Gels showing the results of a multiplex polymerase chain reaction (PCR) assay for enteropathogenic Escherichia coli (EPEC), Shiga toxin–producing E. coli, and enterohemorrhagic E. coli (EHEC). Individual isolates from 34 specimens were subjected to a multiplex PCR as described in the text. Each specimen, separated by yellow vertical lines, consists of 3 individual isolates. The yellow values indicate the cycle threshold obtained for each specimen in the real-time PCR used in the initial screening for eae. The amplicons produced by the positive controls, EPEC E2348/69 (eae and bfpA) and EHEC EH48 (stx1, stx2, and ehxA) are also shown. 100 bp DNA ladder was used as a molecular size marker. Abbreviation: NTC, no template control.