Rossi Florent, Péguilhan Raphaëlle, Turgeon Nathalie, Veillette Marc, Baray Jean-Luc, Deguillaume Laurent, Amato Pierre, Duchaine Caroline
Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada; Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Université Laval, Quebec City, Quebec, Canada.
Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France.
Sci Total Environ. 2023 Mar 20;865:161264. doi: 10.1016/j.scitotenv.2022.161264. Epub 2022 Dec 29.
Antibiotic resistance in bacteria is becoming a major sanitary concern worldwide. The extensive use of large quantities of antibiotics to sustain human activity has led to the rapid acquisition and maintenance of antibiotic resistant genes (ARGs) in bacteria and to their spread into the environment. Eventually, these can be disseminated over long distances by atmospheric transport. Here, we assessed the presence of ARGs in clouds as an indicator of long-distance travel potential of antibiotic resistance in the atmosphere. We hypothesized that a variety of ARGs can reach the altitude of clouds mainly located within the free troposphere. Once incorporated in the atmosphere, they are efficiently transported and their respective concentrations should differ depending on the sources and the geographical origin of the air masses. We deployed high-flow rate impingers and collected twelve clouds between September 2019 and October 2021 at the meteorological station of the puy de Dôme summit (1465 m a.s.l., France). Total airborne bacteria concentration was assessed by flow cytometry, and ARGs subtypes of the main families of antibiotic resistance (quinolone, sulfonamide, tetracycline; glycopeptide, aminoglycoside, β-lactamase, macrolide) including one mobile genetic element (transposase) were quantified by qPCR. Our results indicate the presence of 29 different ARGs' subtypes at concentrations ranging from 1.01 × 10 to 1.61 × 10 copies m of air. Clear distinctions could be observed between clouds in air masses transported over marine areas (Atlantic Ocean) and clouds influenced by continental surfaces. Specifically, quinolones (mostly qepA) resistance genes were prevalent in marine clouds (54 % of the total ARGs on average), whereas higher contributions of sulfonamide, tetracycline; glycopeptide, β-lactamase and macrolide were found in continental clouds. This study constitutes the first evidence for the presence of microbial ARGs in clouds at concentrations comparable to other natural environments. This highlights the atmosphere as routes for the dissemination of ARGs at large scale.
细菌中的抗生素耐药性正成为全球主要的卫生问题。大量使用抗生素以维持人类活动已导致细菌中抗生素耐药基因（ARGs）的快速获得和维持，并使其传播到环境中。最终，这些耐药基因可通过大气传输远距离扩散。在此，我们评估了云层中ARGs的存在情况，以此作为大气中抗生素耐药性远距离传播潜力的一个指标。我们假设多种ARGs能够到达主要位于对流层的云层高度。一旦进入大气，它们就能被有效传输，其各自的浓度应因气团的来源和地理起源而有所不同。我们在多姆山山顶气象站（法国，海拔1465米）于2019年9月至2021年10月期间部署了高流量撞击器，收集了12个云层样本。通过流式细胞术评估空气中细菌的总浓度，并通过定量聚合酶链反应（qPCR）对包括一种可移动遗传元件（转座酶）在内的主要抗生素耐药家族（喹诺酮、磺胺、四环素、糖肽、氨基糖苷、β-内酰胺酶、大环内酯）的ARGs亚型进行定量。我们的结果表明，存在29种不同的ARGs亚型，其浓度范围为每立方米空气1.01×10至1.61×10拷贝。在海洋区域（大西洋）上空传输的气团中的云层与受大陆表面影响的云层之间可以观察到明显差异。具体而言，喹诺酮（主要是qepA）耐药基因在海洋云层中普遍存在（平均占总ARGs的54%），而在大陆云层中磺胺、四环素、糖肽、β-内酰胺酶和大环内酯的占比更高。这项研究首次证明了云层中存在与其他自然环境浓度相当的微生物ARGs。这凸显了大气是ARGs大规模传播的途径。
