@article {pmid38723699,
year = {2024},
author = {Jo, S and Chao, C and Khilnani, TK and Shenoy, A and Bostrom, MPG and Carli, AV},
title = {The Infected Polypropylene Mesh: When Does Biofilm Form and Which Antiseptic Solution Most Effectively Removes It?.},
journal = {The Journal of arthroplasty},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.arth.2024.04.081},
pmid = {38723699},
issn = {1532-8406},
abstract = {BACKGROUND: Polypropylene (PPE) mesh is commonly utilized to reconstruct catastrophic extensor mechanism disruptions in revision total knee arthroplasty. Unfortunately, these procedures are associated with a high rate of periprosthetic joint infection (PJI). The purpose of the current study was to: 1) visualize and quantify the progression of bacterial biofilm growth on PPE-mesh; and 2) determine which antiseptic solutions effectively remove viable bacteria.

METHODS: Knitted PPE mesh samples were cultured with either methicillin-sensitive Staphylococcus aureus (MSSA) or Escherichia coli (E. coli) for 7 days, with regular quantification of colony forming units (CFUs) and visualization using scanning electron microscopy (SEM) to identify maturity. Immature (24 hour) and mature (72 hour) biofilm was treated with one of five commercial antiseptics for three minutes. A 0.05% chlorhexidine gluconate, a surfactant-based formulation of ethanol, acetic acid, sodium acetate, benzalkonium chloride, diluted povidone-iodine (0.35%), undiluted (10%) povidone-iodine, and 1:1 combination of 10% povidone-iodine and 3% hydrogen peroxide. A three-log reduction in colony-forming units (CFUs) compared to saline was considered clinically meaningful.

RESULTS: The CFU counts plateaued, indicating maturity, at 72 hours for both MSSA and E. coli. The SEM confirmed confluent biofilm formation after 72 hours. The 10% povidone-iodine was clinically effective against all MSSA biofilms and immature E. coli biofilms. The 10% povidone-iodine with hydrogen peroxide was effective in all conditions. Only 10% povidone iodine formulations produced significantly (P < 0.0083) reduced CFU counts against mature biofilms.

CONCLUSION: Bacteria rapidly form biofilm on PPE mesh. Mesh contamination can be catastrophic, and clinicians should consider utilizing an antiseptic solution at the conclusion of mesh implantation. Undiluted povidone-iodine with hydrogen peroxide should be considered when attempting to salvage infected PPE mesh.},
}

@article {pmid38723695,
year = {2024},
author = {Kim, BH and Ashrafudoulla, M and Shaila, S and Park, HJ and Sul, JD and Park, SH and Ha, SD},
title = {Isolation, characterization, and application of bacteriophage on Vibrio parahaemolyticus biofilm to control seafood contamination.},
journal = {International journal of antimicrobial agents},
volume = {},
number = {},
pages = {107194},
doi = {10.1016/j.ijantimicag.2024.107194},
pmid = {38723695},
issn = {1872-7913},
abstract = {This study intended to isolate a Vibrio-particular phage from the natural environment, analyze its characteristics and genome sequence, and investigate its reduction effect on V. parahaemolyticus biofilm as a biocontrol agent in squid and mackerel. Among 21 phages, phage CAU_VPP01, isolated from beach mud, was chosen for further experiments based on host range and EOP tests. When examining the reduction effect of phage CAU_VPP01 against Vibrio parahaemolyticus biofilms on surfaces (stainless steel [SS] and polyethylene terephthalate [PET]) and food surfaces (squid and mackerel), the phage showed the most excellent reduction effect at a multiplicity-of-infection (MOI) 10. Three-dimensional images acquired with confocal laser scanning microscopy (CLSM) analysis were quantified using COMSTAT, which showed that biomass, average thickness, and roughness coefficient decreased when treated with the phage. Color and texture analysis confirmed that the quality of squid and mackerel was maintained after the phage treatment. Finally, a comparison of gene expression levels determined by qRT-PCR analysis showed that the phage treatment induced a decrease in the gene expression of flaA, vp0962, and luxS, as examples. This study indicated that Vibrio-specific phage CAU_VPP01 effectively controlled V. parahaemolyticus biofilms under various conditions and confirmed that the isolated phage could possibly be used as an effective biocontrol weapon in the seafood manufacturing industry.},
}

@article {pmid38723502,
year = {2024},
author = {Yan, Z and Han, X and Wang, H and Jin, Y and Song, X},
title = {Influence of aeration modes and DO on simultaneous nitrification and denitrification in treatment of hypersaline high-strength nitrogen wastewater using sequencing batch biofilm reactor (SBBR).},
journal = {Journal of environmental management},
volume = {359},
number = {},
pages = {121075},
doi = {10.1016/j.jenvman.2024.121075},
pmid = {38723502},
issn = {1095-8630},
abstract = {Sequencing batch biofilm reactor (SBBR) has the potential to treat hypersaline high-strength nitrogen wastewater by simultaneous nitrification-denitrification (SND). Dissolved oxygen (DO) and aeration modes are major factors affecting pollutant removal. Low DO (0.35-3.5 mg/L) and alternative anoxic/aerobic (A/O) mode are commonly used for municipal wastewater treatment, however, the appropriate DO concentration and operation mode are still unknown under hypersaline environment because of the restricted oxygen transfer in denser extracellular polymeric substances (EPS) barrier and the decreased carbon source consumption during the anoxic phase. Herein, two SBBRs (R1, fully aerobic mode; R2, A/O mode) were used for the treatment of hypersaline high-strength nitrogen wastewater (200 mg/L NH4[+]-N, COD/N of 3 and 3% salinity). The results showed that the relatively low DO (2 mg/L) could not realize effective nitrification, while high DO (4.5 mg/L) evidently increased nitrification efficiency by enhancing oxygen transfer in denser biofilm that was stimulated by high salinity. A stable SND was reached 16 days faster with a ∼10% increase of TN removal under A/O mode. Mechanism analysis found that denser biofilm with coccus and bacillus were present in A/O mode instead of filamentous microorganisms, with the secretion of more EPS. Corynebacterium and Halomonas were the dominant genera in both SBBRs, and HN-AD process might assist partial nitrification-denitrification (PND) for highly efficient TN removal in biofilm systems. By using the appropriate operation mode and parameters, the average NH4[+]-N and TN removal efficiency could respectively reach 100% and 70.8% under the NLR of 0.2 kg N·m[-3]·d[-1] (COD/N of 3), which was the highest among the published works using SND-based SBBRs in treatment of saline high-strength ammonia nitrogen (low COD/N) wastewater. This study provided new insights in biofilm under hypersaline stress and provided a solution for the treatment of hypersaline high-strength nitrogen (low COD/N) water.},
}

@article {pmid38723421,
year = {2024},
author = {Reis-Neta, GRD and Ricomini-Filho, AP and Martorano-Fernandes, L and Vargas-Moreno, VF and Cury, AADB and Marcello-Machado, RM},
title = {Effect of hydroxyapatite nanoparticles coating of titanium surface on biofilm adhesion: An in vitro study.},
journal = {Archives of oral biology},
volume = {164},
number = {},
pages = {105986},
doi = {10.1016/j.archoralbio.2024.105986},
pmid = {38723421},
issn = {1879-1506},
abstract = {AIM: To evaluate the adhesion of mono and duospecies biofilm on a commercially available dental implant surface coated with hydroxyapatite nanoparticles (nanoHA).

MATERIAL AND METHODS: Titanium discs were divided into two groups: double acid-etched (AE) and AE coated with nanoHA (NanoHA). Surface characteristics evaluated were morphology, topography, and wettability. Mono and duospecies biofilms of Streptococcus sanguinis (S. sanguinis) and Candida albicans (C. albicans) were formed. Discs were exposed to fetal bovine serum (FBS) to form the pellicle. Biofilm was growth in RPMI1640 medium with 10% FBS and 10% BHI medium for 6 h. Microbial viability was evaluated using colony-forming unit and metabolic activity by a colorimetric assay of the tetrazolium salt XTT. Biofilm architecture and organization were evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM).

RESULTS: AE surface had more pores, while NanoHA had even nanoHA crystals distribution. Roughness was similar (AE: 0.59 ± 0.07 µm, NanoHA: 0.69 ± 0.18 µm), but wettability was different (AE: Θw= 81.79 ± 8.55°, NanoHA: Θw= 53.26 ± 11.86°; P = 0.01). NanoHA had lower S. sanguinis viability in monospecies biofilm (P = 0.007). Metabolic activity was similar among all biofilms. In SEM both surfaces on C. albicans biofilm show a similar distribution of hyphae in mono and duospecies biofilms. AE surface has more S. sanguinis than the NanoHA surface in the duospecies biofilm. CLSM showed a large proportion of live cells in all groups.

CONCLUSIONS: The nanoHA surface reduced the adhesion of S. sanguinis biofilm but did not alter the adhesion of C. albicans or the biofilm formed by both species.},
}

@article {pmid38723349,
year = {2024},
author = {Zhang, H and Cheng, Y and Qiu, L and Zeng, W and Hu, T and Yang, J and Wang, J and Wang, H and Gong, W and Liang, H},
title = {In situ electron generation through Fe/C supported sludge coupled with a counter-diffusion biofilm for electron-deficient wastewater treatment: Binding properties and catalytic competition mechanism of nitrate reductase.},
journal = {Water research},
volume = {257},
number = {},
pages = {121688},
doi = {10.1016/j.watres.2024.121688},
pmid = {38723349},
issn = {1879-2448},
abstract = {A membrane-aerated biofilm-coupled Fe/C supported sludge system (MABR-Fe/C) was constructed to achieve in situ electron production for NO3[-]-N reduction enhancement in different Fe/C loadings (10 g and 200 g). The anoxic environment formed in the MABR-Fe/C promoted a continual Fe[2+]release of Fe/C in 120 d operation (average Fe[2+]concentrations is 1.18 and 2.95 mg/L in MABR-Fe/C10 and MABR-Fe/C200, respectively). Metagenomics results suggested that the electrons generated from ongoing Fe[2+] oxidation were transferred via the Quinone pool to EC 1.7.5.1 rather than EC 1.9.6.1 to complete the process of NO3[-]-N reduction to NO2[-]-N in Acidovorax, Ottowia, and Polaromonas. In the absence of organic matter, the NO3[-]-N removal in MABR-Fe/C10 and MABR-Fe/C200 increased by 11.99 and 12.52 mg/L, respectively, compared to that in MABR. In the further NO2[-]-N reduction, even if the minimum binding free energy (MBFE) was low, NO2[-]-N in Acidovorax and Dechloromonas preferentially bind the Gln-residues for dissimilatory nitrate reduction (DNR) in the presence of Fe/C. Increasing Fe/C loading (MABR-Fe/C200) caused the formation of different residue binding sites, further enhancing the already dominant DNR. When DNR in MABR-Fe/C200 intensified, the TN in the effluent increased by 3.75 mg/L although the effluent NO3[-]-N concentration was lower than that in MABR-Fe/C10. This study demonstrated a new MABR-Fe/C system for in situ electron generation to enhance biological nitrogen removal and analyzed the NO3[-]-N reduction pathway and metabolic mechanism, thus providing new ideas for nitrogen removal in electron-deficient wastewater.},
}

@article {pmid38722774,
year = {2024},
author = {Noori, R and Bano, N and Ahmad, S and Mirza, K and Mazumder, JA and Perwez, M and Raza, K and Manzoor, N and Sardar, M},
title = {Microbial Biofilm Inhibition Using Magnetic Cross-Linked Polyphenol Oxidase Aggregates.},
journal = {ACS applied bio materials},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsabm.4c00175},
pmid = {38722774},
issn = {2576-6422},
abstract = {Microbial biofilm accumulation poses a serious threat to the environment, presents significant challenges to different industries, and exhibits a large impact on public health. Since there has not been a conclusive answer found despite various efforts, the potential green and economical methods are being focused on, particularly the innovative approaches that employ biochemical agents. In the present study, we propose a bio-nanotechnological method using magnetic cross-linked polyphenol oxidase aggregates (PPO m-CLEA) for inhibition of microbial biofilm including multidrug resistant bacteria. Free PPO solution showed only 55-60% biofilm inhibition, whereas m-CLEA showed 70-75% inhibition, as confirmed through microscopic techniques. The carbohydrate and protein contents in biofilm extracellular polymeric substances (EPSs) were reduced significantly. The m-CLEA demonstrated reusability up to 5 cycles with consistent efficiency in biofilm inhibition. Computational work was also done where molecular docking of PPO with microbial proteins associated with biofilm formation was conducted, resulting in favorable binding scores and inter-residual interactions. Overall, both in vitro and in silico results suggest that PPO interferes with microbial cell attachment and EPS formation, thereby preventing biofilm colonization.},
}

@article {pmid38722243,
year = {2024},
author = {Perasoli, FB and B Silva, LS and C Figueiredo, BI and Pinto, IC and F Amaro, LJ and S Almeida Bastos, JC and Carneiro, SP and R Araújo, VP and G Beato, FR and M Barboza, AP and M Teixeira, LF and Gallagher, MP and Bradley, M and Venkateswaran, S and H Dos Santos, OD},
title = {Poly(methylmethacrylate-co-dimethyl acrylamide)-silver nanocomposite prevents biofilm formation in medical devices.},
journal = {Nanomedicine (London, England)},
volume = {},
number = {},
pages = {},
doi = {10.1080/17435889.2024.2345044},
pmid = {38722243},
issn = {1748-6963},
support = {//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; 01//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; APQ02429-22, APQ01953-22//Fundação de Amparo à Pesquisa do Estado de Minas Gerais/ ; },
abstract = {Aim: To investigate whether medical devices coated with a synthesized nanocomposite of poly(methylmethacrylate-co-dimethyl acrylamide) (PMMDMA) and silver nanoparticles (AgNPs) could improve their antibiofilm and antimicrobial activities. We also investigated the nanocomposite's safety. Materials & methods: The nanocomposite was synthesized and characterized using analytical techniques. Medical devices coated with the nanocomposite were evaluated for bacterial adhesion and hemolytic activity in vitro. Results: The nanocomposite formation was demonstrated with the incorporation of AgNPs into the polymer matrix. The nanocomposite proved to be nonhemolytic and significantly inhibited bacterial biofilm formation. Conclusion: The PMMDMA-AgNPs nanocomposite was more effective in preventing biofilm formation than PMMDMA alone and is a promising strategy for coating medical devices and reducing mortality due to hospital-acquired infections.},
}

@article {pmid38722159,
year = {2024},
author = {Jarrett, CO and Leung, JM and Motoshi, S and Sturdevant, DE and Zhang, Y and Hoyt, FH and Hinnebusch, BJ},
title = {Role of the Yersinia pestis phospholipase D (Ymt) in the initial aggregation step of biofilm formation in the flea.},
journal = {mBio},
volume = {},
number = {},
pages = {e0012424},
doi = {10.1128/mbio.00124-24},
pmid = {38722159},
issn = {2150-7511},
abstract = {UNLABELLED: Transmission of Yersinia pestis by fleas depends on the formation of condensed bacterial aggregates embedded within a gel-like matrix that localizes to the proventricular valve in the flea foregut and interferes with normal blood feeding. This is essentially a bacterial biofilm phenomenon, which at its end stage requires the production of a Y. pestis exopolysaccharide that bridges the bacteria together in a cohesive, dense biofilm that completely blocks the proventriculus. However, bacterial aggregates are evident within an hour after a flea ingests Y. pestis, and the bacterial exopolysaccharide is not required for this process. In this study, we characterized the biochemical composition of the initial aggregates and demonstrated that the yersinia murine toxin (Ymt), a Y. pestis phospholipase D, greatly enhances rapid aggregation following infected mouse blood meals. The matrix of the bacterial aggregates is complex, containing large amounts of protein and lipid (particularly cholesterol) derived from the flea's blood meal. A similar incidence of proventricular aggregation occurred after fleas ingested whole blood or serum containing Y. pestis, and intact, viable bacteria were not required. The initial aggregation of Y. pestis in the flea gut is likely due to a spontaneous physical process termed depletion aggregation that occurs commonly in environments with high concentrations of polymers or other macromolecules and particles such as bacteria. The initial aggregation sets up subsequent binding aggregation mediated by the bacterially produced exopolysaccharide and mature biofilm that results in proventricular blockage and efficient flea-borne transmission.

IMPORTANCE: Yersinia pestis, the bacterial agent of plague, is maintained in nature in mammal-flea-mammal transmission cycles. After a flea feeds on a mammal with septicemic plague, the bacteria rapidly coalesce in the flea's digestive tract to form dense aggregates enveloped in a viscous matrix that often localizes to the foregut. This represents the initial stage of biofilm development that potentiates transmission of Y. pestis when the flea later bites a new host. The rapid aggregation likely occurs via a depletion-aggregation mechanism, a non-canonical first step of bacterial biofilm development. We found that the biofilm matrix is largely composed of host blood proteins and lipids, particularly cholesterol, and that the enzymatic activity of a Y. pestis phospholipase D (Ymt) enhances the initial aggregation. Y. pestis transmitted by flea bite is likely associated with this host-derived matrix, which may initially shield the bacteria from recognition by the host's intradermal innate immune response.},
}

@article {pmid38721917,
year = {2024},
author = {Wang, J and Mao, D and Dai, B and Rui, Y},
title = {Silicon-induced biofilm improves peripheral nerve defect in rats mediated by VEGF/VEGFR2/ERK.},
journal = {Neurological research},
volume = {},
number = {},
pages = {1-9},
doi = {10.1080/01616412.2024.2352232},
pmid = {38721917},
issn = {1743-1328},
abstract = {Background: Injury of peripheral nerve capable of regeneration with much poorer prognosis affects people's life quality. The recovery of nerve function after transplantation for peripheral nerve injury remain a worldwide problem. Silicon-induced biofilms as vascularized biological conduits can promote nerve regeneration by encapsulating autologous or allogeneic nerve graft.Objective: We proposed to explore the effect of silicon-induced biofilms on nerves regeneration and whether the VEGF/VEGFR2/ERK pathway was involved in the present study.Methods: Biofilms around the transplanted nerves in peripheral nerve injury rats were induced by silicon. Vascularization and proteins related to VEGF/VEGFR2/ERK were measured. Pathology and morphology of nerves were investigated after encapsulating the transplanted nerves by silicon-induced biofilms.Results: Our results indicated that the biofilms induced by silicon for 6 weeks showed the most intensive vascularization and the optimal effect on nerve regeneration. Moreover, silicon-induced biofilms for 4, 6 and 8 weeks could significantly secrete VEGF with the highest content at week 6 after induction. VEGFR2, VEGF, p-VEGFR2, ERK1, ERK2, p-ERK1 and p-ERK2 were expressed in the biofilms. p-VEGFR2, p-ERK1 and p-ERK2 expression were different at each time point and significantly increased at week 6 compared with that at week 4 or week 8 which was consistent with that 6 week of was the optimum time for biofilms induction to improve the nerve repair after peripheral nerve injury.Conclusion: Our results suggested that combination of silicon-induced autologous vascularized biofilm and autologous transplantation may promote the repair of rat sciatic nerve defect quickly through VEGF/VEGFR2/ERK pathway.},
}

@article {pmid38720923,
year = {2024},
author = {Ezeh, CK and Dibua, MEU},
title = {Anti-biofilm, drug delivery and cytotoxicity properties of dendrimers.},
journal = {ADMET & DMPK},
volume = {12},
number = {2},
pages = {239-267},
pmid = {38720923},
issn = {1848-7718},
abstract = {BACKGROUND AND PURPOSE: Treatments using antimicrobial agents have faced many difficulties as a result of biofilm formation by pathogenic microorganisms. The biofilm matrix formed by these microorganisms prevents antimicrobial agents from penetrating the interior where they can exact their activity effectively. Additionally, extracellular polymeric molecules associated with biofilm surfaces can absorb antimicrobial compounds, lowering their bioavailability. This problem has resulted in the quest for alternative treatment protocols, and the development of nanomaterials and devices through nanotechnology has recently been on the rise.

RESEARCH APPROACH: The literature on dendrimers was searched for in databases such as Google Scholar, PubMed, and ScienceDirect.

KEY RESULTS: As a nanomaterial, dendrimers have found useful applications as a drug delivery vehicle for antimicrobial agents against biofilm-mediated infections to circumvent these defense mechanisms. The distinctive properties of dendrimers, such as multi-valency, biocompatibility, high water solubility, non-immunogenicity, and biofilm matrix-/cell membrane fusogenicity (ability to merge with intracellular membrane or other proteins), significantly increase the efficacy of antimicrobial agents and reduce the likelihood of recurring infections.

CONCLUSION: This review outlines the current state of dendrimer carriers for biofilm treatments, provides examples of their real-world uses, and examines potential drawbacks.},
}

@article {pmid38720728,
year = {2024},
author = {Abdelrazek, HM and Ghozlan, HA and Sabry, SA and Abouelkheir, SS},
title = {Copper oxide nanoparticles (CuO-NPs) as a key player in the production of oil-based paint against biofilm and other activities.},
journal = {Heliyon},
volume = {10},
number = {9},
pages = {e29758},
pmid = {38720728},
issn = {2405-8440},
abstract = {Copper oxide nanoparticles are among the metal nanoparticles gaining popularity in many biotechnological fields, particularly in marine environments. Their antimicrobial and antibiofilm activities make them appealing to many researchers. Among the various methods of producing nanoparticles, biosynthesis is crucial. Thus, a large number of reports have been made about the microbiological manufacture of these nanoparticles by bacteria. Nevertheless, bio-production by means of the cell-free supernatant of marine bacteria is still in its primary phase. This is landmark research to look at how bacteria make a lot (14 g/L) of copper oxide nanoparticles (CuO-NPs) via the cell-free supernatant of Bacillus siamensis HS, their characterization, and their environmental and medical approaches. The biosynthesized nanoparticles were characterized using a UV-visible spectrum range that provides two maximum absorption peaks, one obtained at 400 nm and the other around 550-600 nm. Diffraction of X-rays (XRD) clarifies that the size of the NPs obtained was estimated to be 18 nm using Debye-Scherrer's equation. Scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX) displays 91.93 % copper oxide purity. The Transmission Electron Microscope (TEM) image proves that the particles have a spherical form and an average diameter of 6.54-8.60 nm. At the environmental level, nanoparticles incorporated into oil-based paint can be used as antibiofilm tools to diminish the biofilm formed on the submerged surface in the marine environment. In disease management, NPs can be used as a wound healing agent to reduce the wound gap size as well as an anti-tumour agent to control liver cancer cells (hepatoma cells (HepG2)).},
}

@article {pmid38719003,
year = {2024},
author = {Wen, H and Zhang, Y and Mi, Z and Zhang, H and Sun, C and Liu, X and Fan, X},
title = {Rational design of PspAlgL to improve its thermostability and anti-biofilm activity against Pseudomonas aeruginosa.},
journal = {International journal of biological macromolecules},
volume = {269},
number = {Pt 1},
pages = {132084},
doi = {10.1016/j.ijbiomac.2024.132084},
pmid = {38719003},
issn = {1879-0003},
abstract = {Pseudomonas aeruginosa biofilm enhances tolerance to antimicrobials and immune system defenses. Alginate is an important component of biofilm and a virulence factor of P. aeruginosa. The degradation of alginate by alginate lyases has come to serve as an adjunctive therapeutic strategy against P. aeruginosa biofilm, but poor stability of the enzyme limited this application. Thus, PspAlgL, an alginate lyase, can degrade acetylated alginate but has poor thermostability. The 3D structure of PspAlgL was predicted, and the thermostability of PspAlgL was rationally designed by GRAPE strategy, resulting in two variants with better stability. These variants, PspAlgLS270F/E311P and PspAlgLG291S/E311P, effectively degraded the alginate in biofilm. In addition, compared with PspAlgL, these variants were more efficient in inhibiting biofilm formation and degrading the established biofilm of P. aeruginosa PAO1, and they were also able to destroy the biofilm attached to catheters and to increase the sensitivity of P. aeruginosa to the antibiotic amikacin. This study provides one potential anti-biofilm agent for P. aeruginosa infection.},
}

@article {pmid38718953,
year = {2024},
author = {Divya, M and Chen, J and Durán-Lara, EF and Kim, KS and Sekar, V},
title = {Revolutionizing Healthcare: Harnessing Nano Biotechnology with Zinc Oxide Nanoparticles to combat Biofilm and Bacterial Infections-A Short Review.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {106679},
doi = {10.1016/j.micpath.2024.106679},
pmid = {38718953},
issn = {1096-1208},
abstract = {A crucial pathogenic mechanism in many bacterial diseases is the ability to create biofilms. Biofilms are suspected to play a role in over 80% of microbial illnesses in humans. In light of the critical requirement for efficient management of bacterial infections, researchers have explored alternative techniques for treating bacterial disorders. One of the most promising ways to address this issue is through the development of long-lasting coatings with antibacterial properties. In recent years, antibacterial treatments based on metallic nanoparticles (NPs) have emerged as an effective strategy in the fight over bacterial drug resistance. Zinc oxide nanoparticles (ZnO-NPs) are the basis of a new composite coating material. This article begins with a brief overview of the mechanisms that underlie bacterial resistance to antimicrobial drugs. A detailed examination of the properties of metallic nanoparticles (NPs) and their potential use as antibacterial drugs for curing drug-sensitive and resistant bacteria follows. Furthermore, we assess metal nanoparticles (NPs) as powerful agents to fight against antibiotic-resistant bacteria and the growth of biofilm, and we look into their potential toxicological effects for the development of future medicines.},
}

