@article {pmid39714542,
year = {2024},
author = {Zhang, K and Li, Q and Gong, C and Mao, H and Han, D},
title = {Inhibitory effect of andrographolide on the expression of key regulatory genes in Staphylococcus epidermidis biofilm formation.},
journal = {Journal of molecular histology},
volume = {56},
number = {1},
pages = {53},
pmid = {39714542},
issn = {1567-2387},
support = {No.: ZR2021QH055//Natural Science Foundation of Shandong Province/ ; No.: ZR2021QH055//Natural Science Foundation of Shandong Province/ ; No.: ZR2021QH055//Natural Science Foundation of Shandong Province/ ; No.: ZR2021QH055//Natural Science Foundation of Shandong Province/ ; No.: ZR2021QH055//Natural Science Foundation of Shandong Province/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Staphylococcus epidermidis/drug effects/genetics/physiology ; *Diterpenes/pharmacology ; *Gene Expression Regulation, Bacterial/drug effects ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics/metabolism ; Bacterial Adhesion/drug effects ; Genes, Regulator ; },
abstract = {The purpose of this study was to explore the inhibitory effect of andrographolide on the expression of key regulatory genes involved in the biofilm formation of Staphylococcus epidermidis (SE). Taking the film-producing strain Staphylococcus epidermidis SE1457 as the research object, the effect of andrographolide on the formation of Staphylococcus epidermidis biofilms was analyzed via crystal violet staining, and biofilm models of SE adhesion, aggregation and maturity were established in vitro. RT‒PCR was used to detect the effects of the expression of icaA-, atlE-, aap- and luxS-related genes of andrographolide on biofilm formation in SE. Congo red qualitative test to evaluate the ability of andrographolide to inhibit biofilm formation of Staphylococcus epidermidis. Compared with that of the control group, the light absorption value of the low- and high-concentration andrographolide groups was significantly lower, and the light absorption value of the high-concentration andrographolide group was significantly lower than that of the low-concentration andrographolide group. The levels of key genes involved in the adhesion, aggregation and maturation of icaA, atlE, aap and luxS in group C were greater than those in group B. The biofilm-forming ability of SE in group A was strong, and the colonies were obviously black. The colony in the direction of the arrow in group B was red, and the SE biofilm was inhibited. Most of the colonies in group C were red. SE biofilms were significantly inhibited. Andrographolide inhibits SE biofilm formation, and its mechanism may involve inhibition of the expression of the related genes icaA, atlE, aap and luxS.},
}

*Biofilms/drug effects/growth & development
*Staphylococcus epidermidis/drug effects/genetics/physiology
*Diterpenes/pharmacology
*Gene Expression Regulation, Bacterial/drug effects
Anti-Bacterial Agents/pharmacology
Bacterial Proteins/genetics/metabolism
Bacterial Adhesion/drug effects
Genes, Regulator

@article {pmid39714182,
year = {2024},
author = {Willett, JLE and Dunny, GM},
title = {Insights into ecology, pathogenesis, and biofilm formation of Enterococcus faecalis from functional genomics.},
journal = {Microbiology and molecular biology reviews : MMBR},
volume = {},
number = {},
pages = {e0008123},
doi = {10.1128/mmbr.00081-23},
pmid = {39714182},
issn = {1098-5557},
abstract = {SUMMARYEnterococcus faecalis is a significant resident of the gastrointestinal tract of most animals, including humans. Although generally non-pathogenic in healthy hosts, this microbe is adept at the exploitation of compromises in host immune functions, resulting in life-threatening opportunistic infections whose treatments are complicated by a high degree of intrinsic and acquired resistance to antimicrobial chemotherapy. Historically, progress in enterococcal research was limited by a lack of experimental models that replicate natural infection pathways and the relevance of in vitro studies to the natural biology of the organism. In this review, we summarize the history of enterococcal research during the 20th and early 21st centuries and describe more recent genetic and genomic tools and screens developed to address challenges in the field. We also describe how the results of recent studies reveal the importance of previously uncharacterized enterococcal genes, and we provide examples of interesting determinants that have emerged as important contributors to enterococcal biology. These factors may also serve as targets for future vaccines and chemotherapeutic agents to combat life-threatening hospital infections.},
}

@article {pmid39712920,
year = {2024},
author = {Tomasello, F and De Cesare, A and Valero Díaz, A},
title = {Training in quantitative microbial risk assessment of Listeria monocytogenes in processing chains: Quantification of biofilm-cells transfer integrating virulence and persistence factors.},
journal = {EFSA journal. European Food Safety Authority},
volume = {22},
number = {Suppl 1},
pages = {e221106},
pmid = {39712920},
issn = {1831-4732},
abstract = {Food safety is a global challenge, with nearly 1 in 10 people worldwide falling ill each year from consuming contaminated food. The risk is particularly high in ready-to-eat (RTE) products, which are consumed without further cooking to eliminate harmful microorganisms. To address this, the University of Cordoba and the University of Bologna, in the framework of the EU-FORA programme, developed a training programme focused on quantitative microbial risk assessment (QMRA) for Listeria monocytogenes in RTE food processing chains, a significant public health concern due to its association with severe foodborne illnesses. The programme aimed to train the fellow in advanced food microbiology techniques, predictive modelling and comprehensive QMRA methodologies. The fellow gained hands-on experience with predictive microbiology models applied to real-world scenarios, particularly RTE meat and fish products. Activities included developing predictive models for microbial growth and conducting challenge tests to evaluate Listeria behaviour in various foods. Emphasising data collection and statistical analysis, the fellowship explores the dynamics of Listeria within the food supply chain. A case study on sliced cooked ham demonstrates QMRA's application, using Monte Carlo simulations to estimate Listeria concentrations at consumption, ultimately informing risk management strategies. This initiative aimed to increase the number of food safety risk assessment experts in Europe, thereby enhancing public health outcomes related to foodborne diseases.},
}

@article {pmid39712885,
year = {2024},
author = {Moshaverinia, M and Sahmeddini, S and Lavaee, F and Zareshahrabadi, Z and Zomorodian, K},
title = {Corrigendum to "Antimicrobial and Anti-Biofilm Activities of Thymus fallax Essential Oil against Oral Pathogens".},
journal = {BioMed research international},
volume = {2024},
number = {},
pages = {9797835},
pmid = {39712885},
issn = {2314-6141},
abstract = {[This corrects the article DOI: 10.1155/2022/9744153.].},
}

@article {pmid39711551,
year = {2024},
author = {Bogyo, M and Upadhyay, T and Woods, E and Ahator, S and Julin, K and Faucher, F and Hollander, M and Pedowitz, N and Abegg, D and Hammond, I and Eke, I and Wang, S and Chen, S and Bennett, J and Jo, J and Lentz, C and Adibekian, A and Fellner, M},
title = {Covalent-fragment screening identifies selective inhibitors of multiple Staphylococcus aureus serine hydrolases important for growth and biofilm formation.},
journal = {Research square},
volume = {},
number = {},
pages = {},
doi = {10.21203/rs.3.rs-5494070/v1},
pmid = {39711551},
issn = {2693-5015},
abstract = {Staphylococcus aureus is a leading cause of bacteria-associated mortality worldwide. This is largely because infection sites are often difficult to localize and the bacteria forms biofilms which are not effectively cleared using classical antibiotics. Therefore, there is a need for new tools to both image and treat S. aureus infections. We previously identified a group of S. aureus serine hydrolases known as fluorophosphonate-binding hydrolases (Fphs), which regulate aspects of virulence and lipid metabolism. However, because their structures are similar and their functions overlap, it remains challenging to distinguish the specific roles of individual members of this family. In this study, we applied a high-throughput screening approach using a library of covalent electrophiles to identify inhibitors for FphB, FphE, and FphH. We identified inhibitors that irreversibly bind to the active-site serine residue of each enzyme with high potency and selectivity without requiring extensive medicinal chemistry optimization. Structural and biochemical analysis identified novel binding modes for several of the inhibitors. Selective inhibitors of FphH impaired both bacterial growth and biofilm formation while Inhibitors of FphB and FphE had no impact on cell growth and only limited impact on biofilm formation. These results suggest that all three hydrolases likely play functional, but non-equivalent roles in biofilm formation and FphH is a potential target for development of therapeutics that have both antibiotic and anti-biofilm activity. Overall, we demonstrate that focused covalent fragment screening can be used to rapidly identify highly potent and selective electrophiles targeting bacterial serine hydrolases. This approach could be applied to other classes of lipid hydrolases in diverse pathogens or higher eukaryotes.},
}

@article {pmid39711107,
year = {2025},
author = {Tang, Q and Ye, W and Chandarajoti, K and Ge, R and Lv, S and Zhang, K and Han, X and Wang, C and Bai, H and Wang, X and Zhou, W},
title = {Discovery of xanthone-based nitric oxide donors targeting biofilm clearance.},
journal = {Archiv der Pharmazie},
volume = {358},
number = {1},
pages = {e2400793},
doi = {10.1002/ardp.202400793},
pmid = {39711107},
issn = {1521-4184},
support = {2023YFD1800800//National Key Research and Development Program of China/ ; U22A20518//National Natural Science Foundation of China/ ; 32171931//National Natural Science Foundation of China/ ; },
mesh = {*Biofilms/drug effects ; *Xanthones/pharmacology/chemistry/chemical synthesis ; Animals ; Mice ; *Staphylococcus aureus/drug effects/physiology ; *Nitric Oxide Donors/pharmacology/chemical synthesis/chemistry ; *Anti-Bacterial Agents/pharmacology/chemical synthesis/chemistry ; *Microbial Sensitivity Tests ; Staphylococcal Infections/drug therapy/microbiology ; Nitric Oxide/metabolism ; Structure-Activity Relationship ; Molecular Structure ; Disease Models, Animal ; Drug Discovery ; Humans ; },
abstract = {Bacteria biofilm infection seriously challenges clinical drug therapy. Nitric oxide (NO) was reported to disperse biofilm, eliminate bacteria resistance and kill bacteria. In this study, on the basis of membrane targeting of α-mangostin (α-MG) and the dispersion effect of NO on bacteria biofilms, we designed and synthesized 30 NO donors that α-MG was conjugated with a nitrobenzene or a nitrate and other four representative reference derivatives. Compound 23 with 2-chloro-4-nitrobenzoyl introduced in the position C6 of α-MG exhibited the prominent ability to eradicate Staphylococcous aureus biofilm, and a more long-lasting and stable bactericidal effect in vitro, and lower hemolytic activity over α-MG. Moreover, a mouse wound model infected by S. aureus biofilm supported the in vivo reduced bacterial burden closely associated with the NO release from compound 23 that exerted a dispersing effect on biofilms. Therefore, our design strategy can provide a promising and effective solution to intervene in biofilm infection with high specificity.},
}

*Biofilms/drug effects
*Xanthones/pharmacology/chemistry/chemical synthesis
Animals
Mice
*Staphylococcus aureus/drug effects/physiology
*Nitric Oxide Donors/pharmacology/chemical synthesis/chemistry
*Anti-Bacterial Agents/pharmacology/chemical synthesis/chemistry
*Microbial Sensitivity Tests
Staphylococcal Infections/drug therapy/microbiology
Nitric Oxide/metabolism
Structure-Activity Relationship
Molecular Structure
Disease Models, Animal
Drug Discovery
Humans

@article {pmid39710928,
year = {2024},
author = {Teymouri, S and Pourhajibagher, M and Bahador, A},
title = {Therapeutic Potential of Emodin: A Mini-Review of Its Anti-Biofilm and Antimicrobial Effects.},
journal = {Infectious disorders drug targets},
volume = {},
number = {},
pages = {},
doi = {10.2174/0118715265329198241105030008},
pmid = {39710928},
issn = {2212-3989},
abstract = {The resistance of biofilms to antimicrobial agents presents numerous challenges. The formation of biofilms leads to enhanced resistance to adverse environmental condi-tions, as well as to antimicrobial agents. Natural compounds have been of interest as po-tential therapeutic agents. Emodin, a natural anthraquinone compound, has recently at-tracted attention for its potential as a broad-spectrum antimicrobial agent. This ability could potentially help combat biofilm-associated infections and enhance the effectiveness of an-timicrobial therapies. This review was carried out to evaluate the effects of emodin on mi-crobial biofilms, determine its effectiveness in inhibiting and reducing biofilm formation, eradicate biofilms, and examine its antimicrobial effects. Our study shows that the use of emodin as an additional therapeutic agent in combating microbial biofilms holds consider-able promise. As researchers continue to investigate how emodin interacts with microbial biofilms, there is excitement about the potential applications of this natural compound in addressing biofilm-related issues. However, it is suggested to pay more attention to evalu-ating the effects of emodin on microbial biofilms in future studies.},
}

@article {pmid39710922,
year = {2024},
author = {Pourhajibagher, M and Bahador, A},
title = {In vitro Anti-biofilm and Anti-adhesion Effects of Lactic Acid Bacteria- derived Biosurfactants against Streptococcus mutans.},
journal = {Infectious disorders drug targets},
volume = {},
number = {},
pages = {},
doi = {10.2174/0118715265336536241014072854},
pmid = {39710922},
issn = {2212-3989},
abstract = {INTRODUCTION: Biosurfactants are naturally occurring compounds with various ap-plications, biodegradable, non-toxic, and effective in different conditions. This study fo-cuses on the extraction and evaluation of biosurfactants produced by five strains of lactic acid bacteria [LAB] for their potential to inhibit biofilm formation and adhesion by Strep-tococcus mutans.

METHODS: The strains of LAB-producing biosurfactants such as Lactobacillus salivarius, L. acidophilus, L. plantarum, L. casei, and L. rhamnosus were confirmed by the hemolysis test. The presence of biosurfactants derived from LAB strains and their molecular compo-sition were confirmed, and their cellular toxicity, minimum inhibitory concentration [MIC], and minimum bactericidal concentration [MBC] were investigated. Ultimately, the anti-biofilm and anti-adhesive activities of LAB-derived biosurfactants against S. mutans were determined. Eventually, the effect of biosurfactants on the changes in gene expression associated with biofilm formation of S. mutans was assessed. All the LAB strains used in this study were biosurfactant producers. The LAB-derived bi-osurfactants exhibited no cytotoxicity towards the human gingival fibroblast [HGF] cell line. According to the results, the lowest and highest MIC values were observed in the biosurfactants derived from L. rhamnosus and L. plantarum at 0.78 mg/mL and 6.25 mg/mL, respectively. The MBC values for the biosurfactants derived from L. rhamnosus, L. casei, L. salivarius, L. acidophilus, and L. plantarum were 3.12, 3.12, 6.25, 12.5, and 12.5 mg/mL, respectively. The LAB-derived biosurfactants at MBC concentrations exhib-ited significant inhibitory effects on biofilm formation and adhesion of S. mutans [P<0.05]. The highest anti-biofilm and anti-adhesion activities were attributed to the biosurfactants derived from L. plantarum, which were not significantly different from the 0.2% chlorhex-idine as a positive control group [P>0.05]. Moreover, all biosurfactants could significantly decrease the gene expression level of gtfB [P>0.05].

RESULTS: The study found that LAB-derived biosurfactants exhibit significant anti-adhesion and anti-biofilm activities against S. mutans without any observed cellular toxicity towards HGF cells.

CONCLUSION: These promising bioactive compounds can be utilized as natural antimicrobial agents and biofilm inhibitors to prevent microbial biofilm formation and adhesion in vari-ous dental applications, offering a safe and effective alternative for controlling dental bio-films and improving oral health outcomes.},
}

@article {pmid39710670,
year = {2024},
author = {Al-Madboly, LA and Aboulmagd, A and El-Salam, MA and Kushkevych, I and El-Morsi, RM},
title = {Microbial enzymes as powerful natural anti-biofilm candidates.},
journal = {Microbial cell factories},
volume = {23},
number = {1},
pages = {343},
pmid = {39710670},
issn = {1475-2859},
mesh = {*Biofilms/drug effects ; Bacteria/drug effects/enzymology ; Aspergillus niger/enzymology ; Anti-Bacterial Agents/pharmacology ; Glycoside Hydrolases/metabolism ; Carbohydrate Dehydrogenases/metabolism ; },
abstract = {Bacterial biofilms pose significant challenges, from healthcare-associated infections to biofouling in industrial systems, resulting in significant health impacts and financial losses globally. Classic antimicrobial methods often fail to eradicate sessile microbial communities within biofilms, requiring innovative approaches. This review explores the structure, formation, and role of biofilms, highlighting the critical importance of exopolysaccharides in biofilm stability and resistance mechanisms. We emphasize the potential of microbial enzymatic approaches, particularly focusing on glycosidases, proteases, and deoxyribonucleases, which can disrupt biofilm matrices effectively. We also delve into the importance of enzymes such as cellobiose dehydrogenase, which disrupts biofilms by degrading polysaccharides. This enzyme is mainly sourced from Aspergillus niger and Sclerotium rolfsii, with optimized production strategies enhancing its efficacy. Additionally, we explore levan hydrolase, alginate lyase, α-amylase, protease, and lysostaphin as potent antibiofilm agents, discussing their microbial origins and production optimization strategies. These enzymes offer promising avenues for combating biofilm-related challenges in healthcare, environmental, and industrial settings. Ultimately, enzymatic strategies present environmentally friendly solutions with high potential for biofilm management and infection control.},
}

*Biofilms/drug effects
Bacteria/drug effects/enzymology
Aspergillus niger/enzymology
Anti-Bacterial Agents/pharmacology
Glycoside Hydrolases/metabolism
Carbohydrate Dehydrogenases/metabolism

@article {pmid39710222,
year = {2024},
author = {Zheng, Y and Wang, M and Zhang, X and Wu, Z and Gao, L},
title = {A bacteria-responsive nanoplatform with biofilm dispersion and ROS scavenging for the healing of infected diabetic wounds.},
journal = {Acta biomaterialia},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.actbio.2024.12.042},
pmid = {39710222},
issn = {1878-7568},
abstract = {Delayed wound healing in patients with diabetes remains a major health challenge worldwide. Uncontrolled bacterial infection leads to excessive production of reactive oxygen species (ROS) and persistent inflammatory responses, which seriously hinder conventional physiological healing processes after injury. Biofilms, as protective barriers for bacteria, pose a critical obstacle to effective bacterial eradication. Herein, an innovative therapeutic nanoplatform with in situ antibacterial and antioxidant properties is developed for enhancing infected diabetic wound healing. The enrichment of phenylboronic acid (PBA) moieties on the nanoplatform enhances biofilm penetration, actively anchors and aggregates the enclosed bacteria through the "multivalent effect", with an anchoring efficiency as high as 80%. Additionally, glycine moieties on the nanoplatform ensure spatial extensibility by charge repulsion, enabling targeted antibiotic release around bacteria. This precise antibacterial effect increases the bactericidal activities of the nanoplatform against S. aureus or P. aeruginosa by 25% and 22% respectively, effectively eliminating the bacteria and dispersing the biofilms. Furthermore, 3,4-dihydropyrimidin-2(1H)-one (DHPM) moieties act as ROS scavengers that alleviate oxidative stress and inflammatory responses, promoting tissue repair progression into the proliferative phase characterized by increased extracellular matrix deposition, angiogenesis, and granulation tissue formation, ultimately accelerating diabetic wound healing. Overall, this work presents an innovative bacterial response strategy for achieving in situ antibacterial and antioxidant effects in infected tissues and provides a promising therapeutic approach for treating infected diabetic wounds. STATEMENT OF SIGNIFICANCE: : Infected diabetic wound management remains a major world health issue. Severe bacterial infection leads to excessive oxidative stress and persistent inflammatory response, which seriously hinders the wound healing process. As a protective barrier for bacteria, biofilms are a key obstacle to effective bacterial clearance. This study provides a bacteria-responsive nanoplatform for the healing of infected diabetic wounds. The nanoplatform not only exhibits improved biofilm penetration but also actively anchors the enclosed bacteria and enables targeted antibiotic release to disperse the biofilm. The DHPM moieties of the nanoplatform act as ROS scavengers which could alleviate inflammatory responses, promote tissue repair progression into the proliferative phase, and ultimately accelerate diabetic wound repair.},
}

@article {pmid39710209,
year = {2024},
author = {Xu, M and Yu, S and Li, P and Chen, Y and Chen, Y and Pan, J and Deng, X and Hu, H},
title = {Tailored multilayer nanoparticles against resistant P. aeruginosa by disrupting the thickened mucus, dense biofilm and hyperinflammation.},
journal = {Journal of controlled release : official journal of the Controlled Release Society},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jconrel.2024.12.040},
pmid = {39710209},
issn = {1873-4995},
abstract = {Therapeutic challenges of chronic pulmonary infections caused by multidrug-resistant Pseudomonas aeruginosa (MDRP. aeruginosa) biofilms due to significantly enhanced antibiotic resistance. This resistance is driven by reduced outer membrane permeability, biofilm barriers, and excessive secretion of virulence factors. Thickened mucus in the airways exacerbates the problem by impeding antibiotic penetration, providing a breeding ground for biofilms, consequently aggravating infection. Moreover, biofilms recruit numerous immune cells, resulting in chronic inflammation and lung tissue damage. In turn, damaged airway further facilitates bacterial colonization and elevated mucus production. To thoroughly disintegrate the stubborn triad of "thickened mucus & dense biofilm & excessive inflammation" and address drug resistance, tailored multilayer nanoparticles (NPVC/PBIP NPs) were developed. NPVC/PBIP NPs were engineered through self-assembly of vanillin-chitosan amphiphilic polymer loading polymyxin B-linoleic acid ion pairs in. Then polyaspartic acid and N-acetylcysteine-ε-poly-l-lysine were coated by layer-by-layer on the surface of vanillin-chitosan NPs via electrostatic interactions. As expected, the NAC units on NPVC/PBIP NPs effectively thinned human clinical sputum and porcine sputum, resulting in rapid sputum penetration followed by biofilm permeation. NPVC/PBIP NPs achieved over 99 % eradication of mature biofilms in vitro. Furthermore, they effectively inhibited virulence factors production and bacteria re-adhesion (biofilm reformation) while exhibiting superior anti-inflammatory and antioxidant activities. In a chronic pulmonary infection model, NPVC/PBIP NPs remarkably thinned airway mucus, reduced bacterial burden by 99.7 %, alleviated inflammatory cell infiltration, and minimized lung tissue damage. In summary, the NPVC/PBIP NPs represent a novel and promising strategy to manage MDRP. aeruginosa biofilms associated infections by disintegrating the stubborn triad of "thickened mucus & dense biofilm & excessive inflammation".},
}

@article {pmid39708762,
year = {2024},
author = {Zhou, R and Huang, X and Ni, Y and Ma, Z and Wei, H and Jin, Q and Ding, Z},
title = {Physicochemical behavior and ecological risk of biofilm-mediated microplastics in aquatic environments.},
journal = {Aquatic toxicology (Amsterdam, Netherlands)},
volume = {279},
number = {},
pages = {107209},
doi = {10.1016/j.aquatox.2024.107209},
pmid = {39708762},
issn = {1879-1514},
abstract = {The prevalence of microplastics (MPs) in aquatic environments has become the core of environmental pollution. In recent years, the inevitable biological aging process of MPs in natural environments has attracted researchers' attention. Such biofilm-mediated MPs, colonized by microorganisms, affect the physicochemical behavior and potential ecological risks of MPs. Therefore, it is critical to understand the impact of MPs' biofilm formation on the environmental fate and toxicity of MPs. This review presented a comprehensive discussion of the impact of biofilm formation on unique carrier effects and toxicological effects of MPs in aquatic environments. First, the biofilm formation process on MPs, the compositions of microorganisms in biofilm and the factors influencing biofilm formation were briefly summarized. Second, the sorption of pollutants and enrichment of antibiotic resistance genes onto biofilm-mediated MPs were discussed. Third, the potential effects of biofilm-mediated MPs on gut microbiota were analyzed. Finally, gaps in the field that require further investigations were put forward. This review emphasized that biofilm-mediated MPs have higher environmental risks and ecotoxicity, which is helpful in providing new insights for pollution prevention and control of new pollutant MPs.},
}

@article {pmid39708744,
year = {2024},
author = {Gao, J and Ju, Z and Yang, Q and Zhou, X},
title = {Exploring different effects of biofilm formation and natural organic matter adsorption on the properties of three typical microplastics in the freshwater.},
journal = {The Science of the total environment},
volume = {958},
number = {},
pages = {178156},
doi = {10.1016/j.scitotenv.2024.178156},
pmid = {39708744},
issn = {1879-1026},
abstract = {Microplastics entering the aqueous environment are susceptible to the surrounding environmental processes, including biofilm formation and natural organic matter (NOM) adsorption, which significantly alters their properties and environmental fate. In this study, polyethylene (PE), polyvinyl chloride (PVC) and polyethylene terephthalate (PET) microplastics were respectively incubated in the untreated and disinfected freshwater to investigate the different effects of biofilm formation and only NOM adsorption on the properties of microplastics. The results showed that the total amount of fouling biomass driven by biofilm formation was markedly higher than that of NOM adsorption. The changes in microplastic surface morphologies and special surface area dominated by biofilm formation and NOM adsorption were different; biofilm formation induced various shaped bacteria and a dense layer of extracellular polymeric substances adhering on microplastic surfaces with the decreased special surface area, whereas NOM adsorption mainly resulted in the obvious pores, cracks and winkles and the increased special surface area, indicating the initial degradation of microplastics. Moreover, both biofilm formation and NOM adsorption could reduce the hydrophobicity of three microplastics. The decreased trends of the hydrophobicity of microplastics were closely related to the amount of fouling biomass in a linear relationship with different influenced coefficients (slope a), subsequently verifying that NOM adsorption played a key role in the alternation of the hydrophobicity of microplastics. Surface chemical characterization by FTIR and 3D-EEMs presented the generation of additional functional groups and components on the microplastic surface attributed to the biofilm formation and NOM adsorption in different extent and sequence. This study provides more detailed information about the different effects of biofilm formation and NOM adsorption on the properties of microplastics in the aqueous environment.},
}

