Antimicrobial action of four herbal plants over mixed-species biofilms of Candida albicans with four different microorganisms.

This study aimed to evaluate the antimicrobial effect of four herbal plants glycolic extracts over mixed-species biofilm composed of Candida albicans (C. albicans) and another pathogenic bacterium as alternative therapy to be investigated. Four plants extract of Pfaffia paniculata roots; Hamamelis virginiana leaf, Stryphnodendron barbatiman tree bark and Gymnema sylvestre stem and leaves were tested over multi-species biofilm of C. albicans (ATCC 18804) and Streptococcus mutans (ATCC 35688), Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 4083) or Pseudomonas aeruginosa (ATCC 15442) for 5 min and 24 h and colony forming units per millilitre was calculated. The data were analysed using Kruskal-Wallis with Dunn's test (p ≤ 0.05). All tested extracts showed antimicrobial action over the mixed-species biofilms after 24 h. Some extracts eliminated totally the biofilms. The glycolic extract of P. paniculata, H. virginiana, S. barbatiman and G. sylvestre are effective over mixed-species biofilms and may be indicated as endodontic irrigant or intracanal medication.

Cleaning and Surface Treatment Protocols for Repair of Aged Y-TZP with Composite Resin.

The purpose of this study was to evaluate the cleaning and surface treatment techniques in the repair of aged and contaminated yttrium oxide-stabilized tetragonal polycrystalline zirconia (Y-TZP). From a total of 80 specimens of Y-TZP, 60 were subjected to aging simulation in a buccal environment with degradation in an autoclave for 24 hours (127°C/1.5 bar) and contaminated with Streptococcus mutans. The surfaces were cleaned with a triple syringe (air/water jet; n = 20) or isopropyl alcohol (n = 20), or by prophylaxis (n = 20) with pumice and water. The remaining 20 specimens comprised the control group. All specimens were then treated with silicatization (n = 10 per group) or adhesive (n = 10 per group) and repaired with composite resin. Analyses of shear strength, failure mode, and roughness were performed by electron microscopy. Data were analyzed by two-way analysis of variance (ANOVA) and t test (α = .05). Statistical significance was set at P < .05. Two-way ANOVA was significant for aging and surface treatments (P = .049), but was not significant for surface cleaning (P = .05). ANOVA results were statistically significant for surface treatments (P < .0001), with higher resistance for the silicatization groups. The failure mode was mostly adhesive for all specimens. The roughness was not significant for aging and control groups (P > .05). Triple-syringe and prophylaxis cleansing followed by silicatization was the most efficient treatment for the repair of aged and contaminated Y-TZP. There is reduced repair efficiency with the aging of Y-TZP.

Influence of Streptococcus mitis and Streptococcus sanguinis on virulence of Candida albicans: in vitro and in vivo studies.

The aim was to evaluate in vitro possible interactions, gene expression, and biofilm formation in species of Candida albicans, Streptococcus mitis, and Streptococcus sanguinis and their in vivo pathogenicity. The in vitro analysis evaluated the effects of S. mitis and S. sanguinis on C. albicans's biofilm formation by CFU count, filamentation capacity, and adhesion (ALS1, ALS3, HWP1) and transcriptional regulatory gene (BCR1, CPH1, EFG1) expression. In vivo studies evaluated the pathogenicity of the interaction of the microorganisms on Galleria mellonella, with analyses of the CFU per milliliter count and filamentation. In vitro results indicated that there was an observed decrease in CFU (79.4-71.5%) in multi-species biofilms. The interaction with S. mitis inhibited filamentation, which seems to increase its virulence factor with over-expression of genes ALS1, ALS3, and HWP1 as well the interaction with S. sanguinis as ALS3 and HWP1. S. mitis upregulated BRC1, CPH1, and EFG1. The histological images of in vivo study indicate an increase in the filamentation of C. albicans when in interaction with the other species. It was concluded that S. mitis interaction suggests increased virulence factors of C. albicans, with periods of lower virulence and proto-cooperation in the interaction with S. sanguinis.

Biofilms of Candida albicans and Streptococcus sanguinis and their susceptibility to antimicrobial effects of photodynamic inactivation.

