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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Influence of macrophage NF-kappaB activation on pneumococcal pneumonia

Coleman, Fadie Thomas 17 February 2016 (has links)
Streptococcus pneumoniae (pneumococcus) is commonly found in the nasopharynx of healthy individuals, yet it can be a serious pathogen, particularly in the lower respiratory tract, where it can cause severe pneumonia. During pneumococcal pneumonia, anti-bacterial host defense requires the orchestrated expression of innate immunity mediators, initiated by alveolar macrophages and dependent on transcriptional activity driven by Nuclear Factor-𝜅B (NF-𝜅B). Although the initiation of a pulmonary inflammatory response is critical to anti-pneumococcal defense during pneumonia, how differences in pneumococcal-macrophage interactions can influence this process is unclear. To determine the functional significance of varying macrophage NF-𝜅B activation, we examined macrophage responses to pneumococcal stimulation in culture and in mice. Macrophage-pneumococcal interactions resulted in the induction of varied NF-𝜅B activation. Two main pathways were revealed regarding host response and disease outcome. Pneumococci that induced efficient macrophage NF-𝜅B activation resulted in robust anti-pneumococcal lung defense and bacterial clearance. Conversely, failure to activate effective macrophage NF-𝜅B signaling resulted in an altered macrophage response of necroptosis. Overall, we conclude that varying levels of macrophage NF-𝜅B activation by pneumococcus can directly influence the severity of infection. Furthermore, inefficient macrophage NF-𝜅B activation can also have cytotoxic effects on these critical lung resident cells during pneumonia. The induction of macrophage NF-𝜅B activation by S. pneumoniae is as diverse as the population of pneumococcal isolates in the community. A unique host-pathogen interaction exists between pneumococcus and the alveolar macrophage that plays an important role in anti-pneumococcal defense during pneumonia and in the prevention of cytotoxic consequences induced by virulent pneumococci. This interaction suggests that therapies, which modulate NF-𝜅B activation, hold promise for augmenting resistance and ameliorating deleterious effects during pneumococcal pneumonia that could lead to the development of severe disease.
232

Inativação de Streptococcus pneumoniae por terapia fotodinâmica infravermelha com indocianina verde e sua interação com macrófagos RAW 264.7 / Streptococcus pneumoniae inactivation through infrared photodynamic therapy with indocyanine green and its interaction with RAW 264.7 macrophages

Leite, Ilaiáli Souza 17 July 2015 (has links)
As infecções do trato respiratório inferior lideram entre as principais causas de morbidade e mortalidade no mundo. Um dos grandes problemas associados ao tratamento das infecções do sistema respiratório, como as pneumonias, advém da crescente resistência aos mais modernos antibióticos adquirida pelos microrganismos. A terapia fotodinâmica, uma técnica baseada na interação da luz com uma substância fotoativa para causar dano oxidativo a células, tem se destacado como uma interessante alternativa para diversas doenças como diferentes tipos de câncer e infecções. Neste trabalho foi realizada, com experimentos in vitro, uma prova de princípio da possibilidade de inativar, com um protocolo eficiente e seguro, uma das bactérias mais comumente encontradas em quadros de pneumonia, a Streptococcus pneumoniae, com terapia fotodinâmica infravermelha mediada pela indocianina verde. Duas fontes de luz, uma a base de lasers emitindo 780 nm e outra construída com LEDs emitindo 850 nm, foram comparadas para avaliar sua eficiência. Experimentos com a bactéria foram realizados para determinação dos melhores parâmetros de inativação microbiana. Em seguida, ensaios de citotoxicidade foram feitos com macrófagos RAW 264.7 com o intuito de averiguar se as condições microbicidas não apresentavam atividade tóxica para células fagocitárias do sistema imune. Foi possível delinear os parâmetros de concentração de indocianina, tempo de incubação e dose de luz que apresentassem atividade microbicida e que não fossem tóxicas para as células. A interação da terapia fotodinâmica com a ação fagocitária dos macrófagos sobre as bactérias foi avaliada pelo estabelecimento de co-cultura dessas espécies. Concluiu-se que, utilizando-se LEDs de 850 nm fornecendo uma dose de luz de 10 J/cm2 as amostras contendo indocianina verde 5μM, é possível inativar S. pneumoniae de modo eficiente e auxiliar a ação fagocitária de macrófagos. / The lower respiratory tract infections lead among the main causes of morbidity and mortality worldwide. A major problem associated with respiratory tract infections, e.g. pneumonia, stems from from the increasingly resistance to most modern antibiotics developed by microorganisms. Photodynamic therapy, a technique based on the interaction of light and a photoactive substance to cause oxidative damage to cells, has emerged as an attractive alternative for several diseases such as different kinds of cancer and infections. In this work, with in vitro experiments, we accomplished a proof of concept for the possibility of inactivating, with an efficient and secure protocol, one of the most commonly found bacteria in pneumonia cases, Streptococcus pneumoniae, with infrared photodynamic therapy mediated by indocyanine green. Two light sources, one based on 780 nm lasers and the other built with 850 nm LEDs, were compared to evaluate their efficiency. Experiments with bacteria determined the best parameters microbial inactivation. Then, cytotoxicity assays with RAW 264.7 macrophages analyzed if the microbicidal parameters had toxic effects on immune cells. It was possible to delineate the indocyanine concentration parameters, incubation time and dose of light to obtain microbicidal results that weren´t toxic to the cells. Interaction of photodynamic therapy with the phagocytic action of macrophages on the bacteria was assessed by establishing a co-culture with these species. We concluded that, using 850 nm LEDs providing a light dose of 10 J/cm2 to samples containing 5μM indocyanine green, it is possible to inactivate S. pneumoniae and efficiently assist the phagocytic action of macrophages.
233

Applications of droplet-based microfluidics to identify genetic mechanisms behind stress responses in bacterial pathogens

