Clostridium difficile in the Food Supply

Image Credit: USDA / Flickr. This image has been modified.

Clostridium difficile in the Food Supply

Clostridium difficile is one of our most urgent bacterial threats, sickening a quarter million Americans every year, and killing thousands at the cost of a billion dollars a year. And, it’s on the rise.

As shown in C. difficile Superbugs in Meat, uncomplicated cases have been traditionally managed with powerful antibiotics, but recent reports suggest that hypervirulent strains are increasingly resistant to medical management. There’s been a rise in the percentage of cases that end up under the knife, which could be a marker of the emergence of these hypervirulent strains. Surgeons may need to remove our colon entirely to save our lives, although the surgery is so risky that the operation alone may kill us half the time.

Historically, most cases appeared in hospitals, but a landmark study published in the New England Journal of Medicine found that only about a third of cases could be linked to contact with an infected patient.

Another potential source is our food supply.

In the US, the frequency of contamination of retail chicken with these superbugs has been documented to be up to one in six packages off of store shelves. Pig-derived C. diff, however, has garnered the greatest attention from public health personnel, because the same human strain that’s increasingly emerging in the community outside of hospitals is the major strain among pigs.

Since the turn of the century, C. diff is increasingly being reported as a major cause of intestinal infections in piglets. C. diff is now one of the most common causes of intestinal infections in baby piglets in the US. Particular attention has been paid to pigs because of high rates of C. diff shedding into their waste, which can lead to the contamination of retail pork. The U.S. has the highest levels of C. diff meat contamination tested so far anywhere in the world.

Carcass contamination by gut contents at slaughter probably contributes most to the presence of C. diff in meat and meat products. But why is the situation so much worse in the US? Slaughter techniques differ from country-to-country, with those in the United States evidently being more of the “quick and dirty” variety.

Colonization or contamination of pigs by superbugs, such as C. difficile and MRSA, at the farm production level may be more important than at the slaughterhouse level, though. One of the reasons sows and their piglets may have such high rates of C. diff is because of cross-contamination of feces in the farrowing crates, which are narrow metal cages that mother pigs are kept in while their piglets are nursing.

Can’t you just follow food safety guidelines and cook the meat through? Unfortunately, current food safety guidelines are ineffective against C. difficile. To date, most food safety guidelines recommend cooking to an internal temperature as low as 63o C–the official USDA recommendation for pork–but recent studies show that C. diff spores can survive extended heating at 71o. Therefore, the guidelines should be raised to take this potentially killer infection into account.

One of the problems is that sources of C. diff food contamination might include not only fecal contamination on the surface of the meat, but transfer of spores from the gut into the actual muscles of the animal, inside the meat. Clostridia bacteria like C. diff comprise one of the main groups of bacteria involved in natural carcass degradation; and so, by colonizing muscle tissue before death, C. diff can not only transmit to new hosts, like us, that eat the muscles, but give themselves a head start on carcass break-down.

Never heard of C. diff? That’s the Toxic Megacolon Superbug I’ve talked about before.

Another foodborne illness tied to pork industry practices is yersiniosis. See Yersinia in Pork.

MRSA (Methicillin-resistant Staph aureus) is another so-called superbug in the meat supply:

More on the scourge of antibiotic resistance and what can be done about it:

How is it even legal to sell foods with such pathogens? See Salmonella in Chicken & Turkey: Deadly But Not Illegal and Chicken Salmonella Thanks to Meat Industry Lawsuit.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

19 responses to “Clostridium difficile in the Food Supply

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  1. Travelling in Mexico now and am far more afraid of C.diff than of scorpions!

    This bug has plagued expat communities typically striking after a round of antibiotics.

    Antibiotics are OTC here and also way overprescribed (as in the U.S.)

    Take away: stay away from high-risk (animal) foods; use gentle methods for travel related diarrhea; maintain a vibrant gut biome to crowd out the pathegenic

  2. My Aunt got C diff twice in hospitals when she was in her mid 80’s and had very limited mobility. It was terrible having to transfer from a hospital to a nursing home while this bug was making her life miserable. With the focus on profits and mass production, it’s no wonder that the animal food industry in responsible for creating a big part of this problem.

