摘要

       动物粪便的土地施用可以改变接收土壤中抗生素抗性细菌 (ARB)、抗生素抗性基因 (ARG) 和细菌群落的分布。本研究采用高通量实时定量 PCR 和 16S rRNA 扩增子测序技术，调查了不同作物（玉米和牧草）和粪便（猪和奶牛）管理下田间土壤中的 ARGs 和细菌群落，并与来自相邻高尔夫球场和草地的两种非施肥参考土壤。在土壤样品中总共发现了 89 种独特的 ARG 亚型，它们通过外排泵、细胞保护和抗生素失活赋予抗性。与高尔夫球场和草地土壤中的 ARG（分别为 28 和 34 个亚型）相比，肥料土壤通常具有更大的 ARG 多样性（36-55 个亚型）。经常接受生猪粪的玉米田土壤具有最大的 ARG 丰度。短期（一周）施用堆肥和液态猪粪增加了玉米田土壤中 ARG 的多样性和总丰度。有趣的是，堆肥猪粪仅略微增加了 ARG 的总丰度，但显着增加了玉米田土壤中 ARG 亚型的数量。网络分析揭示了 ARG 亚型共生模式中的三个主要网络模块，这些主要模块的中心（intl1-1、vanC 和 pncA）可能是选择指示基因以监测粪肥土壤中 ARG 的候选者。 ARGs 和细菌分类群之间的网络分析揭示了检测到的 ARGs 的潜在宿主细菌（例如，氨基糖苷类抗性基因 aacC4 可能主要由酸杆菌科携带）。总体而言，这项研究强调了各种粪便管理对玉米田和牧场土壤中抗生素抗性组和微生物组的潜在影响。

       Land application of animal manure could change the profiles of antibiotic resistant bacteria (ARB), antibiotic resistance genes (ARGs) and bacterial communities in receiving soils. Using high-throughput real-time quantitative PCR and 16S rRNA amplicon sequencing techniques, this study investigated the ARGs and bacterial communities in field soils under various crop (corn and pasture) and manure (swine and dairy) managements, which were compared with those of two non-manured reference soils from adjacent golf course and grassland. In total 89 unique ARG subtypes were found in the soil samples and they conferred resistance via efflux pump, cellular protection and antibiotic deactivation. Compared to the ARGs in the golf course and grassland soils (28 and 34 subtypes respectively), manured soils generally had greater ARG diversity (36–55 subtypes). Cornfield soil frequently receiving raw swine manure had the greatest ARG abundance. The short-term (one week) application of composted and liquid swine manures increased the diversity and total abundance of ARGs in cornfield soils. Intriguingly the composted swine manure only marginally increased the total abundance of ARGs, but substantially increased the number of ARG subtypes in the cornfield soils. The network analysis revealed three major network modules in the co-occurrence patterns of ARG subtypes, and the hubs of these major modules (intl1-1, vanC, and pncA) may be candidates for selecting indicator genes for surveillance of ARGs in manured soils. The network analyses between ARGs and bacteria taxa revealed the potential host bacteria for the detected ARGs (e.g., aminoglycoside resistance gene aacC4 may be mainly carried by Acidobacteriaceae). Overall, this study highlighted the potentially varying impact of various manure management on antibiotic resistome and microbiome in cornfield and pasture soils.

https://www.sciencedirect.com/science/article/abs/pii/S0269749118347754