Isolation of Vibrio parahaemolyticus and Vibrio cholerae (Non-01 and 0139) from moribund shrimp (Penaeus monodon) and experimental challenge study against post larvae and juveniles

Abstract

Outbreak of Vibrio infection was reported from a shrimp farm near Chennai, south India. Both green and yel- low Vibrio were isoiated from disease outbreak of Penaeus monodon (Miine Edwards) cuiture farm and biochemically con- firmed as Vibrio parahaemoiyticus and Vibrio choierae. Randomly selected V. parahaemolyticus (VP1) and V. cholerae (VCI) were reconfirmed by partial 165 rRNA gene anaiysis. Both were tested against post larvae and juveniies of P. mon- odon by bath challenge test and intramuscular injection respectively. The study reveaied that VPl Is more virulent than VC1 isolated from same source against P. monodon post larvae and juveniles. Phylogenetic tree based on comparison of partial 165 rRNA gene analysis reveaied close relationship of VPI with other shrimp pathogens like Vibrio haweyi and Vibrio aiginoiyticus. There might be some close reiationship for disease development among ail these strains