Abstract

Despite the fact that diarrheagenic Escherichia coli (DEC) has been identified as a major etiologic agent of diarrhea in children worldwide, few studies have beenperformed in Iran to evaluate the etiology of these organisms. To evaluate theetiology of shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC)and enteroinvasive E. coli (EIEC) in children with diarrhea in Iran a total 300 stool specimens from children with diarrhea were tested for the detection of E.coli. Out of 300 samples, 39 were identified as E. coli by biochemical tests and were subjected for serogrouping. The most prevalent serogroups among these isolates were serogroup IV, followed by III,I and II respectively. A single multiplex polymerase chain reaction (MPCR) was designed for the detection of target genesof stx1/ stx2, eae and ipaH in DEC. The dominating strain was EPEC (55.6%),followed by STEC (25%) and EIEC (19.4%).

Key words: Multiplex polymerase chain reaction (PCR), diarrheagenic Escherichia coli, shiga-like toxin.

Abbreviation

DEC, Diarrheagenic Escherichia coli; EPEC, enteropathogenicEscherichia coli; EHEC, enterohemorrhagic Escherichia coli; EIEC,eenteroinvasive Escherichia coli; ETEC, enterotoxigenic Escherichia coli; EAEC,enteroaggregative Escherichia coli; DAEC, diffusely adherent Escherichia coli; LEE,  locus of enterocyte effacement; A/E, attaching and effacing; STEC, shiga toxin–producing Escherichia coli; NCBI, National Center for Biotechnology Information; BLAST, Basic Local Alignment Search Tool; MPCR, multiplex polymerase chain reaction.