Microarray analysis for Streptococcus pyogenes M1-CdhA (-) mutant
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ABSTRACT:
ORGANISM(S): Streptococcus pyogenes
PROVIDER: GSE15546 | GEO | 2010/10/01
SECONDARY ACCESSION(S): PRJNA115983
REPOSITORIES: GEO
Similar Datasets
Project description:A total of 192 genes were found to be differentially expressed; 38 genes of them were up regulated and 154 genes were down regulated. Most notably the functional categories that were affected include carbohydrate metabolism and cell envelop realted genes ( 56, 29.1% of the total),Virulence genes (12 genes 6.25% of the total significantly differentiated genes), and aminoacid transport genes (7 genes, 3.6 %). Among the virulence-related genes, the most notable ones were those belong to the production of capsule, the M protein, exotoxin, NAD glycohydrolase and Streptolysin S. Some of the capsule related genes were down regulated by more than 64 fold. Additionally 11 differentially expressed lipid metabolism related genes and four aminoacid transport and metabolism-related genes were upregulated. These results indicate that the C-terminal CHAP domain of CdhA (group A Streptococcal Cell division controlling and Chain-forming cell wall hydrolase) plays an important role in the regulation of virulence. Since these mutant lack cell wall hydrolase activity but are not defective in cell division or growth, we believe that CdhA isa multifunctional protein with N-terminal region controlling cell division and c-terminal region responsible for regulating bacterial virulence.
2010-10-01 | GSE15598 | GEO
Project description:A total of 163 genes were found to be differentially expressed; 38 genes of them were up regulated and 125 genes were down regulated. Most notably the functional categories that were affected include Virulence genes (18 genes 11% of the total significantly differentiated genes), carbohydrate metabolism and cell envelop realted genes ( 31, 19.1% of the total), and aminoacid transport genes (21genes, 12.9%). Among the virulence-related genes, the most notable one were those belong to the production of capsule, the M protein, exotoxin, NAD glycohydrolase and Streptolysin S. Some of the capsule related genes were down regulated by more than 64 fold. These results indicate that CdhA (group A Streptococcal Cell division controlling and Chain-forming cell wall hydrolase) plays an important role in the regulation of virulence. S.pyogenes strain SF370 (wild-type) was procured from ATCC (ATCC 700294). M1-CdhA(-) mutant strain was obtained using pFW5 vector containing spectinomycin resistance marker (aad9). The mutant lacking CdhA is highly defective in cell division and growth, lacks antiphagocytic property and attenuated for virulence. Both strains (M1-Wild-type and M1-CdhA(-) were grown in Todd-Hewitt broth to their late log phase. Bacteria were harvested by centrifugation and washed twice with sterile PBS. Total RNA was isolated from these washed streptococci using Qiagen RNeasy Mini kit. For synthesis and labeling of cDNA, 20 ug of total RNA, 1.5 ug of random hexamer, 0.5mM dNTPs (except that 0.2mM of dTTP was replaced by the same amount of amino-allyl dUTP to incorporate dUTP into first-strand cDNA) were used in each reverse transcriptase reaction (Superscript II Reverse Transcriptase, Invitrogen). Purified cDNA preparations from the wild-type and M1CdhA(-) mutant strains were labeled with either Alexafluor-555 or Alexafluor-647 depending on the experimental design ( i.e. dye swap experiment). Differentially labeled probes were then combined and purified. Using three independently isolated RNA preparations (biological replicates), a total of 11 experiments (incorporating dye swaps) were performed. Accordingly eleven hybridization measurements for this mutant were performed. Thus Exp-1 to -4 (GSM388703, GSM388717, GSM388718 and GSM388719) are the technical replicates of the biological sample-1, Exp-5 to 8(GSM388732, GSM388733, GSM388734, and GSM388735) are technical replicates of biological sample-2 and Exp-9,-10, and -11 (GSM388736,GSM388737, and GSM388738) are technical replicates of the biological sample-3. Signals of the bound reagents on the microarray spots in terms of relative fluorescence values were measured and quantified by a laser scanner (GenePix 4100 ) at 10um/pixel resolution. The resulting images were processed using Gene Pix Pro software (version 4.0, Axon instruments). The raw data were obtained in the form of GenPix *.gpr output files. The web application CARMAweb (Comprehensive R based microarray analysis web service) was used for the normalization and analysis of microarray data. All raw data (in the form of *. GPR files) were uploaded to the web application in the data directory. Using appropriate navigation tree, background correction from the foreground signal was applied and within microarray normalization was achieved using the Lowess method. Genes flagged as bad spots by the scanning software were excluded from the analysis and all flagged spots were given a weight of zero. The normalized data were then subjected to fold-change analysis and t-statistics using Bioconductor multtest package. CARMAweb allows to set Log2 cut-off values for both the M (regulation) and the A (average expression) values. Differentially expressed genes (Log2 values of Mutant647-red vs. wild-type555-green or Log2 values Mutant-555(green) vs Wild-type 647-red) were defined based on cut-off value >1 Log2< i.e. all genes that show a two or more-fold up- or down-regulation. Bioconductors Multtest package provided suitable method to adjust P values according to multiple hypothesis testing problems.
