Characterization of rpoB Mutations in Rifampin-Resistant Clinical Isolates of Mycobacterium tuberculosis from Turkey by DNA Sequencing and Line Probe Assay

Abstract Background The potential of genetic testing for rapid and accurate diagnosis of drug-resistant Mycobacterium tuberculosis strains is vital for efficient treatment and reduction in dissemination. MTBDR plus assays rapidly detect mutations related to drug resistance and wild type sequences allied with susceptibility. Although these methods are promising, the examination of molecular level performance is essential for improved assay result interpretation and continued diagnostic development. Therefore this study aimed to determine novel mutations that were inhibiting wild type probe hybridization in the Line probe assay by DNA sequencing. Using data collected from Line Probe assay (GenoType MTBDRplus assay) the contribution of absent wild type probe hybridization to the detection of rifampicin resistance was assessed via comparison to a reference standard method i.e. DNA sequencing. Results Sequence analysis of the rpoB gene of 47 MTB resistant strains from clinical specimens showed that 37 had a single mutation, 9 had double mutations and one had triple mutations in the ropB gene. Conclusions The absence of wild type probe hybridization without mutation probe hybridization was mainly the result of the failure of mutation probe hybridization and the result of the novel or rare mutations. Additional probes are necessary to be included in the Line probe assay to improve the detection of rifampicin-resistant Mycobacterium tuberculosis strains.

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Molecular characterization of multiple-drug-resistant Mycobacterium tuberculosis isolates from northwestern Russia and analysis of rifampin resistance using RNA/RNA mismatch analysis as compared to the line probe assay and sequencing of the rpoB gene

Research in Microbiology ◽

10.1016/s0923-2508(02)01311-6 ◽

2002 ◽

Vol 153 (4) ◽

pp. 213-219 ◽

Cited By ~ 26

Author(s):

Igor Mokrousov ◽

Ingrid Filliol ◽

Eric Legrand ◽

Christophe Sola ◽

Tatiana Otten ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Rpob Gene ◽

Multiple Drug ◽

Drug Resistant ◽

Line Probe Assay ◽

Multiple Drug Resistant ◽

Rifampin Resistance ◽

Probe Assay ◽

Northwestern Russia

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Evaluation of a line probe assay for the rapid detection of gyrA mutations associated with fluoroquinolone resistance in multidrug-resistant Mycobacterium tuberculosis

Journal of Medical Microbiology ◽

10.1099/jmm.0.024729-0 ◽

2011 ◽

Vol 60 (2) ◽

pp. 184-188 ◽

Cited By ~ 12

Author(s):

Hiroki Ando ◽

Satoshi Mitarai ◽

Yuji Kondo ◽

Toshinori Suetake ◽

Seiya Kato ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Global Health ◽

Dna Sequencing ◽

Rapid Detection ◽

Multidrug Resistant ◽

Surveillance Study ◽

Fluoroquinolone Resistance ◽

National Surveillance ◽

Line Probe Assay ◽

Probe Assay

The aim of this study was to establish the importance of detecting fluoroquinolone (FQ) resistance in multidrug resistant (MDR) Mycobacterium tuberculosis, and to show the usefulness of a hybridization-based line probe assay (LiPA) for detecting gyrA mutations. Thirty-three MDR M. tuberculosis isolates were collected from a total of sixty MDR isolates identified in Japan over 6 months during a national surveillance study in 2002. Seventeen MDR isolates were collected by the National Center for Global Health and Medicine in Japan over 6 years from 2003 to 2008. These 50 isolates were examined for FQ susceptibility, and analysed by LiPA and gyrA sequencing. Among them, 22 (44 %) showed FQ resistance. All FQ-resistant isolates had at least one mutation in gyrA. The results of the LiPA were fully consistent with the DNA sequencing results. Given that on the basis of our results almost half of the MDR M. tuberculosis isolates in Japan might have resistance to FQ, it is important to monitor FQ resistance in patients with MDR tuberculosis (TB), as well as with drug-susceptible TB, prior to commencing treatment. For the detection of FQ resistance, LiPA is useful and can rapidly and efficiently assess FQ resistance.

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