rpoB mutation

Background: Mycobacterium tuberculosis (Mtb) rpoB mutations are associated with global metabolic remodeling. However, the net effects of rpoB mutations on Mtb physiology, metabolism and function are not completely understood. Based on previous work, we hypothesized that changes in the expression of cell wall molecules in Mtb mutant RpoB 526D lead to changes in cell wall permeability and to altered resistance to environmental stresses and drugs. Methods: The phenotypes of a fully drug-susceptible clinical strain of Mtb and its paired rifampin-monoresistant, RpoB H526D mutant progeny strain were compared...

For Mycobacterial tuberculosis complex the rapid and accurate diagnosis of drug resistance is crucial to ensure early initiation of appropriate therapy. Recently a new molecular diagnostic test, the FluoroType ® MTBDR aimed at detecting rifampicin and isoniazid resistance has become available. This study aimed to evaluate the FluoroType ® MTBDR in comparison to phenotypic drug susceptibility testing (DST) using M. tuberculosis complex isolates.MTBC isolates underwent phenotypic DST and were tested using the FluoroType ® MTBDR and Genotype MTBDRplus...

Transcription and translation are coupled processes in bacteria. A role of transcription elongation cofactor NusG in coupling has been suggested by in vitro structural studies. NMR revealed association of the NusG carboxy-terminal domain with S10 (NusE), implying a direct role for NusG as a bridge linking RNAP and the lead ribosome. Here we present the first in vitro and in vivo evidence of full-length NusG association with mature 70S ribosomes. Binding did not require accessory factors in vitro. Mutating the NusG:S10 binding interface at NusG F165 or NusE M88 and D97 residues weakened NusG:S10 association in vivo and completely abolished it in vitro, supporting the specificity of this interaction...

The rpoB gene encodes the β subunit of RNA polymerase holoenzyme in Mycobacterium leprae (M. leprae). Missense mutations in the rpoB gene were identified as etiological factors for rifampin resistance in leprosy. In the present study, we identified mutations corresponding to rifampin resistance in relapsed leprosy cases from three hospitals in southern India which treat leprosy patients. DNA was extracted from skin biopsies of 35 relapse/multidrug therapy non-respondent leprosy cases, and PCR was performed to amplify the 276 bp rifampin resistance-determining region of the rpoB gene...

BACKGROUND: The aim of this study was to identify mutations of rpoB, katG, inhA and ahp-genes associated Mycobacterium tuberculosis resistance to rifampicin (RIF) and isoniazid (INH) in Kyrgyz Republic. We studied 633 smear samples from the primary pulmonary tuberculosis (TB) patients. We verified Mycobacterium tuberculosis susceptibility to RIF and INH using culture method of absolute concentrations, and commercially available test named "TB-BIOCHIP" (Biochip-IMB, Moscow, Russian Federation)...

The Ukraine ranks among the top twenty countries with the highest number of multi-drug resistant (MDR), and extensively drug resistant (XDR) Mycobacterium tuberculosis (MTB) cases in the world. However, little is known of the genetic diversity, i.e., resistance signatures in clinical isolates from this region. We analyzed seven of most prevalent MDR/XDR antibiotic resistance conferring genes from clinical isolates ( N = 75 ) collected from geographically diverse Ukrainian oblasts and its southern Crimean peninsula...

SETTING: Macrolides are a key drug class used for the treatment of Mycobacterium abscessus complex disease. OBJECTIVE: To verify the relationship between phenotypic susceptibility and genotypic resistance to clarithromycin (CLM). DESIGN: Subspecies of M. abscessus complex from 145 consecutive patients were identified using hsp65 and rpoB gene sequencing, and tested for CLM susceptibility, classification into the erm(41) sequevars responsible for inducible resistance and the presence of rrl mutations associated with acquired resistance...

BACKGROUND: Drug resistant Tuberculosis (TB) is considered a global public health threat. Whole-genome sequencing (WGS) is a new technology for tuberculosis (TB) diagnostics and is capable of providing rapid drug resistance profiles and genotypes for epidemiologic surveillance. Therefore, we used WGS to determine genotypic drug resistance profiles and genetic diversity of drug resistant Mycobacterium tuberculosis isolates from Mwanza, North-western Tanzania. METHODS: A cross-sectional study was conducted at the Bugando Medical Center (BMC) from September 2014 to June 2015...

Low-level rifampicin resistance associated with specific rpoB mutations (referred as "disputed") in Mycobacterium tuberculosis is easily missed by some phenotypic methods. To understand the mechanism by which some mutations are systematically missed by MGIT phenotypic testing we performed an in silico analysis of their effect on the structural interaction between the RpoB protein and rifampicin. We also characterized 24 representative clinical isolates by determining minimum inhibitory concentrations (MICs) on 7H10 agar, and testing them by an extended MGIT protocol...

BACKGROUND: WHO MDT is the main drug regimen for treating leprosy and has been used for more than three decades. Many cases of relapse of leprosy have been reported, which points towards the emergence of drug resistance with the antileprotic drugs. OBJECTIVES: To find the resistance with the antileprotic drugs by detecting the mutations in drug resistance determining region of the rpoB, folP1 and gyrA genes of Mycobacterium leprae. METHODS: Leprosy patients with bacterial index ≥2 were included in the study...

