Antibiotic Resistant Bacteria Found in U.S. Poultry

By J.R. Pegg

WASHINGTON, DC, December 10, 2002 (ENS) - Three times more antibiotics by weight are fed to poultry in the United States than humans consume, and the poultry industry's use of antibiotics is a health risk to American turkey and chicken eaters, according to two independent studies released today.

The studies, one from Consumer Reports and another jointly produced by the Sierra Club and the Institute for Agriculture and Trade Policy (IATP), raise concerns that Americans are increasingly likely to purchase chicken contaminated with strains of salmonella or campylobacter bacteria that are resistant to one or more antibiotics often used to treat people.


Poultry house (Photo by Rob Flynn courtesy ARS)
"It is no small problem that bacteria on meat are getting more and more resistant to antibiotics," said Dr. David Wallinga, an IATP scientist and co-author of the Sierra Club/ITAP study.

"Common, brand name poultry products routinely carry at least one disease causing germ if not more, and these bacteria are often resistant to one or more antibiotics. The resistance we found is for many of the same medicines that doctors rely on for treating people sick with infections," Dr. Wallinga said.

Salmonella and campylobacter bacteria can cause fever, diarrhea and abdominal cramps. People who are infected with antibiotic resistant bacteria are likely to be subjected to lengthier, more serious illnesses.

Poultry industry representatives called the studies "unduly alarming to consumers" and countered that antibiotic resistance is more likely the result of over prescription by doctors.

In addition, U.S poultry has less bacteria now than ever before, according to industry sources.

"The potential risk of antibiotic resistant pathogens transferring from animals to humans via the food supply is growing smaller all the time," according to a joint statement from several poultry industry groups.


Microscopic fluorescent green Campylobacter cells on chicken skin. (Photo by Anna Bates courtesy USDA Agricultural Research Service)
No one argues that salmonella and campylobacter bacteria pose a health risk to consumers. The Centers for Disease Control and Prevention (CDC) estimates that together they account for some 3.3 million food borne infections and more than 650 deaths each year.

Some 1.1 million Americans, according to the CDC, are sickened each year by undercooked chicken that harbor bacteria or by food that raw chicken juices have touched.

Poultry producers are doing everything they can to produce healthy animals, and concern over antibiotic resistant bacteria are overblown, according to Richard Lobb, spokesman for the National Chicken Council.

"There is always going to be some risk of unwanted bacteria, whether it is chicken, beef or cantaloupes," Lobb said. "There is one thing you can do to eliminate that risk and that is to prepare and cook food properly."

The groups who reported the studies both called for increased consumer vigilance in the handling and preparation of chicken. Still, they believe the industry could do more to reduce the use of antibiotics in raising poultry, especially antibiotics that are also used to treat humans.

The Union of Concerned Scientists (UCS) estimates some 10.5 million pounds of antibiotics are fed to American poultry each year, with some 21 percent virtually identical to the ones doctors use to treat sick people. These include tetracyclines, erythromycin, penicillin, bacitracin and virginiamycin.

By contrast, UCS estimates all human antibiotic use is some three million pounds per year.

These two studies are some of the first to examine the presence of antibiotic resistant bacteria in chicken. Consumer Reports investigators found nearly half the 484 chickens they tested had either salmonella or campylobacter bacteria.

Some 90 percent of the campylobacter bacteria and 34 percent of the salmonella bacteria showed some resistance to one or more antibiotics often used to treat people.

"The bacteria counts from our 1998 report to this have gone down," said David Pittle, senior vice president of technology for Consumers Union, which publishes Consumer Reports. "But this is the first data point measuring the resistance to antibiotics, and it is a very uncomfortable starting point."

"You need swallow just 15 to 20 salmonella bacteria or about 500 campylobacter bacteria to become ill," said Doug Podolsky, senior editor of Consumer Reports.

The 484 whole broiler chickens used in the Consumer Reports study were purchased in 25 cities across the United States.

Tests conducted by the Institute for Agriculture and Trade Policy (IATP) and Sierra Club found 95 percent of the 200 chickens tested had campylobacter bacteria, with 62 percent of the campylobacter resistant to one or more antibiotics.

The IATP/Sierra Club study was conducted on 200 fresh whole chickens and 200 packages of ground turkey purchased from grocery stores in Des Moines, Iowa and Minneapolis/St.Paul, Minnesota. Salmonella bacteria were found in 18 percent of the whole chickens and 45 percent of the ground turkey samples. Of the salmonella bacteria found in ground turkey, 62 percent were resistant to one or more antibiotics.

Campylobacter bacteria were found in only two percent of the ground turkey. Both campylobacter and salmonella bacteria were found in 23 percent of the chickens sampled.

The subtherapeutic use of antibiotics, which is the use for purposes other than treating disease, is a primary concern found by both studies. Antibiotics are given to poultry to quicken growth and are also administered as preventive measures to fight possible infection.


Turkeys (Photo by Scott Bauer courtesy ARS)
This use is most prevalent on factory farms that have come to dominate the U.S. poultry industry. The U.S. Environmental Protection Agency (EPA) defines factory broiler poultry farms as those that contain at least 100,000 broiler chickens or 55,000 turkeys. These factory farms account for some 97 percent of U.S. sales of boiler chickens.

"This sets the stage for the evolution of drug resistant microbes that multiply around chicken coops," Podolsky said. "Bacteria that survive drug treatment may eventually contaminate carcasses during slaughtering and processing. If chicken isn't cooked thoroughly enough, they could end up on your dinner plate and colonize your intestines."

Consumers Union has called on the USDA to extend its food safety program to test for campylobacter and has also suggested the ban of subtherapeutic uses of medically important drugs in poultry and other livestock, but the industry is not convinced this is such a good idea.

"Banning the use of antibiotics for prevention and control, and to improve intestinal health, is counterproductive to the objective of maintaining flock health," Lobb said. "In Denmark, where low level antibiotics have been banned, disease has increased and the use of therapeutic medications has increased more than 90 percent," he said.

The industry's subtherapeutic use of all antibiotics is down some 30 percent since 1996, Lobb added, and further regulations would jeopardize the economics of the industry. chickens

Egg laying hens are packed into battery cages which are lined up in rows in huge factory warehouses. (Photo courtesy Farm Sanctuary)
Still, Pittle and others expect Congress to look at both subtherapeutic use and at a possible phaseout of the industry's use of antibiotics that are also used to treat people.

The American Medical Association supports the phaseout. Some pou

ltry manufacturers have already begun to change their ways, according to Margaret Mellon, director of UCS' Food and Environment Program.

"It doesn't take rocket science to create the healthy, non stressful conditions that make it possible to avoid the use of antibiotics," said Mellon. "The European Union has now banned use of all antibiotics used as growth promoters, and some mainstream U.S. poultry producers are pulling back from the use of medically important antibiotics for subtherapeutic uses."

Four of the five largest producers have stopped use of any Cipro-like antibiotics, and a host of fast food retailers, including McDonald's, Popeye's and Wendy's, have publicly committed to purchase poultry only produced without these Cipro-like antibiotics.

The U.S. Food and Drug Administration estimates some 150,000 Americans in 1999 developed a Cipro-resistant campylobacter infection from contaminated chicken.

"We don't need to use these enormous quantities of drugs to produce affordable, safe meat," Mellon said. "All we need to do is persuade our poultry producers to throw away their drug crutches and move on to new, better managed systems that don't depend on the use of excessive antibiotics."

The IATP/Sierra Club report can be found by clicking here.

The Consumer Reports article and report can be found at:

What You Can Do to Protect Yourself, courtesy of Consumer Reports: