Psoriasis is a common clinical disease, and its pathogenesis is closely related to infecting microorganisms. Studies in recent years indicated that Malassezia plays an important role in occurrence and development of p...Psoriasis is a common clinical disease, and its pathogenesis is closely related to infecting microorganisms. Studies in recent years indicated that Malassezia plays an important role in occurrence and development of psoriasis. This study provides an overview on the role of Malassezia in development of psoriasis based on three aspects, namely, clinical observation,antifungal therapy, and immunology research.展开更多
Background: Malassezia pachydermatis is the main causative agent of canine otitis and also of a myriad of dermatological problems in companion animals;its interaction mechanisms with host cells are still unclear. Obje...Background: Malassezia pachydermatis is the main causative agent of canine otitis and also of a myriad of dermatological problems in companion animals;its interaction mechanisms with host cells are still unclear. Objectives: To establish an in vitro infection model of M. pachydermatis-exposed RK13 cells in order to evaluate cell morphological changes as well as changes in the structure of actin filaments. Methods: Cultures of RK13 cells were infected with M. pachydermatis, alterations caused by the yeast were evaluated by optical and fluorescence microscopy. Results: M. pachydermatis adheres itself to the cell and produces the formation of multiple agglomerates that cause changes in cell morphology, formation of cell aggregates in overlays, presence of syncytia and destruction of cell culture structure. The damaged cells presented changes in the actin filaments consisting of thickening of the cell cortex and loss of stress fibers. On the other hand, the formation of perinuclear actin rings in the yeasts was observed. Conclusions: An in vitro infection model was established with M. pachydermatis and alterations in cell morphology were observed consisting of changes in the structure of the actin filaments, overgrowth of the cells and the presence of syncytia.展开更多
Introduction: The genus Malassezia comprises 17 species of commensal and pathogenic yeasts of homeotherms animal skin. The most common species are M. furfur, M. globosa, and M. sympodialis in humans and M. pachydermat...Introduction: The genus Malassezia comprises 17 species of commensal and pathogenic yeasts of homeotherms animal skin. The most common species are M. furfur, M. globosa, and M. sympodialis in humans and M. pachydermatis in animals. However, some publications have reported potentially serious human infections by M. pachydermatis in individuals with risk factors and the isolation of human species from domestic animals. Given the scarcity of information about their capacity for transmission between hosts and zoonotic potential, the aim of the present study was to physiologically and molecularly characterize Malassezia spp. isolates obtained from canines and their human owners. Materials and Methods: An experimental study was conducted at the Veterinary Clinic of Universidad de Ciencias Aplicadas y Ambientales of Bogotá (Colombia) from July 2015 to December 2016. Phenotypic identification and molecular characterization via the amplification of the 5.8S rDNA- ITS2 and 26S rDNA gene regions, nucleic acid sequencing, and phylogenetic analyses were performed on isolates originating from canines with otitis externa and from the skin of healthy owners compatible with Malassezia spp. Results: Eighty samples were cultured, of which 32 (40%) were suggestive of Malassezia spp. A total of 29 out of 46 (63%) isolates in canines and 3 out of 34 (9%) isolates in humans corresponded entirely with M. pachydermatis. Isolates from the canines and their owners presented similar behavior in biochemical and phospholipase activity tests, 100% molecular sequence identities, and close proximity in the phylogenetic trees. Conclusion: The isolation of M. pachydermatis from humans and their dogs with identity based on biochemical, physiological, molecular, and phylogenetic perspectives indicate the ability of this species to adapt to new hosts and its potential for zoonotic transmission. These findings contribute to knowledge of the ecology of this important fungus in human and veterinary medicine.展开更多
