Mannheimia haemolytica (M. haemolytica)-induced bovine respiratory disease causes millions of dollars in economic losses to Canadian cattle industry. Contemporary management strategies built around the use of antimicrobials are proving to be increasingly unavailing and lead to drug residues in meat which may contribute to the development of multi drug resistant bacteria. Many M. haemolytica vaccines are effective in stimulating antibody responses but studies of vaccina-tion in young calves and the cattle exposed to M. haemolytica (high-risk cattle) have shown poor vaccine efficacy. Antimicrobial peptides (AMPs) may help in the management of respiratory disease caused by M. haemolytica while minimizing the risk of drug residues in animal-derived food products. AMPs are positively charged molecules that can kill bacteria primarily through the electrostatic interactions with the anionic bacterial lipid bilayer. Since the primary target of AMPs is the bac-terial surface charge, which is evolutionarily conserved, the development of resistance towards AMPs seems less likely. These peptides hold potential to replace or reduce the use of antibiotics. Human β-Defensin 3 (HBD3) and Microcin J25 (MccJ25) are cationic peptides that have shown good activity against many Gram-negative bacteria. Five peptides, namely native HBD3, three synthetic HBD3 analogues (28 amino acid, 20AA, and 10AA), and MccJ25 were selected for microbicidal activity against M. haemolytica. Three C-terminal analogues of HBD3 with all cysteines replaced with valines were manually synthesized using solid phase peptide synthesis (SPPS). In all the three analogue, replacement of cysteine with valine rendered them linear and increased their antibacterial activity. Minimum Bactericidal concentration (MBC) assays were performed with the final inoculum size of 1-5x105 cells/ml, with the exception of the 10AA analogue which was incubated with 104 cells/ml final inoculum size. The antimicrobial assay showed that M. haemolytica was intermediately sensitive to HBD3, 28AA and 20AA analogue with an MBC of 50 µg/ml. MccJ25 had limited effect with an MBC greater than 100 µg/ml. The MBC value of 6.3 µg/ml achieved with the 10AA analogue is likely a result of lower final inoculum size. AMPs have several immunomodulatory functions, and these peptides can act as chemoattractant, induce cytokine release that in turn leads to chemotaxis of monocytes and neutrophils. Since neutrophils play an important role in the pathogenesis of BRD, the chemotactic effect of HBD3, 20AA and 28AA peptides on bovine neutrophils was studied using Boyden chamber. Peripheral blood neutrophils isolated from normal healthy cattle showed chemotaxis towards HBD3 and 20AA peptides (P<0.05) but not towards 28AA analogue. Co-incubation of neutrophils with any of the peptides did not affect their chemotaxis towards N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP). Based on these data, it can be concluded that HBD3 and its analogues showed antimicrobial ef-fects against M. haemolytica but MccJ25 had limited microbicidal activity against M. haemolytica. While HBD3 and 20AA analogue were chemotactic for bovine peripheral blood neutrophils, none of the peptides inhibited fMLP-induced migration of neutrophils. These peptides hold potential for further in vivo testing to develop them for use to manage M. haemolytica-induced respiratory disease in cattle.