Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China.
Sci Total Environ. 2020 Nov 10;742:140409. doi: 10.1016/j.scitotenv.2020.140409. Epub 2020 Jun 20.
Antibiotic residues could promote the dissemination of antibiotic resistance genes (ARGs) in the environments, and biodegradation represent a major route for antibiotic removal. Previous studies have showed that earthworm could enhance the degradation of certain organic contaminants, however, its effectiveness in ciprofloxacin removal and ARG reduction in soil remains unclear. In the present study, high-performance liquid chromatography, 16S rRNA gene sequencing and high-throughput quantitative PCR were employed to explore the effects of earthworm addition on ciprofloxacin removal and ARG abundance in ciprofloxacin-amended soil. Ciprofloxacin removal was significantly higher in earthworm cast as compare to control soil, and ARG abundance in earthworm cast was significantly lower than that of control soil. Procrustes analysis together with Mantel test showed that the ARG profiles were strongly associated with bacterial communities, indicating that the lower abundance of ARGs in cast samples could be attributed to changes in bacterial community compositions by earthworm activity. Flavobacterium and Turicibacter were enriched in cast samples, which were negatively correlated with ciprofloxacin concentration (p < 0.05), implying their potential roles in ciprofloxacin removal. These results suggested that earthworm gut is a hotspot for ciprofloxacin removal, and could be an option for mitigation of antibiotic pollution in soil.
抗生素残留会促进抗生素耐药基因（ARGs）在环境中的传播，而生物降解是抗生素去除的主要途径。先前的研究表明，蚯蚓可以增强某些有机污染物的降解，然而，其在土壤中去除环丙沙星和减少 ARG 的效果尚不清楚。在本研究中，采用高效液相色谱、16S rRNA 基因测序和高通量定量 PCR 技术，研究了蚯蚓添加对添加环丙沙星土壤中环丙沙星去除和 ARG 丰度的影响。与对照土壤相比，蚯蚓粪中环丙沙星的去除率明显更高，而蚯蚓粪中的 ARG 丰度明显低于对照土壤。普罗克汝斯分析和曼特尔检验表明，ARG 图谱与细菌群落密切相关，这表明蚯蚓活动引起的细菌群落组成的变化导致了 ARG 丰度的降低。在粪样中富集了黄杆菌属和Turicibacter ，它们与环丙沙星浓度呈负相关（p<0.05），表明它们在环丙沙星去除中可能发挥作用。这些结果表明，蚯蚓肠道是环丙沙星去除的热点，可能是减轻土壤中抗生素污染的一种选择。
