头孢噻肟与他唑巴坦不同配比体外抗菌作用研究

目的研究4种不同配比的头孢噻肟/他唑巴坦(1:1、3:1、5:1、7:1)及头孢噻肟单剂对临床分离致病菌的体外抗菌作用。评价头孢噻肟联合他唑巴坦复方制荆的抗菌活性及不同配比间的差异。方法对临床分离的致病菌(β-内酰胺酶阳性)665株作药物敏感试验。采用琼脂平板二倍稀释法测定最低抑菌浓度(MIC)、试管二倍稀释法测定最低杀菌浓度(MBC)。结果不同配比的头孢噻肟与他唑巴坦均有强大的杀菌作用,明显优于头孢噻肟单剂。对临床分离的大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、宋内氏志贺菌、福氏志贺菌、伤寒沙门菌的MIC90为0.25-16mg/L,比头孢噻肟的活性提高1-32倍。4种不同配比的头孢噻肟/他唑巴坦对(艹卓)革兰阳性菌抗菌活性无明显差异,其中对金黄色葡萄球菌、表皮葡萄球菌和溶血葡萄球菌的MIC50为0.125-16mg/L,活性较头孢噻肟高1-32倍,MIC90为1-32mg/L,活性较头孢噻肟高2-8倍。结论5:1配比的头孢噻肟/他唑巴坦复方制剂对大多数临床分离致病菌具有较强的体外抗菌作用,降低产酶菌耐药性,作用与1:1和3:1配比相当。

Study on antibacterial activities in vitro of different formulas cefotaxime/tazobactam

Objective To study the antibacterial activities in vitro of cefotaxime and different formulas of cefotaxime/tazobactam (1: 1, 3: 1, 5: 1 and 7:1). To evaluate the antibacterial activities of cefotaxime combining with tazobactam, and compare the effects of them. Methods Bacterial susceptibility testing was performed on 665 clinical iso-lates(β-lactmases-producing strains). Minimal inhibitory concentrations (MIC) were determined by use of agar dilution method, and the minimal bactericidal concentrations(MBC) were measured by broth dilution method. Results The antibacterial activities of cefotaxime/tazobactam were better than those of cefotaxime alone. MIC90 of cefotaxime/tazobactam with different formulas against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Shigella sonnei, Shigella flexneri and Salmonella strains was 0.25-16 mg/L, it was 1-32 times higher than that of cefotaxime alone. There were no significant differences among the effects of four different formulas of cefotaxime/tazobactam against gram-positive bacteria. MIC50 of cefotaxime/tazobactam with different formulas against Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus strains was 0.125-16 mg/L, it was as 1-32 times as that of cefotaxime alone. MIC90 was 1-32 mg/L, it was as 2-8 times as that of cefotaxime alone. Conclusion Cefotaxime/tazobactam with 5:1 ratio has higher antibacterial activity against most clinical isolates. It can reduce the drug resistance of β-lact-mases-producing bacteria. The antibacterial activity of cefotaxime/sulbactam (5:1) is equal to that of 1:1 and 3:1 ratio.