Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-06-21T13:42:52Z No. of bitstreams: 2 Tese - Sheila Elke Araújo Nunes - 2014.pdf: 4139252 bytes, checksum: 113368e043fc53148e1cd7b8b50b2632 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-10T13:36:29Z (GMT) No. of bitstreams: 2 Tese - Sheila Elke Araújo Nunes - 2014.pdf: 4139252 bytes, checksum: 113368e043fc53148e1cd7b8b50b2632 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-10T13:36:29Z (GMT). No. of bitstreams: 2 Tese - Sheila Elke Araújo Nunes - 2014.pdf: 4139252 bytes, checksum: 113368e043fc53148e1cd7b8b50b2632 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-12-18 / Introduction: Estimate the costs of treatment of pneumococcal diseases can aid the understanding of reduced economic burden of these after introduction of the pneumococcal conjugate vaccine (PCV), as run in Brazil, in March 2010, which introduced the PCV10 valiant in the National Program Immunization (NPI) for children between 2 and 23 months of age. Cost-effectiveness analysis (CEA) before the introduction indicated that the vaccine was cost-effective (R $ 24.930 / Daly avoided - Disability Adjusted Life Years), in the SUS perspective. Disease burden and the cost of the vaccine were identified as the main drivers of the results for sensitivity analysis. Objectives: Estimate the costs of pneumococcal disease and to evaluate the ratio of incremental cost-effectiveness (ICER) of implementing the PCV-10 brave after introduction into INP Brazil. Methods: Three steps have been performed in the SUS perspective: 1) cost of illness study: medical charts of children 28 days to 35 months of age hospitalized with clinical suspicion of bacterial pneumonia were reviewed to estimate the costs of pneumonia and to other syndromes costs were estimated by therapeutic guidelines; 2) comparison between the three methods of funding: (i) bottom-up / micro-costing by chart review; (ii) top-down / micro-costing through therapeutic guidelines; and (iii) top-down / gross-costing, through reimbursement paid by the SUS. 3) CEA: the strategy to vaccinate with PCV-10 was compared to the non-vaccination. The model used was the PneuModel. In acute otitis media from all causes, pneumococcal meningitis, pneumococcal sepsis and pneumococcal pneumonia were considered. Costs were obtained by microcusteio, epidemiological data from primary studies of population-based, dose costs and vaccination coverage in INP. The discount rate was 5%. Sensitivity analysis was conducted to test the robustness and variability of the model parameters. Results: The cost of study of hospitalized pneumonia records of 52 cases of severe pneumonia and 7 of very serious pneumonia were reviewed. Statistical analyzes of severe pneumonia data revealed that there is difference between the costing methodologies (p=0,015) and to compare the estimated costs by these methods there was no difference between the cost of compensation and the cost for therapeutic guideline (p=0,241). At ACE, annually, vaccination with PCV-10 would prevent 3,942 cases of the disease and 16,514 years of life lost in a cohort of children <1 year. The ICER was R $ 14,230 per DALY averted. In sensitivity analysis, the model was sensitive to variations in incidence and mortality of pneumonia and pneumococcal meningitis. Conclusions: The cost for therapy guideline, uncommonly used in disease cost estimates, was an alternative to funding for compensation, heavily used technique and lower accuracy. After introduction of ICER, using primary data revealed that PCV-10 is a low-cost intervention, as suggested by WHO (<1GDP / per capita - in Brazil, in 2010, US $ 10.933) and, ICER less than previous ACE. Despite uncertainties in critical parameters of the model, using secondary data, ACE can provide evidence to support decision making. After the implementation analysis can result in more accurate estimates and provide evidence to continue vaccination. / Introdução: Estimar os custos do tratamento das doenças pneumocócicas podem auxiliar no conhecimento da redução da carga econômica destas após introdução da vacina anti-pneumocócica conjugada (VPC), como corrido no Brasil, em março de 2010, que introduziu a VPC-10 valente no Programa Nacional de Imunização (PNI), para crianças entre 2 e 23 meses de idade. Análise de custo-efetividade (ACE) antes da introdução indicou que a vacina era custo-efetiva (R$ 24,930/Daly evitado – do inglês, Disability Adjusted Life Years), na perspectiva do SUS. Carga da doença e os custos da vacina foram identificados como os principais direcionadores do resultado para análise de sensibilidade. Objetivos: Estimar os custos da doença pneumocócica e avaliar a razão de custo-efetividade incremental (RCEI) da implementação da VPC-10 valente após introdução no PNI do Brasil. Métodos: Três etapas foram executadas, aplicadas a perspectiva do SUS: 1º) estudo de custo de doenças: prontuários de crianças com 28 dias a 35 meses de idade internadas por suspeita clínica de pneumonia bacteriana foram revisados para estimar os custos da pneumonia e para demais síndromes os custos foram estimados por diretrizes terapêuticas; 2º) comparação entre as três metodologias de custeio: (i) bottom-up/micro-costing através da revisão de prontuários; (ii) top-down/micro-costing através de diretriz terapêutica; e (iii) top-down/gross-costing através de ressarcimento pago pelo SUS. 3º) ACE: a estratégia de vacinar com a VPC-10 foi comparada com a não vacinação. O modelo empregado foi o PneuModel. Neste, otite média aguda por todas as causas, meningite pneumocócica, sepse pneumocócica e pneumonia pneumocócica foram consideradas. Os custos foram obtidos por microcusteio, dados epidemiológicos a partir de estudos primários de base populacional, custos da dose e de cobertura vacinal no PNI. A taxa de desconto aplicada foi de 5%. Análise de sensibilidade foi conduzida para testar a robustez e variabilidade de parâmetros do modelo. Resultados: No estudo de custo da pneumonia hospitalizada prontuários de 52 casos de pneumonias graves e 7 de pneumonias muito graves foram revisados. Análises estatísticas dos dados de pneumonias graves revelaram que há diferença entre as metodologias de custeio (p=0,015) e ao comparar os custos estimados por estas metodologias não houve diferença entre o custeio por ressarcimento e o custeio por diretriz terapêutica (p=0,241). Na ACE, anualmente, a vacinação com VPC-10 evitaria 3.942 casos da doença e 16.514 anos de vida perdidos em uma coorte de crianças <1 ano. A RCEI foi de R$ 14.230 por DALY evitado. Na análise de sensibilidade, o modelo foi sensível às variações de incidência e letalidade de pneumonia e meningite pneumocócica. Conclusões: O custeio por diretriz terapêutica, pouco empregado nas estimativas de custo de doença, se mostrou uma alternativa ao custeio por ressarcimento, técnica muito utilizada e de menor acurácia. A RCEI pós introdução, com dados primários, revelou que a VPC-10 é uma intervenção de baixo custo, como sugerido pela OMS (<1PIB/per capita – no Brasil, em 2010, R$ 10,933) e, com menor RCEI que ACE anterior. Mesmo com incertezas em parâmetros críticos do modelo, usando dados secundários, ACE podem fornecer evidências para apoiar tomadas de decisões. Analise pós-introdução pode resultar em estimativas mais precisas e fornecer evidências para continuar a vacinação.

