摘要

制药废水处理厂（PWWTPs）接受含有极高抗生素水平的废水，被认为是环境中抗生素耐药性发展的潜在热点。为了评估抗生素抗性基因（ARG）的流行和命运，在中国东南部的六个PWWTP中进行了六次抽样调查。使用实时定量检测不同PWWTP（PWWTP A：林可酰胺; PWWTP B：氨基糖苷类和大环内酯类; PWWTP C：喹诺酮类; PWWTP D：大环内酯类和喹诺酮类; PWWTP E：头孢菌素类; PWWTP F：喹诺酮类和大环内酯类）聚合酶链式反应（PCR），根据产生的抗生素类型。最终流出物中典型的ARG亚型的水平范围为（1.03±0.91）×101至（6.78±0.21）×107拷贝/ mL。流出物中ARGs的绝对丰度占六种PWWTPs流失量的0％-577％，中值为6％。大部分ARG被输送到脱水污泥中，浓度从（1.38±0.21）×105到（6.84±0.43）×1010 copies / g干重（dw）。在不同的处理单元中（生物单元之前/之后），除了在PWWTP C中的移动床生物膜反应器（MBBR）中的强烈衰减之外，没有观察到ARG的增殖或衰减的明显趋势。通过相关分析，研究表明，PWWTP内的细菌丰度和抗生素浓度影响相关ARG的命运，这可能主要与相应ARG的内在抗性机制有关。大环内酯ARGs倾向于位于质粒和转座子中，与大环内酯类抗生素总浓度呈弱相关，但与16S rRNA浓度强烈正相关。此外，发酵废水中的ARG浓度显着高于化学合成和制备废水。这是中国东南部制药废水处理厂（PWWTPs）极高水平抗生素选择压力下抗生素抗性基因行为的首次综合研究。

Pharmaceutical wastewater treatment plants (PWWTPs), which receive wastewater containing extremely high levels of antibiotics, are regarded as potential hot spots for antibiotic-resistance development in the environment. Six sampling campaigns in six PWWTPs in Southeastern China were carried out to assess the prevalence and fate of antibiotic resistance genes (ARGs). Different genes were monitored in different PWWTPs (PWWTP A: lincosamides; PWWTP B: aminoglycosides and macrolides; PWWTP C: quinolones; PWWTP D: macrolides and quinolones; PWWTP E: cephalosporins; and PWWTP F: quinolones and macrolides) using real-time quantitative polymerase chain reactions (PCRs), according to the antibiotic type produced. The levels of typical ARG subtypes in the final effluents ranged from (1.03 ± 0.91) × 101 to (6.78 ± 0.21) × 107 copies/mL. The absolute abundance of ARGs in effluents accounted for 0%–577% of influents to the six PWWTPs with a median value of 6%. Most of the ARGs are transported to the dewatered sludge, with concentrations from (1.38 ± 0.21) × 105 to (6.84 ± 0.43) × 1010 copies/g dry weight (dw). In different treatment units (before/after biological units), a clear trend of proliferation or attenuation was not observed for the ARGs, aside from a strong attenuation in moving bed bio-film reactor (MBBR) in PWWTP C. Through correlation analyses, this study demonstrated that the bacterial abundance and antibiotic concentrations within the PWWTPs influenced the fate of the associated ARGs, and this was possibly related primarily to the intrinsic resistance mechanisms of corresponding ARGs. Macrolide ARGs, which tend to locate in plasmids and transposons, positively correlate weakly with total macrolide antibiotic concentrations but positively correlate strongly with 16S rRNA concentrations. Furthermore, ARG concentrations in the wastewater from fermentation were significantly higher than in the wastewater from chemical synthesis and preparation. This is the first comprehensive study on the behavior of antibiotic resistance genes under extremely high-level antibiotic selection pressures in pharmaceutical wastewater treatment plants (PWWTPs) in Southeastern China.

https://www.sciencedirect.com/science/article/pii/S0048969717322271