Antibiotic Resistance Patterns of Escherichia coli Isolated From Broiler Chickens with Colibacillosis in Duhok Province

T HE study was aimed to describe the Prevalence, bacteriological and antimicrobial resistance of Escherichia coli isolated from broilers flocks in Duhok province during the period from October 2021 tell January 2022. Fifty commercial broiler flocks at 14 different regions of Duhok province were included. Bacteriological swab samples were collected from broilers aged 2 to 6 weeks showing clinical signs and necropsy findings of suspected colibacillosis Two hundred and fifty pericardial swab samples were taken from necropsied live and recently died chickes. Standard bacteriological methods represented by culturing on MacConkey and EMB agar followed by biochemical tests were performed to detect Escherichia coli . Qualitative disc spread method was used to assay antibiotic sensitivity to 19 type of antibiotics. The results showd that out of 250 samples, 162 (64.8% ) were positive to E.coli isolation. Antibiotic sensitivity test of 50 E.coli isolates showed high resistance (>50%) to Neomycin, Lincomycin, Azithromycin, Cephalexin, sulphamethaxazole-Trimethoprim, Spiramycin, Florfenicol, Nor -floxacin, Doxycycline, Enrofloxacin, Phosphomycin, rythromycin, Tetracycline, Tylosin and Amoxicillin, while a moderate resistance (20-50%) was observed with Colistin, Ciprofloxacin, Levofloxacin, and Gentamycin. Twelve resistance patterns (MDR) were recorded with E coli isolates. Measures must be taken to avoid the development of resistance to E coli in chicken farms through appling antibiotics sensitivity test before drug adminestration coupled with biosecurity and good hygienic practise.