Malassezia pachydermatis isolated from a South American sea lion (Otaria byronia) with dermatitis

A fungus was isolated from the skin of an Otaria byronia and from the water of the pool in which the animal was kept. It formed creamy colonies with s oft texture on Dixon agar and grew well without supplements of long-chain f atty acids. Cells were ovoid to cylindrical in shape, budded from a broad b ase, and budded and divided at the same location. Thus, the isolate was ide ntified as M. pachydermatis. We compared this very rare isolate from a mari ne mammal with four strains of M. pachydermatis using the freeze-etching el ectron-microscopy technique. The cells showed the same characteristic ring- swellings on the protoplasmic membrane on the neck site between the mother and the daughter parts, and the same accumulation of circumvallate bulgings in a small area near the straight sections of spiral grooves as four refer ence strains. Thus, in terms of morphology and ultrastructure, the isolate could be regarded as a typical M. pachydermatis.