Cloning, expression and characterization of SeM protein of Streptococcus equi subsp. equi and evaluation of its use as antigen in an indirect ELISA

A adenite equina é uma enfermidade economicamente importante de equinos, causada por Streptococcus equi subsp. equi. Seu diagnóstico pode ser confirmado de forma direta, por meio de isolamento bacteriano e de PCR, ou de forma indireta, por meio de ELISA, método baseado na detecção de anticorpos séricos. O objetivo deste estudo foi clonar, expressar e caracterizar a proteína SeM de Streptococcus equi subsp. equi, avaliar sua utilização como antígeno em um ELISA indireto e determinar a capacidade do teste de distinguir soros de animais negativos, vacinados e positivos. Para tal, foi inicialmente realizada a clonagem do gene que codifica para a proteína SeM e sua expressão em Escherichia coli. Posteriormente, a proteína produzida foi caracterizada e utilizada como antígeno em um teste de ELISA indireto. Para avaliação do teste, foram utilizadas amostras de soro de 40 potros negativos, de 46 equinos vacinados com uma vacina comercial contra adenite equina e de 46 equinos com diagnóstico da doença. O teste demonstrou alta sensibilidade e especificidade, permitindo discriminar entre soros negativos e positivos, positivos e de animais vacinados, e negativos e de animais vacinados. Assim, conclui-se que a proteína rSeM produzida pode ser usada como antígeno para o diagnóstico da enfermidade e que o ELISA descrito pode ser útil para avaliar o estado imunológico do rebanho.

Topografia superficial e aderência de Streptococcus mutans no titânio após imersão e escovação com dentifrícios fluoretado e não-fluoretado simulando 10 anos de uso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da eficácia da terapia fotodinâmica, mediada pelos fotossensibilizadores Photodithazine® e Curcumina, sobre biofilmes multi-espécies formados por Streptococcus mutans, Candida albicans e Candida glabrata

Pós-graduação em Reabilitação Oral - FOAR

Avaliação dos efeitos de Streptococcus mutans sobre formação de biofilme e morfogênese de Candida albicans in vitro e estudo experimental em Galleria mellonella

Pós-graduação em Biopatologia Bucal - ICT

Efeito da terapia fotodinâmica antimicrobiana mediada por curcumina sobre Streptococcus Mutans

Pós-graduação em Ciências Odontológicas - FOAR

Prevalência de Streptococcus suis sorotipo 2: discussão da literatura brasileira

Streptococcus suis is considered worldwide as one of the pathogens of biggest health and economic impact in the swine industry. Among the serotypes described as zoonotic, serotype 2 is the most frequently isolated from diseased animals and humans in most countries. The study of the epidemiology of S. suis infections in Brazil is important and may help in the development of effective control measures. The aim of this study was to conduct a critical review of Brazilian literature, with support of the world literature, addressing the diagnosis of the agent and its prevalence in clinically ill animals and healthy carriers, especially regarding to the prevalence of the serotype 2 in the country.

Desempenho e hematologia de tilápias-do-nilo alimentadas com Saccharomyces cerevisiae e vacinadas contra Streptococcus agalactiae

The objective of this work was to evaluate the inter-relationship between dietary supplementation with Saccharomyces cerevisiae cell wall and vaccination against Streptococcus agalactiae, and its effect on the productive performance and hematological variables of Nile tilapia (Oreochromis niloticus). Eighty-four Nile tilapia were distributed in 12 fiber boxes (n=7), in a 2x2x3 factorial arrangement, corresponding to two levels of supplementation with yeast cell wall, two types of inoculation, and three evaluation times. Fish were fed during 77 days. Vaccination of fish was done 60 days after feeding started. Fifteen days after vaccination, all fish were subjected to challenge with live strain of S. agalactiae, and 6, 24, and 48 hours after the challenge, blood was collected from the caudal vein for evaluations. Fish fed with supplemented diets show greater weight gain and specific growth rate, and the interaction between the diet and vaccination effects results in higher hematocrit, hemoglobin, and leukocyte rates.

Resposta imune de tilápias do Nilo (Oreochromis niloticus) vacinadas contra Streptococcus agalactiae

Pós-graduação em Medicina Veterinária - FCAV

Avaliação das correlações existentes entre experiência de cárie, acúmulo de placa bacteriana e nível de Iga anti-streptococcus mutans na saliva de crianças com dentição mista

Pós-graduação em Odontologia Restauradora - ICT

Antimicrobial susceptibility of streptococcus suis isolated from clinically healthy swine in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Streptococcus agalactiae in Brazil: serotype distribution, virulence determinants and antimicrobial susceptibility

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Streptococcus Mutans Photoinactivation by Combination of Short Exposure of a Broad-Spectrum Visible Light and Low Concentrations of Photosensitizers

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fibrinogen-Induced Streptococcus mutans Biofilm Formation and Adherence to Endothelial Cells

Streptococcus mutans, the predominant bacterial species associated with dental caries, can enter the bloodstream and cause infective endocarditis. The aim of this study was to investigate S. mutans biofilm formation and adherence to endothelial cells induced by human fibrinogen. The putative mechanism by which biofilm formation is induced as well as the impact of fibrinogen on S. mutans resistance to penicillin was also evaluated. Bovine plasma dose dependently induced biofilm formation by S. mutans. Of the various plasma proteins tested, only fibrinogen promoted the formation of biofilm in a dose-dependent manner. Scanning electron microscopy observations revealed the presence of complex aggregates of bacterial cells firmly attached to the polystyrene support. S. mutans in biofilms induced by the presence of fibrinogen was markedly resistant to the bactericidal effect of penicillin. Fibrinogen also significantly increased the adherence of S. mutans to endothelial cells. Neither S. mutans cells nor culture supernatants converted fibrinogen into fibrin. However, fibrinogen is specifically bound to the cell surface of S. mutans and may act as a bridging molecule to mediate biofilm formation. In conclusion, our study identified a new mechanism promoting S. mutans biofilm formation and adherence to endothelial cells which may contribute to infective endocarditis.

Subinhibitory Concentrations of Triclosan Promote Streptococcus mutans Biofilm Formation and Adherence to Oral Epithelial Cells

Triclosan is a general membrane-active agent with a broad-spectrum antimicrobial activity that is commonly used in oral care products. In this study, we investigated the effect of sub-minimum inhibitory concentrations (MICs) of triclosan on the capacity of the cariogenic bacterium Streptococcus mutans to form biofilm and adhere to oral epithelial cells. As quantified by crystal violet staining, biofilm formation by two reference strains of S. mutans was dose-dependently promoted, in the range of 2.2- to 6.2-fold, by 1/2 and 1/4 MIC of triclosan. Observations by scanning electron microscopy revealed the presence of a dense biofilm attached to the polystyrene surface. Growth of S. mutans in the presence of triclosan at subMICs also increased its capacity to adhere to a monolayer of gingival epithelial cells. The expression of several genes involved in adherence and biofilm formation in S. mutans was investigated by quantitative RT-PCR. It was found that subMICs of triclosan significantly increased the expression of comD, gtfC, and luxS, and to a lesser extent of gtfB and atlA genes. These findings stress the importance of maintaining effective bactericidal concentrations of therapeutic triclosan since subMICs may promote colonization of the oral cavity by S. mutans.

In vitro evaluation of adherence of Candida albicans, Candida glabrata, and Streptococcus mutans to an acrylic resin modified by experimental coatings

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)