First description of French V. tubiashii strains pathogenic to mollusk: I. Characterization of isolates and detection during mortality events
|Author(s)||Travers Marie-Agnes1, Mersni Achour Rachida1, 2, 3, Haffner Philippe1, Tourbiez Delphine1, Cassone Anne-Laure1, Morga Benjamin1, Doghri Ibtissem2, Garcia Celine1, Renault Tristan1, Fruitier-Arnaudin Ingrid2, 3, Saulnier Denis1|
|Affiliation(s)||1 : IFREMER, LGPMM, SG2M, F-17390 La Tremblade, France.
2 : Univ La Rochelle, CNRS, LIENSs, Equipe Approches Mol,UMR 7266, F-17042 La Rochelle, France.
3 : Univ La Rochelle, Fédération de Recherche en Environnement et Développement Durable, FR CNRS 3097, F-17042 La Rochelle, France.
|Source||Journal Of Invertebrate Pathology (0022-2011) (Academic Press Inc Elsevier Science), 2014-11 , Vol. 123 , P. 38-48|
|WOS© Times Cited||26|
|Keyword(s)||Crassostrea gigas, Pathogenicity, Extracellular products, Polyphasic approach, Real time PCR|
|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.|