摘要
      微塑料（MP）和抗生素抗性基因（ARGs）都在废活性污泥（WAS）中被大量检测到。然而，不同MP对ARG的出现、传播及其潜在机制的独特影响仍不清楚。在本研究中，进行了长期半连续消化器，以检测厌氧污泥消化中ARGs和抗生素抗性细菌（ARB）对两种不同的典型MP（聚乙烯（PE）和聚氯乙烯（PVC））的反应。宏基因组学结果表明，PE和PVC MP使蒸煮器中ARGs的丰度分别增加14.8%和23.6%。ARB也富含PE和PVC MP，不动杆菌属和沙门氏菌属是主要的ARB。进一步的研究表明，PVC MPs刺激人类致病菌（HPB）和功能微生物（FM）获得ARGs，但PE MPs不刺激。网络分析表明，在MP暴露后，更多的ARG倾向于与HBP和FM共存，更重要的是，观察到新的细菌可能通过MP应激消化器中的水平基因流（HGF）获得ARG。参与HGF过程的基因，包括活性氧（ROS）产生、细胞膜通透性、细胞外聚合物（EPS）分泌和ATP合成，也被MPs增强，从而归因于ARGs传播的促进。这些发现为MPs在厌氧污泥消化中对ARGs的命运、宿主和传播的独特贡献提供了先进的见解。
Abstract
Both microplastics (MPs) and antibiotic resistance genes (ARGs) are intensively detected in waste activated sludge (WAS). However, the distinctive impacts of different MPs on ARGs emergence, dissemination, and its potential mechanisms remain unclear. In this study, long-term semi-continuous digesters were performed to examine the profiles of ARGs and antibiotic-resistant bacteria (ARB) in response to two different typical MPs (polyethylene (PE) and polyvinyl chloride (PVC)) in anaerobic sludge digestion. Metagenomic results show that PE- and PVC-MPs increase ARGs abundance by 14.8% and 23.6% in digester, respectively. ARB are also enriched by PE- and PVC-MPs, Acinetobacter sp. and Salmonella sp. are the dominant ARB. Further exploration reveals that PVC-MPs stimulates the acquisition of ARGs by human pathogen bacteria (HPB) and functional microorganisms (FMs), but PE-MPs doesn't. Network analysis shows that more ARGs tend to co-occur with HBP and FMs after MPs exposure, and more importantly, new bacteria are observed to acquire ARGs possibly via horizontal gene flow (HGF) in MPs-stressed digester. The genes involved in the HGF process, including reactive oxygen species (ROS) production, cell membrane permeability, extracellular polymeric substances (EPS) secretion, and ATP synthesis, are also enhanced by MPs, thereby attributing to the promoted ARGs dissemination. These findings offer advanced insights into the distinctive contribution of MPs to fate, host, dissemination of ARGs in anaerobic sludge digestion.

https://www.sciencedirect.com/science/article/abs/pii/S004313542201301X