@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.},
}

@article {pmid38659587,
year = {2024},
author = {Chen, Q and Dong, Z and Yao, X and Sun, H and Pan, X and Liu, J and Huang, R},
title = {Bactericidal and biofilm eradication efficacy of a fluorinated benzimidazole derivative, TFBZ, against methicillin-resistant Staphylococcus aureus.},
journal = {Frontiers in pharmacology},
volume = {15},
number = {},
pages = {1342821},
pmid = {38659587},
issn = {1663-9812},
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) is a major inducement of nosocomial infections and its biofilm formation render the high tolerance to conventional antibiotics, which highlights the requirement to develop new antimicrobial agents urgently. In this study, we identified a fluorinated benzimidazole derivative, TFBZ, with potent antibacterial efficacy toward planktonic MRSA (MIC = 4 μg/mL, MBC = 8 μg/mL) and its persistent biofilms (≥99%, MBEC = 8 μg/mL). TFBZ manifested significant irreversible time-dependent killing against MRSA as characterized by diminished cell viability, bacterial morphological change and protein leakage. Furthermore, the results from CBD devices, crystal violet assay in conjunction with live/dead staining and scanning electron microscopy confirmed that TFBZ was capable of eradicating preformed MRSA biofilms with high efficiency. Simultaneously, TFBZ reduced the bacterial invasiveness and exerted negligible hemolysis and cytotoxicity toward mammalian cells, which ensuring the robust therapeutic effect on mouse skin abscess model. The transcriptome profiling and quantitative RT-PCR revealed that a set of encoding genes associated with cell adhesion, biofilm formation, translation process, cell wall biosynthesis was consistently downregulated in MRSA biofilms upon exposure to TFBZ. In conclusion, TFBZ holds promise as a valuable candidate for therapeutic applications against MRSA chronic infections.},
}

@article {pmid38658316,
year = {2024},
author = {Cassola, F and Ramírez, N and Delarmelina, C and Duarte, MCT},
title = {In vitro determination of the susceptibility of Malassezia furfur biofilm to different commercially used antimicrobials.},
journal = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica},
volume = {},
number = {},
pages = {},
doi = {10.1111/apm.13419},
pmid = {38658316},
issn = {1600-0463},
abstract = {Malassezia furfur is a yeast known as the etiological agent of seborrheic dermatitis. We evaluated the action of five different antimicrobials (amphotericin B, chloramphenicol, ketoconazole, fluconazole, and nystatin) on inhibiting biofilm formation and removing biofilm already formed by M. furfur. The assays were carried out using the microdilution method, and scanning electron microscopy images were used to analyze the biofilm structure. According to the results obtained, the percentage of inhibition was higher for chloramphenicol, followed by ketoconazole, nystatin, and amphotericin B. Regarding the eradication of the biofilm formed, the highest percentage was chloramphenicol, followed by ketoconazole and nystatin. Amphotericin B did not affect biofilm eradication, whereas fluconazole did not cause significant changes inhibiting or removing M. furfur biofilm. Therefore, except for fluconazole, all evaluated antimicrobials had inhibiting effects on the biofilm of M. furfur, either in its formation and/or eradication. Although the results achieved with chloramphenicol have been highlighted, further in vitro and in vivo studies are still needed in order to include this antimicrobial in the therapy of seborrheic dermatitis due to its toxicity, especially to the bone marrow.},
}

@article {pmid38658078,
year = {2024},
author = {Banerjee, A and Stockbridge, RB and Tenuta, LMA},
title = {Measurement and analysis of microbial fluoride resistance in dental biofilm models.},
journal = {Methods in enzymology},
volume = {696},
number = {},
pages = {155-174},
doi = {10.1016/bs.mie.2023.12.018},
pmid = {38658078},
issn = {1557-7988},
mesh = {*Biofilms/drug effects/growth & development ; *Streptococcus mutans/drug effects/genetics/physiology/metabolism/growth & development ; *Fluorides/pharmacology/metabolism ; *Candida albicans/drug effects/genetics/metabolism/physiology ; *Streptococcus gordonii/drug effects/genetics/physiology ; Humans ; Bacterial Proteins/genetics/metabolism ; Drug Resistance, Bacterial/genetics ; Dental Caries/microbiology ; },
abstract = {The interactions between communities of microorganisms inhabiting the dental biofilm is a major determinant of oral health. These biofilms are periodically exposed to high concentrations of fluoride, which is present in almost all oral healthcare products. The microbes resist fluoride through the action of membrane export proteins. This chapter describes the culture, growth and harvest conditions of model three-species dental biofilm comprised of cariogenic pathogens Streptococcus mutans and Candida albicans and the commensal bacterium Streptococcus gordonii. In order to examine the role of fluoride export by S. mutans in model biofilms, procedures for generating a strain of S. mutans with a genetic knockout of the fluoride exporter are described. We present a case study examining the effects of this mutant strain on the biofilm mass, acid production and mineral dissolution under exposure to low levels of fluoride. These general approaches can be applied to study the effects of any gene of interest in physiologically realistic multispecies oral biofilms.},
}

*Biofilms/drug effects/growth & development
*Streptococcus mutans/drug effects/genetics/physiology/metabolism/growth & development
*Fluorides/pharmacology/metabolism
*Candida albicans/drug effects/genetics/metabolism/physiology
*Streptococcus gordonii/drug effects/genetics/physiology
Humans
Bacterial Proteins/genetics/metabolism
Drug Resistance, Bacterial/genetics
Dental Caries/microbiology

@article {pmid38657691,
year = {2024},
author = {Cerda, Á and Gonzalez, M and Rodríguez, C and González, H and Serrano, J and Leiva, E},
title = {Feammox bacterial biofilm formation in HFMB.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {142072},
doi = {10.1016/j.chemosphere.2024.142072},
pmid = {38657691},
issn = {1879-1298},
abstract = {Nitrogen pollution has been increasing with the development of industrialization. Consequently, the excessive deposition of reactive nitrogen in the environment has generated the loss of biodiversity and eutrophication of different ecosystems. In 2005, a Feammox process was discovered that anaerobically metabolizes ammonium. Feammox with the use of hollow fiber membrane bioreactors (HFMB), based on the formation of biofilms of bacterial communities, has emerged as a possible efficient and sustainable method for ammonium removal in environments with high iron concentrations. This work sought to study the possibility of implementing, at laboratory scale, an efficient method by evaluating the use of HFMB. Samples from an internal circulation reactor (IC) incubated in culture media for Feammox bacteria. The cultures were enriched in a batch reactor to evaluate growth conditions. Next, HFMB assembly was performed, and Feammox parameters were monitored. Also, conventional PCR and scanning electron microscopy (SEM) analysis were performed to characterize the bacterial communities associated with biofilm formation. The use of sodium acetate presented the best performance for Feammox activity. The HFMB operation showed an ammonium (NH4[+]) removal of 50%. SEM analysis of the fibers illustrated the formation of biofilm networks formed by bacteria, which were identified as Albidiferax ferrireducens, Geobacter spp, Ferrovum myxofaciens, Shewanella spp., and Anammox. Functional genes Archaea/Bacteria ammonia monooxygenase, nrxA, hzsB, nirS and nosZ were also identified. The implementation of HFMB Feammox could be used as a sustainable tool for the removal of ammonium from wastewater produced because of anthropogenic activities.},
}

@article {pmid38656598,
year = {2024},
author = {Hassan, RM and Yehia, H and El-Behairy, MF and El-Azzouny, AA and Aboul-Enein, MN},
title = {Design and synthesis of new quinazolinone derivatives: investigation of antimicrobial and biofilm inhibition effects.},
journal = {Molecular diversity},
volume = {},
number = {},
pages = {},
pmid = {38656598},
issn = {1573-501X},
abstract = {New quinazolin-4-ones 9-32 were synthesized in an attempt to overcome the life-threatening antibiotic resistance phenomenon. The antimicrobial screening revealed that compounds 9, 15, 16, 18, 19, 20 and 29 are the most broad spectrum antimicrobial agents in this study with safe profile on human cell lines. Additionally, compounds 19 and 20 inhibited biofilm formation in Pseudomonas aeruginosa, which is regulated by quorum sensing system, at sub-minimum inhibitory concentrations (sub-MICs) with IC50 values 3.55 and 6.86 µM, respectively. By assessing other pseudomonal virulence factors suppression, it was found that compound 20 decreased cell surface hydrophobicity compromising bacterial cells adhesion, while both compounds 19 and 20 curtailed the exopolysaccharide production which constitutes the major component of the matrix binding biofilm components together. Also, at sub-MICs Pseudomonas cells twitching motility was impeded by compounds 19 and 20, a trait which augments the cells pathogenicity and invasion potential. Molecular docking study was performed to further evaluate the binding mode of candidates 19 and 20 as inhibitors of P. aeruginosa quorum sensing transcriptional regulator PqsR. The achieved results demonstrate that both compounds bear promising potential for discovering new anti-biofilm and quorum quenching agents against Pseudomonas aeruginosa without triggering resistance mechanisms as the normal bacterial life cycle is not disturbed.},
}

@article {pmid38656049,
year = {2024},
author = {Poker, BC and Oliveira, VC and Macedo, AP and Gonçalves, M and Ramos, AP and Silva-Lovato, CH},
title = {Evaluation of surface roughness, wettability and adhesion of multispecies biofilm on 3D-printed resins for the base and teeth of complete dentures.},
journal = {Journal of applied oral science : revista FOB},
volume = {32},
number = {},
pages = {e20230326},
doi = {10.1590/1678-7757-2023-0326},
pmid = {38656049},
issn = {1678-7765},
mesh = {*Biofilms ; *Surface Properties ; *Printing, Three-Dimensional ; *Streptococcus mutans/physiology ; *Staphylococcus aureus/physiology ; *Candida albicans/physiology ; *Wettability ; *Microscopy, Electron, Scanning ; *Materials Testing ; *Denture Bases/microbiology ; *Microscopy, Confocal ; *Acrylic Resins/chemistry ; *Bacterial Adhesion ; Analysis of Variance ; Reproducibility of Results ; Denture, Complete/microbiology ; Reference Values ; Colony Count, Microbial ; Linear Models ; },
abstract = {OBJECTIVE: This study evaluated the surface roughness, wettability and adhesion of multispecies biofilms (Candida albicans, Staphylococcus aureus and Streptococcus mutans) on 3D-printed resins for complete denture bases and teeth compared to conventional resins (heat-polymerized acrylic resin; artificial pre-fabricated teeth).

