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Garcia, Mendez Karellen Beren. "Infection of human placental cells by Brucella." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT065.
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Les Brucella sont des bactéries intracellulaires responsables de la brucellose, une zoonose mondiale qui cause des avortements chez les animaux, entrainant d'énormes pertes économiques dans les élevages, et des problèmes de santé de longue durée chez l'Homme. Contrairement aux animaux, il existait jusqu’à présent peu de preuves que les infections à Brucella pouvaient causer des complications obstétriques chez la femme. Des récentes études épidémiologiques ont cependant démontré une augmentation significative des risques de complications (fausses couches, mort in utéro, accouchement prématuré) chez les femmes enceintes infectées par Brucella. De plus, il a été montré que plusieurs espèces zoonotiques de Brucella sont capables d’infecter des cytotrophoblastes (CTB) et des trophoblastes extravilleux (EVT) humains, deux types de cellules ayant des fonctions immunitaires et hormonales essentielles pendant le développement du placenta. Dans ce travail, nous avons étudié les conséquences de l’infection des trophoblastes humains par Brucella, du côté du pathogène mais aussi du côté de l’hôte. Nous avons évalué le comportement intracellulaire de différentes souches de Brucella, représentant différentes espèces, hôtes ou symptômes associés. Nous n'avons trouvé aucune corrélation entre la capacité de réplication dans les trophoblastes et l’association des souches avec des complications obstétricales chez leur hôte respectif. Nous nous sommes également intéressé à des souches récemment isolées chez des babouins, après une infection placentaire ayant causé la mort in utéro de leur fœtus. Nous avons montré que ces souches sont capables d’infecter les trophoblastes humains et affectent certaines de leurs propriétés qui sont essentielles lors du développement placentaire. Nous avons également commencé à caractériser des structures intracellulaires atypiques dans lesquelles Brucella semble pouvoir survivre dans certains trophoblastes. Du côté hôte, nous avons analysé le rôle de la protéine eucaryote CD98hc dans l'infection les trophoblastes. Nous avons montré que CD98hc est importante pour l'infection des trophoblastes humains par Brucella, comme cela avait été montré précédemment dans d'autres types cellulaires, et que l’infection modifie le niveau de cette protéine dans les trophoblastes. L'infection des trophoblastes humains par Brucella pourrait donc altérer leurs fonctions au cours du développement placentaire, entraînant ainsi des complications pendant la grossesse.Les résultats obtenus dans ce travail contribuent à une meilleure compréhension des mécanismes pouvant causer des complications obstétricales chez la femme enceinte infectée par brucella et fournissent des informations importantes pour la prise en charge clinique de la brucellose pendant la grossesse<br>Brucella are intracellular bacteria responsible for brucellosis, a worldwide zoonotic disease associated with infectious abortions in animals, which causes huge economical losses in the livestock industry and long lasting health problems in humans. In contrast to animals, evidence of Brucella infections cause obstetric complications in humans is scarce. However, epidemiological studies have shown significant increases in the risk of adverse pregnancy outcomes (miscarriage, stillbirth, preterm delivery) in pregnant women infected with Brucella. Moreover, several zoonotic Brucella species were shown to infect efficiently human cytotrophoblasts (CTB) and extravillous trophoblasts (EVT), two types of cells with essential immune and hormonal functions during placental development. In the present study, we studied the effect of Brucella infection in human trophoblasts, from both the bacterial and the host sides. We evaluated the intracellular behavior of different Brucella strains, representing different species, hosts or associated symptoms. We found no correlation between the bacterial replication rate in trophoblasts and whether the strains were associated with pregnancy complications in their respective host. Importantly, we show that strains isolated from female baboons after stillbirth can infect human trophoblasts and affect some of their properties that are essential during placental development. We also started the characterization of atypical intracellular structures in which Brucella seem to be able to survive in certain types of trophoblasts. From the host side, we analyzed the role of the eukaryotic protein CD98hc in trophoblast infection. We found that CD98hc is important for infection of trophoblasts by Brucella, as shown previously in other cell types, and that infection affects the level of the protein in trophoblasts. Infection of human trophoblasts by Brucella could thus affect their function during placental development, leading to complications in pregnancy.The results obtained in this work contribute to a better understanding of the mechanisms that could lead to obstetric complications in Brucella infected pregnant women and provide important information for the clinical management of brucellosis during pregnancy
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Rossetti, Carlos Alberto. "Host and pathogen transcriptional profiles of acute Brucella melitensis infection." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1636.
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Stoffregen, William Conrad. "Brucella infection and vaccine studies in feral and domestic swine." [Ames, Iowa : Iowa State University], 2006.
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Gagnaire, Aurelie. "Rôle de la voie COX-2 au cours de l'infection par Brucella." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4054.
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Brucella est une bactérie intracellulaire facultative à Gram négatif responsable d’une zoonose, la brucellose. Pour persister dans l’organisme, Brucella agit comme un pathogène furtif en modulant la réponse immunitaire de l’hôte. La cyclooxygénase 2 (COX-2) est l’enzyme responsable de la synthèse des prostanoïdes, des médiateurs lipidiques dérivés de l’acide arachidonique (AA) présentant des propriétés immunorégulatrices. Cette thèse est centrée sur l’étude de cette voie métabolique au cours de l’infection par Brucella in vitro dans des cellules dendritiques (DC) humaines et murines ainsi qu’in vivo chez la souris en comparant différentes routes d’infection. Nous avons mis en évidence la capacité de l’infection à stimuler in vitro la production d’AA ainsi que l’expression de Ptgs2. In vivo, la comparaison des différentes routes d’inoculation a montré que l’infection intradermale induit une signature génique inflammatoire caractérisée par l’expression de Ptgs2 et d’Ifng. L’utilisation de NS-398, un inhibiteur spécifique de COX-2 stimule la clairance bactérienne dans les ganglions cervicaux (CLN) drainant le site d’infection. Ces résultats ouvrent ainsi la voie à de nouvelles stratégies thérapeutiques dans le traitement de la brucellose. La seconde partie de la thèse traite de l’implication des infections bactériennes dans l’initiation des processus oncogéniques. Nous y présentons une revue répertoriant l’ensemble des mécanismes pouvant contribuer à l’initiation oncogénique ainsi qu’un projet que nous développons au laboratoire portant sur l’initiation d’un lymphome folliculaire à la suite d’une stimulation antigénique chronique suite à l’infection par B. abortus<br>Brucella is a facultative intracellular Gram-negative bacterium, responsible for a zoonosis called brucellosis. To persist into the host, Brucella acts as a stealthy pathogen by modulating the host immune response. The cyclooxygenase 2 (COX-2) is the enzyme responsible for the synthesis of prostanoids, a family of lipid mediators derived from the arachidonic acid (AA) and presenting immunomodulatory properties. Here, we have studied the impact of this pathway during Brucella infection in vitro in human and murine dendritic cells (DCs) as well as in vivo by comparing different infection routes. We have highlighted the ability of the infection to stimulate the AA synthesis and Ptgs2 expression. In vivo, by comparing different inoculation routes we showed that intradermal infection induces a specific inflammatory gene signature characterized by an important expression of Ptgs2 and Ifng. The use of NS-398, a specific inhibitor of COX-2 stimulates the bacterial clearance in the cervical lymph nodes (CLN) draining the site of infection. These results might open the way to new therapeutic strategies in the treatment of brucellosis. In a second part of the thesis, we discuss the involvement of bacterial infections in initiating oncogenic processes. Here, we present a review listing all the mechanisms that contribute to the oncogenic initiation and a project that we are developing in the laboratory dealing with the initiation of follicular lymphoma following chronic antigenic stimulation during B. abortus infection
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Kadelka, Mirjam Sarah. "Mathematical models of immune responses following vaccination with application to Brucella infection." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/52967.