Thibault, Derek M. January 2016 (has links)
Thesis advisor: Michelle Meyer / The primary bacterial targets for most antibiotics are well known. To survive the stress of an antibiotic a bacterium must decrease the antibiotic to target binding ratio to escape from harmful effects. This can occur through a number of different functions including down-regulation of the target, mutation of the binding site on the target, and decreasing the intake or increasing the efflux of the antibiotic. However, it is becoming more evident that an antibiotic stress response influences more than just the primary target, and that a wave of secondary responses can be triggered throughout the bacterium. As a result resistance mutations may arise in genes that are indirectly affected by the initial interaction between the antibiotic and target. These indirect responses have been found to be associated with metabolism, regulation, cell division, oxidative stress, and other critical pathways. One technique recently developed in our lab, called transposon insertion sequencing (Tn-seq), can be used to further understand the complexity of these indirect responses by profiling growth rates (fitness) of mutants at a genome-wide level. However, Tn-seq is normally performed with large libraries of pooled mutants and thus it remains unclear how this may influence fitness of some independent mutants that may be compensated by others in the population. Additionally, since the original method has only utilized planktonic culture, it is also not clear how higher order bacterial structures, such as biofilms or microcolonies, influence bacterial fitness. To better understand the dynamics of pooled versus individual mutant culture, as well as the effect of community structure in microcolony development on the influence of fitness, we adapted a droplet microfluidics-based technique to encapsulate and culture single mutants. We were able to successfully encapsulate at least 7 different species of bacterial pathogens, including Streptococcus pneumoniae, and culture them planktonically, or as microcolonies, in either monodisperse liquid or agarose droplets. These experiments, however, raised an important challenge: the DNA yield from one encapsulation experiment is insufficient to generate samples for sequencing by means of the traditional Tn-seq method. This led us to develop a novel Tn-seq DNA library preparation method, which is able to generate functional Tn-seq library molecules from picogram amounts of DNA. This method is not ideal yet because fitness data generated through the new method currently does not correlate well with data from traditional Tn-seq library preparation. However, we have identified one major culprit that should be easily solvable. We expect by modifying the binding site of the primer used for linear amplification of transposon ends that the new preparation method will be able recapitulate results from the traditional Illumina preparation method for Tn-seq. This will enable us to prepare robust Tn-seq samples from very small amounts of DNA in order to probe stress responses in single mutants as well as in microcolonies in a high-throughput manner. / Thesis (MS) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.
234

Estudo biomolecular de produtos de Chlamydophila pneumoniae, Mycoplasma pneumoniae e Borrelia burgdorferi na etiopatogenia da degeneração mixomatosa da valva mitral / A biomolecular study on Chlamydophila pneumoniae, Mycoplasma pneumoniae and Borrelia burgdorferi products in myxoid mitral valve degeneration etiopathogenesis

