Enteropathogenic and enterohaemorrhagic Escherichia coli: more subversive elements

Enteropathogenic (EPEC) and enterohaemorrhagic Escherichia coli (EHEC) cons titute a significant risk to human health worldwide. Both pathogens coloniz e the intestinal mucosa and, by subverting intestinal epithelial cell funct ion, produce a characteristic histopathological feature known as the 'attac hing and effacing' (A/E) lesion. Although EPEC was the first E. coli to be associated with human disease in the 1940s and 1950s, it was not until the late 1980s and early 1990s that the mechanisms and bacterial gene products used to induce this complex brush border membrane lesion and diarrhoeal dis ease started to be unravelled. During the past few months, there has been a burst of new data that have revolutionized some basic concepts of the mole cular basis of bacterial pathogenesis in general and EPEC pathogenesis in p articular. Major breakthroughs and developments in the genetic basis of A/E lesion formation, signal transduction, protein translocation, host cell re ceptors and intestinal colonization are highlighted in this review.