Background: Acute otitis media, an infection of the middle ear, can become chronic after multiple episodes. Microbial influence on chronic otitis media remains unclear. It has been reported that mucin glycoproteins are required for middle ear immune defense against pathogens. We aim to characterize the middle ear effusion (MEE) microbiome using high-throughput sequencing and assess potential associations in microbiome diversity with the presence of the secretory mucins MUC5B and MUC5AC. We hypothesize that MEEs containing MUC5B will exhibit a microbiome largely devoid of typical acute otitis media bacteria.
Methods: Fifty-five MEEs from children undergoing myringotomy at Children’s National Health System were recovered. Mucin was semiquantitatively determined through Western blot analysis. DNA was subjected to 16S rRNA amplicon sequencing using the Illumina MiSeq platform. Raw data were processed in mothur (SILVA reference database). Alpha- and beta-diversity metrics were determined. Abundance differences between sample groups were estimated.
Results: MUC5B was present in 94.5% and MUC5AC in 65.5% of MEEs. Sequencing revealed 39 genera with a relative abundance ≥0.1%. Haemophilus (22.54%), Moraxella (11.11%) and Turicella (7.84%) were the most abundant. Turicella and Pseudomonas proportions were greater in patients older than 24 months of age. In patients with hearing loss, Haemophilus was more abundant, while Turicella and Actinobacteria were less abundant. Haemophilus was also more abundant in samples containing both secretory mucins.
Conclusions: The microbiome of MEEs from children with chronic otitis media differs according to specific clinical features, such as mucin content, age and presence of hearing loss. These associations provide novel pathophysiologic insights across the spectrum of otitis media progression.
From the *Children’s National Health System, Sheikh Zayed Institute, Washington DC; †Computational Biology Institute, George Washington University, Ashburn, VA; ‡CIBIO-InBIO, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal; §Children’s National Health System, Center for Genetic Medicine Research, Washington DC; and ¶Department of Integrative Systems Biology, George Washington University, Washington DC.
Accepted for publication October 5, 2016.
This work was supported by R01DC012377 to Diego Preciado from the NIDCD.
The authors have no conflict of interest to disclose.
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Address for correspondence: Diego Preciado, MD, PhD, Children’s National Health System, Sheikh Zayed Institute for Pediatric Surgical Innovation, 111 Michigan Ave NW, Washington, DC 20010. E-mail: email@example.com