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.     

Epidemiology of pityriasis versicolor in Adana, Turkey

Pityriasis versicolor is a common superficial mycoses of the skin. It is now recognized that the causative organisms of this infection are different species of Malassezia . The aim of this study was to determine the distribution of Malassezia species in patients with pityriasis versicolor in Adana, Turkey. In total, 97 patients positive for Malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. All samples were inoculated in plates containing modified Dixon's medium. However, only 44 of the patients (45.4%) showed Malassezia spp. in culture. Malassezia globosa (47.7%) was the most commonly isolated species followed by Malassezia furfur (36.4%) and Malassezia slooffiae (15.9%). Mixed Malassezia species were not isolated. In conclusion, M. globosa was found to be the predominant PV isolate in Adana, Turkey.     

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%).     

花斑糠疹和马拉色菌毛囊炎菌种分布特点分析

目的探讨花斑糠疹和马拉色菌毛囊炎的菌种分布特点。方法从临床诊断为花斑糠疹和马拉色菌毛囊炎的患者分离培养菌种,通过形态学和生理生化学方法鉴定菌种,并比较两组患者菌种分布情况。结果共收集花斑糠疹病例161例,培养阳性121株,其中合轴马拉色菌46株,糠秕马拉色菌13株,球形马拉色菌29株,钝性马拉色菌33株;马拉色菌毛囊炎135例,培养阳性114株,其中合轴马拉色菌52株,糠秕马拉色菌43株,球形马拉色菌13株,钝性马拉色菌6株。两种疾病菌种分布差异有显著性(P<0.005)。结论花斑糠疹和马拉色菌毛囊炎菌种分布存在差异,可能为两种疾病不同临床表现的原因之一,但结果尚需慎重解释,需要分子水平的进一步研究。     

花斑糠疹与马拉色菌毛囊炎相关危险因素和致病菌分析

目的 研究花斑糠疹和马拉色菌毛囊炎的相关危险因素和致病菌特点,并比较其差异。方法 收集我院临床花斑糠疹和马拉色菌毛囊炎患者,均以1：1设置病例对照组,调查发病相关因素,采用SPSS16.0软件进行单因素和多因素Logstic回归分析。培养阳性菌株采用形态学和生理生化学方法鉴定到菌种,比较菌种分布。结果 共收集到163例花斑糠疹和132马拉色菌毛囊炎患者。单因素回归分析显示与花斑糠疹发病相关的因素有多汗和油性皮肤,与马拉色菌毛囊炎发病相关的因素有男性、潮湿环境、多汗、油性皮肤、刺激性食物、甜腻食物。多因素回归分析显示花斑糠疹的危险因素有多汗和油性皮肤,马拉色菌毛囊炎的危险因素有多汗、油性皮肤、男性和甜腻性食物。两种疾病致病菌均以合轴马拉色菌为优势菌,但糠秕马拉色菌在毛囊炎中占较高比例。结论 多汗和油性皮肤是花斑糠疹和马拉色菌毛囊炎共同的危险因素,而男性、甜腻性食物为马拉色菌毛囊炎独有的危险因素,两种疾病致病分布也存在统计学差异。     

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.     

Skin colonization by Malassezia species in neonates: a prospective study and relationship with neonatal cephalic pustulosis

OBJECTIVES: To assess skin colonization by Malassezia species in full-term healthy newborns, to investigate factors associated with colonization, and to look at acnelike cephalic pustulosis associated with this carriage. DESIGN: Samples were obtained from neonates and their mothers 0 to 5 days after birth and again 3 weeks later. Clinical patterns of common acnelike pustulosis were reported as mild (<10 papulopustules), moderate (> or =10 papulopustules), or absent. Direct examination and culture of sample. Identification of yeasts was based on microscopic and physiologic criteria. SETTING: A maternity hospital and the pediatric dermatology unit of a university hospital. PARTICIPANTS: Consecutive series of 102 neonates and their mothers. MAIN OUTCOME MEASURES: Incidence of skin colonization and type of Malassezia species found in neonates and correlation with neonatal cephalic pustulosis (neonatal acne). RESULTS: At the first visit, 11 neonates and 36 mothers had cultures positive for Malassezia. Malassezia sympodialis and Malassezia globosa were preferentially cultured. At 3 weeks, 29 (52%) of 56 neonates and 18 (32%) of 56 mothers had cultures positive for only M sympodialis and M globosa. Breastfeeding was not associated with a higher prevalence of Malassezia carriage in neonates. Malassezia colonization was higher when pustulosis was more severe and M sympodialis was found in pustules. CONCLUSIONS: Malassezia colonization begins at birth and increases in the first weeks of life. A high prevalence of M sympodialis in neonates is noted from birth. Its association with neonatal acne is confirmed. Further investigation is needed to study the role of sebum secretion rate and quality in the neonatal period.     

