应用ITS_1-ITS_2区域鉴定口腔念珠菌

Using ITS_1-ITS_2 region to distinguish oral Candida species

目的 :建立快速、准确鉴别念珠菌的方法。方法 :通过CHROMagarCandida培养基显色培养与PCR扩增ITS1 ITS2 区域相结合的方式对 13例口腔念珠菌标本进行细胞及分子水平鉴定 ,并对CHROMagarCandida培养基能否引起念珠菌ITS1 ITS2 区域碱基序列改变问题进行探讨。结果 :13例念珠菌标本分别属于最常见的白色念珠菌、热带念珠菌及光滑念珠菌三种类型 ,并在CHROMagarCandida显色培养基上分别呈现出草绿色 (白色念珠菌 )、蓝灰色 (热带念珠菌 )以及紫红色 (光滑念珠菌 )菌落 ;这三种念珠菌类型在ITS1 ITS2 区域的片断长度或碱基序列上表现出特异性差异。结论 :使用PCR扩增ITS1 ITS2 区域的方法可以对以上三种临床念珠菌进行准确鉴定及种内分型。

Objective:To establish a rapid and accurate protocol for the classification of oral Candida species.Method:Using PCR amplification of ITS 1-ITS 2 regions combined with CHROMagar Candida medium culture to have characterized 13 clinical isolates of Candidas, and explored whether CHROMagar Candida can induce sequence changes of ITS 1-ITS 2 regions in these opportunity fungi.Result:On the CHROMagar culture, these isolates appear to be categorized into three color types, green, blue and red, respectively representing C. albican, C. Tropicalias, and C. glabrates, three most common oral fungi of clinical significance. This is further revealed by sequencing analysis of ITS 1-ITS 2 regions of these isolates after PCR amplification, in which each fungi species shows a characteristic fragment length or sequence specificity which is not affected by the CHROMagar Candida medium culture.Conclusion:Characteristic sequence features of ITS 1-ITS 2 regions of Candida species can be utilized as molecular markers to classify clinically significant Candidas.