2023 Fiscal Year Final Research Report

Microbiological validation for optimization of sustained local antibiotic perfusion therapy for MRSA bone and soft tissue infections

Research Project

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Project/Area Number	21K09241
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 56020:Orthopedics-related
Research Institution	University of Occupational and Environmental Health, Japan
Principal Investigator	Zenke Yukichi 産業医科大学, 医学部, 准教授 (80615930)
Co-Investigator(Kenkyū-buntansha)	安藤恒平産業医科大学, 医学部, 助教 (80899518) 宮原敏産業医科大学, 医学部, 助教 (50878329) 齋藤光正産業医科大学, 医学部, 教授 (00315087) 濱田大志産業医科大学, 医学部, 助教 (20899306) 石川成人産業医科大学, 医学部, 助教 (50848314) 佐藤直人産業医科大学, 医学部, 助教 (20912968) 眞田彩華産業医科大学, 医学部, 助教 (10887045) 酒井昭典産業医科大学, 医学部, 教授 (90248576) 真弓俊彦産業医科大学, 医学部, 教授 (90281071)
Project Period (FY)	2021-04-01 – 2024-03-31
Keywords	バイオフィルム / 耐性菌 / MRSA / 最小バイオフィルム撲滅濃度 / 最小発育阻止濃度 / アミノグリコシド系耐性遺伝子 / 骨軟部感染症 / 持続局所抗菌薬潅流
Outline of Final Research Achievements	<Objective> Antimicrobial treatment of biofilms (BFs) requires a minimum BF eradication concentration (MBEC) that is higher than the minimum inhibitory concentration (MIC). In this study, we measured MBEC of gentamicin (GM) against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and examined its relationship with aminoglycoside resistance genes and MIC. <Methods> A total of 104 MRSA strains isolated at our hospital in 2020 were used. The presence of aac(6')-aph(2"), ant(4'), and aph(3')-III was determined by PCR. <Results> Of 104 clinical isolates of MRSA, 65.4% were resistant to aac(6')-aph(2"), 14.4% to ant(4'), and 0% to aph(3')-III. 68 isolates (65.4%) were resistant to GM (aac(6')-aph(2"), ant(4'), and aph(3')-III). MBEC; 512Mml was found in 67 (65.0%) of the isolates. MBEC 512Mg/ml was consistent with the results for aac(6')-aph(2") (p<2.2x10-16) and GM resistance (MIC; 16Mg/ml) (p<2.2x10-16). MIC;16Mg/ml)(p<2.2x10-16).
Free Research Field	整形外科
Academic Significance and Societal Importance of the Research Achievements	MRSA臨床分離株のBFの撲滅にはMICより高濃度のGMを要することが確認された.骨軟部組織感染症に対して高濃度GMを用いた持続局所抗菌薬灌流療法が検証されているが,今回有効なGM濃度について基礎的データを取得できた.本結果から病巣から分離されたMRSAの耐性遺伝子やMICを調べることで,BFの薬剤感受性を予測できることが示唆された.