scholarly journals Comparative Evaluation of the New Gen-Probe Mycobacterium tuberculosis Amplified Direct Test and the Semiautomated Abbott LCx Mycobacterium tuberculosis Assay for Direct Detection of Mycobacterium tuberculosis Complex in Respiratory and Extrapulmonary Specimens

1998 ◽  
Vol 36 (12) ◽  
pp. 3601-3604 ◽  
Author(s):  
Claudio Piersimoni ◽  
Annapaola Callegaro ◽  
Claudio Scarparo ◽  
Valeria Penati ◽  
Domenico Nista ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Tuberculosis Complex ◽  
Direct Detection ◽  
Extrapulmonary Tuberculosis ◽  
Nucleic Acid Amplification ◽  
Tuberculosis Complex ◽  
Predictive Values ◽  
Clinical Specimens ◽  
Respiratory Specimens ◽  
Level Of Agreement

Two commercial assays that detect Mycobacterium tuberculosis complex (MTB) in clinical specimens by rRNA target amplification (AMTDII) and ligase chain reaction (LCx) were evaluated. The tests were applied to 457 respiratory (n = 273) and extrapulmonary (n = 184) specimens collected from 357 patients. The results were compared with those of acid-fast staining and culture. The combination of culture and clinical diagnosis was considered to be the “gold standard.” Seventy specimens were from patients with pulmonary tuberculosis and 28 specimens were from patients with extrapulmonary tuberculosis. After resolution of discrepant results, the overall sensitivities, specificities, and positive and negative predictive values for respiratory specimens were 92.8, 99.4, 98.5, and 97%, respectively, for AMTDII and 75.7, 98.8, 96.4, and 90.5%, respectively, for LCx. With extrapulmonary specimens, the overall sensitivities, specificities, and positive and negative predictive values were 78.6, 99.3, 95.6, and 96.2%, respectively, for AMTDII and 53.6, 99.3, 93.7, and 92.1%, respectively, for LCx. The level of agreement between AMTDII and LCx assay results was 78.2%. We conclude that although both nucleic acid amplification methods are rapid and specific for the detection of MTB in clinical specimens, AMTDII is significantly more sensitive than LCx with both respiratory (P = 0.005) and extrapulmonary (P = 0.048) specimens.

scholarly journals Evaluation of Three Nucleic Acid Amplification Methods for Direct Detection of Mycobacterium tuberculosis Complex in Respiratory Specimens

1999 ◽  
Vol 37 (6) ◽  
pp. 1932-1934 ◽  
Author(s):  
S. X. Wang ◽  
L. Tay
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nucleic Acid ◽  
Mycobacterium Tuberculosis Complex ◽  
Direct Detection ◽  
Nucleic Acid Amplification ◽  
Smear Microscopy ◽  
Direct Test ◽  
Tuberculosis Complex ◽  
Chain Reaction ◽  
Respiratory Specimens

Two hundred thirty respiratory specimens from 230 patients were analyzed by using COBAS AMPLICOR PCR, Amplified Mycobacterium tuberculosis Direct Test, and ligase chain reaction methods. Results were compared with those of smear microscopy and radiometric culture (Bactec) methods. No significant differences were observed among the results of the three methods, which are acceptable for direct detection of M. tuberculosis complex in respiratory specimens.

Evaluation of the Enhanced Amplified Mycobacterium Tuberculosis Direct Test for Direct Detection of Mycobacterium tuberculosis Complex in Respiratory Specimens

1999 ◽  
Vol 123 (11) ◽  
pp. 1101-1103 ◽  
Author(s):  
Michael B. Smith ◽  
John S. Bergmann ◽  
Michelle Onoroto ◽  
Greg Mathews ◽  
Gail L. Woods
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nontuberculous Mycobacteria ◽  
Direct Detection ◽  
Direct Test ◽  
Tuberculosis Complex ◽  
Predictive Values ◽  
Smear Negative ◽  
Sensitivity Specificity ◽  
Culture Positive ◽  
Respiratory Specimens

