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

Patients with cystic fibrosis are at risk for colonization and/or infection with a number of pathogens, and in general, these infections have a temporal relationship.In childhood, the most frequently isolated organisms are Haemophilus influenza and Staphylococcus aureus.As patients age, Pseudomonas aeruginosa becomes the predominant pathogen. Interestingly, Aspergillus fumigatus is found in the airways of up to 50% of cystic fibrosis patients.All these organisms merely colonize the airways but occasionally can also cause disease.Atypical mycobacteria can occasionally be found in the sputum but are often merely colonizers.