METHODOLOGY: Circular specimens (n=39; 6.0 mm Ø × 2.0 mm) of each group were subjected to roughness (n=30), wettability (n=30) and biofilm adhesion (n=9) tests. Three roughness measurements were taken by laser confocal microscopy and a mean value was calculated. Wettability was evaluated by the contact angle of sessile drop method, considering the mean of the three evaluations per specimen. In parallel, microorganism adhesion to resin surfaces was evaluated using a multispecies biofilm model. Microbial load was evaluated by determining the number of Colony Forming Units (CFU/mL) and by scanning electron microscopy (SEM). Data were subjected to the Wald test in a generalized linear model with multiple comparisons and Bonferroni adjustment, as well as two-way ANOVA (α=5%).

RESULTS: The roughness of the conventional base resin (0.01±0.04) was lower than that of the conventional tooth (0.14±0.04) (p=0.023) and 3D-printed base (0.18±0.08) (p<0.001). For wettability, conventional resin (84.20±5.57) showed a higher contact angle than the 3D-printed resin (60.58±6.18) (p<0.001). Higher microbial loads of S. mutans (p=0.023) and S. aureus (p=0.010) were observed on the surface of the conventional resin (S. mutans: 5.48±1.55; S. aureus: 7.01±0.57) compared to the 3D-printed resin (S. mutans: 4.11±1.96; S. aureus: 6.42±0.78). The adhesion of C. albicans was not affected by surface characteristics. The conventional base resin showed less roughness than the conventional dental resin and the printed base resin.

CONCLUSION: The 3D-printed resins for base and tooth showed less hydrophobicity and less adhesion of S. mutans and S. aureus than conventional resins.},
}

*Biofilms
*Surface Properties
*Printing, Three-Dimensional
*Streptococcus mutans/physiology
*Staphylococcus aureus/physiology
*Candida albicans/physiology
*Wettability
*Microscopy, Electron, Scanning
*Materials Testing
*Denture Bases/microbiology
*Microscopy, Confocal
*Acrylic Resins/chemistry
*Bacterial Adhesion
Analysis of Variance
Reproducibility of Results
Denture, Complete/microbiology
Reference Values
Colony Count, Microbial
Linear Models

@article {pmid38655044,
year = {2024},
author = {Ahrari, F and Nazifi, M and Mazhari, F and Ghazvini, K and Menbari, S and Fekrazad, R and Babaei, K and Banihashemrad, A},
title = {Photoinactivation Effects of Curcumin, Nano-curcumin, and Erythrosine on Planktonic and Biofilm Cultures of Streptococcus mutans.},
journal = {Journal of lasers in medical sciences},
volume = {15},
number = {},
pages = {e7},
pmid = {38655044},
issn = {2008-9783},
abstract = {Introduction: This in vitro study was conducted to assess the phototoxic effects of curcumin, nano-curcumin, and erythrosine on the viability of Streptococcus mutans (S. mutans) in suspension and biofilm forms. Methods: Various concentrations of curcumin (1.5 g/L, 3 g/L), nano-curcumin (3 g/L), and erythrosine (100 μM/L, 250 μM/L) were examined for their impact on planktonic and biofilm cultures of S. mutans, either individually or in conjunction with light irradiation (photodynamic therapy or PDT). A blue light-emitting diode (LED) with a central wavelength of 450 nm served as the light source. The results were compared to 0.12% chlorhexidine digluconate (CHX) as the positive control, and a solution containing neither a photosensitizer (PS) nor a light source as the negative control group. The dependent variable was the number of viable microorganisms per experiment (CFU/mL). Results: Antimicrobial PDT caused a significant reduction in the viability of S. mutans in both planktonic and biofilm forms, compared to the negative control group (P<0.05). The highest cell killing was observed in PDT groups with curcumin 3 g/L or erythrosine 250 μmol/L, although the difference with PDT groups using curcumin 1.5 g/L or erythrosine 100 μmol/L was not significant (P>0.05). Antimicrobial treatments were more effective against planktonic S. mutans than the biofilm form. Conclusion: PDT with either curcumin 1.5 g/L or erythrosine 100 μmol/L may be suggested as an alternative to CHX to inactivate the bacteria in dental plaque or deep cavities. Nano-curcumin, at the selected concentration, exhibited lower efficacy in killing S. mutans compared to Curcumin or erythrosine.},
}

@article {pmid38654614,
year = {2024},
author = {Li, Z and Lu, S and Liu, W and Chen, Z and Huang, Y and Li, X and Gong, J and Chen, X},
title = {Customized Lanthanide Nanobiohybrids for Noninvasive Precise Phototheranostics of Pulmonary Biofilm Infection.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.4c00777},
pmid = {38654614},
issn = {1936-086X},
abstract = {A noninvasive strategy for in situ diagnosis and precise treatment of bacterial biofilm infections is highly anticipated but still a great challenge. Currently, no in vivo biofilm-targeted theranostic agent is available. Herein, we fabricated intelligent theranostic alginate lyase (Aly)-NaNdF4 nanohybrids with a 220 nm sunflower-like structure (NaNdF4@DMS-Aly) through an enrichment-encapsulating strategy, which exhibited excellent photothermal conversion efficiency and the second near-infrared (NIR-II) luminescence. Benefiting from the site-specific targeting and biofilm-responsive Aly release from NaNdF4@DMS-Aly, we not only enabled noninvasive diagnosis but also realized Aly-photothermal synergistic therapy and real-time evaluation of therapeutic effect in mice models with Pseudomonas aeruginosa biofilm-induced pulmonary infection. Furthermore, such nanobiohybrids with a sheddable siliceous shell are capable of delaying the NaNdF4 dissolution and biodegradation upon accomplishing the therapy, which is highly beneficial for the biosafety of theranostic agents.},
}

@article {pmid38652947,
year = {2024},
author = {Pokhrel, D and Thames, HT and Fugate, H and Dinh, T and Schilling, W and White, S and Ramachandran, R and Sukumaran, AT and Zhang, L},
title = {Increase in temperature facilitates Campylobacter jejuni biofilm formation under both aerobic and microaerobic incubation.},
journal = {Poultry science},
volume = {103},
number = {6},
pages = {103753},
doi = {10.1016/j.psj.2024.103753},
pmid = {38652947},
issn = {1525-3171},
abstract = {The formation of Campylobacter jeuni biofilms on processing surfaces is a significant concern in poultry processing, contributing to food safety risks. This study focused on assessing the biofilm forming capabilities of 12 field isolates of C. jejuni of different aerotolerance categories on stainless steel surfaces, a prevalent material in poultry processing environments. Working cultures of each isolate were prepared to approximately 6 log CFU/mL and incubated on stainless steel coupons under microaerobic or aerobic conditions at room temperature or 42°C for 72 h. Biofilm attached cells were enumerated using direct plating and biofilm density was measured using a crystal violet assay by measuring the optical density (OD600) a. Data analysis was conducted using the PROC GLIMMIX procedure in SAS 9.4 with a significance level of 0.05. The study revealed a notable interaction between aerotolerance categories and temperature (P < 0.039) impacting the number of biofilms attached C. jejuni cells on stainless steel coupons. All isolates had significantly higher counts when incubated at 42°C compared to room temperature, regardless of oxygen level (P < 0.001). Furthermore, stronger biofilm density was observed at 42°C compared to room temperature, regardless of oxygen level. These findings underscore the influence of temperature on the biofilm forming ability of C. jejuni. The ability of these field isolates to form biofilms under various environmental conditions suggests a heightened potential for surface colonization and increased infection risk in poultry processing facilities.},
}

@article {pmid38652228,
year = {2024},
author = {Cao, CY and Hou, ZJ and Ding, MZ and Gao, GR and Qiao, B and Wei, SY and Cheng, JS},
title = {Integrated Biofilm Modification and Transcriptional Analysis for Improving Fengycin Production in Bacillus amyloliquefaciens.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {38652228},
issn = {1867-1314},
support = {2018YFA0902200//National Key R&D Program of China/ ; 2018YFA0902200//National Key R&D Program of China/ ; 2018YFA0902200//National Key R&D Program of China/ ; 21878224//National Natural Science Foundation of China/ ; },
abstract = {Although fengycin exhibits broad-spectrum antifungal properties, its application is hindered due to its low biosynthesis level and the co-existence of iturin A and surfactin in Bacillus amyloliquefaciens HM618, a probiotic strain. In this study, transcriptome analysis and gene editing were used to explore the potential mechanisms regulating fengycin production in B. amyloliquefaciens. The fengycin level of B. amyloliquefacien HM-3 (∆itu-ΔsrfAA) was 88.41 mg/L after simultaneously inhibiting the biosyntheses of iturin A and surfactin. The knockout of gene eps associated with biofilm formation significantly increased the fengycin level of the strain HM618, whereas the fengycin level decreased 32.05% after knocking out sinI, a regulator of biofilm formation. Transcriptome analysis revealed that the differentially expressed genes, involved in pathways of amino acid and fatty acid syntheses, were significantly down-regulated in the recombinant strains, which is likely associated with a decrease of fengycin production. The knockout of gene comQXPA and subsequent transcriptome analysis revealed that the ComQXPA quorum sensing system played a positive regulatory role in fengycin production. Through targeted genetic modifications and fermentation optimization, the fengycin production of the engineered strain HM-12 (∆itu-ΔsrfAA-ΔyvbJ) in a 5-L fermenter reached 1.172 g/L, a 12.26-fold increase compared to the fengycin level in the strain HM-3 (∆itu-ΔsrfAA) in the Erlenmeyer flask. Taken together, these results reveal the underlying metabolic mechanisms associated with fengycin synthesis and provide a potential strategy for improving fengycin production in B. amyloliquefaciens.},
}

@article {pmid38652445,
year = {2022},
author = {Heredia, MY and Andes, D},
title = {Correction to: Production and Isolation of the Candida Species Biofilm Extracellular Matrix.},
journal = {Methods in molecular biology (Clifton, N.J.)},
volume = {2542},
number = {},
pages = {C1},
doi = {10.1007/978-1-0716-2549-1_26},
pmid = {38652445},
issn = {1940-6029},
}

