Molecular typing of<i>Malassezia</i>species with PFGE and RAPD

Boekhout, Teun; Kamp, Marga; Guého, E.

doi:10.1080/02681219880000581

Cited by 92 publications

(82 citation statements)

References 34 publications

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“…Recently, data from several institutions have suggested that M. globosa is associated with pityriasis versicolor (19,20), that M. restricta is associated with seborrheic dermatitis (24,29), and that M. furfur infections have been observed in hospitalized neonates with very low birth weight receiving intravenous lipid emulsions (2,3,4,7,23,28). In agreement with these reports, we isolated mainly M. globosa from pityriasis versicolor and M. restricta from seborrheic dermatitis in the present study.…”

Section: Discussionsupporting

confidence: 81%

Revised Culture-Based System for Identification of Malassezia Species

et al. 2007

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Forty-six strains of Malassezia spp. with atypical biochemical features were isolated from 366 fresh clinical isolates from human subjects and dogs. Isolates obtained in this study included 2 (4.7%) lipiddependent M. pachydermatis isolates; 1 (2.4%) precipitate-producing and 6 (14.6%) non-polyethoxylated castor oil (Cremophor EL)-assimilating M. furfur isolates; and 37 (34.3%) M. slooffiae isolates that were esculin hydrolyzing, 17 (15.7%) that were non-tolerant of growth at 40°C, and 2 (1.9%) that assimilated polyethoxylated castor oil. Although their colony morphologies and sizes were characteristic on CHROMagar Malassezia medium (CHROM), all strains of M. furfur developed large pale pink and wrinkled colonies, and all strains of M. slooffiae developed small (<1 mm) pale pink colonies on CHROM. These atypical strains were distinguishable by the appearance of their colonies grown on CHROM. Three clinically important Malassezia species, M. globosa, M. restricta, and M. furfur, were correctly identified by their biochemical characteristics and colony morphologies. The results presented here indicate that our proposed identification system will be useful as a routine tool for the identification of clinically important Malassezia species in clinical laboratories.Members of the genus Malassezia are among the microbiological flora of the skin of homoiothermic animals. Most species of this genus are lipid-dependent yeasts which colonize the seborrheic part of the skin, and they have been reported to be associated with pityriasis versicolor, seborrheic dermatitis, Malassezia folliculitis, and atopic dermatitis (1,6,19,20,24,29). Although M. furfur was previously thought to be the causative agent or trigger factor in all of these skin disorders, Guého et al. (9) reclassified this genus into five species in 1996. Malassezia has since been reclassified into seven species based on molecular biological analysis of nuclear ribosomal DNA/ RNA (9, 10), and the results agreed with those of mitochondrial ribosomal DNA analyses (30). As members of the genus Malassezia share similar morphological and biochemical characteristics, it was thought that differentiating between them based on phenotypic features would be difficult. While molecular biological techniques are the most reliable for the identification of Malassezia, they are not available in most clinical laboratories. Therefore, culture methods for the identification of Malassezia species are required. Some of these identification or differentiation methods have been reported previously. Guillot et al. reported a method of identification based on lipid usage pattern, catalase reaction, growth temperature, and cell shape (11). Hammer and Riley reported the production of a precipitate by some Malassezia strains on Dixon's agar (12); for example, M. furfur, M. obtusa, and M. slooffiae were precipitate-negative strains, while M. sympodialis and M. globosa were precipitate-positive strains. Mayser et al. reported that some Malassezia species hydrolyzed esculin and assimilated pol...

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Section: Discussionsupporting

confidence: 81%

Revised Culture-Based System for Identification of Malassezia Species

et al. 2007

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“…Indeed, colonies of this species vary in size and form and show a high degree of cellular pleomorphism, including oval, cylindrical, and spherical cells (18,22). Techniques such as randomly amplified polymorphic DNA and amplified fragment length polymorphism have demonstrated high intraspecific variability in this species (2,5,44). The atypical assimilation pattern of our isolates, involving an inability to utilize Tween 20, 40, or 60, reveals a metabolic variation probably resulting from alternate gene expression.…”

Section: Discussionmentioning

confidence: 96%

Physiological and Molecular Characterization of Atypical Isolates of Malassezia furfur

