Molecular analysis on Vibrio parahaemolyticus strains isolated from patients in Nanjing, Jiangsu, 2016–2019

  Objective  To understand the molecular characteristics of Vibrio parahaemolyticus strains in Nanjing, Jiangsu, and provide evidence for the prevention and control of human infection with V. parahaemolyticus.

  Methods  Clinical isolates from diarrhea and food poisoning patients were collected from 2016 to 2019. Virulence genes of tlh, tdh, trh, toxRS/new and ORF8 were detected by polymerase chain reaction (PCR). Molecular types were analyzed by multilocus sequence typing (MLST).

  Results  A total of 93 V. parahaemolyticus strains were collected. O3∶K6 was the predominant serotype (65 strains, 69.9%). Virulence genes screening revealed that all isolates carried tlh gene. A total of 73 strains with tdh+trh-toxRS/new+ were classified as pandemic strains, and 5 non-pandemic strains with tdh-trh- were non-pathogenic strains. A total of 13 STs were detected, of which ST3 was predominant (68/93, 73.1%).

  Conclusion  Molecular analysis on V. parahaemolyticus revealed that ST3 was predominant, and both the pandemic and non-pandemic strains were distributed in Nanjing.