The genetic diversity of clinical isolates of Malassezia pachydermatis from dogs and cats.

Molecular investigation of 110 clinical isolates of non-lipid-dependent Malassezia pachydermatis from dogs and cats was carried out by random amplification of polymorphic DNA (RAPD) and chitin synthase 2 (CHS2) gene sequence analyses. The RAPD analysis indicated that the clinical isolates of M. pachydermatis constituted four distinct genetic types (A, B, C and D). Moreover, the results from CHS2 gene analysis completely agreed with those from the RAPD analyses. The clinical isolates of M. pachydermatis were obtained from normal external ears, lesions of atopic dermatitis, flea allergic dermatitis, otitis externa, pyoderma and seborrheic dermatitidis in dogs and cats. Type A consisted of 93 clinical isolates as well as the ex-neotype strain of M. pachydermatis. The isolates of type A M. pachydermatis originated from lesions of all kinds of diseases. They were predominant on dog and cat skin. The other types, B, C, and D were isolated mainly from otitis externa.