2010-10-01 | E-GEOD-15546 | biostudies-arrayexpress
Project description:A total of 192 genes were found to be differentially expressed; 38 genes of them were up regulated and 154 genes were down regulated. Most notably the functional categories that were affected include carbohydrate metabolism and cell envelop realted genes ( 56, 29.1% of the total),Virulence genes (12 genes 6.25% of the total significantly differentiated genes), and aminoacid transport genes (7 genes, 3.6 %). Among the virulence-related genes, the most notable ones were those belong to the production of capsule, the M protein, exotoxin, NAD glycohydrolase and Streptolysin S. Some of the capsule related genes were down regulated by more than 64 fold. Additionally 11 differentially expressed lipid metabolism related genes and four aminoacid transport and metabolism-related genes were upregulated. These results indicate that the C-terminal CHAP domain of CdhA (group A Streptococcal Cell division controlling and Chain-forming cell wall hydrolase) plays an important role in the regulation of virulence. Since these mutant lack cell wall hydrolase activity but are not defective in cell division or growth, we believe that CdhA isa multifunctional protein with N-terminal region controlling cell division and c-terminal region responsible for regulating bacterial virulence. S. pyogenes strain SF370 (wild-type) was procured from ATCC (ATCC 700294). M1-CdhA55(-) mutant strain was obtained using pFW5 vector containing spectinomycin resistance marker (aad9). The mutant expressing truncated CdhA that lack C-terminal 55 residues constituting catalytic site of the CHAP domain is not defective in cell division and growth, but lacks antiphagocytic property and attenuated for virulence. Both strains (M1-Wild-type and M1-CdhA55(-) were grown in Todd-Hewitt broth to their late log phase. Bacteria were harvested by centrifugation and washed twice with sterile PBS. Total RNA was isolated from these washed streptococci using Qiagen RNeasy Mini kit. For synthesis and labeling of cDNA, 20 ug of total RNA, 1.5 ug of random hexamer, 0.5mM dNTPs (except that 0.2mM of dTTP was replaced by the same amount of amino-allyl dUTP to incorporate dUTP into first-strand cDNA) were used in each reverse transcriptase reaction (Superscript II Reverse Transcriptase, Invitrogen). Purified cDNA preparations from the wild-type and M1-CdhA55(-) mutant strains were labeled with either Alexafluor-555 or Alexafluor-647 depending on the experimental design ( i.e. dye swap experiment). Differentially labeled probes were then combined and purified. Using three independently isolated RNA preparations (biological replicates), a total of 7 experiments (incorporating dye swaps) were performed. Accordingly 7 hybridization measurements for this mutant were performed. Thus Exp-1 and 2 (GSM389993, GSM389994) are the technical replicates of the biological sample-1, Exp-3 and 4 (GSM389995, GSM390054) are technical replicates of biological sample-2 and Exp-5,-6, and -7 (GSM390055,GSM390056, and GSM390057) are technical replicates of the biological sample-3. Signals of the bound reagents on the microarray spots in terms of relative fluorescence values were measured and quantified by a laser scanner (GenePix 4100 ) at 10um/pixel resolution. The resulting images were processed using Gene Pix Pro software (version 4.0, Axon instruments). The raw data were obtained in the form of GenPix *.gpr output files. The web application CARMAweb (Comprehensive R based microarray analysis web service) was used for the normalization and analysis of microarray data. All raw data (in the form of *. GPR files) were uploaded to the web application in the data directory. Using appropriate navigation tree, background correction from the foreground signal was applied and within microarray normalization was achieved using the Lowess method. Genes flagged as bad spots by the scanning software were excluded from the analysis and all flagged spots were given a weight of zero. The normalized data were then subjected to fold-change analysis and t-statistics using Bioconductor multtest package. CARMAweb allows to set Log2 cut-off values for both the M (regulation) and the A (average expression) values. Differentially expressed genes (Log2 values of Mutant647-red vs. wild-type555-green or Log2 values Mutant-555(green) vs Wild-type 647-red) were defined based on cut-off value >1 Log2< i.e. all genes that show a two or more-fold up- or down-regulation. BioConductors Multtest package provided suitable method to adjust P values according to multiple hypothesis testing problems.