Tiveron, Marcos Gradim 11 December 2015 (has links)
Introdução e Objetivo: A doença mixomatosa da valva mitral leva ao comprometimento de sua matriz devido à alteração em sua composição tecidual provocada pelo desequilíbrio na quantidade de ácidos mucopolissacarídeos ou glicosaminoglicanos. Sua etiologia ainda não está totalmente esclarecida, podendo ocorrer em formas familiares com transmissão autossômica dominante de penetrância variável, que pode ser dependente do tempo ou de prováveis fatores ambientais, situações em que a interação de agentes infecciosos necessita de maiores esclarecimentos. O objetivo deste estudo é a análise dos produtos dos patógenos da Chlamydophila pneumoniae, Mycoplasma pneumoniae e Borrelia burgdorferi em segmentos de cúspide retirados da valva mitral com degeneração mixomatosa, comparada ao grupo controle e a relação dos produtos bacterianos com aumento de marcadores inflamatórios (CD20, CD48, CD68) e de metaloproteinase (MMP9) na etiopatogenia da degeneração mixomatosa da valva mitral. Método: Estudo observacional, analítico, tipo caso-controle, que analisou 2 grupos contendo 20 pacientes cada e divididos em grupo 1, composto por fragmentos de tecido valvar mitral com diagnóstico de degeneração mixomatosa extraídos em procedimentos de troca ou plásticas valvares mitrais; e grupo 2, formado por segmentos de valvas mitrais sem valvopatia retirados no serviço de verificação de óbito. Foram realizadas colorações de hematoxilina e eosina e Movat para diagnóstico histológico da degeneração mixomatosa e técnica de imunohistoquímica para detecção de antígenos da Borrelia burgdorferi, Mycoplasma pneumoniae, mediadores inflamatórios (CD20, CD45, CD68) e marcadores de metaloproteinase (MMP9). A presença de antígenos da Chlamydophila pneumonia e foi pesquisada pela técnica de hibridização in situ. A análise quantitativa dos aspectos microscópicos foi realizada com o analisador de imagens Aperio. A pesquisa de elementos bacterianos foi feita através de microscopia eletrônica de transmissão. Resultados: No grupo 1, 14 (70%) pacientes são do gênero masculino e 6 (30%) do gênero feminino. A idade média é de 67,4 anos (51 a 79 anos, dp = 9,2). No grupo 2, 11 (55%) pacientes são do gênero masculino e 9 (45%) do gênero feminino. A idade média é de 67,6 anos (42 a 84 anos, dp= 12,0). Na análise da porcentagem de degeneração mixomatosa pela coloração Movat, houve diferença com significância estatística entre os grupos DM (G1), com média de 54,6 % ± 23,7 e grupo controle (G2) com média de 35,5 % ± 22,5 com valor de p = 0,013. Houve um maior número de células CD20 positivas/mm2 no grupo com DM com mediana igual a 17,8 (6,7 - 27,9) x 4,6 (3,6 - 9,8) com p = 0,007 para a área 1. Houve maior número de células CD45 positivas/mm2 no grupo com DM com mediana igual a 17,3 (3,4 - 92,5) x 2,8 (1,4 - 10,1) com p = 0,008 para a área 1. Houve maior número de células CD68 positivas/mm2 no grupo controle (G2), porém sem significância estatística com mediana igual a 38,7 (26,6 - 81,8) x 70 (42,7 - 120,4) com p = 0,098 para a área 1. Em relação à presença de antígenos de Mycoplasma pneumoniae, houve uma maior área (?m2) de antígenos detectados no grupo 1, quando comparadas com o grupo 2 com diferença estatisticamente significante para as duas áreas. Na área 1, mediana de 180.993 (24.856 - 387.477) x 7.970 (2.736 - 15.992) com p < 0,001 e na área 2, mediana igual a 105.968 (2.503 - 416.585) x 7.190 (3.314 - 17.833) com p = 0,02 A análise da presença de antígenos de Chlamydophila pneumoniae demonstrou que em ambas as áreas, houve uma maior área (?m2) de antígenos detectados no grupo de valvas com degeneração mixomatosa, quando comparadas com o grupo controle, porém sem diferença estatística com mediana para o G1 de 9.905 (4.716 - 16.912) x 5.864 (2.382 - 8.692) com p = 0,2 e para o G2, mediana de 3.199 (1.791 - 10.746) x 2.536 (683 - 6.125) com p = 0,3. Em relação à presença de antígenos de Borrelia burgdorferi, houve uma maior área (um2) de antígenos detectados no grupo 2 em relação ao grupo 1, em ambas as áreas. Na área 1, mediana de 7.596 (3.203 - 13.519) x 10.584 (7.223 - 15.974) com p = 0,14 e na área 2, mediana igual a 5.991 (3.009 - 8.475) x 8.403 (1.626 - 27.887) com p = 0,47. Em relação à presença da metaloproteinase MMP9, observamos maior área (um2) de antígeno marcado de MMP9 no grupo com degeneração mixomatosa tanto na área 1 quanto na área 2, com diferença estatística significante. Na área 1, mediana de 503.894 (202.428 - 938.072) x 269.244 (111.953 - 354.022) com p = 0,03. Na área 2, houve diferença estatística representada pela mediana de 389.844 (214.459 - 679.711) x 144.397 (29.894 - 247.453) com p < 0,001. No grupo DM houve correlação positiva entre Borrelia burgdorferi e porcentagem de DM com R = 0,52 e p = 0,018. Em relação às células inflamatórias, houve correlação positiva entre CD45 e Mycoplasma pneumoniae com R = 0,51 e p = 0,02. A presença de MMP9 se correlacionou positivamente com a presença de Mycoplasma pneumoniae com R = 0,45 e p = 0,04. Estas correlações estiveram ausentes no grupo controle. Conclusões: Houve associação de agentes infecciosos Mycoplasma pneumoniae e Borrelia burgdorferi na etiopatiopatogenia da degeneração mixomatosa da valva mitral. Na análise da relação dos produtos bacterianos com os marcadores inflamatórios e com a metaloproteinase, houve relação positiva entre o marcador inflamatório CD45 e a metaloproteinase (MMP9) apenas com a Mycoplasma pneumoniae, nas valvas com degeneração mixomatosa. O marcador inflamatório CD68 foi encontrado em maior número no grupo controle / Background: The myxomatous mitral valve disease leads to impairment due to changes in their tissue composition caused by the imbalance in the amount of acid mucopolysaccharides or glycosaminoglycans. Its etiology is not yet fully understood and may occur in familial forms of autosomal dominant trait with variable penetrance that can be time-dependent or probable environmental factors, where the interaction of infectious agents requires further elucidation. The purpose of this study is the analysis of the pathogens products of Chlamydophila pneumoniae, Mycoplasma pneumoniae and Borrelia burgdorferi in removed cusp segments of the mitral valve with myxoid degeneration, compared to the control group and the ratio of bacterial products with increased inflammatory markers (CD20, CD48, CD68) and metalloproteinase (MMP9) in the pathogenesis of myxomatous degeneration of the mitral valve. Method: Observational, analytical, case-control study which analyzed 2 groups of 20 patients each and divided in group 1, consisting of fragments of mitral valve tissue with diagnosis of myxomatous degeneration extracted in replacement procedures or mitral valve repair; group 2, formed by segments of mitral valves without valvolpaty clinial disease removed in the coroner service. Hematoxylin and eosin and Movat stains were done for histological diagnosis of myxoid degeneration and immunohistochemical technique for the detection of Borrelia burgdorferi, Mycoplasma pneumonia antigens, inflammatory mediators (CD20, CD45, CD68) and markers of metalloproteinase (MMP9). The presence of Chlamydophila pneumonia antigens was verified through an in situ hybridization technique. The quantitative analysis of the microscopic aspects was performed with the Aperio image analyzer. The research of bacterial elements was performed by a transmission electron microscopy. Results: In group 1, 14 (70%) patients were male and 6 (30%) were female. The mean age was (51 to 79 years, sd = 9.2). In group 2, 11 (55%) patients were male gender and 9 (45%) were female. The mean age was 67,6 years (42 to 84 years, sd= 12). In the analysis percentage of myxomatous tissue by Movat staining, there was a significant difference between the DM (G1) groups, with a media of 54.6 % ± 23,7 and control group (G2) with a media of 35.5 % ± 22.5 with p = 0.013. There was an increased number of CD20 cells/mm2 in myxomatous degeneration group (G1) with a median of 17.8 (6.7 - 27.9) x 4.6 (3.6 - 9.8) with p = 0.007 for the area 1. There was a higher number of CD45 cells/mm2 in myxomatous degeneration group (G1) with a median of 17.3 (3.4 - 92.5) x 2.8 (1.4 - 10.1) with p = 0.008 for the area 1. There was a higher number of CD68 cells/mm2 in control group (G2) without a statistically significant difference, with a median of 38.7 (26.6 - 81.8) x 70 (42.7 - 120.4) with p = 0,098 for the area 1. In quantifying Mycoplasma pneumoniae we observed a higher area (um2) antigen marked by, there was a higher amount of antigen detected in myxomatous degeneration group. In area 1, a median of 180,993 (24,856 - 387,477) x 7,970 (2,736 - 15,992) with p < 0.001 and in area 2, a median of 105,968 (2,503 - 416,585) x 7,190 (3,314 - 17,833) with p = 0.02. The analysis of the presence of Chlamydophila pneumoniae antigens showed that in both area, there was a larger area (?m2) antigens detected in the group of valves with MD when compared with the control group, but without significant differences with median for the G1 of 9,905 (4,716 - 16,912) x 5,864 (2,382 - 8,692), with p = 0.2 and the G2, median 3,199 (1,791 - 10,746) x 2,536 (683 - 6,125) with p = 0.3. Regarding the presence of Borrelia burgdorferi antigens, there was a greater area (?m2) antigens detected in group 2 than in group 1, in both areas. In one area, median 7,596 (3,203 - 13,519) x 10,584 (7,223 - 15,974), with p = 0.14 and in area 2, a median of 5,991 (3,009 - 8,475) x 8,403 (1,626 - 27,887) with p = 0.47. Regarding the presence of metalloproteinase MMP9, we observed a higher area (um2) antigen marked by MMP9 in the group with MD both in area 1and area 2, with statistically significant difference. In area 1, median of 503,894 (202,428 - 938,072) x 269,244 (111,953 - 354,022), p = 0.03. In area 2, median 389,844 (214,459 - 679,711) x 144,397 (29,894 - 247,453) with p < 0.001. In the DM group there was a positive correlation between Borrelia burgdorferi and the percentage of MD with R = 0.52 and p = 0.018. Regarding inflammatory cells, there was a positive correlation between CD45 and Mycoplasma pneumoniae with R = 0.51 and p = 0.02. The presence of MMP9 was positively correlated with the presence of Mycoplasma pneumoniae with R = 0.45 and p = 0.04. These correlations were absent in the control group. Conclusions: There was an association of infectious agents Mycoplasma pneumoniae and Borrelia burgdorferi in etiopathogeny of myxoid degeneration of the mitral valve. In the analysis of the relationship of bacterial products with the inflammatory markers and the metalloproteinase, there was a positive relationship between the inflammatory marker CD45 and metalloproteinase (MMP9) only with Mycoplasma pneumoniae. The inflammatory marker CD68 was found in greater numbers in the control group
235

