Genomic comparison of vancomycin susceptible and vancomycin intermediate Staphylococcus aureus pairs
Ontology highlight
ABSTRACT:
ORGANISM(S): Staphylococcus aureus
PROVIDER: GSE5047 | GEO | 2006/11/03
SECONDARY ACCESSION(S): PRJNA96683
REPOSITORIES: GEO
Similar Datasets
Project description:Complete reconstitution of the vancomycin-intermediate Staphylococcus aureus (VISA) phenotype of Mu50 was achieved by sequentially introducing mutations into five genes of a vancomycin-susceptible S. aureus (VSSA) strain ∆IP. Introduction of mutation Ser329Leu into vraS encoding the sensor histidine kinase of vraSR two-component regulatory (TCR) system and another mutation Glu146Lys into msrR, encoding putative methionine sulfoxide reductase regulator, raised vancomycin resistance to the level of heterogeneously vancomycin-intermediate S. aureus (hVISA) strain Mu3. Introduction of two more mutations, graR (Asn197Ser) of graSR TCR system and rpoB(His481Tyr) encoding ß subunit of RNA polymerase, converted the hVISA strain into a VISA strain having the level of vancomycin resistance of Mu50. Surprisingly, however, the constructed quadruple mutant strain did not have thickened cell wall, a cardinal feature of VISA phenotype. Subsequent study showed that cell-wall thickening was an inducible phenotype with the mutant strain as opposed to that of Mu50, which is a constitutive one. Finally, introduction of mutation Ala297Val into the orf SAV2309 of the mutant strain converted the inducible cell-wall thickening into a constitutive one. SAV2309 encodes a putative formate dehydrogenase (designated Fdh2). Though not a transcription regulator, the mutation of the fdh2 caused a significant change in transcriptome. Thus, all of the five mutated genes required for VISA phenotype acquisition were directly or indirectly involved in the regulation of cell physiology. VISA seemed to be achieved through multiple genetic events accompanying drastic changes in cell physiology.
2016-04-19 | GSE43643 | 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: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:Vancomycin-intermediate Staphylococcus aureus (VISA) evolve in a strain-specific manner and acquire mutations that lead to alterations in cell wall metabolism that reduce susceptibility to vancomycin. We had earlier isolated several VISA mutant strains of the clinical hVISA strain MM66. This study is aimed at analyzing the metabolome of these mutants in comparison to the parent strain.
2016-01-12 | ST000309 | MetabolomicsWorkbench
Project description:Treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections is dependant on the efficacy of last-line antibiotics like vancomycin. Vancomycin treatment failure is most commonly linked to the emergence of vancomycin-intermediate resistance in clincal isolates (termed VISA). These isolates have not acquired resistance genes but appear to accumulate a heterogenous collection of single nucleotide polymerisms that collectively alter the physiology of the cell to increase vancomycin tolerance. Cell wall thickening is common among VISA isolates and is thought to decrease vancomycin permeability. Changes in regulatory sRNA expression have been correlated with antibiotic stress responses in VISA isolates however the functions of the vast majority of these RNA regulators is unknown. Here we have used the endoribonuclease RNase III to capture RNA-RNA interactions using an RNA proximity-dependant ligation technique termed CLASH. RNase III-CLASH uncovered hundreds of sRNA-mRNA interactions in vivo allowing functional characterisation of many sRNAs for the first time. Surprisingly, we find that an mRNA encoding an unusually long 3’UTR (here termed vigR) functions as a regulatory ‘hub’ within our RNA-RNA interaction network. We demonstrate vigR promotes expression of the cell wall lytic transglycosylase encoded by isaA through a direct mRNA-mRNA interaction. Further, we find that the vigR mRNA 3’UTR is required for cell wall thickening and that deletion of the vigR 3’UTR re-sensitises VISA to vancomycin. Our results demonstrate the utility of RNase III-CLASH for identifying new regulatory RNA functions and indicate that S. aureus may use mRNA-mRNA interactions to co-ordinate gene expression much more widely than previously appreciated.
