摘要 

       农场环境中抗生素抗性基因 (ARG) 和移动遗传元件 (MGE) 的共同出现可能会促进抗生素抗性病原体的发展。我们研究了芬兰奶牛场和养猪场的耐药性，在这些农场中，抗生素的使用仅限于治疗细菌感染，而粪便仅在 4 月至 9 月期间使用。从生长季节开始到牧草收获，研究了沟渠中粪便、土壤和瓦片排水的阻力。使用具有 363 对引物的 qPCR 阵列测量相对 ARG 和 MGE 丰度。粪便样品中 ARGs 和 MGEs 的丰度最高，在储存期间增加。土地施用后，立即在土壤中检测到粪便中丰富的 ARG，但它们的丰度随着时间的推移而下降，许多变得无法检测到。这表明施肥后 ARG 丰度的增加是暂时的，并且在限制抗生素使用的农业实践下每年都会发生。在沟渠水中检测到一些 ARG，但在粪便中未检测到大部分 ARG。我们的结果记录了芬兰有限抗生素使用下 ARGs 在农场外的消散和传播，并表明这种做法有助于减少环境中抗生素抗性基因的负荷。

       The co-occurrence of antibiotic-resistance genes (ARGs) and mobile genetic elements (MGEs) in farm environments can potentially foster the development of antibiotic-resistant pathogens. We studied the resistome of Finnish dairy and swine farms where use of antibiotics is limited to treating bacterial infections and manure is only applied from April to September. The resistome of manure, soil, and tile drainage water from the ditch was investigated from the beginning of the growing season until forage harvest. The relative ARG and MGE abundance was measured using a qPCR array with 363 primer pairs. Manure samples had the highest abundance of ARGs and MGEs, which increased during storage. Immediately following land application, the ARGs abundant in manure were detected in soil, but their abundance decreased over time with many becoming undetectable. This suggests that increases in ARG abundances after fertilizing are temporary and occur annually under agricultural practices that restrict antibiotic use. A few of the ARGs were detected in the ditch water, but most of them were undetected in the manure. Our results document the dissipation and dissemination off farm of ARGs under Finnish limited antibiotic use and suggest that such practices could help reduce the load of antibiotic-resistance genes in the environment.

https://pubs.acs.org/doi/abs/10.1021/acs.est.7b00551