Heteroresistance Interdisciplinary Research Unit (Project 2)

异阻性跨学科研究单元（项目2）

• 批准号: 10366038
• 负责人: DAVID S WEISS
• 金额: $ 35.85万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-05 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10366038
• 关键词: Acinetobacter baumannii; Affect; Antibiotic Resistance; Antibiotics; Bacteria; Bacterial Infections; Biology; Cells; Cessation of life; Citric Acid Cycle; Clinic; Clinical; Clinical Trials; Complement; Confusion; Diffusion; Enterobacter; Enterobacteriaceae; Europe; Exhibits; Formulation; Fosfomycin; Foundations; Gene Amplification; Genetic; Glucose; Glutamates; Glutathione; Guidelines; Heterogeneity; Infection; Interdisciplinary Study; Intermediate resistance; Intervention; Intravenous; Life; Malignant Neoplasms; Mediating; Medical; Metabolic; Modeling; Modern Medicine; Mus; Mutation; Operative Surgical Procedures; Oral; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Population; Predisposition; Prevalence; Prevalence Study; Process; Repression; Research Project Grants; Resistance; Risk; Role; Safety; Savings; Shunt Device; Signal Transduction; Testing; Time; Transplantation; Treatment Failure; Treatment outcome; Urinary tract infection; Work; alpha ketoglutarate; antibiotic resistant infections; bacterial resistance; carbapenem-resistant Enterobacteriaceae; chemotherapy; clinical diagnostics; combat; design; drug development; experimental study; human disease; improved; in vivo; insight; member; metabolic phenotype; metabolomics; mortality; non-genetic; novel; novel strategies; novel therapeutic intervention; novel therapeutics; pathogen; resistance mechanism; sugar; surveillance data

ABSTRACT Antibiotic resistance is one of the most serious medical challenges of our time. This crisis puts patients at risk of untreatable bacterial infections and threatens major advances of modern medicine that rely on antibiotics (transplants, chemotherapy, etc). There are at least 2.8 million antibiotic resistant infections each year in the US, leading to over 35,000 deaths [1]. Without significant action, worldwide annual mortality due to these infections is predicted to reach 10 million by 2050, surpassing that predicted for cancer [2]. Understanding resistance mechanisms is critical to designing novel approaches and therapeutics to combat resistant bacteria. Heteroresistance (HR) is an enigmatic form of antibiotic resistance in which a bacterial isolate harbors a resistant subpopulation that can rapidly replicate in the presence of an antibiotic, while a susceptible subpopulation is killed [3, 4]. We have observed HR to the antibiotic, fosfomycin, which is a member of its own drug class and has primarily been used in the US in an oral form to treat urinary tract infections (UTIs) [5]. The use of fosfomycin has recently increased as bacteria become resistant to other classes of drugs [6] and due to its strong safety profile. Due to its increased need and expected expanded approval for IV use, fosfomycin is expected to become a much more prominent part of the antibiotic arsenal in the US. Therefore, it is essential that we elucidate the biology of fosfomycin resistance to guide clinical use. Strikingly, our surveillance data revealed that the rate of fosfomycin HR among carbapenem-resistant Enterobacteriaceae (CRE; 72%) and Acinetobacter baumannii (CRAB; 89%) was higher than that of any other antibiotic tested, and that a large proportion was not detected by clinical diagnostics [7]. We recently demonstrated that HR to diverse antibiotics, including fosfomycin, can cause treatment failure in vivo [4]. Interestingly, and thus far unique among studied examples of HR, we found that fosfomycin HR is caused by two distinct, co-existing resistant subpopulations, both of which replicate in the presence of drug and are not persisters, but form resistant small (R-SM) or large (R-LG) colonies. Results from a transposon screen and metabolomic experiments revealed the underlying basis for the R-SM and R-LG cells to be metabolic heterogeneity, rather than unstable genetic changes such as gene amplification. We will dissect how metabolic signaling drives the expansion of the resistant R-SM subpopulation and the roles of glutamate and glutathione in this process. We will then study the prevalence of distinct fosfomycin resistant subpopulations among diverse clinical isolates. This work will have a sustained and powerful impact on our understanding of non- genetic mechanisms of HR and metabolic and phenotypic heterogeneity. This will complement Project 1 which focuses on unstable genetic mechanisms of HR. The new and fundamental insights gained will lay the foundation for the discovery of novel therapeutics and interventions targeting subpopulations to reduce human disease.

抽象的 抗生素耐药性是我们这个时代最严峻的医学挑战之一。这场危机使患者处于危险之中 无法治疗的细菌感染，并威胁到依赖抗生素的现代医学的重大进步 （移植、化疗等）。每年至少有 280 万抗生素耐药感染者 美国，导致超过 35,000 人死亡[1]。如果不采取重大行动，全球每年都会因这些原因死亡 预计到 2050 年，感染人数将达到 1000 万，超过癌症的预测 [2]。理解 耐药机制对于设计对抗耐药细菌的新方法和疗法至关重要。 异抗性 (HR) 是抗生素耐药性的一种神秘形式，其中细菌分离株具有 耐药亚群可以在抗生素存在下快速复制，而易感亚群 亚群被杀死 [3, 4]。我们观察了抗生素磷霉素的 HR，它是其自身的成员 药物类别，在美国主要以口服形式用于治疗尿路感染 (UTI) [5]。这 由于细菌对其他类别的药物产生抗药性，磷霉素的使用最近有所增加 [6]，并且由于 其强大的安全性。由于其需求的增加和预期静脉注射用途的批准扩大， 磷霉素预计将成为美国抗生素库中更加重要的组成部分。 因此，我们有必要阐明磷霉素耐药的生物学原理以指导临床使用。 引人注目的是，我们的监测数据显示，碳青霉烯类耐药人群中磷霉素 HR 的比率 肠杆菌科 (CRE; 72%) 和鲍曼不动杆菌 (CRAB; 89%) 高于任何其他细菌 抗生素进行了测试，并且很大一部分未被临床诊断检测到[7]。我们最近 证明对包括磷霉素在内的多种抗生素的HR可导致体内治疗失败[4]。 有趣的是，迄今为止在 HR 研究的例子中是独一无二的，我们发现磷霉素 HR 是由 两个不同的、共存的耐药亚群，两者都在药物存在的情况下复制，并且不存在 持续存在，但形成抗性小（R-SM）或大（R-LG）菌落。转座子筛选的结果和 代谢组学实验揭示了 R-SM 和 R-LG 细胞代谢的根本基础 异质性，而不是不稳定的遗传变化，例如基因扩增。我们将剖析新陈代谢如何 信号传导驱动耐药 R-SM 亚群的扩张以及谷氨酸和谷胱甘肽的作用 在这个过程中。然后我们将研究不同磷霉素耐药亚群的患病率 不同的临床分离株。这项工作将对我们对非 HR 以及代谢和表型异质性的遗传机制。这将补充项目 1，其中 专注于HR不稳定的遗传机制。获得的新的基本见解将奠定 发现针对亚人群的新疗法和干预措施的基础 减少人类疾病。