Brumfitt W, Maple P A, Hamilton-Miller J M
Department of Medical Microbiology, Royal Free Hospital, Hampstead, London, UK.
Drugs Exp Clin Res. 1990;16(8):377-83.
The authors have investigated the activity of ramoplanin against 162 isolates of MRSA from some twenty-six countries around the world. MICs were determined by the plate dilution method in isosensitest agar with an inoculum of 10(6) cfu. MBCs were measured by replication, using velvet pads, from MIC plates after 24 h incubation at 37 degrees C. Time-kill curves were determined from viable counts of cultures in Isosensitest broth (inoculum ca. 5.0 x 10(6) cfu/ml) taken at intervals during shaking culture at 37 degrees C for up to 24 h. Ciprofloxacin, mupirocin, rifampicin, teicoplanin and vancomycin were used as comparison compounds. The following MIC90 (MBC90) values (mg/l) were obtained against a selection of 60 strains: ciprofloxacin 0.8 (1.8), mupirocin 0.27 (19.0), ramoplanin 0.5 (1.0), rifampicin 0.007 (0.01), teicoplanin 1.2 (greater than 32) and vancomycin 2.2 (greater than 32.0). In time-kill experiments, ramoplanin at 20 mg/l and ciprofloxacin at 3.0 mg/l produced 99.9% killing in less than 4h. Mupirocin at 4.0 mg/l was only slowly bactericidal. No resistance was found to mupirocin, ramoplanin, teicoplanin or vancomycin in the 162 isolates tested, whereas ca. 20% resistance was found to ciprofloxacin and rifampicin. The absence of resistance, the high intrinsic activity and the rapid bactericidal effect of ramoplanin against this diverse group of MRSA are very encouraging, and suggest that clinical trials are indicated.
作者研究了瑞莫拉宁对来自世界约26个国家的162株耐甲氧西林金黄色葡萄球菌（MRSA）的活性。采用平板稀释法在等敏感琼脂中测定最低抑菌浓度（MIC），接种量为10(6) cfu。在37℃孵育24小时后，使用天鹅绒垫从MIC平板上通过复制法测量最低杀菌浓度（MBC）。通过在37℃振荡培养长达24小时期间每隔一段时间对等敏感肉汤中的培养物进行活菌计数来确定时间-杀菌曲线。环丙沙星、莫匹罗星、利福平、替考拉宁和万古霉素用作对照化合物。针对60株菌株获得了以下MIC90（MBC90）值（mg/l）：环丙沙星0.8（1.8）、莫匹罗星0.27（19.0）、瑞莫拉宁0.5（1.0）、利福平0.007（0.01）、替考拉宁1.2（大于32）和万古霉素2.2（大于32.0）。在时间-杀菌实验中，20mg/l的瑞莫拉宁和3.0mg/l的环丙沙星在不到4小时内产生了99.9%的杀菌效果。4.0mg/l的莫匹罗星杀菌作用缓慢。在所测试的162株菌株中，未发现对莫匹罗星、瑞莫拉宁、替考拉宁或万古霉素的耐药性，而对环丙沙星和利福平的耐药率约为20%。瑞莫拉宁对这一多样的MRSA群体无耐药性、具有高内在活性和快速杀菌作用，这非常令人鼓舞，并表明有必要进行临床试验。
