Verotoxic Escherichia coli in human disease

Verotoxin-producing E. coli (most frequently E. coli 0157) have been implicated in the pathogenesis of diarrhea, hemorrhagic colitis, hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. Cattle, meat products, and other sources have been found to harbor these organisms. Isolation of E. coli 0157:H7 on MacConkey-sorbitol agar is diagnostic, yet the bacteria are difficult to detect after the first week of infection. Enzyme linked immunosorbent assays (ELISAs) can detect verotoxin in fecal filtrates in the absence of viable bacteria. Serologic evidence has also been used to support the diagnosis of verotoxin-associated infection. Evidence supporting the etiologic role of different verotox-ins is reviewed. Treatment remains supportive since the use of antibiotics and antimotility agents can lead to poorer outcomes. Recommendations for prevention are presented.