基于ITS基因序列鉴定阿萨希毛孢子菌及体外药敏分析

目的探讨使用ITS基因序列鉴定临床分离的阿萨希毛孢子菌及对常见抗真菌药物的体外敏感性,为临床治疗提供依据。方法对8株临床分离的阿萨希毛孢子菌通过形态学及核糖体r DNA ITS序列分析鉴定到种;使用法国梅里埃ATB FUNGUS 3真菌药敏试剂条测定氟康唑、伏立康唑、伊曲康唑、两性霉素B及5氟胞嘧啶对8株阿萨希毛孢子菌的最低抑菌浓度。结果阿萨希毛孢子菌在沙氏培养基上形成表面有干燥粉状物,奶油色酵母样菌落;转种科玛嘉念珠菌显色培养基背面明显呈蓝色,正面呈浅蓝色;转种米粉培养基后,镜下可见大量的关节孢子。核糖体r DNAITS序列分析结合形态学特点可以将阿萨希毛孢子菌鉴定到种,药敏结果显示8例患者中,有3例对5-氟胞嘧啶耐药,其余均中介;有3例对两性霉素B敏感,其余均耐药;有3例对伊曲康唑敏感,其余均中介;8例均对氟康唑和伏立康唑敏感。结论 ITS序列分析准确快速,可以辅助临床区分难鉴定毛孢子菌。阿萨希毛孢子菌药敏谱不同于临床常见其他酵母菌,5-氟胞嘧啶、两性霉素B和伊曲康唑对其活性差,氟康唑和伏立康唑具有良好的体外抗菌活性。

Analysis of in vitro drug susceptibility of T.asahiiisolates identified by ITS gene sequences

Objective To observe in vitro drug susceptibility of T.nsahff identified by ITS gene sequences so as to provide the basis for clinical treatment. Method The 8 T.asahffstrains isolated in clinic were identified by ITS gene sequences; the MIC of fluconazole, voriconazole, itraconazole, amphotericin B and 5-fluorocytosine were detected by USE ATB FUNGUS 3. Results The colony morphology of T.nsahff on SDA was like a dry powder, cream yeast-like colonies; the back side was blue and the front side was light blue on CHROMagar candida medium; lots of arthrospore were seen on the Corn Meat Medium. 8 T.asahii strains isolated in clinic Were identified by ：iTS gene sequences. 3 strains were resistant to 5- fluorocytosine, 3 strains were sensitive to amphotericin B0 and the rest were resistant; 3 strains were sensitive to itraconazole, all strains were sensitive to fluconazole and voriconazole. Conclusion ITS sequence analysis can identify trichosporen quickly and accurately. T.asahfi antimicrobial resistance of T.asahff is different from other common clinical yeast, the activity of 5-flucytosine, amphotericin B and itrac0nazole were iower, fluconazole and voriconazole were high in vitro Antibacterial activity.