@article {pmid39708620,
year = {2024},
author = {Wang, L and Zhang, C and Liu, Y and Qiu, Y and Wanyan, D and Liu, J and Cheng, G and Lin, P and Huang, X},
title = {Achieving mainstream nitrogen removal by partial nitrification and anammox in the carriers-coupled membrane aerated biofilm reactor.},
journal = {Water research},
volume = {271},
number = {},
pages = {123000},
doi = {10.1016/j.watres.2024.123000},
pmid = {39708620},
issn = {1879-2448},
abstract = {The integration of partial nitrification-anammox (PN/A) into membrane-aerated biofilm reactor (MABR) is a promisingly energy-efficient and high-efficiency technology for nitrogen removal. The inhibition of nitrite oxidizing bacteria (NOB) remains as the most significant challenge for its development. In our investigation, we proposed a novel process to integrate carriers to MABR (CMABR), which combined the carriers enriched with anaerobic ammonium-oxidizing bacteria (AnAOB) and partial nitrifying MABR system. The effect of different hydraulic retention time (HRT) was explored in CMABR and it showed that the nitrogen removal rate of CMABR could reach more than 200 g-N/(m[3]·d) at an HRT of 3 h The increase of NOB activity was witnessed when the residual NH4[+]-N concentration was lower than 5 mg-N/L. Finally, the higher nitrogen removal rate and successful PN/A can be achieved by optimized condition through the operation of two-stage CMABRs with 30 % of carriers filling ratio and a total HRT of 6 h Superior NH4[+]-N removal efficiency (97 %) and total nitrogen removal efficiency (81 %) were reached compared with other MABR for PN/A processes. The CMABR exerted the special advantage that significant AnAOB attached on the carriers, rather than only on the membrane biofilm, thus it was beneficial to maintain the activity of ammonia oxidizing bacteria (AOB) and improve the nitrogen removal rate and effluent quality. This investigation provides creative and significant perspectives for the design and operation of PN/A processes in the future MABR applications.},
}

@article {pmid39708379,
year = {2024},
author = {Kaksonen, AH and Wylie, J and Morgan, MJ and Walsh, T and Tjandraatmadja, G and Barry, K and Gonzalez, D and Goodman, N and Vanderzalm, J and Dillon, P and Sidhu, J and Puzon, GJ},
title = {Impact of stormwater on biofilm density and microbial community composition in water distribution networks.},
journal = {Water research},
volume = {272},
number = {},
pages = {122989},
doi = {10.1016/j.watres.2024.122989},
pmid = {39708379},
issn = {1879-2448},
abstract = {Harvesting of stormwater and injecting it into aquifers for storage and recovery during high water demand periods is a promising technology for augmenting conventional water reserves. However, little has been known on how stormwater impacts the biofouling of water distribution infrastructure. This study evaluated the effect on harvested and limestone aquifer treated stormwater on biofilm formation in a pilot distribution pipe network compared to an identical drinking water pipe rig. Coupons made of cement, copper and polyvinyl chloride (PVC) pipe materials were installed to each pipe rig and exposed to stormwater or drinking water. The total cell counts determined by flow cytometry on the pilot rig coupons were in the order of 10[5] to 10[7] cells/cm[2] for both source waters and showed some variation over the duration of the study. The culturable cell counts were somewhat higher for stormwater exposed coupons than for coupons in mains water rig. The total number of thermotolerant coliforms was notably higher on coupons exposed to stormwater than on those exposed to mains water. Considerable differences were observed in the bacterial and eukaryotic communities on coupons made of various materials and exposed to mains water and stormwater using pyrosequencing. Moreover, seasonal variations were observed in community composition and diversity. A number of bacterial and eukaryotic families and genera harbouring potential human pathogens were detected in both mains water and stormwater systems, with larger numbers of genera observed in the latter indicating a potentially increased risk of exposure to pathogens with stormwater. The stormwater system also harboured sulfur reducers, and a greater diversity of iron oxidisers. A number of bacterial genera that contribute to nitrogen cycling were observed in both mains water and stormwater systems. A number of bacteria grazing eukaryotes were detected, indicating that the biofilm communities are quite dynamic and the abundance of bacteria is able to support higher level eukaryotes.},
}

@article {pmid39707959,
year = {2024},
author = {},
title = {Correction to: Poly-Ether-Ether-Ketone versus dead-soft coaxial bonded retainers: a randomized clinical trial. Part 2: periodontal health and microbial biofilm assessment.},
journal = {European journal of orthodontics},
volume = {47},
number = {1},
pages = {},
doi = {10.1093/ejo/cjae080},
pmid = {39707959},
issn = {1460-2210},
}

@article {pmid39707459,
year = {2024},
author = {Del Rey, YC and Kitzinger, K and Lund, MB and Schramm, A and Meyer, RL and Wagner, M and Schlafer, S},
title = {pH-FISH: coupled microscale analysis of microbial identity and acid-base metabolism in complex biofilm samples.},
journal = {Microbiome},
volume = {12},
number = {1},
pages = {266},
pmid = {39707459},
issn = {2049-2618},
support = {doi.org.1055776/COE7//Austrian Science Fund (FWF) for the Cluster of Excellence "Microbiomes drive Planetary Health"/ ; doi.org.1055776/COE7//Austrian Science Fund (FWF) for the Cluster of Excellence "Microbiomes drive Planetary Health"/ ; },
mesh = {*Biofilms/growth & development ; *In Situ Hybridization, Fluorescence/methods ; Hydrogen-Ion Concentration ; Humans ; *Streptococcus/metabolism/genetics ; Veillonella/metabolism ; Dental Caries/microbiology ; Microbiota ; Bacteria/metabolism/classification/genetics ; },
abstract = {BACKGROUND: Correlative structural and chemical imaging of biofilms allows for the combined analysis of microbial identity and metabolism at the microscale. Here, we developed pH-FISH, a method that combines pH ratiometry with fluorescence in situ hybridization (FISH) in structurally intact biofilms for the coupled investigation of microbial acid metabolism and biofilm composition. Careful biofilm handling and modified sample preparation procedures for FISH allowed preservation of the three-dimensional biofilm structure throughout all processing and imaging steps. We then employed pH-FISH to investigate the relationship between local biofilm pH and the distribution of acid-producing (streptococci) and acid-consuming (Veillonella spp.) bacteria in dental biofilms from healthy subjects and caries-active patients.

RESULTS: The relative abundance of streptococci correlated with low biofilm pH at the field-of-view level, while the opposite trend was observed for Veillonella spp. These results suggest that clusters of streptococci contribute to the formation of acidic pockets inside dental biofilms, whereas Veillonella spp. may have a protective role against biofilm acidification.

CONCLUSIONS: pH-FISH combines microscale mapping of biofilm pH in real time with structural imaging of the local microbial architecture, and is a powerful method to explore the interplay between biofilm composition and metabolism in complex biological systems. Video Abstract.},
}

*Biofilms/growth & development
*In Situ Hybridization, Fluorescence/methods
Hydrogen-Ion Concentration
Humans
*Streptococcus/metabolism/genetics
Veillonella/metabolism
Dental Caries/microbiology
Microbiota
Bacteria/metabolism/classification/genetics

@article {pmid39706307,
year = {2024},
author = {Zhang, B and Liu, J and Cai, C and Zhou, Y},
title = {Membrane photobioreactor for biogas capture and conversion - Enhanced microbial interaction in biofilm.},
journal = {Bioresource technology},
volume = {418},
number = {},
pages = {131999},
doi = {10.1016/j.biortech.2024.131999},
pmid = {39706307},
issn = {1873-2976},
abstract = {The urgency to mitigate greenhouse gas emissions has driven interest in sustainable biogas utilization. This study investigates a 1 L enclosed membrane photobioreactor (MPBR) using a microalgae-methanotroph coculture for biogas capture. Operating with a hydraulic and solid retention time of 7 days and a biogas loading rate of 2.7 L /day, the introduction of gas membrane module increased CO2-C and CH4-C uptake rates by 12 % and 50 %, respectively. Biofilm formation on the membrane surface enhanced system performance, with imaging analyses revealing methanotroph predominantly located near the membrane surface and photosynthetic microorganisms distributed throughout. Metagenomic analysis showed shifts in key metabolic pathways, including increased abundance of soluble methane monooxygenase genes and enhanced vitamin B synthesis in the biofilm. These findings highlight the spatial organization and metabolic interactions in methanotroph-microalgae coculture system, providing insights into the role of membrane-induced biofilms in improving MPBR performance for sustainable biogas utilization.},
}

@article {pmid39706277,
year = {2024},
author = {Golan, N and Parizat, A and Tabachnikov, O and Barnea, E and Olsen, WP and Otzen, DE and Landau, M},
title = {Resilience and Charge-Dependent Fibrillation of functional amyloid: Interactions of Pseudomonas Biofilm-Associated FapB and FapC Amyloids.},
journal = {The Journal of biological chemistry},
volume = {},
number = {},
pages = {108096},
doi = {10.1016/j.jbc.2024.108096},
pmid = {39706277},
issn = {1083-351X},
abstract = {FapC and FapB are biofilm-associated amyloids involved in the virulence of Pseudomonas and other bacteria. We herein demonstrate their exceptional thermal and chemical resilience, suggesting that their biofilm structures might withstand standard sterilization, thereby contributing to the persistence of P. aeruginosa infections. Our findings also underscore the impact of environmental factors on Fap proteins, suggesting that orthologs in different Pseudomonas strains adapt to specific environments and roles. Challenging previous assumptions about a simple nucleation role for FapB in promoting FapC aggregation, the study shows a significant influence of FapC on FapB aggregation. The interaction between these FapB and FapC is intricate: FapB stabilizes FapC fibrils, while FapC slows down FapB fibrillation but can still serve as a cross-seeding template. This complex interplay is key to understanding their roles in bacterial biofilms. Furthermore, the study highlights distinct differences between Fap and E. coli's CsgA (curli) amyloid, where CsgB assumes a simple unidirectional role in nucleating CsgA fibrillation, emphasizing the importance of a comprehensive understanding of various amyloid systems. This knowledge is vital for developing effective intervention strategies against bacterial infections and leveraging the unique properties of these amyloids in technological applications such as novel bio-nanomaterials or protective coatings.},
}

@article {pmid39705953,
year = {2024},
author = {Sun, H and Ju, X and Wang, H and Ma, X and Shi, B},
title = {Ammonia nitrogen affects bacterial virulence and conditional pathogenic bacterial growth by regulating biofilm microbial metabolism and EPS secretion in laboratory scale distribution systems.},
journal = {The Science of the total environment},
volume = {958},
number = {},
pages = {178150},
doi = {10.1016/j.scitotenv.2024.178150},
pmid = {39705953},
issn = {1879-1026},
abstract = {The control of conditional pathogenic bacteria and inhibition of their virulence factors (VFs) in drinking water distribution systems (DWDSs) is vital for drinking water safety. This study adopted two groups of DWDSs to investigate how ammonia nitrogen affects bacterial VFs and conditional pathogenic bacterial growth in biofilms. Our results indicated that Acidimicrobium (95,916.62 ± 119.24 TPM), Limnohabitans (30,338.81 ± 139.14 TPM), and Sediminibacterium (10,658.01 ± 48.94 TPM) were predominant in the biofilm bacterial community of DWDSs with NH3-N addition. Under these conditions, the abundances of various bacterial metabolites, such as L-glutamate (1.45-fold), 2-oxoglutarate (1.24-fold), pyruvate (2.10-fold), and adenosine monophosphate (AMP, 5.29-fold), were significantly upregulated, which suggested the upregulation of amino acid, carbohydrate, nucleotide, lipid, pyrimidine and purine metabolism. These metabolic pathways accelerated extracellular polymeric substance (EPS) secretion. The protein concentration in EPS also increased to 187.59 ± 0.58 μg/cm[2]. The increased EPS secretion promoted the amide I CO group of the EPS protein to interact with the surface of the DWDSs, thus enhancing the ability of bacteria (especially conditional pathogenic bacteria) to adhere to the pipe surface to form biofilms. Due to EPS protection, the abundance of the adherence subtype of VFs and the plate counts of Pseudomonas aeruginosa increased to 5912.8 ± 21.89 TPM and 655.78 ± 27.10 CFU/cm[2], respectively. Therefore, NH3-N in DWDSs increased bacterial VFs levels and promoted the growth of some conditional pathogenic bacteria by regulating biofilm microbial metabolic pathways and EPS secretion, ultimately impacting the interaction between EPS and the pipe surface.},
}

@article {pmid39705926,
year = {2024},
author = {Nabawy, A and Chattopadhyay, AN and Makabenta, JMV and Hassan, MA and Yang, J and Park, J and Jiang, M and Jeon, T and Im, J and Rotello, VM},
title = {Cationic conjugated polymers with tunable hydrophobicity for efficient treatment of multidrug-resistant wound biofilm infections.},
journal = {Biomaterials},
volume = {316},
number = {},
pages = {123015},
doi = {10.1016/j.biomaterials.2024.123015},
pmid = {39705926},
issn = {1878-5905},
abstract = {Biofilm-associated infections arising from antibiotic-resistant bacteria pose a critical challenge to global health. We report the generation of a library of cationic conjugated poly(phenylene ethynylene) (PPE) polymers featuring trimethylammonium terminated sidechains with tunable hydrophobicity. Screening of the library identified an amphiphilic polymer with a C11 hydrophobic spacer as the polymer with the highest antimicrobial efficacy against biofilms in the dark with excellent selectivity. These polymers are highly fluorescent, allowing label-free monitoring of polymer-bacteria/biofilm interactions. The amphiphilic conjugated polymer penetrated the biofilm matrix in vitro and eradicated resident bacteria through membrane disruption. This C11 polymer was likewise effective in an in vivo murine model of antibiotic-resistant wound biofilm infections, clearing >99.9 % of biofilm colonies and efficient alleviation of biofilm-associated inflammation. The results demonstrate the therapeutic potential of the fluorescent conjugated polymer platform as a multi-modal antimicrobial and imaging tool, surpassing conventional antimicrobial strategies against resilient biofilm infection.},
}

@article {pmid39705888,
year = {2024},
author = {Pant, K and Palmer, J and Flint, S},
title = {Evaluation of single and multispecies biofilm formed in the static and continuous systems.},
journal = {International journal of food microbiology},
volume = {429},
number = {},
pages = {111030},
doi = {10.1016/j.ijfoodmicro.2024.111030},
pmid = {39705888},
issn = {1879-3460},
abstract = {Biofilms consisting of multiple species of bacteria compared to biofilms of single species are common in natural environments including food contact surfaces. The objective of this study was to understand the biofilm formation and the efficiency of sodium hypochlorite (50 ppm/5 mins) on the single and multiple species biofilm of Pseudomonas fluorescens, Staphylococcus aureus, and Listeria monocytogenes formed on stainless steel surfaces in static and continuous systems. The cell concentration of Listeria in the dual and triple species biofilm in the continuous system (7.3-8.4 log CFU/cm[2]) was higher compared to the static system (4.7-4.9 log CFU/cm[2]) while the concentration remained consistent in the single species biofilm (6.4-6.7 log CFU/cm[2]) for both systems. Biofilm formed in the static system was significantly (p < 0.001) more susceptible to sodium hypochlorite than biofilm formed in the continuous system. This observation agrees with the exopolysaccharide concentration which was found to be higher in the continuous system (8.0-15.6 μg/cm[2]) than in the static system (3.2-6.3 μg/cm[2]) indicating a positive correlation between EPS production and sanitizer resistance. Epifluorescence microscopy images showed the formation of interstitial voids within the three-species biofilm and filaments in the single and dual species Listeria biofilms in the continuous system which were absent in the static system. Overall, results showed that the biofilm formation and sanitizer resistance vary due to multispecies interaction and the presence of flow and should be considered an important variable in multispecies sanitizer resistance studies.},
}

@article {pmid39705014,
year = {2024},
author = {Aftab, H and Samudio, J and Wang, G and Le, L and Soni, RK and Donegan, RK},
title = {Heme alters biofilm formation in Mycobacterium abscessus.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0241524},
doi = {10.1128/spectrum.02415-24},
pmid = {39705014},
issn = {2165-0497},
abstract = {Mycobacterium abscessus (Mabs) is commonly found in the cystic fibrosis (CF) lung. During infection, Mabs can form biofilms in the lung which reduce both the ability of the immune response to clear infection and the effectiveness of antibiotic therapy. In the CF lung, heme and hemoglobin levels are increased and may provide both iron and heme to Mabs cells. In this work, we show that exogenous heme altered Mabs biofilm formation and measured the effects of exogenous heme on protein level and metabolism in Mabs. Our findings suggest that heme impacts iron homeostasis in Mabs and affects other aspects of its metabolism, highlighting the potential role of heme as a critical nutrient for Mabs growth and biofilm formation.IMPORTANCEMycobacterium abscessus (Mabs) is commonly found in the cystic fibrosis (CF) lung, where Mabs can form biofilms that can reduce the efficacy of antibiotics. During infection, the CF lung can have more than 10 times the extracellular heme than that of a healthy lung. We have found that extracellular heme can change the way Mabs cells grow and form biofilms, which may have implications for pathogenesis.},
}

@article {pmid39704863,
year = {2024},
author = {Cui, L and Chen, S and Cao, X and Zhang, X and Huang, X and Shibata, T and Yang, Y and Shi, L and Zhao, C and Wang, S and Yang, S},
title = {Simultaneous removal of heavy metals and inorganic nitrogen by using the biofilm of Marichromatium gracile YL28.},
journal = {World journal of microbiology & biotechnology},
volume = {41},
number = {1},
pages = {14},
pmid = {39704863},
issn = {1573-0972},
support = {201505026//National Marine Public Industry Research/ ; 2018J0149//Natural Science Foundation of Fujian Province/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Metals, Heavy/metabolism ; *Nitrogen/metabolism ; *Biodegradation, Environmental ; *Water Pollutants, Chemical/metabolism ; Adsorption ; Chromatiaceae/metabolism ; Extracellular Polymeric Substance Matrix/metabolism/chemistry ; },
abstract = {Heavy metal and nitrogen contaminations are serious concerns in aquatic environments. Marichromatium gracile YL28, a marine purple sulfur bacterium, has shown great potential as a bioremediation agent for removing inorganic nitrogen from marine water. This study further investigated its ability to simultaneously absorb heavy metals, including Pb(II), Cu(II), Cd(II) and Cr(VI), and remove inorganic nitrogen. The contributions of photopigment and extracellular polymeric substances (EPS) in the YL28 biofilm to heavy metal adsorption and tolerance were also evaluated. The YL28 biofilm demonstrated higher adsorption efficiencies for heavy metal ions than planktonic cells. A high level of EPS was detected in the biofilm. The effects of four heavy metal on the inhibition of photopigment synthesis showed that high concentrations of Cu(II) greatly inhibited the production of BChl a and Car. The adsorption efficiencies of Pb(II), Cu(II), Cd(II), and Cr(VI) in the YL28 biofilm reactor reached 86.59%, 72.94%, 80.06%, and 95.95%, respectively. Elevated concentrations of heavy metal ions only marginally impeded ammonia nitrogen removal; they impacted neither nitrite and nitrate removals nor hindered the simultaneous elimination of three inorganic nitrogen compounds. Coupled with their ability to remove inorganic nitrogen, the high adsorption capacity and tolerance of YL28 biofilms toward heavy metal suggest a promising solution for mitigating metal pollutants.},
}

*Biofilms/drug effects/growth & development
*Metals, Heavy/metabolism
*Nitrogen/metabolism
*Biodegradation, Environmental
*Water Pollutants, Chemical/metabolism
Adsorption
Chromatiaceae/metabolism
Extracellular Polymeric Substance Matrix/metabolism/chemistry

@article {pmid39704631,
year = {2024},
author = {Sinha, A and Taneja, S and Shetty, DC and Bhalla, VK},
title = {Efficacy of Antimicrobial Peptide GH12 on a Multispecies Endodontic Biofilm Model: An In-vitro Study.},
journal = {European endodontic journal},
volume = {9},
number = {4},
pages = {411-417},
doi = {10.14744/eej.2024.75983},
pmid = {39704631},
issn = {2548-0839},
mesh = {*Biofilms/drug effects ; *Porphyromonas gingivalis/drug effects ; Humans ; *Enterococcus faecalis/drug effects ; *Microbial Sensitivity Tests/methods ; *Fusobacterium nucleatum/drug effects ; Streptococcus mutans/drug effects ; In Vitro Techniques ; Microscopy, Electron, Scanning/methods ; Antimicrobial Peptides/pharmacology ; Dental Pulp Cavity/microbiology ; },
abstract = {OBJECTIVE: This study aimed to evaluate the antibacterial efficacy of different concentrations of GH12 on a simulated multispecies biofilm comprising Enterococcus faecalis, Streptococcus mutans, Fusobacterium nucleatum and Porphyromonas gingivalis.

METHODS: Single rooted teeth were decoronated, cut into 1.5 mm sections to obtain dentine discs which were randomly allocated into five groups: (n=12 each), Group 1: Phosphate Buffered Solution (PBS) - negative control, Group II: 5% Sodium hypochlorite (NaOCl) - positive control, Group III: Minimum Inhibitory Concentration (MIC) of GH12, Group IV: 2x MIC of GH12, Group V: 4x MIC of GH12. Colony forming units, Crystal violet assay and scanning electron microscopy examinations were performed. One-way ANOVA and Turkey's test were applied for statistical analysis using the SPSS software version 22.0.

RESULTS: Group II (NaOCl) showed maximum reduction in bacterial load followed by Group V (GH12 16mg/mL) with no statistically significant difference (p=1.000). On comparing the mean CFU reduction, the maximum reduction was identified for S. mutans and the least was for P. gingivalis. There was marked erosion observed in the NaOCl group whereas the GH12 group showed no erosive changes in the morphology and no bacterial colonies was identified.

