Transcription profiling of teicoplanin-susceptible strain of S.aureus and its teicoplanin-resistant derivative
Ontology highlight
ABSTRACT:
INSTRUMENT(S): G2565AA DNA microarray scanner [Agilent]
ORGANISM(S): Staphylococcus aureus
SUBMITTER: Yvan Charbonnier
PROVIDER: E-MEXP-738 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Publications
Transcriptomic and functional analysis of an autolysis-deficient, teicoplanin-resistant derivative of methicillin-resistant Staphylococcus aureus.
Renzoni Adriana A Barras Christine C François Patrice P Charbonnier Yvan Y Huggler Elzbieta E Garzoni Christian C Kelley William L WL Majcherczyk Paul P Schrenzel Jacques J Lew Daniel P DP Vaudaux Pierre P
Antimicrobial agents and chemotherapy 20060901 9
The molecular basis of glycopeptide-intermediate S. aureus (GISA) isolates is not well defined though frequently involves phenotypes such as thickened cell walls and decreased autolysis. We have exploited an isogenic pair of teicoplanin-susceptible (strain MRGR3) and teicoplanin-resistant (strain 14-4) methicillin-resistant S. aureus strains for detailed transcriptomic profiling and analysis of altered autolytic properties. Strain 14-4 displayed markedly deficient Triton X-100-triggered autolysi ...[more]
Similar Datasets
Project description:Background: Staphylococcus epidermidis (SE) has emerged as one of the most important causes of nosocomial infections. The SaeRS two-component signal transduction system (TCS) influences virulence and biofilm formation in Staphylococcus aureus. The deletion of saeR in S. epidermidis results in impaired anaerobic growth and decreased nitrate utilization. However, the regulatory function of SaeRS on biofilm formation and autolysis in S. epidermidis remains unclear. Results: The saeRS genes of SE1457 were deleted by homologous recombination. The saeRS deletion mutant, SE1457DsaeRS, exhibited increased biofilm formation that was disturbed more severely (a 4-fold reduction) by DNase I treatment compared to SE1457 and the complementation strain SE1457saec. Compared to SE1457 and SE1457saec, SE1457DsaeRS showed increased Triton X-100-induced autolysis (approximately 3-fold) and decreased cell viability in planktonic/biofilm states; further, SE1457DsaeRS also released more extracellular DNA (eDNA) in the biofilms. Correlated with the increased autolysis phenotype, the transcription of autolysis-related genes, such as atlE and aae, was increased in SE1457DsaeRS. Whereas the expression of accumulation-associated protein was up-regulated by 1.8-fold in 1457DsaeRS, the expression of an N-acetylglucosaminyl transferase enzyme (encoded by icaA) critical for polysaccharide intercellular adhesion (PIA) synthesis was not affected by the deletion of saeRS. Conclusions: Deletion of saeRS in S. epidermidis resulted in an increase in biofilm-forming ability, which was associated with increased eDNA release and up-regulated Aap expression. The increased eDNA release from SE1457DsaeRS was associated with increased bacterial autolysis and decreased bacterial cell viability in the planktonic/biofilm states. Comparision between SE1457 wild type strain and SA1457 SaeRS mutant strain after 4 hours and 12 hours of growth
2012-01-12 | E-GEOD-29309 | biostudies-arrayexpress
Project description:Objectives: Development of daptomycin resistance (DAPR) in Staphylococcus aureus is associated with clinical treatment failures. Mechanism(s) of such resistance has not been clearly defined. Methods: We studied an isogenic daptomycin-susceptible (DAPS) and daptomycin-resistant (DAPR) S. aureus strain pair (616; 701) from a patient with relapsing endocarditis during daptomycin treatment, using comparative transcriptomic and proteomic techniques. Results. Minor differences in genome content were found between strains by DNA hybridization. Transcriptomic analyses identified a number of genes differentially expressed in important functional categories: cell division, metabolism of bacterial envelopes and global regulation. Of note, the DAPR isolate exhibited reduced expression of the major cell wall autolysis gene coincident with upregulation of genes involved in wall teichoic acid production. Using quantitative (q)RT-PCR on gene cadre putatively involved in cationic peptide resistance, we formulated a putative regulatory network compatible with microarray data-sets, mainly implicating bacterial envelopes. Of interest, qRT-PCR of this same gene cadre from two distinct isogenic DAPS/DAPR clinical strain pairs revealed evidence of other strain dependent networks operative in the DAPR phenotype. Comparative proteomics of 616 vs 701 revealed differential abundance of proteins in various functional categories including: cell-wall associated targets and biofilm-formation proteins. Phenotypically, strains 616 and 701 showed major differences in ability to develop bacterial biofilms in presence of the antibacterial lipid, oleic acid. Conclusions: Compatible with previous in vitro observations, in vivo acquired DAPR in S. aureus is a complex, multistep phenomenon allowing for: i) strain dependent phenotypes; ii) transcriptome adaptation; and iii) modification of lipid and protein content of cellular envelopes. Daptomycin suceptible strain vs daptomycin non suceptible strain after daptomycin treatment