2021-09-14 | GSE158830 | GEO
Project description:Staphylococcus aureus is a notorious bacterial pathogen that causes a broad range of human diseases, and isolates that are resistant to several antibiotic classes including last resort antibiotics like vancomycin and daptomycin complicate the situation. We characterized S. aureus VC40, a strain that shows full resistance to vancomycin (MIC of 64 M-BM-5g/ml) and daptomycin (MIC of 4 M-BM-5g/ml) as well as a decreased susceptibility to further cell wall active agents. Genome sequencing revealed mutations in genes encoding the histidine kinases WalK and VraS that control cell envelope related processes and gene expression profiling indicated the induction of the respective regulons in strain VC40. Reconstitution of the mutations in walK or vraS into the susceptible S. aureus NCTC 8325 background resulted in a considerably increased resistance to vancomycin and daptomycin with MICs surpassing the clinical breakpoints for these antibiotics, thereby generating vancomycin-intermediate S. aureus (VISA) strains. As observed for S. aureus VC40, the walKwalk and vraS mutations also led to an increased expression of the respective regulons in the NCTC 8325 background. Phenotypic studies showed that S. aureus VC40 as well as the walKwalk and vraS mutants of strain NCTC 8325 were characterized by a significantly thickened cell wall, a decreased growth rate, a reduced autolytic activity and an increased resistance to lysostaphin-induced lysis. These results demonstrate that the WalK and VraS histidine kinases act as major switches which allow S. aureus to rapidly develop vancomycin resistance up to the VISA level via mutation of one single gene locus and concomitantly contribute to cross-resistance to other antibiotics including the last resort antibiotic daptomycin. Microarray was used to evaluate alteration in the transcriptome of mutS mutant and compared to the parental strain VC40
2014-08-18 | E-GEOD-46887 | biostudies-arrayexpress
Project description:Vancomycin Intermediate Staphylococcus aureus (VISA) strain originated during the prolonged hospitalization, chronic infection and vancomycin treatment. The hospital acquired D712 VISA strain were subjected to various sub-inhibitory concentration of nafcillin in Cation Adjusted Mueller Hinton Broth (CA-MHB) and Roswell Park Memorial Institute (RPMI) medium. The MIC of has dropped from 256 ug/ml to 1ug/ml in CA-MHB and RPMI media respectively. The cells were harvested and expression profiling were measured using RNA sequencing at time point of 03 hours.
2019-10-22 | GSE139141 | GEO
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:Staphylococcus aureus is a notorious bacterial pathogen that causes a broad range of human diseases, and isolates that are resistant to several antibiotic classes including last resort antibiotics like vancomycin and daptomycin complicate the situation. We characterized S. aureus VC40, a strain that shows full resistance to vancomycin (MIC of 64 µg/ml) and daptomycin (MIC of 4 µg/ml) as well as a decreased susceptibility to further cell wall active agents. Genome sequencing revealed mutations in genes encoding the histidine kinases WalK and VraS that control cell envelope related processes and gene expression profiling indicated the induction of the respective regulons in strain VC40. Reconstitution of the mutations in walK or vraS into the susceptible S. aureus NCTC 8325 background resulted in a considerably increased resistance to vancomycin and daptomycin with MICs surpassing the clinical breakpoints for these antibiotics, thereby generating vancomycin-intermediate S. aureus (VISA) strains. As observed for S. aureus VC40, the walKwalk and vraS mutations also led to an increased expression of the respective regulons in the NCTC 8325 background. Phenotypic studies showed that S. aureus VC40 as well as the walKwalk and vraS mutants of strain NCTC 8325 were characterized by a significantly thickened cell wall, a decreased growth rate, a reduced autolytic activity and an increased resistance to lysostaphin-induced lysis. These results demonstrate that the WalK and VraS histidine kinases act as major switches which allow S. aureus to rapidly develop vancomycin resistance up to the VISA level via mutation of one single gene locus and concomitantly contribute to cross-resistance to other antibiotics including the last resort antibiotic daptomycin.
2014-08-18 | GSE46887 | GEO
Project description:In this study, we detected the first lysine succinylome and acetylome in a vancomycin-intermediate S. aureus (VISA) strain, XN108.Furthermore,Comparative analysis of the protein succinylation and acetylation between XN108-ΔcobB and XN108-WT strain was conducted on the basis of quantitative detection of both protein expression and protein modification
2022-11-09 | PXD033341 | Pride