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Published on: January 20, 2011
Identification of biofilms in post-tympanostomy tube otorrhea
Winslo K Idicula1,2, Joseph A Jurcisek3, Nathan D Cass4
1Department of Otolaryngology-Head and Neck Surgery, Wexner Medical Center at The Ohio State University.
Objectives/Hypothesis:
Otitis media is a common problem in the pediatric population. Despite antibiotic therapy, post-tympanostomy otorrhea can be difficult to treat. Biofilms have been shown to play a role in chronic and recurrent otitis media and are implicated in otorrhea. This study investigated both the microbial composition and the presence of biofilm fragments rich in extracellular DNA (eDNA) and the bacterial DNA-binding protein, integration host factor (IHF), in post-tympanostomy tube otorrhea.
Study Design:
Clinical samples.
Methods:
Institutional review board approval was obtained, and samples were recovered from pediatric patients with tympanostomy tubes and persistent otorrhea for both microbial culture and biofilm analysis. For biofilm assessment, frozen samples were sectioned and then labeled using a rabbit anti-IHF, which was detected with goat anti-rabbit IgG conjugated to AlexaFluor 594. Samples were then counterstained with 4',6-diamidino-2-phenylindole (DAPI) to detect DNA, and images were captured by inverted light microscopy.
Results:
Of 15 pediatric otorrhea samples analyzed, nine (60%) contained solids that were positive for labeling of IHF in association with a lattice of eDNA, and 75% yielded positive bacterial cultures. Bacterial culture results included H. influenzae, Methicillin-resistant Staphylococcus aureus, S. pneumoniae, M. catarrhalis, and P. aeruginosa.
Conclusion:
Positive labeling of otorrhea solids for eDNA and IHF, in combination with microbiological culture results, indicated that biofilms likely played a key role in chronic otorrhea. Moreover, as a known critical structural component of biofilms, these findings suggest that DNABII proteins in association with eDNA may serve as an important therapeutic target in post-tympanostomy tube otorrhea.
Level Of Evidence:
NA. Laryngoscope, 126:1946-1951, 2016.
Insights
Biofilms contribute to difficult-to-treat pediatric otorrhea (ear discharge). This study found extracellular DNA (eDNA) and integration host factor (IHF) in 60% of samples, suggesting biofilms are key in persistent ear infections.
Area of Science:
- Microbiology
- Otolaryngology
- Pediatrics
Background:
- Otitis media is common in children, and post-tympanostomy tube otorrhea can be challenging to treat with antibiotics.
- Biofilms are implicated in chronic and recurrent otitis media and otorrhea.
Purpose of the Study:
- To investigate the microbial composition of post-tympanostomy tube otorrhea.
- To determine the presence of biofilm fragments, extracellular DNA (eDNA), and integration host factor (IHF) in these samples.
Main Methods:
- Clinical samples from pediatric patients with persistent otorrhea were analyzed.
- Biofilm analysis involved labeling for IHF and eDNA using immunofluorescence and DAPI staining.
- Microbial cultures were performed to identify bacterial species.
Main Results:
- Nine out of 15 (60%) samples showed positive labeling for IHF and eDNA, indicating biofilm presence.
- Bacterial cultures were positive in 75% of samples, identifying common pathogens like H. influenzae and MRSA.
- Specific bacteria identified included H. influenzae, Methicillin-resistant Staphylococcus aureus, S. pneumoniae, M. catarrhalis, and P. aeruginosa.
Conclusions:
- The presence of eDNA and IHF in otorrhea solids, along with positive bacterial cultures, strongly suggests biofilms play a significant role in chronic otorrhea.
- DNABII proteins, such as IHF, in conjunction with eDNA, represent a potential therapeutic target for treating post-tympanostomy tube otorrhea.
