球形马拉色菌是马拉色菌毛囊炎患者皮损毛囊内的主要菌种

目的 确定引起马拉色菌毛囊炎的主要菌种,比较皮损毛囊内和毛周表面皮肤菌种是否一致,患者性别、年龄、病情与分离菌种的关系。方法 菜子油培养基培养,根据形态及生理生化特点进行鉴定。结果 从毛周表面皮肤分离的319株菌中鉴定出合轴马拉色菌247株(77.43%)、糠秕马拉色菌40株(12.54%)、球形马拉色菌27株(8.46%)、钝形马拉色菌5株(1.57%);从毛囊内分离的314株菌中鉴定出球形马拉色菌252株(80.25%)、合轴马拉色菌57株(18.15%)、糠秕马拉色菌4株(1.27%)、钝形马拉色菌1株(0.32%),菌种构成差异有显著性(P<0.01)。毛囊内菌种构成与患者的性别和年龄有关,与病情无关。毛囊内和毛周表面皮肤同时阳性的279株中菌种不一致204株,菌种一致75株。结论 马拉色菌毛囊炎毛囊内的主要菌种为球形马拉色菌,其表面皮肤则以合轴马拉色菌为主。     

马拉色菌在新生儿皮肤定植的研究

目的探讨马拉色菌在新生儿皮肤的定植及影响因素。方法采用含菜籽油培养基32℃培养。对拟自然分娩的母亲临产时取阴道分泌物接种于试管斜面,用无菌微孔透气胶带粘取新生儿(8处皮肤,从出生当时到出院)、母亲(胸部和手掌,分娩后第2天)及其护士(手掌,新生儿出生后第2天)皮肤标本,接种于平板,根据菌落形态及生理生化方法鉴定菌种。结果①52份母亲阴道分泌物培养阴性。②15名护士共104份手掌部皮肤标本培养阴性。③104例新生儿(自然分娩和剖宫产各52例)出生当时的皮肤标本培养阴性,但出生后第1天有28例(26.92%)培养出马拉色菌,到第8天上升到59例(56.73%),其中糠秕马拉色菌41例(69.49%)。④从104例母亲皮肤上培养出马拉色菌65例(62.50%),其中糠秕马拉色菌49例(75.38%)。⑤母亲和新生儿124株马拉色菌中菌种相同者92例,一致率为74.19%。⑥新生儿前额和面颊马拉色菌培养阳性率最高。结论马拉色菌在新生儿皮肤定植最早发生在出生后的第1天内,主要部位为额面部,主要菌种为糠秕马拉色菌,存在于母亲皮肤的马拉色菌可能是定植菌种的主要来源。     

慢性湿疹患者皮肤马拉色菌的携带情况

目的分析慢性湿疹患者皮损区和非皮损区马拉色菌菌种的检出率以及菌种的构成,初步探讨马拉色菌与慢性湿疹关系。方法采用刮屑法刮取慢性湿疹患者及健康者皮屑,用马拉色菌培养基进行马拉色菌培养,并对培养结果进行常规菌种鉴定。结果慢性湿疹患者皮损部位与非皮损部位、健康人正常皮肤马拉色菌检出率比较,差异均有统计学意义(P<0.05);慢性湿疹患者非皮损部位与健康人正常皮肤马拉色菌检出率比较,差异无统计学意义(P>0.05)。慢性湿疹患者皮损内外菌种比较,差异有统计学意义(P<0.05)。结论马拉色菌与慢性湿疹有一定关系。     

