摘要
      在欧洲、亚洲和北美，废水处理厂（WWTP）已经就抗生素耐药性（AR）元素的发生和命运进行了广泛的调查，如抗生素耐药性基因（ARGs）、移动遗传元素（MGE）以及抗生素耐药性细菌和病原体。然而，巴西城市污水处理厂中AR元素的监测数据很少。本研究采用CAS（常规活性污泥）、UASB/BTF（UASB后接生物滴滤器）和MAS/UV（紫外线消毒阶段的改性活性污泥）三种不同的污水处理方法，研究了三座污水处理厂原水和处理后污水中intI1、五种ARG（sul1、tetA、blaTEM、ermB和qnrB）和16S rRNA的丰度。还评估了细菌多样性和潜在致病群的存在，并提出了遗传标记与细菌种群之间的关联。所有污水处理厂都降低了最终排放到接收水体的遗传标记的负荷，并且没有证据表明它们是废水中抗微生物耐药性扩增的热点，因为在处理过的废水中，细菌种群中intI1和ARGs的丰度没有增加。UASB/BTF表现出与CAS和MAS/UV相似的性能，强化了这种生物处理的卫生和环境优势，广泛应用于温暖气候地区的废水处理。处理后细菌多样性和丰富度增加，废水样本中的细菌群落因集水区和处理类型而异。治疗后潜在致病人群显著减少；然而，与intI1和ARGs的强显著相关性揭示了处理过的废水中潜在的耐多药致病菌（气单胞菌、Arcobacter、肠杆菌、埃希氏志贺氏菌、狭窄单胞菌和链球菌），尽管相对丰度降低。这些结果有助于了解废水处理后ARGs、MGE和潜在致病菌的命运，这可能有助于在不久的将来采取行动，减少它们向巴西水生环境的释放。
Abstract
Wastewater treatment plants (WWTPs) have been widely investigated in Europe, Asia and North America regarding the occurrence and fate of antibiotic resistance (AR) elements, such as antibiotic resistance genes (ARGs), mobile genetic elements (MGEs) and antibiotic resistant bacteria and pathogens. However, monitoring data about AR elements in municipal WWTPs in Brazil are scarce. This study investigated the abundance of intI1, five ARGs (sul1, tetA, blaTEM, ermB and qnrB) and 16S rRNA in raw and treated wastewater of three WWTPs, using different sewage treatments named CAS (Conventional activated sludge), UASB/BTF (UASB followed by biological trickling filter) and MAS/UV (modified activated sludge with UV disinfection stage). Bacterial diversity and the presence of potentially pathogenic groups were also evaluated, and associations between genetic markers and the bacterial populations were presented. All WWTPs decreased the loads of genetic markers finally discharged to receiving water bodies and showed no evidence of being hotspots for antimicrobial resistance amplification in wastewater, since the abundances of intI1 and ARGs within the bacterial population were not increased in the treated effluents. UASB/BTF showed a similar performance to that of the CAS and MAS/UV, reinforcing the sanitary and environmental advantages of this biological treatment, widely applied for wastewater treatment in warm climate regions. Bacterial diversity and richness increased after treatments, and bacterial communities in wastewater samples differed due to catchment areas and treatment typologies. Potential pathogenic population underwent considerable decrease after the treatments; however, strong significant correlations with intI1 and ARGs revealed potential multidrug-resistant pathogenic bacteria (Aeromonas, Arcobacter, Enterobacter, Escherichia-Shigella, Stenotrophomonas and Streptococcus) in the treated effluents, although in reduced relative abundances. These are contributive results for understanding the fate of ARGs, MGEs and potential pathogenic bacteria after wastewater treatments, which might support actions to mitigate their release into Brazilian aquatic environments in the near future.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722038700