Papers - SUZUKI Yoshihiro
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Persistence of Antibiotic-Resistant Escherichia coli Strains Belonging to the B2 Phylogroup in Municipal Wastewater under Aerobic Conditions Reviewed
Xie, H., Ogura, Y. and Suzuki, Y.
Antibiotics 11 ( 2 ) 2022.2
Authorship：Last author, Corresponding author Language：English Publishing type：Research paper (scientific journal)
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Antibiotic-resistant Escherichia coli isolated from dairy cows and their surrounding environment on a livestock farm practicing prudent antimicrobial use Reviewed
Suzuki, Y., Hiroki, H., Xie, H., Nishiyama, M., Sakamoto, S.H., Uemura, R., Nukazawa, K., Ogura, Y., Watanabe, T. and Kobayashi, I.
International Journal of Hygiene and Environmental Health 240 113930 2022.1
Authorship：Lead author, Corresponding author Language：English Publishing type：Research paper (scientific journal)
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Hydrological modeling to assess watershed-scale flow alterations induced by dams and climate change Reviewed
Mineda H., Nukazawa K., Tanimura Y., Suzuki Y.
Proceedings of the IAHR World Congress 1537 - 1546 2022
Publishing type：Research paper (scientific journal) Publisher：Proceedings of the IAHR World Congress
Hydrological alterations can reduce aquatic biodiversity by disrupting the natural flow regimes that characterize the life cycles oforganisms. However, past studies have faced difficulties in quantifying the impacts of dams and climate change, which are major drivers of hydrological alterations. Here, we aimed to evaluate and compare the flow regime alterations caused by dams and climate change throughout the Omaru River catchment, Japan, using a distributed hydrological model. First, to assess the impacts ofdam and climate change independently, we performed runoff analyses using either dam discharge orfuture climatic data (two future periods χ three representative concentration pathways; RCPs). Subsequently, we derived indicators of hydrologic alterations (İHA) to quantify changes in flow alterations by comparing them to İHA under natural conditions (i.e., without dam or climate change data). The runoff analyses showed high reproducibility throughout the study period (Nash-Sutcliffe efficiency = 0.921-0.964). We found that dams altered flow regimes more than climate change, especially under conservative RCP scenarios (RCP2.6 and RCP4.5). However, on a catchment-scale standpoint, climate change induced wider ranges of flow alterations, such as low flow metrics along the tributaries and uppermost main stem, suggesting a watershed-level shrinkage in important corridors of aquatic organisms by reducing upstream length and water level. We also observed that the altered flow regimes by water withdrawals were ameliorated by the confluence of tributaries and downstream hydropower outflows. Our approach, which used a distributed hydrological model, developed a better understanding of flow alterations by dams and climate change.
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Enhancement of sunlight irradiation for wastewater disinfection by mixing with seawater Reviewed
uzuki, Y., Uno, M., Nishiyama, M., Nukazawa, K. and Masago, Y.
Journal of Water and Health 19 ( 5 ) 836 - 845 2021.10
Authorship：Lead author, Corresponding author Language：English Publishing type：Research paper (scientific journal)
DOI： 10.2166/wh.2021.153
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Plant debris are hotbeds for pathogenic bacteria on recreational sandy beaches Reviewed
Suzuki, Y., Shimizu, H., Kuroda, T., Takada, Y. and Nukazawa, K.
Scientifc Reports 11 11496 2021.6
Language：English Publishing type：Research paper (scientific journal)
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Comparison of antibiotic resistance profile of Escherichia coli between pristine and human-Impacted sites in a river Reviewed
Nishimura, E., Nishiyama, M., Nukazawa, K. and Suzuki, Y.
Antibiotics 10 575 2021.5
Language：English Publishing type：Research paper (scientific journal)
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都城盆地における地下水中の硝酸性窒素濃度と降水量の関係分析 Reviewed
平岡透, 中川啓, 野中尋史, 廣田雅春, 鈴木祥広
水文・水資源学会誌 34 ( 5 ) 303 - 310 2021.5
Authorship：Last author Language：Japanese Publishing type：Research paper (scientific journal)
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Mineralogical fingerprinting to characterize spatial distribution of coastal and riverine sediments in southern Japan Reviewed
Nukazawa, K., Itakiyo, T., Ito, K., Sato, S., Oishi, H. and Suzuki, Y.
