Regulation of Multidrug Resistance in the Emerging Human Fungal Pathogen Candida auris

项目摘要/摘要 金黄色念珠菌是一种迅速崛起的人类真菌病原体，可引起全身和粘膜病变 各种免疫受损个体的感染，包括器官移植接受者、癌症 接受化疗的患者和艾滋病患者。C.Auris已经出现在多个大洲，负责 多起医院疫情，粗死亡率高(30%-70%)，已被列为“紧急” 疾病控制中心(CDC)对公共卫生的威胁。许多金黄色葡萄球菌分离物对 多类抗真菌药物，特别是唑类和多烯类，这一点特别令人担忧，因为只有 有三类主要药物可用于治疗念珠菌病患者。以往的研究表明，C. 金黄色葡萄球菌对真菌的耐药性可归因于各种遗传点突变(例如：ERG11突变， 编码羊毛甾醇14α-去甲基酶，氮唑的靶标)以及增加某些药物的转录 外排泵。与遗传和转录机制相比，人们对翻译的了解很少。 控制金黄色葡萄球菌或其他人类真菌病原体抗真菌耐药性的机制。然而，我们的 实验室和其他人的研究表明，5‘非编码区介导的翻译效率机制在翻译效率中发挥着重要作用 在控制几个关键的转录调控因子的表达中的作用，这些转录调控因子包括形态、生物膜的形成、 相关人类主要真菌病原体白色念珠菌的白色不透明切换和毒力。在……里面 此外，rna-seq分析表明，许多基因与各种额外的毒力有关。 白色念珠菌和其他念珠菌的过程，包括抗真菌耐药性，具有长的5‘非编码区 可能参与转化性监管的地区。使用全基因组核糖体图谱，我们有 最近证明，白色念珠菌的酵母-丝状转变受到广泛的翻译控制。 这并不是简单地与基因表达的转录变化平行。几个与基因有关的基因 在这一转变过程中，抗真菌耐药性也显示出翻译效率的改变。重要的是，最近 耐多药金黄色葡萄球菌分离株的转录图谱表明，相当数量的 参与蛋白质合成的基因在抗真菌治疗后表现出变化的表达。基于 在这些观察中，我们假设翻译机制在控制 金黄色葡萄球菌的多药耐药性。为了解决这一假设，我们将：1)确定全基因组 金黄色葡萄球菌对氟康唑(一种常用的唑类)和 多烯类药物两性霉素B，2)鉴定和表征对促进C。 奥里斯多药耐药。最终，这项研究将提供对全球监管电路的更好理解 以及在翻译水平上控制金黄色葡萄球菌多药耐药性的途径。此外，这项研究将 鉴定和鉴定对金黄色葡萄球菌多药具有重要作用的几个关键的翻译调控因子 可能成为开发新的抗真菌策略的目标的抗药性。

PROJECT SUMMARY/ABSTRACT Candida auris is a rapidly emerging human fungal pathogen capable of causing both systemic and mucosal infections in a wide variety of immunocompromised individuals, including organ transplant recipients, cancer patients on chemotherapy and AIDS patients. C. auris has emerged on multiple continents, is responsible for numerous hospital outbreaks and, with a high crude mortality rate (30-70%), has been classified as an “urgent” threat to public health by the Centers for Disease Control (CDC). Many C. auris isolates are highly resistant to multiple classes of antifungals, particularly azoles and polyenes, which is especially concerning given that only three major drug classes are available to treat patients with candidiasis. Previous studies have shown that C. auris antifungal resistance can be attributed to a variety of genetic point mutations (eg: mutations in ERG11, encoding lanosterol 14α-demethylase, the target of azoles) as well as increased transcription of certain drug efflux pumps. In contrast to genetic and transcriptional mechanisms, very little is known about translational mechanisms that control antifungal resistance in C. auris or other human fungal pathogens. However, our laboratory and others, have shown that 5' UTR-mediated translational efficiency mechanisms play an important role in controlling the expression of several key transcriptional regulators of morphology, biofilm formation, white-opaque switching and virulence in the related major human fungal pathogen Candida albicans. In addition, RNA-seq analyses have shown that many genes involved in a variety of additional virulence processes, including antifungal resistance, in C. albicans and other Candida species possess long 5' UTR regions that could be involved in translational regulation. Using genome-wide ribosome profiling, we have recently demonstrated that the C. albicans yeast-filament transition is under widespread translational control that does not simply parallel transcriptional changes in gene expression. Several genes associated with antifungal resistance also showed altered translational efficiency during this transition. Importantly, recent transcriptional profiling of a multidrug resistant C. auris isolate has demonstrated that a significant number of genes involved in protein synthesis show altered expression in response to antifungal treatment. Based on these observations, we hypothesize that translational mechanisms play an important role in controlling multidrug resistance in C. auris. In order to address this hypothesis, we will: 1) determine the genome-wide translational profile of C. auris in response to treatment with fluconazole, a commonly used azole, and the polyene drug amphotericin B, 2) identify and characterize translational mechanisms important for promoting C. auris multidrug resistance. Ultimately, this study will provide a better understanding of global regulatory circuits and pathways that control C. auris multidrug resistance at the translational level. In addition, this study will identify and characterize several key translationally regulated factors important for C. auris multidrug resistance that could potentially serve as targets for the development of novel antifungal strategies.