Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China.
Shandong Ecological Home Environmental Protection Co., LTD, Jinan, 250000, China.
Environ Pollut. 2024 Jan 15;341:122609. doi: 10.1016/j.envpol.2023.122609. Epub 2023 Sep 22.
Antibiotics and heavy metals added to livestock and poultry feed are excreted in manure, which is added to agricultural soil and causes severe pollution. However, the effects of oxytetracycline (OTC) and zinc (Zn), which are present at relatively high levels in feed additives, on antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and microbial communities have not been comprehensively studied. This study evaluated the effects of OTC and Zn on environmental factors, microorganisms, MGEs, and ARGs. The expression of MGEs in soil was stimulated by adding Zn at concentrations of 500 and 1000 mg/kg or OTC at concentrations of 30 and 100 mg/kg; however, the addition of their combination hindered the expression of MGEs in soil. The abundance of total MGEs and ARGs tended to decrease with increasing concentrations of Zn and OTC and the number of incubation days. Low and high OTC concentrations strongly inhibited sul and tet resistance genes, respectively. Network analysis showed that changes in the population of Firmicutes and Proteobacteria had the greatest impact on ARG abundance. Redundancy analysis revealed that MGEs, particularly intI2, facilitated the transfer and spread of ARGs and had the greatest impact on changes in ARG abundance. These findings provide reference values for the prevention and resolution of ecological and environmental risks posed by the presence of Zn and OTC in organic manure soil.
抗生素和重金属添加到牲畜和家禽饲料中会随粪便排出，这些粪便被添加到农业土壤中，会造成严重的污染。然而，在饲料添加剂中含量相对较高的土霉素（OTC）和锌（Zn）对抗生素抗性基因（ARGs）、可移动遗传元件（MGEs）和微生物群落的影响尚未得到全面研究。本研究评估了 OTC 和 Zn 对环境因子、微生物、MGEs 和 ARGs 的影响。在浓度为 500 和 1000 mg/kg 的 Zn 或浓度为 30 和 100 mg/kg 的 OTC 作用下，土壤中 MGEs 的表达受到刺激；然而，添加它们的组合会阻碍土壤中 MGEs 的表达。随着 Zn 和 OTC 浓度以及孵育天数的增加，总 MGEs 和 ARGs 的丰度趋于下降。低浓度和高浓度的 OTC 分别强烈抑制了 sul 和 tet 抗性基因。网络分析表明，Firmicutes 和 Proteobacteria 种群的变化对 ARG 丰度的影响最大。冗余分析表明，MGEs，特别是 intI2，促进了 ARGs 的转移和传播，对 ARG 丰度的变化影响最大。这些发现为预防和解决有机肥料土壤中 Zn 和 OTC 存在带来的生态和环境风险提供了参考价值。
