Tendo sido comprovada a existência da famílias molecularmente distintas de M. avium circulando em suínos de região sul do Brasil, e havendo dúvidas a respeito da importância da transmissão horizontal como mecanismo de manutenção da doença, o presente teve por objetivo estudar a virulência dessas estirpes, informação importente para o aperfeiçoamento dos métodos de controle. As estirpes emergiram do estudo caso-controle, onde as tipagens moleculares por RFLP mostraram a existência de quatro famílias de M. avium (PIG-A, B, C e D). Um estirpe representante de cada família foi inoculada pela via intra-peritoneal em 48 hamsters com uma dose de 30.000 U.F.C. por animal. Após 2, 13, 26 e 40 dias da inoculação, 12 hamsters inoculados de cada família foram anestesiados, sacrificados e os agentes foram quantificados no fígado, baço e pulmão. A presença das estirpes foi verificada no sangue e também foram realizados exames histológicos. As estipers PIG-A, B, C e D desenvolveram lesões granulomatosas no fígado e baço nos quatro tempos experimentais; disseminaram-se pela via linfo-hemática, multiplicando-se em fígado, baço e pulmão. Nos quatro tempos experimentais houve diferença entre as contagens de U.F.C./g entre os órgãos (T1: p<0,001; T2: p<0,001; T3: p<0,001 e T4: p<0,001) e as obtidas do baço foram sempre superiores às do fígado e pulmão. Nos quatro tempos experimentais houve diferença entre as contagens de U.F.C./g entre as estirpes (T1: p<0,001; T2: <0,001; T3: p<0,001 e T4: p<0,001) e foi possível construir a seguinte escala decrescente de virulência: PIG-B > PIG-A > PIG-D > PIG-C. / Given that the existence of molecularly different families of M. avium circulating in swine of the south area of Brazil has been proved, and that some doubts remain regarding the importance of the horizontal transmission as mechanism of maintenance of the disease, this work aimed to study the virulence of those strains, an important information for the improvement of the control methods. The strains emerged from a case-control study, when the RFLP molecular typification showed the existence of four families of M. avium (PIG-A, B, C and D). A strain representative of each family was inoculated by intra-peritoneal route in 48 hamsters with a dose of 30.000 C.F.U./animal. After 2, 13, 26 and 40 days post-infection, 12 inoculated hamsters of each family were anesthetized, euthanized and the bacteria were quantified in the liver, spleen and lung. The presence of the strains was verified in the blood and also histological exams were accomplished. The strains PIG-A, B, C and D developed granulomatous lesions in the liver and spleen in the four experimental times; they were disseminated by the linfo-haematic route, multiplying in liver, spleen and lung. In the four experimental times there was difference among the countings of C.F.U./g among the organs (T1: p<0,001; T2: p<0,001; T3: p<0,001 and T4: p<0,001) and that obtained of the spleen were always superiors to the one of the liver and lung. In the four experimental times there was difference among the countings of C.F.U./g among the ancestries (T1: p<0,001; T2: p<0,001; T3: p<0,001 and T4: p<0,001) and was possible to build the following order of decreasing virulence: PIG-B > PIG-A > PIG-D > PIG-C.

