Rapid Detection of Rifampicin-Resistance Mutations in Multidrug-Resistant Strains of Mycobacterium tuberculosis in Morocco

Emergence of multidrug resistant strains ofMycobacterium tuberculosis(MDR-TB) threatens humanity. This problem was complicated by the crisis in development of new anti-tuberculosis antibiotics. Induced reversion of drug resistance seems promising to overcome the problem. Successful clinical trial of a new anti-tuberculosis nanomolecular complex FS-1 has demonstrated prospectively of this approach in combating MDR-TB. Several clinical MDR-TB cultures were isolated from sputum samples prior and in the process of the clinical trial. Every isolate was tested for susceptibility to antibiotics and then they were sequenced for comparative genomics. It was found that the treatment with FS-1 caused an increase in the number of antibiotic susceptible strains among Mtb isolates that was associated with a general increase of genetic heterogeneity of the isolates. Observed impairing of phthiocerol dimycocerosate biosynthesis by disruptive mutations inppsACDsubunits indicated a possible virulence remission for the sake of persistence. It was hypothesized that the FS-1 treatment eradicated the most drug resistant Mtb variants from the population by aggravating the fitness cost of drug resistance mutations. Analysis of distribution of these mutations in the global Mtb population revealed that many of them were incompatible with each other and dependent on allelic states of many other polymorphic loci. The latter discovery may explain the negative correlation between the genetic heterogeneity of the population and the level of drug tolerance. To the best of our knowledge, this work was the first experimental confirmation of the drug induced antibiotic resistance reversion by the induced synergy mechanism that previously was predicted theoretically.

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Effect of Mutation and Genetic Background on Drug Resistance in Mycobacterium tuberculosis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.06460-11 ◽

2012 ◽

Vol 56 (6) ◽

pp. 3047-3053 ◽

Cited By ~ 63

Author(s):

Lukas Fenner ◽

Matthias Egger ◽

Thomas Bodmer ◽

Ekkehardt Altpeter ◽

Marcel Zwahlen ◽

...

Keyword(s):

Drug Resistance ◽

Mycobacterium Tuberculosis ◽

Hot Spot ◽

Multidrug Resistant ◽

Beijing Genotype ◽

Drug Resistant ◽

Resistance Mutations ◽

Content Type ◽

Drug Resistance Mutations ◽

Resistant Strains

ABSTRACTBacterial factors may contribute to the global emergence and spread of drug-resistant tuberculosis (TB). Only a few studies have reported on the interactions between different bacterial factors. We studied drug-resistantMycobacterium tuberculosisisolates from a nationwide study conducted from 2000 to 2008 in Switzerland. We determined quantitative drug resistance levels of first-line drugs by using Bactec MGIT-960 and drug resistance genotypes by sequencing the hot-spot regions of the relevant genes. We determined recent transmission by molecular methods and collected clinical data. Overall, we analyzed 158 isolates that were resistant to isoniazid, rifampin, or ethambutol, 48 (30.4%) of which were multidrug resistant. Among 154 isoniazid-resistant strains,katGmutations were associated with high-level andinhApromoter mutations with low-level drug resistance. OnlykatG(S315T) (65.6% of all isoniazid-resistant strains) andinhApromoter −15C/T (22.7%) were found in molecular clusters.M. tuberculosislineage 2 (includes Beijing genotype) was associated with any drug resistance (adjusted odds ratio [OR], 3.0; 95% confidence interval [CI], 1.7 to 5.6;P< 0.0001). Lineage 1 was associated withinhApromoter −15C/T mutations (OR, 6.4; 95% CI, 2.0 to 20.7;P= 0.002). We found that the genetic strain background influences the level of isoniazid resistance conveyed by particular mutations (interaction tests of drug resistance mutations across all lineages;P< 0.0001). In conclusion,M. tuberculosisdrug resistance mutations were associated with various levels of drug resistance and transmission, andM. tuberculosislineages were associated with particular drug resistance-conferring mutations and phenotypic drug resistance. Our study also supports a role for epistatic interactions between different drug resistance mutations and strain genetic backgrounds inM. tuberculosisdrug resistance.

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Evolutionary trajectories and transmission dynamics of multidrug-resistant Mycobacterium tuberculosis in Tibet, China

10.1101/2021.02.19.21252065 ◽

2021 ◽

Author(s):

