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Frontiers in Cellular and Infection... 2020Lipophilic yeasts of the genus are important skin commensals and opportunistic skin pathogens in a variety of animals. The species was first isolated from the skin of... (Review)
Review
Lipophilic yeasts of the genus are important skin commensals and opportunistic skin pathogens in a variety of animals. The species was first isolated from the skin of a captive Indian rhinoceros with an exfoliative dermatitis in 1925, recognized as an important otic pathogen of dogs in the 1950's, and finally accepted, after several years of controversy, as a common cause of canine dermatitis in the 1990's. Since then, there has been considerable research into the biology of yeasts and their interaction with their animal hosts. In dogs and cats, is associated with ceruminous otitis externa and a "seborrhoeic" dermatitis, wherein pruritic, erythematous skin lesions, often with brown/black greasy, malodourous material matting hairs, preferentially develop in intertriginous areas. Skin disease is favored by folds, underlying hypersensitivity disorders, endocrinopathies, defects of cornification, and in cats, various visceral paraneoplastic syndromes. Diagnosis is based on detecting the yeast in compatible skin lesions, usually by cytology, and observing a clinical and mycological response to therapy. Treatment normally comprises topical or systemic azole therapy, often with miconazole-chlorhexidine shampoos or oral itraconazole or ketoconazole. Management of concurrent diseases is important to minimize relapses. Historically, wild-type isolates from dogs and cats were typically susceptible to azoles, with the exception of fluconazole, but emerging azole resistance in field strains has recently been associated with either mutations or quadruplication of the gene. These observations have prompted increased interest in alternative topical antifungal drugs, such as chlorhexidine, and various essential oils. Further clinical trials are awaited with interest.
Topics: Animals; Antifungal Agents; Cat Diseases; Cats; Dermatitis; Dog Diseases; Dogs; Drug Resistance, Multiple, Fungal; Malassezia; Skin; Zoonoses
PubMed: 32181160
DOI: 10.3389/fcimb.2020.00079 -
Annual Review of Microbiology Sep 2022Identified in the late nineteenth century as a single species residing on human skin, is now recognized as a diverse genus comprising 18 species inhabiting not only... (Review)
Review
Identified in the late nineteenth century as a single species residing on human skin, is now recognized as a diverse genus comprising 18 species inhabiting not only skin but human gut, hospital environments, and even deep-sea sponges. All cultivated species are lipid dependent, having lost genes for lipid synthesis and carbohydrate metabolism. The surging interest in results from development of tools to improve sampling, culture, identification, and genetic engineering, which has led to findings implicating it in numerous skin diseases, Crohn disease, and pancreatic cancer. However, it has become clear that plays a multifaceted role in human health, with mutualistic activity in atopic dermatitis and a preventive effect against other skin infections due to its potential to compete with skin pathogens such as Improved understanding of complex microbe-microbe and host-microbe interactions will be required to define 's role in human and animal health and disease so as to design targeted interventions.
Topics: Animals; Dermatitis, Atopic; Humans; Lipids; Malassezia; Skin; Symbiosis
PubMed: 36075093
DOI: 10.1146/annurev-micro-040820-010114 -
Medical Mycology Apr 2018Malassezia are lipid dependent basidiomycetous yeasts that inhabit the skin and mucosa of humans and other warm-blooded animals, and are a major component of the skin... (Review)
Review
Malassezia are lipid dependent basidiomycetous yeasts that inhabit the skin and mucosa of humans and other warm-blooded animals, and are a major component of the skin microbiome. They occur as skin commensals, but are also associated with various skin disorders and bloodstream infections. The genus currently comprises 17 species and has recently been assigned its own class, Malasseziomycetes. Importantly, multiple Malassezia species and/or genotypes may cause unique or similar pathologies and vary in their antifungal susceptibility. In addition to culture-based approaches, culture-independent methods have added to our understanding of Malassezia presence and abundance and their relationship to pathogenicity. Moreover, these novel approaches have suggested a much wider-spread presence, including other human body parts and even other ecosystems, but their role in these arenas requires further clarification. With recent successful transformation and genetic engineering of Malassezia, the role of specific genes in pathogenesis can now be studied. We suggest that characterizing the metabolic impact of Malassezia communities rather than species identification is key in elucidation of pathophysiological associations. Finally, the increasing availability of genome sequences may provide key information aiding faster diagnostics, and understanding of the biochemical mechanisms for Malassezia skin adaptation and the design of future drugs.
