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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.
31

A influência da flora intestinal e da esplenectomia na resistência à insulina induzida por obesidade / Influence of gut microbiota and splenectomy over the obesity-induced insulin resistance

Carvalho, Bruno de Melo, 1983- 20 August 2018 (has links)
Orientador: Mário José Abdalla Saad / Tese (doutorado) - Universidade Estadual de Campionas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-20T00:12:29Z (GMT). No. of bitstreams: 1 Carvalho_BrunodeMelo_D.pdf: 4847412 bytes, checksum: e05413650182e8b4049ebd41d6f06e7b (MD5) Previous issue date: 2012 / Resumo: A ingestão de alimentos ricos em gordura leva à obesidade e inflamação crônica sub-clínica, a qual desenvolve papel importante na resistência à insulina. Aumentados níveis circulantes de citocinas pró-inflamatórias, ácidos graxos livres e lipopolissacarídeos ativam o sistema imune inato, que desencadeia inflamação e aumento na expressão de citocinas, levando à resistência à insulina. Dessa forma, nós investigamos o efeito da modulação da flora intestinal, na resistência à insulina e avaliamos o baço como uma nova fonte de inflamação e células do sistema imune, responsáveis pela resistência à insulina induzida por obesidade, cujas funções ainda não estão completamente determinadas. Para investigar os efeitos da modulação da flora intestinal, nós submetemos camundongos a dieta hiperlipídica com antibióticos ou em regime de pair-feeding por oito semanas e realizamos análises metagenômicas de amostras de DNA provenientes das fezes dos camundongos. A fim de avaliar a influência do baço no metabolismo, nós realizamos esplenectomia em camundongos e induzimos obesidade com a utilização de dieta rica em gordura, além de fazer abordagens proteômicas para determinar novas moléculas que poderiam estar envolvidas na inflamação e migração de células. Em ambos os experimentos, glicose, insulina e citocinas circulantes foram avaliadas, assim como as vias de sinalização da insulina e inflamatória em fígado, músculo e tecido adiposo, como também avaliamos a infiltração de macrófagos no fígado e no tecido adiposo. A flora intestinal estava extremamente modificada pelo tratamento com antibióticos, reduzindo a prevalência de Bacteroidetes e Firmicutes, a quantidade de bactérias no intestino e LPS circulante, bem como glicemia, insulinemia e citocinas. Este quadro também apresentou regulação negativa do TLR4 e redução na inflamação, a qual induziu aumento na sensibilidade à insulina, além da notável redução de macrófagos infiltrados nos tecidos dos camundongos tratados com antibióticos. Em camundongos obesos esplenectomizados, houve grande aumento na sensibilidade à insulina, refletida por redução na glicemia, insulinemia e TNF-'alfa' circulante quando comparado com camundongos obesos. A inflamação estava reduzida no fígado, músculo e tecido adiposo dos camundongos obesos esplenectomizados, e como consequência, a via de sinalização de insulina estava mais ativa em comparação aos camundongos obesos que tiveram os baços mantidos. Também houve uma imensa redução na infiltração de macrófagos, no fígado e no tecido adiposo dos camundongos esplenectomizados após a indução de obesidade, quadro semelhante ao encontrado na indução da infiltração de macrófagos pela lipólise. A análise proteômica do baço indicou que GMF-'gama' está mais expresso nos camundongos obesos em relação aos magros, dado confirmado por immunoblot. Concluindo, a modulação da flora intestinal por uma terapia com antibióticos reduziu os níveis circulantes de LPS, inflamação e infiltração de macrófagos, aumentando a sensibilidade à insulina em camundongos alimentados com dieta hiperlipídica. Além disso, a esplenectomia também reduziu a inflamação e promoveu melhora na sensibilidade à insulina, bem como inibiu a infiltração de macrófagos induzida pela obesidade, fenômeno que pode ser coordenado pelo baço e quimiocinas, e possivelmente pelo GMF-'gama', uma nova proteína, que estariam envolvidas na regulação da migração celular e estabelecimento de resistência à insulina / Abstract: A high-fat diet intake induces obesity and chronic subclinical inflammation, which play important roles in insulin resistance. Increased circulating levels of proinflammatory cytokines, free fatty acids and lipopolysaccharides activate innate immune system, which triggers inflammation and cytokine expression, leading to insulin resistance. Thus, we investigated the effect of gut microbiota modulation, on insulin resistance and evaluated the spleen as a novel source of inflammation and immune cells, responsible for the obesity-induced insulin resistance, which roles are not yet fully understood. To investigate microbiota modulation effects, we submitted Swiss mice to a high-fat diet with antibiotics or pair-feeding for eight weeks and performed metagenomic analyses from mice fecal DNA samples. In order to evaluate the spleen influence over the metabolism, we performed splenectomy in Swiss mice and induced obesity with a high-fat diet and performed proteomic approaches to determine novel molecules that could promote inflammation and immune cell migration. In both experiments, blood glucose, serum insulin and cytokines were evaluated, as well as liver, muscle and adipose tissue insulin and inflammatory signaling pathway, and liver and adipose tissue macrophage infiltration. Gut microbiota was greatly modified by the antibiotic treatment, reducing Bacteroidetes and Firmicutes prevalence, overall bacterial count and circulating LPS, as well as fasting blood glucose and serum insulin and cytokines. It also promoted TLR4 downregulation and reduction in inflammation, which promoted improvement in insulin sensitivity, besides a striking reduction in macrophage infiltration in antibiotic-treated mice. In splenectomized obese mice, a great improvement in insulin sensitivity was seen, reflected by blood glucose, serum insulin and TNF-'alpha' levels reduction. Inflammation was reduced in the liver, muscle and adipose tissue of obese splenectomized mice, in consequence, insulin signaling was improved when compared to obese mice that maintained the spleen. There was an immense reduction in liver and adipose tissue macrophage infiltration in splenectomized mice after obesity induction, which was repeated when we observed lipolysis-induced adipose tissue macrophage infiltration. Spleen proteomic studies indicated that GMF-'gamma' is overexpressed in obese mice compared to lean ones. In conclusion, gut microbiota modulation by antibiotic therapy reduced circulating LPS levels, inflammation and macrophage infiltration, improving insulin sensitivity in mice fed a high-fat diet. In addition, splenectomy also reduced inflammation and promoted insulin sensitization, as well as inhibited obesity-induced macrophage infiltration, which can be ruled by the spleen and chemokines, and possibly by GMF-'gamma', a novel protein, that could be involved in the regulation of cell migration and insulin resistance settlement / Doutorado / Fisiopatologia Médica / Doutor em Ciências
32

