The Staphylococcus aureus Host Cell Genetic Adhesion Network
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Staphylococcus Aureus
SUBMITTER: 
Jennifer Geddes-McAlister
LAB HEAD: Jennifer Geddes-McAlister
PROVIDER: PXD018514 | Pride | 2023-03-04
REPOSITORIES: Pride
Similar Datasets
Project description:Proving functionality in the host environment is a crucial step in antimicrobial development pipelines. Antibiotics targeting fatty acid synthesis (FASII) of the major pathogen Staphylococcus aureus actively inhibit FASII but do not prevent in vivo growth, as bacteria compensate the FASII block by using environmental fatty acids. We used proteomics and phosphoproteomics to elucidate S. aureus responses to anti-FASII in host-relevant conditions. S. aureus responded to anti-FASII treatment in serum by massive reprogramming. A striking inverse correlation was observed in anti-FASII-adapted S. aureus, between amounts of stress response proteins that increase, and virulence factors that decrease. These findings suggest that anti-FASII adapted cells might be better prepared for survival and less equipped to damage the host. Infection by anti-FASII-adapted versus non-treated S. aureus was challenged in the Galleria mellonella model. Time to mortality was longer in insects infected by anti-FASII-treated bacteria compared to those infected by non-treated S. aureus. However, bacterial counts in infected dead insects were comparable for both groups. These results support the hypothesis that higher stress response and lower virulence factor expression, as shown here in FASII-antibiotic-adapted bacteria, may set the stage for persistent infection
2023-10-09 | PXD034256 | Pride
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:It has been shown that inbred strains of mice exhibit variable susceptibility to S. aureus infection, but the specific genes responsible for this differential phenotype are unknown. Using ISHM to identify genomic regions associated with the phenotypes, we considered genes within those interval to be candidate genes and used the gene expression patterns of the genes contained in the region to determine whether the genes are differentially expressed between the 2 phenotypically different groups of mice. To identify genes differentially expressed between mice susceptible and resistant to S. aureus infection that could contribute to host susceptibility to S. aureus infection, we compared the gene expression profiles between 2 groups of mice where 3 were susceptible (A/J, BALBcBy/J, AKR/J) and resistant (C57BL/J, C3H/HeJ, NOD/ShiLtJ) to S. aureus. The susceptible group had high bacterial count values in the kidney while the resistant group had low values.
2011-12-31 | E-GEOD-23584 | biostudies-arrayexpress
Project description:Although it has recently been shown that A/J mice are highly susceptible to Staphylococcus aureus sepsis as compared to C57BL/6J, the specific genes responsible for this differential phenotype are unknown. Using chromosome substitution strains (CSS), we found that factors on chromosomes (chr) 8, 11, and 18 are responsible for susceptibility to S. aureus sepsis in A/J mice. F1 mice from C57BL/6J X CSS8 cross (C8A) and C57BL/6J X CSS18 (C18A) were also susceptible to S. aureus (median survival < 48 h), whereas F1 mice from C57BL/6J X CSS11 cross (C11A) were resistant (median survival > 120 h) to S. aureus. Bacterial loads in the kidney were consistent with F1 median survivals, with higher bacterial counts in susceptible mice. No sexlinked associations with susceptibility were noted in F1 intercrosses. Using whole genome transcription profiling, we identified a total of 192 genes on chromosomes 8, 11, and 18 which are differentially expressed between A/J and C57BL/6J in the setting of S. aureus infection. Of these, 28 genes had Gene Ontology annotations indicating a potential immune response function. These 28 genes are associated with susceptibility to S. aureus in A/J mice, and are potential determinants of susceptibility to S. aureus infection in humans. To identify genes for which differential expression between A/J and C57BL/6J mice could contribute to host susceptibility to S. aureus infection, we compared the gene expression profiles between uninfected A/J and C57BL/6J mice and between infected A/J and C57BL/6J mice at 2, 4, 6, and 12 hours after infection.
2010-08-01 | E-GEOD-19668 | 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: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:Staphylococcus aureus causes a spectrum of human infection. Diagnostic delays and uncertainty lead to treatment delays and inappropriate antibiotic use. A growing literature suggests the hostM-bM-^@M-^Ys inflammatory response to the pathogen represents a potential tool to improve upon current diagnostics. The hypothesis of this study is that the host responds differently to S. aureus than to E. coli infection in a quantifiable way, providing a new diagnostic avenue. This study uses Bayesian sparse factor modeling and penalized binary regression to define peripheral blood gene-expression classifiers of murine and human S. aureus infection. The murine-derived classifier distinguished S. aureus infection from healthy controls and Escherichia coli-infected mice across a range of conditions (mouse and bacterial strain, time post infection) and was validated in outbred mice (AUC>0.97). A S. aureus classifier derived from a cohort of 95 human subjects distinguished S. aureus blood stream infection (BSI) from healthy subjects (AUC 0.99) and E. coli BSI (AUC 0.82). Murine and human responses to S. aureus infection share common biological pathways, allowing the murine model to classify S. aureus BSI in humans (AUC 0.84). Both murine and human S. aureus classifiers were validated in an independent human cohort (AUC 0.95 and 0.94, respectively). The approach described here lends insight into the conserved and disparate pathways utilized by mice and humans in response to these infections. Furthermore, this study advances our understanding of S. aureus infection; the host response to it; and identifies new diagnostic and therapeutic avenues. To create a host gene expression-based classifier for S. aureus infection, mice from a variety of experimental conditions were utilized. Seven different strains of inbred mice (n=187 total) were challenged with four different S. aureus strains via intraperitoneal inoculation and sacrificed at various time points as described in Methods. The comparator group for model derivation included 50 A/J or C57BL/6J mice inoculated with E. coli (O18:K1:H7) as well as 54 uninfected mice. Next, the murine S. aureus classifier was externally validated in outbred CD-1 mice with S. aureus infection (Sanger 476 or USA300), E. coli infection (O18:K1:H7), or uninfected controls (10 animals per condition). Method: All experiments were performed on mice 6-8 weeks old. For the murine S. aureus predictor, seven inbred mouse strains (3 mice/strain: 129S1/SvImJ, A/J, AKR/J, BALB/cByJ, C57BL/6J, C3H/HeJ, and NOD/LtJ) were IP inoculated with 107 CFU/g of S. aureus Sanger476, euthanized at 2h after injection, and bled. This was repeated using four different S. aureus strains (USA100, USA300, MW2, and Sanger476) in A/J mice (n=3 per S. aureus strain). For time series experiments, both A/J and C57BL/6J mouse strains were IP inoculated with S. aureus Sanger476 as above, and sacrificed at 2, 4, 6, and 12h after injection (n=5 per time point).
