Cytolethal distending toxin gene cluster in enterohemorrhagic Escherichia coli O157:H- and O157:H7: characterization and evolutionary considerations

Infect Immun. 2003 Jun;71(6):3634-8. doi: 10.1128/IAI.71.6.3634-3638.2003.

Abstract

We identified a cytolethal distending toxin (cdt) gene cluster in 87, 6, and 0% of sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157:H(-), EHEC O157:H7, and E. coli O55:H7/H(-) strains, respectively. The toxin was expressed by the wild-type EHEC O157 strains and by a cdt-containing cosmid from a library of SF EHEC O157:H(-) strain 493/89. The cdt flanks in strain 493/89 were homologous to bacteriophages P2 and lambda. Our data demonstrate that cdt, encoding a potential virulence factor, is present in the EHEC O157 complex and suggest that cdt may have been acquired by phage transduction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Toxins / genetics*
  • Base Sequence
  • Biological Evolution
  • Coliphages / genetics
  • Escherichia coli O157 / genetics*
  • Escherichia coli O157 / pathogenicity
  • Humans
  • Molecular Sequence Data
  • Multigene Family*
  • Transduction, Genetic

Substances

  • Bacterial Toxins
  • cytolethal distending toxin

Associated data

  • GENBANK/AJ508930