Ferdowsi University of Mashhad

Document Type : Research Articles


1 Ferdowsi University of Mashhad

2 فردوسی مشهد

3 دانشگاه فردوسی مشهد

4 Division of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran



Escherichia coli is reported as the most common organism in humams and animals and introduced as a critical priority bacterium due to antibiotic resistance according to World Health Organization. The multi drug resistant (MDR) and Extended-Spectrum β-Lactamase (ESBL)-Producing E. coli stains have become a global health challenge worldwide since the related infections are difficult to treat. Poultry has been considered as an important reservoir of E. coli, can play an important role in transmitting these strains to humans. The objective of this study was to determine the prevalence of ESBL-producing and MDR E. coli isolated from poultry and their association with different phylogroups. The current study was conducted on a collection of 100 E. coli isolates from colibacillosis in poultry. Antimicrobial susceptibility testing, ESBL production, the prevalence of ESBL-mediated genes (blaTEM, blaSHV, blaOXA, and blaCTX-M) were assessed and phylogenetic groups were analyzed using the Clermont 2013 and 2019 updated methods. The highest resistance was against tetracycline (88%), trimethoprim/sulfamethoxazole (86%), and chloramphenicol (70%). Also, the frequency of ESBL-production and MDR was (41%) and (70%), respectively. The blaTEM was the most prevalent gene among isolates with a frequency of 48%. Phylogroup analysis assigned E. coli isolates to B1 (23%), D (22%), A (10%), G (11%), F (8%), B2 (5%), and C (4%). Applying antimicrobial stewardship is critical because the circulation of ESBL-producing E. coli and MDR isolates threatens medicine and veterinary. In addition, our results revealed the noticeable prevalence of the novel phylogroup G in poultry for the first time in Iran.