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: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).
Project description:Carolacton is a novel biofilm inhibitor that kills biofilm cells of Streptococcus mutans in nanomolar concentrations. Interestingly, Carolacton also inhibits growth of the clinically relevant and human pathogenic bacterium Streptococcus pneumoniae TIGR4. The cellular target of Carolacton is still unknown. Here, we adressed the differential transcription of cellular RNAs when S. pneumoniae TIGR4 was grown in the presence of Carolacton. This was done to identify transcriptional regulatory networks that are directly affected by treatment of the pneumococcus with Carolacton. In order to gain insights into the primary transcriptional response, early time-points were chosen for sampling, which should not reflect secondary responses (e.g. due to differences in growth phase, drop in pH etc.). To achieve a thorough overview over all affected cellular RNA species, such as mRNAs, small regulatory RNAs and tRNAs, and not to lose small transcripts during library preparation, RNAs were separated according to size and used to construct two separate libraries for sequencing.
Project description:The polyamine transport operon in Streptococcus pneumoniae TIGR4 is necessary for survival in murine models of pneumococcal pneumonia. To date, there is no description of polyamine transport dependent pneumococcal gene expression. In this study, we compared gene expression between the wild-type and transport deficient (potABCD) TIGR4 by RNA-Seq analysis.
Project description:TIGR4 and R6 bacterial strains of Streptococcus pneumoniae treated and not treated with the iron chelator deferoxamine mesylate (DFO)