Call number: LD2668 .T4 1986 H87 / Master of Science / Clinical Sciences

Infections caused by resistant pathogens fail to respond to treatment, resulting in increased costs due to prolonged illness and hospitalization. Determining the extent of resistance in animal populations is thus of great importance to public health. In this work, we first showed that asymptomatic populations of Salmonella in pigs present greater genotypic and phenotypic diversity than disease-associated populations. Second, we identified a clonal population structure associated with asymptomatic Salmonella found in the Canadian swine industry and we confirmed that food-producing pigs are a significant reservoir of Salmonella enterica, more particularly the clinically important serotype Typhimurium DT104. Finally, we identified the possible independent evolution of multidrug-resistance in serotypes Typhimurium, Derby and Heidelberg. Our work on asymptomatic Salmonella enterica stresses the importance of linking ecology and evolutionary biology to public health in order to understand and predict the response of pathogenic bacteria to selective pressure imposed by host immunity, whether naturally or artificially induced.

Made available in DSpace on 2014-06-11T19:31:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-16Bitstream added on 2014-06-13T20:01:47Z : No. of bitstreams: 1 masson_gcih_dr_jabo.pdf: 739097 bytes, checksum: 2fef2cb4d684c81bde182928eafa28f3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / S. aureus é responsabilizado por diversos problemas clínicos em suinocultura e em humanos. Estudos epidemiológicos comprovam o potencial deste microrganismo em adquirir resistência a antibióticos. Atualmente estirpes resistentes a meticilina (MRSA), responsabilizados por casos de infecções nosocomiais, são as mais estudadas uma vez que o MRSA encontra-se disseminado em ambientes extra-hospitalares e frenquentemente tem sido isolado de vários animais domésticos inclusive suínos. O objetivo desde trabalho foi determinar a presença de S. aureus em granjas de suínos, identificar a ocorrência dos genes mecA, icaA e icaD e o perfil de resistência a antimicrobianos. Ao todo foram colhidas 458 amostras de cinco granjas e dois frigoríficos. As amostras foram semeadas em ágar Braid - Parker e ágar sangue seguido de provas bioquímicas. As amostras sugestivas, foram submetidas a PCR para confirmação de espécie, detecção do gene coa, mecA para avaliar a resistência a meticilina além dos genes de virulência icaA e icaD que expressam capacidade para formação de biofilmes. Na sequência, realizou-se o antibiograma para a avaliação de 11 antimicrobianos. Ao todo foram identificados 81 (79%) S. aureus isolados de todas as granjas e frigoríficos incluindo, três amostras isoladas de funcionários das granjas. Nenhuma amostra foi positiva para o gene mecA. Em relação aos genes icaA e icaD, observou predomínio do gene icaD e que 41% das amostras foram positivas para os dois genes. O antibiograma demonstrou grande resistência às penicilinas e tetraciclinas, além de grande quantidade de S aureus multirresistentes / Staphylococcus aureus are involved in a wide range of clinical problems to swine industry as son in humans. Epidemiological researchs prove his potential to acquire resistantence to antibiotics. Nowadays, methicillin-resistant S. aureus (MRSA) are responsabilized for nosocomial infections and many studies are done because MRSA are spread to extra hospitalar enrivonment and frequentely isolated from domestic animals including pigs. The aim of this study was to determine the presence o S. aureus at swine farms and identify the mecA, icaA and icaD genes and the resistant proflife to antibiotics. Overal, 458 swabs were taked from five pigeris and two slautherhouses. All the samples were placed on Braid – Parker and blood agar follow by biochemical analyses. The suspect colonies were submitted to PCR to confirm the S. aureus species, by the detection of the coa gene, mecA to avaible meticillin-resistant as son to the virulence gens icaA and icaD that can determine slime production. Antibiogram were done to evaluate the response to 11 antibiotics. All pigeris and slautherhouse were positive and 81 (79%) samples were S. aureus positive including three isolates from pigs employeers. The mecA gene was not detected. The icaD gene was most frequent and 41% were positive to both genes. The antibiogram show a lot of samples penicillin and tetraciclin resistant. Most of the samples were multirestant

