A Novel Therapeutic Agent for the Treatment of Gram-positive Infections

项目摘要 申请中描述的工作对于进一步开发新的 用于治疗革兰氏阳性菌感染的治疗剂。的初步体外和体内活性研究 突变蛋白1140的新类似物表明它们作为抗微生物产品具有很大的前景 临床使用。突变蛋白1140由细菌变形链球菌JH 1140产生， 该细菌已被改造成合成天然化合物的新类似物。我们 研究表明选择的突变蛋白1140类似物具有快速杀菌活性 它们在抑制活性、血清稳定性和 在体内感染研究中的性能。此外，类似物已被证明是更多的 比万古霉素更有效地治疗全身性MRSA感染。突变蛋白1140类似物没有 在50 mg/kg静脉注射剂量下，在小鼠中观察到毒性。此外，还显示了类似物 显著降低急性感染小鼠肾脏和肝脏中MRSA的细菌负荷， 感染研究。所有这些研究都指出，需要进一步的临床前开发的一个或 变异蛋白1140的新类似物进一步研究的主要障碍 对这些独特的抗菌化合物的研究是从培养液中的低产量。的目标 该应用是为了提高发酵后突变蛋白类似物的产率和纯度。三 将探索提高抗菌化合物产率的方法。第一介质 将筛选组分以确定它们对抗菌剂的生产水平的影响。 化合物.其次，将使用基于分子的方法来确定是否增加 在生产类似物是可能的，通过遗传操作的S。变异人我们的第三 方法是转座子或甲基磺酸乙酯（EMS）随机诱变， 下一代DNA测序，以确定导致提高产量的突变。最后一 应用程序的组成部分是确定提取和纯化的最有效手段 发酵液中的抗菌化合物。这些实验将使 探索性研究，用于为研究性新药（IND）研究定义新药产品。

Project Summary The work described in the application is necessary for furthering the development of a new therapeutic for treating Gram-positive infections. Preliminary in vitro and in vivo activity studies of novel analogs of mutacin 1140 suggest that they hold great promise as an antimicrobial product for clinical use. Mutacin 1140 is produced by the bacterium Streptococcus mutans JH1140 and the bacterium has been engineered to synthesize novel analogs of the native compound. Our studies have revealed that select mutacin 1140 analogs have a rapid bactericidal activity and that they are superior to native compound in terms of inhibitory activity, serum stability, and performance in an in vivo infection study. Further, the analogs have been shown to be more effective than vancomycin in treating a systemic MRSA infection. Mutacin 1140 analogs have no observable toxicity in mice at a 50 mg/kg intravenous dose. Furthermore, the analogs were shown to significantly reduce bacterial load of MRSA in the kidneys and liver of infected mice in an acute infection study. All these studies point to the need to further the preclinical development of one or more of the novel analogs of mutacin 1140. The major impediment to furthering investigational studies on these unique antibacterial compounds is the poor yield from culture liquor. The goal of this application is to enhance the yield and purity of mutacin analogs following fermentation. Three approaches will be explored to increase the yield of the antibacterial compound. First, media components will be screened to determine their effect on the production levels of the antibacterial compound. Second, a molecular based approach will be used to determine whether an increase in production of the analogs is possible through genetic manipulation of S. mutans. Our third approach is transposon or ethyl-methanesulfonate (EMS) random mutagenesis coupled with next-generation DNA sequencing to identify mutations that lead to enhanced production. The last component of the application is to determine the most effective means of extracting and purifying the antibacterial compound from the fermentation liquor. These experiments will enable exploratory studies for defining a novel drug product for investigational new drug (IND) studies.