Characterization of the pathogenome and phylogenomic classification of enteropathogenic Escherichia coli of the O157:non-H7 serotypes

Pathog Dis. 2015 Jul;73(5):ftv033. doi: 10.1093/femspd/ftv033. Epub 2015 May 10.


Escherichia coli of the O157 serogroup are comprised of a diverse collection of more than 100 O157:non-H7 serotypes that are found in the environment, animal reservoir and infected patients and some have been linked to severe outbreaks of human disease. Among these, the enteropathogenic E. coli O157:non-H7 serotypes carry virulence factors that are hallmarks of enterohemorrhagic E. coli, such as causing attaching and effacing lesions during human gastrointestinal tract infections. Given the shared virulence gene pool between O157:H7 and O157:non-H7 serotypes, our objective was to examine the prevalence of virulence traits of O157:non-H7 serotypes within and across their H-serotype and when compared to other E. coli pathovars. We sequenced six O157:non-H7 genomes complemented by four genomes from public repositories in an effort to determine their virulence state and genetic relatedness to the highly pathogenic enterohemorrhagic O157:H7 lineage and its ancestral O55:H7 serotype. Whole-genome-based phylogenomic analysis and molecular typing is indicative of a non-monophyletic origin of the heterogeneous O157:non-H7 serotypes that are only distantly related to the O157:H7 serotype. The availability of multiple genomes enables robust phylogenomic placement of these strains into their evolutionary context, and the assessment of the pathogenic potential of the O157:non-H7 strains in causing human disease.

Keywords: O157:non-H7; enteropathogenic E. coli (EPEC); genotyping; pathogenome evolution.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Escherichia coli Infections / microbiology
  • Escherichia coli O157 / classification*
  • Escherichia coli O157 / genetics*
  • Escherichia coli O157 / isolation & purification
  • Escherichia coli O157 / pathogenicity
  • Genetic Variation*
  • Genome, Bacterial
  • Genotype
  • Humans
  • Meat / microbiology
  • Molecular Sequence Data
  • Molecular Typing
  • Phylogeny
  • Sequence Analysis, DNA
  • Serogroup*
  • Virulence Factors / genetics*
  • Water Microbiology


  • Virulence Factors