Project description:Streptococcus suis is an important zoonotic pathogen that can cause meningitis and sepsis in both pigs and humans. In this study,we evaluated the genetic difference of 40 Streptococcus suis strains belonging to various sequence types by comparative genomic hybridization to identify genes associated with the variation in pathogenicity using NimbleGen’s tilling microarray platform. Application of Comparative Phylogenomics to Identify Genetic Differences Relating to Pathogenicity of Streptococcus suis
Project description:Streptococcus suis is an important emerging worldwide pig pathogen and zoonotic agent with rapid evolution of virulence and drug resistance. Licochalcone A, used in traditional Chinese medicine, exhibits antimicrobial, antioxidant and anti-inflammatory activities. Herein, a whole-genome DNA microarray was used to investigate the global transcriptional regulation of Streptococcus suis 05ZYH33 treated by subinhibitory concentration of licochalcone A. 132 genes were differentially regulated upon liochalcone A treatment, including 78 genes up-regulated and 54 genes down-regulated which included many central biological functions such as metabolism, transcription and translation. We tried to investigate the antimicrobial mechanism of licochalcone A in the aspect of bacterial cell cycle control. Our analysis indicated that licochalcone A might inhibit the growth of S. suis by controlling the replication initiation and cell division through amino acid metabolism. A cDNA microarray imprinted with 2156 genes representing about 98% of Streptococcus suis serotype 2 genome was used for transcriptome analysis. For two-sample (reference vs. test) microarray hybridization, four independent bacterial cultures from each condition were prepared as biological replicates for RNA isolation. Four dual-fluorescence-labeled cDNA probes were prepared to hybridize with four slides, respectively. Pairwise comparisons were made using dye swaps to avoid labeling bias. A ratio of mRNA levels (test/reference) was calculated for each gene. Significant changes of gene expression were identified with the SAM software. After the SAM analysis, only genes with at least 2-fold changes in expression were collected for further analysis.
Project description:To investigate the effect of CodY mutation on the gene expression in Streptococcus suis serotype 2 SC19 strain, we have employed whole genome microarray expression profiling as a discovery platform to identify genes regulated by CodY mutation. DNA microarray analysis was performed using an Agilent custom-designed oligonucleotide microarray. Based upon the whole genome sequence of SC19 , specific 60-mer oligonucleotide probes were designed using eArray (https://earray.chem.agilent.com/earray/), to cover all annotated genes. Probes were printed seven times on microarray slides. Three biological replicates of total RNA from two wild type strains and from two codY mutant strains were amplified and labeled with Cy3-CTP using Low Input Quick Amp Labeling Kit, one-color(Agilent technologies, US), following the manufacturer’s instructions. Labeled cRNA was purified using the RNeasy mini kit (Qiagen). After fragmentation, microarray slides were hybridized with 600 ng Cy3-labeled cRNA. Hybridization was performed at 65 °C for 17 h with rotation at 10 rpm. Microarray slides were washed and scanned by an Agilent Microarray Scanner (G2565BA). Those genes with greater than two-fold change ratios were regarded as differentially expressed genes. codY mutation induced gene expression in Streptococcus suis serotype 2 SC19 was detected in two wild type and two codY mutated strain of Streptococcus suis serotype 2.
Project description:Streptococcus suis is an important emerging worldwide pig pathogen and zoonotic agent with rapid evolution of virulence and drug resistance. Licochalcone A, used in traditional Chinese medicine, exhibits antimicrobial, antioxidant and anti-inflammatory activities. Herein, a whole-genome DNA microarray was used to investigate the global transcriptional regulation of Streptococcus suis 05ZYH33 treated by subinhibitory concentration of licochalcone A. 132 genes were differentially regulated upon liochalcone A treatment, including 78 genes up-regulated and 54 genes down-regulated which included many central biological functions such as metabolism, transcription and translation. We tried to investigate the antimicrobial mechanism of licochalcone A in the aspect of bacterial cell cycle control. Our analysis indicated that licochalcone A might inhibit the growth of S. suis by controlling the replication initiation and cell division through amino acid metabolism.
