title: Clinical and environmental genotypes of Vibrio vulnificus display distinct, quorum-sensing-mediated, chitin detachment dynamics.
abstract: The ability for bacteria to attach to and detach from various substrata is important for colonization, survival and transitioning to new environments. An opportunistic human pathogen, Vibrio vulnificus, can cause potentially fatal septicemia after ingestion of undercooked seafood. Based on genetic polymorphisms, strains of this species are subtyped into clinical (C) and environmental (E) genotypes. Vibrio vulnificus readily associates with chitin, thus we investigated chitin detachment dynamics in these disparate genotypes. We found that C-genotypes detach significantly more than E-genotypes after 24 hours in aerobic as well as anaerobic conditions. Furthermore, expression of genes involved in type IV pilin production was significantly downregulated in C-genotypes compared to E-genotypes, suggesting an importance in detachment. Interestingly, gbpA, a gene that has been shown to be important in host colonization in V. cholerae, was upregulated in the C-genotypes during detachment. Additionally, we found that C-genotypes detached to a greater extent, and produced more quorum-sensing (QS) autoinducer-2 molecules relative to E-genotypes, which suggests a role for QS in detachment. These findings suggest that for V. vulnificus, QS-mediated detachment may be a potential mechanism for transitioning into a human host for C-genotypes, while facilitating E-genotype maintenance in the estuarine environment.
authors.affiliation: Biological Sciences, UNCC, 9201 University City Blvd, Charlotte, NC 28223, USA.
authors.forename: Britney L
authors.initials: BL
authors.lastname: Phippen
authors.affiliation: Department of Biological Sciences, The University of North Carolina at Charlotte, Charlotte, NC 28223, USA jdoliver@uncc.edu.
authors.forename: James D
authors.initials: JD
authors.lastname: Oliver
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001422:Bacterial Adhesion; D002686:Chitin / Q000378:metabolism*; D036781:Fimbriae Proteins / Q000096:biosynthesis / Q000235:genetics; D020869:Gene Expression Profiling; D014644:Genetic Variation; D005838:Genotype; D006714:Homoserine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D007783:Lactones / Q000378:metabolism; D053038:Quorum Sensing; D014735:Vibrio Infections / Q000382:microbiology; D041261:Vibrio vulnificus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D014871:Water Microbiology
chemical_list: D007783:Lactones; C091088:N-octanoylhomoserine lactone; D002686:Chitin; D036781:Fimbriae Proteins; D006714:Homoserine
keywords: Vibrio vulnificus; anaerobiosis; biofilm; chitin detachment; quorum sensing; type IV pili