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Reduction of milk production following acute bovine mastitis causes important economic losses. In this study, two experiments were conducted to asses the ability of different antioxidants to prevent neutrophil (PMN)-induced mammary damage in acute bovine mastitis. First, a co-culture model composed of bovine mammary epithelial cell line (MAC-T cells) and bovine PMN activated by phorbol myristate acetate was used. Activated PMN release reactive oxygen species that are cytotoxic for bovine epithelial cells. Addition of dimethylthiourea or bathocuproinic acid did not induce any protective effect. On the other hand, addition of catechin, deferoxamine or glutathione ethyl ester (GEE) significantly reduced PMN-induced cytotoxicity in a dose-dependent manner as demonstrated by lower levels of released lactate dehydrogenase (LDH). The second experiment was undertaken with the last three antioxidants to evaluate their protective effects in vivo. A model of LPS-induced mastitis on dairy cows was used. The extent of cell damages was evaluated by measuring quarter milk levels of LDH and 4-methylumbelliferyl N-acetyl beta-D-glucosaminidase ( NAGase) at varying intervals before and after intramammary infusions of LPS, with or without antioxidants. Milk levels of haptoglobin and bovine serum albumin were also analysed. Catechin and GEE did not induce any protective effect whereas infusions of deferoxamine, a chelator of iron, decreased milk levels of LDH, NAGase and haptoglobin hence suggesting a protective effect against PMN-induced damage. Deferoxamine did not interfere with PMN migration into the mammary gland. Additionally, deferoxamine inhibited bacterial growth in vitro but did not affect PMN's ability to phagocytize live Escherichia coli. Overall, our results suggest that local infusion of deferoxamine may be an effective tool to protect mammary tissue against PMN-induced oxidative stress during bovine mastitis.

Orientador: Vera Lucia Mores Rall / Coorientador: João Pessoa Araujo junior / Banca: Ary Fernandes Junior / Banca: Carlos Henrique Camargo / Banca: José Paes de Almeida Nogueira / Banca: Lina Casale Aragon-Alegro / Resumo: Staphylococcus sp é agente comum da mastite bovina, causando grandes perdas econômicas na pecuária brasileira. Esse micro-organismo possui fatores de virulência bastante conhecidos como a produção de hemolisinas, leucotoxinas e superantígenos como a toxina do síndrome do choque tóxico e enterotoxinas. Além disso, várias espécies de Staphylococcus podem adquirir genes de resistência aos antibióticos β lactâmicos. O objetivo do estudo foi caracterizar molecularmente isolados de Staphylococcus sp provenientes de leite de vacas com mastite clinica e subclínica de várias regiões do estado de São Paulo. Foram realizadas coletas de leite de vacas com mastite clinica e subclínica de diferentes fazendas no estado de São Paulo e realizados testes fenótipicos de resistência a antimicrobianos e de virulência (Toxina de Panton Valentine, sindrome do choque tóxico e toxinas esfoliativas), além de testes moleculares como Pulse Field Gel Eletrophoresis (PFGE), Multiloccus Sequence Typing (MLST) e Spa typing para comparação entre as cepas epidemiologicamente importantes e da tipagem do cromossomo cassette estafilocócico em cepas meticilina reistentes. As cepas resistentes a meticilina apresentaram amplo perfil de resistência e genes de resistência importantes e pouco relatados, sendo observados genes como fexA, lsaE, lnuB. Foram detectados dois novos spatyping (t10852 e t10856), bem como um novo alelo yqiL e um novo ST (2493). Os ECNs apresentaram resistências à maioria dos antibióticos estudados e foi observado a uma deleção no gene ermC, que codifica a resistência à eritromicina. / Abstract: Staphylococcus sp. is the common agent of bovine mastitis, causing big economic losses in Brazilian cattle. This micro-organism have virulence factors have been well known as the production of hemolysin, and leucotoxinas toxin superantigens such as toxic shock syndrome and enterotoxins. In addition, several Staphylococcus species can acquire antibiotic resistance genes β lactamics. The objective of the study is to characterize molecularly Staphylococcus sp. from milk of cows with subclinical mastitis in various regions of the state of São Paulo. Samples were coleted from milk of cows with subclinical and clinical mastitis from different farms in the state of São Paulo. Tests were performed phenotypic antimicrobial resistance and virulence (toxin Panton Valentine, toxic shock syndrome and exfoliative toxins), molecular tests as Eletrophoresis Pulse Field Gel Electrophoresis (PFGE), Multiloccus Sequence Typing (MLST) and spa typing for comparison between epidemiologically important strains, as well as the typing of strains in staphylococcal cassette chromosome methicillin reistentes. Methicillin-resistant strains showed broad resistance profile and resistance genes important and underreported were detected as fexA, lsaE, lnuB. Two new spatyping (t10852 and t10856) were detected as well as a new allele yqiL and a new ST (2493). The ECN showed resistance to most antibiotics and was observed the deletion in ermC gene encoding resistance to erythromycin. / Doutor

