Characterization of Vibrio parahaemolyticus isolated from farmed sea bass (Dicentrarchus labrax) during disease outbreaks

Vibrio parahaemolyticus was isolated from the internal organs of diseased sea bass (Dicentrarchus labrax) cultured in a marine cage farm and an inshore fish farm in the summer 2010. All strains isolated from diseased sea bass were tested for virulence by intraperitoneal injection. The isolates (n = 6) were pathogenic for sea bass. Only bacterial strains showing haemolytic activity were virulent. LD50 values ranged from 3.52 × 104 to 2.29 × 106 cfu fish−1. In this study, we report the characterization and the virulence of V. parahaemolyticus strains isolated from sea bass originating from two different fish farms (marine cage farm and inshore fish farm in Tunisia).