Catena 203 105323 2021.3
Language：English Publishing type：Research paper (scientific journal)
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土地利用情報を加えた時空間分析による地下水中の硝酸性窒素濃度の補間 Reviewed
平岡透, 中川啓, 野中尋史, 廣田雅春, 鈴木祥広
水文・水資源学会誌 34 ( 3 ) 193 - 203 2021.3
Language：Japanese Publishing type：Research paper (scientific journal)
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Groundwater nitrogen response to regional land-use management in South Japan Reviewed International coauthorship
Yu, Z.-Q., Nakagawa, K., Berndtsson, R., Hiraoka, T. and Suzuki, Y.
Environmental Earth Sciences 80 ( 18 ) 2021
Authorship：Last author Language：English Publishing type：Research paper (scientific journal)
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Gradients of flow regulation shape community structures of stream fishes and insects within a catchment subject to typhoon events Reviewed
Nukazawa, K., Shirasaka, K., Kajiwara, S., Saito, T., Irie, M. and Suzuki, Y.
Science of The Total Environment 748 141398 2020.12
Language：English Publishing type：Research paper (scientific journal)
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Ogura Y., Ueda T., Nukazawa K., Hiroki H., Xie H., Arimizu Y., Hayashi T., Suzuki Y.
Scientific Reports 10 ( 1 ) 2020.12
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Scientific Reports
The dissemination of antimicrobial-resistant bacteria in environmental water is an emerging concern in medical and industrial settings. Here, we analysed the antimicrobial resistance of Escherichia coli isolates from river water and sewage by the use of a combined experimental phenotypic and whole-genome-based genetic approach. Among the 283 tested strains, 52 were phenotypically resistant to one or more antimicrobial agents. The E. coli isolates from the river and sewage samples were phylogenetically indistinguishable, and the antimicrobial-resistant strains were dispersedly distributed in a whole-genome-based phylogenetic tree. The prevalence of antimicrobial-resistant strains as well as the number of antimicrobials to which they were resistant were higher in sewage samples than in river samples. Antimicrobial resistance genes were more frequently detected in strains from sewage samples than in those from river samples. We also found that 16 river isolates that were classified as Escherichia cryptic clade V were susceptible to all the antimicrobials tested and were negative for antimicrobial resistance genes. Our results suggest that E. coli strains may acquire antimicrobial resistance genes more frequently and/or antimicrobial-resistant E. coli strains may have higher rates of accumulation and positive selection in sewage than in rivers, irrespective of their phylogenetic distribution.
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Antimicrobial resistance is more prevalent in various lineages of Escherichia coli strains isolated from sewage than in those from rivers Reviewed
Ogura, Y., Ueda, T., Nukazawa, K., Hiroki, H., Xie, H., Arimizu, Y., Hayashi, T. and Suzuki, Y.
Scientific Reports 10 17880 2020.10
Language：English Publishing type：Research paper (scientific journal)
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高濁度水への環境DNA法の適用に向けたろ過・濃縮手法の基礎的検討 Reviewed
糠澤桂, 深川柊, 鈴木祥広
土木学会論文集G（環境） 76 ( 5 ) I_19 - I_26 2020.9
Language：Japanese Publishing type：Research paper (scientific journal)
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分布型流出モデルを用いた小丸川水系におけるダム・堰による流況改変の縦断的評価 Reviewed
峯田陽生, 糠澤桂, 中尾彰吾, 鈴木祥広
土木学会論文集G（環境） 76 ( 5 ) I_65 - I_74 2020.9
Language：Japanese Publishing type：Research paper (scientific journal)
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Jikumaru A., Ishii S., Fukudome T., Kawahara Y., Iguchi A., Masago Y., Nukazawa K., Suzuki Y.
