Resistant isolates of methicillin-resistant Staphylococcus aureus (MRSA)
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Q-Exactive (Thermo Fisher)
ORGANISM(S): Methicillin-resistant Staphylococcus Aureus (mrsa)
SUBMITTER: 
Ana Flavia Marques Pereira Bruno Cesar Rossini Lucilene Delazari dos Santos Ary Fernandes Junior
PROVIDER: MSV000092035 | MassIVE | Thu May 25 16:56:00 BST 2023
REPOSITORIES: MassIVE
Similar Datasets
Project description:Whole-genome analysis by 62-strain microarray showed variation in resistance and virulence genes on mobile genetic elements (MGEs) between 40 isolates of methicillin-resistant Staphylococcus aureus (MRSA) strain CC22-SCCmecIV but also showed (i) detection of two previously unrecognized MRSA transmission events and (ii) that 7/8 patients were infected with a variant of their own colonizing isolate. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-128]
2012-10-29 | E-BUGS-128 | biostudies-arrayexpress
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:<p>The discovery of antibiotics has led to the effective treatment of bacterial infections that were otherwise fatal and has had a transformative effect on modern medicine. Teixobactin is an unusual depsipeptide natural product that was recently discovered from a previously unculturable soil bacterium which is active against several Gram-positive pathogens, including methicillin- resistant Staphylococcus aureus and vancomycin-resistant Enterococci. One of the key attractive features of teixobactin as an antibiotic lead is that resistance could not be generated in a laboratory setting against S. aureus. This is proposed to be a result of the mechanism of action that involves binding to essential bacterial cell wall synthesis building blocks lipid II and lipid III.</p><p>In the present study, metabolomics was used to investigate the potential metabolic pathways and mode of action involved in mechanisms of antibacterial activity and bacterial killing of the synthetic teixobactin analog Leu10-teixobactin against an MRSA strain, S. aureus ATCC700699. The metabolomes of S. aureus ATCC700699 cells were compared at 1, 3 and 6 h following treatment with Leu10-teixobactin (0.5 µg/ml, i.e. 0.5x MIC) and the untreated controls. Leu10-teixobactin significantly perturbed bacterial membrane lipids (glycerophospholipids and fatty acids), peptidoglycan (lipid I and II) metabolism and cell wall teichoic acid (lipid III) biosynthesis as early as after 1 h of treatment reflecting an initial activity on the cell envelope. Concordant with its time-dependent antibacterial killing action, Leu10-teixobactin caused more perturbations in the levels of key intermediates in pathways of amino-sugar and nucleotide-sugar metabolism and their downstream peptidoglycan and teichoic acid biosynthesis at 3 and 6 h. Significant perturbations in arginine metabolism and interrelated tricarboxylic acid cycle, histidine metabolism, pantothenate and Coenzyme A biosynthesis were also observed at 3 and 6 h.</p><p>To conclude, this is the first study to provide novel metabolomics mechanistic information which lends to support the development of teixobactin as an antibacterial drug for the treatment of multi-drug resistant Gram-positive infections.</p>
2020-04-30 | MTBLS1569 | MetaboLights
Project description:To establish general differences between the protein expression in S. aureus strains, five methicillin sensitive S. aureus (MSSA) strains and five methicillin resistant S. aureus (MRSA) strains were compared both individually and as MSSA and MRSA groups in the absence of antibiotics. Proteins were compared by ultra-performance liquid chromatography-mass spectrometry.
2023-04-25 | PXD021629 | Pride
Project description:Methicillin-resistant Staphylococcus aureus is one of the major causative agents associated to infections with a high morbidity and mortality in hospitals worldwide. In previous studies, we reported that lignan 3'-demethoxy-6-O-demethylisoguaiacin isolated and characterized from Larrea tridentata showed the best activity towards methicillin-resistant S. aureus. Understanding of mechanism of action of drugs allows design drugs in a better way. Therefore, we employed microarray to obtain gene expression profile of methicillin-resistant S. aureus after exposure to 3'-demethoxy-6-O-demethylisoguaiacin. The results showed that lignan had an effect on cell membrane affecting proteins of the ATP-binding cassette (ABC) transport system causing bacteria death. This study consisted of comparison of isolated RNA of MRSA not treated and MRSA treated with lignan 3'-demethoxy-6-O-demethylisoguaiacin. Both RNAs samples were differentially dyed with Cy3 and Cy5 during cDNA synthesis and hybridized on DNA chip. Afterwards, the chip was scanned in a GenePix 4000B scanner. The resulting gene expression profile was analyzed in databases for functional annotations to find a potential mechanism of the lignan in MRSA.
