Mucin-degrading microflora for prophylactic antibiotics

描述(由申请人提供)：这项重新提交的第一阶段SBIR申请专注于开发一种粘蛋白降解的结肠菌群，竞争性地排除艰难梭菌，艰难梭菌是一种革兰氏阳性厌氧菌，会导致从轻度腹泻到严重的伪膜性结肠炎等抗生素相关肠道疾病。我们的目标是艰难梭菌，因为这种病原体在美国已经是一个主要的医疗问题，每年有超过30万例病例，复发率接近20%。如果进行大规模的抗菌药预防，将会有更多的人高度容易感染艰难梭菌。艰难梭菌也可以通过基因操作来表达其他毒素，如选择剂、epsilon和肉毒杆菌毒素。以前的研究表明，球状梭菌群的成员降解和利用粘蛋白，并竞争性地将艰难梭菌排除在肠道之外。在目标1中，我们将确定和表征来自球虫类群的粘蛋白降解菌群的潜在成员。我们将确定最有效地代谢粘蛋白的球菌素组成员。将建立顶级粘蛋白降解菌的生长和维护程序。在目标2中，我们将确定一种粘蛋白降解菌的体外和体内表现特征。该菌群将在抗生素相关性腹泻和结肠炎的仓鼠模型中进行保护和治疗效果的评估。将对有效菌群的成员进行筛选，以确定是否存在可转移的抗生素耐药基因和毒素基因。在第二阶段，我们的研究将扩展到在GMP下产生粘蛋白降解菌群，并在杜克大学肯尼思·威尔逊博士的指导下启动对该菌群的临床研究。我们的目标是确定粘蛋白降解菌是否恢复或保留了正常的粘蛋白代谢，增强了对艰难梭菌定植的抵抗力，并减少了艰难梭菌引起的抗生素相关性腹泻的发生率。

DESCRIPTION (provided by applicant): This resubmitted Phase I SBIR application focuses on the development of a mucin-degrading colonic flora that competitively excludes Clostridium difficile, a gram-positive anaerobe that causes antibiotic-associated intestinal disease ranging from mild diarrhea to life-theatening pseudomembranous colitis. We are targeting C. difficile because this pathogen already is a major healthcare problem in the U.S., with over 300,000 cases per year and a relapse rate approaching 20%. In the event of massive antimicrobial prophylaxis, there will be a much larger population highly susceptible to infection with C. difficile. C. difficile also could be genetically manipulated to express other toxins such as the select agents, epsilon and botulinum toxins. Previous studies have shown that members of the Clostridium coccoides group degrade and utilize mucin, and competitively exclude C. difficile from the intestine. In Aim 1, we will identify and characterize potential members of a mucin-degrading flora from the coccoides group. We will identify the coccoides group members that most effectively metabolize mucins. The growth and maintenance procedures for the top mucin-degrading strains will be established. In Aim 2, we will determine the in vitro and in vivo performance characteristics of a mucin-degrading flora. The flora will be evaluated for protection and treatment efficacy in the hamster model of antibiotic-associated diarrhea and colitis. Members of an effective flora will be screened for the absence of transferable antibiotic resistance genes and toxin genes. In Phase 2, our studies will be extended to produce the mucin-degrading flora under GMP and initiate clinical studies with the flora under the direction of Dr. Kenneth Wilson at Duke University. Our goal is to determine if the mucin-degrading flora restores or preserves normal mucin metabolism, enhances resistance to colonization by C. difficile, and reduces the incidence of C. difficile- induced antibiotic-associated diarrhea.