Potentially powerful antibiotic is lying just beneath our feet

14 Feb 2018

Image: Michal Kowalski/Shutterstock

The hunt for a new antibiotic candidate has been exhaustive, but the answer could be just beneath our feet in the form of soil.

The first antibiotic may have been discovered by accident when Alexander Fleming accidentally left his petri dish near an open window, but such luck has not been shared among modern scientists.

Today, a seemingly impending ‘antibiotic apocalypse’ is on the horizon where even the most common infections are becoming untreatable, yet only two new antibiotic candidates have been identified in the past 70 years.

But now, in a paper published to Nature Microbiology, Rockefeller University researcher Sean Brady reported the discovery of a whole new class of antibiotic obtained from an unknown microorganism found in common soil.

Called malacidins, the new class of antibiotic is capable of killing many types of superbugs, including Staphylococcus aureus (MRSA), often prevalent in hospitals and places where infection can spread easily.

According to The Washington Post, the breakthrough was achieved by a process of cloning significant quantities of DNA from hundreds of soil samples obtained from across the US, sent in by a team of eager citizen scientists.

Sifting through the vast quantity of data, Brady and his fellow researchers were on the hunt for a particular gene closely associated with the production of calcium-dependent antibiotics that attack bacterial cells when calcium is present.

This particular type of calcium-dependent gene is popular among microbiologists because it is believed it could be a great indicator for a much longer sequence controlling the production of antibiotics.

10,000 bacteria beneath your feet

When the gene was identified and cloned, the team placed it into a microbe, which, when cultured, was capable of producing malacidins.

During tests with lab rats, malacidins placed on infected wounds became sterilised and showed no sign of resistance during a period of three weeks after application.

Of course, with such initial success, Brady’s plan is to figure out how to scale it to eventually become a usable antibiotic.

However, in the meantime, he and his fellow researchers are going to continue sifting through the dirt to find more.

“Every place you step, there’s 10,000 bacteria, most of which we’ve never seen,” he said. “Our idea is, there’s this reservoir of antibiotics out in the environment we haven’t accessed yet.

“Most of what’s there is completely unknown, and that’s the future.”

Colm Gorey was a senior journalist with Silicon Republic