Bovine babesiosis is one of the common, economically important tick-borne infectious diseases of cattle. Clinical cases suspected to be babesiosis are frequently observed in the study area. Yet to date, no studies have been done in the farming areas of the north central of Namibia to establish the prevalence of the disease. The objectives of the present study were to determine the sero-prevalence of different Babesia species in Sanga cattle; determine the most prevalent Babesia species and the spatial distribution for two Babesia species in the study area. A total of 392 cattle were randomly sampled and bled to collect blood at various crush pens in all constituencies of the region. This was done during the annual vaccination campaign against lung sickness. The IFA (Indirect Fluorescent Antibody) a method known to have a sensitivity of 95% and specificity of 99%, was used to analyse the samples for Babesia antibodies. The most prevalent species was Babesia bigemina with an estimated prevalence of 36.5%, followed by Babesia bovis at 16.6%. Mixed infections were estimated to be 13.2%. The disease was found to be prevalent throughout the region with no significance association between infection as the dependent variable and independent variables like sex, age and place. The parasite was widely but not uniformly distributed in the study area. There is a need for more farmer education and awareness. The region proved to be endemically unstable for babesiosis, a vaccination protocol to establish good herd immunity is necessary to improve production. Similar studies in different parts of Namibia be performed and that efforts to prepare a local vaccine. Agricultural regulations should also include the removal of old animals to help improve productivity and farmers output. Further research should investigate and map out the prevalence of Babesia parasites and other heamoparasites in each region of Namibia. This information can also contribute towards the development of future interventions and management strategies in animal health / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)

Made available in DSpace on 2015-05-14T16:53:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-12-05Bitstream added on 2015-05-14T16:59:06Z : No. of bitstreams: 1 000826915_20151206.pdf: 375653 bytes, checksum: adf2f78838ae81a4890f0a8019e9a279 (MD5) Bitstreams deleted on 2015-12-07T09:44:40Z: 000826915_20151206.pdf,. Added 1 bitstream(s) on 2015-12-07T09:45:18Z : No. of bitstreams: 1 000826915.pdf: 1970838 bytes, checksum: 21816dd741b5f8f0d7c95dc3e252725a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Rede Nanobiotec / A cisticercose bovina é uma zoonose cosmopolita e presente nos rebanhos bovinos de corte no Brasil, que ocorre em países em desenvolvimento, onde a infraestrutura sanitária inadequada e as más práticas na criação de gado permitem a contaminação de pastagem e água com fezes humanas contendo ovos do parasita. Os prejuízos financeiros decorrem da condenação ou tratamento (salga ou da congelação) das carcaças infectadas, dependendo da intensidade da infecção. O diagnóstico da cisticercose bovina é realizado durante o abate, pela inspeção das carcaças e realização de cortes em locais de predileção do parasita como a língua, masseter, coração e diafragma. Assim, a fim de promover o diagnóstico ante-mortem e permitir o tratamento adequado de animais infectados, muitos estudos foram realizados utilizando-se técnicas de detecção de anticorpos ou antígenos em amostras de soro bovino. O teste ELISA baseado em anticorpos monoclonais (MAbs) para a detecção de antígeno circulante (Ag-ELISA) tem sido estudado, mas apresenta baixa sensibilidade em animais com infecção leve, e permite a sua realização apenas em laboratórios bem equipados. O uso de biossensores em medicina tem crescido nos últimos anos, permitindo a detecção e quantificação de metabólitos, bem como o uso de diversos biopolímeros como matriz de imobilização como quitosana e fibroína da seda. Imunossensores são biossensores cuja resposta bioquímica relaciona-se à interação antígeno-anticorpo, que podem ser utilizados para detectar anticorpos ou antígenos, tendo sido utilizados no diagnóstico de enfermidades. Nesta pesquisa, desenvolveu-se o primeiro imunossensor para o diagnóstico da cisticercose bovina, com filmes produzidos camada por camada (LbL) contendo um MAb dirigido contra antígeno bruto de metacestódeos de T. saginata (TAEB) e fibroína de seda (SF), imobilizados, que mostrou-se promissor ... / Bovine cysticercosis is a cosmopolitan zoonosis and very widespread in the Brazilian beef cattle. Cysticercosis usually occurs in developing countries, where poor sanitation and bad raising cattle practices allows the contamination of the pasture and water with human feces containing eggs. The financial losses are due to condemnation or treatment (salting or freezing) of infected carcasses, depending on the intensity of infection. Diagnosis of bovine cysticercosis is routinely done during slaughter by meat inspection of carcasses and incisions in predicted sites of muscles such as tongue, masseter, heart and diaphragm. Thus, in order to promote the ante-mortem diagnosis and allow appropriate treatment of infected animals, many studies have been performed using techniques to detect antibodies or antigens in bovine serum. ELISA using monoclonal antibodies (MAbs) for the detection of circulating antigen (Ag-ELISA) has been studied, but presents low sensitivity in animals with low parasite burden, and allows its realization only in well-equipped laboratories. The use of biosensors in medicine has grown in recent years, allowing detection and quantification of numerous metabolites, such as immobilization matrix having the most diverse biopolymers such as chitosan and silk fibroin. Immunosensors are biosensors which biochemical response is related to antigen-antibody interaction and can be used to detect antibodies or antigens, and has been tested for diseases diagnosis. In this research, we developed the first immunosensor for bovine cysticercosis diagnosis, produced with layer-by-layer (LbL) films containing a monoclonal antibody against crude Taenia saginata metacestode antigens (TAEB) and silk fibroin (SF) immobilized. Immunosensor showed to be a promising tool for further application in the ante-mortem bovine cysticercosis diagnosis

