Background

Candida parapsilosis, Candida metapsilosis and Candida orthopsilosis are emerging as relevant causes of candidemia. Moreover, they show differences in their antifungal susceptibility and virulence. The echinocandins are different in terms of in vitro antifungal activity against Candida. Time-kill (TK) curves represent an excellent approach to evaluate the fungicidal activity of antifungal drugs.

Aims

To compare the fungicidal activities of anidulafungin, caspofungin and micafungin against C. parapsilosis species complex by TK curves.

Methods

Antifungal activities of three echinocandins against C. parapsilosis, C. metapsilosis and C. orthopsilosis were studied by TK curves. Drug concentrations assayed were 0.25, 2 and 8 μg/ml. CFU/ml were determined at 0, 2, 4, 6, 24 and 48 h.

Results

Killing activities of echinocandins were species-, isolates- and concentration-dependent. Anidulafungin reached the fungicidad endpoint for 6 out of 7 isolates (86%); it required between 13.34 and 29.67 h to reach this endpoint for the three species studied, but more than 48 h were needed against one isolate of C. orthopsilosis (8 μg/ml). Caspofungin fungicidal endpoint was only achieved with 8 μg/ml against one isolate of C. metapsilosis after 30.12 h (1 out of 7 isolates; 14%). Micafungin fungicidal endpoint was reached in 12.74–28.38 h (8 μg/ml) against one isolate each of C. parapsilosis and C. orthopsilosis, and against both C. metapsilosis isolates (4 out of 7 isolates; 57%).

Conclusions

C. metapsilosis was the most susceptible species to echinocandins, followed by C. orthopsilosis and C. parapsilosis. Anidulafungin was the most active echinocandin against C. parapsilosis complex.

中文翻译：

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阿尼芬净，卡泊芬净和米卡芬净对假丝酵母念珠菌类复合物的杀灭动力学：杀真菌活性的评价。

背景

副念珠菌，念珠菌念珠菌病和正念珠菌病已成为念珠菌血症的相关原因。此外，它们在抗真菌药性和毒力方面显示出差异。棘球菌素在体外对念珠菌的抗真菌活性不同。时间杀灭曲线（TK）代表了评估抗真菌药物杀菌活性的绝佳方法。

目的

通过TK曲线比较阿尼芬净，卡泊芬净和米卡芬净对C. parapsilosis物种复合物的杀真菌活性。

方法

通过TK曲线研究了三种棘球and素对C. parapsilosis，C。metapsilosis和C. orthopsilosis的抗真菌活性。测定的药物浓度为0.25、2和8μg/ ml。在0、2、4、6、24和48小时测定CFU / ml。

结果

棘球and素的杀伤活性是物种，分离物和浓度依赖性的。Anidulafungin在7种分离菌中有6种（86％）达到了杀菌终点。它需要在13.34至29.67小时之间才能达到所研究的三个物种的这一终点，但对一种分离的直立弯曲菌（8μg/ ml）则需要48小时以上。在30.12小时后，仅用8μg/ ml的抗C. metapsilosis分离株就达到了卡泊芬净的杀菌终点（7个分离株中的1个； 14％）。米卡芬净杀真菌端点在12.74-28.38 h达（8微克/毫升）对一种隔离每个的近平滑念珠菌和C. orthopsilosis，以及对既C. metapsilosis分离物（4超过了7株; 57％）。

结论

C. metapsilosis是棘手and病最易感的物种，其次是C. orthopsilosis和C. parapsilosis。Anidulafungin是最有效的棘孢菌素类抗寄生虫念珠菌。