Mycology Unit, Medical School, Universitat Rovira i Virgili, C/Sant Lorenç 21, 43201 Reus Tarragona, Spain.
J Clin Microbiol. 2011 Jan;49(1):243-56. doi: 10.1128/JCM.00793-10. Epub 2010 Nov 10.
Some species in the polyphyletic fungal genus Acremonium are important opportunist pathogens. Determining the actual spectrum of species and their incidence in the clinical setting, however, has long been hampered because of the difficulties encountered in phenotypic species-level identification. The goal of this study was to re-identify a large number of clinical isolates morphologically and to confirm the identifications by comparing sequences of the internal transcribed spacer region of the rRNA gene of these isolates to those of type or reference strains of well-known Acremonium species. Of the 119 isolates referred to a United States reference laboratory under the name Acremonium, only 75 were identified morphologically as belonging to that genus. The remainder (44 isolates) were identified as belonging to other morphologically similar genera. The Acremonium clinical isolates were related to species of Hypocreales, Sordariales, and of an incertae sedis family of ascomycetes, Plectosphaerellaceae. A total of 50 of the 75 Acremonium isolates (67%) could be identified by molecular means, the prevalent species being Acremonium kiliense (15 isolates), A. sclerotigenum-A. egyptiacum (11 isolates), A. implicatum (7 isolates), A. persicinum (7 isolates), and A. atrogriseum (4 isolates). One of the most interesting findings of our study was that we identified several species among this large collection of clinical isolates that had not previously been reported from human infections, and we failed to confirm other Acremonium species, such as A. potronii, A. recifei, and A. strictum, that had been considered significant. The most common anatomic sites for Acremonium isolates were the respiratory tract (41.3%), nails (10.7%), and the eye (9.3%). Antifungal susceptibility testing demonstrated high MICs for all agents tested, except for terbinafine. Since numerous isolates could not be identified, we concluded that the list of opportunistic Acremonium species is far from be complete and that a considerable number of additional species will be discovered.
一些多系真菌枝顶孢属的物种是重要的机会性病原体。然而，由于在表型种水平鉴定方面遇到困难，长期以来一直难以确定实际的物种谱及其在临床环境中的发生率。本研究的目的是重新鉴定大量临床分离株，并通过将这些分离株的核糖体 RNA 基因内部转录间隔区序列与已知枝顶孢属物种的型或参考株的序列进行比较，来确认鉴定结果。在美国的一个参考实验室中，以枝顶孢属的名义被鉴定的 119 个分离株中，只有 75 个在形态上被鉴定为属于该属。其余（44 个分离株）被鉴定为属于其他形态相似的属。枝顶孢属的临床分离株与子囊菌门的 Hypocreales、Sordariales 和一个未确定的科（Plectosphaerellaceae）有关。通过分子手段可以鉴定出 75 个枝顶孢属分离株中的 50 个（67%），流行的物种是枝顶孢（15 个分离株）、A. sclerotigenum-A. egyptiacum（11 个分离株）、A. implicatum（7 个分离株）、A. persicinum（7 个分离株）和 A. atrogriseum（4 个分离株）。我们研究的一个最有趣的发现是，我们在这个大型临床分离株集中鉴定出了一些以前从未在人类感染中报告过的物种，并且我们未能确认其他枝顶孢属物种，如 A. potronii、A. recifei 和 A. strictum，这些物种曾被认为是重要的。枝顶孢属分离株最常见的解剖部位是呼吸道（41.3%）、指甲（10.7%）和眼睛（9.3%）。抗真菌药敏试验显示，除特比萘芬外，所有测试药物的 MIC 均较高。由于许多分离株无法鉴定，我们得出结论，机会性枝顶孢属物种的清单远未完成，还会发现相当数量的其他物种。
