Enterotoxigenic Escherichia coli

The enterotoxigenic Escherichia coli (ETEC) constitute a diverse pathotype which shares the ability to secrete and effectively deliver heat-labile (LT) and/or heat-stable (ST) enterotoxins to host epithelial receptors. Respectively, these toxins stimulate production of cAMP and cGMP within host cells, and both of these cyclic nucleotides activate the cystic fibrosis transmembrane conductance regulator (CFTR) resulting in net efflux of salt and water into the intestinal lumen. Although discovered now more than 40 years ago, new ETEC virulence factors and critical features of the molecular pathogenesis of these organisms continue to emerge. Presently, there is no broadly protective vaccine for ETEC. However recent findings may inform novel approaches to vaccine development for these important pathogens.