Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs/Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, China.
Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs/Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin 300191, China; College of Resources & Environment of Huazhong Agricultural University, Wuhan 430070, China.
Sci Total Environ. 2023 Aug 10;885:163907. doi: 10.1016/j.scitotenv.2023.163907. Epub 2023 May 4.
The contamination of greenhouse vegetable soils with antibiotics and antibiotic resistance genes (ARGs), caused by the application of livestock and poultry manure, is a prominent environmental problem. In this study, the effects of two ecological earthworms (endogeic Metaphire guillelmi and epigeic Eisenia fetida) on the accumulation and transfer of chlortetracycline (CTC) and ARGs in a soil-lettuce system were studied via pot experiments. The results revealed that earthworm application accelerated the removal of the CTC from the soil and lettuce roots and leaves, with the CTC content reducing by 11.7-22.8 %, 15.7-36.1 %, and 8.93-19.6 % compared with that of the control, respectively. Both earthworms significantly reduced the CTC uptake by lettuce roots from the soil (P < 0.05) but did not change the CTC transfer efficiency from the roots to leaves. The high-throughput quantitative PCR results showed that the relative abundance of ARGs in the soil and lettuce roots and leaves decreased by 22.4-27.0 %, 25.1-44.1 %, and 24.4-25.4 %, respectively, with the application of earthworms. Earthworm addition decreased the interspecific bacterial interactions and the relative abundance of mobile genetic elements (MGEs), which helped reduce the dissemination of ARGs. Furthermore, some indigenous soil antibiotic degraders (Pseudomonas, Flavobacterium, Sphingobium, and Microbacterium) were stimulated by the earthworms. The results of redundancy analysis indicated that the bacterial community composition, CTC residues, and MGEs were the main parameters affecting the distribution of ARGs, accounting for 91.1 % of the total distribution. In addition, the bacterial function prediction results showed that the addition of earthworms reduced the abundance of some pathogenic bacteria in the system. Overall, our findings imply that earthworm application can substantially reduce the accumulation and transmission risk of antibiotics and ARGs in soil-lettuce systems, providing a cost-effective soil bioremediation practice for addressing antibiotic and ARGs contamination to guarantee the safety of vegetables and human health.
抗生素和抗生素抗性基因（ARGs）在集约化温室蔬菜土壤中的积累和传播是一个突出的环境问题，本研究通过温室盆栽实验，研究了两种生态蚯蚓（内栖性赤子爱胜蚓和表栖性太平二号蚯蚓）对土壤-生菜系统中氯四环素（CTC）和 ARGs 积累和转移的影响。结果表明，蚯蚓的添加加速了土壤和生菜根系及叶片中 CTC 的去除，与对照相比，土壤和生菜根系及叶片中 CTC 含量分别降低了 11.7-22.8%、15.7-36.1%和 8.93-19.6%。两种蚯蚓均显著降低了生菜根系从土壤中吸收 CTC（P<0.05），但并未改变 CTC 从根系向叶片的转移效率。高通量定量 PCR 结果表明，蚯蚓的添加使土壤和生菜根系及叶片中 ARGs 的相对丰度分别降低了 22.4-27.0%、25.1-44.1%和 24.4-25.4%。蚯蚓的添加降低了种间细菌相互作用和移动遗传元件（MGEs）的相对丰度，有助于减少 ARGs 的传播。此外，一些土著土壤抗生素降解菌（假单胞菌、黄杆菌、鞘氨醇单胞菌和微杆菌）受到蚯蚓的刺激。冗余分析结果表明，细菌群落组成、CTC 残留和 MGEs 是影响 ARGs 分布的主要参数，占总分布的 91.1%。此外，细菌功能预测结果表明，蚯蚓的添加降低了系统中一些致病菌的丰度。总之，本研究结果表明，蚯蚓的添加可以显著降低土壤-生菜系统中抗生素和 ARGs 的积累和传播风险，为解决抗生素和 ARGs 污染提供了一种具有成本效益的土壤生物修复实践，以保障蔬菜和人类健康。
