Vibrio detection in market seafood samples of Kuwait by biochemical (API 20E) strips and its evaluation against 16s rDNA-based molecular methods

Seafood Vibrio is one of the causes of food-borne infections in Kuwait. Surveillance of food borne diseases is one of the high priority tasks in the public health agenda worldwide. This study was conducted over a period of two years from 2008-2010. Three fish markets in Kuwait were selected for seafood sampling, at quarterly intervals, for six quarters and a total of 238 seafood samples were collected. The seafood collections included important food fishes and shellfishes such as; grouper, silver pomfret, bluefin bream and shrimp. Bacterial isolates from the skin swabs, the muscle extracts and kidney were analyzed for the identity using classical biochemical assays on API 20E and compared with the results obtained on the 16s rDNA amplification. The samples were plated on triptone citrate bile salt sucrose (TCBS) agar for a presumptive vibrio diagnostic. Prevalence of Vibrio in the seafood samples was found to be 77.99 ± 7.48% (presumptive Vibrio positivity or PVP). The PVP was highly and positively correlated with the surface Vibrio contamination (r = 0.63). A sample of 45 randomly-selected isolates analyzed using API 20E and the analytical probability index (API) so obtained showed that 43.75% of the samples had confirmatory Vibrio levels. The vibrio positive random samples selected after API 20E analyses were found to amplify the vibrio specific 625 bp 16s rDNA gene.