Orientador: Luiz Fernando de Oliveira e Silva Carvalho / Banca: Everlon Cid Rigobelo / Banca: Aníbal de Sant'Anna Moretti / Banca: Luiz Carlos Marques / Banca: Mario Roberto Hatayde / Resumo: S. aureus é responsabilizado por diversos problemas clínicos em suinocultura e em humanos. Estudos epidemiológicos comprovam o potencial deste microrganismo em adquirir resistência a antibióticos. Atualmente estirpes resistentes a meticilina (MRSA), responsabilizados por casos de infecções nosocomiais, são as mais estudadas uma vez que o MRSA encontra-se disseminado em ambientes extra-hospitalares e frenquentemente tem sido isolado de vários animais domésticos inclusive suínos. O objetivo desde trabalho foi determinar a presença de S. aureus em granjas de suínos, identificar a ocorrência dos genes mecA, icaA e icaD e o perfil de resistência a antimicrobianos. Ao todo foram colhidas 458 amostras de cinco granjas e dois frigoríficos. As amostras foram semeadas em ágar Braid - Parker e ágar sangue seguido de provas bioquímicas. As amostras sugestivas, foram submetidas a PCR para confirmação de espécie, detecção do gene coa, mecA para avaliar a resistência a meticilina além dos genes de virulência icaA e icaD que expressam capacidade para formação de biofilmes. Na sequência, realizou-se o antibiograma para a avaliação de 11 antimicrobianos. Ao todo foram identificados 81 (79%) S. aureus isolados de todas as granjas e frigoríficos incluindo, três amostras isoladas de funcionários das granjas. Nenhuma amostra foi positiva para o gene mecA. Em relação aos genes icaA e icaD, observou predomínio do gene icaD e que 41% das amostras foram positivas para os dois genes. O antibiograma demonstrou grande resistência às penicilinas e tetraciclinas, além de grande quantidade de S aureus multirresistentes / Abstract: Staphylococcus aureus are involved in a wide range of clinical problems to swine industry as son in humans. Epidemiological researchs prove his potential to acquire resistantence to antibiotics. Nowadays, methicillin-resistant S. aureus (MRSA) are responsabilized for nosocomial infections and many studies are done because MRSA are spread to extra hospitalar enrivonment and frequentely isolated from domestic animals including pigs. The aim of this study was to determine the presence o S. aureus at swine farms and identify the mecA, icaA and icaD genes and the resistant proflife to antibiotics. Overal, 458 swabs were taked from five pigeris and two slautherhouses. All the samples were placed on Braid - Parker and blood agar follow by biochemical analyses. The suspect colonies were submitted to PCR to confirm the S. aureus species, by the detection of the coa gene, mecA to avaible meticillin-resistant as son to the virulence gens icaA and icaD that can determine slime production. Antibiogram were done to evaluate the response to 11 antibiotics. All pigeris and slautherhouse were positive and 81 (79%) samples were S. aureus positive including three isolates from pigs employeers. The mecA gene was not detected. The icaD gene was most frequent and 41% were positive to both genes. The antibiogram show a lot of samples penicillin and tetraciclin resistant. Most of the samples were multirestant / Doutor

