title: Comparative genomics of clinical and environmental Vibrio mimicus.
abstract: Whether Vibrio mimicus is a variant of Vibrio cholerae or a separate species has been the subject of taxonomic controversy. A genomic analysis was undertaken to resolve the issue. The genomes of V. mimicus MB451, a clinical isolate, and VM223, an environmental isolate, comprise ca. 4,347,971 and 4,313,453 bp and encode 3,802 and 3,290 ORFs, respectively. As in other vibrios, chromosome I (C-I) predominantly contains genes necessary for growth and viability, whereas chromosome II (C-II) bears genes for adaptation to environmental change. C-I harbors many virulence genes, including some not previously reported in V. mimicus, such as mannose-sensitive hemagglutinin (MSHA), and enterotoxigenic hemolysin (HlyA); C-II encodes a variant of Vibrio pathogenicity island 2 (VPI-2), and Vibrio seventh pandemic island II (VSP-II) cluster of genes. Extensive genomic rearrangement in C-II indicates it is a hot spot for evolution and genesis of speciation for the genus Vibrio. The number of virulence regions discovered in this study (VSP-II, MSHA, HlyA, type IV pilin, PilE, and integron integrase, IntI4) with no notable difference in potential virulence genes between clinical and environmental strains suggests these genes also may play a role in the environment and that pathogenic strains may arise in the environment. Significant genome synteny with prototypic pre-seventh pandemic strains of V. cholerae was observed, and the results of phylogenetic analysis support the hypothesis that, in the course of evolution, V. mimicus and V. cholerae diverged from a common ancestor with a prototypic sixth pandemic genomic backbone.
authors.affiliation: Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA.
authors.forename: Nur A
authors.initials: NA
authors.lastname: Hasan
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Grim
authors.forename: Bradd J
authors.initials: BJ
authors.lastname: Haley
authors.forename: Jongsik
authors.initials: J
authors.lastname: Chun
authors.forename: Munirul
authors.initials: M
authors.lastname: Alam
authors.forename: Elisa
authors.initials: E
authors.lastname: Taviani
authors.forename: Mozammel
authors.initials: M
authors.lastname: Hoq
authors.forename: A Christine
authors.initials: AC
authors.lastname: Munk
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Saunders
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Brettin
authors.forename: David C
authors.initials: DC
authors.lastname: Bruce
authors.forename: Jean F
authors.initials: JF
authors.lastname: Challacombe
authors.forename: J Chris
authors.initials: JC
authors.lastname: Detter
authors.forename: Cliff S
authors.initials: CS
authors.lastname: Han
authors.forename: Gary
authors.initials: G
authors.lastname: Xie
authors.forename: G Balakrish
authors.initials: GB
authors.lastname: Nair
authors.forename: Anwar
authors.initials: A
authors.lastname: Huq
authors.forename: Rita R
authors.initials: RR
authors.lastname: Colwell
mesh_terms: D002876:Chromosomes, Bacterial; D005798:Genes, Bacterial; D049810:Genetic Speciation; D016680:Genome, Bacterial; D023281:Genomics / Q000379:methods*; D026801:Synteny; D014734:Vibrio cholerae / Q000235:genetics; D044164:Vibrio mimicus / Q000235:genetics*