Descrevem-se os aspectos epidemiológicos e clínico-patológicos da paratuberculose em um rebanho de búfalos no Município de Guaíba no Rio Grande do Sul. A propriedade possuía cento e noventa e quatro búfalos principalmente da raça mediterrâneo e destinava-se a produção de leite e carne. No período de abril de 2009 a setembro de 2010 seis búfalos apresentaram diarreia crônica intermitente, perda de peso e apetite normal. Na neccropsia observaram-se vasos linfáticos proeminentes no mesentério e na mucosa do intestino. Os linfonodos mesentéricos estavam moderadamente aumentados, com áreas escuras entremeadas com focos multinodulares brancacentos, principalmente na região cortical. A mucosa do intestino se encontrava espessa e cerebriforme. Ao exame histológico, desde o duodeno até o intestino grosso havia infiltrado composto principalmente por macrófagos epitelióides e, em menor escala, linfócitos, plasmócitos e células gigantes tipo Langhans. Outros achados observados foram dilatação dos vasos linfáticos, linfangite granulomatosa e linfangiectasia. Nos linfonodos mesentéricos verificaram-se lesões histológicas semelhantes. A coloração de Ziehl-Neelsen e a imuno-histoquimica revelaram bacilos álcool-ácido resistentes no interior de macrófagos, de células gigantes de Langhans e livres na mucosa e submucosa do intestino e dos linfonodos mesentéricos. Mycobacterium avium subsp. paratuberculosis foi isolado em cultivo bacteriano de amostras de fezes, raspado de mucosa intestinal e de linfonodos mesentéricos. A identificação do agente foi realizada pela técnica de PCR IS900. Foi realizado, também, levantamento sorológico de 136 búfalos da propriedade através da técnica de ELISA, na qual foram observados 15,45 % reagentes. O diagnóstico da paratuberculose foi baseado nos dados clínicopatológicos, sorologia, isolamento e identificação do agente. / It´s described the epidemiologic, clinical and pathologic aspects of paratuberculosis in a bubaline herd in Guaiba city, southern Brazil. The property had one hundred and ninety animals for milk and meet production. Six adults Mediterranean breed bubalines showed chronic intermittent diarrhea, lost of weight and normal appetite. At necropsy, the lymphatic vessels were prominent in the serosa, the mesenteric lymphnodes were slightly enlarged with dark areas interwoven by multinodular white spots mainly in the cortical region. The intestine mucosa were thickened and of corrugated aspect. The microscopic exam revealed severe diffuse granulomatous inflammation, marked dilatation of the lymphatic vessels, granulomatous lymphangitis and lymphangioectasia from the duodenum to the large bowl. The mesenteric lymphnodes showed similar histological lesions. Acid-fast bacilli in macrophages, in Langhans giant cells and freely in the mucosa and submucosa of the small intestine and lymphnodes were shown at Ziehl-Neelsen staining and immunohistochemistry. Mycobacterium avium subsp. paratuberculosis was isolated through bacterial cultivation of samples taken from feces, intestinal mucosa, mesenteric lymphnodes, and identified through IS900 PCR. In addition, a serologic survey was performed in the property by ELISA test. 15.45 percent of the animals reacted positive to the test. The diagnosis of paratuberculosis was based on clinical, pathological and epidemiological data, serology exam, bacterial isolation and identification of the agent.

Dada a existência de quatro famílias molecularmente distintas de estirpes de Mycobacterium avium isoladas de suínos da região Sul do Brasil e a verificação de diferentes virulências em hamsters de um representante por família, o presente trabalho objetiva relacionar a virulência de isolados de M. avium aos seus perfis genéticos obtidos em experimentos de RFLP. Foram selecionados três representantes por família que foram inoculados pela via intraperitoneal em hamsters distribuídos em doze grupos (cada grupo recebeu uma estirpe diferente). Foi mantido um grupo controle que recebeu solução salina estéril pela mesma via. Após 16 dias da inoculação, os animais foram eutanasiados; os baços foram colhidos, pesados, macerados, suspendidos em solução salina estéril e diluídos. Cada uma das diluições foi semeada em duplicata em placas com meio de Petragnani, que foram incubadas a 37°C. Após 30 dias de incubação, foram realizadas as contagens de UFC e os resultados foram expressos em UFC de M. avium por grama de baço. As famílias genéticas apresentaram capacidade de virulência semelhante (p=0,49). As estirpes dentro das famílias PIG B e PIG D não apresentaram diferença na virulência (p=0,15 e p=0,87, respectivamente). Dentro da família PIG A, o isolado A52 foi mais virulento do que A1 e A162; a estirpe C122 se apresentou menos virulenta do que as estirpes C44 e C68 dentro da família PIG C. Independente das famílias, todos os isolados apresentaram diferenças na virulência. A estirpe A52 mostrou maior capacidade de virulência em relação às estirpes A1, A162, B72, C122, D242 e 243. Diferentes contagens de UFC significam diferentes capacidades de produzir infecção, ou seja, diferentes virulências. Concluiu-se que isolados de M. avium com diferentes perfis de RFLP podem apresentar diferentes virulências, independentemente de pertencerem a uma mesma família genética definida com base na similaridade dos padrões de RFLP; não houve diferença de virulência entre as quatro famílias genéticas de M. avium estruturadas com base na similaridade dos padrões de RFLP. / Knowing the existence of four molecularly distinct families of Mycobacterium avium strains isolated from swine populations of Brazil Southern and the corroboration of diverse virulence in experimentally infected hamsters by one representative of each family, this work intend to establish relation between virulence of M. avium isolates and their genetic patterns obtained in prior RFLP analyses. We selected three representatives of each family, totalizing twelve strains, which were introduced by intraperitoneal route into hamsters distributed in twelve groups (each group received a different strain). A control group was maintained and received buffer solution by the same route. Sixteen days after the inoculation, animals were euthanized and their spleens were collected, weighted, triturated, suspended in buffer solution and then diluted. Two plates containing Petragnani medium were seeded with each dilution and were incubated at 37ºC. At the 30th day, the CFU counting was performed and the results were expressed in M. avium CFU/g of spleen. All genetic families presented similar capacity of virulence (p=0,49). Strains of PIG B and PIG D families presented similar virulence within their families (respectively, p=0,15 and p=0,87). Inside the PIG A family, strain A52 was more virulent than strains A1 and A162; the strain C122 presented the lowest virulence compared with the strains C44 and C68 within the PIG C family. All strains, independent of their family, presented diverse virulence. Strain A52 was more virulent than strains A1, A162, B72, C122, D242 and D243. Distinct counting of CFU means different capacity of producing infection, i.e. diverse virulence. We concluded that, independent fo the genetic family established by similarity of RFLP patterns, M. avium isolates with diverse RFLP profiles may present different virulence; there was not difference in virulence; among all of four M. avium genetic families structured according to the similarity of RFLP patterns.

