Malassezia Species Associated With Dermatitis in Dogs and Their Antifungal Susceptibility (original) (raw)
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Journal of Fungi
Malassezia yeasts have recently gained medical importance as emerging pathogens associated with a wide range of dermatological and systemic infections. Since standardized methods for in vitro antifungal susceptibility testing have not yet been established for Malassezia spp., related diseases are always treated empirically. As a result, a high rate of recurrence and decreased antifungal susceptibility have appeared. Thus, the aims of the study were to assess and analyze the in vitro susceptibility of Malassezia isolated from pityriasis versicolor (PV) lesions and healthy controls. A total of 58 Malassezia strains isolated from PV patients and healthy controls were tested. In vitro antifungal susceptibility testing was conducted using the CLSI broth microdilution with some modifications. Candida spp. criteria established in accordance with CLSI guidelines were used for data interpretation. Ketoconazole and posaconazole seemed to be the most effective molecules against Malassezia spec...
Interesting effect of Malassezia spp. infection on dermatoses of other origins
International Journal of Dermatology, 2011
Background Tinea versicolor (TV) is a superficial fungal infection affecting as many as 40% of the population in the tropics. We noticed an unusual affect of TV on dermatoses of other origins. Methods In this prospective clinical study, we examined patients attending our dermatology outpatient department over a period of one year for coexistence of TV with any unrelated dermatoses. We confirmed the diagnosis of TV by microscopy of skin scrapings. Skin biopsy was performed when necessary to confirm the diagnosis of associated dermatoses. Results We describe four cases in which unrelated dermatoses (viral exanthem, acute generalized exanthematous pustulosis, polymorphous light eruption, and irritant contact dermatitis) specifically spared sites affected with TV. Conclusions Recent research has elucidated the immunomodulatory properties of Malassezia spp. in vitro. Our cases serve as possible in vivo models illustrating such properties. Further studies based on these reports could lead to the isolation of molecules from Malassezia, which may have potential use in anti-inflammatory drug formulations.
Acta dermatovenerologica Croatica : ADC, 2016
There are differences with respect to the commonly isolated Malassezia species, not only between healthy individuals and the patients with various skin diseases, but also between different countries. We investigated the species composition of Malassezia microflora on the skin of patients with Malassezia-associated diseases and of healthy subjects (HS). Two hundred and fifty skin scrapings from patients with pityriasis versicolor (PV), seborrheic dermatitis (SD), atopic dermatitis (AD), psoriasis (PS), and healthy subjects (HS), fifty each, were inoculated into Sabouraud dextrose agar and into modified Dixon agar and identified using conventional culture-based methods. In PV and PS lesions, the most common species was M. globosa (62% and 52%, respectively), while M. restricta was predominant in SD lesions (28%). M. sympodialis was the most common species recovered from AD (52%) and healthy trunk skin (30%). Fewer cultures were positive for Malassezia growth in patients with AD than i...
Molecular and conventional identification of Malassezia spp.in Malassezia spp.associated dermatoses
Abou Zeid M.,El Mohammady A.,El Fangary M.,Saudi W.,Abdalla T.Tamer M.and M.Taha Journal of Egyptian Women;sDermatology Association(JEWDS) vol.12,issue 1 page 68-76. January 2015 Background: Malassezia spp. yeasts are known to be associated with pityriasis versicolor, seborrheic dermatitis, dandruff, and Malassezia folliculitis. Recently, their pathogenicity is being expanded to other skin disorders, such as atopic dermatitis, psoriasis, and acne vulgaris. Identification of Malassezia spp. yeasts has been carried out mostly through morphological and biochemical analyses. Various molecular biological techniques are now available and being preferred as they are species-specific, and therefore are more accurate and less time-consuming. Objective: The purpose of this study was to elucidate the pathogenic role of Malassezia spp. in Malassezia spp.-related skin diseases, and to evaluate the reliability of PCR as a molecular diagnostic tool in identification compared with conventional methods. Patients and methods: Conventional identification of Malassezia spp. and molecular analysis using PCR-restriction fragment polymorphism (PCR-RFLP) was carried out on someMalassezia spp.-associated dermatoses. Results: Three Malassezia spp. were identified (Malassezia furfur, Malassezia globosa, and Malassezia sympodialis), and the results of the conventional identification were in accordance with the pattern obtained from 26S rDNA (or large subunit ribosomal DNA) PCR-RFLP. Conclusion: 26S rDNA PCR-RFLP method confirmed the conventional identification ofMalassezia spp. in Malassezia spp.-associated dermatoses in our study. Further species-specific and strain-specific identification may help elucidate the role of the individual species in various diseases.
