| Project/Area Number |
23590510
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Bacteriology (including Mycology)
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| Research Institution | The University of Tokushima |
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Principal Investigator |
TOMOYASU Toshifumi 徳島大学, ソシオテクノサイエンス研究部, 准教授 (20323404)
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| Co-Investigator(Kenkyū-buntansha) |
TABATA Atushi 徳島大学, 大学院ソシオテクノサイエンス研究部, 助教 (10432767)
NAGAMUNE Hideaki 徳島大学, 大学院ソシオテクノサイエンス研究部, 教授 (40189163)
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| Project Period (FY) |
2011 – 2013
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| Project Status |
Completed (Fiscal Year 2013)
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| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2013: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2012: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2011: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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| Keywords | 連鎖球菌 / 細胞溶解毒素 / 発現制御 / 細胞毒性 / ガラクトース / 病原因子 / グリコシダーゼ / 糖鎖 / CcpA / LacR / 発現調節機構 / 病原性 |
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| Research Abstract |
Streptococcus intermedius secretes intermedilysin(ILY), which is a major virulence factor of this pathogen. We showed that the disruption of lacR in an ILY low-producing strain (PC574) led to higher hemolytic activity, increased transcription of ily and higher cytotoxicity against HepG2 cells, when compared to the parental strain. The direct binding of LacR within the ily promoter region was observed by a DNA probe pull-down assay. Adding galactose or lactose into the medium increased the amount of ILY secreted by PC574 cells.
Furthermore, we studied the lacR nucleotide sequences and the hemolytic activity of 50 strains isolated from clinical infections and 7 strains isolated from dental plaque. Thirteen strains isolated from clinical infections showed high ILY production and 9 strains had one or more point mutations and/or an insertion mutation in LacR, which caused the decline in its function.
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