Comparison of the Genedia MTB Detection Kit and the Cobas TaqMan MTB Assay for Detection of Mycobacterium tuberculosis in Respiratory Specimens

Abstract

bThe performance of the Genedia MTB detection kit was compared with that of the Cobas TaqMan MTB test using respiratory specimens. The Genedia and Cobas assays showed comparable sensitivities (81.8% and 78.8%, respectively) and specificities (99.8% and 99.5%, respectively), while the Genedia assay produced fewer invalid results and required less turnaround time and labor.T uberculosis is a worldwide public health concern. According to the 2013 World Health Organization Global Tuberculosis Report, the country of South Korea has an intermediate level of tuberculosis burden, with an incidence rate of 108 per 100,000 inhabitants (1). Rapid diagnoses and drug treatments that prevent person-to-person transmission remain the top priorities in tuberculosis control (2, 3). Therefore, direct detection of Mycobacterium tuberculosis complex DNA using nucleic acid amplification tests has become an important aspect of rapid diagnosis (4).The Genedia MTB detection kit (Genedia assay; Green Cross Medical Science Corp., Chungbuk, Republic of Korea) was recently developed for rapid molecular detection of the M. tuberculosis complex. The Genedia assay is a real-time PCR method targeting IS6110 with TaqMan hydrolysis probes and has been approved by the Korean Ministry of Food and Drug Safety. We compared the performance of this kit to that of the Cobas TaqMan MTB test (Cobas assay; Roche Diagnostics, Basel, Switzerland). The Cobas assay targets the 16S rRNA region and is one of the most widely utilized real-time PCR assays for M. tuberculosis complex detection outside the United States.This study was conducted at a tertiary-care hospital in Seoul, Republic of Korea, and was approved by the Institutional Review Board of the Samsung Medical Center. In total, 629 consecutive respiratory specimens were prospectively collected from patients with suspected pulmonary tuberculosis between November 2013 and August 2014. All specimens were examined by direct microscopy, mycobacterial cultures, and Cobas and Genedia assays, simultaneously.The respiratory specimens were processed with NALC-NaOH (2% N-acetyl-L-cysteine-sodium hydroxide), followed by centrifugation at 3,000 ϫ g for 20 min. An acid-fast bacillus (AFB) smear procedure was performed with an auramine-rhodamine fluorescent stain, followed by confirmation with Ziehl-Neelsen staining. Staining results were graded according to the American Thoracic Society/Centers for Disease Control and Prevention guidelines (5). Specimens were defined as smear positive when the AFB smear grades were between 1 and 4. All specimens were cultured on both solid and liquid media for 6 weeks. Decontaminated samples were inoculated into a mycobacterial growth indicator tube (MGIT 960 system; Becton Dickinson, Sparks, MD) and on 3% Ogawa agar (Shinyang, Seoul, Republic of Korea). Positive cultures were confirmed both by the presence of cord formation and by MPT64 antigen testing (SD Bioline TB Ag MPT64 Rapid test; Standard Diagnostics Inc., Yongin-si, South Korea), a rapid immunochromatographic assay. When ei...

Sensitivity and specificity of Cobas TaqMan MTB real-time polymerase chain reaction for culture-proven Mycobacterium tuberculosis: meta-analysis of 26999 specimens from 17 Studies

“…1 ). Notably, two candidate articles were excluded due to overlapping data 24 25 . The finally eligible 17 articles included 16 English-language articles and one Korean-language article ( Table 1 ).…”

Diagnosis and Treatment of Nontuberculous Mycobacterial Lung Disease

“…Thus, NAA tests can be used as an additional test for patients with AFB smear-positive sputum for the rapid detection of M. tuberculosis and differentiation from NTM. In addition, some commercial tests are currently available that amplify different target genes to detect M. tuberculosis and several NTM species ( 61 62 ).…”

Combination of commercially available molecular assays and culture based methods in diagnosis of tuberculosis and drug resistant tuberculosis

“…The percentage is slightly higher than previously reported (1.3–4.9%). 9 , 10 , 12 , 15 , 16 The relatively high percentage (2.5%) of PCR false positive results constitutes another controversial fact. There are two different etiologies for such an observation.…”