scholarly journals The Mycobacterium tuberculosis CRISPR-Associated Cas1 Involves Persistence and Tolerance to Anti-Tubercular Drugs

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Jiawei Wei ◽  
Nan Lu ◽  
Zhiying Li ◽  
Xuanyan Wu ◽  
Tao Jiang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Drug Resistant ◽  
Tuberculosis Complex ◽  
Antitubercular Drugs ◽  
Resistance Evolution ◽  
Associated Proteins ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Rapid Emergence

Tuberculosis remains one of the leading causes of death worldwide. Even if new antitubercular drugs are currently being developed, the rapid emergence and spread of drug-resistant strain remain a severe challenge. The CRISPR associated proteins 1 (Cas1), a most conserved endonuclease which is responsible for spacer integration into CRISPR arrays, was found deleted in many specific drug-resistant strains. The function of Cas1 is still unknown in Mycobacterium type III-A CRISPR family. In this study, the Cas1 (Rv2817c) defect was found in 57.14% of clinical isolates. To investigate the function of Cas1 in new spacer acquisition, we challenged Bacillus Calmette–Guérin (BCG) with a mycobacteriophage D29. Newly acquired spacer sequence matches D29 genome was not found by spacer deep-sequencing. We further expressed Cas1 in recombinant Mycobacterium smegmatis. We found that Cas1 increased the sensitivity to multiple anti-tuberculosis drugs by reducing the persistence during drug treatment. We also showed that Cas1 impaired the repair of DNA damage and changed the stress response of Mycobacterium smegmatis. This study provides a further understanding of Cas1 in Mycobacterium tuberculosis complex (MTBC) drug-resistance evolution and a new sight for the tuberculosis treatment.

Evaluation of efflux pump gene expression among drug susceptible and drug resistant strains of Mycobacterium tuberculosis from Iran

2015 ◽  
Vol 36 ◽  
pp. 23-26 ◽  
Author(s):  
Jalil Kardan Yamchi ◽  
Mehri Haeili ◽  
Seifu Gizaw Feyisa ◽  
Hossein Kazemian ◽  
Abdolrazagh Hashemi Shahraki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mycobacterium Tuberculosis ◽  
Efflux Pump ◽  
Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

Mycobacterium tuberculosis topoisomerases and EthR as the targets for new anti-TB drugs development

2019 ◽  
Vol 11 (16) ◽  
pp. 2193-2203
Author(s):  
Rafal Sawicki ◽  
Grazyna Ginalska
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Short Review ◽  
Drug Resistant ◽  
Dna Topoisomerases ◽  
Antituberculosis Drugs ◽  
Drug Candidates ◽  
Computational Sciences ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
New Strategies

The significant increase in the detection of drug-resistant strains of Mycobacterium tuberculosis caused an urgent need for the discovery new antituberculosis drugs. Development of bioinformatics and computational sciences enabled the progress of new strategies leading to design, discovery and identification of a series of interesting drug candidates. In this short review, we would like to present recently discovered compounds targeting important mycobacterial proteins: DNA topoisomerases and the transcriptional repressor of EthA monooxygenase – EthR.

scholarly journals In Vitro Activity and MIC of Sitafloxacin against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis Isolated in Thailand

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Manoon Leechawengwongs ◽  
Therdsak Prammananan ◽  
Sarinya Jaitrong ◽  
Pamaree Billamas ◽  
Nampueng Makhao ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Critical Concentration ◽  
Multidrug Resistant ◽  
Quinolone Resistance ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

ABSTRACT New fluoroquinolones (FQs) have been shown to be more active against drug-resistant Mycobacterium tuberculosis strains than early FQs, such as ofloxacin. Sitafloxacin (STFX) is a new fluoroquinolone with in vitro activity against a broad range of bacteria, including M. tuberculosis. This study aimed to determine the in vitro activity of STFX against all groups of drug-resistant strains, including multidrug-resistant M. tuberculosis (MDR M. tuberculosis), MDR M. tuberculosis with quinolone resistance (pre-XDR), and extensively drug-resistant (XDR) strains. A total of 374 drug-resistant M. tuberculosis strains were tested for drug susceptibility by the conventional proportion method, and 95 strains were randomly submitted for MIC determination using the microplate alamarBlue assay (MABA). The results revealed that all the drug-resistant strains were susceptible to STFX at a critical concentration of 2 μg/ml. Determination of the MIC90s of the strains showed different MIC levels; MDR M. tuberculosis strains had a MIC90 of 0.0625 μg/ml, whereas pre-XDR and XDR M. tuberculosis strains had identical MIC90s of 0.5 μg/ml. Common mutations within the quinolone resistance-determining region (QRDR) of gyrA and/or gyrB did not confer resistance to STFX, except that double mutations of GyrA at Ala90Val and Asp94Ala were found in strains with a MIC of 1.0 μg/ml. The results indicated that STFX had potent in vitro activity against all the groups of drug-resistant M. tuberculosis strains and should be considered a new repurposed drug for treatment of multidrug-resistant and extensively drug-resistant TB.

