US Gulf-like toxigenic O1 Vibrio cholerae causing sporadic cholera outbreaks in China

J Infect. 2016 May;72(5):564-72. doi: 10.1016/j.jinf.2016.02.005. Epub 2016 Feb 23.

Abstract

Objectives: Cholera is potentially a life threatening disease caused by toxigenic Vibrio cholerae. Here we report the identification and characterisation of 76 non-7th pandemic clone O1 V. cholerae isolates including 65 clinical isolates from diarrhoeal patients from 2005 to 2014 in Zhejiang Province, China.

Methods: We used multilocus sequence typing (MLST) to characterise 65 V. cholerae isolates. Pulse-Field Gel Electrophoresis (PFGE) was performed on a subset of the isolates and whole-genome sequencing was done on 13 isolates.

Results: MLST separated 65 isolates into 19 sequence types (STs). Thirty three isolates belonged to ST75 which also contains the US Gulf Coast clone. PFGE separated the 33 isolates into 16 pulsotypes. Whole genome sequencing of 10 ST75 isolates showed that the US Gulf Coast clone and the Chinese ST75 isolates can be separated into two distinct lineages, ST75a and ST75b. All Zhejiang ST75 isolates were ST75b.

Conclusion: PFGE and genome sequencing confirmed the linked cases and identified small outbreaks caused by ST75b. The emergence and potential spread of ST75b may pose significant threat to public health. Epidemiological surveillance is required to further understand its epidemic potential.

Keywords: China cholera; Genome; Toxigenic O1 Vibrio cholerae; US Gulf-like clone; ctx prophage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • China / epidemiology
  • Cholera / epidemiology*
  • Cholera Toxin / metabolism*
  • Disease Outbreaks*
  • Electrophoresis, Gel, Pulsed-Field
  • Genotype
  • Humans
  • Molecular Epidemiology
  • Multilocus Sequence Typing
  • Sequence Analysis, DNA
  • Vibrio cholerae O1 / classification
  • Vibrio cholerae O1 / genetics
  • Vibrio cholerae O1 / isolation & purification*
  • Vibrio cholerae O1 / metabolism

Substances

  • Cholera Toxin