Investigating Brunei’s Seafood Markets for Vibrio parahaemolyticus using the Most Probable Number-Polymerase Chain Reaction

Abstract

Background: Vibrio parahaemolyticus (V. parahaemolyticus) is the commonest source of seafood poisoning and has a very high incidence in the countries of Asian. Aims and Objectives:This study aims to investigate the presence of V. parahaemolyticus in seafood from Brunei seafood market using the Most Probable Number-Polymerase Chain Reaction (MPN-PCR).Results: None of the twnety-three seafood samples that were purchased at random from unselectively chosen wet markets and hypermarkets in Brunei Darussalam yielded V. parahaemolyticus. Conclusion:This could be due to any or a combination of: the absence or low level of V. parahaemolytius from where the samples were harvested, inactivation of V. parahaemolyticus during the processing and preservation of the samples, possible sampling factors as well as good hygienic practices in Brunei's seafood market The mechanism by which V. parahaemolyticus infects humans has yet to be entirely determined. However, pathogenic V. parahaemolyticus is known to produce either thermostable direct haemolysin (TDH), TDHrelated haemolysin (TRH) or both.13, 14 TDH and TRH are encoded by tdh and trh genes, respectively. Thus, they are recognized as major virulent factors of V. parahaemolyticus and either or both of these virulent factors can cause illness. The toxR gene is well conserved among V. parahaemolyticus which are nonpathogenic in the absence of tdh or/and trh gene, and consequently used as target for its specific detection. 15According to the Food and Agriculture Organization report, 16 seafood constitutes the main source of animal protein for a significant percentage of world population. Therefore, as V. parahaemolyticus is known to cause gastroenteritis which could be fatal if complications occur, it is important to determine its degree of contamination of seafood to prevent food poisoning in consumers. In addition as a very high level of contamination with V. parahaemolyticus has been reported in bivalves and shrimp culture environment in Malaysia, 12 it is highly likely that seafood in Brunei is also contaminated with V. parahaemolyticus due to the proximity of the two countries and importation of seafood into Brunei.Thus, this study investigated the presence of V. parahaemolyticus in seafood from both wetmarkets and hypermarkets in Brunei Darussalam using MPN-PCR method so as to provide insight into the biosafety assessment of V. parahaemolyticus in the Sultanate.