Characterization of enteroadherent-aggregative Escherichia coli, a putative agent of diarrheal disease

Abstract

Escherichia coli that exhibit the aggregative pattern of adherence to HEp-2 cells (enteroadherent-aggregative E. coli [EA-AggEC]) have been epidemiologically incriminated as a cause of diarrhea. We undertook a preliminary microbiological and pathogenetic characterization of 42 isolates of this putative pathogen. The strains were negative by tests with DNA probes for enteropathogenic, enterotoxigenic, enteroinvasive, and enterohemorrhagic E. coli and, by serotype, did not fit these categories. Thirty-nine of 42 strains had a 55-65-megadalton plasmid; many shared DNA homology. With one representative strain, plasmid transfer was accompanied by transfer of smooth lipopolysaccharide, fimbriae ex..