Karkman Antti, Johnson Timothy A, Lyra Christina, Stedtfeld Robert D, Tamminen Manu, Tiedje James M, Virta Marko
Department of Food and Environmental Sciences, University of Helsinki, Finland
Center for Microbial Ecology, Michigan State University, East Lansing, MI, USA.
FEMS Microbiol Ecol. 2016 Mar;92(3). doi: 10.1093/femsec/fiw014. Epub 2016 Jan 31.
Antibiotic resistance among bacteria is a growing problem worldwide, and wastewater treatment plants have been considered as one of the major contributors to the dissemination of antibiotic resistance to the environment. There is a lack of comprehensive quantitative molecular data on extensive numbers of antibiotic resistance genes (ARGs) in different seasons with a sampling strategy that would cover both incoming and outgoing water together with the excess sludge that is removed from the process. In order to fill that gap we present a highly parallel quantitative analysis of ARGs and horizontal gene transfer potential over four seasons at an urban wastewater treatment plant using a high-throughput qPCR array. All analysed transposases and two-thirds of primer sets targeting ARGs were detected in the wastewater. The relative abundance of most of the genes was highest in influent and lower in effluent water and sludge. The resistance profiles of the samples cluster by sample location with a shift from raw influent through the final effluents and dried sludge to the sediments. Wastewater discharge enriched only a few genes, namely Tn25 type transposase gene and clinical class 1 integrons, in the sediment near the discharge pipe, but those enriched genes may indicate a potential for horizontal gene transfer.
细菌中的抗生素耐药性是一个在全球范围内日益严重的问题，污水处理厂被认为是抗生素耐药性传播到环境中的主要贡献者之一。目前缺乏关于不同季节大量抗生素耐药基因（ARGs）的全面定量分子数据，且尚无一种采样策略能够同时涵盖进水、出水以及处理过程中排出的剩余污泥。为了填补这一空白，我们使用高通量qPCR阵列对城市污水处理厂四个季节的ARGs和水平基因转移潜力进行了高度平行的定量分析。在废水中检测到了所有分析的转座酶以及三分之二靶向ARGs的引物组。大多数基因的相对丰度在进水最高，在出水和污泥中较低。样品的耐药谱按样品位置聚类，从原进水经过最终出水、干污泥到沉积物呈现出一种变化趋势。废水排放仅在排放管附近的沉积物中富集了少数几个基因，即Tn25型转座酶基因和临床1类整合子，但这些富集的基因可能表明存在水平基因转移的潜力。
