Yim Seon Mi, Kim Ji Young, Ko Jong Hyun, Lee Yang Won, Choe Yong Beom, Ahn Kyu Joong
Department of Dermatology, Konkuk University School of Medicine, Seoul, Korea.
Ann Dermatol. 2010 Feb;22(1):41-7. doi: 10.5021/ad.2010.22.1.41. Epub 2010 Feb 28.
The yeasts of the genus Malassezia are members of the normal flora on human skin and they are found in 75~80% of healthy adults. Since its association with various skin disorders have been known, there have been a growing number of reports that have implicated Malassezia yeast in atopic dermatitis (AD).
The aim of the present study is to isolate the various Malassezia species from AD patients by using 26S rDNA (ribosomal Deoxyribonucleic acid) PCR-RFLP and to investigate the relationship between a positive Malassezia culture and the severity of AD.
Cultures for Malassezia yeasts were taken from the scalp, cheek, chest, arm and thigh of 60 patients with atopic dermatitis. We used a rapid and accurate molecular biological method 26S rDNA PCR-RFLP, and this method can overcome the limits of the morphological and biochemical methods.
Positive Malassezia growth was noted on 51.7% of the patients with atopic dermatitis by 26S rDNA PCR-RFLP analysis. The overall dominant species was M. sympodialis (16.3%). M. restricta was the most common species on the scalp (30.0%) and cheek (16.7%). M. sympodialis (28.3%) was the most common species on the chest. The positive culture rate was the highest for the 11~20 age group (59.0%) and the scalp showed the highest rate at 66.7%. There was no significant relationship between the Malassezia species and SCORing for Atopic Dermatitis (SCORAD).
The fact that the cultured species was different for the atopic dermatitis lesion skin from that of the normal skin may be due to the disrupted skin barrier function and sensitization of the organism induced by scratching in the AD lesion-skin. But there was no relationship between the Malassezia type and the severity score. The severity score is thought to depend not on the type, but also on the quantity of the yeast.
马拉色菌属酵母菌是人类皮肤正常菌群的成员，在75%至80%的健康成年人中均可发现。自从其与各种皮肤疾病的关联被知晓以来，越来越多的报告表明马拉色菌酵母与特应性皮炎（AD）有关。
本研究的目的是通过使用26S核糖体脱氧核糖核酸（rDNA）聚合酶链反应-限制性片段长度多态性分析（PCR-RFLP）从AD患者中分离出各种马拉色菌种，并研究马拉色菌培养阳性与AD严重程度之间的关系。
从60例特应性皮炎患者的头皮、脸颊、胸部、手臂和大腿采集马拉色菌酵母培养物。我们使用了一种快速准确的分子生物学方法——26S rDNA PCR-RFLP，该方法可以克服形态学和生化方法的局限性。
通过26S rDNA PCR-RFLP分析，51.7%的特应性皮炎患者马拉色菌生长呈阳性。总体优势菌种是合轴马拉色菌（16.3%）。限制马拉色菌是头皮（30.0%）和脸颊（16.7%）上最常见的菌种。合轴马拉色菌（28.3%）是胸部最常见的菌种。11至20岁年龄组的阳性培养率最高（59.0%），头皮的阳性率最高，为66.7%。马拉色菌种与特应性皮炎评分（SCORAD）之间没有显著关系。
特应性皮炎皮损皮肤培养出的菌种与正常皮肤不同，这一事实可能是由于AD皮损皮肤的皮肤屏障功能破坏以及搔抓引起的机体致敏。但马拉色菌类型与严重程度评分之间没有关系。严重程度评分被认为不仅取决于酵母的类型，还取决于其数量。
