Dominant EAEC and Widespread Antibiotic Resistance among Diarrheagenic Escherichia coli in Children with Acute Diarrhea in Zahedan, Iran

Introduction: Diarrheal disease is a major cause of morbidity and mortality among children under the age of ۱۰ worldwide, particularly in low- and middle-income countries. Diarrheagenic Escherichia coli (DEC) is a common cause of gastroenteritis in children. This study investigated the frequency, virulence markers, and antibiotic resistance patterns of DEC in children below ۱۰ years with acute diarrhea in Zahedan, Iran. Methods: In this cross-sectional study, ۳۰۰ E. coli isolates were collected from stool samples of children aged below ۱۰ years with diarrhea who presented to hospitals and clinical laboratories in Zahedan. DEC pathotypes were identified using multiplex PCR and confirmed by standard biochemical tests and polyvalent antisera. Results: Of the ۳۰۰ E. coli isolates examined, ۸۹ (۲۹.۶%) were identified as diarrheagenic E. coli (DEC) using polyvalent antisera targeting known DEC pathotypes. Enteroaggregative E. coli (EAEC) was identified in ۳۱ isolates (۳۴.۸۳%) based on reaction with antiserum No. ۱. Enterotoxigenic E. coli (ETEC) was identified in ۳۵ isolates (۳۹.۳۳%) based on reaction with antiserum No. ۲. Enteropathogenic E. coli (EPEC) was identified in ۲۳ isolates (۲۵.۸۴%) based on reaction with antiserum No. ۳ (anti-coli۳). Multiplex PCR identified the most common pathotype as EAEC (۳۷.۶%), followed by EPEC (۲۱.۷%), ETEC (۱۵.۹%), and EIEC (۱۱.۵%). Statistical analysis revealed no significant correlation between the presence of specific virulence genes (e.g., eae, pcvd۴۳۲, elt, est, and iaH) and antibiotic resistance patterns in the DEC isolates. Conclusion: Given the distribution of DEC pathotypes among children in Zahedan and their increased antibiotic resistance, antibiotic treatment should be guided by molecular typing and antimicrobial susceptibility testing of isolates, when appropriate.

کلیدواژه ها:

Diarrheagenic E. coli (DEC) ، Antibiotic resistance ، Enteroaggregative E. coli (EAEC) ، Children ، Zahedan ، Multiplex PCR