摘要

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性健康问题。细菌的ARGs可以通过流动遗传因子进行调动，最近的研究表明噬菌体和噬菌体衍生的颗粒等对ARGs的环境传播中发挥作用。ARGs在水体的细菌和噬菌体组分中含量丰富，为了成功地转移ARGs，它们在这些环境中的持久性至关重要。在本研究中，使用天然存在于原始废水的细菌和噬菌体级的三种ARGs ( blaTEM，blaCTX - Mand sul1 )来评价ARGs在不同温度( 4℃、22℃、37℃)和pH值( 3、7和9 )以及在各种消毒处理(热处理、氯化和UV)和自然灭活后在中间粘粒中的持久性。基因拷贝( GC)采用定量PCR方法进行检测；然后对它们的对数归约和数间差异的显著性进行分析。所有处理后，ARGs持续了很长一段时间的减少量最小。一般来说，它们在噬菌体组分比在细菌组分中有更大的持久性。比较表明，ARGs在可培养大肠杆菌和感染性噬菌体减少到检测极限以下的条件下持续存在。ARGs的流行，特别是在噬菌体中的流行，对ARGs的传播和它们与新细菌背景的结合构成了威胁，这可能导致出现新的抗性克隆。

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-Mand 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.

http://www.sciencedirect.com/science/article/pii/S0043135416301336