Prevalence of Potentially Pathogenic VibrioSpecies in the Seafood Marketed in Malaysia

Seafood samples obtained in seafood markets and supermarkets at 11 sites selected from four states in Malaysia were examined for the presence of nine potentially pathogenic species from the genus Vibriobetween July 1998 and June 1999. We examined 768 sample sets that included shrimp, squid, crab, cockles, and mussels. We extensively examined shrimp samples from Selangor State to determine seasonal variation of vibrio populations. Eight potentially pathogenic Vibriospecies were detected, with overall incidence in the samples at 4.6% for V. cholerae, 4.7% for V. parahaemolyticus, 6.0% for V. vulnificus, 11% for V. alginolyticus, 9.9% for V. metschnikovii, 1.3% for V. mimicus, 13% for V. damsela, 7.6% for V. fluvialis, and 52% for a combined population of all of the above. As many as eight Vibriospecies were detected in shrimp and only four in squid and peel mussels. The overall percent incidence of any of the eight vibrios was highest (82%) in cockles (Anadara granosa) among the seafoods examined and was highest (100%) in Kuching, Sarawak State, and lowest (25%) in Penang, Pulau Penang State, among the sampling sites. Of 97 strains of V. choleraeisolated, one strain belonged to the O1 serotype and 14 to the O139 serotype. The results indicate that the various seafood markets in Malaysia are contaminated with potentially pathogenic Vibriospecies regardless of the season and suggest that there is a need for adequate consumer protection measures.