So the big question was, why hedgehogs carry so much mecC MRSA?To find out, Larsen went to the library……where I came across an old study from the 1960s which showed that a particular fungus in hedgehogs is able to produce a penicillin-like antibiotic that is very similar to methicillin.So hedgehogs with this particular skin fungus would naturally be exposed to penicillin.And that could have launched an evolutionary arms race that drove the hedgehog’s resident bacteria to evolve resistance.This was a real eureka moment and led us to hypothesize that wild hedgehogs have been a natural reservoir of mecC MRSA long before penicillin and methicillin came on the market.To confirm this suspicion, Larsen and his colleagues screened hedgehogs from Europe and New Zealand and found that hedgehogs in Scandinavia and the UK harbor a heavy load of mecC MRSA.And they also found that the fungus carried by those hedgehogs had all the genes they needed to produce penicillin.We then went on and sequenced and analyzed the genomes of around one thousand mecC MRSA isolates, which showed that they first appeared in hedgehogs in the early 1800s long before we started to use antibiotics in human and veterinary medicine.Now, that doesn’t mean that we should feel free to use antibiotics all over the place, because it’s not our fault, it’s the hedgehogs’.Because if having antibiotics around encourages bacteria to evolve resistance, taking antibiotics away robs them of their superpower and leaves them a little bit weaker than their non-resistant kin.
