我国首见由地霉引起的脓癣一例及实验研究

目的 报道我国首见由地霉所致脓癣一例。方法 患者为9岁男孩,头部出现脓癣样皮损,耳后淋巴结肿大,全面临床检查排除其他疾病。取头顶皮损表面痂皮及病发多次真菌培养、直接镜检证实为真菌病;通过真菌培养、扫描电镜、生化学实验及DNA序列分析进行菌种鉴定;通过扫描电镜及毛发受侵试验观察菌株对毛发的感染情况;通过动物试验观察菌株的致病力;观察临床抗真菌治疗效果及体外药敏实验。结果 真菌学培养均有同样菌落生长,菌落表面平坦,27℃培养边缘有菌丝生长,37℃培养为湿润的酵母样菌落。镜下见大小不一的矩形关节孢子及大量圆形或卵圆形孢子,出芽或不出芽,并可见有分支的菌丝。菌种经生化学实验等鉴定为地霉菌,DNA序列分析证实该菌属于昔维考拉地霉(Geotrichum silvicola)或其姐妹株。动物实验证明该菌有致病性。经特比萘芬治疗4周后好转,真菌学检查阴性。结论 此例地霉所致脓癣为我国首见;特比萘芬治疗可以治愈。

Kerion Caused by Geotrichum in China:First Case Report in China

Objective To report a case of kerion caused by Geotrichum in China. Methods A 9 year-old-boy had kerion-form lesion on his scalp with swollen posterior auricular lymph nodes, and did not show other definite underlying disease. The pathogenic fungus was identified according to culture, scanning electron microscopy, biochemical tests and DNA sequencing. The hair infection test was performed and the infected hairs were examined by scanning electron microscope. Animal test confirmed the pathogenicity of the fungus. Results The fungal colonies were the same when the tissue cultures were repeated. The colonies showed milky white to yellowish in color. The hyphae could be identified at the periphery on Sabouraud's agar culture at 27℃, which were moist and smooth on the surface at 37℃. Under microscope, there were many rectangular arthrospores, round or oval spores with or without buddings, as well as branched hyphae. The isolated fungus was identified as a Geotrichum silvicola by culture, scanning electron microscope, biochemical test and DNA sequencing. The patient's condition was improved markedly after treatment of terbinafine for 4 weeks. Conclusions This is the first case report of kerion caused by Geotrichum in China, and terbinafine is effective.