Effects of Agricultural Fungicide Use on Aspergillus fumigatus Abundance, Antifungal Susceptibility, and Population Structure.
Effects of Agricultural Fungicide Use on Aspergillus fumigatus Abundance, Antifungal Susceptibility, and Population Structure.
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DOI：
10.1128/mbio.02213-20
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发表时间：
2020-11-24
期刊：
影响因子：
6.4
通讯作者：
Kurzai O
中科院分区：
文献类型：
--
作者：
Barber AE;Riedel J;Sae-Ong T;Kang K;Brabetz W;Panagiotou G;Deising HB;Kurzai O
抗生素耐药性对人类健康构成越来越大的威胁。烟曲霉是一种环境真菌，也会对人类造成危及生命的感染，农业中使用杀菌剂可能会产生抗菌素耐药性，因为用于植物保护的化学品与临床使用的抗真菌剂几乎相同。然而，从农田中去除唑类杀菌剂会导致产量下降，从而威胁到全球粮食供应。在这项研究中，我们调查了施用杀菌剂之前和之后的农田。我们发现农业分离株的总体唑类抗性率较低，并且使用杀菌剂后缺乏基因组和群体影响，这使我们得出结论，作物上使用唑类不会显着导致烟曲霉的抗性。抗生素耐药性对人类健康构成越来越大的威胁。烟曲霉既是一种环境腐生菌，又是一种机会性人类真菌病原体，农业中使用杀菌剂可能会产生耐药性，因为用于植物保护的唑类药物与临床使用的一线抗真菌药物具有相同的分子靶点。然而，限制唑类杀菌剂在农田中的使用以保持其临床使用活性可能会导致产量下降，从而威胁全球粮食供应。在这项研究中，我们通过对德国农场进行系统的土壤采样以及在施用杀菌剂之前和之后对田地进行调查，阐明了农田中唑类杀菌剂的使用与典型人类病原体的抗性之间的联系。我们观察到 2017 年经过杀菌剂处理后田间烟曲霉的丰度有所减少，这一发现在仅施用天然植物保护剂的有机对照田地中未观察到。然而，这一发现在我们 2018 年的采样中不太明显，表明杀菌剂对烟曲霉种群规模的影响是可变的，并且受到其他因素的影响。农业菌株总体耐药频率较低，2016年至2018年仅有1%至3%的菌株对医用唑类表现出耐药性。生长季节和唑类暴露后收集的分离株显示出对医用和农业唑类的敏感性微妙但持续的降低。全基因组测序表明，尽管抗真菌药敏性发生改变，但杀菌剂的使用并没有显着影响田间烟曲霉的种群结构和遗传多样性。鉴于农业分离株中观察到的耐药率较低，以及唑类施用后缺乏基因组影响，我们没有发现证据表明作物上使用唑类会显着推动烟曲霉的耐药性。
Antibiotic resistance is an increasing threat to human health. In the case of Aspergillus fumigatus, which is an environmental fungus that also causes life-threatening infections in humans, antimicrobial resistance is suggested to arise from fungicide use in agriculture, as the chemicals used for plant protection are almost identical to the antifungals used clinically. However, removing azole fungicides from crop fields threatens the global food supply via a reduction in yield. In this study, we survey crop fields before and after fungicide application. We find a low overall azole resistance rate among agricultural isolates, as well as a lack of genomic and population impact following fungicide application, leading us to conclude azole use on crops does not significantly contribute to resistance in A. fumigatus. Antibiotic resistance is an increasing threat to human health. In the case of Aspergillus fumigatus, which is both an environmental saprobe and an opportunistic human fungal pathogen, resistance is suggested to arise from fungicide use in agriculture, as the azoles used for plant protection share the same molecular target as the frontline antifungals used clinically. However, limiting azole fungicide use on crop fields to preserve their activity for clinical use could threaten the global food supply via a reduction in yield. In this study, we clarify the link between azole fungicide use on crop fields and resistance in a prototypical human pathogen through systematic soil sampling on farms in Germany and surveying fields before and after fungicide application. We observed a reduction in the abundance of A. fumigatus on fields following fungicide treatment in 2017, a finding that was not observed on an organic control field with only natural plant protection agents applied. However, this finding was less pronounced during our 2018 sampling, indicating that the impact of fungicides on A. fumigatus population size is variable and influenced by additional factors. The overall resistance frequency among agricultural isolates is low, with only 1 to 3% of isolates from 2016 to 2018 displaying resistance to medical azoles. Isolates collected after the growing season and azole exposure show a subtle but consistent decrease in susceptibility to medical and agricultural azoles. Whole-genome sequencing indicates that, despite the alterations in antifungal susceptibility, fungicide application does not significantly affect the population structure and genetic diversity of A. fumigatus in fields. Given the low observed resistance rate among agricultural isolates as well the lack of genomic impact following azole application, we do not find evidence that azole use on crops is significantly driving resistance in A. fumigatus in this context.