Investigation of Prevalence, Phylogenetic Groups and Antibiotic Resistance Patterns of Enteroaggregative Escherichia coli(EAEC)Isolated from Diarrheic children in Mashhad

Purpose of this study was to investigate of prevalence, phylogenetic groups and antibiotic resistance pattern EAEC isolated from diarrheic children in Mashhad city.

This cross-sectional study conducted for one year. In total, 450 diarrhea samples of children under 10 years of age were collected from children's specialized hospital in Mashhad. After isolation of Escherichia coli, EAEC isolates were identified by PCR molcular method. Phylogenetic groups of EAEC isolates were determined using the original and updated 2019 method. Antimicrobial susceptibility test was performed using disc diffusion methods(Kirby-Bauer method) against 12 antibiotics.

44(9.8%) EAEC isolates were identified from 422(93.8%) Escherichia coli isolates by PCR. Seven phylogroups including D(40.9%), unknown(27.3%), G(11.4%), B1(9.1%), F(4.5%), B2(4.5%) and A(2.3%) were detected among EAEC isolates.The highest diversity of antibiotic resistance patterns was related to Phylogroup D. EAEC isolates showed the highest resistance to amoxicillin and erythromycin 100%. Overall, 97.7% of EAEC isolates were with multiple drug resistance(MDR).

The present study showed a significant presence of EAEC strains. Considering the role of EAEC in chronic diarrhea and growth retardation syndrome in children, it is suggested that the identification of EAEC strains to be considered in diagnostic laboratories in cases of children’s diarrhea. on the other hand, due to the high prevalence of multiple resistances, antibiogram test is required to treat diarrhea in children.