DETECTION AND CHARACTERIZATION OF THE EAE GENE OF SHIGA-LIKE TOXIN-PRODUCING ESCHERICHIA-COLI USING POLYMERASE CHAIN-REACTION

In this study, the polymerase chain reaction (PCR) was used in the det ection of the attaching and effacing (eae) gene of Shiga-like toxin-pr oducing Escherichia coli (SLT-EC). Oligonucleotide primers, complement ary to the 5' portion of the eae gene of the enteropathogenic E. coli E2348/69 (0127:H6) and of SLT-EC CL8 and EDL933 (0157:H7), generated P CR products of the predicted sizes with DNA from the majority of human clinical SLT-EC strains tested from 0 serogroups 5, 26, 103, 111, 121 , 128, 145, and 157; all SLT-EC strains of O serogroups 5, 26, and 111 from cattle; and a minority of porcine SLT-EC strains (one strain eac h from O serogroups 107 and 130 and one rough strain). Five HaeIII dig estion profiles were obtained for PCR products generated by amplificat ion of a 2.3-kb DNA fragment from the 5' end of eae. The HaeIII profil es for SLT-EC O serogroups, such as 26, 103, and 157, differed from ea ch other but were consistent among strains within these O serogroups. Oligonucleotide primer pairs complementary to the 3' end of either the 0127:H6 E. coli or the O157:H7 eae nucleotide sequence only amplified DNA from E. coli strains from a few of the SLT-EC O serogroups examin ed. One primer pair with homology to the 3' nucleotide sequence of eae from E. coli O157:H7 appeared to be relatively specific for this O se rogroup by PCR. No PCR products were obtained in amplification experim ents with the eae primers using DNA from human SLT-EC of O serogroups 38 (1 of 1) and 91 (3 of 3), 15 of 15 SLT-EC strains from edema diseas e, or 29 of 29 non-SLT-EC strains from pigs and calves with diarrhea.