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Sample records for strong antibacterial effect

  1. Strong and Nonspecific Synergistic Antibacterial Efficiency of Antibiotics Combined with Silver Nanoparticles at Very Low Concentrations Showing No Cytotoxic Effect.

    Science.gov (United States)

    Panáček, Aleš; Smékalová, Monika; Kilianová, Martina; Prucek, Robert; Bogdanová, Kateřina; Večeřová, Renata; Kolář, Milan; Havrdová, Markéta; Płaza, Grażyna Anna; Chojniak, Joanna; Zbořil, Radek; Kvítek, Libor

    2015-12-28

    The resistance of bacteria towards traditional antibiotics currently constitutes one of the most important health care issues with serious negative impacts in practice. Overcoming this issue can be achieved by using antibacterial agents with multimode antibacterial action. Silver nano-particles (AgNPs) are one of the well-known antibacterial substances showing such multimode antibacterial action. Therefore, AgNPs are suitable candidates for use in combinations with traditional antibiotics in order to improve their antibacterial action. In this work, a systematic study quantifying the synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was performed. Employing the microdilution method as more suitable and reliable than the disc diffusion method, strong synergistic effects were shown for all tested antibiotics combined with AgNPs at very low concentrations of both antibiotics and AgNPs. No trends were observed for synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs, indicating non-specific synergistic effects. Moreover, a very low amount of silver is needed for effective antibacterial action of the antibiotics, which represents an important finding for potential medical applications due to the negligible cytotoxic effect of AgNPs towards human cells at these concentration levels.

  2. Strong and Nonspecific Synergistic Antibacterial Efficiency of Antibiotics Combined with Silver Nanoparticles at Very Low Concentrations Showing No Cytotoxic Effect

    Directory of Open Access Journals (Sweden)

    Aleš Panáček

    2015-12-01

    Full Text Available The resistance of bacteria towards traditional antibiotics currently constitutes one of the most important health care issues with serious negative impacts in practice. Overcoming this issue can be achieved by using antibacterial agents with multimode antibacterial action. Silver nano-particles (AgNPs are one of the well-known antibacterial substances showing such multimode antibacterial action. Therefore, AgNPs are suitable candidates for use in combinations with traditional antibiotics in order to improve their antibacterial action. In this work, a systematic study quantifying the synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was performed. Employing the microdilution method as more suitable and reliable than the disc diffusion method, strong synergistic effects were shown for all tested antibiotics combined with AgNPs at very low concentrations of both antibiotics and AgNPs. No trends were observed for synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs, indicating non-specific synergistic effects. Moreover, a very low amount of silver is needed for effective antibacterial action of the antibiotics, which represents an important finding for potential medical applications due to the negligible cytotoxic effect of AgNPs towards human cells at these concentration levels.

  3. The Effects of Chronic Nitrate Supplementation and the Use of Strong and Weak Antibacterial Agents on Plasma Nitrite Concentration and Exercise Blood Pressure.

    Science.gov (United States)

    McDonagh, S T J; Wylie, L J; Winyard, P G; Vanhatalo, A; Jones, A M

    2015-12-01

    Chlorhexidine-containing mouthwash (STRONG), which disturbs oral microflora, has been shown to diminish the rise in plasma nitrite concentration ([NO2-]) and attenuate the reduction in resting blood pressure (BP) typically seen after acute nitrate (NO3-) ingestion. We aimed to determine whether STRONG and weaker antiseptic agents attenuate the physiological effects of chronic NO3- supplementation using beetroot juice (BR). 12 healthy volunteers mouth-rinsed with STRONG, non-chlorhexidine mouthwash (WEAK) and deionised water (CON) 3 times a day, and ingested 70 mL BR (6.2 mmol NO3-), twice a day, for 6 days. BP (at rest and during 10 min of treadmill walking) and plasma and salivary [NO3-] and [NO2-] were measured prior to and on day 6 of supplementation. The change in salivary [NO3-] 4 h post final ingestion was higher (P0.05). However, during treadmill walking, the increase in systolic and mean arterial BP was higher 4 h after the final nitrate bolus in STRONG compared with CON (P<0.05) but not WEAK. The results indicate that both strong and weak antibacterial agents suppress the rise in plasma [NO2-] observed following the consumption of a high NO3- diet and the former can influence the BP response during low-intensity exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Antibacterial effects and toxigenesis of Penicillium aurantiogriseum ...

    African Journals Online (AJOL)

    The toxigenesis of one Penicillium aurantiogriseum and one Penicillium viridicatum isolates was investigated. Sterile culture filtrates of both fungi had a clear antibacterial effect only against Bacillus subtilis. The effect on B. subtilis varied with amount of filtrate used and temperature. The antibacterial activity of chloroform ...

  5. Antibacterial Effect of Surface Pretreatment Techniques against ...

    African Journals Online (AJOL)

    2018-02-23

    Feb 23, 2018 ... Self-etching adhesive systems with acidic primers demonstrates only limited antibacterial activities because of the buffering effect of dentin tubular fluid and the existence of aciduric bacteria.[42]. Moreover, dentin bonding systems possessing antibacterial activity even after being cured are beneficial for ...

  6. ANTIBACTERIAL EFFECTS OF FRESH AND PRESERVED ROYAL JELLY

    Directory of Open Access Journals (Sweden)

    Zinka Maksimović

    2013-10-01

    Full Text Available Antibacterial effects of the fresh royal jelly, royal jelly stored at 4 °C and -40 °C for a period of 12 months against reference and isolated bacterial strains from the different clinical samples, were tested and compared by the diffusion test. Royal jelly shows antibacterial effects against both tested gram-positive and gram-negative bacteria. Fresh royal jelly has the most effective antibacterial activity. Storage temperature at -40 oC slightly affects antibacterial activity of royal jelly, while storage temperature at 4 oC decreases its antibacterial activity.Key words: royal jelly, antibacterial effects, storage temperature, storage duration

  7. Effects of antibacterial dishwashing liquid on foodborne pathogens and competitive microorganisms in kitchen sponges

    NARCIS (Netherlands)

    Kusumaningrum, H.D.; Putten, van M.M.; Rombouts, F.M.; Beumer, R.R.

    2002-01-01

    In response to increasing concern about home hygiene, the use of antibacterial products to reduce microorganisms in kitchen sponges and cleaning cloths is strongly promoted by some producers of detergent for domestic use. The effects of an antibacterial dishwashing liquid on Escherichia coli,

  8. Antibacterial effects and toxigenesis of Penicillium aurantiogriseum ...

    African Journals Online (AJOL)

    SERVER

    2007-10-18

    Oct 18, 2007 ... Sterile culture filtrates of both fungi had a clear antibacterial effect only against Bacillus subtilis. The effect on B. subtilis ... mycotoxins were identified in the fungal cultures using thin-layer chromatography. P. aurantiogriseum ... Food Microbiology Laboratory collection: Bacillus subtilis, Bacillus megaterium ...

  9. SYNERGISTIC ANTIBACTERIAL EFFECT OF STEM BARK ...

    African Journals Online (AJOL)

    userpc

    ABSTRACT. The study was aimed at screening the stem bark extracts of Faidherbia albida and Psidium guajava for synergistic antibacterial effect against methicillin resistant Staphylococcus aureus (MRSA). The powdered plant materials were extracted with methanol using cold maceration technique and the extracts were ...

  10. Antibacterial Effect of Surface Pretreatment Techniques against ...

    African Journals Online (AJOL)

    2018-02-23

    Feb 23, 2018 ... of dentin chips were obtained from the cavity walls, and the number of bacteria recovered was counted. Kruskal–Wallis ... Keywords: Antibacterial effect, cavity surface pretreatment techniques, cavity preparation, dental, dental ... wavelengths for removing oral soft and dental hard tissues without pain relief, ...

  11. DETECTION OF THE ANTIBACTERIAL EFFECT OF NIGELLA ...

    African Journals Online (AJOL)

    No inhibition was found in the growth of E.Coli and Enterobacter. This was emphasized by using the positive control Ciprofloxacin. The positive inhibition may be attributed to the two important active ingredients of NS, Thymoquinone and melanin. Keywords: Nigella Sativa, antibacterial effect, Staphylococcus aureus, paper ...

  12. Antibacterial effect of polyethyleneimine nanoparticles incorporated in provisional cements against Streptococcus mutans.

    Science.gov (United States)

    Shvero, Dana Kesler; Davidi, Michael Perez; Weiss, Ervin I; Srerer, Nir; Beyth, Nurit

    2010-08-01

    Frequently provisional restorations require long-term permanence in the oral cavity, thus an antibacterial effect is desirable. We hypothesized that this effect may be achieved by incorporating polyethyleneimine (PEI) nanoparticles into provisional cements. The nanoparticles antibacterial effect incorporated at 0.5%, 1%, and 2% w/w into provisional cement, was studied in vitro. The antibacterial effect against Streptococcus mutans and Enterococcus faecalis was tested using direct contact test. The data was analyzed using the ANOVA test, with the Dunnett test for multiple pairwise comparisons. A strong antibacterial effect was evident in all test groups after an aging period of 14 days against S. mutans and E. faecalis (p faecalis (p faecalis for a period of 14 days. The minimum effective concentration suggested is 1% w/w. Incorporation of nanoparticles may prevent caries and inflammation, and thereby improve the results of the prosthetic treatment. Further investigation is necessary on the effect on mechanical properties and clinical relevance.

  13. Effects of antibacterial dishwashing liquid on foodborne pathogens and competitive microorganisms in kitchen sponges.

    Science.gov (United States)

    Kusumaningrum, H D; van Putten, M M; Rombouts, F M; Beumer, R R

    2002-01-01

    In response to increasing concern about home hygiene, the use of antibacterial products to reduce microorganisms in kitchen sponges and cleaning cloths is strongly promoted by some producers of detergent for domestic use. The effects of an antibacterial dishwashing liquid on Escherichia coli, Salmonella Enteritidis, Staphylococcus aureus, and Bacillus cereus were investigated in a modified suspension test and in used sponges with and without food residues under laboratory conditions. A limited study was conducted in households to assess the efficacy of antibacterial dishwashing liquid as used by the consumer. In the suspension tests, S. aureus and B. cereus were shown to be susceptible to low concentrations of antibacterial dishwashing liquid (0.5%), whereas E. coli and Salmonella Enteritidis maintained their initial numbers for at least 24 h at 25 degrees C. At higher concentrations (2 to 4%), all test organisms decreased to below the detection limit after 24 h. Over a 24-h period, the antibacterial dishwashing liquid did not significantly reduce these organisms in used sponges in which food residues were present. The antibacterial product did not reduce the competitive microorganisms either. Similar results were found for sponges involved in daily household use. The results of this study demonstrate that the antibacterial dishwashing liquid was effective in reducing pathogens in the suspension test but not in the used sponges. This finding indicates that to determine the efficacy of antibacterial products, their use in a household setting must be considered.

  14. Effective antibacterials: at what cost? The economics of antibacterial resistance and its control.

    Science.gov (United States)

    White, Anthony R

    2011-09-01

    The original and successful business model of return on investment being sufficiently attractive to the pharmaceutical industry to encourage development of new antibacterial molecules and related diagnostics has been compromised by increasing development costs and regulatory hurdles, resulting in a decreasing chance of success and financial return. The supply of new effective agents is diminishing along with the number of companies engaged in antibacterial research and development. The BSAC Working Party on The Urgent Need:Regenerating Antibacterial Drug Discovery and Development identified the need to establish, communicate and apply the true health and economic value of antibacterials, along with the adoption of meaningful incentives, as part of the future model for antibacterial development. Robust data are needed on the cost of resistance and ineffective treatment of bacterial infection, along with national and local holistic analyses of the cost-benefit of antibacterials. An understanding of the true health and economic value of antibacterials and the cost of resistance across healthcare systems needs to be generated, communicated and used in order to set a pricing and reimbursement structure that is commensurate with value. The development and economic model of antibacterial use needs to be rebuilt based on this value through dialogue with the various stakeholders, including the pharmaceutical industry, and alternative incentives from 'push' to 'pull' and funding models, such as public/private partnerships, agreed. A research and development model that succeeds in developing and delivering new antibacterial agents that address the health needs of society from start to finish, 'from cradle to grave', must be established.

  15. Hemostatic, anti-inflammatory and antibacterial effects of ...

    African Journals Online (AJOL)

    Abstract. Purpose: To study the hemostatic, anti-inflammatory and antibacterial effects of Sanqixiantao dressing. Methods: ... Sanqixiantao extract significantly shortened blood clotting time in vitro (p < 0.01), and showed antibacterial activities against ..... application effect of different silver dressings in treatment of patients ...

  16. Antibacterial effects of Pluchea indica Less leaf extract on E. faecalis and Fusobacterium nucleatum (in vitro

    Directory of Open Access Journals (Sweden)

    Agni Febrina Pargaputri

    2016-06-01

    Full Text Available Background: Enterococcus. faecalis (E. faecalis and Fusobacterium nucleatum (F. nucleatum are the most common bacteria found in infected tooth root canal. Most of these bacteria often cause failure in endodontic treatments. Pluchea indica Less leaf is a species of plants that has several chemical properties. It consists of flavonoids, tannins, polyphenols, and essensial oils which have been reported as antibacterial agents. Because of its benefits, the extract of Pluchea indica Less leaves may be potentially developed as one of root canal sterilization dressing. Purpose: This study aimed to determine antibacterial activity of Pluchea indica Less leaves extract against E. faecalis and F. nucleatum bacteria. Method: Dilution method was conducted first to show Minimum Inhibitory Concentration (MIC of the extract against E. faecalis and F. nucleatum. The antibacterial activity test on Pluchea indica Less leaves extract was performed on E. faecalis and F. nucleatum bacteria using agar diffusion method. The Pluchea indica Less leaves extract used for antibacterial activity test was at a concentrations of 100%, 50%, 25%, 12.5%, and 6.25%. Thirty-five petridiscs were used and divided into five groups based on the extract concentration. Result: The results showed strong and moderate antibacterial effects of the Pluchea indica Less leaves extract on E. faecalis at the concentrations of 100% and 50%, while on F. nucleatum only at the concentration of 100% with moderate effect. Conclusion: Pluchea indica Less leaves extract has antibacterial activity against E. faecalis and F. nucleatum bacteria with strong-moderate effect.

  17. Antibacterial effect of protamine assayed by impedimetry

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Gill, T.; Gram, Lone

    1995-01-01

    estimating the cell number after protamine treatment, rather than colony counts. Protamine from salmon killed growing Gram- positive bacteria and significantly inhibited growth of Gram- negative bacteria in Tryptone Soy Broth (TSB) at 25 degrees C. In general Gram-positive bacteria were more sensitive......Impedimetric measurements were used to assay the antibacterial effect of protamine. A good linear correlation between the impedance detection time and the initial cell counts was obtained (r = 0 . 99, n = 2). As basic peptides may cause clumping of cells, this correlation curve was used when...... to protamine than Gram-negative bacteria; the minimum inhibitory concentrations (MIG) determined for Gram-positive strains varied from 20 to 1000 mu g ml(-1) and for Gram-negative strains from 500 mu g ml(-1) to more than 4000 mu g ml(-1). The effect of protamine on non-growing Listeria monocytogenes Scott...

  18. Study on antibacterial effect of medlar and hawthorn compound ...

    African Journals Online (AJOL)

    This paper is to study the antibacterial effect of medlar and hawthorn compound extract in vitro. Water extract method and ethanol extraction method are adopted to prepare the compound extracts, and disc diffusion method and improved test tube doubling dilution method are adopted to make the antibacterial test to the two ...

  19. Studies on Antibacterial Effect of The Leaves Of Phyllanthus Niruri ...

    African Journals Online (AJOL)

    USER

    Statistical analysis revealed that the mean diameter zones of inhibition for gentamycin was significantly higher than those of the plant extracts at 0.05 level of probability though, 400mg/ml concentration exhibited high antibacterial activities in both extracts. This study has established the antibacterial effect of P. niruri leaves.

  20. Antibacterial effects of Solanum tuberosum peel ethanol extract in vitro

    Directory of Open Access Journals (Sweden)

    Amanpour Raana

    2015-04-01

    Full Text Available Introduction: Today, medicinal plants are being widely used due to being natural, available, and cheaper than synthetic drugs and having minimum side effects. Since there were reports about the antibacterial properties of Solanum tuberosum (SE, the aim of this study was to investigate the antibacterial effects of SE ethanol extract in vitro condition on Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae. Methods: Ethanol extract of SE peel was prepared by maceration method. Initially, antibacterial activity of ethanol extract of SE was qualitatively determined by disk diffusion test; then, the minimum inhibitory concentration and minimum bactericidal concentration were qualitatively determined by micro-dilution method. Results: SE peel extract had antibacterial properties and its effect was more pronounced on gram-positive bacteria, especially S. aureus (0.62±0.00 mg/ml. The extract had antibacterial activity on gram-negative bacteria, P. aeruginosa, too (8.33±2.88 mg/ml. Conclusion: SE peel extract has antibacterial activity and its effect on gram-positive bacteria was more pronounced than the investigated gram-negative bacteria. Therefore, it is suggested that SE peel constituent compounds be determined and to determine the exact mechanism of its antibacterial properties, and more comprehensive research be done to apply it, clinically.

  1. Evaluation of in vitro antibacterial effect of room curing polymethylmethacrylate material adding nano-silver base inorganic antibacterial agents

    International Nuclear Information System (INIS)

    Jia Chunli; Wang Xiaorong; Zhang Citong; Sun Shiqun; Yang Yun

    2012-01-01

    Objective: To investigate the antibacterial effect of room curing polymethylmethacrylate (PMMA) material adding nano-silver base inorganic antibacterial agent and to detect the changes of its mechanical property. Methods: Nano-silver base inorganic antibacterial agent was added to the room curing PMMA material in the range of 0.5% -3.0% at an interval of 0.5% by ball milling specimen. Antibacterial rates of the specimens were detected by film method. Bending strength, impact strength, and wear resistance of the specimens were respectively detected on electronic universal testing machine, impact test machine and friction and wear test machine. Results: The antibacterial rates of Streptococcus mutans and Candida albicans were more than 50% when antibiotics content was 1.0% . The antibacterial rates of Streptococcus mutans and Candida albicans were more than 90% when the antibiotics content was 2.5% . The three mechanical properties were increased compared with control group when the antibacterial agents were in the range of 1.0% -1.5% . Then the three mechanical properties were decreased with the increasing of antimicrobial concentration. When the antibiotics content was 2.0% , the wear resistance had significant difference compared with control group (P<0.05); when the antibiotics content was 2.5% , the bending strength and impact strength had significant difference compared with control group (P<0.05). Conclusion: The antibacterial effect of room curing PMMA adding nano-silver base inorganic antibacterial agent is ideal. The antibacterial rate is increased gradually with the increasing content of antibacterial agents. There is no significant effect on the mechanical properties of room curing PMMA material, but the antibacterial effects are satisfied when the content of antibacterial agents is 2.0% . (authors)

  2. Chemical Composition and Antibacterial Effects of

    Directory of Open Access Journals (Sweden)

    SS Saei Dehkordi

    2009-10-01

    Full Text Available Introduction & Objective: Rosmarinus officinalis L. as a member of the Lamiaceae family and lysozyme as a natural antibacterial agent is important in food microbiology, because of its characteristics. The aim of the present study was to determine the chemical composition and anti-listerial activity of Rosmarinus officinalis essential oil (REO alone and in combination with lysozyme for enhancement of anti-listerial activity of both substances. Materials & Methods: Rosmarinus officinalis L. was purchased from a local grocery store at Shahrekord and was identified by the Institute of Medicinal Plants, ACECR. The air-dried aerial parts were subjected to hydrodistillation using a Clevenger apparatus to obtain essential oil and yielded oil was analyzed by GC/MS. Antibacterial activity (on basis of Minimum Inhibitory Concentration (MIC of REO was studied separately and in combination with unheated lysozyme (L and heat-treated lysozyme (HTL on Listeria monocytogenes at different pH (5, 6 and 7 by a micro-broth dilution assay. The collected data were analyzed by SPSS software. Results: In the current study, 98.05% of constituents of the essential oil were identified. The major components were α-pinene (14.06%, 1,8-cineole (13.62%, verbenone (11.2%, camphor (10.51%, borneol (7.3%, 3-octanone (7.02%, camphene (5.46% and linalool (5.07%. The inhibitory action of REO was stronger at lower pH especially 5 (MIC=225 μg/mL. Inhibition by L at pH 5 was 640 μg/mL but no inhibition was seen at pH 7. HTL resulted in more effective inhibition than L, especially at pH 5 and heat-treatment 80˚C (MIC: 160 μg/mL. Conclusion: Combination of L + REO and particularly HTL + REO was led to enhancement of bacterial inhibition. It was concluded that REO by the identified chemical composition was effective alone or in combination with L or HTL on Listeria monocytogenes as a food-borne pathogen.

  3. Antibacterial Effect of Diclofenac Sodium on Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Amin Salemmilani

    2013-01-01

    Full Text Available Objective: Non-steroidal anti-inflammatory drugs (NSAIDs have shown antibacterial activity in some recent studies. The aim of this study was to evaluate the antibacterial effect of diclofenac against Enterococcus faecalis (E. faecalis as a resistant endodontic bacterium in comparison with ibuprofen, calcium hydroxide and amoxicillin.Materials and Methods: The antibacterial activity of materials was evaluated using agar diffusion test and tube dilution method. Mixtures of 400 mg/ml of materials were prepared. The bacteria were seeded on 10 Muller-Hinton agar culture plates. Thirty microliter of each test material was placed in each well punched in agar plates. After incubation, the zone of bacterial inhibition was measured. Minimum inhibitory concentration (MIC of the test materials was determined by agar dilution method. One-way Analysis of Variance (ANOVA followed by Sidak post hoc test was used to compare the mean zone of microbial growth in the groups.Results: There were significant differences between the two groups (p< 0.05. Results of the agar diffusion test showed that antibiotics (amoxicillin, gentamycin had the greatest antibacterial activity followed by NSAIDs (ibuprofen, diclofenac. Ca(OH2 failed to show antibacterial activity. Diclofenac and ibuprofen showed distinct antibacterial activity against E. faecalis in 50 µg/ml and above concentrations.Conclusion: Within the limitations of this in vitro study, it is concluded that diclofenac and ibuprofen have significantly more pronounced antibacterial activity against E. faecalis in comparison with Ca(OH2.

  4. Antibacterial Effect of Five Zingiberaceae Essential Oils

    Directory of Open Access Journals (Sweden)

    Orapin Kerdchoechuen

    2007-08-01

    Full Text Available Essential oil obtained by hydrodistillation and two different solvent extractions (petroleum ether and ethanol from five Zingiberaceae species: ginger (Zingiber officinale Roscoe., galanga (Alpinia galanga Sw., turmeric (Curcuma longa L., kaempferia (Boesenbergia pandurata Holtt. and bastard cardamom (Amomum xanthioides Wall. was characterized. Volatile components of all extracts were analyzed by gas chromatographymass spectrometry (GC-MS. The major components of ginger, turmeric, galangal, bastard cardamom and kaempferia were zingiberene, turmerone, methyl chavicol, and γ-terpinene, respectively. Their antibacterial effects towards Escherichia coli, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes were tested by a disc diffusion assay. Essential oil of kaempferia and bastard cardamom obtained by hydrodistillation extraction could inhibit growth of all tested bacteria. Essential oil of ginger extracted by hydrodistillation had the highest efficiency against three positive strains of bacteria (S. aureus, B. cereus and L. monocytogenes, with a minimum concentration to inhibit B. cereus and L. monocytogenes of 6.25 mg/mL.

  5. Effect of ionizing radiation on antioxidants and antibacterial activities of Inula Viscasa

    International Nuclear Information System (INIS)

    Rhimi, W.; Issam, B; Saidi, M; Abdennacer, B; Maroua, J

    2015-01-01

    In the present study, the irradiation processing of Tunisian Inula Viscosa samples was carried out at dose of 5 kGy. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity, the azinobis ethylbenzothiazoline 6-sulphonic acid (ABTS) Ferric reducing antioxidant power (FRAP) assay and the antibacterial activities of both control and irradiated samples extracted in methanol and ethanol were evaluated. The results showed that the irr Tunisian Inula Viscosa extracts had strong antioxidant ability. The scavenger DPPH, ABTS and FRAP values of all extracts decreased significantly after irradiation. In addition, all extracts were effective against all the gram positive and gram negative pathogens. Gamma irradiation preserved the antibacterial activities of extracts and enhanced significantly (p≺0.05) the activity of extracts against E.coli. These data indicated the potential use of gamma-irradiation as a safe technique for preservation of Inula Viscosa as a medicinal plant with effective antioxidant and antibacterial activities

  6. Antibacterial effect of surface pretreatment techniques against ...

    African Journals Online (AJOL)

    (CFU/ml), respectively, among the groups evaluated (P < 0.05). Er:YAG laser irradiation and its combinations with other antibacterial surface pretreatment applications also inhibited the bacterial growth with, respectively, 1444, 406, and 294 CFU/ml bacterial recovery being more efficient than KTP laser irradiation and ozone ...

  7. Antibacterial and synergistic effects of Nardostachytis rhizoma ...

    African Journals Online (AJOL)

    Methicillin-resistant Staphylococcus aureus (MRSA) is a serious clinical problem worldwide. Few new drugs are available against MRSA, because it has the ability to acquire resistance to most antibiotics which consequently increases the cost of medication. In the present study, the antibacterial activity of Nardostachytis ...

  8. ANTIBACTERIAL AND TOXICOLOGICAL EFFECTS OF LEAF ...

    African Journals Online (AJOL)

    2017-01-27

    Jan 27, 2017 ... antibiotic used as the control (Idu et al.,2012). Only extracts that showed high antibacterial activity and served as potential source of drug development were used for the oral acute toxicity. Thin–Layer Chromatography. Thin layer chromatography was performed on a sheet of glass coated with a thin layer of ...

  9. Effect of the existing form of Cu element on the mechanical properties, bio-corrosion and antibacterial properties of Ti-Cu alloys for biomedical application.

    Science.gov (United States)

    Zhang, Erlin; Wang, Xiaoyan; Chen, Mian; Hou, Bing

    2016-12-01

    Ti-Cu alloys have exhibited strong antibacterial ability, but Ti-Cu alloys prepared by different processes showed different antibacterial ability. In order to reveal the controlling mechanism, Ti-Cu alloys with different existing forms of Cu element were prepared in this paper. The effects of the Cu existing form on the microstructure, mechanical, corrosion and antibacterial properties of Ti-Cu alloys have been systematically investigated. Results have shown that the as-cast Ti-Cu alloys showed a higher hardness and mechanical strength as well as a higher antibacterial rate (51-64%) but a relatively lower corrosion resistance than pure titanium. Treatment at 900°C/2h (T4) significantly increased the hardness and the strength, improved the corrosion resistance but had little effect on the antibacterial property. Treatment at 900°C/2h+400°C/12h (T6) increased further the hardness and the mechanical strength, improved the corrosion resistance and but also enhanced the antibacterial rate (>90%) significantly. It was demonstrated that the Cu element in solid solution state showed high strengthening ability but low antibacterial property while Cu element in Ti2Cu phase exhibited strong strengthening ability and strong antibacterial property. Ti2Cu phase played a key role in the antibacterial mechanism. The antibacterial ability of Ti-Cu alloy was strongly proportional to the Cu content and the surface area of Ti2Cu phase. High Cu content and fine Ti2Cu phase would contribute to a high strength and a strong antibacterial ability. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. The effect of antibacterial agents on plasma vitamin C levels.

    Science.gov (United States)

    Alabi, Z O; Thomas, K D; Ogunbona, O; Elegbe, I A

    1994-06-01

    Previous report on the estimation of plasma ascorbic acid levels in patients with chronic osteomyelitis indicated that the plasma ascorbic acid level is reduced in patients on antibiotics. The plasma study of the effects of anti-bacterial agents on plasma ascorbic acid in vitro, was carried out to substantiate the hypothesis than these agents lower plasma ascorbic acid levels. Increasing amounts of each of seven anti-bacterial agents: ampicillin, chloramphenicol, cefotaxime, gentamycin, benzyl and procaine penicillin combination (seclopen), co-trimoxazole, and streptomycin significantly (P < 0.01, r = -0.9587) reduced plasma vitamin C levels in vitro. There was moderate but insignificant reduction in plasma vitamin C levels with clindamycin (r = -0.799). The reduction of the plasma vitamin C levels observed in the presence of the eighth anti-bacterial agent, clindamycin, lacked significance (r = -0.799). The cause of this reduction of plasma vitamin C levels by anti-bacterial agents in vitro is not yet understood. A supplement of vitamin C may be required in patients on anti-bacterial agents.

  11. MINERAL PROFILE EVOLUTION OF SOME MEDICINAL PLANTS WITH ANTIBACTERIAL EFFECTS

    Directory of Open Access Journals (Sweden)

    Claudia Pasca

    2016-11-01

    Full Text Available Individual minerals and antibacterial activity were investigated in 5 medicinal plants (pot marigold - Calendula officinalis, burdock - Arctium lappa, celandine - Chelidonium majus, basil- Ocimum basilicum, thyme - Thymus vulgaris using Atomic Absorption Spectroscopy (AAS technique and antibiogram  method. The antibacterial susceptibility has been evaluated over 12 strains isolated from milk microflora, belonging to Staphylococcus, Vibrio, Serratia and Bacillus genera. The obtained results show the best antibacterial effect with  Arctium lappa ethanol extracts, having inhibition areas of 6.3 to 17.5 mm, with an average of 9.0 mm and the highest determined mineral being Calcium. The results obtained open the prospect of using these medicinal plants as an alternative to be used for the control and cure of some mineral deficiencies or for preventing various diseases of the animals.

  12. Effects of surface contamination and cleaning with hypochlorite wipes on the antibacterial activity of copper-alloyed antibacterial stainless steel.

    Science.gov (United States)

    Kawakami, Hiroshi; Hayashi, Takatsuna; Nishikubo, Hideyuki; Morikawa, Akifumi; Suzuki, Satoshi; Sato, Yoshihiro; Kikuchi, Yasushi

    2014-01-01

    Effects of surface contamination and cleaning with hypochlorite wipes on the antibacterial activity of copper-alloyed stainless steel were studied. The antibacterial activity of copper alloyed stainless steel decreased with the increase in the amount of surface contaminant, and the bacterial counts from specimens contaminated with a contaminant, e.g. 1.6 × 10(-2) μg/mm(2) of bovine serum albumin, were not significantly different from those from ordinary stainless steel specimens. The once contaminated surface could regain its antibacterial activity when it was sufficiently wiped clean with sterile wipes loaded with sodium hypochlorite solution.

  13. Hemostatic, anti-inflammatory and antibacterial effects of ...

    African Journals Online (AJOL)

    Purpose: To study the hemostatic, anti-inflammatory and antibacterial effects of Sanqixiantao dressing. Methods: Sanqixiantao dressing was prepared by mixting with sanqixiiantao extract (8 %) with membrane-forming matrix (5:4:9:2 volume ratio of polyvinyl alcohol: Na CMC: gelatin: glycerol). Rats with local surface ...

  14. Molecular composition and antibacterial effect of essential oil of ...

    African Journals Online (AJOL)

    pc

    2013-05-15

    May 15, 2013 ... The aim of this work was to test the antibacterial effects of essential oil extracted from Nigella sativa strains on gram positive and negative (Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia) bacteria. This study was based on extraction by steam distillation and analysis of organoleptic and.

  15. Synergistic antibacterial effect of stem bark extracts of Faidherbia ...

    African Journals Online (AJOL)

    The study was aimed at screening the stem bark extracts of Faidherbia albida and Psidium guajava for synergistic antibacterial effect against methicillin resistant Staphylococcus aureus (MRSA). The powdered plant materials were extracted with methanol using cold maceration technique and the extracts were screened for ...

  16. Anti-Inflammatory, Antioxidant, and Selective Antibacterial Effects of ...

    African Journals Online (AJOL)

    Euadenia eminens Hook f. (Capparaceae) has traditional uses in the management of conjunctivitis, iritis, ophthalmia, tuberculosis, otalgia and rectal prolapse. The fruit pulp is also eaten as an aphrodisiac. In this paper, we report on the antiinflammatory, antioxidant and antibacterial effects of its roots. A 70 % ethanol extract ...

  17. Antibacterial effects of cyanogenic glucoside isolated from the stem ...

    African Journals Online (AJOL)

    The chemical contents and in vitro antibacterial effects of the n-butanol column fractions, stem bark methanol extracts of Bauhinia rufescens Lam. were evaluated in Gram-positive and Gram-negative bacteria using disc diffusion technique. The n-butanol soluble portion from the stem bark methanol extract was successively ...

  18. Phytochemical and in-vitro antibacterial effects of the partitioned ...

    African Journals Online (AJOL)

    The study into the chemical contents and in-vitro antibacterial effects of the portioned portions of the methanol stem bark extracts of Bauhinia rufescens Lam were evaluated in some Gram positive and Gram negative bacteria using the hole-in-plate disc diffusion technique. The methanol stem bark extract was successively ...

  19. Experimental study on the optimization of extraction process of garlic oil and its antibacterial effects.

    Science.gov (United States)

    Guo, Yajie

    2014-01-01

    Garlic oil which is the main active constituent of garlic has a wide range of pharmacological activities, and a broad antibacterial spectrum. It also has a strong anti-cancer activity, and can significantly inhibit a variety of tumors such as liver cancer, gastric cancer and colon cancer. The objective is to study the extraction process of garlic oil and its antibacterial effects. CO2 Supercritical extraction was used to investigate the optimal processing conditions for garlic oil extraction; filter paper test and suspension dilution test were applied to determine the bacteriostatic action of garlic oil. In the CO2 supercritical extraction experiment, factors influencing the yield of garlic oil were: extraction pressure > extraction temperature > extraction time in descending order. Range analysis showed that the optimal experimental conditions for CO2 supercritical extraction of garlic oil were extraction pressure of 15 Mpa, temperature of 40 °C, and duration of 1 h. Different concentrations of garlic oil could all inhibit the growth of Staphylococcus aureus, Escherichia coli and Bacillus subtilis, suggesting that garlic oil has an antibacterial effect. The optimal experimental conditions for CO2 supercritical extraction of garlic oil were: extraction pressure of 15 Mpa, temperature of 40 °C, and duration of 1 h; garlic oil has an antibacterial effect.

  20. 'Artilysation' of endolysin λSa2lys strongly improves its enzymatic and antibacterial activity against streptococci.

    Science.gov (United States)

    Rodríguez-Rubio, Lorena; Chang, Wai-Ling; Gutiérrez, Diana; Lavigne, Rob; Martínez, Beatriz; Rodríguez, Ana; Govers, Sander K; Aertsen, Abram; Hirl, Christine; Biebl, Manfred; Briers, Yves; García, Pilar

    2016-10-24

    Endolysins constitute a promising class of antibacterials against Gram-positive bacteria. Recently, endolysins have been engineered with selected peptides to obtain a new generation of lytic proteins, Artilysins, with specific activity against Gram-negative bacteria. Here, we demonstrate that artilysation can also be used to enhance the antibacterial activity of endolysins against Gram-positive bacteria and to reduce the dependence on external conditions. Art-240, a chimeric protein of the anti-streptococcal endolysin λSa2lys and the polycationic peptide PCNP, shows a similar species specificity as the parental endolysin, but the bactericidal activity against streptococci increases and is less affected by elevated NaCl concentrations and pH variations. Time-kill experiments and time-lapse microscopy demonstrate that the killing rate of Art-240 is approximately two-fold higher compared to wildtype endolysin λSa2lys, with a reduction in viable bacteria of 3 log units after 10 min. In addition, lower doses of Art-240 are required to achieve the same bactericidal effect.

  1. Selective antibacterial effects of mixed ZnMgO nanoparticles

    Science.gov (United States)

    Vidic, Jasmina; Stankic, Slavica; Haque, Francia; Ciric, Danica; Le Goffic, Ronan; Vidy, Aurore; Jupille, Jacques; Delmas, Bernard

    2013-05-01

    Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals—with the length of tetrapod legs about 100 nm and the diameter about 10 nm—were found to be the most effective antibacterial agents since both Gram-positive ( B. subtilis) and Gram-negative ( E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size 50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed that B. subtilis cells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.

  2. Selective antibacterial effects of mixed ZnMgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Vidic, Jasmina, E-mail: jasmina.vidic@jouy.inra.fr [VIM, Institut de la Recherche Agronomique (France); Stankic, Slavica, E-mail: slavica.stankic@insp.jussieu.fr; Haque, Francia [CNRS, Institut des Nanosciences de Paris, UMR 7588 (France); Ciric, Danica; Le Goffic, Ronan; Vidy, Aurore [VIM, Institut de la Recherche Agronomique (France); Jupille, Jacques [CNRS, Institut des Nanosciences de Paris, UMR 7588 (France); Delmas, Bernard [VIM, Institut de la Recherche Agronomique (France)

    2013-05-15

    Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals-with the length of tetrapod legs about 100 nm and the diameter about 10 nm-were found to be the most effective antibacterial agents since both Gram-positive (B. subtilis) and Gram-negative (E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size {approx}50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed that B. subtilis cells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.

  3. Enhanced Antibacterial effect of chitosan film using Montmorillonite/CuO nanocomposite.

    Science.gov (United States)

    Nouri, Afsaneh; Yaraki, Mohammad Tavakkoli; Ghorbanpour, Mohammad; Agarwal, Shilpi; Gupta, Vinod Kumar

    2018-04-01

    Montmorillonite -copper oxide (MMT-CuO) nanocomposites were prepared by a facile and eco-friendly method and introduced into chitosan (Cs) matrix to enhance its optical, mechanical and antibacterial properties. The synthesized composites were characterized using diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy. The antimicrobial activity of MMT-CuO nanocomposites showed more than 99% mortality against two Gram-negative bacterium (E.coli (PTCC 1270), P.aeruginosa (PTCC 1430)) and two Gram-positive bacterium (S.aureus (PTCC1112) B.cereus (PTCC- 1015)). The effect of weight fraction of MMT-CuO nanocomposites (1, 3 and 5% w/w) as antibacterial nanofiller on physical, optical, mechanical, microstructural, and antibacterial properties of chitosan films were evaluated. The obtained data showed that introducing small amount MMT-CuO to chitosan films could enhance the mechanical, antibacterial properties, and decreased both water solubility and UV transition with the lowest effect on the transparency of the films. The incorporation of 3% w/w MMT-CuO-90 nanocomposite into the films increased the tensile strong (TS), and elongation at break (E%) values 58.5% and 52.4%, respectively while reduced the water vapor permeability and oxygen permeability about 55% and 32%, respectively. CSG3MMT-CuO-90 films showed intense antibacterial activity against food borne pathogenic and more effective against S. aureus and B.cereus. than E.coli and P.aeruginosa. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Antibacterial Effect of Juglans Regia Bark against Oral Pathologic Bacteria

    Directory of Open Access Journals (Sweden)

    Faramarz Zakavi

    2013-01-01

    Full Text Available Background. In this study antimicrobial effect of ethanolic and aqueous extracts of Juglans regia bark in Iran was evaluated on four different oral bacteria, Streptococcus mutans, Streptococcus salivarius, Streptococcus sanguis, and Staphylococcus aureus. Methods. Aqueous and ethanol extracts of Juglans regia bark were prepared by using disk diffusion technique and Minimal Inhibitory Concentration (MIC methods. Tetracycline 30 μg and Erythromycin 15 μg were used as positive control and water as negative control in disk diffusion and MIC methods. Data were analyzed by ANOVA test. Results. The results showed that S. sanguis and S. mutans were the most sensitive and the most resistant bacteria against ethanolic and aqueous extracts, respectively. Ethanolic extract had significant antibacterial effect against all tested bacteria. Aqueous extract did not show antibacterial effect on S. mutans, in contrast to ethanolic extract. Aqueous extract had significantly antibacterial effect against Staphylococcus aureus, S. salivarius, and S. sanguis compared to control (P<0.0001, but it did not show effect on S. mutans when compared with Erythromycin. According to the obtained MIC values, ethanol extract of Juglans regia bark had the lowest rate. Conclusion. The results may provide the basis for using natural antimicrobial substance for oral hygiene prophylaxis purposes.

  5. Finding quantum effects in strong classical potentials

    Science.gov (United States)

    Hegelich, B. Manuel; Labun, Lance; Labun, Ou Z.

    2017-06-01

    The long-standing challenge to describing charged particle dynamics in strong classical electromagnetic fields is how to incorporate classical radiation, classical radiation reaction and quantized photon emission into a consistent unified framework. The current, semiclassical methods to describe the dynamics of quantum particles in strong classical fields also provide the theoretical framework for fundamental questions in gravity and hadron-hadron collisions, including Hawking radiation, cosmological particle production and thermalization of particles created in heavy-ion collisions. However, as we show, these methods break down for highly relativistic particles propagating in strong fields. They must therefore be improved and adapted for the description of laser-plasma experiments that typically involve the acceleration of electrons. Theory developed from quantum electrodynamics, together with dedicated experimental efforts, offer the best controllable context to establish a robust, experimentally validated foundation for the fundamental theory of quantum effects in strong classical potentials.

  6. Antibacterial Effectiveness Of Low Energy Diode Laser Irradiation

    OpenAIRE

    Howida M. Sharaf *, Adel M. Elkhodary**, Ali E. Saafan***, Mostafa I. Mostafa

    2012-01-01

    Background: With the poor oral hygiene exhibited by patients with Down syndrome, the potential for a robust flora arises causing Periodontitis. Along with periodontal disease, the patient population has other medical conditions that limit treatment. This study was conducted to evaluate the antibacterial effectiveness of an 870-nm diode laser on periodontitis in patients with Down syndrome. Subjects & methods :Thirty five patients with Down syndrome suffering from p...

  7. Enhanced antibacterial effects of clove essential oil by nanoemulsion.

    Science.gov (United States)

    Anwer, Md Khalid; Jamil, Shahid; Ibnouf, Elmutasim Osman; Shakeel, Faiyaz

    2014-01-01

    The aim of present study was to develop and evaluate nanoemulsion formulations of clove essential oil (CEO) for its antibacterial effects in comparison with pure CEO and standard amikacin antibiotic (positive control). Different nanoemulsions of CEO were developed by aqueous phase titration method via construction of pseudo-ternary phase diagrams and investigated for thermodynamic stability and self-nanoemulsification tests. Selected formulations (F1-F5) were characterized for droplet size distribution, viscosity, zeta potential, transmittance and surface morphology. Based on lowest droplet size (29.1 nm), lowest PI (0.026), lowest viscosity (34.6 cp), optimal zeta potential (-31.4 mV), highest transmittance (99.4 %) and lowest concentration of Triacetin (8 % w/w), CEO nanoemulsion F1 (containing 1 % w/w of CEO, 8 % w/w of Triacetin, 15 % w/w of Tween-80, 15 % w/w of Labrasol and 61 % w/w of water) was subjected to antibacterial studies in comparison with pure oil and standard amikacin. The antibacterial effects of F1 were found to be superior over pure oil against all bacterial strains investigated. However, the antibacterial effects of F1 were highly comparable with standard amikacin against all bacterial strains. The minimum inhibitory concentrations (MICs) of F1 were observed in the range of 0.075-0.300 % w/w as compared to pure oil (MICs 0.130-0.500 % w/w) and standard amikacin (MICs 2-16 μg/ml). These results indicated the potential of nanoemulsions for enhancing the therapeutic efficacy of natural bioactive ingredients such as CEO.

  8. Effect of pressurization on antibacterial properties of Lactobacillus strains

    Science.gov (United States)

    Jankowska, Agnieszka; Grześkiewicz, Aleksandra; Wiśniewska, Krystyna; Reps, Arnold

    2010-03-01

    The objective of the study was to determine the effect of high pressures on antibacterial properties of selected strains of the Lactobacillus species. Cultures of 22 strains were subjected to high-pressure treatment at 30, 60, 90, and 300 MPa/1 min/18 °C. The susceptibility of the bacteria pressurized at 30-90 MPa was diversified and depended on the strain and not on its species affiliation. When compared with pressures of 30-90 MPa, the pressure treatment at 300 MPa caused the inhibition of the acidifying activity of the strains analyzed. In turn, the pressures applied had no impact on the quantity of hydrogen peroxide synthesized. An increase in pressure was accompanied by a diminishing antibacterial activity of the investigated Lactobacillus strains.

  9. The Effect of Culture Medium on Metabolic and Antibacterial Activities of Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    f Mirdavoudi

    2012-05-01

    Full Text Available

    <strong>Background and Objectives: strong>Probiotic bacteria is added directly to food components and it has beneficial effect on function and the health of organisms. The bifidogenic factors enter the colon where they contribute to an increase lactic acid bacteria population including Lactobacilli and Bifidobacteria and they inhibit enteric pathogenic bacterial growth. The aim of this study is to investigate the effect of culture medium on metabolic and antibacterial of probiotic bacteria.<strong>strong>

     

    >Methods: strong>In this study, the probiotics bacterial and intestine pathogenic are to be used. Lactobacilli and Bifidobacterium were identified by plating samples on MRS medium, Gram Staining and standard biochemical methods. The effect of antagonistic probiotics was investigated in the presence of growth factor in the method well diffusion Ager on the Shigella flexneri (PTCC 1234, Escherichia coli (PTCC 1552, Salmonella typhi ( PTCC 1609 and the culture medium pH was measured.<strong>strong>

     

    >Results: strong>The probiotics bacterial growth in MRS and lactose1%, sorbitol, raffinose, riboflavin were shown the effect antibacterial. The results of the study show the most antagonistic activity in commercial strain Lactobacillus acidophilus on Shigella flexneri and lower activity was in Lactobacillus casei (PTCC 1608, and Salmonella typhimurium (PTCC 1609, and also in Bbifidobacterium bifidum, it showed the most decrease pH value.<strong>strong>

     

    >Conclusion: strong>According to the result of the study, adding growth factors to MRS medium base and lactose 1%, probiotic growth was increased and which also increased antagonistic activity.<strong>>

     

  10. Effect of an Antibacterial Monomer on the Antibacterial Activity of a Pit-and-Fissure Sealant.

    Directory of Open Access Journals (Sweden)

    Fan Yu

    Full Text Available Resin-based pit-and-fissure sealants are often used to form a barrier on the occlusal surface of molars to treat caries lesions; however, bacteria can remain in the pit and fissures without detection, increasing the risk of secondary caries. Sealants with antimicrobial properties or microbial repellent actions might be advantageous. The aim of this study was to assess the inhibitory effect of a 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB-incorporated sealant against Streptococcus mutans. MAE-DB (4% wt was incorporated into a commercially available sealant, Eco-S resin-based pit-and-fissure sealant (Vericom Co., Ltd., Korea; a sealant without MAE-DB served as a negative control, and Clinpro™ Sealant (3M™ ESPE™, a fluoride-releasing resin, was used as a commercial control. The effects of the cured sealants and their eluents on the growth of S. mutans were determined according to colony-forming unit counts and metabolic tests. The effects of the cured sealants on the adherence and membrane integrity of S. mutans were investigated using confocal laser-scanning microscopy (CLSM in conjunction with fluorescent indicators. Compared with the negative control and commercial control, the cured MAE-DB-incorporated pit-and-fissure sealant exhibited a significant inhibitory effect on the growth of S. mutans (P < 0.05, whereas the eluents did not show any detectable antibacterial activity. The commercial control also showed no detectable bactericidal activity. Moreover, the aged experimental material retained its property of contact inhibition of biofilm formation. The fluorescence analysis of CLSM images demonstrated that the cured MAE-DB-incorporated sealant could hamper the adherence of S. mutans and exert a detrimental effect on bacterial membrane integrity. The incorporation of MAE-DB can render a pit-and-fissure sealant with contact antibacterial activity after polymerization via influencing the growth, adherence, and membrane

  11. Wormhole effect in a strong topological insulator

    Science.gov (United States)

    Rosenberg, G.; Guo, H.-M.; Franz, M.

    2010-07-01

    An infinitely thin solenoid carrying magnetic flux Φ (a “Dirac string”) inserted into an ordinary band insulator has no significant effect on the spectrum of electrons. In a strong topological insulator, remarkably, such a solenoid carries protected gapless one-dimensional fermionic modes when Φ=hc/2e . These modes are spin-filtered and represent a distinct bulk manifestation of the topologically nontrivial insulator. We establish this “wormhole” effect by both general qualitative considerations and by numerical calculations within a minimal lattice model. We also discuss the possibility of experimental observation of a closely related effect in artificially engineered nanostructures.

  12. Antibacterial effect of phosphates and polyphosphates with different chain length.

    Science.gov (United States)

    Lorencová, Eva; Vltavská, Pavlína; Budinský, Pavel; Koutný, Marek

    2012-01-01

    The aim of this study was to monitor the antibacterial effect of seven phosphate salts on selected strains of Gram-negative and Gram-positive bacteria, which could be considered responsible for food-borne diseases (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Staphylococcus aureus, Citrobacter freundii, Escherichia coli, Proteus mirabilis, Salmonella enterica ser. Enteritidis and Pseudomonas aeruginosa). For these purposes, phosphates differing in chain length were used. The tested concentrations were in the range of 0.1-2.0% (wt v(-1)) applied at the model conditions. In the majority of cases the visible inhibitory effect on the growth of observed microorganisms could be seen. Due to the chemical structure of salts and their dissociation both the pH values of cultivation broth and similarly the growth characteristics of bacterial strains were affected. The inhibition of above mentioned bacteria was apparently supported by this dissociation. Phosphates obviously made the development of most Gram-positive bacteria impossible. Especially Micrococcus luteus was extremely sensitive to the presence of these substances. On the other hand, Gram-negative bacteria seemed to be resistant to the phosphate incidence. The exemption clause from the tested salts was represented by a high alkaline trisodium phosphate. It should be pointed out that generally the most significant antibacterial effects were shown by polyphosphates HEXA68 and HEXA70, trisodium phosphate undecahydrate, tetrasodium pyrophosphate and finally trisodium phosphate. By comparing the inhibitory effects of various phosphate salts can be concluded that the antibacterial activity was not determined only by the condensation degree but there was also proved the dependence on pH values.

  13. Deodorant effects of a sage extract stick: Antibacterial activity and sensory evaluation of axillary deodorancy

    OpenAIRE

    Shahtalebi, Mohammad Ali; Ghanadian, Mustafa; Farzan, Ali; Shiri, Niloufar; Shokri, Dariush; Fatemi, Syed Ali

    2013-01-01

    Background: Deodorant products prevent the growth and activity of the degrading apocrine gland bacteria living in the armpit. Common antibacterial agents in the market like triclosan and aluminum salts, in spite of their suitable antibacterial effects, increase the risk of Alzheimer′s disease, breast and prostate cancers or induce contact dermatitis. Therefore, plant extracts possessing antibacterial effects are of interest. The aim of the present study was to verify the in vitro antimicrobia...

  14. Antibacterial Effects of Various Root Filling Materials

    OpenAIRE

    Pezelj-Ribarić, Sonja; Brekalo, Ivana; Abram, Maja; Miletić, Ivana; Anić, Ivica; Ferreri, Silvio; Foško-Glavaš, Laura

    2000-01-01

    The aim of this study was to evaluate the antimicrobial properties of three endodontic sealers (AH 26, Ketac-Endo and Apexit) using Direct Contact Test (DCT) and Agar Diffusion Test (ADT). DCT is based on measuring the effect of close contact between test bacteria and tested material, while ADT measures the areas of bacterial growth inhibition and consequently the incidence of microbial resistence of bacteria. The results of DCT showed that all tested materials, apart from Apexit, have ant...

  15. Effects of chitin nano-whiskers on the antibacterial and physicochemical properties of maize starch films.

    Science.gov (United States)

    Qin, Yang; Zhang, Shuangling; Yu, Jing; Yang, Jie; Xiong, Liu; Sun, Qingjie

    2016-08-20

    We investigated the effects of chitin nano-whiskers (CNWs) on the antibacterial and physiochemical properties of maize starch-based films. The microstructures, crystalline structures, and thermal, mechanical and barrier properties of the nanocomposite films were characterized by using transmission electron microscopy, X-ray diffraction analysis, thermogravimetric, differential scanning calorimeter, and texture profile analysis. The tensile strength of the maize starch films increased from 1.64MPa to 3.69MPa (Pstarch films. Furthermore, the nanocomposite films exhibited strong antimicrobial activity against Gram-positive Listeria monocytogenes but not against Gram-negative Escherichia coli. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Antibacterial activity of silver-killed bacteria: the "zombies" effect

    Science.gov (United States)

    Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David

    2015-04-01

    We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

  17. Effect of temperature on antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa.

    Science.gov (United States)

    Taki, Y; Seki, K; Ikigai, H; Nishihara, S; Ueno, H; Murota, K; Masuda, S

    1988-01-01

    The effect of temperature on the antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa was investigated in vitro. At 10 C at which S. aureus organisms do not grow and might be metabolically inactive, the antibacterial activity of lidocaine to S. aureus was not observed in a concentration of 1%, which was quite antibacterial to S. aureus at 37 C. On the other hand, at 40 C a conspicuously increased antibacterial activity to S. aureus of lidocaine was observed in a concentration of 0.25% which was not antibacterial to S. aureus organisms at 37 C. Similar results were obtained when P. aeruginosa organisms were examined in place of S. aureus, although P. aeruginosa was found to be less susceptible to lidocaine than S. aureus. The clinical significance of the thermal effect on the antibacterial activity of lidocaine was discussed in brief.

  18. Effect of antibacterial dental adhesive on multispecies biofilms formation.

    Science.gov (United States)

    Zhang, K; Wang, S; Zhou, X; Xu, H H K; Weir, M D; Ge, Y; Li, M; Wang, S; Li, Y; Xu, X; Zheng, L; Cheng, L

    2015-04-01

    Antibacterial adhesives have favorable prospects to inhibit biofilms and secondary caries. The objectives of this study were to investigate the antibacterial effect of dental adhesives containing dimethylaminododecyl methacrylate (DMADDM) on different bacteria in controlled multispecies biofilms and its regulating effect on development of biofilm for the first time. Antibacterial material was synthesized, and Streptococcus mutans, Streptococcus gordonii, and Streptococcus sanguinis were chosen to form multispecies biofilms. Lactic acid assay and pH measurement were conducted to study the acid production of controlled multispecies biofilms. Anthrone method and exopolysaccharide (EPS):bacteria volume ratio measured by confocal laser scanning microscopy were performed to determine the EPS production of biofilms. The colony-forming unit counts, scanning electron microscope imaging, and dead:live volume ratio decided by confocal laser scanning microscopy were used to study the biomass change of controlled multispecies biofilms. The TaqMan real-time polymerase chain reaction and fluorescent in situ hybridization imaging were used to study the proportion change in multispecies biofilms of different groups. The results showed that DMADDM-containing adhesive groups slowed the pH drop and decreased the lactic acid production noticeably, especially lactic acid production in the 5% DMADDM group, which decreased 10- to 30-fold compared with control group (P biofilms compared with control group (P biofilm had a more healthy development tendency after the regulation of DMADDM. In conclusion, the adhesives containing DMADDM had remarkable antimicrobial properties to serve as "bioactive" adhesive materials and revealed its potential value for antibiofilm and anticaries clinical applications. © International & American Associations for Dental Research 2015.

  19. A synergistic effect of artocarpanone from Artocarpus heterophyllus L. (Moraceae) on the antibacterial activity of selected antibiotics and cell membrane permeability.

    Science.gov (United States)

    Septama, Abdi Wira; Xiao, Jianbo; Panichayupakaranant, Pharkphoom

    2017-01-01

    Artocarpanone isolated from Artocarpus heterophyllus L. (Moraceae) exhibits antibacterial activity. The present study investigated synergistic activity between artocarpanone and tetracycline, ampicillin, and norfloxacin, respectively, against methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa , and Escherichia coli . A broth microdilution method was used for evaluating antibacterial susceptibility. Synergistic effects were identified using a checkerboard method, and a bacterial cell membrane disruption was investigated by assay of released 260 nm absorbing materials following bacteriolysis. Artocarpanone exhibited weak antibacterial activity against MRSA and P. aeruginosa with minimum inhibitory concentrations values of 125 and 500 μg/mL, respectively. However, the compound showed strong antibacterial activity against E. coli (7.8 μg/mL). The interaction between artocarpanone and all tested antibiotics revealed indifference and additive effects against P. aeruginosa and E. coli (fractional inhibitory concentration index [FICI] values of 0.75-1.25). The combination of artocarpanone (31.2 μg/mL) and norfloxacin (3.9 μg/mL) resulted in synergistic antibacterial activity against MRSA, with an FICI of 0.28, while the interaction between artocarpanone and tetracycline, and ampicillin showed an additive effect, with an FICI value of 0.5. A time-kill assay also indicated that artocarpanone had a synergistic effect on the antibacterial activity of norfloxacin. In addition, the combination of artocarpanone and norfloxacin altered the membrane permeability of MRSA. These findings suggest that artocarpanone may be used to enhance the antibacterial activity of norfloxacin against MRSA.

  20. Effect of salivary pellicle on antibacterial activity of novel antibacterial dental adhesives using a dental plaque microcosm biofilm model

    Science.gov (United States)

    Li, Fang; Weir, Michael D.; Fouad, Ashraf F.; Xu, Hockin H.K.

    2014-01-01

    Objectives Antibacterial primer and adhesive are promising to inhibit biofilms and caries. Since restorations in vivo are exposed to saliva, one concern is the attenuation of antibacterial activity due to salivary pellicles. The objective of this study was to investigate the effects of salivary pellicles on bonding agents containing a new monomer dimethylaminododecyl methacrylate (DMADDM) or nanoparticles of silver (NAg) against biofilms for the first time. Methods DMADDM and NAg were synthesized and incorporated into Scotchbond Multi-Purpose adhesive and primer. Specimens were either coated or not coated with salivary pellicles. A microcosm biofilm model was used with mixed saliva from ten donors. Two types of culture medium were used: an artificial saliva medium (McBain), and Brain Heart Infusion (BHI) medium without salivary proteins. Metabolic activity, colony-forming units (CFU), and lactic acid production of plaque microcosm biofilms were measured (n = 6). Results Bonding agents containing DMADDM and NAg greatly inhibited biofilm activities, even with salivary pellicles. When using BHI, the pre-coating of salivary pellicles on resin surfaces significantly decreased the antibacterial effect (p control, the DMADDM-containing bonding agent reduced biofilm CFU by about two orders of magnitude. Significance Novel DMADDM- and NAg-containing bonding agents substantially reduced biofilm growth even with salivary pellicle coating on surfaces, indicating a promising usage in saliva-rich environment. DMADDM and NAg may be useful in a wide range of primers, adhesives and other restoratives to achieve antibacterial and anti-caries capabilities. PMID:24332270

  1. Antibacterial effect of taurolidine (2%) on established dental plaque biofilm.

    Science.gov (United States)

    Arweiler, Nicole Birgit; Auschill, Thorsten Mathias; Sculean, Anton

    2012-04-01

    Preliminary data have suggested that taurolidine may bear promising disinfectant properties for the therapy of bacterial infections. However, at present, the potential antibacterial effect of taurolidine on the supragingival plaque biofilm is unknown. To evaluate the antibacterial effect of taurolidine on the supragingival plaque biofilm using the vital fluorescence technique and to compare it with the effect of NaCl and chlorhexidine (CHX), 18 subjects had to refrain from all mechanical and chemical hygiene measures for 24 h. A voluminous supragingival plaque sample was taken from the buccal surfaces of the lower molars and wiped on an objective slide. The sample was then divided into three equal parts and mounted with one of the three test or control preparations (a) NaCl, (b) taurolidine 2% and (c) CHX 0.2%. After a reaction time of 2 min, the test solutions were sucked of. Subsequently, the plaque biofilm was stained with fluorescence dye and vitality of the plaque flora was evaluated under the fluorescence microscope (VF%). Plaque samples treated with NaCl showed a mean VF of 82.42 ± 6.04%. Taurolidine affected mean VF with 47.57 ± 16.60% significantly (p control CHX showed the lowest mean VF values (34.41 ± 14.79%; p plaque biofilm which was, however, not as pronounced as that of CHX.

  2. Antibacterial effect of bismuth subsalicylate nanoparticles synthesized by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Castañeda, Mariela [Instituto Nacional de Investigaciones Nucleares (Mexico); Vega-Jiménez, Alejandro L., E-mail: argelia.almaguer@mac.com; Almaguer-Flores, Argelia [Universidad Nacional Autónoma de México, Facultad de Odontología, DEPeI, I (Mexico); Camps, Enrique; Pérez, Mario [Instituto Nacional de Investigaciones Nucleares (Mexico); Silva-Bermudez, Phaedra [Instituto Nacional de Rehabilitación, Unidad de Ingeniería de Tejidos, Terapia Celular y Medicina Regenerativa (Mexico); Berea, Edgardo [FarmaQuimia SA de CV. (Mexico); Rodil, Sandra E. [Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales (Mexico)

    2015-11-15

    The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens; E. coli, P. aeruginosa, S. aureus, and S. epidermidis were determined. BSS nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of E. coli and S. epidermidis was dependant on the NPs size and/or concentration, meanwhile P. aeruginosa and S. aureus were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area.

  3. Antibacterial effect of bismuth subsalicylate nanoparticles synthesized by laser ablation

    Science.gov (United States)

    Flores-Castañeda, Mariela; Vega-Jiménez, Alejandro L.; Almaguer-Flores, Argelia; Camps, Enrique; Pérez, Mario; Silva-Bermudez, Phaedra; Berea, Edgardo; Rodil, Sandra E.

    2015-11-01

    The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens; E. coli, P. aeruginosa, S. aureus, and S. epidermidis were determined. BSS nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of E. coli and S. epidermidis was dependant on the NPs size and/or concentration, meanwhile P. aeruginosa and S. aureus were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area.

  4. Strong curvature effects in Neumann wave problems

    DEFF Research Database (Denmark)

    Willatzen, Morten; Pors, A.; Gravesen, Jens

    2012-01-01

    Waveguide phenomena play a major role in basic sciences and engineering. The Helmholtz equation is the governing equation for the electric field in electromagnetic wave propagation and the acoustic pressure in the study of pressure dynamics. The Schro¨dinger equation simplifies to the Helmholtz...... equation for a quantum-mechanical particle confined by infinite barriers relevant in semiconductor physics. With this in mind and the interest to tailor waveguides towards a desired spectrum and modal pattern structure in classical structures and nanostructures, it becomes increasingly important...... to understand the influence of curvature effects in waveguides. In this work, we demonstrate analytically strong curvature effects for the eigenvalue spectrum of the Helmholtz equation with Neumann boundary conditions in cases where the waveguide cross section is a circular sector. It is found that the linear...

  5. Antibacterial effect assessment of ZnS: Ag nanoparticles

    Directory of Open Access Journals (Sweden)

    Najme Parvin

    2016-07-01

    Full Text Available Objective(s: A large ratio of surface to volume of nanoparticles in comparison with bulk ones, will increase the cell penetration and therefore their toxicity. Materials and Methods: Chemical precipitation method was used in order to synthesis of ZnS:Ag quantum dots. Their Physical properties and characteristics were assessed by X-ray diffraction, Ultra Violet-Visible Spectrophotometer, Transmission Electron Microscope and it was shown that the obtained ZnS:Ag quantum dots are cubic with high-quality. Antibacterial effects of ZnS:Ag nanoparticles against Pseudomonas aeroginosa, Staphylococcus aureus and Salmonella typhi were investigated. Disc bacteriological tests were used in order to assessment of the antibacterial effects of ZnS:Ag nanoparticles. Results: The size of inhibition zone was different according to the type of bacteria and the concentrations of ZnS:Ag QDs. The maximum diameter was happened for S. aureus. The results of  MICs obtained fromBroth Dilution for Pseudomonas aeruginosa , Staphylococcus aureus and Salmonella typhi, are 3.05 , 3.05 and 6.1 mg/ml whereas the amounts of obtained MBCs are 12.2 , 6.1 and 12.2 mg/ml respectively. Conclusion: In conclusion, by increasing the nanoparticle concentration in wells and discs, the growth inhibition and diameter of inhibition zone has also been increased.

  6. Strong curvature effects in Neumann wave problems

    International Nuclear Information System (INIS)

    Willatzen, M.; Pors, A.; Gravesen, J.

    2012-01-01

    Waveguide phenomena play a major role in basic sciences and engineering. The Helmholtz equation is the governing equation for the electric field in electromagnetic wave propagation and the acoustic pressure in the study of pressure dynamics. The Schrödinger equation simplifies to the Helmholtz equation for a quantum-mechanical particle confined by infinite barriers relevant in semiconductor physics. With this in mind and the interest to tailor waveguides towards a desired spectrum and modal pattern structure in classical structures and nanostructures, it becomes increasingly important to understand the influence of curvature effects in waveguides. In this work, we demonstrate analytically strong curvature effects for the eigenvalue spectrum of the Helmholtz equation with Neumann boundary conditions in cases where the waveguide cross section is a circular sector. It is found that the linear-in-curvature contribution originates from parity symmetry breaking of eigenstates in circular-sector tori and hence vanishes in a torus with a complete circular cross section. The same strong curvature effect is not present in waveguides subject to Dirichlet boundary conditions where curvature contributions contribute to second-order in the curvature only. We demonstrate this finding by considering wave propagation in a circular-sector torus corresponding to Neumann and Dirichlet boundary conditions, respectively. Results for relative eigenfrequency shifts and modes are determined and compared with three-dimensional finite element method results. Good agreement is found between the present analytical method using a combination of differential geometry with perturbation theory and finite element results for a large range of curvature ratios.

  7. The antibacterial effect assay of a few officinal plants

    Directory of Open Access Journals (Sweden)

    Daniela Moţ

    2010-05-01

    Full Text Available From very old times plants were used for man or animal health, with good results in slightly, functional injuries or in incipient stages of diseases. In chronic, when already appeared organic affection, officinal plants has an adjuvant part and can contributes to a partial reversibility of symptoms or lesions. This study was been performed using aqueous solutions or essential oils from Mentha spicata, Ocimum basilicum, Thymus vulgaris and Rosa sp. with bacterial cultures on usual or special culture mediums of Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica and Staphylococcus aureus. In view of antibacterial assay emphasizing were been used small pieces of absorbent paper immersed in solutions or essential oils above mentioned officinal plants. These pieces of papers then were been deposed in usual and special culture mediums containing the mentioned species of bacteria and then incubated 24 hours. The obtained result emphasized by the inhibition areas development recommend the antibacterial effect of essential oils of Rosa sp. (25.5 mm inhibition area, Mentha spicata (16.5 mm, Thymus vulgaris (7.3 mm and Ocimum basilicum (5.1 mm in therapeutic purpose, both in intern and extern way in infections caused by Bacillus cereus, Escherichia coli, Salmonella enterica and Staphylococcus aureus, in incipient stages.

  8. Antibacterial effects of protruding and recessed shark skin micropatterned surfaces of polyacrylate plate with a shallow groove.

    Science.gov (United States)

    Sakamoto, Akihiko; Terui, Yusuke; Horie, Chihiro; Fukui, Takashi; Masuzawa, Toshiyuki; Sugawara, Shintaro; Shigeta, Kaku; Shigeta, Tatsuo; Igarashi, Kazuei; Kashiwagi, Keiko

    2014-12-01

    Antibacterial effects in terms of biofilm formation and swarming motility were studied using polyacrylate plates having protruding or recessed shark skin micropatterned surfaces with a shallow groove (2 μm pattern width and spacing, 0.4 μm pattern height). It was found that biofilm formation and swarming motility of Pseudomonas aeruginosa were strongly inhibited by the shark skin pattern plates with a shallow (0.4 μm) pattern height. Biofilm formation of Staphylococcus aureus was also strongly inhibited. Live bacteria were located on the pattern rather than in the spacing. When the shape of pattern was a linear ridge instead of shark skin, the antibacterial effects were weaker than seen with the shark skin pattern. The results indicate that the pattern of shark skin is important for decreasing bacterial infection even with a shallow feature height. © 2014 Federation of European Microbiological Societies.

  9. Antibacterial and antifungal effect of high pH and paraffin wax ...

    African Journals Online (AJOL)

    The antibacterial and antifungal effects of high pH (9, 10) and paraffin wax were determined. Determination of antibacterial and antifungal activity of the combined treatments was achieved by aerobic mesophilic count of bacteria and fungi on the surface of the tomatoes, peppers and oranges using serial dilution and pour ...

  10. Antibacterial effects of cavity lining: a systematic review and network meta-analysis.

    Science.gov (United States)

    Schwendicke, Falk; Tu, Yu-Kang; Hsu, Le-Yin; Göstemeyer, Gerd

    2015-11-01

    Cavity liners are frequently used prior placing a restoration, with one main aim being to reduce the number of remaining bacteria. We systematically appraised studies comparing antibacterial effects of different liners against each other or no liner. reporting the number of sterile cavities before/after lining or sealing, or the reduction in bacterial numbers (colony-forming-units) in two or more treatment groups were included. Treatments were categorized as: no/placebo liner, calcium hydroxide, mineral trioxide aggregate, antibiotic/disinfectant, calcium phosphates, zinc oxide eugenol, black copper cement, and glass ionomer cement liners. Pairwise and network meta-analyses were performed. From 113 identified studies, 14 (500 treated lesions) were included. Risk of bias was high or unclear. Based on 11 studies, network meta-analysis found mineral trioxide lining to yield the greatest probability of achieving sterile cavities after a lining/sealing period (73%), followed by antibiotic/disinfectant (8%) and zinc oxide eugenol (7%). Only six studies assessed bacterial reduction after lining/sealing, and zinc oxide eugenol was found to have the highest probability of achieving a bacterial reduction. In both analyses, not providing any lining was found to have low antibacterial effects. Within the limitations of this review and the included studies, certain liners seem more suitable to achieve sterile cavities or reduce bacterial numbers than others. Given the paucity of data and the unclear impact of remaining bacteria on clinical outcomes, further recommendations for specific cavity treatments prior a restoration are not possible. There is insufficient evidence to generally recommend cavity lining or the use of any specific liner based on their antibacterial effects. Dentists might continue to use liners, but should be aware that such use is not strongly supported by clinical studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Effects of quaternary ammonium chain length on the antibacterial and remineralizing effects of a calcium phosphate nanocomposite

    Science.gov (United States)

    Zhang, Ke; Cheng, Lei; Weir, Michael D; Bai, Yu-Xing; Xu, Hockin HK

    2016-01-01

    Composites containing nanoparticles of amorphous calcium phosphate (NACP) remineralize tooth lesions and inhibit caries. A recent study synthesized quaternary ammonium methacrylates (QAMs) with chain lengths (CLs) of 3–18 and determined their effects on a bonding agent. This study aimed to incorporate these QAMs into NACP nanocomposites for the first time to simultaneously endow the material with antibacterial and remineralizing capabilities and to investigate the effects of the CL on the mechanical and biofilm properties. Five QAMs were synthesized: DMAPM (CL3), DMAHM (CL6), DMADDM (CL12), DMAHDM (CL16), and DMAODM (CL18). Each QAM was incorporated into a composite containing 20% NACP and 50% glass fillers. A dental plaque microcosm biofilm model was used to evaluate the antibacterial activity. The flexural strength and elastic modulus of nanocomposites with QAMs matched those of a commercial control composite (n = 6; P > 0.1). Increasing the CL from 3 to 16 greatly enhanced the antibacterial activity of the NACP nanocomposite (P control composite. The NACP nanocomposite with a CL of 16 produced 2-log decreases in the colony-forming units (CFU) of total microorganisms, total streptococci, and mutans streptococci. In conclusion, QAMs with CLs of 3–18 were synthesized and incorporated into an NACP nanocomposite for the first time to simultaneously endow the material with antibacterial and remineralization capabilities. Increasing the CL reduced the metabolic activity and acid production of biofilms and caused a 2-log decrease in CFU without compromising the mechanical properties. Nanocomposites exhibiting strong anti-biofilm activity, remineralization effects, and mechanical properties are promising materials for tooth restorations that inhibit caries. PMID:27025265

  12. Antibacterial effect of glycerol as preservative on donor skin

    International Nuclear Information System (INIS)

    Van Baare, J.; Ligtvoet, E.E.J.; Middelkoop, E.

    1999-01-01

    Glycerolised cadavetic allografts have been used widely since 1984 in the treatment of bum wounds. Rejections reaction to glycerolised skin were reported to be attenuated. Structural integrity of the skin was maintained and antiviral and antibacterial effects were noted. The Euro Skin Bank has gathered approximately 2000 data since 1987 concerning bacteriology cultures of glycerolised skin. These data are presented. Bacteriological data from skin donors were examined from 1987 till 1995 (1927 data). Donor skin sent to the laboratory and found to be positive for bacteria was quarantined and another container with skin samples was sent to the laboratory at a later time point. This was repeated until all cultures were negative. In 1987, 25 donors were processed without using antibiotics. These results were compared with donor skin treated with antibiotics. The average day for first culture was 19.7 ? 17.2. The average percentage of contaminated skin was 10.1? 3.7%. Antibiotics reduced contamination of glycerolised skin from 80% to 10.1%. Glycerol treatment also showed an antibacterial effect as all contaminated skin eventually became negative. Of the contaminated skin Staphylococcus epidermidis was found most frequently: in 70.7 ? 10.8% of the cases. Not all bacteria are equally sensitive to glycerol: Staphylococcus epidennidis contaminated skin became sterile after 48?24 days, whereas for Bacillus species it took 195? 1 37.9 days. We show that glycerol preservation of donor skin has important advantages over conservative methods such as cryopreservation. Initial contamination of the skin is no longer a reason to discard the material. Prolonged storage in glycerol will eliminate bacterial contamination. This allows an increase in yield of at least 10%

  13. Effect of salivary pellicle on antibacterial activity of novel antibacterial dental adhesives using a dental plaque microcosm biofilm model.

    Science.gov (United States)

    Li, Fang; Weir, Michael D; Fouad, Ashraf F; Xu, Hockin H K

    2014-02-01

    Antibacterial primer and adhesive are promising to inhibit biofilms and caries. Since restorations in vivo are exposed to saliva, one concern is the attenuation of antibacterial activity due to salivary pellicles. The objective of this study was to investigate the effects of salivary pellicles on bonding agents containing a new monomer dimethylaminododecyl methacrylate (DMADDM) or nanoparticles of silver (NAg) against biofilms for the first time. DMADDM and NAg were synthesized and incorporated into Scotchbond Multi-Purpose adhesive and primer. Specimens were either coated or not coated with salivary pellicles. A microcosm biofilm model was used with mixed saliva from ten donors. Two types of culture medium were used: an artificial saliva medium (McBain), and Brain Heart Infusion (BHI) medium without salivary proteins. Metabolic activity, colony-forming units (CFU), and lactic acid production of plaque microcosm biofilms were measured (n=6). Bonding agents containing DMADDM and NAg greatly inhibited biofilm activities, even with salivary pellicles. When using BHI, the pre-coating of salivary pellicles on resin surfaces significantly decreased the antibacterial effect (pbiofilms similar to salivary pellicles. Compared with the commercial control, the DMADDM-containing bonding agent reduced biofilm CFU by about two orders of magnitude. Novel DMADDM- and NAg-containing bonding agents substantially reduced biofilm growth even with salivary pellicle coating on surfaces, indicating a promising usage in saliva-rich environment. DMADDM and NAg may be useful in a wide range of primers, adhesives and other restoratives to achieve antibacterial and anti-caries capabilities. Published by Elsevier Ltd.

