Diagnostic value of nine nucleic acid amplification test systems for Mycobacterium tuberculosis complex

Abstract

Objective: In this study, nine commercial Nucleic Acid Amplification Test Systems (NAATs) were evaluated for diagnostic performance of Mycobacterium tuberculosis complex (MTBC) from smear positive sputum species (SPss) and smear negative sputum specimens (SNss). Methods: Sixty SPss and 55 SNss were examined microscopically by Ehrlich Ziehl Neelsen (EZN) staining method, and also inoculated on Löwenstein Jensen (LJ) medium for culture. The sensitivity and specificity of nine NAATs were calculated according to LJ culture method accepted as gold standard. Results: When LJ culture results were taken as gold standard; the sensitivity rates of method COBAS Amplicor MTB (Method A), GenProbe MTD (Method B), Cobas TaqMan MTB PCR (Method C), iCycler iQ RT PCR (Method D), TaqMan PCR AB 5700 (Method E), TaqMan PCR AB7700 (Method F), LightCycler® 480 RT PCR (Method G), Rotor Gene RT PCR (Method H) and the AdvanSure TB/NTM RT PCR (Method I) for SPss were 98.3 %, 93.3 %, 96.7 %, 100 %, 93.3 %, 100 %, 100 %, 100 % and 100 %, respectively. The sensitivity was 53.84% for the methods A, B, D, E, G and I; 38.46% for the method C and H; 61.5% for the method F for the method I in SNss. There were no statistical significant differences between the nine NAATs (p≥0.05). The specificity was 100% for all nine NAATs in SNss. The positivity rates of methods were 53.8% for methods A, B, D, E, G, I; 38.5% for methods C and H, and 61.5% for method F in SNss. These rates were 100% for D, F, G, H and I; 98.3% for method A; 96.7% for method C; 93,3% for methods B and E in SPss. Statistical analysis showed that there was no statistically significant differences among the nine NAATs (p≥0.05). Conclusion: It is concluded that the nine NAATs might be useful for detecting MTBC from SPss, but not effective for SNss.

The Evaluation of the Speed-Oligo® Mycobacteria Assay for Identification of Mycobacterium spp. from Smear Positive and Negative Sputum Samples

“…Due to the contamination of the tuberculosis bacillus by droplets, patients with negative sputum microscopy may become infected during this period. These uncertainties in the diagnosis and treatment of tuberculosis play an important role in spreading the disease and worsening the disease in the patient [1][2][3][4][5][6][7][8]. The incidence of tuberculosis is increasing all over the world.…”

“…For this purpose, PCR -based automated and semi-automated kit based PCR systems developed specifically for MTBC diagnosis are widely used in routine diagnostic laboratories. The sensitivity and specificity of these methods vary according to the system used [6]. In a various studies, lung-derived specimens were analyzed by FDA approved Cobas Amplicor MTB (CAMPMTB; Roche Diagnostic Systems, Inc., Branchburg, NJ) and Amplified Mycobacterium tuberculosis Direct Test (AMTDII; Gen-Probe, Inc., San Diego, Calif.…”

“…Conventional identification tests at the species level are quite complex and sometimes no definite conclusions can be drawn. PCR based methods are widely used in routine diagnostic laboratories for rapid diagnosis [5][6][7][8]. Speed-oligo® Direct Mycobacterium tuberculosis (SO-DMT) is an oligochromatographic test (Vircell SL, Santa Fe, Granada, Spain) for the specific identification of M. tuberculosis complex (MTC) from Mycobacterium genus in respiratory specimens.…”

“…It is based on polymerase chain reaction targeting 16S rRNA and 16S-23S rRNA regions and double-reverse hybridization on a dipstick using probes bound to colloidal gold and to the membrane. It may represent a fast and easy alternative for differentiating between MTBC and NTM in direct samples at laboratories with standard laboratory equipment (thermocycler and thermoblock) [5][6][7][8]. The aim of this study was to evaluate SO-DMT by using 25 type reference strains of mycobacteria (18 non-tuberculosis mycobacteria, M. tuberculosis H37Rv and M. tuberculosis H37Ra), 60 sputum samples (40 smear positive, 20 smear negative) collected from patient with suspected TB.…”

Evaluation of the performance of an in-house duplex PCR assay targeting the IS6110 and rpoB genes for tuberculosis diagnosis in Cameroon

“…Pulmonary tuberculosis (TB) is a leading cause of death worldwide from a single pathogen [ 1 , 2 ]. Despite the availability of effective treatments, TB remains a major public health concern in many low-income countries [ 3 ].…”