Bydalek Franciszek, Webster Gordon, Barden Ruth, Weightman Andrew J, Kasprzyk-Hordern Barbara, Wenk Jannis
Department of Chemical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, UK; Water Innovation and Research Centre (WIRC), University of Bath, Bath BA2 7AY, UK; GW4 NERC CDT in Freshwater Biosciences and Sustainability, Cardiff University, Cardiff CF10 3AX, UK; Microbiomes, Microbes and Informatics Group, Organisms and Environment Division, School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
Microbiomes, Microbes and Informatics Group, Organisms and Environment Division, School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
Water Res. 2023 May 15;235:119936. doi: 10.1016/j.watres.2023.119936. Epub 2023 Apr 3.
Microplastics in wastewater are colonized by biofilms containing pathogens and antimicrobial resistance (AMR) genes that can be exported into receiving water bodies. This study investigated establishment and changes in microplastic-associated biofilm and AMR during a conventional full-scale 2100 population equivalent wastewater treatment process combined with a free water surface polishing constructed wetland. Sequential microplastic colonization experiments were conducted at different stages of the wastewater treatment process, including in raw sewage, treated effluent and the constructed wetland. Two scenarios were tested in which the constructed wetland served as either (i) a polishing step or (ii) as primary recipient of sewage inoculated microplastics. Bacterial 16S rRNA gene sequencing was carried out for qualitative bacterial community analysis. qPCR was applied for quantitative analysis of AMR genes (sul1, ermB, tetW, intiI1), bacterial biomass (16S rRNA) and a human fecal marker (HF183). Microbial diversity on microplastics increased with incubation time. The initial sewage-derived biofilm composition changed more significantly in the wastewater effluent compared to the constructed wetland. Pathogen and AMR load decreased by up to two orders of magnitude after coupled conventional and constructed wetland treatment, while less impact was observed when sewage-inoculated microplastic material was directly transferred into the constructed wetland. Aeromonas, Klebsiella, and Streptococcus were key pathogenic genera correlated with AMR in microplastic-associated biofilms. Despite decreasing trends on human pathogens and AMR load along the treatment process, microplastic-associated biofilms were a considerable potential hotspot for AMR (intI1 gene) and accommodated Cyanobacteria and fish pathogens.
废水中的微塑料被含有病原体和抗微生物耐药性（AMR）基因的生物膜定殖，这些基因可排放到受纳水体中。本研究调查了在传统的2100人口当量全规模废水处理工艺与自由水面抛光人工湿地相结合的过程中，与微塑料相关的生物膜和抗微生物耐药性的建立及变化。在废水处理过程的不同阶段进行了连续的微塑料定殖实验，包括原污水、处理后的出水和人工湿地。测试了两种情景，其中人工湿地分别作为（i）一个抛光步骤或（ii）接种了污水微塑料的主要受纳体。进行细菌16S rRNA基因测序以进行定性细菌群落分析。应用qPCR对AMR基因（sul1、ermB、tetW、intI1）、细菌生物量（16S rRNA）和人类粪便标志物（HF183）进行定量分析。微塑料上的微生物多样性随培养时间增加。与人工湿地相比，废水流出物中最初源自污水的生物膜组成变化更为显著。经过传统处理和人工湿地联合处理后，病原体和AMR负荷降低了多达两个数量级，而当接种了污水的微塑料材料直接转移到人工湿地时，观察到的影响较小。气单胞菌属、克雷伯菌属和链球菌属是与微塑料相关生物膜中的AMR相关的关键致病属。尽管在处理过程中人类病原体和AMR负荷呈下降趋势，但与微塑料相关的生物膜是AMR（intI1基因）的一个相当大的潜在热点，并且容纳了蓝细菌和鱼类病原体。
