Malassezia and the Skin (eBook)

156722_1_En_BookFrontmatter_OnlinePDF 2
156722_1_En_1_Chapter_OnlinePDF 10
1 10
Introduction: .Malassezia. Yeasts from a Historical Perspective 10
1.1 .Definition 11
1.2 .Taxonomy 11
1.3 .Culture Studies 13
1.4 .Ecology 15
1.5 .Associated Diseases 15
1.5.1 .Pityriasis Versicolor (PV) 16
1.5.2 .Seborrhoeic Dermatitis (SD) 17
1.5.3 ..Malassezia. Folliculitis 18
1.5.4 ....Atopic Dermatitis (AD) 18
1.5.5 .Confluent and Reticulate Papillomatosis 19
1.5.6 .Other Conditions 19
1.5.7 .Systemic Infection 19
1.6 .Perspectives 19
1.7 .Currently Recognised Species 20
References 20
156722_1_En_2_Chapter_OnlinePDF 26
2 26
Biodiversity, Phylogeny and Ultrastructure 26
2.1 .Isolation, Identification and Biodiversity of .Malassezia. Yeasts 27
2.1.1 .Isolation of .Malassezia. Yeasts from Humans and Animals and their Maintenance 27
2.1.1.1 .Isolation 30
2.1.1.1.1 .Methods 30
2.1.1.1.2 .Selective Media 30
2.1.1.1.3 .Remarks 31
2.1.1.2 .Maintenance of Cultures 31
2.1.2 .Identification of ..Malassezia.. Yeasts Using Routine Laboratory Methods 32
2.1.2.1 .Characterization of Urease Activity Using Bacto Urea Broth 32
2.1.2.1.1 .Method 32
2.1.2.1.2 .Medium 33
2.1.2.1.3 .Remark 33
2.1.2.2 .Characterization of the Catalase Activity Using Hydrogen Peroxide 33
2.1.2.2.1 .Method 33
2.1.2.2.2 .Reagent 33
2.1.2.3 .Characterization of .b.-Glucosidase Activity Using the Esculin Medium 33
2.1.2.3.1 .Method 34
2.1.2.3.2 .Media 34
2.1.2.3.3 .Remarks 34
2.1.2.4 .Growth at 37°C and 40°C 34
2.1.2.4.1 .Remark 34
2.1.2.5 .Utilization of Tweens 20, 40, 60, 80, and Cremophor EL (see Scheme .2.1. and Plates .2.1. and .2.2.) 35
2.1.2.5.1 .Methods 35
2.1.2.5.2 .Medium 36
2.1.2.5.3 .Remarks 36
2.1.3 .Biodiversity of .Malassezia. Yeasts 37
2.1.3.1 ..Malassezia pachydermatis. (Weidman) Dodge (1925) 37
2.1.3.1.1 .Neotype Strain 37
2.1.3.1.2 .Morphological Characteristics 37
2.1.3.1.3 .Physiological and Biochemical Characteristics 39
2.1.3.1.4 .Ecology 39
2.1.3.2 ..Malassezia furfur. (Robin) Baillon (1889) 39
2.1.3.2.1 .Neotype Strain 39
2.1.3.2.2 .Morphological Characteristics 40
2.1.3.2.3 .Physiological and Biochemical Characteristics 41
2.1.3.2.4 .Ecology 41
2.1.3.3 ..Malassezia yamatoensis Sugita, Tajima, Takashima, Amaya, Saito, Tsuboi & Nishikawa (2004)
2.1.3.3.1 .Type Strain 42
2.1.3.3.2 .Morphological Characteristics 42
2.1.3.3.3 .Physiological and Biochemical Characteristics 43
2.1.3.3.4 .Ecology 43
2.1.3.4 ..Malassezia sympodialis. Simmons & Guého (1990)
2.1.3.4.1 .Type Strain 43
2.1.3.4.2 .Morphological Characteristics 43
2.1.3.4.3 .Physiological and Biochemical Characteristics 45
2.1.3.4.4 .Ecology 45
2.1.3.5 ...Malassezia caprae.. ...Cabañes & Boekhout (2007)
2.1.3.5.1 .Type Strain 45
2.1.3.5.2 .Morphological Characteristics 45
2.1.3.5.3 .Physiological and Biochemical Characteristics 46
2.1.3.5.4 .Ecology 46
2.1.3.6 ..Malassezia dermatis. Sugita, Takashima, Nishikawa & Shinoda (2002)
2.1.3.6.1 .Type Strain 47
2.1.3.6.2 .Morphological Characteristics 47
2.1.3.6.3 .Physiological and Biochemical Characteristics 48
2.1.3.6.4 .Ecology 48
2.1.3.7 ..Malassezia slooffiae. ...Guillot, Midgley & Guého (1996)
2.1.3.7.1 .Type Strain 48
2.1.3.7.2 .Morphological Characteristics 48
2.1.3.7.3 .Physiological and Biochemical Characteristics 49
2.1.3.7.4 .Ecology 49
2.1.3.8 ..Malassezia japonica. Sugita, Takashima, Kodama, Tsuboi & Nishikawa (2003)
2.1.3.8.1 .Type Strain 50
2.1.3.8.2 .Morphological Characteristics 50
