[Genes involved in the virulence of enterohemorrhagic Escherichia coli].

Some of the virulent genes of enterohemorrhagic E. coli(EHEC) are described. stx, bfpA, eaeA and ehxA encode an enterocytotoxin homologous to Shiga toxin, bundle-forming pilus, intimin and an RTX toxin, respectively. In pathogenesis, although bfp and eae cause diarrhea, and ehx and stx seem to cause hemorrhagic colitis and hemolytic uremic syndrome, many problems remain for prevention and treatment of these symptoms. In evolution, it is intriguining that the virulent genes of EHEC might be mediated by phages, plasmids and so on, because stx is derived from a bacterio-phage, bfpA is located in a plasmid in enteropathogenic E. coli(EPEC) though it has not yet been cloned in EHEC, eaeA is one of the genes in LEE(locus of enterocyte effacement), a putative genetic cassette ubiquitous for EPEC and EHEC, and ehxA is in a plasmid.