scholarly journals Impact of Genomics on Clarifying the Evolutionary Relationships amongst Mycobacteria: Identification of Molecular Signatures Specific for the Tuberculosis-Complex of Bacteria with Potential Applications for Novel Diagnostics and Therapeutics

2018 ◽  
Vol 7 (4) ◽  
pp. 31 ◽  
Author(s):  
Radhey S. Gupta
Keyword(s):  
Comparative Genomic ◽  
Drug Resistant ◽  
Cellular Functions ◽  
Tuberculosis Complex ◽  
Genomic Analyses ◽  
Potential Applications ◽  
Resistant Strains ◽  
Novel Interactions ◽  
Drug Resistant Strains ◽  
High Degree

An alarming increase in tuberculosis (TB) caused by drug-resistant strains of Mycobacterium tuberculosis has created an urgent need for new antituberculosis drugs acting via novel mechanisms. Phylogenomic and comparative genomic analyses reviewed here reveal that the TB causing bacteria comprise a small group of organisms differing from all other mycobacteria in numerous regards. Comprehensive analyses of protein sequences from mycobacterial genomes have identified 63 conserved signature inserts and deletions (indels) (CSIs) in important proteins that are distinctive characteristics of the TB-complex of bacteria. The identified CSIs provide potential means for development of novel diagnostics as well as therapeutics for the TB-complex of bacteria based on four key observations: (i) The CSIs exhibit a high degree of exclusivity towards the TB-complex of bacteria; (ii) Earlier work on CSIs provide evidence that they play important/essential functions in the organisms for which they exhibit specificity; (iii) CSIs are located in surface-exposed loops of the proteins implicated in mediating novel interactions; (iv) Homologs of the CSIs containing proteins, or the CSIs in such homologs, are generally not found in humans. Based on these characteristics, it is hypothesized that the high-throughput virtual screening for compounds binding specifically to the CSIs (or CSI containing regions) and thereby inhibiting the cellular functions of the CSIs could lead to the discovery of a novel class of drugs specifically targeting the TB-complex of organisms.

scholarly journals GENETIC DIVERSITY OF DRUG RESISTANT STRAINS OF MYCOBACTERIUM TUBERCULOSIS IN OMSK REGION

2017 ◽  
Vol 95 (7) ◽  
pp. 33-39
Author(s):  
O. A. Pasechnik ◽  
◽  
A. M. Dymova ◽  
V. L. Stasenko ◽  
M. P. Tatarintseva ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mycobacterium Tuberculosis ◽  
Drug Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

scholarly journals Snapshot of Mycobacterium tuberculosis Phylogenetics from an Indian State of Arunachal Pradesh Bordering China

2021 ◽  
Author(s):  
Rashmi S Mudliar ◽  
Umay Kulsum ◽  
Syed Beenish Rufai ◽  
Mika Umpo ◽  
Moi Nyori ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Drug Resistant ◽  
Second Line ◽  
Arunachal Pradesh ◽  
Tuberculosis Programme ◽  
Indian State ◽  
Northeastern State ◽  
Resistant Strains ◽  
Drug Resistant Strains

Uncontrolled transmission of Mycobacterium tuberculosis (M. tuberculosis, MTB) drug resistant strains is a challenge to control efforts of global tuberculosis programme. Due to increasing multi-drug resistant (MDR) cases in Arunachal Pradesh, a northeastern state of India, the tracking and tracing of these resistant MTB strains is crucial for infection control and spread of drug resistance. This study aims to correlate the phenotypic DST, genomic DST (gDST) and phylogenetic analysis of MDR-MTB strains in the region. Of total 200 suspected MDR-MTB isolates, 125(62.5%) were identified as MTB. MGIT-960 SIRE DST detected 71/125(56.8%) isolates as MDR/RR-MTB of which 22(30.9%) were detected resistant to second line drugs. Whole genome sequencing of 65 isolates and their gDST found Ser315Thr mutation in katG (35/45;77.8%) and Ser531Leu mutation in rpoB (21/41;51.2%) associated with drug resistance. SNP barcoding categorized the dataset with Lineage2 (41;63.1%) being predominant followed by Lineage3 (10;15.4%), Lineage1 (8;12.3%) and Lineage4 (6;9.2%) respectively. Phylogenetic assignment by cgMLST gave insights of two Beijing sub-lineages viz; 2.2.1 (SNP difference < 19) and 2.2.1.2 (SNP difference < 9) associated with recent ongoing transmission in Arunachal Pradesh. This study provides first insight in identifying the ongoing transmission of two virulent Beijing sub-lineages associated with TB drug resistance.

Sign in / Sign up

Export Citation Format

Share Document