CONCLUSION: The findings revealed that GH12 at higher concentrations inhibits and disrupts the growth of multispecies endodontic biofilm comparable to NaOCl but without erosive effects to the dentine, further highlighting its potential to be used as an antimicrobial solution. (EEJ-2023-10-147).},
}

*Biofilms/drug effects
*Porphyromonas gingivalis/drug effects
Humans
*Enterococcus faecalis/drug effects
*Microbial Sensitivity Tests/methods
*Fusobacterium nucleatum/drug effects
Streptococcus mutans/drug effects
In Vitro Techniques
Microscopy, Electron, Scanning/methods
Antimicrobial Peptides/pharmacology
Dental Pulp Cavity/microbiology

@article {pmid39703182,
year = {2024},
author = {Kaur, N and De, M},
title = {Shape and Size Dependent Antimicrobial and Anti-biofilm Properties of Functionalized MoS2.},
journal = {ACS infectious diseases},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsinfecdis.4c00860},
pmid = {39703182},
issn = {2373-8227},
abstract = {Bacterial resistance, accelerated by the misuse of antibiotics, remains a critical concern for public health, promoting an ongoing exploration for cost-effective and safe antibacterial agents. Recently, there has been significant focus on various nanomaterials for the development of alternative antibiotics. Among these, molybdenum disulfide (MoS2) has gained attention due to its unique chemical, physical, and electronic properties, as well as its semiconducting nature, biocompatibility, and colloidal stability, positioning it as a promising candidate for biomedical research. The impact of the shape and size of MoS2 nanomaterials on the antibacterial activity remains largely unexplored. In this study, we investigated the effect of the shape and size of MoS2 nanomaterials, such as quantum dots, nanoflowers, and nanosheets, on antimicrobial and anti-biofilm activity. As we had established earlier, functionalization with positively charged thiol ligands can enhance colloidal stability, biocompatibility, and antibacterial efficacy; we functionalized all targeted nanomaterials. Our results revealed that functionalized MoS2 quantum dots (F-MQDs) exhibited superior activity compared to functionalized MoS2 nanoflowers (F-MNFs) and functionalized MoS2 nanosheets (F-MNSs) against Staphylococcus aureus (SA), both drug-resistant (methicillin) and nonresistant strains. We observed very low minimum inhibitory concentration (MIC, 30 ng/mL) for F-MQDs. The observed trend in antibacterial efficacy was as follows: F-MQDs > F-MNFs ≥ F-MNSs. We explored the relevant mechanism related to the antibacterial activity where the balance between membrane depolarization and internalization plays the determining role. Furthermore, F-MQDs show enhanced anti-biofilm activity compared to F-MNFs and F-MNSs against mature MRSA biofilms. Due to the superior antibacterial and anti-biofilm activity of F-MQDs, we extended their application to wound healing. This study will help us to develop other appropriate surface modified nanomaterials for antibacterial and anti-biofilm activity for further applications such as antibacterial coatings, water disinfection, and wound healing.},
}

@article {pmid39702763,
year = {2024},
author = {Beckman, RL and Cella, E and Azarian, T and Rendueles, O and Fleeman, RM},
title = {Diverse polysaccharide production and biofilm formation abilities of clinical Klebsiella pneumoniae.},
journal = {NPJ biofilms and microbiomes},
volume = {10},
number = {1},
pages = {151},
pmid = {39702763},
issn = {2055-5008},
support = {R00AI163295//Division of Intramural Research, National Institute of Allergy and Infectious Diseases (Division of Intramural Research of the NIAID)/ ; ANR 22 CE20 00181 BETinCAP//Agence Nationale de la Recherche (French National Research Agency)/ ; },
mesh = {*Biofilms/growth & development ; *Klebsiella pneumoniae/genetics/growth & development/physiology ; Humans ; *Polysaccharides, Bacterial/metabolism/biosynthesis/genetics ; *Klebsiella Infections/microbiology ; Phenotype ; Virulence ; Gene Expression Regulation, Bacterial ; Genotype ; Drug Resistance, Multiple, Bacterial/genetics ; },
abstract = {Klebsiella pneumoniae infections have become a growing threat for human health. The lack of understanding of the relationship between antibiotic resistance, mucoviscosity, and biofilm formation impedes our abilities to effectively predict K. pneumoniae infection outcomes. The Multidrug-Resistant Organism Repository and Surveillance Network offers a unique opportunity into the genetic and phenotypic variabilities in the K. pneumoniae isolates. To this end, we compared the genetic profiles of these isolates with the phenotypic biofilm formation, percent mucoviscosity, and growth rates. There was a significant phenotype-genotype correlation with decreased biofilm formation and an insertion sequence in the transcriptional activator of the type III fimbrial system. Interestingly, the most mucoid strains in the populations were lacking the genetic element regulating the mucoid phenotype and three of these isolates were able to form robust biofilms. The combination of phenotypic, genomic, and image analyses revealed an intricate relation between growth, mucoviscosity and specific virulence-associated genetic determinants.},
}

*Biofilms/growth & development
*Klebsiella pneumoniae/genetics/growth & development/physiology
Humans
*Polysaccharides, Bacterial/metabolism/biosynthesis/genetics
*Klebsiella Infections/microbiology
Phenotype
Virulence
Gene Expression Regulation, Bacterial
Genotype
Drug Resistance, Multiple, Bacterial/genetics

@article {pmid39701350,
year = {2024},
author = {Sheng, M and Liu, J and Zhou, Y and Shao, S},
title = {Effect of metal ions on moving bed biofilm reactor (MBBR) for nitrogen removal in wastewater: Performance characteristics, flocculation efficiency and bacterial community.},
journal = {Environmental research},
volume = {267},
number = {},
pages = {120655},
doi = {10.1016/j.envres.2024.120655},
pmid = {39701350},
issn = {1096-0953},
abstract = {Advanced operational moving bed biofilm reactor (MBBR) has demonstrated to achieve simultaneous sludge yield minimization and pollutants removal. However, effect of different metal ions on MBBR performance for nutrients removal in wastewater under low carbon to nitrogen ratio is still unclear. Fate of NH4[+]-N and NO3[-]-N by MBBR were explored under the influence of Mn(II), Cu(II), and Fe(II) at carbon to nitrogen ratio of 5. The result showed that Mn(II) and Fe(II) significantly improved the NH4[+]-N and TN removal with a removal ratio of 71.0% and 80.5%, and 77.8% and 87.5% compared to the absence of added metal ions, and Cu(II) reduced the nitrogen removal. Biofilm characteristics including extracellular polymeric substances (EPS), electron transport system activity, and reactive oxygen species were investigated. The result indicated that both Mn(II) and Fe(II) enhanced the extracellular polymeric substances activity, electron transfer, and flocculation efficiency and hydrophilicity of biofilm. Furthermore, nitrification and denitrification processes of MBBR were further evaluated by X-ray photoelectron spectroscopy, fourier transform infrared reflection, cyclic voltammetry, differential pulse voltammetry, and Tafel curves. The result revealed that the main functional groups (e.g., C=O, C-O, and O-C=O bonds), and manganese and iron cycling might be involved in the nitrogen and metal ions removal. Finally, microbial community and co-occurrence network of biofilm were studied, showing that Proteobacteria and Bacteroidetes were identified as the dominant phyla for nitrogen and metal ions removal. This study aimed to provide the technical support for the startup and engineering applications of MBBR in wastewater treatment.},
}

@article {pmid39700628,
year = {2024},
author = {Voglauer, EM and Alteio, LV and Pracser, N and Thalguter, S and Quijada, NM and Wagner, M and Rychli, K},
title = {Listeria monocytogenes colonises established multispecies biofilms and resides within them without altering biofilm composition or gene expression.},
journal = {Microbiological research},
volume = {292},
number = {},
pages = {127997},
doi = {10.1016/j.micres.2024.127997},
pmid = {39700628},
issn = {1618-0623},
abstract = {Listeria (L.) monocytogenes can survive for extended periods in the food producing environment. Here, biofilms possibly provide a niche for long-term survival due to their protective nature against environmental fluctuations and disinfectants. This study examined the behaviour of a L. monocytogenes ST121 isolate in a multispecies biofilm composed of Pseudomonas (P.) fragi, Brochothrix (B.) thermosphacta, and Carnobacterium (C.) maltaromaticum, previously isolated from a meat processing facility. The composition of the biofilm community and matrix, and transcriptional activity were analysed. L. monocytogenes colonised the multispecies biofilm, accounting for 6.4 % of all total biofilm cells after six hours. Transcriptomic analysis revealed 127 significantly up-regulated L. monocytogenes genes compared to the inoculum, including motility, chemotaxis, iron, and protein transport related genes. When comparing the differentially expressed transcripts within the multispecies biofilm with and without L. monocytogenes, only a cadmium/zinc exporting ATPase gene in C. maltaromaticum was significantly upregulated, while the other 9313 genes in the biofilm community showed no significant differential expression. We further monitored biofilm development over time (6, 24 hours and 7 days). P. fragi remained the dominant species, while L. monocytogenes was able to survive in the multispecies biofilm accounting for 2.4 % of total biofilm cells after 7 days, without any significant changes in its abundance. The presence of L. monocytogenes did neither alter the biofilm community nor its matrix composition (amount of extracellular DNA, carbohydrates, and protein). Our data indicate that L. monocytogenes resides in multispecies biofilms, potentially increasing survival against cleaning and disinfection in food processing environments, supporting persistence.},
}

@article {pmid39697559,
year = {2024},
author = {},
title = {Functional Study of desKR: A Lineage-Specific Two-Component System Positively Regulating Staphylococcus Aureus Biofilm Formation [Retraction].},
journal = {Infection and drug resistance},
volume = {17},
number = {},
pages = {5579-5580},
doi = {10.2147/IDR.S509159},
pmid = {39697559},
issn = {1178-6973},
abstract = {[This retracts the article DOI: 10.2147/IDR.S485049.].},
}

@article {pmid39696637,
year = {2024},
author = {Zarenezhad, E and Behmard, E and Karami, R and Behrouz, S and Marzi, M and Ghasemian, A and Soltani Rad, MN},
title = {The antibacterial and anti-biofilm effects of novel synthetized nitroimidazole compounds against methicillin-resistant Staphylococcus aureus and carbapenem-resistant Escherichia coli and Klebsiella pneumonia in vitro and in silico.},
journal = {BMC chemistry},
volume = {18},
number = {1},
pages = {244},
pmid = {39696637},
issn = {2661-801X},
abstract = {The antibiotic resistance and biofilm formation by bacterial pathogens has led to failure in infections elimination. This study aimed to assess the antibacterial and anti-biofilm properties of novel synthesized nitroimidazole compounds (8a-8o). In this study, nitroimidazole compounds were synthesized via the A3 coupling reaction of sample substrates in the presence of copper-doped silica cuprous sulfate (CDSCS). Fifteen and two carbapenemase producing Escherichia coli and Klebsiella pneumonia (CP-E. coli and CP-K. pneumonia, respectively) and one methicillin-resistant Staphylococcus aureus (MRSA) and one methicillin-susceptible S. aureus (MSSA) plus standard strain of each isolate were included. The antibacterial effects of these compounds demonstrated that the lowest minimum inhibitory and bactericidal concentrations (MIC/MBC, respectively) levels corresponded to compound 8g against S. aureus (1/2 µg/mL) and K. pneumonia (8/32 µg/mL) standard and clinical strains and confirmed by in silico assessment. This was comparable to those of metronidazole being 32-128 µg/mL against K. pneumonia and 32-64 µg/mL against S. aureus. In comparison to metronidazole, against CP-E. coli, compounds 8i and 8m had significantly higher antibacterial effects (p < 0.001) and against CP-K. pneumonia, compounds 8a-8j and 8l-8o had significantly higher (p < 0.0001) antibacterial effects. Compound 8g exhibited significantly higher antibacterial effects against MSSA and compounds 8b (p < 0.001), 8c (p < 0.001), 8d (p < 0.001), 8e (p < 0.001) and 8g (p < 0.0001) exerted significantly higher antibacterial effects than metronidazole against MRSA. Moreover, potential anti-biofilm effects was corresponded to compounds 8a, 8b, 8c, 8e, 8f, 8g, 8i, 8k, 8m and 8n. Considering the antibacterial and anti-biofilm effects of novel synthesized compounds evaluated in this study, further assessments is warranted to verify their properties in vivo and clinical trials in the future.},
}

@article {pmid39695832,
year = {2024},
author = {Portas, A and Carriot, N and Barry-Martinet, R and Ortalo-Magné, A and Hajjoul, H and Dormoy, B and Culioli, G and Quillien, N and Briand, JF},
title = {Shear stress controls prokaryotic and eukaryotic biofilm communities together with EPS and metabolomic expression in a semi-controlled coastal environment in the NW Mediterranean Sea.},
journal = {Environmental microbiome},
volume = {19},
number = {1},
pages = {109},
pmid = {39695832},
issn = {2524-6372},
abstract = {While waves, swells and currents are important drivers of the ocean, their specific influence on the biocolonization of marine surfaces has been little studied. The aim of this study was to determine how hydrodynamics influence the dynamics of microbial communities, metabolic production, macrofoulers and the associated vagile fauna. Using a field device simulating a shear stress gradient, a multi-scale characterization of attached communities (metabarcoding, LC-MS, biochemical tests, microscopy) was carried out for one month each season in Toulon Bay (northwestern Mediterranean). Shear stress appeared to be the primary factor influencing biomass, EPS production and community structure and composition. Especially, the transition from static to dynamic conditions, characterized by varying shear stress intensities, had a more pronounced effect on prokaryotic and eukaryotic beta-diversity than changes in shear stress intensity or seasonal physico-chemical parameters. In static samples, mobile microbe feeders such as arthropods and nematodes were predominant, whereas shear stress favored the colonization of sessile organisms and heterotrophic protists using the protective structure of biofilms for growth. The increase in shear stress resulted in a decrease in biomass but an overproduction of EPS, specifically exopolysaccharides, suggesting an adaptive response to withstand shear forces. Metabolite analysis highlighted the influence of shear stress on community dynamics. Specific metabolites associated with static conditions correlated positively with certain bacterial and algal groups, indirectly indicating reduced grazer control with increasing shear stress.},
}

@article {pmid39695822,
year = {2024},
author = {Abera, GB and Trømborg, E and Solli, L and Walter, JM and Wahid, R and Govasmark, E and Horn, SJ and Aryal, N and Feng, L},
title = {Biofilm application for anaerobic digestion: a systematic review and an industrial scale case.},
journal = {Biotechnology for biofuels and bioproducts},
volume = {17},
number = {1},
pages = {145},
pmid = {39695822},
issn = {2731-3654},
support = {336972//Norges Forskningsråd/ ; 257622//Norges Forskningsråd/ ; },
abstract = {Biofilm is a syntrophic community of microorganisms enveloped by extracellular polymeric substances and displays remarkable adaptability to dynamic environments. Implementing biofilm in anaerobic digestion has been widely investigated and applied as it promotes microbial retention time and enhances the efficiency. Previous studies on anaerobic biofilm primarily focused on application in wastewater treatment, while its role has been significantly extended to accelerate the degradation of lignocellulosic biomass, improve gas-liquid mass transfer for biogas upgrading, or enhance resistance to inhibitors or toxic pollutants. This work comprehensively reviewed the current applications of biofilm in anaerobic digestion and focused on impacting factors, optimization strategies, reactor set-up, and microbial communities. Moreover, a full-scale biofilm reactor case from Norway is also reported. This review provides a state of-the- art insight on the role of biofilm in anaerobic digestion.},
}

@article {pmid39695365,
year = {2024},
author = {Narimisa, N and Khoshbayan, A and Gharaghani, S and Razavi, S and Jazi, FM},
title = {Inhibitory effects of nafcillin and diosmin on biofilm formation by Salmonella Typhimurium.},
journal = {BMC microbiology},
volume = {24},
number = {1},
pages = {522},
pmid = {39695365},
issn = {1471-2180},
mesh = {*Biofilms/drug effects ; *Salmonella typhimurium/drug effects/physiology/genetics ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology ; *Nafcillin/pharmacology ; Microscopy, Electron, Scanning ; Bacterial Proteins/genetics/metabolism ; Gene Expression Regulation, Bacterial/drug effects ; },
abstract = {OBJECTIVE: The foodborne pathogen Salmonella enterica serovar Typhimurium causes self-limiting gastroenteritis in humans and is difficult to eliminate due to its ability to adhere to surfaces and form biofilms that exhibit high resistance to antimicrobial agents. To explore alternative strategies for biofilm treatment, it is essential to investigate novel agents that inhibit Salmonella biofilms.

METHOD: In this study, we investigated the minimum biofilm inhibitory concentrations (MBICs) and minimum biofilm eradication concentrations (MBECs) of nafcillin and diosmin, both previously identified as Lon protease inhibitors, against biofilms formed by S. Typhimurium. Furthermore, we examined the expression of genes associated with the type II toxin-antitoxin system to enhance our understanding of the impact of these inhibitors.

RESULTS: The findings indicated a strong antibiofilm effect of nafcillin, with MBIC and MBEC values of 8 µg/mL and 32 µg/mL, respectively. These results were confirmed by field emission scanning electron microscopy (FE-SEM), which showed that biofilm formation was reduced in the presence of nafcillin. Additionally, it revealed morphological changes in the bacteria within the nafcillin-treated biofilms. Furthermore, gene expression analyses demonstrated a significant reduction in the expression of type II TA system genes following treatment with nafcillin and diosmin.

CONCLUSION: This study highlights the effectiveness of nafcillin in disrupting the biofilms of S. Typhimurium. These results suggest promising avenues for the development of novel therapeutic strategies targeting biofilms associated with S. Typhimurium.},
}

*Biofilms/drug effects
*Salmonella typhimurium/drug effects/physiology/genetics
*Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology
*Nafcillin/pharmacology
Microscopy, Electron, Scanning
Bacterial Proteins/genetics/metabolism
Gene Expression Regulation, Bacterial/drug effects

@article {pmid39691803,
year = {2024},
author = {Sanesi, L and Puca, V and Caponio, VCA and Pinti, M and Balice, G and Femminella, B and Paolantonio, M and Cela, I and Kaushik, NK and Choi, EH and Grande, R and Sardella, E and Perrotti, V},
title = {Disinfection of dental root canals by cold atmospheric plasma: a systematic review and meta-analysis of dental biofilm.},
journal = {Frontiers in oral health},
volume = {5},
number = {},
pages = {1483078},
doi = {10.3389/froh.2024.1483078},
pmid = {39691803},
issn = {2673-4842},
abstract = {AIM: The intricate structure of the tooth root canals has a role in the colonization and biofilm formation in hidden areas that are hardly reached by standard endodontic treatments. This review aims at summarizing data from in vitro and ex vivo studies for a better understanding of the application of cold atmospheric plasma (CAP) for the disinfection of dental root canals.

METHODS: PubMed, Scopus, and Web of Science databases were screened. Characteristics of the included studies were extracted, and a meta-analysis on ex vivo studies was carried out to evaluate the effect of CAP on colony forming unit assay of Enterococcus faecalis (E. faecalis). The study was performed following the PRISMA 2020 guidelines.

RESULTS: A total of 31 studies fulfilled the selection criteria. Only 2 investigations reported an indirect plasma treatment, 28 trials used direct CAP administration, while 1 study applied both methods. Most of the studies were conducted on E. faecalis using as carrier gas Helium or Argon alone or in combination with Oxygen as well air. A considerable heterogeneity among studies was found regarding treatments which varied for source type, settings, and protocols of application. Despite this, CAP showed effectiveness in reducing E. faecalis colony forming unit with a standardized mean difference of 4.51, 95% C.I. = 2.55-6.48, p-value < 0.001.

CONCLUSION: The data demonstrated the antimicrobial effect of direct CAP application against microorganisms. In-vitro studies showed an effect that depended on the time and distance of treatment, while the meta-analysis performed on ex vivo studies showed that the effect of CAP was independent of time and distance.

https://doi.org/10.17605/OSF.IO/BJ59V, identifier OSF registries.},
}

@article {pmid39690480,
year = {2025},
author = {Sun, H and Jiang, L and Chen, J and Kang, C and Yan, J and Ma, S and Zhao, M and Guo, H and Yang, B},
title = {Genomic island-encoded LmiA regulates acid resistance and biofilm formation in enterohemorrhagic Escherichia coli O157:H7.},
journal = {Gut microbes},
volume = {17},
number = {1},
pages = {2443107},
pmid = {39690480},
issn = {1949-0984},
mesh = {*Escherichia coli O157/genetics/physiology/drug effects ; *Biofilms/growth & development/drug effects ; *Genomic Islands ; *Escherichia coli Proteins/genetics/metabolism ; *Gene Expression Regulation, Bacterial ; *Acids/pharmacology/metabolism ; Escherichia coli Infections/microbiology ; Humans ; Glutamate Decarboxylase ; Membrane Proteins ; },
abstract = {Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important intestinal pathogen that causes severe foodborne diseases. We previously demonstrated that the genomic island-encoded regulator LmiA activates the locus of enterocyte effacement (LEE) genes to promote EHEC O157:H7 adherence and colonization in the host intestine. However, whether LmiA is involved in the regulation of any other biological processes in EHEC O157:H7 remains largely unexplored. Here, we compared global gene expression differences between the EHEC O157:H7 wild-type strain and an lmiA mutant strain using RNA-seq technology. Genes whose expression was affected by LmiA were identified and classified using the Cluster of Orthologous Groups (COG) database. Specifically, the expression of acid resistance genes (including gadA, gadB, and gadC) was significantly downregulated, whereas the transcript levels of biofilm-related genes (including Z_RS00105, yadN, Z_RS03020, and fdeC) were increased, in the ΔlmiA mutant compared to the EHEC O157:H7 wild-type strain. Further investigation revealed that LmiA enhanced the acid resistance of EHEC O157:H7 by directly activating the transcription of gadA and gadBC. In contrast, LmiA reduced EHEC O157:H7 biofilm formation by indirectly repressing the expression of biofilm-related genes. Furthermore, LmiA-mediated regulation of acid resistance and biofilm formation is highly conserved and widespread among EHEC and enteropathogenic E. coli (EPEC). Our findings provide essential insight into the regulatory function of LmiA in EHEC O157:H7, particularly its role in regulating acid resistance and biofilm formation.},
}

*Escherichia coli O157/genetics/physiology/drug effects
*Biofilms/growth & development/drug effects
*Genomic Islands
*Escherichia coli Proteins/genetics/metabolism
*Gene Expression Regulation, Bacterial
*Acids/pharmacology/metabolism
Escherichia coli Infections/microbiology
Humans
Glutamate Decarboxylase
Membrane Proteins

@article {pmid39690297,
year = {2024},
author = {Ding, J and Yan, Z and Peng, L and Li, J and Yang, F and Zheng, D},
title = {Inhibitory effects of berberine on fungal growth, biofilm formation, virulence, and drug resistance as an antifungal drug and adjuvant with prospects for future applications.},
journal = {World journal of microbiology & biotechnology},
volume = {41},
number = {1},
pages = {5},
pmid = {39690297},
issn = {1573-0972},
mesh = {*Berberine/pharmacology ; *Biofilms/drug effects/growth & development ; *Antifungal Agents/pharmacology ; *Drug Resistance, Fungal ; *Fungi/drug effects ; Humans ; Virulence/drug effects ; Animals ; Mycoses/drug therapy/microbiology ; Microbial Sensitivity Tests ; Virulence Factors ; },
abstract = {Berberine (BBR), an isoquinoline alkaloid found in medicinal plants such as Coptidis rhizoma, Berberis sp., and Hydrastis canadensis, is a distinctive compound known for its dual ability to exhibit broad-spectrum antifungal activity while offering beneficial effects to the host. These attributes make it a highly valuable candidate for antifungal therapy and as an antibiotic adjuvant. This review provides a comprehensive evaluation of BBR's antifungal properties, focusing on its in vitro and in vivo activity, underlying mechanisms, and its influence on fungal pathogenicity, including virulence, biofilm formation, and resistance. Additionally, the antifungal potential of BBR extracts, derivatives, and nanoformulations is examined in detail. BBR demonstrates fungicidal effects through multiple mechanisms. It targets critical fungal components such as mitochondria, cell membranes, and cell walls, while also inhibiting enzymatic activity and transcription processes. Furthermore, it suppresses the expression of virulence factors, effectively diminishing fungal pathogenicity. Beyond its direct antifungal activity, BBR exerts beneficial effects on the host by modulating gut microbiota, thereby bolstering host defenses against fungal infections and reducing potential adverse effects. BBR's interaction with conventional antifungal drugs presents a unique complexity, particularly in the context of resistance mechanisms. When used in combination therapies, conventional antifungal drugs enhance the intracellular accumulation of BBR, thereby amplifying its antifungal potency as the primary active agent. These synergistic effects position BBR as a promising candidate for combination strategies, especially in addressing drug-resistant fungal infections and persistent biofilms. As antifungal resistance and biofilm-associated infections continue to rise, the multifaceted properties of BBR and its advanced formulations highlight their significant therapeutic potential. However, the scarcity of robust in vivo and clinical studies limits a full understanding of its efficacy and safety profile. To bridge this gap, future investigations should prioritize well-designed in vivo and clinical trials to thoroughly evaluate the therapeutic effectiveness and safety of BBR in diverse clinical settings. This approach could pave the way for its broader application in combating fungal infections.},
}

*Berberine/pharmacology
*Biofilms/drug effects/growth & development
*Antifungal Agents/pharmacology
*Drug Resistance, Fungal
*Fungi/drug effects
Humans
Virulence/drug effects
Animals
Mycoses/drug therapy/microbiology
Microbial Sensitivity Tests
Virulence Factors

@article {pmid39689163,
year = {2024},
author = {Yan, X and Liao, H and Wang, C and Huang, C and Zhang, W and Guo, C and Pu, Y},
title = {An improved bacterial single-cell RNA-seq reveals biofilm heterogeneity.},
journal = {eLife},
volume = {13},
number = {},
pages = {},
pmid = {39689163},
issn = {2050-084X},
support = {31970089//National Natural Science Foundation of China/ ; 2021YFC2701602//National Key Research and Development Program of China/ ; 2022CFA077//Science Fund for Distinguished Young Scholars of Hunan Province/ ; 2042022dx0003//Fundamental Research Funds for the Central Universities/ ; GZNL2024A01023//Major Project of Guangzhou National Laboratory/ ; 202001BB050005//Natural Science Foundation of Yunnan Province/ ; },
mesh = {*Biofilms/growth & development ; *Single-Cell Analysis/methods ; *RNA-Seq/methods ; RNA, Bacterial/genetics ; Cyclic GMP/analogs & derivatives/metabolism ; RNA, Ribosomal/genetics ; Escherichia coli/genetics/physiology ; Bacteria/genetics/classification ; Sequence Analysis, RNA/methods ; Single-Cell Gene Expression Analysis ; },
abstract = {In contrast to mammalian cells, bacterial cells lack mRNA polyadenylated tails, presenting a hurdle in isolating mRNA amidst the prevalent rRNA during single-cell RNA-seq. This study introduces a novel method, ribosomal RNA-derived cDNA depletion (RiboD), seamlessly integrated into the PETRI-seq technique, yielding RiboD-PETRI. This innovative approach offers a cost-effective, equipment-free, and high-throughput solution for bacterial single-cell RNA sequencing (scRNA-seq). By efficiently eliminating rRNA reads and substantially enhancing mRNA detection rates (up to 92%), our method enables precise exploration of bacterial population heterogeneity. Applying RiboD-PETRI to investigate biofilm heterogeneity, distinctive subpopulations marked by unique genes within biofilms were successfully identified. Notably, PdeI, a marker for the cell-surface attachment subpopulation, was observed to elevate cyclic diguanylate (c-di-GMP) levels, promoting persister cell formation. Thus, we address a persistent challenge in bacterial single-cell RNA-seq regarding rRNA abundance, exemplifying the utility of this method in exploring biofilm heterogeneity. Our method effectively tackles a long-standing issue in bacterial scRNA-seq: the overwhelming abundance of rRNA. This advancement significantly enhances our ability to investigate the intricate heterogeneity within biofilms at unprecedented resolution.},
}

*Biofilms/growth & development
*Single-Cell Analysis/methods
*RNA-Seq/methods
RNA, Bacterial/genetics
Cyclic GMP/analogs & derivatives/metabolism
RNA, Ribosomal/genetics
Escherichia coli/genetics/physiology
Bacteria/genetics/classification
Sequence Analysis, RNA/methods
Single-Cell Gene Expression Analysis

