2016 Fiscal Year Final Research Report
Role of a novel secreted glycosidase for pathogenicity of a human-specific pathogenic streptococci.
| Project/Area Number |
26460528
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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 |
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| Research Collaborator |
MATOBA Masaki
KUSAKA Shingo
YAMASAKI Takahiro
CHIBA Shinya
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | レンサ球菌 / 溶血毒素 / グリコシダーゼ / ガラクトース / シアル酸 |
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| Outline of Final Research Achievements |
Streptococcus intermedius (SI) is a member of the normal flora of the human oral cavity and known as an opportunistic human pathogen secreting a cytolysin called intermedilysin (ILY) as a major pathogenic factor. We found a novel glycosidase in this strain which showed 4 glycosidase activities include in β-galactosidase and N-acetylglucosaminidase, and named as MsgA. We also showed MsgA and neuraminidase (NanA) could degrade glycans from glycoprotein into monosaccharides. Interestingly, a strong hemolytic activity mediated by ILY was observed when SI was cultured in fetal bovine serum (FBS) as compared to the standard culture medium. We showed that the reason of this overproduction of ILY was galactose which is released by MsgA and NanA from glycans in FBS. Moreover, addition of human plasma to the culture in FBS appeared to inhibit the stimulatory effect of FBS on ILY. We confirmed that human plasma contains immunoglobulins that can neutralize ILY, MsgA, and NanA activities.
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| Free Research Field |
病原微生物学
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