Background: The Malassezia yeasts which belong to the physiological microflora of human skin have also been\r\nimplicated in several dermatological disorders, including pityriasis versicolor (PV), atopic dermatitis (AD), and\r\npsoriasis (PS). The Malassezia genus has repeatedly been revised and it now accommodates 14 species, all but one\r\nbeing lipid-dependent species. The traditional, phenotype-based identification schemes of Malassezia species are\r\nfraught with interpretative ambiguities and inconsistencies, and are thus increasingly being supplemented or\r\nreplaced by DNA typing methods. The aim of this study was to explore the species composition of Malassezia\r\nmicroflora on the skin of healthy volunteers and patients with AD and PS.\r\nMethods: Species characterization was performed by conventional, culture-based methods and subsequently\r\nmolecular techniques: PCR-RFLP and sequencing of the internal transcribed spacer (ITS) 1/2 regions and the D1/D2\r\ndomains of the 26S rRNA gene. The Chi-square test and Fisher�s exact test were used for statistical analysis.\r\nResults: Malassezia sympodialis was the predominant species, having been cultured from 29 (82.9%) skin samples\r\ncollected from 17 out of 18 subjects under the study. Whereas AD patients yielded exclusively M. sympodialis\r\nisolates, M. furfur isolates were observed only in PS patients. The isolation of M. sympodialis was statistically more\r\nfrequent among AD patients and healthy volunteers than among PS patients (P <0.03). Whether this mirrors any\r\npredilection of particular Malassezia species for certain clinical conditions needs to be further evaluated. The overall\r\nconcordance between phenotypic and molecular methods was quite high (65%), with the discordant results being\r\nrather due to the presence of multiple species in a single culture (co-colonization) than true misidentification. All\r\nMalassezia isolates were susceptible to cyclopiroxolamine and azole drugs, with M. furfur isolates being somewhat\r\nmore drug tolerant than other Malassezia species.\r\nConclusions: This study provides an important insight into the species composition of Malassezia microbiota in\r\nhuman skin. The predominance of M. sympodialis in both normal and pathologic skin, contrasts with other\r\nEuropean countries, reporting M. globosa and M. restricta as the most frequently isolated Malassezia species.
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