Virulence gene detection and molecular typing of Vibrio parahaemolyticus in a food poisoning

Objective To study the virulence gene and molecular typing of pathogenic bacteria in a food poisoning caused by multi- serotype Vibrio parahaemolyticus. Methods Pathogens were separated and identified from suspicious samples in the food poisoning according to the microbiological examination methods of food hygiene GB/T4789- 2008. The detected Vibrio parahaemolyticus were conducted serological experiments,while real- time fluorescence- based quantitative PCR was applied to detect the virulence genes,pulsed field gel electrophoresis(PFGE) was used for molecular typing. Results A total of 12 strains of VP were detected,including 8 strains from patients' excrements and 4 strains from remaining food. In 12 strains of VP, tdh was positive in 9 strains,and one of those strains was from remaining food,while the rest were separated from patients' excrements. trh virulence genes were all negative in the 12 VP strains. Twelve VP strains were divided into 6 PEGE patterns by PEGE typing,and clustering analysis similarity percentage was from 66. 8% to 100%. Conclusion This food poisoning was caused by multi- serotype VP strains,and the jellyfishes polluted by O3: K6 type VP were the crucial cause. PFGE typing was applicable to the homology investigation of food poisoning caused by the multi- serotypes Vibrio parahaemolyticus.