Maryn McKenna

Journalist and Author

Hospitals want patients to eat antibiotic-free meat

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Huge news, and hat tip to excellent food-policy writer Monica Eng at the Chicago Tribune: In a piece published Tuesday, she details that 300 hospitals in the Chicago area and nationwide have begun preferentially buying and serving meat that is raised without the use of antibiotics.

Using the ingredients is primarily a response to patient demand, said (Carolyn Lammersfeld, national director of nutrition at Cancer Treatment Centers of America) but the centers are also “watching the controversy over the nontherapeutic use of antibiotics and their potential to cause resistant strains of bacteria.”

The issue is of particular concern for cancer patients, who have compromised immune systems, she noted. “Many also might already being taking antibiotics, so they don’t want additional ones in food if they can avoid it,” Lammersfeld said.

The drug-free meat is more expensive, but the cost balances out within the budget:

(Diane Imrie, director of nutrition services at Fletcher Allen Health Care in Vermont) estimated that her food costs rose about $67,000 last year when she switched to antibiotic-free chicken from conventional. “But that’s also about the same cost as treating a single MRSA infection,” she said.

It’s interesting to see this story land just as a new paper in Foodborne Pathogens and Disease is making the rounds. The paper (Jiayi Zhang, Samantha K. Wall, Li Xu, Paul D. Ebner. “Contamination Rates and Antimicrobial Resistance in Bacteria Isolated from “Grass-Fed” Labeled Beef Products,” doi:10.1089/fpd.2010.0562) compares the bacterial burden in grass-fed and conventionally raised beef and finds no significant  differences: equivalent amounts of both drug-sensitive and drug-resistant bacteria in both types of beef. 
It concludes, “There are no clear food safety advantages to grass-fed beef products over conventional beef products” — an assertion that’s likely to be seized on by those who see no need to change current antibiotic use in agriculture. (For an example of that POV, here’s the testimony from last week’s House of Representatives hearing by Richard Carnevale, DVM of the Animal Health Institute.)
I suspect though that the paper’s analysis doesn’t look far enough. Here’s one example: the authors found that Enterococcus species in both conventional and grass-fed meat were resistant to chloramphenicol, erythromycin, flavomycin, penicillin, and tetracyline — drugs that are used in agriculture (and that could have been given to the grass-fed animals, which were not guaranteed to have been raised drug-free). But  Enterococcus spp. isolates from conventional beef were more frequently resistant to daptomycin and linezolid — which are new-to-market drugs of last resort in human medicine that are not given to animals.
That finding, right there — the migration of resistance to a human-only drug into an organism carried by an animal — signals one of the insoluble problems of overuse of antibiotics. Once created, resistance factors move horizontally among bacteria, from the farm to humans, and apparently in this case, from humans to the farm as well. We have almost no control over their movement, and on the agricultural side, almost no surveillance to detect it, either. That argues for reducing the overuse of antibiotics in human medicine and on the farm. 
If this health care coalition’s refusal to purchase meat raised using antibiotics helps to enlarge the market for drug-free meat, then it may reduce ag antibiotic use, and therefore the selective pressure that encourages resistant organisms to emerge. That can only be a good thing.
(The paper in Foodborne Pathogens has also been covered by my former colleagues at CIDRAP; here’s their link.)

A blog reaction so perfect I want to print the whole thing…

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(…but I won’t, because it’s not fair use or good blogger behavior. But I want to!)

Melissa Graham of Chicago had a great corporate life — and then she re-evaluated, became a chef and caterer, and began organizing in Chicago for sustainable local food, farmers’ markets, and a family-friendly food system. She blogs at the food and food-policy blog The Local Beet. And she’s written a reaction to SUPERBUG that not only completely gets the book, but is emotional and thoughtful and moving besides.

She says, in part:

Before reading Superbug, the question of confinement raised animals was an ethical one for me – whether the misery inflicted upon animals and, for that matter, the humans working in those facilities by the putrid conditions outweighed the need to eat cheap meat. Even the environmental degradation resulting from the inevitable careless management of CAFOs seemed a distant and intangible casualty. For me, Superbug has changed the argument from one of ethics to a moral imperative. In every hamburger of unknown origin, I see Tony Love’s face or even worse that of Carlos Don IV.

Carlos was another healthy kid who left on a school trip to the mountain and returned with a 104°F fever. The first doctor diagnosed Carlos with walking pneumonia so his mother kept him home bundled and hydrated until she realized that he was beginning to hallucinate. She rushed Carlos to the hospital and the doctor’s ultimately diagnosed his condition as MRSA. A long slow death march ensued during which Carlos’s lungs dissolved and clotting choked off the blood to his lower intestines, legs and arms. In two weeks, he was dead.

