The Bacteriology of Bronchiectasis in Hong Kong Investigated by Protected Catheter Brush and Bronchoalveolar Lavage

Abstract
Bacteria often colonize the lower respiratory tract of patients with bronchiectasis. Although the role of these bacteria in the pathogenesis of the disease is uncertain, their accurate identification is important for epidemiologic and treatment purposes. Therefore, the aims of this study were: (1) to identify these bacteria in patients with bronchiectasis without cystic fibrosis using the protected catheter brush (PCB) in order to avoid oropharyngeal contamination, and (2) to compare the results of bronchoalveolar lavage (BAL) with PCB. Quantitative culture was performed on PCB and BAL specimens obtained from the most severely affected lobes of 23 patients with bronchiectasis. Results of PCB showed no significant growth (< 103 colony-forming units [cfu]/ml) in nine patients and 17 significant isolates (> 103 cfu/ml) in the rest: H. influenzae, 5; P. aeruginosa. 4; K. ozaenae, 2; S. aureus, 2; P. fluorescens, 1; S. pneumoniae, 1; Veillonella, 1; and coag.-ve Staph., 1. For BAL, the results were the same (20 isolates) regardless of whether 104 or 105 cfu/ml was chosen as the cutoff point. More organisms were cultured from BAL specimens, and these included all but one of the organisms cultured from PCB. We conclude that the bacteriology of bronchiectasis in Hong Kong is different from that reported in sputum studies in the West (mainly H. influenzae, S. pneumoniae, and S. aureus), and with 104 cfu/ml as the cutoff point, BAL gives comparable results to PCB.