Impact de traitements antibiotiques sur la flore digestive du porcelet : Etude in vivo et développement d'une approche en système de fermentation in vitro / Impact of antibiotics treatments on piglet gut microbiota : In vivo study and development of an in vitro fermentation system

Fleury, Mickaël 27 February 2015 (has links)
Dans le contexte de l'antibiorésistance, l'objet de ce doctorat vise à évaluer l'impact d'antibiotiques sur le microbiote intestinal de porcelets. La colistine et le ceftiofur, pour lesquels les résistances incluent essentiellement et respectivement mutations chromosomiques et gènes plasmidiques, ont été utilisés. La colistine a significativement réduit la population des entérobactéries, mais aucun E. coli résistant n'a été détecté. L'administration de ceftiofur a eu un impact limité sur les populations bactériennes composant l'écosystème digestif mais a conduit à une forte sélection et à la diffusion d'un gène plasmidique codant pour une bêta-lactamase à spectre étendu. Puis, dans le cadre de la réglementation visant à diminuer l'expérimentation animale, un modèle in vitro colique porcin, nommé PigutIVM, a été mis au point afin de simuler l'environnement digestif du porcelet et a permis de confirmer, in vitro, l'effet observé in vivo de la colistine sur le microbiote. Cet outil a ensuite été utilisé pour évaluer l'impact d'un probiotique, Saccharomyces cerevisiae, comme alternative aux antibiotiques. Le modèle PigutIVM devrait se positionner comme un outil de prédiction pertinent dans les domaines d'investigation aussi bien nutritionnels que pharmacologiques. / In the context of antibiotic resistance, the aim of the current PhD work is to assess the impact of antibiotics on intestinal microbiota of piglets. Two antibiotics i.e. colistin and ceftiofur, for which the main resistances include respectively chromosomal mutations and plasmid genes have been used. Colistin significantly reduced the population of Enterobacteriaceae, but there was no selection of resistant E. coli. The administration of ceftiofur had a limited impact on the bacterial populations that make up the digestive ecosystem but it led to strong selection and dissemination of a plasmid gene encoding an extended-spectrum beta-lactamase. Then, in the framework of regulations to reduce animal testing, an in vitro model of colonic pig named PigutIVM was developed in order to simulate the digestive environment of the piglet and then check the effect of colistin on the microbiota simulated in PigutIVM in vitro. Therefore both the approaches i.e. in vivo and in vitro were compared in order to check the effect of colistin on intestinal microbiota of piglets. This tool was then used to evaluate the impact of a probiotic i.e. Saccharomyces cerevisiae, as alternative to antibiotics. Therefore we assume that this PigutIVM model should be positioned as a relevant predictive tool in the fields of nutritional and pharmacological investigations.
33

Étude du lien entre maladie alcoolique du foie, microbiote intestinal et acides biliaires : rôles spécifiques de la pectine et du récepteur aux acides biliaires TGR5 / Study of the link between alcoholic liver disease, intestinal microbiota and bile acids : key-role of pectin and of the bile acids receptor TGR5

