马拉色菌相关人群及正常人群耳耵聍中马拉色菌带菌情况的调查

目的调查马拉色菌相关人群及正常人群耳耵聍中马拉色菌带菌情况。方法用结晶紫染色法对96例被调查人群耳耵聍进行马拉色菌检测,同时作培养,并以标准株作对照,用生理生化方法将耵聍中分离到的79株马拉色菌进行分类。结果马拉色菌相关人群耳耵聍中马拉色菌的直接检出率为91．84％（45／49）,培养阳性率为81．63％（40／49）,其中厚皮马拉色菌8株（16．33％）,合轴马拉色菌10株（20．41％）,糠秕马拉色菌22株（44．90％）。正常人群耳耵聍马拉色菌直接检出率为89．36％（42／47）,培养阳性率为78．72％（37／47）,其中厚皮马拉色菌5株（10．64％）,合轴马拉色菌8株（17．02％）,糠秕马拉色菌23株（48．93％）,斯洛菲马拉色菌1株（2．13％）。结论马拉色菌为正常人群及马拉色菌相关人群外耳道正常菌群,两组人群中马拉色菌的分离率和菌种分布无显著性差异。     

正常人耵聍中马拉色菌菌种构成研究

目的研究正常人耵聍中马拉色菌菌种构成及同一宿主耵聍中菌种是否一致。方法采集45名健康志愿者双侧耵聍,0.1%曲拉通X-100溶解稀释后接种于含菜籽油培养基,生化及形态学方法鉴定到种,同时提取菌种DNA,用真菌通用引物ITS1/ITS4做PCR扩增并测序鉴定。结果有44例(97.78%)双侧耵聍中均培养出马拉色菌(共分离出88株菌),菌种构成:糠粃马拉色菌29株(32.95%)、斯洛菲马拉色菌23株(26.14%)、合轴马拉色菌18株(20.45%)、球形马拉色菌11株(12.50%)、限制性马拉色菌7株(7.95%)。44例(88株菌)中双侧耵聍菌种相同者有38例(76株菌)(一致率86.36%)。结论正常人耵聍中马拉色菌菌种分布较广,主要菌种为糠秕马拉色菌。同一宿主双侧耵聍中马拉色菌菌种具有一定的一致性。     

南海海军部队特发性瘙痒症患者皮肤马拉色菌定植调查

目的研究南海海军部队特发性皮肤瘙痒症患者皮肤马拉色菌的检出以及菌种的构成,探讨马拉色菌与特发性瘙痒症之间的相关性。方法对采自56例特发性瘙痒症患者与50例健康者的鳞屑标本进行真菌学镜检及采用菜子油培养基培养,根据菌落形态和生理生化特点进行菌种鉴定。结果观察组与对照组镜检阳性率分别为74．10％和72．00％,X2=0．344,P〉0．05两者比较无统计学意义。而镜检马拉色菌孢子密度Ⅲ级以上（每10个高倍视野≥50个者）,观察组与对照组分别为74．70％和38．89％,X2=20．30,P〈0．01。两者统计学比较差异有显著性意义。观察组168份标本共分离出143株马拉色菌,阳性率85．12％。其中合轴马拉色菌97株（67．83％）,球形马拉色菌26株（18．18％）,糠秕马拉色菌19株（13．29％）,钝形马拉色菌1株（0．70％）。对照组分离出马拉色菌107株,阳性率71．33％;其中糠秕马拉色菌55株（51．40％）,合轴马拉色菌33株（30．84％）,球形马拉色菌14株（13．08％）,钝形马拉色菌5株（4．67％）。菌种检出率和菌种构成差异均有显著性（X2=2．99,P〈0．01和7。X2=51.16,P〈0．01）。结论南海海军部队特发性瘙痒症患者皮肤马拉色菌载量较正常人高,其优势菌是合轴马拉色菌。     

江西地区花斑癣患者马拉色菌菌种分析

目的了解江西地区花斑癣患者马拉色菌菌种分布情况。比较传统吐温试验和改良吐温试验。方法对141例临床典型、真菌镜检阳性的花斑癣患者,采用Leeming和Notman培养基培养皮屑。以标准菌株为对照,按形态学和生理生化特点进行分类,分析马拉色菌菌种构成情况。同时比较传统吐温试验和改良吐温试验优缺点。结果培养到95株马拉色菌,分离出5个菌种:合轴马拉色菌62株,糠秕马拉色菌17株,球形马拉色菌9株,钝形马拉色菌6株,限制马拉色菌1株。结论合轴马拉色菌占有明显优势(65.26%)。改良吐温试验易于操作、费时短,尤其适合多标本的流行病学调查研究,值得推广。     

