Genome sequence and comparative analysis of a Vibrio cholerae O139 strain E306 isolated from a cholera case in China

BACKGROUND Vibrio cholerae is a human intestinal pathogen and V. cholerae of the O139 serogroups are responsible for the current epidemic cholera in China. In this work, we reported the whole genome sequencing of a V. cholerae O139 strain E306 isolated from a cholera patient in the 306th Hospital of PLA, Beijing, China. RESULTS We obtained the draft genome of V. cholerae O139 strain E306 with a length of 4,161,908 bps and mean G + C content of 47.7%. Phylogenetic analysis indicated that strain E306 was very close to another O139 strain, V. cholerae MO10, which was isolated during the cholera outbreak in India and Bangladesh. However, unlike MO10, strain E306 harbors the El Tor-specific RS1 element with no pre-CTX prophage (VSK), very similar to those found in some V. cholerae O1 strains. In addition, strain E306 contains a SXT/R391 family integrative conjugative element (ICE) similar to ICEVchInd4 and SXT MO10, and it carries more antibiotic resistance genes than other closest neighbors. CONCLUSIONS The genome sequence of the V. cholerae O139 strain E306 and its comparative analysis with other V. cholerae strains we present here will provide important information for a better understanding of the pathogenicity of V. cholerae and their molecular mechanisms to adapt different environments.