Lytic Effect of Terpeneless Cold Pressed Valencia Orange Oil on Methicillin-Resistant Staphylococcus aureus
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ABSTRACT:
ORGANISM(S): Staphylococcus aureus
PROVIDER: GSE33465 | GEO | 2011/11/08
SECONDARY ACCESSION(S): PRJNA148783
REPOSITORIES: GEO
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Project description:Staphylococcus aureus has been recognized as an important cause of human disease for more than 100 years. Resistance to multiple classes of antibiotics is becoming an increasingly difficult problem in the management of methicillin-resistant S. aureus (MRSA) and vancomycin-intermediate resistant S. aureus (VISA) infections. One approach to the MRSA and VISA problem, involves the discovery and development of new natural antimicrobials. The antimicrobial properties of essential oils of plant origin have been recognized for many years. In this study 0.1% of commercial cold pressed terpeneless Valencia orange oil (CPV) showed inhibitory and lytic activity against MRSA and VISA. To identify the mechanisms of action of CPV genomic response of CPV treated MRSA was analyzed by transcriptional profiling. Results showed alteration in the expression of cell wall peptidoglycan biosynthesis associated genes in the CPV treated cells. Transmission electron microscopic observation of CPV treated MRSA cells exhibited cell wall damage and cell lysis. Overall results of this study suggest that CPV may be a potential anti-staphylococcal agent for MRSA. Overnight grown S. aureus COL was inoculated in TSB medium (20 ml) in a 50 ml Erlenmeyer flask and incubated at 37°C, with shaking at 200 rpm. Growth was measured at regular intervals at 600 nm until OD reached approximately 0.4. Based on the GIC study ½ x MIC concentration of EO was added for 15 min of challenge. Control cultures were not challenged with EO and were also incubated for 15 min. Total bacterial RNA was isolated as previously described and the RNA samples were then converted to fluorescently-labeled cDNA and hybridized to S. aureus microarrays version 6 (NIAID's Pathogen Functional Genomics Resource Center). Hybridization signals were scanned using an Axon4000B scanner (Molecular Devices, Sunnyvale, CA ) with Acuity 6.0 software and scans were saved as TIFF image. Scans were analyzed using TIGR-Spotfinder (www.tigr.org/software/) software and the local background was subsequently subtracted. The data set was normalized by applying the LOWESS algorithm using TIGR-MIDAS (www.tigr.org/software/) software. The normalized log2 ratio of test/reference signal for each spot was recorded. Genes with less than three data points were considered unreliable, and their data points were discarded. The averaged log2 ratios for each remaining gene on the 6 replicate slides were ultimately calculated. Significant changes of gene expression were identified with SAM (significance analysis of microarrays; www.tat.stanford.edu/~tibs/SAM/index.html. Contents of raw data files: Channel A = Cy3 dye Channel B = Cy5 dye
2011-11-08 | E-GEOD-33465 | biostudies-arrayexpress
Project description:Staphylococcus aureus is an adaptable human pathogen causing life-threatening endocarditis and bacteraemia. Methicillin-resistant S. aureus (MRSA) is alarmingly common, and treatment is confined to last-line antibiotics. Vancomycin is the treatment of choice for MRSA bacteraemia and vancomycin treatment failure is often associated with vancomycin-intermediate S. aureus strains termed VISA. The regulatory 3’ UTR of vigR mRNA contributes to vancomycin tolerance in the clinical VISA isolate JKD6008 and upregulates the lytic transglycosylase IsaA. Using MS2-affinity purification coupled with RNA sequencing (MAPS), we find that the vigR 3' UTR also interacts with mRNAs involved in carbon metabolism, amino acid biogenesis, cell wall biogenesis, and virulence. The vigR 3' UTR was found to repress dapE, a succinyl-diaminopimelate desuccinylase required for lysine and cell wall peptidoglycan synthesis, suggesting a broader role in controlling cell wall metabolism and vancomycin tolerance. Deletion of the vigR 3' UTR increased VISA virulence in a wax moth larvae model, and we find that an isaA mutant is completely attenuated in the larvae model. Sequence and structural analysis of the vigR 3' UTR indicates that the UTR has expanded through the acquisition of Staphylococcus aureus repeat insertions (STAR repeats) that partly contribute sequence for the isaA interaction seed and may functionalise the 3’ UTR. Our findings reveal an extended regulatory network for vigR, uncovering a novel mechanism of regulation of cell wall metabolism and virulence in a clinical S. aureus isolate.
