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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

@article {pmid38636891,
year = {2024},
author = {Shaghayegh, G and Cooksley, C and Bouras, G and Panchatcharam, BS and Feizi, S and Javadian, S and Ramezanpour, M and Fenix, KA and Wormald, PJ and Psaltis, AJ and Vreugde, S},
title = {[1]S. aureus biofilm properties correlate with immune B cell subset frequencies and severity of chronic rhinosinusitis.},
journal = {Clinical immunology (Orlando, Fla.)},
volume = {},
number = {},
pages = {110221},
doi = {10.1016/j.clim.2024.110221},
pmid = {38636891},
issn = {1521-7035},
abstract = {Staphylococcus aureus mucosal biofilms are associated with recalcitrant chronic rhinosinusitis (CRS). However, S. aureus colonisation of sinus mucosa is frequent in the absence of mucosal inflammation. This questions the relevance of S. aureus biofilms in CRS etiopathogenesis. This study aimed to investigate whether strain-level variation in in vitro-grown S. aureus biofilm properties relates to CRS disease severity, in vitro toxicity, and immune B cell responses in sinonasal tissue from CRS patients and non-CRS controls. S. aureus clinical isolates, tissue samples, and matched clinical datasets were collected from CRS patients with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls. B cell responses in tissue samples were characterised by FACS. S. aureus biofilms were established in vitro, followed by measuring their properties of metabolic activity, biomass, colony-forming units, and exoprotein production. S. aureus virulence was evaluated using whole-genome sequencing, mass spectrometry and application of S. aureus biofilm exoproteins to air-liquid interface cultures of primary human nasal epithelial cells (HNEC-ALI). In vitro S. aureus biofilm properties were correlated with increased CRS severity scores, infiltration of antibody-secreting cells and loss of regulatory B cells in tissue samples. Biofilm exoproteins from S. aureus with high biofilm metabolic activity had enriched virulence genes and proteins, and negatively affected the barrier function of HNEC-ALI cultures. These findings support the notion of strain-level variation in S. aureus biofilms to be critical in the pathophysiology of CRS.},
}

@article {pmid38636465,
year = {2024},
author = {Rattanapakdeekul, N and Lapirattanakul, J and Tosrisawatkasem, O and Surarit, R and Smutkeeree, A},
title = {Evaluation of Streptococcus mutans biofilm formation and acidogenicity of infant milk formulas for treating cow milk allergy: An in vitro study.},
journal = {Caries research},
volume = {},
number = {},
pages = {},
doi = {10.1159/000538882},
pmid = {38636465},
issn = {1421-976X},
abstract = {INTRODUCTION: When infants cannot consume breast milk, the most commonly available alternative milk formula is cow milk-based. Due to a rise in the prevalence of cow milk protein allergy (CMPA) among children, this study aimed to assess the biofilm formation and acidogenicity of cow milk-based formulas as well as milk formulas suggested for children with CMPA.

METHODS: Cow milk-based formulas with 0%, 10%, or 18% sucrose added, partially hydrolyzed formula (pHF), extensively hydrolyzed formula (eHF), amino acid-based formula (AAF), and soy-based formulas with 0%, or 11% sucrose added were evaluated. Streptococcus mutans was used as a representative microorganism associated with caries. The acidogenicity after 24-h incubation was assessed by the pH of the formed biofilm and lactic acid formation. Biofilm formation was quantified using crystal violet staining. Additionally, the biofilm characteristics were determined using confocal laser scanning microscopy (CLSM). Comparisons were made among formulas without added sucrose to observe protein-based differences. Furthermore, formulas with different sucrose percentages were compared to explore the impact of sucrose content.

RESULTS: When comparing the formulas without added sucrose, the biofilm formation in the cow milk-based formula and pHF were significantly greater than the soy-based formula, eHF, and AAF. In the presence of S. mutans, all formulas reduced the biofilm pH below the critical enamel pH. The cow milk-based formula and AAF showed a significantly lower biofilm pH than the pHF, soy-based, and eHF groups, while the lactic acid production was markedly higher in the cow milk-based formula, pHF and AAF, compared with the eHF and soy-based formula. Adding sucrose into the cow milk-based and soy-based formulas substantially increased biofilm mass. The biofilm pH of the cow milk-based formulas, with or without sucrose, was significantly lower than that of the soy-based formulas. The CLSM indicated distinct biofilm characteristics among the different protein-based formulas, with sucrose supplementation promoting S. mutans aggregation in cow milk-based formula biofilm and increased density and intact biofilm in the soy-based formula.

CONCLUSION: All assessed milk formulas had caries-inducing factors, including those without supplemental sucrose. Among them, the eHF demonstrated the least caries-inducing factors, attributed to its minimal biofilm formation and the highest biofilm pH.},
}

@article {pmid38636417,
year = {2024},
author = {Liu, Y and Li, J and Su, J and Li, X and Li, X},
title = {Simultaneous removal of ammonia nitrogen, calcium and cadmium in a biofilm reactor based on microbial-induced calcium precipitation: Optimization of conditions, mechanism and community biological response.},
journal = {Journal of environmental management},
volume = {358},
number = {},
pages = {120912},
doi = {10.1016/j.jenvman.2024.120912},
pmid = {38636417},
issn = {1095-8630},
abstract = {With the enhancement of environmental governance regulations, the discharge requirements for reverse osmosis wastewater have become increasingly stringent. This study proposes an innovative approach utilizing heterotrophic nitrification and aerobic denitrification (HNAD)-based biomineralization technology, combined with coconut palm silk loaded biochar, to offer a novel solution for resource-efficient and eco-friendly treatment of reverse osmosis wastewater. Zobellella denitrificans sp. LX16 were loaded onto modified coir silk and showed removal efficiencies of up to 97.38, 94.58, 86.24, and 100% for NH4[+]-N (65 mg L[-1]), COD (900 mg L[-1]), Ca[2+] (180 mg L[-1]), and Cd[2+] (25 mg L[-1]). Analysis of the metabolites of microorganisms reveals that coconut palm silk loaded with deciduous biochar (BCPS) not only exerts a protective effect on microorganisms, but also enhances their growth, metabolism, and electron transfer capabilities. Characterization of precipitation phenomena elucidated the mechanism of Cd[2+] removal via ion exchange, precipitation, and adsorption. Employing high-throughput and KEGG functional analyses has confirmed the biota environmental response strategies and the identification of key genes like HNAD.},
}

@article {pmid38635841,
year = {2024},
author = {Youngblom, MA and Smith, TM and Murray, HJ and Pepperell, CS},
title = {Adaptation of the Mycobacterium tuberculosis transcriptome to biofilm growth.},
journal = {PLoS pathogens},
volume = {20},
number = {4},
pages = {e1012124},
doi = {10.1371/journal.ppat.1012124},
pmid = {38635841},
issn = {1553-7374},
abstract = {Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis (TB), is a leading global cause of death from infectious disease. Biofilms are increasingly recognized as a relevant growth form during M. tb infection and may impede treatment by enabling bacterial drug and immune tolerance. M. tb has a complicated regulatory network that has been well-characterized for many relevant disease states, including dormancy and hypoxia. However, despite its importance, our knowledge of the genes and pathways involved in biofilm formation is limited. Here we characterize the biofilm transcriptomes of fully virulent clinical isolates and find that the regulatory systems underlying biofilm growth vary widely between strains and are also distinct from regulatory programs associated with other environmental cues. We used experimental evolution to investigate changes to the transcriptome during adaptation to biofilm growth and found that the application of a uniform selection pressure resulted in loss of strain-to-strain variation in gene expression, resulting in a more uniform biofilm transcriptome. The adaptive trajectories of transcriptomes were shaped by the genetic background of the M. tb population leading to convergence on a sub-lineage specific transcriptome. We identified widespread upregulation of non-coding RNA (ncRNA) as a common feature of the biofilm transcriptome and hypothesize that ncRNA function in genome-wide modulation of gene expression, thereby facilitating rapid regulatory responses to new environments. These results reveal a new facet of the M. tb regulatory system and provide valuable insight into how M. tb adapts to new environments.},
}