@article {pmid38718531,
year = {2024},
author = {Kang, S and Li, Q and Yang, Y and Lan, Y and Wang, X and Jiang, J and Han, M and Zhang, L and Wang, Q and Zhang, W},
title = {Effect of luminescent materials on the aquatic macrophyte Vallisneria natans and periphytic biofilm.},
journal = {Plant physiology and biochemistry : PPB},
volume = {211},
number = {},
pages = {108672},
doi = {10.1016/j.plaphy.2024.108672},
pmid = {38718531},
issn = {1873-2690},
abstract = {Luminescent materials can adjust the spectrum of light energy utilization by plants. However, current research on the effects of luminescent materials on aquatic plants and periphytic biofilms is limited. This study investigated the effects of the luminescent materials 4-(di-p-tolylamino) benzaldehyde-A (DTB-A) and 4-(di-p-tolylamino) benzaldehyde-M (DTB-M) on the submerged macrophyte Vallisneria natans (V. natans) and periphytic biofilm. Result demonstrated that low concentrations of DTB (0.1 μM) significantly promoted the growth and photosynthetic rate of V. natans. In terms of enzyme activity, exposure to a higher concentration of DTB (10 μM) increased the activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT). A combination of DTB-A and DTB-M treatment significantly changed the V. natans morphology and physiological characteristics, reducing the thickness of the cell wall and subsequently, promoting protein accumulation in leaves. There was no difference in the removal of ammonia or phosphate by V. natans at the 0.1 μM concentration, and the removal of ammonia and phosphate by V. natans decreased significantly as the concentration of luminescent material increased. A total of 3563 OTUs were identified in the biofilm community. The microbial community was dominated by Pseudomonas and Fusobacteria. Furthermore, results showed that an obvious decrease in diversity in the DTB-A and DTB-M mixed treatment group. In addition, the migratory aggregation of DTB molecules in plants was observed by fluorescence imaging. Overall, these findings extend our understanding of the mechanism of effect of luminescent materials on submerged macrophytes and their periphytic microorganisms.},
}

@article {pmid38718505,
year = {2024},
author = {Liu, S and Zhang, Z and Zhao, C and Zhang, M and Han, F and Hao, J and Wang, X and Shan, X and Zhou, W},
title = {Nonlinear responses of biofilm bacteria to alkyl-chain length of parabens by DFT calculation.},
journal = {Journal of hazardous materials},
volume = {472},
number = {},
pages = {134460},
doi = {10.1016/j.jhazmat.2024.134460},
pmid = {38718505},
issn = {1873-3336},
abstract = {Parabens can particularly raise significant concerns regarding the disruption of microbial ecology due to their antimicrobial properties. However, the responses of biofilm bacteria to diverse parabens with different alkyl-chain length remains unclear. Here, theoretical calculations and bioinformatic analysis were performed to decipher the influence of parabens varying alkyl-chain lengths on the biofilm bacteria. Our results showed that the disturbances in bacterial community did not linearly response to the alkyl-chain length of parabens, and propylparaben (PrP), with median chain length, had more severe impact on bacterial community. Despite the fact that paraben lethality linearly increased with chain length, the PrP had a higher chemical reactions potential than parabens with shorter or longer alkyl-chain. The chemical reactions potential was critical in the nonlinear responses of bacterial community to alkyl-chain length of parabens. PrP could impose selective pressure to disturb the bacterial community, because it had a more profound contribution to deterministic assembly process. Furthermore, N-acyl-homoserine lactones was also significantly promoted under PrP exposure, confirming that PrP could affect the bacterial community by influencing the quorum-sensing system. Overall, our study reveals the nonlinear responses of bacterial communities to the alkyl-chain lengths of parabens and provides insightful perspectives for the better regulation of parabens. ENVIRONMENTAL IMPLICATION: Parabens are recognized as emerging organic pollutants, which specially raise great concerns due to their antimicrobial properties disturbing microbial ecology. However, few study have addressed the relationship between bacterial community responses and the molecular structural features of parabens with different alkyl-chain length. This investigation revealed nonlinear responses of the bacterial community to the alkyl-chain length of parabens through DFT calculation and bioinformatic analysis and identified the critical roles of chemical reactions potential in nonlinear responses of bacterial community. Our results benefit the precise evaluation of ecological hazards posed by parabens and provide useful insights for better regulation of parabens.},
}

@article {pmid38718417,
year = {2024},
author = {Taşkın Kafa, AH and Aslan, R and Durna Daştan, S and Çeli K, C and Hasbek, M and Emi Noğlu, A},
title = {Molecular diversity of Klebsiella pneumoniae clinical isolates: antimicrobial resistance, virulence, and biofilm formation.},
journal = {Nucleosides, nucleotides & nucleic acids},
volume = {},
number = {},
pages = {1-17},
doi = {10.1080/15257770.2024.2344741},
pmid = {38718417},
issn = {1532-2335},
abstract = {One of the mechanisms responsible for antibiotic resistance in Klebsiella pneumoniae is the enzymes produced by the bacteria; another important mechanism is the ability to form biofilm. In this study, antibiotic resistance, genes associated with virulence, and biofilm-forming properties of K. pneumoniae strains were investigated. A total of 100 K. pneumoniae isolates were obtained from different clinical samples identified by Matrix-Assisted Laser Desorption/Ionization time-of-flight Mass Spectrometry. Antimicrobial susceptibility testing was performed with the Phoenix 100 apparatus. The biofilm forming properties of strains were determined by the microtiter plate method. For molecular analysis, genes encoding the carbapenemase enzyme (blaOXA-48, blaNDM-1, blaIMP, and blaVIM) and biofilm-related genes (treC, luxS, mrkA, and wza) were investigated by polymerase chain reaction (PCR). While 76% of clinical isolates were resistant to three or more antimicrobials, 24% were classified as non-multidrug resistant (non-MDR). When biofilm-forming capacities of clinical isolates were tested, it was determined that the resistant-isolates produced 59.2% strong biofilm, and susceptible-isolates produced 12.5% strong biofilm. According to PCR results, carbapenemase genes were determined as follows: blaOXA-48-70%, blaNDM-49%, and blaKPC-19%, blaOXA-48/blaNDM/blaKPC-12%, blaOXA-48/blaNDM-26%, and blaOXA-48/blaKPC-4%. The biofilm-associated genes in bacterial isolates were determined as follows: luxS-98%, treC-94%, mrkA-88%, and wza-15%. In addition, Hierarchical Clustering Tree and Heatmap analysis revealed an association between isolates that lacks resistance genes and isolates lacks biofilm-formation related genes that were included in MDR or non-MDR classes. As a result, biofilm should be considered in the treatment of MDR infections, and therapy should be planned accordingly. In addition, pursuing the data and genes of antibiotic resistance is significant for combating resistance.},
}

@article {pmid38717992,
year = {2024},
author = {Lencova, S and Stindlova, M and Havlickova, K and Jencova, V and Peroutka, V and Navratilova, K and Zdenkova, K and Stiborova, H and Hauzerova, S and Kostakova, EK and Jankovsky, O and Kejzlar, P and Lukas, D and Demnerova, K},
title = {Influence of Fiber Diameter of Polycaprolactone Nanofibrous Materials on Biofilm Formation and Retention of Bacterial Cells.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.4c03642},
pmid = {38717992},
issn = {1944-8252},
abstract = {To develop microbiologically safe nanofibrous materials, it is crucial to understand their interactions with microbial cells. Current research indicates that the morphology of nanofibers, particularly the diameter of the fibers, may play a significant role in biofilm formation and retention. However, it has not yet been determined how the fiber diameter of poly-ε-caprolactone (PCL), one of the most widely used biopolymers, affects these microbial interactions. In this study, two nanofibrous materials electrospun from PCL (PCL45 and PCL80) with different fiber diameter and characteristic distance δ between fibers were compared in terms of their ability to support or inhibit bacterial biofilm formation and retain bacterial cells. Strains of Escherichia coli (ATCC 25922 and ATCC 8739) and Staphylococcus aureus (ATCC 25923 and ATCC 6538) were used as model bacteria. Biofilm formation rate and retention varied significantly between the E. coli and S. aureus strains (p < 0.05) for the tested nanomaterials. In general, PCL showed a lower tendency to be colonized by the tested bacteria compared to the control material (polystyrene). Fiber diameter did not influence the biofilm formation rate of S. aureus strains and E. coli 25922 (p > 0.05), but it did significantly impact the biofilm formation rate of E. coli 8739 and biofilm morphology formed by all of the tested bacterial strains. In PCL45, thick uniform biofilm layers were formed preferably on the surface, while in PCL80 smaller clusters formed preferably inside the structure. Further, fiber diameter significantly influenced the retention of bacterial cells of all the tested strains (p < 0.001). PCL45, with thin fibers (average fiber diameter of 376 nm), retained up to 7 log (CFU mL[-1]) of staphylococcal cells (100% retention). The overall results indicate PCL45's potential for further research and highlight the nanofibers' morphology influence on bacterial interactions and differences in bacterial strains' behavior in the presence of nanomaterials.},
}

@article {pmid38717096,
year = {2024},
author = {Wang, Z and Zhang, X and Liu, Q and Hu, X and Mei, J and Zhou, J and Zhang, X and Xu, D and Zhu, W and Su, Z and Zhu, C},
title = {Balancing Bioresponsive Biofilm Eradication and Guided Tissue Repair via Pro-Efferocytosis and Bidirectional Pyroptosis Regulation during Implant Surgery.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.4c02157},
pmid = {38717096},
issn = {1936-086X},
abstract = {There is an increasingly growing demand to balance tissue repair guidance and opportunistic infection (OI) inhibition in clinical implant surgery. Herein, we developed a nanoadjuvant for all-stage tissue repair guidance and biofilm-responsive OI eradication via in situ incorporating Cobaltiprotoporphyrin (CoPP) into Prussian blue (PB) to prepare PB-CoPP nanozymes (PCZs). Released CoPP possesses a pro-efferocytosis effect for eliminating apoptotic and progressing necrotic cells in tissue trauma, thus preventing secondary inflammation. Once OIs occur, PCZs with switchable nanocatalytic capacity can achieve bidirectional pyroptosis regulation. Once reaching the acidic biofilm microenvironment, PCZs possess peroxidase (POD)-like activity that can generate reactive oxygen species (ROS) to eradicate bacterial biofilms, especially when synergized with the photothermal effect. Furthermore, generated ROS can promote macrophage pyroptosis to secrete inflammatory cytokines and antimicrobial proteins for biofilm eradication in vivo. After eradicating the biofilm, PCZs possess catalase (CAT)-like activity in a neutral environment, which can scavenge ROS and inhibit macrophage pyroptosis, thereby improving the inflammatory microenvironment. Briefly, PCZs as nanoadjuvants feature the capability of all-stage tissue repair guidance and biofilm-responsive OI inhibition that can be routinely performed in all implant surgeries, providing a wide range of application prospects and commercial translational value.},
}

@article {pmid38717093,
year = {2024},
author = {Hultqvist, LD and Andersen, JB and Nilsson, CM and Jansen, CU and Rybtke, M and Jakobsen, TH and Nielsen, TE and Qvortrup, K and Moser, C and Graz, M and Qvortrup, K and Tolker-Nielsen, T and Givskov, M},
title = {High efficacy treatment of murine Pseudomonas aeruginosa catheter-associated urinary tract infections using the c-di-GMP modulating anti-biofilm compound Disperazol in combination with ciprofloxacin.},
journal = {Antimicrobial agents and chemotherapy},
volume = {},
number = {},
pages = {e0148123},
doi = {10.1128/aac.01481-23},
pmid = {38717093},
issn = {1098-6596},
abstract = {Persistent urinary tract infections (UTIs) in hospitalized patients constitute an important medical problem. It is estimated that 75% of nosocomial UTIs are associated with urinary tract catheters with P. aeruginosa being a species that forms biofilms on these catheters. These infections are highly resistant to standard-of-care antibiotics, and the effects of the host immune defenses, which allows for development of persistent infections. With antibiotics losing their efficacy, new treatment options against resilient infections, such as catheter-associated urinary tract infections (CAUTIs), are critically needed. Central to our anti-biofilm approach is the manipulation of the c-di-GMP signaling pathway in P. aeruginosa to switch bacteria from the protective biofilm to the unprotected planktonic mode of life. We recently identified a compound (H6-335-P1), that stimulates the c-di-GMP degrading activity of the P. aeruginosa BifA protein which plummets the intracellular c-di-GMP content and induces dispersal of P. aeruginosa biofilm bacteria into the planktonic state. In the present study, we formulated H6-335-P1 as a hydrochloride salt (Disperazol), which is water-soluble and facilitates delivery via injection or oral administration. Disperazol can work as a monotherapy, but we observed a 100-fold improvement in efficacy when treating murine P. aeruginosa CAUTIs with a Disperazol/ciprofloxacin combination. Biologically active Disperazol reached the bladder 30 min after oral administration. Our study provides proof of concept that Disperazol can be used in combination with a relevant antibiotic for effective treatment of CAUTIs.},
}

@article {pmid38714243,
year = {2024},
author = {Miranda, ML and Danelon, M and Delbem, ACB and Kopp, W and Nunes, GP and Brighenti, FL},
title = {Enhanced Anti-Biofilm and Anti-Caries Potential of Arginine Combined with Calcium Glycerophosphate and Fluoride.},
journal = {Journal of dentistry},
volume = {},
number = {},
pages = {105039},
doi = {10.1016/j.jdent.2024.105039},
pmid = {38714243},
issn = {1879-176X},
abstract = {OBJECTIVE: The aim of this work was to evaluate the antibiofilm and anticaries properties of the association of arginine (Arg) with calcium glycerophosphate (CaGP) and fluoride (F).

METHODS: An active attachment, polymicrobial biofilm model obtained from saliva and bovine teeth discs were used. After the initial biofilm growth period, the enamel discs were transferred to culture medium. The treatment solutions were added to the culture media to achieve the desired final concentration. The following groups were used: negative control (Control); F (110 ppm F); CaGP (0.05%); Arg (0.8%) and their associations (F+CaGP; Arg+F; Arg+CaGP; Arg+F+CaGP). The following analyses were carried out: bacterial viability (total bacteria, aciduric bacteria and mutans streptococci), pH assessment of the spent culture medium, dry weight quantification, evaluation of surface hardness loss (%SH) and subsurface mineral content. Normality and homoscedasticity were tested (Shapiro-Wilk and Levene's test) and the following tests were applied: two-way ANOVA (acidogenicity), Kruskall-Wallis (microbial viability) and one way ANOVA (dry weight, %SH, mineral content).

RESULTS: The association Arg+F+CaGP resulted in the lowest surface hardness loss in tooth enamel (-10.9±2.3%; p<0.05). Arg+F+CaGP exhibited highest values of subsurface mineral content (10.1±2.9 gHAP/cm[3]) in comparison to Control and F (p<0.05). In comparison to Control and F, Arg+F+CaGP promoted the highest reduction in aciduric bacteria and mutans streptococci (5.7±0.4; 4.4±0.5 logCFU/mL, p<0.05).

CONCLUSIONS: The Arg-F-Ca association demonstrated to be the most effective combination in protecting the loss of surface hardness and subsurface mineral content, in addition to controlling important virulence factors of the cariogenic biofilm.

CLINICAL SIGNIFICANCE: Our findings provide evidence that the Arg-F-Ca association showed an additive effect, particularly concerning protection against enamel demineralization. The combination of these compounds may be a strategy for patients at high risk of caries.},
}

@article {pmid38713935,
year = {2024},
author = {Niu, C and Ying, Y and Zhao, J and Zheng, M and Guo, J and Yuan, Z and Hu, S and Liu, T},
title = {Superior mainstream partial nitritation in an acidic membrane-aerated biofilm reactor.},
journal = {Water research},
volume = {257},
number = {},
pages = {121692},
doi = {10.1016/j.watres.2024.121692},
pmid = {38713935},
issn = {1879-2448},
abstract = {Shortcut nitrogen removal holds significant economic appeal for mainstream wastewater treatment. Nevertheless, it is too difficult to achieve the stable suppression of nitrite-oxidizing bacteria (NOB), and simultaneously maintain the activity of ammonia-oxidizing bacteria (AOB). This study proposes to overcome this challenge by employing the novel acid-tolerant AOB, namely "Candidatus Nitrosoglobus", in a membrane-aerated biofilm reactor (MABR). Superior partial nitritation was demonstrated in low-strength wastewater from two aspects. First, the long-term operation (256 days) under the acidic pH range of 5.0 to 5.2 showed the successful NOB washout by the in situ free nitrous acid (FNA) of approximately 1 mg N/L. This was evidenced by the stable nitrite accumulation ratio (NAR) close to 100 % and the disappearance of NOB shown by 16S rRNA gene amplicon sequencing and fluorescence in situ hybridization. Second, oxygen was sufficiently supplied in the MABR, leading to an unprecedentedly high ammonia oxidation rate (AOR) at 2.4 ± 0.1 kg N/(m[3] d) at a short hydraulic retention time (HRT) of a mere 30 min. Due to the counter diffusion of substrates, the present acidic MABR displayed a significantly higher apparent oxygen affinity (0.36 ± 0.03 mg O2/L), a marginally lower apparent ammonia affinity (14.9 ± 1.9 mg N/L), and a heightened sensitivity to FNA and pH variations, compared with counterparts determined by flocculant acid-tolerant AOB. Beyond supporting the potential application of shortcut nitrogen removal in mainstream wastewater, this study also offers the attractive prospect of intensifying wastewater treatment by markedly reducing the HRT of the aerobic unit.},
}

@article {pmid38711646,
year = {2024},
author = {Lordelo, R and Branco, R and Gama, F and Morais, PV},
title = {Assessment of antimicrobial resistance, biofilm formation, and surface modification potential in hospital strains of Pseudomonas aeruginosa and Klebsiella pneumoniae.},
journal = {Heliyon},
volume = {10},
number = {9},
pages = {e30464},
pmid = {38711646},
issn = {2405-8440},
abstract = {The occurrence of healthcare-associated infections is a multifactorial phenomenon related to hospital space contamination by bacteria. The ESKAPE group, specifically Pseudomonas aeruginosa and Klebsiella pneumoniae, play a relevant role in the occurrence of these infections. Therefore, comprehensive research is needed to identify characteristics that justify the prevalence of these species in the healthcare environment. In this line, the study aimed to determine the antimicrobial resistance, biofilm formation, and the potential for polymer degradation in a collection of 33 P. aeruginosa strains and 2 K. pneumoniae strains sampled from various equipment and non-critical surfaces in a Portuguese hospital. Antimicrobial susceptibility tests revealed that none of the strains was categorized as multidrug-resistant (non-MDR). An assessment of their biofilm-forming capabilities indicated that 97 % of the strains exhibited biofilm-producing characteristics. Notably, within this group, the majority of P. aeruginosa and half of K. pneumoniae strains were classified as strong biofilm producers. Furthermore, the strains were evaluated for their potential to cause damage or change medical devices, namely infusion sets, nasal cannula, and urinary catheters. Three P. aeruginosa strains, two strong and one moderate biofilm producers, showed the highest ability to modify surfaces of the nasal cannula and infusion sets. Additionally, the Chi-square test revealed a statistically significant relationship between the presence of P. aeruginosa strains and the water accession spots. In conclusion, this work suggests that bacteria from this group hold a significant ability to grow in the healthcare environment through the degradation of non-critical materials. This suggests a potential concern for the persistence and proliferation of these organisms in hospital environments, emphasizing the importance of robust infection control measures to mitigate the risks associated with bacterial growth on such surfaces.},
}

@article {pmid38711289,
year = {2024},
author = {Cruz, PD and Wargowsky, R and Gonzalez-Almada, A and Sifontes, EP and Shaykhinurov, E and Jaatinen, K and Jepson, T and Lafleur, JE and Yamane, D and Perkins, J and Pasquale, M and Giang, B and McHarg, M and Falk, Z and McCaffrey, TA},
title = {Blood RNA Biomarkers Identify Bacterial and Biofilm Coinfections in COVID-19 Intensive Care Patients.},
journal = {Journal of intensive care medicine},
volume = {},
number = {},
pages = {8850666241251743},
doi = {10.1177/08850666241251743},
pmid = {38711289},
issn = {1525-1489},
abstract = {Purpose: Secondary opportunistic coinfections are a significant contributor to morbidity and mortality in intensive care unit (ICU) patients, but can be difficult to identify. Presently, new blood RNA biomarkers were tested in ICU patients to diagnose viral, bacterial, and biofilm coinfections. Methods: COVID-19 ICU patients had whole blood drawn in RNA preservative and stored at -80°C. Controls and subclinical infections were also studied. Droplet digital polymerase chain reaction (ddPCR) quantified 6 RNA biomarkers of host neutrophil activation to bacterial (DEFA1), biofilm (alkaline phosphatase [ALPL], IL8RB/CXCR2), and viral infections (IFI27, RSAD2). Viral titer in blood was measured by ddPCR for SARS-CoV2 (SCV2). Results: RNA biomarkers were elevated in ICU patients relative to controls. DEFA1 and ALPL RNA were significantly higher in severe versus incidental/moderate cases. SOFA score was correlated with white blood cell count (0.42), platelet count (-0.41), creatinine (0.38), and lactate dehydrogenase (0.31). ALPL RNA (0.59) showed the best correlation with SOFA score. IFI27 (0.52) and RSAD2 (0.38) were positively correlated with SCV2 viral titer. Overall, 57.8% of COVID-19 patients had a positive RNA biomarker for bacterial or biofilm infection. Conclusions: RNA biomarkers of host neutrophil activation indicate the presence of bacterial and biofilm coinfections in most COVID-19 patients. Recognizing coinfections may help to guide the treatment of ICU patients.},
}

@article {pmid38715287,
year = {2018},
author = {Johani, K and Hu, H and Santos, L and Schiller, S and Deva, AK and Whiteley, G and Almatroudi, A and Vickery, K},
title = {Determination of bacterial species present in biofilm contaminating the channels of clinical endoscopes.},
journal = {Infection, disease & health},
volume = {23},
number = {4},
pages = {189-196},
doi = {10.1016/j.idh.2018.06.003},
pmid = {38715287},
issn = {2468-0869},
abstract = {BACKGROUND: Outbreaks of endoscopy-related Carbapenem-resistant Enterobacteriaceae has highlighted failures in endoscope decontamination resulting in biofilm formation. Biofilms are tolerant to detergents and disinfectants. We evaluated decontaminated endoscope channels for residual bacterial contamination and biofilm presence.

METHODS: 64 channels were collected from 12 gastroscopes and 11 colonoscopes. Aerobic bacteria were isolated from inside the endoscope tubing by scrapping, sonication, and aerobic plate culture. Total number of contaminating bacteria was determined by quantitative real-time PCR with 16s rRNA eubacterial universal primers. Microbial diversity was assessed using next generation DNA sequencing. Biofilm presence was visually confirmed by confocal laser scanning and scanning electron microscopy.

RESULTS: 47% of channels were culture positive, with α-haemolytic Streptococci from gastroscopes and coliforms from colonoscopes the most frequently isolated species. Sphingomonas spp., Staphylococcus spp., Streptococcus spp., and Pseudomonas aeruginosa were also isolated. An average of 1.2 × 10[3] bacteria/cm contaminated air-water channels, 2.8 × 10[2] and 6.6 × 10[2] bacteria/cm contaminated gastroscope and colonoscope working channels, respectively. Biofilm was on all 39 channels examined and was principally composed of environmental bacteria, although all samples contained potential pathogens.

CONCLUSION: Biofilm is present on many endoscope channels obtained from Australian hospitals. Any soil including biofilm can compromise disinfectant action.},
}

@article {pmid38709077,
year = {2024},
author = {Poirier, S and Jean-Pierre, F},
title = {Growing a Cystic Fibrosis-Relevant Polymicrobial Biofilm to Probe Community Phenotypes.},
journal = {Journal of visualized experiments : JoVE},
volume = {},
number = {206},
pages = {},
doi = {10.3791/66785},
pmid = {38709077},
issn = {1940-087X},
mesh = {*Cystic Fibrosis/microbiology ; *Biofilms/growth & development ; Humans ; *Phenotype ; Pseudomonas aeruginosa/physiology ; Staphylococcus aureus/physiology/genetics ; Microbiota/physiology ; Streptococcus sanguis/physiology ; Prevotella melaninogenica/genetics ; },
abstract = {Most in vitro models lack the capacity to fully probe bacterial phenotypes emerging from the complex interactions observed in real-life environments. This is particularly true in the context of hard-to-treat, chronic, and polymicrobial biofilm-based infections detected in the airways of individuals living with cystic fibrosis (CF), a multiorgan genetic disease. While multiple microbiome studies have defined the microbial compositions detected in the airway of people with CF (pwCF), no in vitro models thus far have fully integrated critical CF-relevant lung features. Therefore, a significant knowledge gap exists in the capacity to investigate the mechanisms driving the pathogenesis of mixed species CF lung infections. Here, we describe a recently developed four-species microbial community model, including Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus sanguinis, and Prevotella melaninogenica grown in CF-like conditions. Through the utilization of this system, clinically relevant phenotypes such as antimicrobial recalcitrance of several pathogens were observed and explored at the molecular level. The usefulness of this in vitro model resides in its standardized workflow that can facilitate the study of interspecies interactions in the context of chronic CF lung infections.},
}

*Cystic Fibrosis/microbiology
*Biofilms/growth & development
Humans
*Phenotype
Pseudomonas aeruginosa/physiology
Staphylococcus aureus/physiology/genetics
Microbiota/physiology
Streptococcus sanguis/physiology
Prevotella melaninogenica/genetics

@article {pmid38708178,
year = {2024},
author = {Nafee, N and Gaber, DM and Abouelfetouh, A and Alseqely, M and Empting, M and Schneider, M},
title = {Enzyme-Linked Lipid Nanocarriers for Coping Pseudomonal Pulmonary Infection. Would Nanocarriers Complement Biofilm Disruption or Pave Its Road?.},
journal = {International journal of nanomedicine},
volume = {19},
number = {},
pages = {3861-3890},
pmid = {38708178},
issn = {1178-2013},
mesh = {*Biofilms/drug effects ; *Pseudomonas aeruginosa/drug effects/physiology ; Humans ; *Pseudomonas Infections/drug therapy ; *Nanoparticles/chemistry ; *Chitosan/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry/pharmacokinetics ; Drug Carriers/chemistry ; Cystic Fibrosis/drug therapy/microbiology ; Lipids/chemistry/pharmacology ; Quorum Sensing/drug effects ; A549 Cells ; Alginates/chemistry ; *Liposomes ; },
abstract = {INTRODUCTION: Cystic fibrosis (CF) is associated with pulmonary Pseudomonas aeruginosa infections persistent to antibiotics.

