丝孢酵母菌属显色鉴定的研究

Study of color identification for T. asahii and other strains in the same genus

目的比较丝孢酵母菌属与念珠菌在念珠菌显色培养基上不同的显色特点,从而达到对丝孢酵母菌的显色鉴定,为临床诊治丝孢酵母菌病提供依据。方法采用科玛嘉念珠菌显色培养基对18株不同来源的T.asahii临床菌株与该属的6个标准菌株以及38株念珠菌标准菌株与临床菌株进行显色培养,并经BIOMERIEUX VITEK-2-Compact系统鉴定等检测所证实。同时采用扩散法对7种抗真菌药物进行体外敏感性试验。结果丝孢酵母菌在显色培养基上菌落均呈天蓝色,此结果与念珠菌完全不同。所有菌株与VITEK-2-Compact系统鉴定结果一致。所有丝孢酵母菌实验菌株对两性霉素B及沃尔康唑均敏感。所有丝孢酵母菌实验菌株对氟胞密啶及卡泊芬净均耐药。结论科玛嘉念珠菌显色培养基可用于对丝孢酵母菌的鉴定,很适合各级医院的常规检测。两性霉素B及沃尔康唑对丝孢酵母有较强的体外抗菌活性。

Objective To compare the different characteristics of T. ashaii with those of other species belong to the fungi Candida in the Chromogenic/Fluorogenic Culture Media, so as to identify other kinds of T. asahii by color identification and provide the basis for clinical diagnosis and treatment of Trichosporon disease on time. Methods CHROMagar was used for culturing and identifying 18 clinical isolates of T. asahii from different sources, 6 standard strains of T. asahii, and 38 standard strains of Candida. Furthermore, BIOMERIEUX VITEK-2-compact system was used for confirming the results. Meanwhile, the diffusion method was used for susceptibility test of 7 kinds of antifungal drugs in vitro. Results The colonies of all 18 T. asahii clinical isolates and standard strains of T. asahii, T. cutanceum, T.inkin, T. ovoides, T. asteroides appeared sky blue on the CHROMagar, the color was completely different from that of Candida. And the results had been confirmed by BIOMERIEUX VITEK-2-compact system. Susceptibility results showed that 18 clinical isolates of T. asahii, T. ovoides, T. mucoides, T. inkin, T. cutanceum, T. asteroides, and standard strains were all sensitive to VOR and AMPHO. All standard strains and part of clinical isolates were sensitive to FLZ and ITR. And most of the clinical isolates showed moderately sensitive to FLZ and ITR, individually ITR resistance.Most of standard strains and all clinical isolates were moderately sensitive to TEB, and only a few of standard strains were sensitive to TEB. All standard strains and clinical isolates were resistant to FLU and CASP. Conclusion According to the specific characteristics in the CHROMagar of 18 T. asahii clinical isolates and other 4 strains belong to the same genus, we found a simple, reliable, cost-saving method for identifying T. asahii or the same genus of other fungi. And we suggested that this method could be used as routine test in different hospital.