[Genomic characteristics of toxigenic Vibrio cholerae O139 in Henan Province, 2001-2024].

Objective

To explore the antimicrobial resistance phenotypes and whole genome characteristics of toxigenic Vibrio cholerae O139 strains in Henan Province, elucidate the evolving epidemiological trends of cholera outbreaks, and decipher molecular genetic variation patterns of the pathogen, thereby providing a reference for cholera prevention and control in the region.

Methods

Drug susceptibility assay, whole genome sequencing assay, and bioinformatics analysis of 11 toxigenic Vibrio cholerae O139 strains isolated in Henan Province from 2001 to 2024.

Results

All 11 strains were multi-drug resistant strains, resistant to all three antimicrobial drugs, polymyxin, nalidixic acid, and streptomycin, and all of them carried multi-drug resistant genes; all strains were ST69-type, and all of them carried the ctxA/B genes, sequence of CTXΦ phage, the VSP-Ⅰ gene island, VSP-Ⅱ gene island, the VPI-1 pathogenicity island, and the virulence genes ctxB, tcpA, and rstR carried by the strain are all of the El Tor type; the analysis of single-nucleotide polymorphisms (SNP) evolutionary tree revealed that 11 Vibrio cholerae strains were most closely related to Vibrio cholerae O139 strains in Taiwan.

Conclusions

Using whole genome sequencing technology, it was revealed that all the outbreak strains of cholera in different regions of Henan Province carry multiple drug resistance and virulence genes, with highly similar genomic features and minor SNP differences between strains. It suggests that strengthened surveillance and early warning mechanisms targeting these strains are critically warranted.