title: Genomic diversity of enterohemorrhagic Escherichia coli O157 revealed by whole genome PCR scanning.
abstract: Enterohemorrhagic Escherichia coli O157 is one of the leading worldwide public health concerns, causing large outbreaks of hemorrhagic colitis as well as numerous small outbreaks and sporadic cases. The variability of restriction enzyme-digestion patterns of O157 genomes, which is widely used to distinguish strains in the molecular epidemiology of O157 infections, suggests the presence of some genomic diversity among the strains. Based on the complete genome sequence of O157 Sakai, we analyzed the whole genome structures of eight O157 strains displaying diverse XbaI-digestion patterns by a systematic PCR analysis that we have named whole genome PCR scanning. This analysis identified not only the O157-specific sequences that are highly conserved among the strains, but also revealed an unexpectedly high degree of genomic diversity. In particular, prophages, including Shiga toxin-transducing phages, exhibited extensive structural and positional diversity, implying that variation of bacteriophages is a major factor in generating genomic diversity among the O157 lineage.
authors.affiliation: Department of Microbiology, Miyazaki Medical College, 5200 Kiyotake, Miyazaki 899-1692, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohnishi
authors.forename: Jun
authors.initials: J
authors.lastname: Terajima
authors.forename: Ken
authors.initials: K
authors.lastname: Kurokawa
authors.forename: Keisuke
authors.initials: K
authors.lastname: Nakayama
authors.forename: Takahiro
authors.initials: T
authors.lastname: Murata
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Tamura
authors.forename: Yoshitoshi
authors.initials: Y
authors.lastname: Ogura
authors.forename: Haruo
authors.initials: H
authors.lastname: Watanabe
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hayashi
mesh_terms: D002876:Chromosomes, Bacterial; D003090:Coliphages / Q000235:genetics; D019453:Escherichia coli O157 / Q000235:genetics*; D014644:Genetic Variation; D016680:Genome, Bacterial; D016133:Polymerase Chain Reaction; D022621:Shiga Toxin / Q000235:genetics
chemical_list: D022621:Shiga Toxin