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学術研究成果リスト

Detail of Grant Awarded Academic Researches

Project

Evaluation of risk of pathogen infection via contaminated water during recreational activities in the Tamagawa River basin

Academic
Research
No.299
Principal
Investigator
Eiji Haramoto
Affiliation Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
Research
Summary

This study aimed to determine the prevalence of waterborne pathogens (i.e., viruses and protozoa) in the Tamagawa River water. River water samples (2 l each) were subjected to pathogen concentration using the electronegative-membrane vortex method, followed by quantitative detection of viruses and protozoa using real-time PCR and fluorescent microscopy, respectively. During a 14-month survey, human adenovirus, noroviruses GI and GII, Aichivirus, Cryptosporidium oocysts, and Giardia cysts were successfully detected in 22 (52%), 28 (67%), 7 (17%), 23 (55%), 9 (21%), and 25 (60%) of the 42 river water samples, respectively. Compared to the upstream site (Site 1), the prevalence of pathogens was quite high in the midstream and downstream sites (Sites 2 and 3), implying a significant effect of treated sewage on pathogen contamination of the river. Indicator microorganisms such as total coliforms were also detected in high concentrations at Sites 2 and 3. Based on the sequence analysis, a zoonotic genotype of Giardia cysts and waterborne human adenovirus genotypes 40 and 41 were identified in these samples. The electronegative membrane-vortex method successfully concentrated Bacteroidales genomes, suggesting a potential future application of this method to bacteria detection. Among the 3 sites studied, the concentration of probably-infectious pathogens was the highest at Site 2.

Collaborators
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