Department of Environmental and Civil Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan.
Research Center for Environmental Quality Management, Graduate School of Engineering, Kyoto University, 1-2 Yumihama, Otsu, Shiga 520-0811, Japan.
Sci Total Environ. 2021 Aug 1;780:146607. doi: 10.1016/j.scitotenv.2021.146607. Epub 2021 Mar 19.
Although lake water can be used as a source of drinking water and recreational activities, there is a dearth of research on the occurrence and fate of enteric viruses. Over a period of 14 months at six points in 2014-2015, we conducted monthly monitoring of the virological water quality of a Japanese lake. The lake receives effluent from three surrounding wastewater treatment plants and retains water for about two weeks. These features allowed us to investigate the occurrence and fate of viruses in the lake environment. Human enteric viruses such as noroviruses and their indicators (pepper mild mottle virus and F-specific RNA bacteriophage [FRNAPH] genogroups) were quantified by PCR-based assays. Additionally, FRNAPH genogroups were quantified by infectivity-based assays to estimate the degree of virus inactivation. Pepper mild mottle virus, genogroup II (GII) norovirus, and GI-FRNAPH were identified in relatively high frequencies (positive in >40% out of 64 samples), with concentrations ranging from 1.3 × 10 to 2.9 × 10 copies/L. Human enteric viruses and some indicators were not detected and less prevalent, respectively, after April 2015. Principal component analysis revealed that the virological water quality changed gradually over time, but its differences between the sampling points were not apparent. FRNAPH genogroups were inactivated during the warm season (averaged water temperature of >20 °C) compared to the cool season (averaged water temperature of <20 °C), which may have been due to the more severe environmental stresses such as sunlight and water temperature. This suggests that the infection risk associated with the use of the lake water may have been overestimated by the gene quantification assay during the warm season.
尽管湖水可用作饮用水和娱乐活动的来源，但有关肠道病毒的发生和归宿的研究却很少。在 2014 年至 2015 年的 14 个月期间，我们在六个地点每月监测日本湖的病毒水质。该湖接收来自三个周围污水处理厂的废水，并保留约两周的水。这些特征使我们能够调查湖泊环境中病毒的发生和归宿。通过基于 PCR 的检测方法定量检测人类肠道病毒（如诺如病毒及其指示物（辣椒斑驳病毒和 F 特异性 RNA 噬菌体[FRNAPH]基因型））。此外，通过基于感染性的检测方法定量检测 FRNAPH 基因型，以估计病毒失活的程度。相对较高的频率（64 个样本中>40%为阳性）检测到辣椒斑驳病毒，基因型 II（GII）诺如病毒和 GI-FRNAPH，浓度范围为 1.3×10 至 2.9×10 拷贝/L。2015 年 4 月之后，人类肠道病毒和一些指示物分别未被检测到且检出率较低。主成分分析表明，病毒水质随时间逐渐变化，但采样点之间的差异并不明显。与凉爽季节（平均水温<20°C）相比，温暖季节（平均水温>20°C）中 FRNAPH 基因型失活，这可能是由于阳光和水温等更严重的环境压力所致。这表明，在温暖季节，使用基因定量检测法可能高估了与使用湖水相关的感染风险。
