Abstract
A total of 481 samples, including 417 shrimp and molluscan shellfish samples from retail shops and farms and 64 water samples from shrimp and molluscan shellfish farms in the Mekong Delta located the southern part of Vietnam, were examined for the presence of Vibrio parahaemolyticus (Vp(AHPND)) caused acute haepatopancreatic necrosic disease (AHPND) in shrimp. Vp(AHPND) strains were isolated in two of 298 (0.7%) molluscan shellfish samples from retail shops, seven of 71 (9.9%) shrimp samples from shrimp ponds, and two of 42 (4.8%) water samples from shrimp ponds. Vp(AHPND) strains were classified into two types of O antigen, including O1 and O3, in which O1 was the predominant. Vp(AHPND) strains isolated showed high resistance rates to colistin (100%), ampicillin (93.8%), and streptomycin (87.5%). These results indicate that Vp(AHPND) is widely prevalent in environment in the Mekong Delta, Vietnam.