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For many years bovine brucellosis was a zoonosis endemic in large parts of the world. While it is still endemic in some parts, such as the Middle East or India, several countries such as Australia and Canada have successfully eradicated brucellosis in cattle by applying vaccines, improving the hygienic standards in cattle breeding, and slaughtering or quarantining infected animals. The large economical impact of bovine brucellosis and its virulence for humans, coming in direct contact to fluid discharges from infected animals, makes the eradication of bovine brucellosis important to achieve. To achieve this goal several vaccines have been developed in the past decades. Today the two most commonly used vaccines are Brucella abortus vaccine strain 19 and strain RB51. Both vaccines have been shown to be effective, but the mechanisms of immune responses following vaccination with either of the vaccines are not understood yet. In this thesis we analyze the immunological data obtained through vaccination with the two strains using mathematical modeling. We first design a measure that allows us to separate the subjects into good and bad responders. Then we investigate differences in the immune responses following vaccination with strain 19 or strain RB51 and boosting with strain RB51. We develop a mathematical model of immune responses that accounts for formation of antagonistic pro and anti-inflammatory and memory cells. We show that different characteristics of pro-inflammatory cell development and activity have an impact on the number of memory cells obtained after vaccination.<br>Master of Science
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Lehman, Christian Ryan. "Characterization of Deoxycholate-Responsive Genes Utilized by Brucella abortus 2308 During Oral Infection." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/86644.
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Brucellosis is a chronic, recurring disease caused by the bacterium Brucella abortus, along with other species of the genus Brucella, and is one of the most common bacterial zoonosis worldwide. The bacteria preferentially infect and reside within host macrophages, causing an undulant fever, joint pain, and other flu-like symptoms, in addition to more severe problems like hepatosplenomegaly and endocarditis. Brucella infection is most often acquired via inhalation through the respiratory route, or via consumption of unpasteurized dairy products. Although ingestion is a major route of infection, the transcriptional response of B. abortus during oral infection remains poorly characterized. In this project, RNA sequencing was used to discover genes with the greatest transcriptional changes in B. abortus subjected to deoxycholate, a host bile acid encountered by bacteria during oral infection. Gene deletion strains of B. abortus were then created and tested for susceptibility to pH and bile acid stress, along with their ability to invade and replicate within macrophages. If the genes of interest are important for the oral infection process, B. abortus strains lacking these genes will likely be more susceptible to pH and deoxycholate stress and may exhibit attenuation in the macrophage infection model. Determination of genes important for the oral infection process would further elucidate the molecular mechanisms by which B. abortus invades the host, and could help lead to future treatments and novel therapeutics.<br>Master of Science
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Xavier, Mariana Noyma. "Mechanisms of Brucella abortus survival during chronic infection during chronic infection: the role of IL-10 and PPARy." Universidade Federal de Minas Gerais, 2013. http://hdl.handle.net/1843/SMOC-9L2QF8.
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Evasion of host immune responses is a prerequisite for chronic bacterial diseases; however, the underlying mechanisms are not fully understood. This study demonstrated that Brucella abortus prevents immune activation of macrophages by inducing CD4+CD25+ T cells to produce interleukin-10 (IL-10) early during infection. Moreover, either a lack of IL-10 production by T cells or a lack of macrophage responsiveness to this cytokine resulted in an increased ability of mice to control B. abortus infection, while inducing elevated production of pro-inflammatory cytokines, and severe pathology in liver and spleen of infected mice. In spite of the significant advances in understanding intracellular survival of B. abortus at the cellular level, little is known about the chronic intracellular niche of B. abortus in vivo. This study demonstrated that B. abortus is able to survive and replicate preferentially in alternatively activated macrophages (AAM), which increase in numbers during chronic infection. The underlying mechanism to this enhanced survival in AAM is a shift in metabolism induced by peroxisome proliferator activated receptor gamma (PPAR), which increases the availability of intracellular glucose. The ability to take up glucose was crucial for increased replication of B. abortus in AAM, and for persistence. Taken together our results suggest that early IL-10 production by CD25+CD4+ T cells modulates macrophage function in order to promote persistent infection. Additionally, B. abortus persistence was also determined by a shift in intracellular nutrient availability induced by PPAR in AAM.<br>A evasão de resposta imune do hospedeiro é um pré-requisito para doenças bacterianas crônicas. No entanto, os mecanismos subjacentes não são totalmente compreendidos. Neste estudo foi demonstrado que a Brucella abortus, impede a ativação dos macrófagos ao induzir a produção de interleucina-10 (IL-10) por células T CD4+CD25+ durante a infecção aguda. Além disso, falha na produção de IL-10 por células T ou a incapacidade de macrófagos em responder a esta citocina resultou num aumento da capacidade de camundongos em controlar a infecção por B. abortus, apesar da indução elevada de citocinas pró-inflamatórias, e de grave patologia no fígado e no baço de camundongos infectados. Apesar dos avanços significativos na compreensão da sobrevivência intracelular de B. abortus in vitro, pouco se sabe sobre o nicho intracelular de B. abortus in vivo. Este estudo demonstra que B. abortus é capaz de sobreviver e replicar preferencialmente em macrófagos alternativamente ativados (AAM), que aumentam em número durante a infecção crônica. O mecanismo desta maior sobrevivência em AAM é uma mudança no metabolismo induzido por peroxisome proliferator activated receptor gamma (PPAR), o que aumenta a disponibilidade de glucose intracelular. A capacidade de transportar glicose foi crucial para persistência, e para aumento da replicação de B. abortus em AAM. Em conjunto, os nossos resultados sugerem que a produção de IL-10 por células T CD4+CD25+ modula a função de macrófagos, a fim de promover infecção persistente por B. abortus. Além disso, tal persistência, também foi determinada por uma mudança na disponibilidade intracellular de nutrientes induzida por PPARy em AAM.