  14. Antibacterial effect of doxycycline-coated dental abutment surfaces

    International Nuclear Information System (INIS)

    Xing, Rui; Tiainen, Hanna; Shabestari, Maziar; Lyngstadaas, Ståle P; Haugen, Håvard J; Witsø, Ingun L; Lönn-Stensrud, Jessica; Jugowiec, Dawid

    2015-01-01

    Biofilm formation on dental abutment may lead to peri-implant mucositis and subsequent peri-implantitis. These cases are clinically treated with antibiotics such as doxycycline (Doxy). Here we used an electrochemical method of cathodic polarization to coat Doxy onto the outer surface of a dental abutment material. The Doxy-coated surface showed a burst release in phosphate-buffered saline during the first 24 h. However, a significant amount of Doxy remained on the surface for at least 2 weeks especially on a 5 mA–3 h sample with a higher Doxy amount, suggesting both an initial and a long-term bacteriostatic potential of the coated surface. Surface chemistry was analyzed by x-ray photoelectron spectroscopy and secondary ion mass spectrometry. Surface topography was evaluated by field emission scanning electron microscopy and blue-light profilometry. Longer polarization time from 1 h to 5 h and higher current density from 1 to 15 mA cm −2 resulted in a higher amount of Doxy on the surface. The surface was covered by a layer of Doxy less than 100 nm without significant changes in surface topography. The antibacterial property of the Doxy-coated surface was analyzed by biofilm and planktonic growth assays using Staphylococcus epidermidis. Doxy-coated samples reduced both biofilm accumulation and planktonic growth in broth culture, and also inhibited bacterial growth on agar plates. The antibacterial effect was stronger for samples of 5 mA–3 h coated with a higher amount of Doxy compared to that of 1 mA–1 h. Accordingly, an abutment surface coated with Doxy has potential for preventing bacterial colonization when exposed to the oral cavity. Doxy-coating could be a viable way to control peri-implant mucositis and prevent its progression into peri-implantitis. (paper)

  15. Phenolic constituents of Cassia seeds and antibacterial effect of some naphthalenes and anthraquinones on methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Hatano, T; Uebayashi, H; Ito, H; Shiota, S; Tsuchiya, T; Yoshida, T

    1999-08-01

    Thirteen phenolic glycosides including six new compounds were isolated from seeds of Cassia tora (Leguminosae). The structures of the new compounds, rubrofusarin triglucoside (7), nor-rubrofusarin gentiobioside (9), demethylflavasperone gentiobioside (10), torachrysone gentiobioside (11), torachrysone tetraglucoside (12) and torachrysone apioglucoside (13), were elucidated on the basis of spectroscopic and chemical evidence. The effects of the phenolic glycosides, their aglycones and several other compounds structurally related to them on Escherichia coli K12, Pseudomonas aeruginosa PAO1 and some strains of Staphylococcus aureus were then examined. Among them, torachrysone (15), toralactone (16), aloe-emodin (18), rhein (19) and emodin (20) showed noticeable antibacterial effects on four strains of methicillin-resistant Staphylococcus aureus with a minimum inhibitory concentration of 2-64 micrograms/ml. On the other hand, the phenolic compounds tested did not show strong antibacterial effects on E. coli and P. aeruginosa.

  16. A Synergistic effect of artocarpanone from Artocarpus heterophyllus Lam. (Moraceae on the antibacterial activity of some antibiotics and their effect on membrane permeability

    Directory of Open Access Journals (Sweden)

    Abdi Wira Septama

    2017-06-01

    Full Text Available Aim/backgrounds: Artocarpanone isolated from Artocarpus heterophyllus Lam. (Moraceae possesses antibacterial activity. The present study investigated any interaction between artocarpanone and some antibiotics including tetracycline, ampicillin and norfloxacin against Methicillin-resistant Staphylococcus aureus (MRSA, Pseudomonas aeruginosa and Escherichia coli, as well as determining any disruptive effect on bacterial membranes. Materials and methods: A broth microdilution method was used for the susceptibility assay. Any synergistic effect was determined using a checerboard method, and any membrane disruption effect was investigated using a bacteriolysis assay and a measurement of the released 260 nm absorbing materials. Results and discussion: Artocarpanone exhibited weak antibacterial activities against MRSA and P. aeruginosa with MIC values of 125 and 500 µg/mL, respectively. However, it showed the strong antibacterial activity against E. coli (7.8 µg/mL. The interaction between artcarpanone with all tested antibiotics against P. aeruginosa and E. coli only revealed indifference and additive effects (FICI values of 0.75-1.25. The interaction between artocarpanone (31.2 µg/mL and norfloxacin (3.9 µg/mL exhibited a synergistic antibacterial activity against MRSA, with a fractional inhibitory concentration index (FICI of 0.28, while the interaction between artocarpanone and tetracycline, and ampicillin showed an additive effect, with an FICI value of 0.5. A time kill assay also indicated that artocarpanone had a synergistic effect on the antibacterial activity of norfloxacin. In addition, a combination of artocarpanone and norfloxacin altered the membrane permeability of MRSA. Conclusion: These findings suggested that artocarpanone may be considered as an adjuvant to enhance the antibacterial activity of norfloxacin against MRSA. [J Complement Med Res 2017; 6(2.000: 186-191

  17. Antibacterial effect of Turkish black cumin ( Nigella sativa L. oils

    Directory of Open Access Journals (Sweden)

    Gecgel, Umit

    2005-12-01

    Full Text Available A series of five different oils from Turkish black cumin ( Nigella sativa used in foods mainly for their flavour, preservation and natural therapies were screened for their antibacterial effects at 0.5 %, 1.0 % and 2.0 % concentrations using the agar diffusion method against twenty four pathogenic, spoilage and lactic acid bacteria (LAB. All tested oils showed antibacterial activity against all the bacteria used in the assay. The oils at 2.0 % concentration were more effective than of the other concentrations. The most sensitive bacterium against all of the oil concentrations was Aeromonas hydrophila, while the most resistant was Yersinia enterocolitica. Generally, lactic acid bacteria had more resistance than pathogenic and spoilage bacteria against black cumin oils. Consequently, black cumin oil may be used as an antimicrobial agent in food products to prevent spoilage.Se ensayaron un total de cinco aceites diferentes de comino negro turco ( Nigella sativa L., que se utilizan habitualmente en alimentos para darles sabor, ayudar a la conservación o por sus efectos terapéuticos, para estudiar sus propiedades antimicrobianas a concentraciones de 0.5 %, 1.0 %, y 2 %. Para ello se utilizó el método de difusión en agar, frente a veinticuatro microorganismos patógenos, causantes de alteraciones o bacterias ácido lácticas (LAB. Todos los aceites ensayados mostraron actividad antimicrobiana contra todos los microorganismos ensayados, siendo las concentraciones del 2 % las concentraciones más eficaces. Aeromonas hydrophyla fue el microorganismo mas sensible a todas las concentraciones mientras que Yersinia enterocolitica fue la más resistente. Generalmente las bacterias acido lácticas tuvieron más resistencia que los gérmenes patógenos y las bacterias que causan alteraciones. En consecuencia, el aceite de comino negro turco se puede utilizar como agente antimicrobiano en productos alimenticios para evitar su alteración.

  18. Antibacterial effect of silver nanofilm modified stainless steel surface

    Science.gov (United States)

    Fang, F.; Kennedy, J.; Dhillon, M.; Flint, S.

    2015-03-01

    Bacteria can attach to stainless steel surfaces, resulting in the colonization of the surface known as biofilms. The release of bacteria from biofilms can cause contamination of food such as dairy products in manufacturing plants. This study aimed to modify stainless steel surfaces with silver nanofilms and to examine the antibacterial effectiveness of the modified surface. Ion implantation was applied to produce silver nanofilms on stainless steel surfaces. 35 keV Ag ions were implanted with various fluences of 1 × 1015 to 1 × 1017 ions•cm-2 at room temperature. Representative atomic force microscopy characterizations of the modified stainless steel are presented. Rutherford backscattering spectrometry spectra revealed the implanted atoms were located in the near-surface region. Both unmodified and modified stainless steel coupons were then exposed to two types of bacteria, Pseudomonas fluorescens and Streptococcus thermophilus, to determine the effect of the surface modification on bacterial attachment and biofilm development. The silver modified coupon surface fluoresced red over most of the surface area implying that most bacteria on coupon surface were dead. This study indicates that the silver nanofilm fabricated by the ion implantation method is a promising way of reducing the attachment of bacteria and delay biofilm formation.

  19. Strong crystal size effect on deformation twinning

    DEFF Research Database (Denmark)

    Yu, Qian; Shan, Zhi-Wei; Li, Ju

    2010-01-01

    find that the stress required for deformation twinning increases drastically with decreasing sample size of a titanium alloy single crystal7, 8, until the sample size is reduced to one micrometre, below which the deformation twinning is entirely replaced by less correlated, ordinary dislocation...... plasticity. Accompanying the transition in deformation mechanism, the maximum flow stress of the submicrometre-sized pillars was observed to saturate at a value close to titanium’s ideal strength9, 10. We develop a ‘stimulated slip’ model to explain the strong size dependence of deformation twinning....... The sample size in transition is relatively large and easily accessible in experiments, making our understanding of size dependence11, 12, 13, 14, 15, 16, 17 relevant for applications....

  20. Effect of povidone–iodine deposition on tribocorrosion and antibacterial properties of titanium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yu, E-mail: yanyu@ustb.edu.cn [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology Beijing, Beijing 100083 (China); Zhang, Yanbo [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology Beijing, Beijing 100083 (China); Wang, Qikui [Hebei General Hospital, Shijiazhuang (China); Du, Hongwu [School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing (China); Qiao, Lijie [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology Beijing, Beijing 100083 (China)

    2016-02-15

    Graphical abstract: OCP and COF result for treated Ti6Al4V sample after tribocorrosion test. - Highlights: • Tribocorrosion resistance and antibacterial effectiveness were improved by PVP–I deposition. • Nano- and mirco-pores were received. • Even after being damaged by tribology contacts, antibacterial properties were still effective. - Abstract: Infection remains one of the most common causes for the early-stage failure of orthopaedic implants. Many methods have been developed to reduce the growth of bacteria. However, devices such as orthopaedic implants involve relative motion in several parts, and suffer wear from tribocorrosion processes. The surface pattern and texture can be damaged and the anti-bacterial efficiency reduced. In this paper, a two-stage method is reported. Povidone–iodine (PVP–I) was deposited on the titanium alloy surfaces and inside the pores to provide a longer release time. The results show that even under tribological tests, the anti-bacterial performance still remains satisfactory.

  1. Antibacterial property of fabrics coated by magnesium-based brucites

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying; Sha, Lin; Zhao, Jiao; Li, Qian; Zhu, Yimin, E-mail: ntp@dlmu.edu.cn; Wang, Ninghui

    2017-04-01

    Highlights: • Magnesium-based antibacterial agents composited by brucites with different particle sizes were proposed for the first time. • The coating process for making antibacterial fabrics was easy to operate and apply in industrial application. • The materials used in the antibacterial fabrics were environmental-friendly and cost-effective. • Reduction percentage of as-prepared antibacterial fabrics against E. coli and S. aureus reached to 96.6%, 100% respectively. • The antibacterial fabrics attained excellent washing durability. - Abstract: A kind of environmental-friendly magnesium-based antibacterial agent was reported for the first time, which was composited by brucites with different particle sizes. The antibacterial fabrics were produced by coating the magnesium-based antibacterial agents on the 260T polyester pongee fabrics with waterborne polyurethane. The coating process was simple, low-cost, and harmless to human health and environment. Characteristics of the antibacterial agents and fabrics were studied by particulate size distribution analyzer (PSDA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results demonstrated that the coating layer was covered tightly on the fabrics and compositing of different particles by a certain proportion made full filling of the coating layer. Meanwhile, compositing did not change the structure of brucites. The antibacterial fabrics presented strong antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with the reduction percentage of 96.6% and 100%, respectively, and the antibacterial fabrics attained excellent washing durability.

  2. Antibacterial property of fabrics coated by magnesium-based brucites

    International Nuclear Information System (INIS)

    Wang, Ying; Sha, Lin; Zhao, Jiao; Li, Qian; Zhu, Yimin; Wang, Ninghui

    2017-01-01

    Highlights: • Magnesium-based antibacterial agents composited by brucites with different particle sizes were proposed for the first time. • The coating process for making antibacterial fabrics was easy to operate and apply in industrial application. • The materials used in the antibacterial fabrics were environmental-friendly and cost-effective. • Reduction percentage of as-prepared antibacterial fabrics against E. coli and S. aureus reached to 96.6%, 100% respectively. • The antibacterial fabrics attained excellent washing durability. - Abstract: A kind of environmental-friendly magnesium-based antibacterial agent was reported for the first time, which was composited by brucites with different particle sizes. The antibacterial fabrics were produced by coating the magnesium-based antibacterial agents on the 260T polyester pongee fabrics with waterborne polyurethane. The coating process was simple, low-cost, and harmless to human health and environment. Characteristics of the antibacterial agents and fabrics were studied by particulate size distribution analyzer (PSDA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results demonstrated that the coating layer was covered tightly on the fabrics and compositing of different particles by a certain proportion made full filling of the coating layer. Meanwhile, compositing did not change the structure of brucites. The antibacterial fabrics presented strong antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with the reduction percentage of 96.6% and 100%, respectively, and the antibacterial fabrics attained excellent washing durability.

  3. Strong coupling effects in hybrid plexitonic systems

    Science.gov (United States)

    Melnikau, Dzmitry; Esteban, Ruben; Govyadinov, Alexander A.; Savateeva, Diana; Simon, Thomas; Sánchez-Iglesias, Ana; Grzelczak, Marek; Schmidt, Mikolaj K.; Urban, Alexander S.; Liz-Marzán, Luis M.; Feldmann, Jochen; Aizpurua, Javier; Rakovich, Yury P.

    2017-08-01

    We investigated the interactions between localized plasmons in gold nanorods and excitons in J-aggregates and were able to track an anticrossing behavior of the hybridized modes both in the extinction and in the photoluminescence spectra of this hybrid system. We identified the nonlinear optical behavior of this system by transient absorption spectroscopy. Finally using magnetic circular dichroism spectroscopy we showed that nonmagnetic organic molecules exhibit magnetooptical response due to binding to a plasmonic nanoparticles. In our experiments we also studied the effect of detuning as well as the effect of off- and on resonance excitation on the hybrid states

  4. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    International Nuclear Information System (INIS)

    Yudovin-Farber, Ira; Beyth, Nurit; Weiss, Ervin I.; Domb, Abraham J.

    2010-01-01

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  5. Antibacterial effect of composite resins containing quaternary ammonium polyethyleneimine nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yudovin-Farber, Ira [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel); Beyth, Nurit; Weiss, Ervin I. [Hebrew University of Jerusalem, Department of Prosthodontics, Faculty of Dentistry (Israel); Domb, Abraham J., E-mail: avid@ekmd.huji.ac.i [Hebrew University of Jerusalem, Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Faculty of Medicine (Israel)

    2010-02-15

    Quaternary ammonium polyethyleneimine (QA-PEI)-based nanoparticles were synthesized by crosslinking with dibromopentane followed by N-alkylation with various alkyl halides and further N-methylation with methyl iodide. Insoluble pyridinium-type particles were prepared by suspension polymerization of 4-vinyl pyridine followed by N-alkylation with alkyl halides. Polyamine-based nanoparticles embedded in restorative composite resin at 1% w/w were tested for antibacterial activity against Streptococcus mutans using direct contact test. Activity analysis revealed that the alkyl chain length of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl-alkylated QA-PEI embedded in restorative composite resin at 1% w/w that totally inhibited S. mutans growth in 3-month-aged samples. This data indicates that restorative composite resin with antibacterial properties can be produced by the incorporation of QA-PEI nanoparticles.

  6. Effect of silver on antibacterial properties of stainless steel

    Science.gov (United States)

    Liao, Kuo-Hsing; Ou, Keng-Liang; Cheng, Hsin-Chung; Lin, Che-Tong; Peng, Pei-Wen

    2010-03-01

    The microstructural variation and antibacterial properties of the AISI 304 stainless steel containing silver (Ag) element have been investigated by means of optical microscopy (OM), grazing incidence X-ray diffractometry (GIXRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDS). Furthermore, the antibacterial testing was performed according to JIS Z2801:2000 specification. As the alloy contained Ag elements, the microstructure of the alloys was a mixture of (α + γ + Ag-rich compound)-phases. The amounts of α phase and Ag-rich compound increased as Ag contents increased. The Ag-rich compound has FCC structure with the lattice parameter a = 0.251 nm. No precipitates were found within the matrix and grain boundaries in the present alloys after SHT. Moreover, when the alloy is added to Ag element, antibacterial property was seen obvious against E. coli. It has an AR nearly of 100%.

  7. Antibacterial effect of ozone on cariogenic bacterial species.

    Science.gov (United States)

    Johansson, E; Claesson, R; van Dijken, J W V

    2009-06-01

    The aim was to evaluate the antibacterial effect of ozone on cariogenic bacterial species with and without the presence of saliva and a possible effect on the salivary proteins. Suspensions of Actinomyces naeslundii (ACTCC 12104(T)), Lactobacilli casei (N CTC 151) and Streptococcus mutans (NCTC 10449), in salt buffer or in saliva, were exposed to ozone gas delivered by the ozone generator Healozone 2130C. Aliquots of the suspensions were taken after 10, 30 and 60s ozone exposures and cultivated on agar plates. Initial number of bacteria per ml was 8.0 x 10(7) (SD 2.2 x 10(7)) (A. naeslundii), 1.0 x 10(8) (SD 3.1 x 10(6)) (L. casei) and 1.0 x 10(8) (SD 7.0 x 10(5)) (S. mutans), respectively. The proteins were separated by SDS electrophoresis and visualized by silver staining. In salt buffer 92%, 73% and 64% of the initial numbers of A. naeslundii, S. mutans and L. casei, respectively, were killed already after 10s ozone exposure, while approximately 99.9% of the bacteria were dead after a 60s exposure. After 10 and 30s, but not after 60s exposure to ozone, S. mutans and L. casei were less efficiently killed in saliva compared to the salt buffer. Various saliva proteins were degraded by ozone after a 60s exposure. The cariogenic species S. mutans, L. casei and A. naeslundii were almost eliminated following 60s of ozone treatment. This killing was reduced in the presence of saliva although increasing the ozone application time to 60s overcame these reductants in saliva. Detection of altered salivary proteins indicates that saliva components constitute additional targets for ozone.

  8. Antibacterial effect of cationic porphyrazines and anionic phthalocyanine and their interaction with plasmid DNA

    Science.gov (United States)

    Hassani, Leila; Hakimian, Fatemeh; Safaei, Elham; Fazeli, Zahra

    2013-11-01

    Resistance to antibiotics is a public health issue and identification of new antibacterial agents is one of the most important goals of pharmacological research. Among the novel developed antibacterial agents, porphyrin complexes and their derivatives are ideal candidates for use in medical applications. Phthalocyanines differ from porphyrins by having nitrogen atoms link the individual pyrrol units. The aza analogues of the phthalocyanines (azaPcs) such as tetramethylmetalloporphyrazines are heterocyclic Pc analogues. In this investigation, interaction of an anionic phthalocyanine (Cu(PcTs)) and two cationic tetrapyridinoporphyrazines including [Cu(2,3-tmtppa)]4+ and [Cu(3,4-tmtppa)]4+ complexes with plasmid DNA was studied using spectroscopic and gel electrophoresis methods. In addition, antibacterial effect of the complexes against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria was investigated using dilution test method. The results indicated that both porphyrazines have significant antibacterial properties, but Cu(PcTs) has weak antibacterial effect. Compairing the binding of the phthalocyanine and the porphyrazines to DNA demonstrated that the interaction of cationic porphyrazines is stronger than the anionic phthalocyanine remarkably. The extent of hypochromicity and red shift of absorption spectra indicated preferential intercalation of the two porphyrazine into the base pairs of DNA helix. Gel electrophoresis result implied Cu(2,3-tmtppa) and Cu(3,4-tmtppa) are able to perform cleavage of the plasmid DNA. Consequently, DNA binding and cleavage might be one of the antibacterial mechanisms of the complexes.

  9. Disorder effects in strongly correlated uranium compounds

    International Nuclear Information System (INIS)

    Suellow, S.; Maple, M.B.; Tomuta, D.; Nieuwenhuys, G.J.; Menovsky, A.A.; Mydosh, J.A.; Chau, R.

    2001-01-01

    Moderate levels of crystallographic disorder can dramatically affect the ground-state properties of heavy fermion compounds. In particular, the role of disorder close to a quantum critical point has been investigated in detail. However, crystallographic disorder is equally effective in altering the properties of magnetically ordered heavy fermion compounds like URh 2 Ge 2 , where disorder-induced spin-glass behavior has been observed. In this system, moreover, the magnetic ground state can be tuned from a spin-glass to a long-range ordered antiferromagnetic one by means of an annealing treatment. The transformation of the magnetic state is accompanied by a transition in the transport properties from 'quasi-insulating' (dρ/dT 2 Ge 2 will be discussed. Of particular interest is the resistivity of as-grown URh 2 Ge 2 , which resembles the Non-Fermi-liquid system UCu 4 Pd, suggesting that a common mechanism - the crystallographic disorder - controls the transport properties of these materials

  10. Effect of extrusion processing on the microstructure, mechanical properties, biocorrosion properties and antibacterial properties of Ti-Cu sintered alloys.

    Science.gov (United States)

    Zhang, Erlin; Li, Shengyi; Ren, Jing; Zhang, Lan; Han, Yong

    2016-12-01

    Ti-Cu sintered alloys, Ti-Cu(S) alloy, have exhibited good anticorrosion resistance and strong antibacterial properties, but low ductility in previous study. In this paper, Ti-Cu(S) alloys were subjected to extrusion processing in order to improve the comprehensive property. The phase constitute, microstructure, mechanical property, biocorrosion property and antibacterial activity of the extruded alloys, Ti-Cu(E), were investigated in comparison with Ti-Cu(S) by X-ray diffraction (XRD), optical microscopy (OM), scanning electronic microscopy (SEM) with energy disperse spectroscopy (EDS), mechanical testing, electrochemical testing and plate-count method in order to reveal the effect of the extrusion process. XRD, OM and SEM results showed that the extrusion process did not change the phase constitute but refined the grain size and Ti2Cu particle significantly. Ti-Cu(E) alloys exhibited higher hardness and compressive yield strength than Ti-Cu(S) alloys due to the fine grain and Ti2Cu particles. With the consideration of the total compressive strain, it was suggested that the extrusion process could improve the ductility of Ti-Cu alloy(S) alloys. Electrochemical results have indicated that the extrusion process improved the corrosion resistance of Ti-Cu(S) alloys. Plate-count method displayed that both Ti-Cu(S) and Ti-Cu(E) exhibited strong antibacterial activity (>99%) against S. aureus. All these results demonstrated that hot forming processing, such as the extrusion in this study, refined the microstructure and densified the alloy, in turn improved the ductility and strength as well as anticorrosion properties without reduction in antibacterial properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. High frequency equipment promotes antibacterial effects dependent on intensity and exposure time

    Directory of Open Access Journals (Sweden)

    Wietzikoski Lovato EC

    2018-03-01

    Full Text Available Evellyn Claudia Wietzikoski Lovato,1 Patrícia Amaral Gurgel Velasquez,1 Cristiana dos Santos Oliveira,1 Camila Baruffi,1 Thais Anghinoni,1 Raquel Costa Machado,1 Francislaine Aparecida dos Reis Lívero,2 Samantha Wietzikoski Sato,1 Lisiane de Almeida Martins1 1Laboratory of Microbiology of Natural Products, Paranaense University, Umuarama, Brazil; 2Laboratory of Preclinical Research of Natural Products, Paranaense University, Umuarama, Brazil Background: The indiscriminate use of antibiotics has caused bacteria to develop mechanisms of resistance to antibacterial agents, limiting treatment options. Therefore, there is a great need for alternative methods to control infections, especially those related to skin. One of the alternative methods is the high frequency equipment (HFE, which is used on skin conditions as an analgesic, an anti-inflammatory, and mainly to accelerate cicatricial processes and have a bactericidal effect through the formation of ozone. This research investigated the antibacterial effect of HFE on standard cultures of bacteria.Materials and methods: Dilutions (104 colony forming unit mL−1 were performed for Enterobacter aerogenes and Staphylococcus aureus with 24-hour growth bacteria. Then, 1 μL of each dilution was pipetted into suitable medium and the HFE flashing technique was used at intensities of 6, 8 and 10 mA for 30, 60, 90, 120 and 180 seconds. The control group received no treatment. Plates were incubated at 37°C for 24 hours and then read.Results: The spark at intensity of 6 mA had no bactericidal effect on the E. aerogenes; however, a significant bacterial growth reduction occurred at intensity of 8 mA after 120 and 180 seconds, and at 10 mA, reduction in bacterial growth could already be verified at 30 seconds and total bacterial growth inhibition occurred in 180 seconds. For S. aureus, there was a strong bacterial growth inhibition at all intensities used; however, at 6 mA, absence of bacterium growth after

  12. Antibacterial and toxicological effects of leaf extracts of Eurphorbia ...

    African Journals Online (AJOL)

    Aim: A study was carried out to determine the antibacterial activity of Euphorbia heterophylla crude extracts on four enteric bacterial organisms namely; Salmonella typhi, Shigella flexneri, E.coli and Proteus vulgaris. Method: The clinical isolates of Salmonella typhi, Shigella flexneri, E.coli and Proteus vulgaris were ...

  13. Preparation, characterization and antibacterial effects of eco-friendly ...

    African Journals Online (AJOL)

    688. 14. Daglia M, Papetti A, Grisoli P, Aceti C, Dacarro C,. Gazzani G. Antibacterial activity of red and white wine against oral streptococci. J. Agric. Food Chem. 2007;. 55: 5038–5042. 15. Jarvinen H, Tenovuo J, Huovinen P. In vitro susceptibility.

  14. phytochemical analysis and antibacterial effects of crude extracts of ...

    African Journals Online (AJOL)

    2015-04-30

    Apr 30, 2015 ... process (Fajimi et al., 2004), while Dogon-yaro (Azadiractha indica) has analgesic and antibacterial properties. (Obadoni and ... Echeme (2013) showed that naphthalene pentenoic acid from ethanol extract of the stem bark of B. eurycoma has ... Cardiac glycosides (glacial acetic acid + FeCl3 + H2SO4.); ...

  15. Antibacterial effects of some Cameroonian medicinal plants against ...

    African Journals Online (AJOL)

    We screened forty crude extracts of twenty Cameroonian medicinal plants commonly used to treat bacterial infections for broad spectrum antibacterial activity, as a more affordable alternative against resistant organisms. The extracts were screened on common pathogenic gram negative and gram positive bacteria initially ...

  16. Antibacterial effects of zinc oxide nanoparticles on Escherichia coli ...

    African Journals Online (AJOL)

    To study the antibacterial mechanisms, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to observe morphological changes of E. coli K88 treated with 0.8 μg/ml zinc oxide nanoparticles. The results reveal that zinc oxide nanoparticles could damage cell membranes, lead to leakage of ...

  17. Antibacterial and antiviral effects of milk proteins and derivatives thereof

    NARCIS (Netherlands)

    Florisa, René; Recio, Isidra; Berkhout, Ben; Visser, Servaas

    2003-01-01

    Milk forms a rich source of biologically interesting components. In particular, its protein fraction is known to encompass many kinds of biological functions. In this review we focus on antibacterial and antiviral proper-ties of milk proteins and milk protein derivatives. The latter include

  18. [Antibacterial effect of self-etching adhesive systems on Streptococcus mutans].

    Science.gov (United States)

    Zhang, Lu; Yuan, Chong-yang; Tian, Fu-cong; Wang, Xiao-yan; Gao, Xue-jun

    2016-02-18

    To investigate the antibacterial effect of different self-etching adhesive systems against Streptococcus mutans (S. mutans). Six reagents Clearfil(TM) SE Bond primer (SP), Clearfil(TM) SE Bond adhesive (SA),Clearfil(TM) Protect Bond primer (PP), which contained antibacterial monomer methacryloyloxydodecylpyridinium bromide (MDPB), ClearfilTM Protect Bond adhesive (PA), positive control chlorhexidine acetate [CHX, 1% (mass fraction)], and negative control phosphate buffer solution (PBS) were selected. They were mixed with S. mutans for 30 s respectively, then colony-forming units (CFU) were counted after incubated for 48 h on brain heart infusion (BHI) agar medium. The 6 reagents were applied to the sterile paper discs, and distributed onto the BHI agar medium with S. mutans and incubated for 24 h, then the inhibition zones were observed. CHX, PBS, PP, and SP were added on the dentin with artificial caries induced by S. mutans and kept for 30 s, then confocal laser scanning microscope (CLSM) was used to observe the live and dead bacteria after staining. The ratio of live to dead bacteria was calculated. PP+PA and SP+SA were applied on the dentin according to the manual and light cured. S. mutans were incubated on the samples for 2 h, ultrasonically treated and incubated on BHI agar medium for 48 h, then CFU was counted. The data were analyzed by non-parametric analysis and one-way ANOVA. Compared with PBS, the PP, SP, PA, SA and CHX showed the antibacterial effect on free S. mutans (Padhesive systems did not show any antibacterial effect on the free S. mutans. The primer of self-etching adhesives Clearfil(TM) SE Bond and Clearfil(TM) Protect Bond showed significant antibacterial effect on free and attached S. mutans. The adhesive only showed antibacterial effect on free S. mutans before light-cured polymerization. After being cured, the self-etching adhesive systems did not show antibacterial effect anymore.

  19. Antibacterial effect of theaflavin, polyphenon 60 (Camellia sinensis) and Euphorbia hirta on Shigella spp.--a cell culture study.

    Science.gov (United States)

    Vijaya, K; Ananthan, S; Nalini, R

    1995-12-01

    Antibacterial effect of compounds extracted from Camellia sinensis L. and the methanol extract of Euphorbia hirta L. were studied against dysentery causing Shigella spp. using the Vero cell line. Cytotoxicity studies of the extracts were performed using the cell line and the non-cytotoxic concentration of the extract was tested for antibacterial activity against the cytopathic dose of the pathogen. These extracts were found to be non-cytotoxic and effective antibacterial agents.

  20. Evaluation of antibacterial effect of Myrtus communis against Acinetobacter baumannii clinical strains

    Directory of Open Access Journals (Sweden)

    Venous Akhavan

    2016-09-01

    Full Text Available Because of inappropriate use of antibiotics and prevalence of resistant bacteria, there is urgent need for antibacterial drugs that have fewer side effects than antibiotics. Myrtus communis is a medicinal plant which had many uses in traditional medicine. In this study, ethanol leave extract of this plant is tested on Acinetobacter baumannii. In the case of antimicrobial evaluation of plants, one of the effecting factors on effectiveness of the microbial inhibition is extraction techniques. In the presents study, the antibacterial activity of the Ethanol, Methanol, and Ethyl acetate extracts of M. communis plant was evaluated at seven different concentrations by broth microdilution method. The results of this study showed that the antimicrobial effect of M. communis extract is concentration dependent. Different extracts were obtained by the maceration method. Extracts of the plant exhibited antibacterial activity at varied levels against A. baumannii. Obtained results from our antibacterial experiments showed that all extracts have anti-bacterial activity against tested bacterial isolates According to the results, the ethyl acetate extracted fraction showed the highest level of activity at a MIC 400 mg/ml for A. baumannii. The results of this study indicate that, different extracts had growth inhibitory effect on A. baumannii. Therefore this plant has the potential to be evaluated as an alternative or adjunct to antibiotics to treat Acinetobacter infections.

  1. Nanosilver-Silica Composite: Prolonged Antibacterial Effects and Bacterial Interaction Mechanisms for Wound Dressings.

    Science.gov (United States)

    Mosselhy, Dina A; Granbohm, Henrika; Hynönen, Ulla; Ge, Yanling; Palva, Airi; Nordström, Katrina; Hannula, Simo-Pekka

    2017-09-06

    Infected superficial wounds were traditionally controlled by topical antibiotics until the emergence of antibiotic-resistant bacteria. Silver (Ag) is a kernel for alternative antibacterial agents to fight this resistance quandary. The present study demonstrates a method for immobilizing small-sized (~5 nm) silver nanoparticles on silica matrix to form a nanosilver-silica (Ag-SiO₂) composite and shows the prolonged antibacterial effects of the composite in vitro. The composite exhibited a rapid initial Ag release after 24 h and a slower leaching after 48 and 72 h and was effective against both methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli ( E . coli ). Ultraviolet (UV)-irradiation was superior to filter-sterilization in retaining the antibacterial effects of the composite, through the higher remaining Ag concentration. A gauze, impregnated with the Ag-SiO₂ composite, showed higher antibacterial effects against MRSA and E . coli than a commercial Ag-containing dressing, indicating a potential for the management and infection control of superficial wounds. Transmission and scanning transmission electron microscope analyses of the composite-treated MRSA revealed an interaction of the released silver ions with the bacterial cytoplasmic constituents, causing ultimately the loss of bacterial membranes. The present results indicate that the Ag-SiO₂ composite, with prolonged antibacterial effects, is a promising candidate for wound dressing applications.

  2. Antibacterial synergistic effect of chlorhexidine and hydrogen peroxide against Streptococcus sobrinus, Streptococcus faecalis and Staphylococcus aureus.

    Science.gov (United States)

    Steinberg, D; Heling, I; Daniel, I; Ginsburg, I

    1999-02-01

    Chlorhexidine (CHX) and Hydrogen peroxide (HP) are potent antibacterial agents that are used in controlling dental plaque. However, both agents bear undesired side-effects. We have tested the hypothesis that an antibacterial synergistic effect can occur between the two agents against Streptococcus sobrinus, Streptococcus faecalis and Staphylococcus aureus. We have found that at several combinations of HP and CHX an antibacterial synergistic effect does occur, while at other combinations a on-significant synergism was noticed. No antagonism between the two agents was found in our experimental system. It can be postulated that the mechanism of this synergistic effect is via alteration of the bacterial cell-surface by CHX thereby allowing for an increased amount of HP to penetrate and to react with the intercellular organelles of the bacteria. These results suggest that CHX and HP can be of use in controlling the dental plaque in the oral cavity.

  3. [COMPARATIVE ANALYSIS OF ANTIBACTERIAL EFFECT OF PHYTOANTIBIOTICS AND ANTIBIOTICS].

    Science.gov (United States)

    Akhvlediani, L; Koiava, T; Lomtadze, L; Joxadze, M; Msxiladze, L; Berashvili, D; Bakuridze, A

    2016-11-01

    The objective of this study was to determine the antibacterial activity of individual medicines and containing sum of the phyto-extracts against the bacteria causing nosocomial infections in compare to antibiotics. In the investigation were involved four strains of gram-negative bacteria Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Acinetobacter spp. Each object was investigated on antibiotic resistance using Kirby-Bauer diffusion method on 22 types of antibiotics. The objects of the study were: Sanguinarine, Chelerythrine and Berberine hydrochloride (of lab quality); essential oils and aromatic waters of Eucalyptus, Salvia and Lavanda. For determination their antibacterial activity was used Raits serological dilution method with adaptation. The results show that the antibiotic resistant bacteria did not rise in non-diluted and 1:1 diluted test-tubes. In 1:5 diluted test-tubes was observed a little turbidity and growth, as for in other test-tubes - intensive growth. The investigated phyto-medicines show the higher antibacterial activity than the antibiotics.

  4. Effect of gamma irradiation on fluoride release and antibacterial activity of resin dental materials

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fabiola Galbiatti de; Fucio, Suzana Beatriz Portugal de; Correr-Sobrinho, Lourenco [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Dept. of Dental Materials; Pascon, Fernanda Miori; Kantovitz, Kamila Rosamilia; Puppin-Rontani, Regina Maria [Universidade Estadual de Campinas (UNICAMP), Piracicaba, SP (Brazil). Piracicaba Dental School. Dept. of Pedriatric Dentistry], e-mail: rmpuppin@fop.unicamp.br

    2009-07-01

    This study evaluated the effect of gamma irradiation on fluoride release and antibacterial activity of FluroShield (FS) and Clearfil Protect Bond (CPB). Four groups were formed: G1-FS + gamma; G2-FS without gamma; G3-CPB + gamma; G4-CPB without gamma. For fluoride release analysis, 12 disks of each material were prepared and covered with nail polish, except for one side (50.4 mm{sup 2} area). G1 and G3 were sterilized with a 14.5 KGy dose at 27 deg C for 24 h, while G2 and G4 (controls) were not sterilized and were maintained under the same time and temperature conditions. Fluoride release measurements were made in duplicate (n=6) by an ion specific electrode. The antibacterial activity of the CPB and FS against Streptococcus mutans after gamma sterilization was evaluated by the agar-disc diffusion method. The diameter of the zones of microbial growth inhibition was recorded after 48 h. Data were analyzed statistically by ANOVA and Tukey's test (alpha=5%). Gamma sterilization decreased the fluoride release of FS by approximately 50%, while CPB was not affected. There was no statistically significant difference (p>0.05) in the antibacterial effect of CPB between gamma and non-gamma sterilization groups. FS presented no antibacterial activity. Gamma irradiation decreased the fluoride release of FS, but did not affect the antibacterial activity of the studied materials. (author)

  5. Effect of gamma irradiation on fluoride release and antibacterial activity of resin dental materials

    International Nuclear Information System (INIS)

    Carvalho, Fabiola Galbiatti de; Fucio, Suzana Beatriz Portugal de; Correr-Sobrinho, Lourenco; Pascon, Fernanda Miori; Kantovitz, Kamila Rosamilia; Puppin-Rontani, Regina Maria

    2009-01-01

    This study evaluated the effect of gamma irradiation on fluoride release and antibacterial activity of FluroShield (FS) and Clearfil Protect Bond (CPB). Four groups were formed: G1-FS + gamma; G2-FS without gamma; G3-CPB + gamma; G4-CPB without gamma. For fluoride release analysis, 12 disks of each material were prepared and covered with nail polish, except for one side (50.4 mm 2 area). G1 and G3 were sterilized with a 14.5 KGy dose at 27 deg C for 24 h, while G2 and G4 (controls) were not sterilized and were maintained under the same time and temperature conditions. Fluoride release measurements were made in duplicate (n=6) by an ion specific electrode. The antibacterial activity of the CPB and FS against Streptococcus mutans after gamma sterilization was evaluated by the agar-disc diffusion method. The diameter of the zones of microbial growth inhibition was recorded after 48 h. Data were analyzed statistically by ANOVA and Tukey's test (alpha=5%). Gamma sterilization decreased the fluoride release of FS by approximately 50%, while CPB was not affected. There was no statistically significant difference (p>0.05) in the antibacterial effect of CPB between gamma and non-gamma sterilization groups. FS presented no antibacterial activity. Gamma irradiation decreased the fluoride release of FS, but did not affect the antibacterial activity of the studied materials. (author)

  6. Antibacterial effect of clove (Eugenia aromaticum oil extracted from clove cigarettes towards Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Ahmad Alif Wazir bin Jumali

    2018-01-01

    Full Text Available Streptococcus mutans is a commensal bacteria of the oral cavity, particularly found in dental plaque attached to the tooth surface, and can also found in the saliva, buccal mucosa, tongue, and the gingival sulcus. Clove cigarette contains the clove oil used worldwide as a herbal remedy for a variety of health disorders due to its antibacterial, antifungal, and antiviral properties. The purpose of this study was to determined the antibacterial effect of the clove oil contained in the clove cigarette towards Streptococcus mutans as a cariogenic bacteria. The research was an experimental laboratory, which tested the sensitivity of the Streptococcus mutans bacteria taken from the saliva of 10 clove cigarette smokers towards the clove oil extract of the clove cigarette in-vitro by using the Kirby-Bauer method. The study showed that the clove oil extract of the clove cigarette which contained eugenol has antibacterial towards the growth of Streptococcus mutans, and there was a difference of the antibacterial activity between clove oil extracted from minced and combusted clove cigarette. The conclusion of this study was the clove oil extracted from minced clove cigarette had a better antibacterial effect than the combusted clove cigarette.

  7. Anti-bacterial effects of the essential oil of Teucrium polium L. on human pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Mohammad Mohammad

    2013-09-01

    Results: The total oil content of Teucrium polium plant was 0.75%. Twenty eight compounds were identified in the essential oil that included 99.75% of the total oil. The major components were α-pinene (12.52%, Linalool (10.63% and Caryophyllene oxide (9.69%. For study of antimicrobial activity of the oil sample, the essential oil was tested against 9 bacteria by disc diffusion method. The antimicrobial effects of this essential oil was determined against three Gram positive bacteria Staphylococcus areous (PTCC 1431, Staphylococcus epidermidis (PTCC 1436, Streptococcus faecalis (PTCC 1237; as well as six Gram negative bacteria Pseudomonas aeroginosa (PTCC 11430, Shigella flexneri (PTCC 1716, Kellebsiella pneuomonae(PTCC=1053, Salmonella typhi (PTCC=1609, Serratia marcescens (PTCC 1187 and Escherichia coli (PTCC 1533. The antimicrobial effects of this essential oil on the Gram positive bacteria ( Staphylococcus aureus and Staphylococcus epidermidis and on all the Gram negative bacteria tested was much higher than those observed by tetracycline. Conclusions: The results showed the essential oil of Teucrium polium had strong anti-bacterial effects. The relatively high contents of α-pinene and Linalool in the essential oil may be the cause of its potential medicinal effects

  8. Antibacterial Effect of Carvacrol and Coconut Oil on Selected Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Božik M.

    2018-03-01

    Full Text Available Essential oils play a prominent role as flavouring agents and fragrances in the food and perfume industries. Carvacrol is a major component of various essential oils, such as oregano and thyme oils, and is responsible for their antimicrobial activity. Lauric acid is a medium-chain fatty acid (MCFA with a high antibacterial potential. Both carvacrol and MCFAs have been used empirically as antimicrobial agents. Here, we tested the inhibitory properties of carvacrol and coconut (Cocos nucifera L. oil containing a high percentage of MCFAs against 5 harmful bacterial pathogens: Escherichia coli, Salmonella Enteritidis, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus cecorum. Gas chromatography (GC-FID analysis of coconut oil showed a high concentration of lauric acid (41%. Microdilution antimicrobial assays showed that the combination of carvacrol and coconut oil had a stronger antibacterial effect against all tested bacteria than both agents separately. We conclude that carvacrol could significantly improve the antibacterial effect of coconut oil.

  9. OBSERVATION OF STRONG - STRONG AND OTHER BEAM - BEAM EFFECTS IN RHIC

    International Nuclear Information System (INIS)

    FISCHER, W.; BLASKIEWICZ, M.; BRENNAN, J.M.; CAMERON, P.; CONNOLLY, R.; MONTAG, C.; PEGGS, S.; PILAT, F.; PTITSYN, V.; TEPIKIAN, S.; TRBOJEVIC, D.; VAN ZEIJTS, J.

    2003-01-01

    RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. For the first time, coherent beam-beam modes were observed in a bunched beam hadron collider. Other beam-beam effects in RHIC were observed in operation and in dedicated experiments with gold ions, deuterons and protons. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. During ramps unequal radio frequencies in the two rings cause the crossing points to move longitudinally. Thus bunches experience beam-beam interactions only in intervals and the tunes are modulated. In this article we summarize the most important beam-beam observations made so far

  10. The Antibacterial Effect of Methanolic and Aqueous Extracts of Stachys schtschegleevii (Poulk Leave on Bacteria Causing Urinary Infection

    Directory of Open Access Journals (Sweden)

    Atefe Bayat

    2015-12-01

    Full Text Available Background and Objectives: The medical herb Poulk is used for the treatment of infectious diseases in urinary tract, vagina, respiratory tract, rheumatism, ear infections, and other inflammatory conditions. In this study, the antibacterial effect of methanolic and aqueous extracts of Poulk on bacterial infection of urine, was investigated. Methods: In this experimental study, techniques for determining minimum inhibitory concentration (MIC of bacterial growth, minimum bactericidal concentration (MBC, and disk diffusion were used to investigate the antibacterial effects of Poulk on the mentioned bacteria. Data were analyzed using analysis of variance and Duncan’s tests. Significance level was considered p<0.05. Results: In this study, Staphylococcus aureus, Klebsiella pneumoniae, and Enterobacter aerogenes bacteria showed sensitivity to aqueous and methanolic extracts of Poulk in different concentrations. Proteus mirabilis bacteria with an inhibition zone diameter of (2.00±0.2 mm was the most resistant and Staphylococcus aureus bacteria with an inhibition zone diameter of (20.50±0.2mm was the most sensitive bacteria to the extract effect. The effect of methanolic and aqueous extracts on staphylococcus aureus was the same. Hydro-methanolic extracts showed MIC and MBC, but aqueous extracts had no bactericidal effect on the bacteria. Conclusion: The findings of this research indicate that aqueous and methanolic extracts of poulk have strong antibacterial effects                on Enterobacter aerogenes and Klebsiella pneumoniae, and Staphylococcus aureus (bacteria causing urinary infections, but no effect on Proteus mirabilis.

  11. Study of Antibacterial Effect of Novel Thiazole, Imidazole and Tetrahydropyridine Derivatives against Escherichia coli

    Directory of Open Access Journals (Sweden)

    Behzad Ghasemi

    2016-01-01

    Full Text Available > Introduction: Escherichia coli is one of the important pathogens in human with globalimportance. Because of the necessity for identification and the use of novel antibacterialcompounds against E. coli, in this present study we focused on the antibacterial effects ofsynthesized thiazole, imidazole and tetrahydropyridine derivatives on E. coli.Methods: For evaluation of antibacterial effect, the disk diffusion method was applied to measurethe growth inhibition zone diameter and broth micro-dilution was performed to determine theminimum inhibitory concentration (MIC.Results: Assessing the antibacterial effect showed that only 6d derivative of thiazole hadinhibitory effect on E. coli and the other thiazole, imidazole and tetrahydropyridine derivativeslacked any inhibitory result on this organism. The inhibitory effect of 6d derivative of thiazolewas MIC=125 and growth inhibition zone diameter of 16±0.1.Discussion: The antibacterial effect of thiazole, imidazole and tetrahydropyridine derivativesdiffers from each other and chemical linkages such as oxygen to thiazole ring in 6d derivative,could have reinforced this effect. The next step is determination of the toxicity and therapeuticeffects in the laboratory animals.

  12. Assessing antibacterial effect of filter media coated with silver nanoparticles against Bacillus spp

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    Mahmood Nafisi Bahabadi

    2016-04-01

    Full Text Available Background: Nanotechnology is a field of applied science and technology covering a broad range of topics. Use of nanotechnology and especially silver nanoparticles in control of bacterial diseases and infections has been studied in the recent years. The aim of the present study was to investigate the in vitro antibacterial effect of filter media coated with silver nanoparticles against Bacillus spp. Materials and methods: In this research, first, the antibacterial effects of silver nanoparticles against mentioned bacteria were evaluated by microdilution method in Broth medium. After confidence of inhibitory effect of colloidal silver nanoparticles, antibacterial effect of filter media coated with silver nanoparticles was evaluated via in vitro microbiology tests (zone of inhibition test and test tube test. Results: Present study showed that colloidal silver nanoparticles have good antimicrobial effects against tested bacteria, so that MIC and MBC of silver nanoparticles for Bacillus spp. were calculated 3.9 and 31.25 mg/L, respectively. Also significant decrease was observed in bacterial growth after exposure to filter media coated with silver nanoparticles in test tube test and  zone of inhibition test (P≤ 5%. Conclusion: The results of this research indicate that filter media coated with silver nanoparticles have considerable antimicrobial effects; therefore they could possibly be used as excellent antibacterial water filters and would have several applications in other sectors.

  13. Antioxidant, antibacterial and cytotoxic effects of the phytochemicals of whole Leucas aspera extract

    Science.gov (United States)

    Rahman, Md Atiar; Islam, Md Saiful

    2013-01-01

    Objective To investigate the antioxidant, antibacterial and cytotoxic activity of whole Leucas aspera (Labiatae) (L. aspera) alcoholic extract. Methods Whole L. aspera powder was extracted by absolute ethanol (99.50%). The ethanolic extract was subjected to antioxidant, antibacterial and brine shrimp lethality assay. Results The extract showed potent radical scavenging effect (antioxidant) with IC50 value of (99.58±1.22) µg/mL which was significant (Pshrimp lethality bioassay, the extract showed the LC50 value as (181.68±2.15) µg/mL which was statistically significant (Ppesticidal and various pharmacologic actives. PMID:23620850

  14. Antibacterial Effects of Natural Herbal Extracts on Streptococcus mutans: Can They Be Potential Additives in Dentifrices?

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    Spoorthi Banavar Ravi

    2017-01-01

    Full Text Available Background. Many plants or herbs exhibit potent antimicrobial activity against various microorganisms. They have no side effects and presumably act against and modulate the factors that are crucial for microbial survival or their activity. Streptococcus mutans is a pioneer bacteria implicated in dental caries. This study aims to evaluate the antimicrobial activity of garlic bulbs, pudina leaves, and mango and eucalyptus twig extracts on Streptococcus mutans by evaluating their zone of inhibition and determining their minimum inhibitory concentration (MIC. Methods. Microbiological assay (well diffusion method to determine zone of inhibition against pure forms of Streptococcus mutans was performed. The antibacterial effects of methanolic extracts of mango twigs, eucalyptus twigs, pudina leaves, and garlic bulbs were studied. Test compounds were further evaluated for their MIC. Results. Extracts derived from mango and eucalyptus twigs showed significant antibacterial effects at test concentrations. Pudina and garlic extracts did not show any significant antibacterial effects at similar concentrations. Upon further evaluation of the 2 positive compounds for their MIC, mango twigs demonstrated more antimicrobial potential than eucalyptus twigs at a lower concentration. Conclusion. Our observations indicated that the mango twig extracts possess higher antibacterial effects against Streptococcus mutans than other compounds at specific test concentration.

  15. An in vitro evaluation of antibacterial effect of silver nanoparticles on ...

    African Journals Online (AJOL)

    An in vitro evaluation of antibacterial effect of silver nanoparticles on Staphylococcus aureus isolated from bovine subclinical mastitis. ... The minimum inhibitory concentrations (MIC) distribution of the silver nanoparticles tested for S. aureus field isolates were determined by a broth dilution method. The results show MIC ...

  16. Antibacterial Effect of All-in-one Self-etch Adhesives on Enterococcus faecalis

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    Mohammad Esmaeel Ebrahimi Chaharom

    2014-12-01

    Full Text Available Background and aims. The aim of this study was to evaluate the antibacterial activity of one-step self-etch adhesives on Enterococcus faecalis on days 1, 7 and 14 with the use of modified direct contact test. Materials and methods. The modified directcontact test was used to evaluate the antibacterial effect of Adper Easy One, Bond Force, Clearfil S3 Bond, Futurabond M, G-Bond, iBond and OptiBond All-in-one adhesives on Enterococcus faecalisafter aging the samples in phosphate-buffered saline for one, seven and fourteen days. Data were analyzed using one-way ANOVA and post hoc Tukey tests. Aging effect of each adhesive was evaluated by paired-sample test. In this study, P0.05. Conclusion. iBond exhibited the highest antibacterial effect on E. faecalis after one week. Futurabond and OptiBond All-in-one exhibited antibacterial effects against E. faecalis for one week.

  17. Intratubular Antibacterial Effect of Polyethyleneimine Nanoparticles: An Ex Vivo Study in Human Teeth

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    Itzhak Abramovitz

    2015-01-01

    Full Text Available Enterococcus faecalis is a facultative gram positive bacterium which can remain in the teeth root canals and cause refractory or persistent periapical diseases. E. faecalis bacteria that penetrate the dentinal tubules can be the source of intracanal infection and endodontic disease. Quaternary ammonium polyethyleneimine (QPEI nanopolymers were shown to have long lasting antibacterial activity against gram positive and gram negative bacteria. The present study evaluated the intratubular antibacterial effect of an epoxy resin sealer incorporating 1% QPEI against E. faecalis in a human dentin model. Root canals of extracted teeth were inoculated with E. faecalis for 7 days prior to standard endodontic treatment. The antibacterial effect of an epoxy-amine resin endodontic sealer was tested at concentration of 0% or 1% (wt/wt added QPEI nanoparticles. Reduction in bacterial viability p<0.01 was depicted in the dentinal tubules of the root canals obturated with the sealer incorporating QPEI nanoparticles. In conclusion, QPEI nanoparticles when incorporated in a small percentage into epoxy-resin based sealer may target E. faecalis in the dentinal tubules, producing a potent antibacterial effect that reduces significantly bacterial viability.

  18. Green Synthesis and Antibacterial Effect of Silver Nanoparticles Using Vitex Negundo L.

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    Fatima Abu Bakar

    2011-08-01

    Full Text Available Different biological methods are gaining recognition for the production of silver nanoparticles (Ag-NPs due to their multiple applications. One of the most important applications of Ag-NPs is their use as an anti-bacterial agent. The use of plants in the synthesis of nanoparticles emerges as a cost effective and eco-friendly approach. In this study the biosynthesis of silver nanoparticles using Vitex negundo L. extract and its antimicrobial properties has been reported. The resulting silver particles are characterized using transmission electron microscopy (TEM, X-ray diffraction (XRD and UV–Visible (UV-Vis spectroscopic techniques. The TEM study showed the formation of silver nanoparticles in the 10–30 nm range and average 18.2 nm in size. The XRD study showed that the particles are crystalline in nature, with a face centered cubic (fcc structure. The silver nanoparticles showed the antimicrobial activity against Gram positive and Gram negative bacteria. Vitex negundo L. was found to display strong potential for the synthesis of silver nanoparticles as antimicrobial agents by rapid reduction of silver ions (Ag+ to Ag0.

  19. Comparison of methods for determining the effectiveness of antibacterial functionalized textiles.

    Science.gov (United States)

    Haase, Hajo; Jordan, Lisa; Keitel, Laura; Keil, Claudia; Mahltig, Boris

    2017-01-01

    Antimicrobial functionalization of textiles is important for various applications, such as protection of textile materials from decomposition, generation of more effective wound dressings, and the prevention of infections or malodors resulting from bacterial growth. In order to test the efficacy of new products, their antibacterial activity needs to be evaluated. At present, several different procedures are being used for this purpose, hindering comparisons among different studies. The present paper compares five of these assays using a sample panel of different textiles functionalized with copper (Cu) and silver (Ag) as antibacterial agents, and discusses the suitability of these methods for different analytical requirements. Bacterial viability was determined by measuring the optical density at 600 nm, a colorimetric assay based on MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide) conversion, an agar diffusion assay, and colony formation, either after culturing in media containing textile samples, or after recovery from textiles soaked with bacterial suspension. All experiments were performed with a Gram-negative (Escherichia coli) and a Gram-positive (Staphylococcus warneri) model organism. In general, the results yielded by the different methods were of good comparability. To identify the most suitable test system for the particular type of antibacterial coating, several factors need to be taken into account, such as choosing appropriate endpoints for analyzing passive or active antibacterial effects, selection of relevant microorganisms, correcting for potential interference by leaching of colored textile coatings, required hands on time, and the necessary sensitivity.

  20. The effect of lipophilicity on the antibacterial activity of some 1-benzylbenzimidazole derivatives

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    D. J. BARNA

    2008-10-01

    Full Text Available In the present paper, the antibacterial activity of some 1-benzylbenzimidazole derivatives were evaluated against the Gram-negative bacteria Escherichia coli. The minimum inhibitory concentration was determined for all the compounds. Quantitative structure–activity relationship (QSAR was employed to study the effect of the lipophilicity parameters (log P on the inhibitory activity. Log P values for the target compounds were experimentally determined by the “shake-flask” method and calculated by using eight different software products. Multiple linear regression was used to correlate the log P values and antibacterial activity of the studied benzimidazole derivatives. The results are discussed based on statistical data. The most acceptable QSAR models for the prediction of the antibacterial activity of the investigated series of benzimidazoles were developed. High agreement between the experimental and predicted inhibitory values was obtained. The results of this study indicate that the lipophilicity parameter has a significant effect on the antibacterial activity of this class of compounds, which simplifies the design of new biologically active molecules.

  1. Comparison of methods for determining the effectiveness of antibacterial functionalized textiles.

    Directory of Open Access Journals (Sweden)

    Hajo Haase

    Full Text Available Antimicrobial functionalization of textiles is important for various applications, such as protection of textile materials from decomposition, generation of more effective wound dressings, and the prevention of infections or malodors resulting from bacterial growth. In order to test the efficacy of new products, their antibacterial activity needs to be evaluated. At present, several different procedures are being used for this purpose, hindering comparisons among different studies. The present paper compares five of these assays using a sample panel of different textiles functionalized with copper (Cu and silver (Ag as antibacterial agents, and discusses the suitability of these methods for different analytical requirements. Bacterial viability was determined by measuring the optical density at 600 nm, a colorimetric assay based on MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide conversion, an agar diffusion assay, and colony formation, either after culturing in media containing textile samples, or after recovery from textiles soaked with bacterial suspension. All experiments were performed with a Gram-negative (Escherichia coli and a Gram-positive (Staphylococcus warneri model organism. In general, the results yielded by the different methods were of good comparability. To identify the most suitable test system for the particular type of antibacterial coating, several factors need to be taken into account, such as choosing appropriate endpoints for analyzing passive or active antibacterial effects, selection of relevant microorganisms, correcting for potential interference by leaching of colored textile coatings, required hands on time, and the necessary sensitivity.

  2. Effect of nano/micro-Ag compound particles on the bio-corrosion, antibacterial properties and cell biocompatibility of Ti-Ag alloys.

    Science.gov (United States)

    Chen, Mian; Yang, Lei; Zhang, Lan; Han, Yong; Lu, Zheng; Qin, Gaowu; Zhang, Erlin

    2017-06-01

    In this research, Ti-Ag alloys were prepared by powder metallurgy, casting and heat treatment method in order to investigate the effect of Ag compound particles on the bio-corrosion, the antibacterial property and the cell biocompatibility. Ti-Ag alloys with different sizes of Ag or Ag-compounds particles were successfully prepared: small amount of submicro-scale (100nm) Ti 2 Ag precipitates with solid solution state of Ag, large amount of nano-scale (20-30nm) Ti 2 Ag precipitates with small amount of solid solution state of Ag and micro-scale lamellar Ti 2 Ag phases, and complete solid solution state of Ag. The mechanical tests indicated that both nano/micro-scale Ti 2 Ag phases had a strong dispersion strengthening ability and Ag had a high solid solution strengthening ability. Electrochemical results shown the Ag content and the size of Ag particles had a limited influence on the bio-corrosion resistance although nano-scale Ti 2 Ag precipitates slightly improved corrosion resistance. It was demonstrated that the nano Ag compounds precipitates have a significant influence on the antibacterial properties of Ti-Ag alloys but no effect on the cell biocompatibility. It was thought that both Ag ions release and Ti 2 Ag precipitates contributed to the antibacterial ability, in which nano-scale and homogeneously distributed Ti 2 Ag phases would play a key role in antibacterial process. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Antibacterial and antibiofilm effects of iron chelators against Prevotella intermedia.

    Science.gov (United States)

    Moon, Ji-Hoi; Kim, Cheul; Lee, Hee-Su; Kim, Sung-Woon; Lee, Jin-Yong

    2013-09-01

    Prevotella intermedia, a major periodontopathogen, has been shown to be resistant to many antibiotics. In the present study, we examined the effect of the FDA-approved iron chelators deferoxamine (DFO) and deferasirox (DFRA) against planktonic and biofilm cells of P. intermedia in order to evaluate the possibility of using these iron chelators as alternative control agents against P. intermedia. DFRA showed strong antimicrobial activity (MIC and MBC values of 0.16 mg ml(-1)) against planktonic P. intermedia. At subMICs, DFRA partially inhibited the bacterial growth and considerably prolonged the bacterial doubling time. DFO was unable to completely inhibit the bacterial growth in the concentration range tested and was not bactericidal. Crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that DFRA significantly decreased the biofilm-forming activity as well as the biofilm formation, while DFO was less effective. DFRA was chosen for further study. In the ATP-bioluminescent assay, which reflects viable cell counts, subMICs of DFRA significantly decreased the bioactivity of biofilms in a concentration-dependent manner. Under the scanning electron microscope, P. intermedia cells in DFRA-treated biofilm were significantly elongated compared to those in untreated biofilm. Further experiments are necessary to show that iron chelators may be used as a therapeutic agent for periodontal disease.

  4. Screening of antibacterial effect of the Scrophularia Striata against E. coli in vitro

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    Sharafati-chaleshtori Reza

    2014-01-01

    Full Text Available Introduction: This study was aimed to evaluate the antimicrobial activity of the ethanol and aqueous extracts of Scrophularia striata plant on E. coli O157:H7 in vitro. Methods: In this experimental study the ethanol and aqueous extract of the plant was prepared and their antibacterial effects were determined using sink diffusion and broth macrodilution methods against the bacterium E. coli O157:H7. Results: The ethanol extract of Scrophularia striata plant had inhibitory effect on the E. coli O157:H7 in two methods of sink diffusion and macrodilution, but the aqueous extract of this plant had not antibacterial effect. The MIC and MBC amounts were obtained 90mg/ml and 100 mg/ml, respectively. Conclusion: Based on the present results that the ethanol extract of the Scrophularia Striata plant showed inhibitory effect on bacterium, more researches are recommended to evaluate its in vivo effects and to identify active compounds.

  5. Copper-polymer nanocomposites: An excellent and cost-effective biocide for use on antibacterial surfaces.

    Science.gov (United States)

    Tamayo, Laura; Azócar, Manuel; Kogan, Marcelo; Riveros, Ana; Páez, Maritza

    2016-12-01

    The development of polymer nanocomposites with antimicrobial properties has been a key factor for controlling or inhibiting the growth of microorganisms and preventing foodborne diseases and nosocomial infections. Commercially available antibacterial products based on silver-polymer are the most widely used despite the fact that copper is considerably less expensive. The incorporation of copper nanoparticles as antibacterial agents in polymeric matrices to generate copper-polymer nanocomposites have presented excellent results in inhibiting the growth of a broad spectrum of microorganisms. The potential applications in food packaging, medical devices, textiles and pharmaceuticals and water treatment have generated an increasing number of investigations on preparing copper based nanocomposites and alternative polymeric matrices, as potential hosts of nano-modifiers. This review presents a comprehensive compilation of previous published work on the subject, mainly related to the antimicrobial activity of copper polymer nanocomposites. Within all the phenomenology associated to antibacterial effects we highlight the possible mechanisms of action. We discuss the differences in the susceptibility of Gram negative and positive bacteria to the antibacterial activity of nanocomposites, and influencing factors. As well, the main applications of copper polymer-metal nanocomposites are described, considering their physical and chemical characteristics. Finally, some commercially available copper-polymer nanocomposites are described. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Preparation, antibacterial effects and corrosion resistant of porous Cu–TiO{sub 2} coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Haibo; Zhang, Xiangyu, E-mail: zhangxiangyu@tyut.edu.cn; Geng, Zhenhua; Yin, Yan; Hang, Ruiqiang; Huang, Xiaobo; Yao, Xiaohong; Tang, Bin

    2014-07-01

    Antibacterial TiO{sub 2} coatings with different concentrations of Cu (Cu–TiO{sub 2}) were prepared by micro-arc oxidation (MAO) on pre-sputtered CuTi films. The effect of Cu concentrations in CuTi films on the MAO process was investigated. The Cu–TiO{sub 2} coatings were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The corrosion resistance of Cu–TiO{sub 2} coatings was evaluated via potentiodynamic polarization method. The antibacterial properties were assessed by two methods: spread plate method and fluorescence staining. The experimental results demonstrate that the coatings are porous and consist of anatase phase, rutile phase and unoxidized titanium. The CuTi films are almost completely oxidized and the thickness of all MAO coatings is about 5–10 μm. Cu mainly exists as CuO in the TiO{sub 2} coatings. The Cu–TiO{sub 2} coatings exhibit excellent antibacterial activities, and the antibacterial rate gradually rise with the increase in Cu concentration in the MAO coatings. The corrosion resistance of MAO coatings is also improved slightly.

  7. Preparation, antibacterial effects and corrosion resistant of porous Cu–TiO2 coatings

    International Nuclear Information System (INIS)

    Wu, Haibo; Zhang, Xiangyu; Geng, Zhenhua; Yin, Yan; Hang, Ruiqiang; Huang, Xiaobo; Yao, Xiaohong; Tang, Bin

    2014-01-01

    Antibacterial TiO 2 coatings with different concentrations of Cu (Cu–TiO 2 ) were prepared by micro-arc oxidation (MAO) on pre-sputtered CuTi films. The effect of Cu concentrations in CuTi films on the MAO process was investigated. The Cu–TiO 2 coatings were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The corrosion resistance of Cu–TiO 2 coatings was evaluated via potentiodynamic polarization method. The antibacterial properties were assessed by two methods: spread plate method and fluorescence staining. The experimental results demonstrate that the coatings are porous and consist of anatase phase, rutile phase and unoxidized titanium. The CuTi films are almost completely oxidized and the thickness of all MAO coatings is about 5–10 μm. Cu mainly exists as CuO in the TiO 2 coatings. The Cu–TiO 2 coatings exhibit excellent antibacterial activities, and the antibacterial rate gradually rise with the increase in Cu concentration in the MAO coatings. The corrosion resistance of MAO coatings is also improved slightly.

  8. Antibacterial effects of chitosan-tripolyphosphate nanoparticles: impact of particle size molecular weight

    Science.gov (United States)

    Sarwar, Atif; Katas, Haliza; Zin, Noraziah Mohamad

    2014-07-01

    This study revealed not only the antibacterial potential of smaller chitosan-tripolyphosphate nanoparticles (CS-TPP NPs) over larger ones, but also the attempt has been made to demonstrate antibacterial mechanism of action of CS-TPP NPs on the bacterial cell membrane. Several aspects of low-molecular-weight (LMW) and high-molecular-weight (HMW) CS-TPP NPs were evaluated by their interactions with selected Gram-positive and Gram-negative bacteria. The interaction of CS-TPP NPs with synthetic phospholipid membranes was also evaluated using Fourier transform infrared spectroscopy. The permeabilities of the bacterial outer and inner membranes were evaluated by determining the uptake of a fluorescent probe, 1- N-phenylnaphthylamine, and the release of cytoplasmic β-galactosidase. The morphology of the bacteria treated with LMW and HMW CS-TPP NPs was investigated using transmission electron microscopy. Flow cytometric analysis was also performed for the quantification of dead and surviving bacteria. These studies indicated that the antibacterial effects of LMW CS-TPP NPs (196 and 394 nm) were superior to those HMW CS-TPP NPs (598 and 872 nm). These data indicated that the antibacterial activity of CS-TPP NPs was negatively correlated with particle size and molecular weight, and that CS-TPP NPs represent a promising antimicrobial adjunct.

  9. Effect of metal salts on antibacterial activity of zingiber officinale roscoe extract

    International Nuclear Information System (INIS)

    Sohail, T.; Yaqeen, Z.; Imran, H.; Rehman, Z.; Fatima, N.

    2013-01-01

    The antibacterial activity of ethanol extract of Zingiber Officinale Roscoe (ginger) and its combination with different salts like CuSO/sub 4/, ZnSO/sub 4/ and MnCl/sub 2/ was investigated. Both Gram positive and Gram negative bacteria were tested by agar diffusion method. The results showed that ethanol extract of Zingiber Officinale gave the maximum zone of inhibition at 50 mg/ml concentrations against Escherichia coli among Gram negative bacteria and against Staphylococcus aureus in Gram positive bacteria. However antibacterial activity of the ginger and metal salts combination was greater than activity of ethanol extract. These investigations indicate that though ethanol extract has antibacterial activity against Gram positive and Gram negative bacteria, ginger and metal salts complex has more inhibitory effect on microorganisms. Antibacterial activity was also compared with standard drug ampicillin. The minimum inhibitory concentration (MIC) of ginger extract and metal salts complexes against all test organisms ranged from 0.3125 to 2.5 mg/ml. (author)

  10. Long-term antibacterial characteristics and cytocompatibility of titania nanotubes loaded with Au nanoparticles without photocatalytic effects

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guomin [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Feng, Hongqing, E-mail: fenghongqing@binn.cas.cn [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing 100083 (China); Jin, Weihong; Gao, Ang; Peng, Xiang; Li, Wan; Wu, Hao [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Li, Zhou [Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing 100083 (China); Chu, Paul K., E-mail: paul.chu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

    2017-08-31

    Highlights: • Au@TiO{sub 2}-NT shows long-term antibacterial effects without photocatalytical effects. • An ROS-free antibacterial process is confirmed. • Au@TiO{sub 2}-NT shows good compatibility with osteoblasts and does not induce ROS production. - Abstract: Au nanoparticles (NPs) can endow titania nanotubes (Au@TiO{sub 2}-NT) with light-independent antibacterial properties which bode well for in vivo application because of the dark environment inside tissues. In this work, the long-term antibacterial bactericidal properties and cytocompatibility of Au@TiO{sub 2}-NT without photocatalytic effects are studied in details. The materials exhibit antibacterial effects against Staphylococcus aureus according to antibacterial tests carried out for a total time of 21 days, which are normally long enough for early stage tissue healing after surgery. In addition, adhesion and proliferation of MC3T3-E1 osteoblasts on Au@TiO{sub 2}-NT reveal cytocompatibility comparable to that of TiO{sub 2}-NT. No reactive oxygen species (ROS) are detected from either the bacteria or MC3T3-E1 cells cultured on the Au@TiO{sub 2}-NT surface. The absence of ROS, long-term antibacterial properties, and cytocompatibility make Au@TiO{sub 2}-NT promising biomaterials in orthopedic devices and implants.

  11. Effect of dimethylaminohexadecyl methacrylate mass fraction on fracture toughness and antibacterial properties of CaP nanocomposite

    Science.gov (United States)

    Wu, Junling; Zhou, Han; Weir, Michael D.; Melo, Mary Anne S.; Levine, Eric D.; Xu, Hockin H. K.

    2015-01-01

    Objectives Biofilm acids contribute to secondary caries which is a reason for restoration failure. Previous studies synthesized nanoparticles of amorphous calcium phosphate (NACP) and dimethylaminohexadecyl methacrylate (DMAHDM). The objectives of this study were to develop DMAHMD-NACP nanocomposite for double benefits of antibacterial and remineralization capabilities, and investigate the DMAHMD mass fraction effects on fracture toughness and biofilm response of NACP nanocomposite for the first time. Methods DMAHDM was incorporated into NACP nanocomposite at mass fractions of 0% (control), 0.75%, 1.5%, 2.25% and 3%. A single edge V-notched beam method was used to measure fracture toughness Kic. A dental plaque microcosm biofilm model using human saliva as inoculum was used to measure the antibacterial properties of composites. Results Kic was about 1 MPa·m1/2 for all composite (mean ± sd; n = 6). Adding DMAHDM from 0% to 3% did not affect Kic (p > 0.1). Lactic acid production by biofilms on composite containing 3% DMAHDM was reduced to less than 1% of that on composite control. Metabolic activity of adherent biofilms on composite containing 3% DMAHDM was reduced to 4% of that on composite control. Biofilm colony-forming unit (CFU) counts were reduced by three orders of magnitude on NACP nanocomposite containing 3% DMAHDM. Conclusions DMAHDM-NACP nanocomposite had good fracture resistance, strong antibacterial potency, and NACP for remineralization (shown in previous studies). The DMAHDM-NACP nanocomposite may be promising for caries-inhibiting dental restorations, and the method of using double agents (DMAHDM and NACP) may have a wide applicability to other dental materials including bonding agents and cements. PMID:26404407

  12. Effect of dimethylaminohexadecyl methacrylate mass fraction on fracture toughness and antibacterial properties of CaP nanocomposite.

    Science.gov (United States)

    Wu, Junling; Zhou, Han; Weir, Michael D; Melo, Mary Anne S; Levine, Eric D; Xu, Hockin H K

    2015-12-01

    Biofilm acids contribute to secondary caries which is a reason for restoration failure. Previous studies synthesized nanoparticles of amorphous calcium phosphate (NACP) and dimethylaminohexadecyl methacrylate (DMAHDM). The objectives of this study were to develop DMAHMD-NACP nanocomposite for double benefits of antibacterial and remineralization capabilities, and investigate the DMAHMD mass fraction effects on fracture toughness and biofilm response of NACP nanocomposite for the first time. DMAHDM was incorporated into NACP nanocomposite at mass fractions of 0% (control), 0.75%, 1.5%, 2.25% and 3%. A single edge V-notched beam method was used to measure fracture toughness K(IC). A dental plaque microcosm biofilm model using human saliva as inoculum was used to measure the antibacterial properties of composites. K(IC) was about 1 MPa×m(1/2) for all composite (mean±sd; n=6). Adding DMAHDM from 0% to 3% did not affect K(IC) (p>0.1). Lactic acid production by biofilms on composite containing 3% DMAHDM was reduced to less than 1% of that on composite control. Metabolic activity of adherent biofilms on composite containing 3% DMAHDM was reduced to 4% of that on composite control. Biofilm colony-forming unit (CFU) counts were reduced by three orders of magnitude on NACP nanocomposite containing 3% DMAHDM. DMAHDM-NACP nanocomposite had good fracture resistance, strong antibacterial potency, and NACP for remineralization (shown in previous studies). The DMAHDM-NACP nanocomposite may be promising for caries-inhibiting dental restorations, and the method of using double agents (DMAHDM and NACP) may have a wide applicability to other dental materials including bonding agents and cements. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Ozone correlates with antibacterial effects from indirect air dielectric barrier discharge treatment of water

    International Nuclear Information System (INIS)

    Pavlovich, Matthew J; Chang, Hung-Wen; Sakiyama, Yukinori; Clark, Douglas S; Graves, David B

    2013-01-01

    Ambient-condition air plasma produced by indirect dielectric barrier discharges can rapidly disinfect aqueous solutions contaminated with bacteria and other microorganisms. In this study, we measured key chemical species in plasma-treated aqueous solutions and the associated antimicrobial effect for varying discharge power densities, exposure times, and buffer components in the aqueous medium. The aqueous chemistry corresponded to air plasma chemistry, and we observed a transition in composition from ozone mode to nitrogen oxides mode as the discharge power density increased. The inactivation of E. coli correlates well with the aqueous-phase ozone concentration, suggesting that ozone is the dominant species for bacterial inactivation under these conditions. Published values of ozone-water antibacterial inactivation kinetics as a function of the product of ozone concentration and contact time are consistent with our results. In contrast to earlier studies of plasma-treated water disinfection, ozone-dependent bacterial inactivation does not require acidification of the aqueous medium and the bacterial inactivation rates are far higher. Furthermore, we show that the antimicrobial effect depends strongly on gas-liquid mixing following plasma treatment, apparently because of the low solubility of ozone and the slow rate of mass transfer from the gas phase to the liquid. Without thorough mixing of the ozone-containing gas and bacteria-laden water, the antimicrobial effect will not be observed. However, it should be recognized that the complexity of atmospheric pressure plasma devices, and their sensitivity to subtle differences in design and operation, can lead to different results with different mechanisms. (paper)

  14. NEW THERAPEUTIC FORMULATIONS WITH AN ANTIBACTERIAL EFFECT, BASED ON PLANT EXTRACTS

    Directory of Open Access Journals (Sweden)

    Liliana Cristina Soare

    2012-12-01

    Full Text Available The antibacterial effects produced by anthocyanins and other bioactive plant compounds are weaker than those generated by antibiotics. In some cases, the combination of extract-antibiotic can cause synergistic effects, also the purpose of the research was to develop and test new antibiotic - plant extract formulations. New potential antimicrobial formulations was done by soaking discs impregnated with piperacillin or tetracycline with different extract. The tested microorganisms were: Staphylococcus aureus ATCC 25923, Streptococcus sp., Escherichia coli 820B, soil bacterium 23S, and Enterobacter cloacae. The combination of antibiotics with extracts determined, only for some of the microorganisms tested, better antibacterial effects than those caused by the antibiotic or the extract.

