Study: 'Slime' Causes Ear Infections

Being slimed may take on a whole new meaning for children who suffer from chronic middle ear infections.

A new study shows that chronic middle ear infections may be caused by a thin biofilm that coats the middle ear and forms a slime-like barrier that prevents the body's natural defenses from fighting infection-causing bacteria.

"It appears that in many cases recurrent disease stems not from re-infection as was previously thought and which forms the basis for conventional treatment, but from a persistent biofilm," says researcher Garth Ehrlich, Ph.D., executive director of the Allegheny-Singer Research Institute's Center for the Genomic Sciences, in a news release.

Treatment of ear infections normally includes use of antibiotic drugs. But researchers say the results of this study may lead to a new approach in treating chronic middle ear infections.

"Given that bacteria living in biofilms are metabolically resistant to antibiotics, this study makes a definitive, scientifically based statement against the use of these drugs to treat children with chronic ear infections. It simply does not help the child and increases the risk of breeding more resistant strains of bacteria," says Ehrlich.

New Culprit Implicated in Ear Infections

In the study, published in The Journal of the American Medical Association, researchers examined the inside of ears from 26 children having tubes implanted in their ears to treat chronic middle ear infections and compared them with a group of eight patients undergoing other forms of inner ear surgery.

Evidence of the slimy biofilms was found in 92 percent of samples taken from children with chronic ear infection. None of these biofilms was found in the comparison group.

Researchers say the slimy films protect infection-causing bacteria from the body's natural defenses and cause the body to produce a gooey fluid that can become trapped in the ear, which is also resistant to antibiotics.

Although antibiotics may be effective at treating ear infections in children who don't have these biofilms or acute infections, researchers say the results of this study suggest that the drugs won't help children whose chronic middle ear infections are caused by these films. Implanting tubes to aid in drainage of ear fluid and slime may be a better option for these children.

They say future therapies for biofilm-related ear infections may include using good bacteria to prevent the formation of biofilms.

SOURCES:: Hall-Stoodley, L. The Journal of the American Medical Association, July 12, 2006; vol 296: pp 202-211. News release, Medical College of Wisconsin/Allegheny Singer Research Institute.
By Jennifer Warner
Reviewed by Louise Chang, M.D.
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