Development of a novel strategy toward bovine mastitis using an insect antimicrobial peptide

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K22357
• 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: Tohoku University
• Principal Investigator: Yoneyama Hiroshi 東北大学, 農学研究科, 教授 (10220774)
• Co-Investigator(Kenkyū-buntansha): 安藤 太助 東北大学, 農学研究科, 助教 (40250732)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: 抗菌ペプチド / 乳房炎 / 黄色ブドウ球菌

Outline of Final Research Achievements

Staphylococcus aureus is the most important etiologic agent of bovine mastitis. To develop a novel strategy to control mastitis, we focused on an antimicrobial peptide, persulcatusin derived from Ixodes persulcatus, a vector for human tick-borne diseases in Japan, and constructed its high microbial expression system. For this, we employed calmodulin as a tag to construct a chimeric protein in which TEV protease recognition sequence was inserted between calmodulin and persulcatusin. The chimeric protein obtained by an affinity chromatography purification was treated with TEV protease to release free perusulcatusin. Subsequently, its antimicrobial activity was determined by a bioassay using S. aureus 209P as the test strain. Consequently, we found that TEV-treated chimeric protein, in which free persulcatusin was present, showed stronger antimicrobial activity than the chimeric persulcatusin.

Free Research Field

動物微生物学

Academic Significance and Societal Importance of the Research Achievements

畜産生産現場で多量に使用されている抗生物質は、病原細菌に対する選択圧として作用するため、薬剤耐性菌出現の温床となることが危惧されている。本研究課題は抗生物質に頼らない家畜生産システムの構築を目標とし、薬剤耐性菌出現頻度が既存の抗生物質よりも低い昆虫由来抗菌ペプチドpersulcatusinに注目し、その微生物を宿主とした高発現系の構築と実用化に向けた基礎微生物学的解析を行っている。本研究においてpersulcatusinの安価な生産システムの構築とその生物学的特性の詳細が解明された暁には、現在公衆衛生上の大きな問題となっている薬剤耐性菌問題に対処するための一助になると考えられる。