Antibiotic-resistant bacteria not found in free-range chickens

One of the problems with raising large numbers of animals in confinement is that disease is more common, resulting in a greater reliance on antibiotics. Over time, the bacteria mutate and become resistant to the drugs. When we humans become infected with these antibiotic-resistant bacteria, there are fewer effective medications available to treat us.

A survey of E. coli bacteria isolated from poultry raised in a state-of-the-art confinement poultry operation at a university found that all the bacteria were resistant to the commonly used antibiotics, Tetracycline, Streptomycin and Sulphonamide (Sulphafurazole). By contrast, all the strains of bacteria isolated from free-range birds were sensitive to the drugs.

Ojeniyi, A. A. (1989). "Public health aspects of bacterial drug resistance in modern battery and town/village poultry" Acta Vet Scand 30(2): 127-32.