RESUMO

The present study evaluated whether the oxidative stress caused by antimicrobial photodynamic therapy (aPDT) affects the expression of C. albicans genes related to adhesion and biofilm formation (ALS1 and HPW1) and oxidative stress response (CAP1, CAT1, and SOD1). The aPDT was mediated by two photosensitizing agents (PSs) Photodithazine® (PDZ at 100 and 200 mg/L) or Curcumin (CUR at 40 and 80 µM) and LED (37.5 J/cm2 or 50 J/cm2). The quantification of the expression was performed by Reverse Transcription-Quantitative Polymerase Chain Reaction (RT-qPCR) using specific primers for the target genes. The data were analyzed by Analysis of Variance (α = 0.05), followed by Tukey's post-test. It was observed reduction in the expression of ALS1, HWP1, CAP1, CAT1, and SOD1 when aPDT was performed using 200 mg/L PDZ and 80 µM CUR associated to LED (37.7 and 50 J/cm2, respectively) and using 100 mg/L PDZ and 40 µM CUR with LED of 50 J/cm2 (versus control). Also, the expression of CAP1 and SOD1 genes was reduced after aPDT using 100 mg/L PDZ and LED of 37.5 J/cm2. There was a significant reduction in the expression of genes HWP1, CAP1, and SOD1 after aPDT using 40 µM CUR and 37.5 J/cm2 (versus the control group). The application of LED only at 37.5 and 50 J/cm2 promoted down-regulation of ALS1, CAP1, CAT1, and SOD1 genes (versus the control group). Therefore, aPDT mediated by LED -associated PSs PDZ and CUR promoted a reduction in the expression of the five C. albicans genes evaluated.

Assuntos

Anti-Infecciosos , Fotoquimioterapia , Biofilmes , Candida albicans/genética , Expressão Gênica , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico

RESUMO

Candida albicans oral strains collected from caries-free and caries-active healthy children ranging from 24 to 36 months old, were studied. The aim of the study was to determine proteinase and phospholipase activities produced by Candida albicans in the two groups and to determine the phenotypic diversity of these enzymes based on genetic polymorphism using the AP-PCR method. Strains identified by morphological and fermentation tests as C. albicans were grown in proteinase and phospholipase agar media at 37ºC for 7 and 4 days, respectively. After the incubation period, the enzyme activity of the proteinase and phospholipase positive strains was measured. All strains were subjected to AP-PCR, using the arbitrary primer AP-3. The enzymatic analysis showed no differences between the two groups. The AP-PCR method was effective in demonstrating intra-individual genetic polymorphism in C. albicans, showing a greater clonal diversity in caries-active versus caries-free children. Dendograms of similarity showed only intra-individual clonal lineage. The results suggest that the enzymatic profile does not depend on the genotypic characteristics of the strains.

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Cepas orais de Candida albicans coletadas de crianças saudáveis cárie ativas e livres de cárie com idade variando de 24 a 36 meses, foram estudadas. O propósito do estudo foi determinar a atividade da proteinase e da fosfolipase produzida por Candida albicans nos dois grupos e comparar com a diversidade genotípica usando o método AP-PCR. As cepas identificadas como C. albicans por testes morfológicos e de fermentação, foram cultivadas em meio ágar proteinase e fosfolipase a 37ºC por 7 e 4 dias, respectivamente. Após o período de incubação, a atividade enzimática das cepas proteinase e fosfolipase positiva foram medidas. Todas as cepas foram submetidas a técnica genotípica AP-PCR, usando o primer arbitrário AP-3. A análise enzimática demonstrou que não há diferença entre os dois grupos estudados. O método AP-PCR foi eficiente em demonstrar o polimorfismo genético de C. albicans intra indivíduos demonstrando uma maior diversidade clonal em crianças cárie ativas em relação as livres de cárie. Dendogramas de similaridade demonstraram semelhança na linhagem clonal apenas intra-indivíduos. Os resultados sugerem que o perfil enzimático não depende das características genotípicas das cepas.