@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

@article {pmid39638047,
year = {2024},
author = {Kanaujia, R and Sharma, A and Biswal, M and Singh, V},
title = {What Doesn't Kill Biofilm, Makes Them Stronger: Critical Methodological Considerations For Endoscope Reprocessing.},
journal = {The Journal of hospital infection},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jhin.2024.06.024},
pmid = {39638047},
issn = {1532-2939},
}

@article {pmid39638004,
year = {2024},
author = {Wang, ZJ and Yang, XL and Sun, Y and Song, HL},
title = {Selection and optimization of biofilm carriers as high-effective microbial separator in microbial fuel cells.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {131941},
doi = {10.1016/j.biortech.2024.131941},
pmid = {39638004},
issn = {1873-2976},
abstract = {Four biofilm carriers including pyrite, manganese ore, ceramsite, and polyurethane sponge were used to construct microbial separators (MSs), while their performance in dual-chamber microbial fuel cells (MFCs) was evaluated. Polyurethane sponge and pyrite were superior biofilm carriers for MSs. The dense biofilm on the polyurethane sponge provides MS with optimal barrier capacity against dissolved oxygen and chemical oxygen demand. Pyrite's unique redox activity enhances proton transfer in MS and reduces ohmic resistance in MFC. The optimal thicknesses of polyurethane sponge MS and pyrite MS were 1.20 and 1.80 cm, and the maximum power densities of MFCs equipped with these two MSs were 14.62 and 11.21 W/m[3]. Using MSs as separators can significantly lower MFC manufacturing costs, particularly with polyurethane sponge MS at 3.52 $/m[2]. Additionally, MSs demonstrated good regenerability. These results indicated that MSs based on pyrite and polyurethane sponge have the potential to be high-effective separators for MFC scale-up.},
}

@article {pmid39637855,
year = {2024},
author = {Temme, JS and Tan, Z and Li, M and Yang, M and Wlodawer, A and Huang, X and Schneekloth, JS and Gildersleeve, JC},
title = {Insights into biofilm architecture and maturation enable improved clinical strategies for exopolysaccharide-targeting therapeutics.},
journal = {Cell chemical biology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.chembiol.2024.11.005},
pmid = {39637855},
issn = {2451-9448},
abstract = {Polysaccharide intercellular adhesin (PIA), an exopolysaccharide composed of poly-N-acetyl glucosamine (PNAG), is an essential component in many pathogenic biofilms. Partial deacetylation of PNAG is required for biofilm formation, but limited structural knowledge hinders therapeutic development. Employing a new monoclonal antibody (TG10) that selectively binds highly deacetylated PNAG and an antibody (F598) in clinical trials that binds highly acetylated PNAG, we demonstrate that PIA within the biofilm contains distinct regions of highly acetylated and deacetylated exopolysaccharide, contrary to the previous model invoking stochastic deacetylation throughout the biofilm. This discovery led us to hypothesize that targeting both forms of PNAG would enhance efficacy. Remarkably, TG10 and F598 synergistically increased in vitro and in vivo activity, providing 90% survival in a lethal Staphylococcus aureus challenge murine model. Our advanced model deepens the conceptual understanding of PIA architecture and maturation and reveals improved design strategies for PIA-targeting therapeutics, vaccines, and diagnostic agents.},
}

@article {pmid39636955,
year = {2024},
author = {Timoncini, A and Lorenzetti, L and Turner, RJ and McGibbon, A and Martini, C and Cofini, E and Bernardi, E and Chiavari, C},
title = {Inhibition of Pseudomonas aeruginosa biofilm formation on copper-based thin foils.},
journal = {PloS one},
volume = {19},
number = {12},
pages = {e0314684},
pmid = {39636955},
issn = {1932-6203},
mesh = {*Pseudomonas aeruginosa/drug effects/physiology ; *Biofilms/drug effects/growth & development ; *Copper/pharmacology/chemistry ; Humans ; Anti-Bacterial Agents/pharmacology/chemistry ; Surface Properties ; },
abstract = {The development of Healthcare-Associated Infections (HAIs) represents an increasing threat to patient health. In this context, Pseudomonas aeruginosa is responsible for various HAIs, determining about 20% of the infections in hospitalized patients, which makes it one of the most effective pathogens due to its strong ability to form biofilms. Using Cu-based materials as foils on high-touch surfaces can help to prevent and mitigate P. aeruginosa contamination in biohazardous settings. However, the antibiofilm properties of Cu-based surfaces against P. aeruginosa may vary due to frequent touches combined with indoor environmental exposure. The main aim of this study is to investigate the impact of accelerated ageing, mimicking a high-touch frequency by cyclic exposure to artificial sweat solution as well as to temperature and relative humidity variations, on the efficacy of Cu-based thin foils against P. aeruginosa biofilms. Three Cu-based materials (rolled and annealed Phosphorous High-Conductivity (PHC) Cu, Cu15Zn brass, and Cu18Ni20Zn nickel silver) were evaluated. The ageing process enhanced the antibiofilm properties, due to an increment in Cu ion release: aged PHC Cu and Cu15Zn exhibited the highest Cu ion release and hence the highest biofilm inhibition (decrease in colony forming unit (CFU)) in comparison to their pristine counterpart, while aged Cu18Ni20Zn displayed the lowest biofilm formation reduction, despite showing the highest aesthetic and morphological stability. The Cu-based surface, which highlited the highest biofilm formation inhibition due to accelerated ageing, was Cu15Zn.},
}

*Pseudomonas aeruginosa/drug effects/physiology
*Biofilms/drug effects/growth & development
*Copper/pharmacology/chemistry
Humans
Anti-Bacterial Agents/pharmacology/chemistry
Surface Properties

@article {pmid39636114,
year = {2024},
author = {Cruz-Cruz, A and Schreeg, ME and Gunn, JS},
title = {A temporary cholesterol-rich diet and bacterial extracellular matrix factors favor Salmonella spp. biofilm formation in the cecum.},
journal = {mBio},
volume = {},
number = {},
pages = {e0324224},
doi = {10.1128/mbio.03242-24},
pmid = {39636114},
issn = {2150-7511},
abstract = {Asymptomatic chronic carriers occur in approximately 5% of humans infected with Salmonella enterica serovar Typhi (S. Typhi) and represent a critical reservoir for bacterial dissemination. While chronic carriage primarily occurs in the gallbladder (GB) through biofilms on gallstones, additional anatomic sites have been suggested that could also harbor Salmonella. S. Typhimurium, orally infected 129 × 1/SvJ mice were pre-treated with a cholesterol-rich diet as a gallstone model for chronic carriage. We observed S. Typhimurium in feces and the cecum during early and persistent infection. Furthermore, bacterial biofilm-like aggregates were associated with the cecum epithelium at 7 and 21 days post-infection (DPI) in mice on a lithogenic diet (Ld) and correlated with an increase in cecal cholesterol at 21 DPI. Salmonella's extracellular matrix (ECM) was demonstrated as important in colonizing the cecum, as survival and aggregate formation significantly decreased when mice were infected with a quadruple ECM mutant strain. Gallbladder Salmonella counts were low at 36 DPI while cecal Salmonella were high, suggesting that gallbladder colonization was likely not responsible for the high cecal burden. All cecum phenotypes were significantly diminished in mice fed a normal diet (Nd). Finally, we examined the capability of S. Typhi to colonize the cecum and showed S. Typhi in feces and in aggregates in the cecum up to 7 DPI, with slightly higher counts in mice fed a Ld compared to Nd. Our findings suggest that the cecum, particularly under cholesterol-rich conditions, serves as an adaptative niche for Salmonella spp. aggregates/biofilms and is a putative site for long-term infection.IMPORTANCETyphoid fever is a systemic infectious disease triggered by the gastrointestinal dissemination of Salmonella Typhi and Paratyphi in humans. Three to five percent of infected individuals become chronic carriers, a state in which gallstone biofilm formation facilitates spread of the bacteria in feces. Notably, surgical removal of the gallbladder (GB) in some chronic carriers (22%) does not guarantee the elimination of the bacteria, and the rationale for this remains poorly understood. This study is significant as it explores other tissues associated with the chronic carrier state. It highlights not only a cholesterol-rich diet as an important etiological factor for Salmonella colonization but also identifies the cecum as a crucial tissue promoting fecal shedding. Additionally, we determined that biofilm matrix components of Salmonella are key factors contributing to these effects. A greater understanding of these mechanisms will allow the formulation of new therapeutic strategies specifically targeted at preventing typhoid fever dissemination from chronic carriers.},
}

