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Sample records for effective antimicrobial activity

  1. Antimicrobial Activities of Chemokines: Not Just a Side-Effect?

    PubMed Central

    Wolf, Marlene; Moser, Bernhard

    2012-01-01

    The large family of chemoattractant cytokines (chemokines) embraces multiple, in part unrelated functions that go well beyond chemotaxis. Undoubtedly, the control of immune cell migration (chemotaxis) is the single, unifying response mediated by all chemokines, which involves the sequential engagement of chemokine receptors on migrating target cells. However, numerous additional cellular responses are mediated by some (but not all) chemokines, including angiogenesis, tumor cell growth, T-cell co-stimulation, and control of HIV-1 infection. The recently described antimicrobial activity of several chemokines is of particular interest because antimicrobial peptides are thought to provide an essential first-line defense against invading microbes at the extremely large body surfaces of the skin, lungs, and gastrointestinal-urinary tract. Here we summarize the current knowledge about chemokines with antimicrobial activity and discuss their potential contribution to the control of bacterial infections that may take place at the earliest stage of antimicrobial immunity. In the case of homeostatic chemokines with antimicrobial function, such as CXCL14, we propose an immune surveillance function in healthy epithelial tissues characterized by low-level exposure to environmental microbes. Inflammatory chemokines, i.e., chemokines that are produced in tissue cells in response to microbial antigens (such as pathogen-associated molecular patterns) may be more important in orchestrating the cellular arm in antimicrobial immunity. PMID:22837760

  2. Effects of different heat treatments on lysozyme quantity and antimicrobial activity of jenny milk.

    PubMed

    Cosentino, C; Labella, C; Elshafie, H S; Camele, I; Musto, M; Paolino, R; D'Adamo, C; Freschi, P

    2016-07-01

    Thermal treatments are used to improve milk microbial safety, shelf life, and biological activity of some of its components. However, thermal treatments can reduce the nutritional quality of milk, affecting the molecular structure of milk proteins, such as lysozyme, which is a very important milk component due to its antimicrobial effect against gram-positive bacteria. Jenny milk is characterized by high lysozyme content. For this reason, in the last few years, it has been used as an antimicrobial additive in dairy products as an alternative to hen egg white lysozyme, which can cause allergic reactions. This study aimed to investigate the effect of pasteurization and condensation on the concentration and antimicrobial activity of lysozyme in jenny milk. Furthermore, lysozyme quantity and activity were tested in raw and pasteurized milk after condensation at 40 and 20% of the initial volume. Reversed-phase HPLC was performed under fluorescence detection to monitor lysozyme in milk samples. We evaluated the antimicrobial activity of the tested milk against Bacillus megaterium, Bacillus mojavensis, Clavibacter michiganensis, Clostridium tyrobutyricum, Xanthomonas campestris, and Escherichia coli. Condensation and pasteurization did not affect the concentration or antimicrobial activity of lysozyme in jenny milk, except for B. mojaventis, which showed resistance to lysozyme in milk samples subjected to heat treatments. Moreover, lysozyme in jenny milk showed antimicrobial activity similar to synthetic antibiotics versus some gram-positive strains and also versus the gram-negative strain X. campestris. PMID:27157571

  3. Antimicrobial activity of isopteropodine.

    PubMed

    García, Rubén; Cayunao, Cesia; Bocic, Ronny; Backhouse, Nadine; Delporte, Carle; Zaldivar, Mercedes; Erazo, Silvia

    2005-01-01

    Bioassay-directed fractionation for the determination of antimicrobial activity of Uncaria tomentosa, has led to the isolation of isopteropodine (0.3%), a known Uncaria pentacyclic oxindol alkaloid that exhibited antibacterial activity against Gram positive bacteria. PMID:16042336

  4. Effect of high hydrostatic pressure on antimicrobial activity and quality of Manuka honey.

    PubMed

    Al-Habsi, Nasser A; Niranjan, Keshavan

    2012-12-01

    The antimicrobial activity of Manuka honey is of major interest to beekeepers and the honey industry. In this study, the effect of high hydrostatic pressure and thermal treatments on antimicrobial activity and quality parameters (principally, diastase number and hydroxymethylfurfural levels (HMF)) of Manuka honey were investigated. The honey was subjected to different pressures (100-800MPa) at 25°C for a range of holding times (15-120min). The antimicrobial activity was found to increase with applied pressure for a given holding time, while the diastase number and HMF levels remained, more or less, unaffected. The percentage inhibition in microbial growth correlated linearly (R(2)=0.94) with methyglyoxal concentration in the honey after treatment over the entire range of pressure, temperature and holding times studied. Maximum percentage inhibition (78.83%) was achieved when honey was subjected to 800MPa compared to the control (57.93%). Thermal treatments at higher temperatures were found to have a detrimental effect on antimicrobial activity based on percentage inhibition as well as methylglyoxal content. Thus, it can be concluded that the levels of methylglyoxal, and therefore the antimicrobial effect of Manuka honey, can be enhanced by using high pressure processing without adversely affecting honey quality. PMID:22953879

  5. Effects of nisin on the antimicrobial activity of d-limonene and its nanoemulsion.

    PubMed

    Zhang, Zijie; Vriesekoop, Frank; Yuan, Qipeng; Liang, Hao

    2014-05-01

    d-Limonene has been considered to be a safer alternative compared to synthetic antimicrobial food additives. However, its hydrophobic and oxidative nature has limited its application in foods. The purpose of this research was to study effects of nisin on the antimicrobial activity of d-limonene and its nanoemulsion and develop a novel antimicrobial delivery system by combining the positive effect of these two antibacterial agents at the same time. By the checkerboard method, both the synergistic and additive effects of d-limonene and nisin were found against four selected food-related microorganisms. Then, d-limonene nanoemulsion with or without nisin was prepared by catastrophic phase inversion method, which has shown good droplet size and stability. The positive effects and outstanding antimicrobial activity of d-limonene nanoemulsion with nisin were confirmed by MICs comparison, scanning electron microscopy and determination of cell constituents released. Overall, the research described in the current article would be helpful in developing a more effective antimicrobial system for the production and preservation of foods. PMID:24360455

  6. Automation of antimicrobial activity screening.

    PubMed

    Forry, Samuel P; Madonna, Megan C; López-Pérez, Daneli; Lin, Nancy J; Pasco, Madeleine D

    2016-03-01

    Manual and automated methods were compared for routine screening of compounds for antimicrobial activity. Automation generally accelerated assays and required less user intervention while producing comparable results. Automated protocols were validated for planktonic, biofilm, and agar cultures of the oral microbe Streptococcus mutans that is commonly associated with tooth decay. Toxicity assays for the known antimicrobial compound cetylpyridinium chloride (CPC) were validated against planktonic, biofilm forming, and 24 h biofilm culture conditions, and several commonly reported toxicity/antimicrobial activity measures were evaluated: the 50 % inhibitory concentration (IC50), the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC). Using automated methods, three halide salts of cetylpyridinium (CPC, CPB, CPI) were rapidly screened with no detectable effect of the counter ion on antimicrobial activity. PMID:26970766

  7. Antimicrobial activity of antiproteinases.

    PubMed

    Sallenave, J M

    2002-04-01

    Low-molecular-mass neutrophil elastase inhibitors have been shown to be important in the control of lung inflammation. In addition to inhibiting the enzyme neutrophil elastase, these low-molecular-mass compounds (10 kDa) have been shown to have other activities. For example, secretory leucocyte proteinase inhibitor (SLPI) and elastase-specific inhibitor/SKALP (skin-derived antileucoproteinase)/elafin have also been shown to have "defensin"-like antimicrobial activities. Indeed, these inhibitors have antimicrobial properties in vitro against bacteria, fungi and, potentially, HIV. In addition, we have shown, using an adenovirus-mediated gene transfer overexpression strategy, that elafin is also active against Pseudomonas aeruginosa infection in mice in vivo. The mechanism of action is currently under investigation. In addition to these direct or indirect effects on microbes, it has been shown that lipopolysaccharide is able to up-regulate SPLI production in macrophages in vitro, and that the addition of recombinant SLPI to human monocytes or the transfection of macrophages with SPLI can down-regulate pro-inflammatory mediators such as tumour necrosis factor, presumably to limit self-damaging excessive inflammation. Using viral gene transfer vectors, we are currently investigating the potential of these inhibitors in various models of inflammation in vivo. PMID:12023836

  8. Essential oils--their antimicrobial activity against Escherichia coli and effect on intestinal cell viability.

    PubMed

    Fabian, Dusan; Dusan, Fabian; Sabol, Marián; Marián, Sabol; Domaracká, Katarína; Katarína, Domaracká; Bujnáková, Dobroslava; Dobroslava, Bujnáková

    2006-12-01

    Essential oils are known to possess antimicrobial activity against a wide spectrum of bacteria. The main objective of this study was to evaluate possible harmful effects of four commonly used essential oils and their major components on intestinal cells. Antimicrobial activity of selected plant extracts against enteroinvasive Escherichia coli was dose dependent. However, doses of essential oils with the ability to completely inhibit bacterial growth (0.05%) showed also relatively high cytotoxicity to intestinal-like cells cultured in vitro. Lower doses of essential oils (0.01%) had only partial antimicrobial activity and their damaging effect on Caco-2 cells was only modest. Cell death assessment based on morphological and viability staining followed by fluorescence microscopy showed that essential oils of cinnamon and clove and their major component eugenol had almost no cytotoxic effect at lower doses. Although essential oil of oregano and its component carvacrol slightly increased the incidence of apoptotic cell death, they showed extensive antimicrobial activity even at lower concentrations. Relatively high cytotoxicity was demonstrated by thyme oil, which increased both apoptotic and necrotic cell death incidence. In contrast, its component thymol showed no cytotoxic effect as well as greatly-reduced ability to inhibit visible growth of the chosen pathogen in the doses used. On the other hand, the addition of all essential oils and their components at lower doses, with the exception of thyme oil, to bacterial suspension significantly reduced the cytotoxic effect of E. coli on Caco-2 cells after 1h culture. In conclusion, it is possible to find appropriate doses of essential oils showing both antimicrobial activity and very low detrimental effect on intestinal cells. PMID:16919909

  9. Evaluation of antimicrobial activity and bronchodialator effect of a polyherbal drug-Shrishadi

    PubMed Central

    Kajaria, Divya Kumari; Gangwar, Mayank; Kumar, Dharmendra; Kumar Sharma, Amit; Tilak, Ragini; Nath, Gopal; Tripathi, Yamini Bhusan; Tripathi, JS; Tiwari, SK

    2012-01-01

    Objective To investigate antimicrobial and bronchodialator effect of hydroalcholic extract of polyherbal drug Shirishadi containing Shirisha (Albezzia lebbeck), Nagarmotha (Cyprus rotandus) & Kantakari (Solanum xanthocarpum). Methods Antimicrobial activity was evaluated by disc diffusion method and MIC, MBC, MFC were calculated by micro dilution method. Hydroalcholic extract of this preparation was investigated for its phytochemical analysis, phenol and flavonoid were determined by spectrophotometric method and in vivo bronchodilator effect was analysed by convulsion time. Results The phytochemical tests revealed presence of alkaloids, anthraquinones, carbohydrates, flavonoids, saponins and tannins. The antimicrobial result showed the MIC of 6.25 mg/mL against Staphylococcus aureus and 12.5 mg/mL for Escherichia coli and 12.5 mg/mL against remaining bacteria tested, with strong antifungal activity. The maximum inhibition zone is found against Pseudomonas aeruginosa with MIC 16 mg/mL. Drug showed significant bronchodilator effect with 27.86% & 36.13% increase in preconvulsion time of guinea pigs pretreated with 100 & 200 mg/kg body weight of extract. Conclusions The study reveals that the extracts possess antibacterial activity and antifungal activity in a dose dependent manner. This antimicrobial property may be due to presence of several saponins, further studies are highly needed for the drug development. PMID:23569869

  10. Heat treatment effects on the antimicrobial activity of macrolide and lincosamide antibiotics in milk.

    PubMed

    Zorraquino, M A; Althaus, R L; Roca, M; Molina, M P

    2011-02-01

    Antibiotic residues in milk can cause serious problems for consumers and the dairy industry. Heat treatment of milk may diminish the antimicrobial activity of these antibiotic residues. This study analyzed the effect of milk processing (60 °C for 30 min, 120 °C for 20 min, and 140 °C for 10 s) on the antimicrobial activity of milk samples fortified with three concentrations of three macrolides (erythromycin: 20, 40 and 80 μg/liter; spiramycin: 100, 200, and 400 μg/liter; and tylosin: 500, 1,000, and 2,000 μg/liter) and one lincosamide (lincomycin: 1,000, 2,000, and 4,000 μg/liter). To measure the loss of antimicrobial activity, a bioassay based on the growth inhibition of Micrococcus luteus was done. The data were analyzed using a multiple linear regression model. The results indicate that treatment at 120 °C for 20 min produces inactivation percentages of 93% (erythromycin), 64% (spiramycin), 51% (tylosin), and 5% (lincomycin), while treatment at 140 °C for 10 s results in generally lower percentages (30% erythromycin, 35% spiramycin, 12% tylosin, and 5% lincomycin). The lowest loss or lowest reduction of antimicrobial activity (21% erythromycin and 13% spiramycin) was obtained by treatment at 60 °C for 30 min. PMID:21333154

  11. Effects of heating, storage, and ultraviolet exposure on antimicrobial activity of garlic juice.

    PubMed

    Al-Waili, Noori S; Saloom, Khelod Y; Akmal, M; Al-Waili, Thia N; Al-Waili, Ali N; Al-Waili, Hamza; Ali, Amjed; Al-Sahlani, Karem

    2007-03-01

    This study was designed to investigate the effect of heating, storage, and ultraviolet exposure on antimicrobial activity of garlic juice and its bacteriocidal activity against common human pathogens. Antimicrobial activity of fresh garlic juice was tested against Escherichia coli, Staphylococcus aureus, Streptococcus hemolyticus B, S. hemolyticus A, Klebsiella sp., Shigella dysenteriae, and Candida albicans using the disc method. The dilution method was performed by addition of garlic juice to broth media to obtain 1-100% concentrations as vol/vol or wt/vol. Garlic juice was used after 24 hours of storage at 4 degrees C, heating to 100 degrees C for 5 minutes, 10 minutes, 30 minutes, and 60 minutes, heating to 80 degrees C for 60 minutes, and 4 hours of exposure to ultraviolet light. Re-culture of specimens taken from garlic-induced negative media was performed in fresh broth free of garlic juice. Results showed that all the isolates were sensitive to fresh garlic juice; the most sensitive was C. albicans, and the least sensitive was S. hemolyticus A. Heating to 100 degrees C for 30 and 60 minutes completely abolished the antimicrobial activity, while heating for 5 and 10 minutes, storage for 24 hours, and 4 hours of ultraviolet exposure decreased it. Garlic juice was bactericidal at concentrations of 5% and more. Thus garlic juice has marked antimicrobial activity that makes it a potential agent to be tested in clinical trials. The antimicrobial activity was compromised by storage and heating; therefore it is advisable to use fresh garlic and avoid boiling it for more than 5 minutes during cooking. PMID:17472490

  12. Antimicrobial activity of resveratrol analogues.

    PubMed

    Chalal, Malik; Klinguer, Agnès; Echairi, Abdelwahad; Meunier, Philippe; Vervandier-Fasseur, Dominique; Adrian, Marielle

    2014-01-01

    Stilbenes, especially resveratrol and its derivatives, have become famous for their positive effects on a wide range of medical disorders, as indicated by a huge number of published studies. A less investigated area of research is their antimicrobial properties. A series of 13 trans-resveratrol analogues was synthesized via Wittig or Heck reactions, and their antimicrobial activity assessed on two different grapevine pathogens responsible for severe diseases in the vineyard. The entire series, together with resveratrol, was first evaluated on the zoospore mobility and sporulation level of Plasmopara viticola (the oomycete responsible for downy mildew). Stilbenes displayed a spectrum of activity ranging from low to high. Six of them, including the most active ones, were subsequently tested on the development of Botrytis cinerea (fungus responsible for grey mold). The results obtained allowed us to identify the most active stilbenes against both grapevine pathogens, to compare the antimicrobial activity of the evaluated series of stilbenes, and to discuss the relationship between their chemical structure (number and position of methoxy and hydroxy groups) and antimicrobial activity. PMID:24918540

  13. Antimicrobial Activity of Essential Oils against Streptococcus mutans and their Antiproliferative Effects

    PubMed Central

    Galvão, Lívia Câmara de Carvalho; Furletti, Vivian Fernandes; Bersan, Salete Meyre Fernandes; da Cunha, Marcos Guilherme; Ruiz, Ana Lúcia Tasca Góis; de Carvalho, João Ernesto; Sartoratto, Adilson; Rehder, Vera Lúcia Garcia; Figueira, Glyn Mara; Teixeira Duarte, Marta Cristina; Ikegaki, Masarahu; de Alencar, Severino Matias; Rosalen, Pedro Luiz

    2012-01-01

    This study aimed to evaluate the activity of essential oils (EOs) against Streptococcus mutans biofilm by chemically characterizing their fractions responsible for biological and antiproliferative activity. Twenty EO were obtained by hydrodistillation and submitted to the antimicrobial assay (minimum inhibitory (MIC) and bactericidal (MBC) concentrations) against S. mutans UA159. Thin-layer chromatography and gas chromatography/mass spectrometry were used for phytochemical analyses. EOs were selected according to predetermined criteria and fractionated using dry column; the resulting fractions were assessed by MIC and MBC, selected as active fractions, and evaluated against S. mutans biofilm. Biofilms formed were examined using scanning electron microscopy. Selected EOs and their selected active fractions were evaluated for their antiproliferative activity against keratinocytes and seven human tumor cell lines. MIC and MBC values obtained for EO and their active fractions showed strong antimicrobial activity. Chemical analyses mainly showed the presence of terpenes. The selected active fractions inhibited S. mutans biofilm formation (P < 0.05) did not affect glycolytic pH drop and were inactive against keratinocytes, normal cell line. In conclusion, EO showed activity at low concentrations, and their selected active fractions were also effective against biofilm formed by S. mutans and human tumor cell lines. PMID:22685486

  14. Which approach is more effective in the selection of plants with antimicrobial activity?

    PubMed

    Silva, Ana Carolina Oliveira; Santana, Elidiane Fonseca; Saraiva, Antonio Marcos; Coutinho, Felipe Neves; Castro, Ricardo Henrique Acre; Pisciottano, Maria Nelly Caetano; Amorim, Elba Lúcia Cavalcanti; Albuquerque, Ulysses Paulino

    2013-01-01

    The development of the present study was based on selections using random, direct ethnopharmacological, and indirect ethnopharmacological approaches, aiming to evaluate which method is the best for bioprospecting new antimicrobial plant drugs. A crude extract of 53 species of herbaceous plants collected in the semiarid region of Northeast Brazil was tested against 11 microorganisms. Well-agar diffusion and minimum inhibitory concentration (MIC) techniques were used. Ten extracts from direct, six from random, and three from indirect ethnopharmacological selections exhibited activities that ranged from weak to very active against the organisms tested. The strain most susceptible to the evaluated extracts was Staphylococcus aureus. The MIC analysis revealed the best result for the direct ethnopharmacological approach, considering that some species yielded extracts classified as active or moderately active (MICs between 250 and 1000 µg/mL). Furthermore, one species from this approach inhibited the growth of the three Candida strains. Thus, it was concluded that the direct ethnopharmacological approach is the most effective when selecting species for bioprospecting new plant drugs with antimicrobial activities. PMID:23878595

  15. Which Approach Is More Effective in the Selection of Plants with Antimicrobial Activity?

    PubMed Central

    Silva, Ana Carolina Oliveira; Santana, Elidiane Fonseca; Saraiva, Antonio Marcos; Coutinho, Felipe Neves; Castro, Ricardo Henrique Acre; Pisciottano, Maria Nelly Caetano; Amorim, Elba Lúcia Cavalcanti; Albuquerque, Ulysses Paulino

    2013-01-01

    The development of the present study was based on selections using random, direct ethnopharmacological, and indirect ethnopharmacological approaches, aiming to evaluate which method is the best for bioprospecting new antimicrobial plant drugs. A crude extract of 53 species of herbaceous plants collected in the semiarid region of Northeast Brazil was tested against 11 microorganisms. Well-agar diffusion and minimum inhibitory concentration (MIC) techniques were used. Ten extracts from direct, six from random, and three from indirect ethnopharmacological selections exhibited activities that ranged from weak to very active against the organisms tested. The strain most susceptible to the evaluated extracts was Staphylococcus aureus. The MIC analysis revealed the best result for the direct ethnopharmacological approach, considering that some species yielded extracts classified as active or moderately active (MICs between 250 and 1000 µg/mL). Furthermore, one species from this approach inhibited the growth of the three Candida strains. Thus, it was concluded that the direct ethnopharmacological approach is the most effective when selecting species for bioprospecting new plant drugs with antimicrobial activities. PMID:23878595

  16. Silver nanoparticles with antimicrobial activities against Streptococcus mutans and their cytotoxic effect.

    PubMed

    Pérez-Díaz, Mario Alberto; Boegli, Laura; James, Garth; Velasquillo, Cristina; Sánchez-Sánchez, Roberto; Martínez-Martínez, Rita-Elizabeth; Martínez-Castañón, Gabriel Alejandro; Martinez-Gutierrez, Fidel

    2015-10-01

    Microbial resistance represents a challenge for the scientific community to develop new bioactive compounds. The goal of this research was to evaluate the antimicrobial activity of silver nanoparticles (AgNPs) against a clinical isolate of Streptococcus mutans, antibiofilm activity against mature S. mutans biofilms and the compatibility with human fibroblasts. The antimicrobial activity of AgNPs against the planktonic clinical isolate was size and concentration dependent, with smaller AgNPs having a lower minimum inhibitory concentration. A reduction of 2.3 log in the number of colony-forming units of S. mutans was observed when biofilms grown in a CDC reactor were exposed to 100 ppm of AgNPs of 9.5±1.1 nm. However, AgNPs at high concentrations (>10 ppm) showed a cytotoxic effect upon human dermal fibroblasts. AgNPs effectively inhibited the growth of a planktonic S. mutans clinical isolate and killed established S. mutans biofilms, which suggests that AgNPs could be used for prevention and treatment of dental caries. Further research and development are necessary to translate this technology into therapeutic and preventive strategies. PMID:26117766

  17. Effect of cellulose and lignin on disintegration, antimicrobial and antioxidant properties of PLA active films.

    PubMed

    Yang, W; Fortunati, E; Dominici, F; Giovanale, G; Mazzaglia, A; Balestra, G M; Kenny, J M; Puglia, D

    2016-08-01

    This study reports the effects on antimicrobial, antioxidant, migration and disintegrability activities of ternary nanocomposite films based on poly(lactic acid) incorporating two biobased nanofillers, (cellulose nanocrystals (CNC) and lignin nanoparticles (LNP)), in two different amounts (1 and 3% wt.). Results from antimicrobial tests revealed a capacity to inhibit the Gram negative bacterial growth of Xanthomonas axonopodis pv. vesicatoria and Xanthomonas arboricola pv. pruni along the time, offering innovative opportunities against dangerous bacterial plant pathogens. LNP proved to be highly efficient in antioxidation activity, based on the disappearance of the absorption band at 517nm of the free radical, 2,2-diphenyl-1-picrylhydrazyl (DPPH) upon reduction by an antiradical compound; moreover the combination of LNP and CNC generates a synergistic positive effect in the antioxidation response of PLA ternary films. Furthermore, all the studied formulations showed a disintegrability value up to 90% after 15days of incubation in composting conditions. Migration results showed that the films can be considered suitable for application in food packaging field. PMID:27126170

  18. Antimicrobial activity against periodontopathogenic bacteria, antioxidant and cytotoxic effects of various extracts from endemic Thermopsis turcica

    PubMed Central

    Bali, Elif Burcu; Açık, Leyla; Akca, Gülçin; Sarper, Meral; Elçi, Mualla Pınar; Avcu, Ferit; Vural, Mecit

    2014-01-01

    Objective To investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan, Vural & Küçüködük against periodontopathogenic bacteria, its antioxidant activity and cytotoxic effect on various cancer cell lines. Methods In vitro antimicrobial activities of ethanol, methanol, ethyl acetate (EtAc), n-hexane and water extracts of Thermopsis turcica herb against periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans ATCC 29523 and Porphyromonas gingivalis ATCC 33277 were tested by agar well diffusion, minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Antioxidant properties of the extracts were evaluated by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity and β-carotene bleaching methods. Amounts of phenolic contents of the extracts were also analysed by using the Folin-Ciocalteu reagent. Additionally, cytotoxic activity of the extracts on androgen-insensitive prostate cancer, androgen-sensitive prostate cancer, chronic myelogenous leukemia and acute promyelocytic leukemia human cancer cell lines were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Human gingival fibroblast cells were used as a control. Results Our data showed that EtAc extract had the highest antimicrobial effect on Aggregatibacter actinomycetemcomitans (MIC: 1.562 mg/mL, MBC: 3.124 mg/mL) and Porphyromonas gingivalis (MIC: 0.781 mg/mL, MBC: 1.562 mg/mL). In antioxidant assays, EtAc extract exhibited also the highest radical scavenging activity [IC50=(30.0±0.3) µg/mL] and the highest inhibition [(74.35±0.30)%] against lineloic acide oxidation. The amount of phenolic content of it was also the highest [(162.5±1.2) µg/mg gallic acid]. In cytotoxic assay, only ethanol [IC50=(80.00±1.21) µg/mL] and EtAc extract [IC50=(70.0±0.9) µg/mL] were toxic on acute promyelocytic leukemia cells at 20-100 µg/mL (P<0.05). However, no toxic effect was observed on human gingival fibroblast cells

  19. Effect of mixed antimicrobial agents and flavors in active packaging films.

    PubMed

    Gutiérrez, Laura; Escudero, Ana; Batlle, Ramón; Nerín, Cristina

    2009-09-23

    Active packaging is an emerging food technology to improve the quality and safety of food products. Many works have been developed to study the antimicrobial activity of essential oils. Essential oils have been traditionally used as flavorings in food, so they have an important odor impact but they have as well antimicrobial properties that could be used to protect the food. Recent developments in antimicrobial active packaging showed the efficiency of essential oils versus bread and bakery products among other applications. However, one of the main problems to face is the odor and taste they could provide to the packaged food. Using some aromas to mask the odor could be a good approach. That is why the main objective of this paper is to develop an antimicrobial packaging material based on the combination of the most active compounds of essential oils (hydrocinnamaldehyde, oregano essential oil, cinnamaldehyde, thymol, and carvacrol) together with some aromas commonly used in the food industry. A study of the concentration required to get the antimicrobial properties, the organoleptic compatibility with typical aroma present in many food systems (vanilla, banana, and strawberry), and the right combination of both systems has been carried out. Antimicrobial tests of both the mentioned aromas, the main components of some essential oils, and the combination of both groups were carried out against bacteria (Enterococcus faecalis, Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Salmonella choleraesuis, Yersinia enterocolitica, Escherichia coli), yeasts (Candida albicans, Debaryomyces hansenii, Zygosaccharomyces rouxii), and molds (Botrytis cinerae, Aspergillus flavus, Penicillium roqueforti, Eurotium repens, Penicillium islandicum, Penicillium commune, Penicillium nalgiovensis). The sensory properties of the combinations were evaluated with a triangular test and classification was by an order test; the odor threshold of the aroma compounds was also

  20. Synergistic effects of guanidine-grafted CMC on enhancing antimicrobial activity and dry strength of paper.

    PubMed

    Liu, Kai; Xu, Yaoguang; Lin, Xinxing; Chen, Lihui; Huang, Liulian; Cao, Shilin; Li, Jian

    2014-09-22

    In order to improve the strength property and antimicrobial activity of paper simultaneously, we prepared a novel multifunctional agent based on carboxymethyl cellulose (CMC) by a simple two-stage method. The first stage was the oxidation of CMC to obtain the dialdehyde CMC (DCMC), and the second stage was the graft of guanidine hydrochloride (GH) onto DCMC to obtain DCMC-GH polymer. The strength property and antimicrobial activity of DCMC-GH-coated copy paper have been studied by the tensile test and inhibition zone method, respectively. The results showed that the dry strength index could increase about 20% after the paper was coated with DCMC-GH. The coating of DCMC-GH on paper also resulted in excellent antimicrobial activities against Escherichia coli and Staphylococcus aureus, and the inhibition zone became larger as the GH content grafted on DCMC increased. The novel DCMC-GH polymer would be a multifunctional coating agent for food packaging paper. PMID:24906770

  1. Stability, antimicrobial activity, and effect of nisin on the physico-chemical properties of fruit juices.

    PubMed

    de Oliveira Junior, Adelson Alves; de Araújo Couto, Hyrla Grazielle Silva; Barbosa, Ana Andréa Teixeira; Carnelossi, Marcelo Augusto Guitierrez; de Moura, Tatiana Rodrigues

    2015-10-15

    Heat processing is the most commonly used hurdle for inactivating microorganisms in fruit juices. However, this preservation method could interfere with the organoleptic characteristics of the product. Alternative methods have been proposed and bacteriocins such as nisin are potential candidates. However, the approval of bacteriocins as food additives is limited, especially in foods from vegetal origin. We aimed to verify the stability, the effect on physico-chemical properties, and the antimicrobial activity of nisin in different fruit juices. Nisin remained stable in fruit juices (cashew, soursop, peach, mango, passion fruit, orange, guava, and cupuassu) for at least 30 days at room or refrigerated temperature and did not cause any significant alterations in the physico-chemical characteristics of the juices. Besides, nisin favored the preservation of vitamin C content in juices. The antimicrobial activity of nisin was tested against Alicyclobacillus acidoterrestris, Bacillus cereus, Staphylococcus aureus and Listeria monocytogenes in cashew, soursop, peach, and mango juices. Nisin caused a 4-log reduction in viable cells of A. acidoterrestris in soursop, peach, and mango juices after 8h of incubation, and no viable cells were detected in cashew juices. After 24h of incubation in the presence of nisin, no viable cells were detected, independently of the juices. To S. aureus, at 24h of incubation in the presence of nisin, viable cells were only detected in mango juices, representing a 4-log decrease as compared with the control treatment. The number of viable cells of B. cereus at 24h of incubation in the presence of nisin represented at least a 4-log decrease compared to the control treatment. When the antimicrobial activity of nisin was tested against L. monocytogenes in cashew and soursop juices, no reduction in the viable cell number was observed compared to the control treatment after 24h of incubation. Viable cells were four and six times less than in the

  2. Antimicrobial activities of Barringtonia acutangula.

    PubMed

    Rahman, M Mukhlesur; Polfreman, David; MacGeachan, Jodie; Gray, Alexander I

    2005-06-01

    Crude extracts and VLC fractions from the stem bark of Barringtonia acutangula (L.) Gaertn (Fam. Lecythidaceae) were screened for their antimicrobial activities against two Gram-positive bacteria, two Gram-negative bacteria and two fungi using a microdilution titre assay. Among the crude extracts, petroleum ether extract showed good activity against all test organisms. The VLC fraction PE 16 was found to be very effective against Bacillus subtilis (MIC=25 microg/ml) and Aspergillus niger (MIC=12.5 microg/ml). The activities were compared to standard antibiotics-kanamycin and fluconazole. The major compound from PE16 was identified as 12, 20(29)-lupadien-3-ol by NMR spectroscopy. PMID:16114086

  3. Antimicrobial activities of squalamine mimics.

    PubMed

    Kikuchi, K; Bernard, E M; Sadownik, A; Regen, S L; Armstrong, D

    1997-07-01

    We investigated the antimicrobial properties of compounds with structural features that were designed to mimic those of squalamine, an antibiotic isolated from the stomach of the dogfish shark. The mimics, like squalamine, are sterol-polyamine conjugates. Unlike squalamine, the mimics were simple to prepare, at high yield, from readily available starting materials. Several squalamine mimics showed activity against gram-negative rods, gram-positive cocci including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and fungi. Some had little or no hemolytic activity. The hydrophobicity of the sterol backbone and the length and the cationic charge of the side chains appeared to be critical determinants of activity. One of the squalamine mimics, SM-7, was bactericidal against Escherichia coli, Pseudomonas aeruginosa, and S. aureus; its activity was decreased by divalent or monovalent cations and by bovine serum albumin. Subinhibitory concentrations of SM-7 markedly enhanced the antimicrobial activity of rifampin against gram-negative rods. These results suggest that the compounds may disrupt an outer membrane of gram-negative rods. Squalamine mimics are a new class of broad-spectrum antimicrobial agents. The antagonism of their activity by serum and albumin and their hemolytic properties may limit their use as systemic agents. The squalamine mimics, because of their potencies, broad spectra of antimicrobial activity, and potential for systemic toxicity, appear to be good candidates for development as topical antimicrobial agents. PMID:9210661

  4. Antioxidant activity and antimicrobial effect of berry phenolics--a Finnish perspective.

    PubMed

    Heinonen, Marina

    2007-06-01

    In Finland, berries are part of the traditional diet significantly contributing to the intake of flavonoids and other phenolic compounds. Compositional data on phenolic compounds in berries has been rapidly accumulating and included in the national food composition database. Among the different bioactive substances in berries, phenolic compounds including flavonoids, tannins, and phenolic acids have received considerable interest due to their effects in food and health. A great amount of in vitro evidence exists showing that berry phenolics are powerful antioxidants. However, the antioxidant effect of berry phenolics is strongly dependent on the choice of berry raw material, as the antioxidant activity differs between the different phenolic constituents, including anthocyanins, ellagitannins, and proanthocyanidins. In foods, the antioxidant effect is also influenced by the structure of food. Tannin-containing berries exhibit antimicrobial properties against pathogenic bacteria, thus offering many new applications for food industry. Much of the interest in berry phenolics has focused on cranberries and both cultivated and wild blueberries, although also other berries including black currants, cloudberries, lingonberries, and red raspberries possess promising bioactivities that may have relevance to human health. Antioxidant activity of berry phenolics, in addition to other mechanisms, may contribute to human health, but the possible relationship remains yet to be scientifically substantiated. PMID:17492800

  5. Effect of gamma irradiation on chemical composition, antimicrobial and antioxidant activities of Thymus vulgaris and Mentha pulegium essential oils

    NASA Astrophysics Data System (ADS)

    Zantar, Said; Haouzi, Rachid; Chabbi, Mohamed; Laglaoui, Amin; Mouhib, Mohammed; Mohammed Boujnah; Bakkali, Mohammed; Zerrouk, Mounir Hassani

    2015-10-01

    The effects of gamma irradiation doses (10, 20 and 30 kGy) on chemical composition, antimicrobial and antioxidant activities of Thymus vulgaris and Mentha pulegium essential oils (EOs) have been studied. The chromatographic analysis showed that the studied EOs were constituted mainly by carvacrol for T. vulgaris and pulegone for M. pulegium. Gamma irradiation on the studied doses, affects quantitatively and not qualitatively some components of the investigated oils. This effect was dose dependent. While the antioxidant activity remains stable at any dose applied for the plants studied, the antimicrobial activity increased in the irradiated samples for gram negative bacteria and did not change for gram+bacteria. This study supports that gamma irradiation employed at sterilizing doses did not compromise the biological activities of medicinal and aromatic plants.

  6. Antimicrobial activity of Securidaca longipedunculata.

    PubMed

    Ajali, U; Chukwurah, B K C

    2004-11-01

    The folk herbal uses of Securidaca longipedunculata in the treatment of diarrhea, boils, gonorrhea, and cough prompted phytochemical analyses and antimicrobial activity screening of extracts of the root. Some flavonoids isolated showed activity against many micro-organisms. These flavonoids were isolated using chromatographic methods. PMID:15636189

  7. The effect of thiol functional group incorporation into cationic helical peptides on antimicrobial activities and spectra.

    PubMed

    Wiradharma, Nikken; Khan, Majad; Yong, Lin-Kin; Hauser, Charlotte A E; Seow, See Voon; Zhang, Shuguang; Yang, Yi-Yan

    2011-12-01

    Antimicrobial peptides (AMP) have been proposed as blueprints for the development of new antimicrobial agents for the treatment of drug resistant infections. A series of synthetic AMPs capable of forming α-helical structures and containing free-sulfhydryl groups are designed in this study ((LLKK)(2)C, C(LLKK)(2)C, (LLKK)(3)C, C(LLKK)(3)C). In particular, the AMP with 2 cysteine residues at the terminal ends of the peptide and 2 repeat units of LLKK, i.e., C(LLKK)(2)C, has been demonstrated to have high selectivity towards a wide range of microbes from Gram-positive Bacillus subtilis, Gram-negative Escherichia coli, Pseudomonas aerogenosa, and yeast Candida albicans over red blood cells. At the MIC levels, this peptide does not induce significant hemolysis, and its MIC values occur at the concentration of more than 10 times of their corresponding 50% hemolysis concentrations (HC(50)). Microscopy studies suggest that this peptide kills microbial cells by inducing pores of ∼20-30 nm in size in microbial membrane on a short time scale, which further develops to grossly damaged membrane envelope on a longer time scale. Multiple treatments of microbes with this peptide at sub MIC concentration do not induce resistance, even up to passage 10. However, the same treatment with conventional antibiotics penicillin G or ciprofloxacin easily develop resistance in the treated microbes. In addition, the peptides are shown not to induce secretion of IFN-γ and TNF-α in human monocytes as compared to lipopolysaccharide, which implies additional safety aspects of the peptides to be used as both systemic and topical antimicrobial agents. Therefore, this study provides an excellent basis to develop promising antimicrobial agents that possess a broad range of antimicrobial activities with less susceptibility for development of drug resistance. PMID:21906803

  8. Antimicrobial Active Clothes Display No Adverse Effects on the Ecological Balance of the Healthy Human Skin Microflora

    PubMed Central

    Hoefer, Dirk; Hammer, Timo R.

    2011-01-01

    The progressive public use of antimicrobial clothes has raised issues concerning skin health. A placebo-controlled side-to-side study was run with antimicrobial clothes versus fabrics of similar structure but minus the antimicrobial activity, to evaluate possible adverse effects on the healthy skin microflora. Sixty volunteers were enrolled. Each participant received a set of form-fitting T-shirts constructed in 2 halves: an antibacterial half, displaying activities of 3–5 log-step reductions due to silver-finishes or silver-loaded fibres and a nonantibacterial control side. The microflora of the scapular skin was analyzed weekly for opportunistic and pathogenic microorganisms over six weeks. The antibacterial halves did not disturb the microflora in number or composition, whereas a silver-containing deodorant displayed a short-term disturbance. Furthermore, parameters of skin morphology and function (TEWL, pH, moisture) did not show any significant shifts. In summary, antimicrobial clothes did not show adverse effects on the ecological balance of the healthy skin microflora. PMID:22363849

  9. High Antimicrobial Effectiveness with Low Hemolytic and Cytotoxic Activity for PEG/Quaternary Copolyoxetanes

    PubMed Central

    2015-01-01

    The alkyl chain length of quaternary ammonium/PEG copolyoxetanes has been varied to discern effects on solution antimicrobial efficacy, hemolytic activity and cytotoxicity. Monomers 3-((4-bromobutoxy)methyl)-3-methyloxetane (BBOx) and 3-((2-(2-methoxyethoxy)ethoxy)methyl)-3-methyloxetane (ME2Ox) were used to prepare precursor P[(BBOx)(ME2Ox)-50:50–4 kDa] copolyoxetane via cationic ring opening polymerization. The 1:1 copolymer composition and Mn (4 kDa) were confirmed by 1H NMR spectroscopy. After C–Br substitution by a series of tertiary amines, ionic liquid Cx-50 copolyoxetanes were obtained, where 50 is the mole percent of quaternary repeat units and “x” is quaternary alkyl chain length (2, 6, 8, 10, 12, 14, or 16 carbons). Modulated differential scanning calorimetry (MDSC) studies showed Tgs between −40 and −60 °C and melting endotherms for C14–50 and C16–50. Minimum inhibitory concentrations (MIC) were determined for Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. A systematic dependence of MIC on alkyl chain length was found. The most effective antimicrobials were in the C6–50 to C12–50 range. C8–50 had better overall performance with MICs of 4 μg/mL, E. coli; 2 μg/mL, S. aureus; and 24 μg/mL, P. aeruginosa. At 5 × MIC, C8–50 effected >99% kill in 1 h against S. aureus, E. coli, and P. aeruginosa challenges of 108 cfu/mL; log reductions (1 h) were 7, 3, and 5, respectively. To provide additional insight into polycation interactions with bacterial membranes, a geometric model based on the dimensions of E. coli is described that provides an estimate of the maximum number of polycations that can chemisorb. Chain dimensions were estimated for polycation C8–50 with a molecular weight of 5 kDa. Considering the approximations for polycation chemisorption (PCC), it is surprising that a calculation based on geometric considerations gives a C8–50 concentration within a factor of 2 of the MIC, 4.0 (±1.2) μg/mL for

  10. High antimicrobial effectiveness with low hemolytic and cytotoxic activity for PEG/quaternary copolyoxetanes.

    PubMed

    King, Allison; Chakrabarty, Souvik; Zhang, Wei; Zeng, Xiaomei; Ohman, Dennis E; Wood, Lynn F; Abraham, Sheena; Rao, Raj; Wynne, Kenneth J

    2014-02-10

    The alkyl chain length of quaternary ammonium/PEG copolyoxetanes has been varied to discern effects on solution antimicrobial efficacy, hemolytic activity and cytotoxicity. Monomers 3-((4-bromobutoxy)methyl)-3-methyloxetane (BBOx) and 3-((2-(2-methoxyethoxy)ethoxy)methyl)-3-methyloxetane (ME2Ox) were used to prepare precursor P[(BBOx)(ME2Ox)-50:50-4 kDa] copolyoxetane via cationic ring opening polymerization. The 1:1 copolymer composition and Mn (4 kDa) were confirmed by (1)H NMR spectroscopy. After C-Br substitution by a series of tertiary amines, ionic liquid Cx-50 copolyoxetanes were obtained, where 50 is the mole percent of quaternary repeat units and "x" is quaternary alkyl chain length (2, 6, 8, 10, 12, 14, or 16 carbons). Modulated differential scanning calorimetry (MDSC) studies showed Tgs between -40 and -60 °C and melting endotherms for C14-50 and C16-50. Minimum inhibitory concentrations (MIC) were determined for Escherichia coli , Staphylococcus aureus , and Pseudomonas aeruginosa . A systematic dependence of MIC on alkyl chain length was found. The most effective antimicrobials were in the C6-50 to C12-50 range. C8-50 had better overall performance with MICs of 4 μg/mL, E. coli ; 2 μg/mL, S. aureus ; and 24 μg/mL, P. aeruginosa . At 5 × MIC, C8-50 effected >99% kill in 1 h against S. aureus , E. coli , and P. aeruginosa challenges of 10(8) cfu/mL; log reductions (1 h) were 7, 3, and 5, respectively. To provide additional insight into polycation interactions with bacterial membranes, a geometric model based on the dimensions of E. coli is described that provides an estimate of the maximum number of polycations that can chemisorb. Chain dimensions were estimated for polycation C8-50 with a molecular weight of 5 kDa. Considering the approximations for polycation chemisorption (PCC), it is surprising that a calculation based on geometric considerations gives a C8-50 concentration within a factor of 2 of the MIC, 4.0 (±1.2) μg/mL for E. coli . Cx-50

  11. Effect of addition of 2% chlorhexidine or 10% doxycycline on antimicrobial activity of biodentine

    PubMed Central

    Nikhil, Vineeta; Madan, Molly; Agarwal, Charu; Suri, Navleen

    2014-01-01

    Aim: The purpose of this in vitro study was to determine whether the addition of 2% chlorhexidine gluconate or 10% doxycycline would enhance the antimicrobial activity of Biodentine against Staphylococcus aureus (ATCC-25923), Enterococcus faecalis (ATCC-29212), Candida albicans (ATCC-90028), and Streptococcus mutans (MTCC-497). Materials and Methods: Three wells of 4 mm diameter and 4 mm depth on each plate were prepared on the agar medium with standardized suspensions of each microorganism. Biodentine powder mixed with 2% chlorhexidine (0.06 g) or 10% doxycycline (0.30 g) in its liquid or liquid alone was placed to fill each well. Plates were incubated at 37°C as required for microbial growth. A blinded, independent observer measured zones of inhibition. The data were analyzed using independent “t” test to compare the differences among the three cement preparations for different micro-organisms. Results: All Biodentine samples inhibited microbial growth. The highest mean diameters of zone of inhibition for all the micro-organisms were found around Biodentine/chlorhexidine (13.417) followed by Biodentine alone (12.236) and Biodentine/doxycycline (11.25). Conclusion: In conclusion, adding 2% chlorhexidine gluconate in liquid of Biodentine enhanced the antimicrobial activity of Biodentine against all the tested micro-organisms except Candida albicans, while addition of 10% doxycycline decreased the antimicrobial activity of Biodentine. The differences were significant statistically (P < 0.05). PMID:24944453

  12. Effects of allspice, cinnamon, and clove bud essential oils in edible apple films on physical properties and antimicrobial activities.

    PubMed

    Du, W-X; Olsen, C W; Avena-Bustillos, R J; McHugh, T H; Levin, C E; Friedman, Mendel

    2009-09-01

    Essential oils (EOs) derived from plants are rich sources of volatile terpenoids and phenolic compounds. Such compounds have the potential to inactivate pathogenic bacteria on contact and in the vapor phase. Edible films made from fruits or vegetables containing EOs can be used commercially to protect food against contamination by pathogenic bacteria. EOs from cinnamon, allspice, and clove bud plants are compatible with the sensory characteristics of apple-based edible films. These films could extend product shelf life and reduce risk of pathogen growth on food surfaces. This study evaluated physical properties (water vapor permeability, color, tensile properties) and antimicrobial activities against Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes of allspice, cinnamon, and clove bud oils in apple puree film-forming solutions formulated into edible films at 0.5% to 3% (w/w) concentrations. Antimicrobial activities were determined by 2 independent methods: overlay of the film on top of the bacteria and vapor phase diffusion of the antimicrobial from the film to the bacteria. The antimicrobial activities against the 3 pathogens were in the following order: cinnamon oil > clove bud oil > allspice oil. The antimicrobial films were more effective against L. monocytogenes than against the S. enterica. The oils reduced the viscosity of the apple solutions and increased elongation and darkened the colors of the films. They did not affect water vapor permeability. The results show that apple-based films with allspice, cinnamon, or clove bud oils were active against 3 foodborne pathogens by both direct contact with the bacteria and indirectly by vapors emanating from the films. PMID:19895483

  13. Regulation of IDO activity by oxygen supply: inhibitory effects on antimicrobial and immunoregulatory functions.

    PubMed

    Schmidt, Silvia K; Ebel, Sebastian; Keil, Eric; Woite, Claudia; Ernst, Joachim F; Benzin, Anika E; Rupp, Jan; Däubener, Walter

    2013-01-01

    Tryptophan is an essential amino acid for human beings as well as for some microorganisms. In human cells the interferon-γ (IFN-γ) inducible enzyme indoleamine 2,3-dioxygenase (IDO) reduces local tryptophan levels and is therefore able to mediate broad-spectrum effector functions: IDO activity restricts the growth of various clinically relevant pathogens such as bacteria, parasites and viruses. On the other hand, it has been observed that IDO has immunoregulatory functions as it efficiently controls the activation and survival of T-cells. Although these important effects have been analysed in much detail, they have been observed in vitro using cells cultured in the presence of 20% O₂ (normoxia). Such high oxygen concentrations are not present in vivo especially within infected and inflamed tissues. We therefore analysed IDO-mediated effects under lower oxygen concentrations in vitro and observed that the function of IDO is substantially impaired in tumour cells as well as in native cells. Hypoxia led to reduced IDO expression and as a result to reduced production of kynurenine, the downstream product of tryptophan degradation. Consequently, effector functions of IDO were abrogated under hypoxic conditions: in different human cell lines such as tumour cells (glioblastoma, HeLa) but also in native cells (human foreskin fibroblasts; HFF) IDO lost the capacity to inhibit the growth of bacteria (Staphylococcus aureus), parasites (Toxoplasma gondii) or viruses (herpes simplex virus type 1). Additionally, IDO could no longer efficiently control the proliferation of T-cells that have been co-cultured with IDO expressing HFF cells in vitro. In conclusion, the potent antimicrobial as well as immunoregulatory functions of IDO were substantially impaired under hypoxic conditions that pathophysiologically occurs in vivo. PMID:23675474

  14. Regulation of IDO Activity by Oxygen Supply: Inhibitory Effects on Antimicrobial and Immunoregulatory Functions

    PubMed Central

    Keil, Eric; Woite, Claudia; Ernst, Joachim F.; Benzin, Anika E.; Rupp, Jan; Däubener, Walter

    2013-01-01

    Tryptophan is an essential amino acid for human beings as well as for some microorganisms. In human cells the interferon-γ (IFN-γ) inducible enzyme indoleamine 2,3-dioxygenase (IDO) reduces local tryptophan levels and is therefore able to mediate broad-spectrum effector functions: IDO activity restricts the growth of various clinically relevant pathogens such as bacteria, parasites and viruses. On the other hand, it has been observed that IDO has immunoregulatory functions as it efficiently controls the activation and survival of T-cells. Although these important effects have been analysed in much detail, they have been observed in vitro using cells cultured in the presence of 20% O2 (normoxia). Such high oxygen concentrations are not present in vivo especially within infected and inflamed tissues. We therefore analysed IDO-mediated effects under lower oxygen concentrations in vitro and observed that the function of IDO is substantially impaired in tumour cells as well as in native cells. Hypoxia led to reduced IDO expression and as a result to reduced production of kynurenine, the downstream product of tryptophan degradation. Consequently, effector functions of IDO were abrogated under hypoxic conditions: in different human cell lines such as tumour cells (glioblastoma, HeLa) but also in native cells (human foreskin fibroblasts; HFF) IDO lost the capacity to inhibit the growth of bacteria (Staphylococcus aureus), parasites (Toxoplasma gondii) or viruses (herpes simplex virus type 1). Additionally, IDO could no longer efficiently control the proliferation of T-cells that have been co-cultured with IDO expressing HFF cells in vitro. In conclusion, the potent antimicrobial as well as immunoregulatory functions of IDO were substantially impaired under hypoxic conditions that pathophysiologically occurs in vivo. PMID:23675474

  15. Antimicrobial Activity of Lactic Acid Bacteria in Dairy Products and Gut: Effect on Pathogens

    PubMed Central

    Rodríguez, Eva; Landete, José María

    2015-01-01

    The food industry seeks alternatives to satisfy consumer demands of safe foods with a long shelf-life able to maintain the nutritional and organoleptic quality. The application of antimicrobial compounds-producing protective cultures may provide an additional parameter of processing in order to improve the safety and ensure food quality, keeping or enhancing its sensorial characteristics. In addition, strong evidences suggest that certain probiotic strains can confer resistance against infection with enteric pathogens. Several mechanisms have been proposed to support this phenomenon, including antimicrobial compounds secreted by the probiotics, competitive exclusion, or stimulation of the immune system. Recent research has increasingly demonstrated the role of antimicrobial compounds as protective mechanism against intestinal pathogens and therefore certain strains could have an effect on both the food and the gut. In this aspect, the effects of the combination of different strains keep unknown. The development of multistrain probiotic dairy products with good technological properties and with improved characteristics to those shown by the individual strains, able to act not only as protective cultures in foods, but also as probiotics able to exert a protective action against infections, has gained increased interest. PMID:25861634

  16. Antimicrobial activity of lactic acid bacteria in dairy products and gut: effect on pathogens.

    PubMed

    Arqués, Juan L; Rodríguez, Eva; Langa, Susana; Landete, José María; Medina, Margarita

    2015-01-01

    The food industry seeks alternatives to satisfy consumer demands of safe foods with a long shelf-life able to maintain the nutritional and organoleptic quality. The application of antimicrobial compounds-producing protective cultures may provide an additional parameter of processing in order to improve the safety and ensure food quality, keeping or enhancing its sensorial characteristics. In addition, strong evidences suggest that certain probiotic strains can confer resistance against infection with enteric pathogens. Several mechanisms have been proposed to support this phenomenon, including antimicrobial compounds secreted by the probiotics, competitive exclusion, or stimulation of the immune system. Recent research has increasingly demonstrated the role of antimicrobial compounds as protective mechanism against intestinal pathogens and therefore certain strains could have an effect on both the food and the gut. In this aspect, the effects of the combination of different strains keep unknown. The development of multistrain probiotic dairy products with good technological properties and with improved characteristics to those shown by the individual strains, able to act not only as protective cultures in foods, but also as probiotics able to exert a protective action against infections, has gained increased interest. PMID:25861634

  17. Antimicrobial activity against oral pathogens and immunomodulatory effects and toxicity of geopropolis produced by the stingless bee Melipona fasciculata Smith

    PubMed Central

    2011-01-01

    Background Native bees of the tribe Meliponini produce a distinct kind of propolis called geopropolis. Although many pharmacological activities of propolis have already been demonstrated, little is known about geopropolis, particularly regarding its antimicrobial activity against oral pathogens. The present study aimed at investigating the antimicrobial activity of M. fasciculata geopropolis against oral pathogens, its effects on S. mutans biofilms, and the chemical contents of the extracts. A gel prepared with a geopropolis extract was also analyzed for its activity on S. mutans and its immunotoxicological potential. Methods Antimicrobial activities of three hydroalcoholic extracts (HAEs) of geopropolis, and hexane and chloroform fractions of one extract, were evaluated using the agar diffusion method and the broth dilution technique. Ethanol (70%, v/v) and chlorhexidine (0.12%, w/w) were used as negative and positive controls, respectively. Total phenol and flavonoid concentrations were assayed by spectrophotometry. Immunotoxicity was evaluated in mice by topical application in the oral cavity followed by quantification of biochemical and immunological parameters, and macro-microscopic analysis of animal organs. Results Two extracts, HAE-2 and HAE-3, showed inhibition zones ranging from 9 to 13 mm in diameter for S. mutans and C. albicans, but presented no activity against L. acidophilus. The MBCs for HAE-2 and HAE-3 against S. mutans were 6.25 mg/mL and 12.5 mg/mL, respectively. HAE-2 was fractionated, and its chloroform fraction had an MBC of 14.57 mg/mL. HAE-2 also exhibited bactericidal effects on S. mutans biofilms after 3 h of treatment. Significant differences (p < 0.05) in total phenol and flavonoid concentrations were observed among the samples. Signs toxic effects were not observed after application of the geopropolis-based gel, but an increase in the production of IL-4 and IL-10, anti-inflammatory cytokines, was detected. Conclusions In summary

  18. Antimicrobial Activity of Commercial Nanoparticles

    NASA Astrophysics Data System (ADS)

    Gajjar, Priyanka; Pettee, Brian; Britt, David W.; Huang, Wenjie; Johnson, William P.; Anderson, Anne J.

    2009-07-01

    Engineered nanoparticles are finding increased use in applications ranging from biosensors to prophylactic antimicrobials embedded in socks. The release of heavy metal-containing nanoparticles (NP) into the environment may be harmful to the efficacy of beneficial microbes that function in element cycling, pollutant degradation, and plant growth. Antimicrobial activity of commercial NP of Ag, CuO, and ZnO is demonstrated here against the beneficial soil microbe, Pseudomonas putida KT2440, which was modified to serve as a bioluminescent sentinel organism. "As manufactured" preparations of nano- Ag, -CuO, and -ZnO caused rapid, dose dependent loss of light output in the biosensor. Bulk equivalents of these products showed no inhibitory activity, indicating that particle size was determinant in activity.

  19. Antimicrobial Activity of Carbon-Based Nanoparticles

    PubMed Central

    Maleki Dizaj, Solmaz; Mennati, Afsaneh; Jafari, Samira; Khezri, Khadejeh; Adibkia, Khosro

    2015-01-01

    Due to the vast and inappropriate use of the antibiotics, microorganisms have begun to develop resistance to the commonly used antimicrobial agents. So therefore, development of the new and effective antimicrobial agents seems to be necessary. According to some recent reports, carbon-based nanomaterials such as fullerenes, carbon nanotubes (CNTs) (especially single-walled carbon nanotubes (SWCNTs)) and graphene oxide (GO) nanoparticles show potent antimicrobial properties. In present review, we have briefly summarized the antimicrobial activity of carbon-based nanoparticles together with their mechanism of action. Reviewed literature show that the size of carbon nanoparticles plays an important role in the inactivation of the microorganisms. As major mechanism, direct contact of microorganisms with carbon nanostructures seriously affects their cellular membrane integrity, metabolic processes and morphology. The antimicrobial activity of carbon-based nanostructures may interestingly be investigated in the near future owing to their high surface/volume ratio, large inner volume and other unique chemical and physical properties. In addition, application of functionalized carbon nanomaterials as carriers for the ordinary antibiotics possibly will decrease the associated resistance, enhance their bioavailability and provide their targeted delivery. PMID:25789215

  20. [Antimicrobial activity exerted by sodium dichloroisocyanurate].

    PubMed

    D'Auria, F D; Simonetti, G; Strippoli, V

    1989-01-01

    Sodium dichloroisocyanurate is a chlorinated cleaner. It was used for swimming pool sanitation and for the sterilisation of linen. Not recently ago sodium dichloroisocyanurate has substituted hypochlorite for the sterilisation of infant feeding bottles and teats. Sodium dichloroisocyanurate is soluble in water; this condition causes the hydrolysis of sodium dichloroisocyanurate in hypochlorous acid, that is the active agent, isocyanurate and isocyanurate chlorine. These compounds form a chlorine protein that carry out microbicidal activity. In a toxicology study has been shown that no severe changes in the normal metabolic function occurred, furthermore sodium dichloroisocyanurate has not shown teratogenic effects at the concentration of 200 mg/kg. The antimicrobial activity of sodium dichloroisocyanurate was evaluated against Gram negative bacteria such as E. coli or Salmonella typhimurium and against some fungi. This study illustrates a rapid antimicrobial activity using concentrations. Our study concentrated on the antimicrobial activity of sodium dichloroisocyanurate in some experimental conditions. We tested 66 strains of fungi, 28 Gram positive bacteria and 29 Gram negative bacteria. We also evaluated the antimicrobial activity of sodium dichloroisocyanurate against protozoa such as Trichomonas vaginalis. The antimicrobial activity was evaluated in cultural conditions and non cultural conditions; in these experiments we observed similar action in both the commercial product and pure substance. In cultural conditions sodium dichloroisocyanurate shows a good activity against fungi and bacteria, moreover it can be observed that the serum didn't interfere with its activity. In a non cultural condition the Candida was killed rapidly by the sodium dichloroisocyanurate but this activity is influenced by the growth phase of the yeast. Against mycelial form such as Penicillium and Aspergillus the sodium dichloroisocyanurate needs a longer contact time than yeast form

  1. The antimicrobial efficiency of silver activated sorbents

    NASA Astrophysics Data System (ADS)

    Đolić, Maja B.; Rajaković-Ognjanović, Vladana N.; Štrbac, Svetlana B.; Rakočević, Zlatko Lj.; Veljović, Đorđe N.; Dimitrijević, Suzana I.; Rajaković, Ljubinka V.

    2015-12-01

    This study is focused on the surface modifications of the materials that are used for antimicrobial water treatment. Sorbents of different origin were activated by Ag+-ions. The selection of the most appropriate materials and the most effective activation agents was done according to the results of the sorption and desorption kinetic studies. Sorption capacities of selected sorbents: granulated activated carbon (GAC), zeolite (Z), and titanium dioxide (T), activated by Ag+-ions were following: 42.06, 13.51 and 17.53 mg/g, respectively. The antimicrobial activity of Ag/Z, Ag/GAC and Ag/T sorbents were tested against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus and yeast C. albicans. After 15 min of exposure period, the highest cell removal was obtained using Ag/Z against S. aureus and E. coli, 98.8 and 93.5%, respectively. Yeast cell inactivation was unsatisfactory for all three activated sorbents. The antimicrobial pathway of the activated sorbents has been examined by two separate tests - Ag+-ions desorbed from the activated surface to the aqueous phase and microbial cell removal caused by the Ag+-ions from the solid phase (activated surface sites). The results indicated that disinfection process significantly depended on the microbial-activated sites interactions on the modified surface. The chemical state of the activating agent had crucial impact to the inhibition rate. The characterization of the native and modified sorbents was performed by X-ray diffraction technique, X-ray photoelectron spectroscopy and scanning electron microscope. The concentration of adsorbed and released ions was determined by inductively coupled plasma optical emission spectroscopy and mass spectrometry. The antimicrobial efficiency of activated sorbents was related not only to the concentration of the activating agent, but moreover on the surface characteristics of the material, which affects the distribution and the accessibility of the activating agent.

  2. Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin.

    PubMed

    Gong, Shi-Qiang; Epasinghe, D Jeevanie; Zhou, Bin; Niu, Li-Na; Kimmerling, Kirk A; Rueggeberg, Frederick A; Yiu, Cynthia K Y; Mao, Jing; Pashley, David H; Tay, Franklin R

    2013-06-01

    Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol-gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly(methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances. PMID:23485857

  3. Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin

    PubMed Central

    Gong, Shi-qiang; Epasinghe, D. Jeevanie; Zhou, Bin; Niu, Li-na; Kimmerling, Kirk A.; Rueggeberg, Frederick A.; Yiu, Cynthia K.Y.; Mao, Jing; Pashley, David H.; Tay, Franklin R.

    2013-01-01

    Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol–gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly (methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3 month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4 wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances. PMID:23485857

  4. Size and Aging Effects on Antimicrobial Efficiency of Silver Nanoparticles Coated on Polyamide Fabrics Activated by Atmospheric DBD Plasma.

