Detection of diarrheagenic strains of E. coli from pediatric diarrheal infection in a tertiary hospital, Bangladesh

Abstract

Background: Diarrhea continues to be one of the most common causes of morbidity and mortality among infants and children in Bangladesh and E. coli is an important agent of childhood diarrhea. Objectives: To determine the prevalence of diarrheagenic Escherichia coli (DEC) and its pathotypes in pediatric population with diarrheal infection using polymerase chain reaction (PCR). Methods: This was a descriptive type of cross-sectional study conducted among the pediatric population with diarrhea admitted in Rajshahi Medical College hospital, Rajshahi, Bangladesh from July 2014 to June 2015. In this study, 268 children with diarrheal infection aged from 3 to 12 years were included. Stool samples were collected and identified as E. coli isolates by culture on MacConkey’s agar media, microscopy and standard biochemical tests. Diarrheagenic strains of E. coli (DEC) were identified by multiplex PCR assays using six primer pairs by detecting the genes of enterotoxigenic E. coli (lt, st), Enteropathogenic E.coli (eae, bfp), Enteroaggregative E.coli (aat) and Enteroinvasive E.coli (iPah). Results: Among 268 stool samples, 166 E. coli were isolated. Of the total 166 isolated E. coli, 68(38%) were DEC identified by multiplex PCR. Among DEC, most frequently isolated pathotypes was EPEC (38, 44.7%), followed by ETEC (26, 30.5%), EAggEC (20, 23.5%) and EIEC (1, 1.1%). Conclusion: This study shows that DEC is an important pathogen causing diarrhea in pediatric group but yet there is no data available of strains responsible in the study area. Strain identification is essential for E. coli diarrhea and by using multiplex PCR assay, the simultaneous detection of strains in one PCR reaction can be done that makes a conclusive diagnosis of diarrhea.