Diagnosis of Mycobacterium tuberculosis by Using PCR and Comparison it With Ziehl Neelsen Staining and Mantoux Test

Nucleic acid amplification and detection methods developed in the past decade are useful for the diagnosis and management of a variety of infectious diseases. The most widely used of these methods is the polymerase chain reaction (PCR). Commercial PCR assays for the diagnosis of tuberculosis are now routinely used in many diagnostic laboratories. 126 sputum samples were collected from 126 subjects who went through tuberculin skin test. The samples were processed for detection of Mycobacterium tuberculosis by ZN staining and PCR. The results showed that the rate of positivity with PCR was 105/126 (83.33%), while it was 75/126 (59.5%) with microscopy, and the TST showed very low percentage of positivity in comparison to other tests performed for detection of tuberculosis i.e. 30/126 (23.8%). The results of the present study provided the similar evidence about the importance of PCR in detection of Mycobacterium tuberculosis. This also suggests that the use PCR can be significant in the early diagnosis of pulmonary and extra pulmonary tuberculosis.