@article {pmid38651875,
year = {2024},
author = {Park, K-H and Kim, D and Jung, M and Kim, DY and Lee, Y-M and Lee, MS and Hong, K-W and Bae, I-G and Hong, SI and Cho, O-H},
title = {Effects of sub-inhibitory concentrations of nafcillin, vancomycibipn, ciprofloxacin, and rifampin on biofilm formation of clinical methicillin-resistant Staphylococcus aureus.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0341223},
doi = {10.1128/spectrum.03412-23},
pmid = {38651875},
issn = {2165-0497},
abstract = {UNLABELLED: Methicillin-resistant Staphylococcus aureus (MRSA) infections are often difficult to treat because of their biofilm-forming ability and antimicrobial resistance. We investigated the effects of sub-minimal inhibitory concentrations (MICs) of antibiotics on MRSA biofilm formation. Clinical MRSA isolates were grown with sub-MICs (1/256-1/2 × MICs) of nafcillin, vancomycin, ciprofloxacin, and rifampin. The biofilm biomass was measured using crystal violet staining. Of the 107 MRSA isolates tested, 63 (58.9%) belonged to sequence type 5 (ST5), and 44 (41.1%) belonged to ST72. The MIC50/MIC90 values of nafcillin, vancomycin, ciprofloxacin, and rifampin were 256/512, 1/2, 64/512, and 0.008/0.03 mg/L, respectively. The sub-MICs of nafcillin, vancomycin, ciprofloxacin, and rifampin promoted biofilm formation in 75 (70.1%), 49 (45.8%), 89 (83.2%), and 89 (83.2%) isolates, respectively. At sub-MICs of nafcillin, the factors associated with strong biofilm induction were the ST5 strain (P = 0.001) and agr dysfunction (P = 0.005). For the sub-MICs of ciprofloxacin, the associated factors were the ST5 strain (P = 0.002), staphylococcal protein A type t002 strain (P < 0.001), and ciprofloxacin resistance (P < 0.001). Among the sub-MICs of rifampin, only ST5 was associated with strong biofilm induction (P = 0.006). Because the sub-MICs of rifampin were much lower than clinically relevant concentrations, we further tested the capability of biofilm induction in 0.03[Formula: see text]32 mg/L of rifampin. At these concentrations, rifampin-induced biofilm formation was rare in rifampin-susceptible MRSA [1.0% (1 of 100)] but common in rifampin-resistant MRSA [71.4% (5 of 7), P < 0.001]. Induction of biofilm biomass at sub-MICs of antibiotics is common in clinical MRSA isolates and is differentially affected by the MRSA strain and antibiotic class.

IMPORTANCE: Bacteria can be exposed to sub-MICs of antibiotics at the beginning and end of a dosing regimen, between doses, or during low-dose therapies. Growing evidence suggests that sub-MICs of antimicrobials can stimulate MRSA biofilm formation and alter the composition of the biofilm matrix. Pevious studies have found that sub-MICs of oxacillin, methicillin, and amoxicillin promote biofilm formation in some community-acquired MRSA (CA-MRSA). We evaluated biofilm induction by sub-MICs of four different classes of antibiotics in 44 CA-MRSA and 63 healthcare-associated MRSA (HA-MRSA) strains. Our study indicated that sub-MICs of nafcillin, vancomycin, ciprofloxacin, and rifampin frequently promote biofilm induction in clinical MRSA isolates. Strong biofilm induction in sub-MICs of nafcillin, ciprofloxacin, and rifampin was more frequent in HA-MRSA than in CA-MRSA. Antibiotic-induced biofilm formation depends on the antibiotic class, MRSA strain, and antibiotic resistance. Our results emphasize the importance of maintaining effective bactericidal concentrations of antibiotics to treat biofilm-related infections.},
}

@article {pmid38651823,
year = {2024},
author = {Galvez-Llompart, M and Hierrezuelo, J and Blasco, M and Zanni, R and Galvez, J and de Vicente, A and Pérez-García, A and Romero, D},
title = {Targeting bacterial growth in biofilm conditions: rational design of novel inhibitors to mitigate clinical and food contamination using QSAR.},
journal = {Journal of enzyme inhibition and medicinal chemistry},
volume = {39},
number = {1},
pages = {2330907},
doi = {10.1080/14756366.2024.2330907},
pmid = {38651823},
issn = {1475-6374},
abstract = {Antimicrobial resistance (AMR) is a pressing global issue exacerbated by the abuse of antibiotics and the formation of bacterial biofilms, which cause up to 80% of human bacterial infections. This study presents a computational strategy to address AMR by developing three novel quantitative structure-activity relationship (QSAR) models based on molecular topology to identify potential anti-biofilm and antibacterial agents. The models aim to determine the chemo-topological pattern of Gram (+) antibacterial, Gram (-) antibacterial, and biofilm formation inhibition activity. The models were applied to the virtual screening of a commercial chemical database, resulting in the selection of 58 compounds. Subsequent in vitro assays showed that three of these compounds exhibited the most promising antibacterial activity, with potential applications in enhancing food and medical device safety.},
}

@article {pmid38650753,
year = {2024},
author = {Wen, Z and Chen, Y and Liu, T and Han, J and Jiang, Y and Zhang, K},
title = {Predicting Antibiotic Tolerance in hvKP and cKP Respiratory Infections Through Biofilm Formation Analysis and Its Resistance Implications.},
journal = {Infection and drug resistance},
volume = {17},
number = {},
pages = {1529-1537},
pmid = {38650753},
issn = {1178-6973},
abstract = {INTRODUCTION: Respiratory infections are a major global health concern, with Klebsiella pneumoniae standing out due to its evolving antibiotic resistance. This study compares the resistance profiles of hypervirulent Klebsiella pneumoniae (hvKP) and classical Klebsiella pneumoniae (cKP), aiming to shed light on their clinical implications.

METHODS: We analyzed 86 cases, comprising 42 hvKP and 44 cKP strains, using comprehensive antimicrobial susceptibility testing and clinical data evaluation to assess antibiotic tolerance and resistance mechanisms.

RESULTS: Our findings reveal distinct resistance patterns between hvKP and cKP, highlighting the role of chromosomal mutations and plasmid-mediated gene transfer in conferring antibiotic resistance. Notably, hvKP strains exhibited unique resistance trends, including the production of extended-spectrum β-lactamases (ESBLs) and carbapenemases, differing from those of cKP.

DISCUSSION: This research underscores the importance of continuous surveillance and the development of targeted therapies against antibiotic-resistant Klebsiella pneumoniae. It emphasizes the critical need for judicious antibiotic use and novel therapeutic approaches to combat respiratory infections caused by these increasingly resistant pathogens.},
}

@article {pmid38650397,
year = {2024},
author = {Kovács, F and Balla, N and Bozó, A and Harmath, A and Jakab, Á and Tóth, Z and Nagy, F and Majoros, L and Kovács, R},
title = {Epidemiology, clinical characteristics, outcome and biofilm forming properties in candidaemia: A single-centre retrospective 4-year analysis from Hungary.},
journal = {Mycoses},
volume = {67},
number = {4},
pages = {e13727},
doi = {10.1111/myc.13727},
pmid = {38650397},
issn = {1439-0507},
support = {UNKP-23-5-DE-480//New National Excellence Program of the Ministry for Innovation and Technology from the Source of the National Research, Development and Innovation Fund/ ; NKFIH FK138462//Hungarian National Research, Development and Innovation Office/ ; BO/00127/21/8//Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences/ ; },
abstract = {BACKGROUND: Candidaemia is a life-threatening disease that is associated with high mortality, especially in intensive care units (ICUs). The number of comprehensive studies dealing with the epidemiologic characteristics of biofilm-related properties is limited.

OBJECTIVE: This study evaluated the clinical characteristics of candidaemia, to assess the biofilm-forming properties of isolates, and to identify the risk factors of mortality.

PATIENTS AND METHODS: A total of 149 candidaemia episodes from the University of Debrecen, Clinical Centre, between January 2020 and December 2023 were investigated retrospectively. The susceptibility of Candida isolates to fluconazole, amphotericin B, anidulafungin, caspofungin, and micafungin was evaluated and compared to the susceptibility of 1-day-old biofilms. Multivariate logistic regression analysis was applied to identify the independent predictors of 30-day mortality rate.

RESULTS: The most common Candida species was Candida albicans (41%), followed by C. parapsilosis (20%), C. glabrata (14%), C. tropicalis (13%), rare Candida species (7%), and C. krusei (5%). Sixty-six percent of Candida isolates were biofilm formers and 44% had high metabolic activity. The 30-day mortality rate was 52%, which was higher in ICUs (65%). The logistic regression analysis revealed several factors significantly influencing mortality including ICU admission (odds ratio [OR] 2.99, 95% confidence interval [CI] 1.17-8.04, p = 0.025), fluconazole treatment (OR 4.12, 95% CI 1.62-11.42, p = .004), and pneumonia (OR 0.261, 95% CI 0.1-0.67, p = .006).

CONCLUSIONS: This comprehensive analysis supports the better characterisation of candidaemia in healthcare settings, which ultimately may reduce mortality among patients.},
}

@article {pmid38649897,
year = {2024},
author = {Chan, YL and Chee, CF and Tang, SN and Tay, ST},
title = {Unveilling genetic profiles and correlations of biofilm-associated genes, quorum sensing, and antibiotic resistance in Staphylococcus aureus isolated from a Malaysian Teaching Hospital.},
journal = {European journal of medical research},
volume = {29},
number = {1},
pages = {246},
pmid = {38649897},
issn = {2047-783X},
support = {IIRG003C-19FNW//Impact Oriented Interdisciplinary Grant/ ; },
abstract = {BACKGROUND: Staphylococcus aureus is a notorious multidrug resistant pathogen prevalent in healthcare facilities worldwide. Unveiling the mechanisms underlying biofilm formation, quorum sensing and antibiotic resistance can help in developing more effective therapy for S. aureus infection. There is a scarcity of literature addressing the genetic profiles and correlations of biofilm-associated genes, quorum sensing, and antibiotic resistance among S. aureus isolates from Malaysia.

METHODS: Biofilm and slime production of 68 methicillin-susceptible S. aureus (MSSA) and 54 methicillin-resistant (MRSA) isolates were determined using a a plate-based crystal violet assay and Congo Red agar method, respectively. The minimum inhibitory concentration values against 14 antibiotics were determined using VITEK® AST-GP67 cards and interpreted according to CLSI-M100 guidelines. Genetic profiling of 11 S. aureus biofilm-associated genes and agr/sar quorum sensing genes was performed using single or multiplex polymerase chain reaction (PCR) assays.

