下呼吸道分泌物中糠秕马拉色菌的分离与鉴定  

Isolation and identification of Malassezia furfur from lower respiratory tract secretions

作　　者：陈东科[1] 许宏涛[1] 

机构地区：[1]卫生部北京医院检验科,100730

出　　处：《中华检验医学杂志》2012年第8期711-715,共5页Chinese Journal of Laboratory Medicine

基　　金：国家自然科学基金（30872719）

摘　　要：目的对痰涂片镜检可疑为马拉色菌的标本进行马拉色菌的分离培养，并对分离菌株进行系统鉴定。方法收集2010年3月至2011年9月卫生部北京医院经派克墨水染色镜检可疑为马拉色菌的下呼吸道分泌物标本133份，接种于含1％吐温60的科玛嘉琼脂培养基（即改良念珠菌显色培养基），于35cc大气环境中培养。挑取疑似菌落在含0．5％吐温40和0．5％吐温60的沙保弱平板上进行纯培养。采用传统的表型鉴定方法对分离菌株进行鉴定，包括染色镜检观察菌体形态及染色性、沙保弱培养基生长试验、吐温试验、七叶苷分解试验、过氧化氢试验、吐温沉淀试验和蓖麻油试验，可疑菌株采用18srRNA基因序列分析方法对分离菌株进行菌种鉴定。结果镜检可疑的下呼吸道分泌物中马拉色菌分离率为47．4％（63／133），63株分离菌经传统的表型鉴定方法结合18srRNA基因序列分析方法均鉴定为糠秕马拉色菌。标本直接涂片，用派克墨水染色镜下可明显区分马拉色菌和念珠菌。结论糠秕马拉色菌在改良念珠菌显色培养基上的菌落呈粉红色，可明显区别于其他念珠菌菌落，用改良念珠菌显色培养基可提高下呼吸道分泌物中糠秕马拉色菌的分离率。传统的表型鉴定结合基因序列分析可提高马拉色菌鉴定的准确性。Objectives To culture and isolate Malassezia furfur which were suspected in sputum smears, and then to identify the isolates systematically. Methods From March 2010 to September 2011, 133 lower respiratory tract secretion samples were collected in Beijing Hospital of the Ministry of Health which were suspected containing Malassezia fu^ur by Parker ink staining. The samples were inoculated and cultured on CHROMagar mediums containing 1% Tween 60 （ which was modified from Candida chromogenic media） in the atmospheric environment at 35 ~C. The suspected colonies were selected and cultured on both SDA plates containing 0. 5% Tween 40 and SDA plates containing 0. 5% Tween 60. The traditional phenotypic identification methods were used to identify the pure colonies, including staining, growth on Sabouraud agar plates, Tween test, decomposing Escalin, Catalase test, Tween precipitation test and castor oil test. Then the suspected colonies were identified by analyzing the sequences of 18s rRNAs. Results The isolation rate of Malassezia furfur from lower respiratory tract secretions was 47. 4% （63/133） and 63 strains were also identified as Malassezia fu^6zr by traditional phenotypic identification methods combined with the 18s rRNA gene sequence analysis. Malassezia can be significantly distinguished from Candida by direct smear of the specimen with Parker ink staining. Conclusions Malassezia fu^fur was found as pink colonies on modified Candida chromogenic media which were significantly different from other Candida colonies. The isolation rate of lower respiratory tract secretions can be improved by modified Candida chromogenic media. The identification accuracy can be further improved by combining traditional phenotypic identification methods with 18s rRNA sequence analysis.

关 键 词：马拉色霉菌属 痰 表型 RNA 核糖体 18S 序列分析 细菌学技术 

分 类 号：R446.5[医药卫生—诊断学]