Investigation of systemic virulence caused by Streptococcus mutans colonization in severe carious lesions

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K17254
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57070:Developmental dentistry-related
• Research Institution: Osaka University
• Principal Investigator: Otsugu Masatoshi 大阪大学, 歯学研究科, 助教 (40803086)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 感染性心内膜炎 / ミュータンスレンサ球菌 / コラーゲン結合タンパク / う蝕 / ラット

Outline of Final Research Achievements

Streptococcus mutans, a major pathogen of dental caries, is also considered to cause infective endocarditis (IE). Collagen-binding protein (CBP) has been identified on cell surfaces of approximately 10% to 20% of S. mutans strains, and is considered to be involved in bacterial pathogenicity for dental caries and IE. In the present study, using a newly developed rat model of severe dental caries, heart valve injury was performed for evaluation of IE. Our experimental results with those animals indicate that CBP-positive S. mutans may be a pathogenic factor for IE by invading from severe dental caries to the bloodstream via exposed pulp space.

Free Research Field

歯学

Academic Significance and Societal Importance of the Research Achievements

近年、口腔細菌が引き起こす全身疾患が注目を集めており、抜歯などの観血的処置によって口腔細菌が遠隔臓器へ到達すると考えられている。本研究では、重度のう蝕が生じることにより口腔細菌がう蝕病変部の歯髄腔より毛細血管を通じて血液循環内に侵入し、全身疾患の病原性に影響を及ぼす可能性を示すことができた。本研究により、口腔細菌が遠隔臓器へと至る新たな経路を提示できただけでなく、全身の健康維持における口腔ケアの重要性を提唱することにつなげられると考えられる。