    PubMed

    Zille, Andrea; Fernandes, Margarida M; Francesko, Antonio; Tzanov, Tzanko; Fernandes, Marta; Oliveira, Fernando R; Almeida, Luís; Amorim, Teresa; Carneiro, Noémia; Esteves, Maria F; Souto, António P

    2015-07-01

    This work studies the surface characteristics, antimicrobial activity, and aging effect of plasma-pretreated polyamide 6,6 (PA66) fabrics coated with silver nanoparticles (AgNPs), aiming to identify the optimum size of nanosilver exhibiting antibacterial properties suitable for the manufacture of hospital textiles. The release of bactericidal Ag(+) ions from a 10, 20, 40, 60, and 100 nm AgNPs-coated PA66 surface was a function of the particles' size, number, and aging. Plasma pretreatment promoted both ionic and covalent interactions between AgNPs and the formed oxygen species on the fibers, favoring the deposition of smaller-diameter AgNPs that consequently showed better immediate and durable antimicrobial effects against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. Surprisingly, after 30 days of aging, a comparable bacterial growth inhibition was achieved for all of the fibers treated with AgNPs <100 nm in size. The Ag(+) in the coatings also favored the electrostatic stabilization of the plasma-induced functional groups on the PA66 surface, thereby retarding the aging process. At the same time, the size-related ratio (Ag(+)/Ag(0)) of the AgNPs between 40 and 60 nm allowed for the controlled release of Ag(+) rather than bulk silver. Overall, the results suggest that instead of reducing the size of the AgNPs, which is associated with higher toxicity, similar long-term effects can be achieved with larger NPs (40-60 nm), even in lower concentrations. Because the antimicrobial efficiency of AgNPs larger than 30 nm is mainly ruled by the release of Ag(+) over time and not by the size and number of the AgNPs, this parameter is crucial for the development of efficient antimicrobial coatings on plasma-treated surfaces and contributes to the safety and durability of clothing used in clinical settings. PMID:26057400

  5. Leaves Antimicrobial Activity of Glycyrrhiza glabra L.

    PubMed

    Irani, Mahboubeh; Sarmadi, Marziyeh; Bernard, Françoise; Ebrahimi Pour, Gholam Hossein; Shaker Bazarnov, Hossein

    2010-01-01

    Licorice (Glycyrrhiza glabra L.) is an important medicinal plant. In this study, the antimicrobial activities of ethanolic and aqueous extracts from licorice leaves were studied compared to root extracts activities. Bacillus subtilis, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli, and Candida albicans were used as test organisms. Antimicrobial activity was tested by paper disc agar diffusion and serial dilution methods in order to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The root and leave extracts showed activity against Candida albicans, and tested gram-positive bacteria in a dose dependent manner. The ethanolic extract of the leaves was the most active extract against gram-positive bacteria. Its effectiveness against strains provides hope that it can serve as an alternative therapeutic agent. PMID:24381608

  6. Magnesium Based Materials and their Antimicrobial Activity

    NASA Astrophysics Data System (ADS)

    Robinson, Duane Allan

    The overall goals of this body of work were to characterize the antimicrobial properties of magnesium (Mg) metal and nano-magnesium oxide (nMgO) in vitro, to evaluate the in vitro cytotoxicity of Mg metal, and to incorporate MgO nanoparticles into a polymeric implant coating and evaluate its in vitro antimicrobial properties. In the course of this work it was found that Mg metal, Mg-mesh, and nMgO have in vitro antimicrobial properties that are similar to a bactericidal antibiotic. For Mg metal, the mechanism of this activity appears to be related to an increase in pH (i.e. a more alkaline environment) and not an increase in Mg2+. Given that Mg-mesh is a Mg metal powder, the assumption is that it has the same mechanism of activity as Mg metal. The mechanism of activity for nMgO remains to be elucidated and may be related to a combination of interaction of the nanoparticles with the bacteria and the alkaline pH. It was further demonstrated that supernatants from suspensions of Mg-mesh and nMgO had the same antimicrobial effect as was noted when the particles were used. The supernatant from Mg-mesh and nMgO was also noted to prevent biofilm formation for two Staphylococcus strains. Finally, poly-epsilon-caprolactone (PCL) composites of Mg-mesh (PCL+Mg-mesh) and nMgO (PCL+nMgO) were produced. Coatings applied to screws inhibited growth of Escherichia coli and Pseudomonas aeruginosa and in thin disc format inhibited the growth of Staphylococcus aureus in addition to the E. coli and P. aeruginosa. Pure Mg metal was noted to have some cytotoxic effect on murine fibroblast and osteoblast cell lines, although this effect needs to be characterized further. To address the need for an in vivo model for evaluating implant associated infections, a new closed fracture osteomyelitis model in the femur of the rat was developed. Magnesium, a readily available and inexpensive metal was shown to have antimicrobial properties that appear to be related to its corrosion products and

  7. Antimicrobial activity of benzylisoquinoline alkaloids.

    PubMed

    Villar, A; Mares, M; Rios, J L; Canton, E; Gobernado, M

    1987-04-01

    The antimicrobial in vitro activity of 14 benzylisoquinoline alkaloids was investigated by agar diffusion and agar dilution methods against several genera of microorganisms that included Streptococcus, Staphylococcus, Bacillus, Lysteria, Escherichia, Salmonella, Klebsiella, Pseudomonas, Enterobacter, Serratia, Shigella, Mycobacterium and Candida. Anolobine was the most active compound against grampositive bacteria with MIC90 between 12 and 50 mg/l; less active were anonaine, lysicamine and liriodenine. All the alkaloids of the noraporphine and oxoaporphine groups, with the exception of isopiline, showed activity against Mycobacterium phlei (MIC 6-25 mg/l). Candida albicans ATCC26555 was inhibited by anonaine, nornantenine and xylopine (MIC 3-12 mg/l). None of the alkaloids tested had a significant activity against gramnegative rods. The action against susceptible microorganisms was bactericidal. PMID:3615557

  8. Effect of gamma irradiation on the antimicrobial and free radical scavenging activities of Glycyrrhiza glabra root

    NASA Astrophysics Data System (ADS)

    Fatima Khattak, Khanzadi; James Simpson, Thomas

    2010-04-01

    The efficacy of gamma irradiation as a method of decontamination for food and herbal materials is well established. In the present study, Glycyrrhiza glabra roots were irradiated at doses 5, 10, 15, 20 and 25 kGy in a cobalt-60 irradiator. The irradiated and un-irradiated control samples were evaluated for phenolic contents, antimicrobial activities and DPPH scavenging properties. The result of the present study showed that radiation treatment up to 20 kGy does not affect the antifungal and antibacterial activity of the plant. While sample irradiated at 25 kGy does showed changes in the antibacterial activity against some selected pathogens. No significant differences in the phenolic contents were observed for control and samples irradiated at 5, 10 and 15 kGy radiation doses. However, phenolic contents increased in samples treated with 20 and 25 kGy doses. The DPPH scavenging activity significantly ( p<0.05) increased in all irradiated samples of the plant.

  9. IN-VITRO ANTIMICROBIAL ACTIVITY OF BRONCHOSOL.

    PubMed

    Witkowska-Banaszczak, Ewa; Michalak, Anna; Kędzia, Anna

    2015-01-01

    Bronchosol is a traditional medicinal product in the form of syrup used in cough and impeded expectoration. The active ingredients that it contains include extracts from the herb of thyme, the root of primrose and thymol. It is recommended in disorders of the respiratory tract when expectoration is impeded and secretion of liquid mucus in bronchi is insufficient. Antimicrobial activity of the components of Bronchosol, especially thyme and thymol, has frequently been reported in the literature. To date, there have not been any studies to confirm such activity of Bronchosol, though. The results of our research are the first one to point to the great activity of Bronchosol against microorganisms causing infections of the respiratory tract. It has been demonstrated that this product displayed antimicrobial activity against reference strains as well as strains of anaerobic and aerobic bacteria and fungi isolated from patients. The confirmation of the antimicrobial activity of Bronchosol provides an explanation of its effectiveness in the therapy of the respiratory tract infections. PMID:26642688

  10. Hybrid surfactants decorated with copper ions: aggregation behavior, antimicrobial activity and anti-proliferative effect.

    PubMed

    Kaur, Gurpreet; Kumar, Sandeep; Dilbaghi, Neeraj; Bhanjana, Gaurav; Guru, Santosh Kumar; Bhushan, Shashi; Jaglan, Sundeep; Hassan, P A; Aswal, V K

    2016-09-14

    In the present study, the emphasis is laid on the self aggregation behavior of copper based inorganic-organic hybrids in aqueous media. The two complexes, cationic hexadecyl pyridinium trichloro cuprate (1 : 1), [Cp](+)[CuCl3](-), and bishexadecylpyridinium tetrachloro cuprate (2 : 1), [Cp2](2+)[CuCl4](2-), were synthesized using the ligand insertion method. The complexes were characterized using elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and thermogravimetric analysis. The copper complexes were found to be thermally stable, and in the solid state, they possessed the perovskite arrangement with [Cp2](2+)[CuCl4](2-) exhibiting superior stability and crystallinity. The self aggregation behavior of the prepared complexes was analyzed in solution phase (in aqueous medium) using surface tension, conductivity, XRD and small angle neutron scattering (SANS). The results show that the presence of copper as a co-ion in both the stoichiometries results in lower critical micellization concentrations than their precursor. Micellization was thermodynamically spontaneous and micelles formed were ellipsoidal in shape and underwent a prolate ellipsoidal growth with an increase in the concentration of metallosurfactant, as estimated from the SANS. Furthermore, these metallosurfactants were investigated for biocompatibility (using hemolytic assay), antimicrobial activity (fungus and bacteria) and cytotoxicity using human cancerous cells. The hemolysis activity was found to depend on the aggregated state of the metallosurfactants, displaying the highest activity in the monomeric state, and the minimum for post micellar concentrations. The surfactants were found to enhance the antibacterial activity by twofold or more, with the addition of metal in both the stoichiometries. On the contrary, for anticancer and antifungal activities, barely any regular trend or generalization could be obtained

  11. Antimicrobial activity of preparation Bioaron C.

    PubMed

    Gawron-Gzella, Anne; Michalak, Anna; Kędzia, Anna

    2014-01-01

    The antimicrobial activity of sirupus Bioaron C, a preparation, whose main ingredient is an extract from the leaves of Aloe arborescens, was tested against different microorganisms isolated from patients with upper respiratory tract infections. The experiments were performed on 40 strains: 20 strains of anaerobic bacteria, 13 strains of aerobic bacteria and 7 strains of yeast-like fungi from the genus Candida and on 18 reference strains (ATCC). The antimicrobial activity of Bioaron C (MBC and MFC) was determined at undiluted concentration. Bioaron C proved to be very effective against the microorganisms causing infections. At the concentration recommended by the producer, the preparation showed biocidal activity (MBC, MFC) against the strains of the pathogenic microorganisms, which cause respiratory infections most frequently, including, among others, Peptostreptococcus anaerobius, Parvimonas micra, Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus anginosus, Haemophilus influenzae, Moraxella catarrhalis, Pseudomonas aeruginosa and Candida albicans, already after 15 min. The MIC of Bioaron C against most of the tested microorganisms was 5 to 100 times lower than the usually applied concentration. The great antimicrobial activity means that the preparation may be used in the prevention and treatment of infections of the upper respiratory tract. Bioaron C may be an alternative or complement to classical therapy, especially in children. PMID:25362808

  12. Antimicrobial activity of honokiol and magnolol isolated from Magnolia officinalis.

    PubMed

    Ho, K Y; Tsai, C C; Chen, C P; Huang, J S; Lin, C C

    2001-03-01

    The antimicrobial activity of honokiol and magnolol, the main constituents of Magnolia officinalis was investigated. The antimicrobial activity was assayed by the agar dilution method using brain heart infusion medium and the minimum inhibitory concentration (MIC) were determined for each compound using a twofold serial dilution assay. The results showed that honokiol and magnolol have a marked antimicrobial effect (MIC = 25 microg/mL) against Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Micrococcus luteus and Bacillus subtilis, but did not show antimicrobial activity (MIC > or = 100 microg/mL) for Shigella flexneii, Staphylococcus epidermidis, Enterobacter aerogenes, Proteus vulgaris, Escherichia coli and Pseudomonas aeruginosa. Our results indicate that honokiol and magnolol, although less potent than tetracycline, show a significant antimicrobial activity for periodontal pathogens. Hence we suggest that honokiol and magnolol might have the potential to be an adjunct in the treatment of periodontitis. PMID:11268114

  13. Synthesis and antimicrobial activity of squalamine analogue.

    PubMed

    Kim, H S; Choi, B S; Kwon, K C; Lee, S O; Kwak, H J; Lee, C H

    2000-08-01

    Synthesis and antimicrobial activity of squalamine analogue 2 are reported. The synthesis of 2 was accomplished from bisnoralcohol 3. The spermidine moiety was introduced via reductive amination of an appropriately functionalized 3beta-aminosterol with spermidinyl aldehyde 17 utilizing sodium triacetoxyborohydride as the reducing agent. Compound 2 shows weaker antimicrobial activity than squalamine. PMID:11003150

  14. A Novel Beta-Defensin Antimicrobial Peptide in Atlantic Cod with Stimulatory Effect on Phagocytic Activity

    PubMed Central

    Ruangsri, Jareeporn; Kitani, Yoichiro; Kiron, Viswanath; Lokesh, Jep; Brinchmann, Monica F.; Karlsen, Bård Ove; Fernandes, Jorge M. O.

    2013-01-01

    A novel defensin antimicrobial peptide gene was identified in Atlantic cod, Gadus morhua. This three exon/two intron defensin gene codes for a peptide precursor consisting of two domains: a signal peptide of 26 amino acids and a mature peptide of 40 residues. The mature cod defensin has six conserved cysteine residues that form 1–5, 2–4 and 3–6 disulphide bridges. This pattern is typical of beta-defensins and this gene was therefore named cod beta-defensin (defb). The tertiary structure of Defb exhibits an α/β fold with one α helix and β1β2β3 sheets. RT-PCR analysis indicated that defb transcripts were present mainly in the swim bladder and peritoneum wall but could also be detected at moderate to low levels in skin, head- and excretory kidneys. In situ hybridisation revealed that defb was specifically expressed by cells located in the swim bladder submucosa and the oocytes. During embryonic development, defb gene transcripts were detectable from the golden eye stage onwards and their expression was restricted to the swim bladder and retina. Defb was differentially expressed in several tissues following antigenic challenge with Vibrio anguillarum, being up-regulated up to 25-fold in head kidney. Recombinant Defb displayed antibacterial activity, with a minimal inhibitory concentration of 0.4–0.8 µM and 25–50 µM against the Gram-(+) bacteria Planococcus citreus and Micrococcus luteus, respectively. In addition, Defb stimulated phagocytic activity of cod head kidney leucocytes in vitro. These findings imply that beta-defensins may play an important role in the innate immune response of Atlantic cod. PMID:23638029

  15. Assessing the antimicrobial activities of Ocins.

    PubMed

    Choyam, Shilja; Lokesh, Dhanashree; Kempaiah, Bettadaiah Bheemakere; Kammara, Rajagopal

    2015-01-01

    The generation of a zone of inhibition on a solid substrate indicates the bioactivity of antimicrobial peptides such as bacteriocin and enterocin. The indicator strain plays a significant role in bacteriocin assays. Other characteristics of bacteriocins, such as their dispersal ability and the different zymogram components, also affect bacteriocin assays. However, universal well diffusion assays for antimicrobials, irrespective of their ability to diffuse (bacteriocin and enterocin), do not exist. The ability of different zymography components to generate non-specific activities have rarely been explored in the literature. The purpose of the present work was to evaluate the impact of major factors (diffusion and rate of diffusion) in a solid substrate bioassay, and to document the adverse effects of sodium dodecyl sulfate in zymograms used to estimate the approximate molecular weight of bacteriocins. PMID:26441952

  16. Assessing the antimicrobial activities of Ocins

    PubMed Central

    Choyam, Shilja; Lokesh, Dhanashree; Kempaiah, Bettadaiah Bheemakere; Kammara, Rajagopal

    2015-01-01

    The generation of a zone of inhibition on a solid substrate indicates the bioactivity of antimicrobial peptides such as bacteriocin and enterocin. The indicator strain plays a significant role in bacteriocin assays. Other characteristics of bacteriocins, such as their dispersal ability and the different zymogram components, also affect bacteriocin assays. However, universal well diffusion assays for antimicrobials, irrespective of their ability to diffuse (bacteriocin and enterocin), do not exist. The ability of different zymography components to generate non-specific activities have rarely been explored in the literature. The purpose of the present work was to evaluate the impact of major factors (diffusion and rate of diffusion) in a solid substrate bioassay, and to document the adverse effects of sodium dodecyl sulfate in zymograms used to estimate the approximate molecular weight of bacteriocins. PMID:26441952

  17. Effective antimicrobial activity of Cbf-14, derived from a cathelin-like domain, against penicillin-resistant bacteria.

    PubMed

    Ma, Lingman; Wang, Yanrong; Wang, Mengxiao; Tian, Yuwei; Kang, Wei; Liu, Hanhan; Wang, Hui; Dou, Jie; Zhou, Changlin

    2016-05-01

    Cbf-14, a cationic peptide derived from a cathelin-like domain, was designed by inserting the highly α-helical sequence RLLR into an antibacterial sequence and deleting the inactive amino acids in Cbf-K16. Clinical penicillin-resistant isolates as well as NDM-1-carrying Escherichia coli and a correspondingly infected mice model were employed to evaluate Cbf-14 antibacterial activity. The results showed that Cbf-14 possessed potent antimicrobial effects with an MIC of 8-64 μg/ml, and killed almost all bacteria within 240 min. Cbf-14-treated mice achieved an 80% survival rate and approximate 2.5 log unit reduction in CFU in tissues; additionally, this peptide significantly suppressed the production of pro-inflammatory cytokines by the disaggregation of lipopolysaccharide (LPS), suggesting its anti-inflammatory effects. Furthermore, Cbf-14, concentration higher than 2 × MIC value, increased membrane uptake to NPN and PI dye by 96.2% and 63.7%, respectively, neutralised the negative zeta potential of LPS and bacteria surface, and induced 100% leakage of liposome-entrapped calcein and cytoplasmic membrane disruption of E. coli, indicating obvious membrane permeation. Finally, it bound to DNA and respectively evoked 85.0% and 63.3% inhibition of gene replication and protein expression of NDM-1 at sub-MIC concentration in E. coli BL21 (DE3)-NDM-1. These data indicated that Cbf-14 possessed effective antimicrobial activity against penicillin-resistant bacteria in vitro/vivo through membrane disruption, DNA binding, down-regulating NDM-1 expression by plasmid replication inhibition, and anti-inflammatory activity by LPS disaggregation, suggesting a potential anti-infective clinical agent. PMID:26897538

  18. Antimicrobial activity of garlic against oral streptococci.

    PubMed

    Groppo, F C; Ramacciato, J C; Motta, R H L; Ferraresi, P M; Sartoratto, A

    2007-05-01

    The antimicrobial activity of two garlic clones' (1: purple and 2: white) crude extracts against oral microbiota was evaluated in vitro (study 1) and in vivo (study 2). Study 1 consisted of the evaluation of minimum inhibitory (MIC) and bactericidal (MBC) concentrations against nine streptococci strains. In study 2, a 2.5% garlic (clone 2) solution was used as a mouthwash in a 5-week study by 30 subjects. Blood agar and Mitis Salivarius Bacitracin agar were inoculated with subjects' saliva to quantify oral microorganisms and mutans streptococci. Study 1 showed MIC ranging from 0.5 to 32.0 mg ml(-1) for clone 2 and from 8 to 64.0 mg ml(-1) for clone 1. MBC ranged from 1.0 to 128.0 mg ml(-1) and from 8.0 to 128.0 mg ml(-1) regarding clones 2 and 1 respectively. Study 2 showed that 2.5% garlic mouthwash solution had good antimicrobial activity against mutans streptococci and oral microorganisms. Maintenance of reduced salivary levels of streptococci was observed after 2 weeks at the end of mouthwash use. Unpleasant taste (100%), halitosis (90%) and nausea (30%) were reported by subjects after the end of the study. It was concluded that the garlic clones have antimicrobial properties in vitro against streptococci and anticariogenic properties against oral microorganism in spite of its adverse effects. PMID:17461963

  19. Antimicrobial activity of extracts of Terminalia catappa root.

    PubMed

    Pawar, S P; Pal, S C

    2002-06-01

    The effect against bacteria of petroleum ether (60-80 degrees C), chloroform and methanolic extract of dried root of Terminalia catappa Linn. (combrataceae) was employed by cup plate agar diffusion method. The chloroform extract showed prominent antimicrobial activity against S. aureus and E. coli as compared to other tested microorganisms, while petroleum ether extract was devoid of antimicrobial activity. The methanolic: extract exhibited MIC of 0.065 mg/ml against E. coli. and chloroform extract exhibited MIC of 0.4 mg/ml against S. aureus The chloroform has well as methanolic extracts showed good antimicrobial activity against Gram positive and Gram negative microorganisms. PMID:12649950

  20. Effects of montmorillonite on properties of methyl cellulose/carvacrol based active antimicrobial nanocomposites.

    PubMed

    Tunç, Sibel; Duman, Osman; Polat, Tülin Gürkan

    2016-10-01

    The effect of montmorillonite and carvacrol (as an antimicrobial agent) on the wettability, mechanical, gas barrier, thermal and color properties of methyl cellulose-based nanocomposite films was investigated. To make a comparison among the film samples, methyl cellulose (MC) film and methyl cellulose/montmorillonite (MC/MMT) and methyl cellulose/carvacrol/montmorillonite (MC/CRV/MMT) nanocomposite films with different clay concentration were prepared. The interactions among MMT, CRV and film matrix were characterized by FTIR spectroscopy. The contact angle value of MC film showed an increase of 2.5 fold with the incorporation of 60wt.% MMT into the film matrix. The addition of clay into the film matrix increased the melting point of MC film and improved the mechanical properties of film material. The tensile stress of pure MC film exhibited an increase of 9.2MPa in the presence of 60wt.% MMT. With the addition of MMT into the film matrixes, water vapor permeability values of MC film and MC/CRV film were decreased by 28% and 13%, respectively. The incorporation of 60wt.% MMT into the film matrix caused to a decrease of 47 fold for MC film and 16 fold for MC/CRV film in the oxygen permeability of film sample. The addition of CRV into MC film and MC/MMT nanocomposite films with different clay concentration reduced the mechanical strengths of film materials. Oxygen permeability values of MC film and MC/MMT nanocomposite films decreased with the inclusion of CRV into the film matrix. PMID:27312637

  1. The effect of standard heat and filtration processing procedures on antimicrobial activity and hydrogen peroxide levels in honey

    PubMed Central

    Chen, Cuilan; Campbell, Leona T.; Blair, Shona E.; Carter, Dee A.

    2012-01-01

    There is increasing interest in the antimicrobial properties of honey. In most honey types, antimicrobial activity is due to the generation of hydrogen peroxide (H2O2), but this can vary greatly among samples. Honey is a complex product and other components may modulate activity, which can be further affected by commercial processing procedures. In this study we examined honey derived from three native Australian floral sources that had previously been associated with H2O2-dependent activity. Antibacterial activity was seen in four red stringybark samples only, and ranged from 12 to 21.1% phenol equivalence against Staphylococcus aureus. Antifungal activity ranged from MIC values of 19–38.3% (w/v) against Candida albicans, and all samples were significantly more active than an osmotically equivalent sugar solution. All honey samples were provided unprocessed and following commercial processing. Processing was usually detrimental to antimicrobial activity, but occasionally the reverse was seen and activity increased. H2O2 levels varied from 0 to 1017 μM, and although samples with no H2O2 had little or no antimicrobial activity, some samples had relatively high H2O2 levels yet no antimicrobial activity. In samples where H2O2 was detected, the correlation with antibacterial activity was greater in the processed than in the unprocessed samples, suggesting other factors present in the honey influence this activity and are sensitive to heat treatment. Antifungal activity did not correlate with the level of H2O2 in honey samples, and overall it appeared that H2O2 alone was not sufficient to inhibit C. albicans. We conclude that floral source and H2O2 levels are not reliable predictors of the antimicrobial activity of honey, which currently can only be assessed by standardized antimicrobial testing. Heat processing should be reduced where possible, and honey destined for medicinal use should be retested post-processing to ensure that activity levels have not changed

  2. ANTIMICROBIAL EFFECT OF INTRACANAL SUBSTANCES

    PubMed Central

    Carreira, Cláudia de Moura; dos Santos, Silvana Soléo Ferreira; Jorge, Antônio Olavo Cardoso; Lage-Marques, José Luiz

    2007-01-01

    In some situations, endodontic infections do not respond to therapeutic protocol. In these cases, it is suggested the administration of an alternative intracanal medication that presents a wide spectrum of action and has an in-depth effect on the root canal system. The purpose of this study was to assess the antimicrobial action of ciprofloxacin, metronidazole and polyethylene glycol and natrosol vehicles with different associations and concentrations. The minimum inhibitory concentration (MIC) was determined by using the agar dilution method. The culture media (Müller-Hinton agar) were prepared containing antimicrobial agents at multiple two-fold dilutions of 0.25 to 16 µg/mL, and with the vehicles at the concentrations of 50, 45, 40, 35, 30 and 25%. Twenty-three microbial strains were selected for the study. Metronidazole was not capable of eliminating any of the tested microorganisms. The association of ciprofloxacin with metronidazole resulted in a reduction of the MIC. The vehicle polyethylene glycol inhibited the growth of 100% of the tested strains, while natrosol inhibited 18% of the strains. Ciprofloxacin formulations with polyethylene glycol presented better effects than those of formulations to which metronidazole was added. It was possible to conclude that ciprofloxacin presented antimicrobial action against all tested bacterial strains, and its association with metronidazole was synergic. The vehicle polyethylene glycol showed antimicrobial effect and the ciprofloxacin/polyethylene glycol association was the most effective combination for reducing the tested bacteria and yeasts. PMID:19089178

  3. Antimicrobial Activity against Intraosteoblastic Staphylococcus aureus

    PubMed Central

    Trouillet-Assant, Sophie; Riffard, Natacha; Tasse, Jason; Flammier, Sacha; Rasigade, Jean-Philippe; Chidiac, Christian; Vandenesch, François; Ferry, Tristan; Laurent, Frédéric

    2015-01-01

    Although Staphylococcus aureus persistence in osteoblasts, partly as small-colony variants (SCVs), can contribute to bone and joint infection (BJI) relapses, the intracellular activity of antimicrobials is not currently considered in the choice of treatment strategies for BJI. Here, antistaphylococcal antimicrobials were evaluated for their intraosteoblastic activity and their impact on the intracellular emergence of SCVs in an ex vivo osteoblast infection model. Osteoblastic MG63 cells were infected for 2 h with HG001 S. aureus. After killing the remaining extracellular bacteria with lysostaphin, infected cells were incubated for 24 h with antimicrobials at the intraosseous concentrations reached with standard therapeutic doses. Intracellular bacteria and SCVs were then quantified by plating cell lysates. A bactericidal effect was observed with fosfomycin, linezolid, tigecycline, oxacillin, rifampin, ofloxacin, and clindamycin, with reductions in the intracellular inocula of −2.5, −3.1, −3.9, −4.2, −4.9, −4.9, and −5.2 log10 CFU/100,000 cells, respectively (P < 10−4). Conversely, a bacteriostatic effect was observed with ceftaroline and teicoplanin, whereas vancomycin and daptomycin had no significant impact on intracellular bacterial growth. Ofloxacin, daptomycin, and vancomycin significantly limited intracellular SCV emergence. Overall, ofloxacin was the only molecule to combine an excellent intracellular activity while limiting the emergence of SCVs. These data provide a basis for refining the choice of antibiotics to prioritise in the management of BJI, justifying the combination of a fluoroquinolone for its intracellular activity with an anti-biofilm molecule, such as rifampin. PMID:25605365

  4. Antimicrobial activity of Epilobium spp. extracts.

    PubMed

    Battinelli, L; Tita, B; Evandri, M G; Mazzanti, G

    2001-01-01

    The antimicrobial activity of the Epilobium angustifolium, E. hirsutum, E. palustre, E. tetragonum and E. rosmarinifolium ethanolic extracts was studied in vitro on Gram-positive and Gram-negative bacteria, yeasts and fungi. The cytotoxicity of the extracts was also evaluated using the Artemia salina test. All the extracts showed antimicrobial activity in a range of concentrations between 10 and 650 microgml of dry extract. E. angustifolium and E. rosmarinifolium had the most broad spectrum of action inhibiting bacteria, yeasts and fungi. The extracts were devoid of toxicity on Artemia salina within the range of antimicrobial concentrations, suggesting that the action is selective on microorganisms. PMID:11482755

  5. Photodynamic antimicrobial activity of hypocrellin A.

    PubMed

    Su, Yujie; Sun, Jun; Rao, Shengqi; Cai, Yujie; Yang, Yanjun

    2011-04-01

    Antimicrobial photodynamic therapy is a recently developed therapeutic option that combines a non-toxic photosensitizer with harmless visible light to damage the microbial cell. Hypocrellin A (HA), a natural occurring lipid-soluble perylenequinone pigment, has gained considerable interest since its anticancer and antiviral activities have been reported. Here, we examined the antimicrobial activity of HA against Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Salmonella typhimurium). The results indicate that HA has a photodynamic antimicrobial activity against both Gram-positive and Gram-negative bacteria when CaCl(2) or MgCl(2) was employed. A loose binding has been established between HA and the organisms. Molecular oxygen is significantly involved in the photodynamic action of HA. Furthermore, HA maintains a photodynamic activity in terms of both types I and II reactions. Our results confirm the potential of HA to be used as a photosensitizer in antimicrobial photodynamic therapy. PMID:21300554

  6. The effect of copper(II), iron(II) sulphate, and vitamin C combinations on the weak antimicrobial activity of (+)-catechin against Staphylococcus aureus and other microbes.

    PubMed

    Holloway, Andrew C; Mueller-Harvey, Irene; Gould, Simon W J; Fielder, Mark D; Naughton, Declan P; Kelly, Alison F

    2012-12-01

    Few attempts have been made to improve the activity of plant compounds with low antimicrobial efficacy. (+)-Catechin, a weak antimicrobial tea flavanol, was combined with putative adjuncts and tested against different species of bacteria. Copper(II) sulphate enhanced (+)-catechin activity against Pseudomonas aeruginosa but not Staphylococcus aureus, Proteus mirabilis or Escherichia coli. Attempts to raise the activity of (+)-catechin against two unresponsive species, S. aureus and E. coli, with iron(II) sulphate, iron(III) chloride, and vitamin C, showed that iron(II) enhanced (+)-catechin against S. aureus, but not E. coli; neither iron(III) nor combined iron(II) and copper(II), enhanced (+)-catechin activity against either species. Vitamin C enhanced copper(II) containing combinations against both species in the absence of iron(II). Catalase or EDTA added to active samples removed viability effects suggesting that active mixtures had produced H(2)O(2)via the action of added metal(II) ions. H(2)O(2) generation by (+)-catechin plus copper(II) mixtures and copper(II) alone could account for the principal effect of bacterial growth inhibition following 30 minute exposures as well as the antimicrobial effect of (+)-catechin-iron(II) against S. aureus. These novel findings about a weak antimicrobial flavanol contrast with previous knowledge of more active flavanols with transition metal combinations. Weak antimicrobial compounds like (+)-catechin within enhancement mixtures may therefore be used as efficacious agents. (+)-Catechin may provide a means of lowering copper(II) or iron(II) contents in certain crop protection and other products. PMID:23138340

  7. Hurdle Effect of Antimicrobial Activity Achieved by Time Differential Releasing of Nisin and Chitosan Hydrolysates from Bacterial Cellulose.

    PubMed

    Hsiao, Hui-Ling; Lin, Shih-Bin; Chen, Li-Chen; Chen, Hui-Huang

    2016-05-01

    We investigated the combined antimicrobial effect of nisin and chitosan hydrolysates (CHs) by regulating the antimicrobial reaction order of substances due to differential releasing rate from hydroxypropylmethylcellulose-modified bacterial cellulose (HBC). The minimum inhibitory concentration of nisin against Staphylococcus aureus and that of CHs against Escherichia coli were 6 IU and 200 μg/mL, respectively. Hurdle and additive effects in antimicrobial tests were observed when nisin was used 6 h before CH treatment against S. aureus; similar effects were observed when CH was used before nisin treatment against E. coli. Simultaneously combined treatment of nisin and CHs exhibited the low antimicrobial effect. HBC was then selected as the carrier for the controlled release of nisin and CHs. A 90% inhibition in the growth of S. aureus and E. coli was achieved when 30 IU-nisin-containing HBC and 62.5 μg/mL-CH-containing HBC were used simultaneously. The controlled release of nisin and CHs by using HBC minimized the interaction between nisin and CHs as well as increased the number of microbial targets. PMID:27074534

  8. In Vitro Antimicrobial Activity and Effect on Biofilm Production of a White Grape Juice (Vitis vinifera) Extract

    PubMed Central

    Filocamo, Angela; Bisignano, Carlo; Mandalari, Giuseppina; Navarra, Michele

    2015-01-01

    Background. The aim of the present study was to evaluate the antimicrobial effect of a white grape juice extract (WGJe) against a range of Gram-positive and Gram-negative bacteria, yeasts, and the fungus Aspergillus niger. WGJe was also tested on the production of bacterial biofilms in vitro. Results. WGJe inhibited in vitro most Gram-positive bacteria tested, Staphylococcus aureus ATCC 6538P being the most sensitive strain (MIC values of 3.9 μg/mL). The effect was bactericidal at the concentration of 500 μg/mL. Amongst the Gram-negative bacteria, Escherichia coli was the only susceptible strain (MIC and MBC of 2000 μg/mL). No effect on the growth of Candida sp. and the fungus Aspergillus niger was detected (MIC values > 2000 μg/mL). WGJe inhibited the biofilms formation of E. coli and Pseudomonas aeruginosa with a dose-dependent effect. Conclusions. WGJe exerted both bacteriostatic and bactericidal activity in vitro. The presented results could be used to develop novel strategies for the treatment of skin infections and against potential respiratory pathogens. PMID:26770255

  9. The effects of silver nanoparticles on antimicrobial activity of ProRoot mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM)

    PubMed Central

    Jonaidi-Jafari, Nematollah; Izadi, Morteza

    2016-01-01

    Background Although, mineral trioxide aggregate (MTA) and new experimental cement (CEM) are good root filling cements, but had no or low antimicrobial activities. The aim of this study was to evaluate the effects of addition of silver nanoparticles (SNP) to these two cements on antimicrobial effects against five most dental infection related microorganisms. Material and Methods Two suspensions of 100 and 200 ppm of SNP were prepared and 180 μl of microbial suspension with 1.5 × 108 CFU/ml of each respected microorganisms were re-suspended in deionized water or each of SNP suspensions. After that, 60 μg of MTA and CEM were added to each tube. In one tube, the mixture of all above mentioned microorganisms were added as a source of microorganism. Colonies were counted after 0, 24, 48, 72 and 96 hours intervals of incubation at 35°C on blood agar for evaluation of antimicrobial efficacy. Results MTA and CEM had antibacterial activities on all microorganisms’ strains except for Enterococcus faecalis and mixture group. MTA had better antibacterial activity than CEM but the difference was not significant (p<0.05). The combination of SNP with two cements resulted in significantly higher antimicrobial activities (p<0.05). Also, there was no statistically significant difference between two SNP concentrations (p>0.05). Conclusions Mixture of MTA and CEM with different concentrations of SNP significantly increased the antibacterial activity. Key words:Mineral trioxide aggregate, calcium-enriched mixture, silver nanoparticle, antimicrobial activity. PMID:26855701

  10. A new cryptic cationic antimicrobial peptide from human apolipoprotein E with antibacterial activity and immunomodulatory effects on human cells.

    PubMed

    Pane, Katia; Sgambati, Valeria; Zanfardino, Anna; Smaldone, Giovanni; Cafaro, Valeria; Angrisano, Tiziana; Pedone, Emilia; Di Gaetano, Sonia; Capasso, Domenica; Haney, Evan F; Izzo, Viviana; Varcamonti, Mario; Notomista, Eugenio; Hancock, Robert E W; Di Donato, Alberto; Pizzo, Elio

    2016-06-01

    Cationic antimicrobial peptides (AMPs) possess fast and broad-spectrum activity against both Gram-negative and Gram-positive bacteria, as well as fungi. It has become increasingly evident that many AMPs, including those that derive from fragments of host proteins, are multifunctional and able to mediate various immunomodulatory functions and angiogenesis. Among these, synthetic apolipoprotein-derived peptides are safe and well tolerated in humans and have emerged as promising candidates in the treatment of various inflammatory conditions. Here, we report the characterization of a new AMP corresponding to residues 133-150 of human apolipoprotein E. Our results show that this peptide, produced either by chemical synthesis or by recombinant techniques in Escherichia coli, possesses a broad-spectrum antibacterial activity. As shown for several other AMPs, ApoE (133-150) is structured in the presence of TFE and of membrane-mimicking agents, like SDS, or bacterial surface lipopolysaccharide (LPS), and an anionic polysaccharide, alginate, which mimics anionic capsular exo-polysaccharides of several pathogenic microorganisms. Noteworthy, ApoE (133-150) is not toxic toward several human cell lines and triggers a significant innate immune response, assessed either as decreased expression levels of proinflammatory cytokines in differentiated THP-1 monocytic cells or by the induction of chemokines released from PBMCs. This novel bioactive AMP also showed a significant anti-inflammatory effect on human keratinocytes, suggesting its potential use as a model for designing new immunomodulatory therapeutics. PMID:27028511

  11. Peptides and proteins with antimicrobial activity

    PubMed Central

    Coutinho, Henrique Douglas Melo; Lôbo, Katiuscia Menezes; Bezerra, Denise Aline Casimiro; Lôbo, Inalzuir

    2008-01-01

    The increase of microbial resistance to antibiotics has led to a continuing search for newer and more effective drugs. Antimicrobial peptides are generally found in animals, plants, and microorganisms and are of great interest to medicine, pharmacology, and the food industry. These peptides are capable of inhibiting pathogenic microorganisms. They can attack parasites, while causing little or no harm to the host cells. The defensins are peptides found in granules in the polymorphonuclear neutrophils (PMNs) and are responsible for the defense of the organism. Several animal defensins, like dermaseptin, antileukoprotease, protegrin, and others, have had their activities and efficacy tested and been shown to be effective against bacteria, fungi, and protists; there are also specific defensins from invertebrates, e.g., drosomycin and heliomicin; from plants, e.g., the types A and B; and the bacteriocins, e.g., acrocin, marcescin, etc. The aim of the present work was to compile a comprehensive bibliographic review of the diverse potentially antimicrobial peptides in an effort to systematize the current knowledge on these substances as a contribution for further researches. The currently available bibliography does not give a holistic approach on this subject. The present work intends to show that the mechanism of defense represented by defensins is promising from the perspective of its application in the treatment of infectious diseases in human, animals and plants. PMID:21264153

  12. Temporin L: antimicrobial, haemolytic and cytotoxic activities, and effects on membrane permeabilization in lipid vesicles.

    PubMed Central

    Rinaldi, Andrea C; Mangoni, Maria Luisa; Rufo, Anna; Luzi, Carla; Barra, Donatella; Zhao, Hongxia; Kinnunen, Paavo K J; Bozzi, Argante; Di Giulio, Antonio; Simmaco, Maurizio

    2002-01-01

    The temporins are a family of small, linear antibiotic peptides with intriguing biological properties. We investigated the antibacterial, haemolytic and cytotoxic activities of temporin L (FVQWFSKFLGRIL-NH2), isolated from the skin of the European red frog Rana temporaria. The peptide displayed the highest activity of temporins studied to date, against both human erythrocytes and bacterial and fungal strains. At variance with other known temporins, which are mainly active against Gram-positive bacteria, temporin L was also active against Gram-negative strains such as Pseudomonas aeruginosa A.T.C.C. 15692 and Escherichia coli D21 at concentrations comparable with those that are microbiocidal to Gram-positive bacteria. In addition, temporin L was cytotoxic to three different human tumour cell lines (Hut-78, K-562 and U-937), causing a necrosis-like cell death, although sensitivity to the peptide varied markedly with the specific cell line tested. A study of the interaction of temporin L with liposomes of different lipid compositions revealed that the peptide causes perturbation of bilayer integrity of both neutral and negatively charged membranes, as revealed by the release of a vesicle-encapsulated fluorescent marker, and that the action of the peptide is modulated to some extent by membrane lipid composition. In particular, the presence of negatively charged lipids in the model bilayer inhibits the lytic power of temporin L. We also show that the release of fluorescent markers caused by temporin L is size-dependent and that the peptide does not have a detergent-like effect on the membrane, suggesting that perturbation of bilayer organization takes place on a local scale, i.e. through the formation of pore-like openings. PMID:12133008

  13. In vitro screening of mare's milk antimicrobial effect and antiproliverative activity.

    PubMed

    Guri, Anilda; Paligot, Michele; Crèvecoeur, Sebastien; Piedboeuf, Benoit; Claes, Jonathan; Daube, Georges; Corredig, Milena; Griffiths, M W; Delcenserie, Veronique

    2016-01-01

    The aims of this study were to examine the effect of mare's milk on virulence gene expression of Salmonella Typhimurium and observe its potential activity on proliferation of adenocarcinoma Caco-2 cells. Different supernatants of mare's milk, raw or heat-treated at 65°C for 15 s or 30 min, were studied. The changes in hilA gene expression of Salmonella Typhimurium in presence of mare's milk supernatants were assessed using a reporter luminescent strain. A significant decrease in hilA gene expression was observed with all tested supernatants. Virulence gene expression was then assessed using qPCR on a wild-type strain of Salmonella Typhimurium. A significant decrease of hilA and ssrB2 gene expression was observed with raw milk supernatants but not with heat-treated supernatants. The same supernatants were administered to Caco-2 cells to measure their proliferation rate. A significant reduction of proliferative effect was observed only with raw milk supernatants. This study reports that raw mare's milk was able to modulate virulence gene expression of Salmonella Typhimurium and exerts antiproliferative effects on Caco-2 cells. These results may offer new approaches for promoting gastrointestinal health. PMID:26656278

  14. Access to effective antimicrobials: a worldwide challenge.

    PubMed

    Laxminarayan, Ramanan; Matsoso, Precious; Pant, Suraj; Brower, Charles; Røttingen, John-Arne; Klugman, Keith; Davies, Sally

    2016-01-01

    Recent years have seen substantial improvements in life expectancy and access to antimicrobials, especially in low-income and lower-middle-income countries, but increasing pathogen resistance to antimicrobials threatens to roll back this progress. Resistant organisms in health-care and community settings pose a threat to survival rates from serious infections, including neonatal sepsis and health-care-associated infections, and limit the potential health benefits from surgeries, transplants, and cancer treatment. The challenge of simultaneously expanding appropriate access to antimicrobials, while restricting inappropriate access, particularly to expensive, newer generation antimicrobials, is unique in global health and requires new approaches to financing and delivering health care and a one-health perspective on the connections between pathogen transmission in animals and humans. Here, we describe the importance of effective antimicrobials. We assess the disease burden caused by limited access to antimicrobials, attributable to resistance to antimicrobials, and the potential effect of vaccines in restricting the need for antibiotics. PMID:26603918

  15. Effect of Different Obturation Materials on Residual Antimicrobial Activity of 2% Chlorhexidine in Dentin at Different Time Intervals: An Ex Vivo Study

    PubMed Central

    Bolhari, Behnam; Dehghan, Somayyeh; Sharifian, Mohammad Reza; Bahador, Abbas

    2015-01-01

    Objectives: The aim of this study was to evaluate the effect of gutta percha/AH26 and Resilon/RealSeal SE on residual antimicrobial activity of chlorhexidine (CHX) in human root dentin and suggest the best filling material when CHX is used as final irrigant. Materials and Methods: One-hundred and forty-four single-rooted human teeth were selected for this study. Canals were instrumented to the apical size #35. Smear layer was removed using 5.25% NaOCl and 17% EDTA and then 108 teeth were irrigated with 2% CHX and randomly divided into three groups of gutta percha/AH26, Resilon/RealSeal SE and positive controls. Each group was divided into three subgroups for different time intervals (one, three and six weeks). Thirty-six teeth, as negative controls, were irrigated with saline and obturated with gutta percha/AH26 and Resilon/RealSeal SE. Dentin powder was prepared at the afore-mentioned intervals. After exposure to Enterococcus faecalis for 24 hours, colony forming units (CFUs) were counted and residual antimicrobial activity was calculated. The data were analyzed using the Kruskal Wallis test and one-way ANOVA. The significance level was set at P<0.05. Results: The antimicrobial activity of CHX gradually decreased in a time-dependent manner but it maintained over 95% of its antimicrobial activity after six weeks. Moreover, Resilon/RealSeal SE significantly decreased the antimicrobial activity of CHX in comparison with gutta-percha/AH26 (P<0.05). Conclusion: After a final irrigation with CHX, gutta-percha/AH26 is a better choice for root canal obturation. PMID:27252755

  16. Antimicrobial activity of polycationic peptides.

    PubMed

    Giacometti, A; Cirioni, O; Barchiesi, F; Del Prete, M S; Scalise, G

    1999-11-01

    The in vitro activity of six polycationic peptides, buforin II, cecropin P1, indolicidin, magainin II, nisin, and ranalexin, were evaluated against several clinical isolates of gram-positive and gram-negative aerobic bacteria, yeasts, Pneumocystis carinii and Cryptosporidium parvum, by using microbroth dilution methods. The peptides exhibited different antibacterial activities and rapid time-dependent killing. The gram-negative organisms were more susceptible to buforin II and cecropin P1, whereas buforin II and ranalexin were the most active compounds against the gram-positive strains. Similarly, ranalexin showed the highest activity against Candida spp., whereas magainin II exerted the highest anticryptococcal activity. Finally, the peptides showed high anti-Pneumocystis activity, whereas no compound had strong inhibitory effect on C. parvum. PMID:10612440

  17. The Antimicrobial Activity of Porphyrin Attached Polymers

    NASA Astrophysics Data System (ADS)

    Thompson, Lesley

    2008-03-01

    We are interested in testing the antimicrobial activity of a porphyrin that is attached to a polymer. The porphyrin (5-(4-carboxyphenyl)-10,15,20-tris-(4-pryridyl)) was synthesized from methyl 4-formyl benzoate, 4-pyridinecarboxaldehyde, and pyrrole and attached to a copolymer of polystyrene/poly(vinyl benzyl chloride), which was synthesized by free radical polymerization. The antimicrobial activity of the polymer-attached porphyrin was then determined for gram-negative E. Coli grown to 0.80 OD. In this procedure, glass slides were coated with polymer-attached porphyrin via dip-coating, and the E. Coli bacteria were plated in Luria Broth media. The plates were subsequently exposed to light overnight before they were incubated as porphyrins act as photo-sensitizers when irradiated with light. The polymer-attached porphyrin did exhibit antimicrobial activity and parameters that affect its efficiency will be discussed.

  18. Natural cinnamic acids, synthetic derivatives and hybrids with antimicrobial activity.

    PubMed

    Guzman, Juan David

    2014-01-01

    Antimicrobial natural preparations involving cinnamon, storax and propolis have been long used topically for treating infections. Cinnamic acids and related molecules are partly responsible for the therapeutic effects observed in these preparations. Most of the cinnamic acids, their esters, amides, aldehydes and alcohols, show significant growth inhibition against one or several bacterial and fungal species. Of particular interest is the potent antitubercular activity observed for some of these cinnamic derivatives, which may be amenable as future drugs for treating tuberculosis. This review intends to summarize the literature data on the antimicrobial activity of the natural cinnamic acids and related derivatives. In addition, selected hybrids between cinnamic acids and biologically active scaffolds with antimicrobial activity were also included. A comprehensive literature search was performed collating the minimum inhibitory concentration (MIC) of each cinnamic acid or derivative against the reported microorganisms. The MIC data allows the relative comparison between series of molecules and the derivation of structure-activity relationships. PMID:25429559

  19. Multidrug Pump Inhibitors Uncover Remarkable Activity of Plant Antimicrobials

    PubMed Central

    Tegos, George; Stermitz, Frank R.; Lomovskaya, Olga; Lewis, Kim

    2002-01-01

    Plant antimicrobials are not used as systemic antibiotics at present. The main reason for this is their low level of activity, especially against gram-negative bacteria. The reported MIC is often in the range of 100 to 1,000 μg/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. Major plant pathogens belong to the gram-negative bacteria, which makes the low level of activity of plant antimicrobials against this group of microorganisms puzzling. Gram-negative bacteria have an effective permeability barrier, comprised of the outer membrane, which restricts the penetration of amphipathic compounds, and multidrug resistance pumps (MDRs), which extrude toxins across this barrier. It is possible that the apparent ineffectiveness of plant antimicrobials is largely due to the permeability barrier. We tested this hypothesis in the present study by applying a combination of MDR mutants and MDR inhibitors. A panel of plant antimicrobials was tested by using a set of bacteria representing the main groups of plant pathogens. The human pathogens Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica serovar Typhimurium were also tested. The results show that the activities of the majority of plant antimicrobials were considerably greater against the gram-positive bacteria Staphylococcus aureus and Bacillus megaterium and that disabling of the MDRs in gram-negative species leads to a striking increase in antimicrobial activity. Thus, the activity of rhein, the principal antimicrobial from rhubarb, was potentiated 100- to 2,000-fold (depending on the bacterial species) by disabling the MDRs. Comparable potentiation of activity was observed with plumbagin, resveratrol, gossypol, coumestrol, and berberine. Direct measurement of the uptake of berberine, a model plant antimicrobial, confirmed that disabling of the MDRs strongly increases the level of penetration of berberine into the cells of gram-negative bacteria. These

  20. Antimicrobial activity of different Finnish monofloral honeys against human pathogenic bacteria

    PubMed Central

    Huttunen, Sanna; Riihinen, Kaisu; Kauhanen, Jussi; Tikkanen-Kaukanen, Carina

    2013-01-01

    The antimicrobial activity and phenolic compounds of five Finnish honey products against important human pathogens Streptococcus pneumoniae, S. pyogenes, Staphylococcus aureus, and methicillin-resistant S. aureus were analyzed. Microbroth dilution method and HPLC-DAD were used in antimicrobial testing and phenolic compound determination, respectively. Significant antimicrobial activity (p < 0.01) against all the tested pathogens was found from willow herb (Epilobium angustifolium), heather (Calluna vulgaris), and buckwheat (Fagopyrum esculentum) honeys. This is the first report on antimicrobial activity of Finnish monofloral honeys against streptococcal and staphylococcal bacteria. To our knowledge this is also the first report on the antimicrobial effect of honey against S. pneumoniae. PMID:23278378

  1. Antimicrobial activity of different Finnish monofloral honeys against human pathogenic bacteria.

    PubMed

    Huttunen, Sanna; Riihinen, Kaisu; Kauhanen, Jussi; Tikkanen-Kaukanen, Carina

    2013-09-01

    The antimicrobial activity and phenolic compounds of five Finnish honey products against important human pathogens Streptococcus pneumoniae, S. pyogenes, Staphylococcus aureus, and methicillin-resistant S. aureus were analyzed. Microbroth dilution method and HPLC-DAD were used in antimicrobial testing and phenolic compound determination, respectively. Significant antimicrobial activity (p < 0.01) against all the tested pathogens was found from willow herb (Epilobium angustifolium), heather (Calluna vulgaris), and buckwheat (Fagopyrum esculentum) honeys. This is the first report on antimicrobial activity of Finnish monofloral honeys against streptococcal and staphylococcal bacteria. To our knowledge this is also the first report on the antimicrobial effect of honey against S. pneumoniae. PMID:23278378

  2. Antimicrobial Activity of Protamine against Oral Microorganisms.

    PubMed

    Kim, Yeon-Hee; Kim, Sang Moo; Lee, Si Young

    2015-01-01

    Protamine is an arginine-rich polycationic protein extracted from sperm cells of vertebrates including fishes such as salmon. The purpose of this study was to investigate the suppressive effects of protamine on the growth of oral pathogens for possible usage in dental materials. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by the microdilution method. Twelve strains of oral viridans streptococci, Actinomyces naeslundii, Actinomyces odontolyticus, Enterococcus faecalis, Lactobacillus acidophilus, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis and Candida albicans were suppressed by protamine. MIC and MBC values were between 0.009 ~ 20 mg/mL and 0.019 ~ 80 mg/mL, respectively. The bactericidal activities of protamine against susceptible bacterial species were dependent on the concentration of protamine and incubation time. Based on the results of this study, protamine would be a useful compound for the development of antimicrobial agents against oral pathogens in dental materials. PMID:26699859

  3. Use of rosemary, oregano, and a commercial blend of essential oils in broiler chickens: in vitro antimicrobial activities and effects on growth performance.

    PubMed

    Mathlouthi, N; Bouzaienne, T; Oueslati, I; Recoquillay, F; Hamdi, M; Urdaci, M; Bergaoui, R

    2012-03-01

    The present study was conducted to characterize the in vitro antimicrobial activities of 3 essential oils [oregano, rosemary, and a commercial blend of essential oils (BEO)] against pathogenic and nonpathogenic bacteria and to evaluate their effects on broiler chicken performances. The chemical composition of the essential oils was determined using the gas chromatography interfaced with a mass spectroscopy. The disc diffusion method, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) were applied for the determination of antimicrobial activities of essential oils. In vivo study, a total of seven hundred fifty 1-d-old male broiler chickens were assigned to 6 dietary treatment groups: basal diet (control; CON), CON + 44 mg of avilamycin/kg (A), CON + 100 mg of rosemary essential oil/kg (ROS), CON + 100 mg of oregano essential oil/kg (OR), CON + 50 mg of rosemary and 50 mg of oregano essential oils/kg (RO), and CON + 1,000 mg of BEO/kg (essential oil mixture, EOM). The essential oils isolated from rosemary and oregano were characterized by their greater content of 1,8-cineole (49.99%) and carvacrol (69.55%), respectively. The BEO was mainly represented by the aldehyde (cinnamaldehyde) and the monoterpene (1,8-cineole) chemical groups. The results of the disc diffusion method indicated that the rosemary essential oil had antibacterial activity (P ≤ 0.05) against only 3 pathogenic bacteria, Escherichia coli (8 mm), Salmonella indiana (11 mm), and Listeria innocua (9 mm). The essential oil of oregano had antimicrobial activities (P ≤ 0.05) on the same bacteria as rosemary but also on Staphylococcus aureus (22 mm) and Bacillus subtilis (12 mm). Oregano essential oil had greater (P ≤ 0.05) antimicrobial activities against pathogenic bacteria than rosemary essential oil but they had no synergism between them. The BEO showed an increased antimicrobial activity (P ≤ 0.05) against all studied bacteria (pathogenic and

  4. Bacillus clausii probiotic strains: antimicrobial and immunomodulatory activities.

    PubMed

    Urdaci, Maria C; Bressollier, Philippe; Pinchuk, Irina

    2004-07-01

    The clinical benefits observed with probiotic use are mainly attributed to the antimicrobial substances produced by probiotic strains and to their immunomodulatory effects. Currently, the best-documented probiotic bacteria used in human therapy are lactic acid bacteria. In contrast, studies aiming to characterize the mechanisms responsible for the probiotic beneficial effects of Bacillus are rare. The current work seeks to contribute to such characterization by evaluating the antimicrobial and immunomodulatory activities of probiotic B. clausii strains. B. clausii strains release antimicrobial substances in the medium. Moreover, the release of these antimicrobial substances was observed during stationary growth phase and coincided with sporulation. These substances were active against Gram-positive bacteria, in particular against Staphylococcus aureus, Enterococcus faecium, and Clostridium difficile. The antimicrobial activity was resistant to subtilisin, proteinase K, and chymotrypsin treatment, whereas it was sensitive to pronase treatment. The evaluation of the immunomodulatory properties of probiotic B. clausii strains was performed in vitro on Swiss and C57 Bl/6j murine cells. The authors demonstrate that these strains, in their vegetative forms, are able to induce NOS II synthetase activity, IFN-gamma production, and CD4 T-cell proliferation. PMID:15220667

  5. Antimicrobial and antibiofilm activity of pleurocidin against cariogenic microorganisms.

    PubMed

    Tao, Rui; Tong, Zhongchun; Lin, Yuan; Xue, Yunpeng; Wang, Wei; Kuang, Rong; Wang, Ping; Tian, Yu; Ni, Longxing

    2011-08-01

    Dental caries is a common oral bacterial infectious disease of global concern. Prevention and treatment of caries requires control of the dental plaque formed by pathogens such as Streptococcus mutans and Streptococcus sobrinus. Pleurocidin, produced by Pleuronectes americanus, is an antimicrobial peptide that exerts broad-spectrum activity against pathogenic bacteria and fungi. Moreover, pleurocidin shows less hemolysis and is less toxic than other natural peptides. In the present study, we investigated whether pleurocidin is an effective antibiotic peptide against common cariogenic microorganisms and performed a preliminary study of the antimicrobial mechanism. We assayed minimal inhibitory concentration (MIC), minimal bactericide concentration (MBC) and bactericidal kinetics and performed a spot-on-lawn assay. The BioFlux system was used to generate bacterial biofilms under controllable flow. Fluorescence microscopy and confocal laser scanning microscopy (CLSM) were used to analyze and observe biofilms. Scanning electron microscopy was used to observe the bacterial membrane. MIC and MBC results showed that pleurocidin had different antimicrobial activities against the tested oral strains. Although components of saliva could affect antimicrobial activity, pleurocidin dissolved in saliva still showed antimicrobial effects against oral microorganisms. Furthermore, pleurocidin showed a favorable killing effect against BioFlux flow biofilms in vitro. Our findings suggest that pleurocidin has the potential to kill dental biofilms and prevent dental caries. PMID:21703317

  6. [Antimicrobial activity of cefodizime against clinical isolates].

    PubMed

    Suzuki, Y; Ishihara, R; Ishii, Y; Nakazawa, A; Deguchi, K; Matsumoto, Y; Nishinari, C; Nakane, Y; Fukumoto, T

    1996-10-01

    In order to evaluate antimicrobial activity of cefodizime (CDZM), minimum inhibitory concentrations (MICs) of CDZM and control drugs were determined against clinical isolates collected from nation-wide medical institutions and in our laboratory from September to December of 1992 and from September to December of 1995. The results are summarized as follows: 1. Bacterial species with no or few strains resistant to CDZM included Streptococcus pyogenes, Haemophilus influenzae, Citrobacter koseri, Proteus mirabilis and Neisseria gonorrhoeae. The range of MIC values of CDZM against Klebsiella pneumoniae was spread. Other strains, Streptococcus pneumoniae, Moraxella subgenus Branhamella catarrhalis, Escherichia coli, Citrobacter freundii, Enterobacter spp., Serratia marcescens, Proteus vulgaris, Morganella morganii, Providencia spp., Peptostreptococcus spp. and Bacteroides fragilis group were resistant to cephems including CDZM. 2. The MIC90's of CDZM were 0.05 approximately 3.13 micrograms/ml against Streptococcus spp., H. influenzae, M. (B.) catarrhalis, E. coli, Klebsiella spp., P. mirabilis, N. gonorrhoeae and Peptostreptococcus spp. obtained in 1995 that were frequently found in daily treatment of infections. It appears that the effectiveness of CDZM was still relatively high against community-acquired infections. 3. Among H. influenzae isolates included imipenem (IPM)-resistant and norfloxacin (NFLX)-resistant strains. The MIC-range of CDZM against strains collected in 1995 including IPM-resistant and NFLX-resistant strains was < or = 0.025 approximately 0.1 microgram/ml, and MIC90 against these strains was 0.05 microgram/ml. CDZM showed strong antimicrobial activities against H. influenzae strains resistant to carbapenems and new-quinolones. PMID:8986558

  7. Comparative Evaluation of the Antimicrobial Activity of Different Antimicrobial Peptides against a Range of Pathogenic Bacteria

    PubMed Central

    Ebbensgaard, Anna; Mordhorst, Hanne; Overgaard, Michael Toft; Nielsen, Claus Gyrup; Aarestrup, Frank Møller; Hansen, Egon Bech

    2015-01-01

    Analysis of a Selected Set of Antimicrobial Peptides The rapid emergence of resistance to classical antibiotics has increased the interest in novel antimicrobial compounds. Antimicrobial peptides (AMPs) represent an attractive alternative to classical antibiotics and a number of different studies have reported antimicrobial activity data of various AMPs, but there is only limited comparative data available. The mode of action for many AMPs is largely unknown even though several models have suggested that the lipopolysaccharides (LPS) play a crucial role in the attraction and attachment of the AMP to the bacterial membrane in Gram-negative bacteria. We compared the potency of Cap18, Cap11, Cap11-1-18m2, Cecropin P1, Cecropin B, Bac2A, Bac2A-NH2, Sub5-NH2, Indolicidin, Melittin, Myxinidin, Myxinidin-NH2, Pyrrhocoricin, Apidaecin and Metalnikowin I towards Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, Aeromonas salmonicida, Listeria monocytogenes, Campylobacter jejuni, Flavobacterium psychrophilum, Salmonella typhimurium and Yersinia ruckeri by minimal inhibitory concentration (MIC) determinations. Additional characteristics such as cytotoxicity, thermo and protease stability were measured and compared among the different peptides. Further, the antimicrobial activity of a selection of cationic AMPs was investigated in various E. coli LPS mutants. Cap18 Shows a High Broad Spectrum Antimicrobial Activity Of all the tested AMPs, Cap18 showed the most efficient antimicrobial activity, in particular against Gram-negative bacteria. In addition, Cap18 is highly thermostable and showed no cytotoxic effect in a hemolytic assay, measured at the concentration used. However, Cap18 is, as most of the tested AMPs, sensitive to proteolytic digestion in vitro. Thus, Cap18 is an excellent candidate for further development into practical use; however, modifications that should reduce the protease sensitivity would be needed. In addition, our

  8. Antistaphylococcal Activity of Oritavancin and Its Synergistic Effect in Combination with Other Antimicrobial Agents

    PubMed Central

    Lin, Gengrong; Pankuch, Glenn; Appelbaum, Peter C.

    2014-01-01

    Oritavancin exhibited in vitro activity against 169 strains of vancomycin-susceptible, methicillin-resistant Staphylococcus aureus (MRSA) with MICs ranging from 0.03 to 1 μg/ml and against vancomycin-intermediate MRSA (VISA; n = 29), heterogeneous vancomycin-intermediate MRSA (hVISA; n = 5), and vancomycin-resistant MRSA (n = 5) strains, with MICs ranging from 0.12 to 4 μg/ml. For 10 MRSA isolates comprising 5 VISA and 5 hVISA strains, synergy between oritavancin and gentamicin, linezolid, or rifampin was observed against most of the strains tested using a time-kill method. PMID:25022588

  9. Antimicrobial activity of magnolol and honokiol against periodontopathic microorganisms.

    PubMed

    Chang, B; Lee, Y; Ku, Y; Bae, K; Chung, C

    1998-05-01

    Magnolol (1) and honokiol (2), main compounds from the stem bark of Magnolia obovata Thunb., were evaluated for an antimicrobial activity against periodontopathic microorganisms, Porphyromonas gingivalis, Prevotella gingivalis, Actinobacillus actinomycetemcomitans, Capnocytophaga gingivalis, and Veillonella disper, and a cytotoxicity against human gingival fibroblasts and epithelial cells. Our results indicate that magnolol and honokiol, although less potent than chlorhexidine, show a significant antimicrobial activity against these microorganisms, and a relatively low cytotoxic effect on human gingival cells. Thus, it is suggested that magnolol and honokiol may have a potential therapeutic use as a safe oral antiseptic for the prevention and the treatment of periodontal disease. PMID:9619121

  10. Combination Effects of Antimicrobial Peptides

    PubMed Central

    Yu, Guozhi; Baeder, Desiree Y.; Regoes, Roland R.

