Genotype Analyses of Human Commensal Scalp Fungi, Malassezia globosa, and Malassezia restricta on the Scalps of Patients with Dandruff and Healthy Subjects

Abstract

Dandruff and seborrheic dermatitis are common afflictions of the human scalp caused by commensal scalp fungi belonging to the genus Malassezia. Malassezia globosa and Malassezia restricta are the predominant species found on the scalp. The intergenic spacer regions of these species' rRNA genes contain short sequence repeats (SSR): (GT)n and (CT)n in M. globosa and (CT)n and (AT)n in M. restricta. In the present study, we compared the genotypes (SSR) of M. globosa and M. restricta colonizing the scalps of patients with dandruff and healthy individuals. For M. globosa, the genotype (GT)10:(CT)8 (40.3 %, 25/62) was predominant followed by (GT)9:(CT)8 (14.5 %, 9/62) and (GT)11:(CT)8 (14.5 %, 9/62) in patients with dandruff, whereas the genotypes in healthy subjects were diverse. For M. restricta, the genotype (CT)6:(AT)6 (59.7 %, 37/62) was predominant followed by (CT)6:(AT)8 (24.2 %, 15/62) in patients with dandruff, while four genotypes, (CT)6:(AT)6 (10.5 %, 6/57), (CT)6:(AT)7 (22.8 %, 13/57), (CT)6:(AT)8 (17.5 %, 10/57), and (CT)6:(AT)10 (21.1 %, 12/57), accounted for 71.9 % of all combinations in healthy subjects. The results of this study suggest that the M. globosa genotype (GT)10:(CT)8 and the M. restricta genotype (CT)6:(AT)6 may be involved in the development of dandruff.

Oral Microbiota Composition and Antimicrobial Antibody Response in Patients with Recurrent Aphthous Stomatitis

“…Using the software tool LEfSe [35], we discovered the genus Malassezia to be highly enriched in patients with an active RAS ulcer, which is consistent with the hypothesis of microbial shift in favor of opportunistic pathogens. This observation is also in line with published data connecting the presence of Malassezia with incidence of other diseases, including dandruff, seborrheic dermatitis, and psoriasis [36][37][38][39][40]. The second most abundant species in the Active RAS cohort was Candida albicans, often described either as a commensal or opportunistic pathogen in the oral cavity [34,41].…”

Precipitation of free fatty acids generated by Malassezia – a possible explanation for the positive effects of lithium succinate in seborrhoeic dermatitis

“…reported an increased phosholipase activity in Malassezia species isolated from lesional skin of seborrhoeic dermatitis (SD) after exposure to β‐endorphin . These results are well in line with the observation that the ability of Malassezia yeasts to induce flares of SE is probably strain and not species specific . To underline our results those more virulent strains might be tested in our assay in a further study.…”

“…24 These results are well in line with the observation that the ability of Malassezia yeasts to induce flares of SE is probably strain and not species specific. 25,26 To underline our results those more virulent strains might be tested in our assay in a further study.…”

Malassezia Intra-Specific Diversity and Potentially New Species in the Skin Microbiota from Brazilian Healthy Subjects and Seborrheic Dermatitis Patients

“…Despite the recent increase of studies focusing on Malassezia sp., little is still known concerning Malassezia genetic diversity. It has been proposed that specific Malassezia genotypes might be associated with skin diseases, such as atopic dermatitis [ 23 ] and also SD [ 24 , 25 ]. Moreover, limited information is available regarding Malassezia microbiota in Brazilian subjects based on molecular data.…”