Staph bacteria battle deep within the nose.

• Position: Infections

Formerly overlooked sites deep inside the nose may be reservoirs for Staphylococcus aureus, a major bacterial cause of disease, according to a study by Stanford University, Palo Alto, Calif.

The investigators further found an inverse relationship between the presence of S. aureus at these sites and that of a different bacterial species, Corynebacterium pseudodiphtheriticum, suggesting that the two organisms compete with each other and that C. pseudodiphtheriticum--or some molecular product it excretes --may prove useful in countering S. aureus infections.

"About one-third of all people are persistent S. aureus carders, another third are occasional carriers, and a remaining third don't seem to carry S. aureus at all," says senior author David Relman, professor of medicine and of microbiology and immunology, as well as chief of the infectious disease section at Veterans Affairs Palo Alto Health Care System. "The nose has been long known to be a primary reservoir of S. aureus."

Rigorous and somewhat tedious regimens for eliminating S. aureus do exist, but it typically is a matter of weeks or months before the bacteria repopulate those who are susceptible. The study offers a possible reason why this is so.

The scientists recruited healthy subjects and took samples from three specific areas. The first location was the anterior naris, a relatively dry skin-like patch of tissue located near the nostril. The second was the middle meatus--a warmer, wetter, mucus-producing fold found about midway up the nasal...