摘要
      重金属有可能影响抗微生物耐药性（AMR）的传播。然而，重金属对AMR的影响尚未明确揭示。在这项研究中，我们使用 微观实验和宏基因组学来检测猪粪中常见的Cu和Zn水平是否会影响AMR在施肥土壤中的传播。我们发现，施用粪肥后，204个ARGs的丰度显著增加，尽管粪肥不含抗生素残留。然而，低Cu和Zn（分别为500和1000mg/kg）的联合添加仅导致14个ARG显著增加，而高Cu和锌（分别为1000和3000mg/kg）导致27个ARG明显增加。这些数字的差异表明，粪肥中的因素是AMR传播的主要驱动原因，而不是金属改良剂。杀生物剂和金属抗性基因（BMRGs）以及可移动遗传元件（MGE）也有类似的趋势。这项研究对AMR的传播与粪肥施用和重金属在常见报告水平上的影响提供了更深入的见解。我们的研究结果表明，除了限制重金属添加外，还需要采取更全面的措施来控制养猪业的AMR。
Abstract
Heavy metals have the potential to influence the transmission of antimicrobial resistance (AMR). However, the effect on AMR caused by heavy metals has not been clearly revealed. In this study, we used a microcosm experiment and metagenomics to examine whether common levels of Cu and Zn in pig manure influence AMR transmission in manured soil. We found that the abundance of 204 ARGs significantly increased after manure application, even though the manure did not contain antibiotic residuals. However, the combined addition of low Cu and Zn (500 and 1000 mg/kg, respectively) only caused 14 ARGs to significantly increase, and high Cu and Zn (1000 and 3000 mg/kg, respectively) caused 27 ARGs to significantly increase. The disparity of these numbers suggested that factors within the manure were the primary driving reasons for AMR transmission, rather than metal amendments. A similar trend was found for biocide and metal resistance genes (BMRGs) and mobile genetic elements (MGEs). This study offers deeper insights into AMR transmission in relation to the effects of manure application and heavy metals at commonly reported levels. Our findings recommend that more comprehensive measures in controlling AMR in the pig industry are needed apart from restricting heavy metal additions.

https://www.mdpi.com/1660-4601/19/18/11265