2024-02-20 | GSE252940 | GEO
Project description:Subinhibitory concentrations of the neuroleptic drug thioridazine (TDZ) are well-known to enhance the killing of methicillin-resistant S. aureus (MRSA) by β-lactam antibiotics, however, the mechanism underlying the synergy between TDZ and β-lactams is not fully understood. In the present study we have examined the effect of a subinhibitory concentration of TDZ on antimicrobial resistance, the global transcriptome, and the cell wall composition of MRSA USA300. We show that TDZ is able to sensitize the bacteria to several classes of antimicrobials targeting the late stages of peptidoglycan synthesis. Furthermore, our microarray analysis demonstrates that TDZ modulates the expression of genes encoding membrane and surface proteins, transporters, and enzymes involved in amino acid biosynthesis. Interestingly, resemblance between the transcriptional profile of TDZ treatment and the transcriptomic response of S. aureus to known inhibitors of cell wall synthesis suggests that TDZ disturbs peptidoglycan biosynthesis at a stage that precedes transpeptidation. In support of this notion, dramatic changes in the muropeptide profile of USA300 were observed following growth in the presence of TDZ, indicating that TDZ can interfere with the formation of the pentaglycine branches. Strikingly, the addition of glycine to the growth medium relieved the effect of TDZ on the muropeptide profile. Furthermore, exogenous glycine offered a modest protective effect against TDZ-induced β-lactam sensitivity. We propose that TDZ exposure leads to a shortage of intracellular amino acids, including glycine, which is required for the production of normal peptidoglycan precursors with pentaglycine branches, the correct substrate of S. aureus penicillin-binding proteins. Collectively, this work demonstrates that TDZ has a major impact on the cell wall biosynthesis pathway in S. aureus and provides new insights into how MRSA may be sensitized towards β-lactam antibiotics. Staphylococcus aureus USA300 was grown to early exponential phase and treated with TDZ (16 µg/ml) alone or in combination with DCX (0.125 µg/ml) for 30 min. Changes in global gene expression were analyzed using the untreated culture as control. Hybridizations were performed in triplicate using RNA isolated from independent cultures.
2013-05-20 | E-GEOD-43759 | biostudies-arrayexpress
Project description:The lantibiotic mersacidin is an antimicrobial peptide of 20 amino acids that is produced by Bacillus sp. strain HIL Y-85,54728. Lantibiotics are antibiotics containing nonproteinogenic amino acids like lanthionine and/or 3-methyllanthionine. Mersacidin interferes with cell wall biosynthesis by targeting the peptidoglycan precursor lipid II and inhibits the growth of MRSA and other gram-positive bacteria. Therefore, mersacidin could be a lead substance for the development of new antibacterial agents. The clinical VISA isolates S. aureus 137/93A and its spontaneous mutant S. aureus 137/93G show reduced sensitivity towards mersacidin. This phenotype could not be traced to factors being responsible for vancomycinresistance (i.e. the thickened cell wall). Here, we focussed on the comparative transcriptome analysis of S. aureus 137/93A and S. aureus SG511 (sensitive strain) via full genome S. aureus microarrays to identify genes involved in the reduced sensitivity towards mersacidin.
2009-01-17 | GSE12016 | GEO
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:Subinhibitory concentrations of the neuroleptic drug thioridazine (TDZ) are well-known to enhance the killing of methicillin-resistant S. aureus (MRSA) by β-lactam antibiotics, however, the mechanism underlying the synergy between TDZ and β-lactams is not fully understood. In the present study we have examined the effect of a subinhibitory concentration of TDZ on antimicrobial resistance, the global transcriptome, and the cell wall composition of MRSA USA300. We show that TDZ is able to sensitize the bacteria to several classes of antimicrobials targeting the late stages of peptidoglycan synthesis. Furthermore, our microarray analysis demonstrates that TDZ modulates the expression of genes encoding membrane and surface proteins, transporters, and enzymes involved in amino acid biosynthesis. Interestingly, resemblance between the transcriptional profile of TDZ treatment and the transcriptomic response of S. aureus to known inhibitors of cell wall synthesis suggests that TDZ disturbs peptidoglycan biosynthesis at a stage that precedes transpeptidation. In support of this notion, dramatic changes in the muropeptide profile of USA300 were observed following growth in the presence of TDZ, indicating that TDZ can interfere with the formation of the pentaglycine branches. Strikingly, the addition of glycine to the growth medium relieved the effect of TDZ on the muropeptide profile. Furthermore, exogenous glycine offered a modest protective effect against TDZ-induced β-lactam sensitivity. We propose that TDZ exposure leads to a shortage of intracellular amino acids, including glycine, which is required for the production of normal peptidoglycan precursors with pentaglycine branches, the correct substrate of S. aureus penicillin-binding proteins. Collectively, this work demonstrates that TDZ has a major impact on the cell wall biosynthesis pathway in S. aureus and provides new insights into how MRSA may be sensitized towards β-lactam antibiotics.
