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: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 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.
