biofilms
Research Article | Therapeutics and PreventionCathelicidin Peptides Restrict Bacterial Growth via Membrane Perturbation and Induction of Reactive Oxygen SpeciesAntimicrobial peptides (AMPs) are an important part of the mammalian innate immune system in the battle against microbial infection. How AMPs function to control bacteria is not clear, as nearly all activity studies use nonphysiological levels of AMPs. We monitored peptide action in live bacterial cells over short time frames with single-cell resolution and found that the primary effect of cathelicidin peptides is to increase the...
Research Article | Molecular Biology and PhysiologyMolecular Basis and Ecological Relevance of Caulobacter Cell Filamentation in Freshwater HabitatsMany bacteria drastically change their cell size and morphology in response to changing environmental conditions. Here, we demonstrate that the freshwater bacterium Caulobacter crescentus and related species transform into filamentous cells in response to conditions that commonly occur in their natural habitat as a result of algal blooms during the warm summer months...
Research Article | Molecular Biology and PhysiologyAggregation of Nontuberculous Mycobacteria Is Regulated by Carbon-Nitrogen BalanceFree-living bacteria can assemble into multicellular structures called biofilms. Biofilms help bacteria tolerate multiple stresses, including antibiotics and the host immune system. Nontuberculous mycobacteria are a group of emerging opportunistic pathogens that utilize biofilms to adhere to household plumbing and showerheads and to avoid phagocytosis by host immune cells. Typically, bacteria regulate biofilm formation by controlling...
Editor's Pick Research Article | Ecological and Evolutionary SciencePseudomonas aeruginosa Interstrain Dynamics and Selection of Hyperbiofilm Mutants during a Chronic InfectionBacteria adapt to infections by evolving variants that are more fit and persistent. These recalcitrant variants are typically observed in chronic infections. However, it is unclear when and why these variants evolve. To address these questions, we used a porcine chronic wound model to study the evolutionary dynamics of Pseudomonas aeruginosa in a mixed-strain...
Research Article | Molecular Biology and PhysiologyIdentification of Extracellular DNA-Binding Proteins in the Biofilm MatrixMany bacteria are capable of forming biofilms encased in a matrix of self-produced extracellular polymeric substances (EPS) that protects them from chemotherapies and the host defenses. As a result of these inherent resistance mechanisms, bacterial biofilms are extremely difficult to eradicate and are associated with chronic wounds, orthopedic and surgical wound infections, and invasive infections, such as infective endocarditis and...
Research Article | Molecular Biology and PhysiologyMetabolic Remodeling during Biofilm Development of Bacillus subtilisBacterial biofilms are ubiquitous in natural environments and play an important role in many clinical, industrial, and ecological settings. Although much is known about the transcriptional regulatory networks that control biofilm formation in model bacteria such as Bacillus subtilis, very little is known about the role of metabolism in this complex developmental...
Editor's Pick Research Article | Therapeutics and PreventionEffects of a Novel Probiotic Combination on Pathogenic Bacterial-Fungal Polymicrobial BiofilmsThe effects of diversity of the gut microbiome on inflammation have centered mainly on bacterial flora. Recent research has implicated fungal species and their interactions with other organisms in the inflammatory process. New ways to restore microbial balance in the gut are being explored. Our goal was to identify beneficial probiotic strains that would antagonize these fungal and bacterial pathogens that are elevated in the inflamed...
Research Article | Molecular Biology and PhysiologyRespiratory Heterogeneity Shapes Biofilm Formation and Host Colonization in Uropathogenic Escherichia coliBiofilms are multicellular bacterial communities encased in a self-secreted extracellular matrix comprised of polysaccharides, proteinaceous fibers, and DNA. Organization of these components lends spatial organization in the biofilm community. Here we demonstrate that oxygen gradients in uropathogenic Escherichia coli (UPEC) biofilms lead to spatially distinct...
Research Article | Molecular Biology and PhysiologyCross Talk between Chemosensory Pathways That Modulate Chemotaxis and Biofilm FormationIn many bacteria, two or more homologous chemosensory pathways control several cellular functions, such as motility and gene regulation, in response to changes in the cell’s microenvironment. Cross talk between signal transduction systems is poorly understood; while generally it is considered to be undesired, in some instances it might be beneficial for coregulation of complex behaviors. We demonstrate that several receptors from the...
Research Article | Ecological and Evolutionary ScienceCompetition in Biofilms between Cystic Fibrosis Isolates of Pseudomonas aeruginosa Is Shaped by R-PyocinsA major clinical problem caused by Pseudomonas aeruginosa, is chronic biofilm infection of the lungs in individuals with cystic fibrosis (CF). Epidemic P. aeruginosa strains dominate and displace others during CF infection, but these intraspecies interactions remain poorly understood. Here we...