Quorum sensing (QS) regulates bacterial gene expression and studies suggest quercetin, a flavonol found in onion, as a QS inhibitor. There are no studies showing the anti-QS activity of plants containing quercetin in its native glycosylated forms. This study aimed to evaluate the antimicrobial and anti-QS potential of organic extracts of onion varieties and its representative phenolic compounds quercetin aglycone and quercetin 3-β-D-glucoside in the QS model bacteria Chromobacterium violaceum ATCC 12472, Pseudomonas aeruginosa PAO1, and Serratia marcescens MG1. Three phenolic extracts were obtained: red onion extract in methanol acidified with 2.5% acetic acid (RO-1), white onion extract in methanol (WO-1) and white onion extract in methanol ammonium (WO-2). Quercetin 4-O-glucoside and quercetin 3,4-O-diglucoside were identified as the predominant compounds in both onion varieties using HPLC-DAD and LC-ESI-MS/MS. However, quercetin aglycone, cyanidin 3-O-glucoside and quercetin glycoside were identified only in RO-1. The three extracts showed minimum inhibitory concentration (MIC) values equal to or above 125 µg/ml of dried extract. Violacein production was significantly reduced by RO-1 and quercetin aglycone, but not by quercetin 3-β-D-glucoside. Motility in P. aeruginosa PAO1 was inhibited by RO-1, while WO-2 inhibited S. marcescens MG1 motility only in high concentration. Quercetin aglycone and quercetin 3-β-D-glucoside were effective at inhibiting motility in P. aeruginosa PAO1 and S. marcescens MG1. Surprisingly, biofilm formation was not affected by any extracts or the quercetins tested at sub-MIC concentrations. In silico studies suggested a better interaction and placement of quercetin aglycone in the structures of the CviR protein of C. violaceum ATCC 12472 than the glycosylated compound which corroborates the better inhibitory effect of the former over violacein production. On the other hand, the two quercetins were well placed in the AHLs binding pockets of the LasR protein of P. aeruginosa PAO1. Overall onion extracts and quercetin presented antimicrobial activity, and interference on QS regulated production of violacein and swarming motility.
The expression of virulence factors was higher in FLC-R-C. tropicalis and it was enhanced after FLC-exposure. These data alert us to the importance of identifying microorganisms that show resistance to the antifungals to establish an appropriate management of candidiasis therapy.
A onicomicose é uma doença caracterizada pela infecção de fungos em uma ou mais unhas, infecção essa que pode ser causada por fungos dermatófitos ou não, que necessita de diagnóstico precoce e atendimento qualificado para que haja um resultado efetivo em seu tratamento. Entender quais são as principais características dessa patologia, assim como, as técnicas de identificação do microrganismo na região ungueal, de forma com que os profissionais da área da saúde, quando estiverem frente ao tratamento desta, saibam qual técnica de pesquisa laboratorial melhor se enquadra e a que menos apresenta chance de um resultado falso negativo, é o foco deste estudo. O foco é diminuir as doenças co-relacionadas com esta infecção, como o contagio de outras pessoas circundantes a este paciente potencialmente contaminado, e a utilização de métodos tópicos para tratamento da doença.
A Psoríase é dermatose autoimune que atinge aproximadamente de 3% da população mundial, sendo que cerca de 80% dos portadores apresentam o acometimento ungueal. Atualmente não existem trabalhos propondo uma abordagem podológica no tratamento de portadores de Psoríase ungueal. Desta maneira o objetivo deste trabalho além de preencher esta lacuna, é elucidar a fisiopatologia da Psoríase, compilar os sinais clínicos característicos da manifestação ungueal e citar métodos de diagnóstico e de avaliação da mesma. O objetivo específico deste estudo é propor uma abordagem podológica para portadores de Psoríase ungueal. Este estudo caracterizou-se como uma revisão de literatura. Foram realizadas buscas sistemáticas no período entre Junho e setembro de 2016, utilizando bancos de dados eletrônicos como: Medline, Science Direct, Directory of Open Access Journals (DOAJ), Scientific Eletronic Library Online (SciELO).
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