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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Efeito da incorporação de agentes antimicrobianos sobre propriedades físicas de materiais resilientes temporários para base de prótese / Effect of the incorporation of antimicrobial agents on the physical properties of temporary resilient materials for denture base relining

Lima, Jozely Francisca Mello 31 October 2013 (has links)
O objetivo do presente estudo foi avaliar o efeito da adição de mínimas concentrações inibitórias (MCIs) de agentes antimicrobianos para biofilme de Candida albicans na sorção de água e solubilidade de materiais resilientes temporários (Softone e Trusoft) para reembasamento de próteses removíveis. Os grupos de estudo (n=10) foram formados por corpos de prova circulares (50 mm x 0,5 mm) dos materiais sem (controle) ou com a incorporação das MCIs de três fármacos utilizados para tratamento de estomatite protética: nistatina (Ni)-0,032g/mL; diacetato de clorexidina (Cl)- 0,064g/mL; cetoconazol (Ce)- 0,128g/mL. Para determinar a sorção de água e solubilidade, as amostras foram dessecadas, imersas em água por 24 h, 7 ou 14 dias, pesadas, dessecadas e pesadas novamente. Os dados obtidos (&#x3BC;g/mm3) foram analisados por ANOVA 3 fatores e teste de Tukey (&#x3B1;=0,05). Comparado aos respectivos controles, a sorção de água dos dois materiais avaliados aumentou com a adição de nistatina e clorexidina após 24 h e 7 dias de imersão em água (P<0,0001). Após 14 dias de avaliação, exceto pela clorexidina (P<0,0001) no Softone (483,00 ± 61,00 &#x3BC;g/mm3), a sorção dos materiais não foi afetada (P>0,05) pela adição dos fármacos (Softone: Ni- 310,72 ± 55,00 &#x3BC;g/mm3; Ce- 202,13 ± 52,28 &#x3BC;g/mm3/ Trusoft: Ni- 320,26 ± 22,89 &#x3BC;g/mm3; Ce: 300,45 ± 69,49 &#x3BC;g/mm3; Cl: 331,01 ± 48,18 &#x3BC;g/mm3) em comparação aos respectivos controles (Softone: 244,00 ± 42,00 &#x3BC;g/mm3; Trusoft: 274,85 ± 83,12 &#x3BC;g/mm3). Para todos os grupos, o tempo de imersão aumentou (P<0,0001) a solubilidade do Softone (24h: 18,82 ± 9,80 &#x3BC;g/mm3; 7d: 32,16 ± 4,48 &#x3BC;g/mm3; 14d: 58,81 ± 8,79 &#x3BC;g/mm3), mas não do Trusoft (24h: 12,46 ± 4,51 &#x3BC;g/mm3; 7d: 14,34 ± 5,20 &#x3BC;g/mm3; 14d: 15,48 ± 5,68 &#x3BC;g/mm3) (P>0,05). Em relação aos controles e para todos os períodos, a solubilidade dos dois materiais foi alterada com clorexidina e cetoconazol (P<0,0001), mas não sofreu influência da nistatina (P>0,05). Foi possível concluir após 14 dias de imersão em água, a adição das MCIs de nistatina e cetoconazol nos dois materiais resilientes e de clorexidina no Trusoft não interferiu com a sorção de água. A solubilidade dos dois materiais temporários testados não foi alterada pela nistatina em até 14 dias de avaliação. / The objective of the present study was to evaluate the addition of minimum inhibitory concentrations (MICs) of antimicrobial agents for C. albicans biofilm on the water sorption and solubility of temporary resilient materials (Softone e Trusoft) for denture base relining. Test groups (n=10) were formed by disc specimens (50 mm x 0.5 mm) of the materials without (control) or with incorporation of the MICs of three drugs for denture stomatitis\' treatment: nystatin (Nt)- 0.032g/mL; chlorhexidine diacetate (Cl)- 0.064g/mL; ketoconazole (Kt)- 0.128g/mL. To determine the water sorption and solubility, samples were dried, immersed in water for 24 h, 7 or 14 days, weighed, dried and weighed again. Data (&#x3BC;g/mm3) were analyzed by 3-way ANOVA and Tukeys test (&#x3B1;=.05). Compared to the respective controls, the water sorption of the two materials evaluated increased with the addition of nystatin and ketoconazole after 24 h and 7 days of water immersion (P<.0001). After 14 days of evaluation, except by chlorhexidine (P<.0001) in Softone (483.00 ± 61.00 &#x3BC;g/mm3), the sorption of the materials was not affected (P>.05) by the addition of the drugs (Softone: Nt- 310.72 ± 55.00 &#x3BC;g/mm3; Kt- 202.13 ± 52.28 &#x3BC;g/mm3 / Trusoft: Nt- 320.26 ± 22.89 &#x3BC;g/mm3; Kt: 300.45 ± 69.49 &#x3BC;g/mm3; Cl: 300.45 ± 69.49 &#x3BC;g/mm3) compared to the respective controls (Softone: 244.00 ± 42.00 &#x3BC;g/mm3; Trusoft: 274.85 ± 83.12 &#x3BC;g/mm3). For all groups, the immersion time increased (P<.0001) the solubility of Softone (24h: 18.82 ± 9.80 &#x3BC;g/mm3; 7d: 32.16 ± 4.48 &#x3BC;g/mm3; 14d: 58.81 ± 8.79 &#x3BC;g/mm3), but not of Trusoft (24h: 12.46 ± 4.51 &#x3BC;g/mm3; 7d: 14.34 ± 5.20 &#x3BC;g/mm3; 14d: 15.48 ± 5.68 &#x3BC;g/mm3) (P>.05). In comparison to the controls, and for all periods the solubility of the both materials was affected with chlorhexidine and ketoconazole (P<.0001), but not was influenced by nystatin (P>.05). It can be concluded that after 14 days of water immersion the addition of MICs of nystatin and ketoconazole in the both resilient materials and chlorhexidine in the Trusoft did not affect the water sorption. The solubility of the two temporary materials tested was not altered by nystatin up to 14 days.
232

