Correlation of Bacterial Biofilm Grade with Clinical Features in Chronic Rhinosinusitis

Objective: The aim of this study was to determine the presence of bacterial biofilms in chronic rhinosinusitis (CRS) without polyps using scanning electron microscope (SEM) and to investigate whether there was correlation between grade of biofilm formation and clinical features of patients. Methods: This was a prospective observational study with two groups: the first group was composed of 20 CRS patients undergoing endoscopic sinus surgery (ESS) and the control group included 15 patients without CRS, undergoing septoplasty or septorhinoplasty surgery. Clinal data were recorded preoperatively; mucosal samples and culture materials were obtained intraoperatively. Specimens were investigated for detection of biofilms with SEM. A biofilm grading system from grade 0 to 4, according to biofilm prevalence on the surface, was proposed. Symptom score, allergy presence, previous ESS history, Lund-Mackay computed tomography (CT) score and culture results of patients were compared according to biofilm grade. Results: Biofilm formation was found in 16/20 (80%) CRS patients, yet none in 15 controls. Among CRS group, number of patients without biofilms (n=4) was too low to compare CRS patients with and without biofilms with each other, statistically. However, higher biofilm grades (grade 3 and 4) seemed to correlate with previous ESS and culture positivity but not with preoperative symptom score, Lund-Mackay CT score or allergy. Conclusion: A grading system for biofilms is essential and it should be established in order to perceive CRS pathophysiology and find new treatment targets.