An overview of adenoid microbiome using 16S rRNA gene sequencing-based metagenomic analysis

The upper respiratory tract harbors the highest bacterial density in the whole respiratorysystem. Adenoids, which are located in the nasopharynx, are a major site of bacterialcolonies in the upper airways. Our goal was to use culture-independent moleculartechniques to identify the breadth of bacterial diversity in the adneoid vegetations ofchildren suffering from chronic rhinosinusitis and obstructive sleep apnea. In total 21adenoid samples were investigated using amplification and sequencing of V3-V4hypervariable region of the bacterial 16S rRNA gene. Among the most common bacterialspecies found were Veillonella atypica, Fusobactrium nucelatum, Shaalia odontolyticaand Moraxella catarrhalis. Veillonella atypica and Fusbacterium nucelatum dominated themicrobiome in all 21 sample attributing to more than 60% of all detected genetic material.Since both Veillonella atypica and Fusobacterium nucleatum are, predominantly, oralcavity and dental microorganisms our findings may suggest oral microbiome migrationdeeper into the oropharynx and nasopharynx where these bacteria colonize adenoidvegetations.