ENTEROADHERENT ESCHERICHIA-COLI - A HETEROGENEOUS GROUP OF ESCHERICHIA-COLI IMPLICATED AS DIARRHEAL PATHOGENS

Despite a great expansion in our knowledge of the causative agents of infectious diarrhoea over the past 20 years, a significant proportion of diarrhoeal cases remains undiagnosed. Enteroadherent Escherichia co li are a relatively recently identified group of enteric bacteria whic h have been implicated as diarrhoeal pathogens. These organisms, defin ed by their ability to adhere to human epithelial-derived tissue cultu re cells, have been closely studied over the past 10 years and appear to be quite heterogeneous. This review summarizes our current understa nding of enteroadherent E. coli and the recognized subgroups. At least 3 distinct tissue culture cell adherence patterns have been recognize d: localized adherence, characteristic of enteropathogenic E. coli, di ffuse adherence, and aggregative adherence. Studies examining the epid emiological and pathogenic significance of the latter 2 groups, so-cal led diffusely adhering E. coli and enteroaggregative E. coli, are disc ussed in detail.