Serotyping of Toxoplasma gondii Infection Using Peptide Membrane Arrays.

The intracellular parasite Toxoplasma gondii can cause chronic infections in most warm-blooded animals, including humans. In the USA, strains belonging to four different Toxoplasma clonal lineages (types 1, 2, 3, and 12) are commonly isolated, whereas strains not belonging to these lineages are predominant in other continents such as South America. Strain type plays a pivotal role in determining the severity of Toxoplasma infection. Therefore, it is epidemiologically relevant to develop a non-invasive and inexpensive method for determining the strain type in Toxoplasma infections and to correlate the genotype with disease outcome. Serological typing is based on the fact that many host antibodies are raised against immunodominant parasite proteins that are highly polymorphic between strains. However, current serological assays can only reliably distinguish type 2 from non-type 2 infections. To improve these assays, mouse, rabbit, and human infection serum were reacted against 950 peptides from 62 different polymorphic Toxoplasma proteins by using cellulose membrane peptide arrays. This allowed us to identify the most antigenic peptides and to pinpoint the most relevant polymorphisms that determine strain specificity. Our results confirm the utility of previously described peptides and identify novel peptides that improve and increase the specificity of the assay. In addition, a large number of novel proteins showed potential to be used for Toxoplasma diagnosis. Among these, peptides derived from several rhoptry, dense granule, and surface proteins represented promising candidates that may be used in future experiments to improve Toxoplasma serotyping. Moreover, a redesigned version of the published GRA7 typing peptide performed better and specifically distinguished type 3 from non-type 3 infections in sera from mice, rabbits, and humans

Toxoplasma gondii Superinfection and Virulence during Secondary Infection Correlate with the Exact [ROP5 over ROP18] Allelic Combination

The intracellular parasite Toxoplasma gondii infects a wide variety of vertebrate species globally. Infection in most hosts causes a lifelong chronic infection and generates immunological memory responses that protect the host against new infections. In regions where the organism is endemic, multiple exposures to T. gondii likely occur with great frequency, yet little is known about the interaction between a chronically infected host and the parasite strains from these areas. A widely used model to explore secondary infection entails challenge of chronically infected or vaccinated mice with the highly virulent type I RH strain. Here, we show that although vaccinated or chronically infected C57BL/6 mice are protected against the type I RH strain, they are not protected against challenge with most strains prevalent in South America or another type I strain, GT1. Genetic and genomic analyses implicated the parasite-secreted rhoptry effectors ROP5 and ROP18, which antagonize the host’s gamma interferon-induced immunity-regulated GTPases (IRGs), as primary requirements for virulence during secondary infection. ROP5 and ROP18 promoted parasite superinfection in the brains of challenged survivors. We hypothesize that superinfection may be an important mechanism to generate T. gondii strain diversity, simply because two parasite strains would be present in a single meal consumed by the feline definitive host. Superinfection may drive the genetic diversity of Toxoplasma strains in South America, where most isolates are IRG resistant, compared to North America, where most strains are IRG susceptible and are derived from a few clonal lineages. In summary, ROP5 and ROP18 promote Toxoplasma virulence during reinfection

Herbal extracts in an experimental mouthwash: pharmacognostics analysis and antibacterial activity

A utilização de extratos vegetais vem se tornando uma alternativa importante para a prevenção de doenças periodontais. Este trabalho objetivou desenvolver uma formulação de enxagüatório bucal, contendo, em associação, extratos hidroalcoólicos de Rosmarinus officinalis, Plantago major, Tabebuia impetiginosa, Achillea millefollium e Nasturtium officinale; avaliar sua composição farmacognóstica e sua atividade antibacteriana, como também da fórmula proposta. Foram realizados estudos de pré-formulação e análises farmacognósticas para as espécies vegetais. A atividade antibacteriana in vitro foi observada por meio dos métodos de difusão em disco de papel, por hole- plate e por template, frente a Staphylococcus aureus, Bacillus subtilis, Escherichia colik, Enterococcus faecalis e Pseudomonas aeruginosa. A concentração inibitória mínima (CIM) foi determinada por meio do método de macrodiluições sucessivas em caldo. Os resultados obtidos apresentaram-se de acordo com o histórico farmacognóstico das drogas estudadas. Todas as bactérias foram inibidas pelos extratos, observando-se que as espécies S. aureus e B. subtilis mostraram, aparentemente, maior sensibilidade. A CIM variou, em relação a sensibilidade de cada espécie bacteriana estudada, de 312,5 µL/mL a 1250 µL/mL para os extratos vegetais e de 625 µL/mL a 2500 µL/mL para o enxaguatório bucal. São necessários estudos complementares para a confirmação da eficácia deste produto e sua utilização na prevenção de doenças periodontais.In this study, herbs and hidroalcoholic extracts of Nasturtium officinale, Rosmarinus officinalis, Tabebuia impetiginosa, Plantago major and Achillea millefollium, were investigated for pharmacognostics analysis (flavonoids, alkaloids, tanins, saponins and antraquinones) and antibacterial activity (against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Enterococcus faecalis e Pseudomonas aeruginosa). In vitro antibacterial studies were carried by the disc diffusion method, hole plate and tamplate. The minimum inhibitory concentration (MIC) values were determinated by broth dilution method. The extracts were incorporated in mouthwash for periodontal diseases treatment. The pharmacognostics studies showed that herbs and extracts have substances groups described in literature. The antibacterial studies showed that extracts and mouthwash have some activity against all considered bacteria. S. aureus and B. subtilis showed, apparently, to be species more susceptible. Investigation of the MIC showed 312,5 µL/mL-1250 µL/mL for extracts and 625 µL/mL-2500 µL/mL for mouthwash. The studies served as initial quality control of the obtained cosmetic, enhancing anti-inflammatory (flavonoids) and/or antibacterial activities (tanins). However, new studies are necessary to confirm the cosmetic efficacy for treatment periodontal diseases

