Published in Biochimica et Biophysica Acta
Bacterial biofilms are communities of bacterial cells surrounded by a self-secreted extracellular matrix. Biofilm formation by Vibrio cholerae, the human pathogen responsible for cholera, contributes to its environmental survival and infectivity. Important genetic and molecular requirements have been identified for V. cholerae biofilm formation, ye...
Published in Molecular BioSystems
Bacterial biofilms are assemblages of bacterial cells and extracellular matrix that result in the creation of surface-associated macrocolony formation. Most bacteria are capable of forming biofilms under suitable conditions. Biofilm formation by pathogenic bacteria on medical implant devices has been linked to implant rejection in up to 10% of case...
Published in Journal of Bacteriology
Rhodospirillum centenum resembles typical nonsulfur photosynthetic bacteria in a number of respects, including its ability to grow either anaerobically as a phototroph or aerobically as a heterotroph. We demonstrate, however, that R. centenum is unusual in its ability to synthesize a functional photosynthetic apparatus regardless of the presence of...
Published in Applied and Environmental Microbiology
Published in Current Opinion in Microbiology
Cyclic dimeric guanosine monophosphate (c-di-GMP) is a common, bacterial second messenger that regulates diverse cellular processes in bacteria. Opposing activities of diguanylate cyclases (DGCs) and phosphodiesterases (PDEs) control c-di-GMP homeostasis in the cell. Many microbes have a large number of genes encoding DGCs and PDEs that are predict...
Published in Proceedings of the National Academy of Sciences
Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is the principal cause for seasonal occurrence of cholera epidemics. This causality has been explained by postulating that V. cholerae forms biofilms in association with animate and inanimate surfaces. Alternatively, it has been proposed that bacterial patho...
Published in Journal of The Royal Society Interface
Monotrichous bacteria on surfaces exhibit complex spinning movements. Such spinning motility is often a part of the surface detachment launch sequence of these cells. To understand the impact of spinning motility on bacterial surface interactions, we develop a hydrodynamic model of a surface-bound bacterium, which reproduces behaviours that we obse...
Published in Microbiology
Biofilm formation enhances the survival and persistence of the facultative human pathogen Vibrio cholerae in natural ecosystems and its transmission during seasonal cholera outbreaks. A major component of the V. cholerae biofilm matrix is the Vibrio polysaccharide (VPS), which is essential for development of three-dimensional biofilm structures. Th...
Published in Journal of Bacteriology
A genetic system has been developed for studying bacterial photosynthesis in the recently described nonsulfur purple photosynthetic bacterium Rhodospirillum centenum. Nonphotosynthetic mutants of R. centenum were obtained by enrichment for spontaneous mutations, by ethyl methanesulfonate mutagenesis coupled to penicillin selection on solid medium, ...
Published in Journal of Bacteriology
Vibrio cholerae, the causative agent of the disease cholera, can generate rugose variants that have an increased capacity to form biofilms. Rugosity and biofilm formation are critical for the environmental survival and transmission of the pathogen, and these processes are controlled by cyclic diguanylate (c-di-GMP) signaling systems. c-di-GMP is pr...
Published in Pacific Symposium on Biocomputing. Pacific Symposium on Biocomputing
Published in Biophysical Journal
Biofilm formation increases both the survival and infectivity of Vibrio cholerae, the causative agent of cholera. V. cholerae is capable of forming biofilms on solid surfaces and at the air-liquid interface, termed pellicles. Known components of the extracellular matrix include the matrix proteins Bap1, RbmA, and RbmC, an exopolysaccharide termed V...
Published in Infection and Immunity
Published in Journal of Bacteriology
Vibrio cholerae switches between free-living motile and surface-attached sessile lifestyles. Cyclic diguanylate (c-di-GMP) is a signaling molecule controlling such lifestyle changes. C-di-GMP is synthesized by diguanylate cyclases (DGCs) that contain a GGDEF domain and is degraded by phosphodiesterases (PDEs) that contain an EAL or HD-GYP domain. W...
Published in Journal of Bacteriology
The rugose colonial variant of Vibrio cholerae O1 El Tor produces an exopolysaccharide (EPS(ETr)) that enables the organism to form a biofilm and to resist oxidative stress and the bactericidal action of chlorine. Transposon mutagenesis of the rugose variant led to the identification of vpsR, which codes for a homologue of the NtrC subclass of resp...
Published in Journal of Bacteriology
Vibrio cholerae undergoes phenotypic variation that generates two morphologically different variants, termed smooth and rugose. The transcriptional profiles of the two variants differ greatly, and many of the differentially regulated genes are controlled by a complex regulatory circuitry that includes the transcriptional regulators VpsR, VpsT, and ...
Published in Environmental Microbiology
Vibrio cholerae inhabits aquatic environments and colonizes the human digestive tract to cause the disease cholera. In these environments, V. cholerae copes with fluctuations in salinity and osmolarity by producing and transporting small, organic, highly soluble molecules called compatible solutes, which counteract extracellular osmotic pressure. C...
Published in PLANT PHYSIOLOGY
We have characterized sulfate transport in the unicellular green alga Chlamydomonas reinhardtii during growth under sulfur-sufficient and sulfur-deficient conditions. Both the Vmax and the substrate concentration at which sulfate transport is half of the maximum velocity of the sulfate transport (K1/2) for uptake were altered in starved cells: the ...
Published in Journal of Bacteriology
Vibrio cholerae switches between smooth and rugose colonial variants. The rugose variant produces more vibrio polysaccharides (VPS(El Tor)) and forms well-developed biofilms. Both phenotypes depend on expression of vps biosynthesis genes. We identified a positive transcriptional regulator of vps gene expression, VpsT, which is homologous to respons...
Published in ChemBioChem
Bacterial biofilms pose a significant challenge in clinical environments due to their inherent lack of susceptibility to antibiotic treatment. It is widely recognized that most pathogenic bacterial strains in the clinical setting persist in the biofilm state, and are the root cause of many recrudescent infections. The discovery and development of c...