@article {pmid38634060,
year = {2024},
author = {Lu, L and Zhao, Y and Li, M and Wang, X and Zhu, J and Liao, L and Wang, J},
title = {Contemporary strategies and approaches for characterizing composition and enhancing biofilm penetration targeting bacterial extracellular polymeric substances.},
journal = {Journal of pharmaceutical analysis},
volume = {14},
number = {4},
pages = {100906},
pmid = {38634060},
issn = {2214-0883},
abstract = {Extracellular polymeric substances (EPS) constitutes crucial elements within bacterial biofilms, facilitating accelerated antimicrobial resistance and conferring defense against the host's immune cells. Developing precise and effective antibiofilm approaches and strategies, tailored to the specific characteristics of EPS composition, can offer valuable insights for the creation of novel antimicrobial drugs. This, in turn, holds the potential to mitigate the alarming issue of bacterial drug resistance. Current analysis of EPS compositions relies heavily on colorimetric approaches with a significant bias, which is likely due to the selection of a standard compound and the cross-interference of various EPS compounds. Considering the pivotal role of EPS in biofilm functionality, it is imperative for EPS research to delve deeper into the analysis of intricate compositions, moving beyond the current focus on polymeric materials. This necessitates a shift from heavy reliance on colorimetric analytic methods to more comprehensive and nuanced analytical approaches. In this study, we have provided a comprehensive summary of existing analytical methods utilized in the characterization of EPS compositions. Additionally, novel strategies aimed at targeting EPS to enhance biofilm penetration were explored, with a specific focus on highlighting the limitations associated with colorimetric methods. Furthermore, we have outlined the challenges faced in identifying additional components of EPS and propose a prospective research plan to address these challenges. This review has the potential to guide future researchers in the search for novel compounds capable of suppressing EPS, thereby inhibiting biofilm formation. This insight opens up a new avenue for exploration within this research domain.},
}

@article {pmid38633196,
year = {2024},
author = {Mohammed, AR and El-Said, EI and Abd ElAal, SF and Kamal, RM},
title = {Screening of antibiogram, virulence factors, and biofilm production of Staphylococcus aureus and the bio-control role of some probiotics as alternative antibiotics.},
journal = {Open veterinary journal},
volume = {14},
number = {1},
pages = {176-185},
pmid = {38633196},
issn = {2218-6050},
abstract = {BACKGROUND: Food safety is a serious challenge in the face of increasing population and diminishing resources. Staphylococcus aureus is a critical foodborne pathogen characterized by its capability to secret a diverse range of heat-resistant enterotoxins. Antibiotic usage in dairy herds resulted in the occurrence of antimicrobial resistance (AMR) patterns among bacterial species, which were consequently transmitted to humans via dairy products. Lactic acid bacteria (LAB) produce bacteriocins, which provide an excellent source of natural antimicrobials with the further advantage of being environmentally friendly and safe.

AIM: Detection of multidrug resistance (MDR) S. aureus isolates in concerned samples, molecular characteristics, biofilm production, and the inhibitory role of LAB against it.

METHODS: Random samples of raw milk and other dairy products were analyzed for S. aureus isolation. Phenotypic and genotypic assessment of AMR was performed, in addition to detection of classical enterotoxin genes of S. aureus. Finally, evaluation of the antimicrobial action of some Lactobacillus strains against S. aureus.

RESULTS: Incidence rates of presumptive S. aureus in raw milk, Kariesh cheese, and yogurt samples were 50%, 40%, and 60%, respectively. The highest resistance of S. aureus was to Kanamycin (100%) and Nalidixic acid (89.3%), respectively. (78.66%) of S. aureus were MDR. 11.1% of S. aureus carried mecA gene. In concern with enterotoxins genes, PCR showed that examined isolates harbored sea with a percentage of (22.2%), while sed was found in (11.1%) of isolates. Regarding biofilm production, (88.88%) of S. aureus were biofilm producers. Finally, agar well diffusion showed that Lactobacillus acidophilus had the strongest antimicrobial action against S. aureus with inhibition zone diameter ranging from 18 to 22 mm.

CONCLUSION: There is a widespread prevalence of MDR S. aureus in raw milk and dairy products. Production of staphylococcal enterotoxins, as well as biofilm production are responsible for public health risks. Therefore, installing proper hygienic routines and harsh food safety policies at food chain levels is substantial.},
}

@article {pmid38633171,
year = {2024},
author = {Elshazely, RMY and Amer, IH and Aal, SFAA and Aal, SFAA and Tahoun, ABMB},
title = {Antibacterial effect of Moringa oleifera on Staphylococcus aureus and Pseudomonas aeruginosa isolated from raw milk and some dairy products with special reference to biofilm gene expression.},
journal = {Open veterinary journal},
volume = {14},
number = {1},
pages = {164-175},
pmid = {38633171},
issn = {2218-6050},
abstract = {BACKGROUND: Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) are well defined as food poisoning pathogens that are highly resistant and need continuous studies.

AIM: The purpose of the work was to examine phenotypic and genotypic characteristics of both P. aeruginosa and S. aureus, and treatment trials with medicinal plants.

METHODS: Samples were examined for isolation of P. aeruginosa and S. aureus on selective media followed by biochemical confirmation, biofilm formation, genes detection, and expression of P. aeruginosa pslA biofilm gene was performed by quantitative real-time polymerase chain reaction after treatment with 0.312 mg/ml Moringa oleifera aqueous extract as a minimum inhibitory concentration.

RESULTS: The highest isolation rate of P. aeruginosa was 20% from both raw milk and Kariesh cheese, followed by 16% and 12% from ice cream and processed cheese, respectively, while the highest isolation rate of S. aureus was 36% from raw milk followed by 28% in ice cream and 16% in both Kariesh cheese and processed cheese. 30% of P. aeruginosa isolates were biofilm producers, while only 21% of S. aureus isolates were able to produce biofilm. The P. aeruginosa isolates harbor virulence-associated genes nan1, exoS, toxA, and pslA at 100%, 80%, 40%, and 40%, respectively. Staphylococcus aureus SEs genes were examined in S. aureus strains, where SEA and SEB genes were detected with 60%, but no isolate harbored SEC, SED, or SEE. The significant fold change of P. aeruginosa pslA expression was 0.40332 after treatment with M. oleifera aqueous extract.

CONCLUSION: Pseudomonas aeruginosa and S. aureus harbor dangerous virulence genes that cause food poisoning, but M. oleifera extract could minimize their action.},
}

@article {pmid38629727,
year = {2024},
author = {Xue, Y and Yu, C and Ouyang, H and Huang, J and Kang, X},
title = {Uncovering the Molecular Composition and Architecture of the Bacillus subtilis Biofilm via Solid-State NMR Spectroscopy.},
journal = {Journal of the American Chemical Society},
volume = {},
number = {},
pages = {},
doi = {10.1021/jacs.4c00889},
pmid = {38629727},
issn = {1520-5126},
abstract = {The complex and dynamic compositions of biofilms, along with their sophisticated structural assembly mechanisms, endow them with exceptional capabilities to thrive in diverse conditions that are typically unfavorable for individual cells. Characterizing biofilms in their native state is significantly challenging due to their intrinsic complexities and the limited availability of noninvasive techniques. Here, we utilized solid-state nuclear magnetic resonance (NMR) spectroscopy to analyze Bacillus subtilis biofilms in-depth. Our data uncover a dynamically distinct organization within the biofilm: a dominant, hydrophilic, and mobile framework interspersed with minor, rigid cores of limited water accessibility. In these heterogeneous rigid cores, the major components are largely self-assembled. TasA fibers, the most robust elements, further provide a degree of mechanical support for the cell aggregates and some lipid vesicles. Notably, rigid cell aggregates can persist even without the major extracellular polymeric substance (EPS) polymers, although this leads to slight variations in their rigidity and water accessibility. Exopolysaccharides are exclusively present in the mobile domain, playing a pivotal role in its water retention property. Specifically, all water molecules are tightly bound within the biofilm matrix. These findings reveal a dual-layered defensive strategy within the biofilm: a diffusion barrier through limited water mobility in the mobile phase and a physical barrier posed by limited water accessibility in the rigid phase. Complementing these discoveries, our comprehensive, in situ compositional analysis is not only essential for delineating the sophisticated biofilm architecture but also reveals the presence of alternative genetic mechanisms for synthesizing exopolysaccharides beyond the known pathway.},
}

