Department of Microbiology, University of Barcelona, Diagonal 643. Annex. Floor 0, E-08028 Barcelona, Spain.
Department of Microbiology, University of Barcelona, Diagonal 643. Annex. Floor 0, E-08028 Barcelona, Spain.
Water Res. 2016 May 15;95:11-8. doi: 10.1016/j.watres.2016.03.006. Epub 2016 Mar 3.
The emergence and prevalence of antibiotic resistance genes (ARGs) in the environment is a serious global health concern. ARGs from bacteria can be mobilized by mobile genetic elements, and recent studies indicate that phages and phage-derived particles, among others, could play a role in the spread of ARGs through the environment. ARGs are abundant in the bacterial and bacteriophage fractions of water bodies and for successful transfer of the ARGs, their persistence in these environments is crucial. In this study, three ARGs (blaTEM, blaCTX-M and sul1) that naturally occur in the bacterial and phage fractions of raw wastewater were used to evaluate the persistence of ARGs at different temperatures (4 °C, 22 °C and 37 °C) and pH values (3, 7 and 9), as well as after various disinfection treatments (thermal treatment, chlorination and UV) and natural inactivation in a mesocosm. Gene copies (GC) were quantified by qPCR; then the logarithmic reduction and significance of the differences between their numbers were evaluated. The ARGs persisted for a long time with minimal reductions after all the treatments. In general, they showed greater persistence in the bacteriophage fraction than in the bacterial fraction. Comparisons showed that the ARGs persisted under conditions that reduced culturable Escherichia coli and infectious coliphages below the limit of detection. The prevalence of ARGs, particularly in the bacteriophage fraction, poses the threat of the spread of ARGs and their incorporation into a new bacterial background that could lead to the emergence of new resistant clones.
抗生素耐药基因 (ARGs) 在环境中的出现和流行是一个严重的全球健康问题。细菌中的 ARGs 可以被移动遗传元件转移，最近的研究表明，噬菌体和噬菌体衍生颗粒等可能在 ARGs 通过环境传播中发挥作用。ARGs 在水体的细菌和噬菌体部分中大量存在，为了成功转移 ARGs，它们在这些环境中的持久性至关重要。在这项研究中，使用了三种天然存在于原废水的细菌和噬菌体部分的 ARGs（blaTEM、blaCTX-M 和 sul1）来评估 ARGs 在不同温度（4°C、22°C 和 37°C）和 pH 值（3、7 和 9）下的持久性，以及经过各种消毒处理（热处理、氯化和 UV）和在中观系统中的自然失活后的持久性。通过 qPCR 定量了基因拷贝数（GC）；然后评估了它们数量减少的对数减少和差异的显著性。所有处理后，这些 ARGs 都能长时间保持，减少幅度很小。一般来说，它们在噬菌体部分的持久性比在细菌部分更强。比较表明，在降低可培养大肠杆菌和感染性大肠噬菌体数量至检测限以下的条件下，ARGs 得以持续存在。ARGs 的流行，特别是在噬菌体部分，构成了 ARGs 传播及其整合到新细菌背景中的威胁，这可能导致新的耐药克隆的出现。
