Prevalence of Vibrio parahaemolyticus O3:K6 in aquaculture water environment and raw seafood in the Mekong Delta

Abstract

Vibrio parahaemolyticus is one of the important foodborne pathogens in human. Most of the infected cases relate to raw or undercook seafood. Among the serotypes of pathogenic V. parahaemolyticus, O3:K6 is the most important serotype because it was predominant serotype isolated from the patients in the worldwide. In this study, the raw seafood and water samples in the Mekong Delta were examined for prevalence of V. parahaemolyticus associated with foodborne illness in human. 204 raw seafood samples were collected in the retail markets, 16 clam samples were collected from the clam farms, 39 shrimp samples were collected from the intensive shrimp culture ponds, 30 water samples were collected from Mekong river, 22 water samples were collected from the clam farms and 42 water samples were collected from the intensive shrimp culture ponds, they were used as materials for this study.
The studied results indicated that there were 10/172 (5.8%) mollusca samples positive with V. parahaemolyticus carrying tdh virulent gene; meanwhile, this pathogenic bacterium was not found in the shrimp samples and other seafood samples collected from the aquaculture farms and river water samples collected from the Mekong Delta. 10 V. parahaemolyticus isolates carrying tdh gene were analyzed and from that serotypes and pathogenic signs were identified. Of which, 4 strains belonged to serotype O3:K6 and all of 4 these strains were positive with the signs of causing the intestinal diseases in human. The other strains were negative to cause diseases. This studied result can be used for understanding microbiological risk of raw seafood in the Mekong Delta