Denis Julie, Machouart Marie, Morio Florent, Sabou Marcela, Kauffmann-LaCroix Catherine, Contet-Audonneau Nelly, Candolfi Ermanno, Letscher-Bru Valérie
Laboratoire de Parasitologie et de Mycologie Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
Institut de Parasitologie et de Pathologie Tropicale, EA 7292, Fédération de Médecine Translationnelle, Université de Strasbourg, Strasbourg, France.
J Clin Microbiol. 2016 Dec 28;55(1):90-96. doi: 10.1128/JCM.01763-16. Print 2017 Jan.
The genus Malassezia comprises commensal yeasts on human skin. These yeasts are involved in superficial infections but are also isolated in deeper infections, such as fungemia, particularly in certain at-risk patients, such as neonates or patients with parenteral nutrition catheters. Very little is known about Malassezia epidemiology and virulence. This is due mainly to the difficulty of distinguishing species. Currently, species identification is based on morphological and biochemical characteristics. Only molecular biology techniques identify species with certainty, but they are time-consuming and expensive. The aim of this study was to develop and evaluate a matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) database for identifying Malassezia species by mass spectrometry. Eighty-five Malassezia isolates from patients in three French university hospitals were investigated. Each strain was identified by internal transcribed spacer sequencing. Forty-five strains of the six species Malassezia furfur, M. sympodialis, M. slooffiae, M. globosa, M. restricta, and M. pachydermatis allowed the creation of a MALDI-TOF database. Forty other strains were used to test this database. All strains were identified by our Malassezia database with log scores of >2.0, according to the manufacturer's criteria. Repeatability and reproducibility tests showed a coefficient of variation of the log score values of <10%. In conclusion, our new Malassezia database allows easy, fast, and reliable identification of Malassezia species. Implementation of this database will contribute to a better, more rapid identification of Malassezia species and will be helpful in gaining a better understanding of their epidemiology.
马拉色菌属包含人体皮肤上的共生酵母。这些酵母可引发浅表感染，但也可在深部感染（如真菌血症）中分离出来，尤其是在某些高危患者中，如新生儿或使用肠外营养导管的患者。关于马拉色菌的流行病学和毒力，人们了解甚少。这主要是由于区分物种存在困难。目前，物种鉴定基于形态学和生化特征。只有分子生物学技术能够确定物种，但它们耗时且昂贵。本研究的目的是开发并评估一种基质辅助激光解吸电离飞行时间（MALDI-TOF）数据库，用于通过质谱法鉴定马拉色菌属物种。对来自法国三家大学医院患者的85株马拉色菌分离株进行了研究。每株菌株通过内部转录间隔区测序进行鉴定。马拉色菌糠秕亚种、合轴马拉色菌、斯洛菲马拉色菌、球形马拉色菌、限制马拉色菌和厚皮马拉色菌这六个物种的45株菌株用于创建MALDI-TOF数据库。另外40株菌株用于测试该数据库。根据制造商的标准，我们的马拉色菌数据库对所有菌株的鉴定对数得分均>2.0。重复性和再现性测试显示对数得分值的变异系数<10%。总之，我们新的马拉色菌数据库能够轻松、快速且可靠地鉴定马拉色菌属物种。该数据库的应用将有助于更好、更快速地鉴定马拉色菌属物种，并有助于更好地了解其流行病学。
