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Virulence Dec 2024Bacterial biofilms have attracted significant attention due to their involvement in persistent infections, food and water contamination, and infrastructure corrosion.... (Review)
Review
Bacterial biofilms have attracted significant attention due to their involvement in persistent infections, food and water contamination, and infrastructure corrosion. This review delves into the intricate interactions between bacterial biofilms and unicellular parasites, shedding light on their impact on biofilm formation, structure, and function. Unicellular parasites, including protozoa, influence bacterial biofilms through grazing activities, leading to adaptive changes in bacterial communities. Moreover, parasites like and can shape biofilm composition in a grazing independent manner, potentially influencing disease outcomes. Biofilms, acting as reservoirs, enable the survival of protozoan parasites against environmental stressors and antimicrobial agents. Furthermore, these biofilms may influence parasite virulence and stress responses, posing challenges in disease treatment. Interactions between unicellular parasites and fungal-containing biofilms is also discussed, hinting at complex microbial relationships in various ecosystems. Understanding these interactions offers insights into disease mechanisms and antibiotic resistance dissemination, paving the way for innovative therapeutic strategies and ecosystem-level implications.
Topics: Animals; Parasites; Ecosystem; Biofilms; Drug Resistance, Microbial; Anti-Infective Agents; Bacteria
PubMed: 38058008
DOI: 10.1080/21505594.2023.2289775 -
Biophysical Journal Jul 2023Microbial communities such as swarms or biofilms often form at the interfaces of solid substrates and open fluid flows. At the same time, in laboratory environments...
Microbial communities such as swarms or biofilms often form at the interfaces of solid substrates and open fluid flows. At the same time, in laboratory environments these communities are commonly studied using microfluidic devices with media flows and open boundaries. Extracellular signaling within these communities is therefore subject to different constraints than signaling within classic, closed-boundary systems such as developing embryos or tissues, yet is understudied by comparison. Here, we use mathematical modeling to show how advective-diffusive boundary flows and population geometry impact cell-cell signaling in monolayer microbial communities. We reveal conditions where the intercellular signaling lengthscale depends solely on the population geometry and not on diffusion or degradation, as commonly expected. We further demonstrate that diffusive coupling with the boundary flow can produce signal gradients within an isogenic population, even when there is no flow within the population. We use our theory to provide new insights into the signaling mechanisms of published experimental results, and we make several experimentally verifiable predictions. Our research highlights the importance of carefully evaluating boundary dynamics and environmental geometry when modeling microbial cell-cell signaling and informs the study of cell behaviors in both natural and synthetic systems.
Topics: Models, Theoretical; Biofilms; Microbiota; Signal Transduction; Cell Communication
PubMed: 37300250
DOI: 10.1016/j.bpj.2023.06.002 -
NPJ Biofilms and Microbiomes Sep 2023Bacterial biofilms, which consist of three-dimensional extracellular polymeric substance (EPS), not only function as signaling networks, provide nutritional support, and... (Review)
Review
Bacterial biofilms, which consist of three-dimensional extracellular polymeric substance (EPS), not only function as signaling networks, provide nutritional support, and facilitate surface adhesion, but also serve as a protective shield for the residing bacterial inhabitants against external stress, such as antibiotics, antimicrobials, and host immune responses. Biofilm-associated infections account for 65-80% of all human microbial infections that lead to serious mortality and morbidity. Tremendous effort has been spent to address the problem by developing biofilm-dispersing agents to discharge colonized microbial cells to a more vulnerable planktonic state. Here, we discuss the recent progress of enzymatic eradicating strategies against medical biofilms, with a focus on dispersal mechanisms. Particularly, we review three enzyme classes that have been extensively investigated, namely glycoside hydrolases, proteases, and deoxyribonucleases.
Topics: Humans; Extracellular Polymeric Substance Matrix; Biofilms; Anti-Bacterial Agents; Plankton; Signal Transduction
PubMed: 37679355
DOI: 10.1038/s41522-023-00427-y -
The Science of the Total Environment Jan 2024Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been detected in most aquatic environments worldwide and are referred to as "forever chemicals" because of... (Review)
Review
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been detected in most aquatic environments worldwide and are referred to as "forever chemicals" because of their extreme chemical and thermal stability. Biofilms, as basic aquatic bioresources, can colonize various substratum surfaces. Biofilms in the aquatic environment have to interact with the ubiquitous PFASs and have significant implications for both their behavior and destiny, which are still poorly understood. Here, we have a preliminary literature exploration of the interaction between PFASs and biofilms in the various aquatic environments and expect to provide some thoughts on further study. In this review, the biosorption properties of biofilms on PFASs and possible mechanisms are presented. The complex impact of PFASs on biofilm systems was further discussed in terms of the composition and electrical charges of extracellular polymeric substances, intracellular microbial communities, and overall contaminant purification functions. Correspondingly, the effects of biofilms on the redistribution of PFASs in the aqueous environment were analyzed. Finally, we propose that biofilm after adsorption of PFASs is a unique ecological niche that not only reflects the contamination level of PFASs in the aquatic environment but also offers a possible "microbial pool" for PFASs biodegradation. We outline existing knowledge gaps and potential future efforts for investigating how PFASs interact with biofilms in aquatic ecosystems.