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Vection, Sonia. "Infection of human placental cells by Brucella : Role of the multifunctional host protein CD98hc." Thesis, Université de Montpellier (2022-….), 2022. http://www.theses.fr/2022UMONT010.
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La brucellose, une maladie infectieuse causée par les bactéries du genre Brucella, est une des plus importantes zoonoses mondiales. Maladie animale, l’infection peut être transmise à l’Homme et augmente le risque de complications obstétricales chez la femme enceinte. Durant la grossesse, les cellules placentaires spécialisées appelées trophoblastes occupent les fonctions centrales au sein du placenta. Plusieurs de ces fonctions impliquent la protéine de l’hôte CD98hc. Cette glycoprotéine de surface a été démontrée par notre équipe comme étant importante pour l’infection de différents types cellulaires par Brucella. Dans cette étude, nous souhaitions évaluer l’importance de CD98hc dans l’infection par Brucella dans les trophoblastes humains et avons essayé de déterminer quelle(s) fonction(s) spécifique(s) de CD98hc étai(en)t détournées par la bactérie. Inactiver SLC3A2 (codant pour CD98hc) s’est révélé impossible, montrant le caractère essentiel de ce gène dans les trophoblastes humains. Nous avons cependant obtenu un clone cellulaire qui exprime une protéine avec des changements de conformation et de glycosylation dans son domaine C-ter et qui semble séquestrée dans les endosomes de recyclage. Toutes ces modifications sont cependant compatibles avec l’infection de ces cellules par Brucella, donnant ainsi des pistes sur la façon dont ces bactéries utilisent CD98hc au cours de l’infection. Dans un autre chapitre de ce travail, nous avons identifié le Géfitinib, un inhibiteur de l’EGFR utilisé dans le traitement de maladies non infectieuses, comme médicament prometteur pour lutter contre la brucellose. Le Géfitinib est en effet efficace in vitro contre les 3 principales espèces zoonotiques de Brucella dans les trophoblastes humains et les macrophages murins. Ces résultats fournissent de nouvelles perspectives quant au rôle de CD98hc dans l’infection par Brucella et de nouvelles pistes pour améliorer le traitement de la brucellose<br>Brucellosis, an infectious disease caused by bacteria of the Brucella genus, is one of the major zoonosis around the globe. Initially an animal disease, the infection can be passed onto humans and increases the risk of obstetrical complications in pregnant infected women. During pregnancy, specialized placental cells called trophoblasts ensure the main functions of the placenta. Several of these functions involve the host protein CD98hc. This surface glycoprotein was shown by our group to be important during Brucella infection in different cell types. In this work, we studied the importance of CD98hc in Brucella infection of human trophoblasts and tried to decipher which specific function(s) of the protein was (were) hijacked by the bacteria. Knocking out the SLC3A2 gene (coding for CD98hc) turned out to be impossible, showing that this gene is essential in human trophoblasts. We could however obtain a cellular clone expressing a CD98hc protein with conformational and glycosylation changes in its C-terminal domain and that seems to be trapped in recycling endosomes. Nonetheless, such modifications were compatible with Brucella infection, giving clues about how bacteria could use CD98hc during infection. In another chapter of this work, we identified Gefitinib, an EGFR inhibitor used in the treatment of non-infectious diseases, as a promising drug to fight against brucellosis. This drug was shown to be effective in vitro against the 3 main zoonotic species of Brucella in human trophoblasts as well as murine macrophages. These findings provide new insights into the role of CD98hc in Brucella infection and new leads toward the development of improved brucellosis treatments
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Prasad, Rajeev. "Evaluation of the Aging Immune System Using a Mouse Model of Brucella Infection." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/35820.
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Aging is accompanied by dysregulated immune function resulting in increased susceptibility of the elderly to diseases caused by microbial pathogens. There exists a multitude of data suggesting decreased resistance of the elderly to a variety of intracellular pathogens but there is no data relating the effect of aging on the immune response against Brucella. To elucidate the mechanism of immune dysregulation in old, old and young DBA/2 and BALB/c mice were infected with wild-type B. abortus strain 2308. The old and young mice were also vaccinated with vaccine B. abortus strain RB51 over-expressing Cu-Zn superoxide dismutase (SOD) and then challenged with B. abortus strain 2308 to determine the effect of vaccination in old vs. young mice. Specific IgG1 and IgG2a response to Brucella antigens were also evaluated to determine the effect of aging on Th-specificity of the immune response against Brucella infection. The immune response in aged vs. young mice was further assessed using RT-PCR and cytokine antibody array to determine the type of T-helper response. The experimental results indicate that all mice, regardless of age, survived infection ranging from doses of 2 x 104 to - 2 x 108 CFU. Though the older DBA/2 mice had a higher organism burden after 1 week of infection, these mice cleared Brucella infection more efficiently (5 weeks post-infection) than young mice. Vaccination with strain RB51 over-expressing SOD provided significant protection in young DBA/2, young BALB/c and old BALB/c mice but not in old DBA/2 mice after strain 2308 challenge. The results also suggest that old mice produced a different magnitude of IgG1 and IgG2a response to bacterioferritin and SOD of Brucella. The data suggests that both Th17 as well as Th1 responses were accentuated in old mice as compared to young mice following infection with Brucella. How the Th17 and Th1 branches of immune system work together enabling old mice to clear Brucella better than young mice warrants future investigation.<br>Master of Science
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Papadopoulos, Alexia. "Aanalyse de l' infection des différents sous-types de cellules dendritiques par Brucella abortus." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4032.
