CHARACTERIZATION OF TYPICAL AND ATYPICAL MALASSEZIA SPP. FROM CATTLE AND DOG BY RANDOM AMPLIFIED POLYMORPHIC DNA ANALYSIS

Yeasts of the Malassezia Genus – Recent Findings

The genus Malassezia is a medically important genus of yeasts that can colonize the skin of humans and other warm-blooded animals. The genus currently comprises 18 species of which four new species were identified recently. The most widely known species, M. pachydermatis, occurs in animals but was detected also in humans, namely at life endangering septicaemias and in prematurely born children. Proliferation of Malassezia occurs most frequently as a result of disturbances in the normal homeostasis of host immunity on the one hand and virulence of these yeasts on the other hand. The successful management of the disease depends on the therapeutic control of overgrowth of the yeasts and any concurrent bacterial infection by local or systemic anti microbial treatment, as well as, on identification and potential correction of the predisposing factors.

Occurrence of Malassezia Yeasts in Dermatologically Diseased Dogs

The Malassezia genus is represented by several lipophilic yeasts, normally present on the skin of many warm-blooded vertebrates, including humans. The aim of this study was to investigate the occurrence of Malassezia yeasts in dogs with skin lesions (dermatitis, interdigital dermatitis and inflammation of anal sacs) and otitis externa. The presence of Malassezia spp. was investigated in a group of 300 dogs exhibiting clinical manifestations. The isolates of Malassezia were identified by using phenotypic (biochemical-physiological and morphological characteristics) and genotypic methods (PCR, RFLP-AluI, BanI and MspA1I) which allowed their precise identification. Malassezia yeasts were isolated from 84 specimens obtained from 76 positive dogs. M. pachydermatis was the most frequently isolated species (79 isolates) in this study. M. furfur was identified in four dogs and M. nana in one dog. The prevalence of isolated Malassezia spp. was 25.3 % in dogs with skin lesions; from which 36.0 % were dogs suffering from otitis externa, 24.5 % from dogs having dermatitis, 16.4 % from dogs with interdigital dermatitis and 14.3 % from dogs having inflammation of the anal sacs. A higher prevalence of Malassezia spp. was observed in animals with pendulous ears in comparison with dogs having erect ears.