Clarification of the infection mechanism of normal fungal microbiota

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08394
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental and hygienic pharmacy
• Research Institution: Meiji Pharmaceutical University
• Principal Investigator: Ichikawa Tomoe 明治薬科大学, 薬学部, 講師 (60383288)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 病原真菌 / Trichosporon / トリコスポロン症 / 接着性 / コロニー形態変化

Outline of Final Research Achievements

The study’s aim was to explain the mechanism of infection which is due to normal fungal microbiota. We have examined the ability to adhere as well as the cytotoxicity of Candida spp., which are archetypical pathogenic yeasts, and found that the responsiveness is different depending on the type of host cells and the Candida species. Particularly, C. glabrata selectively adheres to mammalian cells.
Trichosporon asahii, the causative yeast of trichosporonosis, shows different colony morphologies. We have thought that yeast cells cause infection by colony switching when T. asahii cause infection. This study shows that T. asahii is the reason for hemagglutination as well as hemolysis and the ability of hemagglutination was contrasting between colony morphologies. The higher the adhesive colony morphology, the higher the hemagglutination ability.

Free Research Field

微生物学

Academic Significance and Societal Importance of the Research Achievements

特異的な診断法や治療法がないT. asahiiの病原因子の探索を行い、いくつかの病原性状を示した。本研究では、T. asahiiが赤血球を凝集させることを新たに見出した。さらにコロニー形態により赤血球凝集能が異なり、培養プレートによく接着性を示すコロニー形態では赤血球凝集能も高いことが明らかとなり、コロニ形態変化が病原性に関与することを示した。Candidaの接着性や細胞傷害性も菌種により異なることから、これらの因子を同定することで、菌種特異的の新規診断や治療の標的分子となる可能性が示された。