Synthetic approaches towards gold (I) and silver (I) complexes of functionalised N-heterocyclic carbene ligands

Hickey, James Laurence January 2009 (has links)
This work focuses on the design and synthesis of Au(I) and Ag(I) complexes from ligand systems that aim to combine both N-heterocyclic carbene (NHC) and phosphine ligand types. A number of synthetic approaches towards both the ligands and the prepared metal complexes have been developed, with a concerted effort on achieving the desired Au(I) or Ag(I) complexes with minimal reaction steps and synthetic style. The thesis body is divided into two main sections. The first section addresses the preparation of suitable ligand precursors of potential Au(I) and Ag(I) complexes in the form of halo- and phosphino-functionalised imidazolium salts. Several series of haloalkylimidazolium salts were prepared that encompass a range of halogens (Cl, Br, I), alkyl substituents (Me, i-Pr, t-Bu, n-Bu), differing alkyl linker length (n = 0-3), and a variety of organic spacers employed to bridge multi-imidazolium moieties. Novel bidentate and multidentate phosphinoalkylimidazolium salts were synthesised from the various haloalkylimidazolium salts, via the substitution of a halide with nucleophilic diphenylphosphide. A new approach towards rare methylene bridged phosphinomethylimidazolium salts was achieved from the reactions of halomethylimidazolium salts with diphenylphosphine. The second section investigates the preparation of Au(I) and Ag(I) complexes from the halo- and phosphino-functionalised imidazolium salts. A series of dicationic 10, 12, and 14-membered metallacyclic Ag(I) complexes were prepared from the bidentate phosphinoalkylimidazolium salts. The dinuclear Ag(I) metallacycles combine two phosphino-functionalised NHC ligands that are bridged by two coordinated Ag(I) ions in an exclusively head-to-head arrangement. A dinuclear Ag(I) metallacycle was investigated for transmetallation potential to a Au(I) complex and found to selectively transmetallate at the Ag(I) coordinated to the NHC ligands to form a bimetallic metallacycle. Unexpected phosphine oxidation of a 10-membered dinuclear Ag(I) metallacycle resulted in complex disproportionation to an isolable and rare silver(I) trimer. Metal-NHC complexes from haloalkylimidazolium salts have not been reported previously, a novel approach to the synthesis of a series of Au(I) complexes from haloalkylimidazolium salts and a respective gold source was developed and is reported herein. Different synthetic approaches towards Au(I) complexes with the phosphinoalkylimidazolium salts explored a variety of ways to generate the NHC from an imidazolium in the presence of the phosphine. A one-pot, high yielding synthesis of a dinuclear Au(I) complex from PPh3 was also devised, with controlled assembly of the complex resulting in a similar head-to-head ligand arrangement to the dinuclear Ag(I) metallacycles. As an aside, a family of mononuclear [Au(R2NHC)2]+ complexes (R = Me, i-Pr, t- Bu, n-Bu, Cy) prepared previously in our research group, was expanded because of the promising antimitochondrial activity shown by [Au(i-Pr2NHC)2]+. Two new [Au(R2NHC)2]+ complexes with simple alkyl chain functionality were prepared with fine-tuned lipophilicity in close proximity to that of [Au(i-Pr2NHC)2]+.
233

