马尔尼菲青霉菌培养与鉴定

Culturing and Identification of Penicillium marneffei

目的提高马尔尼菲青霉菌(PMA)培养鉴定在基层实验室的诊断水平。方法取患者血液或骨髓液置于BacT/Alert 3D血培养仪系统配套的成人中和抗生素培养瓶,经培养提示阳性,取阳性培养物和淋巴结组织涂片、革兰染色镜检见病原体有细长分枝、分隔菌丝、腊肠形菌体,转种到哥伦比亚血平板、萨布罗琼脂及CHROMagar假丝酵母菌显色培养基,观察25℃和35℃孵育时的菌落形态及镜下菌体特征;测试相关生化反应,观察其结果。结果PMA培养鉴别依据:是双相型真菌,25℃培养为真菌相,35℃培养为酵母相,均能产生葡萄酒红色色素;显微镜下菌体形态:25℃培养有典型的帚状枝,35℃培养可见圆形、卵圆形、两端钝圆略弯曲呈腊肠形有横隔菌体;生化结果:都能同化和发酵葡萄糖产酸,脲素酶阳性,都能被放线菌酮环己酰亚胺抑制,不能同化发酵乳糖。结论PMA适宜的培养基是萨布罗培养基,菌体形态结构适宜的染色是乳酸棉兰染色、革兰染色,适宜基层实验室开展。

OBJECTIVE To improve the diagnosis level of Penicillium marneffei culture identification in the grassroots laboratories. METHODS The patient＇s blood or bone marrow were innoculated to BacT/Alert 3D blood culture system . when positive sample was found, the culture fluid and node tissues were smeared to take, Gram stain. The pathogens suchas small long branch, septate hyphae, sausage-shaped cell, were transferred to Colombia blood plate, sand Paul agar and CHROMagar Candida chromogenic culture medium to observe the 25 ℃ and 35 ℃, to observe the colony morphology and cell characteristics. The relevant biochemical reaction tests, were cutler taken. RESULTS The foundation of identifying P. marneffei culture： it is a dimorphic fungus, cultured for fungal phase at 25℃ ,and for yeast phase at 35℃. Both could produce wine red pigment. Morphology under the microscope：culture had typical broom-shaped sticks at 25℃ ,and round, oval, blunt and slightly curved at both ends,and sausage-shaped thallus that had horizontal septum. Biochemical results：both could assimilate and ferment glucose to produce acid, urea luciferase positive. Both could be inhibited by Actidione, and couldn＇t assimilate fermenting lactose. CONCLUSIONS The appropriate medium for the P. marneffei is Sabourand＇s medium. The appropriate stains of the cell morphology and structure are lactic acid cotton blue staining and Gram staining which are suitable for the grass-root level laboratories.