A study of the fatty acid metabolism of the yeast <i>Pityrosporum ovale</i>

Wilde, Peter F.; Stewart, Patrick D. Shaw

doi:10.1042/bj1080225

Cited by 58 publications

(28 citation statements)

References 6 publications

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“…The lipid source used during growth affects the fatty acid composition of the organism, suggesting that the fatty acids are not used as energy sources but, rather, are incorporated directly into cellular lipids without being further metabolized (80). Wilde and Stewart further found that the lipids present on normal human scalps were able to fulfil the lipid requirement of the organism (469).…”

Section: Structure Physiology and Biochemistrymentioning

confidence: 99%

“…Subsequent work showed that the addition of most fatty acids with a carbon chain length greater than 10 supported growth and that it did not matter whether odd-or even-numbered carbon chain lengths were used (469). The lipid source used during growth affects the fatty acid composition of the organism, suggesting that the fatty acids are not used as energy sources but, rather, are incorporated directly into cellular lipids without being further metabolized (80).…”

Section: Structure Physiology and Biochemistrymentioning

confidence: 99%

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Immunology of Diseases Associated withMalasseziaSpecies

2002

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SUMMARY 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.

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Section: Structure Physiology and Biochemistrymentioning

confidence: 99%

Section: Structure Physiology and Biochemistrymentioning

confidence: 99%

Immunology of Diseases Associated withMalasseziaSpecies

2002

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“…A number of studies have described the specific fatty acid requirements and lipid metabolism of M. furfur (100,129,146). These studies demonstrated that in vitro growth occurs only in the presence of long-chain fatty acids from the C12 to C24 series.…”

Section: Macroscopic and Microscopic Morphologymentioning

confidence: 99%

Human infections due to Malassezia spp

1992

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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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“…On the basis of data available for nutrition and culture media of Pityrosporum (2,3,5,6,13,15,17,19,20,22), we designed culture media which enabled lux-uriant growth of each species of Pityrosporum, and also selective and differential media by the addition of appropriate selective agents.…”

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confidence: 99%

Selective and Differential Media for Isolation and Tentative Identification of Each Species of Pityrosporum Residing on Normal or Diseased Human Skin

Ushijima

Takahashi

Ozaki

1981

Microbiology and Immunology

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Selective and differential media were designed for each species of Pityrosporum ; P. pachydermatis, P. ouale, and P. orbiculare in order to make feasible a quantitative cultivation.Medium for P. pachydermatis (medium A) was composed of 1% trypticase peptone (BBL), 0.5% yeast extract (BBL), 0.3% glucose, 0.2% NaCl, 1.2% KH2 P04 (anhydrous), 1.5% agar, 0.01% ampicillin, and 0.025% cycloheximide with a pH of 5.5. Medium for P. ouale (medium B) was medium A supplemented with 0.05% sodium acetate (anhydrous), 0.2% Tween 80, and 0.025% (selective medium) or 0.075% (differential medium) sodium laurate. Medium for P. orbiculare was medium B (devoid of laurate) supplemented with 2% olive oil, 0.25% glycerol, 0.25% gall powder, 0.05% sodium palmitate, 0.05% sodium stearate, 0.05% sodium oleate and 8% (selective medium) or 10% (differential medium) sodium lactate and an increase in Tween to 1%.For isolation of Pityrosporum, specimens were suspended in 0.1% Tween 80 solution and inoculated onto agar plates of three selective media. The plates were incubated aerobically at 37 C for 8-10 days under conditions of prevention of water loss from the media. The plating efficiency of each selective medium, expressed as a ratio of cultural counts to microscopic counts was generally over 70%. Species of Pityrosporum could also be identified when we inoculated the cell suspension onto differential agar plates and incubated the preparations at 37 C for 7 days.

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A study of the fatty acid metabolism of the yeast Pityrosporum ovale

Cited by 58 publications

References 6 publications

Immunology of Diseases Associated withMalasseziaSpecies

Immunology of Diseases Associated withMalasseziaSpecies

Human infections due to Malassezia spp

Selective and Differential Media for Isolation and Tentative Identification of Each Species of Pityrosporum Residing on Normal or Diseased Human Skin

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