Novel Strategies for Antibiotic Combinations to Combat Gram-negative Superbugs

项目摘要/摘要：耐碳青霉烯类肠杆菌科（CRE）已被归类为 美国和地球仪的紧急公共卫生威胁。新德里金属β-内酰胺酶（NDM） 生产CRE特别令人关注，因为它们在世界范围内迅速蔓延，可以有效地共同 存在过多的革兰氏阴性耐药决定簇，包括超广谱β-内酰胺酶 （ESBLs）、碳青霉烯酶和多粘菌素抗性基因。我们报告了美国第一例 多粘菌素和碳青霉烯类耐药E.产新德里金属β-内酰胺酶（NDM-5）的大肠杆菌 以及患者中的移动的粘菌素抗性（MCR-1）。泛耐药（PDR）的最新报道， K.肺炎（NDM-1，ESBLs和多粘菌素耐药决定簇），来自内华达州的患者，进一步 强调，这可能只是一个时间问题，直到医院在美国和世界各地面临爆发的 这些革兰氏阴性菌“超级细菌”为将来发生的NDM准备治疗药物至关重要 具有多种抗性决定子的菌株。我们的中心假设是， 优化的抗生素组合给药策略将实现广泛的杀灭，并防止出现 对产NDM肠球菌的耐药性。我们的初步研究提供了 支持我们创新组合的证据。我们建立了第一个高效的盒式检测试剂盒 评估β-内酰胺在多粘菌素存在下的靶部位渗透，这是关于β-内酰胺的第一个数据集 K.肺炎，并显示新的4种药物联合方案根除了NDM， 产ESBL菌株K.肺炎并防止耐药性。在目标1中，我们将从基因上创造 工程菌株，以及评估β-内酰胺抗生素的靶位点渗透和受体结合 和β-内酰胺酶抑制剂，以及在多粘菌素存在下增强的渗透。在目标2中，体外 药代动力学/药效学模型，包括动态中空纤维感染模型，将 通过分析细菌感染的时间过程，评估3种和4种药物组合的优化给药策略 杀戮，镇压抵抗，消灭顽固分子。基因组学和转录组学将用于 了解为什么单一疗法和非优化组合失败的耐药性。在Aim 3中，我们最新的 定量和系统药理学（QSP）建模方法将指导所有 实验层这些新的最佳组合给药策略的前瞻性验证将在 在具有完整和受损免疫系统的鼠肺炎模型中完成。这将产生 针对泛耐药CRE的创新联合给药方案，可抑制耐药性。 因此，该项目将解决全球迫切的医疗需求。该项目将提供第一个 机制上知情，合理优化和前瞻性验证的组合给药策略， 这些抗生素将用于未来的临床试验。

Project Summary/Abstract: Carbapenem-Resistant Enterobacteriaceae (CRE) have been classified as an urgent public health threat in the US and around the globe. New Delhi Metallo-β-lactamases (NDM) producing CRE are particularly concerning as they have rapidly spread worldwide and can efficiently co- exist with a plethora of Gram-negative resistance determinants including Extended Spectrum β-lactamases (ESBLs), carbapenemases, and polymyxin resistance genes. We have reported the first US case of polymyxin- and carbapenem-resistant E. coli producing New Delhi Metallo-beta-lactamase (NDM-5) together with mobile colistin resistance (MCR-1) in a patient. The recent report of pan-drug-resistant (PDR), K. pneumoniae (NDM-1, ESBLs, and polymyxin resistance determinants), from a patient in Nevada further highlights that it may be only a matter of time until hospitals in the US and worldwide face an outbreak of these Gram-negative ‘superbugs’. It is critical to prepare therapeutics for the future occurrence of NDM strains which harbor a diverse array of resistance determinants. Our Central Hypothesis is that rationally optimized antibiotic combination dosing strategies will achieve extensive killing and prevent emergence of resistance against of NDM-producing Enterobactericeae. Our preliminary studies provide compelling evidence in support of our innovative combinations. We established the first highly efficient cassette assay to assess target site penetration of β-lactams in the presence of polymyxins, the first dataset on β-lactam receptor binding in K. pneumoniae, and show that new 4-drug combination regimens eradicated NDM and ESBL co-producing K. pneumoniae and prevented resistance. In Aim 1, we will create genetically engineered strains, as well as assess the target site penetration and receptor binding of β-lactam antibiotics and β-lactamase inhibitors, and the enhanced penetration in presence of polymyxins. In Aim 2, in vitro pharmacokinetic/pharmacodynamics models, including the dynamic Hollow Fiber Infection Model, will evaluate optimized dosing strategies for 3- and 4-drug combinations by profiling the time course of bacterial killing, suppression of resistance, and persister eradication. Genomics and transcriptomics will be utilized to understand why monotherapies and non-optimized combinations failed with resistance. In Aim 3, our latest Quantitative and Systems Pharmacology (QSP) modelling approach will guide translation across all experimental tiers. Prospective validation of these novel optimal combination dosing strategies will be completed in murine pneumonia models with an intact and impaired immune system. This will yield innovative combination dosage regimens against pandrug-resistant CRE that can suppress resistance. Thus, this project will address an urgent, global medical need. This project will provide the first mechanistically informed, rationally optimized and prospectively validated combination dosing strategies of available antibiotics against resistant Gram-negatives that will be ready for testing in future clinical trials.