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: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.
Project description:Tolerance is a major defense strategy against infection. During the host response to pathogens, tolerance restricts inflammatory damage to tissues, maintaining the long-term integrity of organs. The mechanisms that establish tolerance are poorly understood. We analyzed pulmonary isolates of Pseudomonas aeruginosa that evolved to coexist with tolerant hosts and found that these opportunistic pathogens facilitate tolerance by stimulating ketogenesis. Ketone body production in the airway limits the accumulation of detrimental factors that injure the lung, such as inflammatory cytokines and effector phagocytes. Although ketones are typically synthesized in the liver, in situ metabolo-transcriptomic studies revealed that P. aeruginosa drives their generation in the lung by co-opting the metabolism of alveolar macrophages, which are pulmonary cells of hepatic origin. This phenomenon was restricted to clinical isolates and not observed with laboratory strains of P. aeruginosa , confirming the unique metabolo-tolerogenic properties of ESKAPE pathogens adapted to the human lung.
