Identification of Vibrio parahaemolyticus in Seafood by Multiplex PCR

Vibrio parahaemolyticus is a human pathogen frequently found in seafood. Once the seafood is contaminated by V. parahaemolyticus, it can become a vehicle for foodborne illness. The conventional culture methods for detection of V. parahaemolyticus are time-consuming and cannot differentiate pathogenic strains from nonpathogenic ones. In this study, a multiplex polymerase chain reaction (PCR) technique was investigated for detecting tdh, chiA, and toxR of V. parahaemolyticus. The sensitivity of the multiplex PCR was determined by testing 28 strains of V. parahaemolyticus, 15 non-V. parahaemolyticus strains, and fresh seafood spiked with cells of V. parahaemolyticus. All the strains were analyzed for production of thermostable direct hemolysin (TDH) and chitinase. This study showed that both the chiA and toxR are excellent markers for detecting V. parahaemolyticus strains, and a multiplex PCR targeting chiA and tdh genes can be applied to simultaneously detect environmental and pathogenic V. parahaemolyticus.