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Query: UMLS:C0243026 (sepsis)
 52,417 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The genus Malassezia contains three member species: Malassezia furfur and Malassezia sympodialis, both obligatory lipophilic, skin flora yeasts of humans, and Malassezia pachydermatis, a nonobligatory lipophilic, skin flora yeast of other warm-blooded animals. Several characteristics suggest the basidiomycetous nature of these yeasts, although a perfect stage has not been identified. Classically, these organisms are associated with superficial infections of the skin and associated structures, including pityriasis versicolor and folliculitis. Recently, however, they have been reported as agents of more invasive human diseases including deep-line catheter-associated sepsis. The latter infection occurs in patients, primarily infants, receiving parenteral nutrition (including lipid emulsions) through the catheter. The lipids presumably provide growth factors required for replication of the organisms. It is unclear how deep-line catheters become colonized with Malassezia spp. Skin colonization with M. furfur is common in infants hospitalized in neonatal intensive care units, whereas colonization of newborns hospitalized in well-baby nurseries and of older infants is rarely observed. Catheter colonization, which may occur without overt clinical symptoms, probably occurs secondary to skin colonization, with the organism gaining access either via the catheter insertion site on the skin or through the external catheter hub (connecting port). There is little information on the colonization of hospitalized patients by M. sympodialis or M. pachydermatis. Diagnosis of superficial infections is best made by microscopic examination of skin scrapings following KOH, calcofluor white, or histologic staining. Treatment of these infections involves the use of topical or oral antifungal agents, and it may be prolonged. Diagnosis of Malassezia catheter-associated sepsis requires detection of the organism in whole blood smears or in buffy coat smears of blood drawn through the infected catheter or isolation of the organism from catheter or peripheral blood or the catheter tip. Culture of M. furfur from blood is best achieved with Isolator tubes and plating onto a solid medium supplemented with a lipid source. Appropriate treatment of patients requires removal of the infected catheter with or without temporary stoppage of lipid emulsions; administration of antifungal therapeutic agents does not appear to be necessary. Because many patients who develop Malassezia catheter-associated sepsis have severe underlying illnesses, caution must be exercised in attributing all clinical deterioration to Malassezia infection. Our better understanding of how these organisms cause disease awaits the development of a useful typing scheme for epidemiologic studies and further studies on microbial virulence factors and the role of the immune response in pathogenesis.
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PMID:Human infections due to Malassezia spp. 157 83

Malassezia furfur is a saprophytic fungus that is part of the normal cutaneous microflora of adults. It frequently causes tinea versicolor and less often, a distinctive folliculitis. In infants and occasionally in adults the fungus is associated with a sepsis syndrome that heralds a deep-seated infection. These entities, their diagnosis, and their treatment are discussed.
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PMID:Malassezia furfur. 264 34

Until recently, Malassezia furfur was thought to be a pathogen only in tinea versicolor. More recently, this lipophilic yeast has been recovered from sick neonates with catheter-related infections. Malassezia fungemia was studied in seven patients, and the salient features of this infection in patients described in the literature were reviewed. Major risk factors include prolonged hospitalization, the presence of central venous catheters, and the use of intravenous fat emulsions. It is difficult to identify specific manifestations of fungemia in these complex cases occurring in patients with severe underlying disease; however, neonates often present with the signs and symptoms of sepsis and thrombocytopenia, whereas fever may be the only manifestation in adults. Some patients are asymptomatic. When symptoms are present, they resolve upon removal of the colonized catheter. The role of the lipophilic nature of Malassezia in the pathogenesis of infection is apparent from the ability of intravenous fat emulsions to support the growth of the fungus in vitro. A special solid medium that can be used to determine the true prevalence of malassezia fungemia has been devised. M. furfur must be considered in the differential diagnosis of opportunistic infections in patients receiving central hyperalimentation and should be sought by the culture of blood on appropriate medium.
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PMID:Malassezia fungemia in neonates and adults: complication of hyperalimentation. 312 78

Malassezia furfur (Pityrosporum orbiculare, P ovale), a lipophilic yeast that is part of the normal skin flora, causes tinea versicolor but has only rarely been associated with more serious infections. We report five episodes in four infants of catheter-related infection caused by this organism. All episodes occurred in infants who had survived serious neonatal disorders and were receiving prolonged therapy with intravenous fat emulsion. Sudden onset of fever without focal findings was the usual presentation; however, one afebrile patient had recurrent episodes of apnea, bradycardia, and cyanosis. Thrombocytopenia was a prominent finding. Patients were generally treated with amphotericin B. All patients recovered when the colonized catheter was removed or fat emulsion therapy was stopped. The yeast usually grew slowly in blood culture media but grew readily when subcultured onto Sabouraud's medium coated with sterile olive oil. Yeasts were readily identified in all four patients in whom a buffy coat Gram stain was obtained of blood from the central intravenous catheter. M furfur may be a fairly common but unrecognized cause of catheter-related sepsis in infants receiving long-term fat emulsion therapy. This organism should be sought whenever routine blood cultures are negative for bacteria and yeasts are observed in a buffy coat Gram stain.
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PMID:Catheter-related infection in infants due to an unusual lipophilic yeast--Malassezia furfur. 393 37

