2020 Fiscal Year Annual Research Report
Fate and transport of enteric viruses through unplanned potable reuse
| Project/Area Number |
20F20061
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| Research Institution | The University of Tokyo |
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Principal Investigator |
片山 浩之 東京大学, 大学院工学系研究科(工学部), 教授 (00302779)
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| Co-Investigator(Kenkyū-buntansha) |
VU DUC CANH 東京大学, 工学(系)研究科(研究院), 外国人特別研究員
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| Project Period (FY) |
2020-04-24 – 2022-03-31
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| Keywords | ウイルス / メタゲノム / 下水処理 |
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| Outline of Annual Research Achievements |
We are now focusing on developing a method to identify the presence of potentially infectious viruses in waters by a combination of NGS and viability treatment using a platinum compound, namely cis-dichlorodiammineplatinum (CDDP) (CDDP-NGS). For this purpose, Milli-Q water samples spiked with different genotypes of enteroviruses (4 genotypes with 30 variants) were inactivated by heat (60, 70 and 80oC for 1 min) and subjected to NGS with and without CDDP treatment. When determined by NGS alone, the abundance of target viruses was relatively similar among heat-inactivated samples even at highest temperature (80oC). However, when determined by CDDP-NGS, the abundance of target viruses was different among heat-treated samples. The less abundance of viruses was found in the water sample treated at a higher temperature. Besides, no viruses were detected by CDDP-NGS after treatment at 80oC. The results of CDDP-NGS were found to be consistent with the result of the infectivity assay which is a golden method to detect infectious viruses. The evidence above suggests that CDDP-NGS can be used to investigate the abundance of potentially infectious viruses in water samples. In the next step, we will apply CDDP-NGS method to monitoring the diversity of potentially infectious viruses throughout WWTPs and also investigate the removal of potentially infectious viruses throughout WWTPs for a 1 year period.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
In 2020, my research was slightly affected by COVID-19 because our school had a restriction for doing experiments during the state of national emergency. However, the situation is now getting much better so I can do experiments and focus on my research. My research is going smoothly with the progress as I planned. We have successfully optimized the methodology using CDDP-NGS for detecting potentially infectious viruses from water samples in lab conditions. With these results, we can confidently continue next steps in our research to apply the developed method (CDDP-NGS) to studying abundance of potentially infectious viruses throughout actual wastewater treatment plants.
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| Strategy for Future Research Activity |
On this year, we will focus on two objectives including 1) Monitoring the presence of enteric viruses through the unplanned potable reuse and 2) Investigating the genetic diversity of enteric viruses in the unplanned potable reuse. For the 1st objective, water samples in the unplanned potable reuse in Japan will be collected monthly over 1-year period to investigate the viral fate and transport from wastewater to drinking water. Water samples will be collected before and after WWTP, in river at a different distance downstream from the WWTP discharge point, and before and after DWTP. Then, these samples will be analyzed by normal qPCR and viability qPCR for the presence of target viruses. Effects of seasonal change on the presence of enteric viruses through the unplanned potable reuse will be also evaluated because the percentage of wastewater in river might significantly different between the dry and rainy season. For 2nd objective, the samples positive for the target viruses (in the 1st objective ) will be analyzed by the next-generation sequencing technology to identify the predominant genotype or strains present in wastewater (before and after WWTP),river and drinking water (before and after DWTP).
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