Potential of symbionts in controlling arthropod-borne diseases

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H03118
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 42020:Veterinary medical science-related
• Research Institution: Hokkaido University
• Principal Investigator: Nakao Ryo 北海道大学, 獣医学研究院, 准教授 (50633955)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 吸血性節足動物 / 共生微生物 / マイクロビオーム / マダニ / Coxiella / Francisella / Occidentia / PNA

Outline of Final Research Achievements

Blood-feeding arthropods such as ticks and mosquitoes can carry pathogens to humans and animals. They also harbor a variety of seemingly non-pathogenic microorganisms; however, their diversity and roles have not yet been clearly understood. This study disclosed bacterial microbiomes of ticks from domestic and foreign origins by sequencing 16S ribosomal RNA gene (rDNA). The dominant taxa found in tick bacterial microbiome, including Coxiella, Spiroplasma, and Rickettsia, were further genetically characterized to understand their transmission manners in ticks. The method to explore the tick eukaryotic microbiome was developed by designing a peptide nucleic acid (PNA) clamp method which suppresses amplification of tick 18S rDNA, leading to the first detection of Gregarina in ticks. Collectively, these results provide fundamental information to develop control strategies for vector-borne diseases.

Free Research Field

寄生虫学

Academic Significance and Societal Importance of the Research Achievements

国内外のマダニが保有する微生物叢が明らかになり、Coxiella、Spiroplasma、Rickettsia等の優占細菌群の存在を突き止めた。それら優占細菌群のマダニ体内での役割を解析することで、マダニやマダニ媒介性病原体の制御法開発に向けた研究展開が可能となった。マダニの真核生物叢の解析手法を世界で初めて開発した。その手法を論文として公開したことで、他の研究者も容易に真核生物叢解析が可能となり、これまで全く注目されてこなかったマダニ保有真核生物叢の情報集積が期待できる。これまでに認知されていない病原体や新規微生物の発見につながる可能性があり、学術的、社会的意義は大きい。