A piodermite bacteriana afeta cães de todas as idades, podendo ser recorrente por toda a vida. O principal agente etiológico é o Staphylococcus pseudintermedius, que é um micro-organismo saprófita da pele, agindo como oportunista frente a alguma fragilidade na barreira imunológica. A imunização dos cães através de uma vacina eficaz tem sido um desafio, pois a vacina comercial atualmente utilizada em clínicas veterinárias é de uso terapêutico e não tem caráter preventivo. Um dos problemas da vacina de uso terapêutico para piodermite é a dependência de um bom diagnóstico diferencial em relação a outras doenças de pele ou sistêmicas que tem como sequelas a erupção cutânea. Os animais que recebem a vacina terapêutica e não a preventiva são os que já apresentam problemas de pele reincidentes e são tratados concomitantemente com antibióticos. O objetivo do presente trabalho é desenvolver um antígeno vacinal com possibilidade de aplicação por via intradérmica de modo a tratar preventivamente a piodermite canina causada por Staphylococcus spp:. A via de administração intradérmica tem como finalidade estimular uma resposta imune sistêmica, principalmente por ativação das células dendríticas da derme, de modo a estimular estas células apresentadoras de antígeno no local onde ocorrem as infecções piodérmicas. Os resultados apresentados neste trabalho demonstraram que a inoculação intradérmica foram estatisticamente igual, quando comparada com a inoculação intraperitoneal, no que se refere à inibição por anticorpos: da atividade hemolítica, da atividade da catalase, da atividade da coagulase e da atividade citotóxica, bem como na reação antígeno-anticorpo determinado por ensaio imunoenzimático. Este trabalho também demonstra que a melhor formulação do antígeno estafilocóccico foi preparado a partir de sobrenadante de cultura diafiltrado por filtração tangencial com \"cut off\" de 5.000 Da. Outras preparações utilizando somente células bacterianas ou associação de sobrenadante com células bacterianas, apesar de produzirem antigenicidade, apresentaram títulos inferiores do que quando empregado somente sobrenadante de cultura diafiltrado. / The bacterial pyoderma affects dogs of all ages and can be recurrent for a lifetime. The main etiologic agent is Staphylococcus pseudintermedius, which is a saprophytic organism of the skin, acting as an opportunistic opposite to some weakness in the immune barrier. The immunization of dogs through an effective vaccine has been a challenge, since currently it has been used commercially in veterinary clinics is therapeutic and has a preventive character. One of the problems of the therapeutic use of the vaccine for pyoderma is dependent on a good differential diagnosis in relation to other skin diseases or systemic consequences which is the rash, so treatment often does not reach its goal. Animals receiving this vaccine are those who already have skin problems again and are receiving concomitant antibiotics. The objective of this study is to develop a vaccine antigen with the possibility of implementing a preventive treatment for canine pyoderma caused by Staphylococcus spp: through pre-clinical studies, for use in young and adults, preferably before they develop any type of skin disorder primary or secondary. The administration route is intradermal, stimulating an immune response primarily by dendritic cells to become a barrier to microorganisms, as well as systemic, by the production of antibodies, to last for at least one year until needed in the body booster vaccination. The results presented here demonstrated that the intradermal inoculation was statistically equivalent when compared to intraperitoneal inoculation with regard to inhibition by antibody: of the hemolytic activity, catalase activity, the coagulase activity and cytotoxic activity, as well as antigen-antibody reaction determined by enzyme immunoassay. This work also demonstrates that the best estafilococcico antigen formulation was prepared from the culture supernatant diafiltered by tangential filtration with \"cut off\" of 5,000 Da. Other preparations using only the bacterial cells or the association of supernatant with bacterial cells, although producing antigenicity, showed lower titles than when used dialyzed culture supernatant alone.

