Abstract
Among Escherichia coli strains isolated from stool specimens from patients with acute diarrhea, 1.4% were found to harbor cdtB by use of enrichment cytolethal distending toxin (CDT) PCR. These isolates were identified as being enteropathogenic E. coli (EPEC). In a retrospective study using a probe hybridization assay, 6 of 138 EPEC strains were found to harbor the cdtB locus. cdtB-positive isolates mostly belong to the O86a and O127a serogroups, with the former being associated with higher expression of CDT. Pulsed-field gel electrophoresis profiles showed that the EPEC strains harboring cdtB strains are genetically diverse.