摘要
      动物生产对抗生素耐药性基因（ARGs）在环境中的传播有很大贡献。嗜热堆肥在减少动物粪便危害方面具有成本效益。然而，ARGs仍然可以在堆肥中持续存在，其机制在很大程度上仍不清楚。在本研究中，应用宏基因组学和实时定量PCR来评估鸡粪便高温堆肥过程中ARGs的动态，特别是对人类健康具有高风险的ARGs、其宿主物种和细菌群落的致病性。结果表明，嗜热堆肥通过1）消除占总丰度80%的一半以上的ARG，2）显著降低高风险ARG的数量和丰度，3）显著去除ARG宿主和细菌群落的致病性，有效降低了抗生素耐药性的大部分传播风险。ARGs的衰减主要是由细菌群落的演替驱动的。然而，一些ARG的丰度，特别是与质粒相关的ARG，在冷却阶段反弹，这可能是由水平基因转移引起的。我们的研究表明，在嗜热堆肥的冷却阶段，最大限度地减少质粒相关ARG的水平转移，对于更有效地减少与抗生素耐药性传播相关的危险至关重要。
Abstract
Animal production contributes substantially to the dissemination of antibiotic resistance genes (ARGs) in the environment. Thermophilic composting is cost-effective for reducing hazards in animal wastes. However, ARGs can still persist in composts and the mechanism remains largely unclear. In the present study, metagenomics and real-time quantitative PCR were employed to assess the dynamics of ARGs, especially those of high risk to human health, their host species and pathogenicity of the bacterial community during thermophilic composting of chicken manure. The results showed that thermophilic composting was effective at reducing the majority of the spreading risk of antibiotic resistance by 1) eliminating more than half of allARGs that accounted for 80% of the total abundance, 2) reducing the number and abundance of high-risk ARGs significantly, and 3) removing the ARG hosts and the pathogenicity of the bacterial community substantially. The attenuation of ARGs was primarily driven by the bacterial community succession. However, the abundance of some ARGs, especially those associated with plasmids, rebounded during the cooling phase, likely caused by horizontal gene transfer. Our research reveals that minimising the horizontal transfer of plasmid-associated ARGs during the cooling phase of thermophilic composting is crucial for a more effective reduction of the hazards associated with the spread of antibiotic resistance.

https://www.sciencedirect.com/science/article/abs/pii/S0301479723000373