头孢卡品体外抗菌作用研究

In vitro activity of cefcapene

目的评价头孢卡品对我国近年临床分离致病菌的体外抗菌作用及影响因素。方法最低抑菌浓度(MIC)测定采用标准琼脂二倍稀释法;最低杀菌浓度(MBC)测定采用标准肉汤二倍稀释法;杀菌曲线绘制采用菌落计数法。结果头孢卡品对甲氧西林敏感葡萄球菌以及绝大部分链球菌具有很强的抗菌作用,MIC范围基本在0.125～4mg/L,其对革兰阳性菌的抗菌作用与头孢妥仑相当,优于头孢泊肟和头孢克肟。头孢卡品对肠杆菌科细菌的MIC50值普遍≤1mg/L。与所测第三代口服头孢菌素相比,其抗菌活性与头孢妥仑、头孢泊肟相近,略逊于头孢克肟。头孢卡品对流感嗜血菌和黏膜炎莫拉菌具有很强的抗菌作用,特别对于流感嗜血菌,MIC值小于0.031mg/L,略优于头孢妥仑,明显优于头孢泊肟和头孢克肟。各影响因素测定结果表明,细菌接种量、培养基pH值及血清含量变化对头孢卡品的MIC值基本无影响,只金黄色葡萄球菌在pH 5.0时,MIC值略有降低。MBC和杀菌曲线测定结果表明,头孢卡品为一时间依赖性杀菌药物。结论头孢卡品对我国近3年临床分离致病菌仍保持较好体外抗菌活性,其抗菌作用与国外文献报道基本一致,值得进一步研究。

Objective To evaluate in vitro activity and effect of cefcapene against clinical isolated pathogenic bacteria in recent years in China. Methods The MICs were determined by the two-fold agar dilution method and the MBCs by the two-fold broth dilution method according to CLSI standards. Time-kills were tested by colony form unit （cfu） count method. Results Cefcapene exhibited excellent antibacterial activity against MSSA and most streptococci. MIC values of cefcapene against those stains were 0.125-4mg/L. It＇s similar to cefditoren and better than cefpodoxime and cefixime. Cefcapene inhibited 50%（MIC50） of Enterobacteriaceae tested at ≤lmg/L. Antibacterial activities of cefcapene against Gram-negative bacilli were comparable to cefditoren and cefpodoxime, but less than cefixime. Against Haemophilus influenzae and Moraxella catarrhalis, cefcapene also showed excellent antibacterial activity, especially against Haemophilus influenzae, MIC values less than 0.03 lmg/L. It＇s better than cefditoren, cefpodoxime and cefixime. There was no significant effect of inoculum size, pH and horse serum on MICs but the activities of cefcapene against Staphylococcus aureus were increased by pH 5.0. MBCs and time-kill curves showed that cefcapene was a time-depended bactericidal agent. Conclusion Cefcapene showed excellent antibacterial activity against clinical isolates in recent years in China, which identical with those reported in literature and deserved further study.