Evaluation of BACTEC MGIT 960 and BACTEC 460TB Systems for Recovery of Mycobacteria from Clinical Specimens of a University Hospital with Low Incidence of Tuberculosis

Clinical samples obtained over a period of 8 months (n = 2,624) were processed in parallel with the BACTEC 460TB system, with the MGIT 960 system, and in Löwenstein-Jensen (LJ) medium, resulting in the recovery of 127 mycobacteria. Recovery rates in combinations of the BACTEC 460TB or MGIT 960 system with LJ were, respectively, 94.7 and 94.7% for Mycobacterium tuberculosis complex (n = 57) and 91.4 and 70.0% for nontuberculous mycobacteria (n = 70). Contamination rates, elevated in the MGIT 960 system, were associated with patients (cystic fibrosis) and type of material but not with transport time. Detection time was reduced in the MGIT 960 system.