Implication of virulence factors in Escherichia coil O157:H7 pathogenesis.

Since the first documented outbreak of hemorrhagic colitis caused by Escherichia coli O157:H7 in 1982, numerous publications have demonstrated or proposed putative components implicated in the pathogenesis of this gastrointestinal infection. Indeed, Escherichia coli O157:H7 pathogenesis is linked to several potential virulent factors such as verotoxins (or Shiga-like toxins), components implicated in attaching/effacing of microvilli, and the enterohemolysin phenotypes. Defining the precise molecular mechanisms involved in the pathogenesis of E. coli O157:H7 implies detailed comprehension of the virulent factors that provoke a wide range of pathophysiological symptoms. The public health significance of this emerging world-wide menace has been demonstrated by clinical complications during treatment, its low infectious dose, and the severity of clinical manifestations. In this review I describe current knowledge of Escherichia coli O157:H7 pathogenesis with emphasis on known and potential virulent factors.