达托霉素对2679株革兰阳性球菌体外抗菌活性的研究

A study of in vitro activity of daptomycin against 2679 Gram-positive cocci

目的研究达托霉素等抗菌药物对2679株革兰阳球菌的体外抗菌活性。方法收集2010年1月—2011年12月9个城市17家教学医院临床分离的2679株非重复革兰阳性球菌。采用微量肉汤稀释法测定的达托霉素最低抑菌浓度（MIC），用琼脂稀释法测定其他抗菌药物的MIC值，用WHONET5．6软件进行药敏数据统计分析。结果耐甲氧西林金黄色葡萄球菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRSCoN）检出率分别为45．8％和84．2％，MRSA对复方磺胺甲嗯唑和氯霉素的敏感率分别为93．1％和85．5％，对红霉素、四环素、克林霉素和利福平的敏感率分别为13．8％、26．6％、63．2％、50．0％，对达托霉素、万古霉素和利奈唑胺的敏感率均为100．O％，MRSCoN对达托霉素、万古霉素和利奈唑胺的敏感率均为100．0％，达托霉素对于MRSA和MRSCoN的MIC50和MIC50均为0．5mg／L。513株肠球菌对于高水平庆大霉素耐药率为56．9％，氯霉素和四环素的敏感率分别为76．O％和44．1％，对替加环素和达托霉素敏感率均达100．0％，达托霉素对于其中17株耐万古霉素肠球菌（VRE）的MIC50和MIC90均为2mg／L。肺炎链球菌和β-溶血链球菌对于达托霉素的敏感率均为100．0％，按口服青霉素折点判读，青霉素不敏感的肺炎链球菌（PNSSP）的比例为63．1％。达托霉素对于PNSSP的MIC50和MIC90分别是0．125mg／L和0．25mg／L。达托霉素对于β-溶血链球菌MIC50和MIC90分别是0．008mg／L和0．032mg／L。结论达托霉素对临床常见革兰阳性球菌具有较好的抗菌活性，包括多重耐药菌，是治疗革兰阳性菌特别是耐药菌感染的很好选择。

Objective To evaluate the in vitro activity of daptomycin against 2679 Gram-positive cocci. Methods A total of 2679 non-duplicate Gram-positive cocci isolates were collected from 17 teaching hospitals during January, 2010 and December, 2011. The minimal inhibitory concentrations （MICs） of daptomycin and other anti-microbial agents against 4 Gram-positive cocci were determined by micro-broth dilution method and agar dilution respectively. The data of drug susceptibility were analyzed by WHONETS. 6 software. Results Methicillin-resistant Staphylococcus aureus （MRSA） and methicillinresistant coagulase-negative Staphylococci （MRSCoN） detection rates were 45.8% and 84.2%, respectively. The susceptibility rates of sulfamethoxazole, chloramphenicol, erythromyein, tetracycline, clindamycin and rifampicin against MRSA were 93.1% , 85.5% , 13.8% , 26. 6% , 63.2% and 50.0% , respectively. The susceptibility rates of daptomycin, vaneomycin and linezolid against MRSA and MRSCoN were all 100. 0%. The daptomyein MIC50 and MIC90 of MRSCoN and MRSA were 0. 5 mg/L. The high level gentamicin resistance rate of 513 Enterococci isolates was 56. 9%. The susceptibility rates of chloramphenicol and tetracycline were 76.0% and 44. 1%, respectively. The susceptibility rates of tigecycline and daptomycin reached 100. 0%. The MIC50 and MIC90 of daptomycin against 17 vancomycin-resistant Enterococci （VRE） were both 2 mg/L. The susceptibility rates of daptomycin against Streptococcus pneumoniae and β-hemolytic Streptococcus were 100. 0%. The prevalence of penicillin-nonsusceptible Streptococcus pneumoniae （PNSSP） was 63. 1%. The MIC50 and MIC90 of daptomycin against PNSSP were 0. 125 mg/L and 0. 25 mg/L, respectively according to the breakpoint of oral penicillin. The MIC50 and MIC90 daptomycin against S-hemolytic Streptococci were 0. 008 mg/L and 0. 032 mg/L. Conclusions Daptomycin have excellent in vitro activity against common Gram-positive cocci, including multi-drug resistant bacteria. It may be a good choice ior clinicians to treat drug-resistant Gram-positive cocci.