Analysis of interaction between streptococci and host during bacterial dissemination

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H04369
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Morphological basic dentistry
• Research Institution: Osaka University
• Principal Investigator: Masanobu Nakata 大阪大学, 歯学研究科, 准教授 (90444497)
• Co-Investigator(Kenkyū-buntansha): 川端 重忠 大阪大学, 歯学研究科, 教授 (50273694) ; 岡橋 暢夫 大阪大学, 歯学研究科, 准教授 (40150180) ; 住友 倫子 大阪大学, 歯学研究科, 講師 (50423421) ; 山口 雅也 大阪大学, 歯学研究科, 助教 (00714536)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: レンサ球菌

Outline of Final Research Achievements

Streptococcus sanguinis, a member of commensal oral streptococci, and Streptococcus pneumoniae, responsible for pneumonia and meningitis, belong to the mitis group of streptococci. Members of this streptococcal group are frequently isolated from lesions associated with systemic disease. In this study, results of pilus component analysis led to detection of a new pilus subunit involved in biofilm formation. Furthermore, data obtained by analysis of S. pneumoniae suggested that a change in culture temperature has impact on the profile of proteins secreted from the bacterium, as well as the ability of the organism to adhere to lung epithelial cells. Examinations of a mouse infection model also revealed that culture temperature alteration had effects on bacterial survival rate in mouse blood.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

これまで申請者らが世界で初めて発見した口腔内レンサ球菌Streptococcus sanguinisの線毛について，新たな構成タンパク質を発見し，特定の条件においてバイオフィルム形成を促進することを明らかにした．これらの結果は類似する線毛の解析と生物学的特性の更なる理解に貢献すると考えられる．一方，肺炎球菌は主に高齢者に肺炎や髄膜炎などの侵襲性疾患を起こすため，超高齢社会を迎えた我が国において社会的問題となっている．本研究で明らかにした環境温度の変化により発現量が調節される細菌因子群は肺炎球菌感染症に対する治療標的となる可能性がある．