Enteroaggregative Escherichia coli: A Pathogen Bridging the North and South

Abstract

Enteroaggregative Escherichia coli (EAEC) is a heterogeneous emerging enteric pathogen identified during the 1980s when EAEC strains were isolated from cases of acute and persistent diarrhea among infants in developing countries as well as traveler’s diarrhea. Subsequently, EAEC strains were linked with foodborne outbreaks and diarrhea illness in adults and children from industrialized countries and HIV-infected subjects, and with the stunting of malnourished children living in impoverished countries. Today, EAEC is increasingly recognized as a major cause of acute diarrhea requiring hospitalization in children and of traveler’s diarrhea worldwide. The defining phenotype of EAEC strains is the aggregative adherence (AA) pattern on epithelial cells. The role of AggR, a transcriptional regulator of several EAEC virulence genes, is a key factor in both understanding EAEC pathogenesis and defining typical EAEC (tEAEC) strains. The distribution of EAEC virulence genes among these strains is highly variable, and the identification of key virulence genes and their function in the setting of enteric disease presents ongoing challenges.