Spatz, Madeleine 15 October 2018 (has links)
La maladie alcoolique du foie (MAF) regroupe l’ensemble des lésions qui apparaissent suite à une consommation excessive et chronique d’alcool. A consommation d’alcool égale, les patients n’évolueront pas tous vers les formes sévères de la maladie. Le microbiote intestinal est un cofacteur déterminant dans la sévérité de la MAF. Parmi les métabolites fécaux entre des souris recevant le microbiote intestinal de patients avec des lésions sévères ou non, les acides biliaires ont été identifiés comme les plus discriminants. Le récepteur aux acides biliaires TGR5, exprimé sur les cellules de Kupffer, favorise leur profil anti-inflammatoire.Nous avons évalué l’impact du récepteur TGR5 dans la MAF chez des souris déficientes pour ce récepteur. La déficience en TGR5 aggrave la MAF, sans passer par une modulation de la cellule de Kupffer. C’est en fait le microbiote intestinal qui est impacté chez les souris déficientes pour TGR5, et qui médie cette aggravation.Par ailleurs, afin de moduler le microbiote intestinal au cours de la MAF, nous avons évalué le rôle de la pectine, qui favorise la croissance de certaines bactéries et peut chélater les acides biliaires. Malgré ses propriétés chélatantes, ce sont bien les modifications du microbiote intestinal induites par la pectine qui jouent un rôle protecteur et curatif dans la MAF.Ces différentes études devraient permettre d’identifier des cibles thérapeutiques potentiellement applicables chez des patients alcooliques et basées sur la modulation du microbiote intestinal. / Alcoholic liver disease (ALD) includes all the liver injuries occurring as a result of excessive and chronic alcohol consumption. Nevertheless, among heavy drinker, only a subset of individuals will develop severe liver injury. Intestinal microbiota was identified as a major player in the mechanisms involved in ALD. Moreover, bile acids were the most discriminant faecal metabolites between mice with or without liver injury. The bile acids receptor TGR5, which is expressed on Kupffer cells, promotes their anti-inflammatory profile.We assessed the role of bile acids receptor TGR5 in ALD using TGR5-deficient mice. TGR5-deficiency worsens ALD, but without modulating the Kupffer cells profile. However, intestinal microbiota is impaired in TGR5-deficient mice, and this is responsible for ALD worsening.Furthermore, in order to modulate the intestinal microbiota during ALD, we assessed the role of pectin, which is known to promote the growth of certain bacteria and that is a bile acids sequestrant. Despite its sequestrant properties, pectin-induced changes in intestinal microbiota play a protective and curative role in ALD.These studies will allow the identification of new therapeutic targets that could be used for alcoholic patients, using intestinal microbiota modulation.
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Mise en place d'un modèle animal d'infection par Blastocystis : répercussion sur la sensibilité colique, le comportement et le microbiote intestinal / Development of an experimental model of Blastocystis infection in rats : Impacts on colonic sensitivity, behavior and the intestinal microbiota composition

