<p>Silver was used for its antimicrobial effect by the ancient Greeks, long before the existence of microorganisms were first suspected. Nowadays a wide range of antimicrobial dressings containing silver, either incorporated within or applied on the dressings, are available for clinical use. This type of dressings is designed to provide the antimicrobial activity of silver in a more convenient application.</p><p>The aim with this master thesis was to evaluate if silver release and antimicrobial effect of nine silver containing dressings are dependent on the test medium and if there is any relation between silver release and antimicrobial effect.</p><p>Release of silver and antimicrobial effect was evaluated by using a 6-well co-culture system, with inoculated test medium in the wells and dressing pieces in the culture well inserts. Three different test media with increased complexity and nutrient value were inoculated with either</p><p>Results show that release of silver depends on the test fluid used; for phosphate buffered saline (PBS), the silver concentration was as most 1.2 ppm, but for a complex media containing calf serum (SWF), it varied from 9 ppm to 134 ppm. The viable counts in PBS were reduced by at least 3 log units for all dressings and bacteria, whereas in SWF there were no reduction and instead growth was observed. In general, a high release resulted in less bacterial growth. Results also indicated that kinetics of silver release affect the antimicrobial effect. It is likely to assume that it is important for a dressing to release silver quickly.</p><p>It has previously not been possible to correlate silver release of wound care dressings and antimicrobial effect, since the two factors have been measured in different test systems and in different media. Since both factors depend on test medium and method used, it is shown in the present study that it is important to use relevant test medium for in-vitro evaluation. When measuring silver release and antimicrobial effect in the same test system, a relation is found.</p>

Silver was used for its antimicrobial effect by the ancient Greeks, long before the existence of microorganisms were first suspected. Nowadays a wide range of antimicrobial dressings containing silver, either incorporated within or applied on the dressings, are available for clinical use. This type of dressings is designed to provide the antimicrobial activity of silver in a more convenient application. The aim with this master thesis was to evaluate if silver release and antimicrobial effect of nine silver containing dressings are dependent on the test medium and if there is any relation between silver release and antimicrobial effect. Release of silver and antimicrobial effect was evaluated by using a 6-well co-culture system, with inoculated test medium in the wells and dressing pieces in the culture well inserts. Three different test media with increased complexity and nutrient value were inoculated with either Results show that release of silver depends on the test fluid used; for phosphate buffered saline (PBS), the silver concentration was as most 1.2 ppm, but for a complex media containing calf serum (SWF), it varied from 9 ppm to 134 ppm. The viable counts in PBS were reduced by at least 3 log units for all dressings and bacteria, whereas in SWF there were no reduction and instead growth was observed. In general, a high release resulted in less bacterial growth. Results also indicated that kinetics of silver release affect the antimicrobial effect. It is likely to assume that it is important for a dressing to release silver quickly. It has previously not been possible to correlate silver release of wound care dressings and antimicrobial effect, since the two factors have been measured in different test systems and in different media. Since both factors depend on test medium and method used, it is shown in the present study that it is important to use relevant test medium for in-vitro evaluation. When measuring silver release and antimicrobial effect in the same test system, a relation is found.

