Staph infections can be deadly, especially in hospitals where certain strains have evolved to be resistant to antibiotics. The bacteria responsible for these infections, Staphylococcus aureus, is common — one in three people have it hanging out in their nose. It’s mostly harmless, unless it makes its way into a cut or into your bloodstream. And the search is on for new ways to kill the strains that develop antibiotic resistance.

Now biologists at the University of Oregon have found another natural resident of our bodies that can keep staph in check: a type of fungus called Malassezia that we all have on our skin.

Malassezia, which is technically a kind of yeast, survives by consuming the oils produced by our skin. The byproduct of this greasy feast is a fatty acid, which the researchers discovered could inhibit the spread and survival of staph bacteria on human skin samples. They believe the fatty acids break down the outer casing of the bacteria, causing all the innards to leak out. It can stop staph in its tracks.

This image from the National Institutes of Health shows a scanning electron microscope image of methicillin-resistant Staphylococcus aureus bacteria (yellow) and a dead human white blood cell (colored red.) Researchers at the University of Oregon have found a common skin yeast that inhibits the grown of staph bacteria and could unlock new treatments for staph infections.

This image from the National Institutes of Health shows a scanning electron microscope image of methicillin-resistant Staphylococcus aureus bacteria (yellow) and a dead human white blood cell (colored red.) Researchers at the University of Oregon have found a common skin yeast that inhibits the grown of staph bacteria and could unlock new treatments for staph infections.

Courtesy of NIH

But just like staphylococcus bacteria that evolves resistance to antibiotics, it didn’t take long for the staph to develop resistance to the antibacterial fungus. In just 12 runs of the experiment, the staph evolved tolerance to the fatty acid. The researchers then did a genetic analysis to reveal what changed to allow the staph to survive.

The research shows there’s a complex and invisible microbial drama playing out on the surface of our skin. Understanding and harnessing those interactions could eventually lead to new ways of fighting infections and keeping people healthy.

The research is published in the journal Current Biology here.

In these All Science Snapshots, “All Science. No Fiction.” creator Jes Burns features the most interesting, wondrous and hopeful science coming out of the Pacific Northwest.

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