Sputum purulence-associated microbial community compositions in adults with bronchiectasis

Bronchiectasis is a debilitating chronic inflammatory airway disease which arises from multiple etiologies. The interplay among the etiology, altered microenvironment and defective host-defense may have predisposed to recurrent chest infections of pathogens (1,2) that correlate with bronchiectasis exacerbations and increased mortality. Sputum production, which results from mucus hypersecretion and exaggerated airway inflammation, is one of the major complaints among symptomatic bronchiectasis patients (3) whose sputum bacterial compositions are heterogeneous (4,5). Clinically, sputum purulence has been an important parameter reflecting the magnitude of airway inflammation and infection. Sputum purulence, which is commonly rated by using color charts in clinical settings, has been correlated with sputum myeloperoxidase and neutrophil elastase activity and pathogen (i.e., pathogenic bacteria) infections (6,7)