Mounting Evidence Supports Role of Bacterial Biofilms in Chronic Infections of Middle Ear and Sinuses

This phenomenon may explain why chronic sinus and ear infections seem to respond to antibiotics and then recur again after the antibiotics are stopped, he added.

For Dr. Desrosiers, this altered phenotype of biofilms that allows bacteria to persist despite antibiotic use does not suggest that antibiotics are not needed. He emphasized the continual need for antibiotics when bacteria flare up and infection sets in, but stressed that ongoing or recurrent infections may be prevented if biofilms are eradicated.

This does not lead to less use of antibiotics, he said. At this point in time, it [biofilms] just gives us another piece of the puzzle. In terms of what it means for the patient today, it means nothing.

What the current data do support, however, is the efficacy of ventilation (tubes) or mechanical debridement (such as teeth brushing) to eradicate chronic infection. Biofilms explain why chronic middle-ear infections are so refractory to antimicrobial usage and why tubes are effective, said Dr. Post.

According to Dr. Desrosiers, tubes change the niche that the biofilm occupies by allowing oxygen to enter the middle ear and changing the local environment where biofilms exist and subsequently clearing up inner ear disease.

But if a causal relationship between biofilms and chronic infection can be made, prevention of biofilms and not eradication is suggested as the best way to reduce ongoing and recurrent infection and the frequency and amount of antibiotics used.

Martin Desrosiers, MD

For Dr. Post, development of a probiotic approach may be the way to go to manage these chronic conditions where we populate the patient with innocuous bacteria that prevent the formation of pathogenic bacterial biofilms.

Other approaches needing further investigation may be through the use of lactoferrin and furanones, according to Dr. Chole. Lactoferrin is a protein in the body that helps defend against bacteria by trapping iron, which is a critical nutrient for bacteria. Furanones are chemicals that protect against bacteria in marine algae.

Until further evidence supports a causal link between biofilms and chronic infection, however, antibiotic use will remain the mainstay of treatment for ongoing and recurrent infections. However, as more data accumulate that demonstrate the presence of biofilms in chronic sinus and middle ear infections, a new therapeutic target aimed at prevention may eventually allow for a reduction in the use of antibiotics.

In the next two to three years you will see radical changes in the way we manage diseases, said Dr. Desrosiers. Once we do find effective strategies for dealing with biofilms, we will have a reduction in the quantity of antibiotics used.