Prevalence, Virulence and Antimicrobial Resistance of Vibrio cholerae in Aquatic Products and Aquaculture Environment in Shanghai

In this study, we isolated 214 Vibrio cholerae strains from aquatic (shrimp, crab, grass carp, and crucian carp) and their cultured environment in Shanghai, China. The virulence, serotype, and antimicrobial susceptibility were tested, and polymerase chain reaction (PCR) was used to detect antimicrobial resistance genes. Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) was employed for cluster analysis of the isolated strains. The results showed that V. cholerae was found in 47.9% (114/238) of aquatic samples, with the highest detection rate in shrimp (81.1%), and the detection rate was highest in summer (70.0%). Most of the strains were non-O1/O139 groups, and virulence genes rtxC and hap had the highest detection rates of 92.5% and 91.1%. Of the 214 isolates, 69.6% were multidrug-resistant (MDR). The resistance rate of V. cholerae to sulfamethoxazole, ampicillin, and erythromycin was 97.2%, 85.5%, and 70.1%, and that to imipenem, tetracyclines, and aminoglycosides was less than 5%. The MAR index ranged from 0.05 to 0.47. When V. cholerae was screened for antimicrobial resistance genes, β-lactams CARB, chloramphenicol floR, and sulfonamides sul2 were found in 19.6%, 7.9%, and 6.5% of isolates, respectively. The results of ERIC-PCR clustering showed that the isolates had a high degree of genetic diversity. The widespread distribution of virulent and MDR V. cholerae strains poses a potential threat to food safety and public health, calling for improved monitoring and control measures in the aquaculture industry.