RESULTS: In this study, 75.9% (n = 41) of MRSA and 83.8% (n = 57) of MSSA isolates showed strong biofilm-forming capabilities. Intermediate slime production was detected in approximately 70% of the isolates. Compared to MSSA, significantly higher resistance of clindamycin, erythromycin, and fluoroquinolones was noted among the MRSA isolates. The presence of intracellular adhesion A (icaA) gene was detected in all S. aureus isolates. All MSSA isolates harbored the laminin-binding protein (eno) gene, while all MRSA isolates harbored intracellular adhesion D (icaD), clumping factors A and B (clfA and clfB) genes. The presence of agrI and elastin-binding protein (ebpS) genes was significantly associated with biofilm production in MSSA and MRSA isolates, respectively. In addition, agrI gene was also significantly correlated with oxacillin, cefoxitin, and fluoroquinolone resistance.

CONCLUSIONS: The high prevalence of biofilm and slime production among MSSA and MRSA isolates correlates well with the detection of a high prevalence of biofilm-associated genes and agr quorum sensing system. A significant association of agrI gene was found with cefoxitin, oxacillin, and fluoroquinolone resistance. A more focused approach targeting biofilm-associated and quorum sensing genes is important in developing new surveillance and treatment strategies against S. aureus biofilm infection.},
}

@article {pmid38649100,
year = {2024},
author = {Gulati, M and Thomas, JM and Ennis, CL and Hernday, AD and Rawat, M and Nobile, CJ},
title = {The bacillithiol pathway is required for biofilm formation in Staphylococcus aureus.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {106657},
doi = {10.1016/j.micpath.2024.106657},
pmid = {38649100},
issn = {1096-1208},
abstract = {Staphylococcus aureus is a major human pathogen that can cause infections that range from superficial skin and mucosal infections to life threatening disseminated infections. S. aureus can attach to medical devices and host tissues and form biofilms that allow the bacteria to evade the host immune system and provide protection from antimicrobial agents. To counter host-generated oxidative and nitrosative stress mechanisms that are part of the normal host responses to invading pathogens, S. aureus utilizes low molecular weight (LMW) thiols, such as bacillithiol (BSH). Additionally, S. aureus synthesizes its own nitric oxide (NO), which combined with its downstream metabolites may also protect the bacteria against specific host responses. We have previously shown that LMW thiols are required for biofilm formation in Mycobacterium smegmatis and Pseudomonas aeruginosa. Here, we show that the S. aureus bshC mutant strain, which is defective in the last step of the BSH pathway and lacks BSH, is impaired in biofilm formation. We also identify a possible S-nitrosobacillithiol reductase (BSNOR), similar in sequence to an S-nitrosomycothiol reductase found in M. smegmatis and show that the putative S. aureus bsnoR mutant strain has reduced levels of BSH and decreased biofilm formation. Our studies also show that NO plays an important role in biofilm formation and that acidified sodium nitrite severely reduces biofilm thickness. These studies provide insight into the roles of oxidative and nitrosative stress mechanisms on biofilm formation and indicate that BSH and NO are key players in normal biofilm formation in S. aureus.},
}

@article {pmid38647810,
year = {2024},
author = {Zhang, CL and Wang, C and Dong, YS and Sun, YQ and Xiu, ZL},
title = {Dynamic immobilization of bacterial cells on biofilm in a polyester nonwoven chemostat.},
journal = {Bioresources and bioprocessing},
volume = {11},
number = {1},
pages = {17},
pmid = {38647810},
issn = {2197-4365},
support = {No. 2022YFA0911802//National Key R&D Program of China/ ; 2022YFA0911804//National Key R&D Program of China/ ; },
abstract = {Cell immobilization plays an important role in biocatalysis for high-value products. It is necessary to maintain the viability of immobilized cells for bioconversion using viable cells as biocatalysts. In this study, a novel polyester nonwoven chemostat was designed for cell immobilization to investigate biofilm formation and the dynamic balance between adsorption and desorption of cells on polyester nonwoven. The polyester nonwoven was suitable for cell immobilization, and the cell numbers on the polyester nonwoven can reach 6.5 ± 0.38 log CFU/mL. After adding the polyester nonwoven to the chemostat, the fluctuation phenomenon of free bacterial cells occurred. The reason for this phenomenon was the balance between adsorption and desorption of bacterial cells on the polyester nonwoven. Bacterial cells could adhere to the surface of polyester nonwoven via secreting extracellular polymeric substances (EPS) to form biofilms. As the maturation of biofilms, some dead cells inside the biofilms can cause the detachment of biofilms. This process of continuous adsorption and desorption of cells can ensure that the polyester nonwoven chemostat has lasting biological activity.},
}

@article {pmid38647288,
year = {2024},
author = {Waegenaar, F and García-Timermans, C and Van Landuyt, J and De Gusseme, B and Boon, N},
title = {Impact of operational conditions on drinking water biofilm dynamics and coliform invasion potential.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0004224},
doi = {10.1128/aem.00042-24},
pmid = {38647288},
issn = {1098-5336},
abstract = {UNLABELLED: Biofilms within drinking water distribution systems serve as a habitat for drinking water microorganisms. However, biofilms can negatively impact drinking water quality by causing water discoloration and deterioration and can be a reservoir for unwanted microorganisms. In this study, we investigated whether indicator organisms for drinking water quality, such as coliforms, can settle in mature drinking water biofilms. Therefore, a biofilm monitor consisting of glass rings was used to grow and sample drinking water biofilms. Two mature drinking water biofilms were characterized by flow cytometry, ATP measurements, confocal laser scanning microscopy, and 16S rRNA sequencing. Biofilms developed under treated chlorinated surface water supply exhibited lower cell densities in comparison with biofilms resulting from treated groundwater. Overall, the phenotypic as well as the genotypic characteristics were significantly different between both biofilms. In addition, the response of the biofilm microbiome and possible biofilm detachment after minor water quality changes were investigated. Limited changes in pH and free chlorine addition, to simulate operational changes that are relevant for practice, were evaluated. It was shown that both biofilms remained resilient. Finally, mature biofilms were prone to invasion of the coliform, Serratia fonticola. After spiking low concentrations (i.e., ±100 cells/100 mL) of the coliform to the corresponding bulk water samples, the coliforms were able to attach and get established within the mature biofilms. These outcomes emphasize the need for continued research on biofilm detachment and its implications for water contamination in distribution networks.

IMPORTANCE: The revelation that even low concentrations of coliforms can infiltrate into mature drinking water biofilms highlights a potential public health concern. Nowadays, the measurement of coliform bacteria is used as an indicator for fecal contamination and to control the effectiveness of disinfection processes and the cleanliness and integrity of distribution systems. In Flanders (Belgium), 533 out of 18,840 measurements exceeded the established norm for the coliform indicator parameter in 2021; however, the source of microbial contamination is mostly unknown. Here, we showed that mature biofilms, are susceptible to invasion of Serratia fonticola. These findings emphasize the importance of understanding and managing biofilms in drinking water distribution systems, not only for their potential to influence water quality, but also for their role in harboring and potentially disseminating pathogens. Further research into biofilm detachment, long-term responses to operational changes, and pathogen persistence within biofilms is crucial to inform strategies for safeguarding drinking water quality.},
}

@article {pmid38647577,
year = {2022},
author = {Wang, D and Unsal, T and Kumseranee, S and Punpruk, S and Saleh, MA and Alotaibi, MD and Xu, D and Gu, T},
title = {Mitigation of carbon steel biocorrosion using a green biocide enhanced by a nature-mimicking anti-biofilm peptide in a flow loop.},
journal = {Bioresources and bioprocessing},
volume = {9},
number = {1},
pages = {67},
pmid = {38647577},
issn = {2197-4365},
abstract = {Biocorrosion, also called microbiologically influenced corrosion (MIC), is a common operational threat to many industrial processes. It threatens carbon steel, stainless steel and many other metals. In the bioprocessing industry, reactor vessels in biomass processing and bioleaching are prone to MIC. MIC is caused by biofilms. The formation and morphology of biofilms can be impacted by fluid flow. Fluid velocity affects biocide distribution and MIC. Thus, assessing the efficacy of a biocide for the mitigation of MIC under flow condition is desired before a field trial. In this work, a benchtop closed flow loop bioreactor design was used to investigate the biocide mitigation of MIC of C1018 carbon steel at 25 °C for 7 days using enriched artificial seawater. An oilfield biofilm consortium was analyzed using metagenomics. The biofilm consortium was grown anaerobically in the flow loop which had a holding vessel for the culture medium and a chamber to hold C1018 carbon steel coupons. Peptide A (codename) was a chemically synthesized cyclic 14-mer (cys-ser-val-pro-tyr-asp-tyr-asn-trp-tyr-ser-asn-trp-cys) with its core 12-mer sequence originated from a biofilm dispersing protein secreted by a sea anemone which possesses a biofilm-free exterior. It was used as a biocide enhancer. The combination of 50 ppm (w/w) THPS (tetrakis hydroxymethyl phosphonium sulfate) biocide + 100 nM (180 ppb by mass) Peptide A resulted in extra 1-log reduction in the sulfate reducing bacteria (SRB) sessile cell count and the acid producing bacteria (APB) sessile cell count compared to 50 ppm THPS alone treatment. Furthermore, with the enhancement of 100 nM Peptide A, extra 44% reduction in weight loss and 36% abatement in corrosion pit depth were achieved compared to 50 ppm THPS alone treatment.},
}