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Brucella est une bactérie à Gram négatif, responsable de la brucellose, une zoonose ré-émergente. Sans traitement efficace, la pathologie peut devenir chronique et atteindre une grande variété de cellules et d'organes. Il a été montré que cette capacité à persister dans l'organisme pourrait être facilitée par son aptitude à se répliquer dans les cellules dendritiques (DCs) et à contrôler leur maturation in vitro. Les DCs sont considérées comme les cellules présentatrices d'antigènes les plus efficaces du système immunitaire. Elles forment un réseau complexe de cellules composé de plusieurs populations qui différent par leur origine, leur fonction ou leur localisation. Ainsi l'étude des interactions entre Brucella et les DCs doit être approfondie à ces différents sous-types. Dans ce but, nous avons utilisé différents modèles d'obtention de DCs in vitro précédemment décrits dans la littérature. Ces différentes méthodes de culture nous permettent d'obtenir plusieurs populations de cellules qui partagent des caractéristiques phénotypiques et fonctionnelles avec les sous-types observés in vivo. Nous avons ensuite comparé l'infection par Brucella entre le modèle classique utilisant du GMCSF à des méthodes utilisant du Flt3l ou du GMCSF combiné au Flt3l, à l'IL15 encore à l'IL4. Les résultats obtenus montrent que le contrôle de la maturation des DCs n'est pas un phénomène retrouvé dans toutes les populations. Nous avons pu montrer que dans certaines conditions la réplication de Brucella est moins efficace. Le champ d'étude des interactions entre Brucella et les DCs reste étendu et la compréhension de ces mécanismes pourrait fournir des clés pour combattre cette bactérie<br>Brucella is a facultative intracellular gram-negative bacterium, responsible for a re-emergent zoonosis called brucellosis. Without effective treatment, the pathology may become chronic and reach a wide variety of cells and organs. This ability to persist into the organism has been pointed out as being presumably facilitated by its aptitude to replicate into dendritic cells (DCs) and to control their in vitro maturation. These cells are regarded as the most efficient antigen-presenting cells of the immune system. They form a complex network of cells consisting of several populations differing from each other from their origin, function or location. As a consequence, the interactions between Brucella and DCs should be studied more deeply as regarding the different subset. For that purpose, we used different models of in vitro DCs from former descriptive studies. These various culture methods allow us to get different population sharing phenotypic and functional features with the subtypes examined in vivo. Then, we compared Brucella infection of classical model using GMCSF to methods using Flt3l or GMCSF combined with Flt3l, IL15 or IL4. The results demonstrate that the control of DCs maturation is not a phenomenon that we can find again in every population. Moreover, we showed that the replication of Brucella is less active under certain conditions. The scope of the study on the interactions between Brucella and DCs remains extensive, and the understanding of those mechanisms might open doors in the fight against this bacterium
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MacMillan, Alastair. "The bovine immune response following Brucella vaccination and infection and the development of a discriminatory test." Thesis, University of Surrey, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313252.
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Potemberg, Georges. "Identification des gènes bactériens indispensables lors d’une infection pulmonaire par Brucella dans le modèle expérimental murin." Doctoral thesis, Universite Libre de Bruxelles, 2020. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/304100.
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La brucellose est infection causée par les bactéries du genre Brucella. Cette maladie est répandueà travers le monde entier chez les mammifères et est transmissible aux humains. Causant notammentstérilité, avortement et destruction des articulations, la brucellose représente un risque sanitaire majeur.La chronicité et la récurrence de cette infection provoquent une morbidité importante chez l'hommemalgré des traitements antibiotiques longs et coûteux. Actuellement, les vaccins disponibles ne sont pasconsidérés comme sûrs et efficaces. Le confinement de la maladie repose en partie sur l'identification etl’élimination des troupeaux infectés. La brucellose représente toujours d'énormes pertes économiquespour les pays où la maladie est endémique. Le développement rationnel d'un vaccin atténué efficace etsûr contre les infections à Brucella nécessite l'identification des gènes de virulence indispensables à laréplication in vivo de la bactérie.Dans un modèle d'infection intranasale bien caractérisé chez la souris imitant l'infection naturellepar voie aérienne, nous avons décrit la dynamique de l'infection. En utilisant un marqueur fluorescent,nous sommes en mesure de surveiller la multiplication bactérienne in situ et de déterminer les différentesphases de l'infection. Lors d'une infection intranasale, les macrophages alvéolaires (MA) sont le principaltype cellulaire infecté mais seule une petite proportion de la MA infectée (5 à 15%) est permissive àl'infection. Les bactéries entrant dans la réplication au cours des premières 24 heures sont massivementéliminées, mais cette importante pression sélective peut être partiellement levée par des déficitsimmunitaires génétiques par exemple pour la signalisation de l’IL-17 (réponse immunitaire de type TH17)ou même par une altération de la réponse immunitaire en induisant un phénotype asthmatique (réponseimmunitaire de type TH2).Une identification approfondie de tous les gènes essentiels nécessaires à la croissance sur desmilieux riches ou des gènes conditionnellement nécessaires à la survie lors d'une infection in vitro(macrophages RAW murins) ou in vivo (souris) a été effectuée à différents moments clés précoces du cycleinfectieux en utilisant la technique du séquençage des transposons (Tn-Seq). Sur les 3140 gènes de B.melitensis, 643 sont requis pour la croissance extracellulaire sur des milieux riches. 179 gènessupplémentaires sont indispensables à la survie dans les poumons de la souris jusqu'à 5 jours aprèsl'infection. Seule la moitié de ces gènes peuvent être identifiés à l'aide du modèle in vitro standard,illustrant la limitation d'une telle approche in vitro pour identifier les exigences d'adaptation àl'environnement hôte. L'application de l'analyse en cluster montre que la plupart de ces gènes identifiéspeuvent être recadrés en voies complètes ou impliqués dans des fonctions liées. La synthèse deslipopolysaccharides, la synthèse de certains acides aminés, la B oxydation des acides gras et la cytochromeC oxydase seraient particulièrement importantes face à l'environnement hôte. Nous avons maintenantune idée plus claire des exigences minimales pour que la bactérie infecte avec succès son hôte. Enappliquant cette approche en cas d’immunodéficience pour la signalisation de l’IL-17 ou en conditionasthmatique, nous savons maintenant que l'essentialité de certains gènes peut être levée à savoir lasynthèse du core et de la chaîne O du lipopolysaccharide et la B oxydation des acides gras respectivement.La délétion génétique de certains gènes sélectionnés (10) candidats valide les résultats de nos analysesTn-Seq. Ces analyses comparatives ont le potentiel d'identifier des souches de mutants atténués quipourraient déclencher une immunité protectrice sans la capacité de se propager ou de devenir chroniqueou d'être entièrement virulente même chez des animaux avec une immunité compromise.<br>Doctorat en Sciences<br>info:eu-repo/semantics/nonPublished
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Suraud, Vanessa. "Immunité associée aux amygdales et aux ganglions drainant la conjonctive : effet d'une infection par voie conjonctivale par Brucella melitensis chez le mouton." Tours, 2006. http://www.theses.fr/2006TOUR3312.