湿疹和特应性皮炎皮损处细菌定植情况及药物联合治疗的分析

目的 探讨湿疹和特应性皮炎(AD)皮损处金黄色葡萄球菌(金葡菌)及其他细菌的定植情况,评价抗菌药物与糖皮质激素联合用药的疗效。方法 采用多中心、随机、双盲试验,在筛选日及治疗后第7、14和28天对皮损评分,并在皮损和非皮损处分离细菌。试验组外用抗菌药物和糖皮质激素,对照组外用基质和糖皮质激素。结果 共入选患者327例,湿疹208例,AD119例。湿疹皮损处细菌的阳性率为70.19%,金葡菌占47.26%;非皮损部位细菌阳性率为32.69%,金葡菌占27.94%。AD皮损处细菌阳性率为74.79%,金葡菌占79.78%;非皮损部位细菌阳性率为34.45%,金葡菌占80.49%。湿疹和AD皮损部位金葡菌的定植量均高于非皮损部位(P<0.01,P<0.05),细菌的定植量与皮损的严重程度呈正相关。两组患者治疗后总体疗效无明显差异(P>0.05),但湿疹临床症状评分指数>8分者及AD评分指数>7分者,在治疗的第7天,试验组与对照组的症状评分指数改善率存在显著差异(P<0.05),在治疗的第14天和第28天,两组差异均无显著性(P>0.05)。结论 湿疹和AD患者皮损部位细菌的检出率和金葡菌的带菌率均明显增高,说明金葡菌与湿疹皮炎的关系密切,早期联用抗菌药物可提高疗效。     

湿疹与特应性皮炎皮损处细菌学研究

目的 探讨湿疹和特应性皮炎(AD)皮损处的细菌学特点及金黄色葡萄球菌(金葡菌)在湿疹及AD发病中的作用。方法 多中心随机双盲对207例湿疹患者和119例AD患者皮损及非皮损处取材做细菌培养,并对所分离到的金葡菌进行常规药敏试验和噬菌体分型。结果 207例湿疹患者皮损处的细菌检出阳性率、金葡菌的比例及定植均明显高于非皮损处,差异有显著性(P<0.01)。119例AD患者皮损处的细菌检出阳性率及金葡菌的定植明显高于非皮损处,差异有显著性。对分离到的141株金葡菌进行噬菌体分型。Ⅰ组占6.3%,Ⅱ组占7.0%,Ⅲ组占3.5%,Ⅴ组占0.7%,杂组占1.4%,不能分型占56%,MRSA分型噬菌体26株混合组占6.3%。药敏试验结果表明在常用的6种外用抗菌药物中莫匹罗星对金葡菌和表皮葡萄球菌的抗菌活性最强,其MIC范围、MIC₉₀和MIC₅₀是6种抗菌药物中最低的。且莫匹罗星对金葡菌及其中的各噬菌体分型和表皮葡萄球菌中的耐甲氧西林和耐甲氧西林凝固酶阴性菌株也有较好的抑菌能力。结论 湿疹和AD的发病与细菌感染密切相关,其中金葡菌是最重要的细菌,对湿疹和AD患者外用药治疗合并使用外用抗菌药物是必要的,根据对金葡菌抗菌活性的测定,莫匹罗星的效果较好。     

银屑病皮损及非皮损中垂体腺苷酸环化酶激活肽及其受体的研究

目的 探讨垂体腺苷酸环化酶激活肽(PACAP)及其受体(PACAP-R)在银屑病发病中的意义。方法 采用免疫组化的方法研究寻常性银屑病患者皮损及非皮损部位PACAP及PACAP-R的原位表达情况。结果 银屑病患者皮损部位PACAP及PACAP-R的原位表达均明显低于非皮损部位,表现为皮损组PACAP及PACAP-R的面积密度及平均吸光度值显著低于正常人对照组(均为P<0.01);与正常人相比,非皮损部位PACAP及PACAP-R的原位表达也呈下调表达,即非皮损组的PACAP及PACAP-R的面积密度及平均吸光度值明显低于正常人对照组(P<0.05)。结论 PACAP及PACAP-R在银屑病皮损中下调表达,提示PACAP可能与银屑病表皮细胞的过度增殖有关。     

浙江地区108例花斑癣患者马拉色菌的分离及鉴定

花斑癣是临床常见病之一,发病时和病愈后常表现为色素减退斑或色素沉着斑,治愈后色素改变常需数月甚至数年后才能恢复正常。我们对花斑癣患者皮损和正常背部及上臂部皮肤皮屑作培养,以比较色素减退和色素沉着部位,皮损和正常部位马拉色菌菌种构成是否存在差异。     

