ABSTRACT
Bacterial diarrheal diseases are a very important problem for human health, causing the death of many people, especially infants and children, each year, particularly in developing countries. It has long been known that certain strains of Escherichia coli can cause acute diarrhea in humans and animals. At least five kinds of E. coli [enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli (EHEC), and enteroaggregative E. coli (EAggEC)] have been clearly identified as diarrheal pathogens. Recently, it became possible to understand the pathogenicity of these E. coli at a molecular level.
