A5021320199- Vibrio bacteria research studies
- Bacterial biofilms and quorum sensing
- Aquaculture disease management and microbiota
- Antibiotic Resistance in Bacteria
- Bacterial Genetics and Biotechnology
- Legionella and Acanthamoeba research
- Microbial Community Ecology and Physiology
- Escherichia coli research studies
- Antimicrobial Peptides and Activities
- Lipid Membrane Structure and Behavior
- Photosynthetic Processes and Mechanisms
- Salmonella and Campylobacter epidemiology
- Cell Image Analysis Techniques
- Bacteriophages and microbial interactions
- Metabolomics and Mass Spectrometry Studies
- Analytical Chemistry and Chromatography
- Nitrogen and Sulfur Effects on Brassica
- Machine Learning in Bioinformatics
- Algal biology and biofuel production
- Mass Spectrometry Techniques and Applications
- bioluminescence and chemiluminescence research
- Genomics and Phylogenetic Studies
- Gene expression and cancer classification
- Yersinia bacterium, plague, ectoparasites research
- Protist diversity and phylogeny
University of California, Santa Cruz
2016-2025
Johns Hopkins University
2011
Johns Hopkins Medicine
2011
Howard Hughes Medical Institute
2006
Tufts University
2006
Technical University of Denmark
2005
UNSW Sydney
2005
Stanford University
1998-2001
Carnegie Institution for Science
1994-1996
Carnegie Department of Plant Biology
1994-1996
The rugose colony variant of Vibrio cholerae O1, biotype El Tor, is shown to produce an exopolysaccharide, EPS ETr , that confers chlorine resistance and biofilm-forming capacity. production requires a chromosomal locus, vps contains sequences homologous carbohydrate biosynthesis genes other bacterial species. Mutations within this locus yield chlorine-sensitive, smooth variants are biofilm deficient. properties may enable the survival V. O1 environmental aquatic habitats between outbreaks...
Decoding a Second-Messenger's Message Biofilms are aggregates of bacteria on surface often associated with increased resistance to antibiotics and stress. In Vibrio cholerae , the bacterial species that causes cholera, biofilm formation is promoted by second-messenger cyclic diguanylate (c-di-GMP) involves transcription regulator, VpsT. Krasteva et al. (p. 866 ) show VpsT itself receptor for c-di-GMP binding small signaling molecule promotes dimerization, which required DNA recognition...
Biofilms Up Close Many bacterial infections involve biofilm formation. Cells within a are significantly more resistant to immune clearance and antibiotics compared unattached, planktonic cells. Berk et al. (p. 236 ) applied superresolution optical methods image living bacteria with nanometer-scale precision as they form biofilm. Vibrio cholerae biofilms were observed have three distinct levels of spatial organization: cells, clusters collections clusters. Each cell cluster was wrapped in...
Abstract Biofilms are microbial communities that represent a highly abundant form of life on Earth. Inside biofilms, phenotypic and genotypic variations occur in three-dimensional space time; microscopy quantitative image analysis therefore crucial for elucidating their functions. Here, we present BiofilmQ—a comprehensive cytometry software tool the automated high-throughput quantification, visualization numerous biofilm-internal whole-biofilm properties time.
Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is principal cause for seasonal occurrence cholera epidemics. This causality has been explained by postulating that V. forms biofilms association with animate and inanimate surfaces. Alternatively, it proposed pathogens are an integral part natural microbial food web thus their survival constrained protozoan predation. Here, we report both explanations interrelated. Our data show protective agent...
Reversible phase variation between the rugose and smooth colony variants is predicted to be important for survival of Vibrio cholerae in natural aquatic habitats. Microarray expression profiling studies same strain led identification 124 differentially regulated genes. Further experiments showed how these genes are by VpsR HapR transcription factors, which, respectively, positively negatively regulate production VPS(El Tor), a rugose-associated extracellular polysaccharide. The study mutants...
ABSTRACT Vibrio cholerae is known to persist in aquatic environments under nutrient-limiting conditions. To analyze the possible involvement of alternative sigma factor encoded by rpoS , which shown be important for survival during nutrient deprivation several other bacterial species, a V. homolog was cloned functional complementation an Escherichia coli mutant using wild-type genomic library. Sequence analysis complementing clone revealed 1.008-bp open reading frame predicted encode...