婴儿头面部脂溢性皮炎马拉色菌带菌情况分析

目的了解患头面部脂溢性皮炎的婴儿与正常婴儿头面部马拉色菌带菌情况及来源分析。方法采用胶带法粘取脂溢性皮炎患儿头面部皮损及其母亲胸前皮肤、正常婴儿额部皮肤及其母亲胸前皮肤等处鳞屑,接种于含菜籽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①4组150例标本中共分离出101株马拉色菌;②脂溢性皮炎患儿与正常婴儿马拉色菌培养阳性率以及菌种构成差异均无显著性意义;③脂溢性皮炎患儿与正常婴儿分别与其母亲的马拉色菌培养阳性率以及菌种构成比较差异均无显著性意义,菌种存在一致性,但一致性较差。结论马拉色菌是患儿皮肤的常驻菌;脂溢性皮炎患儿及正常婴儿皮肤马拉色菌可能部分来源于母亲。     

马拉色菌与花斑癣色素改变的相关性初探

目的探讨马拉色菌与花斑癣皮疹色素改变及色氨酸产色三者之间的关系.方法从花斑癣患者皮损分离马拉色菌株,采用国际通用的生化鉴定方法鉴定,然后在不同浓度L-色氨酸的培养基上培养7 d,观察产色反应.结果每个菌种均有产色反应阳性和阴性菌株,产色反应阳性菌株更易引起皮损色素沉着(P＜0.005),且产色反应阳性标本颜色按色氨酸浓度递减而变淡.结论菌株的产色反应与马拉色菌的种属分类无必然的联系,色氨酸参与了马拉色菌产色反应.     

从包皮龟头炎患者皮损处分离鉴定马拉色菌

目的：了解马拉色菌属各菌种在包皮龟头炎皮损处的构成及其在发病中的作用。方法：从患处取材直接镜检查见马拉色菌孢子和(或)菌丝的包皮龟头炎患者作为研究对象。用胶带法取材后分别接种在含菜子油的培养基及无放线菌酮的沙堡培养基分离菌种。依据生理生化和形念学特点及转种到科玛嘉显色培养基和米粉吐温80琼脂培养结果鉴定出马拉色菌和(或)念珠菌。结果：81例患者中有57例(70．37％)培养并鉴定出马拉色菌(共60株)，其中糠秕马拉色菌20株(33．33％），合轴马拉色菌18株(30．00％)，钝形马拉色菌17株(28．33％)，球形马拉色菌5株(8．33％)。有37例同时分离到念珠菌(其中72．97％为白念珠菌）。44例仅检出马拉色菌的患者中有23例接受抗真菌治疗。结论：糠秕马拉色菌、合轴马拉色菌、钝形马拉色菌是包皮龟头炎患者皮损处的主要菌种；马拉色菌可能单独或与念珠菌协同引起包皮龟头炎。     

Molecular analysis of Malassezia microflora in the lesional skin of psoriasis patients

Systemic and focal infections by microorganisms have been known to induce or exacerbate psoriasis. To investigate the role of Malassezia species in the development of psoriasis, we analyzed the Malassezia microflora in psoriasis patients using a nested polymerase chain reaction (PCR) assay, and compared it with those in atopic dermatitis (AD) patients and healthy subjects. Fungal DNA was directly collected from the lesional and non-lesional skin of the trunk of 22 psoriasis patients by applying a transparent dressing. The extracted DNA was amplified by using specific primers designed for the PCR in the intergenic spacer or internal transcribed spacer area of the ribosomal RNA. All nine of the Malassezia species were detected at different rates from the 22 psoriasis patients. The overall detection rates in lesional and non-lesional skin of M. restricta, M. globosa and M. sympodialis were high (96%, 82% and 64%, respectively), whereas the detection rates of the other species were relatively low. However, there was no difference in the rates between lesional and non-lesional skin areas. The average number of Malassezia species detected in overall sites of the psoriasis patients was 3.7 +/- 1.6 species, although this fact showed no correlation with the severity of the symptoms. The number of Malassezia species detected was 4.1 +/- 1.9 in the AD patients, and 2.8 +/- 0.8 in the healthy subjects, suggesting that the skin microflora of psoriasis patients and AD patients show greater diversity than that of healthy subjects.     

