阴道定植因肯毛孢子菌的分离鉴定

Isolation and identification of Trichosporon inkin colonized in vagina

目的报道1例因肯毛孢子菌（Trichosporon inkin）的阴道定植病例并对该菌进行临床实验研究。方法患者女，34岁，阴道分泌物增多伴异味2个月就诊。对其进行临床实验室检查，并对分离菌株进行纯化、玻片小培养鉴定、温度试验、脲酶试验、生化鉴定、体外药敏试验和分子测序基因鉴定等实验研究。结果患者妇科体检阴道内可见乳白色均质化分泌物附着于阴道壁黏膜，阴道分泌物Nugent评分5～6分。两次阴道分泌物培养均分离出淡黄色有皱褶酵母样菌落。该菌在42℃可生长，玻片玉米琼脂小培养见菌丝顶端附着胞形成及典型八叠球菌样结构，最佳生长培养基为酵母菌形态琼脂培养基，脲酶试验阳性，API 20C AUX和分子测序鉴定为因肯毛孢子菌；该菌对两性霉素B和克霉唑、氟康唑等唑类药物敏感，对氟胞嘧啶和卡泊芬净耐药。结论国内首次发现毛孢子菌在阴道内定植，其准确鉴定有赖于表型特征、生化反应及分子测序的综合分析。

Objective To report a case of vaginal colonization due to Trichosporon inkin. Methods A 34-year-old female presented with increased vaginal discharge accompanied by abnormal odor for 2 months. Clinical laboratory examination was carded out. Cultures of vaginal discharge yielded yeast-like colony. Subsequently, the isolate underwent the following mycological examinations： purification, slide microculture, temperature test, urea enzyme test, biochemistry identification, antifungal susceptibility test, and gene sequencing. Results Gynecological examination revealed white homogeneous secretions attached to mucous membrane of the vagina. Nugent scores of vaginal discharge amounted to 5-6. Two rounds of culture of vaginal discharge resulted in stramineous, reductus and yeast-like colony. The isolate could grow in 42 ℃. Appressorium on the top of hypha and typical sarcinae formed in slide microculture of corn agar, and yeast malt agar was the optimal growth medium for it. Urea enzyme test was positive. API 20C AUX biochemical test and gene sequencing revealed that the isolate was consistent with Trichosporon inkin. The isolate was sensitive to amphotericin B and azoles such as clotrimazole and fluconazole, but resistant to flucytosine and caspofungin. Conclusions It is the first report of vaginal colonization due to T. inkin in China. The accurate identification of T. inkin relies on synthetic analysis of phenotype characteristics, biochemistry test and molecular sequencing.