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Atividade antimicrobiana do tianfenicol sobre bactérias patogênicas de peixes / Antibacterial activity of thiamphenicol against fish pathogenic bacteriaAssane, Inácio Mateus 28 February 2018 (has links)
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Previous issue date: 2018-02-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Os surtos de bacterioses na piscicultura são imprevisíveis, por essa razão é necessário dispor de opções terapêuticas eficazes para reduzir a morbidade e mortalidade. Para que a terapia seja eficaz, a escolha do antimicrobiano deve se basear nas informações farmacocinéticas do fármaco no hospedeiro, nas condições de produção e na sensibilidade do patógeno. No Brasil, atualmente só dois antimicrobianos são legalizados para uso na aquicultura, a oxitetraciclina (OTC) e o florfenicol (FFC), os quais muitas vezes são ineficazes. Destes, somente o FFC é autorizado para tratar bacterioses em tilápia-do-Nilo, a espécie mais produzida no país. Este cenário nos levou a investigar a atividade antimicrobiana do tianfenicol (TAF) contra as principais bactérias patogênicas de peixes cultivados no Brasil. Foi determinada a concentração inibitória mínima (CIM) e a concentração bactericida mínima (CBM) do TAF para 49 cepas isoladas de surtos de bacteriose ocorridos no período 2011 a 2017 em três estados. Adicionalmente, avaliou-se a atividade antimicrobiana do TAF (G1: 10 mg/kg), do FFC (G2: 10 mg/kg) e da combinação do TAF com o FFC (G3: TAF+FFC: 5 + 2,5 mg/kg e G4: 2,5 + 1,25 mg/kg) no tratamento de aeromonose em tilápia-do-Nilo experimentalmente infectadas com Aeromonas hydrophila. Como resultado do estudo in vitro, mais da metade das cepas testadas foram sensíveis ao TAF, sendo que os gêneros Aeromonas, Lactococcus e Vibrio foram os mais sensíveis. No estudo in vivo, o TAF foi eficaz no tratamento da aeromonose em tilápia-do-Nilo, tanto isolado como combinado. Os grupos G1, G2, G3, G4 e o controle apresentaram uma taxa de sobrevivência de 88,33 ± 11,55%; 70 ± 10%; 73,33 ± 11,55%; 85,93 ± 5,13% e 3,33 ± 5,77%, respectivamente, sendo todos diferentes do controle (p < 0,001). Os resultados do estudo sugerem que o TAF pode ser uma boa opção de tratamento de aeromonose, lactococose e vibriose em peixes. Além disso, a combinação do TAF com o FFC apresentou um efeito sinérgico, mostrando que é possível reduzir a quantidade de antimicrobiano e obter o mesmo efeito terapêutico. / Outbreaks of bacterial diseases in fish farm are unpredictable; therefore, it is necessary to have effective therapeutic options to reduce the morbidity and mortality. For effective therapy, the anticipated pharmacokinetics and antibacterial activity of the antimicrobial in the target fish species under the given conditions must be considered before decide which antimicrobial to use. In Brazil, only two antimicrobials are approved for use in aquaculture, oxytetracycline (OTC) and florfenicol (FFC), which are often innefective. Moreover, only FFC is approved for use to treat bacterial diseases in Nile tilapia, the main specie in Brazil. This scenario led us to investigate the antibacterial activity o thiamphenicol (TAP) against the main bacteria infecting fishes in Brazil. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of TAP were determined for 49 strains isolated from diseases outbreaks registered during 2011 – 2017 in three States. Additionally the antibacterial activity of TAP (10 mg kg-1), FFC (10 mg kg-1) and TAF combined with FFC (G3: TAF+FFC: 5 + 2.5 mg kg-1 e G4: 2.5 + 1.25 mg kg-1) against Aeromonas hydrophila in Nile tilapia aeromoniosi models were evaluated. More than half of the tested strains were in vitro sensitive to TAP, being TAP highly potent against Aeromonas, Lactococcus, and Vibrio. The in vivo therapy with TAP alone and combined with FFC was effective to treat aeromoniosis in Nile tilapia. Groups G1, G2, G3, G4 and control had survival rate of 88.33 ± 11.55%; 70 ± 10%; 73.33 ± 11.55%; 85.93 ± 5.13% e 3.33 ± 5.77%, respectively, all being different from the control (p < 0,001). These findings suggest the potential of TAP as a treatment option for aeromoniosis, lactococcosis and vibriosis. The combination of TAF and FFC has a synergy effect, showing that it is possible to reduce the amount of antimicrobial while maintaining the therapeutic effectiveness. / 190049/2015-4
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Biocatalytic processin obtaining products with high added value: chemoenzymatic synthesis of α-amino acids, derivates thiamphenicol and (S)-dapoxetina / Processos biocatalÃticos na obtenÃÃo de produtos com alto valor agregado: sÃnteses quimioenzimÃticas de α- aminoÃcidos, derivados do tianfenicol e (S)-dapoxetina.Marcos Reinaldo da Silva 28 February 2014 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / The present work is divided into three chapters, in which we report the use of lipases to obtain precursors of α-amino acid, derivatives thiamphenicol and chemoenzymatic synthesis of (S)-dapoxetine. The first chapter refers to the use of the lipase from Rhyzomucor miehei, which by means of kinetic resolution of N-acetyl-α-amino esters was possible to obtain