Department of Chemistry, Faculty of Science, University of Bath, Bath, BA2 7AY, United Kingdom, UK; Department of Analytical, Environmental & Forensic Sciences, School of Population Health & Environmental Sciences, King's College London, London, SE1 9NH, UK.
Department of Chemistry, Faculty of Science, University of Bath, Bath, BA2 7AY, United Kingdom, UK.
Water Res. 2020 Sep 1;182:116015. doi: 10.1016/j.watres.2020.116015. Epub 2020 Jun 6.
This study provides an insight into the prevalence of (fluoro)quinolones (FQs) and their specific quinolone qnrS resistance gene in the Avon river catchment area receiving treated wastewater from 5 wastewater treatment plants (WWTPs), serving 1.5 million people and accounting for 75% of inhabitants living in the catchment area in the South West of England.. Ofloxacin, ciprofloxacin, nalidixic acid and norfloxacin were found to be ubiquitous with daily loads reaching a few hundred g/day in wastewater influent and tens of g/day in receiving waters. This was in contrast to other FQs analysed: flumequine, nadifloxacin, lomefloxacin, ulifloxacin, prulifloxacin, besifloxacin and moxifloxacin, which were hardly quantified. Enantiomeric profiling revealed that ofloxacin was enriched with the S-(-)-enantiomer, likely deriving from its prescription as the more potent enantiomerically pure levofloxacin, alongside racemic ofloxacin. While ofloxacin's enantiomeric fraction (EF) remained constant, high stereoselectivity was observed in the case of its metabolite ofloxacin-N-oxide. The removal efficiency of quinolones during wastewater treatment at 5 WWTPs utilising either trickling filters (TF) or activated sludge (AS), was compound and wastewater treatment process dependent, with AS providing better efficiency than TF. The qnrS resistance gene was ubiquitous in wastewater. Its removal was WWTP treatment process dependent with TF performing best and resulting in significant removal of the gene (from 28 to 75%). AS underperformed with only 9% removal in the case of activated sludge and actual increase in the gene copy number within sequencing batch reactors (SBRs). Interestingly, the data suggests that higher removal of antibiotics could be linked with high prevalence of the gene (SBR and WWTP E) and vice versa, low removal of antibiotic is correlated with lower prevalence of the gene in wastewater effluent (TF, WWTP B and D). This is especially prominent in the case of ofloxacin and could indicate that AS might be facilitating antimicrobial resistance (AMR) prevalence to higher extent than TF. Wastewater-based epidemiology (WBE) was also applied to monitor any potential misuse (e.g. direct disposal) of FQs in the catchment. In most cases higher use of antibiotics with respect to official statistics (i.e. ciprofloxacin, ofloxacin) was observed, which suggests that FQs management practice require further attention.
本研究深入探讨了在接受来自 5 家污水处理厂（WWTP）处理废水的阿冯河集水区中，氟喹诺酮类药物（FQs）及其特定喹诺酮 qnrS 耐药基因的流行情况。该集水区为英格兰西南部的 150 万居民提供服务，占集水区居民的 75%。研究发现，氧氟沙星、环丙沙星、萘啶酸和诺氟沙星普遍存在，每日废水进水负荷达数百克/天，接收水中负荷达数十克/天。这与其他分析的 FQs 形成对比：氟甲喹、那氟沙星、洛美沙星、乌洛沙星、普鲁沙星、贝西沙星和莫西沙星几乎无法定量。对映体分析表明，氧氟沙星富集 S-（-）对映体，可能源自其作为更有效力的对映体纯左旋氧氟沙星的处方，以及外消旋氧氟沙星。尽管氧氟沙星的对映体分数（EF）保持不变，但在其代谢物氧氟沙星-N-氧化物的情况下观察到高立体选择性。在利用滴滤池（TF）或活性污泥（AS）的 5 家 WWTP 中，喹诺酮类药物在废水处理过程中的去除效率是复杂的，且取决于废水处理工艺，其中 AS 的效率优于 TF。qnrS 耐药基因在废水中普遍存在。其去除取决于 WWTP 处理工艺，TF 的效果最好，导致基因的大量去除（从 28%到 75%）。AS 的表现较差，在活性污泥中仅去除 9%，而在序列间歇式反应器（SBR）中基因拷贝数实际上增加。有趣的是，数据表明，抗生素的高去除率可能与基因的高流行率有关（SBR 和 WWTP E），反之亦然，废水出水抗生素的低去除率与基因的低流行率有关（TF、WWTP B 和 D）。这在氧氟沙星的情况下尤为明显，这表明 AS 可能比 TF 更有利于促进抗生素耐药性（AMR）的流行。还应用基于废水的流行病学（WBE）来监测集水区中氟喹诺酮类药物的任何潜在误用（例如直接处置）。在大多数情况下，与官方统计数据（即环丙沙星、氧氟沙星）相比，观察到抗生素的使用更高，这表明氟喹诺酮类药物管理实践需要进一步关注。
