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The Analyst Dec 2023The formation of photosynthetic microbial biofilms comprising multispecies biomolecules, such as extracellular polymeric substances (EPSs), and microbial cells play...
The formation of photosynthetic microbial biofilms comprising multispecies biomolecules, such as extracellular polymeric substances (EPSs), and microbial cells play pivotal roles in maintaining or stimulating their biological functions. Although there are numerous studies on photosynthetic microbial biofilms, the spatial distribution of EPS components that are vital for microbial biofilm formation, such as exopolysaccharides and proteins, is not well understood. Visualization of photosynthetic microbial biofilms requires label-free methods, because labelling EPSs results in structural changes or aggregation. Raman spectroscopy is useful for label-free visualization of biofilm constituents based on chemical contrast. However, interference resulting from the bright autofluorescence of photosynthetic molecules and the low detection efficiency of Raman scattering make visualization a challenge. Herein, we visualized photosynthetic microbial biofilms in a label-free manner using a super-resolution optical infrared absorption imaging technique, called mid-infrared photothermal (MIP) microscopy. By leveraging the advantages of MIP microscopy, such as its sub-micrometer spatial resolution, autofluorescence-free features, and high detection sensitivity, the distribution of cyanobacteria and their extracellular polysaccharides in the biofilm matrix were successfully visualized. This showed that cyanobacterial cells were aligned along acidic/sulfated polysaccharides in the extracellular environment. Furthermore, spectroscopic analyses elucidated that during formation of biofilms, sulfated polysaccharides initially form linear structures followed by entrapment of cyanobacterial cells. The present study provides the foundation for further studies on the formation, structure, and biological functions of microbial biofilms.
Topics: Biofilms; Polysaccharides; Cyanobacteria; Microscopy; Optical Imaging
PubMed: 37947037
DOI: 10.1039/d3an01453c -
Biomaterials Science Aug 2020Pathogenic microbial biofilms that readily form on implantable medical devices or human tissues have posed a great threat to worldwide healthcare. Hopes are focused on... (Review)
Review
Pathogenic microbial biofilms that readily form on implantable medical devices or human tissues have posed a great threat to worldwide healthcare. Hopes are focused on preventive strategies towards biofilms, leaving a thought-provoking question: how to tackle the problem of established biofilms? In this review, we briefly summarize the functionalized biomaterials to combat biofilms and highlight current approaches to eradicate pre-existing biofilms. We believe that all of these strategies, alone or in combination, could represent a blueprint for fighting biofilm-associated infections in the postantibiotic era.
Topics: Biocompatible Materials; Biofilms; Humans; Prostheses and Implants
PubMed: 32500875
DOI: 10.1039/d0bm00526f -
Photodiagnosis and Photodynamic Therapy Sep 2023Polymethylmethacrylate (PMMA)-based removable orthodontic appliances are susceptible to microbial colonization due to the surface porosity, and accumulating the biofilms...
BACKGROUND
Polymethylmethacrylate (PMMA)-based removable orthodontic appliances are susceptible to microbial colonization due to the surface porosity, and accumulating the biofilms causes denture stomatitis. the present study evaluated the anti-biofilm and antiinflammatory effects of antimicrobial photo-sonodynamic therapy (aPSDT) against multispecies microbial biofilms (Candida albicans, Staphylococcus aureus, Streptococcus sobrinus, and Actinomyces naeslundii) formed on acrylic resin modified with nanoresveratrol (NR).
MATERIALS AND METHODS
Following the determination of the minimum biofilm inhibitory concentration (MBIC) of NR, in vitro anti-biofilm activity of NR was evaluated. The antibiofilm efficacy against multispecies microbial biofilm including C. albicans, S. aureus, S. sobrinus, and A. naeslundii, were assessed by biofilm inhibition test and the results were measured. To reveal the anti-inflammatory effects of aPSDT on human gingival fibroblast (HGF) cells, the gene expression levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were evaluated via quantitative real-time polymerase chain reaction (qRT-PCR).
RESULTS
According to the results, the MBIC dose of NR against multispecies microbial biofilm was considered 512 µg/mL. The highest biofilm reduction activity was observed in MBIC treated with aPSDT and 2 × MBIC exposed to light emitting diode (LED) and ultrasound waves (UW). The expression level of TNF-α and IL-6 genes were significantly increased when HGF cells were exposed to multispecies microbial biofilms (P<0.05), while after treatment with aPSDT, the expression levels of genes were significantly downregulated in all groups (P<0.05).