Made available in DSpace on 2016-12-08T16:24:23Z (GMT). No. of bitstreams: 1 PGCV06MA010.pdf: 5309258 bytes, checksum: 0c98675b5eb134038631461c4ac02a50 (MD5) Previous issue date: 2006-03-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Postweaning multisystemic wasting syndrome (PMWS) is a multifactorial disease caused by a Porcine Circovirus Type 2 (PCV-2). It is clinically characterized by wasting, enlargement of lymph nodes, pallor, jaundice, and respiratory and digestive signs. The lesions affect mainly lymphoid tissues, lungs, kidneys and liver. Pathological findings consist of lymphohistiocytic infiltration of various organs and depletion of lymphoid follicles. However, to establish the conclusive diagnosis of PMWS, it is necessary the association of clinical signs, gross and microscopic lesions, besides the evidence of the antigen or viral DNA. Thus, the aim of this work was to establish two techniques of diagnosis: immunocitochemistry (ICC) in two cell lines (ST and VERO), using two types of primary antibodies against PCV-2 (a polyclonal produced in rabbit and a polyclonal produced in pig), to determine antibodies against PCV-2 in swine serum, and immunohistochemistry (IHC) in various parraffined swine tissues (lymph node, lung, liver, thymus, kidney and intestine), using two types of primary antibodies (a monoclonal produced in mouse and a polyclonal produced in rabbit) to show the viral antigen. In ICC, both cells cultures were susceptible to infection, where the antigen could be detected in the nucleum as much as in cytoplasm of the cells, with both primary antibodies. The IHC was established in the different tissues with both antibodies, where the antigen was verified mainly in macrophages, histiocytes and others inflammatory cells. Intending to verify the transmission of PCV-2 by semen and its infection power to the sow and to the piglets, 20 negative sows to PCV-2 were inseminated, 10 with a negative boar semen and 10 sows with a positive boar semen. After the insemination, the 20 sows were clinically attended and blood was collected to PCV-2 DNA investigation by nested-PCR. Based on the results, 4 sows between the 20 were selected (1 sow was serum negative inseminated with a negative semen, 2 sows were serum negative inseminated with a positive semen and 1 sow was serum negative inseminated with a positive semen, but serum converted around the 30 days of pregnancy). After the parturition, 12 male piglets, 3 of each sow, were selected and isolated. Samples of semen and serum were collected to PCV-2 DNA investigation by nested-PCR. Intending to verify which organs shelter the PCV-2, the piglets were submitted to euthanasia around 9 months of age, and samples of lymphoid, systemic and reproductive organs were collected to investigation by nested-PCR, histopathology (HE) and IHC. Evaluating the serum by ICC, all 12 piglets serum converted (4 were strongly positive, 3 were moderate positive and 5 were weakly positive). Evaluating the samples by nested-PCR, various tissues were positive in 10 of 12 piglets. Evaluating the same samples by IHQ, various samples were positive in 8 of 12 piglets. In general, the results had, in different samples, in the 4 tests (ICC, nested-PCR, HE and IHC) completed themselves. Thus, these results show the probable PCV-2 semen transmission to the piglets and also the infectious potential among pigs / A Síndrome Multissistêmica do Definhamento do Suíno (SMDS) é uma doença multifatorial, causada pelo Circovirus Suíno Tipo 2 (PCV-2). Clinicamente está caracterizada por definhamento, aumento de tamanho dos linfonodos, palidez e/ou icterícia e sinais digestivos e respiratórios. As lesões afetam principalmente tecidos linfóides, pulmão, rim e fígado. Os achados microscópicos consistem principalmente em infiltração linfo-histiocitária em vários órgãos e depleção dos folículos linfóides. Entretanto, para estabelecer o diagnóstico conclusivo da SMDS, é necessário associar sinais clínicos, lesões macroscópicas e microscópicas, além da demonstração do antígeno ou DNA viral. Assim, o objetivo deste trabalho foi padronizar duas técnicas de diagnóstico: imunocitoquímica (ICQ) em duas linhagens celulares (ST e VERO), utilizando dois tipos de anticorpos primários anti PCV-2 (policlonal produzido em coelho e policlonal produzido em suíno) para determinação de anticorpos anti PCV-2 em soro suíno e, imunohistoquímica (IHQ) em diversos tecidos parafinizados de suínos (linfonodo, pulmão, fígado, timo, rim e intestino), utilizando dois tipos de anticorpos primários (monoclonal produzido em camundongo e policlonal produzido em coelho) para demonstração do antígeno viral. Na ICQ, ambos cultivos celulares foram suscetíveis à infecção, podendo-se detectar o antígeno tanto no núcleo quanto no citoplasma das células, com os dois anticorpos primários. A IHQ foi padronizada nos diversos tecidos com os dois anticorpos, sendo que o antígeno foi verificado principalmente em macrófagos, histiócitos e outras células inflamatórias. Com o objetivo de verificar a transmissão via sêmen de PCV-2 e sua capacidade infecciosa para a fêmea e para a progênie, 20 fêmeas negativas para PCV-2 foram inseminadas, 10 com sêmen de macho negativo e 10 com sêmen de macho positivo. Após a inseminação, as 20 fêmeas foram acompanhadas clinicamente e foi coletado sangue para pesquisa de DNA de PCV-2 por nested-PCR . Baseado no resultado, 4 fêmeas das 20 foram selecionadas (1 fêmea soronegativa inseminada com sêmen negativo, 2 fêmeas soronegativas inseminadas com sêmen positivo e 1 fêmea soronegativa inseminada com sêmen positivo, mas que soroconverteu ao redor dos 30 dias de gestação). Após o parto, 12 leitões machos, 3 de cada fêmea, foram selecionados e mantidos em isolamento. Amostras de sêmen e soro foram coletadas para pesquisa de DNA de PCV-2 por nested-PCR . Para verificar quais órgãos abrigam o PCV-2, os leitões sofreram eutanásia ao redor dos nove meses de idade, e amostras de órgãos linfóides, sistêmicos e reprodutivos foram coletadas para avaliação por nested-PCR , histopatologia (HE) e IHQ. Ao avaliar o soro por ICQ, todos os 12 leitões soroconverteram (4 foram fortemente positivos, 3 moderadamente positivos e 5 fracamente positivos). Ao avaliar as amostras por nested-PCR , vários tecidos foram positivos em 10 dos 12 suínos. Ao avaliar as mesmas amostras por IHQ, várias foram positivas em 8 dos 12 suínos. No geral, os resultados obtidos nas diferentes amostras nos 4 testes (ICQ, nested-PCR , HE e IHQ) colaboraram entre si. Assim, estes resultados evidenciam a provável transmissão do PCV-2 pelo sêmen para a leitegada e também o potencial infeccioso do vírus entre os suínos