@article {pmid39688690,
year = {2024},
author = {Bai, XR and Liu, PX and Wang, WC and Jin, YH and Wang, Q and Qi, Y and Zhang, XY and Sun, WD and Fang, WH and Han, XG and Jiang, W},
title = {TssL2 of T6SS2 is required for mobility, biofilm formation, wrinkly phenotype formation, and virulence of Vibrio parahaemolyticus SH112.},
journal = {Applied microbiology and biotechnology},
volume = {108},
number = {1},
pages = {537},
pmid = {39688690},
issn = {1432-0614},
support = {32473039//the Natural Science Foundation of China/ ; 21ZR147700//the Shanghai Natural Science Foundation of China/ ; 17ZR1447200//the Shanghai Natural Science Foundation of China/ ; 31702277//the National Natural Science Foundation of China/ ; 21N31901000//the Shanghai Science and Technology Commission Research Project/ ; 2020JB07//Basic Public Welfare Research Program of Zhejiang Province/ ; },
mesh = {*Biofilms/growth & development ; *Vibrio parahaemolyticus/genetics/pathogenicity/metabolism/physiology ; Animals ; Virulence ; Mice ; *Vibrio Infections/microbiology ; *Type VI Secretion Systems/genetics/metabolism ; *Bacterial Adhesion ; Phenotype ; Bacterial Proteins/genetics/metabolism ; Virulence Factors/genetics/metabolism ; Gene Deletion ; Gene Expression Regulation, Bacterial ; Mice, Inbred BALB C ; Macrophages/microbiology ; },
abstract = {Type VI secretion system 2 (T6SS2) of Vibrio parahaemolyticus is required for cell adhesion and autophagy in macrophages; however, other phenotypes conferred by this T6SS have not been thoroughly investigated. We deleted TssL2, a key component of T6SS2 assembly, to explore the role of the T6SS2 in environmental adaptation and virulence. TssL2 deletion reduced Hcp2 secretion, suggesting that TssL2 played an important role in activity of functional T6SS2. We found that TssL2 was necessary for cell aggregation, wrinkly phenotype formation, and participates in motility and biofilm formation by regulating related genes, suggesting that TssL2 was essential for V. parahaemolyticus to adapt changing environments. In addition, this study demonstrated TssL2 significantly affected adhesion, cytotoxicity, bacterial colonization ability, and mortality in mice, even the levels of the proinflammatory cytokines IL-6 and IL-8, suggesting that TssL2 was involved in bacterial virulence and immunity. Proteome analysis revealed that TssL2 significantly affected the expression of 163 proteins related to ABC transporter systems, flagellar assembly, biofilm formation, and multiple microbial metabolism pathways, some of which supported the effect of TssL2 on the different phenotypes of V. parahaemolyticus. Among them, the decreased expression of the T3SS1 and T2SS proteins was confirmed by the results of gene transcription, which may be the main reason for the decrease in cytotoxicity. Altogether, these findings further our understanding of T6SS2 components on environmental adaption and virulence during bacterial infection. KEY POINTS: • The role of T6SS2 in V. parahaemolyticus was far from clear. • TssL2 participates in cell aggregation, wrinkly phenotype formation, motility, and biofilm formation. • TssL2 is essential for cell bacterial colonization, cytotoxicity, virulence, and proinflammatory cytokine production.},
}

*Biofilms/growth & development
*Vibrio parahaemolyticus/genetics/pathogenicity/metabolism/physiology
Animals
Virulence
Mice
*Vibrio Infections/microbiology
*Type VI Secretion Systems/genetics/metabolism
*Bacterial Adhesion
Phenotype
Bacterial Proteins/genetics/metabolism
Virulence Factors/genetics/metabolism
Gene Deletion
Gene Expression Regulation, Bacterial
Mice, Inbred BALB C
Macrophages/microbiology

@article {pmid39688594,
year = {2024},
author = {Donmez, HG and Sahal, G and Beksac, MS},
title = {Microbial cell-type-based grouping model as a potential indicator of cervicovaginal flora prone to biofilm formation.},
journal = {Biotechnic & histochemistry : official publication of the Biological Stain Commission},
volume = {},
number = {},
pages = {1-6},
doi = {10.1080/10520295.2024.2439447},
pmid = {39688594},
issn = {1473-7760},
abstract = {Cervicovaginal (CV) microbiota is critical for the well-being of host. We investigated the relationship between the ratio of Lactobacilli (LB) and cocci/coccobacilli (C/CB)-type microbial cells with biofilm formation of CV mixed cultures of women with no inflammation/infection or any epithelial abnormalities in Pap-stained smears Group 1 (G1) corresponds to the flora with LB-type cells alone, whereas G2 corresponds to the LB-dominated flora. G3 contains balanced LB and C/CB cells and G4 is dominated with C/CB. G5 corresponds to a flora with C/CB-type cells alone. Biofilm formation of CV mixed cultures was assessed by crystal violet binding assay and optical density (OD)≥0.8 were defined as biofilm producers. G1 and G3 exist in higher frequencies compared to the other smear groups. However, although the frequency of G5 dominated with C/CB-type cells were the lowest (4%); biofilm formation in that group was observed in the highest frequency (42.9%). The least biofilm formation frequency was observed in G3 smears with balanced flora (1%). Biofilm formation in healthy CV flora increases when there becomes an imbalance between LB and C/CB-type cells and an increase in C/CB-type cells. Our approach may enable early detection of vaginal dysbiosis in healthy flora prone to biofilm-associated CV infections such as bacterial vaginosis (BV).},
}

@article {pmid39688394,
year = {2024},
author = {Pang, LM and Zeng, G and Chow, EWL and Xu, X and Li, N and Kok, YJ and Chong, SC and Bi, X and Gao, J and Seneviratne, CJ and Wang, Y},
title = {Sdd3 regulates the biofilm formation of Candida albicans via the Rho1-PKC-MAPK pathway.},
journal = {mBio},
volume = {},
number = {},
pages = {e0328324},
doi = {10.1128/mbio.03283-24},
pmid = {39688394},
issn = {2150-7511},
abstract = {Candida albicans, the most frequently isolated fungal pathogen in humans, forms biofilms that enhance resistance to antifungal drugs and host immunity, leading to frequent treatment failure. Understanding the molecular mechanisms governing biofilm formation is crucial for developing anti-biofilm therapies. In this study, we conducted a genetic screen to identify novel genes that regulate biofilm formation in C. albicans. One identified gene is ORF19.6693, a homolog of the Saccharomyces cerevisiae SDD3 gene. The sdd3∆/∆ mutant exhibited severe defects in biofilm formation and significantly reduced chitin content in the cell wall. Overexpression of the constitutively active version of the Rho1 GTPase Rho1[G18V], an upstream activator of the protein kinase C (PKC)-mitogen-activated protein kinase (MAPK) cell-wall integrity pathway, rescued these defects. Affinity purification, mass spectrometry, and co-immunoprecipitation revealed Sdd3's physical interaction with Bem2, the GTPase-activating protein of Rho1. Deletion of SDD3 significantly reduced the amount of the active GTP-bound form of Rho1, thereby diminishing PKC-MAPK signaling and downregulating chitin synthase genes CHS2 and CHS8. Taken together, our studies identify a new biofilm regulator, Sdd3, in C. albicans that modulates Rho1 activity through its inhibitory interaction with Bem2, thereby regulating the PKC-MAPK pathway to control chitin biosynthesis, which is critical for biofilm formation. As an upstream component of the pathway and lacking a homolog in mammals, Sdd3 has the potential to serve as an antifungal target for biofilm infections.IMPORTANCEThe human fungal pathogen Candida albicans is categorized as a critical priority pathogen on the World Health Organization's Fungal Priority Pathogens List. A key virulence attribute of this pathogen is its ability to form biofilms on the surfaces of indwelling medical devices. Fungal cells in biofilms are highly resistant to antifungal drugs and host immunity, leading to treatment failure. This study conducted a genetic screen to discover novel genes that regulate biofilm formation. We found that deletion of the SDD3 gene caused severe biofilm defects. Sdd3 negatively regulates the Rho1 GTPase, an upstream activator of the protein kinase C-mitogen-activated protein kinase pathway, through direct interaction with Bem2, the GTPase-activating protein of Rho1, resulting in a significant decrease in chitin content in the fungal cell wall. This chitin synthesis defect leads to biofilm formation failure. Given its essential role in biofilm formation, Sdd3 could serve as an antifungal target for biofilm infections.},
}

@article {pmid39687463,
year = {2024},
author = {Shaikh, S and McKay, G and Mackey, HR},
title = {Light intensity effects on bioproduct recovery from fuel synthesis wastewater using purple phototrophic bacteria in a hybrid biofilm-suspended growth system.},
journal = {Biotechnology reports (Amsterdam, Netherlands)},
volume = {44},
number = {},
pages = {e00863},
doi = {10.1016/j.btre.2024.e00863},
pmid = {39687463},
issn = {2215-017X},
abstract = {This research looked at how three different light intensities (1600, 4300, and 7200 lx) affect the biomass development, treatment of fuel synthesis wastewater and the recovery of valuable bioproducts between biofilm and suspended growth in a purple-bacteria enriched photobioreactor. Each condition was run in duplicate using an agricultural shade cloth as the biofilm support media in a continuously mixed batch reactor. The results showed that the highest chemical oxygen demand (COD) removal rate (56.8 ± 0.9 %) was found under the highest light intensity (7200 lx), which also led to the most biofilm formation and highest biofilm biomass production (1225 ± 95.7 mg). The maximum carotenoids (Crts) and bacteriochlorophylls (BChls) content occurred in the suspended growth of the 7200 lx reactor. BChls decreased with light intensity in suspended growth, while in biofilm both Crts and BChls were relatively stable between light conditions, likely due to an averaging effect as biofilm thickened at higher light intensity. Light intensity did not affect protein content of the biomass, however, biofilm showed a lower average (41.2 % to 43.7 %) than suspended biomass (45.4 % to 47.7 %). For polyhydroxybutyrate (PHB) the highest cell concentration in biofilm occurred at 1600 lx (11.4 ± 2.4 %), while for suspended growth it occurred at 7200 lx (22.7 ± 0.3 %), though total PHB productivity remained similar between reactors. Shading effects from the externally located biofilm could explain most variations in bioproduct distribution. Overall, these findings suggest that controlling light intensity can effectively influence the treatment of fuel synthesis wastewater and the recovery of valuable bioproducts in a biofilm photobioreactor.},
}

@article {pmid39684519,
year = {2024},
author = {Markowska, K and Szymanek-Majchrzak, K and Pituch, H and Majewska, A},
title = {Understanding Quorum-Sensing and Biofilm Forming in Anaerobic Bacterial Communities.},
journal = {International journal of molecular sciences},
volume = {25},
number = {23},
pages = {},
pmid = {39684519},
issn = {1422-0067},
mesh = {*Quorum Sensing ; *Biofilms/growth & development ; Bacteria, Anaerobic/physiology ; Humans ; Signal Transduction ; Gene Expression Regulation, Bacterial ; },
abstract = {Biofilms are complex, highly organized structures formed by microorganisms, with functional cell arrangements that allow for intricate communication. Severe clinical challenges occur when anaerobic bacterial species establish long-lasting infections, especially those involving biofilms. These infections can occur in device-related settings (e.g., implants) as well as in non-device-related conditions (e.g., inflammatory bowel disease). Within biofilms, bacterial cells communicate by producing and detecting extracellular signals, particularly through specific small signaling molecules known as autoinducers. These quorum-sensing signals are crucial in all steps of biofilm formation: initial adhesion, maturation, and dispersion, triggering gene expression that coordinates bacterial virulence factors, stimulates immune responses in host tissues, and contributes to antibiotic resistance development. Within anaerobic biofilms, bacteria communicate via quorum-sensing molecules such as N-Acyl homoserine lactones (AHLs), autoinducer-2 (AI-2), and antimicrobial molecules (autoinducing peptides, AIPs). To effectively combat pathogenic biofilms, understanding biofilm formation mechanisms and bacterial interactions is essential. The strategy to disrupt quorum sensing, termed quorum quenching, involves methods like inactivating or enzymatically degrading signaling molecules, competing with signaling molecules for binding sites, or noncompetitively binding to receptors, and blocking signal transduction pathways. In this review, we comprehensively analyzed the fundamental molecular mechanisms of quorum sensing in biofilms formed by anaerobic bacteria. We also highlight quorum quenching as a promising strategy to manage bacterial infections associated with anaerobic bacterial biofilms.},
}

*Quorum Sensing
*Biofilms/growth & development
Bacteria, Anaerobic/physiology
Humans
Signal Transduction
Gene Expression Regulation, Bacterial

@article {pmid39683853,
year = {2024},
author = {Rogala, P and Jabłońska-Wawrzycka, A and Czerwonka, G and Hodorowicz, M and Michałkiewicz, S and Kalinowska-Tłuścik, J and Karpiel, M and Gałczyńska, K},
title = {Ruthenium Complexes with Pyridazine Carboxylic Acid: Synthesis, Characterization, and Anti-Biofilm Activity.},
journal = {Molecules (Basel, Switzerland)},
volume = {29},
number = {23},
pages = {},
doi = {10.3390/molecules29235694},
pmid = {39683853},
issn = {1420-3049},
support = {Project UJK No. SUPB.RN. 24.218, SUPB.RN. 24.219, SUPB.RN. 23.256//Polish Ministry of Science and Higher Education/ ; },
mesh = {*Biofilms/drug effects ; *Ruthenium/chemistry/pharmacology ; *Anti-Bacterial Agents/pharmacology/chemistry/chemical synthesis ; *Carboxylic Acids/chemistry/pharmacology ; *Pyridazines/chemistry/pharmacology/chemical synthesis ; *Microbial Sensitivity Tests ; *Coordination Complexes/pharmacology/chemistry/chemical synthesis ; Pseudomonas aeruginosa/drug effects ; Molecular Structure ; },
abstract = {As a result of drug resistance, many antimicrobial medicines become ineffective, making the infections more difficult to treat. Therefore, there is a need to develop new compounds with antibacterial activity. This role may be played, for example, by metal complexes with carboxylic acids. This study reports the formation and characterization of ruthenium complexes with pyridazine-3-carboxylic acid (pdz-3-COOH)-([(η[6]-p-cym)Ru[II]Cl(pdz-3-COO)] (1), [Ru[III]Cl2(pdz-3-COO)2Na(H2O)]n(H2O)0.11 (2) and [Ru[III]Cl2(pdz-3-COO)2Na(H2O)2]n (3). The synthesized compounds were analyzed using various spectroscopic and electrochemical techniques, with structure confirmation via SC-XRD analysis. Experimental data showed the ligand binds to metal ions bidentately through the nitrogen donor of the pyridazine ring and one carboxylate oxygen. To visualize intermolecular interactions, Hirshfeld surface analysis and 2D fingerprint plots were conducted. Furthermore, the impact of ruthenium compounds (1 and 2) on the planktonic growth of selected bacterial strains and the formation of Pseudomonas aeruginosa PAO1 biofilm was examined. Both complexes demonstrated comparable anti-biofilm activity and outperformed the free ligand. The effect of the complexes on selected virulence factors of P. aeruginosa PAO1 was also investigated. Compounds 1 and 2 show high suppressive activity in pyoverdine production, indicating that the virulence of the strain has been reduced. This inhibitory effect is similar to the inhibitory effect of ciprofloxacin. Within this context, the complexes exhibit promising antibacterial activities. Importantly, the compounds showed no cytotoxic effects on normal CHO-K1 cells. Additionally, a molecular docking approach and fluorescence spectroscopy were used to determine the interactions of ruthenium complexes with human serum albumin.},
}

*Biofilms/drug effects
*Ruthenium/chemistry/pharmacology
*Anti-Bacterial Agents/pharmacology/chemistry/chemical synthesis
*Carboxylic Acids/chemistry/pharmacology
*Pyridazines/chemistry/pharmacology/chemical synthesis
*Microbial Sensitivity Tests
*Coordination Complexes/pharmacology/chemistry/chemical synthesis
Pseudomonas aeruginosa/drug effects
Molecular Structure

@article {pmid39682912,
year = {2024},
author = {Peng, J and Chen, G and Guo, S and Lin, Z and Zeng, Y and Ren, J and Wang, Q and Yang, W and Liang, Y and Li, J},
title = {Anti-Bacterial and Anti-Biofilm Activities of Essential Oil from Citrus reticulata Blanco cv. Tankan Peel Against Listeria monocytogenes.},
journal = {Foods (Basel, Switzerland)},
volume = {13},
number = {23},
pages = {},
pmid = {39682912},
issn = {2304-8158},
support = {32402274//Natural Science Foundation of China/ ; 2023KTSCX051//Guangdong Universities Characteristic Innovation Project/ ; 2021A1515110660//Guangdong Basic and Applied Basic Research Foundation/ ; SL2022A04J01086//Guangzhou Basic and Applied Basic Research Foundation/ ; Heyuan2021016//Guangdong Science and Technology Special Project/ ; },
abstract = {In recent years, plant essential oils have been confirmed as natural inhibitors of foodborne pathogens. Citrus reticulata Blanco cv. Tankan peel essential oil (CPEO) showed anti-Listeria monocytogenes (LM) activities, and this study investigated the associated mechanisms by using high-resolution electron microscope, fluorescence spectrometer, flow cytometer, potentiometer, and transcriptome sequencing. The results showed that CPEO restrained LM growth at a minimum inhibitory concentration of 2% (v/v). The anti-LM abilities of CPEO were achieved by disrupting the permeability of the cell wall, damaging the permeability, fluidity, and integrity of the cell membrane, disturbing the membrane hydrophobic core, and destroying the membrane protein conformation. Moreover, CPEO could significantly inhibit the LM aggregation from forming biofilm by reducing the extracellular polymeric substances' (protein, polysaccharide, and eDNA) production and bacterial surface charge numbers. The RNA sequencing data indicated that LM genes involved in cell wall and membrane biosynthesis, DNA replication and repair, quorum sensing and two-component systems were expressed differently after CPEO treatment. These results suggested that CPEO could be used as a novel anti-LM agent and green preservative in the food sector. Further studies are needed to verify the anti-LM activities of CPEO in real food.},
}

@article {pmid39682909,
year = {2024},
author = {D'Arcangelo, S and Santonocito, D and Messina, L and Greco, V and Giuffrida, A and Puglia, C and Di Giulio, M and Inturri, R and Vaccaro, S},
title = {Almond Hull Extract Valorization: From Waste to Food Recovery to Counteract Staphylococcus aureus and Escherichia coli in Formation and Mature Biofilm.},
journal = {Foods (Basel, Switzerland)},
volume = {13},
number = {23},
pages = {},
pmid = {39682909},
issn = {2304-8158},
abstract = {The increase in food waste accumulation needs innovative valorization strategies that not only reduce environmental impacts but also provide functional applications. This study investigates the potential of almond hulls, an abundant agricultural by-product, as a source of bioactive compounds. For the first time, almond hull extract (AHE), was evaluated in terms of anti-adhesive and anti-biofilm activity against Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 9637. The extract was obtained by an optimized eco-friendly green technique using ultrasound-assisted extraction (UAE), and it was characterized for its main compounds by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and nuclear magnetic resonance (NMR) analysis. Antimicrobial activity was evaluated on planktonic cells by minimum inhibitory/bactericidal concentration (MIC/MBC) and by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. Afterward, AHE activity was evaluated against the bacterial sessile phase, both against in-formation and mature biofilm. Finally, the toxicity of the extract was tested on normal human adult cells (HDFa) by an MTT test. The principal active compounds present in AHE belong to the polyphenol group, in particular, the phenolic acid (Hydroxycinnammic sub-class) and, more significantly, the flavonoid class. The results showed that the extract has a relevant antimicrobial activity against the planktonic cells of both tested strains. Moreover, it significantly inhibited bacterial adhesion and promoted biofilm removal, highlighting its potential as a sustainable antimicrobial agent. The MTT test on human fibroblasts showed that the extract is not toxic for normal human cells. This research highlights how food waste valorization could have a high potential in the antimicrobial field.},
}

@article {pmid39682895,
year = {2024},
author = {Panera-Martínez, S and Capita, R and Pedriza-González, Á and Díez-Moura, M and Riesco-Peláez, F and Alonso-Calleja, C},
title = {Occurrence, Antibiotic Resistance and Biofilm-Forming Ability of Listeria monocytogenes in Chicken Carcasses and Cuts.},
journal = {Foods (Basel, Switzerland)},
volume = {13},
number = {23},
pages = {},
doi = {10.3390/foods13233822},
pmid = {39682895},
issn = {2304-8158},
support = {RTI2018-098267-R-C33//Ministerio de Ciencia, Innovación y Universidades/ ; PID2022-142329OB-C31//Ministerio deCiencia, Innovación y Universidades/ ; LE018P20//Junta de Castilla y León (Consejería de Educación)/ ; },
abstract = {A total of 104 samples of chicken meat acquired on the day of slaughter from two slaughterhouses in northwestern Spain were analyzed. These comprised 26 carcasses and 26 cuts from each of the two establishments. An average load of 5.39 ± 0.61 log10 cfu/g (total aerobic counts) and 4.90 ± 0.40 log10 cfu/g (psychrotrophic microorganisms) were obtained, with differences (p < 0.05) between types of samples and between slaughterhouses. Culturing methods involving isolation based on the UNE-EN-ISO 11290-1:2018 norm and identification of isolates by polymerase chain reaction (PCR) to detect the lmo1030 gene allowed the detection of Listeria monocytogenes in 75 samples (72.1% of the total; 50.0% of the carcasses and 94.2% of the cuts). The 75 isolates, one for each positive sample, were tested for resistance against a panel of 15 antibiotics of clinical interest by the disc diffusion method. All isolates belonged to the serogroup IIa (multiplex PCR assay) and showed resistance to between four and ten antibiotics, with an average value of 5.7 ± 2.0 resistances per isolate, this rising to 7.0 ± 2.1 when strains with resistance and reduced susceptibility were taken together. A high prevalence of resistance was observed for antibiotics belonging to the cephalosporin and quinolone families. However, the level of resistance was low for antibiotics commonly used to treat listeriosis (e.g., ampicillin or gentamicin). Nine different resistance patterns were noted. One isolate with each resistance pattern was tested for its ability to form biofilms on polystyrene during 72 h at 12 °C. The total biovolume of the biofilms registered through confocal laser scanning microscopy (CLSM) in the observation field of 16,078.24 μm[2] ranged between 13,967.7 ± 9065.0 μm[3] and 33,478.0 ± 23,874.1 μm[3], and the biovolume of inactivated bacteria between 0.5 ± 0.4 μm[3] and 179.1 ± 327.6 μm[3]. A direct relationship between the level of resistance to antibiotics and the ability of L. monocytogenes strains to form biofilms is suggested.},
}

@article {pmid39681855,
year = {2024},
author = {Chen, T and Zhou, X and Feng, R and Shi, S and Chen, X and Wei, B and Hu, Z and Peng, T},
title = {Author Correction: Novel function of single-target regulator NorR involved in swarming motility and biofilm formation revealed in Vibrio alginolyticus.},
journal = {BMC biology},
volume = {22},
number = {1},
pages = {285},
pmid = {39681855},
issn = {1741-7007},
}

@article {pmid39680756,
year = {2024},
author = {Syed, AK and Baral, R and Van Vlack, ER and Gil-Marqués, ML and Lenhart, T and Hooper, DC and Kahne, D and Losick, R and Bradshaw, N},
title = {Biofilm formation by Staphylococcus aureus is triggered by a drop in the levels of a cyclic dinucleotide.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {121},
number = {52},
pages = {e2417323121},
doi = {10.1073/pnas.2417323121},
pmid = {39680756},
issn = {1091-6490},
support = {5R01 AI139011//HHS | National Institutes of Health (NIH)/ ; R01 AI057576/AI/NIAID NIH HHS/United States ; startup funds//Brandeis University (BU)/ ; fellowship//Real Colegio Complutense Fellowship/ ; },
mesh = {*Biofilms/growth & development ; *Staphylococcus aureus/genetics/physiology/metabolism ; *Bacterial Proteins/metabolism/genetics ; Animals ; Mice ; Dinucleoside Phosphates/metabolism ; Gene Expression Regulation, Bacterial ; Phosphoric Diester Hydrolases/metabolism/genetics ; Staphylococcal Infections/microbiology ; Glucose/metabolism ; Second Messenger Systems ; },
abstract = {The bacterial pathogen Staphylococcus aureus forms multicellular communities known as biofilms in which cells are held together by an extracellular matrix principally composed of repurposed cytoplasmic proteins and extracellular DNA. These biofilms assemble during infections or under laboratory conditions by growth on medium containing glucose, but the intracellular signal for biofilm formation and its downstream targets were unknown. Here, we present evidence that biofilm formation is triggered by a drop in the levels of the second messenger cyclic-di-AMP. Previous work identified genes needed for the release of extracellular DNA, including genes for the cyclic-di-AMP phosphodiesterase GdpP, the transcriptional regulator XdrA, and the purine salvage enzyme Apt. Using a cyclic-di-AMP riboswitch biosensor and mass spectrometry, we show that the second messenger drops in abundance during biofilm formation in a glucose-dependent manner. Mutation of these three genes elevates cyclic-di-AMP and prevents biofilm formation in a murine catheter model. Supporting the generality of this mechanism, we found that gdpP was required for biofilm formation by diverse strains of S. aureus. We additionally show that the downstream consequence of the drop in cyclic-di-AMP is inhibition of the "accessory gene regulator" operon agr, which is known to suppress biofilm formation through phosphorylation of the transcriptional regulator AgrA by the histidine kinase AgrC. Consistent with this, an agr mutation bypasses the block in biofilm formation and eDNA release caused by a gdpP mutation. Finally, we report the unexpected observation that GdpP inhibits phosphotransfer from AgrC to AgrA, revealing a direct connection between the phosphodiesterase and agr.},
}

*Biofilms/growth & development
*Staphylococcus aureus/genetics/physiology/metabolism
*Bacterial Proteins/metabolism/genetics
Animals
Mice
Dinucleoside Phosphates/metabolism
Gene Expression Regulation, Bacterial
Phosphoric Diester Hydrolases/metabolism/genetics
Staphylococcal Infections/microbiology
Glucose/metabolism
Second Messenger Systems

@article {pmid39680392,
year = {2024},
author = {Kishimoto, T and Fukuda, K and Ishida, W and Kuwana, A and Todokoro, D and Uchiyama, J and Matsuzaki, S and Yamashiro, K},
title = {Disruption of the Enterococcus faecalis-Induced Biofilm on the Intraocular Lens Using Bacteriophages.},
journal = {Translational vision science & technology},
volume = {13},
number = {12},
pages = {25},
doi = {10.1167/tvst.13.12.25},
pmid = {39680392},
issn = {2164-2591},
mesh = {*Biofilms/growth & development/drug effects ; *Enterococcus faecalis/virology/physiology ; *Lenses, Intraocular/microbiology ; *Bacteriophages/genetics/physiology ; *Vancomycin/pharmacology ; Humans ; Anti-Bacterial Agents/pharmacology ; Microscopy, Electron, Scanning ; Gram-Positive Bacterial Infections/microbiology ; },
abstract = {PURPOSE: To compare the effects of bacteriophages (phages) and vancomycin on Enterococcus faecalis-induced biofilms on the intraocular lens.