Quantitative analysis of Malassezia in the scale of patients with psoriasis using a real-time polymerase chain reaction assay

BACKGROUND: It has been suggested that Malassezia is associated with the development of skin lesions in psoriasis because of the response of the scalp lesions in psoriasis to antifungal agents. Malassezia restricta and M. globosa are the two major members of the cutaneous Malassezia flora in patients with psoriasis, although they have not been analysed quantitatively. OBJECTIVES: This study quantified the two major cutaneous Malassezia species in psoriatic scale from different body sites using a real-time polymerase chain reaction (PCR) assay. METHODS: Scale samples were collected from lesional and nonlesional skin of 20 Japanese patients with psoriasis and fungal DNA was extracted from the samples directly. All the Malassezia species, including the two major species M. globosa and M. restricta, were quantified with high accuracy, using a real-time PCR assay. RESULTS: Colonization by M. restricta was approximately five times higher at all body sites than colonization by M. globosa. Malassezia colonization was significantly lower in patients with hyperlipidaemia than in patients with normolipidaemia. CONCLUSIONS: Malassezia restricta is the predominant species in psoriatic scale.     

Molecular analysis of Malassezia microflora in seborrheic dermatitis patients: comparison with other diseases and healthy subjects

Malassezia species colonize the skin of normal and various pathological conditions including pityriasis versicolor (PV), seborrhoeic dermatitis (SD) and atopic dermatitis (AD). To elucidate the pathogenic role of Malassezia species in SD, Malassezia microflora of 31 Japanese SD patients was analyzed using a PCR-based, culture-independent method. Nested PCR assay using the primers in the rRNA gene indicated that the major Malassezia species in SD were M. globosa and M. restricta, found in 93 and 74% of the patients, respectively. The detection rate and number of each species varied similarly in SD, PV and healthy subjects (HSs), whereas AD showed higher values. Real-time PCR assay showed that the lesional skin harbored approximately three times the population of genus Malassezia found in nonlesional skin (P<0.05), and that M. restricta is a significantly more common species than M. globosa in SD (P<0.005). Genotypic analysis of the rRNA gene showed that the M. globosa and M. restricta from SD patients fell into specific clusters, and could be distinguished from those collected from HSs, but not from those colleted from AD patients. Our results indicate that certain strains of M. restricta occur in the lesional skin of SD patients.     

Identification of Malassezia species isolated from scalp skin of patients with psoriasis and healthy subjects

The role of Malassezia species in psoriasis is still undetermined, but several reports have associated these lipophilic yeasts with the development of skin lesions in psoriasis. The aim of our study was to analyze the prevalence of Malassezia species in the scalp lesions of patients with psoriasis and assess the distribution of the species according to patient sex, age, and duration of the disease. Forty psoriatic patients with scalp involvement and the same number of clinically healthy individuals were included in the study. The samples were obtained by scraping the skin surface of the scalp of all subjects and then incubated on modified Dixon agar. The yeasts isolated were identified by their morphological and physiological properties according to Guillot et al method. M.globosa in its yeast phase was a predominant species (55%), followed by M.slooffiae (18%) and M.restricta (10%), the latter being the most common species isolated from healthy scalp skin. We found significant difference in the distribution of Malassezia species between psoriatic and healthy scalp skin and in the distribution of Malassezia species according to the severity of the scalp involvement.     

Cutaneous Malassezia flora in atopic dermatitis differs between adults and children

BACKGROUND: Malassezia species are suspected to be involved in the development of skin lesions in atopic dermatitis (AD) when the response of adult AD to anti-inflammatory treatments is poor. However, a comparative analysis of Malassezia flora between adults and children with AD has not been performed. OBJECTIVES: To compare the cutaneous Malassezia flora between adults and children with AD. METHODS: Scale samples were collected from skin lesions of 58 patients with AD in the head and neck regions (28 males and 30 females; 31 children and 27 adults), and fungal DNA was extracted from the samples directly. The number and identities of the Malassezia species were analysed with high accuracy using a polymerase chain reaction-based culture-independent method. The in vivo level of anti-Malassezia IgE antibody was also assayed. RESULTS: Malassezia restricta was the predominant species in the children with AD, while both M. restricta and M. globosa predominated in the adults. The adults showed increased sensitization in terms of anti-Malassezia-specific IgE responses in the sera to both M. globosa and M. restricta in comparison with the children. CONCLUSIONS: The cutaneous Malassezia flora differs significantly between the two age groups.     

