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 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China.
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 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China; Pearl River Water Resources Research Institute, Pearl River Water Resources Commission of the Ministry of Water Resources, Guangzhou, China.
Sci Total Environ. 2024 Jun 1;927:171991. doi: 10.1016/j.scitotenv.2024.171991. Epub 2024 Mar 26.
Landfill leachate is a hotspot in antibiotic resistance development. However, little is known about antibiotic resistome and host pathogens in leachate and their effects on surrounding groundwater. Here, metagenomic sequencing was used to explore profiles, host bacteria, environmental risks and influencing factors of antibiotic resistome in raw and treated leachate and surrounding groundwater of three landfills. Results showed detection of a total of 324 antibiotic resistance genes (ARGs). The ARGs conferring resistance to multidrug (8.8 %-25.7 %), aminoglycoside (13.1 %-39.2 %), sulfonamide (10.0 %-20.9 %), tetracycline (5.7 %-34.4 %) and macrolide-lincosamide-streptogramin (MLS, 5.3 %-29.5 %) were dominant in raw leachate, while multidrug resistance genes were the major ARGs in treated leachate (64.1 %-83.0 %) and groundwater (28.7 %-76.6 %). Source tracking analysis suggests non-negligible influence of leachate on the ARGs in groundwater. The pathogens including Acinetobacter pittii, Pseudomonas stutzeri and P. alcaligenes were the major ARG-carrying hosts. Variance partitioning analysis indicates that the microbial community, abiotic variables and their interaction contributed most to the antibiotic resistance development. Our results shed light on the dissemination and driving mechanisms of ARGs from leachate to the groundwater, indicating that a comprehensive risk assessment and efficient treatment approaches are needed to deal with ARGs in landfill leachate and nearby groundwater. ENVIRONMENTAL IMPLICATIONS: Antibiotic resistance genes are found abundant in the landfill sites, and these genes could be disseminated into groundwater via leaching of wastewater and infiltration of leachate. This results in deterioration of groundwater quality and human health risks posed by these ARGs and related pathogens. Thus measures should be taken to minimize potential negative impacts of landfills on the surrounding environment.
垃圾渗滤液是抗生素抗性发展的热点。然而，对于渗滤液中的抗生素抗性组和宿主病原体及其对周围地下水的影响知之甚少。在这里，我们使用宏基因组测序来探索三个垃圾填埋场的原始和处理后的渗滤液及周围地下水中的抗生素抗性组的特征、宿主细菌、环境风险和影响因素。结果表明，共检测到 324 种抗生素抗性基因（ARGs）。在原始渗滤液中，赋予对多种药物（8.8%-25.7%）、氨基糖苷类（13.1%-39.2%）、磺胺类（10.0%-20.9%）、四环素类（5.7%-34.4%）和大环内酯类-林可酰胺类-链阳菌素（MLS，5.3%-29.5%）耐药的 ARGs 占主导地位，而在处理后的渗滤液和地下水中，多种药物耐药基因是主要的 ARGs（64.1%-83.0%和 28.7%-76.6%）。来源追踪分析表明，渗滤液对地下水 ARGs 有不可忽视的影响。包括嗜水气单胞菌、施氏假单胞菌和产碱假单胞菌在内的病原体是主要的 ARG 携带宿主。方差分解分析表明，微生物群落、非生物变量及其相互作用对抗生素抗性的发展贡献最大。我们的研究结果揭示了 ARGs 从渗滤液到地下水传播和驱动机制，表明需要对垃圾渗滤液和附近地下水的 ARGs 进行综合风险评估和有效的处理方法。
抗生素抗性基因在垃圾填埋场中含量丰富，这些基因可以通过废水浸出和渗滤液渗透传播到地下水中。这导致地下水质量恶化，并对这些 ARGs 和相关病原体对人类健康构成风险。因此，应采取措施尽量减少垃圾填埋场对周围环境的潜在负面影响。
