Thesis (Ph.D.) - Cairo University - Faculty of Veterinary Medicine - Department of Microbiology

Poultry is the most important economic face for Egypt industry. Colibacillosis consider a dangerous problem for poultry industry. Quaternary ammonium compounds (QACs) are widely distributed in poultry industry. Occurrence of qac and antibiotic resistant genes in E.coli isolated from chickens in Egypt were detected in the study. The incidence of E.coliin chicken was 34%. E.coliisolated were serologically identified commonly serogroups were O128, O111, O44, O158 and O2. Antibiogram pattern of E.colirevealed that 100% of isolates were resistant to ampicillin, erythromycin and sulfamethoxazole-trimethoprim, while were sensitive for colistin sulphate and levofloxacin with 73.53% and 38.23%respectively. Antibiotic resistance genes as tetA gene was tested for isolated E.coliand detected by incidence rate 91.18%. qac resistance genes resembling as qacED1 and qacA/B genes were detected in isolated E.coli 70.6% and 14.7% respectively, while qacC/D gene wasn{u2019}t detected in all E.coli isolates by PCR. In conclusion, E.coli isolated from chickens in Egypt was carried bothqac and antibiotic resistant genes that affect poultry industry

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