Antimicrobial contaminant removal by multi-stage drinking water filtration

Rooklidge, Stephen J. 07 May 2004 (has links)
The fate of antimicrobials entering the aquatic environment is an increasing concern for researchers and regulators, and recent research has focused on antimicrobial contamination from point sources, such as wastewater treatment facility outfalls. The terraccumulation of antimicrobials and mobility in diffuse pollution pathways should not be overlooked as a contributor to the spread of bacterial resistance and the resulting threat to human drug therapy. This review critically examines recent global trends of bacterial resistance, antimicrobial contaminant pathways from agriculture and water treatment processes, and the need to incorporate diffuse pathways into risk assessment and treatment system design. Slow sand filters are used in rural regions where source water may be subjected to antimicrobial contaminant loads from waste discharges and diffuse pollution. A simple model was derived to describe removal efficiencies of antimicrobials in slow sand filtration and calculate antimicrobial concentrations sorbed to the schmutzdecke at the end of a filtration cycle. Input parameters include water quality variables easily quantified by water system personnel and published adsorption, partitioning, and photolysis coefficients. Simulation results for three classes of antimicrobials suggested greater than 4-log removal from 1 ��g/L influent concentrations in the top 30 cm of the sand column, with schmutzdecke concentrations comparable to land-applied biosolids. Sorbed concentrations of the antimicrobial tylosin fed to a pilot filter were within one order of magnitude of the predicted concentration. To investigate the behavior of antimicrobial contaminants during multi-stage filtration, five compounds from four classes of antimicrobials were applied to a mature slow sand filter and roughing filter fed raw water from the Santiam River in Oregon during a 14-day challenge study. Antimicrobial removal efficiency of the filters was calculated from 0.2 mg/L influent concentrations using HPLC MS/MS. and sorption coefficients (K[subscript d], K[subscript oc], K[subscript om]) were calculated for schmutzdecke collected from a mature filter column. Sulfonamides had low sorption coefficients and were largely unaffected by multi-stage filtration. Lincomycin, trimethoprim, and tylosin exhibited higher sorption coefficients and limited mobility within the slow sand filter column. The lack of a significant increase in overall antimicrobial removal efficiency indicated biodegradation is less significant than sorption in multi-stage filtration. / Graduation date: 2004
234

Pharmacology and phytochemistry of South African traditional medicinal plants used as antimicrobials.