2.1.3.8.3 .Physiological and Biochemical Characteristics 51
2.1.3.8.4 .Ecology 51
2.1.3.9 ..Malassezia nana. Hirai, Kano, Makimura, Yamaguchi & Hasegawa (2004)
2.1.3.9.1 .Type Strain 51
2.1.3.9.2 .Morphological Characteristics 51
2.1.3.9.3 .Physiological Characteristics 52
2.1.3.9.4 .Ecology 53
2.1.3.10 ...Malassezia equina.. Cabañes & Boekhout (2007)
2.1.3.10.1 .Type Strain 53
2.1.3.10.2 .Morphological Characteristics 53
2.1.3.10.3 .Physiological and Biochemical Characteristics 53
2.1.3.10.4 .Ecology 54
2.1.3.11 ..Malassezia obtusa. ...Midgley, Guillot & Guého (1996)
2.1.3.11.1 .Type Strain 54
2.1.3.11.2 .Morphological Characteristics 55
2.1.3.11.3 .Physiological and Biochemical Characteristics 55
2.1.3.11.4 .Ecology 56
2.1.3.12 ..Malassezia globosa. Midgley, Guého & Guillot (1996)
2.1.3.12.1 .Type Strain 56
2.1.3.12.2 .Morphological Characteristics 56
2.1.3.12.3 .Physiological and Biochemical Characteristics 57
2.1.3.12.4 .Ecology 58
2.1.3.13 ..Malassezia restricta. Guého, Guillot & Midgley (1996)
2.1.3.13.1 .Type Strain 58
2.1.3.13.2 .Morphological Characteristics 58
2.1.3.13.3 .Physiological and Biochemical Characteristics 59
2.1.3.13.4 .Ecology 60
2.2 ..Malassezia. Phylogeny 60
2.3 ..Malassezia. Ultrastructure 64
2.3.1 .Cell Wall Ultra-Structure 64
2.3.2 .Budding Process Ultra-Structure and Endosporulation 66
2.3.3 .Other Ultrastructural Characteristics 66
References 68
156722_1_En_3_Chapter_OnlinePDF 73
3 73
Epidemiology of .Malassezia.-Related Skin Diseases 73
3.1 .Molecular detection and Identification of .Malassezia. yeasts in the Epidemiological Studies 73
3.1.1 .Introduction 73
3.1.2 .Biotyping 74
3.1.3 .Electrophoretic Karyotyping 74
3.1.4 .PCR-Based Methods 75
3.1.4.1 .Random Amplification of Polymorphic DNA (RAPD) and DNA Fingerprinting 76
3.1.4.2 .Restriction Fragment Length Polymorphism (RFLP) Analysis 77
3.1.4.3 .Amplified Fragment Length Polymorphism (AFLP.TM.) analysis 78
3.1.4.4 ..Terminal. Fragment Length Polymorphism (.t.FLP) Analysis 79
3.1.4.5 .Denaturing gradient gel electrophoresis (DGGE) and single strand conformation polymorphism (SSCP) analysis 80
3.1.4.6 .Detection by Luminex Technology 81
3.1.4.7 .Epidemiological Investigations by Real-time PCR 81
3.1.5 .DNA Sequence Analysis 84
3.1.5.1 .Ribosomal DNA Sequences 84
3.1.5.2 .Other Genes 87
3.1.6 .Skin Community Analysis and Environmental Samples 88
3.1.7 .Other Methods 89
3.2 .Human Epidemiology 89
3.2.1 .Introduction 89
3.2.2 ..Malassezia. in Healthy Individuals 90
3.2.3 ..Malassezia.-Related Skin Diseases 93
3.3 .Animal epidemiology 102
3.3.1 .Introduction 102
3.3.2 .Occurrence and Distribution of .Malassezia. Yeasts in Animals 102
3.3.2.1 .Animals in Zoological Parks or in Wildlife 102
3.3.2.2 .Domestic Carnivores 107
3.3.2.3 .Domestic Herbivores 109
3.3.2.4 .Swine 110
3.3.2.5 .Rodents and Lagomorphs 110
3.3.2.6 .Distribution Within a Single Animal Host 110
3.3.3 .Factors Associated with Increased .Malassezia. Populations in Animals 113
3.3.3.1 .Factors Related to the Animal Hosts 113
3.3.3.2 .Factors Related to the Skin Microenvironment 115
3.3.3.3 .Factors Related to .Malassezia. Species and Isolates 116
3.4 .Conclusions 117
References 118
156722_1_En_4_Chapter_OnlinePDF 128
4 128
Physiology and Biochemistry 128
4.1 .Nutritional Requirements 129
4.1.1 .Lipid Metabolism 129
4.1.2 .General Metabolism 129
4.2 .Cellular Wall 130
4.3 .Production of Filaments 130
4.4 .Enzymatic Activities 130
4.4.1 .Lipase 131
4.4.2 .Lipoxygenase 132
4.4.3 .Azelaic Acid 132
