WEDNESDAY, Dec. 11, 2013 (HealthDay News) -- 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. aureusstrains are antibiotic-resistant.

It's been known that S. aureuscan 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. aureuscarriers, another third are occasional carriers and a remaining third don't seem to carry S. aureusat 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. aureusgets sick. When they're out walking the streets and otherwise healthy, attempts to rid them of their S. aureusare 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. aureuscarriage is a major liability," he said.

If S. aureusgets 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 pseudodiphtheriticummay compete with S. aureusat the sites deep within the nose. It's possible that C. pseudodiphtheriticum-- or some molecular product it produces -- may prove useful in countering S. aureusinfections, the researchers said.

The study was published Dec. 11 in the journal Cell Host & Microbe.

More information

The U.S. Centers for Disease Control and Prevention has more about antibiotic-resistant staph infections.