    2016-01-01

    Antimicrobial peptides (AMPs) are ancient and conserved across the tree of life. Their efficacy over evolutionary time has been largely attributed to their mechanisms of killing. Yet, the understanding of their pharmacodynamics both in vivo and in vitro is very limited. This is, however, crucial for applications of AMPs as drugs and also informs the understanding of the action of AMPs in natural immune systems. Here, we selected six different AMPs from different organisms to test their individual and combined effects in vitro. We analyzed their pharmacodynamics based on the Hill function and evaluated the interaction of combinations of two and three AMPs. Interactions of AMPs in our study were mostly synergistic, and three-AMP combinations displayed stronger synergism than two-AMP combinations. This suggests synergism to be a common phenomenon in AMP interaction. Additionally, AMPs displayed a sharp increase in killing within a narrow dose range, contrasting with those of antibiotics. We suggest that our results could lead a way toward better evaluation of AMP application in practice and shed some light on the evolutionary consequences of antimicrobial peptide interactions within the immune system of organisms. PMID:26729502

  11. Poisson Parameters of Antimicrobial Activity: A Quantitative Structure-Activity Approach

    PubMed Central

    Sestraş, Radu E.; Jäntschi, Lorentz; Bolboacă, Sorana D.

    2012-01-01

    A contingency of observed antimicrobial activities measured for several compounds vs. a series of bacteria was analyzed. A factor analysis revealed the existence of a certain probability distribution function of the antimicrobial activity. A quantitative structure-activity relationship analysis for the overall antimicrobial ability was conducted using the population statistics associated with identified probability distribution function. The antimicrobial activity proved to follow the Poisson distribution if just one factor varies (such as chemical compound or bacteria). The Poisson parameter estimating antimicrobial effect, giving both mean and variance of the antimicrobial activity, was used to develop structure-activity models describing the effect of compounds on bacteria and fungi species. Two approaches were employed to obtain the models, and for every approach, a model was selected, further investigated and found to be statistically significant. The best predictive model for antimicrobial effect on bacteria and fungi species was identified using graphical representation of observed vs. calculated values as well as several predictive power parameters. PMID:22606039

  12. Antimicrobial activity of Aspilia latissima (Asteraceae)

    PubMed Central

    Souza, Jeana M.E.; Chang, Marilene R.; Brito, Daniela Z.; Farias, Katyuce S.; Damasceno-Junior, Geraldo A.; Turatti, Izabel C.C.; Lopes, Norberto P.; Santos, Edson A.; Carollo, Carlos A.

    2015-01-01

    Abstract We evaluated the antimicrobial activity of Aspilia latissima - an abundant plant from the Brazilian Pantanal region - against Candida albicans, Candida parapsilosis, Candida krusei, Candida tropicalis, Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli and Staphylococcus aureus. The crude extracts and fractions showed activity in all tested microorganisms. The chloroform fraction of the leaves and roots showed the most antimicrobial activity against S. aureus, with an MIC of 500 μg/mL. This fraction was submitted to bioautographic assays to characterize the activity of the compounds. Two bands from the leaves (L-A and L-B) and three bands from the roots (R-C, R-D and R-E) were bioactive. Within the root-derived bands, the terpene derivatives stigmasterol, kaurenoic acid and kaura-9(11), 16-dien-18-oic acid were identified. Antibiotic activity of A. latissima is reported for the first time. PMID:26691468

  13. Antimicrobial Activity of Calcium Hydroxide in Endodontics: A Review

    PubMed Central

    Shalavi, S; Yazdizadeh, M

    2012-01-01

    The purpose of endodontic therapy is to preserve the patient's natural teeth without compromising the patient's local or systemic health. Calcium hydroxide has been included in several materials and antimicrobial formulations that are used in several treatment modalities in endodontics, such as inter-appointment intracanal medicaments. The purpose of this article was to review the antimicrobial properties of calcium hydroxide in endodontics. Calcium hydroxide has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. Calcium hydroxide has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also a valuable anti-endotoxin agent. However, its effect on microbial biofilms is controversial. PMID:23323217

  14. Antimicrobial activity of alcohols from Musca domestica.

    PubMed

    Gołębiowski, Marek; Dawgul, Małgorzata; Kamysz, Wojciech; Boguś, Mieczysława I; Wieloch, Wioletta; Włóka, Emilia; Paszkiewicz, Monika; Przybysz, Elżbieta; Stepnowski, Piotr

    2012-10-01

    Information on the stimulatory and inhibitory effects of cuticular alcohols on growth and virulence of insecticidal fungi is unavailable. Therefore, we set out to describe the content of cuticular and internal alcohols in the body of housefly larvae, pupae, males and females. The total cuticular alcohols in larvae, males and females of Musca domestica were detected in comparable amounts (4.59, 3.95 and 4.03 μg g(-1) insect body, respectively), but occurred in smaller quantities in pupae (2.16 μg g(-1)). The major free alcohol in M. domestica larvae was C(12:0) (70.4%). Internal alcohols of M. domestica larvae were not found. Among cuticular pupae alcohols, C(12:0) (31.0%) was the most abundant. In the internal lipids of pupae, only five alcohols were identified in trace amounts. The most abundant alcohol in males was C(24:0) (57.5%). The percentage content of cuticular C(24:0) in males and females (57.5 and 36.5%, respectively) was significantly higher than that of cuticular lipids in larvae and pupae (0.9 and 5.6%, respectively). Only two alcohols were present in the internal lipids of males in trace amounts (C(18:0) and C(20:0)). The most abundant cuticular alcohols in females were C(24:0) (36.5%) and C(12:0) (26.8%); only two alcohols (C(18:0) and C(20:0)) were detected in comparable amounts in internal lipids (3.61±0.32 and 5.01±0.42 μg g(-1), respectively). For isolated alcohols, antimicrobial activity against 10 reference strains of bacteria and fungi was determined. Individual alcohols showed approximately equal activity against fungal strains. C(14:0) was effective against gram-positive bacteria, whereas gram-negative bacteria were resistant to all tested alcohols. Mixtures of alcohols found in cuticular lipids of larvae, pupae, males and females of M. domestica generally presented higher antimicrobial activity than individual alcohols. In contrast, crude extracts containing both cuticular and internal lipids showed no antifungal activity against the

  15. Antimicrobial activity of syringic acid against Cronobacter sakazakii and its effect on cell membrane.

    PubMed

    Shi, Chao; Sun, Yi; Zheng, Zhiwei; Zhang, Xiaorong; Song, Kaikuo; Jia, Zhenyu; Chen, Yifei; Yang, Miaochun; Liu, Xin; Dong, Rui; Xia, Xiaodong

    2016-04-15

    Syringic acid (SA) has been reported to exhibit antibacterial ability against various microorganisms, but little work has been done on its effect on Cronobacter sakazakii. In this study, minimum inhibitory concentrations (MICs) of SA against various C. sakazakii strains were determined. Moreover, changes in intracellular ATP concentration, intracellular pH (pHin), membrane potential and membrane integrity were measured to evaluate the influence of SA on cell membrane. Finally, field emission scanning electron microscope (FESEM) was used to assess the morphological changes of bacterial cells caused by SA. It was shown that the MICs of SA against all tested C. sakazakii strains were 5mg/mL. SA retarded bacterial growth, and caused cell membrane dysfunction, which was evidenced by intracellular ATP concentration decrease, pHin reduction, cell membrane hyperpolarization and changes in cellular morphology. These findings indicated that SA has potential to be developed as a natural preservative to control C. sakazakii in foods associated with this pathogen and prevent related infections. PMID:26616929

  16. Molybdenum doped titanium dioxide photocatalytic coatings for use as hygienic surfaces: the effect of soiling on antimicrobial activity.

    PubMed

    Fisher, L; Ostovapour, S; Kelly, P; Whitehead, K A; Cooke, K; Storgårds, E; Verran, J

    2014-09-01

    Titanium dioxide (TiO2) surfaces doped with molybdenum (Mo) were investigated to determine if their photocatalytic ability could enhance process hygiene in the brewery industry. Doping TiO2 with Mo showed a 5-log reduction in bacterial counts within 4 to 24 h and a 1-log reduction in yeast numbers within 72 h. The presence of a dilute brewery soil on the surface did not interfere with antimicrobial activity. The TiO2-Mo surface was also active in the dark, showing a 5-log reduction in bacteria within 4 to 24 h and a 1-log reduction in yeast numbers within 72 h, suggesting it could have a novel dual function, being antimicrobial and photocatalytic. The study suggests the TiO2-Mo coating could act as a secondary barrier in helping prevent the build-up of microbial contamination on surfaces within the brewery industry, in particular in between cleaning/disinfection regimes during long production runs. PMID:25184432

  17. Morphology and oxygen incorporation effect on antimicrobial activity of silver thin films

    NASA Astrophysics Data System (ADS)

    Rebelo, Rita; Manninen, N. K.; Fialho, Luísa; Henriques, Mariana; Carvalho, Sandra

    2016-05-01

    Ag and AgxO thin films were deposited by non-reactive and reactive pulsed DC magnetron sputtering, respectively, with the final propose of functionalizing the SS316L substrate with antibacterial properties. The coatings were characterized chemically, physically and structurally. The coatings nanostructure was assessed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), while the coatings morphology was determined by scanning electron microscopy (SEM). The XRD and XPS analyses suggested that Ag thin film is composed by metallic Ag, which crystallizes in fcc-Ag phase, while the AgxO thin film showed both metallic Ag and Agsbnd O bonds, which crystalize in fcc-Ag and silver oxide phases. The SEM results revealed that Ag thin film formed a continuous layer, while AgxO layer was composed of islands with hundreds of nanometers surrounded by small nanoparticles with tens of nanometers. The surface wettability and surface tension parameters were determined by contact angle measurements, being found that Ag and AgxO surfaces showed very similar behavior, with all the surfaces showing a hydrophobic character. In order to verify the antibacterial behavior of the coatings, halo inhibition zone tests were realized for Staphylococcus epidermidis and Staphylococcus aureus. Ag coatings did not show antibacterial behavior, contrarily to AgxO coating, which presented antibacterial properties against the studied bacteria. The presence of silver oxide phase along with the development of different morphology was pointed as the main factors in the origin of the antibacterial effect found in AgxO thin film. The present study demonstrated that AgxO coating presented antibacterial behavior and its application in cardiovascular stents is promising.

  18. Effects of solution chemistry on antimicrobial activities of silver nanoparticles against Gordonia sp.

    PubMed

    Chen, Dong; Li, Xuan; Soule, Tanya; Yorio, Francis; Orr, Louisa

    2016-10-01

    Silver nanoparticles (NPs) are the largest and fastest growing category of nanotechnology-based medicines and consumer products. Silver can have great toxicity to some aquatic organisms and, as a biocidal agent, may also damage or alter the most abundant and vulnerable beneficial microorganisms in the environment, such as Gordonia sp. However, considering the complex chemical background of natural waters, silver NPs can have complicated interactions with background chemicals such as chloride, surfactants, and dissolved natural organic matters (NOM). The results of this study show that the average particle size and dispersivity of silver NPs and the surface characteristics play an important role in the toxicity of silver NPs. Aggregation was enhanced for silver NPs in 10mM NaNO3, but not much in 10mM NaCl due to reactions with chloride. However, the presence of 3mM sodium dodecyl sulfate (SDS) or 8mgC/L Suwannee River (SR) NOM appeared to reduce the aggregation of silver NPs. Regarding the bactericidal effect of silver NPs, solubility analysis suggests silver NPs inactivate Gordonia sp. differently from Ag(+) and/or a slow release of Ag(+) from silver NPs. When the silver NP concentration was raised from 7.3 to 29.2mg/L in DI water, the log inactivation rate of Gordonia sp. increased from 0.16±0.04 to 0.45±0.13. However, with 29.2mg/L silver NPs the log inactivation rate reached 1.40±0.26 in 3mM SDS. The presence of SRNOM mitigated the bactericidal efficacy of silver NPs due to surface coating/adsorption. On the other hand, 10mM NaCl reduced the log inactivation rate to 0.07±0.07 due to the formation of likely less toxic silver chloride species, such as AgCl, AgCl2(-), AgCl3(2-), and AgCl4(3-). PMID:27228306

  19. In vitro antimicrobial activity of Achyranthes coynei Sant.

    PubMed Central

    Ankad, Gireesh; Upadhya, Vinayak; Pai, Sandeep R.; Hegde, Harsha V.; Roy, Subarna

    2013-01-01

    Objective To validate the traditional use of Achyranthes coynei (A. coynei) Sant. as an antimicrobial in treatment of various infectious diseases. Methods Leaf extracts of A. coynei obtained through successive solvent extraction using petroleum ether, dichrloromethane, chloroform and methanol were used to screen the antimicrobial activity on five Gram positive, five Gram negative bacteria and two fungi. Minimum inhibitory concentration (MIC) was determined by two fold tube-dilution method. Results Methanolic leaf extract was more effective than other three extracts on the tested bacteria. Methanolic extract was efficient on Staphylococcus epidermis, Bacillus subtilis, Staphylococcus aureus and Pseudomonas aeruginosa with MIC values (0.62±0.00) mg/mL. The fungal organisms were less susceptible against extracts tested. Conclusions These results support the traditional use of leaf extracts of A. coynei as they have antimicrobial potential. Further studies are needed for establishing safety, toxicity and pharmacological activity with phytochemical investigation.

  20. ANTIMICROBIAL ACTIVITY OF EXTRACTS FROM ECUADORIAN LICHENS.

    PubMed

    Matvieieva, N A; Pasichnyk, L A; Zhytkevych, N V; Jacinto, Pabón Garcés Galo; Pidgorskyi, V S

    2015-01-01

    Antimicrobial activity of the ethanolic, isopropanolic, acetone, DMSO and aqueous extracts of the two lichen species from Ecuadorian highland, Usnea sp. and Stereocaulon sp. were explored in vitro against bacteria Bacillus subtilis, Escherichia coli and Staphylococcus aureus by the disc-diffusion method. Also the minimal inhibitory concentration (MIC) was determined. The strongest antimicrobial activity was found in DMSO extract of Usnea sp. compared to antibacterial activity of ciprfloxacin and cefazolin antibiotics. The inhibition zone was 28 mm, 30 mm, 31mm (DMSO extract, ciprfloxacin and cefazolin respectively) in case of B. subtilis usage as the test bacteria. MIC value for Usnea sp. and Stereocaulon sp. DMSO extracts was 0.4 mg/ml. E. coli was resistant to all kinds of extracts. The S. aureus sensitivity to lichen DMSO extracts was comparable to sensitivity of these microorganisms to tetracycline and vancomycin. Thereby, most kinds of extracts (ethanol, isopropanol, hexane, DMSO and acetone solvents) from Ecuadorian lichens Usnea sp. and Stereocaulon sp. with the exception of aqueous Stereocaulon sp. extracts possessed antibacterial activity against B. subtilis. DMSO lichen extracts had also antimicrobial activity against S. aureus. At the same time the extracts studied didn't demonstrate antibacterial activity against the representatives of the most common and harmful phytopathogenic bacteria tested. Further investigations of Ecuadorian lichens especially study of plants collected from extremal highland biotops can be very important in study of possibility of treatment of numerous diseases caused by pathogenic microorganisms. PMID:26214895

  1. Antimicrobial Peptide from the Wild Bee Hylaeus signatus Venom and Its Analogues: Structure-Activity Study and Synergistic Effect with Antibiotics.

    PubMed

    Nešuta, Ondřej; Hexnerová, Rozálie; Buděšínský, Miloš; Slaninová, Jiřina; Bednárová, Lucie; Hadravová, Romana; Straka, Jakub; Veverka, Václav; Čeřovský, Václav

    2016-04-22

    Venoms of hymenopteran insects have attracted considerable interest as a source of cationic antimicrobial peptides (AMPs). In the venom of the solitary bee Hylaeus signatus (Hymenoptera: Colletidae), we identified a new hexadecapeptide of sequence Gly-Ile-Met-Ser-Ser-Leu-Met-Lys-Lys-Leu-Ala-Ala-His-Ile-Ala-Lys-NH2. Named HYL, it belongs to the category of α-helical amphipathic AMPs. HYL exhibited weak antimicrobial activity against several strains of pathogenic bacteria and moderate activity against Candida albicans, but its hemolytic activity against human red blood cells was low. We prepared a set of HYL analogues to evaluate the effects of structural modifications on its biological activity and to increase its potency against pathogenic bacteria. This produced several analogues exhibiting significantly greater activity compared to HYL against strains of both Staphylococcus aureus and Pseudomonas aeruginosa even as their hemolytic activity remained low. Studying synergism of HYL peptides and conventional antibiotics showed the peptides act synergistically and preferentially in combination with rifampicin. Fluorescent dye propidium iodide uptake showed the tested peptides were able to facilitate entrance of antibiotics into the cytoplasm by permeabilization of the outer and inner bacterial cell membrane of P. aeruginosa. Transmission electron microscopy revealed that treatment of P. aeruginosa with one of the HYL analogues caused total disintegration of bacterial cells. NMR spectroscopy was used to elucidate the structure-activity relationship for the effect of amino acid residue substitution in HYL. PMID:26998557

  2. Antimicrobial and Immunomodulatory Activities of PR-39 Derived Peptides

    PubMed Central

    Veldhuizen, Edwin J. A.; Schneider, Viktoria A. F.; Agustiandari, Herfita; van Dijk, Albert; Tjeerdsma-van Bokhoven, Johanna L. M.; Bikker, Floris J.; Haagsman, Henk P.

    2014-01-01

    The porcine cathelicidin PR-39 is a host defence peptide that plays a pivotal role in the innate immune defence of the pig against infections. Besides direct antimicrobial activity, it is involved in immunomodulation, wound healing and several other biological processes. In this study, the antimicrobial- and immunomodulatory activity of PR-39, and N- and C-terminal derivatives of PR-39 were tested. PR-39 exhibited an unexpected broad antimicrobial spectrum including several Gram positive strains such as Bacillus globigii and Enterococcus faecalis. Of organisms tested, only Staphylococcus aureus was insensitive to PR-39. Truncation of PR-39 down to 15 (N-terminal) amino acids did not lead to major loss of activity, while peptides corresponding to the C-terminal part of PR-39 were hampered in their antimicrobial activity. However, shorter peptides were all much more sensitive to inhibition by salt. Active peptides induced ATP leakage and loss of membrane potential in Bacillus globigii and Escherichia coli, indicating a lytic mechanism of action for these peptides. Finally, only the mature peptide was able to induce IL-8 production in porcine macrophages, but some shorter peptides also had an effect on TNF-α production showing differential regulation of cytokine induction by PR-39 derived peptides. None of the active peptides showed high cytotoxicity highlighting the potential of these peptides for use as an alternative to antibiotics. PMID:24755622

  3. Antimicrobial activity of Michelia champaca.

    PubMed

    Khan, M R; Kihara, M; Omoloso, A D

    2002-12-01

    The methanol extracts of leaves, seeds, stem and root barks, stem and root heart-woods of Michelia champaca and the obtained fractions (petrol, dichloromethane, ethyl acetate, butanol) exhibited a broad spectrum of antibacterial activity. Fractionation drastically enhanced the level of activity particularly in all fractions of the stem bark and dichloromethane fraction of the root bark. Some fractions of the leaves, stem and root barks demonstrated antifungal activity against some of the tested moulds. Liriodenine was the active constituent of the root bark, with a broader and, in some cases, better level of activity as compared to the standard. PMID:12490248

  4. Antimicrobial silver: an unprecedented anion effect.

    PubMed

    Swathy, J R; Sankar, M Udhaya; Chaudhary, Amrita; Aigal, Sahaja; Anshup; Pradeep, T

    2014-01-01

    Silver is an indispensable metal but its use has to be minimised for sustainable growth. Much of the silver lost during use is unrecoverable; an example being its use as an antimicrobial agent, a property known since ages. While developing methods to create an affordable drinking water purifier especially for the developing world, we discovered that 50 parts per billion (ppb) of Ag(+) released continuously from silver nanoparticles confined in nanoscale cages is enough to cause antimicrobial activity in conditions of normal water. Here we show that the antibacterial and antiviral activities of Ag(+) can be enhanced ~1,000 fold, selectively, in presence of carbonate ions whose concentration was maintained below the drinking water norms. The protective layers of the organisms were affected during the carbonate-assisted antimicrobial activity. It is estimated that ~1,300 tons of silver can be saved annually using this new way to enhance its antimicrobial activity. PMID:25418185

  5. Antimicrobial silver: An unprecedented anion effect

    PubMed Central

    Swathy, J. R.; Sankar, M. Udhaya; Chaudhary, Amrita; Aigal, Sahaja; Anshup; Pradeep, T.

    2014-01-01

    Silver is an indispensable metal but its use has to be minimised for sustainable growth. Much of the silver lost during use is unrecoverable; an example being its use as an antimicrobial agent, a property known since ages. While developing methods to create an affordable drinking water purifier especially for the developing world, we discovered that 50 parts per billion (ppb) of Ag+ released continuously from silver nanoparticles confined in nanoscale cages is enough to cause antimicrobial activity in conditions of normal water. Here we show that the antibacterial and antiviral activities of Ag+ can be enhanced ~1,000 fold, selectively, in presence of carbonate ions whose concentration was maintained below the drinking water norms. The protective layers of the organisms were affected during the carbonate-assisted antimicrobial activity. It is estimated that ~1,300 tons of silver can be saved annually using this new way to enhance its antimicrobial activity. PMID:25418185

  6. Antioxidant, Antimicrobial and Antiproliferative Activities of Five Lichen Species

    PubMed Central

    Mitrović, Tatjana; Stamenković, Slaviša; Cvetković, Vladimir; Tošić, Svetlana; Stanković, Milan; Radojević, Ivana; Stefanović, Olgica; Čomić, Ljiljana; Đačić, Dragana; Ćurčić, Milena; Marković, Snežana

    2011-01-01

    The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells. PMID:21954369

  7. Antimicrobial activity of nerolidol and its derivatives against airborne microbes and further biological activities.

    PubMed

    Krist, Sabine; Banovac, Daniel; Tabanca, Nurhayat; Wedge, David E; Gochev, Velizar K; Wanner, Jürgen; Schmidt, Erich; Jirovetz, Leopold

    2015-01-01

    Nerolidol and its derivatives, namely cis-nerolidol, O-methyl-nerolidol, O-ethyl-nerolidol, (-)-α-bisabolol, trans,trans-farnesol and its main natural source cabreuva essential oil, were tested for their antimicrobial activity against airborne microbes and antifungal properties against plant pathogens. Among the tested compounds, α-bisabolol was the most effective antimicrobial agent and trans,trans-farnesol showed the best antifungal activity. PMID:25920237

  8. Antimicrobial activities of naphthazarins from Arnebia euchroma.

    PubMed

    Shen, Chien-Chang; Syu, Wan-Jr; Li, Shyh-Yuan; Lin, Chia-Hung; Lee, Gum-Hee; Sun, Chang-Ming

    2002-12-01

    Bioassay-directed fractionation of extract of Arnebia euchroma led to the isolation of alkannin (1), shikonin (2), and their derivatives (3-8) as the active principles against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The stereochemistry of alpha-methylbutyryl alkannin (8) is revealed for the first time, and the antimicrobial activity of 8 was compared with its corresponding diastereomer (9). The derivatives 3-9 showed stronger anti-MRSA activity [minimum inhibitory concentrations (MICs) ranged from 1.56 to 3.13 microg/mL] than alkannin or shikonin (MIC = 6.25 microg/mL). Anti-MRSA activity of derivatives was bactericidal with minimum bactericidal concentration (MBC)/MIC < or = 2. In a time-kill assay, the bactericidal activity against MRSA was achieved as rapidly as 2 h. The derivatives 3-9 were also active against vancomycin-resistant Enterococcus faecium (F935) and vancomycin-resistant Enterococcus faecalis (CKU-17) with MICs similar to those with MRSA. Aromatic ester derivatives were also synthesized for antimicrobial activity comparison. None of these compounds were active against Gram-negative bacteria tested. Their cytotoxicity was also evaluated on selected cancer cell lines, and they expressed their activity in the range 0.6-5.4 microg/mL (CD(50)). Our results indicate that the ester derivatives of alkannin are potential candidates of anti-MRSA and anti-VRE agents with antitumor activity. PMID:12502328

  9. Antimicrobials

    PubMed Central

    Murphy, Eileen F.; Clarke, Siobhan F.; Marques, Tatiana M.; Hill, Colin; Stanton, Catherine; Ross, R. Paul; O’Doherty, Robert M.; Shanahan, Fergus; Cotter, Paul D.

    2013-01-01

    Obesity is associated with a number of serious health consequences, including type 2 diabetes, cardiovascular disease and a variety of cancers among others and has been repeatedly shown to be associated with a higher risk of mortality. The relatively recent discovery that the composition and metabolic activity of the gut microbiota may affect the risk of developing obesity and related disorders has led to an explosion of interest in this distinct research field. A corollary of these findings would suggest that modulation of gut microbial populations can have beneficial effects with respect to controlling obesity. In this addendum, we summarize our recent data, showing that therapeutic manipulation of the microbiota using different antimicrobial strategies may be a useful approach for the management of obesity and metabolic conditions. In addition, we will explore some of the mechanisms that may contribute to microbiota-induced susceptibility to obesity and metabolic diseases. PMID:23018760

  10. Antioxidant, antimicrobial and neutrophil-modulating activities of herb extracts.

    PubMed

    Denev, Petko; Kratchanova, Maria; Ciz, Milan; Lojek, Antonin; Vasicek, Ondrej; Blazheva, Denitsa; Nedelcheva, Plamena; Vojtek, Libor; Hyrsl, Pavel

    2014-01-01

    The present study provides a comprehensive data on the antioxidant, antimicrobial and neutrophil-modulating activities of extracts from six medicinal plants--blackberry (Rubus fruticosus) leaves, chokeberry (Aronia melanocarpa) leaves, hawthorn (Crataegus monogyna) leaves, lady's mantle (Alchemilla glabra) aerial parts, meadowsweet (Filipendula ulmaria) aerial parts and raspberry (Rubus idaeus) leaves. In order to analyze the antioxidant activity of the herbs, several methods (ORAC, TRAP, HORAC and inhibition of lipid peroxidation) were used. Blackberry leaves and meadowsweet extracts revealed the highest antioxidant activities via all methods. All extracts studied blocked almost completely the opsonized zymosan particle-activated ROS production by neutrophils from human whole blood. On the other hand, the effect of extracts on phorbol myristate acetate-activated ROS production was much milder and even nonsignificant in the case of chokeberry leaves. This latter result suggests that extracts (apart from their antioxidative activity) interfere with the signaling cascade of phagocyte activation upstream of the protein kinase C activation. The antimicrobial activity of the investigated extracts against 11 human pathogens was investigated using three different methods. Meadowsweet and blackberry leaves extracts had the highest antimicrobial effect and the lowest minimal inhibiting concentrations (MICs) against the microorganisms tested. PMID:24945135

  11. Improving short antimicrobial peptides despite elusive rules for activity.

    PubMed

    Mikut, Ralf; Ruden, Serge; Reischl, Markus; Breitling, Frank; Volkmer, Rudolf; Hilpert, Kai

    2016-05-01

    Antimicrobial peptides (AMPs) can effectively kill a broad range of life threatening multidrug-resistant bacteria, a serious threat to public health worldwide. However, despite great hopes novel drugs based on AMPs are still rare. To accelerate drug development we studied different approaches to improve the antibacterial activity of short antimicrobial peptides. Short antimicrobial peptides seem to be ideal drug candidates since they can be synthesized quickly and easily, modified and optimized. In addition, manufacturing a short peptide drug will be more cost efficient than long and structured ones. In contrast to longer and structured peptides short AMPs seem hard to design and predict. Here, we designed, synthesized and screened five different peptide libraries, each consisting of 600 9-mer peptides, against Pseudomonas aeruginosa. Each library is presenting a different approach to investigate effectiveness of an optimization strategy. The data for the 3000 peptides were analyzed using models based on fuzzy logic bioinformatics and plausible descriptors. The rate of active or superior active peptides was improved from 31.0% in a semi-random library from a previous study to 97.8% in the best new designed library. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert. PMID:26687790

  12. Antimicrobial Activity of Indigofera suffruticosa.

    PubMed

    Leite, Sônia Pereira; Vieira, Jeymesson Raphael Cardoso; de Medeiros, Paloma Lys; Leite, Roberta Maria Pereira; de Menezes Lima, Vera Lúcia; Xavier, Haroudo Satiro; de Oliveira Lima, Edeltrudes

    2006-06-01

    Various organic and aqueous extracts of leaves of Indigofera suffruticosa Mill (Fabaceae) obtained by infusion and maceration were screened for their antibacterial and antifungal activities. The extracts were tested against 5 different species of human pathogenic bacteria and 17 fungal strains by the agar-solid diffusion method. Most of the extracts were devoid of antifungal and antibacterial activities, except the aqueous extract of leaves of I. suffruticosa obtained by infusion, which showed strong inhibitory activity against the Gram-positive bacteria Staphylococcus aureus with a minimal inhibitory concentration (MIC) of 5000 microg ml(-1). The MIC values to dermatophyte strains were 2500 microg ml(-1) against Trichophyton rubrum (LM-09, LM-13) and Microsporum canis. This study suggests that aqueous extracts of leaves of I. suffruticosa obtained by infusion can be used in the treatment of skin diseases caused by dermatophytes. PMID:16786057

  13. Antimicrobial Activity of Indigofera suffruticosa

    PubMed Central

    Leite, Sônia Pereira; Vieira, Jeymesson Raphael Cardoso; de Medeiros, Paloma Lys; Leite, Roberta Maria Pereira; de Menezes Lima, Vera Lúcia; Xavier, Haroudo Satiro; de Oliveira Lima, Edeltrudes

    2006-01-01

    Various organic and aqueous extracts of leaves of Indigofera suffruticosa Mill (Fabaceae) obtained by infusion and maceration were screened for their antibacterial and antifungal activities. The extracts were tested against 5 different species of human pathogenic bacteria and 17 fungal strains by the agar-solid diffusion method. Most of the extracts were devoid of antifungal and antibacterial activities, except the aqueous extract of leaves of I. suffruticosa obtained by infusion, which showed strong inhibitory activity against the Gram-positive bacteria Staphylococcus aureus with a minimal inhibitory concentration (MIC) of 5000 µg ml−1. The MIC values to dermatophyte strains were 2500 µg ml−1 against Trichophyton rubrum (LM-09, LM-13) and Microsporum canis. This study suggests that aqueous extracts of leaves of I. suffruticosa obtained by infusion can be used in the treatment of skin diseases caused by dermatophytes. PMID:16786057

  14. Destabilization of α-Helical Structure in Solution Improves Bactericidal Activity of Antimicrobial Peptides: Opposite Effects on Bacterial and Viral Targets

    PubMed Central

    Morris, Christopher J.; Fox, Marc A.; Gumbleton, Mark; Beck, Konrad

    2016-01-01

    We have previously examined the mechanism of antimicrobial peptides on the outer membrane of vaccinia virus. We show here that the formulation of peptides LL37 and magainin-2B amide in polysorbate 20 (Tween 20) results in greater reductions in virus titer than formulation without detergent, and the effect is replicated by substitution of polysorbate 20 with high-ionic-strength buffer. In contrast, formulation with polysorbate 20 or high-ionic-strength buffer has the opposite effect on bactericidal activity of both peptides, resulting in lesser reductions in titer for both Gram-positive and Gram-negative bacteria. Circular dichroism spectroscopy shows that the differential action of polysorbate 20 and salt on the virucidal and bactericidal activities correlates with the α-helical content of peptide secondary structure in solution, suggesting that the virucidal and bactericidal activities are mediated through distinct mechanisms. The correlation of a defined structural feature with differential activity against a host-derived viral membrane and the membranes of both Gram-positive and Gram-negative bacteria suggests that the overall helical content in solution under physiological conditions is an important feature for consideration in the design and development of candidate peptide-based antimicrobial compounds. PMID:26824944

  15. Chemical Composition, Antioxidant and Antimicrobial Activities of Thymus capitata Essential Oil with Its Preservative Effect against Listeria monocytogenes Inoculated in Minced Beef Meat

    PubMed Central

    El Abed, Nariman; Kaabi, Belhassen; Smaali, Mohamed Issam; Chabbouh, Meriem; Habibi, Kamel; Mejri, Mondher; Marzouki, Mohamed Nejib; Ben Hadj Ahmed, Sami

    2014-01-01

    The chemical composition, antioxidant and antimicrobial activities, and the preservative effect of Thymus capitata essential oil against Listeria monocytogenes inoculated in minced beef meat were evaluated. The essential oil extracted was chemically analyzed by gas chromatography-mass spectrometry. Nineteen components were identified, of which carvacrol represented (88.89%) of the oil. The antioxidant activity was assessed in vitro by using both the DPPH and the ABTS assays. The findings showed that the essential oil exhibited high antioxidant activity, which was comparable to the reference standards (BHT and ascorbic acid) with IC50 values of 44.16 and 0.463 μg/mL determined by the free-radical scavenging DPPH and ABTS assays, respectively. Furthermore, the essential oil was evaluated for its antimicrobial activity using disc agar diffusion and microdilution methods. The results demonstrated that the zone of inhibition varied from moderate to strong (15–80 mm) and the minimum inhibition concentration values ranged from 0.32 to 20 mg/mL. In addition, essential oil evaluated in vivo against Listeria monocytogenes showed clear and strong inhibitory effect. The application of 0.25 or 1% (v/w) essential oil of T. capitata to minced beef significantly reduced the L. monocytogenes population when compared to those of control samples (P-value  <0.01). PMID:24719640

  16. Chemical Composition, Antioxidant and Antimicrobial Activities of Thymus capitata Essential Oil with Its Preservative Effect against Listeria monocytogenes Inoculated in Minced Beef Meat.

    PubMed

    El Abed, Nariman; Kaabi, Belhassen; Smaali, Mohamed Issam; Chabbouh, Meriem; Habibi, Kamel; Mejri, Mondher; Marzouki, Mohamed Nejib; Ben Hadj Ahmed, Sami

    2014-01-01

    The chemical composition, antioxidant and antimicrobial activities, and the preservative effect of Thymus capitata essential oil against Listeria monocytogenes inoculated in minced beef meat were evaluated. The essential oil extracted was chemically analyzed by gas chromatography-mass spectrometry. Nineteen components were identified, of which carvacrol represented (88.89%) of the oil. The antioxidant activity was assessed in vitro by using both the DPPH and the ABTS assays. The findings showed that the essential oil exhibited high antioxidant activity, which was comparable to the reference standards (BHT and ascorbic acid) with IC50 values of 44.16 and 0.463 μ g/mL determined by the free-radical scavenging DPPH and ABTS assays, respectively. Furthermore, the essential oil was evaluated for its antimicrobial activity using disc agar diffusion and microdilution methods. The results demonstrated that the zone of inhibition varied from moderate to strong (15-80 mm) and the minimum inhibition concentration values ranged from 0.32 to 20 mg/mL. In addition, essential oil evaluated in vivo against Listeria monocytogenes showed clear and strong inhibitory effect. The application of 0.25 or 1% (v/w) essential oil of T. capitata to minced beef significantly reduced the L. monocytogenes population when compared to those of control samples (P-value  <0.01). PMID:24719640

  17. Destabilization of α-Helical Structure in Solution Improves Bactericidal Activity of Antimicrobial Peptides: Opposite Effects on Bacterial and Viral Targets.

    PubMed

    Ulaeto, David O; Morris, Christopher J; Fox, Marc A; Gumbleton, Mark; Beck, Konrad

    2016-04-01

    We have previously examined the mechanism of antimicrobial peptides on the outer membrane of vaccinia virus. We show here that the formulation of peptides LL37 and magainin-2B amide in polysorbate 20 (Tween 20) results in greater reductions in virus titer than formulation without detergent, and the effect is replicated by substitution of polysorbate 20 with high-ionic-strength buffer. In contrast, formulation with polysorbate 20 or high-ionic-strength buffer has the opposite effect on bactericidal activity of both peptides, resulting in lesser reductions in titer for both Gram-positive and Gram-negative bacteria. Circular dichroism spectroscopy shows that the differential action of polysorbate 20 and salt on the virucidal and bactericidal activities correlates with the α-helical content of peptide secondary structure in solution, suggesting that the virucidal and bactericidal activities are mediated through distinct mechanisms. The correlation of a defined structural feature with differential activity against a host-derived viral membrane and the membranes of both Gram-positive and Gram-negative bacteria suggests that the overall helical content in solution under physiological conditions is an important feature for consideration in the design and development of candidate peptide-based antimicrobial compounds. PMID:26824944

  18. Antimicrobial activity of Antarctic bryozoans: an ecological perspective with potential for clinical applications.

    PubMed

    Figuerola, Blanca; Sala-Comorera, Laura; Angulo-Preckler, Carlos; Vázquez, Jennifer; Jesús Montes, M; García-Aljaro, Cristina; Mercadé, Elena; Blanch, Anicet R; Avila, Conxita

    2014-10-01

    The antimicrobial activity of Antarctic bryozoans and the ecological functions of the chemical compounds involved remain largely unknown. To determine the significant ecological and applied antimicrobial effects, 16 ether and 16 butanol extracts obtained from 13 different bryozoan species were tested against six Antarctic (including Psychrobacter luti, Shewanella livingstonensis and 4 new isolated strains) and two bacterial strains from culture collections (Escherichia coli and Bacillus cereus). Results from the bioassays reveal that all ether extracts exhibited antimicrobial activity against some bacteria. Only one butanol extract produced inhibition, indicating that antimicrobial compounds are mainly lipophilic. Ether extracts of the genus Camptoplites inhibited the majority of bacterial strains, thus indicating a broad-spectrum of antimicrobial activity. Moreover, most ether extracts presented activities against bacterial strains from culture collections, suggesting the potential use of these extracts as antimicrobial drugs against pathogenic bacteria. PMID:25232675

  19. [Antimicrobial activity of orthodontic band cements].

    PubMed

    Pavic, J; Arriagada, M; Elgueta, J; García, C

    1990-01-01

    The prevalence of enamel decalcification and caries beneath orthodontic bands, has indicated the need for a new enamel binding adhesive orthodontic cement. The purpose of this study was to evaluate the antimicrobial activity, in vitro, on Streptococcus mutans and Lactobacillus, acidophillus, of three materials used to cements the orthodontic bands. The cements studied were: Zinc phosphate cement, Glass-ionomer cement, and Policarboxylate cement. Thirty petri plates were seeded with S. mutans, and thirty with L. acidophillus; on each plate three pellet were placed, one of each cement studied. Petri plates were incubated under microaerophilic conditions at 37 C, and checked at 72 hrs. for Streptococcus, mutans, and four days for Lactobacillus acidophillus to evaluate the inhibition zone. The results were tabulated for each material. It was demonstrated that exists important variations in the antimicrobial properties of the materials studied, as in the microbial sensitivity to these cements. PMID:2135908

  20. The Antimicrobial Activity of Different Mouthwashes in Malaysia

    PubMed Central

    Mat Ludin, C.M.; Md Radzi, J.

    2001-01-01

    Seven different brands of mouthwashes were assessed for the inhibition of growth of oral micro-organisms. The results showed wide variations in their effectiveness: Those containing cationic surfactants and complex organic nitrogenous compounds were more active than the older formulations based on phenols. A list was compiled ranking the mouthwashes according to their antimicrobial activity, which did not always agree with the manufacturer’s claims or indication for use. PMID:22893755

  1. The Effect of Anti-Inflammatory and Antimicrobial Herbal Remedy PADMA 28 on Immunological Angiogenesis and Granulocytes Activity in Mice

    PubMed Central

    Radomska-Leśniewska, Dorota M.; Skopiński, Piotr; Zdanowski, Robert; Lewicki, Sławomir; Kocik, Janusz; Skopińska-Różewska, Ewa; Stankiewicz, Wanda

    2013-01-01

    PADMA 28 is a herbal multicompound remedy that originates from traditional Tibetan medicine and possesses anti-inflammatory, antioxidant, antimicrobial, angioprotecting, and wound healing properties. The aim of the present study was to evaluate the influence of this remedy on immunological angiogenesis and granulocytes metabolic activity in Balb/c mice. Mice were fed daily, for seven days, with 5.8 mg of PADMA (calculated from recommended human daily dose) or 0.085 mg (dose in the range of active doses of other herbal extracts studied by us previously). Results. Highly significant increase of newly formed blood vessels number in ex vivo cutaneous lymphocyte-induced angiogenesis test (LIA) after grafting of Balb/c splenocytes from both dosage groups to F1 hybrids (Balb/c × C3H); increase of blood lymphocytes and granulocytes number only in mice fed with lower dose of remedy; and significant suppression of metabolic activity (chemiluminescence test) of blood granulocytes in mice fed with higher dose of PADMA. Conclusion. PADMA 28 behaves as a good stimulator of physiological angiogenesis, but for this purpose it should be used in substantially lower doses than recommended by producers for avoiding the deterioration of granulocyte function. PMID:23864768

  2. Antimicrobial activity of the metals and metal oxide nanoparticles.

    PubMed

    Dizaj, Solmaz Maleki; Lotfipour, Farzaneh; Barzegar-Jalali, Mohammad; Zarrintan, Mohammad Hossein; Adibkia, Khosro

    2014-11-01

    The ever increasing resistance of pathogens towards antibiotics has caused serious health problems in the recent years. It has been shown that by combining modern technologies such as nanotechnology and material science with intrinsic antimicrobial activity of the metals, novel applications for these substances could be identified. According to the reports, metal and metal oxide nanoparticles represent a group of materials which were investigated in respect to their antimicrobial effects. In the present review, we focused on the recent research works concerning antimicrobial activity of metal and metal oxide nanoparticles together with their mechanism of action. Reviewed literature indicated that the particle size was the essential parameter which determined the antimicrobial effectiveness of the metal nanoparticles. Combination therapy with the metal nanoparticles might be one of the possible strategies to overcome the current bacterial resistance to the antibacterial agents. However, further studies should be performed to minimize the toxicity of metal and metal oxide nanoparticles to apply as proper alternatives for antibiotics and disinfectants especially in biomedical applications. PMID:25280707

  3. Review of antimicrobial and antioxidative activities of chitosans in food.

    PubMed

    Friedman, Mendel; Juneja, Vijay K

    2010-09-01

    Interest in chitosan, a biodegradable, nontoxic, non-antigenic, and biocompatible biopolymer isolated from shellfish, arises from the fact that chitosans are reported to exhibit numerous health-related beneficial effects, including strong antimicrobial and antioxidative activities in foods. The extraordinary interest in the chemistry and application in agriculture, horticulture, environmental science, industry, microbiology, and medicine is attested by about 17,000 citations on this subject in the Scopus database. A special need exists to develop a better understanding of the role of chitosans in ameliorating foodborne illness. To contribute to this effort, this overview surveys and interprets our present knowledge of the chemistry and antimicrobial activities of chitosan in solution, as powders, and in edible films and coating against foodborne pathogens, spoilage bacteria, and pathogenic viruses and fungi in several food categories. These include produce, fruit juices, eggs and dairy, cereal, meat, and seafood products. Also covered are antimicrobial activities of chemically modified and nanochitosans, therapeutic properties, and possible mechanisms of the antimicrobial, antioxidative, and metal chelating effects. Further research is suggested in each of these categories. The widely scattered data on the multifaceted aspects of chitosan microbiology, summarized in the text and in 10 tables and 8 representative figures, suggest that low-molecular-weight chitosans at a pH below 6.0 presents optimal conditions for achieving desirable antimicrobial and antioxidative-preservative effects in liquid and solid foods. We are very hopeful that the described findings will be a valuable record and resource for further progress to improve microbial food safety and food quality. PMID:20828484

  4. Antimicrobial activity and chemical composition of some essential oils.

    PubMed

    Aridoğan, Buket Cicioğlu; Baydar, Hasan; Kaya, Selçuk; Demirci, Mustafa; Ozbaşar, Demir; Mumcu, Ethem

    2002-12-01

    In this study the composition and antimicrobial properties of essential oils obtained from Origanum onites, Mentha piperita, Juniperus exalsa, Chrysanthemum indicum, Lavandula hybrida, Rosa damascena, Echinophora tenuifolia, Foeniculum vulgare were examined. To evaluate the in vitro antibacterial activities of these eight aromatic extracts; their in vitro antimicrobial activities were determined by disk diffusion testing, according to the NCCLS criteria. Escherichia coli (ATTC 25922), Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATTC 27853 were used as standard test bacterial strains. Origanum onites recorded antimicrobial activity against all test bacteria, and was strongest against Staphylococcus aureus. For Rosa damascena, Mentha piperita and Lavandula hybrida antimicrobial activity was recorded only to Staphylococcus aureus. Juniperus exalsa, and Chrysanthemum indicum exhibited antibacterial activities against both Staphylococcus aureus and Escherichia coli. We also examined the in vitro antimicrobial activities of some components of the essential oils and found some components with antimicrobial activity. PMID:12510839

  5. Repurposing the Antihistamine Terfenadine for Antimicrobial Activity against Staphylococcus aureus

    PubMed Central

    2015-01-01

    Staphylococcus aureus is a rapidly growing health threat in the U.S., with resistance to several commonly prescribed treatments. A high-throughput screen identified the antihistamine terfenadine to possess, previously unreported, antimicrobial activity against S. aureus and other Gram-positive bacteria. In an effort to repurpose this drug, structure–activity relationship studies yielded 84 terfenadine-based analogues with several modifications providing increased activity versus S. aureus and other bacterial pathogens, including Mycobacterium tuberculosis. Mechanism of action studies revealed these compounds to exert their antibacterial effects, at least in part, through inhibition of the bacterial type II topoisomerases. This scaffold suffers from hERG liabilities which were not remedied through this round of optimization; however, given the overall improvement in activity of the set, terfenadine-based analogues provide a novel structural class of antimicrobial compounds with potential for further characterization as part of the continuing process to meet the current need for new antibiotics. PMID:25238555

  6. Antimicrobial activity of bone cements embedded with organic nanoparticles

    PubMed Central

    Perni, Stefano; Thenault, Victorien; Abdo, Pauline; Margulis, Katrin; Magdassi, Shlomo; Prokopovich, Polina

    2015-01-01

    Infections after orthopedic surgery are a very unwelcome outcome; despite the widespread use of antibiotics, their incidence can be as high as 10%. This risk is likely to increase as antibiotics are gradually losing efficacy as a result of bacterial resistance; therefore, novel antimicrobial approaches are required. Parabens are a class of compounds whose antimicrobial activity is employed in many cosmetic and pharmaceutical products. We developed propylparaben nanoparticles that are hydrophilic, thus expanding the applicability of parabens to aqueous systems. In this paper we assess the possibility of employing paraben nanoparticles as antimicrobial compound in bone cements. The nanoparticles were embedded in various types of bone cement (poly(methyl methacrylate) [PMMA], hydroxyapatite, and brushite) and the antimicrobial activity was determined against common causes of postorthopedic surgery infections such as: Staphylococcus aureus, methicillin-resistant S. aureus, Staphylococcus epidermidis, and Acinetobacter baumannii. Nanoparticles at concentrations as low as 1% w/w in brushite bone cement were capable of preventing pathogens growth, 5% w/w was needed for hydroxyapatite bone cement, while 7% w/w was required for PMMA bone cement. No detrimental effect was determined by the addition of paraben nanoparticles on bone cement compression strength and cytocompatibility. Our results demonstrate that paraben nanoparticles can be encapsulated in bone cement, providing concentration-dependent antimicrobial activity; furthermore, lower concentrations are needed in calcium phosphate (brushite and hydroxyapatite) than in acrylic (PMMA) bone cements. These nanoparticles are effective against a wide spectrum of bacteria, including those already resistant to the antibiotics routinely employed in orthopedic applications, such as gentamicin. PMID:26487803

  7. Molecular Design, Structures, and Activity of Antimicrobial Peptide-Mimetic Polymers

    PubMed Central

    Takahashi, Haruko; Palermo, Edmund F.; Yasuhara, Kazuma; Caputo, Gregory A.

    2014-01-01

    There is an urgent need for new antibiotics which are effective against drug-resistant bacteria without contributing to resistance development. We have designed and developed antimicrobial copolymers with cationic amphiphilic structures based on the mimicry of naturally occurring antimicrobial peptides. These copolymers exhibit potent antimicrobial activity against a broad spectrum of bacteria including methicillin-resistant Staphylococcus aureus with no adverse hemolytic activity. Notably, these polymers also did not result in any measurable resistance development in E. coli. The peptide-mimetic design principle offers significant flexibility and diversity in the creation of new antimicrobial materials and their potential biomedical applications. PMID:23832766

  8. Antimicrobial activity of Lactobacillus against microbial flora of cervicovaginal infections

    PubMed Central

    Dasari, Subramanyam; Shouri, Raju Naidu Devanaboyaina; Wudayagiri, Rajendra; Valluru, Lokanatha

    2014-01-01

    Objective To assess the probiotic nature of Lactobacillus in preventing cervical pathogens by studying the effectiveness of antimicrobial activity against vaginal pathogens. Methods Lactobacilli were isolated from healthy vaginal swabs on selective media and different pathogenic bacteria were isolated by using different selective media. The Lactobacillus strains were tested for the production of hydrogen peroxide and antimicrobial compounds along with probiotic properties. Results Of the 10 isolated Lactobacillus strains, strain 1, 3 and 6 are high hydrogen peroxide producers and the rest were low producers. Results of pH and amines tests indicated that pH increased with fishy odour in the vaginal fluids of cervicovaginal infection patients when compared with vaginal fluids of healthy persons. The isolates were found to be facultative anaerobic, Gram-positive, non-spore-forming, non-capsule forming and catalase-negative bacilli. The results of antimicrobial activity of compounds indicated that 280 and 140 µg/mL was the minimum concentration to inhibit the growth of both pathogens and test organisms respectively. Conclusions The results demonstrated that Lactobacillus producing antimicrobial compounds inhibits the growth of cervical pathogens, revealing that the hypothesis of preventing vaginal infection by administering probiotic organisms has a great appeal to patients, which colonize the vagina to help, restore and maintain healthy vagina.

  9. Alanine-Scanning Mutational Analysis of Durancin GL Reveals Residues Important for Its Antimicrobial Activity.

    PubMed

    Ju, Xingrong; Chen, Xinquan; Du, Lihui; Wu, Xueyou; Liu, Fang; Yuan, Jian

    2015-07-22

    Durancin GL is a novel class IIa bacteriocin with 43 residues produced by Enterococcus durans 41D. This bacteriocin demonstrates narrow inhibition spectrum and potent antimicrobial activity against several Listeria monocytogenes strains, including nisin-resistant L. monocytogenes NR30. A systematic alanine-scanning mutational analysis with site-directed mutagenesis was performed to analyze durancin GL residues important for antimicrobial activity and specificity. Results showed that three mutations lost their antimicrobial activity, ten mutations demonstrated a decreased effect on the activity, and seven mutations exhibited relatively high activity. With regard to inhibitory spectrum, four mutants demonstrated a narrower antimicrobial spectrum than wild-type durancin GL. Another four mutants displayed a broader target cell spectrum and increased potency relative to wild-type durancin GL. These findings broaden our understanding of durancin GL residues important for its antimicrobial activity and contribute to future rational design of variants with increased potency. PMID:26168032

  10. [Antimicrobial activity of stable silver nanoparticles of a certain size].

    PubMed

    Mukha, Iu P; Eremenko, A M; Smirnova, N P; Mikhienkova, A I; Korchak, G I; Gorchev, V F; Chunikhin, A Iu

    2013-01-01

    Conditions for obtaining stable silver nanoparticles smaller than 10 nm were developed using a binary stabilizer polyvinylpyrrolidone/sodium dodecylsulphate in optimal ratio. Optical spectra, morphology and dependence of size of the nanoparticles on the amount of reducing agent were studied. Colloidal solutions of nanosilver showed a high bactericidal activity against strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, and fungicidal activity against Candida albicans. The mechanism of action of nanosized silver on microbial cell was examined by laser scanning confocal microscope using fluorescent label. First step of antimicrobial effect on microorganisms was membrane damage and penetration of silver nanoparticles into the cell. Prolonged stability of nanoparticles and their antimicrobial activity over the past two years were showed. PMID:23795483

  11. Green synthesis of biogenic silver nanomaterials using Raphanus sativus extract, effects of stabilizers on the morphology, and their antimicrobial activities.

    PubMed

    Khan, Mohammad Naved; Khan, Tabrez Alam; Khan, Zaheer; Al-Thabaiti, Shaeel Ahmed

    2015-12-01

    The present study explores the reducing and capping potentials of aqueous Raphanus sativus root extract for the synthesis of silver nanomaterials for the first time in the absence and presence of two stabilizers, namely, water-soluble starch and cetyltrimethylammonium bromide (CTAB). The surface properties of silver nanoparticles (AgNPs) were determined by dynamic light scattering (DLS), transmission electron microscopy (TEM), energy dispersion X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) techniques. The mean size of AgNPs, ranging from 3.2 to 6.0 nm, could be facilely controlled by merely varying the initial [extract], [CTAB], [starch], and [Ag(+)] ions. The agglomeration number, average number of silver atoms per nanoparticle, and changes in the fermi potentials were calculated and discussed. The AgNPs were evaluated for their antimicrobial activities against different pathogenic organisms. The inhibition action was due to the structural changes in the protein cell wall. PMID:26458821

  12. Simultaneous Antibiofilm and Antiviral Activities of an Engineered Antimicrobial Peptide during Virus-Bacterium Coinfection

    PubMed Central

    Melvin, Jeffrey A.; Lashua, Lauren P.; Kiedrowski, Megan R.; Yang, Guanyi; Deslouches, Berthony; Montelaro, Ronald C.

    2016-01-01

    ABSTRACT Antimicrobial-resistant infections are an urgent public health threat, and development of novel antimicrobial therapies has been painstakingly slow. Polymicrobial infections are increasingly recognized as a significant source of severe disease and also contribute to reduced susceptibility to antimicrobials. Chronic infections also are characterized by their ability to resist clearance, which is commonly linked to the development of biofilms that are notorious for antimicrobial resistance. The use of engineered cationic antimicrobial peptides (eCAPs) is attractive due to the slow development of resistance to these fast-acting antimicrobials and their ability to kill multidrug-resistant clinical isolates, key elements for the success of novel antimicrobial agents. Here, we tested the ability of an eCAP, WLBU2, to disrupt recalcitrant Pseudomonas aeruginosa biofilms. WLBU2 was capable of significantly reducing biomass and viability of P. aeruginosa biofilms formed on airway epithelium and maintained activity during viral coinfection, a condition that confers extraordinary levels of antibiotic resistance. Biofilm disruption was achieved in short treatment times by permeabilization of bacterial membranes. Additionally, we observed simultaneous reduction of infectivity of the viral pathogen respiratory syncytial virus (RSV). WLBU2 is notable for its ability to maintain activity across a broad range of physiological conditions and showed negligible toxicity toward the airway epithelium, expanding its potential applications as an antimicrobial therapeutic. IMPORTANCE Antimicrobial-resistant infections are an urgent public health threat, making development of novel antimicrobials able to effectively treat these infections extremely important. Chronic and polymicrobial infections further complicate antimicrobial therapy, often through the development of microbial biofilms. Here, we describe the ability of an engineered antimicrobial peptide to disrupt biofilms

  13. Simultaneous Antibiofilm and Antiviral Activities of an Engineered Antimicrobial Peptide during Virus-Bacterium Coinfection.

    PubMed

    Melvin, Jeffrey A; Lashua, Lauren P; Kiedrowski, Megan R; Yang, Guanyi; Deslouches, Berthony; Montelaro, Ronald C; Bomberger, Jennifer M

    2016-01-01

    Antimicrobial-resistant infections are an urgent public health threat, and development of novel antimicrobial therapies has been painstakingly slow. Polymicrobial infections are increasingly recognized as a significant source of severe disease and also contribute to reduced susceptibility to antimicrobials. Chronic infections also are characterized by their ability to resist clearance, which is commonly linked to the development of biofilms that are notorious for antimicrobial resistance. The use of engineered cationic antimicrobial peptides (eCAPs) is attractive due to the slow development of resistance to these fast-acting antimicrobials and their ability to kill multidrug-resistant clinical isolates, key elements for the success of novel antimicrobial agents. Here, we tested the ability of an eCAP, WLBU2, to disrupt recalcitrant Pseudomonas aeruginosa biofilms. WLBU2 was capable of significantly reducing biomass and viability of P. aeruginosa biofilms formed on airway epithelium and maintained activity during viral coinfection, a condition that confers extraordinary levels of antibiotic resistance. Biofilm disruption was achieved in short treatment times by permeabilization of bacterial membranes. Additionally, we observed simultaneous reduction of infectivity of the viral pathogen respiratory syncytial virus (RSV). WLBU2 is notable for its ability to maintain activity across a broad range of physiological conditions and showed negligible toxicity toward the airway epithelium, expanding its potential applications as an antimicrobial therapeutic. IMPORTANCE Antimicrobial-resistant infections are an urgent public health threat, making development of novel antimicrobials able to effectively treat these infections extremely important. Chronic and polymicrobial infections further complicate antimicrobial therapy, often through the development of microbial biofilms. Here, we describe the ability of an engineered antimicrobial peptide to disrupt biofilms formed by the

  14. Antimicrobial Activity of Nanoemulsion on Cariogenic Planktonic and Biofilm Organisms

    PubMed Central

    Amaechi, Bennett T.; Rawls, H Ralph; Valerie, A Lee

    2011-01-01

    Introduction Nanoemulsions (NE) are a unique class of disinfectants produced by mixing a water immiscible liquid phase into an aqueous phase under high shear forces. NE have antimicrobial properties and are also effective anti-biofilm agents. Materials and Methods The effectiveness of nanoemulsion and its components was determined against Streptococcus mutans and Lactobacillus casei by live/dead staining. In vitro antimicrobial effectiveness of nanoemulsion against planktonic Streptococcus mutans, Lactobacillus casei, Actinomyces viscosus, Candida albicans and mixed culture was determined by a serial dilution technique to obtain minimum inhibitory concentration and minimum bactericidal concentration (MIC/MBC). In addition, efficacy was investigated by kinetics of killing, adherence and biofilm assays. Results Compared to its components, nanoemulsion showed notable antimicrobial activity against biofilm organisms, up to 83.0% kill within 1 min. NE dilutions ranging from 243 to 19683 were effective against planktonic S. mutans, L. casei, A. viscosus, C. albicans and mixed culture of these four strains as shown through MIC/MBC assays. NE showed antimicrobial activity against planktonic cells at high dilutions, confirmed by time kill studies. The level of adhesion on glass surface was reduced by 94.2 to 99.5 % in nanoemulsion treated groups (p < 0.001). 4-day-old S. mutans, L. casei, A. viscosus, C. albicans and mixed cultures biofilms treated with NE showed reductions of bacterial counts with decreasing dilutions (p < 0.001). Conclusion These results suggest that nanoemulsion has effective anti-cariogenic activity against cariogenic microorganisms and may be a useful medication in the prevention of caries. PMID:21807359

  15. Antiendotoxin activity of cationic peptide antimicrobial agents.

    PubMed Central

    Gough, M; Hancock, R E; Kelly, N M

    1996-01-01

    The endotoxin from gram-negative bacteria consists of a molecule lipopolysaccharide (LPS) which can be shed by bacteria during antimicrobial therapy. A resulting syndrome, endotoxic shock, is a leading cause of death in the developed world. Thus, there is great interest in the development of antimicrobial agents which can reverse rather than promote sepsis, especially given the recent disappointing clinical performance of antiendotoxin therapies. We describe here two small cationic peptides, MBI-27 and MBI-28, which have both antiendotoxic and antibacterial activities in vitro and in vivo in animal models. We had previously demonstrated that these peptides bind to LPS with an affinity equivalent to that of polymyxin B. Consistent with this, the peptides blocked the ability of LPS and intact cells to induce the endotoxic shock mediator, tumor necrosis factor (TNF), upon incubation with the RAW 264.7 murine macrophage cell line. MBI-28 was equivalent to polymyxin B in its ability to block LPS induction of TNF by this cell line, even when added 60 min after the TNF stimulus. Furthermore, MBI-28 offered significant protection in a galactosamine-sensitized mouse model of lethal endotoxic shock. This protection correlated with the ability of MBI-28 to reduce LPS-induced circulating TNF by nearly 90% in this mouse model. Both MBI-27 and MBI-28 demonstrated antibacterial activity against gram-negative bacteria in vitro and in vivo against Pseudomonas aeruginosa infections in neutropenic mice. PMID:8945527

  16. Antimicrobial activities of some Euphorbia species.

    PubMed

    Kirbag, Sevda; Erecevit, Pınar; Zengin, Fikriye; Guvenc, Ayşe Nilay

    2013-01-01

    In this study, the antimicrobial activities of methanolic extracts and latex of some Euphorbia species used for medical purposes in Turkey were investigated. The extracts of Euphorbia aleppica L., Euphorbia szovitsii Fisch.&Mey. var. harputensis Aznav. ex M. S. Khan, Euphorbia falcata L. sub. falcata var. falcata, Euphorbia denticulata Lam., Euphorbia macroclada Boiss., Euphorbia cheiradenia Boiss.&Hohen, Euphorbia virgata Waldst.&Kit., Euphorbia petiolata Banks&Sol. were prepared with methanol. The antimicrobial activities of these extracts were examined on test microorganisms as follows: Staphylococcus aureus COWAN 1, Bacillus megaterium DSM 32, Proteus vulgaris FMC 1, Klebsiella pneumonia FMC 5, Escherichia coli ATCC 25922, Pseudomonas aeruginosa DSM 50071, Candida albicans FMC 17, Candida glabrata ATCC 66032, Epidermophyton sp. and Trichophyton sp. by the disc diffusion methods and well agar method. The MIC values of extracts were determined according to the broth microdulitions method. Results indicated that extracts of Euphorbia species inhibited the growth of tested microorganisms in the different ratio. Also, the MIC values of extracts were determined as 31,2-1000 µg. PMID:24311840

  17. Antimicrobial activity of endophytic fungi isolated from Swietenia macrophylla leaves.

    PubMed

    Ibrahim, Darah; Lee, Chong Chai; Sheh-Hong, Lim

    2014-02-01

    The endophytic fungi isolated from leaves of Swietenia macrophylla of different ages were examined for antimicrobial activity. The agar plug diffusion assay was used for primary screening, followed by the disc diffusion method. A total of 461 filamentous endophytic fungi were isolated and cultured to examine their antimicrobial properties. In the primary screen, 315 isolates (68.3%) exhibited activity against at least one of the test pathogenic microorganisms. The percentage of isolates exhibiting antimicrobial activity increased with leaf age. Endophytic fungal assemblages, as well as those isolates exhibiting antimicrobial properties appeared to increase with leaf age. The main antimicrobial compounds were produced extracellularly by the endophytic fungi. The results suggest that healthy leaves at older stages of growth can be a potential source for the isolation of endophytic fungi with antimicrobial properties. PMID:24689302

  18. Quaternized Chitosan as an Antimicrobial Agent: Antimicrobial Activity, Mechanism of Action and Biomedical Applications in Orthopedics

    PubMed Central

    Tan, Honglue; Ma, Rui; Lin, Chucheng; Liu, Ziwei; Tang, Tingting

    2013-01-01

    Chitosan (CS) is a linear polysaccharide with good biodegradability, biocompatibility and antimicrobial activity, which makes it potentially useful for biomedical applications, including an antimicrobial agent either alone or blended with other polymers. However, the poor solubility of CS in most solvents at neutral or high pH substantially limits its use. Quaternary ammonium CS, which was prepared by introducing a quaternary ammonium group on a dissociative hydroxyl group or amino group of the CS, exhibited improved water solubility and stronger antibacterial activity relative to CS over an entire range of pH values; thus, this quaternary modification increases the potential biomedical applications of CS in the field of anti-infection. This review discusses the current findings on the antimicrobial properties of quaternized CS synthesized using different methods and the mechanisms of its antimicrobial actions. The potential antimicrobial applications in the orthopedic field and perspectives regarding future studies in this field are also considered. PMID:23325051

  19. The antiviral and antimicrobial activities of licorice, a widely-used Chinese herb

    PubMed Central

    Wang, Liqiang; Yang, Rui; Yuan, Bochuan; Liu, Ying; Liu, Chunsheng

    2015-01-01

    Licorice is a common herb which has been used in traditional Chinese medicine for centuries. More than 20 triterpenoids and nearly 300 flavonoids have been isolated from licorice. Recent studies have shown that these metabolites possess many pharmacological activities, such as antiviral, antimicrobial, anti-inflammatory, antitumor and other activities. This paper provides a summary of the antiviral and antimicrobial activities of licorice. The active components and the possible mechanisms for these activities are summarized in detail. This review will be helpful for the further studies of licorice for its potential therapeutic effects as an antiviral or an antimicrobial agent. PMID:26579460

  20. Antityrosinase and antimicrobial activities from Thai medicinal plants.

    PubMed

    Dej-Adisai, Sukanya; Meechai, Imron; Puripattanavong, Jindaporn; Kummee, Sopa

    2014-04-01

    Various dermatological disorders and microbial skin infection can cause hyperpigmentation. Therefore, screenings for whitening and antimicrobial agents from Thai medicinal plants have been of research interest. Seventy-seven ethanol plant extracts were investigated for antityrosinase activity, eleven samples showed the tyrosinase inhibition more than 50 % were further preliminary screening for antimicrobial activity by agar disc diffusion and broth micro-dilution methods. Artocarpus integer (Thunb.) Merr. (Moraceae) root extract, which showed the potential of tyrosinase inhibition with 90.57 ± 2.93 % and antimicrobial activity against Staphylococcus aureus, S. epidermidis, Propionibacterium acnes and Trichophyton mentagophytes with inhibition zone as 9.10 ± 0.00, 10.67 ± 0.09, 15.25 ± 0.05 and 6.60 ± 0.17 mm, respectively was selected for phytochemical investigation. Three pure compounds were isolated as artocarpin, cudraflavone C and artocarpanone. And artocarpanone exhibited anti-tyrosinase effect; artocarpin and cudraflavone C also showed the potential of antibacterial activity against S. aureus, S. epidermidis and P. acnes with MIC at 2, 4 and 2 μg/ml, respectively and MBC at 32 μg/ml for these bacteria. So, these pure compounds are interesting for further study in order to provide possibilities of new whitening and antibacterial development. This will be the first report of phytochemical investigation of A. integer root. PMID:23835832

  1. Antimicrobial activity of grapefruit seed and pulp ethanolic extract.

    PubMed

    Cvetnić, Zdenka; Vladimir-Knezević, Sanda

    2004-09-01

    Antibacterial and antifungal activity of ethanolic extract of grapefruit (Citrus paradisi Macf., Rutaceae) seed and pulp was examined against 20 bacterial and 10 yeast strains. The level of antimicrobial effects was established using an in vitro agar assay and standard broth dilution susceptibility test. The contents of 3.92% of total polyphenols and 0.11% of flavonoids were determined spectrometrically in crude ethanolic extract. The presence of flavanones naringin and hesperidin in the extract was confirmed by TLC analysis. Ethanolic extract exibited the strongest antimicrobial effect against Salmonella enteritidis (MIC 2.06%, m/V). Other tested bacteria and yeasts were sensitive to extract concentrations ranging from 4.13% to 16.50% (m/V). PMID:15610620

  2. Antimicrobial activity of Caesalpinia pulcherrima, Euphorbia hirta and Asystasia gangeticum.

    PubMed

    Sudhakar, M; Rao, Ch V; Rao, P M; Raju, D B; Venkateswarlu, Y

    2006-07-01

    The ethanolic extracts of the dry fruits of Caesalpinia pulcherrima, aerial parts of Euphorbia hirta and flowers of Asystasia gangeticum were tested for antimicrobial activity. The three plants exhibited a broad spectrum of antimicrobial activity, particularly against Escherichia coli (enteropathogen), Proteus vulgaris, Pseudomonas aeruginosa and Staphylococcus aureus. PMID:16730921

  3. Effects of Allspice, Cinnamon, and Clove Bud Essential Oils in Edible Apple Films on Physical Properties and Antimicrobial Activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The results of the present study show that allspice, cinnamon and clove bud essential oils can be used to prepare apple-based antimicrobial edible films with good physical properties for food applications by both direct contact and indirectly by vapors emanating from the films. Application of the a...

