Nontuberculous mycobacteria: Experience in a respiratory departament of a general university hospital

Background: Nontuberculous micobacteria (NTM) represent a diagnostic and therapeutic challenge, since they can grow on body surfaces without causing disease. Methods: All cases with positive culture from respiratory samples in the last 10 years were recruited. Identification of NTM was carried out by AccuProbe and GenoType Mycobacterium CM/AS system. ATS criteria were considered to analyze the radiological, clinical and microbiological findings. Results: NTM were detected in 30 patients (38% out of 80 patients tested positive to NTM in the microbiology department).The average age was 59 years and women represented 52%. Eleven strains of NTM have been identified. The 77% of patients presented underlying pulmonary disease and previous history of tuberculosis was found in 37% of cases. The most frequent CT scan pattern was bronchiectasis followed by multiple nodules. Sputum culture was used for microbiological diagnosis in 77% of cases and the smear resulted positive in 20% of subjects. In this study, 33% of patients received treatment, of which 80% tested positive for Mycobacterium avium-intracellulare (MAI). Conclusions: The NTM more prevalent was MAI. Only a third of patients with NTM met criteria for treatment.