  15. Microbicidal effects of plain soap vs triclocarban-based antibacterial soap.

    Science.gov (United States)

    Kim, S A; Rhee, M S

    2016-11-01

    The aim of this study was to determine the bactericidal effects of plain and antibacterial soap. The bactericidal effects of plain and antibacterial soap containing 0.3% triclocarban were examined against 10 Gram-positive and 10 Gram-negative bacterial strains after exposure at 22°C and 40°C for 20 s. Gram-negative bacteria were more susceptible to both soaps than Gram-positive bacteria. However, with one exception (Enterococcus faecalis ATCC 19433 at 40°C), there was no significant difference between the effects of medicated and non-medicated soap at either temperature. Triclocarban in soap does not lead to a meaningful reduction in bacterial levels during use. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  16. Antibacterial effect of citrus press-cakes dried by high speed and far-infrared radiation drying methods

    Science.gov (United States)

    Samarakoon, Kalpa; Senevirathne, Mahinda; Lee, Won-Woo; Kim, Young-Tae; Kim, Jae-Il; Oh, Myung-Cheol

    2012-01-01

    In this study, the antibacterial effect was evaluated to determine the benefits of high speed drying (HSD) and far-infrared radiation drying (FIR) compared to the freeze drying (FD) method. Citrus press-cakes (CPCs) are released as a by-product in the citrus processing industry. Previous studies have shown that the HSD and FIR drying methods are much more economical for drying time and mass drying than those of FD, even though FD is the most qualified drying method. The disk diffusion assay was conducted, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined with methanol extracts of the dried CPCs against 11 fish and five food-related pathogenic bacteria. The disk diffusion results indicated that the CPCs dried by HSD, FIR, and FD prevented growth of all tested bacteria almost identically. The MIC and MBC results showed a range from 0.5-8.0 mg/mL and 1.0-16.0 mg/mL respectively. Scanning electron microscopy indicated that the extracts changed the morphology of the bacteria cell wall, leading to destruction. These results suggest that CPCs dried by HSD and FIR showed strong antibacterial activity against pathogenic bacteria and are more useful drying methods than that of the classic FD method in CPCs utilization. PMID:22808341

  17. Antibacterial Activity of Silver Nanoparticle-Loaded Soft Contact Lens Materials: The Effect of Monomer Composition.

    Science.gov (United States)

    Shayani Rad, Maryam; Khameneh, Bahman; Sabeti, Zahra; Mohajeri, Seyed Ahmad; Fazly Bazzaz, Bibi Sedigheh

    2016-10-01

    In the present work, the effect of monomer composition on silver nanoparticles' (SNPs) binding capacity of hydrogels was investigated and their antibacterial efficacy was evaluated. Three series of poly-hydroxyethyl methacrylate (HEMA) hydrogels were prepared using methacrylic acid (MAA), methacrylamide (MAAM), and 4-vinylpyridine (4VP) as co-monomers, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. SNPs binding capacity of hydrogels was evaluated in different concentrations (2, 10, and 20 ppm). In vitro antibacterial activity of SNP-loaded hydrogels was studied against Pseudomonas aeruginosa (P. aeruginosa) isolated from patients' eyes. Then, inhibitory effect of hydrogels in biofilm formation was evaluated in the presence of Staphylococcus epidermidis (S. epidermidis) (DSMZ 3270). Our data indicated that poly(HEMA-co-MAA-co-EGDMA) had superior binding affinity for SNPs in comparison with other hydrogels. All SNP-loaded hydrogels demonstrated excellent antimicrobial effects at all times against P. aeruginosa and S. epidermidis after soaking in 10 and 20 ppm SNP suspensions. Scanning electron microscope (SEM) images revealed excellent inhibitory effect of SNPs against biofilm formation on the surface of the hydrogels. This study indicated the effect of monomer compositions in SNP loading capacity of poly(HEMA) hydrogels and antibacterial efficacy of SNP-loaded hydrogels against P. aeruginosa and S. epidermidis, but further in vivo evaluation is necessary.

  18. Strong expectations cancel locality effects: evidence from Hindi.

    Directory of Open Access Journals (Sweden)

    Samar Husain

    Full Text Available Expectation-driven facilitation (Hale, 2001; Levy, 2008 and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005 are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech "verb" is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge.

  19. Antibacterial Effect of Granati fructus Cortex Extract on Streptococcus mutans In Vitro

    Directory of Open Access Journals (Sweden)

    Cut R. Alfath

    2013-07-01

    Full Text Available 72 1024x768 The rind of pomegranate fruit (Granati fructus cortex composed of antibacterial compounds such as alkaloid, flavonoid and tannin. Objective: To evaluate the bacterial effect of Granati fructus cortex extract against Streptococcus mutans. Methods: The study was laboratory experimental. The inhibition test was performed by agar diffusion method on MHA medium. Results: It showed the bacterial property of Granati fructus cortex on various concentration. The highest extract concentration of 30% extract has the largest of inhibition zones (15.4mm. The results showed a difference in the size of inhibition zones related to different extract concentrations. Conclusion: This study confirmed the antibacterial effect of Granati fructus cortex on the growth of Streptococcus mutans.DOI: 10.14693/jdi.v20i1.126

  20. Biocompatibility and antibacterial effect of silver doped 3D-glass-ceramic scaffolds for bone grafting.

    Science.gov (United States)

    Balagna, Cristina; Vitale-Brovarone, Chiara; Miola, Marta; Verné, Enrica; Canuto, Rosa Angela; Saracino, Silvia; Muzio, Giuliana; Fucale, Giacomo; Maina, Giovanni

    2011-02-01

    A 3D-glass-ceramic scaffold for bone tissue engineering with an interconnected macroporous network of pores was doped with silver ions in order to confer antibacterial properties. For this purpose, silver ions were selectively added to the scaffold surfaces through ion-exchange using an aqueous silver nitrate solution. The silver-doped scaffolds were characterized by means of leaching, in vitro antibacterial, and citotoxicity tests. In particular, the silver effect was examined through a broth dilution test in order to evaluate the proliferation of bacteria by counting the colonies forming units. Moreover, cytotoxicity tests were carried out to understand the effect of silver-containing scaffolds on cell adhesion, proliferation, and vitality. For all tests a comparison between silver-doped scaffold and silver-doped scaffold dry sterilized was performed.

  1. Effect of Argon Plasma Treatment Variables on Wettability and Antibacterial Properties of Polyester Fabrics

    Science.gov (United States)

    Senthilkumar, Pandurangan; Karthik, Thangavelu

    2016-04-01

    In this research work, the effect of argon plasma treatment variables on the comfort and antibacterial properties of polyester fabric has been investigated. The SEM micrographs and FTIR analysis confirms the modification of fabric surface. The Box-Behnken design was used for the optimization of plasma process variables and to evaluate the effects and interactions of the process variables, i.e. operating power, treatment time and distance between the electrodes on the characteristics of polyester fabrics. The optimum conditions of operating power 600 W, treatment time 30 s, and the distance between the electrodes of 2.8 mm was arrived using numerical prediction tool in Design-Expert software. The plasma treated polyester fabrics showed better fabric characteristics particularly in terms of water vapour permeability, wickability and antibacterial activity compared to untreated fabrics, which confirms that the modified structure of polyester fabric.

  2. Susceptibility of Porphyromonas gingivalis and Streptococcus mutans to Antibacterial Effect from Mammea americana

    Directory of Open Access Journals (Sweden)

    Alejandra Herrera Herrera

    2014-01-01

    Full Text Available The development of periodontal disease and dental caries is influenced by several factors, such as microorganisms of bacterial biofilm or commensal bacteria in the mouth. These microorganisms trigger inflammatory and immune responses in the host. Currently, medicinal plants are treatment options for these oral diseases. Mammea americana extracts have reported antimicrobial effects against several microorganisms. Nevertheless, this effect is unknown against oral bacteria. Therefore, the aim of this study was to evaluate the antibacterial effect of M. americana extract against Porphyromonas gingivalis and Streptococcus mutans. For this, an experimental study was conducted. Ethanolic extract was obtained from seeds of M. americana (one oil phase and one ethanolic phase. The strains of Porphyromonas gingivalis ATCC 33277 and Streptococcus mutans ATCC 25175 were exposed to this extract to evaluate its antibacterial effect. Antibacterial activity was observed with the two phases of M. americana extract on P. gingivalis and S. mutans with lower MICs (minimum inhibitory concentration. Also, bactericidal and bacteriostatic activity was detected against S. mutans, depending on the concentration of the extract, while on M. americana extract presented only bacteriostatic activity against P. gingivalis. These findings provide important and promising information allowing for further exploration in the future.

  3. Antibacterial effect of four endodontic cements against Enterococcus faecalis ATCC 29212. An in vitro study.

    Directory of Open Access Journals (Sweden)

    Marcos J. Carruitero

    2017-12-01

    Full Text Available Objective: To compare the in vitro antibacterial effect of the root canal cements Endobalsam®, Top Seal®, Apexit® and Endofill® against Enterococcus faecalis ATCC 29212. Materials and method: Eighty-five applications of cements on Enterococcus faecalis, cultured in vitro on solid media in Petri dishes, were analyzed. Five groups were evaluated: four for each cement, and the fifth for the positive control (amoxicillin. The antibacterial effect was measured by the diameters of the bacterial inhibition halos at 24 hours, 48 hours, and seven days. Student´s t-test, ANOVA and the Tukey test were used for the statistical analysis. Results: No statistically significant differences were found at 24 hours (p>0.05; at 48 hours and seven days, Endofill® and Apexit® had the greatest effect (p0.05. Conclusion: Enterococcus faecalis ATCC 29212 was susceptible to all cements. Endofill® had greater in vitro antibacterial effect than Apexit®, Top Seal® and Endobalsam®.

  4. Antibacterial properties of tualang honey and its effect in burn wound management: a comparative study

    Directory of Open Access Journals (Sweden)

    Nasir Nur-Azida

    2010-06-01

    Full Text Available Abstract Background The use of honey as a natural product of Apis spp. for burn treatment has been widely applied for centuries. Tualang honey has been reported to have antibacterial properties against various microorganisms, including those from burn-related diagnoses, and is cheaper and easier to be absorbed by Aquacel dressing. The aim of this study is to evaluate the potential antibacterial properties of tualang honey dressing and to determine its effectiveness as a partial thickness burn wound dressing. Methods In order to quantitate the bioburden of the swabs, pour plates were performed to obtain the colony count (CFU/ml. Swabs obtained from burn wounds were streaked on blood agar and MacConkey agar for bacterial isolation and identification. Later, antibacterial activity of Aquacel-tualang honey, Aquacel-Manuka honey, Aquacel-Ag and Aquacel- plain dressings against bacteria isolated from patients were tested (in-vitro to see the effectiveness of those dressings by zone of inhibition assays. Results Seven organisms were isolated. Four types of Gram-negative bacteria, namely Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas spp. and Acinetobacter spp., and three Gram-positive bacteria, namely Staphylococcus aureus, coagulase-negative Staphylococcus aureus (CONS and Streptococcus spp., were isolated. Total bacterial count decreased on day 6 and onwards. In the in-vitro antibacterial study, Aquacel-Ag and Aquacel-Manuka honey dressings gave better zone of inhibition for Gram positive bacteria compared to Aquacel-Tualang honey dressing. However, comparable results were obtained against Gram negative bacteria tested with Aquacel-Manuka honey and Aquacel-Tualang honey dressing. Conclusions Tualang honey has a bactericidal as well as bacteriostatic effect. It is useful as a dressing, as it is easier to apply and is less sticky compared to Manuka honey. However, for Gram positive bacteria, tualang honey is not as effective as usual care

  5. Photocatalytic antibacterial effects are maintained on resin-based TiO2 nanocomposites after cessation of UV irradiation.

    Science.gov (United States)

    Cai, Yanling; Strømme, Maria; Welch, Ken

    2013-01-01

    Photocatalysis induced by TiO2 and UV light constitutes a decontamination and antibacterial strategy utilized in many applications including self-cleaning environmental surfaces, water and air treatment. The present work reveals that antibacterial effects induced by photocatalysis can be maintained even after the cessation of UV irradiation. We show that resin-based composites containing 20% TiO2 nanoparticles continue to provide a pronounced antibacterial effect against the pathogens Escherichia coli, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus mutans and Enterococcus faecalis for up to two hours post UV. For biomaterials or implant coatings, where direct UV illumination is not feasible, a prolonged antibacterial effect after the cessation of the illumination would offer new unexplored treatment possibilities.

  6. Photocatalytic antibacterial effects are maintained on resin-based TiO2 nanocomposites after cessation of UV irradiation.

    Directory of Open Access Journals (Sweden)

    Yanling Cai

    Full Text Available Photocatalysis induced by TiO2 and UV light constitutes a decontamination and antibacterial strategy utilized in many applications including self-cleaning environmental surfaces, water and air treatment. The present work reveals that antibacterial effects induced by photocatalysis can be maintained even after the cessation of UV irradiation. We show that resin-based composites containing 20% TiO2 nanoparticles continue to provide a pronounced antibacterial effect against the pathogens Escherichia coli, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus mutans and Enterococcus faecalis for up to two hours post UV. For biomaterials or implant coatings, where direct UV illumination is not feasible, a prolonged antibacterial effect after the cessation of the illumination would offer new unexplored treatment possibilities.

  7. the antibacterial effect of two medicinal plants inula viscosa

    African Journals Online (AJOL)

    Side Larbi K, Meddah B, Tir Touil Meddah A and Sonnet P

    2016-05-01

    May 1, 2016 ... resistant strains. The increase of this phenomenon threatens public health on a global scale as ... The aerial parts of plants (100 g with 1l of distilled water) were hydrodistillated for 3 h. using a .... Essential oils from the aerial parts of the two plants have a liquid appearance, yellow color with strong and ...

  8. Antibacterial Effects of Citrus aurantium on Bacteria Isolated from Urinary Tract Infection

    Directory of Open Access Journals (Sweden)

    Masoud Dadashi

    2015-10-01

    Full Text Available Background :  Emerging antibacterial resistance rates and beta-lactamase producing bacteria recovered from UTI is an increasing problem in different regions, limiting therapeutic options. Therefore, this survey consider to use the extract and essence of the citrus aurantium (which have a so many rate of planting in Iran and also survey on extract on bacteria whose cause urinary tract infections, and compare this with common antibiotics. Methods and Materials: This study was experimental design.We have been isolate the E.coli,Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae and Enterococcus faecalis from UTI and then determine of antibacterial effect of Citrus aurantium against this bacteria with subculture and put the exact diagnosis on them. Antibacterial effects of the herb extract by well diffusion assay and  nalidixic acid and Co-trimoxazol were evaluated by method of agar disc diffusion. Results:Enterococcus faecalis had 100% sensitivity against of extract,essence and Co-trimoxazole , and 80% against nalidixic acid . E.coli had 100% sensitivity against Co-trimoxazol, nalidixic acid and it was totally resistance to extract and essence.Klebsiella Pneumonie had 80% to Co-trimoxazol, 75% to nalidixic acid and resistance against extract and essence.Streptococcus agalactiae was 100% sensitivity to essence and Co-trimoxazol and 90% against nalidixic acid and shown 80% sensitivity against extract.Staphylococcus aureus MRSA shown 100% sensitivity against Co-trimoxazol and 70% sensitivity against essence, extract and nalidixic acid. Conclusion: Detection of antibiotic resistance among isolates is important in prevention and control of infections. In this study, it was shown that extracts of citrus aurantium have high antibacterial effects on gram positive bacteria compare to gram negative bacteria.

  9. Chemical composition, anthelmintic, antibacterial and antioxidant effects of Thymus bovei essential oil.

    Science.gov (United States)

    Jaradat, Nidal; Adwan, Lina; K'aibni, Shadi; Shraim, Naser; Zaid, Abdel Naser

    2016-10-26

    It has been recently recognized that oxidative stress, helminth and microbial infections are the cause of much illness found in the underdeveloped, developing and developed countries. The present study was undertaken to identify the chemical composition, and to assess anthelmintic, antimicrobial and antioxidant effects of Thymus bovei essential oil. The chemical composition of the essential oil was analyzed using gas chromatography mass spectrometry (GC-MS). Antimicrobial activity was tested against the selected strains from American Type Culture Collection (ATCC) and clinical isolates such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Methicillin Resistant Staphylococcus aureus, Candida albicans using MIC assay. The anthelmintic assay was carried out on adult earthworm (Pheretima posthuma), while antioxidant activity was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. Trans-geraniol (35.38 %), α-citral (20.37 %) and β-citral (14.76 %) were the major compounds comprising 70.51 % of the essential oil. Our results showed that T. bovei essential oil exhibited strong anthelmintic activity, even higher than piperazine citrate, the used reference standard, with potential antioxidant activity almost equal to the Trolox standard. Furthermore, T. bovei essential oil had powerful antibacterial and antifungal activities against the studied pathogens. Essential oil of T. bovei exerted excellent antioxidant, antimicrobial, and anthelmintic activities. Moreover, this study found that T. bovei volatile oil contains active substances that could potentially be used as natural preservatives in food and pharmaceutical industries, these substances could also be employed for developing new anthelmintic, antimicrobial and antioxidant agents.

  10. Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae

    Directory of Open Access Journals (Sweden)

    Mojtaba Davoudi

    2012-01-01

    Full Text Available Aims: Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae was investigated in this study. Materials and Methods: The efficacy of 30 ppb silver in 0.3% hydrogen peroxide solution for inactivation of selected Enterobacteriaceae, including Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae was assessed for 72 hours in a designated nutrient broth medium and steel surface. The bactericidal growth ability was determined for each bacterium genus by the conventional colony count method and turbidimetry via an optical density (OD assay at 450 nm in a time interval of 24 hours. Results: Suspensions of K.pneumoniae, and P.mirabilis showed a significant OD reduction at three 24-hour intervals (CI = 0.95; P < 0.05, for both, along with blocked growth in a designated broth medium during 24 to 48 hours of exposure. The disinfectant was also significantly efficient for inactivating of the mentioned bacteria on steel surfaces after a 15-minute time exposure (CI = 0.95; P < 0.05. For E.coli, the OD decreased slightly during the initial exposure time, but increased after 24 hours. Viable E.coli cells were proved by colonies grown on the plate. A qualitative surface decontamination test showed that three pathogenic bacteria were inactivated significantly after disinfectant exposure (CI = 0.95, P < 0.05. Conclusions: In conclusion, a combination of hydrogen peroxide and silver ions was proposed as a strong disinfecting agent both in suspensions and on the surfaces against these three important human pathogens.

  11. Antibacterial Effects of Cinnamon: From Farm to Food, Cosmetic and Pharmaceutical Industries

    Science.gov (United States)

    Nabavi, Seyed Fazel; Di Lorenzo, Arianna; Izadi, Morteza; Sobarzo-Sánchez, Eduardo; Daglia, Maria; Nabavi, Seyed Mohammad

    2015-01-01

    Herbs and spices have been used since ancient times, because of their antimicrobial properties increasing the safety and shelf life of food products by acting against foodborne pathogens and spoilage bacteria. Plants have historically been used in traditional medicine as sources of natural antimicrobial substances for the treatment of infectious disease. Therefore, much attention has been paid to medicinal plants as a source of alternative antimicrobial strategies. Moreover, due to the growing demand for preservative-free cosmetics, herbal extracts with antimicrobial activity have recently been used in the cosmetic industry to reduce the risk of allergies connected to the presence of methylparabens. Some species belonging to the genus Cinnamomum, commonly used as spices, contain many antibacterial compounds. This paper reviews the literature published over the last five years regarding the antibacterial effects of cinnamon. In addition, a brief summary of the history, traditional uses, phytochemical constituents, and clinical impact of cinnamon is provided. PMID:26378575

  12. Oil Essential Mouthwashes Antibacterial Activity against Aggregatibacter actinomycetemcomitans: A Comparison between Antibiofilm and Antiplanktonic Effects

    Directory of Open Access Journals (Sweden)

    Matteo Erriu

    2013-01-01

    Full Text Available The aim of this work is to determine the antibacterial activity of three marketed mouthwashes on suspended and sessile states of Aggregatibacter actinomycetemcomitans. The efficacy of two commonly used products in clinical practice, containing essential oils as active ingredients (menthol, thymol, methyl salicylate, and eucalyptol in association with or without alcohol, has been evaluated in comparison with a chlorhexidine-based mouthwash. The microtiter plate assay, in order to obtain a spectrophotometric measurement of bacterial responses at growing dilutions of each antiseptic, was used for the study. The analysis revealed that a good antibacterial activity is reached when the abovementioned mouthwashes were used at concentration over a 1/24 dilution and after an exposure time of 30 seconds at least. In conclusion, the alcoholic mouthwash appears to have a better biofilm inhibition than its antiplanktonic activity while the nonalcoholic product demonstrates an opposite effect with a better antiplanktonic behavior.

  13. Oil Essential Mouthwashes Antibacterial Activity against Aggregatibacter actinomycetemcomitans: A Comparison between Antibiofilm and Antiplanktonic Effects.

    Science.gov (United States)

    Erriu, Matteo; Pili, Francesca Maria Giovanna; Tuveri, Enrica; Pigliacampo, Daniela; Scano, Alessandra; Montaldo, Caterina; Piras, Vincenzo; Denotti, Gloria; Pilloni, Andrea; Garau, Valentino; Orrù, Germano

    2013-01-01

    The aim of this work is to determine the antibacterial activity of three marketed mouthwashes on suspended and sessile states of Aggregatibacter actinomycetemcomitans. The efficacy of two commonly used products in clinical practice, containing essential oils as active ingredients (menthol, thymol, methyl salicylate, and eucalyptol) in association with or without alcohol, has been evaluated in comparison with a chlorhexidine-based mouthwash. The microtiter plate assay, in order to obtain a spectrophotometric measurement of bacterial responses at growing dilutions of each antiseptic, was used for the study. The analysis revealed that a good antibacterial activity is reached when the abovementioned mouthwashes were used at concentration over a 1/24 dilution and after an exposure time of 30 seconds at least. In conclusion, the alcoholic mouthwash appears to have a better biofilm inhibition than its antiplanktonic activity while the nonalcoholic product demonstrates an opposite effect with a better antiplanktonic behavior.

  14. Antibacterial Effects of Cinnamon: From Farm to Food, Cosmetic and Pharmaceutical Industries

    Directory of Open Access Journals (Sweden)

    Seyed Fazel Nabavi

    2015-09-01

    Full Text Available Herbs and spices have been used since ancient times, because of their antimicrobial properties increasing the safety and shelf life of food products by acting against foodborne pathogens and spoilage bacteria. Plants have historically been used in traditional medicine as sources of natural antimicrobial substances for the treatment of infectious disease. Therefore, much attention has been paid to medicinal plants as a source of alternative antimicrobial strategies. Moreover, due to the growing demand for preservative-free cosmetics, herbal extracts with antimicrobial activity have recently been used in the cosmetic industry to reduce the risk of allergies connected to the presence of methylparabens. Some species belonging to the genus Cinnamomum, commonly used as spices, contain many antibacterial compounds. This paper reviews the literature published over the last five years regarding the antibacterial effects of cinnamon. In addition, a brief summary of the history, traditional uses, phytochemical constituents, and clinical impact of cinnamon is provided.

  15. Antibacterial Effects of Cinnamon: From Farm to Food, Cosmetic and Pharmaceutical Industries.

    Science.gov (United States)

    Nabavi, Seyed Fazel; Di Lorenzo, Arianna; Izadi, Morteza; Sobarzo-Sánchez, Eduardo; Daglia, Maria; Nabavi, Seyed Mohammad

    2015-09-11

    Herbs and spices have been used since ancient times, because of their antimicrobial properties increasing the safety and shelf life of food products by acting against foodborne pathogens and spoilage bacteria. Plants have historically been used in traditional medicine as sources of natural antimicrobial substances for the treatment of infectious disease. Therefore, much attention has been paid to medicinal plants as a source of alternative antimicrobial strategies. Moreover, due to the growing demand for preservative-free cosmetics, herbal extracts with antimicrobial activity have recently been used in the cosmetic industry to reduce the risk of allergies connected to the presence of methylparabens. Some species belonging to the genus Cinnamomum, commonly used as spices, contain many antibacterial compounds. This paper reviews the literature published over the last five years regarding the antibacterial effects of cinnamon. In addition, a brief summary of the history, traditional uses, phytochemical constituents, and clinical impact of cinnamon is provided.

  16. Antibacterial effect (in vitro) of Moringa oleifera and Annona muricata against Gram positive and Gram negative bacteria.

    Science.gov (United States)

    Viera, Gustavo Hitzschky Fernandes; Mourão, Jozeanne Alves; Angelo, Angela Maria; Costa, Renata Albuquerque; Vieira, Regine Helena Silva dos Fernandes

    2010-01-01

    Antibacterial effects of aqueous and ethanolic extracts of seeds of moringa (Moringa oleifera) and pods of soursop (Annona muricata) in the concentration of 1:5 and 1:10 in volumes 50, 100, 150 and 200 microL were examined against Staphylococcus aureus, Vibrio cholerae, Escherichia coli (isolated from the organism and the aquatic environment) and Salmonella Enteritidis. Antibacterial activity (inhibition halo > 13 mm) against S. aureus, V. cholerae and E. coli isolated from the whiteleg shrimp, Litopenaeus vannmaei, was detected in aqueous and ethanolic extracts of moringa. E. coli isolated from tilapiafish, Oreochromis niloticus, was sensitive to the ethanolic extract of moringa. The aqueous extracts of soursop showed an antibacterial effect against S. aureus and V. cholerae, but the antibacterial activity by the ethanol extracts of this plant was not demonstrated.

  17. Antibacterial effects of cinnamon (Cinnamomum zeylanicum) bark essential oil on Porphyromonas gingivalis.

    Science.gov (United States)

    Wang, Yue; Zhang, Yi; Shi, Yan-Qin; Pan, Xian-Hua; Lu, Yan-Hua; Cao, Ping

    2018-01-09

    The objective of this study was to investigate the antibacterial effects of cinnamon (Cinnamomum zeylanicum) bark essential oil (CBEO) and its principal constituent cinnamaldehyde against Porphyromonas gingivalis and to elucidate the antibacterial mechanism. GC-MS analysis showed that cinnamaldehyde was the major constituent in CBEO (57.97%). The minimum inhibition concentrations (MICs) of CBEO and cinnamaldehyde were 6.25 μg/mL and 2.5 μM for P. gingivalis, respectively. Nucleic acid and protein leakage was observed with increasing concentrations of CBEO and cinnamaldehyde. Additionally, propidium iodide uptake assays revealed CBEO and cinnamaldehyde at 1 × MIC impaired P. gingivalis membrane integrity by enhancing cell permeability. Morphological changes in P. gingivalis cells were observed by scanning electron microscopy, which indicated cell membrane destruction. To further determine the anti-biofilm effect, relative biofilm formation and established biofilms were examined, which demonstrated that both CBEO and cinnamaldehyde at sub-MIC levels inhibited P. gingivalis biofilm formation by 74.5% and 67.3% separately, but only CBEO slightly decreased established biofilms by 33.5% at 4 × MIC. These results suggest the potential of CBEO as a natural antimicrobial agent against periodontal disease. Furthermore, cinnamaldehyde was confirmed to be the antibacterial substance of CBEO with inhibitory action against P. gingivalis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Osteogenic response and osteoprotective effects in vivo of a nanostructured titanium surface with antibacterial properties.

    Science.gov (United States)

    Ravanetti, F; Chiesa, R; Ossiprandi, M C; Gazza, F; Farina, V; Martini, F M; Di Lecce, R; Gnudi, G; Della Valle, C; Gavini, J; Cacchioli, A

    2016-03-01

    In implantology, as an alternative approach to the use of antibiotics, direct surface modifications of the implant addressed to inhibit bacterial adhesion and to limit bacterial proliferation are a promising tactic. The present study evaluates in an in vivo normal model the osteogenic response and the osteointegration of an anodic spark deposition nanostructured titanium surface doped with gallium (ASD + Ga) in comparison with two other surface treatments of titanium: an anodic spark deposition treatment without gallium (ASD) and an acid etching treatment (CTR). Moreover the study assesses the osteoprotective potential and the antibacterial effect of the previously mentioned surface treatments in an experimentally-induced peri-implantitis model. The obtained data points out a more rapid primary fixation in ASD and ASD + Ga implants, compared with CTR surface. Regarding the antibacterial properties, the ASD + Ga surface shows osteoprotective action on bone peri-implant tissue in vivo as well as an antibacterial effect within the first considered time point.

  19. Antibacterial Effects of Cissus welwitschii and Triumfetta welwitschii Extracts against Escherichia coli and Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Batanai Moyo

    2015-01-01

    Full Text Available Antibiotic resistance has increased sharply, while the pace for the development of new antimicrobials has slowed down. Plants provide an alternative source for new drugs. This study aimed to screen extracts from Cissus welwitschii and Triumfetta welwitschii for antibacterial activity against Escherichia coli and Bacillus cereus. The tests conducted included a susceptibility determination test, analysis of the effect of T. welwitschii on cell wall integrity, and transport across the membrane. It was found that the T. welwitschii methanol extracts were more effective than the water extracts and had the lowest minimum inhibitory concentration and minimum bactericidal concentration at 0.125 mg/mL and 0.5 mg/mL, respectively, against E. coli and B. cereus. The C. welwitschii extract caused the most drug accumulation in E. coli. In B. cereus, no significant drug accumulation was observed. Nucleic acid leakage in B. cereus and E. coli and protein leakage in E. coli were observed after exposure to the T. welwitschii extract. The extracts from T. welwitschii had greater antibacterial activity than the extracts from C. welwitschii. T. welwitschii may be a potential source of lead compounds for that could be developed into antibacterial agents.

  20. Strong Gravity Effects of Rotating Black Holes: Quasiperiodic Oscillations

    OpenAIRE

    Aliev, Alikram N.; Esmer, Göksel Daylan; Talazan, Pamir

    2012-01-01

    We explore strong gravity effects of the geodesic motion in the spacetime of rotating black holes in general relativity and braneworld gravity. We focus on the description of the motion in terms of three fundamental frequencies: The orbital frequency, the radial and vertical epicyclic frequencies. For a Kerr black hole, we perform a detailed numerical analysis of these frequencies at the innermost stable circular orbits and beyond them as well as at the characteristic stable orbits, at which ...

  1. New results on strong-interaction effects in antiprotonic hydrogen

    CERN Document Server

    Gotta, D; Augsburger, M A; Borchert, G L; Castelli, C M; Chatellard, D; El-Khoury, P; Egger, J P; Gorke, H; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Nelms, N; Rashid, K; Schult, O W B; Siems, T; Simons, L M

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the low-energy antiproton ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using charge-coupled devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (33 refs).

  2. New results on strong-interaction effects in antiprotonic hydrogen

    International Nuclear Information System (INIS)

    Anagnostopoulos, D. F.; Augsburger, M.; Borchert, G.; Castelli, C.; Chatellard, D.; El-Khoury, P.; Egger, J.-P.; Gorke, H.; Gotta, D.; Hauser, P.; Indelicato, P.; Kirch, K.; Lenz, S.; Nelms, N.; Rashid, K.; Schult, O. W. B.; Siems, Th.; Simons, L. M.

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the Low-Energy Antiproton Ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using Charge-Coupled Devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction

  3. Experimental Study on the comparison of antibacterial and antioxidant effects between the Bee Venom and Sweet Bee Venom

    OpenAIRE

    Joong chul An; Ki Rok Kwon; Eun Hee Lee; Bae Chun Cha

    2006-01-01

    Objectives : This study was conducted to compare antibacterial activities and free radical scavenging activity between the Bee Venom and Sweet Bee Venom in which the allergy-causing enzyme is removed. Methods : To evaluate antibacterial activities of the test samples, gram negative E. coli and gram positive St. aureus were compared using the paper disc method. For comparison of the antioxidant effects, DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging assay and Thiobarbituric Ac...

  4. Enhanced antibacterial activity of silver-decorated sandwich-like mesoporous silica/reduced graphene oxide nanosheets through photothermal effect

    Science.gov (United States)

    Liu, Rong; Wang, Xuandong; Ye, Jun; Xue, Ximei; Zhang, Fangrong; Zhang, Huicong; Hou, Xuemei; Liu, Xiaolong; Zhang, Yun

    2018-03-01

    Drug resistance of bacteria has become a global health problem, as it makes conventional antibiotics less efficient. It is urgently needed to explore novel antibacterial materials and develop effective treatment strategies to overcome the drug resistance of antibiotics. Herein, we successfully synthesized silver decorated sandwich-like mesoporous silica/reduced graphene oxide nanosheets (rGO/MSN/Ag) as a novel antibacterial material through facile method. The rGO and Ag nanoparticles can be reduced in the reaction system without adding any other reductants. In addition, the rGO/MSN/Ag showed higher photothermal conversion capacity due to the modification of silver nanoparticles and exhibited excellent antibacterial activities against Pseudomonas putida, Escherichia coli and Rhodococcus at relatively low dosages, which was confirmed by the minimum inhibitory concentration (MIC) test. Meanwhile, the E. coli with a high concentration was selected for exposure using an 808 nm laser, and the antibacterial effect was obviously enhanced by the near-infrared irradiation induced photothermal effect. Moreover, the hepatocyte LO2 were used for the cytotoxicity evaluation, and the rGO/MSN/Ag showed low toxicity and were without detectable cytotoxicity at the antimicrobial dose. As the prepared rGO/MSN/Ag nanosheets have the advantages of low-cost and high antibacterial activity, they might be of promising and useful antibacterial agents for different applications.

  5. Effect of antibacterial agents on the surface hardness of a conventional glass-ionomer cement

    Science.gov (United States)

    TÜZÜNER, Tamer; ULUSU, Tezer

    2012-01-01

    In atraumatic restorative treatment (ART), caries removal with hand excavation instruments is not as efficient as that with rotary burs in eliminating bacteria under the glass ionomer cements (GICs). Thus, different antibacterial agents have been used in recent studies to enhance the antibacterial properties of the GICs, without jeopardizing their basic physical properties. Objective The objective of this study was to evaluate the effect of antibacterial agents on the surface hardness of a conventional GIC (Fuji IX) using Vickers microhardness [Vickers hardness number (VHN)] test. Material and Methods Cetrimide (CT), cetylpyridinium chloride (CPC) and chlorhexidine (CHX) were added to the powder and benzalkonium chloride (BC) was added to the liquid of Fuji IX in concentrations of 1% and 2%, and served as the experimental groups. A control group containing no additive was also prepared. After the completion of setting reaction, VHN measurements were recorded at 1, 7, 15, 30, 60, and 90 days after storage in 37ºC distilled water. A one-way ANOVA was performed followed by a Dunnett t test and Tamhane T2 tests and also repeated measurements ANOVA was used for multiple comparisons in 95% confidence interval. Results VHN results showed significant differences between the control and the experimental groups at all time periods (phardness of set cements. Conclusions Despite the decreased microhardness values in all experimental groups compared to the controls after 7 up to 90 days, incorporating certain antibacterial agents into Fuji IX GIC showed tolerable microhardness alterations within the limitations of this in vitro study. PMID:22437677

  6. Synthesis, characterization and antibacterial effect of new magnetically core–shell nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Allafchian, Alireza, E-mail: Allafchian@cc.iut.ac.ir [Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156 83111 (Iran, Islamic Republic of); Bahramian, Hamid [Department of physics, Isfahan University of Technology, Isfahan 84156 83111 (Iran, Islamic Republic of); Hossein Jalali, Seyed Amir [Institute of Biotechnology and Bioengineering, Isfahan University of Technology, Isfahan 84156 83111 (Iran, Islamic Republic of); Ahmadvand, Hossein [Department of physics, Isfahan University of Technology, Isfahan 84156 83111 (Iran, Islamic Republic of)

    2015-11-15

    A new magnetically responsive three-component nanocomposite consisting of NiFe{sub 2}O{sub 4}, Poly Acrylonitrile Co Maleic Anhydride (PAMA) and nanosilver was synthesized and characterized and then its antibacterial activities were tested. For the preparation of NiFe{sub 2}O{sub 4}@Ag, NiFe{sub 2}O{sub 4} was coated by Ag and for the synthesis of NiFe{sub 2}O{sub 4}@PAMA@Ag, NiFe{sub 2}O{sub 4} was first covered by PAMA and then silver nanoparticles were immobilized on the surface of the PAMA shell. The nanocomposites were studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The antibacterial activity of the synthesized nanocomposite against some gram positive and gram negative bacteria was studied and compared with that of naked NiFe{sub 2}O{sub 4}, NiFe{sub 2}O{sub 4}@Ag and NiFe{sub 2}O{sub 4}@PAMA. The NiFe{sub 2}O{sub 4}@PAMA@Ag had better antibacterial activity and could be readily isolated from the aqueous solution via magnetic decantation, thereby avoiding the contamination of the environment. - Highlights: • A novel NiFe{sub 2}O{sub 4}@PAMA@Ag nanocomposites magnetic composite has been prepared. • This system display potent antimicrobial activity toward some bacterial species. • The antibacterial effect was studied by disk diffusion method. • This composite can be easily removed from solution by magnetic decantation.

  7. Nanostructured molybdenum oxide-based antibacterial paint: effective growth inhibition of various pathogenic bacteria

    Science.gov (United States)

    Krishnamoorthy, Karthikeyan; Premanathan, Mariappan; Veerapandian, Murugan; Kim, Sang Jae

    2014-08-01

    The prevention of bacterial infections in the health care environment is paramount to providing better treatment. Covering a susceptible environment with an antimicrobial coating is a successful way to avoid bacterial growth. Research on the preparation of durable antimicrobial coatings is promising for both fundamental surface care and clinical care applications. Herein, we report a facile, efficient, and scalable preparation of MoO3 paint using a cost-effective ball-milling approach. The MoO3 nanoplates (synthesized by thermal decomposition of ammonium heptamolybdate) are used as a pigment and antibacterial activity moiety in alkyd resin binders and other suitable eco-friendly additives in the preparation of paint. Surface morphology, chemical states, bonding nature, and intermolecular interaction between the MoO3 and the alkyd resin were studied using Raman and x-ray photoelectron spectroscopic analysis. The antibacterial properties of a prepared MoO3 nanoplate against various bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae) was determined using the microdilution method. Bacterial strains exposed to an MoO3 paint coated surface exhibit a significant loss of viability in a time-dependent manner. Fundamental modes of antibacterial activities ascribed from a biocompatible and durable MoO3 nanostructure incorporated into an alkyd resin complex are discussed. The obtained experimental findings suggest the potential utility of prepared MoO3-based paint coating for the prevention of health care associated infections.

  8. Nanostructured molybdenum oxide-based antibacterial paint: effective growth inhibition of various pathogenic bacteria

    International Nuclear Information System (INIS)

    Krishnamoorthy, Karthikeyan; Premanathan, Mariappan; Veerapandian, Murugan; Jae Kim, Sang

    2014-01-01

    The prevention of bacterial infections in the health care environment is paramount to providing better treatment. Covering a susceptible environment with an antimicrobial coating is a successful way to avoid bacterial growth. Research on the preparation of durable antimicrobial coatings is promising for both fundamental surface care and clinical care applications. Herein, we report a facile, efficient, and scalable preparation of MoO 3 paint using a cost-effective ball-milling approach. The MoO 3 nanoplates (synthesized by thermal decomposition of ammonium heptamolybdate) are used as a pigment and antibacterial activity moiety in alkyd resin binders and other suitable eco-friendly additives in the preparation of paint. Surface morphology, chemical states, bonding nature, and intermolecular interaction between the MoO 3 and the alkyd resin were studied using Raman and x-ray photoelectron spectroscopic analysis. The antibacterial properties of a prepared MoO 3 nanoplate against various bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae) was determined using the microdilution method. Bacterial strains exposed to an MoO 3 paint coated surface exhibit a significant loss of viability in a time-dependent manner. Fundamental modes of antibacterial activities ascribed from a biocompatible and durable MoO 3 nanostructure incorporated into an alkyd resin complex are discussed. The obtained experimental findings suggest the potential utility of prepared MoO 3 -based paint coating for the prevention of health care associated infections. (paper)

  9. Comparison of Antibacterial Effect of Fluoride and Chlorhexidine on Two Cariogenic Bacteria: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Poureslami HR

    2014-09-01

    Full Text Available Statement of problem: Dental plaque is the main source for dental caries and there is no proper vaccine that can affect dental plaques. Objectives: Daily use of an efficient anti-plaque product can be very beneficial in plaque control and, thus, prevention of caries. This study aims to evaluate the antibacterial effects of four products of Chlorhexidine and Fluoride on two types of cariogenic bacteria. Materials and Methods: In this in vitro study, the antibacterial effect of Chlorhexidine and Fluoride (gel and solution against Streptococci Sanguis and Sobrinus was evaluated. Chlorhexidine gluconate 1% gel (Corosodyl, France, Chlorhexidine gluconate 2% solution (Consepsis, Ultradent, US, Sodium fluoride 0.2% solution (Oral-B, US and Acidulated Phosphate Fluoride 1.23% gel ( Denti-Care, Canada were used. The disc diffusion method was used for testing bacterial sensitivity. The data were analyzed using paired t-test and Chi-square test. Results: In comparison with the negative control, each of the four gels and solutions showed antibacterial effects but the effects were not statistically significant for fluoride solution (P=0.217. For S. Sobrinus, the mean diameter of inhibition zone around the discs coated with fluoride gel (F g, fluoride solution (F s, Chlorhexidine gel (CHX g and Chlorhexidine solution (CHX s were 19, 9, 21.5 and 27.5mm, respectively. For S. Sanguis, the mean diameter of inhibition zone around the discs coated with F g, F s, CHX g and CHX s were 17, 11, 17 and 25mm, respectively. CHX s had the most effect on both bacteria and F s had the least. CHX g and F g were less effective than CHX s, respectively. Conclusion: The results demonstrated that 2% CHX s and 1.23% F g can be effective on inhibition of the growth of some of cariogenic bacteria. Therefore, these agents can be used in the prevention of Early Childhood Caries.

  10. Molecular composition and antibacterial effect of essential oil of ...

    African Journals Online (AJOL)

    pc

    2013-05-15

    May 15, 2013 ... 21:242-245. Randhawa MA. Al Ghamdi MJ (2002). A review of pharmacotherapeutic effects of Nigella sativa. Pak. J. Med. Res. 41(2):77-83. Rouibi A (2009). Identification and antiseptic effect of the essential oils of two xerophytes species Cassia acutifolia and Cassia Obovata. Master thesis, dpt of Biology, ...

  11. Synergistic Antibacterial Effects of Nanoparticles Encapsulated with Scutellaria baicalensis and Pure Chlorhexidine on Oral Bacterial Biofilms

    Directory of Open Access Journals (Sweden)

    Ken Cham-Fai Leung

    2016-04-01

    Full Text Available Scutellaria baicalensis (SB is a traditional Chinese medicine for treating infectious and inflammatory diseases. Our recent study shows potent antibacterial effects of nanoparticle-encapsulated chlorhexidine (Nano-CHX. Herein, we explored the synergistic effects of the nanoparticle-encapsulated SB (Nano-SB and Nano-CHX on oral bacterial biofilms. Loading efficiency of Nano-SB was determined by thermogravimetric analysis, and its releasing profile was assessed by high-performance liquid chromatographyusing baicalin (a flavonoid compound of SB as the marker. The mucosal diffusion assay on Nano-SB was undertaken in a porcine model. The antibacterial effects of the mixed nanoparticles (Nano-MIX of Nano-SB and Nano-CHX at 9:1 (w/w ratio were analyzed in both planktonic and biofilm modes of representative oral bacteria. The Nano-MIX was effective on the mono-species biofilms of Streptococcus (S. mutans, S. sobrinus, Fusobacterium (F. nucleatum, and Aggregatibacter (A. actinomycetemcomitans (MIC 50 μg/mL at 24 h, and exhibited an enhanced effect against the multi-species biofilms such as S. mutans, F. nucleatum, A. actinomycetemcomitans, and Porphyromonas (P. gingivalis (MIC 12.5 μg/mL at 24 h that was supported by the findings of both scanning electron microscopy (SEM and confocal scanning laser microscopy (CLSM. This study shows enhanced synergistic antibacterial effects of the Nano-MIX on common oral bacterial biofilms, which could be potentially developed as a novel antimicrobial agent for clinical oral/periodontal care.

  12. Superconducting proximity effect in the strong-coupling limit

    International Nuclear Information System (INIS)

    Wilvert, W.

    1975-01-01

    A generalization of the theory of the superconducting proximity effect is presented which takes into account strong-coupling in the superconductors. The results are found to agree with a model of weak-coupled superconductors with differing Debye frequencies which are in proximity. It is found that logarithmic averaging of phonon frequencies is an improvement on the original McMillan theory (1968). Comparison of the theory with data on thin films and on eutectic alloys is found to give good agreement. 19 references

  13. Strong dynamical effects during stick-slip adhesive peeling.

    Science.gov (United States)

    Dalbe, Marie-Julie; Santucci, Stéphane; Cortet, Pierre-Philippe; Vanel, Loïc

    2014-01-07

    We consider the classical problem of the stick-slip dynamics observed when peeling a roller adhesive tape at a constant velocity. From fast imaging recordings, we extract the dependence of the stick and slip phase durations on the imposed peeling velocity and peeled ribbon length. Predictions of Maugis and Barquins [in Adhesion 12, edited by K. W. Allen, Elsevier ASP, London, 1988, pp. 205-222] based on a quasistatic assumption succeed to describe quantitatively our measurements of the stick phase duration. Such a model however fails to predict the full stick-slip cycle duration, revealing strong dynamical effects during the slip phase.

  14. Chemical Composition and Antibacterial Effect of Medicinal Plants against Some Food-Borne Pathogen

    Directory of Open Access Journals (Sweden)

    Hassan Habibi

    2017-05-01

    Conclusion: Antibacterial efficacy shown by these plants provides a scientific basis and thus validates their use as medicinal remedies. Isolation and purification of different phytochemicals may further yield significant antibacterial agents.

  15. Antibacterial Effect of Hydroalcoholic Extract of Punica granatum Linn. Petal on Common Oral Microorganisms

    Science.gov (United States)

    Hajifattahi, Farnaz; Moravej-Salehi, Elham; Taheri, Maryam; Mahboubi, Arash; Kamalinejad, Mohammad

    2016-01-01

    Objectives. This study aimed to assess the effect of hydroalcoholic extract of Punica granatum Linn. (P. granatum) petal on Streptococcus sanguinis, Streptococcus mutans, Streptococcus salivarius, Streptococcus sobrinus, and Enterococcus faecalis. Materials and Methods. In this in vitro study, P. granatum extract was prepared using powdered petals and water-ethanol solvent. Antibacterial effect of the extract, chlorhexidine (CHX), and ampicillin was evaluated on brain heart infusion agar (BHIA) using the cup-plate method. By assessing the diameter of the growth inhibition zone, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract were determined for the above-mentioned bacteria. Results. Hydroalcoholic extract of P. granatum petal had inhibitory effects on the proliferation of all five bacterial strains with maximum effect on S. mutans with MIC and MBC of 3.9 mg/mL. The largest growth inhibition zone diameter belonged to S. sanguinis and the smallest to E. faecalis. Ampicillin and CHX had the greatest inhibitory effect on S. sanguinis. Conclusions. Hydroalcoholic extract of P. granatum had a significant antibacterial effect on common oral bacterial pathogens with maximum effect on S. mutans, which is the main microorganism responsible for dental plaque and caries. PMID:26884763

  16. Antibacterial Effect of Hydroalcoholic Extract of Punica granatum Linn. Petal on Common Oral Microorganisms.

    Science.gov (United States)

    Hajifattahi, Farnaz; Moravej-Salehi, Elham; Taheri, Maryam; Mahboubi, Arash; Kamalinejad, Mohammad

    2016-01-01

    Objectives. This study aimed to assess the effect of hydroalcoholic extract of Punica granatum Linn. (P. granatum) petal on Streptococcus sanguinis, Streptococcus mutans, Streptococcus salivarius, Streptococcus sobrinus, and Enterococcus faecalis. Materials and Methods. In this in vitro study, P. granatum extract was prepared using powdered petals and water-ethanol solvent. Antibacterial effect of the extract, chlorhexidine (CHX), and ampicillin was evaluated on brain heart infusion agar (BHIA) using the cup-plate method. By assessing the diameter of the growth inhibition zone, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract were determined for the above-mentioned bacteria. Results. Hydroalcoholic extract of P. granatum petal had inhibitory effects on the proliferation of all five bacterial strains with maximum effect on S. mutans with MIC and MBC of 3.9 mg/mL. The largest growth inhibition zone diameter belonged to S. sanguinis and the smallest to E. faecalis. Ampicillin and CHX had the greatest inhibitory effect on S. sanguinis. Conclusions. Hydroalcoholic extract of P. granatum had a significant antibacterial effect on common oral bacterial pathogens with maximum effect on S. mutans, which is the main microorganism responsible for dental plaque and caries.

  17. Antibacterial effect of Ocimum gratissimum against bacteria from ...

    African Journals Online (AJOL)

    The upsurge in the prevalence of side effects of many synthetic antimicrobial agents and incidence of multidrug resistant bacteria has spurred scientists on the research for plant based antimicrobial of therapeutic potentials. Ocimum gratissimum presents such potential of high medicinal value. This plant is used in Nigeria ...

  18. Antifungal and antibacterial effects of some acrocarpic mosses ...

    African Journals Online (AJOL)

    of the number of microorganism affected. Tortella tortuosa (Hedw.) Limpr. only has effect on Candida albicans ATCC 16231 strain. All the results were compared with standard antibiotic discs, ketoconazole (50 ìg), ampicillin (10 ìg), eritromycin (15 ìg) and vancomycin (30 ìg). Key words: Moss, acrocarpous, antimicrobial ...

  19. Preparation, characterization and antibacterial effects of eco-friendly ...

    African Journals Online (AJOL)

    Purpose: To synthesize and characterize eco-friendly gold nanorods (Au-NRs) and to assess their effects against two bacterial strains. Methods: Synthesis of eco-friendly gold nanorods was done from an aqueous solution of chloroauric acid and cetyltrimethylammonium bromide by mixing Olea europaea fruit and Acacia ...

  20. Deodorant effects of a sage extract stick: Antibacterial activity and sensory evaluation of axillary deodorancy

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Shahtalebi

    2013-01-01

    Full Text Available Background: Deodorant products prevent the growth and activity of the degrading apocrine gland bacteria living in the armpit. Common antibacterial agents in the market like triclosan and aluminum salts, in spite of their suitable antibacterial effects, increase the risk of Alzheimer′s disease, breast and prostate cancers or induce contact dermatitis. Therefore, plant extracts possessing antibacterial effects are of interest. The aim of the present study was to verify the in vitro antimicrobial effects of different sage extracts against two major bacteria responsible for axillary odor, and to evaluate the deodorant effect of a silicon-based stick containing sage extracts in different densities in humans. Materials and Methods: Different fractions of methanolic extract of Salvia officinalis (sage were evaluated on a culture of armpit skin surface of volunteers through agar microdilution antimicrobial assay. Then, randomized, double-blind placebo-controlled clinical trial with the best antibacterial fraction was conducted on 45 female healthy volunteers. Participants were treated with a single dose in four groups, each containing 15 individuals: Group 1 (200 μg/mL, 2 (400 μg/mL, 3 (600 μg/mL of dichloromethane sage extract, and placebo (without extract. A standard sensory evaluation method for the evaluation of deodorant efficacy was used before, and two hours, four hours, and eight hours after single application of a deodorant or placebo (ASTM method E 1207-87 Standard Practice for the Sensory Evaluation of Axillary Deodorancy. Results: The data were analyzed with two factors relating to densities and time. In 45 participants with a mean [± standard deviation (SD] age of 61.5±11.8 years, statistically significant within-group differences were observed before and two, four, and eight hours after deodorant treatment for groups 1, 2, and 3. Groups 1, 2, and 3 had a significantly smaller odor score than placebo after two, four, and eight hours

  1. Effectiveness of Advanced Stay Strong, Stay Healthy in Community Settings

    Directory of Open Access Journals (Sweden)

    Emily M. Crowe MS

    2015-07-01

    Full Text Available The goal of this research was to investigate the effectiveness of the 10-week, University of Missouri (MU Extension strength training program Advanced Stay Strong, Stay Healthy (ASSSH. It was hypothesized that the program can improve strength, balance, agility, and flexibility—all physical measures of falling among seniors. Matched pair t tests were used to compare differences in five physical measures of health, body composition, and percent body fat (%BF. Two-way ANOVA was conducted to examine the age effects on changes in physical health from the start and finish of the exercise program. Following programming, participants significantly improved strength, flexibility, and balance, and significantly reduced %BF ( p < .05. Our data indicate that ASSSH can improve the physical health of senior citizens and can successfully be translated into community practice by MU Extension professionals.

  2. Deodorant effects of a sage extract stick: Antibacterial activity and sensory evaluation of axillary deodorancy.

    Science.gov (United States)

    Shahtalebi, Mohammad Ali; Ghanadian, Mustafa; Farzan, Ali; Shiri, Niloufar; Shokri, Dariush; Fatemi, Syed Ali

    2013-10-01

    Deodorant products prevent the growth and activity of the degrading apocrine gland bacteria living in the armpit. Common antibacterial agents in the market like triclosan and aluminum salts, in spite of their suitable antibacterial effects, increase the risk of Alzheimer's disease, breast and prostate cancers or induce contact dermatitis. Therefore, plant extracts possessing antibacterial effects are of interest. The aim of the present study was to verify the in vitro antimicrobial effects of different sage extracts against two major bacteria responsible for axillary odor, and to evaluate the deodorant effect of a silicon-based stick containing sage extracts in different densities in humans. Different fractions of methanolic extract of Salvia officinalis (sage) were evaluated on a culture of armpit skin surface of volunteers through agar microdilution antimicrobial assay. Then, randomized, double-blind placebo-controlled clinical trial with the best antibacterial fraction was conducted on 45 female healthy volunteers. Participants were treated with a single dose in four groups, each containing 15 individuals: Group 1 (200 μg/mL), 2 (400 μg/mL), 3 (600 μg/mL) of dichloromethane sage extract, and placebo (without extract). A standard sensory evaluation method for the evaluation of deodorant efficacy was used before, and two hours, four hours, and eight hours after single application of a deodorant or placebo (ASTM method E 1207-87 Standard Practice for the Sensory Evaluation of Axillary Deodorancy). The data were analyzed with two factors relating to densities and time. In 45 participants with a mean [± standard deviation (SD)] age of 61.5±11.8 years, statistically significant within-group differences were observed before and two, four, and eight hours after deodorant treatment for groups 1, 2, and 3. Groups 1, 2, and 3 had a significantly smaller odor score than placebo after two, four, and eight hours (P sage extract sticks (P sage extract of 200, 400, or 600

  3. Antibacterial effect and physical properties of chitosan and chlorhexidine-cetrimide-modified glass ionomer cements.

    Science.gov (United States)

    Mishra, Apurva; Pandey, Ramesh Kumar; Manickam, Natesan

    2017-01-01

    To compare antibacterial effect and physical properties of chitosan (CH) modified glass ionomer cement (GIC) (10% v/v), chlorhexidine-cetrimide (CHX-CT) modified GIC (2.5/2.5% w/w) and conventional GIC. A total of fifty healthy children of age 7-12 years were selected and randomly assigned to class A and B for in vivo analysis. Slabs of CH modified GIC (Group II) along with slabs of conventional GIC (Group I, control) were cemented on buccal surfaces of maxillary molars (split-mouth technique) for class A children. Similarly, slabs of CHX-CT modified GIC (Group III) were cemented against control (Group I, control) in class B children. Slabs were assessed after 48 h for microbial load of Streptococcus mutans and Lactobacillus (LB) on mitis salivarius-bacitracin and Man Rogosa Sharpe agar media, respectively. Agar diffusion test was done to access the antibacterial effect of each group against Streptococcus muatns and LB. Slabs and cylinders of GICs were made for in vitro evaluation of compressive and flexure strength in each group. Comparison was done by nonparametric Kruskal-Wallis analysis followed by Dunn's multiple comparison test. Categorical groups were compared by Chi-square test. The increase in antibacterial activity (Group II > III > I) (P I > III) were observed. In the view of findings, it is concluded that CH modified GIC would be effective in inhibiting the bacteria associated with dental caries along with improved physical properties when compared with CHX-CT modified GIC and conventional GIC.

  4. Antibacterial effect and physical properties of chitosan and chlorhexidine-cetrimide-modified glass ionomer cements

    Directory of Open Access Journals (Sweden)

    Apurva Mishra

    2017-01-01

    Full Text Available Aims: To compare antibacterial effect and physical properties of chitosan (CH modified glass ionomer cement (GIC (10% v/v, chlorhexidine-cetrimide (CHX-CT modified GIC (2.5/2.5% w/w and conventional GIC. Materials and Methods: A total of fifty healthy children of age 7–12 years were selected and randomly assigned to class A and B for in vivo analysis. Slabs of CH modified GIC (Group II along with slabs of conventional GIC (Group I, control were cemented on buccal surfaces of maxillary molars (split-mouth technique for class A children. Similarly, slabs of CHX-CT modified GIC (Group III were cemented against control (Group I, control in class B children. Slabs were assessed after 48 h for microbial load of Streptococcus mutans and Lactobacillus (LB on mitis salivarius-bacitracin and Man Rogosa Sharpe agar media, respectively. Agar diffusion test was done to access the antibacterial effect of each group against Streptococcus muatns and LB. Slabs and cylinders of GICs were made for in vitro evaluation of compressive and flexure strength in each group. Results: Comparison was done by nonparametric Kruskal–Wallis analysis followed by Dunn's multiple comparison test. Categorical groups were compared by Chi-square test. The increase in antibacterial activity (Group II > III > I (P I > III were observed. Conclusions: In the view of findings, it is concluded that CH modified GIC would be effective in inhibiting the bacteria associated with dental caries along with improved physical properties when compared with CHX-CT modified GIC and conventional GIC.

  5. Antibacterial effect of some essential oils administered alone or in combination with Norfloxacin.

    Science.gov (United States)

    Rosato, Antonio; Vitali, Cesare; De Laurentis, Nicolino; Armenise, Domenico; Antonietta Milillo, Maria

    2007-11-01

    The objective of the present study was that of verifying a possible synergistic antibacterial effect between Pelargonium graveolens [Lis-Balchin, M., Deans, S.G., Hart, S., 1996. Bioactive Geranium oils from different commercial sources. J. Essential Oil Res. 8, 281-290.] essential oil (and its main components) and Norfloxacin antibiotic. As a first step growth inhibition by some types of essential oils was assessed in five microbial species. The antimicrobial effects of P. graveolens oil, as well as those of its components, were evaluated by means of the agar dilution method (ADM) against Bacillus cereus ATCC 11778, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 35218, Staphylococcus aureus ATCC 6538 and S. aureus ATCC 29213. The results obtained highlighted the occurrence of a pronounced synergism between P. graveolens essential oil and Norfloxacin against three of the five bacterial species under study with a FIC index in the 0.37-0.50 range. Such antibacterial effects were also shown to increase, although to a lesser extent, when Norfloxacin was given with the main components of P. graveolens essential oil. The combination of Norfloxacin with either P. graveolens essential oil, or with some of the main components of this latter, in the treatment of infections caused by some bacterial species is likely to reduce the minimum effective dose of Norfloxacin thus minimizing the side effects of the antibiotic.

  6. Antibacterial effect of dental adhesive containing dimethylaminododecyl methacrylate on the development of Streptococcus mutans biofilm.

    Science.gov (United States)

    Wang, Suping; Zhang, Keke; Zhou, Xuedong; Xu, Ning; Xu, Hockin H K; Weir, Michael D; Ge, Yang; Wang, Shida; Li, Mingyun; Li, Yuqing; Xu, Xin; Cheng, Lei

    2014-07-18

    Antibacterial bonding agents and composites containing dimethylaminododecyl methacrylate (DMADDM) have been recently developed. The objectives of this study were to investigate the antibacterial effect of novel adhesives containing different mass fractions of DMADDM on Streptococcus mutans (S. mutans) biofilm at different developmental stages. Different mass fractions of DMADDM were incorporated into adhesives and S. mutans biofilm at different developmetal stages were analyzed by MTT assays, lactic acid measurement, confocal laser scanning microscopy and scanning electron microscopy observations. Exopolysaccharides (EPS) staining was used to analyze the inhibitory effect of DMADDM on the biofilm extracellular matrix. Dentin microtensile strengths were also measured. Cured adhesives containing DMADDM could greatly reduce metabolic activity and lactic acid production during the development of S. mutans biofilms (p biofilm development, there were no significant differences of inhibitory effects between the 2.5% DMADDM and 5% DMADDM group. However, after 72 h, the anti-biofilm effects of adhesives containing 5% DMADDM were significantly stronger than any other group. Incorporation of DMADDM into adhesive did not adversely affect dentin bond strength. In conclusion, adhesives containing DMADDM inhibited the growth, lactic acid production and EPS metabolism of S. mutans biofilm at different stages, with no adverse effect on its dentin adhesive bond strength. The bonding agents have the potential to control dental biofilms and combat tooth decay, and DMADDM is promising for use in a wide range of dental adhesive systems and restoratives.

  7. Antibacterial Effect of Dental Adhesive Containing Dimethylaminododecyl Methacrylate on the Development of Streptococcus mutans Biofilm

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    Suping Wang

    2014-07-01

    Full Text Available Antibacterial bonding agents and composites containing dimethylaminododecyl methacrylate (DMADDM have been recently developed. The objectives of this study were to investigate the antibacterial effect of novel adhesives containing different mass fractions of DMADDM on Streptococcus mutans (S. mutans biofilm at different developmental stages. Different mass fractions of DMADDM were incorporated into adhesives and S. mutans biofilm at different developmetal stages were analyzed by MTT assays, lactic acid measurement, confocal laser scanning microscopy and scanning electron microscopy observations. Exopolysaccharides (EPS staining was used to analyze the inhibitory effect of DMADDM on the biofilm extracellular matrix. Dentin microtensile strengths were also measured. Cured adhesives containing DMADDM could greatly reduce metabolic activity and lactic acid production during the development of S. mutans biofilms (p < 0.05. In earlier stages of biofilm development, there were no significant differences of inhibitory effects between the 2.5% DMADDM and 5% DMADDM group. However, after 72 h, the anti-biofilm effects of adhesives containing 5% DMADDM were significantly stronger than any other group. Incorporation of DMADDM into adhesive did not adversely affect dentin bond strength. In conclusion, adhesives containing DMADDM inhibited the growth, lactic acid production and EPS metabolism of S. mutans biofilm at different stages, with no adverse effect on its dentin adhesive bond strength. The bonding agents have the potential to control dental biofilms and combat tooth decay, and DMADDM is promising for use in a wide range of dental adhesive systems and restoratives.

  8. Synergistic Antibacterial Effects of Polyphenolic Compounds from Olive Mill Wastewater

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    Ahmed Tafesh

    2011-01-01

    Full Text Available Polyphenols or phenolic compounds are groups of secondary metabolites widely distributed in plants and found in olive mill wastewater (OMW. Phenolic compounds as well as OMW extracts were evaluated in vitro for their antimicrobial activity against Gram-positive (Streptococcus pyogenes and Staphylococcus aureus and Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae. Most of the tested phenols were not effective against the four bacterial strains when tested as single compounds at concentrations of up to 1000 μg mL−1. Hydroxytyrosol at 400 μg mL−1 caused complete growth inhibition of the four strains. Gallic acid was effective at 200, and 400 μg mL−1 against S. aureus, and S. pyogenes, respectively, but not against the gram negative bacteria. An OMW fraction called AntiSolvent was obtained after the addition of ethanol to the crude OMW. HPLC analysis of AntiSolvent fraction revealed that this fraction contains mainly hydroxytyrosol (10.3%, verbascoside (7.4%, and tyrosol (2.6%. The combinations of AntiSolvent/gallic acid were tested using the low minimal inhibitory concentrations which revealed that 50/100–100/100 μg mL−1 caused complete growth inhibition of the four strains. These results suggest that OMW specific fractions augmented with natural phenolic ingredients may be utilized as a source of bioactive compounds to control pathogenic bacteria.

  9. Antibacterial and Sterilizing Effect of Benzylpenicillin in Tuberculosis.

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    Deshpande, Devyani; Srivastava, Shashikant; Bendet, Paula; Martin, Katherine R; Cirrincione, Kayle N; Lee, Pooi S; Pasipanodya, Jotam G; Dheda, Keertan; Gumbo, Tawanda

    2018-02-01

    The modern chemotherapy era started with Fleming's discovery of benzylpenicillin. He demonstrated that benzylpenicillin did not kill Mycobacterium tuberculosis In this study, we found that >64 mg/liter of static benzylpenicillin concentrations killed 1.16 to 1.43 log 10 CFU/ml below starting inoculum of extracellular and intracellular M. tuberculosis over 7 days. When we added the β-lactamase inhibitor avibactam, benzylpenicillin maximal kill ( E max ) of extracellular log-phase-growth M. tuberculosis was 6.80 ± 0.45 log 10 CFU/ml at a 50% effective concentration (EC 50 ) of 15.11 ± 2.31 mg/liter, while for intracellular M. tuberculosis it was 2.42 ± 0.14 log 10 CFU/ml at an EC 50 of 6.70 ± 0.56 mg/liter. The median penicillin (plus avibactam) MIC against South African clinical M. tuberculosis strains (80% either multidrug or extensively drug resistant) was 2 mg/liter. We mimicked human-like benzylpenicillin and avibactam concentration-time profiles in the hollow-fiber model of tuberculosis (HFS-TB). The percent time above the MIC was linked to effect, with an optimal exposure of ≥65%. At optimal exposure in the HFS-TB, the bactericidal activity in log-phase-growth M. tuberculosis was 1.44 log 10 CFU/ml/day, while 3.28 log 10 CFU/ml of intracellular M. tuberculosis was killed over 3 weeks. In an 8-week HFS-TB study of nonreplicating persistent M. tuberculosis , penicillin-avibactam alone and the drug combination of isoniazid, rifampin, and pyrazinamide both killed >7.0 log 10 CFU/ml. Monte Carlo simulations of 10,000 preterm infants with disseminated disease identified an optimal dose of 10,000 U/kg (of body weight)/h, while for pregnant women or nonpregnant adults with pulmonary tuberculosis the optimal dose was 25,000 U/kg/h, by continuous intravenous infusion. Penicillin-avibactam should be examined for effect in pregnant women and infants with drug-resistant tuberculosis, to replace injectable ototoxic and teratogenic second-line drugs. Copyright © 2018

  10. Concentration ranges of antibacterial cations for showing the highest antibacterial efficacy but the least cytotoxicity against mammalian cells: implications for a new antibacterial mechanism.

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    Ning, Chengyun; Wang, Xiaolan; Li, Lihua; Zhu, Ye; Li, Mei; Yu, Peng; Zhou, Lei; Zhou, Zhengnan; Chen, Junqi; Tan, Guoxin; Zhang, Yu; Wang, Yingjun; Mao, Chuanbin

    2015-09-21

    Antibacterial metal ions, such as Ag(+), Zn(2+) and Cu(2+), have been extensively used in medical implants and devices due to their strong broad spectrum of antibacterial activity. However, it is still a controversial issue as to whether they can show the desired antibacterial activity while being toxic to mammalian cells. It is very important to balance their antibacterial effectiveness with minimal damage to mammalian cells. Toward this end, this study is to identify the suitable concentrations of these three ions at which they can effectively kill two types of clinically relevant bacteria (Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli)) but show no obvious cytotoxicity on fibroblasts. Such concentration ranges are found to be 2.5 × 10(-7) M-10(-6) M, 10(-5) M-10(-4) M, and 10(-5) M-10(-4) M for Ag(+), Zn(2+), and Cu(2+), respectively. Investigation of their antibacterial mechanism shows that these three metal ions all show antibacterial property through a mechanism of damaging bacterial cell membranes by the generation of reactive oxygen species but surprisingly preserving the integrity of bacterial genomic DNA. The encouraging results indicate that antibacterial metal ions with controlled concentrations can bring considerable benefits to biomedical applications.

  11. Synergistic Antibacterial Effects of Chitosan-Caffeic Acid Conjugate against Antibiotic-Resistant Acne-Related Bacteria

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    Ji-Hoon Kim

    2017-06-01

    Full Text Available The object of this study was to discover an alternative therapeutic agent with fewer side effects against acne vulgaris, one of the most common skin diseases. Acne vulgaris is often associated with acne-related bacteria such as Propionibacterium acnes, Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa. Some of these bacteria exhibit a resistance against commercial antibiotics that have been used in the treatment of acne vulgaris (tetracycline, erythromycin, and lincomycin. In the current study, we tested in vitro antibacterial effect of chitosan-phytochemical conjugates on acne-related bacteria. Three chitosan-phytochemical conjugates used in this study exhibited stronger antibacterial activity than that of chitosan (unmodified control. Chitosan-caffeic acid conjugate (CCA showed the highest antibacterial effect on acne-related bacteria along with minimum inhibitory concentration (MIC; 8 to 256 μg/mL. Additionally, the MIC values of antibiotics against antibiotic-resistant P. acnes and P. aeruginosa strains were dramatically reduced in combination with CCA, suggesting that CCA would restore the antibacterial activity of the antibiotics. The analysis of fractional inhibitory concentration (FIC indices clearly revealed a synergistic antibacterial effect of CCA with antibiotics. Thus, the median sum of FIC (∑FIC values against the antibiotic-resistant bacterial strains ranged from 0.375 to 0.533 in the combination mode of CCA and antibiotics. The results of the present study suggested a potential possibility of chitosan-phytochemical conjugates in the control of infections related to acne vulgaris.

  12. Synergistic Antibacterial Effects of Chitosan-Caffeic Acid Conjugate against Antibiotic-Resistant Acne-Related Bacteria.

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    Kim, Ji-Hoon; Yu, Daeung; Eom, Sung-Hwan; Kim, Song-Hee; Oh, Junghwan; Jung, Won-Kyo; Kim, Young-Mog

    2017-06-08

    The object of this study was to discover an alternative therapeutic agent with fewer side effects against acne vulgaris, one of the most common skin diseases. Acne vulgaris is often associated with acne-related bacteria such as Propionibacterium acnes , Staphylococcus epidermidis , Staphylococcus aureus , and Pseudomonas aeruginosa . Some of these bacteria exhibit a resistance against commercial antibiotics that have been used in the treatment of acne vulgaris (tetracycline, erythromycin, and lincomycin). In the current study, we tested in vitro antibacterial effect of chitosan-phytochemical conjugates on acne-related bacteria. Three chitosan-phytochemical conjugates used in this study exhibited stronger antibacterial activity than that of chitosan (unmodified control). Chitosan-caffeic acid conjugate (CCA) showed the highest antibacterial effect on acne-related bacteria along with minimum inhibitory concentration (MIC; 8 to 256 μg/mL). Additionally, the MIC values of antibiotics against antibiotic-resistant P. acnes and P. aeruginosa strains were dramatically reduced in combination with CCA, suggesting that CCA would restore the antibacterial activity of the antibiotics. The analysis of fractional inhibitory concentration (FIC) indices clearly revealed a synergistic antibacterial effect of CCA with antibiotics. Thus, the median sum of FIC (∑FIC) values against the antibiotic-resistant bacterial strains ranged from 0.375 to 0.533 in the combination mode of CCA and antibiotics. The results of the present study suggested a potential possibility of chitosan-phytochemical conjugates in the control of infections related to acne vulgaris.

  13. Vitellogenin from the silkworm, Bombyx mori: an effective anti-bacterial agent.

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    Nitin Kumar Singh

    Full Text Available Silkworm, Bombyx mori, vitellogenin (Vg was isolated from perivisceral fat body of day 3 of pupa. Both Vg subunits were co-purified as verified by mass spectrometry and immunoblot. Purified Vg responded to specific tests for major posttranslational modifications on native gels indicating its nature as lipo-glyco-phosphoprotein. The Vg fraction had strong antibacterial activity against Gram negative bacterium Escherichia coli and Gram positive bacterium Bacillus subtilis. Microscopic images showed binding of Vg to bacterial cells and their destruction. When infected silkworm larvae were treated with purified Vg they survived the full life cycle in contrast to untreated animals. This result showed that Vg has the ability to inhibit the proliferation of bacteria in the silkworm fluid system without disturbing the regular metabolism of the host.

