title: Vibrio metoecus sp. nov., a close relative of Vibrio cholerae isolated from coastal brackish ponds and clinical specimens.
abstract: A Gram-staining-negative, curved-rod-shaped bacterium with close resemblance to Vibrio cholerae, the aetiological agent of cholera, was isolated over the course of several years from coastal brackish water (17 strains) and from clinical cases (two strains) in the United States. 16S rRNA gene identity with V. cholerae exceeded 98 % yet an average nucleotide identity based on genome data of around 86 % and multi locus sequence analysis of six housekeeping genes (mdh, adk, gyrB, recA, pgi and rpoB) clearly delineated these isolates as a distinct genotypic cluster within the V. cholerae-V. mimicus clade. Most standard identification techniques do not differentiate this cluster of isolates from V. cholerae. Only amplification of the ompW gene using V. cholerae-specific primers and a negative Voges-Proskauer test showed a difference between the two clusters. Additionally, all isolated strains differed phenotypically from V. cholerae in their ability to utilize N-acetyl-d-galactosamine and d-glucuronic acid as sole carbon sources. Furthermore, they were generally unable to infect the slime mould Dictyostelium discoideum, a widespread ability in V. cholerae. Based on these clear phenotypic differences that are not necessarily apparent in standard tests as well as average nucleotide identity and phylogeny of protein-coding genes, we propose the existence of a novel species, Vibrio metoecus sp. nov. with the type strain OP3H(T) ( = LMG 27764(T) = CIP 110643(T)). Due to its close resemblance to V. cholerae and the increasing number of strains isolated over the past several years, we suggest that V. metoecus sp. nov. is a relatively common species of the genus Vibrio, isolates of which have been identified as atypical isolates of V. cholerae in the past. Its isolation from clinical samples also indicates that strains of this species, like V. cholerae, are opportunistic pathogens.
authors: Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
authors: Paul C
authors: PC
authors: Kirchberger
authors: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors: Maryann
authors: M
authors: Turnsek
authors: Nicholas School of the Environment, Duke University, Beaufort, NC, USA.
authors: Dana E
authors: DE
authors: Hunt
authors: University of Maryland Institute for Advanced Computer Studies and Maryland Pathogen Research Institute, College Park, MD, USA.
authors: Bradd J
authors: BJ
authors: Haley
authors: Department of Environmental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.|University of Maryland Institute for Advanced Computer Studies and Maryland Pathogen Research Institute, College Park, MD, USA.
authors: Rita R
authors: RR
authors: Colwell
authors: Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
authors: Martin F
authors: MF
authors: Polz
authors: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors: Cheryl L
authors: CL
authors: Tarr
authors: Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
authors: Yan
authors: Y
authors: Boucher
mesh_terms: D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D061005:Ponds / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014481:United States; D014733:Vibrio / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S