2010-10-01 | E-GEOD-15598 | biostudies-arrayexpress
Project description:Streptococcus dysgalactiae subsp. equeisimilis (SDSE) has Lancefield group G or C antigens. Recent epidemiological studies reveal that invasive SDSE infections have been increasing in Asia, Europe and US. Although SDSE possesses similar virulence factors to S. pyogenes including streptolysin S (SLS) and streptolysin O (SLO), some important S. pyogenes virulence factors including active superantigens, SpeB and a hyarulonic acids capsule are missing in SDSE genome. The mechanisms and the key virulence factors for causing invasive diseases by SDSE are poorly understood. Here, we analyzed the transcriptome of SDSE in vivo using the murine sepsis model, revealing the strategy of SDSE to destruct host tissues with the virulence factors and to scavenge depleted nutrients. The expression of SLO operon increased at relatively early stage of infection while the SLS and hyaluronidases upregulated after 4h post infection. Microarray data suggested that SDSE degraded host tissue polysaccharides by streptococcal-secreting poly/oligosaccharide lyases and simultaneously used the Entner-Doudoroff pathway to metabolize acquired carbohydrates. A global negative virulence gene regulator CsrRS of SDSE modulated the expressions of genes encoding SLS and the carbohydrate metabolism enzymes. Moreover, csrS deficient mutant induced sever systemic hemolysis in mice. The most frequently isolated stG6792 strains from invasive disease secreted abundant SLS and SLO rather than other SDSE emm types, indicating the relationship between the SLS and SLO productions and poor outcome by the stG6792 strain infection. Our findings suggest that the concomitant regulation of virulence factors destructing the host tissues and metabolic enzymes play an important role to produce invasive diseases by SDSE.
2013-09-09 | GSE43222 | GEO
Project description:Purpose: Key steps in understanding a biological process include identifying genes that are involved and determining how they are regulated. We developed a novel method for identifying TFs involved in a specific process and used it to map regulation of the key virulence factor of Cryptococcus neoformans, its capsule. Results: The map, built from expression profiles of 41 TF mutants, includes 20 TFs not previously known to regulate virulence attributes. It also reveals a hierarchy comprising executive, mid-level, and “foreman” TFs. When grouped by temporal expression pattern, these TFs explain much of the transcriptional dynamics of capsule induction. Phenotypic analysis of 41 TF deletion mutants revealed complex relationships among virulence factors and virulence in mice. Conclusions: These data resources and analyses provide the first integrated, systems level view of capsule regulation and biosynthesis. Our methods dramatically improve the efficiency with which transcriptional networks can be analyzed, making genomic approaches accessible to labs focused on specific physiological processes. A total of 288 expression profiles were generated by RNA-Seq analysis of Mutant and wildtype cells grown in capsule inducing conditions for 90 minutes. In addition, 3 replicate expression profiles were generated for wildtype cells grown in : a capsule non-inducing condition, a capsule inducing condition for 180 minutes, a capsule inducing condition for 480 minutes, and a capsule inducing condition for 1440 minutes. In addition, ChIP-seq of NRG1(CNAG_05222) in capsule inducing conditions, and USV101(CNAG_05420) in both capsule inducing and non-inducing conditions were generated.
2015-01-14 | E-GEOD-60398 | biostudies-arrayexpress
Project description:Streptococcus dysgalactiae subsp. equeisimilis (SDSE) has Lancefield group G or C antigens. Recent epidemiological studies reveal that invasive SDSE infections have been increasing in Asia, Europe and US. Although SDSE possesses similar virulence factors to S. pyogenes including streptolysin S (SLS) and streptolysin O (SLO), some important S. pyogenes virulence factors including active superantigens, SpeB and a hyarulonic acids capsule are missing in SDSE genome. The mechanisms and the key virulence factors for causing invasive diseases by SDSE are poorly understood. Here, we analyzed the transcriptome of SDSE in vivo using the murine sepsis model, revealing the strategy of SDSE to destruct host tissues with the virulence factors and to scavenge depleted nutrients. The expression of SLO operon increased at relatively early stage of infection while the SLS and hyaluronidases upregulated after 4h post infection. Microarray data suggested that SDSE degraded host tissue polysaccharides by streptococcal-secreting poly/oligosaccharide lyases and simultaneously used the Entner-Doudoroff pathway to metabolize acquired carbohydrates. A global negative virulence gene regulator CsrRS of SDSE modulated the expressions of genes encoding SLS and the carbohydrate metabolism enzymes. Moreover, csrS deficient mutant induced sever systemic hemolysis in mice. The most frequently isolated stG6792 strains from invasive disease secreted abundant SLS and SLO rather than other SDSE emm types, indicating the relationship between the SLS and SLO productions and poor outcome by the stG6792 strain infection. Our findings suggest that the concomitant regulation of virulence factors destructing the host tissues and metabolic enzymes play an important role to produce invasive diseases by SDSE. To analyze gene expressions in group G streptococci with the murine infection model, we developed a custom microarray for Streptococcus dysgalactiae subsp. equisimilis (SDSE) based on the genome sequences of three SDSE strains; GGS_124, ATCC12923 and RE378. We intraperitoneally inoculated 10^8 CFU of GGS_124 stain and the csrS deficient mutant into ddY mice. Bacterial cells were collected from the abdominal cavity at 0, 2, 4 and 8 h post infection. GGS_124 cells were also collected from OD600=0.6 culture in brain heart infusion broth as a control.
