Mucin-degrading microflora for prophylactic antibiotics

描述（由申请人提供）：该重新提交的I期SBIR申请侧重于开发一种可降解黏液的结肠菌群，可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，可导致从轻度腹泻到延长生命的假膜性结肠炎等抗生素相关肠道疾病。我们之所以瞄准艰难梭菌，是因为这种病原体已经成为美国的一个主要医疗问题，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素预防，将会有更多的人群极易感染艰难梭菌。艰难梭菌也可以通过基因操纵来表达其他毒素，如select agents， epsilon和肉毒杆菌毒素。先前的研究表明，球芽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Aim 1中，我们将从球虫群中识别和表征黏液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虫组成员。建立顶级黏液降解菌株的生长和维持程序。在目标2中，我们将确定黏液降解菌群的体外和体内性能特征。该菌群将在抗生素相关性腹泻和结肠炎仓鼠模型中评估其保护和治疗效果。有效菌群的成员将被筛选为缺乏可转移的抗生素抗性基因和毒素基因。在第二阶段，我们的研究将扩展到生产GMP下的黏液降解菌群，并在杜克大学Kenneth Wilson博士的指导下开始临床研究。我们的目的是确定黏液降解菌群是否恢复或保持正常的黏液代谢，增强对艰难梭菌定殖的抵抗力，并减少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.