School of Civil Engineering and Geosciences, Newcastle University Newcastle upon Tyne, UK ; David Livingstone Centre for Sustainability, Department of Civil and Environmental Engineering, University of Strathclyde Glasgow, UK.
Front Microbiol. 2012 Nov 23;3:396. doi: 10.3389/fmicb.2012.00396. eCollection 2012.
Numerous studies have quantified antibiotic resistance genes (ARG) in rivers and streams around the world, and significant relationships have been shown that relate different pollutant outputs and increased local ARG levels. However, most studies have not considered ambient flow conditions, which can vary dramatically especially in tropical countries. Here, ARG were quantified in water column and sediment samples during the dry- and wet-seasons to assess how seasonal and other factors influence ARG transport down the Almendares River (Havana, Cuba). Eight locations were sampled and stream flow estimated during both seasons; qPCR was used to quantify four tetracycline, two erythromycin, and three beta-lactam resistance genes. ARG concentrations were higher in wet-season versus dry-season samples, which combined with higher flows, indicated much greater ARG transport downstream during the wet-season. However, water column ARG levels were more spatially variable in the dry-season than the wet-season, with the proximity of waste outfalls strongly influencing local ARG levels. Results confirm that dry-season sampling provides a useful picture of the impact of individual waste inputs on local stream ARG levels, whereas the majority of ARGs in this tropical river were transported downstream during the wet-season, possibly due to re-entrainment of ARG from sediments.
许多研究已经量化了世界各地河流和溪流中的抗生素耐药基因 (ARG)，并表明不同的污染物排放与当地 ARG 水平的增加之间存在显著关系。然而，大多数研究都没有考虑环境流动条件，而这些条件在热带国家可能会有很大的变化。在这里，在旱季和雨季对水柱状和沉积物样本中的 ARG 进行了量化，以评估季节性和其他因素如何影响阿尔门德雷斯河（古巴哈瓦那）的 ARG 向下游的传输。在两个季节都对八个地点进行了采样并估计了溪流流量；qPCR 用于量化四种四环素、两种红霉素和三种β-内酰胺耐药基因。与旱季相比，雨季样本中的 ARG 浓度更高，加上更高的流量，表明雨季下游的 ARG 传输量更大。然而，与雨季相比，旱季水柱状 ARG 水平的空间变异性更大，污水排放口的临近强烈影响当地的 ARG 水平。结果证实，旱季采样提供了一个有用的画面，说明个别废物输入对当地溪流 ARG 水平的影响，而在这条热带河流中，大多数 ARG 在雨季被向下游输送，这可能是由于从沉积物中重新夹带 ARG 所致。
