Thesis (Ph.D.)--University of Western Australia, 2004.

Thesis (M.S.)--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Erysipelothrix rhusiopathiae é um importante patógeno em suinocultura e apesar do uso freqüente de vacinas contra o mesmo na maior parte das propriedades produtoras do país, a ocorrência de quadros clínicos da infecção tem sido amplamente observada e diagnosticada. Tendo em vista o ressurgimento deste agente como causa de prejuízos econômicos para a indústria suinícola nacional e seu potencial risco à saúde pública, este estudo teve como objetivo caracterizar 151 amostras de Erysipelothrix spp. isoladas de suínos nos útlimos 30 anos por meio de sorotipagem, determinação da susceptibilidade antimicrobiana, AFLP e PFGE. Dentre os 151 isolados, 139 foram classificados em 18 sorotipos diferentes (1a, 1b, 2a, 2b, 4, 5, 6, 7, 8, 10, 11, 12, 15, 17, 19, 21, 24 e 25), sendo que o sorotipo 2b foi o mais freqüente. Os perfis de susceptibilidade antimicrobiana foram muito semelhantes entre os isolados, o que impossibilitou a subtipagem dos isolados de Erysipelothrix spp. pelos testes de sensibilidade. Dentre os primers testados no AFLP, o HI-G foi o mais adequado à tipagem molecular de Erysipelothrix spp. Apesar do AFLP/HI-G e da PFGE apresentarem o mesmo índice discriminatório (0,98), a PFGE apresentou melhor relação com os dados epidemiológicos que o AFLP/HI-G, tendo em conta os agrupamentos por ela gerados. Independente da técnica molecular empregada, não foi observado a discriminação entre isolados recentes e históricos, bem como um padrão epidemiológico fixo de agrupamento dos mesmos. Contudo, o AFLP/HI-G pode ser uma alternativa interessante para diferenciar as espécies de Erysipelothrix, assim como a PFGE tem grande potencial para agrupar isolados deste gênero de acordo com os sorotipos. / Erysipelothrix rhusiopathiae is an important pathogen in swine production and even with the frequent use of vaccines against it in most of Brazilian pig farms, the occurrence of clinical manifestations of its infection has been widely observed and diagnosed. Given the resurgence of this agent as a cause of economic losses to the national pig industry and its potential risk to public health, this study aimed to characterize 151 samples of Erysipelothrix spp. isolated from swine in last 30 years by serotyping, determination of antimicrobial susceptibility, AFLP and PFGE. Among the 151 isolates, 139 were classified in 18 different serotypes (1a, 1b, 2a, 2b, 4, 5, 6, 7, 8, 10, 11, 12, 15, 17, 19, 21, 24 and 25) and serotype 2b was the most frequent. The susceptibility profiles were very similar among the isolates, which precluded the subtyping of Erysipelothrix spp. isolates by sensitivity tests. Among the primers tested in AFLP, the HI-G was the most suitable for molecular typing of Erysipelothrix spp. Despite AFLP/HI-G and PFGE provided the same discriminatory index (0.98), PFGE presented better relationship with epidemiological data than AFLP/HI-G, given the types of groups generated by it. Regardless of the molecular technique employed, there was no discrimination between recent and historical isolates as well as a fixed epidemiological pattern of grouping them. Nevertheless AFLP/HI-G could be an interesting alternative for Erysipelothrix species discrimination, even as PFGE has a good potential to diferenciate this genus according to serotypes.