2011-12-02 | E-GEOD-28632 | biostudies-arrayexpress
Project description:In this study we mutated the ecsAB operon in two different Staphylococcus aureus strains, Newman and LS-1, and performed a wide characterization of phenotypic effects of the mutations. A growth defect, increased autolysis and lysostaphin sensitivity, decreased levels of cell wall proteins and altered cell surface texture indicate that Ecs deficiency causes significant changes in the cell wall. The precursor form of staphylokinase was released into the wall in an Ecs-dependent manner. Pathogenicity of the ecs mutants was studied with a mouse arthritis model. Mice inoculated with ecs mutants developed markedly milder infections than when inoculated with the wild-type strains, as was illustrated by a lower mortality, less weight loss, decreased persistence of staphylococci in the kidneys and a milder arthritis. DNA microarray analysis revealed that inactivation of Ecs in S. aureus Newman caused either up-regulation or down-regulation of genes encoding various membrane transport proteins, particularly ABC transporters and phosphate-specific transport (PST) systems. Differentially expressed were also several genes encoding proteins involved in virulence, including the virulence factor regulator protein Rot, protein A, adhesins and capsular polysaccharide biosynthesis proteins. Furthermore, the susceptibility of ecs mutant to ribosomal antibiotics as well as the chelerythrine and sanguinarine plant alkaloids was increased. WT and ecsA mutant strains were hybridized at 3 and 6 hours of growth in rich medium (4-replicates)
2011-01-01 | E-GEOD-22353 | biostudies-arrayexpress
Project description:Gene expression studies are used to help identify disease-associated genes, by comparing the levels of expressed transcripts between cases and controls, and to identify functional genetic variants known as expression quantitative loci (eQTLs). While many of these studies are performed in blood or lymphoblastoid cell lines due to tissue accessibility, the relevance of expression differences in tissues that are not the primary site of disease is unclear. Further, many eQTLs are tissue specific. Thus, there is a clear and compelling need to conduct gene expression studies in tissues that are specifically relevant to the disease of interest. One major technical concern about using autopsy-derived tissue is how representative it is of physiologic conditions, given the effect of postmortem interval on tissue degradation. In this study, we monitored the gene expression of 13 tissue samples harvested from a rapid autopsy heart (non-failed heart) and 7 from a cardiac explant (failed heart) through 24 hours of autolysis. The 24 hour autopsy simulation design reflects a typical autopsy scenario where a body may begin cooling to ambient temperature for ~12 hours, before transportation and storage in a refrigerated room in a morgue. In addition, we also simulated a scenario wherein the body was left at room temperature for up to 24 hours before being found. RNA from the 20 samples and triplicate from the HeLa cell line were run on the Affymetrix Exon arrays according to the manufacturer's protocol. The expression profiles of 7 cardiac tissue samples from the cardiac transplant operation (explant/failed heart) and 13 from a rapid-autopsy program (autopsy/non-failed heart) were harvested under the cold- and warm-24 hour autolysis conditions. The 7 explant samples include - 2 biological replicates at 0 hr, 1 at 6 hrs, 1 at 12 hrs, 2 biological replicates at 18 hr cold-autolysis condition and 1 at 18 hr warm-autolysis condition. The 13 autopsy samples include - 3 biological replicates at 0 hr (2 from the left and 1 from the right ventricle), 1 at 6 hrs, 2 biological replicates at 12 hrs (1 from the left and 1 from the right ventricle), 3 biological replicates at 18 hr cold-autolysis condition (2 from the left and 1 from the right ventricle), 2 biological replicates at 18 hr warm-autolysis condition ( 1 from the left and 1 from the right ventricle), 1 at 24 hr cold-autolysis condition and 1 at 24 hr warm-autolysis condition. Gene expression profiles of triplicate liver and heart exon array data obtained from Affymetrix were also used as reference .
2011-09-30 | E-GEOD-32519 | biostudies-arrayexpress
Project description:Mutants from SG511 and NCTC8325 (wild type isolates) resistant to daptomycin were obtained following serial passage experiments in vitro. Transcriptomic experiments showed alteration in the expression of genes involved in various pathways including general metabolism, cell wall regulon and lipid metabolism. Microarray was used to evaluate alteration in the transcriptome between wild type strains SG511 and NCTC8325 and their daptomycin resistant isolates, in antibiotic-free medium.
