Phage isolation, characterization, and antibiotic resistance profiling in Avian pathogenic Escherichia coli:...

Colibacillosis, brought on by Avian Pathogenic Escherichia coli (APEC), is a significant risk to poultry farming. The management of colibacillosis is made more difficult by the increasing levels of antimicrobial resistance (AMR) in APEC isolates. The antibiotic resistance profiles, antibiotic resistance gene (ARG) presence, and phage susceptibility of 130 APEC isolates were examined in this investigation. The highest resistance against antibiotics was detected against tetracycline and nalidixic acid, with 86.15% and 85.38%, respectively, among isolates. A high frequency of ARGs was found in the data, especially the positively correlated bla_TEM (95.38%) and tetA (85.38%) genes. The 20 bacteriophages we recovered were further described, with PhEcoAP90 having the widest host range. A 14 ± 1.41 nm tail and a 52.20 ± 2.94 nm head were revealed by TEM examination. A one-step growth experiment observed a 20-min latent period and a 58 PFU/cell burst size. PhEcoAP90 showed instability at high temperatures and extreme pH values. These results imply that although PhEcoAP90 exhibits potential as an antibiotic alternative for managing APEC infections, its use in severe settings may be restricted. To help combat AMR in chicken farming, we also suggest a unique AMR surveillance system that includes phage sensitivity, ARG prevalence, and antibiotic resistance profiles. In conclusion, our research emphasizes the need for integrated AMR surveillance systems in the poultry industry and the promise of phages as efficient alternative therapeutic approaches in regulating AMR in APEC.