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How industrial farming techniques can breed superbugs

August 9, 2017 at 6:35 PM EDT
As high-density, industrial-scale livestock farms have become fertile breeding grounds for disease, they’ve also become a major source of drug-resistant superbugs. Science correspondent Miles O’Brien and economics correspondent Paul Solman team up to report on how scientists are studying how superbugs can get into the food supply.

Find all of the stories in our series Stopping Superbugs

JUDY WOODRUFF: But first: our special series Stopping Superbugs.

This week science correspondent, Miles O’Brien and economics correspondent Paul Solman tag-team again for a look at how the use of antibiotics in livestock can lead to unhealthy, even dangerous outcomes.

Miles begins at a Missouri pig farm, as part of our weekly science series, Leading Edge.

MILES O’BRIEN: Pig farmer Russ Kremer is up early, tending to his herd, talking to the animals.

RUSSIANS KREMER, Heritage Foods: I have the ability to interact with pigs. I think that they are the smartest, most social animals. I tell people that, if you like kids, you love pigs.

MILES O’BRIEN: He is the fifth generation in the Kremer clan to farm this plot of land in Frankenstein, Missouri. He introduced me to the newest residents.

RUSS KREMER: Everything that we do on this farm as far as feeding, and as far as production, as far as genetics, that all has to do with keeping them healthy.

MILES O’BRIEN: Russ Kremer is obsessed with keeping his pigs healthy, because he knows firsthand that his own health depends on it.

RUSS KREMER: That’s about as good as it’s going to get.

MILES O’BRIEN: Thirty years ago, the farmer from Frankenstein created a monster after he adopted industrial farming techniques to increase his pig production.

RUSS KREMER: My pigs were unhealthy. I would go through my pigpens three times a day, injecting them with antibiotics to cure some sort of chronic diseases that I had on my place.

And, in fact, I was actually growing superbugs in this farm and didn’t know it.

MILES O’BRIEN: How he found out nearly killed him. He was gored in the leg by a boar, and the wound became infected. His doctor told him not to worry, antibiotics were the cure. But it wasn’t that simple.

RUSS KREMER: We tried two different tetracyclines. We tried streptomycin. We tried erythromycin, amoxicillin, seven different antibiotics in total, to no avail.

MILES O’BRIEN: So he checked the reports from his veterinarian to see what infections his pigs had and what antibiotics worked for them.

RUSS KREMER: It came back, resistant, resistant, resistant, resistant. And finally, aha, there was one antibiotic at that time that had some effect on that disease. They treated me, and thank God there were this new-generation drug. And so that transformed my life.

MILES O’BRIEN: Molecular microbiologist Lance Price also grew up on a farm, a cattle ranch. He watched firsthand as a neighboring dairy went from a small-scale family operation to an high-density, industrial-scale farm.

They are called concentrated animal feeding operations. Lance Price says they are fertile breeding grounds for disease.

LANCE PRICE, George Washington University: You pack them together, snout to tail in the case of pigs, and beak to feather in the case of chickens and turkeys, they’re going to share bacteria.

So we have engineered a system that makes them sick. Rather than change that system, we actually just add low doses of antibiotics to try to prevent infections.

MILES O’BRIEN: Price and his team at George Washington University conduct large epidemiological studies of meat that is sold in grocery stores. They culture the bacteria found on the meat and test to see how they react to disks saturated with antibiotics. He is hunting for superbugs.

LANCE PRICE: If they’re susceptible, that is, not resistant, to the antibiotic, they will be inhibited. They won’t grow near the disk. But when they grow right up to the disk, like all of these, that means that that bacteria is resistant to all those antibiotics. You don’t want to get infected with one of these.

And these are bacteria that we actually isolated from the food supply.

MILES O’BRIEN: He sequences the genomes of E. coli from food and from people, comparing them to a database of 7,000 distinct types of the bacteria.

LANCE PRICE: We’re trying to figure out, hey, did this urinary tract infection come from the E. coli from animals or from food?

MILES O’BRIEN: He says there is a strong case linking the use of antibiotics in livestock to the spread of drug-resistant bacteria in humans.

