Project description:Purpose: Examining the transcriptome of Bacteroides thetaiotaomicron VPI-5482 challenged with Bacteroides phage to assess surface molecule expression changes Methods: Bacteroides thetaiotaomicron was grown in BPRM in vitro or Germ-Free mice were monocolonized with Bacteroides thetaiotaomicron and gavaged with ARB25 phage. Fold change was calculated as live phage versus heat-killed phage treated samples with n=3 biological replicates. Once cells reached an optical density corresponding to mid-log phase growth (absorbance between 0.4-0.5), RNA was isolated and rRNA depleted. Samples were multiplexed for sequencing on the Illumina HiSeq platform at the University of Michigan Sequencing Core. Data was analyzed using Arraystar software (DNASTAR, Inc.) using DEseq2 normalization with default parameters. Genes with significant up- or down-regulation were determined by the following criteria: genes with an average fold-change >5-fold and with at least 2/3 biological replicates with a normalized expression level >1% of the overall average, and a p-value < 0.05 (t test with Benjamini-Hochberg correction) Results: Specific capsule expression was increased in wild-type B. thetaiotaomicron during phage infection in vitro and in vivo. Many corresponding in vivo genes were upregulated as well as other surface layer proteins.
Project description:The large-scale application of genomic and metagenomic sequencing technologies has yielded a number of insights about the metabolic potential of symbiotic human gut microbes. Bacteria that colonize the mucosal layer that overlies the gut epithelium have access to highly-sulfated polysaccharides (i.e., mucin oligosaccharides and glycosaminoglycans), which they could potentially forage as nutrient sources. To be active, sulfatases must undergo a critical post-translational modification catalyzed in anaerobic bacteria by the AdoMet enzyme anSME (anaerobic Sulfatase-Maturating Enzyme). In the present study, we have tested the role of this pathway in the prominent gut symbiont Bacteroides thetaiotaomicron, which possesses more predicted sulfatases (28) than in the human genome and a single predicted anSME. In vitro studies revealed that deletion of its anSME (BT0238) results in loss of sulfatase activity and impaired ability to use sulfated polysaccharides as carbon sources. Co-colonization of germ-free animals with both isogenic strains, or invasion experiments involving the introduction of one then the other strain, established that anSME activity and the sulfatases that are activated via this pathway, are important fitness factors for B. thetaiotaomicron, especially when mice are fed a simple sugar diet that requires this saccharolytic bacterium to adaptively forage on host glycans as nutrients. Whole genome transcriptional profiling of wild-type and the anSME mutant in vivo revealed that loss of this enzyme alters expression of genes involved in mucin utilization and that this disrupted ability to access mucosal glycans likely underlies the observed dramatic colonization defect. Comparative genomic analysis reveals that 100% of 46 fully sequenced human gut Bacteroidetes contain homologs of BT0238 and genes encoding sulfatases, suggesting that this is an important and evolutionarily conserved feature. Three replicate samples from 4 different biological treatment groups: 1. Wild-type B. thetaiotaomicron from the cecum of gnotobiotic mice fed a simple-sugar diet; 2. chuR mutant B. thetaiotaomicron from the cecum of gnotobiotic mice fed a simple-sugar diet; 3. Wild-type B. thetaiotaomicron from the cecum of gnotobiotic mice fed a plant-rich diet; 4. chuR mutant B. thetaiotaomicron from the cecum of gnotobiotic mice fed a plant-rich diet.
Project description:We report next generation sequencing RNA-seq data of human gut commensal Bacteroides thetaiotaomicron strains deficient in inositol lipid synthesis, including dBT_1522 (phosphoinositol dihydroceramide synthase knockout) and its wild-type background strain, and iSPTdBT_1526 (myo-inositol-phosphate synthase) knockout with its background strain ("iSPT," inducible serine palmitoyltransferase).
Project description:Analysis of the Bacteroides thetaiotaomicron(BT) transcriptome during co-culture with Caco-2 intestinal epithelial cells To identify potential bacterial protein(s) involved in the anti-inflammatory effect of BT in colitis, BT was incubated with Caco-2 human intestinal epithelial cells for 2 hours, and bacterial gene expression was assessed on a Bacteroides thetaiotaomicron VPI-5482 specific microarray. Forty-three BT genes were up-regulated by five-fold or more and of these, twenty genes encoded hypothetical proteins.
Project description:Analysis of the gut transcriptome as affected by treatment with Bacteroides thetaiotaomicron in a mouse model of IBD Here, we report analysis of the gut transcriptome in IL10KO mice after treatment with Bacteroides thetaiotaomicron (BT). Comparative transcriptome analysis of ascending colon tissue of IL10KO and IL10KO/BT-treated mice showed differential expression of a wide range of genes associated with inflammatory responses between the two treatment groups. Expression of proinflammatory genes and genes involved in pathogen recognition was particularly lower in IL10KO/BT mice.
Project description:Investigation of the overall in vitro response of Bacteroides thetaiotaomicron to human milk oligosaccharides. Comparison with response to MM-lactose and MM-galactose (Analysis performed using as a baseline datasets GSM301635 and GSM301637 corresponding to Bacteroides thetaiotaomicron response in MM-Glucose)
Project description:Investigation of the overall in vitro response of Bacteroides thetaiotaomicron to human milk oligosaccharides. Comparison with response to MM-lactose and MM-galactose (Analysis performed using as a baseline datasets GSM301635 and GSM301637 corresponding to Bacteroides thetaiotaomicron response in MM-Glucose) In vitro transcriptional profiles of Bacteroides thetaiotaomicron obtained from biological duplicate cultures taken: (i) at middle log phase in minimal media galactose (MM-Gal) and minimal media lactose (MM-L) and (ii) at two timepoints during log phase in minimal media human milk oligosaccharides (MM-HMO).
Project description:We report the mid-log phase transcriptional profile of the human gut symbiont Bacteroides thetaiotaomicron, grown in the presence of mouse monoclonal IgAs with species- and strain-level specificity (mAb 260.8 and mAb 225.4, respectively). mRNA expression profiling of the type strain of Bacteroides thetaiotaomicron (NC_004663) grown in vitro in the presence of either (i) PBS (carrier control), (ii) mAb 225.4 alone, (iii) mAb 260.8 alone, (iv) an equal combination of mAbs 225.4 and 260.8, or (v) a nonbinding control mouse mAb IgA (JC63.1)
