Airway Microbial Community Turnover Differs by BPD Severity in Ventilated Preterm Infants

Area of Science:

• Neonatal Medicine
• Microbiology
• Pulmonary Medicine

Background:

• Preterm birth and mechanical ventilation increase the risk of lung infections.
• Bacterial infections are implicated in bronchopulmonary dysplasia (BPD) pathogenesis.
• Systematic studies on the airway microbiome in relation to BPD severity are limited.

Purpose of the Study:

• To identify specific patterns in the early respiratory tract microbiome of mechanically ventilated preterm infants.
• To determine associations between these microbial patterns and the development/severity of BPD.

Main Methods:

• Prospective enrollment of preterm infants (gestational age ≤34 weeks, birth weight 500-1250g).
• Collection of tracheal aspirate samples at multiple time points (enrollment, 7, 14, 21 days).
• Bacterial identification via 16S rRNA sequencing and bacterial load quantification by qPCR; BPD diagnosis using modified NIH criteria.

Main Results:

• No strong association found between Shannon Diversity, bacterial load, or individual taxa abundance at 7 days and BPD status.
• Longitudinal analysis showed greater bacterial community turnover in infants who developed severe BPD.
• Infants with severe BPD acquired less Staphylococcus and had higher initial Ureaplasma abundance.

Conclusions:

• Longitudinal changes in airway microbial communities are associated with BPD severity in preterm infants.
• Cross-sectional analysis at 7 days did not reveal a significant association with BPD severity.
• Further research is needed to ascertain causality of observed longitudinal microbial changes.