et al. 2009

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The species constituting the genus Malassezia are considered to be emergent opportunistic yeasts of great importance. Characterized as lipophilic yeasts, they are found in normal human skin flora and sometimes are associated with different dermatological pathologies. We have isolated seven Malassezia species strains that have a different Tween assimilation pattern from the one typically used to differentiate M. furfur, M. sympodialis, and M. slooffiae from other Malassezia species. In order to characterize these isolates of Malassezia spp., we studied their physiological features and conducted morphological and molecular characterization by PCR-restriction fragment length polymorphism and sequencing of the 26S and 5.8S ribosomal DNA-internal transcribed spacer 2 regions in three strains from healthy individuals, four clinical strains, and eight reference strains. The sequence analysis of the ribosomal region was based on the Blastn algorithm and revealed that the sequences of our isolates were homologous to M. furfur sequences. To support these findings, we carried out phylogenetic analyses to establish the relationship of the isolates to M. furfur and other reported species. All of our results confirm that all seven strains are M. furfur; the atypical assimilation of Tween 80 was found to be a new physiological pattern characteristic of some strains isolated in Colombia.The genus Malassezia comprises lipophilic yeasts found in the normal flora of human skin and other mammals. These yeasts were described by Eichstedt in 1848 as being associated with pityriasis versicolor (PV) lesions (13). The taxonomy and nomenclature of the genus Malassezia was controversial for many decades. Indeed, until 1990 only three species were recognized: M. furfur, M. sympodialis, and M. pachydermatis, a non-lipid-dependent species (17,21,38 (4,6,11,17,18,20,21,26,34,38,(40)(41)(42).Malassezia species have been associated with diverse dermatological pathologies, including PV, seborrheic dermatitis dandruff, atopic dermatitis, folliculitis, psoriasis, onicomycosis, and blepharitis. M. furfur and M. pachydermatis have been associated with systemic infections in patients with underlying diseases and those receiving intravenous lipid emulsions (6, 7, 9-11, 16, 29, 33, 34).Although the role of Malassezia species in the development of these diseases is not clear, some authors suggest that M. globosa is the causal agent of PV, while others have found a greater percentage of isolates of M. sympodialis associated with the disease. Differences in diagnosis might be due to sampling methods and differences between the culture media used, leading to controversies in clinical studies of these dermatological pathologies (1, 7, 9, 10). New physiological patterns for identification have been described, and recently the availability of molecular biology and sequencing techniques has allowed the species to be distinguished more clearly (17-21). Despite the difficulty in isolating, maintaining, and identifying these yeasts, different characteristics of ...

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“…The DNA relatedness of the isolates was based on RAPD and AFLP analyses. The RAPD analysis used primers M13, GTG5, OPA2, and OPA4, as described by Boekhout et al (5). The patterns of the individual primers were compared and summarized in one overall classification scheme.…”

Section: Methodsmentioning

confidence: 99%

Multidrug-Resistant Trichosporon asahii Infection of Nongranulocytopenic Patients in Three Intensive Care Units

et al. 2001

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Trichosporon asahii (Trichosporon beigelii) infections are rare but have been associated with a wide spectrum of clinical manifestations, ranging from superficial involvement in immunocompetent individuals to severe systemic disease in immunocompromised patients. We report on the recent recovery of T. asahii isolates with reduced susceptibility in vitro to amphotericin B (AMB), flucytosine, and azoles from six nongranulocytopenic patients who exhibited risk factors and who developed either superficial infections (four individuals) or invasive infections (two individuals) while in intensive care units. The latter two patients responded clinically and microbiologically to AMB treatment. All six isolates were closely related according to random amplified polymorphic DNA studies and showed 71% similarity by amplified fragment length polymorphism analysis, suggesting a common nosocomial origin. We also review the literature pertaining to T. asahii infections and discuss the salient characteristics of this fungus and recent taxonomic proposals for the genus.Trichosporon infections are associated with a wide spectrum of clinical manifestations, ranging from superficial cutaneous involvement in immunocompetent individuals to severe systemic disease in immunocompromised patients (9, 44). Trichosporon asahii (Trichosporon beigelii) has increasingly been described as an opportunistic pathogen involved in disseminated infections in patients with profound granulocytopenia (9,11,26). Less commonly reported risk factors associated with infections caused by this agent include treatment with immunosuppressive drugs, transplantation, AIDS, extensive burns, and the presence of implanted prosthetic devices (9,11,14,20,24,27,29).Trichosporon species were the most common non-Candida cause of fungemia at a national cancer institute (23). Disseminated Trichosporon infections in immunocompromised patients are frequently fatal, despite therapy with amphotericin B (AMB) (9,44,46). This antifungal agent has been shown to have a limited in vitro effect against Trichosporon species. In contrast, azoles have been demonstrated to have in vitro activity against members of this genus and their use has been associated with favorable responses in animal models (2,3,9,27,31,32,45,46).We report on the recent recovery of T. asahii isolates resistant in vitro to AMB and azoles from six nongranulocytopenic patients who developed either invasive or superficial infections while hospitalized in different intensive care units (ICUs). We describe the demographic and major clinical characteristics of these patients and review the literature pertaining to T. asahii infections. Results from molecular biology-based studies based on random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) analyses suggest that the isolates recovered from specimens of these six patients were closely related. In addition, we discuss the salient characteristics of this fungus and recent taxonomic proposals for the genus. MATERIALS AND METHODSCase re...

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Molecular typing ofMalasseziaspecies with PFGE and RAPD

Cited by 92 publications

References 34 publications

Revised Culture-Based System for Identification of Malassezia Species

Revised Culture-Based System for Identification of Malassezia Species

Physiological and Molecular Characterization of Atypical Isolates of Malassezia furfur

Multidrug-Resistant Trichosporon asahii Infection of Nongranulocytopenic Patients in Three Intensive Care Units

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