Surprise: dreaded superbug MRSA wasn’t created by humans after all

On the hunt for the origin of the superbug, researchers – surprisingly – end up not with our antibiotics, but with… the hedgehog.

MRSA is considered by the World Health Organization to be one of the greatest threats to human health. This is because the superbug is insensitive (resistant) to treatment with the antibiotic methicillin; a commonly used drug. It was long thought that the emergence of our antibiotics was the basis of the origin of the antibiotic-resistant superbug. But according to a new study surprisingly not the case.

Antibiotic resistance

Antibiotics are medicines prescribed by a doctor if you have developed an infection caused by a bacteria. The antibiotic then kills the bacteria, or inhibits its growth. However, more and more bacteria are now becoming resistant to antibiotics, which means that the drug no longer works. This antibiotic resistance has long been considered a modern phenomenon, driven by the clinical use of antibiotics.

Nature

As mentioned, the MRSA bacterium is resistant to the antibiotic methicillin, and can therefore not be killed with it. As a result, the bacteria can cause infections that are difficult to treat and sometimes even fatal. The superbacterium MRSA has been keeping people busy for a long time. Because almost all antibiotics we use today originated in nature, researchers hypothesize that resistance to them probably already exists in nature. In recent years, several animals have been subjected to an inspection. Because does a certain type of MRSA also occur in nature?

hedgehogs

The answer to that is yes. In a new study, scientists examined the swabs from several hedgehogs living in both Europe and New Zealand. And a whopping 60 percent of the hedgehogs surveyed tested positive for a type of MRSA known as mecC-MRSA.

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In addition to the bacterium, the researchers also found a fungus on the skin of these animals. Trichophyton erinacei called. This fungus is known to produce certain chemicals that can kill bacteria; a kind of antibiotic. And then all of a sudden all the puzzle pieces fell into place. Because it could well be that the antibiotic resistance of the MRSA bacteria arose because it lived side by side with the fungus on the skin of the hedgehog.

Origin

The researchers then decided to sequence the genes of the mecC-MRSA found on hedgehogs to reveal their first appearance. “We found that they existed as early as the 1800s,” said researcher Ewan Harrison. MecC-MRSA probably arose about 200 years ago, around 1800, long before the introduction of methicillin in 1959. “So our study shows that the use of penicillin was not the origin of the antibiotic-resistant superbug; it was a natural, biological process,” Harrison explains. “We suspect that MRSA evolved in a struggle for survival on the skin of hedgehogs and then spread to livestock and humans through direct contact.”

Warning

It means that the dreaded superbug MRSA was not created by humans, but predates the use of antibiotics in medical and agricultural settings. Antibiotic resistance can indeed arise in nature. “This study is a clear warning,” said study researcher Mark Holmes. “When we use antibiotics, we have to use them with care. There is a very large ‘reservoir’ in the wild where antibiotic-resistant bacteria can survive. And from there it is a small step to livestock and then to humans.”

According to the researchers, the findings are no reason to be afraid of hedgehogs: people rarely get infections with mecC-MRSA. “In addition, it’s not just hedgehogs that harbor antibiotic-resistant bacteria — all wildlife carries many different types of bacteria, as well as parasites, fungi and viruses,” Holmes said. “Wild animals, livestock and people are all connected: we all share one ecosystem. It is not possible to understand the evolution of antibiotic resistance unless you look at the whole system.”