Chitosan microparticles loaded with essential oils inhibit duo-biofilms of Candida albicans and Streptococcus mutans

Oral candidiasis is a common fungal infection that affects the oral mucosa, and happens when Candida albicans interacts with bacteria in the oral microbiota, such as Streptococcus mutans, causing severe early childhood caries. C. albicans and S. mutans mixed biofilms are challenging to treat with conventional antimicrobial therapies, thus, new anti-infective drugs are required. Objective: This study aimed to test a drug delivery system based on chitosan microparticles loaded with geranium and lemongrass essential oils to inhibit C. albicans and S. mutans mixed biofilms. Methodology: Chitosan microparticles loaded with essential oils (CM-EOs) were obtained by spray-drying. Susceptibility of planktonic were performed according CLSI at 4 to 2,048 µg/mL. Mixed biofilms were incubated at 37ºC for 48 h and exposed to CM-EOs at 256 to 4,096 µg/mL. The antimicrobial effect was evaluated using the MTT assay, with biofilm architectural changes analyzed by scanning electron microscopy. RAW 264.7 cell was used to evaluate compound cytotoxicity. Results: CM-EOs had better planktonic activity against C. albicans than S. mutans. All samples reduced the metabolic activity of mixed C. albicans and S. mutans biofilms, with encapsulated oils showing better activity than raw chitosan or oils. The microparticles reduced the biofilm on the slides. The essential oils showed cytotoxic effects against RAW 264.7 cells, but encapsulation into chitosan microparticles decreased their toxicity. Conclusion: This study demonstrates that chitosan loaded with essential oils may provide an alternative method for treating diseases caused by C. albicans and S. mutans mixed biofilm, such as dental caries

Chitosan microparticles loaded with essential oils inhibit duo-biofilms of Candida albicans and Streptococcus mutans

Abstract Oral candidiasis is a common fungal infection that affects the oral mucosa, and happens when Candida albicans interacts with bacteria in the oral microbiota, such as Streptococcus mutans, causing severe early childhood caries. C. albicans and S. mutans mixed biofilms are challenging to treat with conventional antimicrobial therapies, thus, new anti-infective drugs are required. Objective This study aimed to test a drug delivery system based on chitosan microparticles loaded with geranium and lemongrass essential oils to inhibit C. albicans and S. mutans mixed biofilms. Methodology Chitosan microparticles loaded with essential oils (CM-EOs) were obtained by spray-drying. Susceptibility of planktonic were performed according CLSI at 4 to 2,048 µg/mL. Mixed biofilms were incubated at 37ºC for 48 h and exposed to CM-EOs at 256 to 4,096 µg/mL. The antimicrobial effect was evaluated using the MTT assay, with biofilm architectural changes analyzed by scanning electron microscopy. RAW 264.7 cell was used to evaluate compound cytotoxicity. Results CM-EOs had better planktonic activity against C. albicans than S. mutans. All samples reduced the metabolic activity of mixed C. albicans and S. mutans biofilms, with encapsulated oils showing better activity than raw chitosan or oils. The microparticles reduced the biofilm on the slides. The essential oils showed cytotoxic effects against RAW 264.7 cells, but encapsulation into chitosan microparticles decreased their toxicity. Conclusion This study demonstrates that chitosan loaded with essential oils may provide an alternative method for treating diseases caused by C. albicans and S. mutans mixed biofilm, such as dental caries

Estratégias para implementação do Ecossistema para informação do Sistema Nacional de Juventude

Esta obra é um produto do Projeto de Pesquisa sobre o Estudo para Sistematização e Desenvolvimento do Sistema Nacional de Juventude (Sinajuve).As opiniões emitidas nesta publicação são de exclusiva e inteira responsabilidade dos autores, não exprimindo, necessariamente, o ponto de vista do Instituto Brasileiro de Informação em Ciência e Tecnologia ou do Ministério da Ciência, Tecnologia e Inovações.This book represents the final result of the research project signed between the Secretaria Nacional de Juventude (SNJ), then linked to the Secretaria Geral da Presidência da República, and the Instituto Brasileiro de Informação em Ciência e Tecnologia (Ibict). In this way, it brings together the main results obtained in the various studies carried out within the scope of proposing strategies for putting this system into execution, constituting one of the lines of support to the SNJ.O presente livro representa o resultado final do projeto de pesquisa firmado entre a Secretaria Nacional de Juventude (SNJ), então vinculada à Secretaria Geral da Presidência da República, e o Instituto Brasileiro de Informação em Ciência e Tecnologia (Ibict).Dessa forma, reúne os principais resultados obtidos nos diversos estudos efetuados no âmbito da proposição de estratégias para a colocação desse sistema em execução, constituindo uma das linhas de apoio à SNJ

Genomic epidemiology reveals how restriction measures shaped the SARS-CoV-2 epidemic in Brazil

Abstract Brazil has experienced some of the highest numbers of COVID-19 infections and deaths globally and made Latin America a pandemic epicenter from May 2021. Although SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, important gaps remain in our understanding of local virus transmission dynamics. Here, we describe the genomic epidemiology of SARS-CoV-2 using near-full genomes sampled from 27 Brazilian states and an adjacent country - Paraguay. We show that the early stage of the pandemic in Brazil was characterised by the co-circulation of multiple viral lineages, linked to multiple importations predominantly from Europe, and subsequently characterized by large local transmission clusters. As the epidemic progressed, the absence of effective restriction measures led to the local emergence and international spread of Variants of Concern (VOC) and under monitoring (VUM), including the Gamma (P.1) and Zeta (P.2) variants. In addition, we provide a preliminary genomic overview of the epidemic in Paraguay, showing evidence of importation from Brazil. These data reinforce the need for the implementation of widespread genomic surveillance in South America as a toolkit for pandemic monitoring and providing a means to follow the real-time spread of emerging SARS-CoV-2 variants with possible implications for public health and immunization strategies