4.4.4 .Gamma-Lactone 132
4.4.5 .Phospholipase 132
4.5 .Production of Pigments 133
4.5.1 .Melanin 133
4.5.2 .Tryptophan-Derived Indole Pigments 134
4.6 .New Findings on the Biosynthesis of .Malassezia. Compounds 138
References 140
156722_1_En_5_Chapter_OnlinePDF 145
5 145
Malassezia. Species and Immunity: Host–.Pathogen Interactions 145
5.1 .Introduction 145
5.2 .The Skin Immune System 146
5.3 .Innate Immune Responses to .Malassezia 148
5.3.1 .Complement System 148
5.3.2 .Anti-microbial Peptides 149
5.3.3 .Transferrin 149
5.3.4 .Cellular Responses and Cytokine Production 150
5.3.5 .Interaction of .Malassezia. spp. with Cutaneous Cells 152
5.3.5.1 .Infiltrates Within .Malassezia-.Associated Diseases 152
5.3.5.2 .Interaction with Melanocytes 153
5.3.5.3 .Interaction with Keratinocytes 154
5.3.5.4 .Adherence to Human Keratinocytes 154
5.3.5.5 .Adherence of .Malassezia pachydermatis. to Canine Stratum Corneum Cells 155
5.3.5.6 .Malassezia pachydermatis Adherence in Canine Malassezia dermatitis 156
5.3.5.7 .Cytokine Production by Keratinocytes in Response to .Malassezia 157
5.3.5.8 .Interaction with Dermal Fibroblasts 159
5.4 .Adaptive Immune Responses to .Malassezia 159
5.4.1 .Humoral Responses in Humans 159
5.4.2 .Humoral Responses in Dogs 162
5.4.3 .Cellular Responses in Humans 163
5.4.3.1 .Healthy Individuals 164
5.4.3.2 .Pityriasis Versicolor 165
5.4.3.3 .Seborrhoeic Dermatitis 166
5.4.3.4 .Psoriasis 167
5.4.4 .Cellular Responses in Dogs 167
5.5 .Models for .Malassezi.a-Associated Diseases 168
5.5.1 .Normal Skin 168
5.5.2 .Pityriasis Versicolor 168
5.5.3 .Seborrhoeic Dermatitis 169
5.5.4 .Psoriasis 169
5.5.5 ..Malassezia pachydermatis. Otitis and Dermatitis in Dogs 169
5.6 .Conclusions 170
References 171
156722_1_En_6_Chapter_OnlinePDF 180
6 180
Pityriasis Versicolor and Other.Malassezia. Skin Diseases 180
6.1 .Pityriasis Versicolor 181
6.1.1 .Introduction 181
6.1.2 .Epidemiology 181
6.1.3 .Etiology and Pathogenesis 183
6.1.4 .Clinical Presentation 186
6.1.5 .Differential Diagnosis 188
6.1.6 .Mycological Diagnosis 189
6.1.7 .Treatment 190
6.1.8 .Relapse and Prevention 191
6.2 .Association with Other Skin Diseases 191
6.2.1 ..Malassezia. (.Pityrosporum.) Folliculitis 191
6.2.2 .Confluent and Reticulate Papillomatosis of Gougerot-Carteaud 193
6.2.3 .Neonatal Cephalic Pustulosis 194
6.2.4 .Otitis 196
6.2.5 .Onychomycosis 196
6.2.6 .Balanitis 196
6.2.7 .Keratitis 197
6.2.8 .Psoriasis 198
References 199
156722_1_En_7_Chapter_OnlinePDF 205
7 205
Malassezia. Yeasts in Seborrheic and Atopic Eczemas 205
7.1 .Seborrheic Eczema/Dermatitis 206
7.1.1 .Definition 206
7.1.2 .Seborrheic Eczema Clinical Morphology 207
7.1.3 .Seborrheic Eczema and .Malassezia 208
7.1.4 .Seborrheic Eczema and HIV/AIDS 211
7.1.5 .Infantile Seborrheic Eczema 211
7.1.6 .Therapy 212
7.1.6.1 .Antifungals 212
7.1.6.2 .Topical Corticosteroids 213
7.1.6.3 .Selenium Sulfide Preparations 214
7.1.6.4 .Topical Lithium Salts 214
7.1.6.5 .Topical Calcineurin Inhibitors 214
7.1.6.6 .Phototherapy 215
7.1.6.7 .Systemic Antifungal Therapy 215
7.2 ..Malassezia. in Atopic Eczema/Dermatitis 216
7.2.1 .Atopic Eczema (Atopic Dermatitis) 216
7.2.2 ..Malassezia. and Atopic Eczema 217
7.2.3 .Microbe and Allergen Interaction with Our Immune System 217
7.2.4 .Allergens in .Malassezia. Species 218
7.2.5 .Host–Microbe Interactions in AE 220
7.2.6 .Cross-Reactivity Between .Malassezia. Allergens and Self-Proteins 221
7.2.7 .Diagnosis of Sensitization to .Malassezia 223
7.2.8 .Future Therapy 223
