Characterisation and virulence properties of Vibrio isolates from diseased gilthead sea bream (Sparus aurata) cultured in Tunisia.

摘要

A bacteriological study of 7 outbreaks affecting cultured gilthead sea bream (Sparus aurata L.) along the Tunisian coast from 2002 to 2004 has been carried out. Bacteria isolated from infected fish were identified as Vibrio alginolyticus and Vibrio harveyi, and further characterized by conventional tests. Moreover, virulence of isolates (mean lethal dose, LD< sub>50), serum resistance as well as adherence and resistance to bactericidal effect of skin mucus were determined. Mean lethal doses (LD< sub>50) determined by intraperitoneal injection ranged from 2x105 to 106 cfu/g body weight. The strains showed a remarkable resistance in gilthead sea bream serum and they were able to adhere to skin mucus and use it as nutrient.