METHODS: To eradicate pseudomonal biofilms, solid lipid nanoparticles (SLNs) loaded with quorum-sensing-inhibitor (QSI, disrupting bacterial crosstalk), coated with chitosan (CS, improving internalization) and immobilized with alginate lyase (AL, destroying alginate biofilms) were developed.

RESULTS: SLNs (140-205 nm) showed prolonged release of QSI with no sign of acute toxicity to A549 and Calu-3 cells. The CS coating improved uptake, whereas immobilized-AL ensured >1.5-fold higher uptake and doubled SLN diffusion across the artificial biofilm sputum model. Respirable microparticles comprising SLNs in carbohydrate matrix elicited aerodynamic diameters MMAD (3.54, 2.48 µm) and fine-particle-fraction FPF (65, 48%) for anionic and cationic SLNs, respectively. The antimicrobial and/or antibiofilm activity of SLNs was explored in Pseudomonas aeruginosa reference mucoid/nonmucoid strains as well as clinical isolates. The full growth inhibition of planktonic bacteria was dependent on SLN type, concentration, growth medium, and strain. OD measurements and live/dead staining proved that anionic SLNs efficiently ceased biofilm formation and eradicated established biofilms, whereas cationic SLNs unexpectedly promoted biofilm progression. AL immobilization increased biofilm vulnerability; instead, CS coating increased biofilm formation confirmed by 3D-time lapse confocal imaging. Incubation of SLNs with mature biofilms of P. aeruginosa isolates increased biofilm density by an average of 1.5-fold. CLSM further confirmed the binding and uptake of the labeled SLNs in P. aeruginosa biofilms. Considerable uptake of CS-coated SLNs in non-mucoid strains could be observed presumably due to interaction of chitosan with LPS glycolipids in the outer cell membrane of P. aeruginosa.

CONCLUSION: The biofilm-destructive potential of QSI/SLNs/AL inhalation is promising for site-specific biofilm-targeted interventional CF therapy. Nevertheless, the intrinsic/extrinsic fundamentals of nanocarrier-biofilm interactions require further investigation.},
}

*Biofilms/drug effects
*Pseudomonas aeruginosa/drug effects/physiology
Humans
*Pseudomonas Infections/drug therapy
*Nanoparticles/chemistry
*Chitosan/chemistry
*Anti-Bacterial Agents/pharmacology/chemistry/pharmacokinetics
Drug Carriers/chemistry
Cystic Fibrosis/drug therapy/microbiology
Lipids/chemistry/pharmacology
Quorum Sensing/drug effects
A549 Cells
Alginates/chemistry
*Liposomes

@article {pmid38706985,
year = {2024},
author = {Huijboom, L and Rashtchi, P and Tempelaars, M and Boeren, S and van der Linden, E and Habibi, M and Abee, T},
title = {Phenotypic and proteomic differences in biofilm formation of two Lactiplantibacillus plantarum strains in static and dynamic flow environments.},
journal = {Biofilm},
volume = {7},
number = {},
pages = {100197},
pmid = {38706985},
issn = {2590-2075},
abstract = {Lactiplantibacillus plantarum is a Gram-positive non-motile bacterium capable of producing biofilms that contribute to the colonization of surfaces in a range of different environments. In this study, we compared two strains, WCFS1 and CIP104448, in their ability to produce biofilms in static and dynamic (flow) environments using an in-house designed flow setup. This flow setup enables us to impose a non-uniform flow velocity profile across the well. Biofilm formation occurred at the bottom of the well for both strains, under static and flow conditions, where in the latter condition, CIP104448 also showed increased biofilm formation at the walls of the well in line with the higher hydrophobicity of the cells and the increased initial attachment efficacy compared to WCFS1. Fluorescence and scanning electron microscopy showed open 3D structured biofilms formed under flow conditions, containing live cells and ∼30 % damaged/dead cells for CIP104448, whereas the WCFS1 biofilm showed live cells closely packed together. Comparative proteome analysis revealed minimal changes between planktonic and static biofilm cells of the respective strains suggesting that biofilm formation within 24 h is merely a passive process. Notably, observed proteome changes in WCFS1 and CIP104448 flow biofilm cells indicated similar and unique responses including changes in metabolic activity, redox/electron transfer and cell division proteins for both strains, and myo-inositol production for WCFS1 and oxidative stress response and DNA damage repair for CIP104448 uniquely. Exposure to DNase and protease treatments as well as lethal concentrations of peracetic acid showed highest resistance of flow biofilms. For the latter, CIP104448 flow biofilm even maintained its high disinfectant resistance after dispersal from the bottom and from the walls of the well. Combining all results highlights that L. plantarum biofilm structure and matrix, and physiological state and stress resistance of cells is strain dependent and strongly affected under flow conditions. It is concluded that consideration of effects of flow on biofilm formation is essential to better understand biofilm formation in different settings, including food processing environments.},
}

@article {pmid38706006,
year = {2024},
author = {Liew, KJ and Shahar, S and Shamsir, MS and Shaharuddin, NB and Liang, CH and Chan, KG and Pointing, SB and Sani, RK and Goh, KM},
title = {Integrating multi-platform assembly to recover MAGs from hot spring biofilms: insights into microbial diversity, biofilm formation, and carbohydrate degradation.},
journal = {Environmental microbiome},
volume = {19},
number = {1},
pages = {29},
pmid = {38706006},
issn = {2524-6372},
support = {FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; FRGS/1/2023/STG02/UTM/02/1, FRGS/1/2019/STG03/UTM/02/1, FRGS/1/2019/STG04/UTM/02/4//Malaysia Fundamental Research Grant Scheme (FRGS)/ ; 4J549//UTM QuickWin grant/ ; 4J549//UTM QuickWin grant/ ; T2EP30123-0028//Singapore Ministry of Education ARC Tier 2 fund/ ; 1736255, 1849206, and 1920954//National Science Foundation/ ; },
abstract = {BACKGROUND: Hot spring biofilms provide a window into the survival strategies of microbial communities in extreme environments and offer potential for biotechnological applications. This study focused on green and brown biofilms thriving on submerged plant litter within the Sungai Klah hot spring in Malaysia, characterised by temperatures of 58-74 °C. Using Illumina shotgun metagenomics and Nanopore ligation sequencing, we investigated the microbial diversity and functional potential of metagenome-assembled genomes (MAGs) with specific focus on biofilm formation, heat stress response, and carbohydrate catabolism.

RESULTS: Leveraging the power of both Illumina short-reads and Nanopore long-reads, we employed an Illumina-Nanopore hybrid assembly approach to construct MAGs with enhanced quality. The dereplication process, facilitated by the dRep tool, validated the efficiency of the hybrid assembly, yielding MAGs that reflected the intricate microbial diversity of these extreme ecosystems. The comprehensive analysis of these MAGs uncovered intriguing insights into the survival strategies of thermophilic taxa in the hot spring biofilms. Moreover, we examined the plant litter degradation potential within the biofilms, shedding light on the participation of diverse microbial taxa in the breakdown of starch, cellulose, and hemicellulose. We highlight that Chloroflexota and Armatimonadota MAGs exhibited a wide array of glycosyl hydrolases targeting various carbohydrate substrates, underscoring their metabolic versatility in utilisation of carbohydrates at elevated temperatures.

CONCLUSIONS: This study advances understanding of microbial ecology on plant litter under elevated temperature by revealing the functional adaptation of MAGs from hot spring biofilms. In addition, our findings highlight potential for biotechnology application through identification of thermophilic lignocellulose-degrading enzymes. By demonstrating the efficiency of hybrid assembly utilising Illumina-Nanopore reads, we highlight the value of combining multiple sequencing methods for a more thorough exploration of complex microbial communities.},
}

@article {pmid38705960,
year = {2024},
author = {Kanwar, K and Sharma, D and Singh, H and Pal, M and Bandhu, R and Azmi, W},
title = {In vitro effects of alginate lyase SG4 + produced by Paenibacillus lautus alone and combined with antibiotics on biofilm formation by mucoid Pseudomonas aeruginosa.},
journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]},
volume = {},
number = {},
pages = {},
pmid = {38705960},
issn = {1678-4405},
abstract = {Alginate is a major extra polymeric substance in the biofilm formed by mucoid Pseudomonas aeruginosa. It is the main proven perpetrator of lung infections in patients suffering from cystic fibrosis. Alginate lyases are very important in the treatment of cystic fibrosis. This study evaluated the role of standalone and in conjugation, effect of alginate lyase of SG4 + isolated from Paenibacillus lautus in enhancing in vitro bactericidal activity of gentamicin and amikacin on mucoid P. aeruginosa. Using Response Surface Methodology (RSM) alginate lyase SG4 + production was optimized in shake flask and there 8.49-fold enhancement in enzyme production. In fermenter, maximum growth (10.15 mg/ml) and alginate lyase (1.46 International Units) production, 1.71-fold was increased using Central Composite Design (CCD). Further, fermentation time was reduced from 48 to 20 h. To the best of our knowledge this is the first report in which CCD was used for fermenter studies to optimize alginate lyase production. The Km and Vmax of purified enzyme were found to be 2.7 mg/ml and 0.84 mol/ml-min, respectively. The half-life (t 1/2) of purified alginate lyase SG4 + at 37 °C was 180 min. Alginate lyase SG4 + in combination with gentamicin and amikacin eradiated 48.4- 52.3% and 58- 64.6%, alginate biofilm formed by P. aeruginosa strains, respectively. The study proves that alginate lyase SG4 + has excellent exopolysaccharide disintegrating ability and may be useful in development of potent therapeutic agent to treat P. aeruginosa biofilms.},
}

@article {pmid38704559,
year = {2024},
author = {Esfandiary, MA and Khosravi, AR and Asadi, S and Nikaein, D and Hassan, J and Sharifzadeh, A},
title = {Antimicrobial and anti-biofilm properties of oleuropein against Escherichia coli and fluconazole-resistant isolates of Candida albicans and Candida glabrata.},
journal = {BMC microbiology},
volume = {24},
number = {1},
pages = {154},
pmid = {38704559},
issn = {1471-2180},
mesh = {*Biofilms/drug effects/growth & development ; *Iridoid Glucosides/pharmacology ; *Microbial Sensitivity Tests ; *Candida glabrata/drug effects/physiology/genetics ; *Candida albicans/drug effects/genetics/physiology ; *Escherichia coli/drug effects/genetics ; *Iridoids/pharmacology ; *Fluconazole/pharmacology ; *Antifungal Agents/pharmacology ; Drug Resistance, Fungal ; Anti-Bacterial Agents/pharmacology ; Microscopy, Electron, Scanning ; },
abstract = {BACKGROUND: Side effects associated with antimicrobial drugs, as well as their high cost, have prompted a search for low-cost herbal medicinal substances with fewer side effects. These substances can be used as supplements to medicine or to strengthen their effects. The current study investigated the effect of oleuropein on the inhibition of fungal and bacterial biofilm in-vitro and at the molecular level.

MATERIALS AND METHODS: In this experimental study, antimicrobial properties were evaluated using microbroth dilution method. The effect of oleuropein on the formation and eradication of biofilm was assessed on 96-well flat bottom microtiter plates and their effects were observed through scanning electron microscopy (SEM). Its effect on key genes (Hwp1, Als3, Epa1, Epa6, LuxS, Pfs) involved in biofilm formation was investigated using the quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) method.

RESULTS: The minimum inhibitory concentration (MIC) and minimum fungicidal/bactericidal concentration (MFC/MBC) for oleuropein were found to be 65 mg/ml and 130 mg/ml, respectively. Oleuropein significantly inhibited biofilm formation at MIC/2 (32.5 mg/ml), MIC/4 (16.25 mg/ml), MIC/8 (8.125 mg/ml) and MIC/16 (4.062 mg/ml) (p < 0.0001). The anti-biofilm effect of oleuropein was confirmed by SEM. RT-qPCR indicated significant down regulation of expression genes involved in biofilm formation in Candida albicans (Hwp1, Als3) and Candida glabrata (Epa1, Epa6) as well as Escherichia coli (LuxS, Pfs) genes after culture with a MIC/2 of oleuropein (p < 0.0001).

CONCLUSIONS: The results indicate that oleuropein has antifungal and antibacterial properties that enable it to inhibit or destroy the formation of fungal and bacterial biofilm.},
}

*Biofilms/drug effects/growth & development
*Iridoid Glucosides/pharmacology
*Microbial Sensitivity Tests
*Candida glabrata/drug effects/physiology/genetics
*Candida albicans/drug effects/genetics/physiology
*Escherichia coli/drug effects/genetics
*Iridoids/pharmacology
*Fluconazole/pharmacology
*Antifungal Agents/pharmacology
Drug Resistance, Fungal
Anti-Bacterial Agents/pharmacology
Microscopy, Electron, Scanning

@article {pmid38703685,
year = {2024},
author = {Wang, H and Zhou, Q},
title = {Bioelectrochemical anaerobic digestion mitigates microplastic pollution and promotes methane recovery of wastewater treatment in biofilm system.},
journal = {Journal of hazardous materials},
volume = {472},
number = {},
pages = {134488},
doi = {10.1016/j.jhazmat.2024.134488},
pmid = {38703685},
issn = {1873-3336},
abstract = {Bioelectrochemical systems (BES) offer significant potential for treating refractory waste and recovering bioenergy. However, their ability to mitigate microplastic pollution in wastewater remains unexplored. This study showed that BES facilitated the treatment of polyethylene (PE), polyvinyl chloride (PVC), and Mix (PE+PVC) microplastic wastewater and the methane recovery (40.61%, 20.02%, 21.19%, respectively). The lactate dehydrogenase (LDH), adenosine triphosphate (ATP), cytochrome c, and nicotinamide adenine dinucleotide (NADH/NAD+) ratios were elevated with electrical stimulation. Moreover, the applied voltage improved the polysaccharides content of the extracellular polymeric substances (EPS) in the PE-BES but decreased in PVC-BES, while the proteins showed the opposite trend. Metatranscriptomic sequencing showed that the abundance of fermentation bacteria, acetogens, electrogens, and methanogens was greatly enhanced by applying voltage, especially at the anode. Methane metabolism was dominated by the acetoclastic methanogenic pathway, with the applied voltage promoting the enrichment of Methanothrix, resulting in the direct conversion of acetate to acetyl-CoA via acetate-CoA ligase (EC: 6.2.1.1), and increased metabolic activity in the anode. Moreover, applied voltage greatly boosted the function genes expression level related to energy metabolism, tricarboxylic acid (TCA) cycle, electron transport, and transporters on the anode biofilm. Overall, these results demonstrate that BES can mitigate microplastic pollution during wastewater treatment.},
}

@article {pmid38703635,
year = {2024},
author = {Kwiecińska-Piróg, J and Chomont, K and Fydrych, D and Stawarz, J and Bogiel, T and Przekwas, J and Gospodarek-Komkowska, E},
title = {How xylitol, gluten, and lactose change human gut microbiota Escherichia coli and Lactobacillus rhamnosus GG biofilm.},
journal = {Nutrition (Burbank, Los Angeles County, Calif.)},
volume = {124},
number = {},
pages = {112446},
doi = {10.1016/j.nut.2024.112446},
pmid = {38703635},
issn = {1873-1244},
abstract = {OBJECTIVE: The human gut microbiota is composed of many viruses, bacteria, and fungi. Escherichia coli representatives are facultative anaerobic bacteria in the colon that play a crucial role in the metabolism of lactose, vitamin synthesis, and immune system modulation. E. coli forms a biofilm on the epithelial cell surface of the intestine that can be modified by diet compounds, i.e., gluten, xylitol, lactose, and probiotics.

METHODS: In the present study, the impact of probiotic-derived Lactobacillus rhamnosus GG strain on non-pathogenic E. coli biofilm was examined. The mono- and multispecies biofilm was also treated with gluten, xylitol, and lactose. We used 96-well plates to obtain biofilm growth. Biofilm was stained using crystal violet. To evaluate the type of interaction in mono- and multispecies biofilm, a new formula was introduced: biofilm interaction ratio index (BIRI). To describe the impact of nutrients on biofilm formation, the biofilm formation impact ratio (BFIR) was calculated.

RESULTS: The biofilms formed by both examined species are stronger than in monocultures. All the BIRI values were above 3.0. It was found that the monospecies biofilm of L. rhamnosus is strongly inhibited by gluten (84.5%) and the monospecies biofilm of E. coli by xylitol (85.5%). The mixed biofilm is inhibited by lactose (78.8%) and gluten (90.6%).

CONCLUSION: The relations between bacteria in the mixed biofilm led to changes in biofilm formation by E. coli and L. rhamnosus GG. Probiotics might be helpful in rebuilding the gut microbiota after broad spectrum antibiotic therapy, but only if gluten and lactose are excluded from diet.},
}

@article {pmid38702839,
year = {2024},
author = {Paulino, S and Petek, S and le Strat, Y and Bourgougnon, N and Le Blay, G},
title = {Cultivable epiphytic bacteria of the Chlorophyta Ulva sp. : diversity, antibacterial and biofilm-modulating activities.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/jambio/lxae099},
pmid = {38702839},
issn = {1365-2672},
abstract = {AIMS: Macroalgae harbor a rich epiphytic microbiota that plays a crucial role in algal morphogenesis and defense mechanisms. This study aims to isolate epiphytic cultivable microbiota from Ulva sp. surfaces. Various culture media were employed to evaluate a wide range of cultivable microbiota. Our objective was to assess the antibacterial and biofilm-modulating activities of supernatants from isolated bacteria.

METHODS AND RESULTS: 69 bacterial isolates from Ulva sp. were identified based on 16S rRNA gene sequencing. Their antibacterial activity and biofilm modulation potential were screened against three target marine bacteria : 45%, mostly affiliated with Gammaproteobacteria and mainly grown on diluted R2A medium (R2Ad), showed strong antibacterial activity while 18% had a significant impact on biofilm modulation. Molecular network analysis was carried out on four bioactive bacterial supernatants, revealing new molecules potentially responsible for their activities.

CONCLUSION: R2Ad offered the greatest diversity and proportion of active isolates. The molecular network approach holds promise for both identifying bacterial isolates based on their molecular production and characterizing antibacterial and biofilm-modulating activities.},
}

@article {pmid38702622,
year = {2024},
author = {Alabssawy, AN and Abu-Elghait, M and Azab, AM and Khalaf-Allah, HMM and Ashry, AS and Ali, AOM and Sabra, AAA and Salem, SS},
title = {Hindering the biofilm of microbial pathogens and cancer cell lines development using silver nanoparticles synthesized by epidermal mucus proteins from Clarias gariepinus.},
journal = {BMC biotechnology},
volume = {24},
number = {1},
pages = {28},
pmid = {38702622},
issn = {1472-6750},
mesh = {*Metal Nanoparticles/chemistry ; *Biofilms/drug effects/growth & development ; *Silver/chemistry/pharmacology ; Animals ; Humans ; *Catfishes ; Mucus/metabolism ; Antineoplastic Agents/pharmacology/chemistry ; Vero Cells ; Fish Proteins/pharmacology/chemistry/metabolism ; Chlorocebus aethiops ; Cell Line, Tumor ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa/drug effects ; Anti-Infective Agents/pharmacology/chemistry ; Staphylococcus aureus/drug effects/physiology ; Candida albicans/drug effects ; Epidermis/metabolism ; },
abstract = {Scientists know very little about the mechanisms underlying fish skin mucus, despite the fact that it is a component of the immune system. Fish skin mucus is an important component of defence against invasive infections. Recently, Fish skin and its mucus are gaining interest among immunologists. Characterization was done on the obtained silver nanoparticles Ag combined with Clarias gariepinus catfish epidermal mucus proteins (EMP-Ag-NPs) through UV-vis, FTIR, XRD, TEM, and SEM. Ag-NPs ranged in size from 4 to 20 nm, spherical in form and the angles were 38.10°, 44.20°, 64.40°, and 77.20°, Where wavelength change after formation of EMP-Ag-NPs as indicate of dark brown, the broad band recorded at wavelength at 391 nm. Additionally, the antimicrobial, antibiofilm and anticancer activities of EMP-Ag-NPs was assessed. The present results demonstrate high activity against unicellular fungi C. albicans, followed by E. faecalis. Antibiofilm results showed strong activity against both S. aureus and P. aeruginosa pathogens in a dose-dependent manner, without affecting planktonic cell growth. Also, cytotoxicity effect was investigated against normal cells (Vero), breast cancer cells (Mcf7) and hepatic carcinoma (HepG2) cell lines at concentrations (200-6.25 µg/mL) and current results showed highly anticancer effect of Ag-NPs at concentrations 100, 5 and 25 µg/mL exhibited rounding, shrinkage, deformation and granulation of Mcf7 and HepG2 with IC50 19.34 and 31.16 µg/mL respectively while Vero cells appeared rounded at concentration 50 µg/mL and normal shape at concentration 25, 12.5 and 6.25 µg/ml with IC50 35.85 µg/mL. This study evidence the potential efficacy of biologically generated Ag-NPs as a substitute medicinal agent against harmful microorganisms. Furthermore, it highlights their inhibitory effect on cancer cell lines.},
}

*Metal Nanoparticles/chemistry
*Biofilms/drug effects/growth & development
*Silver/chemistry/pharmacology
Animals
Humans
*Catfishes
Mucus/metabolism
Antineoplastic Agents/pharmacology/chemistry
Vero Cells
Fish Proteins/pharmacology/chemistry/metabolism
Chlorocebus aethiops
Cell Line, Tumor
Microbial Sensitivity Tests
Pseudomonas aeruginosa/drug effects
Anti-Infective Agents/pharmacology/chemistry
Staphylococcus aureus/drug effects/physiology
Candida albicans/drug effects
Epidermis/metabolism

@article {pmid38702575,
year = {2024},
author = {Pandey, P and Vavilala, SL},
title = {From Gene Editing to Biofilm Busting: CRISPR-CAS9 Against Antibiotic Resistance-A Review.},
journal = {Cell biochemistry and biophysics},
volume = {},
number = {},
pages = {},
pmid = {38702575},
issn = {1559-0283},
abstract = {In recent decades, the development of novel antimicrobials has significantly slowed due to the emergence of antimicrobial resistance (AMR), intensifying the global struggle against infectious diseases. Microbial populations worldwide rapidly develop resistance due to the widespread use of antibiotics, primarily targeting drug-resistant germs. A prominent manifestation of this resistance is the formation of biofilms, where bacteria create protective layers using signaling pathways such as quorum sensing. In response to this challenge, the CRISPR-Cas9 method has emerged as a ground-breaking strategy to counter biofilms. Initially identified as the "adaptive immune system" of bacteria, CRISPR-Cas9 has evolved into a state-of-the-art genetic engineering tool. Its exceptional precision in altering specific genes across diverse microorganisms positions it as a promising alternative for addressing antibiotic resistance by selectively modifying genes in diverse microorganisms. This comprehensive review concentrates on the historical background, discovery, developmental stages, and distinct components of CRISPR Cas9 technology. Emphasizing its role as a widely used genome engineering tool, the review explores how CRISPR Cas9 can significantly contribute to the targeted disruption of genes responsible for biofilm formation, highlighting its pivotal role in reshaping strategies to combat antibiotic resistance and mitigate the challenges posed by biofilm-associated infectious diseases.},
}

@article {pmid38701663,
year = {2024},
author = {Zibar Belasic, T and Badnjevic, M and Zigante, M and Mohar Vitezic, B and Spalj, S and Markova-Car, EP},
title = {Supragingival dental biofilm profile and biofilm control during orthodontic treatment with fixed orthodontic appliance: A randomized controlled trial.},
journal = {Archives of oral biology},
volume = {164},
number = {},
pages = {105984},
doi = {10.1016/j.archoralbio.2024.105984},
pmid = {38701663},
issn = {1879-1506},
abstract = {OBJECTIVE: The effectiveness of supragingival dental biofilm control during orthodontic treatment and changes in the bacterial profile were analyzed.

DESIGN: Sixty-four participants aged 12-22 years (57% female) were included in the study. Participants underwent orthodontic treatment with fixed appliances and were randomly assigned to one of the three groups, which during a period of one month: (I) used chlorhexidine digluconate (CHX), (II) used high concentration of fluoride (F) gel and (III) performed standard oral hygiene. The plaque and gingivitis index, pH of biofilm and white spot lesions (WSL) were assessed. Changes of the bacteria in the biofilm were analyzed by the quantitative polymerase chain reaction RESULTS: Increase in the plaque index, pH of biofilm, and WSL was observed during orthodontic treatment with standard oral hygiene. Large interindividual variability was present, and the effects of one-month use of fluorides and CHX on clinical parameters were not significant. Despite standard hygiene the abundance of studied biofilm bacteria increased - the most Streptoccocus mutans (14.2x) and S. salivarius (3.3x), moderate Veillonella parvula (3x) and the least S. sobrinus (2.3x) and Agregatibacter actinomycetemcomitans (1.9x). The use of CHX reduced S. sobrinus (2.2x) and A. actinomycetemcomitans (1.9x). Fluoride use reduced A. actinomycetemcomitans (1.3x) and S. sobrinus (1.2x). Fluorides better controlled S. mutans than CHX.

