Department of Medical Parasitology & Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Med Mycol. 2012 Oct;50(7):760-4. doi: 10.3109/13693786.2012.661885. Epub 2012 Feb 28.
Trichophyton tonsurans and T. equinum are two closely related sister species of dermatophytes, but differ in their preferred hosts, i.e., humans or horses, respectively. Routine procedures for their identification depend on studies of their phenotypic, physiological and biochemical characteristics, which are laborious and may yield ambiguous results. Molecular methods using rDNA ITS also had been judged to be insufficiently discriminatory. In the present study two genetic markers were sequenced in addition to the ITS region, i.e., partial β-tubulin (BT2) and translation elongation factor 1-α (TEF1). The TEF1 locus revealed a consistent differences in a 13 bp indel and an additional SNP between the two species, along with a single base substitution in BT2 and one ITS1, enabling unambiguous distinction of the two taxa. RFLP targeting the ITS region was evaluated as a potential tool for routine screening of suspected isolates of T. tonsurans and T. equinum.
须毛癣菌和马毛癣菌是两种密切相关的亲表皮癣菌，但其宿主偏好不同，分别为人类和马。其鉴定的常规程序取决于对其表型、生理和生化特征的研究，这些研究既繁琐又可能产生模棱两可的结果。使用 rDNA ITS 的分子方法也被认为是不够有区别力的。在本研究中，除了 ITS 区之外，还对两个遗传标记进行了测序，即部分β-微管蛋白（BT2）和翻译延伸因子 1-α（TEF1）。TEF1 基因座在 13 bp 插入缺失和两个物种之间的一个额外 SNP 方面显示出一致的差异，同时在 BT2 和一个 ITS1 中存在一个单碱基取代，能够明确区分这两个分类单元。针对 ITS 区的 RFLP 被评估为一种潜在的工具，可用于常规筛选疑似须毛癣菌和马毛癣菌的分离株。