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La brucellose chez le mouton est une zoonose bactérienne causée par Brucella melitensis. La voie conjonctivale constitue une voie potentielle d’entrée de ces bactéries et est préconisée comme voie de vaccination contre la brucellose. Cette voie est très efficace, cependant la réponse immunitaire et les mécanismes de recrutement lymphocytaire au sein des amygdales et les ganglions drainant la conjonctive n’ont jamais été explorés. Ce travail montre que l’infection par voie conjonctivale par Brucella melitensis induit une réponse cellulaire surtout dans les ganglions drainants parotidiens et rétropharyngiens médians, associée à une production régulatrice. Principalement les proportions de lymphocytes sont augmentées au cours de l’infection. Les résultats suggèrent également la possible implication des intégrines en réponse à cette infection pour la circulation des lymphocytes dans les structures lymphoïdes<br>Brucellosis in sheep is a bacterial zoonosis caused by Brucella melitensis. The conjunctival route is a potential site of entry for these bacteria and is recommended as a way of vaccination against brucellosis. This way is very efficient. However, the immune response and the mechanisms of lymphocyte recruitment in tonsils and conjunctivae draining lymph nodes have never been explored before. This work shows that conjunctival infection with Brucella melitensis induces a cellular response mainly in parotid and retropharyngeal lymph nodes, associated with a regulatory response. Proportions of lymphocytes were especially increased during the course of infection. Our results also suggest a possible implication for integrins in response to the infection, to allow the circulation of lymphocytes through lymphoïd tissues
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Fosgate, Geoffrey T. "Diagnosis and control of Brucella abortus infection in domestic water buffalo (Bubalus bubalis) of Trinidad, West Indies /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Lavigne, Jean-Philippe. "Lutte contre les infections bactériennes : de l'optimisation de l'administration d'antibiotiques à l'étude d'un modèle de virulence (Brucella suis)." Montpellier 1, 2004. http://www.theses.fr/2004MON1T015.
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POUR LUTTER CONTRE LA PROGRESSION DE LA RESISTANCE BACTERIENNE, DIFFERENTES ACTIONS ONT ETE MENEES AU NIVEAU DE CHAQUE CENTRE HOSPITALIER : DES ETUDES SUR L'ECOLOGIE BACTERIENNE LOCALE OU SUR LA TRANSMISSION DES BACTERIES MULTI-RESISTANTES, DES FORMATIONS RENFORCEES DE PERSONNELS INFIRMIERS. . . PAR AILLEURS, LE MINISTERE ENCOURAGE LES PROGRAMMES DE RECHERCHE BASES SUR LA DECOUVERTE DE NOUVEAUX TRAITEMENTS ANTI-BACTERIENS. CETTE THESE S'INSCRIT DANS CES OBJECTIFS. DANS LE BUT D'UNE MEILLEURE UTILISATION DES ANTIBIOTIQUES, CE TRAVAIL A PERMIS D'OPTIMISER L'ADMINISTRATION DE 2 ANTIBIOTIQUES (CEFTAZIDIME ET SULBACTAM) SUR DES SOUCHES D'ENTEROBACTERIES SECRETRICES DE ß-LACTAMASES A SPECTRE ETENDU. PAR AILLEURS, TROUVER DE NOUVELLES CIBLES NECESSITENT UNE MEILLEURE COMPREHENSION DES STRATEGIES UTILISEES PAR LES BACTERIES POUR PROVOQUER LA MALADIE. L'OBJECTIF N'EST PLUS FORCEMENT DE TUER LA BACTERIE, MAIS PLUTOT DE LA DESARMER. L'ETUDE DES SYSTEMES DE SECRETIONS ET DES PROTEINES EFFECTRICES CONSTITUE UN DES ENJEUX MAJEURS DANS LA COMPREHENSION DE LA VIRULENCE BACTERIENNE. NOUS AVONS UTILISE DANS CE BUT LE MODELE DE VIRULENCE, BRUCELLA SUIS, UN BACILLE A GRAM NEGATIF, QUI SURVIT ET SE MULTIPLIE AU SEIN DES CELLULES INFLAMMATOIRES TELLES QUE LES MACROPHAGES. AU COURS DE NOTRE TRAVAIL, NOUS AVONS MIS AU POINT UNE NOUVELLE STRATEGIE POUR IDENTIFIER LES PROTEINES SECRETEES PAR BRUCELLA DANS LE CYTOPLASME DES CELLULES PHAGOCYTAIRES, BASEE SUR LA SECRETION D'HYBRIDES OBTENUS PAR FUSION DE PROTEINES DE B. SUIS AVEC LA TOXINE YopP DE YERSINIA ENTEROCOLITICA. NOUS AVONS IDENTIFIE UNE NOUVELLE PROTEINE, BvfA (BRUCELLA VIRULENCE FACTOR A), QUI PRESENTE LES PROPRIETES ATTENDUES POUR UN FACTEUR DE VIRULENCE MAJEUR EN RELATION AVEC LE SEUL SYSTEME DE SECRETION CONNU CHEZ BRUCELLA, VirB : I) COMPORTEMENT DE MUTANT KNOCKOUT DE bvfA SIMILAIRE A CELUI DU MUTANT virB DURANT L'INFECTION INTRACELLULAIRE IN VITRO ET IN VIVO, II) CO-REGULATION DE L'EXPRESSION DE bvfA AVEC CELLE DE L'OPERON virB DURANT LA PERIODE D'ACIDIFICATION DU PHAGOSOME. DE PLUS, NOUS AVONS IDENTIFIE UNE NOUVELLE VOIE DE SORTIE DES PROTEINES RECEMMENT DECRITE CHEZ PSEUDOMONAS AERUGINOSA, LE SYSTEME TWIN-ARGININE TRANSLOCATION. DANS L'AVENIR, NOUS POUVONS IMAGINER QUE LE DEVELOPPEMENT DE NOUVELLES MOLECULES ANTIBACTERIENNES AURA POUR BUT DE CIBLER DES SYSTEMES DE SECRETIONS OU DES MOLECULES EFFECTRICES OU D'OPTIMISER L'ADMINISTRATION DES ANTIBIOTIQUES. CES DECOUVERTES AURONT DES RETOMBEES SUR LE TRAITEMENT DE PLUSIEURS BACTERIES PATHOGENES D'IMPORTANCE MAJEURE.
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Hysenaj, Lisiena. "Alterations of hematopoiesis during brucellosis." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0251.
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La brucellose est une maladie qui se transmet de l’animal à l’homme. Elle est causée par la bactérie Brucella. Lors de ma thèse, j’ai montré que Brucella persiste dans les cellules de la moelle osseuse des animaux infectés. Ces observations sont très importantes car la moelle est un organe responsable de la génération des cellules du système immunitaires et c’est la principale niche des cellules souches hématopoïétiques. Au cours de ma thèse, j'ai montré que la protéine de la membrane externe 25 de Brucella (Omp25) est capable de lier au récepteur SLAMF1, une molécule exprimée par les cellules souches hématopoïétiques. Cette interaction conduit à la génération d'un plus grand nombre de cellules myéloïdes par les cellules souches hématopoïétiques. Les cellules myéloïdes sont la niche préférée de Brucella. Ainsi, cette stratégie permet à la bactérie d'envahir l’hôte et d'établir une infection chronique de longue durée. SLAMF 1 apparaît comme une nouvelle cible thérapeutique pour le contrôle des maladies infectieuses chroniques, ce qui représenterait une avancée importante dans la génération de nouveaux médicaments<br>Brucellosis is a disease that is transmitted from animals to humans. It is caused by the pathogenic bacterium Brucella. During my thesis, I showed that Brucella persists in the bone marrow cells of infected animals. These observations are very important because the bone marrow is an organ of the immune system responsible for the generation of the immune cells, as it is the principal niche of hematopoietic stem cells. During my thesis, I showed that Brucella outer membrane 25 (Omp25) is able to bind SLAMF1, a hematopoietic stem cell molecule. This interaction leads to the production of more myeloid cells by the hematopoietic stem cell. Myeloid cells are the favorite niche of Brucella. Thus, this strategy allows the bacteria to invade the host and establish a long lasting chronic infection. SLAMF 1 appears as a new therapeutic target for controlling chronic infectious diseases, which would represent an important advance in the generation of new drugs
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Lee, Mann-Hsi Tso. "Effect of incubation temperature and composition of brucella agar on growth of Campylobacter jejuni." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/53135.