Erysipelothrix rhusiopathiae é um importante patógeno em suinocultura e apesar do uso freqüente de vacinas contra o mesmo na maior parte das propriedades produtoras do país, a ocorrência de quadros clínicos da infecção tem sido amplamente observada e diagnosticada. Tendo em vista o ressurgimento deste agente como causa de prejuízos econômicos para a indústria suinícola nacional e seu potencial risco à saúde pública, este estudo teve como objetivo caracterizar 151 amostras de Erysipelothrix spp. isoladas de suínos nos útlimos 30 anos por meio de sorotipagem, determinação da susceptibilidade antimicrobiana, AFLP e PFGE. Dentre os 151 isolados, 139 foram classificados em 18 sorotipos diferentes (1a, 1b, 2a, 2b, 4, 5, 6, 7, 8, 10, 11, 12, 15, 17, 19, 21, 24 e 25), sendo que o sorotipo 2b foi o mais freqüente. Os perfis de susceptibilidade antimicrobiana foram muito semelhantes entre os isolados, o que impossibilitou a subtipagem dos isolados de Erysipelothrix spp. pelos testes de sensibilidade. Dentre os primers testados no AFLP, o HI-G foi o mais adequado à tipagem molecular de Erysipelothrix spp. Apesar do AFLP/HI-G e da PFGE apresentarem o mesmo índice discriminatório (0,98), a PFGE apresentou melhor relação com os dados epidemiológicos que o AFLP/HI-G, tendo em conta os agrupamentos por ela gerados. Independente da técnica molecular empregada, não foi observado a discriminação entre isolados recentes e históricos, bem como um padrão epidemiológico fixo de agrupamento dos mesmos. Contudo, o AFLP/HI-G pode ser uma alternativa interessante para diferenciar as espécies de Erysipelothrix, assim como a PFGE tem grande potencial para agrupar isolados deste gênero de acordo com os sorotipos. / Erysipelothrix rhusiopathiae is an important pathogen in swine production and even with the frequent use of vaccines against it in most of Brazilian pig farms, the occurrence of clinical manifestations of its infection has been widely observed and diagnosed. Given the resurgence of this agent as a cause of economic losses to the national pig industry and its potential risk to public health, this study aimed to characterize 151 samples of Erysipelothrix spp. isolated from swine in last 30 years by serotyping, determination of antimicrobial susceptibility, AFLP and PFGE. Among the 151 isolates, 139 were classified in 18 different serotypes (1a, 1b, 2a, 2b, 4, 5, 6, 7, 8, 10, 11, 12, 15, 17, 19, 21, 24 and 25) and serotype 2b was the most frequent. The susceptibility profiles were very similar among the isolates, which precluded the subtyping of Erysipelothrix spp. isolates by sensitivity tests. Among the primers tested in AFLP, the HI-G was the most suitable for molecular typing of Erysipelothrix spp. Despite AFLP/HI-G and PFGE provided the same discriminatory index (0.98), PFGE presented better relationship with epidemiological data than AFLP/HI-G, given the types of groups generated by it. Regardless of the molecular technique employed, there was no discrimination between recent and historical isolates as well as a fixed epidemiological pattern of grouping them. Nevertheless AFLP/HI-G could be an interesting alternative for Erysipelothrix species discrimination, even as PFGE has a good potential to diferenciate this genus according to serotypes.