  4. Composition and Antimicrobial Activity of Euphrasia rostkoviana Hayne Essential Oil.

    PubMed

    Novy, Pavel; Davidova, Hana; Serrano-Rojero, Cecilia Suqued; Rondevaldova, Johana; Pulkrabek, Josef; Kokoska, Ladislav

    2015-01-01

    Eyebright, Euphrasia rostkoviana Hayne (Scrophulariaceae), is a medicinal plant traditionally used in Europe for the treatment of various health disorders, especially as eyewash to treat eye ailments such as conjunctivitis and blepharitis that can be associated with bacterial infections. Some Euphrasia species have been previously reported to contain essential oil. However, the composition and bioactivity of E. rostkoviana oil are unknown. Therefore, in this study, we investigated the chemical composition and antimicrobial activity of the eyebright essential oil against some organisms associated with eye infections: Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, and Candida albicans. GC-MS analysis revealed more than 70 constituents, with n-hexadecanoic acid (18.47%) as the main constituent followed by thymol (7.97%), myristic acid (4.71%), linalool (4.65%), and anethole (4.09%). The essential oil showed antimicrobial effect against all organisms tested with the exception of P. aeruginosa. The best activity was observed against all Gram-positive bacteria tested with the minimum inhibitory concentrations of 512 µg/mL. This is the first report on the chemical composition of E. rostkoviana essential oil and its antimicrobial activity. PMID:26000025

  5. Composition and Antimicrobial Activity of Euphrasia rostkoviana Hayne Essential Oil

    PubMed Central

    Novy, Pavel; Davidova, Hana; Serrano-Rojero, Cecilia Suqued; Rondevaldova, Johana; Pulkrabek, Josef

    2015-01-01

    Eyebright, Euphrasia rostkoviana Hayne (Scrophulariaceae), is a medicinal plant traditionally used in Europe for the treatment of various health disorders, especially as eyewash to treat eye ailments such as conjunctivitis and blepharitis that can be associated with bacterial infections. Some Euphrasia species have been previously reported to contain essential oil. However, the composition and bioactivity of E. rostkoviana oil are unknown. Therefore, in this study, we investigated the chemical composition and antimicrobial activity of the eyebright essential oil against some organisms associated with eye infections: Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, and Candida albicans. GC-MS analysis revealed more than 70 constituents, with n-hexadecanoic acid (18.47%) as the main constituent followed by thymol (7.97%), myristic acid (4.71%), linalool (4.65%), and anethole (4.09%). The essential oil showed antimicrobial effect against all organisms tested with the exception of P. aeruginosa. The best activity was observed against all Gram-positive bacteria tested with the minimum inhibitory concentrations of 512 µg/mL. This is the first report on the chemical composition of E. rostkoviana essential oil and its antimicrobial activity. PMID:26000025

  6. Antimicrobial activity of toothpastes containing natural extracts, chlorhexidine or triclosan.

    PubMed

    De Rossi, Andiara; Ferreira, Danielly Cunha Araújo; da Silva, Raquel Assed Bezerra; de Queiroz, Alexandra Mussolino; da Silva, Léa Assed Bezerra; Nelson-Filho, Paulo

    2014-01-01

    The objective of this in vitro study was to evaluate the antimicrobial effect of toothpastes containing natural extracts, chlorhexidine or triclosan. The effectiveness of toothpastes containing natural extracts (Parodontax®), 0.12% chlorhexidine (Cariax®), 0.3% triclosan (Sanogil®) or fluoride (Sorriso®, control) was evaluated against yeasts, Gram-positive and Gram-negative bacteria using the disk diffusion method. Water was used as a control. Disks impregnated with the toothpastes were placed in Petri dishes containing culture media inoculated with 23 indicative microorganisms by the pour plate method. After incubation, the inhibition growth halos were measured and statistical analyses (α=0.05) were performed. The results indicated that all formulations, except for conventional toothpaste (Sorriso®), showed antimicrobial activity against Gram-positive bacteria and yeasts. The toothpaste containing natural extracts (Parodontax®) was the only product able to inhibit the growth of Pseudomonas aeruginosa. The toothpastes containing chlorhexidine, triclosan or natural extracts presented antimicrobial activity against Gram-positive bacteria and yeasts. PMID:25252251

  7. Spectroscopic characterization of the effect of gamma radiation on the physical parameters of biosynthesized silver/chitosan nano-particles and their antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Osman, Mohamed E.; Eid, May M.; Khattab, Om kolthoum H.; El-Hallouty, Salwa M.; El-Marakby, Seham M.; Mahmoud, Doaa A.

    2015-09-01

    Studying the effect of pH on the biosynthesis of silver/chitosan nanoparticles (Ag/CS NPs) using Aspergillus deflectus and Penicillium pinophilum as reducing agents, showed very weak surface plasmon resonance (SPR) of Ag/CS NPs at certain pH. In this paper, the effect of irradiation on the synthesis of Ag/CS at non-optimum pH was evaluated and thereby, the antimicrobial effect of the biosynthesized Ag/CS NPs. The SPR of the AgNPs was analyzed by UV-visible spectroscopy. The active groups responsible for the reduction and capping of the AgNPs were analyzed by Fourier transform infrared (FTIR), and their shape and size were determined via high resolution transmission electron microscopy (HRTEM) and the dynamic light scattering (DLS) technique. UV/Visible spectroscopy confirmed the appearance of AgNPs’ SPR. Additionally, the FTIR spectroscopy confirmed the Ag/CS NP formation. Data also revealed that increasing both the pH and irradiation dose resulted in a decrease of the Ag/CS NPs’ size. DLS and HRTEM results showed that the best pH for biosynthesis of Ag/Cs is 7.5 at 50 kGy considering the particle size and crystallinity. Also, pH 8.5 gave the best antimicrobial activity of the Ag/CS NPs from Penicillium against both S. aureus and E. coli, while 8.5 and 7.5 were the best in the same order, for Ag/CS from Aspergillus.

  8. Effects of Egg Shell Membrane Hydrolysates on Anti-Inflammatory, Anti-Wrinkle, Anti-Microbial Activity and Moisture-Protection.

    PubMed

    Yoo, Jinhee; Park, Kimoon; Yoo, Youngji; Kim, Jongkeun; Yang, Heejin; Shin, Youngjae

    2014-01-01

    This study was conducted to examine the effects of eggshell membrane hydrolysates (ESMH) on the anti-inflammatory, anti-wrinkle, anti-microbial activity, and moisture-protection for cosmetic use. Whole ESMH (before fractionation), and fraction I (>10 kDa), fraction II (3-10 kDa), and fraction III (<3 kDa) of the hydrolysates were assessed in this experiment. As lipopolysaccharide (LPS) and IFN-γ caused the inflammation on Raw264.7 cell, whole ESMH and fraction I showed to be effective in inhibiting the induction of cell inflammation depending on the concentration, and also showed outstanding effect to suppress the skin inflammation. Fraction I inhibited collagenase and elastase activities to a greater extent than the other fractions, while all fractions had antibiotic effects at concentrations of 10 mg/disc and 20 mg/disc. In addition, it showed the moisture protection effects of skin on the holding amount and losing amount of moisture in upper-inner arm of the human body with a relatively low loss rate in skin, which confirmed that the hydrolyzed fractions of ESM helps to form the superior protective layer of moisture. It was concluded that ESMH fractions with different molecular weights, especially the 10 kDa fraction, have anti-lipopolysaccharide, anti-IFN-γ-induced inflammation, anti- collagenase and elastase activities, and thus can be used as a cosmetic agent to protect skin. PMID:26760742

  9. Effects of Egg Shell Membrane Hydrolysates on Anti-Inflammatory, Anti-Wrinkle, Anti-Microbial Activity and Moisture-Protection

    PubMed Central

    Yoo, Jinhee; Park, Kimoon; Yoo, Youngji; Kim, Jongkeun; Yang, Heejin; Shin, Youngjae

    2014-01-01

    This study was conducted to examine the effects of eggshell membrane hydrolysates (ESMH) on the anti-inflammatory, anti-wrinkle, anti-microbial activity, and moisture-protection for cosmetic use. Whole ESMH (before fractionation), and fraction I (>10 kDa), fraction II (3-10 kDa), and fraction III (<3 kDa) of the hydrolysates were assessed in this experiment. As lipopolysaccharide (LPS) and IFN-γ caused the inflammation on Raw264.7 cell, whole ESMH and fraction I showed to be effective in inhibiting the induction of cell inflammation depending on the concentration, and also showed outstanding effect to suppress the skin inflammation. Fraction I inhibited collagenase and elastase activities to a greater extent than the other fractions, while all fractions had antibiotic effects at concentrations of 10 mg/disc and 20 mg/disc. In addition, it showed the moisture protection effects of skin on the holding amount and losing amount of moisture in upper-inner arm of the human body with a relatively low loss rate in skin, which confirmed that the hydrolyzed fractions of ESM helps to form the superior protective layer of moisture. It was concluded that ESMH fractions with different molecular weights, especially the 10 kDa fraction, have anti-lipopolysaccharide, anti-IFN-γ-induced inflammation, anti- collagenase and elastase activities, and thus can be used as a cosmetic agent to protect skin. PMID:26760742

  10. Novel Antimicrobial Peptides with High Anticancer Activity and Selectivity

    PubMed Central

    Chen, Kuan-Hao; Yu, Hui-Yuan; Chih, Ya-Han; Cheng, Hsi-Tsung; Chou, Yu-Ting; Cheng, Jya-Wei

    2015-01-01

    We describe a strategy to boost anticancer activity and reduce normal cell toxicity of short antimicrobial peptides by adding positive charge amino acids and non-nature bulky amino acid β-naphthylalanine residues to their termini. Among the designed peptides, K4R2-Nal2-S1 displayed better salt resistance and less toxicity to hRBCs and human fibroblast than Nal2-S1 and K6-Nal2-S1. Fluorescence microscopic studies indicated that the FITC-labeled K4R2-Nal2-S1 preferentially binds cancer cells and causes apoptotic cell death. Moreover, a significant inhibition in human lung tumor growth was observed in the xenograft mice treated with K4R2-Nal2-S1. Our strategy provides new opportunities in the development of highly effective and selective antimicrobial and anticancer peptide-based therapeutics. PMID:25970292

  11. Biologically Active and Antimicrobial Peptides from Plants

    PubMed Central

    Salas, Carlos E.; Badillo-Corona, Jesus A.; Ramírez-Sotelo, Guadalupe; Oliver-Salvador, Carmen

    2015-01-01

    Bioactive peptides are part of an innate response elicited by most living forms. In plants, they are produced ubiquitously in roots, seeds, flowers, stems, and leaves, highlighting their physiological importance. While most of the bioactive peptides produced in plants possess microbicide properties, there is evidence that they are also involved in cellular signaling. Structurally, there is an overall similarity when comparing them with those derived from animal or insect sources. The biological action of bioactive peptides initiates with the binding to the target membrane followed in most cases by membrane permeabilization and rupture. Here we present an overview of what is currently known about bioactive peptides from plants, focusing on their antimicrobial activity and their role in the plant signaling network and offering perspectives on their potential application. PMID:25815307

  12. Antimicrobial activity of natural Respitol-B and its main components against poultry microorganisms.

    PubMed

    Mahboubi, Mohaddese; Kazempour, Nastaran; Valian, Mahdi

    2013-10-01

    Poultries are infected to different kinds of microbial infections during their growth. For prevent of these diseases, many farmers use the synthetic antimicrobial agents. Whereas, the poultries participate in food cycle of human, the residues of these agents enter in human and cause many undesired side effects. In this study, the antimicrobial activity of Respitol-B and its main components (eucalyptus oil and menthol) was evaluated on different kinds of microorganisms including gram positive, gram negative bacteria, yeast and fungi in vitro conditions by disc diffusion and micro broth dilution assays. The gram positive bacteria, yeast and fungi is more sensitive than Gram negative ones to Respitol-B. Pseudomonas aeruginosa, Escherichia coli and Salmonella typhimurium is less sensitive to Respitol-B. Evaluation of menthol and eucalyptus oil for their antimicrobial activities exhibited that the antimicrobial activity of menthol is higher than that of eucalyptus oil. Eucalyptus oil had the best effect on Vibrio cholerae, Staphylococcus aureus, Aspergillus flavus but had no effect on others. The antimicrobial activity of menthol is observable and its presence in Respitol-B enhances the antimicrobial activity of Respitol-B. Respitol-B as a 100% herbal drug has antimicrobial effect and can be used as alternative therapy for preventing and controlling of infections. PMID:24502173

  13. Mechanisms of the Antimicrobial Activities of Graphene Materials.

    PubMed

    Zou, Xuefeng; Zhang, Li; Wang, Zhaojun; Luo, Yang

    2016-02-24

    A thorough understanding of the antimicrobial mechanisms of graphene materials (GMs) is critical to the manipulation of highly efficient antimicrobial nanomaterials for future biomedical applications. Here we review the most recent studies of GM-mediated antimicrobial properties. This review covers the physicochemical properties of GMs, experimental surroundings, and selected microorganisms as well as the interaction between GMs and selected microorganisms to explore controversial antimicrobial activities. Finally, we rationally analyze the strengths and weaknesses of the proposed mechanisms and provide new insights into the remaining challenges and perspectives for future studies. PMID:26824139

  14. Effect of postharvest UV-C treatment on the bacterial diversity of Ataulfo mangoes by PCR-DGGE, survival of E. coli and antimicrobial activity

    PubMed Central

    Fernández-Suárez, Rocío; Ramírez-Villatoro, Guadalupe; Díaz-Ruiz, Gloria; Eslava, Carlos; Calderón, Montserrat; Navarro-Ocaña, Arturo; Trejo-Márquez, Andrea; Wacher, Carmen

    2013-01-01

    Since Mexico is the second largest exporter of mangoes, its safety assurance is essential. Research in microbial ecology and knowledge of complex interactions among microbes must be better understood to achieve maximal control of pathogens. Therefore, we investigated the effect of UV-C treatments on bacterial diversity of the Ataulfo mangoes surface using PCR-DGGE analysis of variable region V3 of 16S rRNA genes, and the survival of E. coli, by plate counting. The UV-C irradiation reduced the microbial load on the surface of mangoes immediately after treatment and the structure of bacterial communities was modified during storage. We identified the key members of the bacterial communities on the surface of fruits, predominating Enterobacter genus. Genera as Lactococcus and Pantoea were only detected on the surface of non-treated (control) mangoes. This could indicate that these genera were affected by the UV-C treatment. On the other hand, the treatment did not have a significant effect on survival of E. coli. However, genera that have been recognized as antagonists against foodborne pathogens were identified in the bands patterns. Also, phenolic compounds were determined by HPLC and antimicrobial activity was assayed according to the agar diffusion method. The main phenolic compounds were chlorogenic, gallic, and caffeic acids. Mango peel methanol extracts (UV-C treated and control mangoes) showed antimicrobial activity against strains previously isolated from mango, detecting significant differences (P < 0.05) among treated and control mangoes after 4 and 12 days of storage. Ps. fluorescens and Ps. stutszeri were the most sensitive. PMID:23761788

  15. Antimicrobial evaluation of new metallic complexes with xylitol active against P. aeruginosa and C. albicans: MIC determination, post-agent effect and Zn-uptake.

    PubMed

    Santi, E; Facchin, G; Faccio, R; Barroso, R P; Costa-Filho, A J; Borthagaray, G; Torre, M H

    2016-02-01

    Xylitol (xylH5) is metabolized via the pentose pathway in humans, but it is unsuitable as an energy source for many microorganisms where it produces a xylitol-induced growth inhibition and disturbance in protein synthesis. For this reason, xylitol is used in the prophylaxis of several infections. In the search of better antimicrobial agents, new copper and zinc complexes with xylitol were synthesized and characterized by analytical and spectrosco pic methods: Na2[Cu3(xylH−4)2]·NaCl·4.5H2O (Cu-xyl) and [Zn4(xylH−4)2(H2O)2]·NaCl·3H2O (Zn-xyl). Both copper and zinc complexes presented higher MIC against Pseudomona aeruginosa than the free xylitol while two different behaviors were found against Candida albicans depending on the complex. The growth curves showed that Cu-xyl presented lower activity than the free ligand during all the studied period. In the case of Znxyl the growth curves showed that the inhibition of the microorganism growth in the first stage was equivalent to that of xylitol but in the second stage (after 18 h) Zn-xyl inhibited more. Besides, the PAE (post agent effect)obtained for Zn-xyl and xyl showed that the recovery from the damage of microbial cells had a delay of 14 and 13 h respectively. This behavior could be useful in prophylaxis treatments for infectious diseases where it is important that the antimicrobial effect lasts longer. With the aim to understand the microbiological activities the analysis of the particle size, lipophilicity and Zn uptake was performed. PMID:26619097

  16. Prediction of Antimicrobial Activity of Synthetic Peptides by a Decision Tree Model

    PubMed Central

    Lira, Felipe; Perez, Pedro S.; Baranauskas, José A.

    2013-01-01

    Antimicrobial resistance is a persistent problem in the public health sphere. However, recent attempts to find effective substitutes to combat infections have been directed at identifying natural antimicrobial peptides in order to circumvent resistance to commercial antibiotics. This study describes the development of synthetic peptides with antimicrobial activity, created in silico by site-directed mutation modeling using wild-type peptides as scaffolds for these mutations. Fragments of antimicrobial peptides were used for modeling with molecular modeling computational tools. To analyze these peptides, a decision tree model, which indicated the action range of peptides on the types of microorganisms on which they can exercise biological activity, was created. The decision tree model was processed using physicochemistry properties from known antimicrobial peptides available at the Antimicrobial Peptide Database (APD). The two most promising peptides were synthesized, and antimicrobial assays showed inhibitory activity against Gram-positive and Gram-negative bacteria. Colossomin C and colossomin D were the most inhibitory peptides at 5 μg/ml against Staphylococcus aureus and Escherichia coli. The methods described in this work and the results obtained are useful for the identification and development of new compounds with antimicrobial activity through the use of computational tools. PMID:23455341

  17. Antimicrobial activities against periodontopathic bacteria of Pittosporum tobira and its active compound.

    PubMed

    Oh, Jung-Hyun; Jeong, Yong Joon; Koo, Hyun Jung; Park, Dae Won; Kang, Se Chan; Khoa, Hoang Viet Bach; Le, Le Ba; Cho, Joon Hyeong; Lee, Jin-Yong

    2014-01-01

    The study of medicinal plants for treatment of periodontitis is of great value to establish their efficacy as sources of new antimicrobial drugs. Five hundred and fifty eight Korean local plant extracts were screened for antibacterial activity against representative periodontopathic bacteria such as Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum. Among the various medicinal plants, the alcohol extract of Pittosporum tobira, which significantly exhibited antibacterial effect for all tested strains, showed the highest activity in the antimicrobial assays. NMR analyses revealed that R1-barrigenol, a triterpene sapogenin, was the most effective compound in P. tobira. These results demonstrated that P. tobira possesses antimicrobial properties and would be beneficial for the prevention and treatment of periodontitis. PMID:24662076

  18. Antimicrobial activity of chicken NK-lysin against Eimeria sporozoites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NK-lysin is an antimicrobial and antitumor polypeptide that is considered to play an important role during innate immunity. Chicken NK-lysin is a member of the saposin-like protein family and exhibits potent antitumor cell activity. To evaluate the antimicrobial properties of chicken NK-lysin, we ex...

  19. Activity of abundant antimicrobials of the human airway.

    PubMed

    Travis, S M; Conway, B A; Zabner, J; Smith, J J; Anderson, N N; Singh, P K; Greenberg, E P; Welsh, M J

    1999-05-01

    Human airways produce several antimicrobial factors; the most abundant are lysozyme and lactoferrin. Despite their likely importance in preventing infection, and their possible key role in the pathogenesis of cystic fibrosis (CF), we know little about their antibacterial activity in the context of the CF airway. We found that abundant airway antimicrobial factors kill common CF pathogens, although Burkholderia was relatively resistant. To study the antibacterial activity, we developed a rapid, sensitive, and quantitative in vitro luminescence assay. Because NaCl concentrations may be elevated in CF airway surface liquid, we tested the effect of salt on antibacterial activity. Activity of individual factors and of airway lavage fluid was inhibited by high ionic strength, and it was particularly sensitive to divalent cations. However, it was not inhibited by nonionic osmolytes and thus did not require hypotonic liquid. The inhibition by ionic strength could be partially compensated by increased concentrations of antibacterial factors, thus there was no one unique salt concentration for inhibition. CF airway secretions also contain abundant mucin and elastase; however, these had no effect on antibacterial activity of lysozyme, lactoferrin, or airway lavage fluids. When studied at low NaCl concentrations, CF and non-CF airway lavage fluids contained similar levels of antibacterial activity. These results suggest approaches toward developing treatments aimed at preventing or reducing airway infections in individuals with CF. PMID:10226057

  20. Antimicrobial use in swine production and its effect on the swine gut microbiota and antimicrobial resistance.

    PubMed

    Holman, Devin B; Chénier, Martin R

    2015-11-01

    Antimicrobials have been used in swine production at subtherapeutic levels since the early 1950s to increase feed efficiency and promote growth. In North America, a number of antimicrobials are available for use in swine. However, the continuous administration of subtherapeutic, low concentrations of antimicrobials to pigs also provides selective pressure for antimicrobial-resistant bacteria and resistance determinants. For this reason, subtherapeutic antimicrobial use in livestock remains a source of controversy and concern. The swine gut microbiota demonstrates a number of changes in response to antimicrobial administration depending on the dosage, duration of treatment, age of the pigs, and gut location that is sampled. Both culture-independent and -dependent studies have also shown that the swine gut microbiota contains a large number of antimicrobial resistance determinants even in the absence of antimicrobial exposure. Heavy metals, such as zinc and copper, which are often added at relatively high doses to swine feed, may also play a role in maintaining antimicrobial resistance and in the stability of the swine gut microbiota. This review focuses on the use of antimicrobials in swine production, with an emphasis on the North American regulatory context, and their effect on the swine gut microbiota and on antimicrobial resistance determinants in the gut microbiota. PMID:26414105

  1. Studies on Anticancer Activities of Antimicrobial Peptides

    PubMed Central

    Hoskin, David W.; Ramamoorthy, Ayyalusamy

    2008-01-01

    In spite of great advances in cancer therapy, there is considerable current interest in developing anticancer agents with a new mode of action because of the development of resistance by cancer cells towards current anticancer drugs. A growing number of studies have shown that some of the cationic antimicrobial peptides (AMPs), which are toxic to bacteria but not to normal mammalian cells, exhibit a broad spectrum of cytotoxic activity against cancer cells. Such studies have considerably enhanced the significance of AMPs, both synthetic and from natural sources, which have been of importance both for an increased understanding of the immune system and for their potential as clinical antibiotics. The electrostatic attraction between the negatively charged components of bacterial and cancer cells and the positively charged AMPs is believed to play a major role in the strong binding and selective disruption of bacterial and cancer cell membranes, respectively. However, it is unclear why some host defense peptides are able to kill cancer cells when others do not. In addition, it is not clear whether the molecular mechanism(s) underlying the antibacterial and anticancer activities of AMPs are the same or different. In this article, we review various studies on different AMPs that exhibit cytotoxic activity against cancer cells. The suitability of cancer cell-targeting AMPs as cancer therapeutics is also discussed. PMID:18078805

  2. Antimicrobial activity of fermented Theobroma cacao pod husk extract.

    PubMed

    Santos, R X; Oliveira, D A; Sodré, G A; Gosmann, G; Brendel, M; Pungartnik, C

    2014-01-01

    Theobroma cacao L. contains more than 500 different chemical compounds some of which have been traditionally used for their antioxidant, anti-carcinogenic, immunomodulatory, vasodilatory, analgesic, and antimicrobial activities. Spontaneous aerobic fermentation of cacao husks yields a crude husk extract (CHE) with antimicrobial activity. CHE was fractioned by solvent partition with polar solvent extraction or by silica gel chromatography and a total of 12 sub-fractions were analyzed for chemical composition and bioactivity. CHE was effective against the yeast Saccharomyces cerevisiae and the basidiomycete Moniliophthora perniciosa. Antibacterial activity was determined using 6 strains: Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus subtilis (Gram-positive) and Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella choleraesuis (Gram-negative). At doses up to 10 mg/mL, CHE was not effective against the Gram-positive bacteria tested but against medically important P. aeruginosa and S. choleraesuis with a minimum inhibitory concentration (MIC) of 5.0 mg/mL. Sub-fractions varied widely in activity and strongest antibacterial activity was seen with CHE8 against S. choleraesuis (MIC of 1.0 mg/mL) and CHE9 against S. epidermidis (MIC of 2.5 mg/mL). All bioactive CHE fractions contained phenols, steroids, or terpenes, but no saponins. Fraction CHE9 contained flavonoids, phenolics, steroids, and terpenes, amino acids, and alkaloids, while CHE12 had the same compounds but lacked flavonoids. PMID:25299086

  3. Antidiarrhoeal and antimicrobial activity of Calpurnia aurea leaf extract

    PubMed Central

    2013-01-01

    Background In Ethiopia, Calpurnia aurea is used for the treatment of syphilis, malaria, rabies, diabetes, hypertension, diarrhoea, leishmaniasis, trachoma, elephantiasis, fungal diseases and different swellings. However, despite its traditional usage as an antidiarrhoeal and antimicrobial agent, there is limited or no information regarding its effectiveness and mode of action in diarrhoea which may be caused by Shigella flexneri, Staphylococcus aureus, Escherichia coli and Salmonella typhi. Hence, we evaluated the 80% methanol (MeOH) extract of dried and powdered leaves of C. aurea for its antidiarrhoeal and antimicrobial activities. Methods Swiss albino mice of either sex were divided into five groups (five/group): Group I served as control and received vehicle (1% Tween 80) at a dose of 10 ml/kg orally; Group II served as standard and received loperamide at the dose of 3 mg/kg orally; Groups III, IV and V served as test groups and received the 80% MeOH leaf extract of C. aurea at doses of 100, 200 and 400 mg/kg orally, respectively. Diarrhoea was induced by oral administration of 0.5 ml castor oil to each mouse, 1 h after the above treatments. During an observation period of 4 h, time of onset of diarrhea, total number of faecal output (frequency of defecation) and weight of faeces excreted by the animals were recorded. Data were analyzed using one way analysis of variance followed by Tukey post test. Antimicrobial activity test was conducted using agar well diffusion assay. Clinical isolates tested were Salmonella typhi, Salmonella paratyphi, Salmonella typhimurium, Shigella species, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. Results In castor oil induced diarrhea model, the 80% methanol leaf extract of C. aurea at 100, 200 and 400 mg/kg and the standard drug loperamide (3 mg/kg) significantly reduced the time of onset of diarrhea, the frequency of defecation (total number of faecal output) and weight of faeces. C. aurea leaf extract

  4. Antimicrobial activities of Saudi honey against Pseudomonas aeruginosa

    PubMed Central

    Al-Nahari, Alaa A.M.; Almasaudi, Saad B.; Abd El-Ghany, El Sayed M.; Barbour, Elie; Al Jaouni, Soad K.; Harakeh, Steve

    2015-01-01

    Five types of imported and local honey were screened for both their bacteriocidal/bacteriostatic activities against both Imipenem resistant and sensitive Pseudomonas aeruginosa in both Brain Heart infusion broth and Mueller–Hinton agar. The results indicated that the effect was concentration and type of honey dependant. All types of honey tested exerted a full inhibition of bacterial growth at the highest concentration tested of 50% at 24 h of contact. The inhibitory effect of honey on bacterial growth was clear with concentrations of 20% and 10% and this effect was most evident in the case of Manuka honey as compared to Nigella sativa honey and Seder honey. Manuka honey UMF +20 showed a bacteriocidal activity on both Imipenem resistant and sensitive P. aeruginosa, while Seder honey and N. sativa honey exerted only a bacteriostatic effect. Manuka honey UMF +10 showed most effect on antimicrobial resistance. Manuka honey UMF +10 had an effect on modulation of Imipenem resistant P. aeruginosa. Conclusion: The results indicated that various types of honey affected the test organisms differently. Modulation of antimicrobial resistance was seen in the case Manuka honey UMF +10. PMID:26288553

  5. Antimicrobial and cytotoxic effects of Mexican medicinal plants.

    PubMed

    Jacobo-Salcedo, Maria del Rosario; Alonso-Castro, Angel Josabad; Salazar-Olivo, Luis A; Carranza-Alvarez, Candy; González-Espíndola, Luis Angel; Domínguez, Fabiola; Maciel-Torres, Sandra Patricia; García-Lujan, Concepción; González-Martínez, Marisela del Rocio; Gómez-Sánchez, Maricela; Estrada-Castillón, Eduardo; Zapata-Bustos, Rocio; Medellin-Milán, Pedro; García-Carrancá, Alejandro

    2011-12-01

    The antimicrobial effects of the Mexican medicinal plants Guazuma ulmifolia, Justicia spicigera, Opuntia joconostle, O. leucotricha, Parkinsonia aculeata, Phoradendron longifolium, P. serotinum, Psittacanthus calyculatus, Tecoma stans and Teucrium cubense were tested against several human multi-drug resistant pathogens, including three Gram (+) and five Gram (-) bacterial species and three fungal species using the disk-diffusion assay. The cytotoxicity of plant extracts on human cancer cell lines and human normal non-cancerous cells was also evaluated using the MTT assay. Phoradendron longifolium, Teucrium cubense, Opuntia joconostle, Tecoma stans and Guazuma ulmifolia showed potent antimicrobial effects against at least one multidrug-resistant microorganism (inhibition zone > 15 mm). Only Justicia spicigera and Phoradendron serotinum extracts exerted active cytotoxic effects on human breast cancer cells (IC50 < or = 30 microg/mL). The results showed that Guazuma ulmifolia produced potent antimicrobial effects against Candida albicans and Acinetobacter lwoffii, whereas Justicia spicigera and Phoradendron serotinum exerted the highest toxic effects on MCF-7 and HeLa, respectively, which are human cancer cell lines. These three plant species may be important sources of antimicrobial and cytotoxic agents. PMID:22312741

  6. Synergistic Antimicrobial Activity of Camellia sinensis and Juglans regia against Multidrug-Resistant Bacteria

    PubMed Central

    Farooqui, Amber; Khan, Adnan; Borghetto, Ilaria; Kazmi, Shahana U.; Rubino, Salvatore; Paglietti, Bianca

    2015-01-01

    Synergistic combinations of antimicrobial agents with different mechanisms of action have been introduced as more successful strategies to combat infections involving multidrug resistant (MDR) bacteria. In this study, we investigated synergistic antimicrobial activity of Camellia sinensis and Juglans regia which are commonly used plants with different antimicrobial agents. Antimicrobial susceptibility of 350 Gram-positive and Gram-negative strains belonging to 10 different bacterial species, was tested against Camellia sinensis and Juglans regia extracts. Minimum inhibitory concentrations (MICs) were determined by agar dilution and microbroth dilution assays. Plant extracts were tested for synergistic antimicrobial activity with different antimicrobial agents by checkerboard titration, Etest/agar incorporation assays, and time kill kinetics. Extract treated and untreated bacteria were subjected to transmission electron microscopy to see the effect on bacterial cell morphology. Camellia sinensis extract showed higher antibacterial activity against MDR S. Typhi, alone and in combination with nalidixic acid, than to susceptible isolates.” We further explore anti-staphylococcal activity of Juglans regia that lead to the changes in bacterial cell morphology indicating the cell wall of Gram-positive bacteria as possible target of action. The synergistic combination of Juglans regia and oxacillin reverted oxacillin resistance of methicillin resistant Staphylococcus aureus (MRSA) strains in vitro. This study provides novel information about antimicrobial and synergistic activity of Camellia sinensis and Juglans regia against MDR pathogens PMID:25719410

  7. Synthesis and Antimicrobial Activity of the Hybrid Molecules between Sulfonamides and Active Antimicrobial Pleuromutilin Derivative.

    PubMed

    Chen, Liangzhu; Yang, Dexue; Pan, Zhikun; Lai, Lihong; Liu, Jianhua; Fang, Binghu; Shi, Shuning

    2015-08-01

    A series of novel hybrid molecules between sulfonamides and active antimicrobial 14-o-(3-carboxy-phenylsulfide)-mutilin were synthesized, and their in vitro antibacterial activities were evaluated by the broth microdilution. Results indicated that these compounds displayed potent antimicrobial activities in vitro against various drug-susceptible and drug-resistant Gram-positive bacteria such as Staphylococci and streptococci, including methicillin-resistant Staphylococcus aureus, and mycoplasma. In particular, sulfapyridine analog (6c) exhibited more potent inhibitory activity against Gram-positive bacteria and mycoplasma, including Staphylococcus aureus (MIC = 0.016-0.063 μg/mL), methicillin-resistant Staphylococcus aureus (MIC = 0.016 μg/mL), Streptococcus pneumoniae (MIC = 0.032-0.063 μg/mL), Mycoplasma gallisepticum (MIC = 0.004 μg/mL), with respect to other synthesized compounds and reference drugs sulfonamide (MIC = 8-128 μg/mL) and valnemulin (MIC = 0.004-0.5 μg/mL). Furthermore, comparison between MIC values of pleuromutilin-sulfonamide hybrids 6a-f with pleuromutilin parent compound 3 revealed that these modifications at 14 position side chain of the pleuromutilin with benzene sulfonamide could greatly improve the antibacterial activity especially against Gram-positives. PMID:25431015

  8. Antimicrobial activities of three species of family mimosaceae.

    PubMed

    Mahmood, Adeel; Mahmood, Aqeel; Qureshi, Rizwana Aleem

    2012-01-01

    The antimicrobial activities of crude methanolic extract of leaves of Acacia nilotica L., Albizia lebbeck L. and Mimosa himalayana Gamble belonging to family mimosaceae were investigated in this research work. Antibacterial activity was studied by agar well diffusion method against one gram-positive Bacillus subtilis and three gram-negative Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumonia. Crude extract of all plants showed best activity against gram-negative bacterial strains while minor inhibition zones were found against gram positive bacterial strains. Antifungal activity of crude plant extract was screened by agar tube dilution method against Aspergillus nigar and Aspergillus flavus. These results showed that these plants extracts have potential against bacterias, while against fungi their activity is not much effective. PMID:22186331

  9. Rational design of tryptophan-rich antimicrobial peptides with enhanced antimicrobial activities and specificities.

    PubMed

    Yu, Hui-Yuan; Huang, Kuo-Chun; Yip, Bak-Sau; Tu, Chih-Hsiang; Chen, Heng-Li; Cheng, Hsi-Tsung; Cheng, Jya-Wei

    2010-11-01

    Trp-rich antimicrobial peptides play important roles in the host innate defense mechanism of many plants and animals. A series of short Trp-rich peptides derived from the C-terminal region of Bothrops asper myothoxin II, a Lys49 phospholipase A(2) (PLA(2)), were found to reproduce the antimicrobial activities of their parent molecule. Of these peptides, KKWRWWLKALAKK-designated PEM-2-was found to display improved activity against both Gram-positive and Gram-negative bacteria. To improve the antimicrobial activity of PEM-2 for potential clinical applications further, we determined the solution structure of PEM-2 bound to membrane-mimetic dodecylphosphocholine (DPC) micelles by two-dimensional NMR methods. The DPC micelle-bound structure of PEM-2 adopts an α-helical conformation and the positively charged residues are clustered together to form a hydrophilic patch. The surface electrostatic potential map indicates that two of the three tryptophan residues are packed against the peptide backbone and form a hydrophobic face with Leu7, Ala9, and Leu10. A variety of biophysical and biochemical experiments, including circular dichroism, fluorescence spectroscopy, and microcalorimetry, were used to show that PEM-2 interacted with negatively charged phospholipid vesicles and efficiently induced dye release from these vesicles, suggesting that the antimicrobial activity of PEM-2 could be due to interactions with bacterial membranes. Potent analogues of PEM-2 with enhanced antimicrobial and less pronounced hemolytic activities were designed with the aid of these structural studies. PMID:20865718

  10. Comparison of the antimicrobial and cytotoxic activities of twenty unsaturated sesquiterpene dialdehydes from plants and mushrooms.

    PubMed

    Anke, H; Sterner, O

    1991-08-01

    Twenty unsaturated sesquiterpene dialdehydes were tested for antimicrobial, algaecidal, cytotoxic, and mutagenic activity. In addition to the known antifungal activity, polygodial (1) also exhibited antibacterial and cytotoxic activity; epipolygodial (2) was slightly less active. The most active compounds were: isovelleral (7), isoisovelleral (8), velleral (20), and methylmarasmate (6). With the exception of velleral (20), they also exhibited mutagenic activity in the Salmonella/microsome assay. Derivatization to less polar compounds usually increased the antimicrobial and cytotoxic effects and reduced mutagenicity, while the introduction of hydroxyl groups had the reverse effect. PMID:1775575

  11. Oxidized amylose with high carboxyl content: A promising solubilizer and carrier of linalool for antimicrobial activity.

    PubMed

    Zhou, Ying; Ye, Youxin; Zhang, Wenwen; Li, Songling; Chen, Jing; Wang, Shiting; Li, Defu; Mu, Changdao

    2016-12-10

    The oxidized amyloses with different carboxyl content were prepared to include linalool for antimicrobial activity in aqueous environment. The results show that linalool can be effectively reserved from volatilization through encapsulation into amylose and oxidized amyloses. The inclusion ability of oxidized amyloses towards linalool is decreasing with the increase of oxidation level due to the depolymerization of amylose. However, the solubilization effect of oxidized amyloses to linalool is enhanced efficiently owning to the high water solubility of oxidized amyloses. It is interesting that the inclusion complexes have good antimicrobial activity in aqueous environment. Linalool solubilized by oxidized amyloses presents better antimicrobial performance than that solubilized by amylose, mainly resulting from that amylose-linalool inclusion complex would aggregate and retrograde fast in aqueous solution, which is disadvantageous for the release of linalool. The study suggests that oxidized amylose is a promising solubilizer and carrier of linalool for antimicrobial activity in aqueous environment. PMID:27577891

  12. Silver activation on thin films of Ag-ZrCN coatings for antimicrobial activity.

    PubMed

    Ferreri, I; Calderon V, S; Escobar Galindo, R; Palacio, C; Henriques, M; Piedade, A P; Carvalho, S

    2015-10-01

    Nowadays, with the increase of elderly population and related health problems, knee and hip joint prosthesis are being widely used worldwide. However, failure of these invasive devices occurs in a high percentage thus demanding the revision of the chirurgical procedure. Within the reasons of failure, microbial infections, either hospital or subsequently-acquired, contribute in high number to the statistics. Staphylococcus epidermidis (S. epidermidis) has emerged as one of the major nosocomial pathogens associated with these infections. Silver has a historic performance in medicine due to its potent antimicrobial activity, with a broad-spectrum on the activity of different types of microorganisms. Consequently, the main goal of this work was to produce Ag-ZrCN coatings with antimicrobial activity, for the surface modification of hip prostheses. Thin films of ZrCN with several silver concentrations were deposited onto stainless steel 316 L, by DC reactive magnetron sputtering, using two targets, Zr and Zr with silver pellets (Zr+Ag target), in an atmosphere containing Ar, C2H2 and N2. The antimicrobial activity of the modified surfaces was tested against S. epidermidis and the influence of an activation step of silver was assessed by testing samples after immersion in a 5% (w/v) NaClO solution for 5 min. The activation procedure revealed to be essential for the antimicrobial activity, as observed by the presence of an inhibition halo on the surface with 11 at.% of Ag. The morphology analysis of the surface before and after the activation procedure revealed differences in silver distribution indicating segregation/diffusion of the metallic element to the film's surface. Thus, the results indicate that the silver activation step is responsible for an antimicrobial effect of the coatings, due to silver oxidation and silver ion release. PMID:26117788

  13. Endophytic Fungi Isolated from Coleus amboinicus Lour Exhibited Antimicrobial Activity

    PubMed Central

    Astuti, Puji; Sudarsono, Sudarsono; Nisak, Khoirun; Nugroho, Giri Wisnu

    2014-01-01

    Purpose: Coleus amboinicus is a medicinal plant traditionally used to treat various diseases such as throat infection, cough and fever, diarrhea, nasal congestion and digestive problems. The plant was explored for endophytic fungi producing antimicrobial agents. Methods: Screening for endophytic fungi producing antimicrobial agents was conducted using agar plug method and antimicrobial activity of promising ethyl acetate extracts was determined by disc diffusion assay. Thin layer chromatography (TLC) - bioautography was performed to localize the bioactive components within the extract. TLC visualization detection reagents were used to preliminary analyze phytochemical groups of the bioactive compounds. Results: Three endophytic fungi were obtained, two of them showed promising potential. Agar diffusion method showed that endophytic fungi CAL-2 exhibited antimicrobial activity against P. aeruginosa, B. subtilis, S. aureus and S. thypi, whilst CAS-1 inhibited the growth of B. subtilis. TLC bioautography of ethyl acetate extract of CAL-2 revealed at least three bands exhibited antimicrobial activity and at least two bands showed inhibition of B. subtilis growth. Preliminary analysis of the crude extracts suggests that bioactive compounds within CAL-2 extract are terpenoids, phenolics and phenyl propanoid compounds whilst the antimicrobial agents within CAS-1 extract are terpenoids, propylpropanoids, alkaloids or heterocyclic nitrogen compounds. Conclusion: These data suggest the potential of endophytic fungi of C. amboinicus as source for antimicrobial agents. PMID:25671195

  14. Antimicrobial activity of flavonoids from leaves of Tagetes minuta.

    PubMed

    Tereschuk, M L; Riera, M V; Castro, G R; Abdala, L R

    1997-05-01

    The total extract and fractions with different solvents, obtained from leaves of Tagetes minuta, showed several degrees of antimicrobial activity against Gram positive and Gram negative microorganisms. The same fractions were inactive against Lactobacillus, Zymomonas and Saccharomices species. The major component of the extract: quercetagetin-7-arabinosyl-galactoside, showed significant antimicrobial activity on pathogen microorganisms tested. Correlation results were carried out using chloramphenicol as standard antibiotic. PMID:9201613

  15. Antimicrobial activity and the mechanism of silver nanoparticle thermosensitive gel

    PubMed Central

    Chen, Meiwan; Yang, Zhiwen; Wu, Hongmei; Pan, Xin; Xie, Xiaobao; Wu, Chuanbin

    2011-01-01

    Purpose The purpose of the present study was to elucidate the antimicrobial activity and mechanism of silver nanoparticles incorporated into thermosensitive gel (S-T-Gel) on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Patients and methods This study investigated the growth, permeability, and morphology of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa cells in order to observe the action of S-T-Gel on the membrane structure of these three bacteria. The cell morphology of normal and treated bacteria cells was assessed by transmission electron microscopy (TEM), and the effects of S-T-Gel on genome DNA of bacterial cells were evaluated by agarose gel electrophoresis. Results S-T-Gel showed promising activity against Staphylococcus aureus and moderate activity against Escherichia coli and Pseudomonas aeruginosa. The observation with TEM suggested that S-T-Gel may destroy the structure of bacterial cell membranes in order to enter the bacterial cell. S-T-Gel then condensed DNA and combined and coagulated with the cytoplasm of the damaged bacteria, resulting in the leakage of the cytoplasmic component and the eventual death of these three bacteria. In addition, the analysis of agarose gel electrophoresis demonstrated that S-T-Gel could increase the decomposability of genome DNA. Conclusion These results about promising antimicrobial activity and mechanism of S-T-Gel may be useful for further research and development in in-vivo studies. PMID:22131833

  16. Comparative Study of Surface-Active Properties and Antimicrobial Activities of Disaccharide Monoesters

    PubMed Central

    Zhang, Xi; Song, Fei; Taxipalati, Maierhaba; Wei, Wei; Feng, Fengqin

    2014-01-01

    The objective of this research was to determine the effect of sugar or fatty acid in sugar ester compounds on the surface-active properties and antimicrobial activities of these compounds. Disaccharides of medium-chain fatty acid monoesters were synthesized through transesterifications by immobilized lipase (Lipozyme TLIM) to yield nine monoesters for subsequent study. Their antimicrobial activities were investigated using three pathogenic microorganisms: Staphylococcus aureus, Escherichia coli O157:H7 and Candida albicans. Their surface-active properties including air–water surface tension, critical micelle concentration, and foaming and emulsion power and stability were also studied. The results showed that all of the tested monoesters were more effective against Staphylococcus aureus (Gram-positive bacterium) than against Escherichia coli O157:H7 (Gram-negative bacterium). The results demonstrated that the carbon chain length was the most important factor influencing the surface properties, whereas degree of esterification and hydrophilic groups showed little effect. PMID:25531369

  17. Comparative study of surface-active properties and antimicrobial activities of disaccharide monoesters.

    PubMed

    Zhang, Xi; Song, Fei; Taxipalati, Maierhaba; Wei, Wei; Feng, Fengqin

    2014-01-01

    The objective of this research was to determine the effect of sugar or fatty acid in sugar ester compounds on the surface-active properties and antimicrobial activities of these compounds. Disaccharides of medium-chain fatty acid monoesters were synthesized through transesterifications by immobilized lipase (Lipozyme TLIM) to yield nine monoesters for subsequent study. Their antimicrobial activities were investigated using three pathogenic microorganisms: Staphylococcus aureus, Escherichia coli O157:H7 and Candida albicans. Their surface-active properties including air-water surface tension, critical micelle concentration, and foaming and emulsion power and stability were also studied. The results showed that all of the tested monoesters were more effective against Staphylococcus aureus (Gram-positive bacterium) than against Escherichia coli O157:H7 (Gram-negative bacterium). The results demonstrated that the carbon chain length was the most important factor influencing the surface properties, whereas degree of esterification and hydrophilic groups showed little effect. PMID:25531369

  18. Antimicrobial activity of mosquito cecropin peptides against Francisella.

    PubMed

    Kaushal, Akanksha; Gupta, Kajal; Shah, Ruhee; van Hoek, Monique L

    2016-10-01

    Francisella tularensis is the cause of the zoonotic disease tularemia. In Sweden and Scandinavia, epidemiological studies have implicated mosquitoes as a vector. Prior research has demonstrated the presence of Francisella DNA in infected mosquitoes but has not shown definitive transmission of tularemia from a mosquito to a mammalian host. We hypothesized that antimicrobial peptides, an important component of the innate immune system of higher organisms, may play a role in mosquito host-defense to Francisella. We established that Francisella sp. are susceptible to two cecropin antimicrobial peptides derived from the mosquito Aedes albopictus as well as Culex pipiens. We also demonstrated induced expression of Aedes albopictus antimicrobial peptide genes by Francisella infection C6/36 mosquito cell line. We demonstrate that mosquito antimicrobial peptides act against Francisella by disrupting the cellular membrane of the bacteria. Thus, it is possible that antimicrobial peptides may play a role in the inability of mosquitoes to establish an effective natural transmission of tularemia. PMID:27235883

  19. Size-dependent antimicrobial effects of novel palladium nanoparticles.

    PubMed

    Adams, Clara P; Walker, Katherine A; Obare, Sherine O; Docherty, Kathryn M

    2014-01-01

    Investigating the interactions between nanoscale materials and microorganisms is crucial to provide a comprehensive, proactive understanding of nanomaterial toxicity and explore the potential for novel applications. It is well known that nanomaterial behavior is governed by the size and composition of the particles, though the effects of small differences in size toward biological cells have not been well investigated. Palladium nanoparticles (Pd NPs) have gained significant interest as catalysts for important carbon-carbon and carbon-heteroatom reactions and are increasingly used in the chemical industry, however, few other applications of Pd NPs have been investigated. In the present study, we examined the antimicrobial capacity of Pd NPs, which provides both an indication of their usefulness as target antimicrobial compounds, as well as their potency as potential environmental pollutants. We synthesized Pd NPs of three different well-constrained sizes, 2.0 ± 0.1 nm, 2.5 ± 0.2 nm and 3.1 ± 0.2 nm. We examined the inhibitory effects of the Pd NPs and Pd(2+) ions toward gram negative Escherichia coli (E. coli) and gram positive Staphylococcus aureus (S. aureus) bacterial cultures throughout a 24 hour period. Inhibitory growth effects of six concentrations of Pd NPs and Pd(2+) ions (2.5 × 10(-4), 10(-5), 10(-6), 10(-7), 10(-8), and 10(-9) M) were examined. Our results indicate that Pd NPs are generally much more inhibitory toward S. aureus than toward E. coli, though all sizes are toxic at ≥ 10(-5) M to both organisms. We observed a significant difference in size-dependence of antimicrobial activity, which differed based on the microorganism tested. Our work shows that Pd NPs are highly antimicrobial, and that fine-scale (<1 nm) differences in size can alter antimicrobial activity. PMID:24465824

  20. Size-Dependent Antimicrobial Effects of Novel Palladium Nanoparticles

    PubMed Central

    Adams, Clara P.; Walker, Katherine A.; Obare, Sherine O.; Docherty, Kathryn M.

    2014-01-01

    Investigating the interactions between nanoscale materials and microorganisms is crucial to provide a comprehensive, proactive understanding of nanomaterial toxicity and explore the potential for novel applications. It is well known that nanomaterial behavior is governed by the size and composition of the particles, though the effects of small differences in size toward biological cells have not been well investigated. Palladium nanoparticles (Pd NPs) have gained significant interest as catalysts for important carbon-carbon and carbon-heteroatom reactions and are increasingly used in the chemical industry, however, few other applications of Pd NPs have been investigated. In the present study, we examined the antimicrobial capacity of Pd NPs, which provides both an indication of their usefulness as target antimicrobial compounds, as well as their potency as potential environmental pollutants. We synthesized Pd NPs of three different well-constrained sizes, 2.0±0.1 nm, 2.5±0.2 nm and 3.1±0.2 nm. We examined the inhibitory effects of the Pd NPs and Pd2+ ions toward gram negative Escherichia coli (E. coli) and gram positive Staphylococcus aureus (S. aureus) bacterial cultures throughout a 24 hour period. Inhibitory growth effects of six concentrations of Pd NPs and Pd2+ ions (2.5×10−4, 10−5, 10−6, 10−7, 10−8, and 10−9 M) were examined. Our results indicate that Pd NPs are generally much more inhibitory toward S. aureus than toward E. coli, though all sizes are toxic at ≥10−5 M to both organisms. We observed a significant difference in size-dependence of antimicrobial activity, which differed based on the microorganism tested. Our work shows that Pd NPs are highly antimicrobial, and that fine-scale (<1 nm) differences in size can alter antimicrobial activity. PMID:24465824

  1. Poly(anhydride-esters) comprised exclusively of naturally occurring antimicrobials and EDTA: antioxidant and antibacterial activities.

    PubMed

    Carbone-Howell, Ashley L; Stebbins, Nicholas D; Uhrich, Kathryn E

    2014-05-12

    Carvacrol, thymol, and eugenol are naturally occurring phenolic compounds known to possess antimicrobial activity against a range of bacteria, as well as antioxidant activity. Biodegradable poly(anhydride-esters) composed of an ethylenediaminetetraacetic acid (EDTA) backbone and antimicrobial pendant groups (i.e., carvacrol, thymol, or eugenol) were synthesized via solution polymerization. The resulting polymers were characterized to confirm their chemical composition and understand their thermal properties and molecular weight. In vitro release studies demonstrated that polymer hydrolytic degradation was complete after 16 days, resulting in the release of free antimicrobials and EDTA. Antioxidant and antibacterial assays determined that polymer release media exhibited bioactivity similar to that of free compound, demonstrating that polymer incorporation and subsequent release had no effect on activity. These polymers completely degrade into components that are biologically relevant and have the capability to promote preservation of consumer products in the food and personal care industries via antimicrobial and antioxidant pathways. PMID:24702678

  2. Effectiveness of antimicrobial food packaging materials.

    PubMed

    Cooksey, K

    2005-10-01

    Antimicrobial additives have been used successfully for many years as direct food additives. The literature provides evidence that some of these additives may be effective as indirect food additives incorporated into food packaging materials. Antimicrobial food packaging is directed toward the reduction of surface contamination of processed, prepared foods such as sliced meats and Frankfurter sausages (hot dogs). The use of such packaging materials is not meant to be a substitute for good sanitation practices, but it should enhance the safety of food as an additional hurdle for the growth of pathogenic and/or spoilage microorganisms. Studies have focused on establishing methods for coating low-density polyethylene film or barrier films with methyl cellulose as a carrier for nisin. These films have significantly reduced the presence of Listeria monocytogenes in solutions and in vacuum packaged hot dogs. Other research has focused on the use of chitosan to inhibit L. monocytogenes and chlorine dioxide sachets for the reduction of Salmonella on modified atmosphere-packaged fresh chicken breasts. Overall, antimicrobial packaging shows promise as an effective method for the inhibition of certain bacteria in foods, but barriers to their commercial implementation continue to exist. PMID:16227182

  3. Peptidotriazoles with antimicrobial activity against bacterial and fungal plant pathogens.

    PubMed

    Güell, Imma; Micaló, Lluís; Cano, Laura; Badosa, Esther; Ferre, Rafael; Montesinos, Emilio; Bardají, Eduard; Feliu, Lidia; Planas, Marta

    2012-01-01

    We designed and prepared peptidotriazoles based on the antimicrobial peptide BP100 (LysLysLeuPheLysLysIleLeuLysTyrLeu-NH(2)) by introducing a triazole ring in the peptide backbone or onto the side chain of a selected residue. These compounds were screened for their in vitro growth inhibition of bacterial and fungal phytopathogens, and for their cytotoxic effects on eukaryotic cells and tobacco leaves. Their proteolytic susceptibility was also analyzed. The antibacterial activity and the hemolysis were influenced by the amino acid that was modified with the triazole as well as by the absence of presence of a substituent in this heterocyclic ring. We identified sequences active against the bacteria Xanthomonas axonopodis pv. vesicatoria, Erwinia amylovora, Pseudomonas syringae pv. syringae (MIC of 1.6-12.5 μM), and against the fungi Fusarium oxysporum (MIC<6.2-12.5 μM) with low hemolytic activity (0-23% at 50 μM), high stability to protease digestion and no phytotoxicity. These peptidotriazoles constitute good candidates to design new antimicrobial agents. PMID:22198367

  4. Polymer-Ag nanocomposites with enhanced antimicrobial activity against bacterial infection.

    PubMed

    Mei, Lin; Lu, Zhentan; Zhang, Xinge; Li, Chaoxing; Jia, Yanxia

    2014-09-24

    Herein, a nontoxic nanocomposite is synthesized by reduction of silver nitrate in the presence of a cationic polymer displaying strong antimicrobial activity against bacterial infection. These nanocomposites with a large concentration of positive charge promote their adsorption to bacterial membranes through electrostatic interaction. Moreover, the synthesized nanocomposites with polyvalent and synergistic antimicrobial effects can effectively kill both Gram-positive and Gram-negative bacteria without the emergence of bacterial resistance. Morphological changes obtained by transmission electron microscope observation show that these nanocomposites can cause leakage and chaos of intracellular contents. Analysis of the antimicrobial mechanism confirms that the lethal action of nanocomposites against the bacteria started with disruption of the bacterial membrane, subsequent cellular internalization of the nanoparticles, and inhibition of intracellular enzymatic activity. This novel antimicrobial material with good cytocompatibility promotes healing of infected wounds in diabetic rats, and has a promising future in the treatment of other infectious diseases. PMID:25170799

  5. Phytochemical profiles, antioxidant and antimicrobial activities of three Potentilla species

    PubMed Central

    2013-01-01

    Background Extracts from Potentilla species have been applied in traditional medicine and exhibit antioxidant, hypoglycemic, anti-inflammatory, antitumor and anti-ulcerogenic properties, but little has been known about the diversity of phytochemistry and pharmacology on this genus. This study investigated and compared the phytochemical profiles, antioxidant and antimicrobial activities of leaf extracts from three Potentilla species (Potentilla fruticosa, Potentilla glabra and Potentilla parvifolia) in order to discover new resources for lead structures and pharmaceutical products. Methods Chemical composition and content of six phenolic compounds were evaluated and determined by RP-HPLC; Total phenolic and total flavonoid content were determined using Folin-Ciocalteau colourimetric method and sodium borohydride/chloranil-based method (SBC); Antioxidant activities were determined using DPPH, ABTS and FRAP assays; Antimicrobial properties were investigated by agar dilution and mycelial growth rate method. Results The results showed hyperoside was the predominant phenolic compound in three Potentilla species by RP-HPLC assay, with the content of 8.86 (P. fruticosa), 2.56 (P. glabra) and 2.68 mg/g (P. parvifolia), respectively. The highest content of total identified phenolic compounds (hyperoside, (+)-catechin, caffeic acid, ferulic acid, rutin and ellagic acid) was observed in P. parvifolia (14.17 mg/g), follow by P. fruticosa (10.01 mg/g) and P. glabra (7.01 mg/g). P. fruticosa possessed the highest content of total phenolic (84.93 ± 0.50 mmol gallic acid equivalent/100 g) and total flavonoid (84.14 ± 0.03 mmol quercetin equivalent/100 g), which were in good correlation with its significant DPPHIC50 (16.87 μg/mL), ABTS (2763.48 μmol Trolox equivalent/g) and FRAP (1398.70 μmol Trolox equivalent/g) capacities. Furthermore, the effective methodology to distinguish the different species of Potentilla was also established by chromatographic fingerprint analysis for

  6. Synergistic Effects of Antimicrobial Peptides and Antibiotics against Clostridium difficile

    PubMed Central

    Nuding, Sabine; Frasch, Tina; Schaller, Martin; Stange, Eduard F.

