Abstract

Vibrio parahaemolyticus is the leading cause of illness associated with seafood consumption globally. In this study, we examined 136 V. parahaemolyticus isolates from Ningbo, China for antimicrobial resistance phenotypes, genotypes, virulence factor genes ( tdh , trh , T3SS) and molecular typing. Carbenicillin resistance (100.0%) was the most prevalent in all isolates followed by ampicillin with 46.1% in aquatic, 9.2% in clinical, and 83.3% in environmental isolates. Trimethoprim-sulfamethoxazole (7.7%), streptomycin (3.1%), tetracycline (3.1%), and nalidixic acid (1.6%) resistance were only present in aquatic isolates. The virulence factor genes tdh (83.1%) and trh (10.8%) were found in clinical isolates while tdh was carried by aquatic (6.2%) and environmental (83.3%) isolates. T3SS2α genes were present in tdh + / trh − isolates and T3SS2β genes were present only in trh + isolates. Molecular typing by enterobacterial repetitive intergenic consensus-polymerase chain reaction classified our 136 isolates into nine clusters at a 0.66 similarity and aquatic isolates showed high degrees of genetic diversity. Our findings characterized the risk factors among aquatic, clinical, and environmental V. parahaemolyticus isolates from Ningbo, China. Practical Applications The threat of pathogenic Vibrio parahaemolyticus to seafood safety is more serious than ever before as antimicrobial resistance has emerged and developed globally in the past decades. This study emphasizes the antimicrobial susceptibility, virulence, and molecular characterization of aquatic, clinical, and environmental V. parahaemolyticus isolated in Ningbo, which will be helpful for improving seafood safety management.