Defaye, Manon 07 December 2018 (has links)
Les douleurs abdominales chroniques, souvent associées à une hypersensibilité viscérale d’origine colique (HSVC), sont l’un des symptômes majeurs constatés lors du syndrome de l’intestin irritable (SII). Le SII est une colopathie chronique fonctionnelle touchant environ 11% de la population mondiale et altérant significativement la qualité de vie des patients. L’étiologie multifactorielle de cette pathologie rend la physiopathologie complexe. Les gastroentérites infectieuses ont été décrites comme l’un des facteurs de risque dans le développement du SII-post-infectieux (SII-PI). Le SII-PI survient en effet dans 4 à 31% des cas suite à une gastroentérite aigüe d’origine bactérienne, virale ou parasitaire. Ces infections peuvent avoir de nombreuses répercussions et en particulier sur l’intégrité de la barrière épithéliale intestinale, le système immunitaire ou encore sur le microbiote intestinal. Par ailleurs, suite à une infection parasitaire, le risque de développer un SII est de 40% contre seulement 14% suite à une infection bactérienne.Blastocystis est le parasite intestinal le plus fréquemment retrouvé chez l’Homme. Néanmoins, malgré de récentes études épidémiologiques rapportant une plus forte prévalence de ce parasite chez les patients atteints de SII, son rôle en santé humaine reste débattu. De plus, d’autres études rapportent que les individus porteurs de ce parasite présentent des douleurs abdominales et sont atteints d’une dysbiose intestinale. Actuellement, l’absence d’un modèle animal d’infection par Blastocystis reproductible ne permet pas d’étudier les mécanismes physiopathologiques liés à l’infection et donc d’explorer la contribution éventuelle de ce parasite dans le SII.Les objectifs de ce travail de thèse étaient tout d’abord de mettre en place un modèle murin d’infection expérimentale par Blastocystis pour dans un deuxième temps évaluer si ce parasite est capable d’induire une HSVC et une dysbiose intestinale avec l’objectif d’établir un nouveau modèle de SII d’origine infectieuse chez le rat. Pour répondre au premier objectif, le pouvoir infectieux de différents sous-types et différentes formes du parasite (formes vacuolaires ou kystes), isolés de cultures axéniques ou purifiés à partir de selles de patients et d’animaux a été évalué chez des animaux de laboratoire (rats et souris). Nous avons ainsi réussi à établir un modèle reproductible d’infection chronique par Blastocystis chez le rat de laboratoire à l’aide de kystes purifiés à partir de selles humaines.L’utilisation de ce modèle in vivo, nous a permis de mettre en évidence que le sous-type 4 (ST4) de Blastocystis induit une HSVC sans origine inflammatoire chez les rats expérimentalement infectés. De plus, les animaux développent un comportement type anxio-dépressif corrélé à l’HSVC. La dysbiose intestinale associée à l’infection se caractérise par une augmentation de la richesse bactérienne et une diminution du ratio Firmicutes/Bacteroidetes. Par ailleurs, nous avons corrélé l’HSVC à l’augmentation de l’abondance relative du genre Bacteroides et la diminution de l’abondance relative de la famille des Clostridiaceae, bactéries productrices d’acides gras à chaine courte (AGCC). Une diminution des taux d’AGCC fécaux a d’ailleurs été constatée chez les rats infectés. De plus, nous avons mis en évidence une augmentation de l’activité de protéases à sérine dans les fèces des animaux infectés pouvant expliquer l’HSVC.Ces données suggèrent qu’une infection gastro-intestinale par Blastocystis serait associée à une hypersensibilité viscérale d’origine colique (HSVC) et à un déséquilibre de la flore intestinale (dysbiose). Ainsi, ce nouveau modèle d’infection pourrait être un bon modèle de SII d’origine infectieuse et pourrait donc contribuer à un meilleur diagnostic et au développement de nouvelles stratégies thérapeutiques pour des pathologies chroniques de l’intestin chez certains individus. / Chronic abdominal pain often associated with colonic hypersensitivity (CHS) is one of the major symptoms of irritable bowel syndrome (IBS). IBS is a functional chronic disorder affecting ~11% of worldwide population and disturbing patients’ quality of life. Etiology is multifactorial and thus pathophysiology is complex and remains poorly understood. Infectious gastroenteritis has been described as one of the risk factors for development of post-infectious IBS (PI-IBS). PI-IBS can occur in 4-31% of patients following acute gastroenteritis of bacterial, viral or parasitic origin. Numerous studies support a role for pathogen-mediated modifications in the resident intestinal microbiota, epithelial barrier integrity and immune activation in PI-IBS. Interestingly, the risk of IBS is highest with protozoal enteritis, with ~40% of individuals developing IBS against ~14% following bacterial infection. Blastocystis is the most common intestinal parasite found in human intestinal tract. Nevertheless, clinical relevance remains controversial, despite recent epidemiological studies showing a higher prevalence of this parasite in IBS patients. Interestingly, studies report that individuals carrying Blastocystis display abdominal pain and intestinal dysbiosis. Currently, the lack of reproducible animal model of Blastocystis infection does not allow to study the pathological mechanisms related to infection and thus to explore the potential contribution of this parasite in IBS.The aims of this study were first to develop a murine model of Blastocystis infection and then to investigate whether this parasite could lead to the development of intestinal dysbiosis associated CHS with the aim of developing a new PI-IBS rat model.The first aim was to evaluate the infectivity of different parasitic subtypes and stages (vacuolar and cystic forms) isolated from axenic cultures or purified from human or animal feces, into laboratory animals (rats and mice). Interestingly, we succeeded in the development of a reproducible model of chronic infection by Blastocystis in laboratory rats using cysts purified from human stool.Using this animal model, we found that Blastocystis ST4 induced non inflammatory CHS in infected rats. In addition infected rats developed anxiety- and depressive-like behavior correlated with CHS. Infection associated intestinal dysbiosis was characterized by increased bacterial richness and decreased Firmicutes/Bacteroidetes ratio. Interestingly, we correlated CHS with the increase in the relative abundance of genus Bacteroides and the decrease in the relative abundance of the family Clostridiaceae, some bacteria producing Short Chain Fatty Acids (SCFAs). Indeed, fecal SCFAs levels were decreased in infected rats. These decreases were correlated with the relative abundance of genus Oscillospira which was also described increased in Blastocystis individual carriers. In addition, we have demonstrated an increase in fecal serine protease activity in infected animals that may explain development of CHS.These data suggest that a gastrointestinal infection with Blastocystis may be associated with the establishment of intestinal dysbiosis associated CHS. Thus, this new infectious model could be a good model of PI-IBS and could therefore contribute to a better diagnosis and development of new therapeutic strategies for chronic bowel diseases.
35

Investigating the microbial and immune mechanisms of depressive-like behaviour in a humanized mouse model of MDD

Hanuschak, Jennifer January 2020 (has links)
Major depressive disorder (MDD) is a highly heterogeneous disorder, with some patients displaying immune activation and altered intestinal microbiota composition when compared to healthy controls. In recent years, the transfer of fecal microbiota pooled from several MDD patients has been used to model depression in recipient rodents. However, we have previously observed the induction of donor-specific phenotypes in mice receiving microbiota from individual irritable bowel syndrome and generalized anxiety disorder patients. Therefore, we assessed the efficacy of fecal microbiota transplant (FMT) using individual versus pooled MDD patient microbiota to induce depressive-like behaviour in recipient rodents. We observed that pooling microbiota from several patients abrogated microbial features unique to individual donors. Mice that received pooled microbiota displayed different behavioural and immune phenotypes when compared to mice that received individual patient microbiota. Two individual MDD microbiota donors, patients MDD1 and MDD5, altered the behaviour of recipient mice when compared to controls. We identified several microbial species that may underlie the anxiety- and depressive-like behaviours observed in MDD1 and MDD5 mice. Additionally, altered expression of neural and immune genes was observed along the gut-brain axis of mice colonized with MDD1 microbiota. As microglia activation may play a role in our model, we developed a protocol for the isolation and phenotyping of adult mouse microglia that will facilitate future research efforts. Overall, our results demonstrate the heterogeneity of the microbial underpinnings of MDD and support the use of individual patient microbiota in future FMT experiments. / Thesis / Master of Science (MSc)
36

O receptor NLRP1 atua como um regulador do perfil de resposta Th17 em modelos experimentais e em humanos com diabetes tipo 1 / The NLRP1 receptor acts as a regulator of the Th17 response profile in Experimental and human models with type 1 diabetes

