Tesis: "Streptococcus sanguinis"

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Mahoney, Brian. "Examination of platelet adhesion by Streptococcus sanguinis". VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/1978.

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Streptococcus sanguinis is a leading cause of infective endocarditis. Bacterial adhesion to platelets is likely important in the pathogenesis of infective endocarditis. Bacterial cell wall-anchored (Cwa) proteins may mediate this adhesion. To begin to test this hypothesis, S. sanguinis adhesion to platelets was examined in vitro. The requirement of 12 Cwa proteins for S. sanguinis-platelet adhesion was individually assessed, measuring adhesion of purified platelets to polystyrene wells coated with S. sanguinis strain SK36 or 12 isogenic Cwa protein mutants. Significantly fewer platelets adhered to wells coated with one mutant strain, VT1614. However, results of a whole-cell enzyme-linked immunosorbent assay (ELISA) showed that 8 mutants, including VT1614, adhered in significantly lower numbers to wells than did SK36. After accounting for unequal bacterial numbers, we determined there was no significant difference in platelet adhesion among the strains. This suggests that none of the Cwa proteins examined were required for S. sanguinis-platelet adhesion.

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2

Atia, Sawsan. "SYSTEMATIC ANALYSIS OF ABC TRANSPORTERS IN STREPTOCOCCUS SANGUINIS". VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3054.

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The bacterium Streptococcus sanguinis is a primary member of the human oral microflora and also has been recognized as a key player in the bacterial colonization of the mouth. It is considered the most common viridians streptococcal species implicated in infective endocarditis. In all kingdoms of life, ATP binding cassette (ABC) transporters are essential to many cellular functions. Sequencing of the SK36 genome provided the opportunity to study ABC transporter mutants and their relationship with acidity of the oral environment. Despite numerous studies that have focused on carbohydrate uptake systems in closely related streptococcal species such as S. mutans, S. pneumonia and S. pyogenes, the mechanism of the response of these ABC transporters to acidic conditions in S. sanguinis is still unknown. The capability of S. sanguinis to adapt in these harsh environments suggests this bacterium is capable of responding to various environmental stimuli. The purpose of this study was to examine ABC mutants to identify functions that contribute to acid tolerance in S. sanguinis. This study demonstrates that two acid-sensitive mutant genes, SSA_1507 and SSA_1508, identify genes involved in acid tolerance. The two mutants grew on different sugars and none of them showed a defect in sugar utilization at acid pH. We couldn’t recognize any significant differences in sugar uptake for the two acid sensitive mutants or in mutants of their neighboring genes. Thus, the observed acid sensitivity is not due to a failure to take up any of the common sugars tested. The cytoplasmic pH of S. sanguinis was studied with the fluorescent pH indicator (BCECF) and SK36 was observed to have a wider pH range than either of the two acid-sensitive mutants SSA_1507 or SSA_1508. In these two mutants, intracellular pH was not as well maintained. At all pH values tested, the mutants displayed a lower intracellular pH than the wild type. These observations indicate that the cell membrane of these two mutants is unable to protect the interior components from adverse effects of higher pH values and lower pH values, and prove that these two mutant genes SSA_1507 and SSA_1508 are unable to grow in lower pH values. These results support a role for these ABC transporters in proton pump or export and indicate that the mutants are less able to pump out protons.

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3

Callahan, Jill. "Functional Characterization of the Streptococcus sanguinis com Regulon". VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/252.

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Streptococcus sanguinis is an important component of the dental plaque biofilm and is believed to play a beneficial role in the oral cavity. S. sanguinis is also a leading cause of infective endocarditis (IE), a potentially lethal infection of the cardiac valves. S. sanguinis possesses genetic competence, the ability to acquire exogenous DNA into its genome. In the well characterized system of S. pneumoniae, genetic competence requires a quorum sensing system encoded by the early comCDE genes, as well as late genes controlled by the alternate sigma factor, ComX. Previous studies in other streptococcal species have suggested functions for the com regulon apart from DNA uptake. Here we characterized functions of the S. sanguinis com regulon genes in genetic competence, IE virulence, and biofilm formation. Our findings indicated that the early regulatory genes and those under the control of ComX in S. sanguinis play similar roles in genetic competence as their orthologs in other competent streptococci; however the sequence and mechanism of processing of the quorum sensing signal, competence-stimulating peptide, CSP, were determined to be unique. Using a rabbit endocarditis model, we determined that the comCDE and comX genes were not required for virulence, bacteremia, or pathology under a variety of infection conditions. In contrast, examination of biofilms by microscopy and crystal violet staining indicated that S. sanguinis CSP enhanced biofilm formation in a comDE-dependent manner. Deletion of the early com gene SSA_0195 eliminated this effect, while expression of the gene from an inducible promoter increased biofilm formation in the absence of CSP. Deletion of the comX gene resulted in biofilms with increased staining, cell death, and profoundly altered structure. Treatment with DNase I reduced biofilm formation in a com-independent manner. Taken together, these results suggest that expression of SSA_0195 is both necessary and sufficient for CSP-dependent biofilm enhancement, and that the late gene activator, ComX, is required to maintain normal biofilm architecture. Our findings suggest the com regulon of S. sanguinis may be an important determinant of competitiveness in the mouth, where native CSP production may occur at levels sufficient to influence biofilm formation.

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4

Turner, Lauren. "Identification of Virulence Determinants for Streptococcus sanguinis Infective Endocarditis". VCU Scholars Compass, 2008. http://scholarscompass.vcu.edu/etd/1560.

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Streptococcus sanguinis is the second most common causative agent of bacterial infective endocarditis (IE). Risk of S. sanguinis IE is dependent on pre-disposing damage to the heart valve endothelium, which results in deposition of clotting factors for formation of a sterile thrombus (referred to as vegetation). Despite medical advances, high mortality and morbidity rates persist. Molecular characterization of S. sanguinis virulence determinants may enable development of prevention methods. In a previous screen for S. sanguinis virulence determinants by signature-tagged mutagenesis (STM) an attenuated mutant was identified with a transposon insertion in the nrdD gene, encoding an anaerobic ribonucleotide reductase. Evaluation of this mutant, as well as an nrdD in-frame deletion mutant, JFP27, by a soft-agar growth assay confirmed the anaerobic growth sensitivity of these strains. These studies suggest that an oxygen gradient occurs at the site of infection which selects for expression of anaerobic-specific genes at the nexus of the vegetation. The random STM screen failed to identify any favorable streptococcal surface-exposed prophylactic candidates. It was also apparent that additional genetic tools were required to facilitate the in vivo analyses of mutant strains. As it was desirable to insert antibiotic resistance markers into the chromosome, we identified a chromosomal site for ectopic expression of foreign genes. In vitro and in vivo analyses verified that insertion into this site did not affect important cellular phenotypes. The genetic tools developed facilitated further in vivo screening of S. sanguinis cell wall-associated (Cwa) protein mutants. A directed application of STM was employed for a comprehensive analysis of this surface protein class in the rabbit model of IE. Putative sortases, upon which Cwa proteins are dependent for cell surface localization, were also evaluated. No single S. sanguinis Cwa protein was determined essential for IE by STM screening; however competitiveness for colonization of the infection site was reduced for the mutant lacking expression of sortase A. The studies described here present a progressive picture of S. sanguinis IE, beginning with surface protein-dependent colonization of the vegetation in early IE, that later shifts to a bacterial persistence in situ dependent on condition-specific housekeeping genes, including nrdD.

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5

Medina, Flores Dyanne Adenea, Urizar Gabriela Ulloa, Colarossi Rosella Camere, García Stefany Caballero, Tovalino Frank Mayta y Valle Mendoza Juana Del. "Antibacterial activity of Bixa orellana L. (achiote) against Streptococcus mutans and Streptococcus sanguinis". Universidad Peruana de Ciencias Aplicadas (UPC), 2016. http://hdl.handle.net/10757/604437.

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Objective To evaluate the cytotoxic and antibacterial effect of Bixa orellana L. (B. orellana) (achiote) methanol extract against Streptococcus mutans (ATCC 25175) (S. mutans) and Streptococcus sanguinis (ATCC 10556) (S. sanguinis). Methods Two methanol extracts of B. orellana were prepared in vitro, from the seeds and leaves. The antibacterial activity of extracts against S. mutans and S. sanguinis was evaluated using the cup-plate agar diffusion method. The minimum inhibitory concentration (MIC) was determined using the microdilution method and the cytotoxic activity was determinated by using the cell line MDCK. Results A stronger antibacterial effect was observed with the leaves methanolic extract with an inhibition zone of (19.97 ± 1.31) mm against S. mutans and (19.97 ± 1.26) mm against S. sanguinis. The methanolic extract of the seeds had an activity of (15.11 ± 1.03) mm and (16.15 ± 2.15) mm against S. mutans and S. sanguinis, respectively. The MIC of the leaf and the seed extracts against S. sanguinis was 62.5 and 125 μg/mL, respectively, and the MIC of the leaf extract against S. mutans was 62.5 μg/mL, and for the seed extract it was 31.25 μg/mL. The 50% cytotoxic concentration was 366.45 and 325.05 μg/mL for the leaves and seeds extracts, respectively. Conclusions The experimental findings demonstrated the antibacterial effect of the methanolic extract of B. orellana (achiote) on S. mutans and S. sanguinis. The extract of this plant is cytotoxic at high concentrations.
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6

Camere, Colarossi Rosella, Urizar Gabriela Ulloa, Flores Dyanne Medina, García Stefany Caballero, Tovalino Frank Mayta y Valle Mendoza Juana Mercedes Del. "Antibacterial activity of Myrciaria dubia (Camu camu) against Streptococcus mutans and Streptococcus sanguinis". Elsevier B.V, 2016. http://hdl.handle.net/10757/620656.

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Objective: To evaluate the antibacterial and cytotoxic effect of Myrciaria dubia (Camu camu) (M. dubia) methanol extract, against Streptococcus mutans (ATCC 25175) (S. mutans) and Streptococcus sanguinis (ATCC 10556) (S. sanguinis). Methods: Two methanol extracts of M. dubia were prepared in vitro, from the seeds and pulp. Ten independent tests were prepared for each type of extract, using 0.12% chlorhexidine solution as positive control. Agar diffusion test was used by preparing wells with the experimental solutions cultivated in anaerobic conditions for 48 h at 37 °C. Meanwhile, the minimum inhibitory concentration and the cytotoxic effect over MDCK cell line was found. Results: A higher antibacterial effect was observed with the methanol seed extract with an inhibitory halo of (21.36 ± 6.35) mm and (19.21 ± 5.18) mm against S. mutans and S. sanguinis, respectively. The methanol extract of the pulp had an effect of (16.20 ± 2.08) mm and (19.34 ± 2.90) mm, respectively. The minimum inhibitory concentration of the pulp extract was 62.5 µg/mL for both strains, whereas for the seed antibacterial activity was observed even at low concentrations. The CC50 of the seeds extract was at a higher concentration than 800 µg/mL and 524.37 µg/mL for the pulp extract.
This study was supported by Universidad Peruana de Ciencias Aplicadas (UPC) Lima-Peru with Grant No. MANUSCRIPT ACCEPTED ACCEPTED MANUSCRIPT UPC-501-2015

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7

Turner, Lauren Senty. "Identification of virulence determinants for streptococcus sanguinis infective endocarditis /". Online version not available until 8/4/2013, 2008. http://hdl.handle.net/10156/2243.

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8

Patel, Jenishkumar. "ENVIRONMENTAL RESPONSES OF TWO-COMPONENT SYSTEMS IN STREPTOCOCCUS SANGUINIS". VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2270.

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The gram-positive bacterium Streptococcus sanguinis is a member of human indigenous oral microbialflora and has long been recognized as a key player in the bacterial colonization of the mouth. S. sanguinis is also the most common viridians streptococcal species implicated in infective endocarditis. Although many studies have focused on two-component systems in closely related Streptococcus species such as S. mutans, S. pneumoniae and S. gordonii; the mechanism of the response regulator in S. sanguinis is still unknown. The ability of S. sanguinis to adapt and thrive in hostile environments suggests this bacterium is capable of sensing and responding to various environmental stimuli. The present study clearly demonstrates that a number of RR genes, SSA_0204, SSA_0217, SSA_1810, SSA_1794, and SSA_1842, in S. sanguinis are essential to the recognition and response to various environmental stresses. Results from this study also identified genes SSA_0260, SSA_0261, and SSA-0262, involved in acidic tolerance and suppressed by SSA_0204 response regulator.

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9

Rodriguez, Alejandro. "Physiological and Molecular Characterization of Genetic Competence in Streptococcus sanguinis". VCU Scholars Compass, 2008. http://scholarscompass.vcu.edu/etd/1570.

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The ability of bacteria to assimilate free DNA from the environment is known as competence. Though many studies have focused on competence regulation in Streptococcus pneumoniae and Streptococcus gordonii, Streptococcus sanguinis has yet to be examined. Physiological characterization of competence in S. sanguinis strain SK36 and its comC mutant, JFP41, led to the genome-wide transcriptional analysis of cells induced to competence via addition of competence-stimulating peptide (CSP). A total of 128 genes were induced at least 2-fold, 74 of which were classified as either “early” or “late” based on their induction patterns. Expression patterns were verified using qRT-PCR. This study identified genes not up-regulated in S. pneumoniae or S. gordonii and lays the foundation for bioinformatic studies to identify conserved binding sites upstream from CSP-regulated genes. These results also shed light on the possible existence and identity of expected CSP exporters in S. sanguinis, which have so far eluded discovery.

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10

Aynapudi, Jessica. "Involvement of Signal Peptidase I in Streptococcus sanguinis Biofilm Formation". VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4451.

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Biofilm accounts for 65%-80% of microbial infections in humans. Considerable evidence links biofilm formation to oral disease and consequently systemic infections. Eradication of biofilm-associated infections is important. Streptococcus sanguinis, a Gram-positive bacterium, is one of the most abundant species in oral biofilm. It contributes to biofilm development in oral cavities and is one of the recognized causes of infective endocarditis. To study and identify biofilm genes in S. sanguinis, biofilm formation of 51 mutants was compared with the wild type SK36 strain using crystal violet (CV) staining in a microtiter plate. Confocal laser scanning microscopy (CLSM) and image analysis was done to compare biofilm formation by the mutant to the wild type SK36 strain. A biofilm mutant XG2_0351, encoding a type I signal peptidase (SPase I), was further investigated. SPase I cleaves proteins that are transported through secretory machinery and is necessary for the release of translocated preproteins from a cytoplasmic site of synthesis to extracytoplasmic/membrane destinations. S. sanguinis, like many Gram-positive bacteria, has multiple SPases I. The objective of this project is to investigate the distinctive role that SPase I plays in biofilm formation in S. sanguinis. Using a plate reader, the growth curves of the wild type strain SK36 and XG2_0351 were compared. The scanning electron microscope (SEM) was utilized to compare the cell surface morphologies. Coomassie staining was done to narrow the list of potential substrates of XG2_0351. CV staining and CLSM images indicated phenotypic differences between the SPase I mutant and SK36. The growth curves of XG2_0351 and SK36 showed no significant difference although SEM illustrated a difference in the cell surface morphologies. Coomassie staining illustrated a number of substrates that were present in SK36 but not XG2_0351. In addition bioinformatics was used to understand the gene function. In conclusion, XG2_0351 reduces biofilm formation in S. sanguinis but further research is necessary to elucidate the specific proteins that are involved. Clarifying the vii role that SPase I plays in reduced biofilm formation in S. sanguinis will give a better understanding of the biofilm formation mechanism.

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Veras, Idia Nara de Sousa. "Análise do perfil morfológico de candida tropicalis durante a formação do biofilme sob influência de metabólitos extracelulares de bactérias do gênero Streptococcus". reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/18054.

