Co-occurrence of integrase 1, antibiotic and heavy metal resistance genes in municipal wastewater treatment plants
Co-occurrence of integrase 1, antibiotic and heavy metal resistance genes in municipal wastewater treatment plants
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DOI：
10.1016/j.watres.2016.02.049
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发表时间：
2016-05-01
期刊：
影响因子：
12.8
通讯作者：
Corno, Gianluca
中科院分区：
文献类型：
--
作者：
Di Cesare, Andrea;Eckert, Ester M.;Corno, Gianluca
人类活动对环境中抗生素耐药性传播和持久性的影响仍远未被了解。耐药性的自然背景受人类活动的影响，污水处理厂是向环境释放抗生素耐药性的主要来源之一。污水处理厂的各种处理方法提供了许多不同的环境条件，可能有利于抗生素耐药性基因(ARGs)的选择，从而使其在环境中的传播有据可查。尽管对不同精氨酸在污水处理厂中的分布进行了深入的研究，但对特定精氨酸选择的生态学和分子机制知之甚少。这项研究调查了不同的ARGs、重金属抗性基因(HMRGs)和一个可移动元件(I类整合子)在三个污水处理厂中的命运。分析了3个污水处理厂不同处理阶段不同遗传标记的丰度及其与影响微生物群落的生物和非生物因素(总有机碳、总氮、原核细胞丰度及其在单细胞和团聚体中的相对分布)的关系。分析了水样中6个ARG(Teta、sulII、Bla(TEM)、Bla(CTXM)、ermB和qnrS)、2个HMRGs(czcA和ARSB)和I类整合子(Int1)的丰度。测量的变量聚集在两个定义明确的组中，第一组包括Teta、ermB、qnrS和不同的生物和非生物因素，第二组围绕基因sulII、czcA、arsb和int1。此外，SulII、HMRGs和INT1的动态变化具有很强的相关性。我们的结果表明，HMRGs在一些ARGs的传播中可能起着关键作用，这种传播是由移动元件介导的，即SulII。重金属污染与ARGs在污水处理厂中扩散的可能性需要进一步的研究，以阐明共选择的机理及其生态，以实现应用处理的去除效率。(C)2016爱思唯尔有限公司。保留所有权利。
The impact of human activities on the spread and on the persistence of antibiotic resistances in the environment is still far from being understood. The natural background of resistances is influenced by human activities, and the wastewater treatment plants (WWTPs) are among the main sources of the release of antibiotic resistance into the environment. The various treatments of WWTPs provide a number of different environmental conditions potentially favoring the selection of antibiotic resistance genes (ARGs) and thereby their well-documented spread in the environment. Although the distribution of different ARGs in WWTPs has been deeply investigated, very little is known on the ecology and on the molecular mechanisms underlying the selection of specific ARGs. This study investigates the fate of diverse ARGs, heavy metal resistance genes (HMRGs) and of a mobile element (the class I integron) in three WWTPs. Abundances of the different genetic markers were correlated to each other and their relation to biotic and abiotic factors (total organic carbon, total nitrogen, prokaryotic cell abundance and its relative distribution in single cells and aggregates) influencing the microbial communities in the different treatment phases in three WWTPs, were investigated. Water samples were analyzed for the abundance of six ARGs (tetA, sulII, bla(TEM), bla(CTXM), ermB, and qnrS), two HMRGs (czcA and arsB), and of the class I integron (int1). The measured variables clustered in two well-defined groups, the first including tetA, ermB, qnrS and the different biotic and abiotic factors, and a second group around the genes sulII, czcA, arsB and int1. Moreover, the dynamics of sulII, HMRGs, and int1 correlated strongly. Our results suggest a potentially crucial role of HMRGs in the spread, mediated by mobile elements, of some ARGs, i.e. sulII. The possibility of a relation between heavy metal contamination and the spread of ARGs in WWTPs calls for further research to clarify the mechanisms of co-selection and their ecology, in order to implement the removal efficiency of the applied treatments. (C) 2016 Elsevier Ltd. All rights reserved.