Fawole, Olaniyi Amos. January 2009 (has links)
Among all the major infectious human diseases, gastro-intestinal infections caused by microbial pathogens are a major cause of morbidity and infant death in developing countries, largely due to inadequate sewage disposal and contaminated water. Traditional health practitioners in South Africa play a crucial role in providing health care to the majority of the population. Many plants are locally used by South African traditional healers to treat microbial infections related to gastro-intestinal tracts. Ethnopharmacological and ethnobotanical studies using traditional knowledge as a selection strategy has given priority to certain plants for isolation and identification of plant novel bioactive compounds. Pharmacological and phytochemical studies of the investigated twelve medicinal plant species (from 10 families) extensively used as antimicrobials against gastro-intestinal infections was necessary to validate the use of the plants. Furthermore, to provide sufficient preliminary information for the isolation and identification of active compounds that are present in the investigated plants. Plant parts were sequentially extracted using petroleum ether (PE), dichloromethane (DCM) and 70% ethanol (EtOH). Cold water and boiled (decoction) extracts of the plant materials were prepared non- sequentially. Among the extracts, EtOH yielded the highest amount of plant substances. A total number of 85 extracts were evaluated for antibacterial activity, 80 for antifungal activity, 64 for anti-inflammatory activity, and 27 biologically active extracts were tested for genotoxicity. The microdilution method was used to determine the minimum inhibitory concentration values in the antibacterial assay against two Gram-negative bacteria (Escherichia coli ATCC 11775 and Klebsiella pneumoniae ATCC 13883) and two Gram-positive bacteria (Bacillus subtilis ATCC 6051 and Staphylococcus aureus ATCC 12600). A modified microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values in the antifungal assay against Candida albicans. Cyclooxygenase assay was used to evaluate the anti-inflammatory activity of the extracts against cyclooxygenase-1 and -2 (COX-1 and COX-2) enzymes. The plant extracts were screened first at a concentration of 250 ƒÊg/ml per test sample, and then further screened at concentrations of 125 and 62.5 ƒÊg/ml for extracts that inhibited the COX-2 enzyme. The Ames test was used to test for genotoxicity in extracts that showed interesting pharmacological activities using Salmonella typhimurium strain TA98. Among the screened extracts, 25 extracts showed good antibacterial activity with MIC values . 1.0 mg/ml. Dichloromethane extracts exhibited the greatest antibacterial activity, and Gram-positive bacteria were most susceptible. The best antibacterial activity was exhibited by Becium obovatum leaf EtOH extracts with an MIC value of 0.074 mg/ml. A broad spectrum antibacterial activity was observed by leaf extracts of Cucumis hirsutus (PE), Haworthia limifolia (PE), Protea simplex (PE and DCM) and Dissotis princeps (EtOH) against both Gram-negative and Gram-positive bacteria. No interesting antibacterial activity was exhibited by water extracts with the exception of Dissotis princeps water extract with a good antibacterial activity against Gram-positive and Gram-negative bacteria. In the antifungal assay, 6 extracts showed interesting antifungal activity. Protea simplex leaf PE extract showed the best fungicidal activity with an MFC value of 0.014 mg/ml. The best overall antifungal activity was observed in plant EtOH extracts. Some extracts from Agapanthus campanulatus (leaves and roots), Dissotis princeps (leaves), Gladiolus dalenii (corms) and Protea simplex (leaves) showed good activity against Candida albicans. Twenty one extracts inhibited the COX-1 enzyme, while fifteen extracts inhibited the COX-2 enzyme at the lowest screening concentration of 62.5 ƒÊg/ml. The highest COX-1 inhibition at a concentration of 62.5 ƒÊg/ml was exhibited by Diospyros lycioides leaf PE extract (89.1%) while Agapanthus campanulatus root DCM extract showed the highest COX-2 inhibitory activity (83.7%) at the same concentration. In the Ames test, no genotoxicity was observed in any of the extracts, however more tests need to be done to confirm these results. Thin layer chromatograms of the organic solvent plant extracts were developed. The fingerprints of the plant extracts showed colours of bands at different Rf values when viewed under UV254 and UV366 suggesting that the investigated plant species contained different compounds in the extracts. In the quest to understand the source of the plants pharmacological activities, total phenolic compounds including condensed tannins, gallotannins and flavonoids were quantitatively investigated in terms of their amounts in the aqueous methanol extracts of the plants materials using spectrophotometric methods. Alkaloids and saponins were qualitatively determined. The amounts of total phenolics were determined by the Folin Ciocalteu assay, condensed tannins were determined by the butanol-HCl assay, while rhodanine and vanillin assays were used to determine the amounts of gallotannins and flavonoids respectively. Dragendorff reagent was used to detect alkaloids in the plant extracts on thin layer chromatographic plates, while the froth test was employed to detect saponins. Secondary metabolites varied with plant parts and species with Cyperus textilis (leaf) having the highest amounts of total phenolics, condensed tannins and flavonoids. The highest amount of gallotannins was detected in Protea simplex leaf extracts. All the investigated plant materials with the exception of Haworthia limifolia leaf, Protea simplex leaf, Antidesma venosum leaf and Dissotis princeps leaf tested positively to saponins. Alkaloids were detected in Haworthia limifolia leaf (PE and EtOH), Cucumis hirsutus leaf (EtOH), Becium obovatum root (DCM), Protea simplex root and bark (EtOH), Agapanthus campanulatus root (DCM) and leaf (EtOH), Cyperus textilis root (DCM), Vernonia natalensis leaf (PE), Antidesma venosum leaf (PE), Diospyros lycioides leaf (PE) and Dissotis princeps leaf (DCM) extracts. The results obtained from the investigation of the pharmacology and phytochemistry of the plant species used to treat microbial infections related to gastro-intestinal tracts, provide sufficient preliminary information to validate the use of some of the plants in traditional medicine. The information provided might be considered sufficient for further studies aimed at isolating and identifying the active compounds in the plant species, and evaluating possible synergism amongst the isolated compounds. / Thesis (M.Sc)-University of KwaZulu-Natal, Pietermaritzburg, 2009.
235

Marine natural products as antimicrobial chemical defenses and sources of potential drugs

