MRSA-killing antibiotic produced by bacteria in the nose

TüBINGEN, Germany, July 27 (UPI) -- Researchers in Germany found a previously unknown antibiotic in the last place anybody expected it to be: the human nose.

The bacteria Staphylococcus lugdunensis, commonly found in the nose, produces an antibiotic that researchers at the University of Tübingen found kills the dangerous pathogen methicillin-resistant Staphylococcus aureus, also known as MRSA.

MRSA typically infects people in hospitals, nursing homes and other medical settings who have other health conditions that weaken the immune system. The bacteria has become resistant to most antibiotics, including those used to treat other staph infections, and kills about 20,000 people per year.

Researchers have been searching for effective ways to treat MRSA infections -- including recent research suggesting a combination of antibiotics, the breast cancer drug tamoxifen and a pair of synthetic compounds all may do the trick -- but nothing has been proven in trials yet.

Without a drug doctors know will work against MRSA, and antibiotic resistance continuing to increase, researchers are starting to look in new and different places for the next bacteria killer.

"There are estimates which suggests that more people will die from resistant bacteria in the coming decades than cancer," Dr. Bernhard Krismer, a researcher at the University of Tübingen, said in a press release.

For the study, published in the journal Nature, researchers took nasal mucus from 37 healthy people, culturing the bacteria from each participant with MRSA to see what happened.

In the tests, they found a compound in Staphylococcus lugdunensis, called lugdunin, kept MRSA from growing. The researchers then found they could clear staph infections in mice, reporting lugdunin "penetrated the tissue and also acted in the deeper layers of skin," fully clearing the difficult infection, according to STAT.

Further analysis of mucus from 187 hospital patients revealed nearly all were colonized by one of the two Staphylococcus strains, but just one had both. This, the researchers say, suggests an explanation for why some people are susceptible to MRSA infections and some are not.

Although it was effective in lab dishes and mice, the researchers say more work must be done to determine if lugdunin could be used for treatment, or even to prevent patients at risk of an infection from acquiring one.

"Normally antibiotics are formed only by soil bacteria and fungi," said Andreas Peschel, a professor at the University of Tübingen. "The notion that human microflora may also be a source of antimicrobial agents is a new discovery."