@article {pmid38629215,
year = {2024},
author = {Quan, K and Mao, Z and Lu, Y and Qin, Y and Wang, S and Yu, C and Bi, X and Tang, H and Ren, X and Chen, D and Cheng, Y and Wang, Y and Zheng, Y and Xia, D},
title = {Composited silk fibroins ensured adhesion stability and magnetic controllability of Fe3O4-nanoparticle coating on implant for biofilm treatment.},
journal = {Materials horizons},
volume = {},
number = {},
pages = {},
doi = {10.1039/d4mh00097h},
pmid = {38629215},
issn = {2051-6355},
abstract = {Magnetic propulsion of nano-/micro-robots is an effective way to treat implant-associated infections by physically destroying biofilm structures to enhance antibiotic killing. However, it is hard to precisely control the propulsion in vivo. Magnetic-nanoparticle coating that can be magnetically pulled off does not need precise control, but the requirement of adhesion stability on an implant surface restricts its magnetic responsiveness. Moreover, whether the coating has been fully pulled-off or not is hard to ensure in real-time in vivo. Herein, composited silk fibroins (SFMA) are optimized to stabilize Fe3O4 nanoparticles on a titanium surface in a dry environment; while in an aqueous environment, the binding force of SFMA on titanium is significantly reduced due to hydrophilic interaction, making the coating magnetically controllable by an externally-used magnet but still stable in the absence of a magnet. The maximum working distance of the magnet can be calculated using magnetomechanical simulation in which the yielding magnetic traction force is strong enough to pull Fe3O4 nanoparticles off the surface. The pulling-off removes the biofilms that formed on the coating and enhances antibiotic killing both in vitro and in a rat sub-cutaneous implant model by up to 100 fold. This work contributes to the practical knowledge of magnetic propulsion for biofilm treatment.},
}

@article {pmid38628638,
year = {2024},
author = {Shariati, A and Noei, M and Askarinia, M and Khoshbayan, A and Farahani, A and Chegini, Z},
title = {Inhibitory effect of natural compounds on quorum sensing system in Pseudomonas aeruginosa: a helpful promise for managing biofilm community.},
journal = {Frontiers in pharmacology},
volume = {15},
number = {},
pages = {1350391},
pmid = {38628638},
issn = {1663-9812},
abstract = {Pseudomonas aeruginosa biofilm is a community of bacteria that adhere to live or non-living surfaces and are encapsulated by an extracellular polymeric substance. Unlike individual planktonic cells, biofilms possess a notable inherent resistance to sanitizers and antibiotics. Overcoming this resistance is a substantial barrier in the medical and food industries. Hence, while antibiotics are ineffective in eradicating P. aeruginosa biofilm, scientists have explored alternate strategies, including the utilization of natural compounds as a novel treatment option. To this end, curcumin, carvacrol, thymol, eugenol, cinnamaldehyde, coumarin, catechin, terpinene-4-ol, linalool, pinene, linoleic acid, saponin, and geraniol are the major natural compounds extensively utilized for the management of the P. aeruginosa biofilm community. Noteworthy, the exact interaction of natural compounds and the biofilm of this bacterium is not elucidated yet; however, the interference with the quorum sensing system and the inhibition of autoinducer production in P. aeruginosa are the main possible mechanisms. Noteworthy, the use of different drug platforms can overcome some drawbacks of natural compounds, such as insolubility in water, limited oral bioavailability, fast metabolism, and degradation. Additionally, drug platforms can deliver different antibiofilm agents simultaneously, which enhances the antibiofilm potential of natural compounds. This article explores many facets of utilizing natural compounds to inhibit and eradicate P. aeruginosa biofilms. It also examines the techniques and protocols employed to enhance the effectiveness of these compounds.},
}

@article {pmid38626650,
year = {2024},
author = {Si, B and Yang, Y and Naveed, M and Wang, F and Chan, MWH},
title = {Characterizations of biogenic selenium nanoparticles and their anti-biofilm potential against Streptococcus mutans ATCC 25175.},
journal = {Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS)},
volume = {84},
number = {},
pages = {127448},
doi = {10.1016/j.jtemb.2024.127448},
pmid = {38626650},
issn = {1878-3252},
abstract = {INTRODUCTION: S. mutans has been identified as the primary pathogenic bacterium in biofilm-mediated dental caries. The biogenic selenium nanoparticles (SeNPs) produced by L. plantarum KNF-5 were used in this study against S. mutans ATCC 25175.

OBJECTIVES: The aims of this study were: (1) the biosynthesis of SeNPs by L. plantarum KNF-5, (2) the characterization of SeNPs, (3) the investigation of the inhibitory effect of biogenic SeNPs against S. mutans ATCC 25175, and (4) the determination of the anti-biofilm potential of SeNPS against S. mutans ATCC 25175.

METHODOLOGY: 3 mL of the culture was added to 100 mL of MRS medium and incubated. After 4 h, Na2SeO3 solution (concentration 100 μg/mL) was added and incubated at 37 °C for 36 h. The color of the culture solution changed from brownish-yellow to reddish, indicating the formation of SeNPs. The characterization of SeNPs was confirmed by UV-Vis spectrophotometry, FTIR, SEM-EDS and a particle size analyzer. The antibacterial activity was determined by the disk diffusion method, the MIC by the micro-double dilution method, and the biofilm inhibitory potential by the crystal violet method and the MTT assay. The effect of SeNPs on S. mutans ATCC 25175 was determined using SEM and CLSM spectrometry techniques. The sulfate-anthrone method was used to analyze the effect of SeNPs on insoluble extracellular polysaccharides. The expression of genes in S. mutans ATCC 25175 was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR).

PREPARATION OF NANOPARTICLES: SeNPs produced by probiotic bacteria are considered a safe method. In this study, L. plantarum KNF-5 (probiotic strain) was used for the production of SeNPs.

RESULTS: The biogenic SeNPs were spherical and coated with proteins and polysaccharides and had a diameter of about 270 nm. The MIC of the SeNPs against S. mutans ATCC 25175 was 3.125 mg/mL. Biofilm growth was also significantly suppressed at this concentration. The expression of genes responsible for biofilm formation (GtfB, GtfC, BrpA and GbpB,) was reduced when S. mutans ATCC 25175 was treated with SeNPs.

CONCLUSION: It was concluded that the biogenic SeNPs produced by L. plantarum KNF-5 was highly effective to inhibit the growth of S. mutans ATCC 25175.

