Direct Nitrate Reductase Assay: Rapid Detection of MDR-TB in Low Resource Settings
Authors/Creators
- 1. Department of Microbiology, NKP Salve Institute of Medical Sciences & Research Centre, Nagpur - 440019
Description
Conventional methods based on measurement of growth in culture media containing antibiotics are available for detection of drug resistance in Mycobacterium Tuberculosis requiring several weeks for results. Newer methods like BACTEC are costly. Hence a simple and rapid alternative method of Nitrate Reductase Assay (NRA) was used in this study to detect resistance to Isoniazid (INH) and Rifampicin (RIF). Sputum samples were collected from patients attending DOTS centre at NKPSIMS from July 2012 to May 2013. Smear AFB Positive samples were only included. After decontamination, 112 sputum were inoculated on plain LJ and 3 Middle Brook 7H9 media (One Plain MB with KNO3, one with KNO3 and INH, one with KNO3 and RIF). Nitrate reduction was tested on Days 7, 10, 14 and 18 of incubation. Control strain H37Rv was used as positive control for nitrate reduction. Eleven samples were contaminated. NRA was performed on 101 samples. Fourteen were resistant to INH, whereas 6 were resistant to RIF and INH. Maximum (46) samples were nitrate positive on day 14. Twenty Eight and 22 samples were positive on day 10 and day 18 respectively. Positivity was seen as early as 7th day in only 5 samples. The present study concludes that this test, being easy, rapid, simple and time saving, can be applied directly on sputum positive patients without waiting for the culture. Thus, NRA can be used as rapid detection test for MDRTB cases in low resource settings.
Files
33-35.pdf
Files
(32.4 kB)
| Name | Size | Download all |
|---|---|---|
|
md5:54aea8edf4c47568f0de34cf55c1fb63
|
32.4 kB | Preview Download |
Additional details
References
- 1. Gupta M, Shamma, Singh NP, Kaur IR. Evaluation of nitrate reductase assay for direct detection of drug resistance in Mycobacteriom tuberculosis: Rapid and inexpensive method for low-resource settings. IJMM. 2010;28(4):363-5.
- 2. Lemus D, Montoro E, EchemendÕa M, Martin A, Portaels F, Palomino JC. Nitrate reductase assay for direct detection of drug resistance in Mycobacteriom tuberculosis: simple and inexpensive method for lowresource laboratories. J Med Microbiol. 2006;55:861- 863
- 3. Affolabi D, Odoun M, Martin A, Palomino JC, Anagonou S, Portaels F. Evaluation of Direct Detection of Mycobacterium tuberculosis Rifampicin resistance by a Nitrate Reductase Assay applied to sputum samples in Cotonou, Benin. J Clin Microbiol. 2007;2123-2125.
- 4. Syre H, Phyu S, Sandven P, Bjorvatn B, Grewal HMS. Rapid colorometric method for testing susceptibility of Mycobacterium tuberculosis to Isoniazid and Rifampin in Liquid cultures. J Clin Microbiol. 2003;41(11):5173-5177.
- 5. Musa HR, Ambroggi M, Souto A, Angeby KA. Drug susceptibility testing of Mycobacterium tuberculosis by a nitrate reductase assay applied directly on microscopy-positive sputum samples. J Clin Microbiol. 2005;43:3159-3561.
- 6. Solis LA, Shin LA, Han LL, Llanos F, Stowell M, Sloutsky A. Validation of a rapid method for detection of M. tuberculosis resistance to isoniazid and rifampin in Lima, Peru. Int J Tuberc Lung Dis. 2005;9:760-764.
- 7. Heifets L, Linder T, Sanchez T, Spencer D, Brennan J. Two liquid medium systems,Mycobateria Growth Indicator Tube and MB Redox Tube,for Mycocterium tuberculosis isolation from sputum specimens. J Clin Microbiol 2000;38(3):1227-1230.
- 8. Mishra B, Muralidharan S, Srinivasa H. Direct drug susceptibility testing of Mycobacterium tuberculosis to primary anti tubercular drugs by nitrate reductase assay.Indian J Patho Microbiol. 2009;52(3):343-344.
- 9. Shruti SS, Pratibha BD. The Nitrate Reductase Assay in the Rapid Detection of Multidrug-Resistant and Extensively Drug- Resistant Tuberculosis in South Gujarat, India. IJSR. 2008;5(6):48-51.
- 10. Huang ZK, Luo Q, Qing C, Deng YT, Xiong GL, Li JM. Evaluation of the direct nitrate reductase assay for rapid detection of extensively drug-resistant tuberculosis. Int J Tuberc Lung Dis. 2016;20(4):468- 473.
- 11. Martin A, Panaiotov S, Portaels F, Hoffner S, Palomino JC, Angeby K. The nitrate reductase assay for the rapid detection of isoniazid and rifampicin resistance in Mycobacteruim tuberculosis:a systematic review and meta-analysis. J Antimicrob Chemother. 2008;62:56- 65.