Antibiotic use in poultry processing has been controversial for decades, but researchers now say workers who handle broiler chickens in manufacturing plants are at risk of contracting drug-resistant E. coli and spreading it to local communities.

A broiler is a male or female chicken bred and slaughtered for its meat.

Massive demand for chicken has led to factory farming, which cramps many thousands of birds together in a single environment.

The use of growth enhancers, such as hormones and antibiotics, have helped create bigger broilers that are more appealing to consumers.

So-called free-range chickens are raised on organic farms and are not exposed to antibiotics or hormones.