  3. A friend had surgery plus antibiotics a few years ago. She wasn’t feeling well enough to go with her husband one morning and insisted on staying home. When he got back, she was already cold. An autopsy revealed her body had been taken over by a normally harmless soil based organism. She used to buy “triple washed” salad greens and not rewash them before eating them. Before the antibiotics, this was safe enough. Apparently, it was not after antibiotics. Meat often carries dangerous bacteria. Salad greens can be dangerous after antibiotics.

    1. Absolutely true Jason! However, C. Diff’s natural habitat is animals, not plants. So while you occasionally find it on plants (typically after being contaminated with fecal material), meat eaters are at much higher risk of exposure. Not to mention that meat eaters are more likely to end up in a hospital which is the other major source of contact with the bacteria.

  4. Here is a link to a German documentary on glyphosate and Clostridium Botulinum (mentioned first at 7 min 30 seconds) – apparently glyphosate in animal food causes the benign bacteria in the cow gut to die, sparing the Clostridium bacteria with overgrowth of Clostridia, so the cows get ill and many die. Also the farmers get neurological and other diseases linked to glyphosate. Many of the calves are deformed. The problems in pigs from a farmer in Denmark are very similar. Glyphosate also damages the human gut bacteria causing gut dysbiosis and illness. Glyphosate needs to be considered as a possible factor in the development of Clostridia Diff – just as C Botulinum is mentioned in this documentary, surely C Difficile ought to be investigated as having a similar link? – unfortunately all in German without subtitles, so you may need to get it translated.

  5. <I have had C-Diff probably from a hospital stay or perhaps from too many antibiotics….I now refuse to take antibiotics and take as many probiotics as I know of- also eat a lot of Greek Yogurt, Kefir and anything else that is probiotic.

  6. Frightening indeed. But the abstract Dr. Greger cited does not limit itself to meats. Vegetables and ready-to-eat foods, including salads are also listed. Why does Dr. Greger not mention those in his blog? Much as I respect and enjoy Dr. Greger’s writing and videos, I increasingly fearful that he is losing his objectivity in favor of making his point. I agree with his point (Vegan, whole food, etc.) but science is science and if one is going to write about a danger to our food supply it seems best to write about all of it, not just about the part helps grind one’s particular ax.

    1. Maybe because he is focusing on the origin of the bug, plants don’t make the organism, they are contaminated by animal waste. Potentially any food that comes in contact with contaminated creatures and their effluent can transfer the microbes, but it originates with animals, so don’t shoot the messenger.

    2. Thanks for your comment Ron.

      You are right in that vegetables also are contaminated and this study shows that exactly but they also state that:

      C. difficile has been recognized recently as a pathogen or commensal in numerous animals, such as pigs, cattle, foals, horses, calves and poultry, and also in household pets (Avbersek et al., 2009; Riley et al., 1991). PCR ribotype 078 and/or toxinotype V strains are the predominant strains in calves and pigs (Goorhuis et al., 2008b; Keel et al., 2007; Rupnik et al., 2008). Interestingly, there is an overlap between PCR ribotypes found in humans and animals (Debast et al., 2009), raising the question of interspecies transmission and possible routes for exposure to CDI in humans.

      C. difficile is well known as a human pathogen responsible for CDI, but this bacterium is also responsible for animal infection and can be found in different food products including raw vegetables. This presence may reflect contamination of the environment (soil) or may be occurring during the processing step.