Chemical Composition, Antimicrobial and Antioxidant Activities of Eugenia Dysenterica DC Essential Oil

Eugenia dysenterica DC is a native species from the Cerrado biome and can be found in several states of Brazil. This study evaluated the chemical composition, antimicrobial and antioxidant activities from the essential oils of a population collected in São Paulo state. Essential oils were obtained by conventional means, and their compositions were analyzed by GC-MS. Screening assays for antimicrobial activity were carried out by the microdilution method and the antioxidant potential was assessed by the DPPH scavenging method. The GC-MS analysis indicated that 52.63% of the essential oil is composed by oxygenated sesquiterpenes and the major compound is (-)-elema-1,3,11(13)-trien-12-ol (24.86%). The antimicrobial assay indicated MIC 42.1 µg/mL for S. aureus and MIC > 10000 µg/mL for the other tested microorganisms, Gram negative bacteria and fungi. The oil showed an IC50 of 5.4±0.632 mg/mL for in the DPPH assay. The essential oil had a different chemical composition from previous studies. The essential oil did not present a potent antioxidant activity. However, it can be considered a promising antimicrobial agent against S. aureus

From Re-Emergence to Hyperendemicity: The Natural History of the Dengue Epidemic in Brazil

The spread of dengue virus is a major public health problem. Though the burden of dengue has historically been concentrated in Southeast Asian countries, Brazil has become the country that reports the largest number of cases in the world. While prior to 2007 the disease affected mostly adults, during the 2007 epidemic the number of dengue hemorrhagic fever cases more than doubled, and over 53% of cases were in children under 15 years of age. In this paper, we propose that the conditions for the shift were being set gradually since the re-introduction of dengue in 1986 and that they represent the transition from re-emergence to hyperendemicity. Using data from an age stratified seroprevalence study conducted in Recife, we estimated the force of infection (a measure of transmission intensity) between 1986–2006 and used these estimates to simulate the accumulation of immunity since the re-emergence. As the length of time that dengue has circulated increases, adults have a lower probability of remaining susceptible to primary or secondary infection and thus, cases become on average younger. If in fact the shift represents the transition from re-emergence to hyperendemicity, similar shifts are likely to be observed in the rest of Brazil, the American continent and other regions where transmission emerges

Influência da ingestão do suco de beterraba (Beta vulgaris L.) sobre o controle da pressão arterial / Influence of intake of beet juice (Beta vulgaris L.) on blood pressure control

Este trabalho objetivou analisar o que se conhece sobre a influência da ingestão de beterraba (Beta vulgaris) sobre a hipertensão arterial e identificar o direcionamento dos resultados obtidos em pesquisas experimentais, através de uma revisão sistemática de literatura. Foram realizadas buscas de artigos disponíveis nas bases de dados Pubmed, Google Acadêmico e Sciencedirect, nos idiomas de português e inglês, até 2018. Da busca inicial foram obtidos 2403 artigos, dentre os quais apenas 12 eram condizentes com os critérios de inclusão e contribuíam para a satisfação da pergunta norteadora deste trabalho. Estudos experimentais realizados por diferentes métodos e quantidades de suco ingerido diariamente até então não indicam influência significativa da ingestão de beterraba sobre o controle da pressão arterial dos pacientes, o que permite concluir que a ingestão de beterraba em períodos de até um mês não reduz a pressão arterial

Podcasts: compartilhando informações de saúde para idosos em tempos de COVID-19 / Podcasts: sharing health information for elderly people in COVID-19 times

Durante a pandemia da COVID-19, doença causada pelo novo coronavírus (Sars-CoV-2), o isolamento social se apresentou como uma das medidas mais eficazes para a prevenção da doença e para desacelerar a transmissão do vírus, posto que, inicialmente, era inexistente medidas farmacológicos e/ou tratamento específico. Neste cenário pandêmico, houve um aumento da utilização de tecnologias e mídias, em que nos deparamos com inúmeros recursos digitais, e que passaram a ser o principal meio de interação entre as pessoas. Os podcasts, comparados aos programas de rádio, são outro canal de compartilhamento de conteúdo em formato de arquivo de áudio, permitindo criar conteúdo com temas ilimitados e direcionados a públicos diversos, pois são gravados e permitem que o público determine o tema e o que deseja ouvir. Isto posto, este estudo teve como objetivo descrever um relato de experiência sobre a produção e a difusão de materiais informativos e educativos, por meio da reprodução de podcasts transmitidos via rádio para propagar orientações de nutrição e cuidados com a saúde em tempo da COVID-19, como meio de interação com a população idosa. Para a realização das ações educativas foram produzidos sete podcasts abordando diversos temas como: higienização de embalagens de alimentos, aproveitamento integral dos alimentos, uso de ervas e temperos e sobre o consumo de chás. A reprodução dos podcasts na rádio local mostrou-se um meio de levar informações de saúde aos ouvintes, de forma eficiente e muito mais abrangente, beneficiando não só aos idosos, mas a toda população.