Project description:For a pathogen such as Streptococcus suis serotype 2, ecological success is determined by its ability to sense the environment and mount an appropriate adaptive transcriptional response. Thus, determining conditions for analysis of gene expression in vitro that are representative of the in vivo environment is critical for understanding the contributions of transcriptional response pathways to pathogenesis. In this study, we used analysis of the global expression profile in response to acidic pH in vitro and identified a set of regulated genes involved in diverse cellular processes. 196 (11%) genes were differentially regulated by the acid stress: 92 (47%) were down-regulated at low acid (pH 5.8) relative to the neutral condition (pH 7.2), whereas 104 (53%) were up-regulated at pH 5.8 versus pH 7.2. To confirm the microarray data, 16 genes were measured by quantitative RT-PCR. There was a strong positive correlation (r = 0.96) between the results obtained by microarray and quantitative RT-PCR. The data showed that S. suis S2 is equally capable of inducing an acid tolerance response with maximal protection provided after adaptation at pH 5.8 for survival. A cDNA microarray imprinted with 2156 genes representing about 98% of the Streptococcus suis serotype 2 genome was used for transcriptome analysis. For two-sample (reference vs. test) microarray hybridization, four independent bacterial cultures from each condition (pH 5.8, pH 7.2) were prepared as biological replicates for RNA isolation. Accordingly, four dual-fluorescence-labeled cDNA probes were prepared to hybridize with four slides. Pairwise comparisons were made using dye-swaps to avoid labeling bias. A ratio of mRNA levels (test/reference) was calculated for each gene. Significant changes of gene expression were identified with the SAM software. After the SAM analysis, only genes with at least 2-fold changes in expression were collected for further analysis.
Project description:The interactions of Streptocococcus suis (S.suis) with human microvascular endothelial cells (hBMEC) are important process for S.suis passage across human blood brain barrier (BBB). S.suis has evolved precise mechanisms to alter gene expression depending on the distinct challenges posed by particular disease sites. Herein, a whole-genome DNA microarray was used to investigate the change of gene expression profile of S.suis after contact with hBMEC 3 h. comparison of RNA isolated from hBMEC-associated S.suis with RNA derived from control bacteria revealed significant differential changes for 175 S.suis genes including 123 up-regulated genes and 52 down-regulated genes at 3 h post infection. A cDNA microarray imprinted with 2156 genes representing about 98% of Streptococcus suis serotype 2 genome was used for transcriptome analysis . For two-sample (reference vs. test) microarray hybridization, Two-condition experiment, control vs contact with hBMEC 3 h, four replicates (two biological replicates, two technical replicates) at each condition.
Project description:The interactions of Streptocococcus suis (S.suis) with human microvascular endothelial cells (hBMEC) are important process for S.suis passage across human blood brain barrier (BBB). S.suis has evolved precise mechanisms to alter gene expression depending on the distinct challenges posed by particular disease sites. Herein, a whole-genome DNA microarray was used to investigate the change of gene expression profile of S.suis after contact with hBMEC 1 h. comparison of RNA isolated from hBMEC-associated S.suis with RNA derived from control bacteria revealed significant differential changes for 219 S.suis genes including 131 up-regulated genes and 88 down-regulated genes at 1 h post infection. A cDNA microarray imprinted with 2156 genes representing about 98% of Streptococcus suis serotype 2 genome was used for transcriptome analysis . For two-sample (reference vs. test) microarray hybridization, Two-condition experiment, control vs contact with hBMEC 1 h, four replicates (two biological replicates, two technical replicates) at each condition.
Project description:MetQ gene of Streptococcus suis serotype 2 deletion strain has attenuated antiphagocytosis. However,the mechanism of antiphagocytosis and pathogenesis of MetQ in SS2 has remained unclear. In this study, stable isotope labeling by amino acids in cell culture (SILAC) based liquid chromatography-mass spectrometry (LC-MS) and subsequent bioinformatics analysis was used to determine differentially expressed proteins of RAW264.7 cells infected with △MetQ and ZY05719, aimed at elucidating the mechanism of antiphagocytosis and innate immunity of macrophages infected by Streptococcus suis.
Project description:For a pathogen such as Streptococcus suis serotype 2, ecological success is determined by its ability to sense the environment and mount an appropriate adaptive transcriptional response. Thus, determining conditions for analysis of gene expression in vitro that are representative of the in vivo environment is critical for understanding the contributions of transcriptional response pathways to pathogenesis. In this study, we used analysis of the global expression profile in response to acidic pH in vitro and identified a set of regulated genes involved in diverse cellular processes. 196 (11%) genes were differentially regulated by the acid stress: 92 (47%) were down-regulated at low acid (pH 5.8) relative to the neutral condition (pH 7.2), whereas 104 (53%) were up-regulated at pH 5.8 versus pH 7.2. To confirm the microarray data, 16 genes were measured by quantitative RT-PCR. There was a strong positive correlation (r = 0.96) between the results obtained by microarray and quantitative RT-PCR. The data showed that S. suis S2 is equally capable of inducing an acid tolerance response with maximal protection provided after adaptation at pH 5.8 for survival.