Costa, Frederico Ribeiro Campos 23 March 2018 (has links)
O diabetes tipo 1 (DM1) é uma doença autoimune caracterizada pela destruição das células b presentes nas ilhotas pancreáticas por linfócitos T auto-reativos, especialmente Th1 e Th17, levando o indivíduo a um estado de hiperglicemia. Embora existam diversos estudos que abordam a resposta imune adaptativa no contexto do DM1, poucos trabalhos tentaram elucidar o papel da resposta imune inata no desenvolvimento da doença. Neste contexto, avaliamos o perfil de expressão e o papel do receptor NLRP1 na patogênese do DM1 experimental e em humanos. Nossos dados apontam que no modelo de DM1 induzido por STZ, NLRP1 possui um papel protetor no desenvolvimento da doença de forma independente da ativação do inflamassoma, através da inibição da translocação de bactérias para os linfonodos pancreáticos (LNPs), além de reduzir a diferenciação de células Th17 e Tc17 nos LNPs, o que foi correlacionado à diminuição de IL-17 no pâncreas. Posteriormente, analisamos o papel de NLRP1 em outro modelo experimental, o NOD (nonobese diabetic), onde descrevemos que NLRP1 também é expresso no desenvolvimento da doença. Por fim, avaliamos o papel de NLRP1 em pacientes com DM1, através da genotipagem desses pacientes para um polimorfismo com ganho de função em NLRP1, o rs12150220. Ao contrário do que acontece em camundongos, NLRP1 em humanos parece ter um papel patogênico, uma vez que detectamos mais células T produtoras de IL-17 em células mononucleares do sangue periférico de indivíduos com o polimorfismo, além de níveis elevados da citocina no soro. Em suma, nossos dados apontam para papéis distintos de NLRP1 em camundongos e humanos com DM1, sugerindo cautela ao tentarmos transpor os achados sobre o receptor em camundongos para a clínica. / Type 1 diabetes (T1D) is an autoimmune disease that is caused by the destruction of the pancreatic b cells by autoreactive T cells, especially Th1 and Th17, leading to a state of hyperglycemia. Even though there are several studies on the role of the adaptive immune response in T1D, little is known about the role of an innate immune response in the development of the disease. Thus, we investigated the role of NLRP1 in the pathogenesis of mouse and human T1D. Our data indicate that in STZ-induced T1D, NLRP1 exerts a protective role in the development of the disease in an inflammasome-independent pathway, through the inhibition of bacterial translocation to the pancreatic lymph nodes (PLNs), and inhibition of the differentiation of Th17 and Tc17 cells in the PLNs, which correlated with decreased levels of IL-17 in the pancreas. Then, we analyzed the role of NLRP1 in nonobese diabetic (NOD) mice. We demonstrate that NLRP1 is also expressed in the development of T1D in this murine model. Lastly, we evaluated the role of NLRP1 in T1D patients, by genotyping these individuals for a polymorphism with a gain-of-function in NLRP1, the rs12150220. Unlike murine NLRP1, NLRP1 in humans appears to be pathogenic, considering that we detected more IL-17-producing T cells in peripheral blood mononuclear cells in patients carrying the polymorphism, besides elevated levels of this cytokine in the serum. Overall, our data suggest distinct roles for murine and human NLRP1 in the context of T1D, suggesting carefulness when translating the findings from murine NLRP1 to the clinic.
37

Isolamento e identificação de Lactobacillus spp., Bifidobacterium spp., Enterococcus spp., Pediococcus spp. e Lactococcus spp. da microbiota intestinal de Papagaio-verdadeiro (Amazona aestiva) / Isolation and identification of Lactobacillus spp., Bifidobacterium spp., Enterococcus spp., Pediococcus spp. and Lactococcus spp. from the intestinal microbiota of Blue-fronted Parrot (Amazona aestiva)

