Antibiotics in animals raise concerns

The vast majority of antibiotics produced in this country are not given to humans, but to livestock being raised for food. At many of the biggest farms, animals are routinely fed antibiotics to prevent the spread of disease in crowded conditions and to promote growth.

But doctors say that practice has a dangerous side effect: it's making those same drugs less effective when humans need them for treating infections.

A recent survey by Consumer Reports and U.S. Public Interest Research Group found 85 percent of doctors have diagnosed at least one patient with a drug-resistant bacterial infection in the past year.

Antibiotic-resistant "superbugs" like Methicillin-resistant Staphylococcus aureus, commonly called MRSA, are often found in hospitals and nursing homes. The CDC reports more than two million people in the U.S. get drug-resistant infections each year, and about 23,000 die.

The spread of antibiotic-resistant bacteria is such a serious concern, the World Health Organization says it could threaten the achievements of modern medicine.

Given those worries, some smaller livestock producers, like the Rainbow Ranch Farm in Pinon Hills, California, are bucking the antibiotic trend and raising their animals drug-free.

"Here, we don't use antibiotics. We don't use medications. The animals are all free range outdoors," Xenia Stavrinides told CBS News correspondent Bigad Shaban, while taking a break from feeding the chickens.

Her farm raises about 400 animals, just a fraction of the size of some giant farms that house thousands or even tens of thousands at a time.

Antibiotics were first used by poultry producers in the 1940s, and the National Chicken Council says most of the drugs "...are never used in human medicine and therefore represent no threat of creating resistance in humans."

Rep. Louise Slaughter (D-N.Y.), the only microbiologist in Congress, has been fighting to limit the practice for more than a decade.

"I cannot get over the astonishment and anger that one of the best medical breakthroughs in the history of the world has been frittered away with such careless use," she said.

Slaughter is urging consumers to help put an end to the practice by buying only antibiotic-free meat and poultry.