摘要
      土壤是抗生素抗性基因（ARGs）和微塑料的主要宿主。然而，土壤塑性层中抗生素耐药性的特征在很大程度上仍然未知。在这项研究中，我们使用宏基因组方法揭示了ARGs和细菌群落的变化模式，以及它们对三种类型的微塑料（光密度聚乙烯、LDPE、聚丙烯、PP、聚苯乙烯、PS）的反应，这些微塑料使用直径为550µm或75µm的颗粒。ARG的总丰度在塑性层中显著增加，并且在不同的塑性类型中有所不同。LDPE塑料层的ARG总丰度最高，Shannon多样性指数最低，表明该塑料层对土壤细菌多样性的负面影响最为严重。PP塑性圈含有较高相对丰度的致病菌约翰氏不动杆菌和大肠杆菌，表明塑性圈中富集的微生物群落具有较高的致病风险。具体而言，多药耐药基因（ceoB和MuxB）与四个以上的微生物类群共存，增加了ARG在致病菌中传播的潜在风险。这些发现表明，质体是获得和传播抗生素耐药性的热点，可能对土壤生态系统和人类健康产生长期负面影响。
Abstract
Soil serves as a major reservoir of both antibiotic resistance genes (ARGs) and microplastics. However, the characteristics of the antibiotic resistome in the soil plastisphere remain largely unknown. In this study, we used metagenomic approaches to reveal the changing patterns of ARGs and the bacterial community and their associations in response to three types of microplastics (light density polyethylene, LDPE; polypropylene, PP; polystyrene, PS) using particles 550 µm or 75 µm in diameter. The total ARG abundances significantly increased in the plastisphere and varied across plastic types. The LDPE plastisphere had the highest ARG total abundance and lowest Shannon diversity index, indicating that this plastic had the most severe negative impact on soil bacterial diversity. The PP plastisphere contained higher relative abundances of the pathogenic bacteria Acinetobacter johnsonii and Escherichia coli, demonstrating the higher pathogenic risk of the microbial communities enriched in the plastisphere. Specifically, multidrug resistance genes (ceoB and MuxB) co-existed with more than four microbial taxa, increasing the potential risk of ARG spread in pathogenic bacteria. These findings implied that the plastisphere acts as a hotspot for acquiring and spreading antibiotic resistance and may have long-term negative effects on the soil ecosystem and human health.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422010378