After reading Carlos’s story late in the evening, I woke a bewildered little locavore from a dead sleep to scrub his hands clean. I hugged him as tightly as I could.

…[recently] I had the pleasure to hear Ruth Reichl speak and she implored the audience to stop eating confinement raised animals. As she put it, if everyone stopped buying them and eating them, the practice would be history. Knowing what I now know, I think it’s our moral duty.

To give the post the traffic it deserves, please go here.

Antibiotics and farming — how superbugs happen

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Constant readers: There’s an important new paper that’s been out for a week that I haven’t gotten to you. I apologize; it’s been busy. (Let’s not even talk about the important paper that’s been out for two weeks. Maybe over the weekend…)

We’ve talked for ages now about the potential dangers of unrestricted antibiotic use in agriculture, and how it’s analogous to the inappropriate antibiotic use that human health authorities disapprove of in humans. The main culprits, in farming, are subtherapeutic dosing, also known as growth promotion — that’s giving routine smaller-than-treatment doses to animals to increase their weight — and prophylactic dosing, which is giving a treatment dose to an entire herd or flock either routinely, if there is thought to be a disease threat, or when there is known to be disease in some members of the herd/flock. In either case, animals are getting antibiotics when they do not need them — when they are not sick. And just as in humans who take antibiotics when they are not sick, or take too-low doses when they are sick (such as not finishing a prescription), these practices in animals encourage the development of resistant bacteria.

(Necessary comment here: No one, to my knowledge, objects to giving the appropriate doses of antibiotics to animals that are sick. Why would you?)

The interesting research question is how, exactly, resistance develops. (My real scientist readers may want to take a break, or cut me a break, for the next few sentences. Please.) The classical assumption has been that, through a variety of stimuli and the random copying errors of reproduction, bacteria are constantly acquiring small mutations. Some of those may give the bugs an advantage when they are exposed to a drug, some slight difference that allows the bacteria to disarm or turn aside that drug’s particular method of assault — so that the weak die, the strong survive, and the strong then reproduce more abundantly into that extra living space freed up by the death of the weak. The survivors and their descendants retain that mutation, because it gave them an advantage against the drug. And because bacteria can share resistance factors not only vertically mother-to-daughter, but horizontally in the same generation, once the resistance has emerged, it is likely to spread.

But no matter how quickly it spreads, that process I’ve just described involves acquiring resistance to just one drug or drug family at a time. Provocative new research from Boston University’s medical school and deoartment of biomedical engineering now suggests, though, that multi-drug resistance can be acquired in one pass, through a different mutational process triggered by sublethal doses of antibiotics — the same sort of doses that are given to animals on farms.

In earlier work, the authors found that antibiotics attack bacteria not only in the ways they are designed to (the beta-lactams such as methicillin, for instance, interfere with staph’s ability to make new cell walls as the bug reproduces, causing the daughter cells to burst and die), but also in an unexpected way. They stimulate the production of free radicals, oxygen molecules with an extra electron, that bind to and damage the bacteria’s DNA.

That research used lethal doses of antibiotics, and ascertained that the free-radical production killed the bacteria. In the new research, the team uses sublethal doses, and here’s what they find: The same free-radical production doesn’t kill the bacteria, but it acts as a dramatic stimulus to mutation, triggering production of a wide variety of mutations — what the researchers, in a press release, called “a zoo of mutants.” The plentiful, scattershot mutations included ones that created resistance to a number of different drugs — in some cases, even though no mutation was present that created resistance to the drug being administered.

You can easily see how this is applicable to factory farming: The sublethal dosing applied experimentally is analogous to the subtherapeutic dosing used in agriculture. Is it applicable to MRSA? Yes, absolutely. The two organisms the researchers used to test their hypothesis were S. aureus and E. coli.

making the implication clear, senior author James J. Collins said on the paper’s release:

“These findings drive home the need for tighter regulations on the use of antibiotics, especially in agriculture; for doctors to be more disciplined in their prescription of antibiotics; and for patients to be more disciplined in following their prescriptions.”

The cite is: Kohanski MA, DePristo MA and Collins, JJ. Sublethal Antibiotic Treatment Leads to Multidrug Resistance via Radical-Induced Mutagenesis. Molecular Cell, Volume 37, Issue 3, 311-320, 12 February 2010.

