Project description:MepR is a substrate-responsive repressor of mepR and mepA, which encode itself and a MATE family multidrug efflux pump. Microarray analyses of Staphylococcus aureus SH1000 and its mepR-disrupted derivative revealed changes in expression of many genes in addition to mepR and mepA, notably several involved in virulence Keywords: Staphylococcus aureus, MATE efflux pump, MepR Staphylococcus aureus strains SH1000 wildtype and mepR were grown in duplicate to exponential and post-exponential phase (corresponding to an A550 nm of 0/4 and 2.0 respectively). RNA was harvested, converted to cDNA, labelled with Biotin and used to probe custom-designed Affymetrix antisense S.aureus GeneChips. Eight samples in total were prepared and analyzed.
Project description:MepR is a substrate-responsive repressor of mepR and mepA, which encode itself and a MATE family multidrug efflux pump. Microarray analyses of Staphylococcus aureus SH1000 and its mepR-disrupted derivative revealed changes in expression of many genes in addition to mepR and mepA, notably several involved in virulence Keywords: Staphylococcus aureus, MATE efflux pump, MepR
Project description:The transcription level of a rex-deficient S. aureus mutant in comparison to its parental strain S. aureus SH1000 was analyzed using DNA microarrays.
Project description:The transcription level of a rex-deficient S. aureus mutant in comparison to its parental strain S. aureus SH1000 was analyzed using DNA microarrays. S. aureus N315 microarrays were purchased from Scienion (Scienion AG, Berlin, Germany) and were produced by spotting 2,338 PCR products of the 2,593 ORFs comprising annotated genome of S. aureus N315 [reference identification: NC_002745] on a glass slide. Each ORF is present in duplicate on the microarray (further details can be found at http://www.scienion.com), cDNA was synthesized from total RNA with the LabelStar Array Kit from QIAGEN using the QIAGEN protocol with slight modifications: Random hexamer primer were used (Invitrogen, Karlsruhe, Germany) and Cy3- and Cy5-dCTP were purchased from Perkin-Elmer (Rodgau - Juegesheim, Germany). As recommended by Scienion, 10 µg RNA from either SH1000 or AK1 were used for cDNA synthesis. After hybridisation for 72 h, the microarrays were washed as recommended by the manufacturer. Data analysis. The hybridized microarrays were scanned with a GenePix 4000B microarray scanner (MDS Analytical Technologies GmbH, Ismaning, Germany). A geometric raster was laid over the resulting microarray picture to distinguish the signals from the background. After localization of single spots, intensities and global background were calculated automatically. The hybridization patterns and intensities were quantitatively analyzed using the Imagene 6 software (BioDiscovery, El Segundo, CA). The replicates were averaged, and the spots identified by Imagene 6 (BioDiscovery) as flawed were omitted. The data set was normalized by application of the LOWESS algorithm. In a next step, the intensity values of all arrays for each time point as well as for all time points combined were used for t tests. Genes with a change of <0.5- or â?¥2.0-fold were characterized as having significantly differing amounts of transcripts based on t tests with a P value cut-off of at least 0.05. Gene functions were assigned to the respective accession numbers and annotations as compiled on DOGAN, a web page for S. aureus N315 (http://www.bio.nite.go.jp/dogan/MicroTop?GENOME_ID=n315G1). The parental strain SH1000 and the Rex deficient mutant AK1 were applied on full-genome microarrays to get a detailed view on the differences in the transcriptional profiles which are caused â?? directly or indirectly â?? by the introduced mutation. More specifically, expression levels were compared at five time points, covering different growth phases. To highlight the general changes in the expression profile between SH1000 and the rex mutant, the microarray data of all five time points were also analyzed in a combined way using standard statistical methods. In further experiments, we focused on those genes, which seemed to flag the general difference between the investigated strains.
Project description:Staphylococcus aureus is one of the most important pathogens in humans and animals, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. Rhein, a natural plant product, has potential antimicrobial activity against Staphylococcus aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with rhein. Results provided insight into mechanisms involved in rhein - Staphylococcus aureus interactions. Keywords: rhein response
Project description:Staphylococcus aureus (S. aureus) is an important human and animal pathogen, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. magnolol has potent antimicrobial activity against S. aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with magnolol. Keywords: gene expression array-based, count
Project description:Manganese (Mn) is an essential micronutrient critical for the pathogenesis of Staphylococcus aureus, a significant cause of human morbidity and mortality. Paradoxically, excess Mn is toxic, therefore maintaining intracellular Mn homeostasis is required for survival. To identify gene candidates that contribute to manganese detoxification, we compared the transcriptional response of S. aureus cells exposed to 1 mM MnCl2 and those that were untreated.
Project description:To determine if significant genomic changes are associated with the development of vancomycin intermediate Staphylococcus aureus, genomic DNA microarrays were performed to compare the initial vancomycin susceptible Staphylococcus aureus (VSSA) and a related vancomycin intermediate Staphylococcus aureus (VISA) isolate from five unique patients (five isolate pairs). Keywords: comparative genomic hybridization
Project description:Staphylococcus aureus (S. aureus) is an important human and animal pathogen, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. Cryptotanshinone, a natural plant product, has potent antimicrobial activity against S. aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with cryptotanshinone. Keywords: gene expression array-based, count
Project description:Staphylococcus aureus (S. aureus) is an important human and animal pathogen, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. eugenol, a natural plant product, has potent antimicrobial activity against S. aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with eugenol. Keywords: gene expression array-based, count