摘要
      微塑料（MP）是微生物和抗生素抗性基因（ARGs）的载体，有助于病原菌和ARGs在各种环境中的传播。MPs表面生物膜中的微生物群落和ARGs模式，也被称为塑料层，已成为全球关注的问题。尽管已经检测到塑料层中的抗生素耐药性，但流域城市化如何影响微塑料生物膜中潜在病原体和ARGs的模式仍不清楚。在这里，我们比较了细菌群落、细菌分类群之间的相互作用、致病菌以及质体及其周围水体之间的ARGs，并揭示了城市化对它们的广泛影响。我们的研究结果表明，塑料层中的细菌群落和相互作用与周围水中的不同。微塑料从水中选择性富集拟杆菌。在非城市化地区，氧光细菌在塑料层中的丰度显著（p<0.05）高于在水中的丰度，而α-变形菌在塑料层的丰度显著高于城市化地区的水中的丰度（p<0.05）。城市化地区的病原菌、ARGs和移动遗传元素（MGE）显著高于非城市化地区（p<0.05）。MPs选择性富集了携带ARG的潜在病原体，即肺炎克雷伯菌和阴沟肠杆菌，并对不同城市化水平的水中ARG和病原体的相对丰度表现出明显的影响。我们进一步发现ARGs与MGE和致病菌显著相关。这些结果表明，MPs将促进ARGs在包括致病菌在内的微生物中的传播，而城市化将影响MPs对水中微生物、病原体和ARGs的影响。高水平的城市化可以增强MPs在水生系统中对病原体和ARGs的富集，并增加水生环境中的微生物风险。我们的研究结果强调了控制ARGs在病原体中传播的必要性，以及城市地区生态系统中塑料产品的使用。
Abstract
Microplastics (MPs) serve as vectors for microorganisms and antibiotic resistance genes (ARGs) and contribute to the spread of pathogenic bacteria and ARGs across various environments. Patterns of microbial communities and ARGs in the biofilm on the surface of MPs, also termed as plastisphere, have become an issue of global concern. Although antibiotic resistome in the plastisphere has been detected, how watershed urbanization affects patterns of potential pathogens and ARGs in the microplastic biofilms is still unclear. Here, we compared the bacterial communities, the interaction between bacterial taxa, pathogenic bacteria, and ARGs between the plastisphere and their surrounding water, and revealed the extensive influence of urbanization on them. Our results showed that bacterial communities and interactions in the plastisphere differed from those in their surrounding water. Microplastics selectively enriched Bacteroidetes from water. In non-urbanized area, the abundance of Oxyphotobacteria was significantly (p < 0.05) higher in plastisphere than that in water, while α-Proteobacteria was significantly (p < 0.05) higher in plastisphere than those in water of urbanized area. Pathogenic bacteria, ARGs, and mobile genetic elements (MGEs) were significantly (p < 0.05) higher in the urbanized area than those in non-urbanized area. MPs selectively enriched ARG-carrying potential pathogens, i.e., Klebsiella pneumoniae and Enterobacter cloacae, and exhibited a distinct effect on the relative abundance of ARG and pathogens in water with different urbanization levels. We further found ARGs were significantly correlated to MGEs and pathogenic bacteria. These results suggested that MPs would promote the dissemination of ARGs among microbes including pathogenic bacteria, and urbanization would affect the impact of MPs on microbes, pathogens, and ARGs in water. A high level of urbanization could enhance the enrichment of pathogens and ARGs by MPs in aquatic systems and increase microbial risk in aquatic environments. Our findings highlighted the necessity of controlling the spread of ARGs among pathogens and the usage of plastic products in ecosystems of urban areas.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122013999