NOVELTY STATEMENT: The application of biogenic SeNPs, a natural anti-biofilm agent against S. mutans ATCC 25175. In the future, this study will provide a new option for the prevention and treatment of dental caries.},
}

@article {pmid38625517,
year = {2024},
author = {Piecuch, A and Cal, M and Ogórek, R},
title = {Adhesion and biofilm formation by two clinical isolates of Trichosporon Cutaneum in various environmental conditions.},
journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]},
volume = {},
number = {},
pages = {},
pmid = {38625517},
issn = {1678-4405},
support = {2020/04/X/NZ9/00644//Narodowe Centrum Nauki/ ; },
abstract = {Trichosporon spp. is an emerging opportunistic pathogen and a common cause of both superficial and invasive infections. Although Trichosporon asahii is the most frequently isolated species, Trichosporon cutaneum is also widely observed, as it is the predominant agent in cases of white Piedra and onychomycosis. Trichosporon spp. is a known to produce biofilms, which serve as one of its virulence mechanisms, however, there is limited data available on biofilms formed by T. cutaneum. Thus, the aim of this study was to assess the adhesion and biofilm formation of two clinical isolates of T. cutaneum under various environmental conditions (including temperature, nutrient availability, and carbon source), as well as their tolerance to fluconazole. Adhesion was tested on common abiotic substrates (such as silicone, glass, and stainless steel), revealing that T. cutaneum readily adhered to all surfaces tested. CV staining was applied for the evaluation of the environment influence on biofilm efficiency and it was proved that the nutrient availability has a major impact. Additionaly, fluorescent staining was employed to visualize the morphology of T. cutaneum biofilm and its survival in the presence of fluconazole. Hyphae production was shown to play a role in elevated biofilm production in minimal medium and increased tolerance to fluconazole.},
}

@article {pmid38625380,
year = {2024},
author = {Hayatimehr, S and Mirkalantari, S and Amirmozafari, N and Jazi, FM and Moghadam, MT},
title = {Virulence Genes and Biofilm Formation Among Legionella pneumophila Isolates Collected from Hospital Water Sources.},
journal = {Current microbiology},
volume = {81},
number = {6},
pages = {141},
pmid = {38625380},
issn = {1432-0991},
mesh = {Humans ; *Legionella pneumophila/genetics ; Virulence/genetics ; Chlorine/pharmacology ; Iran ; *Legionella ; Biofilms ; Hospitals ; },
abstract = {Legionella pneumophila can be transmitted to people, especially immunocompromised patients, via hospital water pipe systems and cause severe pneumonia. The aim of our study was to investigate the presence of major virulence factor genes, ability of biofilms formation, and correlation between presence of Legionella isolates and temperature, pH, and residual chlorine of water. Hundred water samples were collected from nine hospitals in Tehran, Iran. Temperature, pH, and residual chlorine were determined during sampling. Different virulence genes and the ability to form biofilms were subsequently analyzed among the L. pneumophila isolates. Results showed that 12 (12%) samples were positive in culture method and all of the isolates were positive as L. pneumophila species (mip). A correlation was found between Legionella culture positivity and temperature and pH of water, but there was no significant correlation between residual chlorine of water samples and the presence of Legionella. The isolation of Legionella rate in summer and spring was higher than winter and autumn. Twelve (100%) isolates were positive for mip genes, 9 (75%) for dot genes, 8 (66.66%) for hsp, 6 (50%) for lvh, and 4 (33.33%) for rtx. All of the isolates displayed strong ability for biofilm production every three days. Two of these isolates (16.6%) displayed weak ability to form biofilm on the first day of incubation. This study revealed that water sources in hospitals were colonized by virulent Legionella and should be continuously monitored to avoid elevated concentrations of Legionella with visible biofilm formation.},
}

Humans
*Legionella pneumophila/genetics
Virulence/genetics
Chlorine/pharmacology
Iran
*Legionella
Biofilms
Hospitals

@article {pmid38625018,
year = {2024},
author = {Ma, Z and Sun, Y and Liu, Y and Jiao, J and Li, N and Zuo, Y and Li, Z and Li, Y and Cai, X and Meng, Q and Qiao, J},
title = {STM1863, a Member of the DUFs Protein Family, Is Involved in Environmental Adaptation, Biofilm Formation, and Virulence in Salmonella Typhimurium.},
journal = {Foodborne pathogens and disease},
volume = {},
number = {},
pages = {},
doi = {10.1089/fpd.2023.0139},
pmid = {38625018},
issn = {1556-7125},
abstract = {Salmonella Typhimurium (STM) is an important zoonotic Gram-negative pathogen that can cause infection in a variety of livestock and poultry. Meanwhile, as an important foodborne pathogen, the bacterium can survive in various stressful environments and transmits through the fecal-oral route, posing a serious threat to global food safety. To investigate the roles of STM1863, a member of the DUFs protein family, involved in STM environmental adaptation, biofilm formation, and virulence. We analyzed the molecular characteristics of the protein encoded by STM1863 gene and examined intra- and extracellular expression levels of STM1863 gene in mouse macrophages. Furthermore, we constructed STM1863 gene deletion and complementation strains and determined its environmental adaptation under stressful conditions such as acid, alkali, high salt, bile salt, and oxidation. And the capacity of biofilm formation and pathogenicity of those strains were analyzed and compared. In addition, the interaction between the promoter of STM1863 gene and RcsB protein was analyzed using DNA gel electrophoresis migration assay (electrophoretic mobility shift assay [EMSA]). The experiments revealed that acid adaptability and biofilm formation ability of STM1863 gene deletion strain were significantly weakened compared with the parental and complementary strains. Moreover, the adhesion and invasion ability of STM1863 deletion strain to mouse macrophages was significantly decreased, while the median lethal dose (LD50) increased by 2.148-fold compared with the parental strain. In addition, EMSA confirmed that RcsB protein could bind to the promoter sequence of STM1863 gene, suggesting that the expression of STM1863 gene might be modulated by RcsB. The present study demonstrated for the first time that STM1863, a member of the DUFs protein family, is involved in the modulation of environmental adaptation, biofilm formation, and virulence.},
}

@article {pmid38624207,
year = {2024},
author = {Banerjee, A and Kang, C-Y and An, M and Koff, BB and Sunder, S and Kumar, A and Tenuta, LMA and Stockbridge, RB},
title = {Fluoride export is required for the competitive fitness of pathogenic microorganisms in dental biofilm models.},
journal = {mBio},
volume = {},
number = {},
pages = {e0018424},
doi = {10.1128/mbio.00184-24},
pmid = {38624207},
issn = {2150-7511},
abstract = {UNLABELLED: Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species Streptococcus mutans and Candida albicans extrude intracellular fluoride using a CLC[F] F[-]/H[+] antiporter and FEX fluoride channel, respectively, whereas oral commensal eubacteria, such as Streptococcus gordonii, export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using S. mutans with the genetic knockout of the CLC[F] transporter, exposure to low fluoride concentrations decreased S. mutans counts, synergistically reduced the populations of C. albicans, increased the relative proportion of oral commensal S. gordonii, and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with C. albicans with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride but to a lesser degree. Imaging studies indicate that S. mutans is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time. Biochemical purification of the S. mutans CLC[F] transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms and that S. mutans is especially susceptible to fluoride toxicity.

IMPORTANCE: Dental caries is a globally prevalent condition that occurs when pathogenic species, including Streptococcus mutans and Candida albicans, outcompete beneficial species, such as Streptococcus gordonii, in the dental biofilm. Fluoride is routinely used in oral hygiene to prevent dental caries. Fluoride also has antimicrobial properties, although most microbes possess fluoride exporters to resist its toxicity. This work shows that sensitization of cariogenic species S. mutans and C. albicans to fluoride by genetic knockout of fluoride exporters alters the microbial composition and pathogenic properties of dental biofilms. These results suggest that the development of drugs that inhibit fluoride exporters could potentiate the anticaries effect of fluoride in over-the-counter products like toothpaste and mouth rinses. This is a novel strategy to treat dental caries.},
}

