Evaluation of the Diagnostic Performance of Xpert MTB/RIF Test for the Detection of Mycobacterium tuberculosis and Rifampin Resistance in Clinical Samples

2016 ◽  
Vol 50 (2) ◽  
pp. 196-204 ◽  
Author(s):  
Nafia Canan GÜRSOY ◽  
Yusuf YAKUPOĞULLARI ◽  
Mehmet Sait TEKEREKOĞLU ◽  
Barış OTLU
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Diagnostic Performance ◽  
Clinical Samples ◽  
Rifampin Resistance

scholarly journals Detection of Rifampin Resistance in Mycobacterium tuberculosis by Double Gradient-Denaturing Gradient Gel Electrophoresis

1999 ◽  
Vol 43 (10) ◽  
pp. 2550-2554 ◽  
Author(s):  
Paolo Scarpellini ◽  
Sergio Braglia ◽  
Paola Carrera ◽  
Maura Cedri ◽  
Paola Cichero ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Gel Electrophoresis ◽  
Rapid Detection ◽  
Susceptibility Testing ◽  
Denaturing Gradient Gel Electrophoresis ◽  
The Other ◽  
Clinical Samples ◽  
Pcr Products ◽  
Gradient Gel Electrophoresis ◽  
Rifampin Resistance

ABSTRACT We applied double gradient-denaturing gradient gel electrophoresis (DG-DGGE) for the rapid detection of rifampin (RMP) resistance fromrpoB PCR products of Mycobacterium tuberculosisisolates and clinical samples. The results of this method were fully concordant with those of DNA sequencing and susceptibility testing analyses. DG-DGGE is a valid alternative to the other methods of detecting mutations for predicting RMP resistance.

DETECTING MYCOBACTERIUM TUBERCULOSIS RAPIDLY AND MYCOBACTERIUM TUBERCULOSIS STRAINS WITHOUT IS6110 SEQUENCE BY PCR ASSAY

2012 ◽  
pp. 15-19
Author(s):  
Thi Chau Anh Nguyen ◽  
Hoang Bach Nguyen ◽  
Hai Duong Huynh ◽  
Nu Xuan Thanh Le ◽  
Xuan Cuong Le ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
16S Rdna ◽  
False Negative ◽  
Clinical Samples ◽  
Tuberculosis Complex ◽  
Pcr Assay ◽  
Complex Objects ◽  
Method Performance ◽  
Gene Coding ◽  
16S Rdna Pcr

Background: The Nested IS6110 PCR is used for detecting tuberculosis, however IS6110 sequence is not present in the genome of all strains of M.tuberculosis, the result may be false negative. The gene coding 16S ribosome always contains a short sequence specific to M. tuberculosis complex. Objects: Performance of the 16S Real-time PCR to detect M. tuberculosis and combining to the nested IS6110 PCR to determine the rate of Mtb strains without IS6110 from clinical samples. Materials and method: Performance of 16S rDNA PCR by commercial kit of Viet A Inc. for all 480 samples, the samples which were positive with the 16S rDNA PCR were retested in IS6110 PCR assay by in-house kit. Results: The Realtime 16S rDNA PCR detected 258 cases (53.8%) of tuberculosis. There were 3 (1.2 %) M. tuberculosis strains which do not harbor IS6110 sequence in genome. Conclusion: The IS6110 nested PCR can be applied more widely than the 16S rDNA realtime PCR. In case of using IS6110 PCR assay, results may show a low proportion of false negative. Combining 16S rDNA PCR with the IS6110 based PCR allowed detection of deletion of IS6110 sequence in M. tuberculosis isolates.

scholarly journals Mutations in fbiD (Rv2983) as a Novel Determinant of Resistance to Pretomanid and Delamanid in Mycobacterium tuberculosis

2020 ◽  
Vol 65 (1) ◽  
pp. e01948-20
Author(s):  
Dalin Rifat ◽  
Si-Yang Li ◽  
Thomas Ioerger ◽  
Keshav Shah ◽  
Jean-Philippe Lanoix ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clinical Evidence ◽  
Clinical Samples ◽  
Loss Of Function ◽  
Wild Type ◽  
Content Type ◽  
Solid Media ◽  
High Level ◽  
Level Resistance

ABSTRACTThe nitroimidazole prodrugs delamanid and pretomanid comprise one of only two new antimicrobial classes approved to treat tuberculosis (TB) in 50 years. Prior in vitro studies suggest a relatively low barrier to nitroimidazole resistance in Mycobacterium tuberculosis, but clinical evidence is limited to date. We selected pretomanid-resistant M. tuberculosis mutants in two mouse models of TB using a range of pretomanid doses. The frequency of spontaneous resistance was approximately 10−5 CFU. Whole-genome sequencing of 161 resistant isolates from 47 mice revealed 99 unique mutations, of which 91% occurred in 1 of 5 genes previously associated with nitroimidazole activation and resistance, namely, fbiC (56%), fbiA (15%), ddn (12%), fgd (4%), and fbiB (4%). Nearly all mutations were unique to a single mouse and not previously identified. The remaining 9% of resistant mutants harbored mutations in Rv2983 (fbiD), a gene not previously associated with nitroimidazole resistance but recently shown to be a guanylyltransferase necessary for cofactor F420 synthesis. Most mutants exhibited high-level resistance to pretomanid and delamanid, although Rv2983 and fbiB mutants exhibited high-level pretomanid resistance but relatively small changes in delamanid susceptibility. Complementing an Rv2983 mutant with wild-type Rv2983 restored susceptibility to pretomanid and delamanid. By quantifying intracellular F420 and its precursor Fo in overexpressing and loss-of-function mutants, we provide further evidence that Rv2983 is necessary for F420 biosynthesis. Finally, Rv2983 mutants and other F420H2-deficient mutants displayed hypersusceptibility to some antibiotics and to concentrations of malachite green found in solid media used to isolate and propagate mycobacteria from clinical samples.

scholarly journals Discordance between Xpert MTB/RIF Assay and Bactec MGIT 960 Culture System for Detection of Rifampin-Resistant Mycobacterium tuberculosis Isolates in a Country with a Low Tuberculosis (TB) Incidence

2015 ◽  
Vol 53 (4) ◽  
pp. 1351-1354 ◽  
Author(s):  
Eiman Mokaddas ◽  
Suhail Ahmad ◽  
Hanaa S. Eldeen ◽  
Noura Al-Mutairi
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Culture System ◽  
Content Type ◽  
Rifampin Resistance ◽  
Xpert Assay

Among 452 samples that were positive by the Xpert MTB/RIF (Xpert) assay and MGIT 960 system (MGIT), 440 and 10Mycobacterium tuberculosissamples were detected as rifampin susceptible and rifampin resistant, respectively. Two isolates that were rifampin susceptible by the MGIT system were rifampin resistant by the Xpert assay.rpoBsequencing identified a silent (CTG521TTG) mutation in one isolate and a missense (GAC516TAC) mutation in another. The detection of rifampin resistance is imperfect with both the Xpert assay and MGIT system. Any discordant rifampin resistance results should be confirmed by sequencing of therpoBgene.

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