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| Status |
Public on Dec 02, 2014 |
| Title |
Prolonged growth of a clinical S. aureus strain selects for a stable SCV and Full genomic characterization of the development in a clinical Staphylococcus aureus strain of a stable Small Colony Variant cell-type |
| Organism |
Staphylococcus aureus |
| Experiment type |
Expression profiling by high throughput sequencing
Other
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| Summary |
We have observed that for a number of S. aureus strains as they switch to a SCV lifestyle there is the formation of an extracellular matrix. We focused our analysis on one strain, WCH-SK2. For bacterial survival in the host, the combination of low nutrients and the prolonged timeframe forms a stress that selects for a specific cell-type from the population. In this context, we used steady-state growth conditions with low nutrients and a controlled low growth rate, for a prolonged time and with methylglyoxal. These conditions induced S. aureus WCH-SK2 into a stable SCV cell-type, they did not revert after sub-culturing.
Methods: Transcriptomic profiles of wild-type (WT) and SCV were generated in continuous culture in the presence of stress (high and low level of methylglyoxal).
Results: Analysis revealed these cells possessed a metabolic and surface profile that was different from previously described SCVs or biofilm cells. The extracellular matrix was protein and extracellular DNA; but not polysaccharide. The SCV cells induced expression of certain surface proteins (such as Ebh) and lantibiotic synthesis while down-regulating factors that stimulates immune response (leucocidin, capsule, carotenoid). We also studied further their genetic characteristics. They possessed an increased viability in the presence of antibiotics compared to their non-SCV form. Their stability implied there had been genetic changes, we determined the whole genome sequence of WCH-SK2 and its stable SCV forms at a single base resolution, employing Single Molecular Real-Time (SMRT) sequencing that also enables the methylome to be determined. The genetic features of this isolate have been identified; the SCCmec type, the pathogenicity and genetic islands and virulence factors. The comparison has identified a set of genetic changes that occurred in the stable SCV form; most notably to the global regulator MgrA and the phosphoserine phosphatase RsbU (part of the regulatory pathway of the sigma factor SigB). There was a shift in the methylation across the genome.
Conclusions: Our data reveal a cell heterogeneity within a S. aureus population and using conditions that resemble long-term survival in the host has identified a previously unnoticed S. aureus cell-type, with a distinctive metabolic and molecular profile. The results from this study represent a unique identification of a suite of epigenetic, genetic and transcriptional factors that are implicated in the switch in S. aureus to its persistent SCV form
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| Overall design |
Total RNA of WT (batch culture) and SCV formed in high level of methylglyoxal (0.031%) at day 55 and SCV formed at low level of methylglyoxal (0.0078%) at day 30 of continuous culture. DNA genomic of WT and stable SCV formed in high level of methylglyoxal (0.031%)
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| Contributor(s) |
Bui LM, Kidd S |
| Citation(s) |
25385795 |
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| Submission date |
Dec 01, 2014 |
| Last update date |
May 15, 2019 |
| Contact name |
Long M.G Bui |
| E-mail(s) |
bmglongd99@gmail.com
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| Phone |
06183132610
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| Organization name |
University of Adelaide
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| Department |
Microbiology
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| Lab |
416
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| Street address |
North Terrace Campus
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| City |
Adelaide |
| State/province |
South Australia |
| ZIP/Postal code |
5005 |
| Country |
Australia |
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| Platforms (2) |
| GPL19476 |
Ion Torrent PGM (Staphylococcus aureus) |
| GPL20613 |
PacBio RS II (Staphylococcus aureus) |
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| Samples (5)
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| Relations |
| BioProject |
PRJNA268968 |
| SRA |
SRP050388 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE63750_DNA-seq_analysis_files.tar.gz |
3.6 Mb |
(ftp)(http) |
TAR |
| GSE63750_Final-Result-chemhigh-chemlow-batch-transcriptomes.xlsx |
148.1 Kb |
(ftp)(http) |
XLSX |
| GSE63750_SK2_batch_polished_assembly.fasta.gz |
874.3 Kb |
(ftp)(http) |
FASTA |
| GSE63750_SK2_chem_1contig-polished_assembly.fasta.gz |
871.2 Kb |
(ftp)(http) |
FASTA |
| GSE63750_chemhigh-batch-result-using-R-DeSeq.csv.gz |
201.8 Kb |
(ftp)(http) |
CSV |
| GSE63750_chemlow-batch-result-using-R-DeSeq.csv.gz |
201.7 Kb |
(ftp)(http) |
CSV |
| GSE63750_count-batch.txt.gz |
68.4 Kb |
(ftp)(http) |
TXT |
| GSE63750_count-chemhigh-batch.txt.gz |
49.6 Kb |
(ftp)(http) |
TXT |
| GSE63750_count-chemhigh.txt.gz |
195.3 Kb |
(ftp)(http) |
TXT |
| GSE63750_count-chemlow-batch.txt.gz |
50.0 Kb |
(ftp)(http) |
TXT |
| GSE63750_count-chemlow.txt.gz |
202.1 Kb |
(ftp)(http) |
TXT |
SRA Run Selector |
| Raw data are available in SRA |
| Processed data are available on Series record |
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