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VERAS, I. N. Análise do perfil morfológico de candida tropicalis durante a formação do biofilme sob influência de metabólitos extracelulares de bactérias do gênero Streptococcus. 2014. 77 f. Dissertação ( Mestrado em Biotecnologia) - Campus de Sobral, Universidade Federal do Ceará, Sobral, 2014.
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Bacteria and fungi are found together in a multitude of environments, and particularly in the form of biofilm adherent species which interact through various signaling mechanisms. In the oral cavity, Candida species coexist with numerous bacterial species, and evidence suggests that bacteria can modulate biofilm formation as well as induce the formation of hyphae. Thus, to characterize such interactions are essential to the understanding of pathogenesis of diseases and possibly the discovery of new therapeutic strategies. In this sense, the main objective of this study was to evaluate, in vitro, the mechanisms involved in the interaction between bacteria Streptococcus oralis, Streptococcus sanguinis, and Streptococcus parasanguinis yeast Candida tropicalis. In the study the effect of extracellular metabolites present in the supernatant of C. tropicalis (SCT) on the pre-formed biofilm (6H) S. oralis, S. sanguinis and S. parasanguinis was analyzed. The effect of extracellular metabolites of S. oralis (SSO), S. sanguinis (SSS) and S. parasanguinis (SSP) on planktonic growth and biofilm
Bactérias e fungos são encontrados juntos em uma infinidade de ambientes e, particularmente, na forma de biofilme, onde as espécies aderentes interagem através de diversos mecanismos de sinalização. Na cavidade oral, espécies de Candida coexistem com inúmeras espécies bacterianas, e evidências sugerem que bactérias podem modular a formação de biofilme, bem como induzir a formação de hifas e pseudo-hifas. Assim, caracterizar tais interações é essencial para o entendimento da patogênese das doenças e, possivelmente, a descoberta de novas estratégias terapêuticas. Nesse sentido, o objetivo principal deste trabalho foi avaliar, in vitro, os mecanismos envolvidos na interação entre as bactérias Streptococcus oralis, Streptococcus sanguinis, Streptococcus parasanguinis e a levedura Candida tropicalis. No estudo foi analisado o efeito dos metabólitos extracelulares presentes no sobrenadante de C. tropicalis (SCT) sobre o biofilme pré-formado (6h) de S. oralis, S. sanguinis e S. parasanguinis. Também foi avaliado o efeito dos metabólitos extracelulares de S. oralis (SSO), S. sanguinis (SSS) e S. parasanguinis (SSP) sobre o crescimento planctônico, formação de biofilme e capacidade de filamentação de C. tropicalis, utilizando apenas o sobrenadante da cultura de cada um dos estreptococos em diferentes concentrações (100, 50 e 25%). Além disso, foi analisado o efeito dos metabólitos extracelulares dos estreptococos sobre o biofilme pré-formado (6h) de C. tropicalis. Para verificar o efeito dos metabólitos extracelulares foram utilizados dois métodos: o método turbidimétrico que se baseia na leitura da densidade óptica (OD) das suspensões celulares e a coloração cristal violeta (CV) que permite a quantificação indireta da formação de biofilme através da coloração com cristal violeta. Em seguida, foram examinadas as características dos biofilmes, formados por 24 horas, através da análise por microscopia óptica comum. Os resultados referentes ao biofilme foram submetidos ao ANOVA com pós-teste Bonferroni, com diferença estatística de p<0,01. Nossos resultados sugerem que substâncias solúveis produzidas por S. oralis, S. sanguinis e S. parasanguinis induzem a formação de hifas de C. tropicalis sem interferir no crescimento planctônico. Além de diminuir drasticamente o desenvolvimento do biofilme dessa levedura quando em contato com SSS e SSP. Tal fato reforça a ideia de que existe grande heterogeneidade dentro de biofilmes polimicrobianos, especialmente entre leveduras e bactérias. E que o resultado dessa interação depende das condições as quais estes micro-organismos serão submetidos.

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Evans, Karra. "SYSTEMATIC STUDY OF GENE FUNCTIONS FOR MORPHOLOGICAL CHAIN FORMATION IN STREPTOCOCCUS SANGUINIS". VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/2514.

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Streptococcus sanguinis is a gram-positive facultative anaerobe that is indigenous to the oral cavity and a primary colonizer of the oral cavity. It serves as a tether for the attachment of several oral bacteria that colonize the tooth surface, form dental plaque, and cause periodontal disease. Previous experiments with streptococcal strains have suggested that cellular chain morphology of streptococci may influence the competitiveness, susceptibility to phagocytosis, acidurance, and aggregation of the bacterium. The purpose of this study was to systematically determine gene functions that contribute to cellular chain length morphology in the SK36 strain of S. sanguinis. Gene functions for 2048 mutants were elucidated along with Clusters of Orthologous Groups (COG) functions that may be related to or regulate chain formation and morphology. The COG functions with high ratios of genes involved with chain length morphology per number of total non-essential mutant COG functions were in the following order: Cell division and Chromosome Separation, Defense Mechanisms, and Signal Transduction Mechanisms, and Cell Motility and Secretion. Examination of gene annotations of the 326 mutants involved with chain morphology suggests that cellular chain length is dependent on cell wall division and septation, peptidoglycan synthesis, and cell wall mobility. Some of the genes that contribute to chain length properties may be co-regulated which may suggest that chain length phenotypes are a transcriptionally regulated property that further studies may confirm.

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13

Dvergsten, Erik C. "A Weighted Gene Co-expression Network Analysis for Streptococcus sanguinis Microarray Experiments". VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4430.

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Streptococcus sanguinis is a gram-positive, non-motile bacterium native to human mouths. It is the primary cause of endocarditis and is also responsible for tooth decay. Two-component systems (TCSs) are commonly found in bacteria. In response to environmental signals, TCSs may regulate the expression of virulence factor genes. Gene co-expression networks are exploratory tools used to analyze system-level gene functionality. A gene co-expression network consists of gene expression profiles represented as nodes and gene connections, which occur if two genes are significantly co-expressed. An adjacency function transforms the similarity matrix containing co-expression similarities into the adjacency matrix containing connection strengths. Gene modules were determined from the connection strengths, and various network connectivity measures were calculated. S. sanguinis gene expression profile data was loaded for 2272 genes and 14 samples with 3 replicates each. The soft thresholding power β=6 was chosen to maximize R2 while maintaining a high mean number of connections. Nine modules were found. Possible meta-modules were found to be: Module 1: Blue & Green, Module 2: Pink, Module 3: Yellow, Brown & Red, Module 4: Black, Module 5: Magenta & Turquoise. The absolute value of module membership was found to be highly positively correlated with intramodular connectivity. Each of the nine modules were examined. Two methods (intramodular connectivity and TOM-based connectivity followed by network mapping) for identifying candidate hub genes were performed. Most modules provided similar results between the two methods. Similar rankings between the two methods can be considered equivalent and both can be used to detect candidate hub genes. Gene ontology information was unavailable to help select a module of interest. This network analysis would help researchers create new research hypotheses and design experiments for validation of candidate hub genes in biologically important modules.

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Domingues, Nádia [UNESP]. "Biofilmes multiespécies de Candida Albicans associados com streptococcus mitis e streptococcus sanguinis: estudo in vitro e in vivo". Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/127663.

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Streptococcus sanguinis e Streptococcus mitis são colonizadores pioneiros do biofilme bucal e podem causar endocardite bacteriana. Candida albicans está presente na cavidade bucal de forma comensal, possui capacidade de formar biofilme e causar candidose bucal. O objetivo desse trabalho foi avaliar as interações entre C. albicans com S. sanguinis e S. mitis em biofilmes e suas influências in vivo em modelo experimental de invertebrado Galleria mellonella. Para o estudo da interação de C. albicans (ATCC 18804) com S. sanguinis (ATCC 7073) e S. mitis (ATCC 4945) foram formados biofilmes monoespécie e multiespécies de C. albicans com os micro-organismos (na concentração de 107 células/mL) em fundo de placa de 96 poços por 48 h, incubados em estufa a 37 °C com 5% CO2. Após crescimento, os biofilmes foram desprendidos e obtidas diluições decimais as quais foram semeadas em meios seletivos. Após incubação por 48 h/37 °C foi obtida a contagem de unidades formadoras de colônias por mililitro (UFC/mL). Em paralelo, foram realizados ensaios colorimétricos com o sal XTT, a fim de mensurar a atividade metabólica de C. albicans nos biofilmes isolados e associados, seguindo de leitura a 492 nm, e o resultado expresso em absorbância (Abs). No estudo in vivo, primeiro foram determinadas as concentrações subletais dos micro-organismos, e inoculadas em G. mellonella, e observado o efeito de C. albicans, S. mitis e S. sanguinis nas lagartas, avaliando se curva de sobrevivência. Avaliação morfológica dos biofilmes foi realizada por microscopia eletrônica de varredura (MEV). Os dados de contagem de UFC/mL e da atividade metabólica foram submetidos à análise de normalidade, e como foi observada distribuição normal, os resultados foram analisados estatisticamente pelos testes t de Student (para duas variáveis) e Tukey (para três ou mais variáveis), considerando-se diferença estatística quando p <0,05. Os dados obtidos na curva de..
Streptococcus sanguinis and Streptococcus mitis are pioneering colonizers of oral biofilm and can cause bacterial endocarditis. Candida albicans is present in the oral cavity in a commensal manner and also has the ability to form biofilm and cause oral candidiasis. The aim of this study was to evaluate the interactions between C. albicans with S. sanguinis and S. mitis biofilms and their influences in vivo on an experimental invertebrate model of Galleria mellonella. To study the interaction of C. albicans (ATCC 18804) with S. sanguinis (ATCC 7073) and S. mitis (ATCC 4945) monospecies and multispecies biofilms were formed of C. albicans and with micro-organisms (a concentration of 107 cells/ml) in the bottom of a 96-well plate for 48 h, incubated at 37 °C with 5% CO₂. After growth, biofilms were detached, and decimal dilutions were plated on selective media. After incubation for 48 h/37 °C the count of colony forming units per milliliter (CFU/mL) was obtained. Alongside, XTT salt colorimetric assays were carried in order to measure the metabolic activity of isolated and associated C. albicans biofilms, following reading at 492 nm, and the result expressed in absorbance (Abs). In the in vivo study, first the sublethal concentrations of microorganisms were determined, and inoculated into G. mellonella, and the effect of C. albicans, S. mitis and S. sanguinis in caterpillars was observed, evaluating the survival curve. Morphological evaluation of the biofilms was performed by scanning electron microscopy (SEM). The count of CFU/mL and metabolic activity were submitted to normality analisis, and as a normal distribution was observed, the results were statistically analyzed by Student's t test (for two variables) and Tukey (for three or more variables) considering statistical difference at p < 0.05. The G. mellonella survival curves data were analyzed by log-rank method. Streptococci influenced the reduction of biofilms of C. albicans and ....

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Domingues, Nádia. "Biofilmes multiespécies de Candida Albicans associados com streptococcus mitis e streptococcus sanguinis: estudo in vitro e in vivo /". São José dos Campos, 2014. http://hdl.handle.net/11449/127663.

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Orientador: Antonio Olavo Cardoso Jorge
Co-orientador: Cristiane Aparecida Pereira Correia
Banca: Silvia Maria Rodrigues Querido
Banca: Luciane Dias de Oliveira
Resumo: Streptococcus sanguinis e Streptococcus mitis são colonizadores pioneiros do biofilme bucal e podem causar endocardite bacteriana. Candida albicans está presente na cavidade bucal de forma comensal, possui capacidade de formar biofilme e causar candidose bucal. O objetivo desse trabalho foi avaliar as interações entre C. albicans com S. sanguinis e S. mitis em biofilmes e suas influências in vivo em modelo experimental de invertebrado Galleria mellonella. Para o estudo da interação de C. albicans (ATCC 18804) com S. sanguinis (ATCC 7073) e S. mitis (ATCC 4945) foram formados biofilmes monoespécie e multiespécies de C. albicans com os micro-organismos (na concentração de 107 células/mL) em fundo de placa de 96 poços por 48 h, incubados em estufa a 37 °C com 5% CO2. Após crescimento, os biofilmes foram desprendidos e obtidas diluições decimais as quais foram semeadas em meios seletivos. Após incubação por 48 h/37 °C foi obtida a contagem de unidades formadoras de colônias por mililitro (UFC/mL). Em paralelo, foram realizados ensaios colorimétricos com o sal XTT, a fim de mensurar a atividade metabólica de C. albicans nos biofilmes isolados e associados, seguindo de leitura a 492 nm, e o resultado expresso em absorbância (Abs). No estudo in vivo, primeiro foram determinadas as concentrações subletais dos micro-organismos, e inoculadas em G. mellonella, e observado o efeito de C. albicans, S. mitis e S. sanguinis nas lagartas, avaliando se curva de sobrevivência. Avaliação morfológica dos biofilmes foi realizada por microscopia eletrônica de varredura (MEV). Os dados de contagem de UFC/mL e da atividade metabólica foram submetidos à análise de normalidade, e como foi observada distribuição normal, os resultados foram analisados estatisticamente pelos testes t de Student (para duas variáveis) e Tukey (para três ou mais variáveis), considerando-se diferença estatística quando p <0,05. Os dados obtidos na curva de..
Abstract: Streptococcus sanguinis and Streptococcus mitis are pioneering colonizers of oral biofilm and can cause bacterial endocarditis. Candida albicans is present in the oral cavity in a commensal manner and also has the ability to form biofilm and cause oral candidiasis. The aim of this study was to evaluate the interactions between C. albicans with S. sanguinis and S. mitis biofilms and their influences in vivo on an experimental invertebrate model of Galleria mellonella. To study the interaction of C. albicans (ATCC 18804) with S. sanguinis (ATCC 7073) and S. mitis (ATCC 4945) monospecies and multispecies biofilms were formed of C. albicans and with micro-organisms (a concentration of 107 cells/ml) in the bottom of a 96-well plate for 48 h, incubated at 37 °C with 5% CO₂. After growth, biofilms were detached, and decimal dilutions were plated on selective media. After incubation for 48 h/37 °C the count of colony forming units per milliliter (CFU/mL) was obtained. Alongside, XTT salt colorimetric assays were carried in order to measure the metabolic activity of isolated and associated C. albicans biofilms, following reading at 492 nm, and the result expressed in absorbance (Abs). In the in vivo study, first the sublethal concentrations of microorganisms were determined, and inoculated into G. mellonella, and the effect of C. albicans, S. mitis and S. sanguinis in caterpillars was observed, evaluating the survival curve. Morphological evaluation of the biofilms was performed by scanning electron microscopy (SEM). The count of CFU/mL and metabolic activity were submitted to normality analisis, and as a normal distribution was observed, the results were statistically analyzed by Student's t test (for two variables) and Tukey (for three or more variables) considering statistical difference at p < 0.05. The G. mellonella survival curves data were analyzed by log-rank method. Streptococci influenced the reduction of biofilms of C. albicans and ....
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Romeiro, Rogério de Lima [UNESP]. "Aderência in vitro de Streptococcus sanguinis e Candida albicans em implantes dentários de superfície lisa ou tratada". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/103994.