7.2.9 .Conclusions 224
References 224
156722_1_En_8_Chapter_OnlinePDF 233
8 233
Malassezia. Fungemia, Antifungal Susceptibility Testing and Epidemiology of Nosocomial Infections 233
8.1 ..Malassezia. Fungemia and Invasive Infections 233
8.1.1 .Epidemiology and Risk Factors 234
8.1.2 .Host–Pathogen Interactions 236
8.1.3 .Pathogenesis of Invasive Infections 236
8.1.4 .Clinical Manifestations 237
8.1.5 .Laboratory Diagnosis 238
8.1.6 .Clinical Management 238
8.1.7 .Outcome 239
8.2 .Antifungal Susceptibility Testing 240
8.2.1 .Rationale for .Malassezia. Susceptibility Testing 240
8.2.2 .Standard Methods and Selection of .Malassezia. Colonies for Susceptibility Testing from Mixed Blood Cultures and Skin 240
8.2.3 ..In vitro. Response of .Malassezia. Yeasts to Antifungal Agents 241
8.2.4 .New Formulations and Newer Antifungal Agents 243
8.2.5 ..Malassezia. Susceptibility to Synthetic and Naturally Occurring Compounds 246
8.2.5.1 .Ciclopirox olamine 246
8.2.5.2 .Rilopirox 246
8.2.5.3 .Xanthorrhizol 247
8.2.5.4 .Australian Tea Tree Oil 247
8.2.5.5 .Cathelicidin 247
8.2.6 .Corneofungimetry: A Bioassay Predicting Drug Efficacy 247
8.3 .Molecular Epidemiology of Nosocomial Outbreaks 248
8.4 .Conclusions 250
References 251
156722_1_En_9_Chapter_OnlinePDF 256
9 256
Genomics and Pathophysiology: Dandruff as a Paradigm 256
9.1 .Introduction 257
9.2.Genome Size 258
9.3 .Phylogenetic Relationship with Other Fungi 259
9.4 .Lipid and Amino Acid Metabolism 259
9.5 .Lipases 261
9.6 .Aspartyl Proteases 264
9.7 .Phospholipase C 265
9.8 .Acid Sphingomyelinases 265
9.9 .Allergens 265
9.10 .Tryptophan Metabolites 268
9.11 .Mating 268
9.12 .Adaptation to Animal Skin 268
9.13 .Conclusion 269
References 269
156722_1_En_10_Chapter_OnlinePDF 273
10 273
Malassezia. Yeasts in Animal Disease 273
10.1 ..Malassezia pachydermatis. as a Pathogen in the Dog 273
10.1.1 .Historical Aspects of Infection in Dogs 273
10.1.2 .Factors Predisposing to Diseases 275
10.1.2.1 .Breed Predilections 275
10.1.2.2 .Concurrent Diseases 275
10.1.3 .Pathogenesis 276
10.1.4 .Clinical Signs 278
10.1.5 .Diagnosis 280
10.1.6 .Treatment of .Malassezia. Otitis and Dermatitis in Dogs 282
10.1.6.1 .Treatment of .Malassezia. Otitis Externa in Dogs 283
10.1.6.2 ..Malassezia. Otitis Media 285
10.1.6.3 .Treatment of .Malassezia. Dermatitis in Dogs 285
10.2 ..Malassezia. spp. as Pathogens in Cats 286
10.2.1 .Factors Predisposing to Disease 286
10.2.2 .Clinical Signs 287
10.2.3 .Approach to Diagnosis 288
10.2.4 .Treatment and Management 289
10.3 ..Malassezia. spp. as Pathogens in Other Animals 289
10.3.1 ..Malassezia pachydermatis 289
10.3.2 .Lipid-Dependent .Malassezia. Species 291
10.4 .Zoonotic Transmission of .M. pachydermatis 293
References 294
156722_1_En_11_Chapter_OnlinePDF 302
11 302
Malassezia. Database 302
11.1 .Introduction 302
11.2 .Description of Functionalities 304
11.2.1 .Fields and Data 304
11.2.2 .General Search 306
11.2.3 .Advanced Search 307
11.2.4 .Additional Notes on Complex Queries 308
11.2.5 .Online Deposit of Data 308
11.2.6 .Registration 308
11.2.7 .Deposit of New Record 309
11.2.8 .Modification or Deletion of Existing Record 309
11.3 .Online Identification 309
11.3.1 .Pairwise Sequence Alignments 309
11.3.2 .Polyphasic Identification 310
11.4 .Conclusions 311
References 312
156722_1_En_BookBackmatter_OnlinePDF 313

"5.3.4 Cellular Responses and Cytokine Production (p.144-145)