METHODS: E. faecalis strains EF24, GU02, GU03, and phiEF14H1 were used. The expression of the enterococcus surface protein (esp) gene was analyzed using polymerase chain reaction. Phages or vancomycin was added to the biofilms formed on culture plates or acrylic intraocular lenses. The biofilms were quantified after staining with crystal violet. The structure of the biofilms was analyzed using scanning electron microscopy.

RESULTS: E. faecalis strains EF24, GU02, and GU03 formed biofilms on cell culture plates; however, the esp-negative GU03 strain had a significantly lower biofilm-forming ability than the esp-positive strains EF24 and GU02. The addition of phiEF14H1 resulted in a significant reduction in biofilm mass produced by both EF24 and GU02 compared with the untreated control. However, the addition of vancomycin did not degrade the biofilms. Phages significantly degraded biofilms and reduced the viable EF24 and GU02 bacteria on the intraocular lens.

CONCLUSIONS: Phages can degrade biofilms formed on the intraocular lens and destroy the bacteria within it. Thus, phage therapy may be a new treatment option for refractory and recurrent endophthalmitis caused by biofilm-forming bacteria.

TRANSLATIONAL RELEVANCE: Phage therapy, a novel treatment option for refractory and recurrent endophthalmitis caused by biofilm-forming bacteria, effectively lyses E. faecalis-induced biofilms.},
}

*Biofilms/growth & development/drug effects
*Enterococcus faecalis/virology/physiology
*Lenses, Intraocular/microbiology
*Bacteriophages/genetics/physiology
*Vancomycin/pharmacology
Humans
Anti-Bacterial Agents/pharmacology
Microscopy, Electron, Scanning
Gram-Positive Bacterial Infections/microbiology

@article {pmid39678983,
year = {2024},
author = {Sharma, A and Kumar, Y and Kumar, G and Tahlan, AK},
title = {Biofilm Production and Antibiogram Profiles in Escherichia coli and Salmonella.},
journal = {Indian journal of microbiology},
volume = {64},
number = {4},
pages = {1512-1517},
pmid = {39678983},
issn = {0046-8991},
abstract = {Salmonella and Escherichia coli are important enteric pathogens associated with a variety of infections. Biofilm formation and antimicrobial resistance are important characteristics making these pathogens a concern in terms of strong attachment to substrates, expression of virulence markers and difficult removal. The present study investigates the biofilm-forming ability and antibiogram patterns among E. coli and Salmonella spp. A total of 200 E. coli and 100 Salmonella isolates received at National Salmonella and Escherichia Centre were identified by biochemical testing, followed by serotyping. Biofilm production was detected by Tissue Culture Plate method. The isolates were further subjected to Antibiotic Susceptibility Testing by the Kirby-Bauer disk diffusion method. 113 (56.5%) E. coli isolates and 79 (79%) Salmonella isolates were detected as biofilm producers. A total of 114(57%)E. coli isolates and 31(31%) Salmonella isolates were found to be resistant to multiple drugs when Antibiotic Susceptibility Testing was carried out. Antibiotic resistance was found to be significantly higher in biofilm producing salmonella (p = 0.001) whereas in the case of E. coli the difference remained non-significant (p = 0.4454). The capability to produce biofilm along with acquiring high level of antimicrobial resistance in salmonella and E. coli provide enhanced survival potential in adverse environments. Therefore, it becomes a serious cause of concern for public health authorities considering the virulence of these bacteria and their association with different disease conditions and requires urgent intervention with regards to control and prevention strategies.},
}

@article {pmid39678958,
year = {2024},
author = {Jin, HW and Eom, YB},
title = {Antibacterial and Anti-biofilm Effects of Thymoquinone Against Carbapenem-Resistant Uropathogenic Escherichia coli.},
journal = {Indian journal of microbiology},
volume = {64},
number = {4},
pages = {1747-1756},
pmid = {39678958},
issn = {0046-8991},
abstract = {Carbapenem antibiotics are widely used for their broad antibacterial effects, but the emergence of carbapenem-resistant Enterobacterales has recently become a global problem. To solve this problem, research is needed to find compounds that increase antibiotic activity. Therefore, this study aimed to validate the antibacterial and anti-biofilm effects, as well as the inhibition of gene expression of thymoquinone, an extract of Nigella sativa commonly used as a spice in many dishes. The minimum inhibitory concentration of carbapenem antibiotics and thymoquinone was determined. Phenotypic analysis was performed to confirm the effect of thymoquinone on motility, which is one of the virulence factors of carbapenem-resistant uropathogenic Escherichia coli (CR-UPEC). Furthermore, quantitative real-time polymerase chain reaction analysis was used to determine the expression levels of carbapenemase gene (bla KPC), efflux pump genes (acrA, acrB, acrD, tolC), as well as motility and adhesion genes (fliC, motA). In addition, biofilm inhibition and biofilm eradication assays were performed. All strains showed resistance to carbapenem antibiotics, while an antibacterial effect was confirmed at a concentration of 256 μg/mL of thymoquinone. Phenotypic analysis revealed a nearly 50% suppression in migration distance compared to the control group at 128 μg/mL of thymoquinone. Subsequent gene expression tests indicated the downregulation of carbapenemase-, efflux pump-, motility-, and adhesion genes by thymoquinone. Furthermore, our findings demonstrated that thymoquinone exhibits both biofilm formation inhibition and eradication effects. These findings suggest that thymoquinone may serve as a potential antibiotic adjuvant for treating CR-UPEC and could be a valuable resource in combating UTIs caused by multidrug-resistant bacteria.},
}

@article {pmid39678029,
year = {2024},
author = {Ye, Z and van der Wildt, B and Nurmohamed, FRHA and van Duyvenbode, JFFH and van Strijp, J and Vogely, HC and Lam, MGEH and Dadachova, E and Weinans, H and van der Wal, BCH and Poot, AJ},
title = {Radioimmunotherapy combating biofilm-associated infection in vitro.},
journal = {Frontiers in medicine},
volume = {11},
number = {},
pages = {1478636},
pmid = {39678029},
issn = {2296-858X},
abstract = {BACKGROUND: Addressing prosthetic joint infections poses a significant challenge within orthopedic surgery, marked by elevated morbidity and mortality rates. The presence of biofilms and infections attributed to Staphylococcus aureus (S. aureus) further complicates the scenario.

OBJECTIVE: To investigate the potential of radioimmunotherapy as an innovative intervention to tackle biofilm-associated infections.

METHODS: Our methodology involved employing specific monoclonal antibodies 4497-IgG1, designed for targeting wall teichoic acids found on S. aureus and its biofilm. These antibodies were linked with radionuclides actinium-225 ([225]Ac) and lutetium-177 ([177]Lu) using DOTA as a chelator. Following this, we evaluated the susceptibility of S. aureus and its biofilm to radioimmunotherapy in vitro, assessing bacterial viability and metabolic activity via colony-forming unit enumeration and xylenol tetrazolium assays.

RESULTS: Both [[225]Ac]4497-IgG1 and [[177]Lu]4497-IgG1 exhibited a noteworthy dose-dependent reduction in S. aureus in planktonic cultures and biofilms over a 96-h exposure period, compared to non-specific antibody control groups. Specifically, doses of 7.4 kBq and 7.4 MBq of [[225]Ac]4497-IgG1 and [[177]Lu]4497-IgG1 resulted in a four-log reduction in planktonic bacterial counts. Within biofilms, 14.8 kBq of [[225]Ac]4497-IgG1 and 14.8 Mbq [[177]Lu]4497-IgG1 led to reductions of two and four logs, respectively.

CONCLUSION: Our findings underscore the effectiveness of [[225]Ac]4497-IgG1 and [[177]Lu]4497-IgG1 antibodies in exerting dose-dependent bactericidal effects against planktonic S. aureus and biofilms in vitro. This suggests that radioimmunotherapy might serve as a promising targeted treatment approach for combating S. aureus and its biofilm.},
}

@article {pmid39677627,
year = {2024},
author = {Bhattacharya, M and Scherr, TD and Lister, J and Kielian, T and Horswill, AR},
title = {Matrix porosity is associated with Staphylococcus aureus biofilm survival during prosthetic joint infection.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2024.12.06.627279},
pmid = {39677627},
issn = {2692-8205},
abstract = {Biofilms are a cause of chronic, non-healing infections. Staphylococcus aureus is a proficient biofilm forming pathogen commonly isolated from prosthetic joint infections that develop following primary arthroplasty. Extracellular adhesion protein (Eap), previously characterized in planktonic or non-biofilm populations as being an adhesin and immune evasion factor, was recently identified in the exoproteome of S. aureus biofilms. This work demonstrates that Eap and its two functionally orphaned homologs EapH1 and EapH2, contribute to biofilm structure and prevent macrophage invasion and phagocytosis into these communities. Biofilms unable to express Eap proteins demonstrated increased porosity and reduced biomass. We describe a role for Eap proteins in vivo using a mouse model of S. aureus prosthetic joint infection. Results suggest that the protection conferred to biofilms by Eap proteins is a function of biofilm structural stability that interferes with the leukocyte response to biofilm-associated bacteria.},
}

@article {pmid39677066,
year = {2024},
author = {Gebremariam, T and Eguale, T and Belay, T and Kalayu, AA and Abula, T and Engidawork, E},
title = {Antibiotic Resistance, and Biofilm Forming Characteristics of Escherichia coli Clinical Isolates at a Hospital in Tigray, Northern Ethiopia.},
journal = {Cureus},
volume = {16},
number = {11},
pages = {e73569},
pmid = {39677066},
issn = {2168-8184},
abstract = {BACKGROUND: Escherichia coli (E. coli) infections are becoming difficult to treat due to the bacterium's biofilm-forming capabilities and rising resistance to multiple antibiotics, posing a growing clinical challenge. This study assessed the antimicrobial resistance and biofilm formation by Escherichia coli isolates from patients at a hospital in Tigray, Northern Ethiopia.

METHOD: From patients exhibiting signs of bacterial infection, while excluding recent antibiotic users or those with incomplete data, 417 clinical samples comprised of 84 blood, 108 pus, and 225 urine samples were obtained in a cross-sectional study. The combination disc method was used to test extended-spectrum beta-lactamase (ESBL) production, and Ampicillin C (AmpC) enzyme presence was confirmed with cefoxitin and cefotaxime discs. Data analysis was conducted with SPSS version 22 software, applying ANOVA and logistic regression, with significance set at p<0.05.

RESULT: Among the 417 samples, 109 (26.1%) tested positive for Escherichia coli. These isolates showed high resistance to ampicillin (84.4%) but lower resistance to meropenem (9.17%). ESBL was detected in 46.8% of isolates and AmpC in 54%, with 48 (44%) isolates positive for both. Strong biofilm formation occurred in 76% of isolates, while only 2.75% were weak producers. Biofilm strength correlated significantly with prior antibiotic use (p=0.028), ward type (p=0.001), and use of indwelling devices (p=0.000).

CONCLUSION: In northern Ethiopia, Escherichia coli isolates showed resistance to major antibiotic classes like beta-lactams, fluoroquinolones, and aminoglycosides. This high resistance and biofilm development highlight the critical need for interventions to curb resistance spread, with a focus on antibiofilm research and enhanced infection prevention measures.},
}

@article {pmid39676255,
year = {2024},
author = {Shankar Das, B and Sarangi, A and Pahuja, I and Singh, V and Ojha, S and Giri, S and Bhaskar, A and Bhattacharya, D},
title = {Thymol as Biofilm and Efflux Pump Inhibitor: A Dual-Action Approach to Combat Mycobacterium tuberculosis.},
journal = {Cell biochemistry and function},
volume = {42},
number = {8},
pages = {e70030},
doi = {10.1002/cbf.70030},
pmid = {39676255},
issn = {1099-0844},
support = {//This work was supported by the grant provided from DST-SERB, Government of India (SRG/2020/001922) and UGC, Government of India (UGC FD Diary No. 2183, 01-06-2022 & No. F.30-523/2020(BSR). Part of the work was also supported by initial funding provided to DB in IISER, Bhopal./ ; },
mesh = {*Biofilms/drug effects ; *Thymol/pharmacology/chemistry ; *Mycobacterium tuberculosis/drug effects/metabolism ; *Microbial Sensitivity Tests ; *Antitubercular Agents/pharmacology/chemistry ; Mycobacterium smegmatis/drug effects/metabolism ; Molecular Docking Simulation ; Bacterial Proteins/metabolism/antagonists & inhibitors ; Rifampin/pharmacology ; Reactive Oxygen Species/metabolism ; Isoniazid/pharmacology ; Membrane Transport Proteins/metabolism ; },
abstract = {Tuberculosis (TB) remains a significant global health challenge, exacerbated by the emergence of drug-resistant strains of Mycobacterium tuberculosis (M. tb). The complex biology of M. tb, particularly its key porins, contributes to its resilience against conventional treatments, highlighting the exploration of innovative therapeutic strategies. Following with this challenges, the present study investigates the bioactivity properties of phenolic compounds derived from the terpene groups, specifically through Thymol (THY) against M. smegmatis as a surrogated model for M. tb. Furthermore, the study employed with combination of two approaches i.e., in vitro assays and computational methods to evaluate the efficacy of THY against M. smegmatis and its interaction with M. tb biofilm and efflux pump proteins, particularly Rv1258c and Rv0194. The in vitro findings demonstrated that THY exhibits inhibitory activity against M. smegmatis and shows promising interaction with a combination of isoniazid (INH) and rifampicin (RIF) of TB regimens. Furthermore, THY demonstrated significant inhibitory action towards motility and biofilm formation of M. smegmatis. The combination of THY with INH and RIF exhibited a synergistic effect, enhancing the overall antimicrobial efficacy. Additionally, THY displayed reactive oxygen species (ROS) activity and potential efflux pump inhibitory action towards M. smegmatis. The computational analysis revealed that THY interacts effectively with efflux pump proteins Rv1258c and Rv0194, showing superior binding affinity compared to verapamil, a known efflux pump inhibitor. Pharmacokinetic studies highlighted that THY possess a favourable safety profile. In conclusion, THY represents a promising inhibitory compound for tuberculosis prevention, potentially addressing challenges posed by drug resistance.},
}

*Biofilms/drug effects
*Thymol/pharmacology/chemistry
*Mycobacterium tuberculosis/drug effects/metabolism
*Microbial Sensitivity Tests
*Antitubercular Agents/pharmacology/chemistry
Mycobacterium smegmatis/drug effects/metabolism
Molecular Docking Simulation
Bacterial Proteins/metabolism/antagonists & inhibitors
Rifampin/pharmacology
Reactive Oxygen Species/metabolism
Isoniazid/pharmacology
Membrane Transport Proteins/metabolism

@article {pmid39675511,
year = {2024},
author = {Wang, Y and Liu, Y and Chen, J and Ge, Z and Wang, J and Li, D},
title = {D-arginine-loaded pH-responsive mesoporous silica nanoparticles enhances the efficacy of water jet therapy in decontaminating biofilm-coated titanium surface.},
journal = {Journal of controlled release : official journal of the Controlled Release Society},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jconrel.2024.12.020},
pmid = {39675511},
issn = {1873-4995},
abstract = {Peri-implantitis, caused by bacterial biofilm on dental implants, leads to bone loss and tissue inflammation, ultimately causing oral health decline. Traditional methods to remove biofilm are ineffective in promoting reosseointegration on implant surfaces. This phenomenon can be attributed to two factors: incomplete removal of biofilm from hard-to-reach areas and alterations in the physicochemical properties of implant surfaces caused by decontamination procedures. To address this problem, we developed D-arginine-loaded chitooligosaccharide-capped pH-responsive mesoporous silica nanoparticles (Dar@MSN-COS) for improving the efficacy of decontamination of Water Jet (WJ). Dar@MSN-COS particles exhibit a targeted approach towards the extracellular polymeric substance (EPS) in order to disrupt the biofilm, and possess the capability to infiltrate confined areas between implant screws. Following this, the WJ treatment effectively removed residual biofilm and demonstrated improved cleaning efficacy. Furthermore, the decontamination of the Dar@MSN-COS combination with WJ promotes effective cell cytocompatibility on the titanium surface. The results of mechanistic experiments indicate that Dar@MSN-COS may act on biofilms by releasing a significant quantity of reactive oxygen species (ROS), suggesting it as a key contributing factor. In summary, our novel therapeutic protocol shows promise as an alternative solution for addressing the clinically complex aspects of peri-implantitis.},
}

@article {pmid39675440,
year = {2024},
author = {Musinguzi, B and Akampurira, A and Derick, H and Turyamuhika, L and Mwesigwa, A and Mwebesa, E and Mwesigye, V and Kabajulizi, I and Sekulima, T and Ocheng, F and Itabangi, H and Mboowa, G and Sande, OJ and Achan, B},
title = {Extracellular Hydrolytic Enzyme Activities and Biofilm Formation in Candida species Isolated from People Living with Human Immunodeficiency Virus with Oropharyngeal Candidiasis at HIV/AIDS Clinics in Uganda.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107232},
doi = {10.1016/j.micpath.2024.107232},
pmid = {39675440},
issn = {1096-1208},
abstract = {BACKGROUND: Commensal oral Candida species can become opportunistic and transition to pathogenic causes of oropharyngeal candidiasis (OPC) in individuals with impaired immunity through ecological cues and the expression of extracellular hydrolytic enzyme activities and biofilm formation.

OBJECTIVE: We evaluated phospholipase, proteinase, hemolysin, esterase, and coagulase enzymatic activities and biofilm formation in Candida species isolated from people living with human immunodeficiency virus (PLHIV) with OPC.

METHODS: Thirty-five Candida isolates from PLHIV with OPC were retrieved from a sample repository and evaluated for phospholipase activity using the egg yolk agar method, proteinase activity using the bovine serum albumin agar method, hemolysin activity using the blood agar plate method, esterase activity using the Tween 80 opacity test medium method, coagulase activity using the classical tube method, and biofilm formation using the microtiter plate assay method in vitro.

RESULTS: A total of 35 Candida isolates obtained from PLHIV with OPC were included in this study, and phospholipase and proteinase activities were detected in 33/35 (94.3%) and 31/35 (88.6%) Candida isolates, respectively. Up to 25/35 (71.4%) of the Candida isolates exhibited biofilm formation, whereas esterase activity was demonstrated in 23/35 (65.7%) of the Candida isolates. Fewer isolates (21/35, 60%) produced hemolysin, and coagulase production was the least common virulence activity detected in 18/35 (51.4%) of the Candida isolates.

CONCLUSION: Phospholipase and proteinase activities were the strongest in oropharyngeal Candida species.},
}

@article {pmid39674811,
year = {2024},
author = {Machida-Sano, I and Koizumi, H and Yoshitake, S},
title = {A novel scaffold for biofilm formation by soil microbes using iron-cross-linked alginate gels.},
journal = {Bioscience, biotechnology, and biochemistry},
volume = {},
number = {},
pages = {},
doi = {10.1093/bbb/zbae197},
pmid = {39674811},
issn = {1347-6947},
abstract = {This study aimed to evaluate the suitability of alginate gels, specifically ferric-ion-cross-linked alginate (Fe-alginate) and calcium-ion-cross-linked alginate (Ca-alginate), as scaffolds for soil microbial attachment and biofilm formation in soil. Staining with crystal violet and observations with scanning electron microscopy showed that microorganisms formed biofilms on Fe-alginate surfaces in the soil. When the soil was incubated with Fe-alginate, microbial biomass, estimated by adenosine triphosphate content, increased not only in the Fe-alginate but also in the surrounding soil. The weight of Ca-alginate in the soil decreased with time owing to chemical dissolution. However, the weight of Fe-alginate in the soil did not decrease, likely because it was protected by the microbial biofilm that formed on its surface. These results demonstrate that the use of Fe-alginate, in contrast to Ca-alginate, as a scaffold may allow for more efficient use of soil microbial functions in agriculture and bioremediation.},
}

@article {pmid39674248,
year = {2024},
author = {Fan, F and Li, M and Dou, J and Zhang, J and Li, D and Meng, F and Dong, Y},
title = {Functional characteristics and mechanisms of microbial community succession and assembly in a long-term moving bed biofilm reactor treating real municipal wastewater.},
journal = {Environmental research},
volume = {},
number = {},
pages = {120602},
doi = {10.1016/j.envres.2024.120602},
pmid = {39674248},
issn = {1096-0953},
abstract = {Moving bed biofilm reactor (MBBR) technology with diverse merits is efficient in treating various waste streams whereas their microbial functional properties and ecology still need in-depth investigation, especially in real wastewater treatment systems. Herein, a well-controlled MBBR treating municipal wastewater was established to investigate the long-term system performance and the underlying principles of community succession and assembly. The system successfully achieved ammonium, TN, and chemical oxygen demand (COD) removal of 96.7 ± 2.2%, 75.2 ± 3.6%, and 90.3 ± 3.8%, respectively, under simplified operation and low energy consumption. The effluent TN concentrations achieved 6.2 ± 1.6 mg-N/L despite the influent fluctuations. Diverse functional denitrifiers, such as Denitratisoma, Thermomonas, and Flavobacterium, and the anammox bacteria Candidatus Brocadia successfully enriched in anoxic chamber biofilms. The nitrifiers Nitrosomonas (∼0.73%) and Nitrospira (∼14.0%) exhibited appreciable nitrification capacity in specialized aerobic chambers. Ecological null model and network analysis revealed that microbial community assembly was mainly regulated by niche-based deterministic processes and air diffusion in aerobic chamber resulted in more intense and complex bacterial interactions. Environmental filters including influent substrate and operating conditions (e.g., reactor configuration, DO, and temperature) greatly shaped the microbial community structure and affected carbon and nitrogen metabolism. The positive ecological roles of influent microflora and functional redundancy in biofilm communities were believed to facilitate functional stability. The anammox process coupled with partial denitrification in a specialized chamber demonstrated positive application implications. These findings provided valuable perspectives in deciphering the microbiological and ecological mechanisms, the functional properties, and the MBBR application potentials.},
}

@article {pmid39674004,
year = {2024},
author = {Zhang, J and Yang, P and Zeng, Q and Zhang, Y and Zhao, Y and Wang, L and Li, Y and Wang, Z and Wang, Q},
title = {Arginine kinase McsB and ClpC complex impairs the transition to biofilm formation in Bacillus subtilis.},
journal = {Microbiological research},
volume = {292},
number = {},
pages = {127979},
doi = {10.1016/j.micres.2024.127979},
pmid = {39674004},
issn = {1618-0623},
abstract = {Robust biofilm formation on host niches facilitates beneficial Bacillus to promote plant growth and inhibit plant pathogens. Arginine kinase McsB is involved in bacterial development and stress reaction by phosphorylating proteins for degradation through a ClpC/ClpP protease. Conversely, cognate arginine phosphatase YwlE counteracts the process. Regulatory pathways of biofilm formation have been studied in Bacillus subtilis, of which Spo0A∼P is a master transcriptional regulator, which is transcriptionally activated by itself in biofilm formation. Previous studies have shown that Spo0A∼P transcript regulation controls biofilm formation, where MecA binds ClpC to inhibit Spo0A∼P-dependent transcription without triggering degradation. It remains unclear whether McsB and ClpC regulate biofilm formation together and share a similar non-proteolytic mechanism like MecA/ClpC complex. In this study, we characterized McsB and ClpC as negative regulators of biofilm formation and matrix gene eps expression. Our genetic and morphological evidence further indicates that McsB and ClpC inhibit eps expression by decreasing the spo0A and sinI expression, leading to the release of SinR, a known repressor of eps transcription. Given that the spo0A and sinI expression is transcriptionally activated by Spo0A∼P in biofilm formation, we next demonstrate that McsB interacts with Spo0A directly by bacterial two-hybrid system and Glutathione transferase pull-down experiments. Additionally, we present that McsB forms a complex with ClpC to dampen biofilm formation in vivo. Finally, we show that YwlE acts as a positive regulator of biofilm formation, counteracting the function of McsB. These findings suggest that McsB, ClpC, and YwlE play vital roles in the transition to biofilm formation in Bacillus subtilis, providing new insights into the regulatory mechanisms underlying biofilm development and sharing a similar non-proteolytic mechanism in biofilm formation as MecA/ClpC complex.},
}

@article {pmid39673313,
year = {2024},
author = {Watkins, JD and Lords, CJ and Bradley, AM and Cutler, DR and Sims, RC},
title = {Factorial experiment to identify two-way interactions between temperature, harvesting period, hydraulic retention time, and light intensity that influence the biomass productivity and phosphorus removal efficiency of a microalgae-bacteria biofilm.},
journal = {Water science and technology : a journal of the International Association on Water Pollution Research},
volume = {90},
number = {11},
pages = {2961-2977},
pmid = {39673313},
issn = {0273-1223},
support = {DE-EE0009271//Bioenergy Technologies Office/ ; },
mesh = {*Microalgae/growth & development/metabolism ; *Biomass ; *Phosphorus/metabolism ; *Biofilms/growth & development ; *Temperature ; *Bioreactors ; Light ; Waste Disposal, Fluid/methods ; Time Factors ; Bacteria/metabolism ; },
abstract = {Rotating algae biofilm reactors (RABRs) can reduce energy requirements for wastewater reclamation but require further optimization for implementation at water resource recovery facilities (WRRF). Optimizing RABR operation is challenging because conditions at WRRF change frequently, and disregarding interaction terms related to these changes can produce incorrect conclusions about RABR behavior. This study evaluated the two-way interaction and main effects of four factors on the biomass productivity and phosphorus removal efficiency of a microalgae-bacteria biofilm grown in municipal anaerobic digester centrate, with factor levels and operating conditions selected to mimic a pilot RABR at a WRRF in Utah. Two-way interactions harvesting period*light intensity (LI), harvesting period*temperature, and LI*hydraulic retention time (HRT) had significant effects on biomass productivity: at high temperature and low LI, highest biomass productivity was achieved with a 14-day harvesting period, but at medium temperature and high LI, highest biomass productivity was achieved with a 7-day harvesting period. At high HRT, highest biomass productivity occurred at low LI, but at low HRT, highest biomass productivity occurred at high LI. Phosphorus removal was strongly influenced by LI and occurred most rapidly during the first 2 days HRT, which suggests precipitation contributed significantly to phosphorus removal. These observations provide insight for further RABR optimization.},
}

*Microalgae/growth & development/metabolism
*Biomass
*Phosphorus/metabolism
*Biofilms/growth & development
*Temperature
*Bioreactors
Light
Waste Disposal, Fluid/methods
Time Factors
Bacteria/metabolism

@article {pmid39672057,
year = {2024},
author = {Araujo, TT and Debortolli, ALB and Carvalho, TS and Rodrigues, CMVBF and Dionizio, A and de Souza, BM and Vertuan, M and Ventura, TM and Grizzo, LT and Marchetto, R and Henrique Silva, F and Chiaratti, M and Santos, AC and Alves, LO and Ferro, M and Buzalaf, MAR},
title = {Paving the way for the use of Statherin-Derived Peptide (StN15) to control caries through acquired pellicle and biofilm microbiome engineering: Proof-of-concept in vitro/in vivo studies.},
journal = {Archives of oral biology},
volume = {171},
number = {},
pages = {106159},
doi = {10.1016/j.archoralbio.2024.106159},
pmid = {39672057},
issn = {1879-1506},
abstract = {OBJECTIVE: This proof-of-concept sequence of in vivo/in vitro studies aimed to unveil the role of acquired enamel pellicle (AEP) engineering with statherin-derived peptide (StN15) on the AEP protein profile, enamel biofilm microbiome in vivo and on enamel demineralization in vitro.

