title: First description of French V. tubiashii strains pathogenic to mollusk: I. Characterization of isolates and detection during mortality events.
abstract: Nine dominant bacterial isolates were obtained from different batches of Crassostrea gigas spat experiencing high mortality rates in a French experimental hatchery/nursery in 2007. Using phenotypic analysis combined with multilocus sequence analysis, the isolates were shown to be genetically close to the Vibrio tubiashii type strain. Based on (1) analyses of the recA gene sequences; (2) the results of DNA-DNA hybridization assays between 07/118 T2 (LMG 27884=CECT 8426), which is a representative strain, and the V. tubiashii type strain (69%); and (3) phenotypic traits, the bacteria were classified in a group close to American V. tubiashii strain. Its virulence (70% of mortalities) and the toxicity of the extracellular products of 07/118 T2 was demonstrated (41% of mortalities). Moreover, a QPCR diagnostic tool targeting the gyrB gene was developed to investigate the epidemiological significance of V. tubiashii in French oyster mortality outbreaks recorded by the national surveillance network. Of the 21 batches originating from hatcheries, only two were positive, whereas V. tubiashii DNA could not be detected in any of the batches of moribund animals collected in field/outdoor facilities. These results demonstrate the existence of a group of virulent V. tubiashii in France that episodically infect C. gigas.
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France. Electronic address: marie.agnes.travers@ifremer.fr.
authors.forename: Marie-Agnès
authors.initials: MA
authors.lastname: Travers
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France; UMR 7266 CNRS-ULR, LIENSs, Equipe Approches Moléculaires, Environnement-Santé, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle, France; Fédération de Recherche en Environnement et Développement Durable, FR CNRS 3097, Université de La Rochelle, France.
authors.forename: Rachida
authors.initials: R
authors.lastname: Mersni Achour
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Haffner
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Tourbiez
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Cassone
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Morga
authors.affiliation: UMR 7266 CNRS-ULR, LIENSs, Equipe Approches Moléculaires, Environnement-Santé, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle, France.
authors.forename: Ibtissem
authors.initials: I
authors.lastname: Doghri
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Garcia
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France.
authors.forename: Tristan
authors.initials: T
authors.lastname: Renault
authors.affiliation: UMR 7266 CNRS-ULR, LIENSs, Equipe Approches Moléculaires, Environnement-Santé, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle, France; Fédération de Recherche en Environnement et Développement Durable, FR CNRS 3097, Université de La Rochelle, France.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Fruitier-Arnaudin
authors.affiliation: Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Saulnier
mesh_terms: D000818:Animals; D049896:Crassostrea / Q000382:microbiology*; D004591:Electrophoresis, Polyacrylamide Gel; D013058:Mass Spectrometry; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014733:Vibrio / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity
keywords: Crassostrea gigas; Extracellular products; Pathogenicity; Polyphasic approach; Real time PCR