Abstract:

Objective To study on homology of Vibrio parahaemolyticus（VP） isolated from a case of food poisoning by pulsed-field gel electrophoresis（PFGE）,and to provide a reference for the traceability of VP causing food poisoning. Methods A total of 7 cases and 5 cases of anal swabs from patients and kitcheners,5 cases from food retentions and 8 cases from environmental samples were collected and determined. Biochemical identification,serological typing,virulence gene detection and PFGE were performed. Results The serotype of VP isolated from anal swabs（4 isolates） and food（fishery product,2 isolates）was O3：K6,and there existed transmembrane transcriptional activation protein gene（tox R）-positive,thermostable direct haemolysin（tdh）-positive and thermostable-related haemolysin（trh）-negative. The serotype of VP isolated from food（vegetable,2 isolates） was O4：K2. There existed tox R-positive,tdh-negative and trh-negative. They had the same PFGE pattern,showing high homology. Conclusions The cause of this food poisoning is fishery product polluted by VP of O3：K6 serotype. PFGE has high resolution which enables itself to identify products and trace infection sources.

Key words: Vibrio parahaemolyticus, Food poisoning, Pulsed-field gel electrophoresis