Bacterial biofilm associated with chronic laryngitis.

Objective: To determine the incidence of biofilm on the vocal fold epithelium of patients with chronic laryngitis. Bacteria can grow in biofilm protected by a glycoprotein mass. Recent studies have shown the importance of biofilm in chronic otolaryngologic infections. Because chronic laryngitis is often recurrent and occasionally purulent, we hypothesized that it is biofilm related.

Design: Prospective, controlled, blinded study. Epithelial biopsy specimens from true vocal folds from patients with chronic laryngitis undergoing diagnostic laryngomicroscopy were prepared for confocal scanning laser microscopy (CSLM) and polymerase chain reaction (PCR) microarray: CSLM images were evaluated for bacterial biofilm morphologic characteristics; PCR with microarray-based diagnostic assay was used to identify the bacterial species involved. Patients with vocal fold polyp served as control cases.

Setting: Tertiary care university hospital.

Patients: Eighteen consecutive patients were enrolled in the study. Thirteen of them had chronic laryngitis, and 5 had vocal fold polyps.

Results: In 9 cases, the CSLM revealed bacterial growth in biofilm form, and most of these specimens (8 out of 9) were from patients with chronic laryngitis. The PCR results were positive in 13 cases, including all 9 biofilm-positive cases.

Conclusions: Direct detection of biofilm in laryngeal biopsy specimens from patients with chronic laryngitis supports the hypothesis that chronic laryngitis may be biofilm related. Biofilm was found in 62% of the cases of chronic laryngitis. To our knowledge, this is the first report of bacterial biofilm associated with chronic laryngitis; however, further investigation is warranted before a clear conclusion can be drawn.