Nguyen M H, Clancy C J, Yu V L, Yu Y C, Morris A J, Snydman D R, Sutton D A, Rinaldi M G
University of Florida College of Medicine, VA Medical Center, Gainesville 32610, USA.
J Infect Dis. 1998 Feb;177(2):425-30. doi: 10.1086/514193.
Outcome for 105 patients with candidemia treated with amphotericin B was correlated with amphotericin B in vitro susceptibility results. Thirty-three patients had microbiologic failure, which was defined as persistence of Candida in the bloodstream despite > or = 3 days of amphotericin B. Amphotericin B minimum inhibitory concentrations (MICs) were determined by the National Committee for Clinical Laboratory Standards methodology. After determination of MICs, the minimal lethal concentrations (MLCs) were determined. The isolates tested yielded a narrow range of amphotericin B MICs (0.06-2 microg/mL); only 5% (5/105) exhibited MICs > or = 1 microg/mL. The MLC range, on the other hand, was significantly broader (0.125 to > 16 microg/mL); 24% (25/105) exhibited MLCs > or = 1 microg/mL. The strongest predictor for microbiologic failure was 48-h MLC (P < .001), followed by 24-h MLC (P = .03) and 48-h MIC (P = .11). A resistant break point for amphotericin B of > 1 microg/mL for MLC and > or = 1 microg/mL for MIC could be inferred from this study.
105例接受两性霉素B治疗的念珠菌血症患者的治疗结果与两性霉素B的体外药敏结果相关。33例患者出现微生物学治疗失败，定义为尽管接受了≥3天的两性霉素B治疗，但念珠菌仍持续存在于血流中。两性霉素B的最低抑菌浓度（MIC）采用美国国家临床实验室标准委员会的方法测定。在测定MIC后，再测定最低致死浓度（MLC）。所测试的分离株产生的两性霉素B MIC范围较窄（0.06 - 2μg/mL）；只有5%（5/105）的分离株MIC≥1μg/mL。另一方面，MLC范围明显更宽（0.125至>16μg/mL）；24%（25/105）的分离株MLC≥1μg/mL。微生物学治疗失败的最强预测指标是48小时MLC（P<0.001），其次是24小时MLC（P = 0.03）和48小时MIC（P = 0.11）。从本研究中可以推断出两性霉素B的耐药界值为MLC>1μg/mL和MIC≥1μg/mL。
