New Research Reveals Why Factory Farms Have Become Superbug Factories–and Why Worse is yet to Come

A band of radicals

A band of radicals

Along with their usual rations of grain and prepared feed, factory-farmed hogs and chickens in the United States also dine on a steady diet of antibiotics. The animals are given the drugs, not to prevent or cure illness, but simply because low-level doses of antibiotics stimulate them to grow faster than untreated animals. This may be good for agribusiness’s bottom lines, but an increasing body of research shows that it might be very bad for public health.

Several scientific examinations of pork and poultry operations in this country have shown that anti-microbial-resistant “superbugs” such as flesh-eating methicilin-resistant Staphylococcus Aureus (MRSA) and certain tough-to-kill strains of E. coli are showing up, not only in farm animals, but in the humans who tend them—and even in members of their families who don’t work on the farms.

Now, a group of researchers at Boston University has discovered a mechanism that causes these superbugs to develop. It could mean that the problem with antibiotic-resistant bacteria is even worse than previously imagined. Their results are reported in the current issue of the journal Molecular Cell.

In earlier studies, the scientists had found that drugs which kill bacteria do so in part by stimulating the production of free radicals in those bacteria—not unlike the ones in humans that contribute to heart disease, cancer, and other maladies. However, when antibiotics are administered to the bacteria at low levels, as they are on factory farms, instead of killing the bugs, the free radicals cause genetic mutations—far more than would normally occur. Some of those mutations lead to new strains of bacteria that can survive what were once-lethal doses of drugs.

“Our work indicates that it is much more dangerous than previously thought,” said Jim Collins, a professor of biomedical engineering and one of the paper’s authors. “The low-level antibiotics are boosting up the mutation rate and not killing off the bacteria. As result, you have created a zoo of mutants.”

Before the Boston study, scientists generally viewed the mutations that led to resistance as chance events. “A mutation would emerge randomly in a bacterial population, and the antibiotic would kill off everybody but that guy, and that guy would breed, creating a resistant strain,” Collins said. “We now know that the antibiotics are acting as mutagens themselves.”

But it even gets scarier. The brave new bugs that result from these mutations can carry resistance not only to the antibiotic that had been administered, but to others as well and even to multiple antibiotics. “You could have antibiotic A being delivered to the bacteria and have a mutant bug arise that could still be killed by high levels of antibiotic A, but now has mutations that give it resistance to antibiotic B, antibiotic C, and antibiotic D,” said Collins.

There is a simple solution to agriculture’s contribution to this problem: Outlaw the use of subtherapeutic antibiotics on farm animals. The European Union did it in 2006. Somehow they still manage to produce hogs and chickens there. So a ban here is hardly what I’d call a radical idea.

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  1. Jacqueline says:

    I guess the pharmaceutical lobby is not as strong in Europe. I think it’s something like 70 or 80% of the antibiotics produced here are utilized in agriculture, not for human consumption. That’s a lot of subtherapeutic mutant bug spawning going on. Having seen MRSA (methicyllin resistant stappholoccocus aureus) do a number on my cancer stricken father-in-law, I can tell you it is something to be seriously frightened of. Lucky for us, he recovered.

    The European example is one we should recall more often. It CAN be done.

  2. Dyan Nash says:

    Hopefully if enough of these articles get out there the public will pay attention, or at least the information may trickle down eventually to the lovers of KFC and triple burger with bacon and cheese eaters who may give up one patty and a slice of cheese to be healthier, and the animals may eventually be spared as well.

  3. Paul VH says:

    Speaking as a Food Scientist by trade; the same ill logic could be taken to the human population…we use anitbiotics & flu shots to help stop disease and over several generations the human population had steadily grown in size/stature..this is due in part of the fact that by staving off infections the body can grow/proliferate without using it’s resources to constantly fight off infections. Also of interest is the fact that staph is located just about everywhere, and E coli is easily found in soil. Humans are great carriers of both staph and E coli – no mention of that in the article froma what I can see. No mention is made of all the antibacterial soaps used by people who are becoming germaphobes and that this also contributes to the super bugs. Keep in mind that the natural flora and fauna of the earth has vast amounts of less potent germs – which are easily killed off with antibiotics and soaps, etc – so eliminate those mass quantities of the germs that are easily killed off and what you are left with is the minority of the germs, which happens to be the super bugs. I grant the author that mutations are occuring, however mutations are constantly occuring – whether they are induced by antibiotics or not, the mutations will natually continue to occur. I agree that you still can produce animals without the use of antibiotics like they have in Europe. Once again there is no mention of how healthy, what the size is, what the attrition rate is for animals produced without antibiotic aid. Amazing that we would so readily think of not using antibiotics on the animals, but yet we constantly use them on us, the human population ourselves without much thought to it so that we can continue to grow, live, repopulate.

  4. Pat Gardiner says:

    I have spent almost a decade on this disaster, day after day: there at the beginning, with pigs and in pig country when the horror story started

    There is little doubt that MRSA in pigs has been leaking into the hospitals for some years.

    There was a nasty mutation to a porcine circovirus in Britain in 1999 which caused an epidemic that required huge quantities of antibiotics to handle the consequences.

    MRSA in pigs was the result, usually the ST398 strain.

    The Dutch picked up the problem more than 6 years ago and commendably made everything they knew public.

    Both circovirus and MRSA epidemics have now travelled the world along with accompanying cover-ups. It is quite a nasty situation – now coming to light in the USA.

    MRSA st398, mutated circovirus and various other unpleasant zoonotic diseases have now reached American pig farms.

    The people exposing the scandal in the US are to be commended.

    In Britain they are still trying to cover up MRSA in pigs.

    Pat Gardiner

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