Hayashi I, Sakurai M, Ichiki M, Sekine I, Nakayama K, Shiotani J, Yoshida T, Niida M, Ogawa M, Koumoto A
Department of Internal Medicine, Cancer Institute Hospital.
Jpn J Antibiot. 1994 Jan;47(1):29-39.
Pseudomonas aeruginosa has been a major bacterial partner when MRSA (Methicillin-resistant Staphylococcus aureus) is isolated clinically. Hence, we studied the in vitro combined effect of fosfomycin (FOM) plus sulbactam/cefoperazone (SBT/CPZ) against mixed infections of MRSA and P. aeruginosa. The combined effect of FOM plus SBT/CPZ was observed through an FIC index using the checkerboard method, log reduction of colony counts on the time killing curve, and morphological changes observed using scanning electron micrography. Under serum concentration at 3 hours after administration in consider of pharmacokinetics, the combination effect was also evaluated. Furthermore, we evaluated a time-lag combination therapy in which FOM is administered 60 minutes before SBT/CPZ administration for mixed infections. Synergistic effects of FOM plus SBT/CPZ were clearly observed against mixed infections of MRSA and P. aeruginosa. Log reduction of colony counts on the time killing curve seemed to be an appropriate indicator in the evaluation of synergistic effects.
在临床上分离出耐甲氧西林金黄色葡萄球菌（MRSA）时，铜绿假单胞菌一直是主要的细菌伴生菌。因此，我们研究了磷霉素（FOM）联合舒巴坦/头孢哌酮（SBT/CPZ）对MRSA和铜绿假单胞菌混合感染的体外联合效应。通过棋盘法使用FIC指数、时间杀菌曲线上菌落计数的对数减少以及扫描电子显微镜观察到的形态变化来观察FOM联合SBT/CPZ的联合效应。考虑到药代动力学，在给药后3小时的血清浓度下，也评估了联合效应。此外，我们评估了一种时间延迟联合疗法，即在SBT/CPZ给药前60分钟给予FOM用于混合感染。FOM联合SBT/CPZ对MRSA和铜绿假单胞菌的混合感染具有明显的协同效应。时间杀菌曲线上菌落计数的对数减少似乎是评估协同效应的合适指标。