CONCLUSION: Bacterial biomass in supragingival biofilm increased during treatment with metal orthodontic appliances, with greater increase in cariogenic bacteria than periopathogens. Fluoride controlled S. mutans, while CHX S. sobrinus and A. actinomycetemcomitans.},
}

@article {pmid38700735,
year = {2024},
author = {Polat, T and Soyhan, İ and Cebeci, S and İldeniz, TAÖ and Gök, Ö and Elmas, MA and Mozioğlu, E and Ünübol, N},
title = {New-generation biofilm effective antimicrobial peptides and a real-time anti-biofilm activity assay: CoMIC.},
journal = {Applied microbiology and biotechnology},
volume = {108},
number = {1},
pages = {316},
pmid = {38700735},
issn = {1432-0614},
mesh = {*Biofilms/drug effects ; *Antimicrobial Peptides/pharmacology/chemistry ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology/chemistry ; Models, Molecular ; Microscopy, Electron, Scanning ; Bacteria/drug effects ; },
abstract = {Nowadays, it is very important to produce new-generation drugs with antimicrobial properties that will target biofilm-induced infections. The first target for combating these microorganisms, which are the source itself. Antimicrobial peptides, which are more effective than antibiotics due to their ability to kill microorganisms and use a different metabolic pathway, are among the new options today. The aim of this study is to develop new-generation antibiotics that inhibit both biofilm-producing bacteria and the biofilm itself. For this purpose, we designed four different peptides by combining two amino acid forms (D- and L-) with the same sequence having alpha helix structures. It was found that the combined use of these two forms can increase antimicrobial efficacy more than 30-fold. These results are supported by molecular modeling and scanning electron microscopy (SEM), at the same time cytotoxicity (IC50) and hemotoxicity (HC50) values remained within the safe range. Furthermore, antibiofilm activities of these peptides were investigated. Since the existing biofilm inhibition methods in the literature do not technically simulate the exact situation, in this study, we have developed a real-time observable biofilm model and a new detection method based on it, which we call the CoMIC method. Findings have shown that the NET1 peptide with D-leucine amino acid in its structure and the NET3 peptide with D-arginine amino acid in its structure are effective in inhibiting biofilm. As a conclusion, our peptides can be considered as potential next-generation broad-spectrum antibiotic molecule/drug candidates that might be used in biofilm and clinical important bacteria. KEY POINTS: • Antimicrobial peptides were developed to inhibit both biofilms producing bacteria and the biofilm itself. • CoMIC will fill a very crucial gap in understanding biofilms and conducting the necessary quantitative studies. • Molecular modelling studies, NET1 peptide molecules tends to move towards and adhere to the membrane within nanoseconds.},
}

*Biofilms/drug effects
*Antimicrobial Peptides/pharmacology/chemistry
*Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology/chemistry
Models, Molecular
Microscopy, Electron, Scanning
Bacteria/drug effects

@article {pmid38700325,
year = {2024},
author = {Liu, X and Lertsethtakarn, P and Mariscal, VT and Yildiz, F and Ottemann, KM},
title = {Counterclockwise rotation of the flagellum promotes biofilm initiation in Helicobacter pylori.},
journal = {mBio},
volume = {},
number = {},
pages = {e0044024},
doi = {10.1128/mbio.00440-24},
pmid = {38700325},
issn = {2150-7511},
abstract = {UNLABELLED: Motility promotes biofilm initiation during the early steps of this process: microbial surface association and attachment. Motility is controlled in part by chemotaxis signaling, so it seems reasonable that chemotaxis may also affect biofilm formation. There is a gap, however, in our understanding of the interactions between chemotaxis and biofilm formation, partly because most studies analyzed the phenotype of only a single chemotaxis signaling mutant, e.g., cheA. Here, we addressed the role of chemotaxis in biofilm formation using a full set of chemotaxis signaling mutants in Helicobacter pylori, a class I carcinogen that infects more than half the world's population and forms biofilms. Using mutants that lack each chemotaxis signaling protein, we found that chemotaxis signaling affected the biofilm initiation stage, but not mature biofilm formation. Surprisingly, some chemotaxis mutants elevated biofilm initiation, while others inhibited it in a manner that was not tied to chemotaxis ability or ligand input. Instead, the biofilm phenotype correlated with flagellar rotational bias. Specifically, mutants with a counterclockwise bias promoted biofilm initiation, e.g., ∆cheA, ∆cheW, or ∆cheV1; in contrast, those with a clockwise bias inhibited it, e.g., ∆cheZ, ∆chePep, or ∆cheV3. We tested this correlation using a counterclockwise bias-locked flagellum, which induced biofilm formation independent of the chemotaxis system. These CCW flagella, however, were not sufficient to induce biofilm formation, suggesting there are downstream players. Overall, our work highlights the new finding that flagellar rotational direction promotes biofilm initiation, with the chemotaxis signaling system operating as one mechanism to control flagellar rotation.

IMPORTANCE: Chemotaxis signaling systems have been reported to contribute to biofilm formation in many bacteria; however, how they regulate biofilm formation remains largely unknown. Chemotaxis systems are composed of many distinct kinds of proteins, but most previous work analyzed the biofilm effect of loss of only a few. Here, we explored chemotaxis' role during biofilm formation in the human-associated pathogenic bacterium Helicobacter pylori. We found that chemotaxis proteins are involved in biofilm initiation in a manner that correlated with how they affected flagellar rotation. Biofilm initiation was high in mutants with counterclockwise (CCW) flagellar bias and low in those with clockwise bias. We supported the idea that a major driver of biofilm formation is flagellar rotational direction using a CCW-locked flagellar mutant, which stays CCW independent of chemotaxis input and showed elevated biofilm initiation. Our data suggest that CCW-rotating flagella, independent of chemotaxis inputs, are a biofilm-promoting signal.},
}

@article {pmid38698252,
year = {2024},
author = {Berto, LA and Ettmayer, JB and Stutzer, D and Nietzsche, S and Niederhauser, T and Burger, J and Sculean, A and Eick, S and Hofmann, M},
title = {In-vitro effects of novel periodontal scalers with a planar ultrasonic piezoelectric transducer on periodontal biofilm removal, dentine surface roughness, and periodontal ligament fibroblasts adhesion.},
journal = {Clinical oral investigations},
volume = {28},
number = {5},
pages = {294},
pmid = {38698252},
issn = {1436-3771},
mesh = {*Biofilms ; *Fibroblasts ; Humans ; *Surface Properties ; *Titanium ; *Dental Scaling/instrumentation ; In Vitro Techniques ; *Dentin/microbiology ; *Periodontal Ligament/cytology ; Transducers ; Cell Adhesion ; Stainless Steel ; Equipment Design ; Ultrasonic Therapy/instrumentation ; },
abstract = {OBJECTIVES: To compare ultrasonic scaler prototypes based on a planar piezoelectric transducer with different working frequencies featuring a titanium (Ti-20, Ti-28, and Ti-40) or stainless steel (SS-28) instrument, with a commercially available scaler (com-29) in terms of biofilm removal and reformation, dentine surface roughness and adhesion of periodontal fibroblasts.

MATERIALS AND METHODS: A periodontal multi-species biofilm was formed on specimens with dentine slices. Thereafter specimens were instrumented with scalers in a periodontal pocket model or left untreated (control). The remaining biofilms were quantified and allowed to reform on instrumented dentine slices. In addition, fibroblasts were seeded for attachment evaluation after 72 h of incubation. Dentine surface roughness was analyzed before and after instrumentation.

RESULTS: All tested instruments reduced the colony-forming unit (cfu) counts by about 3 to 4 log10 and the biofilm quantity (each p < 0.01 vs. control), but with no statistically significant difference between the instrumented groups. After 24-hour biofilm reformation, no differences in cfu counts were observed between any groups, but the biofilm quantity was about 50% in all instrumented groups compared to the control. The attachment of fibroblasts on instrumented dentine was significantly higher than on untreated dentine (p < 0.05), with the exception of Ti-20. The dentine surface roughness was not affected by any instrumentation.

CONCLUSIONS: The planar piezoelectric scaler prototypes are able to efficiently remove biofilm without dentine surface alterations, regardless of the operating frequency or instrument material.

CLINICAL RELEVANCE: Ultrasonic scalers based on a planar piezoelectric transducer might be an alternative to currently available ultrasonic scalers.},
}

*Biofilms
*Fibroblasts
Humans
*Surface Properties
*Titanium
*Dental Scaling/instrumentation
In Vitro Techniques
*Dentin/microbiology
*Periodontal Ligament/cytology
Transducers
Cell Adhesion
Stainless Steel
Equipment Design
Ultrasonic Therapy/instrumentation

@article {pmid38695568,
year = {2024},
author = {Kaplan, JB and Horswill, AR},
title = {Micrococcal nuclease regulates biofilm formation and dispersal in methicillin-resistant Staphylococcus aureus USA300.},
journal = {mSphere},
volume = {},
number = {},
pages = {e0012624},
doi = {10.1128/msphere.00126-24},
pmid = {38695568},
issn = {2379-5042},
abstract = {Biofilm formation is an important virulence factor for methicillin-resistant Staphylococcus aureus (MRSA). The extracellular matrix of MRSA biofilms contains significant amounts of double-stranded DNA that hold the biofilm together. MRSA cells secrete micrococcal nuclease (Nuc1), which degrades double-stranded DNA. In this study, we used standard methodologies to investigate the role of Nuc1 in MRSA biofilm formation and dispersal. We quantified biofilm formation and extracellular DNA (eDNA) levels in broth and agar cultures. In some experiments, cultures were supplemented with sub-MIC amoxicillin to induce biofilm formation. Biofilm erosion was quantitated by culturing biofilms on rods and enumerating detached colony-forming units (CFUs), and biofilm sloughing was investigated by perfusing biofilms cultured in glass tubes with fresh broth and measuring the sizes of the detached cell aggregates. We found that an MRSA nuc1[-] mutant strain produced significantly more biofilm and more eDNA than a wild-type strain, both in the absence and presence of sub-MIC amoxicillin. nuc1[-] mutant biofilms grown on rods detached significantly less than wild-type biofilms. Detachment was restored by exogenous DNase or complementing the nuc1[-] mutant. In the sloughing assay, nuc1[-] mutant biofilms released cell aggregates that were significantly larger than those released by wild-type biofilms. Our results suggest that Nuc1 modulates biofilm formation, biofilm detachment, and the sizes of detached cell aggregates. These processes may play a role in the spread and subsequent survival of MRSA biofilms during biofilm-related infections.IMPORTANCEInfections caused by antibiotic-resistant bacteria known as methicillin-resistant Staphylococcus aureus (MRSA) are a significant problem in hospitals. MRSA forms adherent biofilms on implanted medical devices such as catheters and breathing tubes. Bacteria can detach from biofilms on these devices and spread to other parts of the body such as the blood or lungs, where they can cause life-threatening infections. In this article, researchers show that MRSA secretes an enzyme known as thermonuclease that causes bacteria to detach from the biofilm. This is important because understanding the mechanism by which MRSA detaches from biofilms could lead to the development of procedures to mitigate the problem.},
}

@article {pmid38695444,
year = {2024},
author = {Dos Santos, ACM and Mendes, FSF and Pompeo, FT and Watanabe, E and Macedo, AP and de Souza, VOP and Paranhos, HFO and Silva-Lovato, CH},
title = {Effectiveness of experimental dentifrices based on essential oils on biofilm on complete dentures: an in vitro study.},
journal = {Journal of applied oral science : revista FOB},
volume = {32},
number = {},
pages = {e20230397},
doi = {10.1590/1678-7757-2023-0397},
pmid = {38695444},
issn = {1678-7765},
mesh = {*Biofilms/drug effects ; *Dentifrices/pharmacology/chemistry ; *Oils, Volatile/pharmacology/chemistry ; *Denture, Complete/microbiology ; *Materials Testing ; Time Factors ; Reproducibility of Results ; Toothbrushing ; Colony Count, Microbial ; Staphylococcus aureus/drug effects ; Statistics, Nonparametric ; Streptococcus mutans/drug effects ; Analysis of Variance ; Microbial Viability/drug effects ; Candida albicans/drug effects ; Reference Values ; Acrylic Resins/chemistry/pharmacology ; },
abstract = {UNLABELLED: Specific products containing natural resources can contribute to the innovation of complete denture hygiene.

OBJECTIVE: To conduct an in vitro evaluation of experimental dentifrices containing essential oils of Bowdichia virgilioides Kunth (BvK), Copaifera officinalis (Co), Eucalyptus citriodora (Ec), Melaleuca alternifolia (Ma) and Pinus strobus (Ps) at 1%.

METHODOLOGY: The variables evaluated were organoleptic and physicochemical characteristics, abrasiveness (mechanical brushing machine) simulating 2.5 years, and microbial load (Colony Forming Units - CFU/mL), metabolic activity (XTT assay) and cell viability (Live/Dead® BacLight™ kit) of the multispecies biofilm (Streptococcus mutans: Sm, Staphylococcus aureus: Sa, Candida albicans: Ca and Candida glabrata: Cg). Specimens of heat-polymerized acrylic resins (n=256) (n=96 specimens for abrasiveness, n=72 for microbial load count, n=72 for biofilm metabolic activity, n=16 for cell viability and total biofilm quantification) with formed biofilm were divided into eight groups for manual brushing (20 seconds) with a dental brush and distilled water (NC: negative control), Trihydral (PC: positive control), placebo (Pl), BvK, Co, Ec, Ma or Ps. After brushing, the specimens were washed with PBS and immersed in Letheen Broth medium, and the suspension was sown in solid specific medium. The organoleptic characteristics were presented by descriptive analysis. The values of density, pH, consistency and viscosity were presented in a table. The data were analyzed with the Wald test in a generalized linear model, followed by the Kruskal-Wallis test, Dunn's test (mass change) and the Bonferroni test (UFC and XTT). The Wald test in Generalized Estimating Equations and the Bonferroni test were used to analyze cell viability.

RESULTS: All dentifrices showed stable organoleptic characteristics and adequate physicochemical properties. CN, Ec, Ps, Pl and PC showed low abrasiveness. There was a significant difference between the groups (p<0.001) for microbial load, metabolic activity and biofilm viability.

CONCLUSIONS: It was concluded that the BvK, Ec and Ps dentifrices are useful for cleaning complete dentures, as they have antimicrobial activity against biofilm. The dentifrices containing Bowdichia virgilioides Kunth showed medium abrasiveness and should be used with caution.},
}

*Biofilms/drug effects
*Dentifrices/pharmacology/chemistry
*Oils, Volatile/pharmacology/chemistry
*Denture, Complete/microbiology
*Materials Testing
Time Factors
Reproducibility of Results
Toothbrushing
Colony Count, Microbial
Staphylococcus aureus/drug effects
Statistics, Nonparametric
Streptococcus mutans/drug effects
Analysis of Variance
Microbial Viability/drug effects
Candida albicans/drug effects
Reference Values
Acrylic Resins/chemistry/pharmacology

@article {pmid38695072,
year = {2024},
author = {Søborg, DA and Højris, B and Brinkmann, K and Pedersen, MR and Skovhus, TL},
title = {Characterizing the development of biofilm in polyethylene pipes in the non-chlorinated Danish drinking-water distribution system.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-18},
doi = {10.1080/08927014.2024.2343839},
pmid = {38695072},
issn = {1029-2454},
abstract = {In newly commissioned drinking-water polyethylene (PE) pipes, biofilm develops on the inner pipe surface. The microbial community composition from colonization to the establishment of mature biofilms is less known, including the effect on the distributed water quality. Biofilm development was followed through 1.5 years in PE-pipe side streams at two locations of a full-scale, non-chlorinated drinking-water distribution system (leaving a waterworks versus 5-6 km from a waterworks) along with inlet and outlet water quality. Mature biofilms were established after ∼8-9 months, dominated by Proteobacteria, Actinobacteria and Saccharibacteria (61-93% relative abundance), with a higher diversity (OTUs/Shannon Index/16S rRNA gene amplicon sequencing) in pipes in the far end of the distribution system. Comamonadaceae, and specifically Aquabacterium (>30% of reads), dominated young (∼1.5-month-old) biofilms. Young biofilms were linked to increased microbiological counts in drinking water (HPC/ATP/qPCR), while the establishment of mature biofilms led to a drop in HPC and benefited the water quality, highlighting the importance of optimizing commissioning procedures for rapidly achieving mature and stable biofilms.},
}

@article {pmid38694801,
year = {2024},
author = {Zhou, X and Liu, H and Fan, X and Xu, X and Gao, Y and Bi, X and Cheng, L and Huang, S and Zhao, F and Yang, T},
title = {Innovative inbuilt moving bed biofilm reactor for nitrogen removal applied in household aquarium.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1373119},
doi = {10.3389/fmicb.2024.1373119},
pmid = {38694801},
issn = {1664-302X},
abstract = {An innovative inbuilt moving bed biofilm reactor (MBBR) was created to protect fish from nitrogen in a household aquarium. During the 90 experimental days, the ammonia nitrogen (NH4[+]-N) concentration in the aquarium with the inbuilt MBBR was always below 0.5 mg/L, which would not threaten the fish. Concurrently, nitrite and nitrate nitrogen concentrations were always below 0.05 mg/L and 4.5 mg/L, respectively. However, the blank contrast aquarium accumulated 1.985 mg/L NH4[+]-N on the 16th day, which caused the fish to die. The suspended biofilms could achieve the specific NH4[+]-N removal rate of 45.43 g/m[3]/d. Biofilms presented sparsely with filamentous structures and showed certain degrees of roughness. The bacterial communities of the suspended biofilms and the sediment were statistically different (p < 0.05), reflected in denitrifying and nitrifying bacteria. In particular, the relative abundance of Nitrospira reached 1.4%, while the genus was barely found in sediments. The suspended biofilms showed potentials for nitrification function with the predicted sequence numbers of ammonia monooxygenase [1.14.99.39] and hydroxylamine dehydrogenase [EC:1.7.2.6] of 220 and 221, while the values of the sediment were only 5 and 1. This study created an efficient NH4[+]-N removal inbuilt MBBR for household aquariums and explored its mechanism to afford a basis for its utilization.},
}

@article {pmid38693842,
year = {2024},
author = {Meng, Y and Chen, S and Wang, C and Ni, X},
title = {Advances in Composite Biofilm Biomimetic Nanodrug Delivery Systems for Cancer Treatment.},
journal = {Technology in cancer research & treatment},
volume = {23},
number = {},
pages = {15330338241250244},
doi = {10.1177/15330338241250244},
pmid = {38693842},
issn = {1533-0338},
mesh = {Humans ; *Neoplasms/drug therapy ; *Biofilms/drug effects ; *Drug Delivery Systems ; *Biomimetics/methods ; *Antineoplastic Agents/administration & dosage/pharmacology ; Biomimetic Materials/chemistry ; Animals ; Drug Carriers/chemistry ; },
abstract = {Single biofilm biomimetic nanodrug delivery systems based on single cell membranes, such as erythrocytes and cancer cells, have immune evasion ability, good biocompatibility, prolonged blood circulation, and high tumor targeting. Because of the different characteristics and functions of each single cell membrane, more researchers are using various hybrid cell membranes according to their specific needs. This review focuses on several different types of biomimetic nanodrug-delivery systems based on composite biofilms and looks forward to the challenges and possible development directions of biomimetic nanodrug-delivery systems based on composite biofilms to provide reference and ideas for future research.},
}

Humans
*Neoplasms/drug therapy
*Biofilms/drug effects
*Drug Delivery Systems
*Biomimetics/methods
*Antineoplastic Agents/administration & dosage/pharmacology
Biomimetic Materials/chemistry
Animals
Drug Carriers/chemistry

@article {pmid38692363,
year = {2024},
author = {Zhang, X and Zhao, Y and Wang, Y and Qian, H and Xing, J and Joseph, A and Rene, ER and Li, J and Zhu, N},
title = {The interplay of hematite and photic biofilm triggers acceleration of biotic nitrate removal.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {142136},
doi = {10.1016/j.chemosphere.2024.142136},
pmid = {38692363},
issn = {1879-1298},
abstract = {The soil-water interface is replete with photic biofilm and iron minerals; however, the potential of how iron minerals promote biotic nitrate removal is still unknown. This study investigates the physiological and ecological responses of photic biofilm to hematite (Fe2O3), in order to explore a practically feasible approach for in-situ nitrate removal. The nitrate removal rate of photic biofilm was significantly higher in the presence of Fe2O3 (92.5%) compared to the control (82.8%). Results show that the presence of Fe2O3 changed the community composition of photic biofilm, facilitates the thriving of Magnetospirillum and Pseudomonas, and promotes the growth of photic biofilm represented by the extracellular polymeric substance (EPS) and the content of chlorophyll. The presence of Fe2O3 also induces oxidative stress (•O2[-]) in photic biofilm, which was demonstrated by electron spin resonance spectrometry. However, the photic biofilm could improve the EPS productivity to prevent the entrance of Fe2O3 to cells in the biofilm matrix and mitigate oxidative stress. The Fe2O3 then promoted the relative abundance of Magnetospirillum and Pseudomonas and the activity of nitrate reductase, which accelerates nitrate reduction by photic biofilm. This study provides an insight into the interaction between iron minerals and photic biofilm and demonstrates the possibility of combining biotic and abiotic methods to improve the in-situ nitrate removal rate.},
}

@article {pmid38690364,
year = {2024},
author = {Meliefste, HM and Mudde, SE and Ammerman, NC and de Steenwinkel, JEM and Bax, HI},
title = {A laboratory perspective on Mycobacterium abscessus biofilm culture, characterization and drug activity testing.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1392606},
pmid = {38690364},
issn = {1664-302X},
abstract = {Mycobacterium abscessus is an emerging opportunistic pathogen causing severe pulmonary infections in patients with underlying lung disease and cystic fibrosis in particular. The rising prevalence of M. abscessus infections poses an alarming threat, as the success rates of available treatment options are limited. Central to this challenge is the absence of preclinical in vitro models that accurately mimic in vivo conditions and that can reliably predict treatment outcomes in patients. M. abscessus is notorious for its association with biofilm formation within the lung. Bacteria in biofilms are more recalcitrant to antibiotic treatment compared to planktonic bacteria, which likely contributes to the lack of correlation between preclinical drug activity testing (typically performed on planktonic bacteria) and treatment outcome. In recent years, there has been a growing interest in M. abscessus biofilm research. However, the absence of standardized methods for biofilm culture, biofilm characterization and drug activity testing has led to a wide spectrum of, sometimes inconsistent, findings across various studies. Factors such as strain selection, culture medium, and incubation time hugely impact biofilm development, phenotypical characteristics and antibiotic susceptibility. Additionally, a broad range of techniques are used to study M. abscessus biofilms, including quantification of colony-forming units, crystal violet staining and fluorescence microscopy. Yet, limitations of these techniques and the selected readouts for analysis affect study outcomes. Currently, research on the activity of conventional antibiotics, such as clarithromycin and amikacin, against M. abscessus biofilms yield ambiguous results, underscoring the substantial impact of experimental conditions on drug activity assessment. Beyond traditional drug activity testing, the exploration of novel anti-biofilm compounds and the improvement of in vitro biofilm models are ongoing. In this review, we outline the laboratory models, experimental variables and techniques that are used to study M. abscessus biofilms. We elaborate on the current insights of M. abscessus biofilm characteristics and describe the present understanding of the activity of traditional antibiotics, as well as potential novel compounds, against M. abscessus biofilms. Ultimately, this work contributes to the advancement of fundamental knowledge and practical applications of accurate preclinical M. abscessus models, thereby facilitating progress towards improved therapies for M. abscessus infections.},
}

@article {pmid38688866,
year = {2024},
author = {Antoine, C and Laforêt, F and Fall, A and Blasdel, B and Delcenserie, V and Thiry, D},
title = {K1 Capsule-dependent phage-driven evolution in Escherichia coli leading to phage resistance and biofilm production.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/jambio/lxae109},
pmid = {38688866},
issn = {1365-2672},
abstract = {AIMS: Understanding bacterial phage resistance mechanisms has implications for developing phage-based therapies. This study aimed to explore the development of phage resistance in Escherichia coli K1 isolates' to K1-ULINTec4, a K1-dependent bacteriophage.

METHODS AND RESULTS: Resistant colonies were isolated from two different strains (APEC 45 and C5), both previously exposed to K1-ULINTec4. Genome analysis and several parameters were assessed, including growth capacity, phage adsorption, phenotypic impact at capsular level, biofilm production and virulence in the in-vivo Galleria mellonella larvae model. One out of the 6 resistant isolates exhibited a significantly slower growth rate suggesting the presence of a resistance mechanism altering its fitness. Comparative genomic analysis revealed insertion sequences in the region 2 of the kps gene cluster involved in the capsule biosynthesis. In addition, an immunoassay targeting the K1 capsule showed a very low positive reaction compared to the control. Nevertheless, microscopic images of resistant strains revealed the presence of capsules with a clustered organization of bacterial cells and biofilm assessment showed an increased biofilm production compared to the sensitive strains. In the G. mellonella model, larvae infected with phage-resistant isolates showed better survival rates than larvae infected with phage-sensitive strains.

