摘要

       畜禽粪便的土地利用是一种常见的农业生产方式，它可能导致抗生素抗性基因（ARGs）在环境中的传播和繁殖。然而，长期以来，人们从未系统地比较过施用不同肥料源后农业生态系统中抗性的命运。本文通过土壤微环境培养，比较了添加或不添加泰乐菌素的家禽、牛和猪粪对土壤arg的时间变化的影响。高通量定量PCR共检测到185个独特的ARGs，其中大环内酯类林可酰胺链球菌B耐药是最常见的ARG类型。施用泰乐菌素后，精氨酸的多样性和丰度显著增加，猪粪和禽粪处理的效果比牛粪处理更为显著。随着时间的推移，所有施肥土壤中的抗生素抗性水平逐渐降低，但经过130天培养后，猪粪和家禽粪处理的土壤中的抗生素抗性水平仍然显著高于未处理的土壤。泰乐菌素改良土壤中ARGs的丰度始终高于单纯施用有机肥的土壤，说明抗生素施用有机肥对土壤ARGs的选择压力很大。ARGs的相对丰度与整合酶和转座酶基因显著正相关，表明ARGs在有机肥和泰乐菌素处理土壤中的水平转移潜力。我们的研究结果提供了证据，证明施用猪粪和家禽粪可能比施用牛粪更能丰富土壤中的精氨酸，这就需要在土地施用前对生畜粪进行适当处理，以尽量减少环境精氨酸的传播。

         Land application of animal manure is a common agricultural practice potentially leading to dispersal and propagation of antibiotic resistance genes (ARGs) in environmental settings. However, the fate of resistome in agro-ecosystems over time following application of different manure sources has never been compared systematically. Here, soil microcosm incubation was conducted to compare effects of poultry, cattle and swine manures spiked with or without the antibiotic tylosin on the temporal changes of soil ARGs. The high-throughput quantitative PCR detected a total of 185 unique ARGs, with Macrolide-Lincosamide-Streptogramin B resistance as the most frequently encountered ARG type. The diversity and abundance of ARGs significantly increased following application of manure and manure spiked with tylosin, with more pronounced effects observed in the swine and poultry manure treatments than in the cattle manure treatment. The level of antibiotic resistance gradually decreased over time in all manured soils but was still significantly higher in the soils treated with swine and poultry manures than in the untreated soils after 130 days' incubation. Tylosin-amended soils consistently showed higher abundances of ARGs than soils treated with manure only, suggesting a strong selection pressure of antibiotic-spiked manure on soil ARGs. The relative abundance of ARGs had significantly positive correlations with integrase and transposase genes, indicative of horizontal transfer potential of ARGs in manure and tylosin treated soils. Our findings provide evidence that application of swine and poultry manures might enrich more soil ARGs than cattle manure, which necessitates the appropriate treatment of raw animal manures prior to land application to minimise the spread of environmental ARGs.

         https://www.sciencedirect.com/science/article/pii/S0269749117324491?via%3Dihub