Direct detection of isoniazid resistant mycobacterium tuberculosis in respiratory specimens by real time PCR

2016 ◽  
Author(s):  
Chiu-man Shek
2013 ◽  
Vol 62 (8) ◽  
pp. 1160-1164 ◽  
Author(s):  
Meng-Rui Lee ◽  
Kuei-Pin Chung ◽  
Hao-Chien Wang ◽  
Chih-Bin Lin ◽  
Chong-Jen Yu ◽  
...  

The Cobas TaqMan MTB assay is a real-time PCR (qPCR) kit for rapid detection of Mycobacterium tuberculosis from clinical specimens. There are, however, limited studies validating its performance. We performed a prospective study in two hospitals in Taiwan on 586 respiratory specimens. By using culture as the reference method, the sensitivity and specificity of the Cobas TaqMan MTB assay were found to be 82.7 and 96.5 %, respectively. The sensitivity of the Cobas TaqMan MTB assay in acid-fast stain-negative respiratory specimens was only 34.9 %. Five specimens from five patients were positive for M. tuberculosis by the Cobas TaqMan MTB assay but were negative for M. tuberculosis by conventional culture methods. A diagnosis of pulmonary tuberculosis (TB) was made based on clinical and radiological findings as well as the response to anti-TB treatment in these five patients. Addition of data from these five specimens with discrepant results (PCR vs culture) from patients with symptoms clinically compatible with TB increased the sensitivity of the Cobas TaqMan MTB assay to 83.1 %. The Cobas TaqMan MTB assay is a rapid identification tool with a high degree of specificity for the direct detection of M. tuberculosis in respiratory specimens. The sensitivity for detecting acid-fast smear-negative respiratory specimens, however, is low.


2018 ◽  
Vol 71 (9) ◽  
pp. 774-780 ◽  
Author(s):  
Jeong-Uk Kim ◽  
Dae-Shick Ryu ◽  
Choong-Hwan Cha ◽  
Seon-Hee Park

AimsMycobacterium tuberculosis and non-tuberculous mycobacteria (NTM) are clinically different, and the rapid detection and differentiation of M. tuberculosis complex (MTBC) and NTM is crucial for patient management and infection control. Given the slow growth of most pathogenic mycobacteria, nucleic acid amplification assays are excellent tools for direct identification of mycobacteria in clinical specimens. Recently, a multiplex real-time PCR assay was developed that can directly detect 20 mycobacterial species in clinical specimens. Here, we evaluated the diagnostic performance of the assay for diagnosing mycobacterial disease under routine laboratory conditions.MethodsA total of 3334 specimens collected from 1437 patients suspected of tuberculosis infection were subjected to acid-fast bacilli staining, conventional culture and the multiplex real-time PCR assay. To evaluate the sensitivity and specificity of the assay, the overall diagnosis of tuberculosis was defined by positive culture plus medical history, and the 2007 American Thoracic Society and Infectious Disease Society of America diagnostic criteria for NTM disease were applied.ResultsThe sensitivity, specificity, positive predictive value and negative predictive value were 87.5%, 99.6%, 96.1% and 98.5%, respectively, for the detection of MTBC isolates and 53.3%, 99.9%, 95.2%, and 98.9%, respectively, for detecting NTM isolates.ConclusionsThus, the assay can correctly differentiate between MTBC and NTM isolates in clinical specimens and would be a useful tool for the rapid differentiation of tuberculosis and NTM disease, despite its limited sensitivity for the diagnosis of NTM disease.


2012 ◽  
Vol 45 (4) ◽  
pp. 250-255 ◽  
Author(s):  
Davood Darban-Sarokhalil ◽  
Abbas Ali Imani Fooladi ◽  
Parviz Maleknejad ◽  
Zakaria Bameri ◽  
Moloud Aflaki ◽  
...  

2014 ◽  
Vol 34 (3) ◽  
pp. 203-209 ◽  
Author(s):  
Young Jin Kim ◽  
Sun Min Lee ◽  
Byung Kyu Park ◽  
Sung Soo Kim ◽  
Jongyoun Yi ◽  
...  

2004 ◽  
Vol 48 (11) ◽  
pp. 4293-4300 ◽  
Author(s):  
Mercedes Marín ◽  
Darío García de Viedma ◽  
María Jesús Ruíz-Serrano ◽  
Emilio Bouza

ABSTRACT Rapid detection of resistance in Mycobacterium tuberculosis can optimize the efficacy of antituberculous therapy and control the transmission of resistant M. tuberculosis strains. Real-time PCR has minimized the time required to obtain the susceptibility pattern of M. tuberculosis strains, but little effort has been made to adapt this rapid technique to the direct detection of resistance from clinical samples. In this study, we adapted and evaluated a real-time PCR design for direct detection of resistance mutations in clinical respiratory samples. The real-time PCR was evaluated with (i) 11 clinical respiratory samples harboring bacilli resistant to isoniazid (INH) and/or rifampin (RIF), (ii) 10 culture-negative sputa spiked with a set of strains encoding 14 different resistance mutations in 10 independent codons, and (iii) 16 sputa harboring susceptible strains. The results obtained with this real-time PCR design completely agreed with DNA sequencing data. In all sputa harboring resistant M. tuberculosis strains, the mutation encoding resistance was successfully detected. No mutation was detected in any of the susceptible sputa. The test was applied only to smear-positive specimens and succeeded in detecting a bacterial load equivalent to 103 CFU/ml in sputum samples (10 acid-fast bacilli/line). The analytical specificity of this method was proved with a set of 14 different non-M. tuberculosis bacteria. This real-time PCR design is an adequate method for the specific and rapid detection of RIF and INH resistance in smear-positive clinical respiratory samples.


2004 ◽  
Vol 42 (4) ◽  
pp. 1585-1589 ◽  
Author(s):  
M. Ruiz ◽  
M. J. Torres ◽  
A. C. Llanos ◽  
A. Arroyo ◽  
J. C. Palomares ◽  
...  

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