Biofilms and chronic rhinosinusitis: systematic review of evidence, current concepts and directions for research

Introduction: Chronic rhinosinusitis (CRS) possesses the hallmarks of biofilm mediated disease. This paper represents a systematic review of the published evidence for biofilms as the mediator of the inflammation in CRS. Current concepts on biofilm formation and properties, treatment strategies and directions for research are discussed. Methods: A systematic review of the published literature for biofilms and their role in chronic rhinosinusitis was undertaken. Both Medline (1966-2006) and Embase (1988-2006) were searched until November 2006 which yielded 652 articles, 13 of which provided original research of biofilms in CRS. Results: There were 7 studies demonstrating biofilm morphology in mucosal samples from human CRS patients. One study showed similar evidence for biofilms in an animal model of CRS. FISH techniques with CLSM were employed in one study to demonstrate biofilm,formation in situ by S.pneumoniae, S.aureus, H.influenza and P.aeruginosa. In vitro biofilm forming capacity of microbiological samples, after culture, was assessed in two studies. Correlation with a clinical outcome was also made in these papers. One study demonstrated biofilm growth in removed frontal sinus stents. Conclusions: Biofilms are associated with CRS, however, little research is available to define their role in the pathogenic process. There is tremendous potential for future research. Biofilms may be a significant factor in the inflammatory process.