Bacterial Competition in the Nose

Epidemiologic studies have consistently shown that although Staphylococcus aureus typically colonizes the human nares, it is not found there universally. Why S. aureus is not always present has not been clear, but German researchers have now found that a second human commensal, Staphylococcus lugdunensis, is a likely to be one factor affecting the colonization rate.

The investigators initially screened a variety of nasal Staphylococcus species for inhibitory activity towards S. aureus and found that an S. lugdunensis strain produced an antimicrobial factor that prevented S. aureus growth. Further work found that the factor was a novel cyclic peptide antibiotic, lugdunin, that has activity against a wide variety of gram-positive bacteria incl…