@article {pmid38622845,
year = {2024},
author = {Priyadarshini, E and Kumar, R and Balakrishnan, K and Pandit, S and Kumar, R and Jha, NK and Gupta, PK},
title = {Biofilm Inhibition on Medical Devices and Implants Using Carbon Dots: An Updated Review.},
journal = {ACS applied bio materials},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsabm.4c00024},
pmid = {38622845},
issn = {2576-6422},
abstract = {Biofilms are an intricate community of microbes that colonize solid surfaces, communicating via a quorum-sensing mechanism. These microbial aggregates secrete exopolysaccharides facilitating adhesion and conferring resistance to drugs and antimicrobial agents. The escalating global concern over biofilm-related infections on medical devices underscores the severe threat to human health. Carbon dots (CDs) have emerged as a promising substrate to combat microbes and disrupt biofilm matrices. Their numerous advantages such as facile surface functionalization and specific antimicrobial properties, position them as innovative anti-biofilm agents. Due to their minuscule size, CDs can penetrate microbial cells, inhibiting growth via cytoplasmic leakage, reactive oxygen species (ROS) generation, and genetic material fragmentation. Research has demonstrated the efficacy of CDs in inhibiting biofilms formed by key pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Consequently, the development of CD-based coatings and hydrogels holds promise for eradicating biofilm formation, thereby enhancing treatment efficacy, reducing clinical expenses, and minimizing the need for implant revision surgeries. This review provides insights into the mechanisms of biofilm formation on implants, surveys major biofilm-forming pathogens and associated infections, and specifically highlights the anti-biofilm properties of CDs emphasizing their potential as coatings on medical implants.},
}

@article {pmid38621525,
year = {2024},
author = {Sampaio, C and Méndez, DAC and Buzalaf, MAR and Pessan, JP and Cruvinel, T},
title = {Arginine and sodium fluoride affect the microbial composition and reduce biofilm metabolism and enamel mineral loss in an oral microcosm model.},
journal = {Journal of dentistry},
volume = {},
number = {},
pages = {104997},
doi = {10.1016/j.jdent.2024.104997},
pmid = {38621525},
issn = {1879-176X},
abstract = {OBJECTIVE: To assess the effects of arginine, with or without sodium fluoride (NaF; 1,450 ppm), on saliva-derived microcosm biofilms and enamel demineralization.

METHODS: Saliva-derived biofilms were grown on bovine enamel blocks in 0.2% sucrose-containing modified McBain medium, according to six experimental groups: control (McBain 0.2%); 2.5% arginine; 8% arginine; NaF; 2.5% arginine with NaF; and 8% arginine with NaF. After 5 days of growth, biofilm viability was assessed by colony-forming units counting, laser scanning confocal microscopy was used to determine biofilm vitality and extracellular polysaccharide (EPS) production, while biofilm metabolism was evaluated using the resazurin assay and lactic acid quantification. Demineralization was evaluated by measuring pH in the culture medium and calcium release. Data were analyzed by Kruskal-Wallis' and Dunn's tests (p<0.05).

RESULTS: 8% arginine with NaF showed the strongest reduction in total streptococci and total microorganism counts, with no significant difference compared to arginine without NaF. Neither 2.5% arginine alone nor NaF alone significantly reduced microbial counts compared to the control, although in combination, a reduction in all microbial groups was observed. Similar trends were found for biofilm vitality and EPS, and calcium released to the growth medium.

CONCLUSIONS: 8% Arginine, with or without NaF, exhibited the strongest antimicrobial activity and reduced enamel calcium loss. Also, NaF enhanced the effects of 2.5% arginine, yielding similar results to 8% arginine for most parameters analyzed.

CLINICAL SIGNIFICANCE: The results provided further evidence on how arginine, with or without NaF, affects oral microcosm biofilms and enamel mineral loss.},
}

@article {pmid38621382,
year = {2024},
author = {Chaudhary, K and Agrahari, B and Biswas, B and Chatterjee, N and Chaudhary, A and Kumar, A and Sonkar, H and Dewan, S and Saxena, D and Akhir, A and Malhotra, N and Chopra, S and Misra, S and Matheswaran, S and Singh, RG},
title = {Pyridine-2,6-dicarboxamide proligands and their Cu(II)/Zn(II) complexes Targeting Staphylococcus Aureus for the Attenuation of In-vivo Dental Biofilm.},
journal = {Advanced healthcare materials},
volume = {},
number = {},
pages = {e2400378},
doi = {10.1002/adhm.202400378},
pmid = {38621382},
issn = {2192-2659},
abstract = {In the pursuit to combat stubborn bacterial infections, particularly those stemming from gram-positive bacteria, our study is an attempt to craft a precision-driven platform characterized by unparalleled selectivity, specificity, and synergistic antimicrobial mechanisms. Leveraging remarkable potential of metalloantibiotics in antimicrobial applications, herein, we rationally design, synthesize, and characterize a new library of Pyridine-2,6-dicarboxamide ligands and their corresponding transition metal Cu(II)/Zn(II) complexes. The lead compound L[11] demonstrate robust antibacterial properties against Staphylococcus aureus (MIC = 2-16 µg/mL), methicillin and vancomycin-resistant S. aureus (MIC = 2-4 µg/mL) and exhibit superior antibacterial activity when compared to FDA-approved vancomycin, the drug of last resort. Additionally, the compound exhibited notable antimicrobial efficacy against resistant enterococcus strains (MIC = 2-8 µg/mL). To unravel mechanistic profile, advanced imaging techniques including SEM and AFM were harnessed, collectively suggesting a mechanistic pathway involving cell wall disruption. Live/dead fluorescence studies further confirm efficacy of L[11] and its complexes against S. aureus membranes. Our translational exploration extends to a rat model, indicating promising In-vivo therapeutic potential. Thus, our comprehensive research initiative has capabilities to transcends the confines of our laboratory, heralding a pivotal step toward combatting antibiotic-resistant pathogens and advancing the frontiers of metalloantibiotics based therapy with a profound clinical implication. This article is protected by copyright. All rights reserved.},
}

@article {pmid38621130,
year = {2024},
author = {Postek, W and Staśkiewicz, K and Lilja, E and Wacław, B},
title = {Substrate geometry affects population dynamics in a bacterial biofilm.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {121},
number = {17},
pages = {e2315361121},
doi = {10.1073/pnas.2315361121},
pmid = {38621130},
issn = {1091-6490},
support = {UMO-2019/02/H/NZ6/00003//Narodowe Centrum Nauki (NCN)/ ; PPN/PPO/2019/1/ 00030 /U/0001//Narodowa Agencja Wymiany Akademickiej (NAWA)/ ; PPN/BEK/2020/1/00333/U/00001//Narodowa Agencja Wymiany Akademickiej (NAWA)/ ; 069.2021//Fundacja na rzecz Nauki Polskiej (FNP)/ ; },
abstract = {Biofilms inhabit a range of environments, such as dental plaques or soil micropores, often characterized by noneven surfaces. However, the impact of surface irregularities on the population dynamics of biofilms remains elusive, as most experiments are conducted on flat surfaces. Here, we show that the shape of the surface on which a biofilm grows influences genetic drift and selection within the biofilm. We culture Escherichia coli biofilms in microwells with a corrugated bottom surface and observe the emergence of clonal sectors whose size corresponds to that of the corrugations, despite no physical barrier separating different areas of the biofilm. The sectors are remarkably stable and do not invade each other; we attribute this stability to the characteristics of the velocity field within the biofilm, which hinders mixing and clonal expansion. A microscopically detailed computer model fully reproduces these findings and highlights the role of mechanical interactions such as adhesion and friction in microbial evolution. The model also predicts clonal expansion to be limited even for clones with a significant growth advantage-a finding which we confirm experimentally using a mixture of antibiotic-sensitive and antibiotic-resistant mutants in the presence of sublethal concentrations of the antibiotic rifampicin. The strong suppression of selection contrasts sharply with the behavior seen in range expansion experiments in bacterial colonies grown on agar. Our results show that biofilm population dynamics can be affected by patterning the surface and demonstrate how a better understanding of the physics of bacterial growth can be used to control microbial evolution.},
}