Allegretti, Luciana 18 September 2009 (has links)
No Brasil, o papagaio-verdadeiro (Amazona aestiva) é uma das aves mais procuradas como animal de estimação e comercializadas ilegalmente. Na literatura pouco é descrito sobre a microbiota intestinal de aves silvestres. O trato intestinal das aves é composto por inúmeras e diferentes espécies bacterianas. A grande maioria são bactérias gram-positivas pertencentes ao grupo de bactérias ácido-láticas. Este estudo teve como objetivo isolar e identificar a presença de bactérias dos gêneros Lactobacillus, Bifidobacterium, Enterococcus, Pediococcus e Lactococcus na microbiota entérica de papagaios Amazona aestiva de vida livre e de cativeiro. Para isto foram coletadas amostras de 26 aves de vida livre e de 26 aves procedentes de dois criadouros comerciais. O Enterococcus foi o gênero que apresentou maior freqüência de isolamentos (100%), seguido dos gêneros Pediococcus (63,46%), Lactobacillus (28,84%), Lactococcus e Bifidobacterium (15,38%). Foram isoladas 12 espécies de Enterococcus, sendo o E. faecium a espécie que apresentou maior ocorrência de isolamento, presente em 63,46% das aves, seguido por E. faecalis isolado em 57,69% das aves, Enterococcus sp. identificado em 46,15% das aves, E. hirae em 30,76% e E. raffinosus em 19,23%. Seis espécies de Pediococcus foram isoladas, sendo que P. pentosaceus foi a mais freqüente e esteve presente em 57,69% das aves. Foram isoladas cinco (5) espécies de Lactococcus, sendo L. lactis subsp. cremoris isolados em 3,84% das aves e Lactococcus sp. em 9,61%. Lactobacillus apresentou uma maior diversidade, com 14 espécies identificadas, sendo as mais freqüentes L. coryniformis subsp. torquens e L. sanfrancisco com 7,69% de aves positivas para cada espécie. Três (3) espécies de Bifidobacterium foram isoladas, sendo B. bifidum identificado em 9,61% das aves. Estudos complementares precisam ser conduzidos para uma melhor compreensão da microbiota intestinal das aves silvestres, assim como analisar as similaridades e diferenças com as aves domésticas, o que permitirá um manejo apropriado e menos empírico desta espécie em cativeiro. / In Brazil, Blue-fronted Parrot (Amazona aestiva) has been widely owned as a pet bird and, therefore, one of the Brazilians birds most frequently traded illegally in the Black Market. There are few reports in the current literature regarding to the microbiota of wild birds. The gastrointestinal tract of these birds has a wide variety of bacterial species; most of them are Gram positive bacteria and belongs to the lactic acid group. The present study has isolated and identified Lactobacillus, Bifidobacterium, Enterococcus, Pediococcus, and Lactococcus bacterias present in fecal samples of wild and captive Amazona aestiva parrots. Fifty two fecal samples were collected from 26 wild parrots and 26 parrots from commercial breeders. Enterococcus genus was the most frequently isolated (100%), followed by Pediococcus (63.46%), Lactobacillus (28.84%), Lactococcus and Bifidobacterium (15.38%). Twelve species of Enterococcus were identified. E. faecium was the most frequently isolated from the birds representing 63.46%, followed by E. faecalis (57.69%), Enterococcus sp. (46.15%), E. hirae (30.76%), and E. raffinosus (19.23%). P. pentosaceus was identified from 57.69% of the parrots. This specie was the most frequently isolated. Five different species of Lactococcus were found out. Lactococcus sp. was identified from 9.61% of the birds, while L. lactis subsp. lactis represented 3.84%. Fourteen different species of Lactobacillus were isolated, showing the biggest diversity among all the studied genera. L. coryniformis subsp. torquens and L. sanfrancisco were isolated from 7.69% of the birds. Three different species of Bifidobacterium were isolated, and B. bifidum was identified in 9.61% of the birds, being the most frequently isolated. Further studies are needed to a better comprehension of the microbiota in wild birds. Besides comparing differences and similarities between wildlife parrots and pet birds will allow appropriate and less empiric management of those birds in captivity.
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Isolamento e identificação de Lactobacillus spp., Bifidobacterium spp., Enterococcus spp., Pediococcus spp. e Lactococcus spp. da microbiota intestinal de Papagaio-verdadeiro (Amazona aestiva) / Isolation and identification of Lactobacillus spp., Bifidobacterium spp., Enterococcus spp., Pediococcus spp. and Lactococcus spp. from the intestinal microbiota of Blue-fronted Parrot (Amazona aestiva)

