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Going Hog Wild: Weaning Antibiotic-Resistant Bugs Out Of Pork

Pig Farm Antibiotics

First Posted: 02/11/2012 8:08 pm Updated: 02/11/2012 8:08 pm

After nearly succumbing to an antibiotic-resistant infection contracted from one of his hogs, Russ Kremer went cold turkey. He exterminated his diseased pigs and swore off the antibiotics he'd long-used to boost his herd's growth and prevent the illnesses so common in concentrated animal feeding operations, or CAFOs.

Now, more than 20 years later, he says his farm is organic, sustainable, humane and still nearly as efficient as the typical industrial CAFO. Plus he's eliminated the $16,000 a year he used to spend on veterinary and drug bills. And he hasn't sacrificed his pigs' health in the process. If anything, the opposite is true for Fred, Barney, Wilma, Pebbles, Bamm-Bamm and the other 500-some pigs that roam his 150-acre farm.

"My mortality rate is less than 1 percent after they leave their mother. In the industry, many people are seeing a 5 to 10 percent loss," Kremer, now president of Ozark Mountain Pork Cooperative in Missouri, told The Huffington Post. "I don't even own a syringe anymore."

Better yet, he has remained healthy himself.

Kremer's story exemplifies the findings of a growing number of scientific studies on the effects of antibiotic use in livestock. As HuffPost previously reported, the 29 million pounds of antibiotics given to livestock every year -- about four times the amount consumed by people, and mostly used at sub-therapeutic doses -- appears to be contributing to a rise in drug-resistant infections in both animals and people. The most infamous of the microbes: methicillin resistant Staphylococcus aureus, better known as MRSA.

"We've worked our way into a pickle," said David Wallinga, a senior adviser at the Institute for Agriculture and Trade Policy. The more antibiotics we use, the more microbes become resistant to those drugs -- even to our "biggest guns." It's a microscopic survival of the fittest.

Wallinga and his colleagues recently found drug-resistant microbes in 65 percent of about 400 pork products sampled from a dozen grocery stores across Iowa, Minnesota and New Jersey. Nearly 7 percent of the products had measurable amounts of MRSA, according to their study, published in January in the journal PLoS ONE.

To the team's surprise, MRSA thrived in both conventional meat and meat labeled as antibiotic-free. (The "antibiotic-free" label is not regulated.)

At first glance, this finding might contradict other research, such as a study also published in January from the National Animal Disease Center (NADC) in Ames, Iowa. The intestines of piglets raised with antibiotics added to their feed accommodated both a greater number and wider variety of antibiotic resistance genes than the intestines of pigs not fed the drugs, according to that research. The treated pigs' innards were also colonized by more E. coli.

Still, both groups of pigs carried at least some resistant genes, the information that tells a microbe how to evade microbe-killing drugs. Only the presence or absence -- not quantity of MRSA -- was measured in the pork study.

"We find antibiotic resistance genes quite prevalent in all pigs, irrespective of antibiotic feeding. We think this may be partially due to the fact that at least in pig growing regions, the background flora that they pick up is already enriched with antibiotic resistance genes," said James Tiedje, a microbiologist at Michigan State University and researcher on the study.

This concept was illustrated in yet another study published last year. Wild pigs from an island off the coast of South Carolina were compared to organically raised pigs in the Midwest. In this case, the guts of the wild pigs had 1,000-fold fewer bacteria resistant to the tetracycline class of antibiotics compared to their organic counterparts. (An organic label does imply antibiotic-free certification.)

Kremer is well aware that antibiotic residue can persist in the environment and lead to resistance long after the last dose of antibiotics was used on that land. Fortunately, he set up his new operation on land that -- as far back as he's aware -- had only been used for organic farming. And he made every effort not to introduce any bad bugs or drugs, including bringing in only piglets that had been born via cesarean section.

A pristine farm may still not be enough to ensure safe pork. Wallinga of the Institute for Agriculture and Trade Policy notes that it remains unclear just how MRSA got into both the conventional and antibiotic-free retail meat he studied. MRSA may have encountered the pig on the farm, or the microbe may have hitched a ride in the slaughterhouse; at the processing plant; or en route to, or at, the store.

Research even suggests that effluent from sewage treatment plants is introducing antibiotic resistance into the environment that could be picked up by food animals. In other words, humans may well be the original source of the bugs, despite our predilection for blaming the 9 billion or so animals raised for food every year -- and their manure.

Regardless of its origin, debate abounds over just how much danger is posed by MRSA in meat. According to Liz Wagstrom, chief veterinarian for the National Pork Producers Council, that concern is minimal.

Gail Hansen, senior officer with the Pew Campaign on Human Health and Industrial Farming, added, "It's not clear what happens when MRSA is ingested." However, a lot is known about exposure through the blood stream, she said, which is the typical route of infection in the hospital and among livestock handlers such as Kremer.

Even if MRSA doesn't directly make you sick, it can share its lethal information with other bugs in your body, including those that are well-known to cause trouble when consumed, Hansen told HuffPost. Further, many of the resistance genes identified in the NADC study are not typically linked to the antibiotics used in the animals.

"Bacteria are promiscuous with their resistance genes," said Wallinga, highlighting a range of reservoirs of resistance, from manure lagoons to hog CAFOs to sewage treatment plants. "In general, it's not good to have these environments with a lot of bacteria and antibiotics."

Thad Stanton of the U.S. Department of Agriculture, who was involved in both the wild pig and NADC studies, added another wrinkle to the issue: The small physical size of the wild island pigs. "The world would starve if you had to raise feral pigs. We would have to bring in food imports from overseas where there is very little scrutiny," said Stanton. "We need to reach a balance between what is short-term expedient and long-term foolish."

The U.S. Food and Drug Administration issued a draft "Guidance on the Judicious Use of Medically Important Antimicrobial Drugs in Food Producing Animals" in 2010, which offers suggestions to the livestock industry on the prudent use of antibiotics in order to preserve the effectiveness of the drugs for the treatment of human disease. A final version has not yet been released.

Sponsored by Rep. Louise Slaughter (D-N.Y.), the only microbiologist in Congress, the Preservation of Antibiotics for Medical Treatment Act aims higher: the elimination of the non-therapeutic use of antibiotics in livestock. PAMTA was re-introduced in March 2011 after getting buried in Congress in 2007 and 2009.

"We know what to do, it's just a question of the leadership to get it done," Wallinga said.

Meanwhile, the market is spurring some change on its own. "The writing is on the wall," Wallinga told HuffPost. "The farmer that is the early adopter of antibiotic-free production is the farmer that is going to win the future market."

Kremer and the other farmers in his co-op provide pork to rising outlets including Chipotle, Applegate Farms and Whole Foods.

Of course, the consumer also has a major role to play in this line of defense. "'Antibiotic-free' doesn't necessarily mean that the meat is going to be free of antibiotic resistant pathogens," said Tara Smith, an epidemiologist at the University of Iowa College of Public Health and lead researcher on the MRSA study. "Safe handling practices are just as relevant for antibiotic-free raised meats and meats grown conventionally."

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