A utilização de substitutos ósseos para recuperação da função perdida é uma constante busca dentro da área médica. Por isso os biomateriais têm recebido uma atenção muito grande por parte da comunidade científica, dentre eles os materiais a base de fosfato de cálcio. A hidroxiapatita, Ca10 (PO4)6 (OH) 2, tem sido muito estudada, pois além de representar a constituição da massa dos ossos naturais e dentes em 30 a 70%, possui propriedades de bioatividade e osteocondutividade, favorecendo e auxiliando o crescimento do tecido ósseo. Em contrapartida, infecções bacterianas podem surgir após o implante ocasionando a perda da funcionalidade a curto e médio prazo. Várias alternativas estão sendo testadas, geralmente associadas ao uso de antibióticos convencionais incorporados aos biomateriais. Uma alternativa a tais antibióticos seria a utilização de metais que possuem propriedades antibacterianas. A prata (Ag) é conhecida como um metal bactericida e por isso ganhou lugar de destaque dentre os estudos como um aliado importante no controle das infecções pós-cirúrgicas. Este trabalho teve como objetivo sintetizar, caracterizar e avaliar o efeito antimicrobiano da adição de íons de prata em hidroxiapatita. Foram obtidos pós de hidroxiapatita contendo prata (HAAg), nas concentrações de 0,1M; 0,01M e 0,001M pelo método de precipitação em temperatura ambiente e por imersão do pó de hidroxiapatita em soluções aquosas. As fases cristalinas e os grupamentos iônicos foram analisados para cada condição por técnicas de difração de raios X (DRX) e espectroscopia no infravermelho (IV) respectivamente. As informações sobre a morfologia e identificação de elementos químicos foi realizado pela técnica de microscopia eletrônica de varredura com espectroscopia de energia dispersiva (MEV EDS). As avaliações antimicrobianas foram realizadas por ensaios qualitativos e quantitativos, o ensaio qualitativo utilizou o teste de halo de difusão em disco para Staphylococcus aureus e Escherichia coli e o ensaio quantitativo utilizou contagem de bactérias para as cepas de Staphylococcus aureus. Os resultados de DRX e IV indicaram que independentemente do método de obtenção da HAAg foi possível observar a presença de prata metálica caracterizada pelos picos em 2&theta;=38,1º e 44,3º nas amostras HAAg0,1Im, HAAg0,1Pr e HAAg0,01Pr. Observou-se também a presença de AgO, correspondente ao pico em 2&theta;=37,5º nas amostras de HAAg0,01Pr e HAAg0,001Pr. Nos espectros de IV estão presentes as bandas que caracterizam a fase HA, referentes aos grupamentos PO43-, OH- e CO32-. Analisados em conjunto os ensaios qualitativos e quantitativos, as amostras HAAg0,01Im e HAAg0,001Im sintetizadas por imersão indicaram os melhores resultados para o ensaio de disco difusão, por apresentarem formação de halo inibição do crescimento bacteriano para a bactéria S. aureus. Para os ensaios quantitativos as amostras obtidas por precipitação com concentrações 0,1M e 0,01M de prata apresentaram melhor resultado por inibirem o crescimento bacteriano para as cepas S. aureus. / The use of bone substitutes for recovery of lost function is a constant search within the medical field. So biomaterials have received a very large attention from the scientific community, including the materials the basis of calcium phosphate. Hydroxyapatite, Ca10(PO4)6(OH)2, has been studied as apart from representing the natural constitution of the mass of bones and teeth in 30 to 70 % , has properties of bioactivity and osteoconductivity, encouraging and assisting the growth of bone tissue. In contrast, bacterial infections can arise after implantation causing the loss of functionality in the short and medium term. Several alternatives are being tested, usually associated with the use of conventional antibiotics incorporated into biomaterials. An alternative would be to use antibiotics such metals that possess antibacterial properties. Silver (Ag) is known as a bactericidal metal and so gained a prominent place among the studies as an important ally in the control of post- surgical infections. This study aimed to synthesize, characterize and evaluate the antimicrobial effect of adding silver ions into hydroxyapatite. Were obtained hydroxyapatite powders containing silver (Haag) at concentrations 0,1M; 0,01M and 0,001M by the precipitation method at room temperature and by immersion the hydroxyapatite powder in aqueous solutions of AgNO3. The crystalline phases and the ionic groups were analyzed for each condition by techniques of X-ray diffraction (XRD) and infrared spectroscopy (IR) respectively. The information on the morphology and identification of chemical elements was performed by the technique of scanning electron microscopy with energy dispersive spectroscopy (SEM EDS). The antimicrobial evaluations were carried out by qualitative and quantitative assays, the assay used a qualitative diffusion halo disk test for Staphylococcus aureus, Escherichia coli and quantitative assay employed bacteria count for Staphylococcus aureus strains. The results of XRD and IR indicated that regardless of the method of obtaining Haag was possible to observe the presence of metallic silver characterized by peaks in 2&theta;=38,1º and 44,3º in HAAg0,1Im samples, HAAg0,1Pr and HAAg0,01Pr. It also observed the presence of AgO, corresponding to the peak in 2&theta;=37,5º in samples HAAg0,01Pr and HAAg0,001Pr. In the IR spectra are present bands that characterize the HA phase, referring to groups PO43-, OH- and CO32-. Taken together qualitative and quantitative assays, and HAAg0,01Im HAAg0,001Im synthesized by soaking samples showed the best results for the disk diffusion test by presenting halo formation bacterial growth inhibition for S. aureus. For quantitative assays, the samples obtained by precipitation with concentrations 0,1M and 0,01M silver showed better results by inhibiting bacterial growth for Staphylococcus aureus strains.

