Project description:The intestines house a diverse microbiota that must compete for nutrients to survive, but the specific limiting nutrients that control pathogen colonization are not clearly defined. Clostridioides difficile colonization typically requires prior disruption of the microbiota, suggesting that outcompeting commensals for resources is key in establishing C. difficile infection (CDI). The immune protein calprotectin (CP) is released into the gut lumen during CDI to chelate zinc (Zn) and other essential nutrient metals. Yet, the impact of Zn limitation on C. difficile colonization is unknown. To define C. difficile responses to Zn limitation, we performed RNA sequencing on C. difficile exposed to CP. In media with CP, C. difficile upregulated genes involved in metal homeostasis and amino acid metabolism.
Project description:To reveal the effects of deleting the Δxtr gene in Clostridioides difficile, we first constructed a Δxtr knockout mutant and then examined the resulting phenotypic changes. Finally, to elucidate the underlying mechanisms, we performed RNA-sequencing-based transcriptome analysis.
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: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 is one of the most common nosocomial pathogens and a global public health threat. Upon colonization of the gastrointestinal tract, C. difficile is exposed to a rapidly changing polymicrobial environment and a dynamic metabolic milieu. Despite the link between the gut microbiota and susceptibility to C. difficile, the impact of synergistic interactions between the microbiota and pathogens on the outcome of infection is largely unknown. Here, we show that microbial cooperation between C. difficile and Enterococcus has a profound impact on the growth, metabolism, and pathogenesis of C. difficile.. Through a process of nutrient restriction and metabolite cross-feeding, E. faecalis shapes the metabolic environment in the gut to enhance C. difficile fitness and increase toxin production. These findings demonstrate that members of the microbiota, such as Enterococcus, have a previously unappreciated impact on C. difficile behavior and virulence.
Project description:The Clostridioides difficile toxins TcdA and TcdB are responsible for diarrhea and colitis. The aim of this project was to explore the effects of the toxins on epithelial barrier function and the molecular mechanisms for diarrhea and inflammation. RNA-seq of toxin-treated intestinal cell monolayers was performed to describe the C. difficile-mediated effects. mRNA profiles from intestinale epithelial cells were generated by deep sequencing using Illumina NovaSeq 6000. This data provide the basis for subsequent upstream regulator analysis.
Project description:Clostridioides difficile infection (CDI), caused by strains producing toxin B (TcdB), poses a significant global health threat. While C. difficile exhibits substantial diversity, functional studies have focused on a limited number of isolates, overlooking other genomospecies within the genus. We describe five isolates from patients suspected of having CDI who tested negative for the PaLoc marker gene tcdC. Through genomic, proteomic, and phenotypic analyses, we demonstrate that they correspond to three novel toxin-producing species, designated as Clostridioides cryptodifficilis sp. nov., Clostridioides divergens sp. nov., and Clostridioides subdifficilis sp. nov. These species are distinguished by unique MALDI-ToF signatures, metabolic capabilities, and genomic and proteomic architectures, underscoring their clear taxonomic and functional divergence from C. difficile. They secrete functionally active TcdB7 or TcdB11, as demonstrated by cytotoxicity assays in cultured cells and in vivo using the mouse ileal loop model, implicating them in disease pathology, albeit with lower virulence than C. difficile. Our findings expand the known diversity of TcdB-producing Clostridioides and have direct implications for diagnostics, surveillance, and clinical management of diarrheal diseases.
Project description:Clostridioides difficile infection (CDI), caused by strains producing toxin B (TcdB), poses a significant global health threat. While C. difficile exhibits substantial diversity, functional studies have focused on a limited number of isolates, overlooking other genomospecies within the genus. We describe five isolates from patients suspected of having CDI who tested negative for the PaLoc marker gene tcdC. Through genomic, proteomic, and phenotypic analyses, we demonstrate that they correspond to three novel toxin-producing species, designated as Clostridioides cryptodifficilis sp. nov., Clostridioides divergens sp. nov., and Clostridioides subdifficilis sp. nov. These species are distinguished by unique MALDI-ToF signatures, metabolic capabilities, and genomic and proteomic architectures, underscoring their clear taxonomic and functional divergence from C. difficile. They secrete functionally active TcdB7 or TcdB11, as demonstrated by cytotoxicity assays in cultured cells and in vivo using the mouse ileal loop model, implicating them in disease pathology, albeit with lower virulence than C. difficile. Our findings expand the known diversity of TcdB-producing Clostridioides and have direct implications for diagnostics, surveillance, and clinical management of diarrheal diseases.
Project description:The experiment intends to reveal the difference in gene expression profiles between the wild-type strain and the ∆rpoN mutant of Clostridioides difficile. We first constructed the ∆rpoN mutant, and the phenotypic changes of the ∆rpoN mutant against the wild-type strain were studied. To further elucidate the mechanism of phenotypic changes of the ∆rpoN mutant, RNA-sequencing experiments were carried out to reveal the underlying mechanism of phenotypic changes.
Project description:The experiment intends to reveal the difference in gene expression profiles between the wild-type strain and the ∆cwp66 mutant of Clostridioides difficile. We first constructed the ∆cwp66 mutant, and the phenotypic changes of the ∆cwp66 mutant against the wild-type strain were studied. To further elucidate the mechanism of phenotypic changes of the ∆cwp66 mutant, RNA-sequencing experiments were carried out to reveal the underlying mechanism of phenotypic changes.