derivatives with high values of enantiomeric excesses. The second section aims at obtaining derivatives of thiamphenicol applying the lipase from Candida rugosa for the reaction of hydrolysis of the diacetate thiamphenicol, and Candida antarctica lipase B by acylation process. Finally, the third section reports the chemoenzymatic synthesis of (S)-dapoxetine in the enantiopure form by kinetic resolution process via transesterification reactions of 3-chloro-1-phenylpropan-1-ol, using lipase from Candida rugosa. / O presente trabalho encontra-se dividido em trÃs capÃtulos, na qual relatamos a utilizaÃÃo de lipases para obtenÃÃo de precursores de α-aminoÃcidos, derivados de tianfenicol e a sÃntese quimioenzimÃtica da (S)-dapoxetina. O primeiro capÃtulo refere-se à utilizaÃÃo da lipase a partir de Rhyzomucor miehei, que por meio de uma resoluÃÃo cinÃtica de N-acetil-α-aminoÃsteres foi possÃvel obter derivados com elevados valores de excessos enantiomÃricos. O segundo capÃtulo visa a obtenÃÃo de derivados do tianfenicol aplicando a lipase a partir da Candida rugosa para a reaÃÃo de hidrÃlise do diacetato de tianfenicol, e a lipase B obtida a partir de Candida antarctica por processo de acilaÃÃo. Por fim, o terceiro capÃtulo relata a sÃntese quimioenzimÃtica da (S)-dapoxetina de forma enantiopura por processo de resoluÃÃo cinÃtica via reaÃÃes de transesterificaÃÃo do 3-cloro-1-fenilpropan-1-ol, usando a lipase obtida a partir da Candida rugosa.
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Études biopharmaceutiques et formulation de chloramphénicol et de thiamphénicol pour le traitement ciblé des infections pulmonaires par voie inhalée / Biopharmaceutical studies and formulation of chloramphenicol and thiamphenicol for the treatment of pulmonary infections by inhalation routeNurbaeti, Siti Nani 13 December 2017 (has links)
L'émergence rapide de bactéries résistantes et l’absence de nouveaux traitements efficaces ont conduit à réutiliser d’anciens antibiotiques. Le chloramphenicol (CHL) et le thiamphenicol (THA) ont ainsi été proposés pour traiter les infections respiratoires multirésistantes. Leur administration directe dans les poumons sous forme d’aérosols thérapeutiques devrait augmenter leur efficacité et minimiser l’exposition systémique responsable d’effets secondaires, en particulier lors de traitements prolongés. Ce travail de thèse a eu pour objectifs de réaliser des étudies biopharmaceutiques et de développer des formulations d’aérosols pour la voie pulmonaire. La perméabilité membranaire du CHL et du THA a été évaluée sur le modèle d’épithélium bronchique Calu-3 et leur pharmacocinétique a été réalisée chez le rat après administrations intratrachéale et intraveineuse. La perméabilité membranaire in vitro du CHL s’est révélée élevée, et intermédiaire pour le THA. Les deux antibiotiques sont substrats de transporteurs membranaires d’efflux. Les études pharmacocinétiques, cohérents avec les études in vitro, ont montré un impact nul de la voie d’administration dans cas du CHL et modéré dans le cas du THA. Par conséquent, pour prolonger l’exposition pulmonaire à ces antibiotiques, des formulations à libération prolongées basées sur des nanoparticules ont été incluses dans des poudres sèches de microsphères pour inhalation. Ces poudres se caractérisent par une teneur optimale, des propriétés aérodynamiques satisfaisantes et un profil de libération prolongée, et sont donc prometteuses pour l’administration pulmonaire de CHL ou de THA sous la forme d’aérosols. / The rapid emergence of resistant bacteria and the lack of new efficient treatments lead to re-use old forgotten, but still effective, antimicrobials. In particular, chloramphenicol (CHL) and thiamphenicol (THA) have been proposed to treat multidrug-resistant pulmonary bacterial infections. Their direct administration into the lungs as therapeutic aerosols should increase their efficiency and minimize whole body exposure responsible for adverse effects, particularly in the case of prolonged treatments. The purpose of these PhD. works was to perform biopharmaceutical studies and to develop an effective aerosol formulation for lung delivery. The membrane permeability of CHL and THA was evaluated in vitro in the Calu-3 bronchial epithelial cell model and pharmacokinetic (PK) studies were carried out in rats after intratracheal and intravenous administration. In vitro membrane permeability of CHL was high, but intermediate for THA. Both compounds were shown to be substrates of membrane efflux transporters. In agreement with these findings, the PK studies showed that the administration route had no impact in the case of CHL and a moderate one in the case of THA. Therefore, in order to prolong lung exposure to CHL and THA, nanoparticle-based formulations with sustained release properties were formulated using the palmitate ester prodrugs of CHL and THA. To ease administration, nanoparticles were included in microsphere-based dry powder for inhalation. These powders showed an optimal content, satisfactory aerodynamic properties and sustained drug release, which make them promising formulations for lung delivery of CHL and THA as aerosols.
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