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

Pak Vet J

Publisher

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

Publisher Country

Pakistan

Indexing

Thomson Reuters

Impact Factor

5.4

Publication Type

Prtinted only

Volume

46

Year

2026

Pages

1-9