摘要

       迄今为止，垃圾填埋场是全球处理城市固体废物 (MSW) 的最常见做法。由于垃圾填埋场接收各种废物，包括未使用/过期的抗生素和生物活性废物，它逐渐成为培养抗生素抗性的巨大潜在生物反应器。垃圾填埋场中的抗生素抗性基因 (ARG) 可以通过垃圾渗滤液的泄漏流入环境，并对公众健康构成风险。使用高通量定量聚合酶链反应 (HT-qPCR)，我们调查了垃圾填埋场地下水中 ARG 的普遍性、多样性及其与各种移动遗传元件 (MGE) 的关联。共鉴定出 171 个独特的 ARG（属于 9 个 ARG 类型，包含 3 个主要抗性机制）和 8 个 MGE（6 个转座酶基因和 2 个整合子整合酶基因）。 ARG 的标准化丰度范围为 0.24 至 5.66 拷贝/细胞，其中多药、β-内酰胺和四环素抗性基因是最丰富的 ARG 类型。 MGEs和ARGs的共现模式和显着相关性表明MGEs可能在ARGs的持久性和增殖中起重要作用。 Mantel 测试和 Procrustes 分析表明 ARG 谱与细菌群落显着相关。变异分区分析 (VPA) 进一步表明，细菌群落变化占总 ARG 变异的 65.8%。此外，网络分析显示，家族水平的 15 个细菌分类群可能是 ARG 的潜在宿主。这些发现提供证据表明，MSW 垃圾填埋场附近的地下水是一个被低估的抗生素耐药性热点，并通过流动的受污染地下水导致 ARGs 的传播。

       Landfills are so far the most common practice for the disposals of municipal solid waste (MSW) worldwide. Since MSW landfill receives miscellaneous wastes, including unused/expired antibiotics and bioactive wastes, it gradually becomes a huge potential bioreactor for breeding antibiotic resistance. Antibiotic resistance genes (ARGs) in landfill can flow to the environment through leakage of landfill leachate and pose a risk to public health. Using high throughput quantitative Polymerase Chain Reaction (HT-qPCR), we investigated the prevalence, diversity of ARGs and its association with various mobile genetic elements (MGEs) in MSW landfill groundwater. Totally 171 unique ARGs (belonging to 9 ARG types, encompassing 3 major resistance mechanisms) and 8 MGEs (6 transposase genes, and 2 integron-integrase genes) were identified. The normalized abundance of ARG was ranging from 0.24 to 5.66 copies/cell with multidrug, beta-lactams and tetracycline resistance genes being the most abundant ARG types. The co-occurrence pattern and significant correlation between MGEs and ARGs, indicated that MGEs may play an important role in the persistence and proliferation of ARGs. A Mantel test and Procrustes analysis suggested that ARG profiles were significantly correlated with bacterial community. Variation partitioning analysis (VPA) further demonstrated that bacterial community shifts contribute 65.8% of the total ARG variations. Additionally network analysis revealed that 15 bacterial taxa at family level might be the potential hosts of ARGs. These findings provide evidence that groundwater near MSW landfill is an underappreciated hotspot of antibiotic resistance and contribute to the spread of ARGs via the flowing contaminated groundwater.

https://www.sciencedirect.com/science/article/abs/pii/S0048969717318673