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, Norfloxacin, 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.

I N the present study, indirect ELISA conducted to estimate the prevalence of MG antibodies in serum samples collected from 20 broiler flocks in Duhok governorate. Three hundred and sixty blood samples from these flocks, 126,144 and 90 serum samples were collected from broilers aged 4, 5 and 6 weeks, respectively. All samples were examined in Duhok College of veterinary medicine (Kurdistan/Iraq), from October 2021 to January 2022. The positive serum samples to MG were found in 84/126 (66.66%), 80/144 (55.55%), 32/90 (35.36%) of broilers examined at 4, 5 and 6 weeks, respectively. The overall serum positive reactors to MG were 52.48%. There was a decreasing tendency in seroprevalence with examination at 4, 5 and 6 weeks of age. Out of seven broiler flocks (A-G) examined at 4 weeks of age, three (A, B and C) show high mean ELISA MG antibodies' titer (≥5000), and only significant (P<0.05) in flock (A) (14015.3±5891.8), in comparison with all remaining five flocks (B-G). Those flocks (H-O) examined at 5 weeks of age, two flocks (H, I) show significantly (P<0.05) high mean ELISA MG antibodies' titer (≥5000) (9192.3±5944.9 and 7036±2279.3) respectively when compared with remaining six flocks (J-O). The 5 flocks (P-T) of broiler chickens examined at 6 weeks of age, only one flock (P) show significantly (P<0.05) high mean antibody ELISA MG titers (≥5000) (9357.6±6709.9). The remaining flocks (D-G), (J-O) and (Q-T) had MG antibody titers (≤5000).