Preliminary evaluation of the Cobas Taqman real-time PCR for Mycobacterium tuberculosis detection in clinical specimens

Abstract number: R2171

Agüero J., Fernández-Mazarrasa C., Ruíz de Alegría C., Martínez-Martínez L.

Objective: We have evaluated the commercially available Cobas Taqman MTB Test, Roche, which is a new released Real Time PCR test for qualitative detection of Mycobacterium tuberculosis complex DNA in human respiratory specimens. Our objective was to evaluate the test in both pulmonary and extrapulmonary clinical samples, and to compare the results with those derived from microscopy and our current routine Real Time PCR assay for M. tuberculosis (RealArt M. tuberculosis TM PCR, Abbott)

Methods: Using the results from Coletsos culture as gold standard we evaluated the sensitivities and the predictive values of the three techniques in 112 samples: 89 respiratory specimens (37 sputum, 28 bronchial aspirates, 14 pleural fluids, 9 bronchial lavages and one protected specimen brush) and 24 nonrespiratory specimens (12 cerebrospinal fluids, 7 exudates and 5 tissue specimens)

Results: The overall results of microscopy, RealArt and Cobas Taqman were: 63%, 85.2% and 81.5% for sensitiviy; 89.5%, 88.5% and 88% for positive predictive value; and 89.4%, 95.4% and 94.3% for negative predictive value, respectively. This last value was higher than 95% for the three techniques in nonrespiratory samples. As described, sensitivities of molecular techniques were considerably lower for smear negative specimens (63.6% and 54.5% for RealArt and Cobas Taqman, respectively)

Conclusions: The Cobas Taqman MTB assay is easy to perform and provides a valuable diagnostic tool for rapid detection of the M. tuberculosis directly from clinical samples

Session Details

Date: 16/05/2009
Time: 00:00-00:00
Session name: 19th European Congress of Clinical Microbiology and Infectious Diseases
Location: Helsinki, Finland, 16 - 19 May 2009
Presentation type:
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