Detection Of DNA Extracted From Mycobacterium Tuberculosis By TaqMan-PCR Technique And Its Clinical Application

To evaluate the clinical diagnostic value of TaqMan-PCR technique in the diagnosis of active pulmonary tuberculosis, we detected DNA of M. tb in the specimens of sputum and peripheral blood obtained from 168 patients with active pulmonary tuberculosis, 57 patients with lung cancer and peripheral blood from 34 healthy individuals by TaqMan-PCR and PCR simultaneously. The specimens of sputum were also detected by smear examination, culture with BACTEC and Lowenstein-Jensen for tubercle bacillus.The results showed that: The positive rates of sputum and peripheral blood detected by TaqMan-PCR were 53.0% and 61.3%, respectively, significant higher than those of PCR, smear, culture with BACTEC and Lowenstein-Jensen (P<0.05). There was no significant difference between TaqMan-PCR and PCR for specificity (P>0.05). Of 105 specimens of peripheral blood from patients with smear-negative and/or culture-negative pulmonary tuberculosis, 48 specimens of peripheral blood detected by TaqMan-PCR were positive. The positive rates were 45.7%.It was showed that TaqMan-PCR method was an useful tool for pulmonary tuberculosis with higher sensitivity and specificity, particularly for smear-negative and/or culture-negative pulmonary tuberculosis.