Topics: Animals; Antifungal Agents; Biodiversity; Dermatomycoses; Drug Resistance, Fungal; Ecology; Genes, Fungal; Genomics; Humans; Malassezia
PubMed: 29538738
DOI: 10.1093/mmy/myx134 -
Journal of Microbiology and... May 2021is the most abundant genus in the fungal microflora found on human skin, and it is associated with various skin diseases. Among the 18 different species of that have... (Review)
Review
is the most abundant genus in the fungal microflora found on human skin, and it is associated with various skin diseases. Among the 18 different species of that have been identified to date, and are the most predominant fungal species found on human skin. Several studies have suggested a possible link between and skin disorders. However, our knowledge on the physiology and pathogenesis of in human body is still limited. is unable to synthesize fatty acids; hence, it uptakes external fatty acids as a nutrient source for survival, a characteristic compensated by the secretion of lipases and degradation of sebum to produce and uptake external fatty acids. Although it has been reported that the activity of secreted lipases may contribute to pathogenesis of , majority of the data were indirect evidences; therefore, enzymes' role in the pathogenesis of infections is still largely unknown. This review focuses on the recent advances on in the context of an emerging interest for lipases and summarizes the existing knowledge on , diseases associated with the fungus, and the role of the reported lipases in its physiology and pathogenesis.
Topics: Dermatomycoses; Fungal Proteins; Humans; Lipase; Lipid Metabolism; Malassezia; Sebum; Skin; Virulence
PubMed: 33526754
DOI: 10.4014/jmb.2012.12048 -
Current Opinion in Microbiology Dec 2017The skin is our first line of defense, protecting us from invasion and evaporation. Its variable structure, changing geography, and complex immune repertoire provide a... (Review)
Review
The skin is our first line of defense, protecting us from invasion and evaporation. Its variable structure, changing geography, and complex immune repertoire provide a vast interface for our cutaneous microbial community. Skin is inhabited by many thousands of microbes, but this review focuses on the dominant eukaryote, Malassezia, and its host interaction. Malassezia compromises 17 species with variable niche specificities and differing pathogenic potential. It has been known as a skin inhabitant for over 100 years, and is now accepted to be on all warm-blooded animals. Malassezia occupy healthy and diseased skin, so their role as commensal or pathogenic organisms is complex. Malassezia interact with their host indirectly through immune interplay and directly via chemical mediators. While some interactions are known, many remain to be fully understood.
Topics: Animals; Dermatomycoses; Host-Pathogen Interactions; Humans; Malassezia; Skin; Skin Diseases, Bacterial
PubMed: 29141240
DOI: 10.1016/j.mib.2017.10.024 -
The Journal of Dermatology Nov 2018Malassezia are lipophilic and commensal yeasts capable of inducing skin disease among susceptible hosts. However, severely immunocompromised patients and preterm infants... (Review)
Review
Malassezia are lipophilic and commensal yeasts capable of inducing skin disease among susceptible hosts. However, severely immunocompromised patients and preterm infants admitted to intensive care units are particularly at risk of developing Malassezia systemic infections. Patients often have central venous catheters which are usually the portal of entry for colonization and infection. In addition to the clinically non-specific findings, a delay in the laboratorial diagnosis may occur as there is often the need to add lipid supplementation to culture in order to support these organisms' growth. Herein, we report three unrelated cases of Malassezia bloodstream infection at a university hospital during a 2-year period, followed by a discussion of the clinical results and comparison with the most recently available published data on epidemiology and risk factors, pathogenesis, diagnosis, susceptibility profile and treatment.
