A superbug antibiotic… that comes out of our noses?

Nature fearlessly plunges into our nostrils in search of bacteria that can kill MRSA:

The potential new soldier in the fight against MRSA is a molecule called lugdunin produced by the bacterium Staphylococcus lugdunensis, report Andreas Peschel and colleagues at the University of Tübingen, Germany, on 27 July in Nature.

In a sampling of 187 hospital patients, people whose noses naturally contained S. lugdunensis were six times less likely to have S. aureus than people whose noses lacked S. lugdunensis, Peschel’s team found. This suggests that S. lugdunensis is able to combat the growth of the problematic bacterium. That means the antibiotic produced by the bacterium could be developed as a preventive — a nasal spray, for example — to keep S. aureus out of people’s noses in the first place. About 9% of people naturally carry S. lugdunensis.

When Peschel and his team stumbled upon lugdunin, they weren’t looking for a new antibiotic. They were studying S. aureus in its natural environment, the human nose. “If you want to keep the bacteria in check, you need to understand their lifestyle,” he says. “And to understand that, we also looked at its competitors.” They screened 90 bacteria from the human nose, and found that only S. lugdunensis killed MRSA.

When Peschel’s team infected the skin of mice with S. aureus, lugdunin ointment killed the infection both on the surface and in deeper layers of the skin. S. lugdunensis also reduced the amount of S. aureus when squirted into the noses of cotton rats (Sigmodon hispidus).