Fitoterapija (gr. phyton – augalas, therapeia – gydymas) – tai ligų profilaktika ir gydymas, vartojant augalų dalis ar jų preparatus. Nuo seno lietuvių liaudies medicinoje gerai žinomi sidabražolinių (Potentilla) genties augalai. Lietuvoje auga 17 Potentilla genties augalų rūšių, kai kurios iš jų kultūrinės. Šio darbo tikslas yra atlikti biologiškai veiklių medžiagų – flavonoidų ir raugų – išskyrimą iš Potentilla genties augalų (Potentilla anserina L., Potentilla erecta L., Potentilla fruticosa L.) nustatyti veikliųjų medžiagų kiekio kitimus skirtingu augalų vegetacijos metu (birželio – rugsėjo mėnesiais) ir atlikti šių augalinių žaliavų antioksidacinio bei antimikrobinio poveikio tyrimus. Tyrimo medžiaga ir metodai. Tyrime naudota Potentilla genties augalinė žaliava surinkta Šiaulių rajone, Gruzdžių miške (P.anserina žolė, P.erecta šakniastiebiai ir žolė) bei Šiaulių universiteto botanikos sode (P.fruticosa žolė). Permanganatometrinio titravimo metodu buvo nustatytas rauginių medžiagų kiekis tirtuose Potentilla genties augalinėse žaliavose. Naudojant parūgštintą vandenilio chlorido rūgštimi 70% etanolį ir 70% etanolį spektrofotometriniu ir efektyviosios skysčių chromatografijos (ESC) metodu buvo nustatyti bendri flavonoidų kiekiai tirtose augalinėse žaliavose. Antioksidaciniam aktyvumui įvertinti buvo taikomas fotometrinis 2,2-difenil-1-pikrilhidrazilo (DPPH•) laisvojo radikalo sujungimo metodas. Antimikrobinis poveikis įvertintas atliekant tyrimus su triptozės sojos agare 2... [toliau žr. visą tekstą] / Phytotherapy (Greek origin phyton – plant, therapeia – treatment) means the prevention of disease and medical treatment using parts of plants or their extracts. Since ancient times Cinquefoil (Potentilla) family plants have been well-known in Lithuanian non-traditional medicine, comprising over 17 species, some of them are cultivated. Aims and Objectives. To extract biologically active substances – flavonoids and tannins – from Potentilla plants (Potentilla anserina L., Potentilla erecta L., Potentilla fruticosa L.) in order to determine the quantity changes at different times of plant vegetation (June – September), and to research antioxidant and antibacterial effect of those plants. Materials and Methods. Potentilla raw material was collected in the region of Šiauliai, Gruzdžiai forest (Herba Potentillae anserinae, Rhizoma et herba Potentillae erectae) and Šiauliai University Botanical Garden (Folium cum flore Potentillae fruticosae). Permanganatometric titration method was used to find out how much tannin the selected Potentilla contained. Also, spectrophotometric and HPLC methods allowed to measure flavonoid while using 70% of ethanol with hydrochloric acid and 70% of ethanol in the raw vegetation. To evaluate the anti-oxidizing activity photometric 2,2-difenil-1-pikrilhydrosil (DPPH•) free radical method was applied. Antibacterial impact was evaluated with triptosis on soya crop in a hangar for 24 hours at 35 - 37º C using cultivated microorganisms. Results. The tested... [to full text]

A utilização de substitutos ósseos para recuperação da função perdida é uma constante busca dentro da área médica. Por isso os biomateriais têm recebido uma atenção muito grande por parte da comunidade científica, dentre eles os materiais a base de fosfato de cálcio. A hidroxiapatita, Ca10 (PO4)6 (OH) 2, tem sido muito estudada, pois além de representar a constituição da massa dos ossos naturais e dentes em 30 a 70%, possui propriedades de bioatividade e osteocondutividade, favorecendo e auxiliando o crescimento do tecido ósseo. Em contrapartida, infecções bacterianas podem surgir após o implante ocasionando a perda da funcionalidade a curto e médio prazo. Várias alternativas estão sendo testadas, geralmente associadas ao uso de antibióticos convencionais incorporados aos biomateriais. Uma alternativa a tais antibióticos seria a utilização de metais que possuem propriedades antibacterianas. A prata (Ag) é conhecida como um metal bactericida e por isso ganhou lugar de destaque dentre os estudos como um aliado importante no controle das infecções pós-cirúrgicas. Este trabalho teve como objetivo sintetizar, caracterizar e avaliar o efeito antimicrobiano da adição de íons de prata em hidroxiapatita. Foram obtidos pós de hidroxiapatita contendo prata (HAAg), nas concentrações de 0,1M; 0,01M e 0,001M pelo método de precipitação em temperatura ambiente e por imersão do pó de hidroxiapatita em soluções aquosas. As fases cristalinas