@article {pmid38650289,
year = {2021},
author = {Ding, Q and Liu, Y and Hu, G and Guo, L and Gao, C and Chen, X and Chen, W and Chen, J and Liu, L},
title = {Engineering Escherichia coli biofilm to increase contact surface for shikimate and L-malate production.},
journal = {Bioresources and bioprocessing},
volume = {8},
number = {1},
pages = {118},
pmid = {38650289},
issn = {2197-4365},
support = {2020YFA0908300//National Key R & D Program of China/ ; 32021005//Science Fund for Creative Research Groups of the National Natural Science Foundation of China/ ; BK20211529//Provincal Outstanding Youth Foundation of Jiangsu Province/ ; 21978113//the National Natural Science Foundation of China/ ; 22008087//the National Natural Science Foundation of China/ ; 22108099//National Natural Science Foundation of China/ ; },
abstract = {Microbial organelles are a promising model to promote cellular functions for the production of high-value chemicals. However, the concentrations of enzymes and nanoparticles are limited by the contact surface in single Escherichia coli cells. Herein, the definition of contact surface is to improve the amylase and CdS nanoparticles concentration for enhancing the substrate starch and cofactor NADH utilization. In this study, two biofilm-based strategies were developed to improve the contact surface for the production of shikimate and L-malate. First, the contact surface of E. coli was improved by amylase self-assembly with a blue light-inducible biofilm-based SpyTag/SpyCatcher system. This system increased the glucose concentration by 20.7% and the starch-based shikimate titer to 50.96 g L[-1], which showed the highest titer with starch as substrate. Then, the contact surface of E. coli was improved using a biofilm-based CdS-biohybrid system by light-driven system, which improved the NADH concentration by 83.3% and increased the NADH-dependent L-malate titer to 45.93 g L[-1]. Thus, the biofilm-based strategies can regulate cellular functions to increase the efficiency of microbial cell factories based on the optogenetics, light-driven, and metabolic engineering.},
}

@article {pmid38650271,
year = {2021},
author = {Atnafu, T and Leta, S},
title = {A novel fragmented anode biofilm microbial fuel cell (FAB-MFC) integrated system for domestic wastewater treatment and bioelectricity generation.},
journal = {Bioresources and bioprocessing},
volume = {8},
number = {1},
pages = {112},
pmid = {38650271},
issn = {2197-4365},
abstract = {BACKGROUND: The critical MFC design challenge is to increase anode surface area. A novel FAB-MFC integrated system was developed and evaluated for domestic wastewater treatment. It was operated in fed-batch flow mode at 1-3 days of HRT with 755 mg/L CODIN and 0.76 kg-COD/m[3]/day. The study includes anaerobic-MFC and aerobic-MFC integrated systems. Microbial electrode jacket dish (MEJ-dish) with hybrid dimension (HD) was invented, first time to authors' knowledge, to boost anode biofilm growth. The treatment system with MEJ+ (FAB) and MEJ- (MFC) anode are called FAB-MFC and MFC, respectively.

RESULTS: Fragmented variable anode biofilm thickness was observed in FAB than MFC. The FAB-MFC (FAB+) simple technique increases the anode biofilm thickness by ~ 5 times MFC. Due to HD the anode biofilm was fragmented in FAB+ system than MFC. At the end of each treatment cycle, voltage drops. All FAB+ integrated systems reduced voltage drop relative to MFC. FAB reduces voltage drops better than MFC in anaerobic-MFC from 6 to 20 mV and aerobic-MFC from 35-47 mV at 1 kΩ external load. The highest power density was achieved by FAB in anaerobic-MFC (FAB = 104 mW/m[2], MFC = 98 mW/m[2]) and aerobic-MFC integrated system (FAB = 59 mW/m[2], MFC = 42 mW/m[2]).

CONCLUSIONS: The ∆COD and CE between FAB and MFC could not be concluded because both setups were inserted in the same reactor. The integrated system COD removal (78-97%) was higher than the solitary MFC treatment (68-78%). This study findings support the FAB+ integrated system could be applied for real applications and improve performance. However, it might depend on influent COD, the microbial nature, and ∆COD in FAB+ and MFC, which requires further study.},
}

@article {pmid38646063,
year = {2024},
author = {Toma, TT and Wang, Y and Gahlmann, A and Acton, ST},
title = {DeepSeeded: Volumetric Segmentation of Dense Cell Populations with a Cascade of Deep Neural Networks in Bacterial Biofilm Applications.},
journal = {Expert systems with applications},
volume = {238},
number = {Pt D},
pages = {},
pmid = {38646063},
issn = {0957-4174},
abstract = {Accurate and automatic segmentation of individual cell instances in microscopy images is a vital step for quantifying the cellular attributes, which can subsequently lead to new discoveries in biomedical research. In recent years, data-driven deep learning techniques have shown promising results in this task. Despite the success of these techniques, many fail to accurately segment cells in microscopy images with high cell density and low signal-to-noise ratio. In this paper, we propose a novel 3D cell segmentation approach DeepSeeded, a cascaded deep learning architecture that estimates seeds for a classical seeded watershed segmentation. The cascaded architecture enhances the cell interior and border information using Euclidean distance transforms and detects the cell seeds by performing voxel-wise classification. The data-driven seed estimation process proposed here allows segmenting touching cell instances from a dense, intensity-inhomogeneous microscopy image volume. We demonstrate the performance of the proposed method in segmenting 3D microscopy images of a particularly dense cell population called bacterial biofilms. Experimental results on synthetic and two real biofilm datasets suggest that the proposed method leads to superior segmentation results when compared to state-of-the-art deep learning methods and a classical method.},
}

@article {pmid38644015,
year = {2024},
author = {Zhou, M and Han, Y and Zhuo, Y and Yu, F and Hu, G and Peng, D},
title = {Effect of initial ammonium concentration on a one-stage partial nitrification/anammox biofilm system: Nitrogen removal performance and the microbial community.},
journal = {Journal of environmental sciences (China)},
volume = {143},
number = {},
pages = {176-188},
doi = {10.1016/j.jes.2023.07.026},
pmid = {38644015},
issn = {1001-0742},
abstract = {One-stage partial nitrification coupled with anammox (PN/A) technology effectively reduces the energy consumption of a biological nitrogen removal system. Inhibiting nitrite-oxidizing bacteria (NOB) is essential for this technology to maintain efficient nitrogen removal performance. Initial ammonium concentration (IAC) affects the degree of inhibited NOB. In this study, the effect of the IAC on a PN/A biofilm was investigated in a moving bed biofilm reactor. The results showed that nitrogen removal efficiency decreased from 82.49% ± 1.90% to 64.57% ± 3.96% after the IAC was reduced from 60 to 20 mg N/L, while the nitrate production ratio increased from 13.87% ± 0.90% to 26.50% ± 3.76%. NOB activity increased to 1,133.86 mg N/m[2]/day after the IAC decreased, approximately 4-fold, indicating that the IAC plays an important inhibitory role in NOB. The rate-limiting step in the mature biofilm of the PN/A system is the nitritation process and is not shifted by the IAC. The analysis of the microbial community structure in the biofilm indicates that the IAC was the dominant factor in changes in community structure. Ca. Brocadia and Ca. Jettenia were the main anammox bacteria, and Nitrosomonas and Nitrospira were the main AOB and NOB, respectively. IAC did not affect the difference in growth between Ca. Brocadia and Ca. Jettenia. Thus, modulating the IAC promoted the PN/A process with efficient nitrogen removal performance at medium to low ammonium concentrations.},
}

@article {pmid38643952,
year = {2024},
author = {Zhou, W and Hao, J and Guo, Y and Zhao, C and Zhang, M and Zhang, S and Han, F},
title = {Revealing bioresponses of biofilm and flocs to salinity gradient in halophilic biofilm reactor.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {130727},
doi = {10.1016/j.biortech.2024.130727},
pmid = {38643952},
issn = {1873-2976},
abstract = {Understanding the different biological responses to salinity gradient between coexisting biofilm and flocs is crucial for regulating the ecological function of biofilm system. This study investigated performance, dynamics, and community assembly of biofilm system under 3 %-7% salinity gradient. The removal efficiency of NH4[+]-N remained stable and exceeded 93 % at 3 %-6% salinity, but decreased to below 80 % at 7 % salinity. The elevated salinity promoted the synthesis of extracellular polymer substrates, inhibited microbial respiration, and significantly regulated the microbial community structure. Compared to flocs, biofilm exhibited greater species diversity and richer Nitrosomonas. It was found diffusion limitations dominated the microbial community assembly under the salinity gradient. And microbial network revealed positive interactions predominated the microbial relationships, designating norank Spirochaetaceae, unclassified Micrococcales, Corynebacterium, and Pusillimonas as keystone species. Moreover, distinct salinity preferences in nitrogen transformation-related genes were observed. This study can improve the understanding to the regulation of biofilm systems to salt stresses.},
}

@article {pmid38643850,
year = {2024},
author = {Tabassum, N and Jeong, GJ and Jo, DM and Khan, F and Kim, YM},
title = {Attenuation of biofilm and virulence factors of Pseudomonas aeruginosa by tetramethylpyrazine-gold nanoparticles.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {106658},
doi = {10.1016/j.micpath.2024.106658},
pmid = {38643850},
issn = {1096-1208},
abstract = {Pseudomonas aeruginosa is often identified as the causative agent in nosocomial infections. Their adapted resistance makes them strong towards antimicrobial treatments. They protect and empower their survival behind strong biofilm architecture that works as their armor toward antimicrobial therapy. Additionally, P. aeruginosa generates virulence factors, contributing to chronic infection and recalcitrant phenotypic characteristics. The current study utilizes the benevolence of nanotechnology to develop an alternate technique to control the spreading of P. aeruginosa by limiting its biofilm and virulence development. This study used a natural compound, tetramethylpyrazine, to generate gold nanoparticles. Tetramethylpyrazine-gold nanoparticles (Tet-AuNPs) were presented in spherical shapes, with an average size of 168 ± 52.49 nm and a zeta potential of -12.22 ± 2.06 mV. The minimum inhibition concentration (MIC) of Tet-AuNPs that proved more than 90% effective in inhibiting P. aeruginosa was 256 μg/mL. Additionally, it also shows antibacterial activities against Staphylococcus aureus (MIC, 256 μg/mL), Streptococcus mutans (MIC, 128 μg/mL), Klebsiella pneumoniae (MIC, 128 μg/mL), Listeria monocytogenes (MIC, 256 μg/mL), and Escherichia coli (MIC, 256 μg/mL). The sub-MIC values of Tet-AuNPs significantly inhibited the early-stage biofilm formation of P. aeruginosa. Moreover, this concentration strongly affected hemolysis, protease activity, and different forms of motilities in P. aeruginosa. Additionally, Tet-AuNPs destroyed the well-established mature biofilm of P. aeruginosa. The expression of genes linked with the biofilm formation and virulence in P. aeruginosa treated with sub-MIC doses of Tet-AuNPs was shown to be significantly suppressed. Gene expression studies support biofilm- and virulence-suppressing effects of Tet-AuNPs at the phenotypic level.},
}

