INSERM, CHU Limoges, RESINFIT, U1092, Univ. Limoges, F-87000, Limoges, France; CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Univ. Grenoble Alpes, 38000, Grenoble, France.
Institut Pasteur, Département Biologie Computationnelle, Université Paris Cité, F-75015, Paris, France; Biomics Pole, CITECH, Institut Pasteur, F-75015, Paris, France.
Water Res. 2023 Oct 1;244:120408. doi: 10.1016/j.watres.2023.120408. Epub 2023 Jul 25.
Understanding the dynamics of antibiotic resistance gene (ARG) transfer and dissemination in natural environments remains challenging. Biofilms play a crucial role in bacterial survival and antimicrobial resistance (AMR) dissemination in natural environments, particularly in aquatic systems. This study focused on hospital and urban wastewater (WW) biofilms to investigate the potential for ARG dissemination through mobile genetic elements (MGEs). The analysis included assessing the biofilm extracellular polymeric substances (EPS), microbiota composition as well as metatranscriptomic profiling of the resistome and mobilome. We produced both in vitro and in situ biofilms and performed phenotypic and genomic analyses. In the in vitro setup, untreated urban and hospital WW was used to establish biofilm reactors, with ciprofloxacin added as a selective agent at minimal selective concentration. In the in situ setup, biofilms were developed directly in hospital and urban WW pipes. We first showed that a) the composition of EPS differed depending on the growth environment (in situ and in vitro) and the sampling origin (hospital vs urban WW) and that b) ciprofloxacin impacted the composition of the EPS. The metatranscriptomic approach showed that a) expression of several ARGs and MGEs increased upon adding ciprofloxacin for biofilms from hospital WW only and b) that the abundance and type of plasmids that carried individual or multiple ARGs varied depending on the WW origins of the biofilms. When the same plasmids were present in both, urban and hospital WW biofilms, they carried different ARGs. We showed that hospital and urban wastewaters shaped the structure and active resistome of environmental biofilms, and we confirmed that hospital WW is an important hot spot for the dissemination and selection of antimicrobial resistance. Our study provides a comprehensive assessment of WW biofilms as crucial hotspots for ARG transfer. Hospital WW biofilms exhibited distinct characteristics, including higher eDNA abundance and expression levels of ARGs and MGEs, highlighting their role in antimicrobial resistance dissemination. These findings emphasize the importance of understanding the structural, ecological, functional, and genetic organization of biofilms in anthropized environments and their contribution to antibiotic resistance dynamics.
理解抗生素耐药基因（ARG）在自然环境中的转移和传播动态仍然具有挑战性。生物膜在自然环境中（特别是在水生系统中）对细菌的生存和抗生素耐药性（AMR）传播起着至关重要的作用。本研究集中于医院和城市废水（WW）生物膜，以研究通过移动遗传元件（MGE）传播 ARG 的潜力。该分析包括评估生物膜细胞外聚合物物质（EPS）、微生物群落组成以及抗性组和移动组的宏转录组谱。我们制作了体外和原位生物膜，并进行了表型和基因组分析。在体外设置中，使用未经处理的城市和医院 WW 来建立生物膜反应器，并以最小选择浓度添加环丙沙星作为选择性试剂。在原位设置中，直接在医院和城市 WW 管道中开发生物膜。我们首先表明，a）EPS 的组成取决于生长环境（原位和体外）和采样来源（医院与城市 WW），b）环丙沙星影响 EPS 的组成。宏转录组学方法表明，a）仅来自医院 WW 的生物膜在添加环丙沙星后，几种 ARG 和 MGE 的表达增加，b）携带单个或多个 ARG 的质粒的丰度和类型取决于生物膜的 WW 来源。当相同的质粒存在于城市和医院 WW 生物膜中时，它们携带不同的 ARG。我们表明，医院和城市废水塑造了环境生物膜的结构和活性抗性组，并且我们证实医院 WW 是抗菌药物耐药性传播和选择的重要热点。我们的研究提供了对 WW 生物膜作为 ARG 转移关键热点的综合评估。医院 WW 生物膜表现出独特的特征，包括更高的 eDNA 丰度和 ARG 和 MGE 的表达水平，突出了它们在抗菌药物耐药性传播中的作用。这些发现强调了理解人为环境中生物膜的结构、生态、功能和遗传组织及其对抗生素耐药性动态的贡献的重要性。