No description available.

<i>Actinobacillus pleuropneumoniae</i> is the etiological agent of contagious swine pleuropneumonia, an economically important disease of the swine industry worldwide. Improved control of this disease requires enhanced understanding of the factors contributing to pathogenesis. The objectives of this study were to investigate the immune response and virulence properties of the 110-kilodalton (110-KDa) hemolysins [hemolysin I (HlyI) and hemolysin II (HlyII)] of <i>A. pleuropneumoniae</i>. Several monoclonal antibodies (MAb) to the hemolysins were developed. An IgGl. MAb (8C2) specific for HlyII, as determined by immunoblotting, was cross-linked to Protein A-Sepharose, and HlyII was purified from serotypes 1 and 5 by immunoaffinity chromatography. An indirect enzyme-linked immunosorbent assay (ELISA) using MAb 8C2, or affinitypurified rabbit IgG to both hemolysins, was developed for detection of swine antibody to one or both hemolysins, respectively. In comparison with the complement fixation test, the ELISA was highly sensitive and specific, and was able to identify animals infected with or exposed to most, if not all, serotypes of <i>A. pleuropneumoniae</i>. Several nonhemolytic mutants of <i>A. pleuropneumoniae</i> serotype 5 were isolated following electroporation of the parent with an hemolysin gene whose open-reading-frame was disrupted with a kanamycin resistance gene. One mutant was characterized for phenotypic and pathogenic properties. Biochemical profiles, growth rate, capsule content, and lipopolysaccharide and whole cell protein electrophoretic profiles of the parent and one of the mutants were similar. The nonhemolytic mutant lacked both HlyI and HlyII proteins in culture supernatant and in whole cell lysates as determined by immunoblot analysis; extracellular and intracellular hemolytic and cytotoxic activity was also absent. The mutant was avirulent in mice and pigs at doses greater than 10 times the lethal dose of the parent. Unlike the parent, the nonhemolytic mutant failed to confer protection against lethal challenge in mice following immunization. Thus, one or both hemolysins are essential for virulence and immunoprotection in <i>A. pleuropneumoniae</i> serotype 5. / Ph. D.

