Evaluation of bacterial biofilms in chronic rhinosinusitis

We investigated the presence of biofilms in patients with chronic rhinosinusitis.

Prospective study.

Thirty patients with chronic rhinosinusitis scheduled for endoscopic sinus surgery were enrolled in this study. Nasal swab cultures were taken at the time of surgery. Samples were cultured using conventional methods for Haemophilus influenzae, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Staphylococcus aureus.

Culture-positive samples were evaluated for slime-forming ability. Qualitative detection of biofilm formation by all slime-producing strains was studied by culturing the strains on Congo red agar plates.

Twenty-three of 30 patients' samples were culture positive (76.6%). Thirteen S. aureus and 10 P. aeruginosa cultures were identified on 23 specimens. Bacterial biofilms were present on 15 of 23 (65.2%) culture-positive specimens. Nine of 13 (69.2%) S. aureus cultures and 6 of 10 (60%) P. aeruginosa cultures produced bacterial biofilms.

This conventional method is capable of demonstrating biofilm-forming ability in bacteria recovered from patients with chronic rhinosinusitis. The biofilm-forming ability was higher in S. aureus compared with P. aeruginosa.