Streptococcus pneumoniae est un pathogène majeur chez l'homme, responsable d'otites, de pneumonies, de septicémies et de méningites. Récemment des structures de type pilus ont été identifiées à la surface de S. pneumoniae et jouent un rôle important dans les étapes initiales de colonisation des tissus hôtes. Six gènes sont impliqués dans la formation de cette structure. Trois d'entre eux codent pour les protéines structurales ou pilines (RrgA, RrgB et RrgC) et trois autres gènes codent pour les enzymes, appelées sortases, qui catalysent l'association covalente des pilines (SrtC-1, SrtC-2 et SrtC-3). Des modèles de formation du pilus ont été proposés suite à des études de délétion génétique, mais aucune donnée biochimique permettant d'expliquer précisément la formation du pilus au niveau biomoléculaire n'est encore disponible. L'étude individuelle des protéines impliquées dans la formation du pilus a permis la mise en évidence de ponts intramoléculaires Lys-Asn stabilisateurs présents dans chacune des pilines. De plus, la résolution cristallographique de RrgA et RrgB permet de mieux comprendre les propriétés adhésives de cette structure mais également son mécanisme d'assemblage. Comme le rôle de chacune des sortases reste imprécis, nous avons développé un système de co-expression permettant de tester toutes les combinaisons de pilines et de sortases. Celui-ci nous a permis d'identifier les spécificités de chacune des sortases, de générer des complexes covalents piline/piline mais également piline/sortase et ainsi d'obtenir des éléments clés dans la compréhension de la biogenèse de cette structure.