    2014-01-01

    Accelerating rates of health care-associated infections caused by Clostridium difficile, with increasing recurrence and rising antibiotic resistance rates, have become a serious problem in recent years. This study was conducted to explore whether a combination of antibiotics with human antimicrobial peptides may lead to an increase in antibacterial activity. The in vitro activities of the antimicrobial peptides HBD1 to HBD3, HNP1, HD5, and LL-37 and the antibiotics tigecycline, moxifloxacin, piperacillin-tazobactam, and meropenem alone or in combination against 10 toxinogenic and 10 nontoxinogenic C. difficile strains were investigated. Bacterial viability was determined by flow cytometry and toxin production by enzyme-linked immunosorbent assay (ELISA). When combined at subinhibitory concentrations, antimicrobial peptides and antibiotics generally led to an additive killing effect against toxinogenic and nontoxinogenic C. difficile strains. However, LL-37 and HBD3 acted in synergism with all the antibiotics that were tested. Electron microscopy revealed membrane perturbation in bacterial cell walls by HBD3. In 3 out of 10 toxinogenic strains, HBD3, LL-37, piperacillin-tazobactam, and meropenem administration led to an increased toxin release which was not neutralized by the addition of HNP1. Antimicrobial peptides increase the bacterial killing of antibiotics against C. difficile regardless of the antibiotics' mode of action. Membrane perturbation in or pore formation on the bacterial cell wall may enhance the uptake of antibiotics and increase their antibacterial effect. Therefore, a combination of antibiotics with antimicrobial peptides may represent a promising novel approach to the treatment of C. difficile infections. PMID:25022581

  7. Immunomodulatory and Antimicrobial Activity of Babassu Mesocarp Improves the Survival in Lethal Sepsis

    PubMed Central

    Prado, Dayanna S.; Barcellos, Priscila S.; Gonçalves, Azizedite G.

    2016-01-01

    Attalea speciosa syn Orbignya phalerata Mart. (babassu) has been used in the treatment of inflammatory and infectious diseases. Aim of the study. To investigate the antimicrobial and immunological activity of babassu mesocarp extract (EE). Material and Methods. The in vitro antimicrobial activity was evaluated by disk diffusion assay and by determination of the minimum inhibitory concentration (MIC) to Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA). The flavonoids and phenolic acids content were determined by chromatography. The in vivo assays were performed in Swiss mice submitted to sepsis by cecal ligation and puncture (CLP). The mice received EE subcutaneously (125 or 250 mg/Kg), 6 hours after the CLP. The number of lymphoid cells was quantified and the cytokines production was determined by ELISA after 12 h. Results. EE was effective as antimicrobial to E. faecalis, S. aureus, and MRSA. EE is rich in phenolic acids, a class of compounds with antimicrobial and immunological activity. An increased survival can be observed in those groups, possibly due to a significant inhibition of TNF-α and IL-6. Conclusions. The EE showed specific antimicrobial activity in vitro and an important antiseptic effect in vivo possibly due to the antimicrobial and immunomodulatory activity.

  8. In vitro antimicrobial activity of four Ficus carica latex fractions against resistant human pathogens (antimicrobial activity of Ficus carica latex).

    PubMed

    Aref, Houda Lazreg; Salah, Karima Bel Hadj; Chaumont, Jean Pierre; Fekih, Abdelwaheb; Aouni, Mahjoub; Said, Khaled

    2010-01-01

    Methanolic, hexanoïc, chloroformic and ethyl acetate extracts of Ficus carica latex were investigated for their in vitro antimicrobial proprieties against five bacteria species and seven strains of fungi. The green fruit latex was collected from Chott Mariam Souse, Middle East coast of Tunisia. The antimicrobial activity of the extracts was evaluated and based respectively on the inhibition zone using the disc-diffusion assay, minimal inhibition concentration (MIC) for bacterial testing and the method by calculating inhibition percentage (I%) for fungi-inhibiting activities. The methanolic extract had no effect against bacteria except for Proteus mirabilis while the ethyl acetate extract had inhibition effect on the multiplication of five bacteria species (Enterococcus fecalis, Citobacter freundei, Pseudomonas aeruginosa, Echerchia coli and Proteus mirabilis). For the opportunist pathogenic yeasts, ethyl acetate and chlorophormic fractions showed a very strong inhibition (100%); methanolic fraction had a total inhibition against Candida albicans (100%) at a concentration of 500 microg/ml and a negative effect against Cryptococcus neoformans. Microsporum canis was strongly inhibited with methanolic extract (75%) and totally with ethyl acetate extract at a concentration of 750 microg/ml. Hexanoïc extract showed medium results. PMID:20067867

  9. Diverse antimicrobial activity from Enterococcus faecium NRRL B-30746 bacteriocin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antibiotic therapy to resolve bacterial disease has been compromised by the increased prevalence and magnitude of bacterial antibiotic resistance. In our efforts to identify new effective antimicrobials, bacteria isolated from poultry intestinal contents were screened for bacteriocin synthesis again...

  10. QSAR study of antimicrobial activity of some 3-nitrocoumarins and related compounds.

    PubMed

    Debeljak, Zeljko; Skrbo, Armin; Jasprica, Ivona; Mornar, Ana; Plecko, Vanda; Banjanac, Mihajlo; Medić-Sarić, Marica

    2007-01-01

    A new class of antimicrobial agents, 3-nitrocoumarins and related compounds, has been chosen as a subject of the present study. In order to explore their activity and molecular properties that determine their antimicrobial effects, QSAR models have been proposed. Most of the 64 descriptors used for the development were extracted from semiempirical and density functional theory (DFT) founded calculations. For this study literature data containing results of microbiological activity screening of 33 coumarin derivatives against selected clinical isolates of C. albicans (CA) and S. aureus (SA) have been selected. Multivariate predictive models based on random forests (RF) and two hybrid classification approaches, genetic algorithms (GA) associated with either support vector machines (SVM) or k nearest neighbor (kNN), have been used for establishment of QSARs. An applied feature selection approach enabled two-dimensional linear separation of active and inactive compounds, which was a necessary tool for rational candidate design and descriptor relevance interpretation. Candidate molecules were checked by cross-validated models, and selected derivatives have been synthesized. Their antimicrobial activities were compared to antimicrobial activities of the representative derivatives from the original set in terms of minimal inhibitory concentration (MIC) against chosen SA and CA ATCC strains. High ranking of descriptors consistent with the degree of hydrolytic instability of selected compounds is common to models of antimicrobial activity against both microorganisms. However, descriptor ranking indicates different antimicrobial mechanisms of action of chosen coumarin derivatives against selected microbial species. PMID:17489552

  11. Antioedematogenic activity, acetylcholinesterase inhibition and antimicrobial properties of Jacaranda oxyphylla.

    PubMed

    Pereira, V V; Silva, R R; Dos Santos, M H; Dias, D F; Moreira, M E C; Takahashi, J A

    2016-09-01

    Jacaranda oxyphylla Cham. (Bignoniaceae) is a shrub found in the Brazilian cerrado and used in folk medicine to treat microbial infections. The aim of this study was to carry out a phytochemical screening and evaluate antioedematogenic, antimicrobial and antiacetylcholinesterase properties of J. oxyphylla crude extracts. All extracts analysed showed presence of terpenoids, which are potentially active chemical substances. A high AChE inhibitory activity for hexane extract from leaves and for the extracts from twigs was found. Ethanol extract from leaves of J. oxyphylla showed activity against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli) bacteria. This extract was also effective in inhibiting the stages of inflammation evaluated. Biological investigation and phytochemical screening of J. oxyphylla extracts provided additional evidence of its traditional medicinal value. PMID:26469996

  12. In vitro antimicrobial activity of pistachio (Pistacia vera L.) polyphenols.

    PubMed

    Bisignano, Carlo; Filocamo, Angela; Faulks, Richard M; Mandalari, Giuseppina

    2013-04-01

    We investigated the antimicrobial properties of polyphenol-rich fractions derived from raw shelled and roasted salted pistachios. American Type Culture Collection (ATCC), food and clinical isolates, of Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Pseudomonas mirabilis), Gram-positive bacteria (Listeria monocytogenes, Enterococcus hirae, Enterococcus faecium, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus), the yeasts Candida albicans and Candida parapsilosis and the fungus Aspergillus niger were used. Pistachio extracts were active against Gram-positive bacteria with a bactericidal effect observed against L. monocytogenes (ATCC strains and food isolates), S. aureus and MRSA clinical isolates. Extracts from raw shelled pistachios were more active than those from roasted salted pistachios. The bactericidal activity of pistachio extracts could be used to help control the growth of some microorganisms in foods to improve safety and may find application as a topical treatment for S. aureus. PMID:23350629

  13. Nanoliposomes containing Eucalyptus citriodora as antibiotic with specific antimicrobial activity.

    PubMed

    Lin, Lin; Cui, Haiying; Zhou, Hui; Zhang, Xuejing; Bortolini, Christian; Chen, Menglin; Liu, Lei; Dong, Mingdong

    2015-02-14

    Bacterial infections are a serious issue for public health and represent one of the major challenges of modern medicine. In this work, a selective antimicrobial strategy based on triggering of pore-forming toxin, which is secreted by infective bacteria, was designed to fight Staphylococcus aureus. The antimicrobial activity is realized by employing Eucalyptus citriodora oil as antibiotic which in this study is encapsulated in nanoliposomes. PMID:25573466

  14. Activity of 10 antimicrobial agents against intracellular Rhodococcus equi.

    PubMed

    Giguère, Steeve; Berghaus, Londa J; Lee, Elise A

    2015-08-01

    Studies with facultative intracellular bacterial pathogens have shown that evaluation of the bactericidal activity of antimicrobial agents against intracellular bacteria is more closely associated with in vivo efficacy than traditional in vitro susceptibility testing. The objective of this study was to determine the relative activity of 10 antimicrobial agents against intracellular Rhodococcus equi. Equine monocyte-derived macrophages were infected with virulent R. equi and exposed to erythromycin, clarithromycin, azithromycin, rifampin, ceftiofur, gentamicin, enrofloxacin, vancomycin, imipenem, or doxycycline at concentrations achievable in plasma at clinically recommended dosages in foals. The number of intracellular R. equi was determined 48h after infection by counting colony forming units (CFUs). The number of R. equi CFUs in untreated control wells were significantly higher than those of monolayers treated with antimicrobial agents. Numbers of R. equi were significantly lower in monolayers treated with enrofloxacin followed by those treated with gentamicin, and vancomycin, when compared to monolayers treated with other antimicrobial agents. Numbers of R. equi in monolayers treated with doxycycline were significantly higher than those of monolayers treated with other antimicrobial agents. Differences in R. equi CFUs between monolayers treated with other antimicrobial agents were not statistically significant. Enrofloxacin, gentamicin, and vancomycin are the most active drugs in equine monocyte-derived macrophages infected with R. equi. Additional studies will be needed to determine if these findings correlate with in vivo efficacy. PMID:26051479

  15. Antimicrobial activity of Uncaria tomentosa against oral human pathogens.

    PubMed

    Ccahuana-Vasquez, Renzo Alberto; Santos, Silvana Soléo Ferreira dos; Koga-Ito, Cristiane Yumi; Jorge, Antonio Olavo Cardoso

    2007-01-01

    Uncaria tomentosa is considered a medicinal plant used over centuries by the peruvian population as an alternative treatment for several diseases. Many microorganisms usually inhabit the human oral cavity and under certain conditions can become etiologic agents of diseases. The aim of the present study was to evaluate the antimicrobial activity of different concentrations of Uncaria tomentosa on different strains of microorganisms isolated from the human oral cavity. Micropulverized Uncaria tomentosa was tested in vitro to determine the minimum inhibitory concentration (MIC) on selected microbial strains. The tested strains were oral clinical isolates of Streptococcus mutans, Staphylococcus spp., Candida albicans, Enterobacteriaceae and Pseudomonas aeruginosa. The tested concentrations of Uncaria tomentosa ranged from 0.25-5% in Müeller-Hinton agar. Three percent Uncaria tomentosa inhibited 8% of Enterobacteriaceae isolates, 52% of S. mutans and 96% of Staphylococcus spp. The tested concentrations did not present inhibitory effect on P. aeruginosa and C. albicans. It could be concluded that micropulverized Uncaria tomentosa presented antimicrobial activity on Enterobacteriaceae, S. mutans and Staphylococcus spp. isolates. PMID:17426895

  16. Application of Artificial Intelligence to the Prediction of the Antimicrobial Activity of Essential Oils

    PubMed Central

    Daynac, Mathieu; Cortes-Cabrera, Alvaro; Prieto, Jose M.

    2015-01-01

    Essential oils (EOs) are vastly used as natural antibiotics in Complementary and Alternative Medicine (CAM). Their intrinsic chemical variability and synergisms/antagonisms between its components make difficult to ensure consistent effects through different batches. Our aim is to evaluate the use of artificial neural networks (ANNs) for the prediction of their antimicrobial activity. Methods. The chemical composition and antimicrobial activity of 49 EOs, extracts, and/or fractions was extracted from NCCLS compliant works. The fast artificial neural networks (FANN) software was used and the output data reflected the antimicrobial activity of these EOs against four common pathogens: Staphylococcus aureus, Escherichia coli, Candida albicans, and Clostridium perfringens as measured by standardised disk diffusion assays. Results. ANNs were able to predict >70% of the antimicrobial activities within a 10 mm maximum error range. Similarly, ANNs were able to predict 2 or 3 different bioactivities at the same time. The accuracy of the prediction was only limited by the inherent errors of the popular antimicrobial disk susceptibility test and the nature of the pathogens. Conclusions. ANNs can be reliable, fast, and cheap tools for the prediction of the antimicrobial activity of EOs thus improving their use in CAM. PMID:26457111

  17. Copper(II) complexes with cyanoguanidine and o-phenanthroline: Theoretical studies, in vitro antimicrobial activity and alkaline phosphatase inhibitory effect

    NASA Astrophysics Data System (ADS)

    Martínez Medina, Juan J.; Islas, María S.; López Tévez, Libertad L.; Ferrer, Evelina G.; Okulik, Nora B.; Williams, Patricia A. M.

    2014-01-01

    Calculations based on density functional methods are carried out for two Cu(II) complexes with cyanoguanidine (cnge) and o-phenanthroline (o-phen): [Cu(o-phen)2(cnge)](NO3)2ṡ2H2O (1) and [Cu(o-phen)(cnge)(H2O)(NO3)2] (2). The calculated geometrical parameters are in agreement with the experimental values. The results of Atoms in Molecules (AIM) topological analysis of the electron density indicate that the Cu-N(phen) bonds in complex (1) have lower electron density, suggesting that those bonds are stronger in complex (2). Moreover, the ionic character of the Cu-N bond in the complex (1) is slightly stronger than that in the complex (2) and this situation would explain the fact that only complex (2) was stable in water solution. For this reason, the antimicrobial and enzymatic assays were performed using complex (2). It is well known that the increased use of antibiotics has resulted in the development of resistant bacterial and fungal strains. In this context, the study of novel antimicrobial agents has an enormous importance and metal complexes represent an interesting alternative for the treatment of infectious diseases. The aim of this work is to prove the modification of some biological properties like antimicrobial activity or alkaline phosphatase inhibitory activity upon copper complexation.

  18. Fungi Treated with Small Chemicals Exhibit Increased Antimicrobial Activity against Facultative Bacterial and Yeast Pathogens

    PubMed Central

    Zutz, Christoph; Bandian, Dragana; Neumayer, Bernhard; Speringer, Franz; Wagner, Martin; Strauss, Joseph

    2014-01-01

    For decades, fungi have been the main source for the discovery of novel antimicrobial drugs. Recent sequencing efforts revealed a still high number of so far unknown “cryptic” secondary metabolites. The production of these metabolites is presumably epigenetically silenced under standard laboratory conditions. In this study, we investigated the effect of six small mass chemicals, of which some are known to act as epigenetic modulators, on the production of antimicrobial compounds in 54 spore forming fungi. The antimicrobial effect of fungal samples was tested against clinically facultative pathogens and multiresistant clinical isolates. In total, 30 samples of treated fungi belonging to six different genera reduced significantly growth of different test organisms compared to the untreated fungal sample (growth log reduction 0.3–4.3). For instance, the pellet of Penicillium restrictum grown in the presence of butyrate revealed significant higher antimicrobial activity against Staphylococcus (S.) aureus and multiresistant S. aureus strains and displayed no cytotoxicity against human cells, thus making it an ideal candidate for antimicrobial compound discovery. Our study shows that every presumable fungus, even well described fungi, has the potential to produce novel antimicrobial compounds and that our approach is capable of rapidly filling the pipeline for yet undiscovered antimicrobial substances. PMID:25121102

  19. Antimicrobial activity of Eucalyptus globulus oil, xylitol and papain: a pilot study.

    PubMed

    Mota, Valéria de Siqueira; Turrini, Ruth Natalia Teresa; Poveda, Vanessa de Brito

    2015-01-01

    OBJECTIVE To evaluate the in vitro antimicrobial activity of the Eucalyptus globulus essential oil, and of the xylitol and papain substances against the following microorganisms: Pseudomonas aeruginosa; Samonella sp.; Staphylococus aureus; Proteus vulgaris; Escherichia coli and Candida albicans. METHOD The in vitro antimicrobial evaluation was used by means of the agar diffusion test and evaluation of the inhibition zone diameter of the tested substances. Chlorhexidine 0.5% was used as control. RESULTS The Eucalyptus globulus oil showed higher inhibition than chlorhexidine when applied to Staphylococcus aureus, and equal inhibition when applied to the following microorganisms: Escherichia coli, Proteus vulgaris and Candida albicans. Papain 10% showed lower antimicrobial effect than chlorhexidine in relation to Candida albicans. Xylitol showed no inhibition of the tested microorganisms. CONCLUSION The Eucalyptus globulus oil has antimicrobial activity against different microorganisms and appears to be a viable alternative as germicidal agent hence, further investigation is recommended. PMID:25992819

  20. Antimicrobial effect of chitosan nanoparticles on streptococcus mutans biofilms.

    PubMed

    Chávez de Paz, Luis E; Resin, Anton; Howard, Kenneth A; Sutherland, Duncan S; Wejse, Peter L

    2011-06-01

    Nanoparticle complexes were prepared from chitosans of various molecular weights (MW) and degrees of deacetylation (DD). The antimicrobial effect was assessed by the Live/Dead BacLight technique in conjunction with confocal scanning laser microscopy (CSLM) and image analysis. Nanocomplexes prepared from chitosans with high MW showed a low antimicrobial effect (20 to 25% of cells damaged), whereas those prepared from low-MW chitosans showed high antimicrobial effect (>95% of cells damaged). PMID:21498764

  1. Antimicrobial Effect of Chitosan Nanoparticles on Streptococcus mutans Biofilms▿

    PubMed Central

    Chávez de Paz, Luis E.; Resin, Anton; Howard, Kenneth A.; Sutherland, Duncan S.; Wejse, Peter L.

    2011-01-01

    Nanoparticle complexes were prepared from chitosans of various molecular weights (MW) and degrees of deacetylation (DD). The antimicrobial effect was assessed by the Live/Dead BacLight technique in conjunction with confocal scanning laser microscopy (CSLM) and image analysis. Nanocomplexes prepared from chitosans with high MW showed a low antimicrobial effect (20 to 25% of cells damaged), whereas those prepared from low-MW chitosans showed high antimicrobial effect (>95% of cells damaged). PMID:21498764

  2. Antimicrobial activity of biogenic silver nanoparticles, and silver chloride nanoparticles: an overview and comments.

    PubMed

    Durán, Nelson; Nakazato, Gerson; Seabra, Amedea B

    2016-08-01

    The antimicrobial impact of biogenic-synthesized silver-based nanoparticles has been the focus of increasing interest. As the antimicrobial activity of nanoparticles is highly dependent on their size and surface, the complete and adequate characterization of the nanoparticle is important. This review discusses the characterization and antimicrobial activity of biogenic synthesized silver nanoparticles and silver chloride nanoparticles. By revising the literature, there is confusion in the characterization of these two silver-based nanoparticles, which consequently affects the conclusion regarding to their antimicrobial activities. This review critically analyzes recent publications on the synthesis of biogenic silver nanoparticles and silver chloride nanoparticles by attempting to correlate the characterization of the nanoparticles with their antimicrobial activity. It was difficult to correlate the size of biogenic nanoparticles with their antimicrobial activity, since different techniques are employed for the characterization. Biogenic synthesized silver-based nanoparticles are not completely characterized, particularly the nature of capped proteins covering the nanomaterials. Moreover, the antimicrobial activity of theses nanoparticles is assayed by using different protocols and strains, which difficult the comparison among the published papers. It is important to select some bacteria as standards, by following international foundations (Pharmaceutical Microbiology Manual) and use the minimal inhibitory concentration by broth microdilution assays from Clinical and Laboratory Standards Institute, which is the most common assay used in antibiotic ones. Therefore, we conclude that to have relevant results on antimicrobial effects of biogenic silver-based nanoparticles, it is necessary to have a complete and adequate characterization of these nanostructures, followed by standard methodology in microbiology protocols. PMID:27289481

  3. Identification and Antimicrobial Activity Detection of Lactic Acid Bacteria Isolated from Corn Stover Silage

    PubMed Central

    Li, Dongxia; Ni, Kuikui; Pang, Huili; Wang, Yanping; Cai, Yimin; Jin, Qingsheng

    2015-01-01

    A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC 43971T, Micrococcus luteus ATCC 4698T and Escherichia coli ATCC 11775T were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at 100°C), but the antimicrobial activity was eliminated after treatment at 121°C for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory. PMID:25924957

  4. Antimicrobial activity of Ulva reticulata and its endophytes

    NASA Astrophysics Data System (ADS)

    Dhanya, K. I.; Swati, V. I.; Vanka, Kanth Swaroop; Osborne, W. J.

    2016-04-01

    Seaweeds are known to exhibit various antimicrobial properties, since it harbours an enormous range of indigenous bioactive compounds. The emergence of drug resistant strains has directed to the identification of prospective metabolites from seaweed and its endophytes, thereby exploiting the properties in resisting bacterial diseases. The current study was aimed to assess the antimicrobial activity of extracts obtained from Ulva reticulate, for which metabolites of Ulva reticulata and its endophytes were extracted and assessed against human pathogens like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Bacillus subtilis. It was observed that the hexane extract of isolate VITDSJ2 was effective against all the tested pathogens but a significant inhibition was observed for Staphylococcus aureus and Escherichia coli. Further, Gas chromatography coupled with Mass spectroscopy (GC-MS) revealed the existence of phenol, 3, 5-bis (1, 1-dimethylethyl) in the crude hexane extract which is well-known to possess antibacterial activity. The effective isolate VITDSJ2 was identified to be the closest neighbour of Pseudomonas stutzeri by phenotypic and genotypic methods. The crude extracts of the seaweed Ulva reticulata was also screened for antibacterial activity and the hexane extract was effective in showing inhibition against all the tested pathogens. The compound in the crude extract of Ulva reticulata was identified as hentriacontane using GC-MS. The extracts obtained from dichloromethane did not show significant activity in comparison with the hexane extracts. Hence the metabolites of Ulva reticulata and the bacterial secondary metabolites of the endophytes could be used in the treatment of bacterial infections.

  5. Investigating the effects of L- to D-amino acid substitution and deamidation on the activity and membrane interactions of antimicrobial peptide anoplin.

    PubMed

    Won, Amy; Khan, Mourin; Gustin, Sorin; Akpawu, Akuvi; Seebun, Deeptee; Avis, Tyler J; Leung, Bonnie O; Hitchcock, Adam P; Ianoul, Anatoli

    2011-06-01

    Isolated from the venom sac of solitary spider wasp, Anoplius samariensis, anoplin is the smallest linear α-helical antimicrobial peptide found naturally with broad spectrum activity against both Gram-positive and Gram-negative bacteria, and little hemolytic activity toward human erythrocytes. Deamidation was found to decrease the peptide's antibacterial properties. In the present work, interactions of amidated (Ano-NH2) and deamidated (Ano-OH) forms of anoplin as well as Ano-NH2 composed of all D-amino acids (D-Ano-NH2) with model cell membranes were investigated by means of Langmuir Blodgett (LB) technique, atomic force microscopy (AFM), X-ray photoemission electron microscopy (X-PEEM) and carboxyfluorescein leakage assay in order to gain a better understanding of the effect of these peptide modifications on membrane binding and lytic properties. According to LB, all three peptides form stable monolayers at the air/water interface with Ano-NH2 occupying a slightly greater area per molecule than Ano-OH. All three forms of the peptide interact preferentially with anionic 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DPPG), rather than zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid monolayer. Peptides form nanoscale clusters in zwitterionic but not in anionic monolayers. Finally, membrane lytic activity of all derivatives was found to depend strongly on membrane composition and lipid/peptide ratio. The results suggest that amidated forms of peptides are likely to possess higher membrane binding affinity due to the increased charge. PMID:21078293

  6. Influence of montmorillonite on antimicrobial activity of tetracycline and ciprofloxacin

    NASA Astrophysics Data System (ADS)

    Lv, Guocheng; Pearce, Cody W.; Gleason, Andrea; Liao, Libing; MacWilliams, Maria P.; Li, Zhaohui

    2013-11-01

    Antibiotics are used not only to fight infections and inhibit bacterial growth, but also as growth promotants in farm livestock. Farm runoff and other farm-linked waste have led to increased antibiotic levels present in the environment, the impact of which is not completely understood. Soil, more specifically clays, that the antibiotic contacts may alter its effectiveness against bacteria. In this study a swelling clay mineral montmorillonite was preloaded with antibiotics tetracycline and ciprofloxacin at varying concentrations and bioassays were conducted to examine whether the antibiotics still inhibited bacterial growth in the presence of montmorillonite. Escherichia coli was incubated with montmorillonite or antibiotic-adsorbed montmorillonite, and then the number of viable bacteria per mL was determined. The antimicrobial activity of tetracycline was affected in the presence of montmorillonite, as the growth of non-resistant bacteria was still found even when extremely high TC doses were used. Conversely, in the presence of montmorillonite, ciprofloxacin did inhibit E. coli bacterial growth at high concentrations. These results suggest that the effectiveness of antimicrobial agents in clayey soils depends on the amount of antibiotic substance present, and on the interactions between the antibiotic and the clays in the soil, as well.

  7. Effects of Annatto (Bixa orellana L.) Seeds Powder on Physicochemical Properties, Antioxidant and Antimicrobial Activities of Pork Patties during Refrigerated Storage

    PubMed Central

    Cuong, Tran Van; Chin, Koo Bok

    2016-01-01

    This study investigated the effect of the powder produced by ball-milling the outer layer of annatto (Bixa orellana L.) seeds on the physicochemical properties as well as the antioxidant and antimicrobial activities of pork patties over 14 d of refrigerated storage (4±1℃). Five pork patty treatments were produced containing three different concentrations of annatto seeds, 0.1, 0.25 and 0.5% (ANT0.1, ANT0.25, ANT0.5), 0.1% ascorbic acid (AA0.1), and a control (CTL). Based on the results, annatto seed powder appeared to show antioxidant activity. The Hunter color values of pork patties were affected by the addition of annatto seed powder, which increased the redness and yellowness values, but decreased the lightness of the patties (p<0.05). To evaluate the antioxidative effects of annatto on pork patties, thiobarbituric acid reactive substances (TBARS) and peroxide values (POV) were analyzed over 14 d of refrigerated storage. Treatments containing annatto seed showed lower TBARS and POV than control (CTL) samples (p<0.05). The volatile basic nitrogen (VBN) of the pork patties containing annatto seeds were lower than that of CTL at the end of storage (p<0.05). Although no differences in total bacterial counts were observed between control and treated patties, those containing annatto seeds had lower microbial counts for Enterobacteriacease than CTL or AA 0.1%. Therefore, annatto seed powder might be a good source of natural antioxidants for the production of meat products. PMID:27621688

  8. Effects of Annatto (Bixa orellana L.) Seeds Powder on Physicochemical Properties, Antioxidant and Antimicrobial Activities of Pork Patties during Refrigerated Storage.

    PubMed

    Cuong, Tran Van; Chin, Koo Bok

    2016-01-01

    This study investigated the effect of the powder produced by ball-milling the outer layer of annatto (Bixa orellana L.) seeds on the physicochemical properties as well as the antioxidant and antimicrobial activities of pork patties over 14 d of refrigerated storage (4±1℃). Five pork patty treatments were produced containing three different concentrations of annatto seeds, 0.1, 0.25 and 0.5% (ANT0.1, ANT0.25, ANT0.5), 0.1% ascorbic acid (AA0.1), and a control (CTL). Based on the results, annatto seed powder appeared to show antioxidant activity. The Hunter color values of pork patties were affected by the addition of annatto seed powder, which increased the redness and yellowness values, but decreased the lightness of the patties (p<0.05). To evaluate the antioxidative effects of annatto on pork patties, thiobarbituric acid reactive substances (TBARS) and peroxide values (POV) were analyzed over 14 d of refrigerated storage. Treatments containing annatto seed showed lower TBARS and POV than control (CTL) samples (p<0.05). The volatile basic nitrogen (VBN) of the pork patties containing annatto seeds were lower than that of CTL at the end of storage (p<0.05). Although no differences in total bacterial counts were observed between control and treated patties, those containing annatto seeds had lower microbial counts for Enterobacteriacease than CTL or AA 0.1%. Therefore, annatto seed powder might be a good source of natural antioxidants for the production of meat products. PMID:27621688

  9. Structure-Activity Relationship of Benzophenanthridine Alkaloids from Zanthoxylum rhoifolium Having Antimicrobial Activity

    PubMed Central

    Tavares, Luciana de C.; Zanon, Graciane; Weber, Andréia D.; Neto, Alexandre T.; Mostardeiro, Clarice P.; Da Cruz, Ivana B. M.; Oliveira, Raul M.; Ilha, Vinicius; Dalcol, Ionara I.; Morel, Ademir F.

    2014-01-01

    Zanthoxylum rhoifolium (Rutaceae) is a plant alkaloid that grows in South America and has been used in Brazilian traditional medicine for the treatment of different health problems. The present study was designed to evaluate the antimicrobial activity of the steam bark crude methanol extract, fractions, and pure alkaloids of Z. rhoifolium. Its stem bark extracts exhibited a broad spectrum of antimicrobial activity, ranging from 12.5 to 100 µg/mL using bioautography method, and from 125 to 500 µg/mL in the microdilution bioassay. From the dichloromethane basic fraction, three furoquinoline alkaloids (1–3), and nine benzophenanthridine alkaloids (4–12) were isolated and the antimicrobial activity of the benzophenanthridine alkaloids is discussed in terms of structure-activity relationships. The alkaloid with the widest spectrum of activity was chelerythrine (10), followed by avicine (12) and dihydrochelerythrine (4). The minimal inhibitory concentrations of chelerythrine, of 1.50 µg/mL for all bacteria tested, and between 3.12 and 6.25 µg/mL for the yeast tested, show this compound to be a more powerful antimicrobial agent when compared with the other active alkaloids isolated from Z. rhoifolium. To verify the potential importance of the methylenedioxy group (ring A) of these alkaloids, chelerythrine was selected to represent the remainder of the benzophenanthridine alkaloids isolated in this work and was subjected to a demethylation reaction giving derivative 14. Compared to chelerythrine, the derivative (14) was less active against the tested bacteria and fungi. Kinetic measurements of the bacteriolytic activities of chelerythrine against the bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) were determined by optical density based on real time assay, suggesting that its mechanism of action is not bacteriolytic. The present study did not detect hemolytic effects of chelerythrine on erythrocytes and found a protective effect

  10. Preparation and antimicrobial activity of scleraldehyde from Schizophyllum commune.

    PubMed

    Jayakumar, Gladstone Christopher; Kanth, Swarna V; Chandrasekaran, B; Raghava Rao, J; Nair, B U

    2010-10-13

    The present study investigates the antimicrobial activity of oxidized schizophyllan (scleraldehyde) against Gram-positive and Gram-negative bacteria by diffusion and tube dilution analysis. Schizophyllan is a natural polysaccharide produced by fungi of the genus Schizophyllum. Periodate oxidation specifically cleaves the vicinal glycols in scleraldehyde to form their dialdehyde derivatives. The antibacterial activity exhibited by scleraldehyde was defined using various tests such as the disc diffusion assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). MIC and MBC values were found to be in the range of 3.0-8.0 mg/mL. Hence, the present studies establish that the scleraldehyde possesses effective antibacterial properties and can be used as a biopreservative for preservation of raw hides and skins. PMID:20817154

  11. Polyhexamethylene biguanide functionalized cationic silver nanoparticles for enhanced antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Ashraf, Sumaira; Akhtar, Nasrin; Ghauri, Muhammad Afzal; Rajoka, Muhammad Ibrahim; Khalid, Zafar M.; Hussain, Irshad

    2012-05-01

    Polyhexamethylene biguanide (PHMB), a broad spectrum disinfectant against many pathogens, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles. The particles formed were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering, electrophoretic mobility, and TEM to measure their morphology and surface chemistry. PHMB-functionalized silver nanoparticles were then evaluated for their antimicrobial activity against a gram-negative bacterial strain, Escherichia coli. These silver nanoparticles were found to have about 100 times higher bacteriostatic and bactericidal activities, compared to the previous reports, due to the combined antibacterial effect of silver nanoparticles and PHMB. In addition to other applications, PHMB-functionalized silver nanoparticles would be extremely useful in textile industry due to the strong interaction of PHMB with cellulose fabrics.

  12. An endogenous ribonuclease inhibitor regulates the antimicrobial activity of ribonuclease 7 in the human urinary tract.

    PubMed

    Spencer, John D; Schwaderer, Andrew L; Eichler, Tad; Wang, Huanyu; Kline, Jennifer; Justice, Sheryl S; Cohen, Daniel M; Hains, David S

    2014-05-01

    Recent studies stress the importance of antimicrobial peptides in protecting the urinary tract from infection. Previously, we have shown that ribonuclease 7 (RNase 7) is a potent antimicrobial peptide that has a broad-spectrum antimicrobial activity against uropathogenic bacteria. The urothelium of the lower urinary tract and intercalated cells of the kidney produce RNase 7, but regulation of its antimicrobial activity has not been well defined. Here, we characterize the expression of an endogenous inhibitor, ribonuclease inhibitor (RI), in the urinary tract and evaluate its effect on the antimicrobial activity of RNase 7. Using RNA isolated from non-infected human bladder and kidney tissue, quantitative real-time polymerase chain reaction showed that RNH1, the gene encoding RI, is constitutively expressed throughout the urinary tract. With pyelonephritis, RNH1 expression and RI peptide production significantly decrease. Immunostaining localized RI production to the umbrella cells of the bladder and intercalated cells of the renal collecting tubule. In vitro assays showed that RI bound to RNase 7 and suppressed its antimicrobial activity by blocking its ability to bind the cell wall of uropathogenic bacteria. Thus, these results demonstrate a new immunomodulatory role for RI and identified a unique regulatory pathway that may affect how RNase 7 maintains urinary tract sterility. PMID:24107847

  13. An endogenous ribonuclease inhibitor regulates the antimicrobial activity of ribonuclease 7 in the human urinary tract

    PubMed Central

    Spencer, John David; Schwaderer, Andrew L.; Eichler, Tad; Wang, Huanyu; Kline, Jennifer; Justice, Sheryl S.; Cohen, Daniel M.; Hains, David S.

    2013-01-01

    Recent studies stress the importance of antimicrobial peptides in protecting the urinary tract from infection. Previously, we have shown that ribonuclease 7 (RNase 7) is a potent antimicrobial peptide that has broad-spectrum antimicrobial activity against uropathogenic bacteria. The urothelium of the lower urinary tract and intercalated cells of the kidney produce RNase 7 but regulation of its antimicrobial activity has not been well defined. Here we characterize the expression of an endogenous inhibitor, ribonuclease inhibitor (RI), in the urinary tract and evaluate its effect on RNase 7’s antimicrobial activity. Using RNA isolated from non-infected human bladder and kidney tissue, quantitative real-time PCR showed that RNH1, the gene encoding RI, is constitutively expressed throughout the urinary tract. With pyelonephritis, RNH1 expression and RI peptide production significantly decrease. Immunostaining localized RI production to the umbrella cells of the bladder and intercalated cells of the renal collecting tubule. In vitro assays showed that RI bound to RNase 7 and suppressed its antimicrobial activity by blocking its ability to bind the cell wall of uropathogenic bacteria. Thus, these results demonstrate a new immunomodulatory role for RI and identified a unique regulatory pathway that may affect how RNase 7 maintains urinary tract sterility. PMID:24107847

  14. Cholesterol suppresses antimicrobial effect of statins

    PubMed Central

    Haeri, Mohammad Reza; White, Kenneth; Qharebeglou, Mohammad; Ansar, Malek Moein

    2015-01-01

    Objective(s): Isoprenoid biosynthesis is a key metabolic pathway to produce a wide variety of biomolecules such as cholesterol and carotenoids, which target cell membranes. On the other hand, it has been reported that statins known as inhibitors of isoprenoid biosynthesis and cholesterol lowering agents, may have a direct antimicrobial effect on the some bacteria. The exact action of statins in microbial metabolism is not clearly understood. It is possible that statins inhibit synthesis or utilization of some sterol precursor necessary for bacterial membrane integrity. Accordingly, this study was designed in order to examine if statins inhibit the production of a compound, which can be used in the membrane, and whether cholesterol would replace it and rescue bacteria from toxic effects of statins. Materials and Methods: To examine the possibility we assessed antibacterial effect of statins with different classes; lovastatin, simvastatin, and atorvastatin, alone and in combination with cholesterol on two Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and two Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria using gel diffusion assay. Results: Our results showed that all of the statins except for lovastatin had significant antibacterial property in S. aureus, E. coli, and Enter. faecalis. Surprisingly, cholesterol nullified the antimicrobial action of effective statins in statin-sensitive bacteria. Conclusion: It is concluded that statins may deprive bacteria from a metabolite responsible for membrane stability, which is effectively substituted by cholesterol. PMID:26877857

  15. Residual antimicrobial activity after canal irrigation with chlorhexidine.

    PubMed

    White, R R; Hays, G L; Janer, L R

    1997-04-01

    We previously reported that the in vitro antimicrobial activity of a 2.0% chlorhexidine endodontic irrigant was equivalent to that of 5.25% sodium hypochlorite. The purpose of this study was to determine if chlorhexidine irrigants could instill substantive antimicrobial activity in instrumented root canals in vitro. Human teeth were instrumented using 2.0% or 0.12% chlorhexidine as irrigants. After instrumentation, the root canals were filled with sterile water, and samples of the root canal fluid were absorbed with paper points at 6, 12, 24, 48, and 72 h after treatment. The paper points were assayed for antimicrobial activity by placing them on agar plate surfaces inoculated with Streptococcus mutans and measuring zones of inhibition. Antimicrobial activity was present in all 2.0% chlorhexidine-treated teeth throughout the 72-h testing period and in most teeth, in relatively lower concentrations, for 6 to 24 h after irrigation with 0.12% chlorhexidine. These results indicate that chlorhexidine instills substantive antimicrobial activity when used as an endodontic irrigant. PMID:9594771

  16. Antimicrobial peptides: a review of how peptide structure impacts antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Soares, Jason W.; Mello, Charlene M.

    2004-03-01

    Antimicrobial peptides (AMPs) have been discovered in insects, mammals, reptiles, and plants to protect against microbial infection. Many of these peptides have been isolated and studied exhaustively to decipher the molecular mechanisms that impart protection against infectious bacteria, fungi, and viruses. Unfortunately, the molecular mechanisms are still being debated within the scientific community but valuable clues have been obtained through structure/function relationship studies1. Biophysical studies have revealed that cecropins, isolated from insects and pigs, exhibit random structure in solution but undergo a conformational change to an amphipathic α-helix upon interaction with a membrane surface2. The lack of secondary structure in solution results in an extremely durable peptide able to survive exposure to high temperatures, organic solvents and incorporation into fibers and films without compromising antibacterial activity. Studies to better understand the antimicrobial action of cecropins and other AMPs have provided insight into the importance of peptide sequence and structure in antimicrobial activities. Therefore, enhancing our knowledge of how peptide structure imparts function may result in customized peptide sequences tailored for specific applications such as targeted cell delivery systems, novel antibiotics and food preservation additives. This review will summarize the current state of knowledge with respect to cell binding and antimicrobial activity of AMPs focusing primarily upon cecropins.

  17. Antimicrobial activity of human α-defensin 5 and its linear analogs: N-terminal fatty acylation results in enhanced antimicrobial activity of the linear analogs.

    PubMed

    Mathew, Basil; Nagaraj, Ramakrishnan

    2015-09-01

    Human α-defensin 5 (HD5) exhibits broad spectrum antimicrobial activity and plays an important role in mucosal immunity of the small intestine. Although there have been several studies, the structural requirements for activity and mechanism of bacterial killing is yet to be established unequivocally. In this study, we have investigated the antimicrobial activity of HD5 and linear analogs. Cysteine deletions attenuated the antibacterial activity considerably. Candidacidal activity was affected to a lesser extent. Fatty acid conjugated linear analogs showed antimicrobial activity comparable activity to HD5. Effective surface charge neutralization of bacteria was observed for HD5 as compared to the non-fatty acylated linear analogs. Our results show that HD5 and non-fatty acylated linear analogs enter the bacterial cytoplasm without causing damage to the bacterial inner membrane. Although fatty acylated peptides exhibited antimicrobial activity comparable to HD5, their mechanism of action involved permeabilization of the Escherichia coli inner membrane. HD5 and analogs had the ability to bind plasmid DNA. HD5 had greater binding affinity to plasmid DNA as compared to the analogs. The three dimensional structure of HD5 favors greater interaction with the bacterial cell surface and also with DNA. Antibacterial activity of HD5 involves entry into bacterial cytoplasm and binding to DNA which would result in shut down of the bacterial metabolism leading to cell death. We show how a moderately active linear peptide derived from the α-defensin HD5 can be engineered to enhance antimicrobial activity almost comparable to the native peptide. PMID:26206286

  18. Antimicrobial activity of tannins from Terminalia citrina.

    PubMed

    Burapadaja, S; Bunchoo, A

    1995-08-01

    Isolation of the fruit CH3OH extract of Terminalia citrina yielded five known tannins identified as corilagin (1) (3), punicalagin (2) (4), 1,3,6-tri-O-galloyl-beta-D-glucopyranose (3) (5), chebulagic acid (4) (6), and 1,2,3,4,6-penta-O-galloyl-beta-D-glucopyranose (5) (7) by comparison of their physical and spectral data with those of authentic samples. These tannins were tested for antimicrobial action. PMID:7480186

  19. Antimicrobial effect of Pistacia atlantica leaf extract

    PubMed Central

    Ali Roozegar, Mohamad; Azizi Jalilian, Farid; Reza Havasian, Mohamad; Panahi, Jafar; Pakzad, Iraj

    2016-01-01

    The antimicrobial effect of the mastic tree (Pistacia atlantica) under in vitro conditions has been reported. Therefore, it is of interest to evaluate the effect of the plant leaf extract (aqueous) on bacterial load in mouth and saliva. The leaf of the Pistacia atlantica plant was collected and cleaned, dried at 40⁰c and then powdered. The extraction was carried out using the maceration method in vacuum with the rotary evaporator device. Bacterial inhibition (Streptococcus species) by the leaf extract was studied using the disc diffusion and embedding sink diffusion methods. The values of MIC and MBC were determined. The collected data was further analyzed using t-test and repeated measure statistical tests. The disc diffusion technique showed a significant inhibitory effect for Pistacia atlantica leaf extract on S. mutans (ATCC 35668) and S. mitis (ATCC 49456) with inhibition zones of 19 and 25 millimeters, respectively. This is for the highest leaf extract concentration used in this study (p<0.01). The values of MIC and MBC for S.mutans was 60, 90 μg/ml and for S. mitis was 75, 110 μg/ml (p<0.01 significance). The leaf extract has no significant effect on S. salivarius (ATCC 13419). Thus, the antimicrobial properties of the aqueous leaf extract from Pistacia atlantica is demonstrated in this study. PMID:27212840

  20. Antimicrobial effect of Pistacia atlantica leaf extract.

    PubMed

    Ali Roozegar, Mohamad; Azizi Jalilian, Farid; Reza Havasian, Mohamad; Panahi, Jafar; Pakzad, Iraj

    2016-01-01

    The antimicrobial effect of the mastic tree (Pistacia atlantica) under in vitro conditions has been reported. Therefore, it is of interest to evaluate the effect of the plant leaf extract (aqueous) on bacterial load in mouth and saliva. The leaf of the Pistacia atlantica plant was collected and cleaned, dried at 40⁰c and then powdered. The extraction was carried out using the maceration method in vacuum with the rotary evaporator device. Bacterial inhibition (Streptococcus species) by the leaf extract was studied using the disc diffusion and embedding sink diffusion methods. The values of MIC and MBC were determined. The collected data was further analyzed using t-test and repeated measure statistical tests. The disc diffusion technique showed a significant inhibitory effect for Pistacia atlantica leaf extract on S. mutans (ATCC 35668) and S. mitis (ATCC 49456) with inhibition zones of 19 and 25 millimeters, respectively. This is for the highest leaf extract concentration used in this study (p<0.01). The values of MIC and MBC for S.mutans was 60, 90 μg/ml and for S. mitis was 75, 110 μg/ml (p<0.01 significance). The leaf extract has no significant effect on S. salivarius (ATCC 13419). Thus, the antimicrobial properties of the aqueous leaf extract from Pistacia atlantica is demonstrated in this study. PMID:27212840

  1. Selected Antimicrobial Activity of Topical Ophthalmic Anesthetics

    PubMed Central

    Reynolds, Margaret M.; Greenwood-Quaintance, Kerryl E.; Patel, Robin; Pulido, Jose S.

    2016-01-01

    Purpose Endophthalmitis is a rare complication of intravitreal injection (IVI). It is recommended that povidone-iodine be the last agent applied before IVI. Patients have reported povidone-iodine application to be the most bothersome part of IVIs. Topical anesthetics have been demonstrated to have antibacterial effects. This study compared the minimum inhibitory concentration (MIC) of topical anesthetic eye drops (proparacaine 0.5%, tetracaine 0.5%, lidocaine 2.0%) and the antiseptic, 5.0% povidone-iodine, against two organisms causing endophthalmitis after IVI. Methods Minimum inhibitory concentration values of topical anesthetics, povidone-iodine, preservative benzalkonium chloride (0.01%), and saline control were determined using five isolates of each Staphylococcus epidermidis and viridans group Streptococcus species (VGS). A broth microdilution technique was used with serial dilutions. Results Lidocaine (8.53 × 10−5mol/mL) had MICs of 4.27 to 8.53 × 10−5 mol/mL, and tetracaine (1.89 × 10−5 mol/mL) had MICs of 9.45 × 10−6 mol/mL for all isolates. Proparacaine (1.7 × 10−5 mol/mL) had MICs of 1.32 to 5.3 × 10−7 and 4.25 × 10−6 mol/mL for S. epidermidis and VGS, respectively). Benzalkonium chloride (3.52 × 10−7 mol/mL) had MICs of 1.86 × 10−9 to 1.1 × 10−8 and 4.40 × 10−8 mol/mL for S. epidermidis and VGS, respectively. Povidone-iodine (1.37 × 10−4 mol/mL) had MICs of 2.14 to 4.28 × 10−6 and 8.56 × 10−6 mol/mL for S. epidermidis and VGS, respectively. Conclusion Proparacaine was the anesthetic with the lowest MICs, lower than that of povidone-iodine. Benzalkonium chloride had lower MICs than proparacaine. All tested anesthetics and povidone-iodine inhibited growth of S. epidermidis and VGS at commercially available concentrations. Translational Relevance For certain patients, it could be possible to use topical anesthetic after povidone-iodine for comfort without inhibiting and perhaps contributing additional antimicrobial

  2. Effect of Selectively Introducing Arginine and D-Amino Acids on the Antimicrobial Activity and Salt Sensitivity in Analogs of Human Beta-Defensins

    PubMed Central

    Olli, Sudar; Rangaraj, Nandini; Nagaraj, Ramakrishnan

    2013-01-01

    We have examined the antimicrobial activity of C-terminal analogs of human β-defensins HBD-1and-3 wherein lysines have been selectively replaced by L- and D-arginines and L-isoleucine substituted with its D-enantiomer. The analogs exhibited antibacterial and antifungal activities. Physiological concentration of NaCl did not attenuate the activity of the peptides against Gram-negative bacteria considerably, while some attenuation of activity was observed against S. aureus. Variable attenuation of activity was observed in the presence of Ca2+ and Mg2+. Introduction of D-amino acids abrogated the need for a disulfide bridge for exhibiting activity. Confocal images of carboxyfluorescein (CF) labeled peptides indicated initial localization on the membrane and subsequent translocation into the cell. Analogs corresponding to cationic rich segments of human defensins substituted with L- and D-arginine, could be attractive candidates for development as future therapeutic drugs. PMID:24086767

  3. Peptides from the scorpion Vaejovis punctatus with broad antimicrobial activity.

    PubMed

    Ramírez-Carreto, Santos; Jiménez-Vargas, Juana María; Rivas-Santiago, Bruno; Corzo, Gerardo; Possani, Lourival D; Becerril, Baltazar; Ortiz, Ernesto

    2015-11-01

    The antimicrobial potential of two new non-disulfide bound peptides, named VpAmp1.0 (LPFFLLSLIPSAISAIKKI, amidated) and VpAmp2.0 (FWGFLGKLAMKAVPSLIGGNKSSSK) is here reported. These are 19- and 25-aminoacid-long peptides with +2 and +4 net charges, respectively. Their sequences correspond to the predicted mature regions from longer precursors, putatively encoded by cDNAs derived from the venom glands of the Mexican scorpion Vaejovis punctatus. Both peptides were chemically synthesized and assayed against a variety of microorganisms, including pathogenic strains from clinical isolates and strains resistant to conventional antibiotics. Two shorter variants, named VpAmp1.1 (FFLLSLIPSAISAIKKI, amidated) and VpAmp2.1 (FWGFLGKLAMKAVPSLIGGNKK), were also synthesized and tested. The antimicrobial assays revealed that the four synthetic peptides effectively inhibit the growth of both Gram-positive (Staphylococcus aureus and Streptococcus agalactiaea) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria, with MICs in the range of 2.5-24.0 μM; yeasts (Candida albicans and Candida glabrata) with MICs of 3.1-50.0 μM; and two clinically isolated strains of Mycobacterium tuberculosis-including a multi-drug resistant one- with MICs in the range of 4.8-30.5 μM. A comparison between the activities of the original peptides and their derivatives gives insight into the structural/functional role of their distinctive residues. PMID:26352292

  4. Antimicrobial activity of Gel-entrapped catechins toward oral microorganisms.

    PubMed

    Tamura, Muneaki; Saito, Hideo; Kikuchi, Kuniyoshi; Ishigami, Tomohiko; Toyama, Yoshio; Takami, Masao; Ochiai, Kuniyasu

    2011-01-01

    The oral cavity contains almost half of the commensal bacterial population present in the human body. An increase in the number of these microorganisms may result in systemic diseases such as infective endocarditis and aspiration pneumonia as well as oral infections. It is essential to control the total numbers of these microorganisms in order to suppress disease onset. Thus, we examined the antimicrobial activity of a newly developed gel-entrapped catechin (GEC) preparation against oral microorganisms. The minimum inhibitory concentration (MIC) of GEC was determined based on the relationship between a modified agar diffusion method and a broth microdilution method. GEC inhibited the growth of the Actinomyces, periodontopathic bacteria and Candida strains tested, but did not inhibit the growth of the oral streptococci that are important in the normal oral flora. Commercially available moisture gels containing antimicrobial components showed antimicrobial activity against all of the tested strains. After a series of washes and after a 24-h incubation, GEC retained the antimicrobial activity of the catechins. Catalase prevented GEC-induced growth inhibition of Actinomyces naeslundii and Streptococcus mutans suggesting that hydrogen peroxide may be involved in the antimicrobial activity of catechins. These results suggest that GEC may be useful for controlling oral microorganism populations and reducing the accumulation of dental plaque, thereby helping to prevent periodontal disease and oral candidiasis. PMID:21532150

  5. Antimicrobial effect of extracts from Chinese chive, cinnamon, and corni fructus.

    PubMed

    Mau, J; Chen, C; Hsieh, P

    2001-01-01

    Extracts were prepared from Chinese chive (Allium tuberosum), cinnamon (Cinnamomum cassia), and corni fructus (Cornus officinalis) and used to evaluate their antimicrobial activity on common foodborne microorganisms, alone and in combination. The mixed extract, consisting of three extracts in equal volumes, showed an entire antimicrobial spectrum and had excellent stability to heat, pH, and storage. The mixed extract exhibited better inhibition on growth of Escherichia coli than potassium sorbate at 2-5 mg/mL. The mixed extract inhibited the growth of Pichia membranaefaciens at levels as low as 2 mg/mL. When the mixed extract was used in foods, the expected antimicrobial effect in orange juice, pork, and milk was observed. After gel filtration chromatography, each extract was partially purified into fractions, and one fraction in each extract showed enhanced antimicrobial activity. Overall, the mixed extract was of promising potential for incorporation into various food products for which a natural antimicrobial additive is desired. PMID:11170575

  6. Effect of floral sources on the antioxidant, antimicrobial, and anti-inflammatory activities of honeys in Taiwan.

    PubMed

    Liu, Je-Ruei; Ye, Yi-Ling; Lin, Ting-Yu; Wang, Yun-Wen; Peng, Chi-Chung

    2013-08-15

    We evaluated the antioxidant, antibacterial, and anti-inflammatory activities of honey made from different floral sources, including the medicinal herb Bidens pilosa, fruit trees, Dimocarpus longan, Litchi chinensis, and Citrus maxima, the Taiwanese endemic plant Aglaia formosana, and a multifloral forest. The total phenolic and flavonoid contents of the honey made from B. pilosa were significantly higher than those of the other honeys. The honey from B. pilosa also had significantly greater scavenging activities for 1,1-diphenyl-2-picrylhydrazyl (DPPH·) and hydroxyl radical, and substantially more reducing power. In addition, the honey from B. pilosa showed greater antibacterial activity against gram-positive and gram-negative bacteria. However, B. pilosa honey showed little inhibitory activity against IL-8 secretion, whereas the other honeys did. These findings suggest that the levels of antioxidant and antibacterial activities are attributable to the total phenolic and flavonoid contents of honeys, while the IL-8 inhibition is attributable to components other than phenols. PMID:23561193

  7. Sol-gel synthesis of thorn-like ZnO nanoparticles endorsing mechanical stirring effect and their antimicrobial activities: Potential role as nano-antibiotics

    PubMed Central

    Khan, Mohd Farhan; Ansari, Akhter H.; Hameedullah, M.; Ahmad, Ejaz; Husain, Fohad Mabood; Zia, Qamar; Baig, Umair; Zaheer, Mohd Rehan; Alam, Mohammad Mezbaul; Khan, Abu Mustafa; AlOthman, Zeid A.; Ahmad, Iqbal; Ashraf, Ghulam Md; Aliev, Gjumrakch

    2016-01-01

    The effect of mechanical stirring on sol-gel synthesis of thorn-like ZnO nanoparticles (ZnO-NPs) and antimicrobial activities is successfully reported in this study. The in-house synthesized nanoparticles were characterized by XRD, SEM, TEM, FTIR, TGA, DSC and UV-visible spectroscopy. The X-Ray Diffraction analysis revealed the wurtzite crystal lattice for ZnO-NPs with no impurities present. The diametric measurements of the synthesized thorn-like ZnO-NPs (morphology assessed by SEM) were well accounted to be less than 50 nm with the help of TEM. Relative decrease in aspect ratio was observed on increasing the agitation speed. The UV-visible spectroscopy showed the absorption peaks of the ZnO-NPs existed in both UVA and UVB region. A hypsochromic shift in λmax was observed when stirring pace was increased from 500 rpm to 2000 rpm. The FTIR spectroscopy showed the absorption bands of the stretching modes of Zn-O between 500 cm−1 to 525 cm−1. The Thermal analysis studies revealed better stability for ZnO-NPs prepared at 2000 rpm (ZnO-2000 rpm). TGA revealed the weight loss between two main temperatures ranges viz. around (90 °C–120 °C) and (240 °C–280 °C). Finally, the effect of ZnO-NPs prepared at different stirring conditions on the growth of Gram-positive (Bacillus subtilis), Gram-negative (Escherichia coli) bacteria and a fungi (Candida albicans) were examined; which showed good antibacterial as well as antifungal properties. These findings introduce a simple, inexpensive process to synthesize ZnO-NPs using conventional methods without the use of sophisticated equipments and its application as a potent nano-antibiotic. PMID:27349836

  8. Sol-gel synthesis of thorn-like ZnO nanoparticles endorsing mechanical stirring effect and their antimicrobial activities: Potential role as nano-antibiotics.