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O objetivo desse trabalho foi analisar in vitro a aderência de Streptococcus sanguinis, Candida albicans e associações destes microrganismos com Streptococcus mutans às superfícies dos implantes dentários tratados com jateamento de fosfato de cálcio, anodização, duplo ataque ácido e os de superfície lisa, com ou sem a prévia incubação em saliva ou plasma sanguíneo. Foram selecionados 120 implantes, sendo 30 de cada superfície para cada microrganismo e associações estudadas. Para análise da aderência, foram preparadas suspensões de microrganismos contendo 106 células/ml em espectrofotômetro. Além disso, cada microrganismo e associações foram divididos em três grupos: em um, o implante foi removido da embalagem e colocado diretamente no caldo, em outro, foi previamente embebido em saliva humana por uma hora e no último em plasma humano, também por uma hora. Os implantes foram acondicionados separadamente em poços de placas de cultura de células contendo caldo sacarosado (placa in vitro) e a suspensão do microrganismo. Após 24h de incubação a 37 °C e 5% de CO2, os implantes foram lavados três vezes durante um minuto em solução salina estéril e colocados em sonicador com 10 ml de salina para dispersão das células aderidas. A seguir, foram realizadas diluições seriadas e semeaduras em meios de cultura específico para cada microrganismo. Após 48h de incubação a 37 °C e 5% de CO2, foi realizada a contagem de unidades formadoras de colônias (UFC/ml) e os dados foram submetidos a análise de variância (ANOVA), teste de tukey, com nível de significância de 5%. Para ilustrar a aderência dos microrganismos, foram selecionados o microrganismo Streptococcus sanguinis, e as associações Streptococcus sanguinis e Candida albicans e Streptococcus sanguinis, Streptococcus mutans...
The aim of this study has been to analyze, in vitro the adherence of Streptococcus sanguinis, Candida albicans and associations of those microorganisms with Streptococcus mutans to the surfaces of dental implants treated with calcium phosphate jetting, anodization, double acid attack and to those of smooth surface, with or without previous saliva or blood plasma incubation. Ten implants from each surface were selected for every studied microorganism and association. In order to analyze the adherence, suspensions of microorganisms bearing 106 viable cells/ml in spectrophotometer were prepared. Additionally, every microorganism and association was divided in three groups: in the first, an implant was removed from its wrap and put right away into the sauce; the second, it was previously drenched into saliva for one hour; and the last one, into plasma, for one hour, as well. The implants were separately placed in culturing plaque wells of cells containing saccharose sauce (in vitro plaque) and the microorganism’s suspension. After 24 hours of incubation time at 37 °C and 5% of CO2, the implants were taken washed three times for a minute in saline sterile solution and put in a sonicator holding 10 ml of saline in order to disperse adherent cells. Then, seriated dilutions were done, and sowing in culture media specific for each of the. After a 48hincubation time at 37°C and 5% of CO2, a counting was carried, of the colony forming units (UFC/ml) and the data were submitted to the ANOVA, Tukey test, at a significance level of 5%. To illustrate the adherence of the microorganisms, some samples were exposed to electronic sweeping microscopy. The results did show great microorganism adherence to the surfaces studied, mainly when associated forming a biofilm. The anodized surface... (Complete abstract click electronic access below)

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Veras, Idia Nara de Sousa. "AnÃlise do perfil morfolÃgico de candida tropicalis durante a formaÃÃo do biofilme sob influÃncia de metabÃlitos extracelulares de bactÃrias do gÃnero Streptococcus". Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=12793.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
BactÃrias e fungos sÃo encontrados juntos em uma infinidade de ambientes e, particularmente, na forma de biofilme, onde as espÃcies aderentes interagem atravÃs de diversos mecanismos de sinalizaÃÃo. Na cavidade oral, espÃcies de Candida coexistem com inÃmeras espÃcies bacterianas, e evidÃncias sugerem que bactÃrias podem modular a formaÃÃo de biofilme, bem como induzir a formaÃÃo de hifas e pseudo-hifas. Assim, caracterizar tais interaÃÃes Ã essencial para o entendimento da patogÃnese das doenÃas e, possivelmente, a descoberta de novas estratÃgias terapÃuticas. Nesse sentido, o objetivo principal deste trabalho foi avaliar, in vitro, os mecanismos envolvidos na interaÃÃo entre as bactÃrias Streptococcus oralis, Streptococcus sanguinis, Streptococcus parasanguinis e a levedura Candida tropicalis. No estudo foi analisado o efeito dos metabÃlitos extracelulares presentes no sobrenadante de C. tropicalis (SCT) sobre o biofilme prÃ-formado (6h) de S. oralis, S. sanguinis e S. parasanguinis. TambÃm foi avaliado o efeito dos metabÃlitos extracelulares de S. oralis (SSO), S. sanguinis (SSS) e S. parasanguinis (SSP) sobre o crescimento planctÃnico, formaÃÃo de biofilme e capacidade de filamentaÃÃo de C. tropicalis, utilizando apenas o sobrenadante da cultura de cada um dos estreptococos em diferentes concentraÃÃes (100, 50 e 25%). AlÃm disso, foi analisado o efeito dos metabÃlitos extracelulares dos estreptococos sobre o biofilme prÃ-formado (6h) de C. tropicalis. Para verificar o efeito dos metabÃlitos extracelulares foram utilizados dois mÃtodos: o mÃtodo turbidimÃtrico que se baseia na leitura da densidade Ãptica (OD) das suspensÃes celulares e a coloraÃÃo cristal violeta (CV) que permite a quantificaÃÃo indireta da formaÃÃo de biofilme atravÃs da coloraÃÃo com cristal violeta. Em seguida, foram examinadas as caracterÃsticas dos biofilmes, formados por 24 horas, atravÃs da anÃlise por microscopia Ãptica comum. Os resultados referentes ao biofilme foram submetidos ao ANOVA com pÃs-teste Bonferroni, com diferenÃa estatÃstica de p<0,01. Nossos resultados sugerem que substÃncias solÃveis produzidas por S. oralis, S. sanguinis e S. parasanguinis induzem a formaÃÃo de hifas de C. tropicalis sem interferir no crescimento planctÃnico. AlÃm de diminuir drasticamente o desenvolvimento do biofilme dessa levedura quando em contato com SSS e SSP. Tal fato reforÃa a ideia de que existe grande heterogeneidade dentro de biofilmes polimicrobianos, especialmente entre leveduras e bactÃrias. E que o resultado dessa interaÃÃo depende das condiÃÃes as quais estes micro-organismos serÃo submetidos.
Bacteria and fungi are found together in a multitude of environments, and particularly in the form of biofilm adherent species which interact through various signaling mechanisms. In the oral cavity, Candida species coexist with numerous bacterial species, and evidence suggests that bacteria can modulate biofilm formation as well as induce the formation of hyphae. Thus, to characterize such interactions are essential to the understanding of pathogenesis of diseases and possibly the discovery of new therapeutic strategies. In this sense, the main objective of this study was to evaluate, in vitro, the mechanisms involved in the interaction between bacteria Streptococcus oralis, Streptococcus sanguinis, and Streptococcus parasanguinis yeast Candida tropicalis. In the study the effect of extracellular metabolites present in the supernatant of C. tropicalis (SCT) on the pre-formed biofilm (6H) S. oralis, S. sanguinis and S. parasanguinis was analyzed. The effect of extracellular metabolites of S. oralis (SSO), S. sanguinis (SSS) and S. parasanguinis (SSP) on planktonic growth and biofilm formation capacity filamentation of C. tropicalis was also evaluated using only the supernatant culturing each of streptococci in different concentrations (100, 50 and 25%). Furthermore, the effect of extracellular metabolites of streptococci on the pre-formed biofilm (6h) of C. tropicalis were analyzed. To verify the effect of extracellular metabolites two methods were used: The turbidimetric method based on the reading of the optical density (OD) of cell suspension and coloring crystal violet (CV) which permits indirect quantification of the biofilm formation by staining with crystal violet. Then were examined characteristics of biofilms formed by 24 hours, through the analysis simple optical microscope. The results for the biofilm were subjected to ANOVA with Bonferroni post-test, with a statistical difference of p<0.01.Our results suggest that soluble substances produced by S. oralis, S. sanguinis and S. parasanguinis induce the formation of hyphae of C. tropicalis without interfering with planktonic growth.In addition to dramatically decrease biofilm development of oral yeast when in contact with SSP and SSS. This reinforces the idea that there is great heterogeneity within polymicrobial biofilms, especially between yeasts and bacteria. And the result of this interaction depends on the conditions which these micro-organisms will be subjected.

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Gurung, Ishwori. "Deciphering type IV pilus biology in the Gram-positive opportunistic pathogen Streptococcus sanguinis". Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/55879.

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Type IV pili (Tfp) are the paradigm of a large group of diverse and functionally versatile nanomachines, intensively studied in Gram-negative bacteria. However, details regarding the molecular mechanisms of Tfp biogenesis and/or mediated functions are still unclear. Thus, owing to the inherent lack of outer cell wall in Gram-positive bacteria, my PhD has focused on molecular characterisation of Tfp in a simpler such bacterium Streptococcus sanguinis. My work has shown that the naturally competent S. sanguinis produces bona fide retractable Tfp enabling twitching motility, but dispensable for competence. Unlike Gram-negative Tfp, we show that S. sanguinis Tfp are unusual since they are composed of two pilin proteins, a feature likely to be shared by other Gram-positive Tfp-expressing species. All the genes involved in Tfp biology in S. sanguinis are found within a pil locus encoding 21 proteins. A systematic genetic study highlighted that 10 proteins only are required for Tfp biogenesis, whilst another four modulate twitching motility. To enhance genetic manipulation of S. sanguinis, a markerless mutagenesis strategy was devised enabling us to make various mutations in situ, which helped us characterise some of these proteins further. Via this methodology, the last six genes of the pil locus were found to be completely dispensable for Tfp biology. To get an overall structural picture of Tfp in S. sanguinis, the structure of one of the major pilins (PilE1) was determined by NMR. Moreover, three pilin-like proteins within the pil locus were found to be minor Tfp components. Collectively, my work has established S. sanguinis as a robust Gram-positive model organism for studying Tfp, which paves way for interesting future studies.

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Hernández, Hernández Felipe. "Interacción de Streptococcus sanguinis en la viabilidad y crecimiento de Candida albicans en la cavidad oral". Tesis, Universidad de Chile, 2016. http://repositorio.uchile.cl/handle/2250/142376.

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Trabajo de Investigación Requisito para optar al Título de Cirujano Dentista
Introducción: Streptococcus sanguinis (S. sanguinis) es un colonizador primario de la biopelícula dental asociada a salud. Esta bacteria produce peróxido de hidrógeno (H2O2), un sub-producto del crecimiento y que es bacteriostático para otros streptococci orales, como Streptococcus mutans (S. mutans), quien, bajo condiciones determinadas de pH y disponibilidad de carbohidratos fermentables, se relaciona con el inicio y progresión de la caries dental. En este contexto, actualmente se propone una relación sinérgica entre S. mutans y Candida albicans (C. albicans), levadura comensal de la cavidad oral capaz de causar diversas patologías en humanos. El efecto de S. sanguinis, mediante la producción de (H²O²), en C. albicans no ha sido completamente estudiado. Según lo mencionado anteriormente, el objetivo de este estudio es determinar preliminarmente si existe modulación del crecimiento de C. albicans, en co-cultivo con S. sanguinis. Material y Métodos: Se utilizó S. sanguinis SK36, S. mutans ATCC 25175, C. albicans ATCC 90029 y un aislado clínico de C. albicans (P1-1) (proveniente de un niño con caries activas). Se realizaron ensayos de competencia en medio líquido y sólido de S. sanguinis o S. mutans con C. albicans (cepa de referencia o aislado clínico), se determinó pH y células viables para cada pareja en co-cultivo líquido. Inhibición del crecimiento en medio sólido fue evaluada según presencia de halo inhibitorio próximo a alguno de los microorganismos. Ensayos fueron incubados en microaerofilia a 37 ºC durante 48 h con agitación. Además, se realizó un test de concentración inhibitoria mínima (CIM) de (H²O²) para ambas cepas de C. albicans y también se determinó la cantidad de (H²O²) producida por S. sanguinis, de acuerdo a una curva estándar previamente diseñada. Los datos fueron analizados de manera descriptiva, comparando medianas entre distintos grupos y dentro de un mismo grupo. Resultados: En medio sólido, C. albicans produjo halo inhibitorio sobre S. sanguinis. En medio líquido, S. sanguinis y C. albicans (ATCC y P1-1) aumentaron su crecimiento en co-cultivo, respecto de su crecimiento aislado. Además, generaron siempre una alcalinización del medio, respecto al pH inicial. A 0,1 mM de (H²O²) la sobrevivencia de ambas cepas de C. albicans se redujo en un 70%, definiendo esta concentración como la CIM. La cantidad estimada de (H²O²) producida por S. sanguinis fue de 0,059 µM en todas las etapas de crecimiento. Conclusiones: De acuerdo a los resultados obtenidos y a las limitaciones del estudio, se puede concluir que S. sanguinis no inhibe el crecimiento de C. albicans. Asimismo, ambos podrían contribuir en mantener el pH del microambiente en niveles compatibles con salud oral. El co-cultivo de C. albicans con S. mutans podría beneficiar el crecimiento de la bacteria, en desmedro de la levadura. No obstante, cuando la levadura proviene de una biopelícula cariogénica, su relación con la bacteria podría tornarse más sinérgica. Entonces, el rol de C. albicans dentro del proceso de caries podría depender de la condición que presenta el microambiente, previo a la presencia de la levadura. El (H²O²) podría influir negativamente en el crecimiento de C. albicans, sin embargo, este efecto estaría supeditado a su concentración en el medio.
Adscrito a Proyecto U-inicia Difarp 40/13, VID, U. de Chile.

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Schmid, Franz-Gregor. "Einfluss von elektrischen Feldern auf die Effektivität der mechanischen Entfernung von Streptococcus-sanguinis-Biofilmen". [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979223873.

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Moraes, Julianna Joanna de Carvalho 1981. "Análise da função do sistema de dois componentes VicRK na biologia de Streptococcus sanguinis". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288676.

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Orientador: Renata de Oliveira Mattos-Graner
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Streptococcus sanguinis são colonizadores primários dos dentes reconhecidos como microrganismos comensais benéficos da cavidade bucal, pois são capazes de inibir o crescimento de espécies patogênicas, como Streptococcus mutans. S. sanguinis são comumente envolvidos em endocardite bacteriana, embora por mecanismos de patogenicidade ainda não conhecidos. Para colonizar os dentes ou tecidos cardíacos, S. sanguinis devem ser capazes de se estabelecer em biofilmes e de se adaptar às diversas condições de estresse ambiental decorridas da ação de microrganismos competidores e/ou das defesas do hospedeiro. A resposta bacteriana a condições de estresse ambiental é regulada por sistemas reguladores globais de transcrição de dois componentes (SDC), os quais são essenciais para modular o transcriptoma bacteriano durante os processos de colonização e infecção do hospedeiro. O genoma de S. sanguinis SK36 apresenta 14 desses sistemas. Através de análises de BLAST, identificou-se um SDC com alta similaridade ao sistema VicRK (vic de virulence control), o qual regula fatores de virulência e é conservado em diversas espécies de bactérias Gram-positivas, como S. mutans e Streptococcus pneumoniae. O objetivo deste trabalho foi caracterizar a função do sistema VicRK na biologia de S. sanguinis, através da análise dos efeitos da inativação de vicK em diversas características bacterianas possivelmente associadas à virulência e à formação de biofilmes. Para isto, foi construído um mutante knock-out do gene vicK a partir da cepa SK36, o qual foi designado SKvicK. SKvicK foi comparado à cepa selvagem quanto à capacidade de formação de biofilmes e quanto às características que influenciam na capacidade de colonização (hidrofobicidade, atividade autolítica e sensibilidade ao estresse oxidativo) em diferentes condições atmosféricas. Também foram comparados, entre as cepas, os padrões de expressão de genes com possível função de virulência, cujos ortólogos são regulados por VicRK nas espécies S. mutans e/ou S. pneumoniae. Estes incluem genes relacionados à formação de biofilmes e biogênese da parede celular (ssapcsB, lysM, gtfP), à resposta ao estresse oxidativo e produção de peróxido de hidrogênio (sodA, spxB, ccpA). A inativação de vicK inibiu claramente a formação inicial de biofilmes. Além disto, SKvicK demonstrou maior sensibilidade ao estresse oxidativo e maior hidrofobicidade celular. A inativação de vicK também inibiu, de forma significativa, a transcrição dos genes pcsB, lysM, spxB e comE. Estes dados indicam que VicRK regula diversas funções biológicas de S. sanguinis importantes para a colonização de humanos
Abstract: Streptococcus sanguinis are primary colonizers of the teeth and recognized as beneficial commensal microorganisms of the oral cavity because they are able to inhibit the growth of pathogenic species such as Streptococcus mutans. S. sanguinis are commonly involved in the infective endocarditis, although pathogenic mechanisms are still unknown. S. sanguinis are able to establish in biofilms and to adapt among various environmental stress conditions from competing microorganisms and/or from host defenses during colonization of enamel or endothelial tissues. Bacterial responses from environmental stress conditions are regulated by two-component global regulatory systems (TCS), which are essential to modulate the bacterial transcriptome during colonization and infection of the host. S. sanguinis SK36 genome contains at least 14 TCS. Through BLAST analyses, we identified a TCS with high similarity to VicRK system (vic from virulence control), which regulates virulence factors and is conserved in several species of gram-positive bacteria such as S. mutans and Streptococcus pneumoniae. The aim of this study was to characterize the role of VicRK system in S. sanguinis biology, by analyzing the effects of vicK inativation on several characteristics potentially associated with bacterial virulence and biofilm formation. For this purpose, vicK mutant gene knock-out was obtained from strain SK36 and it was designated SKvicK. SKvicK was compared to the wild-type strain about the ability to form biofilms and cellular traits which influence in the ability of host colonization (hydrophobicity, autolytic activity and sensitivity to oxidative stress) under diverse atmospheric conditions. Gene expression was also compared in the strains because these genes are potencially involved in virulence, whose orthologs are regulated by VicRK system in S. mutans and S. pneumoniae species. These include genes involved in biofilm formation and cell wall biogenesis (ssapcsB, lysM, gtfP), oxidative stress response and production of hydrogen peroxide (sodA, spxB, ccpA). The inactivation of vicK inhibited the initial formation of biofilms. Moreover, SKvicK showed increased sensitivity to oxidative stress and cell hydrophobicity. vicK gene inativation also signicantly down-regulated transcription of pcsB, lysM, spxB and comE. These data indicate that VicRK regulates several biological functions relevant for S. sanguinis colonization
Doutorado
Estomatologia
Doutor em Estomatopatologia

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Scott-Elliston, Ayana. "IN SEARCH OF A FUNCTION FOR AN UNCHARACTERIZED CONSERVED PROTEIN IN Streptococcus sanguinis SK36". VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4889.

