Final answer:
The most common pathogen in younger children with CF is Staphylococcus aureus, and in older children, it is Pseudomonas aeruginosa. Pseudomonas is known for causing serious infections in CF patients due to its biofilm-forming ability and antibiotic resistance.
Step-by-step explanation:
The most common pathogen in younger children with cystic fibrosis (CF) is Staphylococcus aureus, and in older children, the suspect pathogen is often Pseudomonas aeruginosa.
Therefore, the correct answer is A) Staphylococcus aureus, Pseudomonas aeruginosa.
Pseudomonas aeruginosa is known to cause serious respiratory infections such as Pseudomonas Pneumonia, particularly in patients with CF and those on artificial ventilators, due to its ability to thrive in the thick mucus present in the lungs and form biofilms.
Additionally, it is notorious for being antibiotic-resistant and for producing a variety of exotoxins which contribute to the severity of the infections.