A food poisoning event caused by Vibrio parahaemolyticus of 2 serotypes

In August 2009,a food poisoning event occurred in Jianggan district in Hangzhou,Ten people in a tourist group with 32 members were affected,the attack rate was 31.2%.The anal swabs were collected from 10 patients and O4:K8 Vibrio parahaemolyticu was detected,meanwhile O3: K6 Vibrio parahaemolyticu was detected in 5 of 10 samples.The toxin gene tdh was detected in Vibrio parahaemolyticus strains in two serotypes.PFGE typing showed that strains of the same serotype were highly similar,but the strains of different serotypes in a same sample were different clones.