Erysipelothrix rhusiopathiae, a Gram-positive bacillus, has long been an important pathogen in veterinary medicine as well as a cause of serious disease in humans. Infections caused by this organism have economic impact on animal industries, causing erysipelas in swine and morbidities in other farmed animals. Human infections are commonly erysipeloid (skin cellulitis) and occasionally septicaemia or endocarditis. Little is known of the diagnosis, epidemiology and pathogenesis of such infections in Western Australia. The aims of this thesis were to establish new diagnostic techniques for the detection and recovery of E. rhusiopathiae, to describe the epidemiology of Erysipelothrix infection in Western Australia in humans and animals, and to characterize virulence-associated characteristics, especially focusing on the neuraminidase produced by the organism. A protocol using 48 h Brain Heart Infusion enrichment followed by subculture to selective agar containing antibiotics achieved the highest recovery rate of 37% in a seafood survey. Twentyone isolates of Erysipelothrix spp., of which 19 were identified as E. rhusiopathiae, were obtained. Two published PCR assays for differentiating E. rhusiopathiae and other Erysipelothrix species were evaluated and the best PCR detection rate achieved was 67% following selective enrichment. The PCR method was 50% more sensitive than the culture method. Epidemiological surveys using the above methods showed that E. rhusiopathiae infection is present in farmed animals in Western Australia. The PCR positive frequencies (3.3-3.7%) and isolate recovery rate (2.8-3.3%) in samples from pig and sheep abattoirs and carcass washings indicate a potential threat to the economy of the farmed animal industry as well as a public health concern with the occurrence of E. rhusiopathiae in meat for consumption. Positive PCR results (1.1%) from human skin swabs of patients with cellulitis and wounds may suggest the existence of Erysipelothrix colonization in the general population. Genetic relatedness of 92 isolates of Erysipelothrix species from various sources was analyzed and a total of 64 distinct PFGE patterns identified. Isolates were further classified into 20 clonal groups based on pattern similarities, and most E. rhusiopathiae were clustered into six groups. A few patterns of other Erysipelothrix species were clustered into separate groups from E. rhusiopathiae but shared greater than 70% similarity with E. rhusiopathiae. The genetic relatedness of colonial variants was well demonstrated using this method. PFGE typing promises to be a useful tool for epidemiological and taxonomic studies of Erysipelothrix. Several virulence-associated factors were characterized in 86 isolates of Erysipelothrix spp. A rapid and sensitive peanut lectin hemagglutination assay for neuraminidase was developed and the influence of media, incubation conditions and pH on the production of the enzyme was investigated. All 61 isolates of E. rhusiopathiae produced neuraminidase in cooked meat broth with titres between 1:10 and 1:320, with no significant difference in titre among isolates from different sources. The enzyme activity was not detected in non-pathogenic Erysipelothrix spp. Capsule was produced by 78.7% of isolates of E. rhusiopathiae but not by other species, while both hyaluronidase and haemolysin were produced by non-pathogenic Erysipelothrix spp. It was concluded that neuraminidase and capsule are most likely to be virulence factors of E. rhusiopathiae. The gene encoding neuraminidase was cloned from the type strain E. rhusiopathiae ATCC 19414. The cloned fragment was a functional partial nanH gene with a mol% G+C of 39.7. The predicted amino acid sequence displayed homology with many microbial neuraminidases and contained conserved sequences found in most bacterial neuraminidases. Southern hybridization experiments demonstrated that the gene was present as a single copy on the bacterial genomic DNA. A neuraminidasenegative mutant vector was constructed by insertional inactivation using a tetM cassette. This has provided starting material for developing a neuraminidase-deficient E. rhusiopathiae mutant, which will permit the study of the role of neuraminidase in pathogenesis. Based on the cloned sequence, a sensitive neuraminidase-specific nested PCR technique was designed and optimized. The specificity was tested in 61 isolates of E. rhusiopathiae, 25 Erysipelothrix species, and 62 other species of neuraminidaseproducing and non-producing bacteria. All isolates of E. rhusiopathiae were PCR positive and all other bacteria were negative; thus this PCR is a highly specific method suitable for application in clinical investigations of Erysipelothrix infection. In conclusion, the present study has contributed new knowledge of the biology of Erysipelothrix spp. and current occurrence of Erysipelothrix infections in Western Australia, as well as to the understanding of pathogenesis of E. rhusiopathiae. Development of several new cultural and molecular approaches in combination with other established techniques will facilitate future studies of the epidemiology, taxonomy and pathogenesis of this bacterial species.