = {}, pages = {112605}, doi = {10.1016/j.foodres.2023.112605}, pmid = {36914349}, issn = {1873-7145}, mesh = {*Vibrio parahaemolyticus/genetics ; Biofilms ; Genomics ; Operon ; Cellulose ; }, abstract = {Vibrio parahaemolyticus biofilms on the seafood processing plant surfaces are a potential source of seafood contamination and subsequent food poisoning. Strains differ in their ability to form biofilm, but little is known about the genetic characteristics responsible for biofilm development. In this study, pangenome and comparative genome analysis of V. parahaemolyticus strains reveals genetic attributes and gene repertoire that contribute to robust biofilm formation. The study identified 136 accessory genes that were exclusively present in strong biofilm forming strains and these were functionally assigned to the Gene Ontology (GO) pathways of cellulose biosynthesis, rhamnose metabolic and catabolic processes, UDP-glucose processes and O antigen biosynthesis (p < 0.05). Strategies of CRISPR-Cas defence and MSHA pilus-led attachment were implicated via Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. Higher levels of horizontal gene transfer (HGT) were inferred to confer more putatively novel properties on biofilm-forming V. parahaemolyticus. Furthermore, cellulose biosynthesis, a neglected potential virulence factor, was identified as being acquired from within the order Vibrionales. The cellulose synthase operons in V. parahaemolyticus were examined for their prevalence (22/138, 15.94 %) and were found to consist of the genes bcsG, bcsE, bcsQ, bcsA, bcsB, bcsZ, bcsC. This study provides insights into robust biofilm formation of V. parahaemolyticus at the genomic level and facilitates: identification of key attributes for robust biofilm formation, elucidation of biofilm formation mechanisms and development of potential targets for novel control strategies of persistent V. parahaemolyticus.}, }
@article {pmid36914121, year = {2023}, author = {Rožman, M and Lekunberri, I and Grgić, I and Borrego, CM and Petrović, M}, title = {Effects of combining flow intermittency and exposure to emerging contaminants on the composition and metabolic response of streambed biofilm bacterial communities.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162818}, doi = {10.1016/j.scitotenv.2023.162818}, pmid = {36914121}, issn = {1879-1026}, abstract = {Freshwater ecosystems are characterised by the co-occurrence of stressors that simultaneously affect the biota. Among these, flow intermittency and chemical pollution severely impair the diversity and functioning of streambed bacterial communities. Using an artificial streams mesocosm facility, this study examined how desiccation and pollution caused by emerging contaminants affect the composition of stream biofilm bacterial communities, their metabolic profiles, and interactions with their environment. Through integrative analysis of the composition of biofilm communities, characterization of their metabolome and composition of the dissolved organic matter, we found strong genotype-to-phenotype interconnections. The strongest correlation was found between the composition and metabolism of the bacterial community, both of which were influenced by incubation time and desiccation. Unexpectedly, no effect of the emerging contaminants was observed, which was due to the low concentration of the emerging contaminants and the dominant impact of desiccation. However, biofilm bacterial communities modified the chemical composition of their environment under the effect of pollution. Considering the tentatively identified classes of metabolites, we hypothesised that the biofilm response to desiccation was mainly intracellular while the response to chemical pollution was extracellular. The present study demonstrates that metabolite and dissolved organic matter profiling may be effectively integrated with compositional analysis of stream biofilm communities to yield a more complete picture of changes in response to stressors.}, }
@article {pmid36913883, year = {2023}, author = {Bajaj, A and Abutoama, M and Isaacs, S and Abuleil, MJ and Yaniv, K and Kushmaro, A and Modic, M and Cvelbar, U and Abdulhalim, I}, title = {Biofilm growth monitoring using guided wave ultralong-range Surface Plasmon Resonance: A proof of concept.}, journal = {Biosensors &amp; bioelectronics}, volume = {228}, number = {}, pages = {115204}, doi = {10.1016/j.bios.2023.115204}, pmid = {36913883}, issn = {1873-4235}, abstract = {Unwelcomed biofilms are problematic in food industries, surgical devices, marine applications, and wastewater treatment plants, essentially everywhere where there is moisture. Very recently, label-free advanced sensors such as localized and extended surface plasmon resonance (SPR) have been explored as tools for monitoring biofilm formation. However, conventional noble metal SPR substrates suffer from low penetration depth (100-300 nm) into the dielectric medium above the surface, preventing the reliable detection of large entities of single or multi-layered cell assemblies like biofilms which can grow up to a few micrometers or more. In this study, we propose using a plasmonic insulator-metal-insulator (IMI) structure (SiO2-Ag-SiO2) with a higher penetration depth based on a diverging beam single wavelength format of Kretschmann configuration in a portable SPR device. An SPR line detection algorithm for locating the reflectance minimum of the device helps to view changes in refractive index and accumulation of the biofilm in real-time down to 10[-7] RIU precision. The optimized IMI structure exhibits strong penetration dependence on wavelength and incidence angle. Within the plasmonic resonance, different angles penetrate different depths, showing a maximum near the critical angle. At the wavelength of 635 nm, a high penetration depth of more than 4 μm was obtained. Compared to a thin gold film substrate, for which the penetration depth is only ∼200 nm, the IMI substrate provides more reliable results. The average thickness of the biofilm after 24 h of growth was found to be between 6 and 7 μm with ∼63% live cell volume, as estimated from confocal microscopic images using an image processing tool. To explain this saturation thickness, a graded index biofilm structure is proposed in which the refractive index decreases with the distance from the interface. Furthermore, when plasma-assisted degeneration of biofilms was studied in a semi-real-time format, there was almost no effect on the IMI substrate compared to the gold substrate. The growth rate over the SiO2 surface was higher than on gold, possibly due to differences between surface charge effects. On the gold, the excited plasmon generates an oscillating cloud of electrons, while for the SiO2 case, this does not happen. This methodology can be utilized to detect and characterize biofilms with better signal reliability with respect to concentration and size dependence.}, }
@article {pmid36913810, year = {2023}, author = {Yan, X and Sun, J and Wang, Y and Zhang, Z and Zhang, C and Li, W and Xu, J and Dai, X and Ni, BJ}, title = {Low-rate ferrate dosing damages the microbial biofilm structure through humic substances destruction and facilitates the sewer biofilm control.}, journal = {Water research}, volume = {235}, number = {}, pages = {119834}, doi = {10.1016/j.watres.2023.119834}, pmid = {36913810}, issn = {1879-2448}, abstract = {The microbial activities in sewer biofilms are recognized as a major reason for sewer pipe corrosion, malodor, and greenhouse gas emissions. However, conventional methods to control sewer biofilm activities were based on the inhibitory or biocidal effect of chemicals and often required long exposure time or high dosing rates due to the protection of sewer biofilm structure. Therefore, this study attempt to use ferrate (Fe(VI)), a green and high-valent iron, at low dosing rates to damage the sewer biofilm structure so as to enhance sewer biofilm control efficiency. The results showed the biofilm structure started to crush when the Fe(VI) dosage was 15 mg Fe(VI)/L and the damage enhanced with the increasing dosage. The determination of extracellular polymeric substances (EPS) showed that Fe(VI) treatment at 15-45 mgFe/L mainly decreased the content of humic substances (HS) in biofilm EPS. This is because the functional groups, such as C-O, -OH, and C=O, which held the large molecular structure of HS, were the primary target of Fe(VI) treatment as suggested by 2D-Fourier Transform Infrared spectra. As a result, the coiled chain of EPS maintained by HS was turned to extended and dispersed and consequently led to a loosed biofilm structure. The XDLVO analysis suggested that both the microbial interaction energy barrier and secondary energy minimum were increased after Fe(VI) treatment, suggesting that the treated biofilm was less likely to aggregate and easier to be removed by the shear stress caused by high wastewater flow. Moreover, combined Fe(VI) and free nitrous acid (FNA) dosing experiments showed for achieving 90% inactivation, the FNA dosing rate could be reduced by 90% with the exposure time decreasing by 75% at a low Fe(VI) dosing rate and the total cost was substantially decreased. These results suggested that applying low-rate Fe(VI) dosing for sewer biofilm structure destruction is expected to be an economical way to facilitate sewer biofilm control.}, }
@article {pmid36913408, year = {2023}, author = {Bing, J and Guan, Z and Zheng, T and Zhang, Z and Fan, S and Ennis, CL and Nobile, CJ and Huang, G}, title = {Clinical isolates of Candida auris with enhanced adherence and biofilm formation due to genomic amplification of ALS4.}, journal = {PLoS pathogens}, volume = {19}, number = {3}, pages = {e1011239}, doi = {10.1371/journal.ppat.1011239}, pmid = {36913408}, issn = {1553-7374}, abstract = {Candida auris is an emerging multidrug-resistant fungal pathogen and a new global threat to human health. A unique morphological feature of this fungus is its multicellular aggregating phenotype, which has been thought to be associated with defects in cell division. In this study, we report a new aggregating form of two clinical C. auris isolates with increased biofilm forming capacity due to enhanced adherence of adjacent cells and surfaces. Unlike the previously reported aggregating morphology, this new aggregating multicellular form of C. auris can become unicellular after treatment with proteinase K or trypsin. Genomic analysis demonstrated that amplification of the subtelomeric adhesin gene ALS4 is the reason behind the strain's enhanced adherence and biofilm forming capacities. Many clinical isolates of C. auris have variable copy numbers of ALS4, suggesting that this subtelomeric region exhibits instability. Global transcriptional profiling and quantitative real-time PCR assays indicated that genomic amplification of ALS4 results in a dramatic increase in overall levels of transcription. Compared to the previously characterized nonaggregative/yeast-form and aggregative-form strains of C. auris, this new Als4-mediated aggregative-form strain of C. auris displays several unique characteristics in terms of its biofilm formation, surface colonization, and virulence.}, }
@article {pmid36911973, year = {2023}, author = {Ürer, EK and Aslantaş, &#xd6; and Tek, E and Yılmaz, MA and Ergün, Y}, title = {Antimicrobial susceptibility and biofilm forming ability of staphylococci from subclinical buffalo mastitis.}, journal = {The Journal of dairy research}, volume = {}, number = {}, pages = {1-4}, doi = {10.1017/S0022029923000080}, pmid = {36911973}, issn = {1469-7629}, abstract = {The starting objective of this research communication was to determine the prevalence of subclinical mastitis in buffalo in Turkey. We also seeked to isolate and identify staphylococci, determine their antimicrobial susceptibilities and biofilm-forming abilities as well as investigating the presence of biofilm-related genes and microbial surface components recognizing adhesive matrix molecules. A total of 107 (66.9%) staphylococci (28 S. aureus and 79 coagulase-negative staphylococci, CoNS) were isolated from 160 mastitic milk samples collected from 200 lactating water buffalos. The staphylococci were especially resistant to beta-lactams except for cefoxitin but were less resistant to the other antimicrobials that were tested. Based on the Congo red agar method, 92.9% of the S. aureus and 70.9% of the CoNS isolates were positive for biofilm-forming ability, while all S. aureus and 97.5% of CoNS isolates were positive by a microtiter plate analysis. The presence of icaA and icaD genes was not always correlated with biofilm synthesis, and even in the absence of these genes, the isolates were able to synthesize biofilm.}, }
@article {pmid36911868, year = {2023}, author = {Fukushima, S and Yamamoto, K and Nakano, Y and Hagiya, H and Otsuka, F}, title = {Biofilm-associated candidal thrombophlebitis.}, journal = {IDCases}, volume = {31}, number = {}, pages = {e01733}, pmid = {36911868}, issn = {2214-2509}, }
@article {pmid36911333, year = {2023}, author = {Kim, JY and Moon, EC and Kim, JY and Kim, HJ and Heo, K and Shim, JJ and Lee, JL}, title = {Lactobacillus helveticus HY7801 ameliorates bacterial vaginosis by inhibiting biofilm formation and epithelial cell adhesion of Gardnerella vaginalis.}, journal = {Food science and biotechnology}, volume = {32}, number = {4}, pages = {507-515}, pmid = {36911333}, issn = {2092-6456}, abstract = {UNLABELLED: Bacterial vaginosis (BV) is caused by a microbial imbalance in the vaginal ecosystem, which causes genital discomfort and a variety of potential complications in women. This study validated the potential of Lactobacillus helveticus HY7801 as a probiotic to benefit vaginal health. In vivo, HY7801 reduced the number of Gardnerella vaginalis (GV) and pro-inflammatory cytokines in the vagina of GV-induced BV mice and ameliorated vaginal histological changes. In vitro, HY7801 exhibited positive resistance to simulated gastrointestinal conditions, showed excellent adherence ability to the female genital epithelium, and had high lactic acid and H2O2 production capacity. Furthermore, it was found that HY7801 can alleviate BV because it can suppress the expression of virulence factor genes of GV involved in epithelial cell adhesion and biofilm formation along with antibacterial activity against GV. These results indicate that HY7801 can be used as a promising probiotic strain for the maintenance of a healthy vaginal physiological state.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-022-01208-7.}, }
@article {pmid36910511, year = {2023}, author = {Fleeman, RM and Mikesh, M and Davies, BW}, title = {Investigating Klebsiella pneumoniae biofilm preservation for scanning electron microscopy.}, journal = {Access microbiology}, volume = {5}, number = {2}, pages = {}, pmid = {36910511}, issn = {2516-8290}, abstract = {Klebsiella pneumoniae biofilm formation is associated with chronic and relapsing infections. Scanning electron microscopy (SEM) is a powerful tool for characterizing biofilm structure and studying their formation. Reliable visualization of biofilm structure requires careful sample preservation, otherwise there may be loss of non-covalent interactions that are susceptible to damage during the dehydration and washing preparation steps. However, no standard procedure has been adopted in the literature to fix K. pneumoniae biofilm for scanning electron microscopy studies. This lack of standardization makes it challenging to compare results between studies and determine the degree to which native structures have been preserved. To advance this critical area of study, we investigated different scanning electron microscopy fixation methods for K. pneumoniae biofilm preservation. Our study reveals the impact preparation steps can have on retaining in biofilm architecture observed using scanning electron microscopy. Using fixation methods developed through our studies, we show that although species that overproduce capsular extracellular polysaccharides produced more robust biofilms, K. pneumoniae can form a developed biofilm in the absence of capsular polysaccharides.}, }
@article {pmid36910230, year = {2023}, author = {Mirzaei, R and Esmaeili Gouvarchin Ghaleh, H and Ranjbar, R}, title = {Antibiofilm effect of melittin alone and in combination with conventional antibiotics toward strong biofilm of MDR-MRSA and -Pseudomonas aeruginosa.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1030401}, pmid = {36910230}, issn = {1664-302X}, abstract = {INTRODUCTION: Multidrug-resistant (MDR) pathogens are being recognized as a critical threat to human health if they can form biofilm and, in this sense, biofilm-forming MDR-methicillin resistant Staphylococcus aureus (MRSA) and -Pseudomonas aeruginosa strains are a worse concern. Hence, a growing body of documents has introduced antimicrobial peptides (AMPs) as a substitute candidate for conventional antimicrobial agents against drug-resistant and biofilm-associated infections. We evaluated melittin's antibacterial and antibiofilm activity alone and/or in combination with gentamicin, ciprofloxacin, rifampin, and vancomycin on biofilm-forming MDR-P. aeruginosa and MDR-MRSA strains.<br><br>METHODS: Antibacterial tests [antibiogram, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC)], anti-biofilm tests [minimum biofilm inhibition concentration (MBIC), and minimum biofilm eradication concentration (MBEC)], as well as synergistic antibiofilm activity of melittin and antibiotics, were performed. Besides, the influence of melittin alone on the biofilm encoding genes and the cytotoxicity and hemolytic effects of melittin were examined.<br><br>RESULTS: MIC, MBC, MBIC, and MBEC indices for melittin were in the range of 0.625-5, 1.25-10, 2.5-20, and 10-40 &#x3bc;g/ml, respectively. The findings found that the combination of melittin AMP with antibiotics was synergistic and fractional biofilm inhibitory concentration index (FBICi) for most tested concentrations was <0.5, resulting in a significant reduction in melittin, gentamicin, ciprofloxacin, vancomycin, and rifampin concentrations by 2-256.4, 2-128, 2-16, 4-64 and 4-8 folds, respectively. This phenomenon reduced the toxicity of melittin, whereby its synergist concentration required for biofilm inhibition did not show cytotoxicity and hemolytic activity. Our findings found that melittin decreased the expression of icaA in S. aureus and LasR in P. aeruginosa genes from 0.1 to 4.11 fold for icaA, and 0.11 to 3.7 fold for LasR, respectively.<br><br>CONCLUSION: Overall, the results obtained from our study show that melittin alone is effective against the strong biofilm of MDR pathogens and also offers sound synergistic effects with antibiotics without toxicity. Hence, combining melittin and antibiotics can be a potential candidate for further evaluation of in vivo infections by MDR pathogens.}, }
