Open AccessPCR amplification of shorter fragments from the devR ( Rv3133c ) gene significantly increases the sensitivity of tuberculosis diagnosis
Author(s) -
Chakravorty Soumitesh,
Pathak Divya,
Dudeja Mridu,
Haldar Sagarika,
Hanif M.,
Tyagi Jaya Sivaswami
Publication year - 2006
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2006.00187.x
Subject(s) - mycobacterium tuberculosis , sputum , tuberculosis , microbiology and biotechnology , gene , biology , polymerase chain reaction , dna , genetics , medicine , pathology
This study was designed to assess the vital issue of gene target length and PCR assay performance in relation to the detection of Mycobacterium tuberculosis in clinical specimens. Two PCR assays that amplify fragments of varying lengths from the devR gene of M. tuberculosis were evaluated. Using M. tuberculosis DNA the ‘short‐length’ PCR assay detected 250–500 genome equivalents vs. 500–1000 genome equivalents by the ‘long‐length’ assay. In comparison to a highly sensitive smear microscopy test (universal sample processing smear), the sensitivity of the ‘short‐length’ assay was 97.8% vs. 69.9% of the ‘long‐length’ assay in sputum specimens ( n =506) from patients being evaluated for a possible diagnosis of tuberculosis. The 27.9% absolute increase in sensitivity was statistically significant ( P <0.001). Our results indicate that in a clinical setting when all other conditions are equal, the amplification of a shorter gene fragment of devR increases the sensitivity and efficiency of the PCR assay in spite of using a single copy gene as target.