Qi Jiang ◽

Hai-can Liu ◽

Qing-yun Liu ◽

Jody E. Phelan ◽

Li Shi ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Phylogenetic Trees ◽

Multidrug Resistant ◽

Rifampicin Resistance ◽

Whole Genome Sequencing Data ◽

High Burden ◽

Increased Risk ◽

Mdr Tb ◽

Resistant Strains ◽

The Impact

ABSTRACTObjectiveTibet has the highest prevalence of both tuberculosis disease and multidrug-resistant tuberculosis (MDR-TB) in China. The circulated Mycobacterium tuberculosis strains from Tibet were sequenced to investigate the underlying drivers for the high burden of MDR-TB.MethodsUsing whole-genome sequencing data of 576 M. tuberculosis strains isolated from consecutive patients in Tibet, we mapped resistance-conferring mutations onto phylogenetic trees to determine their evolution and spread. The impact of drug resistance on bacterial population growth was assessed with a Bayesian (Skyline Plot) analysis. Multivariable logistic regression was used to identify risk factors for the development of rifampicin resistance.ResultsOf the 576 isolates, 284 (49.3%), 280 (48.6%), and 236 (41.0%) were, respectively, genetically resistant to isoniazid, rifampicin, or both (MDR-TB). Among the isoniazid- and rifampicin-resistant strains, the proportions in phylogenetically-inferred clusters were 77.8% (221/284) and 62.1% (174/280), respectively. Nearly half (47.2%, 134/284) of the isoniazid-resistant strains were in six major clades, which contained between 8 and 58 strains with katG S315T, katG S315N, or fabG1 promoter −15 C>T resistance mutations. These major clades exponentially expanded after emerging with isoniazid resistance and stabilized before evolving into MDR-TB twenty years later. Isoniazid-resistant isolates showed an increased risk of accumulating rifampicin resistance compared to isoniazid-susceptible strains, with an adjusted odds ratio of 3.81 (95% confidence interval 2.47-5.95).ConclusionHistorical expansion of isoniazid-resistant strains and their increased likelihood of acquiring rifampicin resistance both contributed to the high burden of MDR-TB in Tibet, highlighting the need to detect INH-resistant strains promptly and to control their transmission.

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Sequence Analyses of Just Four Genes To Detect Extensively Drug-Resistant Mycobacterium tuberculosis Strains in Multidrug-Resistant Tuberculosis Patients Undergoing Treatment

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00050-09 ◽

2009 ◽

Vol 53 (8) ◽

pp. 3353-3356 ◽

Cited By ~ 68

Author(s):

Silke Feuerriegel ◽

Helen S. Cox ◽

Nana Zarkua ◽

Hamraev A. Karimovich ◽

Kai Braker ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Rapid Detection ◽

Target Genes ◽

Multidrug Resistant ◽

Common Mutation ◽

Second Line ◽

Sequence Analyses ◽

Resistant Tuberculosis ◽

Multidrug Resistant Tuberculosis ◽

Resistant Strains

ABSTRACT The rapid detection of Mycobacterium tuberculosis isolates resistant to second-line drugs is crucial for the institution of appropriate treatment regimens as early as possible. Although molecular methods have successfully been used for the rapid detection of resistance to first-line drugs, there are limited data on mutations that confer resistance to second-line drugs. To address this question, we analyzed Mycobacterium tuberculosis strains resistant to ofloxacin (n = 26) and to capreomycin and/or amikacin (n = 48) from Uzbekistan for variations in target genes (gyrA, gyrB, rrs, and tlyA). Strains susceptible to ofloxacin (n = 49) and capreomycin and/or amikacin (n = 39) were included as controls. Mutations in gyrA or gyrB were found in 96% (25/26 strains) of the ofloxacin-resistant strains, while none of the susceptible strains displayed mutations in those two genes. The most common mutation occurred in gyrA at codon 94 (17/26 strains [65.4%]), followed by mutations at codons 90 and 91. Two strains showed a mutation in gyrB, at codons 485 and 543, respectively; both mutations have not been reported previously. The most frequent mutation in strains resistant to both amikacin and capreomycin was A1401G in rrs (34/40 strains [85.0%]). Three strains had mutations in tlyA, of which two (at codons 18 and 118) were associated with resistance to capreomycin alone. Overall, none of the 10 resistant strains (5 amikacin-resistant and capreomycin-susceptible strains) and none of the 39 susceptible control strains had mutations in the genes investigated. Our results clearly demonstrate the potential of sequence analyses of short regions of relatively few target genes for the rapid detection of resistance to second-line drugs among strains isolated from patients undergoing treatment for multidrug-resistant tuberculosis. The mechanisms that confer amikacin resistance in this setting remain unclear.

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Characterization of rifampicin-resistant Mycobacterium tuberculosis in Khyber Pakhtunkhwa, Pakistan

Scientific Reports ◽

10.1038/s41598-021-93501-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Anwar Sheed Khan ◽

Jody E. Phelan ◽

Muhammad Tahir Khan ◽

Sajid Ali ◽

Muhammad Qasim ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Gene Mutations ◽

Multidrug Resistant ◽

Rifampicin Resistance ◽

Resistance Mutations ◽

Khyber Pakhtunkhwa ◽

Tb Control ◽

Mdr Tb ◽

Compensatory Mutations

AbstractTuberculosis (TB), caused by Mycobacterium tuberculosis, is endemic in Pakistan. Resistance to both firstline rifampicin and isoniazid drugs (multidrug-resistant TB; MDR-TB) is hampering disease control. Rifampicin resistance is attributed to rpoB gene mutations, but rpoA and rpoC loci may also be involved. To characterise underlying rifampicin resistance mutations in the TB endemic province of Khyber Pakhtunkhwa, we sequenced 51 M. tuberculosis isolates collected between 2016 and 2019; predominantly, MDR-TB (n = 44; 86.3%) and lineage 3 (n = 30, 58.8%) strains. We found that known mutations in rpoB (e.g. S405L), katG (e.g. S315T), or inhA promoter loci explain the MDR-TB. There were 24 unique mutations in rpoA, rpoB, and rpoC genes, including four previously unreported. Five instances of within-host resistance diversity were observed, where two were a mixture of MDR-TB strains containing mutations in rpoB, katG, and the inhA promoter region, as well as compensatory mutations in rpoC. Heteroresistance was observed in two isolates with a single lineage. Such complexity may reflect the high transmission nature of the Khyber Pakhtunkhwa setting. Our study reinforces the need to apply sequencing approaches to capture the full-extent of MDR-TB genetic diversity, to understand transmission, and to inform TB control activities in the highly endemic setting of Pakistan.

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