Project description:Streptococcus pneumoniae (pneumococcus) is a major human respiratory pathogen and a leading cause of bacterial pneumonia worldwide. Small regulatory RNAs (sRNAs), which often act by post-transcriptionally regulating gene expression, have been shown to be crucial for the virulence of S. pneumoniae and other bacterial pathogens. Over 170 putative sRNAs have been identified in S. pneumoniae TIGR4 strain (serotype 4) through transcriptomic studies, and a subset of these sRNAs have been further implicated in regulating pneumococcal pathogenesis. However, there is little overlap in the sRNAs identified among these studies, which indicates that the approaches used for sRNA identification were not sufficiently sensitive and robust and that there are likely many more undiscovered sRNAs encoded in the S. pneumoniae genome. Here, we sought to comprehensively identify sRNAs in Avery's virulent S. pneumoniae strain D39 using two independent RNA-seq based approaches. We developed an unbiased method for identifying novel sRNAs from bacterial RNA-seq data and have further tested the specificity of our analysis program towards identifying sRNAs encoded by both strains D39 and TIGR4. Interestingly, the genes for 15% of the putative sRNAs identified in strain TIGR4 including ones previously implicated in virulence are not present in strain D39 genome suggesting that the differences in sRNA repertoires between these two serotypes may contribute to their strain-specific virulence properties. Finally, this study has identified 67 new sRNA candidates in strain D39, 28 out of which have been further validated, raising the total number of sRNAs that have been identified in strain D39 to 112.
Project description:Streptococcus pneumoniae (pneumococcus) is a major human respiratory pathogen and the leading cause of bacterial pneumonia worldwide. Small regulatory RNAs (sRNAs), which often act by post-transcriptionally regulating gene expression, have been shown to be crucial for the virulence of S. pneumoniae and other bacterial pathogens. Over 170 putative sRNAs have been identified in S. pneumoniae TIGR4 strain (serotype 4) through transcriptomic studies, and a subset of these sRNAs have been further implicated in regulating pneumococcal pathogenesis. However, there was little overlap in the sRNAs identified among these studies, which indicated that the approaches used for sRNA identification were not sufficiently sensitive and robust and that there were likely many more undiscovered sRNAs encoded in the S. pneumoniae genome. Here, we sought to comprehensively identify sRNAs in Avery's virulent S. pneumoniae strain D39 using two independent RNA-seq based approaches. We developed an unbiased method for identifying novel sRNAs from bacterial RNA-seq data and have further tested the specificity of our analysis program towards identifying sRNAs encoded by both strains D39 and TIGR4. Interestingly, the genes for 15% of the putative sRNAs identified in strain TIGR4 including ones previously implicated in virulence were not present in strain D39 genome suggesting that the differences in sRNA repertoires between these two serotypes may contribute to their strain-specific virulence properties. Finally, this study has identified 67 new sRNA candidates in strain D39, 28 out of which have been further validated, raising the total number of sRNAs that have been identified in strain D39 to 112.
Project description:The polyamine biosynthesis gene, speE, in Streptococcus pneumoniae TIGR4 is necessary for survival in murine models of pneumococcal pneumonia. To date, there is no description of polyamine biosynthesis dependent pneumococcal gene expression. In this study, we compared gene expression between the wild-type and biosynthesis deficient (speE) TIGR4 by RNA-Seq analysis.
Project description:Mouse lung RNAseq after infection with Influenza A virus (H1N1, PR/8/34, mouse-adapted) and Streptococcus pneumoniae (serotype 19F, strain BHN 100) Results: Differentially expressed genes were observed after single and co-infection Project: COST_mouse_2021_lung
Project description:Mouse blood transcriptome after infection with Influenza A virus (H1N1, PR/8/34, mouse-adapted) and Streptococcus pneumoniae (serotype 19F, strain BHN 100) Results: Differentially expressed genes were observed after single and co-infection Project: COST_mouse_2021
Project description:Purpose: We recently reported that isogenic deletion of lysine decarboxylase (ΔcadA/SP_0916), an enzyme that catalyzes the biosynthesis of polyamine cadaverine in Streptococcus pneumoniae TIGR4 results in loss of capsular polysaccharide (CPS), which constitutes a novel mechanism of regulation of CPS. Here, we conducted RNA-Seq to elucidate molecular mechanisms of CPS regulation in polyamine synthesis impaired pneumococci. Result: Significantly differentially expressed genes in ΔcadA represent pneumococcal pathways involved in the biosynthesis of precursors for CPS and peptidoglycan. Conclusion: We establish a possible link and interchange between two cellular processes such as high energy demanding capsule production and oxidative stress responses in polyamine synthesis impaired pneumococci (ΔcadA).