Farm- or backyard-raised chickens like these Dominiques avoid the contamination found in factory farms. (Photo: Bryan K. Oliver)

RODALE NEWS, EMMAUS, PA—Chicken is chicken, right? Well, not exactly. More and more research is finding that chickens raised in industrial settings are more likely to be contaminated with harmful bacteria when you buy their meat at the store. A new Consumer Reports analysis found that two-thirds of the store-bought birds they tested were either contaminated with salmonella or campylobacter—or both. Those pathogens are the top bacterial culprits behind foodborne illnesses.

THE DETAILS: Consumer Reports bought a total of 382 fresh, whole broilers from more than 100 supermarkets, gourmet and natural food stores, and mass merchandisers in 22 states, and sent them to an outside lab for bacterial analysis. Researchers found campylobacter in 62 percent of the chickens, salmonella in 14 percent, and both types of bacteria in 9 percent of the chickens tested. Just 34 percent of the birds were clear of both germs. Even more alarming, most of the chickens that tested positive for harmful bacteria contained at least one germ that showed resistance to one or more antibiotics, which makes infections harder to treat. The number of antibiotic-resistant strains Consumer Reports has detected in chickens is up more than 30 percent since 2007.

Tyson and Foster Farms brand chickens had the worst records, with less than 20 percent free of either pathogen. Perdue was the cleanest of the brand-name chickens, with 56 percent free of both germs. Sixty percent of "air-chilled" broilers, ones that are refrigerated promptly after processing and sometimes misted with chlorinated water rather than dunked in cold chlorinated water, were free of the harmful bacteria. None of the store-brand organic chickens tested positive for salmonella, although only about half were also free of campylobacter.

"Consumers still need to be very careful in handling chicken, which is routinely contaminated with disease-causing bacteria," said Dr. Urvashi Rangan, director of technical policy at Consumers Union, the nonprofit publisher of Consumer Reports. "Our tests show that campylobacter is widespread in chicken, even in brands that control for salmonella. While one name brand, Perdue, and most air-chilled chickens, were less contaminated than others, this is still a very dirty industry that needs better practices and tighter government oversight."