e os grupamentos iônicos foram analisados para cada condição por técnicas de difração de raios X (DRX) e espectroscopia no infravermelho (IV) respectivamente. As informações sobre a morfologia e identificação de elementos químicos foi realizado pela técnica de microscopia eletrônica de varredura com espectroscopia de energia dispersiva (MEV EDS). As avaliações antimicrobianas foram realizadas por ensaios qualitativos e quantitativos, o ensaio qualitativo utilizou o teste de halo de difusão em disco para Staphylococcus aureus e Escherichia coli e o ensaio quantitativo utilizou contagem de bactérias para as cepas de Staphylococcus aureus. Os resultados de DRX e IV indicaram que independentemente do método de obtenção da HAAg foi possível observar a presença de prata metálica caracterizada pelos picos em 2&theta;=38,1º e 44,3º nas amostras HAAg0,1Im, HAAg0,1Pr e HAAg0,01Pr. Observou-se também a presença de AgO, correspondente ao pico em 2&theta;=37,5º nas amostras de HAAg0,01Pr e HAAg0,001Pr. Nos espectros de IV estão presentes as bandas que caracterizam a fase HA, referentes aos grupamentos PO43-, OH- e CO32-. Analisados em conjunto os ensaios qualitativos e quantitativos, as amostras HAAg0,01Im e HAAg0,001Im sintetizadas por imersão indicaram os melhores resultados para o ensaio de disco difusão, por apresentarem formação de halo inibição do crescimento bacteriano para a bactéria S. aureus. Para os ensaios quantitativos as amostras obtidas por precipitação com concentrações 0,1M e 0,01M de prata apresentaram melhor resultado por inibirem o crescimento bacteriano para as cepas S. aureus. / The use of bone substitutes for recovery of lost function is a constant search within the medical field. So biomaterials have received a very large attention from the scientific community, including the materials the basis of calcium phosphate. Hydroxyapatite, Ca10(PO4)6(OH)2, has been studied as apart from representing the natural constitution of the mass of bones and teeth in 30 to 70 % , has properties of bioactivity and osteoconductivity, encouraging and assisting the growth of bone tissue. In contrast, bacterial infections can arise after implantation causing the loss of functionality in the short and medium term. Several alternatives are being tested, usually associated with the use of conventional antibiotics incorporated into biomaterials. An alternative would be to use antibiotics such metals that possess antibacterial properties. Silver (Ag) is known as a bactericidal metal and so gained a prominent place among the studies as an important ally in the control of post- surgical infections. This study aimed to synthesize, characterize and evaluate the antimicrobial effect of adding silver ions into hydroxyapatite. Were obtained hydroxyapatite powders containing silver (Haag) at concentrations 0,1M; 0,01M and 0,001M by the precipitation method at room temperature and by immersion the hydroxyapatite powder in aqueous solutions of AgNO3. The crystalline phases and the ionic groups were analyzed for each condition by techniques of X-ray diffraction (XRD) and infrared spectroscopy (IR) respectively. The information on the morphology and identification of chemical elements was performed by the technique of scanning electron microscopy with energy dispersive spectroscopy (SEM EDS). The antimicrobial evaluations were carried out by qualitative and quantitative assays, the assay used a qualitative diffusion halo disk test for Staphylococcus aureus, Escherichia coli and quantitative assay employed bacteria count for Staphylococcus aureus strains. The results of XRD and IR indicated that regardless of the method of obtaining Haag was possible to observe the presence of metallic silver characterized by peaks in 2&theta;=38,1º and 44,3º in HAAg0,1Im samples, HAAg0,1Pr and HAAg0,01Pr. It also observed the presence of AgO, corresponding to the peak in 2&theta;=37,5º in samples HAAg0,01Pr and HAAg0,001Pr. In the IR spectra are present bands that characterize the HA phase, referring to groups PO43-, OH- and CO32-. Taken together qualitative and quantitative assays, and HAAg0,01Im HAAg0,001Im synthesized by soaking samples showed the best results for the disk diffusion test by presenting halo formation bacterial growth inhibition for S. aureus. For quantitative assays, the samples obtained by precipitation with concentrations 0,1M and 0,01M silver showed better results by inhibiting bacterial growth for Staphylococcus aureus strains.

