Drug sensitivity and genomic characterization of non-O1/non-O139 Vibrio cholerae of human isolates from Hunan province, China, 2018−2021

  Objective  To investigate the drug sensitivity and genomic characteristics of non-O1/non-O139 Vibrio cholerae isolated from patients in Hunan Province during 2018−2021.

  Methods  Four non-O1/non-O139 V. cholerae isolated from intestinal samples of diarrhea cases and three non-O1/non-O139 V. cholerae isolated from blood samples of non-diarrhea cases in Hunan province from 2018 to 2021 were selected for drug sensitivity test and genome sequencing to analyze their drug sensitivity and genomic characteristics.

  Results  Three strains isolated from blood samples were sensitive to ampicillin, norfloxacin, ceftriaxone, meropenem, minocycline, compound sulfamethoxazole, gentamicin, cefotaxime, nalidixicacid and ciprofloxacin, one strain was intermediate to tetracycline, and one strain was resistant to chloramphenicol. The 4 strains isolated from stool samples were sensitive to norfloxacin, ceftriaxone, meropenem, minocycline, compound sulfamethoxazole, gentamicin and cefotaxime. One strain was intermediate to tetracycline and chloramphenicol, one strain was resistant to chloramphenicol, and two strains were resistant to ampicillin, ciprofloxacin and nalidixic acid; among which 1 strain was resistant to ampicillin, nalidixic acid and ciprofloxacin; and 1 strain was resistant to ampicillin, Nalidixic acid, ciprofloxacin and chloramphenicol. The genome sequences of 7 non-O1/non-O139 V. cholerae strains showed significant diversity, but some strains were highly similar in core and pangenome. No ctxAB gene,VPI-1 and VSPII genome islands were detected in the genome sequences. Strains isolated from stool carried 4 to 8 resistance genes, while strains isolated from blood carried 1 to 2 resistance genes.

  Conclusion  The genome of non-O1/non-O139 V. cholerae in Hunan province showed obvious diversity, and the strains were resistant to a variety of antimicrobial agents. It is necessary to strengthen the monitoring of genome variation and drug sensitivity of non-O1/non-O139 V. cholerae in diarrhea cases, food and environmental water.