2013-09-09 | E-GEOD-43222 | biostudies-arrayexpress
Project description:identify binding sites of Gat201 in C. neoformans cells grown in DMEM at 37C in 5% CO2 The anti-phagocytic polysaccharide capsule of the yeast C. neoformans is a major virulence attribute. However, previous studies of the pleiotropic virulence determinant Gat201, a GATA-family transcription factor, suggested that capsule-independent antiphagocytic mechanisms exist. We have determined that Gat201 controls the mRNA levels of ~1100 genes (16% of the genome) and binds the upstream regions of ~130 genes. Seven Gat201-bound genes encode for putative and known transcription factors⎯including two previously implicated in virulence⎯suggesting an extensive regulatory network. Systematic analysis pinpointed two critical Gat201-bound genes, GAT204 (a transcription factor) and BLP1, which account for much of the capsule-independent antiphagocytic function of Gat201. A strong correlation was observed between the quantitative effects of single and double mutants on phagocytosis in vitro and on host colonization in vivo. This genetic dissection provides the first clear evidence that capsule-independent anti-phagocytic mechanisms are pivotal for successful mammalian infection by C. neoformans.
2011-07-15 | GSE27660 | GEO
Project description:Cryptococcus neoformans is a fungal pathogen responsible for hundreds of thousands of deaths per year. Its critical virulence factor is a polysacharride capsule which grows large upon entry into a mammalian host. We previously identified USV101 as a transcription factor whose deletion results in enlarged capsules. Here, we characterize strains lacking or overexpressing USV101 in terms of their virulence-related phenotypes, the altered course of infection by them and immune response to them in a mouse model, the relationship of Usv101 to other transcription factors involved in capsule regulation, and the changes in Usv101 activity during capsule induction. To study the function of Usv101, a key C. neoformans regulator of virulence, and its interactions with downstream capsule-regulating TFs GAT201 and SP1, expression profiles were generated by RNA-seq of a usv101 deletion mutant, a USV101 overexpression mutant, strains expressing GAT201 under various promoters, various double mutants, and wildtype cells grown in a capsule non-inducing condition, a capsule inducing condition for 90 minutes, or a capsule inducing condition for 24 hours.
2016-03-31 | E-GEOD-69532 | biostudies-arrayexpress
Project description:Purpose: Key steps in understanding a biological process include identifying genes that are involved and determining how they are regulated. We developed a novel method for identifying TFs involved in a specific process and used it to map regulation of the key virulence factor of Cryptococcus neoformans, its capsule. Results: The map, built from expression profiles of 41 TF mutants, includes 20 TFs not previously known to regulate virulence attributes. It also reveals a hierarchy comprising executive, mid-level, and “foreman” TFs. When grouped by temporal expression pattern, these TFs explain much of the transcriptional dynamics of capsule induction. Phenotypic analysis of 41 TF deletion mutants revealed complex relationships among virulence factors and virulence in mice. Conclusions: These data resources and analyses provide the first integrated, systems level view of capsule regulation and biosynthesis. Our methods dramatically improve the efficiency with which transcriptional networks can be analyzed, making genomic approaches accessible to labs focused on specific physiological processes.
2015-01-14 | GSE60398 | GEO
Project description:Pasteurella multocida is a Gram-negative capsulated bacterium responsible for a range of diseases that cause severe morbidity and mortality in livestock animals. The hyaluronic acid (HA) capsule produced by P. multocida serogroup A strains is a critical virulence factor. In this study, we utilised transposon-directed insertion site sequencing (TraDIS) to identify genes essential for in vitro growth of P. multocida, and combined TraDIS with discontinuous density gradients (TraDISort) to identify genes required for HA capsule production and regulation in this pathogen. Analysis of mutants with a high cell density phenotype, indicative of the loss of extracellular capsule, led to the identification of 69 genes important for capsule production. These genes included all previously characterized genes in the capsule biosynthesis locus, and fis and hfq that encode known positive regulators of P. multocida capsule. Many of the other capsule-associated genes identified in this study were involved in regulation or activation of the stringent response, including spoT and relA that encode proteins that regulate the concentration of guanosine alarmones. Disruption of the autoregulatory domains in the C-terminal half of SpoT using insertional mutagenesis resulted in reduced expression of capsule biosynthesis genes and an acapsular phenotype. Overall, these findings have greatly increased the understanding of hyaluronic acid capsule production and regulation in P. multocida.
2022-03-14 | GSE198087 | GEO