Elucidating the Linezolid response of Staphylococcus aureus USA300 by a holistic study
Ontology highlight
ABSTRACT:
ORGANISM(S): Staphylococcus aureus
SUBMITTER: Florian Bonn
PROVIDER: E-GEOD-65209 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The translation inhibitor Linezolid is an important antibiotic of last resort against multiresistant gram-positive pathogens including MRSA. Linezolid is reported to specifically inhibit extracellular virulence factors, but the molecular cause is unknown. To elucidate the physiological response of S. aureus to Linezolid in general and the possible inhibition of virulence factors specifically we performed a holistic study. We added Linezolid to logarithmically growing S. aureus cells and analyzed the Linezolid stress response with transcriptomics, quantitative proteomics and microscopy experiments. As previously observed in studies on other translation inhibitors S. aureus is adapting its protein biosynthesis machinery to the reduced translation efficiency, for example the synthesis of ribosomal proteins is induced. But we also observed unexpected results like a general decline in the amount of extracellular and membrane proteins. In addition cell shape and size changed after Linezolid stress and cell division was diminished. Finally, the chromosome condensed after LZD stress and lost contact to the membrane.
2016-02-22 | GSE65209 | GEO
Project description:The translation inhibitor Linezolid is an important antibiotic of last resort against multiresistant gram-positive pathogens including MRSA. Linezolid is reported to specifically inhibit extracellular virulence factors, but the molecular cause is unknown. To elucidate the physiological response of S. aureus to Linezolid in general and the possible inhibition of virulence factors specifically we performed a holistic study. We added Linezolid to logarithmically growing S. aureus cells and analysed the Linezolid stress response with transcriptomics, quantitative proteomics and microscopy experiments.
2016-03-18 | PXD001659 | Pride
Project description:The precise mechanism and effects of antibiotics in host gene expression and immunomodulation in MRSA infection is unknown. Using a well characterized Methicillin Resistant Staphylococcus aureus (MRSA) isolate USA300 in a murine model of infection, we determined that linezolid and vancomycin induced differential production of bacterial toxins and host cytokines, differences in host gene expression, and differences in immunomodulators during MRSA bloodstream infection. A total of 35 A/J mice, categorized into seven groups (no infection; no infection with linezolid; no infection with vancomycin; 2 hour post-infection (hpi) S. aureus; 24 hpi S. aureus; 24 hpi S. aureus with linezolid; and 24 hpi S. aureus with vancomycin), were used in this study. Mice were injected with USA300 (6 x 106 CFU/g via i.p. route), then intravenously treated with linezolid (25 mg/kg) or vancomycin (25 mg/kg) at 2 hpi. Control and S. aureus infected mice were euthanized at each time point (2 h or 24h) following injection. Whole blood RNA was used for microarray; three cytokines and two S. aureus toxins [PantonValentine Leukocidin (PVL) and alpha hemolysin] were quantified in mouse serum by ELISA. S. aureus CFUs were significantly reduced in blood and kidney after linezolid or vancomycin treatment in S. aureus-infected mice. In vivo IL-1M-NM-2 in mouse serum was significantly reduced in both linezolid (p=0.001) and vancomycin (p=0.006) treated mice compared to untreated ones. IL-6 was significantly reduced only in linezolid treated (p<0.001) but not in vancomycin treated mice. However, another proinflammatory cytokine, TNF-M-NM-1, did not exhibit altered levels in either linezolid or vancomycin treated mice (p=0.3 and p=0.51 respectively). In vivo level of bacterial toxin, Panton-Valentine leukocidin, in mouse serum was significantly reduced only in linezolid treated mice (p=0.02) but not in vancomycin treated mice. There was no significant effect of either treatment in in vivo level of alpha hemolysin production. Unsupervised hierarchical clustering using the gene expression data from 35 microarrays revealed distinct clustering based on infection status and treatment group. Study of the antibiotic-specific difference in gene expression identified the number of genes uniquely expressed in response to S. aureus infection, infection with linezolid treatment, and infection with vancomycin treatment. Pathway associations study for the differentially expressed genes in each comparison group (Control vs. 24 h S. aureus infection, 24 h S. aureus infection vs. 24 h S. aureus linezolid, and 24 h S. aureus infection vs. 24 h S. aureus vancomycin) in mice using Kyoto Encyclopedia of Genes and Genomes (KEGG) identified toll-like receptor signaling pathway to be common to every comparison groups studied. Glycerolipid metabolism pathway was uniquely associated only with linezolid treatment comparison group. The findings of this study provide the evidence that protein synthesis inhibitor like linezolid does a better job in treating MRSA sepsis compared to cell wall acting antibiotics like vancomycin. To identify differences in host gene expression in a murine sepsis model treated with a) linezolid and b) vancomycin, we used whole blood gene expression (RNA) signatures from A/J inbred mice infected with USA 300 MRSA to evaluate differences in host gene expression among mice treated with linezolid and vancomycin. We used 5 RNA samples from MRSA-infected, linezolid- or vancomycin-treated mice. A total of 7 experimental groups have been employed: 1) Uninfected control group: (negative controls). 