Characterization of Vibrio parahaemolyticus isolated from diarrhea patients in Jinshan District，Shanghai / 上海预防医学

ABSTRACT

Objective:To determine the distribution and epidemic characteristics of Vibrio parahaemolyticus in Jinshan District of Shanghai from 2016 through 2018. Methods:Serotype analysis，examination of virulence genes， including thermolabilehemolysin（TLH），thermostable direct hemolysin（TDH），and TDH related hemolysin（TRH），and antimicrobial susceptibility test and pulsed field gel electrophoresis （PFGE） molecular typing were performed on 218 Vibrio parahaemolyticus isolated from diarrhea patients. Results:A total of 218 strains were divided into 8 groups and 21 serotypes. Of them， 147 strains were serotyped，with O3：K6 as the most common serotype （57.3%）. All tested strains were divided into 25 clusters based on the similarity of 85% and above，in which the dominant cluster was JSVP02，and the total similarity was 56.3%-100.0%. Two hundred and one strains （92.2%） carried tdh gene，13 strains （6.0%） carried trh gene，and 7 strains were negative for both tdh and trh. A total of 35 strains were completely sensitive to 17 kinds of antibiotics，while the remaining 183 strains showed different drug resistance. Conclusion:Vibrio parahaemolyticus isolated from diarrhea patients in Jinshan District from 2016 through 2018 is diverse. Majority of the strains have TDH gene and are resistant to the first generation cephalosporins such as cefazolin and penicillin ampicillin. Construction of regional PFGE molecular typing database will facilitate screening，identification and early warning of high-risk strains.