Interruption of Signaling-Mediated Bacterial Persistent Infections

中断信号介导的细菌持续感染

• 批准号: 8627544
• 负责人: LAURENCE G RAHME
• 金额: $ 23.92万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8627544
• 关键词: Acinetobacter baumannii; Adopted; Animal Model; Antibiotic Resistance; Antibiotic Therapy; Antibiotics; Bacteria; Bacterial Infections; Benzamides; Biochemical; Biological Assay; Burkholderia; Cell Communication; Cells; Chemicals; Chronic; Clinical; Clinical Research; Coupling; DNA; Data; Development; Drug Combinations; Drug Kinetics; Drug resistance; Effectiveness; Evaluation; Exposure to; Figs - dietary; Future; Gene Expression Alteration; Generations; Goals; Gram-Negative Bacteria; Health; Host Defense; Human; In Vitro; Infection; Inflammatory; Inhibitory Concentration 50; Interruption; Intervention; Klebsiella pneumonia bacterium; Lead; Left; Mediating; Metabolism; Microbial Biofilms; Molecular Weight; Mono-S; Multi-Drug Resistance; Pharmaceutical Preparations; Phase; Population; Population Density; Prevention; Property; Pseudomonas aeruginosa; Publishing; Refractory; Relapse; Relative (related person); Resistance; Ribosomes; Series; Signal Transduction; Signaling Molecule; Structure-Activity Relationship; Testing; Toxicology; Translations; Type I DNA Topoisomerases; Virulence; absorption; antimicrobial; bactericide; benzimidazole analog; improved; in vivo; inhibitor/antagonist; killings; mouse model; mutant; novel; pathogen; preclinical study; prevent; public health relevance; quorum sensing; research study; response; small molecule

DESCRIPTION (provided by applicant): Persistent and chronic infections are often refractory to antibiotics due to antibiotic tolerance of a subpopulation of cells that are not antibiotic resistant mutants, but rather are "dormant" cells that survive antibiotic killing. Our findings sho that Pseudomonas aeruginosa and Burkholderia species excrete a small molecule that serves as a persistence "infochemical" that signals the accumulation of these antibiotic tolerant persister (AT/P) cells and changes that are critical for pathogen adaptation and important for chronic infection. Our aim is to achieve a paradigm shift in persistent infection interventions by introducing a treatment that disrupts the bacterial signaling that induces AT/P cell formation using compounds we have identified; to achieve this aim we will refine and validate lead compounds in vivo, using adapted mouse models of infection. Our approach is fundamentally different from traditional antimicrobial therapies as it specifically targets the AT/P subpopulatio of cells that survive antibiotic treatment (and host defense killing mechanisms), and that are ultimately responsible for persistent and relapsing infections. We propose to develop this approach through experiments employing P. aeruginosa, a recalcitrant Gram-negative bacterium that defies eradication by antibiotics, forms biofilms, and exemplifies current clinicall problematic pathogens. In the R21 phase Aim 1 studies, we will use structure-activity relationship (SAR) data to refine the chemical compositions of the particularly promising 1st generation compounds we have identified. The feasibility of this approach has been established by our prior generation of a series of structurally related agents that block the synthesis of a pr-AT/P signaling molecule and reduce virulence in vivo. In Aim 2, we will perform a series of microbiological, cellular, and biochemical evaluations of the 2nd generation compounds to assess their relative IC50 values and their efficacy against several clinical isolates (including pan-resistant and multi-drug resistant isolates) when used in combination with different classes of antibiotics or alone, as well as their ability to disrupt the synthesis of the signaling molecul and prevent the resultant imbalance in DNA topology and translational effects that we have demonstrated to occur in cells that have transitioned to the AT/P state. The R33 phase (Aims 3 and 4) will be undertaken if our well-defined milestones are achieved. In Aim 3, we will assess the pharmacological efficiency properties of the most promising 2nd generation compounds identified in the R21 phase. In Aim 4, the compounds' efficacies against drug resistant, tolerant pathogens that co-exist with P. aeruginosa in human infections and similarly form AT/P cells (i.e. Acinetobacter baumannii, Klebsiella pneumoniae, and Burkholderia species) will be tested in mono- and polymicrobial planktonic and biofilm settings. Combination drug assays will be performed to determine whether our lead molecules improve antibiotic clearance of biofilms. Highly prioritized advanced leads will then be validated in established mouse models that we have developed. The overall goal of these studies is to carefully assess the potential utility of lead small molecules that target AT/P cells as a new way to intervene against chronic and persistent infections that have thus far been untreatable. These anti-AT/P molecules may be combined with traditional antibiotic therapies for optimal effectiveness.

描述（由申请人提供）：由于不是抗生素突变体的细胞亚群的抗生素耐受性，持续性和慢性感染通常是对抗生素的难治性，而是在抗生素杀死中存活的“休眠”细胞。我们的发现表明，铜绿假单胞菌和Burkholderia物种排泄了一个小分子，它是持久性的“ Inferchemical”，标志着这些抗生素耐受性持久（AT/P）细胞的积累，以及对病原体适应和对慢性感染重要的变化的变化。我们的目的是通过引入一种干扰细菌信号传导来实现持续感染干预措施的范式转移，该治疗使用我们确定的化合物诱导AT/P细胞形成的细菌信号传导；为了实现此目的，我们将使用适应的小鼠感染模型在体内完善并验证铅化合物。我们的方法从根本上与传统的抗菌疗法不同，因为它专门针对生存抗生素治疗（以及宿主防御杀戮机制）的细胞的AT/P亚pp膜，最终导致了持续性和复发感染。我们建议通过采用铜绿假单胞菌的实验来开发这种方法，这是一种顽固的革兰氏阴性细菌，违反了抗生素消除，形成生物膜，并体现了当前的临床临床问题病原体。在R21阶段目标1研究中，我们将使用结构活性关系（SAR）数据来完善我们确定的特别有希望的第一代化合物的化学组成。我们先前的一系列结构相关的药物可以确定这种方法的可行性，这些试剂阻止了PR-AT/P信号分子的合成并降低体内毒力。在AIM 2中，我们将对第二代化合物进行一系列微生物，细胞和生化评估，以评估其相对IC50值及其对几种临床分离株的相对IC50值及其功效（包括抗泛抗和多药抗性分离株）（包括在与不同类别的抗生素或单独的抗生素均匀分析中使用，抗性和多药抗性分离株），并构成抗生素的组合。我们已证明在转换为AT/P状态的细胞中发生的拓扑和翻译效应。如果实现我们定义明确的里程碑，将进行R33阶段（目标3和4）。在AIM 3中，我们将评估R21期最有希望的第二代化合物的药理效率特性。在AIM 4中，对人类感染中与铜绿假单胞菌并存的耐药性病原体的功效和/p细胞类似地形成（即baumannii，klebsiella baumannii，klebsiella pnneumoniae and Burkholdia and thermic and polig and Plancir and plankiry and biobial and biobial and biobial and biobial and biormicrial and biobial and biobial and biobial and-pers and p细胞。将进行联合药物测定，以确定我们的铅分子是否改善了生物膜的抗生素清除率。然后，将在我们开发的已建立的鼠标模型中验证高度优先的高级潜在客户。这些研究的总体目标是仔细评估靶向/p细胞的铅小分子的潜在效用，这是一种干预迄今无法治疗的慢性和持续感染的新方法。这些抗AT/P分子可以与传统的抗生素疗法结合使用，以获得最佳有效性。