title: Airway Microbial Community Turnover Differs by BPD Severity in Ventilated Preterm Infants.
abstract: Preterm birth exposes the developing lung to an environment with direct exposure to bacteria, often facilitated by endotracheal intubation. Despite evidence linking bacterial infections to the pathogenesis of bronchopulmonary dysplasia (BPD), systematic studies of airway microbiota are limited. The objective was to identify specific patterns of the early respiratory tract microbiome from tracheal aspirates of mechanically ventilated preterm infants that are associated with the development and severity of BPD. Infants with gestational age ≤34 weeks, and birth weight 500-1250g were prospectively enrolled. Mechanically ventilated infants had tracheal aspirate samples collected at enrollment, 7, 14, and 21 days of age. BPD was determined by modified NIH criteria with oxygen reduction tests; infants without BPD were excluded due to low numbers. Aspirates were processed for bacterial identification by 16S rRNA sequencing, and bacterial load by qPCR. Cross-sectional analysis was performed using 7 day samples and longitudinal analysis was performed from subjects with at least 2 aspirates. Microbiome analysis was performed on tracheal aspirates from 152 infants (51, 49, and 52 with mild, moderate, and severe BPD, respectively). Seventy-nine of the infants were included in the cross-sectional analysis and 94 in the longitudinal. Shannon Diversity, bacterial load, and relative abundance of individual taxa were not strongly associated with BPD status. Longitudinal analysis revealed that preterm infants who eventually developed severe BPD exhibited greater bacterial community turnover with age, acquired less Staphylococcus in the first days after birth, and had higher initial relative abundance of Ureaplasma. In conclusion, longitudinal changes in the airway microbial communities of mechanically ventilated preterm infants may be associated with BPD severity, whereas cross-sectional analysis of airway ecology at 7 days of age did not reveal an association with BPD severity. Further evaluation is necessary to determine whether the observed longitudinal changes are causal or in response to clinical management or other factors that lead to BPD.
authors.affiliation: Department of Biostatistics, Colorado School of Public Health, University of Colorado, Aurora, Colorado, United States of America.|Section of Pulmonary, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, United States of America.
authors.forename: Brandie D
authors.initials: BD
authors.lastname: Wagner
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora, Colorado, United States of America.
authors.forename: Marci K
authors.initials: MK
authors.lastname: Sontag
authors.affiliation: Section of Pulmonary, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, United States of America.
authors.forename: J Kirk
authors.initials: JK
authors.lastname: Harris
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora, Colorado, United States of America.
authors.forename: Joshua I
authors.initials: JI
authors.lastname: Miller
authors.affiliation: Department of Biostatistics, Colorado School of Public Health, University of Colorado, Aurora, Colorado, United States of America.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Morrow
authors.affiliation: Section of Infectious Disease, Department of Medicine, School of Medicine, University of Colorado, Aurora, Colorado, United States of America.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Robertson
authors.affiliation: Section of Pulmonary, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, United States of America.
authors.forename: Mark
authors.initials: M
authors.lastname: Stephens
authors.affiliation: Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States of America.
authors.forename: Brenda B
authors.initials: BB
authors.lastname: Poindexter
authors.affiliation: Section of Pulmonary, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, United States of America.|The Pediatric Heart-Lung Center, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, United States of America.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Abman
authors.affiliation: The Pediatric Heart-Lung Center, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, United States of America.|Section of Critical Care Medicine, Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado, United States of America.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Mourani
mesh_terms: D001724:Birth Weight; D001997:Bronchopulmonary Dysplasia / Q000235:genetics / Q000382:microbiology* / Q000473:pathology; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007442:Intubation, Intratracheal / Q000009:adverse effects; D008168:Lung / Q000382:microbiology* / Q000473:pathology; D008297:Male; D011247:Pregnancy; D047928:Premature Birth / Q000382:microbiology / Q000473:pathology; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D012121:Respiration, Artificial; D013210:Staphylococcus / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D014132:Trachea / Q000382:microbiology* / Q000473:pathology
chemical_list: D012336:RNA, Ribosomal, 16S