Nasal Bacteria Reveals Potential MRSA

macro shot of human nose

MRSA is a resistant strain of staph infection and can easily be considered the poster child for hospital-acquired infections. A potential new antibiotic, from nasal bacteria, may be able to successfully kill or outright prevent MRSA infections, offering hope for cutting down on the approximately 20,000 deaths the disease causes each year in the U.S.

The nose is a common entryway for MRSA to get into the body, but about 30% of people already have MRSA in their nose yet they don’t get sick. Although it is possible that the immune system of a healthy person is able to keep the bacteria at bay most of the time, the researchers wondered if there was something else in the nasal microbiome that was contributing.

The Germans sucked out the snot of 37 healthy subjects and cultured the various bacteria found in the samples. S. aureus, the staph strain that causes MRSA, was planted alongside the other snot species and left to grow. As it turned out, it was another staph species, S. lugdunensis, which was killing off the MRSA bacteria. A bit more exploration narrowed the cause down to a compounded called “lugdunin”.

This is where things start getting cool. When given to mice, lugdunin could treat MRSA infections and it even penetrated to the lower layers of the skin—handy for stopping any deeply-rooted infections. Inspired, the researchers picked the noses of 187 hospitalized patients and found that all of the samples either had S. aureus or S. lugdunensis, but not both. Although a relatively small sample, it was enough to suggest the possibility that the presence of one species inhibits the growth of the other.

Incidentally, there is also some thought that S. lugdunensis could work as a probiotic by getting introduced to the noses of patients who are at-risk for catching MRSA. While plausible, the theory does have a few caveats. First, MRSA can get in other ways than the nose so the approach would need testing to see if it is both viable and if it could help enough patients. Second, S. lugdunensis is still a type of staph and can make people sick and those who are most vulnerable to MRSA are the immune-compromised.

Still, even if the probiotic preventative option doesn’t work out, the potential for a new weapon against MRSA still holds promise. The researchers have already filed a patent on lugdunin and are currently looking for a pharmaceutical company to develop it for clinical trials.

Just think, it was under their nose the entire time.

Sorry, couldn’t resist.

Zipperer, A., et. al., “Human commensals producing a novel antibiotic impair pathogen colonization,” Nature, 2016; 1038/nature18634.