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Apocalypse Pig Redux: Last-Resort Resistance in Europe

Colistin resistance is being found on retail meat.
Colistin resistance is being found on retail meat.
Photograph by Joe Benjamin (CC) on Flickr

Here’s a breaking news follow-up to my recent post on the discovery of resistance to colistin, the truly last last-resort antibiotic, in animals, meat and people in China. A research collaboration shared between George Washington University and the Statens Serum Institute and National Food Institute in Denmark is announcing today that they have found that same resistance factor in stored bacterial samples dating back as far as 2012.

Short version: That resistance to the very last-ditch antibiotic is already spreading globally.

The Antibiotic Resistance Action Center in the Milken Institute School of Public Health at GWU, headed by Lance Price, PhD, says in an emailed statement:

The news that the dangerous colistin resistance gene has been found in Denmark is alarming. This newly identified gene, called MCR-1, is on a mobile piece of DNA that can make copies of itself and then jump to from bacterium to bacterium, spreading resistance. History shows that these mobile resistance genes can spread around the world quickly, silently riding in people, animals, and food. The news that MCR-1 has been discovered in Denmark suggests that this scenario is playing out in real time.

In their own statement, the Danish researchers say that when they learned of the new resistance factor (published in Lancet Infectious Diseases on Nov. 16), they quickly went back through the stored genomes of bacteria held at their institutions to look for it:

The approximately 3,000 Gram-negative (E. coli or Salmonella) bacteria, which have previously been mapped using whole genome sequencing, have been reexamined to see whether MCR-1 is present. Results show that MCR-1 was found in one patient, who suffered from a blood infection in 2015 and in five food samples that have been imported from 2012-2014. All the bacteria are multiresistant ESBL bacteria containing the MCR-1 gene, which can further complicate treatment.

I’ll add here that the initial article announcing MCR-1 said that this last-ditch resistance might already have spread to Malaysia. After reading that, the pseudonymous blogger Mike the Mad Biologist did a similar search and uncovered that it may have been recorded as early as 2011 in Portugal. (He adds via Twitter that it is not clear where that isolate originated; Portugal is where it was sequenced.)

There’s resonance in this with the initial discovery of NDM in 2008. That was the previous international superbug of concern, which took out the group of antibiotics called carbapenems and left colistin, a toxic drug preserved from the 1950s, as the only one that works. NDM’s source is India, but it was first discovered in a hospitalized man in Sweden.

There will be more to say about this, but for now, here’s how the GWU group end their statement. (I’ll add a link when they publish it. Here it is.)

We must act swiftly to contain the spread of colistin-resistant bacteria, or we will face increasing numbers of untreatable infections. Leaders from every nation should immediately implement a ban on the use of colistin in animal agriculture. While China appears to be the biggest user of the drug, it is approved for use in the the European Union and many other countries. It also is approved for use in food animals in the U.S., but drug companies holding those approvals are not actively marketing the drugs. Drug companies with these approvals should immediately withdraw these label claims to ensure that colistin is never used in U.S. animal agriculture, otherwise our livestock production facilities could become breeding grounds for untreatable superbugs.

In addition, we need to remember why colistin is the last drug available for treating these dangerous infections. We turned to it because the preferred drug class – carbapenems – became powerless against some superbugs due to overuse. Carbapenems are still effective against many bacteria, but for how long? While carbapenems are not approved for use in animal agriculture in many parts of the world, their use is not explicitly banned. World leaders should call for an immediate ban on carbapenems to protect them for future generations.

5 thoughts on “Apocalypse Pig Redux: Last-Resort Resistance in Europe

  1. Genie is very definitely out of the bottle now and no putting it back in.

    Unfortunately, ceasing use of colistin is no guarantee that the incidence of the plasmid will decrease. The underlying hypothesis here is that in the absence of selective pressure, replicating the plasmid is just a cost to the bacterium and thus will be lost over time. This particular plasmid codes for a virulence factor (type IV pilus) that will provide a positive advantage to bacteria able to take advantage of it. Not only this but there are three different plasmid stability systems (of two different types) that contribute to stable inheritance in the absence of any selection pressure at all.

    I’m not suggesting that it’s pointless to restrict colistin use, rather that this is a classic example of a problem that is best solved by never getting into it in the first place. Maybe there’s a lesson to be learned here for antibiotic use in general, especially if we ever manage to discover a new class of antibiotics.

    At this point we can only really live in hope.

    MM: Tim, I appreciate your contribution, thank you!

  2. Hate to be a grammar nazi, but the opening paragraph stated that this virus was found in pigs, pork, and people. Uh, I know I’m a history major, but I’m also an old country boy. Hate to tell these geniuses this, but the last time I checked pigs are pork. This is a problem that has been known about for decades. Not this particular strain, but the dangers of using antibiotics on animals. Unfortunately, the old christian (no, I’m not religious) maxim is still true: The love of money is the root of all evil. Great job money grubbers and science sellouts, you’ve now possibly ruined southern cuisine. A pox on you all! As an aside, garlic is still a magnificent antibiotic. I’ve personally used it to cure a near fatal case of MRSA. Maybe one day scientists will pull their heads out of their asses and realize that isolating single compounds is not the solution. Just because they aren’t smart enough to figure multiple compounds, doesn’t mean their single compound solution is smart.

    1. Jim,

      Is a steak the same thing as a cow? No, of course not. The author meant that this particular strain (of bacteria!!!) is found in living pigs, pig meat (pork), and people.

      Also, while we appreciate your implication that you are smarter than scientists (who are as of yet unable to “pull their heads out of their asses”), as well as your n=1 study on the effectiveness of garlic, this article relates to bacteria, not viruses.

      It’s ignorance from people like you that have allowed resistant pathogens to grow into the public heath nightmare that they are today, not the inability of scientists to isolate multiple compounds (whatever that means, anyway).

      1. Steak is a cut of beef. Pork is all pig meat. Which means that a pig is pork, while a steak is not a cow. They would have been correct had they sausage, but they didn’t. If you’re going to be a dipshit grammar nazi, at least pull your pinhead out of your ass. I didn’t read the rest of your comment as I hate nazis! 🙂

      2. Actually, just read the rest of your ignorant arrogant bullshit. Yes, I am smarter than you idiots who merely sat on their asses in college and had their parents buy their tuition. That meets most of the requirements of becoming a scientist in this corporate science world. You however, are obviously too stupid to realize this. For over twenty years, regular people have been told they are idiots by scientists for being concerned about all the antibiotics used in farm animals. I can see now why you can’t remove your head from your ass, it’s been there so long it has bonded with your sphincter. You should rename yourself to centipedebiotch.

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