Identification of Antibiotic Resistance Pattern, and Detection of Virulence Genes iss, and ompT in Avian Pathogenic Escherichia coli from Broiler Chickens in Chitwan, Nepal

This study aimed to identify, evaluate the antibiotic resistance pattern and detect virulence genes iss, and ompT in avian pathogenic Escherichia coli (APEC) from broiler chickens in central Nepal. To determine the antibiotic resistance pattern of the obtained isolates, the Kirby-Bauer disc diffusion method was used with six different commercial antibiotic discs: Amikacin, Gentamycin, Ciprofloxacin, Doxycycline, Chloramphenicol and Levofloxacin. A polymerase chain reaction (PCR) assay was used for the selected isolates (n=40) to screen the presence of the iss and ompT genes after the extraction of DNA using the boiling method Out of 60 suspected Colibacillosis liver samples, 40 were confirmed as E. coli positive The antibiogram profile revealed maximum resistance to Doxycycline (87.5%), followed by Levofloxacin (72.5%), Ciprofloxacin (67.5%), Chloramphenicol (40.0%), Gentamycin (32.5%) and Amikacin (10.0%).. The presence of the iss and ompT genes was found to be 100.0% and 90.0%, respectively. APEC was found to be highly resistant to most of the antibiotics. Virulence-associated genes iss and ompT were obtained at high percentages from Colibacillosis suspected broiler chickens in Chitwan, Nepal. These finding suggests that the judicial use of antimicrobials is compulsory to check antibiotic resistance and Colibacillosis outbreaks in poultry farms.