Imunidade inata na asma fatal / Innate immunity in fatal asthma

Ferreira, Diogenes Seraphim 13 August 2010 (has links)
INTRODUÇÃO: A inflamação das vias aéreas na asma envolve respostas imunes inatas. Os receptores do tipo Toll (Toll-like receptors, TLRs) e a citocina linfopoetina do estroma tímico (thymic stromal lymphopoietin, TSLP) estão envolvidos na inflamação brônquica da asma, mas a expressão destas proteínas em vias aéreas grandes e pequenas de asmáticos ainda não foi investigada. Os objetivos deste estudo foram analisar a expressão protéica de TLR2, TLR3, TLR4 e TSLP em vias aéreas grandes e pequenas de asmáticos, comparar sua expressão entre asmáticos tabagistas e não tabagistas e investigar se a expressão dos TLRs está associada à infecção por Chlamydophila pneumoniae e Mycoplasma pneumoniae. MÉTODOS: Foram analisadas por método imuno-histoquímico e análise de imagens as expressões de TLR2, TLR3, TLR4 e TSLP em vias aéreas grandes e pequenas de 24 indivíduos falecidos por asma (13 não tabagistas e 11 tabagistas) e 9 controles não asmáticos. A análise das proteínas foi realizada em quatro regiões das vias aéreas: camadas epitelial, interna, muscular e externa. A presença de C. pneumoniae e M. pneumoniae no tecido pulmonar foi investigada por meio de reação em cadeia da polimerase em tempo real. RESULTADOS: Os indivíduos asmáticos apresentaram maior expressão de TLR2 nas camadas epitelial e externa de vias aéreas grandes e pequenas, e maior TLR2 na camada muscular de vias aéreas pequenas. Asmáticos tabagistas tiveram menor expressão de TLR2 nas camadas interna e externa de vias aéreas pequenas do que asmáticos não tabagistas. Indivíduos asmáticos tiveram maior expressão de TSLP na camada epitelial e externa de vias aéreas grandes, aumento de TLR3 na camada externa de vias aéreas grandes e aumento de TLR4 na camada externa de vias aéreas pequenas. O DNA de C. pneumoniae e M. pneumoniae não foi detectado em nenhum indivíduo asmático ou controle. CONCLUSÕES: Os receptores da imunidade inata TLR2, 3 e 4 e a citocina TSLP estão aumentados nas vias aéreas de pacientes falecidos por asma, e a expressão dos TLRs não está associada à presença de Chlamydophila pneumoniae e Mycoplasma pneumoniae nos pulmões. O tabagismo em asmáticos parece reduzir a expressão de TLR2 em vias aéreas pequenas. Estes resultados sugerem que os TLRs 2, 3 e 4 e a TSLP podem contribuir com a inflamação brônquica presente em exacerbações graves de asma e que as bactérias C. pneumoniae e M. pneumoniae não estão envolvidas em óbitos por asma / INTRODUCTION: Airway inflammation in asthma involves innate immune responses. Toll-like receptors (TLRs) and the cytokine thymic stromal lymphopoietin (TSLP) are involved in bronchial inflammation in asthma, but the expression of these proteins in large and small airways of asthmatics has not been investigated. The aims of this study were to analyze the protein expression of TLR2, TLR3, TLR4 and TSLP in large and small airways of asthmatics, to compare their expression in smoking and nonsmoking asthmatics and to investigate if TLR expression in associated with infection by Chlamydophila pneumoniae and Mycoplasma pneumoniae. METHODS: Using immunohistochemistry and image analysis, we investigated the expression of TLR2, TLR3, TLR4 and TSLP in large and small airways of 24 fatal asthma patients (13 nonsmokers and 11 smokers) and 9 nonasthmatic controls. The protein expression was analyzed in four regions of the airways: epithelial, internal, airway smooth muscle and outer layers. C. pneumoniae and M. pneumoniae presence in lung tissue was analyzed by real-time polymerase chain reaction. RESULTS: Fatal asthma patients had increased expression of TLR2 in the epithelial and outer layers of large and small airways, and also higher TLR2 in the muscle layer of small airways. Smoking asthmatics had lower TLR2 in the inner and outer layers of small airways than nonsmoking asthmatics. TSLP was increased in the epithelial and outer layers of large airways. Asthmatics also had greater TLR3 in the outer layer of large airways and greater TLR4 in the outer layer of small airways. C. pneumoniae and M. pneumoniae DNA was not detected in asthmatics or controls. CONCLUSIONS: Innate immunity receptors TLR2, 3 and 4 and innate cytokine TSLP are increased in the airways of fatal asthma patients, and TLRs expression is not associated with the presence of Mycoplasma pneumoniae and Chlamydophila pneumoniae in the lungs. Smoking may reduce TLR2 expression in the small airways of asthmatics. These results suggest that TLR2, 3, 4 and TSLP may contribute to the bronchial inflammation seen in severe exacerbations of asthma and that M. pneumoniae and C. pneumoniae are not involved in fatal asthma exacerbations
236

Possível envolvimento da Chlamydia pneumoniae e Mycoplasma pneumoniae na resposta inflamatória da aterosclerose / Possible involvement of Chlamydia pneumoniae and Mycoplasma pneumoniae in the inflammatory response of atherosclerosis