Topics: Fluorocarbons; Water Pollutants, Chemical; Water; Biofilms; Microbiota
PubMed: 37778566
DOI: 10.1016/j.scitotenv.2023.167469 -
Nature Communications Jul 2023The role of microbial interactions and the underlying mechanisms that shape complex biofilm communities are poorly understood. Here we employ a microfluidic chip to...
The role of microbial interactions and the underlying mechanisms that shape complex biofilm communities are poorly understood. Here we employ a microfluidic chip to represent porous subsurface environments and show that cooperative microbial interactions between free-living and biofilm-forming bacteria trigger active spatial segregation to promote their respective dominance in segregated microhabitats. During initial colonization, free-living and biofilm-forming microbes are segregated from the mixed planktonic inoculum to occupy the ambient fluid and grain surface. Contrary to spatial exclusion through competition, the active spatial segregation is induced by cooperative interactions which improves the fitness of both biofilm and planktonic populations. We further show that free-living Arthrobacter induces the surface colonization by scavenging the biofilm inhibitor, D-amino acids and receives benefits from the public goods secreted by the biofilm-forming strains. Collectively, our results reveal how cooperative microbial interactions may contribute to microbial coexistence in segregated microhabitats and drive subsurface biofilm community succession.
Topics: Porosity; Microbial Interactions; Biofilms; Bacteria; Plankton
PubMed: 37454222
DOI: 10.1038/s41467-023-39991-4 -
Journal of Dental Research Aug 2023Oral cryotherapy is used in dentistry as a safe, simple, and low-cost treatment for a variety of oral lesions. It is well known for its ability to aid in the healing...
Oral cryotherapy is used in dentistry as a safe, simple, and low-cost treatment for a variety of oral lesions. It is well known for its ability to aid in the healing process. However, its effect on oral biofilms is unknown. As a result, the purpose of this study was to assess the effects of cryotherapy on in vitro oral biofilms. In vitro multispecies oral biofilms were grown on the surface of hydroxyapatite discs in symbiotic or dysbiotic states. CryoPen X+ was used to treat the biofilms, whereas untreated biofilms served as control. One set of biofilms was collected for study immediately after cryotherapy, whereas another group was reincubated for 24 h to permit biofilm recovery. Changes in biofilm structure were analyzed with a confocal laser scanning microscope (CLSM) and a scanning electron microscope (SEM), while biofilm ecology and community compositional changes were analyzed with viability DNA extraction and quantitative polymerase chain reaction (v-qPCR) analysis. One cryo-cycle immediately reduced biofilm load by 0.2 to 0.4 log Geq/mL, which increased with additional treatment cycles. Although the bacterial load of the treated biofilms recovered to the same level as the control biofilms within 24 h, the CLSM detected structural alterations. Compositional alterations were also detected by SEM, corroborating the v-qPCR findings that showed ≈≤10% incidence of pathogenic species compared to nontreated biofilms that encompassed ≈45% and 13% pathogenic species in dysbiotic and symbiotic biofilms, respectively. Spray cryotherapy showed promising results in a novel conceptual approach to the control of oral biofilms. Acting selectively by targeting oral pathobionts and retaining commensals, spray cryotherapy could modify the ecology of in vitro oral biofilms to become more symbiotic and prevent the evolution of dysbiosis without the use of antiseptics/antimicrobials.
Topics: Anti-Infective Agents; Bacterial Load; Biofilms; Cryotherapy
PubMed: 37278360
DOI: 10.1177/00220345231172688 -
Journal of Bacteriology Apr 2024Bacterial biofilms are intricate ecosystems of microbial communities that adhere to various surfaces and are enveloped by an extracellular matrix composed of polymeric... (Review)
Review
Bacterial biofilms are intricate ecosystems of microbial communities that adhere to various surfaces and are enveloped by an extracellular matrix composed of polymeric substances. Within the context of bacterial biofilms, extracellular DNA (eDNA) originates from cell lysis or is actively secreted, where it exerts a significant influence on the formation, stability, and resistance of biofilms to environmental stressors. The exploration of eDNA within bacterial biofilms holds paramount importance in research, with far-reaching implications for both human health and the environment. An enhanced understanding of the functions of eDNA in biofilm formation and antibiotic resistance could inspire the development of strategies to combat biofilm-related infections and improve the management of antibiotic resistance. This comprehensive review encapsulates the latest discoveries concerning eDNA, encompassing its origins, functions within bacterial biofilms, and significance in bacterial pathogenesis.