@article {pmid39635909,
year = {2024},
author = {Zhao, Y and Zhang, J and Zhang, G and Huang, H and Tan, WS and Cai, H},
title = {Injectable Nanocomposite Hydrogel with Synergistic Biofilm Eradication and Enhanced Re-epithelialization for Accelerated Diabetic Wound Healing.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.4c17855},
pmid = {39635909},
issn = {1944-8252},
abstract = {Diabetic wounds remain a critical clinical challenge due to their harsh microenvironment, which impairs cellular function, hinders re-epithelialization and tissue remodeling, and slows healing. Injectable nanocomposite hydrogel dressings offer a promising strategy for diabetic wound repair. In this study, we developed an injectable nanocomposite hydrogel dressing (HDL@W379) using LAP@W379 nanoparticles and an injectable hyaluronic acid-based hydrogel (HA-ADH-ODEX). This dressing provided a sustained, pH-responsive release of W379 antimicrobial peptides, effectively regulating the wound microenvironment to enhance healing. The HDL@W379 hydrogel featured multifunctional properties, including mechanical stability, injectability, self-healing, biocompatibility, and tissue adhesion. In vitro, the HDL@W379 hydrogel achieved synergistic biofilm elimination and subsequent activation of basal cell migration and endothelial cell tube formation. Pathway analysis indicated that the HDL@W379 hydrogel enhances basal cell migration through MEK/ERK pathway activation. In methicillin-resistant Staphylococcus aureus (MRSA)-infected diabetic wounds, the HDL@W379 hydrogel accelerated wound healing by inhibiting bacterial proliferation and promoting re-epithelialization, regenerating the granulation tissue, enhancing collagen deposition, and facilitating angiogenesis. Overall, this strategy of biofilm elimination and basal cell activation to continuously regulate the diabetic wound microenvironment offers an innovative approach to treating chronic wounds.},
}

@article {pmid39634881,
year = {2024},
author = {Mumtaz, A and Saleem, U and Arif, M and Batool, N},
title = {Investigation of antibiotic resistance and biofilm formation ability of Acinetobacter baumannii isolated from urinary catheters.},
journal = {Pakistan journal of medical sciences},
volume = {40},
number = {11},
pages = {2643-2647},
pmid = {39634881},
issn = {1682-024X},
abstract = {OBJECTIVE: Current research aims to monitor the prevalence of Acinetobacter baumannii (A. baumannii) in healthcare facilities due to the development of resistance to antimicrobials. The study aimed to elucidate the interplay between antibiotic resistance and biofilm formation, two key factors contributing to virulence of bacteria.

METHODS: This study was conducted in One Health Laboratory (OHL) at Center for Advanced Studies, Agriculture and Food Security (CAS AFS), and institute of Microbiology University of Agriculture, Faisalabad within six months (Feb-Aug 2023). A total of 50 urine catheter samples were obtained from Allied Hospital, Faisalabad. Antibiotic susceptibility testing (meropenem, ampicillin, ceftriaxone, and gentamicin) was conducted to determine the resistance profiles of the isolates in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines. Additionally, the biofilm formation ability of the isolates was assessed using crystal violet staining.

RESULTS: Out of 50 samples, 13 were positive and were confirmed as multidrug resistant. The investigation of antibiotic resistance revealed a high prevalence of MDR A. baumannii strains from urinary catheters. The rate of infection was observed higher in males (77%), patients among the age group 10-25 and above 46 years (38.46%), and those who have been diagnosed with urinary tract infection (46.13%). The observed rate of biofilm formation was strong (62%) followed by moderate (7%), and weak (31%) in all MDR isolates. Carbapenem-resistant isolates exhibit a strong correlation with biofilm formation.

CONCLUSION: This study concluded that A. baumannii isolated from the patients with urinary tract infections had resistance to routinely used antibiotics. The isolates have shown hemolysis pattern (α & γ) and tendency to make biofilms. Moreover, except for ceftriaxone which showed negative correlations, a positive correlation was observed between biofilm biomass and the resistance profile to the remaining three antibiotics.},
}

@article {pmid39634722,
year = {2024},
author = {Mitra, A},
title = {Combatting biofilm-mediated infections in clinical settings by targeting quorum sensing.},
journal = {Cell surface (Amsterdam, Netherlands)},
volume = {12},
number = {},
pages = {100133},
pmid = {39634722},
issn = {2468-2330},
abstract = {Biofilm-associated infections constitute a significant challenge in managing infectious diseases due to their high resistance to antibiotics and host immune responses. Biofilms are responsible for various infections, including urinary tract infections, cystic fibrosis, dental plaque, bone infections, and chronic wounds. Quorum sensing (QS) is a process of cell-to-cell communication that bacteria use to coordinate gene expression in response to cell density, which is crucial for biofilm formation and maintenance.. Its disruption has been proposed as a potential strategy to prevent or treat biofilm-associated infections leading to improved treatment outcomes for infectious diseases. This review article aims to provide a comprehensive overview of the literature on QS-mediated disruption of biofilms for treating infectious diseases. It will discuss the mechanisms of QS disruption and the various approaches that have been developed to disrupt QS in reference to multiple clinical pathogens. In particular, numerous studies have demonstrated the efficacy of QS disruption in reducing biofilm formation in various pathogens, including Pseudomonas aeruginosa and Staphylococcus aureus. Finally, the review will discuss the challenges and future directions for developing QS disruption as a clinical therapy for biofilm-associated infections. This includes the development of effective delivery systems and the identification of suitable targets for QS disruption. Overall, the literature suggests that QS disruption is a promising alternative to traditional antibiotic treatment for biofilm-associated infections and warrants further investigation.},
}

@article {pmid39634676,
year = {2024},
author = {Bello, OO and Oni, MO and Bello, TK and Ilemobayo, AM and Ajagunna, AM and Osho, A},
title = {Biofilm-Forming Antibiotic-Resistant Bacteria in Water From Distribution Systems: Occurrence and Public Health Implications.},
journal = {International journal of microbiology},
volume = {2024},
number = {},
pages = {4147226},
pmid = {39634676},
issn = {1687-918X},
abstract = {Biofilm is a structurally-connected microbial community, covered by a self-produced polymeric matrix and adhered to biotic or abiotic surfaces. This study aimed to evaluate the occurrence of biofilm-producing antibiotic-resistant bacteria in water from distribution systems. Water samples were taken from 32 tanks across Ondo City and Akure metropolis, Nigeria. Information regarding the sanitation status of the tanks was gathered by observation and oral interviews. The physicochemical properties were determined using standard methods. Using the pour plate technique. Agars included serially diluted water samples were inoculated onto plate count agar, mannitol salt agar, Salmonella-Shigella agar, MacConkey agar, and cetrimide nutrient agar to assess total viable bacteria, Staphylococcus aureus, Salmonella and Shigella, coliforms, and Pseudomonas aeruginosa, respectively. Eosin-methylene blue agar was used to cultivate Escherichia coli and Enterobacter aerogenes. Pure isolates were characterised using API kits and assessed for antibiotic resistance and biofilm production employing the Kirby-Bauer and tissue culture plate techniques, respectively. The ages of the water tanks ranged from 1 to 25 years old; all tanks had cover-lids; 13 (40.63%) had water guards while 12 (37.5%) underwent water treatment. The physicochemical properties chiefly fell within WHO standards for drinking water. One hundred and eighty-seven isolates were obtained. S. aureus (15.51%) had the highest frequency while Salmonella enterica (3.2%) had the lowest frequency. Thirty-six percent of the isolates were strong biofilm producers, while 20.67% Gram-negative and 18.69% Gram-positive bacterial isolates were antibiotic-resistant. This study revealed a high occurrence of biofilm-forming bacteria and prevalence of antibiotic-resistant bacteria in water distribution systems, emphasizing the urgency of improving water quality for public health protection.},
}

@article {pmid39634280,
year = {2024},
author = {Xie, J and Sun, X and Xia, Y and Tao, L and Tan, T and Zhang, N and Xun, W and Zhang, R and Kovács, ÁT and Xu, Z and Shen, Q},
title = {Bridging the Gap: Biofilm-mediated establishment of Bacillus velezensis on Trichoderma guizhouense mycelia.},
journal = {Biofilm},
volume = {8},
number = {},
pages = {100239},
pmid = {39634280},
issn = {2590-2075},
abstract = {Bacterial-fungal interactions (BFIs) are important in ecosystem dynamics, especially within the soil rhizosphere. The bacterium Bacillus velezensis SQR9 and the fungus Trichoderma guizhouense NJAU 4742 have gathered considerable attention due to their roles in promoting plant growth and protecting their host against pathogens. In this study, we utilized these two model microorganisms to investigate BFIs. We firstly demonstrate that while co-inoculation of B. velezensis and T. guizhouense could promote tomato growth, these two microorganisms display mutual antagonism on agar solidified medium. To resolve this contradiction, we developed an inoculation method, that allows B. velezensis colonization of T. guizhouense hyphae and performed a transcriptome analysis. During colonization of the fungal hyphae, B. velezensis SQR9 upregulates expression of biofilm related genes (e.g. eps, tasA, and bslA) that is distinct from free-living cells. This result suggested an intricate association between extracellular matrix expression and hyphae colonization. In accordance, deletion epsD, tasA, or both epsD and tasA genes of B. velezensis diminished colonization of the T. guizhouense hyphae. The insights from our study demonstrate that soil BFIs are more complex than we understood, potentially involving both competition and cooperation. These intricate biofilm-mediated BFI dynamics might contribute to the remarkable diversity observed within soil microbiota, providing a fresh perspective for further exploration of BFIs in the plant rhizosphere.},
}

