Angiolella Letizia, Leone Claudia, Rojas Florencia, Mussin Javier, de Los Angeles Sosa María, Giusiano Gustavo
Department of Public Health and Infectious Diseases. University of Rome "Sapienza", Italy. Piazzale Aldo Moro 5, 00100 Roma, Italy.
Departamento de Micología, Instituto de Medicina Regional, Universidad Nacional del Nordeste, Resistencia, Argentina.
Med Mycol. 2018 Jan 1;56(1):110-116. doi: 10.1093/mmy/myx014.
Malassezia species are natural inhabitants of the healthy skin. However, under certain conditions, they may cause or exacerbate several skin diseases. The ability of this fungus to colonize or infect is determined by complex interactions between the fungal cell and its virulence factors. This study aims to evaluate "in vitro" the hydrophobicity levels, the adherence on a plastic surface and the biofilm formation of 16 clinical isolates of Malassezia furfur. Cellular surface hydrophobicity (CSH) levels were determined by two-phase system. The biofilm formation was determined by tetrazolium salt (XTT) reduction assay and by Scanning Electron Microscopy (SEM). Results showed many isolates were hydrophobic, adherent, and producers of biofilm on abiotic surfaces with different capacity. SEM observations confirmed an abundant extracellular matrix after 48 h of biofilm formation. About 63% of strains with high production of biofilm showed medium to high percentage of hydrophobicity and/or adherence. In addition, it has been demonstrated a correlation between hydrophobicity, adherence, and biofilm formation in about 60% of strains examined. These important virulence factors could be responsible of this yeast changing from a commensal to a pathogenic status.
马拉色菌属是健康皮肤的天然寄居菌。然而，在某些条件下，它们可能引发或加剧多种皮肤疾病。这种真菌的定植或感染能力由真菌细胞与其毒力因子之间的复杂相互作用决定。本研究旨在“体外”评估16株糠秕马拉色菌临床分离株的疏水性水平、在塑料表面的黏附情况以及生物膜形成情况。通过两相系统测定细胞表面疏水性（CSH）水平。通过四氮唑盐（XTT）还原试验和扫描电子显微镜（SEM）测定生物膜形成情况。结果显示，许多分离株具有疏水性、黏附性，并且在非生物表面形成生物膜的能力各不相同。SEM观察证实，生物膜形成48小时后有丰富的细胞外基质。约63%生物膜高产菌株表现出中等到高比例的疏水性和/或黏附性。此外，在约60%检测菌株中已证明疏水性、黏附性和生物膜形成之间存在相关性。这些重要的毒力因子可能是这种酵母菌从共生状态转变为致病状态的原因。
