摘要

       制药废水处理厂 (PWWTP) 接收含有极高水平抗生素的废水，被认为是环境中抗生素抗性发展的潜在热点。在中国东南部的 6 个 PWWTP 中进行了 6 次采样活动，以评估抗生素抗性基因 (ARG) 的流行和归宿。使用实时定量监测不同 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；和 PWWTP F：喹诺酮类和大环内酯类）中的不同基因根据产生的抗生素类型，聚合酶链反应 (PCR)。最终流出物中典型 ARG 亚型的水平范围为 (1.03 ± 0.91) × 101 至 (6.78 ± 0.21) × 107 拷贝/mL。出水中 ARGs 的绝对丰度占六个 PWWTP 进水的 0%–577%，中值为 6%。大多数 ARGs 被输送到脱水污泥中，浓度从 (1.38 ± 0.21) × 105 到 (6.84 ± 0.43) × 1010 份/g 干重 (dw)。在不同的处理单元（生物单元之前/之后），除了 PWWTP C 中移动床生物膜反应器 (MBBR) 的强烈衰减外，ARGs 没有观察到明显的增殖或衰减趋势。通过相关分析，这研究表明，PWWTPs 内的细菌丰度和抗生素浓度影响了相关 ARGs 的命运，这可能主要与相应 ARGs 的内在抗性机制有关。大环内酯 ARG 往往位于质粒和转座子中，与总大环内酯抗生素浓度呈微弱正相关，但与 16S rRNA 浓度呈强正相关。此外，发酵废水中的 ARG 浓度显着高于化学合成和制备废水。这是对中国东南地区制药废水处理厂（PWWTPs）在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/abs/pii/S0048969717322271