Identification of Malassezia yeast species isolated from patients with pityriasis versicolor

Pityriasis versicolor (PV) is a disease with worldwide distribution. Twelve different species of Malassezia yeast have been described. The objective of this study was to determine which species of Malassezia are more prevalent in patients with pityriasis versicolor. Samples were collected by scraping the lesions of 87 patients with a clinical suspicion of pityriasis versicolor. The samples were then submitted to fungal microscopy and culture to identify the species. The species found were: Malassezia sympodialis (30%), Malassezia furfur (25.7%), Malassezia globosa (22.7%), Malassezia restricta (12.1%), Malassezia obtusa (7.6%) and Malassezia slooffiae (1.5%).     

Malassezia globosa as the causative agent of pityriasis versicolor

BACKGROUND: The taxonomic revision carried out in 1996 on the genus Malassezia, which now comprises seven different species, made necessary a re-evaluation of the data concerning the ecology and pathogenicity of these lipophilic yeasts. Very little has been published since then. OBJECTIVES: The aim of this work was to contribute to the knowledge of the aetiology of pityriasis versicolor (PV) with a mycological study made according to the new species. METHODS: Ninety-six patients with PV completed the study. In all of them, samples were taken from the lesions for direct microscopy with KOH+ Parker ink and culture. Samples were also taken from normal skin of the trunk and the forehead of the same patients for culture. Cultures were made in modified Dixon medium in Petri dishes, incubated at 31 degrees C and the isolates were identified by morphological and physiological characteristics. RESULTS: In the PV lesions, direct microscopy always showed the typical mixture of globose blastoconidia and pseudomycelium. Only one patient, having received previous topical antimycotic treatment, was negative. The spherical yeasts observed in vivo were morphologically identical to the globose yeasts characteristic of M. globosa. In culture, M. globosa was found in 97% of cases, alone in 60% of them and associated with M. sympodialis in 29% and M. slooffiae in 7%. These two species were also found in similar percentages on the clinically uninvolved skin of the trunk, whereas M. globosa was not isolated at these sites. However, on the forehead, a small number of colonies of M. globosa was recovered in 12% of cases. CONCLUSIONS: These results support the data previously reported and strongly suggest that M. globosa in its mycelial phase is the causative agent of PV.     

The prevalence of Malassezia yeasts in patients with atopic dermatitis, seborrhoeic dermatitis and healthy controls

Cultures for Malassezia yeasts were taken from both normal-looking skin and lesional skin in 124 patients with atopic dermatitis, 16 patients with seborrhoeic dermatitis and from normal skin of 31 healthy controls. Positive Malassezia growth was found in fewer patients with atopic dermatitis (56%) than in patients with seborrhoeic dermatitis (88%) or in healthy controls (84%, p<0.01). In the patients with atopic dermatitis, fewer positive cultures were found in lesional (28%) than in non-lesional skin (44%, p<0.05), while positive cultures were found in 75% of both lesional and non-lesional skin of patients with seborrhoeic dermatitis (not significant). M. sympodialis dominated in patients with atopic dermatitis (46%) and in healthy controls (69%). In patients with seborrhoeic dermatitis both M. sympodialis and M. obtusa were cultured in 43%. A Malassezia species extract mixture would increase the possibility of detecting IgE sensitization to Malassezia in patients with atopic dermatitis.     

Cutaneous Malassezia microbiota of healthy subjects differ by sex, body part and season

Malassezia is a component of normal cutaneous resident microbiota. The aim of this study was to quantitatively clarify the differences in cutaneous Malassezia microbiota in healthy subjects by sex, body part and season. Samples were collected from the forehead, cheek, upper chest and upper back of 20 healthy men and 20 healthy women (average age 32 years) in summer and winter by the swab method. Malassezia DNA was analyzed using a real-time PCR system. As a result, in sex, body parts and season, men, the upper trunk and summer showed the highest total numbers of cutaneous Malassezia species on average. There were also differences depending on the analytical method. The predominant species were M. restricta on the face of men, M. globosa and M. dermatis on the upper trunk of men, and M. globosa and M. sympodialis on the upper trunk of women. This study clarified that the cutaneous Malassezia microbiota of healthy subjects differed by sex, body part and season.