Characterizing the transcriptional adaptation of Staphylococcus aureus to stationary phase growth
Ontology highlight
ABSTRACT:
ORGANISM(S): Staphylococcus aureus
PROVIDER: GSE77242 | GEO | 2016/05/18
SECONDARY ACCESSION(S): PRJNA309838
REPOSITORIES: GEO
Similar Datasets
Project description:Staphylococcus aureus is an important human pathogen that causes life-threatening infections, and is resistant to the majority of our antibiotic arsenal. This resistance is complicated by the observation that most antibacterial agents target actively growing cells, thus, proving ineffective against slow growing populations, such as cells within a biofilm or in stationary phase. Recently, our group generated updated genome annotation files for S. aureus that not only include protein-coding genes but also regulatory and small RNAs. As such, these annotation files were used to perform a transcriptomic analysis in order to understand the metabolic and physiological changes that occur during transition from active growth to stationary phase; with a focus on sRNAs. We observed â¼24% of protein-coding and 34% of sRNA genes displaying changes in expression by â¥3-fold. Collectively, this study adds to our understanding of S. aureus adaptation to nutrient-limiting conditions, and sheds new light onto the contribution of sRNAs to this process. Bacterial cells were grown in TSB medium at 37°C with shaking for 3h (exponential growth phase) or 16h (stationary growth phase).
2016-05-18 | E-GEOD-77242 | biostudies-arrayexpress
Project description:In Staphylococcus aureus, hundreds of small regulatory or small RNAs (sRNAs) have been identified, yet this class of molecule remains poorly understood and severely understudied. sRNA genes are typically absent from genome annotation files, and as a consequence, their existence is often overlooked, particularly in global transcriptomic studies. To facilitate improved detection and analysis of sRNAs in S. aureus, we generated updated GenBank files for three commonly used S. aureus strains (MRSA252, NCTC 8325, and USA300), in which we added annotations for >260 previously identified sRNAs. These files, the first to include genome-wide annotation of sRNAs in S. aureus, were then used as a foundation to identify novel sRNAs in the community-associated methicillin-resistant strain USA300. This analysis led to the discovery of 39 previously unidentified sRNAs. Investigating the genomic loci of the newly identified sRNAs revealed a surprising degree of inconsistency in genome anno- tation in S. aureus, which may be hindering the analysis and functional exploration of these elements. Finally, using our newly created annotation files as a reference, we perform a global analysis of sRNA gene expression in S. aureus and demonstrate that the newly identified tsr25 is the most highly upregulated sRNA in human serum. This study provides an invaluable resource to the S. aureus research community in the form of our newly generated annotation files, while at the same time presenting the first examination of differential sRNA expression in pathophysiologically relevant conditions.
2016-01-05 | GSE74936 | GEO
Project description:In Staphylococcus aureus, hundreds of small regulatory or small RNAs (sRNAs) have been identified, yet this class of molecule remains poorly understood and severely understudied. sRNA genes are typically absent from genome annotation files, and as a consequence, their existence is often overlooked, particularly in global transcriptomic studies. To facilitate improved detection and analysis of sRNAs in S. aureus, we generated updated GenBank files for three commonly used S. aureus strains (MRSA252, NCTC 8325, and USA300), in which we added annotations for >260 previously identified sRNAs. These files, the first to include genome-wide annotation of sRNAs in S. aureus, were then used as a foundation to identify novel sRNAs in the community-associated methicillin-resistant strain USA300. This analysis led to the discovery of 39 previously unidentified sRNAs. Investigating the genomic loci of the newly identified sRNAs revealed a surprising degree of inconsistency in genome anno- tation in S. aureus, which may be hindering the analysis and functional exploration of these elements. Finally, using our newly created annotation files as a reference, we perform a global analysis of sRNA gene expression in S. aureus and demonstrate that the newly identified tsr25 is the most highly upregulated sRNA in human serum. This study provides an invaluable resource to the S. aureus research community in the form of our newly generated annotation files, while at the same time presenting the first examination of differential sRNA expression in pathophysiologically relevant conditions. Four RNAseq data sets in total. Each sample was generated by pooling three independent biological replicate RNA preps