ABSTRACT The rugose colonial variant of Vibrio cholerae O1 El Tor produces an exopolysaccharide (EPS ETr ) that enables the organism to form a biofilm and resist oxidative stress bactericidal action chlorine. Transposon mutagenesis led identification vpsR , which codes for homologue NtrC subclass response regulators. Targeted disruption in colony genetic background yielded nonreverting smooth-colony morphotype produced no detectable EPS did not architecturally mature biofilm. Analysis two...
Biofilm formation enhances the survival and persistence of facultative human pathogen Vibrio cholerae in natural ecosystems its transmission during seasonal cholera outbreaks. A major component V. biofilm matrix is polysaccharide (VPS), which essential for development three-dimensional structures. The vps genes are clustered two regions, vps- I cluster ( vpsU , vpsA–K VC0916–27) II vpsL–Q VC0934–39), separated by an intergenic region containing rbm gene that encodes proteins. In-frame...
Summary Cyclic di‐guanylic acid (c‐diGMP) is a second messenger that modulates the cell surface properties of several microorganisms. Concentrations c‐diGMP in are controlled by opposing activities diguanylate cyclases and phosphodiesterases, which carried out proteins harbouring GGDEF EAL domains respectively. In this study, we report cellular levels higher Vibrio cholerae rugose variant compared with smooth variant. Modulation overexpressing or increased decreased colony rugosity Several...
Vibrio cholerae switches between smooth and rugose colonial variants. The variant produces more vibrio polysaccharides (VPS(El Tor)) forms well-developed biofilms. Both phenotypes depend on expression of vps biosynthesis genes. We identified a positive transcriptional regulator gene expression, VpsT, which is homologous to response regulators two-component regulatory systems. Disruption vpsT in the yields colonies, prevents formation mature biofilms, decreases expression. interaction VpsT...
Vibrio cholerae, the causative agent of cholera, is a facultative human pathogen with intestinal and aquatic life cycles. The capacity V. cholerae to recognize respond fluctuating parameters in its environment critical survival. In many microorganisms, second messenger, 3',5'-cyclic diguanylic acid (c-di-GMP), believed be important for integrating environmental stimuli that affect cell physiology. Sequence analysis genome has revealed an abundance genes encoding proteins either GGDEF...
Vibrio cholerae is a motile bacterium responsible for the disease cholera, and motility has been hypothesized to be inversely regulated with virulence. We examined transcription profiles of V. strains containing mutations in flagellar regulatory genes (rpoN, flrA, flrC, fliA) by utilizing whole-genome microarrays. Results revealed that organized into four-tiered hierarchy. Additionally, proven or putative roles virulence (e.g., ctx, tcp, hemolysin, type VI secretion genes) were upregulated...
Vibrio cholerae, the causative agent of cholera, can undergo phenotypic variation generating rugose and smooth variants. The variant forms corrugated colonies well-developed biofilms exhibits increased levels resistance to several environmental stresses. Many these phenotypes are mediated in part by expression vps genes, which organized into vps-I vps-II coding regions, separated an intergenic region. In this study, we generated in-frame deletions five genes located region, termed rbmB -F...
ABSTRACT Indole has been proposed to act as an extracellular signal molecule influencing biofilm formation in a range of bacteria. For this study, the role indole Vibrio cholerae was examined. It shown that activates genes involved vibrio polysaccharide (VPS) production, which is essential for V . formation. In addition activating these genes, it determined using microarrays influences expression many other including those motility, protozoan grazing resistance, iron utilization, and ion...
ABSTRACT Vibrio cholerae undergoes phenotypic variation that generates two morphologically different variants, termed smooth and rugose. The transcriptional profiles of the variants differ greatly, many differentially regulated genes are controlled by a complex regulatory circuitry includes regulators VpsR, VpsT, HapR. In this study, we identified VpsT regulon compared VpsR regulons to elucidate contribution each positive regulator rugose variant profile associated phenotypes. We have found...
Vibrio cholerae is a facultative human pathogen. The ability of V. to form biofilms crucial for its survival in aquatic habitats between epidemics and advantageous host-to-host transmission during epidemics. Formation mature requires the production extracellular matrix components, including polysaccharide (VPS) proteins. Biofilm formation positively controlled by transcriptional regulators VpsR VpsT negatively regulated quorum-sensing regulator HapR, as well cyclic AMP (cAMP)-cAMP receptor...