Global transcriptional responses of pneumococcus to human blood components and cerebrospinal fluid
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ABSTRACT: This study investigates the global transcriptional response of Streptococcus pneumoniae D39V (serotype 2 strain) to human blood components and CSF acquired from discarded and anonymized patient samples.
Project description:Streptococcus pneumoniae (pneumococcus) is a leading cause of severe invasive infectious diseases such as sepsis and meningitis. Understanding how pneumococcus adapts and survive in the human bloodstream environment and cerebrospinal fluid (CSF) is important for development of future treatment strategies. This study investigates the global transcriptional response of pneumococcus to human blood components and CSF acquired from discarded and anonymized patient samples. Extensive transcriptional changes to human blood components were observed during early stages of interaction. Plasma-specific responses were primarily related to metabolic components and include strong downregulation of fatty acid biosynthesis genes, and upregulation of nucleotide biosynthesis genes. No transcriptional responses specific to the active plasma proteins (e.g., complement proteins) were observed during early stages of interaction as demonstrated by a differential expression analysis between plasma and heat-inactivated plasma. The red blood cell (RBC)-specific response was far more complex, and included activation of the competence system, differential expression of several two-component systems, phosphotransferase systems and transition metal transporter genes. Interestingly, most of the changes observed for CSF were also observed for plasma. One of the few CSF-specific responses, not observed for plasma, was a strong downregulation of the iron acquisition system piuBCDA. Intriguingly, this transcriptomic analysis also uncovers significant differential expression of more than 20 small non-coding RNAs, most of them in response to RBCs, including small RNAs from uncharacterized type I toxin-antitoxin systems. In summary, this transcriptomic study identifies key pneumococcal metabolic pathways and regulatory genes involved with adaptation to human blood and CSF. Future studies should uncover the potential involvement of these factors with virulence in-vivo.
Project description:We reported that the microRNA profiling of exosome isolated from 58 cerebrospinal fluid (CSF) of 38 medulloblastoma (MBL) patient with or without letomeningeal metastases (LM). CSF exosome was precipitated using Exo2DTM for RNA assay (EXOSOME plus, Suwon, South Korea) according to the manufacture’s protocol (Kim, et al. 2017). 2 ml of CSF were added to Exo2DTM reagent B following mixing by inverting, and incubated at room temperature for 30 min. The supernatant was discarded and the exosome containing pellet was resuspended in 100 ul of PBS to further RNA isolation. Total RNA was extracted from the CSF exosome fraction using a microRNA purification kit (Norgen Biotek corp., Thorold, Canada) according to the manufacture’s protocol. Briefly, samples were mixed with lysis buffer, and the lysate was added to absolute ethanol. The lysate was applied up to the column and centrifuged at 8,000 rpm for 1 min. The column was washed with wash solution and centrifuged at 14,000 rpm for 1 min. Finally, the column was applied to 20 ul of elution solution and centrifuged at 14,000 rpm for 2 min, and the flow-through was stored at –80 ℃ for storage. RNA precipitates were quantified and qualified with Bioanalyzer Pico 6000 Chip (Agilent Technologies, Santa Clara, CA). The 10 ng of total RNA was provided to the cDNA library generation using SMARTer smRNA-Seq kit (Illumina Inc., San Diego, CA), according to the user manual. The cDNA library was subjected to sequencing using Truseq SBS Kit and HiSeq 2500 System (Illumina Inc., San Diego, CA), according to user guide.