2016-01-05 | E-GEOD-74936 | biostudies-arrayexpress
Project description:Next-generation sequencing technologies have dramatically increased the rate at which new genomes are sequenced. Accordingly, automated-annotation programs have become adept at identifying and annotating protein coding regions, as well as common and conserved RNAs. Additionally, RNAseq techniques have advanced our ability to identify and annotate regulatory RNAs (sRNAs), which remain significantly understudied. Recently, our group catalogued and annotated all previously known and newly identified sRNAs in several Staphylococcus aureus strains. These complete annotation files now serve as tools to compare the sRNA content of S. aureus to other bacterial strains to investigate the conservation of their sRNomes. Accordingly, in this study we performed RNAseq on two staphylococcal species, S. epidermidis and S. carnosus, identifying 118 and 89 sRNAs in these organisms, respectively. The sRNA content of all three species were then compared to elucidate their common and species-specific sRNA content, identifying a core set between 53 and 36 sRNAs encoded in each organism. In addition, we determined that S. aureus has the largest set of unique sRNAs (137) while S. epidermidis has the fewest (25). Finally, we identify a highly conserved sequence and structural motif differentially represented within, yet common to, both S. aureus and S. epidermidis. Collectively, in this study, we uncover the sRNome common to three staphylococcal species, shedding light on sRNAs that are likely to be involved in basic physiological processes common to the genus. More significantly, we have identified species-specific sRNAs that are likely to influence the individual lifestyle and behavior of these diverse staphylococcal strains.
2016-04-25 | GSE77567 | GEO
Project description:The genome sequence is the “blue-print of life”, but proteomics is required to relate this blue-print of life to the actual physiology of living cells. Because of their low complexity – only about 2.000 proteins make a Staphylococcus aureus cell viable – bacteria are excellent model systems to identify the entire protein assembly of a living organism. Many of the studies on physiological proteomics of bacteria, however, still rely on 2D gel-based technologies that visualize only a minor part of the proteome. In this study it will be shown that the majority of proteins expressed in the Gram-positive human pathogen S. aureus can be identified and even quantified by a combination of gel-based and gel-free approaches, the latter having undergone formidable improvements over the last 10 years. S. aureus has been the model of choice for our proteomic studies, because it combines high pathogenicity with increasing antibiotic resistance, which calls for new leads in the development of anti-staphylococcal therapy. On the way towards the entire proteome of S. aureus, we analysed four subproteomic fractions: cytosolic proteins, membrane-bound proteins, cell-surface associated and extracellular proteins, the two latter fractions containing most of the virulence factors. To obtain quantitative results, we compared growing cells and non-growing/stationary phase cells using the 15N metabolic labelling approach. With almost 2.000 proteins, 80 % of the expressed proteome was identified and even quantified in growing and non-growing cells. A comprehensive inventory of the entire protein assembly during the two physiologically distinct states is presented, which integrates data ranging from gene expression to subcellular localization. Three major protein classes were distinguished: (i) Proteins induced in the stationary phase only (ii) Vegetative proteins, no longer synthesized but stable in the stationary phase (iii) Vegetative proteins, no longer required in non-growing cells and finally degraded. This quantitative proteomics approach for growing/non-growing cells, which represents a proof-of-principle for whole-cell physiological proteomics, can now be extended to address particular infection-relevant physiological states. Importantly, the present model study represents the highest coverage of a bacterial proteome so far (except low complexity bacteria). It thus paves the way towards a new understanding of cell physiology and pathophysiology of S. aureus and related pathogenic bacteria, opening a new era in infection-related research on this crucial pathogen.
2009-11-12 | GSE15060 | GEO
Project description:The virulon of Staphyloccocus aureus is controlled by intricate connections between transcriptional and post-transcriptional regulators including proteins and small non coding RNAs (sRNAs). Most of the sRNAs regulate gene expression through base-pairings with mRNAs. Here, we have determined the transcriptome of RsaI sRNA of S. aureus.