  14. On the antibacterial effects of manuka honey: mechanistic insights

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    Roberts AEL

    2015-10-01

    Full Text Available Aled Edward Lloyd Roberts,* Helen Louise Brown,* Rowena Eleri Jenkins Department of Biomedical Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK *These authors contributed equally to this work Abstract: Antimicrobial resistance (AMR is an increasing clinical problem precipitated by the inappropriate use of antibiotics in the later parts of the 20th Century. This problem, coupled with the lack of novel therapeutics in the development pipeline, means AMR is reaching crisis point, with an expected annual death rate of ten million people worldwide by 2050. To reduce, and to potentially remedy this problem, many researchers are looking into natural compounds with antimicrobial and/or antivirulence activity. Manuka honey is an ancient antimicrobial remedy with a good track record against a wide range of nosocomial pathogens that have increased AMR. Its inhibitory effects are the result of its constituent components, which add varying degrees of antimicrobial efficacy to the overall activity of manuka honey. The antimicrobial efficacy of manuka honey and some of its constituent components (such as methylglyoxal and leptosperin are known to bestow some degree of antimicrobial efficacy to manuka honey. Despite growing in vitro evidence of its antimicrobial efficacy, the in vivo use of manuka honey (especially in a clinical environment has been unexpectedly slow, partly due to the lack of mechanistic data. The mechanism by which manuka honey achieves its inhibitory efficacy has recently been identified against Staphylococcus aureus and Pseudomonas aeruginosa, with both of these contrasting organisms being inhibited through different mechanisms. Manuka honey inhibits S. aureus by interfering with the cell division process, whereas P. aeruginosa cells lyse in its presence due to the reduction of a key structural protein. In addition to these inhibitory effects, manuka honey is known to reduce virulence, motility, and biofilm formation. With this

  15. Light-activated nanofibre textiles exert antibacterial effects in the setting of chronic wound healing.

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    Arenbergerova, Monika; Arenberger, Petr; Bednar, Marek; Kubat, Pavel; Mosinger, Jiri

    2012-08-01

    The maintenance of an aseptic environment for chronic wounds is one of the most challenging tasks in the wound-healing process. Furthermore, the emergence of antibiotic-resistant bacterial strains is on the rise, rendering conventional treatments less effective. A new antibacterial material consisting of a polyurethane Tecophilic(™) nanofibre textile (NT) that was prepared by electrospinning and doped by a tetraphenylporphyrin (TPP) photosensitizer activated by visible light was tested for use in wound beds and bandages. In vitro experiments were performed to assess the antibacterial activity of the textile against three bacterial strains. Furthermore, the new textile was tested in 162 patients with chronic leg ulcers. A complete inhibition of in vitro growth of the three tested bacterial strains was observed on the surface of NTs that had been illuminated with visible light and was clinically demonstrated in 89 patients with leg ulcers. The application of the textiles resulted in a 35% decrease in wound size, as assessed via computer-aided wound tracing. Wound-related pain, which was estimated using a visual analogue scale, was reduced by 71%. The results of this trial reveal that the photoinactivation of bacteria through the photosensitized generation of short-lived, highly reactive singlet oxygen O(2) ((1) Δ(g) ) results in relatively superficial antibacterial effects in comparison with standard antiseptic treatment options. Thus, such treatment does not interfere with the normal healing process. This method therefore represents a suitable alternative to the use of topical antibiotics and antiseptics and demonstrates potentially broad applications in medicine. © 2012 John Wiley & Sons A/S.

  16. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study.

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    Millo, Grazielle; Juntavee, Apa; Ratanathongkam, Ariya; Nualkaew, Natsajee; Peerapattana, Jomjai; Chatchiwiwattana, Supaporn

    2017-01-01

    This study evaluated the in vitro antibacterial effects of the formulated Punica granatum (PG) gel against Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus casei. The PG extract was dissolved in water at 500 mg/mL. High performance liquid chromatography (HPLC) was used for identification and quantification of chemical marker punicalagin. Minimum bactericidal concentration (MBC) and time-kill assay (TKA) were investigated. Antibacterial activities of the formulated PG gel, 2% chlorhexidine (CHX) gel and blank gel were tested by measuring the zones of inhibition through agar well diffusion method. The HPLC results showed presence of punicalagin at 2023.58 ± 25.29 pg/mL in the aqueous PG extract and at 0.234% (w/w) in the formulated PG gel. The MBC for S. mutans, S. Sanguinis, and L. casei were 250, 125, and 500 mg/mL respectively. The TKA of 500 mg/mL aqueous PG extract showed total inhibition of S. mutans, S. Sanguinis, and L. casei at 6, 1, and 24 hours contact time respectively. Agar well diffusion revealed that for S. mutans, CHX gel > PG gel > blank gel; for S. sanguinis, CHX gel = PG gel > blank gel; for L. casei, CHX gel > PG gel = blank gel. Comparison of the PG gel potency showed that S. sanguinis = S. mutans > L. casei. The PG gel equivalent to 0.234% punicalagin (w/w) inhibited S. mutans and S. sanguinis but not L. casei within 24 hours incubation period and has the potential to be used for caries prevention. Millo G, Juntavee A, Ratanathongkam A, Nualkaew N, Peerapattana J, Chatchiwiwattana S. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study. Int J Clin Pediatr Dent 2017;10(2):152-157.

  17. Ozone gas is an effective and practical antibacterial agent.

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    Sharma, Manju; Hudson, James B

    2008-10-01

    Bacterial infections continue to pose a threat to health in many institutional and communal settings, and epidemics are frequent. Current control measures are clearly inadequate; thus, there is a need for a simple, effective, and safe way to decontaminate surfaces. We evaluated the efficacy of a portable ozone-generating machine, equipped with a catalytic converter and an accessory humidifier, to inactivate 15 different species of medically important bacteria. An ozone dosage of 25 ppm for 20 minutes, with a short burst of humidity in excess of 90% relative humidity, was able to inactivate more than 3 log(10) colony-forming units of most of the bacteria, including Acinetobacter baumannii, Clostridium difficile, and methicillin-resistant Staphylococcus aureus, in both in a laboratory test system and simulated field conditions. In many cases, complete eradication was achieved. Dried and wet samples were equally vulnerable to the ozone. Inactivation of bacterial samples dried onto soft surfaces (eg, fabric, cotton, filter paper) were comparable with that observed for samples on plastic. The ozone generator can provide a valuable decontamination tool for the removal of bacteria in many institutional and communal settings, including hospitals and other health care institutions.

  18. FORMATION OF ANTIBACTERIAL EFFECT ON CERAMIC TILE SURFACES

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    Selçuk ÖZCAN

    2017-03-01

    Full Text Available Biocidal antimicrobial molecular barrier (BAMB solutions are known to provide antimicrobial effect on the surfaces in industrial applications. However, there has been a lack of scientific reports about the subject in the literature. In this study, in order to impart an antimicrobial surface property on ceramic surfaces, a BAMB solution was applied on gloss fired ceramic wall tile substrates and the surface antimicrobial activity results were compared with that of plain wall tiles (without BAMB application. The ceramic surfaces were cleaned, and stove dried at120°C prior to spray coating with a BAMB solution. The coated substrates were dried in the ambient. The intactness of the coatings was checked with the bromophenol blue test. The microstructural and molecular characterization of the BAMB coated surfaces were carried out with SEM imaging and surface FTIR, respectively. The antimicrobial activity tests of the surfaces were conducted according to ASTM E2180-07 (Standard Test Method for Determining the Activity of Incorporated Antimicrobial Agent in Polymeric or Hydrophobic Materials. The microorganisms used were Staphylococcus aureus (ATCC 6538 and Pseudomonas aeruginosa (ATCC 15442 bacteria. The BAMB coated surfaces showed less flocculent bacterial growth in comparison to uncoated ceramic surfaces leading to the conclusion that the BAMB improved the antimicrobial property.

  19. The Effect of Culture Medium on Metabolic and Antibacterial Activities of Probiotic Bacteria

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    Mirdavoudi F

    2012-01-01

    Full Text Available Background and Objectives: Probiotic bacteria is added directly to food components and it has beneficial effect on function and the health of organisms. The bifidogenic factors enter the colon where they contribute to an increase lactic acid bacteria population including Lactobacilli and Bifidobacteria and they inhibit enteric pathogenic bacterial growth. The aim of this study is to investigate the effect of culture medium on metabolic and antibacterial of probiotic bacteria.Methods: In this study, the probiotics bacterial and intestine pathogenic are to be used. Lactobacilli and Bifidobacterium were identified by plating samples on MRS medium, Gram Staining and standard biochemical methods. The effect of antagonistic probiotics was investigated in the presence of growth factor in the method well diffusion Ager on the Shigella flexneri (PTCC 1234, Escherichia coli (PTCC 1552, Salmonella typhi ( PTCC 1609 and the culture medium pH was measured.Results: The probiotics bacterial growth in MRS and lactose1%, sorbitol, raffinose, riboflavin were shown the effect antibacterial. The results of the study show the most antagonistic activity in commercial strain Lactobacillus acidophilus on Shigella flexneri and lower activity was in Lactobacillus casei (PTCC 1608, and Salmonella typhimurium (PTCC 1609, and also in Bbifidobacterium bifidum, it showed the most decrease pH value.Conclusion: According to the result of the study, adding growth factors to MRS medium base and lactose 1%, probiotic growth was increased and which also increased antagonistic activity.

  20. COMPARATIVE CHARACTERISTICS OF ANTIBACTERIAL EFFECT OF SILVER AND NANOSILVER IN VITRO

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    E. N. Petritskaya

    2016-01-01

    Full Text Available Rationale: The problem of the resistance of microorganisms to many classes of antimicrobial agents becomes increasingly threatening. This promotes the search of new formulations for prevention and treatment of infectious inflammation. Aim: To evaluate antibacterial effects of silver nanoparticle colloid solutions on gram-negative, gram-positive and fungal microflora compared to already known formulations based on silver salts and nitrates of other metals. Materials and methods: The effects of silver nanoparticle colloid solutions (with concentration of nanoparticles of 50 and 100 mg/mL, particle diameter of 15±5 nm on the microorganism growth were studied in Staphylococcus aureus (# 209P, Escherichia coli (# 26941, Klebsiella pneumoniae (#  43062 and clinical isolates of Candida albicans. For comparison, silver proteinate, nitrofural, and solutions of NaNO₃, Sn(NO₃₂, Co(NO₃₂ and Zn(NO₃₂ at equimolar concentrations to AgNO₃ 1% were used. Results: After the plates with test cultures were treated with silver nanoparticle solutions and with comparator solutions, there was sheer culture growth in the areas of silver nanoparticle application (at both concentrations and no growth in the areas of the comparator solutions application. Conclusion: The results obtained indicate that silver nanoparticle colloid solutions 50 and 100 mg/mL do not influence the growth of the studied cultures, whereas the comparator solutions exert an advanced antibacterial effect.

  1. Antibacterial and Antibiofilm Effect of Low Viscosity Chitosan against Staphylococcus epidermidis

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    Inger Sofie Dragland

    2016-01-01

    Full Text Available Aim. The aim of this study was to investigate the antibacterial and antibiofilm properties of low viscosity chitosan on S. epidermidis growth and biofilm formation. Methods and Results. The antibacterial and antibiofilm properties were investigated, during both planktonic growth and biofilm formation. This was performed using different concentrations in media and by coating on polystyrene surfaces. In addition, the bactericidal effect was investigated using a modified direct contact test. The results showed that low viscosity chitosan in media had both a bacteriostatic and bactericidal effect on planktonic growth and biofilm formation of S. epidermidis in a concentration dependent manner. Polystyrene discs coated with chitosan reduced both early biofilm formation (6 h and late biofilm formation (18 h, as confirmed by scanning electron microscopy. The modified direct contact test showed a bactericidal effect. Conclusion. This study demonstrated that low viscosity chitosan has a bacteriostatic and bactericidal activity against S. epidermidis and that the activity is dependent on the amount of chitosan added. In addition, low viscosity chitosan reduced biofilm formation both when added to media and when coated on polystyrene surfaces. Significance and Impact of Study. Low viscosity chitosan could be a contribution to new treatment approaches of biofilm-related infections of S. epidermidis.

  2. Concomitant chemopreventive and antibacterial effects of some Iranian plants from the genus Cousinia (Asteraceae

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    Ahmad Reza Shahverdi

    Full Text Available During the past several years, various species of Cousinia (Asteraceae have been authenticated in Iran. However, data concerning their biological activities remain limited. The main purpose of this research was to assess potential cytotoxicity and matrix metalloproteinases (MMP inhibitory effects of seven ethanol extracts of Cousinia using a cell line model (Fibrosarcoma-WEHI 164. We further investigated the antibacterial activity of these Cousinia ethanol extracts, using disk diffusion method. Among the ethanol extracts, the total extract of C. sulabadensis elicited significant inhibition of MMP activity in a dose-response fashion (49.2 ± 0.51, p < 0.05. However, this extract exhibited the lowest cytotoxicity effect at all tested concentrations. The concentration necessary to produce a 50% cell death rate (IC50 with C. shulabadensis was 304.5 ± 0.61 µg/mL. The calculated IC50 for cytotoxicity of the other Cousinia species extracts ranged between 18.4 ± 0.59 to 87.9 ± 0.58 µg/mL. The highest antibacterial activity was observed for the total extract of Cousinia phyllocephala. In conclusion, this study supports that Cousinia species display a remarkable inhibition of matrix metalloproteinases activity. The concomitant MMP-inhibitory and low cytotoxicity effects observed in C. sulabadensis might coin this extract for future potential anti-invasive herbal medicine studies.

  3. Antibacterial effects of castor oil on foodborne pathogens: comparative evaluation of the components

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    samaneh hatami

    2016-01-01

    Full Text Available For centuries, antimicrobial compounds derived from plants, have been used for medicinal treatment. The aim of this study was to evaluate the antibacterial activity of castor seed oil extracted from Mashhad and Isfahan varieties on Staphylococcus aureus, Escherichia coli and Listeria inocula. The sensitivity of the indicator bacteria was evaluated using disc diffusion technique and minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were tested by broth micro-dilution assays. Oil from castor seeds was extract by Soxhlet method and the extracted oils were analyzed by a gas chromatograph connected to a mass spectrometer (GC/MS. According to the results of various dilutions of the extracts, MIC for castor oils ranged 12.5-25%, except for the Isfahan variety that was estimated at 6.25-12.5% for E. coli. The two varieties of castor oils showed the MBC activity on the indicator organisms at the original (100% concentration. Based on GC/MS data, ricinoleic acid (1.307%, genetistic acid (0.597% and palmitic acid (1.947% were detected in oil extracted from Isfahan variety; meanwhile these compounds did not found in Mashhad variety. According to the results, the two castor varieties had antibacterial impact on E. coli. In addition, the overall antimicrobial activity of Isfahan variety was higher than Mashhad type. It seems that the presence of phenolic compounds as well as camphoric and unsaturated fatty acids is the major reason for the higher antibacterial effect of Isfahan variety on E. coli. Considering the inhibitory impact of castor oil, it can be used as a natural preservative in food industry.

  4. Green synthesis and antibacterial effect of silver nanoparticles using Eucalyptus camaldulensis

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    Samaneh Dolatabadi

    2017-11-01

    Full Text Available Introduction and Aims: Due to the developing bacterial drug resistance to classical antimicrobial agents, it seems necessary to produce an innovative therapeutic approach to eliminate resistant pathogens. This study aimed to biosynthesis of silver nanoparticles (AgNPs using flowers extract of Eucalyptus camaldulensis and determined of antibacterial activity of produced AgNPs.  Materials and Methods: We used an environmentally friendly extracellular biosynthetic technique for the production of the AgNPs. The reducing agents used to produce the nanoparticles were from the aqueous flowers extract of Eucalyptus camaldulensis. The AgNPs were characterized by color changes, the UV-visible spectroscopy, FTIR analysis, XRD patterns and Scanning Electron Microscopy (SEM technique. The antibacterial activity of AgNPs was investigated against Gram-positive and Gram-negative bacteria ,through broth micro dilution (MIC values and MBC (Minimum bactericidal concentration assays. Results: An absorption peak at 413 nm and the color change to dark brown were corresponding to the plasmon absorbance of AgNPs and then were performed by FTIR and XRD methods. The average size of nanoparticles was observed between 67 and 80 nm. Furthermore, the MIC value of extract against Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa were 3.12, 6.25, and 50 mg/mL, respectively. The corresponding MBC values were 6.25, 6.25 and 100 mg/mL, respectively. Conclusion: Our findings confirmed that extracellular synthesis of AgNPs mediated by E. camaldulensis flowers extract indicated a good bactericidal activity against the tested bacteria and can be used in various fields as an antibacterial agent. Further studies are needed to characterize the toxicity effect of these particles.

  5. Protective effects of soybean protein and egg white protein on the antibacterial activity of nisin in the presence of trypsin.

    Science.gov (United States)

    Pan, Dan; Zhang, Dong; Hao, Limin; Lin, Songyang; Kang, Qiaozhen; Liu, Xin; Lu, Laizheng; Lu, Jike

    2018-01-15

    The using of nisin to prevent foodborne pathogens (Staphylococcus aureus and Listeria monocytogenes) from contamination has received broad attentions during meat processing. However, the application of nisin has been limited because its antibacterial activity may be inhibited by trypsin. In this study, the protective effects of soybean protein and egg white protein on antibacterial activity of nisin were evaluated. It could be concluded that exogenous trypsin decreased the antibacterial activity of nisin, soybean protein and egg white protein could keep the nisin activity from enzymolysis of trypsin. Trypsin inhibitors in soybean protein and egg white protein could protect the antibacterial activity of nisin. Nisin with soybean protein or egg white protein in cooked meat product presented better quality preservation effects than nisin alone in the presence of trypsin. The total viable counts (TVC) and total volatile basic nitrogen (TVB-N) of nisin-treated group were significantly higher than these in nisin-soybean protein-treated and nisin-egg white protein-treated groups with trypsin. This study showed the potential of using soybean protein and egg white protein to stabilize the antibacterial activity of nisin under high trypsin conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Evaluation of antibacterial effect of some Sinai medicinal plant extracts on bacteria isolated from bovine mastitis

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    Gamil S. G. Zeedan

    2014-11-01

    for the extracts ranged from 0.01 to 1.56 mg/ml. when comparing antibacterial activity of A. herb alba plant extracted with acetone solvent on the same bacteria with zone of inhibition values ± SD, ranging from 00±00 to 5.6±0.60 mm. Both extracts from J. montana and A. herb alba plant extracts with petroleum ether, methanol and chloroform solvent were less antibacterial activities than acetone solvent extract. Conclusion: The present study spot highlight on isolation and identification of mastitis pathogens that are fundamental aspects of milk quality, udder health control programs and public health and food safety issues associated with food borne pathogens. J. montana and A. herb alba plants have antibacterial effects more than antibiotics used in the treatment of mastitis. Finally, the medicinal plant extracts can be used to discover bioactive natural product in the form of antibacterial that may be serve the development of new pharmaceutical products. But still need further research necessary to identify active compounds and research to mechanism and drug interaction.

  7. Antioxidant, antibacterial and in vivo dermal wound healing effects of Opuntia flower extracts.

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    Ammar, Imene; Bardaa, Sana; Mzid, Massara; Sahnoun, Zouheir; Rebaii, Tarak; Attia, Hamadi; Ennouri, Monia

    2015-11-01

    Opuntia ficus-indica flowers are used for various medicinal purposes. The aims of the present investigation were to evaluate biological properties of O. ficus-indica flowers extracts and to investigate its antioxidant and antibacterial activities and its ability to enhance wound healing. The wound healing activity of the mucilaginous and methanol extracts of O. ficus-indica flowers were assessed using excision wound model in rats. After thirteen days of treatment by both extracts, a beneficial effect on cutaneous repair was observed as assessed by the acceleration of wound contraction and remodeling phases. Histopathological studies of the granulation tissue indicated that the derma is properly arranged with the Opuntia flowers extract, compared with the control group. The mucilage extract was more effective than the methanol extract, but both showed significant results compared with the control. Such investigation was supported by the efficiency of the methanolic and mucilage extract as antimicrobial and antioxidant. Indeed, the extracts showed a potential antioxidant activity determined by different test systems, namely DPPH radicals scavenging activity, trolox equivalent antioxidant capacity, reducing power, β-carotene bleaching assay and metal chelating activity and exhibited significant antibacterial activity against almost all tested bacteria. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Bulk Surfaces Coated with Triangular Silver Nanoplates: Antibacterial Action Based on Silver Release and Photo-Thermal Effect

    Directory of Open Access Journals (Sweden)

    Agnese D’Agostino

    2017-01-01

    Full Text Available A layer of silver nanoplates, specifically synthesized with the desired localized surface plasmon resonance (LSPR features, was grafted on amino-functionalized bulk glass surfaces to impart a double antibacterial action: (i the well-known, long-term antibacterial effect based on the release of Ag+; (ii an “on demand” action which can be switched on by the use of photo-thermal properties of silver nano-objects. Irradiation of these samples with a laser having a wavelength falling into the so called “therapeutic window” of the near infrared region allows the reinforcement, in the timescale of minutes, of the classical antibacterial effect of silver nanoparticles. We demonstrate how using the two actions allows for almost complete elimination of the population of two bacterial strains of representative Gram-positive and Gram-negative bacteria.

  9. Bulk Surfaces Coated with Triangular Silver Nanoplates: Antibacterial Action Based on Silver Release and Photo-Thermal Effect.

    Science.gov (United States)

    D'Agostino, Agnese; Taglietti, Angelo; Desando, Roberto; Bini, Marcella; Patrini, Maddalena; Dacarro, Giacomo; Cucca, Lucia; Pallavicini, Piersandro; Grisoli, Pietro

    2017-01-06

    A layer of silver nanoplates, specifically synthesized with the desired localized surface plasmon resonance (LSPR) features, was grafted on amino-functionalized bulk glass surfaces to impart a double antibacterial action: (i) the well-known, long-term antibacterial effect based on the release of Ag⁺; (ii) an "on demand" action which can be switched on by the use of photo-thermal properties of silver nano-objects. Irradiation of these samples with a laser having a wavelength falling into the so called "therapeutic window" of the near infrared region allows the reinforcement, in the timescale of minutes, of the classical antibacterial effect of silver nanoparticles. We demonstrate how using the two actions allows for almost complete elimination of the population of two bacterial strains of representative Gram-positive and Gram-negative bacteria.

  10. Synergistic antibacterial effects of β-lactam antibiotic combined with silver nanoparticles

    Science.gov (United States)

    Li, Ping; Li, Juan; Wu, Changzhu; Wu, Qingsheng; Li, Jian

    2005-09-01

    The bactericidal action of silver (0) nanoparticles and amoxicillin on Escherichia coli is studied, respectively. Increasing concentration of both amoxicillin (0-0.525 mg ml-1) and silver nanoparticles (0-40 µg ml-1) showed a higher antibacterial effect in Luria-Bertani (LB) medium. Escherichia coli cells have different bactericidal sensitivity to them. When amoxicillin and silver nanoparticles are combined, it results in greater bactericidal efficiency on Escherichia coli cells than when they were applied separately. Dynamic tests on bacterial growth indicated that exponential and stationary phases are greatly decreased and delayed in the synergistic effect of amoxicillin and silver nanoparticles. In addition, the effect induced by a preincubation with silver nanoparticles is examined. The results show that solutions with more silver nanoparticles have better antimicrobial effects. One hypothesized mechanism is proposed to explain this phenomenon.

  11. In vitro and in vivo study of the antibacterial effects of Nigella sativa methanol extract in dairy cow mastitis

    Directory of Open Access Journals (Sweden)

    Hassan Rakhshandeh

    2011-07-01

    Results and conclusion: The extract showed significant in vitro and in vivo inhibitory effects on causative organisms compared to standard drugs and also induced healing of the disease. This is the first veterinary experiment, to our knowledge, that investigated the antibacterial effects of Nigella sativa.

  12. Quercetin-loaded PLGA nanoparticles: a highly effective antibacterial agent in vitro and anti-infection application in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Dongdong; Li, Nuan; Zhang, Weiwei; Yang, Endong; Mou, Zhipeng; Zhao, Zhiwei; Liu, Haiping; Wang, Weiyun, E-mail: weiywswzy@163.com [Anhui Agricultural University, School of Life Sciences (China)

    2016-01-15

    Nanotechnology-based approaches have tremendous potential for enhancing efficacy against infectious diseases. PLGA-based nanoparticles as drug delivery carrier have shown promising potential, owing to their sizes and related unique properties. This article aims to develop nanosized poly (d, l-lactide-co-glycolide) PLGA nanoparticle formulation loaded with quercetin (QT). QT is an antioxidant and antibacterial compound isolated from Chinese traditional medicine with low skin permeability and extreme water insolubility. The quercetin-loaded PLGA nanoparticles (PQTs) were synthesized by emulsion–solvent evaporation method and stabilized by coating with poly (vinyl alcohol). The characteristics of PQTs were analyzed by Fourier transform infrared spectroscopy, Ultraviolet–Visible spectroscopy, scanning electron microscope, transmission electron microscopy, and atomic force microscopy, respectively. The PQTs showed a spherical shape with an average size of 100–150 nm. We compared the antibacterial effects of PQTs against Escherichia coli (E. coli) and Micrococcus tetragenus (M. tetragenus).The PQTs produced stronger antibacterial activity to E. coli than that to M. tetragenus through disrupting bacterial cell wall integrity. The antibacterial ratio was increased with the increasing dosages and incubation time. Next, we tested the in vivo antibacterial activity in mice. No noticeable organ damage was captured from H&E-staining organ slices, suggesting the promise of using PQTs for in vivo applications. The results of this study demonstrated the interaction between bacteria and PLGA-based nanoparticles, providing encouragement for conducting further investigations on properties and antimicrobial activity of the PQTs in clinical application.

  13. Quercetin-loaded PLGA nanoparticles: a highly effective antibacterial agent in vitro and anti-infection application in vivo

    Science.gov (United States)

    Sun, Dongdong; Li, Nuan; Zhang, Weiwei; Yang, Endong; Mou, Zhipeng; Zhao, Zhiwei; Liu, Haiping; Wang, Weiyun

    2016-01-01

    Nanotechnology-based approaches have tremendous potential for enhancing efficacy against infectious diseases. PLGA-based nanoparticles as drug delivery carrier have shown promising potential, owing to their sizes and related unique properties. This article aims to develop nanosized poly ( d, l-lactide-co-glycolide) PLGA nanoparticle formulation loaded with quercetin (QT). QT is an antioxidant and antibacterial compound isolated from Chinese traditional medicine with low skin permeability and extreme water insolubility. The quercetin-loaded PLGA nanoparticles (PQTs) were synthesized by emulsion-solvent evaporation method and stabilized by coating with poly (vinyl alcohol). The characteristics of PQTs were analyzed by Fourier transform infrared spectroscopy, Ultraviolet-Visible spectroscopy, scanning electron microscope, transmission electron microscopy, and atomic force microscopy, respectively. The PQTs showed a spherical shape with an average size of 100-150 nm. We compared the antibacterial effects of PQTs against Escherichia coli ( E. coli) and Micrococcus tetragenus ( M. tetragenus).The PQTs produced stronger antibacterial activity to E. coli than that to M. tetragenus through disrupting bacterial cell wall integrity. The antibacterial ratio was increased with the increasing dosages and incubation time. Next, we tested the in vivo antibacterial activity in mice. No noticeable organ damage was captured from H&E-staining organ slices, suggesting the promise of using PQTs for in vivo applications. The results of this study demonstrated the interaction between bacteria and PLGA-based nanoparticles, providing encouragement for conducting further investigations on properties and antimicrobial activity of the PQTs in clinical application.

  14. Quercetin-loaded PLGA nanoparticles: a highly effective antibacterial agent in vitro and anti-infection application in vivo

    International Nuclear Information System (INIS)

    Sun, Dongdong; Li, Nuan; Zhang, Weiwei; Yang, Endong; Mou, Zhipeng; Zhao, Zhiwei; Liu, Haiping; Wang, Weiyun

    2016-01-01

    Nanotechnology-based approaches have tremendous potential for enhancing efficacy against infectious diseases. PLGA-based nanoparticles as drug delivery carrier have shown promising potential, owing to their sizes and related unique properties. This article aims to develop nanosized poly (d, l-lactide-co-glycolide) PLGA nanoparticle formulation loaded with quercetin (QT). QT is an antioxidant and antibacterial compound isolated from Chinese traditional medicine with low skin permeability and extreme water insolubility. The quercetin-loaded PLGA nanoparticles (PQTs) were synthesized by emulsion–solvent evaporation method and stabilized by coating with poly (vinyl alcohol). The characteristics of PQTs were analyzed by Fourier transform infrared spectroscopy, Ultraviolet–Visible spectroscopy, scanning electron microscope, transmission electron microscopy, and atomic force microscopy, respectively. The PQTs showed a spherical shape with an average size of 100–150 nm. We compared the antibacterial effects of PQTs against Escherichia coli (E. coli) and Micrococcus tetragenus (M. tetragenus).The PQTs produced stronger antibacterial activity to E. coli than that to M. tetragenus through disrupting bacterial cell wall integrity. The antibacterial ratio was increased with the increasing dosages and incubation time. Next, we tested the in vivo antibacterial activity in mice. No noticeable organ damage was captured from H&E-staining organ slices, suggesting the promise of using PQTs for in vivo applications. The results of this study demonstrated the interaction between bacteria and PLGA-based nanoparticles, providing encouragement for conducting further investigations on properties and antimicrobial activity of the PQTs in clinical application

  15. Introducing a Semi-Coated Model to Investigate Antibacterial Effects of Biocompatible Polymers on Titanium Surfaces

    Directory of Open Access Journals (Sweden)

    Andreas Winkel

    2015-02-01

    Full Text Available Peri-implant infections from bacterial biofilms on artificial surfaces are a common threat to all medical implants. They are a handicap for the patient and can lead to implant failure or even life-threatening complications. New implant surfaces have to be developed to reduce biofilm formation and to improve the long-term prognosis of medical implants. The aim of this study was (1 to develop a new method to test the antibacterial efficacy of implant surfaces by direct surface contact and (2 to elucidate whether an innovative antimicrobial copolymer coating of 4-vinyl-N-hexylpyridinium bromide and dimethyl(2-methacryloyloxyethyl phosphonate (VP:DMMEP 30:70 on titanium is able to reduce the attachment of bacteria prevalent in peri-implant infections. With a new in vitro model with semi-coated titanium discs, we were able to show a dramatic reduction in the adhesion of various pathogenic bacteria (Streptococcus sanguinis, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, completely independently of effects caused by soluble materials. In contrast, soft tissue cells (human gingival or dermis fibroblasts were less affected by the same coating, despite a moderate reduction in initial adhesion of gingival fibroblasts. These data confirm the hypothesis that VP:DMMEP 30:70 is a promising antibacterial copolymer that may be of use in several clinical applications.

  16. Effect of Silver Nanoparticles on Physicochemical and Antibacterial Properties of Calcium Silicate Cements.

    Science.gov (United States)

    Vazquez-Garcia, Fernando; Tanomaru-Filho, Mário; Chávez-Andrade, Gisselle Moraima; Bosso-Martelo, Roberta; Basso-Bernardi, Maria Inês; Guerreiro-Tanomaru, Juliane Maria

    2016-01-01

    Mineral trioxide aggregate (MTA) and Portland cement (PC) are calcium silicate cements. They have similar physicochemical, mechanical and biological properties. The addition of zirconium oxide (ZrO2) to PC provides radiopacity. Silver nanoparticles (AgNPs) may improve some properties of cements. The aim of this study was to evaluate the effect of AgNPs on physicochemical/mechanical properties and antibacterial activity of white MTA (WMTA) and PC associated with ZrO2. The following materials were evaluated: WMTA; PC 70% + ZrO2 30%; WMTA+ AgNPs; and PC 70% + ZrO2 30% + AgNPs. The study evaluated radiopacity, setting time, pH, compressive strength and solubility. For radiopacity analysis, radiographs were made alongside an aluminum (Al) step wedge. To evaluate the antibacterial activity, direct contact test was performed on planktonic cells and Enterococcus faecalis biofilm induced on bovine root dentin for 14 days. The experimental periods were 5 and 15 h. Data were obtained as CFU mL-1. The obtained data were submitted to ANOVA and Tukey tests (pcalcium silicate cements and favored the physicochemical and mechanical properties of the materials.

  17. Introducing a Semi-Coated Model to Investigate Antibacterial Effects of Biocompatible Polymers on Titanium Surfaces

    Science.gov (United States)

    Winkel, Andreas; Dempwolf, Wibke; Gellermann, Eva; Sluszniak, Magdalena; Grade, Sebastian; Heuer, Wieland; Eisenburger, Michael; Menzel, Henning; Stiesch, Meike

    2015-01-01

    Peri-implant infections from bacterial biofilms on artificial surfaces are a common threat to all medical implants. They are a handicap for the patient and can lead to implant failure or even life-threatening complications. New implant surfaces have to be developed to reduce biofilm formation and to improve the long-term prognosis of medical implants. The aim of this study was (1) to develop a new method to test the antibacterial efficacy of implant surfaces by direct surface contact and (2) to elucidate whether an innovative antimicrobial copolymer coating of 4-vinyl-N-hexylpyridinium bromide and dimethyl(2-methacryloyloxyethyl) phosphonate (VP:DMMEP 30:70) on titanium is able to reduce the attachment of bacteria prevalent in peri-implant infections. With a new in vitro model with semi-coated titanium discs, we were able to show a dramatic reduction in the adhesion of various pathogenic bacteria (Streptococcus sanguinis, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis), completely independently of effects caused by soluble materials. In contrast, soft tissue cells (human gingival or dermis fibroblasts) were less affected by the same coating, despite a moderate reduction in initial adhesion of gingival fibroblasts. These data confirm the hypothesis that VP:DMMEP 30:70 is a promising antibacterial copolymer that may be of use in several clinical applications. PMID:25690041

  18. Effect of random charge fluctuation on strongly coupled dusty Plasma

    Science.gov (United States)

    Issaad, M.; Rouiguia, L.; Djebli, M.

    2008-09-01

    Modeling the interaction between particles is an open issue in dusty plasma. We dealt with strongly coupled dust particles in two dimensional confined system. For small number of clusters, we investigate the effect of random charge fluctuation on background configuration. The study is conducted for a short rang as well as a long rang potential interaction. Numerical simulation is performed using Monte-Carlo simulation in the presence of parabolic confinement and at low temperature. We have studied the background configurations for a dust particles with constant charge and in the presence of random charge fluctuation due to the discrete nature of charge carriers. The latter is studied for a positively charged dust when the dominant charging process is due to photo-emission from the dust surface. It is found, for small classical cluster consisting of small number of particles, short rang potential gives the same result as long rang one. It is also found that the random charge fluctuation affect the background configurations.

  19. Effect of Ti(+4) on in vitro bioactivity and antibacterial activity of silicate glass-ceramics.

    Science.gov (United States)

    Riaz, Madeeha; Zia, Rehana; Saleemi, Farhat; Hussain, Tousif; Bashir, Farooq; Ikhram, Hafeez

    2016-12-01

    A novel glass-ceramic series in (48-x) SiO2-36 CaO-4 P2O5-12 Na2O-xTiO2 (where x=0, 3.5, 7, 10.5 and 14mol %) system was synthesized by crystallization of glass powders, obtained by melt quenching technique. The differential scanning calorimetric analysis (DSC) was used to study the non-isothermal crystallization kinetics of the as prepared glasses. The crystallization behaviour of glasses was analyzed under non-isothermal conditions, and qualitative phase analysis of glass-ceramics was made by X-ray diffraction. The in vitro bioactivity of synthesized glass-ceramics was studied in stimulated body fluid at 37°C under static condition for 24days. The formation of hydroxyl-carbonated apatite layer; evident of bioactivity of the material, was elucidated by XRD, FTIR, AAS, SEM and EDX analysis. The result showed that partial substitution of TiO2 with SiO2 negatively influenced bioactivity; it decreased with increase in concentration of TiO2. As Ti(+4) having stronger field strength as compared to Si(+4) so its replacement became the cause for reduction in degradation that in turn improved the chemical stability. The compressive strength was also enhanced with progress addition of TiO2 in the system. The antibacterial properties were examined against Staphylococcus Epidermidis. Strong antibacterial efficacy was observed with the addition of TiO2 in the system. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Effect of fiber insertion depth on antibacterial efficacy of photodynamic therapy against Enterococcus faecalis in rootcanals.

    Science.gov (United States)

    Rödig, Tina; Endres, Sarah; Konietschke, Frank; Zimmermann, Ortrud; Sydow, Hans Georg; Wiegand, Annette

    2017-06-01

    This in vitro study evaluated the effect of fiber insertion depth on antimicrobial efficacy of antimicrobial photodynamic therapy (aPDT) using a photosensitizer (PS; toluidine blue) and a red light-emitting diode (LED) in root canals infected with Enterococcus faecalis. Single-rooted extracted teeth were prepared with nickel-titanium-instruments, sterilized, contaminated with E. faecalis, and incubated for 72 h. Roots were randomly divided into four experimental groups: PS only, LED only, aPDT with LED in the apical third, aPDT with LED in the coronal third, as well as into infection and sterile controls (each n = 10). Samples were taken by collecting standardized dentine shavings from the root canal walls. After serial dilution and culturing on blood agar, colony-forming units (CFU) were counted. Both aPDT groups showed a CFU reduction of 1-2 log 10 steps compared with the infection control, whereas the effect of fiber insertion depth was negligible (<0.5 log 10 steps). CFU reduction of approximately 0.5 log 10 steps for PS alone was detected compared with the infection control, but PS alone was less effective than both aPDT groups. No antibacterial effect was detected for LED alone. aPDT reduced E. faecalis within the root canal, whereas fiber insertion depth had a negligible influence on antimicrobial effectiveness of aPDT. The insertion depth of the light-emitting diode may not influence the antibacterial efficacy of photodynamic therapy against E. faecalis in straight root canals.

  1. Nano polyamidoamine-G7 dendrimer synthesis and assessment the antibacterial effect in vitro

    Directory of Open Access Journals (Sweden)

    Mitra Gholami

    2016-04-01

    Full Text Available Background: Nano scale dendrimers are macromolecules synthetic which frequently used in medical and health field. Because traditional antibiotics inevitably induce bacterial resistance, which is responsible for many treatment failures, there is an urgent need to develop novel antibiotic drugs. This study was aimed to examine Synthesis and the antibacterial effect of NanoPolyamidoamine-G7 (NPAMAM-G7 dendrimer on Escherichia Coli, Proteus Mirabilis, Salmonella Typhi, Bacillus Subtilis and Staphylococcus Aureus. Methods: In this experimental study that has been conducted in June 2015 in the Laboratory of Microbiology, Iran University of Medical Science, NPAMAM-G7 dendrimers was synthesized by Tomalia’s divergent growth approach. The antibacterial effects of NPAMAM-G7 dendrimer were studied by disc diffusion and micro-dilution method. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC against gram-positive and gram-negative bacteria were determined according to Clinical and Laboratory Standards Institute (CLSI guideline. Standard discs were prepared using different concentrations of dendrimer on Mueller-Hinton agar plates. Results: Zone of inhibition in concentration 25 μg/ml of NPAMAM-G7 dendrimers for Escherichia Coli, Proteus Mirabilis, Salmonella Typhi, Bacillus Subtilis and Staphylococcus Aureus were 26, 38, 36, 22 and 25 mm, respectively. Regarding the zone of inhibition in gram negative bacteria with gram positive ones was P= 0.16 and was not significant difference. The MIC for Salmonella Typhi was 0.025, for Proteus Mirabilis, Bacillus Subtilis, Staphylococcus Aureus and Escherichia Coli was 0.25 μg/ml. The MBC for Salmonella Typhi was 25μg/ml, for Proteus Mirabilis and Bacillus Subtilis was 50 μg/ml and for Escherichia Coli and Staphylococcus Aureus was 100 μg/ml. The least of sensitivity against NPAMAM-G7 related to Escherichia Coli and Staphylococcus Aureus and the most of sensitivity related to

  2. Synthesis of silver nanoparticles using flavonoids: hesperidin, naringin and diosmin, and their antibacterial effects and cytotoxicity

    Science.gov (United States)

    Sahu, Nidhi; Soni, Deepika; Chandrashekhar, B.; Satpute, D. B.; Saravanadevi, Sivanesan; Sarangi, B. K.; Pandey, R. A.

    2016-07-01

    Three different flavonoids -hesperidin, naringin and diosmin (constituents of citrus plants) were used for the synthesis of silver nanoparticles (AgNPs). Aqueous solutions of pure flavonoids (0.2 mg mL-1) mixed with 1 mM AgNO3 solution were exposed to bright sunlight to prepare the nanoparticles. Characterization of the synthesized nanoparticles by UV-Visible spectrophotometer, X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy revealed that the synthesized silver nanoparticles were 10-80 nm in size and polydispersed in nature. Bactericidal effect against common pathogens and cytotoxicity of the synthesized silver nanoparticles was investigated on human promyelocytic leukemic (HL-60) cells. It is concluded that AgNPs synthesized using Naringin as reducing agent showed higher stability and better antibacterial and cytotoxic activities.

  3. Certain relativistic effects due to strong electromagnetic fields in plasmas

    International Nuclear Information System (INIS)

    Tsintsadze, N.L.

    1974-01-01

    It is shown that the propagation of a strong electromagnetic wave in an electron plasma can lead to a generation of a constant electron current along the direction of propagation and to a large increase in the average electron density. (Auth.)

  4. Antibacterial properties of modified biodegradable PHB non-woven fabric.

    Science.gov (United States)

    Slepička, P; Malá, Z; Rimpelová, S; Švorčík, V

    2016-08-01

    The antibacterial properties of poly(hydroxybutyrate) (PHB) non-woven fabric were explored in this study. The PHB was activated by plasma modification and subsequently processed with either immersion into a solution of nanoparticles or direct metallization. The wettability and surface chemistry of the PHB surface was determined. The thickness of the sputtered nanolayer on PHB fabric was characterized. It was found that plasma modification led to a formation of strongly hydrophilic surface, while the subsequent metallization by silver or gold resulted in a significantly increased water contact angle. Further, it was found that antibacterial activity may be controlled by the type of a metal and deposition method used. The immersion of plasma modified fabric into Ag nanoparticle solution led to enhanced antibacterial efficiency of PHB against Escherichia coli (E. coli). Direct silver sputtering on PHB fabric was proved to be a simple method for construction of a surface with strong antibacterial potency against both Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis). We demonstrated the antibacterial activity of PHB fabric modified by plasma activation and consecutive selection of a treatment method for an effective antibacterial surface construction. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. THE ANTIBACTERIAL EFFECT OF ROSELLE (HIBISCUS SABDARIFFA EXTRACT AGAINST STAPHYLOCOCCUS EPIDERMIDIS IN VITRO

    Directory of Open Access Journals (Sweden)

    Terrence Timothy Evan Lusida

    2017-04-01

    Full Text Available Infection of Staphylococcus epidermidis is still a common problem in many hospitals. Factor determining biofilm formation makes it harder for atibiotics to cure the infection. Roselle (Hibiscus sabdariffa, a well known traditional medicine plant, is a potential candidate as a drug againts infectious disease. The purpose of this research is to investigate the antibacterial effect of ethanol extract from Roselle (Hibiscus sabdariffa calyx againts the growth of Staphylococcus epidermidis. Assessment for antibacterial effect is performed using broth diffusion method. The extract is made by maceration of the calyx of Roselle in 96% ethanol. Extracts with concentration of 125, 62.5, 31.25, 15.63, 7.81, 3.90, 1.95, 0.97, 0.48, 0.24 mg/mL are added into separated Mueller-Hinton broths (MHB, which have already been inoculated by Staphylococcus epidermidis. As for bacterial growth control, we used MHB with bacterial inoculation, while sterility control we used mixture of extract and MHB. Then from each broth, the solutions are added into separated nutrition agar plates. Replications are done three times. Clarity and bacterial growth are observed after 24 hours of incubation. However, clarity cannot be observed in 36 broth, but bacterial growth is observed on the plate for concentration 0.97, 0.48, and 0.24 mg/mL. Therefore Minimum inhibitory concentration (MIC cannot be determined because the extract’s color interfere the observation. While minimum bactericidal concentration (MBC, the last concentration before the concentration where the bacteria are still viable, is 1.95 mg/mL. Based on the result of the research, the Roselle calyx ethanol extract (Hibiscus sabdariffa through dilution method with a concentration of 1.95 mg / mL can kill Staphylococcus epidermidis and in order to find MIC in collored and turbid solution (before being incubated in incubator, we can consider using agar dilution methode or microdilution methode.

  6. Chemical Composition, in Vitro Antibacterial and Cytotoxicity Effect of Nectaroscordum tripedale Extract

    Directory of Open Access Journals (Sweden)

    Behrouz Ezatpour

    2016-12-01

    Full Text Available Background and Aim: The present study investigated the antimicrobial, and cytotoxic activities of the methanol extract of Nectaroscordum tripedale leaves. Materials and Methods: Methanolic extract of Nectaroscordum tripedale was investigated for its phytochemical components, antimicrobial activity and cytotoxicity. The antibacterial potentialities of methanol extract of Nectaroscordum tripedale leaves were investigated by the disc diffusion and broth dilution method against five bacterial isolates including three food-borne pathogens (Staphylococcus aureus, Listeria monocytogenes and Escherichia coli and two healthcare-associated pathogens (Methicillin resistance Staphylococcus and Pseudomonas aeruginosa and cytotoxicity activity were evaluated on acute myeloid leukemia cell line (KG-1a and normal lymphocyte cells and  the effect of Nectaroscordum tripedale extract and methotrexate in 0.01, 0.1, 1, and 2 mg/ml concentrations on these cells were compared. Results: The extract was found to contain 27 chemical compounds. The maximum zone of inhibition was observed in Methicillin Resistant Staphylococcus aureus (MRSA. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of Nectaroscordum tripedale for E. coli and MSRA were similar (166 and 322 µg/ml, respectively. While the high level of MIC and MBC is related to Pseudomonas aeruginosa. The percentage of lysis for extract and methotrexate on the KG-1a was seen after 24 hours. Conclusions: In comparison with methotrexate, Nectaroscordum tripedale had minimal effect on normal cells. The present study revealed that the methanol extract of Nectaroscordum tripedale leaves has significant antibacterial activities along with moderate cytotoxicity's on the cancer cells that may lead to new drug development.

  7. Antibacterial effects of Arctium lappa and Artemesia absinthium extracts in laboratory conditions

    Directory of Open Access Journals (Sweden)

    Habibipour Reza

    2015-10-01

    Full Text Available Introduction: Arctium lappa (Great burduck and Artemesia absinthium are medicinal plants that some of their antibacterial and antivirus properties have been suggested in nutritional industries. The objective of this research was to study the effects of A. lappa and A. absinthium on some microorganisms including Pseudomonads aeraginosa, Haemophilus influenza, Bacillus subtilis, Bacillus cereus, Klebsiella pneumonia and Staphylococcus aureus. Methods: Extracts were prepared by maceration method and tested on Mueller Hinton agar medium based on disc diffusion method. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined by micro-dilution method. Antibiotic disks used for controlling and standardizing the examination. Results: The extracts of A. lappa and A. absinthium had significant effect on S. aureus. The MIC and MBC concentrations of the extract of A. lappa on B. subtilis were respectively 600 and 750 mg/ml. Also, these values were 230 and 540 mg/ml for H. influenza. Extract of A. absinthium showed more inhibitory effect on B. subtilis. All extracts showed inhibitory effect on B. cereus. The extracts of A. lappa and A. absinthium had inhibitory effects on H. influenza and P. aeraginosa. Among antibiotics, only Ofloxacin and Ciprofloxacin had effects on H. influenza. Extract of A. lappa showed flimsy effect on K. pneumonia, while extract of A. absinthium had no effect on this bacterium. Conclusion: Due to the effects of A. lappa and A. absinthium on some bacteria, they might be good substitutes for synthetic substances.

  8. [Characterization and antibacterial effect of Ag-nHA-nTiO2/polyamide 66 nanocomposite membrane on oral bacteria].

    Science.gov (United States)

    Bai, Shi; Mo, An-chun; Xian, Su-qin; Zuo, Yi; Li, Yu-bao; Xu, Wei

    2008-08-01

    Undried silver-hydroxyapatite-titania (Ag-nHA-nTiO2) nanoparticles slurry was used to make membrane with polyamide 66 (PA66) by co-polymerization method. The purpose of this study is to test the physical and chemical characteristics and antibacterial ability. The morphology, chemical components and structures of the membrane were characterized by atomic absorption spectrometer (AAS), X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive X-ray analysis (EDX). Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Porphyromonas gingivalis (P. gingivalis), Fusobacterium nucleatum (F. nucleatum) and Streptococcus mutans (S. mutans) were utilized to test the antibacterial effect. XRD results demonstrated that the membrane have characteristic diffraction peaks of pure hydroxyapatite (HA). A homogeneous distribution of the Ca, P, Ti and Ag element in the membrane was confirmed by EDX. Both surface and section showed porous structure which was confirmed by SEM and the average hole size was 20-30 microm. The bacteria assay reflected to the antibacterial effect, 50.10% of S. aureus and 56.31% of E. coli were killed. However, 91.84% of P. gingivalis, 90.64% of F. nucleatum and 90.49% of S. mutans were killed and pictures of SEM showed obviously fewer cells on the surface. The nanocomposite membrane could be one of the bioactive materials with antibacterial properties for oral guided bone regeneration technique.

  9. Effect of copper addition on mechanical properties, corrosion resistance and antibacterial property of 316L stainless steel.

    Science.gov (United States)

    Xi, Tong; Shahzad, M Babar; Xu, Dake; Sun, Ziqing; Zhao, Jinlong; Yang, Chunguang; Qi, Min; Yang, Ke

    2017-02-01

    The effects of addition of different Cu content (0, 2.5 and 3.5wt%) on mechanical properties, corrosion resistance and antibacterial performance of 316L austenitic stainless steel (SS) after solution and aging treatment were investigated by mechanical test, transmission electron microscope (TEM), X-ray diffraction (XRD), electrochemical corrosion, X-ray photoelectron spectroscopy (XPS) and antibacterial test. The results showed that the Cu addition and heat treatment had no obvious influence on the microstructure with complete austenite features. The yield strength (YS) after solution treatment was almost similar, whereas the aging treatment obviously increased the YS due to formation of tiny Cu-rich precipitates. The pitting and protective potential of the solution treated Cu-bearing 316L SS in 0.9wt% NaCl solution increased with increasing Cu content, while gradually declined after aging, owing to the high density Cu-rich precipitation. The antibacterial test proved that higher Cu content and aging were two compulsory processes to exert good antibacterial performance. The XPS results further indicated that aging enhanced the Cu enrichment in passive film, which could effectively stimulate the Cu ions release from the surface of passive film. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Effective Field Theories and Strong Interactions. Final Technical Report

    International Nuclear Information System (INIS)

    Fleming, Sean

    2011-01-01

    The framework of Effective Field Theories (EFTs) allows us to describe strong interactions in terms of degrees of freedom relevant to the energy regimes of interest, in the most general way consistent with the symmetries of QCD. Observables are expanded systematically in powers of M lo /M hi , where M lo (M hi ) denotes a low-(high-)energy scale. This organizational principle is referred to as 'power counting'. Terms of increasing powers in the expansion parameter are referred to as leading order (LO), next-to-leading order (NLO), etc. Details of the QCD dynamics not included explicitly are encoded in interaction parameters, or 'low-energy constants' (LECs), which can in principle be calculated from an explicit solution of QCD - for example via lattice simulations- but can also be determined directly from experimental data. QCD has an intrinsic scale M QCD ≅ 1 GeV, at which the QCD coupling constant α s (M QCD ) becomes large and the dynamics becomes non-perturbative. As a consequence M QCD sets the scale for the masses of most hadrons, such as the nucleon mass m N ≅ 940 MeV. EFTs can roughly be divided into two categories: those that can be matched onto QCD in perturbation theory, which we call high-energy EFTs, and those that cannot be matched perturbatively, which we call low-energy EFTs. In high-energy EFTs, M QCD typically sets the low-energy scale, and all the dynamics associated with this scale reside in matrix elements of EFT operators. These non-perturbative matrix elements are the LECs and are also referred to as long-distance contributions. Each matrix element is multiplied by a short-distance coefficient, which contains the dynamics from the high scale M hi . Since M hi >> M QCD , α s (M hi ) hi ∼ M Q , the heavy-quark mass, and in addition to M QCD there are low scales associated with the typical relative momentum ∼ M Q v and energy ∼ M Q v 2 of the heavy quarks. Depending on the sizes of M Q and the heavy-quark velocity v these scales can

  11. How strong and generalisable is the Generation Y effect?

    DEFF Research Database (Denmark)

    Mueller, Simone; Remaud, Hervé; Chabin, Yann

    2011-01-01

    alcoholic beverage consumption. A number of noticeable differences appeared between countries: wine involvement and consumption increases with age in traditional European wine markets, while they decrease in North America; environmental concerns and purchase channel usage hardly differ between generations......Purpose – This study aims to investigate how strongly Generation Y consumers differ in their values, attitudes and wine and alcoholic beverage consumption behaviour from older generations. The comparison spans seven culturally different markets. Design/methodology/approach – Large representative...

  12. Synergistic antibacterial effect of curcumin against methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Mun, Su-Hyun; Joung, Dae-Ki; Kim, Yong-Sik; Kang, Ok-Hwa; Kim, Sung-Bae; Seo, Yun-Soo; Kim, Youn-Chul; Lee, Dong-Sung; Shin, Dong-Won; Kweon, Kee-Tae; Kwon, Dong-Yeul

    2013-06-15

    Methicillin-resistant Staphylococcus aureus (MRSA) are spread among infected patients, with infection rates increasing at an alarming rate. Furthermore, increased resistance to antibiotics has resulted in serious challenges in the treatment of infectious diseases worldwide. Under the selection pressure of exposure to antibiotics, microorganisms evolve to survive against the new conditions imposed by therapy. Therefore, there exists a need to develop alternative natural or combination drug therapies. Curcumin (CCM), a natural polyphenolic flavonoid isolated from the rhizome of a plant, Curcuma longa Linné., has been found to possess many beneficial biological activities. The aim of this study was to investigate the synergistic effect of curcumin and antibiotics as well as to determine the antibacterial activity of CCM against specific MRSA strains. The antibacterial activity of CCM was assessed by the broth microdilution method (by calculating the minimal inhibitory concentration [MIC]), checkerboard dilution test, and time-kill assay. Antimicrobial activity of CCM was observed against all tested strains. The MICs of CCM against 10 strains of S. aureus ranged from 125 to 250 μg/ml. In the checkerboard test, CCM markedly reduced the MICs of the antibiotics oxacillin (OXI), ampicillin (AMP), ciprofloxacin (CIP), and norfloxacin (NOR) used against MRSA. The time-kill curves showed that a combined CCM and OXI treatment reduced the bacterial counts below the lowest detectable limit after 24h. This study suggested that CCM reduced the MICs of several antibiotics tested, notably of OXI, AMP, CIP, and NOR, and that CCM in combination with antibiotics could lead to the development of new combination of antibiotics against MRSA infection. Copyright © 2013. Published by Elsevier GmbH.

  13. Evaluation of the antibacterial effects of vancomycin hydrochloride released from agar–gelatin–bioactive glass composites

    International Nuclear Information System (INIS)

    Rivadeneira, Josefina; Gorustovich, Alejandro A; Di Virgilio, Ana Laura; Audisio, M Carina; Boccaccini, Aldo R

    2015-01-01

    The aim of this work was to evaluate the perfomance of agar–gelatin (AG) composites and AG-containing 45S5 bioactive glass (BG) microparticles (AGBG) in relation to their water uptake capacity, sustained release of a drug over time, and antibacterial effects. The composites were fabricated by the gel-casting method. To impart the local drug release capacity, vancomycin hydrochloride (VC) was loaded in the composites in concentrations of 0.5 and 1 mg ml −1 . VC release was assessed in distilled water at 37 °C up to 72 h and quantified spectrophotometrically. The antibacterial activity of composites was evaluated by the inhibition zone test and the plate count method. The experiments were performed in vitro up to 48 h on three staphylococcus strains: Staphylococcus aureus ATCC29213, S. aureus ATCC6538 and Staphylococcus epidermidis ATCC12228. The results showed that the addition of BG to AG composites did not affect the degree of water uptake. The release of VC was significantly affected by the presence of BG. VC release was higher from AGBGVC films than from AGVC ones over prolonged incubation times. Bacterial inhibition zones were found around the composites. The halos were larger when the cells were put in contact with AGVC composites than when they were put in contact with AGBGVC ones. Nevertheless, the viable count method demonstrated that the composites inhibited Staphylococcus cell growth with no statistical differences. In conclusion, the addition of BG did not reflect an improvement in the parameters studied. On the other hand, composites loaded with VC would have a role in prophylaxis against bacterial infection. (paper)

  14. Antibacterial effect of Allium sativum cloves and Zingiber officinale rhizomes against multiple-drug resistant clinical pathogens.

    Science.gov (United States)

    Karuppiah, Ponmurugan; Rajaram, Shyamkumar

    2012-08-01

    To evaluate the antibacterial properties of Allium sativum (garlic) cloves and Zingiber officinale (ginger) rhizomes against multi-drug resistant clinical pathogens causing nosocomial infection. The cloves of garlic and rhizomes of ginger were extracted with 95% (v/v) ethanol. The ethanolic extracts were subjected to antibacterial sensitivity test against clinical pathogens. Anti-bacterial potentials of the extracts of two crude garlic cloves and ginger rhizomes were tested against five gram negative and two gram positive multi-drug resistant bacteria isolates. All the bacterial isolates were susceptible to crude extracts of both plants extracts. Except Enterobacter sp. and Klebsiella sp., all other isolates were susceptible when subjected to ethanolic extracts of garlic and ginger. The highest inhibition zone was observed with garlic (19.45 mm) against Pseudomonas aeruginosa (P. aeruginosa). The minimal inhibitory concentration was as low as 67.00 µg/mL against P. aeruginosa. Natural spices of garlic and ginger possess effective anti-bacterial activity against multi-drug clinical pathogens and can be used for prevention of drug resistant microbial diseases and further evaluation is necessary.

  15. Antibacterial Effect of Copaifera duckei Dwyer Oleoresin and Its Main Diterpenes against Oral Pathogens and Their Cytotoxic Effect

    Science.gov (United States)

    Abrão, Fariza; Alves, Jessica A.; Andrade, Gessica; de Oliveira, Pollyanna F.; Ambrósio, Sérgio R.; Veneziani, Rodrigo C. S.; Tavares, Denise C.; Bastos, Jairo K.; Martins, Carlos H. G.

    2018-01-01

    This study evaluates the antibacterial activity of the Copaifera duckei Dwyer oleoresin and two isolated compounds [eperu-8(20)-15,18-dioic acid and polyalthic acid] against bacteria involved in primary endodontic infections and dental caries and assesses the cytotoxic effect of these substances against a normal cell line. MIC and MBC assays pointed out the most promising metabolites for further studies on bactericidal kinetics, antibiofilm activity, and synergistic antibacterial action. The oleoresin and polyalthic acid but not eperu-8(20)-15,18-dioic provided encouraging MIC and MBC results at concentrations lower than 100 μg mL−1. The oleoresin and polyalthic acid activities depended on the evaluated strain. A bactericidal effect on Lactobacillus casei (ATCC 11578 and clinical isolate) emerged before 8 h of incubation. For all the tested bacteria, the oleoresin and polyalthic acid inhibited biofilm formation by at least 50%. The oleoresin and polyalthic acid gave the best activity against Actinomyces naeslundii (ATCC 19039) and L. casei (ATCC 11578), respectively. The synergistic assays combining the oleoresin or polyalthic acid with chlorhexidine did not afford interesting results. We examined the cytotoxicity of C. duckei oleoresin, eperu-8(20)-15,18-dioic acid, and polyalthic acid against Chinese hamster lung fibroblasts. The oleoresin and polyalthic acid were cytotoxic at concentrations above 78.1 μg mL−1, whereas eperu-8(20)-15,18-dioic displayed cytotoxicity at concentrations above 312.5 μg mL−1. In conclusion, the oleoresin and polyalthic acid are potential sources of antibacterial agents against bacteria involved in primary endodontic infections and dental caries in both the sessile and the planktonic modes at concentrations that do not cause cytotoxicity. PMID:29515530

  16. Microstructure, mechanical properties, bio-corrosion properties and antibacterial properties of Ti–Ag sintered alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mian [Key Lab. for Anisotropy and Texture of Materials, Education Ministry of China, Northeastern University, Shenyang 110819 (China); Zhang, Erlin, E-mail: zhangel@atm.neu.edu.cn [Key Lab. for Anisotropy and Texture of Materials, Education Ministry of China, Northeastern University, Shenyang 110819 (China); Zhang, Lan [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China)

    2016-05-01

    In this research, Ag element was selected as an antibacterial agent to develop an antibacterial Ti–Ag alloy by a powder metallurgy. The microstructure, phase constitution, mechanical properties, corrosion resistance and antibacterial properties of the Ti–Ag sintered alloys have been systematically studied by X-ray diffraction (XRD), scanning electron microscope (SEM), compressive test, electrochemical measurements and antibacterial test. The effects of the Ag powder size and the Ag content on the antibacterial property and mechanical property as well as the anticorrosion property have been investigated. The microstructure results have shown that Ti–Ag phase, residual pure Ag and Ti were the mainly phases in Ti–Ag(S75) sintered alloy while Ti{sub 2}Ag was synthesized in Ti–Ag(S10) sintered alloy. The mechanical test indicated that Ti–Ag sintered alloy showed a much higher hardness and the compressive yield strength than cp-Ti but the mechanical properties were slightly reduced with the increase of Ag content. Electrochemical results showed that Ag powder size had a significant effect on the corrosion resistance of Ti–Ag sintered alloy. Ag content increased the corrosion resistance in a dose dependent way under a homogeneous microstructure. Antibacterial tests have demonstrated that antibacterial Ti–Ag alloy was successfully prepared. It was also shown that the Ag powder particle size and the Ag content influenced the antibacterial activity seriously. The reduction in the Ag powder size was benefit to the improvement in the antibacterial property and the Ag content has to be at least 3 wt.% in order to obtain a strong and stable antibacterial activity against Staphylococcus aureus bacteria. The bacterial mechanism was thought to be related to the Ti{sub 2}Ag and its distribution. - Highlights: • Ti–Ag alloy with up to 99% antibacterial rate was developed by powder metallurgy. • The effects of the Ag powder size and the Ag content on the

  17. Photodynamic therapy for inactivating endodontic bacterial biofilms and effect of tissue inhibitors on antibacterial efficacy

    Science.gov (United States)

    Shrestha, Annie; Kishen, Anil

    Complex nature of bacterial cell membrane and structure of biofilm has challenged the efficacy of antimicrobial photodynamic therapy (APDT) to achieve effective disinfection of infected root canals. In addition, tissue-inhibitors present inside the root canals are known to affect APDT activity. This study was aimed to assess the effect of APDT on bacterial biofilms and evaluate the effect of tissue-inhibitors on the APDT. Rose-bengal (RB) and methylene-blue (MB) were tested on Enterococcus faecalis (gram-positive) and Pseudomonas aeruginosa (gram-negative) biofilms. In vitro 7- day old biofilms were sensitized with RB and MB, and photodynamically activated with 20-60 J/cm2. Photosensitizers were pre-treated with different tissue-inhibitors (dentin, dentin-matrix, pulp tissue, bacterial lipopolysaccharides (LPS), and bovine serum albumin (BSA)) and tested for antibacterial effect of APDT. Microbiological culture based analysis was used to analyze the cell viability, while Laser Scanning Confocal Microscopy (LSCM) was used to examine the structure of biofilm. Photoactivation resulted in significant reduction of bacterial biofilms with RB and MB. The structure of biofilm under LSCM was found to be disrupted with reduced biofilm thickness. Complete biofilm elimination could not be achieved with both tested photosensitizers. APDT effect using MB and RB was inhibited in a decreasing order by dentin-matrix, BSA, pulp, dentin and LPS (Pendodontic environment.

  18. Spin effects in strong-field laser-electron interactions

    International Nuclear Information System (INIS)

    Ahrens, S; Bauke, H; Müller, T-O; Villalba-Chávez, S; Müller, C

    2013-01-01

    The electron spin degree of freedom can play a significant role in relativistic scattering processes involving intense laser fields. In this contribution we discuss the influence of the electron spin on (i) Kapitza-Dirac scattering in an x-ray laser field of high intensity, (ii) photo-induced electron-positron pair production in a strong laser wave and (iii) multiphoton electron-positron pair production on an atomic nucleus. We show that in all cases under consideration the electron spin can have a characteristic impact on the process properties and their total probabilities. To this end, spin-resolved calculations based on the Dirac equation in the presence of an intense laser field are performed. The predictions from Dirac theory are also compared with the corresponding results from the Klein-Gordon equation.

  19. Effects of Different Systemic Insecticides in Carotenoid Content, Antibacterial Activity and Morphological Characteristics of Tomato (Solanum lycopersicum var Diamante)

    OpenAIRE

    LEXTER R. NATIVIDAD; Maria Fatima T. Astrero; Lenard T. Basinga; Maria Karysa G. Calang

    2014-01-01

    This study aimed to determine the effects of different systemic insecticides in tomato (Lycopersicon esculentum var. Diamante). The study also assessed different systemic insecticides used in other plants in their effectiveness and suitability to tomato by evaluating the carotenoid content and antibacterial activity of each insecticide. Morphological characteristics such as the weight, the number and the circumference of tomato fruits and the height of the plant were also observed. Moreover, ...

  20. Antibacterial Effect of Curcuma longa (Turmeric) Against Staphylococcus aureus and Escherichia coli.

    Science.gov (United States)

    Afrose, R; Saha, S K; Banu, L A; Ahmed, A U; Shahidullah, A S; Gani, A; Sultana, S; Kabir, M R; Ali, M Y

    2015-07-01

    This observational study was conducted during the period from July 2010 to June 2011 in the Department of Pharmacology in the collaboration of Department of Microbiology, Mymensingh Medical College, Mymensingh to determine the profile of antibacterial effect of Crude Turmeric paste aqueous turmeric extract, and standard antibiotic Amikacin against Staphylococcus aureus and Escherichia coli. Three separate experiments were done e.g. (Expt- I) Inhibitory effect of Crude Turmeric paste incorporated into nutrient agar (NA) media, (Expt- II) Minimum inhibitory concentration of (a) Aqueous Turmeric extract and (b) Amikacin by broth dilution technique and (Expt-III) their subculture study in nutrient agar (NA) media for confirmation of respective results of previous experiments. Inhibitory effects were observed against the growth of Staph Aureus and Esch coli at 10% and 30% respectively of Crude Turmeric paste incorporated into NA media. The broth dilution technique was followed to determine the MIC of Aqueous Turmeric extract and Amikacin. The MIC of Aqueous Turmeric extract was 800 μg/ml against Staph aureus and that against Esch coli was 2000 μg/ml and the MIC of Amikacin was 10 μg/ml for both the bacteria. The MIC of Amikacin was the lowest in comparison to MIC of Aqueous Turmeric extract for complete inhibition of growth of Staph aureus and Esch coli. The subculture study showed similar results with that of previous experiments in terms of inhibitory effects of Crude Turmeric paste and MIC of Aqueous Turmeric extract and Amikacin against all of the organisms studied.

  1. Antibacterial effects and physical properties of glass-ionomer cements containing chlorhexidine for the ART approach.

    NARCIS (Netherlands)

    Takahashi, Y.; Imazato, S.; Kaneshiro, A.V.; Ebisu, S.; Frencken, J.E.F.M.; Tay, F.R.

    2006-01-01

    OBJECTIVES: Since atraumatic restorative treatment (ART) involves removal of carious lesions with manual instruments, improvement of filling materials to guarantee greater success should be considered. This study aimed to evaluate antibacterial, physical, and bonding properties of glass-ionomer

  2. Radiation effects on relativistic electrons in strong external fields

    International Nuclear Information System (INIS)

    Iqbal, Khalid

    2013-01-01

    The effects of radiation of high energy electron beams are a major issue in almost all types of charged particle accelerators. The objective of this thesis is both the analytical and numerical study of radiation effects. Due to its many applications the study of the self force has become a very active and productive field of research. The main part of this thesis is devoted to the study of radiation effects in laser-based plasma accelerators. Analytical models predict the existence of radiation effects. The investigation of radiation reaction show that in laser-based plasma accelerators, the self force effects lower the energy gain and emittance for moderate energies electron beams and increase the relative energy spread. However, for relatively high energy electron beams, the self radiation and retardation (radiation effects of one electron on the other electron of the system) effects increase the transverse emittance of the beam. The energy gain decreases to even lower value and relative energy spread increases to even higher value due to high radiation losses. The second part of this thesis investigates with radiation reaction in focused laser beams. Radiation effects are very weak even for high energy electrons. The radiation-free acceleration and the simple practical setup make direct acceleration in a focused laser beam very attractive. The results presented in this thesis can be helpful for the optimization of future electron acceleration experiments, in particular in the case of laser-plasma accelerators.

  3. Effective magnetic moment of neutrinos in strong magnetic fields

    CERN Document Server

    Pérez, A; Masood, S S; Gaitan, R; Rodríguez, S

    2002-01-01

    In this paper we compute the effective magnetic moment of neutrinos propagating in dense high magnetized medium. Taking typical values of magnetic field and densities of astrophysical objects (such as the cores of supernovae and neutron stars) we obtain an effective type of dipole magnetic moment in agreement with astrophysical and cosmological bounds. (Author)

  4. Preparation and Characterization of Nylon 6/Silver Nanocomposite Fibers for Permanent Antibacterial Effect

    OpenAIRE

    Laleh Maleknia; A. Saeed Rashidi

    2015-01-01

    The nylon 6/silver nano composite fibers were prepared for the attainment of permanent antibacterial activity to common synthetic textile. The fibers prepared by melt spinning and nylon 6/ Silver nanocomposite were prepared by a modular twin screw extruder.. The antibacterial activities of nano silver in fibers were calculated by percent reduction of two kinds of bacteria staphylococcus aurous and klebsiela peneumoniae. Scanning electron microscopy (SEM) was carried out to observe particle di...

  5. PHYSICAL PROPERTIES OF ANTIBACTERIAL TREATED COTTON FABRICS AND EFFECT OF LAUNDRY CYCLE

    Directory of Open Access Journals (Sweden)

    PALAMUTCU Sema

    2014-05-01

    Full Text Available During daily usage of textiles, humidity and warmth conditions provide appropriate living conditions for bacteria and microorganisms in textile products. Bacteria growth, infection and cross infection by pathogens might develop due to usage of textile products. Especially since World War II, antibacterial textile products have developed as a result of the hygiene demand of the society. In this study, triclosan (sample A, quaternary ammonium plus triclosan (sample B, dichlorophenol (sample C, silver (sample D, quaternary ammonium (sample E and chitosan (sample F based six different antibacterial additives were applied on 100% cotton fabrics for antibacterial treatment. All six treated fabrics and the untreated fabric (control sample were washed for 40 cycles; the antibacterial efficacies were tested; changes in tear strength and Berger whiteness values of the samples were recorded prior to washing and after 1st, 5th, 10th, 20th and 40th washing cycles. Regarding all washing cycles, a decrease in tear strength results is observed between unwashed and 40 cycle washed samples. Textile materials such as bedlinen, pillow cases, surgeon gowns for which tear strength values are important and that have antibacterial treatments should be tested for tear strength values for different washing cycles to see if they meet minimum tear strength requirements. The change in tear strength and Berger whiteness of samples shows differences according to the antibacterial agent treated and washing cycle applied. Generally, slight decreases in tear strength values are observed. And slight decreases in whiteness, except for sample F which is treated with chitosan, are observed as well. Textile materials having antibacterial treatments should be tested for the special antibacterial agent they are treated and for the number of washing cycles that is required for their product life.

  6. Antibiofilm and antibacterial effects of specific chitosan molecules on Staphylococcus aureus isolates associated with bovine mastitis

    Science.gov (United States)

    Asli, Abdelhamid; Brouillette, Eric; Ster, Céline; Ghinet, Mariana Gabriela; Brzezinski, Ryszard; Lacasse, Pierre; Jacques, Mario

    2017-01-01

    Staphylococcus aureus is one of the major pathogens causing bovine intramammary infections (IMIs) and mastitis. Mastitis is the primary cause for the use of antibiotics in dairy farms but therapeutic failure is often observed. One of the reasons for the lack of effectiveness of antibiotic therapy despite the observed susceptibility of bacterial isolates in vitro are bacterial biofilms. In this study, we used chitosan of well-defined molecular weight (0.4–0.6, 1.3, 2.6 and 4.0 kDa) and investigated their antibiofilm and antibacterial activities in in vitro and in vivo models related to S. aureus IMIs. A chitosan of at least 6 units of glucosamine was necessary for maximum antibacterial activity. The 2.6 and 4.0 kDa forms were able to prevent biofilm production by the biofilm hyperproducer strain S. aureus 2117 and a bovine MRSA (methicillin-resistant S. aureus). The intramammary administration of the 2.6 kDa chitosan showed no adverse effects in mice or in cows, as opposed to the slight inflammatory effect observed in mammary glands with the 4.0 kDa derivative. The 2.6 kDa chitosan killed bacteria embedded in pre-established biofilms in a dose-dependent manner with a >3 log10 reduction in CFU at 4 mg/ml. Also, the 2.6 kDa chitosan could prevent the persistence of the internalized MRSA into the mammary epithelial cell line MAC-T. An in vitro checkerboard assay showed that the 2.6 kDa chitosan produced a synergy with the macrolide class of antibiotics (e.g., tilmicosin) and reduced the MIC of both molecules by 2–8 times. Finally, the intramammary administration of the 2.6 kDa chitosan alone (P<0.01) or in combination with tilmicosin (P<0.0001) reduced the colonization of mammary glands in a murine IMI model. Our results suggest that the use of chitosan alone or in combination with a low dose of a macrolide could help reduce antibiotic use in dairy farms. PMID:28486482

  7. Antibiofilm and antibacterial effects of specific chitosan molecules on Staphylococcus aureus isolates associated with bovine mastitis.

    Directory of Open Access Journals (Sweden)

    Abdelhamid Asli

    Full Text Available Staphylococcus aureus is one of the major pathogens causing bovine intramammary infections (IMIs and mastitis. Mastitis is the primary cause for the use of antibiotics in dairy farms but therapeutic failure is often observed. One of the reasons for the lack of effectiveness of antibiotic therapy despite the observed susceptibility of bacterial isolates in vitro are bacterial biofilms. In this study, we used chitosan of well-defined molecular weight (0.4-0.6, 1.3, 2.6 and 4.0 kDa and investigated their antibiofilm and antibacterial activities in in vitro and in vivo models related to S. aureus IMIs. A chitosan of at least 6 units of glucosamine was necessary for maximum antibacterial activity. The 2.6 and 4.0 kDa forms were able to prevent biofilm production by the biofilm hyperproducer strain S. aureus 2117 and a bovine MRSA (methicillin-resistant S. aureus. The intramammary administration of the 2.6 kDa chitosan showed no adverse effects in mice or in cows, as opposed to the slight inflammatory effect observed in mammary glands with the 4.0 kDa derivative. The 2.6 kDa chitosan killed bacteria embedded in pre-established biofilms in a dose-dependent manner with a >3 log10 reduction in CFU at 4 mg/ml. Also, the 2.6 kDa chitosan could prevent the persistence of the internalized MRSA into the mammary epithelial cell line MAC-T. An in vitro checkerboard assay showed that the 2.6 kDa chitosan produced a synergy with the macrolide class of antibiotics (e.g., tilmicosin and reduced the MIC of both molecules by 2-8 times. Finally, the intramammary administration of the 2.6 kDa chitosan alone (P<0.01 or in combination with tilmicosin (P<0.0001 reduced the colonization of mammary glands in a murine IMI model. Our results suggest that the use of chitosan alone or in combination with a low dose of a macrolide could help reduce antibiotic use in dairy farms.

  8. The Connect Effect Building Strong Personal, Professional, and Virtual Networks

    CERN Document Server

    Dulworth, Michael

    2008-01-01

    Entrepreneur and executive development expert Mike Dulworth's THE CONNECT EFFECT provides readers with a simple framework and practical tools for developing that crucial competitive advantage: a high-quality personal, professional/organizational and virtual network.

