摘要

       抗生素耐药性的出现和传播对人类健康和环境生态系统构成了重大威胁。尽管消毒已被证明可以有效控制病原体的发生，但很少有人致力于揭示消毒对抗生素抗性基因（ARG）传播的潜在影响，特别是对城市污水处理最终消毒出水中的自由生存 ARG 的影响植物（UWWTP）。在这里，我们研究了氯消毒在一年多的全规模 UWWTP 中对细胞外 ARGs (eARGs) 和细胞内 ARGs (iARGs) 发生和浓度的影响。我们报告说，用二氧化氯 (ClO2) 消毒会增加 eARGs 和 iARGs 的浓度。具体而言，氯化优先增加针对大环内酯 (ermB)、四环素 (tetA、tetB 和 tetC)、磺胺 (sul1、sul2 和 sul3)、β-内酰胺 (ampC)、氨基糖苷类 (aph(2')-Id) 的 eARG 丰度、利福平 (katG) 和万古霉素 (vanA) 高达 3.8 倍。同样，氯化后 iARG 的丰度也增加了 7.8 倍。在相关分析方面，氯化前大肠杆菌的丰度与总 eARG 浓度呈强正相关，而较低的温度和较高的铵浓度被认为与 iARG 的浓度相关。这项研究表明，氯消毒可以增加 iARG 和 eARG 的丰度，从而构成抗生素耐药性在环境中传播的风险。

       The emergence and spread of antibiotic resistance has posed a major threat to both human health and environmental ecosystem. Although the disinfection has been proved to be efficient to control the occurrence of pathogens, little effort is dedicated to revealing potential impacts of disinfection on transmission of antibiotic resistance genes (ARGs), particularly for free-living ARGs in final disinfected effluent of urban wastewater treatment plants (UWWTP). Here, we investigated the effects of chlorine disinfection on the occurrence and concentration of both extracellular ARGs (eARGs) and intracellular ARGs (iARGs) in a full-scale UWWTP over a year. We reported that the concentrations of both eARGs and iARGs would be increased by the disinfection with chlorine dioxide (ClO2). Specifically, chlorination preferentially increased the abundances of eARGs against macrolide (ermB), tetracycline (tetA, tetB and tetC), sulfonamide (sul1, sul2 and sul3), β-lactam (ampC), aminoglycosides (aph(2’)-Id), rifampicin (katG) and vancomycin (vanA) up to 3.8 folds. Similarly, the abundances of iARGs were also increased up to 7.8 folds after chlorination. In terms of correlation analyses, the abundance of Escherichia coli before chlorination showed a strong positive correlation with the total eARG concentration, while lower temperature and higher ammonium concentration were assumed to be associated with the concentration of iARGs. This study suggests the chlorine disinfection could increase the abundances of both iARGs and eARGs, thereby posing risk of the dissemination of antibiotic resistance in environments.

https://www.sciencedirect.com/science/article/abs/pii/S004313541830143X