Poster (Painel)
482-1Analysis of the variation over time of scalp microbiota in healthy individuals and patients with seborrheic dermatitis under topical antifungal treatment
Autores:Marcelo Bergamin Zani (CCNH - UFABC - Centro de Ciências Naturais e Humanas, UFABC) ; Renan Cardoso Soares (CCNH - UFABC - Centro de Ciências Naturais e Humanas, UFABC) ; Ana Carolina Belini Bazan Arruda (DHMCP - PUC CAMPINAS - Dermatologia do Hospital e Maternidade Celso Pierro) ; Lucia Helena Favaro de Arruda (DHMCP - PUC CAMPINAS - Dermatologia do Hospital e Maternidade Celso Pierro) ; Luciana Campos Paulino (CCNH - UFABC - Centro de Ciências Naturais e Humanas, UFABC)


The human skin harbors a complex ecosystem composed of fungi and bacteria. Although members of healthy skin microbiota, yeasts from Malassezia genus have been associated with skin disorders such as seborrheic dermatitis (SD). This chronic inflammatory disease more commonly affects the scalp, face, and chest, causing scaling and pruritis. Fungal and bacterial microbiotas possibly establish an ecological equilibrium, in such a way that variation in one population might influence the other. The aim of this study is to analyze the scalp microbiota of healthy individuals and patients with SD, evaluating composition and variation over a two-month period. Three scalp samples from two healthy individuals and from two patients with SD were obtained using sterile cotton swabs, at 1-month intervals. In the case of the patients, samples were obtained before, during and after treatment with an antifungal shampoo containing 2% ketoconazole and 1% salicylic acid. Quantitative real time PCR was used to detect and to quantify Malassezia globosa, a species frequently associated with SD, and Propionibacteirum sp., a bacterial genus commonly found in human skin. The total amount of bacteria was also evaluated. Results showed that the total amounts and the proportion between the organisms differed among subjects, regardless of their health status. The total amount of M. globosa in both patients under treatment decreased in the first month, which was accompanied by the improvement of symptoms. However, a small increase of M. globosa was observed in the second month, when both patients reached similar quantities. Bacterial population also fluctuated over the two-month period, although the variation profile differed among patients. In contrast, both fungal and bacterial populations from healthy individuals seemed to be stable over the period of time analyzed. Our results contribute to the understanding of the dynamic of scalp microbiota in health and SD, and of the involvement of microorganisms in the pathogenic process of this disease. Financial support: Fapesp (proc. no. 2008/08183-9), UFABC

Palavras-chave:  Malassezia, Quantitative analysis, qPCR, Seborrheic dermatitis, Human microbiota