Topics: Aged; Antifungal Agents; Catheter-Related Infections; Central Venous Catheters; Child, Preschool; Dermatomycoses; Female; Humans; Immunocompromised Host; Infant, Newborn; Infant, Premature; Invasive Fungal Infections; Lipid Metabolism; Malassezia; Male; Middle Aged; Skin; Treatment Outcome
PubMed: 30264900
DOI: 10.1111/1346-8138.14653 -
Frontiers in Cellular and Infection... 2020is the most prevalent fungus identified in the human skin microbiota; originally described at the end of the nineteenth century, this genus is composed of at least 14... (Review)
Review
is the most prevalent fungus identified in the human skin microbiota; originally described at the end of the nineteenth century, this genus is composed of at least 14 species. The role of on the skin remains controversial because this genus has been associated with both healthy skin and pathologies (dermatitis, eczema, etc.). However, with the recent development of next-generation sequencing methods, allowing the description of the fungal diversity of various microbiota, has also been identified as a resident fungus of diverse niches such as the gut or breast milk. A potential role for in gut inflammation and cancer has also been suggested by recent studies. The aim of this review is to describe the findings on in these unusual niches, to investigate what is known of the adaptation of to the gut environment and to speculate on the role of this yeast in the host physiology specifically related to the gastrointestinal tract.
Topics: Female; Fungi; Humans; Malassezia; Microbiota; Milk, Human; Skin
PubMed: 32528901
DOI: 10.3389/fcimb.2020.00201 -
Current Opinion in Infectious Diseases Apr 2002Since the taxonomic revision carried out in 1996, enlarging the genus Malassezia to comprise seven different species, a number of studies have investigated from... (Review)
Review
Since the taxonomic revision carried out in 1996, enlarging the genus Malassezia to comprise seven different species, a number of studies have investigated from different points of view -- mycological, molecular and immunological -- the relationships of these species with the pathologies associated with lipophilic yeasts, as well as its presence in healthy skin. From these studies, it now appears clear that Malassezia globosa is the main species associated with pityriasis versicolor, which is the only cutaneous disease in which the involvement of Malassezia is undisputed. Nevertheless, this species can also be found in normal skin, in which the predominant species is Malassezia sympodialis. In the remaining dermatological disorders related to Malassezia, the role of these yeasts is controversial. In seborrhoeic dermatitis, atopic dermatitis and folliculitis, several studies have focused on the immunological aspects that could explain the pathogenic mechanism. In other diseases, such as confluent and reticulate papillomatosis, neonatal pustulosis, otitis and onychomycosis, the presence or significance of Malassezia is still a matter of dispute.
Topics: Dermatomycoses; Humans; Malassezia; Onychomycosis; Otitis; Papilloma; Skin Diseases
PubMed: 11964913
DOI: 10.1097/00001432-200204000-00006 -
Folia Medica 2009Malassezia spp. are medically important dimorphic, lipophilic yeasts that form part of the normal cutaneous microflora of human. Seborrheic dermatitis is a multifactor... (Review)
Review
Malassezia spp. are medically important dimorphic, lipophilic yeasts that form part of the normal cutaneous microflora of human. Seborrheic dermatitis is a multifactor disease that needs endogenous and exogenous predisposing factors for its development. Presence of these factors leads to reproduction of the saprophytic opportunistic pathogen Malassezia spp. and development of a disease. The inflammatory reaction against the yeast Malassezia is considered basic in the etiology of the seborrheic dermatitis. The pathogenesis and exact mechanisms via which these yeasts cause inflammation are still not fully elucidated. They are rather complex and subject of controversy in literature. Most probably Malassezia spp. cause seborrheic dermatitis by involving and combining both nonummune and immune mechanisms (nonspecific and specific). Which of these mechanisms will dominate in any single case depends on the number and virulence of the yeasts as well as on the microorganism reactivity. In the recent years a great interest have been aroused by the epidemiological investigations. Depending on the geographical place of the countries different Malassezia species in seborrheic dermatitis dominate in the different countries. In view of the etiology and pathogenesis of the seborrheic dermatitis comprehensive antifungal preparations have been recently introduced and are nowadays the basic therapeutic resource in the treatment of this disease.
Topics: Antibody Formation; Antifungal Agents; Dermatitis, Seborrheic; Humans; Immunity, Cellular; Malassezia; Skin; Virulence
PubMed: 19437895
DOI: No ID Found -
Revista Iberoamericana de Micologia 2020
Review
Topics: Animals; Biodiversity; Body Temperature; Chiroptera; Hibernation; Host Adaptation; Malassezia; Species Specificity
PubMed: 31937426
DOI: 10.1016/j.riam.2019.12.001