The patient was febrile with a respiratory rate of 30 breaths/min and oxygen saturation of 94% on room air, but chest auscultation findings were unremarkable. There was no blood leukocytosis, and blood cultures were negative. A chest radiograph showed patchy, ill-defined airspace opacities over both lung fields (Fig 1). A CT scan of the thorax revealed multiple areas of consolidation with cavitation in both lungs (Fig 2). The Mantoux tuberculin skin test was nonreactive. Three good-quality sputum samples were received for laboratory investigations. Following decontamination according to standard protocol,2 the first two of three good-quality sputum samples were inoculated onto both Mycobacteria Growth Indicator Tube (MGIT) (Becton Dickinson and Co) and Lowenstein-Jensen (LJ) medium while the third sample was inoculated directly onto LJ medium only. WBC counts and epithelial cell counts were not routinely performed in our mycobacterial laboratory. All three samples were direct smear negative for acid-fast bacilli. After seven days of incubation, growths were detected on MGIT and LJ medium for only the first and second sputum samples. GenoType Mycobacterium CM (common mycobacteria) and AS (additional species) tests (Hain Lifescience GmbH) using DNA·STRIP technology (Hain Lifescience GmbH), which permitted the identification of 30 mycobacterial species, were used to identify the growths on the MGIT and LJ medium. The isolates, however, were not identifiable by these two tests and, therefore, were not among the nontuberculous mycobacteria listed in the two panels. Because the mycobacteria was deemed a rapid grower, empirical treatment with a combination of rifampicin, ethambutol, and levofloxacin was given, and the patient’s symptoms improved after 1 week.