Antigenic components of Malassezia species for immunoglobulin E antibodies in sera of patients with atopic dermatitis

Antigenic components of Malassezia furfur, M. globosa, M. restricta, M. slooffiae, and M. sympodialis were studied for immunoglobulin E antibodies in sera of patients with atopic dermatitis (AD). Antigenic components were extracted from Malassezia cells by treatment with beta-mercaptoethanol, referred to as 2-ME extract. CBB staining and lectin blots using Con A, LCA, PHA-E4, PNA or RCA120 showed that the 2-ME extracts contained several species-dependent components that differed quantitatively and qualitatively among the Malassezia species at the protein level. In the Western blot with the 2-ME extracts, of 54 sera of the patients with AD (54 patients), the patients' IgE antibodies most frequently recognized components showing molecular weights of 43-46 kDa for M. slooffiae, 12-22 kDa for M. sympodialis, 35-40 kDa for M. restricta, 45-50 kDa for M. globosa, and of 67-72 kDa for M. furfur, respectively. In the correlative study, in which the total band intensities generated for each extract in Western blot were compared among the Malassezia species, the intensity for M. globosa was well correlated with that for M. sympodialis (r=0.756). In the Western blot inhibition test, the 2-ME extract of M. globosa partially inhibited the reaction of the antigenic components of other Malassezia species with the patient's IgE antibodies. These results indicated that Malassezia species contained both species-specific and common antigenic components at the IgE antibody level.     

从花斑癣患者的皮损区及非皮损区分离和鉴定马拉色菌

目的 研究花斑癣患者皮损区及非皮损区马拉色菌菌种构成;不同解剖部位、皮损颜色及各菌种的分布情况;患者病情和年龄与菌种构成的关系。方法 用无菌胶带粘取113例花斑癣患者皮损区及非皮损区共629个部位的皮屑,分别接种于含菜子油培养基中分离马拉色菌,用生理生化及形态学方法鉴定菌种。结果 皮损区与相对应的非皮损区马拉色菌分离阳性率无差别,非皮损区额部和胸背部分离阳性率高于上、下肢。共分离到565株马拉色菌,鉴定出合轴马拉色菌(44.78%)、糠秕马拉色菌(32.94%)、球形马拉色菌(11.68%)、钝形马拉色菌(5.84%)及限制马拉色菌(4.76%)共5个种,有27处(5.01%)同时分离到两种菌。皮损区与非皮损区菌种构成无明显差别,限制马拉色菌主要从额部分离出。菌种构成与皮损面积无关,但与皮损颜色和患者年龄有关。皮损颜色与病程无关。结论 花斑癣患者皮损区与非皮损区马拉色菌分离阳性率和菌种构成基本一致,与病情无关,而不同解剖部位、皮损类型及年龄患者的菌种构成有一定差异。     

Effects of topical vehicles on growth of the lipophilic Malassezia species

In the present study, the abilities of major Malassezia species, M. sympodialis, M. globosa and M. furfur, to assimilate topical agents, which have been widely used as a material of ointment for skin diseases, were tested. Obvious growth of M. furfur on GYEP agar plate was noted in the presence of white petrolatum, purified white petrolatum, hydrophilic ointment and heparinoid in hydrophilic ointment, and also M. sympodialis showed similar growth when they were cultured with hydrophilic or heparinoid in hydrophilic ointment. In contrast, M. globosa did not grow on GYEP in the presence of the any topical agents tested. These results suggest that Malassezia species, especially M. furfur and M. sympodialis, assimilate several topical agents and showed the drug-depended cell growth.     

IgE antibodies to Malassezia furfur, M. sympodialis and Pityrosporum orbiculare in patients with atopic dermatitis, seborrheic eczema or pityriasis versicolor, and identification of respective allergens

Malassezia yeasts may be a trigger factor for atopic dermatitis. Following the recent reclassification of the genus, the presence of specific IgE antibodies was examined in the sera of patients with atopic dermatitis (n = 223), pityriasis versicolor (n = 83), seborrheic eczema (n = 50) and hymenoptera allergy (n = 39) and in controls without skin diseases (n = 50). In addition to using the commercially available radioallergosorbent test (RAST) for Pityrosporum orbiculare couplings were also made against the reference strains for M. furfur and M. sympodialis. To characterize the specificity and molecular weight of corresponding epitopes identical material was used for production of an immunoblot. Despite high total levels of IgE, controls and patients with pityriasis versicolor showed no specific IgE antibodies. Six patients (12%) with seborrheic eczema were positive while 78 patients (35%) with atopic dermatitis had specific IgE antibodies in higher RAST classes that differed between the Malassezia species. The molecular weights of the main antigens of M. sympodialis and M. furfur were determined to be 15, 22, 30, 37, 40, 58, 79, 92, 99 and 124 kDa and 15, 25, 27, 43, 58, 92, 99 and 107 kDa, respectively. Evaluated according to the location of their disease, patients with head and neck lesions most frequently showed Malassezia-specific IgE antibodies. However, there were differences between the Malassezia species tested, the previously used strain P. orbiculare being assignable to the species M. sympodialis.     

