Lee Jiyoung, Lee Seungjun, Hu Chenlin, Marion Jason W
Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH, United States.
Department of Food Science and Technology, The Ohio State University, Columbus, OH, United States.
Front Microbiol. 2023 Aug 28;14:1233327. doi: 10.3389/fmicb.2023.1233327. eCollection 2023.
Western Lake Erie is suffering from harmful cyanobacterial blooms, primarily toxic spp., affecting the ecosystem, water safety, and the regional economy. Continued bloom occurrence has raised concerns about public health implications. However, there has been no investigation regarding the potential increase of and antibiotic resistance genes in source water, and disinfection byproducts in municipal treated drinking water caused by these bloom events.
Over 2 years, source water (total = 118) and finished water (total = 118) samples were collected from drinking water plants situated in western Lake Erie (bloom site) and central Lake Erie (control site). Bloom-related parameters were determined, such as microcystin (MC), toxic , total organic carbon, N, and P. Disinfection byproducts (DBPs) [total trihalomethanes (THMs) and haloacetic acids (HAAs)] were assessed in finished water. Genetic markers for , antibiotic resistance genes, and mobile genetic elements were quantified in source and finished waters.
Significantly higher levels of MC-producing were observed in the western Lake Erie site compared to the control site. Analysis of DBPs revealed significantly elevated THMs concentrations at the bloom site, while HAAs concentrations remained similar between the two sites. spp. levels were significantly higher in the bloom site, showing a significant relationship with total cyanobacteria. Abundance of ARGs (Q and 1) and mobile genetic elements (MGEs) were also significantly higher at the bloom site.
Although overall abundance decreased in finished water, relative abundance of ARGs and MGE among total bacteria increased after treatment, particularly at the bloom site. The findings underscore the need for ongoing efforts to mitigate bloom frequency and intensity in the lake. Moreover, optimizing water treatment processes during bloom episodes is crucial to maintain water quality. The associations observed between bloom conditions, ARGs, and , necessitate future investigations into the potential enhancement of antibiotic-resistant bacteria and spp. due to blooms, both in lake environments and drinking water distribution systems.
伊利湖西部正遭受有害蓝藻水华的影响，主要是有毒物种，这对生态系统、水安全和区域经济都产生了影响。水华的持续发生引发了对公共健康影响的担忧。然而，尚未有关于这些水华事件导致原水中蓝藻和抗生素抗性基因以及市政处理后的饮用水中消毒副产物潜在增加的调查。
在两年多的时间里，从位于伊利湖西部（水华发生地）和伊利湖中部（对照地）的饮用水处理厂采集了原水（共118份）和成品水（共118份）样本。测定了与水华相关的参数，如微囊藻毒素（MC）、有毒蓝藻、总有机碳、氮和磷。在成品水中评估了消毒副产物（DBPs）[总三卤甲烷（THMs）和卤乙酸（HAAs）]。对原水和成品水中蓝藻、抗生素抗性基因和可移动遗传元件的基因标记进行了定量分析。
与对照地相比，伊利湖西部站点中产生MC的蓝藻水平显著更高。对消毒副产物的分析表明，水华发生地的THMs浓度显著升高，而两个站点之间的HAAs浓度保持相似。蓝藻水平在水华发生地显著更高，与总蓝藻数量呈显著关系。水华发生地的抗生素抗性基因（Q和1）和可移动遗传元件（MGEs）的丰度也显著更高。
尽管成品水中的总体丰度有所下降，但处理后总细菌中抗生素抗性基因和可移动遗传元件的相对丰度增加，特别是在水华发生地。这些发现强调了持续努力减轻湖泊中水华频率和强度的必要性。此外，在水华事件期间优化水处理工艺对于维持水质至关重要。在水华条件、抗生素抗性基因和蓝藻之间观察到的关联，使得有必要在未来对湖泊环境和饮用水分配系统中因水华导致的抗生素抗性细菌和蓝藻物种潜在增加进行调查。
