Purpose of review: Enteroaggregative Escherichia coli (EAEC) is an emerging diarrheal pathogen, implicated in traveler's diarrhea and endemic diarrhea in developing and industrialized countries. Understanding of EAEC pathogenesis is rapidly increasing, and advances are proving relevant to epidemiologic and clinical investigations.
Recent findings: The pathogenesis of EAEC infection comprises colonization of the intestinal mucosa with elaboration of enterotoxins and cytotoxins. In addition, EAEC infections elicit mucosal inflammation, which can be observed in infected subjects. A large set of EAEC virulence factors is under the control of a global regulator of EAEC virulence, called AggR. AggR controls expression of adherence factors, a dispersin protein, and a large cluster of genes encoded on the EAEC chromosome.
Summary: Identification of AggR or members of the AggR regulon may identify pathogenic EAEC strains, called typical EAEC. Epidemiologic and clinical investigations in many settings should now include detection of typical EAEC.