Genetic determinants of bacterial-drug synergy against Candida

住院患者中的细菌感染仍然是一个重要的未解决的临床问题， 据估计，美国和欧洲每年有23万人死亡。两种最重要的机会性病原体 是真菌白色念珠菌和革兰氏阴性细菌铜绿假单胞菌。他们是 在通气患者和囊性纤维化患者中经常共同分离，其中共同关联与加重 疾病这两种机会性感染的药物治疗往往是有问题的，我们假设， 这些失败中的一些是由于在共培养期间微生物-微生物和微生物-免疫相互作用的影响， 感染拟议的研究旨在解决我们理解中的这一重大差距，以确定是否存在 合并感染的复杂性要求对治疗策略有不同的看法。 我们的总体目标是了解假单胞菌-念珠菌相互作用如何影响毒力和治疗效果， 成功我们最近发现，抗真菌药物氟康唑（FLC）是更有效和杀真菌 针对C.在铜绿假单胞菌的存在下，在体外和体内的白色念珠菌。在这份提案中，我们的驾驶 假设是特定细菌毒力因子阻断真菌对FLC的耐受性。我们假设铁 饥饿和钙调神经磷酸酶信号是这种协同作用的两个关键因素，这也是基于我们的初步数据 如已发表的将铁稳态和钙调神经磷酸酶与药物耐受性联系起来的工作。利用 斑马鱼的活体成像与微生物基因组学一起将使我们能够对细菌进行遗传分析， 真菌在治疗和感染的背景下。我们建议发现新的细菌和真菌贡献者 铜绿假单胞菌-FLC协同抗C.白念珠菌通过互补候选基因/无偏倚 体外筛选策略（目的1）。然后，我们将利用真菌、细菌和 透明斑马鱼的先天免疫细胞，以测试这些机制和先天免疫细胞的相关性。 在脊椎动物宿主中共感染期间对真菌治疗的免疫贡献（目的2）。 这些拟议研究的结果将产生一个细菌和真菌途径的网络， 体内调节药物敏感性。这一建议有可能为我们研究如何 感染期间细菌和真菌之间的交流调节药物敏感性。虽然这是一个基本的 科学研究的建议，将揭示新的跨王国的相互作用，在感染，重点是 抗真菌治疗也具有为未来的转化研究提供信息的巨大潜力。

Opportunistic infections in hospitalized patients remain an important unsolved clinical problem, leading to an estimated 230,000 annual deaths in the US and Europe. Two of the most important opportunistic pathogens are the fungus Candida albicans and the gram-negative bacterium Pseudomonas aeruginosa. They are frequently co-isolated in ventilated patients and in cystic fibrosis, where co-association is linked to exacerbated disease. Drug treatment of these two opportunistic infections is often problematic, and we hypothesize that some of these failures are due to the impact of microbe-microbe and microbe-immune interactions during co- infection. The proposed research seeks to address this major gap in our understanding to define whether the complexity of co-infection demands a different view of therapeutic strategy. Our overall goal is to understand how Pseudomonas-Candida interactions affect virulence and therapeutic success. We recently found that the antifungal drug fluconazole (FLC) is much more effective and fungicidal against C. albicans in the presence of P. aeruginosa, both in vitro and in vivo. In this proposal, our driving hypothesis is that specific bacterial virulence factors block fungal tolerance to FLC. We hypothesize that iron starvation and calcineurin signaling are two key elements in this synergy, based on our preliminary data as well as published work connecting iron homeostasis and calcineurin to drug tolerance. Leveraging the power of intravital imaging in zebrafish together with microbial genomics will enable our genetic analyses of bacteria and fungi in the context of treatment and infection. We propose to uncover novel bacterial and fungal contributors to P. aeruginosa-FLC synergy against C. albicans through a complementary candidate gene/unbiased screening strategy in vitro (Aim 1). We will then utilize longitudinal intravital imaging of fungi, bacteria, and innate immune cells in the transparent zebrafish to test the relevance of these mechanisms and the innate immune contributions to fungal therapy during co-infection in the vertebrate host (Aim 2). The findings from these proposed studies will yield a network of bacterial and fungal pathways that operate in vivo to regulate drug susceptibility. This proposal has the potential to open up a new front in our study of how communication between bacteria and fungi during infection regulates drug susceptibility. While this is a basic science research proposal that will reveal new cross-kingdom interactions during infection, the focus on antifungal treatment also has significant potential for informing future translational research.