New Research: Cow Pee Can Spread Antibiotic Resistance Through the Soil

By Lisa Raffensperger | November 12, 2012 12:50 pm

A row of cows' behinds

Antibiotic resistance is a well-known menace: Witness the dangers of hospital-acquired MRSA infections, or the totally drug-resistant tuberculosis found in India earlier this year. FDA statistics show that over 80 percent of antibiotics used in the US are given to livestock, and heavy animal use is thought to be one of the drivers of resistance among human pathogens. So it behooves veterinarians and public health officials alike to stamp out antibiotic resistance in animals.

In the hunt for how this resistance develops, though, scientists have been mostly looking at bacteria inside the digestive system. But it turns out they might have, er, the wrong end of things—a new study finds that drugs excreted in pee and feces may be even more worrisome than those circulating in the bloodstream.

As the antibiotic ceftiofur has become more widely used in cows to treat respiratory disease and infections, E. coli and Salmonella in their guts have become increasingly resistant to it. Similar drugs to ceftiofur are used in people to treat pneumonia and meningitis; the threat to human health is serious enough that earlier this year the FDA announced new restrictions on ceftiofur and its sister drugs. But the mystery has been how resistance develops in cattle. The drug is injected, not taken orally, and it doesn’t appear to act on cows’ guts.

To find out how resistance was spreading, Murugan Subbiah and colleagues at Washington State University first began with the fact that broken-down antibiotics have been found in cow feces and urine, and that these molecules are known to be lethal to bacteria. What remained to be seen, though, was whether urine could therefore shape the bacteria population in soil, encouraging resistant bacteria to spread.

In the study, published last week in PLoS One, the team had the icky task of collecting urine and feces from cows dosed with ceftiofur. When they mixed up cocktails of excrement and soil, they found that urine from treated cows killed off normal E. coli and encouraged the spread of the resistant ones. Thus, simply contaminating a patch of soil with pee may be enough to create resistant bacteria in the wild. And when dairy calves were given bedding sprayed with resistant E. coli, within a matter of days they showed resistant E. coli in their guts as well, showing how easily bacteria made resistant outside the cow’s body can leap into the cow’s guts.

Bacteria are well-known for swapping antibiotic-resistance genes amongst themselves, and this particular kind of resistance has been found to move easily between different species of bacteria. Thus resistant E. coli in the soil could spread their powers to numerous other kinds of pathogens also present there, including others that infect humans through meat or produce.

The scientists propose that if urine is to blame for passing on resistance, solutions may come easier—for instance, farmers may be convinced to change their waste management practices. Just don’t expect a cow potty anytime soon.

Image courtesy of St0rmz via Flickr.




CATEGORIZED UNDER: Environment, Health & Medicine
  • Chuck Currie

    Of course this primarily applies to Concentrated Animal Feeding Operations (CAFO). Pastured, grass fed, cattle and dairy cows, need little to no antibiotics. Read any Joel Salatin book if you want to know how a real sustainable farm works. His latest, “Folks, this ain’t normal” is a hoot.


  • Krishna

    It is ironic that it is popular custom in India (especially in rural areas) where cow’s urine is sprayed around a house as it is considered to have anti-bacterial and insect repellent properties. I am not sure if any scientific proof is available regarding these effects, but there seems to be strong evidence that they can increase spread of resistant bacteria.

    Anyhow, this custom, however bizarre and bordering superstition it may be, further complicates the problem of increased spread of resistant-bacterial infections in humans.

  • Andrew W

    “Pastured, grass fed, cattle and dairy cows, need little to no antibiotics.”

    No, antibiotic use in dairy cattle is common throughout the world, conditions most commonly treated would be: mastitis, lameness, and metritis.

    In past decades shed effluent was commonly allowed to find its way into natural waterways, these days, to protect the natural environment, it’s usually spread directly back onto the pasture.

    As antibiotic contaminated milk (not acceptable in milk for human consumption) is included in this pasture spread effluent, and that’s milk from mastitis cows treated with high concentrations of antibiotics in intramammary suspensions, I’d expect this to be another source of increases in antibiotic resistant soil micro-organisms.

  • floodmouse

    Humane = Healthy

    ( . . . in farming, as in every other area of life . . . )

    Okay – now I’m waiting for someone to post a nasty reply, saying I am just being sentimental. Let’s see if they still keep saying it when they have antibiotic-resistant respiratory or digestive disease, fostered by antibiotics spread through the soil in cow pee . . .

  • Angela


    anyonenolder than 13 years old cn sign via internet.. we still short 17.000 signatures… Please help. ALL USA people, not only CA

    My friend recently passed away at 55. He got a Knee surgery, developed an bacterial infection: none of the antibiotics or viral medications would make it work. He was a regular home food eater, not an organic shopper .Relatives can’t understand why this happen, since he was a very healthy guy all his life, and he avoid eating outside, AND STILL that happen : but FAT, FAT, FAT factor damaged his kness, and paid with his life from eating food not being label as GMO product.

  • Band Mamma

    Am I the only one disgusted that we’re being talked to like children? Cow pee? Cow potty? Seriously? We’re not a bunch of five year olds. Can we not grow up and use the big words, or are we such a prudish society that ‘urine’ and ‘feces’ are now taboo words?

    …steps off soap box.