Background: Malassezia folliculitis is an infection of the hair follicle, which commonly affects young adult, and is often misdiagnosed as truncal acne. Objectives: To shed light on different clinical, histopathologic...Background: Malassezia folliculitis is an infection of the hair follicle, which commonly affects young adult, and is often misdiagnosed as truncal acne. Objectives: To shed light on different clinical, histopathological, and microbiological aspects of Malassezia folliculitis and to be compared with truncal acne. Patients and Methods: This is a descriptive comparative cross sectional, out patient based study, which was conducted at the Department of Dermatology, Basrah Teaching Hospital from October 2008 to October 2009. Total number of 113 patients with papular and/or pustular follicular skin lesions on the trunk were enrolled in this study. They were divided according to the clinical features, Wood’s light examination, direct microscopic examination, PAS stained skin biopsy and the response to a trial of antifungal drugs into two groups: group 1: patient with Malassezia folliculitis and group 2: patient with truncal acne vulgaris. Results: Group 1: They were 53(46.9%) out of a total 113, 33(62.3%) males and 20(37.7%) females, their ages ranged from 19 - 40 years. Group 2 consisted of 60(53.1%) patients, 25(41.6%) males and 35(58.4%) females, whose ages ranged from 14 - 29 years. The ages were earlier in the acne group in comparison with MF group (p Malassezia folliculitis was more common among males than females, while in truncal acne, females predominated males. The center of the back was the predominant site among MF group affecting (90.6%) of patients with sparing the face, in contrast to truncal acne where the periphery of the back was involved in (91.7%) and the face in (75%) (p 0.0001). Wood’s light examination, skin scrapping and PAS stained skin biopsies were also positive in all patients with MF in contrast to acne group where all these tests were negative. All MF patients showed marked response to a two weeks trial of antifungal while the reverse is true for the acne patients, whereas the antibiotic was the second most common leading aggravating factor in 20 (37.7%) of cases with MF, which was significantly different from acne group (p 0.0001). Conclusion: Malassezia folliculitis should be considered in young adults with an itchy papulopustulr follicular eruptions affecting the trunk that should be differentiated from truncal acne by their characteristic clinical, histopathological features and its remarkable response to antifungal therapy.展开更多
The prevalence rate of acne in China is continuously increasing in adolescents, young and middle-aged adults. In many cases, those who have refractory inflammatory papules and pustules on the face and mandibular have ...The prevalence rate of acne in China is continuously increasing in adolescents, young and middle-aged adults. In many cases, those who have refractory inflammatory papules and pustules on the face and mandibular have received long-term antibiotic therapy. Some severe cases have had isotretinoin treatment and even corficosteroid application by either topical or oral administration. The curative effect has not been prominent in these cases, even with combined treatment including antimicrobials and/or isotretinoin and Chinese patent medicines.展开更多
文摘Psoriasis is a common clinical disease, and its pathogenesis is closely related to infecting microorganisms. Studies in recent years indicated that Malassezia plays an important role in occurrence and development of psoriasis. This study provides an overview on the role of Malassezia in development of psoriasis based on three aspects, namely, clinical observation,antifungal therapy, and immunology research.
文摘Background: Malassezia pachydermatis is the main causative agent of canine otitis and also of a myriad of dermatological problems in companion animals;its interaction mechanisms with host cells are still unclear. Objectives: To establish an in vitro infection model of M. pachydermatis-exposed RK13 cells in order to evaluate cell morphological changes as well as changes in the structure of actin filaments. Methods: Cultures of RK13 cells were infected with M. pachydermatis, alterations caused by the yeast were evaluated by optical and fluorescence microscopy. Results: M. pachydermatis adheres itself to the cell and produces the formation of multiple agglomerates that cause changes in cell morphology, formation of cell aggregates in overlays, presence of syncytia and destruction of cell culture structure. The damaged cells presented changes in the actin filaments consisting of thickening of the cell cortex and loss of stress fibers. On the other hand, the formation of perinuclear actin rings in the yeasts was observed. Conclusions: An in vitro infection model was established with M. pachydermatis and alterations in cell morphology were observed consisting of changes in the structure of the actin filaments, overgrowth of the cells and the presence of syncytia.