Assis, Renata Melo de 20 June 2008 (has links)
A aterosclerose é um processo complexo, multifatorial que ainda não está totalmente esclarecido. Foi proposto que a resposta imune mediada por processos infecciosos e/ou inflamatórios influencia na patogênese de lesões ateroscleróticas. Os receptores TolI-likes (TLRs) estão envolvidos na resposta inata e em outros eventos fisiológicos através da interação com seus ligantes endógenos e exógenos e talvez envolvidos no processo aterogênico. Tem por objetivo analisar a expressão dos receptores Toll-like 2 e 4 (TLR2 e TLR4) associando o processo de sinalização com a presença de agentes infecciosos tais como a Chlamydia pneumoniae (CP) e Mycoplasma pneumoniae (MP), em pacientes com infarto do miocárdio (MI) e em aneurismas aórticos. Foram obtidos fragmentos de aortas ascendentes de pacientes submetidos à cirurgia de revascularização do miocárdio (G1, n=13) e de fragmentos de pacientes submetidos à cirurgia de correção de aneurisma aórtico (G2, n=14). Amostras congeladas e parafinadas foram analisadas por Imunohistoquímica (lHO) e Hibridização in situ (HIS) para detecção e localização da presença dos patógenos e TLRs. Realizou-se uma semiquantificação em microscópio (O, ausente; 1, discreto e focal; 2, moderado e focal e 3, intenso e difuso). Observou-se o grau de inflamação e de acúmulo de gordura. Outrossim, realizou-se PCR em tempo real (SYBR Green) para pesquisa de DNA de CP e MP, como também análise da expressão de mRNA de TLR2 e de TLR4. Na lHQ, constatou-se presença de MP, CP, TLR2 e TLR4 (G1 e G2), maior quantidade de MP (p=0,012) e de TLR4 (p=0,017) no G2. Houve correlação de CP com MP (r=0,810 e p=0,003) e de TLR2 com TLR4 (r=0,569 e p=0,034). Na HIS, constatou-se presença de MP, CP, TLR2 e TLR4 (G1 e G2), não houve diferenças significativas comparando-se os grupos (G1 x G2), porém houve correlação, no G1, de CP com TLR4 (r=0,730 e p=0,040) e de infiltrado inflamatório com células adiposas (r=0,700 e p=0,036). No G2, houve várias correlações: MP com CP (r=0,620 e p=0,016), MP com TLR4 (r=0,662 e p=0,010), CP com TLR2 (r=O,733 e p=0,003), CP com TLR4 (r=0,589 e p=0,027) e de TLR2 com TLR4 (r=0,714 e p=0,004). A PCR em tempo real mostrou presença de CP, pela segunda extração de DNA realizada (G2). Não houve diferença de expressão dos TLRs entre os grupos. A expressão de TLR2 foi maior do que de TLR4 no G1 (p=0,006). O grau de inflamação e o acúmulo de gordura foram maiores no G2 do que no G1(p=0,001). Estes dados sugerem uma relação da co-infecção CP e MP, na gravidade do processo inflamatório presente em placas ateroscleróticas e em pacientes com infarto do miocádio, como também, participação dos receptores Toll-like 2 e 4. / The atherosclerosis is a complex and multifactorial process that is not still completely elucidated. It has been proposed that immune-mediate response to inflammatory and/or infectious processes is implicated in the pathogenesis of the atherosclerotic lesions. Toll-like receptors (TLRs) are involved in the innate response and other physiological events through binding to endogenous and exogenous ligands and it may be involved in the atherogenic process To investigate the Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) expression in atheroma plaques and its association with the presence of infectious agents such as Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP) in patients with myocardial infarction (MI) and aortic aneurysms. Fragments of ascending aorta were obtained from MI patients submitted to surgeries of revascularization of the myocardium (G1, n=13) and correction of aortic aneurism (G2, n=14). Frozen and paraffined samples slices were analyzed by Immunohistochemistry (lHQ) and in situ Hybridization for detection and localization of TLR2 and TLR4 expression and CP and MP antigens. There was semiquantification in microscope (0, absent; 1, discreet and focal; 2, moderate and focal; and 3, intense and diffuse). Histopathology was also carried out to investigate the inflammation degree and fat accumulation in these tissues. Real time PCR using SYBR Green System detection was used to stydy DNA CP and MP, also to analyze expression of mRNA TLR2 and TLR4. Using lHQ, it was verified presence of MP, CP, TLR2 and TLR4 (G1 and G2), larger amount of MP (p=0.012) and TLR4 (p=0.017) in G2. In G1 group, MP was positively correlated with CP (r=0.810, p=0.003), in G2, TLR2 with TLR4 (r=0.569, p=0.034). Using HIS, it was verified presence of MP, CP, TLR2 and TLR4 (G1 and G2), there were not significant differences between groups (G1 x G2), however, It was shown correlation between in G1, CP with TLR4 (r=0.730, p=0.040) and also inflammation with fat accumulation (r=0.700, p=0.036). In G2, there were several correlations: presence of MP with CP (r=0.620, p=0.016), MP with TLR4 (r=0.662, p=0.010), CP with TLR2 (r=0.733 p=0,003), CP with TLR4 (r=0.589, p=0.027) and TLR2 with TLR4 (r=0.714, p=0.004). Real time PCR showed presence of CP DNA using second purification accomplished (G2). There was not difference of expression TLRs among the groups. The expression of TLR2 was higher than TLR4 in G1 (p=0.006). Increased degree of inflammation and fat accumulation was also find in G2 than in G1 (p=0.001). These results are suggesting that the gravity of the inflammatory process in atherosclerotic plaques strongly are related to the presence of MP and CP co infection and expression of TLR2 and TLR4, as well in MI patients under myocardial revascularization.
237

Microbial degradation of methyl red and its reductive cleavage products.

