Identification of Malassezia Species Isolated From Patients With Pityriasis Versicolor in Sari, Iran, 2012

Background: The genus Malassezia is part of the normal mycota of the skin of humans and other warm-blooded animals as etiological agents of pityriasis versicolor. Objectives: Several species from the Malassezia genus are known based on morphological, biochemical and molecular approaches. Therefore, the aim of this study was to determine the distribution of Malassezia species in patients with pityriasis versicolor based on morphological, physiological and biochemical criteria in Sari, Iran. Materials and Methods: In total, among 134 patients clinically suspected of having pityriasis versicolor, attending the Department of Mycology, Boali Sina Hospital and Referral Laboratory of the Mazandaran University of Medical Sciences, 116/134 (86.5%) positive patients for Malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. All 116 samples were inoculated on plates containing modified Leeming and Notman agar medium and identified at species level based on mycological criteria. Results: However, only 100/116 (86.2%) or 100/134 (74.6 %) of the patients showed Malassezia spp in culture. Malassezia. globosa (54%) was the most commonly isolated species followed by M. furfur (32%), M. slooffiae (6%), M. restricta (6%) and M. sympodialis (2%). Mixed Malassezia species were not identified. Conclusions: M. globosa was found to be the predominant pityriasis versicolor isolate in Sari, Iran. Since Malassezia species show different responses in their antifungal therapy, thus correct identification of Malassezia species and antifungal susceptibility test could facilitate selection of appropriate antifungal agents.