Abstract

Enterotoxigenic Escherichia coli (ETEC) cause toxin-mediated diarrhea, which requires that ETEC attaches to epithelial cells using a diverse repertoire of adhesins generically named as colonization factor antigens (CFs). Currently, 22 CFs variants have been identified, displaying different types of structures (fimbriae, fibers and non-fimbrial), which are assembled and displayed at the bacterial surface by three different mechanisms. To date, there is no an effective therapy to prevent ETEC-caused diarrhea and investigators have considered CFs as suitable potential basis of vaccine formulations. In this chapter, we describe the CFs carried by human ETEC strains, addressing structural and functional features as well as their distribution in clinical isolates as determined by epidemiological studies. Furthermore, three non-classical/non-fimbrial ETEC adhesins are described. The information presented here is an overview about human ETEC adherence mechanisms and about how basic and epidemiological research has advanced to obtain crucial data for the design of a therapy to effectively prevent ETEC-caused diarrhea