In vitro Activity and Post-Antibiotic Effect of Quinupristin/Dalfopristin (Synercid)
In vitro Activity and Post-Antibiotic Effect of Quinupristin/Dalfopristin (Synercid)
复制标题
奎努普丁/达福普丁 (Synercid) 的体外活性和抗生素后效应
作者：
T. Ling;K. Fung;A. Cheng
以526株革兰氏阳性菌为对照，检测奎努普汀/达福普汀、氨苄西林、红霉素、克拉霉素、万古霉素、替考拉宁、环丙沙星、四环素的体外抗菌活性。奎努普汀/达福普汀对包括甲氧西林耐药株在内的金黄色葡萄球菌的最低抑菌浓度(MIC90)较低(MIC90=0.5 mg/L)，与万古霉素和替考拉宁相当。该化合物对肺炎链球菌(青霉素敏感株和青霉素耐药株)的MIC90为2 mg/L，对其他链球菌的MIC90为4 mg/L，但对肠球菌的活性较差(MIC90=32 mg/L)。奎努普汀/达福普斯汀对革兰氏阳性厌氧菌，包括梭状芽孢杆菌、消化球菌等具有较高的抗菌活性。≤为2 mg/L，对9株革兰氏阳性菌(葡萄球菌、肠球菌和肺炎球菌)的抗生素后效应和杀菌动力学进行了研究。将指数生长期(对数生长期)的细胞暴露于2×MIC的奎努普汀/达夫普利斯汀。用活细胞计数法评价生长动力学。该药物在作用2 h内对肺炎球菌和葡萄球菌均有杀灭作用，对葡萄球菌作用8 h。对肠球菌的杀灭活性较弱；孵育24小时后细菌数几乎没有减少。对肺炎球菌、葡萄球菌和肠球菌产生的PAE分别为2.13~3.28h、0.92~3.02h和1.89~7.07h。这项研究表明奎努普汀/达福普利斯汀是一种很有前途的抗革兰氏阳性菌药物。延长的PAEs还表明，该药物可以以更广泛的剂量间隔间歇使用，以对抗革兰氏阳性细菌。
The in vitro activities of quinupristin/dalfopristin (Synercid), ampicillin, erythromycin, clarithromycin, vancomycin, teicoplanin, ciprofloxacin and tetracycline were examined and compared against 526 gram-positive bacteria. The minimal inhibitory concentrations (MICs) for quinupristin/dalfopristin against Staphylococcus aureus, including methicillin-resistant strains, were low (MIC90 = 0.5 mg/l), and were comparable with those of vancomycin and teicoplanin. This compound was superior to the macrolides and highly active against Streptococcus pneumoniae (both penicillin-sensitive and penicillin-resistant strains), with MIC90 = 2 mg/l. It was also active against other streptococci, with MIC90 = 4 mg/l. However, this agent is less active against enterococci (MIC90 = 32 mg/l). Quinupristin/dalfopristin showed high activity against gram-positive anaerobes, including Clostridium spp., Peptococcus spp. and Peptostreptococcus spp., with MIC90 ≤2 mg/l. Quinupristin/dalfopristin was also investigated for its post-antibiotic effect (PAE) and bactericidal kinetics against nine strains of gram-positive organisms, including staphylococci, enterococci and pneumococci. Exponentially growing (log phase) cultures were exposed to quinupristin/dalfopristin at 2 × MIC. Growth kinetics was evaluated using viable counting. The drug was uniformly bactericidal against pneumococci and staphylococci within 2 and 8 h of exposure, respectively. The killing activity against enterococci was weak; there was little or no reduction in bacterial count over 24 h of incubation. PAEs ranging from 2.13 to 3.28 h, 0.92 to 3.02 h and 1.89 to 7.07 h were produced on the tested pneumococci, staphylococci and enterococci, respectively. This study showed that quinupristin/dalfopristin is a promising agent active against gram-positive bacteria. The prolonged PAEs also suggest that the drug could be used intermittently at more widely spaced dosing intervals against gram-positive organisms.