Ahmad Suhail, Al-Mahmeed Manal, Khan Zia U
Department of Microbiology, Faculty of Medicine, Kuwait University, PO Box 24923, Safat 13110, Kuwait.
J Med Microbiol. 2005 Jul;54(Pt 7):639-646. doi: 10.1099/jmm.0.45972-0.
Invasive trichosporonosis is an emerging infection of severely immunocompromised patients. It is principally caused by Trichosporon asahii, although some other species of the genus have also been implicated in the aetiology. In this work, 29 clinical isolates of Trichosporon species recovered from 29 different patients over a 6-year period were studied for phenotypic and genotypic characteristics. Two morphotypes were recognized on the basis of colony characteristics. The colonies of 25 isolates appeared flat and centrally wrinkled, while the other four isolates appeared dry and irregularly folded or verrucosed. Based on substrate assimilation profiles, all 29 isolates were identified as T. asahii using the Vitek 2 system. However, PCR amplification of rRNA gene sequences identified only 25 of the 29 isolates as T. asahii. The identity of the remaining four isolates was established as Trichosporon asteroides by direct DNA sequencing of the internally transcribed spacer (ITS)-1 and ITS-2 regions in the rRNA gene fragment amplified by PCR using panfungal primers. Fingerprinting carried out by randomly amplified polymorphic DNA analysis showed genotypic heterogeneity among the 25 T. asahii and four T. asteroides isolates. These data suggest that T. asahii is the major species associated with clinical specimens in Kuwait.
侵袭性毛孢子菌病是一种在严重免疫功能低下患者中出现的感染性疾病。其主要由阿萨希毛孢子菌引起，不过该属的其他一些菌种也被认为与病因有关。在这项研究中，对6年间从29名不同患者身上分离出的29株毛孢子菌临床菌株进行了表型和基因型特征研究。根据菌落特征识别出两种形态型。25株菌株的菌落呈扁平状且中央有褶皱，而另外4株菌株的菌落则显得干燥，呈不规则折叠状或疣状。基于底物同化谱，使用Vitek 2系统将所有29株菌株鉴定为阿萨希毛孢子菌。然而，rRNA基因序列的PCR扩增仅将29株菌株中的25株鉴定为阿萨希毛孢子菌。通过使用泛真菌引物对PCR扩增的rRNA基因片段中的内转录间隔区（ITS）-1和ITS-2区域进行直接DNA测序，确定其余4株菌株为星状毛孢子菌。通过随机扩增多态性DNA分析进行的指纹图谱显示，25株阿萨希毛孢子菌和4株星状毛孢子菌菌株之间存在基因型异质性。这些数据表明，阿萨希毛孢子菌是科威特与临床标本相关的主要菌种。
