| Objective: The purpose of this study is to investigate the contamination status of Vibrio parahaemolyticus on the processe of breeding,salling and catering about aquatic products in Hubei,and to understand the antibiotic resistance and molecular typing characteristics of Vibrio parahaemolyticus isolates.At the same time,through researching and analysising the gene mapping and homologous gene sequences,correlation analysis of resistance gene and Vibrio parahaemolyticus isolates related to drug resistance,antibiotic resistance and its sources in the culture-Sales-table "throughout the food chain in the process of transmission mechanism,in order to take effectively on the measures to avoid the resistance genes through wide dissemination of the food chain diffusion,so as to curb the spread of bacterial resistance and to protect public health and safety.Research program:1.sampling point selectionsChoose 2 — 3 farms,3 sales locations,3 catering units and a comprehensive hospital as the representatives in each region of 2 developed areas about non adjacent freshwater aquaculture industry.2.sampling arrangement(a)To collect 3 samples of aquatic products,environmental water bodies(which are in direct contact with the corresponding aquatic products)and bottom sediments(water bodies in the corresponding aquatic products)in the farms.(b)To collect 2 samples of aquatic products and environmental water bodies(in direct contact with the corresponding aquatic products)in the place of salling and catering.(c)To collect fecal samples from diarrhea patients in sentinel hospitals.3.Identification of Vibrio parahaemolyticus IsolationBy 3% sodium chloride alkaline peptone water enrichment,CHROMagar Vibrio chromogenic plate isolation,through VITEK automatic bacteria identification system for biochemical identification of suspicious strains.4.Pulse field gel electrophoresisAccording to Vibrio cholerae pulsed field gel electrophoresis the standard methods recommended by CDC,with the endonuclease Not of pathogenic Vibrio strains were PFGE type,the electrophoresis patterns of molecular traceability analysis using national foodborne disease molecular traceability network.5.Analysis of drug resistance of pathogenic VibrioThe antimicrobial resistance of Vibrio parahaemolyticus was analyzed by broth dilution method.Antibiotics choose oxacillin,ciprofloxacin,cefoxitin,cefotaxime,clindamycin,chloramphenicol,gentamicin,erythromycin,vancomycin,nalidixic acid,tetracycline and trimethoprim Pyridine/sulfamethoxazole.The criteria for determining resistance to drugs refer to the requirements of resistance monitoring of Vibrio parahaemolyticus in the National Food Safety Risk Assessment Project.Result:1.Among the 645 samples collected,89 samples of Vibrio parahaemolyticus were detected,and the positive rate was 13.8%.14 strains of Vibrio parahaemolyticus cholerae positive strains were isolated from diarrhea patients in sentinel hospitals.In the detection of virulence genes found in the external environment is not found outside the TLH positive strains,seafood detected a TDH positive strains,hospital strains TDH are positive.2.In the different sources of Vibrio parahaemolyticus by pulsed field gel electrophoresis(Pulsed Field Gel Electrophoresis)PFGE type,PFGE profiles are quite different,the similar interval(60.6%-100%)mainly concentrated in the 4 gene cluster distribution,and there is a certain relationship.3.A large number of positive strains were found to be resistant to multiple drug-resistant strains.The positive rate of the positive strains collected in the hospital was higher than that in the outer environment.Conclusion:1.The detection rate of two virulence genes of TDH and TRH in aquatic products of external environment is much lower than that of bacteria isolated from hospital.2.Cluster analysis showed that the genetic relationship between seawater and freshwater products was mainly concentrated in the P2 gene cluster..3.Vibrio parahaemolyticus detected in aquatic products is mainly resistant to vancomycin and erythromycin. |
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