This diploma thesis is focused on the study of the effect of ultraviolet radiation and titanium dioxide on the yeast Candida vini. Photocatalytic inactivation of this yeast was performed on various types of titanium dioxide films, which were immobilized on soda lime glasses. Acridine orange was used as a dye to distinguish live and dead yeast cells after certain irradiation time. Live and dead cells emit different light in colour after staining in acridine orange. Candida vini photocatalytic inactivation depends on the amount of titanium dioxide immobilized on glass as well as on the structure of its surface if the lamp intensity remains the same. Kinetics of this photocatalytic process was studied, too.

Access to fresh water is a human right, yet more than 780 million people, especially in rural areas, rely on unimproved sources and the need for finding ways of treating water is crucial. Although the use of natural coagulant protein in drinking water treatment has been discussed for a long time, the method is still not in practice, probably due to availability of material and limited knowledge. In this study, about hundred different crude extracts made from plant materials found in Southern India were screened for coagulation activity. Extracts of three Brassica species (Mustard, Cabbage and Cauliflower) were showing activity comparable to that of Moringa oleifera and were further investigated. Their protein content and profile were compared against each other and with coagulant protein from Moringa. Mustard (large) and Moringa seed proteins were also studied for their effect against clinically isolated bacterial strains. The protein profiles of Brassica extract showed predominant bands around 9kDa and 6.5kDa by SDS-PAGE. The peptide sequence analysis of Mustard large identified the 6.5kDa protein as Moringa coagulant protein (MO2.1) and the 9kDa protein band as seed storage protein napin3. Of thirteen clinical strains analysed, Moringa and Mustard large were proven effective in either aggregation activity or growth kinetic method or both in all thirteen and nine strains respectively. To my knowledge this is the first report on the presence of coagulant protein in Brassica seeds. Owing to the promising results Brassica species could possibly be used as a substitute to Moringa coagulating agent and chemicals in drinking water treatment. / <p>QC 20121214</p>

Infections caused by antibiotic resistant pathogenic bacteria is an increasing issue inhealthcare, and development of new antimicrobial substances could contribute to combat the continued spread. Plants have historically been used in traditional medicine, have intrinsic defense mechanisms against microbes, and could therefore be a source for new antimicrobial agents. At the Department of Chemistry and Biomedicine at Linnaeus University, Kalmar, a total of 18 extracts made from 9 different combinations of Swedish-growing plants were available.The purpose of the current thesis was to investigate possible antimicrobial effects of the plant extracts in vitro, on a selection of Gram-positive (n=3) and Gram-negative (n=4) bacterial strains. Initial screening of all 18 extracts was performed with agar-based methods including agar well diffusion and direct application on inoculated agar. Detection of concentration-dependent antimicrobial effects was performed with four extracts on Staphylococcus aureus and Enterococcus faecalis. At inhibitory concentrations, viability was estimated as colony forming units/ml (CFU/ml).Screening showed that 11 of 18 extracts affected the growth of at least one of the strains tested. Gram-positive species were affected to a greater extent than Gram-negatives. Estimation of concentration dependency showed inhibitory effects at 50 mg/l in the most potent extracts. Viability estimation revealed an average reduction for both S. aureus and E. faecalis, as compared to the positive control. In conclusion, the study showed possible antimicrobial effects of several extract-bacteria combinations, disclosing potential substances for further investigations.