Distribution of Malassezia species on the skin of patients with atopic dermatitis, psoriasis, and healthy volunteers assessed by conventional and molecular identification methods

Abstract

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

How the microbiota shapes rheumatic diseases

“…Changes in this balance and in the composition of the skin microbiota have been associated with the pathogenesis of psoriasis [65][66][67][68][69] .…”

Etiopathogenetic Therapy of Inflammatory Dermatoses

“…утяжеляет течение основного за-болевания посредством стимуляции выброса тими-ческого стромального лимфопоэтина кератиноци-тами. При этом патогенная микрофлора негативно влияет на течение хронического иммунозависимого воспалительного дерматоза, что диктует необходи-мость контроля над обсемененностью кожи ключе-выми микробными агентами -S. aureus, грибами родов Malassezia и Candida [3,4].…”

Recovery of lipophilic Malassezia species from two infants with otitis media in Monterrey, Nuevo Len, Mexico

“…Other techniques, such as PCR-RFLP (Jagielski et al, 2014) and multiplex PCR methods (Vuran et al, 2014) have also been proposed and are useful to identify Malassezia species directly obtained from patients samples.…”