Characterization of the Oral Fungal Microbiome (Mycobiome) in Healthy Individuals

The oral microbiome–organisms residing in the oral cavity and their collective genome–are critical components of health and disease. The fungal component of the oral microbiota has not been characterized. In this study, we used a novel multitag pyrosequencing approach to characterize fungi present in the oral cavity of 20 healthy individuals, using the pan-fungal internal transcribed spacer (ITS) primers. Our results revealed the “basal” oral mycobiome profile of the enrolled individuals, and showed that across all the samples studied, the oral cavity contained 74 culturable and 11 non-culturable fungal genera. Among these genera, 39 were present in only one person, 16 genera were present in two participants, and 5 genera were present in three people, while 15 genera (including non-culturable organisms) were present in ≥4 (20%) participants. Candida species were the most frequent (isolated from 75% of participants), followed by Cladosporium (65%), Aureobasidium, Saccharomycetales (50% for both), Aspergillus (35%), Fusarium (30%), and Cryptococcus (20%). Four of these predominant genera are known to be pathogenic in humans. The low-abundance genera may represent environmental fungi present in the oral cavity and could simply be spores inhaled from the air or material ingested with food. Among the culturable genera, 61 were represented by one species each, while 13 genera comprised between 2 and 6 different species; the total number of species identified were 101. The number of species in the oral cavity of each individual ranged between 9 and 23. Principal component (PCO) analysis of the obtained data set followed by sample clustering and UniFrac analysis revealed that White males and Asian males clustered differently from each other, whereas both Asian and White females clustered together. This is the first study that identified the “basal mycobiome” of healthy individuals, and provides the basis for a detailed characterization of the oral mycobiome in health and disease

Aspectos micológicos e suscetibilidade in vitro de leveduras do gênero Candida em pacientes HIV-positivos provenientes do Estado de Mato Grosso Mycological aspects and susceptibility in vitro the yeast of the genus Candida from HIV-positive patients in the State of Mato Grosso

INTRODUÇÃO: A candidíase é uma das infecções fúngicas mais frequentes entre os pacientes infectados pelo vírus da imunodeficiência humana. O presente estudo objetivou a caracterização das leveduras do gênero Candida de distintas amostras clínicas, provenientes de pacientes HIV - positivos, assim como a determinação do perfil de suscetibilidade in vitro a cinco drogas antifúngicas. MÉTODOS: A caracterização dos isolados de Candida sp foi realizada através da metodologia clássica, testes bioquímicos (zimograma e auxanograma) e morfológicos (prova do tubo germinativo e microcultivo em lâmina). Também, foram realizadas a técnica genotípica (PCR) e identificação pelo método comercial API 20C AUX (BioMeriéux). Para a determinação do perfil de suscetibilidade in vitro, foram utilizadas cinco drogas antifúngicas (cetoconazol, fluconazol, itraconazol, voriconazol e anfotericina B), através do método comercialmente disponível - Etest. RESULTADOS: Foram identificados 105 isolados de leveduras do gênero Candida provenientes de 102 pacientes infectados pelo vírus HIV. Destes, foram caracterizadas 82 (78,1%) Candida albicans, 8 (7,6%) Candida parapsilosis, 8 (7,6%) Candida tropicalis, 4 (3,8%) Candida krusei, 2 (1,9%) Candida glabrata e 1 (1%) Candida guilliermondii. CONCLUSÕES: Considerando o perfil geral de sensibilidade, 60% dos isolados foram suscetíveis a todos os antifúngicos testados, porém as espécies C. tropicalis e C. krusei demonstraram uma tendência a valores mais elevados de CIMs para os azóis do que os encontrados paraC. albicans, sugerindo resistência.<br>INTRODUCTION: Candidiasis is one of the most common fungal infections among patients infected by human immunodeficiency virus. The present study aimed to characterize yeasts of the genus Candida from distinct clinical samples from HIV-positive patients and determine the in vitro susceptibility profile to five antifungal drugs. METHODS: Characterization of Candida sp was achieved using the classic methodology: biochemical (zymogram and auxanogram) and micromorphology (germinative tube growth test and slide microculture) tests. Genotypic technique (PCR) and identification by the commercial method API 20C AUX (Biomeriéux) were also performed. To determine the in vitro susceptibility profile, five antifungal drugs were used (ketoconazole, fluconazole, itraconazole, voriconazole and amphotericin-B) following a commercially available method, the Etest. RESULTS: The procedure isolated 105 yeasts of the genus Candida from 102 HIV-infected patients. Of these, 82 (78.1%) were characterized as Candida albicans, 8 (7.6%) as C. parapsilosi s, 8 (7.6%) C. tropicalis, 4 (3.8%) C. krusei, 2 (1.9%) C. glabrata, and 1 (1%) as C. guiilliermondii. CONCLUSIONS: Considering the general profile of sensitivity, 60% of isolates were susceptible to all the antifungal drugs tested; however, the species C. tropicalis and C. krusei showed a tendency toward higher MICs to azoles than those obtained for C. albicans, suggesting resistance