摘要:
45 ABSTRACT 46 Background: The Epistem Genedrive(R) assay rapidly detects Mycobacterium tuberculosis 47 complex from sputum and is currently available for clinical use. However, the analytical and 48 clinical performance of this test has not been fully evaluated. 49 Methods: The analytical limit of detection (LOD) of the Genedrive PCR amplification was 50 tested with genomic DNA; performance of the complete (sample processing plus 51 amplification) system was tested by spiking M. tuberculosis mc26030 cells into distilled water 52 and M. tuberculosis-negative sputum. Specificity was tested using common respiratory 53 pathogens and non-tuberculosis mycobacteria. A clinical evaluation enrolled adults with 54 suspected pulmonary tuberculosis, obtained three sputa from each participant, and 55 compared Genedrive accuracy to that of the Xpert MTB/RIF assay, using M. tuberculosis 56 cultures as the reference standard. 57 Results: The Genedrive assay had an LOD of 1pg/l (100 genomic DNA copies/reaction). 58 The LOD of the system was 2.5x104CFU/mL and 2.5x105CFU/mL for cells spiked into water 59 and sputum, respectively. False positive rpoB probe signals were observed in 3/32(9.4%) 60 negative controls as well as for M. abscessus, M. gordonae and M. thermoresistibile. In the 61 clinical study, among 336 analyzed participants, overall sensitivities for tuberculosis case 62 detection of Genedrive, Xpert and smear microscopy were 45.4% (95%CI: 35.2, 55.8), 63 91.8% (95%CI: 84.4, 96.4) and 77.3% (95%CI: 67.7, 85.2) respectively. Sensitivities of 64 Genedrive and Xpert for detection of smear microscopy-negative tuberculosis were 0% 65 (95%CI: 0, 15.4) and 68.2% (95%CI: 45.1, 86.1) respectively.
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