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Gut 47:377-381 doi:10.1136/gut.47.3.377
  • Intestinal infection

Enterohaemorrhagic Escherichia coliO157:H7 target Peyer's patches in humans and cause attaching/effacing lesions in both human and bovine intestine

Abstract

BACKGROUND EnterohaemorrhagicEscherichia coli (EHEC) constitute a significant risk to human health worldwide, and infections, particularly with serogroup O157:H7, are associated with consumption of a variety of food and water vehicles, particularly food of bovine origin. EHEC cause acute gastroenteritis, bloody diarrhoea, and haemorrhagic colitis; up to 10% of cases develop severe complications, including the haemolytic uraemic syndrome, with a 5% case fatality. A virulence characteristic of enteropathogenic E coli, the attaching/effacing lesion, is considered to be important in EHEC. However, although EHEC produce this lesion on cultured human cells, this has not been demonstrated on human intestinal mucosal surfaces. In addition, the initial site(s) of colonisation of EHEC in humans is not known.

AIMS To assess the association of EHEC O157:H7 with paediatric and bovine intestine using in vitro organ culture and determine if attaching/effacing lesions occur.

METHODS Ultrastructural analysis of in vitro intestinal organ cultures of human small and large intestine was used to investigate adhesion of O157:H7 EHEC to intestinal surfaces. Bovine intestinal organ culture was used to examine the pathology produced by the same EHEC strain in cattle.

RESULTS The study showed that EHEC O157:H7 adhered to human intestinal mucosa. Binding and attaching/effacing lesion formation of O157:H7 in humans was restricted to follicle associated epithelium of Peyer's patches. The same strain caused attaching/effacing lesions on bovine mucosa.

CONCLUSIONS O157:H7 targets follicle associated epithelium in humans where it causes attaching/effacing lesions. The same human isolate can cause attaching/effacing lesions in cattle, indicating that similar pathogenic mechanisms operate across human and bovine species

Footnotes

  • Abbreviations used in this paper:
    EHEC
    enterohaemorrhagicEscherichia coli
    A/E
    attaching/effacing
    HUS
    haemolytic uraemic syndrome
    EPEC
    enteropathogenicE coli
    LEE
    locus of enterocyte effacement
    Esps
    EPEC secreted proteins
    Tir
    translocated intimin receptor
    PER
    plasmid encoded regulator
    IVOC
    in vitro organ culture
    SEM
    scanning electron microscopy
    TEM
    transmission electron microscopy
    FAE
    follicle associated epithelium
    Stx
    shiga toxin