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / In this study, the Eucalyptus staigeriana essential oil (ESO) was nanoencapsulated and determined the bactericidal effect of its active principle against two strains of pathogenic mircrorganisms, as a preliminary study for use in food preservation. The process occurred by forming a nanoemulsion and spray-drying, using the cashew gum (CG) as encapsulating material. The nanoparticles were characterized by analysis of particle size distribution, zeta potential, absorption spectroscopy in the infrared Fourier transform spectroscopy (FTIR), thermal analysis (TGA/DSC), in vitro release kinetics, gas chromatography coupled to mass spectrometry (GC-MS) and stability of the encapsulated. Was also determined the Minimum Bactericidal Concentration (MBC) of nanoparticles, essential oil, and cashew gum to evaluate its antimicrobial activity against Listeria monocytogenes ATCC 19115 (Gram-positive) and Salmonella Enteritidis IAL 1132 (Gram-negative). The nanoparticles had size ranging from 27.70  3.42 nm to 432.67  41.47 nm in accordance with the formulation, and negatively charged surface. The presence of ESO in the nanoparticles is observed through changes in peak resolutions of the spectra obtained by FT-IR. Thermal analysis showed the main events of mass loss of the samples associated with the degradation of CG. The content of ESO nanoencapsulated varied between 4.76% and 7.12%. The increase in the proportion of CG favored the rapid release of oil in water due to the increased hydrophilic character, and enhance the ability of the nanoparticles to retain the ESO in the polymeric shell during the 365 days. The results for MBC indicated a bactericidal action of the nanoencapsulated oil, and pure oil more efficient in Gram-positive. However, the nanoparticles showed better results against Gram-negative bacteria, due to a possible synergistic effect between the CG and ESO. / Neste trabalho, o Ãleo essencial de Eucalyptus staigeriana (OES) foi nanoencapsulado e determinado o efeito bactericida de seu princÃpio ativo contra duas cepas de mircrorganismos patogÃnicos, como um estudo preliminar para utilizaÃÃo na conservaÃÃo de alimentos. O processo ocorreu atravÃs da formaÃÃo de uma nanoemulsÃo e secagem em spray-drying utilizando a goma de cajueiro (GC) como material encapsulante. As nanopartÃculas foram caracterizadas atravÃs das anÃlises de tamanho e distribuiÃÃo de partÃcula, potencial zeta, espectroscopia de absorÃÃo na regiÃo do infravermelho com transformada de Fourier (FTIR), anÃlise tÃrmica (TGA/DSC), cinÃtica de liberaÃÃo in vitro, cromatografia gasosa acoplada à espectrometria de massa (CG-EM) e estabilidade do encapsulado. Foi tambÃm determinada a ConcentraÃÃo Bactericida MÃnima (CBM) das nanopartÃculas, do Ãleo essencial e da goma de cajueiro para avaliar sua aÃÃo antimicrobiana contra Listeria monocytogenes ATCC 19115 (Gram-positiva) e Salmonella Enteritidis IAL 1132 (Gram-negativa). As nanopartÃculas apresentaram tamanho que variaram de 27,70  3,42 nm a 432,67  41,47 nm, de acordo com a formulaÃÃo, e a superfÃcie carregada negativamente. A presenÃa do OES nas nanopartÃculas à observada atravÃs de modificaÃÃes nas resoluÃÃes de pico dos espectros obtidos por FTIR. A anÃlise tÃrmica evidenciou os principais eventos de perda de massa das amostras associados à degradaÃÃo de GC. O teor de OES nanoencapsulado variou entre 4,76 % e 7,12 %. O aumento na proporÃÃo de GC favoreceu a uma rÃpida liberaÃÃo do Ãleo em Ãgua devido ao aumento do carÃter hidrofÃlico, alÃm de aumentar a capacidade das nanopartÃculas em reter o OES no invÃlucro polimÃrico no decorrer dos 365 dias. Os resultados para CBM indicaram uma aÃÃo bactericida do Ãleo nanoencapsulado e do Ãleo puro mais eficiente na bactÃria Gram-positiva. No entanto, as nanopartÃculas mostraram um resultado melhor contra a bactÃria Gram-negativa, devido a um possÃvel efeito sinÃrgico entre a GC e o OES.

Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2018-08-24T13:49:29Z No. of bitstreams: 2 Adrieli_Toledo2018.pdf: 1064570 bytes, checksum: b4b7ab870d6f9388d0d57ae7ea9c766d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-08-24T13:49:29Z (GMT). No. of bitstreams: 2 Adrieli_Toledo2018.pdf: 1064570 bytes, checksum: b4b7ab870d6f9388d0d57ae7ea9c766d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Scientific researches with Brazilian native species have aroused a growing interest in the search for active compounds with biological potential. The fruit species Eugenia involucrata DC. (Myrtaceae), known as “cerejeira-do-mato”, is popularly used in the form of tea with antidiarrheal and digestive action. In the literature, although researches with the fruit because to its commercial value, studies with the leaves of the species are scarce, being few data related to the biological activities of this plant. Therefore, the objective of this work was to identify the chemical components of the essential oil by gas chromatography coupled to mass spectrometry (GC-MS) and to perform the phytochemical exploration of the plant extracts through colorimetric visualization and / or precipitate formation. In addition, the antimicrobial activity by the broth microdilution technique and the antioxidant activity by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method were evaluated. In the analysis of the essential oil by GC-MS 28 compounds were identified, all sesquiterpenes, corresponding to 89.41% of the essential oil. The antimicrobial activity of the oil was observed for all Gram-positive bacteria tested and for yeast C. albicans. The essential oil presented a reduction capacity of DPPH up to 66.81%, evidencing its antioxidant potential. The phytochemical prospection of the extracts detected the presence of saponins, steroids, flavonoids and tannins. The antimicrobial and antioxidant activities were observed in all extracts tested. The extracts that presented the best results were: methanolic with antimicrobial activity between 3.12 and 25 mg.mL-1 and antioxidant percentage of 95.85% in the concentration of 1.0 mg.mL-1; and the ethanolic with antimicrobial activity between 3.12 and 50 mg.mL-1 and antioxidant activity of 92.84% in the concentration of 1.0 mg.mL-1. It is suggested that the biological activities found for the essential oil are related to its major compounds: elixene (26.53%), β-caryophyllene (13.16%), α-copaene (8.41%) and germacrene D (7.17%). Regarding the extracts, due to the proven presence of flavonoids and tannins, it is suggested that these phenolic compounds are related to the activities found. / As pesquisas científicas com espécies nativas brasileiras têm despertado um crescente interesse na busca por compostos ativos com potencial biológico. A espécie frutífera Eugenia involucrata DC. (Myrtaceae), conhecida por cerejeira-do-mato, é popularmente usada na forma de chá com ação antidiarreica e digestiva. Na literatura, apesar de pesquisas com o fruto devido ao seu valor comercial, estudos com as folhas da espécie são escassos, sendo encontrados poucos dados relacionados as atividades biológicas dessa planta. Diante disso, este trabalho objetivou identificar os componentes químicos do óleo essencial por cromatografia gasosa acoplada à espectrometria de massas (CG-EM) e realizar a prospecção fitoquímica dos extratos vegetais por meio da visualização colorimétrica e/ou na formação de precipitado. Além disso, foi avaliada a atividade antimicrobiana pela técnica de microdiluição em caldo e a atividade antioxidante pelo método do 2,2-difenil-1-picril-hidrazila (DPPH). Na análise do óleo essencial por CG-EM identificou-se 28 compostos, todos sesquiterpenos, correspondendo a 89,41% do óleo essencial. A atividade antimicrobiana do óleo foi observada para todas as bactérias Gram-positivas testadas e para a levedura C. albicans. O óleo essencial apresentou capacidade redutora de radicais DPPH de até 66,81%, evidenciando seu potencial antioxidante. A prospecção fitoquímica dos extratos detectou a presença de saponinas, esteroides, flavonoides e taninos. As atividades antimicrobiana e antioxidante foram observadas em todos os extratos testados. Os extratos que apresentaram os melhores resultados foram: metanólico com atividade antimicrobiana entre 3,12 e 25 mg.mL-1 e percentual antioxidante de 95,85% na concentração de 1,0 mg.mL-1; e o etanólico com atividade antimicrobiana entre 3,12 e 50 mg.mL-1 e atividade antioxidante de 92,84% na concentração de 1,0 mg.mL-1. Sugere-se que as atividades biológicas encontradas para o óleo essencial estejam relacionadas aos seus compostos majoritários: elixeno (26,53%), β-cariofileno (13,16%), α-copaeno (8,41%) e germacreno D (7,17%). Referente aos extratos, devido a comprovada presença de flavonoides e taninos, sugere-se que estes compostos fenólicos estejam relacionados as atividades encontradas.

No description available.

No description available.

