The human nose is packed with bacteria. Some of its inhabitants can sicken us, but yet other nose-dwellers may hold the key to fighting them off. Today, scientists announced the discovery of a new antibiotic produced by bacteria in human noses. Called lugdunin, the compound can combat Methicillin-Resistant Staphylococcus aureus (MRSA). MRSA can cause a potentially life-threatening infection, and is resistant to some antibiotics.