摘要

       抗生素抗性细菌感染是人类健康的主要威胁之一。阐明环境在其传播中的作用的研究仍处于起步阶段，然而，似乎不同的环境可能充当长期存在于微生物群落中的抗生素抗性基因 (ARG) 的储存库。越来越多的研究针对 ARGs 在暴露于人类活动的水和土壤中的存在和持久性；然而，他们很少考虑在这些环境中占主导地位的空间/时间可变性。在这里，我们通过比较降雨期间基因丰度的测量值与每年的基因丰度测量值，评估了中雨事件（4 毫米雨 h-1）对 ARG（tetA、ermB、blaCTXM、sulII 和 qnrS）丰度和分布的影响。平均，在一条大型亚高山河流的水域中。 ARG 丰度在降雨事件期间全部增加，然后与几个微生物、物理和化学变量相关联，以确定它们的潜在来源。降雨期间 ARG 丰度的增加（总 ARG：24 倍）伴随着总磷、N-NH4 和微生物聚集体的增加。我们的结果表明适度降雨对 ARGs 的丰度有很强的影响，并表明流域是它们的来源。然后应在 ARG 动态建模和管理中考虑适度降雨对人类活动地区的影响。

       Infections with antibiotic resistant bacteria are among the major threats for human health. Studies elucidating the role of the environment in their spread are still in their infancy, it, however, seems that different environments might function as a long-term reservoir of antibiotic resistance genes (ARGs) that reside within their microbial communities. An increasing number of studies target the presence and the persistence of ARGs in waters and soils that are exposed to human activities; they, however, rarely consider the spatial/temporal variability that predominate in these environments. Here we evaluated the effect of a moderate rain event (4 mm rain h−1) on the abundance and distribution of ARGs (tetA, ermB, blaCTXM, sulII, and qnrS), by comparing measurements of gene abundances during the rainfall to the yearly average, in the waters of a large subalpine river. ARG abundances, which all increased during the rain event, were then correlated to several microbiological, physical and chemical variables, in order to establish their potential origin. Increments in ARG abundances during rainfall (total ARGs: 24 fold) was concomitant to an increase in total phosphorous, N-NH4, and microbial aggregates. Our results show a strong influence of a moderate rainfall on the abundances of ARGs, and suggest the catchment as their source. The impact of moderate rainfalls in areas exposed to anthropic activities should then be considered in modelling and management of ARG dynamics.

https://www.sciencedirect.com/science/article/abs/pii/S0269749116327427