Pityrosporum ovale is a lipophilic yeast that is part of the normal human adult cutaneous flora. It is both a saprophyte and an opportunistic pathogen associated with pityriasis versicolor, Pityrosporum folliculitis, seborrheic dermatitis, and some forms of atopic dermatitis. Systemic infections have also been described. In this article the diagnosis and management of pityriasis versicolor, Pityrosporum folliculitis, seborrheic dermatitis, and atopic dermatitis will be discussed.
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PMID:Pityrosporum infections. 807 1

Malassezia furfur is a lipophilic yeast considered as a normal component of the human skin flora. Apart from pityriasis versicolor, M. furfur has been linked to several skin diseases such as seborrheic dermatitis, folliculitis or atopic dermatitis. Moreover, these yeasts have been reported as agent of invasive human diseases including pneumonia, catheter-associated sepsis and peritonitis. The existence of morphological, serological, metabolical, biochemical and karyotipical differences has been described among isolates of these yeasts. These observations gave arguments for a possible intraspecific division, and this hypothesis has been confirmed by the existence of six species within the formerly called M. furfur (lipid-dependent Malassezia strains): M. furfur, Malassezia sympodialis, Malassezia globosa, Malassezia obtusa, Malassezia restricta and Malassezia slooffiae.
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PMID:[Taxonomy of Malassezia furfur: state of the art]. 1553 15

Mincle (also called as Clec4e and Clecsf9) is a C-type lectin receptor expressed in activated phagocytes. Recently, we have demonstrated that Mincle is an FcRgamma-associated activating receptor that senses damaged cells. To search an exogenous ligand(s), we screened pathogenic fungi using cell line expressing Mincle, FcRgamma, and NFAT-GFP reporter. We found that Mincle specifically recognizes the Malassezia species among 50 different fungal species tested. Malassezia is a pathogenic fungus that causes skin diseases, such as tinea versicolor and atopic dermatitis, and fatal sepsis. However, the specific receptor on host cells has not been identified. Mutation of the putative mannose-binding motif within C-type lectin domain of Mincle abrogated Malassezia recognition. Analyses of glycoconjugate microarray revealed that Mincle selectively binds to alpha-mannose but not mannan. Thus, Mincle may recognize specific geometry of alpha-mannosyl residues on Malassezia species and use this to distinguish them from other fungi. Malassezia activated macrophages to produce inflammatory cytokines/chemokines. To elucidate the physiological function of Mincle, Mincle-deficient mice were established. Malassezia-induced cytokine/chemokine production by macrophages from Mincle(-/-) mice was significantly impaired. In vivo inflammatory responses against Malassezia was also impaired in Mincle(-/-) mice. These results indicate that Mincle is the first specific receptor for Malassezia species to be reported and plays a crucial role in immune responses to this fungus.
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PMID:C-type lectin Mincle is an activating receptor for pathogenic fungus, Malassezia. 1917 87

In the last 15 years, the genus Malassezia has been a topic of intense basic research on taxonomy, physiology, biochemistry, ecology, immunology, and metabolomics. Currently, the genus encompasses 14 species. The 1996 revision of the genus resulted in seven accepted taxa: M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. restricta, and M. slooffiae. In the last decade, seven new taxa isolated from healthy and lesional human and animal skin have been accepted: M. dermatis, M. japonica, M. yamatoensis, M. nana, M. caprae, M. equina, and M. cuniculi. However, forthcoming multidisciplinary research is expected to show the etiopathological relationships between these new species and skin diseases. Hitherto, basic and clinical research has established etiological links between Malassezia yeasts, pityriasis versicolor, and sepsis of neonates and immunocompromised individuals. Their role in aggravating seborrheic dermatitis, dandruff, folliculitis, and onychomycosis, though often supported by histopathological evidence and favorable antifungal therapeutic outcomes, remains under investigation. A close association between skin and Malassezia IgE binding allergens in atopic eczema has been shown, while laboratory data support a role in psoriasis exacerbations. Finally, metabolomic research resulted in the proposal of a hypothesis on the contribution of Malassezia-synthesized aryl hydrocarbon receptor (AhR) ligands to basal cell carcinoma through UV radiation-induced carcinogenesis.
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PMID:The Malassezia genus in skin and systemic diseases. 2223 73

Malassezia species (formerly known as Pityrosporum) are part of normal human skin flora and have been associated with benign dermatologic conditions, such as seborrheic dermatitis and tinea versicolor. In rare cases, however, Malassezia has been associated with systemic disease in immunocompromised patients and infants in the neonatal intensive care unit. Malassezia species require long-chain fatty acids for growth and therefore have a known predilection for individuals receiving lipid containing intravenous parenteral nutrition (PN). Systemic infections are characterized by prolonged fevers and illness but can include nonspecific signs and symptoms. We present the diagnosis and management of a rare case of an immunocompetent, nonneonatal, PN-dependent child with Malassezia furfur pneumonia.
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PMID:Malassezia Pneumonia: A Rare Complication of Parenteral Nutrition Therapy. 2615 Apr 10