Facultad de Ciencias Biológicas, Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Urbanización San Andrés Trujillo, Peru.
Infect Genet Evol. 2010 Jul;10(5):697-702. doi: 10.1016/j.meegid.2010.03.007. Epub 2010 Mar 27.
Candida albicans population studies showed that this species could be divided into sub-groups of closely related strains, designated by clades. Since the emergence of microsatellite analysis as a PCR based method, this technique has been successfully used as a tool to differentiate C. albicans isolates but has never been tested regarding clustering of the five major clades. In this study we tested microsatellite length polymorphism (MLP) ability to group 29 C. albicans strains previously defined as belonging to clades I, II, III, E and SA, nine atypical strains from Angola and Madagascar, and 78 Portuguese clinical isolates. MLP typing of the total 116 strains analyzed yielded 87 different multilocus allelic combinations which resulted in a high discriminatory power index, of 0.987, with only two markers, CA1 and CEF3. Cluster analysis of the 29 previously defined strains grouped them according to their clade designation with a matrix cophenetic correlation of r=0.963 after a normalized Mantel statistic. Clustering analysis of the 116 strains maintained the same groupings, clearly defining the five major C. albicans clades. The cophenetic value obtained was of r=0.839, and the one-tail probability of the normalized Mantel statistic out of 1000 random permutations was P=0.0020. The proportion of Portuguese isolates in the groups I, II, III and SA was of 2.7%, 15.4%, 3.8% and 0%, respectively. None of the isolates co-clustered with the atypical strains. These results confirm MLP typing as a good method both to type and differentiate C. albicans isolates and to group isolates, identifying the major C. albicans clades, similarly to Ca3 fingerprinting and multilocus sequence typing (MLST).
白色念珠菌种群研究表明，该物种可分为密切相关菌株的亚群，称为进化枝。自从微卫星分析作为一种基于 PCR 的方法出现以来，这项技术已成功地用作区分白色念珠菌分离株的工具，但从未针对五个主要进化枝的聚类进行过测试。在这项研究中，我们测试了微卫星长度多态性（MLP）将 29 株先前被定义为属于 I、II、III、E 和 SA 进化枝的白色念珠菌菌株、来自安哥拉和马达加斯加的 9 株非典型菌株以及 78 株葡萄牙临床分离株进行分组的能力。对分析的 116 株总菌株的 MLP 分型产生了 87 种不同的多位点等位基因组合，这导致了高鉴别力指数，为 0.987，仅使用了两个标记物 CA1 和 CEF3。对 29 株先前定义的菌株进行聚类分析，根据其进化枝命名将它们分组，归一化曼特尔统计后的矩阵cophenetic 相关系数 r=0.963。对 116 株菌株的聚类分析保持了相同的分组，清楚地定义了五个主要的白色念珠菌进化枝。获得的 cophenetic 值为 r=0.839，在 1000 次随机置换的归一化曼特尔统计的单尾概率为 P=0.0020。I、II、III 和 SA 组中葡萄牙分离株的比例分别为 2.7%、15.4%、3.8%和 0%。没有分离株与非典型菌株共同聚类。这些结果证实 MLP 分型是一种很好的方法，既可以对白色念珠菌分离株进行分型和区分，又可以对分离株进行分组，确定主要的白色念珠菌进化枝，类似于 Ca3 指纹图谱和多位点序列分型（MLST）。
