Subtyping of virulence genes in verocytotoxin-producing Escherichia coli (VTEC) other than serogroup O157 associated with disease in the United Kingdom

Verocytotoxin-producing Escherichia coli (VTEC) causes a wide spectrum of disease in humans, from mild diarrhoea to haemolytic uraemic syndrome (HUS). The verocytotoxin (vtx) and intimin (eae) genes of VTEC strains, other than those of serogroup O157, were subtyped to identify common properties that may be associated with increased pathogenicity. Strains were isolated from patients with HUS, those with diarrhoea or from asymptomatic individuals. Strains of VTEC that carried vtx₂ gene subtypes vtx₂ and vtx_2c were most commonly associated with HUS, whereas strains from patients with less severe disease and from the healthy control group were more likely to have vtx_1c or vtx_2d genes. The eae gene was detected more frequently in strains isolated from HUS patients than in those associated with cases of diarrhoea; β-intimin was the most common intimin subtype in strains isolated from both groups of patients. None of the strains from the healthy control group carried the eae gene.