Aerobic composting is a common way for the disposal of feces produced in animal husbandry, and can reduce the release of antibiotic resistance genes (ARGs) from feces into the environment. In this study, we collected samples from two distinct treatments of swine manure compost with and without ceftiofur (CEF), and identified the ARGs, mobile genetic elements (MGEs), and bacterial community by metagenomic sequencing. The impacts of CEF on the bacterial community composition and fate of ARGs and MGEs were investigated. With increasing composting temperature and pH, the concentration of CEF in the manure decreased rapidly, with a degradation half-life of 1.12 d and a 100% removal rate after 10 d of aerobic composting. Metagenomics demonstrated that CEF in the manure might inhibit the growth of Firmicutes and Proteobacteria, thereby reducing some ARGs and MGEs hosted by these two bacteria, which was further confirmed by the variations of ARGs and MGEs. A further redundancy analysis suggested that pH and temperature are key environmental factors affecting ARG removal during composting, and intI1 and bacterial communities also have significant influence on ARG abundance. These results are of great significance for promoting the removal of some ARGs from animal manure by controlling some key environmental factors and the type of antibiotics used in animals.

中文翻译：

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猪粪中的头孢噻呋有助于减少堆肥过程中的病原体和抗生素抗性基因


好氧堆肥是处理畜牧业产生的粪便的常用方法，可以减少粪便中抗生素抗性基因（ARG）释放到环境中。在这项研究中，我们从添加和不添加头孢噻呋 (CEF) 的两种不同的猪粪堆肥处理中收集了样品，并通过宏基因组测序鉴定了 ARG、移动遗传元件 (MGE) 和细菌群落。研究了 CEF 对细菌群落组成以及 ARG 和 MGE 命运的影响。随着堆肥温度和pH的升高，粪便中CEF的浓度迅速下降，好氧堆肥10 d后降解半衰期为1.12 d，去除率达到100%。宏基因组学表明，粪便中的CEF可能会抑制厚壁菌门和变形菌门的生长，从而减少这两种细菌寄生的部分ARG和MGE，这也被ARG和MGE的变异进一步证实。进一步的冗余分析表明，pH和温度是影响堆肥过程中ARG去除的关键环境因素，intI1和细菌群落对ARG丰度也有显着影响。这些结果对于通过控制一些关键环境因素和动物使用的抗生素类型来促进动物粪便中部分ARGs的去除具有重要意义。