Objective  Genomic Characteristics Analysis of Non-Toxigenic Vibrio cholerae Serogroup O1 Isolates from Ganzhou City, Providing References for Traceability and Prevention and Control of Vibrio cholerae.

Methods  The minimum inhibitory concentration (MIC) values and whole genome sequences of Vibrio cholerae were obtained using the microbroth dilution method and whole genome sequencing technology. Core genome multilocus sequence typing (cgMLST), core genome single nucleotide polymorphism typing (cgSNP), and analysis of drug resistance genes and virulence genes were performed.

Results  Four strains did not match any known ST type but were closest to ST166 and showed high homology with the VC_VC35 strain from Malaysia in 2004. The remaining six strains were divided into three ST types.The resistance rate to CT (chloramphenicol) was 100%, and the multidrug resistance rate was 70%.A total of 18 drug resistance genes of 9 types were predicted in the 10 strains, with the highest carriage rates of resistance genes for AMP (Ampicillin) and CIP (Ciprofloxacin) at 70%.All 10 strains carried the toxin-related virulence gene hlyA and the VPI-2 virulence island. They also carried varying degrees of virulence genes such as tcpA, ace, zot, acfA, mshA, pilA, nanH, luxS, acrB, and the T3SS2 secretion system with its effector proteins, as well as the VPI-1 virulence island.

Conclusion  The genomes of non-toxigenic Vibrio cholerae O1 in Ganzhou City exhibit high genetic diversity, harbor multiple drug resistance genes and virulence-associated genes, and pose a potential risk of foodborne disease outbreaks caused by non-toxigenic strains. Continuous monitoring of Vibrio cholerae in aquatic products and water sources is necessary.