Malassezia Species In Patients Research Articles

Distribution of Malassezia species on the skin of patients with psoriasis

IntroductionMalassezia species can induce the expression of interleukin-17 (IL-17), which plays an important role in the inflammatory and immune response in psoriasis (PS). The purpose of this study was to investigate the Malassezia species composition in patients with PS and healthy individuals and explore the role of Malassezia species in the pathogenesis of PS. Materials and methodsA total of 28 patients with PS and 10 age- and sex-matched healthy individuals participated in this study. Specimens collected from the lesional and non-lesional skin of patients with PS and the skin of healthy individuals were analyzed by using nested PCR. ResultsThe relative abundance of Malassezia species was 84.96% in healthy subjects, more than twice that in patients with PS (P<0.01). M. restricta (43.09%) and M. globosa (41.38%) were the main Malassezia species in patients with PS followed by M. furfur (4.84%) and M. sympodialis (2.49%). M. sympodialis accounted for 18. 81% of the Malassezia species in healthy subjects, which was nearly eight times higher than in patients with PS (P<0.01). Further, M. furfur was detected both on lesional and non-lesional psoriatic skin, but it was not found on the skin of healthy individuals. ConclusionsThe Malassezia species composition in patients with PS differed from that of healthy individuals. M. restricta and M. globosa were the main Malassezia species in patients with PS.

Molecular Identification of Malassezia Species in Patients with Malassezia folliculitis in Sfax, Tunisia.

Malassezia folliculitis is caused by the invasion of hair follicles by large numbers of Malassezia cells. Several Malassezia researches still use cultures, morphology and biochemical techniques. The aim of this study was to identify Malassezia species isolated from patients diagnosed with folliculitis, at the Parasitology and Mycology Laboratory of Sfax University Hospital, and to explore the genetic diversity of Malassezia by using PCR-RFLP and PCR-sequencing targeting the rDNA region of the Malassezia genome. Specimens were taken from 27 patients with Malassezia folliculitis. For the molecular identification, PCR amplification of the 26S rDNAD1/D2 region was carried out using the Malup and Maldown primers and three restriction enzymes (BanI, MspI and HeaII) for RFLP analysis. The nucleotide sequences of each isolate were compared to those in the NCBI GenBank by using BLASTIN algorithm. Three species of Malassezia yeasts were identified among the 31 Malassezia strains isolated: M. globosa (83.9%), M. sympodialis (12. 9%) and M. furfur (3.2%). The sequence analysis of M. globosa showed six genotypes. There is a high genotypic variability of M. globosa colonizing patients with folliculitis.

Study of the Distribution of Malassezia Species in Patients with Pityriasis Versicolor in Kolar Region, Karnataka.

Context:Pityriasis versicolor is a superficial, chronically recurring fungal infection caused by Malassezia species. Recently it has been revised taxanomically into 14 species, in that only 7 species have been well studied in relation to pityriasis versicolor.Aims:To identify Malassezia species isolated from patients with pityriasis versicolor and to find out any correlation between the species with clinical presentation of lesions.Settings and Design:Prospective study comprising of 100 clinically diagnosed cases of pityriasis versicolor attending Dermatology Outpatient Department over a period of 1 year.Materials and Methods:The clinical specimens were collected under aseptic precautions and subjected to culture on Sabouraud's Dextrose Agar overlaid with olive oil and modified Dixon agar. The isolates were identified by biochemical tests.Statistical Analysis Used:Statistical analysis was done using proportion, mean and chi-square test.Results:Of the 100 cases, 73% were males, 26% were females and predominant age group was 21-30 years. Out of 100 samples, 70 yielded growth. The most common isolate was M. sympodialis (50%), followed by M. furfur (32.86%), M. globosa (14.28%) and M. slooffiae (2.86%). Among 100 cases, 74% had hypopigmented and 26% had hyperpigmented lesions. M. sympodialis and M. furur were predominantly isolated from hypopigmented lesions and M. globosa and M. slooffiae were found to be more common in hyperpigmented lesions.Conclusions:M. sympodialis was the most common isolate, followed by M. furfur, M. globosa and M. slooffiae. There was no significant difference in distribution of different species in patients with hypo or hyper pigmented lesions

Distribution of Malassezia species in patients with pityriasis versicolor in Turkey

