Project description:In this study we have used the rifampicin selection as a tool to genetically improve the erythromycin producer Saccharopolyspora erythraea. Two rifampicin-resistant (rif) mutants, rif1 and rif6, have been characterized in more detail. With respect to the parental strain NRRL2338, rif1 (harboring the missense S444F) exhibited higher respiratory performance and final erythromycin yields; in contrast, rif6 (harboring the missense Q426R) was slow-growing, developmental-defective and severely impaired in erythromycin production. The results of genome-wide analysis of expression profiles using DNA micro-arrays demonstrated that these mutations deeply changed the transcriptional profile of S. erythraea with marked regional distribution. Keywords: mutants versus wild type comparison in a time course experiment Total of 12 Samples
Project description:In this study we have used the rifampicin selection as a tool to genetically improve the erythromycin producer Saccharopolyspora erythraea. Two rifampicin-resistant (rif) mutants, rif1 and rif6, have been characterized in more detail. With respect to the parental strain NRRL2338, rif1 (harboring the missense S444F) exhibited higher respiratory performance and final erythromycin yields; in contrast, rif6 (harboring the missense Q426R) was slow-growing, developmental-defective and severely impaired in erythromycin production. The results of genome-wide analysis of expression profiles using DNA micro-arrays demonstrated that these mutations deeply changed the transcriptional profile of S. erythraea with marked regional distribution. Keywords: mutants versus wild type comparison in a time course experiment
2009-04-12 | GSE12017 | GEO
Project description:Discordant Xpert® MTB/RIF Ultra rifampicin resistance in Mycobacterium tuberculosis associated with an A451V (Codon 532) rpoB gene mutation.
Project description:Tuberculosis (TB) is still a major life-threatening infectious disease, within which especially the rise of multidrug resistant TB (MDR-TB) is currently worrying. This study focuses on mechanisms of development of rifampicin resistance, since rifampicin seems to play an important role in the development of MDR-TB. To provide further insight in rifampicin resistance, we performed a genome-wide transcriptional profile analysis for Mycobacterium tuberculosis (M. tuberculosis) using microarray technology and qRT-PCR analysis. We exposed a rifampicin-susceptible H37Rv wild type (H37Rv-WT) and a rifampicin-resistant progeny H37Rv strain with a H526Y mutation in the rpoB gene (H37Rv-H526Y) to several concentrations of rifampicin, to define the effect of rifampicin on the transcription profile. Our study showed that there are resistance-dependant differences in response between both M. tuberculosis strains. Gene clusters associated with efflux, transport and virulence were altered in the rifampicin-resistant H37Rv mutant compared to the rifampicin-susceptible H37Rv-WT strain after exposure to rifampicin. We conclude that the small gene cluster Rv0559c-Rv0560c in the H37Rv-H526Y strain was remarkably up-regulated in the microarray analysis and qRT-PCR results and appeared to be dependent on rifampicin concentration and time of exposure. Therefore this study suggests that Rv0559c and Rv0560c play a pivotal role in rifampicin resistance of M. tuberculosis. Further investigation of Rv0559c and Rv0560c is needed to reveal function and mechanism of both genes that were triggered upon rifampicin exposure. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-139]
Project description:To explore the mechanism of drug resistance, most works focused on resistance associated genetic mutations, whereas concerns for resistance related gene expression are relatively low. Here a global expression analysis was performed between a reference strain H37Rv and two clinical extensively drug-resistant (XDR) strains with three anti-TB drug exposures {isoniazid (INH), capreomycin (CAP), rifampicin (RIF)} Strains were grown in Middlebrook 7H9 broth supplemented with ADC, 0.05% Tween 80 and 0.2% glycerol to an OD600 of 0.5-0.6, and then respectively treated with control (water), 10×MIC INH, 1×MIC RIF and CAP for 6hr.
Project description:The experiment was designed to infer the fitness cost of rifampicin-resistance in Mycobacterium tuberculosis through expression analysis. The approach relied on: 1. Tracking the expression changes occurring as a result of the rifampicin-resistance conferring mutation Ser450Leu in RpoB and subsequent gain of compensatory mutation Leu516Pro in RpoC. The hypothesis was that any cost-incurring expressional changes would be reversed in the presence of compensatory mutations. The strains in this set were described before here: PMID 22179134. 2. Comparing the impact of the same rifampicin-resistance mutation (RpoB Ser450Leu) in five different genetic backgrounds. Here the comparison was solely between RpoB Ser450Leu and their cognate drug susceptible wild type ancestor. One of the strain pairs is the same as in point 1. above.
Project description:Using RNA sequencing we show that exposure of M. abscessus to sublethal doses of RIF results in ~25-fold upregulation of Mab_helR; an isogenic deletion mutant of Mab_helR is hypersensitive to RIF and RBT, and over-expression of Mab_helR confers RIF tolerance in M. tuberculosis, implying that Mab_helR constitutes a significant determinant of inducible RIF and RBT resistance.
Project description:To explore the mechanism of drug resistance, most works focused on resistance associated genetic mutations, whereas concerns for resistance related gene expression are relatively low. Here a global expression analysis was performed between a reference strain H37Rv and two clinical extensively drug-resistant (XDR) strains with three anti-TB drug exposures {isoniazid (INH), capreomycin (CAP), rifampicin (RIF)}
Project description:we utilized Exiqon miRCURY™ LNA Array (v18.0, Exiqon, Vedbaek, Denmark) to establish miRNA expression profiles in the endometrial tissues at the time of embryo implantation(day 7 after ovulation) from 8 RIF patients and 10 matched controls. A total of 157 miRNAs exhibited distinct expression patterns in RIF patients as opposed to controls (fold change >2.0 and P-value <0.05).