Phylogenetic background of attaching and effacing Escherichia coli isolates from animals

Detection and distribution of eae gene in forty-four attaching and effacing Escherichia coli (AEEC) strains of animal origin were investigated. Association of distinct intimin alleles with phylogenetic background were assessed among strains in comparison with different serogroups. Phylogenetic analysis showed that 31 EHEC/eae+ STEC strains belong to groups A, B1 and E, 13 EPEC strains segregated in B1 and B2. Moreover, group A possessed the eae γ2/θ type, group B1 the eae β1, eae κ, eae ζ, and eae ɛ types, group B2 the eae α1, eae α2 and eae ι types, while the group E possessed the eae γ1 type. The presence of numerous eae-types show that EPEC and EHEC/eae+ STEC tested have a high genetic homology within each phylogenetic group.