Slime-Like Substance Blamed for Chronic Ear Infections
Bacterial biofilm resistant to antibiotics, study finds
TUESDAY, July 11, 2006 (HealthDay News) -- If your young child has an ear infection that won't go away, he may be struggling with a slime-like substance in the middle ear that experts call bacterial "biofilm."
This biofilm makes it harder for antibiotics to do their jobs, leading to long-lasting ailments. Bacteria appear to be hiding in this usually protective slimy film in kids with chronic middle ear infections, a new study found.
The discovery isn't going to lead to any new treatments right away, but they may eventually help doctors get a better handle on one of the plagues of childhood. Ear infections, in fact, are the most common illnesses that bring children to doctors.
"It's a particularly big disadvantage to working moms," said study co-author Dr. J. Christopher Post, director of pediatric otolaryngology at Allegheny General Hospital, in Pittsburgh. "It really compromises a woman's ability to participate in the workforce."
Ear infections are so common in kids -- affecting eight or nine of every 10 children -- because the developing middle ear sometimes cannot fully drain fluid, said Dr. Craig Derkay, a professor of otolaryngology and pediatrics at Eastern Virginia Medical School, in Norfolk. Also, the immune system in a child isn't fully developed and can't tackle infections, he added.
Over-prescribing of antibiotics, meanwhile, has made matters worse by helping ear-infection germs develop immunity to existing drugs, he said.
Post and his colleagues in Pittsburgh and Wisconsin studied mucosal tissue from the middle ears of 50 children with chronic ear infections. Some of the children got ear infections repeatedly, while others continually suffered from fluid in their ears.
All the children were scheduled to undergo operations to install drainage tubes in their ears.
The researchers found evidence of mucosal biofilms in 46 of the 50 children. They didn't find any biofilms in another group of eight healthy children and adults whose ears were studied as they underwent cochlear implant operations for hearing loss.
The findings are published in the July 12 issue of the Journal of the American Medical Association.
Biofilms are very common in nature, Post said, such as the slime you might find on rocks next to a pond. "It's like a little city of bacteria," he said, in which germs communicate with each other and are well-protected against the outside world.
The new research suggests that treating chronic ear infections with antibiotics is "not helpful," Post said, adding that "biofilms by their nature are very resistant to antibiotics."
Instead, researchers must find another approach that either gets rid of biofilms or stunts their growth, perhaps by flooding the ear with "good bacteria," Post said. That approach is known as probiotics.
For now, the research is "just sort of an explanation as to why not all children are responding to these antibiotics" and need to have drainage tubes put in, said Derkay.
Learn more about ear infections from the U.S. National Institute on Deafness and other Communication Disorders.