Characterization and suppression of resistance to new CRE agents

摘要 我是一名传染病药剂师，渴望从事致力于翻译的学术生涯 安全有效的抗菌策略的科学发现，以预防和治疗由 抗药性病原体。我最近被提升为该大学的医学副教授 在匹兹堡，我在尼尔·克兰西博士、阮宏博士和拉曼·文卡塔拉曼博士的实验室接受过培训 目的：研究抗菌药物的耐药性及药代动力学-药效学。正在做 因此，我学习了基本和先进的实验室技术，并寻求NIH的职业发展资金。 作为K08奖获得者，我现在提交R03资金申请，以提供新的初步数据 以及支持后续R01应用的假设。 拟议项目的目标是：1)了解科索沃保护团-- 产生肺炎克雷伯菌(KPC-KP)的临床分离株对新批准的抗生素产生耐药性， 头孢他啶-阿维巴坦(CAZ-AVI)和美罗培南-瓦博巴坦(Mer-VAB)，以及2)确定 有效抑制阻力的出现。KPC-KP感染仍然是发病的主要原因。 以及患者的死亡率。最近头孢他啶-阿维巴坦治疗的有效性有所改善 KPC-KP感染患者的转归，但代价是在一些患者中出现耐药性 案子。我们预计，CAZ-AVI和Mer-AVI通过不同的分子机制产生耐药性。 VAB是基于菌株的遗传特性而产生的。这项提议的中心假设是 CAZ-AVI或Mer-VAB与协同抗生素联合应用将抑制AVI或Mer-VAB的出现 单独接触任何一种制剂后出现抗药性。 为了验证这一假设，我们将比较KPC-KP突变率与CAZ-AVI和Mer-AVI的突变率。 VAB，并确定了介导抗性产生的机制。我们将筛选抗生素 使用可能与CAZ具有协同作用机制的抗生素进行时间-杀灭分析的组合- AVI和/或Mer-VAB(目标1)。接下来，我们将验证有效的组合根除KPC-KP的能力 并在体外中空纤维感染中抑制10天疗程内耐药性的出现 准确模拟人性化抗生素暴露的模型(目标2)。该型号具有特定于站点的特点 在感染部位实现的暴露，我们将根据这些数据开发数学模型来定义 最佳组合。通过这些目标，我们将产生及时的、与临床相关的数据，这些数据无法 通过其他方式获得，并将为今后的赠款申请开辟新的调查渠道。我是 在一个医疗中心内很好地实现拟议的目标，该中心积累了大量 CAZ-AVI的世界经验和研究环境使我能够开发先进的 研究抗菌素耐药性所需的实验室和分析技能。

ABSTRACT I am an infectious diseases pharmacist who aspires to pursue an academic career devoted to translating scientific discoveries into safe and effective antimicrobial strategies to prevent and treat infections caused by drug-resistant pathogens. I have recently been promoted to Associate Professor of Medicine at the University of Pittsburgh, where I have trained in the labs of Drs. Neil Clancy, Hong Nguyen, and Raman Venkataramanan to study antimicrobial resistance and the pharmacokinetics-pharmacodynamics of antibacterial drugs. In doing so, I have learned basic and advanced laboratory techniques and pursued NIH career development funding. As a K08 award recipient, I am now submitting an application for R03 funding to provide new preliminary data and hypotheses in support of a subsequent R01 application. The goals of the proposed project are to 1) understand the frequency and mechanisms by which KPC- producing Klebsiella pneumoniae (KPC-Kp) clinical isolates develop resistance to newly-approved antibiotics, ceftazidime-avibactam (CAZ-AVI) and meropenem-vaborbactam (MER-VAB), and 2) identify strategies that effectively suppress the emergence of resistance. KPC-Kp infections continue to be a major cause of morbidity and mortality among patients. The recent availability of ceftazidime-avibactam treatment has improved outcomes among KPC-Kp infected patients, but has come at the cost of the emergence of resistance in some cases. We anticipate that resistance emerges through distinct molecular mechanisms for CAZ-AVI and MER- VAB based upon the genetic characteristics of isolates. The central hypothesis of this proposal is that combination regimens of CAZ-AVI or MER-VAB with synergistic antibiotics will suppress the emergence of resistance seen following exposures to either agent alone. To test this hypothesis, we will compare the KPC-Kp mutational frequency rates against CAZ-AVI and MER- VAB, and determine mechanisms mediating the emergence of resistance. We will screen antibiotic combinations by time-kill analysis using antibiotics that may have synergistic mechanisms of action with CAZ- AVI and/or MER-VAB (aim 1). Next, we will validate effective combinations for their ability to eradicate KPC-Kp and suppress the emergence of resistance over a 10-day treatment course in an in vitro hollow-fiber infection model that accurately simulates humanized exposures of antibiotics (aim 2). The model features site-specific exposures that are achieved at sites of infection, from which we will develop mathematical models to define the best combinations. Through these objectives, we will generate timely, clinically-relevant data that cannot be obtained through other approaches, and will open new lines of investigation for future grant applications. I am well-positioned to carry out the proposed aims within a medical center that has accumulated much of the world's experience with CAZ-AVI and a research environment that has allowed me to develop the advanced laboratory and analytical skills needed to study antimicrobial resistance.