Isolation and characterization of a lytic bacteriophage from wastewater source targeting Escherichia coli isolated from meat specimens

In the present study, a lytic bacteriophage specific to Escherichia coli was isolated from wastewater, and its activity against E. coli isolates obtained from raw meat was investigated. A total of 60 raw meat swab samples were collected from butcher shops in Zanjan Province, Iran. The presence of β-lactamase genes, including bla TEM, bla SHV, and blaCTX-M, was examined using multiplex PCR. Bacteriophage isolation was performed using E. coli ATCC 25,922 as the host strain. Of the 60 samples, 37 (61.7%) were positive for E. coli . The highest resistance rates were observed against tetracycline (59.5%), trimethoprim–sulfamethoxazole (57.0%), and amoxicillin (57.0%). Among the resistance genes, blaTEM was the most frequently detected (27.0%), followed by bla CTX-M and bla SHV. The isolated bacteriophage had an icosahedral head and a short, non-contractile tail. The phage remained active at temperatures ranging from − 20 °C to 55 °C but was completely inactivated at 65 °C. The detection of β-lactamase genes and antibiotic resistance among E. coli isolates from raw meat indicates a potential public health risk. he isolated bacteriophage exhibited lytic activity against 54.1% of the E. coli isolates, indicating its preliminary potential as a biocontrol agent against antibiotic-resistant E. coli in meat products. However, further studies, including evaluations in food matrices, are required to assess its practical applicability.