Frequency of Different Malassezia Species in Scalp Dandruff

Members of the Malassezia genus are often lipophilic, observed as budding yeasts and found as commensals in the skin of humans. This genus opportunistically reside in several areas including scalp where under the influence of particular predisposing factors, their proliferation is increased (e.g., high activation of sebaceous glands), and leads to dandruff and seborrheic dermatitis, which together affects >50% of human beings. The proliferation of yeasts in scalp creates health and hair hygiene problems. In this study we determined the type and frequency of Malassezia species in scalp dandruff in order to have epidemiologic and therapeutic understanding.
Differentiation tests were done for scalp samples, including: morphology, Tween 20, 40 and 80 assimilation tests, hydrolysis of bile-esculin, catalase and growth on Sabouraud dextrose agar with chloramphenicol and cycloheximide (SCC) and sediment production on mDixon agar medium.
Frequency of various Malassezia species from 140 scalp samples from volunteers of both gender were found as: M. globosa (46.5%), followed by M. furfur (27.0%), M. restricta (12.7%), M. sympodialis (6.5%) and M. slooffiae (0.8%).
In view of high prevalence ofM. globosa, its invasive characteristics and the role of predisposing factors in the more proliferation of this species in scalp should be considered.