Veterinary Dermatology, 2020
Background-The genus Malassezia is comprised of a group of lipophilic yeasts that have evolved as skin commensals and opportunistic cutaneous pathogens of a variety of mammals and birds. Objectives-The objective of this document is to provide the veterinary community and other interested parties with current information on the ecology, pathophysiology, diagnosis, treatment and prevention of skin diseases associated with Malassezia yeasts in dogs and cats. Methods-The authors served as a Guideline Panel (GP) and reviewed the literature available prior to October 2018. The GP prepared a detailed literature review and made recommendations on selected topics. The World Association of Veterinary Dermatology (WAVD) Clinical Consensus Guideline committee provided guidance and oversight for this process. The document was presented at two international meetings of veterinary dermatology societies and one international mycology workshop; it was made available for comment on the WAVD website for a period of six months. Comments were shared with the GP electronically and responses incorporated into the final document. Conclusions and clinical importance-There has been a remarkable expansion of knowledge on Malassezia yeasts and their role in animal disease, particularly since the early 1990's. Malassezia dermatitis in dogs and cats has evolved from a disease of obscurity and controversy on its existence, to now being a routine diagnosis in general veterinary practice. Clinical signs are well-recognised and diagnostic approaches are well-developed. A range of topical and systemic therapies is known to be effective, especially when predisposing factors are identified and corrected. 1853 Charles Robin named Eichstedt's fungus as Microsporon furfur, believing it to be a dermatophyte, and termed the associated skin disease "Tinea versicolor". 39 1873 Sebastiano Rivolta, an Italian veterinarian, noticed a double-contour budding yeast in human "psoriatic" scales and gave them the name Cryptococcus psoriasis. 40 1874 Frenchman Louis Charles Malassez 41 suggested that Microsporon furfur caused dandruff and correctly differentiated the yeast into genus of single cell fungi ("Saccharomyces") rather than the dermatophyte complex. For this correction, his name was ultimately attached to the genus. 42 3.2.2. Attempts at classification without laboratory isolation 1884 Bizzozero studied these microbes and described them to be part of normal human skin flora. He claimed there were two different species and named them Saccharomyces ovalis and S. sphaericus. 43 However, these were later shown to be a single species. 44 1889 Baillon created the genus Malassezia to accommodate M. furfur, in honour of Malassez, who was already acknowledged as having described the new species-at least in the French-speaking scientific community. 17 However this particular yeast could not be grown and isolated in laboratory conditions because its lipid requirement in culture media were as yet unknown. 1910 Raymond Sabouraud, a prominent medical mycologist, proposed the name Pityrosporum malassezi for this bottle shaped yeast thought to cause human dandruff. 45 1913 Alfred Kraus was able to culture P. malassezi in a medium containing lanolin. 46 In a prime example of the effect of geography and historical events on scientific discovery, this German scientist's work was largely overlooked with the onset of the First World War. 3.2.3. Diseases associated with Malassezia 3.2.4. The controversy and 'Dark Years': 1940 to 1960 1940-1960 are known as the 'Dark Years' and spanned a period of more controversy. The hard won progress in the field was forgotten as a consequence of the Second World War and the overwhelming effect of cortisone treatment becoming available in the late 1940s, to which human seborrhoeic dermatitis responded. The role of Malassezia yeasts in the disease was thus forgotten. 1970 The systematics were rectified when Sloff in Lodder's 'The Yeasts, a taxonomic study' assigned all Pityrosporum that grew on media without lipid enrichment as single species of P. pachydermatis. 52, 53 1984 The third edition of 'The Yeasts, a Taxonomic Study' (Yarrow and Ahearn) referred to the new genus Malassezia and confirmed that one species grew without lipid enrichment. 54 This was later officially added into the taxonomical order. 55 1990 A new species, Malassezia sympodialis was described 19 and by 1996 four new species were added to the genus. 20 This species was later isolated from a cat by Bond et al. in 1996. 56 3.2.5 Modern approaches Currently there are 18 different species of Malassezia. 35,57 The genus continues to expand and this is likely to continue as the classical 'bottom-up' microbiological approaches merge with organism-level genomics and community or 'systems-level meta-genomics'.