2015-06-27 | E-GEOD-70309 | biostudies-arrayexpress
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen in both community and health care settings, which causes a wide range of infections. Its resistance to β-lactam antibiotics and methicillin in particular, greatly complicates treatment options and success rate due to the limited number of antibiotics with activity against MRSA. To further the development of alternative therapeutics, the mechanisms that mediate antibiotic resistance in MRSA need to be fully understood. Cannabinoid compounds including cannabidiol (CBD), tetrahydrocannabinol (THC) and cannabinol (CBN) have shown promise as potential antibiotic adjuvants. In the present study, MRSA cells were subjected to antibiotic stress from methicillin in combination with three cannabinoid compounds, and subsequently analysed using metaproteomics to assess the metabolic response. Subjecting MRSA to methicillin made the cells more viable and increased their energy production, as well as upregulation of penicillin-binding protein 2 (PBP2). The cannabinoids all showed antimicrobial activity against MRSA, and inhibited the energy production of the cells as well as PBP2 when used in combination with methicillin. Furthermore, all three cannabinoid compounds inhibited resistance mechanisms in MRSA, resulting in a decrease in the minimum inhibitory concentration (MIC) of methicillin when used in combination.
2022-01-18 | PXD024244 | 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 potentiate 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. To gain biological insight into how this potentiation and biofilm inhibition occurs, we used RNA-seq on treated MRSA 43300 cultures to examine antibiotic adjuvant affects transcritome-wide.
2023-03-23 | GSE227099 | GEO
Project description:The aqueous extract of yerba mate, a South American tea beverage made from Ilex paraguariensis leaves, has demonstrated bactericidal and inhibitory activity against bacterial pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). The gas chromatography-mass spectrometry (GC-MS) analysis of two unique fractions of yerba mate aqueous extract revealed 8 identifiable small molecules in those fractions with antimicrobial activity. For a more comprehensive analysis, a data analysis pipeline was assembled to prioritize compounds for antimicrobial testing against both MRSA and methicillin-sensitive S. aureus using forty-two unique fractions of the tea extract that were generated in duplicate, assayed for activity, and analyzed with GC-MS. As validation of our automated analysis, we checked our predicted active compounds for activity in literature references and with used authentic standards to test for antimicrobial activity. 3,4-dihydroxybenzaldehyde showed the most antibacterial activity against MRSA at low concentrations in our bioassays. In addition, quinic acid and quercetin were identified using random forests analysis and 5-hydroxy pipecolic acid was identified using linear discriminant analysis. We additionally also generated a ranked list of unidentified compounds that may contribute to the antimicrobial activity of yerba mate against MRSA. Here we utilized GC-MS data to implement an automated analysis that resulted in a ranked list of compounds that likely contribute to the antimicrobial activity of aqueous yerba mate extract against MRSA.
2015-03-19 | MTBLS170 | MetaboLights
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is a highly prioritized pathogen proposed by World Health Organization (WHO). It is listed to encourage researchers to search for effective antimicrobial agents. Previously, we isolated soil Brevibacillus sp. strain SPR19, which showed anti-MRSA activity. However, the active substances were still unknown. This study aimed to isolate and identify the anti-MRSA substances from this bacterium. The cell-free supernatant of SPR19 was subjected to salt precipitation, cation exchange, and re-versed-phase chromatography. Bioassay-guided fractionation was used to screen active sub-stances
2023-08-31 | PXD042035 | Pride
Project description:Rhodomyrtone, purified from Rhodomyrtus tomentosa (Aiton) Hassk, exhibits a high degree of potency against methicillin-resistant Staphylococcus aureus (MRSA). We recently demonstrated that exposure of MRSA to a subinhibitory concentration (0.174 µg/ml) of rhodomyrtone resulted in the alteration of expression of several functional classes of bacterial proteins. To provide further insight into the antibacterial mode of action of this compound, we determined the impact of exposure to rhodomyrtone on the gene transcriptional profile of MRSA using microarray analysis. Exposure of MRSA to subinhibitory concentrations (0.5MIC; 0.5 µg/ml) of rhodomyrtone revealed significant modulation of gene expression, with induction of 64 genes and repression of 35 genes. Prominent changes in response to exposure to rhodomyrtone involved genes encoding proteins essential to metabolic pathways and processes such as amino acid metabolism, membrane function, ATP-binding cassette (ABC) transportation and lipoprotein and nucleotide metabolism. Genes involved in the synthesis of the aspartate family of amino acids, in particular proteins encoded by the dap operon were prominent. The diaminopimelate (DAP) biosynthetic pathway is the precursor of lysine synthesis and is essential for peptidoglycan biosynthesis. However, phenotypic analysis of the peptidoglycan amino acid content of rhodomyrtone-treated MRSA did not differ significantly from that extracted from control cells. Genes involved in the biosynthesis of amino acids and peptidoglycan, and a high affinity ATP-driven K (+) transport system, were investigated by quantitative reverse transcription-PCR (qRT-PCR) using EMRSA-16 1, 4, or 18 h after exposure to rhodomyrtone and in general the data concurred with that obtained by microarray, highlighting the relevance of the DAP biosynthetic pathway to the mode of action of rhodomyrtone. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-136]
2012-10-14 | E-BUGS-136 | biostudies-arrayexpress