Bacterial biofilms in chronic rhinosinusitis; distribution and prevalence.

CONCLUSION: Biofilms were more prevalent in patients with CRSwNP compared to both CRSsNP and controls, and also on the ethmoid bulla compared to the middle turbinate, supporting a biofilm-related pathogenesis of CRSwNP.

OBJECTIVE: To investigate the prevalence of biofilms in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) compared to patients with chronic rhinosinusitis without nasal polyps (CRSsNP) and controls. To examine the prevalence of biofilms in different anatomical localizations.

STUDY DESIGN: Cross-sectional.

METHODS: This study comprised 27 patients with CRSsNP, 34 patients with CRSwNP, and 25 controls. Biopsies from the middle turbinate, the uncinate process, and the ethmoid bulla were harvested pre-operatively, snap frozen in isopentane, cooled, and stored at -80°C. Prepared with Invitrogens' Baclight LiveDead kit and investigated with confocal scanning laser microscopy.

RESULTS: Biofilms were studied in 33/34 (97%) CRSwNP, 22/27 (82%) CRSsNP, and 14/25 (56%) controls. The difference in point prevalence between patients with CRSwNP vs CRSsNP (p = 0.042, χ(2) = 4.12), CRSwNP vs Controls (p < 0.001, χ(2) = 15.0), and CRSsNP vs controls (p = 0.047, χ(2) = 3.96) were all significant. Biofilms were found in 43/54 (80%) ethmoid bulla, 39/55 (71%) uncinate process, and 31/50 (62%) middle turbinate. The difference between the ethmoid bulla and the middle turbinate locations (p = 0.047, χ(2) = 3.93) was significant.