Transcriptomic analysis of rsp deficient Staphylococcus aureus
Ontology highlight
ABSTRACT:
ORGANISM(S): Staphylococcus aureus
PROVIDER: GSE199593 | GEO | 2022/03/28
REPOSITORIES: GEO
Similar Datasets
Project description:Staphylococcus aureus is a Gram-positive human pathogen causing a variety of human diseases in both hospital and community settings. This bacterium is so closely associated with prophages that it is rare to find S. aureus isolates without prophages. Two phages are known to be important for staphylococcal virulence: the beta-hemolysin (hlb) converting phage and the Panton-Valentine Leukocidin (PVL) converting phage. The hlb-converting phage is found in more than 90% of clinical isolates of S. aureus. This phage produces exotoxins and immune modulatory molecules, which inhibit human innate immune responses. The PVL-converting phage produces the two-component exotoxin PVL, which can kill human leucocytes. This phage is wide-spread among community-associated methicillin resistant S. aureus (CA-MRSA). It also shows strong association with soft tissue infections and necrotizing pneumonia. Several lines of evidence suggest that staphylococcal prophages increase bacterial virulence not only by providing virulence factors but also by altering bacterial gene expression: 1) Transposon insertion into prophage regulatory genes, but not into the genes of virulence factors, reduced S. aureus killing of Caenorhabditis elegans.; 2) Although the toxins and immune modulatory molecules encoded by the hlb- converting phages do not function in the murine system, deletion of ϕNM3, the hlb-converting phage in S. aureus Newman, reduced staphylococcal virulence in the murine abscess formation model. 3) In a preliminary microarray experiment, prophages in S. aureus Newman altered the expression of more than 300 genes. In this research proposal, using microarray and high-throughput quantitative RT-PCR (qRT-PCR) technologies, we will identify the effects of the two important staphylococcal phages on the gene expression of S. aureus in both in vitro and in vivo conditions. This project is intended to be completed within one year. All the data – microarray, qRT-PCR and all the primer sequences- will be made available to public 6 month after completion. Data from this project will help us to understand the role of prophages in the S. aureus pathogenesis and can lead to development of a strategy to interfere with the pathogenesis process. Following strains were grown in TSA broth: Staphylococcus aureus USA300 (reference) Staphylococcus aureus USA300 with deletion of ϕSa2usa (Query) Staphylococcus aureus USA300 with deletion of ϕSa3usa (Query) Staphylococcus aureus USA300 Prophage-free mutant (Query) Staphylococcus aureus USA300 Prophage-free mutant lysogenized with ϕSa2mw (Query) Staphylococcus aureus USA300 Prophage-free mutant lysogenized with ϕSa3usa (Query) strain: Staphylococcus aureus USA300 Prophage-free mutant lysogenized with both ϕSa2mw and ϕSa3usa (Query) RNA samples were harvested at early log, midlog and stationary phase.Samples were hybridized on aminosilane coated slides with 70-mer oligos.
2011-02-28 | E-GEOD-26623 | biostudies-arrayexpress
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.
2022-04-08 | GSE174558 | GEO
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
2009-07-01 | GSE10033 | GEO
Project description:Staphylococcus aureus Newman and Staphylococcus epidermidis Tu3298, 20 minutes post challenge with sub-inhibitory concentration of sapienic acid vs equivalent concentration of ethanol. Challenge was added at mid logarithmic growth (OD600 0.5). Biological triplicates of samples were sequenced.