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With the number of fully sequenced bacterial genomes increasing in the past 7 years, it has been discovered that a large percentage of the putative protein coding genes have no known function. This lack of knowledge leaves scientists with an incomplete understanding of bacteria. In this study, conserved hypothetical protein mutants from Streptococcus sanguinis SK36 were screened on solid media with various environmental conditions. From these screens, the candidate protein, SSA_2372, displayed a sensitivity to acidic conditions. Its homolog in Bacillus subtilis 168, BSU00030, also displayed a sensitivity to pH conditions at its acid tolerance extremes unlike its other homolog in Escherichia coli, YbcJ. When the growth rate and cell yield was acquired, the sensitivity was shown to be significant for both SSA_2372 and BSU00030 mutants. Through data mining, it was determined that Firmicutes in this homolog family COG2501 may function as a regulator for recombination protein F.

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Smith, John L. "CONTRIBUTION OF A CLASS II RIBONUCLEOTIDE REDUCTASE TO THE MANGANESE DEPENDENCE OF Streptococcus sanguinis". VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4936.

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Manganese-deficient Streptococcus sanguinis mutants exhibit a dramatic decrease in virulence for infective endocarditis and in aerobic growth in manganese-limited media. Loss of activity of a manganese-dependent, oxygen-dependent ribonucleotide reductase (RNR) could explain the decrease in virulence. When the genes encoding this RNR are deleted, there is no growth of the mutant in aerobic broth culture or in an animal model. Testing the contribution of the aerobic RNR to the phenotype of a manganese transporter mutant, a heterologous class II RNR from Lactobacillus leichmannii called NrdJ that requires B12 rather than manganese as a cofactor was previously introduced into an RNR mutant of S. sanguinis. Aerobic growth was only partially restored. Currently, we sought to improve NrdJ-dependent growth by (i) amending the medium to increase cellular levels of B12; (ii) characterizing a spontaneous mutant of the NrdJ-complemented strain with improved aerobic growth; and (iii) altering this strain through further genetic manipulation.

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Palma, Ana Luiza do Rosário [UNESP]. "Análise de fatores de virulência de Candida albicans na associação com Streptococcus mitis e Streptococcus sanguinis in vitro e in vivo". Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/147988.

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O objetivo foi avaliar as interações entre Candida albicans (ATCC 18804) com Streptococcus mitis (49456) e Streptococcus sanguinis (10556) in vitro e in vivo avaliando-se a possível influência destas associações, na expressão de genes, na filamentação e formação de biofilme de Candida albicans. A formação de biofilme, foi realizado mono e multiespécie em placa de 96 poços por 48 h à 37 ºC com 5% CO2. Os biofilmes foram desagregados e diluídos para semeadura em ágar e após incubação as UFC/mL foram contadas. A filamentação de C. albicans, in vitro foi realizada em placas de 24 poços e in vivo em Galleria mellonella, com análise histológica e contagem de UFC/mL. A avaliação da expressão gênica de ALS1, ALS3, BRC1, CPH1, EFG1 e HWP1, foi realizada por PCR em tempo real utilizando o gene normalizador ACT1. Os resultados da UFC/mL (p < 0.05), demonstrou que o biofilme de C. albicans monoespécie apresentou maior crescimento, quando comparado com o biofilme associado com S. mitis (p = 0,001) ou com S. sanguinis (p = 0,001). A filamentação in vitro demonstrou que a interação com S. mitis inibiu a filamentação de C. albicans (p = 0,0006), entretanto, a interação com S. sanguinis não inibiu (p = 0,1554). Os genes ALS1, ALS3 e HWP1 foram super expressos na interação com S. mitis. A interação com S. sanguinis, promoveu super expressão dos genes ALS3 e HWP1. Os genes BRC1, CPH1 e EFG1 foram super expressos na interação com S. mitis e sub expressos, na interação com S. sanguinis. Não houve diferença estatística nos estudos in vivo de filamentação e UFC/mL. Conclui-se que in vitro, S. mitis e S. sanguinis foram capazes de inibir a formação de biofilme de C. albicans. Assim como a interação com S. mitis inibiu a sua filamentação. A interação com S. mitis parece aumentar o fator de virulência de C. albicans, quanto a expressão dos genes de aderência ALS1, ALS3 e HWP1, bem como na associação com S. sanguinis (ALS3 e HWP1). Os genes de formação de biofilme, BRC1, CPH1 e EFG1, na interação com S. mitis promoveu aumento do fator de virulência.
The objective was to evaluate the interactions between Candida albicans (ATCC 18804) with Streptococcus mitis (49456) and Streptococcus sanguinis (10556) in vitro and in vivo evaluating the possible influence of these associations, in the expression of genes, in the filamentation and biofilm formation of Candida albicans. Biofilm formation was performed mono- and multispecies in 96-well plate for 48 h at 37 ºC with 5% CO2. Biofilms sonicated and diluted for sowing on agar and after incubation the colonies counted to obtain the colony forming units (CFU/mL). The filamentation in vitro was performed in 24-well plate and in vivo Galleria mellonella, with histological and CFU/mL. The evaluation of gene expression ALS1, ALS3, BRC1, CPH1, EFG1 and HWP1 was performed by real-time PCR using the normalizing gene ACT1. The results of CFU/ml (p<0.05), found that C. albicans biofilm monoespécie showed increased growth, as compared to the biofilm associated with S. mitis (p = 0.001) and S. sanguinis (p = 0.001). The filamentation in vitro demonstrated that the interaction with S. mitis inhibited C. albicans filamentation (p = 0.0006), interaction with S. sanguinis could not (p = 0.1554). The ALS1, ALS3, HWP1 gene, were superexpressed in S. mitis interaction. Interaction with S. sanguinis, promoted overexpression of ALS3 and HWP1 genes. The BRC1 genes, CPH1 and EFG1 were super expressed in interaction with S. mitis and sub expressed when there was interaction with S. sanguinis. There was no statistical difference in the in vivo studies of filamentation and CFU/mL. It follows that in vitro, S. mitis and S. sanguinis were able to inhibit the formation of C. albicans biofilms. Like the interaction with S. mitis inhibited its filamentation. The interaction with S. mitis appears to increase the virulence factors of C. albicans. ALS1, ALS3, HWP1 as the expression of adhesion genes, and as well as in association with S. sanguinis (ALS3 and HWP1). Biofilm formation genes, BRC1, CPH1 and EFG1 in interaction with S. mitis promoted increased virulence factor.

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Palma, Ana Luiza do Rosário. "Análise de fatores de virulência de Candida albicans na associação com Streptococcus mitis e Streptococcus sanguinis in vitro e in vivo /". São José dos Campos, 2016. http://hdl.handle.net/11449/147988.

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Orientador: Antonio Olavo Cardoso Jorge
Banca: Luciane Dias de Oliveira
Banca: Mariella Vieira Pereira Leão
Resumo: O objetivo foi avaliar as interações entre Candida albicans (ATCC 18804) com Streptococcus mitis (49456) e Streptococcus sanguinis (10556) in vitro e in vivo avaliando-se a possível influência destas associações, na expressão de genes, na filamentação e formação de biofilme de Candida albicans. A formação de biofilme, foi realizado mono e multiespécie em placa de 96 poços por 48 h à 37 ºC com 5% CO2. Os biofilmes foram desagregados e diluídos para semeadura em ágar e após incubação as UFC/mL foram contadas. A filamentação de C. albicans, in vitro foi realizada em placas de 24 poços e in vivo em Galleria mellonella, com análise histológica e contagem de UFC/mL. A avaliação da expressão gênica de ALS1, ALS3, BRC1, CPH1, EFG1 e HWP1, foi realizada por PCR em tempo real utilizando o gene normalizador ACT1. Os resultados da UFC/mL (p < 0.05), demonstrou que o biofilme de C. albicans monoespécie apresentou maior crescimento, quando comparado com o biofilme associado com S. mitis (p = 0,001) ou com S. sanguinis (p = 0,001). A filamentação in vitro demonstrou que a interação com S. mitis inibiu a filamentação de C. albicans (p = 0,0006), entretanto, a interação com S. sanguinis não inibiu (p = 0,1554). Os genes ALS1, ALS3 e HWP1 foram super expressos na interação com S. mitis. A interação com S. sanguinis, promoveu super expressão dos genes ALS3 e HWP1. Os genes BRC1, CPH1 e EFG1 foram super expressos na interação com S. mitis e sub expressos, na interação com S. sanguinis. Não houve... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract :The objetive was to evaluate the interactions between Candida albicans (ATCC 18804) with Streptococcus mitis (49456) and Streptococcus sanguinis (10556) in vitro and in vivo evaluating the possible influence of these associations, in the expression of genes, in the filamentation and biofilm formation of Candida albicans. Biofilm formation was performed mono- and multispecies in 96-well plate for 48 h at 37 ºC with 5% CO2. Biofilms sonicated and diluted for sowing on agar and after incubation the colonies counted to obtain the colony forming units (CFU/mL). The filamentation in vitro was performed in 24-well plate and in vivo Galleria mellonella, with histological and CFU/mL. The evaluation of gene expression ALS1, ALS3, BRC1, CPH1, EFG1 and HWP1 was performed by real-time PCR using the normalizing gene ACT1. The results of CFU/ml (p<0.05), found that C. albicans biofilm monoespécie showed increased growth, as compared to the biofilm associated with S. mitis (p = 0.001) and S. sanguinis (p = 0.001). The filamentation in vitro demonstrated that the interaction with S. mitis inhibited C. albicans filamentation (p = 0.0006), interaction with S. sanguinis could not (p = 0.1554). The ALS1, ALS3, HWP1 gene, were superexpressed in S. mitis interaction. Interaction with S. sanguinis, promoted overexpression of ALS3 and HWP1 genes. The BRC1 genes, CPH1 and EFG1 were super expressed in interaction with S. mitis and sub expressed when there was interaction with S. sanguinis. There was no statistical difference in the in vivo studies of filamentation and CFU/mL. It follows that in vitro, S. mitis and S. sanguinis were able to inhibit the formation of C. albicans biofilms. Like the interaction with S. mitis inhibited its filamentation. The interaction with S. mitis appears to increase the virulence factors of C. albicans. ALS1, ALS3, HWP1 as the ...(Resumo completo, clicar acesso eletrônico abaixo).
Mestre

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Mabboux, Florence. "Matériaux implantaires dentaires et adhérence de Streptococcus sanguinis et de Streptococcus constellatus : caractérisation et rôle des propriétés physico-chimiques de surface". Lyon 1, 2004. http://www.theses.fr/2004LYO10236.

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Dans cette étude in vitro, nous avons évalué (i) l’intérêt de 3 approches différentes dans la caractérisation des propriétés de surface de biomatériaux implantaires dentaires (Titane et Ti-6A1-4V) et de Streptococcus sanguinis et de Streptococcus constellatus, avec et sans salive, (ii) l’adhérence de ces deux espèces sur ces biomatériaux, recouverts de salive, par l’analyse d’images, (iii) l’influence de la topographie de surface et de procédés de désinfection/stérilisation sur les propriétés de surface du Titane et du TA6V et sur l’adhérence bactérienne. Nos résultats montrent un comportement similaire du titane et de son alliage, le rôle déterminant du choix de la méthode dans la caractérisation physico-chimique de la surface des bactéries et des solides. Ils confirment l’intérêt de la détermination des interactions acide-base et électrostatiques pour une meilleure compréhension de l’adhésion bactérienne sur les matériaux implantaires
In this in vitro study, we have evaluated (i) the interest of 3 different approaches in the characterization of surface properties of implant dental biomaterials (Titanium and Ti-6A1-4V) and of Streptococcus sanguinis and Streptococcus constellatus, with and without saliva, (ii) the number of adherent bacterial cells on these biomaterials , coated with saliva, by analysis of images, (iii) the influence of surface topography and processes of disinfection /sterilisation on surface properties of Titanium, TA6V and on bacterial adherence. Our results show a similar behaviour of titanium and its alloy, the determining role of the method in the physico-chemical characterization of surface properties of bacteria and solids. They confirm the usefulness of determining acid-base interactions and electrostatic properties for a better understanding of streptococcal adhesion on implant dental materials

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Jara, Muñoz Rocío del Pilar. "Evaluación in vitro del efecto antibacteriano de cinco propóleos peruanos sobre cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556)". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2014. http://hdl.handle.net/10757/528160.

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The target was evaluate the “in vitro” antibacterial effect about five peruvian propolis on strains of Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556), Having an experimental study design “in vitro” made in laboratorie of Microbiology of the Peruvian University of Applied Sciences. Materials and Methods: Sample size were about ten holes for each of the five extracts of propolis, either for Streptococcus mutans and Streptococcus sanguinis individualy. The antibacterial effect was developed with the technical “Agar overlay interference test”, which is used 200ml of Agar BHI homogenized with bacteria indispensably (a bottle for bacteria). This agar is distributed in the plates, once solidified the holes are made with 150μL of different kinds of propolis and the control group called Clorhexidine 0.12%. Completed this process is placed in the anaerobiosis chamber on 37º C, for 72 hours. Finally, the measurement of the inhibitory halo is made. Results: The methanolic extract of propolis of Oxapampa-Perú present inhibition halos in larger averaging of 33.15 + 3.26 mm against strains of Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556), their average was about 23.23 + 0.82mm. In case of 4 extracts of commercial, just 3 of them (tincture of propolis Farmagel, Madre Nature y Kaita®), had bacterian activity in front of the studies strains. In all cases the antibacterian activity is less than positive control. Conclusions: The methanolic extract of propolis of Oxapampa-Peru, made in the laboratory has better antibacterian activity than commercial extracts against strains of Streptococcus mutans (ATTC 25175) and Streptococcus sanguinis (ATCC 10556). About the four commercial propolis evaluated on this study, propolis tincture Farmagel, Kaita®, Madre Natura and Max propolis tincture, only three of this have antibacterial activity against strains of de Streptococcus mutants (ATCC 25175) and Streptococcus sanguinis (ATCC 10556).
El objetivo fue evaluar in vitro el efecto antibacteriano de cinco propóleos peruanos sobre cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556) teniendo un diseño de estudio experimental in vitro, realizado en el laboratorio de Microbiología de la Universidad Peruana de Ciencias Aplicadas. Materiales y métodos: se comparó el efecto antibacteriano de cuatro marcas comerciales de propóleo Tintura de propóleo Farmagel, Tintura de propóleo Max, Madre Natura, Kaita® y un extracto metanólico de propóleo de Oxapampa, el cual se elaboró en el laboratorio de Bioquímica de la UPC, como control (+) la clorhexidina al 0.12%. Para este estudio se utilizó 10 pocillos por cada extracto de propóleo, para el Streptococcus mutans y para el Streptococcus sanguinis individualmente. Se desarrolló con la técnica “Agar overlay interference test”, para lo cual se utilizó 200ml de Agar BHI homogenizado con las bacterias de manera independiente (un frasco por bacteria). Se distribuyó este agar en las placas, una vez solidificado se realizaron los pocillos con 150μL de los distintos tipos de propóleo y para el grupo control, se utilizó clorhexidina al 0.12%. Terminado este proceso se colocó en la cámara de anaerobiosis a 37°C, durante 72 horas. Por último, se realizó la medición del halo inhibitorio con una regla Vernier. Resultados: El extracto metanólico de propóleo de Oxapampa presentó halos de inhibición de mayor tamaño con una media de 33.15 + 3.26 mm frente a las cepas de Streptococcus mutans (ATCC 25175), para el Streptococcus sanguinis (ATCC 10556) su media fue de 23.23 + 0.82 mm. En el caso de los 4 extractos de propóleo comerciales, sólo 3 de ellos (Tintura de propóleo Farmagel, Madre Natura y Kaita®), tuvieron actividad antibacteriana frente a las cepas estudiadas, en todos los casos la actividad antibacteriana es menor que el control (+). Conclusiones: El extracto metanólico de propóleo de Oxapampa elaborado en el laboratorio tiene mayor actividad antibacteriana que los extractos comerciales frente a las cepas Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556). De los 4 propóleos comerciales evaluados en el estudio, Tintura de propóleo Farmagel, Kaita®, Madre Natura y Tintura de propóleo Max, sólo tres de ellos tiene actividad antibacteriana frente a las cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556).
The target was evaluate the “in vitro” antibacterial effect about five peruvian propolis on strains of Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556), Having an experimental study design “in vitro” made in laboratorie of Microbiology of the Peruvian University of Applied Sciences. Materials and Methods: Sample size were about ten holes for each of the five extracts of propolis, either for Streptococcus mutans and Streptococcus sanguinis individualy. The antibacterial effect was developed with the technical “Agar overlay interference test”, which is used 200ml of Agar BHI homogenized with bacteria indispensably (a bottle for bacteria). This agar is distributed in the plates, once solidified the holes are made with 150μL of different kinds of propolis and the control group called Clorhexidine 0.12%. Completed this process is placed in the anaerobiosis chamber on 37º C, for 72 hours. Finally, the measurement of the inhibitory halo is made. Results: The methanolic extract of propolis of Oxapampa-Perú present inhibition halos in larger averaging of 33.15 + 3.26 mm against strains of Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556), their average was about 23.23 + 0.82mm. In case of 4 extracts of commercial, just 3 of them (tincture of propolis Farmagel, Madre Nature y Kaita® ), had bacterian activity in front of the studies strains. In all cases the antibacterian activity is less than positive control. Conclusions: The methanolic extract of propolis of Oxapampa-Peru, made in the laboratory has better antibacterian activity than commercial extracts against strains of Streptococcus mutans (ATTC 25175) and Streptococcus sanguinis (ATCC 10556). About the four commercial propolis evaluated on this study, propolis tincture Farmagel, Kaita® , Madre Natura and Max propolis tincture, only three of this have antibacterial activity against strains of de Streptococcus mutants (ATCC 25175) and Streptococcus sanguinis (ATCC 10556).

