2007 Fiscal Year Final Research Report Summary
STUDY ON ANTISEPTIC EFFECT OF SILVER AND COPPER IONS AGAINST LEGIONELLA IN HOT SPRING WATERS
Project/Area Number |
18510035
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Environmental impact assessment/Environmental policy
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Research Institution | Toho University |
Principal Investigator |
KATO Naoyuki Toho University, Faculty of Medicine, Associate Professor (50104154)
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Project Period (FY) |
2006 – 2007
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Keywords | LEGIONELLA / HOT SPRINNG / SILVER ION / COPPER ION / AMOEBA / TROPHOZOITE / CYST / ANTISEPTIC EFFECT |
Research Abstract |
1. We studied the influence of chemical composition of hot springs to the antiseptic effect of silver ion. (1) The antiseptic effect of silver ion delayed according to-increases of chloriide and sulfuric acid ions in hot spring. (2) Some hot spring did not show any antiseptic effect despite enough silver ion concentration. The cause will be attributed to that silver ion formed complex with some kind of hot spring components. 2. Antiseptic effect of silver ion against legionella cells in amoeba or amoeba alone was studied. (1) While legionella cells in amoeba were not killed at the concentration of 0.05 ppm of silver ion, silver ion of 2.5ppm showed an antiseptic effect. (2) Legionella cells in cyst encysted amoeba were not killed even at the concentration of 2.5ppm but did at the concentration of 5ppm. (3) Amoeba cells themselves were not killed by the concentration of-5ppm of silver ion. 3. The concentration of copper ion in an aqueous solution decreased with a rise in pH. In this study
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, particles coated with copper were added into each aqueous solution with different pH at a final concentration of 0.1%and 0.5%, respectively. Eluted copper concentration was different in 0.1% and 0.5%, however there was no difference among different pH in dissolution rate of copper along with the time course. 4. Antiseptic effect of copper ion against legionella cells in amoeba or amoeba alone was studied. (1) The antiseptic duct of copper ion against legionella cells m trophozoite cells was not shown at the concentration of 1ppm, while legionella cells of 76% at 5ppm and 95% at 10ppm were killed, respectively. (2) The legionella cell in cyst form were not killed at the concentration of 1ppm of copper ion as well as in trophozoite cell. Eighty fie % and 94% of legionella cells were killed at the concentration of 5ppm and 10ppm, respectively. (3) Seventy four % and 47% of amoeba cells survived in the copper ion concentration of 5ppm and 10ppm, respectively. 5. In the experiment of antiseptic effect against legionella in copper ion solution with pH7.2, Legionella cells were completely killed at 6h after the addition of 0.5 ppm copper ion. On the other hand, each 0.1% copper solution adjusted. to pH6.0, 7.4 and 8.5 showed all antiseptic effect, and distilled water, tap water and marine water adjusted to copper concentration of 0.1% had also the same effect. The antiseptic effect of hot spring waters against legionella was diversed among each hot spring due to the differences of pH and chemical composition of hot springs. Less
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Research Products
(20 results)
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[Journal Article] 微量元素と温泉2007
Author(s)
加藤 尚之
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Journal Title
Biomed Res Trace Elements 18
Pages: 301-310
Description
「研究成果報告書概要(和文)」より
Peer Reviewed
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[Presentation] 温泉と微量元素2007
Author(s)
加藤 尚之
Organizer
第18回日本微量元素学会(シンポジウム)
Place of Presentation
福井
Year and Date
2007-07-05
Description
「研究成果報告書概要(和文)」より
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