What are the common pathogens responsible for pulmonary infections in patients with cystic fibrosis?

• A. Staphylococcus aureus and Pseudomonas aeruginosa
• B. Streptococcus pneumoniae and Haemophilus influenzae
• C. Escherichia coli and Klebsiella pneumoniae
• D. Mycobacterium tuberculosis and Legionella pneumophila

Answer: (A)

In patients with cystic fibrosis, the primary pathogens associated with pulmonary infections are indeed Staphylococcus aureus and Pseudomonas aeruginosa. Cystic fibrosis leads to thick, viscous mucus production in the lungs, creating an environment that is conducive to bacterial colonization and infection.

Staphylococcus aureus is often one of the first organisms to infect the respiratory tracts of children with cystic fibrosis, especially in the early stages of the disease. As the disease progresses, Pseudomonas aeruginosa becomes a more dominant pathogen, frequently establishing chronic infections in the lungs of these patients. This shift is significant because Pseudomonas aeruginosa is known for its resilience and ability to evade the immune response, leading to severe respiratory complications.

In contrast, the other options listed comprise pathogens that are less commonly associated with pulmonary infections in cystic fibrosis. Streptococcus pneumoniae and Haemophilus influenzae are more typically linked to acute respiratory infections in the general population, rather than being specific to cystic fibrosis patients. Escherichia coli and Klebsiella pneumoniae are more often implicated in other types of infections, such as urinary tract infections, rather than in the lung infections characteristic of cystic fibrosis