Pityriasis versicolor is a common superficial mycotic disease of the skin which is caused by different species of Malassezia genus. The aim of this study was to contribute to the knowledge of the aetiology of pityriasis versicolor (PV) with a mycological study made according to the new species and additionally, the success of the different sampling techniques, duration and recurrence history of the disease, distribution of infecting strains according to the affected body sites were also investigated. In total, 146patients with pityriasis versicolor were included in this study. Fungal elements could only be visualized by potassium hydroxide examination in 36.4% of the samples. Specimens obtained by scraping skin surface by a sterile scalpel and/or sterile sticky plaster (OpSite) were inoculated in plates containing modified Dixon's medium. Out of 146samples, 109 (74.7%) yielded a growth which was considered to be Malassezia spp. in culture. Species level identification of suspicious Malassezia yeasts was made according to their macroscopic and microscopic features, and their physiological characteristics. Among the identified species, Malassezia globosa (65.1%) was the most commonly isolated species, followed by Malassezia obtusa (17.4%). However, four Malassezia isolates could not be identified at species level with conventional methods. While most of the patients suffered their first episode of pityriasis versicolor (76%), back of the trunk was the mostly affected body site (39%). In conclusion, Malassezia globosa was found to be the predominant species in pityriasis versicolor patients in our region, and culture of the specimen is necessary for the epidemiologic purposes.

Distribution of Malassezia Species in Patients with Pityriasis versicolor Compared with Healthy Individuals in Yazd, Iran

biochemical and physiological methods. We also compared the obtained results of PV patients with normal healthy volunteers. Materials and Methods: A total of 200 persons, including 100 patients (with skin lesion) referred to Yazd Central Laboratory and 100 healthy volunteers as controls, were evaluated for Malassezia infection by morphological and biochemical methods. Results: The most commonly isolated species from PV lesions, were M. globosa (38.3%), M. furfur (29.4%), M. sympodialis (14.9%), M. pachydermatis (9.6%) and M. slooffiae (5.3%). Also the most commonly isolated species from healthy skins were M. furfur (37.2%), M. globosa (25.6%), M. sympodialis (16.3%), M. pachydermatis (13.9%) and M. slooffiae (4.6%). Totally M. globosa and M. furfur were the most frequented isolated. Conclusion: Highest prevalence of PV in our study was observed in the 20 – 39 years old group, suggesting that the peak of the infection is coincided with ages and increasing sebum production in the highest level. M. globosa was the most commonly isolated Malassezia species of the patients group and M. furfur is the most common isolated species obtained from normal individuals skin samples. We couldn’t find any significant differences between groups. The rate of isolat ed Malassezia species from patients was higher than normal individuals.

Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tertiary Care Hospital, Punjab

Purpose: Pityriasis versicolor (PV) is a chronic superficial fungal disease caused by Malassezia species. Our aim was to identify Malassezia species from PV patients and healthy individuals in Punjab. Materials and Methods: Modified Dixon agar was used as isolation culture medium. Identification was based on morphological observation and biochemical evaluation. The biochemical evaluation consisted of culture onto Sabouraud dextrose agar, catalase reaction, Tween assimilation, Cremophor EL assimilation, splitting of esculin and growth at 380C. Results: Out of 58 microscopically diagnosed cases of PV, growth was obtained from 54 (93.10%) cases. The most frequently isolated species were M. globosa, M. sympodialis and M. furfur which made up 51.79%, 31.42% and 18.51% of the isolated etiological agents respectively. However, the major isolate from the back of healthy individuals was M. sympodialis (47.61%), followed by M.obtusa (19.04%), M. globosa (14.20%), M. furfur (9.52%), M. pachydermatis (4.76%) and M. slooffiae (4.76%). Conclusions:M. globosa in its mycelial phase was the main etiological agent, but as normal flora from the back of healthy subjects, it was found in significantly less number (P = 0.01), suggesting that the higher pathogenicity of M. globosa in terms of enzymatic endowment, might be the cause of its predominance in PV lesions.

Identification of Malassezia Species in Patients with Seborrheic Dermatitis in China

The causes of seborrheic dermatitis (SD) are complex and incompletely understood. Among the factors, Malassezia yeasts have been reported to play a major etiological role in SD. Many previous studies adopted conventional culture methods that were disadvantaged to detect Malassezia microflora in SD patients, resulting in a low detection rate for each species and high variance in types of microflora observed. This study analyzed Malassezia microflora in SD patients by applying a transparent dressing to the lesional skin and using direct detection of fungal DNA using nested PCR. We collected samples from the lesional skin of 146 SD patients in China and extracted fungal DNA directly from the lesional samples without culture. Specific primers for each Malassezia species were designed to amplify existing yeasts in each sample. Some samples were randomly selected to culture and identified by morphological and physiologic criteria. M. globosa and M. restricta were found in 87.0 and 81.5% of seborrheic dermatitis patients, respectively, which together accounted for more than 50% of Malassezia spp. recovered in these Chinese patients. The majority of SD patients (82.9%) showed co-colonization of two or more Malassezia species. M. globosa and M. restricta predominated in Malassezia colonization in Chinese SD patients. Compared with conventional culture, non-culture-based methods may more accurately reflect Malassezia microflora constitution.