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-28T13:10:47Z No. of bitstreams: 1 DissLC.pdf: 1362892 bytes, checksum: c909112bd0ccd7d43250543e0d7d4a5e (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-10T14:52:29Z (GMT) No. of bitstreams: 1 DissLC.pdf: 1362892 bytes, checksum: c909112bd0ccd7d43250543e0d7d4a5e (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-10T14:52:36Z (GMT) No. of bitstreams: 1 DissLC.pdf: 1362892 bytes, checksum: c909112bd0ccd7d43250543e0d7d4a5e (MD5) / Made available in DSpace on 2016-10-10T14:52:43Z (GMT). No. of bitstreams: 1 DissLC.pdf: 1362892 bytes, checksum: c909112bd0ccd7d43250543e0d7d4a5e (MD5) Previous issue date: 2015-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The swine erysipelas is a disease caused by the bacterium Erysipelothrix rhusiopathiae, globally distributed. The pig farming is expanding, and pork is the most consumed in the world. Large investments have been made to increase these herds, especially in the search for vaccines. The disease is currently prevented by vaccination of flocks, but the existing formulations (inactive or attenuated pathogen) can aggravate problems of arthritis in these animals. For the development of new vaccines, free of E. rhusiopathiae cells, the protein SpaA (Surface protective antigen A) appears as a major antigen in studies. We evaluate, in mice, the immune response and the efficiency of two formulations based on SpaA antigen, and compared the results obtained with a commercial vaccine prepared with inactivated cells of the pathogen. The formulations used were: a) living cells of recombinant attenuated Salmonella typhimurium - SL3261 expressing SpaA; b) SpaA purified protein and aluminum hydroxide (v/v). After immunization and challenge of the animals, we evaluated production of antibodies (ELISA) and the inflammatory cells profile systemic infection by E. rhusiopathiae. The results showed that the purified antigen can promote 50% protection (with an over-dose challenge 50xDL50) of a virulent E. rhusiopathiae. In the DL50 challenge, we analyze the cellular profile, antibody production, and interleukin dosage. The purified protein vaccine promoted negative modulation of the output inflammatory cells from bone marrow into the blood, compared to only infected group. There was a specific IgG production against rSpaA, and the most antigenic vaccine was the purified protein, compared to commercial vaccine and recombinant Salmonella vaccine. By analysis of interleukins (IL-4 and IL-12) and IgG1 and IgG2a subclasses, we found that vaccines stimulate both the Th1 response as Th2, being observed more likely to Th2 response. Thus, these data suggest that SpaA purified protein is capable of stimulating an immune response with protective character, reducing the risk of secondary impairments like those occurring with the use of inactivated vaccines to pathogens. / A erisipela suína é uma enfermidade causada pela bactéria Erysipelothrix rhusiopathiae, distribuída de forma global. A criação de suínos está em expansão, e a carne suína é a mais consumida no mundo. Grandes investimentos têm sido realizados para o aumento destes rebanhos, com destaque para a busca por vacinas. A doença é prevenida atualmente pela vacinação de parte dos rebanhos, porém as formulações existentes (patógeno inativado ou atenuado) podem agravar problemas de artrite nesses animais. Para as novas vacinas em desenvolvimento, livres das células de E. rhusiopathiae, a proteína SpaA (Surface protective antigen A) aparece como principal antígeno em estudo. Neste trabalho, avaliamos, em modelo murino, a resposta imunológica e a eficiência de duas formulações baseadas no antígeno SpaA, e comparamos os resultados obtidos com uma vacina comercial preparada com células inativadas do patógeno. As formulações usadas foram: a) células vivas de Salmonella typhimurium– SL3261 recombinante atenuada, expressando SpaA; b) proteína SpaA purificada + hidróxido de alumínio (v/v). Após imunização e desafio dos animais, foi avaliada a produção de anticorpos (método ELISA) e o perfil inflamatório frente à infecção por E. rhusiopathiae de forma sistêmica.Os resultados obtidos mostraram que o antígeno purificado foi capaz de promover 50 % de proteção (desafio com uma super-dose de 50xDL50) de uma cepa virulenta de E. rhusiopathiae. No desafio com a DL50, foi feita análise do perfil celular, da produção de anticorpos, além de dosagem de interleucinas. A vacina de proteína purificada promoveu modulação negativa da saída das células inflamatórias da medula óssea para o sangue, em relação ao grupo apenas infectado. Houve produção de IgG específicos contra rSpaA, sendo a vacina de proteína purificada mais antigênica quando comparada a vacina comercial e a de Salmonella recombinante. Pela análise de interleucinas (IL-4 e IL-12) e das subclasses IgG1 e IgG2a, observamos que as vacinas estimulam tanto a resposta Th1 quanto a Th2, sendo observada maior tendência de resposta Th2. Assim, esses dados sugerem que, apenas a proteína purificada SpaA é capaz de estimular uma resposta imune de caráter protetor, diminuindo o risco de comprometimentos secundários como os que ocorrem com a utilização de vacinas com patógenos apenas inativados.

