Phenotypic and genotypic characteristics of Escherichia coli strains of non-enteropathogenic E-coli (EPEC) serogroups that carry eae and lack the EPEC adherence factor and shiga toxin DNA probe sequences

This study was conducted to characterize the virulence potential of 59 Esch erichia coli strains carrying eae and lacking the enteropathogenic E. coli adherence factor and Shiga toxin probe sequences. In hybridization studies, all strains carried the locus of enterocyte effacement (LEE)-associated DN A sequences. Of the other 15 virulence DNA sequences tested, hly was the mo st frequent (44.1%); 17 combinations of these sequences were found, but str ains carrying eae only (eae profile) were the most frequent (35.6%). Except for 1 cytodetaching strain, all others adhered to HeLa and Caco-2 cells, m ost of which (similar to 75.0%) showed variations of the localized adherenc e pattern. Actin accumulation was detected in 75.9% of the nondetaching str ains. Most strains had LEE, probably inserted in pheU (49.2%), and presente d a nontypeable intimin (83.1%). Translocated intimin receptor-derived DNA sequences correlated with enteropathogenic and enterohemorrhagic E. coli in 61.0% and 32.0% of the strains, respectively. Thirty-five different seroty pes were found. Only strains with the eae profile were associated with diar rhea (P = .039).