Validation of in House PCR Using IS6110 for Detection of M. tuberculosis and Its Comparison with ZN Staining, Cultures and RT PCR Kit Methods

A polymerase chain reaction (PCR) assay for the rapid detection of Mycobacterium tuberculosis in sputum samples was studied. The target DNA of 123 base pair bp fragment of IS6110 which was repeated in the M. tuberculosis genome and was highly specific for the M. tuberculosis complex. PCR was positive in all 51 smear and culture-positive samples, in 17 of 17 smear-negative and culture-positive samples, 8 of 132 smear and culture negative samples. The overall sensitivity and specificity were 84 and 94%. Rapid detection of MTB using commercial diagnostic systems is limited by their costs and/or their requirement of specific equipment. The Genosens’s MTB Complex/MOTT Qualitative Real Time PCR assay kit for direct detection of M. tuberculosis complex in pulmonary tuberculosis samples have been used in MGM CRL on routine basis and also compatible with Light Cycle 480 Real time PCR Instrument. Conventional polymerase chain reaction has a much higher sensitivity than microscopy and can facilitate therapeutic decisions for those with suspected pulmonary tuberculosis. Thus, IS6110 as a PCR target was found to be very useful for rapid diagnosis of M. tuberculosis infection and start of antituberculous chemotherapy.