Luciana Allegretti 18 September 2009 (has links)
No Brasil, o papagaio-verdadeiro (Amazona aestiva) é uma das aves mais procuradas como animal de estimação e comercializadas ilegalmente. Na literatura pouco é descrito sobre a microbiota intestinal de aves silvestres. O trato intestinal das aves é composto por inúmeras e diferentes espécies bacterianas. A grande maioria são bactérias gram-positivas pertencentes ao grupo de bactérias ácido-láticas. Este estudo teve como objetivo isolar e identificar a presença de bactérias dos gêneros Lactobacillus, Bifidobacterium, Enterococcus, Pediococcus e Lactococcus na microbiota entérica de papagaios Amazona aestiva de vida livre e de cativeiro. Para isto foram coletadas amostras de 26 aves de vida livre e de 26 aves procedentes de dois criadouros comerciais. O Enterococcus foi o gênero que apresentou maior freqüência de isolamentos (100%), seguido dos gêneros Pediococcus (63,46%), Lactobacillus (28,84%), Lactococcus e Bifidobacterium (15,38%). Foram isoladas 12 espécies de Enterococcus, sendo o E. faecium a espécie que apresentou maior ocorrência de isolamento, presente em 63,46% das aves, seguido por E. faecalis isolado em 57,69% das aves, Enterococcus sp. identificado em 46,15% das aves, E. hirae em 30,76% e E. raffinosus em 19,23%. Seis espécies de Pediococcus foram isoladas, sendo que P. pentosaceus foi a mais freqüente e esteve presente em 57,69% das aves. Foram isoladas cinco (5) espécies de Lactococcus, sendo L. lactis subsp. cremoris isolados em 3,84% das aves e Lactococcus sp. em 9,61%. Lactobacillus apresentou uma maior diversidade, com 14 espécies identificadas, sendo as mais freqüentes L. coryniformis subsp. torquens e L. sanfrancisco com 7,69% de aves positivas para cada espécie. Três (3) espécies de Bifidobacterium foram isoladas, sendo B. bifidum identificado em 9,61% das aves. Estudos complementares precisam ser conduzidos para uma melhor compreensão da microbiota intestinal das aves silvestres, assim como analisar as similaridades e diferenças com as aves domésticas, o que permitirá um manejo apropriado e menos empírico desta espécie em cativeiro. / In Brazil, Blue-fronted Parrot (Amazona aestiva) has been widely owned as a pet bird and, therefore, one of the Brazilians birds most frequently traded illegally in the Black Market. There are few reports in the current literature regarding to the microbiota of wild birds. The gastrointestinal tract of these birds has a wide variety of bacterial species; most of them are Gram positive bacteria and belongs to the lactic acid group. The present study has isolated and identified Lactobacillus, Bifidobacterium, Enterococcus, Pediococcus, and Lactococcus bacterias present in fecal samples of wild and captive Amazona aestiva parrots. Fifty two fecal samples were collected from 26 wild parrots and 26 parrots from commercial breeders. Enterococcus genus was the most frequently isolated (100%), followed by Pediococcus (63.46%), Lactobacillus (28.84%), Lactococcus and Bifidobacterium (15.38%). Twelve species of Enterococcus were identified. E. faecium was the most frequently isolated from the birds representing 63.46%, followed by E. faecalis (57.69%), Enterococcus sp. (46.15%), E. hirae (30.76%), and E. raffinosus (19.23%). P. pentosaceus was identified from 57.69% of the parrots. This specie was the most frequently isolated. Five different species of Lactococcus were found out. Lactococcus sp. was identified from 9.61% of the birds, while L. lactis subsp. lactis represented 3.84%. Fourteen different species of Lactobacillus were isolated, showing the biggest diversity among all the studied genera. L. coryniformis subsp. torquens and L. sanfrancisco were isolated from 7.69% of the birds. Three different species of Bifidobacterium were isolated, and B. bifidum was identified in 9.61% of the birds, being the most frequently isolated. Further studies are needed to a better comprehension of the microbiota in wild birds. Besides comparing differences and similarities between wildlife parrots and pet birds will allow appropriate and less empiric management of those birds in captivity.
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Detecção e quantificação de bactérias anaeróbias na microbiota fecal de crianças de zero a 12 meses de idade / Detection and quantification of anaerobic bacteria in the fecal microbiota of children aged zero to twelve months of age

Talarico, Silvia Toledo 01 March 2013 (has links)
A sequência de eventos bacterianos que ocorre durante a colonização do trato gastrointestinal pode afetar o futuro da saúde do hospedeiro, particularmente no que diz respeito à regulação do sistema imunológico. Um entendimento claro do processo de colonização do intestino humano neonatal nos países em desenvolvimento está faltando, porque os poucos estudos disponíveis foram, em sua maioria, realizados utilizando técnicas de cultura. O objetivo deste estudo foi detectar e quantificar as bactérias dos gêneros Bifidobacterium, Lactobacillus, Eubacterium e Lactococcus, importantes componentes anaeróbios da microbiota intestinal usando PCR em tempo real. O grupo de estudo foi composto por 10 crianças, acompanhadas durante o primeiro ano de vida, vivendo em baixas condições sócio-econômicas em São Paulo, Brasil. Amostras de fezes foram avaliadas em períodos de 24 horas, 7 dias, 30 dias, 3 meses, 6 meses e 1 ano. Durante o primeiro ano de vida, há um aumento da quantidade de Bifidobacterium spp., quando comparada com as outras bactérias anaeróbias estudadas, com médias variando de 8,27x1010 a 2,51x1012 número de cópias de DNA/g de fezes. Lactobacillus spp. também foi encontrado em todos os pontos de tempo estudado, com médias variando de 4,03x108 a 1,46x1010 número de cópias de DNA/g de fezes. Lactococcus spp. foi o gênero bacteriano encontrado em quantidades menores. As contagens máximas desses gêneros foram encontradas entre o terceiro e sexto mês de vida. Embora o gênero Eubacterium seja descrito como um dos principais membros da microbiota intestinal, este foi encontrado em amostras de apenas duas crianças. A inclusão de dieta sólida e a mudança do tipo de amamentação influenciam a composição da microbiota. No entanto, não se pode estabelecer um padrão para a presença destes micro-organismos ao longo dos meses, mostrando que a microbiota é única e está sujeita a interferências ambientais. / The sequence of bacterial events that occurs during the colonization of the gastrointestinal tract may affect the future health of the host, particularly with respect to the regulation of the naive immune system. A clear understanding of the colonization process of the human neonatal gut in developing countries is lacking because the few available studies were mostly performed using culture techniques. The aim of this study was to detect and quantify the bacterial genera Bifidobacterium, Eubacterium, Lactobacillus and Lactococcus, important anaerobic components of the intestinal microbiota using real-time PCR. The study group comprised 10 children followed during the first year of life, living in low socio-economic conditions in São Paulo, Brazil. Fecal samples were evaluated at times of 24 hours, 7 days, 30 days, 3 months, 6 months and 1 year. During the first year of life, there is an increased amount of Bifidobacterium spp. compared to others studied anaerobic bacteria, with averages ranging from 8,27x1010 to 2,51x1012 DNA copy number/g of feces. Lacotbacillus was also found in all studied time point, with averages ranging from 4,03x108 to 1,46x1010 DNA copy number/g of feces. Bacterial genus Lactococcus is found in smaller quantities. The maximum counts of these genera were found between the third to sixth month of life. Although the genus Eubacterium is described as one of the leading members of the intestinal microbiota, this was found in samples of only 2 children. The inclusion of solid diet and change of type of feeding influences the composition of the microbiota, however, could not set a standard for the presence of these micro-organisms over the months, showing that the microbiota is unique and is subject to environmental interference.
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Modulação da microbiota intestinal de perus de corte desafiados com Salmonella Heidelberg e submetidos a diferentes programas de controle / Modulation of intestinal microbiota of commercial turkeys challenged with Salmonella Heidelberg and submitted to different control programs

