Abstract Fungal infections have become a concern for health professionals, and the emergence of resistant strains has been reported for all known classes of antifungal drugs. Among the fungi causing disease, we highlight those that belong to the genus Aspergillus. For these reasons, the search for new antifungals is important. This study examines the effects of a coumarin derivative, 4-acetatecoumarin (Cou-UMB16) both alone and together with antifungal drugs, and its mode of action against Aspergillus spp. Cou-UMB16 was tested to evaluate its effects on mycelia growth, and germination of Aspergillus spp. fungal conidia. We investigated its possible action on cell walls, on the cell membrane, and also the capacity of this coumarin derivative to enhance the activity of antifungal drugs. Our results suggest that Cou-UMB16 inhibits Aspergillus spp. virulence factors (mycelia growth and germination of conidia) and affects the structure of the fungal cell wall. When applying Cou-UMB16 in combination with azoles, both synergistic and additive effects were observed. This study concludes that Cou-UMB16 inhibits mycelial growth and spore germination, and that the activity is due to its action on the fungal cell wall, and that Cou-UMB16 could act as an antifungal modifier.

A phytochemical investigation from aerial parts of Casearia arborea (Rich.) Urb. (Salicaceae) led to isolation and identification of: sitosterol, 4-en-stigmast-3-one, 13-hydroxy-trans-ent-cleroda-3,14-diene,3-hydroxy-2-oxo-trans-ent-cleroda-3,14-diene (kolavelone), a mixture of 13-hydroxy-trans-ent-cleroda-3,14-diene and an ester ethyl hexadecanoate, kaempferol-3-O-a-L-arabinofuranoside and 4',5,7-trihydroxy-3',5'-dimethoxyflavone (tricin). The compounds have been described for the first time in this species. Five trihydroxy-flavone-hexoside derivatives have been identified by LC-ESI-HR-MS. The antimicrobial activity of kolavelone was evaluated against strains of Staphylococcus, Bacillus, Pseudomonas, Shigella and Candida spores, and its minimum inhibitory concentration (MIC) was determined. The results showed the antimicrobial activity of kolavelone against several bacteria and Candida tropicalis indicating its potential use as antimicrobial agent.

RESUMOAo longo do tempo, se modificou a etiologia das onicomicoses, leveduras do gênero Candida têm emergido como agentes etiológicos importantes. O objetivo desse trabalho foi determinar a frequência de onicomicoses causadas por leveduras em João Pessoa, Paraíba, Brasil de 1999 a 2010. Um estudo retrospectivo de janeiro de 1999 a dezembro de 2010 avaliou os resultados de exames micológicos diretos (EMD) positivos para leveduras provenientes de onicomicoses, realizados no Laboratório Clínico Hemato(r). As mulheres foram as mais afetadas por onicomicoses, as unhas dos pés são os alvos preferidos e ocorrem preferencialmente em adultos. As leveduras prevalentes foram Candida tropicalis e C. krusei.

ABSTRACTOver time, as the etiology of onychomycosis has developed, yeasts from the genus Candida have emerged as important etiological agents. This study aimed to determine the frequency of yeast caused onychomycosis in Joao Pessoa, Paraíba, Brazil from 1999 to 2010. A retrospective study from January 1999 to December 2010 evaluated the results of onychomycosis positive direct mycological exams (DME) - for yeast and realized in the Hemato(r) Clinical Laboratory. Women were the most affected by onychomycosis which occur preferentially in adults, and the toenails are the favorite yeast targets. The prevalent yeasts were Candida tropicalis and C. krusei.

O objetivo deste estudo foi observar a eficácia do óleo essencial de O. vulgare L. e O. majorana L. na inibição do crescimento e sobrevivência de cepas de fungos potencialmente patogênicas, bem como avaliar os possíveis mecanismos envolvidos no estabelecimento da propriedade antifúngica dos óleos essenciais testados através do ensaio de estabilidade osmótica e morfogênese. As cepas fúngicas utilizadas neste estudo foram Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 e Cladosporium herbarium ATCC 26362. O óleo essencial de O. vulgare apresentou valor de CIM de 80 µL/mL, enquanto o óleo essencial de O. majorana apresentou valor de CIM de 160 µL/mL. C. krusei LM-09 apresentou-se como a única cepa resistente a todas as concentrações ensaiadas de ambos os óleos essenciais. Os óleos essenciais testados quando ensaiadas em seu valor de CIM causaram um efeito fungicida contra C. albicans ATCC 7645 após 4 h de exposição. O óleo essencial de O. vulgare na concentração de 80 µL/mL exibiu uma total inibição do crescimento micelial radial de T. rubrum ATCC 28184 e M. canis LM-36 ao longo de 14 dias. As cepas fúngicas ensaiadas quando tratadas com sorbitol (agente osmo-protetor) foram capazes de crescer em meio adicionado de mais altas concentrações dos óleos essenciais quando comparados ao meio não adicionado de sorbitol, sugerindo especificidade destes produtos a parede celular como alvo na célula fúngica. As principais alterações causadas pelo óleo essencial de O. vulgare sobre a morfologia de A. flavus LM-02 foram diminuída conidiação, perda de citoplasma, perda de pigmentação e ruptura da estrutura celular indicando degeneração da parede celular fúngica. Estes resultados sugerem que óleos essenciais de espécies de Origanum poderiam ser considerados como potenciais antifúngicos para o controle de fungos patógenos e ocorrência de micoses.

This study aimed to assess the efficacy of O. vulgare L. and O. majorana L. essential oil in inhibiting the growth and survival of potentially pathogenic fungal strains and also sought to evaluate the possible mechanisms involved in the establishment of the antifungal property of the tested essential oils through assays of osmotic stability and morphogenesis. Test strains included in this study were Candida albicans ATCC 7645, C. tropicalis LM-14, C. krusei LM-09, Cryptococcus neoformans FGF-5, Aspergillus flavus LM-02, A. fumigatus IPP-21, T. rubrum ATCC 28184, T. mentagrophytes LM-64, Microsporum gypseum ATCC 184, M. canis LM-36 and Cladosporium herbarium ATCC 26362. O. vulgare essential oil presented a MIC value of 80 µL/mL, while for O. majorana this was 160 µL/mL. C. krusei LM-09 was the only strain resistant to all assayed concentrations of both essential oils. O. vulgare and O. majorana essential oil at their MIC values provided a cidal effect against C. albicans ATCC 7645 after 4 h of exposure. O. vulgare essential oil at 80 µL/mL exhibited 100 % inhibition of the radial mycelia growth of T. rubrum ATCC 28184 and M. canis LM-36 for 14 days. Assayed fungus strain protected by sorbitol (osmo-protectant agent) grew in media containing higher concentrations of O. vulgare and O. majorana essential oil in comparison to media without sorbitol, suggesting some specificity of these essential oils for targeting cell wall in the fungi cell. Main morphological changes observed under light microscopy provided by the essential oil of O. vulgare in A. flavus LM-02 were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. These results suggest that essential oils from Origanum could be regarded as a potential antifungal compound for controlling the growth of pathogen fungi and the occurrence of mycoses.