头颈部特应性皮炎患者面部马拉色菌的菌种分布

目的探讨马拉色菌(Malassezia)在头颈部特应性皮炎(atopic dermatitis, AD)患者中面部菌种分布以及与严重程度之间的关系。方法 2020年9月—12月共招募45例AD患者和50名健康志愿者,无菌棉签对患者和志愿者面部皮损区和非皮损区分别进行皮肤鳞屑取样,用荧光实时定量PCR的方法检测两组人群的7种马拉色菌的拷贝数,进行菌种分布以及数量的横断面分析。结果头颈部AD患者面部皮损区限制马拉色菌和球形马拉色菌的拷贝数分别为健康志愿者的3.13倍(P0.05)和6.69倍(P0.05),两者皆与患者AD病情严重度相关(P0.05)。结论头颈部AD患者面部皮损区限制马拉色菌和球形马拉色菌含量均高于健康人,两者含量均与AD患者病情严重程度相关。     

8种中药单体抗球形马拉色菌的体外药敏实验

目的观察8种中药单体对球形马拉色菌的体外抑菌效果。方法参照美国临床和实验室标准化研究所(CLSI)制订的M27-A方案中酵母菌微量稀释法,测定各中药单体体外抗球形马拉色菌的敏感性。结果 8种中药单体中,苦参碱、氧化苦参碱、麝香草酚、丁香酚有较强的抗马拉色菌作用(M IC<0.98～1.96μg/mL)。结论苦参碱、氧化苦参碱、麝香草酚、丁香酚有较强的抗马拉色菌作用,CLSI-M27A方案可用于抗马拉色菌敏感性测定。     

马拉色菌相关病例的探讨

目的探讨马拉色菌与相关皮肤病的特殊临床症状,提高对其的认识及疗效。方法回顾性分析相关病例的特殊临床表现、真菌学检查及治疗。结果3例临床表现为鳞屑性红斑患者的皮损中发现大量马拉色菌菌丝,经在含脂质的培养基上生长出球形马拉色菌,抗真菌治疗有效。1例表现为甲营养不良的患者甲屑中发现有大量马拉色菌菌丝。结论在非花斑癣患者的皮损中发现大量马拉色菌,可能与其外用皮质类固醇激素制剂有关。     

47766例拟诊皮肤真菌病患者病原菌分离培养结果分析

目的了解本院门诊拟诊皮肤真菌病患者真菌感染状况,掌握近期本地区皮肤真菌感染菌种分布结构。方法采用KOH直接涂片或染色显微镜观察与分离培养相结合的方法,对分离的菌落进行形态学鉴定,对真菌镜检和培养鉴定结果进行统计分析。结果 47 766例拟诊皮肤真菌病患者中,直接镜检和(或)培养阳性25 078例,占52.50%。其中皮肤癣菌病9 310例(48.94%)、马拉色菌感染8 938例(46.99%)、念珠菌及其他酵母菌感染603例(3.17%)。除外马拉色菌镜检和(或)培养阳性,其余38 839例镜检阳性率40.33%、分离培养阳性率25.99%。分离培养与镜检阳性符合率61.41%。皮肤癣菌菌种结构方面,红色毛癣菌为优势菌种占88.19%。结论皮肤癣菌病位居皮肤真菌病之首,以红色毛癣菌为优势菌,念珠菌及其他酵母菌感染亦值得关注。     

毛木耳白色突变体的遗传规律及分子标记开发

2016年秋季,漳州一农户种植的褐色毛木耳Auricularia cornea品种“43012H”发生白色突变,有的菌袋同时长出褐色、白色、褐色与白色交杂的颜色嵌合体耳片,有的菌袋长出白色耳片,而有的菌袋出菇颜色正常。采集白色耳片、褐色耳片和嵌合体耳片进行组织分离,得到的菌种进行栽培试验,从褐色耳片（正常）分离获得的菌种（AC_B）,种植得到正常的毛木耳子实体;从白色耳片（突变）分离获得的菌种（AC_W）,种植得到纯白色子实体;从颜色嵌合体耳片分离获得的菌种（AC_R）,栽培后也只长白色子实体,没有出现嵌合体子实体。AC_B分别与AC_W、AC_R的菌种混合接种栽培,菌袋中同时长出白色、褐色和嵌合体耳片。再次进行组织分离与栽培试验,性状稳定。对AC_B和AC_W进行基因组测序,获得2个与本研究中所用菌株的耳片颜色相关的SNP位点,即SNP1和SNP2。上述组织分离得到的菌株中,褐色菌株的基因型为SNP1 A/G（杂合）、SNP2 A（纯合）,白色菌株的基因型为SNP1 G（纯合）、SNP2 A/C（杂合）。     

糠秕马拉色菌药敏试验新方法的探讨

目的 建立一种新的糠秕马拉色菌药敏试验方法.方法 在ATBF2半固体培养基中添加不同种类和含量的脂质,用ATB Fungus 3药敏板条对ATCC14521和临床分离的糠秕马拉色菌进行了MIC测试.结果 孵育时间为72 h时对照孔中糠秕马拉色菌生长充分,吐温40浓度为1％时糠秕马拉色菌生长充分,且对药敏结果的影响最小.脂质的种类和含量对实验结果有影响.结论 用改良ATB Fungus 3药敏试验方法对糠秕马拉色菌进行抗真菌药敏试验,方法操作简便、结果易观察、试验结果重复性好.临床分离菌株与糠秕马拉色菌ATCC14521在ATB Fungus 3对照孔中的生长状况相同,结果易于判断.     