  • Pippa

    What on earth has GMO food to do with your friends death? I am sorry to hear of his problems, but do not see any link with GMO foods at all. Antibiotic resistance in the infective organism maybe – but that is a completely different topic.
    Hey band mama – feel free to get back on the soap box. I agree. And articles are getting shorter and shorter too, with lots of pretty pictures just in case we can’t read for too long.

  • Chuck Currie

    “No, antibiotic use in dairy cattle is common throughout the world, conditions most commonly treated would be: mastitis, lameness, and metritis.”

    No, pastured cows have a very low incidence of mastitis, lameness and metritis. These are diseases related to grain fed cows and improper milking.


  • Andrew W

    “No, pastured cows have a very low incidence of mastitis, lameness and metritis. These are diseases related to grain fed cows and improper milking.”

    Having started dairy farming 30 years ago after finishing a B Agricultural Science degree and having milked on dozens of pasture farms in that time including a couple I’ve owned, and used lots of different antibiotics on lots of sick cows, color me skeptical on your expertise.

  • Andrew W

    2. Krishna Says:

    Surely you know that the main nitrogen containing molecule in urine is urea, and that this easily breaks down to ammonia? – obviously a fairly strong disinfectant.

  • geack

    @ 2. Krishna, That would only be a problem if cows in rural India are regularly treated with antibiotics. Are they?

    @8. Chuck, Where are you getting your info? Pastured dairy cattle come up lame all the time (they’re walking around in a field, after all), and mastitis is fairly common in all nursing mammals (ask your friends’ wives). It’s not especially rare in breeding cows, even if they aren’t used for dairy production (show cattle, rodeo breeding, etc.) I’m not arguing that we’re doing things right with feedlots and antibiotics, but let’s stick to the facts.

  • September Amyx

    @geack, what you just said is that you are experiences in what you were taught and you bought it. If your teacher had told you that mastitis was spread by organism ‘xxxx’ and therefore needed to be treated with antibiotics, then you treated with antibiotics. The problem with this is that 1. You can be made to believe lies or limitations unknowingly from your educators, who may not know they are doing the same thing, which is 2. Believing a report or research findings that are logically presented and logically sound from that. The contrived narrow focus view of reports and research is skewed, purposefully or not, the same way that new reporting is skewed, by your belief system. That’s got to be irrefutable. The othew way it’s skewed is the way the research is organized, performed, and the resulting theory or facts. I’ve been in medical research for over 15 years, and I can tell you I’ve seen research that didn’t allow for certain paramenters or action that severely affected the outcome, or maybe even made the research useless. I could only report my findings to the researchers or up my chain, I don’t know what results came out of that.
    Although there are many diseases that can be contained in milk, people have been able for the most part survive despite drinking unpasteruized milk. Tuberculosis was such a horrible disease last century, that when Pasteur’s theory in application prevented the wide spread of the disease in the population. Pasteurized milk doesn’t harm people! But it is a significant co-factor in the current population’s depletion of glutathione. Pasteurization inactivates the enzymes that help people achieve the glutamine into glutathione reaction. The result is that a huge amount of natural antioxident (that was practically all the antioxident by percentage) used for maintaining health disappeared rapidly. Since glutathione repairs stress damage, The it wasn’t realized until people who had no reason or want to be unhealthy were dropping like flies. The reason was found, but it was also found that the way glutathione is produced in the body is at the end of a long string of enzymatic activity. That activity was independent of the time of consumption of food. The glutamine in the body is produced during and in the middle of an enzyme chain of processing. Glutamine taken orally isn’t recognized by the body as the same glutamine produced in that chain reaction that in the end makes the glutathione. So it’s a useless supplement, but it’s sold and no one is told the truth.
    So we have a cure for a large portion of the health crises, drink raw milk. Since it didn’t harm our forefathers with the exception of tuberculosis, the only problem would be if cows had tuberculosis to pass, which they don’t. But just at the time everyone was catching on to raw milk, all of those FBI raids started on the people who were making it available. Bet you didn’t know that, even with all your experience with the production of milk. So experience is not necessarily equate with truth, or answers to problems.

  • Philip Blumer

    May I add my personal experience? I was born in 1926 on a farm and we drank raw milk. Our cows were pastured in summer but fed indoors in winter. Our cows often had mastitis; you could see the blood and pus as you finished milking. Sometimes we’d discard the contaminated milk, but mostly we didn’t.

    I and my four brothers survived. However, I had frequent strep throats, and sometimes I would get very sick from them. My brothers were less susceptible, although my younger brother had some strep throats. (My uncle died of a strep infection that started in his throat.)

    Perhaps one could find statistics on deaths from strep infections in the late 20s and early 30s.

  • bharati

    Sure no one wants to know but ….

    Of course I love milkshakes, adore any amount of ice cream, butter, and most of all plain yogurt! But I have given it up.

    It was hard, seemed impossible but oh, the feeling of well-being after a few months of NO animal products was and is beyond amazing. I just did it as a personal experiment but was really astonished at the result. Not fanatic just wanted to see what would happen. Like all major changes, it was sometimes annoying, took time to understand how to do it, what to substitute, felt silly and awkward often, etc.

    Folks, the result is incredible!

  • Andrew W

    September Amyx, you’re just trying to hijack this thread to promote your theories on raw milk vs pasturised milk.


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