Orientador: Germano Francisco Biondi / Coorientador: Elenice Deffune / Banca: Cáris Maroni Nunes / Banca: Márjorie de Assis Golim / Banca: Marli Leite de Moraes / Banca: Milton Hissashi Yamamura / Resumo: A cisticercose bovina é uma zoonose cosmopolita e presente nos rebanhos bovinos de corte no Brasil, que ocorre em países em desenvolvimento, onde a infraestrutura sanitária inadequada e as más práticas na criação de gado permitem a contaminação de pastagem e água com fezes humanas contendo ovos do parasita. Os prejuízos financeiros decorrem da condenação ou tratamento (salga ou da congelação) das carcaças infectadas, dependendo da intensidade da infecção. O diagnóstico da cisticercose bovina é realizado durante o abate, pela inspeção das carcaças e realização de cortes em locais de predileção do parasita como a língua, masseter, coração e diafragma. Assim, a fim de promover o diagnóstico ante-mortem e permitir o tratamento adequado de animais infectados, muitos estudos foram realizados utilizando-se técnicas de detecção de anticorpos ou antígenos em amostras de soro bovino. O teste ELISA baseado em anticorpos monoclonais (MAbs) para a detecção de antígeno circulante (Ag-ELISA) tem sido estudado, mas apresenta baixa sensibilidade em animais com infecção leve, e permite a sua realização apenas em laboratórios bem equipados. O uso de biossensores em medicina tem crescido nos últimos anos, permitindo a detecção e quantificação de metabólitos, bem como o uso de diversos biopolímeros como matriz de imobilização como quitosana e fibroína da seda. Imunossensores são biossensores cuja resposta bioquímica relaciona-se à interação antígeno-anticorpo, que podem ser utilizados para detectar anticorpos ou antígenos, tendo sido utilizados no diagnóstico de enfermidades. Nesta pesquisa, desenvolveu-se o primeiro imunossensor para o diagnóstico da cisticercose bovina, com filmes produzidos camada por camada (LbL) contendo um MAb dirigido contra antígeno bruto de metacestódeos de T. saginata (TAEB) e fibroína de seda (SF), imobilizados, que mostrou-se promissor ... / Abstract: Bovine cysticercosis is a cosmopolitan zoonosis and very widespread in the Brazilian beef cattle. Cysticercosis usually occurs in developing countries, where poor sanitation and bad raising cattle practices allows the contamination of the pasture and water with human feces containing eggs. The financial losses are due to condemnation or treatment (salting or freezing) of infected carcasses, depending on the intensity of infection. Diagnosis of bovine cysticercosis is routinely done during slaughter by meat inspection of carcasses and incisions in predicted sites of muscles such as tongue, masseter, heart and diaphragm. Thus, in order to promote the ante-mortem diagnosis and allow appropriate treatment of infected animals, many studies have been performed using techniques to detect antibodies or antigens in bovine serum. ELISA using monoclonal antibodies (MAbs) for the detection of circulating antigen (Ag-ELISA) has been studied, but presents low sensitivity in animals with low parasite burden, and allows its realization only in well-equipped laboratories. The use of biosensors in medicine has grown in recent years, allowing detection and quantification of numerous metabolites, such as immobilization matrix having the most diverse biopolymers such as chitosan and silk fibroin. Immunosensors are biosensors which biochemical response is related to antigen-antibody interaction and can be used to detect antibodies or antigens, and has been tested for diseases diagnosis. In this research, we developed the first immunosensor for bovine cysticercosis diagnosis, produced with layer-by-layer (LbL) films containing a monoclonal antibody against crude Taenia saginata metacestode antigens (TAEB) and silk fibroin (SF) immobilized. Immunosensor showed to be a promising tool for further application in the ante-mortem bovine cysticercosis diagnosis / Doutor

No description available.