Malassezia and Candida auris: skin microbiome dysbiosis and de-regulation of cutaneous homeostasis

摘要马拉色菌酵母是一种亲脂性很强的真菌，是温带动物皮肤微生物群中含量最高的真菌。 血腥的动物。除了共生的生活方式外，马拉色菌酵母还与皮肤病有关。 还有血液感染。研究表明，胃肠道中的马拉色菌是克罗恩病的危险因素 CARD9突变患者和潜在的胰腺癌进展患者的疾病，而 肺部的马拉色菌与囊性纤维化的恶化有关。同时，金黄色念珠菌也有 出现在全球范围内，经常产生抗药性，并日益引起医院获得性皮肤 具有严重系统性感染风险、发病率和死亡率高的移民化。朱莉·塞格雷和 同事们开发了一种金黄色念珠菌定植的小鼠模型，并发现人类皮肤 霉菌群失调，可能是由抗生素和抗真菌药物引起的，改变了皮肤的定植 在金黄色念珠菌全身感染之前，马拉色菌为优势种，念珠菌属为优势种。 我们小组和其他人进行的遗传和基因组学研究推动了这项研究的最先进水平 马拉色菌的种类及其与皮肤微生物群和宿主中的细菌和真菌的相互作用。我们 开发了一种根癌农杆菌方法，能够产生随机和有针对性的 两种马拉色菌的突变体，并应用这些工具研究马拉色菌基因的功能及其作用 在药物作用和宿主-病原体相互作用中。我们进行了广泛的基因组分析，贡献了 通过蛋白质组学进行基因组注释并获得完整的端粒-端粒、注释良好的马拉色菌 参考基因组。我们过去对假丝酵母菌的研究确定了钙调神经磷酸酶在全球范围内的保守作用 真菌致病机制，跨念珠菌致病物种复合体的高级基因组学，并有文献记载 白念珠菌与金黄色念珠菌亲缘关系密切，有一个完整的性循环。我们的主要合作伙伴 Salome Leibundgut-Landmann开发了马拉色菌的小鼠皮肤模型，这是这些研究的组成部分。 在这里，我们建议研究马拉色菌和金黄色念珠菌在皮肤生物失调中的相互作用。 微生物群是全身感染的危险因素。在目标1中，我们建议重点研究1)一种新的dsRNA 我们通过产生和研究发现的马拉色菌真菌病毒及其编码的候选蛋白效应物 治愈一种或两种病毒RNA的菌株，以及2)马拉色菌分泌蛋白质(包括过敏原和 通过研究基因缺失突变体和随机插入突变体。在《目标2》中，马拉色西亚 在AIM 1中产生的病毒感染、病毒半治愈和病毒治愈的菌株和突变株将用 体外和体内模型，以确定与金黄色念珠菌和宿主相互作用的分子机制。 建议的研究将推动该领域的发展，为旨在阐明以下问题的研究提供见解 马拉色菌作为皮肤共生体保护人类宿主免受系统性感染的有益作用 由真菌病原体通过竞争性和排他性的皮肤微环境定植。

Abstract Malassezia yeasts are lipophilic and are the most abundant fungi of the skin microbiome of warm- blooded animals. In addition to a commensal lifestyle, Malassezia yeasts are associated with skin diseases and also bloodstream infection. Studies have linked Malassezia in the GI tract as a risk factor for Crohn's Disease in patients with CARD9 mutations and potentially in pancreatic cancer progression, whereas Malassezia in the lung has been linked to Cystic Fibrosis exacerbation. In parallel, Candida auris has emerged globally and is frequently drug-resistant and increasingly causing hospital-acquired skin colonization with significant risk of systemic infection with significant morbidity and mortality. Julie Segre and colleagues have developed a mouse model of Candida auris colonization and found that human skin mycobiome dysbiosis, likely caused by antibiotics and antifungal drugs, shifts skin colonization from Malassezia-dominant to Candida-species dominant patterns prior to Candida auris systemic infections. Genetic and genomics studies from our group and others have advanced the state of the art for the study of Malassezia species and their interactions with bacteria and fungi in the skin microbiome and the host. We developed an Agrobacterium tumefaciens approach enabling generation of both random and targeted mutants of two Malassezia species, and applied these tools to study functions of Malassezia genes with roles in drug action and host-pathogen interactions. We have conducted extensive genomic analysis, contributing genome annotation via proteomics and obtaining complete telomere-telomere, well-annotated Malassezia reference genomes. Our past studies on Candida species defined a globally conserved role of calcineurin in fungal pathogenesis, advanced genomics across the Candida pathogenic species complex, and documented that Candida lusitaniae, closely related to Candida auris, has a complete sexual cycle. Our key collaborator Salome LeibundGut-Landmann has developed a murine skin model for Malassezia integral to these studies. Here we propose to study the interactions of Malassezia with Candida auris in dysbiosis of the skin microbiome as a risk factor for systemic infection. In Aim 1 we propose to focus on 1) a novel dsRNA Malassezia mycovirus we discovered and its encoded candidate protein effector by generating and studying strains cured of either or both viral RNAs, and 2) Malassezia secreted proteins (including allergens and proteases) by studying gene deletion mutants as well as random insertion mutants. In Aim 2, Malassezia virus-infected, virus-semi-cured, and virus-cured strains and mutants generated in Aim 1 will be studied with in vitro and in vivo models to define molecular mechanisms of interactions with Candida auris and the host. The studies proposed will advance the field, providing insights as a foundation for studies aiming to elucidate the beneficial roles Malassezia plays as skin commensals that protect the human host from systemic infection by fungal pathogens through competitive and exclusive colonization of the skin microenvironment.