Comparison of Xpert MTB/RIF with Line Probe Assay for Detection of Rifampin-Monoresistant Mycobacterium tuberculosis
Open Access
- 1 June 2014
- journal article
- research article
- Published by American Society for Microbiology in Journal of Clinical Microbiology
- Vol. 52 (6), 1846-1852
- https://doi.org/10.1128/jcm.03005-13
Abstract
The MTBDR plus line probe assay (LPA) and Xpert MTB/RIF have been endorsed by the World Health Organization for the rapid diagnosis of drug-resistant tuberculosis. However, there is no clarity regarding the superiority of one over the other. In a double-blinded prospective study, we evaluated the efficacy of the Xpert MTB/RIF on samples that were first tested by LPA under the revised national tuberculosis control program of India. A total of 405 sputum samples from suspected drug-resistant tuberculosis patients were included. Of these, 285 smear-positive samples were subjected to LPA. Seventy-two (25.8%) samples showed multidrug resistance, 62 (22.2%) showed rifampin monoresistance, 29 (10.3%) showed isoniazid monoresistance, and 116 (41.5%) were pan-susceptible. Six (2.1%) of the samples gave invalid results. Of the 62 rifampin-monoresistant samples by LPA, 38 (61.4%) showed rifampin resistance, while 21 (33.8%) were found susceptible to rifampin by Xpert MTB/RIF using cartridge version G4. Three (4.8%) samples gave an error. Of the 116 pan-susceptible samples, only 83 were available for Xpert MTB/RIF testing; 4 (5.1%) were rifampin resistant, 74 (94.8%) were susceptible, and 5 (6.0%) showed an error. The 25 discrepant samples were further subjected to MGIT960 drug susceptibility testing. The MGIT960 results showed 100% agreement with LPA results but only 64.4% agreement with Xpert MTB/RIF results. Sequencing analysis of discrepant samples showed 91.3% concordance with LPA but only 8.7% concordance with the Xpert MTB/RIF assay. These findings indicate that by using Xpert MTB/RIF testing we might be underestimating the burden of drug-resistant tuberculosis and indicate that country-specific probes need to be designed to increase the sensitivity of the Xpert MTB/RIF.Keywords
This publication has 31 references indexed in Scilit:
- Advances in tuberculosis diagnostics: the Xpert MTB/RIF assay and future prospects for a point-of-care testThe Lancet Infectious Diseases, 2013
- The Diagnostic Performance of the GenoType MTBDR plus Version 2 Line Probe Assay Is Equivalent to That of the Xpert MTB/RIF AssayJournal of Clinical Microbiology, 2012
- Feasibility, diagnostic accuracy, and effectiveness of decentralised use of the Xpert MTB/RIF test for diagnosis of tuberculosis and multidrug resistance: a multicentre implementation studyThe Lancet, 2011
- Molecular Detection of Mutations Associated with First- and Second-Line Drug Resistance Compared with Conventional Drug Susceptibility Testing of Mycobacterium tuberculosisAntimicrobial Agents and Chemotherapy, 2011
- Evaluation of the Cepheid Xpert MTB/RIF Assay for Direct Detection of Mycobacterium tuberculosis Complex in Respiratory SpecimensJournal of Clinical Microbiology, 2011
- Rapid Molecular Detection of Extrapulmonary Tuberculosis by the Automated GeneXpert MTB/RIF SystemJournal of Clinical Microbiology, 2011
- Rapid Molecular Detection of Tuberculosis and Rifampin ResistanceThe New England Journal of Medicine, 2010
- Origins and Evolution of Antibiotic ResistanceMicrobiology and Molecular Biology Reviews, 2010
- Performance of the Genotype MTBDR Line Probe Assay for Detection of Resistance to Rifampin and Isoniazid in Strains of Mycobacterium tuberculosis with Low- and High-Level ResistanceJournal of Clinical Microbiology, 2006
- Use of Genotype MTBDR Assay for Molecular Detection of Rifampin and Isoniazid Resistance in Mycobacterium tuberculosis Clinical Strains Isolated in ItalyJournal of Clinical Microbiology, 2006