Determining the origins of Candida auris from experimental, epidemiological and ecological investigations

真菌对人类健康的威胁越来越大。随着病原体产生耐药性，人类的许多真菌疾病也越来越难以用抗真菌药物治疗。耳念珠菌最近已成为一种人类多重耐药病原体，可在住院患者中引起严重疾病。遗传学研究已经证实，金黄色葡萄球菌包括多达五个基因不同的种群。然而，尚不清楚金黄色葡萄球菌是何时何地进化的，以及它在“溢出”到人类种群之前占据了什么样的生态位。使用实验和系统发育的方法相结合，该项目试图回答C. auris的进化起源。在鱼类中发现了金黄色葡萄球菌的近亲，这表明该分支可能是在水生环境中进化而来的，可能是作为其他鱼类的殖民者或病原体。此外，金黄色葡萄球菌能够在非常高的温度和高盐浓度下生长。该项目将从全基因组序列数据中探索祖先和进化历史，以及C. auris在鳉鱼的卵和胚胎中定居的能力：这是埃克塞特大学开发的一种新的实验系统，专注于自然发现于温暖的亚热带和热带浅水中的物种。

Fungi are a growing threat to the health of humans. Many fungal diseases of humans are also becoming increasingly difficult to treat with antifungals as pathogens evolve resistance. Candida auris has recently emerged as a multidrug-resistant pathogen of humans that causes severe illness in hospitalised patients. Genetic studies have confirmed C. auris includes as many as five genetically divergent populations. However, it is unknown when and where C. auris evolved, and what ecological niche(s) it occupied before 'spilling over' in to human populations. Using a combination of experimental and phylogenetic approaches, this project seeks to answer the evolutionary origins of C. auris. The closest relatives of C. auris have been found in fish, suggesting the clade may have evolved in an aquatic environment, possibly as a coloniser or pathogen of other fish. Furthermore, C. auris is able to grow at very high temperates and in high salt concentrations. The project will explore ancestral and evolutionary history from whole genome sequence data, as well as the ability of C. auris to colonise the eggs and embryos of Killifish: a new experimental system developed at the University of Exeter that focusses on a species naturally found in shallow warm subtropical and tropical waters.