Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 1998 Jul;36(7):2023-9.
doi: 10.1128/JCM.36.7.2023-2029.1998.

Comparison of Roche Cobas Amplicor Mycobacterium tuberculosis assay with in-house PCR and culture for detection of M. tuberculosis

B R Eing  1 , A Becker, A Sohns, R Ringelmann
Affiliations
Comparative Study

Comparison of Roche Cobas Amplicor Mycobacterium tuberculosis assay with in-house PCR and culture for detection of M. tuberculosis

B R Eing et al. J Clin Microbiol. 1998 Jul.

Abstract

The new Roche Cobas Amplicor Mycobacterium tuberculosis assay, which is a semiautomated version of the manually performed Roche Amplicor M. tuberculosis test, was compared to culture and an IS6110-based in-house PCR protocol. A total of 1,681 specimens from 833 patients, including specimen types other than sputum, were tested in parallel by both the in-house PCR and the Cobas Amplicor M. tuberculosis assay. After we resolved discrepant PCR results, the sensitivity, specificity, and positive and negative predictive values for the Cobas Amplicor M. tuberculosis assay were 66.33, 99.71, 94.36, and 97.66%, respectively. The corresponding values for the in-house PCR were 91.08, 99.85, 97.87, and 99.37%, respectively. For culture- and smear-positive specimens, the sensitivity of the Cobas Amplicor M. tuberculosis test was 96.42% (in-house PCR, 100%). If only smear-negative sputum specimens were considered, the Cobas Amplicor M. tuberculosis assay exhibited a sensitivity of 45.45% (in-house PCR, 63.63%) relative to that of culture. With a modified protocol for DNA extraction (washing of samples plus ultrasonication), both PCR methods performed better with gastric aspirates than with sputum samples (sensitivity of the Cobas Amplicor M. tuberculosis assay with smear-negative gastric aspirates, 70.00%; sensitivity of in-house PCR, 90.00%). With dithiothreitol being used for liquefaction of specimens in this study, the Cobas Amplicor M. tuberculosis assay exhibited an inhibition rate of 9.16%. In our view, the new Cobas Amplicor M. tuberculosis test (i) is well suited for typing of smear-positive specimens, (ii) may also be applied to gastric aspirates and other types of specimens if DNA extraction methods are modified appropriately, and (iii) exhibits a sensitivity with smear-negative sputum specimens which makes it recommendable that a minimum of three samples from the same patient be tested.

PubMed Disclaimer

Figures

FIG. 1
FIG. 1
Results of conventional testing of noninhibitory specimens.
See this image and copyright information in PMC

References

    1. Abe C, Hirano K, Wada M, Kazumi Y, Takahashi M, Fukasawa Y, Yoshimura T, Miyagi C, Goto S. Detection of Mycobacterium tuberculosis in clinical specimens by polymerase chain reaction and Gen-Probe Amplified Mycobacterium tuberculosis Direct Test. J Clin Microbiol. 1993;31:3270–3274. - PMC - PubMed
    1. Beavis K G, Lichty M B, Jungkind D L, Giger O. Evaluation of Amplicor PCR for direct detection of Mycobacterium tuberculosis from sputum specimens. J Clin Microbiol. 1995;33:2582–2586. - PMC - PubMed
    1. Bennedsen J, Thomsen V O, Pfyffer G E, Funke G, Feldman K, Beneke A, Jenkins P A, Hegginbothom M, Fahr A, Hengstler M, Cleator G, Klapper P, Wilkins E G L. Utility of PCR in diagnosing pulmonary tuberculosis. J Clin Microbiol. 1996;34:1407–1411. - PMC - PubMed
    1. Bergmann J S, Woods G L. Clinical evaluation of the Roche AMPLICOR PCR Mycobacterium tuberculosis test for detection of M. tuberculosis in respiratory specimens. J Clin Microbiol. 1996;34:1083–1085. - PMC - PubMed
    1. Bodmer T, Gurtner A, Scholkmann M, Matter L. Evaluation of the COBAS AMPLICOR MTB system. J Clin Microbiol. 1997;35:1604–1605. - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources