Antimicrobial activity and toxicity of glass ionomer cement containing an essential oil

The aim of this study was to evaluate the antimicrobial activity and toxicity of glass ionomer cement (GIC) modified with 5-methyl-2-(1-methylethyl)phenol (thymol) against Streptococcus mutans in silico and in vitro. The antimicrobial activity of thymol on GIC modified with concentrations of 2% (GIC-2) and 4% (GIC-4) was evaluated in a model of planktonic cell biofilm using agar diffusion test, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), dynamic biofilm (continuous flow cell parallel), and bacterial kinetics. Conventional GIC (GIC-0) was used as a control. Thymol toxicity was evaluated in Artemia salina and in silico using Osiris® software. Differences between groups were estimated by analysis of variance, followed by Tukey post hoc test, with a 5% significance level. The results of the agar diffusion test between groups were not significantly different (P≥0.05). Thymol had potential bacteriostatic and bactericidal activity against Streptococcus mutans with respect to planktonic growth, with MIC of 100 µg/mL and MBC of 400 µg/mL. The groups GIC-0, GIC-2, and GIC-4 reduced the biofilm by approximately 10, 85, and 95%, respectively. Bacterial kinetics showed efficiency of the modified GICs for up to 96 h. GIC with thymol was effective against S. mutans, with significant inhibition of the biofilms. Analyses in silico and using Artemia salina resulted in no relevant toxicity, suggesting potential for use in humans. GIC-2 was effective against S. mutans biofilm, with decreased cell viability.

Deteccao de antigenos bacterianos em pneumonia aguda: metodos de preparacao das amostras de urina, soro e liquido pleural para os testes de imunodiagnostico / Detection of bacterial antigens in acute pneumonia: methods of preparing the urine, serum and pleural fluid samples for immunodiagnostic assays

Foi desenvolvido um metodo de precipitacao de antigenos polissacaridicos de S. pneumoniae e H influenzae tipo b na urina, atraves do tratamento com uma solucao de etnol-acetona 1:1 seguido de um tratamento a quente com EDTA 0,1M. Foram empregadas as tecnicas de contra-imunoeletroforese e latex aglutinacao para a deteccao de antigenos polissacarideos em amostras pareadas de urina e soro e ainda de liquido pleural, de criancas com diagnostico clinico e radiologico de pneumonia aguda. Contra-imunoeletroforese e latex aglutinacao apresentaram melhores indices de sensibilidade em urina do que em soro e tiveram otimo desempenho tanto para urina de volume inicial relativamente pequeno como de grande volume, colhidas antes ou durante os primeiros dias de antibioticoterapia. Os resultados obtidos em contra-imunoeletroforese e latex aglutinacao mostraram que a solucao etanol-acetona 1:1 fornece melhor rendimento na precipitacao de antigeno polissacaridico enquanto que o aquecimento com EDTA diminui a probabilidade de ocorrencia de resultados falso-positivos e de reatividade cruzada entre S. pneumoniae e H. influenzae tipo b. A urina mostrou-se como importante meio de deteccao de antigenos bacterianos no diagnostico de pneumonia bacteriana aguda, principalmente se a antibioticoterapia previa obstrui o crescimento bacteriano nos meios de cultura.