title: The Locus of Enterocyte Effacement and Associated Virulence Factors of Enterohemorrhagic Escherichia coli.
abstract: A subset of Shiga toxin-producing Escherichia coli strains, termed enterohemorrhagic E. coli (EHEC), is defined in part by the ability to produce attaching and effacing (A/E) lesions on intestinal epithelia. Such lesions are characterized by intimate bacterial attachment to the apical surface of enterocytes, cytoskeletal rearrangements beneath adherent bacteria, and destruction of proximal microvilli. A/E lesion formation requires the locus of enterocyte effacement (LEE), which encodes a Type III secretion system that injects bacterial proteins into host cells. The translocated proteins, termed effectors, subvert a plethora of cellular pathways to the benefit of the pathogen, for example, by recruiting cytoskeletal proteins, disrupting epithelial barrier integrity, and interfering with the induction of inflammation, phagocytosis, and apoptosis. The LEE and selected effectors play pivotal roles in intestinal persistence and virulence of EHEC, and it is becoming clear that effectors may act in redundant, synergistic, and antagonistic ways during infection. Vaccines that target the function of the Type III secretion system limit colonization of reservoir hosts by EHEC and may thus aid control of zoonotic infections. Here we review the features and functions of the LEE-encoded Type III secretion system and associated effectors of E. coli O157:H7 and other Shiga toxin-producing E. coli strains.
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Stevens
authors.affiliation: MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Gad M
authors.initials: GM
authors.lastname: Frankel
mesh_terms: D001422:Bacterial Adhesion; D020895:Enterocytes / Q000382:microbiology*; D054324:Enterohemorrhagic Escherichia coli / Q000235:genetics* / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics*; D054884:Host-Pathogen Interactions; D006801:Humans; D010750:Phosphoproteins / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D029968:Escherichia coli Proteins; C457340:LEE protein, E coli; D010750:Phosphoproteins; D037521:Virulence Factors