CHAPTER XIV 



MALASSEZIA 



Malassezia Baillou, Traite de Bot. Med. Cryptog. 243, 1889. 



Pityrosporum Sabouraud 1895; Castellani & Chalmers, Man. Trop. Med. 

 ed. 2, 836-837, 1913. 



The type species is Microsporon furfur Robin. 



The members of this genus are obligate parasites confined to the outer 

 layers of the epidermis and the sebaceous glands, not easily isolated and very 

 easily dying out after the first transplant. In the scales, small yeast cells 

 and occasional mycelium are shown. Colony dry and chalky. 



The organisms of this group have been too infrequently cultivated and 

 too poorly described to be placed definitely, but their very difi'erent cultural 

 requirements and their very specialized habitat suggest that they belong to 

 a different genus. One can only speculate whether they represent a very de- 

 generate and highly specialized dermatophyte related to Achorion or whether 

 they are related to yeasts. Their habitat on the host, suggests the former alter- 

 native, especially as the organism starts in the homy layer of the epidermis, 

 and invades the hair follicle without attacking the hair shaft. The yeasts on 

 the whole show much less narroAv specialization to a habitat, being rarely 

 localized on the outer layers of the skin, and when in this situation produce 

 much more acute lesions. 



Malass«zia furfur (Robin) Baillon, Traite Bot. Med. Cryptog. 243, 1889. 



Microsporon furfur Robin. Hist. Nat. Veg. Parasit. 436-439, 1853. 



Epidermophyton sj). Bazin, Lecons . . . sur les Affections Parasites de la 

 Peau, 1862. 



Sporotrichum (Microsporon) furfur Saccardo, Syll. Fung. 4: 100, 1886. 



Oidium {Microsporon) furfur Zopf, Die Pilze, 257, 1890. 



Oidium subtile Kotliar, Vratche No. 12: 2055, 1892 [in Russian]. 



Monilia furfur Vuillemin, Champ. Parasit. Homme Anim. 89, 1931. 



This is the organism of pityriasis versicolor, isolated and described from 

 the scales. Cultures reported by Schmitter, Jour. Trop. Med. Hyg. 26: 190- 

 194, 1923, and by Macleod & Dowling, British Jour. Derm. Syphilis 40: 139- 

 148, 1928. From his description, Kotliar probably had an Actinomyces species, 



Hyphae 2-3/* in diameter. Spores 3-8/* in diameter, spherical or ovoid, very 

 refractive, often budding, striated with spiral striae formed by budding, often 

 in clusters, not easily stained. Method of staining: fix scales in absolute 

 alcohol, stain with light green, eosin, or even zinc chloriodide. 



On glycerol agar, there is a free, glistening, yellowish growth along 

 streak. After a week, tiny white drops appear on the surface. These enlarge 

 to 2 mm. in diameter and appear crateriform. Broth clouds with heavy sedi- 



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