Made available in DSpace on 2015-03-26T13:46:52Z (GMT). No. of bitstreams: 1 texto completo.pdf: 331526 bytes, checksum: 087586b326562ece474e6fe3fa8a0d49 (MD5) Previous issue date: 2004-08-31 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / Swine erysipelas, caused by Erysipelothrix rhusiopathiae, is responsible for enormous economic losses related to abortions and mainly to the chronic form of the disease, due to the costs of treatment, reduced growth rate and carcass´s quality. Although Erysipelothrix sp. is not a demanding organism, there are difficulties associated to its laboratorial identification. Lack of information about epidemiology of swine erysipelas in Brazil and the economical and sanitary importance of this disease reveal the necessity of isolation studies and characterization of the Erysipelothrix sp. isolates. The objectives of the present study were to verify the existence of health carriers pigs of E. rhusiopathiae in swine producing regions; to verify isolation rate of Erysipelothrix sp. strains from the tonsils of apparently normal swine by the methods crystal violet selective modified media (CV) and tryptose phosphate enrichment media (TP); to investigate the distribution of carriers pigs according to productive category (finishing pig and sow), animal localization (state of federation), isolation method (CV and TP), cellular morphology (smooth, smooth-intermediate, intermediate, intermediate-rough and rough forms) and Erysipelotrhix species (E. rhusiopathiae and E. tonsillarum). Tonsils from 398 finishing pigs, male and female, and 112 sows, obtained from 46 farms in 28 cities of Mato Grosso do Sul (MS), Goiás (GO), Paraná (PR), São Paulo (SP) and Minas Gerais (MG), were collected from slaughterhouses and were examined in the Laboratório de Microbiologia, Departamento de Veterinária, Universidade Federal de Viçosa MG. Obtained data were expressed in frequency and analized by Qui-square test, using Epi Info version 6.04b (WHO, 1997) and Bio Estat 2.0 (AYRES et al., 2002) programs, adopting significance level of 5%, with p value £ 0,05 considered significant. Of 510 apparently health slaughter pigs, 99 (19,41%) were detected as carriers of Erysipelothrix sp. The percentage of isolation by CV technique was 18,24% (93/510), while TP technique was 5,69% (29/510). There was no difference of tonsillar carriers of Erysipelothrix sp. according to the animal productive category (p > 0,05), suggesting that finishing pigs and sows may be potential source for infection to other animals in swine herds. The percentage of tonsillar carriers was 25,93% in GO, 23,08% in PR, 20,51% in MG, 14,67% in SP and 12,71% in MS, indicating that the presence of the organism is not a local phenomenon. It was observed mainly carriers pigs of only E. rhusiopathiae strains (75,76%), and it was demonstrated that slaughter pigs may be carriers of E. rhusiopathiae and E. tonsillarum simultaneously. In this study, the smooth form (53,4%) was predominant in samples of E. rhusiopathiae, followed by smooth-intermediate form (27,18%). Intermediate and intermediate-rough forms were observed with a low frequency (9,71%), while rough form was not identified in this report. / A erisipela suína, causada pela bactéria Erysipelothrix rhusiopathiae, apresenta relevância pelas perdas econômicas relacionadas com