Virulence characteristics and serogroup specificity of EPEC

Escherichia coli is responsible for three types of infections: urinary tract infections (UTI), neonatal meningitis, and intestinal diseases (gastroenteritis). Over 700 antigenic types (serotypes) of E. coli are recognized based on O, H, and K antigens. E. coli is best known for its ability to cause enteric infectious diseases. Five classes (virotypes) of E. coli that cause diarrheal diseases are recognized: enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), and enteroaggregative E. coli (EAggEC). Each class falls within a serological subgroup and manifests distinct features in pathogenesis. Here we shall review the virulence characteristics and serogroup specificity of EPEC. EPEC are defined as E. coli belonging to serogroups epidemiologically implicated as pathogens but whose virulence mechanism is unrelated to the excretion of typical E. coli enterotoxins. Humans, bovines, and swine can be infected, and the latter often serve as common experimental animal models. E. coli are present in the normal gut flora of these mammals.