Which organism is commonly associated with airway infections in cystic fibrosis and forms robust biofilms?

• A. Staphylococcus aureus
• B. Pseudomonas aeruginosa
• C. Burkholderia cepacia
• D. Klebsiella pneumoniae

Answer: (B)

Biofilm formation drives chronic airway infection in cystic fibrosis, and the organism most classically linked to this in the CF lung is Pseudomonas aeruginosa. It often becomes mucoid, producing a protective alginate-rich biofilm that adheres to airway surfaces. This biofilm acts like a fortress, shielding the bacteria from antibiotics and immune defenses, which allows persistent colonization and a gradual decline in lung function. While Staphylococcus aureus is a common early colonizer and Burkholderia cepacia can cause severe disease, neither is as consistently associated with the robust biofilm–mediated chronic infection seen with Pseudomonas aeruginosa. Klebsiella pneumoniae is less typical in CF airways.