The absence of base excision repair (BER) proteins involved in processing ROS-promoted genetic insults activates a DNA damage scanning (DisA)-dependent checkpoint event in outgrowing Bacillus subtilis spores. Here, we report that genetic disabling of transcription-coupled repair (TCR) or nucleotide excision repair (NER) pathways severely affected outgrowth of ΔdisA spores, and much more so than the effects of these mutations on log phase growth. This defect delayed the first division of spore's nucleoid suggesting that unrepaired lesions affected transcription and/or replication during outgrowth...

BACKGROUND: Rifampicin (RFP) is one of the principal first-line drugs used in combination chemotherapies against Mycobacterium tuberculosis, and its use has greatly shortened the duration of chemotherapy for the successful treatment of drug-susceptible tuberculosis. Compensatory mutations have been identified in rpoC that restore the fitness of RFP-resistant M. tuberculosis strains with mutations in rpoB. To investigate rpoC mutation patterns, we analyzed 93 clinical M. tuberculosis isolates from patients in South Korea...

A total of 39 coagulase-negative staphylococci and seven Staphylococcus aureus strains were isolated from small mammal feces, i.e., the striped field mouse (Apodemus agrarius) and the yellow-necked mouse (A. flavicollis) in two sampling areas, deciduous forest and karst plains. MALDI-TOF analysis revealed five species of coagulase-negative staphylococci: S. sciuri, S. hominis, S. warneri, S. haemolyticus, and S. xylosus. All strains were susceptible to tetracycline, linezolid, vancomycin, and teicoplanin. Three MRSA strains with the mecA gene were detected...

The temperate bacteriophage lambda (λ) CII protein is a positive regulator of transcription from promoter pE , a component of the lysogenic response. The expression of cII was examined in vectors devoid of phage transcription-modulating elements. Their removal enabled evaluating if the expression of the small RNA OOP, on its own, could suppress CII activities, including complementing for a lysogenic response, cell toxicity and causing rapid cellular loss of ColE1 plasmids. The results confirm that OOP RNA expression from the genetic element pO-oop-to can prevent the ability of plasmid-encoded CII to complement for a lysogenic response, suggesting that it serves as a powerful regulatory pivot in λ development...

Objective: To comprehensively identify compensatory mutations in rpoA, rpoB and rpoC genes of rifampicin-resistant Mycobacterium tuberculosis (RIF-r MTB) and to evaluate the effect of rifampicin-resistant mutation type and lineage background on occurrence of compensatory mutations. Methods: Published MTB whole genome sequencing data were searched and downloaded. RIF-r MTB was identified through known rifampicin-resistant mutations. Based on parallel evolutionary patterns, we identified putative compensatory mutations in the phylogenetic tree and calculated proportions of accumulating compensatory mutations in each rifampicin-resistant mutations' type and lineage background of RIF-r MTB...

OBJECTIVES: Antimicrobial resistance (AMR) is a priority for surveillance in bacterial infections. For leprosy, AMR has not been assessed because Mycobacterium leprae does not grow in vitro. We aim to obtain AMR data using molecular detection of resistance genes and to conduct a prospective open survey of resistance to antileprosy drugs in countries where leprosy is endemic through a WHO surveillance network. METHODS: From 2009 to 2015, multi-bacillary leprosy cases at sentinel sites of 19 countries were studied for resistance to rifampicin, dapsone and ofloxacin by PCR sequencing of the drug-resistance-determining regions of the genes rpoB, folP1 and gyrA...

The effect of Bacillus subtilis exposure to the human spaceflight environment on growth, mutagenic frequency, and spectrum of mutations to rifampicin resistance (RifR ) was investigated. B. subtilis cells were cultivated in Biological Research in Canister-Petri Dish Fixation Units (BRIC-PDFUs) on two separate missions to the International Space Station (ISS), dubbed BRIC-18 and BRIC-21, with matching asynchronous ground controls. No statistically significant difference in either growth or in the frequency of mutation to RifR was found in either experiment...

BACKGROUND: Tuberculosis (TB) is the highest-mortality infectious disease in the world and the main cause of death related to antimicrobial resistance, yet its surveillance is still paper-based. Rifampicin-resistant TB (RR-TB) is an urgent public health crisis. The World Health Organization has, since 2010, endorsed a series of rapid diagnostic tests (RDTs) that enable rapid detection of drug-resistant strains and produce large volumes of data. In parallel, most high-burden countries have adopted connectivity solutions that allow linking of diagnostics, real-time capture, and shared repository of these test results...

BACKGROUND: The emergence of extensively drug-resistant tuberculosis (XDR-TB) has raised public health concern for global TB control. Although multi drug-resistant tuberculosis (MDR- TB) prevalence and associated genetic mutations in Morocco are well documented, scarce information on XDR TB is available. Hence, the evaluation of pre-XDR and XDR prevalence, as well as the mutation status of gyrA, gyrB, rrs, tlyA genes and eis promoter region, associated with resistance to second line drugs, is of great value for better management of M/XDR TB in Morocco...

OBJECTIVE: To assess drug susceptibility and characterize Clostridium difficile ribotypes in isolates from two tertiary-care hospitals in Mexico. METHODS: Isolates were evaluated for genotyping, antimicrobial susceptibility testing and detection of mutations associated with drug resistance. PCR ribotyping was performed using a combination of gel-based and capillary electrophoresis-based approaches. RESULTS: MIC50 and MIC90 were ≥128 mg/L for ciprofloxacin, erythromycin, clindamycin, and rifampicin...