January 1993 (has links)
by Yuen Pui-yee, Joyce. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 213-221). / Acknowledgments --- p.i / Abstract --- p.ii / List of Tables --- p.ix / List of Figures --- p.xi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Problems of Pollution From Textile Industries --- p.1 / Chapter 1.2 --- Current Treatment Methods of Wastewater from Textile Industries --- p.5 / Chapter 1.3 --- Adverse Effects of Dyes on the Environment --- p.11 / Chapter 1.4 --- Classification of Dyes --- p.16 / Chapter 1.5 --- Azo Dyes --- p.17 / Chapter 1.6 --- Metabolisms of Azo Dyes in Microbial and Animal Systems --- p.21 / Chapter 1.7 --- "Toxicity, Mutagenicity and Carcinogenicity of Azo Dyes" --- p.31 / Chapter 1.8 --- Removal of Azo Dyes --- p.35 / Chapter 1.8.1 --- Biological Methods --- p.35 / Chapter 1.8.2 --- Physico-chemical Methods --- p.49 / Chapter 1.9 --- Purposes of Study --- p.50 / Chapter 2. --- Objectives --- p.53 / Chapter 3. --- Materials and Methods --- p.54 / Chapter 3.1 --- "Isolation, Selection and Characterization of Methyl Red-degrading and N,N-Dimethyl-p-phenylene diamine-degrading Microbial Isolates" --- p.54 / Chapter 3.1.1 --- "Isolation of Methyl Red-degrading Microbial Isolates from Dye- containing Wastewater, Activated Sludge and Soil" --- p.54 / Chapter 3.1.2 --- Selection of Methyl Red-degrading Microbial Isolates --- p.56 / Chapter 3.1.3 --- "Enrichment of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria from Dye-containing wastewater, Activated Sludge and Soil" --- p.59 / Chapter 3.1.4 --- "Isolation of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.60 / Chapter 3.1.5 --- Selection of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria --- p.60 / Chapter 3.1.6 --- "Identification of the Selected Methyl Red-degrading and N,N- Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.61 / Chapter 3.1.7 --- Correlationship of Dry Weight and Absorbance of Cells of Selected Methyl Red-degrading Bacterial Isolates --- p.63 / Chapter 3.2 --- "Characterization of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.64 / Chapter 3.2.1 --- "Chemical Stability of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.64 / Chapter 3.2.2 --- Change of UV-Vis Spectra of Methyl Red and N,N-Dimethyl-p- phenylene diamine at Different pH and Matrixes --- p.64 / Chapter 3.2.3 --- "UV-Vis Spectra and Standard Curves of Methyl Red, N,N- Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.66 / Chapter 3.2.4 --- "HPLC separation of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.67 / Chapter 3.3 --- Methyl Red Degradation by Selected Methyl Red-degrading Microbial Isolates --- p.68 / Chapter 3.3.1 --- "Monitoring of Percentage of Methyl Red Cleaved, Degradation Value of N,N-Dimethyl-p-phenylene diamine and o- Aminobenzoic acid, and Growth of Selected Methyl Red- degrading Bacteria by Spectrophotometric Analysis " --- p.68 / Chapter 3.3.2 --- Study of Degrading Products of Methyl Red by Selected Methyl Red-degrading Isolates --- p.71 / Chapter 3.4 --- Degradation of Other Azo Dyes by Selected Methyl Red-degrading Isolates --- p.73 / Chapter 4. --- Results --- p.74 / Chapter 4.1 --- "Isolation, Selection and Characterization of Methyl Red-degrading and N,N-dimethyl-p-phenylene diamine-degrading Microbial Isolates " --- p.74 / Chapter 4.1.1 --- "Isolation of Methyl Red-degrading Microbial Isolates from Dye- containing Wastewater, Activated Sludge and Soil " --- p.74 / Chapter 4.1.2 --- Selection of Methyl Red-degrading Microbial Isolates --- p.79 / Chapter 4.1.3 --- "Enrichment of N,N-dimethyl-p-phenylene diamine-degrading Bacteria from Dye-containing Wastewater, Activated Sludge and Soil " --- p.85 / Chapter 4.1.4 --- "Isolation of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.85 / Chapter 4.1.5 --- "Selection of N,N-Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.90 / Chapter 4.1.6 --- "Identification of the Selected Methyl Red-degrading and N,N- Dimethyl-p-phenylene diamine-degrading Bacteria " --- p.90 / Chapter 4.1.7 --- Correlationship of Dry Weight and Absorbance of Cells of Selected Methyl Red-degrading Bacterial Isolates --- p.94 / Chapter 4.2 --- "Characterization of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.94 / Chapter 4.2.1 --- "Chemical Stability of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.94 / Chapter 4.2.2 --- "Change of UV-Vis Spectra of Methyl Red and N,N-Dimethyl-p- phenylene diamine at Different pH and Matrixes " --- p.108 / Chapter 4.2.3 --- "UV-Vis Spectra and Standard Curves of Methyl Red, N,N- Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.123 / Chapter 4.2.4 --- "HPLC Separation of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.129 / Chapter 4.3 --- Methyl Red Degradation by Selected Methyl Red-degrading Microbial Isolates --- p.138 / Chapter 4.3.1 --- "Monitoring of Percentage of Methyl Red Cleaved and Degradation Value of N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid and Growth of Selected Methyl Red- degrading Bacterial Isolates by Spectrophotometric Analysis " --- p.138 / Chapter 4.3.2 --- Study of Degradation Products of Methyl Red by Selected Methyl Red-degrading Isolates by HPLC --- p.175 / Chapter 4.4 --- Degradation of Other Azo Dyes by Selected Methyl Red-degrading Isolates --- p.175 / Chapter 5. --- Discussion --- p.181 / Chapter 5.1 --- "Isolation, Selection and Characterization of Methyl Red-degrading and N,N-dimethyl-p-phenylene diamine-degrading Microbial Isolates " --- p.181 / Chapter 5.1.1 --- "Isolation and Selection of Methyl Red-degrading Microbes from Dye-containing Wastewater, Activated Sludge and Soil " --- p.181 / Chapter 5.1.2 --- "Isolation and Selection of N,N-Dimethyl-p-phenylene diamine- degrading Microbial Isolates from Dye-containing Wastewater, Activated Sludge and Soil " --- p.183 / Chapter 5.1.3 --- Identification of the Selected Methyl Red-degrading and N,N- Dimethyl-p-phenylene diamine-degrading Bacteria --- p.185 / Chapter 5.1.4 --- Correlationship of Dry Weight and Absorbance of Cells of Selected Methyl Red-degrading Bacterial Isolates --- p.185 / Chapter 5.2 --- "Characterization of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.186 / Chapter 5.2.1 --- "Chemical Stability of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid in 0.05 M phosphate buffer and 0.2MHC1 " --- p.186 / Chapter 5.2.2 --- "Change of UV-Vis Spectra of Methyl Red and N,N-Dimethyl-p- phenylene diamine at Different pH and Matrixes " --- p.187 / Chapter 5.2.3 --- "Change of UV-Vis Spectra of N,N-Dimethyl-p-phenylene diamine in Different Matrixes at Different pH " --- p.187 / Chapter 5.2.4 --- "UV-Vis Spectra and Standard Curve of Methyl Red, N,N- dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.188 / Chapter 5.2.5 --- "HPLC Separation of Methyl Red, N,N-Dimethyl-p-phenylene diamine and o-Aminobenzoic acid " --- p.189 / Chapter 5.3 --- Methyl Red Degradation by Selected Methyl Red-degrading Microbial Isolates --- p.190 / Chapter 5.3.1 --- Effect of Glucose --- p.194 / Chapter 5.3.2 --- Effect of Ethanol --- p.196 / Chapter 5.3.3 --- Effect of Ammonium Sulphate --- p.198 / Chapter 5.3.4 --- Effect of Yeast Extract --- p.199 / Chapter 5.3.5 --- Effect of Phosphate Buffer (pH 7) --- p.200 / Chapter 5.3.6 --- Effect of pH --- p.201 / Chapter 5.3.7 --- Effect of Temperature at Static and Shaking Conditions --- p.203 / Chapter 5.3.8 --- Study of Degradation Products of Methyl Red by Selected Methyl Red-degrading Isolates by HPLC Analysis --- p.206 / Chapter 5.4 --- Degradation of Other Azo Dyes by Selected Methyl Red-degrading Isolates --- p.207 / Chapter 6. --- Conclusion --- p.209 / Chapter 7. --- References --- p.213 / Chapter 8. --- Appendix 1: Composition of Media --- p.222 / Appendix 2: Composition of Buffers --- p.225 / Appendix 3 --- p.228
238

