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

La propagation de bactéries à Gram négatif multirésistantes aux antibiotiques représente un problème de santé publique majeur urgent à résoudre car le risque d’un retour à l’ère pré-antibiotique est réel. Parmi les modes de résistance existant, la production de métallo-B-lactamases (MBLs) responsables de l’inactivation des B-lactamines, la famille d’antibiotiques la plus utilisée, représente un challenge thérapeutique.Les travaux décrits dans ce manuscrit concernent la synthèse, la caractérisation et l’évaluation biologique de composés construits autour d’un cœur 2,4-dihydro-3H-1,2,4-triazole-3-thione substitués en deux positions. En se basant sur des études de criblage in silico et des études cristallographiques ayant permis d’identifier ce noyau comme un bon candidat dans le développement d’inhibiteurs de MBLs, la synthèse de différentes séries d’analogues a été entreprise afin d’identifier de nouveaux inhibiteurs pouvant potentiellement atteindre les tests cliniques.Dans un premier temps, une série de composés 4-amino-1,2,4-triazole-3-thione substitués en position 5 a été préparée en suivant des voies de synthèse classiques. Différentes séries ont ensuite été développées en introduisant une diversité structurale et fonctionnelle en position 4. Ces composés ont ensuite été testés sur des enzymes représentatives des 3 sous-classes de MBLs et les plus intéressants ont été évalués sur bactéries résistantes recombinantes.Afin de réaliser une évaluation rapide des produits synthétisés au sein du laboratoire, une méthode de criblage à moyen débit en plaque 96 puits sur cinq MBLs représentatives a été mise au point et validée grâce à l’appui de nos collaborateurs spécialistes des MBLs. / The spread of multiresistant Gram negative bacteria is a growing threat to public health and the risk of return to the pre-antibiotic era is real. Among existing resistance modes, the production of metallo-B-lactamases (MBLs) responsible of the inactivation of B-lactams, the most used family of antibiotics, represents a therapeutical challenge.This manuscript describes the synthesis, characterization and biological evaluation of compounds built on a 2,4-dihydro-3H-1,2,4-triazole-3-thione scaffold substituted on two positions. Based on previous in silico screening and crystallographic studies, which identified this structure as a good candidate for MBLs inhibition, several series have been developed to found new inhibitors that could potentially be amenable to clinical development.First, 1,2,4-triazole-3-thione compounds substituted at position 5 have been prepared following classical pathways. Then, several series have been developed where the structural and functional diversity was introduced at position 4. Compounds have been tested on representative MBLs of the three sub-classes and the most interesting ones on recombinant resistant bacteria.To perform a rapid screening of compounds in the laboratory, a method of medium throughput screening inhibition tests on five MBLs performed in 96-wells plate has also been developed and validated during this study with the help of our collaborators specialists of MBLs