Malassezia infections: A medical conundrum
Journal of the American Academy of Dermatology, 2014
Malassezia yeasts have long been considered commensal fungi, unable to elicit significant damage. However, they have been associated with a diversity of cutaneous diseases, namely pityriasis versicolor, Malassezia folliculitis, seborrheic dermatitis, atopic dermatitis, psoriasis, and confluent and reticulate papillomatosis. Several hypotheses have been proposed to explain the pathogenic mechanisms of these fungi, but none have been confirmed. More recently, such organisms have been increasingly isolated from bloodstream infections raising serious concern about these fungi. Given the difficulty to culture these yeasts to proceed with speciation and antimicrobial susceptibility tests, such procedures are most often not performed and the cutaneous infections are treated empirically. The recurring nature of superficial skin infections and the potential threat of systemic infections raise the need of faster and more sensitive techniques to achieve isolation, identification, and antimicrobial susceptibility profile. This article reviews and discusses the latest available data concerning Malassezia infections and recent developments about diagnostic methods, virulence mechanisms, and susceptibility testing. ( J Am Acad Dermatol http:// dx.d Malassezia pathogenicity mechanisms and their relation to disease and clinical manifestations remain to be elucidated.
Occurrence of Malassezia species in healthy and dermatologically diseased dogs
Mycopathologia, 2004
The presence of Malassezia spp. yeasts was investigated in dermatological specimens of 224 dogs, 164 dermatologically diseased and 60 normal dogs. Subjects included in the study were of different breed, age, sex and habitat. Malassezia spp. positive cultures were obtained in 142 (63.4%) specimens: 67.6% from dermatologically diseased subjects and 51.6% from healthy dogs. Malassezia pachydermatis, either as a pure
BMC Dermatology, 2014
Background: The Malassezia yeasts which belong to the physiological microflora of human skin have also been implicated in several dermatological disorders, including pityriasis versicolor (PV), atopic dermatitis (AD), and psoriasis (PS). The Malassezia genus has repeatedly been revised and it now accommodates 14 species, all but one being lipid-dependent species. The traditional, phenotype-based identification schemes of Malassezia species are fraught with interpretative ambiguities and inconsistencies, and are thus increasingly being supplemented or replaced by DNA typing methods. The aim of this study was to explore the species composition of Malassezia microflora on the skin of healthy volunteers and patients with AD and PS. Methods: Species characterization was performed by conventional, culture-based methods and subsequently molecular techniques: PCR-RFLP and sequencing of the internal transcribed spacer (ITS) 1/2 regions and the D1/D2 domains of the 26S rRNA gene. The Chi-square test and Fisher's exact test were used for statistical analysis. Results: Malassezia sympodialis was the predominant species, having been cultured from 29 (82.9%) skin samples collected from 17 out of 18 subjects under the study. Whereas AD patients yielded exclusively M. sympodialis isolates, M. furfur isolates were observed only in PS patients. The isolation of M. sympodialis was statistically more frequent among AD patients and healthy volunteers than among PS patients (P < 0.03). Whether this mirrors any predilection of particular Malassezia species for certain clinical conditions needs to be further evaluated. The overall concordance between phenotypic and molecular methods was quite high (65%), with the discordant results being rather due to the presence of multiple species in a single culture (co-colonization) than true misidentification. All Malassezia isolates were susceptible to cyclopiroxolamine and azole drugs, with M. furfur isolates being somewhat more drug tolerant than other Malassezia species. Conclusions: This study provides an important insight into the species composition of Malassezia microbiota in human skin. The predominance of M. sympodialis in both normal and pathologic skin, contrasts with other European countries, reporting M. globosa and M. restricta as the most frequently isolated Malassezia species.
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.