Immunological and ultrastructural changes in mononuclear cells exposed to Mycobacterium avium serovar-specific glycopeptidolipid (GPL) and the chemically derived R-lipid (lipopeptide fragment) were examined.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Memoria para optar al Título Profesional de Médico Veterinario / La Paratuberculosis es una enfermedad infecto contagiosa crónica con un largo período de incubación causada por Mycobacterium avium subsp. paratuberculosis (MAP), que afecta principalmente a los rumiantes, generando diarrea en algunas especies, caquexia y debilitamiento progresivo y como consecuencia, perdidas económicas en los rebaños. También infecta a animales silvestres que actuarían como posibles reservorios y se le asocia un posible potencial zoonótico, habiendo sido aislada la bacteria en algunos pacientes con la Enfermedad de Crohn, siendo el posible vehículo de infección la leche, ya que esta bacteria resistiría la pasteurización. En este estudio se trata de detectar la presencia de Mycobacterium paratuberculosis desde heces de caprinos de la región Metropolitana. Se realizaron cultivos bacteriológicos para M. paratuberculosis según recomendaciones del Australian Standard Diagnostic Techniques (ASDT) y con las modificaciones que permiten una mejor eficiencia en la recuperación de la bacteria. El medio de cultivo para aislamiento primario es el medio de Herrold con yema de huevo (HEYM) más mycobactina J. Se tuvo acceso a 10 rebaños donde se seleccionaron el número de animales en múltiplos de cinco, tratando de abarcar el 25% de la población de cada rebaño. Se recolectaron muestras directamente desde el recto, tomando 1 a 2 heces de cada caprino, que se depositaron en bolsas de plástico estéril agrupándose en “pools” de cinco animales. Para tener una mayor probabilidad de detectar rebaños caprinos infectados con MAP, se consideraron hembras mayores de un año, y en lo posible animales que hayan presentado signos de diarrea, debilitamiento, pérdida de peso progresiva, disminución de la producción láctea, etc. Se comprobó la presencia de MAP desde heces de caprinos de la Región Metropolitana en 3 rebaños de los 10 muestreados, encontrándose un 18% de los “pools” positivos a MAP. El medio HEYM más la adición de mycobactina J demostró claramente ser muy efectiva para el aislamiento del MAP a partir de muestras de heces de animales que ya estaban diseminando el microorganismo

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2009. / Härtill 5 uppsatser.

