[Pathogenesis of enterohaemorrhagic Escherichia coli infection].

EHEC is an emergent pathogen which causes haemorrhagic colitis and complications of the potentially fatal HUS. The main virulence factors are the phage-encoded Shiga toxin and the intimate attachment to host cells. Shiga toxin affects cells not only by inhibiting protein biosynthesis but also through the induction of signalling cascades leading to apoptosis. The locus of enterocyte effacement (LEE) encodes a type III secretion system that translocates bacterial effector proteins into the host cell cytoplasm. Intimate attachment is mediated through interactions of the bacterial outer-membrane protein Intimin and the translocated intimin receptor (Tir) on the host cells. Recently, a very rare serogroup strain in humans of E. coli 0104, which carries a stx2a gene in a typical type of EAggEC, appeared in EU and caused a big outbreak of haemorrhagic colitis and HUS.