Project description:Compilation fo whole genome gene expression changes in Staphylococcus aureus USA300 LAC cultures grown in the presence of vehicle or the anti-gout drug benzbromarone. The drug was intially screened as effective against the agr quorum sensing system in Staphylococcus aureus AH1677. A microarray study using total RNA harvested from three cultures of Staphylococcus aureus USA300 LAC plus vehicle control and three cultures of Staphylococcus aureus USA300 LAC plus 12 uM benzbromarone.
Project description:Compilation fo whole genome gene expression changes in Staphylococcus aureus USA300 LAC cultures grown in the presence of vehicle or the anti-gout drug benzbromarone. The drug was intially screened as effective against the agr quorum sensing system in Staphylococcus aureus AH1677.
Project description:ArlRS is a two-component regulatory system in Staphylococcus aureus. Here we use RNA-sequencing to compare gene expression in a wild-type USA300 strain and an isogenic arlRS mutant.
Project description:MgrA is a global regulator of gene expression in Staphylococcus aureus. Here we use RNA-sequencing to compare gene expression in a wild-type USA300 strain and an isogenic mgrA mutant.
Project description:S. aureus has the propensity to survive a range of NaCl challenge conditions We used commercially available Affymetrix S. aureus GeneChips (part number 900514) to compare the gene expression properties of wild type cells during growth at no or high (2M) NaCl. S. aureus strain USA300-lac cells were grown to late exponential phase growth in the absence or presence of 2M NaCl, total bacterial RNA was isolated and subjected to GeneChip hybridization and analysis. We sought to determine the regulatory effects of high NaCl.
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) infections result in more than 200,000 hospitalizations and 10,000 deaths in the United States each year and remain an important medical challenge. To better understand the transcriptome of Staphylococcus aureus USA300 NRS384, a community-acquired MRSA strain, we have conducted an RNA-Seq experiment on WT samples.
Project description:CodY is a highly conserved global transcriptional factor that regulates the expression of dozens of genes related to metabolism and virulence in Staphylococcus aureus. The S. aureus CodY regulon has been studied in vitro. However, in vivo CodY DNA-binding activity and the identity of the corresponding target genes remain unknown due to lack of a ChIP-grade monoclonal antibody. Using a novel CodY monoclonal antibody that we developed in established ChIP-exo protocols, we report in vivo target genes of CodY in two S. aureus USA300 clinical strains (TCH1516 and LAC). The total number of CodY-binding sites exceeded 110, but their location varied between the two strains. The majority of the identified binding sites were located within the promoter regions. Based on the sequences of the CodY-binding sites, a model of CodY interaction with DNA is proposed. Furthermore, S. aureus CodY protein is highly conserved across a G+C Gram-positive species, including Bacillus subtilis and Listeria monocytogenes, and thus this study paves the way for exploration of the differential binding of CodY among a range of gram-positive species, including pathogenic ones
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) infections result in more than 200,000 hospitalizations and 10,000 deaths in the United States each year and remain an important medical challenge. A key factor of S. aureus pathogenesis is the production of virulence proteins that are secreted into the extracellular matrix damaging host tissues and forming abscesses that may serve as replicative niches for the bacteria. We recently discovered that host-derived cis-unsaturated fatty acids activate the transcription and translation of EsxA, a protein that plays a central role in abscess formation in clinically relevant MRSA strains. Additionally, we discovered that fatty acid stimulation of EsxA is dependent on fakA, a gene that encodes a protein responsible for the incorporation of exogenous fatty acids into the S. aureus phospholipid membrane. In order to gain a comprehensive understanding of host-fatty-acid-sensing in S. aureus, we performed RNA-Seq analysis on WT Staphylococcus aureus USA300 NRS384, a community-acquired MRSA strain, in the presence and absence of 10μM linoleic acid.
Project description:The success of Staphylococcus aureus as a pathogen results from the production of a wealth of virulence determinants that aid in immune evasion, host cell invasion and dissemination of infection. Given the niche specific roles of these factors in infection, their production is controlled by a complex network of regulatory factors. In a continued effort to understand this network, the present study is aimed at characterizing the role of the transcriptional regulator XdrA and its effects on S. aureus gene expression. Using an unbiased global analysis, we find that XdrA has a broad impact on gene expression, influencing the transcription of several important virulence determinants, and factors involved in gene regulation. When assessing the role of XdrA in virulence, we find that an xdrA mutant has an increased ability to survive in whole human blood, mediated in part by increased survival within neutrophils, and an upregulation in expression of several factors involved in immune evasion, including sbi, fnbpA and efb. Furthermore, the increased survival within neutrophils appears to result from an upregulation in expression of sodM, recA, and sae, all of which assist bacterial cells in combating the effects of oxidative stress. In addition to these changes, we find that the xdrA mutant has a decreased abundance of cytolytic toxins, likely resulting from changes in agr and sae activity. We suggest that the broad impact of XdrA on the expression of genes involved in immune evasion, DNA damage, and oxidative stress tolerance, collectively result in a survival advantage allowing for the increased ability to causes disease in vivo, when xdrA is disrupted. In sum, our findings shed new light on the role of XdrA and its seemingly novel influence on S. aureus survival during infection. The dataset contained herein was used to elucidate the whole shotgun secreted proteome (secretome) obtained from 5 hour (mid exponential phase) and 15 hour (stationary phase) planktonic cultures of Staphylococcus aureus USA300 LAC strain, and a derivative of this strain deficient in the gene encoding XdrA.