In vitro susceptibility of the seven Malassezia species to ketoconazole, voriconazole, itraconazole and terbinafine

Fifty-five strains, either authentic or ex-type, of seven Malassezia species were investigated for in vitro susceptibility to various concentrations (0.03-64.0 microg/mL) of three azole drugs, ketoconazole, voriconazole and itraconazole, as well as the allylamine terbinafine, using the agar dilution method. All strains of the seven Malassezia species were susceptible to the three azole drugs at low concentrations. M. furfur, M. sympodialis, M. slooffiae, M. pachydermatis, M. globosa, M. obtusa and M. restricta were most sensitive to ketoconazole and itraconazole, with minimum inhibitory concentrations (MICs) ranging from < or = 0.03 to 0.125 microg/mL. The recently introduced antifungal, voriconazole, was also very effective, with MIC80 values < or = 0.03 microg/mL for 80% of strains. MICs of terbinafine against the seven Malassezia species ranged from 相似文献   

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。     

南通和南京马拉色菌毛囊炎临床调查及致病菌种分析

目的 探讨南通和南京马拉色菌毛囊炎的易感因素及致病菌种在不同地区、不同部位马拉色菌毛囊炎中的菌种分布情况。方法 对符合病例收集纳入标准的患者进行问卷调查,取毛囊内容物进行真菌涂片、培养;并根据形态学和生理生化特征进行菌种鉴定。结果 241例临床诊断为马拉色菌毛囊炎的患者,真菌涂片204例阳性,涂片阳性率84.65%;收集标本259份,共得阳性株213株,其中马拉色菌209株,念珠菌4株（占1.54%）,真菌培养阳性率82.24%。菌种鉴定：209株马拉色菌活化菌种后,可供鉴定的马拉色菌菌株186株,共检测到6个菌种的马拉色菌,其中糠秕马拉色菌111株（59.68%）、斯洛菲马拉色菌43株（23.12%）、合轴马拉色菌17株（9.14%）、球形马拉色菌9株（4.84%）、厚皮马拉色菌4株（2.15%）、钝形马拉色菌2株（1.08%）。不同个体、不同部位的菌种分布：胸部、后背、腹部和面颈部以糠秕马拉色菌为主,上肢、肩部和头顶以斯洛菲马拉色菌为主,下肢均为球形马拉色菌。同一个体、不同发病部位存在不同的菌种,主要为糠秕马拉色菌合并合轴或斯洛菲马拉色菌。 结论 南通和南京马拉色菌毛囊炎存在6种马拉色菌致病菌种,糠秕和斯洛菲马拉色菌是主要的致病菌种。     

从夫妻双方的头皮屑中分离和鉴定马拉色菌

目的 探讨夫妻双方的头皮屑中马拉色菌的带菌情况，菌种构成及夫妻间共用梳子与马拉色菌菌种一致性的关系，方法 采用Leeming和Notman培养基，Dixon培养基和含菜子油培养基分别同时培养114对夫妻的头皮屑，观察培养阳性率与头皮屑严重程度的关系。根据生理生化学及形态学特点鉴定菌种，并比较在这3种培养基中菌落初长时间及对菌种有无选择性。结果 从114对夫妻（共228人0中153人的头皮屑中分离到马拉色菌，阳性率为67.11%。培养阳性率与头皮屑的严重程度有正相关关系，3种培养基共分离到马拉色菌，阳性率为67.11%。培养阳性率与头皮屑的严重程度有正相关关系。3种培养基共分离到459株马拉色菌，从中鉴定出合轴马拉色菌（33.33%)，球形马拉色菌（25.05%)，限制马拉色菌（15.47%)，糠秕马拉色菌（13.73%)和钝形马拉色菌（12.42%)共5个种，3种培养基对菌种无选择性，但在含菜子油的培养基中菌落初长时间最短，同一头皮屑在3种培养基上分离到同一菌种有129人（56.58%)，分离到2种菌的有24人（10.53%)，共用梳子的夫妻双方的头皮屑中菌种相同者（35.96%)显著多于菌种不同者（13.16%)；夫妻间共用梳子者头皮屑中菌种相同者（50.67%)显著多于非共用梳子者（7.69%)。结论 头皮屑中的优势菌种主要为合轴和球形马拉色菌，夫妻双方的头皮屑中马拉色菌菌种一致率较高，而夫妻间共用梳子组的菌种一致率更高，提示马拉色菌可在夫妻之间传播，共用梳子可能是重要的传播媒介。     