This study evaluated the effects of photodynamic inactivation (PDI) on single and multi-species biofilms, compounds by Candida albicans and Streptococcus sanguinis. Biofilms were formed, on microplate of 96 wells, by suspensions of C. albicans (ATCC 18804) and S. sanguinis (ATCC 7073) adjusted in 107 cells/mL, followed by incubation of 48 h (with 5% CO2). The effects of the photosensitizer erythrosine (ER) at 400 µM for 5 min and green light-emitting diode (LED - 532 ±â€¯10 nm) for 3 min, alone and conjugated, were evaluated. After normality test, results was analysed by Tukey´s test (P < 0.05). PDI group promoted reductions of 1.07 and 0.39 log10, respectively, in biofilms of C. albicans alone and in association with S. sanguinis. Biofilms of S. sanguinis alone were more sensitive, with reduction of 4.48 log10. When in association with the yeast, S. sanguinis have a decrease of 2.67 log10. SEM analysis revealed a decrease in bacterial and fungal structures of biofilms treated with PDI. In conclusion PDI promoted significant microbial reductions in both species of microorganisms grown on mixed biofilms. This study is one of the pioneers to evaluate the antimicrobial action of PDI on biofilms of S. sanguinis and C. albicans, demonstrating a way to control these microorganisms of clinical importance.

Avaliação de extratos de plantas medicinais em biofilmes multiespécie de Candida albicans com Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis e Pseudomonas aeruginosa / Evaluation of extracts of medicinal plants in biofilm multispecies of Candida albicans with Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis e Pseudomonas aeruginosa

Os micro-organismos estão cada vez mais resistentes aos medicamentos disponíveis tanto na medicina quanto na odontologia, e esta resistência é ainda maior quando estão organizados em biofilmes mono ou multiespécies, de modo que o estudo de antimicrobianos alternativos, como fitoterápicos, estão em crescente ascensão. A interação entre leveduras e bactérias está intimamente presente na cavidade bucal, em que nichos como dentes, língua, mucosa e bolsa periodontal, nutrientes e temperatura adequados promovem condições favoráveis para formação do biofilme. Com isso, o objetivo deste trabalho foi avaliar a atividade antimicrobiana dos extratos de Pfaffia paniculata K (pfaffia), Hamamelis virginiana L. (hamamelis), Stryphnodendron barbatiman (barbatimão) e Gymnema sylvestre (gimena) em biofilmes heterotípicos de Candida albicans (ATCC 18804) com Streptococcus mutans (ATCC 35688), Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 4083) e Pseudomonas aeruginosa (ATCC 15442). Para isso, suspensões padronizadas em 107 cels/mL dos micro-organismos testes, foram distribuídos em placas de microtitulação de 96 poços, juntamente 100 µL de caldo BHI. As placas foram incubadas em estufa bacteriológica a 37ºC/48h (5% de CO2 para S. mutans) e, após, os biofilmes foram submetidos ao tratamento com os extratos por 5 min e 24 h, nas respectivas concentrações de 100 mg/mL, 50 mg/mL e 25 mg/mL. Foi utilizado solução salina 0,9% (5 min) ou caldo BHI (24 h) nos grupos controles. Após, os biofilmes foram lavados e desagregados do fundo da placa e diluições seriadas foram semeadas em ágar seletivo para cada micro-organismo. Foram realizadas contagens de UFC/mL (log10) após 24 h de incubação e analisadas estatisticamente pelo método Kruskal-Wallis suplementado pelo teste de Dun's (p<0.05). Os resultados obtidos indicaram reduções significativas promovidas pelos extratos nos dois tempos de tratamento analisados. Foi observado que o extrato de H. virginiana apresentou redução de todos os grupos analisados no tempo de tratamento de 24 h. Conclui-se que os extratos de P. paniculata, H. virginiana, S. barbatiman e G. sylvestre apresentaram ação antimicrobiana sobre biofilmes muliespécie de C. albicans com as bactérias de interesse médico-odontológico, nos tempos de tratamento de 5 min e 24 h. (AU)