Concordance between phenotypical features and PCR-REA for the identification of Malassezia spp

The genus Malassezia has been recently revised and nowadays includes 11 species that cannot always be differentiated from each other by physiological and morphological tests. This study was aimed to evaluate the correlation between a molecular method and conventional phenotypic features in the identification of Malassezia spp. To achieve this aim, 92 Argentinean clinical strains isolated between 2001 and 2005 were analyzed along with three reference strains (Malassezia furfur CBS 7019, Malassezia sympodialis CBS 7222 and Malassezia slooffiae CBS 7956). By using PCR and restriction enzyme analysis with three different DNA endonucleases (PCR-REA), the molecular method consistently identified all three reference strains and all 92 clinical isolates as follows: 63 M. sympodialis, 18 M. furfur, 10 Malassezia globosa and one Malassezia obtusa. Phenotypic studies undentified 85 clinical isolates and two of the reference strains (total agreement > 91%). In particular for M. sympodialis, M. furfur and M. globosa, the species more frequently involved in human pathology, the agreement ranged between 84 and 96%. This result suggests that phenotypic studies are suitable for the presumptive identification of important Malassezia species in the clinical medical mycology laboratories where molecular methodologies are not available.     

Species of Malassezia associated with various dermatoses and healthy skin in the Mexican population

At the present, eight Malassezia species have been described and their distribution in normal skin and in several skin diseases appears variable. The aim of the present study was to determine the frequency and distribution of Malassezia species in patients with psoriasis, seborrhoeic dermatitis and pityriasis versicolor attended in a Hospital from Mexico City, in addition to a healthy individual group. Scales of abnormal and healthy skin were grown in modified Dixon agar and the species identification was performed by macroscopic and microscopic features; by catalase and urease reaction; growth at 32, 37 and 40 degrees C; and Tween 20, 40, 60 and 80 assimilation. The cultures from 63 persons were included: forty six patients (20 psoriasis, 15 seborrhoeic dermatitis, 11 pityriasis versicolor) and 17 healthy individuals (external auditory canal). A total of 96 isolates were obtained. The more frequently isolated species were: M. sympodialis (38.2%) and M. furfur (26.5%) in psoriasis; M. sympodialis (38.5%) and M. slooffiae (34.6%) in seborrhoeic dermatitis; M. globosa (46.7%) and M. sympodialis (26.7%) in pityriasis versicolor; and M. restricta (47.6%) and M. globosa (23.8%) in normal skin. The number of isolates, the species diversity and association were higher in the patients group than in the healthy individuals group.     

Pathological and clinical aspects of the diseases caused by Malassezia species

From veterinary point of view Malassezia pachydermatis has the greatest significance. It has been standing in the focus of interest since the early 1990s, mostly because of the frequency of otitis externa and dermatitis caused by this yeast in dogs. This is the only lipid-independent species in the genus Malassezia. It can be found in very large proportion on the skin of healthy animals, but can be isolated in much greater number from diseased dogs. It often causes illness together with other pathogens (e.g. Staphylococcus intermedius). Some breeds are predisposed. In addition to the treatment of the accidental concurrent diseases, therapy consists of systemic and/or topical antimicrobial treatment. Ketoconazole is used most frequently. Malassezia pachydermatis plays also a role in the skin disorders of other carnivores. It has little zoonotic potential, it can be dangerous to immunocompromised humans. The other Malassezia species have little veterinary importance, although M. sympodialis and M. globosa were isolated from asymptomatic animals (mostly cats) and from mixed infections.     

Taxonomy of Malassezia furfur: state of the art

Malassezia furfur is a lipophilic yeast considered as a normal component of the human skin flora. Apart from pityriasis versicolor, M. furfur has been linked to several skin diseases such as seborrheic dermatitis, folliculitis or atopic dermatitis. Moreover, these yeasts have been reported as agent of invasive human diseases including pneumonia, catheter-associated sepsis and peritonitis. The existence of morphological, serological, metabolical, biochemical and karyotipical differences has been described among isolates of these yeasts. These observations gave arguments for a possible intraspecific division, and this hypothesis has been confirmed by the existence of six species within the formerly called M. furfur (lipid-dependent Malassezia strains): M. furfur, Malassezia sympodialis, Malassezia globosa, Malassezia obtusa, Malassezia restricta and Malassezia slooffiae.     

Genotype analysis of Malassezia restricta as the major cutaneous flora in patients with atopic dermatitis and healthy subjects

Lipophilic yeasts of the genus Malassezia colonize the skin surface of humans and are an exacerbating factor in atopic dermatitis (AD). Two species, M. restricta and M. globosa are major cutaneous microflora in both AD patients and healthy subjects. We compared the DNA sequences of the intergenic spacer (IGS) region, located between the 26S and 5S rRNA genes of M. restricta colonizing the skin surfaces of 13 AD patients and 12 healthy subjects, and of three CBS stock strains as references. The IGS 1 sequences were divided into two major groups, corresponding to AD patients and healthy subjects. These findings suggest that a specific genotype of M. restricta plays a significant role in AD, although M. restricta commonly colonizes both AD patients and healthy subjects.