Gao Fang-Zhou, Jia Wei-Li, Li Bing, Zhang Min, He Liang-Ying, Bai Hong, Liu You-Sheng, Ying Guang-Guo
SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou, China; School of Environment, South China Normal University, University Town, Guangzhou, China.
Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
Environ Int. 2025 Jan;195:109239. doi: 10.1016/j.envint.2024.109239. Epub 2024 Dec 25.
Municipal landfills are hotspot sources of antimicrobial resistance (AMR) and are also important habitats of contaminant-degrading bacteria. However, high diversity of antibiotic resistance genes (ARGs) in landfills hinders assessing AMR risks in the affected environment. More concerned, whether there is co-selection or enrichment of antibiotic-resistant bacteria and contaminant-degrading bacteria in these extremely polluted environments is far less understood. Here, we collected metagenomic datasets of 32 raw leachate and 45 solid waste samples in 22 municipal landfills of China. The antibiotic resistome, antibiotic-resistant bacteria and contaminant-degrading bacteria were explored, and were then compared with other environmental types. Results showed that the antibiotic resistome in landfills contained 1,403 ARG subtypes, with the total abundance over the levels in natural environments and reaching the levels in human feces and sewage. Therein, 49 subtypes were listed as top priority ARGs for future surveillance based on the criteria of enrichment in landfills, mobilizable and present in pathogens. By comparing to those in less contaminated river environments, we elucidated an enrichment of antibiotic-resistant bacteria with contaminant-degrading potentials in landfills. Bacteria in Pseudomonadaceae, Moraxellaceae, Xanthomonadaceae and Enterobacteriaceae deserved the most concerns since 72.2 % of ARG hosts were classified to them. Klebsiella pneumoniae, Acinetobacter nosocomialis and Escherichia coli were abundant multidrug-resistant pathogenic species in raw leachate (∼10.2 % of total microbiomes), but they rarely carried contaminant-degradation genes. Notably, several bacterial genera belonging to Pseudomonadaceae had the most antibiotic-resistant, pathogenic, and contaminant-degrading potentials than other bacteria. Overall, the findings highlight environmental selection for contaminant-degrading antibiotic-resistant pathogens, and provide significant insights into AMR risks in municipal landfills.
城市垃圾填埋场是抗生素耐药性（AMR）的热点来源，也是污染物降解细菌的重要栖息地。然而，垃圾填埋场中抗生素抗性基因（ARG）的高度多样性阻碍了对受影响环境中AMR风险的评估。更令人担忧的是，在这些极端污染的环境中，抗生素抗性细菌和污染物降解细菌是否存在共选择或富集现象，目前还知之甚少。在此，我们收集了中国22个城市垃圾填埋场的32份原生渗滤液和45份固体废物样本的宏基因组数据集。对其抗生素抗性组、抗生素抗性细菌和污染物降解细菌进行了研究，并与其他环境类型进行了比较。结果表明，垃圾填埋场中的抗生素抗性组包含1403种ARG亚型，其总丰度超过自然环境中的水平，达到人类粪便和污水中的水平。其中，根据在垃圾填埋场中的富集、可移动性和在病原体中存在的标准，有49种亚型被列为未来监测的重点ARG。通过与污染较轻的河流环境中的情况进行比较，我们阐明了垃圾填埋场中具有污染物降解潜力的抗生素抗性细菌的富集情况。假单胞菌科、莫拉克斯氏菌科、黄单胞菌科和肠杆菌科中的细菌最值得关注，因为72.2%的ARG宿主属于这些科。肺炎克雷伯菌、医院不动杆菌和大肠杆菌是原生渗滤液中丰富的多重耐药病原菌（约占总微生物群的10.2%），但它们很少携带污染物降解基因。值得注意的是，与其他细菌相比，假单胞菌科的几个细菌属具有最强的抗生素抗性、致病性和污染物降解潜力。总体而言，这些发现突出了对污染物降解性抗生素抗性病原体的环境选择，并为城市垃圾填埋场中的AMR风险提供了重要见解。
