阿萨希毛孢子菌生物膜构建及水杨酸干预策略研究

目的在医院内常用生物材料聚氯乙烯（PVC）表面构建阿萨希毛孢子菌的生物膜，评估该生物膜对几种临床抗真菌药物的耐药性，并观察水杨酸是否对阿萨希毛孢子菌生物膜的形成有干预作用。方法菌株鉴定采用API20CAUX并经PCR鉴定复核；使用PVC于RPM11640-MOPS中培养进行阿萨希毛孢子菌生物膜构建；MIC测定采用法国生物梅里埃公司ATB Fungus-3真菌药敏试剂条以及微量液体稀释法，并观察水杨酸对生物膜构建的影响。结果阿萨希毛孢子菌可以通过几个不连续阶段在聚氯乙烯表面形成生物膜，且已使用PVC块上附着的生物膜细胞比未使用PVC块上黏附的生物膜细胞明显密集；固着相即生物膜细胞的MIC比浮游相成倍提高；24h两性霉素B的MIC〉512μ/ml，且经两性霉素B的药物刺激后，阿萨希毛孢子明显可见芽管延长，菌丝交织；水杨酸作用后阿萨希毛孢子菌的菌丝明显变短，孢子短小。结论介入性器械可以作为阿萨希毛孢子菌生物膜构建的黏附基质，使微生物群体黏附于细胞外多聚材料表面而造成持续播散感染，因此生物膜干预对阿萨希毛孢子菌深部感染的治疗有很重要的意义。

Construction and intervention of Trichosporon asahii Biofilm

Objective To construct and evaluate the in vitro susceptibility to antifungal agents of Trichosporon asahii biofilms on abiotic （polystyrene） surfaces and intervention effect of salicylic. Methods The clinical strains were identified by API20CAUX and PCR. Biofilm was produced in RPMI1640-MOPS incubated with PVC. Antifungal susceptibility testing used the method of trace liquid dilution as well as ATB Fungus-3. Salicylic and PVC was put in cell suspension to observe its intervention. Results T. asahii can produce biofilms through a discrete sequence of events on polystyrene surfaces. There is a remarkable rise in the MICs of sessile T. asahii cells compared to their planktonic counterparts. The MIC of amphotericin B after 24 hours is more than 512 μg/ml. After pharmic stimulation of amphotericin B,the gemmule of T. asahii protracted and hypha was interlaced. With intervention of salicylic,the hypha turned shorted and spore is smaller. Conclusions The prosthetic devices could act possibly as substrates for adhesion and growth of T. asahii biofilms. Therefore,intervention of biofilm could be critical to treat deep-seated T. asahii infection.