A piodermite bacteriana afeta cães de todas as idades, podendo ser recorrente por toda a vida. O principal agente etiológico é o Staphylococcus pseudintermedius, que é um micro-organismo saprófita da pele, agindo como oportunista frente a alguma fragilidade na barreira imunológica. A imunização dos cães através de uma vacina eficaz tem sido um desafio, pois a vacina comercial atualmente utilizada em clínicas veterinárias é de uso terapêutico e não tem caráter preventivo. Um dos problemas da vacina de uso terapêutico para piodermite é a dependência de um bom diagnóstico diferencial em relação a outras doenças de pele ou sistêmicas que tem como sequelas a erupção cutânea. Os animais que recebem a vacina terapêutica e não a preventiva são os que já apresentam problemas de pele reincidentes e são tratados concomitantemente com antibióticos. O objetivo do presente trabalho é desenvolver um antígeno vacinal com possibilidade de aplicação por via intradérmica de modo a tratar preventivamente a piodermite canina causada por Staphylococcus spp:. A via de administração intradérmica tem como finalidade estimular uma resposta imune sistêmica, principalmente por ativação das células dendríticas da derme, de modo a estimular estas células apresentadoras de antígeno no local onde ocorrem as infecções piodérmicas. Os resultados apresentados neste trabalho demonstraram que a inoculação intradérmica foram estatisticamente igual, quando comparada com a inoculação intraperitoneal, no que se refere à inibição por anticorpos: da atividade hemolítica, da atividade da catalase, da atividade da coagulase e da atividade citotóxica, bem como na reação antígeno-anticorpo determinado por ensaio imunoenzimático. Este trabalho também demonstra que a melhor formulação do antígeno estafilocóccico foi preparado a partir de sobrenadante de cultura diafiltrado por filtração tangencial com \"cut off\" de 5.000 Da. Outras preparações utilizando somente células bacterianas ou associação de sobrenadante com células bacterianas, apesar de produzirem antigenicidade, apresentaram títulos inferiores do que quando empregado somente sobrenadante de cultura diafiltrado. / The bacterial pyoderma affects dogs of all ages and can be recurrent for a lifetime. The main etiologic agent is Staphylococcus pseudintermedius, which is a saprophytic organism of the skin, acting as an opportunistic opposite to some weakness in the immune barrier. The immunization of dogs through an effective vaccine has been a challenge, since currently it has been used commercially in veterinary clinics is therapeutic and has a preventive character. One of the problems of the therapeutic use of the vaccine for pyoderma is dependent on a good differential diagnosis in relation to other skin diseases or systemic consequences which is the rash, so treatment often does not reach its goal. Animals receiving this vaccine are those who already have skin problems again and are receiving concomitant antibiotics. The objective of this study is to develop a vaccine antigen with the possibility of implementing a preventive treatment for canine pyoderma caused by Staphylococcus spp: through pre-clinical studies, for use in young and adults, preferably before they develop any type of skin disorder primary or secondary. The administration route is intradermal, stimulating an immune response primarily by dendritic cells to become a barrier to microorganisms, as well as systemic, by the production of antibodies, to last for at least one year until needed in the body booster vaccination. The results presented here demonstrated that the intradermal inoculation was statistically equivalent when compared to intraperitoneal inoculation with regard to inhibition by antibody: of the hemolytic activity, catalase activity, the coagulase activity and cytotoxic activity, as well as antigen-antibody reaction determined by enzyme immunoassay. This work also demonstrates that the best estafilococcico antigen formulation was prepared from the culture supernatant diafiltered by tangential filtration with \"cut off\" of 5,000 Da. Other preparations using only the bacterial cells or the association of supernatant with bacterial cells, although producing antigenicity, showed lower titles than when used dialyzed culture supernatant alone.