2018-11-02 | GSE122064 | GEO
Project description:The genome sequence is the “blue-print of life”, but proteomics is required to relate this blue-print of life to the actual physiology of living cells. Because of their low complexity – only about 2.000 proteins make a Staphylococcus aureus cell viable – bacteria are excellent model systems to identify the entire protein assembly of a living organism. Many of the studies on physiological proteomics of bacteria, however, still rely on 2D gel-based technologies that visualize only a minor part of the proteome. In this study it will be shown that the majority of proteins expressed in the Gram-positive human pathogen S. aureus can be identified and even quantified by a combination of gel-based and gel-free approaches, the latter having undergone formidable improvements over the last 10 years. S. aureus has been the model of choice for our proteomic studies, because it combines high pathogenicity with increasing antibiotic resistance, which calls for new leads in the development of anti-staphylococcal therapy. On the way towards the entire proteome of S. aureus, we analysed four subproteomic fractions: cytosolic proteins, membrane-bound proteins, cell-surface associated and extracellular proteins, the two latter fractions containing most of the virulence factors. To obtain quantitative results, we compared growing cells and non-growing/stationary phase cells using the 15N metabolic labelling approach. With almost 2.000 proteins, 80 % of the expressed proteome was identified and even quantified in growing and non-growing cells. A comprehensive inventory of the entire protein assembly during the two physiologically distinct states is presented, which integrates data ranging from gene expression to subcellular localization. Three major protein classes were distinguished: (i) Proteins induced in the stationary phase only (ii) Vegetative proteins, no longer synthesized but stable in the stationary phase (iii) Vegetative proteins, no longer required in non-growing cells and finally degraded. This quantitative proteomics approach for growing/non-growing cells, which represents a proof-of-principle for whole-cell physiological proteomics, can now be extended to address particular infection-relevant physiological states. Importantly, the present model study represents the highest coverage of a bacterial proteome so far (except low complexity bacteria). It thus paves the way towards a new understanding of cell physiology and pathophysiology of S. aureus and related pathogenic bacteria, opening a new era in infection-related research on this crucial pathogen. For the DNA-microarray experiment RNA was extracted from two independently grown cultures. One was grown in 14N labelled BioExpress medium and the other in 15N labelled BioExpress medium. Samples of exponentially growing cells (OD600=0.5) and of cell at 5h after entry into stationary phase were harvested from every culture. Equal amounts of all four RNAs were pooled and the pool was used as common reference (Cy3-labeld) for the four sample RNAs (Cy3). Thus, in total four hybridizations, one for each sample versus the common reference, were performed.
2009-11-11 | E-GEOD-15060 | biostudies-arrayexpress
Project description:The virulon of Staphyloccocus aureus is controlled by intricate connections between transcriptional and post-transcriptional regulators including proteins and small non coding RNAs (sRNAs). Most of the sRNAs regulate gene expression through base-pairings with mRNAs. Here, we have applied and adapted the MS2-affinity purification approach coupled to RNA sequencing (MAPS) to determine the targetome of RsaI sRNA of S. aureus.
2018-11-02 | GSE122065 | GEO
Project description:Coordinated protein-coding sequence transcriptional responses of Staphylococcus aureus to antimicrobial exposure are well described but little is known of the role of bacterial non-coding, small RNAs (sRNAs) in these responses. Here we used RNAseq to investigate the sRNA response of the epidemic multiresistant hospital ST239 S. Aureus strain JKD6009 and its vancomycin-intermediate clinical derivative, JKD6008, after exposure to four antibiotics representing the major classes of antimicrobials used to treat methicillin-resistant S. Aureus infections. These agents included vancomycin, linezolid, ceftobiprole, and tigecycline. We identified 410 potential sRNAs (sRNAs) and then compared global sRNA and mRNA expression profiles at 2 and 6 hours, without antibiotic exposure, and after exposure to 0.5 x MIC for each antibiotic, for both JKD6009 (VSSA), and JKD6008 (VISA).
2013-06-10 | GSE40864 | GEO
Project description:Accurate annotation of regulatory RNAs is a complex task but nevertheless essential as sRNA molecular and functional studies ensue from it. Several formerly considered small RNAs (sRNA) are now known to be parts of UTR transcripts. In light of experimental data, we review hundreds of Staphylococcus aureus putative regulatory RNAs. We pinpoint those that are likely acting in trans and are not expressed from the opposite strand of a coding gene. We conclude that HG003, a NCTC8325 derivative strain, has about 50 bona fide sRNAs, indicating that these RNAs are less numerous than commonly stated.
2018-03-07 | GSE104971 | GEO