BACKGROUND Daptomycin is an important drug used in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection. A high dose of daptomycin is indicated for an MRSA infection with a minimum inhibitory concentration (MIC) of 1 mg/L for daptomycin. Combination therapies with daptomycin and other antimicrobial agents, including fosfomycin, display in vitro synergism potentially. This study was conducted to investigate the in vitro synergistic effect of daptomycin-based combination therapy against MRSA strains with high daptomycin MIC. METHOD The synergistic effects of daptomycin in combination with fosfomycin, gentamicin, linezolid, oxacillin, or rifampicin against MRSA with an MIC of 1 mg/L for daptomycin were measured using the microbroth checkerboard assay in vitro. RESULT A total of 100 MRSA isolates was tested. The synergistic interactions of the drugs were evaluated using the fractional inhibitory concentration index. The MIC values revealed that all isolates (100%) were found to be susceptible to linezolid, 85% to fosfomycin, 8% to gentamicin, 69% to rifampicin, and no isolate was susceptible to oxacillin. The in vitro synergism rates of daptomycin in combination with fosfomycin, oxacillin, gentamicin, linezolid, and rifampicin were 37, 11, 5, 3, and 1%, respectively. CONCLUSION The combination of daptomycin plus fosfomycin may be an effective therapeutic option for MRSA infection.

中文翻译：

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达托霉素与所选抗菌药物联合使用的研究：MIC值为1 mg / L对MRSA菌株的体外协同作用。

背景技术达托霉素是用于治疗耐甲氧西林的金黄色葡萄球菌（MRSA）感染的重要药物。高剂量达托霉素适用于MRSA感染，达托霉素的最低抑菌浓度（MIC）为1 mg / L。与达托霉素和其他抗菌药物（包括磷霉素）的联合治疗可能会显示出体外协同作用。进行这项研究以研究基于达托霉素的联合治疗对具有高达托霉素MIC的MRSA菌株的体外协同作用。方法采用微孔棋盘法测定达托霉素与磷霉素，庆大霉素，利奈唑胺，奥沙西林或利福平联合对MRSA的协同作用，MIC为1 mg / L。结果总共测试了100个MRSA分离株。使用分数抑制浓度指数评估药物的协同相互作用。MIC值表明，所有分离株（100％）对利奈唑胺敏感，对磷霉素敏感，对庆大霉素为8％，对利福平为69％，对奥沙西林不敏感。达托霉素与磷霉素，奥沙西林，庆大霉素，利奈唑胺和利福平的体外协同作用率分别为37％，11％，5％，3％和1％。结论达托霉素联合磷霉素可能是治疗MRSA的有效方法。而且没有分离株对奥沙西林敏感。达托霉素与磷霉素，奥沙西林，庆大霉素，利奈唑胺和利福平的体外协同作用率分别为37％，11％，5％，3％和1％。结论达托霉素联合磷霉素可能是治疗MRSA的有效方法。而且没有分离株对奥沙西林敏感。达托霉素与磷霉素，奥沙西林，庆大霉素，利奈唑胺和利福平的体外协同作用率分别为37％，11％，5％，3％和1％。结论达托霉素联合磷霉素可能是治疗MRSA的有效方法。