Enteroaggregative coli: A Pathogen Bridging the North and South

Abstract

Enteroaggregative Escherichia coli (EAEC) is a heterogeneous emerging enteric pathogen. Identified during the 1980's when EAEC strains where isolated from cases of acute and persistent diarrhea among infants from developing countries and of traveler's diarrhea. Subsequently, EAEC strains were linked with foodborne outbreaks and diarrhea illness in adults and children from industrialized countries, HIV-infected subjects and stunting of malnourished poor children. Nowadays, EAEC is increasingly recognized as a major cause of acute diarrhea in children recurring hospitalization and of traveler's diarrhea worldwide. EAEC strains defining phenotype is the aggregative adherence (AA) pattern on epithelial cells. AggR a transcriptional regulator of several EAEC virulence genes has been a key factor in both understanding EAEC pathogenesis and defining typical EAEC (tEAEC) strains. EAEC virulence genes distribution among these strains is highly variable. Present challenges are the identification of key virulence genes and how they coordinately function in the setting of enteric disease.

Keywords: Escherichia coli; GI infection; aggregative adherence (AA); enteroaggregative Escherichia coli (EAEC); epidemiology; identification; pathogen; tropical medicine.

Fig. 1

Panel A HEp-2 cells cultured in DMEM/tryptone and Panel B HEp-2 infected with EAEC 042 strain showing the characteristic aggregative adherence pattern (“stacked brick” adherence)

Fig 2

Schematic representation of EAEC virulence factors and their targets on mucosal epithelium cells. Taken from Estrada-Garcia T and Navarro-Garcia F, FEMS Immunology and Medical microbiology 2012 66:281–298