    PubMed

    Khan, Mohd Farhan; Ansari, Akhter H; Hameedullah, M; Ahmad, Ejaz; Husain, Fohad Mabood; Zia, Qamar; Baig, Umair; Zaheer, Mohd Rehan; Alam, Mohammad Mezbaul; Khan, Abu Mustafa; AlOthman, Zeid A; Ahmad, Iqbal; Ashraf, Ghulam Md; Aliev, Gjumrakch

    2016-01-01

    The effect of mechanical stirring on sol-gel synthesis of thorn-like ZnO nanoparticles (ZnO-NPs) and antimicrobial activities is successfully reported in this study. The in-house synthesized nanoparticles were characterized by XRD, SEM, TEM, FTIR, TGA, DSC and UV-visible spectroscopy. The X-Ray Diffraction analysis revealed the wurtzite crystal lattice for ZnO-NPs with no impurities present. The diametric measurements of the synthesized thorn-like ZnO-NPs (morphology assessed by SEM) were well accounted to be less than 50 nm with the help of TEM. Relative decrease in aspect ratio was observed on increasing the agitation speed. The UV-visible spectroscopy showed the absorption peaks of the ZnO-NPs existed in both UVA and UVB region. A hypsochromic shift in λmax was observed when stirring pace was increased from 500 rpm to 2000 rpm. The FTIR spectroscopy showed the absorption bands of the stretching modes of Zn-O between 500 cm(-1) to 525 cm(-1). The Thermal analysis studies revealed better stability for ZnO-NPs prepared at 2000 rpm (ZnO-2000 rpm). TGA revealed the weight loss between two main temperatures ranges viz. around (90 °C-120 °C) and (240 °C-280 °C). Finally, the effect of ZnO-NPs prepared at different stirring conditions on the growth of Gram-positive (Bacillus subtilis), Gram-negative (Escherichia coli) bacteria and a fungi (Candida albicans) were examined; which showed good antibacterial as well as antifungal properties. These findings introduce a simple, inexpensive process to synthesize ZnO-NPs using conventional methods without the use of sophisticated equipments and its application as a potent nano-antibiotic. PMID:27349836

  9. A screening for antimicrobial activities of Caribbean herbal remedies

    PubMed Central

    2013-01-01

    Background The TRAMIL program aims to understand, validate and expand health practices based on the use of medicinal plants in the Caribbean, which is a “biodiversity hotspot” due to high species endemism, intense development pressure and habitat loss. The antibacterial activity was examined for thirteen plant species from several genera that were identified as a result of TRAMIL ethnopharmacological surveys or were reported in ethnobotanical accounts from Puerto Rico. The aim of this study was to validate the traditional use of these plant species for the treatment of bacterial infections, such as conjunctivitis, fever, otitis media and furuncles. Methods An agar disc diffusion assay was used to examine five bacterial strains that are associated with the reported infections, including Staphylococcus saprophyticus (ATCC 15305), S. aureus (ATCC 6341), Escherichia coli (ATCC 4157), Haemophilus influenzae (ATCC 8142), Pseudomonas aeruginosa (ATCC 7700) and Proteus vulgaris (ATCC 6896), as well as the fungus Candida albicans (ATCC 752). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined for each of the extracts that showed inhibitory activity. Results The decoctions of Pityrogramma calomelanos, Tapeinochilus ananassae, and Syzygium jambos, as well as the juice of Gossypium barbadense, showed > 20% growth inhibition against several bacteria relative to the positive control, which was the antibiotic Streptomycin. Extracts with the best antimicrobial activities were S. jambos that showed MIC = 31 μg/mL and MBC = 1.0 mg/mL against P. vulgaris and T. ananassae that showed MIC = 15 μg/mL against S. aureus. Conclusion This report confirms the traditional use of P. calomelanos for the treatment of kidney infections that are associated with stones, as well as the antimicrobial and bactericidal effects of T. ananassae against P. vulgaris and S. saprophyticus and the effects of S. jambos against S

  10. Antimicrobial, antibiofilm and cytotoxic activities of Hakea sericea Schrader extracts

    PubMed Central

    Luís, Ângelo; Breitenfeld, Luiza; Ferreira, Susana; Duarte, Ana Paula; Domingues, Fernanda

    2014-01-01

    Background: Hakea sericea Schrader is an invasive shrub in Portuguese forests. Objective: The goal of this work was to evaluate the antimicrobial activity of H. sericea extracts against several strains of microorganisms, including the ability to inhibit the formation of biofilms. Additionally the cytotoxic properties of these extracts, against human cells, were assessed. Materials and Methods: The antimicrobial activity of the methanolic extracts of H. sericea was assessed by disk diffusion assay and Minimum Inhibitory Concentration (MIC) value determination. The antibiofilm activity was determined by quantification of total biofilm biomass with crystal violet. Cytotoxicity was evaluated by hemolysis assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Results: For Gram-positive bacteria, MIC values of H. sericea methanolic extracts ranged between 0.040 and 0.625 mg/mL, whereas the fruits extract yielded the lowest MIC for several strains of microorganisms, namely, S. aureus, B. cereus, L. monocytogenes and clinical methicillin-resistant S. aureus (MRSA). Stems and fruits extract at 2.5 mg/mL effectively eradicated the biofilm of S. aureus ATCC 25923, SA 01/10 and MRSA 12/10. Regarding leaves extract, hemolysis was not observed, and in the case of stems and fruits, hemolysis was verified only for higher concentrations, suggesting its low toxicity. Fruits extract presented no toxic effect to normal human dermal fibroblasts (NHDF) cells however for concentrations of 0.017 and 0.008 mg/mL this extract was able to decrease human breast adenocarcinoma cells (MCF-7) viability in about 60%, as MTT test results had confirmed. This is a clearly demonstrator of the cytotoxicity of this extract against MCF-7 cells. PMID:24914310

  11. Synthesis and Antimicrobial Activity of Silver-Doped Hydroxyapatite Nanoparticles

    PubMed Central

    Ciobanu, Carmen Steluta; Iconaru, Simona Liliana; Chifiriuc, Mariana Carmen; Costescu, Adrian; Le Coustumer, Philippe; Predoi, Daniela

    2013-01-01

    The synthesis of nanosized particles of Ag-doped hydroxyapatite with antibacterial properties is of great interest for the development of new biomedical applications. The aim of this study was the evaluation of Ca10−xAgx(PO4)6(OH)2 nanoparticles (Ag:HAp-NPs) for their antibacterial and antifungal activity. Resistance to antimicrobial agents by pathogenic bacteria has emerged in the recent years and became a major health problem. Here, we report a method for synthesizing Ag doped nanocrystalline hydroxyapatite. A silver-doped nanocrystalline hydroxyapatite was synthesized at 100°C in deionised water. Also, in this paper Ag:HAp-NPs are evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria and fungal strains. The specific antimicrobial activity revealed by the qualitative assay is demonstrating that our compounds are interacting differently with the microbial targets, probably due to the differences in the microbial wall structures. PMID:23509801

  12. Phytochemical and antimicrobial activities of Himalayan Cordyceps sinensis (Berk.) Sacc.

    PubMed

    Mamta; Mehrotra, Shubhi; Amitabh; Kirar, Vandana; Vats, Praveen; Nandi, Shoma Paul; Negi, P S; Misra, Kshipra

    2015-01-01

    This study evaluated the phytochemical and antimicrobial activities and also quantified bioactive nucleoside using high performance thin layer chromatography (HPTLC) of five extracts of Indian Himalayan Cordyceps sinensis prepared with different solvents employing accelerated solvent extraction (ASE) technique. The phytochemical potential of these extracts was quantified in terms of total phenolic and total flavonoid content while antioxidant activities were determined by 1,1-diphenyl-2-pycryl-hydrazyl (DPPH) and 2,2 -azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric-reducing antioxidant power (FRAP) assays. Total reducing power (TRP) was determined by converting iron (III) into iron (II) reduction assay. CS(50%Alc) (15.1 ± 0.67mg/g of dry extract) and CS(100%Alc) (19.3 ± 0.33 mg/g of dry extract) showed highest phenolic and flavonoid content, respectively while CS(Aq) extract showed maximum antioxidant activity and the highest concentration of the three nucleosides (adenine 12.8 ± 0.49 mg/g, adenosine 0.36 ± 0.28 mg/g and uracil 0.14 ± 0.36 mg/g of dry extract) determined by HPTLC. The evaluation of extracts for antimicrobial activity against gram-negative and gram-positive bacterial strains showed CS(25%Alc), CS(75%Alc) and CS(100%Alc) extract to be more effective against E. coli, P. aerugenosa and B. subtilis giving 9, 7 and 6.5 mm of zone of inhibition (ZOI) in 93.75, 93.75 and 45 μg concentration, respectively, whereas CS(Aq) extract showed minimal inhibition against these. PMID:25675710

  13. Antimicrobial and antioxidant activities of alcoholic extracts obtained from vegetative organs of A. retroflexus.

    PubMed

    Marinaş, Ioana Cristina; Chifiriuc, Carmen; Oprea, Eliza; Lazăr, Veronica

    2014-01-01

    In vitro antimicrobial and antioxidant activities of Amaranthus retroflexus leaves and inflorescence alcoholic (ethanol 70%) extracts of various concentrations ranging from 0.78 to 400 μL/ml were analyzed on different clinical and reference bacterial strains (Staphylococcus aureus, Bacillus subtills, Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii) and fungal strains (Candida albicans, C. famata, C. utilis, Saccharomyces cerevisiae) using agar disk diffusion method and broth dilution method (MIC determination) for antimicrobial activity and TEAC (Trolox capacity) assay for the evaluation of the antioxidant activity. The adapted diffusion method was used to test the antimicrobial effect of the extracts separately and in combination with a range of standard antibiotics, in order to evidence any synergic effects of A. retroflexus extracts on the antibiotics activity. The extracts showed the highest inhibitory effect against K. pneumoniae and B. subtilis with no activity against S. aureus among the bacterial strains, while in case of the fungal strains the most intensive effect was exhibited against C. famata by both extracts. The A. retroflexus leaves extract improved the ciprofloxacin and ticarcillin-clavulanic acid activity towards the P. aeruginosa clinical strain. The inflorescences extract significantly increased chloramphenicol activity on B. subtilis strain. The antioxidant activity assay showed that the studied extracts exhibited the ability to neutralize the free radicals leading to the conclusion that the tested extracts bear compounds with a broad spectrum of antimicrobial and antioxidant activity that could represent a potential alternative for treating various infectious diseases. PMID:25518569

  14. Antimicrobial effect of garlic (Allium sativum).

    PubMed

    Goncagul, Gulsen; Ayaz, Erol

    2010-01-01

    Medicinal plants like pumpkin seed, thyme, onion, Nigella sativa, lemon balm, and stinging nettle are used extensively today. One of these plants used most intensively and widespread is garlic. In this context, fresh shape, powder state and oil of garlic have been used all around the world, especially in Far East for centuries. It is scientifically proven that garlic is effectively used in cardiovascular diseases as a regulator of blood pressure, with dropper effects on glycaemia and high blood cholesterol, against bacterial, viral, mycotic and parasitic infections. It's also known that garlic is a wonderful plant having the properties of empowering immune system, anti-tumour and antioxidant effects. In this article, the summary of properties of garlic and its use against bacterial diseases is given. This article is a short review of recent patents on antimicrobial effect of garlic. PMID:19929845

  15. Structure-antimicrobial activity relationship between pleurocidin and its enantiomer

    PubMed Central

    Lee, Juneyoung

    2008-01-01

    To develop novel antibiotic peptides useful as therapeutic drugs, the enantiomeric analogue of pleurocidin (Ple), which is a well known 25-mer antimicrobial peptide, was designed for proteolytic resistance by D-amino acids substitution. The proteolytic resistance was confirmed by using HPLC after the digestion with various proteases. To investigate the antibiotic effect of L- and D-Ple, the antibacterial activity and hemolytic effect were tested against human erythrocytes. The D-Ple showed a decreased antibacterial activity and a dramatically decreased hemolytic activity compared with L-Ple. The hemolytic effect of analogue was further confirmed by using calcein leakage measurement with liposome. To elucidate these results, the secondary structure of the peptides was investigated by using circular dichroism spectroscopy. The results revealed that D-Ple, as well as L-Ple, had typical α-helical structures which were mirror images, with a different helicity. These results suggested that the discrepancy of the structure between the two peptides made their antibacterial activity distinct. PMID:18779649

  16. Synthesis and antimicrobial activity of gold/silver-tellurium nanostructures.

    PubMed

    Chang, Hsiang-Yu; Cang, Jinshun; Roy, Prathik; Chang, Huan-Tsung; Huang, Yi-Cheng; Huang, Chih-Ching

    2014-06-11

    Gold-tellurium nanostructures (Au-Te NSs), silver-tellurium nanostructures (Ag-Te NSs), and gold/silver-tellurium nanostructures (Au/Ag-Te NSs) have been prepared through galvanic reactions of tellurium nanotubes (Te NTs) with Au(3+), Ag(+), and both ions, respectively. Unlike the use of less environmentally friendly hydrazine, fructose as a reducing agent has been used to prepare Te NTs from TeO2 powders under alkaline conditions. The Au/Ag-Te NSs have highly catlaytic activity to convert nonfluorescent Amplex Red to form fluorescent product, revealing their great strength of generating reactive oxygen species (ROS). Au/Ag-Te NSs relative to the other two NSs exhibit greater antimicrobial activity toward the growth of E. coli, S. enteritidis, and S. aureus; the minimal inhibitory concentration (MIC) values of Au/Ag-Te NSs were much lower (>10-fold) than that of Ag-Te NSs and Au-Te NSs. The antibacterial activity of Au/Ag-Te NSs is mainly due to the release of Ag(+) ions and Te-related ions and also may be due to the generated ROS which destroys the bacteria membrane. In vitro cytotoxicity and hemolysis analyses have revealed their low toxicity in selected human cell lines and insignificant hemolysis in red blood cells. In addition, inhibition zone measurements using a Au/Ag-Te NSs-loaded konjac jelly film have suggested that it has great potential in practial application such as wound dressing for reducing bacterial wound infection. Having great antibacterial activitiy and excellent biocompatibility, the low-cost Au/Ag-Te NSs hold great potential as effective antimicrobial drugs. PMID:24832728

  17. Antimicrobial activity of submicron glass fibres incorporated as a filler to a dental sealer.

    PubMed

    Esteban-Tejeda, L; Cabal, B; Torrecillas, R; Prado, C; Fernandez-Garcia, E; López-Piriz, R; Quintero, F; Pou, J; Penide, J; Moya, J S

    2016-01-01

    Two types of antimicrobial glass fibers containing ZnO and CaO, with diameters ranging from tens of nanometers to 1 µm, were successfully fabricated by a laser spinning technique. The antimicrobial performance was corroborated according to ISO 20743:2013, by using gram-negative (Escherichia coli) and gram-positive (Streptococcus oralis, Streptococcus mutans and Staphylococcus aureus) bacteria, and yeast (Candida krusei) (more than 3 logs of reduction). The metabolic activity and endosomal system of eukaryotic cells were not altered by using eluents of CaO glass submicrometric fibers and ZnO fibers at 1 : 10 dilution as cellular media (viability rates over 70%). A dental material was functionalized by embedding ZnO nanofibers above the percolation threshold (20% wt), creating a three-dimensional (3D) fiber network that added an antimicrobial profile. This new ZnO glass fiber composite is proved non-cytotoxic and preserved the antimicrobial effect after immersion in human saliva. This is the first time that a fiber-reinforced liner with strong antimicrobial-activity has been created to prevent secondary caries. The potential of developing new fiber-reinforced composites (FRCs) with antimicrobial properties opens up an extensive field of dental applications where most important diseases have an infectious origin. PMID:27509353

  18. [Isolation and antimicrobial activities of actinomycetes from vermicompost].

    PubMed

    Wang, Xue-jun; Yan, Shuang-lin; Min, Chang-li; Yang, Yan

    2015-02-01

    In this paper, actinomycetes were isolated from vermicompost by tablet coating method. Antimicrobial activities of actinomycetes were measured by the agar block method. Strains with high activity were identified based on morphology and biochemical characteristics, as well as 16S rDNA gene sequence analysis. The results showed that 26 strains of actinomycetes were isolated, 16 of them had antimicrobial activities to the test strains which accounts for 61.54% of all strains. Among the 16 strains, the strain QYF12 and QYF22 had higher antimicrobial activity to Micrococcus luteus, with a formed inhibition zone of 27 mm and 31 mm, respectively. While the strain QYF26 had higher antimicrobial activity to Bacillus subtilis, and the inhibition zone diameter was 21 mm. Based on the identification of strains with high activity, the strain QYF12 was identified as Streptomyces chartreusis, the strain QYF22 was S. ossamyceticus and the strain QYF26 was S. gancidicus. This study provided a theoretical basis for further separate antibacterial product used for biological control. PMID:26137678

  19. Inducible ASABF-Type Antimicrobial Peptide from the Sponge Suberites domuncula: Microbicidal and Hemolytic Activity in Vitro and Toxic Effect on Molluscs in Vivo†

    PubMed Central

    Wiens, Matthias; Schröder, Heinz C.; Korzhev, Michael; Wang, Xiao-Hong; Batel, Renato; Müller, Werner E. G.

    2011-01-01

    Since sponges, as typical filter-feeders, are exposed to a high load of attacking prokaryotic and eukaryotic organisms, they are armed with a wide arsenal of antimicrobial/cytostatic low-molecular-weight, non-proteinaceous bioactive compounds. Here we present the first sponge agent belonging to the group of ASABF-type antimicrobial peptides. The ASABF gene was identified and cloned from the demosponge Suberites domuncula. The mature peptide, with a length of 64 aa residues has a predicted pI of 9.24, and comprises the characteristic CSα β structural motif. Consequently, the S. domuncula ASABF shares high similarity with the nematode ASABFs; it is distantly related to the defensins. The recombinant peptide was found to display besides microbicidal activity, anti-fungal activity. In addition, the peptide lyses human erythrocytes. The expression of ASABF is upregulated after exposure to the apoptosis-inducing agent 2,2′-dipyridyl. During the process of apoptosis of surface tissue of S. domuncula, grazing gastropods (Bittium sp.) are attracted by quinolinic acid which is synthesized through the kynurenine pathway by the enzyme 3-hydroxyanthranilate 3,4-dioxygenase (HAD). Finally, the gastropods are repelled from the sponge tissue by the ASABF. It is shown that the effector peptide ASABF is sequentially expressed after the induction of the HAD gene and a caspase, as a central enzyme executing apoptosis. PMID:22073005

  20. Inducible ASABF-type antimicrobial peptide from the sponge Suberites domuncula: microbicidal and hemolytic activity in vitro and toxic effect on molluscs in vivo.

    PubMed

    Wiens, Matthias; Schröder, Heinz C; Korzhev, Michael; Wang, Xiao-Hong; Batel, Renato; Müller, Werner E G

    2011-01-01

    Since sponges, as typical filter-feeders, are exposed to a high load of attacking prokaryotic and eukaryotic organisms, they are armed with a wide arsenal of antimicrobial/cytostatic low-molecular-weight, non-proteinaceous bioactive compounds. Here we present the first sponge agent belonging to the group of ASABF-type antimicrobial peptides. The ASABF gene was identified and cloned from the demosponge Suberites domuncula. The mature peptide, with a length of 64 aa residues has a predicted pI of 9.24, and comprises the characteristic CSα β structural motif. Consequently, the S. domuncula ASABF shares high similarity with the nematode ASABFs; it is distantly related to the defensins. The recombinant peptide was found to display besides microbicidal activity, anti-fungal activity. In addition, the peptide lyses human erythrocytes. The expression of ASABF is upregulated after exposure to the apoptosis-inducing agent 2,2'-dipyridyl. During the process of apoptosis of surface tissue of S. domuncula, grazing gastropods (Bittium sp.) are attracted by quinolinic acid which is synthesized through the kynurenine pathway by the enzyme 3-hydroxyanthranilate 3,4-dioxygenase (HAD). Finally, the gastropods are repelled from the sponge tissue by the ASABF. It is shown that the effector peptide ASABF is sequentially expressed after the induction of the HAD gene and a caspase, as a central enzyme executing apoptosis. PMID:22073005

  1. Self-assembly of cationic multidomain peptide hydrogels: supramolecular nanostructure and rheological properties dictate antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Jiang, Linhai; Xu, Dawei; Sellati, Timothy J.; Dong, He

    2015-11-01

    Hydrogels are an important class of biomaterials that have been widely utilized for a variety of biomedical/medical applications. The biological performance of hydrogels, particularly those used as wound dressing could be greatly advanced if imbued with inherent antimicrobial activity capable of staving off colonization of the wound site by opportunistic bacterial pathogens. Possessing such antimicrobial properties would also protect the hydrogel itself from being adversely affected by microbial attachment to its surface. We have previously demonstrated the broad-spectrum antimicrobial activity of supramolecular assemblies of cationic multi-domain peptides (MDPs) in solution. Here, we extend the 1-D soluble supramolecular assembly to 3-D hydrogels to investigate the effect of the supramolecular nanostructure and its rheological properties on the antimicrobial activity of self-assembled hydrogels. Among designed MDPs, the bactericidal activity of peptide hydrogels was found to follow an opposite trend to that in solution. Improved antimicrobial activity of self-assembled peptide hydrogels is dictated by the combined effect of supramolecular surface chemistry and storage modulus of the bulk materials, rather than the ability of individual peptides/peptide assemblies to penetrate bacterial cell membrane as observed in solution. The structure-property-activity relationship developed through this study will provide important guidelines for designing biocompatible peptide hydrogels with built-in antimicrobial activity for various biomedical applications.Hydrogels are an important class of biomaterials that have been widely utilized for a variety of biomedical/medical applications. The biological performance of hydrogels, particularly those used as wound dressing could be greatly advanced if imbued with inherent antimicrobial activity capable of staving off colonization of the wound site by opportunistic bacterial pathogens. Possessing such antimicrobial properties would

  2. Phytochemical, antimicrobial, and antioxidant activities of different citrus juice concentrates.

    PubMed

    Oikeh, Ehigbai I; Omoregie, Ehimwenma S; Oviasogie, Faith E; Oriakhi, Kelly

    2016-01-01

    The search for new antimicrobial compounds is ongoing. Its importance cannot be overemphasized in an era of emerging resistant pathogenic organisms. This study therefore investigated the phytochemical composition and antioxidant and antimicrobial activities of different citrus juice concentrates. Fruit juices of Citrus tangerine (tangerine), Citrus paradisi (grape), Citrus limon (lemon), and Citrus aurantifolia (lime) were evaluated. Antimicrobial activities against five bacterial and three fungal strains were evaluated. The results revealed the presence of alkaloids, flavonoids, steroids, terpenoids, saponins, cardiac glycosides, and reducing sugars in all the juice concentrates. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging capacities varied with tangerine and grape juices having better scavenging capacities than lemon and lime juices. Grape juice was observed to have a significantly higher (P < 0.05) ferric-reducing antioxidant potential (FRAP) value (364.2 ± 10.25 μmol/L Fe(II)/g of the extract) than the reference antioxidant, ascorbic acid (312.88 ± 5.61 μmol/L). Antimicrobial studies revealed differential antimicrobial activities against different microbial strains. Zones of inhibition ranging from 4 to 26 mm were observed for the antibacterial tests with 0-24 mm for antifungal test. Minimum inhibitory concentrations (MIC) and minimum bacteriostatic concentrations (MBC) for concentrates against bacterial strains ranged from 12.5 to 200 μg/mL. Lemon and lime juice concentrates had lower MIC and MBC values with orange and tangerine having the highest values. Minimum fungicidal concentrations ranged from 50 to 200 μg/mL. The results of this study suggest that these juice concentrates may have beneficial antimicrobial roles that can be exploited in controlling unwanted microbial growth. PMID:26788316

  3. Antimicrobial activity of plant compounds against Salmonella Typhimurium DT104 in ground pork and the influence of heat and storage on the antimicrobial activity.

    PubMed

    Chen, Cynthia H; Ravishankar, Sadhana; Marchello, John; Friedman, Mendel

    2013-07-01

    Salmonella enterica is a predominant foodborne pathogen that causes diarrheal illness worldwide. A potential method of inhibiting pathogenic bacterial growth in meat is through the introduction of plant-derived antimicrobials. The objectives of this study were to investigate the influence of heat (70°C for 5 min) and subsequent cold storage (4°C up to 7 days) on the effectiveness of oregano and cinnamon essential oils and powdered olive and apple extracts against Salmonella enterica serovar Typhimurium DT104 in ground pork and to evaluate the activity of the most effective antimicrobials (cinnamon oil and olive extract) at higher concentrations in heated ground pork. The surviving Salmonella populations in two groups (heated and unheated) of antimicrobial-treated pork were compared. Higher concentrations of the most effective compounds were then tested (cinnamon oil at 0.5 to 1.0% and olive extract at 3, 4, and 5%) against Salmonella Typhimurium in heated ground pork. Samples were stored at 4°C and taken on days 0, 3, 5, and 7 for enumeration of survivors. The heating process did not affect the activity of antimicrobials. Significant 1.3- and 3-log reductions were observed with 1.0% cinnamon oil and 5% olive extract, respectively, on day 7. The minimum concentration required to achieve . 1-log reduction in Salmonella population was 0.8% cinnamon oil or 4% olive extract. The results demonstrate the effectiveness of these antimicrobials against multidrug-resistant Salmonella Typhimurium in ground pork and their stability during heating and cold storage. The most active formulations have the potential to enhance the microbial safety of ground pork. PMID:23834804

  4. Antimicrobial Activity of Bacteriocins and Their Applications

    NASA Astrophysics Data System (ADS)

    Drosinos, Eleftherios H.; Mataragas, Marios; Paramithiotis, Spiros

    Bacteriocins are peptides or proteins that exert an antimicrobial action against a range of microorganisms. Their production can be related to the antagonism within a certain ecological niche, as the producer strain, being itself immune to its action, generally gains a competitive advantage. Many Gram-positive and Gram-negative microorganisms have been found to produce bacteriocins. The former, and especially the ones produced by lactic acid bacteria, has been the field of intensive research during the last decades mainly due to their properties that account for their suitability in food preservation and the benefits arising from that, and secondarily due to the broader inhibitory spectrum compared to the ones produced by Gramnegative microorganisms.

  5. Antimicrobial effect of nylon fiber immersed with nano-silver

    NASA Astrophysics Data System (ADS)

    Haryono, Agus; Harmami, Sri Budi; Sondari, Dewi

    2010-05-01

    The development of new products based on the immobilization of nanoparticles on fibers has recently received a growing interest from both the academic and industrial sectors. A wide range of nanoparticles and nano-structures can be immobilized on fibers, which brings new properties to the final product. In the present work, silver nanoparticle was immobilized on nylon fibers by immersed deposition method as an antimicrobial agent. Silver colloid was produced by chemical reduction of silver salt (silver nitrate) solution, in the presence of sodium citrate. Synthesis of silver colloid was carried out by using chemical reduction method at temperature of 95 and 100°C. The mixture was heated until color changed into pale yellow. UV-Vis spectrometry indicated formation of silver nanoparticles. UV-Vis analysis was reported that the absorption spectrum of silver nanoparticles showed a maximum between 420 and 450 nm. Characterization of silver nanoparticles was conducted using Fourier Transformed Infra Red (FTIR) spectroscopy, UV-Vis spectroscopy, particle size analyzer (PSA), and scanning electron microscope (SEM). It was found that silver nanoparticles forms aggregates on the surface of fiber, during deposition process. The size of aggregates varied from 19.9 +/- 4.8 nm to 49.5 +/- 12.5 nm. To evaluate the antimicrobial effects against microorganisms, we used representative microorganisms S. aureus. Silver nanoparticles showed antimicrobial activity reducing bacterial growth.

  6. [Antimicrobially effective compounded medications. Clinical value and critical comments].

    PubMed

    Eifler-Bollen, R; Fluhr, J W

    2005-08-01

    Triphenyl-methan dyes, traditionally used in dermatology should be reevaluated with caution. Their use should be limited due to the uncertain pharmacological-toxicological risk-benefit ratio and the lack of pharmacological quality of the raw substances. Sometimes antimicrobial activity is insufficient and the cytotoxic effects, along with the inhibition of wound healing, make these dyes less suitable for topical treatment in dermatology. Chinolinolsulfat (Chinosol) and Clioquinol should be used in low concentrations and only on small areas. Due to their negative benefit-risk profile ethracidinlactate-monohydrate (Rivanol) and phenylmercuri-borate (Mercuchrom) should not be used as topical antimicrobial substances. The present publication is intended to give practical recommendations on compounded medications for topical antimicrobial use. Even though some of the cited compounds must be considered critically, we recommend the topical use of chlorhexidine salts, polihexanide, triclosan, polyvidone iodide and silver compounds. Useful standardised compounded formulations containing these four groups are listed in the NRF (Neues Rezeptur Formularium: New German Pharmacopoeia for compounded medication). PMID:15933865

  7. Thymus vulgaris essential oil: chemical composition and antimicrobial activity.

    PubMed

    Borugă, O; Jianu, C; Mişcă, C; Goleţ, I; Gruia, A T; Horhat, F G

    2014-01-01

    The study was designed to determine the chemical composition and antimicrobial properties of the essential oil of Thymus vulgaris cultivated in Romania. The essential oil was isolated in a yield of 1.25% by steam distillation from the aerial part of the plant and subsequently analyzed by GC-MS. The major components were p-cymene (8.41%), γ-terpinene (30.90%) and thymol (47.59%). Its antimicrobial activity was evaluated on 7 common food-related bacteria and fungus by using the disk diffusion method. The results demonstrate that the Thymus vulgaris essential oil tested possesses strong antimicrobial properties, and may in the future represent a new source of natural antiseptics with applications in the pharmaceutical and food industry. PMID:25870697

  8. Phytochemical screening and in vitro antimicrobial activity of Thymus lanceolatus Desf. from Algeria

    PubMed Central

    Benbelaïd, Fethi; Khadir, Abdelmounaïm; Abdoune, Mohamed Amine; Bendahou, Mourad

    2013-01-01

    Objective To investigate the antimicrobial activity of an endemic Thyme, Thymus lanceolatus (T. lanceolatus), against a large number of pathogens. Methods Four solvent extracts were evaluated for antimicrobial activity using disc diffusion method and MIC determination on twenty-one strains. Results T. lanceolatus extracts showed a broad-spectrum antimicrobial activity, especially ethanol extract with inhibition zone diameters ranging from 14 to 32 mm, and MIC values from 0.052 to 0.500 mg/mL. Chloroform extract was more active against Gram-positive bacteria, since it has an inhibitory potency on Staphylococcus aureus and Enterococcus faecalis at only 31 µg/mL. While, hexane and water extracts were less effective since they were inactive against several strains. Conclusions The findings of this study indicate that T. lanceolatus has a strong antimicrobial potential, which justifies its use in folk medicine for treatment of infectious diseases. Since this species is poorly investigated, further refined studies on it pure secondary metabolites are needed and very important, in the perspective to identify new antimicrobial molecules from this endemic plant.

  9. Antioxidant and antimicrobial activities of rosemary extracts linked to their polyphenol composition.

    PubMed

    Moreno, Silvia; Scheyer, Tamara; Romano, Catalina S; Vojnov, Adrián A

    2006-02-01

    Rosmarinus officinalis extracts were investigated by a combination of bioassays and biochemical analysis to identify bioactive compounds. The 2,2-diphenyl-2-picrylhydracyl hydrate (DPPH) radical scavenging method, Folin-Ciocaulteau method and HPLC chromatography were used to study the distribution and levels of antioxidants (AOXs). Antimicrobial activity analysis was carried out using the disk diffusion and broth dilution techniques. A good correlation between the AOX activities and total phenol content in the extracts was found. Although all rosemary extracts showed a high radical scavenging activity, a different efficacy as antimicrobial agent was observed. Methanol extract containing 30% of carnosic acid, 16% of carnosol and 5% of rosmarinic acid was the most effective antimicrobial against Gram positive bacteria (minimal inhibition concentration, MIC, between 2 and 15 mug/ml), Gram negative bacteria (MIC between 2 and 60 mug/ml) and yeast (MIC of 4 mug/ml). By contrast, water extract containing only 15% of rosmarinic acid showed a narrow activity. MIC value of the methanol and water extracts is in a good correlation with the values obtained with pure carnosic acid and rosmarinic acid, respectively. Therefore, our results suggested that the antimicrobial rosemary extracts efficacy was associated with their specific phenolic composition. Carnosic acid and rosmarinic acid may be the main bioactive antimicrobial compounds present in rosemary extracts. From a practical point of view, rosemary extract may be a good candidate for functional foods as well as for pharmaceutical plant-based products. PMID:16390832

  10. In vitro antimicrobial activity of five essential oils on multidrug resistant Gram-negative clinical isolates

    PubMed Central

    Sakkas, Hercules; Gousia, Panagiota; Economou, Vangelis; Sakkas, Vassilios; Petsios, Stefanos; Papadopoulou, Chrissanthy

    2016-01-01

    Aim/Background: The emergence of drug-resistant pathogens has drawn attention on medicinal plants for potential antimicrobial properties. The objective of the present study was the investigation of the antimicrobial activity of five plant essential oils on multidrug resistant Gram-negative bacteria. Materials and Methods: Basil, chamomile blue, origanum, thyme, and tea tree oil were tested against clinical isolates of Acinetobacter baumannii (n = 6), Escherichia coli (n = 4), Klebsiella pneumoniae (n = 7), and Pseudomonas aeruginosa (n = 5) using the broth macrodilution method. Results: The tested essential oils produced variable antibacterial effect, while Chamomile blue oil demonstrated no antibacterial activity. Origanum, Thyme, and Basil oils were ineffective on P. aeruginosa isolates. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration values ranged from 0.12% to 1.50% (v/v) for tea tree oil, 0.25-4% (v/v) for origanum and thyme oil, 0.50% to >4% for basil oil and >4% for chamomile blue oil. Compared to literature data on reference strains, the reported MIC values were different by 2SD, denoting less successful antimicrobial activity against multidrug resistant isolates. Conclusions: The antimicrobial activities of the essential oils are influenced by the strain origin (wild, reference, drug sensitive, or resistant) and it should be taken into consideration whenever investigating the plants’ potential for developing new antimicrobials. PMID:27366345

  11. [Current animal feeds with antimicrobial activity].

    PubMed

    Drumev, D

    1981-01-01

    Among the growth-promoting substances and factors contributing to fodder utilization in growing farm animals, also called nutritive, ergotropic means, the antibiotics and some synthetic chemotherapeutics have acquired special importance. To avoid the hazardous effect in humans consuming products of animal origin there should be no residual amounts of these stimulating agents in such products. That is why it has been assumed in a number of countries to use for the same purpose only nutritive means that are not applied as therapeutic agents. Such means should neither induce resistence to antibiotics and chemotherapeutics in microorganism nor should they be resorbed by the alimentary tract (or resorption should be negligible) or they are rapidly eliminated from the animal body, leaving no residual amounts. They should likewise act chiefly against gram-positive organisms, inducing no allergic reactions in the animals. Described are the following nutritive antibiotics: flavophospholipol (bambermycin, menomycin--flavomycin, producing a nutritive effect also in ruminants with a developed forestomach, and rebuilds sensitivity in antibiotic-resistant organisms belonging to Enterobacteriaceae), avoparcin (avotan--also active in ruminants with a developed forestomach), virginiamycin (staphylomycin--escalin, stafac), zincbacitracin (bacipharmin, baciferm), grisin (kormogrisin, of a road spectrum, with an antimycotic effect, raising the fertilization rate and activating phagocitosis), vitamycin-A (vitamycin--active also at retinol deficiency, lambdamycin, nosiheptide (primofax), efrotomycin. Due consideration is given to such chemotherapeutics as nitrovin (payson, paison), carbadox (mecadox, fortigro, of a broad spectrum retained for a longer period in the body of pigs), olaquindox (bio-N-celbar--of a broad spectrum, particularly with regard to gram-negative organisms, applied at present as a therapeutic and prophylactic preparation), cyadox (with a broad sprectrum). The

  12. Antimicrobial activity of Amazonian oils against Paenibacillus species.

    PubMed

    Santos, Roberto Christ Vianna; dos Santos Alves, Camilla Filippi; Schneider, Taiane; Lopes, Leonardo Quintana Soares; Aurich, Carlos; Giongo, Janice Luehring; Brandelli, Adriano; de Almeida Vaucher, Rodrigo

    2012-03-01

    The Gram-positive, spore-forming bacterium Paenibacillus larvae is the primary bacterial pathogen of honeybee brood and the causative agent of American foulbrood disease (AFB). One of the feasible alternative treatments being used for their control of this disease is essential oils. In this study in vitro antimicrobial activity of Andiroba and Copaíba essential oils against Paenibacillus species, including P. larvae was evaluated. Minimal inhibitory concentration (MIC) in Mueller-Hinton broth by the microdilution method was assessed. Andiroba registered MIC values of 1.56-25%, while the MICs values obtained for Copaíba oil were of 1.56-12.5%. In order to determine the time-response effect of essential oils on P. larvae, this microorganism was exposed to the oils for up to 48 h. After 24 h treatment with Andiroba oil and after 48 h treatment with Copaíba oil no viable cells of P. larvae ATCC 9545 were observed. The possible toxic effect of essential oils were assessed by the spraying application method of the same concentrations of MICs. Bee mortality was evident only in treatment with Andiroba oil and the Copaíba oil shows no toxic effects after 10 days of observation. Taking together ours results showed for the first time that these oils presented a high activity against Paenibacillus species showing that Copaíba oil may be a candidate for the treatment or prevention of AFB. PMID:22200645

  13. Antimicrobial Activity and Phytochemical Analysis of Organic Extracts from Cleome spinosa Jaqc.

    PubMed Central

    da Silva, Ana P. Sant'Anna; Nascimento da Silva, Luís C.; Martins da Fonseca, Caíque S.; de Araújo, Janete M.; Correia, Maria T. dos Santos; Cavalcanti, Marilene da Silva; Lima, Vera L. de Menezes

    2016-01-01

    Due to the use of Cleome spinosa Jacq. (Cleomaceae) in traditional medicine against inflammatory and infectious processes, this study evaluated the in vitro antimicrobial potential and phytochemical composition of extracts from its roots and leaves. From leaves (L) and roots (R) of C. spinosa different extracts were obtained (cyclohexane: ChL and ChR; chloroform: CL and CR; ethyl acetate: EAL and EAR, methanol: ML and MR). The antimicrobial activity was evaluated by the broth microdilution method to obtain the minimum inhibitory (MIC) and microbicidal (MMC) concentrations against 17 species, including bacteria and yeasts. Additionally, antimicrobial and combinatory effects with oxacillin were assessed against eight clinical isolates of Staphylococcus aureus. All C. spinosa extracts showed a broad spectrum of antimicrobial activity, as they have inhibited all tested bacteria and yeasts. This activity seems to be related to the phytochemicals (flavonoid, terpenoids and saponins) detected into the extracts of C. spinosa. ChL and CL extracts were the most actives, with MIC less than 1 mg/mL against S. aureus, Bacillus subtilis, and Micrococcus luteus. It is important to note that these concentrations are much lower than their 50% hemolysis concentration (HC50) values. Strong correlations were found between the average MIC against S. aureus and their phenolic (r = −0.89) and flavonoid content (r = −0.87), reinforcing the possible role of these metabolite classes on the antimicrobial activity of C. spinosa derived extracts. Moreover, CL and CR showed the best inhibitory activity against S. aureus clinical isolates, they also showed synergistic action with oxacillin against all these strains (at least at one combined proportion). These results encourage the identification of active substances which could be used as lead(s) molecules in the development of new antimicrobial drugs. PMID:27446005

  14. Antimicrobial Activity and Phytochemical Analysis of Organic Extracts from Cleome spinosa Jaqc.

    PubMed

    da Silva, Ana P Sant'Anna; Nascimento da Silva, Luís C; Martins da Fonseca, Caíque S; de Araújo, Janete M; Correia, Maria T Dos Santos; Cavalcanti, Marilene da Silva; Lima, Vera L de Menezes

    2016-01-01

    Due to the use of Cleome spinosa Jacq. (Cleomaceae) in traditional medicine against inflammatory and infectious processes, this study evaluated the in vitro antimicrobial potential and phytochemical composition of extracts from its roots and leaves. From leaves (L) and roots (R) of C. spinosa different extracts were obtained (cyclohexane: ChL and ChR; chloroform: CL and CR; ethyl acetate: EAL and EAR, methanol: ML and MR). The antimicrobial activity was evaluated by the broth microdilution method to obtain the minimum inhibitory (MIC) and microbicidal (MMC) concentrations against 17 species, including bacteria and yeasts. Additionally, antimicrobial and combinatory effects with oxacillin were assessed against eight clinical isolates of Staphylococcus aureus. All C. spinosa extracts showed a broad spectrum of antimicrobial activity, as they have inhibited all tested bacteria and yeasts. This activity seems to be related to the phytochemicals (flavonoid, terpenoids and saponins) detected into the extracts of C. spinosa. ChL and CL extracts were the most actives, with MIC less than 1 mg/mL against S. aureus, Bacillus subtilis, and Micrococcus luteus. It is important to note that these concentrations are much lower than their 50% hemolysis concentration (HC50) values. Strong correlations were found between the average MIC against S. aureus and their phenolic (r = -0.89) and flavonoid content (r = -0.87), reinforcing the possible role of these metabolite classes on the antimicrobial activity of C. spinosa derived extracts. Moreover, CL and CR showed the best inhibitory activity against S. aureus clinical isolates, they also showed synergistic action with oxacillin against all these strains (at least at one combined proportion). These results encourage the identification of active substances which could be used as lead(s) molecules in the development of new antimicrobial drugs. PMID:27446005

  15. In-silico docking based design and synthesis of [1H,3H] imidazo[4,5-b] pyridines as lumazine synthase inhibitors for their effective antimicrobial activity

    PubMed Central

    Harer, Sunil L.; Bhatia, Manish S.

    2014-01-01

    Purpose: The imidazopyridine moiety is important pharmacophore that has proven to be useful for a number of biologically relevant targets, also reported to display antibacterial, antifungal, antiviral properties. Riboflavin biosynthesis involving catalytic step of Lumazine synthase is absent in animals and human, but present in microorganism, one of marked advantage of this study. Still, this path is not exploited as antiinfective target. Here, we proposed different interactions between [1H,3H] imidazo[4,5-b] pyridine test ligands and target protein Lumazine synthase (protein Data Bank 2C92), one-step synthesis of title compounds and further evaluation of them for in vitro antimicrobial activity. Materials and Methods: Active pocket of the target protein involved in the interaction with the test ligands molecules was found using Biopredicta tools in VLifeMDS 4.3 Suite. In-silico docking suggests H-bonding, hydrophobic interaction, charge interaction, aromatic interaction, and Vanderwaal forces responsible for stabilizing enzyme-inhibitor complex. Disc diffusion assay method was used for in vitro antimicrobial screening. Results and Discussion: Investigation of possible interaction between test ligands and target lumazine synthase of Mycobacterium tuberculosis suggested 1i and 2f as best fit candidates showing hydrogen bonding, hydrophobic, aromatic and Vanderwaal's forces. Among all derivatives 1g, 1j, 1k, 1l, 2a, 2c, 2d, 2e, 2h, and 2j exhibited potent activities against bacteria and fungi compared to the standard Ciprofloxacin and Fluconazole, respectively. The superiority of 1H imidazo [4,5-b] pyridine compounds having R’ = Cl >No2 > NH2 at the phenyl/aliphatic moiety resident on the imidazopyridine, whereas leading 3H imidazo[4,5-b] pyridine compounds containing R/Ar = Cl > No2 > NH2> OCH3 substituents on the 2nd position of imidazole. PMID:25400412

  16. Antimicrobial activity in the cuticle of the American lobster, Homarus americanus.

    PubMed

    Mars Brisbin, Margaret; McElroy, Anne E; Pales Espinosa, Emmanuelle; Allam, Bassem

    2015-06-01

    American lobster, Homarus americanus, continues to be an ecologically and socioeconomically important species despite a severe decline in catches from Southern New England and Long Island Sound (USA) and a high prevalence of epizootic shell disease in these populations. A better understanding of lobster immune defenses remains necessary. Cuticle material collected from Long Island Sound lobsters was found to be active against a broad spectrum of bacteria, including Gram-negative and -positive species. The antimicrobial activity was characterized by boiling, muffling, and size fractioning. Boiling did not significantly reduce activity, while muffling did have a significant effect, suggesting that the active component is organic and heat stable. Size fractioning with 3 and 10 kDa filters did not significantly affect activity. Fast protein liquid chromatography fractions were also tested for antimicrobial activity, and fractions exhibiting protein peaks remained active. MALDI mass spectrometry revealed peptide peaks at 1.6, 2.8, 4.6, and 5.6 kDa. The data presented suggest that one or several antimicrobial peptides contribute to antimicrobial activity present in the American lobster cuticle. PMID:25804485

  17. In vitro antimicrobial activity of nanoconjugated vancomycin against drug resistant Staphylococcus aureus.

    PubMed

    Chakraborty, Subhankari Prasad; Sahu, Sumanta Kumar; Pramanik, Panchanan; Roy, Somenath

    2012-10-15

    The mounting problem of antibiotic resistance of Staphylococcus aureus has prompted renewed efforts toward the discovery of novel antimicrobial agents. The present study was aimed to evaluate the in vitro antimicrobial activity of nanoconjugated vancomycin against vancomycin sensitive and resistant S. aureus strains. Folic acid tagged chitosan nanoparticles are used as Trojan horse to deliver vancomycin into bacterial cells. In vitro antimicrobial activity of nanoconjugated vancomycin against VSSA and VRSA strains was determined by minimum inhibitory concentration, minimum bactericidal concentration, tolerance and disc agar diffusion test. Cell viability and biofilm formation was assessed as indicators of pathogenicity. To establish the possible antimicrobial mechanism of nanoconjugated vancomycin, the cell wall thickness was studied by TEM study. The result of the present study reveals that nano-sized vehicles enhance the transport of vancomycin across epithelial surfaces, and exhibits its efficient drug-action which has been understood from studies of MIC, MBC, DAD of chitosan derivative nanoparticle loaded with vancomycin. Tolerance values distinctly showed that vancomycin loaded into nano-conjugate is very effective and has strong bactericidal effect on VRSA. These findings strongly enhanced our understanding of the molecular mechanism of nanoconjugated vancomycin and provide additional rationale for application of antimicrobial therapeutic approaches for treatment of staphylococcal pathogenesis. PMID:22841851

  18. Antimicrobial and antiproliferative activity of Athamanta sicula L. (Apiaceae)

    PubMed Central

    Stefano, Vita Di; Pitonzo, Rosa; Schillaci, Domenico

    2011-01-01

    Background: Athamanta sicula L., a member of Apiaceae, is an annual perennial herb and it is known in Sicilian popular medicine with the name of “spaccapietre” (rock splitters), because fresh roots infusions are indicated as diuretic and used in the treatment of diseases of the urinary tract, and to dissolve kidney stones. Materials and Methods: Acetone extracts of leaves, flowers, and stems of A. sicula L. were investigated in vitro for antibacterial and cytotoxic activities. Antimicrobial activity was carried out against bacterial and fungal strains and antiproliferative activity against a group of human cancer cell lines (K-562, NCI-H460, and MCF-7). Results: All acetone extracts, apiol and myristicin, resulted inactive as antimicrobial agents at the maximum tested concentration of 200 μg/mL, but they induced significant antiproliferative activity on the tested cancer cell lines. Conclusions: Our study show that both apiol and myristicin could be tested as novel treatment in cancer chemotherapy. PMID:21472076

  19. Antimicrobial activity of different tea varieties available in Pakistan.

    PubMed

    Zakir, Muhammad; Sultan, Khush Bakht; Khan, Haroon; Ihsaanullah; Khan, Murad Ali; Fazal, Hina; Rauf, Abdur

    2015-11-01

    In this antimicrobial study, various extracts of Green and Black tea (Camellia sinensis) and Lemon grass (Cymbopogon citrates) were evaluated for antimicrobial activities against six bacterial strains including both human pathogenic bacteria (Escherichia coli, Pseudomonas aeuroginosa, Staphylococcus aureus and Salmonella typhi) and plant pathogenic bacteria (Erwinia carotovora, Agro bacterium tumifaciens) and one fungal strain Candida albicans by disc diffusion susceptibility method. Of human pathogens, P. aeruginosa was most susceptible to all three different tea varieties; though rest of the strains also demonstrated prominent sensitivity. In comparison, black tea extracts were less activities than green tea and lemon grass. However, all the three tea varieties illustrated profound activity against plant pathogenic bacteria. Similarly, when extracts of tea were tested against C. albicans, green tea and lemon grass exhibited significant activity while black tea was mostly inactive. PMID:26639502

  20. Antimicrobial and cytotoxic activities from Jatropha dioica roots.

    PubMed

    Silva-Belmares, Yesenia; Rivas-Morales, Catalina; Viveros-Valdez, Ezequiel; de la Cruz-Galicia, María Guadalupe; Carranza-Rosales, Pilar

    2014-05-01

    The antimicrobial and cytotoxic activities of organic extracts obtained from roots of the medicinal plant Jatropha dioica (Euphorbiaceae) were investigated. In order to evaluate their antimicrobial activity, the organic extracts were tested against clinical isolates of the human pathogens Bacillus cereus, Escherichia coli, Salmonella typhi, Staphylococcus aureus, Enterobacter aerogenes, Enterobacter cloacae, Salmonella typhimurium, Cryptococcus neoformans, Candida albicans, Candida parapsilosis and Sporothrix schenckii. Results revealed that the hexane extract possess the stronger activity and a broader microbicide spectrum compared to the acetone and ethanol extracts. The activity of hexane extract may be attributed in part to the presence of β-sitosterol, the major compound identified by bioautography. The hexane extract, as well as the bioactive fraction were not cytotoxic when assays were profiled against the normal cell lines Chang, OK and LLCPK-1 (IC50>1000 μg mL(-1)). PMID:26031013

  1. Study of the nanomaterials and their antimicrobial activities

    NASA Astrophysics Data System (ADS)

    Ramadi, Muntaha

    In the last decade, the world faced huge problems associated with the spread of antimicrobial resistant infections that are essentially untreatable such as methicillin resistant Staphylococcus aureus (MRSA) infection. These infections have begun to occur in both hospital and community environments. Developing new antimicrobial surface coatings can hold a great promise to minimize and control various problems that associated with the spreading of infections and biofilms formation, these coatings can be used in medicine where medical devices associated with severe infections, in construction industry and the in food packaging industry. It has been established that single-walled CNTs exhibit a strong antimicrobial activity and can pierce bacterial cell walls. Recently, nanomaterial structures that made from pure carbon such as CNTs have been seen as promising candidates for many potential applications in Biotechnology and bioscience due to the combination of their extraordinary properties that arise from surface area, light weight, strength, flexibility, unique electrical conductivity and many more novel physical and chemical properties at nanoscale level. CNTs have been used widely in biomedical field including drug delivery, gene therapy and creating new biomedical devices with novel properties. Researchers have now made a first step to add carbon nanotubes to antimicrobial agents list. There are two types of CNTs have been used in biomedical research. The first one is a single-walled carbon nanotube (SWNT) and the second is a multi-walled carbon nanotube (MWNT). Recent in vitro studies suggest that carbon nanotubes have antimicrobial activity and coating CNTs with nickel nanoparticle could enhance the antimicrobial activity of cabon nanotubes. In order to test this hypothesis, nickel nanoparticles were deposited on carbon nanotubes (CNTs) by electrochemical deposition. The carbon nanotubes used in this study were XD-CNTs, SWNTs and Ni-coated CNTs. The structure and

  2. Antimicrobial activity of extracts of three major plants from the Chihuahuan desert.

    PubMed

    Verástegui, M A; Sánchez, C A; Heredia, N L; García-Alvarado, J S

    1996-07-01

    Dilution methods were employed to determine the effect of ethanolic extracts of Agave lecheguilla Torr. (Agavaceae), Baccharis glutinosa Pers. (Compositae) and Larrea tridentata (DC.) Cov. (Zygophyllaceae) on growth of yeasts, molds and bacteria. The three extracts analyzed showed good antimicrobial activity against more than one organism. The minimal inhibitory concentration of the extracts was also determined. PMID:8771460

  3. Antimicrobial and antiproliferative activity of Peucedanum nebrodense (Guss.) Strohl.

    PubMed

    Schillaci, D; Venturella, F; Venuti, F; Plescia, F

    2003-07-01

    Acetone extract of Peucedanum nebrodense (Guss.) Strohl., a rare endemic species from the Madonie mountains (Sicily), was tested in vitro for its antimicrobial activity against bacterial reference strains and antiproliferative activity against K562 (human chronic myelogenous leukemia), HL-60 (human leukemia) and L1210 (murine leukemia) cell lines. The acetone extract showed antiproliferative IC50 values in the range of 14-0.27 microg/ml. PMID:12787961

  4. Anticancer and enhanced antimicrobial activity of biosynthesizd silver nanoparticles against clinical pathogens

    NASA Astrophysics Data System (ADS)

    Rajeshkumar, Shanmugam; Malarkodi, Chelladurai; Vanaja, Mahendran; Annadurai, Gurusamy

    2016-07-01

    The present investigation shows the biosynthesis of eco-friendly silver nanoparticles using culture supernatant of Enterococcus sp. and study the effect of enhanced antimicrobial activity, anticancer activity against pathogenic bacteria, fungi and cancer cell lines. Silver nanoparticles was synthesized by adding 1 mM silver nitrate into the 100 ml of 24 h freshly prepared culture supernatant of Enterococcus sp. and were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Selected Area Diffraction X-Ray (SAED), Energy Dispersive X Ray (EDX) and Fourier Transform Infra red Spectroscopy (FT-IR). The synthesized silver nanoparticles were impregnated with commercial antibiotics for evaluation of enhanced antimicrobial activity. Further these synthesized silver nanoparticles were assessed for its anticancer activity against cancer cell lines. In this study crystalline structured nanoparticles with spherical in the size ranges from 10 to 80 nm and it shows excellent enhanced antimicrobial activity than the commercial antibiotics. The in vitro assay of silver nanoparticles on anticancer have great potential to inhibit the cell viability. Amide linkages and carboxylate groups of proteins from Enterococcus sp. may bind with silver ions and convert into nanoparticles. The activities of commercial antibiotics were enhanced by coating silver nanoparticles shows significant improved antimicrobial activity. Silver nanoparticles have the great potential to inhibit the cell viability of liver cancer cells lines (HepG2) and lung cancer cell lines (A549).

  5. Anticancer and enhanced antimicrobial activity of biosynthesizd silver nanoparticles against clinical pathogens

    NASA Astrophysics Data System (ADS)

    Rajeshkumar, Shanmugam; Malarkodi, Chelladurai; Vanaja, Mahendran; Annadurai, Gurusamy

    2016-07-01

    The present investigation shows the biosynthesis of eco-friendly silver nanoparticles using culture supernatant of Enterococcus sp. and study the effect of enhanced antimicrobial activity, anticancer activity against pathogenic bacteria, fungi and cancer cell lines. Silver nanoparticles was synthesized by adding 1 mM silver nitrate into the 100 ml of 24 h freshly prepared culture supernatant of Enterococcus sp. and were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Selected Area Diffraction X-Ray (SAED), Energy Dispersive X Ray (EDX) and Fourier Transform Infra red Spectroscopy (FT-IR). The synthesized silver nanoparticles were impregnated with commercial antibiotics for evaluation of enhanced antimicrobial activity. Further these synthesized silver nanoparticles were assessed for its anticancer activity against cancer cell lines. In this study crystalline structured nanoparticles with spherical in the size ranges from 10 to 80 nm and it shows excellent enhanced antimicrobial activity than the commercial antibiotics. The in vitro assay of silver nanoparticles on anticancer have great potential to inhibit the cell viability. Amide linkages and carboxylate groups of proteins from Enterococcus sp. may bind with silver ions and convert into nanoparticles. The activities of commercial antibiotics were enhanced by coating silver nanoparticles shows significant improved antimicrobial activity. Silver nanoparticles have the great potential to inhibit the cell viability of liver cancer cells lines (HepG2) and lung cancer cell lines (A549).

  6. Antimicrobial activity of Amazon Astrocaryum aculeatum extracts and its association to oxidative metabolism.

    PubMed

    Jobim, Micheli Lamberti; Santos, Roberto Christ Vianna; dos Santos Alves, Camilla Filippi; Oliveira, Raul Moreira; Mostardeiro, Clarice Pinheiro; Sagrillo, Michele Rorato; de Souza Filho, Olmiro Cezimbra; Garcia, Luiz Filipe Machado; Manica-Cattani, Maria Fernanda; Ribeiro, Euler Esteves; da Cruz, Ivana Beatrice Mânica

    2014-04-01

    Several compounds present in fruits as polyphenols are able to kill or inhibit the growth of microorganisms. These proprieties are relevant mainly in tropical areas, as Amazonian region where infectious are highly prevalent. Therefore, this study investigated the antimicrobial activity of tucumã Amazonian fruit against 37 microorganisms. The potential role of oxidative metabolism imbalance was also studied as causal mechanism of antimicrobial activity. The results showed antibacterial effect of pulp and peel tucumã hydro-alcoholic extracts on three Gram-positive bacteria (Enterococcus faecalis, Bacillus cereus, Listeria monocytogenes) and antifungal effect against Candida albicans. The antimicrobial contribution of main chemical compounds (quercetin, rutin, β-carotene and gallic, caffeic and chlorogenic acids) found in tucumã extracts was also investigated showing an inhibitory effect depending of the organism mainly by quercetin in bacteria and rutin in C. albicans. Analysis of kinetic of DNA releasing in extracellular medium by fluorescence using DNA Pico Green assay(®) and reactive oxygen species production (ROS) showed potential oxidative imbalance contribution on tucumã inhibitory effect. In B. cereus and C. albicans this effect was clear since after 24h the ROS levels were higher when compared to negative control group. In conclusion, tucumã extracts present antimicrobial activity to four microorganisms that have large problems of drug resistance, and the possible mechanism of action of this Amazon fruit is related to REDOX imbalance. PMID:23870852

  7. In Vitro Antimicrobial and Antiproliferative Activity of Amphipterygium adstringens

    PubMed Central

    Rodriguez-Garcia, A.; Peixoto, I. T. A.; Verde-Star, M. J.; De la Torre-Zavala, S.; Aviles-Arnaut, H.; Ruiz, A. L. T. G.

    2015-01-01

    Amphipterygium adstringens is a plant widely used in Mexican traditional medicine for its known anti-inflammatory and antiulcer properties. In this work, we evaluated the in vitro antimicrobial and antiproliferative activities of the methanolic extract of A. adstringens against oral pathogens such as Streptococcus mutans, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Candida albicans, and Candida dubliniensis, using microdilution (MIC) and agar diffusion methods (MBC), and the antiproliferative activity evaluating total growth inhibition (TGI) by staining the protein content with sulforhodamine B (SRB), using nine human cancer cell lines. Crude extract (CE) of A. adstringens showed some degree of activity against one or more of the strains with a MIC from 0.125 mg/mL to 63 mg/mL and MBC from 1.6 to 6.3 mg/mL and cytotoxic activity, particularly against NCI-ADR/RES, an ovarian cell line expressing multiple resistance drugs phenotype. The CE is a complex mixture of possible multitarget metabolites that could be responsible for both antimicrobial and antiproliferative activities, and further investigation is required to elucidate the identity of active compounds. Nevertheless the CE itself is useful in the development of new antimicrobial treatment based on natural products to prevent oral diseases and as alternative natural source for cancer treatment and prevention. PMID:26451151

  8. An integrated study on antimicrobial activity and ecotoxicity of quantum dots and quantum dots coated with the antimicrobial peptide indolicidin.

    PubMed

    Galdiero, Emilia; Siciliano, Antonietta; Maselli, Valeria; Gesuele, Renato; Guida, Marco; Fulgione, Domenico; Galdiero, Stefania; Lombardi, Lucia; Falanga, Annarita

    2016-01-01

    This study attempts to evaluate the antimicrobial activity and the ecotoxicity of quantum dots (QDs) alone and coated with indolicidin. To meet this objective, we tested the level of antimicrobial activity on Gram-positive and Gram-negative bacteria, and we designed an ecotoxicological battery of test systems and indicators able to detect different effects using a variety of end points. The antibacterial activity was analyzed against Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 1025), Escherichia coli (ATCC 11229), and Klebsiella pneumoniae (ATCC 10031), and the results showed an improved germicidal action of QDs-Ind. Toxicity studies on Daphnia magna indicated a decrease in toxicity for QDs-Ind compared to QDs alone, lack of bioluminescence inhibition on Vibrio fisheri, and no mutations in Salmonella typhimurium TA 100. The comet assay and oxidative stress experiments performed on D. magna showed a genotoxic and an oxidative damage with a dose-response trend. Indolicidin retained its activity when bound to QDs. We observed an enhanced activity for QDs-Ind. The presence of indolicidin on the surface of QDs was able to decrease its QDs toxicity. PMID:27616887

  9. An integrated study on antimicrobial activity and ecotoxicity of quantum dots and quantum dots coated with the antimicrobial peptide indolicidin

    PubMed Central

    Galdiero, Emilia; Siciliano, Antonietta; Maselli, Valeria; Gesuele, Renato; Guida, Marco; Fulgione, Domenico; Galdiero, Stefania; Lombardi, Lucia; Falanga, Annarita

    2016-01-01

    This study attempts to evaluate the antimicrobial activity and the ecotoxicity of quantum dots (QDs) alone and coated with indolicidin. To meet this objective, we tested the level of antimicrobial activity on Gram-positive and Gram-negative bacteria, and we designed an ecotoxicological battery of test systems and indicators able to detect different effects using a variety of end points. The antibacterial activity was analyzed against Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 1025), Escherichia coli (ATCC 11229), and Klebsiella pneumoniae (ATCC 10031), and the results showed an improved germicidal action of QDs-Ind. Toxicity studies on Daphnia magna indicated a decrease in toxicity for QDs-Ind compared to QDs alone, lack of bioluminescence inhibition on Vibrio fisheri, and no mutations in Salmonella typhimurium TA 100. The comet assay and oxidative stress experiments performed on D. magna showed a genotoxic and an oxidative damage with a dose–response trend. Indolicidin retained its activity when bound to QDs. We observed an enhanced activity for QDs-Ind. The presence of indolicidin on the surface of QDs was able to decrease its QDs toxicity. PMID:27616887

  10. Biological activity assessment of a novel contraceptive antimicrobial agent.

    PubMed

    Garg, A; Anderson, R A; Zaneveld, L J D; Garg, S

    2005-01-01

    Microbicides are a new category of compounds being developed as a prophylactic approach for the prevention of transmission of sexually transmitted diseases (STDs), including the human immunodeficiency virus (HIV). These are primarily being developed as women-controlled methods, with the target of designing new compounds or formulations that can be used without the knowledge of a male partner. Microbicide screening can be initially based on their hyaluronidase-inhibiting (HI) activity, as this enzyme plays a major role in the sperm and microbe penetration into the substrate. Derivatives of hesperidin, a citrus flavonoid glycoside, have been reported in the literature for their HI effects. Hesperidin was thereby sulphonated under strictly controlled conditions and the active fraction isolated and characterized, based on its HI activity. This derivative was screened for antimicrobial and enzyme-inhibitory activities, specifically for the reproductive tract. Sulphonated hesperidin (SH) was found to completely inhibit the sperm enzymes hyaluronidase, giving an indication toward its contraceptive effects. It was also been found to inhibit various sexually transmitted pathogens, including Chlamydia trachomatis, Neisseria gonorrhoea, HIV, and Herpes Simplex virus type 2 (HSV-2). Its safety assessment was based on its noninterference in sperm motility and its penetration through the cervical mucus, and no effect on the growth of lactobacilli, the normal vaginal flora. It was also found to be nontoxic to the HIV substrate cells (MT2 cells). The study concludes that sulphonated hesperidin can be developed as a potential microbicide for a dual prophylaxis of contraception and transmission of STDs and AIDS. PMID:15867010

  11. Chemical constituents of Solanum coagulans and their antimicrobial activities.

    PubMed

    Qin, Xu-Jie; Lunga, Paul-Keilah; Zhao, Yun-Li; Liu, Ya-Ping; Luo, Xiao-Dong

    2016-04-01

    The present study aimed at determining the chemical constituents of Solanum coagulans and their antimicrobial activities. The compounds were isolated by various chromatographic techniques and their structures were elucidated on the basis of extensive spectroscopic analysis, chemical methods, and comparison with reported spectroscopic data. One new phenolic glycoside, methyl salicylate 2-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside (1), together with 12 known compounds (2-13), were isolated from the aerial parts of Solanum coagulans. Compound 1 was a new phenolic glycoside, and 2-6 were isolated from Solanum genus for the first time. The antimicrobial activities of the isolated compounds were also evaluated. Compound 7 showed remarkable antifungal activity against T. mentagrophytes, M. gypseum and E. floccosum with MIC values being 3.13, 1.56 and 3.13 μg·mL(-1), respectively. PMID:27114320

  12. In-vitro Antimicrobial Activities of Some Iranian Conifers.

    PubMed

    Afsharzadeh, Maryam; Naderinasab, Mahboobe; Tayarani Najaran, Zahra; Barzin, Mohammad; Emami, Seyed Ahmad

    2013-01-01

    Male and female leaves and fruits of eleven different taxons of Iranian conifers (Cupressus sempervirens var. horizontalis, C. sempervirens var. sempervirens, C. sempervirens cv. Cereifeormis, Juniperus communis subsp. hemisphaerica, J. excelsa subsp. excelsa, J. excelsa subsp. polycarpos, J. foetidissima, J. oblonga, J. sabina, Platycladus orientalis and Taxus baccata) were collected from different localities of Iran, dried and extracted with methanol. The extracts were tested for their antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans. The extracts were screened qualitatively using four different methods, the disc diffusion, hole plate, cylinder agar diffusion and agar dilution methods, whereas the minimum inhibitory concentrations (MIC) of each extract were determined by the agar dilution method. The best result was obtained by means of hole plate method in qualitative determination of antimicrobial activities of extracts and the greatest activity was found against S. aureus in all tested methods. PMID:24250573

  13. In-vitro Antimicrobial Activities of Some Iranian Conifers

    PubMed Central

    Afsharzadeh, Maryam; Naderinasab, Mahboobe; Tayarani Najaran, Zahra; Barzin, Mohammad; Emami, Seyed Ahmad

    2013-01-01

    Male and female leaves and fruits of eleven different taxons of Iranian conifers (Cupressus sempervirens var. horizontalis, C. sempervirens var. sempervirens, C. sempervirens cv. Cereifeormis, Juniperus communis subsp. hemisphaerica, J. excelsa subsp. excelsa, J. excelsa subsp. polycarpos, J. foetidissima, J. oblonga, J. sabina, Platycladus orientalis and Taxus baccata) were collected from different localities of Iran, dried and extracted with methanol. The extracts were tested for their antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans. The extracts were screened qualitatively using four different methods, the disc diffusion, hole plate, cylinder agar diffusion and agar dilution methods, whereas the minimum inhibitory concentrations (MIC) of each extract were determined by the agar dilution method. The best result was obtained by means of hole plate method in qualitative determination of antimicrobial activities of extracts and the greatest activity was found against S. aureus in all tested methods. PMID:24250573

  14. Evaluating the antimicrobial activity of Nisin, Lysozyme and Ethylenediaminetetraacetate incorporated in starch based active food packaging film.

