Wild-type and irr mutant Group A Streptococcus (GAS) strains
Ontology highlight
ABSTRACT:
ORGANISM(S): Streptococcus pyogenes Streptococcus pyogenes M1 GAS
PROVIDER: GSE1550 | GEO | 2004/07/14
SECONDARY ACCESSION(S): PRJNA89949
REPOSITORIES: GEO
Similar Datasets
Project description:GAS strains were grown in THY broth to early exponential phase and RNA extracted. cDNA was generated and the expression profiles were determined using the RMLgenechip. Comparisons between the sample groups allow the identification of genes differentially expressed between strains. This experiment compared pre- and post- mouse passaged GAS strains. Keywords: GAS comparison
2006-02-01 | GSE3899 | GEO
Project description:Wild-type and irr mutant Group A Streptococcus (GAS) strains
| PRJNA89949 | ENA
Project description:Streptococcus pyogenes (Group A Streptococcus; GAS) commonly causes pharyngitis in children and adults, with severe invasive disease and immune sequelae being an infrequent consequence. The ability of GAS to invade the host and establish infection likely involves subversion of host immune defenses. However, the signaling pathways and innate immune responses of epithelial cells to GAS are not well understood. In this study, we utilized RNAseq to characterize the inflammatory responses of primary human tonsil epithelial (TEpi) cells to infection with the laboratory-adapted M6 strain JRS4 and the M1T1 clinical isolate 5448. Both strains induced the expression of genes encoding a wide range of inflammatory mediators, including IL-8. Pathway analysis revealed differentially expressed genes between mock and JRS4 or 5448-infected TEpi cells, were enriched in transcription factor networks that regulate IL-8 expression, such as AP-1, ATF-2 and NFAT. While JRS4 infection resulted in high levels of secreted IL-8, 5448 infection did not, suggesting that 5448 may post-transcriptionally dampen IL-8 production. Infection with 5448ΔcepA, an isogenic mutant lacking the IL-8 protease SpyCEP, resulted in IL-8 secretion levels comparable to JRS4 infection. Complementation of 5448ΔcepA and JRS4 with a plasmid encoding 5448-derived SpyCEP significantly reduced IL-8 secretion by TEpi cells. Our results suggest that intracellular infection with the pathogenic GAS M1T1 clone induces a strong pro-inflammatory response in primary tonsil epithelial cells, but modulates this host response by selectively degrading the neutrophil-recruiting chemokine IL-8 to benefit infection.
2018-05-08 | GSE107001 | GEO
Project description:Rgg-dependent transcriptional regulation in Streptococcus pyogenes strains MGAS5005 and CS101 was analyzed during post-exponential phase of growth Keywords: strain comparion, post-exponential growth, rgg mutant
2008-02-01 | GSE7341 | GEO
Project description:Small regulatory RNAs (sRNAs) represent a major mechanism of virulence regulation in several pathogens. To date, only three sRNAs have been described in GAS in any detail. To identify whether sRNAs are common within the GAS genome, we created a custom Affymetrix tiling microarray in which all intergenic regions (>49 bp) of the MGAS2221 genome were tiled at high density. Triplicate cultures of strain MGAS2221 in THY broth were grown to the exponential phase (O.D.600 of 0.5) of growth and RNA was isolated, converted to cDNA, fragmented, labeled, and hybridized to our custom array (one array per RNA sample [ hence three arrays total]). Our data identified the presence of 40 candidate sRNAs within the MGAS2221 genome.
2009-08-25 | GSE17789 | GEO
Project description:Clonal emergence is a major driver for changes in bacterial disease epidemiology. Recently, it has been proposed that episodic emergence of novel, hypervirulent clones of group A Streptococcus (GAS) results from horizontal gene transfer (HGT) and recombination events leading to increased expression of the cytotoxins Nga (NADase) and SLO (streptolysin O). We previously described a gene fusion event involving the gene encoding the GAS M protein (emm) and an adjacent M-like protein (enn) in the emm4 GAS population, a GAS emm type that lacks the hyaluronic acid capsule. Using whole genome sequencing of a temporally and geographically diverse set of 1,127 isolates, we discovered that the North American emm4 GAS population has undergone clonal replacement with emergent GAS strains completely replacing historical isolates by 2017. Emergent emm4 GAS strains were defined by a handful of small genetic variations, including the emm-enn gene fusion, and showed a marked in vitro growth defect compared to historical strains. In contrast to other previously described GAS clonal emergence events, emergent emm4 GAS lacked significant HGT events and showed no significant increase in transcript levels of nga/slo toxin gene via RNA sequencing and quantitative real-time PCR analysis relative to historic strains. Despite the in vitro growth differences, emergent emm4 GAS strains demonstrated hypervirulence in mouse and ex vivo growth in human blood compared to historical strains. Thus, these data detail the emergence and dissemination of a hypervirulent acapsular GAS clone defined by small genetic variation thereby defining a novel model for GAS strain replacement.
