Revised culture-based system for identification of Malassezia species.
Forty-six strains of Malassezia spp. with atypical biochemical features were isolated from 366 fresh clinical isolates from human subjects and dogs. Isolates obtained in this study included 2 (4.7%) lipid-dependent M. pachydermatis isolates; 1 (2.4%) precipitate-producing and 6 (14.6%) non-polyethoxylated castor oil (Cremophor EL)-assimilating M. furfur isolates; and 37 (34.3%) M. slooffiae isolates that were esculin hydrolyzing, 17 (15.7%) that were non-tolerant of growth at 40 degrees C, and 2 (1.9%) that assimilated polyethoxylated castor oil. Although their colony morphologies and sizes were characteristic on CHROMagar Malassezia medium (CHROM), all strains of M. furfur developed large pale pink and wrinkled colonies, and all strains of M. slooffiae developed small (<1 mm) pale pink colonies on CHROM. These atypical strains were distinguishable by the appearance of their colonies grown on CHROM. Three clinically important Malassezia species, M. globosa, M. restricta, and M. furfur, were correctly identified by their biochemical characteristics and colony morphologies. The results presented here indicate that our proposed identification system will be useful as a routine tool for the identification of clinically important Malassezia species in clinical laboratories.
Kaneko
Takamasa
T
Kanto Chemical Co Inc, Marusan Bldg, Tokyo, Japan.
Makimura
Koichi
K
Abe
Michiko
M
Shiota
Ryoko
R
Nakamura
Yuka
Y
Kano
Rui
R
Hasegawa
Atsuhiko
A
Sugita
Takashi
T
Shibuya
Shuichi
S
Watanabe
Shinichi
S
Yamaguchi
Hideyo
H
Abe
Shigeru
S
Okamura
Noboru
N
D000328:Adult; D000818:Animals; D003362:Cost-Benefit Analysis; D003470:Culture Media; D004285:Dogs; D006801:Humans; D008290:Malassezia / Q000254:growth & development / Q000302:isolation & purification*; D010641:Phenotype; D011136:Polysorbates / Q000378:metabolism
D003470:Culture Media; D011136:Polysorbates