Enteroaggregative Escherichia coli infection

Purpose of review To review studies that improve the current knowledge on the epidemiology, virulence factors, detection, and chronic complications of enteroaggregative Escherichia coli (EAEC) infection. Recent findings EAEC infection is an important cause of diarrhea in outbreak and non-outbreak settings in developing and developed countries. In the USA, EAEC is one of the most common bacterial pathogens identified in cases of diarrhea not associated with immunodeficiency or foreign travel. Important advances have been made in the understanding of the pathogenesis of this enteropathogen. The extracellular matrix proteins fibronectin, laminin, and collagen IV have been shown to function as receptors for adherence frimbriae. A distinct aggregative adherence pilin hdaA has been identrified. The diagnosis of EAEC depends on the observation of the characteristic 'stacked-brick' like adhesion pattern when co-cultured with HEp-2 cells. At the molecular level, strains demonstrating the aggregative phenotype are heterogeneous; however, several virulence factors can be detected by polymerase chain reaction. Several EAEC proteins have shown antigenicity and could become vaccine candidates. Recently, infection with EAEC has been implicated in the development of irritable bowel syndrome, but this remains to be confirmed. Summary There has been significant progress in understanding the pathogenesis and clinical profile of EAEC infection.