Objective To determine the drug resistance， main virulence genes and molecular typing of Vibrio parahaemolyticus from multiple sources in Fengxian District， Shanghai.
Methods A total of 210 strains of Vibrio parahaemolyticus were isolated in Fengxian District， Shanghai， from 2018 to 2020. Then drug susceptibility tests of 17 antibiotics， virulence gene detection of thermolabilehemolysin （tlh）， thermostable direct hemolysin （tdh） and thermostable direct hemolysin-relatedhemolysin （trh）， and pulsed-field gel electrophoresis （PFGE） were conducted.
Results A total of 147 drug-resistant strains were detected， with the drug resistance of 70.00%. Among them， 126 strains were resistant to single antibiotic， mainly resistant to CFZ； 15 strains were resistant to two antibiotics， mainly resistant to CFZ and AMP； and 6 strains of MDR， mainly resistant to AMP， SXT， CFZ， CTX， CAZ and FEP. The AMP resistance of food-borne strains was higher than that of human-derived strains （P<0.05）. All 210 strains of Vibrio parahaemolyticus carried the virulence gene tlh. Furthermore， 84 human-derived strains carried tdh （89.29%） and trh （7.14%）. In contrast， 126 food-borne strains carried trh （1.59%）， while did not carry tdh. In additionally， 173 band patterns were determined by PFGE， sharing the similarity of 48.80%‒100.00%， among which major clones were prevalent.
Conclusion Vibrio parahaemolyticus in Fengxian District has multi-drug resistance， especially the resistance to β-lactam antibiotics. The prevalence of virulence gene remains high in human-derived strains. Furthermore， major clones are prevalent in human-derived strains， though the PFGE banding patterns are generally diverse. Due to high risk of food-borne diseases， this study warrants strengthening the prevention and control against Vibrio parahaemolyticus.
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