Abstract
Five hundred fifty respiratory and nonrespiratory specimens from 340 patients were analyzed by comparing the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) with conventional culture, which was the method of reference, for the detection of the Mycobacterium tuberculosis complex. After resolution of discrepant results by retesting the samples and reviewing the patients' clinical histories, a total of 60 respiratory specimens were MTD and culture positive, 347 were MTD and culture negative, 4 were MTD positive and culture negative, and 1 was MTD negative and culture positive. This results in a sensitivity of 98.4%, a specificity of 98.9%, and positive and negative predictive values of 93.8 and 99.7%, respectively. Repeatedly, clinicians asked to test specimens of nonpulmonary origin by MTD. Although, MTD is not approved for use with nonrespiratory specimens, the following results were shown. Sixty-one pleural exudate specimens showed disappointing results (sensitivity, 20%). However, MTD performed well with another 77 nonrespiratory specimens; 17 samples were positive and 57 samples were negative by both MTD and culture. No false-negative results were found by MTD. Three MTD-positive, culture-negative specimens had high sample relative light unit/cutoff relative light unit ratios, strongly suggesting true tuberculosis. Positive microscopy and positive culture with MTD-negative results occurred 12 times. Those cultures showed atypical mycobacteria 11 times and Actinomyces species once. The stability of the reagents in the MTD kit was also assessed by testing reagents, including the enzyme mixture, kept at -70 degrees C for at least 6 months. No loss of activity was seen.
Full Text
The Full Text of this article is available as a PDF (214.4 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Andersen A. B., Thybo S., Godfrey-Faussett P., Stoker N. G. Polymerase chain reaction for detection of Mycobacterium tuberculosis in sputum. Eur J Clin Microbiol Infect Dis. 1993 Dec;12(12):922–927. doi: 10.1007/BF01992166. [DOI] [PubMed] [Google Scholar]
- De Wit D., Steyn L., Shoemaker S., Sogin M. Direct detection of Mycobacterium tuberculosis in clinical specimens by DNA amplification. J Clin Microbiol. 1990 Nov;28(11):2437–2441. doi: 10.1128/jcm.28.11.2437-2441.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ehlers S., Pirmann M., Zaki W., Hahn H. Evaluation of a commercial rRNA target amplification assay for detection of Mycobacterium tuberculosis complex in respiratory specimens. Eur J Clin Microbiol Infect Dis. 1994 Oct;13(10):827–829. doi: 10.1007/BF02111344. [DOI] [PubMed] [Google Scholar]
- Eisenach K. D., Cave M. D., Bates J. H., Crawford J. T. Polymerase chain reaction amplification of a repetitive DNA sequence specific for Mycobacterium tuberculosis. J Infect Dis. 1990 May;161(5):977–981. doi: 10.1093/infdis/161.5.977. [DOI] [PubMed] [Google Scholar]
- Hance A. J., Grandchamp B., Lévy-Frébault V., Lecossier D., Rauzier J., Bocart D., Gicquel B. Detection and identification of mycobacteria by amplification of mycobacterial DNA. Mol Microbiol. 1989 Jul;3(7):843–849. doi: 10.1111/j.1365-2958.1989.tb00233.x. [DOI] [PubMed] [Google Scholar]
- Hermans P. W., Schuitema A. R., Van Soolingen D., Verstynen C. P., Bik E. M., Thole J. E., Kolk A. H., van Embden J. D. Specific detection of Mycobacterium tuberculosis complex strains by polymerase chain reaction. J Clin Microbiol. 1990 Jun;28(6):1204–1213. doi: 10.1128/jcm.28.6.1204-1213.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jonas V., Alden M. J., Curry J. I., Kamisango K., Knott C. A., Lankford R., Wolfe J. M., Moore D. F. Detection and identification of Mycobacterium tuberculosis directly from sputum sediments by amplification of rRNA. J Clin Microbiol. 1993 Sep;31(9):2410–2416. doi: 10.1128/jcm.31.9.2410-2416.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KUBICA G. P., DYE W. E., COHN M. L., MIDDLEBROOK G. Sputum digestion and decontamination with N-acetyl-L-cysteine-sodium hydroxide for culture of mycobacteria. Am Rev Respir Dis. 1963 May;87:775–779. doi: 10.1164/arrd.1963.87.5.775. [DOI] [PubMed] [Google Scholar]
- Pfyffer G. E., Kissling P., Wirth R., Weber R. Direct detection of Mycobacterium tuberculosis complex in respiratory specimens by a target-amplified test system. J Clin Microbiol. 1994 Apr;32(4):918–923. doi: 10.1128/jcm.32.4.918-923.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pierre C., Lecossier D., Boussougant Y., Bocart D., Joly V., Yeni P., Hance A. J. Use of a reamplification protocol improves sensitivity of detection of Mycobacterium tuberculosis in clinical samples by amplification of DNA. J Clin Microbiol. 1991 Apr;29(4):712–717. doi: 10.1128/jcm.29.4.712-717.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Soini H., Skurnik M., Liippo K., Tala E., Viljanen M. K. Detection and identification of mycobacteria by amplification of a segment of the gene coding for the 32-kilodalton protein. J Clin Microbiol. 1992 Aug;30(8):2025–2028. doi: 10.1128/jcm.30.8.2025-2028.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wolinsky E. Statement of the Tuberculosis Committee of the Infectious Diseases Society of America. Clin Infect Dis. 1993 May;16(5):627–628. doi: 10.1093/clind/16.5.627. [DOI] [PubMed] [Google Scholar]