@article {pmid36909500, year = {2023}, author = {Cassin, EK and Araujo-Hernandez, SA and Baughn, DS and Londono, MC and Rodriguez, DQ and Tseng, BS}, title = {OprF impacts Pseudomonas aeruginosa biofilm matrix eDNA levels in a nutrient-dependent manner.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.03.01.530729}, pmid = {36909500}, abstract = {UNLABELLED: The biofilm matrix is composed of exopolysaccharides, eDNA, membrane vesicles, and proteins. While proteomic analyses have identified numerous matrix proteins, their functions in the biofilm remain understudied compared to the other biofilm components. In the Pseudomonas aeruginosa biofilm, several studies have identified OprF as an abundant matrix protein and, more specifically, as a component of biofilm membrane vesicles. OprF is a major outer membrane porin of P. aeruginosa cells. However, current data describing the effects of OprF in the P. aeruginosa biofilm is limited. Here we identify a nutrient-dependent effect of OprF in static biofilms, whereby Δ oprF cells form significantly less biofilm than wild type when grown in media containing glucose or low sodium chloride concentrations. Interestingly, this biofilm defect occurs during late static biofilm formation and is not dependent on the production of PQS, which is responsible for outer membrane vesicle production. Furthermore, while biofilms lacking OprF contain approximately 60% less total biomass than those of wild type, the number of cells in these two biofilms is equivalent. We demonstrate that P. aeruginosa Δ oprF biofilms with reduced biofilm biomass contain less eDNA than wild-type biofilms. These results suggest that the nutrient-dependent effect of OprF is involved in the maintenance of mature P. aeruginosa biofilms by retaining eDNA in the matrix.<br><br>IMPORTANCE: Many pathogens form biofilms, which are bacterial communities encased in an extracellular matrix that protects them against antibacterial treatments. The roles of several matrix components of the opportunistic pathogen Pseudomonas aeruginosa have been characterized. However, the effects of P. aeruginosa matrix proteins remain understudied and are untapped potential targets for antibiofilm treatments. Here we describe a conditional effect of the abundant matrix protein OprF on late-stage P. aeruginosa biofilms. A &#x394; oprF strain formed significantly less biofilm in low sodium chloride or with glucose. Interestingly, the defective &#x394; oprF biofilms did not exhibit fewer resident cells but contained significantly less extracellular DNA (eDNA) than wild type. These results suggest that OprF is involved in matrix eDNA retention in mature biofilms.}, }
@article {pmid36908866, year = {2023}, author = {Hamad, PA}, title = {Phenotypic and Molecular Detection of Biofilm Formation in Methicillin-Resistant Staphylococcus Aureus Isolated from Different Clinical Sources in Erbil City.}, journal = {Mediterranean journal of hematology and infectious diseases}, volume = {15}, number = {1}, pages = {e2023016}, pmid = {36908866}, issn = {2035-3006}, abstract = {BACKGROUND: Staphylococcus aureus is an important causative pathogen. The production of biofilms is an important factor and makes these bacteria resistant to antimicrobial therapy.<br><br>OBJECTIVES: the current study aimed to assess the prevalence of resistance to antibacterial agents and to evaluate the phenotypic and genotypic characterization of biofilm formation among S. aureus strains.<br><br>METHODS: This study included 50 isolates of Methicillin-resistant S. aureus (MRSA) and Methicillin-Susceptible S. aureus (MSSA). S. aureus was identified by molecular and conventional methods, and antimicrobial resistance was tested with a disc diffusion method. The biofilm formation was performed through the Microtiter plate method. Strains were subjected to PCR to determine the presence of nuc, mecA, icaA, icaB, icaC, and icaD genes.<br><br>RESULTS: Of the 50 S. aureus isolates, 32(64%) and 18(36%) were MRSA and MSSA, respectively. A large number of MRSA and MSSA isolates showed resistance to Penicillin and Azithromycin, and a lower number of MRSA and MSSA isolates showed resistance to Amikacin Gentamicin. None of the isolates was resistant to Vancomycin. The MRSA strains had significantly higher resistance against antibiotics than MSSA strains (P = 0.0154). All isolates (MRSA and MSSA) were able to produce biofilm with levels ranging from strong (31.25 %), (16.6%) to moderate (53.12%), (50%) to weak (15.6%), (33.3%) respectively. The MRSA strains had a significantly higher biofilm formation ability than the MSSA strains (P = 0.0079). The biofilm-encoding genes were detected among isolates with different frequencies. The majority of S. aureus isolates, 42 (84%), were positive for the icaA. The prevalence rates of the icaB, icaC and icaD genes were found to be 37 (74%), 40 (80%) and 41 (82%), respectively.<br><br>CONCLUSIONS: The prevalence of biofilm encoding genes associated with multidrug resistance in S. aureus strains is high. Therefore, identifying epidemiology, molecular characteristics, and biofilm management of S. aureus infection would be helpful.}, }
@article {pmid36907929, year = {2023}, author = {Maurya, A and Kumar, R and Raj, A}, title = {Biofilm-based technology for industrial wastewater treatment: current technology, applications and future perspectives.}, journal = {World journal of microbiology &amp; biotechnology}, volume = {39}, number = {5}, pages = {112}, pmid = {36907929}, issn = {1573-0972}, abstract = {The microbial community in biofilm is safeguarded from the action of toxic chemicals, antimicrobial compounds, and harsh/stressful environmental circumstances. Therefore, biofilm-based technology has nowadays become a successful alternative for treating industrial wastewater as compared to suspended growth-based technologies. In biofilm reactors, microbial cells are attached to static or free-moving materials to form a biofilm which facilitates the process of liquid and solid separation in biofilm-mediated operations. This paper aims to review the state-of-the-art of recent research on bacterial biofilm in industrial wastewater treatment including biofilm fundamentals, possible applications and problems, and factors to regulate biofilm formation. We discussed in detail the treatment efficiencies of fluidized bed biofilm reactor (FBBR), trickling filter reactor (TFR), rotating biological contactor (RBC), membrane biofilm reactor (MBfR), and moving bed biofilm reactor (MBBR) for different types of industrial wastewater treatment. Besides, biofilms have many applications in food and agriculture, biofuel and bioenergy production, power generation, and plastic degradation. Furthermore, key factors for regulating biofilm formation were also emphasized. In conclusion, industrial applications make evident that biofilm-based treatment technology is impactful for pollutant removal. Future research to address and improve the limitations of biofilm-based technology in wastewater treatment is also discussed.}, }
@article {pmid36907420, year = {2023}, author = {Zhuang, LL and Tian, W and Yang, Y and Ge, S and Li, P and Sun, S and Zhang, J and Liang, S}, title = {Quantified trend of photosynthetic rate along the depth of microalgae biofilm.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162801}, doi = {10.1016/j.scitotenv.2023.162801}, pmid = {36907420}, issn = {1879-1026}, abstract = {Compared with suspended microalgae cultivation, attached microalgae cultivation for wastewater treatment has advantages of low biomass recovery costs and high robustness. As a heterogeneous system, the variation of photosynthetic capacity along biofilm depth lacks quantitative conclusions. The distribution curve of oxygen concentration along the depth of attached microalgae biofilm (f(x)) was detected by dissolved oxygen (DO) microelectrode, and a quantified model was built based on mass conservation and Fick's law. It revealed that the net photosynthetic rate at a certain depth (x) in the biofilm showed a linear relationship with the second derivatives of the distribution curve of oxygen concentration (f″(x)). In addition, the declining trend of photosynthetic rate of attached microalgae with depth was relatively slow compared with the suspended system. The net photosynthetic rate of algae biofilm decreased gradually with depth and was only 3.60 %-17.86 % of that of the surface layer at 150-200 μm depth. Moreover, the light saturation points of the attached microalgae got lower along the depth of biofilm. Compared to 400 lx light intensity, the net photosynthetic rate of microalgae biofilm at the depths of 100-150 μm and 150-200 μm increased by 389 % and 956 % under 5000 lx, respectively, showing the high photosynthesis potential with increasing light.}, }
@article {pmid36907360, year = {2023}, author = {Centeleghe, DI and Norville, DP and Hughes, DL and Maillard, PJ}, title = {Klebsiella pneumoniae survives on surfaces as a dry biofilm.}, journal = {American journal of infection control}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.ajic.2023.02.009}, pmid = {36907360}, issn = {1527-3296}, abstract = {BACKGROUND: Dry surface biofilms (DSB) are widespread in healthcare settings presenting a challenge to cleaning and disinfection. Klebsiella pneumoniae has been a focus of attention due to antibiotic resistance and the emergence of hypervirulent strains. Few studies have demonstrated K. pneumoniae survival on surfaces following desiccation.<br><br>METHODS: DSB were formed over 12 days. Bacterial culturability and transfer were investigated following DSB incubation up to four weeks. Bacterial viability in DSB was investigated with live/dead staining using flow cytometry.<br><br>RESULTS: K. pneumoniae formed mature DSB. After two and four weeks of incubation, transfer from DSB was low (<55%) and reduced further (<21%) following wiping. Culturability at two and four weeks varied although viability remained high indicating viable but non culturable state (VBNC).<br><br>DISCUSSION: K. pneumoniae was removed from surfaces by mechanical wiping as shown with DSB of other species. Although culturability was reduced over time, bacteria remained viable up to four weeks incubation, proving the need for robust cleaning regimens.<br><br>CONCLUSIONS: This is the first study confirming K. pneumoniae survival on dry surfaces as a DSB. The presence of VBNC bacteria indicated that K. pneumoniae can for extended periods, raising questions about its persistence on surfaces.}, }
@article {pmid36906314, year = {2023}, author = {Liu, J and Wu, S and Feng, L and Wu, Y and Zhu, J}, title = {Extracellular matrix affects mature biofilm and stress resistance of psychrotrophic spoilage Pseudomonas at cold temperature.}, journal = {Food microbiology}, volume = {112}, number = {}, pages = {104214}, doi = {10.1016/j.fm.2023.104214}, pmid = {36906314}, issn = {1095-9998}, abstract = {Psychrotrophic Pseudomonas as the dominant spoilage bacteria, have biofilm forming ability, increasing persistence and contamination in the chilled food. Biofilm formation of spoilage Pseudomonas at cold temperature was documented, however, role of extracellular matrix in mature biofilm and stress resistance of psychrotrophic Pseudomonas are much less abundant. The aim of this study was to investigate the biofilm forming characteristics of three spoilers P. fluorescens PF07, P. lundensis PL28, and P. psychrophile PP26 at 25 °C, 15 °C and 4 °C, and to explore their stress resistance to chemical and thermal treatments of mature biofilms. The results showed that biofilm biomass of three Pseudomonas at 4 °C was significantly higher than that at 15 °C and 25 °C. The secretion of extracellular polymeric substances (EPS) greatly increased in those Pseudomonas under low temperature, of which extracellular protein constituted about 71.03%-77.44%. Compared to 25 °C, the mature biofilms were observed to more aggregation and thicker spatial structure at 4 °C ranging from 42.7 to 54.6 μm, in contrast to 25.0-29.8 μm at 25 °C, especially strain PF07. These Pseudomonas biofilms switched into moderate hydrophobicity, and their swarming and swimming were significantly inhibited at low temperature. Furthermore, the resistance to NaClO and heating at 65 °C apparently enhanced for mature biofilm formed at 4 °C, indicating the difference in EPS matrix production influenced the stress resistance of biofilm. In addition, three strains contained alg and psl operons for exopolysaccharide biosynthesis, and biofilm related genes of algK, pslA, rpoS, and luxR were significantly up-regulated, while flgA gene was down-regulated at 4 °C compared to 25 °C, consistent with the above phenotype changes. Thus, the dramatic increase of mature biofilm and their stress resistance in psychrotrophic Pseudomonas were associated with large secretion and protection of extracellular matrix under low temperature, which provide a theoretical basis for subsequent biofilm control during cold chain.}, }
@article {pmid36906303, year = {2023}, author = {Zarei, M and Paknejad, M and Eskandari, MH}, title = {Sublethal chlorine stress promotes the biofilm-forming ability of Salmonella enterica serovars enteritidis and expression of the related genes.}, journal = {Food microbiology}, volume = {112}, number = {}, pages = {104232}, doi = {10.1016/j.fm.2023.104232}, pmid = {36906303}, issn = {1095-9998}, abstract = {Chlorine treatment is the most common disinfection method in food-related environments. In addition to being simple and inexpensive, this method is very effective if used properly. However, insufficient chlorine concentrations only cause a sublethal oxidative stress in the bacterial population and may alter the growth behavior of stressed cells. In the present study, the effect of sublethal chlorine stress on the biofilm formation characteristics of Salmonella Enteritidis was evaluated. Our results demonstrated that, sublethal chlorine stress (350 ppm total chlorine) activates the biofilm (csgD, agfA, adrA and bapA) and quorum-sensing (sdiA and luxS) related genes in planktonic cells of S. Enteritidis. The higher expression of these genes illustrated that the chlorine stress induced the initiation of the biofilm formation process in S. Enteritidis. Results of the initial attachment assay confirmed this finding. In addition, the number of chlorine-stressed biofilm cells was significantly higher than non-stressed biofilm cells after 48 h incubation at 37 °C. In S. Enteritidis ATCC 13076 and S. Enteritidis KL19, the number of chlorine-stressed biofilm cells were 6.93 ± 0.48 and 7.49 ± 0.57 log CFU/cm[2], while the number of non-stressed biofilm cells were 5.12 ± 0.39 and 5.63 ± 0.51 log CFU/cm[2], respectively. These findings were confirmed by measurements of the major components of biofilm, i.e., eDNA, protein and carbohydrate. The amount of these components in 48-h biofilms was higher when the cells were initially subjected to sublethal chlorine stress. However, the up-regulation of the biofilm and quorum sensing genes was not observed in 48-h biofilm cells, indicating that the effect of chlorine stress had vanished in the subsequent generations of Salmonella. In total, these results revealed that sublethal chlorine concentrations can promote the biofilm-forming ability of S Enteritidis.}, }
@article {pmid36905831, year = {2023}, author = {Guo, W and Li, Y and Wang, S and Wang, Y and Li, C and Jin, Y and Li, Y and Chen, X and Miao, W}, title = {Photodynamic nano hydroxyapatite with biofilm penetration capability for dental plaque eradication and prevention of demineralization.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {225}, number = {}, pages = {113242}, doi = {10.1016/j.colsurfb.2023.113242}, pmid = {36905831}, issn = {1873-4367}, abstract = {Dental caries represents one of the most prevalent diseases worldwide, characteristic of the growth of dental plaque and demineralization of tooth enamel. Current medications for eradication of dental plaques and prevention of demineralization suffer from several limitations to overcome, calling for novel strategies with great potency in eliminating cariogenic bacteria and dental plaque that forms, as well as in inhibiting the demineralization of enamel, into an integrated system. Considering the potency of photodynamic therapy in bacteria inactivation and the composition of enamel, we herein report that the novel photodynamic nano hydroxyapatite (nHAP), named Ce6 @QCS/nHAP, was useful for this purpose. Ce6 @QCS/nHAP, comprised of quaternary chitosan (QCS)-coated nHAP loaded with chlorin e6 (Ce6), exhibited good biocompatibility and non-compromised photodynamic activity. In vitro studies revealed that Ce6 @QCS/nHAP could effectively associate with cariogenic Streptococcus mutans (S. mutans), leading to a significant antibacterial effect through photodynamic killing and physical inactivation against the planktonic microbe. Three-dimensional fluorescence imaging suggested that Ce6 @QCS/nHAP exhibited a superior S. mutans biofilm penetration capacity to free Ce6, resulting in effective dental plaque eradiation when light irradiation was applied. The number of surviving bacteria in biofilm was at least 2.8 log units lower in the Ce6 @QCS/nHAP group compared to that in the free Ce6 group. Further, in the S. mutans biofilm-infected artificial tooth model, treatment with Ce6 @QCS/nHAP also resulted in the significant prevention of hydroxyapatite disks from demineralization, with lower percentage of fragmentation and weight loss These data suggest that our photodynamic nanosystem can effectively eradicate dental plaque while also significantly protecting artificial tooth from demineralization, opening up new possibilities in treating bacterium-associated dental caries.}, }
@article {pmid36905317, year = {2023}, author = {Sharma, R and Johnson, RH and David, GR and Rahimifar, M and Heidari, A}, title = {A Case of Coccidioidal Meningitis With Biofilm Obstructing VP Shunt Due to Cutibacterium acnes.}, journal = {Journal of investigative medicine high impact case reports}, volume = {11}, number = {}, pages = {23247096231159810}, doi = {10.1177/23247096231159810}, pmid = {36905317}, issn = {2324-7096}, abstract = {Herein described is a case of biofilm obstructing ventriculoperitoneal shunt due to Cutibacteirum acnes infection in a patient with coccidioidal meningitis. Cutibacterium acnes infects and obstructs cerebral shunts by the production of biofilm; however, diagnosis is usually missed by routine aerobic cultures. Obtaining anaerobic cultures routinely in patients with foreign body implants leading to central nervous system infections could prevent a missed diagnosis of this pathogen. Penicillin G is the first-line treatment.}, }
@article {pmid36904487, year = {2023}, author = {Cremer, J and Kaltschmidt, BP and Kiel, A and Eberhard, J and Schmidt, S and Kaltschmidt, C and Kaltschmidt, B and Hütten, A and Anselmetti, D}, title = {Aging of Industrial Polypropylene Surfaces in Detergent Solution and Its Consequences for Biofilm Formation.}, journal = {Polymers}, volume = {15}, number = {5}, pages = {}, doi = {10.3390/polym15051247}, pmid = {36904487}, issn = {2073-4360}, abstract = {The performance of plastic components in water-bearing parts of industrial and household appliances, often in the presence of harsh environments and elevated temperatures, critically relies on the mechanical and thermal polymer stability. In this light, the precise knowledge of aging properties of polymers formulated with dedicated antiaging additive packages as well as various fillers is crucial for long-time device warranty. We investigated and analysed the time-dependent, polymer-liquid interface aging of different industrial performance polypropylene samples in aqueous detergent solution at high temperatures (95 °C). Special emphasis was put on the disadvantageous process of consecutive biofilm formation that often follows surface transformation and degradation. Atomic force microscopy, scanning electron microscopy, and infrared spectroscopy were used to monitor and analyse the surface aging process. Additionally, bacterial adhesion and biofilm formation was characterised by colony forming unit assays. One of the key findings is the observation of crystalline, fibre-like growth of ethylene bis stearamide (EBS) on the surface during the aging process. EBS is a widely used process aid and lubricant enabling the proper demoulding of injection moulding plastic parts. The aging-induced surface-covering EBS layers changed the surface morphology and promoted bacterial adhesion as well as biofilm formation of Pseudomonas aeruginosa.}, }
@article {pmid36904479, year = {2023}, author = {Mačák, L and Velgosova, O and Múdra, E and Vojtko, M and Dolinská, S}, title = {Transfer of AgNPs' Anti-Biofilm Activity into the Nontoxic Polymer Matrix.}, journal = {Polymers}, volume = {15}, number = {5}, pages = {}, doi = {10.3390/polym15051238}, pmid = {36904479}, issn = {2073-4360}, abstract = {A biological method was successfully applied to synthesize spherical silver nanoparticles (AgNPs) while using the extract of lavender (Ex-L) (lat. Lavandula angustifolia) as the reducing and stabilizing agent. The produced nanoparticles were spherical with an average size of 20 nm. The AgNPs' synthesis rate confirmed the extract's excellent ability to reduce silver nanoparticles from the AgNO3 solution. The presence of good stabilizing agents was confirmed by the excellent stability of the extract. Nanoparticles' shapes and sizes did not change. UV-Vis absorption spectrometry, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to characterize the silver nanoparticles. The silver nanoparticles were incorporated into the PVA polymer matrix by the "ex situ" method. The polymer matrix composite with AgNPs was prepared in two ways: as a composite film and nanofibers (nonwoven textile). The anti-biofilm activity of AgNPs and the ability of AgNPs to transfer toxic properties into the polymer matrix were proved.}, }
@article {pmid36903742, year = {2023}, author = {Okamoto, K and Kudo, D and Phuong, DND and Iwamoto, Y and Watanabe, K and Yoshioka, Y and Ariyoshi, W and Yamasaki, R}, title = {Magnesium Hydroxide Nanoparticles Inhibit the Biofilm Formation of Cariogenic Microorganisms.}, journal = {Nanomaterials (Basel, Switzerland)}, volume = {13}, number = {5}, pages = {}, doi = {10.3390/nano13050864}, pmid = {36903742}, issn = {2079-4991}, abstract = {Although various caries-preventive agents have been developed, dental caries is still a leading global disease, mostly caused by biological factors such as mutans streptococci. Magnesium hydroxide nanoparticles have been reported to exhibit antibacterial effects; however, they are rarely used in oral care practical applications. In this study, we examined the inhibitory effect of magnesium hydroxide nanoparticles on biofilm formation by Streptococcus mutans and Streptococcus sobrinus-two typical caries-causing bacteria. Three different sizes of magnesium hydroxide nanoparticles (NM80, NM300, and NM700) were studied, all of which inhibited biofilm formation. The results showed that the nanoparticles were important for the inhibitory effect, which was not influenced by pH or the presence of magnesium ions. We also determined that the inhibition process was mainly contact inhibition and that medium (NM300) and large (NM700) sizes were particularly effective in this regard. The findings of our study demonstrate the potential applications of magnesium hydroxide nanoparticles as caries-preventive agents.}, }
@article {pmid36903577, year = {2023}, author = {Tran, HQ and Alam, H and Goff, A and Daeneke, T and Bhave, M and Yu, A}, title = {Multifunctional Fe3O4 Nanoparticles Filled Polydopamine Hollow Rods for Antibacterial Biofilm Treatment.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {5}, pages = {}, doi = {10.3390/molecules28052325}, pmid = {36903577}, issn = {1420-3049}, abstract = {This work reports the use of mesoporous silica rods as templates for the step-wise preparation of multifunctional Fe3O4 NPs filled polydopamine hollow rods (Fe3O4@PDA HR). The capacity of as-synthesized Fe3O4@PDA HR as a new drug carrier platform was assessed by its loading and the triggered release of fosfomycin under various stimulations. It was found that the release of fosfomycin was pH dependent with ~89% of fosfomycin being released in pH 5 after 24 h, which was 2-fold higher than that in pH 7. The magnetic properties of Fe3O4 NPs and the photothermal properties of PDA enabled the triggered release of fosfomycin upon the exposure to rotational magnetic field, or NIR laser irradiation. Additionally, the capability of using multifunctional Fe3O4@PDA HR to eliminate preformed bacterial biofilm was demonstrated. Upon exposure to the rotational magnetic field, the biomass of a preformed biofilm was significantly reduced by 65.3% after a 20 min treatment with Fe3O4@PDA HR. Again, due to the excellent photothermal properties of PDA, a dramatic biomass decline (72.5%) was achieved after 10 min of laser exposure. This study offers an alternative approach of using drug carrier platform as a physical mean to kill pathogenic bacteria along with its traditional use for drug delivery.}, }
@article {pmid36903518, year = {2023}, author = {Zhang, Z and Zhao, Y and Cai, J and Wang, T and Song, Y and Lu, J and Du, H and Wang, W and Zhao, Y and Guo, L}, title = {Optimized Extraction, Identification and Anti-Biofilm Action of Wu Wei Zi (Fructus Schisandrae Chinensis) Extracts against Vibrio parahaemolyticus.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {5}, pages = {}, doi = {10.3390/molecules28052268}, pmid = {36903518}, issn = {1420-3049}, abstract = {The pathogenicity of foodborne Vibrio parahaemolyticus is a major concern for global public health. This study aimed to optimize the liquid-solid extraction of Wu Wei Zi extracts (WWZE) against Vibrio parahaemolyticus, identify its main components, and investigate the anti-biofilm action. The extraction conditions optimized by the single-factor test and response surface methodology were ethanol concentration of 69%, temperature at 91 °C, time of 143 min, and liquid-solid ratio of 20:1 mL/g. After high performance liquid chromatography (HPLC) analysis, it was found that the main active ingredients of WWZE were schisandrol A, schisandrol B, schisantherin A, schisanhenol, and schisandrin A-C. The minimum inhibitory concentration (MIC) of WWZE, schisantherin A, and schisandrol B measured by broth microdilution assay was 1.25, 0.625, and 1.25 mg/mL, respectively, while the MIC of the other five compounds was higher than 2.5 mg/mL, indicating that schisantherin A and schizandrol B were the main antibacterial components of WWZE. Crystal violet, Coomassie brilliant blue, Congo red plate, spectrophotometry, and Cell Counting Kit-8 (CCK-8) assays were used to evaluate the effect of WWZE on the biofilm of V. parahaemolyticus. The results showed that WWZE could exert its dose-dependent potential to effectively inhibit the formation of V. parahaemolyticus biofilm and clear mature biofilm by significantly destroying the cell membrane integrity of V. parahaemolyticus, inhibiting the synthesis of intercellular polysaccharide adhesin (PIA), extracellular DNA secretion, and reducing the metabolic activity of biofilm. This study reported for the first time the favorable anti-biofilm effect of WWZE against V. parahaemolyticus, which provides a basis for deepening the application of WWZE in the preservation of aquatic products.}, }
@article {pmid36902594, year = {2023}, author = {Popov, G and Aleksandrov, R and Petkova, V and Kaneva, R and Gergova, R and Kundurzhiev, T and Popova, D}, title = {Analysis of Bacterial Biofilm Formation and MUC5AC and MUC5B Expression in Chronic Rhinosinusitis Patients.}, journal = {Journal of clinical medicine}, volume = {12}, number = {5}, pages = {}, doi = {10.3390/jcm12051808}, pmid = {36902594}, issn = {2077-0383}, abstract = {Chronic rhinosinusitis (CRS) is a condition affecting as much as 16% of the adult population in developed countries with many factors attributed to its development, including the more recently proposed role of bacterial biofilm infections. Plenty of research has been conducted on biofilms in CRS and the causes behind the development of such an infection in the nasal cavity and sinuses. One such probable cause is the production of mucin glycoproteins by the mucosa of the nasal cavity. To investigate the possible link between biofilm formation and mucin expression levels and their relationship with CRS etiology, we examined samples from 85 patients by means of spinning disk confocal microscopy (SDCM) to establish their biofilm status and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to determine MUC5AC and MUC5B expression levels. We observed a significantly higher prevalence of bacterial biofilms in the CRS patient group compared to the control group. In addition, we detected higher expression levels of MUC5B but not MUC5AC in the CRS group, which suggested a possible role for MUC5B in CRS development. Finally, we found no direct relationship between biofilm presence and mucin expression levels, thereby showing a multifaceted connection between these two major factors implicated in CRS etiology.}, }
@article {pmid36902413, year = {2023}, author = {Parvin, F and Rahman, MA and Deva, AK and Vickery, K and Hu, H}, title = {Staphylococcus aureus Cell Wall Phenotypic Changes Associated with Biofilm Maturation and Water Availability: A Key Contributing Factor for Chlorine Resistance.}, journal = {International journal of molecular sciences}, volume = {24}, number = {5}, pages = {}, doi = {10.3390/ijms24054983}, pmid = {36902413}, issn = {1422-0067}, abstract = {Staphylococcus aureus biofilms are resistant to both antibiotics and disinfectants. As Staphylococci cell walls are an important defence mechanism, we sought to examine changes to the bacterial cell wall under different growth conditions. Cell walls of S. aureus grown as 3-day hydrated biofilm, 12-day hydrated biofilm, and 12-day dry surface biofilm (DSB) were compared to cell walls of planktonic organisms. Additionally, proteomic analysis using high-throughput tandem mass tag-based mass spectrometry was performed. Proteins involved in cell wall synthesis in biofilms were upregulated in comparison to planktonic growth. Bacterial cell wall width (measured by transmission electron microscopy) and peptidoglycan production (detected using a silkworm larva plasma system) increased with biofilm culture duration (p < 0.001) and dehydration (p = 0.002). Similarly, disinfectant tolerance was greatest in DSB, followed by 12-day hydrated biofilm and then 3-day biofilm, and it was least in the planktonic bacteria--suggesting that changes to the cell wall may be a key factor for S. aureus biofilm biocide resistance. Our findings shed light on possible new targets to combat biofilm-related infections and hospital dry surface biofilms.}, }
@article {pmid36902169, year = {2023}, author = {Charęza, M and Przygrodzka, K and Żywicka, A and Grygorcewicz, B and Sobolewski, P and Mozia, S and Śmiglak, M and Drozd, R}, title = {Enhancement of Inhibition of the Pseudomonas sp. Biofilm Formation on Bacterial Cellulose-Based Wound Dressing by the Combined Action of Alginate Lyase and Gentamicin.}, journal = {International journal of molecular sciences}, volume = {24}, number = {5}, pages = {}, doi = {10.3390/ijms24054740}, pmid = {36902169}, issn = {1422-0067}, abstract = {Bacterial biofilms generally contribute to chronic infections, including wound infections. Due to the antibiotic resistance mechanisms protecting bacteria living in the biofilm, they are a serious problem in the wound healing process. To accelerate the wound healing process and avoid bacterial infection, it is necessary to select the appropriate dressing material. In this study, the promising therapeutic properties of alginate lyase (AlgL) immobilised on BC membranes for protecting wounds from Pseudomonas aeruginosa infection were investigated. The AlgL was immobilised on never dried BC pellicles via physical adsorption. The maximum adsorption capacity of AlgL was 6.0 mg/g of dry BC, and the equilibrium was reached after 2 h. The adsorption kinetics was studied, and it has been proven that the adsorption was consistent with Langmuir isotherm. In addition, the impact of enzyme immobilisation on bacterial biofilm stability and the effect of simultaneous immobilisation of AlgL and gentamicin on the viability of bacterial cells was investigated. The obtained results showed that the AlgL immobilisation significantly reduced the amount of polysaccharides component of the P. aeruginosa biofilm. Moreover, the biofilm disruption by AlgL immobilised on BC membranes exhibited synergism with the gentamicin, resulting in 86.5% more dead P. aeruginosa PAO-1 cells.}, }
@article {pmid36900736, year = {2023}, author = {Saengphen, T and Koontongkaew, S and Utispan, K}, title = {Effectiveness of a Combined Toothbrushing Technique on Cariogenic Dental Biofilm in Relation to Stainless Steel and Elastomeric Ligatures in Orthodontic Patients: A Randomized Clinical Trial.}, journal = {Healthcare (Basel, Switzerland)}, volume = {11}, number = {5}, pages = {}, doi = {10.3390/healthcare11050731}, pmid = {36900736}, issn = {2227-9032}, abstract = {Increased dental biofilm commonly occurs during orthodontic treatment. The aim of this study was to evaluate the effect of a combined toothbrushing method on dental biofilm cariogenicity in patients with stainless steel (SSL) and elastomeric (EL) ligatures. At baseline (T1), 70 participants were randomized (1:1 ratio) to the SSL or EL group. Dental biofilm maturity was evaluated using a three-color-disclosing dye. The participants were instructed to brush their teeth using a combined horizontal-Charters-modified Bass technique. Dental biofilm maturity was reassessed at the 4-week follow-up (T2). We found that at T1, new dental biofilm was the highest, followed by mature and cariogenic dental biofilm in the SSL group (p < 0.05). In the EL group, cariogenic dental biofilm was highly observed, followed by mature and new dental biofilm (p < 0.05). After intervention, cariogenic dental biofilm significantly decreased in both groups (p < 0.05). Moreover, a marked decrease in cariogenic dental biofilm was observed in the EL group compared with the SSL group (p < 0.05). However, the change in mature dental biofilm in the groups was similar (p > 0.05). Our results demonstrated that the combined toothbrushing method reduced cariogenic dental biofilm in the SSL and EL groups.}, }
@article {pmid36898963, year = {2023}, author = {Budil, J and StenclovÃ, P and Kromka, A and LiÅ kovÃ, P}, title = {Development of the Pseudomonas syringae Pathovar morsprunorum Biofilm Monitored in Real-Time Using Attenuated Total Reflection Fourier Transform Infrared Measurements in a Flow Cell Chamber.}, journal = {Applied spectroscopy}, volume = {}, number = {}, pages = {37028231165057}, doi = {10.1177/00037028231165057}, pmid = {36898963}, issn = {1943-3530}, abstract = {Biofilms of sessile Pseudomonas syringae cells formed on top of plant host's leaves or fruits allow surviving harsh environmental conditions (desiccation) and improve their resistance to antibacterial treatments of crops. Better understanding of these biofilms can help minimize their effect on harvests. In the present study, infrared attenuated total reflection (IR-ATR) spectroscopy with optical and confocal laser scanning microscopy have been applied to analyze Pseudomonas syringae pathovar morsprunorum biofilm development in real-time, for the first time. The biofilm development was observed within the spectral window 4000-800 cm[-1] at constant flow conditions during 72 h. The kinetics of representative integrated band areas (nucleic acids with polysaccharides at 1141-1006 cm[-1], amino acid side chains with free fatty acids at 1420-1380 cm[-1], proteins at 1580-1490 cm[-1], and lipids with proteins at 2935-2915 cm[-1]) were analyzed with regards to the observed biofilm structure and following P. syringae biofilm developmental stages were attributed: The inoculation phase, washing of weakly attached bacteria closely followed by recolonization of vacated surface, the restructuration phase, and finally the maturation phase.}, }
@article {pmid36898591, year = {2023}, author = {Ragupathi, NKD and Muthuirulandi Sethuvel, DP and Gopikrishnan, M and Dwarakanathan, HT and Murugan, D and Biswas, I and Bakthavachalam, YD and Murugesan, M and George Priya Doss, C and Monk, PN and Karunakaran, E and Veeraraghavan, B}, title = {Phage-based therapy against biofilm producers in gram-negative ESKAPE pathogens.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106064}, doi = {10.1016/j.micpath.2023.106064}, pmid = {36898591}, issn = {1096-1208}, abstract = {Persistent antibiotic use results in the rise of antimicrobial resistance with limited or no choice for multidrug-resistant (MDR) and extensively drug resistant (XDR) bacteria. This necessitates a need for alternative therapy to effectively combat clinical pathogens that are resistant to last resort antibiotics. The study investigates hospital sewage as a potential source of bacteriophages to control resistant bacterial pathogens. Eighty-one samples were screened for phages against selected clinical pathogens. Totally, 10 phages were isolated against A. baumannii, 5 phages against K. pneumoniae, and 16 phages were obtained against P. aeruginosa. The novel phages were observed to be strain-specific with complete bacterial growth inhibition of up to 6 h as monotherapy without antibiotics. Phage plus colistin combinations reduced the minimum-biofilm eradication concentration of colistin up to 16 folds. Notably, a cocktail of phages exhibited maximum efficacy with complete killing at 0.5-1 μg/ml colistin concentrations. Thus, phages specific to clinical strains have a higher edge in treating nosocomial pathogens with their proven anti-biofilm efficacy. In addition, analysis of phage genomes revealed close phylogenetic relations with phages reported from Europe, China, and other neighbouring countries. This study serves as a reference and can be extended to other antibiotics and phage types to assess optimum synergistic combinations to combat various drug resistant pathogens in the ongoing AMR crisis.}, }
@article {pmid36897105, year = {2023}, author = {Halder, M and Narula, M and Singh, Y}, title = {Supramolecular, Nanostructured Assembly of Antioxidant and Antibacterial Peptides Conjugated to Naproxen and Indomethacin for the Selective Inhibition of COX-2, Biofilm, and Inflammation in Chronic Wounds.}, journal = {Bioconjugate chemistry}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.bioconjchem.3c00014}, pmid = {36897105}, issn = {1520-4812}, abstract = {Chronic wounds are a major healthcare challenge around the world. The presence of bacterial biofilms, accumulation of reactive oxygen species (ROS), and persistent inflammation have been identified as rate-limiting steps in chronic wound healing. Anti-inflammatory drugs, like naproxen (Npx) and indomethacin (Ind), show poor selectivity for the COX-2 enzyme, which plays a key role in producing inflammatory responses. To address these challenges, we have developed conjugates of Npx and Ind with peptides possessing antibacterial, antibiofilm, and antioxidant properties along with enhanced selectivity for the COX-2 enzyme. We have synthesized and characterized peptide conjugates Npx-YYk, Npx-YYr, Ind-YYk, and Ind-YYr, which were self-assembled into supramolecular gels. As envisaged, the conjugates and gels showed high proteolytic stability and selectivity toward the COX-2 enzyme and potent antibacterial activities (>95% within 12 h) against Gram-positive bacteria Staphylococcus aureus, implicated in wound-related infections, eradication of biofilm (∼80%), and radical scavenging (>90%) properties. Cell culture studies with mouse fibroblast cells (L929) and macrophage-like cells (RAW 264.7) showed that gels were cell proliferative in nature (120% viability), which resulted in faster and more efficient scratch healing. Treatment with gels led to a significant decrease in proinflammatory cytokine (TNF-α and IL-6) expressions and an increase in anti-inflammatory gene (IL-10) expression. The gels developed in this work show great promise as a topical agent for chronic wounds or as a coating for medical devices to prevent medical-device-associated infections.}, }
