Molecular identification of Malassezia species isolated from dermatitis affections

Abstract

The lipophilic yeast of the genus Malassezia are opportunistic microorganisms of the skin microflora but they can be agents of various dermatomycoses. The aim of this study was to perform molecular identification of the commonly isolated Malassezia species from various dermatomycoses in our region. Thirty strains of Malassezia were isolated from different dermatologic affections: pityriasis versicolor (17), dandruff (5), seborrheic dermatitis (4), onyxis (2), folliculitis (1) and blepharitis (1). These species were identified by their morphological features and biochemical characterisation. The molecular identification was achieved by amplification of the internal transcribed spacer region by simple PCR. PCR technique was used for molecular characterisation of four Malassezia species: Malassezia globosa (270 bp), Malassezia furfur (230 bp), Malassezia sympodialis (190 bp) and Malassezia restricta (320 bp). We have detected the association between M. furfur and M. sympodialis in 16% and confirmed presumptive identification in 70% of the cases. The phenotypic identification based on microscopic and physiological method is difficult and time consuming. The application of a simple PCR method provides a sensitive and rapid identification system for Malassezia species, which may be applied in epidemiological surveys and routine practice.

Detection of Malassezia Species Isolated From Patients With Pityriasis Versicolor and Seborrheic Dermatitis Using Nested-PCR

“…In most epidemiological studies in the world, M. globosa has been isolated more than any other species of Malassezia from patients with pityriasis versicolor (15,(17)(18)(19)(20)(21). In this study, M. furfur was the predominant species in patients, this difference with previous studies might be justified by Malassezia species dispersion in different geographic regions and also differences in methods used to identify the species.…”

The Role of L-DOPA on Melanization and Mycelial Production in Malassezia Furfur

“…Direct examination of skin was performed and the presence of Malassezia was confirmed by culturing on mDixon agar incubated at 30°C for 2 weeks. The Malassezia yeasts were identified to species level using polymerase chain reaction (PCR) as described [35]. To examine Malassezia melanization in vivo , the skin was digested with 1.0 mg/ml of Proteinase K (Roche) at 37°C for 2 h, and washed three times with PBS (modified from Youngchim et al [36]).…”

Differential lipase virulence in Malassezia furfur dimorphism isolated from pityriasis versicolor patients and healthy individuals

“…The collection of the clinical isolates was approved by the University's review board and performed in compliance with the University's requirements for human studies (Ethical approval number: HE561487). The clinical isolates of M. furfur were identified by conventional techniques based on the morphological, biochemical and physiological characteristics, and then confirmed by a molecular method 29 …”

“…The clinical isolates of M. furfur were identified by conventional techniques based on the morphological, biochemical and physiological characteristics, and then confirmed by a molecular method. 29 All cultures were grown on Modified Dixon medium for 3 days at 30°C (mDixon; 1 L of distilled water, 36 g malt extract, 6 g peptone, 20 g ox bile (all obtained from Difco Laboratories), 10 mL Tween 40, 2 mL glycerol, 2 mL olive oil (all obtained from Sigma) 0.05 g Chloramphenicol (Amresco Inc.) and 15.0 g agar (Difco Laboratories) with a pH 6.0). 30 Malassezia yeasts were harvested by adding 3.0 mL of sterile PBS to the culture plates and gently scraping with a loop.…”