中文摘要：

目的评价米诺环素与夫西地酸对临床分离到的98株耐甲氧西林金黄色葡萄球菌（MRSA）的联合体外抗菌活性,及两药联用的抗MRSA效应。方法用棋盘法设计,用微量肉汤稀释法,测定不同浓度组合的抗菌药物对98株临床分离MRSA的最低抑菌浓度,并计算部分抑菌浓度指数（FICI）,判定联用效应。结果米诺环素与夫西地酸联用后,2种抗菌药物对临床分离得到的98株MR-SA的MIC50显著降低。FICI分布：FICI≤0.5（协同作用）占57.14%;0.5〈FICI≤4（无关作用）占42.86%;FICI〉4（拮抗作用）为0。结论米诺环素与夫西地酸体外联用对98株临床分离的MRSA体外抗菌效应以协同作用为主;无关作用较少;无拮抗作用。

英文摘要：

Objective To evaluate the in vitro antibiotic effects of minocycline combined with fusidic acid against 98 strains of methicillin-resistant Staphylococcus aureus（MRSA）.Methods The protocol was designed by checkerboard method and the MICs of minocycline alone and combined with fusidic acid against the 98 strains of methicillin-resistant Staphylococcus aureus were determined by broth dilution method.The fractional inhibitory concentration index（FICI） was calculated according to MIC results.The interaction was measured by the FICI.Antagonism was defined as FICI 4,indifference as 0.5 FICI ≤ 4,and synergism as FICI≤0.5.Results The MIC50 of minocycline combined with fusidic acid against 98 strains of methicillin-resistant Staphylococcus aureus was descended significantly.The percentage of the FICI less than 0.5,from 0.5 to 4,more than 4 were 57.14%,42.86%,0 respectively.Conclusion The results suggest that combination of minocycline with fusidic acid has moderate synergistic activity against methicillin-resistant Staphylococcus aureus in vitro,which may be a potential therapeutic alternative for infections caused by MRSA.