Detection of EPEC and STEC strains isolated from children with diarrhea in Argentina.

Rectal swabs (122) from pediatric patients were analyzed by polymerase chain reaction (PCR) for the detection of EPEC and STEC. STEC isolates were tested for the presence of stx1, stx2, eae, saa and ehxA. All eae-positive samples were tested for the presence of bfpA, and antigen O was determined using the agglutination test. Int1 and Int2 were detected to identify the presence of integrons class 1 and 2, respectively. Escherichia coli was detected in 68% of the samples, of which 18.8% were STEC (2.45%) and EPEC (16.3%). Serogroups STEC O145 and EPEC O130, O113 and O157 were observed, while three strains were non-typable. None of the EPEC strains carrying tbfpA and class 1 and 2 integrons was detected in any of the samples. The results obtained are important considering the virulence profiles found in the isolated EPEC and STEC strains and the serogroups associated with disease in humans.