LANCE PRICE: So, on every grocery store shelf in this country, I guarantee you you’re going to find drug-resistant bacteria on the meats of those shelves. And then they get in our guts when we consume the meat from those animals.

Most of the time, that’s a dead end, right? We will eventually get rid of those bacteria. We will shed them away. But, sometimes, they will take hold.

MILES O’BRIEN: In the 1950s, farmers discovered feeding livestock steady, low doses of antibiotics made them grow faster. But this so-called subtherapeutic use of these precious drugs raised concern in the medical community and the government.

In 1977, the U.S. Food and Drug Administration proposed a ban on subtherapeutic uses of penicillin and tetracycline in animal production. But the rule was never enacted. And the problem worsened.

In 1989, human and livestock usage of antibiotics was about equal. Today, agriculture accounts for about three-quarters of all the antibiotics used in the United States.

MAE WU, Natural Resources Defense Council: We have to stop now. We have to stop abusing them now, so that we can slow this problem down.

MILES O’BRIEN: Mae Wu is a senior attorney at the Natural Resources Defense Council.

MAE WU: Using antibiotics and misusing them just to make animals get fatter or so you can cram more together and have more stressful conditions and feed them worse diets is the worst way to be using these incredibly important drugs.

MILES O’BRIEN: In 2010, the NRDC, sued the FDA to force it adopt its own rule. Instead, it released new regulations limiting the use of medically important antibiotics in animals to when it is necessary for assuring animal health and with veterinary oversight and/or consultation.

Liz Wagstrom is the chief veterinarian at the National Pork Producers Council.

LIZ WAGSTROM, National Pork Producers Council: The pork industry believes that the most judicious uses of antibiotics are those for treatment, control and prevention of diseases.

MILES O’BRIEN: Wagstrom says the pork industry will follow the FDA guidance, but she says pork producers will continue to use antibiotics as a routine disease-prevention tool even if there are no illnesses detected in their livestock.

LIZ WAGSTROM: It is a judicious and responsible use of antibiotics to go ahead and prophylactically treat some of those animals when we know they’re exposed, we know that it’s a specific disease, and we’re going to use that antibiotic for a defined duration of use.

MILES O’BRIEN: This is a huge loophole, as my colleague Paul Solman discovered in his conversation with Johns Hopkins University environmental health scientist Ellen Silbergeld.

ELLEN SILBERGELD, Johns Hopkins University: What has been stated as the recommendations, not enforceable policy, by the FDA is that agriculture shouldn’t use antibiotics for growth promotion anymore, but they are still permitted to use the exact same amounts of antibiotics in feeds for prevention. So, I think the category of prevention now has blown up.

MILES O’BRIEN: No need to worry about this at Russ Kremer’s farm in Frankenstein, Missouri. His pigs do not spend their life confined indoors cheek to jowl. They have much more space, easy access to pastures, even a wooded area Kremer calls his pig park.

He is trying to mimic what pigs would find in nature.

RUSS KREMER: This is the best place in America to raise pigs, in my mind.

MILES O’BRIEN: Right here?

RUSS KREMER: Right here.

MILES O’BRIEN: He rarely uses antibiotics at all, and then only if an animal is sick. Antibiotics saved Russ Kremer’s life 30 years ago. Today, he’s doing all he can to return the favor.

RUSS KREMER: They’re lifesavers. And what we have to ingrained into people’s mind, in society’s mind is we have to do everything we can to preserve them. It’s the most important, the most critical health issue in the world. And I’m here to do whatever I can.

MILES O’BRIEN: After I got back from Frankenstein, I sat down with Paul Solman to share some anecdotes from Russ Kremer’s bucolic pig farm.

So, Russ Kremer was ahead of his time, but the market has kind of caught up to what he is doing. It’s still a small piece of the big pie. Just a few thousand are raised in the way Russ does.

So, the question is, is it scalable?

PAUL SOLMAN: Well, in chickens, producers claim that 30 percent of the market or something like that, the chickens are raised antibiotics-free.

So, that’s where we’re going next, actually. That’s our next story.

For the PBS NewsHour, I’m economics correspondent Paul Solman.

MILES O’BRIEN: And I am science correspondent Miles O’Brien.