The aetiology of autoimmune disease is a complex interplay between genetics, environment and immunological regulation. Our understanding of the genetic aspects of autoimmunity has increased with recent findings from Genome Wide Association Studies (GWAS). There is now a movement towards meta-analyses of GWA studies in order to increase the number of genetic loci detected. There are also efforts to detect common genetic risk factors amongst groups of diseases that potentially share common aetiopathogenic pathways. Animal models have formed the basis of many genetic discoveries and the domestic dog presents a spontaneous model for many diseases, including autoimmunity. Through man’s efforts to create specific breeds, the dog has acquired a genomic architecture consisting of long haplotype blocks and extensive linkage disequilibrium. This means that a GWAS can be conducted in dog breeds with fewer samples and fewer markers than an equivalent study in humans, reducing costs, cohort collection times, and data handling/storage considerations. Successful canine GWA studies are now starting to be published. Building upon this success, the findings from GWA studies in three canine autoimmune diseases (across six different breeds), with equivalent human pathologies, are presented. Dogs with diabetes mellitus (similar to latent autoimmune diabetes of adulthood in man), lymphocytic thyroiditis (similar to Hashimoto’s thyroiditis), and anal furunculosis (similar to perianal Crohn’s disease) were compared to control dogs to identify genetic susceptibility loci underlying disease. Follow-up genotyping of the top hits from the GWAS analyses were conducted to replicate findings and to better characterise the diseases across a number of dog breeds. Typing of MHC class II genes, important in the immune response, was also undertaken in canine diabetes mellitus and canine lymphocytic thyroiditis. In anal furunculosis, high-throughput, next-generation sequencing was utilised to identify novel mutations and fine-map associations at discovered loci. Several genes were identified in all of these canine autoimmune diseases, many with good candidate function. Some of these genes indicated common genetic susceptibility loci and pathways between canine autoimmune diseases. Breed-specific genetic effects underlying canine diabetes mellitus and canine lymphocytic thyroiditis were identified, which has implications for disease diagnosis and clinical management. Novel loci for investigation in the corresponding human disease studies have been identified and future work will begin to genetically link the conditions in dog and man.

A series of experiments with Aeromonas salmonicida and infectious hematopoietic necrosis virus (IHNV) were carried out to determine dynamics of the spread of infection in chinook salmon (1.2-1.98g) and rainbow trout (1.2-3.1g). It was found in experiments with A. salmonicida that fish infected by bath immersion became infectious at 4 days postexposure (dpe), one day prior to dying from furunculosis. In cohabitation experiments with a single infected fish donor, an average of 75% disease specific mortality was obtained. There was suggestive evidence that there is a positive relationship between holding volumes and furunculosis prevalence in cohabitation experiments with single donor fish. Median day to infection was inversely correlated with density. The threshold density at density of 1.97 fish/L was approximately 30 times less than the density of 0.08 fish/L, 13.33 and 320 fish respectively. Reproductive ratio (R₀) and transmission coefficient (β) in the furunculosis epizootic were 3.23 and 0.021 (individuals*day)⁻¹ respectively. The mortality rate (α) of infected animals was 28.7% per day. The models constructed successfully mirrored the results of laboratory experiments. Data produced by simulation of the models were significantly associated with the data obtained from laboratory experiments for susceptible (S) class and also for infected class. In similar experiments carried out with IHNV, it was found that donor fish became infectious 3 dpe. The virus levels in donor fish and prevalence levels were also highly associated. Smaller volumes of that led to higher prevalence levels than observed in bigger volumes with 60 or 30 fish in each. A single donor fish was able to transfer virus to recipient fish. However, unlike the A. salmonicida experiment, transmission was insufficient to initiate a full-scale infectious hematopoietic (IHN) epizootic. Estimated parameters for dynamics of infection were approximately half of the values for A. salmonicida (R₀=2.57,β=0.008 (individuals*day)⁻¹ and α=0.15). The models constructed for IHNV spread were used to simulate the results of density experiment. However, it was not possible to test the association between susceptible and infected classes due to inadequate number of infected fish. / Graduation date: 2001