  9. Seasonal variation of Brazilian red propolis: Antibacterial activity, synergistic effect and phytochemical screening.

    Science.gov (United States)

    Regueira, M S; Tintino, Saulo Relison; da Silva, Ana Raquel Pereira; Costa, Maria do Socorro; Boligon, Aline Augusti; Matias, Edinardo F F; de Queiroz Balbino, Valdir; Menezes, Irwin R A; Melo Coutinho, Henrique Douglas

    2017-09-01

    The aim of this study was to investigate the effect of the dry and rainy season on the antibacterial activity and chemical composition of the Brazilian red propolis. The samples were collected in rainy (RP-PER) and dry (RP-PED) seasons and analyzed by HPLC-DAD. The extracts were tested alone and in association with antibiotics against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The HPLC analysis identified luteolin and quercetin as the main compounds. Seasonal variation was observed according to concentrations of the compounds. The MIC values against E. coli ranged from 128 μg/mL to 512 μg/mL (EC 06 and EC ATCC). The red propolis showed MIC values of 512 μg/mL against both strains of P. aeruginosa used in our study (PA03 and PA24) and against strains of Gram-positive bacteria S. aureus the MICs ranged from 64 μg/mL to ≥1024 μg/mL (SA10). A synergistic effect was observed when we combined the RP-PED with gentamicin against all the strains tested. When we combined the RP-PED with Imipenem, we only observed synergistic effect against P. aeruginosa. According to our synergistic activity results, the utilization of red propolis collected in the drier periods can be used as an adjuvant against multiresistant bacterial infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Comparative antibacterial effectiveness of alcohol and herbal based commercially available hand antiseptics

    Directory of Open Access Journals (Sweden)

    K Vipin Jain

    2013-01-01

    Full Text Available Background: Human skin is a reservoir of numerous microorganisms. Even though hand washing with soap and water alone reduces the microbial load, the complementary uses of hand antiseptics enhance the antimicrobial effect. Aim: To compare the antimicrobial effectiveness of two commercially available hand antiseptics, routinely used in dental practice, after hand washing with antiseptic soap. Method: A clinical trial with cross over design was carried out on 12 health care workers (HCWs. The antibacterial effectiveness of two hand antiseptics (Alcohol based -Sterillium and Herbal Based-Himalaya′s ′Pure Hands′ compared using fingerprint contact sampling on blood agar. Bacterial samples were obtained before and after hand washing (with antiseptic soap and after hand disinfection. The data was tabulated and analyzed using one way ANOVA and Tukey′s post hoc test for pair-wise comparison. Result: There was a slight decrease in the Colony forming units (CFUs count following use of antiseptic soap when compared to the baseline values. A statistically significant reduction (p<0.000 in the CFUs count was seen following use of both hand antiseptics but the mean number of CFUs reduction was more in case of alcohol based hand antiseptic(sterillium than herbal based hand antiseptic(Himalaya′s ′PureHands". Conclusion: Using alcohol based antiseptic soap before hygienic hand disinfection will provide maximum benefit in reducing the microbial count.

  11. The Antibacterial and Antioxidant Effect of Grape Seed and Green Tea Extracts on Durability of Tilapia

    Directory of Open Access Journals (Sweden)

    Rozita Golvardzadeh

    2016-10-01

    Full Text Available Background: The current study tried to investigate the antioxidant and anti-bacterial effects of green tea and grape seed extract (with a volume of 2% on durability of Tilapia packed inpolyethylene bags, which were kept in cool temperature of 4 ± 1 °C. Methods: Prepared fish were divided into 3 batches: 2 batches were treated by dipping for 30 min in ethanolic of green tea extract (2% v/v and grape seed (2% v/v, respectively, while the third batch was dipped in distilled water as a control sample. The control and treated fish samples were analyzed for microbiological such as total volatile count and psychrotrophic count, and chemical such as thiobarbituric acid (TBA, and free fatty acid (FFA values. The sensory characteristic was over a period of 20 days. Results: The results indicated that the two extracts' treatments delayed significantly (P < 0.05. Lipid oxidation and process of spoilage in comparison with the psychrotrophic bacteria and total viable count control also remained lower than the proposed acceptable limit (7 log CFU/g. According to sensory, chemical, and microbiological analyses results, the treatment of grape seed extract had high quality and enhanced the beneficial effects on sensory characteristics in comparison with other treatments. Conclusions: the present study showed that the grape seed extract and green tea were very effective in extending the shelf life of Tilapia during refrigerated storage.

  12. Evaluation of copper ion of antibacterial effect on Pseudomonas aeruginosa, Salmonella typhimurium and Helicobacter pylori and optical, mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Hwan [School of Materials Science and Engineering, University of Yonsei, Seoul (Korea, Republic of); Choi, Yu-ri; Kim, Kwang-Mahn [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, University of Yonsei, Seoul (Korea, Republic of); Choi, Se-Young, E-mail: sychoi@yonsei.ac.kr [School of Materials Science and Engineering, University of Yonsei, Seoul (Korea, Republic of)

    2012-02-01

    Antibacterial effect on Pseudomonas aeruginosa, Salmonella typhimurium and Helicobacter pylori of copper ion was researched. Also, additional effects of copper ion coating on optical and mechanical properties were researched as well. Copper ion was coated on glass substrate as a thin film to prevent bacteria from growing. Cupric nitrate was used as precursors for copper ion. The copper ion contained sol was deposited by spin coating process on glass substrate. Then, the deposited substrates were heat treated at the temperature range between 200 Degree-Sign C and 250 Degree-Sign C. The thickness of deposited copper layer on the surface was 63 nm. The antibacterial effect of copper ion coated glass on P. aeruginosa, S. typhimurium and H. pylori demonstrated excellent effect compared with parent glass. Copper ion contained layer on glass showed a similar value of transmittance compared with value of parent glass. The 3-point bending strength and Vickers hardness were 209.2 MPa, 540.9 kg/mm{sup 2} which were about 1.5% and 1.3% higher than the value of parent glass. From these findings, it is clear that copper ion coating on glass substrate showed outstanding effect not only in antibacterial activity but also in optical and mechanical properties as well.

  13. Comparative analysis of internalisation, haemolytic, cytotoxic and antibacterial effect of membrane-active cationic peptides: aspects of experimental setup.

    Science.gov (United States)

    Horváti, Kata; Bacsa, Bernadett; Mlinkó, Tamás; Szabó, Nóra; Hudecz, Ferenc; Zsila, Ferenc; Bősze, Szilvia

    2017-06-01

    Cationic peptides proved fundamental importance as pharmaceutical agents and/or drug carrier moieties functioning in cellular processes. The comparison of the in vitro activity of these peptides is an experimental challenge and a combination of different methods, such as cytotoxicity, internalisation rate, haemolytic and antibacterial effect, is necessary. At the same time, several issues need to be addressed as the assay conditions have a great influence on the measured biological effects and the experimental setup needs to be optimised. Therefore, critical comparison of results from different assays using representative examples of cell penetrating and antimicrobial peptides was performed and optimal test conditions were suggested. Our main goal was to identify carrier peptides for drug delivery systems of antimicrobial drug candidates. Based on the results of internalisation, haemolytic, cytotoxic and antibacterial activity assays, a classification of cationic peptides is advocated. We found eight promising carrier peptides with good penetration ability of which Penetratin, Tat, Buforin and Dhvar4 peptides showed low adverse haemolytic effect. Penetratin, Transportan, Dhvar4 and the hybrid CM15 peptide had the most potent antibacterial activity on Streptococcus pneumoniae (MIC lower than 1.2 μM) and Transportan was effective against Mycobacterium tuberculosis as well. The most selective peptide was the Penetratin, where the effective antimicrobial concentration on pneumococcus was more than 250 times lower than the HC 50 value. Therefore, these peptides and their analogues will be further investigated as drug delivery systems for antimicrobial agents.

  14. Rhizosphere bacteria affected by transgenic potatoes with antibacterial activities compared with the effects of soil, wild-type potatoes, vegetation stage and pathogen exposure

    NARCIS (Netherlands)

    Rasche, F; Hodl, [No Value; Poll, C; Kandeler, E; Gerzabek, MH; van Elsas, JD; Sessitsch, A

    A greenhouse experiment was performed to analyze a potential effect of genetically modified potatoes expressing antibacterial compounds (attacin/cecropin, T4 lysozyme) and their nearly isogenic, nontransformed parental wild types on rhizosphere bacterial communities. To compare plant

  15. Effective bounds on strong unicity in L1-approximation

    DEFF Research Database (Denmark)

    Kohlenbach, Ulrich; Oliva, Paulo B.

    In this paper we present another case study in the general project of Proof Mining which means the logical analysis of prima facie non-effective proofs with the aim of extracting new computationally relevant data. We use techniques based on monotone functional interpretation (developed in [17]) t...

  16. Investigation of antibacterial effects of ethanolic extract of Sumac (Rhus coriaria L. against Escherichia coli in vitro

    Directory of Open Access Journals (Sweden)

    H Moshtaghi

    2013-08-01

    Full Text Available The antibacterial effect of etbhanolic extract of Sumac (Rhus coriaria L. was investigated quantitatively and qualitatively on Escherichia coli. The results of well diffusion test showed that extracts of Sumac in concentration of 0.5%, 1%, 2.5% and 5% could inhibited E. coli. In this study it was shown that MIC of the alcoholic extract of Sumac against E. coli was 6.25 mg/ml and its MBC against this bacterium was 50 mg/ml. The results from evaluation of the antibacterial effects of the Sumac revealed that at 4 and 15 °C, the growth of E. coli in test tubes containing meat extracts has increased Throughout the 48 h of incubation period. Results showed that the growth of this bacteria in different concentration of Sumac extract as decreased in the both tested temperatures in comparison to time zero (p

  17. Evaluation the Antibacterial Effects of Two Commercial Products of Eucalyptus globulus Against Common Microbial Causes of Respiratory Tract Infections

    Directory of Open Access Journals (Sweden)

    Mohammadreza Nahaei, Mahsa Kalejahi 1, Parisa Rahbarfam 1, Solmaz Maleki Dizaj 2, Farzaneh Lotfipour *

    2016-12-01

    Full Text Available Background: Recently, antimicrobial activity of medicinal plants have attained once more importance due to drug resistance of microbial isolates to common antibiotics as well as fewer side effects and low cost of herbal products comparing to chemical drugs. Eucalyptus globules (E. globulus has been widely applied as a natural remedy in respiratory tract infections. The present study focused on the evaluation of antibacterial effect of two commercial products of E. globulus against common microbial causes of respiratory tract infections. To this end, two commercial products of E. globules including inhaler and oral soft capsule with standard expiration date, (in three different batch numbers were purchased from the pharmacy stores of Tabriz city. Methods: The antibacterial efficiency of these products were investigated using Minimum Inhibitory Concentration (MIC, Minimum Bactericidal Concentration (MBC and disk diffusion methods against Staphylococcus aureus, Streptococcus pyogenes and Pseudomona aeruginosa. Results: Based on the obtained results, these commercial products of E. globules showed significant inhibitory effects against Gram-positive bacteria. The findings also indicated that the Eucalyptus inhaler products had more inhibitory effects than Eucalyptus oral soft capsule, however batch to batch variations were of concern. Conclusion: This research presents optimistic result on using the Eucalyptus as an alternative antibacterial agent against respiratory tract pathogenic microorganisms.

  18. Antibacterial activity of acetic and lactic acid against Listeria monocytogenes and their effect on the intracellular constituent release

    Directory of Open Access Journals (Sweden)

    Zoleikha Shiravani

    2017-06-01

    Full Text Available Background: Organic acids (e.g. acetic and lactic acid have been used in foods as natural preservatives. Acetic acid and its salts are used in foods as antimicrobial and acidulant agents. The aim of this study was to evaluate the antibacterial activity of acetic and lactic acids against the Listeria monocytogenes. Materials and Methods: This experimental study was conducted at the Department of Food Hygiene (Faculty of Veterinary Medicine, Urmia University during autumn 2015. The antibacterial effects of acetic and lactic acid against Listeria monocytogenes were determined using minimum inhibitory concentration (MIC, minimum bactericidal concentration (MBC and cell constituents release methods. The concentration ranges of acetic and lactic acid (0.0195-10 and 0.043-22.2 μl/ml, respectively were used to determine the MIC of acids. Results: Based on the results, acetic and lactic acid inhibited the growth of Listeria monocytogenes and acetic acid had stronger effect against the the bacterium. The MIC values for acetic acid and lactic acid were 2.5 and 5 μl/ml, respectively. Cell constituents release showed that acetic and lactic acids are able to lyze the bacterial cell. Conclusion: Acetic and lactic acids were effective in inhibiting the growth of Listeria monocytogenes and the antibacterial effect of acetic acid was stronger than that lactic acid. These acids can be used in foods in combination with other preservatives to inhibit the food borne pathogens and food spoilage microorganisms.

  19. Atomic force microscopy study of the antibacterial effect of fosfomycin on methicillin-resistant Staphylococcus pseudintermedius

    Science.gov (United States)

    Neethirajan, Suresh; DiCicco, Matthew

    2014-08-01

    The influence of fosfomycin on methicillin-resistant Staphylococcus pseudintermedius (MRSP) as the target cell was studied by atomic force microscopy (AFM). Nanoscale images of the effects of the antibiotic fosfomycin on this gram-positive bacterium's cell were obtained in situ without fixing agents. Our study has demonstrated substantial morphological and topographical differences between the control and fosfomycin-treated MRSP cells. The AFM investigations further revealed the rough surface morphology and a 30 % shrinkage in size of the fosfomycin-treated cell and the leakage of cytoplasmic components from the cell. The damage of cell membrane integrity and the cell surface degradation as observed elaborates the antibacterial activity of fosfomycin. The AFM image analysis also reveals that the fosfomycin inhibits cell division, and prevents the adhesion on the surface discouraging the biofilm attachment. The micro-titre plate assay results conform to the atomic force microscopy image analysis. This is the first visual demonstration of the effect of fosfomycin on MRSP cells.

  20. Antibacterial triterpenoids from Melia toosendan

    Directory of Open Access Journals (Sweden)

    Qin Zhu

    2015-01-01

    Full Text Available A new lanostan-type triterpenoid with hydroperoxy group, toosendanin A (1, together with two known triterpenoids, meliastatin 3 (2 and ursolic acid (3, w ere isolated and identified from the stems of Melia toosendan. The structures of these compounds were elucidated by 1D- and 2D-NMR spectra and other spectroscopic studies. These compounds were assayed for the antibacterial activities against some hospital pathogenic bacteria. Toosendanin A (1 exhibited strong antibacterial activity against K. pneumoniae .

  1. Strong delayed interactive effects of metal exposure and warming

    DEFF Research Database (Denmark)

    Debecker, Sara; Dinh, Khuong Van; Stoks, Robby

    2017-01-01

    As contaminants are often more toxic at higher temperatures, predicting their impact under global warming remains a key challenge for ecological risk assessment. Ignoring delayed effects, synergistic interactions between contaminants and warming, and differences in sensitivity across species......’ ranges could lead to an important underestimation of the risks. We addressed all three mechanisms by studying effects of larval exposure to zinc and warming before, during, and after metamorphosis in Ischnura elegans damselflies from high- and lowlatitude populations. By integrating these mechanisms...... was especially remarkable in high-latitude animals, as they appeared almost insensitive to zinc during the larval stage. Second, the well-known synergism between metals and warming was manifested not only during the larval stage but also after metamorphosis, yet notably only in low-latitude damselflies...

  2. Evaluation of chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effects of Aloysia citrodora extract on colon cancer cell line

    OpenAIRE

    Amir Mirzaie; Seyed Ataollah Sadat Shandiz; Hassan Noorbazargan; Elahe Ali Asgary

    2016-01-01

    Background: Aloysia citrodora belongs to the Verbenaceae family of plants, a well-known herbal medicine in Iran. The aim of the present study was to investigate the chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effect of A. citrodora extract against human colon cancer (HT29) cells by using real-time polymerase chain reaction and flow-cytometry methods. Methods: This experimental study was carried out in Islamic Azad University, East Tehran Branch, from March to...

  3. Effect of strong fragrance on olfactory detection threshold.

    Science.gov (United States)

    Fasunla, Ayotunde James; Douglas, David Dayo; Adeosun, Aderemi Adeleke; Steinbach, Silke; Nwaorgu, Onyekwere George Benjamin

    2014-09-01

    To assess the olfactory threshold of healthy volunteers at the University College Hospital, Ibadan and to investigate the effect of perfume on their olfactory detection thresholds. A quasi-experimental study on olfactory detection thresholds of healthy volunteers from September 2013 to November 2013. Tertiary health institution. A structured questionniare was administered to the participants in order to obtain information on sociodemographics, occupation, ability to perceive smell, use of perfume, effects of perfume on appetite and self-confidence, history of allergy, and previous nasal surgery. Participants subjectively rated their olfactory performance. Subsequently, they had olfactory detection threshold testing done at baseline and after exposure to perfume with varied concentrations of n-butanol in a forced triple response and staircase fashion. Healthy volunteers, 37 males and 63 females, were evaluated. Their ages ranged from 19 to 59 years with a mean of 31 years ± 8. Subjectively, 94% of the participants had excellent olfactory function. In the pre-exposure forced triple response, 88% were able to detect the odor at ≤.25 mmol/l concentration while in the post-exposure forced triple response, only 66% were able to detect the odor at ≤.25 mmol/l concentration. There is also a statistical significant difference in the olfactory detection threshold score between the pre-exposure and post-exposure period in the participants (P fragrances affects the olfactory detection threshold. Therefore patients and clinicians should be aware of this and its effects on the outcome of test of olfaction. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

  4. CHEMICAL CONSTITUENTS AND ANTIBACTERIAL EFFECT OF ESSENTIAL OIL OF JAVANEESE PEPPER LEAVES (PIPER RETROFRACTUM VAHL.

    Directory of Open Access Journals (Sweden)

    Yuliasri Jamal

    2013-07-01

    Full Text Available Abstrak Daun cabe jawa (Piper retrofractum Vahl. telah terbukti berkhasiat sebagai bahan antimikroba, akan tetapi belum ada informasi lebih lanjut tentang mekanisme aksi antibakteri dari minyak atsiri daun cabe jawa. Penelitian ini untuk mengetahui pengaruh minyak atsiri daun cabe jawa terhadap bakteri uji sensitif serta difokuskan untuk melihat kerusakan membran sel bakteri melalui analisis protein, asam nukleat dan ion-ion logam kalsium dan kalium. Distilasi uap minyak atsiri dari daun segar cabe jawa (Piper retrofractum Vahl. menghasilkan 0.03% cairan kental kekuningan. Analisis dengan GC-MS mengidentifikasi 4 senyawa sebagai komponen utama, yaitu germakren D (24.20%, tetrametilsiklo[5.3.1.0(4.11]-undek-8-ena (17.73%, ar-turmeron (11.55% dan benzil benzoat (6.28%. Minyak atsiri cabe jawa terbukti aktif melawan beberapa bakteri patogen antara lain Staphylococcus aureus, Bacillus subtilis and Micrococcus luteus dengan diameter daya hambat berturut-turut 8.0; 9.7; 8.5 mm. Pengamatan lebih lanjut memperlihatkan nilai MIC dari minyak atsiri cabe jawa  terhadap B. subtilis adalah 2% (v/v, dan juga merubah morfologi sel dari bakteri yang diobservasi menggunakan SEM. Kata kunci: Piper retrofractum Vah., cabe jawa, minyak atsiri, aktivitas antibakteri Abstract The leaves of Javaneese pepper (Piper retrofractum Vahl. has been proven efficacious as antimicrobial agent, however, there was no further information about action mechanism of antibacterial of Javaneese pepper leaves essential oil. This study was to determine the effect of essential oils of javaneese pepper leaves against bacterial sensitive test and is focused on investigating the damage of cell membranes of bacteria through the analysis of proteins, nucleic acids and metal ions, calcium and potassium. Steam distillation of essential oil from fresh leaves of Javaneese pepper (Piper retrofractum Vahl. gave 0.03 % yellowish viscous liquid. Germacrene D (24.20 %, tetramethylcyclo[5

  5. Stirling engines using working fluids with strong real gas effects

    International Nuclear Information System (INIS)

    Invernizzi, Costante M.

    2010-01-01

    Real gas effects typical of the critical region of working fluids are a powerful tool to increase the energy performances of Stirling cycles, mainly at low top temperatures. To carry out the compression near the critical region the working fluids must have a critical temperature near environmental conditions and the use of organic working substances (pure or in suitable mixtures) as a matter of fact begins compulsory. The moderate thermal stability of the organic working fluids limits the maximum temperatures to 300-400 deg. C and as a consequence, the achievable cycles efficiencies result rather low. Carbon dioxide, with a critical temperature of 31 deg. C, is, among the traditionally inorganic gases, an exception and is considered here in comparison with organic substances. But the good thermodynamics of the cycles allows, in the considered cases, conversion efficiencies of about 20%, with good specific powers. The good energy performance of real gas Stirling cycles is obtained at the cost of high maximum cycle pressure, in the range of at least 100-300 bar. These high pressures nevertheless have large positive effects on the heat power transferred per unit of pumping mechanical power, and the low top temperatures have a positive influence on the material problems for the hottest engine parts.

  6. Antibacterial Effect of Myrtus Communis Hydro-Alcoholic Extract on Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Ali Taheri

    2013-06-01

    Full Text Available Background: Today, due to the changes in the form of the resistance of pathogenic bacteria, discovering new antimicrobial drugs is under study. So, the aim of this study is to evaluate the antimicrobial properties of the extract of the myrtle herb on some of pathogenic bacteria. Materials and Methods: Hydroalcoholic extract of the leaves of myrtle herb was evaluated at 4 concentrations including 10-80 mg/ml on four strains of pathogenic bacteria using penetrative dissemination method together with the measuring diameter of the growth inhibition zone; then the results were compared to four conventional antibiotics. The minimum inhibitory and bactericidal concentrations were studied using macro dilution method. Results: Treatment by the concentration of 80 mg/ml extract of this herb showed the greatest effect on the bacterium Staphylococcus aureus and Vibrio cholera serotype Ogawa which had a significant difference with all other treatments and standard antibiotics (p> 0.05. The extract showed no effect on the bacterium Pseudomonas aeruginosa and just concentration of 80 mg/ml showed a little effect on E. coli and other antibiotics had no significant effect except tetracycline which has little effect on this strain. Minimum inhibitory concentration was 0.2 mg/ml for bacterium Staphylococcus aureus (S. aureus and the maximum for E.coli by 8 mg/ml.Conclusion: This study showed that under study bacteria were more resistant to the antibiotics and the extract of Myrtus communis leaves showed greatest antibacterial effect against S. aureus and V. cholerae cerotype Ogawa.

  7. Titania sol-gel coatings containing silver on newly developed TiSi alloys and their antibacterial effect.

    Science.gov (United States)

    Horkavcová, Diana; Novák, Pavel; Fialová, Iva; Černý, Martin; Jablonská, Eva; Lipov, Jan; Ruml, Tomáš; Helebrant, Aleš

    2017-07-01

    New materials with appropriate mechanical properties and an antibacterial effect are constantly being sought for orthopedic and dental applications. The aim of this study was to investigate newly developed TiSi alloys coated with titania sol-gel containing silver. Titanium alloys with 5 or 10wt% of silicon were prepared by vacuum arc remelting and dip-coated with titania sol containing either AgNO 3 or Ag 3 PO 4 in two concentrations. The size and distribution of the particles in the layer were evaluated, as well as layer compactness (SEM). The antibacterial effect (against E. coli and S. epidermidis) and cytotoxicity (towards L929 and U-2 OS cell lines) of these materials were then tested. Despite cracking of the coatings after firing, the coatings demonstrated very good antibacterial effects against both E. coli and S. epidermidis after 24h of interaction. None of the tested materials were toxic to both cell lines. Collectively, our results suggest that these materials are promising candidates for orthopedic applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Antibacterial effect of two mineral trioxide aggregate (MTA) preparations against Enterococcus faecalis and Streptococcus sanguis in vitro.

    Science.gov (United States)

    Al-Hezaimi, Khalid; Al-Shalan, Thakib A; Naghshbandi, Jafar; Oglesby, Samuel; Simon, James H S; Rotstein, Ilan

    2006-11-01

    The antibacterial effects of gray-colored MTA (GMTA) and white-colored MTA (WMTA) against Enterococcus faecalis and Streptococcus sanguis were assessed in vitro using the tube dilution test. Broth tubes were prepared and divided into experimental and control groups. Aliquots of each of the tested microorganisms were taken from a stock culture and added to each experimental and positive control group. All groups were incubated at 37 degrees C and evaluated for turbidity at 0, 1, 24, 48, and 72-hour time periods. A direct correlation was found between GMTA and WMTA concentrations and their antibacterial effect. Tubes containing GMTA in concentrations of 50, 25, and 12.5 mg/ml did not show E. faecalis growth at any of the time periods tested whereas tubes containing WMTA showed E. faecalis growth at all concentrations and time periods tested. Statistically significant differences were found between tubes containing GMTA in concentrations of 50, 25 and 12.5 mg/ml and tubes containing similar concentrations of WMTA (p faecalis and S. sanguis to MTA differed and that GMTA requires lower concentrations than WMTA to exert the same antibacterial effect against each of the microorganisms tested.

  9. Antibacterial Effects of (Mentha X Piperita L. Hydroalcoholic Extract on the Six Food-Borne Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    H Zandi

    2016-11-01

    Full Text Available Abstract Introduction: Iran is the richest country in terms of distribution of medicinal plants. The antimicrobial effect of plant extracts and essential oils is well known and they are used as a good substitute in food industry to control food-borne pathogens. Due to the antibacterial activity of plant extracts and their efficacy against microorganisms, the aim of this study was to investigate the antibacterial activity of peppermint extract in order to control pathogenic bacteria. Methods: Piperita L., which is one of the species of mint; was used in this invitro-experimental study. The extraction was performed by percolation method. Well - agar method was used for antibacterial effects of extracts. The minimum inhibitory concentration (MIC and minimal bactericidal concentration (MBC were done for six standard bacteria using microdilution method. The test was performed 3 times for each bacterium. Data were analyzed by using SPSS version 16 and t-test. Results: The lowest MIC of peppermint extract on examined microorganisms were observed for Staphylococcus aureus and Enterococcus faecalis (3.25 mg/ ml. Also the maximum diameter of inhibition zone, was related to Staphylococcus aureus (32 mm. Conclusion: Results of this study indicated that peppermint extract has a favorable control effect on the growth of food borne pathogens, which can be used as a perfect preservative for keeping food.

  10. Strong surface effect on direct bulk flexoelectric response in solids

    International Nuclear Information System (INIS)

    Yurkov, A. S.; Tagantsev, A. K.

    2016-01-01

    In the framework of a continuum theory, it is shown that the direct bulk flexoelectric response of a finite sample essentially depends on the surface polarization energy, even in the thermodynamic limit where the body size tends to infinity. It is found that a modification of the surface energy can lead to a change in the polarization response by a factor of two. The origin of the effect is an electric field produced by surface dipoles induced by the strain gradient. The unexpected sensitivity of the polarization response to the surface energy in the thermodynamic limit is conditioned by the fact that the moments of the surface dipoles may scale as the body size

  11. Antibacterial, Antibiofilm Effect of Burdock (Arctium lappa L.) Leaf Fraction and Its Efficiency in Meat Preservation.

    Science.gov (United States)

    Lou, Zaixiang; Li, Cheng; Kou, Xingran; Yu, Fuhao; Wang, Hongxin; Smith, Gary M; Zhu, Song

    2016-08-01

    First, the antibacterial, antibiofilm effect and chemical composition of burdock (Arctium lappa L.) leaf fractions were studied. Then, the efficiency of burdock leaf fractions in pork preservation was evaluated. The results showed that burdock leaf fraction significantly inhibited the growth and biofilm development of Escherichia coli and Salmonella Typhimurium. MICs of burdock leaf fractions on E. coli and Salmonella Typhimurium were both 2 mg/ml. At a concentration of 2.0 mg/ml, the inhibition rates of the fraction on growth and development of E. coli and Salmonella Typhimurium biofilms were 78.7 and 69.9%, respectively. During storage, the log CFU per gram of meat samples treated with burdock leaf fractions decreased 2.15, compared with the samples without treatment. The shelf life of pork treated with burdock leaf fractions was extended 6 days compared with the pork without treatment, and the sensory property was obviously improved. Compared with the control group, burdock leaf fraction treatment significantly decreased the total volatile basic nitrogen value and pH of the meat samples. Chemical composition analysis showed that the burdock leaf fraction consisted of chlorogenic acid, caffeic acid, p-coumaric acid, rutin, cynarin, crocin, luteolin, arctiin, and quercetin. As a vegetable with an abundant source, burdock leaf is safe, affordable, and efficient in meat preservation, indicating that burdock leaf fraction is a promising natural preservative for pork.

  12. Antibacterial Effect of Fructose Laurate Synthesized by Candida antarctica B Lipase-Mediated Transesterification.

    Science.gov (United States)

    Lee, Ki Ppeum; Kim, Hyung Kwoun

    2016-09-28

    Sugar esters are valuable compounds composed of various sugars and fatty acids that can be used as antibacterial agents and emulsifiers in toothpaste and canned foods. For example, fructose fatty acid esters suppress growth of Streptococcus mutans, a typical pathogenic bacterium causing dental caries. In this study, fructose laurate ester was chosen as a target material and was synthesized by a transesterification reaction using Candida antarctica lipase B. We performed a solvent screening experiment and found that a t-butanol/dimethyl sulfoxide mixture was the best solvent to dissolve fructose and methyl laurate. Fructose laurate was synthesized by transesterification of fructose (100 mM) with methyl laurate (30 mM) in t-butanol containing 20% dimethyl sulfoxide. The conversion yield was about 90%, which was calculated based on the quantity of methyl laurate using high-performance liquid chromatography. Fructose monolaurate (Mr 361) was detected in the reaction mixture by high-resolution mass spectrometry. The inhibitory effect of fructose laurate on growth of oral or food spoilage microorganisms, including S. mutans, Bacillus coagulans, and Geobacillus stearothermophilus, was evaluated.

  13. Biotechnological Screening of Microalgal and Cyanobacterial Strains for Biogas Production and Antibacterial and Antifungal Effects

    Science.gov (United States)

    Mudimu, Opayi; Rybalka, Nataliya; Bauersachs, Thorsten; Born, Jens; Friedl, Thomas; Schulz, Rüdiger

    2014-01-01

    Microalgae and cyanobacteria represent a valuable natural resource for the generation of a large variety of chemical substances that are of interest for medical research, can be used as additives in cosmetics and food production, or as an energy source in biogas plants. The variety of potential agents and the use of microalgae and cyanobacteria biomass for the production of these substances are little investigated and not exploited for the market. Due to the enormous biodiversity of microalgae and cyanobacteria, they hold great promise for novel products. In this study, we investigated a large number of microalgal and cyanobacterial strains from the Culture Collection of Algae at Göttingen University (SAG) with regard to their biomass and biogas production, as well antibacterial and antifungal effects. Our results demonstrated that microalgae and cyanobacteria are able to generate a large number of economically-interesting substances in different quantities dependent on strain type. The distribution and quantity of some of these components were found to reflect phylogenetic relationships at the level of classes. In addition, between closely related species and even among multiple isolates of the same species, the productivity may be rather variable. PMID:24957031

  14. Antibacterial effect of hydrogen peroxide-titanium dioxide suspensions in the decontamination of rough titanium surfaces.

    Science.gov (United States)

    Wiedmer, David; Petersen, Fernanda Cristina; Lönn-Stensrud, Jessica; Tiainen, Hanna

    2017-07-01

    The chemical decontamination of infected dental implants is essential for the successful treatment of peri-implantitis. The aim of this study was to assess the antibacterial effect of a hydrogen peroxide-titanium dioxide (H 2 O 2 -TiO 2 ) suspension against Staphylococcus epidermidis biofilms. Titanium (Ti) coins were inoculated with a bioluminescent S. epidermidis strain for 8 h and subsequently exposed to H 2 O 2 with and without TiO 2 nanoparticles or chlorhexidine (CHX). Bacterial regrowth, bacterial load and viability after decontamination were analyzed by continuous luminescence monitoring, live/dead staining and scanning electron microscopy. Bacterial regrowth was delayed on surfaces treated with H 2 O 2 -TiO 2 compared to H 2 O 2 . H 2 O 2 -based treatments resulted in a lower bacterial load compared to CHX. Few viable bacteria were found on surfaces treated with H 2 O 2 and H 2 O 2 -TiO 2 , which contrasted with a uniform layer of dead bacteria for surfaces treated with CHX. H 2 O 2 -TiO 2 suspensions could therefore be considered an alternative approach in the decontamination of dental implants.

  15. Biotechnological Screening of Microalgal and Cyanobacterial Strains for Biogas Production and Antibacterial and Antifungal Effects

    Directory of Open Access Journals (Sweden)

    Opayi Mudimu

    2014-05-01

    Full Text Available Microalgae and cyanobacteria represent a valuable natural resource for the generation of a large variety of chemical substances that are of interest for medical research, can be used as additives in cosmetics and food production, or as an energy source in biogas plants. The variety of potential agents and the use of microalgae and cyanobacteria biomass for the production of these substances are little investigated and not exploited for the market. Due to the enormous biodiversity of microalgae and cyanobacteria, they hold great promise for novel products. In this study, we investigated a large number of microalgal and cyanobacterial strains from the Culture Collection of Algae at Göttingen University (SAG with regard to their biomass and biogas production, as well antibacterial and antifungal effects. Our results demonstrated that microalgae and cyanobacteria are able to generate a large number of economically-interesting substances in different quantities dependent on strain type. The distribution and quantity of some of these components were found to reflect phylogenetic relationships at the level of classes. In addition, between closely related species and even among multiple isolates of the same species, the productivity may be rather variable.

  16. Effects of storage on the physicochemical and antibacterial properties of human milk.

    Science.gov (United States)

    Ogundele, Michael O

    2002-01-01

    Storage of human milk for limited periods of time is unavoidable in neonatal units and also in the home where increasing numbers of mothers go back to work soon after delivery. Many mothers, convinced of the importance of prolonged exclusive or complementary breast-feeding, often express and store human milk for use during the period of separation. This study examines the effects of different storage methods on the pH and some antibacterial activities of human milk. Portions of milk and colostrum samples from healthy lactating mothers were stored at 4 degrees C and -20 degrees C for periods ranging from one day to 12 weeks. The stored milk samples were analysed for pH, bactericidal and bacteria sequestration activities against a serum-sensitive Escherichia coli, and compared with freshly collected samples, with and without EDTA. Milk became progressively more acidic during storage. While the bactericidal activities of refrigerated samples diminished rapidly, up to two-thirds of the original activity level was maintained by freezing for up to three months. The ability of milk fat globule membrane to adhere to suspended bacteria was gradually lost in frozen milk samples, while it was greatly enhanced during the first few days in refrigerated samples, before declining sharply. This study shows that loss of bactericidal activity in refrigerated milk is well compensated for by enhanced bacteria sequestration activity, and allays any fears that might arise concerning the suitability of stored human milk for infant consumption.

  17. Antibacterial effects of the essential oils of commonly consumed medicinal herbs using an in vitro model.

    Science.gov (United States)

    Soković, Marina; Glamočlija, Jasmina; Marin, Petar D; Brkić, Dejan; van Griensven, Leo J L D

    2010-10-27

    The chemical composition and antibacterial activity of essential oils from 10 commonly consumed herbs: Citrus aurantium, C. limon, Lavandula angustifolia, Matricaria chamomilla, Mentha piperita, M. spicata, Ocimum basilicum, Origanum vulgare, Thymus vulgaris and Salvia officinalis have been determined. The antibacterial activity of these oils and their main components; i.e. camphor, carvacrol, 1,8-cineole, linalool, linalyl acetate, limonene, menthol, a-pinene, b-pinene, and thymol were assayed against the human pathogenic bacteria Bacillus subtilis, Enterobacter cloacae, Escherichia coli O157:H7, Micrococcus flavus, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteritidis, S. epidermidis, S. typhimurium, and Staphylococcus aureus. The highest and broadest activity was shown by O. vulgare oil. Carvacrol had the highest antibacterial activity among the tested components.

  18. Effect of heat-setting on UV protection and antibacterial properties of cotton/spandex fabric

    Science.gov (United States)

    Pervez, M. N.; Talukder, M. E.; Shafiq, F.; Hasan, K. M. F.; Taher, M. A.; Meraz, M. M.; Cai, Y.; Lin, Lina

    2018-01-01

    An unexampled approach for simultaneous heat setting process with optimized condition at C3 (140°C, 45 s) and functional finishing, i.e. UV protection and antibacterial properties of cotton/spandex fabric were studied in this research. Experimental results disclosed that, ameliorative antibacterial efficacy and perdurable UV protection of heat-treated cotton/spandex fabrics with best sample A3 among all samples was achieved and mechanical properties also improved as the temperature rose from 120 to 140°C. In addition, Ultraviolet (UV) radiation protection and antibacterial properties are becoming increasingly necessary for human health, and textiles play an important role and this report will be appurtenant to meet regular demand.

  19. DNA replication is the target for the antibacterial effects of nonsteroidal anti-inflammatory drugs.

    Science.gov (United States)

    Yin, Zhou; Wang, Yao; Whittell, Louise R; Jergic, Slobodan; Liu, Michael; Harry, Elizabeth; Dixon, Nicholas E; Kelso, Michael J; Beck, Jennifer L; Oakley, Aaron J

    2014-04-24

    Evidence suggests that some nonsteroidal anti-inflammatory drugs (NSAIDs) possess antibacterial properties with an unknown mechanism. We describe the in vitro antibacterial properties of the NSAIDs carprofen, bromfenac, and vedaprofen, and show that these NSAIDs inhibit the Escherichia coli DNA polymerase III β subunit, an essential interaction hub that acts as a mobile tether on DNA for many essential partner proteins in DNA replication and repair. Crystal structures show that the three NSAIDs bind to the sliding clamp at a common binding site required for partner binding. Inhibition of interaction of the clamp loader and/or the replicative polymerase α subunit with the sliding clamp is demonstrated using an in vitro DNA replication assay. NSAIDs thus present promising lead scaffolds for novel antibacterial agents targeting the sliding clamp. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Antibacterial Effects of the Essential Oils of Commonly Consumed Medicinal Herbs Using an In Vitro Model

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    Dejan Brkić

    2010-10-01

    Full Text Available The chemical composition and antibacterial activity of essential oils from 10 commonly consumed herbs: Citrus aurantium, C. limon, Lavandula angustifolia, Matricaria chamomilla, Mentha piperita, M. spicata, Ocimum basilicum, Origanum vulgare, Thymus vulgaris and Salvia officinalis have been determined. The antibacterial activity of these oils and their main components; i.e. camphor, carvacrol, 1,8-cineole, linalool, linalyl acetate, limonene, menthol, a-pinene, b-pinene, and thymol were assayed against the human pathogenic bacteria Bacillus subtilis, Enterobacter cloacae, Escherichia coli O157:H7, Micrococcus flavus, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella enteritidis, S. epidermidis, S. typhimurium, and Staphylococcus aureus. The highest and broadest activity was shown by O. vulgare oil. Carvacrol had the highest antibacterial activity among the tested components.

  1. Antibacterial Activity and Antibiotic-Enhancing Effects of Honeybee Venom against Methicillin-Resistant Staphylococcus aureus.

    Science.gov (United States)

    Han, Sang Mi; Kim, Joung Min; Hong, In Pyo; Woo, Soon Ok; Kim, Se Gun; Jang, He Rye; Pak, Sok Cheon

    2016-01-12

    Methicillin-resistant Staphylococcus aureus (MRSA), along with other antibiotic resistant bacteria, has become a significant social and clinical problem. There is thus an urgent need to develop naturally bioactive compounds as alternatives to the few antibiotics that remain effective. Here we assessed the in vitro activities of bee venom (BV), alone or in combination with ampicillin, penicillin, gentamicin or vancomycin, on growth of MRSA strains. The antimicrobial activity of BV against MRSA strains was investigated using minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC) and a time-kill assay. Expression of atl which encodes murein hydrolase, a peptidoglycan-degrading enzyme involved in cell separation, was measured by reverse transcription-polymerase chain reaction. The MICs of BV were 0.085 µg/mL and 0.11 µg/mL against MRSA CCARM 3366 and MRSA CCARM 3708, respectively. The MBC of BV against MRSA 3366 was 0.106 µg/mL and that against MRSA 3708 was 0.14 µg/mL. The bactericidal activity of BV corresponded to a decrease of at least 3 log CFU/g cells. The combination of BV with ampicillin or penicillin yielded an inhibitory concentration index ranging from 0.631 to 1.002, indicating a partial and indifferent synergistic effect. Compared to ampicillin or penicillin, both MRSA strains were more susceptible to the combination of BV with gentamicin or vancomycin. The expression of atl gene was increased in MRSA 3366 treated with BV. These results suggest that BV exhibited antibacterial activity and antibiotic-enhancing effects against MRSA strains. The atl gene was increased in MRSA exposed to BV, suggesting that cell division was interrupted. BV warrants further investigation as a natural antimicrobial agent and synergist of antibiotic activity.

  2. The antibacterial effect of photodynamic therapy in dental plaque-derived biofilms

    Science.gov (United States)

    Fontana, C. R.; Abernethy, A. D.; Som, S.; Ruggiero, K.; Doucette, S.; Marcantonio, R. C.; Boussios, C. I.; Kent, R.; Goodson, J. M.; Tanner, A. C. R.; Soukos, N. S.

    2009-01-01

    Background and Objective Photodynamic therapy (PDT) has been advocated as an alternative to antimicrobial agents to suppress subgingival species and treat periodontitis. Bacteria located within dense biofilms, such as those encountered in dental plaques, have been found to be relatively resistant to antimicrobial therapy. In the present study, we investigated the ability of PDT to affect bacteria resistant in biofilms by comparing the photodynamic effects of methylene blue (MB) on human dental plaque microorganisms in planktonic phase and in biofilms. Material and Methods Dental plaque samples were obtained from 10 subjects with chronic periodontitis. Suspensions of plaque microorganisms from 5 subjects were sensitized with MB (25 μg/ml) for 5 minutes followed by exposure to red light. Multi-species microbial biofilms developed from the same plaque samples were also exposed to MB (25 μg/ml) and the same light conditions as their planktonic counterparts. In a second set of experiments, biofilms were developed with plaque bacteria from 5 subjects and sensitized with 25 and 50 μg/ml MB followed by exposure to light as above. After PDT, survival fractions were calculated from colony-forming unit counts. Results In suspension, PDT produced approximately 63% killing of bacteria. In biofilms, the effect of PDT resulted in much lower reductions of microorganisms (32% maximal killing). Conclusion Oral bacteria in biofilms are less affected by PDT than bacteria in planktonic phase. The antibacterial effect of PDT is reduced in biofilm bacteria but not to the same degree as has been reported for treatment with antibiotics under similar conditions. PMID:19602126

  3. Antibacterial Activity and Antibiotic-Enhancing Effects of Honeybee Venom against Methicillin-Resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Sang Mi Han

    2016-01-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA, along with other antibiotic resistant bacteria, has become a significant social and clinical problem. There is thus an urgent need to develop naturally bioactive compounds as alternatives to the few antibiotics that remain effective. Here we assessed the in vitro activities of bee venom (BV, alone or in combination with ampicillin, penicillin, gentamicin or vancomycin, on growth of MRSA strains. The antimicrobial activity of BV against MRSA strains was investigated using minimum inhibitory concentrations (MIC, minimum bactericidal concentrations (MBC and a time-kill assay. Expression of atl which encodes murein hydrolase, a peptidoglycan-degrading enzyme involved in cell separation, was measured by reverse transcription-polymerase chain reaction. The MICs of BV were 0.085 µg/mL and 0.11 µg/mL against MRSA CCARM 3366 and MRSA CCARM 3708, respectively. The MBC of BV against MRSA 3366 was 0.106 µg/mL and that against MRSA 3708 was 0.14 µg/mL. The bactericidal activity of BV corresponded to a decrease of at least 3 log CFU/g cells. The combination of BV with ampicillin or penicillin yielded an inhibitory concentration index ranging from 0.631 to 1.002, indicating a partial and indifferent synergistic effect. Compared to ampicillin or penicillin, both MRSA strains were more susceptible to the combination of BV with gentamicin or vancomycin. The expression of atl gene was increased in MRSA 3366 treated with BV. These results suggest that BV exhibited antibacterial activity and antibiotic-enhancing effects against MRSA strains. The atl gene was increased in MRSA exposed to BV, suggesting that cell division was interrupted. BV warrants further investigation as a natural antimicrobial agent and synergist of antibiotic activity.

  4. Carbon Nanomaterials as Antibacterial Colloids

    Directory of Open Access Journals (Sweden)

    Michael Maas

    2016-07-01

    Full Text Available Carbon nanomaterials like graphene, carbon nanotubes, fullerenes and the various forms of diamond have attracted great attention for their vast potential regarding applications in electrical engineering and as biomaterials. The study of the antibacterial properties of carbon nanomaterials provides fundamental information on the possible toxicity and environmental impact of these materials. Furthermore, as a result of the increasing prevalence of resistant bacteria strains, the development of novel antibacterial materials is of great importance. This article reviews current research efforts on characterizing the antibacterial activity of carbon nanomaterials from the perspective of colloid and interface science. Building on these fundamental findings, recent functionalization strategies for enhancing the antibacterial effect of carbon nanomaterials are described. The review concludes with a comprehensive outlook that summarizes the most important discoveries and trends regarding antibacterial carbon nanomaterials.

  5. [Antibacterial effect of food additives and detergents against histamine-producing bacteria on food contact material surfaces].

    Science.gov (United States)

    Kamii, Eri; Terada, Gaku; Akiyama, Junki; Isshiki, Kenji

    2011-01-01

    We investigated the antibacterial activity of food additives and detergents against histamine-producing bacteria on food contact material surfaces. Based on minimum inhibitory concentration (MIC) testing with Morganella morganii NBRC3848, Raoultella planticola NBRC3317 and Enterobacter aerogenes NCTC10006, we screened nine food additives and four detergents with relatively high inhibitory potency. We prepared food contact material surfaces contaminated with histamine-producing bacteria, and dipped them into fourteen agents (100 µg/mL). Sodium hypochlorite, benzalkonium chloride, benzethonium chloride, n-hexadecyltrimethylammonium chloride and 1-n-hexadecylpyridinium chloride showed antibacterial activity against histamine-producing bacteria. We prepared low concentrations of the five agents (10 and 50 µg/mL) and tested them in the same way. Sodium hypochlorite showed high antibacterial activity at 10 µg/mL, and the other four showed activity at 50 µg/mL. So, washing the material surface with these reagents might be effective to prevent histamine food poisoning owing to bacterial contamination of food contact surfaces.

  6. Effect of seasonality on chemical composition and antibacterial and anticandida activities of Argentine propolis. Design of a topical formulation.

    Science.gov (United States)

    Isla, María Inés; Dantur, Yanina; Salas, Ana; Danert, Carolina; Zampini, Catiana; Arias, Myriam; Ordóñez, Roxana; Maldonado, Luis; Bedascarrasbure, Enrique; Nieva Moreno, María Inés

    2012-10-01

    The effect of seasonality on Argentine propolis collected during one year on its phenolic and flavonoid content and on the growth of Gram-positive and Gram-negative antibiotic resistant bacteria and Candida species was evaluated. Extracts of propolis samples collected in the summer and spring showed higher phenolic and flavonoid contents than the samples collected in other seasons (5.86 to 6.06 mg GAE/mL and 3.77 to 4.23 mg QE/mL, respectively). The propolis collected in summer and autumn showed higher antibacterial activity (30 microg/mL) than the other samples (MIC values between 30 and 120 microg/mL). No antibacterial activity was detected against Gram-negative bacteria. Also, these extracts were able to inhibit the development of five Candida species, with MFC values of 15-120 microg/mL. Pharmaceutical formulations containing the more active propolis extract were prepared. The hydrogel of acrylic acid polymer containing summer propolis extract as an antimicrobial agent showed microbiological, physical and functional stability during storage for 180 days. The pharmaceutical preparation, as well as the propolis extracts, was active against Candida sp. and antibiotic-multi-resistant Gram-positive bacteria. These results reveal that propolis samples collected by scraping in four seasons, especially in summer in Calingasta, San Juan, Argentina, can be used to obtain tinctures and hydrogels with antibacterial and antimycotic potential for topical use.

  7. Investigating the effect of silver coating on the solubility, antibacterial properties, and cytocompatibility of glass microspheres.

    Science.gov (United States)

    Haas, L M; Smith, C M; Placek, L M; Hall, M M; Gong, Y; Mellott, N P; Wren, Anthony W

    2015-10-01

    Silver (Ag) coatings have been incorporated into many medical materials due to its ability to eradicate harmful microbes. In this study, glass microspheres (SiO2-Na2O-CaO-Al2O3) were synthesized and employed as substrates to investigate the effect Ag coating has on glass solubility and the subsequent biological effects. Initially, glasses were amorphous with a glass transition point (T(g)) of 605℃ and microspheres were spherical with a mean particle diameter of 120 µm (±27). The Ag coating was determined to be crystalline in nature and its presence was confirmed using scanning electron microscopy and X-ray photoelectron spectroscopy. Ion release determined that Ag-coated (Ag-S) microspheres increased the Na(+) release rate but slightly reduced the Ca(2+) and Si(4+) release compared to an uncoated control (UC-S). Additionally, the Ag-S reduced the pH to just above neutral (7.3-8.5) compared to the UC-S (7.7-9.1). Antibacterial testing determined significant reductions in planktonic Escherichia coli (p = 0.000), Staphylococcus epidermidis (p = 0.000) and Staphylococcus aureus (p = 0.000) growth as a function of the presence of Ag and with respect to maturation (1, 7, and 30 days). Testing for toxicity levels using L929 Fibroblasts determined higher cell viability for the Ag-S at lower concentrations (5 µg/ml); in addition, no significant reduction in cell viability was observed with higher concentrations (15, 30 µg/ml). © The Author(s) 2015.

  8. Infection Control in Retreatment Cases: In Vivo Antibacterial Effects of 2 Instrumentation Systems.

    Science.gov (United States)

    Rodrigues, Renata C V; Antunes, Henrique S; Neves, Mônica A S; Siqueira, José F; Rôças, Isabela N

    2015-10-01

    This in vivo study compared the antibacterial effects of 2 instrumentation systems in root canal-treated teeth with apical periodontitis. Forty-eight teeth with a single root and a single canal showing post-treatment apical periodontitis were selected for this study. For retreatment, teeth were randomly divided into 2 groups according to the instrumentation system used: Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel) and Twisted File Adaptive (TFA; SybronEndo, Orange, CA). In both groups, 2.5% sodium hypochlorite was the irrigant. Bacteriological samples were taken before (S1) and after chemomechanical preparation (S2). In the TFA group, passive ultrasonic irrigation (PUI) was performed after instrumentation, and samples were also taken after this supplementary step (S2b). DNA was extracted from the clinical samples and subjected to quantitative real-time polymerase chain reaction to evaluate the levels of total bacteria, streptococci, and Enterococcus faecalis. Statistical analyses from quantitative real-time polymerase chain reaction data were performed within groups using the Wilcoxon matched pairs test and between groups using the Mann-Whitney U test and the Fisher exact test with the significance level set at P  .05). PUI did not result in significant improvement in disinfection (P > .05). Both instrumentation systems/treatment protocols were highly effective in significantly reducing the intracanal bacterial counts. No significant difference was observed between the 2 systems in disinfecting the canals of teeth with post-treatment apical periodontitis. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. The effects of bacteria-nanoparticles interface on the antibacterial activity of green synthesized silver nanoparticles.

    Science.gov (United States)

    Ahmad, Aftab; Wei, Yun; Syed, Fatima; Tahir, Kamran; Rehman, Aziz Ur; Khan, Arifullah; Ullah, Sadeeq; Yuan, Qipeng

    2017-01-01

    Neutralization of bacterial cell surface potential using nanoscale materials is an effective strategy to alter membrane permeability, cytoplasmic leakage, and ultimate cell death. In the present study, an attempt was made to prepare biogenic silver nanoparticles using biomolecules from the aqueous rhizome extract of Coptis Chinensis. The biosynthesized silver nanoparticles were surface modified with chitosan biopolymer. The prepared silver nanoparticles and chitosan modified silver nanoparticles were cubic crystalline structures (XRD) with an average particle size of 15 and 20 nm respectively (TEM, DLS). The biosynthesized silver nanoparticles were surface stabilized by polyphenolic compounds (FTIR). Coptis Chinensis mediated silver nanoparticles displayed significant activity against E. coli and Bacillus subtilus with a zone of inhibition 12 ± 1.2 (MIC = 25 μg/mL) and 18 ± 1.6 mm (MIC = 12.50 μg/mL) respectively. The bactericidal efficacy of these nanoparticles was considerably increased upon surface modification with chitosan biopolymer. The chitosan modified biogenic silver nanoparticles exhibited promising activity against E. coli (MIC = 6.25 μg/mL) and Bacillus subtilus (MIC = 12.50 μg/mL). Our results indicated that the chitosan modified silver nanoparticles were promising agents in damaging bacterial membrane potential and induction of high level of intracellular reactive oxygen species (ROS). In addition, these nanoparticles were observed to induce the release of the high level of cytoplasmic materials especially protein and nucleic acids into the media. All these findings suggest that the chitosan functionalized silver nanoparticles are efficient agents in disrupting bacterial membrane and induction of ROS leading to cytoplasmic leakage and cell death. These findings further conclude that the bacterial-nanoparticles surface potential modulation is an effective strategy in enhancing the antibacterial potency of silver nanoparticles

  10. Assessment of antibacterial effect of cinnamon on growth of porphyromons gingivalis from chronic periodontitis patients with deep pockets (in vitro

    Directory of Open Access Journals (Sweden)

    Babak Amoian

    2014-04-01

    Full Text Available   Background and Aims : Antibiotics are commonly used for controlling the growth of porphyromons gingivalis (P.g which is one of the most important etiologic factors in the periodontal diseases. Different side effects of synthetics and chemical drugs such as increasing the drug resistancy in the human pathogens have led to study on the herbal antibacterial effect. The aim of this study was to evaluate the antibacterial effect of cinnamon on the growth of porphyromons gingivalis in chronic periodontitis patients with deep pockets.   Materials and Methods: In this experimental study, samples were provided from patients having pockets. After culturing the microorganism and diagnosis of P.g by gram staining and biochemical tests, cinnamon in different concentrations (10, 50, 100, 250, 500, 750 and 1500 mg/ml with oil solvent were prepared and placed by disks in the cultures medium. Positive controls were amoxicillin, metronidazole, ciprofloxacin, amikacin and gentamycin . Oil was negative control. Then the plates were incubated for 24 hours in 37 0 C and then non-growth halos by disk diffusion method, MIC (Minimum Inhibitory Concentration and MBC (Minimum Bactericidal Concentration were determined. Data were analyzed using One-way ANOVA test.   Results: The results showed that the cinnamon at the concentration of MIC=750 mg/ml had the inhibitory effects of bacteria and at the concentration of MIC=1500 mg/ml had killing effect. However, this antibacterial effect compared with commonly used antibiotics (amoxicillin, metronidazole, was much weaker (P<0.001.   Conclusion: Cinnamon showed an antimicrobial effect on porphyromonas gingivalis in chronic periodontitis patients with deep pockets.

  11. Citrus fruit extracts with carvacrol and thymol eliminated 7-log acid-adapted Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes: A potential of effective natural antibacterial agents.

    Science.gov (United States)

    Chung, Doohyun; Cho, Tae Jin; Rhee, Min Suk

    2018-05-01

    Despite the widespread belief that citrus fruit extracts (CFEs) are microbiologically safe due to their acidity, limited bactericidal effect results in low applicability as antibacterial agent and outbreaks occurred by acid-adapted pathogens. Here, we examined the antibacterial effects of CFEs [lime (Citrus medica), lemon (Citrus limon), calamansi (Citrus microcarpa)] combined with essential oil components (EOCs; carvacrol and thymol) against non-acid-adapted/acid-adapted Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes under 22 °C for 5 min. CFEs (6.9 log CFU/ml). Among the CFEs tested, the highest synergism was shown by calamansi, an exotic citrus fruit previously unrecognized as an antibacterial agent. Although acid-adaptation improved bacterial survival, calamansi (<20%) + EOCs (<0.032%) completely inactivated even the most resistant pathogen (E. coli O157:H7). Validation test also showed that all tested commercial juice products also eliminated acid-adapted pathogens when used with EOCs. Physicochemical analysis of tested CFEs (pH measurement and HPLC analysis of components) revealed that low pH and flavanone (hesperidin) did not contribute to the synergistic bactericidal effects. Rather, the high citric acid content is likely to contribute to the strong synergistic effect with EOCs by damaging susceptible bacterial membranes. Sensory scores for CFEs were not altered by addition of EOCs at concentrations up to 1.5 mM. This study provides new insight into the utility of CFEs with EOCs to improve not only the microbiological safety of food products containing CFEs but also their applicability as natural antibacterial complex. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Spectrum-effect relationships between chemical fingerprints and antibacterial effects of Lonicerae Japonicae Flos and Lonicerae Flos base on UPLC and microcalorimetry

    Directory of Open Access Journals (Sweden)

    Zhilong eShi

    2016-02-01

    Full Text Available The traditional Chinese medicines Lonicerae Japonicae Flos (LJF, Jinyinhua in Chinese and Lonicerae Flos (LF, Shanyinhua in Chinese refer to the flower buds of five plants belonging to the Caprifoliaceae family. Until 2000, all of these were officially listed as a single item, LJF (Jinyinhua, in the Chinese Pharmacopoeia. However, there have recently been many academic controversies concerning the separation and combination of LJF and LF in administrative regulation. Till now there has been little work completed evaluating the relationships between biological activity and chemical properties among these drugs. Microcalorimetry and UPLC were used along with principal component analysis (PCA, hierarchical cluster analysis (HCA, and canonical correlation analysis (CCA to investigate the relationships between the chemical ingredients and the antibacterial effects of LJF and LF. Using multivariate statistical analysis, LJF and LF could be initially separated according to their chemical fingerprints, and the antibacterial effects of the two herbal drugs were divided into two clusters. This result supports the disaggregation of LJF and LF by the Pharmacopoeia Committee. However, the sample of Lonicera fulvotomentosa Hsu et S. C. Cheng turned out to be an intermediate species, with similar antibacterial efficacy as LJF. The results of CCA indicated that chlorogenic acid and 3,4-Dicaffeoylquinic acid were the major components generating antibacterial effects. Furthermore 3,4-Dicaffeoylquinic acid could be used as a new marker ingredient for quality control of LJF and LF.

  13. Evaluation of the in vitro combined antibacterial effect of the leaf ...

    African Journals Online (AJOL)

    The antibacterial activities of the infusion (hot water extract) and methanolic extracts of Bryophyllum pinnatum and Ocimum gratissimum were evaluation against Staphylococcus aureusi ATCC 13709, Escherichia coli ATCC 9637, Bacillus, Pseudomons aeroginosa, Klebsiella pneumonia and Salmonella typhi using the agar ...

  14. Antibacterial effects of Oradex, Gengigel and Salviathymol-n mouthwash on dental biofilm bacteria

    OpenAIRE

    Al-Bayaty, F.H.; Taiyeb-Ali, T.B.; Abdulla, M.A.; Mahmud, Z.B.

    2017-01-01

    Three mouthwashes Gengigel, Oradex and Salviathymol N, were tested using experimental microorganisms included Fusobacterium nucleatum, Streptococcus mitis, Streptococcus constellatus, Eikenella corrodens and dental plaque. Staphylococcus aureus and Escherichia coli were used as internal controls. Antibacterial activity was done by diffusion test. Minimum inhibitory concentration test and assessment of bacterial morphology was carried out using scanning electron microscopy (SEM). Results showe...

  15. Light-activated nanofibre textiles exert antibacterial effects in the setting of chronic wound healing

    Czech Academy of Sciences Publication Activity Database

    Arenbergerová, M.; Arenberger, P.; Bednář, M.; Kubát, Pavel; Mosinger, Jiří

    2012-01-01

    Roč. 21, č. 8 (2012), s. 619-624 ISSN 0906-6705 R&D Projects: GA ČR GAP208/11/2222 Institutional support: RVO:61388955 ; RVO:61388980 Keywords : antibacterial * leg ulcer * light-activated nanofibres Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.578, year: 2012

  16. Effects of Cr2N Precipitation on the Antibacterial Properties of AISI 430 Stainless Steel

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    Je-Kang Du

    2016-03-01

    Full Text Available Based on their mechanical properties and good corrosion resistance, some commercial Ni-Cr stainless steels have been widely applied as biomaterials, including the austenitic 304 stainless steel, the austenitic 316 stainless steel, the duplex 2205 stainless steel, and the ferritic 430 stainless steel. In order to reduce the occurrence of infections resulting from biomaterial implants, instruments, and medical devices, Cu2+ and Ag2+ ions have been added onto biomaterials for increasing the antibacterial properties, but they are known to damage biofilm. The occurrence of nanoparticles can also improve the antibacterial properties of biomaterials through various methods. In this study, we used Escherichia coli and analyzed the microstructures of American Iron and Steel Institute (AISI 430 stainless steel with a 0.18 mass % N alloy element. During a lower temperature aging, the microstructure of the as-quenched specimen is essentially a ferrite and martensite duplex matrix with some Cr2N precipitates formed. Additionally, the antibacterial properties of the alloy for E. coli ranged from 3% to 60%, consistent with the presence of Cr2N precipitates. When aged at a lower temperature, which resulted in nano-Cr2N precipitation, the specimen possessed the highest antibacterial activity.

  17. An in vitro evaluation of antibacterial effect of silver nanoparticles on ...

    African Journals Online (AJOL)

    Administrator

    2011-09-12

    Sep 12, 2011 ... nanoparticles shape, many products commonly summarized under the name nanoparticles can be physically and chemically completely different preparations (Pal et al., 2007). Depending on these factors, nanoparticles can have highly variable antibacterial properties (Merisko-Liversidge et al., 2003),.

  18. Effect of dentin surface modification using carbon nanotubes on dental bonding and antibacterial ability.

    Science.gov (United States)

    Suo, Lai; Li, Zhongjie; Luo, Feng; Chen, Junyu; Jia, Lingling; Wang, Tong; Pei, Xibo; Wan, Qianbing

    2017-11-03

    This study developed carbon nanotube coatings for the dentin surface and investigated the bonding strength and the in vitro antibacterial properties of carbon nanotube-coated dentin. Single-walled carbon nanotubes and multi-walled carbon nanotubes were first modified and then characterized using Fourier-transform infrared spectroscopy, scanning electron microscope, and transmission electron microscopy. Second, dentin samples were coated using either single-walled carbon nanotubes or multi-walled carbon nanotubes and observed under a scanning electron microscope. Then, the shear bonding strength and antibacterial properties of the dentin samples were tested. The results showed that both modified single-walled carbon nanotubes and multi-walled carbon nanotubes formed a stable coating on the dentin surface without affecting the shear bonding strength. Moreover, the antibacterial properties of the single-walled carbon nanotube-coated samples was obviously superior to those of the multi-walled carbon nanotubecoated samples. Consequently, single-walled carbon nanotube coating may be an antibacterial agent for potential application in the dental bonding field.

  19. Effects of antibacterial agents on in vitro ovine ruminal biotransformation of the hepatotoxic pyrrolizidine alkaloid jacobine.

    OpenAIRE

    Wachenheim, D E; Blythe, L L; Craig, A M

    1992-01-01

    Ingestion of pyrrolizidine alkaloids, naturally occurring plant toxins, causes illness and death in a number of animal species. Senecio jacobaea pyrrolizidine alkaloids cause significant economic losses due to livestock poisoning, particularly in the Pacific Northwest. Some sheep are resistant to pyrrolizidine alkaloid poisoning, because ovine ruminal biotransformation detoxifies free pyrrolizidine alkaloids in digesta. Antibacterial agents modify ruminal fermentation. Pretreatment with antib...

  20. Synthesis of ZnO nanoparticles and their antibacterial effects | Arefi ...

    African Journals Online (AJOL)

    The zinc oxide nanoparticles with the average particle size of about 30 nm were synthesized by the chemical technique and their properties were studied with the help of scanning electron microscope and X-ray diffraction. The aim of this study was to detect the antibacterial properties of 0.01, 0.5 and 1% nano-ZnO against ...

  1. Assessment of nanopolyamidoamine-G7 dendrimer antibacterial effect in aqueous solution

    Directory of Open Access Journals (Sweden)

    Mitra Gholami

    2016-06-01

    Conclusion: The NPAMAM-G7 dendrimer with end amine groups exhibited a positive impact on the removal of standard strains, gram-positive and gram-negative bacteria. Therefore, it is possible to use these nanodendrimers as antibacterial in the future.

  2. The Antibacterial Effect of Aqueous Extract of Garlic against Resistant Enterococci

    OpenAIRE

    Shaghayegh Nikpour Moghadam(MSc); Shokoufeh Nikpour Moghadam(MSc)

    2016-01-01

    Background and Objective: Enterococci are relatively nonvirulent bacteria that rarely cause disease. Antimicrobial treatment of Enterococci is often challenging due to their antibiotic resistance. This study aimed to investigate the antibacterial activity of aqueous extract of garlic against Enterococcal isolates. Methods: In this descriptive study, 120 Enterococcus isolates including 70 multidrug-resistant isolates were collected from hospitals of Babol, Iran. Isolates’ susceptibilit...

  3. Microstructure, mechanical properties, bio-corrosion properties and antibacterial properties of Ti-Ag sintered alloys.

    Science.gov (United States)

    Chen, Mian; Zhang, Erlin; Zhang, Lan

    2016-05-01

    In this research, Ag element was selected as an antibacterial agent to develop an antibacterial Ti-Ag alloy by a powder metallurgy. The microstructure, phase constitution, mechanical properties, corrosion resistance and antibacterial properties of the Ti-Ag sintered alloys have been systematically studied by X-ray diffraction (XRD), scanning electron microscope (SEM), compressive test, electrochemical measurements and antibacterial test. The effects of the Ag powder size and the Ag content on the antibacterial property and mechanical property as well as the anticorrosion property have been investigated. The microstructure results have shown that Ti-Ag phase, residual pure Ag and Ti were the mainly phases in Ti-Ag(S75) sintered alloy while Ti2Ag was synthesized in Ti-Ag(S10) sintered alloy. The mechanical test indicated that Ti-Ag sintered alloy showed a much higher hardness and the compressive yield strength than cp-Ti but the mechanical properties were slightly reduced with the increase of Ag content. Electrochemical results showed that Ag powder size had a significant effect on the corrosion resistance of Ti-Ag sintered alloy. Ag content increased the corrosion resistance in a dose dependent way under a homogeneous microstructure. Antibacterial tests have demonstrated that antibacterial Ti-Ag alloy was successfully prepared. It was also shown that the Ag powder particle size and the Ag content influenced the antibacterial activity seriously. The reduction in the Ag powder size was benefit to the improvement in the antibacterial property and the Ag content has to be at least 3wt.% in order to obtain a strong and stable antibacterial activity against Staphylococcus aureus bacteria. The bacterial mechanism was thought to be related to the Ti2Ag and its distribution. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Antibacterial Activity of Probiotic Lactobacillus plantarum HK01: Effect of Divalent Metal Cations and Food Additives on Production Efficiency of Antibacterial Compounds.

    Science.gov (United States)

    Sharafi, Hakimeh; Alidost, Leila; Lababpour, Abdolmajid; Shahbani Zahiri, Hossein; Abbasi, Habib; Vali, Hojatollah; Akbari Noghabi, Kambiz

    2013-06-01

    One hundred and sixty lactic acid bacteria, isolated from Iranian traditional dairy products, were screened for antibacterial potential. Among them, an isolate showing remarkable antibacterial activity against both Staphylococcus aureus (PTCC 1112) and Escherichia coli (PTCC 1338) was selected based on minimum inhibitory concentration (AU/mL). The morphological and biochemical characteristics of the isolate matched the literature description about genus Lactobacillus. Partial sequencing of 16S rRNA gene and its alignment with other Lactobacillus strains revealed that the isolate was closely related to the Lactobacillus plantarum. The isolate also exhibited the highest similarity (>99 %) to L. plantarum. We thus tentatively classified the bacterial isolate as L. plantarum HK01. The antibacterial active compound from HK01 strain remained stable for 45 min at 121 °C, and it reached a maximum activity at the end of log phase and the early part of stationary phase. The antibacterial activity of the test isolate, its probiotic properties and production efficacy through addition of some divalent metal cations and food additives were studied as well. The study of bile salt hydrolase (BSH) activity as a function of growth revealed that HK01 strain hydrolysing up to 5 % of sodium salt of glycodeoxycholic acid, correlated with the presence of bsh gene in the isolate. HK01 strain showed high resistance to lysozyme, good adaptation to simulated gastric juice and a moderate bile tolerance. Results obtained from simulated gastric juice conditions showed no significant difference occured during the 70 min. HK01 strain was classified as a strain with low hydrophobicity (34.2 %). Addition of trisodium citrate dehydrates as a food-grade chelator of divalent cations restored antibacterial compound production in MRS broth. Antibacterial compounds of L. plantarum HK01 endured treatment with 10 g/L of SDS, Tween 20, Tween 80 and urea. Concerning food additives, the results

  5. BETLE LEAF ESSENTIAL OIL FOR HEMOPHILIAC PATIENTS AND ITS ANTIBACTERIAL EFFECTS ON MYCOBACTERIUM TUBERCULOSIS

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    Teguh Hari Sucipto

    2016-09-01

    Full Text Available Betle leaf (Piper betle L. is a medicinal plant. It contains essential oil and shows various biological activities, such as antibacterial, anticoagulant, etc. It is further reported to have low anticoagulant activities; thus, it is highly potential as a candidate for coagulant drug. Coagulant is used to prevent bleeding for patients with blood clotting disorders like hemophilia. In Indonesia, 1,236 people were reported with hemophilia. The standard parameters of anticoagulant activity are the freezing period and the compound concentrations. The purpose of this study was to determine the effect of betle leaf’s essential oil on blood coagulation in patients with factor VIII and IX of blood plasma disorders. The isolation of essential oil is conducted through steam distillation method with two kinds of solvents, namely distilled water and n-hexane. The obtained n-hexane extract is then separated from the liquid-liquid extraction and rotary evaporator. Essential oil is diluted with citrate plasma solution. The test results of blood clots increase as the concentration of essential oils increase. The results are recorded as such: essential oils ½ times dilution of 99.67 seconds; ¼ times dilution of 127 seconds; 1/8 times dilution of 179 seconds; and 1/16 times dilution of 242.67 seconds. The test above proves that the piper betle extract possesses a coagulant activity. The ethanol extract contained in the piper betle could stimulate clotting in the blood cells. It is caused by the increase of blood plasma concentration which further escalate the plasma fluid into the blood cells. Based on this study, the activity of Mycobacterium tuberculosis can be obstructed by betle leaf in ½ times dilution. The extract significantly reduces acid which accelerates bacteria development.

  6. Effect of different ripening stages on walnut kernel quality: antioxidant activities, lipid characterization and antibacterial properties.

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    Amin, Furheen; Masoodi, F A; Baba, Waqas N; Khan, Asma Ashraf; Ganie, Bashir Ahmad

    2017-11-01

    Packing tissue between and around the kernel halves just turning brown (PTB) is a phenological indicator of kernel ripening at harvest in walnuts. The effect of three ripening stages (Pre-PTB, PTB and Post-PTB) on kernel quality characteristics, mineral composition, lipid characterization, sensory analysis, antioxidant and antibacterial activity were investigated in fresh kernels of indigenous numbered walnut selection of Kashmir valley "SKAU-02". Proximate composition, physical properties and sensory analysis of walnut kernels showed better results for Pre-PTB and PTB while higher mineral content was seen for kernels at Post-PTB stage in comparison to other stages of ripening. Kernels showed significantly higher levels of Omega-3 PUFA (C18:3 n3 ) and low n6/n3 ratio when harvested at Pre-PTB and PTB stages. The highest phenolic content and antioxidant activity was observed at the first stage of ripening and a steady decrease was observed at later stages. TBARS values increased as ripening advanced but did not show any significant difference in malonaldehyde formation during early ripening stages whereas it showed marked increase in walnut kernels at post-PTB stage. Walnut extracts inhibited growth of Gram-positive bacteria ( B. cereus, B. subtilis, and S. aureus ) with respective MICs of 1, 1 and 5 mg/mL and gram negative bacteria ( E. coli, P. and K. pneumonia ) with MIC of 100 mg/mL. Zone of inhibition obtained against all the bacterial strains from walnut kernel extracts increased with increase in the stage of ripening. It is concluded that Pre-PTB harvest stage with higher antioxidant activities, better fatty acid profile and consumer acceptability could be preferred harvesting stage for obtaining functionally superior walnut kernels.

  7. Putative histidine kinase inhibitors with antibacterial effect against multi-drug resistant clinical isolates identified by in vitro and in silico screens

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    Velikova, Nadya; Fulle, Simone; Manso, Ana Sousa; Mechkarska, Milena; Finn, Paul; Conlon, J. Michael; Oggioni, Marco Rinaldo; Wells, Jerry M.; Marina, Alberto

    2016-05-01

    Novel antibacterials are urgently needed to address the growing problem of bacterial resistance to conventional antibiotics. Two-component systems (TCS) are widely used by bacteria to regulate gene expression in response to various environmental stimuli and physiological stress and have been previously proposed as promising antibacterial targets. TCS consist of a sensor histidine kinase (HK) and an effector response regulator. The HK component contains a highly conserved ATP-binding site that is considered to be a promising target for broad-spectrum antibacterial drugs. Here, we describe the identification of putative HK autophosphorylation inhibitors following two independent experimental approaches: in vitro fragment-based screen via differential scanning fluorimetry and in silico structure-based screening, each followed up by the exploration of analogue compounds as identified by ligand-based similarity searches. Nine of the tested compounds showed antibacterial effect against multi-drug resistant clinical isolates of bacterial pathogens and include three novel scaffolds, which have not been explored so far in other antibacterial compounds. Overall, putative HK autophosphorylation inhibitors were found that together provide a promising starting point for further optimization as antibacterials.

