Comparison of Conventional and Molecular Methods in the Detection of Mycobacterium tuberculosis in Clinically Suspected Samples of Tuberculosis

摘要

Impeded diagnosis in Tuberculosis may be a major cause of morbidity and mortality among particular group of patients, hence better methods are needed for the accurate detection of tuberculosis (TB) among both smear positive and smear negative cases. This study was aimed to compare conventional and molecular methods in detecting Mycobacterium tuberculosis among the clinically suspected cases of TB. A total of 100 clinically diagnosed TB patients were incorporated in this study. All the patients were either admitted or attending JSS Hospital, Mysore during the study period i.e., from January 2018- December 2018. Sputum, Gastric aspirate, Pleural fluid. Ascitic fluid. Pus discharge, CSF and Tissue samples were gathered for smear microscopy, culture (Lowenstein - Jensen medium) and PCR testing. The sensitivity of smear and PCR were compared to that of culture considering as gold standard. 50 of 100 patients were positive on smear microscopy. 51 specimens yielded the growth of Mycobacterium tuberculosison Lowenstein-Jensen's medium and PCR detected the presence of MTB specific gene in 77 specimens. In clinical diagnosis of tuberculosis, molecular methods are probably a useful adjunct certainly in smear negative paucibacillary cases. Early diagnosis ofTB is cornerstone for proper treatment and control of this deadly disease. Polymerase chain reaction testing is the most rapid and sensitive method for the diagnosis of tuberculosis while culture is specific but it takes 4 to 8 weeks to provide resultsand smear testing is the cheapest but least sensitive test.