Project description:Transcriptional profiling of two disinfectant-resistant Listeria monocytogenes strains indentified in a Iberian pork plant, S1 [160908] vs S10_1 [160908], in presence of 1.25 mg/L of Benzalkonium chloride
Project description:Transcriptional profiling of two disinfectant-resistant Listeria monocytogenes strains indentified in a Iberian pork plant, S1 [160908] vs S10_1 [160908], in presence of 1.25 mg/L of Benzalkonium chloride One condition experiment, S1 [160908] vs. S10_1 [160908] strains. Biological replicates: 3 replicates of S1 [160908], 3 replicates of S10 [160908].
Project description:Background: Meningitis can be caused by several viruses and bacteria. Identifying the causative pathogen as quickly as possible is crucial to initiate the most optimal therapy, as acute bacterial meningitis is associated with a significant morbidity and mortality. Bacterial meningitis requires antibiotics, as opposed to enteroviral meningitis, which only requires supportive therapy. Clinical presentation is usually not sufficient to differentiate between viral and bacterial meningitis, thereby necessitating cerebrospinal fluid (CSF) analysis by PCR and/or time-consuming bacterial cultures. However, collecting CSF in children is not always feasible and a rather invasive procedure. Methods: In 12 Belgian hospitals, we obtained acute blood samples from children with signs of meningitis (49 viral and 7 bacterial cases). (aged between 3 months and 16 years). After pathogen confirmation on CSF, the patient was asked to give a convalescent sample after recovery. 3’mRNA sequencing was performed to determine differentially expressed genes (DEGs) to create a host transcriptomic profile. Results: Enteroviral meningitis cases displayed the largest upregulated fold change enrichment in type I interferon production, response and signaling pathways. Patients with bacterial meningitis showed a significant upregulation of genes related to macrophage and neutrophil activation. We found several significantly DEGs between enteroviral and bacterial meningitis. Random forest classification showed that we were able to differentiate enteroviral from bacterial meningitis with an AUC of 0.982 on held-out samples. Conclusions: Enteroviral meningitis has an innate immunity signature with type 1 interferons as key players. Our classifier, based on blood host transcriptomic profiles of different meningitis cases, is a possible strong alternative for diagnosing enteroviral meningitis.
Project description:Tuberculous meningitis is one of the fatal forms of extra pulmonary disease associated with high mortality and severe neurological defects in affected individuals. We have carried out transcriptome level analysis using whole human genome microarrays to identify differential expression of genes between tuberculous meningitis and normals. In our gene expression analysis, we found 2,434 genes that were differentially erexpressed with 2 or more than 2 fold changes between tuberculous meningitis compared to normal cases. Most of the genes encoded many of the proteins, which involves metabolism, energy pathways, cell growth and/or maintenance, transport and cell communication and signal transduction. We have performed immunohistochemistry for the validation of some of the novel candidates identified in our microarray studies.!Series_overall_design = Present study carried out mRNA expression profiling of five samples from patients diagnosed with tuberculous meningitis and four head injury cases were used as controls. We have used 4X44K arrays from agilent plaform. To validate our microarray results, we have done Immunohistochemistry on 15 TBM cases with control groups.
Project description:The aim of present study was to describe the genetic pathways activated during the community acquired bacterial meningitis (BM) by using genome-wide RNA expression profiling combined with functional annotation of transcriptional changes. We included 21 patients with BM hospitalized in 2008. The control group consisted of 18 healthy subjects. The RNA was extracted from whole blood, globin mRNA was depleted and gene expression profiling was performed with GeneChip Human Gene 1.0 ST Arrays enabling the analysis of 28,869 genes. Gene expression profile data were analyzed using Bioconductor packages and Bayesian modeling. Functional annotation of the enriched gene sets was used to define changed genetic networks. We also analyzed if the gene expression profile depends on the clinical course and outcome. In order to verify the genechip results, we chose ten functionally relevant genes with high statistical significance (CD177, IL1R2, IL18R1, IL18RAP, OLFM4, TLR5, CPA3, FCER1A, IL5RA, IL7R) and performed quantitative real-time (qRT) PCR.We identified the significant differences at p values of <0.05 in 8569 genes and after False Discovery Rate (FDR) correction, total of 5500 genes remained significant at p value of <0.01. Quantitative RT-PCR confirmed differential expression for selected genes. Functional annotation and network analysis indicated that most of the genes were related to activation of humoral and cellular immune responses (enrichment score 43). Those changes were found in adults and in children with BM compared to the healthy controls. Gene expression profile didn’t depend on the clinical outcome, but there was very strong influence by the type of the pathogen. This study demonstrates a strong functional genomic evidence of the over-active immune response during bacterial meningitis. This hyperactive response possibly explains the complicated clinical course of this disease. 22 bacterial meningitis patients and 18 healthy controls
Project description:Tuberculous meningitis is one of the fatal forms of extra pulmonary disease associated with high mortality and severe neurological defects in affected individuals. We have carried out transcriptome level analysis using whole human genome microarrays to identify differential expression of genes between tuberculous meningitis and normals. In our gene expression analysis, we found 2,434 genes that were differentially erexpressed with 2 or more than 2 fold changes between tuberculous meningitis compared to normal cases. Most of the genes encoded many of the proteins, which involves metabolism, energy pathways, cell growth and/or maintenance, transport and cell communication and signal transduction. We have performed immunohistochemistry for the validation of some of the novel candidates identified in our microarray studies.!Series_overall_design = Present study carried out mRNA expression profiling of five samples from patients diagnosed with tuberculous meningitis and four head injury cases were used as controls. We have used 4X44K arrays from agilent plaform. To validate our microarray results, we have done Immunohistochemistry on 15 TBM cases with control groups. Present study carried out mRNA expression profiling of five samples from patients diagnosed with tuberculous meningitis and four head injury cases were used as controls. We have used 4X44K arrays from agilent plaform. To validate our microarray results, we have done Immunohistochemistry on 15 TBM cases with control groups.!Series_type = Expression profiling by array