Bacteria secrete and sense extracellular signals from neighboring members of a colony in a phenomenon called quorum sensing. These signals vary from species to species but allow for changes in the behavior of a colony based on changes to cell density, environment, or nutrient supply. Of particular interest to human health is the quorum sensing system of Streptococcus pneumoniae as this pathogen accounts for around one million infection-related deaths per year and is difficult to combat largely due to its ability to form biofilms. These polysaccharide coverings protect entire bacterial colonies from antimicrobial agents as well as allow them to adhere well to the nasopharynx passages of organisms, making them hard to remove. To gain a better understanding of quorum sensing in S. pneumoniae, we propose experiments to study its biofilm formation and its interactions with black carbon, a biochar shown previously to interact with the quorum sensing systems of related bacteria species. We hypothesize that inhalation of black carbon will aggravate a S. pneumoniae infection by promoting biofilm-forming quorum sensing systems making it easier for this bacteria to adhere to and remain on mammal lungs. We propose to first explore the competency and biofilm quorum sensing systems in S. pneumoniae to identify any shared signals between the two using RT-PCR and FITC-Dextran experiments. Further experiments will analyze black carbon particles’ effects on bacterial colonies grown on plates and present on the lung linings of mammals.

S. pneumoniae est un pathogène qui cause plus d'un million de mort par an dans le monde. L'étude de la division bactérienne, processus essentiel à la propagation des bactéries, peut fournir de nouvelles cibles thérapeutiques. DivIB/FtsQ, DivIC/FtsB et FtsL sont trois protéines centrales de la division bactérienne. Nous avons pu démontrer que ces protéines forment un complexe ternaire essentiel à la division du pneumocoque. La protéine DivIB n'est pas essentielle en milieu riche. Son absence entraîne des défauts de séparation des cellules et confirme son rôle dans la division du pneumocoque. Cependant, DivIB est essentielle à la viabilité du pneumocoque en milieu défini. Par ailleurs, nous confirmons que DivIB est nécessaire à la stabilité de FtsL in vivo et suggérons que l'essentialité de DivIB est reliée à la stabilité relative de FtsL. Une étude de la fonctionnalité des domaines a, ß et gamma de la partie extracellulaire de DivIB a révélé que le domaine ß complet est nécessaire pour restaurer le phénotype sauvage de la souche. Enfin, la délétion de divIB accentue la sensibilité du pneumocoque aux antibiotiques de la famille des ß-lactames renforçant l'idée d'un rôle de DivIB dans le métabolisme de la paroi lors de la division. DivIB semble donc être une cible de choix pour rétablir l'efficacité des antibactériens les plus testés et les plus utilisés au monde, les ß-lactames.

Streptococcus pneumoniae[italicized everytime] (S. pneumoniae) causes a spectrum of disease severity, and human host factors likely play a role in this variation. One candidate factor is macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine and upstream regulator of innate immunity. The MIF[italicized when not in parenthesis] promoter contains two functional polymorphisms, a tetranucleotide (CATT) repeat such that MIF expression increases with repeat number from 5-8 and a single nucleotide polymorphism (SNP) leading to a G-to-C transition, which results in increased MIF expression in cell line reporter assays. Emerging data suggest an association between high-expression MIF alleles and inflammatory disease. This study comprised two parts. For the in vitro portion, we hypothesized that peripheral blood monocytic cells (pBMCs) cultured from healthy individuals with low-expressing MIF genotypes (5-CATT alleles or SNP-GG) would have lower MIF content and release than those from individuals with high-expressing MIF genotypes (7-CATT or SNP-C alleles). For the in vivo study, we hypothesized that individuals with low-expressing MIF genotypes would have less severe systemic inflammatory responses than individuals with high-expressing MIF genotypes in response to S. pneumoniae infection. Blood samples and chart findings were collected prospectively at three Connecticut hospitals from 30 inpatients with documented invasive S. pneumoniae infections. Genomic DNA was isolated from host blood, amplified, and genotyped using fragment analysis (CATT repeat) and allelic discrimination (SNP) methods. Fishers exact tests were used to compare genotypes and disease severity. For the in vitro experiments, there were no differences observed in serum MIF levels or MIF content or release from pBMCs based on MIF genotype. In the cohort of patients infected with S. pneumoniae, serum MIF levels among enrolled subjects were significantly higher than the reported normal values, but levels did not vary with genotype or disease severity. The SNP genotype was not correlated with disease severity or occurrence of meningitis. The CATT genotype did not correlate significantly with disease severity or occurrence of meningitis, although there was a trend suggesting an association between the 7-CATT allele and meningitis (p = 0.1188, 8% without meningitis had a 7-CATT allele vs. 40% with meningitis). More patient samples will need to be analyzed in order to definitively elucidate the role of MIF genetics in infection with S. pneumoniae

The aim of this thesis is to characterize metabolic changes in hemocytes during the immune response in D. melanogaster using in vivo markers as well as by measuring gene expression. The impact of the transcription factor HIF1 on the gene expression of glycolytic enzymes and its impact on the systemic metabolism was evaluated. The importance of HIF1 and LDH in the process of fighting against S. pneumoniae infection was tested as well.

