Typing of bfpA genes of enteropathogenic Escherichia coli isolated in Thailand and Japan by heteroduplex mobility assay.

We developed a rapid genetic approach for screening bfpA variants of enteropathogenic E. coli (EPEC) using a heteroduplex mobility assay (HMA). A total of 204 human EPEC strains were isolated in Thailand and Japan. Of 34 bfpA-positive EPEC strains, bfpA variants were classified into 5 HMA-types. Different HMA-types were found in EPEC of the same serotypes. The results suggest that HMA is a simple and easy method to analyze polymorphism of bfpA gene, and can be used in laboratories without large apparatus such as sequencers.