Biofilms in Otolaryngology: Relation to clinical disease needs more study, experts say

San Francisco, Calif.—It is now well recognized that pathogens found in biofilms play a role in many mucosal-based otolaryngologic-related infections, but what that role is and how to prevent or treat biofilms remain unknown, concluded a panel of experts convened here on Sept. 17 at the 2011 American Academy of Otolaryngology-Head and Neck Surgery Annual Meeting.

Emphasizing that a great deal of basic research has now shown the presence of biofilms in areas of the body related to otolaryngologic diseases, David Darrow, MD, DDS, a pediatric otolaryngologist at Eastern Virginia Medical School, Norfolk, Va., said that the task now is to translate that research to the clinic. “The question is, does a biofilm cause a clinical disease,” he said.

Chronic Rhinosinusitis

Although multiple studies have shown that biofilms exist in normal mucosa as well as infected sinuses, and although there are now good tools for detecting biofilms, one of the big unknowns is the point at which a biofilm becomes problematic, according to Joseph K. Han, MD, associate professor and director of allergy, rhinology and endoscopic sinus and skull base surgery at Eastern Virginia Medical School in Norfolk, Va.

“Despite a decade of research on biofilm and sinusitis, we still don’t know when a biofilm becomes pathogenic,” he said, adding that the basic science supports the fact that biofilm in chronic rhinosinusitis (CRS) can cause mucosal injury when the bacteria in the biofilm bind to the epithelium and destroy it through local inflammation.

Whether or not this injury is caused by the amount of biofilm or by the type of organism found on the biofilm is not known. “My personal thought is that the organism and the quantity of the organism allows the biofilm to become pathogenic,” he said.

Dr. Han also addressed the issue of treatment, including the use of topical antibiotics, mechanical disruption and topical surfactant to treat the bacteria on the biofilms directly. Other treatment options may involve treatment of the inflammation, which would not eradicate the biofilm but would decrease the inflammation. He emphasized that a single modal therapy will most likely not be effective to treat biofilms in patients with CRS and that most will need multi-modality treatment that includes high-dose topical antibiotics with a surfactant after mechanical disruption such as endoscopic sinus surgery or hydrodynamic shearing of the biofilm in the sinuses.