Abstract

Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrhea in infants and children in developing countries. The aim of this study was to investigate the frequency of EPEC in children with diarrhea by polymerase chain reaction (PCR) method targeting the eae gene. The presence of virulence gene including bfpA was also investigated by PCR, for the differentiation of typical and atypical EPEC strains. We also sought to determine the presence of virulence gene including efa-1, fimH and lpfDo113 of the isolated strains. Stool samples were collected from 313 less than 5 years old children with diarrhea at Shahid Beheshti Hospital, Kashan, Iran, from November 2009 to May 2010. Specimens were examined by PCR test to determine the eae gene to detect of EPEC pathotype and also the frequency of genes coding virulence factors of EPEC such as bfpA, efa-1, fimH and lpfDo113 were analyzed. Results showed that 51 cases (28.6%) out of 178E. coli isolated were EPEC. The percentage of isolated EPECs carrying virulence genes were bfpA (tEPEC) (11.8%), efa1 (2%), fimH (98%) and lpfDo113 (13.7%). Variable frequency of EPEC virulence factors isolated from children with diarrhea needs further studies for creating epidemiological map of diarrheal infections caused by EPEC.

Key words: Enteropathogenic Escherichia coli, virulence genes, diarrhea, children, polymerase chain reaction.