Multidrug Resistance Profile of Avian Escherichia coli Isolated from Day-Old Broiler Chickens in West Azerbaijan Province (۲۰۲۲–۲۰۲۵)

Background: Drug resistance represents a major challenge in microbial disease treatments like Umbilical sepsis and colibacillosis disorders, being a result of E.coli serovars infections as a main zoonotic pathogen, especially in the Poultry farming industry. Methods: ۷۱۲ samples obtained by the laboratory from West Azerbaijan Provenance from ۲۰۲۲ to ۲۰۲۵. Identification and characterization of E.coli serovars from yolk sac and hepatic tissue of Day-Old broiler chickens through physiological, biochemical tests, and methods described in the Bacteriological Analytical Manual of the Food and Drug Administration were done. The antibiotic sensitivity was estimated with API identification kits and certified by the Kirby-Bauer disc diffusion susceptibility test to a panel of ۱۸ different antibiotics. Results: Erythromycin (۹۸%), Oxytetracycline and Difloxacin (۹۶%), Flumequine (۸۶%) and Lincomycin-spectinomycin (۶۱%) were resistant and Fosfomycin (۶۴%), Colistin (۵۳%), Danofloxacin (۴۹%), Enrofloxacin (۴۲%), Florfenicol, Neomycin and Tilmicosin(۴۰%), Soltrim (۳۹%), Norfloxacin (۳۷%), Gentamicin (۳۰%), Thiamphenicol (۲۴%) and Doxycycline(۱۷%) were sensitive to E.coli. Conclusion: As indicated by the data, Erythromycin, Oxytetracycline, and Difloxacin, with significant Coefficient of Variation and slight Standard Deviation, exhibited variable and unpredictable performance. With a low CV and high Mean, Colistin - Fosfomycin - Norfloxacin - Danofloxacin demonstrates stable and reliable antimicrobial performance. Oxytetracycline and Tilmicosin showed limited efficacy against E.coli due to their antimicrobial action. The observed resistance of E.coli to Oxytetracycline and Gentamicin is likely the result of prescription-free use of these drugs. These findings highlight the urgent need for antibiotic stewardship and surveillance programs in poultry farms.

کلیدواژه ها:

Zoonotic ، Antibiotic Resistance ، Broiler Chickens ، Escherichia coli ، West Azerbaijan