2021-05-05 | GSE160737 | GEO
Project description:To determine differences in GC Tfh cells isolated from the tonsils of children who have undergone tonsillectomy for either recurrent Group A Streptococcus (GAS) tonsillitis (RT) or non-RT (sleep apnea). Grants: Thrasher Research Fund for an Early Career Award 12969 - Jennifer Dan UM1 AI100663 - Shane Crotty Clinical Research Fellowship Grant UK Charity No. 1089464 - David Layfield, Ramsey Cuttress, Christian Ottensmeier
2019-06-20 | GSE123977 | GEO
Project description:Small regulatory RNAs (sRNAs) represent a major mechanism of virulence regulation in several pathogens. To date, only three sRNAs have been described in GAS in any detail. To identify whether sRNAs are common within the GAS genome, we created a custom Affymetrix tiling microarray in which all intergenic regions (>49 bp) of the MGAS2221 genome were tiled at high density. Triplicate cultures of strain MGAS2221 in THY broth were grown to the exponential phase (O.D.600 of 0.5) of growth and RNA was isolated, converted to cDNA, fragmented, labeled, and hybridized to our custom array (one array per RNA sample [ hence three arrays total]). Our data identified the presence of 40 candidate sRNAs within the MGAS2221 genome. Three cultures of MGAS2221 were grown in THY broth to the exponential (O.D. 0.5) phase of growth. Two volumes of RNA protect were added to the samples, the samples incubated at room temperature for 5 minutes, and the bacteria collected through centrifugation. Total RNA was isolated via a mechanical disruption method, converted to cDNA, fragmented, labeled, and hybridized to our Affymetrix microarray. Data was analyzed using tiling analysis software to combine the data from the three arrays and generate signal intensities. The supplementary files 'GSE17789_2221sRNA_signal.bar' and 'GSE17789_2221sRNA_pvalue.bar' contain the signals and p-values, respectively, for Samples GSM444010-GSM444012. The BAR files are generated by TAS software using PM/MM signal intensities. Signal intensity data is reported in a linear scale; the p-value is reported in -10log10 scale. Probe analysis used a bandwidth of 40. Interval analysis used a threshold of 0, a maximum gap of 20, and a minimum run of 60.
2010-05-06 | E-GEOD-17789 | biostudies-arrayexpress
Project description:JRS4 is our wild-type M6 serotype GAS and JRS519 is our Mga- M6 serotype GAS. SF370 is our wild-type M1 serotype GAS and KSM165L is our Mga- M1 serotype GAS. Table 1: Genomic Normalization Description: Step by Step instructions for the removal of outlier background data and any ORF data that did not meet threshold of 2SD above background average, using original data from gpr file provided in each of the sample files. Table 2: M1 Mga+ vs Mga- Description: Step by Step instructions for the removal of outlier data as compared across all possible data points for each ORF. Data points after genomic normalization are used with resultant averages and standard deviations for each ORF computed. Table 3: M6 Mga+ vs Mga- Description: Step by Step instructions for the removal of outlier data as compared across all possible data points for each ORF. Data points after genomic normalization are used with resultant averages and standard deviations for each ORF computed. Keywords: repeat sample
2005-04-06 | GSE1895 | GEO
Project description:Rgg-dependent transcriptional regulation in Streptococcus pyogenes strains MGAS5005 and CS101 was analyzed during post-exponential phase of growth Keywords: strain comparion, post-exponential growth, rgg mutant Microarray analysis was performed using RNA samples isolated from wild-type MGAS5005 and CS101 strains as well as their rgg mutant strains during post-exponential phase of growth
2010-05-26 | E-GEOD-7341 | biostudies-arrayexpress