Prevalence of Escherichia coli Pathotypes Among Children With Diarrhea in Babol, Northern Iran

Fatemah Moshtagian,Majid Alipour,Yousef Yahyapour

doi:10.15171/ijep.2016.01

Abstract

Background: Diarrheagenic Escherichia coli (DEC) are major causes of diarrhea in the world particularly among infants and young children. Objectives: The aim of this study was to determine the prevalence of DEC strains in stool samples from children under 5 years old. Patients and Methods: Stool specimens were collected from 200 children under 5 years visiting hospital due to gastroenteritis. E. coli pathotypes were detected by using conventional culture techniques and polymerase chain reaction (PCR). Results: Sixty-eight (34%) out of 200 specimens were positive for DEC. Different pathotypes would show the following profiles: 43 (21.5%) for enteropathogenic E. coli (EPEC); 18 (9%) for enterotoxigenic E. coli (ETEC) including 10 (55.5%) st positive, 6 (33.3%) lt positive and 2 (11.1%) st and lt both positive; 6 (3%) for enteroaggregative E. coli (EAEC) and 1 (0.5%) for enteroinvasive E. coli (EIEC). Enterohemorrhagic E. coli (EHEC) was not isolated from any of the E. coli strains tested. Conclusions: This study shows that DEC is a common cause of childhood diarrhea in Babol. EPEC and ETEC were the most frequent pathotypes in the population under study.

Highlights

Diarrheagenic Escherichia coli (DEC) are major causes of diarrhea in the world among infants and young children
Diarrheagenic Escherichia coli (DEC) are conveniently classified into 6 major pathotypes according to their virulence genes and including enterotoxigenic E. coli (ETEC), Shiga toxin producing E. coli (STEC, referred to as verotoxigenic E. coli (VTEC) or enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC), and diffusely adherent E. coli (DAEC).[2]
Of the 68 DEC strains detected by polymerase chain reaction (PCR), 43 (21.5%) were EPEC, 18 (9%) ETEC, 6 (3%) EAEC and 1 (0.5%) EIEC isolates

Summary

Introduction

Diarrheagenic Escherichia coli (DEC) are major causes of diarrhea in the world among infants and young children. There are small groups of E. coli that have evolved and developed pathogenic strategies that can cause a broad spectrum of disease, including severe diarrheal disease.[1] Diarrheagenic Escherichia coli (DEC) are conveniently classified into 6 major pathotypes according to their virulence genes and including enterotoxigenic E. coli (ETEC), Shiga toxin producing E. coli (STEC, referred to as verotoxigenic E. coli (VTEC) or enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC), and diffusely adherent E. coli (DAEC).[2] EIEC is the only E. coli pathotype to invade and multiply within host epithelial cells, and can cause invasive inflammatory colitis and dysentery, but most symptomatic infections are characterized by watery diarrhea indistinguishable from that produced by other diarrheagenic E. coli pathotypes.[3] EHEC cause hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS).[4] ETEC is an important cause of diarrheal disease in infants (6-18 months), young children, and the elderly in the developing world. Several polymerase chain reaction (PCR) tests have been developed to amplify the target regions present in virulence genes and identify strains of DEC.[12]

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Conclusion