Breakthrough Of The Week: MRSA-Fighting Antibiotic Discovered In Human Nose

Nothing to sneeze at.

Around the world, scientists are constantly working to discover things about the world around them and have a greater understanding of the Universe and our place in it. Every Friday, we'll celebrate that feature a new discovery as our Breakthrough Of The Week.
Around the world, scientists are constantly working to discover things about the world around them and have a greater understanding of the Universe and our place in it. Every Friday, we'll celebrate that feature a new discovery as our Breakthrough Of The Week. Unlocking the secrets of the Universe, one week at a time.

Antibiotics have saved countless lives since they became available commercially in the 1940s, but during that same time, bacteria have been evolving defenses to resist them, making the drugs less effective. To avoid entering a post-antibiotic era, researchers need to stay one step ahead of "superbugs" and find new treatments to beat them. Researchers have now identified a potential source of antibiotics to kill these drug-resistant strains: the human nose.

MRSA (Methicillin-resistant Staphylococcus aureus) is one of the most devastating strains of antibiotic-resistant bacteria, killing over 11,000 people in the US alone each year. Not all strains of S. aureus are such bad news, as many people have it in their nose without any harmful effects. Still, when researchers discovered a different naturally-occurring bacteria that produces a chemical to kill it, they got excited at the potential for a powerful new treatment.

The discovery was made after taking nasal swabs of 187 patients in the hospital and identifying the bacteria. Believe it or not, the nose isn't a huge haven for bacteria. While many microbes use the nose to enter the body, very few actually make their home there which makes them very interesting to researchers.

Methicillin-resistant Staphylococcus aureus (MRSA)
Methicillin-resistant Staphylococcus aureus (MRSA) Shutterstock

The results, published in Nature, found that about a third of the patients had S. aureus in their nose, which is pretty much what they expected to see. Seventeen of the patients—only 9 percent—harbored bacteria called S. lugdunensis. Upon further investigation, they found that S. lugdunensis creates a chemical to kill S. aureus as a form of protection. 

In the lab, the chemical was dubbed lugdunin and efforts to create it synthetically were successful. Mice who were infected with S. aureus saw dramatic improvement or even total clearing of the infection. Lugdunin was also effective against MRSA and other drug-resistant bacteria. The researchers aren't exactly sure yet how lugdunin kills bacteria, but it does an incredibly thorough job with one huge added bonus: the bacteria didn't evolve a resistance.

For 30 days, the researchers exposed S. aureus to levels of lugdunin that were too low to kill it, but high enough to start evolving a resistance. This might not sound like a long time, but it only takes S. aureus 28 minutes to reproduce itself. After a month, that equals over 1540 generations. For some perspective, that many generations would take humans back more than 30,000 years, long before light skin and the ability to digest dairy evolved.

Of course, there is a lot more work to do in making sure that this new compound would be safe for humans to use. S. lugdunensis itself can cause severe infections and there isn't a lot of information about how it would interact with the natural microbiome in our bodies that serve a number of purposes. Still, it will be very exciting to see where this research goes in the future.

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Cover image: Shutterstock