Silva, Tarcísio Macedo 14 November 2017 (has links)
Submitted by TARCISIO MACEDO SILVA null (tarcisiomedvet@hotmail.com) on 2017-12-12T20:53:29Z No. of bitstreams: 1 Dissertação Tarcísio Macedo Silva.pdf: 1757310 bytes, checksum: 128f6aff84e23e2e9f3f06ad11db8914 (MD5) / Approved for entry into archive by ROSANGELA APARECIDA LOBO null (rosangelalobo@btu.unesp.br) on 2017-12-13T12:33:12Z (GMT) No. of bitstreams: 1 silva_tm_me_bot.pdf: 1757310 bytes, checksum: 128f6aff84e23e2e9f3f06ad11db8914 (MD5) / Made available in DSpace on 2017-12-13T12:33:12Z (GMT). No. of bitstreams: 1 silva_tm_me_bot.pdf: 1757310 bytes, checksum: 128f6aff84e23e2e9f3f06ad11db8914 (MD5) Previous issue date: 2017-11-14 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente estudo avaliou uso de ácidos orgânicos (AOs), probiótico e produto de exclusão competitiva (EC) administrados continuadamente, via ração, no controle de Salmonella Heidelberg (SH) e a ação sobre a microbiota e morfometria intestinal. Cento e setenta perus de corte fêmeas foram distribuídas, aleatoriamente, em cinco tratamentos com quatro repetições de oito aves cada. No terceiro e no décimo dia de vida, os animais foram submetidos ao desafio oral de SH. No sétimo, 19º e 35º de vida as aves foram eutanasiadas (n=10 por tratamento) e colhido amostras de segmentos do inglúvio, duodeno, jejuno, íleo e ceco para quantificação de SH, quantificação relativa do microrganismo Faecalibacterium prausnitzii e análise morfométrica. No decorrer do período experimental foram realizadas colheitas de suabes cloacais para pesquisa de SH. A administração do probiótico e produto de EC foi capaz de reduzir a incidência e a colonização de SH no inglúvio. Nos cecos os tratamentos reduziram a colonização de SH somente aos 19 dias de idade. Somente a dieta suplementada com AOs influenciou positivamente na quantidade de F. prausnitizii no ceco (19 e 35 dias) e não houve correlação entre a quantidade relativa desse microrganismo e o número de UFCs de SH. A excreção fecal de SH, foi influenciada pelos tratamentos a partir dos 26 dias de vida das aves, aos 34 dias todos os tratamentos reduziram a excreção fecal. A morfometria intestinal foi influenciada pelos tratamentos somente aos sete dias de vida, onde os animais que receberam AOs apresentaram maiores alturas de vilosidades de jejuno quando comparado com o grupo controle positivo. A administração dos aditivos via ração demonstrou eficácia no controle e na persistência da infecção por SH. No entanto, o uso de AOs foi mais eficaz para modular a microbiota cecal, provando que a composição da dieta pode modular populações de bactérias benéficas, mas tais microrganismos podem não estar correlacionadas com a redução da colonização cecal por SH. / The present study evaluated the use of organic acids (AOs), probiotic and competitive exclusion (CE) product administered continuously in the feed on the control Salmonella Heidelberg (SH) and action microbiota and morphometry intestinal. One hundred and seventy poults females were randomly distributed in five treatments with four replicates of eight birds each. In the 3rd and 10th day of life, the animals were submitted to the challenge with SH. In the 7th, 19th and 35th of life the birds were euthanized (n = 10) and samples of the crop, duodenum, jejunum, ileum and caeca were removed to quantification of SH, quantification relative of the Faecalibacterium prausnitzii and morphometric analysis. During the experimental period were perfomerd clocal swabs for SH research. The administration of probiotic and CE product was able to reduce the incidence and colonization of SH in the crop. In the caecum the treatments reduced SH only 19 days of age. Only the diet supplemented with AOs influenced positively on amount of F. prausnitizii in the cecum (19 and 35 days) and there was no correlation between the amount on the microorganism and the number of UFCs of SH. Fecal excretion of SH, was influenced by the treatments from 26 days of life, at 34 days all treatments reduced faecal excretion. The intestinal morphometry was influenced by the treatments only to seven days of age, where the animals that received AOs had higher jejunal villus heights of villi when compared with the positive control. The feed additives administration demonstrated effectiveness in controlling and in the persistence of the infection by SH. However, the use of AOs was most effective to modulate the cecal microbiota, proving that the composition of the diet can modulate populations of beneficial bacteria, but such microorganisms may not be correlated with the reduction of the SH / Processos: FAPESP 2015/16428-5; 2015/18350-3

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