@article {pmid39633500,
year = {2024},
author = {Sandbakken, ET and Høyer, E and Witsø, E and Søgaard, CK and Díez-Sánchez, A and Hoang, L and Wik, TS and Bergh, K},
title = {Biofilm and the effect of sonication in a chronic Staphylococcus epidermidis orthopedic in vivo implant infection model.},
journal = {Journal of orthopaedic surgery and research},
volume = {19},
number = {1},
pages = {820},
pmid = {39633500},
issn = {1749-799X},
mesh = {*Biofilms/growth & development ; *Staphylococcus epidermidis ; Animals ; *Rats, Wistar ; *Prosthesis-Related Infections/microbiology ; *Sonication/methods ; *Staphylococcal Infections/microbiology ; *Disease Models, Animal ; Rats ; Chronic Disease ; Male ; Bone Plates ; },
abstract = {BACKGROUND: In diagnosing chronic orthopedic implant infections culture of sonicate represents a supplement to tissue cultures. However, the extent to which biofilm forms on implant surfaces and the degree of dislodgement of bacteria by sonication remains unclear. In this in vivo study using a low bacterial inoculum, we aimed to determine whether a variable effect of sonication could be observed in a standardized in vivo model.

MATERIALS AND METHODS: Seven Wistar rats underwent surgery with intramuscular implantation of two bone xenograft implants, each containing two steel plates. The grafts were inoculated with approximately 500 colony forming units (CFU) of Staphylococcus epidermidis ATCC 35984. After 20 days the rats were sacrificed, and the steel plates were removed from the bone grafts. Epifluorescence microscopy and scanning electron microscopy (SEM) were used to visualize biofilm formation and dislodgement on the plate surfaces. In addition to cultures of sonicate, a quantitative S. epidermidis specific PCR was developed for enumeration of bacteria.

RESULTS: A chronic, low-grade implant infection was successfully established, with all animals remaining in good health. All infected bone graft implants yielded abundant growth of S. epidermidis, with a median of 3.25 (1.6-4.6) × 10⁷ CFU per/graft. We were unable to distinguish infected plates from negative controls using epifluorescence microscopy. On infected plates small colonies of staphylococci were identified by SEM. The number of bacteria detected in the sonicate was low with 500 (100-2400) CFU/plate and 475 (140-1821) copies/plate by qPCR. The difference in area covered by fluorescent material before and after sonication was 10.1 (5.7-12.3) %, p = 0.018.

CONCLUSION: Despite the pronounced infection in the surrounding tissue, only few bacteria were detected on the surface of the steel implants. This is evident from the minimal findings by SEM before sonication, as well as the very low CFU counts and DNA copies in the sonicate. Sonication did not show variable effectiveness, indicating it is a valuable addition to, but not a replacement for biopsy cultures in cases of implant-associated infections with low-virulence microorganisms.},
}

*Biofilms/growth & development
*Staphylococcus epidermidis
Animals
*Rats, Wistar
*Prosthesis-Related Infections/microbiology
*Sonication/methods
*Staphylococcal Infections/microbiology
*Disease Models, Animal
Rats
Chronic Disease
Male
Bone Plates

@article {pmid39633147,
year = {2024},
author = {Farias-da-Silva, FF and Benine-Warlet, J and Groppo, FC and Steiner-Oliveira, C},
title = {Potentiation of antimicrobial photodynamic therapy with potassium iodide and methylene blue: targeting oral biofilm viability.},
journal = {Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology},
volume = {},
number = {},
pages = {},
pmid = {39633147},
issn = {1474-9092},
support = {88887.512822/2020-00//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; Finance code 001//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; },
abstract = {The study aimed to assess the impact of combining potassium iodide (KI) with methylene blue (MB) in antimicrobial photodynamic therapy (aPDT) within an oral biofilm formed in situ. A single-phase, 14 days in situ study involved 21 volunteers, who wore a palatal appliance with 8 bovine dentin slabs. These slabs were exposed to a 20% sucrose solution 8 times a day, simulating a high cariogenic challenge. Following the intraoral phase, the biofilms formed on the slabs were randomly assigned to the treatments: C (0.9% NaCl); CHX (0.2% chlorhexidine); KI (75 mM KI); MBKI (0.005% MB + 75 mM KI); L (0.9% NaCl + red laser 660 nm, 18 J, 180 s); LMB (0.005% MB + laser); LKI (75 mM KI + laser); LMBKI (0.005% MB + 75 mM KI + laser). The treated biofilms were collected, diluted, and incubated to assess cell viability (CFU/mL) for total microorganisms, total lactobacilli, total streptococci, and mutans streptococci. Data were subjected to analysis using the Friedman test, followed by the Dunn test (α = 0.05). LMBKI group exhibited a noteworthy decrease in the viability of all microorganisms in comparison to groups C, KI, MBKI, MB, L, LMB, and LKI (p < 0.0001), and demonstrated a comparable reduction to the CHX group (p > 0.99). The combination of KI with MB in aPDT may be advocated as a non-invasive technique for diminishing the viability of polymicrobial oral biofilms, thereby aiding in the management of dental diseases.},
}

@article {pmid39633009,
year = {2024},
author = {Park, S and Lee, ES and Kim, A and Kim, HJ and Lee, JY and Kim, SK and Jung, HI and Kim, BI},
title = {Development of a novel tongue biofilm index using bacterial biofluorescence.},
journal = {Scientific reports},
volume = {14},
number = {1},
pages = {30196},
pmid = {39633009},
issn = {2045-2322},
mesh = {Humans ; *Biofilms/growth & development ; *Tongue/microbiology ; Male ; Female ; Aged ; *Hydrogen Sulfide/metabolism/analysis ; Aged, 80 and over ; Sulfhydryl Compounds/metabolism ; Fluorescence ; Reproducibility of Results ; Bacteria/metabolism ; },
abstract = {Conventional methods for assessing tongue bacterial biofilms have low inter-examiner reliability due to visualization challenges. This study aimed to develop and assess a novel Tongue Biofilm Fluorescence Index (TBFI) for the accurate detection and objective evaluation of the quantitative and qualitative characteristics of tongue biofilms at the chairside. Data were collected from 81 elderly individuals (n = 162 images). Qraycam captured white-light and fluorescence images of the dorsal tongue, and two examiners assessed tongue coating (TC) using the TBFI. The TBFI was calculated based on biofilm intensity and coverage (0-2 scale). Inter-examiner agreement (Kappa) was compared with the Winkel's Tongue Coating Index (WTCI) and the Oho Index. Validity was evaluated through correlations with hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) levels. TBFI demonstrated the highest inter-examiner reliability (TBFI, κ = 0.752; WTCI, κ = 0.317; Oho Index, κ = 0.496), particularly for thickness rating (agreement rate: TBFI, 96.3%; WTCI, 76.5%; Oho Index, 79.6%). H2S and CH3SH concentrations showed significant positive correlations with all three indices, with the highest correlation observed between H2S and TBFI (TBFI, r = 0.369; WTCI, r = 0.304; Oho Index, r = 0.308; p < 0.01). Furthermore, H2S levels increased significantly with higher TBFI scores (p < 0.0001). TBFI shows enhanced reliability and validity, supporting its clinical potential.},
}

Humans
*Biofilms/growth & development
*Tongue/microbiology
Male
Female
Aged
*Hydrogen Sulfide/metabolism/analysis
Aged, 80 and over
Sulfhydryl Compounds/metabolism
Fluorescence
Reproducibility of Results
Bacteria/metabolism

@article {pmid39632887,
year = {2024},
author = {Siri, M and Vázquez-Dávila, M and Sotelo Guzman, C and Bidan, CM},
title = {Nutrient availability influences E. coli biofilm properties and the structure of purified curli amyloid fibers.},
journal = {NPJ biofilms and microbiomes},
volume = {10},
number = {1},
pages = {143},
pmid = {39632887},
issn = {2055-5008},
mesh = {*Biofilms/growth & development ; *Escherichia coli/physiology ; *Amyloid/metabolism/chemistry ; *Bacterial Proteins/metabolism/genetics ; *Nutrients/metabolism ; Escherichia coli Proteins/metabolism ; },
abstract = {Bacterial biofilms are highly adaptable and resilient to challenges. Nutrient availability can induce changes in biofilm growth, architecture and mechanical properties. Their extracellular matrix plays an important role in achieving biofilm stability under different environmental conditions. Curli amyloid fibers are critical for the architecture and stiffness of E. coli biofilms, but how this major matrix component adapts to different environmental cues remains unclear. We investigated, for the first time, the effect of nutrient availability both on biofilm material properties and on the structure and properties of curli amyloid fibers extracted from similar biofilms. Our results show that biofilms grown on low nutrient substrates are stiffer, contain more curli fibers, and these fibers present higher β-sheet content and chemical stability. Our multiscale study sheds new light on the relationship between bacterial matrix molecular structure and biofilm macroscopic properties. This knowledge will benefit the development of both anti-biofilm strategies and biofilm-based materials.},
}

