||Gay Melanie, Renault Tristan, Pons Anne-Marie, Le Roux Frédérique
||IFREMER, Lab Genet & Pathol, F-17390 La Tremblade, France.
Univ La Rochelle, Lab Biotechnol & Chim Bioorgan, CNRS, FRE 2766, F-17042 La Rochelle, France.
||Diseases of aquatic organisms (0177-5103) (Inter-Research), 2004-11 , Vol. 62 , N. 1-2 , P. 65-74
|WOS© Times Cited
||Histopathology, Molecular taxonomy, Agonism, Vibriosis
||For several years, strains phenotypically related to Vibrio splendidus have been associated with mortality outbreaks of molluscs. A former study on Crassostrea gigas demonstrated the genetic diversity of V splendidus strains associated with diseased animals. Another study suggested that different strains may act in an additive/synergistic way leading to higher C. gigas mortality rates. Here, a strain pair (31+32) was characterised at taxonomic and virulence levels. Using a polyphasic approach, these strains were confirmed to be V splendidus-related, without a clear discrimination between V. kanaloae and V. pomeroyi since hybridisation rates with both these strains were above 70%. Following experimental infection of C. gigas by injection in the adductor muscle or in the pallial cavity, the host alterations induced were described. After injection of strains 31 and/or 32, bacteria were localised at the periphery of the muscle and induced extensive lesions of the translucent part of the adductor muscle. Muscle alterations were of 3 kinds: (1) presence of isolated rounded muscular fibres containing non-homogenous granular material and surrounded by a translucent halo; (2) presence of non-homogenous granular material in the cytoplasm of entire muscle bands; (3) affection of wide muscle areas with extremely condensed muscle fibres. Infiltration associated with these lesions was notably absent in the vast majority of the individuals.