Pfaller M A, Messer S A, Hollis R J
Department of Pathology, University of Iowa College of Medicine, Iowa City 52242.
Diagn Microbiol Infect Dis. 1994 Nov;20(3):127-33. doi: 10.1016/0732-8893(94)90106-6.
Candida lusitaniae is an important nosocomial pathogen that may express resistance to one or more antifungal agents including amphotericin B. We investigated the genotypic diversity and antifungal susceptibility among 47 clinical isolates from 33 patients hospitalized in 12 different medical centers. Strain delineation was performed by restriction endonuclease analysis of genomic DNA (REAG) with the restriction enzyme Sfi I followed by pulsed-field gel electrophoresis and by electrophoretic karyotyping (EK). Antifungal susceptibility of the isolates to amphotericin B, 5-fluorocytosine (5FC), fluconazole, and itraconazole was determined using National Committee for Clinical Laboratory Standards standard methods. Minimum inhibitory concentration (MIC)90 values ranged from 0.5 micrograms/ml for itraconazole to 512 micrograms/ml for 5FC. In general, isolates from a given patient or epidemiologically related isolates from a nosocomial cluster were identical by molecular typing methods. Epidemiologically unrelated isolates were all distinctly different by both EK and REAG typing methods. Although elevated amphotericin B MICs ( > or = 2 micrograms/ml) were observed in only three isolates, extended incubation (72 h) revealed amphotericin B MICs of 2-16 micrograms/ml in a subset of isolates suggesting potential amphotericin B resistance. These data document the genetic diversity, nosocomial transmission, and antifungal susceptibility of clinical isolates of C. lusitaniae.
葡萄牙念珠菌是一种重要的医院病原体，可能对包括两性霉素B在内的一种或多种抗真菌药物产生耐药性。我们调查了来自12个不同医疗中心住院的33名患者的47株临床分离株的基因型多样性和抗真菌药敏性。通过用限制性内切酶Sfi I对基因组DNA进行限制性内切酶分析（REAG），随后进行脉冲场凝胶电泳和电泳核型分析（EK）来进行菌株鉴定。使用美国国家临床实验室标准委员会的标准方法测定分离株对两性霉素B、5-氟胞嘧啶（5FC）、氟康唑和伊曲康唑的抗真菌药敏性。最低抑菌浓度（MIC）90值范围从伊曲康唑的0.5微克/毫升到5FC的512微克/毫升。一般来说，来自给定患者的分离株或医院感染群中流行病学相关的分离株通过分子分型方法是相同的。通过EK和REAG分型方法，流行病学无关的分离株都明显不同。虽然仅在三株分离株中观察到两性霉素B的MIC升高（≥2微克/毫升），但延长孵育时间（72小时）显示，一部分分离株中两性霉素B的MIC为2-16微克/毫升，提示可能存在两性霉素B耐药性。这些数据证明了葡萄牙念珠菌临床分离株的遗传多样性、医院感染传播和抗真菌药敏性。
