A novel Probiotic for Preventing and Treating Clostridium Difficile Pathogenesis

Project Summary The goal of this project is to develop a novel drugRfor the prevention and or treatment of ClostridiumCdifficile pathogenesisRis based on a unique protein known as secreted antigen ASagAidentified from Enterococcus faecium which our research team showed can protect against multiple enteric infectionsincluding Cdifficileby enhancing the integrity of the gut membrane barrierCdifficile is a ubiquitous anaerobic Gram positive bacterium that can sporulate and become highly resistant to environment stresses and frontline antibiotics such as clindamycinPathogenic strains of Cdifficile secret toxinsA and Bthat damage intestinal epithelial cellsresulting in inflammatory colitissevere diarrheaabdominal painflu like symptomsand possible deathCdifficile infectionCDIoften occurs following antibiotic treatment when the endogenous microflora of individuals is altered or severely reducedSincethe rate of CDI has increased from belowto overcases and has been become one of the most significant hospital acquired infections with an economic burden of over $billion to treat in the USAOnce Cdifficile establishes residence in the colonit is difficult to eradicate with last resort antibioticsvancomycinand consequently results in relapses of CDI and inflammatory colitisAn effective approach to treating CDI has been fecal microbiota transplantFMTtherapyHoweverFMT is a heterogeneous and poorly defined therapeuticfor which its safety is still a major concern requiring special FDA approvalNew and well defined therapeutics are desperately needed to prevent and treat CDIDefined strains of probiotics offer an exciting alternative to prevent and treat CDI and many strains of Lactobacillusacidophiluscaseireuteriplantarumhave been explored as probiotics to inhibit infection of enteric pathogens and mitigate antibiotic associated diarrheaUnfortunatelythe mechanism of action has been difficult to characterize with limiting beneficial effects in the context of their clinical utilityWhile more clinical studies are still neededthese recent studies suggest that improved probiotics may be even more effective at controlling CDIIndeedour recent results published in the journal Science demonstrate that engineering orreprogrammingof probiotics to recombinantly express SagA yields a more protective functionality against enteric infectionsincluding CDIOur goal is to develop a novel probiotic strain to deliver SagAreferred to as Ras an orally administered drug that functions naturally to induce protective regulatory signalsThe key objectives are togenerate Llactis clones expressing SagA from a genomeintegrated operonselect a Rclinical candidate based on growth rateSagA expressionand stabilityanddemonstrate Ractivity in the murine Cdifficile infection modelSuccessful commercialization of Rwill ultimately provide a profound front line medical advancement in the treatment of enteric infection Project Narrative Clostridium difficile infectionsCDIis one of the most significant hospital acquired infections affectingpeople in the USA annually with a cost over $billion per year to treatIn our prior murine in vivo studiessecreted antigen ASagAa protein expressed in Enterococcus faecium that can cleave bacterial cell wall components to enhance host resistance to enteric pathogenscould protect against Salmonella typhimurium and CDI pathogenesisThis project aims to develop a novel drugRwhich would provide a profound front line prevention and or treatment of CDI