*Biofilms/growth & development
*Escherichia coli/physiology
*Amyloid/metabolism/chemistry
*Bacterial Proteins/metabolism/genetics
*Nutrients/metabolism
Escherichia coli Proteins/metabolism

@article {pmid39631547,
year = {2024},
author = {Ni, J and Hu, Y and Liang, D and Cheng, J and Chen, Y and Zhu, X and Wang, G and Xie, J},
title = {Performance and mechanisms of nitrogen removal from low-carbon source wastewater in an iron-carbon coupled biofilm airlift internal circulation sequencing batch reactor.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {131925},
doi = {10.1016/j.biortech.2024.131925},
pmid = {39631547},
issn = {1873-2976},
abstract = {An iron-carbon coupled biofilm airlift internal circulation sequencing batch reactor (IC-SBR) was constructed to treat low-carbon source wastewater. Single-factor experiments were used to determine the optimal operating conditions for the IC-SBR, with a hydraulic retention time (HRT) of 10 h, a dissolved oxygen (DO) concentration of 3 mg/L, a C/N ratio of 3, and an influent NH4[+]-N concentration of 50 mg/L, with average removal efficiencies of total nitrogen (TN) and total organic carbon (TOC) of 78.06 % and 97.15 %, respectively. Mechanistic studies of the IC-SBR indicated that iron-carbon selectively enriched nitrogen removal microorganisms and promoted nitrogen removal efficiency. Carbon sources affected the secretion of extracellular polymeric substances (EPS), enzyme activities, electron transport system activity, nitrogen removal gene abundance, and community structure of microorganisms in the IC-SBR. Microorganisms use EPS as a supplementary carbon source to ensure nitrogen removal efficiency when the carbon source is insufficient.},
}

@article {pmid39631356,
year = {2024},
author = {Xia, W and Cai, Q and Wu, H and Li, J and Zhou, Z and Huang, C and Cheng, B},
title = {Improve anti-biofilm efficacy of ultrasound by modulating the phase transition of exopolysaccharides.},
journal = {Ultrasonics sonochemistry},
volume = {112},
number = {},
pages = {107100},
doi = {10.1016/j.ultsonch.2024.107100},
pmid = {39631356},
issn = {1873-2828},
abstract = {This study focused on the adverse sonochemical effect of ultrasound on biofilm extracellular polysaccharide and the adaptive biofilm responses for ultrasound resistance. Results showed ultrasound triggered phase transition of polysaccharides within biofilm from solation to gelation, which induced following biofilm viscoelasticity enhancement, consequential failure of biofilm removal and bacteria killing. Introducing additional cationic polysaccharide, 1.25 % chitosan, inhibited the ultrasound responsive polysaccharides gelation and biofilm viscoelasticity enhancement, exerted synergistic antibacterial (97.40 %) and antibiofilm (96.38 %) effects with 120 W ultrasound combined on S. aureus biofilm, prolonged the preservation time of milk 2.45 times longer compared with ultrasound alone. These findings indicated the possible mechanism and solution to improve ultrasound efficacy on biofilm control and bacteria suppression, exhibit the promising prospect of ultrasound combined strategy in hygiene issues of food and medical industry.},
}

@article {pmid39630533,
year = {2024},
author = {Mitsuwan, W and Saengsawang, P and Thaikoed, S and Tanthanathipchai, N and Saedan, P and Chaisiri, K and Boonmar, S and Morita, Y},
title = {Rattus spp. as Reservoirs of Multidrug Resistance- and Biofilm-Forming Escherichia coli in Urban Community from Southern Thailand.},
journal = {Foodborne pathogens and disease},
volume = {},
number = {},
pages = {},
doi = {10.1089/fpd.2024.0109},
pmid = {39630533},
issn = {1556-7125},
abstract = {Rats are rodents commonly found in Thailand that carry various zoonotic pathogens. Bacterial zoonosis can occur in a shared environment between humans and rats, especially in human communities and agricultural areas. Escherichia coli, particularly pathogenic and multidrug-resistant strains, is a significant public health concern that is transmitted by rats. This study aimed to investigate the antibiotic resistance (ABR) and biofilm formation of E. coli in caught rodents from Nakhon Si Thammarat province, Thailand. Captured rats were dissected to collect intestinal content for E. coli isolation. Two hundred and two confirmed E. coli were subjected for pathotype identification, antibiotic susceptibility testing, biofilm-forming ability (BFA), and the presence of related genes. Two E. coli isolates from intestinal content samples were atypical enteropathogenic (aEPEC). Predominantly, 52.97% of E. coli had azithromycin resistance, which was harbored by 35.64% of captured rats. Multidrug resistance (MDR) was found in 12.38% of E. coli isolates with 17 different MDR patterns. Remarkably, 96% of MDR isolates were resistant to azithromycin. Most E. coli harbored ereA (52%), followed by the blaTEM and aacC2 genes (6.44% each). Approximately 87% of isolated E. coli revealed moderate-to-high BFA. Predominantly, moderate-to-strong biofilm-forming E. coli harbored pgaA and pgaC genes. aEPEC, azithromycin resistance, MDR, and moderate-to-strong formation were the aspects of concern. Furthermore, the study of antibiotic-resistant E. coli in rats should be performed, particularly in terms of the transmission pathway, and the application of rats as bioindicators for ABR surveillance in Thailand should be established.},
}

@article {pmid39629932,
year = {2024},
author = {Doll-Nikutta, K and Weber, SC and Mikolai, C and Denis, H and Behrens, W and Szafrański, SP and Ehlert, N and Stiesch, M},
title = {Gradual Acidification at the Oral Biofilm-Implant Material Interface.},
journal = {Journal of dental research},
volume = {},
number = {},
pages = {220345241290147},
doi = {10.1177/00220345241290147},
pmid = {39629932},
issn = {1544-0591},
abstract = {The colonization of dental implants by oral biofilms causes inflammatory reactions that can ultimately lead to implant loss. Therefore, safety-integrated implant surfaces are under development that aim to detect bacterial attachment at an early stage and subsequently release antibacterial compounds to prevent their accumulation. Since primary oral colonizers ferment carbohydrates leading to local acidification, pH is considered a promising trigger for these surfaces. As a prerequisite for such systems, the present study aimed at specifically analyzing the pH at the interface between implant material and oral biofilms. For this purpose, in vitro-grown Streptococcus oralis monospecies biofilms and an established multispecies biofilm on titanium discs as well as in situ-grown biofilms from orally exposed titanium-equipped splints were used. Mature biofilm morphology was characterized by live/dead fluorescence staining, revealing improved growth from in vitro to in situ biofilms as well as a general decreasing membrane permeability over time due to the static incubation conditions. For pH analysis, the pH-sensitive dye C-SNARF-4 combined with 3-dimensional imaging by confocal laser-scanning microscopy and digital image analysis were used to detect extracellular pH values in different biofilm layers. All mature biofilms showed a pH gradient, with the lowest values at the material interface. Interestingly, the exact values depicted a time- and nutrient-dependent gradual acidification independently of the biofilm source and for in situ biofilms also independently of the sample donor. After short incubation times, a mild acidification to approximately pH 6.3 could be observed. But when sufficient nutrients were processed for a longer period of time, acidification intensified, leading to approximately pH 5.0. This not only defines the required turning point of pH-triggered implant release systems but also reveals the opportunity for a tailored release at different stages of biofilm formation.},
}