文摘Introduction: The genus Malassezia comprises 17 species of commensal and pathogenic yeasts of homeotherms animal skin. The most common species are M. furfur, M. globosa, and M. sympodialis in humans and M. pachydermatis in animals. However, some publications have reported potentially serious human infections by M. pachydermatis in individuals with risk factors and the isolation of human species from domestic animals. Given the scarcity of information about their capacity for transmission between hosts and zoonotic potential, the aim of the present study was to physiologically and molecularly characterize Malassezia spp. isolates obtained from canines and their human owners. Materials and Methods: An experimental study was conducted at the Veterinary Clinic of Universidad de Ciencias Aplicadas y Ambientales of Bogotá (Colombia) from July 2015 to December 2016. Phenotypic identification and molecular characterization via the amplification of the 5.8S rDNA- ITS2 and 26S rDNA gene regions, nucleic acid sequencing, and phylogenetic analyses were performed on isolates originating from canines with otitis externa and from the skin of healthy owners compatible with Malassezia spp. Results: Eighty samples were cultured, of which 32 (40%) were suggestive of Malassezia spp. A total of 29 out of 46 (63%) isolates in canines and 3 out of 34 (9%) isolates in humans corresponded entirely with M. pachydermatis. Isolates from the canines and their owners presented similar behavior in biochemical and phospholipase activity tests, 100% molecular sequence identities, and close proximity in the phylogenetic trees. Conclusion: The isolation of M. pachydermatis from humans and their dogs with identity based on biochemical, physiological, molecular, and phylogenetic perspectives indicate the ability of this species to adapt to new hosts and its potential for zoonotic transmission. These findings contribute to knowledge of the ecology of this important fungus in human and veterinary medicine.
文摘Background: Malassezia folliculitis is an infection of the hair follicle, which commonly affects young adult, and is often misdiagnosed as truncal acne. Objectives: To shed light on different clinical, histopathological, and microbiological aspects of Malassezia folliculitis and to be compared with truncal acne. Patients and Methods: This is a descriptive comparative cross sectional, out patient based study, which was conducted at the Department of Dermatology, Basrah Teaching Hospital from October 2008 to October 2009. Total number of 113 patients with papular and/or pustular follicular skin lesions on the trunk were enrolled in this study. They were divided according to the clinical features, Wood’s light examination, direct microscopic examination, PAS stained skin biopsy and the response to a trial of antifungal drugs into two groups: group 1: patient with Malassezia folliculitis and group 2: patient with truncal acne vulgaris. Results: Group 1: They were 53(46.9%) out of a total 113, 33(62.3%) males and 20(37.7%) females, their ages ranged from 19 - 40 years. Group 2 consisted of 60(53.1%) patients, 25(41.6%) males and 35(58.4%) females, whose ages ranged from 14 - 29 years. The ages were earlier in the acne group in comparison with MF group (p Malassezia folliculitis was more common among males than females, while in truncal acne, females predominated males. The center of the back was the predominant site among MF group affecting (90.6%) of patients with sparing the face, in contrast to truncal acne where the periphery of the back was involved in (91.7%) and the face in (75%) (p 0.0001). Wood’s light examination, skin scrapping and PAS stained skin biopsies were also positive in all patients with MF in contrast to acne group where all these tests were negative. All MF patients showed marked response to a two weeks trial of antifungal while the reverse is true for the acne patients, whereas the antibiotic was the second most common leading aggravating factor in 20 (37.7%) of cases with MF, which was significantly different from acne group (p 0.0001). Conclusion: Malassezia folliculitis should be considered in young adults with an itchy papulopustulr follicular eruptions affecting the trunk that should be differentiated from truncal acne by their characteristic clinical, histopathological features and its remarkable response to antifungal therapy.
文摘The prevalence rate of acne in China is continuously increasing in adolescents, young and middle-aged adults. In many cases, those who have refractory inflammatory papules and pustules on the face and mandibular have received long-term antibiotic therapy. Some severe cases have had isotretinoin treatment and even corficosteroid application by either topical or oral administration. The curative effect has not been prominent in these cases, even with combined treatment including antimicrobials and/or isotretinoin and Chinese patent medicines.
