Combating resistant superbugs by understanding the molecular determinants of target site penetration and binding

通过了解目标位点渗透和结合的分子决定因素来对抗耐药超级细菌

基本信息

批准号：
10449341
负责人：
Jurgen Bernd Bulitta
金额：
$ 106.82万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-10 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10449341
关键词：
Acinetobacter baumannii Antibiotic Therapy Antibiotics Bacteria Binding Biological Assay Blood Circulation Cell Membrane Permeability Cells Chemical Structure Combined Antibiotics Combined Modality Therapy Dangerousness Data Descriptor Dose Folic Acid Antagonists Genetic Engineering Goals Gram-Negative Bacteria Health Healthcare Systems Human Immune system In Vitro Infection Klebsiella pneumoniae Knock-out Lactamase Libraries Measures Membrane Modeling Molecular Morbidity - disease rate Multi-Drug Resistance Multidrug-resistant Acinetobacter Mus Nosocomial Infections Nutrient Patients Penetration Permeability Pharmaceutical Preparations Pharmacology Property Proteomics Pseudomonas aeruginosa Pump Regimen Research Resistance Respiratory System Scheme Series Site Structure Superbug System Time United States Up-Regulation Urinary tract VDAC1 gene Vertebral column World Health Organization base beta-Lactamase beta-Lactams cellular imaging combat combat wound cost design efflux pump extracellular global health improved in vivo inhibitor innovation insight molecular phenotype mortality multidisciplinary novel periplasm predictive modeling prevent prospective receptor receptor binding receptor expression therapeutically effective tool uptake wound

项目摘要

Project Summary/Abstract A severe lack of effective antibiotic treatment options against multidrug-resistant (MDR) Gram-negative bacteria (i.e., “superbugs”) is causing one of the world’s three most serious human health threats. Exacerbating this is a dramatic decline in the number of new antibiotics effective against MDR Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. These “superbugs” cause serious bloodstream, respira- tory and urinary tract, wound, and other infections with very high morbidity and up to 80% mortality. Many antibiotics have extremely poor penetration to their target site, especially in A. baumannii and P. aeruginosa. For these antibiotics, the combination of poor target site penetration and extensive efflux causes the antibiotic concentration at the target site to be over 1,000-fold lower than that of the extracellular antibiotic concentration. Unsurprisingly, many antibiotic candidates fail because of poor penetration to and/or extensive efflux from their bacterial target site. Importantly, there are very substantial gaps in the current understanding of how to maximize the antibiotic target site penetration, avoid efflux from bacterial cells, and thereby maximize receptor binding. This multi-disciplinary project, however, will identify the molecular determinants of how to maximize antibiotic target site concentrations and receptor binding to combat resistant “superbugs”. Our preliminary data and models demonstrate that molecular descriptors can predict the antibiotic target site penetration and effect of multiple efflux pumps in P. aeruginosa. We have developed a series of assays that characterize the penetration of key selected antibiotics to their periplasmic or cytosolic target sites and antibiotic binding to their receptors in intact bacteria. In Aim 1, these new molecular and phenotypic assays will be greatly extended and applied to all three “superbugs”; additionally, a series of isogenic efflux pump knockout strains will be created. The resulting data will uniquely inform novel quantitative models (Aim 2) that can predict penetration, efflux, and thus receptor binding at the bacterial target sites based on molecular antibiotic properties. These models will enable the targeted synthesis of key selected antibiotic probes (Aim 3) that are used to prospectively validate these predictive models. These new probes will serve as the backbone of innovative antibiotic combi- nation dosing strategies that will be rationally optimized via Quantitative and Systems Pharmacology models in Aim 4. Dynamic in vitro and murine infection models with an intact or compromised immune system will then prospectively evaluate these combination regimens. These models can simulate antibiotic concentration-time profiles that mirror those in patients. Overall, this project will provide the molecular insights that enable drug developers to design new antibiotics that achieve high concentrations at their bacterial target site and thereby improve receptor binding. This approach and the targeted new antibiotic probes synthesized in this project hold excellent promise to substantially contribute to combating the three MDR Gram-negative “superbugs”.

项目摘要/摘要严重缺乏针对多药耐药（MDR）革兰氏阴性剂的有效抗生素治疗选择细菌（即“超级细菌”）正在造成世界上三个最严重的人类健康威胁之一。加剧这是针对MDR Acinetobacter Baumannii的新抗生素数量的急剧下降，肺炎和铜绿假单胞菌。这些“超级细菌”引起严重的血液，呼吸保守党和尿路，伤口和其他发病率很高，死亡率高达80％。许多抗生素对目标部位的渗透极差，尤其是在鲍曼尼曲霉和铜绿假单胞菌中。对于这些抗生素，较差的目标部位渗透和广泛的外排的组合引起了抗生素目标部位的浓度比细胞外抗生素浓度低1,000倍以上。毫不奇怪，许多抗生素候选者因渗透不良和/或从其中的大量排出而失败细菌目标部位。重要的是，当前对如何的理解存在很大的差距最大化抗生素靶位点渗透，避免从细菌细胞中排出，从而最大化接收器结合。但是，这个多学科的项目将确定如何最大化的分子决定者抗生素靶位点浓度和受体结合与抗战斗性“超级细菌”。我们的初步数据模型表明，分子描述符可以预测抗生素靶点位点的渗透和效果铜绿假单胞菌中的多个外排泵。我们开发了一系列特征的测定关键选定的抗生素渗透到其外周或胞质靶位点，并与其抗生素结合完整细菌中的受体。在AIM 1中，这些新的分子和表型测定将大大扩展，并且应用于所有三个“超级细菌”；此外，还将创建一系列的等源外排泵敲除菌株。所得数据将唯一地为新颖的定量模型（AIM 2）提供信息，该模型可以预测渗透率，外排，因此，基于分子抗生素特性，受体结合在细菌靶位点上。这些模型将实现关键选定抗生素问题的目标合成（AIM 3），这些抗生素问题用于前瞻性验证这些预测模型。这些新问题将成为创新抗生素组合的骨干国家给药策略将通过定量和系统药理学模型合理优化 AIM 4。具有完整或受损的免疫系统的体外和鼠感染模型将前瞻性评估这些组合方案。这些模型可以模拟抗生素浓度时间图谱反映了患者中的那些。总体而言，该项目将提供启用药物的分子见解开发人员设计新的抗生素，可在其细菌靶位点上获得高浓度改善接收器结合。这种方法和该项目中合成的有针对性的新抗生素探针极大的希望有助于与三个MDR革兰氏阴（Superbugs）作斗争。