Detection and toxic gene analysis of Vbrio parahaemolyticus in seashells from coastal area of Dalian city

Objective To evaluate the contamination status of Vibrio parahaemolyticus(Vp)and 3 virulence genes in seashells from coastal area of Dalian city.Methods A total of 132 fresh seashells samples were collected from retail markets and oyster farms in Dalian municipality and detected for Vp with real-time PCR.The tdh,trh,and orf8 genes were also tested.Results The results showed that the 43 genes of Vp were detected and the detection rate was 32.6%(43/132).The tdh genes were detected in 2 out of 43 isolates of Vp and the detection rate was 4.7%.The trh genes were detected in 2 out of 43 isolates of Vp and the detection rate was 4.7%.The orf8 genes were detected in 1 out of 43 isolates of Vp,and the detection rate was 2.3%.The orf8 genes and the tdh genes were detected in 1 out of 43 isolates of Vp and the detection rate was 2.3%.The trh genes and tdh genes were detected in 16 out of 43 isolates of Vp,and the detection rate was 37.2%.The tl genes were detected in 23 out of 80 isolates of Vp in oyster samples and the detection rate was 28.8%,including 10 samples containing virulence genes.Conclusion Heavy Vp contamination exists in seashells from coastal area of Dalian.