os abortamentos e, principalmente, com o quadro crônico da doença em cevados, devido aos custos com o tratamento, à redução da taxa de crescimento e à pior qualidade da carcaça na tipificação. Embora Erysipelothrix sp. não seja uma bactéria muito exigente, há dificuldades associadas a sua identificação laboratorial. A escassez de dados sobre a epidemiologia da doença no plantel brasileiro, somada à importância econômica e sanitária do patógeno, reforçam a necessidade da realização de pesquisas de isolamento e de caracterização das amostras de E. rhusiopathiae. Os objetivos deste estudo foram: verificar a existência de suínos portadores de E. rhusiopathiae em regiões produtoras de suínos no país; verificar a taxa de isolamento de amostras de Erysipelothrix sp. de tonsilas de suínos aparentemente sadios, utilizando-se o meio seletivo cristal violeta (CV) modificado e o meio de enriquecimento triptose fosfato (TP); verificar a distribuição dos animais portadores, segundo as variáveis categoria produtiva (cevado e matriz), origem dos animais (estado da federação), técnica de isolamento (CV e TP), morfologia celular (lisa, lisa à intermediária, intermediária, intermediária à rugosa e rugosa) e espécie de Erysipelothrix (E. rhusiopathiae e E. tonsillarum). As tonsilas de 398 cevados, de ambos os sexos, e de 112 porcas reprodutoras descartadas, oriundos de 46 propriedades em 28 municípios dos estados de Mato Grosso do Sul (MS), Goiás (GO), Paraná (PR), São Paulo (SP) e Minas Gerais (MG), foram coletadas em estabelecimento de carne e derivados e processadas no Laboratório de Microbiologia do Departamento de Veterinária da Universidade Federal de Viçosa - MG. Os dados obtidos foram expressos pela taxa de freqüência e avaliados pelo teste de Qui-quadrado (c2), através dos programas Epi Info versão 6.04b (WHO, 1997) e Bio Estat 2.0 (AYRES et al., 2002). Para todas as análises, o nível de significância adotado foi de 5% e um valor de p £ 0,05 foi considerado significativo. Dos 510 suínos aparentemente sadios pesquisados, 99 (19,41%) foram diagnosticados carreadores tonsilares de Erysipelothrix sp. A técnica CV diagnosticou 18,24% (93/510) de suínos portadores, enquanto que a TP diagnosticou 5,69% (29/510), havendo diferença estatisticamente significativa (p<0,01) entre as percentagens de cada técnica. Não se observou diferença estatística (p>0,05) quanto à freqüência de suínos carreadores de Erysipelothrix sp. segundo a categoria produtiva, ressaltando que tanto os cevados como as matrizes assumem o status de disseminadores do microrganismo na granja. A percentagem de suínos portadores foi de 25,93% em GO, 23,08% no PR, 20,51% em MG, 14,67% em SP e 12,71% em MS, indicando que a presença do Erysipelothrix sp. nas tonsilas de suínos aparentemente sadios não é um fenômeno local. Constatou-se maior percentagem (75,76%) de suínos carreadores exclusivamente de E. rhusiopathiae, e que os suínos podem ser portadores concomitantemente de E. rhusiopathiae e E. tonsillarum. Avaliando-se a morfologia celular das amostras de E. rhusiopathiae isoladas, a morfologia lisa (53,40%) foi a mais freqüente, seguida da forma lisa à intermediária (27,18%). As morfologias intermediária e intermediária à rugosa apresentaram as menores percentagens (9,71%), enquanto que a forma rugosa não foi identificada em nenhuma amostra.

