Background: The differentiation of Mycobacterium tuberculosis (MTB) from nontuberculous mycobacteria (NTM) is of primary importance for infection control and choice of antimicrobial therapy. The diagnosis of diseases caused by NTM is difficult because NTM are prevalent in the environment and have fastidious properties. In this study, we evaluated the real-time PCR-based MTB/NTM detection kit for its usefulness in discrimination of MTB and NTM species.

Methods: A total of 155 sputum specimens whose AFB staining smear and culture were positive were used for this study. Among them, 59 and 96 samples had been identified as MTB and NTM, respectively. DNA obtained from sputum specimens was subjected to analysis with MolecuTech Real MTB-ID^Ⓡ (M&D, Korea) real-time PCR-based MTB/NTM detection kit. Subsequently, the results of MolecuTech Real MTB- ID^Ⓡ were compared with AFB staining smear and culture results.

Results: The positive rate of MolecuTech Real MTB- ID^Ⓡ to detect MTB and NTM was 98.3% (58/59) and 97.9 (94/96), respectively, using sputum specimens.

Conclusion: For detection of MTB/NTM, the sensitivity and specificity of MolecuTech Real MTB-ID^Ⓡ were comparable to those of conventional methods. Therefore, this study suggests the usefulness of real-time PCR-based MolecuTech Real MTB-ID^Ⓡ for rapid detection of MTB/NTM from direct specimens. (Korean J Clin Microbiol 2011;14:103-109)