2013-05-20 | GSE43759 | GEO
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:Daptomycin (DAP) is the last-resort treatment for heterogeneous Vancomycin-Intermediate-Staphylococcus aureus (hVISA) and Vancomycin-Intermediate-S.aureus (VISA), and DAP-resistance onset which is also linked to reduced vancomycin susceptibility, is an increasing public health problem. To have more insight into the mechanisms of daptomycin resistance, the comparative transcriptomes of two DAP-R (1C-3B) clinical isogenic isolates vs their DAP-S (1A-3A) counterparts were investigated by Illumina RNA-seq, the Rockhopper tool, computational filtering analyses and bioinformatic tools.
2020-08-07 | GSE121797 | GEO
Project description:The phenotype “intermediate vancomycin resistance” in Staphylococcus aureus (CLSI: MIC = 4-8 mg/L) has been assigned to changes that lead to alterations in cell wall synthesis and morphology. Most vancomycin intermediately resistant S. aureus (VISA) strains are characterised by an increased cell wall thickness as a consequence of an activated cell wall biosynthesis and decreased autolysis. The purpose of this study was to analyse the genetic basis of the vancomycin resistance mechanism of the clinical VISA isolate SA137/93A and its spontaneous mutant strain SA137/93G. The methicillin-resistant S. aureus (MRSA) SA137/93A was isolated from a tracheal secretion and displays heterogeneous intermediate vancomycin resistance (hVISA strain, MIC: 8 mg/L in BHI). Subculturing in presence of 6 mg/L vancomycin generated a mutant with homogeneous intermediate vancomycin resistance, that showed an MIC value of 16 mg/L in BHI and was designated SA137/93G. PFGE profiles and phage typing of the strains showed that they were members of the Iberian clone (ST247), which was prevalent in Germany in the early nineties under the designation “Northern German epidemic strain”. Both strains possess a thickened cell wall. However, the vancomycin resistance of strain SA137/93A is most probably enhanced by an increased amount of free D-Ala-D-Ala termini in the cell wall, which is due to decreased crosslinking, whereas the mutant strain SA137/93G shows normal crosslinking. Moreover, strain SA137/93A displays an increased expression of the essential two-component system yycFGHI as a consequence of an IS256 insertion in the promoter region, while strain SA137/93G is characterised by an insertion of IS256 into the gene tcaA. Although both insertions were shown to correlate with a decrease in susceptibility to vancomycin, the difference in the vancomycin resistance level of the strain pair could be mainly attributed to the disruption of tcaA in the mutant.This study was conducted to identify resistance mechanisms that both strains might have in common. To this end we compared the transcriptomes of both strains with that of the closely related vancomycin susceptible MRSA/VSSA strain SA1450/94 (MIC: 2 mg/L). We found that the genes of the capsule biosynthesis were the only genes with higher expression in both VISA strains. Keywords: strain comparison
2013-03-12 | GSE10529 | GEO
Project description:Purpose: Staphylococcus aureus is a highly successful human pathogen responsible for wide range of infections. In this study, we provide insights into the virulence, pathogenicity, and antimicrobial resistance determinants of methicillin susceptible and methicillin resistant Staphylococcus aureus (MSSA; MRSA) recovered from non-healthcare environments. Experiment design: Three environmental MSSA and three environmental MRSA were selected for proteomic profiling using iTRAQ MS/MS. Gene Ontology (GO) Annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway Annotation were applied to interpret the functions of the proteins detected. Results: 792 proteins were identified in MSSA and MRSA. Comparative analysis of MRSA and MSSA revealed that 8 of out 792 proteins were up-regulated and 156 down-regulated. Differentially abundant proteins were predominantly involved in catalytic and binding activity. Among 164 proteins that had differences in abundance, 29 proteins were involved in pathogenesis, antimicrobial activities，stress response, mismatch repair and cell wall synthesis. Twenty-two proteins associated with pathogenicity, including spa, sbi, clfA and dlt were up-regulated in MRSA. Moreover, the up-regulated pathogenic protein entC2 in MSSA was determined to be a super antigen potentially capable of triggering toxic shock syndrome in the host. Conclusions: Enhanced pathogenicity, antimicrobial activity and stress response were observed in MRSA compared to MSSA.
2020-01-09 | PXD014478 | Pride