Microorganisms are increasingly resistant to drugs available in both medicine and dentistry, and this resistance is even greater when they are organized into mono or multispecies biofilms, so that the study of alternative antimicrobials, such as herbal medicines, are on the rise. The interaction between yeasts and bacteria is intimately present in the oral cavity, in which niches such as teeth, tongue, mucosa and periodontal pocket, food and adequate temperature promote adequate conditions for biofilm formation. The aim of this study was to evaluate the antimicrobial activity of extracts of Pfaffia paniculata K., Hamamelis virginiana L., Gymnema sylvestre and Stryphnodendron barbatiman M. in heterotopic biofilms of Candida albicans (ATCC 18804) with Streptococcus mutans (ATCC 35688). Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 4083), and Pseudomonas aeruginosa (ATCC 15442). Standardized suspensions at 107 cells/mL of the test microorganisms were distributed in 96 well microtiter plates together with 100 µL of BHI broth, the plates were incubated in a bacteriological oven at 37°C/48h (5% CO2 for S. mutans). After the incubation time, treatments were performed at 5 min and 24 h times, applying the respective extracts at the concentrations of 100 mg, 50 mg and 25 mg/mL and applying 0.9% saline solution or BHI broth in the control groups. After the biofilms were washed and disaggregated from the bottom of the plate, performing serial dilutions for later seeding in selective agar. UFC/ml (log10) counts were performed after 24 h of incubation and statistically analyzed Kruskal-Wallis method supplemented by the Dun's test (p<0.05%). The obtained results indicated significant reductions promoted by extracts in the two treatment times analyzed. It was observed that the extract of H. virginiana showed reduction of all the analyzed groups without treatment time of 24 h. It is concluded that the extracts of P. paniculata, H. virginiana, S. barbatiman and G. sylvestre presented antimicrobial action after analysis of the heterotypic biofilms of C. albicans with the bacteria of medical and dental interest, in the treatment times of 5 min and 24 h. (AU)

Production of virulence factors in Candida strains isolated from patients with denture stomatitis and control individuals.

The aim of this study was to evaluate the production of virulence factors in Candida isolates from the oral cavities of 50 patients with different degrees of denture stomatitis (DS, type I, II and III) and 50 individuals without signs of DS. We evaluated the enzymatic and hemolytic activities, the biofilm formation, and the cell surface hydrophobicity (CSH) in all isolates. Germ tube (GT) production was also evaluated in Candida albicans and Candida dubliniensis isolates. In C. albicans and C. dubliniensis the secretion of hemolysin and GT production was significantly different between isolates from patients with DS and individuals without DS. No significant difference was observed in the production of virulence factors by Candida glabrata isolates. Candida isolates expressed a wide range of virulence factors. However, in the majority of isolates from the type III lesions, the production of the virulence factors was higher than for the other groups.

Photodynamic inactivation of virulence factors of Candida strains isolated from patients with denture stomatitis.

Candida species are major microorganisms isolated in denture stomatitis (DS), an inflammatory process of the mucosa underlying removable dental prostheses, and express a variety of virulence factors that can increase their pathogenicity. The potential of Photodynamic inactivation (PDI) in planktonic culture, biofilms and virulence factors of Candida strains was evaluated. A total of 48 clinical Candida isolates from individuals wearing removable maxillary prostheses with DS were included in the study. The effects of erythrosine (ER, 200 µM) and a green LED (λ 532 ± 10 nm, 237 mW/cm(2) and 42.63 J/cm(2)) in a planktonic culture were evaluated. The effect of the addition of ER at a concentration of 400 µM together with a green LED was evaluated in biofilms. The virulence factors of all of the Candida strains were evaluated before and after the PDI process in cells derived from biofilm and planktonic assays. All of the Candida species were susceptible to ER and green LED. However, the biofilm structures were more resistant to PDI than the planktonic cultures. PDI also promoted slight reductions in most of the virulence factors of C. albicans and some of the Candida tropicalis strains. These results suggest that the addition of PDI is effective for reducing yeasts and may also reduce the virulence of certain Candida species and decrease their pathogenicity.