Etiological study on a case of food poisoning caused by multiple serotypes of Vibrio Parahaemolyticus

Objective To investigate virulence genes and molecular typing for pathogens from a food poisoning case caused by multiple serotypes of Vibrio parahaemolyticus.Methods Foodborne pathogen from those suspicious foodborne poisoning samples were isolated and identified.Vibrio parahaemolyticus isolated was tested by serological experiments.The strain’s virulence genes tdh(thermostable direct hemolysin),trh(tdh related hemolysin),and tlh(thermolabile emolysin) were analyzed by real-time PCR,and molecular typing was performed on the isolated strains using pulsed-field gel electrophoresis(PFGE).Results In this study,25 strains of Vibrio parahaemolyticus were obtained from 24 patients and one left-over food.The distribution of serotype included 4 strains of O4:K8,19 strains of O3:K6,1 strain of O4:KUT,and 1 strain of O3:KUT.The virulence genes for the 25 isolated strains of Vibrio parahaemolyticus were all identified as tdh+tlh+trh-;PFGE analysis indicated that different serotypes were divided into different clusters,while the difference of 1 to 2 strips existed between the PFGE strips for the same serotype strains,and correlation was found among strains.Conclusions This is a food poisoning case caused by multiple serotypes of Vibrio parahaemolyticus.