La bactérie pathogène, Streptococcus pneumoniae (ou pneumocoque), produit une sérinethréonine-kinase membranaire, StkP, et une tyrosine-kinase, CpsD, qui sont respectivement des régulateurs importants de la division cellulaire et de la synthèse de la capsule polysaccharidique. Ces observations ont été directement la base de mon projet de thèse. Au cours de mon étude, j'ai participé à la mise en évidence du mécanisme par lequel CpsD coordonne la synthèse de la capsule polysaccharidique avec le cycle cellulaire du pneumocoque, en contrôlant via son autophosphorylation la mobilité de la protéine ParB de la ségrégation du chromosome. Pour mieux comprendre le mécanisme moléculaire sous jacent, j'ai caractérisé un nouveau partenaire de CpsD et de ParB appelé RocS. J'ai montré que cette protéine est indispensable pour la ségrégation du chromosome. J'ai ensuite identifié que CpsD et RocS constituent un nouveau mécanisme de protection du nucléoïde, qui était jusque-là inconnu chez le pneumocoque. D'autre part, j'ai contribué à la caractérisation du rôle des sousdomaines PASTA du domaine extracellulaire de StkP dans la régulation de l'épaisseur de la paroi cellulaire septale ainsi que dans le degré d'activation de StkP. Plus particulièrement j'ai mis en évidence que le quatrième sous-domaine PASTA de StkP contrôle la fonction de l'hydrolase de la paroi cellulaire LytB, qui est nécessaire pour les étapes finales de la division cellulaire. Mon travail suggère donc l'existence de réseaux de régulation interconnectés du cycle cellulaire du pneumocoque impliquant ces deux protéine-kinases / The pathogenic bacterium, Streptococcus pneumoniae (the pneumococcus), produces a membrane serine threonine kinase, StkP, and a tyrosine kinase, CpsD, which are important regulators of cell division and polysaccharide capsule synthesis, respectively. These observations were directly at the basis of my thesis project. During my thesis, I participated in the identification of the mechanism by which CpsD coordinates the synthesis of the polysaccharide capsule with the cell cycle of the pneumococcus. Indeed, CpsD autophosphorylation controls the mobility of the chromosome partioning protein ParB protein of the chromosome segregation. To better understand the underlying molecular mechanism, I characterized a new CpsD and ParB partner that we called RocS. I showed that this protein is required for chromosome segregation. I also identified that CpsD and RocS form an atypical nucloied occlusion system, which was previously unknown in pneumococcus. On the other hand, I have contributed to the characterization of the role of the PASTA sub-domains of the StkP extracellular domain in the regulation of the septal cell wall thickness as well as in the degree of activation of StkP. More specifically I showed that the fourth PASTA sub domain of StkP controls the function of the cell wall hydrolase LytB, which is required for the final steps of cell division. My work therefore suggests the existence of interconnected regulation networks of the pneumococcal cell cycle and involving these two protein kinases

