Identification of Malassezia Species in Patients with Pityriasis Versicolor Submitted to the Razi Hospital in Tehran (original) (raw)
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Isolation of Malassezia globosa and M. sympodialis from patients with pityriasis versicolor in Spain
Mycopathologia, 2002
Pityriasis versicolor is a superficial infection of the stratum corneum by several yeast species formerly collectively named Malasseziafurfur. The genus Malassezia has been recently enlarged with new species. With the exception of M. pachydermatis, the remaining six species have an absolute requirement in vitro for supplementation of long-chain fatty acids in media. These lipophilic yeasts comprise six species: M. furfur, M. globosa, M. obtusa, M. restricta, M. slooffiae and M. sympodialis. The aim of this study was to establish whether there was any association between the various species of Malassezia and pityriasis versicolor lesions. Thus, we studied the isolates from 79 patients with pityriasis versicolor, both from lesions and from apparently healthy skin close to the visible lesions. In pityriasis versicolor lesions, the species most frequently isolated was M. globosa (90%), followed by M. sympodialis (41%). Almost all isolates (99%) belonged to one of these two species. The ...
Identification of Different Malassezia Species Isolated from Patients with Malassezia Infections
Yeasts of the genus Malassezia are known as the microflora of human skin and that of many warmblooded animals; but the different Malassezia species can induce superficial skin infections. Best known and most frequent is pityriasis versicolor (PV), a chronic and recurrent skin disease occurring primarily in hot and humid climates. The purpose of the present study was to make use of the metabolic differences and assay techniques, to compare the distribution of Malassezia species and gain insight into the epidemiology and ecology of the species identified. In this study, 25 patients with approved (PV) were selected and skin samples were cultured on Sabouraud glucose agar and mDixon. Differentiation of Malassezia species was performed using of assimilation of Tweens, catalase reaction, splitting of esculin and growth without addition of lipids. M. globosa (42.85%), M. furfur (31.4%), M. sympodialis (11.42%), M. pachydermatis (8.57%) and M. obtusa (5.71%) were the most important isolated. Interestingly, in 10 patients two different malassezia species were isolated. Regarding to the results of this study, M. furfur and M. globosa were the most prevalent species in the skin of patients with PV; so these organisms can jointly cause the infections. It is necessary to investigate of epidemiology and ecology of distribution of Malassezia species.
Clinical and epidemiological features of the genus Malassezia in Iran
Iranian journal of microbiology, 2014
The genus Malassezia contains an expanding list of lipophilic yeasts involve in the etiology of various superficial fungal infections. Pityriasis versicolor (PV) is the most prevalent Malassezia-related infection distributed worldwide. In the present study, clinical and epidemiological features of the genus Malassezia are discussed with special focus on PV in Iran. During June 2012 to April 2013, among 713 confirmed cases of fungal infections, 68 (9.5%) were diagnosed as PV by positive direct microscopy results in 20% potassium hydroxide (KOH) preparation of skin scrapings. All the specimens were cultured on modified Dixon agar and incubated at 32°C for 10 days. Identification of the isolated yeasts was carried out based on macro- and microscopic morphology, catalase test, utilization of Tweens, polyethoxylated castor oil (EL slant), and hydrolysis of esculin and utilization of Tween-60 (TE slant). Out of 68 skin scrapings, 55 (80.9%) yielded yeast colonies on mDixon's agar whic...
2004
The present study is designed to evaluate the application of a simple method for rapid identification of Malassezia furfur among other Malassezia spp. based on production of a brownish-red pigment and its diffusion into the medium containing L-tryptophan as a sigle source of nitrogen. 91 strains of Malassezia (20% M. furfur, 2% M. sympodialis, 5% M. obtosa and 73% M. globosa) isolated from skin scales of 138 patients with pityriasis versicolor were examined. Reference Malassezia strains of all 7 species obtained from Centraalbureau voor Schimmelcultures, Baarn, the Netherlands, together with Candida albicans and Rhodotorula sp. were also studied. All of these strains were cultured on modified Dixon agar medium prepared by replacing pepton with equal amount (0.6%) of Ltryptophan. The pigment producing ability was evaluated after 7 days incubation of the cultures at 32 ºC. Out of yeast species tested, all M. furfur strains produced specific brown pigment, whereas strains belonging to all other known Malassezia spp. and also several other yeasts failed to produce pigment. The results obtained further substantiated that study of pigment producing ability on this specific medium can be used as a simple and reliable test for rapid differentiation of M. furfur from other closely related Malassezia spp.. Iran J Med Sci 2004; 29(1):36-39.
