Aspergillus fumigatus Volatile Secondary Metabolite Dynamics for the Identification of Azole-resistant Aspergillosis

烟曲霉挥发性次生代谢动态用于鉴定唑类抗性曲霉病

• 批准号: 9299327
• 负责人: Sophia Koo
• 金额: $ 25.63万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9299327
• 关键词: Agriculture; Allergic Bronchopulmonary Aspergillosis; Anabolism; Antifungal Agents; Antifungal Therapy; Asia; Aspergillosis; Aspergillus; Aspergillus fumigatus; Attenuated; Azole resistance; Azoles; Biological Assay; Breath Tests; Breathing; Cell Death; Cessation of life; Chronic; Clinical; Consensus; Cytochrome P450; Data; Detection; Development; Diagnostic Procedure; Diagnostic tests; Early identification; Environment; Ergosterol; Europe; Explosion; Failure; Fungal Drug Resistance; Gas Chromatography; Geographic Distribution; Growth; Guidelines; Immune system; Immunocompromised Host; In Vitro; Incidence; Industrial fungicide; Infection; Itraconazole; Lanosterol; Lung; Medical; Metabolic; Methods; Modeling; Morbidity - disease rate; Mus; Mutation; Nephrotoxic; Patients; Pharmaceutical Preparations; Phenotype; Polyenes; Reporting; Resistance; Risk; Risk Factors; Sesquiterpenes; Soil; Spectrometry; Structure; Testing; Therapeutic; Time; Toxic effect; Triazoles; Voriconazole; Water; Work; attenuation; base; clinical risk; experimental study; fungus; in vivo; mortality; nephrotoxicity; novel; pressure; resistance mechanism; response; soil sampling; tandem mass spectrometry

Project Summary/Abstract: Invasive aspergillosis (IA) is a leading cause of morbidity and death in immunocompromised patients, with over 200,000 cases worldwide per year. While advances in diagnostic testing for IA and the development of potent, less toxic triazole antifungal drugs have reduced IA-associated mortality from 68% to 25%, an alarming rise in the incidence and geographic distribution of azole-resistant Aspergillus fumigatus (ARAF) over the past decade is steadily offsetting these gains and compromising the use of triazole antifungal drugs as first-line therapy for IA. The major culprit in the rapid explosion of ARAF in the environment and in patient lungs appears to be the increasing global use of azole fungicides similar in structure to medical triazoles in agriculture worldwide, especially in Europe and Asia – these fungicides persist in the soil and water for months, applying widespread, systematic selection pressure favoring the emergence of ARAF, which in turn spreads quickly through vegetative growth and abundant dissemination of airborne conidia. ARAF is now responsible for up to 30% of IA cases in Europe with associated mortality of 70-100%, with steadily rising incidence elsewhere in the world. Managing patients with ARAF IA is incredibly challenging due to the lack of clinical risk factors, lack of diagnostic methods that can differentiate ARAF IA from azole-susceptible IA in a timely manner, and the need to employ antifungals with substantially lower efficacy and greater toxicity than the azole drugs. We have developed methods of identifying patients with IA via detection of Aspergillus volatile sesquiterpene secondary metabolites in breath, and of examining in vivo responses to antifungal treatment via serial assessment of these fungal breath metabolites over the course of antifungal therapy. In contrast to the attenuation of secondary metabolite release in azole- susceptible A. fumigatus with azole antifungal treatment, these metabolites instead increase in ARAF with azole exposure. We will test the hypothesis that the sesquiterpene secondary metabolite response to triazole antifungal therapy is distinct in azole-susceptible and azole-resistant A. fumigatus by (1) comparing the in vitro response of ARAF (including the most common cyp51A mutations TR34/L98H, TR46/Y121F/T289A, M220, and G54, and ARAF with phenotypic multi-azole resistance despite wild-type cyp51A) and azole-susceptible A. fumigatus strains to azole antifungal therapy and (2) comparing the in vivo response of ARAF and azole-susceptible A. fumigatus to azole antifungal therapy in breath using a neutropenic murine IA model. Ultimately, we expect to delineate marked differences in the dynamics of volatile sesquiterpene secondary metabolite release in ARAF vs. azole- susceptible A. fumigatus, both in vitro and in vivo. Successful completion of these aims would set the groundwork for a novel, rapid breath assay that can distinguish patients with ARAF IA from azole-susceptible IA, providing an in vivo indicator of imminent therapeutic failure, guiding selection of appropriate antifungal therapy, and reducing the extremely high morbidity and mortality associated with ARAF IA.

项目摘要/摘要：侵袭性曲霉病 (IA) 是导致发病和死亡的主要原因 免疫功能低下的患者，全世界每年有超过 200,000 例病例。虽然诊断测试取得了进步 强效、毒性较小的三唑类抗真菌药物的开发降低了 IA 相关死亡率 68% 至 25%，耐唑类烟曲霉的发病率和地理分布呈惊人上升趋势 （ARAF）在过去十年中正在稳步抵消这些成果并损害三唑类抗真菌药物的使用 作为 IA 的一线治疗。 ARAF在环境和患者体内迅速爆发的罪魁祸首 肺部似乎越来越多地使用结构与医用三唑类似的唑类杀菌剂 全世界的农业，尤其是欧洲和亚洲——这些杀菌剂在土壤和水中持续数月， 施加广泛的、系统的选择压力，有利于 ARAF 的出现，从而迅速传播 通过营养生长和空气中分生孢子的大量传播。 ARAF 现在负责高达 30% 欧洲 IA 病例的相关死亡率为 70-100%，而世界其他地区的发病率稳步上升。 由于缺乏临床危险因素、缺乏诊断方法，管理 ARAF IA 患者非常具有挑战性。 及时区分 ARAF IA 和唑敏感 IA 的方法，以及需要采用 与唑类药物相比，抗真菌药的功效明显较低，毒性较大。 我们已经开发出方法 通过检测呼吸中的曲霉菌挥发性倍半萜次生代谢物来识别 IA 患者， 以及通过对这些真菌呼吸代谢物的连续评估来检查抗真菌治疗的体内反应 在抗真菌治疗过程中。与唑类中次生代谢物释放的减弱相反 使用唑类抗真菌治疗易感烟曲霉，这些代谢物反而会增加唑类药物的 ARAF 接触。我们将检验以下假设：倍半萜次级代谢产物对三唑类抗真菌药物的反应 通过（1）比较以下药物的体外反应，治疗对唑类敏感和唑类耐药的烟曲霉的治疗是不同的： ARAF（包括最常见的 cyp51A 突变 TR34/L98H、TR46/Y121F/T289A、M220 和 G54，以及 ARAF 尽管野生型 cyp51A) 和对唑类敏感的烟曲霉菌株仍具有表型多唑类抗性 唑类抗真菌治疗和（2）比较 ARAF 和唑类敏感烟曲霉的体内反应 使用中性粒细胞减少的小鼠 IA 模型进行唑类抗真菌呼吸治疗。最终，我们希望描绘出 ARAF 与唑类中挥发性倍半萜次生代谢物释放动力学存在显着差异 在体外和体内均对烟曲霉敏感。成功完成这些目标将确定 为一种新型快速呼吸检测奠定了基础，该检测可以区分 ARAF IA 患者和唑类敏感患者 IA，提供即将治疗失败的体内指标，指导选择适当的抗真菌药物 治疗，并降低与 ARAF IA 相关的极高发病率和死亡率。