Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Science, China Agricultural University, Beijing 100193, China.
Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Science, China Agricultural University, Beijing 100193, China.
Environ Int. 2024 Aug;190:108900. doi: 10.1016/j.envint.2024.108900. Epub 2024 Jul 22.
The elevated levels of antibiotic resistance genes (ARGs) in livestock manure represent a significant threat to both the environment and human health. Composting has been recognized as an effective strategy to mitigate the abundance of ARGs in manure. However, notable rebounds in ARGs abundance have been observed during this process. This study explored the changes in ARGs abundance and the underlying influencing factors during the composting of carnivore (chicken and pig) and herbivore (sheep and cow) manures, along with mushroom residues. The findings revealed that the total relative abundance of ARGs increased by 6.96 and 10.94 folds in chicken and pig manure composts, respectively, whereas it decreased by a remarkable 91.72% and 98.37% in sheep and cow manure composts. Nitrogen content emerged as the primary physicochemical factors governing the abundance of ARGs in chicken and pig manure composts. Conversely, carbon content played a pivotal role in determining ARGs abundance in chicken and pig manure composts. Furthermore, the presence of dominant hosts, such as Corynebacterium, Bacillus, and Clostridium, along with emerging bacteria like Thermobifida, Saccharomonospora, and Actinomadura, contributed significantly to the enrichment of total ARGs, including tetG, tetO, tetX, and sul2, in chicken and pig manure composts. The coexistence of these genes with mobile genetic elements and a plethora of host bacteria, coupled with their high abundance, renders them particularly high-risk ARGs. On the other hand, the observed decrease in the abundance of total ARGs in sheep and cow manure composts can be attributed to the decline in the population of host bacteria, specifically Atopostipes, Psychrobacter, and Corynebacterium. Collectively, these results provide crucial insights into the management of ARGs risks and offer essential theoretical support for enhancing the safe utilization of organic fertilizer in agriculture.
畜禽（鸡、猪）和草食动物（羊、牛）粪便及菌菇渣堆肥过程中抗生素抗性基因（ARGs）的变化及其影响因素研究
粪便中抗生素抗性基因（ARGs）水平的升高对环境和人类健康构成了重大威胁。堆肥已被认为是减少粪便中 ARGs 丰度的有效策略。然而，在这个过程中，ARGs 的丰度却出现了显著反弹。本研究探讨了在堆肥过程中，草食动物（羊、牛）和肉食动物（鸡、猪）粪便及菌菇渣中 ARGs 丰度的变化及其潜在影响因素。研究结果表明，鸡粪和猪粪堆肥中 ARGs 的总相对丰度分别增加了 6.96 和 10.94 倍，而羊粪和牛粪堆肥中 ARGs 的总相对丰度则分别显著减少了 91.72%和 98.37%。氮含量是鸡粪和猪粪堆肥中 ARGs 丰度的主要理化因素。而碳含量则是鸡粪和猪粪堆肥中 ARGs 丰度的关键决定因素。此外，优势宿主（如棒状杆菌属、芽孢杆菌属和梭菌属）和新兴细菌（如纤维单胞菌属、糖单孢菌属和链霉菌属）的存在，以及 tetG、tetO、tetX 和 sul2 等总 ARGs 的富集，对鸡粪和猪粪堆肥中 ARGs 的富集也有显著贡献。这些基因与移动遗传元件和大量宿主细菌共存，且丰度较高，使其成为高风险 ARGs。另一方面，羊粪和牛粪堆肥中总 ARGs 丰度的下降归因于宿主细菌（如梭状芽孢杆菌属、假单胞菌属和棒状杆菌属）数量的减少。综上所述，这些结果为 ARGs 风险的管理提供了重要的见解，并为提高农业有机肥料的安全利用提供了重要的理论支持。
