Phenotypic and molecular characterization of Vibrio cholerae from aquatic products

Vibrio cholerae, a waterborne pathogen, causes global cholera pandemics. Data on its prevalence and antimicrobial resistance in Chinese aquatic products are limited, highlighting an urgent need for systematic surveillance. We isolated fifteen V. cholerae (25.86%, 15/58) strains isolated from Macrobrachium rosenbergii (giant freshwater prawn) collected in Zhejiang Province, China, between 2024 and 2025. The antimicrobial resistance phenotype and genotype of V. cholerae strains were characterized. Ampicillin (100%), colistin (100%), trimethoprim-sulfamethoxazole (93.33%), ceftiofur (93.33%), ceftazidime (93.33%), enrofloxacin (93.33%), and sulfisoxazole (80%) demonstrated a high resistance rate. These strains exhibited an extensively drug-resistant phenotype and were further characterized by a 100% rate of multidrug resistance. All strains harbored a range antimicrobial resistance genes including bla_VMB-1, bla_CARB-4 and drfA1. The bla_VMB-1 gene plays a critical role in mediating resistance to cephalosporin antibiotics. It located on a conjugative IncC plasmid, highlighting its potential for horizontal gene transfer. All V. cholerae isolates were identified as non-O1/non-O139 serogroups and harbored various virulence genes (hcp, hly, and rtx). In conclusion, this study demonstrates that V. cholerae causes mortality in Macrobrachium rosenbergii. The pathogen harbors diverse antimicrobial resistance genes and serves as a critical reservoir, posing a potential transmission risk to humans via the consumption of aquatic products. To mitigate potential public health risks, we recommend strengthening ongoing active surveillance and promptly formulating precise control strategies.