Scientists find new antibiotic right under our noses

Researchers in Germany have discovered a bacteria living inside the human nose that produces an antibiotic capable of killing one of the most hard-to-treat pathogens, which causes serious, even deadly skin and wound infections, bloodstream infections and pneumonia.

The researchers picked through nose samples of 187 hospital patients, ultimately isolating a substance called lugdunin, produced by Staphylococcus lugdunensis bacteria which live inside the nose.

S. lugdunensis is present in only about 10 per cent of humans, while staphylococcus aureus is found in about 30 per cent of the population.

“When there is a severe infection it is usually the same strain that the patient or his neighbor or his nurse has been carrying around”, Peschal explains. The organisms simply developed and traded mutations that allowed them to survive assaults from anti-bacterial drugs.

This lugdunin compound acts as an antibiotic, blocking S. aureus bacteria from making their home inside the nose. Moreover, S. aureus did not develop resistance to lugdunin, as it has with other antibiotics, when exposed to sub-lethal amounts over time. Since they are not treatable with the usual methicillin antibiotics, these staph infections are hard to beat, requiring powerful and expensive last-resort antibiotics to kill off the bacteria.

The research from Andreas Peschel and colleagues at the University of Tübingen suggests that the vast variety of microorganisms living in the human body, particularly in the nose, may be a potential source of new antibiotics. “We never found spontaneous mutants”, says Peschel.

S. lugdunesis and S. aureus are naturally exposed to each other, “because these two meet each other in the nose” says Peschel.

German researchers found that this antibacterial substance was effective in treating skin infections in mice caused by staphylococcus aureus bacteria, according to a study published on Wednesday in Nature.

Antibiotic resistance is a growing threat, and some experts worry that some day people may die of what used to be a simple infection. They combined co-occurrence data-the pattern of low S. aureus in noses with S. lugdunensis-with experimental work showing that lugdunin kills infectious bacteria under a number of conditions.

But S. aureus is natural enemies with S. lugdunesis in the nose, and we can use this to our advantage.

The really important contribution of this study is not lugdunin itself, says microbiologist Kim Lewis of Northeastern University, but rather the new approach for finding antibiotic-producing bacteria within our own bodies.

The discovery of lugdunin provides hope for treating antibiotic-resistant bacteria such as MSRA, although the researchers warn that it could still take years to develop a new drug and bring it to market.