Bacteremia Caused by a Serotype Ob5 Vibrio cholerae Strain in a Cirrhotic Patient in China.

Abstract

The increasing incidence of non-O1/non-O139 Vibrio cholerae (NOVC) has been observed worldwide. However, septicemia caused by NOVC remains a rare condition that has received limited attention. Currently, there are no established treatment guidelines for bloodstream infections caused by NOVC, and the understanding of this condition mainly relies on individual case reports. Although NOVC bacteremia can be fatal in a small percentage of cases, knowledge about its microbiological features remains limited. Here, we present a case of V. cholerae septicemia caused by NOVC in a 46-year-old man with chronic viral hepatitis and liver cirrhosis. The isolated strain, named V. cholerae VCH20210731 and classified as a new sequence type (ST), ST1553, was found to be susceptible to most of the antimicrobial agents tested. O-antigen serotyping of V. cholerae VCH20210731 revealed that it belonged to serotype Ob5. Interestingly, the ctxAB genes, which are typically associated with V. cholerae, were absent in VCH20210731. However, the strain possessed 25 other potential virulence genes, such as hlyA, luxS, hap, and rtxA. The resistome of V. cholerae VCH20210731 included several genes, including qnrVC4, crp, almG, and parE. Nevertheless, susceptibility testing demonstrated that the isolate was susceptible to most of the antimicrobial agents tested. Phylogenetic analysis indicated that the closest strain to VCH20210731 was strain 120 from Russia, differing by 630 single-nucleotide polymorphisms (SNPs). Our findings contribute to the understanding of the genomic epidemiological characteristics and antibiotic resistance mechanisms of this invasive bacterial pathogen. IMPORTANCE This study highlights the discovery of a novel ST1553 V. cholerae strain in China, providing valuable insights into the genomic epidemiology and global transmission dynamics of V. cholerae. It is important to note that clinical presentations of NOVC bacteremia can vary significantly, and the isolates demonstrate genetic diversity. Consequently, health care professionals and public health experts should remain vigilant about the potential for infection with this pathogen, particularly considering the elevated prevalence of liver disease in China.