@article {pmid38643226,
year = {2024},
author = {Ahmed, GE and Elshahid, ZA and El-Sawy, ER and Abdel-Aziz, MS and Abdel-Aziem, A},
title = {Synthesis, biofilm formation inhibitory, and inflammation inhibitory activities of new coumarin derivatives.},
journal = {Scientific reports},
volume = {14},
number = {1},
pages = {9106},
pmid = {38643226},
issn = {2045-2322},
abstract = {Coumarins are heterocycles of great interest in the development of valuable active structures in chemistry and biological domains. The ability of coumarins to inhibit biofilm formation of Gram positive bacterium (Staphylococcus aureus), Gram negative bacterium (Escherichia coli) as well as the methicillin-resistant S. aureus (MRSA) has been previously described. In the present work, new hybrid coumarin-heterocycles have been synthesized via the reaction of coumarin-6-sulfonyl chloride and 6-aminocoumarin with different small heterocycle moieties. The biological efficacy of the new compounds was evaluated towards their ability to inhibit biofilm formation and their anti-inflammatory properties. The antimicrobial activities of the newly synthesized compounds were tested against Gram positive bacterium (S. aureus ATCC 6538), Gram negative bacterium (E. coli ATCC 25922), yeast (Candida albicans ATCC 10231) and the fungus (Aspergillus niger NRRL-A326). Compounds 4d, 4e, 4f, 6a and 9 showed significant MIC and MBC values against S. aureus, E. coli, C. albicans, and methicillin-resistant S. aureus (MRSA) with especial incidence on compound 9 which surpasses all the other compounds giving MIC and MBC values of (4.88 and 9.76 µg/mL for S. aureus), (78.13 and 312.5 µg/mL for E. coli), (9.77 and 78.13 µg/mL for C. albicans), and (39.06 and 76.7 µg/mL for MRSA), respectively. With reference to the antibiofilm activity, compound 9 exhibited potent antibiofilm activity with IC50 of 60, 133.32, and 19.67 µg/mL against S. aureus, E. coli, and MRSA, (respectively) considering the reference drug (neomycin). Out of all studied compounds, the anti-inflammatory results indicated that compound 4d effectively inhibited nitric oxide production in lipopolysaccharide-(LPS-) stimulated RAW264.7 macrophage cells, giving NO% inhibition of 70% compared to Sulindac (55.2%).},
}

@article {pmid38642854,
year = {2024},
author = {Cichos, KH and Christie, MC and Ponce, BA and Ghanem, ES},
title = {Biofilm Growth on Orthopaedic Cerclage Materials: Non-metallic Polymers Are Less Resistant to Methicillin-Resistant Staphylococcus Aureus Bacterial Adhesion.},
journal = {The Journal of arthroplasty},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.arth.2024.04.042},
pmid = {38642854},
issn = {1532-8406},
abstract = {INTRODUCTION: Data on bacterial adhesion to cerclage cables is sparse. We aimed to compare five cerclage products for methicillin-resistant Staphylococcus aureus (MRSA) adhesion to determine: Are non-metallic polymer cables more resistant to bacterial adhesion than common metallic wires and cables?

MATERIALS AND METHODS: The following five cerclage products were compared: 1) monofilament stainless steel (SS) wires; 2) multifilament SS cables; 3) multifilament cobalt chrome (CoCr) cables; 4) multifilament Vitalium alloy (cobalt-chrome-molybdenum [Co-Cr-Mo]) cables; and 5) multifilament non-metallic polymer cables. Each was cut into 2 cm lengths and placed into 12-well plates. Of the wells, five were wire or cables in trypticase soy broth (TSB) with MRSA, with the remaining wells being appropriate controls incubated for 24 hours at 37 degrees C and 5% CO2 with shaking. Wires and cables were prepared, and randomly imaged via scanning electron microscopy (SEM), with bacterial counts performed on 3 images of 3 different wires or cables per study group. The SEM technician and counting investigator were blinded. Additionally, SS wire and polymer cables were analyzed by microcalorimetry for metabolic activity and bacterial load.

RESULTS: Bacterial attachment differed significantly between study groups in the middle section (P = 0.0003). Post-hoc comparison showed no difference between groups individually (all P > 0.05) apart from polymer cables (median 551 bacteria) having significantly increased attached bacteria compared to the Vitallium alloy cable (157, P = 0.0004), SS cable (101, P = 0.0004), and SS wire (211, P = 0.0004). There was no difference between polymer and CoCr cables (133, P = 0.056). Microcalorimetry supported these results, as polymer cables had a shorter time to max heat flow (6.2 versus 7.5 hours, P = 0.006), increased max heat flow (117 versus 64 uW, P = 0.045), and increased colony-forming units, indicating an increased bacterial load compared to SS wires. ConclusionThis in vitro study demonstrates that polymer cables have increased MRSA adhesion compared to common metallic wires and cables. Future studies are necessary to confirm the translation of increased bacterial adherence on polymer cables to increased rates of orthopaedic infections.},
}

@article {pmid38642681,
year = {2024},
author = {Nirmal, GR and Lin, ZC and Chiu, TS and Alalaiwe, A and Liao, CC and Fang, JY},
title = {Chemo-photothermal therapy of chitosan/gold nanorod clusters for antibacterial treatment against the infection of planktonic and biofilm MRSA.},
journal = {International journal of biological macromolecules},
volume = {268},
number = {Pt 1},
pages = {131673},
doi = {10.1016/j.ijbiomac.2024.131673},
pmid = {38642681},
issn = {1879-0003},
abstract = {Bacterial infections trigger inflammation and impede the closure of skin wounds. The misuse of antibiotics exacerbates skin infections by generating multidrug-resistant bacteria. In this study, we developed chemo-photothermal therapy (chemo-PTT) based on near-infrared (NIR)-irradiated chitosan/gold nanorod (GNR) clusters as anti-methicillin-resistant Staphylococcus aureus (MRSA) agents. The nanocomposites exhibited an average size of 223 nm with a surface charge of 36 mV. These plasmonic nanocomposites demonstrated on-demand and rapid hyperthermal action under NIR. The combined effect of positive charge and PTT by NIR-irradiated nanocomposites resulted in a remarkable inhibition rate of 96 % against planktonic MRSA, indicating a synergistic activity compared to chitosan nanoparticles or GNR alone. The nanocomposites easily penetrated the biofilm matrix. The combination of chemical and photothermal treatments by NIR-stimulated clusters significantly damaged the biofilm structure, eradicating MRSA inside the biomass. NIR-irradiated chitosan/GNR clusters increased the skin temperature of mice by 13 °C. The plasmonic nanocomposites induced negligible skin irritation in vivo. In summary, this novel nanosystem demonstrated potent antibacterial effects against planktonic and biofilm MRSA, showcasing the possible efficacy in treating skin infections.},
}

@article {pmid38642641,
year = {2024},
author = {Savadiya, B and Pandey, G and Misra, SK},
title = {Remediation of Pharmacophoric Laboratory Waste by using Biodegradable Carbon Nanoparticles of Bacterial Biofilm Origin.},
journal = {Environmental research},
volume = {},
number = {},
pages = {118969},
doi = {10.1016/j.envres.2024.118969},
pmid = {38642641},
issn = {1096-0953},
abstract = {Research laboratories generate a broad range of hazardous pharmacophoric chemical contaminants, from drugs to dyes used during various experimental procedures. In the recent past, biological methods have demonstrated great potential in the remediation of such contaminants. However, the presence of pharmacophoric chemicals containing antibiotics, xenobiotics, and heavy metals suppresses the growth and survivability of used microbial agents, thus decreasing the overall efficiency of biological remediation processes. Bacterial biofilm is a natural arrangement to counter some of these inhibitions but its use in a systemic manner, portable devices, and pollutant remediation plants post serious challenges. This could be countered by synthesizing a biodegradable carbon nanoparticle from bacterial biofilm. In this study, extracellular polymeric substance-based carbon nanoparticles (Bio-EPS-CNPs) were synthesized from bacterial biofilm derived from Bacillus subtilis NCIB 3610, as a model bacterial system. The produced Bio-EPS-CNPs were investigated for physiochemical properties by dynamic light scattering, optical, Fourier-transformed infrared, and Raman spectroscopy techniques, whereas X-ray diffraction study, scanning electron microscopy, and transmission electron microscopy were used to investigate structural and morphological features. The Bio-EPS-CNPs exhibited negative surface charge with spherical morphology having a uniform size of sub-100 nm. The maximum remediation of some laboratory-produced pharmacophoric chemicals was achieved through a five-round scavenging process and confirmed by UV/Vis spectroscopic analysis with respect to the used pharmacophore. This bioinspired remediation of used pharmacophoric chemicals was achieved through the mechanism of surface adsorption via hydrogen bonding and electrostatic interactions, as revealed by different characterizations. Further experiments were performed to investigate the effects of pH, temperature, stirring, and the protocol of scavenging to establish Bio-EPS-CNP as a possible alternative to be used in research laboratories for efficient removal of pharmacophoric chemicals by incorporating it in a portable, filter-based device.},
}

@article {pmid38642171,
year = {2024},
author = {Araujo, TT and Dionizio, A and Carvalho, TS and Boas Feitosa, CMV and Vertuan, M and Câmara, JVF and Henrique-Silva, F and Marchetto, R and Chiaratti, MR and Santos, AC and Alves, LO and Ferro, M and Buzalaf, MAR},
title = {Acquired enamel pellicle and biofilm engineering with a combination of acid-resistant proteins (CaneCPI-5, StN15, and Hemoglobin) for enhanced protection against dental caries - in vivo and in vitro investigations.},
journal = {Clinical oral investigations},
volume = {28},
number = {5},
pages = {261},
pmid = {38642171},
issn = {1436-3771},
support = {2019/08032-5//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; 2019/26070-1//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; 302371/2018-4 ; 304554/2023-5//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; },
abstract = {OBJECTIVE: This study was designed in two-legs. In the in vivo, we explored the potential of a rinse solution containing a combination (Comb) of 0.1 mg/mL CaneCPI-5 (sugarcane-derive cystatin), 1.88 × 10[- 5]M StN15 (statherin-derived peptide) and 1.0 mg/mL hemoglobin (Hb) to change the protein profile of the acquired enamel pellicle(AEP) and the microbiome of the enamel biofilm. The in vitro, was designed to reveal the effects of Comb on the viability and bacterial composition of the microcosm biofilm, as well as on enamel demineralization.

