By Michelle Mukonyora
27 July 2016
The past couple of decades have seen scientists scrambling to discover new antibiotics. Antibiotic resistance accounts for an estimated 700,000 deaths worldwide per year. If there had been bets put out as to where a new antibiotic would have come from, the human nose would have been the least likely place. Scientists at the University of Tübingen in Germany have discovered a new antibiotic that may be the long awaited weapon in the war against methicillin-resistant Staphylococcus aureus (MRSA).
MRSA is a deadly strain of an otherwise harmless bacterium S. aureus that is found naturally on our skin, in our respiratory tracts, and in our noses. It is only when S. aureus enters our bloodstream, that it becomes a problem. MRSA is resistant to a host of antibiotics, and its infections are largely associated with hospital stays. MRSA is important in African health management because it is also associated with HIV infections.
The new antibiotic molecule, which is called lugdunin is produced by a relative of MRSA, another bacterium called Staphylococcus lugdunensis. Andreas Peschel and his colleagues sampled the noses of 187 hospital patients. They noted that those patients that naturally had S. lugdunensis in their noses were six times less likely to have S. aureus, when compared to those without S. lugdunensis.
Antibiotics are small molecules that act by interfering with the natural activity of important proteins involved in the life cycle of sensitive bacteria. Lugdunin is unique in that it is larger than other known antibiotics, and it attacks the bacteria’s cell membrane. Furthermore, lugdunin is special because the only other antibiotic to have been found on the human body was lactocillin. Lactocillin is the product of a vaginal bacterium. So far the activity of lugdunin has only been tested in mice.