To assess the role of infection in the pathogenesis of acute exacerbation of COPD and to identify common agents causing infective acute exacerbation of COPD.
Microbiology sampling of sputum was performed in patient with diagnosis of COPD. Control consisted of 30 outpatients with stable COPD with no changes in volume/aspect of sputum or level of dyspnea in previous 15 days. Cases consisted of 60 exacerbated COPD patients. Fresh morning samples of sputum were processed on the day of collection. Each species was identified by standard methods. This study was approved by faculty of Medicine, Dhaka University, Dhaka.
Positive cultures were obtained in 6(20%) out of 30controls. Pseudomonas spp. were cultured from 3samples. Klebsiella spp.1, Streptococcus pneumoniae1, Haemophilus influenzae 1 were cultured from another 3 samples. Positive cultures were obtained in 39(65%) out of 60 cases. Pseudomonas spp.15, Klebsiella spp.8, Acinetobacter spp.4, Streptococcus pneumoniae 4, Haemophilus influenzae 2, Moraxella catarrhalis 2, Enterobacter spp.1, mixed organisms (Pseudomonas spp.+ Klebsiella spp) 2, (Pseudomonas spp.+ Acinetobacter spp.) 1, were culture from 39 samples. There were statistically significant number of positive sputum culture among acute exacerbated than stable COPD patients (P < 0.001). Gram negative bacilli, Pseudomonas spp. and Klebsiella spp. were cultured in majority of sputum sample of culture positive stable and exacerbated COPD patient.
The prevalence of lower airway bacterial colonization in outpatients with stable COPD is high and mainly due to Pseudomonas and Klebsiella and affect 20% of this population. The greater rate of isolation of pathogenic bacteria in exacerbated than in stable COPD in this study supports the pathogenic role of bacteria in a proportion of acute exacerbation of COPD. The organism commonly plays pathogenic role in acute exacerbation of COPD are Pseudomonas and Klebsiella. Acinetobacter, Moraxella catarrhalis and Enterobacter also contribute.
Identification of common microbial agents causing infective acute exacerbation of COPD will ultimately facilitate prompt initiation of appropriate antimicrobial agents and thus will help rapid recovery from acute exacerbations of COPD.
M. Rahman, None.