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Aerotolerance of Campylobacter jejuni ATCC 29428 and one of its aerotolerant mutants (strain MC711-01) was measured at 37°C and 42°C. The aerotolerance of C. jejuni was higher at 42°C than at 37°C.
Three different lots of Gibco dehydrated Brucella broth were used to prepare Brucella agar. The agar media were then tested to see if they differed in their ability to support growth of C. jejuni. However, only slight differences in viable counts of C. jejuni were obtained between lots.
Ageing of dehydrated Brucella medium for 2½ months and hydrated Brucella medium for 1½ months greatly affected the growth of C. jejuni and decreased its aerotolerance. This is probably due to the deterioration of the sodium bisulfite in Brucella medium during storage, because addition of 0.01% sodium bisulfite (the same amount as contained in the Brucella medium) to the aged medium (dehydrated or hydrated form) restored the ability of the medium to support growth of C. jejuni under various O₂ levels equivalent to or even better than that obtained with fresh Brucella medium. Moreover, when Brucella agar was prepared from the individual chemical and peptone components, only the medium containing the 0.01% bisulfite yielded colony counts of C. jejuni similar to that obtained on fresh commercial Brucella medium. When sodium bisulfite was omitted, viable counts and aerotolerance were decreased.<br>Master of Science
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Patavino, Claudio <1981>. "Core Genome Multilocus Sequence Typing and Single Nucleotide Polymorphism Analysis in the Epidemiology of Brucella melitensis Infections." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/9076/1/Thesis_PhD_Claudio_Patavino.pdf.
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The use of whole-genome sequencing (WGS) using next-generation sequencing (NGS) technologies has become a widely accepted method for microbiology laboratories in the application of molecular typing, for outbreak tracing and genomic epidemiology. Several studies demonstrated the usefulness of WGS data analysis through single-nucleotide polymorphism (SNP) calling from a reference sequence analysis for Brucella melitensis, whereas gene-by-gene comparison through core-genome multilocus sequence typing (cgMLST) has not been explored so far. The current study developed an allele-based cgMLST method and compared its performance to that of the genome-wide SNP approach and the traditional multilocus variable-number tandem repeat analysis (MLVA) on a defined sample collection. The data set was comprised of 37 epidemiologically linked animal cases of brucellosis as well as 71 isolates with unknown epidemiological status, composed of human and animal samples collected in Italy. The cgMLST scheme generated in this study contained 2,704 targets of the B. melitensis 16M reference genome. We established the potential criteria necessary for inclusion of an isolate into a brucellosis outbreak cluster to be 6 loci in the cgMLST and 7 in WGS SNP analysis. Higher phylogenetic distance resolution was achieved with cgMLST and SNP analysis than with MLVA, particularly for strains belonging to the same lineage, thereby allowing diverse and unrelated genotypes to be identified with greater confidence. The application of a cgMLST scheme to the characterization of B. melitensis strains provided insights into the epidemiology of this pathogen, and it is a candidate to be a benchmark tool for outbreak investigations in human and animal brucellosis.
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Caron, Emmanuelle. "Etude de l'interaction "Brucella"/macrophage humain : implication du TNF alpha (Tumor Necrosis Factor alpha) dans le contrôle de l'infection." Montpellier 2, 1994. http://www.theses.fr/1994MON20273.
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La brucellose atteint l'homme et les animaux d'elevage. Son agent etiologique, brucella, est une bacterie gram-negative a multiplication intramacrophagique. Nous avons developpe un modele experimental d'interaction entre pathogenes intramacrophagiques et macrophage humain, base sur l'utilisation de cellules de la lignee u937, differenciees en macrophages in vitro. Dans ce modele, listeria monocytogenes brucella melitensis, et certains biovars de b. Suis, pathogenes pour l'homme, se multiplient dans les macrophages, alors que l. Ivanovii, pathogene animal, est eliminee. L'opsonisation des brucelles ou l'activation des cellules par le tnf alpha (mais pas l'ifn gamma) reduit la multiplication intracellulaire de b. Suis. Contrairement a l'infection de cellules murines, l'infection des macrophages humains par brucella ne s'accompagne pas de la liberation de tnf alpha. En revanche, les brucelles tuees sont capables d'induire la secretion de tnf alpha. Brucella inhibe la liberation de tnf alpha induite dans les macrophages. Cette propriete repose sur l'existence d'un facteur soluble, libere par brucella lors de son interaction avec le macrophage. Ce facteur, present dans les surnageants de culture de brucella, est capable d'inhiber specifiquement la liberation de tnf alpha par les macrophages humains, mais n'est pas actif sur les macrophages murins. Plusieurs arguments suggerent que ce facteur pourrait constituer un facteur de virulence pour brucella
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Gayet, Soulies Véronique. "Cystite chronique : la brucellose comme étiologie, à propos d'un cas." Bordeaux 2, 1999. http://www.theses.fr/1999BOR2M112.
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Araújo, Kênia Suênia Meira de. "Detecção de anticorpos e pesquisa de DNA de Leptospira spp. e Brucella spp. em bovinos abatidos no Estado do Rio Grande do Norte." Universidade Federal Rural do Semi-Árido, 2012. http://bdtd.ufersa.edu.br:80/tede/handle/tede/350.
