TARGETABLE BACTERICIDAL PROTEINS TO SPECIFICALLY KILL CLOSTRIDIUM DIFFICILE BACTE

描述（由申请人提供）：本申请和任何后续II期申请的最终目标是开发一种独特的蛋白制剂，以预防高风险患者的艰难梭菌相关疾病，而不是等待治疗其危险和昂贵的感染。在这个SBIR一期项目中，我们的目标是确定口服递送铅的可行性，特异性靶向杀菌蛋白，以消除艰难梭菌运输，而不会对肠道微生物群造成意外的附带损害。主要候选药物被称为“扩散素”，可杀死28株BI/NAP1/027菌株中的27株；和Lawley等人（2010）描述了艰难梭菌携带的小鼠模型。我们最近的研究表明，另一种经过改造的r型细菌素口服给兔，可以通过胃肠道作为一种特定的杀菌剂，杀死回肠末端和结肠中的另一种细菌病原体。因此，在提高该铅重组蛋白在枯草芽孢杆菌中的实验室规模生产，并进行初步的药理学和药效学研究以指导给药后，我们将评估diffocins对C57Bl/6小鼠的疗效，C57Bl/6小鼠是一种难辨梭菌敏感菌株的无症状携带者和脱落者。如果diococins消除了携带艰难梭菌的小鼠体内的艰难梭菌，那么口服diococins对小鼠肠道微生物群的影响将通过diococins给药后正常小鼠和艰难梭菌携带小鼠粪便微生物组的核分型来确定。

DESCRIPTION (provided by applicant): The ultimate goal of this proposal and any subsequent phase II proposal is to develop a unique protein agent to prevent Clostridium difficile associated diseases in those patients at high risk rather than wait to treat their dangerous and costly infections. We aim in this SBIR phase I project to determine the feasibility of oral delivery of a lead, specifically targeted bactericidal protein to eliminate C. difficile cariage without untended collateral damage to the intestinal microbiota. The lead candidate, termed a "diffocin", kills 27 of a collection of 28 BI/NAP1/027 strains; and Lawley et al (2010) have described a mouse model of C. difficile carriage. We have recently shown that another engineered R-type bacteriocin administered orally to rabbits can transit the GI tract to act as a specific bactericidal agent killing another bacterial pathogen in the terminal ileum and colon. Thus, after improving the lab scale production of this lead recombinant protein in B. subtilis and conducting preliminary pharmacology and pharmacodynamic studies to guide dosing, we shall evaluate the efficacy of diffocins in C57Bl/6 mice that are asymptomatic carriers and shedders of a sensitive strain of C. difficile. If diffocins eliminate C. difficile from carrier mice, the efect of oral diffocins on the mouse intestinal microbiota will be determined by ribotyping the fecal microbiome of normal and C. difficile carrier mice after diffocin administration.