344 An Introduction to Medical Mycology 



reliance is to be plaeecl on a direct mount. We use a technic of staining 

 with methylene blue (see the section on the direct mount, Chapter XVIII, 

 pp. 235 ff. ). The organism is noted as an ovoid or spherical cell with or 

 without budding. The flask-shaped cell is characteristic. The diameter varies 

 from 2 to 10 microns. 



(b) Cultural characteristics.— The medium which Moore found most 

 favorable for primary isolation is wort agar, which, as already mentioned, 

 is a Difco product with a pH of 4.8. He reported success in approximately 

 10 per cent of cases. The following medium may be used for subculture 

 when it is desired to keep the growth alive: 



Technical maltose, and 



Technical dextrose aa 2 per cent 



Peptone 1 per cent 



Agar 1.8 per cent 



Distilled water q.s. 



Wheat germ oil or butter should then be added, since Benham has shown 

 that P. ovale requires a fatty environment. We studied three strains. The 

 growth was first noted on the fourth day after inoculation. The rate of 

 growth was slow to moderate, the ultimate size being limited. The color 

 was tan. The cultures were compact, smooth and glistening, with no 

 bubbles. 



According to Moore, the colony measures approximately 2 cm. in diam- 

 eter after 40 days. The culture is pulvinate, with radiating ridges to the 

 periphery, a rough surface and a few small excrescences. The color is dull 

 and varies from light ochraceous salmon to pinkish buff. 



(c) Culture mount.— The cells vary from 3 to 15 microns in diameter, 

 most of them being from 4 to 5 microns. There are many budding cells 

 resembling bottles or gourds. The large cells appear to be thickly encap- 

 sulated or to have a thick gelatinous structure due to the medium. Several 

 cells show more than one bud. The budding cells appear to be small or 

 divided. Elongated forms had a mean length and width of 5 and 4 microns, 

 respectively. 



( d ) Animal inoculation.— Moore's cultural growth has been inoculated 

 into the skin of rabbits, with a resultant scaly rash which disappeared spon- 

 taneously. 



BIBLIOGRAPHY 



Acton, II. W., and Panja, G. : Seborrheic dermatitis or pityriasis capitis: Lesion caused by 



Malassezia ovale, Indian M. Gaz. 62:603, 1927. 

 Benham, R. W.: Cultural characteristics of Pityrosporum ovale— lvpophvtic fungus, J. Invest. 



Dermat. 2:187, 1939. 

 Castellani, A.: Notes on three new yeast-like organisms and a new bacillus, with remarks on 



clinical conditions from which they have been isolated— furunculosis blastomycetiea, macro- 



glossia blastomycetiea, stomatitis cryptococco-bacillaris, J. Trop. Med. 28:217, 1925. 



