Elucidation of the fixation factor and elimination measures of MRSA colonized in clinical site for long term

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K10459
• 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: Shujitsu University
• Principal Investigator: Shiota Sumiko 就実大学, 薬学部, 教授 (00368698)
• Co-Investigator(Kenkyū-buntansha): 山田 陽一 就実大学, 薬学部, 講師 (30610927)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: MRSA / 院内感染対策 / バイオフィルム / 薬剤感受性

Outline of Final Research Achievements

Clinical isolates of MRSA were collected in four periods between 2011and 2021. POT types were determined, and characterization was performed. During each period, multiple strains with the same POT type(duplicate POT type strain) that appeared to be nosocomial were isolated.　 Some duplicate POT type strains were continuously isolated from the 1st to 4th periods, but from the 2nd stage onwards, new duplicate POT type strains were introduced and established in the hospital.
The examination of BF components showed that the proportion of extracellular DNA tended to decrease and that of protein increased in strains with high BF formation ability.

Free Research Field

病原微生物

Academic Significance and Societal Importance of the Research Achievements

一病院にて11年間で臨床分離されたMRSAを調べた結果、経年的に院内感染を起こすMRSAのPOT型の種類が増加し、新たなMRSAが院外から流入し、院内に定着していた。継続して分離される株のBF形成能は高い傾向があり、MRSAの定着にBF形成能が大きく関わっていた。BF形成を阻止するために、BFを形成する主たる成分の割合を調べた。また、耐性菌の観点から、化学物質を使わずBF形成を抑制する手法も検討をしている。2016年のAMR対策アクションプランの「2020年までのMRSAの分離率20％」の達成は抗菌薬の使用料の削減だけでは難しく、BF形成に焦点を当てた対策を推進していくことが重要となる。