Brasch J, Müller S, Gräser Y
Department of Dermatology, University Hospitals of Schleswig-Holstein, Campus Kiel, Kiel, Germany.
Institute of Microbiology and Hygiene, Charité, Berlin, Germany.
Mycoses. 2015 Oct;58(10):573-7. doi: 10.1111/myc.12358. Epub 2015 Aug 7.
We comment on an unusual strain of Microsporum (M.) audouinii. It was isolated from tinea corporis of a boy who lived in Germany and most likely had acquired his infection during a stay on a farm with animal husbandry in Poland. The strain showed features of M. canis (plenty of markedly rough-walled macroconidia, growth on rice, positive hair perforation) as well as of M. audouinii (white thallus, long macroconidia with central constriction) and in vitro it degraded hair of various mammals. Because its ribosomal internal transcribed spacer region showed 99.9% homology to a M. audouinii reference strain it was finally identified as M. audouinii. We relate these findings with recent observations of M. audouinii causing tinea in Europe. This appraisal suggests that irrespective of an identical ribosomal ITS region distinct M. audouinii strains can display a spectrum of morphological and physiological features that is broader than currently outlined in mycological textbooks. Certain unusual characteristics like an enhanced capacity to utilise keratins may even be associated with unexpected transmission routes. Above all sporadic M. audouinii infections in Europe that bear no relation to an endemic area should be analysed from this perspective.
我们对一株不寻常的奥杜盎小孢子菌（Microsporum (M.) audouinii）进行了评论。它是从一名居住在德国的男孩的体癣中分离出来的，该男孩很可能是在波兰一个从事畜牧业的农场逗留期间感染的。该菌株表现出犬小孢子菌（M. canis）的特征（大量明显粗糙壁的大分生孢子、在大米上生长、毛发穿孔试验阳性）以及奥杜盎小孢子菌（M. audouinii）的特征（白色菌落、有中央缢缩的长形大分生孢子），并且在体外它能降解各种哺乳动物的毛发。由于其核糖体内部转录间隔区与一株奥杜盎小孢子菌参考菌株显示出99.9%的同源性，最终它被鉴定为奥杜盎小孢子菌。我们将这些发现与最近在欧洲观察到的奥杜盎小孢子菌引起癣病的情况联系起来。这种评估表明，尽管核糖体ITS区域相同，但不同的奥杜盎小孢子菌菌株可能表现出比目前真菌学教科书中所概述的更广泛的形态和生理特征谱。某些不寻常的特征，如增强的角蛋白利用能力，甚至可能与意想不到的传播途径有关。最重要的是，应该从这个角度分析欧洲与疫区无关的散发性奥杜盎小孢子菌感染病例。