Differentiation of Malassezia species: selectivity of Cremophor EL, castor oil and ricinoleic acid for M. furfur

In recent years, the genus Malassezia has been reclassified based on molecular data. In addition to M. furfur , M. pachydermatis and M. sympodialis , four new species, M. globosa , M. obtusa , M. restricta and M. slooffiiae , have been described. However, apart from their lipid dependence, little is known about the metabolism and nutritional requirements of all the seven species. Further to recent studies, 10 hydrophilic emulsifiers (HLB > 10) were examined in an agar diffusion test to determine their growth-promoting effect on reference strains of the different Malassezia species. Polyethylene glycol (PEG) 7 glyceryl monoalcanoate (Cetiol HE), PEG–glyceryl stearate (Tagat S2) and macrogol-50 stearate (Myrj 53) were metabolized by all strains, while PEG-35 castor oil (Cremophor EL) was metabolized only by M. furfur . The latter observation is due to a different metabolism of castor oil and its main component, ricinoleic acid (12-hydroxy oleic acid), which may also give an insight into the pathogenesis of diseases that are associated with Malassezia spp. As hydroxy fatty acids are important in maintaining the epidermal structure and function, their metabolism specifically by M. furfur might clarify some clinical aspects of pityriasis versicolor. Apart from this speculation, use of Cremophor EL, with splitting of esculin as an additional key character, improves the distinction of the species M. furfur , M. slooffiae and M. sympodialis .     

Prevalence of pityriasis versicolor in a group of Italian pregnant women

BACKGROUND: Although a predisposing role of pregnancy to Malassezia infections is referred, data on the prevalence of pityriasis versicolor (PV) in pregnant women are not available in literature. OBJECTIVE: To investigate the frequency of PV during pregnancy, 60 pregnant women were clinically and microscopically investigated during and after pregnancy. RESULTS: Fifty-two women completed all visits; three women were affected by PV at first or third trimester of pregnancy, and none at 6 months after delivery. Colonization due to Malassezia yeasts was very significantly (P < 0.01) or significantly increased (P < 0.05) at the third trimester and 6 months after delivery, respectively. No variation was observed between the end of pregnancy and the postpartum (P > 0.05). CONCLUSION: Frequency of PV during pregnancy (5.7%) does not seem different from that reported in general population living in temperate climates (2-5%). However, higher degree of colonization by Malassezia resulted at the end of pregnancy and postpartum.     

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.     

Hyperkeratotic head and neck Malassezia dermatosis

BACKGROUND: Pityriasis versicolor (tinea versicolor) is a common skin disorder due to Malassezia usually affecting adolescents and young adults, more frequently in the tropics. Facial involvement, isolated or not, is not frequent in white adults. OBJECTIVE: Here, we report a possible atypical hyperkeratotic form of dermatosis of the face, in two young immunocompetent Caucasian patients, particularly recalcitrant to therapy. RESULTS: Skin scrapings grew yeasts belonging to the genus Malassezia, including both M. globosa and M. sympodialis. This unusual variant needs long-term therapy with systemic and topical imidazoles together with facial cleansing. CONCLUSION: We propose the name hyperkeratotic head and neck Malassezia dermatosis for this distinctive clinical entity. This variant of pityriasis versicolor should be considered in the differential diagnosis of seborrheic dermatitis and dermatitis neglecta.     

花斑糠疹和马拉色菌毛囊炎致病菌菌种分析

目的使用限制性内切酶方法鉴定临床花斑糠疹和马拉色菌毛囊炎致病菌菌种分布并比较其差异。方法收集临床花斑糠疹和马拉色菌毛囊炎标本,植于Leeming-Notman培养基。培养阳性菌株提取DNA,扩增其26srDNA片段,用CfoⅠ酶和BstF51酶切。结果共鉴定花斑糠疹阳性菌株128份,其中糠秕马拉色菌49份,合轴马拉色菌23份,球形马拉色菌26份,钝性马拉色菌6份,M.japponica 1份,斯洛菲马拉色菌1份,混合感染标本22份。共鉴定马拉色菌毛囊炎阳性标本70份,其中糠秕马拉色菌43株,合轴马拉色菌5株,球形马拉色菌9株,钝性马拉色菌1株,混合感染标本12份。两种疾病菌种分布差异存在统计学意义(P=0.009)。结论花斑糠疹和马拉色菌毛囊炎致病菌菌种存在一定差异。限制性酶切方法为一种准确、快速的马拉色菌菌种鉴定方法。