Made available in DSpace on 2016-06-02T19:56:39Z (GMT). No. of bitstreams: 1 3049.pdf: 2440029 bytes, checksum: f8b9ee5d47547364d040e6797729060f (MD5) Previous issue date: 2010-03-19 / Universidade Federal de Sao Carlos / Pork is one of the most widely eaten meats in the world and pig farming is an economic activity booming in Brazil and the world. Several efforts have been made to develop more effective vaccines for major diseases that are affecting livestock such as swine erysipelas, caused by the bacterium Erysipelothrix rhusiopathiae. The currently available vaccines for the prevention of erysipelas are produced with culture broth of this microorganism inactivated or attenuated. The main antigenic agent identified is an protein fraction of 64-69 kDa, present in cell wall of bacteria and the supernatant of the culture. Given the accumulated knowledge of the studies conducted by Silva (2007), this study aimed to: i) study the conditions employed in the preparation of cell suspension for freezing and formation of culture stocks in crytubes and the stage of their activation; ii) studying the growth of E. rhusiopathiae, the formation of lactic acid and expression of antigen in culture media containing carbon sources alternative to glucose and in culture media containing nitrogen sources of plant origin; iii) to study the behavior of the microorganism in the new culture medium, animal-free, in a bioreactor. The studies for the improvement of the medium formulation were carried out in flasks incubated at static condition or under agitation of 200 rpm. The temperature was set at 37°C and the initial pH at 8,0 in all experiments. The studies in bioreactor were made using a 4.0 L stirred-tank bioreactor, with an agitation frequency kept between 100 and 700 rpm and air flow rate of 1.0 L/min. Samples of cell extracts made with choline chloride were analyzed by electrophoresis under denaturating conditions (SDS-PAGE) to evaluate the antigen expression. Studies of activation of the criotubes containing frozen cell suspensions led to the standardization of this step, with high reproducibility, and reduced activation time by 50%. The studies were grew with different carbon sources, showing that E. rhusiopathiae is able to assimilate galactose, lactose, and glucose. However, there was no assimilation of glycerol. The replacement of proteose peptone, a nitrogen source animal widely used in the cultivation of E. rhusiopathiae to produce bacterins, by Soytone, a soy peptone, animal-free, was a promising alternative for the production of the inactivated vaccine, helping to increase the specific growth rate and substrate conversion of cells in relation to values obtained in conventional medium. In batch cultivation performed in a bioreactor with medium containing glucose and Soytone, it was reached a biomass concentration of 10 g / L at 5 hours of cultivation. For the conventional medium, containing proteose peptone, the maximum cell concentration reported for the test batch in a bioreactor was approximately 2 g / L, which was reached after 7 hours of culture. Note also that a higher level of expression of antigenic protein in relation to those observed with peptone of animal origin was achieved in cultures performed with medium containing soytone.This result shows that could be incorporate the best practices of manufacturing practices for pharmaceutical and veterinary products, subject to the productivity of the process and with significant cost reduction. / A carne suína é a mais consumida no mundo e a suinocultura é uma atividade econômica em franca expansão no Brasil e no mundo. Diversos esforços vêm sendo realizados para o desenvolvimento de vacinas mais eficientes para as principais doenças que afetam os rebanhos, como a erisipela suína, causada pela bactéria Erysipelothrix rhusiopathiae. As vacinas disponíveis atualmente para a prevenção da erisipela são produzidas com o caldo de cultivo deste microrganismo inativado ou atenuado. O principal agente antigênico identificado é uma fração protéica de 64-69 kDa, presente tanto na parede celular da bactéria quanto no sobrenadante do cultivo. Diante do conhecimento acumulado ao longo dos estudos conduzidos por Silva (2007), o presente trabalho teve como objetivos: i) estudar as condições empregadas na preparação das suspensões celulares para armazenamento na forma de cultura estoque em criotubos assim como a etapa de ativação dos mesmos; ii) estudar o crescimento de E. rhusiopathiae, a formação de ácido lático e a expressão do antígeno SpaA em meios de