Evaluation of GeneXpert MTB/RIF for the detection of Mycobacterium tuberculosis and resistance to rifampin in clinical specimens
Summary Objectives GeneXpert (GX) is a novel real-time polymerase chain reaction assay for the simultaneous detection of Mycobacterium tuberculosis (MTB) and resistance to rifampin (RIF). We evaluated the performance of GX for direct detection of MTB in respiratory and non-respiratory specimens and...
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Published in: | The Journal of infection Vol. 68; no. 4; pp. 338 - 343 |
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Main Authors: | , , , , , |
Format: | Journal Article |
Language: | English |
Published: |
Amsterdam
Elsevier Ltd
01-04-2014
Elsevier |
Subjects: | |
Online Access: | Get full text |
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Summary: | Summary Objectives GeneXpert (GX) is a novel real-time polymerase chain reaction assay for the simultaneous detection of Mycobacterium tuberculosis (MTB) and resistance to rifampin (RIF). We evaluated the performance of GX for direct detection of MTB in respiratory and non-respiratory specimens and assessed the ability of the assay to detect resistance to RIF in non-tuberculosis (TB) endemic country. Methods We analyzed 595 clinical samples in a 1550-bed tertiary hospital in Madrid, Spain. Specimens were processed using GX, auramine smear, conventional culture, and drug phenotypic susceptibility testing (DST) with MGIT SIRE (BD). Results Of the 595 clinical samples, 305 (51.3%) were non-respiratory and 290 (48.7%) were respiratory. In total, MTB was isolated in 81 specimens, 71 of which were positive with GX. The sensitivity, specificity, PPV, and NPV of the GX were: 97.1%, 98.6%, 95.7% and 99.1% for respiratory samples and 33.3%, 99.7%, 80.0% and 97.3% for non-respiratory. GX detected 8 RIF-resistant samples, but only 5 were confirmed by DST. Conclusions GX is an accurate, easy-to-apply and rapid test to detect MTB, especially in smear-positive respiratory samples. Although is a useful tool for the rapid identification of RIF-resistant MTB strains, the rifampin resistant results should be confirmed by DST. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0163-4453 1532-2742 |
DOI: | 10.1016/j.jinf.2013.11.012 |