Milwauke ? A recent study found that chronic ear infections are caused by colonies of bacteria that form slimelike barriers that are resistant to antibiotic treatment. The findings explain why some children don’t respond to standard treatment, and suggest that doctors may need to rethink how they treat some children with the condition.

“For kids with bad ear infections, frequent, stronger and more antibiotics is not the answer,” said Richard Rosenfeld, a spokesman for the American Academy of Pediatrics and director of pediatric otolaryngology at the Long Island College Hospital in Brooklyn, N.Y.

“The answer for these kids is likely ear tubes,” he said.

During this surgery, small tubes are placed in the eardrums to relieve pressure in the middle ear. The outpatient procedure takes less than 15 minutes and is done under light anesthesia.

Children with ear tubes still will get ear infections, but they can be treated more effectively with antibiotics delivered through the tubes in a concentration that is 1,000 times stronger than oral medications, Rosenfeld said.