Journal of Bioscience and Bioengineering 130 ( 1 ) 76 - 81 2020.7
Publishing type：Research paper (scientific journal) Publisher：Journal of Bioscience and Bioengineering
The quantification of pathogens is important for assessing water safety and preventing disease outbreaks. Culture-independent approaches, such as quantitative PCR (qPCR) and digital PCR (dPCR), are useful techniques for quantifying pathogens in water samples. However, since pathogens are usually present at low concentrations in water, it is necessary to concentrate microbial cells before extracting their DNA. Many existing microbial concentration methods are inefficient or take a long time to perform. In this study, we applied a coagulation and foam separation method to concentrate environmental water samples of between 1000 and 5000 mL to 100 μL of DNA (i.e., a 1–5 × 104-fold concentration). The concentration process took <1 h. The DNA samples were then used to quantify various target pathogens using dPCR. One gene, the Shiga toxin gene (stx2) of Shiga toxin-producing Escherichia coli, was detected at 32 copies/100 mL in a river water sample. The coagulation and foam concentration method followed by dPCR reported herein is a fast, sensitive, and reliable method to quantify pathogen genes in environmental water samples.
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Are bacteria potential sources of fish environmental DNA? Reviewed
Nukazawa, K., Akahoshi, K., Suzuki, Y.
PLoS One 15 ( 3 ) e0230174 2020.3
Language：English Publishing type：Research paper (scientific journal)
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Fast, sensitive, and reliable detection of waterborne pathogens by digital PCR after coagulation and foam concentration Reviewed
Jukumaru, A., Ishii, S., Fukudome, T., Kawahara, Y., Iguchi, A., Masago, Y., Nukazawa, K., Suzuki, Y.
Journal of Bioscience and Bioengineering 130 ( 1 ) 76 - 81 2020.2
Language：English Publishing type：Research paper (scientific journal)
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Preliminary assessment of the impacts of sediment sluicing events on stream insects in the Mimi River, Japan Reviewed
Nukazawa, K., Kajiwara, S., Saito, T., Suzuki, Y.
Ecological Engineering 145 105726 2020.1
Language：English Publishing type：Research paper (scientific journal)
Dam sedimentation is a crucial issue that interferes with flood control and electric power generation. To address this, sediment dredging, bypass tunnel, flushing, and sluicing have been applied. Despite the potential impacts of these operations on stream environments, few studies have explored the environmental/ecological consequences of such regime shifts in sediment dynamics. Specifically, impacts of sediment sluicing on stream fauna have never been reported. This study assessed primary impacts of sediment sluicing events operated with the two cascade dams (the Saigo and Ouchibaru Dams) on stream insects in the lower Mimi River, Japan. The sediment sluicing, accompanied by a major flooding event in the river, was first operated in September 2017. Stream insect data downstream of the four cascade dams, including the two sluicing dams and a reference river, were collected yearly or biyearly in winter and summer from 2010 to 2018. Following the initiation of retrofitting the Saigo Dam for optimizing sediment sluicing, a downstream reach of the dam experienced marked perturbations in terms of both individual density and species richness. The density and richness dramatically decreased and the community significantly differed in winter 2017 from pre-impact conditions. The density, richness, and com- munity composition subsequently recovered in winter 2018, even after the sediment sluicing impact, suggesting that the anticipated negative ecological impacts of the sluicing are limited. Non-metric multidimensional scaling and permutational multivariate analysis of variance revealed distinct differences in communities between summer and winter samples at non-regulated sites or sites farther downstream of the dam that are characterized by fewer Simuliidae in summer and relatively abundant Heptageniidae. This could serve as a reference for assessments of ecological consequences of sediment sluicing in the region.
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Growth and antibiotic resistance acquisition of Escherichia coli in a river that receives treated sewage effluent Reviewed
Suzuki, Y., Hashimoto, R., Xie, H., Nishimura, E., Nishiyama, M., Nukazawa, K., Ishii, S.
Science of the Total Environment 690 696 - 704 2019.8
Language：English Publishing type：Research paper (scientific journal)