Project description:Diagnostic primer extension assay to serotype Streptococcus pneumoniae. Assay validation. Background: Monitoring of Streptococcus pneumoniae serotype epidemiology is essential since serotype replacement is a concern when introducing new polysaccharide-conjugate vaccines. To simplify S. pneumoniae serotyping, a novel PCR-based automated microarray assay was developed to assist in the tracking of the serotypes. Results: Autolysin (lytA), pneumolysin (ply) and eight genes located in the capsular operon (cps) were amplified using multiplex PCR. This step was followed by a tagged fluorescent primer extension step targeting serotype-specific polymorphisms. The tagged primers were then hybridized to a microarray. Results were exported to an expert system that transforms genetic typing data into capsular serotype identification. The assay was validated on 166 cultured S. pneumoniae samples from 63 different serotypes as determined by the Quellung method. In addition, the assay was tested on clinical specimens including 43 cerebrospinal fluid samples from patients with meningitidis and 59 nasopharyngeal aspirates from bacterial pneumonia patients. The assay presented with no cross-reactivity for 24 relevant bacterial species found in these types of samples. The limit of detection for serotyping and S. pneumoniae detection was 100 genome equivalent per reaction. Conclusion: This automated assay is amenable to clinical testing and does not require any culturing of the samples. The assay will be useful for the evaluation of serotype prevalence changes after new conjugate vaccines introduction.
Project description:To determine whether the microRNA content of CSF vesicles changes throughout life we performed experiments including miRNA microarrays. Hierarchical clustering analysis indicated that the miRNA content of CSF vesicles changes when patients less than 2 years are compared to those older than 70 years of age. CSF vesicles were fractionated and isolated from patients of different ages, total RNA extracted, and subjected to miRNA microarray analysis
Project description:We sequenced mRNA form 4 Streptococcus pneumoniae which expressed only a single HsdS variant of the phase variable type I restriction modification system. Samples were from mid log exponential growth phase in standard glucose containing growth medium.
Project description:Diagnostic primer extension assay to serotype Streptococcus pneumoniae. Assay validation. Background: Monitoring of Streptococcus pneumoniae serotype epidemiology is essential since serotype replacement is a concern when introducing new polysaccharide-conjugate vaccines. To simplify S. pneumoniae serotyping, a novel PCR-based automated microarray assay was developed to assist in the tracking of the serotypes. Results: Autolysin (lytA), pneumolysin (ply) and eight genes located in the capsular operon (cps) were amplified using multiplex PCR. This step was followed by a tagged fluorescent primer extension step targeting serotype-specific polymorphisms. The tagged primers were then hybridized to a microarray. Results were exported to an expert system that transforms genetic typing data into capsular serotype identification. The assay was validated on 166 cultured S. pneumoniae samples from 63 different serotypes as determined by the Quellung method. In addition, the assay was tested on clinical specimens including 43 cerebrospinal fluid samples from patients with meningitidis and 59 nasopharyngeal aspirates from bacterial pneumonia patients. The assay presented with no cross-reactivity for 24 relevant bacterial species found in these types of samples. The limit of detection for serotyping and S. pneumoniae detection was 100 genome equivalent per reaction. Conclusion: This automated assay is amenable to clinical testing and does not require any culturing of the samples. The assay will be useful for the evaluation of serotype prevalence changes after new conjugate vaccines introduction. 166 quellung serotyped strains and two negative controls
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: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:Transcriptional effects in liver, lung and blood samples from mice after intratracheal challenge with either Streptococcus pneumoniae serotype 19 (lobar-pneumonia) or serotype 2 (sepsis) were monitored after 6 and 24 hours and compared to sham (vehicle control). We gratefully acknowledge the BMBF grant within the “Promoting global research excellence in severe sepsis” (PROGRESS) study (01KI07111).
Project description:Streptococcus pneumoniae is the most frequent cause of community-acquired pneumonia. Endogenous antimicrobial proteins such as PGLYRP4 might participate to the course of the disease. PGLYRP4 is expressed in different cell types but is downregulated in alveolar epithelial after stimulation with Streptococcus pneumoniae. Interestingly, mice lacking PGLYRP4 displayed an enhanced bacterial clearance in the lungs and less mice develop a bacteremia. We investigated the gene expression in alveolar macrphages and found most top 50 up- and down-regulated genes to be not annotated. Genes which could be annotated seem unlikely to play a major role in the phenotype of PGLYRP4-KO mice. We implemented microarray analysis of infected primary alveolar macrophage cells to identify possible regulated genes by PGLYPR4-deficency, which contribute to the seen phenotype.