Evaluation of the geneXpert MTB/RIF assay for early diagnosis of tuberculosis and detection of rifampicin resistance in pulmonary and extrapulmonary specimens
Öz
Purpose: The emerging of multi-drug resistant strains of Mycobacterium tuberculosis complex and the resurgence of tuberculosis have forced new methods for diagnosis and antimicrobial susceptibility to be developed. In this study, we evaluated a recently marketed diagnostic technique, GeneXpert MTB/RIF test, in terms of identifying Mycobacterium tuberculosis complex and detecting rifampicin resistance from clinical samples.
Material and Methods: In our study, GeneXpert MTB/RIF assay was compared with conventional and automated culture methods. 389 various clinical samples (171 pulmonary and 218 ekstrapulmonary samples) were cultured with BACTEC MGIT 960 culture system and Löwenstein-Jensen medium and were tested with GeneXpert MTB / RIF test.
Results: 23 samples were positive for Mycobacterium tuberculosis complex by GeneXpert MTB/RIF test, but 22 samples were positive for Löwenstein-Jensen medium and BACTEC MGIT 960 culture system. 2 of 23 samples were detected rifampicin resistant at the first study, but re-studying of these samples resulted as rifampicin resistant for only one sample. According to culture findings of all pulmonary samples, the sensitivity and specificity for GeneXpert MTB / RIF test were both 100% (16/16). The sensitivity and specificity for extrapulmonary samples were 83.3% and 99.5%, respectively.
Conclusion: GeneXpert MTB / RIF test is an effectual automated molecular diagnostic technique with its successful and reliable performance in early diagnosis of tuberculosis and detecting multi-drug resistant strains.
Anahtar Kelimeler
Kaynakça
- World Health Organization (WHO). Global Tuberculosis Report 2015. WHO/HTM/TB/2015.22, 2015.
- Hillemann D, Rüsch-Gerdes S, Boehme C, Richter E. Rapid molecular detection of extrapulmonary tuberculosis by the automated GeneXpert MTB/RIF System. J Clin Microbiol. 2011;49:1202-5.
- Zignol M, van Gemert W, Falzon D, Jaramillo E, Blanc L, Raviglione M. Modernizing surveillance of antituberculosis drug resistance: from special surveys to routine testing. Clin Infect Dis. 2011;52:901-6.
- Zeka A, Taşbakan S, Çavuşoğu C. Evaluation of the GeneXpert MTB/RIF assay for rapid diagnosis of tuberculosis and detection of rifampin resistance in pulmonary and extrapulmonary specimens. J Clin Microbiol. 2011;49:4138–41.
- Moure R, Muñoz L, Torres M, Santin M, Martín R, Alcaide F. Rapid detection of mycobacterium tuberculosis complex and rifampin resistance in smear-negative clinical samples by use of an integrated real-time PCR method. J Clin Microbiol. 2011;49:1137–9.
- Bunsow E, Ruiz-Serrano MJ, LópezRoa P, Kestler M, Viedma DG, Bouza E. Evaluation of GeneXpert MTB/RIF for the detection of Mycobacterium tuberculosis and resistance to rifampin in clinical specimens. J Infect. 2013:68:338-43.
- Alvarez-Uria G, Azcona JM, Midde M, Naik PK, Reddy S, Reddy R. Rapid diagnosis of pulmonary and extrapulmonary tuberculosis in HIV-infected patients. comparison of LED fluorescent microscopy and the GeneXpert MTB/RIF assay in a district hospital in India. Tuberc Res Treat. 2012;2012:932862.
- Cepheid® 2015. Xpert® MTB/RIF Dx System Operator Manual. Cepheid, Sunnyvale, CA, ABD
- Lawn, S. D.; Nicol, M.P. Xpert® MTB/RIF assay: development, evaluation and implementation of a new rapid molecular diagnostic for tuberculosis and rifampicin resistance. Future microbial. 2011,6:1067-82.
- Kalokhe, A.S., Shafiq, M., Lee, J.C. et al., Multidrugresistant tuberculosis drug susceptibility and molecular diagnostic testing: a review of the literature. Am J Med Sci. 2013;345:143–8.