Project description:Meningitis is a complex disease which can be caused by infection with either viral or bacterial pathogens. Viral meningitis is usually a sterile self-limiting disease with a good clinical prognosis, while bacterial meningitis is a potentially more serious disease with a higher mortality rate. Early diagnosis of bacterial meningitis is of paramount importance, as intervention with antimicrobial therapy increases the likelihood of a favourable clinical outcome. Routine diagnosis in many laboratories is still dependent to some degree on traditional methods e.g. culture, though molecular methods have been developed which can give a shorter time to diagnosis. However, there is not as yet a single test format that can detect all bacterial pathogens capable of causing meningitis. In addition, many tests e.g. real-time PCR have a finite limit for multiplexing and do not provide additional information such as strain or serogroup which is useful during outbreaks and for retrospective epidemiological surveillance. To this end we have developed a microarray probe set for detection of meningitis-associated bacterial pathogens including those in the N. meningitidis serogroups. Here we demonstrate utility of this array in specific detection of represented bacterial species and strains and in detection of pathogen signals in cerebrospinal fluid samples from patients with suspected bacterial meningitis. This method shows promise for development as a diagnostic tool; however, we discuss the technical issues encountered and suggest mechanisms to improve resolution of pathogen-specific signals in complex clinical samples.
Project description:Tuberculosis co-infected with HIV may increase the risk of causing meningitis. Tuberculous meningitis co-infected with HIV associated with high mortality and severe neurological abnormalities in affected individuals. We have carried out TBM co-infected with HIV gene expression study using whole human genome microarrays. We identified 796 differentially expressed genes with fold change cut off of 2 or more than 2. Out of 796 differentially expressed genes, 398 were upregulated and 396 were downregulated. We have validated two molecules from microarray data using immunohistochemistry.
Project description:We applied genomic array footprinting (GAF) in the search for genes of S. pneumoniae essential during the establishment and progression of experimental meningitis. Four libraries with a total of 6,000 independent TIGR4 marinerT7 transposon mutants were injected intra-cisternally in rabbits, and cerebrospinal fluid (CSF) was collected after three, nine, and fifteen hours. Microarray analysis of mutant-specific probes from CSF samples and inocula identified 82 genes of which mutants had become attenuated and eleven genes of which mutants had become enriched during infection. Screening results particularly point to an essential role for capsular polysaccharides (cps), nutrient uptake, and metabolism in meningitis. Detailed study on directed mutants of a subset of sixteen GAF targets in an experimental model of rat meningitis revealed that ten were significantly attenuated or enriched during competitive infection. Furthermore, we showed that mutants of adenylosuccinate synthetase (purA), flavodoxin (fld), and the substrate binding protein (livJ) of a branched chain amino acid ABC-transporter were essential for full blown meningitis in a mono-infection setup of rat meningitis. Overall, the GAF screen revealed the general restraint on nutrients encountered by the pneumococcus in CSF, while, except for cps genes, no ‘classic’ virulence factors appeared to be required for infection. This knowledge will contribute to a better understanding of the molecular pathogenesis of pneumococcal meningitis.
Project description:The aim of present study was to describe the genetic pathways activated during the community acquired bacterial meningitis (BM) by using genome-wide RNA expression profiling combined with functional annotation of transcriptional changes. We included 21 patients with BM hospitalized in 2008. The control group consisted of 18 healthy subjects. The RNA was extracted from whole blood, globin mRNA was depleted and gene expression profiling was performed with GeneChip Human Gene 1.0 ST Arrays enabling the analysis of 28,869 genes. Gene expression profile data were analyzed using Bioconductor packages and Bayesian modeling. Functional annotation of the enriched gene sets was used to define changed genetic networks. We also analyzed if the gene expression profile depends on the clinical course and outcome. In order to verify the genechip results, we chose ten functionally relevant genes with high statistical significance (CD177, IL1R2, IL18R1, IL18RAP, OLFM4, TLR5, CPA3, FCER1A, IL5RA, IL7R) and performed quantitative real-time (qRT) PCR.We identified the significant differences at p values of <0.05 in 8569 genes and after False Discovery Rate (FDR) correction, total of 5500 genes remained significant at p value of <0.01. Quantitative RT-PCR confirmed differential expression for selected genes. Functional annotation and network analysis indicated that most of the genes were related to activation of humoral and cellular immune responses (enrichment score 43). Those changes were found in adults and in children with BM compared to the healthy controls. Gene expression profile didn’t depend on the clinical outcome, but there was very strong influence by the type of the pathogen. This study demonstrates a strong functional genomic evidence of the over-active immune response during bacterial meningitis. This hyperactive response possibly explains the complicated clinical course of this disease.