      Another review, also points out to the environmental contamination:

      Because of its spore-forming ability, C. difficile can survive in the environment for several months. The presence of C. difficile spores in hospitals is well established [ 82]. Also, gross contamination of farms such as pig facilities with C. difficile spores is commonplace. C. difficile could be isolated from the faeces of piglets 1 h after birth, presumably ingested from their environment. Within 2 days of birth, 100% of piglets had acquired C. difficile of the same molecular type that was found in sow faeces, sow teats, farrowing crates, and air on the farm [ 83]. There is evidence that vertical transmission does not occur in pigs [83]. Aerial dissemination of C. difficile on a pig farm has been shown to correlate with the activity of personnel within farrowing units [ 84], suggesting that staff might be at increased risk of ingesting airborne C. difficile spores. Contamination of the pig farm environment was confirmed in another study where C. difficile prevalence in the environment increased from 0% to 61% of sites within a pig farrowing facility only 1 month after it had been occupied by pigs [ 85]. C. difficile spores and vegetative cells are shed into the immediate environment in the faeces of both scouring and non-scouring pigs, underscoring the importance of high carriage rates in apparently healthy piglets [ 83]. The carrier state has also been emphasized in mouse studies that have demonstrated a marked increase in spore shedding when antibiotics are given to asymptomatic carrier mice. Subsequent spore-mediated transmission to immunosuppressed mice led to severe intestinal disease [86]. Another important consideration in relation to environmental contamination is effluent arising from piggeries. In Australia, piggery effluent is treated in anaerobic ponds to remove pathogens, and re-used to wash sheds or applied to agricultural land. C. difficile was shown to survive this process, with concentrations of viable C. difficile spores of >200 CFU/mL (MM, Squire and TV, Riley, unpublished data) posing a risk for infection of animals or contamination of agricultural produce.

      Besides environmental contamination in the vicinity of colonized or infected humans and animals, C. difficile spores can be isolated from practically any environmental site, provided that the correct culture enrichment methods are employed [ 87]. A large study by al Saif and Brazier [49] showed high rates of detection of C. difficile in soil and water samples in South Wales. Soil contained C. difficile in 21% of 104 samples, and 41% of the isolates produced toxin A. Water was positive in 88% of river samples, half of the sea, lake and swimming pool samples, and 5.5% of the tap water samples. Overall, 85% of the isolates produced toxin A. In 2010, similar percentages were found in Slovenia [ 88], where 61% (42 of 69) of the river isolates were positive for C. difficile.

      And therefore vegetables are contaminated as a result of the environment they grow in, but the origin is likely to be in the animals.

      Hope this answer helps.

  7. Not just C. diff in meats. Our bottom-line focused factory food industry ensures contamination and cross-contamination with many pathogens. Sign up for the USDA’s food safety/recall notices; daily notices of Salmonella and Listeria contamination to the point that I no longer buy frozen veggies anywhere.

  8. I’ve been reading the studies by Professor Monika Krueger in Germany of the dairy cows, farmers, farm families who have contracted C. Bottulism from the dust on the farms. The link is to grlyphosate, the labeled ingredient in Roundup, Visionmax and other herbicides created from glyphosate. Monsanto patented glyphosate as an antibiotic. But Dr. Krueger and her team discovered that Glyphosate kills the beneficial bacteria in the gut of animals and humans, and when the beneficial bacteria is unbalanced, the highly pathogenic bacteria takes over and kills the animals, sickens or kills the humans.

    There are numerous swtudies by Dr. Krueger online, although only the abstracts are available at Pub0Med,. She has stated the the C-Diff, as well as the C. Botulism can be found on all surfaces, including produce. Dr. Krueger has stated previously on her various web pages, that she is unable to identify the genetically modified organism that is resistant to Glyphyosate, and now the other herbicides that Monsanto is using to grow soy and xorn for animal feed in Louisiana and across the USA. They are: Dicamba, 2,4-D, also Glyphosate mixed with 2,4-D and called Rely. And lastly, Glufosinate which causes seizures of both animals and humans.

    Glyphosate is causing bees to starve according to a study from Argentina, while Bayer’s Neonics are causing colony collapse disorder.

    Trump will do nothing to stop Monsanto. In fact, his nominee as EPA chief, plans to dismantle the EPA so these toxic chemicals cannot be banned. People and fetuses can die, while Trump and allies help Monsanto spread poisons around the world.