CONCLUSIONS: A phage resistance mechanism was identified at the genomic level and had a negative impact on the K1 capsule production. The resistant isolates showed an increased biofilm production, and a decreased virulence in vivo.},
}

@article {pmid38687259,
year = {2024},
author = {Wang, C and Ma, Q and Zhang, J and Meng, N and Xu, D},
title = {Co-culture of benzalkonium chloride promotes the biofilm formation and decreases the antibiotic susceptibility of a Pseudomonas aeruginosa strain.},
journal = {Environmental science. Processes & impacts},
volume = {},
number = {},
pages = {},
doi = {10.1039/d4em00035h},
pmid = {38687259},
issn = {2050-7895},
abstract = {Benzalkonium chloride (BAC) is a disinfectant with broad-spectrum antibacterial properties, yet despite its widespread use and detection in the environment, the effects of BAC exposure on microorganisms remain poorly documented. Herein, the impacts of BAC on a Pseudomonas aeruginosa strain Jade-X were systematically investigated. The results demonstrated that the minimum inhibitory concentration (MIC) of BAC against strain Jade-X was 64 mg L[-1]. Exposure to BAC concentrations of 8, 16, 32, and 64 mg L[-1] significantly augmented biofilm formation by 2.03-, 2.43-, 2.96-, and 2.56-fold respectively. The swimming and twitching abilities, along with the virulence factor production, were inhibited. Consistently, quantitative reverse transcription PCR assays revealed significant downregulation of genes related to flagellate- and pili-mediated motilities (flgD, flgE, pilB, pilQ, and motB), as well as phzA and phzB genes involved in pyocyanin production. The results of disk diffusion and MIC assays demonstrated that BAC decreased the antibiotic susceptibility of ciprofloxacin, levofloxacin, norfloxacin, and tetracycline. Conversely, an opposite trend was observed for polymyxin B and ceftriaxone. Genomic analysis revealed that strain Jade-X harbored eleven resistance-nodulation-cell division efflux pumps, with mexCD-oprJ exhibiting significant upregulation while mexEF-oprN and mexGHI-opmD were downregulated. In addition, the quorum sensing-related regulators LasR and RhlR were also suppressed, implying that BAC might modulate the physiological and biochemical behaviors of strain Jade-X by attenuating the quorum sensing system. This study enhances our understanding of interactions between BAC and P. aeruginosa, providing valuable insights to guide the regulation and rational use of BAC.},
}

@article {pmid38686667,
year = {2024},
author = {Rafiee, Z and Rezaie, M and Choi, S},
title = {Combined electrical-electrochemical phenotypic profiling of antibiotic susceptibility of in vitro biofilm models.},
journal = {The Analyst},
volume = {},
number = {},
pages = {},
doi = {10.1039/d4an00393d},
pmid = {38686667},
issn = {1364-5528},
abstract = {More than 65% of bacterial infections are caused by biofilms. However, standard biofilm susceptibility tests are not available for clinical use. All conventional biofilm models suffer from a long formation time and fail to mimic in vivo microbial biofilm conditions. Moreover, biofilms make it difficult to monitor the effectiveness of antibiotics. This work creates a powerful yet simple method to form a target biofilm and develops an innovative approach to monitoring the antibiotic's efficacy against a biofilm-associated infection. A paper-based culture platform can provide a new strategy for rapid microbial biofilm formation through capillary action. A combined electrical-electrochemical technique monitors bacterial metabolism rapidly and reliably by measuring microbial extracellular electron transfer (EET) and using electrochemical impedance spectroscopy (EIS) across a microbe-electrode interface. Three representative pathogens, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, form their biofilms controllably within an hour. Within another hour their susceptibilities to three frontline antibiotics with different action modes (gentamicin, ciprofloxacin, and ceftazidime) are examined. Our antibiotic susceptibility testing (AST) technique provides a quantifiable minimum inhibitory concentration (MIC) of those antibiotics against the in vitro biofilm models and characterizes their action mechanisms. The results will have an important positive effect because they provide immediately actionable healthcare information at a reduced cost, revolutionizing public healthcare.},
}

@article {pmid38686557,
year = {2024},
author = {Yang, L and Wang, X and Ma, Z and Sui, Y and Liu, X},
title = {Fangchinoline inhibits growth and biofilm of Candida albicans by inducing ROS overproduction.},
journal = {Journal of cellular and molecular medicine},
volume = {28},
number = {9},
pages = {e18354},
doi = {10.1111/jcmm.18354},
pmid = {38686557},
issn = {1582-4934},
support = {20220505041ZP//the Science and Technology Development Plan Project of Jilin Province/ ; 20200201595JC//Natural Science Foundation of Jilin Province/ ; JJKH20231220KJ//the Education Department of Jilin Province/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Candida albicans/drug effects/growth & development ; *Antifungal Agents/pharmacology ; *Reactive Oxygen Species/metabolism ; *Benzylisoquinolines/pharmacology ; *Microbial Sensitivity Tests ; Hyphae/drug effects/growth & development ; },
abstract = {Infections caused by Candida species, especially Candida albicans, threaten the public health and create economic burden. Shortage of antifungals and emergence of drug resistance call for new antifungal therapies while natural products were attractive sources for developing new drugs. In our study, fangchinoline, a bis-benzylisoquinoline alkaloid from Chinese herb Stephania tetrandra S. Moore, exerted antifungal effects on planktonic growth of several Candida species including C. albicans, with MIC no more than 50 μg/mL. In addition, results from microscopic, MTT and XTT reduction assays showed that fangchinoline had inhibitory activities against the multiple virulence factors of C. albicans, such as adhesion, hyphal growth and biofilm formation. Furthermore, this compound could also suppress the metabolic activity of preformed C. albicans biofilms. PI staining, followed by confocal laser scanning microscope (CLSM) analysis showed that fangchinoline can elevate permeability of cell membrane. DCFH-DA staining suggested its anti-Candida mechanism also involved overproduction of intracellular ROS, which was further confirmed by N-acetyl-cysteine rescue tests. Moreover, fangchinoline showed synergy with three antifungal drugs (amphotericin B, fluconazole and caspofungin), further indicating its potential use in treating C. albicans infections. Therefore, these results indicated that fangchinoline could be a potential candidate for developing anti-Candida therapies.},
}

*Biofilms/drug effects/growth & development
*Candida albicans/drug effects/growth & development
*Antifungal Agents/pharmacology
*Reactive Oxygen Species/metabolism
*Benzylisoquinolines/pharmacology
*Microbial Sensitivity Tests
Hyphae/drug effects/growth & development

@article {pmid38685359,
year = {2024},
author = {Farah, N and Lim, CW and Chin, VK and Chong, PP and Basir, R and Yeo, WWY and Tay, ST and Choo, S and Lee, TY},
title = {Photoactivated riboflavin inhibits planktonic and biofilm growth of Candida albicans and non-albicans Candida species.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {106665},
doi = {10.1016/j.micpath.2024.106665},
pmid = {38685359},
issn = {1096-1208},
abstract = {Fungal infections caused by Candida species pose a serious threat to humankind. Antibiotics abuse and the ability of Candida species to form biofilm have escalated the emergence of drug resistance in clinical settings and hence, rendered it more difficult to treat Candida-related diseases. Lethal effects of Candida infection are often due to inefficacy of antimicrobial treatments and failure of host immune response to clear infections. Previous studies have shown that a combination of riboflavin with UVA (riboflavin/UVA) light demonstrate candidacidal activity albeit its mechanism of actions remain elusive. Thus, this study sought to investigate antifungal and antibiofilm properties by combining riboflavin with UVA against Candida albicans and non-albicans Candida species. The MIC20 for the fluconazole and riboflavin/UVA against the Candida species tested was within the range of 0.125 to 2 μg/mL while the SMIC50 was 32 μg/mL. Present findings indicate that the inhibitory activities exerted by riboflavin/UVA towards planktonic cells are slightly less effective as compared to controls. However, the efficacy of the combination towards Candida species biofilms showed otherwise. Inhibitory effects exerted by riboflavin/UVA towards most of the tested Candida species biofilms points towards a variation in mode of action that could make it an ideal alternative therapeutic for biofilm-related infections.},
}

@article {pmid38683213,
year = {2024},
author = {Lendel, AM and Antonova, NP and Grigoriev, IV and Usachev, EV and Gushchin, VA and Vasina, DV},
title = {Biofilm-disrupting effects of phage endolysins LysAm24, LysAp22, LysECD7, and LysSi3: breakdown the matrix.},
journal = {World journal of microbiology & biotechnology},
volume = {40},
number = {6},
pages = {186},
pmid = {38683213},
issn = {1573-0972},
support = {23-74-10027//Russian Science Foundation/ ; 23-74-10027//Russian Science Foundation/ ; 23-74-10027//Russian Science Foundation/ ; 23-74-10027//Russian Science Foundation/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Endopeptidases/metabolism/pharmacology/chemistry ; *Bacteriophages/enzymology ; Acinetobacter baumannii/drug effects ; Klebsiella pneumoniae/drug effects ; Viral Proteins/metabolism ; Anti-Bacterial Agents/pharmacology/chemistry ; N-Acetylmuramoyl-L-alanine Amidase/metabolism/chemistry ; },
abstract = {The ability of most opportunistic bacteria to form biofilms, coupled with antimicrobial resistance, hinder the efforts to control widespread infections, resulting in high risks of negative outcomes and economic costs. Endolysins are promising compounds that efficiently combat bacteria, including multidrug-resistant strains and biofilms, without a low probability of subsequent emergence of stable endolysin-resistant phenotypes. However, the details of antibiofilm effects of these enzymes are poorly understood. To elucidate the interactions of bacteriophage endolysins LysAm24, LysAp22, LysECD7, and LysSi3 with bacterial films formed by Gram-negative species, we estimated their composition and assessed the endolysins' effects on the most abundant exopolymers in vitro. The obtained data suggests a pronounced efficiency of these lysins against biofilms with high (Klebsiella pneumoniae) and low (Acinetobacter baumannii) matrix contents, or dual-species biofilms, resulting in at least a twofold loss of the biomass. These peptidoglycan hydrolases interacted diversely with protective compounds of biofilms such as extracellular DNA and polyanionic carbohydrates, indicating a spectrum of biofilm-disrupting effects for bacteriolytic phage enzymes. Specifically, we detected disruption of acid exopolysaccharides by LysAp22, strong DNA-binding capacity of LysAm24, both of these interactions for LysECD7, and neither of them for LysSi3.},
}

*Biofilms/drug effects/growth & development
*Endopeptidases/metabolism/pharmacology/chemistry
*Bacteriophages/enzymology
Acinetobacter baumannii/drug effects
Klebsiella pneumoniae/drug effects
Viral Proteins/metabolism
Anti-Bacterial Agents/pharmacology/chemistry
N-Acetylmuramoyl-L-alanine Amidase/metabolism/chemistry

@article {pmid38683167,
year = {2024},
author = {Sun, G and Huang, S and Wang, S and Li, Y},
title = {Nanomaterial-based drug-delivery system as an aid to antimicrobial photodynamic therapy in treating oral biofilm.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {},
doi = {10.2217/fmb-2023-0259},
pmid = {38683167},
issn = {1746-0921},
abstract = {Diverse microorganisms live as biofilm in the mouth accounts for oral diseases and treatment failure. For decades, the prevention and treatment of oral biofilm is a global challenge. Antimicrobial photodynamic therapy (aPDT) holds promise for oral biofilm elimination due to its several traits, including broad-spectrum antimicrobial capacity, lower possibility of resistance and low cytotoxicity. However, the physicochemical properties of photosensitizers and the biological barrier of oral biofilm have limited the efficiency of aPDT. Nanomaterials has been used to fabricate nanocarriers to improve photosensitizer properties and thus enhance antimicrobial effect. In this review, we have discussed the challenges of aPDT used in dentistry, categorized the nanomaterial-delivery system and listed the possible mechanisms involved in nanomaterials when enhancing aPDT effect.},
}

@article {pmid38683166,
year = {2024},
author = {Rajangam, SL and Narasimhan, MK},
title = {Current treatment strategies for targeting virulence factors and biofilm formation in Acinetobacter baumannii.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {},
doi = {10.2217/fmb-2023-0263},
pmid = {38683166},
issn = {1746-0921},
abstract = {A higher prevalence of Acinetobacter baumannii infections and mortality rate has been reported recently in hospital-acquired infections (HAI). The biofilm-forming capability of A. baumannii makes it an extremely dangerous pathogen, especially in device-associated hospital-acquired infections (DA-HAI), thereby it resists the penetration of antibiotics. Further, the transmission of the SARS-CoV-2 virus was exacerbated in DA-HAI during the epidemic. This review specifically examines the complex interconnections between several components and genes that play a role in the biofilm formation and the development of infections. The current review provides insights into innovative treatments and therapeutic approaches to combat A. baumannii biofilm-related infections, thereby ultimately improving patient outcomes and reducing the burden of HAI.},
}

@article {pmid38683039,
year = {2024},
author = {Oh, MJ and Kim, JH and Kim, J and Lee, S and Xiang, Z and Liu, Y and Koo, H and Lee, D},
title = {Drug-loaded adhesive microparticles for biofilm prevention on oral surfaces.},
journal = {Journal of materials chemistry. B},
volume = {},
number = {},
pages = {},
doi = {10.1039/d4tb00134f},
pmid = {38683039},
issn = {2050-7518},
abstract = {The oral cavity, a warm and moist environment, is prone to the proliferation of microorganisms like Candida albicans (C. albicans), which forms robust biofilms on biotic and abiotic surfaces, leading to challenging infections. These biofilms are resistant to conventional treatments due to their resilience against antimicrobials and immune responses. The dynamic nature of the oral cavity, including the salivary flow and varying surface properties, complicates the delivery of therapeutic agents. To address these challenges, we introduce dendritic microparticles engineered for enhanced adhesion to dental surfaces and effective delivery of antifungal agents and antibiofilm enzymes. These microparticles are fabricated using a water-in-oil-in-water emulsion process involving a blend of poly(lactic-co-glycolic acid) (PLGA) random copolymer (RCP) and PLGA-b-poly(ethylene glycol) (PLGA-b-PEG) block copolymer (BCP), resulting in particles with surface dendrites that exhibit strong adhesion to oral surfaces. Our study demonstrates the potential of these adhesive microparticles for oral applications. The adhesion tests on various oral surfaces, including dental resin, hydroxyapatite, tooth enamel, and mucosal tissues, reveal superior adhesion of these microparticles compared to conventional spherical ones. Furthermore, the release kinetics of nystatin from these microparticles show a sustained release pattern that can kill C. albicans. The biodegradation of these microparticles on tooth surfaces and their efficacy in preventing fungal biofilms have also been demonstrated. Our findings highlight the effectiveness of adhesive microparticles in delivering therapeutic agents within the oral cavity, offering a promising approach to combat biofilm-associated infections.},
}

@article {pmid38682908,
year = {2024},
author = {Michaelis, S and Chen, T and Schmid, C and Hilbi, H},
title = {Nitric oxide signaling through three receptors regulates virulence, biofilm formation, and phenotypic heterogeneity of Legionella pneumophila.},
journal = {mBio},
volume = {},
number = {},
pages = {e0071024},
doi = {10.1128/mbio.00710-24},
pmid = {38682908},
issn = {2150-7511},
abstract = {UNLABELLED: The causative agent of Legionnaires' disease, Legionella pneumophila, is an environmental bacterium, that replicates in macrophages, parasitizes amoeba, and forms biofilms. L. pneumophila employs the Legionella quorum sensing (Lqs) system and the transcription factor LvbR to control various bacterial traits, including virulence and biofilm architecture. LvbR negatively regulates the nitric oxide (NO) receptor Hnox1, linking quorum sensing to NO signaling. Here, we assessed the response of L. pneumophila to NO and investigated bacterial receptors underlying this process. Chemical NO donors, such as dipropylenetriamine (DPTA) NONOate and sodium nitroprusside (SNP), delayed and reduced the expression of the promoters for flagellin (PflaA) and the 6S small regulatory RNA (P6SRNA). Marker-less L. pneumophila mutant strains lacking individual (Hnox1, Hnox2, or NosP) or all three NO receptors (triple knockout, TKO) grew like the parental strain in media. However, in the TKO strain, the reduction of PflaA expression by DPTA NONOate was less pronounced, suggesting that the NO receptors are implicated in NO signaling. In the ΔnosP mutant, the lvbR promoter was upregulated, indicating that NosP negatively regulates LvbR. The single and triple NO receptor mutant strains were impaired for growth in phagocytes, and phenotypic heterogeneity of non-growing/growing bacteria in amoebae was regulated by the NO receptors. The single NO receptor and TKO mutant strains showed altered biofilm architecture and lack of response of biofilms to NO. In summary, we provide evidence that L. pneumophila regulates virulence, intracellular phenotypic heterogeneity, and biofilm formation through NO and three functionally non-redundant NO receptors, Hnox1, Hnox2, and NosP.

IMPORTANCE: The highly reactive diatomic gas molecule nitric oxide (NO) is produced by eukaryotes and bacteria to promote short-range and transient signaling within and between neighboring cells. Despite its importance as an inter-kingdom and intra-bacterial signaling molecule, the bacterial response and the underlying components of the signaling pathways are poorly characterized. The environmental bacterium Legionella pneumophila forms biofilms and replicates in protozoan and mammalian phagocytes. L. pneumophila harbors three putative NO receptors, one of which crosstalks with the Legionella quorum sensing (Lqs)-LvbR network to regulate various bacterial traits, including virulence and biofilm architecture. In this study, we used pharmacological, genetic, and cell biological approaches to assess the response of L. pneumophila to NO and to demonstrate that the putative NO receptors are implicated in NO detection, bacterial replication in phagocytes, intracellular phenotypic heterogeneity, and biofilm formation.},
}

@article {pmid38681738,
year = {2024},
author = {Orfali, R and Ghaffar, S and AlAjlan, L and Perveen, S and Al-Turki, E and Ameen, F},
title = {Diabetes-related lower limb wounds: Antibiotic susceptibility pattern and biofilm formation.},
journal = {Saudi pharmaceutical journal : SPJ : the official publication of the Saudi Pharmaceutical Society},
volume = {32},
number = {6},
pages = {102069},
pmid = {38681738},
issn = {1319-0164},
abstract = {The expeditious incidence of diabetes mellitus in Riyadh, Saudi Arabia, there is a significant increase in the total number of people with diabetic foot ulcers. For diabetic lower limb wound infections (DLWs) to be effectively treated, information on the prevalence of bacteria that cause in this region as well as their patterns of antibiotic resistance is significant. Growing evidence indicates that biofilm formers are present in chronic DFU and that these biofilm formers promote the emergence of multi-drug antibiotic resistant (MDR) strains and therapeutic rejection. The current study targeted to isolate bacteria from wounds caused by diabetes specifically at hospitals in Riyadh and assess the bacterium's resistance to antibiotics and propensity to develop biofilms. Totally 63 pathogenic microbes were identified from 70 patients suffering from DFU. Sixteen (25.4%) of the 63 bacterial strains were gram-positive, and 47 (74.6%) were gram-negative. Most of the gram-negative bacteria were resistant to tigecycline, nitrofurantoin, ampicillin, amoxicillin, cefalotin, and cefoxitin. Several gram-negative bacteria are susceptible to piperacillin, meropenem, amikacin, gentamicin, imipenem, ciprofloxacin, and trimethoprim. The most significant antibiotic that demonstrated 100% susceptibility to all pathogens was meropenem. Serratia marcescens and Staphylococcus aureus were shown to have significant biofilm formers. MDR bacterial strains comprised about 87.5% of the biofilm former strains. To the best of our knowledge, Riyadh, Saudi Arabia is the first region where Serratia marcescens was the most common bacteria from DFU infections. Our research findings would deliver information on evidence-based alternative strategies to develop effective treatment approaches for DFU treatment.},
}

@article {pmid38681224,
year = {2024},
author = {Lai, CH and Wong, MY and Huang, TY and Kao, CC and Lin, YH and Lu, CH and Huang, YK},
title = {Exploration of agr types, virulence-associated genes, and biofilm formation ability in Staphylococcus aureus isolates from hemodialysis patients with vascular access infections.},
journal = {Frontiers in cellular and infection microbiology},
volume = {14},
number = {},
pages = {1367016},
pmid = {38681224},
issn = {2235-2988},
mesh = {*Biofilms/growth & development ; Humans ; *Renal Dialysis/adverse effects ; *Staphylococcus aureus/genetics/isolation & purification/physiology/pathogenicity ; *Staphylococcal Infections/microbiology ; *Virulence Factors/genetics ; *Bacterial Proteins/genetics/metabolism ; Trans-Activators/genetics ; Virulence/genetics ; Catheter-Related Infections/microbiology ; Methicillin-Resistant Staphylococcus aureus/genetics/isolation & purification/pathogenicity ; Male ; Middle Aged ; Female ; },
abstract = {INTRODUCTION: Staphylococcus aureus, is a pathogen commonly encountered in both community and hospital settings. Patients receiving hemodialysis treatment face an elevated risk of vascular access infections (VAIs) particularly Staphylococcus aureus, infection. This heightened risk is attributed to the characteristics of Staphylococcus aureus, , enabling it to adhere to suitable surfaces and form biofilms, thereby rendering it resistant to external interventions and complicating treatment efforts.

METHODS: Therefore this study utilized PCR and microtiter dish biofilm formation assay to determine the difference in the virulence genes and biofilm formation among in our study collected of 103 Staphylococcus aureus, isolates from hemodialysis patients utilizing arteriovenous grafts (AVGs), tunneled cuffed catheters (TCCs), and arteriovenous fistulas (AVFs) during November 2013 to December 2021.

RESULTS: Our findings revealed that both MRSA and MSSA isolates exhibited strong biofilm production capabilities. Additionally, we confirmed the presence of agr types and virulence genes through PCR analysis. The majority of the collected isolates were identified as agr type I. However, agr type II isolates displayed a higher average number of virulence genes, with MRSA isolates exhibiting a variety of virulence genes. Notably, combinations of biofilm-associated genes, such as eno-clfA-clfB-fib-icaA-icaD and eno-clfA-clfB-fib-fnbB-icaA-icaD, were prevalent among Staphylococcus aureus, isolates obtained from vascular access infections.

DISCUSSION: These insights contribute to a better understanding of the molecular characteristics associated with Staphylococcus aureus, infections in hemodialysis patients and provided more targeted and effective treatment approaches.},
}

*Biofilms/growth & development
Humans
*Renal Dialysis/adverse effects
*Staphylococcus aureus/genetics/isolation & purification/physiology/pathogenicity
*Staphylococcal Infections/microbiology
*Virulence Factors/genetics
*Bacterial Proteins/genetics/metabolism
Trans-Activators/genetics
Virulence/genetics
Catheter-Related Infections/microbiology
Methicillin-Resistant Staphylococcus aureus/genetics/isolation & purification/pathogenicity
Male
Middle Aged
Female

@article {pmid38680918,
year = {2024},
author = {Behzadnia, A and Moosavi-Nasab, M and Oliyaei, N},
title = {Anti-biofilm activity of marine algae-derived bioactive compounds.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1270174},
pmid = {38680918},
issn = {1664-302X},
abstract = {A large number of microbial species tend to communicate and produce biofilm which causes numerous microbial infections, antibiotic resistance, and economic problems across different industries. Therefore, advanced anti-biofilms are required with novel attributes and targets, such as quorum sensing communication system. Meanwhile, quorum sensing inhibitors as promising anti-biofilm molecules result in the inhibition of particular phenotype expression blocking of cell-to-cell communication, which would be more acceptable than conventional strategies. Many natural products are identified as anti-biofilm agents from different plants, microorganisms, and marine extracts. Marine algae are promising sources of broadly novel compounds with anti-biofilm activity. Algae extracts and their metabolites such as sulfated polysaccharides (fucoidan), carotenoids (zeaxanthin and lutein), lipid and fatty acids (γ-linolenic acid and linoleic acid), and phlorotannins can inhibit the cell attachment, reduce the cell growth, interfere in quorum sensing pathway by blocking related enzymes, and disrupt extracellular polymeric substances. In this review, the mechanisms of biofilm formation, quorum sensing pathway, and recently identified marine algae natural products as anti-biofilm agents will be discussed.},
}

@article {pmid38680142,
year = {2024},
author = {Lenchenko, E and Sachivkina, N and Petrukhina, O and Petukhov, N and Zharov, A and Zhabo, N and Avdonina, M},
title = {Anatomical, pathological, and histological features of experimental respiratory infection of birds by biofilm-forming bacteria Staphylococcus aureus.},
journal = {Veterinary world},
volume = {17},
number = {3},
pages = {612-619},
doi = {10.14202/vetworld.2024.612-619},
pmid = {38680142},
issn = {0972-8988},
abstract = {BACKGROUND AND AIM: The pathogenesis of staphylococcal infections is mediated by virulence factors, such as enzymes, toxins, and biofilms, which increase the resistance of microorganisms to host immune system evasion. Testing and searching for standardized multi-level algorithms for the indication and differentiation of biofilms at the early stages of diagnosis will contribute to the development of preventive measures to control the critical points of technology and manage dangerous risk factors for the spread of infectious diseases. This research aimed to study the main stages of Staphylococcus aureus biofilm formation in in vitro experiments and to analyze the dynamics of respiratory syndrome development in chickens infected with these bacteria.

MATERIALS AND METHODS: Experimental reproduction of the infectious process was performed using laboratory models: 10-day-old White Leghorn chickens (n = 20). Before the experiments, the birds were divided into two groups according to the principle of analogs: Group I (control, n = 10): the birds were intranasally inoculated with 0.5 cm[3] of 0.9% NaCl solution; Group II (experiment, n = 10): the birds were intranasally inoculated with a suspension of S. aureus bacteria, 0.5 cm[3], concentration 1 billion/cm[3].

RESULTS: Colonization of individual areas of the substrate under study in vitro occurred gradually from the sedimentation and adhesion of single motile planktonic cells to the attachment stage of microcolony development. Staining preparations with gentian violet due to the "metachromosia" property of this dye are a quick and fairly simple way to differentiate cells and the intercellular matrix of biofilms. Fixation with vapors of glutaraldehyde and osmium tetroxide preserves the natural architecture of biofilms under optical and scanning electron microscopy. Pure cultures of S. aureus microorganisms were isolated from the blood, lungs, small intestine, liver, kidneys, and spleen after 5-10 days during experimental infection of chickens. Clinical signs of respiratory syndrome developed within 5-6 days after infection. Acute and subacute serous-fibrinous airsacculitis, characterized by edema and thickening of the membranes of the air sacs and the presence of turbid, watery, foamy contents in the cavity, was the most characteristic pathomorphological sign. The signs of acute congestive hyperemia and one-sided serous-fibrinous pneumonia developed with significant thickening of fibrinous deposits. In Garder's gland, there was an increase in the number of secretory sections, indicating hypersecretion of the glands. In the lymphoid follicles of Meckel's diverticulum, leukocytes, usually lymphocytes, and pseudoeosinophils were detected.

