Generation of novel drugs against drug resistant bacteria through engineering of

描述（由申请人提供）：近年来，接受抗生素耐药细菌感染治疗的患者数量急剧增加。最初的问题主要与医院获得性肠球菌感染有关，不仅已经进入一般社区，而且还发展到包括一些广泛和严重的病原体。耐药链球菌、葡萄球菌、肠球菌和假单胞菌菌株相当常见。目前，在美国，多达70%的医院获得性感染对至少一种抗生素具有耐药性，约40%的S。金黄色葡萄球菌感染具有多重耐药性。即使像万古霉素和替考拉宁这样的药物，多年来代表了治疗耐药性感染的“最后手段”，也不再对某些病原体菌株有效。这些化合物的功效丧失使得患有多重耐药感染的患者的治疗选择非常少。显然，对具有新作用模式的新抗生素存在迫切的未满足的需求。此外，抗菌药物的整体市场很大，而且还在不断增长，2006年全球销售额达到300亿美元。早期发表的数据表明，恩培肽素，一种由嗜盐稳杆菌产生的环状肽，在体外对广泛的革兰氏阳性生物体具有相当大的效力。该数据还表明，该化合物在小鼠中耐受良好，并且对金黄色葡萄球菌、化脓性链球菌和肺炎链球菌的全身感染非常有效。然而，尽管早在20多年前就被发现，但empedopeptin尚未被开发成商业产品。最近，对empedopeptin的体外评价显示，该化合物对大多数当代的耐药革兰氏阳性微生物（包括耐甲氧西林的S.金黄色葡萄球菌（MRSA）、甲氧西林耐药的S.表皮（MRSE）和万古霉素耐药肠球菌（VRE）。与已发表的动物数据一起，这表明empedopeptin可能具有开发成用于治疗由今天的抗真菌药物引起的感染的药物所需的特性。然而，缺乏专利保护以及对几种病原体的MIC值有点高，目前构成了该化合物开发的障碍。本提案中概述的项目的总体目标是使用基因工程方法产生抗菌化合物empedopeptin的新型衍生物。这将允许改善化合物的治疗性质，以及创造与化合物作为用于治疗抗生素抗性细菌感染的药物的商业开发相容的知识产权情况。然而，任何基因工程介导的恩培肽素结构修饰的绝对先决条件是相应的（目前未知的）生物合成基因的可用性。因此，第一阶段的目标是鉴定、分离和表征该基因。公共卫生相关性：在过去的二十年中，多重耐药感染的急剧增加已经产生了对具有新作用模式的新抗菌药物的未满足的需求。拟议项目将为目前相当有限的化合物库存增加一种强效、有效、耐受性良好和经济的抗菌药物，对广泛的临床相关耐药和多重耐药革兰氏阳性病原体有效。

DESCRIPTION (provided by applicant): The number of patients treated for antibiotics-resistant bacterial infections has increased drastically in recent years. What started as a problem primarily associated with hospital-acquired Enterococcus infections, has not only moved into the general community, but also grown to include a number of widespread and serious pathogens. Drug-resistant Streptococci, Staphylococci, Enterococci and Pseudomonas strains are quite common. Currently as many as 70% of hospital-acquired infections in the US are resistant to at least one antibiotic, and about 40% of S. aureus infections are multidrug-resistant. Even drugs like Vancomycin and Teicoplanin, which for years represented the "agents of last resort" for treatment of antibiotics-resistant infections, are no longer efficacious against certain pathogen strains. The loss of efficacy of these compounds leaves very few treatment options for patients with multi-drug resistant infections. Clearly, there is an immediate unmet need for new antibiotics with novel modes of action. Moreover, the overall market for antibacterial drugs is large and growing - world-wide sales reached $30 billion in 2006. Early published data suggest that empedopeptin, a cyclic peptide produced by Empedobacter haloabium, has considerable potency towards a wide range of Gram positive organisms, in vitro. This data also suggest that the compound is well tolerated in mice and quite efficacious against systemic infections of Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae. Nonetheless, although discovered over 20 years ago, empedopeptin has not been developed into a commercial product. A recent, in vitro evaluation of empedopeptin has revealed that the compound also has significant potency against most contemporary, drug-resistant, Gram-positive organisms, including meticillin-resistant S. aureus (MRSA), meticillin-resistant S. epidermis (MRSE) and vancomycin-resistant Enterococci (VRE). Together with the published animal data, this suggests that empedopeptin may have the properties required for development into a drug for the treatment of infections caused by today's antibiotics-resistant organisms. However, a lack of patent protection together and somewhat high MIC values towards several pathogens currently constitutes a barrier to development of the compound. The overall goal of the project outlined in this proposal is to use of a genetic engineering approach to generate novel derivatives of the antibacterial compound empedopeptin. This will allow improvement of the compound's therapeutic properties, as well as creation of an intellectual property situation that is compatible with commercial development of the compound as a drug for the treatment of antibiotics-resistant bacterial infections. However, an absolute prerequisite for any genetic engineering-mediated structural modifications of empedopeptin is availability of the corresponding (currently unknown) biosynthesis gene. Consequently, the goal of Phase I is to identify, isolate and characterize this gene. PUBLIC HEALTH RELEVANCE: The drastic increase in multi-drug resistant infections, during last two decades, has generated an immediate unmet need for new antibacterial drugs with novel modes of action. The proposed project will add a potent, efficacious, well-tolerated and economical antibacterial drug to a currently quite limited inventory of compounds with efficacy towards a broad range of clinically relevant drug- and multi-drug resistant Gram-positive pathogens.