Karyotyping of Malassezia Yeasts: Taxonomic and Epidemiological Implications

Boekhout, Teun; Bosboom, Ron

doi:10.1016/s0723-2020(11)80043-3

Cited by 57 publications

(42 citation statements)

References 31 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: 91%

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: 91%

Revised Culture-Based System for Identification of Malassezia Species

et al. 2007

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“…For example, M. furfur infections have been observed in hospitalized neonates with very low birth weights receiving intravenous lipid emulsions (5,7,15,23,41,46). M. globosa, which corresponds to the original description of Pityrosporum orbiculare and correlates to the former serovar B of M. furfur (14), may be the most important species in pityriasis versicolor, either alone or in association with other species, such as M. sympodialis (11,12,29).…”

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confidence: 93%

“…M. restricta, which corresponds to the former serovar C of M. furfur (14) and which visually resembles Pityrosporum ovale, is the species most often associated with seborrheic dermatitis and dandruff. M. pachydermatis, the non-lipid-dependent species, is rarely observed in humans but has been found to cause septic outbreaks (5,38,49).…”

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confidence: 99%

Fast, Noninvasive Method for Molecular Detection and Differentiation of Malassezia Yeast Species on Human Skin and Application of the Method to Dandruff Microbiology

et al. 2002

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Malassezia fungi have been the suspected cause of dandruff for more than a century. Previously referred to as Pityrosporum ovale, Pityrosporum orbiculare, or Malassezia, these fungi are now known to consist of at least seven Malassezia species. Each species has a specific ecological niche, as well as specific biochemical and genetic characteristics. Malassezia yeasts have fastidious culture conditions and exceedingly different growth rates. Therefore, the results of surveys of Malassezia based on culture methods can be difficult to interpret. We developed a molecular technique, terminal fragment length polymorphism analysis, to more accurately survey the ecology of Malassezia yeasts without bias from culture. This technique involves fluorescent nested PCR of the intergenic transcribed spacer (ITS) ITS I and ITS II region ribosomal gene clusters. All known Malassezia species can be differentiated by unique ITS fragment lengths. We have used this technique to directly analyze scalp samples from subjects enrolled in a demographic scalp health study. Results for subjects assigned composite adherent scalp flaking scores (ASFS) <10 were compared to those for subjects assigned composite ASFS >24. Malassezia restricta and M. globosa were found to be the predominant Malassezia species present in both groups. Importantly, we found no evidence of M. furfur in either group, indicating that M. furfur can be eliminated as the causal organism for dandruff. Both groups also showed the presence of non-Malassezia fungi. This method, particularly when it is used in combination with existing fungal ITS databases, is expected to be useful in the diagnosis of multiple other fungal infections.Recently, members of the genus Malassezia have become viewed as opportunistic yeasts of increasing importance (1, 2, 31, 35, 42). They are lipophilic or lipid-dependent yeasts, and at least some belong to the normal cutaneous microflora. Some Malassezia species may act as pathogens when exposed to certain changes in the skin microclimate. For decades the genus Malassezia remained limited to two species, namely, the lipiddependent Malassezia furfur and the lipophilic M. pachydermatis. In 1995, 28S rRNA gene sequences revealed seven distinct genetic entities (25), which are now accepted as species (M. furfur, M. obtusa, M. globosa, M. slooffiae, M. sympodialis, M. pachydermatis, and M. restricta) (22). Malassezia species are exceptionally difficult to cultivate, so additional species may be discovered as DNA-based differentiation techniques are refined and applied to multiple ecosystems.While several of the seven described Malassezia species have been associated with human infection, the pathological role of each species is not fully understood. For example, M. furfur infections have been observed in hospitalized neonates with very low birth weights receiving intravenous lipid emulsions (5,7,15,23,41,46). M. globosa, which corresponds to the original description of Pityrosporum orbiculare and correlates to the former serovar B of M. furfur (14), ...

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“…Phylogenetic classification of the genus has been investigated by molecular studies that used the base sequence of partial 28S rRNA [9,12], karyotyping [13,14] and random amplified polymorphic DNA (RAPD) [15]. Although all the above mentioned were applied successfully to clinical isolates, the following disadvantages were identified: 28S rRNA typing required an extensive length of 627 bp for preparation of intact RNA sequences; karyotyping was time-consuming and intraspecific differences were limited; RAPD analysis produced rapid results, but was sometimes unreliable.…”

Section: Introductionmentioning

confidence: 99%

Species identification and strain typing of Malassezia species stock strains and clinical isolates based on the DNA sequences of nuclear ribosomal internal transcribed spacer 1 regions

Makimura

Tamura

Kudo

et al. 2000

Journal of Medical Microbiology

115

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This study demonstrated the application of internal transcribed spacer 1 (ITS1) ribosomal DNA sequences to the species identification and strain typing of 28 standard strains and 46 clinical isolates of the genus Malassezia. The size of ITS1 regions ranged from 162 to 266 bp. Members of the genus Malassezia (M. pachydermatis, M. furfur, M. sympodialis, M. globosa, M. obtusa, M. restricta and M. slooffiae) were classified into seven ITS1-homologous groups and 22 ITS1-identical, individual groups. The 46 clinical isolates of lipophilic Malassezia spp. were identified as belonging to just three ITS1-homologous groups, i.e., M. furfur (19 strains: 11 from pityriasis versicolor, 4 from seborrhoeic dermatitis and 4 from atopic dermatitis). M. sympodialis (22 strains: 7 from pityriasis versicolor, 3 from seborrhoeic dermatitis, 1 from atopic dermatitis and 11 from healthy controls) and M. slooffiae (five strains: three from chronic otitis media and two from healthy controls).

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Karyotyping of Malassezia Yeasts: Taxonomic and Epidemiological Implications

Cited by 57 publications

References 31 publications

Revised Culture-Based System for Identification of Malassezia Species

Revised Culture-Based System for Identification of Malassezia Species

Fast, Noninvasive Method for Molecular Detection and Differentiation of Malassezia Yeast Species on Human Skin and Application of the Method to Dandruff Microbiology

Species identification and strain typing of Malassezia species stock strains and clinical isolates based on the DNA sequences of nuclear ribosomal internal transcribed spacer 1 regions

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