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Munive, Mendez María Claudia del Pilar y Quispe Flavia Jimena Cardenas. "Evaluación in vitro del efecto inhibitorio de la terapia fotodinámica sobre Streptococcus mutans (ATCC® 25175) y Streptococcus sanguinis (ATCC® 10556) en presencia y ausencia de riboflavina". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/651668.

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Objetivo: Evaluar el efecto inhibitorio de la terapia fotodinámica (TPD) con Diodo Emisor de Luz (LED) azul sobre Streptococcus mutans y Streptococcus sanguinis en presencia y ausencia de riboflavina (E - 101). Materiales y métodos: Se realizaron cuatro tratamientos en presencia y ausencia de la exposición de luz LED azul y riboflavina al 0.5% sobre Streptococcus mutans y Streptococcus sanguinis. Las bacterias fueron cultivadas en medio BHI y la unidad de medida utilizada fue las unidades formadoras de colonias (UFC/ml). Resultados: La fotoactivación con luz LED azul a 40 segundos no tuvo efecto inhibitorio sobre S. mutans y S. sanguinis. Sin embargo, al realizar la terapia fotodinámica en presencia de riboflavina, se observó que el crecimiento bacteriano fue menor (p<0.05). Asimismo, se identificó que la viabilidad bacteriana de S. sanguinis es menor que la de S. mutans, con un 40% y 66% respectivamente. Conclusiones: Se concluye que la riboflavina tiene un efecto inhibitorio significativo sobre la viabilidad bacteriana de S. mutans y S. sanguinis.
Objective: To evaluate the inhibitory effect of photodynamic therapy (TPD) with blue Light Emitting Diode (LED) on Streptococcus mutans and Streptococcus sanguinis in presence and absence of riboflavin (E-101). Materials and methods: Four treatments were performed in presence and absence of blue LED and riboflavin (0.5%) exposure on Streptococcus mutans and Streptococcus sanguinis. The bacteria were grown in BHI medium and the unit of measurement used was the colony forming units (CFU / ml). Results: Photoactivation with blue LED light at 40 seconds had no inhibitory effect on S. mutans and S. sanguinis. However, when performing photodynamic therapy in presence of riboflavin, it was observed that bacterial growth was lower (p <0.05). Likewise, it was identified that bacterial viability of S. sanguinis is lower than S. mutans, with 40% and 66% respectively. Conclusions: It is concluded that riboflavin has a significant inhibitory effect on the bacterial viability of S. mutans and S. sanguinis.
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Camargo, Tarsila Mendes de 1982. "Caracterização do sistema de dois componentes SptRS de Streptococcus sanguinis com possível papel na viabilidade em saliva humana : Characterization of the component system SptRS of Streptococcus sanguinis with putative role in bacterial viability in human saliva". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288672.

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Orientador: Renata de Oliveira Mattos Graner
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Streptococcus sanguinis é colonizador comensal da superfícies dos dentes e patógeno comum de endocardite bacteriana em seres humanos. A colonização da cavidade oral por S. sanguinis depende, em parte, de interações de superfície bacteriana com componentes adsorvidos na superfície dos dentes (que são principalmente de origem salivar) chamado película adquirida (PA). Além disso, os produtos do metabolismo aeróbio de S. sanguinis, por exemplo, peróxido de hidrogênio, inibe o crescimento de espécies de estreptococos concorrentes e promove a liberação de DNA genômico, um componente da matriz extracelular do biofilme dental. S. sanguinis se adapta fisiologicamente a saliva durante suas fases de colonização na cavidade oral, que provavelmente envolve alterações dinâmicas em seu transcriptoma. Transcriptomas bacterianos são regulados pelos sistemas de dois componentes (SDC), que consistem de uma membrana sensora de histidina quinase (HK) e um regulador de resposta intracelular cognato (RR). A HK sofre autofosforilação sob estímulos específicos e fosforila RR cognato, que por sua vez se liga às regiões reguladoras de genes alvo, induzindo ou reprimindo a transcrição. S. sanguinis SK36 tem um ortólogo de SDC SptRS designado (de Saliva persistência) envolvidos na sobrevivência e persistência na saliva humana em S. pyogenes. O objetivo deste estudo foi investigar o papel do SDC SptRS na biologia de S. sanguinis. Para isso, mutantes knockout de sptR (SKsptR-) e sptS (SKsptS-) foram obtidos a partir da cepa SK36. Mutantes sptRS foram analisados quanto ao crescimento planctônico e biofilme em meio suplementado ou não com saliva humana. Liberação de DNA, produção de peróxido de hidrogênio, autólise e sensibilidade ao stresse oxidativo também foram analisados nestas cepas. Alterações da transcrição dos genes associados a fenótipos observados foram avaliadas por meio de RT - qPCR. Sob aerobiose, mutantes sptRS formaram cadeias muito longas e agregados de cocos. O crescimento mais lento em comparação com SK36 também foi observado. Por outro lado, um aumento significativo (cerca de 2 vezes ) em biomassa do biofilme foram encontrados em mutantes em comparação com SK36 na presença de saliva. Consistentemente, mutantes liberaram 2 a 5 vezes mais DNA ao meio e produziram 2 a 3 vezes mais de H2O2 em comparação com a cepa selvagem. Não foram observadas alterações em autólise induzida por alta temperatura. Os mutantes mostraram um aumento da tolerância ao stresse oxidativo, mas reduções de 1 a 2 logs na contagem de células (ufc / ml ) durante a incubação em saliva. A análise de RT- qPCR revelou que SptRS regula negativamente os genes que codificam as hidrolases mureína (SSA_0094 e cwdP); aumentos de 2,14 e 14,7 vezes nestes genes foram respectivamente observados em mutantes SKsptR-. Além disso, nos mutantes sptRS foram observados aumentos de 15,5 a 27,9 vezes em transcritos do gene spxB, que codifica a oxidase piruvato necessária para a produção de H2O2. Outros genes associados com a produção H2O2 também foram afetados nos mutantes [ackA (aumento de 5,3-9,7 vezes); tpK (aumento de 12,19 vezes)]. Este estudo fornece evidências de que SptRS regula as funções de S. sanguinis de estabelecimento em biofilmes associados à produção de H2O2 e liberação de DNA, e participa da sobrevivência das bactérias na saliva humana
Abstract: Streptococcus sanguinis is commensal colonizer of tooth surfaces and common pathogen of bacterial endocarditis in humans. The colonization of the oral cavity by S. sanguinis depends in part, on bacterial surface interactions with components adsorbed to tooth surfaces (which are primarily of salivary origin) called acquired pellicle (AP). In addition, products of S. sanguinis aerobic metabolism, e.g. hydrogen peroxide, inhibits the growth of competitor streptococcal species and promotes the release of genomic DNA, a component of the extracellular matrix of dental biofilms. S. sanguinis physiological adaptation to saliva during the stages of colonization of the oral cavity, likely involves dynamic changes in its transcriptome. Bacterial transcriptomes are regulated by two-component systems (TCS), which consist of a membrane sensor histidine kinase (HK) and a cognate intracellular response regulator (RR). The HK undergoes autophosphorylation under specific stimuli and phosphorylates the cognate RR, which in turn binds to regulatory regions of target genes, inducing or repressing transcription. S. sanguinis SK36 strain has an orthologue of the TCS designated SptRS (of Saliva persistence) involved in survival and persistence in human saliva in S. pyogenes. The aim of this study was to investigate the role of SptRS TCS in S. sanguinis biology. To that purpose, knockout mutants of sptR (SKsptR-), and sptS (SKsptS-) genes were obtained in strain SK36. SptRS mutants were analyzed regarding to planktonic and biofilm growth in medium supplemented or not with human saliva. DNA release, production of hydrogen peroxide, autolysis and sensitivity to oxidative stress were also analyzed in these strains. Transcriptional changes in genes associated with observed phenotypes were then assessed by RT-qPCR. Under aerobiosis, sptS/R mutants formed extremely long chains and aggregates of cocci. Slower growth compared to SK36 was also observed. On the other hand, significant increases (about 2-fold) in biofilm biomass were found in mutants compared to SK36 in the presence of saliva. Consistently, mutants released 2 to 5-fold more DNA to medium and produced 2 to 3-fold more H2O2 compared to parent strain. No changes were observed in autolysis induced by high temperature. Mutants showed increased tolerance to oxidative stress, but reductions of 1 to 2 logs in cell counts (cfu/ml) during incubation in saliva. RT- qPCR analysis revealed that SptRS negatively regulates genes encoding murein hydrolases (SSA_0094 and cwdP); increases of 2.14 and 14.7-folds in these genes were respectively observed in SKsptR mutants. In addition, 15.5 to 27.9-fold increases in sptR/S mutants were observed in spxB transcripts, which encode pyruvate oxidase required for H2O2 production. Other genes associated with H2O2 production were also affected in mutants [ackA (5.3 to 9.7-fold increases; tpK (12.19-fold increase)]. This study provides evidence that SptRS regulates functions for S. sanguinis establishment in biofilms associated with H2O2 production and DNA release, and participates in bacterial survival in human saliva
Doutorado
Microbiologia e Imunologia
Doutora em Biologia Buco-Dental

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López, Rodríguez Gabriela del Pilar. "Evaluación in vitro del efecto antibacteriano de la Camellia sinensis (té verde) frente al Streptococcus mutans (ATCC 25175) y al Streptococcus sanguinis (ATCC) 10556)". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2014. http://hdl.handle.net/10757/337212.

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Objective: The aim of this study was to evaluate the antibacterial effect of Camellia sinensis (green tea) on Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC10556). Materials and Methods: The methanolic extract of green tea (commercial and bulk) was examined on Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC10556), using the well assay method. A total of 24 plates for the first extract (Commercial) and the same amount for the extract No. 2 (Bulk) were used and were divided into groups of 12 disks for each bacterium, with a total of 4 disks per group. In addition, each plate contained 3 disks embedded with tea and 1 disc with 0.12% chlorhexidine as a control group. Results: It was found antibacterial effect in both methanolic extracts of green tea. No statistically significant differences when comparing the natural green tea with the other extract, in every single microorganism. A p value of 0.18 and 0.63 respectively were obtained. The methanol extract of the commercial green tea had better antibacterial effect than the second extract with an average of 19.72 mm, for the second extract of green tea was 18.1 mm against Streptococcus mutans, whereas for Streptococcus sanguinis was 17.94mm and 16.46 mm respectively. The minimum inhibitory concentration (MIC) for the commercial and bulk extract was 0.08 gr/ml against Streptococcus mutans and 0.08 gr/ml and 0.25 gr/ml against the strains of Streptococcus sanguinis respectively. Conclusions: Both methanolics extracts, commercial and bulk have anti Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC10556) activity in vitro. The activity of commercial tea had better effects than the bulk methanolic extract.
Objetivo: Evaluar in vitro el efecto antibacteriano de la Camellia sinensis (té verde) frente al Streptococcus mutans (ATCC 25175) y al Streptococcus sanguinis (ATCC10556). Materiales y métodos: Se probaron dos extractos de té verde, uno comercial y otro a granel. Se utilizaron 24 discos para el primer extracto (Comercial) y la misma cantidad para el segundo extracto metanólico (Granel), se dividieron en grupos de 12 discos para cada bacteria, con un total de 4 placas petri por cada uno. Además, cada placa contenía 3 discos embebidos de té y 1 disco con Clorhexidina al 0.12% como grupo control. Estas muestras fueron analizadas con el método de difusión en agar con discos y los halos de inhibición se midieron a las 72 horas. Resultados: Se encontró efecto antibacteriano para ambos extractos probados. El promedio del halo de inhibición para el extracto de té verde comercial fue de 19.72 mm y para el extracto de té verde a granel fue de 18.1 mm frente al Streptococcus mutans, mientras que para el Streptococcus sanguinis la media obtenida fue de 17.94 mm y 16.46 mm respectivamente. Con respecto a la Concentración mínima inhibitoria (CMI), para el caso de Streptococcus mutans se determinó una CMI de 0.08 gr/ml para el extracto comercial y al extracto a granel. Mientras que para el caso de Streptococcus sanguinis la CMI fue de 0.08 gr/ml para el extracto comercial y de 0.25 gr/ml para el extracto a granel. Conclusiones: Ambos extractos metanólicos de té verde presentaron efecto antibacteriano contra las cepas del Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC10556). El té verde comercial fue el que presentó mayor efecto antibacteriano que el extracto a granel.

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Morales, Castro Valentina Alejandra. "Recuento de Streptococcus sanguinis, Streptococcus gordonii y Streptococcus mutans en muestras de saliva y placa bacteriana supragingival de niños escolares de 6 y 7 años de edad con diferente actividad cariogénica". Tesis, Universidad de Chile, 2016. http://repositorio.uchile.cl/handle/2250/147239.

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Trabajo de Investigación Requisito para optar al Título de Cirujano Dentista
La caries dental es un proceso localizado de origen multifactorial que se inicia luego de ocurrida la erupción dentaria, determinando el reblandecimiento del tejido duro del diente y que puede evolucionar hasta la formación de una cavidad. La cavidad oral contiene muchas bacterias, de las cuales son las acidogénicas las que están involucradas en el proceso carioso, a la par que también existen bacterias alcalogénicas contrarrestando esta acidogenicidad. El propósito de este trabajo es determinar la correlación entre bacterias alcalogénicas y salud oral presentes en niños de 6 y 7 años de edad. Material y métodos: Se tomaron muestras a 110 niños de 6 y 7 años de edad de saliva y placa bacteriana del sector norte de la RM, recolectando muestras de placa y muestras de saliva. Se realizó examen dentario determinando COPD/ceod. Se procedió a realizar extracción de ADN de cada muestra y determinar la cantidad de Streptococcus sanguinis, Streptococcus mutans y Streptococcus gordonii mediante qPCR. Los datos se analizaron y correlacionaron según la experiencia de caries y el número de copias por mililitros de cada bacteria analizada. Resultados: La abundancia de S. sanguinis en placa y saliva basándose en la mediana es mayor para el grupo “libres de caries” (CF) que para “caries activa” (CA), sin embargo, los resultados no son significativos. S. gordonii muestra mayor abundancia en el grupo CA que en CF siendo significativo solo para muestras de placa. En el caso de S. mutans, el recuento fue mayor en el grupo CA que en el CF para placa y saliva siendo ambos resultados significativos. Conclusiones: Las bacterias S. sanguinis y S. gordonii no son exclusivas de sujetos libres de caries, estando presentes en todos los grupos evaluados con diferente actividad cariogénica. Existe una tendencia de mayor abundancia de S. sanguinis en placa y saliva en niños CF. Por otro lado, S. gordonii no tiene una asociación positiva con sujetos libres de caries. Hay presencia de S. mutans en todos los grupos, pero su mayor recuento reside en sujetos CA, existiendo una asociación positiva significativa. Por último, la herramienta qPCR puede ser útil al contribuir a nuestro conocimiento sobre la composición de la biopelícula dental.
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Romeiro, Rogério de Lima. "Aderência in vitro de Streptococcus sanguinis e Candida albicans em implantes dentários de superfície lisa ou tratada /". São José dos Campos : [s.n.], 2009. http://hdl.handle.net/11449/103994.

