应用DNA探针鉴定临床分离的念珠菌

Using DNA Probe for appraising Candida isolated from Patients

〔目的〕制备念株菌DNA探针并应用于临床诊断。〔方法〕应用聚合酶链反应扩增白念珠菌标准株的EO3 基因 12 5bp片段 ,同时合成EO3 的 2 5bp特异寡核苷酸 ,扩增产物用半抗原地高辛标记 ,合成寡核苷酸用生物素标记制备成探针 ,检测两种探针显色敏感度 ,并与 2 3株临床分离的白念珠菌、热带念珠菌、近平滑念珠菌及大肠杆菌等细菌进行斑点杂交试验。〔结果〕Dig- 12 5bpDNA探针显色敏感度为 0 .0 1pg,仅与白念珠菌杂交 ;Bio - / 2 5bpDNA探针显色敏感度为2 0pg ,与白念珠菌、热带念珠菌及近平滑念珠菌杂交。〔结论〕Dig- / 2 5bpDNA探针 ,可用于白念珠菌鉴定 ;Bio - 2 5bpDNA探针 ,可用于念珠菌初步鉴定。

Objective〕 Preparation and using of Candida DNA prob e 〔Methods〕 The 125bp DNA from EO3 gene of C.albicans was amplifie d by PCR, then labeled by hepen digoxigenin, and the 25bp specific sequence from EO3 gene was synthesized and labeled with biotin. The sensitivity of these pro bes was detected, and the specificity was detected by dot-blotting hybridization assay with 23 strains C.albicans isolated from patients, C.paropsilosis, C.tropi calis and E,coli and so on. 〔Results〕The Dig-125bp DNA probe, only hybridized with C.albicans, whose sensitivity of color development was 0.01pg, and the Bio-25bp DNA probe, hybridized with C.albicans, C.paropsilosis and C.Tro picalis, whose sensitivity of color development was 20pg. 〔Conclusion〕 The Dig-125bp DNA probe is specific and sensitive to C.albicans and suitabl e for the indentification of clinical C.albicans infection, while the Bio-25bp D NA probe is suitable for the indentification of clinical candida infection