The Prevalence of Typical and Atypical Enteropathogenic <i>Escherichia coli</i> Strains Isolated from Non-diarrheal Stool Samples of Children of Tehran

Background: Diarrheagenic Escherichia coli (DEC) strains cause a self-limited gastrointestinal disease in developing countries and often infect children. Enteropathogenic E. coli (EPEC) is the most common DEC strain, which is usually carried by diarrheal children. However, some non-diarrheal EPEC carriers, particularly atypical enteropathogenic E. coli (aEPEC), have been increasing in some countries, including Iran. Objectives: Our aim was to evaluate the prevalence of typical EPEC and atypical EPEC strains and their antimicrobial resistance rate among non-diarrheal children under 10 years of age, isolated from schools and welfare centers in Tehran. Methods: We collected 350 fecal specimens from non-diarrheal children. The strains were analyzed for the presence of virulence genes such as eae, bfpA, stx-1, and stx-2 genes. Antibiotic resistance rates of the strains were examined using the disk diffusion method. Results: Among 350 fecal specimens, 160 specimens were taken from boys and 190 specimens from girls. The results of the genotypical-based assay for eae, bfpA, stx-1, and stx-2 genes showed 32% of isolates were eae positive. Overall, of 142 isolates, 1.4% were only bfpA positive and 7.04% and 1.7% contained stx-1 and stx-2, respectively. Resistance rate to tigecycline among EPEC strains was more reported than other antibiotics. On the other hand, 13.43% of isolates were considered Fosfomycin-susceptible EPEC strains. Conclusions: The results showed the prevalence of atypical enteropathogenic E. coli strains is increasing in schools, and so there is a dangerous alarm as these carriers spread the antimicrobial-resistant strains in the community and can shift the microbial flora pattern.