Predisposing factors to bacterial colonization in chronic obstructive pulmonary disease

Abstract

The aim of this prospective observational study was to determine those factors influencing bacterial colonization in patients with stable chronic obstructive pulmonary disease (COPD).Eighty-eight outpatients with stable COPD and 20 patients with normal spirometry and chest radiography (controls) had a fibreoptic bronchoscopy performed with topical aerosol anaesthesia. Bacterial colonization was determined using the protected specimen brush (PSB) with a cut-off $10 3 colony-forming units (CFU . mL -1 ). The influence of age, degree of airflow obstruction, smoking habit, pack-yrs of smoking, and chest radiographic findings on bacterial colonization were assessed by univariate and multivariate analysis.Significant bacterial growth was found in 40% of patients and in none of the controls. Haemophilus influenzae, Streptococcus viridans, S. pneumoniae and Moraxella catarrhalis were the most frequent pathogens. After adjustment for other variables, severe airflow limitation (odds ratio (OR) 5.11, 95% confidence interval (CI) 1.45±17.9) and current smoking (OR 3.17, 95% CI 2.5±8) remained associated with positive bacterial cultures. When only potentially pathogenic micro-organisms were considered, significant bacterial growth was found in 30.7% of patients, with severe airflow obstruction (OR 9.28, 95% CI 2.19±39.3) being the only variable independently associated with positive bacterial cultures.Our results show that stable chronic obstructive pulmonary disease patients have a high prevalence of bacterial colonization of distal airways which is mainly related to the degree of airflow obstruction and cigarette smoking. Eur Respir J 1999; 13: 343±348. Despite intensive investigation, the precise role of bacterial infection in the production and recurrent aspects of chronic obstructive pulmonary disease (COPD) has yet to be elucidated [1,2]. It has been estimated that the lower respiratory tract of stable COPD patients is colonized in 50±100% of cases [3,4]. In most studies, however, the tracheobronchial microflora was characterized by unreliable diagnostic techniques (e.g. expectorated sputum, transtracheal aspiration) owing to the lack of specificity and the absence of quantitative cultures [5±8]. Fibreoptic bronchoscopy using a protected specimen brush (PSB) catheter is a highly sensitive and specific technique used to obtain uncontaminated specimens for culture from the lower respiratory tract [9]. In patients with stable COPD, the prevalence of lower airway bacterial colonization using the PSB varies between 25 and 55.5% [10±12]. However, predisposing factors to bacterial colonization in patients with stable COPD have not been well defined.To determine precisely the influence of different factors, such as age, degree of airflow obstruction, smoking habit, pack-yrs of smoking and chest radiographic findings, on the detection of bacteria in COPD patients, a prospective study was conducted using the PSB and quantitative cultures. Materials and methods Study populationThe study was carried out in a 1,000-bed te...

Colonization and Bronchiectasis in Patients with Advanced Chronic Obstructive Pulmonary Disease

“…Similar rates were observed by Monso et al (25%), in 41 samples of patients with chronic bronchitis [14]. Previous studies have demonstrated both decreasing FEV1 and continued smoking as independent risk factors for lower respiratory bacterial colonization in advanced COPD [16].…”

Viral–bacterial interactions in the respiratory tract

“…Several studies have reported a persistent presence of PPMs in the LRT of individuals with chronic pulmonary disease, most prominently COPD (Cabello et al, 1997;Monsó et al, 1999;Zalacain et al, 1999). Likewise, microbiome analyses have revealed a change in microbial communities in the LRT including a reduction in microbiome diversity and an increased abundance of PPMs in subjects with COPD (ErbDownward et al, 2011;Garcia-Nuñez et al, 2014).…”

“…influenzae is the most commonly found bacterial species in the lungs of COPD patients, being cultured from samples of about 25 % of all patients during stable disease (Cabello et al, 1997;Monsó et al, 1999;Zalacain et al, 1999). Exposure of respiratory epithelial cells to H. influenzae increases the expression of ICAM-1, the main receptor for major group HRV.…”

Incidence and prognostic value of respiratory events in acute leukemia

“…Conversely, REs were significantly more frequent in smokers (420 packyear) or patients with pre-existing lung disease. There may be several explanations for the increased rate of REs in smokers: (i) cigarette smoke might impair the clearance and detoxification of bacteria, resulting in a higher prevalence of bacterial colonization of proximal or distal airways; 16,17 (ii) smoking is associated with immunologic disturbances; 18,19 (iii) in healthy long-term smokers, myocardial blood flow is impaired and the degree of impairment correlates with the number of years the patient has smoked; 20,21 and (iv) in animal models, cigarette smokes impairs cardiopulmonary function and increases capillary permeability. This could explain the hydration-related pulmonary edema occurring at the onset of chemotherapy.…”