Lane, Amy L. 11 November 2008 (has links)
Marine organisms are widely recognized sources of an impressive array of structurally unusual compounds. Marine natural products have exhibited interesting biomedical activities, provided targets for synthetic organic chemists, and afforded opportunities for elucidation of enzymatic mechanisms involved in biosyntheses of these molecules. Secondary metabolite pathways probably evolved to mediate interactions between organisms in their natural habitats; however, the ecological functions of natural products remain poorly understood for the vast majority of cases. In the present series of investigations, I evaluate the hypothesis that macroalgal natural products play a role in defending these organisms against potentially pathogenic microbes in the marine environment. Further, I combine these ecology-driven investigations with evaluation of algal natural products as sources of novel human drugs. This combined approach resulted in discovery of 15 novel natural products from two tropical red algae, Callophycus serratus and an unidentified crustose red alga. These new molecules included seven novel carbon-carbon connectivity patterns, not previously reported in the synthetic or natural product literature, illustrating the abundance of secondary metabolite diversity among marine macroalgae. Further, many compounds exhibited both biomedical and ecological activities, suggesting the synergistic potential of combined biomedical/ecological investigations in providing drug leads as well as insights into the natural functions of secondary metabolites. Bromophycolides and callophycoic acids, natural products from C. serratus, inhibited growth of the marine fungal pathogen Lindra thalassiae. Spatially-resolved desorption ionization mass spectrometry (DESI-MS) revealed that antifungal natural products were found at specific sites on algal surfaces. The heterogeneous presentation of antimicrobial chemical defenses on host surfaces suggests the potential importance of spatial scale in understanding host-pathogen interactions, and illustrates the capacity of mass spectrometry imaging in understanding chemically-mediated biological processes. Finally, assessment of antimicrobial chemical defenses among extracts from 72 collections of tropical red algae revealed that nearly all algae were defended against at least one marine pathogen or saprophyte and further suggested the untapped potential of ecological investigations in the discovery of novel chemistry.
236

Management of reproductive tract infections among health providers and in the community in Lao People's Democratic Republic /

Sihavong, Amphoy, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.
237

Caracterização química, potencial antimicrobiano e antioxidante de polissacarídeo extraído de cará-moela (Dioscorea bulbifera) / Chemical characterization, antimicrobial and antioxidant potential of polysaccharide extracted from gizzard (Dioscorea bulbifera)

Savi, Aline 23 February 2018 (has links)
Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná / O cará-moela (Dioscorea bulbifera) é uma hortaliça não convencional que armazena substâncias de reserva em um caule aéreo modificado, e por possuir potencial nutritivo vem sendo utilizado na culinária como substituto de tubérculos tradicionais que possuem importância social e econômica como a batata inglesa e a batata doce. Há relatos na literatura que apontam para a presença de compostos de interesse biotecnológico, como saponinas, flavonoides, terpenoides, compostos fenólicos, taninos, glicosídeos, alcaloides, oxalatos, ácidos orgânicos e principalmente polissacarídeos. Para suprir as necessidades de informações sobre as propriedades dos carboidratos e suas aplicações industriais, os polissacarídeos, presentes no tubérculo do cará-moela, em estado bruto e pré-purificado, foram caracterizados quimicamente por meio de diferentes técnicas instrumentais, bem como, tiveram sua capacidade antioxidante e antimicrobiana determinada. Por meio da Ressonância Magnética Nuclear (RMN) foi possível comprovar que as amostras analisadas são formadas por macromoléculas poliméricas. Os espectros de Infravermelho com transformada de Fourier (IV-TF) apresentaram uma banda de absorção bem definida para hidroxilas (OH), característica de polissacarídeos. A utilização da Microscopia Eletrônica de Varredura (MEV) possibilitou conhecer a morfologia das amostras, as quais são compostas por películas ou "folhas". Além disso, por Difração de Raios X (DRX) foi observado que as amostras em sua maioria são compostas por material amorfo, apresentando picos de cristalinidade em aproximadamente 21,54º e 23,62º 2θ. A análise térmica detectou três regiões de perda de massa no polissacarídeo não dialisado (PND) e dialisado (PD), nas temperaturas de 100 e 150; 150 e 175; e 550 e 425 ºC, respectivamente; associadas principalmente a desidratação da amostra e à decomposição da matéria orgânica, restando uma certa quantidade de cinzas. Também foi possível determinar a matéria orgânica presente nas amostras que foi de aproximadamente 90,80 e 89,50%, na devida ordem. Interessante atividade antioxidante foi detectada por DPPH, ABTS, FRAP, remoção do radical OH, remoção do H2O2 e poder redutor, porém não apresentaram atividade antimicrobiana frente aos 20 microrganismos testados. Os resultados obtidos neste estudo permitiram caracterizar preliminarmente o polissacarídeo da D. bulbifera, dados estes não encontrados em todo o levantamento bibliográfico realizado. Além disso, tais resultados podem nortear trabalhos futuros com a aplicação deste material industrialmente, como filmes biodegradáveis, em excipientes farmacêuticos, e no encapsulamento de compostos nutracêuticos. / Dioscorea bulbifera is an unconventional vegetable that stores reserve substances in a modified aerial stem, and because it has nutritional potential, has been used in cooking as a substitute for traditional tubers that have social and economic importance such as potatoes and the sweet potato. There are reports in the literature that point to the presence of compounds of biotechnological interest, such as saponins, flavonoids, terpenoids, phenolic compounds, tannins, glycosides, alkaloids, oxalates, organic acids and mainly polysaccharides. To meet the needs of information on the properties of carbohydrates and their industrial applications, the polysaccharides, present in the raw and pre-purified carcass of the gizzard were characterized chemically by means of different instrumental techniques, as well as their antioxidant and antimicrobial capacity. By means of Nuclear Magnetic Resonance (NMR) it was possible to prove that the analyzed samples are formed by polymeric macromolecules. The Fourier Transform Infrared (IV-TF) spectra presented a well defined absorption band for hydroxyls (OH), characteristic of polysaccharides. The use of Scanning Electron Microscopy (SEM) made it possible to know the morphology of the samples, which are composed of films or "sheets". Moreover, by X-ray diffraction (XRD) it was observed that the samples are mostly composed of amorphous material, with peaks of crystallinity at approximately 21.54º and 23.62º 2θ. Thermal analysis detected three regions of mass loss in the non-dialysed polysaccharide (PND) and dialysate (PD) at temperatures of 100 and 150; 150 and 175; and 550 and 425 °C, respectively; associated mainly with sample dewatering and organic matter decomposition, leaving a certain amount of ash remaining. It was also possible to determine the organic matter present in the samples, which was approximately 90.80 and 89.50%, in due order. Interesting antioxidant activity was detected by DPPH, ABTS, FRAP, removal of the OH radical, removal of H2O2 and reducing power, but did not present antimicrobial activity against the 20 microorganisms tested. The results obtained in this study allowed preliminary characterization of the D. bulbifera polysaccharide, data not found in the entire bibliographic survey. Moreover, such results may guide future work with the application of this material industrially, as biodegradable films, in pharmaceutical excipients, and in the encapsulation of nutraceutical compounds.
238

