RAPD differentiation of Malassezia spp. from cattle, dogs and humans

The molecular characterization of Malassezia spp. isolates from animals and humans has not been thoroughly studied. We have analysed the DNA profile by random amplified polymorphic DNA (RAPD)–PCR to compare the genetic diversity between isolates from the external ears of cattle, dogs and humans. The analysis of electrophoretic profiles on 8% polyacrylamide gel and their phenograms showed genetic heterogeneity between RAPD profiles of Malassezia furfur and Malassezia slooffiae isolates from humans and cattle and between Malassezia pachydermatis isolates from dogs and cattle. Intra-species variations in DNA pattern of Malassezia isolates and the presence of specific genetic types in cattle, dogs or humans were observed. A review of genetic heterogeneity of these yeast in veterinary and human medicine studies is given considering a possible transmission animal to human or human to animal. Additional studies must clarify the differences between the RAPD band patterns observed in this and other studies, which would facilitate monitoring of Malassezia spp. carriage in domestic animals and in humans.     

马拉色菌在花斑癣色素改变中的作用

目的 观察引起不同临床色素表现的马拉色菌与角质形成细胞（KC）共培养液对B16F10黑素瘤细胞黑素合成的影响，及共培养液中与黑素合成相关的细胞因子产生情况。方法 将1 × 106/mL KC与分离自色素沉着区的马拉色菌（简称C株）、分离自色素减退区的马拉色菌（简称J株）按4个浓度比例（KC ∶ 马拉色菌为1 ∶ 1、1 ∶ 10、1 ∶ 20、1 ∶ 30）分别共培养，用MTT法测定KC增殖率。将C株或J株马拉色菌分别加入KC培养体系共培养，真菌孢子和KC密度均为1 × 106/mL（1 ∶ 1），制备的培养液分5组，KC单独培养液、C株或J株马拉色菌与KC共培养液、C株或J株马拉色菌单独培养后再次培养KC的二次培养液，用上述各组培养液分别培养B16F10细胞，用MTT法测量各组B16F10细胞增殖率，NaOH裂解法测量黑素含量，Western印迹法测定酪氨酸酶和β-肌动蛋白的表达，多巴氧化法测定酪氨酸酶活性。ELISA法测定各组培养液中细胞因子的浓度。结果 KC与马拉色菌在1 ∶ 10比例以下，KC的生长不受马拉色菌的影响。C株马拉色菌与KC共培养液引起B16F10细胞黑素含量、酪氨酸酶活性和酪氨酸酶蛋白表达增加，细胞增殖率无明显变化。J株马拉色菌共培养液的作用与之相反。C株马拉色菌刺激产生的内皮素1显著高于J株马拉色菌（P < 0.01）。结论 马拉色菌通过与KC相互作用，影响B16F10细胞酪氨酸酶的活性和表达，调节黑素合成。内皮素1在花斑癣色素沉着中可能起一定作用。     

脂溢性皮炎与马拉色菌的关系及相关治疗研究进展

脂溢性皮炎好发于皮脂腺丰富区,是一种慢性炎症性皮肤病。症状包括出现鳞屑,片状皮屑,瘙痒,以及潮红或红斑。普通人群中发病率为3%,虽然病因尚未完全清楚,但已知马拉色菌(Malassezia)是其主要致病因素之一。因此,文章将针对性地对脂溢性皮炎与马拉色菌的关系进行综述,并且在分析过去对马拉色菌性脂溢性皮炎的治疗方法的利弊基础上,提出新的治疗思路。     

A new ketoconazole topical gel formulation in seborrhoeic dermatitis: an updated review of the mechanism

Seborrhoeic dermatitis (SD) is a chronic, inflammatory skin disorder, affecting areas of the head and body where sebaceous glands are most prominent and active. The disorder commonly affects hair-bearing areas of the head, including the scalp. Involvement on the face is usually limited to the hairline, eyebrows, nasolabial folds and ears, and may occur either with or without scalp involvement. Areas of the trunk where SD may occur include the body folds and the presternal area. The aetiology of SD is unknown, although hormones and the Malassezia spp., formerly known as Pityrosporum (naturally occurring yeasts), are thought to be involved in the development of the condition. SD responds to the use of antifungal medications such as ketoconazole, suggesting that the inflammation could be linked to the Malassezia spp. The mechanisms behind the therapeutic effect of ketoconazole for the management of SD form the basis of this review. The broad spectrum activity of Ketoconazole was reported in the early 1980s. Due to its potent effect against Malassezia spp. the development of ketoconazole for the treatment of various skin infections, in which a link was proposed with Malassezia spp., was initiated. Later on, a number of ancillary properties were described for ketoconazole, comprising antibacterial, anti-inflammatory, sebostatic and antiproliferative effects. The incorporation of ketoconazole in an adapted vehicle further promoted its efficacy. Recently, a new anhydrous gel containing 2% ketoconazole (Xolegel?) was launched, in which all of the above properties were optimised.     