@article {pmid36894813, year = {2023}, author = {Kalashnikova, TV and Sutormina, LV and Samoilova, ZY and Oktyabrsky, ON and Smirnova, GV}, title = {Effect of Changes in the Redox Status on Biofilm Formation in Escherichia coli.}, journal = {Bulletin of experimental biology and medicine}, volume = {}, number = {}, pages = {}, pmid = {36894813}, issn = {1573-8221}, abstract = {Changes in the redox balance in the medium and in Escherichia coli cells significantly affect the ability of bacteria to form biofilms. An increase in the level of aeration in the culture of wild-type bacteria led to a 3-fold decrease in the mass of biofilms. Mutants lacking components of the glutathione and thioredoxin redox systems, as well as transporters involved in the transmembrane cycling of glutathione, demonstrated increased biofilm formation ability. The effect of exogenous glutathione on biofilm formation depended on the culturing conditions. The addition of 0.1-1 mM Trolox (a water-soluble analog of vitamin E) was accompanied by a 30-40% reduction in biofilm formation.}, }
@article {pmid36893978, year = {2023}, author = {Abdelhak, S and Menard, Y and Artigas, J}, title = {Effects of global change on the ability of stream biofilm to dissipate the herbicide glyphosate.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {324}, number = {}, pages = {121406}, doi = {10.1016/j.envpol.2023.121406}, pmid = {36893978}, issn = {1873-6424}, abstract = {The herbicide glyphosate is contaminating a large number of freshwater ecosystems worldwide and its fate and effects remains uncertain in light of the effects of global change. The present study examines how variations in water temperature and light availability relative to global change affect the ability of stream biofilms to degrade the herbicide glyphosate. Biofilms were exposed in microcosms to two levels of water temperature simulating global warming (Ambient = 19-22 °C and Warm = 21-24 °C) and three levels of light representative of riparian habitat destruction due to land use change (Dark = 0, Intermediate = 600, High = 1200 μmol photons m[-2] s[-1]). Biofilms were acclimated to six different experimental treatments, namely i) ambient temperature without light (AMB_D), ii) ambient temperature and intermediate light (AMB_IL), iii) ambient temperature and high light (AMB_HL), iv) warm temperature without light (WARM_D), v) warm temperature and intermediate light (WARM_IL) and vi) warm temperature and high light (WARM_HL). The ability of biofilms to degrade 50 μg L[-1] of glyphosate was tested. Results showed that water temperature increase, but not light availability increase, significantly increased aminomethyl phosphonic acid (AMPA) production by biofilms. However, the combined increase of temperature and light generated the shortest time to dissipate half of the glyphosate supplied and/or half of the maximum AMPA produced (6.4 and 5.4 days, respectively) by biofilms. Despite light had a major effect in modulating biofilm structural and functional descriptors, the response of certain descriptors (i. e. chlorophyll-a concentration, bacterial density and diversity, nutrient content and PHO activity) to light availability increase depended on water temperature. Specifically, the biofilms in the WARM_HL treatment displayed the highest Glucosidase: Peptidase and Glucosidase: Phosphatase enzyme activity ratios and the lowest biomass C: N molar ratios compared to the other treatments. According to these results, warmer temperatures and high light availability could have been exacerbating the decomposition of organic C compounds in biofilms, including the use of glyphosate as a C source for microbial heterotrophs. This study shows that ecoenzymatic stoichiometry and xenobiotic biodegradation approaches can be combined to better understand the functioning of biofilms in pesticide-polluted streams.}, }
@article {pmid36893665, year = {2023}, author = {Meng, X and Xiong, H and Ji, F and Gao, X and Han, L and Wu, Z and Jia, L and Ren, J}, title = {Facile surface treatment strategy to generate dense lysozyme layer on ultra-high molecular weight polyethylene enabling inhibition of bacterial biofilm formation.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {225}, number = {}, pages = {113243}, doi = {10.1016/j.colsurfb.2023.113243}, pmid = {36893665}, issn = {1873-4367}, abstract = {Medical plastics such as those found in endotracheal tubes are widely used in intensive care units for the treatment of critically ill patients. Although commonplace in hospital environment, these catheters are at a high risk of bacterial contamination and have been found responsible for numerous health-care-associated infections. Antimicrobial coatings that can prevent harmful bacterial growth are required to reduce the occurrence of such infections. In this study, we introduce a facile surface treatment strategy that could form antimicrobial coatings on the surface of average medical plastics. The strategy involves treatment of activated surfaces with lysozyme, a natural antimicrobial enzyme presenting in human lacrimal gland secretions which is widely used for wound healing. Using ultra-high molecular weight polyethylene (UHMWPE) as the representative surface, oxygen/argon plasma treatment for 3 min led to the increase of surface roughness and the generation of negatively charged groups, with the zeta potential measured as -94.5 mV at pH 7. The activated surface could accommodate lysozyme with a density of up to 0.3 nmol/cm[2] through electrostatic interaction. Antimicrobial activity of the resulting surface (UHMWPE@Lyz) was characterized with Escherichia coli and Pseudomonas sp. strains, and the treated surface significantly inhibited the bacterial colonization and the formation of biofilm compared to the untreated UHMWPE. This method of constructing an effective lysozyme-based antimicrobial coating is a generally applicable, simple and fast process for surface treatment with no adverse solvent and wastes involved.}, }
@article {pmid36893426, year = {2023}, author = {Li, X and Kong, R and Wang, J and Wu, J and He, K and Wang, X}, title = {The formation mechanism of Bacillus subtilis biofilm surface morphology under competitive environment.}, journal = {Canadian journal of microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1139/cjm-2023-0014}, pmid = {36893426}, issn = {1480-3275}, abstract = {Material properties and growth environments affect the surface morphology of biofilms. Taken the biofilm growing in competitive environments as the object, which is compared with the single biofilm, we find that the competitive environment has an impact on the biofilm thickness and wrinkle pattens. Through Diffusion Limited Growth (DLG) theoretical model analysis, it shows that the competitive environment is caused by cell competing for nutrition, and the competitive environment reacts on biofilm which affect the phenotypic differentiation, causing changes in the stiffness of the biofilm. Using the theoretical and finite element simulation, we compare these results of bi-layer and tri-layer film-substrate models with experimental observations, and find that tri-layer film-substrate model is in line with the reality, which means that the layer between the biofilm and substrate plays an import role for wrinkle formation. Based on the above analysis, we further study effects of biofilm stiffness and interlayer thickness on wrinkles under competitive environment.}, }
@article {pmid36890534, year = {2023}, author = {Zhu, M and Dang, J and Dong, F and Zhong, R and Zhang, J and Pan, J and Li, Y}, title = {Antimicrobial and cleaning effects of ultrasonic-mediated plasma-loaded microbubbles on Enterococcus faecalis biofilm: an in vitro study.}, journal = {BMC oral health}, volume = {23}, number = {1}, pages = {133}, pmid = {36890534}, issn = {1472-6831}, mesh = {Humans ; *Enterococcus faecalis ; Hydrogen Peroxide/pharmacology ; Ultrasonics ; Microbubbles ; Root Canal Irrigants/pharmacology ; *Anti-Infective Agents/pharmacology ; Biofilms ; Sodium Hypochlorite/pharmacology ; Dental Pulp Cavity ; Dentin ; Microscopy, Confocal ; }, abstract = {BACKGROUND: Enterococcus faecalis (E. faecalis) is the most frequently isolated bacteria from teeth with root canal treatment failure. This study aims to evaluate the disinfection effect of ultrasonic-mediated cold plasma-loaded microbubbles (PMBs) on 7d E. faecalis biofilm, the mechanical safety and the mechanisms.<br><br>METHODS: The PMBs were fabricated by a modified emulsification process and the key reactive species, nitric oxide (NO) and hydrogen peroxide (H2O2) were evaluated. The 7d E. faecalis biofilm on human tooth disk was constructed and divided into the following groups: PBS, 2.5%NaOCl, 2%CHX, and different concentrations of PMBs (10[8]&#xa0;mL[-1], 10[7]&#xa0;mL[-1]). The disinfection effects and elimination effects were verified with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Microhardness and roughness change of dentin after PMBs treatment were verified respectively.<br><br>RESULTS: The concentration of NO and H2O2 in PMBs increased by 39.99% and 50.97% after ultrasound treatment (p&#x2009;<&#x2009;0.05) respectively. The CLSM and SEM results indicate that PMBs with ultrasound treatment could remove the bacteria and biofilm components effectively, especially those living in dentin tubules. The 2.5% NaOCl presented an excellent effect against biofilm on dishes, but the elimination effect on dentin tubules is limited. The 2% CHX group exhibits significant disinfection effect. The biosafety tests indicated that there is no significant changes on microhardness and roughness after PMBs with ultrasound treatment (p&#x2009;>&#x2009;0.05).<br><br>CONCLUSION: PMBs combined with ultrasound treatment exhibited significant disinfection effect and biofilm removal effect, the mechanical safety is acceptable.}, }
@article {pmid36890147, year = {2023}, author = {Maknuna, L and Tran, VN and Lee, BI and Kang, HW}, title = {Inhibitory effect of 405 nm laser light on bacterial biofilm in urethral stent.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {3908}, pmid = {36890147}, issn = {2045-2322}, abstract = {The clinical use of urethral stents is usually complicated by various adverse effects, including dysuria, fever, and urinary tract infection (UTI). Biofilms (formed by bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) adhering to the stent cause UTIs in stented patients (approximately 11%). The undesirable consequences of antibiotics use include bacterial resistance, weight gain, and type 1 diabetes, which occur when antibiotics are used for a long time. We aimed to assess the efficacy of a new optical treatment with a 405 nm laser to inhibit bacterial growth in a urethral stent in vitro. The urethral stent was grown in S. aureus broth media for three days to induce biofilm formation under dynamic conditions. Various irradiation times with the 405 nm laser light were tested (5, 10, and 15 min). The efficacy of the optical treatment on biofilms was evaluated quantitatively and qualitatively. The production of reactive oxygen species helped eliminate the biofilm over the urethral stent after 405 nm irradiation. The inhibition rate corresponded to a 2.2 log reduction of colony-forming units/mL of bacteria after 0.3 W/cm[2] of irradiation for 10 min. The treated stent showed a significant reduction in biofilm formation compared with the untreated stent, as demonstrated by SYTO 9 and propidium iodide staining. MTT assays using the CCD-986sk cell line revealed no toxicity after 10 min of irradiation. We conclude that optical treatment with 405 nm laser light inhibits bacterial growth in urethral stents with no or minimal toxicity.}, }
@article {pmid36889408, year = {2023}, author = {Feng, L and Sun, FY and Yang, J and Cui, D and Li, ZH and Pi, S and Zhao, HP and Li, A}, title = {Intracellular electron competition in response to the oxygen pressure of the aerobic denitrification process in an O2-based membrane biofilm reactor (MBfR) for nitrate removal.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162592}, doi = {10.1016/j.scitotenv.2023.162592}, pmid = {36889408}, issn = {1879-1026}, abstract = {This study quantitatively investigated the effect of dissolved oxygen (DO) concentration on aerobic denitrification, and showed the mechanism of aerobic denitrification from the perspective of electron competition by cultivating Pseudomonas stutzeri T13, a typical aerobic denitrifier, in an oxygen-based membrane biofilm reactor (O2-based MBfR). The experiments showed that when the O2 pressure increased from 2 to 10 psig (psig), the averaged effluent DO during steady-state phases increased from 0.02 to 4.23 mg/L, and the corresponding mean NO3[-]-N removal efficiency slightly decreased from 97.2 % to 90.9 %. Compared to the maximum theoretical flux of O2 in various phases, the actual O2 transfer flux increased from a limited status (2.07 e[-] eq m[-2] d[-1] at 2 psig) to an excessive status (5.58 e[-] eq m[-2] d[-1] at 10 psig). The increase of DO inhibited the electron availability for aerobic denitrification, which decreased from 23.97 % to 11.46 %, accompanying the increased electron availability for aerobic respiration from 15.87 % to 28.36 %. Unlike the napA and norB genes, the expression of the nirS and nosZ genes was significantly affected by DO, with the highest relative fold-changes of 6.5 and 6.13 at 4 psig O2, respectively. The results contribute to clarifying the mechanism of aerobic denitrification either from quantitative perspective of electron distribution and qualitative perspective of gene expression, which benefits the regulation and practical application of aerobic denitrification for wastewater treatment.}, }
@article {pmid36889402, year = {2023}, author = {Afonso, AC and Gomes, IB and Saavedra, MJ and Simões, L and Simões, M}, title = {Drinking-water isolated Delftia acidovorans selectively coaggregates with partner bacteria and facilitates multispecies biofilm development.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162646}, doi = {10.1016/j.scitotenv.2023.162646}, pmid = {36889402}, issn = {1879-1026}, abstract = {Coaggregation plays an important role in the development of multispecies biofilms in different environments, often serving as an active bridge between biofilm members and other organisms that, in their absence, would not integrate the sessile structure. The ability of bacteria to coaggregate has been reported for a limited number of species and strains. In this study, 38 bacterial strains isolated from drinking water (DW) were investigated for their ability to coaggregate, in a total of 115 pairs of combinations. Among these isolates, only Delftia acidovorans (strain 005P) showed coaggregating ability. Coaggregation inhibition studies have shown that the interactions mediating D. acidovorans 005P coaggregation were both polysaccharide-protein and protein-protein, depending on the interacting partner bacteria. Dual-species biofilms of D. acidovorans 005P and other DW bacteria were developed to understand the role of coaggregation on biofilm formation. Biofilm formation by Citrobacter freundii and Pseudomonas putida strains highly benefited from the presence of D. acidovorans 005P, apparently due to the production of extracellular molecules/public goods favouring microbial cooperation. This was the first time that the coaggregation capacity of D. acidovorans was demonstrated, highlighting its role in providing a metabolic opportunity for partner bacteria.}, }
@article {pmid36888841, year = {2023}, author = {Santos, VCED and Maquera-Huacho, PM and Imbriani, MJM and Minhaco, VMTR and Spolidorio, DMP}, title = {Effects of BlueM® against Streptococcus mutans biofilm and its virulence gene expression.}, journal = {Brazilian dental journal}, volume = {34}, number = {1}, pages = {19-28}, doi = {10.1590/0103-6440202305133}, pmid = {36888841}, issn = {1806-4760}, abstract = {This study evaluated the antimicrobial capacity of BlueM® mouthwash against the bacterium Streptococcus mutans and its influence on gbpA gene expression as well as its cytotoxic effect on fibroblast cells. BlueM® showed antimicrobial activity, with MIC and MBC values of 0.005% and 0.01%, respectively. The MBIC was 6.25% for S. mutans. CFU count and confocal microscopy revealed significant effect of BlueM® on S. mutans biofilm pre-formed on dentin surfaces. Interestingly, the analysis of gbpA gene expression indicated a decrease in gene expression after 15 min of treatment with BlueM® at a concentration of 25%. Moreover, BlueM® exhibited low levels of cytotoxicity. In conclusion, our results showed the antimicrobial effectiveness of BlueM® against S. mutans, its ability to modulate the expression of the gbpA gene and its low cytotoxicity. This study supports the therapeutic potential of BlueM® as an alternative agent for the control of oral biofilm.}, }
@article {pmid36884153, year = {2023}, author = {Memar, MY and Yekani, M and Farajnia, S and Ghadiri Moghaddam, F and Nabizadeh, E and Sharifi, S and Maleki Dizaj, S}, title = {Antibacterial and biofilm-inhibitory effects of vancomycin-loaded mesoporous silica nanoparticles on methicillin-resistant staphylococcus aureus and gram-negative bacteria.}, journal = {Archives of microbiology}, volume = {205}, number = {4}, pages = {109}, pmid = {36884153}, issn = {1432-072X}, abstract = {The present study aimed to prepare and characterize vancomycin-loaded mesoporous silica nanoparticles (Van-MSNs) to detect inhibitory effects on the planktonic and biofilm forms of methicillin-resistant Staphylococcus aureus (MRSA) isolates, and study the biocompatibility and toxicity of Van-MSNs in vitro as well as antibacterial activity of Van-MSNs against Gram-negative bacteria. The inhibitory effects of Van-MSNs were investigated on MRSA using the determination of minimum inhibitory (MIC) and minimum biofilm-inhibitory concentrations (MBIC) as well as the effect on bacterial attachment. Biocompatibility was studied by examining the effect of Van-MSNs on the lysis and sedimentation rate of red blood cells (RBC). The interaction of Van-MSNs with human blood plasma was detected by the SDS-PAGE approach. The cytotoxic effect of the Van-MSNs on human bone marrow mesenchymal stem cells (hBM-MSCs) was evaluated by the MTT assay. The antibacterial effects of vancomycin and Van-MSNs on Gram-negative bacteria were also investigated using MIC determination using the broth microdilution method. Furthermore, bacteria outer membrane (OM) permeabilization was determined. Van-MSNs showed inhibitory effects on planktonic and biofilm forms of bacteria on all isolates at levels lower than MICs and MBICs of free vancomycin, but the antibiofilm effect of Van-MSNs was not significant. However, Van-MSNs did not affect bacterial attachment to surfaces. Van-loaded MSNs did not show a considerable effect on the lysis and sedimentation of RBC. A low interaction of Van-MSNs was detected with albumin (66.5 kDa). The hBM-MSCs viability in exposure to different levels of Van-MSNs was 91-100%. MICs of ≥ 128 µg/mL were observed for vancomycin against all Gram-negative bacteria. In contrast, Van-MSNs exhibited modest antibacterial activity inhibiting the tested Gram-negative bacterial strains, at concentrations of ≤ 16 µg/mL. Van-MSNs increased the OM permeability of bacteria that can increase the antimicrobial effect of vancomycin. According to our findings, Van-loaded MSNs have low cytotoxicity, desirable biocompatibility, and antibacterial effects and can be an option for the battle against planktonic MRSA.}, }
