FIG. 7.

Three-stage model of EPEC pathogenesis. (A) The first stage is characterized by initial, relatively distant interaction of bacteria with the enterocyte layer. This initial attachment is thought to be mediated by the bundle-forming pilus. (B) In the second stage, eae and other genes are activated, causing dissolution of the normal microvillar structure. (C) In the third stage, the bacterium binds closely to the epithelial membrane via the protein intimin. Other bacterial gene products mediate further disruption of the cytoskeleton and phosphorylation of cellular proteins. Modified from reference 158 with permission of the publisher.