摘要

       本研究调查了磺胺类、四环素类、β-内酰胺类和大环内酯类抗性的 10 个抗生素抗性基因 (ARG) 亚型以及 1 类整合酶基因 (intI1) 的特征。总的来说，使用定性和实时定量聚合酶链反应 (PCR) 在五个全面制药废水处理厂 (PWWTP) 的每个阶段的 24 个样本中监测了这些基因。最终流出物中典型 ARG 亚型的水平范围为 (2.08 ± 0.16) × 103 至 (3.68 ± 0.27) × 106 拷贝/mL。 5个污水处理厂出水中ARGs的绝对丰度仅占进水量的0.6%~59.8%，而大部分ARGs以(9.38±0.73)×107~(4.30±0.81)的浓度被输送到脱水污泥中× 1010 份/克干重 (dw)。通过脱水污泥排放的 ARGs 总负荷比原始进水高 7-308 倍，比最终出水高 16-638 倍。 ARGs 的增殖主要发生在生物处理过程中，如常规活性污泥、循环活性污泥系统 (CASS) 和膜生物反应器 (MBR)，这意味着某些 ARGs 亚型的显着复制可能归因于微生物的生长。在选定的废水处理系统的进水中检测到高浓度的抗生素残留物（范围从 0.14 到 92.2 毫克/升），并且它们在流出物中仍然保持高残留。偏相关分析表明，抗生素浓度与流出物中 ARG 亚型的相关相对丰度之间存在显着相关性。虽然相关性并不能证明因果关系，但这项研究表明，除了细菌生长外，制药污水处理厂中的高抗生素残留可能会影响相关 ARG 亚型的增殖和归宿。

       This study investigated the characteristics of 10 subtypes of antibiotic resistance genes (ARGs) for sulfonamide, tetracycline, β-lactam and macrolide resistance and the class 1 integrase gene (intI1). In total, these genes were monitored in 24 samples across each stage of five full-scale pharmaceutical wastewater treatment plants (PWWTPs) using qualitative and real-time quantitative polymerase chain reactions (PCRs). The levels of typical ARG subtypes in the final effluents ranged from (2.08 ± 0.16) × 103 to (3.68 ± 0.27) × 106 copies/mL. The absolute abundance of ARGs in effluents accounted for only 0.6%–59.8% of influents of the five PWWTPs, while the majority of the ARGs were transported to the dewatered sludge with concentrations from (9.38 ± 0.73) × 107 to (4.30 ± 0.81) × 1010 copies/g dry weight (dw). The total loads of ARGs discharged through dewatered sludge was 7–308 folds higher than that in the raw influents and 16–638 folds higher than that in the final effluents. The proliferation of ARGs mainly occurs in the biological treatment processes, such as conventional activated sludge, cyclic activated sludge system (CASS) and membrane bio-reactor (MBR), implying that significant replication of certain subtypes of ARGs may be attributable to microbial growth. High concentrations of antibiotic residues (ranging from 0.14 to 92.2 mg/L) were detected in the influents of selected wastewater treatment systems and they still remain high residues in the effluents. Partial correlation analysis showed significant correlations between the antibiotic concentrations and the associated relative abundance of ARG subtypes in the effluent. Although correlation does not prove causation, this study demonstrates that in addition to bacterial growth, the high antibiotic residues within the pharmaceutical WWTPs may influence the proliferation and fate of the associated ARG subtypes.
https://www.sciencedirect.com/science/article/abs/pii/S0048969715301042