HERCULANO. Emanuele Duarte. Óleo essencial de Eucalyptus staigeriana nanoencapsulado para utilização como conservante em alimentos. 2014. 86 f. : Dissertação (mestrado) - Universidade Federal do Ceará, centro de Ciências Agrárias, Programa de Pós-Graduação em Tecnologia de Alimentos, Fortaleza-CE, 2014 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-02T15:23:10Z No. of bitstreams: 1 2014_dis_edherculano.pdf: 2524611 bytes, checksum: a2bde63e81c86e10551edb1c7e551872 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-02T15:24:28Z (GMT) No. of bitstreams: 1 2014_dis_edherculano.pdf: 2524611 bytes, checksum: a2bde63e81c86e10551edb1c7e551872 (MD5) / Made available in DSpace on 2016-06-02T15:24:28Z (GMT). No. of bitstreams: 1 2014_dis_edherculano.pdf: 2524611 bytes, checksum: a2bde63e81c86e10551edb1c7e551872 (MD5) Previous issue date: 2014 / In this study, the Eucalyptus staigeriana essential oil (ESO) was nanoencapsulated and determined the bactericidal effect of its active principle against two strains of pathogenic mircrorganisms, as a preliminary study for use in food preservation. The process occurred by forming a nanoemulsion and spray-drying, using the cashew gum (CG) as encapsulating material. The nanoparticles were characterized by analysis of particle size distribution, zeta potential, absorption spectroscopy in the infrared Fourier transform spectroscopy (FTIR), thermal analysis (TGA/DSC), in vitro release kinetics, gas chromatography coupled to mass spectrometry (GC-MS) and stability of the encapsulated. Was also determined the Minimum Bactericidal Concentration (MBC) of nanoparticles, essential oil, and cashew gum to evaluate its antimicrobial activity against Listeria monocytogenes ATCC 19115 (Gram-positive) and Salmonella Enteritidis IAL 1132 (Gram-negative). The nanoparticles had size ranging from 27.70 ± 3.42 nm to 432.67 ± 41.47 nm in accordance with the formulation, and negatively charged surface. The presence of ESO in the nanoparticles is observed through changes in peak resolutions of the spectra obtained by FT-IR. Thermal analysis showed the main events of mass loss of the samples associated with the degradation of CG. The content of ESO nanoencapsulated varied between 4.76% and 7.12%. The increase in the proportion of CG favored the rapid release of oil in water due to the increased hydrophilic character, and enhance the ability of the nanoparticles to retain the ESO in the polymeric shell during the 365 days. The results for MBC indicated a bactericidal action of the nanoencapsulated oil, and pure oil more efficient in Gram-positive. However, the nanoparticles showed better results against Gram-negative bacteria, due to a possible synergistic effect between the CG and ESO. / Neste trabalho, o óleo essencial de Eucalyptus staigeriana (OES) foi nanoencapsulado e determinado o efeito bactericida de seu princípio ativo contra duas cepas de mircrorganismos patogênicos, como um estudo preliminar para utilização na conservação de alimentos. O processo ocorreu através da formação de uma nanoemulsão e secagem em spray-drying utilizando a goma de cajueiro (GC) como material encapsulante. As nanopartículas foram caracterizadas através das análises de tamanho e distribuição de partícula, potencial zeta, espectroscopia de absorção na região do infravermelho com transformada de Fourier (FTIR), análise térmica (TGA/DSC), cinética de liberação in vitro, cromatografia gasosa acoplada à espectrometria de massa (CG-EM) e estabilidade do encapsulado. Foi também determinada a Concentração Bactericida Mínima (CBM) das nanopartículas, do óleo essencial e da goma de cajueiro para avaliar sua ação antimicrobiana contra Listeria monocytogenes ATCC 19115 (Gram-positiva) e Salmonella Enteritidis IAL 1132 (Gram-negativa). As nanopartículas apresentaram tamanho que variaram de 27,70 ± 3,42 nm a 432,67 ± 41,47 nm, de acordo com a formulação, e a superfície carregada negativamente. A presença do OES nas nanopartículas é observada através de modificações nas resoluções de pico dos espectros obtidos por FTIR. A análise térmica evidenciou os principais eventos de perda de massa das amostras associados à degradação de GC. O teor de OES nanoencapsulado variou entre 4,76 % e 7,12 %. O aumento na proporção de GC favoreceu a uma rápida liberação do óleo em água devido ao aumento do caráter hidrofílico, além de aumentar a capacidade das nanopartículas em reter o OES no invólucro polimérico no decorrer dos 365 dias. Os resultados para CBM indicaram uma ação bactericida do óleo nanoencapsulado e do óleo puro mais eficiente na bactéria Gram-positiva. No entanto, as nanopartículas mostraram um resultado melhor contra a bactéria Gram-negativa, devido a um possível efeito sinérgico entre a GC e o OES.