  8. Effects of Different Systemic Insecticides in Carotenoid Content, Antibacterial Activity and Morphological Characteristics of Tomato (Solanum lycopersicum var Diamante

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    LEXTER R. NATIVIDAD

    2014-02-01

    Full Text Available This study aimed to determine the effects of different systemic insecticides in tomato (Lycopersicon esculentum var. Diamante. The study also assessed different systemic insecticides used in other plants in their effectiveness and suitability to tomato by evaluating the carotenoid content and antibacterial activity of each insecticide. Morphological characteristics such as the weight, the number and the circumference of tomato fruits and the height of the plant were also observed. Moreover, the cost effectiveness was computed. Treatments were designated as follows: Treatment 1- plants sprayed with active ingredient (a.i. cartap hydrochloride; Treatment 2 - plants sprayed with a.i. indoxacarb; Treatment 3- plants sprayed with a.i. chlorantraniliprole and thiamethoxam; Treatment 4 - plants sprayed with a.i. dinotefuran (positive control; and Treatment 5 - no insecticide applied. The experimental design used was Randomized Complete Block Design (RCBD with three replications. The first three systemic insecticides with such active ingredient were not yet registered for tomato plant. Statistical analyses show that there were no significant differences among the weight, the number and the circumference of tomato fruits and the height of the plant for each treatment. Results showed that treatments 1, 2, 3, 4 and 5 extracts have 49.74, 44.16, 48.19, 52.57 and 50.60 μg/g of total carotenoids (TC, respectively. Statistical analysis shows that there no significant differences in the TC content of each treatment. The antibacterial activity of each plant sample showed no significant differences among treatments. Thin layer chromatographic analysis revealed that there were equal numbers of spots for all the plant samples.The study concluded that systemic insecticide with a.i. cartap hydrochloride be introduced to the farmers as insecticide for tomato plant since it shows comparable effect with the registered insecticide (T4 based on the morphological

  9. Modeling the synergistic antibacterial effects of honey characteristics of different botanical origins from the Sahara Desert of Algeria.

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    Laallam, Hadda; Boughediri, Larbi; Bissati, Samia; Menasria, Taha; Mouzaoui, Mohamed S; Hadjadj, Soumia; Hammoudi, Rokia; Chenchouni, Haroun

    2015-01-01

    Honey has multiple therapeutic properties due to its composition with diverse components. This study aims to investigate the antimicrobial efficacy of Saharan honeys against bacterial pathogens, the variation of honey floral origins, and its physicochemical characteristics. The antimicrobial activity of 32 samples of honey collected from the Algerian Sahara Desert was tested on four bacteria; Bacillus subtilis, Clostridium perfringens, Escherichia coli, and Staphylococcus aureus. The botanical origin of honeys and their physicochemical properties were determined and their combined antibacterial effects were modeled using a generalized linear mixed model (GLMM). Out of the 32 study samples, 14 were monofloral and 18 were multifloral. The pollen density was on average 7.86 × 10(6) grains/10 g of honey, water content was 14.6%, electrical conductivity (EC) was 0.5 μS/cm, pH was 4.38 ± 0 50, hydroxymethylfurfural (HMF) content was 82 mg/kg of honey, total sugars = 83%, reducing sugars = 71%, and the concentration of proline = 525.5 ± 550.2 mg/kg of honey. GLMM revealed that the antibacterial effect of honey varied significantly between bacteria and floral origins. This effect increased with increasing of water content and reducing sugars in honey, but it significantly decreased with increase of honey EC. E. coli was the most sensitive species with an inhibition zone of 10.1 ± 4.7 mm, while C. perfringens was the less sensitive. Honeys dominated by pollen of Fabaceae sp. were most effective with an overall antimicrobial activity equals to 13.5 ± 4.7 mm. Saharan honeys, of certain botanical origins, have physicochemical and pollinic characteristics with relevant potential for antibacterial purposes. This encourages a more comprehensive characterization of honeys with in vivo and in vitro investigations.

  10. Modeling the synergistic antibacterial effects of honey characteristics of different botanical origins from the Sahara Desert of Algeria

    Science.gov (United States)

    Laallam, Hadda; Boughediri, Larbi; Bissati, Samia; Menasria, Taha; Mouzaoui, Mohamed S.; Hadjadj, Soumia; Hammoudi, Rokia; Chenchouni, Haroun

    2015-01-01

    Background: Honey has multiple therapeutic properties due to its composition with diverse components. Objectives: This study aims to investigate the antimicrobial efficacy of Saharan honeys against bacterial pathogens, the variation of honey floral origins, and its physicochemical characteristics. Materials and Methods: The antimicrobial activity of 32 samples of honey collected from the Algerian Sahara Desert was tested on four bacteria; Bacillus subtilis, Clostridium perfringens, Escherichia coli, and Staphylococcus aureus. The botanical origin of honeys and their physicochemical properties were determined and their combined antibacterial effects were modeled using a generalized linear mixed model (GLMM). Results: Out of the 32 study samples, 14 were monofloral and 18 were multifloral. The pollen density was on average 7.86 × 106 grains/10 g of honey, water content was 14.6%, electrical conductivity (EC) was 0.5 μS/cm, pH was 4.38 ± 0 50, hydroxymethylfurfural (HMF) content was 82 mg/kg of honey, total sugars = 83%, reducing sugars = 71%, and the concentration of proline = 525.5 ± 550.2 mg/kg of honey. GLMM revealed that the antibacterial effect of honey varied significantly between bacteria and floral origins. This effect increased with increasing of water content and reducing sugars in honey, but it significantly decreased with increase of honey EC. E. coli was the most sensitive species with an inhibition zone of 10.1 ± 4.7 mm, while C. perfringens was the less sensitive. Honeys dominated by pollen of Fabaceae sp. were most effective with an overall antimicrobial activity equals to 13.5 ± 4.7 mm. Conclusion: Saharan honeys, of certain botanical origins, have physicochemical and pollinic characteristics with relevant potential for antibacterial purposes. This encourages a more comprehensive characterization of honeys with in vivo and in vitro investigations. PMID:26594206

  11. Evaluation of chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effects of Aloysia citrodora extract on colon cancer cell line

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    Amir Mirzaie

    2016-06-01

    Full Text Available Background: Aloysia citrodora belongs to the Verbenaceae family of plants, a well-known herbal medicine in Iran. The aim of the present study was to investigate the chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effect of A. citrodora extract against human colon cancer (HT29 cells by using real-time polymerase chain reaction and flow-cytometry methods. Methods: This experimental study was carried out in Islamic Azad University, East Tehran Branch, from March to September of 2014. At first, the A. citrodora chemical constituents were analyzed by gas chromatography-mass spectrometry (GC-MS technique. In addition, antioxidant assay, antibacterial and anti-cancer effect was performed using 1,1-diphenyl-2-picrylhydrazyl (DPPH, disk diffusion and 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT methods, respectively. The half maximal inhibitory concentration (IC50 value was calculated. We extracted total RNA molecules by using RNX solution, after which cDNA was synthesized. Finally, the pro-apoptotic (Bax and anti-apoptotic (Bcl2 gene expression was performed by real-time polymerase chain reaction and apoptotic effects were analyzed using Flow-cytometry method. Results: GC-MS analysis of Aloysia citrodora extract was shown 37 major components and the most frequent component was belonged to Spathulenol (17.57% and Caryophyllene oxide (15.15% The antioxidant activity of the extract was IC50= 0.6±0.03 mg/ml. The maximum and minimum antibacterial effects of extract were belonged to gram-negative and gram-positive bacteria, respectively. Cytotoxic results revealed that the A.citrodora extract have IC50= 20.1±0.78 mg/ml against colon cancer (HT29 cell line and real-time polymerase chain reaction results showed the expression level of Bax and Bcl2 was increased and decreased respectively in colon cancer cell line (3.470±0.72 (P< 0.05, 0.43±0.35 (P< 0.05. In addition, the flow-cytometry results indicated the 38

  12. Modeling the synergistic antibacterial effects of honey characteristics of different botanical origins from the Sahara Desert of Algeria

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    Hadda eLAALLAM

    2015-11-01

    Full Text Available Background: Honey has multiple therapeutic properties due to its composition with diverse components.Objectives: This study aims to investigate the antimicrobial efficacy of Saharan honeys against bacterial pathogens, the variation of honey floral origins and its physicochemical characteristics.Materials and Methods: The antimicrobial activity of 32 samples of honey collected from the Algerian Sahara Desert was tested on four pathogenic bacteria; Bacillus subtilis, Clostridium perfringens, Escherichia coli and Staphylococcus aureus. The botanical origin of honeys and their physicochemical properties were determined and their combined antibacterial effects were modeled using a generalized linear mixed model (GLMM.Results: Out of the 32 study samples, 14 were monofloral and 18 were multifloral. The pollen density was on average 7.86 × 106 grains/10 g of honey, water content was 14.6%, electrical conductivity was 0.5 μS/cm, pH was 4.38±0 50, hydroxymethylfurfural content was 82 mg/kg of honey, total sugars = 83%, reducing sugars = 71%, and the concentration of proline = 525.5±550.2 mg/kg of honey. GLMM revealed that the antibacterial effect of honey varied significantly between bacteria and floral origins. This effect increased with increasing of water content and reducing sugars in honey, but it significantly decreased with increase of honey electrical conductivity. E. coli was the most sensitive species with an inhibition zone of 10.1±4.7 mm, while C. perfringens was the less sensitive with 3.9±5.4 mm. Honeys dominated by pollen of Fabaceae sp. were most effective with an overall antimicrobial activity equals to 13.5±4.7 mm.Conclusion: Saharan honeys, of certain botanical origins, have physicochemical and pollinic characteristics with relevant potential for antibacterial purposes. This encourages a more comprehensive characterization of honeys with in vivo and in vitro investigations.Keywords: Honey characterization; antibacterial effects

  13. Povidone-Iodine-Based Polymeric Nanoparticles for Antibacterial Applications.

    Science.gov (United States)

    Gao, Tianyi; Fan, Hongbo; Wang, Xinjie; Gao, Yangyang; Liu, Wenxin; Chen, Wanjun; Dong, Alideertu; Wang, Yan-Jie

    2017-08-09

    As microbial contamination is becoming more and more serious, antibacterial agents play an important role in preventing and removing bacterial pathogens from microbial pollution in our daily life. To solve the issues with water solubility and antibacterial stability of PVP-I 2 (povidone-iodine) as a strong antibacterial agent, we successfully obtain hydrophobic povidone-iodine nanoparticles (povidone-iodine NPs) by a two-step method related to the advantage of nanotechnology. First, the synthesis of poly(N-vinyl-2-pyrrolidone-co-methyl methacrylate) nanoparticles, i.e., P(NVP-MMA) NPs, was controlled by tuning a feed ratio of NVP to MMA. Then, the products P(NVP-MMA) NPs were allowed to undergo a complexation reaction with iodine, resulting in the formation of a water-insoluble antibacterial material, povidone-iodine NPs. It is found that the feed ratio of NVP to MMA has an active effect on morphology, chemical composition, molecular weight, and hydrophilic-hydrophobic properties of the P(NVP-MMA) copolymer after some technologies, such as SEM, DLS, elemental analysis, 1 H NMR, GPC, and the contact angle test, were used in the characterizations. The antibacterial property of povidone-iodine NPs was investigated by using Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa) as model bacteria with the colony count method. Interestingly, three products, such as glue, ink, and dye, after the incorporation of povidone-iodine NPs, show significant antibacterial properties. It is believed that, with the advantage of nanoscale morphology, the final povidone-iodine NPs should have great potential for utilization in various fields where antifouling and antibacterial properties are highly required.

  14. A cytotoxicity and comparative antibacterial study on the effect of Zataria multiflora Boiss, Trachyspermum copticum essential oils, and Enrofloxacin on Aeromonas hydrophila.

    Science.gov (United States)

    Malekinejad, Hassan; Bazargani-Gilani, Behnaz; Tukmechi, Amir; Ebrahimi, Hadi

    2012-01-01

    this study designed to test the antibacterial potency of enrofloxacin (ENR) and essential oils from Zataria multiflora Boiss (ZEO) and Trachyspermum copticum (TEO) on Aeromonas hydrophila. The antibacterial potency of test compounds was determined by several methods including the inhibition zone diameter determination, microbroth dilution method and colorimetric method of MTT. The cytotoxicity of test substances was assessed on Chinook salmon (Oncorhynchus tshawytscha) embryo (CHSE-214) cells. RESULTS showed that ENR and tested essential oils exert antibacterial effect against A. hydrophila. Moreover, ENR exerted the most potent antibacterial effect with MIC values of 62.5 ng/ml. The natural compounds of ZEO and TEO also showed antibacterial effects with rather high MIC values of 0.315 mg/ml, and 1.25 mg/ml, respectively. None of the tested substances showed toxicity on CHSE-24 cells. It is concluded that ZEO and TEO could be applied to prevent from A. hydrophila infection. Moreover, data also suggest that MTT method could be both cost- and time-effective and accurate method of MIC determination.

  15. A cytotoxicity and comparative antibacterial study on the effect of Zataria multiflora Boiss, Trachyspermum copticum essential oils, and Enrofloxacin on Aeromonas hydrophila

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    Hassan Malekinejad

    2012-09-01

    Full Text Available Objective: this study designed to test the antibacterial potency of enrofloxacin (ENR and essential oils from Zataria multiflora Boiss (ZEO and Trachyspermum copticum (TEO on Aeromonas hydrophila. Material and Methods: The antibacterial potency of test compounds was determined by several methods including the inhibition zone diameter determination, microbroth dilution method and colorimetric method of MTT. The cytotoxicity of test substances was assessed on Chinook salmon (Oncorhynchus tshawytscha embryo (CHSE-214 cells. Results: Results showed that ENR and tested essential oils exert antibacterial effect against A. hydrophila. Moreover, ENR exerted the most potent antibacterial effect with MIC values of 62.5 ng/ml. The natural compounds of ZEO and TEO also showed antibacterial effects with rather high MIC values of 0.315 mg/ml, and 1.25 mg/ml, respectively. None of the tested substances showed toxicity on CHSE-24 cells. Conclusion: It is concluded that ZEO and TEO could be applied to prevent from A. hydrophila infection. Moreover, data also suggest that MTT method could be both cost- and time-effective and accurate method of MIC determination.

  16. Antibacterial effect of the laser-generated Se nanocoatings on Staphylococcus aureus and Pseudomonas aeruginosa biofilms

    Science.gov (United States)

    Ionin, A. A.; Ivanova, A. K.; Khmel'nitskii, R. A.; Klevkov, Yu V.; Kudryashov, S. I.; Levchenko, A. O.; Nastulyavichus, A. A.; Rudenko, A. A.; Saraeva, I. N.; Smirnov, N. A.; Zayarny, D. A.; Gonchukov, S. A.; Tolordava, E. R.

    2018-01-01

    The antibacterial properties of selenium nanoparticles (Se NPs) were successfully demonstrated in vitro for Staphylococcus aureus and Pseudomonas aeruginosa biofilms. The possible mechanisms of antibacterial impact included the emergence of reactive oxygen species, induced by free radicals on the NP surface and accompanied by subsequent oxidative stress, as well as mechanical decomposition of the mitochondrial membrane. Se nanocoatings were deposited on bare and silver-coated silica glass substrates via inkjet printing with concentrated nanoinks, prepared by infrared laser-ablative processing of a solid Se target in a 50%-isopropyl solution. The resulted porous nanofilms with high-percentage surface coverage, consisting of spherical Se NPs and Se nanorods, were characterized by means of standard microscopy techniques (optical, scanning electron, transmission), UV-vis-IR and EDX spectroscopy.

  17. Potentiating the antibacterial effect of silver nanospheres by surface-capping with chlorhexidine gluconate

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    Priyadarshini, Balasankar Meera; Fawzy, Amr S.

    2017-04-01

    In this work, the commercial polyvinylpyrrolidone (PVP)-capped silver nanospheres (Ag-NSP) were surface decorated with chlorhexidine gluconate (CHXg) for potentiating the antibacterial properties of Ag-NSP. Different formulations of CHXg-loaded Ag-NSP (Ag-NSP/CHXg) were prepared by varying the incubation times (0.5, 1.5, and 3 h). A thorough characterization of Ag-NSP/CHXg nanospheres has been carried out by dynamic light scattering (DLS), transmission electron microscopy (TEM), energy-dispersive surface elemental composition spectral analysis (SEM/EDX), Fourier transform infrared spectroscopy (FTIR), percentage (%) CHXg loading efficiency (LE), in vitro CHXg and Ag+ ion release, antibacterial/biofilm inhibition assay, and human mesenchymal stem cells (hMSCs) cytotoxicity evaluation. DLS measured nanospheres to be fashion showing maximum release of 74.83 ± 20.67% from Ag-NSP/CHXg-3h at 14 days. A slow release of Ag+ ions was detected; however, the surface decoration of Ag-NSP substantially hampered/restricted the liberation of ions. Agar well diffusion, MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium), and crystal violet assay suggested good antibacterial/antibiofilm activity of Ag-NSP/CHXg that correlated with the increasing %LE of nanospheres. hMSCs cytotoxicity study showed low toxicity properties of all nanosphere formulations, except for Ag-NSP/CHXg-3h, affecting the cell viability at all proposed concentrations and exposure time points. CHXg accentuated the antibacterial properties of Ag-NSP.

  18. A randomised trial comparing the antibacterial effects of dentine primers against bacteria in natural root caries.

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    Rolland, S L; McCabe, J F; Imazato, S; Walls, A W G

    2011-01-01

    As people are living longer and retaining their teeth into old age, root caries is an increasingly significant problem. A minimally invasive treatment strategy, involving sealing the root caries lesion with an antibacterial resin sealant, could be highly beneficial. The aim of this study was to compare the antibacterial properties of the primers of two proprietary dentine bonding agents, Clearfil SE Bond (SE; Kuraray Medical, Japan) and Clearfil Protect Bond (PB; Kuraray Medical), which contains the antibacterial monomer methacryloyloxydodecylpyridinium bromide. Fifty-two root caries lesions were identified and randomly assigned to a primer. The lesion was cleaned, isolated, sampled with a sharp spoon excavator, a primer applied and a second sample taken. Samples were transported in fastidious anaerobe broth, vortex-dispersed and serial dilutions inoculated onto selective agars. Reduction in colony-forming units (CFU, %) after primer application was calculated for both primers for bacterial growth on each selective agar and compared to a hypothesised mean of 100% (one-sample t test, p < 0.05). No significant differences between primers were seen, indicating efficient bacterial elimination by both materials. Comparing percent reduction between SE and PB for each agar (Mann-Whitney test, p < 0.05), a significantly greater CFU reduction by PB was seen for streptococci but not other bacteria. More lesions exhibited bacterial growth and several lesions demonstrated marked bacterial growth after treatment with SE compared with PB. Therefore, PB appears to exhibit superior antimicrobial properties, particularly against streptococci. Both primers are highly antibacterial towards root caries bacteria and may therefore be suitable for minimally invasive treatment. Copyright © 2011 S. Karger AG, Basel.

  19. Antibacterial effect of silver nanoparticles and capsaicin against MDR-ESBL producing Escherichia coli: An in vitro study

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    Debasish Kar

    2016-10-01

    Full Text Available Objective: To evaluate the antibacterial property of silver nanoparticles (AgNPs and capsaicin against multidrug resistant (MDR and extended spectrum beta-lactamase (ESBL producing Escherichia coli of bovine and poultry origin. Methods: Antibacterial efficacy of AgNPs and capsaicin was measured using broth dilution method. Five MDR-ESBL producing E. coli isolates of poultry (PEC4, PEC6, PEC15 and PEC16 and cattle mastitis origin (MEC2 were taken to evaluate the antibacterial effect of AgNPs and capsaicin. Results: At 50 mmol/L AgNPs, the viability of MDR of bacterial pathogens was reduced to almost 80%–90% and at 1000 mmol/L, the viability went down to 0%–3%. The minimum inhibitory concentration (MIC50 of AgNPs against these MDR-ESBL producing isolates was found to vary between 172–218 mmol/L whereas the MIC80 varied between 450–640 mmol/L. Capsaicin showed more prominent bactericidal effect and only at 2.5 mmol/L concentration, the viability was shown to be reduced by 20%–35% whereas at 7.5 mmol/L concentration, there was approximately 60% reduction in viability. Further at 25 mmol/L concentration, the viability was reduced to 0%–8%. The MIC50 and MIC80 of capsaicin against these MDRESBL producing isolates were found to vary between 4.6–7.5 mmol/L and 10.9–16.9 mmol/L, respectively. Conclusions: The results point out that capsaicin and AgNPs could be of use in treating ESBL infection.

  20. Effects of dual antibacterial agents MDPB and nano-silver in primer on microcosm biofilm, cytotoxicity and dentin bond properties

    Science.gov (United States)

    Zhang, Ke; Cheng, Lei; Imazato, Satoshi; Antonucci, Joseph M.; Lin, Nancy J.; Lin-Gibson, Sheng; Bai, Yuxing; Xu, Hockin H. K.

    2013-01-01

    Objectives The objective of this study was to investigate the effects of dentin primer containing dual antibacterial agents, namely, 12-methacryloyloxydodecylpyridinium bromide (MDPB) and nanoparticles of silver (NAg), on dentin bond strength, dental plaque microcosm biofilm response, and fibroblast cytotoxicity for the first time. Methods Scotchbond Multi-Purpose (SBMP) was used as the parent bonding agent. Four primers were tested: SBMP primer control (referred to as “P”), P+5%MDPB, P+0.05%NAg, and P+5%MDPB+0.05%NAg. Dentin shear bond strengths were measured using extracted human teeth. Biofilms from the mixed saliva of 10 donors were cultured to investigate metabolic activity, colony-forming units (CFU), and lactic acid production. Human fibroblast cytotoxicity of the four primers was tested in vitro. Results Incorporating MDPB and NAg into primer did not reduce dentin bond strength compared to control (p>0.1). SEM revealed well-bonded adhesive-dentin interfaces with numerous resin tags. MDPB or NAg each greatly reduced biofilm viability and acid production, compared to control. Dual agents MDPB+NAg had a much stronger effect than either agent alone (pcontrol. There was no difference in cytotoxicity between commercial control and antibacterial primers (p>0.1). Conclusions The method of using dual agents MDPB+NAg in the primer yielded potent antibacterial properties. Hence, this method may be promising to combat residual bacteria in tooth cavity and invading bacteria at the margins. The dual agents MDPB+NAg may have wide applicability to other adhesives, composites, sealants and cements to inhibit biofilms and caries. PMID:23402889

  1. [Dental plaque microcosm biofilm behavior on a resin composite incorporated with nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt].

    Science.gov (United States)

    Junling, Wu; Qiang, Zhang; Ruinan, Sun; Ting, Zhu; Jianhua, Ge; Chuanjian, Zhou

    2015-12-01

    To develop a resin composite incorporated with nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt, and to measure its effect on human dental plaque microcosm biofilm. A novel nano-antibacterial inorganic filler containing long-chain alkyl quaternary ammonium salt was synthesized according to methods introduced in previous research. Samples of the novel nano-antibacterial inorganic fillers were modified by a coupling agent and then added into resin composite at 0%, 5%, 10%, 15% or 20% mass fractions; 0% composite was used as control. A flexural test was used to measure resin composite mechanical properties. Results showed that a dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony-forming unit (CFU) counts, lactic acid production, and live/dead assay of biofilm on the resin composite were calculated to test the effect of the resin composite on human dental plaque microcosm biofilm. The incorporation of nano-antibacterial inorganic fillers with as much as 15% concentration into the resin composite showed no adverse effect on the mechanical properties of the resin composite (P > 0.05). Resin composite containing 5% or more nano-antibacterial inorganic fillers significantly inhibited the metabolic activity of dental plaque microcosm biofilm, suggesting its strong antibacterial potency (P < 0.05). This novel resin composite exhibited a strong antibacterial property upon the addition of up to 5% nano-antibacterial inorganic fillers, thereby leading to effective caries inhibition in dental application.

  2. Antibacterial effects of medicinal plant extracts against Lactococcus garvieae, the etiological agent of rainbow trout lactococcosis

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    Mohammad Saeid Fereidouni

    2013-05-01

    Full Text Available Eight medicinal plants were assessed for antimicrobial activity against Lactococcus garvieae isolate obtained from diseased Oncorhynchus mykiss collected from rainbow trout fish farms in Iran. Lactococcus garvieae is among the major pathogens of a large number of fish species cultured in fresh and marine recirculating and net pen production systems. The antibacterial activity of the medicinal plants against L. garvieae was evaluated using disc diffusion, well diffusion and minimum inhibitory concentration. Results showed that the extracts and essential oils had a relatively high antibacterial activity against L. garvieae. Of the plants studied, the most active extracts were those from the methanol extract of Peganum harmala, the essential oil of Satureja bachtiarica, the ethanol extract of Juglans regia and Trachyspermum copticum with minimum inhibitory concentration (MIC of 105, 126, 510 and 453 μg/ml, respectively. Conversly, some of the extracts such as Quercus branti Lindley and Glycyrrhiza glabra L. had lower activity against L. garvieae with MIC values of 978 and 920 μg/ml respectively. Plant extracts as natural and environment- friendly compounds can be an important source of antibacterial agents against L. garvieae. They may be used for disinfection of instruments and rainbow trout raceways or treatment of the fish.

  3. Non-thermal hydrogen plasma processing effectively increases the antibacterial activity of graphene oxide

    Science.gov (United States)

    Ke, Zhigang; Ma, Yulong; Zhu, Zhongjie; Zhao, Hongwei; Wang, Qi; Huang, Qing

    2018-01-01

    Graphene-based materials (GMs) are promising antibacterial agents which provide an alternative route to treat pathogenic bacteria with resistance to conventional antibiotics. To further improve their antibacterial activity, many methods have been developed to functionalize the GMs with chemicals. However, the application of additional chemicals may pose potential risks to the environment and human being. Herein, a radio-frequency-driven inductively coupled non-thermal hydrogen plasma was used to treat and reduce graphene oxide (GO) without using any other chemicals, and we found that the plasma-reduced GO (prGO) is with significantly higher bactericidal activity against Escherichia coli. The mechanism of the increased antibacterial activity of prGO is due to that plasma processing breaks down the GO sheets into smaller layers with more rough surface defects, which can thus induce more destructive membrane damages to the bacteria. This work sets another good example, showing that plasma processing is a green and low-cost alternative for GM modification for biomedical applications.

  4. Surface conjugation of poly (dimethyl siloxane) with itaconic acid-based materials for antibacterial effects

    Science.gov (United States)

    Birajdar, Mallinath S.; Cho, Hyunjoo; Seo, Youngmin; Choi, Jonghoon; Park, Hansoo

    2018-04-01

    Poly (dimethyl siloxane) (PDMS) is widely used in various biomedical applications. However, the PDMS surface is known to cause bacterial adhesion and protein absorption issues due to its high hydrophobicity. Therefore, the development of antibacterial and anti-protein products is necessary to prevent these problems. In this study, to improve its antibacterial property and prevent protein adsorption, PDMS surfaces were conjugated with itaconic acid (IA) and poly (itaconic acid) (PIA) via a chemical method. Additionally, IA and PIA were physically blended with PDMS to compare the antibacterial properties of these materials with those of the chemically conjugated PDMS surfaces. The successful synthesis of the PIA polymer structure was confirmed by proton nuclear magnetic resonance (1H NMR) spectroscopy. The successful conjugation of IA and PIA on PDMS was confirmed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), water contact angle measurements, and microbicinchoninic acid (BCA) protein assay analyses. The PDMS surfaces functionalized with IA and PIA by the conjugation method better prevented protein adsorption than the bare PDMS. Therefore, these surface-conjugated PDMS can be used in various biomedical applications.

  5. Assessment of antibacterial and cytotoxic effects of orthodontic stainless steel brackets coated with different phases of titanium oxide: An in-vitro study.

    Science.gov (United States)

    Baby, Roshen Daniel; Subramaniam, Siva; Arumugam, Ilakkiya; Padmanabhan, Sridevi

    2017-04-01

    Our objective was to assess the antibacterial and cytotoxic effects of orthodontic stainless steel brackets coated with different phases of photocatalytic titanium oxide. From a total sample of 115 brackets, 68 orthodontic stainless steel brackets were coated with titanium oxide using a radiofrequency magnetron sputtering machine. The coated brackets were then converted into 34 each of the anatase and rutile phases of titanium oxide. These brackets were subdivided into 4 groups for antibacterial study and 3 groups for cytotoxicity study. Brackets for the antibacterial study were assessed against the Streptococcus mutans species using microbiologic tests. Three groups for the cytotoxicity study were assessed using the thiazolyl tetrazolium bromide assay. The antibacterial study showed that both phases were effective, but the rutile phase of photocatalytic titanium oxide had a greater bactericidal effect than did the anatase phase. The cytotoxicity study showed that the rutile phase had a greater decrease in viability of cells compared with the anatase phase. It is recommended that orthodontic brackets be coated with the anatase phase of titanium oxide since they exhibited a significant antibacterial property and were only slightly cytotoxic. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  6. Effect of Relative Arrangement of Cationic and Lipophilic Moieties on Hemolytic and Antibacterial Activities of PEGylated Polyacrylates

    Directory of Open Access Journals (Sweden)

    Ashish Punia

    2015-10-01

    Full Text Available Synthetic amphiphilic polymers have been established as potentially efficient agents to combat widespread deadly infections involving antibiotic resistant superbugs. Incorporation of poly(ethylene glycol (PEG side chains into amphiphilic copolymers can reduce their hemolytic activity while maintaining high antibacterial activity. Our study found that the incorporation of PEG has substantially different effects on the hemolytic and antibacterial activities of copolymers depending on structural variations in the positions of cationic centers relative to hydrophobic groups. The PEG side chains dramatically reduced the hemolytic activities in copolymers with hydrophobic hexyl and cationic groups on the same repeating unit. However, in case of terpolymers with cationic and lipophilic groups placed on separate repeating units, the presence of PEG has significantly lower effect on hemolytic activities of these copolymers. PEGylated terpolymers displayed substantially lower activity against Staphylococcus aureus (S. aureus than Escherichia coli (E. coli suggesting the deterring effect of S. aureus’ peptidoglycan cell wall against the penetration of PEGylated polymers. Time-kill studies confirmed the bactericidal activity of these copolymers and a 5 log reduction in E. coli colony forming units was observed within 2 h of polymer treatment.

  7. Effect of antibacterial/adhesive approaches on bonding durability of fiber posts cemented with self-etch resin cement.

    Science.gov (United States)

    Shafiei, Fereshteh; Memarpour, Mahtab; Vafamand, Narges; Mohammadi, Mahsa

    2017-09-01

    Longevity of post-retained restoration is highly depended on bonding stability of fiber post (FP) to root dentin. This study evaluated the effect of different antibacterial/adhesive approaches on bonding durability of FPs luted into root canal with a self-etch cement. Seventy-two human maxillary central incisor roots were divided into six groups after endodontic treatment, based on the antibacterial/adhesive treatments as follows: 1)ED primer II (ED, control); 2) Clearfil Protect Bond (PB); 3) 2% chlorhexidine (CH) pretreatment + ED primer II (CH+ED); 4) CH-incorporated into ED primer II (CH in ED); 5) CH pretreatment + Clearfil SE Bond (CH+SE); and 6)CH-incorporated into SE primer (CH in SE). The FPs were then cemented using PanaviaF2.0. After micro-slicing the bonded root dentin, a push-out bond strength (PBS) test was performed immediately or after two years of water storage. Data were analyzed using ANOVA and post hoc Tukey tests (α=0.05). The effects of antibacterial/adhesive approach, time and interaction between the main factors were significant ( p =0.01). There was no significant difference between the immediate groups, except between the CH+ED group (the lowest PBS) and PB and CH in SE groups (the highest PBS) ( p ≤0.03). After aging, the same difference was observed ( p ≤0.02); the control group exhibited a significantly lower PBS compared to the other groups ( p ≤0.01), except for CH+ED. Aging significantly decreased PBS of all the groups ( p ≤0.01); the control group exhibited the highest reduction. CH incorporated into self-etch primers or in pretreatment step prior to two-step self-etch adhesive and antibacterial adhesive could improve bond stability of self-etch cemented fiber post. However, none of these was capable of inhibiting bond degradation over time. Key words: Push-out bond strength, Fiber post, Chlorhexidine.

  8. Isojacareubin from the Chinese herb Hypericum japonicum: potent antibacterial and synergistic effects on clinical methicillin-resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Zuo, Guo-Ying; An, Jing; Han, Jun; Zhang, Yun-Ling; Wang, Gen-Chun; Hao, Xiao-Yan; Bian, Zhong-Qi

    2012-01-01

    Through bioassay-guided fractionation of the extracts from the aerial parts of the Chinese herb Hypericum japonicum Thunb. Murray, Isojacareubin (ISJ) was characterized as a potent antibacterial compound against the clinical methicillin-resistant Staphylococcus aureus (MRSA). The broth microdilution assay was used to determine the minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of ISJ alone. The results showed that its MICs/MBCs ranged from 4/16 to 16/64 μg/mL, with the concentrations required to inhibit or kill 50% of the strains (MIC(50)/MBC(50)) at 8/16 μg/mL. Synergistic evaluations of this compound with four conventional antibacterial agents representing different types were performed by the chequerboard and time-kill tests. The chequerboard method showed significant synergy effects when ISJ was combined with Ceftazidime (CAZ), Levofloxacin (LEV) and Ampicillin (AMP), with the values of 50% of the fractional inhibitory concentration indices (FICI(50)) at 0.25, 0.37 and 0.37, respectively. Combined bactericidal activities were also observed in the time-kill dynamic assay. The results showed the ability of ISJ to reduce MRSA viable counts by log(10)CFU/mL at 24 h of incubation at a concentration of 1 × MIC were 1.5 (LEV, additivity), 0.92 (CAZ, indifference) and 0.82 (AMP, indifference), respectively. These in vitro anti-MRSA activities of ISJ alone and its synergy with conventional antibacterial agents demonstrated that ISJ enhanced their efficacy, which is of potential use for single and combinatory therapy of patients infected with MRSA.

  9. Effect of strong electrolytes on edible oils part III: viscosity of canola ...

    African Journals Online (AJOL)

    Effect of strong electrolytes on the viscosity of canola oil in 1,4 dioxane was undertaken. The viscosity of oil in 1,4 dioxane was found to increase with the concentration of oil and decrease with rise in temperature. Strong electrolytes reduce the rate of flow of oil in 1,4 dioxane. It was noted that amongst these electrolytes, ...

  10. Anomalous Josephson effect in semiconductor nanowire with strong spin-orbit interaction and Zeeman effect

    Science.gov (United States)

    Yokoyama, Tomohiro; Eto, Mikio; Nazarov, Yuli

    2014-03-01

    We theoretically investigate the Josephson junction using quasi-one dimensional semiconductor nanowires with strong spin-orbit (SO) interaction, e.g., InSb. First, we examine a simple model using a single scatterer to describe the elastic scattering due to impurities and SO interaction in the normal region.[1] The Zeeman effect is taken into account by the spin-dependent phase shift of electron and hole through the system. The interplay between SO interaction and Zeeman effect results in a finite supercurrent even when the phase difference between two superconductors is zero. Moreover, the critical current depends on its current direction if more than one conduction channel is present in the nanowire. Next, we perform a numerical simulation by the tight-binding model for the nanowire to confirm our simple model. Then, we show that a spin-dependent Fermi velocity due to the SO interaction causes the anomalous Josephson effect.

  11. The effects of sodium hypochlorite and chlorhexidine irrigants on the antibacterial activities of alkaline media against Enterococcus faecalis.

    Science.gov (United States)

    Ma, Jinglei; Tong, Zhongchun; Ling, Junqi; Liu, Hongyan; Wei, Xi

    2015-07-01

    Sodium hypochlorite (NaOCl), chlorhexidine (CHX) and calcium hydroxide are common intracanal medicaments. The present study aimed to evaluate the effects of NaOCl and CHX on the antibacterial activities of alkaline media against Enterococcus faecalis. The survival rates of planktonic and biofilm E. faecalis were evaluated by plate counts after 1 min of pretreatment with NaOCl and CHX, and time-kill assays were then used to assess subsequent pH alkaline challenges. Dead and living cells in the E. faecalis biofilm were assessed with SYTO 9 and PI staining in combination with confocal laser scanning microscopy following exposure to NaOCl or CHX and subsequent alkaline challenges by common root canal irrigation and dressing procedures. One minute of pretreatment with 2% CHX, 0.2% CHX, or 5.25% NaOCl in combination with a subsequent alkaline challenge significantly decreased planktonic E. faecalis survival rates, but pretreatment with 1% NaOCl did not. The E. faecalis biofilm survival rates were reduced in the subsequent alkaline challenge following CHX pretreatment but gradually increased following NaOCl pretreatment. Similarly, CLSM analysis revealed that the greatest proportions of dead E. faecalis cells in the biofilms were presented in the CHX and alkaline treatment group. CHX might be more effective in improving the antibacterial activities of alkaline root canal medicaments against E. faecalis than NaOCl during routine root canal therapy procedures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Antibacterial and anti-adhesion effects of the silver nanoparticles-loaded poly(L-lactide) fibrous membrane

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shen [Department of Orthopaedics, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai 200233 (China); Zhao, Jingwen [Orthopedic Institute, Soochow University, 708 Renmin Road, Suzhou, Jiangsu 215007 (China); School of Biomedical Engineering and Med-X Research Institute, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai 200030 (China); Ruan, Hongjiang; Wang, Wei [Department of Orthopaedics, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai 200233 (China); Wu, Tianyi [Department of Orthopaedic Surgery, 2nd Affiliated hospital of Nanjing Medical University, Nanjing Medical University, 121 Jiang Jia Yuan, Nanjing 210011 (China); Cui, Wenguo, E-mail: wgcui80@hotmail.com [Orthopedic Institute, Soochow University, 708 Renmin Road, Suzhou, Jiangsu 215007 (China); School of Biomedical Engineering and Med-X Research Institute, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai 200030 (China); Fan, Cunyi, E-mail: fancunyi888@hotmail.com [Department of Orthopaedics, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai 200233 (China)

    2013-04-01

    The complications of tendon injury are frequently compromised by peritendinous adhesions and tendon sheath infection. Physical barriers for anti-adhesion may increase the incidence of postoperative infection. This study was designed to evaluate the potential of silver nanoparticles (AgNPs)-loaded poly(L-lactide) (PLLA) electrospun fibrous membranes to prevent adhesion formation and infection. Results of an in vitro drug release study showed that a burst release was followed by sustained release from electrospun fibrous membranes with a high initial silver content. Fewer fibroblasts adhered to and proliferated on the AgNP-loaded PLLA electrospun fibrous membranes compared with pure PLLA electrospun fibrous membrane. In the antibacterial test, the AgNP-loaded PLLA electrospun fibrous membranes can prevent the adhesion of Gram-positive Staphylococcus aureus and Staphylococcus epidermidis and Gram-negative Pseudomonas aeruginosa. Taken together, these results demonstrate that AgNP-loaded PLLA electrospun fibrous membranes have the convenient practical medical potential of reduction of infection and adhesion formation after tendon injury. - Highlights: ► Silver nanoparticles are directly electrospun into PLLA fibrous membrane. ► Long-lasting release of Ag + ions is achieved. ► Cytotoxicity of silver ions benefits the anti-proliferation of physical barriers. ► Broad anti-microbial effect of drug-loaded fibrous membrane is revealed. ► Antibacterial and anti-adhesion effects of the physical barriers are combined.

  13. The Effect of Silver Nanoparticles Size, Produced Using Plant Extract from Arbutus unedo, on Their Antibacterial Efficacy

    Directory of Open Access Journals (Sweden)

    Nicholas Skandalis

    2017-07-01

    Full Text Available Silver nanoparticles (AgNPs have been demonstrated to restrain bacterial growth, while maintaining minimal risk in development of bacterial resistance and human cell toxicity that conventional silver compounds exhibit. Several physical and chemical methods have been reported to synthesize AgNPs. However, these methods are expensive and involve heavy chemical reduction agents. An alternative approach to produce AgNPs in a cost-effective and environmentally friendly way employs a biological pathway using various plant extracts to reduce metal ions. The size control issue, and the stability of nanoparticles, remain some of the latest challenges in such methods. In this study, we used two different concentrations of fresh leaf extract of the plant Arbutus unedo (LEA as a reducing and stabilizing agent to produce two size variations of AgNPs. UV-Vis spectroscopy, Dynamic Light Scattering, Transmission Electron Microscopy, and zeta potential were applied for the characterization of AgNPs. Both AgNP variations were evaluated for their antibacterial efficacy against the gram-negative species Escherichia coli and Pseudomonas aeruginosa, as well as the gram-positive species Bacillus subtilis and Staphylococcus epidermidis. Although significant differences have been achieved in the nanoparticles’ size by varying the plant extract concentration during synthesis, the antibacterial effect was almost the same.

  14. Effect of soft segment crystallization and hard segment physical crosslink on shape memory function in antibacterial segmented polyurethane ionomers.

    Science.gov (United States)

    Zhu, Y; Hu, J; Yeung, K

    2009-11-01

    Shape memory polyurethane (SMPU) ionomers containing constant 75 wt.% soft segment content were synthesized using poly(epsilon-caprolactone)diol, 4,4'-diphenylmethane diisocyanate, 1,4-butanediol and/or N,N-bis(2-hydroxyethyl)-isonicotinamide. To introduce substrate bonding antibacterial activity, pyridinium was prepared through a neutralization reaction using 1-iodooctane as neutralization agent. For the SMPU ionomer film obtained, tensile testing at 70 degrees C and dynamic mechanical analysis suggests that, at temperatures>T(ms) (the melting point of soft segments), 6.72 and 29.55 mol.% pyridinium within hard segments significantly decreased the mechanical properties such as the stress at 100% elongation (70 degrees C), the initial modulus (70 degrees C) and the elastic modulus (75-110 degrees C). Cyclic tensile investigation demonstrated that the two factors, soft segment crystallization and hard segment physical crosslink, play a very important role in shape memory function in SMPU ionomers. For the each individual specimen, the fixity ratio increased, and the recovery ratio decreased with the extension of cooling time. After sufficient cooling time, the fixity ratio of all specimens can reach a high value (approximately 95%). Owing to the disrupted physical crosslink in the sample containing 29.55 mol.% pyridinium, the crystallization rate of soft segments has less effect on shape fixity. Therefore, a high fixity ratio (93.8%) can be achieved in a short cooling time (30 s). In the control sample, the fixity ratio is only 73.7% after 30 s cooling. In addition, the admirable substrate bonding antibacterial activity of prepared SMPU ionomers was verified using standards AACTT 147 and ASTM E2149 in comparison with the control sample. The antibacterial activity of SMPU ionomers on Gram-positive bacteria (Staphylococcus aureus) is significant, and the rate of reduction of bacteria is 100%; the antibacterial activity on Gram-negative bacteria (Klebsiella pneumoniae

  15. Antibacterial and Cytotoxic Activity of Compounds Isolated from Flourensia oolepis

    Directory of Open Access Journals (Sweden)

    Mariana Belén Joray

    2015-01-01

    Full Text Available The antibacterial and cytotoxic effects of metabolites isolated from an antibacterial extract of Flourensia oolepis were evaluated. Bioguided fractionation led to five flavonoids, identified as 2′,4′-dihydroxychalcone (1, isoliquiritigenin (2, pinocembrin (3, 7-hydroxyflavanone (4, and 7,4′-dihydroxy-3′-methoxyflavanone (5. Compound 1 showed the highest antibacterial effect, with minimum inhibitory concentration (MIC values ranging from 31 to 62 and 62 to 250 μg/mL, against Gram-positive and Gram-negative bacteria, respectively. On further assays, the cytotoxic effect of compounds 1–5 was determined by MTT assay on acute lymphoblastic leukemia (ALL and chronic myeloid leukemia (CML cell lines including their multidrug resistant (MDR phenotypes. Compound 1 induced a remarkable cytotoxic activity toward ALL cells (IC50 = 6.6–9.9 μM and a lower effect against CML cells (IC50 = 27.5–30.0 μM. Flow cytometry was used to analyze cell cycle distribution and cell death by PI-labeled cells and by Annexin V/PI staining, respectively. Upon treatment, 1 induced cell cycle arrest in the G2/M phase accompanied by a strong induction of apoptosis. These results describe for the first time the antibacterial metabolites of F. oolepis extract, with 1 being the most effective. This chalcone also emerges as a selective cytotoxic agent against sensitive and resistant leukemic cells, highlighting its potential as a lead compound.

  16. Potentiating the antibacterial effect of silver nanospheres by surface-capping with chlorhexidine gluconate

    Energy Technology Data Exchange (ETDEWEB)

    Priyadarshini, Balasankar Meera; Fawzy, Amr S., E-mail: denasfmf@nus.edu.sg [National University of Singapore, Discipline of Oral Sciences, Faculty of Dentistry (Singapore)

    2017-04-15

    In this work, the commercial polyvinylpyrrolidone (PVP)-capped silver nanospheres (Ag-NSP) were surface decorated with chlorhexidine gluconate (CHXg) for potentiating the antibacterial properties of Ag-NSP. Different formulations of CHXg-loaded Ag-NSP (Ag-NSP/CHXg) were prepared by varying the incubation times (0.5, 1.5, and 3 h). A thorough characterization of Ag-NSP/CHXg nanospheres has been carried out by dynamic light scattering (DLS), transmission electron microscopy (TEM), energy-dispersive surface elemental composition spectral analysis (SEM/EDX), Fourier transform infrared spectroscopy (FTIR), percentage (%) CHXg loading efficiency (LE), in vitro CHXg and Ag{sup +} ion release, antibacterial/biofilm inhibition assay, and human mesenchymal stem cells (hMSCs) cytotoxicity evaluation. DLS measured nanospheres to be <160 nm and indicated that CHXg treatment drastically shifted the surface charge from negative to high positive values, with homogenous distribution. TEM revealed spherical Ag-NSP/CHXg nanospheres with a clearly visible surface coating of CHXg. FTIR confirmed association of CHXg with Ag-NSP nanospheres, whereas SEM/EDX data verified presence of spectral peaks specific to silver (Ag), CHXg, and PVP. The %LE gradually increased with increasing incubation times. In vitro CHXg release exhibited a bi-phasic fashion showing maximum release of ~74.83 ± 20.67% from Ag-NSP/CHXg-3h at 14 days. A slow release of Ag{sup +} ions was detected; however, the surface decoration of Ag-NSP substantially hampered/restricted the liberation of ions. Agar well diffusion, MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl) -2H–tetrazolium), and crystal violet assay suggested good antibacterial/antibiofilm activity of Ag-NSP/CHXg that correlated with the increasing %LE of nanospheres. hMSCs cytotoxicity study showed low toxicity properties of all nanosphere formulations, except for Ag-NSP/CHXg-3h, affecting the cell viability at all

  17. Strong Effect of Azodye Layer Thickness on RM-Stabilized Photoalignment

    Science.gov (United States)

    2017-05-21

    Strong Effect of Azodye Layer Thickness on RM-Stabilized Photoalignment Colin McGinty*, Valerie Finnemeyer**, Robert Reich**, Harry Clark...vertical alignment on these substrates. For the thinner BY layers, we do not see this strong evidence of out of plane reorientation. The out of...In this report we show the surprising effect that thin azodye layers demonstrate improved stability over those that are thicker. Figure 6

  18. The effect of seasons on Brazilian red propolis and its botanical source: chemical composition and antibacterial activity.

    Science.gov (United States)

    Bueno-Silva, Bruno; Marsola, Alexandre; Ikegaki, Masaharu; Alencar, Severino M; Rosalen, Pedro L

    2017-06-01

    The aim of this study was to evaluate the effect of seasons on the chemical composition and antibacterial activity of Brazilian red propolis (BRP) and its plant source. BRP was collected from Maceio, Alagoas state, north-east of Brazil, during one year. Chemical composition was determined by physicochemical analyses and HPLC while antimicrobial activity was assessed against Streptococcus mutans, Streptococcus sobrinus, Staphylococcus aureus and Actinomyces naeslundii by determining the minimal inhibitory and bactericidal concentrations (MIC and MBC, respectively). The comparative chemical profiles varied quantitatively according to the collection period. Formononetin was the most abundant compound in both propolis and resin, while isoliquiritigenin, (3S)-neovestitol, (3S)-vestitol are suggested to be responsible for antimicrobial activity of Brazilian red propolis. MIC varied from 15.6 to 125 μg/mL, whereas MBC varied from 31.2 to 500 μg/mL. Therefore, season in which propolis and its botanical source are collected indeed influences their chemical compositions, resulting in variations in their antibacterial activity.

  19. Antibacterial study of the medium chain fatty acids and their 1-monoglycerides: individual effects and synergistic relationships.

    Science.gov (United States)

    Batovska, Daniela I; Todorova, Iva T; Tsvetkova, Iva V; Najdenski, Hristo M

    2009-01-01

    The antibacterial activity of the medium chain fatty acids and their 1-monoglycerides was evaluated towards several Gram-positive strains belonging to the genera Staphylococcus, Corynebacterium, Bacillus, Listeria and Streptococcus. The 1-monoglycerides were more active than the fatty acids with monolaurin being the most active compound. Interesting effects were observed when the streptococcal strain Streptococcus pyogenes was used as a test microorganism. First, blocking of the hydroxyl groups of the glycerol moiety of monolaurin led to a compound with remarkable antibacterial activity (MIC, 3.9 microg/ml). Secondly, synergistic relationships were observed between monolaurin and monocaprin as well as between monolaurin and the poorly active lauric acid when their two component mixtures were examined. The mixtures in which one of the components was 2-fold more predominant than the other one were much more active than the pure components taken individually. Moreover, the presence of the components in ratio 1:1 was disadvantageous. Synergistic relationships were also found between monolaurin and monomyristin towards Staphylococcus aureus 209 when monomyristin was in the same quantity as monolaurin or in shortage.

  20. ANTIBACTERIAL AND BIOCHEMICAL EFFECTS OF ETHANOL LEAF EXTRACT OF SENNA HIRSUTA MILL USING ANIMAL MODEL-MICE

    Directory of Open Access Journals (Sweden)

    Fred Coolborn Akharaiyi

    2015-02-01

    Full Text Available This study was carried out to investigate the in-vitro and in-vivo antibacterial and biochemical activities of 50, 100 and 200mg.mL-1 concentrations of ethanol leaf extract of Senna hirsuta (hairy senna against seven human pathogenic bacteria species namely: Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Enterococcus faecium, Bacillus cereus and Salmonella typhi. The in-vitro bioassay revealed the leaf extracts of valuable antibacterial activity where zones of inhibition ranging from 12.1mm to 39.1mm were observed on the test bacteria species. Among the test bacteria, K. pneumoniae was the most inhibited and S. typhi the least inhibited. On mice infection with the bacteria species for three days, decrease in weight of mice was observed. The in-vivo therapeutic use of the extracts in mice infected with the bacteria pathogens resulted to weight gain of the mice and other physiological changes that indicated health improvement of the mice and was also of hepatoprotective potential. The in-vivo antioxidant assay exhibited satisfactory therapeutic effects where improvement in aspartate aminotransferase (AST, alanine aminotransferase (ALT, and alkaline phosphatase (ALP status of mice was observed on comparing results of the positive and negative controls.

  1. Biogenic nanoparticles bearing antibacterial activity and their synergistic effect with broad spectrum antibiotics: Emerging strategy to combat drug

    Directory of Open Access Journals (Sweden)

    Syed Baker

    2017-01-01

    Full Text Available The present study emphasizes on synthesis of bimetallic silver–gold nanoparticles from cell free supernatant of Pseudomonas veronii strain AS41G inhabiting Annona squamosa L. The synthesized nanoparticles were characterized using hyphenated techniques with UV–Visible spectra ascertained absorbance peak between 400 and 800 nm. Possible interaction of biomolecules in mediating and stabilization of nanoparticles was depicted with Fourier transform infrared spectroscopy (FTIR. X-ray diffraction (XRD displayed Bragg’s peak conferring the 100, 111, 200, and 220 facets of the face centered cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. Size and shape of the nanoparticles were determined using Transmission electron microscopy (TEM microgram with size ranging from 5 to 50 nm forming myriad shapes. Antibacterial activity of nanoparticles against significant human pathogens was conferred with well diffusion assay and its synergistic effect with standard antibiotics revealed 87.5% fold increased activity with antibiotic “bacitracin” against bacitracin resistant strains Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae followed by kanamycin with 18.5%, gentamicin with 11.15%, streptomycin with 10%, erythromycin with 9.7% and chloramphenicol with 9.4%. Thus the study concludes with biogenic and ecofriendly route for synthesizing nanoparticles with antibacterial activity against drug resistant pathogens and attributes growing interest on endophytes as an emerging source for synthesis of nanoparticles.

  2. Antibacterial effect of oregano essential oil alone and in combination with antibiotics against extended-spectrum beta-lactamase-producing Escherichia coli.

    Science.gov (United States)

    Si, Hongbin; Hu, Jinqiang; Liu, Zhichang; Zeng, Zhen-ling

    2008-07-01

    In this paper, we studied the antibacterial effects of oregano essential oil (OEO) both alone, using a twofold dilution method, and combined with antibiotics, using a checkerboard microtitre assay, against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. The result indicated that multiple drug-resistant E. coli was very sensitive to OEO and polymycin; their minimal inhibitory concentration values are 0.5 microL mL(-1) and 0.8 microg mL(-1). The antibacterial effects of OEO in combination with kanamycin were independent against E. coli, with fractional inhibitory concentration (FIC) indices of 1.5. The antibacterial effects of OEO combined with amoxicillin, polymycin, and lincomycin showed an additive effect against E. coli, with FIC indices in the range of 0.625-0.750. The antibacterial effects of OEO in combination with fluoroquinolones, doxycycline, lincomycin, and maquindox florfenicol displayed synergism against E. coli, with FIC indices ranging from 0.375 to 0.500. The combination of OEO with fluoroquinolones, doxycycline, lincomycin, and maquindox florfenicol to treat infections caused by ESBL-producing E. coli may lower, to a great extent, the effective dose of these antibiotics and thus minimize the side effects of antibiotics. This is the first report on OEO against ESBL-producing E. coli.

  3. Evaluation of the Antibacterial Effects of Flavonoid Combination from the Leaves ofDracontomelon daoby Microcalorimetry and the Quadratic Rotary Combination Design.

    Science.gov (United States)

    Li, Yang; Xia, Houlin; Wu, Mingquan; Wang, Jiabo; Lu, Xiaohua; Wei, Shizhang; Li, Kun; Wang, Lifu; Wang, Ruilin; Zhao, Pan; Zhao, Yanling; Xiao, Xiaohe

    2017-01-01

    Skin infectious disease is a common public health problem due to the emergence of drug-resistant bacteria caused by the antibiotic misuse. Dracontomelon dao (Blanco) Merr. et Rolfe, a traditional Chinese medicine, has been used for the treatment of various skin infectious diseases over 1000 of years. Previous reports have demonstrated that the leaves of D. dao present favorable antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus , and Bacillus subtitles . The flavonoids are the main components of the ethyl acetate extract of D. dao leaf. However, the correlation between flavonoids and antibacterial activities is yet to be determined. In this study, the combined antibacterial activities of these flavonoids were investigated. Three samples with the different concentrations of flavonoids (S1-S3) were obtained. By microcalorimetric measurements, the results showed that the IC 50 value of S2 was lower than those of S1 and S3. The contents of main flavonoids (including Luteolin, L-Epicatechin, Cianidanol, and Quercetin) in S1-S3 were various, confirmed by the method of the Ultra High Performance Liquid Chromatography (UPLC). Based on the method of quadratic general rotary unitized design, the antibacterial effect of single flavonoid, and the potential synergistic effects between Luteolin and Quercetin, Luteolin and Cianidanol were calculated, which were also proved by microcalorimetric analysis. The antibacterial activities of main flavonoids were Luteolin > Cianidanol > Quercetin > L-Epicatechin. Meanwhile, the synergistic effects of Luteolin and Cianidanol ( P L + C = 1.425), Quercetin and Luteolin ( P L + Q = 1.129) on anti-microbial activity were validated. Finally, we found that the contents of Luteolin, L-Epicatechin, Cianidanol, Quercetin were 1061.00-1061.00, 189.14-262.86, 15,990.33-16,973.62, 6799.67-7662.64 ng·ml -1 respectively, with the antibacterial rate over 60.00%. In conclusion, this study could provide

  4. In vitro antibacterial effect of Withania somnifera root extract on Escherichia coli

    Directory of Open Access Journals (Sweden)

    Mamta Kumari

    2015-01-01

    Full Text Available Aim: The aim was to investigate antibacterial activity of Withania somnifera (Ashwagandha, an Indian traditional medicinal plant against Escherichia coli O78, a pathogenic strain. Materials and Methods: Two-fold serial dilutions of 20% aqueous W. somnifera root (WSR extract were inoculated with E. coli O78 @ 1x107 colony forming units grown in nutrient broth. Following inoculation, turbidity optical density was measured by spectrophotometer at 600 nm in all the tubes at 0, 2, 4, 6 and 8 h of incubation at 37°C. Result: The results revealed that the maximum inhibition of bacterial growth was observed at 1:8 dilution of WSR extract. The highest dilution of the extract that showed inhibited growth of the test organism when compared with control was 1:16. Therefore, the minimum inhibitory concentration of aqueous extract of WSR is 1:16. Conclusion: It is concluded that WSR possessed good antibacterial activity, confirming the great potential of bioactive compounds and its rationalizing use in health care.

  5. In vitro antibacterial effect of Withania somnifera root extract on Escherichia coli

    Science.gov (United States)

    Kumari, Mamta; Gupta, R. P.

    2015-01-01

    Aim: The aim was to investigate antibacterial activity of Withania somnifera (Ashwagandha), an Indian traditional medicinal plant against Escherichia coli O78, a pathogenic strain. Materials and Methods: Two-fold serial dilutions of 20% aqueous W. somnifera root (WSR) extract were inoculated with E. coli O78 @ 1*107 colony forming units grown in nutrient broth. Following inoculation, turbidity optical density was measured by spectrophotometer at 600 nm in all the tubes at 0, 2, 4, 6 and 8 h of incubation at 37°C. Result: The results revealed that the maximum inhibition of bacterial growth was observed at 1:8 dilution of WSR extract. The highest dilution of the extract that showed inhibited growth of the test organism when compared with control was 1:16. Therefore, the minimum inhibitory concentration of aqueous extract of WSR is 1:16. Conclusion: It is concluded that WSR possessed good antibacterial activity, confirming the great potential of bioactive compounds and its rationalizing use in health care. PMID:27046997

  6. Trends and correlation of antibacterial usage and bacterial resistance: time series analysis for antibacterial stewardship in a Chinese teaching hospital (2009-2013).

    Science.gov (United States)

    Zou, Y M; Ma, Y; Liu, J H; Shi, J; Fan, T; Shan, Y Y; Yao, H P; Dong, Y L

    2015-04-01

    The purpose of this investigation was to describe the effect of antibacterial stewardship and evaluate the trends and correlation of antibacterial resistance and usage from 2009 to 2013 in a tertiary-care teaching hospital in northwest China. Antibacterial usage was expressed as defined daily doses per 100 patients per day (DDDs/100 PDs). Hospital-wide population-level data and time series analysis were used to evaluate the trends and determine associations between antibacterial exposure and acquisition of resistance. Yearly consumption of overall antibacterials significantly decreased from 66.54 to 28.08 DDDs/100 PDs (β = -10.504, p resistant rates of the five most frequently isolated species (including Escherichia coli, Acinetobacter baumannii, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae) significantly decreased or remained stable, and none of them showed a statistically significant upward trend. The medical quality indicators got better or remained stable. Autoregressive integrated moving average (ARIMA) models demonstrated that the monthly resistance rate of P. aeruginosa to imipenem was strongly correlated with antipseudomonal carbapenems usage (β = 34.94, p antibacterial use paralleled the improved bacterial resistance without deteriorating medical quality indicators during antimicrobial stewardship. It also suggests that optimum antibiotic use is necessary to alleviate the threat posed by resistant microorganisms at the hospital level.

  7. Evaluation of the Antioxidative, Antibacterial, and Anti-Inflammatory Effects of the Aloe Fermentation Supernatant Containing Lactobacillus plantarum HM218749.1.

    Science.gov (United States)

    Jiang, Meixiu; Deng, Kan; Jiang, Chunling; Fu, Mingui; Guo, Chunlan; Wang, Xiaolei; Wang, Xin; Meng, Fanjing; Yang, Shaoguo; Deng, Keyu; Chen, Tingtao; Xin, Hongbo

    2016-01-01

    Little work is done to develop Aloe vera (AV) using probiotics. To explore the potential benefits, the antioxidant effects and the antibacterial effects on foodborne pathogens of Aloe fermentation supernatant were evaluated in vitro. Our results indicated that the Aloe fermentation supernatant fermented by Lactobacillus plantarum HM218749.1 had very strong scavenging capacities of the DPPH (86%), O2 (•-) (85%), (•)OH (76%), and Fe(2+) chelation (82%) and reducing powers (242.5 mg/L), and the inhibition zones for Salmonella typhimurium, Salmonella enteritidis, Shigella flexneri, Escherichia coli, Listeria monocytogenes, S. dysenteriae 301, Staphylococcus aureus Cowan1, and Propionibacterium acnes were 16, 15, 19, 20, 21, 20, and 27 mm. Moreover, the low concentration of Aloe fermentation supernatant had significantly reduced the production of IL-1β, TNF-α, and IL-6 in both mRNA and protein levels (P Aloe fermentation supernatant can be used as functional beverage or cosmetic ingredients to guard human intestinal health, delaying senescence, and prevent chronic diseases.

  8. THE ANTIBACTERIAL EFFECT OF SOME MEDICINAL PLANTS (INULA VISCOSA, ANACYCLUS VALENTINUS AND THEIR SYNERGISTIC INTERACTION WITH ANTIBIOTIC DRUGS

    Directory of Open Access Journals (Sweden)

    K. Side Larbi

    2016-05-01

    Full Text Available With the emergence of multidrug-resistant organisms, combining medicinal plants with synthetic medicines against resistant bacteria becomes necessary. In this study, Synergism between plant extracts (methanolic extract and essential oils of Inula viscosa and Anacyclus valentinus and two commonly used antibiotics (gentamycin, oxacillin were investigated on three bacterian strains (E. coli, Bacillus subtilis, Staphylococcus aureus. In the first time, the antibacterial effect of extracts alone was tested against 7 strains by disc diffusion and microdilution methods. The minimum inhibitory concentrations of methanolic extracts ranged between 6.25 and 50mg/ml while that of the essential oils varied between 12.5 and 100µL/mL. Interactions extracts /antibiotics and extracts/extracts by checkboard. The results show that the synergistic effect of combinations plant extracts/antibiotics was more important than extracts/extracts.

  9. Synthesis and biological evaluation of benzazepine oxazolidinone antibacterials.

    Science.gov (United States)

    Johnson, Paul D; Aristoff, Paul A; Zurenko, Gary E; Schaadt, Ronda D; Yagi, Betty H; Ford, Charles W; Hamel, Judith C; Stapert, Douglas; Moerman, Judy K

    2003-12-01

    Novel benzazepine oxazolidinone antibacterials were synthesized and evaluated against clinically relevant susceptible and resistant organisms. The effect of ring nitrogen position and N-substitution on antibacterial activity is examined.

  10. Effect of silver-supported materials on the mechanical and antibacterial properties of reinforced acrylic resin composites

    International Nuclear Information System (INIS)

    Han, Zhihui; Zhu, Bangshang; Chen, Rongrong; Huang, Zhuoli; Zhu, Cailian; Zhang, Xiuyin

    2015-01-01

    Highlights: • The novel Novaron-nano-ZrO 2 –ABW/PMMA composites was synthesized. • Nano-ZrO 2 and ABWs could increase the mechanical behavior of this composites. • Novaron had synergistic effect to improve the composites mechanical property and the 4 wt% was the optimal proportion. • Novaron could improve the antibacterial properties through their direct contact with the bacteria. • The composites did not have an adverse affect on cell viability. - Abstract: The aim of this study was to investigate the effect of silver-supported material (Novaron (N)) in acrylic resin (poly(methyl methacrylate) (PMMA)) composites, which reinforced with zirconium dioxide nanoparticles (nano-ZrO 2 ) and aluminum borate whiskers (ABWs), on the mechanical behavior, antibacterial properties and cytotoxicity. Silanized ABWs (4 wt%) and nano-ZrO 2 (2 wt%) were mixed with PMMA powder to obtain nano-ZrO 2 –ABW/PMMA matrices. Various amounts of Novaron particles were incorporated into the matrices and the pure PMMA to test the flexural strength. In addition, Streptococcus mutans (S. mutans) and Canidia albicans (C. albicans) biofilms on the specimen surface and in the culture medium were investigated for metabolic activity and colony-forming units (CFUs). Extracts taken in the cell culture medium of the specimens were used to evaluate cell viability. Results showed that the silanized nano-ZrO 2 and ABWs could improve the flexural strength of composites compared with the pure PMMA. Novaron itself had no mechanical function for composites while it had synergistic effect when it mixed with silanized nano-ZrO 2 and ABWs. And when 4 wt% (N-4) Novaron mixed in nano-ZrO 2 –ABW/PMMA composites, flexural strength achieved an increase of 44%, getting the maximum value. For the antibacterial properties, the values of MTT and CFUs of S. mutans and C. albicans biofilms on the composites surface were greatly reduced (p < 0.05) with the higher proportion of Novaron, and no significant

  11. Rapid green synthesis of silver nanoparticles from Chrysanthemum indicum L and its antibacterial and cytotoxic effects: an in vitro study

    Directory of Open Access Journals (Sweden)

    Arokiyaraj S

    2014-01-01

    Full Text Available Selvaraj Arokiyaraj,1 Mariadhas Valan Arasu,2 Savariar Vincent,3 Nyayirukannaian Udaya Prakash,4 Seong Ho Choi,5 Young-Kyoon Oh,1 Ki Choon Choi,2 Kyoung Hoon Kim1,61Department of Animal Nutrition and Physiology, National Institute of Animal Science, Rural Development Administration, Suwon, Republic of Korea; 2Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration, Seonghwan-Eup, Cheonan-Si, Chungnam, Republic of Korea; 3Center for Environmental Research and Development, Loyola College, Chennai, India; 4Research and Development, Vel Tech Dr RR and Dr SR Technical University, Chennai, India; 5Department of Animal Science, Chungbuk National University, Chungbuk, Republic of Korea; 6Department of Animal Science, Seoul National University, Pyeongchang, Republic of KoreaAbstract: The present work reports a simple, cost-effective, and ecofriendly method for the synthesis of silver nanoparticles (AgNPs using Chrysanthemum indicum and its antibacterial and cytotoxic effects. The formation of AgNPs was confirmed by color change, and it was further characterized by ultraviolet–visible spectroscopy (435 nm. The phytochemical screening of C. indicum revealed the presence of flavonoids, terpenoids, and glycosides, suggesting that these compounds act as reducing and stabilizing agents. The crystalline nature of the synthesized particles was confirmed by X-ray diffraction, as they exhibited face-centered cubic symmetry. The size and morphology of the particles were characterized by transmission electron microscopy, which showed spherical shapes and sizes that ranged between 37.71–71.99 nm. Energy-dispersive X-ray spectroscopy documented the presence of silver. The antimicrobial effect of the synthesized AgNPs revealed a significant effect against the bacteria Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Additionally, cytotoxic assays showed no toxicity of AgNPs toward 3T3 mouse embryo

  12. Nontrivial effects of high-frequency excitation for strongly damped mechanical systems

    DEFF Research Database (Denmark)

    Fidlin, Alexander; Thomsen, Jon Juel

    Some nontrivial effects are investigated, which can occur if strongly damped mechanical systems are subjected to strong high-frequency (HF) excitation. The main result is a theoretical prediction, supported by numerical simulation, that for such systems the (quasi-)equilibrium states can change...... that can be substantial (depending on the strength of the HF excitation) for finite values of the damping. The analysis is focused on the differences between the classic results for weakly damped systems, and new effects for which the strong damping terms are responsible. The analysis is based...... on a slightly modified averaging technique, and includes an elementary example of an elliptically excited pendulum for illustration, alongside with a generalization to a broader class of strongly damped dynamical systems with HF excitation. As an application example, the nontrivial behavior of a classical...

  13. Nontrivial effects of high-frequency excitation for strongly damped mechanical systems

    DEFF Research Database (Denmark)

    Fidlin, Alexander; Thomsen, Jon Juel

    2008-01-01

    Some non-trivial effects are investigated, which can occur if strongly damped mechanical systems are subjected to strong high-frequency (HF) excitation. The main result is a theoretical prediction, supported by numerical simulation, that for such systems the (quasi-)equilibrium states can change...... that can be substantial depending on the strength of the HF excitation) for finite values of the damping. The analysis is focused on the differences between the classic results for weakly damped systems, and new effects for which the strong damping terms are responsible. The analysis is based on a slightly...... modified averaging technique, and includes an elementary example of an elliptically excited pendulum for illustration, alongside with a generalization to a broader class of strongly damped dynamical systems with HF excitation. As an application example, the nontrivial behavior of a classical optimally...

  14. <strong>Effectiveness of Orthoses and Foot Training in patients with Patellofemoral Pain and hyperpronationstrong>

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kaalund, Søren; Christensen, Marianne

    of treatment with functional foot orthoses, exercises, or orthoses with exercises. The intrinsic pedal muscles play an important role in support of the medial longitudinal arch. (2) There are however very little information of the effect from specific foot exercise as an imperative part of exercise program...... adolescent females (3). Soft foot orhtoses in addition to an exercise program resulted in significantly greater improvements in pain than treatment with flat insoles and exercises over eight weeks. A study from 2004 by Wiener-Ogilvie & Jones (4) found however no difference in outcome between 8 weeks...... to PFPS patients. The purpose of this prospective single blinded randomised study was to determine the effectiveness of a standardized foot training program combined with foot orthoses in patients with patellofemoral pain. This treatment was additional to a regular conservative patellofemoral regime...

  15. Analyzing the antibacterial effects of food ingredients : model experiments with allicin and garlic extracts on biofilm formation and viability of Staphylococcus epidermidis

    NARCIS (Netherlands)

    Wu, Xueqing; Santos, Regiane R; Fink-Gremmels, Johanna

    2015-01-01

    To demonstrate different effects of garlic extracts and their main antibiotic substance allicin, as a template for investigations on the antibacterial activity of food ingredients. Staphylococcus epidermidis ATCC 12228 and the isogenic biofilm-forming strain ATCC 35984 were used to compare the

  16. Discovered acetylcholinesterase inhibition and antibacterial activity of polyacetylenes in tansy root extract via effect-directed chromatographic fingerprints.

    Science.gov (United States)

    Móricz, Ágnes M; Ott, Péter G; Morlock, Gertrud E

    2018-03-30

    The knowledge about the activity of polyacetylenes was extended by their new acetylcholinesterase inhibition and antibacterial activity against plant pathogenic bacteria. For this discovery, an utmost streamlined workflow, which we consider to be of high potential in the field of natural product or superfood search was developed. It demonstrates the combined power of biological, biochemical and chemical fingerprints. Bioactive components of tansy (Tanacetum vulgare L.) root extract were profiled and identified by high-performance thin-layer chromatography hyphenated with in situ effect-directed analysis, chemical derivatizations and high-resolution mass spectrometry (HPTLC-UV/Vis/FLD-EDA-HRMS). The effect-directed profiling was performed using four bacterial bioassays including two plant pathogens, an antioxidant assay and acetyl- and butyrylcholinesterase inhibitory assays. The chromatographic, spectral and powerful mass spectrometric study of zones that exerted substantial antibacterial and/or antioxidant and/or acetylcholinesterase inhibitory effects allowed these multi-potent zones to be identified as polyacetylenes. Five polyacetylene compounds were assigned to be 2-non-1-ene-3,5,7-triynyl-3-vinyl-oxirane, 2-(2,4-hexadiynylidene)-3,4-epoxy-1,6-dioxaspiro[4.5]decane, trans- and cis-2-(2,4-hexadiynylidene)-1,6-dioxaspiro[4.5]dec-3-ene and tetradeca-2,4,6-triine-8-en-12-one. This study clearly showed the advantage of the combined use of different ionization sources, i.e. electrospray ionization via an elution-head based interface and also the Direct Analysis in Real Time interface, for HRMS analysis of compounds from the same class with very similar chromatographic behavior and polarity. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. In situ neutralisation of the antibacterial effect of 0.2% Chlorhexidine on salivary microbiota: Quantification of substantivity.

    Science.gov (United States)

    Quintas, V; Prada-López, I; Donos, N; Suárez-Quintanilla, D; Tomás, I

    2015-08-01

    To quantify the substantivity of a single 0.2% Chlorhexidine mouthwash in saliva after its neutralisation with tooth-brushing and 1% acetic acid, in order to identify the effect of Chlorhexidine substantivity in regard to the re-growing period of the salivary bacteria. Unstimulated saliva samples were collected from a group of 15 healthy individuals at baseline (BS), and then 30s and 1, 3, 5 and 7h after the following protocols were performed: a single sterile water mouthwash (M-WATER) (negative control), a single 0.2% Chlorhexidine mouthwash (M-0.2% CHX) (positive control) and a single 0.2% Chlorhexidine mouthwash followed by a complete and detailed tooth-brushing, and a single 1% acetic acid mouthwash (M-0.2% CHX+NP). The samples were analysed using an epifluorescence microscope in combination with LIVE/DEAD(®) BacLight™ fluorescence solution. After the M-0.2% CHX treatment, the bacterial vitality was significantly lower than BS until 7h (87.6 ± 6.5% vs. 73.6 ± 8.8%; pvitality remained significantly lower until 3h with regard to BS (81.4 ± 3.8% vs. 68.1 ± 10.6%; p=0.001), increasing at 5 and 7h (no differences from BS). The immediate antibacterial effect of a single 0.2% Chlorhexidine mouthwash is so potent that the bacterial population needs more than 3h to return to baseline bacterial vitality levels. The substantivity of a 0.2% Chlorhexidine mouthwash is a property that significantly increases its antibacterial activity from the first hour and contributes to extend the duration of its effect by at least double. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. HONEYDEW HONEY: CORRELATIONS BETWEEN CHEMICAL COMPOSITION, ANTIOXIDANT CAPACITY AND ANTIBACTERIAL EFFECT

    Directory of Open Access Journals (Sweden)

    OTILIA BOBIS

    2008-10-01

    Full Text Available Selected physico-chemical parameters, total polyphenols, flavonoids, antioxidant and antibacterial activity of honeydew honey samples from Romanian were determined. Regarding the chemical composition, analysed honey samples framed in this type of honey, phenolic content, determined as gallic acid equivalents, presented a mean value of 116.45mg GAE/100 g honey. Total flavonoid content expressed as quercetin equivalents, was 1.53 mg in honeydew honey. Antioxidant activity expressed as % inhibition of a solution of DPPH, ranged between 47.84 and 62.99%. The concentration of honey that inhibit with 50% the DPPH solution was established to be 16.16%. 10 strains of Staphylococcus aureus presented different inhibition percentages when were treatred with a solution of honey. In conclusion, Honeydew honey could be recommended to complement other polyphenol source in human diet and also used in medical treatment.

  19. A novel and green biomaterial based silver nanocomposite hydrogel: synthesis, characterization and antibacterial effect.

