title: A complete view of the genetic diversity of the Escherichia coli O-antigen biosynthesis gene cluster.
abstract: The O antigen constitutes the outermost part of the lipopolysaccharide layer in Gram-negative bacteria. The chemical composition and structure of the O antigen show high levels of variation even within a single species revealing itself as serological diversity. Here, we present a complete sequence set for the O-antigen biosynthesis gene clusters (O-AGCs) from all 184 recognized Escherichia coli O serogroups. By comparing these sequences, we identified 161 well-defined O-AGCs. Based on the wzx/wzy or wzm/wzt gene sequences, in addition to 145 singletons, 37 serogroups were placed into 16 groups. Furthermore, phylogenetic analysis of all the E. coli O-serogroup reference strains revealed that the nearly one-quarter of the 184 serogroups were found in the ST10 lineage, which may have a unique genetic background allowing a more successful exchange of O-AGCs. Our data provide a complete view of the genetic diversity of O-AGCs in E. coli showing a stronger association between host phylogenetic lineage and O-serogroup diversification than previously recognized. These data will be a valuable basis for developing a systematic molecular O-typing scheme that will allow traditional typing approaches to be linked to genomic exploration of E. coli diversity.
authors.affiliation: Department of Animal and Grassland Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan iguchi@med.miyazaki-u.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Iguchi
authors.affiliation: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo 162-8640, Japan.
authors.forename: Sunao
authors.initials: S
authors.lastname: Iyoda
authors.affiliation: Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan.
authors.forename: Taisei
authors.initials: T
authors.lastname: Kikuchi
authors.affiliation: Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan Division of Bioenvironmental Science, Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan.
authors.forename: Yoshitoshi
authors.initials: Y
authors.lastname: Ogura
authors.affiliation: Division of Bioenvironmental Science, Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Katsura
authors.affiliation: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo 162-8640, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohnishi
authors.affiliation: Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan Division of Bioenvironmental Science, Frontier Science Research Center, University of Miyazaki, Miyazaki 889-1692, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hayashi
authors.affiliation: Pathogen Genomics, The Wellcome Trust Sanger Institute, Cambridge CB10 1SA, UK Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Thomson
mesh_terms: D030541:Databases, Genetic; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D016680:Genome, Bacterial / Q000502:physiology; D005810:Multigene Family / Q000502:physiology*; D019081:O Antigens / Q000096:biosynthesis / Q000235:genetics*; D010802:Phylogeny
chemical_list: D029968:Escherichia coli Proteins; D019081:O Antigens
keywords: E. coli; O serogroup; O-antigen biosynthesis gene cluster; genomic diversity; horizontal gene transfer