@article {pmid36883149, year = {2022}, author = {Makhrmash, JH and Al-Aidy, SR and Qaddoori, BH}, title = {Investigation of Biofilm Virulence Genes Prevalence in Klebsiella pneumoniae Isolated from the Urinary Tract Infections.}, journal = {Archives of Razi Institute}, volume = {77}, number = {4}, pages = {1421-1427}, pmid = {36883149}, issn = {2008-9872}, abstract = {Klebsiella pneumonia is a pathogen and an agent that causes hospital-acquired infections. Klebsiella pneumonia is the first and most common causative agent in community-acquired infections and urinary tract diseases. This study aimed to detect common genes, (i.e., fimA, mrkA, and mrkD) in the isolates of K. pneumoniae, isolated from urine specimens using the polymerase chain reaction (PCR) method. The isolates of K. pneumoniae were collected from urine specimens in health centers in Wasit Governorate, Iraq, and diagnosed using Analytical Profile Index 20Eand 16S rRNA techniques. The microtiter plate (MTP) method was used to detect biofilm formation. A total of 56 isolates were identified as K. pneumonia cases. The results led to the detection of biofilms; accordingly, all K. pneumoniae isolates showed biofilm production by MTP, however, at different levels. The PCR method was employed to detect biofilm genes and showed that 49 (87.5%), 26 (46.4%), and 30 (53.6%) of isolates carried fimH, mrkA, and mrkD, respectively. Furthermore, susceptibility tests for different antibiotics revealed that K. pneumoniae isolates were resistant to amoxicillin-clavulanic acid (n=11, 19.5%), ceftazidime (n=13, 22.4%), ofloxacin (n=16, 28.1%), and tobramycin (n=27, 48.4%). It was also found all K. pneumonia isolates were sensitive to polymyxin B (92.6%), imipenem (88.3%), meropenem (79.4%), and amikacin (60.5%).}, }
@article {pmid36882931, year = {2023}, author = {Magagula, S and Petzer, IM and Famuyide, IM and Karzis, J}, title = {Biofilm expression and antimicrobial resistance patterns of Streptococcus uberis isolated from milk samples of dairy cows in South Africa.}, journal = {The Journal of dairy research}, volume = {}, number = {}, pages = {1-5}, doi = {10.1017/S0022029923000158}, pmid = {36882931}, issn = {1469-7629}, abstract = {The research described in this Research Communication addresses the hypothesis that intramammary infections with Streptococcus uberis (S. uberis) are associated with biofilm formation, which limits antibiotic efficacy. This retrospective study investigated biofilm expression and antimicrobial resistance (AMR) patterns of 172 S. uberis infections. Isolates were recovered from milk samples of subclinical, clinical, and intramammary infection cases on 30 commercial dairy herds. We determined the presence and intensity of biofilm expression of S. uberis isolates in vitro in three somatic cell count categories to recognise their AMR patterns. An automated minimum inhibitory concentration system with a commercially available panel of 23 antimicrobial agents evaluated AMR, while biofilm determination was conducted using a microplate method. The study established that all the S. uberis isolates assessed expressed biofilm with the following varying degrees of intensities: 30 (17.8%) strong, 59 (34.9%) medium and 80 (47.3%) weak biofilms. The newly registered UBAC mastitis vaccine containing biofilm adhesion components may, therefore, be a viable option for proactive mastitis management under field conditions. No differences were identified between biofilm intensity and the three somatic cell count groups. Most S. uberis isolates indicated a high-level sensitivity to the antimicrobial agents tested. Resistances were present in 8.7, 8.1 and 7.0% cases to rifampin, minocycline and tetracycline, respectively. Multidrug resistance was observed in 6.4%, emphasising AMR to antibiotics used in human medicine only. The low overall resistance suggests that farmers adhere to the prudent use of antimicrobials in the dairy industry.}, }
@article {pmid36881023, year = {2023}, author = {Contreas, L and Hook, AL and Winkler, DA and Figueredo, G and Williams, P and Laughton, CA and Alexander, MR and Williams, PM}, title = {Linear Binary Classifier to Predict Bacterial Biofilm Formation on Polyacrylates.}, journal = {ACS applied materials &amp; interfaces}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsami.2c23182}, pmid = {36881023}, issn = {1944-8252}, abstract = {Bacterial infections are increasingly problematic due to the rise of antimicrobial resistance. Consequently, the rational design of materials naturally resistant to biofilm formation is an important strategy for preventing medical device-associated infections. Machine learning (ML) is a powerful method to find useful patterns in complex data from a wide range of fields. Recent reports showed how ML can reveal strong relationships between bacterial adhesion and the physicochemical properties of polyacrylate libraries. These studies used robust and predictive nonlinear regression methods that had better quantitative prediction power than linear models. However, as nonlinear models' feature importance is a local rather than global property, these models were hard to interpret and provided limited insight into the molecular details of material-bacteria interactions. Here, we show that the use of interpretable mass spectral molecular ions and chemoinformatic descriptors and a linear binary classification model of attachment of three common nosocomial pathogens to a library of polyacrylates can provide improved guidance for the design of more effective pathogen-resistant coatings. Relevant features from each model were analyzed and correlated with easily interpretable chemoinformatic descriptors to derive a small set of rules that give model features tangible meaning that elucidate relationships between the structure and function. The results show that the attachment of Pseudomonas aeruginosa and Staphylococcus aureus can be robustly predicted by chemoinformatic descriptors, suggesting that the obtained models can predict the attachment response to polyacrylates to identify anti-attachment materials to synthesize and test in the future.}, }
@article {pmid36879323, year = {2023}, author = {Ghezzi, D and Boi, M and Sassoni, E and Valle, F and Giusto, E and Boanini, E and Baldini, N and Cappelletti, M and Graziani, G}, title = {Customized biofilm device for antibiofilm and antibacterial screening of newly developed nanostructured silver and zinc coatings.}, journal = {Journal of biological engineering}, volume = {17}, number = {1}, pages = {18}, pmid = {36879323}, issn = {1754-1611}, abstract = {BACKGROUND: Bacterial colonisation on implantable device surfaces is estimated to cause more than half of healthcare-associated infections. The application of inorganic coatings onto implantable devices limits/prevents microbial contaminations. However, reliable and high-throughput deposition technologies and experimental trials of metal coatings for biomedical applications are missing. Here, we propose the combination of the Ionized Jet Deposition (IJD) technology for metal-coating application, with the Calgary Biofilm Device (CBD) for high-throughput antibacterial and antibiofilm screening, to develop and screen novel metal-based coatings.<br><br>RESULTS: The films are composed of nanosized spherical aggregates of metallic silver or zinc oxide with a homogeneous and highly rough surface topography. The antibacterial&#xa0;and&#xa0;antibiofilm activity of the coatings is related with the Gram staining, being Ag and Zn coatings more effective against gram-negative and gram-positive bacteria, respectively. The antibacterial/antibiofilm effect is proportional to the amount of metal deposited that influences the amount of metal ions released. The roughness also impacts the activity, mostly for Zn coatings. Antibiofilm properties are stronger on biofilms developing on the coating than on biofilms formed on uncoated substrates. This suggests a higher antibiofilm effect arising from the direct contact bacteria-coating than that associated with the metal ions release. Proof-of-concept of application to titanium alloys, representative of orthopaedic prostheses, confirmed the antibiofilm results, validating the approach. In addition, MTT tests show that the coatings are non-cytotoxic and ICP demonstrates that they have suitable release duration (>&#x2009;7&#xa0;days), suggesting the applicability of these new generation metal-based coatings for the functionalization of biomedical devices.<br><br>CONCLUSIONS: The combination of the Calgary Biofilm Device with the Ionized Jet Deposition technology proved to be an innovative and powerful tool that allows to monitor both the metal ions release and the surface topography of the films, which makes it suitable for the study of the antibacterial and antibiofilm activity of nanostructured materials. The results obtained with&#xa0;the CBD were validated with coatings on titanium alloys and extended by also considering the anti-adhesion properties and biocompatibility. In view of upcoming application in orthopaedics, these evaluations would be useful for the development of materials with pleiotropic antimicrobial mechanisms.}, }
@article {pmid36878870, year = {2023}, author = {Qiu, X and Han, X and Zhang, X and Teng, LA and Sriwastva, MK and Zhen, L and Li, Z and Liu, M and Ren, Y and Wang, S}, title = {Lactobacillus rhamnosus GG alleviates colitis caused by chemotherapy via biofilm formation.}, journal = {Journal of gastroenterology and hepatology}, volume = {}, number = {}, pages = {}, doi = {10.1111/jgh.16164}, pmid = {36878870}, issn = {1440-1746}, abstract = {BACKGROUND: Severe colitis is a common side effect of chemotherapy in cancer patients. In this study, we attempted to enhance the viability of probiotics in a gastric acid environment and improve the colitis induced by dextran sulfate sodium (DSS) and docetaxel.<br><br>METHODS: We purified Lactobacillus from yogurt and estimated their growth at pH 6.8 and pH 2.0. In the further investigation, the bacterial biofilm formation was used to define the mechanism by which administration of Lactobacillus rhamnosus (LGG) via oral gavage alleviates the colitis and intestine permeability of the mice induced by DSS and docetaxel. The potential benefit of probiotics on the treatment of breast cancer metastasis has been assessed as well.<br><br>RESULTS: Lactobacillus from yogurt growth was unexpectedly faster in the pH 2.0 than in the neutral pH medium during the first hour. LGG administered in the fasting state via oral gavage significantly improved the preventive effect in the colitis caused by DSS and docetaxel. LGG reduced the permeability of the intestine and decreased the expression of proinflammatory cytokines, TNF&#x3b1;, IL-1&#x3b2;, and IL-6, in colitis by biofilm formation. Increasing the docetaxel dose may reduce breast tumor growth and metastasis in the lung but did not benefit survival due to severe colitis. However, the LGG supplement significantly improved the survival of tumor-bearing mice following a high dose of docetaxel treatment.<br><br>CONCLUSIONS: Our findings provide new insights into the potential mechanism of probiotic protection of the intestine and provide a novel therapeutic strategy to augment the chemotherapeutic treatment of tumors.}, }
@article {pmid36879587, year = {2019}, author = {Rastegar Khosravi, M and Khonsha, M and Ramazanzadeh, R}, title = {Combined Effect of Levofloxacin and N-Acetylcysteine against Enterococcus faecalis Biofilm for Regenerative Endodontics: An in Vitro Study.}, journal = {Iranian endodontic journal}, volume = {14}, number = {1}, pages = {40-46}, pmid = {36879587}, issn = {2008-2746}, abstract = {INTRODUCTION: Endodontic treatment of necrotic immature teeth poses several clinical challenges. A major problem is the elimination of microorganisms from the root canal system. This study evaluates the in vitro antibacterial efficacy of ciprofloxacin (CIP), levofloxacin (LEV), and their combination with N-acetylcysteine (NAC) in root canals infected with Enterococcus faecalis (E. faecalis).<br><br>METHODS AND MATERIALS: A total of 120 human extracted teeth with single canals were prepared and randomly divided into six groups: Calcium hydroxide (CH), ciprofloxacin (CIP), levofloxacin (LEV), ciprofloxacin and N-acetylcysteine (CIP+NAC), levofloxacin and N-acetylcysteine (LEV+NAC), and normal saline as a positive control. According to the name of the groups, intracanal medicaments were placed into the canals and the teeth were restored with a temporary filling. After one week, intracanal medicament was removed and the final count of bacteria was measured. Antibacterial effect of medicament was assessed by measuring the percentage reduction in the colony counts (RCC) and scanning electron microscopy (SEM). The Mann-Whitney U test and the Kruskal-Wallis test were used to compare the overall antibacterial efficacy of the intracanal medicaments at significance level of 0.05.<br><br>RESULTS: All intracanal medicaments were significantly more effective than calcium hydroxide (P<0.05). The combination of LEV and NAC caused significantly higher reduction in colony count in comparison with other tested medicaments (P=0.001).<br><br>CONCLUSION: The combination of LEV and NAC showed greater antibacterial activity compared with other tested medicaments against biofilm of E. faecalis. Thus, it has the potential to be used in regenerative endodontic treatments.}, }
@article {pmid36883019, year = {2018}, author = {Ghahramani, Y and Yaghoobi, F and Motamedi, R and Jamshidzadeh, A and Abbaszadegan, A}, title = {Effect of Endodontic Irrigants and Medicaments Mixed with Silver Nanoparticles against Biofilm Formation of Enterococcus faecalis.}, journal = {Iranian endodontic journal}, volume = {13}, number = {4}, pages = {559-564}, pmid = {36883019}, issn = {2008-2746}, abstract = {INTRODUCTION: The aim of this study was to evaluate the effectiveness of chlorhexidine (CHX), sodium hypochlorite (NaOCl), calcium hydroxide (CH) and double antibiotic paste (DAP) mixed with silver nanoparticles (AgNPs) against Enterococcus faecalis .<br><br>METHODS AND MATERIALS: Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and biofilm formation inhibition (after 72 h) of the experimental substances alone or mixed with AgNPs were measured against E. faecalis using microtiter plate method. Bacterial cultures turbidity was measured using a spectrophotometer. All procedures were performed in triplicates.<br><br>RESULTS: The MIC values for CHX, NaOCl, CH and DAP were equal to 0.012, 1.25, 1.6 and 0.156 mg/mL, and their MBC's were 0.025, 2.5, 0 and 0.625 mg/mL. After mixing them with AgNPs, the MIC's for CHX, NaOCl, CH and DAP were reduced to 0.0032, 0.158, 0.2 and 0.0391 mg/mL, while their MBC's were reduced to 0.0064, 0.0632, 0.401 and 0.0156 mg/mL. Biofilm formation inhibition occurred in higher dilutions of all irrigants and medicaments as they were mixed with Ag NPs.<br><br>CONCLUSIONS: Adding AgNPs resulted in an increased antimicrobial activity at the tested dilutions for all experimental substances. More investigations in in vivo conditions are required to confirm the results of this study.}, }
@article {pmid36878335, year = {2023}, author = {Al-Saafin, BA and Al-Bakri, AG and Abdelrazig, S and Dahabiyeh, LA}, title = {Investigating the effect of the probiotic Lactobacillus plantarum and the prebiotic fructooligosaccharides on Pseudomonas aeruginosa metabolome, virulence factors and biofilm formation as potential quorum sensing inhibitors.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106057}, doi = {10.1016/j.micpath.2023.106057}, pmid = {36878335}, issn = {1096-1208}, abstract = {Pseudomonas aeruginosa (P. aeruginosa) uses quorum sensing signaling (QS) molecules to control the expression of virulence factors and biofilm formation. In this study, the effects of the probiotic's (Lactobacillus plantarum (L. plantarum)) lysate and cell-free supernatant and the prebiotic (Fructooligosaccharides (FOS)) on the levels of P. aeruginosa QS molecules, virulence factors, biofilm density and metabolites were observed. These effects were investigated using exofactor assays, crystal violet and liquid chromatography-mass spectrometry (LC-MS)-based metabolomics approach. Results showed that in comparison to untreated P. aeruginosa, the L. plantarum cell-free supernatant (5%) and FOS (2%) significantly reduced the levels of the virulence factor pyoverdine (PVD) and several metabolites in the QS pathway including Pseudomonas autoinducer-2 (PAI-2). Metabolomics study revealed that the level of different secondary metabolites involved in the biosynthesis of vitamins, amino acids and the tricarboxylic acid (TCA) cycle were also affected. L. Plantarum was found to have a higher impact on the metabolomics profile of P. aeruginosa and its QS molecules compared to FOS. Lastly, a decrease in the formation of the P. aeruginosa biofilm was observed in a time-dependent pattern upon treatment with either cell-free supernatant of L. plantarum (5%), FOS (2%) or a combination of both treatments (5% + 2%). The latter showed the highest effect with 83% reduction in biofilm density at 72 h incubation. This work highlighted the important role probiotics and prebiotics play as potential QS inhibitors for P. aeruginosa. Moreover, it demonstrated the significant role of LC-MS metabolomics for investigating the altered biochemical and QS pathways in P. aeruginosa.}, }
@article {pmid36878334, year = {2023}, author = {Lau, TV and Puah, SM and Tan, JMA and Merino, S and Puthucheary, SD and Chua, KH}, title = {Flagellar motility mediates biofilm formation in Aeromonas dhakensis.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106059}, doi = {10.1016/j.micpath.2023.106059}, pmid = {36878334}, issn = {1096-1208}, abstract = {Aeromonas dhakensis possesses dual flagellar systems for motility under different environments. Flagella-mediated motility is necessary for biofilm formation through an initial attachment of bacteria to the surface, but this has not been elucidated in A. dhakensis. This study investigates the role of polar (flaH, maf1) and lateral (lafB, lafK and lafS) flagellar genes in the biofilm formation of a clinical A. dhakensis strain WT187 isolated from burn wound infection. Five deletion mutants and corresponding complemented strains were constructed using pDM4 and pBAD33 vectors, respectively, and analyzed for motility and biofilm formation using crystal violet staining and real-time impedance-based assays. All mutants were significantly reduced in swimming (p < 0.0001), swarming (p < 0.0001) and biofilm formation using crystal violet assay (p < 0.05). Real-time impedance-based analysis revealed WT187 biofilm was formed between 6-21 h, consisting of early (6-10 h), middle (11-18 h), and late (19-21 h) stages. The highest cell index of 0.0746 was recorded at 22-23 h and biofilms began to disperse starting from 24 h. Mutants Δmaf1, ΔlafB, ΔlafK and ΔlafS exhibited reduced cell index values at 6-48 h when compared to WT187 which indicates less biofilm formation. Two complemented strains cmaf1 and clafB exhibited full restoration to wild-type level in swimming, swarming, and biofilm formation using crystal violet assay, hence suggesting that both maf1 and lafB genes are involved in biofilm formation through flagella-mediated motility and surface attachment. Our study shows the role of flagella in A. dhakensis biofilm formation warrants further investigations.}, }
