| Project/Area Number |
18K07133
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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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| Review Section |
Basic Section 49050:Bacteriology-related
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| Research Institution | Kanazawa University |
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Principal Investigator |
Ogura Kohei 金沢大学, 新学術創成研究機構, 助教 (00586612)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
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| Keywords | レンサ球菌 / 病原性 / 糖尿病 / ヒアルロン酸 / 細菌感染 / SDSE / ゲノム解析 / 病原因子 / G群レンサ球菌 / C群レンサ球菌 / 高齢者感染 |
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| Outline of Final Research Achievements |
Streptococcus dysgalactiae subsp. equisimilis (SDSE) causes severe invasive streptococcal infections, especially in elderly people and patients with diabetic mellitus. Although SDSE possesses a genome showing about 70% identity to S. pyogenes's one, it remained unclear how SDSE exhibits pathogenicity. Our purpose in this study was to determine pathogenicity characteristics of SDSE. The survival rates of mice injected with SDSE were significantly lower in mice (db/db) with type 2 diabetes compared with non-diabetic mice. Injection of db/db mice with SDSE increased the concentrations of IL-6. SDSE released dramatically high concentrations of hyaluronate-degrading enzymes (hylauronate lyase). We found the lyase plays important roles in nutrient acquisition from host skins, followed by the bacterial pathogenicity damaging host tissues. We revealed that two prevalent types of SDSE isolates exhibited different characteristics in cell wall structures, anti-phagocytosis, and attachment.
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| Academic Significance and Societal Importance of the Research Achievements |
高齢者や基礎疾患保有者に対して高い病原性を示すStreptococcus dysgalactiae subsp. equisimilis (SDSE) については、これまではS.pyogenes に似た性状を示す菌であると考えられていたが、本研究でSDSEが固有の特性を有することが明らかになった。SDSEが糖尿病モデルマウスに対してS. pyogenesと大きく異なる病原性を示すこと、SDSEが人の皮膚ヒアルロン酸を急速に分解し栄養とすること、その他様々なSDSEの新規な特徴を見出した。本研究によって得られた知見は、高病原性レンサ球菌SDSEが引き起こす感染症全容解明に貢献するものである。
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