Which of the following organisms is unlikely to be found in the sputum of patients with cystic fibrosis?

In patients with cystic fibrosis, Hemophilus influenzae and Staphylococcus aureus are responsible for early colonisation. Later Pseudomonas is the main organism colonising the airways in 50% of patients, followed by Burkholderia cepacia. Aspergillus fumigatus is the most common fungus that can colonize airways with/ without causing any lung disease. It can be found in airways of normal people as well as cystic fibrosis.