MALASSEZIA 367 



up. The primary colonies appear small, dry, and chalky, visible on the third 

 day. Secondary cultures will grow on the thick part of Petroff's medium, 

 which is still moist, on glucose agar, ordinary agar, and even on glucose broth. 

 Macleod & Dowling- (1928) and Benedek (1930) have also claimed the 

 culture of the bottle bacillus of Unna, but in no case have they established the 

 pathogenicity of the organism cultivated. Benedek describes his organism as 

 follows : Cells mostly spherical, hyaline, 7.8-10.4/x, solitary or rarely in small 

 groups, forming neither hyphae nor spores. On Sabouraud's agar (pH 4.7-4.9) 

 and on 8% glucose agar (pH 6.9-7.1), under strictly aerobic conditions, colony 

 smooth, rounded and brown. He also reports growth on malt extract, glucose, 

 and maltose broth, and acid formation with glucose, fructose, sucrose, and mal- 

 tose solutions and on milk. No fermentation, no liquefaction of gelatin. 



Ota & Huang (1933) report further details of cultures, using a strain 

 isolated by Acton & Panja, Crypfccoccus graciloides Castellani and a strain 

 isolated by Huang which they consider conspecific. Cells typically ovoid, al- 

 though spherical and bottle-shaped forms may be seen, 2-2. 5/a often united in 

 pairs. Very rarely suggestions of arthrospores were observed, but probably 

 no true arthrospores are produced. On egg medium at the end of several 

 months, senescent cells are 3-5/x, thick-walled, usually solitary spherical, ovoid, 

 or more or less angular, with a large central oil drop, sometimes occurring in 

 short chains with a thin gelified sheath. No mycelium seen. Gram stain colors 

 the protoplasm completely in young cells, less so in adults ; Giemsa stain 

 variable. 



Petragni's medium found to be the most favorable, colonies becoming 1 

 mm. in diameter, becoming confluent, especially in moister portions, forming 

 a crustose membrane, granular, moist, ivory white, finally brownish. Ten 

 per cent glucose agar to which a little (about 10%) butter has been added is 

 also favorable, slightly more so than Petroff's medium. On Sabouraud glu- 

 cose, colonies very fine, suggesting those of Neisseria. On malt extract, a 

 slight deposit, but no ring or pellicle. No ascospores observed No fer- 

 mentation. 



Ota & Huang were unable to prove the pathogenicity of their strains 

 (intravenous and intraperitoneal injections!). 



Moore (1934) succeeded in isolating Malassezia on wort agar, proving its 

 pathogenicity. Growth is ver,y slow at first but increases after repeated subcul- 

 ture on this medium. He describes his cultures as follows : 



On Sabouraud agar, colony flat, light ochraceous salmon, dull Avith slight 

 ridges at the margin, cells spherical, 3-lOju mostly 4-5;Ui in diameter. On wort 

 agar, colony pulvinate with radial ridges, surface rough, light ochraceous 

 salmon to pinkish buff, dull cells 3-15/a mostly 4-5/^, bottle-shaped cells com- 

 mon, the larger cells with a thick capsule. On malt extract agar, colony pink- 

 ish cinnamon with a circular flat plateau in the center Avith fine radial ridges. 

 Cells spherical or ovoid, 2-7/x mostly 4-5/a. On Raulin's agar and Richard's agar, 

 growth similar but very poor. On corn meal agar colony ochraceous buff, 