    Science.gov (United States)

    Bardajee, Ghasem R; Hooshyar, Zari; Rezanezhad, Habib

    2012-12-01

    In the present study, we report a facile and eco-friendly method for the preparation of a novel silver nanocomposite hydrogel (SNH) based on poly(acrylic acid) (PAA) grafted onto salep as a water soluble polysaccharide backbone. The presence of inorganic silver nanoparticles (nano-Ag) in the hydrogel was confirmed by thermo-gravimetric (TG) analysis. The TEM images illustrated the presence of embedded nano-Ag throughout the hydrogel matrix. In addition, the transmission electron microscopy (TEM) images showed that the formed nano-Ag had an average particle size of 5-10 nm. The potential of obtained SNH was examined for Tetracycline hydrochloride (TH) release in simulated colon conditions. Lastly, the in vitro antibacterial properties of the obtained optimum sample were successfully evaluated against gram-negative and gram-positive bacteria. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Computing effective properties of nonlinear structures exposed to strong high-frequency loading at multiple frequencies

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2006-01-01

    Effects of strong high-frequency excitation at multiple frequencies (multi-HFE) are analyzed for a class of generally nonlinear systems. The effects are illustrated for a simple pendulum system with a vibrating support, and for a parametrically excited flexible beam. For the latter, theoretical...

  1. Antibacterial effect of urushiol onE. faecalisas a root canal irrigant.

    Science.gov (United States)

    Kim, Sang-Wan; Shin, Dong-Hoon

    2017-02-01

    The purpose of this study was to compare the antibacterial activity of urushiol against Enterococcus faecalis ( E. faecalis ) to that of NaOCl. The canals of thirty two single rooted human teeth were instrumented with Ni-Ti files (ProTaper Next X1, X2, X3, Dentsply). A pure culture of E. faecalis ATCC 19433 was prepared in sterile brain heart infusion (BHI) broth. The teeth were submerged in the suspension of E. faecalis and were incubated at 37℃ for 7 days to allow biofilm formation. The teeth were randomly divided into three experimental groups according to the irrigant used, and a negative control group where no irrigant was used ( n = 8). Group 1 used physiologic normal saline, group 2 used 6% NaOCl, and group 3 used 10 wt% urushiol solution. After canal irrigation, each sample was collected by the sequential placement of 2 sterile paper points (ProTaper NEXT paper points, size X3, Dentsply). Ten-fold serial dilutions on each vials, and 100 µL were cultured on a BHI agar plate for 8 hours, and colony forming unit (CFU) analysis was done. The data were statistically analyzed using Kruskal-Wallis and Mann-whitney U tests. Saline group exhibited no difference in the CFU counts with control group, while NaOCl and urushiol groups showed significantly less CFU counts than saline and control groups ( p < 0.05). The result of this study suggests 10% urushiol and 6% NaOCl solution had powerful antibacterial activity against E. faecalis when they were used as root canal irrigants.

  2. Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study.

    Science.gov (United States)

    Soleimanpour, Saman; Sedighinia, Fereshteh Sadat; Safipour Afshar, Akbar; Zarif, Reza; Ghazvini, Kiarash

    2015-01-01

    In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05). No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts.

  3. Enhanced activity of lysozyme-AgNP conjugate with synergic antibacterial effect without damaging the catalytic site of lysozyme.

    Science.gov (United States)

    Ernest, Vinita; Gajalakshmi, Sekar; Mukherjee, Amitava; Chandrasekaran, Natarajan

    2014-10-01

    The conjugation of silver nanoparticles (AgNPs) with biomolecules such as oligosaccharides, DNA, proteins has attracted great attention of scientists recently. In this study, lysozyme-AgNP conjugates were evaluated for its synergic antimicrobial effect. AgNPs were synthesized and characterized using UV-Visible, X-ray diffraction analysis (XRD) and atomic force microscopy (AFM). AgNP (0-1 mM) was interacted with lysozyme for multi-spectrophotometric studies. Lysozyme was immobilized on AgNP at different ratios and the resulting nano-bio-conjugate was tested against Escherichia coli for potent synergic antibacterial effects. A surface plasmon peak at 420 nm confirmed the presence of AgNPs and spherical to oval-shaped AgNPs were observed by AFM. The particle size was calculated to be 25 nm by XRD analysis. The maximum immobilization efficiency (98%) was achieved at 0.01:1 ratio of enzyme:AgNP. UV-Visible and fluorescence spectral studies revealed the binding of AgNPs to lysozyme by the formation of ground-state complex and the binding parameters were calculated. Circular dichroism studies confirmed decrease by 11% in the α-helical and 29.32% in β-sheets of lysozyme upon AgNP interaction. FTIR spectra revealed the binding of AgNP through thiol (-SH) linkages of lysozyme. Our results showed that the antimicrobial activity of lysozyme-AgNP conjugate was enhanced up to 86% decrease in the cell growth. In summary, the immobilization of lysozyme on AgNP has yielded a nano-bio-conjugate with synergistic antibacterial properties.

  4. Attribution of antibacterial and antioxidant activity of Cassia tora extract toward its growth promoting effect in broiler birds

    Directory of Open Access Journals (Sweden)

    Jyoti Sahu

    2017-02-01

    Full Text Available Aim: The study was conducted to evaluate the attribution of antibacterial and antioxidant activity of methanolic extract of Cassia tora toward its growth promoting effect in broiler birds. Materials and Methods: A limit test was conducted for C. tora extract in Wistar albino rats. Phytochemical screening of methanolic extract of leaves of C. tora was carried out. In-vitro antibacterial activity was measured by disc diffusion method. 1-day-old Ven Cobb broiler birds (n=90 were randomly allocated into three groups consisting of three replicates with 10 birds in each group. The birds of group T1 (Control received basal diet, whereas birds of group T2 (Standard received an antibiotic (Lincomycin at 0.05% in feed. The birds of group T3 (Test received Cassia tora extract (CSE at 0.4 g/L in drinking water in addition to basal diet. The treatment was given to birds of all the groups for 6 weeks. Antioxidant activity of C. tora was determined in blood of broiler birds. Cumulative body weight gain, feed intake, feed conversion ratio (FCR, dressing percent, and organ weight factor were evaluated to determine growth performance in broiler birds. Results: Phytochemicals in C. tora were screened. Sensitivity to Escherichia coli and resistant to Staphylococcus aureus and Pseudomonas aeruginosa was observed in in-vitro antibacterial activity test. At the end of 6th week, antioxidant activity reflected significantly (p≤0.05 lower level of erythrocyte malondialdehyde and higher levels of reduced glutathione (GSH and GSH peroxidase in broiler birds of group T2 and T3 as compared to broiler of group T1. Mean cumulative body weight gain of birds of T2 and T3 were significantly (p≤0.05 higher as compared to T1. Mean FCR of birds of group T3 decreased significantly than group T1. Conclusion: Supplementation of C. tora leaves extract at 0.4 g/L in drinking water improved growth performance in broiler birds due to its antimicrobial and antioxidant activity

  5. Attribution of antibacterial and antioxidant activity ofCassia toraextract toward its growth promoting effect in broiler birds.

    Science.gov (United States)

    Sahu, Jyoti; Koley, K M; Sahu, B D

    2017-02-01

    The study was conducted to evaluate the attribution of antibacterial and antioxidant activity of methanolic extract of Cassia tora toward its growth promoting effect in broiler birds. A limit test was conducted for C. tora extract in Wistar albino rats. Phytochemical screening of methanolic extract of leaves of C. tora was carried out. In-vitro antibacterial activity was measured by disc diffusion method. 1-day-old Ven Cobb broiler birds (n=90) were randomly allocated into three groups consisting of three replicates with 10 birds in each group. The birds of group T1 (Control) received basal diet, whereas birds of group T2 (Standard) received an antibiotic (Lincomycin at 0.05% in feed). The birds of group T3 (Test) received Cassia tora extract (CSE) at 0.4 g/L in drinking water in addition to basal diet. The treatment was given to birds of all the groups for 6 weeks. Antioxidant activity of C. tora was determined in blood of broiler birds. Cumulative body weight gain, feed intake, feed conversion ratio (FCR), dressing percent, and organ weight factor were evaluated to determine growth performance in broiler birds. Phytochemicals in C. tora were screened. Sensitivity to Escherichia coli and resistant to Staphylococcus aureus and Pseudomonas aeruginosa was observed in in-vitro antibacterial activity test. At the end of 6 th week, antioxidant activity reflected significantly (p≤0.05) lower level of erythrocyte malondialdehyde and higher levels of reduced glutathione (GSH) and GSH peroxidase in broiler birds of group T2 and T3 as compared to broiler of group T1. Mean cumulative body weight gain of birds of T2 and T3 were significantly (p≤0.05) higher as compared to T1. Mean FCR of birds of group T3 decreased significantly than group T1. Supplementation of C. tora leaves extract at 0.4 g/L in drinking water improved growth performance in broiler birds due to its antimicrobial and antioxidant activity. Therefore, it could be used as an alternative to antibiotic growth

  6. Attribution of antibacterial and antioxidant activity of Cassia tora extract toward its growth promoting effect in broiler birds

    Science.gov (United States)

    Sahu, Jyoti; Koley, K. M.; Sahu, B. D.

    2017-01-01

    Aim: The study was conducted to evaluate the attribution of antibacterial and antioxidant activity of methanolic extract of Cassia tora toward its growth promoting effect in broiler birds. Materials and Methods: A limit test was conducted for C. tora extract in Wistar albino rats. Phytochemical screening of methanolic extract of leaves of C. tora was carried out. In-vitro antibacterial activity was measured by disc diffusion method. 1-day-old Ven Cobb broiler birds (n=90) were randomly allocated into three groups consisting of three replicates with 10 birds in each group. The birds of group T1 (Control) received basal diet, whereas birds of group T2 (Standard) received an antibiotic (Lincomycin at 0.05% in feed). The birds of group T3 (Test) received Cassia tora extract (CSE) at 0.4 g/L in drinking water in addition to basal diet. The treatment was given to birds of all the groups for 6 weeks. Antioxidant activity of C. tora was determined in blood of broiler birds. Cumulative body weight gain, feed intake, feed conversion ratio (FCR), dressing percent, and organ weight factor were evaluated to determine growth performance in broiler birds. Results: Phytochemicals in C. tora were screened. Sensitivity to Escherichia coli and resistant to Staphylococcus aureus and Pseudomonas aeruginosa was observed in in-vitro antibacterial activity test. At the end of 6th week, antioxidant activity reflected significantly (p≤0.05) lower level of erythrocyte malondialdehyde and higher levels of reduced glutathione (GSH) and GSH peroxidase in broiler birds of group T2 and T3 as compared to broiler of group T1. Mean cumulative body weight gain of birds of T2 and T3 were significantly (p≤0.05) higher as compared to T1. Mean FCR of birds of group T3 decreased significantly than group T1. Conclusion: Supplementation of C. tora leaves extract at 0.4 g/L in drinking water improved growth performance in broiler birds due to its antimicrobial and antioxidant activity. Therefore, it

  7. In situ green synthesis and characterization of sericin-silver nanoparticle composite with effective antibacterial activity and good biocompatibility.

    Science.gov (United States)

    He, Huawei; Tao, Gang; Wang, Yejing; Cai, Rui; Guo, Pengchao; Chen, Liqun; Zuo, Hua; Zhao, Ping; Xia, Qingyou

    2017-11-01

    -silver nanoparticle composite had long-term stability, effective antibacterial activity and good biocompatibility. This novel sericin-silver nanoparticle composite has shown great potentials for biomedical application such as antibacterial agent and wound care. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. SUNYAEV-ZEL'DOVICH EFFECT OBSERVATIONS OF STRONG LENSING GALAXY CLUSTERS: PROBING THE OVERCONCENTRATION PROBLEM

    International Nuclear Information System (INIS)

    Gralla, Megan B.; Gladders, Michael D.; Marrone, Daniel P.; Bayliss, Matthew; Carlstrom, John E.; Greer, Christopher; Hennessy, Ryan; Koester, Benjamin; Leitch, Erik; Sharon, Keren; Barrientos, L. Felipe; Bonamente, Massimiliano; Bulbul, Esra; Hasler, Nicole; Culverhouse, Thomas; Hawkins, David; Lamb, James; Gilbank, David G.; Joy, Marshall; Miller, Amber

    2011-01-01

    We have measured the Sunyaev-Zel'dovich (SZ) effect for a sample of 10 strong lensing selected galaxy clusters using the Sunyaev-Zel'dovich Array (SZA). The SZA is sensitive to structures on spatial scales of a few arcminutes, while the strong lensing mass modeling constrains the mass at small scales (typically <30''). Combining the two provides information about the projected concentrations of the strong lensing clusters. The Einstein radii we measure are twice as large as expected given the masses inferred from SZ scaling relations. A Monte Carlo simulation indicates that a sample randomly drawn from the expected distribution would have a larger median Einstein radius than the observed clusters about 3% of the time. The implied overconcentration has been noted in previous studies and persists for this sample, even when we take into account that we are selecting large Einstein radius systems, suggesting that the theoretical models still do not fully describe the observed properties of strong lensing clusters.

  9. Surveying the Effect of the Phenol Compounds on Antibacterial Activity of Herbal Extracts: In vitro Assessment of Herbal Extracts in Fasa-Fars Province

    Directory of Open Access Journals (Sweden)

    Elahe Ahmadi

    2016-09-01

    Full Text Available Background & Objectives: Due to increase in  bacterial drug resistance, discovering new antibacterial compounds is really important. The objective of this study is to evaluate the phenol compounds effect on antibacterial activity of herbal extracts of Fasa-Fars province in vitro. Materials & Methods: The antibacterial activity of 26 plants was studied by disk diffusion, well, and MIC methods in compare with 13 standard antibiotics against S. aureus and E. coli as control bacteria. Measurement of phenol compounds were performed by Seevers and Daly colorimetric methods using Folin-ciocalteu indicator. Results: Inhibition zone of bacterial growth  against S. aureus in well and disk methods were 32 and 22 mm in using Zataria multiflora, respectively .And there were 23 and 16 mm against E. coli in Zataria multiflora, respectively. Less effects and inhibition zones, less than 15mm on both strains, were seen in using  Saturina hortensis, Cinamomum zeylanicum, ­Artemisia absinthium, ­Urtica dioica, Carum carvi L. cyminum Cuminum, Achillea fragrantissimia, Marticaria chamomilla, Zingiber officinale, Origanum majorana, and Plantago psyllium. Most effective MIC results, 7.8 µg/ml, were related to the extracts of Zataria multiflora, Carum copticum L. Rosmarinus officinalis L., and Laurus nobilis L. Phenol compound amounts were approximately between 66.51±1.9 and 233.15±5.1 mg/gr extract in Zataria multiflora and Plantago psyllium, respectively. Conclusion: Results of antibacterial activity of extracts and relation with phenol compound amounts indicate the antibacterial effect of phenol compounds in herbal extracts.

  10. Antibacterial activity of Phyllantus emblica, Coriandrum sativum, Culinaris medic, Lawsonia alba and Cucumis sativus.

    Science.gov (United States)

    Khan, Dawood Ali; Hassan, Fouzia; Ullah, Hanif; Karim, Sabiha; Baseer, Abdul; Abid, Mobasher Ali; Ubaidi, Muhammad; Khan, Shujaat Ali; Murtaza, Ghulam

    2013-01-01

    Present study deals with the demonstration of the antibacterial activity of very common medicinal plants of Pakistani origin i.e., Phyllantus emblica, Coriandrum sativum, Culinaris medic, Lawsonia alba and Cucumis sativus. The extracts were prepared in crude form by the use of hydro-alcoholic solution and were screened for antibacterial activity against various bacterial species by disk diffusion method. Assay was performed using clinical isolates of B. cereus, S. aureus, P. aeruginosa and E. coli. Crude extract of Phyllantus emblica fruit exhibited strong activity against standard cultures of all studied bacteria. Lawsonia alba showed good activity against standard cultures of all the used microorganisms. Coriandrum sativum was effective only against Bacillus cereus, while Cucumis sativus and Culinaris medic showed poor activity against Pseudomonas aeruginosa only. Hence, Phyllantus emblica exhibited strong antibacterial activity against a wide range of bacteria it means that Phyllantus emblica extract contains some compounds which have broad spectrum of bactericidal activity.

  11. Using strong nonlinearity and high-frequency vibrations to control effective properties of discrete elastic waveguides

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Thomsen, Jon Juel; Snaeland, Sveinn Orri

    2008-01-01

    The aim of this article is to investigate how highfrequency (HF) excitation, combined with strong nonlinear elastic material behavior, influences the effective material or structural properties for low-frequency excitation and wave propagation. The HF effects are demonstrated on discrete linear...... spring-mass chains with non-linear inclusions. The presented analytical and numerical results suggest that the effective material properties can easily be altered by establishing finite amplitude HF standing waves in the non-linear regions of the chain....

  12. Effective hadronic lagrangian in the strong coupling expansion of lattice QCD with Susskind fermions

    International Nuclear Information System (INIS)

    Azakov, S.I.; Aliev, E.S.

    1987-12-01

    The effective hadronic action in lattice QCD with U(N) and SU(N) gauge groups and with Susskind fermions is constructed in the framework of the strong coupling approximation. For arbitrary finite (odd) N (in particular N=3) we find an effective potential, vacuum expectation value of the (χ-barχ) and an effective action for the physical meson field π(x). (author). 19 refs

  13. Photocatalytic antibacterial effect of ZnO nanoparticles into coaxial electrospun PCL fibers to prevent infections from skin injuries

    Science.gov (United States)

    Prado-Prone, G.; Silva-Bermúdez, P.; García-Macedo, J. A.; Almaguer-Flores, A.; Ibarra, C.; Velasquillo-Martínez, C.

    2017-02-01

    Antibacterial studies of inorganic nanoparticles (nps) have become important due to the increased bacterial resistance against antibiotics. We used Zinc oxide nanoparticles (ZnO nps), which possess excellent photocatalytic properties with a wide band gap (Eg), are listed as "generally recognized as safe" by the Food and Drug Administration (FDA) and have shown antibacterial activity (AA) against many bacterial strains. The AA of ZnO nps is partly attributed to the production of Reactive Oxygen Species (ROS) by photocatalysis. When ZnO nps in aqueous media are illuminated with an energy water and Oxygen molecules to generate hydroxyl-radical (OH• ), superoxide-radical (O2 •- ) and hydrogen-peroxide (H2O2). These ROS induce cell membrane damage resulting in cell death. However, the application of inorganic nps in medical treatments is limited due to the possible long-term side effects of nps release. To prevent its release, ZnO nps were dispersed into Polycaprolactone (PCL) fibers obtained by electrospinning technique. To optimize the use of ZnO nps concentration, we developed coreshell coaxial electrospun fibers where the core corresponded to PCL and the shell to a mixture of ZnO nps/PCL. Thus, ZnO nps were only dispersed on the surface of the fibers increasing its superficial contact area. We evaluated the AA against E. coli of different electrospun ZnO nps/PCL fibers under two different conditions: UVA pre-illumination and darkness. Preliminary results suggest that the AA against E. coli is better when electrospun ZnO nps/PCL were preilluminated with UVA than under darkness conditions.

  14. The Antibacterial Effect of Nd:YAG Laser Treatment of Teeth with Apical Periodontitis: A Randomized Controlled Trial.

    Science.gov (United States)

    Granevik Lindström, Maria; Wolf, Eva; Fransson, Helena

    2017-06-01

    The aim of this blind, in vivo, randomized controlled trial was to evaluate the antibacterial effect of Nd:YAG laser irradiation in endodontic treatment of single-rooted teeth with apical periodontitis. The hypothesis was that mechanical enlargement of the root canal and Nd:YAG laser irradiation would yield more negative bacterial samples than conventional treatment. Forty-one patients (45 teeth) were allocated to the laser (n = 22) or control (n = 23) group. The teeth in the laser group were instrumented, irrigated with saline, and irradiated with Nd:YAG laser according to a standard protocol. The teeth in the control group were similarly instrumented but irrigated with 1% unbuffered sodium hypochlorite and 15% EDTA solution. Bacterial samples were taken before and after treatment, blinded, and immediately sent for culturing and analysis. The initial bacterial samples were positive in 20 of 22 teeth in the laser group and 18 of 23 (P = .414) in the control group. After the initial treatment, negative bacterial samples were found in 11 teeth in the laser group and 13 (P = .768) in the control group. After 2 to 4 days with no antibacterial dressing in the root canals, 5 teeth in the laser group and 9 (P = .337) in the control group yielded negative bacterial samples. After intervention, neither the test group nor the control group yielded predictable negative bacterial samples. Thus, the results failed to verify the hypothesis that Nd:YAG laser irradiation would yield significantly more negative bacterial samples than conventional irrigation with 1% unbuffered sodium hypochlorite solution. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Antibacterial activity of fig leaf (Ficus carica Linn. extract against Enterococcus faecalis and its cytotoxicity effects on fibroblast cells

    Directory of Open Access Journals (Sweden)

    Intan Nirwana

    2018-03-01

    Full Text Available Background: Enterococcus faecalis is one of the bacteria that commonly found in root canal and pulp infection after root canal treatment. Sodium hypochlorite is the most widely used root canal irrigation, but it has toxic properties if exposed to periradicular tissues. It is necessary to develop an alternative for root canal irrigation. Fig leaf (Ficus carica Linn. extract contains active substances such as flavonoid, tannin, and terpenoid which have been known for their antibacterial potency. Aim: This study aimed to determine the minimum bactericidal concentration (MBC of fig leaf (F. carica Linn. extract against E. faecalis and its cytotoxicity on fibroblast cells in vitro. Materials and Methods: A serial dilution method was used to determine the MBC of fig leaf extract on E. faecalis which grown on nutrient agar media. Inoculation was carried out at concentrations that suspected minimum inhibitory concentration (MIC, MBC, concentration between MIC and MBC, and control groups on different nutrient agar. MIC and MBC of fig leaf extract against E. faecalis were known by counting the growth of bacteria colonies on nutrient agar media in CFU/ml. The cytotoxicity of MIC and MBC of the extract acquired were tested using 3-(4,5-dimethylthiazol-2-yl-2,5- diphenyltetrazolium bromide assay, and the results were read using an ELISA reader. Data of E. faecalis colonies were analyzed using Kruskal-Wallis and Mann-Whitney test. Results: The result showed a significant difference among the groups (p<0.05. Fig leaf extract at a concentration of 50% showed no bacterial growth, and cell viability at this concentration was 77.7%. Conclusion: Fig leaf extract has antibacterial effect on E. faecalis with MBC at 50% and not cytotoxic to fibroblast cells.

  16. Anticancer and antibacterial secondary metabolites from the ...

    African Journals Online (AJOL)

    Background: The emergence of multiple-drug resistance bacteria has become a major threat and thus calls for an urgent need to search for new effective and safe anti-bacterial agents. Objectives: This study aims to evaluate the anticancer and antibacterial activities of secondary metabolites from Penicillium sp., ...

  17. What makes a natural clay antibacterial?

    Science.gov (United States)

    Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Port-Peterson, Amisha T.

    2011-01-01

    Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (2+ solubility.

  18. The Effectiveness of Heterotrophic Bacteria Isolated from Dumai Marine Waters of Riau, Used as Antibacterial against Pathogens in Fish Culture

    Science.gov (United States)

    Feliatra, F.; Nursyirwani; Tanjung, A.; Adithiya, DS; Susanna, M.; Lukystyowati, I.

    2018-02-01

    Heterotrophic bacteria have an important role as decomposer of organic compounds (mineralization) derived from industrial waste, decomposition of unconsumed feed, faecal, excretion of fish, and have the ability to inhibit the growth of pathogenic bacteria. We investigated the role of heterotrophic bacteria used as antibacterial against pathogens in fish culture.This research was conducted from January until March 2017. The phylogenitic of the isolated bacterial was determined by 16S rDNA sequences analysis. Antagonism test showed that the bacteria had the ability to inhibit the growth of pathogenic bacteria (Vibrio alginolyticus, Aeromonas hydrophila and Pseudomonas sp.) Three isolates (Dm5, Dm6 and Dm4) indicated high inhibition zones which were classified into strong category with the average from 10.5 to 11.8 mm toward V. alginolitycus. Other isolates were classified into medium and weak category. Based on DNA analysis of heterotrophic bacteria isolated from marine waters of industrial area and low salinity of estuarine waters twelve strains of bacteria were identified, and all had highest level of homology to Bacillus sp.,one isolates has similarity to Enterobacter cloacae, other isolates to Clostridium cetobutylicum. Most of isolated bacteria obtained from the waters of industrial area due to it received much of nutrients that very influenced the growth of bacteria.

  19. Antibacterial Characteristics of Lotus-Type Porous Copper

    OpenAIRE

    Lee, Jin-Soo; Lee, Yun-Soo; Kim, Mok-Soon; Hyun, Soong-Keun; Kang, Chang-Ho; So, Jae-Seong; Yoon, Eui-Han

    2013-01-01

    Lotus-type porous copper with long cylindrical pores aligned parallel to the solidification direction was studied for use as an antibacterial material. The antibacterial performance of lotus-type porous copper samples with different specific surface areas against Escherichia coli was investigated. The results confirmed that the antibacterial effect gradually increased with specific surface area. The correlation between the pore structure of lotus-type porous metals and their antibacterial eff...

  20. Antibacterial activity of indium curcumin and indium diacetylcurcumin

    African Journals Online (AJOL)

    Studies on curcumin, the principal element of turmeric powder, have demonstrated several biological actions such as antibacterial activity. Evaluation of new analogs or new compounds of curcumin for their antibacterial effect is interesting for researchers. In this in vitro study, we attempted to test the antibacterial activity of ...

  1. Effect of polymorphism in egg white lysozyme on muramidase and antibacterial activities as well as hatchability in the Japanese quail (Coturnix japonica).

    Science.gov (United States)

    Myint, Si Lhyam; Kinoshita, Keiji; Shimogiri, Takeshi; Ibrahim, Hisham R; Tsusaki, Tomohiro; Tanoue, Tomomi; Kawabe, Kotaro; Maeda, Yoshizane; Okamoto, Shin

    2012-06-01

    Lysozyme is one of the best characterized antimicrobial proteins in egg white. Three phenotypes of egg white lysozyme in Japanese quail, Coturnix japonica, (namely fast; slow; and the combination, FS) were observed by acid polyacrylamide gel electrophoresis. The fast phenotype showed faster mobility on Acid-PAGE than the slow phenotype. Comparison of the coding sequences for lysozyme derived from the slow and fast phenotypes revealed a nonsynonymous SNP at nucleotide position 115 from the translation initiation site, which alters AA sequence of lysozyme. This nonsynonymous SNP converted glutamine (Q) in the slow phenotype to lysine (K) in the fast phenotype at AA residue 21 of mature lysozyme (Q21K). Here, we investigated the effect of these phenotypes on muramidase activity, antibacterial activity, and hatchability. Muramidase activity toward isolated cell walls of Micrococcus lysodeikticus was in the order: fast allozyme > slow allozyme > chicken (Gallus gallus), but no significant difference was found among the 3 (P > 0.05). Antibacterial activity against live Staphylococcus aureus cells was significantly greater for the fast allozyme than the slow allozyme from 20 h after incubation (P lysozyme influences the electrophoretic migration, muramidase activity, and antibacterial activity of the protein, in addition to the hatchability of the eggs. These results demonstrate, for the first time, a significant difference in antibacterial activity and hatchability between 2 lysozyme phenotypes in Japanese quail.

  2. Planning, Instruction, and Assessment: Effective Teaching Practices. James H. Stronge Research-to-Practice Series

    Science.gov (United States)

    Grant, Leslie W.; Hindman, Jennifer; Stronge, James H.

    2010-01-01

    This entry in the James H. Stronge Research-to-Practice Series focuses on specific strategies teachers can use to improve the quality of their instruction. Studies have shown teacher quality to be the top indicator of student achievement, with the effects of good teachers apparent even as students move on to successive grades. In this book, Grant,…

  3. Engineering the Dynamics of Effective Spin-Chain Models for Strongly Interacting Atomic Gases

    DEFF Research Database (Denmark)

    Volosniev, A. G.; Petrosyan, D.; Valiente, M.

    2015-01-01

    We consider a one-dimensional gas of cold atoms with strong contact interactions and construct an effective spin-chain Hamiltonian for a two-component system. The resulting Heisenberg spin model can be engineered by manipulating the shape of the external confining potential of the atomic gas. We...

  4. Effects of interaction imbalance in a strongly repulsive one-dimensional Bose gas

    DEFF Research Database (Denmark)

    Barfknecht, Rafael Emilio; Zinner, Nikolaj Thomas; Foerster, Angela

    2018-01-01

    We calculate the spatial distributions and the dynamics of a few-body two-component strongly interacting Bose gas confined to an effectively one-dimensional trapping potential. We describe the densities for each component in the trap for different interaction and population imbalances. We calculate...

  5. Parity violation effects in the hydrogen atom in the field of a strong electromagnetic wave

    International Nuclear Information System (INIS)

    Labzovsky, L.N.; Mitrushchenkov, A.O.

    1989-01-01

    The parity violation effects in the hydrogen atom in a strong electromagnetic laser field are considered. It is shown that there is the possibility of hyperrate measurements of different constants of the weak interaction in the hydrogen magnetic resonance experiments. (orig.)

  6. Effects of interaction imbalance in a strongly repulsive one-dimensional Bose gas

    DEFF Research Database (Denmark)

    Barfknecht, Rafael Emilio; Zinner, Nikolaj Thomas; Foerster, Angela

    2018-01-01

    We calculate the spatial distributions and the dynamics of a few-body two-component strongly interacting Bose gas confined to an effectively one-dimensional trapping potential. We describe the densities for each component in the trap for different interaction and population imbalances. We calcula...

  7. Non-Oberbeck-Boussinesq effects in strongly turbulent Rayleigh-Bénard convection

    NARCIS (Netherlands)

    Ahlers, Günter; Brown, Eric; Fontenele Araujo Junior, F.; Funfschilling, Denis; Grossmann, Siegfried; Lohse, Detlef

    2006-01-01

    Non-Oberbeck–Boussinesq (NOB) effects on the Nusselt number $Nu$ and Reynolds number $\\hbox{\\it Re}$ in strongly turbulent Rayleigh–Bénard (RB) convection in liquids were investigated both experimentally and theoretically. In the experiments the heat current, the temperature difference, and the

  8. Novel nanocomposites with selective antibacterial action and low cytotoxic effect on eukaryotic cells.

    Science.gov (United States)

    Shweta, Kumari; Manupati, Kanakaraju; Das, Amitava; Jha, Harit

    2016-11-01

    In the present study we synthesized lignin-tetra ethoxysilane (TEOS) nanocomposite and characterized it using UV-spectroscopy, Fourier Transform Infra-red spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Field Emission-Scanning Electron Microscopy (FE-SEM) and Scanning Electron Microscopy (SEM). XRD spectra and SEM micrographs confirmed a relatively high degree of crystallinity (peaks located at lower angle, 2θ=12° and 2θ=22.0°) and porous nature of nanocomposite. The lignin-TEOS nanocomposites depicted antibacterial activity against the test microorganisms (Pseudomonas aerugenosa MTCC 741, Escherichia coli MTCC 739, Bacillus subtilis MTCC 441 and Staphylococcus aureus MTCC 96) whereas at the same concentration did not show any significant cytotoxicity against various tissue-specific cancer cell lines such as breast cancer: MCF-7, MDA-MB-231, MDA-MB-468, BT-549; lung cancer: A-549; prostate cancer: PC-3, Du-145; as well as primary control cells-Human hepatic stellate cells (HHSteCs). The present study suggests the plausible translational role of these nanocomposites as an antimicrobial agent for wound dressings due to its potent antimicrobial activity with low toxicity to non-target eukaryotic cells. Nevertheless, these nanocomposites may also be used as packaging materials due to their antimicrobial activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Biosynthesis, Antibacterial Activity and Anticancer Effects Against Prostate Cancer (PC-3) Cells of Silver Nanoparticles Using Dimocarpus Longan Lour. Peel Extract

    Science.gov (United States)

    He, Yan; Du, Zhiyun; Ma, Shijing; Cheng, Shupeng; Jiang, Sen; Liu, Yue; Li, Dongli; Huang, Huarong; Zhang, Kun; Zheng, Xi

    2016-06-01

    Metal nanoparticles, particularly silver nanoparticles (AgNPs), are developing more important roles as diagnostic and therapeutic agents for cancers with the improvement of eco-friendly synthesis methods. This study demonstrates the biosynthesis, antibacterial activity, and anticancer effects of silver nanoparticles using Dimocarpus Longan Lour. peel aqueous extract. The AgNPs were characterized by UV-vis absorption spectroscopy, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscope (FTIR). The bactericidal properties of the synthesized AgNPs were observed via the agar dilution method and the growth inhibition test. The cytotoxicity effect was explored on human prostate cancer PC-3 cells in vitro by trypan blue assay. The expressions of phosphorylated stat 3, bcl-2, survivin, and caspase-3 were examined by Western blot analysis. The longan peel extract acted as a strong reducing and stabilizing agent during the synthesis. Water-soluble AgNPs of size 9-32 nm was gathered with a face-centered cubic structure. The AgNPs had potent bactericidal activities against gram-positive and gram-negative bacteria with a dose-related effect. AgNPs also showed dose-dependent cytotoxicity against PC-3 cells through a decrease of stat 3, bcl-2, and survivin, as well as an increase in caspase-3. These findings confirm the bactericidal properties and explored a potential anticancer application of AgNPs for prostate cancer therapy. Further research should be focused on the comprehensive study of molecular mechanism and in vivo effects on the prostate cancer.

  10. Heavy quark mass effects and improved tests of the flavor independence of strong interactions

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, P.N. [Univ. of Oxford (United Kingdom); SLD Collaboration

    1998-08-01

    A review is given of latest results on tests of the flavor independence of strong interactions. Heavy quark mass effects are evident in the data and are now taken into account at next-to-leading order in QCD perturbation theory. The strong-coupling ratios {alpha}{sub s}{sup b}/{alpha}{sub s}{sup uds} and {alpha}{sub s}{sup c}/{alpha}{sub s}{sup uds} are found to be consistent with unity. Determinations of the b-quark mass m{sub b} (M{sub Z}) are discussed.

  11. Strong interaction effects in high-Z K sup minus atoms

    Energy Technology Data Exchange (ETDEWEB)

    Batty, C.J.; Eckhause, M.; Gall, K.P.; Guss, P.P.; Hertzog, D.W.; Kane, J.R.; Kunselman, A.R.; Miller, J.P.; O' Brien, F.; Phillips, W.C.; Powers, R.J.; Roberts, B.L.; Sutton, R.B.; Vulcan, W.F.; Welsh, R.E.; Whyley, R.J.; Winter, R.G. (Rutherford-Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom (GB) College of William and Mary, Williamsburg, Virginia 23185 Boston University, Boston, Massachusetts 02215 University of Wyoming, Laramie, Wyoming 82071 California Institute of Technology, Pasadena, California 91125 Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213)

    1989-11-01

    A systematic experimental study of strong interaction shifts, widths, and yields from high-{ital Z} kaonic atoms is reported. Strong interaction effects for the {ital K}{sup {minus}}(8{r arrow}7) transition were measured in U, Pb, and W, and the {ital K}{sup {minus}}(7{r arrow}6) transition in W was also observed. This is the first observation of two measurably broadened and shifted kaonic transitions in a single target and thus permitted the width of the upper state to be determined directly, rather than being inferred from yield data. The results are compared with optical-model calculations.

  12. Auger effect in the presence of strong x-ray pulses

    International Nuclear Information System (INIS)

    Liu Jicai; Sun Yuping; Wang Chuankui; Aagren, Hans; Gel'mukhanov, Faris

    2010-01-01

    We study the role of propagation of strong x-ray free-electron laser pulses on the Auger effect. When the system is exposed to a strong x-ray pulse the stimulated emission starts to compete with the Auger decay. As an illustration we present numerical results for Ar gas with the frequency of the incident x-ray pulse tuned in the 2p 3/2 -4s resonance. It is shown that the pulse propagation is accompanied by two channels of amplified spontaneous emission, 4s-2p 3/2 and 3s-2p 3/2 , which reshape the pulse when the system is inverted. The population inversion is quenched for longer propagation distances where lasing without inversion enhances the Stokes component. The results of simulations show that the propagation of the strong x-ray pulses affect intensively the Auger branching ratio.

  13. Substituted Hydroxyapatites with Antibacterial Properties

    Directory of Open Access Journals (Sweden)

    Joanna Kolmas

    2014-01-01

    Full Text Available Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.

  14. Substituted Hydroxyapatites with Antibacterial Properties

    Science.gov (United States)

    Kolmas, Joanna; Groszyk, Ewa; Kwiatkowska-Różycka, Dagmara

    2014-01-01

    Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency. PMID:24949423

  15. Pure and multi metal oxide nanoparticles: synthesis, antibacterial and cytotoxic properties.

    Science.gov (United States)

    Stankic, Slavica; Suman, Sneha; Haque, Francia; Vidic, Jasmina

    2016-10-24

    Th antibacterial activity of metal oxide nanoparticles has received marked global attention as they can be specifically synthesized to exhibit significant toxicity to bacteria. The importance of their application as antibacterial agents is evident keeping in mind the limited range and effectiveness of antibiotics, on one hand, and the plethora of metal oxides, on the other, along with the propensity of nanoparticles to induce resistance being much lower than that of antibiotics. Effective inhibition against a wide range of bacteria is well known for several nano oxides consisting of one metal (Fe 3 O 4 , TiO 2 , CuO, ZnO), whereas, research in the field of multi-metal oxides still demands extensive exploration. This is understandable given that the relationship between physicochemical properties and biological activity seems to be complex and difficult to generalize even for metal oxide nanoparticles consisting of only one metal component. Also, despite the broad scope that metal oxide nanoparticles have as antibacterial agents, there arise problems in practical applications taking into account the cytotoxic effects. In this respect, the consideration of polymetallic oxides for biological applications becomes even greater since these can provide synergetic effects and unify the best physicochemical properties of their components. For instance, strong antibacterial efficiency specific of one metal oxide can be complemented by non-cytotoxicity of another. This review presents the main methods and technological advances in fabrication of nanostructured metal oxides with a particular emphasis to multi-metal oxide nanoparticles, their antibacterial effects and cytotoxicity.

  16. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth

    OpenAIRE

    Neha Shashikant Dhariwal; Shivayogi M Hugar; Sheetal Harakuni; Suma Sogi; Harsha G Assudani; Laresh Naresh Mistry

    2016-01-01

    Context: In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. Aim: To evaluate the antibacterial effectiveness of sodium hypoch...

  17. Antioxidant/Prooxidant and Antibacterial/Probacterial Effects of a Grape Seed Extract in Complex with Lipoxygenase

    Directory of Open Access Journals (Sweden)

    Veronica Sanda Chedea

    2014-01-01

    Full Text Available In an attempt to determine the antioxidant/prooxidant, antibacterial/probacterial action of flavan-3-ols and procyanidins from grape seeds, pure catechin (CS, and an aqueous grape seed extract (PE, were applied in the absence and presence of pure lipoxygenase (LS or in extract (LE to leucocyte culture, Escherichia coli B41 and Brevibacterium linens, and observed whether there was any effect on lipid peroxidation, cytotoxicity, or growth rate. Short time periods of coincubation of cells with the polyphenols, followed by the exposure to LS and LE, revealed a high level of lipid peroxidation and a prooxidative effect. Longer coincubation and addition of LS and LE resulted in the reversal of the prooxidant action either to antioxidant activity for CS + LS and PE + LS or to the control level for CS + LE and PE + LE. Lipid peroxidation was significantly reduced when cells were exposed to polyphenols over a longer period. Longer exposure of E. coli to CS or PE followed by addition of LS for 3 h resulted in bactericidal activity. Significant stimulatory effect on microbial growth was observed for PE + LS and PE + LE treatments in B. linens, illustrating the potential probacterial activity in B. linens cultures. Lipoxygenase-polyphenols complex formation was found to be responsible for the observed effects.

  18. Antibacterial Effects of the Essential Oils of CommonlyConsumed Medicinal Herbs Using an In Vitro Model.

    NARCIS (Netherlands)

    Sokovic, M.; Glamoclija, J.; Marin, P.D.; Brkic, D.; Griensven, van L.J.L.D.

    2010-01-01

    The chemical composition and antibacterial activity of essential oils from 10 commonly consumed herbs: Citrus aurantium, C. limon, Lavandula angustifolia, Matricaria chamomilla, Mentha piperita, M. spicata, Ocimum basilicum, Origanum vulgare, Thymus vulgaris and Salvia officinalis have been

  19. Synthesis of new antibacterial quaternary ammonium monomer for incorporation into CaP nanocomposite

    Science.gov (United States)

    Zhou, Chenchen; Weir, Michael D.; Zhang, Ke; Deng, Dongmei; Cheng, Lei; Xu, Hockin H. K.

    2013-01-01

    Objectives Composites are the principal material for tooth cavity restorations due to their esthetics and direct-filling capabilities. However, composites accumulate biofilms in vivo, and secondary caries due to biofilm acids is the main cause of restoration failure. The objectives of this study were to: (1) synthesize new antibacterial monomers; and (2) develop nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP) and antibacterial monomer. Methods Two new antibacterial monomers were synthesized: dimethylaminohexane methacrylate (DMAHM) with a carbon chain length of 6, and dimethylaminododecyl methacrylate (DMADDM) with a chain length of 12. A spray-drying technique was used to make NACP. DMADDM was incorporated into NACP nanocomposite at mass fractions of 0%, 0.75%, 1.5%, 2.25% and 3%. A flexural test was used to measure composite strength and elastic modulus. A dental plaque microcosm biofilm model with human saliva as inoculum was used to measure viability, metabolic activity, and lactic acid production of biofilms on composites. Results The new DMAHM was more potent than a previous quaternary ammonium dimethacrylate (QADM). DMADDM was much more strongly antibacterial than DMAHM. The new DMADDM-NACP nanocomposite had strength similar to that of composite control (p > 0.1). At 3% DMADDM in the composite, the metabolic activity of adherent biofilms was reduced to 5% of that on composite control. Lactic acid production by biofilms on composite containing 3% DMADDM was reduced to only 1% of that on composite control. Biofilm colony-forming unit (CFU) counts on composite with 3% DMADDM were reduced by 2-3 orders of magnitude. Significance New antibacterial monomers were synthesized, and the carbon chain length had a strong effect on antibacterial efficacy. The new DMADDM-NACP nanocomposite possessed potent anti-biofilm activity without compromising load-bearing properties, and is promising for antibacterial and remineralizing dental

  20. Evaluation of The Antibacterial Effects of The New Benzothiazole and Tetrahydropyrimidine Derivatives against Streptococcus Iniae, Edwardsiella Tarda and Aeromonas Hydrophila as Some Zoonotic Bacterial Pathogens

    Directory of Open Access Journals (Sweden)

    Reza Aryan

    2016-09-01

    Full Text Available Background & Objective: The novel stronger antibacterial compounds such as the thiazole and pyrimidine derivatives are needed in order to remove the threat of bacterial antibiotic resistance in zoonotic aquatic bacterial pathogens. In this study, we evaluated the inhibitory effect of the new benzothiazole and tetrahydropyrimidine derivatives against three important zoonotic aquatic pathogens including Streptococcus iniae, Edwardsiella tarda and Aeromonas hydrophila. Material & Methods: Benzothiazole and tetrahydropyrimidine derivatives were synthesized and dissolved in DMSO with a concentration of 8129 μg/mL. Then, the disk diffusion and broth microdilution methods were applied to evaluate the antibacterial effects. Results were recorded as the minimum inhibitory concentration (MIC and the growth inhibition zone diameter. Results: The study showed that the two tetrahydropyrimidine derivatives had no inhibition effects on all of the studied bacteria. Moreover, no inhibitory effect was observed from the three banzothiazole derivatives against A. hydrophila. However, the benzothiazole derivatives showed significant inhibitory effect against S. iniae and E. tarda with MIC of 256-1024 µg/mL and the growth inhibition zone diameter of 4.3±0.3-18.2±0.1 mm. Conclusion: The antibacterial effect of the new banzothiazole derivatives was confirmed on S. iniae and E. tarda pathogens for the first time.  

  1. A versatile effect of chitosan-silver nanocomposite for surface plasmonic photocatalytic and antibacterial activity.

    Science.gov (United States)

    Nithya, Arjunan; JeevaKumari, Henry Linda; Rokesh, Karuppannan; Ruckmani, Kandasamy; Jeganathan, Kulandaivel; Jothivenkatachalam, Kandasamy

    2015-12-01

    Chitosan-silver (CS-Ag) nanocomposite was green synthesised without the aid of any external chemical-reducing agents. The synthesised nanocomposite was characterised by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), and zeta potential analyser. The particle size of the synthesised CS-Ag nanocomposite was around 20 nm and was found to be thermally stable in comparison with pure chitosan. The prepared nanocomposite acts as a photocatalyst for dye decolourisation, with a maximum of 81% of methyl orange (MO) decolourisation that occurred under visible light irradiation. The kinetics was found to follow pseudo-first-order according to Langmuir-Hinshelwood (L-H) model. The nanocomposite also proved to be an excellent antimicrobial agent against both Gram-positive and Gram-negative bacteria, possessing a broad spectrum of antimicrobial activity. The zone of inhibition ranged between 16.000 ± 1.000 and 19.333 ± 1.155 (mm), proving its high susceptibility than chitosan itself. The minimum inhibitory concentration (MIC) values were from 8 to 64 μg/mL, whereas the minimum bactericidal concentration (MBC) values ranged from 16 to 128 μg/mL, with the highest antibacterial activity shown against Gram-positive Staphlococcus aureus. This report illustrates the eco-friendly approach for the reduction of silver using chitosan as a reducing agent, and its potential to dye decay and microbial contaminants. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Effectiveness of the antimicrobial removal device, BACTEC 16B medium, and thiol broth in neutralizing antibacterial activities of imipenem, norfloxacin, and related agents.

    Science.gov (United States)

    Weinberg, E; Shungu, D L; Gadebusch, H H

    1984-02-01

    The Antimicrobial Removal Device (ARD), BACTEC 16B medium, and Thiol broth were evaluated for their effectiveness in reducing the activity of imipenem (IPM), cefoxitin, moxalactam, and ceftazidime in blood samples. In addition, the capability of the ARD and Thiol broth to bind norfloxacin and the ARD to bind oxolinic and nalidixic acids in urine samples was investigated. At the highest concentrations of the drugs tested (32 micrograms/ml for the four beta-lactams and 256 micrograms/ml for the three quinolinecarboxylic acids), there was at least a 95% reduction in the in vitro activity of each of the antibacterial agents for treated versus untreated samples. Of the compounds tested in the ARD system, the organic acids were more completely removed than were the beta-lactams. The Thiol broth was more effective than the ARD and the BACTEC 16B medium in inactivating imipenem, but it had no effect on the antibacterial activity of norfloxacin.

  3. ANTIBACTERIAL EFFECT OF GARLIC (ALLIUM SATIVUM) AND GINGER (ZINGIBER OFFICINALE) AGAINST STAPHYLOCOCCUS AUREUS, SALMONELLA TYPHI, ESCHERICHIA COLI AND BACILLUS CEREUS

    OpenAIRE

    Bandna Chand

    2013-01-01

    Antibacterial activity of extracts of Allium sativum (garlic) and Zingiber officinale (ginger) has been evaluated against four different bacteria namely Escherichia coli, Salmonella Typhi, Staphylococcus aureus and Bacillus cereus. Two methods were used to determine the antimicrobial activity of garlic and ginger extracts namely disk diffusion method and agar well diffusion method. Garlic extract exhibited excellent antibacterial activity against all four test organisms while ginger extract s...

  4. In vitro antibacterial effect of calcium hydroxide combined with chlorhexidine or iodine potassium iodide on Enterococcus faecalis.

    Science.gov (United States)

    Sirén, Eva K; Haapasalo, Markus P P; Waltimo, Tuomas M T; Ørstavik, Dag

    2004-08-01

    Several studies have shown a higher success rate of root canal therapy when the canal is free from bacteria at the time of obturation. Treatment strategies that are designed to eliminate this microflora should include agents that can effectively disinfect the root canal. Enterococcus faecalis is often associated with persistent endodontic infections. While in vivo studies have indicated calcium hydroxide to be the most effective all-purpose intracanal medicament, iodine potassium iodide (IKI) and chlorhexidine (CHX) may be able to kill calcium hydroxide-resistant bacteria. Supplementing the antibacterial activity of calcium hydroxide with IPI or CHX preparations was studied in bovine dentine blocks. While calcium hydroxide was unable to kill E. faecalis in the dentine, calcium hydroxide combined with IKI or CHX effectively disinfected the dentine. The addition of CHX or IKI did not affect the alkalinity of the calcium hydroxide suspensions. It may be assumed that combinations also have the potential to be used as long-term medication. Cytotoxicity tests using the neutral red method indicated that the combinations were no more toxic than their pure components.

  5. The Antibacterial Effect of Methanol and Aqueous Extracts of Vaccinium arctostaphylos Fruit on Enteropathogenic Escherichia coli In Vitro

    Directory of Open Access Journals (Sweden)

    Fatemeh Moini

    2016-03-01

    Full Text Available Background and Objectives: Enteropathogenic Escherichia coli strains cause a wide range of gastrointestinal infections, especially in developing countrirs. The aim of this study was to evaluate of the antibacterial effect of methanol and aqueous extracts of Vaccinium arctostaphylos fruit on entropathogenic Escherichia coli in vitro. Methods: In this experimental study, methanol and aqueous extracts of Vaccinium arctostaphylos fruit were prepared by two methods, maceration and soxhlet. Antimicrobial effects of these extracts were examined by agar diffusion method on two strains of Escherichia coli (ATCC: 8739, ATCC: 25922 and 12 clinical strains of enteropathogenic Escherichia coli. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined by microdilution method. Analysis of variance and t-independent tests wee used to comoare the means. Results: All of the studied strains of Escherichia coli were sensitive to the methanol and aqueous extracts of Vaccinium arctostaphylos fruit. The mean zones of inhibition produced by the extracts were obtained in the range of 10.6-18.8 mm. Statistical analysis showed that there is a significant relationship between the increase in extracts’ concentrations and inhibition zone diameters (p<0.001. Also, the values of MIC and MBC were determined to be 50-200mg/ml and 100-400mg/ml, respectively. Conclusion: According to the results of this study, methanol and aqueous extracts of Vaccinium arctostaphylos fruit had inhibitory effect on enteropathogenic Escherichia coli.

  6. Antibacterial evaluation of Salvia miltiorrhizae on Escherichia coli by microcalorimetry coupled with chemometrics.

    Science.gov (United States)

    Ying, Guangyao; Zhang, Shanshan; Hu, Yuli; Yang, Meihua; Chen, Ping; Wu, Xiaoru; Guo, Weiying; Kong, Weijun

    2017-12-01

    For seeking novel antibacterial agents with high efficacy and low toxicity to deal with drug resistance, the effects of Salvia miltiorrhizae from various sources on Escherichia coli were evaluated by microcalorimetry coupled with chemometrics. Firstly, the heat-flow power-time curves of E. coli growth affected by different S. miltiorrhizae samples were recorded. Then, some crucial quantitative thermo-kinetic parameters including growth rate constant, heat-flow power and heat output, etc. were obtained from theses curves and were further investigated by some powerful chemometric techniques including similarity analysis, multivariate analysis of variance, hierarchical clustering analysis and principle component analysis. By analyzing the principle parameters, growth rate constant of the second exponential phase (k 2 ) and the heat-flow output powers of the second highest peak (P 2 ), together with the derived parameter inhibitory ratio (I,  %), it could be quickly concluded that the tested S. miltiorrhizae samples from different sources in China exhibited strong antibacterial effects on E. coli and the samples from Beijing city exhibited the strongest anti-E. coli effects, which might be used as novel and underlying antibacterial candidates for the resistance of E. coli to the existing drugs in practice. This study provides a useful tool and helpful idea to accurately and rapidly evaluate the antibacterial effects of some complex matrices, offering some references for exploring new antibacterial agents.

  7. Comparative study of antibacterial activity of wood-decay fungi and antibiotics

    Directory of Open Access Journals (Sweden)

    A. F. Md. Hassan Iftekhar

    2011-03-01

    Full Text Available The antibacterial effects of three mushrooms extract Ganoderma lucidum, Auricularia auricula, Pleurotus florida were studied against Staphylococcus aureus and Escherichia coli. A. auricula showed significant antibacterial activity against S. aureus. P. florida showed some antibacterial activity while G. lucidum showed no antibacterial activity. None of the extracts showed any activity against E. coli.

  8. DNA Topoisomerases as Targets for Antibacterial Agents.

    Science.gov (United States)

    Hiasa, Hiroshi

    2018-01-01

    DNA topoisomerases are proven therapeutic targets of antibacterial agents. Quinolones, especially fluoroquinolones, are the most successful topoisomerase-targeting antibacterial drugs. These drugs target type IIA topoisomerases in bacteria. Recent structural and biochemical studies on fluoroquinolones have provided the molecular basis for both their mechanism of action, as well as the molecular basis of bacterial resistance. Due to the development of drug resistance, including fluoroquinolone resistance, among bacterial pathogens, there is an urgent need to discover novel antibacterial agents. Recent advances in topoisomerase inhibitors may lead to the development of novel antibacterial drugs that are effective against fluoroquinolone-resistant pathogens. They include type IIA topoisomerase inhibitors that either interact with the GyrB/ParE subunit or form nick-containing ternary complexes. In addition, several topoisomerase I inhibitors have recently been identified. Thus, DNA topoisomerases remain important targets of antibacterial agents.

  9. Strong coupling electrostatics for randomly charged surfaces: antifragility and effective interactions.

    Science.gov (United States)

    Ghodrat, Malihe; Naji, Ali; Komaie-Moghaddam, Haniyeh; Podgornik, Rudolf

    2015-05-07

    We study the effective interaction mediated by strongly coupled Coulomb fluids between dielectric surfaces carrying quenched, random monopolar charges with equal mean and variance, both when the Coulomb fluid consists only of mobile multivalent counterions and when it consists of an asymmetric ionic mixture containing multivalent and monovalent (salt) ions in equilibrium with an aqueous bulk reservoir. We analyze the consequences that follow from the interplay between surface charge disorder, dielectric and salt image effects, and the strong electrostatic coupling that results from multivalent counterions on the distribution of these ions and the effective interaction pressure they mediate between the surfaces. In a dielectrically homogeneous system, we show that the multivalent counterions are attracted towards the surfaces with a singular, disorder-induced potential that diverges logarithmically on approach to the surfaces, creating a singular but integrable counterion density profile that exhibits an algebraic divergence at the surfaces with an exponent that depends on the surface charge (disorder) variance. This effect drives the system towards a state of lower thermal 'disorder', one that can be described by a renormalized temperature, exhibiting thus a remarkable antifragility. In the presence of an interfacial dielectric discontinuity, the singular behavior of counterion density at the surfaces is removed but multivalent counterions are still accumulated much more strongly close to randomly charged surfaces as compared with uniformly charged ones. The interaction pressure acting on the surfaces displays in general a highly non-monotonic behavior as a function of the inter-surface separation with a prominent regime of attraction at small to intermediate separations. This attraction is caused directly by the combined effects from charge disorder and strong coupling electrostatics of multivalent counterions, which dominate the surface-surface repulsion due to

  10. Empty creditors and strong shareholders: The real effects of credit risk trading. Second draft

    OpenAIRE

    Colonnello, Stefano; Efing, Matthias; Zucchi, Francesca

    2016-01-01

    Credit derivatives give creditors the possibility to transfer debt cash flow rights to other market participants while retaining control rights. We use the market for credit default swaps (CDSs) as a laboratory to show that the real effects of such debt unbundling crucially hinge on shareholder bargaining power. We find that creditors buy more CDS protection when facing strong shareholders to secure themselves a valuable outside option in distressed renegotiations. After the start of CDS trad...

  11. Antibacterial Effect of CrO and CoFe2O4 Nanoparticles upon Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Saber Imani

    2011-12-01

    Full Text Available Background & Objectives: The use of metal oxide nanoparticles can be effective to eliminate the bacterial infections, as an alternative to antibiotics. In this study, antibacterial properties of nonmaterials of CrO and CoFe2O4 are investigated against Staphylococcus aureus as a major and prevalent pathogenic bacterium to achieve sterile nano-containers. Materials & Methods: Different concentrations of CrO and CoFe2O4 nanoparticles, (0.2, 0.4, 0.6, 0.8, and 1% of each, were examined with respect to their optical density (OD culture separately. Different percentages of each nanoparticles were also examined together for the best antibacterial combination. Kinetics of Bactericidal of nanoparticles were calculated in two-hour periods and were compared with the power of other common antibiotics. Ratios of MIC/MBC were calculated by Micro dilution method, to demonstrate the bactericidal power of nanoparticles. Results: The best concentration of the nanoparticles with the highest effect of bactericidal was obtained in the presence of 1% concentration of CrO that the OD of S. aureus culture medium had reduced 4/6 times than the control group (p<0/001.Ratio of 70% CrO to 30% CoFe2O4 was the best of the Bacteriostatic properties that OD was reduced 3/3 times than the control group (p<0/05. Best kinetics of bactericidal with survival rate in the presence of 1% CrO and CoFe2O4 were obtained in 24 and 36 hours respectively. In critical concentration of 1% CrO and CoFe2O4 bactericidal power was about 67 and 56 % respectively. The MIC/MBC rate for CrO and CoFe2O4 was obtained 0/2 and 0/4 respectively. Conclusion: The results showed that CrO nanoparticle compared with CoFe2O4 has a higher bactericidal power for S. aureus infection. Therefore, by completion of these experiments and the use of metal oxide nanoparticles complex in sensitive environments such as food storage containers, etc. are suggested.

  12. Effect of a Novel Quaternary Ammonium Methacrylate Polymer (QAMP on Adhesion and Antibacterial Properties of Dental Adhesives

    Directory of Open Access Journals (Sweden)

    Yasmine M. Pupo

    2014-05-01

    control for all evaluated bacterial strains. The use of QAMP in an adhesive system demonstrated effective bond strength, a suitable degree of conversion, and adequate antibacterial effects against oral bacteria, and may be useful as a new approach to provide long-lasting results for dental adhesives.

  13. [Effects of strong reductive approach on remediation of degraded facility vegetable soil].

    Science.gov (United States)

    Zhu, Tong-Bin; Meng, Tian-Zhu; Zhang, Jin-Bo; Cai, Zu-Cong

    2013-09-01

    High application rate of chemical fertilizers and unreasonable rotation in facility vegetable cultivation can easily induce the occurrence of soil acidification, salinization, and serious soil-borne diseases, while to quickly and effectively remediate the degraded facility vegetable soil can considerably increase vegetable yield and farmers' income. In this paper, a degraded facility vegetable soil was amended with 0, 3.75, 7.50, and 11.3 t C x hm(-2) of air-dried alfalfa and flooded for 31 days to establish a strong reductive environment, with the variations of soil physical and chemical properties and the cucumber yield studied. Under the reductive condition, soil Eh dropped quickly below 0 mV, accumulated soil NO3(-) was effectively eliminated, soil pH was significantly raised, and soil EC was lowered, being more evident in higher alfalfa input treatments. After treated with the strong reductive approach, the cucumber yield in the facility vegetable field reached 53.3-57.9 t x hm(-2), being significantly higher than that in un-treated facility vegetable field in last growth season (10.8 t x hm(-2)). It was suggested that strong reductive approach could effectively remediate the degraded facility vegetable soil in a short term.

  14. The in vitro antibacterial effect of iodine-potassium iodide and calcium hydroxide in infected dentinal tubules at different time intervals.

    Science.gov (United States)

    Lin, Shaul; Kfir, Anda; Laviv, Amir; Sela, Galit; Fuss, Zvi

    2009-03-01

    The aim of this study was to evaluate the antibacterial effect of iodine-potassium iodide (IKI) and calcium hydroxide (CH) on dentinal tubules infected with Enterococcus faecalis (E. faecalis) at different time intervals. Hollow cylinders of bovine root dentin (n=45) were infected and divided into three equal groups filled with either IKI or CH and a positive control. After placing each medicament in the infected cylinders for time periods of 10 minutes, 48 hours and 7 days, microbiological samples were analyzed. At the end of each period, four 100 microm thick inner dentin layers (400 microm thick from each specimen) were removed using dental burs of increasing diameters. Dentin powder was cultured on agar plates to quantitatively assess their infection, expressed in colony forming units (cfu). In all layers of the positive control group, heavy bacterial infection was observed. After 10 minutes, IKI reduced the amount of viable bacteria more efficiently than CH, whereas at later time intervals CH showed the best results. For short periods of exposure, IKI has a more efficient antibacterial effect in the dentinal tubules than CH but CH performs better after longer durations of exposure. This research indicates the use of IKI is a better choice for disinfecting the root canal than CH if only a short duration of exposure is used because of its more efficient antibacterial effect. However, if a longer exposure time is used, then CH is a better choice because of its better disinfecting effect over time.

  15. Anti-inflammatory and Antibacterial Effects of Covalently Attached Biomembrane-Mimic Polymer Grafts on Gore-Tex Implants.

    Science.gov (United States)

    Jin, Young Ju; Kang, Sunah; Park, Pona; Choi, Dongkil; Kim, Dae Woo; Jung, Dongwook; Koh, Jaemoon; Jeon, Joohee; Lee, Myoungjin; Ham, Jiyeon; Seo, Ji-Hun; Jin, Hong-Ryul; Lee, Yan

    2017-06-07

    Expanded polytetrafluoroethylene (ePTFE), also known as Gore-Tex, is widely used as an implantable biomaterial in biomedical applications because of its favorable mechanical properties and biochemical inertness. However, infection and inflammation are two major complications with ePTFE implantations, because pathogenic bacteria can inhabit the microsized pores, without clearance by host immune cells, and the limited biocompatibility can induce foreign body reactions. To minimize these complications, we covalently grafted a biomembrane-mimic polymer, poly(2-methacryloyloxylethyl phosphorylcholine) (PMPC), by partial defluorination followed by UV-induced polymerization with cross-linkers on the ePTFE surface. PMPC grafting greatly reduced serum protein adsorption as well as fibroblast adhesion on the ePTFE surface. Moreover, the PMPC-grafted ePTFE surface exhibited a dramatic inhibition of the adhesion and growth of Staphylococcus aureus, a typical pathogenic bacterium in ePTFE implants, in the porous network. On the basis of an analysis of immune cells and inflammation-related factors, i.e., transforming growth factor-β (TGF-β) and myeloperoxidase (MPO), we confirmed that inflammation was efficiently alleviated in tissues around PMPC-grafted ePTFE plates implanted in the backs of rats. Covalent PMPC may be an effective strategy for promoting anti-inflammatory and antibacterial functions in ePTFE implants and to reduce side effects in biomedical applications of ePTFE.

  16. Antibacterial effect of mango (Mangifera indica Linn.) leaf extract against antibiotic sensitive and multi-drug resistant Salmonella typhi.

    Science.gov (United States)

    Hannan, Abdul; Asghar, Samra; Naeem, Tahir; Ikram Ullah, Muhammad; Ahmed, Ijaz; Aneela, Syeda; Hussain, Shabbir

    2013-07-01

    Alternative herbal medicine has been used to treat various infections from centuries. Natural plants contain phytoconstituents having similar chemical properties as of synthetic antibiotics. Typhoid fever is a serious infection and failure of its treatment emerged multi-drug resistant (MDR) bugs of Salmonella typhi. Due to multiple and repeated issues with antibiotics efficacy, it became essential to evaluate biological properties of plants from different geographical origins. Mango leaves have been Reported for various medicinal effects like antioxidant, antimicrobial, antihelminthic, antidiabetic and antiallergic etc. Objective of present study was to investigate anti-typhoid properties of acetone mango leaf extract (AMLE) against antibiotic sensitive and MDR S. typhi isolates. A total of 50 isolates of S. typhi including MDR (n=30) and antibiotic sensitive (n=20) were investigated. Staphylococcus aureus (ATCC 25923) and Salmonella typhimurium (ATCC14028) were used as quality control strains. AMLE was prepared and its antibacterial activity was evaluated by agar well diffusion screening method and minimum inhibitory concentration (MIC), by agar dilution technique. Zone of inhibition (mm) of AMLE against MDR and antibiotic sensitive isolates was 18±1.5mm (Mean±S.D). Zone of S. aureus (ATCC 25923) and S. typhimurium (ATCC14028) was 20±1.5mm (Mean±S.D). MIC of AMLE was Reported in range from 10-50 mg/ml. The present study described the inhibitory effects of mango leaves against S. typhi.

  17. In vitro antileishmanial effects of antibacterial diterpenes from two Ethiopian Premna species: P. schimperi and P. oligotricha

    Science.gov (United States)

    Habtemariam, Solomon

    2003-01-01

    Background Three antibacterial diterpenes: (5R,8R,9S,10R)-12-oxo-ent-3,13(16)-clerodien-15-oic acid (1), 16-hydroxy-clerod-3,13(14)-diene-15,16-olide (2) and ent-12-oxolabda-8,13(16)-dien-15-oic acid (3) were previously isolated form Premna schimperi and P. oligotricha. Since andrographolide and other structurally related diterpenes were shown to have antileishmanial activity, the aim of the present study was to assess the in vitro effect of premna diterpenes against Leishmania aethiopica; the causative agent of cutaneous leishmaniasis in Ethiopia. Results The diterpenes showed potent concentration-dependant suppressive effect on the viability of axenically cultured amastigotes of L. aethiopica. The clerodane diterpenes 1 and 2 were most active (LD50 values 1.08 and 4.12 μg/ml respectively) followed by andrographolide and 3. Compounds 1 and 2 appear to be over 20 and 10-times respectively more selective to leishmania amastigotes than the permissive host cell line, THP-1 cells or the promastigotes stage of the parasites. Conclusion The clerodane diterpenes (1, 2) which were more potent and selective than labdanes (andrographolide and 3) are promising for further studies and/or development. PMID:12793911

  18. Empirical prediction and validation of antibacterial inhibitory effects of various plant essential oils on common pathogenic bacteria.

    Science.gov (United States)

    Akdemir Evrendilek, Gulsun

    2015-06-02

    In this study, fractional compound composition, antioxidant capacity, and phenolic substance content of 14 plant essential oils-anise (Pimpinella anisum), bay leaves (Laurus nobilis), cinnamon bark (Cinnamomum verum), clove (Eugenia caryophyllata), fennel (Foeniculum vulgare), hop (Humulus lupulus), Istanbul oregano (Origanum vulgare subsp. hirtum), Izmir oregano (Origanum onites), mint (Mentha piperita), myrtus (Myrtus communis), orange peel (Citrus sinensis), sage (Salvia officinalis), thyme (Thymbra spicata), and Turkish oregano (Origanum minutiflorum)--were related to inhibition of 10 bacteria through multiple linear or non-linear (M(N)LR) models-four Gram-positive bacteria of Listeria innocua, coagulase-negative staphylococci, Staphylococcus aureus, and Bacillus subtilis, and six Gram-negative bacteria of Yersinia enterocolitica, Salmonella Enteritidis, Salmonella Typhimurium, Proteus mirabilis, Escherichia coli O157:H7, and Klebsiella oxytoca. A total of 65 compounds with different antioxidant capacity, phenolic substance content and antibacterial properties were detected with 14 plant essential oils. The best-fit M(N)LR models indicated that relative to anise essential oil, the essential oils of oreganos, cinnamon, and thyme had consistently high inhibitory effects, while orange peel essential oil had consistently a low inhibitory effect. Regression analysis indicated that beta-bisabolene (Turkish and Istanbul oreganos), and terpinolene (thyme) were found to be the most inhibitory compounds regardless of the bacteria type tested. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. EVALUATION OF ANTIBACTERIAL EFFECT OF PRODIGIOSIN PIGMENT PRODUCED BY SERRATIA MARCESCENS AGAINST STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI ISOLATED FROM PROCESSED FOOD

    OpenAIRE

    Parya karbaschi , Bahareh Rahimian Zarif * and Zahra Houshmandi

    2017-01-01

    prodigiosin pigment is three Pyrrole that is secondary metabolite produced by some bacterial species like Serratia marcescens . prodigiosin activities and frequent drug shown to inhibit bacterial And has attracted the attention of many researchers in the field of medicine and pharmacy should be.The aim of this study was Evaluation of antibacterial effect of prodigiosin pigment produced by Serratia marcescens against Staphylococcus aureus and Escherichia coli isolated from processed food. Meth...

  20. Evaluation of chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effects of Aloysia citrodora extract on colon cancer cell line using Real Time PCR and Flow-cytometry methods

    OpenAIRE

    Amir Mirzaie; Seyed Ataollah Sadat Shandiz; Hassan Noorbazargan; Elahe Ali Asgary

    2016-01-01

    Background and aims: Aloysia citrodora belongs to the Verbenaceae family of plants, a well-known herbal medicine in Iran. The aim of the present study was to investigate the chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effect of A. citrodora extract against human colon cancer using real time PCR and flow cytometry methods. Materials and Methods: this experimental study was carried out in Islamic Azad University, East Tehran Branch, from March to September of 2...

  1. Effect of Infusions of Non-Antibiotic Antibacterials Alone and in Combination with Cephradine on Milk Yield of Buffaloes Affected with Clinical Mastitis

    Directory of Open Access Journals (Sweden)

    M. Yousaf*, G. Muhammad1, M. Z. Khan2 and S. U. Rahman3

    2010-01-01

    Full Text Available The objective of the present study was to evaluate the effect of four non-antibiotic antibacterials alone or in combination with cephradine in buffaloes on milk yield of mastitis affected quarters. For this purpose, 270 clinically mastitic quarters were grouped in randomized pattern. Non-antibiotic antibacterials viz., 2.5% chlorpromazine (2 ml, 4% lidocaine (10 ml, 10% povidone-iodine (10 ml and 99.5% dimethylsulphoxide (20 ml alone and in combination with first generation cephalosporin (cephradine 500 mg were instilled into clinically mastitic quarters daily for five days. The group administered cephradine alone served as control. Mean milk yield (L/quarter per day was recorded before administration of treatment and over a period of 4 weeks post initiation of treatment. Among the 4 non-antibiotic antibacterials tested alone, chlorpromazine (CPZ showed significantly higher (P<0.05 recuperative effect on the milk yield of clinically mastitic quarters of dairy buffaloes. However, dimethylsulphoxide (DMSO when infused alone, further aggravated (P<0.05 the milk yield loss, indicating negative effect on milk yield improvement. Adjuncting cephradine with each of the non-antibiotic antibacterials, the lidocaine-cephradine group showed the highest effect (p<0.05 on net recovery of milk yield on day 28 post initiation of treatment. It was concluded that that CPZ can be used in clinical mastitis in buffaloes as a low cost alternative to expensive branded antibiotics. Further, the use of lidocaine with cepheradnie was superior to all other combination regimens in milk yield recovery.

  2. Analyzing the antibacterial effects of food ingredients: model experiments with allicin and garlic extracts on biofilm formation and viability of Staphylococcus epidermidis

    OpenAIRE

    Wu, Xueqing; Santos, Regiane R; Fink-Gremmels, Johanna

    2015-01-01

    To demonstrate different effects of garlic extracts and their main antibiotic substance allicin, as a template for investigations on the antibacterial activity of food ingredients. Staphylococcus epidermidis ATCC 12228 and the isogenic biofilm-forming strain ATCC 35984 were used to compare the activity of allicin against planktonic bacteria and bacterial biofilms. The minimal inhibitory concentration (MIC) and the minimum biofilm inhibitory concentration (MBIC) for pure allicin were identical...

  3. Strong Stability Preserving Explicit Runge--Kutta Methods of Maximal Effective Order

    KAUST Repository

    Hadjimichael, Yiannis

    2013-07-23

    We apply the concept of effective order to strong stability preserving (SSP) explicit Runge--Kutta methods. Relative to classical Runge--Kutta methods, methods with an effective order of accuracy are designed to satisfy a relaxed set of order conditions but yield higher order accuracy when composed with special starting and stopping methods. We show that this allows the construction of four-stage SSP methods with effective order four (such methods cannot have classical order four). However, we also prove that effective order five methods---like classical order five methods---require the use of nonpositive weights and so cannot be SSP. By numerical optimization, we construct explicit SSP Runge--Kutta methods up to effective order four and establish the optimality of many of them. Numerical experiments demonstrate the validity of these methods in practice.

  4. Using strong nonlinearity and high-frequency vibrations to control effective mechanical stiffness

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2008-01-01

    High-frequency excitation (HFE) can be used to change the effective stiffness of an elastic structure, and related quanti-ties such as resonance frequencies, wave speed, buckling loads, and equilibrium states. There are basically two ways to do this: By using parametrical HFE (with or without non...... the method of direct separation of motions with results of a modified multiple scales ap-proach, valid also for strong nonlinearity, the stiffening ef-fect is predicted for a generic 1-dof system, and results are tested against numerical simulation and ((it is planned)) laboratory experiments....

  5. Three-loop Standard Model effective potential at leading order in strong and top Yukawa couplings

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stephen P. [Santa Barbara, KITP

    2014-01-08

    I find the three-loop contribution to the effective potential for the Standard Model Higgs field, in the approximation that the strong and top Yukawa couplings are large compared to all other couplings, using dimensional regularization with modified minimal subtraction. Checks follow from gauge invariance and renormalization group invariance. I also briefly comment on the special problems posed by Goldstone boson contributions to the effective potential, and on the numerical impact of the result on the relations between the Higgs vacuum expectation value, mass, and self-interaction coupling.

  6. Attosecond counter-rotating-wave effect in xenon driven by strong fields

    Science.gov (United States)

    Anand, M.; Pabst, Stefan; Kwon, Ojoon; Kim, Dong Eon

    2017-05-01

    We investigate the subfemtosecond dynamics of a highly excited xenon atom coherently driven by a strong control field at which the Rabi frequency of the system is comparable to the frequency of a driving laser. The widely used rotating-wave approximation breaks down at such fields, resulting in features such as the counter-rotating-wave (CRW) effect. We present a time-resolved observation of the CRW effect in the highly excited 4 d-1n p xenon using attosecond transient absorption spectroscopy. Time-dependent many-body theory confirms the observation and explains the various features of the absorption spectrum seen in experiment.

  7. Evaluation of Reciprocal Pharmaceutical Effects and Antibacterial Activity of Silver Nanoparticles and Methanolic Extract of Crocus sativus L. (Saffron on Some Bacterial Strains

    Directory of Open Access Journals (Sweden)

    Anahita Samiee Zafarghandi

    2017-03-01

    Full Text Available Background: Silver nanoparticles (Ag-NPs are the most prominent nanoparticles which are recognized for their high antimicrobial efficacy. Objectives: The aim of this study was to evaluate the reciprocal pharmaceutical effects and antibacterial activity of Ag-NPs and methanolic extract of Crocus sativus L. (saffron on some bacterial strains. Materials and Methods: For evaluation of antibacterial activity of Ag-NPs and methanolic extract of C. sativus L. (saffron on some bacteria, agar well diffusion method was used. Minimal inhibition concentration (MIC and minimum bactericidal concentration (MBC were determined for saffron extract, Ag-NPs, and their combination on methicillin-resistant Staphylococcus aureus (MRSA and S. pyogenes and S. epidermidis. Results: The combination of medium concentrations of Ag-NPs (500 μg/mL and saffron extract (50 mg/mL was in the optimum mode to eliminate S. epidermidis and S. pyogenes. The results showed that saffron extract, Ag-NPs, and their combined form had antibacterial effects on these bacteria. Conclusion: It is suggested to evaluate the synergistic effects of active components of the extract and antimicrobial preservatives used in food, health, pharmaceutical, and cosmetic industries.

