Moraxella-associated Nasopharyngeal Microbiota Associate with Upper Respiratory Infection and Sinusitis

Introduction/Background: Upper respiratory infections (URI) and acute bacterial sinusitis account for a large portion of medical expenditures in the United States, can cause significant morbidity in children and are a leading contributor to antimicrobial use. We hypothesized that distinct bacterial microbiota assemblages exist in the nasopharynx of children that modify their risk of acute sinusitis or URI.Methods: We analyzed bacterial 16S rRNA microbiota profiles of nasopharyngeal swabs (n=354) collected longitudinally from 58 children, aged four to seven years. Within the one-year observation period, symptoms of URI and sinusitis were recorded and nasopharyngeal samples were obtained. Results: Variance in the composition of the nasopharyngeal microbiota was related to household exposures including tobacco smoke and presence of pets. Based on nasopharyngeal microbiota composition, samples were divisible into four distinct groups. Of these, Moraxella-dominated nasopharyngeal microbiota increased the risk of sinusitis (RR=2.62, 95% CI=1.18-5.84), with a trend for URI (RR=2.11, 95% CI=0.95-4.69), when compared to the other three microbiota assemblages.Conclusion: These results indicate that sinusitis and URI, to a lesser extent, is associated with the presence of a Moraxella-dominated nasopharyngeal microbiota in this pediatric population.