Determination of optimal brining levels and effective chlorinated antimicrobials in three selected commercial poultry abattoirs of South Africa

Mashishi, Malesela Dennis 03 1900 (has links)
Two experiments were conducted to determine the optimal brining levels and effective chlorinated antimicrobials in three selected commercial poultry abattoirs of south Africa.The objective of the study was two fold: Firstly, the primary objective of the study was to determine the optimal inclusion level of brine for application in chicken processing to elongate the shelf life by reducing spoilage bacteria under refrigeration stage while the secondary objective of the study was to determine the most effective chlorinated antimicrobial to be applied in poultry processing plants to reduce spoilage bacteria. For each experiment, a complete randomized design was used. The general linear model procedure was used to determine the effects of brining and chlorine antimicrobials on the Psychrotrophic bacterial load of individually quick frozen (IQF) chicken portions. Simultaneously, a quadratic type equation was used to determine the optimal inclusion level of brine in relation to the responses of Psychrotrophic bacterial loads. The results indicated that control samples (0% brine) had higher (P < 0.05) bacterial load than all samples injected with various injection levels. There were significant differences (P < 0.05) between samples injected with 15% and 20% for all major abattoirs combined. However, there were no differences (P > 0.05) between samples injected with 20% and 25% brine, respectively. In addition, there was a significant difference (P < 0.05) in Psychrotrophic bacterial load between the samples treated with 25% and 30% brine inclusion level as well as those treated with 30% and 35% brining levels in all abattoirs. Futhermore, the results of the study also showed that Acidified Sodium Chloride had significantly lower bacterial load than both aqueous chlorine and chlorine dioxide. However, the effect of percentage brining on average Psychotrophic bacterial count had minimum quadratic values of 24.45 – 0.517 brining + 0.805 brining2 with r = 0.995; r2= 0.989, with optimum percentage brining dose being 43.08%. By extension, the result implies that the lowest reduction in spoilage bacteria is attained at 43.08% of brine inclusion level. These findings have implications on the most effective and convenient antimicrobial to be used in chicken abatoirs as well as reduction of psychotrophic bacterial load on individually quick frozen (IQF) chicken portions / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)
239

Caracterização fenotípica e molecular de amostras de Staphylococcus coagulase negativo isoladas de infecções da corrente sanguínea de pacientes de dois hospitais gerais da cidade de São Paulo / Genetic and phenotypic characterization of coagulase negative staphylococci isolated from bloodstream infections in two São Paulo city hospitals

