الفهرس 
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Abstract
Colibacillosis is an important syndromes affecting broilers, and Avian pathogenic Escherichia coli is the main culprit. This study aimed to isolate, identify, and assess APEC from diseased broiler chickens, assessing their virulence-associated genes (VAGs) and antimicrobial susceptibility profile. E. coli bacteria were isolated from 115 colibacilosis-dubious broilers and PCR was used to investigate the presence of eleven virulence-associated genes. In addition, E.coli isolates were tested against ten antimicrobial agents including, ampicillin, amoxicillin, doxycycline, colistin, imipenem, clindamycin, ciprofloxacin, cefuroxime, amikacin and chloramphenicol by the ”Kirby-Bauer disc diffusion” technique. The detection rate of E.coli was 38.26 (44 / 115). The frequency of omp T, hly, iuc, irp, astA, iorN, iutA, cva/cvi, tsh, iss, papC was 88.60, % 97.70%, 86.40%, 81.80%, 95.50%, 93.20%, 84.10%, 15.90%, 27.30%, 88.60% and 34.10% respectively. Among E.coli isolates (n=44), 42 isolates (95.45%) carried five or more virulence genes and 41 isolates carry 3 or more APEC virulence genes (hlyA, iut, omp, iss, iorN). All retrieved APEC isolates showed multidrug resistance (MDR) phenotypes. Multidrug-resistant APEC was detected to ampicillin, amoxicillin, cefuroxime, clindamycin and doxycycline, while E. coli isolates were resistant to colistin, imipenem, ciprofloxacin and amikacin. This work identified the antimicrobial resistance patterns of avian pathogenic E. coli VAGs, highlighting the need to monitor the spread of ARGs in chicken farms.