Use of Colorimetric Culture Methods for Detection of Mycobacterium Tuberculosis Complex Isolates from Sputum Samples in Resource-Limited Settings
De Beaudrap, P
AffiliationEpicentre Mbarara, Mbarara, Uganda. email@example.com
MetadataShow full item record
JournalJournal of Clinical Microbiology
AbstractDespite recent advances, tuberculosis (TB) diagnosis remains imperfect in resource-limited settings due to its complexity and costs, poor sensitivity of available tests, or long times to reporting. We present a report on the use of colorimetric methods, based on the detection of mycobacterial growth using colorimetric indicators, for the detection of Mycobacterium tuberculosis in sputum specimens. We evaluated the nitrate reductase assay (NRA), a modified NRA using para-nitrobenzoic acid (PNB) (NRAp), and the resazurin tube assay using PNB (RETAp) to differentiate tuberculous and nontuberculous mycobacteria. The performances were assessed at days 18 and 28 using mycobacterium growth indicator tube (MGIT) and Löwenstein-Jensen (LJ) medium culture methods as the reference standards. We enrolled 690 adults with suspected pulmonary tuberculosis from a regional referral hospital in Uganda between March 2010 and June 2011. At day 18, the sensitivities and specificities were 84.6% and 90.0% for the NRA, 84.1% and 92.6% for the NRAp, and 71.2% and 99.3% for the RETAp, respectively. At day 28, the sensitivity of the RETAp increased to 82.6%. Among smear-negative patients with suspected TB, sensitivities at day 28 were 64.7% for the NRA, 61.3% for the NRAp, and 50% for the RETAp. Contamination rates were found to be 5.4% for the NRA and 6.7% for the RETAp, compared with 22.1% for LJ medium culture and 20.4% for MGIT culture. The median times to positivity were 10, 7, and 25 days for colorimetric methods, MGIT culture, and LJ medium culture,respectively. Whereas the low specificity of the NRA/NRAp precludes it from being used for TB diagnosis, the RETAp might provide an alternative to LJ medium culture to decrease the time to culture results in resource-poor settings.
- The manual mycobacteria growth indicator tube and the nitrate reductase assay for the rapid detection of rifampicin resistance of M. Tuberculosis in low resource settings.
- Authors: Adikaram CP, Perera J, Wijesundera SS
- Issue date: 2012 Nov 27
- A continuously monitored colorimetric method for detection of Mycobacterium tuberculosis complex in sputum.
- Authors: Rojas-Ponce G, Rachow A, Guerra H, Mapamba D, Joseph J, Mlundi R, Marimoto S, Ntinginya NE, Mangu C, Framhein A, Butler A, Kohlenberg A, Ngatemelela D, Froeschl G, Maboko L, Hoelscher M, Heinrich N
- Issue date: 2013 Dec
- Direct nitrate reductase assay versus microscopic observation drug susceptibility test for rapid detection of MDR-TB in Uganda.
- Authors: Bwanga F, Haile M, Joloba ML, Ochom E, Hoffner S
- Issue date: 2011 May 9
- Performance of Mycobacterium Growth Indicator Tube BACTEC 960 with Lowenstein-Jensen method for diagnosis of Mycobacterium tuberculosis at Ethiopian National Tuberculosis Reference Laboratory, Addis Ababa, Ethiopia.
- Authors: Diriba G, Kebede A, Yaregal Z, Getahun M, Tadesse M, Meaza A, Dagne Z, Moga S, Dilebo J, Gudena K, Hassen M, Desta K
- Issue date: 2017 May 10
- Field evaluation of the direct detection of multidrug resistant Mycobacterium tuberculosis by nitrate reductase assay on 7H11 agar.
- Authors: Satti L, Ikram A, Palomino JC, Martin A, Khan FA
- Issue date: 2013 May