The influence of cervine piroplasma on the onset of bovine piroplasmosis

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K19257
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 42:Veterinary medical science, animal science, and related fields
• Research Institution: Obihiro University of Agriculture and Veterinary Medicine
• Principal Investigator: Yokoyama Naoaki 帯広畜産大学, 原虫病研究センター, 教授 (80301802)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Keywords: シカ / タイレリア / バベシア / マダニ / 牛 / 感染 / リスク

Outline of Final Research Achievements

We demonstrated for the first time that wild deer in Hokkaido are infected with a Theileria species designated Theileria sp. (sika 1) and two Babesia species designated Babesia sp. (sika 1) and Babesia sp. (sika 2). Our findings also suggested that Ixodes persulcatus and Haemaphysalis longicornis, which are widespread in Hokkaido, are potential transmission vectors of these cervine Theileria and Babesia species. Interestingly, these parasite species were not detected in cattle from the same regions where the infected deer were found. In conclusion, our findings suggest that the risk of being infected with cervine Babesia and Theileria species is very low in cattle.

Free Research Field

獣医学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果により、野生動物に寄生する新たなピロプラズマ原虫の存在と生活環の一部が学術的に明らかとなった。また、それら原虫を迅速に検出できるPCR法やLAMP法など新たな診断技術の開発にも成功した。一方で、“シカ小型ピロプラズマを活用した牛小型ピロプラズマ病に対する新たな制御法”を考案するには至らなかった。しかし、マダニへの人工感染系が確立できたことから、牛小型ピロプラズマのライフサイクルの詳細な検証が可能となり、今後牛小型ピロプラズマ病に対するワクチンの開発研究が加速するものと期待する。