Potentially harmful staph bacteria can lurk deep inside the nose, a small new study finds.
Researchers tested 12 healthy people and found that formerly overlooked sites deep within the nose may be reservoirs for Staphylococcus aureus, which is a major cause of disease. Nearly half of S. aureus strains are antibiotic-resistant.
It's been known that S. aureus can reside on the skin and at sites lower down in the nose. Although there are ways to eliminate the bacteria, it typically returns in weeks or months.
This new finding that the bacteria can be present further inside the nose may explain why this happens, the Stanford University School of Medicine researchers said.
"About one-third of all people are persistent S. aureus carriers, another third are occasional carriers and a remaining third don't seem to carry S. aureus at all," study senior author Dr. David Relman, a professor of medicine and microbiology and immunology, said in a university news release.
"Not everyone who carries S. aureus gets sick. When they're out walking the streets and otherwise healthy, attempts to rid them of their S. aureus are not necessary, and even sometimes futile," said Relman, who also is chief of the infectious disease section at Veterans Affairs Palo Alto Health Care System, in California.
"But once a carrier enters a hospital with an underlying illness or a weakened immune system or a high likelihood of undergoing skin-penetrating procedures, S. aureus carriage is a major liability," he said.
If S. aureus gets into the bloodstream through a wound, incision or catheter placement, it can cause potentially life-threatening problems such as sepsis, pneumonia or infection of heart valves.
Relman and his colleagues also found that a type of bacteria called Corynebacterium pseudodiphtheriticum may compete with S. aureus at the sites deep within the nose. It's possible that C. pseudodiphtheriticum -- or some molecular product it produces -- may prove useful in countering S. aureus infections, the researchers said.
The study was published Dec. 11 in the journal Cell Host & Microbe.