Phylogenetic Analysis of Attaching and Effacing E. coli Strains Isolated From Pet Birds in Iran

Background: Enteropathogenic E. coli (EPEC) and Shiga toxin-producing E. coli (STEC) are categorized as attaching and effacing E. coli (AEEC) due to their eae gene. One of the essential causes of diarrhea in humans is AEEC, which affects birds, too, thereby being considered a zoonotic pathogen.Objectives: Our study aimed to determine AEEC and evaluate its antibiotic resistance and phylogroups. Methods: A total of ۲۰۰ fecal samples were collected from pet birds referred to the Veterinary Medicine Hospital, University of Tehran. PCR methods were used to detect AEEC using uspA, eae, bfpA, stx۱, and stx۲ gene-specific primers. The antimicrobial susceptibility of the recovered isolates was determined by the agar disk diffusion and MIC methods. Their phylogroups were analyzed based on Clermont phylotyping methods.Results: Of ۲۰۰ samples, we isolated ۲۶ (۱۳%) E. coli strains, ۹ harbor eae genes. None of the ease-positive samples possessed the bfpA gene, but ۴ had stx۲, and ۵ had stx۱ and stx۲ genes. Phylogenetic analysis identified the phylogenetic groups of all AEEC isolated strains but ۲ (duck and cockatiel). Detected phylogroups include four B۲ and three D. Based on our results, ۷ out of ۹ AEEC isolated strains showed multi-drug resistance.Conclusion: The discovery of common phylogroups of AEEC in pet birds (a common companion animal in Iran with intimate contact with their owners, especially children) and humans, as well as their resistance to a wide range of antibiotics used in human medicine, verifies AEEC as a serious public health threat.

Keywords:

Attaching and effacing E. coli (AEEC) , Escherichia coli (E. coli) , Phylogrouping , Shiga toxin , Shiga toxin-producing E. coli (STEC)