Project description:Young adult N2 Caenorhabditis elegans were infected with Enterococcus faecalis or Enterococcus faecium for 8 h to determine the transcriptional host response to each enterococcal species. Analysis of differential gene expression in C. elegans young adults exposed to four different bacteria: heat-killed Escherichia coli strain OP50 (control), wild-type E. faecalis MMH594, wild-type E. faecium E007, or Bacillus subtilis PY79 (sigF::kan). Samples were analyzed at 8 hours after exposure to the different bacteria. These studies identified C. elegans genes induced by pathogen infection. Brain-heart infusion agar plates (10 ug/ml kanamycin) were used.
Project description:The enterococci comprise a genus of 49 low-GC content Gram-positive commensal species within the Firmicutes phylum that are known to occupy diverse habitats, notably the gastrointestinal core microbiota of nearly every phylum, including human. Of particular clinical relevance are two rogue species of enterococci, Enterococcus faecalis and the distantly related Enterococcus faecium, standing among the nefarious multi-drug resistant and hospital-acquired pathogens. Despite increasing evidence for RNA-based regulation in the enterococci, including regulation of virulence factors, their transcriptome structure and arsenal of regulatory small sRNAs (sRNAs) are not thoroughly understood. Using dRNA-seq, we have mapped at single-nucleotide resolution the primary transcriptomes of E. faecalis V583 and E. faecium AUS0004. We identified 2517 and 2771 transcription start sites (TSS) in E. faecalis and E. faecium, respectively. Based on the identified TSS, we created a global map of s70 promoter motifs. We also revealed features of 5’ and 3’UTRs across the genomes. The transcriptome maps also predicted 150 and 128 sRNA candidates in E. faecalis and E. faecium, respectively, some of which have been identified in previous studies and many of which are new. Finally, we validated several of the predicted sRNAs by Northern Blot in biologically relevant conditions. Comprehensive TSS mapping of two representative strains will provide a valuable resource for the continued development of RNA biology in the Enterococci.
Project description:This study was undertaken to identify how gene expression of the urothelial cells respond to Enterococcus infection over the course of infection. 239 hypervariable (HV) genes were found to vary significantly over the time points, indicating a biological role in infection. Correlational clustering showed these HV genes fell into distinct families indicating a defined sequence of events following infection. Early events (0-1.5 hours post infection) were associated with upregulation of not well-known but bladder-associated genes which represented early immune response, cytoskeleton remodeling and cell cycle. Up- and downregulated genes at the middle time period (1.5-8 hours post infection) represented a variety of processes, from immune response/suppression, cell cycle/apoptosis to metabolism and cytoskeleton remodeling. Several transcription factors point to multiple pathways activation. At the late time points (8-10 hours post infection) downregulated genes represented major events of cell death, matrix degradation and immune response decline. Confocal microscopy confirms major cell death at these time points. Several events and pathways, like immune response suppression or cytoskeleton remodeling via Wnt/β-catenin and/or Rho/Rac pathway, were identified throughout the time course of HUC infection by Enterococcus. Those may be new targets for preventing and/or cure Enterococcus caused pathology. Keywords: Enterococcus, time course, microarray, infection, gene expression
Project description:To further investigate the homeostatic response of E. faecalis to Fe exposure, we examine the whole-genome transcriptional response of wild-type (WT) exposed to non toxic Fe excess. This experiment correspond the work titled Transcriptomic response of Enterococcus faecalis to iron excess (work in preparation) A four chip study using total RNA recovered from four separate wild-type cultures of Enterococcus faecalis OG1RF, two controls samples (N medium growth) and two iron samples (N medium gowth with 0.5 mM Fe-NTA). Each chip measures the expression level of 3,114 genome genes from Enterococcus faecalis strain V583 (A7980-00-01).
Project description:We investigated the RNA-protein interactome of Enterococcus faecalis V583 and Enterococcus faecium Aus0004 by native gradient fractionation of complexes coupled to RNA-sequencing. Whole bacterial cell lysates were analysed by size and density in a glycerol gradient. At native conditions, RNA-protein complexes stay intact and sediment as a whole. Sedimentation profiles of individual RNAs appear correlated in case of interaction in a complex. The profile of KhpB caught our attention and we determined its RNA interactome by immunoprecipitation that suggests a role at the post-transcriptional level, binding notably several tRNAs, sRNAs, and 3’UTRs.
Project description:Comparative genomic hybridization analysis of diverse Enterococcus faecalis strains to determine core species genome.<br>An additional data file, Gilmore_M-Genomotyping_Tables_12-21-2006.xls, containing information about data processing is available for download from <a href="ftp://ftp.ebi.ac.uk/pub/databases/microarray/data/experiment/MEXP/E-MEXP-1090/">ftp://ftp.ebi.ac.uk/pub/databases/microarray/data/experiment/MEXP/E-MEXP-1090/</a>
Project description:Enterococcus faecalis is a common commensal organism and a prolific nosocomial pathogen that causes biofilm-associated infections. Numerous E. faecalis OG1RF genes required for biofilm formation have been identified, but few studies have compared genetic determinants of biofilm formation and biofilm morphology across multiple conditions. Here, we cultured transposon (Tn) libraries in CDC biofilm reactors in two different media and used Tn sequencing (TnSeq) to identify core and accessory biofilm determinants, including many genes that are poorly characterized or annotated as hypothetical. Multiple secondary assays (96-well plates, submerged Aclar, and MultiRep biofilm reactors) were used to validate phenotypes of new biofilm determinants.
Project description:Analysis of changes in gene expression in Enterococcus faecalis OG1 delta-EF2638 mutant compared to wild-type OG1 strain. The deletion mutant has a growth defect when grown with aeration The mutant presented in this study is described and characterized in Vesic, D. and Kristich, C.J. 2012. A Rex-family transcriptional repressor influnces H2O2 accumulation by Enterococcus faecalis. (submitted for publication) Microarray analysis was done using RNA isolated from two independent cultures of wild-type Enterococcus faecalis OG1 and two independent cultres of Enterococcus faecalis OG1 delta-EF2638 mutant; each RNA sample was subjected to triplicate hybridization (technical replicates) . Microarrays were custom designed to investigate expression of ORFs in Enterococcus faecalis OG1RF genome. The arrays were designed based on the OG1RF annotation generated with the Rapid Annotation Using Subsystem Technology (RAST) server (Aziz et. al. 2008. BMC Genomics 9:75), as described in Frank et al (2012) Infect. Immun. 80:539. The aim was eighteen probe pairs per ORF, each of which is present in triplicate.
Project description:To further investigate the homeostatic response of E. faecalis to Fe exposure, we examine the whole-genome transcriptional response of wild-type (WT) exposed to non toxic Fe excess. This experiment correspond the work titled Transcriptomic response of Enterococcus faecalis to iron excess (work in preparation)