2) Uninfected, linezolid-treated group: Uninfected, linezolid-treated mice. 3) Uninfected vancomycin-treated group: Uninfected, vancomycin-treated mice. 4) Infected control group (positive control 2 h) MRSA-infected, untreated mice. 5) Infected control group (positive control 24 h): MRSA-infected, untreated mice. 6) Infected linezolid group: MRSA-infected, linezolid-treated mice. 7) Infected vancomycin group: MRSA-infected, vancomycin-treated mice.
2014-06-05 | E-GEOD-38531 | biostudies-arrayexpress
Project description:The translation inhibitor Linezolid is an important antibiotic of last resort against multiresistant gram-positive pathogens including MRSA. Linezolid is reported to specifically inhibit extracellular virulence factors, but the molecular cause is unknown. To elucidate the physiological response of S. aureus to Linezolid in general and the possible inhibition of virulence factors specifically we performed a holistic study. We added Linezolid to logarithmically growing S. aureus cells and analysed the Linezolid stress response with transcriptomics, quantitative proteomics and microscopy experiments.
2016-03-18 | PXD001622 | Pride
Project description:The precise mechanism and effects of antibiotics in host gene expression and immunomodulation in MRSA infection is unknown. Using a well characterized Methicillin Resistant Staphylococcus aureus (MRSA) isolate USA300 in a murine model of infection, we determined that linezolid and vancomycin induced differential production of bacterial toxins and host cytokines, differences in host gene expression, and differences in immunomodulators during MRSA bloodstream infection. A total of 35 A/J mice, categorized into seven groups (no infection; no infection with linezolid; no infection with vancomycin; 2 hour post-infection (hpi) S. aureus; 24 hpi S. aureus; 24 hpi S. aureus with linezolid; and 24 hpi S. aureus with vancomycin), were used in this study. Mice were injected with USA300 (6 x 106 CFU/g via i.p. route), then intravenously treated with linezolid (25 mg/kg) or vancomycin (25 mg/kg) at 2 hpi. Control and S. aureus infected mice were euthanized at each time point (2 h or 24h) following injection. Whole blood RNA was used for microarray; three cytokines and two S. aureus toxins [PantonValentine Leukocidin (PVL) and alpha hemolysin] were quantified in mouse serum by ELISA. S. aureus CFUs were significantly reduced in blood and kidney after linezolid or vancomycin treatment in S. aureus-infected mice. In vivo IL-1β in mouse serum was significantly reduced in both linezolid (p=0.001) and vancomycin (p=0.006) treated mice compared to untreated ones. IL-6 was significantly reduced only in linezolid treated (p<0.001) but not in vancomycin treated mice. However, another proinflammatory cytokine, TNF-α, did not exhibit altered levels in either linezolid or vancomycin treated mice (p=0.3 and p=0.51 respectively). In vivo level of bacterial toxin, Panton-Valentine leukocidin, in mouse serum was significantly reduced only in linezolid treated mice (p=0.02) but not in vancomycin treated mice. There was no significant effect of either treatment in in vivo level of alpha hemolysin production. Unsupervised hierarchical clustering using the gene expression data from 35 microarrays revealed distinct clustering based on infection status and treatment group. Study of the antibiotic-specific difference in gene expression identified the number of genes uniquely expressed in response to S. aureus infection, infection with linezolid treatment, and infection with vancomycin treatment. Pathway associations study for the differentially expressed genes in each comparison group (Control vs. 24 h S. aureus infection, 24 h S. aureus infection vs. 24 h S. aureus linezolid, and 24 h S. aureus infection vs. 24 h S. aureus vancomycin) in mice using Kyoto Encyclopedia of Genes and Genomes (KEGG) identified toll-like receptor signaling pathway to be common to every comparison groups studied. Glycerolipid metabolism pathway was uniquely associated only with linezolid treatment comparison group. The findings of this study provide the evidence that protein synthesis inhibitor like linezolid does a better job in treating MRSA sepsis compared to cell wall acting antibiotics like vancomycin.
