Evaluation of nested PCR targeting IS6110 of Mycobacterium tuberculosis for the diagnosis of pulmonary and extra-pulmonary tuberculosis

摘要

The purpose of this study was to compare sensitivity and specificity of the PCR from smear and culture in the diagnosis of suspected cases of pulmonary and extra pulmonary tuberculosis. This study was carried out on 140 specimens obtained from suspected cases of tuberculosis. The various specimens collected from these patients included 74 sputum, 38 endometrial biopsies, 16 CSF and 12 gastric aspirates. All the specimens were tested by ZN staining, culture was on L-J medium and PCR was performed for targeting IS6110 sequence. Out of 140 patients, 61.4% were suffering from pulmonary tuberculosis and 38.5% from extra-pulmonary tuberculosis. In these 140 patients, 40 (28.5%) were ZN smear positive for AFB, 48 (34.2%) were culture positive for AFB and 104 (74.2%) were sensitive to nested PCR for Mycobacterium tuberculosis. We observed significant difference in sensitivity of PCR for smear positive and negative cases, and also for culture positive and negative cases