Rampant use of antibiotics in animal agriculture means foodborne illnesses are likely to become longer, more serious, and harder to treat, according to the nonprofit Center for Science in the Public Interest.

In three major outbreaks of antibiotic-resistant foodborne illness in 2011, 167 Americans became sick, 47 were hospitalized, and one died, according to a white paper released by the group today. Two of those outbreaks were connected to ground turkey, one contaminated with Salmonella Hadar and one with Salmonella Heidelberg, and one outbreak was connected to ground beef contaminated with Salmonella Typhimurium. All of those bacteria were resistant to treatment from several antibiotics that are critically important to human medicine, including drugs in the penicillin, cephalosporin, and tetracycline families.

"Antibiotics are the crown jewels of modern medicine, and they are critical to treating diseases in both humans and farm animals," said CSPI food safety director Caroline Smith DeWaal. "We must not continue to jeopardize the effectiveness of these drugs by using them recklessly for non-therapeutic uses on farms and in animal factories. Otherwise, consumers may face longer illnesses, more hospitalizations, and more fatalities when exposed to resistant strains of common foodborne pathogens."

Antibiotic resistance is an inevitable consequence of antibiotic use, according to the CSPI report. The more antibiotics are used, the more bacteria will develop resistance—often to more than one drug at a time. Pigs, chickens, and cattle are often administered antibiotics in their feed or water, to promote growth or to prevent diseases caused by overcrowding and unsanitary conditions, according to CSPI. Exacerbating the problem is that farmers in the U.S. can obtain and administer antibiotics without prescriptions or veterinary oversight.

The drug industry produced more than 29 million pounds of antimicrobial drugs approved for use in food animals, according to the Food and Drug Administration. CSPI says that food animals consume 80 percent of all antibiotics used in the United States and that 65 percent of those antibiotics are similar or identical to those used in human medicine.

CSPI’s review of antibiotic-resistant foodborne illness outbreaks shows that outbreaks were most common in dairy products, with 12 such outbreaks since 1973, and ground beef, with 10 outbreaks. Four outbreaks were linked to poultry, with ground turkey appearing for the first time as a source of antibiotic-resistant bacteria with the two 2011 outbreaks linked to Jennie-O and Cargill products.

CSPI presented its findings at a series of briefings for House and Senate staff in Washington along with several leading infectious-disease physicians and health experts, including Drs. Jim R. Johnson of the University of the Minnesota School of Medicine, Stuart Levy of Tufts University School of Medicine and the Alliance for the Prudent Use of Antibiotics, Lance Price of the TGen Center for Food Microbiology and Environmental Health, and Tara Smith of the University of Iowa College of Public Health.