Contribution of type 1 pilus to the colonization of Streptococcus pneumoniae

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K08828
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 54030:Infectious disease medicine-related
• Research Institution: Tokyo Medical University
• Principal Investigator: Miyazaki Haruko 東京医科大学, 医学部, 准教授 (10527948)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: type 1 pilus / 肺炎球菌 / 付着因子 / ワクチン

Outline of Final Research Achievements

The purpose of this study was to analyze the function of type 1 pilus（T1P）in the colonization of Streptococcus pneumoniae serotype 35B and its contribution to drug resistance. Among clinical isolates of serotype 35B, clonal complex (CC) 558 strains carrying the T1P gene were used to generate T1P-deficient strains by homologous recombination, and their adherence to human alveolar epithelial cells and drug sensitivity were compared with those of the parental strains.
(1) Adherence to cells: Although the degrees of cell adhesion were strain-dependent, the contribution of T1P to adhesion to host cell was suggested. (2) Effect on antimicrobial susceptibility: No obvious difference in antimicrobial susceptibility was observed between the parental and T1P-deficient strains, suggesting that T1P may not be involved in the drug resistance mechanism.

Free Research Field

微生物学、感染症学

Academic Significance and Societal Importance of the Research Achievements

これまでの検討によって、研究計画で問いとして挙げた1）非ワクチン血清型の中でも血清型35Bの検出が定期接種開始後に増加した原因としてT1Pにより定着しやすいことが関与するのか。　2）T1Pは薬剤感受性に影響を与えるのか。に対して考察することができた。これらの情報は肺炎球菌感染症の今後のワクチン開発や治療への参考となると考える。
研究結果は学会で発表予定であり、また、論文を作成して雑誌に投稿中である。