1%联苯苄唑乳膏治疗马拉色菌毛囊炎临床疗效观察

目的: 观察1%联苯苄唑乳膏治疗马拉色菌毛囊炎的临床疗效和安全性.方法:选择80例马拉色菌毛囊炎患者,治疗组(40例)外用1%联苯苄唑乳膏,每日1次,连续3周;对照组(40例)外用2%酮康唑洗剂.结果:3周疗程结束时治疗组临床整体疗效(用药后症状/体征积分下降指数)优于对照组(P<0.05),两组间真菌学清除率相当(P>0.05).结论:1%联苯苄唑乳膏治疗马拉色菌毛囊炎疗效确切,安全性好.     

哺乳期女性皮肤马拉色菌菌种调查

目的了解哺乳期女性皮肤马拉色菌带菌和菌种构成情况。方法采用胶带法粘取哺乳期女性胸前皮屑,接种于含菜子油培养基进行真菌培养、分离马拉色菌,并用生理生化及形态学方法鉴定菌种。结果正常哺乳期妇女胸部皮肤马拉色菌培养阳性率为58.13%,主要为糠秕马拉色菌和合轴马拉色菌。结论正常哺乳期妇女胸部皮肤马拉色菌带菌和菌种情况与既往文献对正常人的报道不完全相同。     

Late-onset of IgE sensitization to microbial allergens in young children with atopic dermatitis

Background  A significant proportion of young children with atopic dermatitis (AD) is sensitized to microbial allergens, which play a potential role in the pathogenesis of AD inflammation.
Objective  To study the timing of IgE sensitization to microbial allergens including staphylococcal superantigens, Malassezia species and Candida albicans in young children with AD.
Method  Specific IgE antibodies to staphylococcal superantigens, Malassezia species, C. albicans and control inhalant/food allergens were measured in 53 young children with mild to moderate AD. The presence of IgE sensitization relative to age (≥ 3 years vs. < 3 years) was analysed by logistic regressions.
Results  IgE sensitization to the staphylococcal superantigen group, Malassezia species and C. albicans was significantly associated with older age in children with AD [ P  =   0·02, odds ratio (OR) 4·9; P  =   0·02, OR 4·7; and P  =   0·05, OR 4·0, respectively].
Conclusion  IgE sensitization to microbial allergens is associated with an older age group in young children with mild to moderate AD.     

正交设计优选10种中药对马拉色菌抑菌研究

目的研究10种中药对马拉色菌的抑制作用。方法分别采用微波、超声两种提取方法,以抑菌圈直径为检测指标,考察赤芍等10种中药对马拉色菌的抑制作用,筛选出作用较强的3种中药;运用正交试验设计,以功率、提取时间、料液比为考察因素,优选最佳提取工艺,并测定3种中药提取物的最小抑菌浓度(MIC)。结果筛选出赤芍、苍耳子和艾叶3种抑菌作用强的中药,其最佳工艺分别是,赤芍:微波功率150W,料液比1:8,提取时间20min;苍耳子:超声功率70W,料液比1:12,提取时间30 min;艾叶:超声功率为50W,料液比1:8,提取时间20min。最小抑菌浓度为:赤芍微波提取物0.02g/mL,苍耳子微波提取物0.01g/mL,艾叶超声提取物0.015g/mL。结论赤芍、苍耳子、艾叶各单味提取物对马拉色菌具有较强的抑制作用,且工艺简单、可靠。     

特比萘芬乳膏与维A酸胶囊联合治疗马拉色菌毛囊炎

目的 观察外用特比萘芬乳膏和口服维A酸胶囊联合治疗马拉色菌毛囊炎的疗效.方法 治疗组172例,采用维A酸胶囊 20 mg顿服,1次/d,同时皮损处外用特比萘芬乳膏,2次/d,连续治疗14 d.对照组126例,单纯口服维A酸胶囊,方法及疗程同治疗组.结果 治疗组:治愈59例,显效66例,有效28例,无效19例.治愈率77.27%,总有效率为93.94%,对照组:治愈27例,显效32例,有效31例,无效36例.治愈率53.3%,总有效率为78.33%.两组治愈率和总有效率比较差异有显著性(P<0.05).结论 维A酸胶囊联合外用特比奈芬乳膏治疗马拉色菌性毛囊炎效果理想,副作用少而轻微.