@article {pmid39629160,
year = {2024},
author = {Rachmawati, E and Asarina, S and Bagus Kennardi, G and Tabina Tawangalun, A and Arumimaniyah, C and Indah Sari, K and Tjaturina Pramesti, H and Safitri, R and Maskoen, AM},
title = {Isolation of Thermophilic Bacteria Geobacillus subterraneus From Mount Tangkuban Perahu and the Novelty as a Candidate for Streptococcus mutans Anti-Biofilm.},
journal = {International journal of dentistry},
volume = {2024},
number = {},
pages = {4285984},
pmid = {39629160},
issn = {1687-8728},
abstract = {Thermophilic bacteria living in extreme areas with high temperatures are capable of producing secondary metabolites, such as antimicrobial peptides (AMPs). AMPs are stable at high temperatures and show good antibacterial activity. Therefore, this study aimed to identify thermophilic bacteria from the crater of Mount Tangkuban Perahu around West Java and assess antibacterial effectiveness of AMPs against Streptococcus mutans, which contribute to oral biofilm formation. The isolate obtained was identified using 16S ribosomal ribonucleic acid (rRNA) gene sequencing, and the supernatant of the isolate was tested against S. mutans American Type Culture Collection (ATCC) 25175 using the disc assay method. To determine AMPs-coding genes, its genome was uploaded to antibiotic and secondary metabolite analysis shell (antiSMASH) 5.0.0 platform and biofilm inhibition was tested using the microtiter plate technique (with a 96-well bottom). Subsequently, the results were assessed using a microplate reader operating at 595 nm wavelength. The isolate was identified as Geobacillus subterraneus, with antibacterial activity against S. mutans, and produced an inhibition zone of 8.40 mm at an optimum pH of 8. The output of AMPs-coding gene showed that AMPs of the isolate were a member of the lanthipeptide class I, or bacteriocin-I group. AMPs of G. subterraneus suppressed the growth of S. mutans biofilm at a supernatant concentration of 5%, with the lowest optical density (OD) value of 0.061 and the highest percentage of biofilm growth inhibition at 28.24%. Based on the results, G. subterraneus derived from the crater of Mount Tangkuban Perahu showed potent antibacterial properties against S. mutans, making it a promising novel S. mutans anti-biofilm candidate.},
}

@article {pmid39628792,
year = {2024},
author = {Wu, X and Wang, C and Wang, D and Tawfik, A and Xu, R and Yu, Z and Meng, F},
title = {Achieving simultaneous removal of carbon and nitrogen by an integrated process of anaerobic membrane bioreactor and flow-through biofilm reactor.},
journal = {Engineering microbiology},
volume = {4},
number = {1},
pages = {100136},
pmid = {39628792},
issn = {2667-3703},
abstract = {In this study, a combined system consisting of an anaerobic membrane bioreactor (AnMBR) and flow-through biofilm reactor/CANON (FTBR/CANON) was developed to simultaneously remove carbon and nitrogen from synthetic livestock wastewater. The average removal efficiencies of total nitrogen (TN) were 64.2 and 76.4% with influent ammonium (NH4 [+]-N) concentrations of approximately 200 and 500 mg/L, respectively. The COD removal efficiencies were higher than 98.0% during the entire operation. Mass balance analysis showed that COD and TN were mainly removed by the AnMBR and FTBR/CANON, respectively. The anammox process was the main nitrogen removal pathway in the combined system, with a contribution of over 80%. High functional bacterial activity was observed in the combined system. Particularly, an increase in the NH4 [+]-N concentration considerably improved the anammox activity of the biofilm in the FTBR/CANON. 16S rRNA high-throughput sequencing revealed that Methanosaeta, Candidatus Methanofastidiosum, and Methanobacterium were the dominant methanogens in the AnMBR granular sludge. In the CANON biofilm, Nitrosomonas and Candidatus Kuenenia were identified as aerobic and anaerobic ammonium-oxidizing bacteria, respectively. In summary, this study proposes a combined AnMBR and FTBR/CANON process targeting COD and nitrogen removal, and provides a potential alternative for treating high-strength wastewater.},
}

@article {pmid39626168,
year = {2024},
author = {Abbott, IJ and Anderson, CRB and van Gorp, E and Wallis, SC and Roberts, JA and Meletiadis, J and Peleg, AY},
title = {Oral ciprofloxacin biofilm activity in a catheter-associated urinary tract infection model.},
journal = {The Journal of antimicrobial chemotherapy},
volume = {},
number = {},
pages = {},
doi = {10.1093/jac/dkae424},
pmid = {39626168},
issn = {1460-2091},
support = {//Australian Society for Antimicrobial/ ; APP1117065//Australian National Health and Medical Research Council/ ; //Australian/ ; APP2007007//for a Centre of Research Excellence/ ; APP2009736//Investigator Grant/ ; //Advancing Queensland Clinical Fellowship/ ; },
abstract = {BACKGROUND: Catheter-associated urinary tract infections (CA-UTIs) are a common hospital-acquired infection. We examined ciprofloxacin activity in a novel CA-UTI in vitro model.

METHODS: Three ATCC strains [Escherichia coli (ECO)-25922, Klebsiella pneumoniae (KPN)-700721, Pseudomonas aeruginosa (PAE)-27853] and 45 clinical urinary isolates were assessed. Biofilm mass and planktonic bacterial density were quantified during drug-free incubation (72 h) and following ciprofloxacin exposure (equivalent 750 mg orally q12h, 3 days).

RESULTS: ECO produced smaller biofilms (6.3 ± 1.1 log10 cfu/cm2) compared with KPN (7.1 ± 0.7 log10 cfu/cm2) and PAE (7.0 ± 1.2 log10 cfu/cm2), which extended along the entire catheter length. Following ciprofloxacin, all isolates with MIC > 4 mg/L had minimal biofilm disruption or planktonic kill. Ciprofloxacin resistance was most common in PAE isolates (10/16 isolates), compared with ECO (3/16 isolates) and KPN (6/16 isolates). Greater ciprofloxacin exposure (AUC0-24/MIC) was required for a 3 log10 biofilm kill for KPN (5858; R2 = 0.7774) compared with ECO (2117; R2 = 0.7907) and PAE (2485; R2 = 0.8260). Due to persistent growth in the bladder, ECO required greater ciprofloxacin exposure for a 3 log10 planktonic kill (5920; R2 = 0.8440) compared with KPN (2825; R2 = 0.9121) and PAE (1760; R2 = 0.8781). Monte Carlo simulation supported a 95% PTA for both a 3 log10 biofilm and planktonic kill for ECO and KPN isolates with MIC ≤ 0.5 mg/L and PAE isolates with MIC ≤ 1 mg/L.

CONCLUSIONS: In a novel CA-UTI model, following simulated ciprofloxacin therapy, KPN biofilms were comparatively more difficult to disrupt, ECO planktonic growth frequently persisted in the bladder, and PAE had greater propensity for emergence of ciprofloxacin resistance.},
}

@article {pmid39625293,
year = {2024},
author = {Zhao, D and Tang, M and Hu, P and Hu, X and Chen, W and Ma, Z and Chen, H and Liu, H and Cao, J and Zhou, T},
title = {Antimicrobial peptide Hs02 with rapid bactericidal, anti-biofilm, and anti-inflammatory activity against carbapenem-resistant Klebsiella pneumoniae and Escherichia coli.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0105024},
doi = {10.1128/spectrum.01050-24},
pmid = {39625293},
issn = {2165-0497},
abstract = {UNLABELLED: Carbapenem-resistant Klebsiella pneumoniae (CRKP) and Escherichia coli (CREC) are frequently detected in clinical settings, restricting the use of carbapenems. Therefore, there is an urgent need for new antimicrobial strategies to address infections caused by CRKP and CREC. This study investigated the antibacterial, anti-biofilm, and anti-inflammatory effects of the cationic antimicrobial peptide Hs02, along with its potential antimicrobial mechanisms against CRKP and CREC. The results revealed that Hs02 had a low minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against CRKP and CREC, effectively eliminating the bacteria within 30 min. Moreover, Hs02 significantly prevents biofilm formation and disrupts the established biofilms. Further mechanistic studies demonstrated that Hs02 specifically targeted and bound to bacterial outer membrane lipopolysaccharides (LPS), disrupted membrane permeability and integrity, which led to intracellular reactive oxygen species (ROS) accumulation. Furthermore, Hs02 neutralized LPS, thereby suppressing the production of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β in murine macrophage RAW 264.7 cells. In vitro, hemolysis and cytotoxicity assays confirmed Hs02's safety at the tested concentrations and proved that Hs02 improved the survival rate of Galleria mellonella larvae. In conclusion, the findings suggest that Hs02's interaction with LPS and the resulting disruption of membrane integrity may be key factors driving its rapid bactericidal and anti-inflammatory effects.

IMPORTANCE: Eukaryotic antimicrobial peptides are typically amphipathic peptides consisting of approximately 50 amino acids. Many macromolecular proteins in our body contain polypeptide sequences that show characteristics similar to those of antimicrobial peptides. The present research highlights a gap in the current literature regarding the mechanisms by which the intragenic antimicrobial peptide Hs02, derived from human proteins, exerts its rapid bactericidal and anti-inflammatory effects. The findings demonstrate that lipopolysaccharide (LPS) is a key target of Hs02's antimicrobial activity and that its ability to neutralize LPS is crucial for its anti-inflammatory effects.},
}

@article {pmid39624194,
year = {2024},
author = {Eidaroos, NH and Eid, HI and Nasef, SAA and Mansour, GH and El-Tarabili, RM},
title = {The impact of quorum sensing and biofilm formation on antimicrobial resistance and virulence of XDR and MDR Pseudomonas aeruginosa in laying chickens.},
journal = {Iranian journal of veterinary research},
volume = {25},
number = {2},
pages = {125-134},
pmid = {39624194},
issn = {1728-1997},
abstract = {BACKGROUND: Pseudomonas aeruginosa plays a major influence on poultry outbreaks. Several factors may contribute to its pathogenicity.