@article {pmid38619862,
year = {2024},
author = {Tian, Y and Zhong, F and Shang, N and Yu, H and Mao, D and Huang, X},
title = {Maize root exudates promote Bacillus sp. Za detoxification of diphenyl ether herbicides by enhancing colonization and biofilm formation.},
journal = {Molecular plant-microbe interactions : MPMI},
volume = {},
number = {},
pages = {},
doi = {10.1094/MPMI-02-24-0020-R},
pmid = {38619862},
issn = {0894-0282},
abstract = {Diphenyl ether herbicides are extensively utilized in agricultural systems, but their residues threaten the health of sensitive rotation crops. Functional microbial strains can degrade diphenyl ether herbicides in the rhizosphere of crops, facilitating the restoration of a healthy agricultural environment. However, the interplay between microorganisms and plants in diphenyl ether herbicides degradation remains unclear. Thus, the herbicide-degrading strain Bacillus sp. Za and the sensitive crop, maize, were employed to uncover the interaction mechanism. The degradation of diphenyl ether herbicides by strain Bacillus sp. Za was promoted by root exudates. The strain induced root exudates re-secretion in diphenyl ether herbicide-polluted maize. We further showed that root exudates enhanced the rhizosphere colonization and the biofilm biomass of strain Za, augmenting its capacity to degrade diphenyl ether herbicide. Root exudates regulated gene fliZ, pivotal in biofilm formation. Wild-type strain Za significantly reduced herbicide toxicity to maize compared to the ZaΔfliZ mutant. Moreover, root exudates promoted strain Za growth and chemotaxis, which was related to biofilm formation. This mutualistic relationship between the microorganisms and the plants demonstrates the significance of plant-microbe interactions in shaping diphenyl ether herbicide degradation in rhizosphere soils.},
}

@article {pmid38619794,
year = {2024},
author = {Van Holm, W and Zayed, N and Lauwens, K and Saghi, M and Axelsson, J and Aktan, MK and Braem, A and Simoens, K and Vanbrabant, L and Proost, P and Van Holm, B and Maes, P and Boon, N and Bernaerts, K and Teughels, W},
title = {Oral Biofilm Composition, Dissemination to Keratinocytes, and Inflammatory Attenuation Depend on Probiotic and Synbiotic Strain Specificity.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {38619794},
issn = {1867-1314},
support = {C24/17/086//KU Leuven/ ; C16/17/010//KU Leuven/ ; C16/17/010//KU Leuven/ ; C24/17/086//KU Leuven/ ; G091218N//Fonds Wetenschappelijk Onderzoek/ ; G091218N//Fonds Wetenschappelijk Onderzoek/ ; },
abstract = {Several inflammatory diseases are characterized by a disruption in the equilibrium between the host and its microbiome. Due to the increase in resistance, the use of antibiotics for the widespread, nonspecific killing of microorganisms is at risk. Pro-microbial approaches focused on stimulating or introducing beneficial species antagonistic toward pathobionts may be a viable alternative for restoring the host-microbiome equilibrium. Unfortunately, not all potential probiotic or synbiotic species and even subspecies (to strain level) are equally effective for the designated pathology, leading to conflicting accounts of their efficacy. To assess the extent of these species- and strain-specific effects, 13 probiotic candidates were evaluated for their probiotic and synbiotic potential with glycerol on in vitro oral biofilms, dissemination from biofilms to keratinocytes, and anti-inflammatory activity. Species- and strain-specific effects and efficacies were observed in how they functioned as probiotics or synbiotics by influencing oral pathobionts and commensals within biofilms and affected the dissemination of pathobionts to keratinocytes, ranging from ineffective strains to strains that reduced pathobionts by 3 + log. In addition, a minority of the candidates exhibited the ability to mitigate the inflammatory response of LPS-stimulated monocytes. For a comprehensive assessment of probiotic therapy for oral health, a judicious selection of fully characterized probiotic strains that are specifically tailored to the designated pathology is required. This approach aims to challenge the prevailing perception of probiotics, shifting the focus away from "form over function." Rather than using unproven, hypothetical probiotic strains from known genera or species, one should choose strains that are actually functional in resolving the desired pathology before labelling them probiotics.},
}

@article {pmid38618300,
year = {2024},
author = {Berk Ergun, Ş and Has, EG and Akçelik, N and Akçelik, M},
title = {Characteristics of Bacterial Biofilm Formation in Nasolacrimal Silicone Tubes Post-dacryocystorhinostomy.},
journal = {Cureus},
volume = {16},
number = {3},
pages = {e56112},
pmid = {38618300},
issn = {2168-8184},
abstract = {PURPOSE: To examine the biofilm formation characteristics of bacteria identified at the genus level in samples obtained from silicone tubes after dacryocystorhinostomy surgery.

METHODS: In the study involving consecutive patients who underwent dacryocystorhinostomy surgery at Ankara Bilkent City Hospital and whose silicone tubes were removed six months after surgery, between January 2023 and May 2023; the tubes were placed in glycerol-PBS (phosphate buffered saline) solution and cultured on descriptive selective media at the genus level. The biofilm-forming properties of the obtained isolates were examined in solid-air and liquid-air interphases. Salmonella Typhimurium ATCC SL1344 strain was used as the control bacterium.

RESULTS: As a result of the analysis of the samples taken from the patients, Pseudomonas spp. was identified in three of the samples, Staphylococcus spp. in five of the samples, and Streptococcus spp. in one of the samples. Among these samples, except for the bacteria identified in samples one and five, the rest were found to be strong biofilm producers. In all strong biofilm producers, the maximum biofilm production time was determined as 72 h and the incubation temperature was 37°C. The presence of cellulose and amyloid proteins in biofilm matrix structures is identified. Swimming and swarming motilities were observed in all bacterial samples.

CONCLUSION: Since biofilms are considered potential factors in the pathogenesis of infectious and inflammatory diseases, they are a subject that needs to be thoroughly investigated. In our study, although there were no clinical infections in any of the patients, biofilm formation was detected in the patient samples. The fact that the bacteria exhibited moderate to strong biofilm formation characteristics suggests that these microorganisms could be persistent infectious agents.},
}

@article {pmid38616595,
year = {2024},
author = {Shah, PK and Bhandari, N and Tamang, B and Joshi, RD},
title = {Antibiotic Susceptibility and Biofilm Production among Coagulase Negative Staphylococci Isolated from Clinical Samples at Tertiary Care Hospital.},
journal = {Journal of Nepal Health Research Council},
volume = {21},
number = {4},
pages = {636-641},
doi = {10.33314/jnhrc.v21i4.4894},
pmid = {38616595},
issn = {1999-6217},
abstract = {BACKGROUND: Coagulase Negative Staphylococci have been widely associated with medical device implant treatment and immune-compromised patients. Despite having increasing interest in Coagulase Negative Staphylococci, few studies from Nepal have reported the association of these organisms with urinary tract infections, conjunctivitis, high vaginal swabs, and cerebrospinal fluid. This study was carried out to determine antibiotic susceptibility pattern and biofilm production among Coagulase Negative Staphylococci isolated from clinical samples at tertiary care hospital.

METHODS: This study was a hospital based cross-sectional study in which 3690 clinical samples were included. Isolation and identification of isolates was done following standard microbiological protocol. Coagulase Negative Staphylococci were identified phenotypically on the basis of gram staining, slide and tube coagulase test and by various sugar fermentation tests. Antibiotic susceptibility test was done following Kirby Bauer disk diffusion method (Clinical and Laboratory Standards Institute 2020). Biofilm production was determined by Tissue Culture Plate technique.

RESULTS: A total of 113 isolates of Coagulase Negative Staphylococci were detected. Among them S. epidermidis (45.1%), S. saprophyticus (23.9%), S. haemolyticus (16.8%), S. hominis (5.3%), S. capitis (2.7%), -----S. cohini (1.8%), S. lugdunensis (1.8%) and S. sciuri (2.7%) were identified phenotypically. All isolates were found to be resistant against Ampicillin and 111 (98.2%) were sensitive against Linezolid.23.9% of CoNS were strong biofilm producers, 19.5% moderate and 56.6 % were non/weak biofilm producers.