2016-07-31 | E-MTAB-4587 | biostudies-arrayexpress
Project description:The opportunistic pathogen, Staphylococcus aureus, encounters a wide variety of fluid shear levels within the human host, which may play a key role in dictating whether this organism adopts a commensal interaction with the host or transitions to cause disease. Using rotating-wall vessel bioreactors to create a physiologically-relevant, low fluid shear environment, S. aureus was evaluated for cellular responses that could impact its colonization and virulence. S. aureus cells grown in a low fluid shear environment initiated a novel attachment-independent biofilm phenotype and were completely encased in extracellular polymeric substances. Compared to controls, low-shear cultured cells displayed slower growth and repressed virulence characteristics, including decreased carotenoid production, increased susceptibility to oxidative stress, and reduced survival in whole blood. Transcriptional whole genome microarray profiling suggested alterations in metabolic pathways. Further genetic expression analysis revealed the down-regulation of the RNA chaperone Hfq, which parallels low fluid shear responses of certain Gram negative organisms. This is the first study to report an Hfq association to fluid shear in a Gram positive organism, suggesting an evolutionarily conserved response to fluid shear among structurally diverse prokaryotes. Collectively, our results suggest S. aureus responds to a low fluid shear environment by initiating a biofilm/colonization phenotype with diminished virulence characteristics, which could lead to insight into key factors influencing the divergence between infection and colonization during initial host pathogen interaction. Genetic expression profiles of Staphylococcus aureus cultured under low fluid shear conditions was compared to control cultures of S. aureus which was cultured in identical hardware in an orientation disrupting the low fluid shear effect. Samples from the same date of culture were compared (control 21:low 21 and control 30: low 30). S. aureus was cultured for 20 hours in either the low fluid shear or control orientated rotating wall vessel (RWV) bioreactor at which point the cells were removed and RNA extracted. At 20 hours, both cultures were in the same stage of growth (stationary phase) and at this point phenotypic differences between control and low fluid shear cultures were noted.
2011-05-31 | E-GEOD-28077 | biostudies-arrayexpress
Project description:Staphylococcus aureus is a major human pathogen and resistant to numerous clinically used antibiotics. The first antibiotic developed for S. aureus infections was the nonribosomal petide secondary metabolite penicillin. We discovered cryptic nonribosomal peptide secondary metabolites, the aureusimines, made by S. aureus itself that are not antibiotics, but function as small molecule regulators of virulence factor expression. Using established rules and codes for nonribosomal peptide assembly we predicted these nonribosomal peptides, and used these predictions to identify them from S. aureus culture broths. Functional studies using global microarray and mouse bacteremia models established that the aureusimines control virulence factor expression and are necessary for productive infections. This is the first report of the aureusimines and has important implications for the treatment of drug resistant S. aureus. Targeting aureusimine synthesis may provide novel anti-infectives.
2010-07-01 | GSE21373 | GEO
Project description:Staphylococcus aureus pneumonia causes significant morbidity and mortality. Alpha-hemolysin (Hla), a pore-forming cytotoxin of S. aureus, has been identified through animal models of pneumonia as a critical virulence factor that induces lung injury. In spite of considerable molecular knowledge of how this cytotoxin injures the host, the precise host response to Hla in the context of infection remains poorly understood. We employed whole-genome expression profiling of infected lung to define the host response to wild-type S. aureus compared with an Hla-deficient isogenic mutant in experimental pneumonia. These data provide a complete expression profile at four and at twenty-four hours post-infection, revealing a unique response to the toxin-expressing strain. Gene ontogeny analysis revealed significant differences in the extracellular matrix and cardiomyopathy pathways, both of which govern cellular interactions in the tissue microenvironment. Evaluation of individual transcript responses to Hla-secreting bacteria was notable for upregulation of host cytokine and chemokine genes, including the p19 subunit of interleukin-23. Consistent with this observation, the cellular immune response to infection was characterized by a prominent TH17 response to wild-type staphylococci. These findings define specific host mRNA responses to Hla-producing S. aureus, coupling the pulmonary TH17 response to the presence of this cytotoxin. Expression profiling to define the host response to a single virulence factor proved to be a valuable tool in identifying pathways for further investigation in S. aureus pneumonia. This approach may be broadly applicable to the study of bacterial toxins, defining host pathways that can be targeted to mitigate toxin-induced disease. Animals were treated with PBS, S. aureus wild-type, or S. aureus Hla-deficient isogenic mutant.
2012-05-20 | E-GEOD-38053 | biostudies-arrayexpress
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
2007-06-15 | GSE8135 | GEO
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.
2010-05-16 | E-GEOD-10033 | biostudies-arrayexpress
Project description:In this study we addressed the question how a mevalonate (MVA)-auxotrophic Staphylococcus aureus ΔmvaS mutant can revert to prototrophy.
2020-05-31 | GSE131722 | GEO