CONCLUSIONS: Hydration and heteromorphism of the internal environment of biofilms determine the localization of differentiated cells in a three-dimensional matrix for protection against adverse factors. The most characteristic pathomorphological sign was the development of acute and subacute serous-fibrinous airsacculitis when reproducing the infectious process in susceptible models. There was a significant thickening of fibrinous deposits and signs of acute congestive hyperemia and one or two serous-fibrinous pneumonia developed.},
}

@article {pmid38680028,
year = {2024},
author = {Sobel, JD},
title = {Biofilm in Bacterial Vaginosis: A Legitimate Therapeutic Challenge?.},
journal = {The Journal of infectious diseases},
volume = {},
number = {},
pages = {},
doi = {10.1093/infdis/jiae135},
pmid = {38680028},
issn = {1537-6613},
}

@article {pmid38679227,
year = {2024},
author = {Pereira, IL and Cardoso, TL and Wozeak, DR and Caballero, PS and Buchhorn de Freitas, S and Pinto Seixas Neto, AC and da Silva Pinto, L and Hartwig, DD},
title = {Antibodies anti-rFilF protein has anti-biofilm activity against carbapenem-resistant Acinetobacter baumannii.},
journal = {Microbes and infection},
volume = {},
number = {},
pages = {105347},
doi = {10.1016/j.micinf.2024.105347},
pmid = {38679227},
issn = {1769-714X},
abstract = {Acinetobacter baumannii is an opportunistic bacterium that causes infection in several sites. Carbapenem-resistant A. baumannii strains (CRAb) lead the World Health Organization's list of 12 pathogens considered a priority for developing new antimicrobials. The pathogenicity of A. baumannii is related to the different virulence factors employed in the colonization of biotic and abiotic surfaces, biofilm formation and multidrug resistance. We analyze the outer membrane protein FilF from A. baumannii in silico and produce it in recombinant form (rFilF). rFilF protein was successfully expressed in Escherichia coli BL21 Star in an insoluble form. Immunization with rFilF induced significant anti-rFilF IgG antibody production in mice, detected by indirect enzyme-linked immunosorbent assay, since the first evaluation until 49[th]. On the last experimentation day, the predominant immunoglobulin found was IgG1 followed by IgG2a, IgG2b, IgM, IgG3, and IgA. We observe that interleukins 4 and 10 show significant production after the 28[th] day of experimentation in mice immunized with rFilF. Anti-rFilF pAbs were able to inhibit biofilm formation in nine CRAb strains evaluated, and in the standard strain ATCC® 19606. These results demonstrate the anti-biofilm activity of anti-rFilF antibodies, promising in the development of a non-antibiotic approach based on the control of CRAb strains.},
}

@article {pmid38679172,
year = {2024},
author = {Loi, JX and Syutsubo, K and Rabuni, MF and Takemura, Y and Aoki, M and Chua, ASM},
title = {Downflow sponge biofilm reactors for polluted raw water treatment: performance optimisation, kinetics, and microbial community.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {142156},
doi = {10.1016/j.chemosphere.2024.142156},
pmid = {38679172},
issn = {1879-1298},
abstract = {Water outages caused by elevated ammonium (NH4[+]-N) levels are a prevalent problem faced by conventional raw water treatment plants in developing countries. A treatment solution requires a short hydraulic retention time (HRT) to overcome nitrification rate limitation in oligotrophic conditions. In this study, the performance of polluted raw water treatment using a green downflow sponge biofilm (DSB) technology was evaluated. We operated two DSB reactors, DSB-1 and DSB-2 under different NH4[+]-N concentration ranges (DSB-1: 3.2 - 5.0 mg L[-1]; DSB-2: 1.7 - 2.6 mg L[-1]) over 360 days and monitored their performance under short HRT (60 min, 30 min, 20 min, and 15 min). The experimental results revealed vertical segregation of organic removal in the upper reactor depths and nitrification in the lower depths. Under the shortest HRT of 15 min, both DSB reactors achieved stable NH4[+]-N and chemical oxygen demand removal (≥ 95%) and produced minimal effluent nitrite (NO2[-]-N). DSB system could facilitate complete NH4[+]-N oxidation to nitrate (NO3[-]-N) without external aeration energy requirement. The 16S rRNA sequencing data revealed that nitrifying bacteria Nitrosomonas and Nitrospira in the reactor were stratified. Putative comammox bacteria with high ammonia affinity was successfully enriched in DSB-2 operating at a lower NH4[+]-N loading rate, which is advantageous in oligotrophic treatment. This study suggests that a high hydraulic rate DSB system with efficient ammonia removal could incorporate ammonia treatment capability into polluted raw water treatment process and ensure safe water supply in many developing countries.},
}

@article {pmid38678634,
year = {2024},
author = {Omer, SA and Ganjo, AR and Haji, SH and Smail, SB},
title = {Accessory Gene Regulator (agr) group polymorphisms in methicillin-resistant Staphylococcus aureus and its association with biofilm formation.},
journal = {Cellular and molecular biology (Noisy-le-Grand, France)},
volume = {70},
number = {4},
pages = {1-7},
doi = {10.14715/cmb/2024.70.4.1},
pmid = {38678634},
issn = {1165-158X},
mesh = {*Biofilms/growth & development/drug effects ; *Methicillin-Resistant Staphylococcus aureus/genetics/drug effects/isolation & purification/physiology ; *Bacterial Proteins/genetics/metabolism ; Humans ; Microbial Sensitivity Tests ; Trans-Activators/genetics/metabolism ; Anti-Bacterial Agents/pharmacology ; Staphylococcal Infections/microbiology ; Polymorphism, Genetic ; Hydrogen Peroxide/pharmacology/metabolism ; Lipase/genetics/metabolism ; *Xanthophylls ; },
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main causes of community- and hospital-acquired infections. The expression of virulence genes in S. aureus is arranged by regulators like the accessory gene regulator (agr). The present study aims to estimate phenotypic characteristics of S. aureus and investigate the occurrence of agr genes with their correlation to biofilm formation. In this study, 34 MRSA strains out of 100 S. aureus isolates were recovered in a variety of clinical samples. Phenotypic characterization and ability of biofilm formation were assessed. About 8(24%) of isolates were biofilm producers. The percentages of biofilm production among isolates were 3(37.5%), 2(25%), 3(37.5%) as strong, moderate, and weak, respectively. Furthermore, the resistance rates for all antibiotics were higher in biofilm producers and 76% of the isolates were staphyloxanthin producers, around 82% of the strains showed resistance to H2O2. Hemolytic activity was detected in 74% of the total isolates. The activity of the protease enzyme was 68%. The lipase enzyme was active in 79% of the tested S. aureus isolates. The majority of isolates were established to be agrI 84%, followed by agrII 53%, agrIII 32%, and 30% of the isolates have agr IV. Our study indicated that the majority of MRSA isolates were non-biofilm producers and the agr I is the most dominant type. Thus, agr I is not correlated with biofilm production.},
}

*Biofilms/growth & development/drug effects
*Methicillin-Resistant Staphylococcus aureus/genetics/drug effects/isolation & purification/physiology
*Bacterial Proteins/genetics/metabolism
Humans
Microbial Sensitivity Tests
Trans-Activators/genetics/metabolism
Anti-Bacterial Agents/pharmacology
Staphylococcal Infections/microbiology
Polymorphism, Genetic
Hydrogen Peroxide/pharmacology/metabolism
Lipase/genetics/metabolism
*Xanthophylls

@article {pmid38678425,
year = {2024},
author = {Suresh, K and Pillai, D},
title = {Prevalence of antimicrobial resistance, biofilm formation, efflux pump activity, and virulence capabilities in multi-drug-resistant Klebsiella pneumoniae isolated from freshwater fish farms.},
journal = {Journal of water and health},
volume = {22},
number = {4},
pages = {721-734},
pmid = {38678425},
issn = {1477-8920},
mesh = {*Klebsiella pneumoniae/drug effects/genetics/pathogenicity/isolation & purification/physiology ; *Biofilms/drug effects ; Animals ; Virulence ; *Drug Resistance, Multiple, Bacterial ; *Fishes/microbiology ; *Anti-Bacterial Agents/pharmacology ; India/epidemiology ; Fresh Water/microbiology ; Aquaculture ; Microbial Sensitivity Tests ; Bacterial Proteins/genetics/metabolism ; },
abstract = {The present study aimed to determine the antibiotic resistance, underlying mechanisms, antibiotic residues, and virulence genes involved in 32 multi-drug-resistant Klebsiella pneumoniae isolates from freshwater fishes in Andhra Pradesh, India. Antibiogram studies revealed that all isolates were multi-drug-resistant, harbored tetA (96.8%), tetC (59.3%), tetD (71.9%), nfsA (59.3%), nfsB (53.1%), sul2 (68.7%), qnrC (43.7%), qnrD (50%), blaSHV (75%), blaTEM (68.7%), and blaCTX-M (93.7%) genes. Multiple antibiotic resistance index was calculated as 0.54. Sixteen isolates were confirmed to be hyper-virulent and harbored magA and rmpA genes. In total, 46.9, 31.2, and 21.9% of the isolates were categorized as strong, moderate, or weak biofilm formers, respectively. All isolates possessed an active efflux pump and harbored acrA, acrB, acrAB, and tolC genes in 94% of the isolates, followed by mdtK (56.2%). Porins such as ompK35 and ompK36 were detected in 59.3 and 62.5% of the isolates, respectively. Virulence genes fimH-1, mrkD, and entB were present in 84.3, 81.2, 87.5% of the isolates, respectively. These findings imply a potential threat that multi-drug-resistant bacterial pathogens could transmit to surrounding environments and humans through contaminated water and the aquaculture food chain.},
}

*Klebsiella pneumoniae/drug effects/genetics/pathogenicity/isolation & purification/physiology
*Biofilms/drug effects
Animals
Virulence
*Drug Resistance, Multiple, Bacterial
*Fishes/microbiology
*Anti-Bacterial Agents/pharmacology
India/epidemiology
Fresh Water/microbiology
Aquaculture
Microbial Sensitivity Tests
Bacterial Proteins/genetics/metabolism

@article {pmid38678421,
year = {2024},
author = {Oyewale, AT and Odetoyin, BW and Oluduro, AO and Adeniyi, IF},
title = {Occurrence of coliforms and biofilm-forming bacteria in raw, treated, and distributed water from two waterwork systems in Osun State, Southwestern Nigeria.},
journal = {Journal of water and health},
volume = {22},
number = {4},
pages = {673-688},
pmid = {38678421},
issn = {1477-8920},
mesh = {Nigeria ; *Biofilms ; *Enterobacteriaceae/isolation & purification ; *Drinking Water/microbiology ; *Water Microbiology ; *Water Supply ; Bacteria/isolation & purification/classification/genetics ; Water Purification/methods ; },
abstract = {This study assessed the bacteriological quality of raw, treated, and distributed water from Ede-Erinle and Opa reservoirs in Osun State, Nigeria. This was to determine the potability of water from these waterwork stations. Eighteen sampling points were established across the two reservoir networks for this study. Samples were collected bi-monthly for two annual cycles. Serial dilution and pour plate methods were employed for the enumeration of bacterial load. Total heterotrophic bacteria count (THBC) and total coliform bacteria count (TCBC) were enumerated on nutrient and MacConkey agar at 37 °C, respectively. Bacterial isolates were characterized using biochemical identification methods with reference to Bergey's Manual of Determinative Bacteriology. Bacterial isolates and biofilm formation were further identified molecularly through the PCR method using specific universal primers. Mean values of THBC and TCBC in distributed water from Ede-Erinle (9.61 × 10[4] ± 1.50 × 10[4] CFU/mL; 69.56 ± 26.81 CFU/mL) and Opa waterworks (9.58 × 10[4] ± 2.55 × 10[4] CFU/mL; 142.94 ± 44.41 CFU/mL) exceeded permissible limits for drinking water. Paenibacillus lautus, Bacillus pseudomycoides, Pseudomonas aeruginosa, and Pseudomonas stutzeri showed biofilm-forming capacity. The study concluded that the presence of coliforms and biofilm-forming bacteria in distributed water implies that the water is unfit for consumption without further treatment.},
}

Nigeria
*Biofilms
*Enterobacteriaceae/isolation & purification
*Drinking Water/microbiology
*Water Microbiology
*Water Supply
Bacteria/isolation & purification/classification/genetics
Water Purification/methods

@article {pmid38677238,
year = {2024},
author = {Zhu, W and Liu, J and Zhang, Y and Zhao, D and Li, S and Dou, H and Wang, H and Xia, X},
title = {The role of rcpA gene in regulating biofilm formation and virulence in Vibrio parahaemolyticus.},
journal = {International journal of food microbiology},
volume = {418},
number = {},
pages = {110714},
doi = {10.1016/j.ijfoodmicro.2024.110714},
pmid = {38677238},
issn = {1879-3460},
abstract = {Vibrio parahaemolyticus (V. parahaemolyticus) is a common seafood-borne pathogen that can colonize the intestine of host and cause gastroenteritis. Biofilm formation by V. parahaemolyticus enhances its persistence in various environments, which poses a series of threats to food safety. This work aims to investigate the function of rcpA gene in biofilm formation and virulence of V. parahaemolyticus. Deletion of rcpA significantly reduced motility, biofilm biomass, and extracellular polymeric substances, and inhibited biofilm formation on a variety of food and food contact surfaces. In mice infection model, mice infected with ∆rcpA strain exhibited a decreased rate of pathogen colonization, a lower level of inflammatory cytokines, and less tissue damage when compared to mice infected with wild type strain. RNA-seq analysis revealed that 374 genes were differentially expressed in the rcpA deletion mutant, which include genes related to quorum sensing, flagellar system, ribosome, type VI secretion system, biotin metabolism and transcriptional regulation. In conclusion, rcpA plays a role in determining biofilm formation and virulence of V. parahaemolyticus and further research is necessitated to fully understand its function in V. parahaemolyticus.},
}

@article {pmid38677122,
year = {2024},
author = {Xue, J and Ma, H and Dong, X and Shi, K and Zhou, X and Qiao, Y and Gao, Y and Liu, Y and Feng, Y and Jiang, Q},
title = {Insights into the response of electroactive biofilm with petroleum hydrocarbons degradation ability to quorum sensing signals.},
journal = {Journal of hazardous materials},
volume = {471},
number = {},
pages = {134407},
doi = {10.1016/j.jhazmat.2024.134407},
pmid = {38677122},
issn = {1873-3336},
abstract = {Bioelectrochemical technologies based on electroactive biofilms (EAB) are promising for petroleum hydrocarbons (PHs) remediation as anode can serve as inexhaustible electron acceptor. However, the toxicity of PHs might inhibit the formation and function of EABs. Quorum sensing (QS) is ideal for boosting the performance of EABs, but its potential effects on reshaping microbial composition of EABs in treating PHs are poorly understood. Herein, two AHL signals, C4-HSL and C12-HSL, were employed to promote EABs for PHs degradation. The start-times of AHL-mediated EABs decreased by 18-26%, and maximum current densities increased by 28-63%. Meanwhile, the removal of total PHs increased to over 90%. AHLs facilitate thicker and more compact biofilm as well as higher viability. AHLs enhanced the electroactivity and direct electron transfer capability. The total abundance of PH-degrading bacteria increased from 52.05% to 75.33% and 72.02%, and the proportion of electroactive bacteria increased from 26.14% to 62.72% and 63.30% for MFC-C4 and MFC-C12. Microbial networks became more complex, aggregated, and stable with addition of AHLs. Furthermore, AHL-stimulated EABs showed higher abundance of genes related to PHs degradation. This work advanced our understanding of AHL-mediated QS in maintaining the stable function of microbial communities in the biodegradation process of petroleum hydrocarbons.},
}

@article {pmid38677054,
year = {2024},
author = {Gourari-Bouzouina, K and Boucherit-Otmani, Z and Seghir, A and Baba Ahmed-Kazi Tani, ZZ and Bendoukha, I and Benahmed, A and Aissaoui, M and Boucherit, K},
title = {Evaluation of mixed biofilm production by Candida spp. and Staphylococcus aureus strains co-isolated from cystic fibrosis patients in northwest Algeria.},
journal = {Diagnostic microbiology and infectious disease},
volume = {109},
number = {3},
pages = {116321},
doi = {10.1016/j.diagmicrobio.2024.116321},
pmid = {38677054},
issn = {1879-0070},
abstract = {Cystic fibrosis patients' lungs are chronically colonized by multiple microbial species capable of forming biofilms. This study aimed to characterize the polymicrobial biofilm formed by Candida spp. and S. aureus, co-isolated from sputum samples of cystic fibrosis patients regarding microbial density, metabolic activity, and structure. 67 samples from 28 patients were collected with a 96% alteration rate. 34% showed alterations by both Candida spp. and Gram-positive bacteria, predominantly Candida spp. and S. aureus in 77% of cases, accounting for 6 associations. Biofilm biomass was quantified using the crystal violet assay, and metabolic activity was assessed using the MTT reduction assay. Scanning electron microscopy analyzed the C. tropicalis/S. aureus24 biofilm architecture. Candida spp. isolates demonstrated the ability to form mixed biofilms with S. aureus. The C. tropicalis/S. aureus24 association exhibited the highest production of biofilm and metabolic activity, along with the C. albicans17/C. rugosa/S. aureus7 in both single and mixed biofilms.},
}

@article {pmid38677035,
year = {2024},
author = {Han, X and Fu, L and Yu, J and Li, K and Deng, Z and Shu, R and Wang, D and You, J and Zeng, EY},
title = {Effects of erythromycin on biofilm formation and resistance mutation of Escherichia coli on pristine and UV-aged polystyrene microplastics.},
journal = {Water research},
volume = {256},
number = {},
pages = {121628},
doi = {10.1016/j.watres.2024.121628},
pmid = {38677035},
issn = {1879-2448},
abstract = {Microplastics (MPs) and antibiotics co-occur widely in the environment and pose combined risk to microbial communities. The present study investigated the effects of erythromycin on biofilm formation and resistance mutation of a model bacterium, E. coli, on the surface of pristine and UV-aged polystyrene (PS) MPs sized 1-2 mm. The properties of UV-aged PS were significantly altered compared to pristine PS, with notable increases in specific surface area, carbonyl index, hydrophilicity, and hydroxyl radical content. Importantly, the adsorption capacity of UV-aged PS towards erythromycin was approximately 8-fold higher than that of pristine PS. Biofilms colonizing on UV-aged PS had a greater cell count (5.6 × 10[8] CFU mg[-1]) and a higher frequency of resistance mutation (1.0 × 10[-7]) than those on pristine PS (1.4 × 10[8] CFU mg[-1] and 1.4 × 10[-8], respectively). Moreover, erythromycin at 0.1 and 1.0 mg L[-1] significantly (p < 0.05) promoted the formation and resistance mutation of biofilm on both pristine and UV-aged PS. DNA sequencing results confirmed that the biofilm resistance was attributed to point mutations in rpoB segment of the bacterial genome. qPCR results demonstrated that both UV aging and erythromycin repressed the expression levels of a global regulator rpoS in biofilm bacteria, as well as two DNA mismatch repair genes mutS and uvrD, which was likely to contribute to increased resistance mutation frequency.},
}

@article {pmid38675162,
year = {2024},
author = {Hałasa, R and Turecka, K and Mizerska, U and Krauze-Baranowska, M},
title = {Anti-Helicobacter pylori Biofilm Extracts from Rubus idaeus and Rubus occidentalis.},
journal = {Pharmaceutics},
volume = {16},
number = {4},
pages = {},
pmid = {38675162},
issn = {1999-4923},
abstract = {Helicobacter pylori infections are still an important health problem and are directly related to the development of gastric ulcer, gastric adenocarcinoma, mucosal lymphoid tissue lymphoma, and diabetes. At the same time, the number of substances/drugs effective against these bacteria is limited due to increasing resistance. Raw plant materials from various species of the Rubus genus-fruits and shoots-have shown antimicrobial activity in numerous studies against different bacteria, including H. pylori in a planktonic form. Research carried out on a model using fragments of intravenous infusions and triphenyl tetrazolium chloride (TTC) as a dye showed that the shoot extract of Rubus idaeus 'Willamette', the fruit extract of R. idaeus 'Poranna Rosa', R. idaeus and R. idaeus 'Laszka', and R. occidentalis Litacz' prevent the formation of biofilm by H. pylori. Active concentrations inhibiting biofilm formation were 6.65 mg/mL for shoots and 16.65 mg/mL for fruits. However, in the resulting biofilm, the extract from the shoots of R. idaeus 'Willamette' and the fruit of R. idaeus 'Poranna Rosa' at a concentration of 16.65 mg/mL was active against living bacteria, and the remaining extracts showed such activity at a concentration of 33.3 mg/mL. In studies on the interaction of the extract with antibiotics on biofilm, the extract from the shoots of R. idaeus 'Willamette' showed synergy with doxycycline and levofloxacin, additivity with amoxicillin and clarithromycin, and neutrality with metronidazole. H. pylori biofilm research was carried out in a newly elaborated research model-culture on fragments of intravenous infusions with the addition of TTC as a marker of living bacterial cells. The research results may constitute the basis for the development of new combination therapies for the treatment of H. pylori infections, including its resistant strains. The proposed new biofilm research model, which is cheap and effective, may allow testing of new substances that are potentially more effective against H. pylori and other biofilm-forming bacterial strains.},
}

@article {pmid38675139,
year = {2024},
author = {Wultańska, D and Piotrowski, M and Pituch, H},
title = {Antimicrobial Effects of Some Natural Products on Adhesion and Biofilm Inhibition of Clostridioides difficile.},
journal = {Pharmaceutics},
volume = {16},
number = {4},
pages = {},
pmid = {38675139},
issn = {1999-4923},
support = {2019/03/X/NZ6/01445//National Science Center/ ; },
abstract = {Understanding the potential antimicrobial properties of natural compounds and their impacts on Clostridioides difficile virulence factors may aid in developing alternative strategies for preventing and treating C. difficile infections (CDI). In this study, we investigated the bactericidal effects of ginger oil (GO), peppermint oil (PO), curcumin (CU), cinnamon aldehyde (CI), and trans-cinnamaldehyde (TCI) on the adhesion and biofilm disruption of C. difficile. We used three reference and five clinical C. difficile strains of different ribotypes. The bactericidal activity was assessed using the broth microdilution method. The adhesion was evaluated using human epithelial cell lines, and biofilm formation was visualized by confocal laser scanning microscopy. All tested strains exhibited susceptibility to CU, with minimum inhibitory concentration (MIC) values ranging from 128 µg/mL to 2048 µg/mL. Similarly, all strains were susceptible to CI and TCI, with MIC values ranging from 6.25% (v/v) to 25% (v/v). Most of the tested substances reduced the adhesion of C. difficile strains, while two tested strains showed significantly higher adhesion when co-incubated with the tested substances. Similar observations were made for biofilm formation, with observed density and morphology varied depending on the strain. In conclusion, the tested products demonstrated bactericidal activity and reduced the adhesion of C. difficile strains. They may be considered for further studies as potential antimicrobial agents targeting biofilm-related infections.},
}

@article {pmid38674728,
year = {2024},
author = {Di Domenico, EG and Oliva, A and Guembe, M},
title = {Biofilm-Related Infections in Healthcare: Moving towards New Horizons.},
journal = {Microorganisms},
volume = {12},
number = {4},
pages = {},
pmid = {38674728},
issn = {2076-2607},
abstract = {In this Special Issue, titled "Biofilm-Related Infections in Healthcare", we have reported considerable progress in understanding the physiology and pathology of biofilms [...].},
}

@article {pmid38674703,
year = {2024},
author = {Kispert, S and Liguori, M and Velikaneye, C and Qiu, C and Wang, S and Zhang, N and Gu, H},
title = {Role of Staphylococcus aureus's Buoyant Density in the Development of Biofilm Associated Antibiotic Susceptibility.},
journal = {Microorganisms},
volume = {12},
number = {4},
pages = {},
doi = {10.3390/microorganisms12040759},
pmid = {38674703},
issn = {2076-2607},
support = {80NSSC20M0129//Connecticut Space Grant College Consortium/ ; },
abstract = {Biofilms are clusters of microorganisms that form at various interfaces, including those between air and liquid or liquid and solid. Due to their roles in enhancing wastewater treatment processes, and their unfortunate propensity to cause persistent human infections through lowering antibiotic susceptibility, understanding and managing bacterial biofilms is of paramount importance. A pivotal stage in biofilm development is the initial bacterial attachment to these interfaces. However, the determinants of bacterial cell choice in colonizing an interface first and heterogeneity in bacterial adhesion remain elusive. Our research has unveiled variations in the buoyant density of free-swimming Staphylococcus aureus cells, irrespective of their growth phase. Cells with a low cell buoyant density, characterized by fewer cell contents, exhibited lower susceptibility to antibiotic treatments (100 μg/mL vancomycin) and favored biofilm formation at air-liquid interfaces. In contrast, cells with higher cell buoyant density, which have richer cell contents, were more vulnerable to antibiotics and predominantly formed biofilms on liquid-solid interfaces when contained upright. Cells with low cell buoyant density were not able to revert to a more antibiotic sensitive and high cell buoyant density phenotype. In essence, S. aureus cells with higher cell buoyant density may be more inclined to adhere to upright substrates.},
}

