Virulence-associated genes and molecular characteristics of non-O1/non-O139 Vibrio cholerae isolated from hepatitis B cirrhosis patients in China

Abstract

Objectives: We aimed to report virulence-associated genes and molecular characteristics of non-O1/non-O139 Vibrio cholerae isolated from hepatitis B cirrhosis patients in China.

Methods: Patient clinical data including course of disease, laboratory tests, antibiotic treatment and outcomes were collected. Antimicrobial susceptibility testing was performed and virulence-associated genes were detected by PCR. Genetic relatedness among non-O1/non-O139 V. cholerae strains was investigated by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).

Results: All three strains in this study harbored pathogenicity related genes like rtxA, rtxC, toxR, hapA, hlyA and ompW whereas they lacked ctxA, ctxB, tcpA, ompU and zot genes. None of them showed resistance to any antibiotic detected. A new allele of gyrB was submitted to the MLST database and designated as 97. Two novel sequence types (ST518 and ST519) and ST271 were identified by multilocus sequence typing (MLST). PFGE indicated considerable diversity among three non-O1/non-O139 V. cholerae strains.

Conclusions: Three sporadic cases highlight that non-O1/non-O139 V. cholerae can cause opportunistic invasiveness infection in cirrhosis patients. Pathogenicity may be related to virulence-associated genes. Timely detection and antibiotic therapy should be paid more attention to in clinic.

Keywords: Extraintestinal infection; MLST; Non-O1/non-O139 V. Cholerae; PFGE; Virulence-associated genes.