Mycobacterium tuberculosis Detection in Direct Clinical Specimens by Polymerase Chain Reaction

Tuberculosis is the main problem for Thailand and many countries in the world, which the major cause of human infection is Mycobacterium tuberculosis. The Mycobacterium spp. diagnosis by culture and biochemical tests is time-consuming so itus really necessary to develop the better method to identify these organisms. In this study, we amplified DNA in HSP65 gene and region of different 9 (RD9) by Polymerase Chain Reaction (PCR) to identify M. tuberculosis from the other species in Mycobacterium tuberculosis complex (MTBC) in the 79 clinical specimens which acid fast stain positive. Sixty-nine clinical specimens were Mycobacterium spp. and 10 were negative. From 69 clinical specimens, 61 were M. tuberculosis (77.22%), 5 were other species in MTBC (6.33%) and 3 were nontuberculous mycobacteria (NTM) (3.80%). The sensitivity of this method is 87.34% while the sensitivity of culture is 88.24%. The advantage of PCR is reliable and need 2 days to complete this process. It is indicated that PCR can rapidly identify M. tuberculosis and can use for the therapeutic process.