Biofilms and chronic otitis media: an initial exploration into the role of biofilms in the pathogenesis of chronic otitis media ☆ Michael Hoa, MD a , Mausumi Syamal, MS a , Michele A. Schaeffer, BA b , Livjot Sachdeva, MS b , Richard Berk, PhD c , James Coticchia, MD b, ⁎ a Department of Otolaryngology, Wayne State University School of Medicine, Detroit, MI, USA b Division of Pediatric Otolaryngology, Department of Otolaryngology, Wayne State University School of Medicine Detroit, MI, USA c Department of Immunology and Microbiology, Wayne State University School of Medicine Detroit, MI, USA Received 8 December 2008 Abstract Purpose: The aim of the study was to compare the extent of biofilm infection in percentage of mucosal surface area of adenoids removed from children with otitis media with effusion (OME) vs those with recurrent acute otitis media (RAOM) and obstructive sleep apnea (OSA). Materials and methods: Comparative microanatomical investigation of adenoid mucosa using scanning electron microscopy obtained from 30 children with OME, RAOM, and OSA was used in this study. Seventeen males and 13 females ranging in age from 9 months to 10 years were included in this study. Percentage of biofilm surface area involvement was the main measure. Results: Adenoids removed from patients with OME had moderately dense mature biofilms covering the mucosal surface with a mean of 27.7% of their mucosal surface covered with mature biofilms. These results were distinct from results obtained from patients diagnosed with RAOM and OSA with means of 97.6% and 0.10% of their mucosal surfaces covered with mature biofilms, respectively. These differences were statistically significant at P b .0001. Conclusions: Adenoids removed from patients with OME were characterized by distinctly different percentage of biofilm mucosal surface area coverage, with significantly more biofilm presence than OSA patients but significantly less biofilm presence than RAOM patients. Although previous investigations have supported a dominant role of nasopharyngeal biofilms in RAOM pathogenesis, these results suggest nasopharyngeal biofilms may play a different role in the pathogenesis of OME and that this clinical entity may be more multifactorial in nature. © 2010 Elsevier Inc. All rights reserved. 1. Introduction Otitis media is traditionally recognized as an infectious entity caused by Haemophilus influenzae, Streptococcus pneumoniae, or Moraxella catarrhalis. However, otitis media can be further delineated into 2 subcategories— acute otitis media (AOM) and otitis media with effusion (OME). Clinically, the 2 forms of otitis media present quite differently. Although fluid may be present in the middle ear for both, AOM has a rapid onset with symptoms of otalgia, otorrhea, and fever [1]. Conversely, OME patients present with middle ear fluid but show no signs or symptoms of acute infection and can become chronic (COME) if the effusion persists greater than 3 months [2]. Risk factors for both AOM and OME involve eustachian tube dysfunction, crowded living conditions, day care attendance, and impaired immunologic status [3,4]. Moreover, AOM is primarily regarded as a transient infectious entity often with viral coinfection [5]. In contrast, the etiology of otitis media with effusion is hypothesized to be a more protracted but less virulent condition. Initially, OME was thought of as a sterile inflammatory process due to the subsequent inability to Available online at www.sciencedirect.com American Journal of Otolaryngology–Head and Neck Medicine and Surgery 31 (2010) 241 – 245 www.elsevier.com/locate/amjoto ☆ Work supported by Deafness Research Foundation. ⁎ Corresponding author. Division of Pediatric Otolaryngology, Depart- ment of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, 540 East Canfield, 5E-UHC, Detroit, MI 48201, USA. Tel.: +1 313 745 4336; fax: +1 313 577 8555. E-mail address: jcoticch@med.wayne.edu (J. Coticchia). 0196-0709/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.amjoto.2009.02.015