CONCLUSIONS: It requires susceptibility test for prescribing antibiotics against Coagulase Negative Staphylococci in hospital and the misuse of antibiotics should be prevented.},
}

@article {pmid38616221,
year = {2024},
author = {Srivastava, A and Verma, N and Kumar, V and Apoorva, P and Agarwal, V},
title = {Biofilm inhibition/eradication: exploring strategies and confronting challenges in combatting biofilm.},
journal = {Archives of microbiology},
volume = {206},
number = {5},
pages = {212},
pmid = {38616221},
issn = {1432-072X},
abstract = {Biofilms are complex communities of microorganisms enclosed in a self-produced extracellular matrix, posing a significant threat to different sectors, including healthcare and industry. This review provides an overview of the challenges faced due to biofilm formation and different novel strategies that can combat biofilm formation. Bacteria inside the biofilm exhibit increased resistance against different antimicrobial agents, including conventional antibiotics, which can lead to severe problems in livestock and animals, including humans. In addition, biofilm formation also imposes heavy economic pressure on industries. Hence it becomes necessary to explore newer alternatives to eradicate biofilms effectively without applying selection pressure on the bacteria. Excessive usage of antibiotics may also lead to an increase in the number of resistant strains as bacteria employ an advanced antimicrobial resistance mechanism. This review provides insight into multifaceted technologies like quorum sensing inhibition, enzymes, antimicrobial peptides, bacteriophage, phytocompounds, and nanotechnology to neutralize biofilms without developing antimicrobial resistance (AMR). Furthermore, it will pave the way for developing newer therapeutic agents to deal with biofilms more efficiently.},
}

@article {pmid38615826,
year = {2024},
author = {Pereira, ACC and Aguiar, APS and Barbosa, VL and Régia, JR and Miyazima, EM and Araujo, LMP and Dantas, LO and Mayer, MPA and Andrade, FB and Karygianni, L and Pinheiro, ET},
title = {Enhancing Antibiotic Efficacy in Regenerative Endodontics by Improving Biofilm Susceptibility.},
journal = {Journal of endodontics},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.joen.2024.04.004},
pmid = {38615826},
issn = {1878-3554},
abstract = {INTRODUCTION: Various strategies have been researched to enhance the susceptibility of biofilms, given their tolerance to antibiotics. This study evaluated the effect of the antimicrobial peptide nisin in association with antibiotics used in regenerative endodontics, exploring different treatment times and biofilm growth conditions.

METHODS: A mixture of ten bacterial species was cultivated on dentin specimens anaerobically for 21 days. Biofilms were treated with 1 mL of high-purity nisin Z (nisin ZP, 200 μg/mL) and a triple antibiotic mixture (TAP: ciprofloxacin + metronidazole + minocycline, 5mg/ mL), alone or in combination. The effectiveness of antimicrobial agents was assessed after one and seven days. During the 7-day period, biofilms were treated under two conditions: a single dose in a nutrient-depleted setting (i.e., no replenishment of growth medium) and multiple doses in a nutrient-rich environment (i.e., renewal of medium and antimicrobial agents every 48 h). After treatments, biofilm cells were dispersed, and total colony-forming units were counted.

RESULTS: After 1d-treatment, nisin ZP + TAP resulted in 2-log cell reduction compared to TAP alone (P < .05). After 7 d-treatment with a single dose, nisin ZP + TAP and TAP reduced bacteria to non-culturable levels (P < .05), whereas repeated antimicrobial doses did not eliminate bacteria in a nutrient-rich environment. No bacterial reduction was observed with nisin ZP alone in any treatment time.

CONCLUSIONS: The additional use of nisin improved the TAP activity only after a short exposure time. Longer exposure to TAP or nisin + TAP in a nutrient-deprived environment effectively eliminated biofilms.},
}

@article {pmid38614413,
year = {2024},
author = {Ali, A and Riaz, S},
title = {Emerging threats of high biofilm formation and antibiotic resistance in clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates from Pakistan.},
journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases},
volume = {},
number = {},
pages = {105592},
doi = {10.1016/j.meegid.2024.105592},
pmid = {38614413},
issn = {1567-7257},
abstract = {OBJECTIVES: This multicenter study, conducted from a One Health perspective, aimed to comprehensively examine the prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) infections and their biofilm-forming capabilities in Pakistan. Phylogenetic analysis of the study isolates was also performed.

METHODS: A total of 150 MRSA isolates were screened from various clinical samples using Cefoxitin antibiotic discs. Genotypic confirmation was conducted through mecA, S. aureus-specific nuc, and 16S rRNA genes. Biofilm formation was assessed using Congo red agar (CRA) and slime layer quantification methods. The intercellular adhesion (ica) operon genes, specifically icaA and icaD, were detected. Phylogenetic analysis utilized the 16S rRNA sequences. Statistical associations between various parameters were determined using chi-square analysis.

RESULTS: The presence of the mecA gene was observed in 131 out of 150 isolates (87.3%). CRA identified 28% and 40% of isolates as strong and moderate biofilm producers, respectively, while 9.3% were classified as non-biofilm producers. The slime layer assay exhibited higher sensitivity, classifying only 4.7% of isolates as non-biofilm producers. Biofilm-forming genes icaA and icaD were detected in 85.3% and 86.7% of the isolates, respectively. Antibiotic resistance was more prevalent among biofilm-forming isolates, particularly against ciprofloxacin, levofloxacin, erythromycin, trimethoprim-sulfamethoxazole, and fosfomycin. Ceftaroline demonstrated efficacy irrespective of biofilm-forming abilities. Conversely, non-biofilm producers exhibited complete susceptibility to clarithromycin and tigecycline.

CONCLUSIONS: Clinical MRSA strains exhibit a substantial potential for biofilm formation, contributing to a resistant phenotype. Routine antibiotic testing in clinical settings that overlook the biofilm aspect may lead to the failure of empiric antibiotic therapy.},
}

@article {pmid38614333,
year = {2024},
author = {Buakaew, T and Ratanatamskul, C},
title = {Unveiling the influence of microaeration and sludge recirculation on enhancement of pharmaceutical removal and microbial community change of the novel anaerobic baffled biofilm - membrane bioreactor in treating building wastewater.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {172420},
doi = {10.1016/j.scitotenv.2024.172420},
pmid = {38614333},
issn = {1879-1026},
abstract = {This research aims to conduct a comparative investigation of the role played by microaeration and sludge recirculation in the novel anaerobic baffled biofilm-membrane bioreactor (AnBB-MBR) for enhancing pharmaceutical removal from building wastewater. Three AnBB-MBRs - R1: AnBB-MBR, R2: AnBB-MBR with microaeration and R3: AnBB-MBR with microaeration and sludge recirculation - were operated simultaneously to remove Ciprofloxacin (CIP), Caffeine (CAF), Sulfamethoxazole (SMX) and Diclofenac (DCF) from real building wastewater at the hydraulic retention time (HRT) of 30 h for 115 days. From the removal profiles of the targeted pharmaceuticals in the AnBB-MBRs, it was found that the fixed-film compartment (C1) could significantly reduce the targeted pharmaceuticals. The remaining pharmaceuticals were further removed with the microaeration compartment. R2 exhibited the utmost removal efficiency for CIP (78.0 %) and DCF (40.8 %), while SMX was removed most successfully by R3 (microaeration with sludge recirculation) at 91.3 %, followed by microaeration in R2 (88.5 %). For CAF, it was easily removed by all AnBB-MBR systems (>90 %). The removal mechanisms indicate that the microaeration in R2 facilitated the adsorption of CIP onto microaerobic biomass, while the enhanced biodegradation of CAF, SMX and DCF was confirmed by batch biotransformation kinetics and the adsorption isotherms of the targeted pharmaceuticals. The microbial groups involved in biodegradation of the targeted compounds under microaeration were identified as nitrogen removal microbials (Nitrosomonas, Nitrospira, Thiobacillus, and Denitratisoma) and methanotrophs (Methylosarcina, Methylocaldum, and Methylocystis). Overall, explication of the integration of AnBB-MBR with microaeration (R2) confirmed it as a prospective technology for pharmaceutical removal from building wastewater due to its energy-efficient approach characterized by minimal aeration supply.},
}