2015-11-01 | E-GEOD-50842 | biostudies-arrayexpress
Project description:Overnight cultures of wild type COL or the bshA mutant were back-diluted to an O.D.650 of 0.1 in 30 mL of TSB. The cells were grown at 37C with shaking in a 300mL flask until they reached an O.D.650 of 1.1. The cells were then equally separated into 50mL Falcon tubes, so that each tube had 10mL of culture. One tube for each strain was induced with 1 mM diamide and one with 10 mM H2O2, which we did not send for analysis. All cultures were allowed to continue growing at 37C with shaking for another 20 minutes. RNA extractions were carried out as previously described in Tamber et al., Infect Imunn, 2010. Microarray was used to evaluate alteration in the transcriptome of COL and its bshA mutant strain in the presence/absence of bacillithiol
2013-11-12 | E-GEOD-46885 | biostudies-arrayexpress
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:Isoquinolines (IQs) are natural substances with antibiotic potential. IQ-238 is a synthetic analog of the novel-type N,C-coupled naphtylisoquinoline (NIQ) alkaloid ancisheynine. Gene expression data, cytotoxicity measurements and metabolic modelling is combined to assess the effects of the N,C-coupled naphtylisoquinoline (NIQ) compound IQ-238 on Staphylococcus aureus and man as a potential lead for novel antibiotics. It possesses a high activity against staphylococci but has low cytotoxicity in human cell lines. Genome annotation identified missed enzymes (validated by PCR) in the primary (e.g. nucleotide) metabolism of staphylococci. Gene expression changed after cultivation with IQ-238. Metabolic modelling did yield the adaptations of all central enzymes, including those not affected by significant gene expression changes. The data show that IQ-238 interferes with the carbohydrate metabolism in staphylococci. The data suggest that IQ-238 is a promising lead for antibiotic therapy against S. aureus infections. HG001 WT strain exposed to GB-AP-238 in rich medium
2015-04-30 | E-GEOD-33832 | biostudies-arrayexpress
Project description:Transcriptional profiling of mutants with beneficial in-frame null mutations. The goal of the study is to understand how expression of the mutants and their parental strain differs in conditions where the mutations are beneficial. For each of two conditions (media with either glutamine or alanine as the sole carbon source) four mutants were compared with the parental strain. Two biological replicates were done for each comparison. A total of 16 arrays were used.
2013-08-23 | E-GEOD-30345 | biostudies-arrayexpress
Project description:Biofilm formation is considered the most important factor involved in pathogenicity of Staphylococcus epidermidis.We investigated the role of two-component signal transduction system (TCS) srrAB, which was up-regulated under micro-aerobic condition, in the growth and biofilm formation of S. epidermidis.AsrrA-deficient mutant (M-bM-^HM-^FsrrA) derived from S. epidermidis1457 (SE1457), exhibited dramatic reduction in growth and biofilm formation underboth aerobic and micro-aerobic conditions, and more sensitive to several different types of antimicrobial agents, H2O2 and SDS. In New Zealand Rabbit model of S. epidermidis biofilm infection, M-bM-^HM-^FsrrA hardly formed biofilm compared to that of SE1457. Phenotypic alteration was restored to the wide-type levelwhen srrAB were complemented into M-bM-^HM-^FsrrA. Further study found that the initial adherence capacity and production of polysaccharide intercellular adhesion (PIA) in M-bM-^HM-^FsrrA were decreased, while extracellular DNA (eDNA) was increased. Transcriptional Analysisby qRT-PCR demonstrated that expression level of icaRin M-bM-^HM-^FsrrA was up-regulated compared to that of SE1457 under aerobic condition, while down-regulated under micro-aerobic condition;icaA and altE were down-regulated under both conditions. Expression of genes involved in respiratory metabolism, such as qoxB(quinol oxidase polypeptide II), ctaA(heme A synthase), and pfl(pyruvate formatelyase), etc. were down-regulated in M-bM-^HM-^FsrrAunder both conditions. Electrophoretic mobility shift assay (EMSA) revealed that phosphorylated SrrA bound to the promoter regions of icaR, icaA, atlE, qoxB,ctaA, andpflB just like binding its own promoter region srr. Taken together, our results demonstrate that srrAB may provide a mechanistic link between respiratory metabolism, environmental signals, and regulation of biofilm formation in S. epidermidis. Microarrays covering different S. epidermidis genomes were used to assess the impact of the two component system srrAB on growth and biofilm formation, by comparing WT with srrA mutant transcriptomes
2014-11-21 | E-GEOD-47101 | biostudies-arrayexpress