DESIGN: In vivo studies, 10 volunteers, in 2 independent experiments (2 days each), rinsed (10 mL,1 min) with: deionized water (negative control) or 1.88 × 10[-5] M StN15. The AEP, formed along 2 h and the biofilm, along 3 h, were collected. AEP was analyzed by quantitative shotgun-label-free proteomics. The enamel biofilm microbiome was evaluated using 16S-rRNA Next Generation Sequencing (NGS). An in vitro model with microcosm biofilm was employed. Bovine enamel samples (n = 72) were treated with 1) Phosphate-Buffer-Solution (PBS), 2) 0.12 %Chlorhexidine, 3) 500ppmNaF; 4) 1.88 × 10[-5]MStN15; 5) 3.76 × 10[-5]MStN15 and 6) 7.52 × 10[-5]MStN15. Biofilm was supplemented with human saliva and McBain saliva and cultivated for 5 days. Resazurin, colony forming units (CFU) and Transversal Microradiography Analysis-(TMR) were performed.

RESULTS: Proteomic results showed several proteins with acid-resistant, calcium-binding, and antimicrobial properties in the StN15 group. The microbiome corroborated these findings, reducing bacteria that are closely related to dental caries in the StN15 group, compared to the PBS. The microcosm biofilm showed that the lowest concentration of StN15 was the most efficient in reducing bacterial activity, CFU and enamel demineralization compared to PBS.

CONCLUSION: StN15 can effectively alter the AEP proteome to inhibit initial bacterial colonization, thereby mitigating enamel demineralization. Future research should explore clinical applications and elucidate the mechanisms underlying the protective effects of StN15.},
}

@article {pmid39671748,
year = {2024},
author = {Mathivanan, K and Zhang, R and Chandirika, JU and Mathimani, T and Wang, C and Duan, J},
title = {Bacterial biofilm-based bioleaching: Sustainable mitigation and potential management of e-waste pollution.},
journal = {Waste management (New York, N.Y.)},
volume = {193},
number = {},
pages = {221-236},
doi = {10.1016/j.wasman.2024.12.010},
pmid = {39671748},
issn = {1879-2456},
abstract = {Significant advances in the electrical and electronic industries have increased the use of electrical and electronic equipment and its environmental emissions. The e-waste landfill disposal has deleterious consequences on human health and environmental sustainability, either directly or indirectly. E-waste containing ferrous and non-ferrous materials can harm the surrounding aquatic and terrestrial environments. Therefore, recycling e-waste and recovering metals from it before landfill disposal is an important part of environmental management. Although various chemical and physical processes are being used predominantly to recover metals from e-waste, the bioleaching process has gained popularity in recent years due to its eco-friendliness and cost-effectiveness. Direct contact between microbes and e-waste is crucial for continuous metal dissolution in the bio-leaching process. Biofilm formation is key for the continuous dissolution of metals from e-waste in contact bioleaching. Critical reviews on microbial activities and their interaction mechanisms on e-waste during metal bioleaching are scarce. Therefore, this review aims to explore the advantages and disadvantages of biofilm formation in contact bioleaching and the practical challenges in regulating them. In this review, sources of e-waste, available metallurgical methods, bioleaching process, and types of bioleaching microbes are summarized. In addition, the significance of biofilm formation in contact bioleaching and the role and correlation between EPS production, cyanide production, and quorum sensing in the biofilm are discussed for continuous metal dissolution. The review reveals that regulation of quorum sensing by exogenous and endogenous processes facilitates biofilm formation, leading to continuous metal dissolution in contact bioleaching.},
}

@article {pmid39670561,
year = {2024},
author = {Gunasekaran, G and Madhubala, MM and Nayanthara, GS and Mahalaxmi, S},
title = {Photodynamic antibacterial evaluation of polydopamine nanoparticle optimised Curcumin Longa against endodontic biofilm-An in-vitro study.},
journal = {Australian endodontic journal : the journal of the Australian Society of Endodontology Inc},
volume = {},
number = {},
pages = {},
doi = {10.1111/aej.12910},
pmid = {39670561},
issn = {1747-4477},
support = {//Indian Endodontic Society/ ; },
abstract = {This study aims to evaluate the effect of antimicrobial photodynamic therapy(aPDT) with polydopamine nanoparticle functionalised with Curcuma longa(nPD-Cur) against root canal biofilm. nPD-Cur was prepared and characterised using Scanning Electron Microscopy(SEM), dynamic light scattering(DLS), Fourier-transform infrared spectroscopy(FTIR) and Ultraviolet visual(UV/Vis) spectrophotometry. Root sections (10 mm length) were obtained from 53 single-rooted human premolars and chemo-mechanically prepared followed by inoculation with E. faecalis. All the specimens were randomly divided into five groups(n = 10) and irrigated (Group 1-Saline; Group 2-2.5% Sodium hypochlorite(NaOCl); Group 3-Cur; Group 4-nPD; and Group 5-nPD-Cur) followed by diode irradiation and analysed for reduction in colony-forming units(CFU)/mL, bacterial viability using Confocal Laser Scanning Microscopy(CLSM) and SEM for biofilm disruption. Results were analysed using one-way ANOVA followed by post hoc Tukey's test for pairwise comparison (p < 0.05). nPD-Cur revealed the characteristic absorption patterns. The antimicrobial potency was highest for NaOCl followed by nPD > Cur-nPD > Cur.},
}

@article {pmid39669779,
year = {2024},
author = {Torkashvand, N and Kamyab, H and Aarabi, P and Shahverdi, AR and Torshizi, MAK and Khoshayand, MR and Sepehrizadeh, Z},
title = {Evaluating the effectiveness and safety of a novel phage cocktail as a biocontrol of Salmonella in biofilm, food products, and broiler chicken.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1505805},
pmid = {39669779},
issn = {1664-302X},
abstract = {Salmonella is a foodborne pathogen of animal and public health significance. Considering the disadvantages of antibiotics or chemical preservatives traditionally used to eliminate this pathogen, attention has shifted, in recent years, toward biocontrol agents such as bacteriophages, used either separately or in combination to prevent food contamination. However, extensive use of phage-based biocontrol agents in the food industry requires further studies to ensure their safety and efficacy. In the present study, we investigated the effectiveness and safety of phage cocktail, a phage cocktail comprising three pre-characterized Salmonella phages (vB_SenS_TUMS_E4, vB_SenS_TUMS_E15 and vB_SenS_TUMS_E19). First, we performed an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide] assay on a human foreskin fibroblast cell line, in which the resulting high cell viability revealed the safety of the phage cocktail. Next, we performed a time-kill assay in which a 4 Log decline in bacterial levels was detected. Additionally, we utilized a colorimetric method to evaluate the anti-biofilm activity of phage cocktail, in which it proved more efficacious compared to the MIC and MBEC levels of the antibiotic control. Then, we assessed the ability of phage cocktail to eradicate Salmonella in different food samples, where it considerably reduced the bacterial count regardless of the temperature (4°C and 25°C). Lastly, we used broiler chickens as an animal model to measure the growth-promoting activity of phage cocktail. Salmonella-infected chickens orally treated with modified phage cocktail demonstrated no mortality and a significant increase in weight gain compared to the untreated group (p ≤ 0.0002). The study presents a novel research evaluating the effectiveness and safety of a phage cocktail as a biocontrol agent against Salmonella in various contexts, including biofilms, food products, and broiler chickens. This multifaceted approach underscores the promising role of phage therapy as a sustainable biocontrol strategy in food safety and public health contexts.},
}

@article {pmid39669429,
year = {2024},
author = {Chiou, JG and Chou, TK and Garcia-Ojalvo, J and Süel, GM},
title = {Intrinsically robust and scalable biofilm segmentation under diverse physical growth conditions.},
journal = {iScience},
volume = {27},
number = {12},
pages = {111386},
pmid = {39669429},
issn = {2589-0042},
abstract = {Developmental patterning is a shared feature across biological systems ranging from vertebrates to bacterial biofilms. While vertebrate patterning benefits from well-controlled homeostatic environments, bacterial biofilms can grow in diverse physical contexts. What mechanisms provide developmental robustness under diverse environments remains an open question. We show that a native clock-and-wavefront mechanism robustly segments biofilms in both solid-air and solid-liquid interfaces. Biofilms grown under these distinct physical conditions differ 4-fold in size yet exhibit robust segmentation. The segmentation pattern scaled with biofilm growth rate in a mathematically predictable manner independent of habitat conditions. We show that scaling arises from the coupling between wavefront speed and biofilm growth rate. In contrast to the complexity of scaling mechanisms in vertebrates, our data suggests that the minimal bacterial clock-and-wavefront mechanism is intrinsically robust and scales in real time. Consequently, bacterial biofilms robustly segment under diverse conditions without requiring cell-to-cell signaling to track system size.},
}

@article {pmid39667852,
year = {2025},
author = {Dishan, A and Ozkaya, Y and Temizkan, MC and Barel, M and Gonulalan, Z},
title = {Candida species covered from traditional cheeses: Characterization of C. albicans regarding virulence factors, biofilm formation, caseinase activity, antifungal resistance and phylogeny.},
journal = {Food microbiology},
volume = {127},
number = {},
pages = {104679},
doi = {10.1016/j.fm.2024.104679},
pmid = {39667852},
issn = {1095-9998},
mesh = {*Cheese/microbiology ; *Biofilms/growth & development ; *Virulence Factors/genetics ; *Drug Resistance, Fungal ; *Phylogeny ; *Antifungal Agents/pharmacology ; *Candida albicans/genetics/drug effects/isolation & purification ; Candida/genetics/drug effects/isolation & purification/classification/pathogenicity ; Turkey ; Microbial Sensitivity Tests ; Fungal Proteins/genetics/metabolism ; },
abstract = {This study has provided characterization data (carriage of virulence, antifungal resistance, caseinase activity, biofilm-forming ability and genotyping) of Candida albicans isolates and the occurrence of Candida species in traditional cheeses collected from Kayseri, Türkiye. Phenotypic (E-test, Congo red agar and microtiter plate tests) and molecular tests (identification, virulence factors, biofilm-formation, antifungal susceptibility) were carried out. The phylogenetic relatedness of C. albicans isolates was obtained by constructing the PCA dendrogram from the mass spectra data. Of 102 samples, 13 (12.7%) were found to be contaminated with C. albicans, 15 (14.7%), 10 (9.8%) and five (4.9%) were found to be contaminated with C. krusei, C. lusitane and C. paraplosis, respectively. While seven (16.2%) of 43 Candida spp. isolates were obtained from cheese collected from villages, 36 (83.7%) belonged to cheeses collected from traditional retail stores. The carriage rate of C. albicans isolates belonging to virulence factors HSP90 and PLB1 genes was 30.7%. ALST1, ALST3, BCR, ECE, andHWP (virulence and biofilm-associated) genes were harbored by 30.7%, 23%, 38.4%, 53.8%, and 38.4% of the 13 isolates. According to the microplate test, eight (61.5%) of 13 isolates had strong biofilm production. ERG11 and FKS1 (antifungal resistance genes) were found in 46.1% and 23% of 13 isolates, respectively. Due to missense mutations, K128T, E266D and V488I amino acid changes were detected for some isolates regarding azole resistance. As a result of the E-test, of the 13 isolates, one (7.6%) was resistant to flucytosine, four (30.7%) were resistant to caspofungin, and nine (69.2%) were resistant to fluconazole. The PCA analysis clustered the studied isolates into two major clades. C. albicans isolates of traditional cheese collected from villages were grouped in the same cluster. Among the C. albicans isolates from village cheese, there were those obtained from the same dairy milk at different times. Samples from the same sales points produced at different dairy farms were also contaminated with C. albicans. Concerning food safety standards applied from farm to fork, in order to prevent these pathogenic agents from contaminating cheeses, attention to the hygiene conditions of the sale points, conscious personnel, prevention of cross contamination will greatly reduce public health threats in addition to the application of animal health control, milking hygiene, pasteurization parameters in traditional cheese production.},
}

*Cheese/microbiology
*Biofilms/growth & development
*Virulence Factors/genetics
*Drug Resistance, Fungal
*Phylogeny
*Antifungal Agents/pharmacology
*Candida albicans/genetics/drug effects/isolation & purification
Candida/genetics/drug effects/isolation & purification/classification/pathogenicity
Turkey
Microbial Sensitivity Tests
Fungal Proteins/genetics/metabolism

@article {pmid39656705,
year = {2024},
author = {Yu, Y and Kim, YH and Cho, WH and Son, BS and Yeo, HJ},
title = {Correction: Biofilm microbiome in extracorporeal membrane oxygenator catheters.},
journal = {PloS one},
volume = {19},
number = {12},
pages = {e0315755},
doi = {10.1371/journal.pone.0315755},
pmid = {39656705},
issn = {1932-6203},
abstract = {[This corrects the article DOI: 10.1371/journal.pone.0257449.].},
}

@article {pmid39667637,
year = {2024},
author = {Terzić, J and Stanković, M and Stefanović, O},
title = {Extracts of Achillea millefolium L. inhibited biofilms and biofilm-related virulence factors of pathogenic bacteria isolated from wounds.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107219},
doi = {10.1016/j.micpath.2024.107219},
pmid = {39667637},
issn = {1096-1208},
abstract = {Biofilm is a surface-attached community of bacterial cells implicated in the pathogenesis of chronic infections and is highly resistant to antibiotics. New alternatives for controlling bacterial infections have been proposed focusing on the therapeutic properties of medicinal plants. Achillea millefollium (Yarrow) is a widespread plant species that is widely used in traditional medicine, especially for wound healing. Therefore, the purpose of this study was to examine the antibiofilm activity of A. millefolium ethanol, acetone, and ethyl acetate extracts on biofilms of Staphylococcus aureus, Proteus spp. and Pseudomonas aeruginosa strains originating from human wounds. Additionally, the effects of the tested extracts on auto-aggregation, cell surface hydrophobicity, and bacterial motility were evaluated. Phytochemical analysis included FT-IR spectroscopy and spectrophotometric quantification of phenolic compound contents was performed. In a test with crystal violet, the extracts strongly inhibited initial cell attachment and biofilm formation, but the effects on mature biofilms were weaker. The effects were dose- and strain-dependent, which was confirmed by fluorescence microscopy. The acetone extract showed the strongest antibiofilm activity. Biofilms of S. aureus S3 and S2 clinical strains were the most susceptible (inhibition of ≥ 76% and ≥ 72% at all tested concentrations, respectively). The highest concentration of total flavonoids was measured in the acetone extract (100.01 ± 3.13 mg RUE/g). Additionally, the extracts reduced bacterial auto-aggregation, swimming and swarming motility of some strains but did not disturb bacterial cell hydrophobicity. These results suggest that A. millefolium extracts have potential roles as new antibiofilm agents against human pathogenic bacteria.},
}

@article {pmid39667627,
year = {2024},
author = {Kao, C and Zhang, Q and Li, J and Liu, J and Li, W and Peng, Y},
title = {Rapid start-up and metabolic evolution of partial denitrification/anammox process by hydroxylamine stimulation: Nitrogen removal performance, biofilm characteristics and microbial community.},
journal = {Bioresource technology},
volume = {418},
number = {},
pages = {131959},
doi = {10.1016/j.biortech.2024.131959},
pmid = {39667627},
issn = {1873-2976},
abstract = {Enhanced nitrogen removal by hydroxylamine (NH2OH) on anammox-related process recently received attention. This study investigated the impact of NH2OH on the partial-denitrification/anammox (PDA) biosystem. Results show that NH2OH (≤10 mg N/L) immediately induced nitrite accumulation and provided sufficient NO2[-] to anammox, achieving a 18.1 ± 4.3 % increase of nitrogen removal efficiency compared to the absence of NH2OH. Long-term exposure to NH2OH accelerated the functional microbial community transformation to PDA. Thauera was highly enriched (6.1 % → 26.9 %) along with Candidatus Brocadia increased in the biofilms, which mainly favor the coupling process of nitrate reduction and anammox. Although the migration mechanism of anammox and denitrifier revealed by CLSM-FISH alleviates the adverse effects of NH2OH, the anammox was inhibited when NH2OH exceeding 15 mg N/L through destroying the inner reduction of NO2[-]. These results suggested appropriate NH2OH addition favors the synergy between denitrifying and anammox bacteria, providing a promising option for wastewater treatment.},
}

@article {pmid39667480,
year = {2024},
author = {Zhu, Q and Du, Y and Zheng, Y and Hu, Z and Liu, Z and Hu, J and Hou, H},
title = {Quorum quenching inhibits the formation and electroactivity of electrogenic biofilm by weakening intracellular c-di-GMP and extracellular AHL-mediated signal communication.},
journal = {Environmental research},
volume = {266},
number = {},
pages = {120604},
doi = {10.1016/j.envres.2024.120604},
pmid = {39667480},
issn = {1096-0953},
abstract = {Electrogenic biofilm formation has been shown to be induced by intracellular c-di-GMP signaling and extracellular quorum sensing, but their interactions have been rarely explored. This study explored the effects of quorum quenching (induced by adding acylase) on electrogenic biofilm development and its underlying mechanisms. Quorum quenching impaired the electricity generation and electroactivity of electrogenic biofilms as indicated by dye decolorization rate. It significantly decreased the proportion of typical exoelectrogen Geobacter from 62.0% to 36.5% after 90 days of operation, and enriched some other functional genera (e.g., Dysgonomonas and Sphaerochaeta) to ensure normal physiological function. Moreover, metagenomic analysis revealed that the addition of acylase weakened the potential of chemical communication, as indicated by the decrease in the abundance of genes encoding the production of AHL and c-di-GMP, and the increase in the abundance of aiiA and pvdQ genes (encoding quorum quenching) and cdgC gene (responsible for c-di-GMP breakdown). Functional contribution analysis indicated that Geobacter was a major contributor to hdtS gene (encoding AHL synthesis). These findings demonstrated that quorum quenching adversely impaired not only quorum sensing but also intracellular c-di-GMP signaling, ultimately inhibiting the development of biofilm. This work lays the foundation for regulating electrogenic biofilm development and improving the performance of microbial electrochemical system using signal communication strategy.},
}

@article {pmid39667149,
year = {2024},
author = {Datta, DK and Paramban, S and Yazdani, H and Brown, SP and Fischer, S and Salehi, M},
title = {Influence of biofilm and calcium carbonate scaling on lead transport in plastic potable water pipes: A laboratory and molecular dynamics study.},
journal = {Journal of hazardous materials},
volume = {485},
number = {},
pages = {136831},
doi = {10.1016/j.jhazmat.2024.136831},
pmid = {39667149},
issn = {1873-3336},
abstract = {This study investigated lead (Pb) transport through new, biofilm-laden, and calcium carbonate-scaled crosslinked polyethylene (PEX-A) and high-density polyethylene (HDPE) potable water pipes. The research focused on Pb accumulation through short-term exposure incidents (6 h) and Pb release for a longer duration (5 d). A mechanistic investigation of the surface morphology variations of plastic pipes following biofilm and scale formation has been conducted. The nanoscale surface asperities in new PEX-A pipes and microscale roughness features in new HDPE pipes supported the differences in biofilm abundance, scale formation, and metal uptake results between these two pipes. Biomass analysis and dissolved organic matter (DOM) quantification using three-dimensional excitation emission spectroscopy revealed a greater release of biofilm biomass during the Pb accumulation and release experiments from biofilm-laden HDPE pipes. Both biofilm-laden plastic pipes accumulated a significantly greater level of Pb compared to the new and scaled pipes. However, scaled pipes showed the highest Pb release, while biofilm-laden pipes released the least. Additionally, investigation of Pb[2+] exchange from the pipe surface in the presence of Ca[2+] in the solution indicated that divalent cations in water can trigger further Pb release from the pipe surface. Furthermore, the molecular dynamics simulation provided valuable insights into the interaction between different pipe surfaces with Pb with respect to affinity and binding energy.},
}

@article {pmid39665083,
year = {2024},
author = {De Jesus, R and Iqbal, S and Mundra, S and AlKendi, R},
title = {Heterogenous bioluminescence patterns, cell viability, and biofilm formation of Photobacterium leiognathi strains exposed to ground microplastics.},
journal = {Frontiers in toxicology},
volume = {6},
number = {},
pages = {1479549},
pmid = {39665083},
issn = {2673-3080},
abstract = {Microplastics (MPs) have been detected in various aquatic environments and negatively affect organisms, including marine luminous bacteria. This study investigated the differences in bioluminescence patterns, cell viability, and biofilm formation of Photobacterium leiognathi strains (LB01 and LB09) when exposed to various concentrations of ground microplastics (GMPs; 0.25%, 0.50%, 1%, or 2% [w/v] per mL) at 22°C or 30°C for 3.1 days (75 h) and 7 days. The strains exhibited heterogenous responses, including variable bioluminescence patterns, cell viability, and biofilm formation, due to the GMPs having effects such as hormesis and bioluminescence quenching. Moreover, the bioluminescence and cell viability differed between the two strains, possibly involving distinct cellular mechanisms, suggesting that GMPs affect factors that influence quorum sensing. Furthermore, the biofilm formation of LB01 and LB09 was observed following exposure to GMPs. Both strains showed increased biofilm formation at higher GMP concentrations (1% and 2%) after 3.1 days at 30°C and 22°C. However, in the 7-day experiment, LB01 significantly (p < 0.05) increased biofilms at 22°C, while LB09 significantly (p < 0.05) produced biofilms at 30°C. These findings highlight the strain-specific responses of Phb. leiognathi to MP pollutants. Therefore, this study underscores the importance of evaluating MPs as environmental stressors on marine microorganisms and their role in the ecophysiological repercussions of plastic pollution in aquatic environments.},
}

@article {pmid39664965,
year = {2024},
author = {Qiu, Z and Ran, J and Yang, Y and Wang, Y and Zeng, Y and Jiang, Y and Hu, Z and Zeng, Z and Peng, J},
title = {OmpH is Involved in the Decrease of Acinetobacter baumannii Biofilm by the Antimicrobial Peptide Cec4.},
journal = {Drug design, development and therapy},
volume = {18},
number = {},
pages = {5795-5810},
pmid = {39664965},
issn = {1177-8881},
mesh = {*Biofilms/drug effects ; *Acinetobacter baumannii/drug effects ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Microbial Sensitivity Tests ; Antimicrobial Peptides/pharmacology/chemistry ; Bacterial Outer Membrane Proteins/genetics/metabolism ; },
abstract = {PURPOSE: The emergence of carbapenem-resistant Acinetobacter baumannii (CRAB) poses great difficulties in clinical treatment, and has been listed by the World Health Organization as a class of pathogens in urgent need of new antibiotic development. In our previous report, the novel antimicrobial peptide Cec4 showed great potential in decreasing the clinical CRAB biofilm, but its mechanism of action is still illusive. Therefore, in order to evaluate the clinical therapeutic potential of Cec4, it is necessary to explore the mechanism of how Cec4 decreases mature biofilms.