Topics: Humans; DNA, Bacterial; Ecosystem; Biofilms; Bacteria; Extracellular Matrix
PubMed: 38445859
DOI: 10.1128/jb.00006-24 -
Biosurfactants: Secondary Metabolites Involved in the Process of Bioremediation and Biofilm Removal.Applied Biochemistry and Biotechnology Sep 2023The search for environmentally friendly methods to remove persistent substances such as organic pollutants and sessile communities such as biofilms that severely affect... (Review)
Review
The search for environmentally friendly methods to remove persistent substances such as organic pollutants and sessile communities such as biofilms that severely affect the environment and human health resulted in biosurfactant discovery. Owing to their low level of toxicity and high biodegradability, biosurfactants are increasingly preferred to be used for removal of pollutants from nature. These amphipathic molecules can be synthesized inexpensively, employing cheap substrates such as agricultural and industrial wastes. Recent progress has been made in identifying various biosurfactants that can be used to remove organic pollutants and harmful microbial aggregates, as well as novel microbial strains that produce these surface-active molecules to survive in a hydrocarbon-rich environment. This review focuses on the identification and understanding the role of biosurfactants and the microorganisms involved in the removal of biofilms and remediation of xenobiotics and various types of hydrocarbons such as crude oil, aromatic hydrocarbons, n-alkanes, aliphatic hydrocarbons, asphaltenes, naphthenes, and other petroleum products. This property of biosurfactant is very important as biofilms are of great concern due to their impact on the environment, public health, and industries worldwide. This work also includes several advanced molecular methods that can be used to enhance the production of biosurfactants by the microorganisms studied.
Topics: Humans; Biodegradation, Environmental; Surface-Active Agents; Environmental Pollutants; Hydrocarbons; Petroleum; Biofilms
PubMed: 35579742
DOI: 10.1007/s12010-022-03951-3 -
Food Research International (Ottawa,... Oct 2023This review presents a survey of two extremely important technologies about CO with the effectiveness of controlling microorganisms - atmospheric pressure CO-based... (Review)
Review
This review presents a survey of two extremely important technologies about CO with the effectiveness of controlling microorganisms - atmospheric pressure CO-based modified atmosphere packaging (MAP) and high pressure CO non-thermal pasteurization (HPCD). CO-based MAP is effectively in delaying the lag and logarithmic phases of microorganisms by replacing the surrounding air, while HPCD achieved sterilization by subjecting food to either subcritical or supercritical CO for some time in a continuous, batch or semi-batch way. In addition to the advantages of healthy, eco-friendly, quality-preserving, effective characteristic, some challenges such as the high drip loss and packaging collapse associated with higher concentration of CO, the fuzzy mechanisms of oxidative stress, the unproven specific metabolic pathways and biomarkers, etc., in CO-based MAP, and the unavoidable extraction of bioactive compounds, the challenging application in solid foods with higher efficiency, the difficult balance between optimal sterilization and optimal food quality, etc., in HPCD still need more efforts to overcome. The action mechanism of CO on microorganisms, researches in recent years, problems and future perspectives are summarized. When dissolved in solution medium or cellular fluids, CO can form carbonic acid (HCO), and HCO can further dissociate into bicarbonate ions (HCO), carbonate (CO) and hydrogen cations (H) ionic species following series equilibria. The action mode of CO on microorganisms may be relevant to changes in intracellular pH, alteration of proteins, enzyme structure and function, alteration of cell membrane function and fluidity, and so on. Nevertheless, the effects of CO on microbial biofilms, energy metabolism, protein and gene expression also need to be explored more extensively and deeply to further understand the action mechanism of CO on microorganisms.
Topics: Carbon Dioxide; Atmospheric Pressure; Biofilms; Cell Membrane; Energy Metabolism
PubMed: 37689923
DOI: 10.1016/j.foodres.2023.113170 -
Applied Biochemistry and Biotechnology Sep 2023Biofilm is the conglomeration of microbial cells which is associated with a surface. In the recent times, the study of biofilm has gained popularity and vivid research... (Review)
Review
Biofilm is the conglomeration of microbial cells which is associated with a surface. In the recent times, the study of biofilm has gained popularity and vivid research is being done to know about the effects of biofilm and that it consists of many organisms which are symbiotic in nature, some of which are human pathogens. Here, in this study, we have discussed about biofilms, its formation, relevance of its presence in the biosphere, and the possible remediations to cope up with its negative effects. Since removal of biofilm is difficult, emphasis has been made to suggest ways to prevent biofilm formation and also to devise ways to utilize biofilm in an economically and environment-friendly method.
Topics: Humans; Quorum Sensing; Biofilms
PubMed: 35829902
DOI: 10.1007/s12010-022-04075-4