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Previous issue date: 2012-08-31<br>This study was aimed at researching anti-Leptospira spp. and anti-Brucella spp. agglutinins in cattle slaughtered in public slaughterhouses in the State of Rio Grande do Norte, as well as confirm the presence of these agents through PCR in the ovaries and epididymides of the slaughtered animals. For such purpose, serum, and ovary or epididymides were collected from cattle at the public slaughterhouses of that state. Sampling was performed during normal slaughter line, without any interference as the order, sex, age, or origin of the slaughtered animals. The screening of animal reagent to leptospirosis was made through the Microscopic Agglutination Test (MAT). To search for brucellosis, animals were screened by the Buffered Acidified Antigen test (BAA) and as a confirmatory test 2-mercaptoethanol (2-ME) was used. To detect bacterial DNA in samples of ovary and epididymides the Polymerase Chain Reaction (PCR) was used. Of all the 306 animals evaluated, 189 (61.76%) were positive for the MAT, where the predominant serovar was Hardjo (24.9%). The second most frequent serovar was Wolffi (14.8%), followed by Butembo, Icterhaemorrragiae, and Hebdomadis who contributed with frequencies ranging from 6.9% to 2.6%. Lower frequencies were found for the serovars Australis (1.6%), Pomona (1.1%), Grippotyphosa (1.1%) and Patoc (1.1%). Canicola, Autumnalis, and Sentot had frequencies lower than 1%. Three animals were positive for the BAA test, however only one of these reacted positively to 2-ME. Not one of the samples was positive for Brucella spp. and Leptopira spp. DNA through the PCR technique. Given the above mentioned data it was concluded that the Leptospira spp. infection in cattle in the semiarid region of Rio Grande do Norte occurs at higher frequency with the serovar Hardjo during the dry season of the year. The Brucella spp. infection is present but has very low frequency, and no DNA from Leptospira spp. and Brucella spp. was detected in the ovary and epididymis samples of the cattle examined<br>Objetivou-se pesquisar aglutininas anti-Leptospira spp. e anti-Brucella spp. em bovinos de abatedouros públicos no Estado do Rio Grande do Norte, bem como confirmar através da PCR, a presença desses agentes nos ovários e epidídimos desses animais. Para isso, foram colhidos durante a linha normal de abate, o sangue e ovário ou epidídimo, de 306 animais no período de dezembro de 2010 a agosto de 2011. Através da Reação de Soroaglutinação Microscópica (SAM) foram detectados 189 (61,76%) animais sororeagente para Leptospira spp., sendo o sorovar Hardjo (24,9%) o mais predominante, seguido do Wolffi, Butembo, Icterhaemorrragiae e Hebdomadis que contribuiram com frequências que variaram de 14,8% a 2,6%. Os sorovares Australis, Pomona, Grippotyphosa, Patoc, Canícola, Autumnalis e Sentot foram menos frequentes. Em análise em separado, o sorovar Hadjo apresentou maior ocorrência no período seco do que no chuvoso (p=0,031). Para a brucelose os animais foram triados através da prova do Antígeno Acidificado Tamponado (AAT) e confirmados pela prova do 2-mercaptoetanol (2-ME). Três animais foram positivos ao AAT, desses apenas um reagiu positivamente ao 2-ME. A PCR foi utilizada para detecção do DNA bacteriano nas amostras de ovário e epidídimo. Nenhuma amostra foi positiva na PCR para detecção de DNA da Brucella spp. e Leptospira spp. Diante do exposto conclui-se que a infecção por Leptospira spp. em bovinos ocorre no semiárido do Rio Grande do Norte com maior frequência para o sorovar Hardjo durante o período seco do ano. A brucelose foi detectada, mas com baixa frequência. Através da PCR não foi detectado DNA de Leptospira spp. e Brucella spp. nos ovários e epidídimos dos animais
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Cellier, Mathieu. "Elaboration de modèles expérimentaux pour l'étude des stress cellulaires dans les interactions hôte - agent pathogène." Montpellier 2, 1992. http://www.theses.fr/1992MON20205.
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Au cours de processus infectieux, les interactions entre pathogenes intracellulaires et macrophages peuvent declencher des reactions cellulaires apparentees a la reponse au choc thermique. Ces reactions impliquant des proteines specifiques appelees proteines de stress (hsp) ont ete etudiees en utilisant comme modele la lignee leucemique humaine u937 et la bacterie brucella. Nous avons montre qu'un choc thermique sub-lethal permet d'induire la differenciation des cellules myelomonocytaires. Les resultats obtenus suggerent une adaptation fonctionnelle au stress des cellules monocytaires permettant d'accelerer leur maturation en macrophages lors d'etats febriles. Les hsp majeure dnak (hsp70) et dnaj (hsp40), groe1 (hsp60) et groes (hsp10) de brucella ovis ont ete clonees. L'operon dnak-j a ete sequence; il est exprime dans e. Coli et permet de complementer un mutant deficient en dnak. La dnak de brucella ovis est d'autre part apparue comme un antigene majeur au cours de l'infection. La caracterisation moleculaire d'un fragment de hsp60 a permis de preciser la taxonomie du genre brucella. La conservation structurale des hsp70 au cours de l'evolution a permis d'analyser l'origine phylogenetique de brucella ovis
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Bosseray, Nicole. "Pathogénie et immunité de l'infection placentaire et foetale de la souris dans le modèle brucellose : comparaison avec les modèles listériose et colibacillose." Tours, 1990. http://www.theses.fr/1990TOUR4002.
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L'infection bactérienne du placenta provoque l'avortement ou la naissance d'un petit infecté congénital. Un modèle souris a été mis au point pour étudier les mécanismes de l'infection foetoplacentaire par trois bactéries qui infectent le placenta humain et des ruminants : brucella, listeria et e. Coli. Ces bactéries inoculées pendant la gestation sont dénombrées par culture de chaque placenta et foetus. L'infection est exprimée en fréquence et intensité. L'aptitude des souches à coloniser les placentas est corrélée avec leur virulence mesurée par d'autres tests sur souris vides. L'inoculation vaginale infecte les placentas par voie descendante. L'inoculation intrapéritonéale ou sous-cutanée plantaire les atteint par voie sanguine, après un relais lymphatique. La colonisation des placentas se fait de manière aléatoire dans la souris. Quelques bactéries se fixent dans chaque placenta et y prolifèrent rapidement. Le placenta peut s'opposer au passage des bactéries vers le foetus. Cet effet barrière diminue avec le temps et l'intensification de l'infection du placenta. La vaccination contre brucella, avant la gestation, par un vaccin vivant, tue, la fraction peptidoglycane ou le lipopolysaccharide, protège placentas et foetus par élévation de l'effet barrière. La protection est transférée par des immunoserums et par les lymphocytes spléniques de type B ou T de donneurs vaccinés. Ni la vaccination, ni le transfert d'immunserum ne protègent les placentas contre listeria ou e. Coli. Des souriceaux infectés naissent à terme de mère infectée par brucella. L'infection congénitale persiste au moins 50 jours.
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Miranda, Flavia Regina. "Pesquisa de anticorpos contra bactérias do gênero Brucella spp, Leptospira spp, Chlamydophila spp em tamanduás-bandeira (Myrmecophaga tridactyla, Linnaeus, 1758), da RPPN SESC Pantanal, Parque Nacional da Serra da Canastra (PNSC) e Parque Nacional das Emas (PNE)." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-24072008-121253/.