Souza, Alinne Guimarães de [UNIFESP] 29 April 2009 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:49:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-29. Added 1 bitstream(s) on 2015-08-11T03:26:19Z : No. of bitstreams: 1 Publico-154.pdf: 1362092 bytes, checksum: b56e51cd61b6e0026e1f047e7ce95328 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Staphylococcus coagulase negativo (SCoN) são importantes agentes etiológicos responsáveis por infecções relacionadas à assistência à saúde (IrAS) em infecções da corrente sanguínea. Em estudo retrospectivo foram avaliados SCoN isolados de pacientes com IrAS da corrente sanguínea em dois hospitais gerais da cidade de São Paulo no período de agosto de 2005 à agosto de 2007.Os isolados foram caracterizados a nível de espécies e testes de suscetibilidade aos antimicrobianos pelo Vitek® system e Vitek® 2. A presença do gene mecA e o tipo de SCCmec foram determinados por PCR multiplex. Staphylococcus epidermidis foi a espécie predominante seguido de S. hominis, S. haemolyticus, S. simulans, S. warneri, S. capitis e S. auricularis. Observou-se 88,2% de resistência à oxacilina nos isolados com 100% de concordância entre os discos de oxacilina e cefoxitina confirmados pelo gene mecA. Todos isolados foram suscetíveis à vancomicina e quatro isolados apresentaram resistência intermediária à teicoplanina pelo Etest®. Um S. epidermidis mostrou-se resistente à linezolida. O tipo de SCCmec predominante foi o tipo III seguido pelos tipos IV, I, II e V. Em 26,9% dos isolados mecA positivo não foram caracterizados nenhum tipo de SCCmec pelo protocolo utilizado. / Coagulase negative staphylococci (CoNS) are important etiologic agents responsible for healthcare related infection (HCRI) in bloodstream infections. In a retrospective study we evaluate CoNS isolated from patients with HCRI in bloodstream infections admitted to two general hospitals at São Paulo city, from August 2005 to August 2007. The isolates were characterized at species level and antimicrobial susceptibility tested by the Vitek® system and ViteK® 2. Oxacillin resistance was evaluated by oxacillin and cefoxitin discs. The presence of mecA gene and the SCCmec type were determined by multiplex PCR. Staphylococcus epidermidis was the predominant specie followed by S. hominis, S. haemolyticus, S. simulans, S. warneri, S. capitis and S. auricularis. Oxacillin resistance was observed in 88.2% of the isolates with 100% concordance between oxacilin and cefoxitin discs confirmed by mecA gene. All isolates were susceptible to vancomycin and four isolates revealed intermediate resistance to teicoplanin by Etest®. One S. epidermidis showed resistance to linezolide. The predominant SCC type was the type III followed by the types IV, I, II and V. In 26.9% positive mecA isolates we did not characterize the SCCmec type by the molecular protocol utilized. / TEDE / BV UNIFESP: Teses e dissertações
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Desenvolvimento, aplicação e avaliação de um programa nacional de educação a distância para profissionais da área da saúde sobre resistência microbiana e uso racional de antimicrobianos / A national wide web-based course for healthcare professionals on antimicrobial resistance and rational antimicrobial use

