Analysis on Vibrio parahaemolyticus in shellfish products from coastal district of Ningbo

Objective:To understand the pollution of the Vibrio parahaemolyticus in shellfish products to provide the evidence for prevention and treatment of disease which caused by Vibrio parahaemolyticus.Methods:Five kinds of Shellfish products(Blood clam,Small clam,Oyster,Razor clam and Short necked clam) to be tested.According to the standard technique GB/T 4789.7-2003,serotype were typed by standard serum,drug-resistances were tested by disk diffusion method and virulence genes tdh and trh were determinated by PCR.Results:21 of 42th were infected by Vibrio parahaemolyticus,and the positive rate was 21/42(50.0%),including seven serum groups: O:1 9.5%(2/21),O:2 19.0%(4/21),O:3 19.0%(4/21),O:4 28.6%(6/21),O:7 4.8%(1/21),O:10 4.8%(1/21),O:11 14.3%(3/21).Drug sensitive test to show that 21 strains of Vibrio parahaemolyticus sensitive to cotrimoxazole and chloramphenicol,penicillin,aminoglycosides,sulfonamides,quinolones,cephalosporins have varying degrees of drug resistance.Two of 21 strains of Vibrio parahaemolyticus' tdh virulence gene were positive and trh virulence genes were negative.Conclusion:The separation of Vibrio parahaemolyticus from the shellfish products has the diversity of serotyping and drug-resistant multiple characteristics.