Bacterial colonisation in patients with bronchiectasis: microbiological pattern and risk factors

Area of Science:

• Pulmonary Medicine
• Infectious Diseases
• Microbiology

Background:

• Bronchiectasis is a chronic lung condition characterized by airway damage and mucus buildup.
• Airway colonization by potential pathogenic microorganisms (PPMs) is a significant concern in bronchiectasis management.
• Understanding the incidence, diagnostic methods, and risk factors for airway colonization is crucial for patient care.

Purpose of the Study:

• To determine the incidence of airway colonization by PPMs in stable bronchiectasis patients.
• To evaluate the diagnostic yield of non-invasive and bronchoscopic techniques for detecting airway colonization.
• To identify risk factors associated with airway colonization in this patient population.

Main Methods:

• A 2-year prospective study involving 77 stable bronchiectasis patients.
• Utilized pharyngeal swabs, sputum cultures, quantitative protected specimen brush (PSB) cultures, and bronchoalveolar lavage (BAL) for microbial analysis.
• Established cut-off points for PSB (> or =10(2) cfu/ml) and BAL (> or =10(3) cfu/ml) for significant colonization.

Main Results:

• A high incidence of bronchial colonization by PPMs was observed in 64% of patients.
• Haemophilus influenzae (55%) and Pseudomonas spp. (26%) were the most frequently isolated PPMs.
• Risk factors for colonization included early bronchiectasis diagnosis (before age 14), FEV1 <80% predicted, and varicose/cystic bronchiectasis.

Conclusions:

• Clinically stable bronchiectasis patients exhibit a high prevalence of airway colonization by PPMs.
• Sputum culture serves as a reliable, non-invasive alternative to bronchoscopic methods for assessing colonization.
• Early disease diagnosis, specific bronchiectasis morphology, and reduced FEV1 are significant risk factors for PPM colonization.