Composition and Variation of Respiratory Microbiota in Healthy Military Personnel

Abstract
Certain occupational and geographical exposures have been associated with an increased risk of lung disease. As a baseline for future studies, we sought to characterize the upper respiratory microbiomes of healthy military personnel in a garrison environment. Nasal, oropharyngeal, and nasopharyngeal swabs were collected from 50 healthy active duty volunteers eight times over the course of one year (1107 swabs, completion rate = 92.25%) and subjected to pyrosequencing of the V1±V3 region of 16S rDNA. Respiratory bacterial taxa were characterized at the genus level, using QIIME 1.8 and the Ribosomal Database Project classifier. High levels of Staphylococcus, Corynebacterium, and Propionibacterium were
observed among both nasal and nasopharyngeal microbiota, comprising more than 75% of all operational taxonomical units (OTUs).

In contrast, Streptococcus was the sole dominant bacterial genus (approximately 50% of all OTUs) in the oropharynx. The average bacterial diversity was greater in the oropharynx than in the nasal or nasopharyngeal region at all time points. Diversity analysis indicated a significant overlap between nasal and nasopharyngeal samples, whereas oropharyngeal samples formed a cluster distinct from these two regions. The study produced a large set of pyrosequencing data on the V1±V3 region of bacterial 16S rDNA for the respiratory microbiomes of healthy active duty Service Members. Pre-processing of sequencing reads showed good data quality. The derived microbiome profiles were consistent both internally and with previous reports, suggesting their utility for further analyses and association studies based on sequence and demographic data.