Characteristics of enteropathogenic Escherichia coli isolated from diarrheal patients in Beijing

Objective To understand the characteristics of enteropathogenic Escherichia coli (EPEC) isolated from diarrheal patients in Tongzhou district, Beijing. Methods The strains which were eaeA gene positive in PCR amplification were selected to conduct biochemical identification, serotyping, bfpA PCR amplification and pulsed field gel electrophoresis (PFGE) analysis. Results Only 1 isolate was identified as O126 serogroup from 20 EPEC strains isolated from adult diarrheal patients. Only 1 isolate was identified as O26 serogroup from 4 EPEC strains isolated from diarrheal children. The bfpA genes were negative in all EPEC isolates from children and adults. The PFGE patterns of 23 isolates showed high polymorphism and no obvious relation with age and gender was indicated in the phylogenic tree. Conclusion The EPEC strains isolated from patients in Tongzhou district were mainly atypical EPEC. Detection of EPEC only based on serum group would result in many misdiagnosis.