2014-06-05 | GSE38531 | GEO
Project description:Previous evaluation by different molecular and physiological assays of Staphylococcus aureus (S. aureus) responses to heat shock exposure yielded a still fragmentary view of the mechanisms determining bacterial survival or death at supra-physiological temperatures. This study analyzed diverse facets of S. aureus heat-shock adjustment by recording global transcriptomic and metabolic responses of bacterial cultures shifted for 10 min from 37oC to a sub-lethal (43oC) or eventually lethal (48oC) temperature. A relevant metabolic model of the combined action of specific stress response mechanisms with more general, energy-regulating metabolic pathways in heat-shocked S. aureus was designed. While S. aureus cultures shifted to 43oC or left at 37oC showed marginal differences in growth and survival rates, bacterial cultures exposed to 48oC showed a rapid growth arrest followed by a subsequent decline in viable counts. The most substantial heat shock-induced changes at both 43oC and 48oC occurred in transcript levels of HrcA- and CtsR-regulated genes, encoding classical chaperones DnaK and GroESL, and some Hsp100/Clp ATPases components, respectively. Other metabolic pathways up-regulated by S. aureus exposure at 48oC included genes encoding several enzymes coping with oxidative stress, and DNA damage, or/and impaired osmotic balance. Some major components of the pentose phosphate cycle and gluconeogenesis were also up-regulated, which reflected depletion of free glucose by bacterial cultures grown in Mueller-Hinton broth prior to heat shock. In contrast, most purine- and pyrimidine-synthesis pathway components and amino acyl-tRNA synthetases were down-regulated at 48oC, as well as arginine deiminase and major fermentative pathway components, such as alcohol, lactate and formate dehydrogenases. Despite the heat-induced, increased requirements for ATP-dependent macromolecular repair mechanisms combined with declining energy sources, intracellular ATP levels remained remarkably constant during heat shock. In conclusion, the sequential loss of replication and viability at 48oC cannot be explained by significant reductions in intracellular ATP levels, but may reflect ATP rerouting for macromolecular repair mechanisms and cell survival. Our metabolic model also suggests that heat-stressed S. aureus should down-regulate the production of potential, DNA-damaging reactive oxygen species that might result from electron transport-generated ATP, involving excessive levels of free heavy metals, in particular iron. Keywords: Staphylococcus aureus; heat shock; stress responses; transcriptomic profiling; physiological adjustment Comparative transcriptomic profiling of late log phase cultures of S. aureus ISP794, exposed to 43°C vs. 37°C, or 48°C vs. 37°C. We performed triplicate measurements from independently grown cultures for each heat stress condition.