@article {pmid38613837,
year = {2024},
author = {Quispe Haro, JJ and Chen, F and Los, R and Shi, S and Sun, W and Chen, Y and Idema, T and Wegner, SV},
title = {Optogenetic Control of Bacterial Cell-Cell Adhesion Dynamics: Unraveling the Influence on Biofilm Architecture and Functionality.},
journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)},
volume = {},
number = {},
pages = {e2310079},
doi = {10.1002/advs.202310079},
pmid = {38613837},
issn = {2198-3844},
support = {DFG WE 5745/2-2//Deutsche Forschungsgemeinschaft/ ; 22208157//National Natural Science Foundation of China/ ; },
abstract = {The transition of bacteria from an individualistic to a biofilm lifestyle profoundly alters their biology. During biofilm development, the bacterial cell-cell adhesions are a major determinant of initial microcolonies, which serve as kernels for the subsequent microscopic and mesoscopic structure of the biofilm, and determine the resulting functionality. In this study, the significance of bacterial cell-cell adhesion dynamics on bacterial aggregation and biofilm maturation is elucidated. Using photoswitchable adhesins between bacteria, modifying the dynamics of bacterial cell-cell adhesions with periodic dark-light cycles is systematic. Dynamic cell-cell adhesions with liquid-like behavior improve bacterial aggregation and produce more compact microcolonies than static adhesions with solid-like behavior in both experiments and individual-based simulations. Consequently, dynamic cell-cell adhesions give rise to earlier quorum sensing activation, better intermixing of different bacterial populations, improved biofilm maturation, changes in the growth of cocultures, and higher yields in fermentation. The here presented approach of tuning bacterial cell-cell adhesion dynamics opens the door for regulating the structure and function of biofilms and cocultures with potential biotechnological applications.},
}

@article {pmid38613443,
year = {2024},
author = {Hajimohammadi, S and Momtaz, H and Tajbakhsh, E},
title = {Fabrication and antimicrobial properties of novel meropenem-honey encapsulated chitosan nanoparticles against multiresistant and biofilm-forming Staphylococcus aureus as a new antimicrobial agent.},
journal = {Veterinary medicine and science},
volume = {10},
number = {3},
pages = {e1440},
doi = {10.1002/vms3.1440},
pmid = {38613443},
issn = {2053-1095},
support = {//Islamic Azad University, Shahrekord Branch/ ; },
abstract = {BACKGROUND: Honey exhibits a broad spectrum of antibacterial activity against Gram-positive and Gram-negative bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) ones. Chitosan (Cs) is a mucoadhesive polymer that also has antibacterial properties. Special attention has been paid to the design of polymeric nanoparticles (NPs) as new nano drug delivery systems to overcome bacterial resistance and its problems.

OBJECTIVES: The aim of the present study is to synthesize Cs-meropenem NPs with/without honey as an antibiofilm and antibacterial agent to inhibit Staphylococcus aureus.

METHODS: This study synthesized meropenem and honey-loaded Cs nanogels and subsequently characterized them by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), and DLS-zeta potential. Using the broth microdilution and crystal violet assays, the antibacterial and antibiofilm activity of meropenem and honey-loaded Cs nanogel, free meropenem, free honey, and free Cs NPs were investigated in vitro against MRSA strains. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) was also used to test the cytotoxicity of several Cs-NPs compound against the HEK-293 regular cell line.

RESULTS: The average size of meropenem and honey-Cs-NPs was reported to be 119.885 nm, and encapsulation efficiency was 88.33 ± 0.97 with stability up to 60 days at 4°C. The NPs showed enhanced antibiofilm efficacy against S. aureus at sub-minimum inhibitory concentrations. Additionally, the cytotoxicity of meropenem and honey-encapsulated Cs against the HEK-293 normal cell line was insignificant.

CONCLUSIONS: Our findings suggested that meropenem and honey-Cs-NPs might be potential antibacterial and antibiofilm materials.},
}

@article {pmid38612793,
year = {2024},
author = {Donati, L and Casagrande Pierantoni, D and Conti, A and Calzoni, E and Corte, L and Santi, C and Rosati, O and Cardinali, G and Emiliani, C},
title = {Water Extracts from Industrial Hemp Waste Inhibit the Adhesion and Development of Candida Biofilm and Showed Antioxidant Activity on HT-29 Colon Cancer Cells.},
journal = {International journal of molecular sciences},
volume = {25},
number = {7},
pages = {},
doi = {10.3390/ijms25073979},
pmid = {38612793},
issn = {1422-0067},
support = {J91B21003350006//Italian Ministry of University and Research (MIUR)/ ; },
abstract = {The evolution of regulatory perspectives regarding the health and nutritional properties of industrial hemp-based products (Cannabis sativa L.) has pushed research to focus on the development of new methods for both the extraction and formulation of the bioactive compounds present in hemp extracts. While the psychoactive and medicinal properties of hemp-derived cannabinoid extracts are well known, much less has been investigated on the functional and antimicrobial properties of hemp extracts. Within the hemp value chain, various agricultural wastes and by-products are generated. These materials can be valorised through eco-innovations, ultimately promoting sustainable economic development. In this study, we explored the use of waste from industrial light cannabis production for the extraction of bioactive compounds without the addition of chemicals. The five extracts obtained were tested for their antimicrobial activity on both planktonic and sessile cells of pathogenic strains of the Candida albicans, Candida parapsilosis, and Candida tropicalis species and for their antioxidant activity on HT-29 colon cancer cells under oxidative stress. Our results demonstrated that these extracts display interesting properties both as antioxidants and in hindering the development of fungal biofilm, paving the way for further investigations into the sustainable valorisation of hemp waste for different biomedical applications.},
}

@article {pmid38612411,
year = {2024},
author = {Chen, Y and Gao, Y and Li, Y and Yin, J},
title = {Anti-Biofilm Activity of Assamsaponin A, Theasaponin E1, and Theasaponin E2 against Candida albicans.},
journal = {International journal of molecular sciences},
volume = {25},
number = {7},
pages = {},
doi = {10.3390/ijms25073599},
pmid = {38612411},
issn = {1422-0067},
support = {CARS-19//China Agriculture Research System of MOF and MARA/ ; CAAS-ASTIP-TRI//the Innovation Project for Chinese Academy of Agricultural Sciences/ ; },
abstract = {Biofilm formation plays a crucial role in the pathogenesis of Candida albicans and is significantly associated with resistance to antifungal agents. Tea seed saponins, a class of non-ionic triterpenes, have been proven to have fungicidal effects on planktonic C. albicans. However, their anti-biofilm activity and mechanism of action against C. albicans remain unclear. In this study, the effects of three Camellia sinensis seed saponin monomers, namely, theasaponin E1 (TE1), theasaponin E2 (TE2), and assamsaponin A (ASA), on the metabolism, biofilm development, and expression of the virulence genes of C. albicans were evaluated. The results of the XTT reduction assay and crystal violet (CV) staining assay demonstrated that tea seed saponin monomers concentration-dependently suppressed the adhesion and biofilm formation of C. albicans and were able to eradicate mature biofilms. The compounds were in the following order in terms of their inhibitory effects: ASA > TE1 > TE2. The mechanisms were associated with reductions in multiple crucial virulence factors, including cell surface hydrophobicity (CSH), adhesion ability, hyphal morphology conversion, and phospholipase activity. It was further demonstrated through qRT-PCR analysis that the anti-biofilm activity of ASA and TE1 against C. albicans was attributed to the inhibition of RAS1 activation, which consequently suppressed the cAMP-PKA and MAPK signaling pathways. Conversely, TE2 appeared to regulate the morphological turnover and hyphal growth of C. albicans via a pathway that was independent of RAS1. These findings suggest that tea seed saponin monomers are promising innovative agents against C. albicans.},
}