Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Mycoses. 2023 Jun;66(6):540-549. doi: 10.1111/myc.13580. Epub 2023 Mar 7.
Malassezia furfur is a member of the human skin microbiomes that can cause various skin diseases. Dimorphism plays a role as the yeast phase predominates during skin colonisation whereas mycelial forms are observed in the scales of patients with pityriasis versicolor (PV). However, due to their condition-dependence for growth, it is difficult to culture M. furfur and this is an additional challenge for studying the pathogenicity of this fungus.
To describe different media suitable for culturing Malassezia from the yeast phase into mycelial forms, with a particular focus on nutritional supplements and pH conditions.
Clinical M. furfur isolates from patients with PV and healthy individuals were used to investigate Malassezia dimorphism as well as the activity and expression of lipase enzymes.
Our experimental media were significantly more likely to promote mycelial growth in strains from healthy individuals compared to those from patients with PV. Lipase activity was increased in the mycelial phase cells compared to yeast forms for all strains tested. Assessment of the relative transcriptional expression of lipase within M. furfur revealed that LIP-coding genes were upregulated in mycelium relative to yeast forms for the strains tested. However, the increases in LIP3, LIP5 and LIP6 gene expressions were significantly greater in strains from healthy individuals compared to those from patients with PV.
Overall, this study validated effective growth conditions to study M. furfur virulence factors and demonstrated that lipase is associated with M. furfur dimorphism.
糠秕马拉色菌是人类皮肤微生物组的一员，可引起各种皮肤疾病。形态发生在皮肤定植时以酵母相为主，而在花斑癣（PV）患者的鳞屑中则观察到菌丝形式时起着作用。然而，由于其生长条件依赖性，很难培养糠秕马拉色菌，这给研究该真菌的致病性增加了额外的挑战。
描述适合从酵母相培养到菌丝相的不同培养基，特别关注营养补充剂和 pH 值条件。
使用来自 PV 患者和健康个体的临床糠秕马拉色菌分离物来研究马拉色菌的二态性以及脂肪酶酶的活性和表达。
与来自 PV 患者的菌株相比，我们的实验培养基更有可能促进来自健康个体的菌株的菌丝生长。与酵母形式相比，所有测试菌株的菌丝相细胞中的脂肪酶活性增加。对糠秕马拉色菌中脂肪酶相对转录表达的评估表明，在所测试的菌株中，LIP 编码基因在菌丝体中相对于酵母形式上调。然而，与来自 PV 患者的菌株相比，来自健康个体的菌株中 LIP3、LIP5 和 LIP6 基因表达的增加显著更大。
总的来说，这项研究验证了研究糠秕马拉色菌毒力因子的有效生长条件，并表明脂肪酶与糠秕马拉色菌的二态性有关。
