Investigação da presença de fungos dermatófitos em praias de Salvador, Bahia / Investigation of dermatophyte fungi on Salvador’s beaches, Bahia

Dermatofitoses são infecções fúngicas superficiais que acometem animais domésticos e homens, nas quais fungos dermatófitos colonizam tecidos queratinizados. A infecção se propaga através do contato direto com o indivíduo infectado ou por um utensilio de uso comum, podendo também ocorrer a transmissão através do contato com o solo contaminado, em locais como parques e praias. Sendo assim, o estudo analisou a presença destes microrganismos nas praias da cidade de Salvador, no período entre agosto de 2018 e julho de 2019. Foram feitas coletas de areia de 19 praias que fazem parte da orla da cidade. O material coletado foi processado em laboratório por dois métodos diferentes, técnica da isca e cultura da suspensão do material, sendo posteriormente incubadas em estufa de Demanda Biológica de Oxigênio (BDO) à 28°C, por até 20 dias. A presença de dermatófitos não foi verificada em nenhuma das amostras coletadas, demonstrando a boa qualidade sanitária das áreas analisadas. Esses resultados apresentam uma divergência em relação aos achados de alguns estudos publicados na literatura em relação a outras áreas, podendo-se observar a existência de outras variáveis do ambiente que podem influenciar nos resultados, tal qual o fluxo de pessoas e animais no ambiente. Sendo assim, são necessárias mais pesquisas que analisem em um número amostral mais extenso a presença desses fungos nas areias de praias, bem como os fatores que favorecem a contaminação do ambiente, com o intuito final de estabelecer um valor máximo de UFC/g de areia que retrate a qualidade da mesma para este requisito

Protocol for evaluating the in vitro effect of violet light-emitting diodes (LEDs) 410 nm ± 10 nm on yeast cultures

BACKGROUND: Candida spp and Malassezia spp cause superficial infections that may be resistant to conventional treatments. Violet light-emitting diodes (LEDs) therapy is a therapeutic alternative. PURPOSE: To describe the protocol for evaluating the antifungal effect of violet LEDs 410 nm ± 10 nm on Candida spp and Malassezia spp in vitro. PROTOCOL: LEDs 410 nm ± 10 nm are applied to a fungal suspension at fluences of 61.13 J/cm2, 91.70 J/cm2, and 183.39 J/cm2. The isolates are cultured for 48 to 72 hours. Colony forming units (CFUs) are quantified by visual counting and percent culture plate occupancy by digital analysis. Morphology is assessed by light microscopy and Gram staining, and yeast metabolism/function by transmission electron microscopy, assessment of reactive oxygen species, and DNA fragmentation. DATA ANALYSIS: the percentage of LEDs inhibition is calculated considering the growth of the negative control condition and the percentage of plate occupancy by yeasts by dividing the number of pixels classified as colonies by the total number of pixels on the plate. The morphological and functional aspects are described for the intervention and negative control. The ANOVA test is used to compare the mean percentages of growth inhibition and plate occupancy between the three fluences of LEDs 410 nm ± 10 nm and the negative control. ESTIMATED RESULTS: We intend to determine the antifungal effect of the different fluences of LEDs 410 nm ± 10 nm on Candida spp and Malassezia spp. The evaluation of other fungal species by this protocol should be investigated

Leishmanicidal Metabolites from Cochliobolus sp., an Endophytic Fungus Isolated from Piptadenia adiantoides (Fabaceae)

Protozoan parasites belonging to genera Leishmania and Trypanosoma are the etiological agents of severe neglected tropical diseases (NTDs) that cause enormous social and economic impact in many countries of tropical and sub-tropical areas of the world. In our screening program for new drug leads from natural sources, we found that the crude extract of the endophytic fungus Cochliobolus sp. (UFMGCB-555) could kill 90% of the amastigote-like forms of Leishmania amazonensis and inhibit by 100% Ellman's reagent reduction in the trypanothione reductase (TryR) assay, when tested at 20 µg mL−1. UFMGCB-555 was isolated from the plant Piptadenia adiantoides J.F. Macbr (Fabaceae) and identified based on the sequence of the internally transcribed spacer (ITS) regions of its ribosomal DNA. The chromatographic fractionation of the extract was guided by the TryR assay and resulted in the isolation of cochlioquinone A and isocochlioquinone A. Both compounds were active in the assay with L. amazonensis, disclosing EC50 values (effective concentrations required to kill 50% of the parasite) of 1.7 µM (95% confidence interval = 1.6 to 1.9 µM) and 4.1 µM (95% confidence interval = 3.6 to 4.7 µM), respectively. These compounds were not active against three human cancer cell lines (MCF-7, TK-10, and UACC-62), indicating some degree of selectivity towards the parasites. These results suggest that cochlioquinones are attractive lead compounds that deserve further investigation aiming at developing new drugs to treat leishmaniasis. The findings also reinforce the role of endophytic fungi as an important source of compounds with potential to enter the pipeline for drug development against NTDs