METHODS: Key genes involved in the removal of CRAB biofilms by Cec4 were analyzed using transcriptomics. Based on the results of the bioinformatics analysis, the CRISPR-Cas9 method was used to construct the deletion strain of the key gene. The pYMAb2 plasmid was used for the complementation strain construction. Finally, the roles of key genes in biofilm removal by Cec4 were determined by crystal violet staining, podocyte staining, laser confocal imaging, and MBC and MBEC50.

RESULTS: Combined with transcriptome analysis, we hypothesized that OmpH is a key gene involved in the removal of CRAB biofilms by Cec4. Deletion of the OmpH gene did not affect A. baumannii growth, but decreased A. baumannii capsule thickness, increasing biofilm production, and made biofilm-state A. baumannii more sensitive to Cec4.

CONCLUSION: Cec4 decreases biofilms formed by CRAB targeting OmpH. Deletion of the OmpH gene results in an increase in biofilms and greater sensitivity to Cec4, which enhances the removal of A. baumannii biofilms by Cec4.},
}

*Biofilms/drug effects
*Acinetobacter baumannii/drug effects
*Anti-Bacterial Agents/pharmacology/chemistry
*Microbial Sensitivity Tests
Antimicrobial Peptides/pharmacology/chemistry
Bacterial Outer Membrane Proteins/genetics/metabolism

@article {pmid39664834,
year = {2024},
author = {Bhamare, SA and Dahake, PT and Kale, YJ and Dadpe, MV and Kendre, SB},
title = {Effect of Herbal Extract of Spilanthes acmella and Cinnamon Oil on Enterococcus faecalis Biofilm Eradication: An In Vitro Study.},
journal = {International journal of clinical pediatric dentistry},
volume = {17},
number = {9},
pages = {1004-1013},
pmid = {39664834},
issn = {0974-7052},
abstract = {INTRODUCTION: Enterococcus faecalis has a pathogenic role in failed endodontic treatments. The study aimed to assess the efficiency of Spilanthes acmella (SA) and cinnamon oil (CO) extract on E. faecalis biofilm eradication.

MATERIALS AND METHODS: The antibacterial efficacy of SA and CO against E. faecalis was assessed by the tests of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and further, the interaction with agents was evaluated at different time intervals by a time-kill assay. The inhibition efficacy of both agents was determined by biofilm adhesion reduction crystal violet assay.

RESULTS: The MIC of SA was 25 μg/mL, and for CO, it was 12.5 μg/mL. The time-kill assay revealed that antibacterial efficacy was identified till 36 hours by both the test materials. The mean biofilm reduction at 25 µg/mL of calcium hydroxide [Ca(OH)2], SA, and CO was 1.53 ± 0.05, 1.83 ± 1.57, and 2.06 ± 0.05, respectively.

CONCLUSION: SA and CO demonstrated promising antibacterial efficacy against E. faecalis and CO presented significant eradication of biofilms compared to SA.

HOW TO CITE THIS ARTICLE: Bhamare SA, Dahake PT, Kale YJ, et al. Effect of Herbal Extract of Spilanthes acmella and Cinnamon Oil on Enterococcus faecalis Biofilm Eradication: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(9):1004-1013.},
}

@article {pmid39664828,
year = {2024},
author = {Fernandes, RM and Kumar, S and Suvarna, R and Shastry, RP and Sargod, S and Bhat, SS and Manoj, K},
title = {Surface Prereacted Glass Ionomer Varnish as a Multifaceted Anticaries Agent: Investigating its Inhibitory Effects on Demineralization and Biofilm Formation on Primary Tooth Enamel.},
journal = {International journal of clinical pediatric dentistry},
volume = {17},
number = {9},
pages = {1049-1056},
pmid = {39664828},
issn = {0974-7052},
abstract = {BACKGROUND: Dental caries remains a significant oral health concern, particularly in young children. With an increasing interest in preventive strategies, pediatric and preventive dentistry research is now more focused on developing newer materials and techniques to coat the primary teeth to prevent the onset of new carious lesions. While traditional preventive measures such as fluoride application and sealants have been effective in reducing caries incidence, there is still a need for innovative approaches.

AIM: To evaluate the effectiveness of surface prereacted glass ionomer (S-PRG) light-cured varnish in inhibiting demineralization of primary teeth enamel.

MATERIALS AND METHODS: In this study, primary teeth samples were randomly divided into two groups: the control group received no coating, while the test group received an S-PRG filler coat. The samples were allowed to demineralize, and various analyses, including Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDX), and Vickers microhardness analysis, were conducted. Additionally, biofilms of Streptococcus mutans and Enterococcus faecalis were developed on solid surfaces such as microtiter plates, glass, and dentures, and the quantity of bacterial biofilm was measured using crystal violet assay and fluorescence microscopy.

RESULTS: The study results showed that the primary teeth samples in both groups had a significantly greater calcium content than the controls. The S-PRG group demonstrated a significant reduction in the development of biofilms of S. mutans and E. faecalis, as well as bacterial attachment to glass and denture surfaces compared to the control group, as indicated by crystal violet assay and fluorescence microscopy.

CONCLUSION: The findings of this study suggest that S-PRG filler-containing coating materials have the potential to prevent demineralization and inhibit S. mutans and E. faecalis biofilm formation on primary tooth enamel.

CLINICAL SIGNIFICANCE: These results are promising and may have implications for the prevention of dental caries in young children.

HOW TO CITE THIS ARTICLE: Fernandes RM, Kumar S, Suvarna R, et al. Surface Prereacted Glass Ionomer Varnish as a Multifaceted Anticaries Agent: Investigating its Inhibitory Effects on Demineralization and Biofilm Formation on Primary Tooth Enamel. Int J Clin Pediatr Dent 2024;17(9):1049-1056.},
}

@article {pmid39663366,
year = {2024},
author = {Zhao, Q and Wang, R and Song, Y and Lu, J and Zhou, B and Song, F and Zhang, L and Huang, Q and Gong, J and Lei, J and Dong, S and Gu, Q and Borriss, R and Gao, X and Wu, H},
title = {Pyoluteorin-deficient Pseudomonas protegens improves cooperation with Bacillus velezensis, biofilm formation, co-colonizing, and reshapes rhizosphere microbiome.},
journal = {NPJ biofilms and microbiomes},
volume = {10},
number = {1},
pages = {145},
pmid = {39663366},
issn = {2055-5008},
support = {31972325, 32172490//National Natural Science Foundation of China (National Science Foundation of China)/ ; },
mesh = {*Bacillus/genetics/metabolism/physiology ; *Pseudomonas/genetics/metabolism/physiology ; *Rhizosphere ; *Biofilms/growth & development ; *Solanum lycopersicum/microbiology ; *Phenols/metabolism ; Plant Roots/microbiology ; Pyrroles/metabolism ; Microbiota ; Plant Diseases/microbiology ; Soil Microbiology ; Microbial Interactions ; },
abstract = {Plant-beneficial Pseudomonas and Bacillus have been extensively studied and applied in biocontrol of plant diseases. However, there is less known about their interaction within two-strain synthetic communities (SynCom). Our study revealed that Pseudomonas protegens Pf-5 inhibits the growth of several Bacillus species, including Bacillus velezensis. We established a two-strain combination of Pf-5 and DMW1 to elucidate the interaction. In this combination, pyoluteorin conferred the competitive advantage of Pf-5. Noteworthy, pyoluteorin-deficient Pf-5 cooperated with DMW1 in biofilm formation, production of metabolites, root colonization, tomato bacterial wilt disease control, as well as in cooperation with beneficial bacteria in tomato rhizosphere, such as Bacillus spp. RNA-seq analysis and RT-qPCR also proved the pyoluteorin-deficient Pf-5 mutant improved cell motility and metabolite production. This study suggests that the cooperative effect of Bacillus-Pseudomonas consortia depends on the balance of pyoluteorin. Our finding needs to be considered in developing efficient SynCom in sustainable agriculture.},
}

*Bacillus/genetics/metabolism/physiology
*Pseudomonas/genetics/metabolism/physiology
*Rhizosphere
*Biofilms/growth & development
*Solanum lycopersicum/microbiology
*Phenols/metabolism
Plant Roots/microbiology
Pyrroles/metabolism
Microbiota
Plant Diseases/microbiology
Soil Microbiology
Microbial Interactions

@article {pmid39660862,
year = {2024},
author = {Sangha, JS and Gogulancea, V and Curtis, TP and Jakubovics, NS and Barrett, P and Metris, A and Ofiţeru, ID},
title = {Advancing dental biofilm models: the integral role of pH in predicting S. mutans colonization.},
journal = {mSphere},
volume = {},
number = {},
pages = {e0074324},
doi = {10.1128/msphere.00743-24},
pmid = {39660862},
issn = {2379-5042},
abstract = {Mathematical models can provide insights into complex interactions and dynamics within microbial communities to complement and extend experimental laboratory approaches. For dental biofilms, they can give a basis for evaluating biofilm growth or the transition from health to disease. We have developed mathematical models to simulate the transition toward a cariogenic microbial biofilm, modeled as the overgrowth of Streptococcus mutans within a five-species dental community. This work builds on experimental data from a continuous flow reactor with hydroxyapatite coupons for biofilm growth, in a chemically defined medium with varying concentrations of glucose and lactic acid. The biofilms formed on the coupons were simulated using individual-based models (IbMs), with bacterial growth modeled using experimentally measured kinetic parameters. The IbM assumes that the maximum theoretical growth yield for biomass is dependent on the local concentration of reactants and products, while the growth rates were described using traditional Monod equations. We have simulated all the conditions studied experimentally, considering different initial relative abundance of the five species, and also different initial clustering in the biofilm. The simulation results only reproduced the experimental dominance of S. mutans at high glucose concentration after we considered the species-specific effect of pH on growth rates. This highlights the significance of the aciduric property of S. mutans in the development of caries. Our study demonstrates the potential of combining in vitro and in silico studies to gain a new understanding of the factors that influence dental biofilm dynamics.IMPORTANCEWe have developed in silico models able to reproduce the relative abundance measured in vitro in the synthetic dental biofilm communities growing in a chemically defined medium. The advantage of this combination of in vitro and in silico models is that we can study the influence of one parameter at a time and aim for direct validation. Our work demonstrates the utility of individual-based models for simulating diverse conditions affecting dental biofilm scenarios, such as the frequency of glucose intake, sucrose pulsing, or integration of pathogenic or probiotic species. Although in silico models are reductionist approaches, they have the advantage of not being limited in the scenarios they can test by the ethical consideration of an in vivo system, thus significantly contributing to dental biofilm research.},
}

@article {pmid39659667,
year = {2024},
author = {Kendra, S and Czucz Varga, J and Gaálová-Radochová, B and Bujdáková, H},
title = {Practical application of PMA-qPCR assay for determination of viable cells of inter-species biofilm of Candida albicans-Staphylococcus aureus.},
journal = {Biology methods & protocols},
volume = {9},
number = {1},
pages = {bpae081},
pmid = {39659667},
issn = {2396-8923},
abstract = {Determining the number of viable cells by calculating colony-forming units is time-consuming. The evaluation of mixed biofilms consisting of different species is particularly problematic. Therefore, the aim of this study was to optimize a molecular method-propidium monoazide quantitative polymerase chain reaction (PMA-qPCR)-for accurate and consistent differentiation between living and dead cells. In the practical experimental example, the number of genome copies representing living cells was determined in a mixed biofilm of Candida albicans-Staphylococcus aureus inhibited by photodynamic inactivation. Optimal conditions such as PMA concentration and the duration of light exposure, the optimization of DNA isolation from the mixed biofilm and standardization of PMA-qPCR parameters were tested prior to the main experiment. The genome copy number was calculated based on the known amount of genomic DNA in the qPCR and the genome size of the respective microorganism. The results showed that photodynamic inactivation in the presence of 1 mM methylene blue decreased the total genome copy number from 1.65 × 10[8] to 3.19 × 10[7], and from 4.39 × 10[7] to 1.91 × 10[7] for S. aureus and C. albicans (P < 0.01), respectively. The main disadvantage is the overestimation of the number of living cells represented by genome copy numbers. Such cells are unable to reproduce and grow (no vitality) and are continuously dying. On the other hand, PMA-qPCR determines the copy numbers of all microbial species, including a mix of eukaryotic yeasts and prokaryotic bacteria in a biofilm in one step, which is a great advantage.},
}

@article {pmid39657894,
year = {2024},
author = {Wang, P and Zeng, Y and Liu, J and Wang, L and Yang, M and Zhou, J},
title = {Antimicrobial and Anti-Biofilm Effects of Dihydroartemisinin-loaded chitosan nanoparticles Against Methicillin-Resistant Staphylococcus aureus.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107208},
doi = {10.1016/j.micpath.2024.107208},
pmid = {39657894},
issn = {1096-1208},
abstract = {The formation of biofilms enhances bacterial antibiotic resistance, posing significant challenges to clinical treatment. Methicillin-resistant Staphylococcus aureus (MRSA) is a primary pathogen in biofilm-associated infections. Its high antibiotic resistance and incidence rates make it a major clinical challenge, underscoring the urgent need for novel therapeutic strategies. Building on previous research, this study employs nanotechnology to fabricate dihydroartemisinin-chitosan nanoparticles (DHA-CS NPs) and, for the first time, applies them to the treatment of MRSA biofilm infections. Their antibacterial and anti-biofilm activities are evaluated, and their potential mechanisms of action are preliminarily explored. The results demonstrated that DHA-CS NPs exhibited a minimum inhibitory concentration (MIC) of of 15 μg/mL, and a minimum bactericidal concentration (MBC) of 30 μg/mL. At 15 μg/mL, DHA-CS NPs significantly inhibited MRSA biofilm formation (P < 0.001),while at 7.5 μg/mL, they disperse 67.4 ± 3.77% of preformed biofilms (P <0.001). Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) confirmed the disruption of MRSA biofilms., Mechanistic studies, including phenol-sulfuric acid assays, static biofilm microtiter plate assays, and RT-qPCR, reveal that DHA-CS NPs inhibit the synthesis of extracellular polymeric substances (EPS), suppress the release of extracellular DNA (eDNA), and downregulate key biofilm-related genes (icaA, sarA, cidA, and agrA). These findings suggest that DHA-CS NPs hold significant promise for inhibiting and eradicating MRSA biofilms, providing a theoretical basis for developing novel antibiofilm therapies.},
}

@article {pmid39657876,
year = {2024},
author = {Harkai, Á and Beck, YK and Tory, A and Mészáros, T},
title = {Selection of streptococcal glucan-binding protein C specific DNA aptamers to inhibit biofilm formation.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {138579},
doi = {10.1016/j.ijbiomac.2024.138579},
pmid = {39657876},
issn = {1879-0003},
abstract = {Streptococcus mutans is a commensal oral bacterium, yet its capacity for extensive biofilm formation is a major contributor to dental caries. This study presents a novel biofilm inhibition strategy by targeting GbpC, a cornerstone protein in S. mutans biofilm architecture, with specific DNA aptamers. Using SELEX (Systematic Evolution of Ligands by EXponential enrichment), we selectively targeted the extracellular domain of GbpC while incorporating structurally similar antigen I/II protein and a GbpC-deficient S. mutans strain as counter-targets to ensure high specificity. Aptamer selection was further refined through a panning method that combined primer-blocked asymmetric PCR with AlphaScreen technology. Detailed binding analyses via biolayer interferometry and microscale thermophoresis confirmed the interaction between top aptamer candidates and GbpC. Functional assays demonstrated that two lead aptamers evidently inhibited biofilm formation in wild-type S. mutans without affecting the GbpC-deficient strain, highlighting the aptamers' specificity. These results confirm that the selected aptamers retain specificity even in the complex bacterial culture matrix, validating the efficacy of our selection approach. Notably, these aptamers represent the first instance of using DNA aptamers to inhibit S. mutans biofilm formation by disrupting glucan binding. These aptamers hold promise as lead molecules for the development of biofilm-targeting therapies in dental care.},
}

@article {pmid39654786,
year = {2024},
author = {Aghmiyuni, ZF and Ahmadi, MH and Saderi, H},
title = {Relationship between the strength of biofilm production and the presence of pvl and mecA genes in Staphylococcus aureus isolated from skin and soft tissue infections.},
journal = {Heliyon},
volume = {10},
number = {23},
pages = {e40524},
pmid = {39654786},
issn = {2405-8440},
abstract = {This research sought to investigate the association between the occurrence of the pvl and mecA genes and the strength of biofilm formation, as well as to assess the efficacy of vancomycin and ceftaroline against Staphylococcus aureus strains obtained from skin and soft tissue infections (SSTIs). A total of 134 S. aureus isolates were collected from SSTI patients and identified through standard microbiological techniques. Vancomycin and ceftaroline susceptibility testing were performed using the agar dilution and disc diffusion methods, respectively. PCR analysis was conducted to identify the nuc, mecA, and pvl genes. Biofilm production was measured using the tissue culture plate method. Methicillin-resistant S. aureus (MRSA) represented 58.2 % of the isolates. All isolates displayed biofilm-forming capability, with 10.4 % classified as high-grade biofilm producers, 85.7 % of which were positive for the mecA gene (P = 0.02). 16.4 % of the isolates had pvl gene and 59 % of PVL-positive strains identified as MRSA. Most of the low-grade biofilm producers had the pvl gene (P = 0.03). Vancomycin susceptibility was observed in 98.5 % of isolates, with an MIC50 of 1 μg/mL in 51.4 % of cases. Among MRSA strains, 1.4 % exhibited intermediate resistance to vancomycin, with MICs between 4 and 8 μg/mL. No resistance to ceftaroline was found. The results demonstrate a significant association between biofilm production strength and the occurrence of the mecA and pvl genes; mecA correlated with increased biofilm production, while pvl was associated with lower biofilm levels. These findings offer valuable insights for future studies, suggesting that ceftaroline could be an effective alternative to vancomycin for treating MRSA-related SSTIs, particularly given the increasing resistance to vancomycin.},
}

@article {pmid39654682,
year = {2024},
author = {Nandanwar, N and Gu, G and Gibson, JE and Neely, MN},
title = {Polymicrobial interactions influence Mycobacterium abscessus co-existence and biofilm forming capabilities.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1484510},
pmid = {39654682},
issn = {1664-302X},
abstract = {The lungs of patients with cystic fibrosis (CF) are vulnerable to persistent polymicrobial colonization by bacterial pathogens including Pseudomonas aeruginosa, Staphylococcus aureus, and the non-tuberculous mycobacterium (NTM) Mycobacterium abscessus. The polymicrobial milieu within the CF lung impacts individual species fitness, influences biofilm-forming capabilities, pathogenicity, production of virulence factors and even antimicrobial responses, all potentially compromising therapeutic success. Interaction studies among these CF pathogens are very limited, especially studies on the influences of P. aeruginosa and S. aureus on M. abscessus co-existence and virulence. Based on the little known thus far about coinfection of these pathogens, we hypothesize that the co-existence of P. aeruginosa and S. aureus alters M. abscessus virulence and phenotypic characteristics. We evaluated the direct (co-culture) and indirect (using supernatant) effects of P. aeruginosa and S. aureus on M. abscessus growth rate, biofilm formation, macrophage internalization and glycopeptidolipids (GPL) expression. Our observations indicate that P. aeruginosa and S. aureus exert a competitive behavior toward M. abscessus during direct contact or indirect interaction in-vitro, probably as is the case of polymicrobial infections in the lungs of patients with CF. This is the first report that demonstrates S. aureus inhibitory effects on M. abscessus growth and biofilm forming capabilities. Collectively, co-culture studies enhance our understanding of polymicrobial interactions during coinfection and can guide to establish better management of coinfections and treatment strategies for M. abscessus.},
}

@article {pmid39653175,
year = {2024},
author = {Wei, Y and Xia, W and Qian, Y and Rong, C and Ye, M and Yujie, C and Kikuchi, J and Li, YY},
title = {Revealing microbial compatibility of partial nitritation/Anammox biofilm from sidestream to mainstream applications: Origins, dynamics, and interrelationships.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {131963},
doi = {10.1016/j.biortech.2024.131963},
pmid = {39653175},
issn = {1873-2976},
abstract = {Biofilms offer a solution to the challenge of low biomass retention faced in mainstream partial nitritation/Anammox (PN/A) applications. In this study, a one-stage PN/A reactor derived from initial granular sludge was successfully transformed into a biofilm system using shedding carriers. Environmental stressors, such as ammonium nitrogen concentration and organic matter, significantly affected the competitive dynamics and dominant species composition between Ca. Kuenenia and Ca. Brocadia. Under approximately 500 mg/L NH4[+]-N, Ca. Brocadia emerged as the dominant anammox bacteria species, but was subsequently replaced by Ca. Kuenenia in the presence of approximately 54 mg COD/L CH3COONa. Moreover, Chloroflexi species on the original biofilm exhibited an associated relationship with the growth of Ca. Kuenenia in new biofilm. The biofilm assembly and microbial community migration uniquely reveal the microbial niche dynamics. This study provides valuable insights for PN/A biofilm applications facing diverse challenges of environmental stresses in the transition from sidestream to mainstream.},
}

@article {pmid39651958,
year = {2024},
author = {Werlang, CA and Sahoo, JK and Cárcarmo-Oyarce, G and Stevens, C and Uzun, D and Putnik, R and Hasturk, O and Choi, J and Kaplan, DL and Ribbeck, K},
title = {Selective Biofilm Inhibition through Mucin-Inspired Engineering of Silk Glycopolymers.},
journal = {Journal of the American Chemical Society},
volume = {},
number = {},
pages = {},
doi = {10.1021/jacs.4c12945},
pmid = {39651958},
issn = {1520-5126},
abstract = {Mucins are key components of innate immune defense and possess remarkable abilities to manage pathogenic microbes while supporting beneficial ones and maintaining microbial homeostasis at mucosal surfaces. Their unique properties have garnered significant interest in developing mucin-inspired materials as novel therapeutic strategies for selectively controlling pathogens without disrupting the overall microbial ecology. However, natural mucin production is challenging to scale, driving the need for simpler materials that reproduce mucin's bioactivity. In this work, we generated silk-based glycopolymers with different monosaccharides (GalNAc, GlcNAc, NeuNAc, GlcN, and GalN) and different grafting densities. Using the oral cavity as a model system, we treated in vitro cultures of pathogenic Streptococcus mutans and commensal Streptococcus sanguinis with our glycopolymers, finding that silk-tethered GalNAc uniquely prevented biofilm formation without affecting overall bacterial growth of either species. This relatively simple material reproduced mucin's virulence-neutralizing effects while maintaining biocompatibility. These mucin-inspired materials represent a valuable tool for preventing infection-related harm and offer a strategy for the domestication of pathogens in other environments.},
}

@article {pmid39649128,
year = {2024},
author = {Jones, L and Salta, M and Skovhus, TL and Thomas, K and Illson, T and Wharton, J and Webb, J},
title = {Dual anaerobic reactor model to study biofilm and microbiologically influenced corrosion interactions on carbon steel.},
journal = {Npj Materials degradation},
volume = {8},
number = {1},
pages = {125},
pmid = {39649128},
issn = {2397-2106},
abstract = {Continual challenges due to microbial corrosion are faced by the maritime, offshore renewable and energy sectors. Understanding the biofilm and microbiologically influenced corrosion interaction is hindered by the lack of robust and reproducible physical models that reflect operating environments. A novel dual anaerobic biofilm reactor, using a complex microbial consortium sampled from marine littoral sediment, allowed the electrochemical performance of UNS G10180 carbon steel to be studied simultaneously in anaerobic abiotic and biotic artificial seawater. Critically, DNA extraction and 16S rRNA amplicon sequencing demonstrated the principal biofilm activity was due to electroactive bacteria, specifically sulfate-reducing and iron-reducing bacteria.},
}

@article {pmid39648406,
year = {2024},
author = {Geng, F and Liu, J and Liu, J and Lu, Z and Pan, Y},
title = {Recent progress in understanding the role of bacterial extracellular DNA: focus on dental biofilm.},
journal = {Critical reviews in microbiology},
volume = {},
number = {},
pages = {1-19},
doi = {10.1080/1040841X.2024.2438117},
pmid = {39648406},
issn = {1549-7828},
abstract = {Dental biofilm is a highly complicated and dynamic structure comprising not only microbial communities but also the surrounding matrix of extracellular polymeric substances (EPS), including polysaccharides, proteins, extracellular DNA (eDNA) and other biopolymers. In recent years, the important role of bacterial eDNA in dental biofilms has gradually attracted attention. In this review, we present recent studies on the presence, dynamic conformation and release of oral bacterial eDNA. Moreover, updated information on functions associated with oral bacterial eDNA in biofilm formation, antibiotic resistance, activation of the immune system and immune evasion is highlighted. Finally, we summarize the role of oral bacterial eDNA as a promising target for the treatment of oral diseases. Increasing insight into the versatile roles of bacterial eDNA in dental biofilms will facilitate the prevention and treatment of biofilm-induced oral infections.},
}

@article {pmid39647771,
year = {2024},
author = {Chen, R and Xu, R and Huang, J and Zhu, X and Tang, Y and Zhang, Y},
title = {N-acyl-homoserine-lactones as a critical factor for biofilm formation during the initial adhesion stage in drinking water distribution systems.},
journal = {Environmental pollution (Barking, Essex : 1987)},
volume = {},
number = {},
pages = {125489},
doi = {10.1016/j.envpol.2024.125489},
pmid = {39647771},
issn = {1873-6424},
abstract = {The N-acyl-homoserine-lactone (AHLs)-mediated quorum sensing (QS) system is crucial for the coordination of microbial behaviors within communities. However, the levels of AHLs in biofilms in drinking water distribution systems (DWDSs) and their impact on biofilm formation remain poorly understood. Herein, we simulated DWDSs via biofilm reactors to explore the presence and influence of AHLs during the initial stages of biofilm formation on pipe walls. Glass, polypropylene random copolymer (PP-R) and stainless steel (SS) were used as the coupon materials and the three parallel experimental groups were set up and named accordingly. The glass material is considered to form biofilms only minimally and is therefore used as a negative control. By day 30, the concentration of AHLs in biofilm phase in both PP-R group and SS group reached 1200-1800 ng/L. The predominant AHLs were C6-HSL, C8-HSL, and C10-HSL, with a significant positive correlation between AHLs and biofilm biomass. Metagenomic analysis revealed that microbes exhibiting significant differences among the three groups all demonstrated notable correlations with AHLs. Subsequent analysis of QS genes revealed that the genes associated with AHLs biosynthesis and QS receptors were more abundant in the PP-R and SS groups with biofilm formation. Additionally, we analyzed the abundance of genes related to cell motility, transmembrane transport, tricarboxylic acid cycle, and genetic information synthesis. The co-occurrence network indicates that these processes exhibit a strong correlation with QS genes. This study demonstrates the pivotal role of AHLs in microbial communication during the initial stages of biofilm formation in DWDSs and indicates that the regulatory pathways and mechanisms of AHLs may vary under different environmental conditions.},
}

@article {pmid39647662,
year = {2024},
author = {Kato, H and Yoshida, H and Saito, M and Hashizume-Takizawa, T and Negishi, S and Senpuku, H},
title = {Assessment of biofilm formation on ceramic, metal, and plastic brackets in orthodontic materials by new method using renG-expressing Streptococcus mutans.},
journal = {Journal of oral biosciences},
volume = {},
number = {},
pages = {100594},
doi = {10.1016/j.job.2024.100594},
pmid = {39647662},
issn = {1880-3865},
abstract = {OBJECTIVE: Oral biofilm has a high acid-producing capacity, increases the risk of enamel demineralization around brackets, and has been identified as a problem in orthodontic treatment. Here, we assessed the risk of biofilm formation by Streptococcus mutans, which is associated with the development of white spot lesions (WSL) on tooth surfaces, using multibracket devices.

