摘要

     堆肥已被广泛用于将畜禽粪便转化为有机肥料。然而，畜禽粪便中含有多种污染物，包括抗生素和抗药性基因（ARGs）。本文研究了商业化畜禽粪便堆肥过程中抗生素抗性的变化及其影响因素。结果表明，堆肥能有效地降低土壤中ARGs和可移动基因元件的相对丰度。作为堆肥样品中的优势菌门，ARGs的主要潜在寄主是放线菌，如白杆菌、分枝杆菌和未分类的热单孢菌科。同时，嗜肺军团菌、腐生葡萄球菌、杜克雷嗜血杆菌和土风杆菌可能是ARGs的主要潜在致病宿主。冗余分析表明，堆肥过程中ARGs的消散与水分等环境因素有关。在堆肥过程中，细菌的种群演替、杀菌剂和金属抗性基因（BMRGs）是构成抗药性的决定因素。然而，堆肥产品在施肥后ARGs和病原体的残留仍可能对人类和农作物造成危害。

    Composting has been widely used to turn livestock manure into organic fertilizer. However, livestock manure contains various contaminants including antibiotics and antibiotic resistance genes (ARGs). Here we investigated the variation of antibiotic resistome and its influencing factors during a commercial livestock manure composting. The results showed that composting could effectively reduce the relative abundance of ARGs and mobile genic elements (MGEs). As the dominant phylum in the composting samples, the key potential bacterial host of ARGs were Actinobacteria such as Leucobacter, Mycobacterium and Thermomonosporaceae unclassified. Meanwhile, Legionella pneumophila, Staphylococcus saprophyticus, Haemophilus ducreyi and Siccibacter turicensis may be the key potential pathogenic host of ARGs because of their co-occurrence with ARG subtypes. Redundancy analysis showed that the dissipation of ARGs during composting was linked to various environmental factors such as moisture. Bacterial succession as well as profile of biocide and metal resistance genes (BMRGs) were the determinants which constructed the antibiotic resistome during manure composting. However, the residues of ARGs and pathogens in compost products may still pose risks to human and crops after fertilization.

     https://www.sciencedirect.com/science/article/pii/S0160412019333057