Papers by Keyword: Antimicrobial Effect

Abstract: Copper is a superior antibacterial metal, which is used for various antibacterial products. It is known that the antimicrobial property is generated by direct contact of bacterial cell to the copper surface. Since porous copper has a benefit to increase the surface area contacted to atmospheric medium, it is expected that antibacterial effect can be enhanced. Two kinds of lotus-type porous copper with different directional open pores were used as samples. In order to elucidate such enhancement, four kinds of culture tests on porous copper plates were carried out using bacteria of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella enteritidis. While the counts of viable bacteria of Staphylococcus aureus and Escherichia coli cultured on non-porous copper do not change significantly, the counts of Pseudomonas aeruginosa and Salmonella enteritidis decreases. The counts of the viable bacteria of Staphylococcus aureus and Escherichia coli cultured on porous copper drastically decrease, while the counts of Salmonella enteritidis decreases to some degree. However, the porosity does not affect the decrease of counts of Pseudomonas aeruginosa. Thus, apparent antibacterial property of porous copper is attributed to increase of contact area of the bacteria to porous copper for Staphylococcus aureus, Escherichia coli and Salmonella enteritidis.

Abstract: In this study we investigated the possibility to use in implantology of a new composite made from antibiotic imbedded in polymer matrix with goal to merge the mechanical advantages of the metallic substrate with the excellent corrosion protection of the polymer and antimicrobial effect of the antibiotics. Furthermore the addition of small quantity of bioactive glass allows the antibiotic release and hastens the osteointegration. The biological properties of the coatings were tested including the microbial viability using Gram - and Gram + bacterial strains with known antibiotic susceptibility behavior. The proposed system could be used for development of new antimicrobial materials or strategies for fighting medical biofilm pathogens often implicated in the occurrence of chronic infections.

Abstract: The aim was to research the antimicrobial effect of the extracts of Fruits of Herba Leonuri with different solvents on the common plant microbes. The bacteria cake method was used to study the antimicrobial capability of Fruits of Herba Leonuri. The extracts have anti-bacterial action on Rhixoctonia cerealis, Fusarium gram inearum, Rhizoctonia solani and Setosphaeria turcica, especially the extract from distilled water has the strongest anti-bacterial action on Rhixoctonia cerealis and Fusarium gram inearum, the extract from ether has the strongest anti-bacterial action on Fusarium gram inearum, the MIC all were 10 mg/ml The extracts had different antimicrobial effect when pH value was from 5 to 8. The extracts of Fruits of Herba Leonuri could inhibit the 4 pathogenic microorganism, and the antibacterial activity was affected by pH value greatly.

Abstract: Silver-doped silica gel was prepared by the reaction of colloidal silica and AgNO3. In the synthetic process, aluminum ions promote the chemical durability of silver-doped silica gel with dramatically decreasing the elusion of silica ions at the aqueous solution. Especially, aluminum ions induce slow release silver ion of silver-doped silica gel over a long period of time. Also, antimicrobial effects evaluated using a shake flask method resulted in a disinfection ratio of Staphylococcus aureus(ATCC 6538) and Escherichia coli(ATCC 25922) of over 99.9%, indicating high anti-microbial properties.

Abstract: Antibacterial effects of three powdered bioactive glasses were compared by measuring the pH of the simulated body fluid in immediate contact with the glass powder particles and by cultivating four microorganisms in the powder-solution mixtures. After individual cultivation with the microorganisms the bioactive glasses showed ability to kill bacteria, but the effects were very dependent on glass composition and on the microorganism as well as on cultivation time. The results indicated that antimicrobial property of bioactive glasses correlates with their ability to change the pH of the body fluid in immediate contact with the glass. However, the increase in pH is not the only factor influencing the antimicrobial properties.

Abstract: Ag doped Hydroxyapatites (Ag-HAp) was prepared through either ion exchange or coprecipitation to compare the durability of antimicrobial effect. In case of ion exchanged Ag-HAp, the microbials reproliferated after 100 h, in spite of the rapid reduction of E.Coli during the initial moment. On the contrary, coprecipitated Ag-HAp effectively suppressed the reproliferation until 1000 h. The difference in durability depending on synthesis route was analysed with respect to the amount of silver released at each interval. In case of ion exchanged Ag-HAp, more than 60% of overall silver was released during initial 10 minitues. On the contrary, coprecipitated Ag-HAp released less than 40% of overall silver during the same period, meaning the comparatively uniform release behavior.