[Identification of causative species in malassezia-associated dermatoses].

The Tween test was used to identify Malassezia species isolated from patients with pityriasis versicolor and seborrhoeic dermatitis, and suckling infants with seborrhoeic dermatitis. The most common species isolated from cases of pityriasis versicolor was M. globosa (55%), and this species was surmised to be the principal causative organism of this disease. In both adult and suckling infant cases of seborrhoeic dermatitis, M. globosa and M. furfur were isolated at high incidences compared with the healthy control subjects, indicating the possibility that one or both of these species are the causative organisms of these diseases. In addition, scales were collected from lesions of pityriasis versicolor for use as the template, and the involved Malassezia species were identified by the PCR method using the DNA sequences of nuclear ribosomal internal transcribed spacer l. The most commonly detected species was M. globosa, found in 97% of the cases, and this was followed in frequency by M. restricta (79%) and M. sympodialis (68%). It was also elucidated that multiple Malassezia species can be detected in the same specimen.