نتایج جستجو برای: katg mutants
تعداد نتایج: 76510 فیلتر نتایج به سال:
Peroxidatic activation of the anti-tuberculosis pro-drug isoniazid by Mycobacterium tuberculosis catalase-peroxidase (KatG) is regulated by gating residues of a heme access channel. The steric restriction at the bottleneck of this channel is alleviated by replacement of residue Asp137 with Ser, according to crystallographic and kinetic studies.
The aim of this study was to evaluate the GenoFlow DR-MTB array test (DiagCor Bioscience, Hong Kong) on 70 cultured isolates and 50 sputum specimens. The GenoFlow array test showed good sensitivity and specificity compared to the phenotypic Bactec 460TB. This array accurately detected mutations inrpoB,katG, andinhAassociated with resistance to rifampin and isoniazid.
PCR amplification of a species-specific 2-kb KpnI fragment of variable size located 10 kb upstream of the katG gene was used to subdivide 130 clinical isolates of Mycobacterium tuberculosis. Seven subtypes were identified, and their frequencies were distributed normally with respect to the size of the amplified product.
We report the genome sequence of Mycobacterium tuberculosis INS-MDR from Peru, a multidrug-resistant tuberculosis (MDR-TB) and Latin American-Mediterranean (LAM) lineage strain. Our analysis showed mutations related to drug resistance in the rpoB (D516V), katG (S315T), kasA (G269S), and pncA (Q10R) genes. Our evidence suggests that INS-MDR may be a clonal expansion related to the African strain...
Quinolones are a large and widely consumed class of synthetic drugs. Expanded-spectrum quinolones, like ciprofloxacin are highly effective against Gram-negative bacteria, especially Escherichia coli. In E. coli the major target for quinolones is DNA gyrase. This enzyme is composed of two subunits, GyrA and GyrB encoding by gyrA and gyrB, respectively. Mutations in either of these genes cause qu...
Appearance of bacteria resistant to antibacterial agents puts physicians in trouble and threatens the health of the world. The rapid development of bacterial resistance in Escherichia coli to ciprofloxacin makes difficult the treatment of infectious diseases. So, detection of the locations of possible mutations in gyrase A gene ( gyrA ) in these mutants is very important to determine the mech...
The exponential phase of aerobic growth is associated with risk of endogenous oxidative stress in which cells need to cope with an approximately 10-fold increase in the rate of H2O2 generation. We addressed this issue by studying the regulation of the intracellular concentration of H2O2 in aerobically growing Escherichia coli. Intracellular H2O2 was kept at an almost constant steady-state value...
The molecular basis for isoniazid resistance in Mycobacterium tuberculosis is complex. Putative isoniazid resistance mutations have been identified in katG, ahpC, inhA, kasA, and ndh. However, small sample sizes and related potential biases in sample selection have precluded the development of statistically valid and significant population genetic analyses of clinical isoniazid resistance. We p...
BACKGROUND Molecular methods that target drug resistance mutations are suitable approaches for rapid drug susceptibility testing to detect multidrug-resistant tuberculosis (MDR-TB). The aim of the study was to determine MDR-TB cases and to analyze the frequency of gene mutations associated with rifampicin (RIF) and/or isoniazid (INH) resistance of Mycobacterium tuberculosis among smear-positive...
BACKGROUND Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure and interaction modelling are used to understand the functional effects of putative mutations and provide insight into the molecular mechanisms leading to resist...
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