Comparison of the oxacillin stress response in vraS and vraT mutants
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ABSTRACT:
ORGANISM(S): Staphylococcus aureus subsp. aureus USA300 Staphylococcus aureus
PROVIDER: GSE39627 | GEO | 2012/11/30
SECONDARY ACCESSION(S): PRJNA171298
REPOSITORIES: GEO
Similar Datasets
Project description:To determine the role of the second gene in the vra operon (vraT) in the stress response to oxacillin, we compared the oxacillin induction profiles in a vraT deletion strain to that of a vraSR mutant in a USA300 MRSA strain background. Nonpolar deletion of vraT and insertional inactivation of vraS was constructed in MRSA strain USA300.
2012-11-30 | E-GEOD-39627 | biostudies-arrayexpress
Project description:In the community and clinical settings MRSA infections are more commonly caused by a USA300 strain vs a USA400 strain. The study aims to compare gene expression patterns of Staphyloccoccus aureus USA300(reference) vs USA400(query) and to determine why USA400 is being replaced by a USA300 strain.
2011-04-08 | GSE26255 | GEO
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.
2017-11-15 | GSE102279 | GEO
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) remains a global health threat with an over 14% fatality rate, in case of invasive infection, in 2011. Multi-drug resistance is the main reason for the failure of therapy. Use of antimicrobial drug combinations with synergistic effect is increasingly seen as a critical strategy to combat multi-drug resistant pathogens such as MRSA. However, the mechanism of synergistic effect has yet been systematically studied. In this work, we investigated a new erythromycin derivative, SIPI-8294, which has been demonstrated to have synergistic effect with oxacillin against MRSA, unlike its parent compound erythromycin. To obtain insights into the mechanism for the synergistic effect, label-free quantitative proteomics was employed. Cultured MRSA was exposed to sub-inhibitory doses of oxacillin, SIPI-8294, erythromycin, and combinations of SIPI-8294/oxacillin and erythromycin/oxacillin to reveal the global proteome responses to drug treatment. Results showed that 200 proteins were differentially expressed in SIPI-8294/oxacillin-treated cells. Among these proteins, the expression levels of penicillin binding protein 2a and β-lactamase, two proteins mainly responsible for oxacillin resistance, were four times lower in the SIPI-8294/oxacillin treatment group than in the erythromycin/oxacillin treatment group. Quantitative real-time PCR analysis also revealed similar trends at the transcription level. These results suggest that the synergistic mechanism may be related to interference with the known oxacillin resistance mechanism. The data also provided some evidence that the combination of SIPI-8294 and oxacillin appears to impact oxidation-reduction homeostasis and cell wall biosynthesis.
2022-03-01 | PXD001494 | Pride
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is a major threat to human health. Rather than depend on creating new antibiotics (to which bacteria will eventually become resistant), we are employing antibiotic adjuvants that potentiation existing antibiotics. Based on our previous work, loratadine, the FDA-approvide antihistamine, effectively potentiates cell-wall active antibiotics in multiple strains of MRSA. Furthermore, loratadine and oxacillin helped disrupt preformed biofilms and stop them from initially forming in vitro. A structurally related brominated carbazole, compound 8, showed similar antibiotic potentiation. To gain biological insight into these transcriptome disruptors in a more clinically relevant strain of MRSA, we used RNA-seq on treated MRSA USA100 cultures.
2024-05-15 | GSE267020 | GEO
Project description:In the community and clinical settings MRSA infections are more commonly caused by a USA300 strain vs a USA400 strain. The study aims to compare gene expression patterns of Staphyloccoccus aureus USA300(reference) vs USA400(query) and to determine why USA400 is being replaced by a USA300 strain. The USA300 and USA400 isolates were grown in TSA media to early log, mid log, late log and stationary phase. RNA samples were extracted and samples were hybridized on aminosilane coated slides with 70-mer oligos. Differential gene expression patterns were compared between the two strains.
2011-04-08 | E-GEOD-26255 | biostudies-arrayexpress
Project description:Little is known about the expression of methicillin-resistant Staphylococcus aureus (MRSA) genes during infection conditions. Here, we described the transcriptome of the clinical MRSA strain USA300 derived from human cutaneous abscesses, and compared it with USA300 bacteria derived from infected kidneys in a mouse model. Remarkable similarity between the transcriptomes allowed us to identify genes encoding multiple proteases and toxins, and iron- and peptide-transporter molecules, which are upregulated in both infections and are likely important for establishment of infection. We also showed that disruption of the global transcriptional regulators agr and sae prevents in vivo upregulation of many toxins and proteases, protecting mice from lethal infection dose, and hinting at the role of these transcriptional regulators in the pathology of MRSA infection.
2015-10-16 | GSE73821 | GEO
Project description:Introduction Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are increasingly isolated, with USA300-0114 being the predominant clone in the USA. Comparative whole genome sequencing of USA300 isolates collected in 2002, 2003 and 2005 showed a limited number of single nucleotide polymorphisms and regions of difference. This suggests that USA300 has undergone rapid clonal expansion without great genomic diversification. However, whole genome comparison of CA-MRSA has been limited to isolates belonging to USA300. The aim of this study was to compare the genetic repertoire of different CA-MRSA clones with that of HA-MRSA from the USA and Europe through comparative genomic hybridization (CGH) to identify genetic clues that may explain the successful and rapid emergence of CA-MRSA. Materials and Methods Hierarchical clustering based on CGH of 48 MRSA isolates from the community and nosocomial infections from Europe and the USA revealed dispersed clustering of the 19 CA-MRSA isolates. This means that these 19 CA-MRSA isolates do not share a unique genetic make-up. Only the PVL genes were commonly present in all CA-MRSA isolates. However, 10 genes were variably present among 14 USA300 isolates. Most of these genes were present on mobile elements. Conclusion The genetic variation present among the 14 USA300 isolates is remarkable considering the fact that the isolates were recovered within one month and originated from a confined geographic area, suggesting continuous evolution of this clone. Data is also available from <ahref=http://bugs.sgul.ac.uk/E-BUGS-108 target=_blank>BuG@Sbase</a>
2011-04-15 | E-BUGS-108 | biostudies-arrayexpress
Project description:The success of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) as pathogens is due to a combination of antibiotic resistance with high virulence. However, evolution of the exceptional virulence potential of CA-MRSA is not understood. Our previous study indicated that differential gene expression contributes substantially to this process. Thus, we here investigated the role of the pivotal virulence gene regulatory system agr in the most prevalent CA-MRSA strain USA300. Using a mouse subcutaneous infection model, we show that agr is essential for the development of CA-MRSA skin infections, the most frequent manifestation of disease caused by CA-MRSA. Furthermore, genome-wide analysis of gene expression revealed significant differences in agr-dependent virulence gene regulation between CA-MRSA, HA-MRSA, and laboratory strains. Our findings demonstrate that agr functionality is critical for CA-MRSA disease and indicate that an adaptation of the agr regulon to optimize expression of a broad set of virulence determinants may have contributed to the evolution of exceptionally pronounced virulence of CA-MRSA strains. Keywords: wild type vs mutant
2011-03-29 | GSE18793 | GEO