Extra-intestinal pathogenic E. coli (ExPEC) is a causative agent of colibacillosis in poultry, leading to significant economic losses worldwide. This study aimed to evaluate the antimicrobial resistance profile of 325 isolates recovered from deceased broiler chickens with clinical cases of colibacillosis, on different farms in the northern area of the Palestinian territories. Antibiotic susceptibility testing was conducted using the Kirby-Bauer disc diffusion method with 17 commonly used antibiotics. All tested ExPEC isolates showed multidrug resistance (MDR). The highest levels of resistance were seen against amoxicillin (100%), ceftiofur (99.4%), enrofloxacin (99.1%), ceftriaxone (95.4%), levofloxacin (94.2%), gentamicin (92%), norfloxacin (90.5%), and florfenicol (90.2%). Additionally, high resistance levels were observed against ciprofloxacin (84.9%), sulfamethoxazole/trimethoprim (80%), and cephalexin (67.5%). Intermediate resistance was noted for neomycin (45.3%), doxycycline (43.1%), and fosfomycin (40.3%), while low resistance was found for polymyxin B (22.1%), spectinomycin (26.8%), and colistin (10.5%). According to the Multiple Antibiotic Resistance Index (MARI), Palestinian ExPEC isolates are considered high-risk due to their exposure to a high level of antibiotics. Statistical analysis revealed significant differences between various farms. The indiscriminate and excessive use of antibiotics can lead to the emergence of drug-resistant bacterial strains. Alternative methods such as immunization have become more popular to manage ExPEC without relying solely on antibiotics. Understanding antibiotic resistance in ExPEC is crucial for developing effective treatment and control strategies. A comprehensive approach is necessary to prevent and manage avian colibacillosis in Palestine.

Title

Pakistan Veterinary Journal.

Publisher

the Faculty of Veterinary Science, University of Agriculture, Faisalabad, Pakistan.

Publisher Country

Pakistan

Indexing

Thomson Reuters

Impact Factor

6.5

Publication Type

Both (Printed and Online)

Volume

46

Year

2026

Pages

373-381