Johne’s disease (JD) in cattle is a disease of economic importance caused by Mycobacterium avium subspecies paratuberculosis (MAP). Studies were conducted to estimate the losses due to lower weaning weight of beef calves from MAP test-positive dams, to compare the perceptions of producers and veterinarians on the burden and economic aspects of MAP infection in cow-calf herds, and to evaluate whether testing and culling MAP test-positive cows is economically beneficial. Calves from cows with strong-positive ELISA results were 21.5 kg lighter at weaning compared to calves from ELISA-negative cows. Calves from heavy MAP shedding cows were 58.5 kg lighter, and calves from moderate shedders were 40.8 kg lighter compared to the calves from fecal-culture negative cows. Based on average feeder calf value during 2007 to 2012, these losses corresponded to US $57 per calf for ELISA strong-positive dams, US $157 per calf for heavy fecal shedder dams, and US $109 per calf for a moderate fecal shedder dam. Seedstock producers and the producers enrolled in control programs were more likely to have MAP uninfected herds. The average prevalence reported by producers was 0.8%. Compared to the small herds (<50 head), the average test-positive percentages and estimated prevalences were reported to be higher in medium (50-149) and highest in large (≥150) herds. Veterinarians reported an overall animal level prevalence in their client herds of 5%. Seedstock herds had a lower prevalence and these producers were more likely to enroll in a JD control program. Income lost due to the presence of JD in an infected cattle herd was perceived to be higher by veterinarians. Compared to the veterinarians, seedstock producers were more likely to perceive genetic losses due to culling MAP positive cows. Average annual loss due to JD in a 100 cow herd with a 7% MAP prevalence was $1,644 and $1,747 based on information provided by producers and veterinarians, respectively. Herd level production decreased with increasing prevalence. Compared to test and cull after ELISA or ELISA followed by fecal culture, using fecal culture alone provided the fastest reduction in herd prevalence. Fecal culture was also the least costly alternative based on long-term cumulative costs of an annual test and cull program. Results from the current study suggest that although testing provides faster progress, limiting within herd transmission by sale of all weaned calves and purchasing only low-risk replacements can also reduce prevalence. Results suggest that MAP infection in cows causes significant losses for the calves that are produced. While the knowledge about JD varied between producers and veterinarians, seedstock producers were more enthusiastic about MAP control programs and had lower MAP prevalence in their herds. Overall losses due to MAP infection in the herd might be substantial. It is very costly to control or eliminate MAP once the infection is established in a herd.

La paratuberculose bovine, ou maladie de Johne, est une maladie inflammatoire intestinale chronique provoquant d’importantes pertes économiques chez les producteurs de ruminants du monde entier. Que ce soit chez la vache laitière ou de boucherie, ces pertes sont causées majoritairement par une diminution de la capacité de reproduction, la baisse de production laitière et l’amaigrissement des vaches qui perdent ainsi beaucoup de valeur à l’abattage, en plus d’être sujettes à une réforme précoce. Outre les pertes économiques, le potentiel de transmission à l’humain est un facteur non négligeable en plus d’un risque de contamination de la chaîne alimentaire. Cette maladie est causée par une bactérie intracellulaire obligatoire nommée Mycobacterium avium subspecies paratuberculosis (MAP). II n’existe actuellement aucune stratégie efficace pour combattre l’infection chez les animaux atteints. L’évolution lente de la maladie fait en sorte que les signes cliniques apparaissent tardivement, soit plusieurs années (4 à 7 ans) après l’infection initiale. Au cours de cette progression, les animaux infectés commencent à excréter le pathogène dans leur environnement. Les animaux atteints deviennent infectieux et peuvent contaminer d’autres congénères, ainsi que leur propre veau. Afin de permettre aux producteurs d’éliminer les vaches atteintes avant qu’elles n’atteignent ce stade, il s’avère important d’établir un diagnostic précoce. Actuellement, ce n’est qu’en phase sous-clinique avancée que les tests diagnostiques sont plus sensibles, soit 2 à 3 ans après le début des excrétions fécales chez les animaux infectés. L'incompréhension du manque de sensibilité des tests de dépistage et de l'évolution de cette maladie justifient les efforts de recherche dans ce domaine en vue de mieux comprendre les réponses immunitaires impliquées dans cette maladie. En effet, une meilleure connaissance des processus d’inflammation chronique pourrait aider à développer des outils diagnostiques complémentaires. Nos résultats suggèrent une dérégulation de la réponse immunitaire. Ainsi, en étudiant les composantes et caractéristiques du sang provenant de vaches infectées, il nous a été possible d’observer que les niveaux de cytokines plasmatiques telles l’interleukine 17 et l'ostéopontine se trouvent sécrétées à différents niveaux chez les vaches atteintes de paratuberculose bovine. De plus, l'analyse de la capacité de leur sérum à soutenir efficacement la prolifération des cellules mononucléées du sang périphérique révèle que le sérum de vaches infectées interfère pour atténuer la prolifération cellulaire. II semble qu’un constituant du sérum provoque une diminution de la réponse immunitaire chez les vaches malades. Les résultats offrnt une appréciation des dérèglements immunitaires provoqués par la paratuberculose bovine.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 152-176).