Pujol Claude, Pfaller Michael, Soll David R
Department of Biological Sciences, University of Iowa, Iowa City 52242, USA.
J Clin Microbiol. 2002 Aug;40(8):2729-40. doi: 10.1128/JCM.40.8.2729-2740.2002.
It was previously demonstrated by a cluster analysis that 26 unrelated U.S. isolates of Candida albicans separated into three distinct groups (groups I, II, and III) while South African isolates separated into four distinct groups (groups I, II, III, and SA). To verify the absence or underrepresentation of SA isolates in North America, and to identify which groups are represented in Europe and South America, collections of bloodstream isolates from each geographical locale were analyzed by cluster analyses based on genetic fingerprinting with the Ca3 probe. The results verify that North America is almost devoid of SA isolates (2%). However, the results reveal a new clade, designated group E, relatively specific to Europe. While 26% of a European collection of 46 isolates was composed of group E isolates, only 2% of the 164 North American isolates, 5% of 22 South American isolates, and 1% of 361 South African isolates were composed of group E isolates. The North American collection proved to be the least-diverse collection in regard to group representation. In a comparison of collections from the Northeast, Midwest, and Southwest regions of the United States, Canada, and South America, it was demonstrated that both the U.S. Southwest and the South American collections were devoid of group II isolates. Together these results identify for the first time a European-specific clade and demonstrate clear distinctions in the representations of the five demonstrated clades (groups I, II, III, SA, and E) in different geographical locales.
先前通过聚类分析表明,26株来自美国的白色念珠菌非相关分离株分为三个不同的组(I组、II组和III组),而南非分离株分为四个不同的组(I组、II组、III组和SA组)。为了验证北美地区SA分离株是否缺失或数量不足,并确定欧洲和南美地区存在哪些组,我们基于Ca3探针的基因指纹分析,通过聚类分析对每个地理区域的血流分离株进行了分析。结果证实北美地区几乎没有SA分离株(2%)。然而,结果揭示了一个新的进化枝,命名为E组,相对特异地存在于欧洲。在欧洲收集的46株分离株中,26%是E组分离株,而在164株北美分离株中只有2%、22株南美分离株中有5%、361株南非分离株中有1%是E组分离株。就组的代表性而言,北美收集的样本是多样性最少的。在美国、加拿大和南美地区的东北部、中西部和西南部地区收集的样本比较中,结果表明美国西南部和南美地区的样本中没有II组分离株。这些结果共同首次确定了一个欧洲特有的进化枝,并证明了五个已证实的进化枝(I组、II组、III组、SA组和E组)在不同地理区域的代表性存在明显差异。