Microbial burden and viral exacerbations in a longitudinal multicenter COPD cohort

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by frequent exacerbation phenotypes independent of disease stage. Increasing evidence shows that the microbiota plays a role in disease progression and severity, but long-term and international multicenter assessment of the variations in viral and bacterial communities as drivers of exacerbations are lacking. Two-hundred severe COPD patients from Europe and North America were followed longitudinally for 3 years. We performed nucleic acid detection for 20 respiratory viruses and 16S ribosomal RNA gene sequencing to evaluate the bacterial microbiota in 1179 sputum samples collected at stable, acute exacerbation and follow-up visits. Similar viral and bacterial taxa were found in patients from the USA compared to Bulgaria and Czech Republic but their microbiome diversity was significantly different (P