Streptococcus pneumoniae
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA98413 | ENA |
REPOSITORIES: ENA
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Project description:RNases perform indispensable functions in regulating gene expression in many bacterial pathogens by processing and/or degrading RNAs. Despite the pivotal role of RNases in regulating bacterial virulence factors, the functions of RNases have not yet been studied in the major human respiratory pathogen Streptococcus pneumoniae (pneumococcus). Here, we sought to determine the impact of two conserved RNases, the endoribonuclease RNase Y and exoribonuclease polynucleotide phosphorylase (PNPase), on the physiology and virulence of S. pneumoniae serotype 2 strain D39. We report that RNase Y and PNPase are essential for pneumococcal pathogenesis as both deletion mutants showed strong attenuation of virulence in murine models of invasive pneumonia. Genome-wide transcriptomic analysis revealed that nearly 200 mRNA transcripts were significantly up-regulated, whereas the abundance of several pneumococcal sRNAs, including the Ccn (CiaR Controlled Noncoding RNA) sRNAs, were altered in the ∆rny mutant relative to the wild-type strain. Additionally, lack of RNase Y resulted in pleiotropic phenotypes that included defects in pneumococcal cell morphology and growth in vitro. In contrast, Dpnp mutants showed no growth defect in vitro, but differentially expressed a total of 40 transcripts including the tryptophan biosynthesis operon genes and numerous 5’-cis-acting regulatory RNAs, a majority of which were previously shown to impact pneumococcal disease progression in mice using the serotype 4 strain TIGR4. Altogether our data suggest that RNase Y exerts a global impact on pneumococcal physiology, while PNPase-mediates virulence phenotypes, likely through sRNA regulation.
2021-09-02 | GSE173392 | GEO
Project description:LuxS signaling system and regulation of pneumococcal genes
| PRJNA93063 | ENA
Project description:Segregation of replicated chromosomes during cell division is an essential process in all organisms. Chromosome segregation is promoted by the action of the DNA-binding ParB protein in the rod-shaped model bacterium Bacillus subtilis. How oval shaped bacteria, such as the human pathogen Streptococcus pneumoniae, efficiently segregate their chromosomes is poorly understood. Here, we show that the pneumococcal homolog of ParB is enriched at four centromere-like DNA sequences (parS sites) that are present near the origin of replication.
2011-06-11 | GSE26839 | GEO
Project description:The primary mechanism by which pneumococcal capsular polysaccharide-based vaccines are believed to mediate protection is by induction of serotype-specific opsonic antibodies that facilitate bacterial killing by phagocytes (opsonophagocytosis). However, antibodies that are protective against experimental pneumococcal pneumonia in mice but do not promote opsonophagocytic killing in vitro have also been identified 1-3. Such non-opsonic antibodies are associated with bacterial clearance in vivo, but the mechanism by which this occurs is unknown. In this letter, we demonstrate that a protective, non-opsonic serotype 3 pneumococcal capsular polysaccharide-specific monoclonal antibody (MAb) enhances quorum sensing, which results in competence induction and fratricide of serotype 3 pneumococcus. Gene expression profile analysis revealed that the MAb together with the pneumococcal autoinducer, competence stimulating peptide 2 (CSP2), augments differential expression of competence (com) related bacteriocin-like peptide (blp) genes that are known to be involved in pneumococcal fratricide. Taken together, these findings reveal a previously unsuspected mechanism of antibody action, namely, enhancement of quorum sensing and bacterial fratricide. Given that this activity does not require phagocytes, antibodies that function accordingly may hold promise as adjuncts to current vaccines or as desired products of next generation pneumococcal vaccines.
2011-03-01 | GSE27258 | GEO
Project description:Galactose promotes pneumococcal biofilms in vivo
2016-08-04 | GSE85196 | GEO
Project description:The primary mechanism by which pneumococcal capsular polysaccharide-based vaccines are believed to mediate protection is by induction of serotype-specific opsonic antibodies that facilitate bacterial killing by phagocytes (opsonophagocytosis). However, antibodies that are protective against experimental pneumococcal pneumonia in mice but do not promote opsonophagocytic killing in vitro have also been identified 1-3. Such non-opsonic antibodies are associated with bacterial clearance in vivo, but the mechanism by which this occurs is unknown. In this letter, we demonstrate that a protective, non-opsonic serotype 3 pneumococcal capsular polysaccharide-specific monoclonal antibody (MAb) enhances quorum sensing, which results in competence induction and fratricide of serotype 3 pneumococcus. Gene expression profile analysis revealed that the MAb together with the pneumococcal autoinducer, competence stimulating peptide 2 (CSP2), augments differential expression of competence (com) related bacteriocin-like peptide (blp) genes that are known to be involved in pneumococcal fratricide. Taken together, these findings reveal a previously unsuspected mechanism of antibody action, namely, enhancement of quorum sensing and bacterial fratricide. Given that this activity does not require phagocytes, antibodies that function accordingly may hold promise as adjuncts to current vaccines or as desired products of next generation pneumococcal vaccines. 6 samples
2011-03-01 | E-GEOD-27258 | biostudies-arrayexpress
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).
2019-09-30 | GSE130511 | GEO
Project description:Treatment of pneumococcal infections is limited by antibiotic resistance and exacerbation of disease by bacterial lysis releasing pneumolysin toxin and other inflammatory factors. We identified a novel peptide in the Klebsiella pneumoniae secretome, which enters Streptococcus pneumoniae via its AmiA-AliA/AliB permease. Subsequent downregulation of genes for amino acid biosynthesis and peptide uptake was associated with reduction of pneumococcal growth in defined medium and human cerebrospinal fluid, irregular cell shape, decreased chain length and decreased genetic transformation. The bacteriostatic effect was specific to S. pneumoniae and Streptococcus pseudopneumoniae with no effect on Streptococcus mitis, Haemophilus influenzae, Staphylococcus aureus or K. pneumoniae. Peptide sequence and length were crucial to growth suppression. The peptide reduced pneumococcal adherence to primary human airway epithelial cell cultures and colonization of rat nasopharynx, without toxicity. We also analysed the effect of peptide on the proteome of S. pneumoniae. We found alteration of the proteome by the peptide with some proteins turned on or off in line with the transcriptomic changes. We therefore identified a peptide with potential as a therapeutic for pneumococcal diseases suppressing growth of multiple clinical isolates, including antibiotic resistant strains, while avoiding bacterial lysis and dysbiosis.
2024-04-08 | PXD050408 | Pride
Project description:We used a combination of adherence assays, mutagenesis and functional genomics to identify novel factors involved in adherence. This work identifies a list of novel potential pneumococcal adherence determinants.
2013-09-30 | GSE44947 | GEO
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.
2023-01-01 | E-MTAB-6070 | biostudies-arrayexpress