Genomic dissection of the Vibrio cholerae O-serogroup global reference strains: reassessing our view of diversity and plasticity between two chromosomes
Kazunori Murase, Eiji Arakawa, Hidemasa Izumiya, Atsushi Iguchi, Taichiro Takemura, Taisei Kikuchi, Ichirô Nakagawa, Nicholas R. Thomson, Makoto Ohnishi, Masatomo Morita
Abstract
Approximately 200 O-serogroups of Vibrio cholerae have already been identified; however, only 2 serogroups, O1 and O139, are strongly related to pandemic cholera. The study of non-O1 and non-O139 strains has hitherto been limited. Nevertheless, there are other clinically and epidemiologically important serogroups causing outbreaks with cholera-like disease. Here, we report a comprehensive genome analysis of the whole set of V. cholerae O-serogroup reference strains to provide an overview of this important bacterial pathogen. It revealed structural diversity of the O-antigen biosynthesis gene clusters located at specific loci on chromosome 1 and 16 pairs of strains with almost identical O-antigen biosynthetic gene clusters but differing in serological patterns. This might be due to the presence of O-antigen biosynthesis-related genes at secondary loci on chromosome 2.