La transformation génétique naturelle est un mode de transfert horizontal de gènes chez les bactéries, qui contribue au maintien et à l'évolution de leurs génomes. C’est un mécanisme clé pour l’adaptation des bactéries, qui pourrait être responsable de la transmission des résistances aux antibiotiques observée en clinique chez certaines espèces pathogènes (S. pneumoniae, H. pylori,…). La transformation naturelle s’effectue par l’internalisation d’ADN exogène à travers la membrane, puis par sa prise en charge jusqu’à son intégration dans le chromosome bactérien par recombinaison homologue. Le processus de prise en charge fait intervenir la protéine DprA, très conservée dans le monde bactérien, impliquée dans la protection de l’ADN entrant contre les nucléases, et dans le recrutement de la recombinase universelle RecA sur l’ADNsb. DprA joue donc un rôle majeur et a récemment été décrite comme étant impliquée dans d’autres aspects de la transformation génétique naturelle, comme la fermeture de la compétence via une interaction directe avec le régulateur de réponse ComE, ou la levée de la barrière du système de restriction-modification afin de faciliter la transformation. Chez H. pylori, DprA est en opéron avec DprB, suggérant l’implication de ces 2 protéines dans une même voie et une interaction directe entre elles. DprA apparaît donc comme étant au cœur d’un véritable réseau d’interaction, protéique et nucléique. / The natural genetic transformation is a mode of horizontal gene transfer that contributes to the maintenance and to the evolution of the genomes in bacteria. It is a key mechanism for their adaptation which could be responsible for the transmission of antibiotic resistances observed clinically for some pathogenic species (S. pneumoniae, H. pylori...). Natural transformation is performed by internalizing exogenous DNA followed by its processing and its integration into the bacterial chromosome by homologous recombination. The DNA processing involves the highly conserved DprA protein for the protection of the incoming DNA against nucleases and the recruitment of the universal recombinase RecA on ssDNA. DprA plays a key role and has recently been suggested to be involved in other aspects of the natural genetic transformation, such as the shut-off of the competence via a direct interaction with the response regulator ComE, or removal of the restriction-modification barrier system in order to facilitate the processing. In H. pylori, the dprA gene is in operon with dprB, whose function is unknown, suggesting their involvement in the same pathway and their likely direct interaction. DprA appears to be central in protein/nucleic acid interactions network.

No description available.

La transformation génétique naturelle contribue au maintien et à l'évolution des génomes bactériens, elle constitue pour les bactéries un mécanisme clé pour s'adapter à l'environnement. Elle permet l'intégration d'ADN exogène au sein du chromosome bactérien par recombinaison homologue lors d'un état physiologique particulier de la bactérie appelé compétence. Mon travail de thèse a porté sur la régulation de la compétence chez S. pneumoniae (ComD, ComE) et sur les interactions entre les protéines impliquées dans la prise en charge, le traitement et la recombinaison de l'ADN transformant (DprA, RecA). Chez cette bactérie, l'entrée en compétence est sous le contrôle du système à deux composantes ComD-ComE qui induit la transcription des gènes cibles. DprA est l'une des protéines surexprimée lors de la compétence, elle est très conservée dans le monde bactérien, et participe à la fermeture de la compétence via une interaction directe avec ComE. DprA est également une protéine centrale de la transformation impliquée dans la protection de l'ADN entrant contre les nucléases, et dans le recrutement de la recombinase RecA. L'analyse par SAXS du complexe ComD-ComE, la résolution de la structure cristallographique des domaines REC de ComE, et l'étude des interaction entre ComE et ses régions promotrices ont permis de mieux comprendre la chorégraphie de l'entrée en compétence de S. pneumoniae. En parallèle, nous avons étudié les interactions de SpDprA avec l'ADN et avec RecA. Ces données nous ont permis de proposer un modèle d'interaction entre DprA et RecA chez S. pneumoniae et de proposer un mécanisme de chargement de RecA sur l'ADNsb par DprA. Je me suis également intéressée à DprA de H. pylori en participant à la résolution de la structure 3D de son domaine C-terminal par RMN et en étudiant son interaction avec l'ADNdb. / The natural genetic transformation contributes to the maintenance and the evolution of the genomes in bacteria; it is a key mechanism to adapt to their environment. It allows the integration of exogenous DNA into the bacterial chromosome by homologous recombination during a particular state called competence.My thesis focused on the regulation of the competence state in S. pneumoniae (ComD, ComE), and on the interactions between the proteins involved in the uptake, the processing and recombination of exogenous DNA (DprA, RecA). In this bacterium, the opening of the competence is under the control of the two-component system ComD-ComE, who induces the transcription of target genes. DprA is one of the protein induced during the competence state, it is very conserved into the bacterial kingdom, and is involved in the closure of competence via direct interaction with ComE. DprA is also a key transformation protein involved in processing the incoming DNA, protection against nucleases, and recruitment of the RecA recombinase. SAXS analysis of the ComD-ComE, resolution of the crystallographic structure of ComE REC domain study of the interactions between ComE and its promoter regions allowed us to understand the choreography of competence opening in S. pneumoniae. Meanwhile, we studied spDprA interactions with DNA and with RecA. These data allowed us to propose an interaction model between DprA and RecA in S. pneumoniae and to propose a mechanism for RecA's loading on the ssDNA by DprA. I focused too on H. pylori DprA participating on the resolution of the 3D structure of the C-terminal domain by NMR and studying its interaction with the dsDNA.