MATERIALS AND METHODS: In vivo study, 10 participants rinsed (10mL,1 min) with either deionized water (H2O-control) or Comb. AEP and biofilm were collected after 2 and 3 h, respectively, after rinsing. AEP samples underwent proteomics analysis, while biofilm microbiome was assessed via 16 S-rRNA Next Generation Sequencing(NGS). In vitro study, a microcosm biofilm protocol was employed. Ninety-six enamel specimens were treated with: 1)Phosphate-Buffered Solution-PBS(negative-control), 2)0.12%Chlorhexidine, 3)500ppmNaF and 4)Comb. Resazurin, colony-forming-units(CFU) and Transversal Microradiography(TMR) were performed.

RESULTS: The proteomic results revealed higher quantity of proteins in the Comb compared to control associated with immune system response and oral microbial adhesion. Microbiome showed a significant increase in bacteria linked to a healthy microbiota, in the Comb group. In the in vitro study, Comb group was only efficient in reducing mineral-loss and lesion-depth compared to the PBS.

CONCLUSIONS: The AEP modification altered the subsequent layers, affecting the initial process of bacterial adhesion of pathogenic and commensal bacteria, as well as enamel demineralization.

CLINICAL RELEVANCE: Comb group shows promise in shaping oral health by potentially introducing innovative approaches to prevent enamel demineralization and deter tooth decay.},
}

@article {pmid38641883,
year = {2024},
author = {Pethe, A and Debnath, M},
title = {Wastewater treatment using moving bed biofilm reactor technology: a case study of ceramic industry.},
journal = {Water environment research : a research publication of the Water Environment Federation},
volume = {96},
number = {4},
pages = {e11026},
doi = {10.1002/wer.11026},
pmid = {38641883},
issn = {1554-7531},
support = {EF/2019-20/QEO4-01//Manipal University Jaipur/ ; },
abstract = {Biological approaches and coagulation are frequently used to reduce the chemical oxygen demand (COD) for treatment of ceramic effluent water. The technology known as the moving bed biofilm reactor (MBBR) can accomplish this goal. Further, the process of emulsification-aided innovative MBBR using biosurfactants can be proposed for ceramic effluent treatment. In a step-by-step upgrading scheme, biosurfactants and a consortia of halophilic and halotolerant microbial culture was utilized for the treatment of the effluent water. Over the course of 21 days, a progressive decrease in COD of up to 95.79% was achieved. Over the next 48 h period, the biochemical oxygen demand (BOD) was reduced by 98.3%, while total suspended solids (TSS) decreased by 79.41%. With the use of this innovative MBBR technology, biofilm formation accelerated, lowering the COD, BOD, and TSS levels. This allows treated water to be used for further research on recycling it back into the ceramics sector and repurposing it for agricultural purposes. PRACTITIONER POINTS: Implementation of modified MBBR technology for the treatment of effluent water. Biosurfactants could reduce in the organic and inorganic loads. Increase in MLSS values with COD removal observed. The plant operations without the use of chemical coagulants was effective with biosurfactants. Biofilm formation on carriers was scraped and the presence of surfactin and rhamnolipid was confirmed.},
}

@article {pmid38641593,
year = {2024},
author = {Raj, K and Paul, D and Rishi, P and Shukla, G and Dhotre, D and YogeshSouche, },
title = {Decoding the role of oxidative stress resistance and alternative carbon substrate assimilation in the mature biofilm growth mode of Candida glabrata.},
journal = {BMC microbiology},
volume = {24},
number = {1},
pages = {128},
pmid = {38641593},
issn = {1471-2180},
abstract = {BACKGROUND: Biofilm formation is viewed as a vital mechanism in C. glabrata pathogenesis. Although, it plays a significant role in virulence but transcriptomic architecture and metabolic pathways governing the biofilm growth mode of C. glabrata remain elusive. The present study intended to investigate the genes implicated in biofilm growth phase of C. glabrata through global transcriptomic approach.

RESULTS: Functional analysis of Differentially expressed genes (DEGs) using gene ontology and pathways analysis revealed that upregulated genes are involved in the glyoxylate cycle, carbon-carbon lyase activity, pre-autophagosomal structure membrane and vacuolar parts whereas, down- regulated genes appear to be associated with glycolysis, ribonucleoside biosynthetic process, ribosomal and translation process in the biofilm growth condition. The RNA-Seq expression of eight selected DEGs (CgICL1, CgMLS1, CgPEP1, and CgNTH1, CgERG9, CgERG11, CgTEF3, and CgCOF1) was performed with quantitative real-time PCR (RT-qPCR). The gene expression profile of selected DEGs with RT-qPCR displayed a similar pattern of expression as observed in RNA-Seq. Phenotype screening of mutant strains generated for genes CgPCK1 and CgPEP1, showed that Cgpck1∆ failed to grow on alternative carbon substrate (Glycerol, Ethanol, Oleic acid) and similarly, Cgpep1∆ unable to grow on YPD medium supplemented with hydrogen peroxide. Our results suggest that in the absence of glucose, C. glabrata assimilate glycerol, oleic acid and generate acetyl coenzyme-A (acetyl-CoA) which is a central and connecting metabolite between catabolic and anabolic pathways (glyoxylate and gluconeogenesis) to produce glucose and fulfil energy requirements.

CONCLUSIONS: The study was executed using various approaches (transcriptomics, functional genomics and gene deletion) and it revealed that metabolic plasticity of C. glabrata (NCCPF-100,037) in biofilm stage modulates its virulence and survival ability to counter the stress and may promote its transition from commensal to opportunistic pathogen. The observations deduced from the present study along with future work on characterization of the proteins involved in this intricate process may prove to be beneficial for designing novel antifungal strategies.},
}

@article {pmid38641269,
year = {2024},
author = {Youssef Moustafa, AM and Fawzy, MM and Kelany, MS and Hassan, YA and Elsharaawy, RFM and Mustafa, FHA},
title = {Synthesis of new quaternized chitosan Schiff bases and their N-alkyl derivatives as antimicrobial and anti-biofilm retardants in membrane technology.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {131635},
doi = {10.1016/j.ijbiomac.2024.131635},
pmid = {38641269},
issn = {1879-0003},
abstract = {New quaternized salicylidene chitosan Schiff bases (QSCSBs) and their N-octyl derivatives (OQCs) have been synthesized and characterized, aiming to develop innovative antimicrobial and anti-biofilm agents. This research holds immense potential, as these compounds could be utilized as anti-biofouling additives in membrane technology in the future. The synthesis involved the modification of low molecular-weight-chitosan (LMC) through simultaneous Schiff base formation and quaternization processes to create QSCSBs. Subsequently, QSCSBs were catalytically reduced to form quaternized N-benzyl chitosan (QBCs) intermediates, which then underwent nucleophilic substitution reactions affording N-octyl quaternized chitosans (OQCs). Characterization techniques such as elemental, spectral, and microscopic analyses were used to confirm the successful synthesis of these materials. As membrane technology relies on surface charge, QSCSBs and OQCs with large zeta potentials could be used as positively charged additives. Moreover, SEM image revealed the regular distribution of pores and voids across the additives' surfaces raises intriguing questions about their implications for membrane performance. Meanwhile, the superior antibacterial and antibiofilm potential of these materials, particularly QSCSB2 and OQC2, indicate that the utilization of these compounds as anti-biofouling additives in membrane technology could significantly improve the performance and longevity of membranes used in various applications such as water treatment and desalination.},
}

@article {pmid38640776,
year = {2024},
author = {Ganesh, PS},
title = {4-hydroxy-3-methoxybenzaldehyde causes attrition of biofilm formation and quorum sensing-associated virulence factors of Streptococcus mutans.},
journal = {Archives of oral biology},
volume = {163},
number = {},
pages = {105976},
doi = {10.1016/j.archoralbio.2024.105976},
pmid = {38640776},
issn = {1879-1506},
abstract = {OBJECTIVE: The present study investigated the effects of 4-hydroxy-3-methoxybenzaldehyde (4-H-3-MB) against Streptococcus mutans (S. mutans) using an in vitro cariogenic biofilm model.

DESIGN: The antimicrobial susceptibility of biofilm-forming S. mutans was evaluated by disc diffusion method. In vitro investigations were performed using crystal violet staining assay (biofilm assay), exopolysaccharide (EPS) assay, acid production, growth curve analysis, optical microscopic, and FE-SEM analyses to determine the antibiofilm activity of 4-H-3-MB.

RESULTS: S. mutans (SDC-05) was resistant to ampicillin, piperacillin/tazobactam and ceftriaxone, whereas the other strains of S. mutans (SDC-01, 02, 03 and SDC-04) were sensitive to all the antibiotics tested. 4-H-3-MB showed promising antibiofilm activity on S. mutans UA159 (79.81 %, 67.76 % and 56.31 %) and S. mutans SDC-05 (77.00 %, 59.48 % and 48.22 %) at the lowest concentration of 0.2, 0.1, 0.05 mg/ml. 4-H-3-MB did not inhibit bacterial growth even at concentrations 0.2 mg/ml. Similarly, 4-H-3-MB led to significant attrition in exopolysaccharide (EPS) and acid production by S. mutans UA159 and S. mutans (SDC-05) at the concentration of 0.2, 0.1 mg/ml, respectively. Optical microscopy and FE-SEM analysis 4-H-3-MB reduced the biofilm thickness of S. mutans UA159 and S. mutans SDC-05 relative to the untreated specimens.

