Gilgado Felix, Cano Josep, Gené Josepa, Guarro Josep
Unitat de Microbiologia Facultat de Medicina i Ciencias de la Salut, Universitat Rovira i Virgili C/Sant Llorenç 21, 43201 Reus, Tarragona, Spain.
J Clin Microbiol. 2005 Oct;43(10):4930-42. doi: 10.1128/JCM.43.10.4930-4942.2005.
Pseudallescheria boydii (anamorph Scedosporium apiospermum) is the species responsible for human scedosporiosis, a fungal infection with a high mortality rate and which is difficult to treat. Recently, it has been demonstrated that high genetic variation exists within this species. We have performed a morphological and molecular study involving numerous strains of clinical or environmental origins and from different countries. The analysis of partial sequences of the beta-tubulin (two loci) and calmodulin genes and the internal transcribed spacer region of the rRNA gene has demonstrated that P. boydii is a species complex. The combined analysis of the sequences of the four loci of 60 strains has showed the presence of 44 haplotypes in the in group. Three species morphologically related to P. boydii sensu stricto, i.e., Pseudallescheria angusta, Pseudallescheria ellipsoidea, and Pseudallescheria fusoidea, which had previously been considered synonyms, could be differentiated genetically from P. boydii in our study. It is relevant that two of the three strains now included in P. ellipsoidea have caused invasive infections. The species Pseudallescheria minutispora and Scedosporium aurantiacum are clearly phylogenetically separated from the other species studied and are here proposed as new. Morphological features support this proposal. All the strains included in S. aurantiacum species have a clinical origin, while those included in P. minutispora are environmental. Further studies are needed to demonstrate whether all the species included in the P. boydii complex have different clinical spectra and antifungal susceptibility.
博伊德假阿利什霉（无性型为尖端赛多孢）是导致人类赛多孢菌病的病原菌，这是一种死亡率高且难以治疗的真菌感染。最近，已证明该菌种内存在高度的遗传变异。我们对众多临床或环境来源、来自不同国家的菌株进行了形态学和分子研究。对β-微管蛋白（两个位点）、钙调蛋白基因以及rRNA基因的内部转录间隔区的部分序列分析表明，博伊德假阿利什霉是一个复合种。对60个菌株的四个位点序列的综合分析显示，类群内存在44种单倍型。在我们的研究中，三种在形态上与狭义博伊德假阿利什霉相关的菌种，即狭假阿利什霉、椭圆假阿利什霉和梭形假阿利什霉，此前被认为是同义词，现在可以从遗传上与博伊德假阿利什霉区分开来。值得注意的是，现在归入椭圆假阿利什霉的三个菌株中有两个引起了侵袭性感染。微小假阿利什霉和橙色赛多孢在系统发育上与其他研究的菌种明显分开，在此被提议为新种。形态学特征支持这一提议。橙色赛多孢种内的所有菌株均来自临床，而微小假阿利什霉种内的菌株均来自环境。需要进一步研究以证明博伊德假阿利什霉复合种内的所有菌种是否具有不同的临床谱和抗真菌药敏性。
