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: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:Analysis of the pulmonary gene expression in two mouse strains BALB/cOlaHsd (BALB/c) and CBA/CaOlaHsd (CBA/Ca) after infection with various serotypes of Streptococcus pneumoniae. BALB/c mice show high resistance to infection with S. pneumoniae strain D39 (serotype 2), while CBA/Ca mice are highly susceptible. The lung samples of BALB/c and CBA/Ca were collected at 6h post-infection with one of the tested pneumococcal serotypes (2, 3, 6B and 19F) and for control animals (PBS-treated). Additionally lung samples from both mouse strains were collected at 12h and 24h post-infection with pneumococcal strain D39. The lists of differentially expressed genes were created by the comparison of infected versus PBS-treated animals and infected BALB/c versus infected CBA/Ca for each pneumococcal strain. The tested hypotheses were: 1) infection with S. pneumoniae will change the pulmonary transcriptomes of both mouse strains 2) The pulmonary gene expression will be specific for mouse strains and for the pneumococcal serotype and 3) The change in the pulmonary gene expression will associate with future clinical outcome of infection or with the type of observed inflammatory responses. Total RNA obtained from lung tissue from BALB/cOlaHsd and CBA/CaOlaHsd mouse strains (Harlan) post intranasal infection with Streptococcus pneumoniae of various serotypes (2, 3, 6B and 19F) dose 5.0E06 CFU or PBS-treated animals
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:Background: Pneumococcal secondary infection following influenza A virus (IAV) pneumonia is a synergistic complication with high mortality. While varying invasiveness of pneumococcal serotypes is an important pathogenic factor, serotype-specifc immediate-early transcriptional responses of the IAV-perturbed alveolar epithelium have not been adressed. We comprehensively analyzed gene transcription in alveolar type II epithelial cells (AECII) isolated from mice infected with IAV and/or S. pneumoniae (S.pn.) serotypes 4, 7F and 19F. Results: IAV, 14 days post infection, rendered the lung susceptible to invasive secondary S.pn. infection with serotypes 4 and 7F but not 19F. Only secondary 7F infection induced exacerbated cytokine/chemokine responses. IAV/7F infection induced superior protein expression of type I and II interferons, acesserbated expression in IAV/serotype 4 infection. Inference of a scale-free-like ARACNE gene co-expression network revealed interferon-response network modules in AECII and network-mapping unfolded S.pn. serotype-specific transcriptional network responses/usage. Secondary S.pn. infection abrogated the IAV-induced pneumocyte proliferative configuration and preceeding IAV infection rendered the transcriptional response to 7F infection comparable to that towards serotype 4. This related especially to network genes correlating with the expression of two master regulators of interferon responses: Irf7 and Stat1. Epigenetic ATAC-seq analysis of AECII in resolved IAV infection identified enhanced expression of ARACNE network genes Hist1h2bf, Igtp, Mki67, Rasl10b, H2-Q6 and H2-Q7 to be associated with increased chromatin accessability at promoter regions. Conclusions: We show that AECII sustainably retain an IAV-associated transcriptional configuration with epigenetic involvement, that serotype-specifically affects proliferation and accelerates and enhances the AECII transcriptional response, mainly to interferons, in secondary S.pn. infection.
Project description:Transcriptional profiling of primary human alveolar macrophages (AMs) comparing control untreated AMs with AMs exposed with Serotype 14 Streptococcus pneumoniae (NCTC11902) strain (MOI 10) for 4 hours) Two-condition experiment, control AMs vs. infected AMs. Biological replicates: 3 control replicates, 3 infected replicates MOI 10.