Clinical and epidemiological features of the genus Malassezia in Iran

BACKGROUND AND OBJECTIVES: The genus Malassezia contains an expanding list of lipophilic yeasts involve in the etiology of various superficial fungal infections. Pityriasis versicolor (PV) is the most prevalent Malassezia-related infection distributed worldwide. In the present study, clinical and epidemiological features of the genus Malassezia are discussed with special focus on PV in Iran. MATERIALS AND METHODS: During June 2012 to April 2013, among 713 confirmed cases of fungal infections, 68 (9.5%) were diagnosed as PV by positive direct microscopy results in 20% potassium hydroxide (KOH) preparation of skin scrapings. All the specimens were cultured on modified Dixon agar and incubated at 32°C for 10 days. Identification of the isolated yeasts was carried out based on macro- and microscopic morphology, catalase test, utilization of Tweens, polyethoxylated castor oil (EL slant), and hydrolysis of esculin and utilization of Tween-60 (TE slant). RESULTS: Out of 68 skin scrapings, 55 (80.9%) yielded yeast colonies on mDixon’s agar which were finally identified as M. globosa (36.36%), M. pachydermatis (29.08%), M. furfur (23.65%), M. slooffiae (7.28%) and M. obtusa (3.64%). CONCLUSION: Results of the present study further indicate clinico-epidemiological importance of the genus Malassezia with growing importance of M. pachydermatis as a major species involve in the etiology of pityriasis versicolor. These findings are of major concern in management of Malassezia-related diseases.