Surveillance on Contamination,Viroluence and Drug Resistance of Vibrio parahaemolyticus in Summer and Autumn Seafood in Nanjing

Objective To investigate the contamination,viroluence and drug resistance of Vibrio parahaemolyticus among summer and autumn seafood in Nanjing Methods Seafood samples were collected from farm produce markets and restaurants.National standard detection methods(GB/T4789-2008) were adopted in the isolation of Vibrio parahaemolyticus by CHROMagar vibrio colored medium,and the isolated purple colonies were identified by PCR.Kanagawa test and drug sensitivity test were conducted for the isolated strains.Results Among 296 seafood samples,237 strains of Vibrio parahaemolyticus were isolated,with the detection rate of 80.1%.The detection rates of frozen and fresh-keeping marine fish,shellfish products,fresh fish and shrimps,fresh seaweed and jellyfishes were 96.4%,80.8%,6.7%,40.9% and 66.7% respectively.The detection results of species-specific tlh gene of Vibrio parahaemolyticus by PCR were in agreement with those determined by CHROMagar vibrio colored medium.Among 237 strains of V.parahaemolyticus,Kanagawa tests showed positive results in 69 strains.Drug sensitivity tests showed that V.parahaemolyticus exhibited various degrees of resistance to the common antibiotics,but it was highly sensitive to ceftriaxone,cefuroxime,vancomycin,minocycline,ofloxacin,midecamycin,cephalosporin V,amikacin,norfloxacin,ciprofloxacin and ceftazidime.Conclusions There exists serious contamination by V.parahaemolyticus in seafood produced in summer and autumn in Nanjing.29.1% of the isolated strains are virulent and some strains are resistant to 16 kinds of antibiotics at different degrees.The results of rapid detection of V.parahaemolyticus in marine products by CHROMagar vibrio colored medium are consistent with those by PCR.