1
|
Yamanouchi K, Arima H, Sakamoto Y, Kanto K, Itoh K, Tsujiguchi T. Isolation and habitat analysis of Balamuthia mandrillaris from soil. Parasitol Res 2024; 123:163. [PMID: 38499865 DOI: 10.1007/s00436-024-08182-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 03/06/2024] [Indexed: 03/20/2024]
Abstract
Balamuthia mandrillaris is a free-living amoeba that causes meningoencephalitis in mammals. Over 200 cases of infection were reported worldwide, with a fatality rate of over 95%. A clear route of infection was unknown for a long time until a girl died of granulomatous amoebic encephalitis (GAE) in California, USA, in 2003 due to infection with B. mandrillaris detected in a potted plant. Since then, epidemiological studies were conducted worldwide to detect B. mandrillaris in soil and other environmental samples. We previously reported the isolation of B. mandrillaris from the soil in Japan; however, the existing B. mandrillaris culture method with BM3 medium and COS-7 cells was unsuccessful. Therefore, in this study, we aimed to conduct soil analysis to determine the growth conditions of B. mandrillaris. B. mandrillaris-positive soils were defined as soils from which B. mandrillaris was isolated and environmental DNA was PCR-positive. Soils inhabited by B. mandrillaris were alkaline, with high electrical conductivity and characteristics of nutrient-rich soils of loam and clay loam. The results of this study suggest a possible reason for the high prevalence of GAE caused by B. mandrillaris among individuals employed in agriculture-related occupations.
Collapse
Affiliation(s)
- Kanako Yamanouchi
- Department of Bioscience and Laboratory Medicine, Graduate School of Health Sciences, Hirosaki University, 66-1 Hon-Cho, Hirosaki, 036-8564, Japan.
| | - Hiroaki Arima
- Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan
| | - Yamato Sakamoto
- Department of Bioscience and Laboratory Medicine, Graduate School of Health Sciences, Hirosaki University, 66-1 Hon-Cho, Hirosaki, 036-8564, Japan
| | - Kazuki Kanto
- Department of Bioscience and Laboratory Medicine, Graduate School of Health Sciences, Hirosaki University, 66-1 Hon-Cho, Hirosaki, 036-8564, Japan
| | - Katsuhiro Itoh
- Education Center for Disaster and Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-Cho, Hirosaki, 036-8564, Japan
| | - Takakiyo Tsujiguchi
- Education Center for Disaster and Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-Cho, Hirosaki, 036-8564, Japan
| |
Collapse
|
2
|
Liu M, Taira Y, Matsuo M, Orita M, Matsunaga H, Kashiwazaki Y, Xiao X, Takamura N. Temporal variation in environmental radioactivity and radiation exposure doses in the restricted areas around the Fukushima Daiichi Nuclear Power Plant. Sci Rep 2023; 13:22459. [PMID: 38105319 PMCID: PMC10725873 DOI: 10.1038/s41598-023-49821-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023] Open
Abstract
Temporal variation and fluctuation in environmental contamination in Futaba town and Okuma town, the location of the Fukushima Daiichi Nuclear Power Plant (FDNPP), were evaluated based on a car-borne survey conducted from October 2021 to November 2022. Although the environmental radioactivity in the interim storage facility area (ISF) was higher than that in open areas (i.e., the evacuation order lifted areas in Futaba town and the Specific Reconstruction and Regeneration Base area [SRRB] in Okuma town), only minor temporal changes were seen in the ambient dose and detection rate of radiocesium (the proportion of radiocesium detected points per all measuring points) in those areas, respectively. These findings suggest that the observed variations may result from physical decay and environmental remediation. Resuspension caused by human activities and weather could also affect the detection rate of radiocesium. The annual external effective doses in Futaba town and Okuma town were estimated to be at a limited level (< 1 mSv/year). Nevertheless, to help ensure the safety and future prosperity of residents and communities in the affected areas around the FDNPP, long-term follow-up monitoring of temporal exposure dose levels during the recovery and reconstruction phases is extremely important.
Collapse
Affiliation(s)
- Mengjie Liu
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Yasuyuki Taira
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
- Fukushima Global Medical Science Center and Radiation Medical Science Center for the Fukushima Health Management Survey Fukushima Medical University, Fukushima City, Fukushima Prefecture, Japan
| | - Masahiko Matsuo
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Makiko Orita
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
- Fukushima Global Medical Science Center and Radiation Medical Science Center for the Fukushima Health Management Survey Fukushima Medical University, Fukushima City, Fukushima Prefecture, Japan
| | - Hitomi Matsunaga
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Yuya Kashiwazaki
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Xu Xiao
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Noboru Takamura
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan.
| |
Collapse
|
3
|
Cui L, Taira Y, Matsuo M, Orita M, Yamada Y, Takamura N. Environmental Remediation of the difficult-to-return zone in Tomioka Town, Fukushima Prefecture. Sci Rep 2020; 10:10165. [PMID: 32576864 PMCID: PMC7311413 DOI: 10.1038/s41598-020-66726-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 05/26/2020] [Indexed: 11/17/2022] Open
Abstract
Temporal variations in ambient dose rates in a restricted area designated as "difficult-to-return" for residents of Tomioka Town, Fukushima Prefecture were evaluated in a car-borne survey during 2018-2019. The median dose rates in the "Decontaminated area" in the difficult-to-return zone decreased rapidly from 1.0 μSv/h to 0.32 μSv/h; however, the median dose rates in the "Non-decontaminated area" and "Radioactive waste storage area" fluctuated between 1.1-1.4 μSv/h and 0.46-0.61 μSv/h, respectively. The detected rate of the cesium-137 (137Cs) (137Cs-detected points per all measuring points) in the "Decontaminated area" also decreased rapidly from 64% to 6.7%, accompany with decreasing in ambient dose rates. On the other hand, the detection of 137Cs in the "Radioactive waste storage area" and "Non-decontaminated area" decreased from 53% to 17% and 93% to 88%, respectively. We confirmed that the dose rates in the Decontaminated area dramatically decreased due to decontamination work aiming to help residents return home. Moreover, the estimated external exposure dose of workers during the present survey was 0.66 mSv/y in the Decontaminated area and 0.55 mSv/y in the Radioactive waste storage area, respectively. This case of Tomioka Town within the "difficult-to-return zone" may be the first reconstruction model for evaluating environmental contamination and radiation exposure dose rates due to artificial radionuclides derived from the nuclear disaster.
Collapse
Affiliation(s)
- Limeng Cui
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Yasuyuki Taira
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan.
| | - Masahiko Matsuo
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Makiko Orita
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Yumiko Yamada
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| | - Noboru Takamura
- Department of Global Health, Medicine and Welfare, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki City, Nagasaki Prefecture, 852-8523, Japan
| |
Collapse
|