摘要
      缺乏关于ARGs在淡水生物膜中分布的全面全球概况。我们利用宏基因组方法揭示了来自四个国家38个采样点的96个淡水生物膜样本中ARGs的多样性、丰度、可转移性和宿主。大量的ARGs与杆菌肽、多药、多粘菌素-大环内酯-林克酰胺-链脲菌素（MLS）氨基糖苷、β-内酰胺、氯霉素、磺酰胺和四环素耐药性有关，与人类或兽医常用的抗生素谱一致。正如预期的那样，淡水生物膜栖息地的抗性受到地理位置和人类足迹的显著影响。基于网络分析揭示的共现模式，提出了mdtC、kdpE和emrB作为淡水生物膜中ARG指标，可用于定量评估其他46种共现ARG亚型的丰度。宏基因组组装分析显示，已鉴定的ARGs由超过46个细菌门宿主，包括各种病原体，这大大扩展了对淡水生物膜中抗性体多样性的了解。我们的研究指出了生物膜在携带ARGs中的核心作用。研究结果可以增进对ARGs在淡水栖息地分布的了解，从而加强ARGs的全球环境风险评估和管理。
Abstract
A comprehensive global profile of the distribution of ARGs in freshwater biofilms is lacking. We utilized metagenomic approaches to reveal the diversity, abundance, transferability and hosts of ARGs in 96 freshwater biofilm samples from 38 sampling sites across four countries. The abundant ARGs were associated with bacitracin, multidrug, polymyxin macrolide-lincosamide-streptogramin (MLS) aminoglycoside, β-lactam, chloramphenicol, sulfonamide and tetracycline resistance, consistent with the spectrum of antibiotics commonly used in human or veterinary medicine. As expected, the resistome in freshwater biofilm habitats was significantly influenced by geographical location and human footprint. Based on the co-occurrence pattern revealed by network analysis, mdtC, kdpE, and emrB were proposed as ARG indicators in freshwater biofilms that can be used to evaluate the abundance of 46 other co-occurring ARG subtypes quantitatively. Metagenomic assembly analysis revealed that the identified ARGs were hosted by more than 46 bacterial phyla, including various pathogens, which greatly expands the knowledge of resistome diversity in freshwater biofilms. Our study points to the central roles of biofilms in harbouring ARGs. The results could enhance understanding the distribution of ARGs in freshwater habitats, thereby strengthening the global environmental risk assessment and management of ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S0048969721069114