Guerra, Carla Morales [UNIFESP] 25 August 2010 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:49:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-25. Added 1 bitstream(s) on 2015-08-11T03:26:26Z : No. of bitstreams: 1 Publico-277.pdf: 1313299 bytes, checksum: d9efa7c459ef573a430330551e19f390 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Introdução: A educação e a atualização dos profissionais da área da saúde devem ser consideradas fundamentais como estratégias para o controle da resistência microbiana e a garantia da segurança na assistência aos pacientes. Objetivos: Produzir um programa nacional de ensino a distância sobre medidas de prevenção e controle da resistência microbiana em serviços de saúde e avaliar o impacto da aplicação desse programa no conhecimento de profissionais da área de saúde. Avaliar a percepção e atitude de profissionais que atuam em comissões de controle de infecção sobre o programa de controle de infecção em suas instituições. Método: O estudo foi realizado na Comissão de Epidemiologia Hospitalar da Disciplina de Infectologia e Departamento de Informática e Saúde da Universidade Federal de São Paulo. Foi aplicada metodologia a distância utilizando a plataforma Moodle. Foram desenvolvidos dois cursos: RMcontrole, período entre 15 de outubro e 14 de dezembro de 2007, direcionado a profissionais da área da saúde em geral e ATMracional, período de 18 de fevereiro a 18 de abril de 2008, direcionado a profissionais prescritores de antimicrobianos (médicos e dentistas). Os profissionais deveriam inscrever-se pelo site do curso. A seleção dos alunos priorizou profissionais das regiões Centro-Oeste e Norte do país com atuação na área de controle de infecção hospitalar. O curso foi oferecido gratuitamente aos profissionais e financiado pela Organização Pan-Americana da Saúde e Agência Nacional de Vigilância Sanitária. O programa envolveu a produção de uma mídia impressa, um CD-ROM, enviados para o endereço do profissional, além da criação de site na internet. As atividades de cada aluno foram monitoradas por tutores especialistas no controle de infecção hospitalar e para a aprovação no curso foi exigida pontuação de 70% nas atividades e nas avaliações propostas. As avaliações dos alunos foram realizadas no final de cada módulo e no final do curso. Um questionário foi aplicado para obtenção de dados demográficos e epidemiológicos de cada profissional. Resultados: O total de profissionais inscritos para o curso RMcontrole foi 6256 e para o curso ATMracional foi 2856, dentre os quais foram selecionados 1172 e 917 profissionais para cada curso, respectivamente. A taxa de desistência no curso RMcontrole foi de 9,1% e no curso ATMracional foi de 8,0%, a taxa de aprovação foi 96,4% e 93,5%, respectivamente. Para a maioria dos participantes esta foi a primeira participação em um curso a distância, porém poucos referiram dificuldades com o estudo via internet. A ferramenta de estudo preferida pela maioria dos profissionais foi a apostila impressa, mas aproximadamente 20,0% dos profissionais preferiram estudar via internet. A avaliação dos participantes sobre o conteúdo do curso mostrou que, em relação à abrangência e atualização do tema, mais de 95,5% ficaram satisfeitos ou muito satisfeitos. Análise das pontuações em ambos os cursos mostrou que houve diferença entre as notas iniciais e finais, permitindo-nos concluir que houve aquisição de conhecimento (p< 0,001). Conclusões: Este foi o primeiro curso nacional, gratuito, para treinamento de profissionais da área da saúde sobre resistência microbiana. Acreditamos que o aprimoramento desta metodologia permitirá o acesso ao conhecimento técnico a um grupo maior número de profissionais e poderá se transformar em um importante instrumento de formação na área de prevenção e controle de infecções relacionadas à assistência à saúde e no enfrentamento aos desafios da resistência microbiana. A avaliação da percepção e atitude de profissionais que atuam em comissões de controle de infecção sobre o programa de controle de infecção em suas instituições destacou informações importantes que poderão ser utilizadas pelas autoridades brasileiras para direcionar estratégias de melhoria dos programas de controle de infecção hospitalar de cada região do país. / Background: Education and updating of health professionals should be considered as an integral part of strategies to resistance control and to maintain quality of care and patient safety. Objective: To develop and apply a Web-based program on infection control practices and antimicrobial resistance for healthcare workers involved with healthcare-acquired infection from different demographic Brazilian regions, and to assess the knowledge and perceptions of participants. To evaluate the perception and attitude of professionals working in committees hospital infection control registered for the course of the infection control program in their institutions. Method: The study was conducted at the Division of Infectious Diseases and Department of Informatics and Health of Federal University of São Paulo. Were developed and implemented two courses: RMcontrole, directed to health professionals in general and ATMracional, directed only antimicrobial prescribers (physicians and dentists). Professionals should register on line in the site of the course. The selection of students prioritized professionals from the Midwest and North of the country involved in the area of hospital infection control. The course was offered free to the professionals. The program involved production of a printed booklet and a CD-ROM sent to the address of work, beyond the creation of website. One of the features of this work was the use of e-learning platform Moodle. The activities of each student tutors were monitored by specialists in hospital infection control and to pass the course was required score of 70% in the proposed activities and assessments. Results: The total number of professionals registered for the course RMcontrole was 6256 and the course was ATMracional 2856, among whom were selected in 1172 and 917 professionals for each course respectively. The dropout rate in the course RMcontrole was 9.1% and ATMracional was 8.0%, the approval rate was 96.4% and 93.5% and disapproval rate was 3.6% and 6.5 %, respectively. For most participants this was the first participation in a distance course even so, few students reported difficulties with the study via the Internet. The study tool preferred by most professional was the book printed, but approximately 20.0% of professionals reported prefer to study via the Internet. The assessment of participants on the course content showed that in relation to the scope and update more than 95.5% were satisfied or extremely satisfied. The discussions between tutors and participants surpassed the mark of 1,000 posts in each course. Analysis of the scores in both courses showed that there was difference between the initial and final notes, allowing us to conclude that there was knowledge acquisition (p <0.001). Conclusion: This was the first free national program for training health professionals on microbial resistance. We believe that the improvement of this methodology will allow access to technical knowledge to a broader number of professionals and may become an important tool for training in prevention and control of infections related to health care and in facing the challenges of antimicrobial resistance. The evaluation of the perception and attitude of professionals working in infection control committees on the program of infection control in their institutions highlighted important information that could be used by the Brazilian authorities to direct strategies to improve the programs of hospital infection control in each region of the country. / TEDE / BV UNIFESP: Teses e dissertações

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