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Orientador: Antonio Olavo Cardoso Jorge
Banca: José Luiz De Lorenzo
Banca: Cristiane Yumi Koga Ito
Banca: Jamil Awad Shibli
Banca: Leonardo Marchini
Resumo: O objetivo desse trabalho foi analisar in vitro a aderência de Streptococcus sanguinis, Candida albicans e associações destes microrganismos com Streptococcus mutans às superfícies dos implantes dentários tratados com jateamento de fosfato de cálcio, anodização, duplo ataque ácido e os de superfície lisa, com ou sem a prévia incubação em saliva ou plasma sanguíneo. Foram selecionados 120 implantes, sendo 30 de cada superfície para cada microrganismo e associações estudadas. Para análise da aderência, foram preparadas suspensões de microrganismos contendo 106 células/ml em espectrofotômetro. Além disso, cada microrganismo e associações foram divididos em três grupos: em um, o implante foi removido da embalagem e colocado diretamente no caldo, em outro, foi previamente embebido em saliva humana por uma hora e no último em plasma humano, também por uma hora. Os implantes foram acondicionados separadamente em poços de placas de cultura de células contendo caldo sacarosado (placa in vitro) e a suspensão do microrganismo. Após 24h de incubação a 37 °C e 5% de CO2, os implantes foram lavados três vezes durante um minuto em solução salina estéril e colocados em sonicador com 10 ml de salina para dispersão das células aderidas. A seguir, foram realizadas diluições seriadas e semeaduras em meios de cultura específico para cada microrganismo. Após 48h de incubação a 37 °C e 5% de CO2, foi realizada a contagem de unidades formadoras de colônias (UFC/ml) e os dados foram submetidos a análise de variância (ANOVA), teste de tukey, com nível de significância de 5%. Para ilustrar a aderência dos microrganismos, foram selecionados o microrganismo Streptococcus sanguinis, e as associações Streptococcus sanguinis e Candida albicans e Streptococcus sanguinis, Streptococcus mutans... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The aim of this study has been to analyze, in vitro the adherence of Streptococcus sanguinis, Candida albicans and associations of those microorganisms with Streptococcus mutans to the surfaces of dental implants treated with calcium phosphate jetting, anodization, double acid attack and to those of smooth surface, with or without previous saliva or blood plasma incubation. Ten implants from each surface were selected for every studied microorganism and association. In order to analyze the adherence, suspensions of microorganisms bearing 106 viable cells/ml in spectrophotometer were prepared. Additionally, every microorganism and association was divided in three groups: in the first, an implant was removed from its wrap and put right away into the sauce; the second, it was previously drenched into saliva for one hour; and the last one, into plasma, for one hour, as well. The implants were separately placed in culturing plaque wells of cells containing saccharose sauce (in vitro plaque) and the microorganism's suspension. After 24 hours of incubation time at 37 °C and 5% of CO2, the implants were taken washed three times for a minute in saline sterile solution and put in a sonicator holding 10 ml of saline in order to disperse adherent cells. Then, seriated dilutions were done, and sowing in culture media specific for each of the. After a 48hincubation time at 37°C and 5% of CO2, a counting was carried, of the colony forming units (UFC/ml) and the data were submitted to the ANOVA, Tukey test, at a significance level of 5%. To illustrate the adherence of the microorganisms, some samples were exposed to electronic sweeping microscopy. The results did show great microorganism adherence to the surfaces studied, mainly when associated forming a biofilm. The anodized surface... (Complete abstract click electronic access below)
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El-rami, Fadi. "A Systems Biology Approach For Predicting Essential Genes and Deciphering Their Dynamics Under Stress In Streptococcus sanguinis". VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/4925.

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Infectious diseases are the top leading cause of death worldwide. Identifying essential genes, genes indispensable for survival, has been proven indispensable in defining new therapeutic targets against pathogens, major elements of the minimal set genome to be harnessed in synthetic biology, and determinants of evolutionary relationships of phylogenetically distant species. Thus, essentiality studies promise valuable revenues that can decipher much of biological complexities. Taking advantage of the available microbial sequences and the essentiality studies conducted in various microbial models, we proposed a framework for the prediction of essential genes based on our experimentally verified knowledge of the pathways involved in three essential xiv functions: genetic information processing, cell wall biosynthesis, and energy metabolism. We investigated physiological pathways in Kyoto Encyclopedia of Genes and Genomes (KEGG) database and developed a bioinformatics approach to predict essential genes in 13 different microbial species. Our in silico findings matched to a high degree the experimental data derived from essentiality studies conducted on the same microbial models, providing insights about the microbial lifestyles, including energy resources, cell wall structure, and ecological preferences, but not virulence tools and mechanisms. Furthermore, we believe that essential genes have survived the evolutionary purifying selection due to their evolved capacity to re-wire genetic and protein networks in response to any emerging stress. In this sense, an environmental specificity (stress) provides a dominant determinant of an essential gene set. The new challenge was understanding the contribution of the essential genome in S. sanguinis to the coping mechanisms to different clinically relevant stress factors, namely temperature elevation (43oC) and sub-inhibitory concentration of ampicillin, an abundantly prescribed antibiotic for prophylaxis and treatment against S. sanguinis. The current project investigated the transcriptomic and proteomic profiles of essential genes and proteins, using RNA-seq and mass spectrometry respectively, under the impact of the two stressors separately, to elucidate the essential genome and proteome dynamics on a temporal basis and define “pathogenesis signatures” as potential therapeutic targets. We believe that the current findings will help characterize a bacterial model for studying the dynamics of essential genes and assist in designing evidence-based guidelines for drug prescription in clinical practice.

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Thomé, Thaís. "Análise in vitro do efeito do monômero antibacteriano MDPB sobre a adesão bacteriana à resina composta". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/23/23134/tde-20102005-083931/.

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Um novo monômero, brometo de metacriloiloxidodecilpiridínio (MDPB), com efeito antibacteriano e capacidade de co-polimerizar com outros monômeros, foi apresentado por Imazato, Torii e Tsuchitani (1993). Este estudo avaliou a adesão bacteriana, em 16, 40 e 64 horas, à resina composta contendo ou não o monômero antibacteriano MDPB. A adesão foi testada para Streptococcus sanguinis e Streptococcus sobrinus. Após as amostras terem sido submetidas à incubação, o biofilme foi coletado e a contagem de UFCs foi realizada. Os dados foram comparados pelo método ANOVA complementado por teste de Tukey. Os resultados demonstraram que, para o S. sanguinis, a adesão sobre o MDPB foi significativamente maior (p<0.05) quando comparado ao controle em 16 horas, mas diminuiu significativamente em 40 horas, não apresentando diferenças quando comparado ao controle neste tempo (p<0.01). Para o S. sobrinus, o controle apresentou aumento significativo da adesão bacteriana em 64 horas quando comparado com 16 horas (p<0.01), sendo significativamente maior que para o MDPB em 64 horas (p<0.05). Assim, o estudo mostrou que o MDPB é capaz de inibir a adesão de S. sobrinus sem interferir na adesão do S. sanguinis. Portanto, nas condições deste estudo os resultados sugerem que a incorporação do MDPB a resinas compostas pode ser de importância na prevenção de cáries secundárias favorecendo a adesão de bactérias comensais em detrimento de bactérias com potencial cariogênico.
A new antibacterial monomer, Methacryloyloxydodecylpyridinium bromide (MDPB), with antibacterial property and ability to co-polymerize with other monomers, was introduced by Imazato, Torii and Tsuchitani (1993). This study aimed to analyze the effect of MDPB on bacterial adherence to resin composites containing or not MDPB. Streptococcus sanguinis and Streptococcus sobrinus were used. The biofilms were collected from the samples and the colony forming units (CFUs) were counted after 16, 40 e 64 h of incubation. The data were compared by ANOVA complemented by the Tukeys test. The results showed that the adhesion of S. sanguinis to MDPB-containing resin composite was significantly higher (p<0.05) than to control samples at 16 h, but significantly diminished at 40 h, reaching values similar to those of control samples (p<0.01). The adherence of S. sobrinus to control samples significantly increased throughout the experimental time (p<0.01) and was considerably higher than to MDPB at 64 h (p<0.05). Thus, the study showed that MDPB is capable of inhibit adhesion of S. sobrinus with no interference on the adhesion of S. sanguinis. Thus, at the conditions of this study we suggest that MDPB incorporated to resin composites could be of importance to prevent secondary caries favoring adhesion of commensal bacteria and impairing adhesion of cariogenic bacteria.

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Alvitez, Jurado Maricielo y Cabanillas Veronica Lucia Cardenas. "Evaluación in vitro del efecto antibacteriano del extracto metanólico del Lepidium meyenii (maca) sobre cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556)". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/654707.

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Objetivo: Evaluar el efecto antibacteriano in vitro del extracto metanólico del Lepidium meyenii en sus tres ecotipos (maca roja, amarilla y negra) sobre cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556). Materiales y Métodos: Este estudio in vitro utilizó pocillos embebecidos del extracto metanólico del Lepidium meyenii en sus tres ecotipos colocados en 7 placas petri que contenían cepas de cultivos. La Concentración mínima inhibitoria (CMI) fue evaluada por la técnica de Kirby Bauer y la concentración mínima bactericida (CMB) mediante el Recuento de Unidades Formadoras de Colonia (UFC). Los halos de inhibición se midieron en mm y se registraron mediante estadística descriptiva media y desviación estándar. Resultados: Frente al Streptococcus mutans (ATCC 25175), la maca roja tuvo una media (+- d.e) de 13.5 ± 0 .60 mm, MIC de 125.0μg/ml y MBC de 62.5 μg/ml; la maca negra 13.3 ± 0.53 mm, 125.0μg/ml y 62.5 μg/ml, respectivamente; y, la amarilla, 12 ± 0.27 mm, 250.0 μg/ml y 125.0 μg/ml, respectivamente. Frente al Streptococcus sanguinis (ATCC 10556), la media (+- d.e) de la maca roja fue 17.6 ± 0.23 mm, MIC de 62.5μg/ml y MBC de 31.3 μg/ml; la maca negra 19.6 ± 0.44 mm, 62.5μg/ml y 31.3 μg/ml, respectivamente; y, la amarilla 14.8 ± 0.26mm, 31.3 μg/ml y 15.6 μg/ml, respectivamente. Conclusión: Existe efecto antibacteriano del extracto metanólico de Lepidium meyenii en sus tres ecotipos sobre los microorganismos Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556).
Objective: To evaluate the in vitro antibacterial effect of methanolic extract of Lepidium meyenii in its three ecotypes (red, yellow and black maca) against Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556). Materials and Methods: This in vitro study used wells embedded in methanolic extract of Lepidium meyenii in its three ecotypes, placed on 7 petri discs containing the bacteria samples. The Minimum inhibitory concentration (MIC) was evaluated using the Kirby Bauer technique and the minimum bactericidal concentration (MBC) using the colony forming unit (CFU). Inhibition halos were measured in mm and analyzed using descriptive statistics and standard deviation. Results: Against Streptococcus mutans (ATCC 25175), the red maca had a mean result (±sd) of 13.5±0.60 mm, 125.0ug/ml MIC and 62.5ug/ml MBC; the black maca was 13.3±0.53 mm, 125.0ug/ml MIC and 62.5 ug/ml MBC; and the yellow maca was 12±0.27 mm, 250.0 ug/ml and 125.0 ug/ml, respectively. Against Streptococcus sanguinis (ATCC 10556), the mean (±d.e) of the red maca was 17.6±0.23 mm, 62.5ug/ml MIC and 31.3 ug/ml MBC; the black maca was 19.6±0.44 mm, 62.5ug/ml MIC and 31.3 ug/ml MBC, and the yellow maca was 14.8±0.26 mm, 31.3 ug/ml and 15.6 ug/ml, respectively. Conclusion: Exists an antibacterial effect of methanolic extract of Lepidium meyenii in its three ecotypes against Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556).
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Huertas, Campos Mariana Cecilia. "Evaluación in vitro del efecto antibacteriano y citotóxico del extracto metanólico de Physalis peruviana (capulí) sobre cepas de Streptococcus mutans (ATCC25175), Streptococcus sanguinis (ATCC 10556)". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2015. http://hdl.handle.net/10757/581919.

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Objective: The aim of this study was to evaluate the antibacterial effect of Physalis peruviana on Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556). Materials y Methods: The present in vitro experimental study was to determinate the antibacterial effect of the fruit of Physalis Peruviana’s methanolic extract against Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556) and Clorhexidine (CHX) as control group, the minimum inhibitory concentration (MIC) and citotoxicity. For the antibacterial assay, 14 wells were prepared from the extract and Clorhexidine 0.12% as a positive control for each bacteria. The method used was agar diffusion test preparing wells with the experimental solutions cultivated in anaerobic conditions for 48 hours at 37ºC, after this time, the growth inhibition was analysed in milimiters. with wells. Results: It was found antibacterial effect of the metanolic extract of the fruit in Streptococcus mutans and Streptococcus sanguinis. In the first group, the inhibicion halo of the extract was 19.15mm ± 1.83 and for Clorhexidine 25.78mm ± 2.27, while for the group of Streptococcus sanguinis, the Physalis Peruviana’s extract had 18.56mm ± 1.59 for inhibicion halos and 22.92mm ± 1.96 for Clorhexidine. On the other hand, the extract’s MIC was 50mg/ml. Finally, the methanolic extract of Physalis peruviana inhibited 50% of viability cells (CC50) at 241.01ug/ml concentration. Conclusions: The methanolic extract of Physalis Peruviana had antibacterial effect against Streptococcus mutans and Streptococcus sanguinis. Besides, this fruit wasn’t citotoxic for Jurkat’s line cell.
Objetivo: evaluar in vitro el efecto antibacteriano del extracto metanólico de Physalis peruviana sobre cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556). Materiales y Métodos: el presente estudio fue de tipo experimental in vitro. Se evaluó el efecto antibacteriano del extracto metanólico del fruto de Physalis peruviana frente a cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556) y la Clorhexidina (CHX) como grupo control, determinando la concentración mínima inhibitoria (CMI) y citotoxicidad. Para realizar la actividad antibacteriana se trabajó con una muestra de 14 pocillos por grupo, mediante el método de difusión en agar con pocillos. Por otro lado, para la MIC se utilizó el método de dilución en caldo en medio Brain Heart infusión Broth (BHI) y para evaluar la citotoxicidad se empleó la línea celular Jurkat mediante el ensayo de MTT. Resultados: se observaron halos de inhibición de 19.15mm ± 1.83 para el extracto de physalis peruvina y 25.78mm ± 2.27 para la clorhexidina sobre Streptococcus mutans, mientras que para el grupo de Streptococcus sanguinis, se observaron halos de inhibición de 18.56mm ± 1.59 del extracto de la planta y 22.92mm ± 1.96 para la clorhexidina. Por otro lado, la MIC del extracto fue de 50mg/ml. Finalmente, el extracto metanólico de la Physalis peruviana inhibió la viabilidad celular al 50% (CC50) en una concentración de 241.01ug/ml. Conclusiones: el extracto metanólico de Physalis Peruviana tuvo efecto antibacteriano sobre cepas de Streptococcus mutans y Streptococcus sanguinis. Además, no fue citotóxico para la línea celular Jurkat.
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Meza, Ana Stefany. "In vitro evaluation of bacterial adhesion and bacterial viability of Streptococcus mutans, Streptococcus sanguinis, Porphyromonas gingivalis and the abutment surface of the dental implants of titanium and zirconium". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2017. http://hdl.handle.net/10757/622856.

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Objetivo: Evaluar in vitro la adherencia y viabilidad bacteriana de Streptococcus mutans, Streptococcus sanguinis y Porphyromonas gingivalis en la superficie del abutment de los implantes de titanio y zirconio. Métodos: Se prepararon seis muestras, divididas en dos grupos, G1: 3 abutment de titanio y G2: 3 abutment de zirconio con tornillos de fijación, cada grupo fue embebido en tubos con cultivos bacterianos, posteriormente las muestras se incubaron a 37 ° C en condiciones de anaerobiosis. La adherencia bacteriana se evaluo en UFC y la viabilidad bacteriana con prueba colorimétrica MTT. Resultados: Se constató que el abutment de titanio tiene mayor adherencia de S. mutans (190.90 UFC / ml), mientras que P. gingivalis muestra mayor viabilidad bacteriana (73.22%). Para el abutment de zirconio se observó mayor adhesión, para el caso de S. mutans (331.82 UFC / ml) y mayor viabilidad en la cepa de S. sanguinis (38.42%). En los tornillos de fijación, en el titanio se observó que la mayor adherencia para el caso de S. sanguinis (132.5 UFC / ml) y mayor viabilidad para S. mutantes (78.04%). Mientras que para el tornillo de zirconio se observa que S. mutans tiene mayor adherencia y viabilidad con (145.5 UFC / ml) y ( 57.38%) respectivamente. Conclusiones: Existe mayor adherencia bacteriana en los abutment de zirconio, sin embargo, la viabilidad bacteriana es menor. Mientras, para el caso del abutment de titanio se encontró que existe menor adherencia pero mayor viabilidad bacteriana. Se sugiere ampliar con los estudiantes que tienen mayor número de muestra.
Objective: To evaluate in vitro the adherence and bacterial viability of Streptococcus mutans, Streptococcus sanguinis and Porphyromonas gingivalis on the abutment surface of titanium and zirconium implants. Methods: Six samples were prepared, divided into two groups, G1: 3 abutment of titanium and G2: 3 abutment of zirconium with their fixation screws, each group was embedded in tubes with bacterial cultures, subsequently the samples were incubated at 37 ° C in conditions of anaerobiosis. Bacterial adherence was evaluated in CFU and bacterial viability with the MTT colorimetric test. Results: It was found that in the titanium abutment there is greater adherence of S. mutans (190.90 CFU / ml), while P. gingivalis shows greater bacterial viability (73.22%). For the zirconia abutment, greater adhesion was observed, for the case of S. mutans (331.82 CFU / ml) and greater viability in the S. sanguinis strain (38.42%). In the fixing screws, titanium showed the highest adherence for S. sanguinis (132.5 CFU / ml) and greater viability for S. mutants (78.04%). While for the zirconium screw it is observed that S. mutans has greater adherence and viability with (145.5 CFU / ml) and (57.38%) respectively. Conclusions: There is greater bacterial adherence in zirconium abutment, however, bacterial viability is lower. Meanwhile, in the case of titanium abutment it was found that there is less adherence but greater bacterial viability. It is suggested to expand with students who have a larger sample number.