AIMS: This study aimed to investigate the prevalence of P. aeruginosa infection among layer chickens with phenotypic and genotypic characterization of the isolates.

METHODS: Samples (n=160) were collected from respiratory distressed layer chickens according to the lesion and bacteriologically examined for isolation of P. aeruginosa from Sharkia province, Egypt. The antimicrobial sensitivity was performed against 18 antimicrobial agents. A qualitative assessment of biofilm production was performed using the Tube method. The isolates were genetically examined for confirmation, detection of quorum sensing genes, virulence genes, and biofilm production genes by conventional PCR.

RESULTS: P. aeruginosa was isolated from 25% of the samples. Moreover, 95% of the isolates were extensively drug-resistant (XDR) with multiple antibiotic resistance indices (MARI) of 0.67 to 0.83. A total of 38 isolates were able to produce biofilm with different degrees. PCR of 16S rRNA (P. aeruginosa) and oprL genes confirmed the existence of P. aeruginosa isolates. For quorum sensing genes, lasI and lasR were successfully amplified at 100% and 89.5%, respectively. For virulence genes, toxA and exoU were amplified by a percentage of 78.9%, while the higBA gene was in 100% of the isolates. pprA and pprB genes were amplified at 100% and 89.5%, respectively. For biofilm genes, pslA, fliC, and pelA were amplified in 100%, 84.2%, and 10.5%, respectively.

CONCLUSION: A strong correlation between quorum sensing genes, biofilm genes, and virulence genes was detected. Further, biofilm production increases the resistance of the isolates to antimicrobial agents.},
}

@article {pmid39624045,
year = {2024},
author = {Niranjan, R and Patil, S and Dubey, A and Lochab, B and Priyadarshini, R},
title = {Small cyclic dipeptide produced by Lactobacillus rhamnosus with anti-biofilm properties against Streptococcus mutans biofilm.},
journal = {Biofilm},
volume = {8},
number = {},
pages = {100237},
pmid = {39624045},
issn = {2590-2075},
abstract = {The human oral cavity harbors many bacterial species collectively termed the oral microbiome and is integral for maintaining oral health. Dysbiosis of oral microbiota leads to common oral diseases, including dental caries, gingivitis, and periodontitis. Streptococcus mutans is the primary causative agent of dental caries. Studies have explored the use of probiotic Lactobacillus spp. to mitigate S. mutans biofilms. In the present study, we have tested the use of Lactobacillus rhamnosus extracts/metabolites for anti-biofilm properties. A small organic compound/metabolite was isolated from the cell-free supernatant of L. rhamnosus, and this metabolite resulted in a dose-dependent inhibition of S. mutans biofilms. Confocal microscopy revealed that the thickness of S. mutans biofilms was severely reduced upon metabolite treatment. With the help of FTIR spectra and mass spectrometry analysis, the molecular formula (C11H19O2N2) was deduced. The inhibitor compound was further identified as a small cyclic peptide, cyclo (-L-Leu-L-Pro). Our data also revealed that isolated metabolite impedes S. mutans biofilms by modulating gene expression of several essential genes involved in biofilm establishment.},
}

@article {pmid39622869,
year = {2024},
author = {Wang, D and Wang, S and Sun, W and Chen, T and Liang, C and Yang, P and Liu, Q and Zhao, C and Chen, Y},
title = {Biofilm-based biocatalysis for β-cyclodextrin production by the surface-display of β-cyclodextrin glycosyltransferase in Bacillus subtilis.},
journal = {Scientific reports},
volume = {14},
number = {1},
pages = {29925},
pmid = {39622869},
issn = {2045-2322},
support = {22178176//National Natural Science Foundation of China/ ; 22208157//National Natural Science Foundation of China/ ; 2022YFC2105400//National Key R&D Program of China/ ; SICAM-XTA2201//Jiangsu National Synergetic Innovation Center for Advanced Materials/ ; 2023BEE01011//Key R&D project of Ningxia Hui Autonomous Region/ ; SKL-MCE-22A04//State Key Laboratory of Materials-Oriented Chemical Engineering/ ; },
mesh = {*Bacillus subtilis/genetics/metabolism/enzymology ; *beta-Cyclodextrins/metabolism ; *Biofilms/growth & development ; *Biocatalysis ; *Glucosyltransferases/metabolism/genetics ; Fermentation ; Temperature ; Hydrogen-Ion Concentration ; Bacterial Proteins/metabolism/genetics ; Enzymes, Immobilized/metabolism/genetics ; },
abstract = {β-cyclodextrin (β-CD) is an important cyclic oligosaccharide, which is widely applicated in foods, environmental protection, and cosmetics, primarily prepared from enzymatic synthesis in traditional industry. However, several challenges persist, including cumbersome processes and difficulties in achieving continuous fermentation and catalysis. This research introduced a biofilm-based immobilized fermentation, integrating with enzyme catalysis system of surface display in Bacillus subtilis. The bslA gene was selected to construct the surface display system due to its ability to promote biofilm formation and serve as an anchorin. Compared to free cell catalysis, the biofilm-based immobilized catalysis expanded the temperature range to 40-70 and the pH range to 5-7.5. During the continuous catalysis process, by the 13th batch, the relative activity remained around 52%, and the conversion rate exceeded 36%, similar to the single-batch free cell catalysis. These findings provide valuable insights and effective strategies for the industrial production of β-CD and other biochemicals through continuous catalysis.},
}

*Bacillus subtilis/genetics/metabolism/enzymology
*beta-Cyclodextrins/metabolism
*Biofilms/growth & development
*Biocatalysis
*Glucosyltransferases/metabolism/genetics
Fermentation
Temperature
Hydrogen-Ion Concentration
Bacterial Proteins/metabolism/genetics
Enzymes, Immobilized/metabolism/genetics

@article {pmid39622673,
year = {2024},
author = {Lai, L and Ding, W and Huang, G and Wang, M and Chen, J and Lai, L and Deng, X and Tang, L and Yu, X and Huang, Y and Truong, TMH and Zhang, Z and Ding, W},
title = {Preparation and Methicillin-Resistant Staphylococcus aureus Biofilm Elimination Effect of Baicalein-Loaded Hyaluronic acid/β-Cyclodextrin grafted Chitosan Nanoparticles.},
journal = {Biomedical and environmental sciences : BES},
volume = {37},
number = {10},
pages = {1227-1231},
doi = {10.3967/bes2024.160},
pmid = {39622673},
issn = {2214-0190},
}

@article {pmid39622419,
year = {2024},
author = {Niu, H and Zhu, D and Leng, J and Wang, Z and Liu, D and Chen, Y and Yang, P and Ying, H},
title = {Biofilm-based immobilized fermentation of engineered Komagataella phaffii for xylanase production.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {131918},
doi = {10.1016/j.biortech.2024.131918},
pmid = {39622419},
issn = {1873-2976},
abstract = {This study presented an immobilized fermentation process of engineered Komagataella phaffii with improved biofilm-forming abilities for continuous xylanase production and provided the first insights into the molecular basis of biofilm-based immobilized fermentation of K. phaffii. Overexpression of PAS_chr2-2_0178 and PAS_FragB_0067 in K. phaffii facilitated biofilm formation with 31.6% and 113.8% increasement, respectively. Subsequently, a biofilm-based immobilized fermentation process was developed for the PAS_FragB_0067-overexpressing strain. Xylanase production over five batches by GS115-0067* was better than that of GS115-xyn, with an overall average of 35.4% higher enzyme activity. PAS_FragB_0067 overexpression resulted in better adhesion of K. phaffii cells on the carrier, and enhanced biofilms could provide more active cells in the immobilized fermentation process. Transcriptome analysis revealed that overexpression of the biofilm-related gene promoted central carbon metabolism. These findings offer a valuable reference strategy to improve production efficiency of K. phaffii cells in continuous fermentation processes.},
}

