摘要

       从废水中回收的鸟粪石是磷和氮的可再生来源，可用作植物生长的肥料。然而，抗生素和抗性组可以在源自废水的鸟粪石中富集。对将鸟粪石应用于土壤后的潜在风险的深入了解仍然难以捉摸。在这里，我们使用高通量定量 PCR 分析了芸苔属植物鸟粪石、土壤、根际和叶际中的抗生素抗性基因 (ARG) 和移动遗传元件 (MGE)。共检测到 165 个 ARG 和 10 个 MGE。发现鸟粪石的应用增加了土壤、根际和叶际中 ARGs 的丰度和多样性。此外，鉴定出仅在芸苔属叶际和鸟粪石之间共享的 ARG，表明鸟粪石是在叶际中发现的 ARG 的重要来源。此外，发现根际和叶际之间共享的 OTU 与 ARG 显着相关，这表明叶和根中的微生物群可以相互连接，并且 ARG 可能使用细菌作为传播介质通过根际从鸟粪石转移到植物表面。这些发现表明鸟粪石作为一种有机肥料可以促进抗生素耐药性向人类食物链的传播，这种环境获得性抗生素耐药性应纳入人类健康风险评估系统。

       Struvite recovered from wastewater is a renewable source of phosphorus and nitrogen and can be used as fertilizer for plant growth. However, antibiotics and resistome can be enriched in the struvite derived from wastewater. Robust understanding of the potential risks after struvite application to soils has remained elusive. Here, we profiled antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) in struvite, soil, rhizosphere and phyllosphere of Brassica using high-throughput quantitative PCR. A total of 165 ARGs and 10 MGEs were detected. Application of struvite was found to increase both the abundance and diversity of ARGs in soil, rhizosphere and phyllosphere. In addition, ARGs shared exclusively between Brassica phyllosphere and struvite were identified, indicating that struvite was an important source of ARGs found in phyllosphere. Furthermore, OTUs shared between rhizosphere and phyllosphere were found to significantly correlate with ARGs, suggesting that microbiota in leaf and root could interconnect and ARGs might transfer from struvite to the surface of plants via rhizosphere using bacteria as spreading medium. These findings demonstrated that struvite as an organic fertilizer can facilitate the spread of antibiotic resistance into human food chain and this environment-acquired antibiotic resistance should be put into human health risk assessment system.

https://pubs.acs.org/doi/abs/10.1021/acs.est.7b01420