CONCLUSION: 4-H-3-MB significantly inhibited biofilm formation by S. mutans in a dose-dependent manner. Hence, our findings indicate that the active principle of 4-H-3-MB could be used as a biofilm inhibiting agent against S. mutans.},
}

@article {pmid38640499,
year = {2024},
author = {Jakkampudi, T and Lin, Q and Mitra, S and Vijai, A and Qin, W and Kang, A and Chen, J and Ryan, E and Wang, R and Gong, Y and Heinrich, F and Song, J and Di, YP and Tristram-Nagle, S},
title = {Correction to "Lung SPLUNC1 Peptide Derivatives in the Lipid Membrane Headgroup Kill Gram-Negative Planktonic and Biofilm Bacteria".},
journal = {Biomacromolecules},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.biomac.4c00501},
pmid = {38640499},
issn = {1526-4602},
}

@article {pmid38639582,
year = {2024},
author = {Upadhyay, A and Pal, D and Kumar, A},
title = {Molecular drilling to combat salmonella typhi biofilm using L-Asparaginase via multiple targeting process.},
journal = {Expert opinion on therapeutic targets},
volume = {},
number = {},
pages = {},
doi = {10.1080/14728222.2024.2344699},
pmid = {38639582},
issn = {1744-7631},
abstract = {OBJECTIVES: Salmonella Typhibiofilm condition is showing as a major public health problem due to the developmentof antibiotic resistance and less available druggable target proteins.Therefore, we aimed to identify some more druggable targets of S. Typhibiofilm using computational drilling at the genome/proteome level so that thetarget shortage problem could be overcome and more antibiofilm agents could bedesigned in the future against the disease.

METHODS: We performed protein-protein dockingand interaction analysis between the homological identified target proteins of S.Typhi biofilm and a therapeutic protein L-Asparaginase.

RESULTS: We have identified some druggabletargets CsgD, BcsA, OmpR, CsgG, CsgE, and CsgF in S.Typhi. These targetsshowed high-binding affinity BcsA (-219.8 Kcal/mol) >csgF (-146.52 Kcal/mol) >ompR (-135.68 Kcal/mol) >CsgE (-134.66 Kcal/mol) >CsgG (-113.81 Kcal/mol) >CsgD(-95.39 Kcal/mol) with therapeutic enzyme L-Asparaginase through varioushydrogen-bonds and salt-bridge. We found six proteins of S. Typhi biofilm from the Csg family as druggable multiple targets.

CONCLUSION: This study provides insight intothe idea of identification of new druggable targets and their multipletargeting with L-Asparaginase to overcome target shortage in S. Typhibiofilm-mediated infections. Results further indicated that L-Asparaginasecould potentially be utilized as an antibiofilm biotherapeutic agent against S.Typhi.},
}

@article {pmid38639133,
year = {2024},
author = {Mamba, PP and Msagati, TAM and Mamba, BB and Motsa, MM and Nkambule, TTI},
title = {The removal of pathogenic bacteria and dissolved organic matter from freshwater using microporous membranes: insights into biofilm formation and fouling reversibility.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-17},
doi = {10.1080/08927014.2024.2339438},
pmid = {38639133},
issn = {1029-2454},
abstract = {Pathogenic bacteria in drinking-water pose a health risk to consumers, as they compromise the quality of portable water. Chemical disinfection of water containing dissolved organic matter (DOM) causes harmful disinfection by-products. In this work, 4-hydroxybenzoic acid (4-HBA) blended polyethersulfone membranes were fabricated and characterised using microscopic and spectroscopic techniques. The membranes were evaluated for the removal of bacteria and DOM from synthetic and environmental water. Permeate flux increased from 287.30 to 374.60 l m[-2] h[-1] at 3 bars when 4-HBA increased from 0 to 1.5 wt.%, suggesting that 4-HBA influenced the membrane's affinity for water. Furthermore, 4-HBA demonstrated antimicrobial properties by inhibiting bacterial growth. The membrane with 1 wt.% 4-HBA recorded 99.4 and 100% bacteria removal in synthetic and environmental water, respectively. Additionally, DOM removal of 55-73% was achieved. A flux recovery ratio (FRR) of 94.6% was obtained when a mixture of bacteria and humic acid was filtered, implying better fouling layer reversibility during cleaning. Furthermore, 100% FRR was achieved when a multimedia granular filtration step was installed prior to membrane filtration. The results illustrated that the membranes had a high permeate flux with low irreversible fouling. This indicated the potential of the membranes in treating complex feed streams using simple cleaning protocols.},
}

@article {pmid38638833,
year = {2024},
author = {Zhang, W and He, M and Kong, N and Niu, Y and Li, A and Yan, Y},
title = {Study on the inhibition activity and mechanism of Tanreqing against Klebsiella pneumoniae biofilm formation in vitro and in vivo.},
journal = {Frontiers in cellular and infection microbiology},
volume = {14},
number = {},
pages = {1368450},
pmid = {38638833},
issn = {2235-2988},
abstract = {OBJECTIVE: To evaluate the antibacterial effect of Tanreqing (TRQ) against K. pneumoniae and its inhibition activity on bacterial biofilm formation in vitro and in vivo, and to explore the mechanism of the inhibitory effects of TRQ on K. pneumoniae biofilm formation.

METHODS: An in vitro biofilm model of K. pneumoniae was established, and the impact of TRQ on biofilm formation was evaluated using crystal violet staining and scanning electron microscopy (SEM). Furthermore, the clearance effect of TRQ against K. pneumoniae in the biofilm was assessed using the viable plate counting method; q-RT PCR was used to evaluate the inhibitory effect of different concentrations of TRQ on the expression of biofilm-related genes in Klebsiella pneumoniae; The activity of quorum sensing signal molecule AI-2 was detected by Vibrio harveyi bioluminescence assay; Meanwhile, a guinea pig lung infection model of Klebsiella pneumoniae was constructed, and after treated with drugs, pathological analysis of lung tissue and determination of bacterial load in lung tissue were performed. The treatment groups included TRQ group, imipenem(IPM) group, TRQ+IPM group, and sterile saline group as the control.

RESULTS: The formation of K. pneumoniae biofilm was significantly inhibited by TRQ in vitro experiments. Furthermore, when combined with IPM, the clearance of K. pneumoniae in the biofilm was notably increased compared to the TRQ group and IPM group alone. q-RT PCR analysis revealed that TRQ down-regulated the expression of genes related to biofilm formation in K. pneumoniae, specifically luxS, wbbm, wzm, and lsrK, and also inhibited the activity of AI-2 molecules in the bacterium. In vivo experiments demonstrated that TRQ effectively treated guinea pig lung infections, resulting in reduced lung inflammation. Additionally, when combined with IPM, there was a significant reduction in the bacterial load in lung tissue.

CONCLUSION: TRQ as a potential therapeutic agent plays a great role in the treatment of K. pneumoniae infections, particularly in combination with conventional antibiotics. And TRQ can enhanced the clearance effect on the bacterium by inhibiting the K. pneumoniae biofilm formation, which provided experimental evidence in support of clinical treatment of TRQ against K. pneumoniae infections.},
}

@article {pmid38637715,
year = {2024},
author = {Taglialegna, A},
title = {Shaking up that sick feeling with biofilm sugars.},
journal = {Nature reviews. Microbiology},
volume = {},
number = {},
pages = {},
pmid = {38637715},
issn = {1740-1534},
}

@article {pmid38637093,
year = {2024},
author = {Melian, C and Ploper, D and Chehín, R and Vignolo, G and Castellano, P},
title = {Impairment of Listeria monocytogenes biofilm developed on industrial surfaces by Latilactobacillus curvatus CRL1579 bacteriocin.},
journal = {Food microbiology},
volume = {121},
number = {},
pages = {104491},
doi = {10.1016/j.fm.2024.104491},
pmid = {38637093},
issn = {1095-9998},
abstract = {The effect of lactocin AL705, bacteriocin produced by Latilactobacillus (Lat.) curvatus CRL1579 against Listeria biofilms on stainless steel (SS) and polytetrafluoroethylene (PTFE) coupons at 10 °C was investigated. L. monocytogenes FBUNT showed the greatest adhesion on both surfaces associated to the hydrophobicity of cell surface. Partially purified bacteriocin (800 UA/mL) effectively inhibited L. monocytogenes preformed biofilm through displacement strategy, reducing the pathogen by 5.54 ± 0.26 and 4.74 ± 0.05 log cycles at 3 and 6 days, respectively. The bacteriocin-producer decreased the pathogen biofilm by ∼2.84 log cycles. Control and Bac[-] treated samples reached cell counts of 7.05 ± 0.18 and 6.79 ± 0.06 log CFU/cm[2] after 6 days of incubation. Confocal scanning laser microscopy (CLSM) allowed visualizing the inhibitory effect of lactocin AL705 on L. monocytogenes preformed biofilms under static and hydrodynamic flow conditions. A greater effect of the bacteriocin was found at 3 days independently of the surface matrix and pathogen growth conditions at 10 °C. As a more realistic approach, biofilm displacement strategy under continuous flow conditions showed a significant loss of biomass, mean thickness and substratum coverage of pathogen biofilm. These findings highlight the anti-biofilm capacity of lactocin AL705 and their potential application in food industries.},
}

@article {pmid38637079,
year = {2024},
author = {Abi Assaf, J and Holden, ER and Trampari, E and Webber, MA},
title = {Common food preservatives impose distinct selective pressures on Salmonella Typhimurium planktonic and biofilm populations.},
journal = {Food microbiology},
volume = {121},
number = {},
pages = {104517},
doi = {10.1016/j.fm.2024.104517},
pmid = {38637079},
issn = {1095-9998},
abstract = {Food preservatives are crucial in controlling microbial growth in processed foods to maintain food safety. Bacterial biofilms pose a threat in the food chain by facilitating persistence on a range of surfaces and food products. Cells in a biofilm are often highly tolerant of antimicrobials and can evolve in response to antimicrobial exposure. Little is known about the efficacy of preservatives against biofilms and their potential impact on the evolution of antimicrobial resistance. In this study we investigated how Salmonella enterica serovar Typhimurium responded to subinhibitory concentrations of four food preservatives (sodium chloride, potassium chloride, sodium nitrite or sodium lactate) when grown planktonically and in biofilms. We found that each preservative exerted a unique selective pressure on S. Typhimurium populations. There was a trade-off between biofilm formation and growth in the presence of three of the four preservatives, where prolonged preservative exposure resulted in reduced biofilm biomass and matrix production over time. All three preservatives selected for mutations in global stress response regulators rpoS and crp. There was no evidence for any selection of cross-resistance to antibiotics after preservative exposure. In conclusion, we showed that preservatives affect biofilm formation and bacterial growth in a compound specific manner. We showed trade-offs between biofilm formation and preservative tolerance, but no antibiotic cross-tolerance. This indicates that bacterial adaptation to continuous preservative exposure, is unlikely to affect food safety or contribute to antibiotic resistance.},
}