@article {pmid36877588, year = {2023}, author = {Ding, Y and Ma, R and Liu, G and Li, X and Xu, K and Liu, P and Cai, K}, title = {Fabrication of a New Hyaluronic Acid/Gelatin Nanocomposite Hydrogel Coating on Titanium-Based Implants for Treating Biofilm Infection and Excessive Inflammatory Response.}, journal = {ACS applied materials &amp; interfaces}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsami.2c23320}, pmid = {36877588}, issn = {1944-8252}, abstract = {Persistent inflammation caused by implant-associated biofilm infections has emerged as a significant clinical issue. While many methods have been developed to give implants great anti-biofilm benefits, the post-inflammatory microenvironment is frequently disregarded. Oxidative stress (OS) due to excessive reactive oxygen species (ROS) is considered to be one of the specific physiological signals of the inflammation microenvironment. Herein, ZIF-90-Bi-CeO2 nanoparticles (NPs) were incorporated into a Schiff-base chemically crosslinked hydrogel composed of aldehyde-based hyaluronic acid and gelatin. Through chemical crosslinking between polydopamine and gelatin, the hydrogel coating adhered to the Ti substrate. The modified Ti substrate gained multimodal antibacterial and anti-biofilm functions, which were attributed to the photothermal effect of Bi NPs, and the release of Zn ions and CeO2 NPs. Notably, CeO2 NPs endowed the system with dual-enzyme (SOD- and CAT-like) catalytic activities. In a rat implant-associated infection (IAI) model, the dual-functional hydrogel had a biofilm-removal ability and regulated OS and inflammatory responses to facilitate osseointegration. The photothermal therapy combined with a host inflammation-microenvironment regulation strategy might provide a novel treatment for biofilm infection and the accompanying excessive inflammation.}, }
@article {pmid36877407, year = {2023}, author = {Han, J and Luo, J and Du, Z and Chen, Y and Liu, T}, title = {Synergistic Effects of Baicalin and Levofloxacin Against Hypervirulent Klebsiella pneumoniae Biofilm In Vitro.}, journal = {Current microbiology}, volume = {80}, number = {4}, pages = {126}, pmid = {36877407}, issn = {1432-0991}, abstract = {Hypervirulent Klebsiella pneumoniae (hvKp) strains that form biofilms have recently emerged worldwide; however, the mechanisms underlying biofilm formation and disruption remain elusive. In this study, we established a hvKp biofilm model, investigated its in vitro formation pattern, and determined the mechanism of biofilm destruction by baicalin (BA) and levofloxacin (LEV). Our results revealed that hvKp exhibited a strong biofilm-forming ability, forming early and mature biofilms after 3 and 5 d, respectively. Early biofilm and bacterial burden were significantly reduced by BA + LEV and EM + LEV treatments, which destroyed the 3D structure of early biofilms. Conversely, these treatments were less effective against mature biofilm. The expression of both AcrA and wbbM was significantly downregulated in the BA + LEV group. These findings indicated that BA + LEV might inhibit the formation of hvKp biofilm by altering the expression of genes regulating efflux pumps and lipopolysaccharide biosynthesis.}, }
@article {pmid36875729, year = {2023}, author = {Haroon, U and Munis, MFH and Liaquat, F and Khizar, M and Elahi, M and Chaudhary, HJ}, title = {Biofilm formation and flocculation potential analysis of halotolerant Bacillus tequilensis and its inoculation in soil to mitigate salinity stress of chickpea.}, journal = {Physiology and molecular biology of plants : an international journal of functional plant biology}, volume = {29}, number = {2}, pages = {277-288}, pmid = {36875729}, issn = {0971-5894}, abstract = {UNLABELLED: Application of beneficial microbes in soil is an important avenue to control plant stresses. In this study, the salinity tolerance of halotolerant bacteria (Bacillus tequilensis) was investigated and the bacterium was inoculated in the soil to mitigate salinity stress. The results revealed the highest floc yield and biofilm formation ability of B. tequilensis at 100 mM NaCl concentration. Fourier transformed infrared spectroscopy depicted the presence of carbohydrates and proteins which binds with sodium ions (Na[+]) and provide tolerance against salinity. Using PCR, plant growth-promoting bacterial genes viz., 1-aminocyclopropane-1-carboxylate deaminase and pyrroloquinoline quinone were successfully amplified from the genome of B. tequilensis. In the saline soil, B. tequilensis was inoculated and chickpea plants were grown. The bacterial strain improved the physiology, biochemistry, and antioxidant enzyme activities of the chickpea plant under salt stress. Plants inoculated with B. tequilensis exhibited higher relative water content, higher photosynthetic pigments, lower levels of hydrogen peroxide (H2O2) and malondialdehyde, and improved enzymatic activity for the scavenging of reactive oxygen species. The findings of this study suggest the sustainable use of B. tequilensis to mitigate the salinity stress of chickpea and other crops. This bacterium not only helps in the alleviation of the toxic effects of salt but also increases plant growth along with a reduction in crop losses due to salinity.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-023-01280-1.}, }
@article {pmid36875516, year = {2023}, author = {Wells, M and Schneider, R and Bhattarai, B and Currie, H and Chavez, B and Christopher, G and Rumbaugh, K and Gordon, V}, title = {Perspective: The viscoelastic properties of biofilm infections and mechanical interactions with phagocytic immune cells.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1102199}, pmid = {36875516}, issn = {2235-2988}, abstract = {Biofilms are viscoelastic materials that are a prominent public health problem and a cause of most chronic bacterial infections, in large part due to their resistance to clearance by the immune system. Viscoelastic materials combine both solid-like and fluid-like mechanics, and the viscoelastic properties of biofilms are an emergent property of the intercellular cohesion characterizing the biofilm state (planktonic bacteria do not have an equivalent property). However, how the mechanical properties of biofilms are related to the recalcitrant disease that they cause, specifically to their resistance to phagocytic clearance by the immune system, remains almost entirely unstudied. We believe this is an important gap that is ripe for a large range of investigations. Here we present an overview of what is known about biofilm infections and their interactions with the immune system, biofilm mechanics and their potential relationship with phagocytosis, and we give an illustrative example of one important biofilm-pathogen (Pseudomonas aeruginosa) which is the most-studied in this context. We hope to inspire investment and growth in this relatively-untapped field of research, which has the potential to reveal mechanical properties of biofilms as targets for therapeutics meant to enhance the efficacy of the immune system.}, }
@article {pmid36873470, year = {2023}, author = {Rezende Mires de Carvalho, R and Silva Dias, C and Nogueira Paz, L and Melo de Lima Fires, T and Pereira Figueira, C and Araújo Damasceno, K and Hanzen Pinna, M}, title = {Biofilm formation in vitro by Leptospira interrogans strains isolated from naturally infected dogs and their role in antimicrobial resistance.}, journal = {Heliyon}, volume = {9}, number = {3}, pages = {e13802}, pmid = {36873470}, issn = {2405-8440}, abstract = {Leptospira interrogans is a biofilm-forming pathogen, however, there are few data involving Brazilian strains isolated from dogs and their antimicrobial sensitivity in planktonic and biofilm forms. The potential for biofilm formation and antimicrobial resistance in naturally infected dogs is a fundamental approach towards disease epidemiology and the establishment of consistent prophylaxis and control measures. The objective of this study was to evaluate in vitro biofilm formation of a reference strain (L. interrogans, sv. Copenhageni L1 130 - L20) and of L. interrogans isolated from dogs (C20, C29, C51, C82), with subsequent evaluation of antimicrobial susceptibility in planktonic and biofilm forms. The semi quantification of biofilm production revealed a dynamic process of development over time, with mature biofilm formation early on the seventh day of incubation. All strains were efficient for in vitro biofilm formation and, in this form, they were considerably more resistant compared to their planktonic form, with MIC90 of 1600 μg/mL for amoxicillin, 800 μg/mL for ampicillin, and >1600 μg/mL for doxycycline and ciprofloxacin. The strains studies were isolated on naturally infected dogs that might act as reservoirs and sentinels for human infections. The potential to antimicrobial resistance together with the close relation between dogs and humans indicates the need for greater actions on disease control and surveillance. Moreover, biofilm formation may contribute to the persistence of Leptospira interrogans in the host and these animals can act as chronic carriers, disseminating the agent in the environment.}, }
@article {pmid36870235, year = {2023}, author = {Yang, H and Zhan, X and Song, L and Cheng, S and Su, R and Zhang, Y and Guo, D and Lü, X and Xia, X and Shi, C}, title = {Synergistic antibacterial and anti-biofilm mechanisms of ultrasound combined with citral nanoemulsion against Staphylococcus aureus 29213.}, journal = {International journal of food microbiology}, volume = {391-393}, number = {}, pages = {110150}, doi = {10.1016/j.ijfoodmicro.2023.110150}, pmid = {36870235}, issn = {1879-3460}, abstract = {This study investigated the antibacterial and antibiofilm mechanism of ultrasound (US) combined with citral nanoemulsion (CLNE) against Staphylococcus aureus and mature biofilm. Combined treatments resulted in greater reductions in bacterial numbers compared to ultrasound or CLNE treatments alone. Confocal laser scanning microscopy (CLSM), flow cytometry (FCM), protein nucleic acid leakage, and N-phenyl-l-naphthylamine (NPN) uptake analysis showed that the combined treatment disrupted cell membrane integrity and permeability. Reactive oxygen species (ROS) and malondialdehyde (MDA) assays indicated that US+CLNE exacerbated cellular oxidative stress and membrane lipid peroxidation. Field emission scanning electron microscopy (FESEM) revealed that the synergistic processing of ultrasound and CLNE resulted in cell rupture and collapse. In addition, US+CLNE showed a more pronounced removal effect than both alone in the biofilm on the stainless steel sheet. US+CLNE reduced biomass, the number of viable cells in the biofilm, cell viability and EPS polysaccharide contents. The results of CLSM also showed that US+CLNE disrupted the structure of the biofilm. This research elucidates the synergistic antibacterial and anti-biofilm mechanism of ultrasound combined citral nanoemulsion, which provides a safe and efficient sterilization method for the food industry.}, }
@article {pmid36870201, year = {2023}, author = {Verma, NK and Dewangan, RP and Harioudh, MK and Ghosh, JK}, title = {Introduction of a β-leucine residue instead of leucine[9] and glycine[10] residues in Temporin L for improved cell selectivity, stability and activity against planktonic and biofilm of methicillin resistant S. aureus.}, journal = {Bioorganic chemistry}, volume = {134}, number = {}, pages = {106440}, doi = {10.1016/j.bioorg.2023.106440}, pmid = {36870201}, issn = {1090-2120}, abstract = {Leucine and glycine residues, at the 9th and 10th positions of helical domain of naturally occurring antimicrobial peptide (AMP), Temporin L were substituted with an unnatural amino acid, β-leucine (homovaline) to improve its serum protease stability, haemolytic/cytotoxic properties and reduce the size to some extent. The designed analogue, L9βl-TL showed either equal or improved antimicrobial activity to TL against different microorganisms including the resistant strains. Interestingly, L9βl-TL also exhibited lower haemolytic and cytotoxic activities against human red blood cells and 3T3 cells, respectively. Moreover, L9βl-TL showed antibacterial activity in presence of 25% (v/v) human serum and showed resistance against proteolytic cleavage in presence of it that suggested the serum protease stability of the TL-analogue. L9βl-TL exhibited un-ordered secondary structures in both bacterial and mammalian membrane mimetic lipid vesicles as compared to the helical structures of TL in these environments. However, tryptophan fluorescence studies demonstrated more selective interaction of L9βl-TL with bacterial membrane mimetic lipid vesicles in comparison to non-selective interactions of TL with both kinds of lipid vesicles. Membrane depolarization studies with live MRSA and bacterial membrane-mimetic lipid vesicles suggested a membrane-disrupting mode of action of L9βl-TL. L9βl-TL showed faster bactericidal mechanism compared to TL against MRSA. Interestingly, L9βl-TL was found as more potent than TL either in inhibiting biofilm formation or in eradicating the mature biofilm formed by MRSA. Overall, the present work demonstrates a simple and useful strategy to design of an analogue of TL, with minimal modifications while maintaining its antimicrobial activity with lesser toxicity and higher stability which could be attempted for other AMPs as well.}, }
@article {pmid36869686, year = {2023}, author = {Ramezani, M and Monroe, MBB}, title = {Bacterial protease-responsive shape memory polymers for infection surveillance and biofilm inhibition in chronic wounds.}, journal = {Journal of biomedical materials research. Part A}, volume = {}, number = {}, pages = {}, doi = {10.1002/jbm.a.37527}, pmid = {36869686}, issn = {1552-4965}, abstract = {Chronic wound healing is often negatively impacted by infection. Efficient infection assessment is crucial for effective treatment, and biofilm inhibition could improve treatment efficacy. To that end, we developed a bacterial protease-responsive shape memory polymer based on a segmented polyurethane with incorporated poly(glutamic acid) peptide (PU-Pep). Poly(glutamic acid) degrades in response to bacterial proteases to trigger shape recovery of PU-Pep films that are programmed into a secondary shape. These materials have transition temperatures well above body temperature (~60°C), which enables stable storage in temporary shapes after implantation. Synthesized polymers have high shape fixity (~74%-88%), shape recovery (~93%-95%), and cytocompatibility (~100%). Strained PU-Pep samples underwent shape recovery within ≤24 h in response to the V8 enzyme from Staphylococcus aureus (S. aureus, ~50% recovery) and multiple bacteria strains (S. aureus [~40%], Staphylococcus epidermidis [~30%], and Escherichia coli [~25%]), and they had minimal shape change in response to media controls and mammalian cells. Shape recovery of strained PU-Pep samples prevented biofilm formation on the sample surfaces, and resulting attached planktonic bacteria were vulnerable to applied treatments. PU-Pep with physically incorporated antimicrobials simultaneously prevented biofilm formation and killed isolated bacteria. PU-Pep dressings displayed visible shape change and resistance to biofilm formation in in vitro and ex vivo models. In the in vitro model, PU-Pep shape change also disrupted pre-formed biofilm structures. This novel bacterial protease-responsive biomaterial could serve as a wound dressing that changes shape specifically during bacterial colonization to alert clinicians to infection and make biofilm-associated infections easier to treat.}, }
@article {pmid36869500, year = {2023}, author = {Lake, FB and van Overbeek, LS and Baars, JJP and Abee, T and den Besten, HMW}, title = {Variability in growth and biofilm formation of Listeria monocytogenes in Agaricus bisporus mushroom products.}, journal = {Food research international (Ottawa, Ont.)}, volume = {165}, number = {}, pages = {112488}, doi = {10.1016/j.foodres.2023.112488}, pmid = {36869500}, issn = {1873-7145}, abstract = {Foods and food production environments can be contaminated with Listeria monocytogenes and may support growth of this foodborne pathogen. This study aims to characterize the growth and biofilm formation of sixteen L. monocytogenes strains, isolated from mushroom production and processing environments, in filter-sterilized mushroom medium. Strain performance was compared to twelve L. monocytogenes strains isolated from other sources including food and human isolates. All twenty-eight L. monocytogenes strains showed rather similar growth performance at 20 °C in mushroom medium, and also significant biofilm formation was observed for all strains. HPLC analysis revealed the presence of mannitol, trehalose, glucose, fructose and glycerol, that were all metabolized by L. monocytogenes, except mannitol, in line with the inability of L. monocytogenes to metabolize this carbohydrate. Additionally, the growing behavior of L. monocytogenes was tested on whole, sliced and smashed mushroom products to quantify performance in the presence of product-associated microbiota. A significant increase of L. monocytogenes was observed with higher increase of counts when the mushroom products were more damaged, even with the presence of high background microbiota counts. This study demonstrated that L. monocytogenes grows well in mushroom products, even when the background microbiota is high, highlighting the importance to control (re)contamination of mushrooms.}, }
@article {pmid36867905, year = {2023}, author = {Deng, Y and Yang, G and Lens, PNL and He, Y and Qie, L and Shen, X and Chen, J and Cheng, Z and Chen, D}, title = {Enhanced removal of mixed VOCs with different hydrophobicities by Tween 20 in a biotrickling filter: Kinetic analysis and biofilm characteristics.}, journal = {Journal of hazardous materials}, volume = {450}, number = {}, pages = {131063}, doi = {10.1016/j.jhazmat.2023.131063}, pmid = {36867905}, issn = {1873-3336}, abstract = {Mass transfer limitation usually causes the poor performance of biotrickling filters (BTFs) for the treatment of hydrophobic volatile organic compounds (VOCs) during long-term operation. In this study, two identical lab-scale BTFs were established to remove a mixture of n-hexane and dichloromethane (DCM) gases using non-ionic surfactant Tween 20 by Pseudomonas mendocina NX-1 and Methylobacterium rhodesianum H13. A low pressure drop (≤110 Pa) and a rapid biomass accumulation (17.1 mg g[-1]) were observed in the presence of Tween 20 during the startup period (30 d). The removal efficiency (RE) of n-hexane was enhanced by 15.0%- 20.5% while DCM was completely removed with the inlet concentration (IC) of 300 mg·m[-3] at different empty bed residence times in the Tween 20 added BTF. The viable cells and the relative hydrophobicity of the biofilm were increased under the action of Tween 20, which facilitated the mass transfer and enhanced the metabolic utilization of pollutants by microbes. Besides, Tween 20 addition enhanced the biofilm formation processes including the increased extracellular polymeric substance (EPS) secretion, biofilm roughness and biofilm adhesion. The kinetic model simulated the removal performance of the BTF with Tween 20 for the mixed hydrophobic VOCs, and the goodness-of-fit was above 0.9.}, }