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A fragilidade do tamanduá-bandeira (Myrmecophaga tridactyla) e seu visível desaparecimento de certas regiões, inclusa sua área de distribuição original mostram com clareza a necessidade de medidas que possam garantir proteção desse animal. O estudo do papel das doenças nesse aspecto constitui um eixo importante das estratégias para conservação dessa espécie, principalmente considerando-se que estudos ecológicos reconhecem as doenças como o mecanismo regulatório de populações naturais. Este trabalho objetivou avaliar a freqüência de anticorpos anti- Leptospira, anti-Brucella abortus e anti-Chlamidophila. Foram analisadas 21 amostras de soro de tamanduás-bandeira de vida livre oriundos dos Parques Nacionais da Serra da Canastra e das Emas e da Reserva SESC Pantanal. Destes 12 (57,14%) amostras foram reagentes para o teste de soroaglutinação microscópica anti-Leptospira sp, 1 (0,04%) foi reagentes para o teste do Antígeno Acidificado Tamponado (TAA) - anti- Brucella abortus e todas as amostras foram consideradas negativas para a presença de anticorpos anti-Chlamidophila sp. Por se tratar de uma espécie que possui baixo potencial reprodutivo, apresentando cuidado parental prolongado, longos períodos de gestação e somente uma cria por ano, patógenos que possam afetar o sucesso reprodutivo, podem ser extremamente nocivos para populações de tamanduás-bandeira em vida livre.<br>The fragility of the giant Anteater (Myrmecophaga tridactyla) and the disappearance of this animal from certain regions, including areas of original distribution, clearly indicates the necessity of adopting protective measures. Ecology studies consider diseases as regulatory mechanisms for natural populations, thus indicating that the study of the role of diseases constitutes an important axle on the strategies for conservation of the species, few studies correlates the environmental conservation state and the health of wild animal populations. The purpose the present study was to assess the frequency of occurrence of anti-Leptospira, anti-Brucella abortus and anti- Chlamidophila. Serum samples from 21 free-ranging giant anteater from the Serra da Canastra and the Emas National Parks, as well as the SESC Pantanal Reserve were evaluated for the presence of antibodies. From these 12 (57,14%) samples reacted to the anti-Leptospira sp microscopic serum agglutination test ,1 (0.04%) reacted to the anti-Brucella abortus Tampon Acidified Antigen Test (TAA) test, and all samples were negative for anti-Chlamidophila sp antibodies. As the giant anteater is a species that presents low reproductive potential, long parental care and pregnancy periods and produces only one offspring per year, the pathogens that can affect reproduction can be extremely deleterious free-ranging populations of giant anteaters.
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Mathison, Angela Joy. "Macrophage transciptional response to Brucella species : macrophage genes that regulate infection /." 2007. http://www.library.wisc.edu/databases/connect/dissertations.html.
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Canavessi, Aurea Maria Oliveira. "In vitro and in vivo analyses of brucella abortus genes identified in RAW 264.7 macrophage infection using GFP reporter system." 2003. http://www.library.wisc.edu/databases/connect/dissertations.html.
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Etsebeth, Charné. "A serological survey to determine the prevalence of Brucella Canis infection in dogs within the Nelson Mandela Bay metropolitan in the Eastern Cape, South Africa." Diss., 2017. http://hdl.handle.net/10500/23286.
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The prevalence of Brucella canis in South Africa is unknown and suspected to be under-detected. The majority of dogs in South Africa are not tested for Brucella canis, not only because of the level of awareness of Brucella canis in South Africa, but also because of the lack of clinical suspicion. It is not known how the infection entered South Africa.
Brucella canis, a zoonotic organism that causes canine brucellosis in dogs, is a significant cause of reproductive failure in dogs worldwide. Canine brucellosis is a chronic infectious zoonotic disease whose main etiological agent, the Brucella canis bacterium, are rough, intracellular proteobacteria in the Brucellaceae family. Clinical signs in bitches are mainly infertility and abortion, while in males, epididymitis and orchitis occur. However, discospondylitis may develop in both sexes.
A serological survey was conducted to determine the prevalence of Brucella canis infection in dogs from the Nelson Mandela Bay Metropolitan (NMBM) Port Elizabeth (PE) area. A total of 400 samples were collected, 350 of which were collected in seven different townships and 50 were collected in the three different welfare organisations in the study area.
Of the 400 serum samples collected, 39 (9.75%) tested serologically positive by using the Tube Agglutination Test (TAT), the 2-Mercaptoethanol-TAT (2ME-TAT) or the Compliment Fixation Test (CFT). The results of the CFT showed that nine of the 39 positive samples had a maximum antibody titre of 784 IU/ml. The prevalence rate varied tremendously between the samples from the townships and those from the welfare organisations. The prevalence rate of seropositive animals in PE ranged between 5% and 16% in the study area. No positive cases were found in KwaMagxaki and the Animal Welfare Society of PE, but both were surrounded by areas that had positive cases of Brucella canis infection.
The female dogs in the study area had a higher sero-prevalence of only 0.0169 (95% CI, 0.0631 to 0.1489) differences in proportion, and were thus not significant (p > 0.05). However, the female spayed dogs had a much higher significant difference of 0.1898 (95%
iv
CI, 0.1058 to 0.2738) in proportion to the male neutered dogs and were thus statistically significant (p < 0.05). Despite those results, out of all the dogs positive for Brucella canis only two were neutered males and five were spayed females, and the rest were all intact.
In conclusion, according to the results, Brucella canis antibodies were detected in sera of dogs mostly from the townships surveyed. Preventive measures against this contagion should be taken into consideration to eliminate Brucella canis infection from the entire dog population. Reservoir dogs and actively infected dogs either should be kept in quarantine or should be euthanized, because not only can they spread the disease and end the reproductive life of any breeding animal, but they are also a risk to human health.
Even though this is the first survey conducted in the Eastern Cape, the results are still high
dogs in the study area had a higher sero-prevalence of only 0.0169 (95% CI, 0.0631 to 0.1489) differences in proportion, and were thus not significant (p > 0.05). However, the female spayed dogs had a much higher significant difference of 0.1898 (95%
iv
CI, 0.1058 to 0.2738) in proportion to the male neutered dogs and were thus statistically significant (p < 0.05). Despite those results, out of all the dogs positive for Brucella canis only two were neutered males and five were spayed females, and the rest were all intact.
In conclusion, according to the results, Brucella canis antibodies were detected in sera of dogs mostly from the townships surveyed. Preventive measures against this contagion should be taken into consideration to eliminate Brucella canis infection from the entire dog population. Reservoir dogs and actively infected dogs either should be kept in quarantine or should be euthanized, because not only can they spread the disease and end the reproductive life of any breeding animal, but they are also a risk to human health.
Even though this is the first survey conducted in the Eastern Cape, the results are still high<br>College of Agriculture and Environmental Sciences<br>M. Sc. (Agriculture)