UPDATE: There’s a great discussion of the paper at the blog Mental Indigestion.

Postscript: I suppose I’ve been working too long without a break, because while I was reading about this process of creating multiple resistance factors at once, what I heard in my head was Mickey Mouse chirping: “Seven at one blow!”

Antibiotics and farming — CBS follow-up video

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Constant readers, CBS News has posted some follow-up video to its two-part series last week on antibiotics in agriculture. It features Dr. David Kessler, former Commissioner of the Food and Drug Administration (which under its current leadership has vowed to re-examine farm-antibiotic use), and Eric Schlosser, author of Fast Food Nation.

They talk about the protests CBS has received for airing the package, the concerns public health authorities have over the lack of  data on the amounts and types of antibiotics used, and much more. I especially love Schlosser’s comment: “I’m a meat-eater.” It’s important, I think, to say that being critical of antibiotic use does not mean being opposed to animal agriculture, or wanting to see farms shut down. It means being concerned for the health of farm animals, farm families, and everyone affected by growing antibiotic resistance — which is, you know, everyone.

(H/t @EdibleSF for flagging the video’s release.)


Watch CBS News Videos Online

(Hey, that’s my first embedded video!)

New film on organic farming (for European readers and others)

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This is a little outside our usual subject matter, but it follows nicely on the past two days’ discussion of the CBS packages on antibiotics in farming, so:

What looks like a marvelous new documentary exploring environmental damage and human illness from pesticides and other farming chemicals is coming out in France, but needs assistance to get onto the international festival circuit. It’s called Nos enfants nous accuseront (Our Children Will Hold Us Responsible), and among other things, looks at the efforts of a French village to make all the food served in its schools organic — which, even in food-centric France, is much harder than it sounds.

You can view the trailer here. The more clicks, the more the film will be taken to have support, and the higher its rankings will go for festival consideration.

It comes well-recommended by friends of mine in Paris, so I hope you’ll take a look.

CBS antibiotics and farming, day 2 – and more on the Danish experience

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Constant readers, I hope you watched the second day of CBS News’ series on antibiotic use in farming, and how it promotes the emergence of antibiotic-resistant infections in animal and humans. I found it surprisingly hard-hitting. Here’s the video and the text version.

Most of the report explored the farm experience in Denmark, which in 1998 banned its farmers from using small doses of antibiotics to make animals gain weight faster — the practice that’s various called subtherapeutic dosing or growth promotion. Important distinction: The country still permits sick animals to be treated with antibiotics; the ban extends only to giving drugs to animals who are not sick.

That ban has often been represented as a failure for Danish farming [NB: See the update below], but research on the results shows that it was actually a success. Here’s an article by Laura Rogers of the Pew Charitable Trusts explaining what happened in Denmark from her own on-the-ground reporting:

Antibiotic use on industrial farms has dropped by half while productivity has increased by 47 percent since 1992. Danish swine production has increased from 18.4 million in 1992 to 27.1 million in 2008. A decrease in antibiotic-resistant bacteria in food animals and meat has followed the reduced use of these vital drugs. …

The average number of pigs produced per sow per year has increased from 21 to 25 (this is an important indicator of swine health and welfare, according to veterinarians). Most important, total antibiotic use has declined by 51 percent since an all-time high in 1992. Plus, the Danish industry group told us that the ban did not increase the cost of meat for the consumer.

 There are multiple scientific papers done by Danish authors backing up her observations. Here are just a few from just last year:

  • Antibiotic-resistant organisms in chickens raised in Denmark declined since the ban — but they remain high in chicken meat imported from other countries that do not have such bans, and passed to Danish consumers who ate that imported meat. (Skjot-Rasmussen et al., May 2009)
  • Antibiotic resistance in E. coli in pigs increases when pigs are given antibiotics, and those antibiotic-resistant organisms pass to humans (Hammerum et al., April 2009)
  • Antibiotic-resistant organisms found in pigs when they are slaughtered increase when pigs receive more antibiotics (Abatih et al., March 2009)

The industry that supports industrial-sized farms has strongly objected to the CBS series. You can see one detailed response here, from Pork Magazine. The Minneapolis-based Institute for Agriculture and Trade Policy predicts that this is likely just the first wave, and that opposition to any change in agricultural practices will grow stronger as a bill to curb unnecessary antibiotic use gains traction in Congress.