@article {pmid36865097, year = {2023}, author = {Arbour, CA and Nagar, R and Bernstein, HM and Ghosh, S and Al-Sammarraie, Y and Dorfmueller, HC and Ferguson, MAJ and Stanley-Wall, NR and Imperiali, B}, title = {Defining Early Steps in B. subtilis Biofilm Biosynthesis.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.02.22.529487}, pmid = {36865097}, abstract = {UNLABELLED: The Bacillus subtilis extracellular biofilm matrix includes an exopolysaccharide that is critical for the architecture and function of the community. To date, our understanding of the biosynthetic machinery and the molecular composition of the exopolysaccharide of B. subtilis remains unclear and incomplete. This report presents synergistic biochemical and genetic studies built from a foundation of comparative sequence analyses targeted at elucidating the activities of the first two membrane-committed steps in the exopolysaccharide biosynthetic pathway. By taking this approach, we determined the nucleotide sugar donor and lipid-linked acceptor substrates for the first two enzymes in the B. subtilis biofilm exopolysaccharide biosynthetic pathway. EpsL catalyzes the first phosphoglycosyl transferase step using UDP-di- N -acetyl bacillosamine as phospho-sugar donor. EpsD is a GT-B fold glycosyl transferase that facilitates the second step in the pathway that utilizes the product of EpsL as an acceptor substrate and UDP- N -acetyl glucosamine as the sugar donor. Thus, the study defines the first two monosaccharides at the reducing end of the growing exopolysaccharide unit. In doing so we provide the first evidence of the presence of bacillosamine in an exopolysaccharide synthesized by a Gram-positive bacterium.<br><br>IMPORTANCE: Biofilms are the communal way of life that microbes adopt to increase survival. Key to our ability to systematically promote or ablate biofilm formation is a detailed understanding of the biofilm matrix macromolecules. Here we identify the first two essential steps in the Bacillus subtilis biofilm matrix exopolysaccharide synthesis pathway. Together our studies and approaches provide the foundation for the sequential characterization of the steps in exopolysaccharide biosynthesis, using prior steps to enable chemoenzymatic synthesis of the undecaprenol diphosphate-linked glycan substrates.}, }
@article {pmid36864390, year = {2023}, author = {Asadi, S and Nayeri-Fasaei, B and Zahraei-Salehi, T and Yahya-Rayat, R and Shams, N and Sharifi, A}, title = {Antibacterial and anti-biofilm properties of carvacrol alone and in combination with cefixime against Escherichia coli.}, journal = {BMC microbiology}, volume = {23}, number = {1}, pages = {55}, pmid = {36864390}, issn = {1471-2180}, abstract = {BACKGROUND: Plant-derived compounds can be used as antimicrobial agents in medicines and as food preservatives. These compounds can be applied along with other antimicrobial agents to strengthen the effect and/or reduce the required treatment dose.<br><br>RESULTS: In the present study, the antibacterial, anti-biofilm and quorum sensing inhibitory activity of carvacrol alone and in combination with the antibiotic cefixime against Escherichia coli was investigated. The MIC and MBC values for carvacrol were 250&#xa0;&#x3bc;g/mL. In the checkerboard test, carvacrol showed a synergistic interaction with cefixime against E. coli (FIC index&#x2009;=&#x2009;0.5). Carvacrol and cefixime significantly inhibited biofilm formation at MIC/2 (125 and 62.5&#xa0;&#x3bc;g/mL), MIC/4 (62.5 and 31.25&#xa0;&#x3bc;g/mL) and MIC/8 (31.25 and 15.625&#xa0;&#x3bc;g/mL) for carvacrol and cefixime, respectively. The antibacterial and anti-biofilm potential effect of carvacrol confirmed by the scanning electron microscopy. Real-time quantitative reverse transcription PCR revealed significant down-regulation of the luxS and pfs genes following treatment with a MIC/2 (125&#xa0;&#x3bc;g/mL) concentration of carvacrol alone and of only pfs gene following treatment with MIC/2 of carvacrol in combination with MIC/2 of cefixime (p&#x2009;<&#x2009;0.05).<br><br>CONCLUSIONS: Because of the significant antibacterial and anti-biofilm activity of carvacrol, the present study examines this agent as an antibacterial drug of natural origin. The results indicate that in this study the best antibacterial and anti-biofilm properties are for the combined use of cefixime and carvacrol.}, }
@article {pmid36864092, year = {2023}, author = {Frenkel, A and Zecharia, E and Gómez-Pérez, D and Sendersky, E and Yegorov, Y and Jacob, A and Benichou, JIC and Stierhof, YD and Parnasa, R and Golden, SS and Kemen, E and Schwarz, R}, title = {Cell specialization in cyanobacterial biofilm development revealed by expression of a cell-surface and extracellular matrix protein.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {10}, pmid = {36864092}, issn = {2055-5008}, abstract = {Cyanobacterial biofilms are ubiquitous and play important roles in diverse environments, yet, understanding of the processes underlying the development of these aggregates is just emerging. Here we report cell specialization in formation of Synechococcus elongatus PCC 7942 biofilms-a hitherto unknown characteristic of cyanobacterial social behavior. We show that only a quarter of the cell population expresses at high levels the four-gene ebfG-operon that is required for biofilm formation. Almost all cells, however, are assembled in the biofilm. Detailed characterization of EbfG4 encoded by this operon revealed cell-surface localization as well as its presence in the biofilm matrix. Moreover, EbfG1-3 were shown to form amyloid structures such as fibrils and are thus likely to contribute to the matrix structure. These data suggest a beneficial 'division of labor' during biofilm formation where only some of the cells allocate resources to produce matrix proteins-'public goods' that support robust biofilm development by the majority of the cells. In addition, previous studies revealed the operation of a self-suppression mechanism that depends on an extracellular inhibitor, which supresses transcription of the ebfG-operon. Here we revealed inhibitor activity at an early growth stage and its gradual accumulation along the exponential growth phase in correlation with cell density. Data, however, do not support a threshold-like phenomenon known for quorum-sensing in heterotrophs. Together, data presented here demonstrate cell specialization and imply density-dependent regulation thereby providing deep insights into cyanobacterial communal behavior.}, }
@article {pmid36862938, year = {2023}, author = {Brezhnev, A and Tang, FK and Kwan, CS and Basabrain, MS and Tsoi, JKH and Matinlinna, JP and Neelakantan, P and Leung, KC}, title = {One-Pot Preparation of Cetylpyridinium Chloride-Containing Nanoparticles for Biofilm Eradication.}, journal = {ACS applied bio materials}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsabm.2c01080}, pmid = {36862938}, issn = {2576-6422}, abstract = {Quaternary ammonium compounds (QACs) have been widely used due to their excellent antimicrobial activity. However, using the technology where nanomaterials are employed as drug carriers to deliver QAC drugs has not been fully explored. In this study, mesoporous silica nanoparticles (MSNs) with short rod morphology were synthesized in a one-pot reaction using an antiseptic drug cetylpyridinium chloride (CPC). CPC-MSN were characterized via various methods and tested against three bacterial species (Streptococcus mutans, Actinomyces naeslundii, and Enterococcus faecalis), which are associated with oral infections, caries, and endodontic pathology. The nanoparticle delivery system used in this study prolonged the release of CPC. The manufactured CPC-MSN effectively killed the tested bacteria within the biofilm, and their size allowed them to penetrate into dentinal tubules. This CPC-MSN nanoparticle delivery system demonstrates potential for applications in dental materials.}, }
@article {pmid36862127, year = {2023}, author = {Ran, W and Yue, Y and Long, F and Zhong, K and Bai, J and Xiao, Y and Bu, Q and Huang, Y and Wu, Y and Gao, H}, title = {Antibacterial Mechanism of 2R,3R-Dihydromyricetin Against Staphylococcus aureus: Deciphering Inhibitory Effect on Biofilm and Virulence Based on Transcriptomic and Proteomic Analyses.}, journal = {Foodborne pathogens and disease}, volume = {}, number = {}, pages = {}, doi = {10.1089/fpd.2022.0075}, pmid = {36862127}, issn = {1556-7125}, abstract = {Staphylococcus aureus is a major foodborne pathogen that leads to various diseases due to its biofilm and virulence factors. This study aimed to investigate the inhibitory effect of 2R,3R-dihydromyricetin (DMY), a natural flavonoid compound, on the biofilm formation and virulence of S. aureus, and to explore the mode of action using transcriptomic and proteomic analyses. Microscopic observation revealed that DMY could remarkably inhibit the biofilm formation by S. aureus, leading to a collapse on the biofilm architecture and a decrease in viability of biofilm cell. Moreover, the hemolytic activity of S. aureus was reduced to 32.7% after treatment with subinhibitory concentration of DMY (p < 0.01). Bioinformation analysis based on RNA-sequencing and proteomic profiling revealed that DMY induced 262 differentially expressed genes and 669 differentially expressed proteins (p < 0.05). Many downregulated genes and proteins related to surface proteins were involved in biofilm formation, including clumping factor A (ClfA), iron-regulated surface determinants (IsdA, IsdB, and IsdC), fibrinogen-binding proteins (FnbA, FnbB), and serine protease. Meanwhile, DMY regulated a wide range of genes and proteins enriched in bacterial pathogenesis, cell envelope, amino acid metabolism, purine and pyrimidine metabolism, and pyruvate metabolism. These findings suggest that DMY targets S. aureus through multifarious mechanisms, and especially prompt that interference of surface proteins in cell envelope would lead to attenuation of biofilm and virulence.}, }
@article {pmid36860488, year = {2023}, author = {Poon, Y and Hui, M}, title = {Inhibitory effect of lactobacilli supernatants on biofilm and filamentation of Candida albicans, Candida tropicalis, and Candida parapsilosis.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1105949}, pmid = {36860488}, issn = {1664-302X}, abstract = {INTRODUCTION: Probiotic Lactobacillus strains had been investigated for the potential to protect against infection caused by the major fungal pathogen of human, Candida albicans. Besides antifungal activity, lactobacilli demonstrated a promising inhibitory effect on biofilm formation and filamentation of C. albicans. On the other hand, two commonly isolated non-albicans Candida species, C. tropicalis and C. parapsilosis, have similar characteristics in filamentation and biofilm formation with C. albicans. However, there is scant information of the effect of lactobacilli on the two species.<br><br>METHODS: In this study, biofilm inhibitory effects of L. rhamnosus ATCC 53103, L. plantarum ATCC 8014, and L. acidophilus ATCC 4356 were tested on the reference strain C. albicans SC5314 and six bloodstream isolated clinical strains, two each of C. albicans, C. tropicalis, and C. parapsilosis.<br><br>RESULTS AND DISCUSSION: Cell-free culture supernatants (CFSs) of L. rhamnosus and L. plantarum significantly inhibited in vitro biofilm growth of C. albicans and C. tropicalis. L. acidophilus, conversely, had little effect on C. albicans and C. tropicalis but was more effective on inhibiting C. parapsilosis biofilms. Neutralized L. rhamnosus CFS at pH 7 retained the inhibitory effect, suggesting that exometabolites other than lactic acid produced by the Lactobacillus strain might be accounted for the effect. Furthermore, we evaluated the inhibitory effects of L. rhamnosus and L. plantarum CFSs on the filamentation of C. albicans and C. tropicalis strains. Significantly less Candida filaments were observed after co-incubating with CFSs under hyphae-inducing conditions. Expressions of six biofilm-related genes (ALS1, ALS3, BCR1, EFG1, TEC1, and UME6 in C. albicans and corresponding orthologs in C. tropicalis) in biofilms co-incubated with CFSs were analyzed using quantitative real-time PCR. When compared to untreated control, the expressions of ALS1, ALS3, EFG1, and TEC1 genes were downregulated in C. albicans biofilm. In C. tropicalis biofilms, ALS3 and UME6 were downregulated while TEC1 was upregulated. Taken together, the L. rhamnosus and L. plantarum strains demonstrated an inhibitory effect, which is likely mediated by the metabolites secreted into culture medium, on filamentation and biofilm formation of C. albicans and C. tropicalis. Our finding suggested an alternative to antifungals for controlling Candida biofilm.}, }
@article {pmid36859622, year = {2023}, author = {Sasaki, H and Kurakado, S and Matsumoto, Y and Yoshino, Y and Sugita, T and Koyama, K and Kinoshita, K}, title = {Enniatins from a marine-derived fungus Fusarium sp. inhibit biofilm formation by the pathogenic fungus Candida albicans.}, journal = {Journal of natural medicines}, volume = {}, number = {}, pages = {}, pmid = {36859622}, issn = {1861-0293}, abstract = {Candidemia is a life-threatening disease common in immunocompromised patients, and is generally caused by the pathogenic fungus Candida albicans. C. albicans can change morphology from yeast to hyphae, forming biofilms on medical devices. Biofilm formation contributes to the virulence and drug tolerance of C. albicans, and thus compounds that suppress this morphological change and biofilm formation are effective for treating and preventing candidemia. Marine organisms produce biologically active and structurally diverse secondary metabolites that are promising lead compounds for treating numerous diseases. In this study, we explored marine-derived fungus metabolites that can inhibit morphological change and biofilm formation by C. albicans. Enniatin B (1), B1 (2), A1 (3), D (4), and E (5), visoltricin (6), ergosterol peroxide (7), 9,11-dehydroergosterol peroxide (8), and 3β,5α,9α-trihydroxyergosta-7,22-dien-6-one (9) were isolated from the marine-derived fungus Fusarium sp. Compounds 1-5 and 8 exhibited inhibitory activity against hyphal formation by C. albicans, and compounds 1-3 and 8 inhibited biofilm formation by C. albicans. Furthermore, compounds 1-3 decreased cell surface hydrophobicity and expression of the hypha-specific gene HWP1 in C. albicans. Compound 1 was obtained in the highest yield. An in vivo evaluation system using silkworms pierced with polyurethane fibers (a medical device substrate) showed that compound 1 inhibited biofilm formation by C. albicans in vivo. These results indicate that enniatins could be lead compounds for therapeutic agents for biofilm infections by C. albicans.}, }
@article {pmid36858631, year = {2023}, author = {Yamane, K and Niki, M and Tsubouchi, T and Watanabe, T and Asai, K and Oinuma, KI and Sakiyama, A and Saren, C and Matsumoto, Y and Makimura, K and Kaneko, Y and Kawaguchi, T}, title = {A Culture Supernatant from an Actinomycete sp. Affects Biofilm Formation and Virulence Expression of Candida auris.}, journal = {Medical mycology journal}, volume = {64}, number = {1}, pages = {7-17}, doi = {10.3314/mmj.22-00026}, pmid = {36858631}, issn = {1882-0476}, abstract = {The multidrug-resistant pathogen Candida auris is characterized by its aggregation under certain conditions, which affects its biofilm formation, drug susceptibility, and pathogenicity. Although the innate tendency to aggregate depends on the strain, the mechanism regulating C. auris aggregation remains unclear. We found that the culture supernatant from one of the 95 Actinomyces strains isolated from a deep-sea environment (IMAs2016D-66) inhibited C. auris aggregation. The cells grown in the presence of IMAs2016D-66 exhibited reduced hydrophobicity, biofilm formation, and enhanced proteolytic activity. In addition, the efflux pump activity of the fluconazole-resistant C. auris strain LSEM 3673 was stimulated by IMAs2016D-66, whereas no significant change was observed in the fluconazole-susceptible strain LSEM 0643. As the relationship between aggregative tendency and virulence in C. auris is still unclear, IMAs2016D-66 can serve as a tool for investigating regulatory mechanisms of phenotype switching and virulence expression of C. auris. Understanding of phenotype switching may help us not only to understand the pathogenicity of C. auris, but also to design new drugs that target the molecules regulating virulence factors.}, }
@article {pmid36855815, year = {2023}, author = {Singha, R and Aggarwal, R and Sanyal, K}, title = {Negative regulation of biofilm development by the CUG-Ser1 clade-specific histone H3 variant is dependent on the canonical histone chaperone CAF-1 complex in Candida albicans.}, journal = {Molecular microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mmi.15050}, pmid = {36855815}, issn = {1365-2958}, abstract = {The CUG-Ser1 clade-specific histone H3 variant (H3V[CTG]) has been reported to be a negative regulator of planktonic to biofilm growth transition in Candida albicans. The preferential binding of H3V[CTG] at the biofilm gene promoters makes chromatin repressive for biofilm-mode of growth. The two evolutionarily conserved chaperone complexes involved in incorporating histone H3 are CAF-1 and HIRA. In this study, we sought to identify the chaperone complex(es) involved in loading H3V[CTG] . We demonstrate that C. albicans cells lacking either Cac1 or Cac2 subunit of the CAF-1 chaperone complex, exhibit a hyper-filamentation phenotype on solid surfaces and form more robust biofilms than wild type cells, thereby mimicking the phenotype of the H3V[CTG] null mutant. None of the subunits of the HIRA chaperone complex shows any significant difference in biofilm growth as compared to the wild type. The occupancy of H3V[CTG] is found to be significantly reduced at the promoters of biofilm genes in the absence of CAF-1 subunits. Hence, we provide evidence that CAF-1, a chaperone known to load canonical histone H3 in mammalian cells, is involved in chaperoning of variant histone H3V[CTG] at the biofilm gene promoters in C. albicans. Our findings also illustrate the acquisition of an unconventional role of the CAF-1 chaperone complex in morphogenesis in C. albicans.}, }
@article {pmid36855334, year = {2023}, author = {Chan, RK and Nuutila, K and Mathew-Steiner, SS and Diaz, V and Anselmo, K and Batchinsky, M and Carlsson, AH and Ghosh, N and Sen, CK and Roy, S}, title = {A Prospective, Randomized, Controlled Study to Evaluate the Effectiveness of a Fabric-based Wireless Electroceutical Dressing Compared to Standard of Care Treatment Against Acute Trauma and Burn Wound Biofilm Infection.}, journal = {Advances in wound care}, volume = {}, number = {}, pages = {}, doi = {10.1089/wound.2023.0007}, pmid = {36855334}, issn = {2162-1918}, abstract = {OBJECTIVE: Despite advances in the use of topical and parenteral antimicrobial therapy and the practice of early tangential burn-wound excision to manage bacterial load, 60% of the mortality from burns is attributed to bacterial biofilm infection. A low electric field (~1V) generated by the novel FDA-cleared wireless electroceutical dressing (WED) was previously shown to significantly prevent and disrupt burn biofilm infection in preclinical studies. Based on this observation, the purpose of this clinical trial was to evaluate the efficacy of the WED dressing powered by a silver- zinc electro-couple in the prevention and disruption of biofilm infection.<br><br>APPROACH: A prospective, randomized, controlled, single center clinical trial was performed to evaluate the efficacy of the WED compared to standard of care (SoC) dressing to treat biofilms. Burn wounds were randomized to receive either SoC or WED. Biopsies were collected on days 0 and 7 for histology, scanning electron microscopy (SEM) examination of biofilm and for quantitative bacteriological analyses.<br><br>RESULTS: In total, 38 subjects were enrolled in the study. In 52% of the WED treated wounds, little to no biofilm could be detected by SEM. WED significantly lowered or prevented increase of biofilm in all wounds compared to the pair matched SoC treated wounds.<br><br>INNOVATION: WED is a simple, easy, and rapid method to protect the wound, while also inhibiting infection. It is activated by a moist environment and the electrical field induces transient and micro molar amounts of superoxide anion radicals that will prevent bacterial growth.<br><br>CONCLUSION: WED decreased biofilm infection better when compared to SoC.}, }
