Peric Mihaela, Lin Gengrong, Clark Catherine L, Jacobs Michael R, Appelbaum Peter C
Departments of Pathology, Hershey Medical Center, 500 University Drive, Hershey, PA 17033, USA.
J Antimicrob Chemother. 2002 Jul;50(1):95-100. doi: 10.1093/jac/dkf080.
The in vitro activity of AZD2563, a new oxazolidinone, was compared with that of linezolid, vancomycin, quinupristin/dalfopristin, amoxicillin, levofloxacin, penicillin, erythromycin, azithromycin and clindamycin against a range of pneumococci by microdilution and time-kill studies. Against 300 pneumococci (99 penicillin susceptible, 86 penicillin intermediate, 115 penicillin resistant, 185 erythromycin resistant, 35 quinolone resistant), both oxazolidinones remained active against isolates less susceptible to other agents, with MICs ranging between 0.125 and 2 mg/L; AZD2563 MICs were generally one dilution lower than those of linezolid. Both quinupristin/dalfopristin and vancomycin were active against all groups (MIC ranges 0.125-2 and 0.125-0.25 mg/L, respectively). Apart from 35 isolates with levofloxacin MICs > or= 8 mg/L, levofloxacin MICs were < or =0.25-4 mg/L. MICs of amoxicillin and erythromycin rose with penicillin G MICs; most macrolide-resistant isolates were either penicillin-intermediate or -resistant. Against 16 organisms with differing beta-lactam, macrolide and quinolone MICs, time-kill studies showed that AZD2563 was bactericidal (99.9% killing) at 4 x MIC against nine strains at 24 h, with 90% killing of all 16 strains at 2 x MIC after 12 h. Similar results were obtained with linezolid. Both oxazolidinones were bacteriostatic at the MIC against all 16 strains. Amoxicillin, levofloxacin and vancomycin, at 2 x MIC, were bactericidal against 15 of the 16 strains after 24 h. Quinupristin/dalfopristin yielded the most rapid killing, with bactericidal activity against 13 of 16 strains at the MIC after 3 h and against 15 strains at 2 x MIC after 24 h. Erythromycin was bactericidal against all 10 strains with MICs < or= 8 mg/L at 4 x MIC after 24 h.
通过微量稀释法和时间杀菌研究，比较了新型恶唑烷酮类药物AZD2563与利奈唑胺、万古霉素、奎奴普丁/达福普汀、阿莫西林、左氧氟沙星、青霉素、红霉素、阿奇霉素和克林霉素对一系列肺炎球菌的体外活性。针对300株肺炎球菌（99株对青霉素敏感，86株对青霉素中介，115株对青霉素耐药，185株对红霉素耐药，35株对喹诺酮耐药），两种恶唑烷酮类药物对其他药物敏感性较低的菌株仍有活性，MIC范围在0.125至2mg/L之间；AZD2563的MIC通常比利奈唑胺低一个稀释度。奎奴普丁/达福普汀和万古霉素对所有组均有活性（MIC范围分别为0.125 - 2和0.125 - 0.25mg/L）。除35株左氧氟沙星MIC≥8mg/L的菌株外，左氧氟沙星的MIC≤0.25 - 4mg/L。阿莫西林和红霉素的MIC随青霉素G的MIC升高；大多数对大环内酯类耐药的菌株对青霉素中介或耐药。针对16株具有不同β-内酰胺、大环内酯和喹诺酮MIC的菌株，时间杀菌研究表明，AZD2563在4倍MIC浓度下对9株菌株在24小时时具有杀菌作用（杀菌率99.9%），在2倍MIC浓度下12小时后对所有16株菌株的杀菌率达90%。利奈唑胺也得到了类似结果。两种恶唑烷酮类药物在MIC浓度下对所有16株菌株均为抑菌作用。阿莫西林、左氧氟沙星和万古霉素在2倍MIC浓度下，24小时后对16株菌株中的15株具有杀菌作用。奎奴普丁/达福普汀杀菌速度最快，在MIC浓度下3小时后对16株菌株中的13株具有杀菌作用，在2倍MIC浓度下24小时后对15株菌株具有杀菌作用。红霉素在24小时后在4倍MIC浓度下对所有MIC≤8mg/L的10株菌株具有杀菌作用。