Abstract Objective.—To evaluate the performance of the enhanced Mycobacterium Tuberculosis Direct Test (E-MTD), for the direct detection of M tuberculosis complex (MTBC) in respiratory specimens. Design.—Two hundred seventy-four respiratory specimens from 151 patients in respiratory isolation were tested with the E-MTD, and the results were compared with the results of mycobacterial smear, culture, and the earlier form of the test, MTD-1. Results.—Forty-one specimens were culture positive for mycobacteria (20 MTBC and 21 nontuberculous mycobacteria), 23 of which were smear positive (16 MTBC, 7 nontuberculous mycobacteria). Twenty-four specimens were positive by E-MTD, and 21 were positive by MTD-1. Of the 20 MTBC culture-positive specimens, 19 were positive by the E-MTD and 19 were positive by the MTD-1. The remaining specimens were MTBC negative by all methods. After resolution of discrepancies, the sensitivity, specificity, and positive and negative predictive values were 95.2%, 100%, 100%, 99.6% for the MTD-1 and 95.2%, 98.8%, 87.0%, and 99.6%, for the E-MTD. For the E-MTD smear-positive and smear-negative specimens, these same values were 93.8%, 100%, 100%, and 87.5% and 100%, 98.8%, 62.5%, and 100%, respectively. Conclusion.—The results suggest that the E-MTD is a reliable method for the direct detection of MTBC in smear-positive respiratory specimens.

scholarly journals Rapid Diagnosis of Pulmonary Tuberculosis with the LCx Mycobacterium tuberculosis Assay and Comparison with Conventional Diagnostic Techniques

1998 ◽  
Vol 36 (10) ◽  
pp. 3046-3047 ◽  
Author(s):  
Peter Rohner ◽  
Esther I. M. Jahn ◽  
Beatrice Ninet ◽  
Concetta Ionati ◽  
Rainer Weber ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Direct Detection ◽  
Diagnostic Techniques ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Predictive Values ◽  
Amplification Assay ◽  
Sensitivity Specificity ◽  
Culture Positive ◽  
Respiratory Specimens

The LCx MTB amplification assay is a nucleic acid amplification test intended for the direct detection ofMycobacterium tuberculosis complex in respiratory specimens. We evaluated its performance on 2,001 consecutive respiratory specimens; 78 were culture positive for M. tuberculosis. Sensitivity, specificity, and positive and negative predictive values of this assay for all specimens compared to culture results were 88.5, 97.7, 60.5, and 99.5%, respectively. When referred to resolved clinical diagnosis of active tuberculosis, these values improved to 90.2, 98.4, 72.8, and 99.5%, respectively.

scholarly journals Comparative Evaluation of Initial and New Versions of the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test for Direct Detection of Mycobacterium tuberculosis in Respiratory and Nonrespiratory Specimens

1998 ◽  
Vol 36 (3) ◽  
pp. 684-689 ◽  
Author(s):  
Fredy Gamboa ◽  
Gregorio Fernandez ◽  
Eduardo Padilla ◽  
José M. Manterola ◽  
Joan Lonca ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Direct Detection ◽  
Turnaround Time ◽  
Nucleic Acid Amplification ◽  
Clinical Samples ◽  
Direct Test ◽  
Predictive Values ◽  
Staining Methods ◽  
Sensitivity Specificity ◽  
Respiratory Specimens

We evaluated the initial version of the Amplified Mycobacterium Tuberculosis Direct Test (Gen-Probe) (AMTDT 1) and the new version of AMTDT (AMTDT 2) for the detection of Mycobacterium tuberculosis directly from respiratory and nonrespiratory samples and compared the results with those of culture and staining methods. The assays were applied to 410 respiratory and 272 nonrespiratory samples collected from 515 patients. The combination of the culture results and clinical diagnosis was considered to be the “gold standard.” Ninety-five respiratory specimens were collected from 67 patients with a diagnosis of pulmonary tuberculosis (TB) and 68 nonrespiratory specimens were collected from 61 patients with a diagnosis of extrapulmonary TB. With respiratory specimens, the sensitivity, specificity, and positive and negative predictive values were 83, 100, 100, and 96%, respectively, for AMTDT 1 and 94.7, 100, 100, and 98.4%, respectively, for AMTDT 2. With nonrespiratory specimens, the sensitivity, specificity, and positive and negative predictive values were 83, 100, 100, and 94%, respectively, for AMTDT 1 and 86.8, 100, 100, and 98.4%, respectively, for AMTDT 2. The overall results of AMTDT 1 and AMTDT 2 were concordant for 97% (661 of 682) of the samples. Statistically significant differences in sensitivities were found between AMTDT 1 and AMTDT 2 with respiratory specimens. It was concluded that although both nucleic acid amplification methods are rapid, sensitive, and specific for the detection of M. tuberculosis complex in all types of clinical samples, AMTDT 2 appeared to be more sensitive than AMTDT 1 when applied to smear-negative specimens. In contrast AMTDT 2 is more susceptible than AMTDT 1 to inhibitory substances in the amplification reaction. The turnaround time of AMTDT 2 is shorter (3.5 h) than that for AMTDT 1 (5 h).

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