@article {pmid38674628,
year = {2024},
author = {Bereanu, AS and Vintilă, BI and Bereanu, R and Codru, IR and Hașegan, A and Olteanu, C and Săceleanu, V and Sava, M},
title = {TiO2 Nanocomposite Coatings and Inactivation of Carbapenemase-Producing Klebsiella Pneumoniae Biofilm-Opportunities and Challenges.},
journal = {Microorganisms},
volume = {12},
number = {4},
pages = {},
doi = {10.3390/microorganisms12040684},
pmid = {38674628},
issn = {2076-2607},
abstract = {The worldwide increase of multidrug-resistant Gram-negative bacteria is a global threat. The emergence and global spread of Klebsiella pneumoniae carbapenemase- (KPC-) producing Klebsiella pneumoniae represent a particular concern. This pathogen has increased resistance and abilities to persist in human reservoirs, in hospital environments, on medical devices, and to generate biofilms. Mortality related to this microorganism is high among immunosuppressed oncological patients and those with multiple hospitalizations and an extended stay in intensive care. There is a severe threat posed by the ability of biofilms to grow and resist antibiotics. Various nanotechnology-based strategies have been studied and developed to prevent and combat serious health problems caused by biofilm infections. The aim of this review was to evaluate the implications of nanotechnology in eradicating biofilms with KPC-producing Klebsiella pneumoniae, one of the bacteria most frequently associated with nosocomial infections in intensive care units, including in our department, and to highlight studies presenting the potential applicability of TiO2 nanocomposite materials in hospital practice. We also described the frequency of the presence of bacterial biofilms on medical surfaces, devices, and equipment. TiO2 nanocomposite coatings are one of the best long-term options for antimicrobial efficacy due to their biocompatibility, stability, corrosion resistance, and low cost; they find their applicability in hospital practice due to their critical antimicrobial role for surfaces and orthopedic and dental implants. The International Agency for Research on Cancer has recently classified titanium dioxide nanoparticles (TiO2 NPs) as possibly carcinogenic. Currently, there is an interest in the ecological, non-toxic synthesis of TiO2 nanoparticles via biological methods. Biogenic, non-toxic nanoparticles have remarkable properties due to their biocompatibility, stability, and size. Few studies have mentioned the use of nanoparticle-coated surfaces as antibiofilm agents. A literature review was performed to identify publications related to KPC-producing Klebsiella pneumoniae biofilms and antimicrobial TiO2 photocatalytic nanocomposite coatings. There are few reviews on the antibacterial and antibiofilm applications of TiO2 photocatalytic nanocomposite coatings. TiO2 nanoparticles demonstrated marked antibiofilm activity, but being nano in size, these nanoparticles can penetrate cell membranes and may initiate cellular toxicity and genotoxicity. Biogenic TiO2 nanoparticles obtained via green, ecological technology have less applicability but are actively investigated.},
}

@article {pmid38674584,
year = {2024},
author = {Iaconis, A and De Plano, LM and Caccamo, A and Franco, D and Conoci, S},
title = {Anti-Biofilm Strategies: A Focused Review on Innovative Approaches.},
journal = {Microorganisms},
volume = {12},
number = {4},
pages = {},
doi = {10.3390/microorganisms12040639},
pmid = {38674584},
issn = {2076-2607},
abstract = {Biofilm (BF) can give rise to systemic infections, prolonged hospitalization times, and, in the worst case, death. This review aims to provide an overview of recent strategies for the prevention and destruction of pathogenic BFs. First, the main phases of the life cycle of BF and maturation will be described to identify potential targets for anti-BF approaches. Then, an approach acting on bacterial adhesion, quorum sensing (QS), and the extracellular polymeric substance (EPS) matrix will be introduced and discussed. Finally, bacteriophage-mediated strategies will be presented as innovative approaches against BF inhibition/destruction.},
}

@article {pmid38674531,
year = {2024},
author = {Mahavy, CE and Razanatseheno, AJ and Mol, A and Ngezahayo, J and Duez, P and El Jaziri, M and Baucher, M and Rasamiravaka, T},
title = {Edible Medicinal Guava Fruit (Psidium guajava L.) Are a Source of Anti-Biofilm Compounds against Pseudomonas aeruginosa.},
journal = {Plants (Basel, Switzerland)},
volume = {13},
number = {8},
pages = {},
doi = {10.3390/plants13081122},
pmid = {38674531},
issn = {2223-7747},
abstract = {Psidium guajava is one of the most common edible medicinal plants frequently used in Malagasy traditional medicine to treat gastrointestinal infections. In order to evaluate their probable antibacterial activities, three organic extracts (successive extractions by hexane, dichloromethane, and ethanol) of ripe guava fruits were assessed for their bactericidal and anti-virulence properties against P. aeruginosa PAO1. Although these three extracts have shown no direct antibacterial activity (MIC of 1000 µg/mL) and, at the non-bactericidal concentration of 100 µg/mL, no impact on the production of major P. aeruginosa PAO1 virulence factors (pyocyanin and rhamnolipids), the hexane and dichloromethane extracts showed significant anti-biofilm properties and the dichloromethane extract disrupted the P. aeruginosa PAO1 swarming motility. Bioguided fractionation of the dichloromethane extract led to the isolation and identification of lycopene and β-sitosterol-β-D-glucoside as major anti-biofilm compounds. Interestingly, both compounds disrupt P. aeruginosa PAO1 biofilm formation and maintenance with IC50 of 1383 µM and 131 µM, respectively. More interestingly, both compounds displayed a synergistic effect with tobramycin with a two-fold increase in its effectiveness in killing biofilm-encapsulated P. aeruginosa PAO1. The present study validates the traditional uses of this edible medicinal plant, indicating the therapeutic effectiveness of guava fruits plausibly through the presence of these tri- and tetraterpenoids, which deserve to be tested against pathogens generally implicated in diarrhea.},
}

@article {pmid38673451,
year = {2024},
author = {Pardo, A and Fiorini, V and Zangani, A and Faccioni, P and Signoriello, A and Albanese, M and Lombardo, G},
title = {Topical Agents in Biofilm Disaggregation: A Systematic Review and Meta-Analysis.},
journal = {Journal of clinical medicine},
volume = {13},
number = {8},
pages = {},
doi = {10.3390/jcm13082179},
pmid = {38673451},
issn = {2077-0383},
abstract = {Background: to evaluate the effectiveness of different topical agents in biofilm disaggregation during non-surgical periodontal therapy. Methods: the search strategy was conducted according to the PRISMA 2020 on Pubmed, Cochrane Library, Scopus, and Web of Science, and it was registered in PROSPERO, ID: CRD42023474232. It included studies comparing non-surgical periodontal therapy (NSPT) with and without the application of topical agents for biofilm disruption. A risk of bias analysis, a qualitative analysis, and a quantitative analysis were performed. Results: out of 1583 records, 11 articles were included: 10 randomized clinical trials and one retrospective analysis. The total number of participants considered in the 11 articles included in the study was 386. The primary outcomes were probing pocket depth (PPD), clinical attachment level (CAL), and bleeding indices. The secondary outcomes were plaque indices, gingival recessions, and microbiological parameters. The meta-analysis revealed the following: [Weighted mean difference (WMD): -0.37; 95% confidence interval (CI) (-0.62, -0.12), heterogeneity I[2]: 79%, statistical significance p = 0.004]. Conclusions: the meta-analysis of probing pocket depth reduction (PPD) between baseline and follow-up at 3-6 months showed a statistically significant result in favor of sulfonated phenolics gel. The scientific evidence is still limited and heterogeneous; further randomized clinical trials are required.},
}

@article {pmid38671777,
year = {2024},
author = {Panio, A and Ionescu, AC and La Ferla, B and Zoia, L and Savadori, P and Tartaglia, GM and Brambilla, E},
title = {Cellulose Nanocrystals Show Anti-Adherent and Anti-Biofilm Properties against Oral Microorganisms.},
journal = {Bioengineering (Basel, Switzerland)},
volume = {11},
number = {4},
pages = {},
doi = {10.3390/bioengineering11040355},
pmid = {38671777},
issn = {2306-5354},
abstract = {Cellulose nanocrystals (CNCs) are cellulose-derived nanomaterials that can be easily obtained, e.g., from vegetable waste produced by circular economies. They show promising antimicrobial activity and an absence of side effects and toxicity. This study investigated the ability of CNCs to reduce microbial adherence and biofilm formation using in vitro microbiological models reproducing the oral environment. Microbial adherence by microbial strains of oral interest, Streptococcus mutans and Candida albicans, was evaluated on the surfaces of salivary pellicle-coated enamel disks in the presence of different aqueous solutions of CNCs. The anti-biofilm activity of the same CNC solutions was tested against S. mutans and an oral microcosm model based on mixed plaque inoculum using a continuous-flow bioreactor. Results showed the excellent anti-adherent activity of the CNCs against the tested strains from the lowest concentration tested (0.032 wt. %, p < 0.001). Such activity was significantly higher against S. mutans than against C. albicans (p < 0.01), suggesting a selective anti-adherent activity against pathogenic strains. At the same time, there was a minimal, albeit significant, anti-biofilm activity (0.5 and 4 wt. % CNC solution for S. mutans and oral microcosm, respectively, p = 0.01). This makes CNCs particularly interesting as anticaries agents, encouraging their use in the oral field.},
}

@article {pmid38669236,
year = {2024},
author = {Kuper, TJ and Islam, MM and Peirce-Cottler, SM and Papin, JA and Ford, RM},
title = {Spatial transcriptome-guided multi-scale framework connects P. aeruginosa metabolic states to oxidative stress biofilm microenvironment.},
journal = {PLoS computational biology},
volume = {20},
number = {4},
pages = {e1012031},
pmid = {38669236},
issn = {1553-7358},
mesh = {*Biofilms/growth & development ; *Pseudomonas aeruginosa/genetics/metabolism/physiology ; *Oxidative Stress/physiology ; *Transcriptome/genetics ; *Models, Biological ; Computational Biology ; Metabolic Networks and Pathways/genetics ; Nitric Oxide/metabolism ; Computer Simulation ; Denitrification ; },
abstract = {With the generation of spatially resolved transcriptomics of microbial biofilms, computational tools can be used to integrate this data to elucidate the multi-scale mechanisms controlling heterogeneous biofilm metabolism. This work presents a Multi-scale model of Metabolism In Cellular Systems (MiMICS) which is a computational framework that couples a genome-scale metabolic network reconstruction (GENRE) with Hybrid Automata Library (HAL), an existing agent-based model and reaction-diffusion model platform. A key feature of MiMICS is the ability to incorporate multiple -omics-guided metabolic models, which can represent unique metabolic states that yield different metabolic parameter values passed to the extracellular models. We used MiMICS to simulate Pseudomonas aeruginosa regulation of denitrification and oxidative stress metabolism in hypoxic and nitric oxide (NO) biofilm microenvironments. Integration of P. aeruginosa PA14 biofilm spatial transcriptomic data into a P. aeruginosa PA14 GENRE generated four PA14 metabolic model states that were input into MiMICS. Characteristic of aerobic, denitrification, and oxidative stress metabolism, the four metabolic model states predicted different oxygen, nitrate, and NO exchange fluxes that were passed as inputs to update the agent's local metabolite concentrations in the extracellular reaction-diffusion model. Individual bacterial agents chose a PA14 metabolic model state based on a combination of stochastic rules, and agents sensing local oxygen and NO. Transcriptome-guided MiMICS predictions suggested microscale denitrification and oxidative stress metabolic heterogeneity emerged due to local variability in the NO biofilm microenvironment. MiMICS accurately predicted the biofilm's spatial relationships between denitrification, oxidative stress, and central carbon metabolism. As simulated cells responded to extracellular NO, MiMICS revealed dynamics of cell populations heterogeneously upregulating reactions in the denitrification pathway, which may function to maintain NO levels within non-toxic ranges. We demonstrated that MiMICS is a valuable computational tool to incorporate multiple -omics-guided metabolic models to mechanistically map heterogeneous microbial metabolic states to the biofilm microenvironment.},
}

*Biofilms/growth & development
*Pseudomonas aeruginosa/genetics/metabolism/physiology
*Oxidative Stress/physiology
*Transcriptome/genetics
*Models, Biological
Computational Biology
Metabolic Networks and Pathways/genetics
Nitric Oxide/metabolism
Computer Simulation
Denitrification

@article {pmid38669142,
year = {2024},
author = {Kennelly, C and Tran, P and Prindle, A},
title = {Environmental purines decrease Pseudomonas aeruginosa biofilm formation by disrupting c-di-GMP metabolism.},
journal = {Cell reports},
volume = {43},
number = {5},
pages = {114154},
doi = {10.1016/j.celrep.2024.114154},
pmid = {38669142},
issn = {2211-1247},
abstract = {Cyclic di-guanosine monophosphate (c-di-GMP) is a bacterial second messenger that governs the lifestyle switch between planktonic and biofilm states. While substantial investigation has focused on the proteins that produce and degrade c-di-GMP, less attention has been paid to the potential for metabolic control of c-di-GMP signaling. Here, we show that micromolar levels of specific environmental purines unexpectedly decrease c-di-GMP and biofilm formation in Pseudomonas aeruginosa. Using a fluorescent genetic reporter, we show that adenosine and inosine decrease c-di-GMP even when competing purines are present. We confirm genetically that purine salvage is required for c-di-GMP decrease. Furthermore, we find that (p)ppGpp prevents xanthosine and guanosine from producing an opposing c-di-GMP increase, reinforcing a salvage hierarchy that favors c-di-GMP decrease even at the expense of growth. We propose that purines can act as a cue for bacteria to shift their lifestyle away from the recalcitrant biofilm state via upstream metabolic control of c-di-GMP signaling.},
}

@article {pmid38668646,
year = {2024},
author = {Ding, H and Bai, Y and Luo, W and Li, H and Zhu, C and Zhao, X and Sun, H and Wen, Y and Zhang, W and Zhang, S and Wen, B and Wang, R and Zhang, L and Liu, X and Shen, J and Hu, J and Wang, L and Bai, Y and Liao, C and Wu, Y and Wu, X and Ding, K},
title = {Rhein kills Actinobacillus pleuropneumoniae, reduces biofilm formation, and effectively treats bacterial lung infections in mice.},
journal = {Journal of medical microbiology},
volume = {73},
number = {4},
pages = {},
doi = {10.1099/jmm.0.001826},
pmid = {38668646},
issn = {1473-5644},
mesh = {Animals ; *Anthraquinones/pharmacology/therapeutic use ; *Actinobacillus pleuropneumoniae/drug effects/genetics ; *Anti-Bacterial Agents/pharmacology/therapeutic use ; Mice ; *Actinobacillus Infections/drug therapy/microbiology/veterinary ; Swine ; Disease Models, Animal ; Female ; Drugs, Chinese Herbal/pharmacology/therapeutic use ; Lung/microbiology/pathology ; Swine Diseases/drug therapy/microbiology ; },
abstract = {Background. Actinobacillus pleuropneumoniae, a member of the Pasteurellaceae family, is known for its highly infectious nature and is the primary causative agent of infectious pleuropneumonia in pigs. This disease poses a considerable threat to the global pig industry and leads to substantial economic losses due to reduced productivity, increased mortality rates, and the need for extensive veterinary care and treatment. Due to the emergence of multi-drug-resistant strains, Chinese herbal medicine is considered one of the best alternatives to antibiotics due to its unique mechanism of action and other properties. As a type of Chinese herbal medicine, Rhein has the advantages of a wide antibacterial spectrum and is less likely to develop drug resistance, which can perfectly solve the limitations of current antibacterial treatments.Methods. The killing effect of Rhein on A. pleuropneumoniae was detected by fluorescence quantification of differential expression changes of key genes, and scanning electron microscopy was used to observe the changes in A. pleuropneumoniae status after Rhein treatment. Establishing a mouse model to observe the treatment of Rhein after A. pleuropneumoniae infection.Results. Here, in this study, we found that Rhein had a good killing effect on A. pleuropneumoniae and that the MIC was 25 µg ml[-1]. After 3 h of action, Rhein (4×MIC) completely kills A. pleuropneumoniae and Rhein has good stability. In addition, the treatment with Rhein (1×MIC) significantly reduced the formation of bacterial biofilms. Therapeutic evaluation in a murine model showed that Rhein protects mice from A. pleuropneumoniae and relieves lung inflammation. Quantitative RT-PCR (Quantitative reverse transcription polymerase chain reaction is a molecular biology technique that combines both reverse transcription and polymerase chain reaction methods to quantitatively detect the amount of a specific RNA molecule) results showed that Rhein treatment significantly downregulated the expression of the IL-18 (Interleukin refers to a class of cytokines produced by white blood cells), TNF-α, p65 and p38 genes. Along with the downregulation of genes such as IL-18, it means that Rhein has an inhibitory effect on the expression of these genes, thereby reducing the activation of inflammatory cells and the production of inflammatory mediators. This helps reduce inflammation and protects tissue from further damage.Conclusions. This study reports the activity of Rhein against A. pleuropneumoniae and its mechanism, and reveals the ability of Rhein to treat A. pleuropneumoniae infection in mice, laying the foundation for the development of new drugs for bacterial infections.},
}

Animals
*Anthraquinones/pharmacology/therapeutic use
*Actinobacillus pleuropneumoniae/drug effects/genetics
*Anti-Bacterial Agents/pharmacology/therapeutic use
Mice
*Actinobacillus Infections/drug therapy/microbiology/veterinary
Swine
Disease Models, Animal
Female
Drugs, Chinese Herbal/pharmacology/therapeutic use
Lung/microbiology/pathology
Swine Diseases/drug therapy/microbiology

@article {pmid38668447,
year = {2024},
author = {Son, Y and Jin, YB and Cho, EJ and Park, AR and Flores, RA and Nguyen, BT and Lee, SY and Altanzul, B and Park, KI and Min, W and Kim, WH},
title = {Comparative Analysis of Antibiotic Resistance and Biofilm Characteristics of Two Major Enterococcus Species from Poultry Slaughterhouses in South Korea.},
journal = {Veterinary sciences},
volume = {11},
number = {4},
pages = {},
doi = {10.3390/vetsci11040180},
pmid = {38668447},
issn = {2306-7381},
support = {Specialized Graduate School Support Project for Wildlife Disease Specialists//National Institute of Wildlife Disease Control and Prevention/ ; //Gyeongnam Veterinary Service Laboratory/ ; },
abstract = {The spread of antibiotic-resistant Enterococcus in the poultry industry poses significant public health challenges due to multidrug resistance and biofilm formation. We investigated the antibiotic resistance profiles and biofilm characteristics of E. faecalis and E. faecium isolates from chicken meat in poultry slaughterhouses in South Korea. Ninety-six isolates (forty-eight each of E. faecalis and E. faecium) were collected between March and September 2022. Both species were analyzed using MALDI-TOF, PCR, antibiotic susceptibility testing, and biofilm assays. A high level of multidrug resistance was observed in E. faecalis (95.8%) and E. faecium (93.8%), with E. faecium exhibiting a broader range of resistance, particularly to linezolid (52.1%) and rifampicin (47.9%). All E. faecalis isolates formed biofilm in vitro, showing stronger biofilm formation than E. faecium with a significant difference (p < 0.001) in biofilm strength. Specific genes (cob, ccf, and sprE) were found to be correlated with biofilm strength. In E. faecium isolates, biofilm strength was correlated with resistance to linezolid and rifampicin, while a general correlation between antibiotic resistance and biofilm strength was not established. Through analysis, correlations were noted between antibiotics within the same class, while no general trends were evident in other analyzed factors. This study highlights the public health risks posed by multidrug-resistant enterococci collected from poultry slaughterhouses, emphasizing the complexity of the biofilm-resistance relationship and the need for enhanced control measures.},
}

@article {pmid38668437,
year = {2024},
author = {Fidelis, CE and Orsi, AM and Freu, G and Gonçalves, JL and Santos, MVD},
title = {Biofilm Formation and Antimicrobial Resistance of Staphylococcus aureus and Streptococcus uberis Isolates from Bovine Mastitis.},
journal = {Veterinary sciences},
volume = {11},
number = {4},
pages = {},
doi = {10.3390/vetsci11040170},
pmid = {38668437},
issn = {2306-7381},
abstract = {This study aimed to assess (a) the biofilm producer ability and antimicrobial resistance profiles of Staphylococcus (Staph.) aureus and Streptococcus (Strep.) uberis isolated from cows with clinical mastitis (CM) and subclinical mastitis (SCM), and (b) the association between biofilm producer ability and antimicrobial resistance. We isolated a total of 197 Staph. aureus strains (SCM = 111, CM = 86) and 119 Strep. uberis strains (SCM = 15, CM = 104) from milk samples obtained from 316 cows distributed in 24 dairy herds. Biofilm-forming ability was assessed using the microplate method, while antimicrobial susceptibility was determined using the disk diffusion method against 13 antimicrobials. Among the isolates examined, 57.3% of Staph. aureus and 53.8% of Strep. uberis exhibited the ability to produce biofilm, which was categorized as strong, moderate, or weak. In terms of antimicrobial susceptibility, Staph. aureus isolates displayed resistance to penicillin (92.9%), ampicillin (50.8%), and tetracycline (52.7%). Conversely, Strep. uberis isolates exhibited resistance to penicillin (80.6%), oxacillin (80.6%), and tetracycline (37.8%). However, no significant correlation was found between antimicrobial resistance patterns and biofilm formation ability among the isolates.},
}

@article {pmid38668297,
year = {2024},
author = {Bueno-Silva, B and Parma-Garcia, J and Frigo, L and Suárez, LJ and Macedo, TT and Uyeda, FH and Melo, MARDC and Sacco, R and Mourão, CF and Feres, M and Shibli, JA and Figueiredo, LC},
title = {Antimicrobial Activity of Methylene Blue Associated with Photodynamic Therapy: In Vitro Study in Multi-Species Oral Biofilm.},
journal = {Pathogens (Basel, Switzerland)},
volume = {13},
number = {4},
pages = {},
doi = {10.3390/pathogens13040342},
pmid = {38668297},
issn = {2076-0817},
support = {# 311368/2019-0 CNPq//National Council for Scientific and Technological Development/ ; #001 CAPES//Coordination for the Improvement of Higher Education Personel,/ ; },
abstract = {The control of infectious diseases caused by biofilms is a continuing challenge for researchers due to the complexity of their microbial structures and therapeutic implications. Photodynamic therapy as an adjunctive anti-infective treatment has been described as a possible valid approach but has not been tested in polymicrobial biofilm models. This study evaluated the effect of photodynamic therapy in vitro with methylene blue (MB) 0.01% and red LEDs (λ = 660 nm, power density ≈ 330 mW/cm[2], 2 mm distance from culture) on the metabolic activity and composition of a multispecies subgingival biofilm. Test Groups LED and MB + LED showed a more significant reduction in metabolic activity than the non-LED application group (~50 and 55%, respectively). Groups LED and MB equally affected (more than 80%) the total bacterial count in biofilms. No differences were noted in the bacterial biofilm composition between the groups. In vitro LED alone or the MB + LED combination reduced the metabolic activity of bacteria in polymicrobial biofilms and the total subgingival biofilm count.},
}

@article {pmid38668282,
year = {2024},
author = {Aljaafari, HAS and Abdulwahhab, NI and Nuxoll, E},
title = {Antibiotic Augmentation of Thermal Eradication of Staphylococcus epidermidis Biofilm Infections.},
journal = {Pathogens (Basel, Switzerland)},
volume = {13},
number = {4},
pages = {},
doi = {10.3390/pathogens13040327},
pmid = {38668282},
issn = {2076-0817},
support = {18IPA34170108//American Heart Association/ ; CBET-1133297//National Science Foundation/ ; },
abstract = {Staphylococcus epidermidis is a major contributor to bacterial infections on medical implants, currently treated by surgical removal of the device and the surrounding infected tissue at considerable morbidity and expense. In situ hyperthermia is being investigated as a non-invasive means of mitigating these bacterial biofilm infections, but minimizing damage to the surrounding tissue requires augmenting the thermal shock with other approaches such as antibiotics and discerning the minimum shock required to eliminate the biofilm. S. epidermidis biofilms were systematically shocked at a variety of temperatures (50-80 °C) and durations (1-10 min) to characterize their thermal susceptibility and compare it to other common nosocomial pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. Biofilms were also exposed to three classes of antibiotics (ciprofloxacin, tobramycin and erythromycin) separately at concentrations ranging from 0 to 128 μg mL[-1] to evaluate their impact on the efficacy of thermal shock and the subsequent potential regrowth of the biofilm. S. epidermidis biofilms were shown to be more thermally susceptible to hyperthermia than other common bacterial pathogens. All three antibiotics substantially decreased the duration and/or temperature needed to eliminate the biofilms, though this augmentation did not meet the criteria of synergism immediately following thermal shock. Subsequent reincubation, however, revealed strong synergism on a longer timescale.},
}

@article {pmid38668281,
year = {2024},
author = {Olayiwola, B and O'Neill, F and Frewen, C and Kavanagh, DF and O'Hara, R and O'Neill, L},
title = {Cold Plasma Deposition of Tobramycin as an Approach to Localized Antibiotic Delivery to Combat Biofilm Formation.},
journal = {Pathogens (Basel, Switzerland)},
volume = {13},
number = {4},
pages = {},
doi = {10.3390/pathogens13040326},
pmid = {38668281},
issn = {2076-0817},
support = {EBPPG/2021/105//Irish Research Council/ ; },
abstract = {Hospital-acquired infections (HAIs) remain a significant factor in hospitals, with implant surfaces often becoming contaminated by highly resistant strains of bacteria. Recent studies have shown that electrical plasma discharges can reduce bacterial load on surfaces, and this approach may help augment traditional antibiotic treatments. To investigate this, a cold atmospheric plasma was used to deposit tobramycin sulphate onto various surfaces, and the bacterial growth rate of K. pneumoniae in its planktonic and biofilm form was observed to probe the interactions between the plasma discharge and the antibiotic and to determine if there were any synergistic effects on the growth rate. The plasma-deposited tobramycin was still active after passing through the plasma field and being deposited onto titanium or polystyrene. This led to the significant inhibition of K. pneumoniae, with predictable antibiotic dose dependence. Separate studies have shown that the plasma treatment of the biofilm had a weak antimicrobial effect and reduced the amount of biofilm by around 50%. Combining a plasma pre-treatment on exposed biofilm followed by deposited tobramycin application proved to be somewhat effective in further reducing biofilm growth. The plasma discharge pre-treatment produced a further reduction in the biofilm load beyond that expected from just the antibiotic alone. However, the effect was not additive, and the results suggest that a complex interaction between plasma and antibiotic may be at play, with increasing plasma power producing a non-linear effect. This study may contribute to the treatment of infected surgical sites, with the coating of biomaterial surfaces with antibiotics reducing overall antibiotic use through the targeted delivery of therapeutics.},
}

@article {pmid38668275,
year = {2024},
author = {Araújo, D and Silva, AR and Fernandes, R and Serra, P and Barros, MM and Campos, AM and Oliveira, R and Silva, S and Almeida, C and Castro, J},
title = {Emerging Approaches for Mitigating Biofilm-Formation-Associated Infections in Farm, Wild, and Companion Animals.},
journal = {Pathogens (Basel, Switzerland)},
volume = {13},
number = {4},
pages = {},
doi = {10.3390/pathogens13040320},
pmid = {38668275},
issn = {2076-0817},
support = {LA/P/0045/2020//Fundação para a Ciência e Tecnologia/ ; UIDB/00511/2020//Fundação para a Ciência e Tecnologia/ ; UIDB/04469/2020//Fundação para a Ciência e Tecnologia/ ; UIDB/04033/2020//Fundação para a Ciência e Tecnologia/ ; UIDP/04033/2020//Fundação para a Ciência e Tecnologia/ ; https://doi.org/10.54499/2022.06886.CEECIND/CP1737/CT0001//Fundação para a Ciência e Tecnologia/ ; },
abstract = {The importance of addressing the problem of biofilms in farm, wild, and companion animals lies in their pervasive impact on animal health and welfare. Biofilms, as resilient communities of microorganisms, pose a persistent challenge in causing infections and complicating treatment strategies. Recognizing and understanding the importance of mitigating biofilm formation is critical to ensuring the welfare of animals in a variety of settings, from farms to the wild and companion animals. Effectively addressing this issue not only improves the overall health of individual animals, but also contributes to the broader goals of sustainable agriculture, wildlife conservation, and responsible pet ownership. This review examines the current understanding of biofilm formation in animal diseases and elucidates the complex processes involved. Recognizing the limitations of traditional antibiotic treatments, mechanisms of resistance associated with biofilms are explored. The focus is on alternative therapeutic strategies to control biofilm, with illuminating case studies providing valuable context and practical insights. In conclusion, the review highlights the importance of exploring emerging approaches to mitigate biofilm formation in animals. It consolidates existing knowledge, highlights gaps in understanding, and encourages further research to address this critical facet of animal health. The comprehensive perspective provided by this review serves as a foundation for future investigations and interventions to improve the management of biofilm-associated infections in diverse animal populations.},
}

@article {pmid38668260,
year = {2024},
author = {Silva, A and Silva, V and Dapkevicius, MLE and Azevedo, M and Cordeiro, R and Pereira, JE and Valentão, P and Falco, V and Igrejas, G and Caniça, M and Poeta, P},
title = {Unveiling Antibiotic Resistance, Clonal Diversity, and Biofilm Formation in E. coli Isolated from Healthy Swine in Portugal.},
journal = {Pathogens (Basel, Switzerland)},
volume = {13},
number = {4},
pages = {},
doi = {10.3390/pathogens13040305},
pmid = {38668260},
issn = {2076-0817},
abstract = {Escherichia coli, a commensal microorganism found in the gastrointestinal tract of human and animal hosts, plays a central role in agriculture and public health. Global demand for animal products has promoted increased pig farming, leading to growing concerns about the prevalence of antibiotic-resistant E. coli strains in swine populations. It should be noted that a significant portion of antibiotics deployed in swine management belong to the critically important antibiotics (CIA) class, which should be reserved for human therapeutic applications. This study aimed to characterize the prevalence of antibiotic resistance, genetic diversity, virulence characteristics, and biofilm formation of E. coli strains in healthy pigs from various farms across central Portugal. Our study revealed high levels of antibiotic resistance, with resistance to tetracycline, ampicillin, tobramycin, and trimethoprim-sulfamethoxazole. Multidrug resistance is widespread, with some strains resistant to seven different antibiotics. The ampC gene, responsible for broad-spectrum resistance to cephalosporins and ampicillin, was widespread, as were genes associated with resistance to sulfonamide and beta-lactam antibiotics. The presence of high-risk clones, such as ST10, ST101, and ST48, are a concern due to their increased virulence and multidrug resistance profiles. Regarding biofilm formation, it was observed that biofilm-forming capacity varied significantly across different compartments within pig farming environments. In conclusion, our study highlights the urgent need for surveillance and implementation of antibiotic management measures in the swine sector. These measures are essential to protect public health, ensure animal welfare, and support the swine industry in the face of the growing global demand for animal products.},
}

@article {pmid38667020,
year = {2024},
author = {El Haj, C and Agustí, E and Benavent, E and Soldevila-Boixader, L and Rigo-Bonnin, R and Tubau, F and Torrejón, B and Esteban, J and Murillo, O},
title = {Comparative Efficacy of Continuous Ceftazidime Infusion vs. Intermittent Bolus against In Vitro Ceftazidime-Susceptible and -Resistant Pseudomonas aeruginosa Biofilm.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {4},
pages = {},
doi = {10.3390/antibiotics13040344},
pmid = {38667020},
issn = {2079-6382},
support = {PI19/00965//Instituto de Salud Carlos III/ ; },
abstract = {Background: As the anti-biofilm pharmacokinetic/pharmacodynamic (PK/PD) properties of antibiotics are not well-defined, we have evaluated the PK/PD indices for different regimens of ceftazidime (CAZ; with/without colistin) against Pseudomonas aeruginosa biofilm. Methods: We have used the Center for Disease Control and Prevention Biofilm Reactor with two susceptible (PAO1 and HUB-PAS) and one resistant (HUB-XDR) strains of P. aeruginosa. The regimens were CAZ monotherapies (mimicking a human dose of 2 g/8 h, CAZ-IB; 6 g/daily as continuous infusion at 50 mg/L, CAZ-CI50; and 9 g/daily at 70 mg/L, CAZ-CI70) and CAZ-colistin combinations. Efficacy was correlated with the CAZ PK/PD parameters. Results: CAZ-CI70 was the most effective monotherapy against CAZ-susceptible strains (Δlog CFU/mL 54-0 h = -4.15 ± 0.59 and -3.05 ± 0.5 for HUB-PAS and PAO1, respectively; p ≤ 0.007 vs. other monotherapies), and adding colistin improved the efficacy over CAZ monotherapy. CAZ monotherapies were ineffective against the HUB-XDR strain, and CAZ-CI50 plus colistin achieved higher efficacy than CAZ-IB with colistin. The PK/PD index that correlated best with anti-biofilm efficacy was fAUC0-24h/MIC (r[2] = 0.78). Conclusions: CAZ exhibited dose-dependent anti-biofilm killing against P. aeruginosa, which was better explained by the fAUC0-24h/MIC index. CAZ-CI provided benefits compared to CAZ-IB, particularly when using higher doses and together with colistin. CAZ monotherapies were ineffective against the CAZ-resistant strain, independently of the optimized strategy and only CAZ-CI plus colistin appeared useful for clinical practice.},
}

@article {pmid38666994,
year = {2024},
author = {Mazzantini, D and Massimino, M and Calvigioni, M and Rossi, V and Celandroni, F and Lupetti, A and Batoni, G and Ghelardi, E},
title = {Anti-Staphylococcal Biofilm Effects of a Liposome-Based Formulation Containing Citrus Polyphenols.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {4},
pages = {},
doi = {10.3390/antibiotics13040318},
pmid = {38666994},
issn = {2079-6382},
support = {PNRR THE-Tuscany Health Ecosystem; Spoke 7-Innovating Translational Medicine-Sub-project 5-Innovative models for management of infections caused by antibiotic-resistant bacteria (Project code: ECS00000017; CUP I53C22000780001)//European Commission/ ; },
abstract = {Biofilms are surface-associated microbial communities embedded in a matrix that is almost impenetrable to antibiotics, thus constituting a critical health threat. Biofilm formation on the cornea or ocular devices can lead to serious and difficult-to-treat infections. Nowadays, natural molecules with antimicrobial activity and liposome-based delivery systems are proposed as anti-biofilm candidates. In this study, the anti-biofilm activity of a formulation containing citrus polyphenols encapsulated in liposomes was evaluated against Staphylococcus aureus and Staphylococcus epidermidis, the most common agents in ocular infections. The formulation activity against planktonic staphylococci was tested by broth microdilution and sub-inhibitory concentrations were used to evaluate the effect on biofilm formation using the crystal violet (CV) assay. The eradicating effect of the preparation on mature biofilms was investigated by the CV assay, plate count, and confocal laser scanning microscopy. The product was bactericidal against staphylococci at a dilution of 1:2 or 1:4 and able to reduce biofilm formation even if diluted at 1:64. The formulation also had the ability to reduce the biomass of mature biofilms without affecting the number of cells, suggesting activity on the extracellular matrix. Overall, our results support the application of the used liposome-encapsulated polyphenols as an anti-biofilm strategy to counter biofilm-associated ocular infections.},
}

@article {pmid38666986,
year = {2024},
author = {Sumlu, E and Aydin, M and Korucu, EN and Alyar, S and Nsangou, AM},
title = {Artemisinin May Disrupt Hyphae Formation by Suppressing Biofilm-Related Genes of Candida albicans: In Vitro and In Silico Approaches.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {4},
pages = {},
doi = {10.3390/antibiotics13040310},
pmid = {38666986},
issn = {2079-6382},
abstract = {This study aimed to assess the antifungal and antibiofilm efficacy of artemisinin against Candida (C.) species, analyze its impact on gene expression levels within C. albicans biofilms, and investigate the molecular interactions through molecular docking. The antifungal efficacy of artemisinin on a variety of Candida species, including fluconazole-resistant and -susceptible species, was evaluated by the microdilution method. The effect of artemisinin on C. albicans biofilm formation was investigated by MTT and FESEM. The mRNA expression of the genes related to biofilm was analyzed by qRT-PCR. In addition, molecular docking analysis was used to understand the interaction between artemisinin and C. albicans at the molecular level with RAS1-cAMP-EFG1 and EFG1-regulated genes. Artemisinin showed higher sensitivity against non-albicans Candida strains. Furthermore, artemisinin was strongly inhibitory against C. albicans biofilms at 640 µg/mL. Artemisinin downregulated adhesion-related genes ALS3, HWP1, and ECE1, hyphal development genes UME6 and HGC1, and hyphal CAMP-dependent protein kinase regulators CYR1, RAS1, and EFG1. Furthermore, molecular docking analysis revealed that artemisinin and EFG1 had the highest affinity, followed by UME6. FESEM analysis showed that the fluconazole- and artemisinin-treated groups exhibited a reduced hyphal network, unusual surface bulges, and the formation of pores on the cell surfaces. Our study suggests that artemisinin may have antifungal potential and showed a remarkable antibiofilm activity by significantly suppressing adhesion and hyphal development through interaction with key proteins involved in biofilm formation, such as EFG1.},
}

@article {pmid38666917,
year = {2024},
author = {Vang, D and Moreira-Souza, ACA and Zusman, N and Moncada, G and Matshik Dakafay, H and Asadi, H and Ojcius, DM and Almeida-da-Silva, CLC},
title = {Frankincense (Boswellia serrata) Extract Effects on Growth and Biofilm Formation of Porphyromonas gingivalis, and Its Intracellular Infection in Human Gingival Epithelial Cells.},
journal = {Current issues in molecular biology},
volume = {46},
number = {4},
pages = {2991-3004},
doi = {10.3390/cimb46040187},
pmid = {38666917},
issn = {1467-3045},
support = {Intramural funds//University of the Pacific/ ; Start-Up Funds (D30059 - Activity 101)//University of the Pacific/ ; },
abstract = {Frankincense is produced by Boswellia trees, which can be found throughout the Middle East and parts of Africa and Asia. Boswellia serrata extract has been shown to have anti-cancer, anti-inflammatory, and antimicrobial effects. Periodontitis is an oral chronic inflammatory disease that affects nearly half of the US population. We investigated the antimicrobial effects of B. serrata extract on two oral pathogens associated with periodontitis. Using the minimum inhibitory concentration and crystal violet staining methods, we demonstrated that Porphyromonas gingivalis growth and biofilm formation were impaired by treatment with B. serrata extracts. However, the effects on Fusobacterium nucleatum growth and biofilm formation were not significant. Using quantification of colony-forming units and microscopy techniques, we also showed that concentrations of B. serrata that were not toxic for host cells decreased intracellular P. gingivalis infection in human gingival epithelial cells. Our results show antimicrobial activity of a natural product extracted from Boswellia trees (B. serrata) against periodontopathogens. Thus, B. serrata has the potential for preventing and/or treating periodontal diseases. Future studies will identify the molecular components of B. serrata extracts responsible for the beneficial effects.},
}

@article {pmid38663906,
year = {2024},
author = {Zhu, J and Fan, X and Ding, L and Song, T},
title = {Idiopathic gingival fibromatosis and primary analysis of dominant bacteria in subgingival biofilm: a case report.},
journal = {The Journal of international medical research},
volume = {52},
number = {4},
pages = {3000605241245302},
doi = {10.1177/03000605241245302},
pmid = {38663906},
issn = {1473-2300},
mesh = {Humans ; *Biofilms/growth & development ; *Fibromatosis, Gingival/diagnosis/pathology/microbiology ; *Gingiva/microbiology/pathology ; Female ; Adult ; Male ; Bacteria/isolation & purification ; Gingivectomy/methods ; },
abstract = {Idiopathic gingival fibromatosis (IGF), a rare fibroproliferative disease of unknown etiology, affects gingival tissue and has substantial adverse effects on patients. Therefore, the pathogenesis of IGF requires more extensive and in-depth research. In this case, a patient with confirmed IGF underwent initial nonsurgical periodontal therapy and gingivectomy, and the prognosis was good. The patient had no loss of periodontal attachment but had a history of swelling and bleeding of the gingiva prior to fibrous enlargement, which prompted further investigation. We explored the patient's subgingival microbiome and found a high abundance of periodontal pathogens. Gingival tissue biopsy revealed abundant fibrous tissue containing multiple inflammatory cell infiltrates. These results suggest that gingival inflammation secondary to periodontal pathogens can contribute to IGF onset.},
}

Humans
*Biofilms/growth & development
*Fibromatosis, Gingival/diagnosis/pathology/microbiology
*Gingiva/microbiology/pathology
Female
Adult
Male
Bacteria/isolation & purification
Gingivectomy/methods

@article {pmid38663668,
year = {2024},
author = {Zheng, C and Zhang, J and Ni, M and Pan, Y},
title = {Phosphate Recovery from Urban Sewage by the Biofilm Sequencing Batch Reactor Process: Key Factors in Biofilm Formation and Related Mechanisms.},
journal = {Environmental research},
volume = {},
number = {},
pages = {118985},
doi = {10.1016/j.envres.2024.118985},
pmid = {38663668},
issn = {1096-0953},
abstract = {The biofilm sequencing batch reactor (BSBR) technique has been deployed in the laboratory to enrich phosphorus from simulated wastewater, but it is still not clear what its performance will be when real world sewage is used. In this work, the effluent from the multi-stage anoxic-oxic (AO) activated sludge process at a sewage plant was used as the feed water for a BSBR pilot system, which had three reactors operating at different levels of dissolved oxygen (DO). The phosphorus adsorption and release, the biofilm growth, and the extracellular polymeric substances (EPS) components and contents were examined. The microbial communities and the signaling molecules N-acyl-l-homoserine lactones (AHLs) were also analyzed. Gratifyingly, the BSBR process successfully processed the treated sewage, and the biofilm developed phosphorus accumulation capability within 40 days. After entering stable operation, the system concentrated phosphate from 2.59 ± 0.77 mg/L in the influent to as much as 81.64 mg/L in the recovery liquid. Sludge discharge had profound impacts on all aspects of BSBR, and it was carried out successfully when the phosphorus absorption capacity of the biofilm alone was comparable to that of the reactor containing the activated sludge. Shortly after the sludge discharge, the phosphate concentration of the recovery liquid surged from 50 to 140 mg/L, the biofilm thickness grew from 20.56 to 67.32 μm, and the diversity of the microbial population plunged. Sludge discharge stimulated Candidatus competibacter to produce a large amount of AHLs, which was key in culturing the biofilm. Among the AHLs, both C10-HSL and 3OC12-HSL were significantly positively correlated with EPS and the abundance of Candidatus competibacter. The current results demonstrated BSBR as a viable option to enrich phosphorus from real world sewage with low phosphorus content and fluctuating chemistry. The mechanistic explorations also provided theoretical guidance for cultivating phosphorus-accumulating biofilms.},
}

@article {pmid38663625,
year = {2024},
author = {Xu, F and Jiang, M and Li, D and Yu, P and Ma, H and Lu, H},
title = {Protective effects of antibiotic resistant bacteria on susceptibles in biofilm: Influential factors, mechanism, and modeling.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {172668},
doi = {10.1016/j.scitotenv.2024.172668},
pmid = {38663625},
issn = {1879-1026},
abstract = {In environmental biofilms, antibiotic-resistant bacteria facilitate the persistence of susceptible counterparts under antibiotic stresses, contributing to increased community-level resistance. However, there is a lack of quantitative understanding of this protective effect and its influential factors, hindering accurate risk assessment of biofilm resistance in diverse environment. This study isolated an opportunistic Escherichia coli pathogen from soil, and engineered it with plasmids conferring antibiotic resistance. Protective effects of the ampicillin resistant strain (AmpR) on their susceptible counterparts (AmpS) were observed in ampicillin-stress colony biofilms. The concentration of ampicillin delineated protective effects into 3 zones: continuous protection (<1 MIC of AmpS), initial AmpS/R dependent (1-8 MIC of AmpS), and ineffective (>8 MIC of AmpS). Intriguingly, Zone 2 exhibited a surprising "less is more" phenomenon tuned by the initial AmpS/R ratio, where biofilm with an initially lower AmpR (1:50 vs 50:1) harbored 30-90 % more AmpR after 24 h growth under antibiotic stress. Compared to AmpS, AmpR displayed superiority in adhesion, antibiotic degradation, motility, and quorum sensing, allowing them to preferentially colonize biofilm edge and areas with higher ampicillin. An agent-based model incorporating protective effects successfully simulated tempo-spatial dynamics of AmpR and AmpS influenced by antibiotic stress and initial AmpS/R. This study provides a holistic view on the pervasive but poorly understood protective effects in biofilm, enabling development of better risk assessment and precisely targeted control strategies of biofilm resistance in diverse environment.},
}

@article {pmid38663447,
year = {2024},
author = {Zhang, Z and Ma, J and Xu, T and Wang, T and Jia, X and Lin, J and Lv, C and Cao, L and Ying, Y and Ji, L and Wang, S and Fu, C},
title = {Transpiration-Inspired Fabric Dressing for Acceleration Healing of Wound Infected with Biofilm.},
journal = {Advanced healthcare materials},
volume = {},
number = {},
pages = {e2401005},
doi = {10.1002/adhm.202401005},
pmid = {38663447},
issn = {2192-2659},
abstract = {In chronic wound management, efficacious handling of exudate and bacterial infections stands as a paramount challenge. Here we introduced a novel biomimetic fabric, inspired by the natural transpiration mechanisms in plants. Uniquely, the fabric combines a commercial polyethylene terephthalate (PET) fabric with asymmetrically grown 1D rutile titanium dioxide (TiO2) micro/nanostructures, emulating critical plant features: hierarchically porous networks and hydrophilic water conduction channels. This structure endows the fabric with exceptional antigravity wicking-evaporation performance, evidenced by a 780% one-way transport capability and a 0.75 g h[-1] water evaporation rate, which significantly surpasses that of conventional moisture-wicking textiles. Moreover, the incorporated 1D rutile TiO2 micro/nano-structures presented solar-light induced antibacterial activity, crucial for disrupting and eradicating wound biofilms. The biomimetic transpiration fabric has been employed to drain exudate and eradicate biofilms in Staphylococcus aureus (S. aureus)-infected wounds, demonstrating a much faster infection eradication capability compared to clinically common ciprofloxacin irrigation. These findings illuminate the path for developing high-performance, textile-based wound dressings, offering efficient clinical platforms to combat biofilms associated with chronic wounds. This article is protected by copyright. All rights reserved.},
}

@article {pmid38661711,
year = {2024},
author = {Souza, V and Polaquini, CR and de Moraes, GR and Oliveira Braga, AR and da Silva, PV and da Silva, DR and Ribeiro Lima, FR and Regasini, LO and Cássia Orlandi Sardi, J},
title = {Diacetylcurcumin: a novel strategy against Enterococcus faecalis biofilm in root canal disinfection.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {},
doi = {10.2217/fmb-2023-0235},
pmid = {38661711},
issn = {1746-0921},
abstract = {Aim: We evaluated Diacetylcurcumin (DAC), a derivative of curcumin, for its antibacterial and antibiofilm properties against Enterococcus faecalis. Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined, along with antibiofilm potential and toxicity in Galleria mellonella. Additionally, in silico computational analysis was performed to understand its mechanisms of action. Results & conclusion: DAC demonstrated significant antibacterial effects, with MIC and MBC values of 15.6 and 31.25 μg/ml, respectively, and reduced biofilm formation. A synergistic effect, reducing biofilm by 77%, was observed when combined with calcium hydroxide. G. mellonella toxicity tests confirmed DAC's safety at tested concentrations, suggesting its potential for use in root canal disinfection products.},
}

@article {pmid38660899,
year = {2024},
author = {Li, YY and Liu, HC and Wang, HP and DU, TY and Jiang, L},
title = {[Characteristics of drug resistance and biofilm formation in carbapenem-resistant Acinetobacter baumannii in hospitalized children].},
journal = {Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics},
volume = {26},
number = {4},
pages = {358-364},
pmid = {38660899},
issn = {1008-8830},
mesh = {*Acinetobacter baumannii/drug effects/genetics ; *Biofilms/drug effects ; *Carbapenems/pharmacology ; Humans ; Child ; *Acinetobacter Infections/microbiology ; Child, Preschool ; beta-Lactamases/genetics ; Child, Hospitalized ; Drug Resistance, Bacterial/genetics ; Anti-Bacterial Agents/pharmacology ; Female ; Infant ; Male ; Microbial Sensitivity Tests ; Bacterial Proteins/genetics ; },
abstract = {OBJECTIVES: To study the distribution, drug resistance, and biofilm characteristics of carbapenem-resistant Acinetobacter baumannii (CRAB) isolated from hospitalized children, providing a reference for the prevention and treatment of CRAB infections in hospitalized children.

METHODS: Forty-eight CRAB strains isolated from January 2019 to December 2022 were classified into epidemic and sporadic strains using repetitive extragenic palindromic sequence-based polymerase chain reaction. The drug resistance, biofilm phenotypes, and gene carriage of these two types of strains were compared.

RESULTS: Both the 22 epidemic strains and the 26 sporadic strains were producers of Class D carbapenemases or extended-spectrum β-lactamases with downregulated outer membrane porins, harboring the VIM, OXA-23, and OXA-51 genes. The biofilm formation capability of the sporadic strains was stronger than that of the epidemic strains (P<0.05). Genes related to biofilm formation, including Bap, bfs, OmpA, CsuE, and intI1, were detected in both epidemic and sporadic strains, with a higher detection rate of the intI1 gene in epidemic strains (P<0.05).

CONCLUSIONS: CRAB strains are colonized in the hospital, with sporadic strains having a stronger ability to form biofilms, suggesting the potential for forming new clonal transmissions in the hospital. Continuous monitoring of the epidemic trends of CRAB and early warning of the distribution of epidemic strains are necessary to reduce the risk of CRAB infections in hospitalized children.},
}

*Acinetobacter baumannii/drug effects/genetics
*Biofilms/drug effects
*Carbapenems/pharmacology
Humans
Child
*Acinetobacter Infections/microbiology
Child, Preschool
beta-Lactamases/genetics
Child, Hospitalized
Drug Resistance, Bacterial/genetics
Anti-Bacterial Agents/pharmacology
Female
Infant
Male
Microbial Sensitivity Tests
Bacterial Proteins/genetics

@article {pmid38659983,
year = {2024},
author = {Alharbi, NK and Azeez, ZF and Alhussain, HM and Shahlol, AMA and Albureikan, MOI and Elsehrawy, MG and Aloraini, GS and El-Nablaway, M and Khatrawi, EM and Ghareeb, A},
title = {Tapping the biosynthetic potential of marine Bacillus licheniformis LHG166, a prolific sulphated exopolysaccharide producer: structural insights, bio-prospecting its antioxidant, antifungal, antibacterial and anti-biofilm potency as a novel anti-infective lead.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1385493},
pmid = {38659983},
issn = {1664-302X},
abstract = {The escalating global threat of antimicrobial resistance necessitates prospecting uncharted microbial biodiversity for novel therapeutic leads. This study mines the promising chemical richness of Bacillus licheniformis LHG166, a prolific exopolysaccharide (EPSR2-7.22 g/L). It comprised 5 different monosaccharides with 48.11% uronic acid, 17.40% sulfate groups, and 6.09% N-acetyl glucosamine residues. EPSR2 displayed potent antioxidant activity in DPPH and ABTS[+], TAC and FRAP assays. Of all the fungi tested, the yeast Candida albicans displayed the highest susceptibility and antibiofilm inhibition. The fungi Aspergillus niger and Penicillium glabrum showed moderate EPSR2 susceptibility. In contrast, the fungi Mucor circinelloides and Trichoderma harzianum were resistant. Among G+ve tested bacteria, Enterococcus faecalis was the most susceptible, while Salmonella typhi was the most sensitive to G-ve pathogens. Encouragingly, EPSR2 predominantly demonstrated bactericidal effects against both bacterial classes based on MBC/MIC of either 1 or 2 superior Gentamicin. At 75% of MBC, EPSR2 displayed the highest anti-biofilm activity of 88.30% against B. subtilis, while for G-ve antibiofilm inhibition, At 75% of MBC, EPSR2 displayed the highest anti-biofilm activity of 96.63% against Escherichia coli, Even at the lowest dose of 25% MBC, EPSR2 reduced biofilm formation by 84.13% in E. coli, 61.46% in B. subtilis. The microbial metabolite EPSR2 from Bacillus licheniformis LHG166 shows promise as an eco-friendly natural antibiotic alternative for treating infections and oxidative stress.},
}