Arantes Bruno B A, Cabral Ana Karla L F, Dos Santos Kelvin S, Mendonça Matheus B, Dos Santos Rafaela C, Bugalho Beatriz C M, Fernandes Lígia De S, Martinez Luis R, Fusco-Almeida Ana Marisa, Mendes-Giannini Maria José S
Department of Clinical Analysis, School of Pharmaceutical Sciences, São Paulo State University UNESP, Araraquara 14800-903, Brazil.
Laboratory of Medical Mycology, School of Pharmaceutical Sciences, Federal University of Amazonas-UFAM, Manaus 69077-000, Brazil.
J Fungi (Basel). 2025 Jun 14;11(6):455. doi: 10.3390/jof11060455.
Dermatophytosis is a fungal infection that affects the skin, hair, and nails, impacting approximately 25% of the global population. is a geophilic fungus that can cause infections in humans and animals. Several studies have been conducted regarding its virulence, or ability to cause disease. This species may produce keratinolytic enzymes and form biofilms, which can increase resistance to treatment. Thus, this study focuses on investigating the biofilm formation of isolated from canine dermatophytosis using an ex vivo hair model, its biofilm extracellular matrix macromolecular contents, and the expression of genes involved in the colonization of keratinized surfaces. The biofilm was analyzed for metabolic activity using the XTT reduction assay, crystal violet staining to measure biofilm biomass, scanning electron microscopy (SEM), and the presence of polysaccharides, proteins, and extracellular DNA in the biofilm extracellular matrix. The virulence genes subtilisin 7, fungalysin (extracellular metalloproteinase), and efflux pump (Multidrug and Toxin Extrusion Protein 2) were evaluated by qPCR, comparing the planktonic and biofilm phenotypes. formed a robust biofilm, which matured after 5 days. Scanning electron microscopy (SEM) revealed the presence of an extensive extracellular matrix. In the hair model, the characteristic ectothrix parasitism of the species is observable. The gene expression analysis revealed a higher expression of all evaluated genes in the biofilm form compared to the planktonic form. Thus, exhibits a biofilm characterized by a robust extracellular matrix and high gene expression of factors related to pathogenesis and resistance.
皮肤癣菌病是一种影响皮肤、毛发和指甲的真菌感染，全球约25%的人口受其影响。犬小孢子菌是一种嗜土真菌，可导致人类和动物感染。关于其毒力或致病能力已进行了多项研究。该菌种可能产生角质溶解酶并形成生物膜，这会增加对治疗的抵抗力。因此，本研究重点使用体外毛发模型研究从犬皮肤癣菌病中分离出的犬小孢子菌的生物膜形成、其生物膜细胞外基质大分子成分以及参与角质化表面定植的基因表达。使用XTT还原试验分析生物膜的代谢活性，用结晶紫染色测量生物膜生物量，进行扫描电子显微镜（SEM）检查，并检测生物膜细胞外基质中多糖、蛋白质和细胞外DNA的存在。通过qPCR评估毒力基因枯草杆菌蛋白酶7、真菌溶素（细胞外金属蛋白酶）和外排泵（多药和毒素外排蛋白2），比较浮游型和生物膜型的表型。犬小孢子菌形成了强大的生物膜，5天后成熟。扫描电子显微镜（SEM）显示存在广泛的细胞外基质。在毛发模型中，可以观察到该菌种典型的发外型寄生现象。基因表达分析显示，与浮游型相比，生物膜型中所有评估基因的表达均更高。因此，犬小孢子菌表现出一种以强大的细胞外基质以及与发病机制和抗性相关因子的高基因表达为特征的生物膜。