METHODS: Various types of brackets were used for the biofilm formation assay with S. mutans coated with human saliva, immersed in renG-expressing S. mutans UA159 (strain with the luciferase gene inserted), and incubated overnight at 37°C under aerobic conditions containing 5% CO2. The biofilm was washed twice with phosphate-buffered saline (PBS), and 200 μL of luciferin dissolved in PBS was added to each well. The mixture was light shielded and allowed to react for 20 min. Luminescence was measured as the amount of biofilm formed by live cells on the bracket surfaces using an optical emission spectrophotometer.

RESULTS: Biofilm formation was greater in plastic brackets than in ceramic and metal brackets in a number-dependent manner. However, biofilm formation was inhibited as the plastic bracket was coated with saliva.

CONCLUSION: For preventive treatments of WSL onset during orthodontic treatment, orthodontists should carefully select and customize brackets based on patient needs, goals, and biomechanical principles. This study developed a new measurement method using renG-expressing S. mutans UA159 to accurately assess active biofilm formation on bracket surfaces.},
}

@article {pmid39645169,
year = {2024},
author = {da Silva, ARP and Costa, MDS and Araújo, NJS and de Freitas, TS and Paulo, CLR and de Alencar, MAS and Barbosa-Filho, JM and Andrade-Pinheiro, JC and Coutinho, HDM},
title = {Evaluation of inhibition and eradication of bacterial biofilm by solasodin.},
journal = {The Journal of steroid biochemistry and molecular biology},
volume = {},
number = {},
pages = {106654},
doi = {10.1016/j.jsbmb.2024.106654},
pmid = {39645169},
issn = {1879-1220},
abstract = {Biofilms are complex microbial structures that have a significant impact on human health, industry and the environment. These complex structures represent one of the main mechanisms of microbial resistance, and their development constitutes a serious health problem. Therefore, the aim of this study was to verify the potential for inhibition and eradication of bacterial biofilm by salosodine, which is a steroidal alkaloid sapogenin found in plants of the Solanum genus. The antibiotics gentamicin, norfloxacin, ampicillin and the antiseptic agent chlorhexidine gluconate were used as positive controls to compare the results. Solasodin showed significant results in inhibiting the formation of Enterococcus faecalis and Staphylococcus aureus biofilms at the two concentrations tested. And when comparing the effect of solasodine for the two concentrations and the effect of the antibiotic gentamicin, it was found that sapogenin showed a better percentage in inhibiting E. faecalis biofilm formation. And against Pseudomonas aeruginosa, solasodine only inhibited biofilm formation at the highest concentration compared to the control. In the biofilm eradication results, solasodine showed a significant reduction in the biomass of the S. aureus biofilm, and when compared with the percentage reduction of the antibiotics, solasodine showed a relevant result for both concentrations. Only at the lowest concentration did solasodine show a reduction in P. aeruginosa biofilm biomass, a reduction close to that of chlorhexidine gluconate. In terms of activity, solasodine has been shown to have the potential to inhibit biofilm formation. However, further tests are needed to investigate the mechanisms of action of this sapogenin on the bacterial biofilms tested.},
}

@article {pmid39644415,
year = {2024},
author = {Wozeak, DR and Pereira, IL and Cardoso, TL and Neto, ACPS and Hartwig, DD},
title = {Genetic diversity, drug resistance, and biofilm formation in Klebsiella pneumoniae associated with nosocomial infection in Pelotas, RS, Brazil.},
journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]},
volume = {},
number = {},
pages = {},
pmid = {39644415},
issn = {1678-4405},
abstract = {Antibiotic resistance and the potential persistence of Klebsiella pneumoniae strains in hospital environments is an important challenge for human medicine. This research aims to detect resistance to antibiotics, biofilm formation, and the genetic pattern among clinical isolates associated with nosocomial infection obtained from a university hospital in the city of Pelotas, RS, Brazil. Twenty-eight isolates were identified at the species level by polymerase chain reaction (PCR) and were characterized regarding the profile of biofilm formation and antibiotic resistance. The genetic relationship was determined through pulsed-field gel electrophoresis (PFGE). The antibiotic resistance profile was made following the standards established by CLSI. All clinical isolates included in this study were confirmed as belonging to the species K. pneumoniae, 96.42% were considered strong biofilm formers and all were positive in the Congo Red agar (CRA) test. Thus, 64.29% of isolates were classified as multidrug-resistant (MDR), 25% as extensively drug-resistant (XDR), and 7.14% as pandrug-resistant (PDR). PFGE fingerprint analysis revealed 18 clones and of these, 15 have a unique pattern and another three were groups with patterns > 80% similarity. The clinical isolates used were collected over two years and revealed a genetic relationship. The same clone was identified in different types of samples and different years, demonstrating the permanence of the strain in the hospital environment. Our results reaffirm the need for greater measures of control and disinfection within the hospital environment, and the priority of therapeutic measures to contain the propagation of K. pneumoniae.},
}

@article {pmid39644379,
year = {2024},
author = {Samreen, and Ahmad, I},
title = {Antibacterial and anti-biofilm efficacy of 1,4-naphthoquinone against Chromobacterium violaceum: an in vitro and in silico investigation.},
journal = {Archives of microbiology},
volume = {207},
number = {1},
pages = {11},
pmid = {39644379},
issn = {1432-072X},
mesh = {*Biofilms/drug effects ; *Chromobacterium/drug effects/physiology ; *Naphthoquinones/pharmacology/chemistry ; *Anti-Bacterial Agents/pharmacology/chemistry ; *Microbial Sensitivity Tests ; Molecular Docking Simulation ; Computer Simulation ; Indoles ; },
abstract = {Antimicrobial resistance (AMR) is an urgent worldwide health concern, requiring the exploration for novel antimicrobial interventions. A Gram-negative bacterium, Chromobacterium violaceum, synthesizes quorum-sensing-regulated violacein pigment, develops resilient biofilms, and is often used for the screening of anti-infective drugs. The aim of this work is to assess the antibacterial and antibiofilm properties of three polyphenols: 1,4-naphthoquinone, caffeic acid, and piperine. The determination of antibacterial activity was conducted by the agar overlay and broth microdilution techniques. Analysis of membrane rupture was conducted by crystal violet uptake and β-galactosidase assay. Inhibition of biofilm was evaluated using a 96-well microtiter plate assay. Biofilm structures were visualized using light, scanning electron microscopy (SEM), and confocal laser scanning electron microscopy (CLSM). Among the phytochemicals, 1,4-naphthoquinone exhibited the highest antibacterial action (25 mm zone of inhibition). The minimum inhibitory concentration of 1,4-naphthoquinone was determined to be 405 µM. Outer and inner membrane permeability was enhanced by 52.01% and 1.28 absorbance, respectively. Violacein production was reduced by 74.85%, and biofilm formation was suppressed by 63.25% at sub-MIC levels (202.5 µM). Microscopic analyses confirmed reduced adhesion on surfaces. Hemolytic activity of 1,4-naphthoquinone showed a concentration-dependent effect, with 32.16% haemolysis at 202.5 µM. Molecular docking revealed significant interactions of 1,4-naphthoquinone with DNA gyrase followed by CviR. These findings highlight 1,4-naphthoquinone's potent antibacterial efficacy against C. violaceum, proposing its use as a surface coating agent to prevent biofilm formation on medical devices, thereby offering a promising strategy to combat bacterial infections.},
}

*Biofilms/drug effects
*Chromobacterium/drug effects/physiology
*Naphthoquinones/pharmacology/chemistry
*Anti-Bacterial Agents/pharmacology/chemistry
*Microbial Sensitivity Tests
Molecular Docking Simulation
Computer Simulation
Indoles

@article {pmid39643335,
year = {2024},
author = {Zhao, N and Mei, Y and Hou, X and Yang, M and Li, H and Liao, Q and Zhao, J and Ge, L},
title = {Comparative transcriptomic insight into orchestrating mode of dielectric barrier discharge cold plasma and lactate in synergistic inactivation and biofilm-suppression of Pichia manshurica.},
journal = {Food research international (Ottawa, Ont.)},
volume = {198},
number = {},
pages = {115323},
doi = {10.1016/j.foodres.2024.115323},
pmid = {39643335},
issn = {1873-7145},
mesh = {*Biofilms/growth & development/drug effects ; *Plasma Gases/pharmacology ; *Lactic Acid/metabolism ; *Transcriptome ; *Pichia/genetics/physiology/metabolism ; Food Microbiology ; },
abstract = {Pichia manshurica is a representative species of biofilm-forming yeasts which usually induces the spoilage of fermented food. This study aims to investigate the synergistic inactivating and anti-biofilm effect of dielectric barrier discharge cold plasma (DBD) and lactate on Pichia manshurica (P. manshurica) and the underlying mechanism by comparison of survival rate, growth curve, biofilm-forming capacity and transcriptome of P. manshurica treated with control (CK), lactate (LA), DBD, and combination of DBD and lactate (DBD-LA). Results showed that CK and LA hardly influenced the growth and biofilm formation of P. manshurica. DBD and DBD-LA reduced survival rate to 35 % and 10 % immediately after treatment, respectively. Also, with growth curve remaining plateau, DBD-LA completely inhibited the growth and biofilm formation of P. manshurica, while DBD moderately reduced the growth density and biofilm. Comparative transcriptomic analysis revealed that single DBD treatment intervened in the functions and pathways associated with DNA replication and cell adhesion (down-regulated expression of flocculation protein-related genes and up-regulated expression of β-1,4-D-glucan cellobiohydrolase-related genes). Lactate reinforced the inactivating and anti-biofilm effect of DBD by stimulating redox reaction and suppressing functions and pathways involving synthesis and metabolism of lipid and membrane, cation binding and organelle assembly. This study demonstrated the potential of synergistic combination of DBD and lactate in efficient control of biofilm-related spoilage of food by yeast.},
}

*Biofilms/growth & development/drug effects
*Plasma Gases/pharmacology
*Lactic Acid/metabolism
*Transcriptome
*Pichia/genetics/physiology/metabolism
Food Microbiology

@article {pmid39642791,
year = {2024},
author = {Wang, J and Sun, Y and Khunjar, W and Pace, G and McGrath, M and Chitrakar, S and Taylor, RL and Carroll, JR and Zhang, X and Wang, ZW},
title = {Mechanistic understanding of the performance difference between methanol- and glycerol-fed partial denitrification anammox in tertiary moving bed biofilm reactors treating real secondary effluent.},
journal = {Water research},
volume = {271},
number = {},
pages = {122893},
doi = {10.1016/j.watres.2024.122893},
pmid = {39642791},
issn = {1879-2448},
abstract = {Two pilot-scale tertiary moving bed biofilm reactor (MBBR) treatment trains were operated onsite for 371 days in a local wastewater treatment plant (WWTP) to compare their treatment performance and mechanistic difference when methanol and glycerol were used as carbon sources, respectively. Both trains were able to meet the tertiary effluent total inorganic nitrogen (TIN) requirement of < 3 mg/L, with 31.6% ∼ 46.3 % methanol savings or 30.9 % ∼ 43.8 % glycerol savings over full denitrification projected at influent dissolved oxygen in the range of 0∼3 mg/L. Very different nitrite provision mechanism was found between the two types of carbon sources, i.e., the nitrite sink by anammox through its outcompetition of dentification was the major source of nitrite provision mechanism for anammox bacteria when methanol was used as a carbon; while the rate differential between denitratation and denitritation was the major nitrite source when glycerol was used as a carbon. The cause of this mechanistic discrepancy can be ascribed to the dramatic different half-saturation constants between the two types of carbon sources (e.g., half saturation constant of glycerol was 1.7 times that of methanol). This study provided fundamental understandings that can be used to reconcile the controversy over whether methanol is suitable for partial denitrification anammox in low strength wastewater treatment.},
}

@article {pmid39640770,
year = {2024},
author = {Ullah, MA and Islam, MS and Ferdous, FB and Rana, ML and Hassan, J and Rahman, MT},
title = {Assessment of prevalence, antibiotic resistance, and virulence profiles of biofilm-forming Enterococcus faecalis isolated from raw seafood in Bangladesh.},
journal = {Heliyon},
volume = {10},
number = {20},
pages = {e39294},
pmid = {39640770},
issn = {2405-8440},
abstract = {Enterococcus faecalis are often resistant to different classes of antibiotics, harbor virulence determinants, and produce biofilm. The presence of E. faecalis in raw seafood exhibits serious public health significance. This study aimed to identify antibiotic resistance patterns and virulence factors in biofilm-forming E. faecalis strains extracted from seafood in Bangladesh. A total of 150 samples of raw seafood, comprising 50 shrimps, 25 crabs, and 75 fish, were collected and subjected to culturing, biochemical, and PCR assays to detect E. faecalis. The biofilm-forming abilities of the isolates were determined by Congo Red agar (CRA) plate and Crystal Violet Micro-titer Plate (CVMP) tests. Antibiotic resistance profiles were evaluated using the disk diffusion method. Virulence genes of the isolates were detected by PCR assay. The occurrence of E. faecalis was 29.3 % (44/150), which was higher in crabs and fish (36 %) than in shrimps (16 %). In CRA and CVMP tests, biofilm-forming abilities were observed in 88.64 % of the isolates, whereas 11 (25 %) and 28 (63.6 %) were strong- and intermediate-biofilm formers, respectively. All the isolates contained at least two virulence genes, including pil and ace (97.7 %), sprE (95.5 %), gelE (90.9 %), fsrB (79.6 %), agg (70.5 %), fsrA (68.2 %), and fsrC (61.4 %). All the isolates were phenotypically resistant to penicillin, followed by ampicillin and rifampicin (86.4 %), erythromycin (13.7 %), and tetracycline, vancomycin, norfloxacin, and linezolid (2.3 %). Resistant gene bla TEM was found in 61.4 % of the isolates. Moreover, the study found that E. faecalis strains with strong biofilm-forming capabilities had significantly higher levels of virulence genes and antibiotic resistance (p < 0.05) compared to those with intermediate and/or no biofilm-forming abilities. To the best of our knowledge, this research represents the first instance in Bangladesh of assessing antibiotic resistance and identifying virulence genes in biofilm-forming E. faecalis strains isolated from seafood samples. Our study revealed that seafood is a carrier of antibiotic-resistant, virulent, and biofilm-forming E. faecalis, demonstrating a potential public health threat.},
}

@article {pmid39640530,
year = {2024},
author = {Zhang, Z and Chen, G and Hussain, W and Pan, Y and Yang, Z and Liu, Y and Li, E},
title = {Machine learning and network analysis with focus on the biofilm in Staphylococcus aureus.},
journal = {Computational and structural biotechnology journal},
volume = {23},
number = {},
pages = {4148-4160},
pmid = {39640530},
issn = {2001-0370},
abstract = {Research on biofilm formation in Staphylococcus aureus has greatly benefited from the generation of high-throughput sequencing data to drive molecular analysis. The accumulation of high-throughput sequencing data, particularly transcriptomic data, offers a unique opportunity to unearth the network and constituent genes involved in biofilm formation using machine learning strategies and co-expression analysis. Herein, the available RNA sequencing data related to Staphylococcus aureus biofilm studies and identified influenced functional pathways and corresponding genes in the process of the transition of bacteria from planktonic to biofilm state by employing machine learning and differential expression analysis. Using weighted gene co-expression analysis and previously developed online prediction platform, important functional modules, potential biofilm-associated proteins, and subnetworks of the biofilm-formation pathway were uncovered. Additionally, several novel protein interactions within these functional modules were identified by constructing a protein-protein interaction (PPI) network. To make this data more straightforward for experimental biologists, an online database named SAdb was developed (http://sadb.biownmcli.info/), which integrates gene annotations, transcriptomics, and proteomics data. Thus, the current study will be of interest to researchers in the field of bacteriology, particularly those studying biofilms, which play a crucial role in bacterial growth, pathogenicity, and drug resistance.},
}

@article {pmid39639551,
year = {2024},
author = {Ma, Y and Kang, X and Wang, G and Luo, S and Luo, X and Wang, G},
title = {Inhibition of Staphylococcus aureus biofilm by quercetin combined with antibiotics.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-16},
doi = {10.1080/08927014.2024.2435027},
pmid = {39639551},
issn = {1029-2454},
abstract = {This study aimed to investigate the effects of combined quercetin and antibiotics on the bacteriostatic activity and biofilm formation of Staphylococcus aureus. Optimal concentrations of quercetin and antibiotics (tetracycline and doxycycline) for inhibiting biofilm formation were determined using the Fractional Inhibitory Concentration Index and Minimum Biofilm Inhibitory Concentration assays. The impact of the drug combinations on biofilm clearance at various formation stages was determined using crystal violet staining, scanning electron microscopy and confocal laser microscopy. The results indicated that quercetin enhanced the bactericidal effect of tetracycline antibiotics against S. aureus. The combination significantly reduced both the metabolic activity within S. aureus biofilms and the production of biofilm matrix components. Scanning electron microscopy and confocal laser microscopy confirmed that the combination treatment significantly reduced bacterial cell counts within the biofilm. Quercetin treatment significantly increased the sensitivity of biofilms to antibiotics, supporting its potential application as a novel antibiotic synergist.},
}

@article {pmid39639432,
year = {2024},
author = {Sharifi, A and Mahmoudi, P and Sobhani, K and Ashengroph, M},
title = {The Prevalence and Comparative Analysis of Adhesion and Biofilm-Related Genes in Staphylococcus aureus Isolates: A Network Meta-Analysis.},
journal = {Microbiology and immunology},
volume = {},
number = {},
pages = {},
doi = {10.1111/1348-0421.13189},
pmid = {39639432},
issn = {1348-0421},
support = {//The study was supported by University of Kurdistan, Iran./ ; },
abstract = {Staphylococcus aureus is a versatile pathogen capable of causing a wide range of infections, from minor skin infections to life-threatening invasive diseases. The pathogenicity of S. aureus is attributed to its ability to produce various virulence factors, including adhesion and biofilm-related proteins. Understanding the prevalence and distribution of these genes among S. aureus isolates from different sources is crucial for devising effective strategies to combat biofilm-associated contamination. In this study, we conducted a comprehensive network meta-analysis to assess the prevalence of adhesion and biofilm-related genes in S. aureus isolates and investigate the impact of the isolate source on their occurrence. A systematic search of multiple databases was performed, and a total of 53 relevant studies were included. The prevalence of adhesion and biofilm-related genes in S. aureus isolates was determined, with the highest prevalence observed for clfB (p-estimate = 85.4, 95% confidence interval [CI] 78-90.6), followed by eno (p-estimate = 81.1, 95% CI 61.7-91.9), and icaD (p-estimate = 77, 95% CI 68.6-83.6). Conversely, bap and bbp genes exhibited the lowest prevalence rates (p-estimate = 6.7 and 18.7, respectively). The network meta-analysis allowed us to examine the pairwise co-study of adhesion and biofilm-related genes in S. aureus isolates. The most frequently co-studied gene pairs were icaA-icaD (30 times) and fnbA-fnbB (25 times). Subgroup analysis showed that the occurrence of icaC and icaB genes was significantly lower in animal isolates compared to human and food isolates (p < 0.05). It is worth noting that there was limited data available for the analysis of sasG, bbp, bap, eno, and fib genes. In conclusion, the study revealed varying prevalence rates of adhesion and biofilm-related genes in S. aureus isolates. Genes such as clfB, eno, and icaD were found to be highly prevalent, while bap and bbp were less common. Limited existing data on the prevalence of genes like sasG, bbp, bap, eno, and fib highlights the need for further research to determine their exact prevalence rates. Our results contribute to a better understanding of S. aureus pathogenesis and can facilitate the development of effective strategies for the prevention and treatment of S. aureus infections.},
}

@article {pmid39638444,
year = {2025},
author = {Zhao, J and Wang, D and Wang, C and Lin, Y and Ye, H and Maung, AT and El-Telbany, M and Masuda, Y and Honjoh, KI and Miyamoto, T and Xiao, F},
title = {Biocontrol of Salmonella Schwarzengrund and Escherichia coli O157:H7 planktonic and biofilm cells via combined treatment of polyvalent phage and sodium hexametaphosphate on foods and food contact surfaces.},
journal = {Food microbiology},
volume = {126},
number = {},
pages = {104680},
doi = {10.1016/j.fm.2024.104680},
pmid = {39638444},
issn = {1095-9998},
mesh = {*Biofilms/growth & development/drug effects ; *Escherichia coli O157/growth & development/physiology/virology ; *Food Microbiology ; *Salmonella/growth & development/physiology/virology ; Food Contamination/prevention & control/analysis ; Plankton/growth & development/physiology ; Phosphates ; Colony Count, Microbial ; Triazines ; },
abstract = {Salmonella Schwarzengrund and Escherichia coli O157:H7 are ones of foodborne pathogens that can produce biofilms and cause serious food poisoning. Bacteriophages are an emerging antibacterial strategy used to prevent foodborne pathogen contamination in the food industry. In this study, the combined antibacterial effects of the polyvalent phage PS5 and sodium hexametaphosphate (SHMP) against both pathogens were investigated to evaluate their effectiveness in food applications. The combined treatment with phage PS5 (multiplicity of infection, MOI = 10) and 1.0% SHMP inhibited the growth of S. Schwarzengrund and E. coli O157:H7, and the viable counts of both decreased by more than 2.45 log CFU/mL. In KAGOME vegetable and fruit mixed juice, the combined treatment with PS5 (MOI = 100) and 1.0% SHMP also resulted in significant pathogen inactivation at 4 °C after 24 h. PS5 (10[10] PFU/mL) and 1.0% SHMP showed stronger synergistic effects on biofilm formation and the removal of established biofilms on polystyrene plates. Additionally, we evaluated their combined effects on reducing the biofilms of S. Schwarzengrund and E. coli O157:H7 on glass tubes and cabbage leaves at 4 °C. These findings indicate the utility of this approach in the biocontrol of the planktonic and biofilm cells of S. Schwarzengrund and E. coli O157:H7 on foods and food contact surfaces.},
}

*Biofilms/growth & development/drug effects
*Escherichia coli O157/growth & development/physiology/virology
*Food Microbiology
*Salmonella/growth & development/physiology/virology
Food Contamination/prevention & control/analysis
Plankton/growth & development/physiology
Phosphates
Colony Count, Microbial
Triazines