    Susan Snow

  9. As an nurse with over 40 years of experience in the health care industry it has been my observation that healthy folks don’t get c.diff. It’s those patients who have been admitted to the hospital and have multiple areas of concern, CHF, renal failure, pneumonia, stasis ulcers etc; and who are intubated and receiving several strong IV antibiotics for who are at highest risk for c.diff. And as far as MRSA? Diet has nothing to do with prevention. It’s everywhere in the community and a large percentage of health care workers have long been colonized with it. Wash your hands.

    1. This comment is SO wrong. I am young and healthy and I was 24 when I got C Diff. Your health is has absolutely NOTHING to do with your chances of getting C Diff. I took 1 round of antibiotics and BOOM I got a severe case of C Diff that almost killed me. My good health and young age did NOTHING to protect me.

  10. Hackers have eliminated the sound on all of your videos about super bugs contaminating the food supply. I strongly suggest that this is because the Biotechnology Governor of the Year in 2008, Sonny Perdue, is Trump’s nominee for the USDA, which would be a total disaster to our health, even if we eat organic and a plan based diet.

    When one California organic farmer thought they found a irrigation water supply, the Obama USDA let him know that is was contaminated with salmonella, and he told his people, and they looked deeper for cleaner water in an extreme drought, no less. And because Chevron FRACKED California and contaminated their water supply, someone had the wise idea to sell wastewater to organic farmers because they use less water than giant conventional farmers. That wastewater is still going on now, and it is fracking (oil) waste water, which is highly toxic.

    I’m now buying most of my produce from local farmers. And, at the same time, I’m trying to gather information on the Factory Farming former Governor of Georgia, Sonny Perdue, who has been nominated by President Trump to run the USDA. A factory farming USDA chief would be a disaster to health organic farmers and family farmers.

    I believe that the reason Clostridium difficile: Its Potential as a Source of Foodborne Disease is far higher in the USA than in Europe (4.6 to 50% USA vs 0-3% in the E.U. is because Europe has strong regulations, choses to buy from family farmers who care for the livestock and factory farming is just getting started in some parts of the E.U. See: Food and Water Europe, Factory Farms and Industrial Soy.

    We must give our Senators important relative studies which were cited in Dr. Greger’s videos (although the videos have no sound due to hackers. The studies themselves, even in abstract forms are important reasons for stopping this nomination, or saying goodbye to organic crops that are not contaminated with antibiotic resistant organisms which are making people and animals sick.

    Monika Krueger and her team, when studying C. Botulism in dairy cows, also found the pathogenic bacterium in the dust on farms, were the dying cows had lived, and in the feces of the animals, farmers, and their children. Will they, and we die as well, from Glyphosate contaminated GMO soy and corn which is in animal feed. Recall: Monsanto patented Glyphosate (e.g. Roundup, Vision Max and other products) as an antibiotic . Professor Krueger and her team found that glyphosate only killed the susceptible and beneficial bacteria and not the highly pathogenic bacteria, including botulism. Is this the same thing that may be causing increassed cases of C-Dif in livestock and humans in the USA???.

    I wish I had the transcripts tor Dr. Greger’s videos. I can understand Professor Krueger’s studies but many others need Dr. Greger’s translations, which is why they were backed, no doubt.

  11. I got c.difficile from a soft shelled crab meal in Thailand. Feeling your intestinal lining slide out of you in large gobs of slime is scary. And then you have no protective lining. The pain and diarrhoea was bad.

    I bought a vegan wrap one day and wasn’t immediately doubled over in pain, so I bought another. I can’t find anything saying clostridium reacts to meat… but vegan food was good. Or at least “much less bad”. I was a certified meat eater but changed significantly after this. I dabbled in fish and eggs which also had no c.difficile side effects, and helped with the challenge of learning to not eat meat.

    I got rid of it, but a year later it returned. T went again, but … I can feel it. I think it’ll be permanently a minor part of my gut flora… my challenge is to control it.

    My nutritionist says 2 things
    1) I need bone broth to line my gut.
    2) c.difficile loves carbs. And the vegan diet has more carbs than a meat diet.

    I need to resolve this against my positive experience. Any research into what to eat when you’ve already got c.difficile?

    All advice appreciated. I’ll search the site too of course.

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