Study on the pathogenicity of halitosis-causing agents and development of new method for the treatment
| Project/Area Number |
15390651
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Social dentistry
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| Research Institution | Kagoshima University (2004)
Kyushu University (2003) |
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Principal Investigator |
OHO Takahiko Kagoshima University, Graduate School of Medical and Dental Sciences, Professor, 大学院・医歯学総合研究科, 教授 (50160940)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANO Yoshio Kyushu University, Faculty of Dental Science, Associate Professor, 大学院・歯学研究院, 助教授 (80253459)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥11,900,000 (Direct Cost: ¥11,900,000)
Fiscal Year 2004: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2003: ¥8,800,000 (Direct Cost: ¥8,800,000)
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| Keywords | Halitosis / Volatile sulphur compound / L-cysteine desulfhydrase / Hydrogen sulfide / Pathogenicity / Methyl mercaptan |
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| Research Abstract |
βC-S Lyase catalyzes the α,β-elimination of L-cysteine to hydrogen sulfide, which is one of the main causes of oral malodor and is highly toxic to mammalian cells. We evaluated the capacity of six species of oral streptococci to produce hydrogen sulfide. The crude enzyme extract from S.anginosus had the greatest capacity. However, comparative analysis of amino acid sequences did not detect any meaningful differences in the S.anginosus βC-S lyase. The capacity of S.anginosus purified βC-S lyase to degrade L-cysteine was also extremely high, while its capacity to degrade L-cystathionine was unremarkable. These findings suggest that the extremely high capacity of S.anginosus to produce hydrogen sulfide is due to the unique characteristic of βC-S lyase from that organism.
A gene (cgs) encoding cystathionine γ-synthase was cloned from Streptococcus anginosus, and its protein was purified and characterized. The cgs gene and the immediately downstream lcd gene were shown to be cotranscribed as an operon. HPLC analyses showed that the S.anginosus Cgs not only has cystathionine γ-synthase activity, but also expresses O-acetylhomoserine sulfhydrylase activity. These results suggest that S.anginosus has the capacity to utilize both the transsulfuration and direct sulfhydrylation pathways for homocysteine biosynthesis.
We examined the abscess-inducing ability of native dental plaque in mice, the microbial features of the infectious locus produced by the plaque, and the anti-phagocytic property of microbial isolates. Abscess formation was induced in most mice using different plaque samples. The microbial composition of pus was very simple compared to that of the plaque sample that had induced the abscess. The majority of the isolates belonged to the S.anginosus group, normally a minor component of plaque samples. These results suggest that the pathogenicity of S.anginosus is related to its ability to produce hydrogen sulfide at high level.
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Report
(3 results)
Research Products
(14 results)