The effect of exposure to creep feed at 10 d of age vs no exposure to creep feed or sow's feed on the ability of pigs weaned at 21 d of age to respond to an oral challenge of E. coll or to absorb ovalbumin or xylose was investigated. Eighty pigs (45 exposed, 35 control) were orally challenged 24 h after weaning with 3x1011 organisms of E. coli (0157 H88AC:H43); control pigs tended (P<.10) to scour more than the exposed pigs (46% vs 27%). Ovalbumin absorption was similar for both exposed and control pigs (P>.10), but absorption for both treatments increased (P<.001) from d 1 to d 4 and decreased to d 13 (P<.001). Xylose absorption was less (P<.02) at d 1 for exposed pigs compared with control pigs (0.781 vs .825 mmol) with no differences (P>.20) occurring thereafter. Lowest xylose absorption for both treatments occurred on d 7. Creep feeding conferred some protection to the E. coll challenge, but had little effect on intestinal absorption of ovalbumin and xylose. / Master of Science

Mucin was isolated for incorporation in bacteriological media by reduction and proteolysis of mucous gel from porcine small intestine. Mucin prepared in this study contained (by weight) 37.2% protein, 58.7% carbohydrate (4.6% fucose, 9.4% mannose, 10.7% sialic acid, 13.5% galactose, and 20.5% hexosamine), and 3.7% ester sulfate. Fractionation of mucin on Sepharose CL-4B yielded one peak which eluted at the void volume. However, sodium dodecyl sulfate gel electrophoretic patterns contained 9 polypeptide bands of which 6 stained with periodic acid—Schiff reagent. Proline, serine, and threonine residues accounted for 26% (by weight) of the total protein in the preparation. Half-cysteine residues made up another 1%. Intrinsic viscosity of mucin prepared by reduction and proteolysis was 135 ml/g. Mucin was incorporated into a minimal bacteriological medium as the sole-source of carbon and nitrogen. Enterotoxigenic and non-enterotoxigenic Escherichia coli grew equally well in mucin medium at levels comparable to growth in 3 mM glucose medium. Growth did not appear to be limited by availability of metabolizable substrates. Spent mucin medium supported growth in comparable numbers. E. coli P-155 produced heat-stable and heat-labile enterotoxins during growth in both mucin medium and fresh mucosal scrapings medium. E. coli utilized total hexose and protein in mucin medium at comparable levels (6 to 10%). Increases in reducing end groups (0.28 μ moles/ml) and free amino sugar end groups (0.04 μmoles/ml) during growth were detected. E. coli used approximately 15% of the total carbohydrate in mucin medium including 36% of the galactose, 15% of the fucose, and 27% of the mannose. Utilization of mucin by QL ggli produced minor changes in gel filtration patterns on Sepharose CL-4B. Twelve strains of E. coli were examined for glycosidase activity during growth on mucin. All twelve produced a cell-bound and an extracellular α-fucosidase although the majority of activity was cell-bound. Although α-fucosidase was a constitutive enzyme of E. coli P-155, maximum activity was observed during exponential growth in mucin medium. Eleven strains produced cell-bound α-galactosidase. No extracellular activity of this enzyme was detected. Maximum levels of induced α-galactosidase activity were obtained in late exponential to early stationary growth of E. coli. E. coli ATCC 23723, a mutant of E. coli K12 lacking the galactoside permease gene, did not produce α-galactosidase activity during growth on mucin. No α-mannosidase activity was detected using nitrophenylmannoside as substrate. Porcine small intestinal mucin was a positive chemoattractant for E. coli in capillary assays. Optimal chemotactic response by E. coli P-155 in capillary experiments was obtained at a mucin concentration of 1 mg dry wt/ml at a pH of 7.0. Spent mucin was still a positive chemoattractant for E. coli P-155 and 123 despite losing 15% of the total mucin carbohydrate. / Ph. D.

No description available.