    PubMed

    Bhatia, Sugandha; Bharti, Anoop

    2015-06-01

    The pleothera of micro organisms obtained from contaminated food cultured in a starch broth was effectively tested against antibacterial agents, i.e. nisin, lysozyme and chelating agent EDTA. A variety of combination treatments of these antimicrobial agents and their incorporation in Starch based active packaging film according to their permissibility standards was done. 4 variables of Nisin concentration (ranging from 0 to 750 IU/ml), 3 variables of lysozyme concentration (ranging from 0 to 500 IU/ml) and 3 variables of EDTA concentration from (0 to 20 μM) were chosen. Bacterial inhibition by combination of different levels of different factors without antimicrobial films was evaluated using a liquid incubation method. The samples were assayed for turbidity at interval of 2, 4 and 24 h to check effectiveness of combined effects of antimicrobial agents which proved a transitory bactericidal effect for short incubation times. Zone of Inhibition was observed in the antimicrobial films prepared by agar diffusion method. Statistical analysis of experimental data for their antimicrobial spectrum was carried out by multi regression analysis and ANOVA using Design-Expert software to plot the final equation in terms of coded factors as antimicrobial agents. The experimental data indicated that the model was highly significant. Results were also evaluated graphically using response surface showing interactions between two factors, keeping other factor fixed at values at the center of domain. Synergy was also determined among antibacterial agents using the fractional inhibitory concentration (FIC) index which was observed to be 0.56 supporting the hypothesis that nisin and EDTA function as partial synergistically. The presented work aimed to screen in quick fashion the combinatorial effect of three antimicrobial agents and evaluating their efficacy in anti microbial film development. PMID:26028732

  15. Antioxidant, antimicrobial and anticancer activity of the lichens Cladonia furcata, Lecanora atra and Lecanora muralis

    PubMed Central

    2011-01-01

    Background The aim of this study is to investigate in vitro antioxidant, antimicrobial and anticancer activity of the acetone extracts of the lichens Cladonia furcata, Lecanora atra and Lecanora muralis. Methods Antioxidant activity was evaluated by five separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds and determination of total flavonoid content. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method against six species of bacteria and ten species of fungi. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. Results Of the lichens tested, Lecanora atra had largest free radical scavenging activity (94.7% inhibition), which was greater than the standard antioxidants. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. Extract of Cladonia furcata was the most active antimicrobial agent with minimum inhibitory concentration values ranging from 0.78 to 25 mg/mL. All extracts were found to be strong anticancer activity toward both cell lines with IC50 values ranging from 8.51 to 40.22 μg/mL. Conclusions The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial and anticancer effects. That suggest that lichens may be used as as possible natural antioxidant, antimicrobial and anticancer agents to control various human, animal and plant diseases. PMID:22013953

  16. Antimicrobial activity of UV-induced phenylamides from rice leaves.

    PubMed

    Park, Hye Lin; Yoo, Youngchul; Hahn, Tae-Ryong; Bhoo, Seong Hee; Lee, Sang-Won; Cho, Man-Ho

    2014-01-01

    Rice produces a wide array of phytoalexins in response to pathogen attacks and UV-irradiation. Except for the flavonoid sakuranetin, most phytoalexins identified in rice are diterpenoid compounds. Analysis of phenolic-enriched fractions from UV-treated rice leaves showed that several phenolic compounds in addition to sakuranetin accumulated remarkably in rice leaves. We isolated two compounds from UV-treated rice leaves using silica gel column chromatography and preparative HPLC. The isolated phenolic compounds were identified as phenylamide compounds: N-trans-cinnamoyltryptamine and N-p-coumaroylserotonin. Expression analysis of biosynthetic genes demonstrated that genes for arylamine biosynthesis were upregulated by UV irradiation. This result suggested that phenylamide biosynthetic pathways are activated in rice leaves by UV treatment. To unravel the role of UV-induced phenylamides as phytoalexins, we examined their antimicrobial activity against rice fungal and bacterial pathogens. N-trans-Cinnamoyltryptamine inhibited the growth of rice brown spot fungus (Bipolaris oryzae). In addition to the known antifungal activity to the blast fungus, sakuranetin had antimicrobial activity toward B. oryzae and Rhizoctonia solani (rice sheath blight fungus). UV-induced phenylamides and sakuranetin also had antimicrobial activity against rice bacterial pathogens for grain rot (Burkholderia glumae), blight (Xanthomonas oryzae pv. oryzae) and leaf streak (X. oryzae pv. oryzicola) diseases. These findings suggested that the UV-induced phenylamides in rice are phytoalexins against a diverse array of pathogens. PMID:25383752

  17. Design and characterization of an acid-activated antimicrobial peptide.

    PubMed

    Li, Lina; He, Jian; Eckert, Randal; Yarbrough, Daniel; Lux, Renate; Anderson, Maxwell; Shi, Wenyuan

    2010-01-01

    Dental caries is a microbial biofilm infection in which the metabolic activities of plaque bacteria result in a dramatic pH decrease and shift the demineralization/remineralization equilibrium on the tooth surface towards demineralization. In addition to causing a net loss in tooth minerals, creation of an acidic environment favors growth of acid-enduring and acid-generating species, which causes further reduction in the plaque pH. In this study, we developed a prototype antimicrobial peptide capable of achieving high activity exclusively at low environmental pH to target bacterial species like Streptococcus mutans that produce acid and thrive under the low pH conditions detrimental for tooth integrity. The features of clavanin A, a naturally occurring peptide rich in histidine and phenylalanine residues with pH-dependent antimicrobial activity, served as a design basis for these prototype 'acid-activated peptides' (AAPs). Employing the major cariogenic species S. mutans as a model system, the two AAPs characterized in this study exhibited a striking pH-dependent antimicrobial activity, which correlated well with the calculated charge distribution. This type of peptide represents a potential new way to combat dental caries. PMID:19878192

  18. Synthesis and Antimicrobial Activity of 9-O-Substituted Palmatine Derivatives

    PubMed Central

    Li, Z. C.; Kong, X. B.; Mai, W. P.; Sun, G. C.; Zhao, S. Z.

    2015-01-01

    A series of new palmatine derivatives with alkyl or alkyl with N-heterocyclic structures were designed and synthesized at C-9-O according to the principle of association. These compounds were characterised by 1H NMR, 13C NMR, ESI-MS and elemental analysis, and tested for their antimicrobial activity in vitro to evaluate structure-activity relationships. The results indicated that 9-O-substituted palmatine derivatives exhibit varying degrees of antimicrobial activity. Antibacterial activities of compounds (3a-f) against Gram +ve bacteria increased 2- to 64-fold than that of palmatine. The compounds (3a-f) possessed relatively weaker inhibitory effects against Gram −ve bacteria and fungi than that against Gram +ve bacteria. Antimicrobial activities of compounds (5a-e) are lower than that of compounds (3a-f). Compound 3d showed the highest antimicrobial activity of all the compounds. The LD50 values of compounds (3a-f) decreased as the alkyl side chain was elongated. Compound 3f showed least toxicity. PMID:26009653

  19. Synthesis, antimycobacterial, antiviral, antimicrobial activity and QSAR studies of N(2)-acyl isonicotinic acid hydrazide derivatives.

    PubMed

    Judge, Vikramjeet; Narasimhan, Balasubramanian; Ahuja, Munish; Sriram, Dharmarajan; Yogeeswari, Perumal; De Clercq, Erik; Pannecouque, Christophe; Balzarini, Jan

    2013-02-01

    A series of N(2)-acyl isonicotinic acid hydrazides (1-17) was synthesized and tested for its in vitro antimycobacterial activity against Mycobacterium tuberculosis and the results indicated that the compound, isonicotinic acid N'- tetradecanoyl-hydrazide (12) was more active than the reference compound isoniazid. The results of antimicrobial activity of the synthesized compounds against S. aureus, B. subtilis, E. coli, C. albicans and A. niger indicated that compounds with dichloro, hydroxyl, tri-iodo and N(2)-tetradecanoyl substituent were the most active ones. The antiviral activity studies depicted that none of the tested compounds were active against DNA or RNA viruses. The multi-target QSAR model was found to be effective in describing the antimicrobial activity of N(2)-acyl isonicotinic acid hydrazides. PMID:22762163

  20. Antimicrobial Activities of Isothiocyanates Against Campylobacter jejuni Isolates

    PubMed Central

    Dufour, Virginie; Alazzam, Bachar; Ermel, Gwennola; Thepaut, Marion; Rossero, Albert; Tresse, Odile; Baysse, Christine

    2012-01-01

    Food-borne human infection with Campylobacter jejuni is a medical concern in both industrialized and developing countries. Efficient eradication of C. jejuni reservoirs within live animals and processed foods is limited by the development of antimicrobial resistances and by practical problems related to the use of conventional antibiotics in food processes. We have investigated the bacteriostatic and bactericidal activities of two phytochemicals, allyl-isothiocyanate (AITC), and benzyl isothiocyanate (BITC), against 24 C. jejuni isolates from chicken feces, human infections, and contaminated foods, as well as two reference strains NCTC11168 and 81-176. AITC and BITC displayed a potent antibacterial activity against C. jejuni. BITC showed a higher overall antibacterial effect (MIC of 1.25–5 μg mL−1) compared to AITC (MIC of 50–200 μg mL−1). Both compounds are bactericidal rather than bacteriostatic. The sensitivity levels of C. jejuni isolates against isothiocyanates were neither correlated with the presence of a GGT (γ-Glutamyl Transpeptidase) encoding gene in the genome, with antibiotic resistance nor with the origin of the biological sample. However the ggt mutant of C. jejuni 81-176 displayed a decreased survival rate compared to wild-type when exposed to ITC. This work determined the MIC of two ITC against a panel of C. jejuni isolates, showed that both compounds are bactericidal rather than bacteriostatic, and highlighted the role of GGT enzyme in the survival rate of C. jejuni exposed to ITC. PMID:22919644

  1. Antimicrobial Activity of Serbian Propolis Evaluated by Means of MIC, HPTLC, Bioautography and Chemometrics

    PubMed Central

    Trifković, Jelena; Berić, Tanja; Vovk, Irena; Milojković-Opsenica, Dušanka; Stanković, Slaviša

    2016-01-01

    New information has come to light about the biological activity of propolis and the quality of natural products which requires a rapid and reliable assessment method such as High Performance Thin-Layer Chromatography (HPTLC) fingerprinting. This study investigates chromatographic and chemometric approaches for determining the antimicrobial activity of propolis of Serbian origin against various bacterial species. A linear multivariate calibration technique, using Partial Least Squares, was used to extract the relevant information from the chromatographic fingerprints, i.e. to indicate peaks which represent phenolic compounds that are potentially responsible for the antimicrobial capacity of the samples. In addition, direct bioautography was performed to localize the antibacterial activity on chromatograms. The biological activity of the propolis samples against various bacterial species was determined by a minimum inhibitory concentration assay, confirming their affiliation with the European poplar type of propolis and revealing the existence of two types (blue and orange) according to botanical origin. The strongest antibacterial activity was exhibited by sample 26 against Staphylococcus aureus, with a MIC value of 0.5 mg/mL, and Listeria monocytogenes, with a MIC as low as 0.1 mg/mL, which was also the lowest effective concentration observed in our study. Generally, the orange type of propolis shows higher antimicrobial activity compared to the blue type. PLS modelling was performed on the HPTLC data set and the resulting models might qualitatively indicate compounds that play an important role in the activity exhibited by the propolis samples. The most relevant peaks influencing the antimicrobial activity of propolis against all bacterial strains were phenolic compounds at RF values of 0.37, 0.40, 0.45, 0.51, 0.60 and 0.70. The knowledge gained through this study could be important for attributing the antimicrobial activity of propolis to specific chemical

  2. Antimicrobial Activity of Serbian Propolis Evaluated by Means of MIC, HPTLC, Bioautography and Chemometrics.

    PubMed

    Ristivojević, Petar; Dimkić, Ivica; Trifković, Jelena; Berić, Tanja; Vovk, Irena; Milojković-Opsenica, Dušanka; Stanković, Slaviša

    2016-01-01

    New information has come to light about the biological activity of propolis and the quality of natural products which requires a rapid and reliable assessment method such as High Performance Thin-Layer Chromatography (HPTLC) fingerprinting. This study investigates chromatographic and chemometric approaches for determining the antimicrobial activity of propolis of Serbian origin against various bacterial species. A linear multivariate calibration technique, using Partial Least Squares, was used to extract the relevant information from the chromatographic fingerprints, i.e. to indicate peaks which represent phenolic compounds that are potentially responsible for the antimicrobial capacity of the samples. In addition, direct bioautography was performed to localize the antibacterial activity on chromatograms. The biological activity of the propolis samples against various bacterial species was determined by a minimum inhibitory concentration assay, confirming their affiliation with the European poplar type of propolis and revealing the existence of two types (blue and orange) according to botanical origin. The strongest antibacterial activity was exhibited by sample 26 against Staphylococcus aureus, with a MIC value of 0.5 mg/mL, and Listeria monocytogenes, with a MIC as low as 0.1 mg/mL, which was also the lowest effective concentration observed in our study. Generally, the orange type of propolis shows higher antimicrobial activity compared to the blue type. PLS modelling was performed on the HPTLC data set and the resulting models might qualitatively indicate compounds that play an important role in the activity exhibited by the propolis samples. The most relevant peaks influencing the antimicrobial activity of propolis against all bacterial strains were phenolic compounds at RF values of 0.37, 0.40, 0.45, 0.51, 0.60 and 0.70. The knowledge gained through this study could be important for attributing the antimicrobial activity of propolis to specific chemical

  3. Antimicrobial and antibiofilm activity of cathelicidins and short, synthetic peptides against Francisella.

    PubMed

    Amer, Lilian S; Bishop, Barney M; van Hoek, Monique L

    2010-05-28

    Francisella infects the lungs causing pneumonic tularemia. Focusing on the lung's host defense, we have examined antimicrobial peptides as part of the innate immune response to Francisella infection. Interest in antimicrobial peptides, such as the cathelicidins, has grown due their potential therapeutic applications and the increasing problem of bacterial resistance to commonly used antibiotics. Only one human cathelicidin, LL-37, has been characterized. Helical cathelicidins have also been discovered in snakes including the Chinese King Cobra, Naja atra (NA-CATH). Four synthetic 11-residue peptides (ATRA-1, -2, -1A and -1P) containing variations of a repeated motif within NA-CATH were designed. We hypothesized that these smaller synthetic peptides could have excellent antimicrobial effectiveness with shorter length (and less cost), making them strong potential candidates for development into broad-spectrum antimicrobial compounds. We tested the susceptibility of F. novicida to four ATRA peptides, LL-37, and NA-CATH. Two of the ATRA peptides had high antimicrobial activity (microM), while the two proline-containing ATRA peptides had low activity. The ATRA peptides did not show significant hemolytic activity even at high peptide concentration, indicating low cytotoxicity against host cells. NA-CATH killed Francisella bacteria more quickly than LL-37. However, LL-37 was the most effective peptide against F. novicida (EC50=50 nM). LL-37 mRNA was induced in A549 cells by Francisella infection. We recently demonstrated that F. novicida forms in vitro biofilms. LL-37 inhibited F. novicida biofilm formation at sub-antimicrobial concentrations. Understanding the properties of these peptides, and their endogenous expression in the lung could lead to potential future therapeutic interventions for this lung infection. PMID:20399752

  4. Cationic Fullerenes Are Effective and Selective Antimicrobial Photosensitizers

    PubMed Central

    Tegos, George P.; Demidova, Tatiana N.; Arcila-Lopez, Dennisse; Lee, Haeryeon; Wharton, Tim; Gali, Hariprasad; Hamblin, Michael R.

    2011-01-01

    Summary Fullerenes are soccer ball-shaped molecules composed of carbon atoms, and, when derivatized with functional groups, they become soluble and can act as photosensitizers. Antimicrobial photodynamic therapy combines a nontoxic photosensitizer with harmless visible light to generate reactive oxygen species that kill microbial cells. We have compared the antimicrobial activity of six functionalized C60 compounds with one, two, or three hydrophilic or cationic groups in combination with white light against gram-positive bacteria, gram-negative bacteria, and fungi. After a 10 min incubation, the bis- and tris-cationic fullerenes were highly active in killing all tested microbes (4–6 logs) under conditions in which mammalian cells were comparatively unharmed. These compounds performed significantly better than a widely used antimicrobial photosensitizer, toluidine blue O. The high selectivity and efficacy exhibited by these photosensitizers encourage further testing for antimicrobial applications. PMID:16242655

  5. Bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity

    PubMed Central

    Lievin, V; Peiffer, I; Hudault, S; Rochat, F; Brassart, D; Neeser, J; Servin, A

    2000-01-01

    BACKGROUND AND AIMS—The gastrointestinal microflora exerts a barrier effect against enteropathogens. The aim of this study was to examine if bifidobacteria, a major species of the human colonic microflora, participates in the barrier effect by developing antimicrobial activity against enterovirulent bacteria.
METHODS—Antibacterial activity was examined in vitro against a wide range of Gram negative and Gram positive pathogens. Inhibition of Salmonella typhimurium SL1334 cell association and cell invasion was investigated in vitro using Caco-2 cells. Colonisation of the gastrointestinal tract in vivo by bifidobacteria was examined in axenic C3/He/Oujco mice. Antimicrobial activity was examined in vivo in axenic C3/He/Oujco mice infected by the lethal S typhimurium C5 strain.
RESULTS—Fourteen human bifidobacterium strains isolated from infant stools were examined for antimicrobial activity. Two strains (CA1 and F9) expressed antagonistic activity against pathogens in vitro, inhibited cell entry, and killed intracellular S typhimurium SL1344 in Caco-2 cells. An antibacterial component(s) produced by CA1 and F9 was found to be a lipophilic molecule(s) with a molecular weight of less than 3500. In the axenic C3/He/Oujco mice, CA1 and F9 strains colonised the intestinal tract and protected mice against S typhimurium C5 lethal infection.
CONCLUSION—Several bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity, suggesting that they could participate in the "barrier effect" produced by the indigenous microflora.


Keywords: bifidobacteria; infant microflora; gastrointestinal infection; antimicrobial; microbial infection; intestinal cells PMID:11034580

  6. Antimicrobial Activity of Croton macrostachyus Stem Bark Extracts against Several Human Pathogenic Bacteria

    PubMed Central

    Obey, Jackie K.; von Wright, Atte; Orjala, Jimmy; Kauhanen, Jussi; Tikkanen-Kaukanen, Carina

    2016-01-01

    In Kenya, leaves and roots from Croton macrostachyus are used as a traditional medicine for infectious diseases such as typhoid and measles, but reports on possible antimicrobial activity of stem bark do not exist. In this study, the antibacterial and antifungal effects of methanol, ethyl acetate and butanol extracts, and purified lupeol of C. macrostachyus stem bark were determined against important human gram-negative pathogens Escherichia coli, Salmonella typhi, Klebsiella pneumoniae, and Enterobacter aerogenes, gram-positive Listeria monocytogenes, and a fungus Candida albicans. The most promising broad scale antimicrobial activity against all the studied pathogens was shown by the ethyl acetate extract. The ethyl acetate extract induced the zone of inhibition between 10.1 ± 0.6 mm and 16.0 ± 1.2 mm against S. typhi, E. coli, K. pneumoniae, E. aerogenes, and L. monocytogenes with weaker antimicrobial activity against C. albicans (zone of inhibition: 5.6 ± 1.0 mm). The antibiotic controls (amoxicillin, ciprofloxacin, ampicillin, benzylpenicillin, clotrimazole, and cefotaxime) showed antimicrobial activity with zones of inhibition within 13.4 ± 0.7–22.1 ± 0.9 mm. The ethyl acetate extract had MIC in the range of 125–250 mg/mL against all the studied bacteria and against C. albicans MIC was 500 mg/mL. The present results give scientific evidence and support the traditional use of C. macrostachyus stem bark as a source for antimicrobials. We show that C. macrostachyus stem bark lupeol is a promising antimicrobial agent against several important human pathogens. PMID:27293897

  7. Chemical composition, cytotoxicity, antimicrobial and antifungal activity of several essential oils.

    PubMed

    Cannas, Sara; Usai, Donatella; Tardugno, Roberta; Benvenuti, Stefania; Pellati, Federica; Zanetti, Stefania; Molicotti, Paola

    2016-01-01

    Essential oils (EOs) are known and used for their biological, antibacterial, antifungal and antioxidant properties. Numerous studies have shown that EOs exhibit a large spectrum of biological activities in vitro. The incidence of drug-resistant pathogens and the toxicity of antibiotics have drawn attention to the antimicrobial activity of natural products, encouraging the development of alternative treatments. The aim of this study was to analyse the phytochemical and the cytotoxic characteristic of 36 EOs; we then evaluated the antimicrobial activity of the less-toxic EOs on Gram-positive, Gram-negative and fungi strains. The results showed low cytotoxicity in seven EOs and good activity against Gram-negative and Candida spp. strains. Based on our results, EOs could be proposed as a novel group of therapeutic agents. Further experiments are necessary to confirm their pharmacological effectiveness, and to determine potential toxic effects and the mechanism of their activity in in vivo models. PMID:26214364

  8. Antimicrobial activity of Guinea-Bissau traditional remedies.

    PubMed

    Silva, O; Duarte, A; Cabrita, J; Pimentel, M; Diniz, A; Gomes, E

    1996-01-01

    The ethanolic extracts of twelve plants selected through ethnomedical survey in Guinea-Bissau were investigated for their in vitro antimicrobial properties over ten bacteria and Candida albicans, using agar diffusion and dilution methods. All the tested extracts showed some activity against at least one of the bacteria. Most of the extracts (79%) showed activity against Staphylococcus aureus and only one (Cryptolepis sanguinolenta) against Escherichia coli. Cryptolepis sanguinolenta and Terminalia macroptera root extracts showed some activity against Candida albicans as well as showing an interesting profile of activity against most of the enteropathogen microorganisms. Inhibition zones against Staphylococcus aureus were localised on extract chromatograms by bioautographic techniques. PMID:8778508

  9. Antimicrobial activity and chemical investigation of Brazilian Drosera.

    PubMed

    Ferreira, Dalva Trevisan; Andrei, César Cornélio; Saridakis, Halha Ostrensky; Faria, Terezinha de Jesus; Vinhato, Elisângela; Carvalho, Kátia Eliane; Daniel, Juliana Feijó Souza; Machado, Sílvio Luiz; Saridakis, Dennis Panayotis; Braz-Filho, Raimundo

    2004-11-01

    The antimicrobial activity of three different extracts (hexanic, ethyl acetate, methanol) obtained from Brazilian Drosera species (D. communis, D. montana var. montana, D. brevifolia, D. villosa var. graomogolensis, D. villosa var. villosa, Drosera sp. 1, and Drosera sp. 2 ) were tested against Staphylococcus aureus (ATCC 25923), Enterococcus faecium (ATCC23212), Pseudomonas aeruginosa (ATCC27853), Escherichia coli (ATCC11229), Salmonella choleraesuis (ATCC10708), Klebsiella pneumoniae (ATCC13883), and Candida albicans (a human isolate). Better antimicrobial activity was observed with D. communis and D. montana var. montana ethyl acetate extracts. Phytochemical analyses from D. communis, D. montana var. montana and D. brevifolia yielded 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin); long chain aliphatic hydrocarbons were isolated from D. communis and from D. villosa var. villosa, a mixture of long chain aliphatic alcohols and carboxylic acids, was isolated from D. communis and 3b-O-acetylaleuritolic acid from D. villosa var. villosa. PMID:15654434

  10. Antimicrobial activity and partial characterization of bacteriocin-like inhibitory substances produced by Lactobacillus spp. isolated from artisanal Mexican cheese.

    PubMed

    Heredia-Castro, Priscilia Y; Méndez-Romero, José I; Hernández-Mendoza, Adrián; Acedo-Félix, Evelia; González-Córdova, Aarón F; Vallejo-Cordoba, Belinda

    2015-12-01

    Lactobacillus spp. from Mexican Cocido cheese were shown to produce bacteriocin-like substances (BLS) active against Staphylococcus aureus,Listeria innocua,Escherichia coli, andSalmonella typhimurium by using the disk diffusion method. Crude extracts of Lactobacillus fermentum showed strong inhibitory activity against Staph. aureus, L. innocua, E. coli, and Salmonella cholerae. Complete inactivation of antimicrobial activity was observed after treatment of crude extracts with proteinase K, pronase, papain, trypsin, and lysozyme, confirming their proteinaceous nature. However, antimicrobial activity was partly lost for some of the crude extracts when treated with α-amylase, indicating that carbohydrate moieties were involved. The antimicrobial activity of the crude extracts was stable at 65°C for 30min over a wide pH range (2-8), and addition of potassium chloride, sodium citrate, ethanol, and butanol did not affect antibacterial activity. However, antimicrobial activity was lost after heating at 121°C for 15min, addition of methanol or Tween 80. Fourteen out of 18 Lactobacillus spp. showed antimicrobial activity against different test microorganisms, and 12 presented bacteriocin-like substances. Generation time and growth rate parameters indicated that the antimicrobial activity of crude extracts from 3 different strains was effective against the 4 indicator microorganisms. One of the crude extracts showed inhibition not only against gram-positive but also against gram-negative bacteria. Bacteriocin-like substances produced by this specific Lactobacillus strain showed potential for application as a food biopreservative. PMID:26476937

  11. Inducible factors with antimicrobial activity after immune challenge in the haemolymph of Red Palm Weevil (Insecta).

    PubMed

    Mastore, Maristella; Binda Rossetti, Simona; Giovannardi, Stefano; Scarì, Giorgio; Brivio, Maurizio F

    2015-05-01

    Insects are capable of innate immune responses elicited after microbial infection. In this process, the receptor-mediated recognition of foreign bodies and the subsequent activation of immunocompetent cells lead to the synthesis ex novo of a peptide pool with antimicrobial activity. We investigated the inducible immune response of a coleopteran, Rhynchophorus ferrugineus, challenged with both Gram-negative and Gram-positive bacteria. After immunization, we evaluated the presence of antimicrobial peptides using either biochemical analyses or microbiological techniques. The antimicrobial properties of the newly synthesized protein pool, detectable in haemolymph fractions of low molecular mass, showed strong antibacterial activity against various bacterial strains (Escherichia coli, Pseudomonas sp. OX1, Bacillus subtilis and Micrococcus luteus). In addition to the preliminary study of the mechanism of action of the pool of antimicrobial peptides, we also investigated its effects on bacterial cell walls by means of fluorescence microscopy and scanning electron microscopy. The data suggest that the main effects seem to be directed at destabilizing and damaging the bacterial wall. This study provides data that help us to understand some aspects of the inducible innate immunity in a system model that lacks anticipatory responses. However, the weevil has finely tuned its defensive strategies to counteract effectively microbial infection. PMID:25114180

  12. Isolation and Antimicrobial and Antioxidant Evaluation of Bio-Active Compounds from Eriobotrya Japonica Stems

    PubMed Central

    Rashed, Khaled Nabih; Butnariu, Monica

    2014-01-01

    Purpose: The present study was carried out to evaluate antimicrobial and antioxidant activities from Eriobotrya japonica stems as well investigation of its chemical composition. Methods: Methanol 80% extract of Eriobotrya japonica stems was tested for antimicrobial activity against bacterial and fungal strains and for antioxidant activity using oxygen radical absorbance capacity (ORAC) and the trolox equivalent antioxidant capacity (TEAC) assays and also total content of polyphenols with phytochemical analysis of the extract were determined. Results: The results showed that the extract has a significant antimicrobial activity, it inhibited significantly the growth of Candida albicans suggesting that it can be used in the treatment of fungal infections, and it showed no effect on the other bacterial and fungal strains, the extract has a good antioxidant activity, it has shown high values of oxygen radical absorbance capacity and trolox equivalent antioxidant capacity, while it showed a low value of polyphenol content. Phytochemical analysis of the extract showed the presence of carbohydrates, terpenes, tannins and flavonoids, further phytochemical analysis resulted in the isolation and identification of three triterpenic acids, oleanolic, ursolic and corosolic acids and four flavonoids, naringenin, quercetin, kaempferol 3-O-β-glucoside and quercetin 3-O-α-rhamnoside. Conclusion: These results may help to discover new chemical classes of natural antimicrobial antioxidant substances. PMID:24409413

  13. Chemical composition, antioxidant and antimicrobial activities of essential oil from Wedelia prostrata

    PubMed Central

    Dai, Jiali; Zhu, Liang; Yang, Li; Qiu, Jun

    2013-01-01

    The following study deals with the chemical composition, antioxidant and antimicrobial activity of essential oils of Wedelia prostrata and their main constituents in vitro. A total of 70 components representing 99.26 % of the total oil were identified. The main compounds in the oil were limonene (11.38 %) and α-pinene (10.74 %). Antioxidant assays (1,1-diphenyl-2-picrylhydrazyl, superoxide anion radical, and reducing power test) demonstrate moderate activities for the essential oil and its main components (limonene and α-pinene). The essential oil (1000 μg/disc) exhibited promising antimicrobial activity against 10 strains of test microorganisms as a diameter of zones of inhibition (20.8 to 22.2 mm) and MIC values (125 to 250 µg/ml). The activities of limonene and α-pinene were also determined as main components of the oil. α-Pinene showed higher antimicrobial activity than the essential oil with a diameter of zones of inhibition (20.7 to 22.3 mm) and MIC values (62.5 to 125 µg/ml). The antioxidant and antimicrobial properties of the essential oil may be attributed to the synergistic effects of its diverse major and minor components. PMID:26648809

  14. Antimicrobial activity of Rubus chamaemorus leaves.

    PubMed

    Thiem, B; Goślińska, O

    2004-01-01

    The antibacterial activity of Rubus chamaemorus leaf butanolic fraction of the methanol extract and ellagic acid was evaluated against some Gram-positive and Gram-negative bacteria. Antimycotic activity was assayed against Candida albicans. MICs and MBCs were determined by broth dilution test and by disc diffusion method. PMID:14693229

  15. Phytochemical analysis, antimicrobial, antioxidant activities and total phenols of Ferulago carduchorum in two vegetative stages (flower and fruit).

    PubMed

    Golfakhrabadi, Fereshteh; Shams Ardekani, Mohammad Reza; Saeidnia, Soodabeh; Yousefbeyk, Fatemeh; Jamalifar, Hossein; Ramezani, Nasrin; Akbarzadeh, Tahmineh; Khanavi, Mahnaz

    2016-03-01

    Ferulago carduchorum (Apiaceae family) is an endemic plant of Iran. The crude extract and four fractions of aerial parts of F. carduchorum in two vegetative stages (flower and fruit) were studied for their total phenolic contents, antimicrobial and antioxidant activities using folin-ciocalteu assay, micro dilution method and DPPH assay, respectively. The results indicated that the best antioxidant activity was determined in flower crude extract (IC50=0.44 mg/mL). The flower ethyl acetate fraction (FLE) showed better antimicrobial and antifungal activities than other fractions. So, FLE was selected for phytochemical investigations, resulting in isolation of a flavonoid (hesperetin). Hesperetin showed antimicrobial activity. The results showed that the antimicrobial and antioxidant effects during the flowering are obviously more than the fruit season. PMID:27087085

  16. Antimicrobial activity and hydrophobicity of edible whey protein isolate films formulated with nisin and/or glucose oxidase.

    PubMed

    Murillo-Martínez, María M; Tello-Solís, Salvador R; García-Sánchez, Miguel A; Ponce-Alquicira, Edith

    2013-04-01

    The use of edible antimicrobial films has been reported as a means to improve food shelf life through gradual releasing of antimicrobial compounds on the food surface. This work reports the study on the incorporation of 2 antimicrobial agents, nisin (N), and/or glucose oxidase (GO), into the matrix of Whey protein isolate (WPI) films at pH 5.5 and 8.5. The antimicrobial activity of the edible films was evaluated against Listeria innocua (ATCC 33090), Brochothrix thermosphacta (NCIB10018), Escherichia coli (JMP101), and Enterococcus faecalis (MXVK22). In addition, the antimicrobial activity was related to the hydrophobicity and water solubility of the WPI films. The greatest antibacterial activity was observed in WPI films containing only GO. The combined addition of N and GO resulted in films with lower antimicrobial activity than films with N or GO alone. In most cases, a pH effect was observed as greater antimicrobial response at pH 5.5 as well as higher film matrix hydrophobicity. WPI films supplemented with GO can be used in coating systems suitable for food preservation. PMID:23488765

  17. Screening antimicrobial activity of various extracts of Urtica dioica.

    PubMed

    Modarresi-Chahardehi, Amir; Ibrahim, Darah; Fariza-Sulaiman, Shaida; Mousavi, Leila

    2012-12-01

    Urtica dioica or stinging nettle is traditionally used as an herbal medicine in Western Asia. The current study represents the investigation of antimicrobial activity of U. dioica from nine crude extracts that were prepared using different organic solvents, obtained from two extraction methods: the Soxhlet extractor (Method I), which included the use of four solvents with ethyl acetate and hexane, or the sequential partitions (Method II) with a five solvent system (butanol). The antibacterial and antifungal activities of crude extracts were tested against 28 bacteria, three yeast strains and seven fungal isolates by the disc diffusion and broth dilution methods. Amoxicillin was used as positive control for bacteria strains, vancomycin for Streptococcus sp., miconazole nitrate (30 microg/mL) as positive control for fungi and yeast, and pure methanol (v/v) as negative control. The disc diffusion assay was used to determine the sensitivity of the samples, whilst the broth dilution method was used for the determination of the minimal inhibition concentration (MIC). The ethyl acetate and hexane extract from extraction method I (EA I and HE I) exhibited highest inhibition against some pathogenic bacteria such as Bacillus cereus, MRSA and Vibrio parahaemolyticus. A selection of extracts that showed some activity was further tested for the MIC and minimal bactericidal concentrations (MBC). MIC values of Bacillus subtilis and Methicillin-resistant Staphylococcus aureus (MRSA) using butanol extract of extraction method II (BE II) were 8.33 and 16.33mg/mL, respectively; while the MIC value using ethyl acetate extract of extraction method II (EAE II) for Vibrio parahaemolyticus was 0.13mg/mL. Our study showed that 47.06% of extracts inhibited Gram-negative (8 out of 17), and 63.63% of extracts also inhibited Gram-positive bacteria (7 out of 11); besides, statistically the frequency of antimicrobial activity was 13.45% (35 out of 342) which in this among 21.71% belongs to

  18. Synthesis, characterization, antimicrobial activity and carbonic anhydrase enzyme inhibitor effects of salicilaldehyde-N-methyl p-toluenesulfonylhydrazone and its Palladium(II), Cobalt(II) complexes

    NASA Astrophysics Data System (ADS)

    Alyar, Saliha; Adem, Şevki

    2014-10-01

    We report the synthesis of the ligand, salicilaldehyde-N-methyl p-toluenesulfonylhydrazone (salptsmh) derived from p-toluenesulfonicacid-1-methylhydrazide (ptsmh) and its Pd(II) and Co(II) metal complexes were synthesized for the first time. The structure of the ligand and their complexes were investigated using elemental analysis, magnetic susceptibility, molar conductance and spectral (IR, NMR and LC-MS) measurements. Salptsmh has also been characterized by single crystal X-ray diffraction. 1H and 13C shielding tensors for crystal structure were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The complexes were found to have general composition [ML2]. The results of elemental analysis showed 1:2 (metal/ligand) stoichiometry for all the complex. Magnetic and spectral data indicate a square planar geometry for Pd(II) complex and a distorted tetrahedral geometry for Co(II) complexes. The ligand and its metal chelates have been screened for their antimicrobial activities using the disk diffusion method against the selected Gram positive bacteria: Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Gram negative bacteria: Eschericha coli, Pseudomonas aeruginosa, Klebsiella pneumonia. The inhibition activities of these compounds on carbonic anhydrase II (CA II) and carbonic anhydrase I (CA I) have been investigated by comparing IC50 and Ki values and it has been found that Pd(II) complex have more enzyme inhibition efficiency than salptsmh and Co(II) complex.

  19. Antimicrobial and antitumor activities of chitosan from shiitake stipes, compared to commercial chitosan from crab shells.

    PubMed

    Chien, Rao-Chi; Yen, Ming-Tsung; Mau, Jeng-Leun

    2016-03-15

    Chitosan was prepared by alkaline N-deacetylation of chitin obtained from shiitake stipes and crab shells and its antimicrobial and antitumor activities were studied. Chitosan from shiitake stipes and crab shells exhibited excellent antimicrobial activities against eight species of Gram positive and negative pathogenic bacteria with inhibition zones of 11.4-26.8mm at 0.5mg/ml. Among chitosan samples, shiitake chitosan C120 was the most effective with inhibition zones of 16.4-26.8mm at 0.5mg/ml. In addition, shiitake and crab chitosan showed a moderate anti-proliferative effect on IMR 32 and Hep G2 cells. At 5mg/ml, the viability of IMR 32 cells incubated with chitosan was 68.8-85.0% whereas that of Hep G2 cells with chitosan was 60.4-82.9%. Overall, shiitake chitosan showed slightly better antimicrobial and antitumor activities than crab chitosan. Based on the results obtained, shiitake and crab chitosan were strong antimicrobial agents and moderate antitumor agents. PMID:26794761

  20. Antimicrobial activity of new porphyrins of synthetic and natural origin

    NASA Astrophysics Data System (ADS)

    Gyulkhandanyan, Grigor V.; Ghazaryan, Robert K.; Paronyan, Marina H.; Ulikhanyan, Ghukas I.; Gyulkhandanyan, Aram G.; Sahakyan, Lida A.

    2012-03-01

    Antimicrobial photodynamic inactivation has been successfully used against Gram (+) microorganisms, but most of the photosensitizers (PSs) on Gram (-) bacteria acts weakly. PSs are the natural or synthetic origin dyes, mainly porphyrins. We have synthesized more than 100 new cationic porphyrins and metalloporphyrins with different functional groups (hydroxyethyl, butyl, allyl, methallyl) and metals (cobalt, iron, copper, zinc, silver and other); from the nettle have also been purified pheophytin (a+b) and pheophytin (a) and have synthesized their Ag-and Zn-metalloporphyrins. It was found that in the dark (cytotoxic) mode, the most highly efficiency against microorganisms showed Agmetalloporphyrins of both types of porphyrins (synthetic and natural). Metalloporphyrin of natural origin Ag-pheophytin (a + b) is a strong antibacterial agent and causes 100% death as the Gram (+) microorganisms (St. aureus and MRSA) and the Gram (-) microorganisms (E.coli and Salmonella). It is established that for the destruction of Gram (+) and Gram (-) microorganisms in photodynamic mode cationic water-soluble synthetic metalloporphyrins, especially Zn-TBut4PyP, many times more effective than pheophytins. In vivo conditions on mice established that the best therapeutic activity against various strains of the microorganism St. aureus has the synthetic metalloporphyrin Ag-TBut4PyP. It is significantly more efficient than known drug "Chlorophyllipt" (2.5-3 times) and leads the survival rate of animals up to 50-60%.

  1. Extracellular Streptomyces lividans vesicles: composition, biogenesis and antimicrobial activity

    PubMed Central

    Schrempf, Hildgund; Merling, Philipp

    2015-01-01

    We selected Streptomyces lividans to elucidate firstly the biogenesis and antimicrobial activities of extracellular vesicles that a filamentous and highly differentiated Gram-positive bacterium produces. Vesicle types range in diameter from 110 to 230 nm and 20 to 60 nm, respectively; they assemble to clusters, and contain lipids and phospholipids allowing their in situ imaging by specific fluorescent dyes. The presence of the identified secondary metabolite undecylprodigiosin provokes red fluorescence of a portion of the heterogeneous vesicle populations facilitating in vivo monitoring. Protuberances containing vesicles generate at tips, and alongside of substrate hyphae, and enumerate during late vegetative growth to droplet-like exudates. Owing to in situ imaging in the presence and absence of a green fluorescent vancomycin derivative, we conclude that protuberances comprising vesicles arise at sites with enhanced levels of peptidoglycan subunits [pentapeptide of lipid II (C55)-linked disaccharides], and reduced levels of polymerized and cross-linked peptidoglycan within hyphae. These sites correlate with enhanced levels of anionic phospholipids and lipids. Vesicles provoke pronounced damages of Aspergillus proliferans, Verticillium dahliae and induced clumping and distortion of Escherichia coli. These harmful effects are likely attributable to the action of the identified vesicular compounds including different enzyme types, components of signal transduction cascades and undecylprodigiosin. Based on our pioneering findings, we highlight novel clues with environmental implications and application potential. PMID:25851532

  2. Phytochemical screening, antioxidant, and antimicrobial activities of the crude leaves’ extract from Ipomoea batatas (L.) Lam

    PubMed Central

    Pochapski, Márcia Thaís; Fosquiera, Eliana Cristina; Esmerino, Luís Antônio; dos Santos, Elizabete Brasil; Farago, Paulo Vitor; Santos, Fábio André; Groppo, Francisco Carlos

    2011-01-01

    Background: Ipomoea batatas (L.) Lam., popularly known as sweet potato (SP), has played an important role as an energy and a phytochemical source in human nutrition and animal feeding. Ethnopharmacological data show that SP leaves have been effectively used in herbal medicine to treat inflammatory and/or infectious oral diseases in Brazil. The aim of this research was to evaluate the phytochemical, antioxidant, and antimicrobial activities of the crude leaves’ extract of SP leaves. Materials and Methods: The screening was performed for triterpenes/steroids, alkaloids, anthraquinones, coumarins, flavonoids, saponins, tannins, and phenolic acids. The color intensity or the precipitate formation was used as analytical responses to these tests. The total antioxidant capacity was evaluated by the phosphomolybdenum complex method. Antimicrobial activity was made by agar disk and agar well diffusion tests. Results: The phytochemical screening showed positive results for triterpenes/steroids, alkaloids, anthraquinones, coumarins, flavonoids, saponins, tannins, and phenolic acids. Total contents of 345.65, 328.44, and 662.02 mg were respectively obtained for alkaloids, anthraquinones, and phenolic compounds in 100 g of the dry sample. The total antioxidant capacity was 42.94% as compared to ascorbic acid. For antimicrobial studies, no concentration of the SP freeze dried extract was able to inhibit the growth of Streptococcus mutans, S. mitis, Staphylococcus aureus, and Candida albicans in both agar disk and agar well diffusion tests. Conclusions: SP leaves demonstrated the presence of secondary metabolites with potential biological activities. No antimicrobial activity was observed. PMID:21716926

  3. Antimicrobial activity of essential oil and various extracts of fruits of greater cardamom.

    PubMed

    Agnihotri, Supriya; Wakode, S

    2010-09-01

    Greater cardamom (Amomum subulatum Roxb. Zingiberaceae) commonly known as "Bari ilaichi" is a well known plant used in Ayurvedic and Unani medicine. It has been used for the treatment of various diseases and disorders like gastric ulcer. Therefore antimicrobial activity of petroleum ether, methanol and aqueous extracts from leaves and roots, essential oil and isolated vasicine from A. vasica were tested against various microorganisms. Antimicrobial activity was done by disc diffusion method. The zone of inhibition observed was compared with that of standard drugs, ciprofloxacin and fluconazole. Minimum inhibitory concentration was determined against microorganisms used in the study. The results of this study reveal that methanol extract of fruits of A. subulatum shows remarkable antimicrobial activity against Escherichia coli whereas in case of other microorganisms used it was found inferior to the standard drug used. Methanol extract of rind showed good antimicrobial activity against Staphylococcus aureus. It was found that the essential oil isolated was effective against majority of microorganisms used viz. Bacillus pumilus, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Saccharomyces cerevisiae. PMID:21695005

  4. Molecular mechanisms behind the antimicrobial activity of hop iso-α-acids in Lactobacillus brevis.

    PubMed

    Schurr, Benjamin C; Hahne, Hannes; Kuster, Bernhard; Behr, Jürgen; Vogel, Rudi F

    2015-04-01

    The main bittering component in beer, hop iso-α-acids, have been characterised as weak acids, which act as ionophores impairing microbial cells' function under acidic conditions as present in beer. Besides medium pH, divalent cations play a central role regarding the efficacy of the antimicrobial effect. The iso-α-acids' non-bitter derivatives humulinic acids can be found in isomerised hop extracts and can be generated during hop storage. Therefore, they have been under investigation concerning their influence on beer sensory properties. This study sketches the molecular mechanism behind iso-α-acids' antimicrobial activity in Lactobacillus (L.) brevis regarding their ionophore activity versus the dependence of the inhibitory potential on manganese binding, and suggests humulinic acids as novel tasteless food preservatives. We designed and synthesised chemically modified iso-α-acids to enhance the basic understanding of the molecular mechanism of antimicrobial iso-α-acids. It could be observed that a manganese-binding dependent transmembrane redox reaction (oxidative stress) plays a crucial role in inhibition. Privation of an acidic hydroxyl group neither erased ionophore activity, nor did it entirely abolish antimicrobial activity. Humulinic acids proved to be highly inhibitory, even outperforming iso-α-acids. PMID:25475328

  5. Antimicrobial Activity of Essential Oil and Various Extracts of Fruits of Greater Cardamom

    PubMed Central

    Agnihotri, Supriya; Wakode, S.

    2010-01-01

    Greater cardamom (Amomum subulatum Roxb. Zingiberaceae) commonly known as “Bari ilaichi” is a well known plant used in Ayurvedic and Unani medicine. It has been used for the treatment of various diseases and disorders like gastric ulcer. Therefore antimicrobial activity of petroleum ether, methanol and aqueous extracts from leaves and roots, essential oil and isolated vasicine from A. vasica were tested against various microorganisms. Antimicrobial activity was done by disc diffusion method. The zone of inhibition observed was compared with that of standard drugs, ciprofloxacin and fluconazole. Minimum inhibitory concentration was determined against microorganisms used in the study. The results of this study reveal that methanol extract of fruits of A. subulatum shows remarkable antimicrobial activity against Escherichia coli whereas in case of other microorganisms used it was found inferior to the standard drug used. Methanol extract of rind showed good antimicrobial activity against Staphylococcus aureus. It was found that the essential oil isolated was effective against majority of microorganisms used viz. Bacillus pumilus, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Saccharomyces cerevisiae. PMID:21695005

  6. Organogel-nanoemulsion containing nisin and D-limonene and its antimicrobial activity

    PubMed Central

    Bei, Weiya; Zhou, Yan; Xing, Xuya; Zahi, Mohamed Reda; Li, Yuan; Yuan, Qipeng; Liang, Hao

    2015-01-01

    The aim of this study was to investigate a novel delivery system containing D-limonene and nisin by food organogel-nanoemulsion and study its effect on the antimicrobial activity. Organogel-nanoemulsion containing with D-limonene and nisin or without nisin was prepared by a homogenization method. Factors that may affect the droplet size and stability of organogel-nanoemulsion such as pressure and surfactant to oil ratio (SOR) were studied. The average droplet size decreased with pressure, and the organogel-nanoemulsion could achieve good stability at low SOR. Positive effects and outstanding antimicrobial activities of organogel-nanoemulsion containing with D-limonene and nisin were confirmed by minimal inhibitory concentrations comparison, growth curves of bacteria, scanning electron microscopy and determination of cell constituents’ release. Furthermore, the organogel-nanoemulsion applied as food preservative in milk also shown excellent antimicrobial performance. Overall, the research described in the current article show that organogel-nanoemulsion containing with D-limonene and nisin may be an effective antimicrobial system for the production and preservation of food. PMID:26441935

  7. Antimicrobial properties of membrane-active dodecapeptides derived from MSI-78.

    PubMed

    Monteiro, Claudia; Fernandes, Mariana; Pinheiro, Marina; Maia, Sílvia; Seabra, Catarina L; Ferreira-da-Silva, Frederico; Costa, Fabíola; Reis, Salette; Gomes, Paula; Martins, M Cristina L

    2015-05-01

    Antimicrobial peptides (AMPs) are a class of broad-spectrum antibiotics known by their ability to disrupt bacterial membranes and their low tendency to induce bacterial resistance, arising as excellent candidates to fight bacterial infections. In this study we aimed at designing short 12-mer AMPs, derived from a highly effective and broad spectrum synthetic AMP, MSI-78 (22 residues), by truncating this peptide at the N- and/or C-termini while spanning its entire sequence with 1 amino acid (aa) shifts. These designed peptides were evaluated regarding antimicrobial activity against selected gram-positive Staphylococcus strains and the gram-negative Pseudomonas aeruginosa (P. aeruginosa). The short 12-mer peptide CEM1 (GIGKFLKKAKKF) was identified as an excellent candidate to fight P. aeruginosa infections as it displays antimicrobial activity against this strain and selectivity, with negligible toxicity to mammalian cells even at high concentrations. However, in general most of the short 12-mer peptides tested showed a reduction in antimicrobial activity, an effect that was more pronounced for gram-positive Staphylococcus strains. Interestingly, CEM1 and a highly similar peptide differing by only one aa-shift (CEM2: IGKFLKKAKKFG), showed a remarkably contrasting AMP activity. These two peptides were chosen for a more detailed study regarding their mechanism of action, using several biophysical assays and simple membrane models that mimic the mammalian and bacterial lipid composition. We confirmed the correlation between peptide helicity and antimicrobial activity and propose a mechanism of action based on the disruption of the bacterial membrane permeability barrier. PMID:25680229

  8. Multilayer hydrogel coatings to combine hemocompatibility and antimicrobial activity.

    PubMed

    Fischer, Marion; Vahdatzadeh, Maryam; Konradi, Rupert; Friedrichs, Jens; Maitz, Manfred F; Freudenberg, Uwe; Werner, Carsten

    2015-07-01

    While silver-loaded catheters are widely used to prevent early-onset catheter-related infections [1], long term antimicrobial protection of indwelling catheters remains to be achieved [2] and antiseptic functionalization of coatings often impairs their hemocompatibility characteristics. Therefore, this work aimed to capitalize on the antimicrobial properties of silver nanoparticles, incorporated in anticoagulant poly(ethylene glycol) (PEG)-heparin hydrogel coatings [3] on thermoplastic polyurethane materials. For prolonged antimicrobial activity, the silver-containing starPEG-heparin hydrogel layers were shielded with silver-free hydrogel layers of otherwise similar composition. The resulting multi-layered gel coatings showed long term antiseptic efficacy against Escherichia coli and Staphylococcus epidermidis strains in vitro, and similarly performed well when incubated with freshly drawn human whole blood with respect to hemolysis, platelet activation and plasmatic coagulation. The introduced hydrogel multilayer system thus offers a promising combination of hemocompatibility and long-term antiseptic capacity to meet an important clinical need. PMID:25934292

  9. Analysis of the antimicrobial activities of a chemokine-derived peptide (CDAP-4) on Pseudomonas aeruginosa

    SciTech Connect

    Martinez-Becerra, Francisco; Dominguez-Ramirez, Lenin; Mendoza-Hernandez, Guillermo; Lopez-Vidal, Yolanda; Soldevila, Gloria . E-mail: garciaze@servidor.unam.mx

    2007-04-06

    Chemokines are key molecules involved in the control of leukocyte trafficking. Recently, a novel function as antimicrobial proteins has been described. CCL13 is the only member of the MCP chemokine subfamily displaying antimicrobial activity. To determine Key residues involved in its antimicrobial activity, CCL13 derived peptides were synthesized and tested against several bacterial strains, including Pseudomonas aeruginosa. One of these peptides, corresponding to the C-terminal region of CCL13 (CDAP-4) displayed good antimicrobial activity. Electron microscopy studies revealed remarkable morphological changes after CDAP-4 treatment. By computer modeling, CDAP-4 in {alpha} helical configuration generated a positive electrostatic potential that extended beyond the surface of the molecule. This feature is similar to other antimicrobial peptides. Altogether, these findings indicate that the antimicrobial activity was displayed by CCL13 resides to some extent at the C-terminal region. Furthermore, CDAP-4 could be considered a good antimicrobial candidate with a potential use against pathogens including P. aeruginosa.

  10. Design of nanoemulsion-based delivery systems of natural antimicrobials: effect of the emulsifier.

    PubMed

    Donsì, Francesco; Annunziata, Marianna; Vincensi, Mariarosaria; Ferrari, Giovanna

    2012-06-30

    This work aims at investigating the effect of the nanoemulsion delivery systems on the antimicrobial activity of different essential oil components. Carvacrol, limonene and cinnamaldehyde were encapsulated in the sunflower oil droplets of nanoemulsions prepared by high pressure homogenization and stabilized by different emulsifiers: (a) lecithin, (b) pea proteins, (c) sugar ester and (d) a combination of Tween 20 and glycerol monooleate. The antimicrobial activity was measured against three different microorganisms, such as Escherichia coli, Lactobacillus delbrueckii and Saccharomyces cerevisiae. The measured antimicrobial activity was significantly affected by the formulation of the nanoemulsion, where the different bioactive compounds were encapsulated. In particular, the effect of the delivery systems on the antimicrobial activity was correlated to the concentration of the essential oil components in the aqueous phase in equilibrium with the nanoemulsion droplets, suggesting that the ability of the active molecules to interact with cell membranes is associated to their dissolution in the aqueous phase. These considerations can lead to a more rational design of the nanoemulsion-based delivery systems for essential oils, based on the opportune choice of the emulsifiers in dependence of the desired function of the antimicrobials within the food system. PMID:21763730

  11. Antimicrobial activity of organic thiosulfates (Bunte salts).

    PubMed

    Stefańska, J Z; Starościak, B J; Orzeszko, A; Kazimierczuk, Z

    1998-03-01

    A number of organic thiosulfates (Bunte salts) were prepared from appropriate primary bromides or iodides. In the case of substrates with long aliphatic chains, an addition of benzyltrimethylammonium chloride as phase transfer catalyst was very successful. The Bunte salts obtained were tested for antibacterial and fungicidal activity by means of the agar disc-diffusion method and by assignation of the minimum inhibitory concentrations (MIC). It was found that the microorganisms Proteus vulgaris, Candida albicans and Staphylococcus aureus showed the highest sensitivity. Biological activity of the compounds studied was dependent on the length of the aliphatic chain. Among the investigated compounds, aliphatic thiosulfates with 10-13 carbon atom chain were the most potent. PMID:9547520

  12. Natural products from cyanobacteria with antimicrobial and antitumor activity.

    PubMed

    Silva-Stenico, Maria Estela; Kaneno, Ramon; Zambuzi, Fabiana Albani; Vaz, Marcelo G M V; Alvarenga, Danillo O; Fiore, Marli Fátima

    2013-01-01

    Cyanobacteria are an important source of structurally bioactive metabolites, with cytotoxic, antiviral, anticancer, antimitotic, antimicrobial, specific enzyme inhibition and immunosuppressive activities. This study focused on the antitumor and antimicrobial activities of intra and extracellular cyanobacterial extracts. A total of 411 cyanobacterial strains were screened for antimicrobial activity using a subset of pathogenic bacteria as target. The in vitro antitumor assays were performed with extracts of 24 strains tested against two murine cancer cell lines (colon carcinoma CT-26 and lung cancer 3LL). Intracellular extracts inhibited 49 and 35% of Gram-negative and Gram-positive pathogenic bacterial growth, respectively. Furthermore, the methanolic intracellular extract of Cylindrospermopsis raciborskii CYP011K and Nostoc sp. CENA69 showed inhibitory activity against the cancer cell lines. The extracellular extract from Fischerella sp. CENA213 and M. aeruginosa NPJB-1 exhibited inhibitory activity against 3LL lung cancer cells at 0.8 µg ml⁻¹ and Oxynema sp. CENA135, Cyanobium sp. CENA154, M. aeruginosa NPJB-1 and M. aeruginosa NPLJ-4 presented inhibitory activity against CT26 colon cancer cells at 0.8 µg ml⁻¹. Other extracts were able to inhibit 3LL cell-growth at higher concentrations (20 µg ml⁻¹) such as Nostoc sp. CENA67, Cyanobium sp. CENA154 and M. aeruginosa NPLJ-4, while CT26 cells were inhibited at the same concentration by Nostoc sp. CENA67 and Fischerella sp. CENA213. These extracts presented very low inhibitory activity on human peripheral blood lymphocytes. The results showed that some cyanobacterial strains are a rich source of natural products with potential for pharmacological and biotechnological applications. PMID:24372264

  13. Black cumin (Nigella sativa) and its constituent (thymoquinone): a review on antimicrobial effects

    PubMed Central

    Forouzanfar, Fatemeh; Bazzaz, Bibi Sedigheh Fazly; Hosseinzadeh, Hossein

    2014-01-01

    Nigella sativa seeds have wide therapeutic effects and have been reported to have significant effects against many ailments such as skin diseases, jaundice, gastrointestinal problems, anorexia, conjunctivitis, dyspepsia, rheumatism, diabetes, hypertension, intrinsic hemorrhage, paralysis, amenorrhea, anorexia, asthma, cough, bronchitis, headache, fever, influenza and eczema. Thymoquinone (TQ) is one of the most active constituent and has different beneficial properties. Focus on antimicrobial effects, different extracts of N. sativa as well as TQ, have a broad antimicrobial spectrum including Gram-negative, Gram-positive bacteria, viruses, parasites, schistosoma and fungi. The effectiveness of N. sativa seeds and TQ is variable and depends on species of target microorganisms. The present review paper tries to describe all antimicrobial activities that have been carried out by various researchers. PMID:25859296

  14. Correlation of the antimicrobial activity of salicylaldehydes with broadening of the NMR signal of the hydroxyl proton. Possible involvement of proton exchange processes in the antimicrobial activity.

    PubMed

    Elo, Hannu; Kuure, Matti; Pelttari, Eila

    2015-03-01

    Certain substituted salicylaldehydes are potent antibacterial and antifungal agents and some of them merit consideration as potential chemotherapeutic agents against Candida infections, but their mechanism of action has remained obscure. We report here a distinct correlation between broadening of the NMR signal of the hydroxyl proton of salicylaldehydes and their activity against several types of bacteria and fungi. When proton NMR spectra of the compounds were determined using hexadeuterodimethylsulfoxide as solvent and the height of the OH proton signal was measured, using the signal of the aldehyde proton as an internal standard, it was discovered that a prerequisite of potent antimicrobial activity is that the proton signal is either unobservable or relatively very low, i.e. that it is extremely broadened. Thus, none of the congeners whose OH proton signal was high were potent antimicrobial agents. Some congeners that gave a very low OH signal were, however, essentially inactive against the microbes, indicating that although drastic broadening of the OH signal appears to be a prerequisite, also other (so far unknown) factors are needed for high antimicrobial activity. Because broadening of the hydroxyl proton signal is related to the speed of the proton exchange process(es) involving that proton, proton exchange may be involved in the mechanism of action of the compounds. Further studies are needed to analyze the relative importance of different factors (such as electronic effects, strength of the internal hydrogen bond, co-planarity of the ring and the formyl group) that determine the rates of those processes. PMID:25621992

  15. Antimicrobial and antioxidant activities of unripe papaya.

    PubMed

    Osato, J A; Santiago, L A; Remo, G M; Cuadra, M S; Mori, A

    1993-01-01

    The meat, seed and pulp of Carica papaya Linn., a popular traditional medicinal herb grown in the tropics, was shown by the agar-cup method to be bacteriostatic against several enteropathogens such as Bacillus subtilis, Enterobacter cloacae, Escherichia coli, Salmonella typhi, Staphylococcus aureus, Proteus vulgaris, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The same parts of papaya were unequivocably demonstrated by electron spin resonance spectrometry to scavenge 1,1-diphenyl-2-picrylhydrazyl (5.8 x 10(14) spins/ml), hydroxyl (5.1 x 10(14) spins/ml) and superoxide (1.2 x 10(14) spins/ml) radicals with the seed giving the highest activity at concentrations (IC50) of 2.1, 10.0 and 8.7 mg/ml, respectively. The superoxide dismutase (SOD)-like activity in the meat, seed and pulp amounts to about 32, 98 and 33 units/ml; comparable to those of soybean paste miso, rice bran and baker's yeast. Vitamin C, malic acid, citric acid and glucose are some of the possible antioxidative components in papaya. Our study correlates the bacteriostatic activity of papaya with its scavenging action on superoxide and hydroxyl radicals which could be part of the cellular metabolism of such enteropathogens. This is indicative of the pathophysiological role of these reactive oxygen species in gastrointestinal diseases and papaya's ability to counteract the oxidative stress. PMID:8412504

  16. Antimicrobial activity of Carpolobia lutea extracts and fractions.

    PubMed

    Nwidu, Lucky L; Nwafor, Paul A; Vilegas, Wagner

    2012-01-01

    Carpolobia lutea (G. Don) (Polygalaceae) is a tropical medicinal plant putative in traditional medicines against gonorrhea, gingivitis, infertility, antiulcer and malaria. The present study evaluated the antimicrobial, antifungal and antihelicobacter effects of extracts C. lutea leaf, stem and root. The extracts were examined using the disc-diffusion and Microplates of 96 wells containing Muller-Hinton methods against some bacterial strains: Eschericia coli (ATCC 25922), E. coli (ATCC10418), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Staphyllococus aureus (ATCC 6571), Enterococcus faecalis (ATCC 29212) and Bacillus subtilis (NCTC 8853) and four clinical isolates: one fungi (Candida albican) and three bacteria (Salmonella, Sheigella and staphylococcus aureus). The Gram-positive bacteria: Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Bacillus subtilis (ATCC 19659) and the Gram-negative bacteria: Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Cândida albicans (ATCC 18804) and Helicobacter pylori (ATCC 43504). Some of these extracts were found to be active against some tested strains but activity against H. pylori was >1000mg/ml and good fungistatic activity against C. albican. The MIC against C. albican is in the order n-HF > CHF > ETF= EAF.The order of potency of fraction was the ethanol root > n-HF leaf > ethanol fraction stem > chloroform fraction leaf = ethyl acetate fraction leaf. Polyphenols were demonstrated in ethanol fraction, ethyl acetate fraction, crude ethyl acetate extract and ethanol extract, respectively. These polyphenols isolated may partly explain and support the use of C. lutea for the treatment of infectious diseases in traditional Ibibio medicine of Nigeria. PMID:23983362

  17. In Vitro Antimicrobial Activity of Essential Oil of Thymus schimperi, Matricaria chamomilla, Eucalyptus globulus, and Rosmarinus officinalis

    PubMed Central

    Mekonnen, Awol; Yitayew, Berhanu; Tesema, Alemnesh; Taddese, Solomon

    2016-01-01

    In this study, the in vitro antimicrobial activities of four plant essential oils (T. schimperi, E. globulus, R. officinalis, and M. Chamomilla) were evaluated against bacteria and fungi. The studies were carried out using agar diffusion method for screening the most effective essential oils and agar dilution to determine minimum inhibitory concentration of the essential oils. Results of this study revealed that essential oils of T. schimperi, E. globulus, and R. officinalis were active against bacteria and some fungi. The antimicrobial effect of M. chamomilla was found to be weaker and did not show any antimicrobial activity. The minimum inhibitory concentration values of T. schimperi were <15.75 mg/mL for most of the bacteria and fungi used in this study. The minimum inhibitory concentration values of the other essential oils were in the range of 15.75–36.33 mg/mL against tested bacteria. This study highlighted the antimicrobial activity of the essential oil of E. globulus, M. chamomilla, T. Schimperi, and R. officinalis. The results indicated that T. schimperi have shown strong antimicrobial activity which could be potential candidates for preparation of antimicrobial drug preparation. PMID:26880928

  18. In Vitro Antimicrobial Activity of Essential Oil of Thymus schimperi, Matricaria chamomilla, Eucalyptus globulus, and Rosmarinus officinalis.