CONCLUSION
Overall, NR-mediated aPSDT reduced the growth of the multispecies microbial biofilm and downregulated the expression of TNF-α and IL-6 genes. Therefore, modified PMMA with NR can be serving as a promising new orthodontic acrylic resin against multispecies microbial biofilms and the effect of this new material is amplified when exposed to LED and UW.
Topics: Humans; Photochemotherapy; Staphylococcus aureus; Acrylic Resins; Tumor Necrosis Factor-alpha; Polymethyl Methacrylate; Interleukin-6; Photosensitizing Agents; Anti-Infective Agents; Candida albicans; Biofilms; Anti-Inflammatory Agents
PubMed: 37356699
DOI: 10.1016/j.pdpdt.2023.103669 -
Frontiers in Bioscience (Landmark... Mar 2024Biofilms, which consist of microorganisms enclosed in an extracellular polymeric material (EPS), hold immense importance in the fields of environmental research,... (Review)
Review
Biofilms, which consist of microorganisms enclosed in an extracellular polymeric material (EPS), hold immense importance in the fields of environmental research, industry, and medicine. They play a significant role in ecosystem dynamics and stability, but they also pose issues such as biofouling, corrosion, and pollution. Biofilms in medical environments are linked to persistent infections and elevated healthcare expenses. The EPS matrix plays a crucial role in maintaining the structural integrity and antibiotic resistance of these structures. The research primarily investigates the role of the EPS matrix in facilitating horizontal gene transfer among biofilm communities, with a particular emphasis on EPS and its impact on this process. The process is recognized as a pivotal mechanism in the emergence of antibiotic resistance, underscoring the crucial function of EPS in the dynamics of biofilms. The analysis also highlights the significant financial constraints caused by biofilms in several industries. Biofilm-associated infections in the healthcare sector result in escalated treatment expenses and extended hospitalization periods. In an industrial context, biofilms have a role in increasing maintenance expenses and product contamination, emphasizing the need for efficient management solutions. This review presents the most recent progress in biofilm research, emphasizing the utilization of sophisticated imaging tools and molecular methodologies. In addition to conventional imaging techniques, the research explores the utilization of sophisticated molecular tools, such as DNA and RNA sequencing, in conjunction with proteomics. These approaches are essential for assessing the genetic and metabolic mechanisms that regulate biofilm development and antibiotic resistance. The review underscores the significance of employing an interdisciplinary methodology in the study of biofilms. By incorporating a range of approaches, such as sophisticated imaging and molecular analysis, a comprehensive understanding of biofilm dynamics may be achieved. This approach also opens up possibilities for developing novel solutions to address the negative impacts of biofilms on health, industry, and the environment.
Topics: Biofilms; Humans; Drug Resistance, Microbial; Anti-Bacterial Agents; Gene Transfer, Horizontal; Drug Resistance, Bacterial; Extracellular Polymeric Substance Matrix; Bacteria
PubMed: 38682189
DOI: 10.31083/j.fbl2904133 -
Microbial Cell Factories Mar 2023Exopolysaccharides (EPS) secreted by beneficial lactobacilli exert a plethora of positive activities, but little is known about their effects on biofilms of...
BACKGROUND
Exopolysaccharides (EPS) secreted by beneficial lactobacilli exert a plethora of positive activities, but little is known about their effects on biofilms of opportunistic vaginal pathogens and especially on biofilms of lactobacilli themselves. Here, the EPS produced by six vaginal lactobacilli, belonging to Lactobacillus crispatus (BC1, BC4, BC5) and Lactobacillus gasseri (BC9, BC12, BC14) species were isolated from cultural supernatants and lyophilized.
