Project description:Clostridioides difficile interactions with the gut mucosa are crucial for colonisation and establishment of infection, however key infection events during the establishment of disease are still poorly defined. To better understand the initial events that occur during C. difficile colonisation, we employed a dual RNA-sequencing approach to study the host and bacterial transcriptomic profiles during C. difficile infection in a dual-environment in vitro human gut model. Temporal changes in gene expression were analysed over 3-24h post infection and comparisons were made with uninfected controls.
Project description:Clostridioides difficile can cause severe infections in the gastrointestinal tract and affects almost half a million people in the U.S every year. Upon establishment of infection, a strong immune response is induced. We sought to investigate the dynamics of the mucosal host response during C. difficile infection.
Project description:We illustrate how metabolically distinct species of Clostridia can protect against or worsen Clostridioides difficile infection, modulating the pathogen's colonization, growth, and virulence to impact host survival. Gnotobiotic mice colonized with the amino acid fermenter Paraclostridium bifermentans survived infection while mice colonized with the butyrate-producer, Clostridium sardiniense, more rapidly succumbed. Systematic in vivo analyses revealed how each commensal altered the gut nutrient environment, modulating the pathogen's metabolism, regulatory networks, and toxin production. Oral administration of P. bifermentans rescued conventional mice from lethal C. difficile infection via mechanisms identified in specifically colonized mice. Our findings lay the foundation for mechanistically informed therapies to counter C. difficile disease using systems biologic approaches to define host-commensal-pathogen interactions in vivo.
Project description:Clostridioides difficile (C. difficile) is a common cause of antibiotic-induced diarrhea and causes the highest number of nosocomial infections. Only two antibiotics are currently recommended for treating C. difficile infection (CDI), which may contribute to unsatisfactory treatment outcomes and an increased likelihood of recurrence. In this study, we aim to evaluate the difference in gene expression between symptomatic and asymptomatic mice after infection with C. difficile using spatial transcriptomics analysis. We also aim to evaluate the spatial aspect of altered genes between different layers of intestinal mucosa (superficial vs deep) and identify the key pathways. Formalin-fixed paraffin-embedded (FFPE) intestinal sections were utilized for analysis using NanoStringTM platform to evaluate differential gene expressions in the caecum and colon. The IL-17 pathway, including Lcn2, Cxcl2, and S100a8 genes, was significantly upregulated in symptomatic mice. The IL-17 signaling pathway activated downstream signaling through NF-κB and MAPK pathways. Gene expression was significantly altered between the intestinal superficial and deep mucosal layers, highlighting layer-specific differences in gene expression patterns in the intestines of symptomatic and asymptomatic mice. Gene expression patterns in the enteric mucosa explained several clinical signs and lesions in CDI mice.
Project description:We defined global differences in transcriptome profiles between mice inoculated with toxin mutant strains of Clostridioides difficile. These data were mined to study differences in expression of ion transporters that may be implicated in diarrhea during disease.
Project description:Background: Clostridioides difficile (C. difficile) is a global threat and has significant implications for individuals and health care systems. Little is known about host molecular mechanisms and transcriptional changes in peripheral immune cells. This is the first gene expression study in whole blood of patients with C. difficile infection. Methods: We took blood and stool samples from patients with toxigenic C. difficile infection (CDI), non-toxigenic C. difficile infection (GDH), inflammatory bowel disease (IBD), diarrhoea from other causes (DC) and healthy controls (HC). We performed transcriptome-wide RNA profiling on peripheral blood to identify diarrhoea common and CDI unique gene sets. Results: Diarrhoea groups upregulated innate immune responses with neutrophils at the epicentre. The common signature associated with diarrhoea was non-specific and shared by various other inflammatory conditions. CDI had a unique 45-gene set reflecting downregulation of humoral and T cell memory functions. Dysregulation of immunometabolic genes was also abundant and linked to immune cell fate during differentiation. Conclusions: Whole transcriptome analysis of white cells in blood from patients with toxigenic C. difficile infection showed that there is an impairment of adaptive immunity and immunometabolism.
Project description:<p>Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea that seriously threaten public health. Disruption of normal gut microbiota by the use of broad-spectrum antimicrobial agents enables C. difficile to proliferate in the colon. The emergence and prevalence of hypervirulent C. difficile strains result in increased morbidity, mortality and recurrence rates of CDI, thus creating a pressing need for novel therapeutics. The multi-domain toxins TcdA and TcdB are the primary determinant of CDI pathogenesis, renders them ideal drug targets in the anti-virulence paradigm. In this study, we identified caffeic acid and its derivatives as active inhibitors of TcdB via a cell-based high-throughput phenotypic screening. Further mechanistic investigations revealed that caffeic acid phenethyl ester (CAPE) could directly bind to TcdB, thus suppressing InsP6-induced autoproteolysis and inhibiting the glucosyltransferase activity. CAPE-treatment remarkably reduces the pathology of CDI in a murine infection model in terms of alleviated diarrhea symptom, decreased bacterial colonization and relieved histopathological lesions. Moreover, CAPE-treatment of C. difficile-challenged mice induces remarkable increase in the diversity and composition of the gut microbiota (e.g. Bacteroides) and alterations of gut metabolites (e.g. adenosine, D-proline and melatonin), which might partially contribute to the therapeutic outcomes of CAPE against CDI. Our results reveal the potential of CAPE as a therapeutic for the management of CDI, or CAPE might be served as a lead compound for the development of anti-virulence drug targeting TcdB.</p>
Project description:Gene expression level of Clostridioides difficile (C. difficile) strain R20291 comparing control C. difficile carring pMTL84151 as vector plasmid with C. difficile conjugated with a pMTL84151-03890 gene. Goal was to determine the effects of 03890 gene conjugation on C. difficile strain R20291 gene expression.
Project description:Systems biology approach of Clostridioides difficile to analyze the temporal changes in the intracellular and extracellular metabolme, transcriptome and proteome along the growth curve in casamino acids medium and the connection to toxin production.
