摘要
      自然生活在生物膜中的水性细菌不断暴露于药物残留物中，并定期释放到淡水环境中。在源头层面，抗生素排入河流已经多次与抗微生物耐药性的发展联系在一起。但是远离排放点的生物膜呢？作为高收入和中等收入国家的典型代表，研究了两条河流，这些河流的地点受到中等强度的分散污染。在河流原生岩石上形成的生物膜是环境暴露的完美代表。我们的研究结果表明，在远离热点的地方，所研究的生物膜中抗生素的数量有利于维持和富集现有的耐药菌株以及选择新的耐药突变体，并且这些有利条件会持续一段时间。因此，在这种类型的河流中，选择压力的环境风险不仅存在于城市化地区的下游，而且也可能存在于污水处理厂排放的上游和下游。尽管如此，相关性分析发现抗生素浓度与所测整合素及其相应抗性基因的丰度之间没有强烈的正相关性。尽管如此，这项工作也强调了考虑抗生素在热点以外的风险的必要性。
Abstract
Waterborne bacteria that naturally live in biofilms are continuously exposed to pharmaceutical residues, regularly released into the freshwater environment. At the source level, the discharge of antibiotics into rivers has already been repeatedly linked to the development of antimicrobial resistance. But what about biofilms away from the discharge point? Two rivers, with sites subject to dispersed contamination of medium intensity, were studied as typical representatives of high- and middle-income countries. The biofilms developed on rocks indigenous to rivers are perfectly representative of environmental exposure. Our results show that away from the hotspots, the amount of antibiotics in the biofilms studied favours the maintenance and enrichment of existing resistant strains as well as the selection of new resistant mutants, and these favourable conditions remain over a period of time. Thus, in this type of river, the environmental risk of selection pressure is not only present downstream of urbanized areas but is also possible upstream and far downstream of wastewater treatment plant discharges. Despite this, correlation analysis found no strong positive correlation between antibiotic concentrations and the abundance of measured integrons and their corresponding resistance genes. Nevertheless, this work highlights the need to consider the risks of antibiotics beyond hotspots as well.

https://www.sciencedirect.com/science/article/abs/pii/S0043135423000465