title: Mutations in the extracellular protein secretion pathway genes (eps) interfere with rugose polysaccharide production in and motility of Vibrio cholerae.
abstract: Vibrio cholerae is the causal organism of the diarrheal disease cholera. The rugose variant of V. cholerae is associated with the secretion of an exopolysaccharide. The rugose polysaccharide has been shown to confer increased resistance to a variety of agents, such as chlorine, bioacids, and oxidative and osmotic stresses. It also promotes biofilm formation, thereby increasing the survival of the bacteria in the aquatic environments. Here we show that the extracellular protein secretion system (gene designated eps) is involved directly or indirectly in the production of rugose polysaccharide. A TnphoA insertion in epsD gene of the eps operon abolished the production of rugose polysaccharide, reduced the secretion of cholera toxin and hemolysin, and resulted in a nonmotile phenotype. We have constructed defined mutations of the epsD and epsE genes that affected these phenotypes and complemented these defects by plasmid clones of the respective wild-type genes. These results suggest a major role for the eps system in pathogenesis and environmental survival of V. cholerae.
authors.affiliation: Division of Hospital Epidemiology, Department of Medicine, University of Maryland at Baltimore, Maryland 21201, USA.
authors.forename: A
authors.initials: A
authors.lastname: Ali
authors.forename: J A
authors.initials: JA
authors.lastname: Johnson
authors.forename: A A
authors.initials: AA
authors.lastname: Franco
authors.forename: D J
authors.initials: DJ
authors.lastname: Metzger
authors.forename: T D
authors.initials: TD
authors.lastname: Connell
authors.forename: J G
authors.initials: JG
authors.lastname: Morris
authors.forename: S
authors.initials: S
authors.lastname: Sozhamannan
mesh_terms: D000469:Alkaline Phosphatase; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D002772:Cholera Toxin / Q000096:biosynthesis; D003001:Cloning, Molecular; D003360:Cosmids; D018844:Cyclin-Dependent Kinases / Q000235:genetics; D005407:Flagella / Q000502:physiology; D005816:Genetic Complementation Test; D006460:Hemolysin Proteins / Q000096:biosynthesis; D008565:Membrane Proteins; D009068:Movement; D016296:Mutagenesis; D009154:Mutation; D009876:Operon; D010641:Phenotype; D011134:Polysaccharides / Q000096:biosynthesis*; D014734:Vibrio cholerae / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; C406586:EpsD protein, Vibrio cholerae; C079398:EpsE protein, Vibrio cholerae; D006460:Hemolysin Proteins; D008565:Membrane Proteins; D011134:Polysaccharides; D002772:Cholera Toxin; D018844:Cyclin-Dependent Kinases; D000469:Alkaline Phosphatase