How the staphylococcal species acquire resistance, and how they exchange genetic information?

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K10055
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 58020:Hygiene and public health-related: including laboratory approach
• Research Institution: Sapporo Medical University
• Principal Investigator: Urushibara Noriko 札幌医科大学, 医学部, 准教授 (80396308)
• Co-Investigator(Kenkyū-buntansha): アウン メイジソウ 札幌医科大学, 医学部, 講師 (10749584) ; 小林 宣道 札幌医科大学, 医学部, 教授 (80186759)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ブドウ球菌 / MRSA / 可動性遺伝因子 / 水平伝播 / SCCmec / livestocks

Outline of Final Research Achievements

MRSA infection is an ongoing challenge. Staphylococcal species exchange genetic information through staphylococcal cassette chromosome (SCC). It encompasses not only drug resistance genes but also diverse genes useful for better adaptation to the unfriendly environment. The present study has aimed to reveal how the mobile genetic elements emerged, evolved, and spread among staphylococcal species. SCC elements obtained from MRSA clinical isolates were determined for their nucleotide sequences, and compared with staphylococcal genomes deposited in a public databank. Following two novel elements were identified: a novel subtype of type IX SCC carrying mec gene (SCCmec) in Myanmar MRSA, an SCC in MRSA from including speG and a staphylococcal surface protein coding gene (sasG) in Japanese MRSA. Obtained data suggests that they have originated in coagulase-negative staphylococcal species.

Free Research Field

衛生学

Academic Significance and Societal Importance of the Research Achievements

薬剤耐性菌の蔓延は世界的な問題である。一方，新規の抗菌薬等の開発は停滞しており，耐性菌を含めた感染起因菌の動向調査に基づいた感染制御が必要不可欠である。特にわが国では MRSA の検出率がいまだ高く，克服すべき課題である。本研究ではブドウ球菌に特徴的な可動性遺伝因子に着目し，新規の遺伝子構造を見出し，宿主の表現型への寄与を検討した。得られた結果は，遺伝子構造多型に基づく感染起因菌の型別法に新たな情報を付加し，医療施設および市中での耐性菌の監視及び動向予測に資する結果と言える。