RESULTS
Lactobacillus EPS were chemically characterized in terms of monosaccharide composition by liquid chromatography (LC) analysis coupled to UV and mass spectrometry (MS) detection. Moreover, the ability of EPS (0.1, 0.5, 1 mg/mL) to stimulate the biofilm formation of lactobacilli and to inhibit the formation of pathogens' biofilms was evaluated by crystal violet (CV) staining and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Isolated EPS (yields 133-426 mg/L) were heteropolysaccharides mainly composed of D-mannose (40-52%) and D-glucose (11-30%). For the first time we demonstrated that Lactobacillus EPS were able to stimulate in a dose-dependent manner (p < 0.05) the formation of biofilms of ten strains belonging to L. crispatus, L. gasseri and Limosilactobacillus vaginalis species, in terms of cell viability (84-282% increase at 1 mg/mL) and especially biofilm biomass (40-195% increase at 1 mg/mL), quantified with MTT assay and CV staining, respectively. EPS released from L. crispatus and L. gasseri were found to better stimulate the biofilms of the same producer species rather than that of other species, including producing strains themselves and other strains. Conversely, the biofilm formation of bacterial (Escherichia coli, Staphylococcus spp., Enterococcus spp. and Streptococcus agalactiae) and fungal (Candida spp.) pathogens was inhibited. The anti-biofilm activity was dose-dependent and was more marked for L. gasseri-derived EPS (inhibition up to 86%, 70%, and 58% at 1 mg/mL, 0.5 mg/mL, and 0.1 mg/mL, respectively), whilst L. crispatus-derived EPS resulted overall less efficient (inhibition up to 58% at 1 mg/mL and 40% at 0.5 mg/mL) (p < 0.05).
CONCLUSIONS
Lactobacilli-derived EPS favour the biofilm formation of lactobacilli preventing, at the same time, that of opportunistic pathogens. These results support the possible employment of EPS as postbiotics in medicine as a therapeutic/preventive strategy to counteract vaginal infections.
Topics: Lactobacillus; Vagina; Biofilms; Lactobacillus gasseri; Candida; Gentian Violet
PubMed: 36890519
DOI: 10.1186/s12934-023-02053-x -
Molecular Oral Microbiology Dec 2022Important processes related to the interaction of the oral microbiome with the tooth surface happen directly at the interface. For example, the chemical microenvironment... (Review)
Review
Important processes related to the interaction of the oral microbiome with the tooth surface happen directly at the interface. For example, the chemical microenvironment that exists at the interface of microbial biofilms and the native tooth structure is directly involved in caries development. Consequentially, a critical understanding of this interface and its chemical microenvironment would provide novel avenues in caries prevention, including secondary caries that often occurs at the interface of the dental biofilm, tooth structure, and dental material. Electrochemical sensors are a unique quantitative tool and have the inherent advantages of miniaturization, stability, and selectivity. That makes the electrochemical sensors ideal tools for studying these critical biofilm microenvironments with high precision. This review highlights the development and applications of several novel electrochemical sensors such as pH, Ca , and hydrogen peroxide sensors as scanning electrochemical microscope probes in addition to flexible pH wire sensors for real-time bacterial biofilm-dental surface and dental materials interface studies.
Topics: Humans; Biocompatible Materials; Biofilms; Dental Caries; Tooth; Bacteria
PubMed: 36300593
DOI: 10.1111/omi.12396 -
World Journal of Microbiology &... Aug 2020In natural environments, microorganisms form microbial aggregates called biofilms able to adhere to a multitude of different surfaces. Yeasts make no exception to this... (Review)
Review
In natural environments, microorganisms form microbial aggregates called biofilms able to adhere to a multitude of different surfaces. Yeasts make no exception to this rule, being able to form biofilms in a plethora of environmental niches. In food realms, yeast biofilms may cause major problems due to their alterative activities. In addition, yeast biofilms are tenacious structures difficult to eradicate or treat with the current arsenal of antifungal agents. Thus, much effort is being made to develop novel approaches to prevent and disrupt yeast biofilms, for example through the use of natural antimicrobials or small molecules with both inhibiting and dispersing properties. The aim of this review is to provide a synopsis of the most recent literature on yeast biofilms regarding: (i) biofilm formation mechanisms; (ii) occurrence in food and in food-related environments; and (iii) inhibition and dispersal using natural compounds, in particular.