Epidemiology of pityriasis versicolor in Adana, Turkey

Pityriasis versicolor is a common superficial mycoses of the skin. It is now recognized that the causative organisms of this infection are different species of Malassezia. The aim of this study was to determine the distribution of Malassezia species in patients with pityriasis versicolor in Adana, Turkey. In total, 97 patients positive for Malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. All samples were inoculated in plates containing modified Dixon's medium. However, only 44 of the patients (45.4%) showed Malassezia spp. in culture. Malassezia globosa (47.7%) was the most commonly isolated species followed by Malassezia furfur (36.4%) and Malassezia slooffiae (15.9%). Mixed Malassezia species were not isolated. In conclusion, M. globosa was found to be the predominant PV isolate in Adana, Turkey.

Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tehran, Iran.

BackgroundPityriasis versicolor is a superficial infection of the stratum corneum which caused by a group of yeasts formerly named pityrosporium. The taxonomy of these lipophilic yeasts has recently been modified and includes seven species referred as Malassezia. The aim of this study is to compare the distribution of Malassezia species isolated from pityriasis versicolor lesions and those isolated from healthy skins.MethodsDifferentiation of all malassezia species performed using morphological features and physiological test including catalase reaction, Tween assimilation test and splitting of esculin.ResultsIn pityriasis versicolor lesions, the most frequently isolated species was M. globosa (53.3%), followed by M. furfur (25.3%), M. sympodialis(9.3%), M. obtusa (8.1%) and M. slooffiae (4.0%). The most frequently isolated species in the skin of healthy individuals were M. globosa, M. sympodialis, M. furfur, M. sloofiae and M. restricta which respectively made up 41.7%, 25.0%, 23.3%, 6.7% and 3.3% of the isolated species.ConclusionsAccording to our data, M. globosa was the most prevalent species in the skin of healthy individuals which recovered only in the yeast form. However, the Mycelial form of M. globosa was isolated as the dominant species from pityriasis versicolor lesions. Therefore, the role of predisposing factors in the conversion of this yeast to mycelium and its subsequent involvement in pityriasis versicolor pathogenicity should be considered.

Immunology of diseases associated with Malassezia species.

Malassezia species are members of the human cutaneous commensal flora, in addition to causing a wide range of cutaneous and systemic diseases in suitably predisposed individuals. Studies examining cellular and humoral immune responses specific to Malassezia species in patients with Malassezia-associated diseases and healthy controls have generally been unable to define significant differences in their immune response. The use of varied antigenic preparations and strains from different Malassezia classifications may partly be responsible for this, although these problems can now be overcome by using techniques based on recent work defining some important antigens and also a new taxonomy for the genus. The finding that the genus Malassezia is immunomodulatory is important in understanding its ability to cause disease. Stimulation of the reticuloendothelial system and activation of the complement cascade contrasts with its ability to suppress cytokine release and downregulate phagocytic uptake and killing. The lipid-rich layer around the yeast appears to be pivotal in this alteration of phenotype. Defining the nonspecific immune response to Malassezia species and the way in which the organisms modulate it may well be the key to understanding how Malassezia species can exist as both commensals and pathogens.

Molecular analysis of malassezia microflora on the skin of atopic dermatitis patients and healthy subjects

We compared cutaneous colonization levels of Malassezia species in patients with AD and healthy subjects using nested PCR. Malassezia-specific DNA was detected in all 32 of the patients with AD. M. globosa and M. restricta were detected in approximately 90% of these patients, with M. furfur and M. sympodialis being detected in approximately 40% of the cases. In healthy subjects, Malassezia DNA was detected in 78% of the samples, M. globosa, M. restricta and M. sympodialis were detected at frequencies ranging from 44 to 61%, and M. furfur was found in 11% of healthy subjects. Our results suggest that M. furfur, M. globosa, M. restricta and M. sympodialis are common inhabitants of the skin of both AD patients and healthy subjects, while the skin microflora of patients with AD shows more diversity than that of healthy subjects.

Identification of Malassezia Species Isolated From Patients With Pityriasis Versicolor in Sari, Iran, 2012

Background: 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.