20种抗菌药物对金黄色葡萄球菌抗生素后效应的研究

目的 研究20 种抗菌药物对医院感染主要致病菌——金黄色葡萄球菌的抗生素后效应(PAE)。方法 采用光密度法测定PAE, 以实验组与对照组细菌恢复对数生长期时间差计算PAE。结果 在亚MIC 浓度时β-内酰胺类抗生素对金黄色葡萄球菌的PAE 很短, 而大环内酯类、氟喹诺酮类、氨基糖甙类PAE 已很明显, 尤其大环内酯类PAE 可达2 h 左右。随药物浓度增加, PAE 均有增加的趋势。在4 倍MIC 时, 青霉素类、碳青霉烯类PAE 明显延长, 而头孢菌素类PAE 仍相对较短;大环内酯类、氨基糖甙类、氟喹诺酮类药物和磷霉素PAE 显著增加, 并长于β-内酰胺类PAE。结论 抑制蛋白质和DNA 合成的抗菌药物及磷霉素对金黄色葡萄球菌的PAE 较明显, 要长于β-内酰胺类抗生素的PAE, 可能与PAE 产生机制不同有关。

Study on the postantibiotic effects of twenty ant imicrobial agents against S.aureus

Aim The postantibiotic effects (PAE)of 20 ant imicrobial agents against S.aureus collected from patients with nosocomial infections were studied.Methods PAE was determined by the spectrophotometric method and calculated by the difference of time in regrow th phase of bacte ria between tested and controlled groups.Results The PAE of β-lactams against S.aureus was short, but PAEs of macrolides, fluroquinolones and amino glycosides and fosfomycin were marked, especially PAEs of macrolides were up to 2 h in sub-MIC.PAEs of penicillins and carbenpenem were longer than that of cephalospories, PAEs of macrolides, aminoglycosides and fluroquino lones were obviously longer than PAEs of β-lactams in four times of MIC of the drugs. Conclusion PAEs of the antimicrobial agent s, which inhibite synthesis or proteins of DNA, and fosfomycin are significant longer than that of β-lactams(it may be associated with different action mechanisms).