Avian pathogenic Escherichia coli (APEC) are causative agents of extraintestinal infections, collectively known as colibacillosis, which results in significant economic losses in poultry industries. Colibacillosis is the most frequent bacterial disease in avian species and antimicrobials are the main weapon to reduce incidence and mortality associated with it.
However, inappropriate use of antibiotics may lead to therapy failure. This study was conducted to isolate APEC and to investigate the antibiotic resistance profiles of the isolates for further development of different control strategies. A total of 138 samples (liver, heart blood and lung) were collected from different broiler chicken farms in Giza, Sharqia and Qalyubiyya Governorates. All samples were subjected to bacteriological examination for isolation and identification of E. coli. Confirmed that E. coli strains were subjected to antimicrobial susceptibility test. The results revealed that 114 out of 138 samples (82.6%) were positive for E. coli isolation. Concerning antibiotic sensitivity test, high resistance was detected against ampicillin, tetracycline and nalidixic acid. Meanwhile E. coli isolates showed less resistance to ciprofloxacin and erythromycin. Overall, all - isolates showed resistance to at least three or more antimicrobials. These findings suggest the need for surveillance and intervention system to control misuse of antibiotics and APEC outbreak in- poultry farms.