  8. Interaction effects in a microscopic quantum wire model with strong spin-orbit interaction

    Science.gov (United States)

    Winkler, G. W.; Ganahl, M.; Schuricht, D.; Evertz, H. G.; Andergassen, S.

    2017-06-01

    We investigate the effect of strong interactions on the spectral properties of quantum wires with strong Rashba spin-orbit (SO) interaction in a magnetic field, using a combination of matrix product state and bosonization techniques. Quantum wires with strong Rashba SO interaction and magnetic field exhibit a partial gap in one-half of the conducting modes. Such systems have attracted wide-spread experimental and theoretical attention due to their unusual physical properties, among which are spin-dependent transport, or a topological superconducting phase when under the proximity effect of an s-wave superconductor. As a microscopic model for the quantum wire we study an extended Hubbard model with SO interaction and Zeeman field. We obtain spin resolved spectral densities from the real-time evolution of excitations, and calculate the phase diagram. We find that interactions increase the pseudo gap at k = 0 and thus also enhance the Majorana-supporting phase and stabilize the helical spin order. Furthermore, we calculate the optical conductivity and compare it with the low energy spiral Luttinger liquid result, obtained from field theoretical calculations. With interactions, the optical conductivity is dominated by an excotic excitation of a bound soliton-antisoliton pair known as a breather state. We visualize the oscillating motion of the breather state, which could provide the route to their experimental detection in e.g. cold atom experiments.

  9. Charging-delay effect on longitudinal dust acoustic shock wave in strongly coupled dusty plasma

    International Nuclear Information System (INIS)

    Ghosh, Samiran; Gupta, M.R.

    2005-01-01

    Taking into account the charging-delay effect, the nonlinear propagation characteristics of longitudinal dust acoustic wave in strongly coupled collisional dusty plasma described by generalized hydrodynamic model have been investigated. In the 'hydrodynamic limit', a Korteweg-de Vries Burger (KdVB) equation with a damping term arising due to dust-neutral collision is derived in which the Burger term is proportional to the dissipation due to dust viscosity through dust-dust correlation and charging-delay-induced anomalous dissipation. On the other hand, in the 'kinetic limit', a KdVB equation with a damping term and a nonlocal nonlinear forcing term arising due to memory-dependent strong correlation effect of dust fluid is derived in which the Burger term depends only on the charging-delay-induced dissipation. Numerical solution of integrodifferential equations reveals that (i) dissipation due to dust viscosity and principally due to charging delay causes excitation of the longitudinal dust acoustic shock wave in strongly coupled dusty plasma and (ii) dust-neutral collision does not appear to play any direct role in shock formation. The condition for the generation of shock is also discussed briefly

  10. Challenges in inflationary magnetogenesis: Constraints from strong coupling, backreaction, and the Schwinger effect

    Science.gov (United States)

    Sharma, Ramkishor; Jagannathan, Sandhya; Seshadri, T. R.; Subramanian, Kandaswamy

    2017-10-01

    Models of inflationary magnetogenesis with a coupling to the electromagnetic action of the form f2Fμ νFμ ν , are known to suffer from several problems. These include the strong coupling problem, the backreaction problem and also strong constraints due to the Schwinger effect. We propose a model which resolves all these issues. In our model, the coupling function, f , grows during inflation and transits to a decaying phase post-inflation. This evolutionary behavior is chosen so as to avoid the problem of strong coupling. By assuming a suitable power-law form of the coupling function, we can also neglect backreaction effects during inflation. To avoid backreaction post-inflation, we find that the reheating temperature is restricted to be below ≈1.7 ×104 GeV . The magnetic energy spectrum is predicted to be nonhelical and generically blue. The estimated present day magnetic field strength and the corresponding coherence length taking reheating at the QCD epoch (150 MeV) are 1.4 ×10-12 G and 6.1 ×10-4 Mpc , respectively. This is obtained after taking account of nonlinear processing over and above the flux-freezing evolution after reheating. If we consider also the possibility of a nonhelical inverse transfer, as indicated in direct numerical simulations, the coherence length and the magnetic field strength are even larger. In all cases mentioned above, the magnetic fields generated in our models satisfy the γ -ray bound below a certain reheating temperature.

  11. Extended Parrondo's game and Brownian ratchets: Strong and weak Parrondo effect

    Science.gov (United States)

    Wu, Degang; Szeto, Kwok Yip

    2014-02-01

    Inspired by the flashing ratchet, Parrondo's game presents an apparently paradoxical situation. Parrondo's game consists of two individual games, game A and game B. Game A is a slightly losing coin-tossing game. Game B has two coins, with an integer parameter M. If the current cumulative capital (in discrete unit) is a multiple of M, an unfavorable coin pb is used, otherwise a favorable pg coin is used. Paradoxically, a combination of game A and game B could lead to a winning game, which is the Parrondo effect. We extend the original Parrondo's game to include the possibility of M being either M1 or M2. Also, we distinguish between strong Parrondo effect, i.e., two losing games combine to form a winning game, and weak Parrondo effect, i.e., two games combine to form a better-performing game. We find that when M2 is not a multiple of M1, the combination of B (M1) and B (M2) has strong and weak Parrondo effect for some subsets in the parameter space (pb,pg), while there is neither strong nor weak effect when M2 is a multiple of M1. Furthermore, when M2 is not a multiple of M1, a stochastic mixture of game A may cancel the strong and weak Parrondo effect. Following a discretization scheme in the literature of Parrondo's game, we establish a link between our extended Parrondo's game with the analysis of discrete Brownian ratchet. We find a relation between the Parrondo effect of our extended model to the macroscopic bias in a discrete ratchet. The slope of a ratchet potential can be mapped to the fair game condition in the extended model, so that under some conditions, the macroscopic bias in a discrete ratchet can provide a good predictor for the game performance of the extended model. On the other hand, our extended model suggests a design of a ratchet in which the potential is a mixture of two periodic potentials.

  12. Strong coupling effects between a meta-atom and MIM nanocavity

    Directory of Open Access Journals (Sweden)

    San Chen

    2012-09-01

    Full Text Available In this paper, we investigate the strong coupling effects between a meta-atom and a metal-insulator-metal (MIM nanocavity. By changing the meta-atom sizes, we achieve the meta-atomic electric dipole, quadrupole or multipole interaction with the plasmonic nanocavity, in which characteristic anticrossing behaviors demonstrate the occurrence of the strong coupling. The various interactions present obviously different splitting values and behaviors of dependence on the meta-atomic position. The largest Rabi-type splittings, about 360.0 meV and 306.1 meV, have been obtained for electric dipole and quadrupole interaction, respectively. We attribute the large splitting to the highly-confined cavity mode and the large transition dipole of the meta-atom. Also the Rabi-type oscillation in time domain is given.

  13. Realization of effective super Tonks-Girardeau gases via strongly attractive one-dimensional Fermi gases

    International Nuclear Information System (INIS)

    Chen Shu; Yin Xiangguo; Guan Liming; Guan Xiwen; Batchelor, M. T.

    2010-01-01

    A significant feature of the one-dimensional super Tonks-Girardeau gas is its metastable gas-like state with a stronger Fermi-like pressure than for free fermions which prevents a collapse of atoms. This naturally suggests a way to search for such strongly correlated behavior in systems of interacting fermions in one dimension. We thus show that the strongly attractive Fermi gas without polarization can be effectively described by a super Tonks-Girardeau gas composed of bosonic Fermi pairs with attractive pair-pair interaction. A natural description of such super Tonks-Girardeau gases is provided by Haldane generalized exclusion statistics. In particular, they are equivalent to ideal particles obeying more exclusive statistics than Fermi-Dirac statistics.

  14. Effects of Strong Correlations on the Disorder-Induced Zero Bias Anomaly

    Science.gov (United States)

    Atkinson, William; Song, Yun; Bulut, Sinan; Wortis, Rachel

    2009-03-01

    In conventional metals and semiconductors, density of states anomalies result from the interplay between disorder and interactions. Motivated by a number of experiments that find zero bias anomalies (ZBA) in transition metal oxides, we have performed calculations to determine the effect of strong correlations on the ZBA in disordered interacting systems. We use a self-consistent mean-field theory that incorporates strong correlations and treats spatial fluctuations of the disorder potential exactly. We discuss both the Anderson-Hubbard model and the extended Anderson-Hubbard model. We find that, even for a zero-range interaction, nonlocal self-energy corrections lead to the formation of an Altshuler-Aronov-like ZBA. In the extended Anderson-Hubbard model, Efros-Shklovskii-like physics dominates at large disorder.

  15. Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study

    Science.gov (United States)

    Soleimanpour, Saman; Sedighinia, Fereshteh Sadat; Safipour Afshar, Akbar; Zarif, Reza; Ghazvini, Kiarash

    2015-01-01

    Objective: In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Materials and methods: Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Results: Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05). No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. Conclusion: This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts. PMID:26101754

  16. Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study

    Directory of Open Access Journals (Sweden)

    Saman Soleimanpour

    2015-04-01

    Full Text Available Objective: In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Materials and methods: Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Results: Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05. No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. Conclusion: This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts.

  17. Synthesis, structural characterization of nano ZnTiO3 ceramic: An effective azo dye adsorbent and antibacterial agent

    Directory of Open Access Journals (Sweden)

    R.S. Raveendra

    2014-12-01

    Full Text Available Nanocrystalline meta-zinc titanate (ZnTiO3 ceramic was prepared using a self-propagating solution combustion synthesis (SCS for the first time using urea as fuel. The product was calcined at 800 °C for 2 h to improve the crystallinity. Powder X-ray diffraction (PXRD, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, energy-dispersive X-ray spectroscopy (EDAX, high resolution transmission electron microscopy (HR-TEM and UV–vis absorption spectroscopy were used to characterize the final product. PXRD results show that the ilmenite type rhombohedral structure was formed when the sample was calcined at 800 °C for 2 h. Adsorption experiments were performed with cationic malachite green (MG dye. ∼96% dye was adsorbed onto nanocrystalline ZnTiO3 ceramic at pH 9 for 30 min of the contact time. The optimum adsorbent dose was found to be 0.45 g/L of dye. Langmuir–Hinshelwood model was used to study adsorption kinetics and first order kinetic model best describes the MG adsorption on ZnTiO3. Antibacterial activity was investigated against gram negative Klebsiella aerogenes, Pseudomonas desmolyticum, Escherichia coli, and gram positive Staphylococcus aureus bacteria by agar well diffusion method. Nanocrystalline ZnTiO3 ceramic showed significant effect on all the four bacterial strains at the concentration of 1000 and 1500 μg per well.

  18. Synergistic antibacterial effect of Bi2S3nanospheres combined with ineffective antibiotic gentamicin against methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Ma, Lulu; Wu, Jie; Wang, Shilei; Yang, Hao; Liang, Donghui; Lu, Zhong

    2017-03-01

    In this paper, Bi 2 S 3 nanospheres with size of 212nm were prepared by a simple hydrothermal process. The selectively enhanced antibacterial effects of Bi 2 S 3 nanospheres with three classes of ineffective antibiotics, β-lactam (cefuroxime, CXM; cefotaxime, CTX and piperacillin, PIP), quinolone (ciprofloxacin, CIP) and aminoglycoside (gentamicin, GEN) against clinical isolated methicillin-resistant Staphylococcus aureus (MRSA) were investigated for the first time. GEN shows significantly synergistic growth inhibition against MRSA when combined with Bi 2 S 3 nanospheres, while CXM, CTX, PIP and CIP do not. Raman spectroscopy and Z potential studies reveal that Bi 2 S 3 could interact with GEN and the combination showed small electronegativity, which probably induced the increase of GEN content in cytoplasm of bacteria. Furthermore, the combination of Bi 2 S 3 nanospheres and GEN can destroy the bacterial membrane function and induce more bactericidal reactive oxygen generation than that of Bi 2 S 3 or GEN alone. The cytotoxicity test indicates that the combination of Bi 2 S 3 and GEN presented low toxicity to human normal hepatocyte L02. This work shows that Bi 2 S 3 nanospheres can be used to enhance the action of ineffective antibiotic GEN against MRSA, thus strengthening the antibiotic capacity for fighting MRSA infections. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Eucalyptus oil nanoemulsion-impregnated chitosan film: antibacterial effects against a clinical pathogen, Staphylococcus aureus, in vitro

    Directory of Open Access Journals (Sweden)

    Sugumar S

    2015-10-01

    Full Text Available Saranya Sugumar, Amitava Mukherjee, Natarajan Chandrasekaran Centre for Nanobiotechnology, VIT University, Vellore, India Abstract: Eucalyptus oil (Eucalyptus globulus nanoemulsion was formulated using low- and high-energy emulsification methods. Development of nanoemulsion was optimized for system parameters such as emulsifier type, emulsifier concentration, and emulsification methods to obtain a lower droplet size with greater stability. The minimized droplet diameter was achieved using the high-energy method of ultrasonication. Tween 80 was more effective in reducing droplet size and emulsion appearance when compared to Tween 20. Stable nanoemulsion was formulated with Tween 80 as a surfactant, and the particle size was found to be 9.4 nm (1:2 v/v. The eucalyptus oil nanoemulsion was impregnated into chitosan (1% as a biopolymer in varying concentrations. Further, the film was characterized by moisture content, microscopic study, X-ray diffraction, and Fourier transform infrared spectroscopy. Also, the film with and without nanoemulsion was evaluated against Staphylococcus aureus. The nanoemulsion-impregnated chitosan film showed higher antibacterial activity than chitosan film. These results support the inclusion of nanoemulsion-impregnated chitosan film in wound management studies. Keywords: essential oil, emulsion, biopolymer, impregnation, thin film, wound isolate

  20. Antibacterial and antigelatinolytic effects of Satureja hortensis L. essential oil on epithelial cells exposed to Fusobacterium nucleatum.

    Science.gov (United States)

    Zeidán-Chuliá, Fares; Keskin, Mutlu; Könönen, Eija; Uitto, Veli-Jukka; Söderling, Eva; Moreira, José Cláudio Fonseca; Gürsoy, Ulvi K

    2015-04-01

    The present report examined the effects of essential oils (EOs) from Satureja hortensis L. and Salvia fruticosa M. on the viability and outer membrane permeability of the periodontopathogen Fusobacterium nucleatum, a key bacteria in oral biofilms, as well as the inhibition of matrix metalloproteinase (MMP-2 and MMP-9) activities in epithelial cells exposed to such bacteria. Membrane permeability was tested by measuring the N-phenyl-1-naphthylamine uptake and bacterial viability by using the commercially available Live/Dead BacLight kit. In addition, gelatin zymography was performed to analyze the inhibition of F. nucleatum-induced MMP-2 and MMP-9 activities in HaCaT cells. We showed that 5, 10, and 25 μL/mL of Sat. hortensis L. EO decreased the ratio of live/dead bacteria and increased the outer membrane permeability in a range of time from 0 to 5 min. Treatments with 10 and 25 μL/mL of Sal. fruticosa M. also increased the membrane permeability and 5, 10, and 25 μL/mL of both EOs inhibited MMP-2 and MMP-9 activities in keratinocytes induced after exposure of 24 h to F. nucleatum. We conclude that antibacterial and antigelatinolytic activities of Sat. hortensis L. EO have potential for the treatment of periodontal inflammation.

  1. Antibacterial Activity, Antioxidant Effect and Chemical Composition of Propolis from the Región del Maule, Central Chile.

    Science.gov (United States)

    Nina, Nélida; Quispe, Cristina; Jiménez-Aspee, Felipe; Theoduloz, Cristina; Feresín, Gabriela Egly; Lima, Beatriz; Leiva, Elba; Schmeda-Hirschmann, Guillermo

    2015-10-06

    Propolis is commercialized in Chile as an antimicrobial agent. It is obtained mainly from central and southern Chile, but is used for the same purposes regardless of its origin. To compare the antimicrobial effect, the total phenolic (TP), the total flavonoid (TF) content and the phenolic composition, 19 samples were collected in the main production centers in the Región del Maule, Chile. Samples were extracted with MeOH and assessed for antimicrobial activity against Gram (+) and Gram (-) bacteria. TP and TF content, antioxidant activity by the DPPH, FRAP and TEAC methods were also determined. Sample composition was assessed by HPLD-DAD-ESI-MS/MS. Differential compounds in the samples were isolated and characterized. The antimicrobial effect of the samples showed MICs ranging from 31.5 to > 1000 µg/mL. Propolis from the central valley was more effective as antibacterial than those from the coastal area or Andean slopes. The samples considered of interest (MIC ≤ 62.5 µg/mL) showed effect on Escherichia coli, Pseudomonas sp., Yersinia enterocolitica and Salmonella enteritidis. Two new diarylheptanoids, a diterpene, the flavonoids pinocembrin and chrysin were isolated and elucidated by spectroscopic and spectrometric means. Some 29 compounds were dereplicated by HPLC-MS and tentatively identified, including nine flavones/flavonol derivatives, one flavanone, eight dihydroflavonols and nine phenyl-propanoids. Propolis from the Región del Maule showed large variation in antimicrobial effect, antioxidant activity and composition. So far the presence of diarylheptanoids in samples from the coastal area of central Chile can be considered as a marker of a new type of propolis.

  2. Antibacterial Activity, Antioxidant Effect and Chemical Composition of Propolis from the Región del Maule, Central Chile

    Directory of Open Access Journals (Sweden)

    Nélida Nina

    2015-10-01

    Full Text Available Propolis is commercialized in Chile as an antimicrobial agent. It is obtained mainly from central and southern Chile, but is used for the same purposes regardless of its origin. To compare the antimicrobial effect, the total phenolic (TP, the total flavonoid (TF content and the phenolic composition, 19 samples were collected in the main production centers in the Región del Maule, Chile. Samples were extracted with MeOH and assessed for antimicrobial activity against Gram (+ and Gram (− bacteria. TP and TF content, antioxidant activity by the DPPH, FRAP and TEAC methods were also determined. Sample composition was assessed by HPLD-DAD-ESI-MS/MS. Differential compounds in the samples were isolated and characterized. The antimicrobial effect of the samples showed MICs ranging from 31.5 to > 1000 µg/mL. Propolis from the central valley was more effective as antibacterial than those from the coastal area or Andean slopes. The samples considered of interest (MIC ≤ 62.5 µg/mL showed effect on Escherichia coli, Pseudomonas sp., Yersinia enterocolitica and Salmonella enteritidis. Two new diarylheptanoids, a diterpene, the flavonoids pinocembrin and chrysin were isolated and elucidated by spectroscopic and spectrometric means. Some 29 compounds were dereplicated by HPLC-MS and tentatively identified, including nine flavones/flavonol derivatives, one flavanone, eight dihydroflavonols and nine phenyl-propanoids. Propolis from the Región del Maule showed large variation in antimicrobial effect, antioxidant activity and composition. So far the presence of diarylheptanoids in samples from the coastal area of central Chile can be considered as a marker of a new type of propolis.

  3. New potent antibacterials against Gram-positive multiresistant pathogens: effects of side chain modification and chirality in linezolid-like 1,2,4-oxadiazoles.

    Science.gov (United States)

    Fortuna, Cosimo G; Berardozzi, Roberto; Bonaccorso, Carmela; Caltabiano, Gianluigi; Di Bari, Lorenzo; Goracci, Laura; Guarcello, Annalisa; Pace, Andrea; Palumbo Piccionello, Antonio; Pescitelli, Gennaro; Pierro, Paola; Lonati, Elena; Bulbarelli, Alessandra; Cocuzza, Clementina E A; Musumarra, Giuseppe; Musumeci, Rosario

    2014-12-15

    The effects of side chain modification and chirality in linezolid-like 1,2,4-oxadiazoles have been studied to design new potent antibacterials against Gram-positive multidrug-resistant pathogens. The adopted strategy involved a molecular modelling approach, the synthesis and biological evaluation of new designed compounds, enantiomers separation and absolute configuration assignment. Experimental determination of the antibacterial activity of the designed (S)-1-((3-(4-(3-methyl-1,2,4-oxadiazol-5-yl)phenyl)-oxazolidin-2-one-5-yl)methyl)-3-methylthiourea and (S)-1-((3-(3-fluoro-4-(3-methyl-1,2,4-oxadiazol-5-yl)phenyl)-oxazolidin-2-one-5-yl)methyl)-3-methylthiourea against multidrug resistant linezolid bacterial strains was higher than that of linezolid. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Chemical Analysis and Study of Phenolics, Antioxidant Activity, and Antibacterial Effect of the Wood and Bark of Maclura tinctoria (L. D. Don ex Steud.

    Directory of Open Access Journals (Sweden)

    K. C. Lamounier

    2012-01-01

    Full Text Available Maclura tinctoria (L. D. Don ex Steud. has one of the highest qualities among the coefficients for Brazilian woods (up to 9.6 and resistance rates equivalent to Indian teak (Tectona grandis. In this study, the macromolecular constituents and total phenols compounds as well as the antioxidant and antibacterial activities of this wood were evaluated. Total phenols and proanthocyanidin levels were higher in wood when compared with bark levels. The antioxidant activity of wood extracts (IC50 = 18.7 μg/mL was more effective than that of bark extracts (IC50 = 20.9 μg/mL. Wood and bark extracts revealed a high potential for inhibition of aerobic and anaerobic bacteria. The bark extracts were the most active (MIC from 20 to 60 μg/mL. Both antioxidant activity and high potential for bacteria inhibition turn these extracts promising for drug formulations, especially as antibacterial agent.

  5. Effective action for superfluid Fermi systems in the strong-coupling limit

    International Nuclear Information System (INIS)

    Dupuis, N.

    2005-01-01

    We derive the low-energy effective action for three-dimensional superfluid Fermi systems in the strong-coupling limit, where superfluidity originates from Bose-Einstein condensation of composite bosons. Taking into account density and pairing fluctuations on the same footing, we show that the effective action involves only the fermion density ρ r and its conjugate variable, the phase θ r of the pairing order parameter Δ r . We recover the standard action of a Bose superfluid of density ρ r /2, where the bosons have a mass m B =2m and interact via a repulsive contact potential with amplitude g B =4πa B /m B ,a B =2a (a the s-wave scattering length associated to the fermion-fermion interaction in vacuum). For lattice models, the derivation of the effective action is based on the mapping of the attractive Hubbard model onto the Heisenberg model in a uniform magnetic field, and a coherent state path integral representation of the partition function. The effective description of the Fermi superfluid in the strong-coupling limit is a Bose-Hubbard model with an intersite hopping amplitude t B =J/2 and an on-site repulsive interaction U B =2Jz, where J=4t 2 /U (t and -U are the intersite hopping amplitude and the on-site attraction in the (fermionic) Hubbard model, z the number of nearest-neighbor sites)

  6. Effective action for superfluid Fermi systems in the strong-coupling limit

    Science.gov (United States)

    Dupuis, N.

    2005-07-01

    We derive the low-energy effective action for three-dimensional superfluid Fermi systems in the strong-coupling limit, where superfluidity originates from Bose-Einstein condensation of composite bosons. Taking into account density and pairing fluctuations on the same footing, we show that the effective action involves only the fermion density ρr and its conjugate variable, the phase θr of the pairing order parameter Δr . We recover the standard action of a Bose superfluid of density ρr/2 , where the bosons have a mass mB=2m and interact via a repulsive contact potential with amplitude gB=4πaB/mB,aB=2a ( a the s -wave scattering length associated to the fermion-fermion interaction in vacuum). For lattice models, the derivation of the effective action is based on the mapping of the attractive Hubbard model onto the Heisenberg model in a uniform magnetic field, and a coherent state path integral representation of the partition function. The effective description of the Fermi superfluid in the strong-coupling limit is a Bose-Hubbard model with an intersite hopping amplitude tB=J/2 and an on-site repulsive interaction UB=2Jz , where J=4t2/U ( t and -U are the intersite hopping amplitude and the on-site attraction in the (fermionic) Hubbard model, z the number of nearest-neighbor sites).

  7. Screening of the antibacterial effects of a variety of essential oils on respiratory tract pathogens, using a modified dilution assay method.

    Science.gov (United States)

    Inouye, S; Yamaguchi, H; Takizawa, T

    2001-12-01

    The purpose of this study was to examine the antibacterial effects of a wide variety of essential oils on major respiratory tract pathogens. The antibacterial activity of 14 essential oils and their major components was evaluated by agar-plate dilution assay under sealed conditions, with agar used as a stabilizer for homogeneous dispersion. Of the selected strains of four major bacteria causing respiratory tract infection, Haemophilus influenzae was most susceptible to the essential oils, followed by Streptococcus pneumoniae and Streptococcus pyogenes. Staphylococcus aureus was less susceptible. No cross-resistance was observed between penicillin-sensitive and penicillin-resistant S. pneumoniae. Escherichia coli, used as a control bacterium, showed the lowest susceptibility. Essential oils containing aldehyde or phenol as a major component showed the highest antibacterial activity, followed by the essential oils containing terpene alcohols. Other essential oils, containing terpene ketone, or ether, had much weaker activity, and an oil containing terpene hydrocarbon was inactive. Based on these findings, thyme (wild, red, and geraniol types), cinnamon bark, lemongrass, perilla, and peppermint oils were selected for further evaluation of their effects on respiratory tract infection.

  8. Studies of antibacterial effects of synthesized silver nanoparticles using a novel thermotolerant Isoptericola variabilis sp. IRSH1 against Staphylococcus aureus and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    F. Hajmohammadi

    2017-08-01

    Full Text Available Background: Silver nanoparticles can consider as an alternative source for some antibiotic usages due to those effective antibacterial activity and eco-friendly characteristics. Objective: This in vitro study was done to evaluate the inhibitory effect of extracellular synthesized of silver nanoparticles using inexpensive cellulosic materials and supernatant culture of Isoptericola variabilis sp. IRSH1 against Staphylococcus aureus and Pseudomonas aeruginosa. Methods: Silver nanoparticles were produced by extracellular biosynthesis using supernatant culture of a novel thermotolerant Isoptericola variabilis sp.IRSH1 and characterized. The antibacterial activities of the synthesized silver nanoparticles were examined by the standard KirbyBauer disc diffusion method against Staphylococcus aureus and Pseudomonas aeruginosa on Muller-Hinton agar plates. Findings: The silver nanoparticles were produced with an average size of 77 nm and 0.29 polydispersity index (PDI. The inhibition zones of AgNPs (1000 µg/ml were 10 mm and 11 mm against Staphylococcus aureus and Pseudomonas aeruginosa respectively. Conclusion: The biosynthesized AgNPs has good antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa. The results indicate Pseudomonas aeruginosa is more sensitive to silver nanoparticles.

  9. A novel preparation of silver-plated polyacrylonitrile fibers functionalized with antibacterial and electromagnetic shielding properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Li, Weiya; Gao, Cuicui; Tian, Weicheng [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Sun, Bin [College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Yu, Dan, E-mail: yudan@dhu.edu.cn [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China)

    2015-07-01

    Highlights: • We propose a novel modification method to initiate silver electroless plating on PAN fiber without noble metal catalyst. • The silver-plated fiber we fabricated has good electromagnetic shielding effectiveness and antibacterial properties. • The metal layer has good adhesion strength and the properties of the silver-plated fiber can stand 30 cycles of standard washing. - Abstract: Polyacrylonitrile (PAN) fibers with antibacterial, electromagnetic shielding and antistatic functionalities were fabricated in this paper through modifying PAN fibers with (3-aminopropyl)triethoxysilane (APTES) and 3-mercaptopropyltriethoxysilane (MPTES) sequentially and followed with silver electroless plating. The silver layer on PAN fiber surface was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). The results show that the silver layer was plated uniformly and compactly. The surface resistance of plated fabric was about 40 mΩ/sq on average. The antibacterial tests demonstrate that silver-plated PAN fiber exhibits excellent antibacterial property against S. aureus and E. coli with a non-leaching characteristic. The antibacterial property remains good after 30 cycles of standard washing, which is a strong proof of a durable adhesion between metal layer and fiber. The shielding effectiveness (SE) of silver-plated PAN fabric before and after 30 cycles of standard washing was about 40–80 dB and 35–50 dB, respectively. This resultant fiber can be used in many occasions for reducing or preventing electromagnetic interference (EMI) and electromagnetic hazards.

  10. A novel preparation of silver-plated polyacrylonitrile fibers functionalized with antibacterial and electromagnetic shielding properties

    International Nuclear Information System (INIS)

    Wang, Wei; Li, Weiya; Gao, Cuicui; Tian, Weicheng; Sun, Bin; Yu, Dan

    2015-01-01

    Highlights: • We propose a novel modification method to initiate silver electroless plating on PAN fiber without noble metal catalyst. • The silver-plated fiber we fabricated has good electromagnetic shielding effectiveness and antibacterial properties. • The metal layer has good adhesion strength and the properties of the silver-plated fiber can stand 30 cycles of standard washing. - Abstract: Polyacrylonitrile (PAN) fibers with antibacterial, electromagnetic shielding and antistatic functionalities were fabricated in this paper through modifying PAN fibers with (3-aminopropyl)triethoxysilane (APTES) and 3-mercaptopropyltriethoxysilane (MPTES) sequentially and followed with silver electroless plating. The silver layer on PAN fiber surface was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). The results show that the silver layer was plated uniformly and compactly. The surface resistance of plated fabric was about 40 mΩ/sq on average. The antibacterial tests demonstrate that silver-plated PAN fiber exhibits excellent antibacterial property against S. aureus and E. coli with a non-leaching characteristic. The antibacterial property remains good after 30 cycles of standard washing, which is a strong proof of a durable adhesion between metal layer and fiber. The shielding effectiveness (SE) of silver-plated PAN fabric before and after 30 cycles of standard washing was about 40–80 dB and 35–50 dB, respectively. This resultant fiber can be used in many occasions for reducing or preventing electromagnetic interference (EMI) and electromagnetic hazards

  11. Effects of strong radiation reaction and quantum-electrodynamics on relativistic transparency

    Science.gov (United States)

    Zhang, Peng; Thomas, A. G. R.; Ridgers, C. P.

    2013-10-01

    Relativistic transparency is the process that optically switches the overdense plasma from opaque to transparent and enables light propagation through the otherwise opaque plasma, when light of sufficient intensity drives the electrons in the plasma to near light speeds. We study the relativistic transparency in radiation dominant and strong quantum electrodynamic (QED) regime, for the interaction of high-intensity laser pulses with a thin foil solid target. We analytically study the simplified motion of an electron in a circularly polarized plane wave to understand the physics of the transmissivity and absorption in the presence of classical and quantum-corrected, semiclassical radiation-reaction forces and the trapping of particles in nodes of laser standing wave through radiative cooling. These arguments are supported by both one dimensional and two dimensional particle-in-cell calculations including strong field QED effects. Measurement of the transmission of these pulses would be experimentally feasible and a robust test of the strong field QED particle-in-cell framework.

  12. An In-Vitro Investigation of the Antibacterial Effects of the Methanol and Aqueous Extracts and the Supernatant of the Algae Chlorella vulgaris CCATM 210-1 on Multiantibiotic-Resistant Staphylococcus aureus Isolates Causing Urinary Tract Infections

    OpenAIRE

    Senobar Asadi; Monir Doudi; Behrouz Zarei Darki

    2016-01-01

    Algae contain compounds, some of which have antibacterial properties. For example, the antibiotic Chlorellin can be mentioned, which is extracted from Chlorella species. The methanol and aqueous extracts, and the supernatant of the algae Chlorella vulgaris CCATM- 210-1 were used in this study. After culturing the Algae and preparing the supernatant and extracts, the antibacterial effects of the extracts and supernatant of this algae against multidrugresistant (MDR) Staphylococcus ...

  13. Drag Effect of Kompsat-1 During Strong Solar and Geomagnetic Activity

    Directory of Open Access Journals (Sweden)

    J. Park

    2007-06-01

    Full Text Available In this paper, we analyze the orbital variation of the KOrea Multi-Purpose SATellite-1(KOMPSAT-1 in a strong space environment due to satellite drag by solar and geomagnetic activities. The satellite drag usually occurs slowly, but becomes serious satellite drag when the space environment suddenly changes via strong solar activity like a big flare eruption or coronal mass ejections(CMEs. Especially, KOMPSAT-1 as a low earth orbit satellite has a distinct increase of the drag acceleration by the variations of atmospheric friction. We consider factors of solar activity to have serious effects on the satellite drag from two points of view. One is an effect of high energy radiation when the flare occurs in the Sun. This radiation heats and expands the upper atmosphere of the Earth as the number of neutral particles is suddenly increased. The other is an effect of Joule and precipitating particle heating caused by current of plasma and precipitation of particles during geomagnetic storms by CMEs. It also affects the density of neutral particles by heating the upper atmosphere. We investigate the satellite drag acceleration associated with the two factors for five events selected based on solar and geomagnetic data from 2001 to 2002. The major results can be summarized as follows. First, the drag acceleration started to increase with solar EUV radiation with the best cross-correlation (r = 0.92 for 1 day delayed F10.7. Second, the drag acceleration and Dst index have similar patterns when the geomagnetic storm is dominant and the drag acceleration abruptly increases during the strong geomagnetic storm. Third, the background variation of the drag accelerations is governed by the solar radiation, while their short term (less than a day variations is governed by geomagnetic storms.

  14. Effect of surface passivation on corrosion resistance and antibacterial properties of Cu-bearing 316L stainless steel

    Science.gov (United States)

    Zhao, Jinlong; Xu, Dake; Shahzad, M. Babar; Kang, Qiang; Sun, Ying; Sun, Ziqing; Zhang, Shuyuan; Ren, Ling; Yang, Chunguang; Yang, Ke

    2016-11-01

    The resistance for pitting corrosion, passive film stability and antibacterial performance of 316L-Cu SS passivated by nitric acid solution containing certain concentration of copper sulfate, were studied by electrochemical cyclic polarization, electrochemical impedance spectroscopy (EIS) and co-culture with bacteria. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the Cu2+ ions release from 316L-Cu SS surface. XPS analysis proved that the enrichment of CuO, Cr2O3 and Cr(OH)3 on the surface of specimen could simultaneously guarantee a better corrosion resistance and stable antibacterial properties. The biocompatibility evaluation determined by RTCA assay also indicated that the 316L-Cu SS after antibacterial passivation was completely biocompatible.

  15. Effect of vanadic anhydride and copper oxide on the development of hard porcelain composite and its antibacterial activity

    Directory of Open Access Journals (Sweden)

    Arpan Kool

    2014-09-01

    Full Text Available A mullite-reinforced porcelain composite with antibacterial properties has been developed using transition metal oxides by solid state sintering. The composite has been characterized in terms of mullite content, hardness, color and antibacterial properties. The physico-chemical properties of the porcelain were substantially increased in the presence of V2O5 and CuO. Well-crystallized needle shaped mullite of average length ∼ 3 μm was observed in the porcelain body at 1300 °C and 1500 °C after the addition of V2O5 and CuO. Vickers hardness of the composite increased 4.2 times for 2% V2O5 at 1500 °C. The porcelain composites showed satisfactory antibacterial activity on gram negative bacteria Escherichia coli with mortality rates of 45% and 22% for V2O5 and CuO doped porcelain respectively.

  16. Poly-ϵ-caprolactone/chitosan nanoparticles provide strong adjuvant effect for hepatitis B antigen.

    Science.gov (United States)

    Jesus, Sandra; Soares, Edna; Borchard, Gerrit; Borges, Olga

    2017-10-01

    This work aims to investigate the adjuvant effect of poly-ϵ-caprolactone/chitosan nanoparticles (NPs) for hepatitis B surface antigen (HBsAg) and the plasmid DNA encoding HBsAg (pRC/CMV-HBs). Both antigens were adsorbed onto preformed NPs. Vaccination studies were performed in C57BL/6 mice. Transfection efficiency was investigated in A549 cell line. HBsAg-adsorbed NPs generated strong anti-HBsAg IgG titers, mainly of IgG1 isotype, and induced antigen-specific IFN-γ and IL-17 secretion by spleen cells. The addition of pRC/CMV-HBs to the HBsAg-adsorbed NPs inhibited IL-17 secretion but had minor effect on IFN-γ levels. Lastly, pRC/CMV-HBs-loaded NPs generated a weak serum antibody response. Poly-ϵ-caprolactone/chitosan NPs provide a strong humoral adjuvant effect for HBsAg and induce a Th1/Th17-mediated cellular immune responses worth explore for hepatitis B virus vaccination.

  17. Dispersion of Co/CNTs via strong electrostatic adsorption method: Thermal treatment effect

    Energy Technology Data Exchange (ETDEWEB)

    Akbarzadeh, Omid, E-mail: omid.akbarzadeh63@gmail.com; Abdullah, Bawadi, E-mail: bawadi-abdullah@petronas.com.my; Subbarao, Duvvuri, E-mail: duvvuri-subbarao@petronas.com.my [Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Zabidi, Noor Asmawati Mohd, E-mail: noorasmawati-mzabidi@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2015-07-22

    The effect of different thermal treatment temperature on the structure of multi-walled carbon nanotubes (MWCNTs) and Co particle dispersion on CNTs support is studied using Strong electrostatic adsorption (SEA) method. The samples tested by N{sub 2}-adsorption, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). N{sub 2}-adsorption results showed BET surface area increased using thermal treatment and TEM images showed that increasing the thermal treatment temperature lead to flaky CNTs and defects introduced on the outer surface and Co particle dispersion increased.

  18. Gain length fitting formula for free-electron lasers with strong space-charge effects

    Directory of Open Access Journals (Sweden)

    G. Marcus

    2011-08-01

    Full Text Available We present a power-fit formula, obtained from a variational analysis using three-dimensional free-electron laser theory, for the gain length of a high-gain free-electron laser’s fundamental mode in the presence of diffraction, uncorrelated energy spread, and longitudinal space-charge effects. The approach is inspired by the work of Xie [Nucl. Instrum. Methods Phys. Res., Sect. A 445, 59 (2000NIMAER0168-900210.1016/S0168-9002(0000114-5], and provides a useful shortcut for calculating the gain length of the fundamental Gaussian mode of a free-electron laser having strong space-charge effects in the 3D regime. The results derived from analytic theory are in good agreement with detailed numerical particle simulations that also include higher-order space-charge effects, supporting the assumptions made in the theoretical treatment and the variational solutions obtained in the single-mode limit.

  19. Preparation and characterization of functional fabrics from bamboo charcoal/silver and titanium dioxide/silver composite powders and evaluation of their antibacterial efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fu-Chu, E-mail: yfc580629@yahoo.com.tw [Army Command Headquarters, MND, Taoyuan, Taiwan (China); Wu, Kuo-Hui [Department of Applied Chemistry and Materials Science, Chung Cheng Institute of Technology, NDU, No. 190, Sanyuan 1st Street, Tahsi, Taoyuan 335, Taiwan (China); Huang, Jen-Wei [Department of Physics, Chinese Military Academy, Fengshan, Kaohsiung, Taiwan (China); Horng, Deng-Nan; Liang, Chia-Feng [Department of Chemistry, Chinese Military Academy, Fengshan, Kaohsiung, Taiwan (China); Hu, Ming-Kuan [School of Pharmacy, National Defense Medical Center, Taipei, Taiwan (China)

    2012-07-01

    Bamboo charcoal supporting silver (BC/Ag) and titanium dioxide supporting silver (TiO{sub 2}/Ag) were prepared by activation and chemical reduction. The BC/Ag and TiO{sub 2}/Ag composites were characterized by silver particle size and distribution and antibacterial properties. The pore and surface properties were studied in terms of BET volumetric measurement with nitrogen adsorption, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The antibacterial effects of the BC/Ag and TiO{sub 2}/Ag composite powders were assessed from the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs), and an excellent antibacterial performance was discovered. Moreover, these composite powders were deposited via immersion coating onto fabrics (nonwoven and carbon fibers) to improve the antibacterial efficacy and to act as a biologically-protective material. The antibacterial activities of the fabrics supported by BC/Ag and TiO{sub 2}/Ag were studied in zone of inhibition and plate counting tests against Gram-positive Staphylococcus aureus ME/GM/TC Resistant, Bacillus subtilis, Candida albicans, Gram-negative Pseudomonas aeruginosae (CTZ and EM and GM) Res. Clin. Isol., Escherichia coli Juhl, and Klebsiella pneumoniae. The results showed that fabric-BC/Ag and fabric-TiO{sub 2}/Ag possess a strong antibacterial activity and an inhibitory effect on the growth of these bacteria and are therefore believed to have great potential for use as antibacterial fabrics.

  20. Antibacterial effects of gum kondagogu reduced/stabilized silver nanoparticles in combination with various antibiotics: a mechanistic approach

    Science.gov (United States)

    Rastogi, Lori; Kora, Aruna Jyothi; Sashidhar, R. B.

    2015-06-01

    Gum kondagogu reduced/stabilized silver nanoparticles (GK-AgNPs) were evaluated for their increased antibacterial and antibiofilm activities in combination with various antibiotics (ciprofloxacin, streptomycin and gentamicin) against Gram-positive ( Staphylococcus aureus 25923, Staphylococcus aureus 49834) and Gram-negative ( Escherichia coli 25922, Pseudomonas aeruginosa 27853) bacteria. The micro-broth dilution assay suggested an enhanced antibacterial activity of GK-AgNPs in combination with ciprofloxacin and aminoglycosides (streptomycin and gentamicin) against tested strains. Though the antibacterial activity of GK-AgNPs was found to increase significantly in the presence of antibiotics, the % enhancement was found to depend on both types of antibiotic and bacterial strain. It was also found that GK-AgNPs (1 µg/mL) in combination with various antibiotics at sub-MIC concentrations could inhibit 70 % of the bacterial biofilm formation as compared to respective controls. The enhanced antibacterial activity was due to the increased production of intracellular reactive oxygen species in bacteria when treated with a combination of GK-AgNPs and streptomycin as compared to individual treatment. The increased oxidative stress led to increased membrane damage as assessed by live/dead assay and higher levels of potassium ion release from the cells treated with both silver nanoparticles and streptomycin. The results suggested that the combination of antibiotics with GK-AgNPs has an enhanced antibacterial action. Further, the GK-AgNPs were found to be biocompatible up to a concentration of 2.5 µg/mL as assessed with MTT assay on HeLa cell line. The results suggest that GK-AgNPs could potentially be used as in vivo antibacterial agent in combination with antibiotics to overcome the problem of antibiotic resistance.

  1. The synergistic effects of CO2 laser treatment with calcium silicate cement of antibacterial, osteogenesis and cementogenesis efficacy

    Science.gov (United States)

    Hsu, T.-T.; Kao, C.-T.; Chen, Y.-W.; Huang, T.-H.; Yang, J.-J.; Shie, M.-Y.

    2015-05-01

    Calcium silicate-based material (CS) has been successfully used in dental clinical applications. Some researches show that the antibacterial effects of CO2 laser irradiation are highly efficient when bacteria are embedded in biofilm, due to a photo-thermal mechanism. The purpose of this study was to confirm the effects of CO2 laser irradiation on CS, with regard to both material characterization and human periodontal ligament cell (hPDLs) viability. CS was irradiated with a dental CO2 laser using directly mounted fiber optics in wound healing mode with a spot area of 0.25 cm2, and then stored in an incubator at 100% relative humidity and 37 °C for 1 d to set. The hPDLs cultured on CS were analyzed, along with their proliferation and odontogenic differentiation behaviors. The results indicate that the CO2 laser irradiation increased the amount of Ca and Si ions released from the CS, and regulated cell behavior. CO2 laser-irradiated CS promoted cementogenic differentiation of hPDLs, with the increased formation of mineralized nodules on the substrate’s surface. It also up-regulated the protein expression of multiple markers of cementogenic and the expression of cementum attachment protein. The current study provides new and important data about the effects of CO2 laser irradiation on CS. Taking cell functions into account, the Si concentration released from CS with laser irradiated may be lower than a critical value, and this information could lead to the development of new regenerative therapies for dentin and periodontal tissue.

  2. The synergistic effects of CO2 laser treatment with calcium silicate cement of antibacterial, osteogenesis and cementogenesis efficacy

    International Nuclear Information System (INIS)

    Hsu, T-T; Yang, J-J; Kao, C-T; Huang, T-H; Chen, Y-W; Shie, M-Y

    2015-01-01

    Calcium silicate-based material (CS) has been successfully used in dental clinical applications. Some researches show that the antibacterial effects of CO 2 laser irradiation are highly efficient when bacteria are embedded in biofilm, due to a photo-thermal mechanism. The purpose of this study was to confirm the effects of CO 2 laser irradiation on CS, with regard to both material characterization and human periodontal ligament cell (hPDLs) viability. CS was irradiated with a dental CO 2 laser using directly mounted fiber optics in wound healing mode with a spot area of 0.25 cm 2 , and then stored in an incubator at 100% relative humidity and 37 °C for 1 d to set. The hPDLs cultured on CS were analyzed, along with their proliferation and odontogenic differentiation behaviors. The results indicate that the CO 2 laser irradiation increased the amount of Ca and Si ions released from the CS, and regulated cell behavior. CO 2 laser-irradiated CS promoted cementogenic differentiation of hPDLs, with the increased formation of mineralized nodules on the substrate’s surface. It also up-regulated the protein expression of multiple markers of cementogenic and the expression of cementum attachment protein. The current study provides new and important data about the effects of CO 2 laser irradiation on CS. Taking cell functions into account, the Si concentration released from CS with laser irradiated may be lower than a critical value, and this information could lead to the development of new regenerative therapies for dentin and periodontal tissue. (letter)

  3. Antibacterial and osteo-stimulatory effects of a borate-based glass series doped with strontium ions.

    Science.gov (United States)

    Li, Yiming; Stone, Wendy; Schemitsch, Emil H; Zalzal, Paul; Papini, Marcello; Waldman, Stephen D; Towler, Mark R

    2016-11-01

    This work considered the effect of both increasing additions of Strontium (Sr 2+ ) and incubation time on solubility and both antibacterial and osteo-stimulatory effects of a series of glasses based on the B 2 O 3 -P 2 O 5 -CaCO 3 -Na 2 CO 3 -TiO 2 -SrCO 3 series. The amorphous nature of all the glasses was confirmed by X-ray diffraction. Discs of each glass were immersed in de-ionized water for 1, 7 and 30 days, and the water extracts were used for ion release profiles, pH measurements and cytotoxicity testing. Atomic absorption spectroscopy was employed to detect the release of Na + , Ca 2+ and Sr 2+ ions from the glasses with respect to maturation, which indicated that the addition of Sr 2+ retarded solubility of the glass series. This effect was also confirmed by weight loss analysis through comparing the initial weight of glass discs before and after periods of incubation. The incorporation of Sr 2+ in the glasses did not influence the pH of the water extracts when the glasses were stored for up to 30 days. Cytotoxicity testing with an osteoblastic cell line (MC3T3-E1) indicated that glasses with the higher (20 mol% and 25 mol%) Sr 2+ incorporation promoted proliferation of osteoblast cells, while the glasses with lower Sr 2+ contents inhibited cell growth. The glass series, except for Ly-B5 (which contained the highest Sr 2+ incorporation; 25 mol%), were bacteriostatic against S. aureus in the short term (1-7 days) as a result of the dissolution products released. © The Author(s) 2016.

  4. THE BACTERIOLOGIC EVALUATION OF ANTIBACTERIAL EFFECT: NORMAL SALINE 5.25% AND 0.5%, SODIUM HYPOCHLORITE AND CALCIUM HYDROXIDE

    Directory of Open Access Journals (Sweden)

    A.R FARHAD

    2000-09-01

    Full Text Available Introduction: The purpose of this invitro investigation was to compare the anti-bacterial effect of normal saline and sodium hypochlorite (5.25 percent and 0.5 percent with calcium hydroxide used as intra canal dressing used in different time periods. Methods: 180 single-rooted freshly extracted teeth were selected. The crowns were resected of CEJ and the canal were flared to the same length using a number one Gates-Glidden. A suspension of selected strict and facultative anaerobic bacteria was placed inside the canals and incubated in anaerobic condition for 24 hours. Then the teeth were randomly assigned to 9 groups. Results: Group 1. Negative control; group 2. Positive control; group 3. instrumented using normal saile; group 4. instrumented using 0.5 percent sodium hypochlorite; grooup 5. instrumentation using 5.25 percent sodium hypochlorite; group 6. After instrumentation, 10 min. of calcium hydroxide was placed; group 7. after instrumentation 24h of calcium hydroxide was placed; group 8. After instrumentation 48h of calcium hydroxide was placed; group9. After instrumentation a week of calcium hydroxide was placed. Then paper points were used to get samples in each group. The samples incubated in anaerobid condition for 48 hours. The TSB turbidity was compared to mcfarland"s scale. Discussion: The results of this study indicates: Sodium hypochlorite in both concentrations were significantly more effective than normal saline. The one week calcium hydroxide group was significantly more effective than all other groups and was comparable to negative control group. The 24h and 48h calcium hydroxide groups did not have significant differences with each other or with the sodium hypochlorite groups. The 10 min. calcium hydroxide group was only comparable to normal saline group.

  5. Functional properties and in vitro antioxidant and antibacterial effectiveness of pigskin gelatin films incorporated with hydrolysable chestnut tannin.

    Science.gov (United States)

    Peña-Rodriguez, Cristina; Martucci, Josefa F; Neira, Laura M; Arbelaiz, Aitor; Eceiza, Arantxa; Ruseckaite, Roxana A

    2015-04-01

    The impact of the incorporation of 10% w/w of hydrolyzable chestnut tannin into pigskin gelatin (G) films plasticized with glycerol (Gly) on the physicochemical properties as well as the in vitro antioxidant and antibacterial effectiveness against food-borne pathogens such as Escherichia coli and Streptococcus aureus was investigated. A higher tendency to both redness (a*) and yellowness (b*) coloration characterized gelatin films incorporated with chestnut tannin. The reduced lightness (L) and transparency of gelatin-chestnut tannin films plasticized with 30% w/w Gly might be associated with certain degree of phase separation which provoked the migration of the plasticizer to the film surface. The incorporation of chestnut tannin and glycerol affected the chemical structure of the resultant films due to the establishment of hydrogen interactions between components as revealed by Fourier transform infrared spectroscopy. These interactions reduced gelatin crystallinity and seemed to be involved in the substantial decrease of the water uptake of films with tannin, irrespective of the glycerol level. Such interactions had minor effect on tensile properties being similar to those of the control films (without chestnut tannin) at the same glycerol level. Films modified with 10% w/w chestnut tannin showed significant (P tannin-free and chestnut tannin-containing gelatin films. The limited inhibitory activity of films incorporated with 10% w/w chestnut tannin against the selected bacteria evidenced by disk diffusion method probably resulted from the interactions within the film restricting the diffusion of the active agent into the agar medium. The more modest protective effect observed against a Gram-positive bacterium (S. aureus) was also discussed. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  6. Antibacterial Properties and Effects of Fruit Chilling and Extract Storage on Antioxidant Activity, Total Phenolic and Anthocyanin Content of Four Date Palm (Phoenix dactylifera) Cultivars.

    Science.gov (United States)

    Samad, Muhammad Azizan; Hashim, Siti Hajar; Simarani, Khanom; Yaacob, Jamilah Syafawati

    2016-03-26

    Phoenix dactylifera or date palm fruits are reported to contain natural compounds that exhibit antioxidant and antibacterial properties. This research aimed to study the effect of fruit chilling at 4 °C for 8 weeks, extract storage at -20 °C for 5 weeks, and extraction solvents (methanol or acetone) on total phenolic content (TPC), antioxidant activity and antibacterial properties of Saudi Arabian P. dactylifera cv Mabroom, Safawi and Ajwa, as well as Iranian P. dactylifera cv Mariami. The storage stability of total anthocyanin content (TAC) was also evaluated, before and after storing the extracts at -20 °C and 4 °C respectively, for 5 weeks. Mariami had the highest TAC (3.18 ± 1.40 mg cyd 3-glu/100 g DW) while Mabroom had the lowest TAC (0.54 ± 0.15 mg cyd 3-glu/100 g DW). The TAC of all extracts increased after storage. The chilling of date palm fruits for 8 weeks prior to solvent extraction elevated the TPC of all date fruit extracts, except for methanolic extracts of Mabroom and Mariami. All IC50 values of all cultivars decreased after the fruit chilling treatment. Methanol was a better solvent compared to acetone for the extraction of phenolic compounds in dates. The TPC of all cultivars extracts decreased after 5 weeks of extract storage. IC50 values of all cultivars extracts increased after extract storage except for the methanolic extracts of Safawi and Ajwa. Different cultivars exhibited different antibacterial properties. Only the methanolic extract of Ajwa exhibited antibacterial activity against all four bacteria tested: Staphylococcus aureus, Bacillus cereus, Serratia marcescens and Escherichia coli. These results could be useful to the nutraceutical and pharmaceutical industries in the development of natural compound-based products.

  7. Antibacterial Properties and Effects of Fruit Chilling and Extract Storage on Antioxidant Activity, Total Phenolic and Anthocyanin Content of Four Date Palm (Phoenix dactylifera Cultivars

    Directory of Open Access Journals (Sweden)

    Muhammad Azizan Samad

    2016-03-01

    Full Text Available Phoenix dactylifera or date palm fruits are reported to contain natural compounds that exhibit antioxidant and antibacterial properties. This research aimed to study the effect of fruit chilling at 4 °C for 8 weeks, extract storage at −20 °C for 5 weeks, and extraction solvents (methanol or acetone on total phenolic content (TPC, antioxidant activity and antibacterial properties of Saudi Arabian P. dactylifera cv Mabroom, Safawi and Ajwa, as well as Iranian P. dactylifera cv Mariami. The storage stability of total anthocyanin content (TAC was also evaluated, before and after storing the extracts at −20 °C and 4 °C respectively, for 5 weeks. Mariami had the highest TAC (3.18 ± 1.40 mg cyd 3-glu/100 g DW while Mabroom had the lowest TAC (0.54 ± 0.15 mg cyd 3-glu/100 g DW. The TAC of all extracts increased after storage. The chilling of date palm fruits for 8 weeks prior to solvent extraction elevated the TPC of all date fruit extracts, except for methanolic extracts of Mabroom and Mariami. All IC50 values of all cultivars decreased after the fruit chilling treatment. Methanol was a better solvent compared to acetone for the extraction of phenolic compounds in dates. The TPC of all cultivars extracts decreased after 5 weeks of extract storage. IC50 values of all cultivars extracts increased after extract storage except for the methanolic extracts of Safawi and Ajwa. Different cultivars exhibited different antibacterial properties. Only the methanolic extract of Ajwa exhibited antibacterial activity against all four bacteria tested: Staphylococcus aureus, Bacillus cereus, Serratia marcescens and Escherichia coli. These results could be useful to the nutraceutical and pharmaceutical industries in the development of natural compound-based products.

  8. The effect of cell immobilization on the antibacterial activity of Lactobacillus reuteri DPC16 cells during passage through a simulated gastrointestinal tract system.

    Science.gov (United States)

    Zhao, Qian; Maddox, Ian S; Mutukumira, Anthony; Lee, Sung Je; Shu, Quan

    2012-10-01

    Cell immobilization has the ability to influence the survival and functional characteristics of probiotic bacterial strains in harsh environments. This study investigated the effect of cell immobilization and passage through a simulated gastrointestinal tract (GI) on the antibacterial activity of Lactobacillus reuteri DPC16. Antibacterial activity, reuterin production and diol dehydratase activity were assayed in recovered isolates of L. reuteri that had been immobilized in Ca alginate-skim milk, and incubated in simulated GI fluids. Among all the recovered isolates tested, any that had undergone immobilization followed by immediate recovery of the cells without subsequent incubation in any fluids demonstrated the highest reuterin production, antimicrobial activity and diol dehydratase enzyme activity. L. reuteri DPC16 cells that had been immobilized, incubated in simulated GI fluids, and subsequently recovered from the beads often showed some loss of antimicrobial activity compared to the immobilized cells. The data confirm that the process of immobilization of L. reuteri in Ca alginate-skim milk, rather than the passage through simulated GI fluids, resulted in enhanced antibacterial activity. This is attributed to increased diol dehydratase activity, resulting in increased reuterin production.

  9. Synergistic antibacterial effects of herbal extracts and antibiotics on methicillin-resistant Staphylococcus aureus: A computational and experimental study.

    Science.gov (United States)

    Kuok, Chiu-Fai; Hoi, Sai-On; Hoi, Chi-Fai; Chan, Chi-Hong; Fong, Io-Hong; Ngok, Cheong-Kei; Meng, Li-Rong; Fong, Pedro

    2017-04-01

    Antibiotic resistance has become a serious global concern, and the discovery of antimicrobial herbal constituents may provide valuable solutions to overcome the problem. In this study, the effects of therapies combining antibiotics and four medicinal herbs on methicillin-resistant Staphylococcus aureus (MRSA) were investigated. Specifically, the synergistic effects of Magnolia officinalis, Verbena officinalis, Momordica charantia, and Daphne genkwa in combination with oxacillin or gentamicin against methicillin-resistant (ATCC43300) and methicillin-susceptible (ATCC25923) S. aureus were examined. In vitro susceptibility and synergistic testing were performed to measure the minimum inhibitory concentration and fractional inhibitory concentration (FIC) index of the antibiotics and medicinal herbs against MRSA and methicillin-susceptible S. aureus. To identify the active constituents in producing these synergistic effects, in silico molecular docking was used to investigate the binding affinities of 139 constituents of the four herbs to the two common MRSA inhibitory targets, penicillin binding proteins 2a (PBP2a) and 4 (PBP4). The physicochemical and absorption, distribution, metabolism, and excretion properties and drug safety profiles of these compounds were also analyzed. D. genkwa extract potentiated the antibacterial effects of oxacillin against MRSA, as indicated by an FIC index value of 0.375. M. officinalis and V. officinalis produced partial synergistic effects when combined with oxacillin, whereas M. charantia was found to have no beneficial effects in inhibiting MRSA. Overall, tiliroside, pinoresinol, magnatriol B, and momorcharaside B were predicted to be PBP2a or PBP4 inhibitors with good drug-like properties. This study identifies compounds that deserve further investigation with the aim of developing therapeutic agents to modulate the effect of antibiotics on MRSA. Impact statement Antibiotic resistant is a well-known threat to global health and

  10. In Vitro Parallel Evaluation of Antibacterial Activity and Cytotoxicity of Commercially Available Silver-Containing Wound Dressings.

    Science.gov (United States)

    Yunoki, Shunji; Kohta, Masushi; Ohyabu, Yoshimi; Iwasaki, Tetsuji

    2015-01-01

    This study evaluated the in vitro antibacterial activity and cytotoxicity of various commercially available silver-containing dressings (Ag dressing). Biohesive Ag (hydrocolloid, silver sulfadiazine), Aquacel® Ag (nonwoven fabric, ionic silver [Ag]), Algisite™ Ag (nonwoven fabric, Ag), Mepilex® Ag (foam, silver sulfate), and PolyMem® Ag (foam, nanocrystalline silver) were tested for characteristics of Ag release, antibacterial activity, and cytotoxicity. The release of Ag was investigated in cell culture medium at immersion periods of 6, 24, and 48 hours. The antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa were accessed by a disc diffusion test. The cytotoxicity was evaluated using V79 cells, by an extraction method. The cytotoxicity was not a monotonic function of the antibacterial activity among the Ag dressings and could not be simply explained by Ag-release properties. Biohesive Ag was regarded as a slow-release Ag dressing, showing the lowest cytotoxicity, while the antibacterial activity was classified as "strong" or "significant" against the two species of bacteria. Aquacel Ag and Algisite Ag showed higher antibacterial activity and cytotoxic effects, which were supported by the higher Ag release. Mepilex Ag showed the highest release of Ag, and the cytotoxicity was the highest among the Ag dressings. However, the antibacterial activity was classified as "significant" or "no activity" for P. aeruginosa and S. aureus, respectively. PolyMem Ag showed the lowest Ag release, and the antibacterial activity classified as "significant" or "no activity" for S. aureus and P. aeruginosa, respectively, whereas the cytotoxicity was similar to those of Aquacel Ag and Algisite Ag. The efficacy and adverse effects of the Ag dressings revealed differences that should be considered by clinicians during wound management.

  11. STRONG FIELD EFFECTS ON EMISSION LINE PROFILES: KERR BLACK HOLES AND WARPED ACCRETION DISKS

    International Nuclear Information System (INIS)

    Wang Yan; Li Xiangdong

    2012-01-01

    If an accretion disk around a black hole is illuminated by hard X-rays from non-thermal coronae, fluorescent iron lines will be emitted from the inner region of the accretion disk. The emission line profiles will show a variety of strong field effects, which may be used as a probe of the spin parameter of the black hole and the structure of the accretion disk. In this paper, we generalize the previous relativistic line profile models by including both the black hole spinning effects and the non-axisymmetries of warped accretion disks. Our results show different features from the conventional calculations for either a flat disk around a Kerr black hole or a warped disk around a Schwarzschild black hole by presenting, at the same time, multiple peaks, rather long red tails, and time variations of line profiles with the precession of the disk. We show disk images as seen by a distant observer, which are distorted by the strong gravity. Although we are primarily concerned with the iron K-shell lines in this paper, the calculation is general and is valid for any emission lines produced from a warped accretion disk around a black hole.

  12. Antibacterial Metallic Touch Surfaces

    Directory of Open Access Journals (Sweden)

    Victor M. Villapún

    2016-08-01

    Full Text Available Our aim is to present a comprehensive review of the development of modern antibacterial metallic materials as touch surfaces in healthcare settings. Initially we compare Japanese, European and US standards for the assessment of antimicrobial activity. The variations in methodologies defined in these standards are highlighted. Our review will also cover the most relevant factors that define the antimicrobial performance of metals, namely, the effect of humidity, material geometry, chemistry, physical properties and oxidation of the material. The state of the art in contact-killing materials will be described. Finally, the effect of cleaning products, including disinfectants, on the antimicrobial performance, either by direct contact or by altering the touch surface chemistry on which the microbes attach, will be discussed. We offer our outlook, identifying research areas that require further development and an overview of potential future directions of this exciting field.

  13. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth.

    Science.gov (United States)

    Dhariwal, Neha Shashikant; Hugar, Shivayogi M; Harakuni, Sheetal; Sogi, Suma; Assudani, Harsha G; Mistry, Laresh Naresh

    2016-01-01

    In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric) and Camellia sinensis (green tea) as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. SPSS 18 software using Chi-square test was used for statistical analysis. The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric) showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001). The least effective was C. sinensis (green tea). The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important role in eradicating the population of predominant micro-organisms in treating these teeth with

  14. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth

    Directory of Open Access Journals (Sweden)

    Neha Shashikant Dhariwal

    2016-01-01

    Full Text Available Context: In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. Aim: To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric and Camellia sinensis (green tea as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. Materials and Methods: Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. Statistical Analysis: SPSS 18 software using Chi-square test was used for statistical analysis. Results: The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001. The least effective was C. sinensis (green tea. Conclusion: The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important

  15. Non trivial effect of strong high-frequency excitation on a nonlinear controlled system

    DEFF Research Database (Denmark)

    Fidlin, A.; Thomsen, Jon Juel

    2004-01-01

    due to control is usually high compared to uncontrolled systems. A standard optimal controller for a standard nonlinear system (a movable cart used to balance a pendulum vertically) is shown to exhibit pronounced bias error in presence of HF-excitation. The bias increases with increased excitation......Nontrivial effects of high-frequency excitation on mechanical uncontrolled systems have been investigated intensively in the last decade. Some of these effects are usually used in controlled systems in form of dither to smoothen out undesired friction and hysteresis. However the level of damping...... intensity, but it also increases with the increased control power. Analytic prediction for the bias shows, the interaction between fast excitation and strong damping terms in the control system to be the cause of the permanent control error. A "slow observer" ignoring fast motions is shown...

  16. Trapped in the extinction vortex? Strong genetic effects in a declining vertebrate population

    Directory of Open Access Journals (Sweden)

    Larsson Mikael

    2010-02-01

    Full Text Available Abstract Background Inbreeding and loss of genetic diversity are expected to increase the extinction risk of small populations, but detailed tests in natural populations are scarce. We combine long-term population and fitness data with those from two types of molecular markers to examine the role of genetic effects in a declining metapopulation of southern dunlins Calidris alpina schinzii, an endangered shorebird. Results The decline is associated with increased pairings between related individuals, including close inbreeding (as revealed by both field observations of parentage and molecular markers. Furthermore, reduced genetic diversity seems to affect individual fitness at several life stages. Higher genetic similarity between mates correlates negatively with the pair's hatching success. Moreover, offspring produced by related parents are more homozygous and suffer from increased mortality during embryonic development and possibly also after hatching. Conclusions Our results demonstrate strong genetic effects in a rapidly declining population, emphasizing the importance of genetic factors for the persistence of small populations.

  17. Strong matrix effect in low-energy He+ ion scattering from carbon

    International Nuclear Information System (INIS)

    Mikhailov, S.N.; Van den Oetelaar, L.C.A.; Brongersma, H.H.

    1994-01-01

    In low-energy ion scattering the contribution of neutralization processes to the scattered ion yield is very important in quantification. Neutralization of low-energy (1-3.5 keV) He + ions by carbon is found to be much stronger for graphitic than for carbidic carbon. The ion fraction for graphitic carbon for 2.5 keV 3 He + scattering over 136 is about 60 times lower than that for carbidic carbon. For the 4 He + isotope the effect is even larger. Such a strong matrix effect for one element has not been measured before in low-energy (1-3.5 keV) inert-gas ion scattering. The neutralization behaviour is discussed in terms of a special quasi-resonant neutralization process for graphite. ((orig.))

  18. Strongly correlated Fermi-systems: Non-Fermi liquid behavior, quasiparticle effective mass and their interplay

    Energy Technology Data Exchange (ETDEWEB)

    Shaginyan, V.R. [Petersburg Nuclear Physics Institute, RAS, Gatchina 188300 (Russian Federation); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)], E-mail: vrshag@thd.pnpi.spb.ru; Amusia, M.Ya. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Popov, K.G. [Komi Science Center, Ural Division, RAS, Syktyvkar 167982 (Russian Federation)

    2009-06-15

    Basing on the density functional theory of fermion condensation, we analyze the non-Fermi liquid behavior of strongly correlated Fermi-systems such as heavy-fermion metals. When deriving equations for the effective mass of quasiparticles, we consider solids with a lattice and homogeneous systems. We show that the low-temperature thermodynamic and transport properties are formed by quasiparticles, while the dependence of the effective mass on temperature, number density, magnetic fields, etc., gives rise to the non-Fermi liquid behavior. Our theoretical study of the heat capacity, magnetization, energy scales, the longitudinal magnetoresistance and magnetic entropy are in good agreement with the remarkable recent facts collected on the heavy-fermion metal YbRh{sub 2}Si{sub 2}.

  19. Strongly correlated Fermi-systems: Non-Fermi liquid behavior, quasiparticle effective mass and their interplay

    International Nuclear Information System (INIS)

    Shaginyan, V.R.; Amusia, M.Ya.; Popov, K.G.

    2009-01-01

    Basing on the density functional theory of fermion condensation, we analyze the non-Fermi liquid behavior of strongly correlated Fermi-systems such as heavy-fermion metals. When deriving equations for the effective mass of quasiparticles, we consider solids with a lattice and homogeneous systems. We show that the low-temperature thermodynamic and transport properties are formed by quasiparticles, while the dependence of the effective mass on temperature, number density, magnetic fields, etc., gives rise to the non-Fermi liquid behavior. Our theoretical study of the heat capacity, magnetization, energy scales, the longitudinal magnetoresistance and magnetic entropy are in good agreement with the remarkable recent facts collected on the heavy-fermion metal YbRh 2 Si 2 .

  20. Antibacterial properties of copper iodide-doped glass ionomer-based materials and effect of copper iodide nanoparticles on collagen degradation.

    Science.gov (United States)

    Renné, Walter G; Lindner, Amanda; Mennito, Anthony S; Agee, Kelli A; Pashley, David H; Willett, Daniel; Sentelle, David; Defee, Michael; Schmidt, Michael; Sabatini, Camila

    2017-01-01

    This study investigated the antibacterial properties and micro-hardness of polyacrylic acid (PAA)-coated copper iodide (CuI) nanoparticles incorporated into glass ionomer-based materials, and the effect of PAA-CuI on collagen degradation. PAA-CuI nanoparticles were incorporated into glass ionomer (GI), Ionofil Molar AC, and resin-modified glass ionomer (RMGI), Vitrebond, at 0.263 wt%. The antibacterial properties against Streptococcus mutans (n = 6/group) and surface micro-hardness (n = 5/group) were evaluated. Twenty dentin beams were completely demineralized in 10 wt% phosphoric acid and equally divided in two groups (n = 10/group) for incubation in simulated body fluid (SBF) or SBF containing 1 mg/ml PAA-CuI. The amount of dry mass loss and hydroxyproline (HYP) released were quantified. Kruskal-Wallis, Student's t test, two-way ANOVA, and Mann-Whitney were used to analyze the antibacterial, micro-hardness, dry mass, and HYP release data, respectively (p glass ionomer matrix yielded significant reduction (99.999 %) in the concentration of bacteria relative to the control groups. While micro-hardness values of PAA-CuI-doped GI were no different from its control, PAA-CuI-doped RMGI demonstrated significantly higher values than its control. A significant decrease in dry mass weight was shown only for the control beams (10.53 %, p = 0.04). Significantly less HYP was released from beams incubated in PAA-CuI relative to the control beams (p glass ionomer-based materials as they greatly enhance their antibacterial properties and reduce collagen degradation without an adverse effect on their mechanical properties. The use of copper-doped glass ionomer-based materials under composite restorations may contribute to an increased longevity of adhesive restorations, because of their enhanced antibacterial properties and reduced collagen degradation.

  1. Bactericidal Effect of Strong Acid Electrolyzed Water against Flow Enterococcus faecalis Biofilms.

    Science.gov (United States)

    Cheng, Xiaogang; Tian, Yu; Zhao, Chunmiao; Qu, Tiejun; Ma, Chi; Liu, Xiaohua; Yu, Qing

    2016-07-01

    This study evaluated the bactericidal effect of strong acid electrolyzed water (SAEW) against flow Enterococcus faecalis biofilm and its potential application as a root canal irrigant. Flow E. faecalis biofilms were generated under a constant shear flow in a microfluidic system. For comparison, static E. faecalis biofilms were generated under a static condition on coverslip surfaces. Both the flow and static E. faecalis biofilms were treated with SAEW. Sodium hypochlorite (NaOCl, 5.25%) and normal saline (0.9%) were included as the controls. Bacterial reductions were evaluated using confocal laser scanning microscopy and the cell count method. Morphological changes of bacterial cells were observed using scanning electron microscopy. The confocal laser scanning microscopic and cell count results showed that SAEW had a bactericidal effect similar to that of 5.25% NaOCl against both the flow and static E. faecalis biofilms. The scanning electron microscopic results showed that smooth, consecutive, and bright bacteria surfaces became rough, shrunken, and even lysed after treated with SAEW, similar to those in the NaOCl group. SAEW had an effective bactericidal effect against both the flow and static E. faecalis biofilms, and it might be qualified as a root canal irrigant for effective root canal disinfection. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Long-term effects of the strong African American families program on youths' alcohol use.

    Science.gov (United States)

    Brody, Gene H; Chen, Yi-Fu; Kogan, Steven M; Murry, Velma McBride; Brown, Anita C

    2010-04-01

    This report extends earlier accounts by addressing the effects of the Strong African American Families (SAAF) program across 65 months. Two hypotheses were tested: (a) Rural African American youths randomly assigned to participate in SAAF would demonstrate lower rates of alcohol use than would control youths more than 5 years later, and (b) SAAF's effects on deterring the onset of alcohol use in early adolescence would carry forward to mediate the program's long-term effects. African American youths in rural Georgia (mean age at pretest = 10.8 years) were assigned randomly to the SAAF group (n = 369) or to a control group (n = 298). Past-month alcohol use was assessed at pretest and at 9, 18, 29, 53, and 65 months after pretest. SAAF participants increased their alcohol use at a slower rate than did adolescents in the control condition across the follow-up assessments. At the 65-month assessment, SAAF participants reported having drunk alcohol half as often as did youths in the control group. Consistent with the second hypothesis, SAAF's effects on deterring initiation carried forward to account for its effects on alcohol use across time. Training in protective parenting processes and self-regulatory skills during preadolescence may contribute to a self-sustaining trajectory of disinterest in and avoidance of alcohol use during adolescence when peers begin to model and sanction it. (c) 2010 APA, all rights reserved

  3. Antibacterial activity of Nigella sativa seed essential oil and effect of different extraction methods on content its active principle, thymoquinone

    Czech Academy of Sciences Publication Activity Database

    Kokoška, L.; Havlík, J.; Valterová, Irena; Sovová, Helena; Sajfrtová, Marie; Maršík, Petr

    2006-01-01

    Roč. 72, č. 11 (2006), s. 1008 ISSN 0032-0943. [Annual Congress on Medicinal Plant Research. 29.08.2006-02.09.2006, Helsinki] R&D Projects: GA ČR GA104/06/1174 Institutional research plan: CEZ:AV0Z40550506 Keywords : antibacterial activity * Nigella * extraction * thymoquinone Subject RIV: CE - Biochemistry

  4. Pharmacokinetics and effects on bowel and throat microflora of oral levofloxacin as antibacterial prophylaxis in neutropenic patients with haematological malignancies

    NARCIS (Netherlands)

    Timmers, G J; Dijstelbloem, Y; Simoons-Smit, A M; van Winkelhoff, A J; Touw, D J; Vandenbroucke-Grauls, C M J E; Huijgens, P C

    Gram-positive breakthrough infections pose a major drawback to the use of quinolones for antibacterial prophylaxis in neutropenic patients. Levofloxacin offers the advantage of an augmented Gram-positive spectrum and may potentially overcome this problem. In an open-label, clinical pilot study, we

  5. Antibacterial-induced nephrotoxicity in the newborn.

    Science.gov (United States)

    Fanos, V; Cataldi, L

    1999-03-01

    . Antibacterial-induced nephrotoxicity is an important parameter to be considered when treating the newborn and this is particularly true when use of a combination of different antibacterials and/or drugs with a nephrotoxic potential is being considered. However, other parameters, such as antibacterial spectrum, pharmacokinetics, post-antibacterial effect, clinical efficacy, general adverse effect profile and cost, must also be considered in the choice of antibacterial therapy in the neonate. Knowledge of the renal safety of antibacterials and the correct approach to therapeutic drug monitoring may be useful elements for preventing iatrogenic renal disorders.

  6. Fitness is strongly influenced by rare mutations of large effect in a microbial mutation accumulation experiment.

    Science.gov (United States)

    Heilbron, Karl; Toll-Riera, Macarena; Kojadinovic, Mila; MacLean, R Craig

    2014-07-01

    Our understanding of the evolutionary consequences of mutation relies heavily on estimates of the rate and fitness