2013-01-11 | E-GEOD-33341 | biostudies-arrayexpress
Project description:Nicotinamide adenine dinucleotide phosphate (NADPH) is the primary electron donor for reductive reactions that are essential for the biosynthesis of major cell components in all organisms. Nicotinamide adenine dinucleotide kinase (NADK) is the only enzyme that catalyzes synthesis of NADP(H) from NAD(H). While the enzymatic properties and physiological functions of NADK have been thoroughly studied, the role of NADK in bacterial pathogenesis remains unknown. Here, we used CRISPR interference to knockdown NADK gene expression to address the role of this enzyme in Staphylococcus aureus pathogenic potential. We find that NADK inhibition drastically decreases mortality of zebrafish infected with S. aureus. Further, we show that NADK promotes S. aureus survival in infected macrophages by protecting bacteria from antimicrobial defense mechanisms. Proteome-wide data analysis revealed that production of major virulence associated factors is sustained by NADK. We demonstrate that NADK is required for expression of the quorum-sensing response regulator AgrA, which controls critical S. aureus virulence determinants. These findings support a key role for NADK in bacteria survival within innate immune cells and the host during infection.
2022-08-12 | PXD032968 | Pride
Project description:Polymicrobial infections are intrinsically less susceptible to antimicrobial therapy, are more invasive and can induce enhanced inflammatory responses leading to negative clinical outcomes. The importance of studying the interaction between microbes themselves and their interactions with their host in combination has only been realised in recent years. However, there is a lack of simple, effective and low cost in vivo models to study these interactions with the host immune response. This study details the responses of Galleria mellonella larvae to disseminated combination infection by C. albicans and S. aureus and demonstrates the efficacy of antimicrobial chemotherapy on treating co-infected larvae. Doses of C. albicans (1 × 105 larva-1) and S. aureus (1 × 104 larva-1) which were non-lethal in mono-infection, when combined significantly lowered larval survival at (70 ± 3.33% [p < 0.01]), 48 (10 ± 3.33% [p < 0.0001]) and 72h (5 ± 6.66% [p < 0.0001]) h relative to larvae receiving S. aureus 2 × 104 larva-1 mono-infection. Co-infected larvae with S. aureus 2 × 104 larva-1 resulted in an increase in the density of circulating hemocytes relative to S. aureus mono-infected larvae. Co-infected larvae displayed a significantly higher overall S. aureus c.f.u larva-1 compared to larvae only infected with S. aureus. Co-infection resulted in dissemination throughout the host and the appearance of large nodules. Proteomic analysis of co-infected larval hemolymph revealed specific immune responses to bacterial and fungal infection by the increased abundance of a range of antimicrobial peptides, peptidoglycan, lipopolysaccharide and β-glucan recognition proteins and proteins associated with tissue invasion and nodule formation. The in vitro and in vivo efficacy of empirical antimicrobial drugs (amphotericin B & meropenem) was examined against C. albicans and S. aureus was also examined. meropenem was more effective than amphotericin B but a combination was most effective at improving survival of co-infected larvae. The effect of antimicrobial therapy on symptoms associated with co-infection was also assessed using Cryo-imaging. The processes of polymicrobial co-infection in G. mellonella are compared to those in mice models and larvae provide an easy to use and ethically acceptable in vivo system to assess polymicrobial interactions with their host.
2020-02-24 | PXD014273 | Pride
Project description:It is becoming increasingly apparent that Staphylococcus aureus are able to survive engulfment by macrophages, and that the intracellular environment of these cells, which is essential to innate host defenses against invading microorganisms, may in fact provide a refuge for staphylococcal survival and dissemination. Based on this, we postulated that S. aureus might induce cytoprotective mechanisms by changing gene expression profiles inside macrophages similar to obligate intracellular pathogens, such as Mycobacterium tuberculosis. In order to examine the effect of S. aureus on the macrophage transcriptome, we performed microarray expression analysis on human monocyte-derived macrophages treated with S. aureus. Experiment Overall Design: Human monocyte-derived macrophages (hMDMs) were separated from fractions of peripheral blood mononuclear cells (PBMCs) obtained from the blood of healthy donors. Control and S. aureus-exposed macrophages were incubated at 37C for 8, 24, or 48 hours
2009-05-02 | E-GEOD-13670 | biostudies-arrayexpress