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合成银纳米粒子对城市污水混合过滤系统中抗生素耐药性和抗生素耐药性基因去除效率的影响

发布者:抗性基因网 时间:2023-06-09 浏览量:395

摘要
      工程纳米颗粒,包括银纳米颗粒,主要通过废水处理系统释放到环境中。了解AgNPs对包括人工湿地在内的废水处理设施中抗生素抗性基因(ARGs)的丰度和去除效率的影响,对公共卫生至关重要。本研究使用定量PCR和宏基因组方法评估了城市污水中增加的(100倍)羽衣甘蓝(蛋白质包被的AgNPs)和离子Ag+对混合CW中抗生素抗性组、整合子整合酶基因和病原体的结构、丰度和去除效率的影响。废水中ARG的丰度和混合系统中ARG去除效率受到较高Ag浓度的显著影响,尤其是在collagol处理的情况下,导致系统废水向环境中排放的ARG增加。过滤器中积累的Ag对处理水中ARGs的绝对和相对丰度的影响比水中Ag含量的影响更为深远。这项研究记录了四环素(tetA、tetC、tetQ)、磺酰胺(sul1、sul2)和氨基糖苷(aadA)抗性基因的相对丰度值显著增加,这些基因经常在羽衣甘蓝的移动遗传元件上发现,在较小程度上,在AgNO3处理的子系统中也发现。响应羽衣甘蓝的存在,质粒和整合素整合酶基因水平升高,特别是intI1,表明AgNPs在促进治疗系统中的水平基因转移中具有重要作用。原核生物群落的致病片段与典型的污水群落相似,在垂直潜流过滤器中记录到病原体和ARG比例之间的强相关性。此外,肠炎沙门氏菌的比例与这些过滤废水中的Ag含量呈正相关。AgNPs对CWs中移动遗传元件携带的显著抗性基因的性质和特征的影响需要进一步研究。
Abstract
Engineered nanoparticles, including silver nanoparticles (AgNPs), are released into the environment mainly through wastewater treatment systems. Knowledge of the impact of AgNPs on the abundance and removal efficiency of antibiotic resistance genes (ARGs) in wastewater treatment facilities, including constructed wetlands (CWs), is essential in the context of public health. This study evaluated the effect of increased (100-fold) collargol (protein-coated AgNPs) and ionic Ag+ in municipal wastewater on the structure, abundance, and removal efficiency of the antibiotic resistome, integron-integrase genes, and pathogens in a hybrid CW using quantitative PCR and metagenomic approaches. The abundance of ARGs in wastewater and the removal efficiency of ARGs in the hybrid system were significantly affected by higher Ag concentrations, especially with collargol treatment, resulting in an elevated ARG discharge of system effluent into the environment. The accumulated Ag in the filters had a more profound effect on the absolute and relative abundance of ARGs in the treated water than the Ag content in the water. This study recorded significantly enhanced relative abundance values for tetracycline (tetA, tetC, tetQ), sulfonamide (sul1, sul2), and aminoglycoside (aadA) resistance genes, which are frequently found on mobile genetic elements in collargol- and, to a lesser extent, AgNO3-treated subsystems. Elevated plasmid and integron-integrase gene levels, especially intI1, in response to collargol presence indicated the substantial role of AgNPs in promoting horizontal gene transfer in the treatment system. The pathogenic segment of the prokaryotic community was similar to a typical sewage community, and strong correlations between pathogen and ARG proportions were recorded in vertical subsurface flow filters. Furthermore, the proportion of Salmonella enterica was positively related to the Ag content in these filter effluents. The effect of AgNPs on the nature and characteristics of prominent resistance genes carried by mobile genetic elements in CWs requires further investigation.

https://www.sciencedirect.com/science/article/abs/pii/S0043135423004220