Résistance aux carbapénèmes médiée par les carbapénèmases de type KPC chez les bacilles à Gram négatif / Carbapenem resistance due to KPC carbapenemases in Gram negative bacilli

Cuzon, Gaëlle 10 October 2011 (has links)
Les carbapénèmes, β-lactamines possédant le spectre d’activité le plus large, sont souvent la dernière option thérapeutique des infections sévères dues à des germes multi-résistants. Les entérobactéries résistantes aux carbapénèmes, bien que rares en France, sont épidémiques voir même endémiques dans de nombreux pays. Cette résistance est principalement due à la production d’enzymes, les carbapénèmases, comme les enzymes de type KPC (Klebsiella pneumoniae Carbapenemase) dont il existe plusieurs variants. Les souches produisant ces enzymes ont rapidement disséminé dans de nombreuses régions du monde. Les objectifs de ce travail étaient de comprendre les mécanismes moléculaires de la multi-résistance aux antibiotiques des souches productrices de KPC et de déterminer lesfacteurs génétiques responsables de leur diffusion. Nous avons montré que le gène blaKPC est associé à un transposon de type Tn3, le transposon Tn4401, dont il existe trois isoformes.Nous avons aussi montré que Tn4401 est un transposon actif, capable de mobiliser le gèneblaKPC, et qui participe également à l’expression de ce gène par apport de séquencespromotrices. Puis, nous avons étudié une collection de souches de Klebsiella pneumoniae et de Pseudomonas aeruginosa exprimant le gène blaKPC. Nous avons ainsi montré que plusieurs clones de K. pneumoniae diffusent actuellement dans différentes régions du monde, avec unclone majoritaire, le clone ST258. Ces clones se caractérisent par des plasmides différents etpar la présence constante de Tn4401. Nous avons montré que plusieurs clones de P.aeruginosa disséminent dans les hôpitaux de Colombie et sont associés à des structuresgénétiques variables encadrant le gène blaKPC. Enfin, nous avons évalué une nouvelle méthode de détection des souches productrices de BLSE et de carbapénèmases, basée sur une puce à ADN. Cet outil s’est révélé rapide, sensible et spécifique pour tous les gènes recherchés. / Carbapenems are β-lactams with the broadest spectrum of activity and are often the last therapeutic option for treating severe infections due to multi-resistant organisms.Carbapenem-resistant Enterobacteriaceae remain rare in France, but are endemic in someareas. Carbapenem-resistance is mainly due to the production of carbapenemases, such as KPC (Klebsiella pneumoniae Carbapenemase). Several variants of KPC enzymes have beenidentified and KPC-producers are increasingly isolated worldwide. The aim of this study wasto determine the molecular mechanisms involved in multi-resistance of KPC-producers and tocharacterize the genetic elements involved in blaKPC gene mobilization and diffusion. Wehave described a new Tn3-based transposon, Tn4401, and characterized three isoforms. We have demonstrated that Tn4401 is an active transposon, capable of mobilizing blaKPC, and isinvolved in blaKPC gene expression. We have analysed several Klebsiella pneumoniae andPseudomonas aeruginosa isolates harboring the blaKPC-2 gene. We have assessed the spread ofseveral clones of K. pneumoniae isolates, including a major clone, ST258. These clones arecharacterized by different plasmids but an identical genetic structure, Tn4401. We havedemonstrated that several clones of P . aeruginosa are disseminating in Colombia, differingby MLST type, genetic support of blaKPC-2 and Tn4401-like structures. Finally, we have evaluated a new commercial system, based on microarray and dedicated to the identification of ESBL- and carbapenemase-producers. We found this method fast, sensitive and specific.
239

The search for allosteric inhibitors

Brear, Paul January 2013 (has links)
This thesis describes the development of chemical tools that inhibit the sialidases NanA and NanB from Streptococcus pneumonia. The primary focus was on the discovery of allosteric inhibitors of NanA and NanB, however, promising inhibitors that act by binding at the active site of these enzymes were also investigated. Chapter 1 gives an overview of the use of chemical tools in the field of chemical biology. It focuses in particular on chemical tools that function by the allosteric regulation of their target proteins. The uses, advantages and methods of discovery of allosteric tools are discussed. Finally this chapter introduces the use of serendipitous binders for the discovery of allosteric sites. In particular, the use of CHES to identify novel allosteric sites on the sialidase NanB is proposed. Chapter 2 describes how the ‘hits' from a series of high throughput screens were reanalysed using a wide range of secondary assays to eliminate any false positives that were contaminating the results. This process removed eight of the eleven ‘hits'. Two of the remaining three compounds were then analysed further in an attempt to characterise their binding mode to NanA and/or NanB using modelling and X-ray crystallographic studies. Whilst, it was not possible to confirm the binding mode by X-ray crystallography modelling studies using the modelling software GOLD generated possible binding modes for these inhibitors. A structure activity relationship study was conducted for both compounds in an attempt to generate more potent inhibitors. Chapter 3 moves from the use of high throughput screens to identify hits against NanA and NanB to the use of the serendipitous binding of N-cyclohexyl-2-aminoethanesulfonic acid in the active site of NanB for the development of selective NanB inhibitors. First taurine was identified as the minimum unit of N-cyclohexyl-2-aminoethanesulfonic acid required to bind to the active site of NanB. Taurine was then used as the basis of an optimisation study. This chapter concludes with the identification of 2-(benzylammonio)ethanesulfonate as the next key intermediate in the development of N-cyclohexyl-2-aminoethanesulfonic acid based active site inhibitors of NanB. Chapter 4 follows on from Chapter 3 with the optimisation of 2-(benzylammonio)ethanesulfonate describing the design and synthesis of a wide range of analogues. From these compounds 2-[(3-chlorobenzyl)ammonio]ethanesulfonate was identified as the most potent and selective inhibitor. Detailed analysis of the binding of 2-[(3-chlorobenzyl)ammonio]ethanesulfonate to NanB gave a rationale for its improved inhibitory activity. The increase in inhibition occurred because on binding of 2-[(3-chlorobenzyl)ammonio]ethanesulfonate to the active site of NanB a well coordinated water molecule was displaced. The displacement of this water caused an increase in the flexibility of the enzyme's 352 loop. A detailed study of the flexibility of this loop in response to various N-cyclohexyl-2-aminoethanesulfonic acid based chemical tools was then conducted. The research in chapters 2 and 3 has recently been published. In Chapter 5 a molecule of N-cyclohexyl-2-aminoethanesulfonic acid that binds serendipitously in a previously unmentioned secondary site is elaborated into a ligand, known as Optactin, that binds strongly and selectively at this secondary site. It was then shown that Optactin inhibited NanB by binding at this secondary site. It was therefore concluded that this secondary site was in fact an allosteric site that could be used for the regulation of NanB. Chapter 6 describes the development of a rationalisation for the inhibition of NanB by Optactin. This study included the X-ray crystallographic analysis of the apo-NanB structure and the NanB-Optactin complex under a range of conditions. This was followed by mechanistic studies that identified the point in the catalytic cycle at which Optactin was inhibiting NanB. This chapter concludes with a hypothesis for the mechanism of inhibition of NanB by Optactin.
240

