Subspecies typing of Vibrio parahaemolyticus in aquatic products with pulsed-field gel electrophoresis

Objective To assess subspecies typing of Vibrio parahaemolyticus strains from aquatic products with pulsed-field gel electrophoresis(PEGE).Methods A total of 80 selected isolates obtained from aquatic products were characterized with PFGE method.Genomic DNA w as digested with restriction endonucleases NotI and SfiI.Results The isolates were grouped into 68 PFGE patterns by NotI and SfiI.Moreover,there were 70 PFGE patterns after compared with the results of the two restriction enzymes.The discrimination power of NotI was 78.8% and that of SfiI was 76.3%.Fourteen strains were from Canada four strain groups according to the Dice coefficient of 100%,thereinto,the Dice coefficient of four strains was 91.8% and the Dice coefficient of ten strains was 93.3%.Three strains form Norway and two strains from New Zealand belonged to 2 groups,with the Dice coefficient of 100%.There were no other same strains detected.Conclusion The results indicate that PFGE with both NotI and SfiI could be used in discriminant analysis for Vibrio parahaemolyticus,but NotI is more effective.The clustering analysis showes a clear disagreement among the strains and their sources.Furthermore,the strains with virulence genes are included in the same or contiguous clusters.