念珠菌碱溶性β-葡聚糖水解生成葡萄糖含量的分类鉴定意义

Study on the taxonomic identification value of the content of glucose hydrolyzed from alkali-soluble β-glucan of Candida

目的 : 探讨 8种医学上重要的念珠菌酵母相胞壁碱溶性 β -葡聚糖水解生成的D -葡萄糖占菌体干重含量百分率的分类鉴定意义。方法 : 采用双波长薄层扫描法 ,测定 6 5株 8种念珠菌及 8种酿酒酵母的标准菌株上述含量值 ,并检测 46株念珠菌临床分离株 ,且与标准株结果相比较。结果 :实验结果经Tukey法统计处理 ,可将 9种菌分为 3个同质性亚群 ,亚群 1:酿酒酵母、克柔、季也蒙、光滑、热带念珠菌 (P =0 .0 6 5 ) ,亚群 2 :克柔、季也蒙、光滑、热带、近平滑、伪热带、星形念珠菌 (P =0 .336 ) ,亚群 3:白念珠菌 (P =1.0 0 0 )。此外 ,酿酒酵母与 8种念珠菌经t检验 ,均有显著性差异。临床分离株与标准株均无显著性差异。结论 : 该指标能在属水平区分念珠菌和酿酒酵母 ,可将 8种念珠菌分为 3个亚群 ;且重复性较好。因此似能作为一种念珠菌分类鉴定研究的化学分类法指标。

Objectives: To investigate the significance of potential taxonomic identification index of Candida, of which D-glucose hydrolyzed from alkali-soluble β-glucan of cell wall accounts for the percentage of yeast phase cells' dry weight in 8 medically important species of Candida.Methods:We used dual-wavelength thin-layer scanning technique to determine the glucose content of standard strains of Candida (65 strains) and Saccharomyces cerevisiae (8 strains). At the same time, 46 clinical isolates of Candida were determined and compared with standard strains.Results: By using Tukey test, the results showed that 9 species could be classified into 3 following homogeneous subsets:(1)S. cerevisiae, C. krusei, C. guilliermondii, C. glabrata, and C. tropicalis (P= 0.065); (2)C. krusei, C. guilliermondii, C. glabrata, C. tropicals, C. parapsilosis, C. pseudotropicalis, and C. stellatoidea (P=0.336), and (3)C. albicans alone (P=1.000). But by t test, there were significant differences between S. cerevisiae and 8 species of Candida. Comparing with standard strains, clinical isolates had no significant difference. Conclusion: It is suggested that this index can identify Candida from S. cerevisiae on genus level, and it can classify 8 species of Candida into 3 homogeneous subsets. The results reveal that this index can be duplicated, and it has a potential taxonomic identification value.