Inhibition of attaching and effacing lesion formation following enteropathogenic Escherichia coli and Shiga toxin-producing E. coli infection.

Enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) induce cytoskeletal changes in infected epithelial cells. To further characterize host cytosolic responses to infection, a series of specific cell-signaling inhibitors were employed. Initial bacterial adhesion to HEp-2 epithelial cells was not reduced, whereas alpha-actinin accumulation in infected cells was blocked by a phosphoinositide-specific phospholipase C inhibitor (ET-18-OCH3), phosphoinositide 3-kinase inhibitors (wortmannin and LY294002), and a 5-lipoxygenase inhibitor, nordihydroguaretic acid. A cyclooxygenase-2 inhibitor (NS-398), however, did not block alpha-actinin reorganization in response to EPEC and STEC infections. Understanding signal transduction responses to enteric pathogens could provide the basis for the development of novel therapeutic strategies.