What role do biofilms play in chronic and recurrent otitis media and otorrhea?
Bottom line: Positive labeling of otorrhea solids for extracellular DNA (eDNA) and integration host factor (IHF), in combination with microbiological culture results, indicated that biofilms likely play a key role in chronic otorrhea. DNABII proteins in association with eDNA, may serve as a key therapeutic target in post-tympanostomy tube otorrhea.
Background: Otitis media with effusion and recurrent acute otitis media are common problems in children. Treatment commonly consists of systemic antibiotics, with surgical tympanostomy tube placement for those resistant to medical treatment; however, tympanostomy tubes and middle ear mucosa represent ideal environments for attachment of bacteria and biofilm growth. Biofilm formation has been investigated as a possible source of chronic otitis media and post-tube insertion otorrhea.
Setting: Department of Otolaryngology–Head and Neck Surgery, Nationwide Children’s Hospital, Columbus, Ohio.
Synopsis: A total of 15 samples were collected and processed for immunofluorescent labeling for the presence of a DNABII protein (e.g., IHF) and counterstained for extracellular DNA (eDNA). Of the 15 total specimens, 11 were culture-positive for bacterial species, with one yielding yeast. In four of 11 specimens that were culture-positive for bacterial species, one of the three predominant otopathogens of otitis media was cultured (e.g., nontypeable Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis). Two additional cultures yielded methicillin-resistant Staphylococcus aureus. The remaining specimens were of mixed microbial origin, while three specimens were culture-negative. Of the 15 samples labeled with rabbit anti-IHFE. coli and counterstained with DAPI, nine were positive for both eDNA and the DNA-binding protein IHF. Sixty percent of all specimens were positive for IHF, and eight of the 11 samples that were positive for microbial growth were also positive for labeling with antibodies directed against the DNABII protein IHF.
Citation: Idicula WK, Jurcisek JA, Cass ND, et al. Identification of biofilms in post-tympanostomy tube otorrhea. Laryngoscope. 2016;126: 1946-1951.