This study evaluates the occurrence of bacteriophages carrying antibiotic resistance genes in animal environments. bla(TEM), bla(CTX-M) (clusters 1 and 9), and mecA were quantified by quantitative PCR in 71 phage DNA samples from pigs, poultry, and cattle fecal wastes. Densities of 3 to 4 log(10) gene copies (GC) of bla(TEM), 2 to 3 log(10) GC of bla(CTX-M), and 1 to 3 log(10) GC of mecA per milliliter or gram of sample were detected, suggesting that bacteriophages can be environmental vectors for the horizontal transfer of antibiotic resistance genes.
Colomer-Lluch, M., Imamovic, L., Jofre, J., & Muniesa, M. (2011). Bacteriophages Carrying Antibiotic Resistance Genes in Fecal Waste from Cattle, Pigs, and Poultry. Antimicrobial Agents and Chemotherapy, 55(10), 4908-4911. https://doi.org/10.1128/AAC.00535-11