Sensibilidade a antimicrobianos e sorotipos de Streptococcus pneumoniae isolados de portadores e de indivÃduos com infecÃÃo sistÃmica em Fortaleza, Brasil. / Antibiotic Resistance and Serotypes of Streptococcus pneumoniae Isolated from Carriage and individuals with Sistemic Infection in Fortaleza, Brazil.

Bruno Jaegger Laranjeira 10 February 2010 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O Streptococcus (S.) pneumoniae à considerado como o principal agente causador de morbidade e mortalidade em crianÃas menores de cinco anos de idade. Todas as doenÃas pneumocÃcicas comeÃam com o estabelecimento da colonizaÃÃo do S. pneumoniae na nasofaringe, podendo progredir para doenÃa invasiva se as barreiras naturais forem cruzadas. Nas Ãltimas dÃcadas, o aumento do nÃmero de cepas de S. pneumoniae resistentes à antibiÃticos &#946;-lactÃmicos e a outras classes de antimicrobianos tem dificultado o tratamento da infecÃÃo pneumocÃcica. Atualmente cerca de 13 sorotipos de S. pneumoniae respondem por mais de 85% dos isolados invasivos. A vacina pneumocÃcica polissacarÃdica conjugada 7-valente tem sido amplamente recomendada para crianÃas menores de cinco anos. Os objetivos desse estudo foram determinar a prevalÃncia de S. pneumoniae em crianÃas portadoras, a frequÃncia de isolados de S. pneumoniae de indivÃduos com infecÃÃo sistÃmica, o perfil de sensibilidade a antimicrobianos e os sorotipos mais comuns, em Fortaleza, Brasil. Os isolados de portadores foram recuperados a partir de swabs de nasofaringe de crianÃas usuÃrias de creches, enquanto que os isolados de infecÃÃo sistÃmica foram cedidos pelo LACEN-CE. Foram realizadas as ConcentraÃÃes InibitÃrias MÃnimas (CIM) para penicilina e ceftriaxona para todos os isolados, e levofloxacina apenas para os isolados de nasofaringe. Os pontos de corte das CIM foram determinados de acordo com o CLSI (2007). As sorotipagens dos isolados sistÃmicos foram realizadas pela reaÃÃo de Quellung, enquanto que a genotipagem capsular dos isolados de portadores foi realizada pela tÃcnica de multiplex PCR. De 215 crianÃas usuÃrias de creches, foram isolados S. pneumoniae em 152 (71%). As CIM de 137 isolados de portadores mostraram uma taxa resistÃncia de 71% para penicilina e de 21% para ceftriaxona. NÃo houve resistÃncia nos testes com levofloxacina. Comparado a um estudo similar, realizado hà 10 anos, em Fortaleza, nossos resultados apresentaram um aumento significativo nas taxas de resistÃncia à penicilina e ceftriaxona. De 26 isolados de nasofaringe que apresentaram resistÃncia plena, apenas, seis isolados (23%) tiveram a genotipagem capsular identificada por multiplex PCR. A incidÃncia de isolados invasivos neste estudo por ano, foi de, aproximadamente, 1 caso/100.000 hab. Dos 52 isolados, 42% apresentaram resistÃncia à penicilina e 13,5% à ceftriaxona. Os sorotipos mais comuns dos isolados sistÃmicos foram 19F (12%), 14, 3, 6A (8% cada), 4, 18C e 9V (6% cada), com cobertura estimada, tanto para vacina pneumocÃcica conjugada 7-valente quanto para a 10-valente, de 31,8%. / Streptococcus (S.) pneumoniae is considered the principal causative agent of morbidity and mortality in children younger than five years of age. All pneumococcal diseases are initiated by establishing a S. pneumoniae colonization in nasopharynx, the disease progressing to systemic disease if natural barrier are crossed. During the last decades, the increasing amount of resistant S. pneumoniae strains to beta-lactams and other classes of antimicrobials has modified the treatment of pneumococcal infection. At present, nearly 13 serotypes respond for more than 85% of invasive isolates. The 7-valent polysaccharide-conjugated pneumococcal vaccine has been widely recommended for use in children younger than five years. The aims of this study were to determine the S. pneumoniae carrier in children, the frequence of serotypes from systemic infection patients, the susceptibility profile to antimicrobials in Fortaleza, Brazil. Carrier state isolates were recovered from nasopharyngeal swabs from children attending day-care center facilities, while the isolates from systemic infection fournished by LACEN-CE. Minimal Inhibitory Concentrations (MIC) to penicillin and ceftriaxone were assessed for all isolates, and levofloxacin MIC only from nasopharyngeal isolates. MIC cut-offs were determined according to CLSI standards (2007). Serotyping of systemic isolates was performed by Quellung reaction, while capsular genotyping of carrier isolates was performed by multiplex PCR assay. OF 215 children attending day-care centers, 152 S. pneumoniae isolates were identified (71%). Penicillin MIC showed 71% of resistance, and for ceftriaxone, 21% of resistance. No resistance was found for levofloxacin MIC testing. When compared to a 10-year old similar study in Fortaleza, our results have shown a significant increase of penicillin and ceftriaxone resistance rates. Of 26 isolates tested, only six nasopharyngeal isolates (23%) were positively genotyped by multiplex PCR. The incidence of invasive isolates was 1/100,000 inhab. per year. Of 52 systemic isolates serotyped, 42% were penicillin-resistant, and 13.5% were ceftriaxone-resistant. Systemic serotypes identified were 19F, 3, 6A, 4, 18C and 9V, with a estimated coverage by the 7-valent and 10-v pneumococcal polysaccharide conjugated vaccines of 31.8%.

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