土壤-作物系统中杀菌剂诱导的烟曲霉（Aspergillus fumigatus）对抗真菌药物抗药性：形成与机制

Invasive aspergillosis is a fungal disease caused by Aspergillus fumigatus that primarily affects immunocompromised patients. Azole resistance in Aspergillus becomes a growing public health menace. The resistance in Aspergillus fumigatus to medical azoles might link to farm fungicides. The characteristics, resistant mechanisms and recovered sensitivity of resistant Aspergillus fumigatus in soil and on the surface of crops will be investigated in this project. To explore the relationship between the development of the resistance and the application of fungicide in agriculture, the dependence of resistant Aspergillus fumigatus on fungicide application will be studied as well. The transfer of resistant Aspergillus fumigatus from soil to plant will be monitored to assess the possible origin of the resistance in the human pathogen.

烟曲霉（Aspergillus fumigatus）是重要的机会致病菌，唑类抗真菌药物是治疗侵染性曲霉病的主要药物。然而，一个严峻的现实是烟曲霉对唑类抗真菌药物存在严重的抗药性且呈普遍蔓延之势，烟曲霉抗药性是否来源于农用杀菌剂使用是近年关注的热点问题。本项目针对农田土壤-作物系统中抗唑类抗真菌药物烟曲霉的形成机制和抗性机制及其在土壤-作物间的传播等问题，研究：1）杀菌剂施药水平和频率与抗性菌形成关系；2）农田环境中抗唑类抗真菌药物烟曲霉的普遍性；3）抗性烟曲霉的抗性机制；4）抗性烟曲霉的回复敏感性；5）抗性烟曲霉在土壤-作物系统中的迁移性。阐明唑类杀菌剂使用诱导烟曲霉产生对唑类抗真菌药物抗药性的机制，揭示抗性烟曲霉由农田环境通过食物链进入人体的可能性，并从农药应用角度提出克服烟曲霉产生抗药性的途径，为烟曲霉抗药性的认识和克服提供新思路。

项目分离、鉴定了土壤中唑类杀菌剂-唑类抗真菌药物交叉抗性烟曲霉、抗药性烟曲霉的抗性机制、抗药性烟曲霉的回复敏感性、杀菌剂使用诱导土壤中烟曲霉产生抗药性的可能性。结果发现：农田土壤和城市医院周边土壤中烟曲霉分布广泛并存在抗药性菌株，抗药性菌株cyp51A突变方式有TR46/Y12F/T289A、L98H/ S297T/F495I、G448S等；戊唑醇等三唑类杀菌剂可诱导烟曲霉TR46/Y12F/T289A、P222Q、G138S、G448S等抗药性相关cyp51A突变，导致烟曲霉抗药性；烟曲霉cyp51A的TR46/Y12F/T289A突变直接导致其抗药性，也增强cyp51A表达；cyp51A TR46/Y12F/T289A突变菌株抗药性可稳定遗传；灭菌唑诱导土壤中烟曲霉抗药性与其浓度相关。