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Camere, Colarossi Rosella Vanina. "Evaluación in vitro del efecto antibacteriano y citotóxico del extracto metanólico de semilla y pulpa de la Myrciaria dubia (camu camu) sobre cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556)". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2015. http://hdl.handle.net/10757/581744.

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Objective: The aim of this study was to evaluate the antibacterial and cytotoxic effect of the methanol extract of the seed and pulp of Myrciaria dubia (camu camu) against Streptococcus mutans (ATCC 25175) and Streptococcus sanguinis (ATCC 10556). Materials and Methods: For the present in vitro experimental study two methanolic extracts were prepared from the seed and pulp of Myrciaria dubia (camu camu) to be tested against Streptococcus mutans and Streptococcus sanguinis. Ten independents tests were prepared for each type of extract, using Clorhexidine at 0.12% solution as a positive control. The method used was agar diffusion test preparing wells with the experimental solutions cultivated in anaerobic conditions for 48 hours at 37°C, after this time the growth inhibition halo was analysed in millimeters using a vernier. Meanwhile, the Minimum Inhibitory Concentration (MIC) and the cytotoxic effect (CC50) over Jurkat T cell line was found. Results: The methanolic seed extract had more antibacterial effect over Streptococcus mutans with an inhibitory halo of 21.36mm ± 6.35, while the pulp had 16.20mm ± 2.08. For the Streptococcus sanguinis group the inhibitory halo were 19.21mm ± 5.18 and 19.34mm ± 2.90 for the methanolic seed and pulp extract respectively. The MIC for the pulp extract was 125µg/ml for both strains, whereas for the seed antibacterial activity was observed even at low concentrations. Finally the CC50 for the seed extract was at a higher concentration than 800 µg/ml and 524.37µg/ml for the pulp exactract. Conclusions: The methanolic seed and pulp extract of Myrciaria dubia (camu camu) had antibacterial effect against Streptococcus mutans and Streptococcus sanguinis. These extracts were not cytotoxic.
Objetivo: evaluar in vitro el efecto antibacteriano y citotóxico del extracto metanólico de semilla y pulpa de la Myrciaria dubia (camu camu) sobre cepas de Streptococcus mutans (ATCC 25175) y Streptococcus sanguinis (ATCC 10556). Materiales y métodos: el estudio fue experimental in vitro. Se utilizaron los extractos metanólicos de la semilla y pulpa de Myrciaria dubia (camu camu) sobre las cepas de Streptococcus mutans y Streptococcus sanguinis. Para cada extracto se realizaron 10 pruebas independientes y como control positivo se utilizó la Clorhexidina al 0.12%. Se utilizó el método de difusión en agar con pocillos con las soluciones experimentales en condiciones de anaerobiosis por 48 horas a 37°C, para luego proceder a la lectura de los diámetros del halo de inhibición con un vernier. Asimismo, se halló la concentración mínima inhibitoria (CMI) de los extractos y se determinó el efecto citotóxico (CC50) sobre la línea celular Jurkat. Resultados: el extracto metanólico de la semilla tuvo mayor efecto antibacteriano sobre el Streptococcus mutans con halos de 21.36mm ± 6.35, mientras que la pulpa tuvo 16.20mm ± 2.08. Para el grupo de Streptococcus sanguinis, se observó que los halos de inhibición fueron de 19.21mm ± 5.18 y 19.34mm ± 2.90 para los extractos de semilla y pulpa respectivamente. La CMI del extracto de la pulpa se encontró en la concentración de 125µg/ml para ambas cepas, mientras que para el caso de la semilla se pudo observar actividad antibacteriana aún en bajas concentraciones. Finalmente, la CC50 del extracto de la semilla fue en una concentración mayor a 800 µg/ml y de la pulpa fue 524.37µg/ml. Conclusiones: se determinó que existe efecto antibacteriano del extracto metanólico de la semilla y pulpa de la Myrciaria dubia (camu camu) sobre cepas de Streptococcus mutans y Streptococcus sanguinis. Los extractos metánolicos de este fruto no fueron citotóxicos.

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Oliveira, Thaís Rossini de 1989. "Estudo da participação dos reguladores de transcrição gênica VicRK e CovR na susceptibilidade de Streptococcus sanguinis à opsonização pelo sistema complemento". [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288674.

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Orientadores: Renata de Oliveira Mattos Graner, Flávia Sammartino Mariano Rodrigues
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Made available in DSpace on 2018-08-26T11:30:42Z (GMT). No. of bitstreams: 1 Oliveira_ThaisRossinide_M.pdf: 1438459 bytes, checksum: a127a667898930e41649ac3faebb8d1a (MD5) Previous issue date: 2014
Resumo: Streptococcus sanguinis é uma espécie pioneira comensal das superfícies dos dentes, que também está envolvida na endocardite infecciosa. Sua alta prevalência na cavidade oral indica capacidade de adaptar-se e sobreviver a diversos fatores de defesa presentes nesse nicho. Para se adaptar ao ambiente e a fatores do hospedeiro, as bactérias utilizam-se de sistemas reguladores de transcrição de dois componentes (SDC), que modulam a regulação de genes em respostas a diferentes estímulos. Neste estudo avaliou-se o papel do SDC VicRK e CovR, na susceptibilidade de S. sanguinis a opsonização pelo sistema complemento. Para isso, foram analisados os níveis de deposição de C3b / iC3b na presença de soro em um total de sete cepas clínicas de S. sanguinis, e as frequências de fagocitose por polimorfonucleares (PMNs) do sangue humano foram comparados entre as cepas S. sanguinis SK36 e mutantes knockout de vicK (SKvic) e covR (SKcov), genes estes que codificam componentes VicK e CovR, respectivamente. A cepa de S. mutans U159 foi utilizada como referência. Resumidamente, as cepas foram incubadas com soro humano a 2 ou 20% por 30 min (37 ° C, 10% de CO2), lavadas, e a presença de C3b associada à superfície foi detectado utilizando anticorpos anti-C3b humano (conjugado com FITC), sendo quantificadas por citometria de fluxo. Para avaliar as frequências de fagocitose por PMNs, as cepas foram incubadas com sangue humano durante tempos de 5, 15, 30 e 60 min (37 ° C, 10% de CO2), fixadas e coradas com Giemsa. PMNs com bactérias intracelulares, foram contados utilizando um microscópio de luz (1000 x) e os resultados expressos em relação a análise de um total de 200 PMNs. Resultados: As percentagens de deposição de C3b em SKvic, SKcov e SK36 foram de 11,3 (± 2,61), 40,2 (± 1,46) e 37,9% (± 3,97), respectivamente. Percentagem de superfície C3b foi significativamente menor em cepas de S. sanguinis em comparação a cepa de S.mutans (Kruskal Wallis, p <0,05), e em SKvic em comparação a cepa SK36 (Kruskal Wallis, p <0,05). As frequências médias de fagocitose por PMNs não foram afetadas, e foram 88, 99,3 e 99% em SKvic, SKcov e SK36, respectivamente. Conclusão: a inativação do VicK, mas não de CovR, reduz a deposição de C3b em S. sanguinis SK36. Cepas de S. sanguinis também são menos suscetíveis a deposição de C3b em comparação a S. mutans
Abstract: Streptococcus sanguinis is a commensal pioneer species of the tooth surfaces, which is also involved in infectious endocarditis. Its high prevalence in the oral cavity indicates ability to survive to several host defense factors present in the oral niches. To sense and respond to environmental and host factors, bacteria apply regulatory two-component systems (TCSs), which modulate gene transcription in response to different stimuli. This study evaluated the role of TCS VicRK and CovR in S. sanguinis susceptibility to opsonization by the complement system. To this aim, a total of seven S. sanguinis strains were analyzed, and levels of deposition of C3b/iC3b on the present of serum, and the frequencies of phagocytosis by polymorphonuclear (PMNs) in human blood were compared between parent S. sanguinis strain SK36 and knockout mutants of vicK (SKvic) and covR (SKcov) (genes encoding VicK and CovR components, respectively). S. mutans strain U159 was used as reference. Briefly, strains were incubated with 2 or 20% of human serum during 30 min (37°C, 10%CO2), washed, and the presence of surface-associated C3b was detected using anti-human C3b antibodies (FITC conjugated), which were quantified by flow cytometry. To assess the frequencies of phagocytosis by PMN, strains were incubated with human blood during 5, 15, 30 and 60 min (37°C, 10% CO2), fixed and stained with Giemsa. PMN with intracellular bacteria were counted using a light microscope (1000 x) and expressed in relation to a total of 200 PMN analyzed. Results: The percentages of C3b deposition on SKvic, SKcov and SK36 were 11.3 (± 2.61), 40.2 (± 1.46) and 37.9% (± 3.97), respectively. Percentage of surface C3b was significantly lower in S. sanguinis strains compared to S. mutans (Kruskal Wallis, p < 0.05), and in SKvic compared to SK36 (Kruskal Wallis, p < 0.05). The mean frequencies of phagocytosis by PMN was not affected, and were 88, 99.3 and 99% in SKvic, SKcov and SK36, respectively. Conclusion: the inactivation of the vicK, but not of covR, reduces the deposition of C3b in S. sanguinis SK36. S. sanguinis strains are also less susceptible to C3b deposition compared to S. mutans
Mestrado
Microbiologia e Imunologia
Mestra em Biologia Buco-Dental

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40

Manrique, Holguín Paola Cecibel. "Evaluación in vitro del efecto antimicrobiano y citotóxico del extracto metanólico dracontium loretense (jergón sacha) sobre cepas de candida albicans (ATCC®10231™), Streptococcus mutans (ATCC®25175™) y Streptococcus sanguinis (ATCC®10556™)". Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2017. http://hdl.handle.net/10757/622864.

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Objetivo: Evaluar in vitro la actividad antimicrobiana y citotóxica del extracto metanólico de Dracontium loretense (Jergón Sacha) sobre cepas de Candida albicans (ATCC ® 10231™), Streptococcus mutans (ATCC®25175) y Streptococcus sanguinis (ATCC®25175). Materiales y Métodos: Se preparó el extracto metanólico de Dracontium loretense a diferentes concentraciones. Se evaluó la actividad antimicrobiana de Dracontium loretense sobre cepas de Candida albicans, Streptococcus mutans y Streptococcus sanguinis mediante el método difusión en agar. La citotoxicidad del extracto (CC50) se determinó haciendo uso de la línea celular MDCK. Resultados: El extracto metanólico de Dracontium loretense tuvo efecto inhibidor sobre Streptococcus mutans y Streptococcus sanguinis con halos de inhibición de 14.10 ± 0.65mm y 15.58 ± 0.43mm, respectivamente. Sin embargo, no se observó efecto inhibidor sobre Candida albicans. La concentración mínima inhibitoria (CMI) del extracto metanólico de Dracontium loretense sobre las cepas de Streptococcus mutans fue de 500µg/ml. Mientras que la CMI sobre Streptococcus sanguinis fue de 62.5µg/ml. La citotoxicidad de este extracto sobre la línea celular MDCK se evaluó en un rango de 0 a 900µg/ml, mostrando que no es citotóxico en altas concentraciones. Conclusiones: Se observó que Dracontium loretense (Jergón Sacha) presentó efecto antibacteriano sobre las cepas de Streptococcus mutans y Streptococcus sanguinis. Sin embargo, no presentó efecto antimicótico sobre cepas de Candida albicans. El extracto de esta planta no es citotóxico aún en altas concentraciones
Objective: The aim to this study was to evaluate the antimicrobial and cytotoxic effect of the methanol extract of Dracontium loretense (Jergon Sacha) against Candida albicans (ATCC®10231), Streptococcus mutans (ATCC®25175) and Streptococcus sanguinis (ATCC®25175). Materials and Methods: The methanolic extract of Dracontium loretense was prepared at different concentrations. The antimicrobial activity of Dracontium loretense was evaluated on strains of Candida albicans, Streptococcus mutans and Streptococcus sanguinis by the agar diffusion method. The cytotoxicity of the extract (CC50) was determined using the MDCK cell line. Results: The results showed that the methanolic extract of Dracontium loretense had inhibitory effect on Streptococcus mutans and Streptococcus sanguinis with inhibition halos of 14.10 ± 0.65mm and 15.58 ± 0.43mm, respectively. However, no inhibitory effect was observed on Candida albicans. The minimum inhibitory concentration (MIC) of the methanolic extract of Dracontium loretense on strains of Streptococcus mutans was 500 μg/ml. While the MIC on Streptococcus sanguinis was 62.5μg / ml. The cytotoxicity of the methanolic extract of Dracontium loretense on the MDCK cell line was evaluated in a range of 0 to 900 μg / ml, showing that it is not cytotoxic in high concentrations. Conclusion: The experimental findings showed that Dracontium loretense (Jergon Sacha) presented an antibacterial effect on the strains of Streptococcus mutans and Streptococcus sanguinis. However, it did not present an antifungal effect on strains of Candida albicans. The extract of this plant is not cytotoxic even in high concentrations.

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41

Brañez, Reyes Katherine. "Evaluación del efecto antibacteriano in vitro del extracto de Stevia rebaudiana sobre el Actinomyces viscosus y Streptococcus sanguinis, bacterias iniciadoras en la formación de biofilm dental". Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2017. https://hdl.handle.net/20.500.12672/6575.

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Determina la actividad antibacteriana del extracto de Stevia rebaudiana (S. rebaudiana) frente a Streptococcus sanguinis (S. sanguinis) y Actinomyces viscosus (A. viscosus). Desarrolla la prueba de sensibilidad en placa de agar con discos, previo al desarrollo de la prueba se activaron las cepas de S. sanguinis y A. viscosus en placas de Agar Tripticasa soya (TSA) y agar sangre respectivamente e incubada a 37 ºC por 48 horas a S. sanguinis y 7 días en condiciones de anaerobiosis a A. viscosus. Posteriormente se colocó en las 10 placas de agar sangre como de TSA un inóculo de 100 µL, que fue estandarizado al 0,5 de la escala de Mc Farland y sembrado por diseminación. Seguidamente se colocaron los discos de 6 mm de diámetro de forma equidistante, cargados con 10 µL de las diferentes concentraciones del extracto y se procedió a la incubación. Encuentra que las concentraciones de 15, 30, 50, 60 y 120 mg/ml presentan un halo de inhibición promedio de 6,8; 8,2; 8,2; 8,3; 8,1mm respectivamente, para el caso de S. sanguinis. Las concentraciones de 15, 30, 50,60 y 120 mg/ml presentan un halo de inhibición promedio 7,2; 9,65; 9,20; 8,05; 7,95 respectivamente para el caso de A. viscosus. La prueba de Kruskal Wallis determina que existe diferencia estadísticamente significativa de los promedios entre las concentraciones. Concluye que el extracto de S. rebaudiana no presenta actividad antibacteriana para las cepas de S. sanguinis, pero si presenta poca actividad antibacteriana sobre cepas de A. viscosus para las concentraciones de 30 y 50 mg/ml.
Tesis

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42

Hale, John D. F. y n/a. "Small bacteriocins produced by Streptococcus mutans and Streptococcus sanguis". University of Otago. Department of Microbiology & Immunology, 2006. http://adt.otago.ac.nz./public/adt-NZDU20060905.144149.

