Detection of mutations in the rpoB gene of rifampicin-resistant Mycobacterium tuberculosis strains inhibiting wild type probe hybridization in the MTBDR plus assay by DNA sequencing directly from clinical specimens

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.

Synergetic Effect of Rifampin Loaded Mussel‐Inspired Silver Nanoparticles for Enhanced Antibacterial Activity Against Multidrug‐Resistant Strain of Mycobacterium Tuberculosis

“…[19] Rifampin mainly acts on the DNA-dependent RNA polymerase β subunit (rpoB) of M. tuberculosis, which could inhibit the transcription of mRNA. [20] Mutation of rpoB gene is the main cause of rifampinresistance. [21] The synergism against MDR strain of M. tuberculosis is probably due to differences in the mechanism of actions adopted by Ag-PDA NPs and RF.…”

“…In addition, the release of silver ions from silver nanomaterials affecting membrane, DNA, and proteins are also possible antibacterial mechanisms [19] . Rifampin mainly acts on the DNA‐dependent RNA polymerase β subunit (rpoB) of M. tuberculosis , which could inhibit the transcription of mRNA [20] . Mutation of rpoB gene is the main cause of rifampin‐resistance [21] .…”

Fungal-derived compounds and mycogenic nanoparticles with antimycobacterial activity: a review

“…Resistance to isoniazid (1) by M. tuberculosis commonly results from mutations in the katG, kasA and inhA genes. Rifampicin (2) is known to bind to the RNA polymerase β subunit which results in the inhibition of DNA-dependent RNA synthesis, resistance is commonly caused by mutations in the rpoB gene [7].…”

“…Table 1 Frist-, second-and third-line drugs commonly used for the treatment of TB Table 1 was adapted from Zhang and Yew [6] and modified using other sources [7][8][9][10][11][12][13][14] No Compound Multi-drug resistant (MDR) and extensively-drug resistant (XDR) M. tuberculosis simply refers to strains which no longer respond to first-line drugs. The occurrence of these strains is prevalent and necessitates the use of secondline anti-TB drugs which commonly include bedaquiline (5), pretomanid (6), linezolid (7), streptomycin (8) and amikacin (9), kanamycin (10), capreomycin (11), delamanid (12), clofazimine (13), moxifloxacin (14), levofloxacin (15), ofloxacin (16) and ciprofloxacin (17) [4,5]. Secondline TB drugs have been reported to be more toxic and are administered for nine to 24 months with only about half the number of patients being cured [3].…”

Drug-sensitivity test and analysis of drug-resistant mutations in Mycobacterium tuberculosis isolates from Kashgar, China

“…8 These drugs have a strong antibacterial activity, fewer side effects, and long half-life and are the first choice of treatment against TB. A large number of studies have shown that the main cause of the drug resistance is mutations in drug target genes, that is, RopB in case of RFP resistance, [9][10][11] katG and InhA for INH resistance, 12,13 gyrA for ofloxacin (OFX) resistance, 14,15 RpsL and rrs for streptomycin (SM) resistance, 10,[16][17][18] and EmbB for EMB resistance. 17,18 Although the resistance rate to anti-TB drugs in Xinjiang is lower than the average rate in China, 4 the baseline number of patients is large and conventional drugsensitivity tests take a long time.…”