Use of RNA/RNA Duplex, Base Pair-mismatch Assay and 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl Tetrazolium Bromide (MTT) Assay for Rapid Detection of Rifampin-resistant Mycobacterium tuberculosis

ABSTRACT

BACKGROUND: Multidrug-resistant tuberculosis is an increasing concern for public health in many parts of the world. We have evaluated the specificity and sensitivity of the mismatch assay and 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay in detecting rifampin- resistant Mycobacterium tuberculosis. METHODS: Eleven rifampin-susceptible and 15 rifampin-resistant M. tuberculosis strains were isolated from clinical specimens obtained from patients in Yonsei University College of Medicine, Severance Hospital. RNA/RNA duplex, base pair-mismatch assay (Mismatch Detect II kit, Ambion) and MTT assay were performed. RESULTS: The specificity and sensitivity of detection of rifampin resistance were 91% and 87% in mismatch assay and 73% and 67% in MTT assay, respectively. CONCLUSION: These results suggest the usefulness of mismatch assay in detecting rifampin-resistant Mycobacterium tuberculosis.