2010-06-19 | E-GEOD-12920 | biostudies-arrayexpress
Project description:Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig colonization by MRSA ST398 is poorly understood. Previously, we developed a nasal colonization model of porcine nasal mucosa explants to identify molecular traits involved in nasal MRSA colonization of pigs. Here, we report the analysis of the transcriptome of MRSA ST398 strain S0462 during colonization on the explant epithelium. Major regulated genes were encoding metabolic processes and regulation of these genes represents metabolic adaptation to nasal mucosa explants. Colonization was not accompanied by significant changes in transcripts of main virulence associated genes or known human colonization factors. Here, we document regulation of two genes which have potential influence on S. aureus colonization; cysteine extracellular proteinase (scpA) and von Willebrand factor-binding protein (vwbp, located on SaPIbov5). Colonization with isogenic-deletion strains (Î?vwbp and Î?scpA) did not alter the nasal S. aureus colonization compared to wild type. Our results suggest that nasal colonization with MRSA ST398 is a complex event that is accompanied with changes in bacterial gene expression regulation and metabolic adaptation. Number of the samples: 5 (timepoint 0 min, 30 min, 60 min, 90 min and 180 min) in 4 replicates. 4 control samples
2015-12-31 | E-GEOD-47910 | biostudies-arrayexpress
Project description:Survival and pathogenesis of Staphylococcus aureus in the host requires the ability to respond to changes. Therefore, tight regulation of gene expression via various regulators is essential. Also, the organization of genes in operons is of influence on the regulation of gene expression. Knowledge of gene expression under different conditions and the ability to accurately predict operons are important steps towards understanding the transcriptional regulation, function and pathogenesis. A whole genome Agilent microarray was developed for the highly virulent, community-acquired MSSA476.During standard growth in a defined medium, we were able to determine four basic gene expression patterns of S. aureus for both virulence and non-virulence genes. In addition, we predicted operon structures by calculating Pearson correlation coefficients of the transcriptional profiles for all adjacent probes over all time points and replicas. In this study, we have set a basis for the knowledge on gene expression of MSSA476 during growth. Moreover, the correlation of time-dependent transcriptional profiles of adjacent probes seems to be a promising approach to predict operon structures. Five separate cultures of S. aureus mssa476 were grown. Of each replicate culture, samples were taken at 1, 2, 3, 4, 5, 6 and 9 h post inoculation (p.i.). In total, this amounts to 35 samples (7 time points in 5 replicates).
2010-06-24 | E-GEOD-16488 | biostudies-arrayexpress
Project description:We investigated the impact of cadmium on the global transcriptome of E. coli wild type, â??gshA and â??gshB mutant cells to evaluate the molecular basis of cadmium toxicity in the presence or absence of cellular thiols. This global transcriptome analysis were done with cells synthezising GSH (wild type), gamma-glutamyl-cysteine (â??gshB mutant) or neither of the two cellular thiols (â??gshA mutant) under the influence of 100 µM Cd(II). E. coli cells, wild type, â??gshA and â??gshB mutant strain, were grown at 37 °C . At a cell turbidity of 100 Klett, cells were treated for 10 min with 100 µM Cd(II) or no metal as a control in TMM medium. Total RNA was extracted, DNAse digested and reverse-transcribed with either Cy3- or Cy5-labeled dCTP. Both labeled cDNA were hybridized to a slide at 42 °C. All experiments were performed with three independent biological repeats.
2008-05-31 | E-GEOD-11562 | biostudies-arrayexpress
Project description:The function of the Staphylococcus aureus eukaryotic-like serine/threonine protein kinase PknB was investigated by transcriptome analysis using DNA-microarray technology and biochemical assays. The transcriptional profile reveals a strong regulatory impact of PknB on the expression of genes encoding proteins which are involved in purine and pyrimidine biosynthesis, cell wall metabolism, autolysis, and glutamine synthesis. To investigate the functional role of PknB in S. aureus DNA microarray experiments were performed. In this experiment, the impact of the deletion of PknB was investigated. Each experiment was performed 5 times including a dye swap resulting in five chips per competitive comparison to increase reproducibility. All hybridizations were done with equal amounts of cDNA probes.
2010-05-05 | E-GEOD-15346 | biostudies-arrayexpress