None of us knew it (in fact, we did not even suspect it) but for more than 200 years there has been a battle with blood and fire that has as a battlefield the skin of hedgehogs. Yes, the hedgehogs. There, a fungus and a bacterium are engulfed in a bacterium that led the former to secrete antibiotics and, as a consequence, the latter to develop resistance to those antibiotics.
It seems a curiosity, but in reality this simple discovery from the University of Cambridge is a missile on the waterline of much of what we thought we knew about superbugs. What’s more, it leads us to ask ourselves once again how we face one of the greatest challenges of the century: the fact that we are running out of antibiotics.
A new battlefront
“The misuse of penicillin, with doses that are too high, could make microbes resistant and thus reverse its benefits,” said Alexander Fleming in his Nobel speech. That was 15 years after penicillin was discovered and, ever since, that has been the general idea: that the use of antibiotics in humans and livestock has been the culprit for the emergence of resistance.
There are good reasons to believe this and, in fact, as far as we know, the indiscriminate use of antibiotics is the main culprit. So when researchers found that up to 60% of all hedgehogs in Denmark and Sweden had a particular type of “Staphylococcus aureus methicillin resistant “(called mecC-MRSA) caught their attention. How did it end up there? How was it that they had ended up distributed throughout most of Europe and even New Zealand?
After sequencing more than 1,000 strains of the bacteria, they discovered that, against all odds, what best explained initial onset of resistance was not penicillin exposure but the coexistence of S. aureus and the mushroom Trichophyton erinacei (capable, as I said, of producing its own antibiotics) on the skin of those hedgehogs.
The impact of mecC-MRSA on human health is relative. It causes about one in 200 MRSA infections. However, the discovery opens a new battlefront in the war against resistance and will force us to reeexamine many of our ideas about current resistant bacterial strains. But, fundamentally, it confronts us with our strategies to combat them because, if some of the lineages that we know have a natural origin, the rational use of antibiotics is necessary, but not sufficient. You have to go further and you have to do it quickly.
Image | Sierra Nicole