Topics: Antifungal Agents; Biofilms; Food; Food Microbiology; Saccharomyces cerevisiae; Yeasts
PubMed: 32776210
DOI: 10.1007/s11274-020-02911-5 -
Biotechnology Journal Oct 2020Certain microbial biofilm in the human-microbiota community can negatively impact the host microbiome. This gives rise to various methods to prevent the formation of... (Review)
Review
Certain microbial biofilm in the human-microbiota community can negatively impact the host microbiome. This gives rise to various methods to prevent the formation of biofilms or to facilitate biofilm dispersal from surfaces and tissues in the host. Despite all these efforts, these persistent microbial biofilms on surfaces and in the host tissue can result in health problems to the host and its microbiome. It is the adaptive behavior of microbes within the biofilm that confers on these tenacious microbes the resistance to harsh environments, antibiotic treatments, and the ability to evade the host immune system. In this review, the approaches to combat microbial biofilm in the last decade are discussed. The biochemical pathway regulating biofilm formation is first discussed, followed by the discussion of the three approaches to combat biofilm formation: physical, chemical, and biological approaches. The advances in these approaches have given rise to methods of effectively dispersing the microbial biofilm and preventing the adherence of these microbial communities altogether. As there are numerous approaches to target biofilm, in this review the attempt is to provide insights on how these approaches have been used to modulate the host-microbiome by looking at the individual strengths and weaknesses.
Topics: Anti-Bacterial Agents; Bacteria; Biofilms; Homeostasis; Humans; Microbiota
PubMed: 32510869
DOI: 10.1002/biot.201900320 -
Environmental Pollution (Barking, Essex... Dec 2022Titanium dioxide nanoparticles (TiO NPs) easily combine with other pollutants such as heavy metals because of their excellent physiochemical properties. However, how...
Titanium dioxide nanoparticles (TiO NPs) easily combine with other pollutants such as heavy metals because of their excellent physiochemical properties. However, how such an interaction may affect the binding behavior of metals onto biofilms remains largely unclear. This study, examined the effects of TiO NPs on Cd accumulation and toxicity for natural periphytic biofilms were examined. The adsorption kinetics showed that adding 0.1 and 1 mg/L TiO-NPs increased the Cd adsorption of biofilms at equilibrium by 23.5% and 35.8%, respectively. However, adding 10 mg/L TiO NPs increased the Cd adsorption of biofilms at equilibrium by only 1.9%. The adsorption isotherms indicate that the presence of TiO NPs considerably increased the Cd adsorption capacity of the biofilms; however, this effect became less prominent at high TiO NP concentrations. The optimum pH for Cd adsorption increased with increasing Cd and TiO NP contents. At low concentrations, the coexistence of Cd and TiO NPs may facilitate their respective accumulation by stimulating the secretion of extracellular polymeric substances and enhancing the microbial activity of the biofilm. The presence of TiO NPs increases the surface binding energy between Cd and functional groups such as carboxyl groups, enhancing the Cd accumulation on the biofilm.
Topics: Adsorption; Cadmium; Water Pollutants, Chemical; Nanoparticles; Metals, Heavy; Biofilms
PubMed: 36152717
DOI: 10.1016/j.envpol.2022.120239 -
Journal of Bacteriology Sep 2019Biofilms occur in a broad range of environments under heterogeneous physicochemical conditions, such as in bioremediation plants, on surfaces of biomedical implants, and... (Review)
Review
Biofilms occur in a broad range of environments under heterogeneous physicochemical conditions, such as in bioremediation plants, on surfaces of biomedical implants, and in the lungs of cystic fibrosis patients. In these scenarios, biofilms are subjected to shear forces, but the mechanical integrity of these aggregates often prevents their disruption or dispersal. Biofilms' physical robustness is the result of the multiple biopolymers secreted by constituent microbial cells which are also responsible for numerous biological functions. A better understanding of the role of these biopolymers and their response to dynamic forces is therefore crucial for understanding the interplay between biofilm structure and function. In this paper, we review experimental techniques in rheology, which help quantify the viscoelasticity of biofilms, and modeling approaches from soft matter physics that can assist our understanding of the rheological properties. We describe how these methods could be combined with synthetic biology approaches to control and investigate the effects of secreted polymers on the physical properties of biofilms. We argue that without an integrated approach of the three disciplines, the links between genetics, composition, and interaction of matrix biopolymers and the viscoelastic properties of biofilms will be much harder to uncover.
Topics: Bacterial Physiological Phenomena; Bacterial Proteins; Biofilms; Biomechanical Phenomena; Gene Expression Regulation, Bacterial
PubMed: 31182499
DOI: 10.1128/JB.00101-19