Topic
Biofilm matrix
About: Biofilm matrix is a research topic. Over the lifetime, 1589 publications have been published within this topic receiving 110140 citations.
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TL;DR: The combined results suggested that CabA is a structural protein of the extracellular matrix and multimerizes to a conformation functional in building robust biofilms, which may render V. vulnificus to survive in hostile environments and reach a concentrated infective dose.
Abstract: A transcriptome analysis identified Vibrio vulnificus cabABC genes which were preferentially expressed in biofilms. The cabABC genes were transcribed as a single operon. The cabA gene was induced by elevated 3′,5′-cyclic diguanylic acid (c-di-GMP) and encoded a calcium-binding protein CabA. Comparison of the biofilms produced by the cabA mutant and its parent strain JN111 in microtiter plates using crystal-violet staining demonstrated that CabA contributed to biofilm formation in a calcium-dependent manner under elevated c-di-GMP conditions. Genetic and biochemical analyses revealed that CabA was secreted to the cell exterior through functional CabB and CabC, distributed throughout the biofilm matrix, and produced as the biofilm matured. These results, together with the observation that CabA also contributes to the development of rugose colony morphology, indicated that CabA is a matrix-associated protein required for maturation, rather than adhesion involved in the initial attachment, of biofilms. Microscopic comparison of the structure of biofilms produced by JN111 and the cabA mutant demonstrated that CabA is an extracellular matrix component essential for the development of the mature biofilm structures in flow cells and on oyster shells. Exogenously providing purified CabA restored the biofilm- and rugose colony-forming abilities of the cabA mutant when calcium was available. Circular dichroism and size exclusion analyses revealed that calcium binding induces CabA conformational changes which may lead to multimerization. Extracellular complementation experiments revealed that CabA can assemble a functional matrix only when exopolysaccharides coexist. Consequently, the combined results suggested that CabA is a structural protein of the extracellular matrix and multimerizes to a conformation functional in building robust biofilms, which may render V. vulnificus to survive in hostile environments and reach a concentrated infective dose.
32 citations
TL;DR: It is suggested that phospholipase production might act in synergism with the biofilm formation by inducing or exacerbating skin lesions in dogs, toward revealing the pathogenicity of M. pachydermatis in animals.
32 citations
TL;DR: A dual-targeting approach that can enhance antibiofilm efficacy and precision by dismantling the EPS matrix and its protective microenvironment, amplifying the killing of pathogenic bacteria within is demonstrated.
Abstract: Biofilm formation is a key virulence factor responsible for a wide range of infectious diseases, including dental caries. Cariogenic biofilms are structured microbial communities embedded in an extracellular matrix that affords bacterial adhesion-cohesion and drug tolerance, making them difficult to treat using conventional antimicrobial monotherapy. Here, we investigated a multitargeted approach combining exopolysaccharide (EPS) matrix-degrading glucanohydrolases with a clinically used essential oils-based antimicrobial to potentiate antibiofilm efficacy. Our data showed that dextranase and mutanase can synergistically break down the EPS glucan matrix in preformed cariogenic biofilms, markedly enhancing bacterial killing by the antimicrobial agent (3-log increase versus antimicrobial alone). Further analyses revealed that an EPS-degrading/antimicrobial (EDA) approach disassembles the matrix scaffold, exposing the bacterial cells for efficient killing while concurrently causing cellular dispersion and "physical collapse" of the bacterial clusters. Unexpectedly, we found that the EDA approach can also selectively target the EPS-producing cariogenic bacteria Streptococcus mutans with higher killing specificity (versus other species) within mixed biofilms, disrupting their accumulation and promoting dominance of commensal bacteria. Together, these results demonstrate a dual-targeting approach that can enhance antibiofilm efficacy and precision by dismantling the EPS matrix and its protective microenvironment, amplifying the killing of pathogenic bacteria within.
32 citations
TL;DR: This work develops the first biofilm simulation framework that captures key mechanistic features of biofilm growth and phage infection and finds that the equilibrium state of interaction between biofilms and phages is governed largely by nutrient availability to biofilm, infection likelihood per host encounter, and the ability of phages to diffuse through biofilm populations.
Abstract: Many bacteria are adapted for attaching to surfaces and for building complex communities, termed biofilms. The biofilm mode of life is predominant in bacterial ecology. So, too, is exposure of bacteria to ubiquitous viral pathogens, termed bacteriophages. Although biofilm-phage encounters are likely to be very common in nature, little is known about how phages might interact with biofilm-dwelling bacteria. It is also unclear how the ecological dynamics of phages and their hosts depend on the biological and physical properties of the biofilm environment. To make headway in this area, here we develop the first biofilm simulation framework that captures key features of biofilm growth and phage infection. Using these simulations, we find that the equilibrium state of interaction between biofilms and phages is governed largely by nutrient availability to biofilms, phage infection likelihood, and the ability of phages to diffuse through biofilm populations. Interactions between the biofilm matrix and phage particles are thus likely to be of fundamental importance, controlling the extent to which bacteria and phages can coexist in natural contexts. Our results open avenues to new questions of host-parasite coevolution in the spatially structured biofilm context.
31 citations
TL;DR: Interestingly, the two EPS polysaccharides protect cells in both liquid culture and in biofilms against ROS caused by matric stress, indicating that cellulose and alginate do not need to be produced as an integral part of the biofilm lifestyle to provide tolerance towards environmental stressors.
Abstract: In natural environments most bacteria live in biofilms embedded in complex matrices of extracellular polymeric substances (EPS). This lifestyle is known to increase protection against environmental stress. Pseudomonas putida mt-2 harbours genes for the production of at least four different EPS polysaccharides, including alginate and cellulose. Little is known about the functional properties of cellulose, while alginate attenuates the accumulation of reactive oxygen species (ROS) caused by matric stress. By using mutants that are deficient in either alginate or cellulose production we show that even cellulose attenuates the accumulation of matric stress-induced ROS for cells in biofilms. Further, both cellulose and alginate attenuate ROS generated through exposure to copper. Interestingly, the two EPS polysaccharides protect cells in both liquid culture and in biofilms against ROS caused by matric stress, indicating that cellulose and alginate do not need to be produced as an integral part of the biofilm lifestyle to provide tolerance towards environmental stressors.
31 citations