Evaluation of the BDProbeTec strand displacement amplification assay in comparison with the AMTD II direct test for rapid diagnosis of tuberculosis.

The BDProbeTec MTB assay for direct detection of Mycobacterium tuberculosis was evaluated in comparison with the AMTD-II assay on 94 samples from different patients with clinical suspicion of tuberculosis. Using a combination of culture on Lowenstein-Jensen medium (with or without preculture in BACTEC 9000) and clinical diagnosis as the standard, BDProbeTec MTB showed high sensitivity and specificity (96.1% and 100%, respectively), similar to AMTD-II (96.1% and 97.1%, respectively), with significantly higher sensitivity than the Ziehl-Neelsen stain for acid-fast bacilli (73%, p < 0.05).