@article {pmid39621768,
year = {2024},
author = {Weerasekera, R and Moreau, A and Huang, X and Nam, KM and Hinbest, A and Huynh, Y and Liu, X and Ashwood, C and Pepi, LE and Paulson, E and Cegelski, L and Yan, J and Olson, R},
title = {Vibrio cholerae RbmB is an α-1,4-polysaccharide lyase with biofilm-disrupting activity against Vibrio polysaccharide (VPS).},
journal = {PLoS pathogens},
volume = {20},
number = {12},
pages = {e1012750},
doi = {10.1371/journal.ppat.1012750},
pmid = {39621768},
issn = {1553-7374},
abstract = {Many pathogenic bacteria form biofilms as a protective measure against environmental and host hazards. The underlying structure of the biofilm matrix consists of secreted macromolecules, often including exopolysaccharides. To escape the biofilm, bacteria may produce a number of matrix-degrading enzymes, including glycosidic enzymes that digest exopolysaccharide scaffolds. The human pathogen Vibrio cholerae assembles and secretes an exopolysaccharide called VPS (Vibrio polysaccharide) which is essential in most cases for the formation of biofilms and consists of a repeating tetrasaccharide unit. Previous studies have indicated that a secreted glycosidase called RbmB is involved in V. cholerae biofilm dispersal, although the mechanism by which this occurs is not understood. To approach the question of RbmB function, we recombinantly expressed and purified RbmB and tested its activity against purified VPS. Using a fluorescence-based biochemical assay, we show that RbmB specifically cleaves VPS in vitro under physiological conditions. Analysis of the cleavage process using mass spectrometry, solid-state NMR, and solution NMR indicates that RbmB cleaves VPS at a specific site (at the α-1,4 linkage between D-galactose and a modified L-gulose) into a mixture of tetramers and octamers. We demonstrate that the product of the cleavage contains a double bond in the modified guluronic acid ring, strongly suggesting that RbmB is cleaving using a glycoside lyase mechanism. Finally, we show that recombinant RbmB from V. cholerae and the related aquatic species Vibrio coralliilyticus are both able to disrupt living V. cholerae biofilms. Our results support the role of RbmB as a polysaccharide lyase involved in biofilm dispersal, as well as an additional glycolytic enzyme to add to the toolbox of potential therapeutic antibacterial enzymes.},
}

@article {pmid39621545,
year = {2024},
author = {Zheng, Z and Chen, J and Srinual, S and Tumbas Šaponjac, V and Yin, T and Wang, BY and Sun, R and Hu, M},
title = {Buprenorphine Salivary Gland Accumulation Sustaining High Oral Fluid Exposure and Increasing the Risk of Streptococcus mutans Biofilm Formation.},
journal = {Journal of addiction medicine},
volume = {},
number = {},
pages = {},
doi = {10.1097/ADM.0000000000001401},
pmid = {39621545},
issn = {1935-3227},
abstract = {OBJECTIVES: The US Food and Drug Administration (FDA) issued a warning about buprenorphine-induced dental caries of unknown mechanism in 2022. To investigate the potential mechanism, the association between local buprenorphine exposure and dental biofilm formation will be explored in this study.

METHODS: Female F344 rats were dosed with sublingual buprenorphine film or intravenous injection to explore the oral cavity exposure of the buprenorphine. The buprenorphine distribution in salivary glands after the sublingual and intravenous administration was also evaluated. To investigate the effects of buprenorphine exposure on dental caries formation, buprenorphine's impact on the biofilm formation of S. mutans in vitro was measured.

RESULTS: The absolute sublingual bioavailability of buprenorphine in rats was 17.8% with a high ratio of oral fluid exposure to blood concentration in the pharmacokinetic study. Salivary gland concentrations of buprenorphine and its active metabolite norbuprenorphine were significantly higher than their blood concentrations after both sublingual (s.l.) and intravenous (i.v.) administration. Correlation analysis showed that the oral fluid concentration of buprenorphine and norbuprenorphine was highly correlated to salivary gland concentration rather than blood concentration. These data indicate that the salivary gland serves as an accumulation organ for buprenorphine, allowing prolonged oral fluid exposure to buprenorphine. Lastly, buprenorphine and its metabolites contributed to the biofilm formation of S. mutans in high concentration.

CONCLUSIONS: Sublingual administration substantially increased the salivary gland distribution of buprenorphine and norbuprenorphine. Depot effects following sublingual dosing and salivary gland accumulation likely sustained high oral fluid exposure to buprenorphine and stimulated the biofilm formation of S. mutans.},
}

@article {pmid39618743,
year = {2024},
author = {Kurtzman, GM and Horowitz, RA and Johnson, R and Pedro, Z},
title = {Oral Biofilm and Its Connection to Alzheimer's Disease.},
journal = {Cureus},
volume = {16},
number = {11},
pages = {e72841},
pmid = {39618743},
issn = {2168-8184},
abstract = {Dementia and Alzheimer's disease are common occurrences in the population, affecting many patients. Recent research and studies have found a link between oral biofilm and the initiation of these conditions or the worsening of their presentation. Periodontal disease and the associated oral biofilm with its bacteria are often not considered by the medical community when treating these or their patients. Coordination of therapy with a dentist can improve the patient's oral health. Decreasing bacteria in the oral biofilm allows the physician and dentist to provide coordinated total healthcare. Emphasis and education of the patient on the importance of maintaining good oral homecare and routine dental recall prophylaxis appointments to improve their systemic health and limit the progression and worsening of mental health conditions. This article discusses the connection between oral biofilm and systemic health, specifically Alzheimer's disease, and how to improve those conditions through oral healthcare.},
}

@article {pmid39618639,
year = {2024},
author = {Ganjo, AR},
title = {Evaluation of the Anti-biofilm Activity of Vitamins Against Acinetobacter baumannii and Klebsiella pneumoniae Recovered From Clinical Specimens: An In Vitro and In Silico Analysis.},
journal = {Cureus},
volume = {16},
number = {10},
pages = {e72679},
pmid = {39618639},
issn = {2168-8184},
abstract = {INTRODUCTION: Pathogens that form biofilms reduce the effectiveness of conventional treatments and promote antibiotic resistance. Therefore, this study aimed to investigate the antibiofilm properties of vitamin C (ascorbic acid) and vitamin D (cholecalciferol) experimentally.

METHODS: The antibiofilm properties of the studied compounds were evaluated using molecular docking analyses. AutoDock Vina software (The Scripps Research Institute, La Jolla, California) was used to assess the binding affinity of vitamins C and D to the active sites of biofilm-related proteins.

RESULTS: Molecular docking revealed different affinities toward the active sites of the target proteins. The interactions showed promising results, with vitamin D forming both hydrogen bonds and hydrophobic interactions. Compared to vitamin C, vitamin D exhibited the highest binding affinity, with a score of -10.8 kcal/mol.

CONCLUSION: However, molecular dynamics simulations are needed to further elucidate the dynamic behaviors and stability of these compound-protein complexes. Vitamin D demonstrated good in vitro potential as an anti-biofilm agent and should be considered for use alongside antibiotics in the treatment of bacterial infections.},
}

@article {pmid39617946,
year = {2024},
author = {Miguélez-Pérez, R and Mencía-Ares, O and Gutiérrez-Martín, CB and González-Fernández, A and Petrocchi-Rilo, M and Delgado-García, M and Martínez-Martínez, S},
title = {Biofilm formation in Streptococcus suis: in vitro impact of serovars and assessment of coinfections with other porcine respiratory disease complex bacterial pathogens.},
journal = {Veterinary research},
volume = {55},
number = {1},
pages = {157},
pmid = {39617946},
issn = {1297-9716},
mesh = {Animals ; *Streptococcus suis/physiology ; *Biofilms/growth & development ; *Swine Diseases/microbiology ; Swine ; *Coinfection/veterinary/microbiology ; *Streptococcal Infections/veterinary/microbiology ; *Serogroup ; Spain ; },
abstract = {Streptococcus suis is a worldwide pathogen that impacts the swine industry, causing severe clinical signs, including meningitis and arthritis, in postweaning piglets. A key virulence mechanism of S. suis is biofilm formation, which improves its persistence and resistance to external factors. Here, we assessed the in vitro biofilm formation of 240 S. suis isolates from Spanish swine farms and evaluated the effects of serovars (SVs) and coinfections with other porcine respiratory disease complex (PRDC) pathogens. Our study revealed significant heterogeneity in biofilm formation among S. suis SVs. Notably, SV2 resulted in the lowest degree of biofilm formation, in contrast with the high biofilm-forming capacities of SV1, SV7, and SV9. Other PRDC pathogens, including Actinobacillus pleuropneumoniae, Glaesserella parasuis, and Pasteurella multocida, formed biofilms, although they were generally less robust than those of S. suis (except for SV2), which contrasts with the high biofilm formation of Staphylococcus hyicus. Coinfections enhanced biofilm formation in mixed cultures of S. suis, particularly with P. multocida. Other coinfections revealed variable results in pathogen interactions, suggesting the potential of biofilms for increased persistence and pathogenicity in coinfections. In conclusion, this study underscores the importance of serovar-specific differences in biofilm formation among S. suis isolates, with significant implications for pathogenicity and persistence. The heterogeneous biofilm formation observed in coinfections with other PRDC pathogens reveals a complex interplay that could exacerbate disease severity. These findings provide a foundation for further research on biofilm mechanisms to mitigate the impact of PRDC in the swine industry.},
}

Animals
*Streptococcus suis/physiology
*Biofilms/growth & development
*Swine Diseases/microbiology
Swine
*Coinfection/veterinary/microbiology
*Streptococcal Infections/veterinary/microbiology
*Serogroup
Spain