Prevalence of Malassezia species in patients with pityriasis versicolor in Rosario, Argentina
Revista Iberoamericana de Micología, 2012
Background: Malassezia species are considered opportunistic yeasts of increasing clinical importance. These lipophilic yeasts are associated with various human diseases, especially pityriasis versicolor (PV), a chronic superficial scaling dermatomycosis. Aims: The aim of this study was to isolate, identify and analyze the distribution of the different species of Malassezia in patients with PV in Rosario city (Argentina). Methods: A total of 264 clinical samples were studied. Isolates were identified on the basis of microscopic observation of cells, and physiological properties, such as the presence of catalase, ability to use Tween compounds, splitting of esculin, and morphology, color and precipitate production on chromogenic agar CHROMagar-Malassezia medium (CHROMM). Results: The highest prevalence of PV in this study was observed in the 25-to 45-year-old group. No differences were found in the development of PV between sexes. The most affected areas of body were the trunk and face. Malassezia sympodialis (51%) was the most commonly isolated species, followed in frequency by M. globosa (40%), Malassezia furfur (7%), Malassezia obtusa (1%) and Malassezia slooffiae (1%). Conclusions: The success for a correct identification of these yeasts is important to improve our knowledge about their epidemiological role in PV and also to detect the appearance of strains which are resistant to the commonly used antifungal drugs.
Medical Mycology, 2000
The genus Malassezia is part of the normal mycota of the skin of humans and other warm-blooded animals as etiological agents of pityriasis versicolor. Objectives: Several species from the Malassezia genus are known based on morphological, biochemical and molecular approaches. Therefore, the aim of this study was to determine the distribution of Malassezia species in patients with pityriasis versicolor based on morphological, physiological and biochemical criteria in Sari, Iran. Materials and Methods: In total, among 134 patients clinically suspected of having pityriasis versicolor, attending the Department of Mycology, Boali Sina Hospital and Referral Laboratory of the Mazandaran University of Medical Sciences, 116/134 (86.5%) positive patients for Malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. All 116 samples were inoculated on plates containing modified Leeming and Notman agar medium and identified at species level based on mycological criteria. Results: However, only 100/116 (86.2%) or 100/134 (74.6 %) of the patients showed Malassezia spp in culture. Malassezia. globosa (54%) was the most commonly isolated species followed by M. furfur (32%), M. slooffiae (6%), M. restricta (6%) and M. sympodialis (2%). Mixed Malassezia species were not identified. Conclusions: M. globosa was found to be the predominant pityriasis versicolor isolate in Sari, Iran. Since Malassezia species show different responses in their antifungal therapy, thus correct identification of Malassezia species and antifungal susceptibility test could facilitate selection of appropriate antifungal agents.
Revista Iberoamericana de Micologia, 2013
The genus Malassezia is part of the normal mycota of the skin of humans and other warm-blooded animals as etiological agents of pityriasis versicolor. Objectives: Several species from the Malassezia genus are known based on morphological, biochemical and molecular approaches. Therefore, the aim of this study was to determine the distribution of Malassezia species in patients with pityriasis versicolor based on morphological, physiological and biochemical criteria in Sari, Iran. Materials and Methods: In total, among 134 patients clinically suspected of having pityriasis versicolor, attending the Department of Mycology, Boali Sina Hospital and Referral Laboratory of the Mazandaran University of Medical Sciences, 116/134 (86.5%) positive patients for Malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. All 116 samples were inoculated on plates containing modified Leeming and Notman agar medium and identified at species level based on mycological criteria. Results: However, only 100/116 (86.2%) or 100/134 (74.6 %) of the patients showed Malassezia spp in culture. Malassezia. globosa (54%) was the most commonly isolated species followed by M. furfur (32%), M. slooffiae (6%), M. restricta (6%) and M. sympodialis (2%). Mixed Malassezia species were not identified. Conclusions: M. globosa was found to be the predominant pityriasis versicolor isolate in Sari, Iran. Since Malassezia species show different responses in their antifungal therapy, thus correct identification of Malassezia species and antifungal susceptibility test could facilitate selection of appropriate antifungal agents.