And — you knew I had to do this — here comes the obligatory self-promotion: There is a primer on antibiotic use in farming, and an account of the emergence of MRSA ST398 as a result of antibiotic use in pigs, in SUPERBUG. Which is now 41 days away from publication. And is available for pre-order at a discount! But you knew that.)

UPDATE: FairFoodFight has a great post and a long comments conversation about the CBS series, ag antibiotic use, and particularly the World Health Organizaton research that originally made people doubt the “Danish experiment,” The WHO report is here and a Pew analysis of it is here.

CBS antibiotics and farming package, day one

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Constant readers, I hope you saw the CBS News package on antibiotics in farming Tuesday night. (It continues Wednesday.) MRSA played a prominent role, in an account of infections among workers at a chicken plant (the same outbreak, I think, as was described by Prevention magazine last August) and in questions about MRSA in pig farms in the Midwest (with a prominent mention of Tara Smith’s research into “pig MRSA” ST398).

Here’s the 7-minute video and the text version.

Earlier Tuesday, CBS’s Early Show ran an additional package on the death of a Chicago toddler from MRSA. That toddler’s name is Simon Sparrow, and you’ll be able to read his sad story — told by his mother, Everly Macario — in SUPERBUG.

Farming and antibiotics – and voices from the ag side

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There’s a tremendous amount of buzz in the blogosphere about a series of pieces that are supposed to run on CBS News over the next several days, looking at the use of antibiotics in agriculture. For one of many posts on the topic, look at this piece from Food Safety News, an online newsletter founded by the food-safety attorney Bill Marler.

[UPDATE: CBS has put up the first video teaser for the package.]
[SECOND UPDATE: An excerpt from the Early Show, likening growth promoters to a “ticking time bomb” and to “putting (antibiotics) in your kid’s cereal so they won’t get sick”] 

The whole issue of how antibiotics get used in agriculture — as growth promoters, as prophylatic treatment to prevent spread of infection within a farm, or as true treatment — is intensely controversial. For a sense of how farmers feel embattled, read the comments to this entry at FairFoodFight on whether there is a distinction between “Big Ag” and “small ag.” and consider that the PAMTA legislation I posted about in December, which would require veterinarian oversight of farm use of antibiotics,  has been strongly opposed by agricultural interests every time it has been introduced. (Large-farm use of antibiotics, let me remind you, has been concluded to be the driver behind the emergence of “pig MRSA” ST398.)

But I recently ran across two pieces online that I want to draw your attention to, because they demonstrate that thinking in agriculture about antibiotic use is not monolithic, and may be changing. Both were posted on the same site, the Illinois-based Agri-News Online.

First, from James Pettigrew, a professor of animal sciences at University of Illinois, a pessimistic but realistic assessment of how changing public attitudes about antibiotic use will affect what farmers can do, “Broad restrictions on antibiotic use would reduce animal welfare and productivity”:

Many of us hope there will not be a broad ban on antibiotic use, but it is difficult to predict what will happen. Restrictions on antibiotic use may come from Congress, from regulatory agencies or from customers. The nature and extent of future restrictions are now unknown, but the direction is clear. There will be tighter restrictions on antibiotic use in the future. …
…Planning for restrictions on antibiotic use can be valuable even if those restrictions are never imposed. The things you might do in the absence of antibiotics are also likely to be quite valuable if you continue to use antibiotics as you do now….

Second, from a writer named Darryl Ray, who isn’t otherwise identified, a plea for refraining from demonizing critics of antibiotic use, “Animal producers should take antibiotics criticism seriously”:

…Many — and we would suggest it is the vast majority — of those who question the present practices of antibiotic use in animal agriculture eat meat on a regular basis.
Rather than malign the critics, a better course of action for meat animal producers might be to take the issue seriously.
…To categorically claim that it is a reasonable practice to routinely administer antibiotics to animals that are not diseased will strike many as being outside what they have come to believe to be an appropriate use of antibiotics.
…It is important to consider the possibility that indisputable evidence will emerge that the continued and persistent “overuse” of antibiotics in livestock production causes or accelerates the development of super-germs for which there are virtually no effective medications.That would be a public relations and economic nightmare for production agriculture. Thought of in that light, taking the issue seriously and making meaningful adjustments in antibiotic use may have the most appeal of all.

I don’t know that I agree entirely with either writer. But I’m tremendously encouraged that a publication that speaks entirely about farming, to farmers, can run thoughtful pieces looking at ag antibiotic use from several angles, as something to be evaluated, debated and potentially adjusted, and not as a practice that cannot be examined but must be maintained unchanged.