cultivo contendo fontes de carbono alternativas à glicose e fontes de nitrogênio de origem vegetal; iii) estudar o comportamento do microrganismo no meio de cultura novo, livre de substratos de origem animal, em biorreator. Os experimentos foram conduzidos em câmara incubadora, em cultivos estáticos ou com agitação de 50 ou de 200 rpm. A temperatura utilizada foi de 37°C e o pH inicial foi de 8,0 em todos os ensaios realizados. Os estudos em biorreator foram realizados em biorreator de 5,0 L, com agitação entre 100 a 700 rpm e vazão de ar de 1,0 a 2 L/min. Amostras retiradas durante os cultivos foram empregadas para análise da densidade ótica (a 420 nm) e das concentrações de glicose, biomassa e metabólitos. A expressão do antígeno foi avaliada por eletroforese em condições desnaturantes (SDS-PAGE) a partir de extratos das células preparados com solução de cloreto de colina. Os estudos envolvendo a ativação dos criotubos contendo as suspensões celulares congeladas levaram à padronização desta etapa, com alta reprodutibilidade, e à diminuição do tempo de ativação em 50 %. Os cultivos realizados com diferentes fontes de carbono, mostraram que E. rhusiopathiae é capaz de assimilar galactose e lactose, além de glicose. No entanto, não foi verificada assimilação de glicerol. A substituição da proteose peptona, fonte de nitrogênio de origem animal amplamente utilizada nos cultivos de E. rhusiopathiae para produção de bacterinas, pela peptona de soja hidrolisada Soytone, de origem vegetal, mostrou-se um alternativa promissora para a produção da vacina de células inativadas, contribuindo para aumento da velocidade específica de crescimento e da conversão de substrato em células em relação aos valores obtidos no meio convencional. Em cultivo descontínuo realizado em biorreator de bancada com o meio contendo glicose e Soytone, foi alcançada uma concentração de biomassa de 10 g/L em 5 horas de cultivo. Para o meio convencional, contendo proteose peptona, a máxima concentração celular relatada para ensaio em batelada em biorreator de bancada foi aproximadamente 2 g/L, a qual foi atingida após 7 horas de cultivo. Destaca-se ainda que um nível superior de expressão da proteína antigênica em relação aos observados com a peptona de origem animal foi alcançado nos cultivos realizados com o meio contendo soytone. Esse resultado mostra ser possível incorporar as boas práticas de manufatura recomendadas para produtos farmacêuticos e veterinários, sem prejuízo à produtividade do processo e com significativa redução do custo do meio.

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Background: Infective endocarditis is a rare but severe condition associated with a high mortality rate in small animal patients. This condition is caused by a microbial (most often bacterial) infection of the valvular portion of the endocardium, from which proliferative and/or erosive lesions on the cardiac valves or immediately adjacent structures develop. The two most commonly affected cardiac valves are the aortic and mitral valves. Case presentation: We report the clinical case of a 4-year old male neutered Bull terrier, 27.6 kg, body condition score 4/9, that presented with a 3-months history of pyrexia and general weakness. The patient history also revealed a transient left hind limb lameness (grade 2/4), which coincided with the onset of clinical signs about 3 months before presentation. On physical examination, a left-sided systolic heart murmur (grade 3/6) with the same intensity at the left heart base and apex, and an irregularly irregular heart rhythm were noted. Electrocardiography showed ventricular premature complexes, and echocardiography revealed lesions consistent with endocarditis involving the aortic and mitral valve. Bacterial culture of blood yielded a positive result, and the organism isolated was identified as Erysipelothrix rhusiopathiae. The extended patient history revealed that the dog lived close to a farm housing pigs and other livestock. Conclusion: We report a rare case of the premortal diagnosis of infective bacterial endocarditis in a dog due to E. rhusiopathiae infection. Most reports about this condition are from necropsy series. This clinical case report emphasizes that E. rhusiopathiae infection and bacteremia should be considered as a differential diagnosis in dogs with suspected infective endocarditis, especially in dogs living in rural areas with access to livestock and particularly farm pigs. Also, particular emphasis should be placed on the zoonotic potential of this infectious disease.