@article {pmid39617560,
year = {2025},
author = {Wang, Y and Zhang, Y and Zhu, X and Tang, Y and Zhang, Y},
title = {Plasmid-mediated transfer of antibiotic resistance genes and biofilm formation in a simulated drinking water distribution system under chlorine pressure.},
journal = {Journal of environmental sciences (China)},
volume = {152},
number = {},
pages = {376-388},
doi = {10.1016/j.jes.2024.05.021},
pmid = {39617560},
issn = {1001-0742},
mesh = {*Biofilms/drug effects ; *Chlorine ; *Drinking Water/microbiology ; *Plasmids/genetics ; *Disinfectants ; *Drug Resistance, Microbial/genetics ; Water Microbiology ; Water Purification/methods ; Genes, Bacterial ; },
abstract = {The effects of disinfectants and plasmid-based antibiotic resistance genes (ARGs) on the growth of microorganisms and the plasmid-mediated transfer of ARGs in the water and biofilm of the drinking water distribution system under simulated conditions were explored. The heterotrophic plate count of the water in reactors with 0.1 mg/L NaClO and NH2Cl was higher than in the control groups. There was no similar phenomenon in biofilm. In the water of reactors containing NaClO, the aphA and bla genes were lower than in the antibiotic resistant bacteria group, while both genes were higher in the water of reactors with NH2Cl than in the control group. Chloramine may promote the transfer of ARGs in the water phase. Both genes in the biofilm of the reactors containing chlorine were lower than the control group. Correlation analysis between ARGs and water quality parameters revealed that the copy numbers of the aphA gene were significantly positively correlated with the copy numbers of the bla gene in water and significantly negatively correlated in biofilm (p < 0.05). The results of the sequencing assay showed that bacteria in the biofilm, in the presence of disinfectant, were primarily Gram-negative. 1.0 mg/L chlorine decreased the diversity of the community in the biofilm. The relative abundance of some bacteria that may undergo transfer increased in the biofilm of the reactor containing 0.1 mg/L chlorine.},
}

*Biofilms/drug effects
*Chlorine
*Drinking Water/microbiology
*Plasmids/genetics
*Disinfectants
*Drug Resistance, Microbial/genetics
Water Microbiology
Water Purification/methods
Genes, Bacterial

@article {pmid39616895,
year = {2024},
author = {Xu, L and Zhang, X and Wang, W and Shen, J and Ma, K and Wang, H and Xue, T},
title = {The global regulator SpoVG is involved in biofilm formation and stress response in foodborne Staphylococcus aureus.},
journal = {International journal of food microbiology},
volume = {428},
number = {},
pages = {110997},
doi = {10.1016/j.ijfoodmicro.2024.110997},
pmid = {39616895},
issn = {1879-3460},
abstract = {Staphylococcus aureus (S. aureus) is a primary culprit of food poisoning. As a highly adaptable pathogen, S. aureus demonstrates formidable biofilm-forming and stress tolerance capabilities, inducing significant challenges to eradicate food contamination caused by this organism. SpoVG, a regulatory protein in S. aureus, controls the expression of numerous genes. However, its role in biofilm formation and stress response in foodborne S. aureus remains to be elucidated. In this study, we investigated the functions of SpoVG involved in food-related stress responses and biofilm formation in S. aureus RMSA50. The results demonstrated that SpoVG deletion enhanced biofilm formation and resistance to heat and desiccation, while decreased tolerance to oxidative stress. Further analysis revealed that cell aggregation and the accumulation of extracellular DNA (eDNA) may contribute to the enhanced biofilm formation. Real-time quantitative reverse transcription-PCR (RT-qPCR) revealed that the expression levels of nuc and sasC, which are related to cell aggregation and eDNA concentration, were significantly altered in the spoVG mutant. Electrophoretic mobility shift assays (EMSA) confirmed that SpoVG directly binds to the promoter region of nuc and sasC to regulate their expression. These findings suggest that SpoVG may serve as a target to decrease biofilm formation and control S. aureus contamination in the food industry.},
}

@article {pmid39615850,
year = {2024},
author = {Gómez-Martínez, D and Selvin, MA and Nilsson, AK and Carmona, E and Ngou, JS and Kristiansson, E and Nilsson, RH and Corcoll, N},
title = {Environmental concentrations of the fungicide tebuconazole alter microbial biodiversity and trigger biofilm-released transformation products.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {143854},
doi = {10.1016/j.chemosphere.2024.143854},
pmid = {39615850},
issn = {1879-1298},
abstract = {Freshwater microbial communities are integral components of riverine biodiversity. The ecological effects of toxic chemical pollutants, such as fungicides (e.g., tebuconazole), on microbial abundance and diversity are needed for risk assessment and regulation. The emergence of RNA metabarcoding approaches allow us to describe at unprecedented resolution the microbial diversity of the active part of a microbial community. Our study assesses the ecotoxicological impact of chronic and acute tebuconazole exposures on fungal, bacterial, and algal biomass and biodiversity of aquatic fungi and bacteria in stream biofilms using an RNA metabarcoding approach. In addition, the study uses HPLC-MS to evaluate the capability of biofilms to metabolize tebuconazole. Natural biofilm communities from a Swedish stream were exposed chronically (24 days) and acutely (96 hours) to environmental concentrations of tebuconazole (10 and 100 μg/L) in microcosms conditions. The diversity and community structure of fungi and bacteria was assessed by ITS2 and 16S cDNA amplicon-sequencing, respectively. Biofilms chronically exposed to tebuconazole produced and released unidentified transformation products into the water column, suggesting a biotransformation capability following 24 days of uninterrupted exposure. The fungal biomass markedly decreased by a biomass loss of 40% when chronically exposed to 10 μg/L, and 60% when chronically exposed to 100 μg/L. Bacterial and algal biomass remained comparable with the controls in all tebuconazole treatments. Fungal and bacterial alpha diversity metrics were not significantly impacted, although a decreasing trend in fungal richness was observed with the treatments. However, beta diversity was significantly impacted in both fungal and bacterial compartments. Chronic exposures resulted in a shift in community composition, where taxa potentially more tolerant to tebuconazole (i.e. Lecanoromycetes) replaced more sensitive taxa (i.e. Malasseziomycetes). This study indicates that tebuconazole at environmental concentrations might pose a risk to freshwater systems, mainly due to its high toxicity to fungi.},
}

@article {pmid39615760,
year = {2024},
author = {Ni, M and Pan, Y and Gong, J and Chen, Z and Li, D and Huang, Y and Li, L and Ding, Y and Bi, Z},
title = {Glycogen-accumulating organisms promote phosphate recovery from wastewater by pilot-scale biofilm sequencing batch reactor: Performance and mechanism.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {131910},
doi = {10.1016/j.biortech.2024.131910},
pmid = {39615760},
issn = {1873-2976},
abstract = {A high phosphate (P) recovery concentration was achieved in pilot-scale biofilm sequencing batch reactor (BSBR) with a low carbon source (C) cost. Especially, a high-abundance glycogen-accumulating organisms (GAOs) (13.93-31.72%) was detected that was accompanied by a high P recovery concentration of BSBR. High-abundance GAOs obtain additional C through various C compensation pathways (split tricarboxylic acid cycle (TCA cycle), glyoxylate shunt and gluconeogenesis), thus reducing the need to compete with polyphosphate-accumulating organisms (PAOs) for C and weakening the adverse effects on P recovery by PAO cells. Under the action of N-acyl homoserine lactones (AHLs)-mediated quorum sensing (QS), GAOs promoted the secretion of a large amount of extracellular polymeric substances (EPS), which helped to realize the P recovery of EPS-dominated biofilms (68.02%-96.89%). This study provides a low-carbon technology for the recovery of high concentration P from municipal wastewater, and improves the ecological theory of P recovery in collaboration with GAOs and PAOs.},
}

@article {pmid39615759,
year = {2024},
author = {Zhang, H and Zhang, J and Fan, S and Lu, J and Zhang, W and Ding, W},
title = {Synthetic biofilm community for efficient phosphorus removal from high-salinity wastewater.},
journal = {Bioresource technology},
volume = {418},
number = {},
pages = {131902},
doi = {10.1016/j.biortech.2024.131902},
pmid = {39615759},
issn = {1873-2976},
abstract = {Substantial amounts of phosphorus are discharged into water bodies, leading to an urgent need to develop methods for phosphorus removal. Here, 12 novel polyphosphate-accumulating organisms were identified from marine biofilms through genomic screening and incorporated into a stable community for phosphorus removal from high-salinity water. The synthetic biofilm community achieved an 82% removal efficiency in a marine broth medium. Electron microscopy showed storage of polyphosphate particles in the bacterial cells. Metatranscriptomic analysis indicated expression changes of genes for phosphate transport, as well as relevant metabolic pathways. In particular, pst genes encoding transporters with high phosphate affinity were downregulated at high-phosphorus concentration, whereas pit genes encoding transporters with low phosphate affinity were constitutively expressed. Furthermore, the synthetic biofilm community exhibited remarkable efficiency in removing over 92% of phosphorus from fish farming facility wastewater. Taken together, synthetic community using marine biofilm bacteria is a new strategy of phosphorus removal.},
}