PT - JOURNAL ARTICLE AU - Kohei Hasegawa AU - Jonathan M. Mansbach AU - Nadim J. Ajami AU - Janice A. Espinola AU - David M. Henke AU - Joseph F. Petrosino AU - Pedro A. Piedra AU - Chad A. Shaw AU - Ashley F. Sullivan AU - Carlos A. Camargo, Jr TI - Association of nasopharyngeal microbiota profiles with bronchiolitis severity in infants hospitalised for bronchiolitis AID - 10.1183/13993003.00152-2016 DP - 2016 Nov 01 TA - European Respiratory Journal PG - 1329--1339 VI - 48 IP - 5 4099 - http://erj.ersjournals.com/content/48/5/1329.short 4100 - http://erj.ersjournals.com/content/48/5/1329.full SO - Eur Respir J2016 Nov 01; 48 AB - Little is known about the relationship between the specific airway microbiota composition and severity of bronchiolitis. We aimed to identify nasopharyngeal microbiota profiles and link these profiles to acute severity in infants hospitalised for bronchiolitis.We conducted a multicentre prospective cohort study of 1005 infants (age <1 year) hospitalised for bronchiolitis over three winters, 2011–2014. By applying a 16S rRNA gene sequence and clustering approach to the nasopharyngeal aspirates collected within 24 h of hospitalisation, we determined nasopharyngeal microbiota profiles and their association with bronchiolitis severity. The primary outcome was intensive care use, i.e. admission to an intensive care unit or use of mechanical ventilation.We identified four nasopharyngeal microbiota profiles: three profiles were dominated by one of Haemophilus, Moraxella or Streptococcus, while the fourth profile had the highest bacterial richness. The rate of intensive care use was highest in infants with a Haemophilus-dominant profile and lowest in those with a Moraxella-dominant profile (20.2% versus 12.3%; unadjusted OR 1.81, 95% CI 1.07–3.11, p=0.03). After adjusting for 11 patient-level confounders, the rate remained significantly higher in infants with Haemophilus-dominant profiles (OR 1.98, 95% CI 1.08–3.62, p=0.03). These findings were externally validated in a separate cohort of 307 children hospitalised for bronchiolitis.Haemophilus-dominant airway microbiota associates with higher risk of intensive care in infants with bronchiolitis http://ow.ly/Bur6302vjRZ