@article {pmid36854956, year = {2023}, author = {Ivanova, LA and Egorov, VV and Zabrodskaya, YA and Shaldzhyan, AA and Baranchikov, AY and Tsvigun, NV and Lykholay, AN and Yapryntsev, AD and Lebedev, DV and Kulminskaya, AA}, title = {Matrix is everywhere: extracellular DNA is a link between biofilm and mineralization in Bacillus cereus planktonic lifestyle.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {9}, pmid = {36854956}, issn = {2055-5008}, abstract = {To date, the mechanisms of biomineralization induced by bacterial cells in the context of biofilm formation remain the subject of intensive studies. In this study, we analyzed the influence of the medium components on the induction of CaCO3 precipitation by the Bacillus cereus cells and composition of the extracellular matrix (ECM) formed in the submerged culture. While the accumulation of extracellular polysaccharides and amyloids appeared to be independent of the presence of calcium and urea during the growth, the accumulation of extracellular DNA (eDNA), as well as precipitation of calcium carbonate, required the presence of both ingredients in the medium. Removal of eDNA, which was sensitive to treatment by DNase, did not affect other matrix components but resulted in disruption of cell network formation and a sixfold decrease in the precipitate yield. An experiment with a cell-free system confirmed the acceleration of mineral formation after the addition of exogenous salmon sperm DNA. The observed pathway for the formation of CaCO3 minerals in B. cereus planktonic culture included a production of exopolysaccharides and negatively charged eDNA lattice promoting local Ca[2+] supersaturation, which, together with an increase in the concentration of carbonate ions due to pH rise, resulted in the formation of an insoluble precipitate of calcium carbonate. Precipitation of amorphous CaCO3 on eDNA matrix was followed by crystal formation via the ACC-vaterite-calcite/aragonite pathway and further formation of larger mineral aggregates in complex with extracellular polymeric substances. Taken together, our data showed that DNA in extracellular matrix is an essential factor for triggering the biomineralization in B. cereus planktonic culture.}, }
@article {pmid36853819, year = {2023}, author = {Morselli, S and Salvo, M and Foschi, C and Lazzarotto, T and Ambretti, S and Marangoni, A}, title = {Characterization of Gardnerella vaginalis isolates: correlations among clades, biofilm formation and cytokine stimulation.}, journal = {The new microbiologica}, volume = {46}, number = {1}, pages = {56-59}, pmid = {36853819}, issn = {1121-7138}, abstract = {We characterized 61 Gardnerella vaginalis (GV) strains isolated from women with bacterial vaginosis. GV clade 1 was the most commonly found (52.5%), followed by clade 4 (36.1%). All the strains were susceptible to ampicillin and clindamycin, whereas 96.7% and 6.6% of strains showed metronidazole and tetracycline resistance, respectively. Isolates within clade 4 tended to possess the highest ability to form biofilm. Strains resistant to metronidazole and tetracycline were all intermediate or high biofilm producers. All GV clades significantly upregulated the production of pro-inflammatory cytokines by HeLa cells, especially IL-8 and IL-6. Clade 4 induced a significantly higher production of IL-1β compared to other clades.}, }
@article {pmid36853055, year = {2023}, author = {Bianchini Fulindi, R and Domingues Rodrigues, J and Lemos Barbosa, TW and Goncalves Garcia, AD and de Almeida La Porta, F and Pratavieira, S and Chiavacci, LA and Pessoa Araújo Junior, J and da Costa, PI and Martinez, LR}, title = {Zinc-Based Nanoparticles Reduce Bacterial Biofilm Formation.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0483122}, doi = {10.1128/spectrum.04831-22}, pmid = {36853055}, issn = {2165-0497}, abstract = {Biofilm formation is important for microbial survival in hostile environments and a phenotype that provides microorganisms with antimicrobial resistance. Zinc oxide (ZnO) and Zinc sulfide (ZnS) nanoparticles (NPs) present potential antimicrobial properties for biomedical and food industry applications. Here, we aimed to analyze, for the first time, the bactericidal and antibiofilm activity of ZnS NPs against Staphylococcus aureus, Klebsiella oxytoca, and Pseudomonas aeruginosa, all medically important bacteria in developed countries. We compared ZnS NPs antimicrobial activity to ZnO NPs, which have been extensively studied. Using the colorimetric XTT reduction assay to observe the metabolic activity of bacterial cells and the crystal violet assay to measure biofilm mass, we demonstrated that ZnS and ZnO had similar efficacy in killing planktonic bacterial cells and reducing biofilm formation, with S. aureus being more susceptible to both therapeutics than K. oxytoca and P. aeruginosa. Crystal violet staining and confocal microscopy validated that Zn NPs inhibit biofilm formation and cause architectural damage. Our findings provide proof of principle that ZnS NPs have antibiofilm activity, and can be potentially used in medical and food industry applications, such as treatment of wound infections or package coating for food preservation. IMPORTANCE Zinc (Zn)-based nanoparticles (NPs) can be potentially used in medical and food preservation applications. As proof of principle, we investigated the bactericidal and antibiofilm activity of zinc oxide (ZnO) and zinc sulfide (ZnS) NPs against medically important bacteria. Zn-based NPs were similarly effective in killing planktonic and biofilm-associated Staphylococcus aureus, Klebsiella oxytoca, and Pseudomonas aeruginosa cells. However, S. aureus was more susceptible to these investigational therapeutics. Although further studies are warranted, our findings suggest the possibility of future use of Zn-based NPs in the treatment of skin infections or preservation of food.}, }
@article {pmid36850031, year = {2023}, author = {Li, Q and Liu, Q and Wang, Z and Zhang, X and Ma, R and Hu, X and Mei, J and Su, Z and Zhu, W and Zhu, C}, title = {Biofilm Homeostasis Interference Therapy via [1] O2 -Sensitized Hyperthermia and Immune Microenvironment Re-Rousing for Biofilm-Associated Infections Elimination.}, journal = {Small (Weinheim an der Bergstrasse, Germany)}, volume = {}, number = {}, pages = {e2300592}, doi = {10.1002/smll.202300592}, pmid = {36850031}, issn = {1613-6829}, abstract = {The recurrence of biofilm-associated infections (BAIs) remains high after implant-associated surgery. Biofilms on the implant surface reportedly shelter bacteria from antibiotics and evade innate immune defenses. Moreover, little is currently known about eliminating residual bacteria that can induce biofilm reinfection. Herein, novel "interference-regulation strategy" based on bovine serum albumin-iridium oxide nanoparticles (BIONPs) as biofilm homeostasis interrupter and immunomodulator via singlet oxygen ([1] O2)-sensitized mild hyperthermia for combating BAIs is reported. The catalase-like BIONPs convert abundant H2 O2 inside the biofilm-microenvironment (BME) to sufficient oxygen gas (O2), which can efficiently enhance the generation of [1] O2 under near-infrared irradiation. The [1] O2 -induced biofilm homeostasis disturbance (e.g., sigB, groEL, agr-A, icaD, eDNA) can disrupt the sophisticated defense system of biofilm, further enhancing the sensitivity of biofilms to mild hyperthermia. Moreover, the mild hyperthermia-induced bacterial membrane disintegration results in protein leakage and [1] O2 penetration to kill bacteria inside the biofilm. Subsequently, BIONPs-induced immunosuppressive microenvironment re-rousing successfully re-polarizes macrophages to pro-inflammatory M1 phenotype in vivo to devour residual biofilm and prevent biofilm reconstruction. Collectively, this [1] O2 -sensitized mild hyperthermia can yield great refractory BAIs treatment via biofilm homeostasis interference, mild-hyperthermia, and immunotherapy, providing a novel and effective anti-biofilm strategy.}, }
@article {pmid36849163, year = {2023}, author = {Xiong, Q and Qu, J and Zhao, R and Chen, Y and Li, Y and Xu, W and Pan, B and Jin, P and Zheng, Z}, title = {Fabrication of a novel polyurethane foam-alginate-zeolite hydrogel and subsequent KSND bacteria encapsulation: evidence of accelerated biofilm colonisation and enhanced nitrogen removal efficiency.}, journal = {Letters in applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/lambio/ovac054}, pmid = {36849163}, issn = {1472-765X}, abstract = {Biofilms are used widely to remove nitrogen from wastewater; however, most biofilm carriers (i.e. polyurethane foam, PUF) are hydrophobic organic materials with millimetre-scale apertures, ineffective attachment, and unstable colonisation of microorganisms. To address these limitations, hydrophilic sodium alginate (SA) mixed with zeolite powder (Zeo) was crosslinked in PUF to form a micro-scale hydrogel (PAS) with a well-organised and reticular cellular structure. Scanning electron microscopy revealed that immobilised cells were entrapped in the interior of hydrogel filaments and rapidly formed a stable biofilm on the surface. The biofilm generated was 10.3-fold greater than the film developed on PUF. Kinetics and isotherm studies revealed that the as-developed carrier, because of the presence of Zeo, effectively improved the adsorption of NH4+-N by 53%. The PAS carrier achieved total nitrogen removal in excess of 86% for low carbon-to-nitrogen ratio wastewater treated for 30 d, indicating that this novel modification-encapsulation technology has potential for wastewater treatment.}, }
@article {pmid36848732, year = {2023}, author = {Brunswick, P and Blajkevitch, O and Filewood, T and Kent, E and Drever, MC and Elner, RW and Shang, D}, title = {Long chain fatty acids analysis of intertidal biofilm by direct injection liquid chromatography time of flight mass spectrometry.}, journal = {Journal of chromatography. A}, volume = {1693}, number = {}, pages = {463870}, doi = {10.1016/j.chroma.2023.463870}, pmid = {36848732}, issn = {1873-3778}, abstract = {The critical importance of mono- and polyunsaturated fatty acids (FAs) in a variety of biological functions, including animal nutrition and as an environmental stress monitor, is well recognized. However, while methods exist for monitoring of fatty acids, few are specific either to the profile of a microphytobenthos matrix or practical in application to multiple, diverse intertidal biofilm sample sets. In the current study, a sensitive liquid chromatography (LC) quadrupole time of flight mass spectrometry (QTOF) method was developed for the quantitative analysis of 31 FAs specific to intertidal biofilm, a thin mucilaginous layer of microalgae, bacteria, and other organisms on the surface of coastal mudflats, which provide a rich source of FAs for migratory birds. Preliminary screening of diverse biofilm samples collected from shorebird feeding grounds highlighted eight saturated (SFA), seven monounsaturated (MUFA), and sixteen polyunsaturated FAs (PUFA) that were selected for analysis. Improved method detection limits in the range 0.3-2.6 ngmL[-1] were achieved, excepting for stearic acid at 10.6 ngmL[-1]. These excellent results were obtained without use of complex sample extraction and clean-up procedures undertaken by other published methods. An alkaline matrix of dilute aqueous ammonium hydroxide with methanol was shown to be selective for extraction and stability of the more hydrophilic fatty acid components. The direct injection method showed excellent precision and accuracy both during validation and application to hundreds of real-world intertidal biofilm samples from the Fraser River estuary (British Columbia, Canada) and other areas of the region frequented by shoreline birds.}, }
@article {pmid36847907, year = {2023}, author = {Fatima, T and Fatima, Z and Hameed, S}, title = {Abrogation of efflux pump activity, biofilm formation, and immune escape by candidacidal geraniol in emerging superbug, Candida auris.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {36847907}, issn = {1618-1905}, abstract = {During the last decade, Candida auris emerged as a threatening human fungal pathogen that notably caused outbreaks around the globe with high mortality. Considering C. auris species as newly discovered fungi, the evolutionary features remain elusive. The antifungal resistance which is a norm in C. auris underlines the need for innovative therapeutic options. ATP Binding Cassette (ABC) superfamily efflux pumps overexpression and biofilms are known to be major contributors to multidrug resistance (MDR) in C. auris. Therefore, herein, we investigated the antifungal potential of geraniol (Ger) as a promising natural compound in the fight against MDR C. auris. Our experiments proved that Ger was fungicidal in nature and impaired rhodamine 6G (R6G) efflux, confirming the specific effect on ABC transporters. Kinetic studies unravelled the competitive mode of inhibition by Ger for R6G efflux since the apparent Km increased with no change in Vmax value. Mechanistic insights also revealed that Ger depleted ergosterol content in C. auris. Furthermore, Ger led to inhibition in biofilm formation as evident from crystal violet staining, biofilm metabolic and biomass measurements. Additionally, enhanced survival of Caenorhabditis elegans model after C. auris infection demonstrated the in vivo efficacy of Ger. Lastly, the in vivo efficacy was confirmed from a THP-1 cell line model which depicted enhanced macrophage-mediated killing in the presence of Ger. Modulation of C. auris efflux pump activity and biofilm formation by Ger represents a promising approach to combat MDR. Together, this study demonstrated the potential therapeutic insights of Ger as a promising addition to the antifungal armamentarium required to treat emerging and resistant C. auris.}, }
@article {pmid36847713, year = {2023}, author = {Bravo, E and Serrano, B and Ribeiro-Vidal, H and Virto, L and Sanz Sánchez, I and Herrera, D and Sanz, M}, title = {Biofilm formation on dental implants with a hybrid surface microtopography. An in vitro study in a validated multispecies dynamic biofilm model.}, journal = {Clinical oral implants research}, volume = {}, number = {}, pages = {}, doi = {10.1111/clr.14054}, pmid = {36847713}, issn = {1600-0501}, abstract = {OBJECTIVES: To qualitatively and quantitatively evaluate biofilm formation on hybrid titanium implants (HS), with moderately rough and turned surface topographies.<br><br>MATERIALS AND METHODS: A validated dynamic in vitro multi-species biofilm model, based on bacterial growth under flow and shear conditions resembling the oral cavity, was used to evaluate biofilm formation on the tested implant surfaces. Scanning Electron Microscope (SEM) and Confocal Laser Scanning Microscopy (CLSM) were used to compare the biofilm structure and microbial biomass deposited on either the moderately rough or the turned surface of HS. Quantitative polymerase chain reaction (qPCR) was used to evaluate the total bacterial counts and counts of each specific bacterium in biofilms formed on implants with either the moderately rough or the turned surfaces, as in the hybrid titanium implants, after 24, 48 and 72 h. A general linear model was applied to compare the CLSM and qPCR results between the tested implant surfaces.<br><br>RESULTS: A significantly higher bacterial biomass grew on the moderately rough implant surfaces, compared to the turned surface area of HS implants (p<0.05), at all incubation times, as evidenced with both CLSM and SEM. qPCR analysis also demonstrated an important increase in the total and specific bacterial counts in moderately rough surface implants at the three incubation times.<br><br>CONCLUSIONS: Implant surface topography (moderately rough versus turned) significantly influenced in vitro biofilm formation in terms of biofilm structure, bacterial biomass and quantity of the specific species selected for the model used.}, }
@article {pmid36847700, year = {2023}, author = {Virto, L and Odeh, V and Garcia-Quismondo, E and Herrera, D and Palma, J and Tamimi, F and Sanz, M}, title = {Electrochemical decontamination of titanium dental implants. An in vitro biofilm model study.}, journal = {Clinical oral implants research}, volume = {}, number = {}, pages = {}, doi = {10.1111/clr.14055}, pmid = {36847700}, issn = {1600-0501}, abstract = {OBJECTIVES: To study the effect of electrochemical treatment on biofilms developed on titanium dental implants, using a six-species in vitro model simulating subgingival oral biofilms.<br><br>MATERIALS AND METHODS: Direct electrical current (DC) of 0.75V, 1.5V and 3V (anodic polarization, oxidation processes) and of -0.75V, -1.5V and -3V (cathodic polarization, reduction processes) was applied between the working and the reference electrodes for 5 minutes on titanium dental implants, which have been previously inoculated with a multispecies biofilm. This electrical application consisted of a three-electrode system where the implant was the working electrode, a platinum mesh was the counter electrode, and an Ag/AgCl electrode was the reference. The effect of the electrical application on the biofilm structure and bacterial composition was evaluated by scanning electron microscopy and quantitative polymerase chain reaction. A generalized linear model was applied to study the bactericidal effect of the proposed treatment.<br><br>RESULTS: The electrochemical construct at 3V and -3V settings significantly reduced total bacterial counts (p<0.05) from 3.15 x 10[6] to 1.85 x 10[5] and 2.92 x 10[4] live bacteria/mL respectively. Fusobacterium nucleatum was the most affected species in terms of reduction in concentration. The 0.75V and -0.75V treatments had no effect on the biofilm.<br><br>CONCLUSION: Electrochemical treatments had a bactericidal effect on this multispecies subgingival in vitro biofilm model, being the reduction more effective than the oxidative treatment.}, }
@article {pmid36847543, year = {2023}, author = {Dong, J and Liu, L and Chen, L and Xiang, Y and Wang, Y and Zhao, Y}, title = {The Coexistence of Bacterial Species Restructures Biofilm Architecture and Increases Tolerance to Antimicrobial Agents.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0358122}, doi = {10.1128/spectrum.03581-22}, pmid = {36847543}, issn = {2165-0497}, abstract = {Chronic infections caused by polymicrobial biofilms are often difficult to treat effectively, partially due to the elevated tolerance of polymicrobial biofilms to antimicrobial treatments. It is known that interspecific interactions influence polymicrobial biofilm formation. However, the underlying role of the coexistence of bacterial species in polymicrobial biofilm formation is not fully understood. Here, we investigated the effect of the coexistence of Enterococcus faecalis, Escherichia coli O157:H7, and Salmonella enteritidis on triple-species biofilm formation