Phagocytes form an important part of the innate immune defence against fungi and the interaction of neutrophils and Malassezia has been examined in several studies. The uptake and killing of Malassezia by neutrophils in vitro is a complement-dependent process [67]. Uptake is maximal at 40 min, after which it plateaus, but killing of the ingested yeast is very inefficient, with only 5% of the cells killed after 2 h. This lack of killing is in contrast to other yeast and fungal genera, where killing of up to 80% of cells occurs [68, 69]. In this study, if Malassezia cells were pre-treated with ketoconazole, killing increased to 23%, with the amount of killing proportional to increasing drug concentrations. Several possible explanations have been proposed for this inability of neutrophils to kill Malassezia.

When grown in the presence of oleic acid, Malassezia produces azelaic acid, a C9 dicarboxylic acid [70]. Azelaic acid decreases production of O2 − and OH. by neutrophils in a dosedependent manner and also reduces H2O2 production, due to inhibition of cellular metabolism [71]. It is also an oxygen radical scavenger [72], and if azelaic acid is produced by Malassezia in vivo, this may help to protect it from the oxygen-dependent killing mechanisms used by neutrophils. Another factor that has been suggested to help protect Malassezia from phagocytic killing is the presence of a lipid-rich capsular-like layer around the yeast cells [73].

Preliminary data suggest that the capsular-like layer reduced Malassezia uptake and activation of neutrophils and that this may contribute to their protection during phagocytosis [74]. More recently, the role of some of the tryptophan metabolites of Malassezia yeasts in this lack of neutrophil activity against Malassezia have been demonstrated [75]. M. furfur can convert tryptophan into a range of indole alkaloids, including the pityriarubins (A, B and C).

Neutrophils were obtained from healthy donors and stimulated with a calcium ionophore to stimulate superoxide release. When the pityriarubins were added, they caused a decrease in the production of reactive oxygen species (ROS) in a concentration dependent manner, with pityriarubin C being most active in the assay. The authors concluded that this ability to produce such compounds would enable Malassezia to downregulate the immune response directed against it and contribute to the lack of inflammation seen in PV.

Binding between Malassezia and phagocytic cells has been studied in the human monocytic cell line THP-1, and is mediated by the mannose receptor, b-glucan receptor and complement receptor 3 [76]. When the THP1 cells were stimulated with live or heat-killed Malassezia cells, the production of IL8 increased in a time and concentration-dependent pattern [77]. Stimulation of the granulocyte cell line, HL60, by Malassezia increased the levels of both IL8 and IL1a, again in a time and concentration dependent pattern.

This stimulation of monocytic cells by Malassezia and the resultant production of IL8 and IL1a will lead to the chemotaxis of neutrophils and T-cells and hence augment the inflammatory response. Chemoattraction of neutrophils from psoriatic, atopic and healthy controls in response to Malassezia was studied by Bunse et al. [78]. Using a Boyden chamber, cells of M. furfur were incubated in the lower part of the chamber, with the test neutrophils in the upper part and after three hours, the neutrophils that had crossed the membrane separating the two parts of the chamber were counted."