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Dental caries is the most common bacterial disease of humans and occurs when oral bacteria produce acids, following their fermentation of dietary carbohydrates. This acid can then cause a localised demineralisation of the tooth surface. A group of seven species of bacteria, collectively known as the mutans streptococci, have been predominantly implicated in the onset of dental caries. In particular, Streptococcus mutans and Streptococcus sobrinus have been shown to be the main aetiological agents of this disease in humans. Most attempts to control the microbial component of caries target these bacteria. The past 50 years has provided considerable information about the pathogenesis of dental caries, the likely route and time of transmission of cariogenic bacteria to susceptible hosts and possible ways of either treating or controlling the onset of this disease. In regards to the latter, many techniques (such as the use of tooth brushes, mouth washes, dental floss and tooth paste) for the control of plaque build-up exist and the examples listed are generally part of a daily routine. However, these techniques need to be applied regularly, and as such only highly-motivated individuals generally experience improved oral health. Therefore, the search for more effective less labour-intensive approaches continues. One area of research is into the potential application of small ribosomally-synthesised antimicrobial peptides, known as bacteriocins. Bacteriocins generally inhibit closely-related species that occupy the same ecological niche. Their relatively-specific targeting, plus the fact that many are remarkably heat and chemically-stable molecules, makes them excellent candidates for possible anti-caries applications. Numerous bacteriocins produced by the lactic acid bacteria have now been identified. Most can be broadly categorised into one of four main classes, of which Class I, the lantibiotics and Class II, the small (<10 kDa) non-modified peptides, contain the most examples. Many screens for anti-mutans streptococcal (MS) bacteriocins have been carried out and it appears that the best source of anti-MS bacteriocins are the mutans streptococci themselves. Research in this laboratory has identified examples of anti-mutans streptococcal bacteriocins produced by both mutans streptococci and non-mutans streptococci. The present study investigated the anti-MS inhibitors produced by two streptococcal strains, S. mutans N and Streptococcus sanguis K11. During the course of this study a third strain, S. mutans UA159, was also studied for its bacteriocinogenic properties. Although S. sanguis K11 produces anti-mutans streptococcal inhibitory activity, this appears only effective against Streptococcus rattus. In addition however, the inhibitory activity of this strain is also directed against all tested strains of Streptococcus agalactiae and ca. 50% of Streptococcus pyogenes. In the present study a 5069 Da novel inhibitory agent (sanguicin K11) was characterised and shown responsible for this unusual inhibitory spectrum. Through reverse genetics the sanK11 locus was identified and shown to encode a Class II type bacteriocin, the first shown to be produced by S. sanguis. Following screens of additional S. sanguis, sanK11 was shown to be present only in strains producing the same type of inhibitory pattern (P-type) as strain K11. The cysteine residues at positions 7 and 38 of the sanguicin K11 propeptide were shown to form a disulphide bridge essential for sanguicin K11 inhibitory activity. S. mutans N and eight other S. mutans strains have been found to have what appears to be the same inhibitory spectrum, which includes members of the mutans streptococci and several other oral streptococcal species. One strain (UA140) of the eight has previously been shown to produce the lantibiotic mutacin I and the non-lantibiotic mutacin IV. S. mutans N was known to produce the non-lantibiotic mutacin N. The current study set out to investigate how two strains, apparently producing completely different bacteriocins could have the same inhibitory spectrum. Reverse genetics identified the mutacin N structural gene (mutN) and mutagenesis studies showed that this bacteriocin was responsible only for the inhibitory activity against mutans streptococci. Further sequencing around the mutN locus identified a second bacteriocin-like locus (mutO) adjacent to mutN. mutO was also identified to have anti-mutans streptococcal inhibitory activity and because of the close proximity of mutO and mutN and given the homology they share with other known two-peptide bacteriocins it seemed probable that mutacins O and N are components of a new member of this special class of bacteriocins (Class IIb, the two peptide bacteriocins) in which the optimal inhibitory activity is dependent on the co-operative activity of the two peptides. Further investigations of strain N examined the expression of mutacins O and N. During a search for a suitable heterologous non-mutacinogenic S. mutans strain to act as an expression host, the genome reference strain, S. mutans UA159 was given consideration. However, contrary to previous reports, this strain was found to exhibit bacteriocin-like inhibitory activity. During a follow-up investigation, strain UA159 was found to inhibit 84 strains representing 11 different species of bacteria, but no inhibition of mutans streptococci was detected. The locus (nlmAB) encoding the two-peptide bacteriocin mutacin IV was identified within the UA159 genome. Using genetic dissection of nlmA and nlmB, the contribution of each peptide was examined and it was found that only the NlmA* propeptide appears to be active, raising doubts as to whether mutacin IV is a bona fide two-peptide bacteriocin. Deletion of the entire nlmAB locus created a mutant strain that exhibited a loss of inhibitory activity against the same 64 strains as was found for the nlmA mutant. A BLASTP search for the consensus leader sequence that precedes the propeptide of Class II bacteriocins, identified ORFs encoding 9 more putative bacteriocin-like peptides. Further genetic dissection identified the SMU.1914c locus as being responsible for the inhibitory activity against a further 15 strains not already sensitive to mutacin IV. SMU.1914c was renamed mutacin V. However, it appears that another as yet unidentified mutacin(s) is also produced by strain UA159 given that three indicator strains still remained sensitive to a double mutant [UA[Delta](1914/NlmAB)] in which both the mutacin IV and putative mutacin V loci were inactivated. Export of Class II bacteriocins has been found to occur by either a SEC-dependent system or via a dedicated peptide ATP Binding Cassette (ABC) transporter. Three potential ABC transporter ORFs were identified in S. mutans UA159. Two (comA and cslA) had the characteristic accessory factor ORF (comB and cslB respectively) located adjacent to the main ABC transporter ORF, while the third ORF763 appeared to lack this. Mutagenesis of each of these five ORFS was carried out and confirmed cslAB to be the ABC transporter involved in the export of the competence stimulating factor, while the function of ORF763 could not be established in this study. Mutagenesis of either comA or comB resulted in a complete cessation of bacteriocin production by the respective mutant strains. Historically, comA and comB is the nomenclature used for loci encoding the exporter of the competence inducing factors in streptococci. In light of this new information, comA and comB were renamed nlmT and nlmE respectively, to account for the newly defined role of this ABC transporter. The present study investigated four bacteriocins two of which (sanguicin K11 and mutacin ON) appear to have some potential for application to anti-caries control, and the others (mutacins IV and V) being shown to be produced by the genome reference strain (UA159). All three mutacins were shown to be exported from their respective producer cells by the NlmTE ABC transporter, while sanguicin K11 is predicted to be exported by a peptide ABC transporter located adjacent to sanK11. Bacteriocins may yet provide a novel alternative for the treatment and control of dental caries. In their favour is that fact that they have relatively narrow defined inhibitory spectra and thus are unlikely to produce widespread changes to plaque ecosystems. Potential uses include as topical agents where bacteriocin preparations could be incorporated into dentrifices such as toothpastes or mouthwashes. Alternatively, streptococci producing anti-mutans streptococcal bacteriocins could be implanted into the oral cavity in strain replacement therapy strategies. There are pros and cons to each technique and the most effective anti-caries control appears more likely to result from "cocktail therapy" where bacteriocins are combined with a number of other anti-mutans streptococcal agents to achieve long-lasting protection against mutans streptococcus proliferation.

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43

James, Peter Alan. "Penicillin tolerance in Streptococcus sanguis". Thesis, University of the West of England, Bristol, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303198.

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Alshammari, Abdulaziz. "IN VITRO EFFECT OF STATINS ON STREPTOCOCCUS MUTANS, STREPTOCOCCUS SANGUIS, AND STREPTOCOCCUS SALVARIUS". Master's thesis, Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/368075.

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Oral Biology
M.S.
Objectives: Cardiovascular disease (CVD), including heart attack, angina, and stroke, is ranked as the number one cause of mortality world wide. High blood cholesterol is linked to CVD and is an important risk factor. Statins – cholesterol lowering drugs- are first choice drugs for reducing the chance of suffering a CVD event. In the USA alone, approximately 32 million individuals take statins. Although randomized control trials of statins have demonstrated their efficacy in preventing CVD, much less information has been reported on their unintended effects. Although not thought of traditionally as antimicrobials, statins have been shown to have antimicrobial effects in vitro. The statins belong to a family of drugs that lower cholesterol levels by inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase, a rate limiting enzyme in the human mevalonate pathway of which cholesterol in the biosynthetic end product. The mevalonate pathway is an important cellular metabolic pathway present in many bacteria. Hence, the aim of this study was to assess the in vitro efficacy of statins against selected strains of oral streptococci, as determined by the minimum inhibitory concentration. A second related objective is to assess the in vitro effect of statins on single species biofilm formation , as determined by binding of the same streptococci to hydroxyapatite pegs. Methods: The effect of statins on S. mutans, S. sanguis, and S. salivarius was determined by finding the minimum inhibitory concentration (MIC) by broth dilution assays. Simvastatin, pravastatin atorvastatin, and rousuvastatin were used in this study. The minimum inhibitory concentration was considered to be the lowest concentration of statin that prevented bacterial growth, i.e. a clear test tube. Experiments were repeated twice for each bacterial species. The effect of simvastatin, atorvastatin, and pravastatin on the ability of S. mutans and S. sanguis to form single species biofilm was assayed using sterile microplates and the MBEC Biofilm Inoculator (Innovatech). Results: Two trials indicated that the MIC of simvastatin against the selected oral bacteria was determined to be 15.6 μg/ml for S. mutans and S. sanguis, and 7.8 μg/ml for S. salivarius. The MIC of rosuvastatin and atorvastatin was determined to be 100 μg/ml against all three streptococci, whereas the MIC of pravastatin was even higher (200 μg/ml) against all three streptococci. Likewise, two trials indicated that statins decreased single species biofilm formation by S. mutans and S. sanguis. For simvastatin, biofilm formation was decreased by concentrations eight fold below the MIC . The results were substantiated by spectrophotometric assay . For atorvastatin and pravastatin, biofilm formation was decreased by concentrations 3-4 fold below the MIC. Conclusions: These experiments demonstrate the in vitro antimicrobial effect of statins on S. mutans, S.sanguis, and S. salivarius. The data indicate that the statins inhibit growth of the test organisms with MIC’s ranging from 7.8-200 μg/ml. Simvastatin has in vitro efficacy against the specific strains of bacteria used in this study at concentrations slightly less than the observed MIC’s of 15.6-7.8 μg/ml . The MIC’s for atorvastatin, pravastatin, and rosuvastatin are much higher than simvastatin, in the range of 100-200 μg/ml . The effects of statins on biofilm parallels the effect on growth of the bacteria.
Temple University--Theses

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45

Ganeshkumar, Nadarajah. "Cell surface of hydrophobic and hydrophilic strains of Streptococcus sanguis". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24669.

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Cell surfaces of aggregation, adherence or hydrophilic variants of Streptococcus sanguis were compared to cell surfaces of the parent strain with regard to their protein and antigenic constituents. Cell surface molecules were released by digestion with mutanolysin. Extraction with SDS-BME, urea, lithium chloride and boiling water did not solubilize any material which stained with silver nitrate in an SDS-polyacrylamide gel. The parent organism S. sanguis 12 which aggregates in saliva, adheres to saliva coated hydroxyapatite (S-HA) and is hydrophobic was found to possess a prominently staining 160,000 MW protein. This protein was almost completely absent from strain I2na, a hydrophobic non-aggregating variant, and was completely absent from the hydrophilic non-aggregating, non-adherent strain 12L. Trypsinization of strain 12 resulted in the coincident loss of the 160,000 MW protein and the ability to aggregate in saliva. Trypsin treatment reduced, but did not eliminate the hydrophobic character of the cells. Boiling destroyed the ability to aggregate but did not alter hydrophobicity. Cell wall digests of strain 12 contained a large number of proteins which were absent from strains 12na and 12L. Mutanolysin digests of the hydrophilic strains contained no material that was visible in a silver stained SDS-polyacrylamide gel. Electron microscopy of phosphotungstic acid stained cells showed a thick capsular material spread evenly over the cell surface of the parent strain 12. This layer was thinner around the cells of strain 12na and appeared patchy on hydrophilic strains. Electron microscopy of uranyl acetate stained cells revealed that strain 12 had short fibrillar structures evenly distributed over the cell surface, and long fibrils which were more concentrated at the end of the cell. The hydrophilic strain 12L lacked both types of fibrils. Crossed immunoelectrophoresis confirmed that the major cell surface antigens were located in the 160,000 MW region. Cell wall digests of strain 12 and 12na inhibited adherence of strain 12 to S-HA by 36% and 19% respectively. The digests of hydrophilic strain 12L were not inhibitory. The inhibitory activity was sensitive to heat and SDS.
Science, Faculty of
Microbiology and Immunology, Department of
Graduate

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46

Ganeshkumar, Nadarajah. "Streptococcus sanguis adhesins mediating attachment to saliva-coated hydroxyapatite beads". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28785.

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Streptococcus sanguis 12 adhesins mediating attachment to saliva-coated hydroxyapatite beads (S-HA) were isolated and characterized. Cell surface fibrils were released from this organism by a method of freeze-thawing followed by brief homogenization. Fibrils in the homogenate were precipitated by ultracentrifugation or ammonium sulphate precipitation. This precipitate was shown to contain fibrils by electron microscopy. Sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis (PAGE) analysis of fibrils showed a single band which stained with Coomassie blue and periodate-Schiff. The molecule had a Mr in excess of 300,000. This protein has been given the name long-fibril protein (LFP). Antibody raised against the LFP reacted with long fibrils of S. sanguis 12. LFP was degraded by subtilisin, pronase, papain, and trypsin, but not by chymotrypsin and muramidases. Fibrils were hydrolyzed by subtilisin into discrete lower Mr protein bands which reacted with both anti-fibril and anti-LFP serum. F(ab')₂ prepared from anti-fibril IgG inhibited adhesion of S. sanguis 12 to pH modified S-HA, indicating that fibrils were acting as an adhesin mediating attachment via the neuraminidase-sensitive receptor on S-HA. Five recombinant clones expressing surface antigens of S. sanguis 12 were isolated by ligating a partial digest of S. sanguis 12 chromosomal DNA with the plasmid vector pUC 18, and transforming into Escherichia coli JM83. Recombinant clones were screened by a colony immunoassay with antisera raised against either S. sanguis 12 whole cells or with anti-fibril serum. Positive clones were then analyzed by SDS-PAGE, Western blotting and restriction endonuclease digestion of recombinant plasmids. One recombinant plasmid, pSA2 expressed two proteins of Mrs of 20,000 and 36,000. The 36,000-Mr protein has been designated as SsaB (S. sanguis adhesin B). Both proteins were purified to homogeneity by gel filtration and ion exchange chromatography. Anti-SsaB serum was used in an immunogold bead labelling experiment to demonstrate that this protein was present on the surfaces of S. sanguis 12 and in the non-saliva-aggregating variant 12na, but not on the non-adhering non-aggregating hydrophilic variant 12L. Western blot analysis with anti-SsaB and anti-20 kd sera showed that both SsaB and the 20 kd proteins were present in cell extracts of S. sanguis 12 and its variants. SsaB inhibited adhesion of S. sanguis 12na to S-HA, indicating that it was the adhesin which mediates the binding to the pH-sensitive receptor. SsaB was found to be present on all S. sanguis strains tested, but not on other oral streptococci. Chemical cross-linking studies of SsaB on S. sanguis 12 cell surface suggested that this protein may be present in a higher Mr complex. This study provides direct evidence that binding of S. sanguis 12 to S-HA involves at least two adhesin-receptor interactions. The adhesin mediating binding to the neuraminidase-sensitive receptor on S-HA involves the long fibrils and the adhesin binding to the acid labile receptor is a 36,000 Mr protein.
Science, Faculty of
Microbiology and Immunology, Department of
Graduate

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47

Floderus, Eugenie. "Aminopeptidases and arginine catabolism in oral straptococci". Stockholm : Kongl. Carolinska Medico Chirurgiska Institutet, 1990. http://books.google.com/books?id=bMZpAAAAMAAJ.

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48

Hengtrakool, Chanothai. "A study of the interactions between glass ionomer cement and Streptococcus sanguis biofilm". Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251917.

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49

Hesketh, L. M. "Characterisation of the adhesive properties of tufted strains of Streptococcus sanguis biotypes I and II". Thesis, University of Manchester, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383198.

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West, Aileen Anne. "A study of extracellular glucosyl- and fructosyltransferase enzyme production by Streptococcus sanguis and related strains". Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316905.

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Tesis sobre el tema "Streptococcus sanguinis"

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