A retrospective study comparing the diagnostic performance of the BACTEC™ MGIT™ 960 system (M960 system; BD Worldwide, Franklin Lakes, NJ, USA) with Löwenstein–Jensen (L–J) culture to detect mycobacteria in sputum specimens from patients with suspected pulmonary tuberculosis (TB).

Sputum samples were analysed for the presence of acid-fast bacilli (AFB). Samples were inoculated into the M960 system and L–J culture. Positive cultures were examined for the presence of AFB.

The M960 method detected significantly more positive samples than L–J culture (818/1676 [48.8%] vs 692/1676 [41.3%]). Using L–J culture as reference, the sensitivity, specificity, positive predictive and negative predictive values of the M960 system were 91.0%, 76.1%, 77.0% and 92.2%, respectively. The time-to-detection of mycobacteria was 11.78 ± 5.16 days for M960 and 24.17 ± 8.73 days for L–J.

The M960 system had better diagnostic capability than L–J culture. Clinical value may be maximized by combining results from both methods.