2015 Fiscal Year Final Research Report
Virulence mechanisms in hypervirulent strains of group A streptococci
| Project/Area Number |
25460545
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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 | Kitasato University |
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Principal Investigator |
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Keywords | 細菌 / 感染症 / CD46 / マウス感染モデル / レンサ球菌 / レンサ球菌毒素性ショック症候群 / 骨破壊 / RANKL |
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| Outline of Final Research Achievements |
Virulent and avirulent strains of group A streptococcus (GAS) emm type 1 were simultaneously isolated from a single patient suffering from streptococcal meningitis. The whole-genome sequencing and comparative genomic analysis revealed the possibility that a spontaneous point mutation in the rocA gene led to the hypervirulent phenotype of emm1 GAS associated with the suppression of covR expression. Meanwhile, the emm1 GAS strain GAS472 was isolated from a patient suffering from streptococcal toxic shock-like syndrome. CD46 transgenic (Tg) mice developed necrotizing fasciitis associated with osteoclast-mediated progressive and severe bone destruction in the hind paws after subcutaneous infection with GAS472. GAS472 infection induced expression of the receptor activator of nuclear factor-κB ligand (RANKL) in heterogeneous bone marrow cells. Therefore, GAS472 infection induced local bone erosion and systemic bone loss in CD46 Tg mice.
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| Free Research Field |
細菌学（含真菌学）
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