    PubMed

    Mekonnen, Awol; Yitayew, Berhanu; Tesema, Alemnesh; Taddese, Solomon

    2016-01-01

    In this study, the in vitro antimicrobial activities of four plant essential oils (T. schimperi, E. globulus, R. officinalis, and M. Chamomilla) were evaluated against bacteria and fungi. The studies were carried out using agar diffusion method for screening the most effective essential oils and agar dilution to determine minimum inhibitory concentration of the essential oils. Results of this study revealed that essential oils of T. schimperi, E. globulus, and R. officinalis were active against bacteria and some fungi. The antimicrobial effect of M. chamomilla was found to be weaker and did not show any antimicrobial activity. The minimum inhibitory concentration values of T. schimperi were <15.75 mg/mL for most of the bacteria and fungi used in this study. The minimum inhibitory concentration values of the other essential oils were in the range of 15.75-36.33 mg/mL against tested bacteria. This study highlighted the antimicrobial activity of the essential oil of E. globulus, M. chamomilla, T. Schimperi, and R. officinalis. The results indicated that T. schimperi have shown strong antimicrobial activity which could be potential candidates for preparation of antimicrobial drug preparation. PMID:26880928

  19. High Antimicrobial Activity and Low Human Cell Cytotoxicity of Core-Shell Magnetic Nanoparticles Functionalized with an Antimicrobial Peptide.

    PubMed

    Maleki, Hajar; Rai, Akhilesh; Pinto, Sandra; Evangelista, Marta; Cardoso, Renato M S; Paulo, Cristiana; Carvalheiro, Tiago; Paiva, Artur; Imani, Mohammad; Simchi, Abdolreza; Durães, Luísa; Portugal, António; Ferreira, Lino

    2016-05-11

    Superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with antimicrobial agents are promising infection-targeted therapeutic platforms when coupled with external magnetic stimuli. These antimicrobial nanoparticles (NPs) may offer advantages in fighting intracellular pathogens as well as biomaterial-associated infections. This requires the development of NPs with high antimicrobial activity without interfering with the biology of mammalian cells. Here, we report the preparation of biocompatible antimicrobial SPION@gold core-shell NPs based on covalent immobilization of the antimicrobial peptide (AMP) cecropin melittin (CM) (the conjugate is named AMP-NP). The minimal inhibitory concentration (MIC) of the AMP-NP for Escherichia coli was 0.4 μg/mL, 10-times lower than the MIC of soluble CM. The antimicrobial activity of CM depends on the length of the spacer between the CM and the NP. AMP-NPs are taken up by endothelial (between 60 and 170 pg of NPs per cell) and macrophage (between 18 and 36 pg of NPs per cell) cells and accumulate preferentially in endolysosomes. These NPs have no significant cytotoxic and pro-inflammatory activities for concentrations up to 200 μg/mL (at least 100 times higher than the MIC of soluble CM). Our results in membrane models suggest that the selectivity of AMP-NPs for bacteria and not eukaryotic membranes is due to their membrane compositions. The AMP-NPs developed here open new opportunities for infection-site targeting. PMID:27074633

  20. The Activity of Antimicrobial Surfaces Varies by Testing Protocol Utilized

    PubMed Central

    Campos, Matias D.; Zucchi, Paola C.; Phung, Ann; Leonard, Steven N.; Hirsch, Elizabeth B.

    2016-01-01

    Background Contaminated hospital surfaces are an important source of nosocomial infections. A major obstacle in marketing antimicrobial surfaces is a lack of efficacy data based on standardized testing protocols. Aim We compared the efficacy of multiple testing protocols against several “antimicrobial” film surfaces. Methods Four clinical isolates were used: one Escherichia coli, one Klebsiella pneumoniae, and two Staphylococcus aureus strains. Two industry methods (modified ISO 22196 and ASTM E2149), a “dried droplet”, and a “transfer” method were tested against two commercially available antimicrobial films, one film in development, an untreated control, and a positive (silver) control film. At 2 (only ISO) and 24 hours following inoculation, bacteria were collected from film surfaces and enumerated. Results Compared to untreated films in all protocols, there were no significant differences in recovery on either commercial brand at 2 or 24 hours after inoculation. The silver surface demonstrated significant microbicidal activity (mean loss 4.9 Log10 CFU/ml) in all methods and time points with the exception of 2 hours in the ISO protocol and the transfer method. Using our novel droplet method, no differences between placebo and active surfaces were detected. The surface in development demonstrated variable activity depending on method, organism, and time point. The ISO demonstrated minimal activity at 2 hours but significant activity at 24 hours (mean 4.5 Log10 CFU/ml difference versus placebo). The ASTEM protocol exhibited significant differences in recovery of staphylococci (mean 5 Log10 CFU/ml) but not Gram-negative isolates (10 fold decrease). Minimal activity was observed with this film in the transfer method. Conclusions Varying results between protocols suggested that efficacy of antimicrobial surfaces cannot be easily and reproducibly compared. Clinical use should be considered and further development of representative methods is needed. PMID

  1. Antimicrobial activity and identification of potential antimicrobial compounds from aquatic pteridophyte, Azolla microphylla Kaulf.

    PubMed

    Abraham, G; Yadav, R K; Kaushik, G K

    2015-04-01

    Azolla microphylla Kaulf. is an aquatic nitrogen fixing pteridophyte commonly found in aquatic habitats including paddy fields. Methanolic extract of the fronds of A. microphylla was subjected to partial purification by solvent partitioning with diethyl ether and ethyl acetate followed by hydrolysis, and further partitioning with ethyl acetate. The two fractions, thus obtained were tested for antibacterial activity. It was observed that the ethyl acetate fraction inhibited the growth of the pathogenic bacterium Xanthomonas oryzae. The GC-MS analysis of the ethyl acetate fraction showed several prominent peaks with retention time ranging from 8.83 to 45.54 min. A comparison of these peaks with the GC-MS libraries revealed that it could be eicosenes and heptadecanes with potential of antimicrobial activity. PMID:26011985

  2. Antimicrobial activity of chitosan derivatives containing N-quaternized moieties in its backbone: a review.

    PubMed

    Martins, Alessandro F; Facchi, Suelen P; Follmann, Heveline D M; Pereira, Antonio G B; Rubira, Adley F; Muniz, Edvani C

    2014-01-01

    Chitosan, which is derived from a deacetylation reaction of chitin, has attractive antimicrobial activity. However, chitosan applications as a biocide are only effective in acidic medium due to its low solubility in neutral and basic conditions. Also, the positive charges carried by the protonated amine groups of chitosan (in acidic conditions) that are the driving force for its solubilization are also associated with its antimicrobial activity. Therefore, chemical modifications of chitosan are required to enhance its solubility and broaden the spectrum of its applications, including as biocide. Quaternization on the nitrogen atom of chitosan is the most used route to render water-soluble chitosan-derivatives, especially at physiological pH conditions. Recent reports in the literature demonstrate that such chitosan-derivatives present excellent antimicrobial activity due to permanent positive charge on nitrogen atoms side-bonded to the polymer backbone. This review presents some relevant work regarding the use of quaternized chitosan-derivatives obtained by different synthetic paths in applications as antimicrobial agents. PMID:25402643

  3. Comparative study of volatile oil content and antimicrobial activity of pecan cultivars growing in Egypt.

    PubMed

    El Hawary, Seham S; Zaghloul, Soumaya S; El Halawany, Ali M; El Bishbishy, Mahitab H

    2013-11-01

    The volatile oils obtained from the leaves of four pecan cultivars growing in Egypt were evaluated for their chemical composition and antimicrobial activity. The selected cultivars (cv.) were Carya illinoinensis (Wangneh.) K. Koch. cv. Wichita, C. illinoinensis cv. Western Schley, C. illinoinensis cv. Cherokee, and C. illinoinensis cv. Sioux. The gas chromatography-mass spectrometry analyses revealed that the volatile oils from samples of the different cultivars differ in composition and percentage of their components. β-Curcumene was found as the major constituent of the cv. Wichita oil, whereas germacrene D was the major component of cv. Sioux, cv. Cherokee, and cv. Western Schley. The antimicrobial activity was assayed using the Kirby-Bauer Method by measuring the zone of inhibition of growth. All volatile oils displayed an antimicrobial activity against the tested bacterial strains. On the other hand, only the volatile oil of cv. Wichita showed an antifungal effect on Aspergillus flavus. This work has identified candidates of volatile oils for future in vivo studies to develop antibiotic substitutes for the diminution of human and animal pathogenic bacteria. Nevertheless, the variations of the volatile oil components and antimicrobial potencies of the different studied cultivars, necessitate identifying the cultivars used in future studies. PMID:24180553

  4. Antimicrobial Activity of Chitosan Derivatives Containing N-Quaternized Moieties in Its Backbone: A Review

    PubMed Central

    Martins, Alessandro F.; Facchi, Suelen P.; Follmann, Heveline D. M.; Pereira, Antonio G. B.; Rubira, Adley F.; Muniz, Edvani C.

    2014-01-01

    Chitosan, which is derived from a deacetylation reaction of chitin, has attractive antimicrobial activity. However, chitosan applications as a biocide are only effective in acidic medium due to its low solubility in neutral and basic conditions. Also, the positive charges carried by the protonated amine groups of chitosan (in acidic conditions) that are the driving force for its solubilization are also associated with its antimicrobial activity. Therefore, chemical modifications of chitosan are required to enhance its solubility and broaden the spectrum of its applications, including as biocide. Quaternization on the nitrogen atom of chitosan is the most used route to render water-soluble chitosan-derivatives, especially at physiological pH conditions. Recent reports in the literature demonstrate that such chitosan-derivatives present excellent antimicrobial activity due to permanent positive charge on nitrogen atoms side-bonded to the polymer backbone. This review presents some relevant work regarding the use of quaternized chitosan-derivatives obtained by different synthetic paths in applications as antimicrobial agents. PMID:25402643

  5. Anti-inflammatory, Antioxidant and Antimicrobial Effects of Artemisinin Extracts from Artemisia annua L.

    PubMed Central

    Kim, Wan-Su; Choi, Woo Jin; Lee, Sunwoo; Kim, Woo Joong; Lee, Dong Chae; Sohn, Uy Dong; Shin, Hyoung-Shik

    2015-01-01

    The anti-inflammatory, antioxidant, and antimicrobial properties of artemisinin derived from water, methanol, ethanol, or acetone extracts of Artemisia annua L. were evaluated. All 4 artemisinin-containing extracts had anti-inflammatory effects. Of these, the acetone extract had the greatest inhibitory effect on lipopolysaccharide-induced nitric oxide (NO), prostaglandin E2 (PGE2), and proinflammatory cytokine (IL-1β , IL-6, and IL-10) production. Antioxidant activity evaluations revealed that the ethanol extract had the highest free radical scavenging activity, (91.0±3.2%), similar to α-tocopherol (99.9%). The extracts had antimicrobial activity against the periodontopathic microorganisms Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum subsp. animalis, Fusobacterium nucleatum subsp. polymorphum, and Prevotella intermedia. This study shows that Artemisia annua L. extracts contain anti-inflammatory, antioxidant, and antimicrobial substances and should be considered for use in pharmaceutical products for the treatment of dental diseases. PMID:25605993

  6. Antimicrobial Activity of Medicated Soaps Commonly Used By Dar es Salaam Residents in Tanzania

    PubMed Central

    Mwambete, K. D.; Lyombe, F.

    2011-01-01

    An in vitro evaluation of the anti-microbial activity of medicated soaps was conducted using ditch-plate and hand washing techniques. Strains of reference microbes namely Candida albicans (ATCC90028), Staphylococcus aureus (ATCC25923), Pseudomonas aureginosa (ATCC27853) and Escherichia coli (ATCC25922) were tested at three different soaps’ concentrations (1.0, 4.0 and 8.0 mg/ml). A total of 16 medicated soaps were assayed for their antimicrobial efficacy. Of these, 13 were medicated and 3 non-medicated soaps, which served as control. Ciprofloxacin and ketaconazole were employed as positive controls. Label disclosure for the soaps’ ingredients and other relevant information were absorbed. The most common antimicrobial active ingredients were triclosan, trichloroxylenol and trichlorocarbanilide. ANOVA for means of zones of inhibition revealed variability of antimicrobial activity among the medicated soaps. Positive correlation (r=0.318; P<0.01) between zones of inhibition and soaps’ concentrations was evidenced. Hand washing frequencies positively correlated with microbial counts. Roberts® soap exhibited the largest zone of inhibition (34 mm) on S. aureus. Candida albicans was the least susceptible microbe. Regency® and Dalan® exhibited the least zone of inhibition on the tested bacteria. Protex®, Roberts®, Family® and Protector® were equally effective (P<0.01) against S. aureus. In conclusion, majority of the assayed medicated soaps have satisfactory antibacterial activity; though lack antifungal effect with exception of Linda® liquid soap. The hand washing technique has proved to be inappropriate for evaluation of soaps’ antimicrobial efficacy due to presence of the skin microflora. PMID:22131630

  7. Antimicrobial Activity of Medicated Soaps Commonly Used By Dar es Salaam Residents in Tanzania.

    PubMed

    Mwambete, K D; Lyombe, F

    2011-01-01

    An in vitro evaluation of the anti-microbial activity of medicated soaps was conducted using ditch-plate and hand washing techniques. Strains of reference microbes namely Candida albicans (ATCC90028), Staphylococcus aureus (ATCC25923), Pseudomonas aureginosa (ATCC27853) and Escherichia coli (ATCC25922) were tested at three different soaps' concentrations (1.0, 4.0 and 8.0 mg/ml). A total of 16 medicated soaps were assayed for their antimicrobial efficacy. Of these, 13 were medicated and 3 non-medicated soaps, which served as control. Ciprofloxacin and ketaconazole were employed as positive controls. Label disclosure for the soaps' ingredients and other relevant information were absorbed. The most common antimicrobial active ingredients were triclosan, trichloroxylenol and trichlorocarbanilide. ANOVA for means of zones of inhibition revealed variability of antimicrobial activity among the medicated soaps. Positive correlation (r=0.318; P<0.01) between zones of inhibition and soaps' concentrations was evidenced. Hand washing frequencies positively correlated with microbial counts. Roberts(®) soap exhibited the largest zone of inhibition (34 mm) on S. aureus. Candida albicans was the least susceptible microbe. Regency(®) and Dalan(®) exhibited the least zone of inhibition on the tested bacteria. Protex(®), Roberts(®), Family(®) and Protector(®) were equally effective (P<0.01) against S. aureus. In conclusion, majority of the assayed medicated soaps have satisfactory antibacterial activity; though lack antifungal effect with exception of Linda(®) liquid soap. The hand washing technique has proved to be inappropriate for evaluation of soaps' antimicrobial efficacy due to presence of the skin microflora. PMID:22131630

  8. In vitro antimicrobial activity of ethanolic fractions of Cryptolepis sanguinolenta

    PubMed Central

    2012-01-01

    Background Following claims that some plants have antimicrobial activities against infectious microbes, the in vitro antimicrobial activities of different solvent fractions of ethanolic extract of Cryptolepis sanguinolenta were evaluated against eight standard bacteria and clinical isolates. Methods The solvent partitioning protocol involving ethanol, petroleum ether, chloroform, ethyl acetate and water, was used to extract various fractions of dried pulverized Cryptolepis sanguinolenta roots. Qualitative phyto-constituents screening was performed on the ethanol extract, chloroform fraction and the water fraction. The Kirby Bauer disk diffusion method was employed to ascertain the antibiogram of the test organisms while the agar diffusion method was used to investigate the antimicrobial properties of the crude plant extracts. The microplate dilution method aided in finding the MICs while the MBCs were obtained by the method of Nester and friends. The SPSS 16.0 version was used to analyze the percentages of inhibitions and bactericidal activities. Results The phytochemical screening revealed the presence of alkaloids, reducing sugars, polyuronides, anthocyanosides and triterpenes. The ethanol extract inhibited 5 out of 8 (62.5%) of the standard organisms and 6 out of 8 (75%) clinical isolates. The petroleum ether fraction inhibited 4 out of 8 (50%) of the standard microbes and 1 out of 8 (12.5%) clinical isolates. It was also observed that the chloroform fraction inhibited the growth of all the organisms (100%). Average inhibition zones of 14.0 ± 1.0 mm to 24.67 ± 0.58 mm was seen in the ethyl acetate fraction which halted the growth of 3 (37.5%) of the standard organisms. Inhibition of 7 (87.5%) of standard strains and 6 (75%) of clinical isolates were observed in the water fraction. The chloroform fraction exhibited bactericidal activity against all the test organisms while the remaining fractions showed varying degrees of bacteriostatic activity

  9. [Antimicrobial activity of various algae of the Panamanian Atlantic coast].

    PubMed

    Gupta, M P; Gómez, N E; Santana, A I; Solis, P N; Palacios, G

    1991-01-01

    The methanolic extracts in 5 of 7 alagae from the Atlantic coast of Panama: Caulerpa racemosa, Halimeda opuntia, Gelidiela acerosa, Laurencia papillosa y Acanthophora spicifera, showed antimicrobial activity against Staphylococcus aureus and Bacillus subtilis in a concentration of 50 mg/ml by the cylinder plate method. None of the algae studies showed activity against Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans. The content of agar in Acanthophora spicifera was found to be the highest (33.5%) of all the species studied. PMID:2024058

  10. Antimicrobial activity of lactoferrin against foodborne pathogenic bacteria incorporated into edible chitosan film.

    PubMed

    Brown, Cynthia A; Wang, Baowu; Oh, Jun-Hyun

    2008-02-01

    The objectives of this research were to develop and characterize edible chitosan film containing lactoferrin as a natural antimicrobial agent, and to investigate the combination effects of lactoferrin with lysozyme in chitosan film against the growth of Escherichia coli O157:H7 and Listeria monocytogenes. Chitosan films containing lactoferrin, lysozyme, or nisin were fabricated, and the antimicrobial concentrations were 0.5, 1, or 2 mg in a circular disc of chitosan film. Three concentrations of lactoferrin or EDTA (0.28, 0.56, or 1.12 mg per disc) were also incorporated into the chitosan film containing lysozyme to investigate the combination effects of lactoferrin. The water barrier properties of the chitosan films containing lactoferrin were characterized. The antimicrobial activities against E. coli O157:H7 and L. monocytogenes were determined using the agar diffusion assay and cell count assay. The chitosan films containing lactoferrin less than 1 mg per disc did not alter the water vapor permeability of the chitosan film. Although the film containing lysozyme exhibited significant antimicrobial activity, the incorporation of lactoferrin alone into chitosan film did not exhibit significant antimicrobial activity against both E. coli O157:H7 and L. monocytogenes. However, the combination of lactoferrin with lysozyme-containing chitosan film significantly decreased the growth of E. coli O157:H7, exhibiting a comparable effect to that of the combination of EDTA with lysozyme (P < 0.05). Furthermore, the combination of lactoferrin with lysozyme in chitosan film exhibited greater reduction in the growth of L. monocytogenes than did the combination EDTA with lysozyme, resulting in an approximate 3-log reduction. PMID:18326181

  11. Evaluation of antimicrobial activity of selected plant extracts by rapid XTT colorimetry and bacterial enumeration.

    PubMed

    Al-Bakri, Amal G; Afifi, Fatma U

    2007-01-01

    The aim of this study was to screen and evaluate the antimicrobial activity of indigenous Jordanian plant extracts, dissolved in dimethylsulfoxide, using the rapid XTT assay and viable count methods. XTT rapid assay was used for the initial screening of antimicrobial activity for the plant extracts. Antimicrobial activity of potentially active plant extracts was further assessed using the "viable plate count" method. Four degrees of antimicrobial activity (high, moderate, weak and inactive) against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, respectively, were recorded. The plant extracts of Hypericum triquetrifolium, Ballota undulata, Ruta chalepensis, Ononis natrix, Paronychia argentea and Marrubium vulgare had shown promising antimicrobial activity. This study showed that while both XTT and viable count methods are comparable when estimating the overall antimicrobial activity of experimental substances, there is no strong linear correlation between the two methods. PMID:16831479

  12. Enhanced antimicrobial activity of peptide-cocktails against common bacterial contaminants of ex vivo stored platelets.

    PubMed

    Mohan, K V K; Rao, S Sainath; Gao, Y; Atreya, C D

    2014-01-01

    Bacterial contamination of blood components such as ex vivo-stored platelets is a major safety risk in transfusion medicine. We have recently shown that synthetic antimicrobial peptides named PD1-PD4 derived from the thrombin-induced human platelet-derived antimicrobial proteins, and repeats of Arg-Trp (RW1-RW5) demonstrate microbicidal activity against selected bacteria and viruses. In the present study, we selected PD3, PD4, RW2, RW3 and RW4 and evaluated each individual peptide and their various combinations to see whether the cocktail regimen enhances the antimicrobial activity above and over the individual peptides. Stored platelet or plasma samples spiked with known titres of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus cereus were treated with either individual peptides or with peptides in various combinations. Analyses revealed that individual peptides show moderate microbicidal activity (10- to 100-fold reduction) against the tested bacteria relative to their combined regimen. The peptide combinations (RW2 + RW4, RW2 + RW3 + RW4 and PD4 + RW3 + RW4) on the other hand enhanced the microbicidal activity (c.10 000-fold reduction) and revealed a minimal inhibitory concentration of 5 μM. Time-kill kinetics indicated that these three peptide combinations exhibited enhanced antimicrobial activity bringing about a 100-fold reduction of bacterial titres within 20 min of incubation. The present study therefore demonstrates the synergistic effect of antimicrobial peptides when used in combinations and provides a proof-of-concept of its potential application as a molecular tool towards pathogen reduction and further extends the possibility of using peptide combinatorial therapeutics as broad-spectrum antibiotics or as alternatives to combat drug-resistant bacteria. PMID:23926880

  13. Antimicrobial activity of the solvent fractions from Bulbine natalensis Tuber.

    PubMed

    Yakubu, M T; Mostafa, M; Ashafa, A O T; Afolayan, A J

    2012-01-01

    Bulbine natalensis Baker has been acclaimed to be used as an antimicrobial agent in the folklore medicine of South Africa without scientific evidence to substantiate or refute this claim. In view of this, the in vitro antimicrobial activity of solvent fractions (ethanol, ethyl acetate, n-butanol and water) from Bulbine natalensis Tuber against 4 Gram positive and 12 Gram negative bacteria as well as 3 fungal species were investigated using agar dilution. The ethanolic extract, n-butanol and ethyl acetate fractions inhibited 75, 87.5 and 100% respectively of the bacterial species in this study. The ethanolic, n-butanol and ethyl acetate fractions produced growth inhibition at MIC range of 1-10, 3-10 as well as 1 and 5 mg/ml respectively whereas the water fraction did not inhibit the growth of any of the bacterial species. Again, it was only the ethyl acetate fraction that inhibited the growth of Shigelli flexneri, Staphyloccus aureus and Escherichia coli. The ethanolic, ethyl acetate and n-butanolic fractions dose dependently inhibited the growth of Aspergillus niger and A. flavus whereas the water fraction produced 100% growth inhibition of the Aspergillus species at all the doses investigated. In contrast, no growth inhibition was produced on Candida albicans. The growth inhibition produced by the solvent fractions of B. natalensis Tuber in this study thus justifies the acclaimed use of the plant as an antimicrobial agent. The ethyl acetate fraction was the most potent. PMID:23983381

  14. Characteristics and antimicrobial activity of copper-based materials

    NASA Astrophysics Data System (ADS)

    Li, Bowen

    In this study, copper vermiculite was synthesized, and the characteristics, antimicrobial effects, and chemical stability of copper vermiculite were investigated. Two types of copper vermiculite materials, micron-sized copper vermiculite (MCV) and exfoliated copper vermiculite (MECV), are selected for this research. Since most of the functional fillers used in industry products, such as plastics, paints, rubbers, papers, and textiles prefer micron-scaled particles, micron-sized copper vermiculite was prepared by jet-milling vermiculite. Meanwhile, since the exfoliated vermiculite has very unique properties, such as high porosity, specific surface area, high aspect ratio of laminates, and low density, and has been extensively utilized as a functional additives, exfoliated copper vermiculite also was synthesized and investigated. The antibacterial efficiency of copper vermiculite was qualitatively evaluated by the diffusion methods (both liquid diffusion and solid diffusion) against the most common pathogenic species: Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Klebsiella pneumoniae (K. pneumoniae). The result showed that the release velocity of copper from copper vermiculite is very slow. However, copper vermiculite clearly has excellent antibacterial efficiency to S. aureus, K. pneumoniae and E. coli. The strongest antibacterial ability of copper vermiculite is its action on S. aureus. The antibacterial efficiency of copper vermiculite was also quantitatively evaluated by determining the reduction rate (death rate) of E. coli versus various levels of copper vermiculite. 10 ppm of copper vermiculite in solution is sufficient to reduce the cell population of E. coli, while the untreated vermiculite had no antibacterial activity. The slow release of copper revealed that the antimicrobial effect of copper vermiculite was due to the strong interactions between copper ions and bacteria cells. Exfoliated copper vermiculite has even stronger

  15. Antimicrobial and antiproliferative activities of stingless bee Melipona scutellaris geopropolis

    PubMed Central

    2013-01-01

    Background Geopropolis is a type of propolis containing resin, wax, and soil, collected by threatened stingless bee species native to tropical countries and used in folk medicine. However, studies concerning the biological activity and chemical composition of geopropolis are scarce. In this study, we evaluated the antimicrobial and antiproliferative activity of the ethanolic extract of geopropolis (EEGP) collected by Melipona scutellaris and its bioactive fraction against important clinical microorganisms as well as their in vitro cytotoxicity and chemical profile. Methods The antimicrobial activity of EEGP and fractions was examined by determining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against six bacteria strains as well as their ability to inhibit Streptococcus mutans biofilm adherence. Total growth inhibition (TGI) was chosen to assay the antiproliferative activity of EEGP and its bioactive fraction against normal and cancer cell lines. The chemical composition of M. scutellaris geopropolis was identified by reversed-phase high-performance liquid chromatography and gas chromatography–mass spectrometry. Results EEGP significantly inhibited the growth of Staphylococcus aureus strains and S. mutans at low concentrations, and its hexane fraction (HF) presented the highest antibacterial activity. Also, both EEGP and HF inhibited S. mutans biofilm adherence (p < 0.05) and showed selectivity against human cancer cell lines, although only HF demonstrated selectivity at low concentrations. The chemical analyses performed suggest the absence of flavonoids and the presence of benzophenones as geopropolis major compounds. Conclusions The empirical use of this unique type of geopropolis by folk medicine practitioners was confirmed in the present study, since it showed antimicrobial and antiproliferative potential against the cancer cell lines studied. It is possible that the major compounds found in this type of

  16. Snake Cathelicidin NA-CATH and Smaller Helical Antimicrobial Peptides Are Effective against Burkholderia thailandensis

    PubMed Central

    Blower, Ryan J.; Barksdale, Stephanie M.; van Hoek, Monique L.

    2015-01-01

    Burkholderia thailandensis is a Gram-negative soil bacterium used as a model organism for B. pseudomallei, the causative agent of melioidosis and an organism classified category B priority pathogen and a Tier 1 select agent for its potential use as a biological weapon. Burkholderia species are reportedly “highly resistant” to antimicrobial agents, including cyclic peptide antibiotics, due to multiple resistance systems, a hypothesis we decided to test using antimicrobial (host defense) peptides. In this study, a number of cationic antimicrobial peptides (CAMPs) were tested in vitro against B. thailandensis for both antimicrobial activity and inhibition of biofilm formation. Here, we report that the Chinese cobra (Naja atra) cathelicidin NA-CATH was significantly antimicrobial against B. thailandensis. Additional cathelicidins, including the human cathelicidin LL-37, a sheep cathelicidin SMAP-29, and some smaller ATRA peptide derivatives of NA-CATH were also effective. The D-enantiomer of one small peptide (ATRA-1A) was found to be antimicrobial as well, with EC50 in the range of the L-enantiomer. Our results also demonstrate that human alpha-defensins (HNP-1 & -2) and a short beta-defensin-derived peptide (Peptide 4 of hBD-3) were not bactericidal against B. thailandensis. We also found that the cathelicidin peptides, including LL-37, NA-CATH, and SMAP-29, possessed significant ability to prevent biofilm formation of B. thailandensis. Additionally, we show that LL-37 and its D-enantiomer D-LL-37 can disperse pre-formed biofilms. These results demonstrate that although B. thailandensis is highly resistant to many antibiotics, cyclic peptide antibiotics such as polymyxin B, and defensing peptides, some antimicrobial peptides including the elapid snake cathelicidin NA-CATH exert significant antimicrobial and antibiofilm activity towards B. thailandensis. PMID:26196513

  17. Snake Cathelicidin NA-CATH and Smaller Helical Antimicrobial Peptides Are Effective against Burkholderia thailandensis.

    PubMed

    Blower, Ryan J; Barksdale, Stephanie M; van Hoek, Monique L

    2015-01-01

    Burkholderia thailandensis is a Gram-negative soil bacterium used as a model organism for B. pseudomallei, the causative agent of melioidosis and an organism classified category B priority pathogen and a Tier 1 select agent for its potential use as a biological weapon. Burkholderia species are reportedly "highly resistant" to antimicrobial agents, including cyclic peptide antibiotics, due to multiple resistance systems, a hypothesis we decided to test using antimicrobial (host defense) peptides. In this study, a number of cationic antimicrobial peptides (CAMPs) were tested in vitro against B. thailandensis for both antimicrobial activity and inhibition of biofilm formation. Here, we report that the Chinese cobra (Naja atra) cathelicidin NA-CATH was significantly antimicrobial against B. thailandensis. Additional cathelicidins, including the human cathelicidin LL-37, a sheep cathelicidin SMAP-29, and some smaller ATRA peptide derivatives of NA-CATH were also effective. The D-enantiomer of one small peptide (ATRA-1A) was found to be antimicrobial as well, with EC50 in the range of the L-enantiomer. Our results also demonstrate that human alpha-defensins (HNP-1 & -2) and a short beta-defensin-derived peptide (Peptide 4 of hBD-3) were not bactericidal against B. thailandensis. We also found that the cathelicidin peptides, including LL-37, NA-CATH, and SMAP-29, possessed significant ability to prevent biofilm formation of B. thailandensis. Additionally, we show that LL-37 and its D-enantiomer D-LL-37 can disperse pre-formed biofilms. These results demonstrate that although B. thailandensis is highly resistant to many antibiotics, cyclic peptide antibiotics such as polymyxin B, and defensing peptides, some antimicrobial peptides including the elapid snake cathelicidin NA-CATH exert significant antimicrobial and antibiofilm activity towards B. thailandensis. PMID:26196513

  18. Antimicrobial and antioxidant activities of alcoholic extracts of Rumex dentatus L.

    PubMed

    Humeera, Nisa; Kamili, Azra N; Bandh, Suhaib A; Amin, Shajr-ul-; Lone, Bashir A; Gousia, Nisa

    2013-04-01

    In-vitro antimicrobial and antioxidant activities of various concentrations ranging from 150 to 500 μg/ml of alcoholic (methanol and ethanol) extracts of Rumex dentatus were analyzed on different clinical bacterial strains (Shigella flexneri, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus) and fungal strains (Aspergillus versicolor, Aspergillus flavus, Acremonium spp., Penicillium dimorphosporum, Candida albicans, Candida kruesie, Candida parapsilosis) using agar disk diffusion method and broth dilution method (MIC and MBC determination) for antimicrobial activity and DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, Riboflavin photo-oxidation assay, deoxyribose assay, lipid peroxidation assay for antioxidant activity. The extracts showed maximum inhibitory effect against K. pneumonia and P. aeruginosa with no activity against S. typhimurium from among the bacterial strains while as in case of the fungal strains the maximum effect was observed against C. albicans by both the extracts. MIC and MBC values determined for active fractions of the extracts against some bacterial strains (S. flexneri, K. pneumonia and E. coli) revealed that the test organisms were inhibited by all the extracts with methanol showing lower values of both MIC and MBC indicating it as a better antimicrobial agent. The antioxidant activity showed that the extracts exhibited scavenging effect in concentration-dependent manner on superoxide anion radicals and hydroxyl radicals leading to the conclusion that the plant has got a broad spectrum antimicrobial and antioxidant activity and could be a potential alternative for treating various diseases. PMID:23415966

  19. Antimicrobial activity of phenolics and glucosinolate hydrolysis products and their synergy with streptomycin against pathogenic bacteria.

    PubMed

    Saavedra, Maria J; Borges, Anabela; Dias, Carla; Aires, Alfredo; Bennett, Richard N; Rosa, Eduardo S; Simões, Manuel

    2010-05-01

    The purpose of the present study was to evaluate the in vitro antibacterial effects of different classes of important and common dietary phytochemicals (5 simple phenolics - tyrosol, gallic acid, caffeic acid, ferulic acid, and chlorogenic acid; chalcone - phloridzin; flavan-3-ol - (-) epicatechin; seco-iridoid - oleuropein glucoside; 3 glucosinolate hydrolysis products - allylisothiocyanate, benzylisothiocyanate and 2-phenylethylisothiocyanate) against Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes and Staphylococcus aureus. Another objective of this study was to evaluate the effects of dual combinations of streptomycin with the different phytochemicals on antibacterial activity. A disc diffusion assay was used to evaluate the antibacterial activity of the phytochemicals and 3 standard antibiotics (ciprofloxacin, gentamicin and streptomycin) against the four bacteria. The antimicrobial activity of single compounds and dual combinations (streptomycin-phytochemicals) were quantitatively assessed by measuring the inhibitory halos. The results showed that all of the isothiocyanates had significant antimicrobial activities, while the phenolics were much less efficient. No antimicrobial activity was observed with phloridzin. In general P. aeruginosa was the most sensitive microorganism and L. monocytogenes the most resistant. The application of dual combinations demonstrated synergy between streptomycin and gallic acid, ferulic acid, chlorogenic acid, allylisothiocyanate and 2-phenylethylisothiocyanate against the Gram-negative bacteria. In conclusion, phytochemical products and more specifically the isothiocyanates were effective inhibitors of the in vitro growth of the Gram-negative and Gram-positive pathogenic bacteria. Moreover, they can act synergistically with less efficient antibiotics to control bacterial growth. PMID:20632977

  20. Synthesis, antimicrobial, and antiproliferative activities of substituted phenylfuranylnicotinamidines

    PubMed Central

    Youssef, Magdy M; Arafa, Reem K; Ismail, Mohamed A

    2016-01-01

    This research work deals with the design and synthesis of a series of substituted phenylfuranylnicotinamidines 4a–i. Facile preparation of the target compounds was achieved by Suzuki coupling-based synthesis of the nitrile precursors 3a–i, followed by their conversion to the corresponding nicotinamidines 4a–i utilizing LiN(TMS)2. The antimicrobial activities of the newly synthesized nicotinamidine derivatives were evaluated against the Gram-negative bacterial strains Escherichia coli and Pseudomonas aeruginosa as well as the Gram-positive bacterial strains Staphylococcus aureus and Bacillus megaterium. The minimum inhibitory concentration values of nicotinamidines against all tested microorganisms were in the range of 10–20 μM. In specific, compounds 4a and 4b showed excellent minimum inhibitory concentration values of 10 μM against Staphylococcus aureus bacterial strain and were similar to ampicillin as an antibacterial reference. On the other hand, selected nicotinamidine derivatives were biologically screened for their cytotoxic activities against a panel of 60 cell lines representing nine types of human cancer at a single high dose at National Cancer Institute, Bethesda, MD, USA. Nicotinamidines showing promising activities were further assessed in a five-dose screening assay to determine their compound concentration causing 50% growth inhibition of tested cell (GI50), compound concentration causing 100% growth inhibition of tested cell (TGI), and compound concentration causing 50% lethality of tested cell (LC50) values. Structure-activity relationship studies demonstrated that the activity of members of this series can be modulated from cytostatic to cytotoxic based on the substitution pattern/nature on the terminal phenyl ring. The most active compound was found to be 4e displaying a submicromolar GI50 value of 0.83 μM, with TGI and LC50 values of 2.51 and 100 μM, respectively. Finally, the possible underlying mechanism of action of this series of

  1. Synthesis, antimicrobial, and antiproliferative activities of substituted phenylfuranylnicotinamidines.

    PubMed

    Youssef, Magdy M; Arafa, Reem K; Ismail, Mohamed A

    2016-01-01

    This research work deals with the design and synthesis of a series of substituted phenylfuranylnicotinamidines 4a-i. Facile preparation of the target compounds was achieved by Suzuki coupling-based synthesis of the nitrile precursors 3a-i, followed by their conversion to the corresponding nicotinamidines 4a-i utilizing LiN(TMS)2. The antimicrobial activities of the newly synthesized nicotinamidine derivatives were evaluated against the Gram-negative bacterial strains Escherichia coli and Pseudomonas aeruginosa as well as the Gram-positive bacterial strains Staphylococcus aureus and Bacillus megaterium. The minimum inhibitory concentration values of nicotinamidines against all tested microorganisms were in the range of 10-20 μM. In specific, compounds 4a and 4b showed excellent minimum inhibitory concentration values of 10 μM against Staphylococcus aureus bacterial strain and were similar to ampicillin as an antibacterial reference. On the other hand, selected nicotinamidine derivatives were biologically screened for their cytotoxic activities against a panel of 60 cell lines representing nine types of human cancer at a single high dose at National Cancer Institute, Bethesda, MD, USA. Nicotinamidines showing promising activities were further assessed in a five-dose screening assay to determine their compound concentration causing 50% growth inhibition of tested cell (GI50), compound concentration causing 100% growth inhibition of tested cell (TGI), and compound concentration causing 50% lethality of tested cell (LC50) values. Structure-activity relationship studies demonstrated that the activity of members of this series can be modulated from cytostatic to cytotoxic based on the substitution pattern/nature on the terminal phenyl ring. The most active compound was found to be 4e displaying a submicromolar GI50 value of 0.83 μM, with TGI and LC50 values of 2.51 and 100 μM, respectively. Finally, the possible underlying mechanism of action of this series of

  2. Antimicrobial activity of Acanthus ilicifolius: Skin infection pathogens

    PubMed Central

    Govindasamy, Chinnavenkataraman; Arulpriya, Mani

    2013-01-01

    Objective To investigate the antimicrobial activity of Acanthus ilicifolius against the skin infecting bacterial and fungal pathogens. Through the literature survey, the mangrove plant Acanthus ilicifolius was used in skin infection diseases and have potential anti-inflammatory activity. Methods Antimicrobial activity of the leaf extracts was tested using agar well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were carried out. Results Among the different extracts, chloroform extract showed maximum activity against the bacterial pathogens methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Candida albicans and Trichophyton rubrum. Methanol and acetone extracts showed maximum activity against Staphylococcus epidermis and Lactobacillus plantarum respectively. Chloroform extracts showed the lowest MIC (0.5 mg/mL) and MBC (2 mg/mL) values against the skin pathogens compared with other extracts. Phytochemical screening revealed the presence of resins, steroids, tannins, glycosides, sugars, carbohydrates, saponins, sterols, terpenoids, phenol, alkaloids, cardiac glycosides and catechol. Conclusions Further, the separation of potential compounds from the crude extracts will be useful for control the skin infection pathogens.

  3. Absolute configuration and antimicrobial activity of acylhomoserine lactones.

    PubMed

    Pomini, Armando M; Marsaioli, Anita J

    2008-06-01

    (S)-N-Heptanoylhomoserine lactone is an uncommon acyl odd-chain natural product employed by many Gram-negative bacteria as a signaling substance in chemical communication mechanisms known as quorum sensing. The absolute configuration determination of the metabolite produced by the phytopathogen Pantoea ananatis Serrano is reported herein. As with all other substances of this class, the lactone moiety possesses S configuration, corroborating the hypothesis that it shares the same biosynthetic pathway as the (S)-N-hexanoylhomoserine lactone and also that some LuxI homologues can accept both hexanoyl- and heptanoyl-ACP as precursors. Evaluation of the antimicrobial activity of enantiomeric acylhomoserine lactones against three Gram-positive bacteria (Bacillus cereus, B. subtilis, and Staphylococcus aureus) revealed important features between absolute configuration and antimicrobial activity. The N-heptanoylhomoserine lactone was considerably less active than the 3-oxo derivatives. Surprisingly, non-natural (R)-N-(3-oxo-octanoyl)homoserine lactone was as active as the S enantiomer against B. cereus, while the synthetic racemic product was less active than either enantiomer. PMID:18465897

  4. Antimicrobial activity of Willowherb (Epilobium angustifolium L.) leaves and flowers.

    PubMed

    Kosalec, Ivan; Kopjar, Nevenka; Kremer, Dario

    2013-08-01

    Since the aetiology of benign prostatic hyperplasia (BHP) is still unknown, the use of medicinal herb extracts and products prepared thereof are recommended due to their antimicrobial activity, especially during early stages of BHP. A comparison was performed of the in vitro antimicrobial activity (using broth microdilution assay) of flowers and leaves of willowherb (Epilobium angustifolium L., Onagraceae) from Mt. Velebit (Croatia). The strains (standard ATCC and clinical isolates) of Staphylococcus aureus (including MRSA), Bacillus subtilis, Escherichia coli (including p-fimbriae positive strain), Pseudomonas aeruginosa, Proteus mirabilis, Candida albicans, C. tropicalis, C. dubliniensis and Saccharomyces cerevisiae were susceptible with MIC values between 4.6±0.2 and 18.2±0.8 mg/mL. The results of in vitro studies showed that no differences were found in the antimicrobial activity between the ethanol extracts of leaves and flowers of E. angustifolium. Using the quantitative fluorescent assay with ethidium bromide and acridine orange, the viability of C. albicans ATCC 10231 was assessed after in vitro exposure to E. angustifolium leaf and flower ethanol extracts. Apoptosis of C. albicans blastospores dominated over necrosis in all treated samples after short-term exposure with 6 to 12 mg/mL of extracts. In addition to the valuable biological activity of E. angustifolium extracts, the data obtained from the in vitro diffusion, the dilution assay and antifungal viability fluorescent assay suggest that leaf and flower ethanol extracts of E. angustifolium L. are a promising complementary herbal therapy of conditions such as BHP. PMID:23796429

  5. Mucin Binding Reduces Colistin Antimicrobial Activity

    PubMed Central

    Huang, Johnny X.; Blaskovich, Mark A. T.; Pelingon, Ruby; Ramu, Soumya; Kavanagh, Angela; Elliott, Alysha G.; Butler, Mark S.

    2015-01-01

    Colistin has found increasing use in treating drug-resistant bacterial lung infections, but potential interactions with pulmonary biomolecules have not been investigated. We postulated that colistin, like aminoglycoside antibiotics, may bind to secretory mucin in sputum or epithelial mucin that lines airways, reducing free drug levels. To test this hypothesis, we measured binding of colistin and other antibiotics to porcine mucin, a family of densely glycosylated proteins used as a surrogate for human sputum and airway mucin. Antibiotics were incubated in dialysis tubing with or without mucin, and concentrations of unbound antibiotics able to penetrate the dialysis tubing were measured over time using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The percentage of antibiotic measured in the dialysate after 4 h in the presence of mucin, relative to the amount without mucin, was 15% for colistin, 16% for polymyxin B, 19% for tobramycin, 52% for ciprofloxacin, and 78% for daptomycin. Antibiotics with the strongest mucin binding had an overall polybasic positive charge, whereas those with comparatively little binding were less basic. When comparing MICs measured with or without added mucin, colistin and polymyxin B showed >100-fold increases in MICs for multiple Gram-negative bacteria. Preclinical evaluation of mucin binding should become a standard procedure when considering the potential pulmonary use of new or existing antibiotics, particularly those with a polybasic overall charge. In the airways, mucin binding may reduce the antibacterial efficacy of inhaled or intravenously administered colistin, and the presence of sub-MIC effective antibiotic concentrations could result in the development of antibiotic resistance. PMID:26169405

  6. Evaluation of three medicinal plants for anti-microbial activity.

    PubMed

    Pratap, Gowd M J S; Manoj, Kumar M G; Sai, Shankar A J; Sujatha, B; Sreedevi, E

    2012-07-01

    Herbal remedies have a long history of use for gum and tooth problems such as dental caries. The present microbiological study was carried out to evaluate the antimicrobial efficacy of three medicinal plants (Terminalia chebula Retz., Clitoria ternatea Linn., and Wedelia chinensis (Osbeck.) Merr.) on three pathogenic microorganisms in the oral cavity (Streptococcus mutans, Lactobacillus casei, and Staphylococcus aureus). Aqueous extract concentrations (5%, 10%, 25%, and 50%) were prepared from the fruits of Terminalia chebula, flowers of Clitoria ternatea, and leaves of Wedelia chinensis. The antimicrobial efficacy of the aqueous extract concentrations of each plant was tested using agar well diffusion method and the size of the inhibition zone was measured in millimeters. The results obtained showed that the diameter of zone of inhibition increased with increase in concentration of extract and the antimicrobial efficacy of the aqueous extracts of the three plants was observed in the increasing order - Wedelia chinensis < Clitoria ternatea < Terminalia chebula. It can be concluded that the tested extracts of all the three plants were effective against dental caries causing bacteria. PMID:23723653

  7. Preparation, characterization and in vitro antimicrobial activity of liposomal ceftazidime and cefepime against Pseudomonas aeruginosa strains

    PubMed Central

    Torres, Ieda Maria Sapateiro; Bento, Etiene Barbosa; Almeida, Larissa da Cunha; de Sá, Luisa Zaiden Carvalho Martins; Lima, Eliana Martins

    2012-01-01

    Pseudomonas aeruginosa is an opportunistic microorganism with the ability to respond to a wide variety of environmental changes, exhibiting a high intrinsic resistance to a number of antimicrobial agents. This low susceptibility to antimicrobial substances is primarily due to the low permeability of its outer membrane, efflux mechanisms and the synthesis of enzymes that promote the degradation of these drugs. Cephalosporins, particularty ceftazidime and cefepime are effective against P. aeruginosa, however, its increasing resistance has limited the usage of these antibiotics. Encapsulating antimicrobial drugs into unilamellar liposomes is an approach that has been investigated in order to overcome microorganism resistance. In this study, antimicrobial activity of liposomal ceftazidime and cefepime against P. aeruginosa ATCC 27853 and P. aeruginosa SPM-1 was compared to that of the free drugs. Liposomal characterization included diameter, encapsulation efficiency and stability. Minimum Inhibitory Concentration (MIC) was determined for free and liposomal forms of both drugs. Minimum Bactericidal Concentration (MBC) was determined at concentrations 1, 2 and 4 times MIC. Average diameter of liposomes was 131.88 nm and encapsulation efficiency for cefepime and ceftazidime were 2.29% end 5.77%, respectively. Improved stability was obtained when liposome formulations were prepared with a 50% molar ratio for cholesterol in relation to the phospholipid. MIC for liposomal antibiotics for both drugs were 50% lower than that of the free drug, demonstrating that liposomal drug delivery systems may contribute to increase the antibacterial activity of these drugs. PMID:24031917

  8. In vitro antimicrobial activity of irreversible hydrocolloid impressions against 12 oral microorganisms.

    PubMed

    Casemiro, Luciana Assirati; Pires-de-Souza, Fernanda de Carvalho Panzeri; Panzeri, Heitor; Martins, Carlos Henrique Gomes; Ito, Isabel Yoko

    2007-01-01

    This study evaluated in vitro the antimicrobial activity of irreversible hydrocolloids (one containing an antimicrobial agent) prepared with water or with a 0.2% chlorhexidine digluconate solution against 12 strains of the oral microbiota. Twenty specimens (0.5x1.0 cm) for each group (1. Jeltrate mixed with water; 2. Jeltrate mixed with 0.2% chlorhexidine digluconate solution; 3. Greengel mixed with water; 4. Greengel mixed with 0.2% chlorhexidine digluconate solution) were prepared under sterile conditions and placed in culture media inoculated with the indicator strains. After incubation in aerobiosis or microaerophilia, inhibition of the microbial growth was measured and the results were interpreted. The normal adherence curve revealed a non-normal distribution of the data, so the non-parametric Friedman Test was performed (p<0.05). The antimicrobial activity of the groups was classified in the following order: 1, 3, 4, and 2. The results suggest that the method of preparing irreversible hydrocolloids with a 0.2% digluconate chlorhexidine solution is more effective than the incorporation of an antimicrobial agent in the powder to reduce cross-contamination caused by impressions. PMID:18060259

  9. Enhancing antibiofilm efficacy in antimicrobial photodynamic therapy: effect of microbubbles

    NASA Astrophysics Data System (ADS)

    Kishen, Anil; George, Saji

    2013-02-01

    In this study, we tested the hypothesis that a microbubble containing photosensitizer when activated with light would enable comprehensive disinfection of bacterial biofilms in infected root dentin by antimicrobial photodynamic therapy (APDT). Experiments were conducted in two stages. In the stage-1, microbubble containing photosensitizing formulation was tested for its photochemical properties. In the stage-2, the efficacy of microbubble containing photosensitizing formulation was tested on in vitro infected root canal model, developed with monospecies biofilm models of Enterococcus faecalis on root dentin substrate. The findings from this study showed that the microbubble containing photosensitizing formulation was overall the most effective formulation for photooxidation, generation of singlet oxygen, and in disinfecting the biofilm bacteria in the infected root canal model. This modified photosensitizing formulation will have potential advantages in eliminating bacterial biofilms from infected root dentin.

  10. Antimicrobial Activity of Xanthohumol and Its Selected Structural Analogues.

    PubMed

    Stompor, Monika; Żarowska, Barbara

    2016-01-01

    The objective of this study was to evaluate the antimicrobial activity of structural analogues of xanthohumol 1, a flavonoid compound found in hops (Humulus lupulus). The agar-diffusion method using filter paper disks was applied. Biological tests performed for selected strains of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, fungi (Alternaria sp.), and yeasts (Rhodotorula rubra, Candida albicans) revealed that compounds with at least one hydroxyl group-all of them have it at the C-4 position-demonstrated good activity. Our research showed that the strain S. aureus was more sensitive to chalcones than to the isomers in which the heterocyclic ring C is closed (flavanones). The strain R. rubra was moderately sensitive to only one compound: 4-hydroxy-4'-methoxychalcone 8. Loss of the hydroxyl group in the B-ring of 4'-methoxychalcones or its replacement by a halogen atom (-Cl, -Br), nitro group (-NO₂), ethoxy group (-OCH₂CH₃), or aliphatic substituent (-CH₃, -CH₂CH₃) resulted in the loss of antimicrobial activity towards both R. rubra yeast and S. aureus bacteria. Xanthohumol 1, naringenin 5, and chalconaringenin 7 inhibited growth of S. aureus, whereas 4-hydroxy-4'-methoxychalcone 8 was active towards two strains: S. aureus and R. rubra. PMID:27187329

  11. Prediction of Antibacterial Activity from Physicochemical Properties of Antimicrobial Peptides

    PubMed Central

    Melo, Manuel N.; Ferre, Rafael; Feliu, Lídia; Bardají, Eduard; Planas, Marta; Castanho, Miguel A. R. B.

    2011-01-01

    Consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. Studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible correlation of these with the in vivo onset of activity have only recently been proposed. In addition, such thresholds observed in model membranes occur at local peptide concentrations close to full membrane coverage. In this work we fully develop an interaction model of antimicrobial peptides with biological membranes; by exploring the consequences of the underlying partition formalism we arrive at a relationship that provides antibacterial activity prediction from two biophysical parameters: the affinity of the peptide to the membrane and the critical bound peptide to lipid ratio. A straightforward and robust method to implement this relationship, with potential application to high-throughput screening approaches, is presented and tested. In addition, disruptive thresholds in model membranes and the onset of antibacterial peptide activity are shown to occur over the same range of locally bound peptide concentrations (10 to 100 mM), which conciliates the two types of observations. PMID:22194847

  12. Influence of Surface Morphology on the Antimicrobial Effect of Transition Metal Oxides in Polymer Surface.

    PubMed

    Oh, Yoo Jin; Hubauer-Brenner, Michael; Hinterdorfer, Peter

    2015-10-01

    In this study, the physical properties of transition metal oxide surfaces were examined using scanning probe microscopic (SPM) techniques for elucidating the antimicrobial activity of molybdenum trioxide (MoO3), tungsten trioxide (WO3), and zinc oxide (ZnO) embedded into the polymers thermoplastic polyurethane (TPU) and polypropylene (PP). We utilized atomic force microscopy (AFM) in the contact imaging mode and its derivative single-pass Kelvin probe force microscopy for investigating samples that were presumably identical in their compositions, but showed different antimicrobial activity in bacterial adhesion tests. Our results revealed that surfaces with larger roughness and higher surface potential variation showed stronger antimicrobial activities compared to smoother and homogeneously charge-distributed surfaces. In addition, capacitance gradient (dC/dZ) measurements were performed to elucidate the antimicrobial activity arising from the different dielectric behavior of the transition metal oxides in this heterogeneous polymer surface. We found that the nano-scale exposure of transition metal oxides on polymer surfaces provided strong antimicrobial effects. Applications arising from our studies will be useful for public and healthcare environments. PMID:26726428

  13. Antioxidant and antimicrobial effects of garlic in chicken sausage

    PubMed Central

    Sallam, Kh.I.; Ishioroshi, M.; Samejima, K.

    2007-01-01

    The antioxidant and antimicrobial effects of equivalent concentrations of fresh garlic (FG), garlic powder (GP) and garlic oil (GO) were investigated against lipid oxidation and microbial growth in raw chicken sausage during storage at 3°C. The antioxidant activities were compared to that of a standard synthetic antioxidant; butylated hydroxyanisole (BHA). The initial mean levels of thiobarbituric acid (TBA) value and peroxide value (POV) were 0.140 and 6.32, respectively. However after 21 days of storage, TBA and POV ranged from 0.151 to 4.92, respectively, in FG (50 g/kg) formulated samples to 0.214 and 8.64, respectively, in GO (0.06 g/ kg) formulation. Addition of either garlic or BHA (0.1 g/kg) significantly delayed lipid oxidation when compared with control. The antioxidant activities of the various materials added followed the order FG>GP>BHA>GO. On the other hand, the initial aerobic plate count (APC) in the samples was 4.41 log10 CFU/g. Addition of FG (30 g/kg) or GP (9 g/kg) significantly reduced the APC and, subsequently, the shelf-life of the product was extended to 21 days. However, addition of GO or BHA resulted in no significant difference in APC when compared with control. Sensory analysis indicated that FG had a significant stronger flavor than the other sausage formulations. The results suggest that fresh garlic and garlic powder, through their combined antioxidant and antimicrobial effects, are potentially useful in preserving meat products. PMID:17330154

  14. Antimicrobial activity of chitosan coatings and films against Listeria monocytogenes on black radish.

    PubMed

    Jovanović, Gordana D; Klaus, Anita S; Nikšić, Miomir P

    2016-01-01

    The antibacterial activity of chitosan coatings prepared with acetic or lactic acid, as well as of composite chitosan-gelatin films prepared with essential oils, was evaluated in fresh shredded black radish samples inoculated with Listeria monocytogenes ATCC 19115 and L. monocytogenes ATCC 19112 during seven days of storage at 4°C. The chitosan coating prepared with acetic acid showed the most effective antibacterial activity. All tested formulations of chitosan films exhibited strong antimicrobial activity on the growth of L. monocytogenes on black radish, although a higher inhibition of pathogens was achieved at higher concentrations of chitosan. The antimicrobial effect of chitosan films was even more pronounced with the addition of essential oils. Chitosan-gelatin films with thyme essential oils showed the most effective antimicrobial activity. A reduction of 2.4log10CFU/g for L. monocytogenes ATCC 19115 and 2.1log10CFU/g for L. monocytogenes ATCC 19112 was achieved in the presence of 1% chitosan film containing 0.2% of thyme essential oil after 24h of storage. PMID:27237426

  15. Antimicrobial Activities of Three Medicinal Plants and Investigation of Flavonoids of Tripleurospermum disciforme

    PubMed Central

    Tofighi, Zahra; Molazem, Maryam; Doostdar, Behnaz; Taban, Parisa; Shahverdi, Ahmad Reza; Samadi, Nasrin; Yassa, Narguess

    2015-01-01

    Rosa damascena, Tripleurospermum disciforme and Securigera securidaca were used as disinfectant agents and for treatment of some disease in folk medicine of Iran. The antimicrobial effects of different fractions of seeds extract of S. securidaca, petals extract of R. damascena and aerial parts extract of T. disciforme were examined against some gram positive, gram negative and fungi by cup plate diffusion method. The petroleum ether and chloroform fractions of S. securidaca showed antibacterial activities against Staphylococcus aureus and Pseudomonas aeruginosa, while its methanol fraction had no antibacterial effects. R. damascena petals extract demonstrated antibacterial activities against Bacillus cereus, Staphylococcus epidermidis, S. aureus and Pseudomonas aeruginosa. T. disciforme aerial parts extract exhibited antimicrobial effects only against S. aureus and S. epidermidis. None of the fractions had any antifungal activities. Therefore, present study confirmed utility of these plants as disinfectant agents. Six flavonoids were isolated from T. disciforme: Luteolin, Quercetin-7-O-glucoside, Kaempferol, Kaempferol-7-O-glucoside, Apigenin and Apigenin-7-O-glucoside. The flavonoids and the antimicrobial activity of T. disciforme are reported for the first time. PMID:25561928

  16. Antimicrobial Activities of Three Medicinal Plants and Investigation of Flavonoids of Tripleurospermum disciforme.

    PubMed

    Tofighi, Zahra; Molazem, Maryam; Doostdar, Behnaz; Taban, Parisa; Shahverdi, Ahmad Reza; Samadi, Nasrin; Yassa, Narguess

    2015-01-01

    Rosa damascena, Tripleurospermum disciforme and Securigera securidaca were used as disinfectant agents and for treatment of some disease in folk medicine of Iran. The antimicrobial effects of different fractions of seeds extract of S. securidaca, petals extract of R. damascena and aerial parts extract of T. disciforme were examined against some gram positive, gram negative and fungi by cup plate diffusion method. The petroleum ether and chloroform fractions of S. securidaca showed antibacterial activities against Staphylococcus aureus and Pseudomonas aeruginosa, while its methanol fraction had no antibacterial effects. R. damascena petals extract demonstrated antibacterial activities against Bacillus cereus, Staphylococcus epidermidis, S. aureus and Pseudomonas aeruginosa. T. disciforme aerial parts extract exhibited antimicrobial effects only against S. aureus and S. epidermidis. None of the fractions had any antifungal activities. Therefore, present study confirmed utility of these plants as disinfectant agents. Six flavonoids were isolated from T. disciforme: Luteolin, Quercetin-7-O-glucoside, Kaempferol, Kaempferol-7-O-glucoside, Apigenin and Apigenin-7-O-glucoside. The flavonoids and the antimicrobial activity of T. disciforme are reported for the first time. PMID:25561928

  17. Characteristics and antimicrobial activity of copper-based materials

    NASA Astrophysics Data System (ADS)

    Li, Bowen

    In this study, copper vermiculite was synthesized, and the characteristics, antimicrobial effects, and chemical stability of copper vermiculite were investigated. Two types of copper vermiculite materials, micron-sized copper vermiculite (MCV) and exfoliated copper vermiculite (MECV), are selected for this research. Since most of the functional fillers used in industry products, such as plastics, paints, rubbers, papers, and textiles prefer micron-scaled particles, micron-sized copper vermiculite was prepared by jet-milling vermiculite. Meanwhile, since the exfoliated vermiculite has very unique properties, such as high porosity, specific surface area, high aspect ratio of laminates, and low density, and has been extensively utilized as a functional additives, exfoliated copper vermiculite also was synthesized and investigated. The antibacterial efficiency of copper vermiculite was qualitatively evaluated by the diffusion methods (both liquid diffusion and solid diffusion) against the most common pathogenic species: Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Klebsiella pneumoniae (K. pneumoniae). The result showed that the release velocity of copper from copper vermiculite is very slow. However, copper vermiculite clearly has excellent antibacterial efficiency to S. aureus, K. pneumoniae and E. coli. The strongest antibacterial ability of copper vermiculite is its action on S. aureus. The antibacterial efficiency of copper vermiculite was also quantitatively evaluated by determining the reduction rate (death rate) of E. coli versus various levels of copper vermiculite. 10 ppm of copper vermiculite in solution is sufficient to reduce the cell population of E. coli, while the untreated vermiculite had no antibacterial activity. The slow release of copper revealed that the antimicrobial effect of copper vermiculite was due to the strong interactions between copper ions and bacteria cells. Exfoliated copper vermiculite has even stronger

  18. Antimicrobial activity of different solvent extracted samples from the flowers of medicinally important Plumeria obstusa.

    PubMed

    Ali, Nasir; Ahmad, Dawood; Bakht, Jehan

    2015-01-01

    The present research work was carried out to investigate the antimicrobial (eight bacteria and one fungus) activities of different solvent (ethanol, petroleum ether, chloroform, ethyl acetate and isobutanol) extracted samples from flowers of P. obstusa by disc diffusion method. Analysis of the data revealed that all the five extracts from flowers of P. obstusa showed different ranges of antimicrobial activities. Petroleum ether fractions showed inhibitory activities against all the nine microbial species except Klebsiella pneumonia. Ethyl acetate and isobutanol fractions showed inhibitory effects against all the tested microbial species except Pseudomonas aeruginosa. Chloroform and ethanol extracts had varying levels of inhibitions against all of the tested microorganisms. The most susceptible gram positive bacterium was Bacillus subtilis which was inhibited by all the five extracts while the most resistant gram positive bacterium was Staphylococcus aureus. Erwinia carotovora was the most susceptible gram negative bacterium while Pseudomonas aeruginosa was highly resistant among the gram negative bacteria. PMID:25553696

  19. Phytochemical analysis and in vitro antimicrobial activity of two Satureja species essential oils.

    PubMed

    Skocibusić, Mirjana; Bezić, Nada

    2004-12-01

    The phytochemical GC[sol ]MS analysis and in vitro antimicrobial activity of the essential oils of the aerial parts of Satureja montana L. and Satureja cuneifolia Ten., collected in Croatia were performed. The major compound of S. montana oil was the phenolic monoterpene carvacrol (45.7%). Other important compounds were the monoterpenic hydrocarbons p-cymene (12.6%), gamma-terpinene (8.1%) and the oxygen-containing compounds carvacrol methyl ether, borneol, thymol and thymol methyl ether. The volatile oil of S. cuneifolia was characterized as beta-cubebene (8.7%), limonene (8.3%), alpha-pinene (6.9%), spathulenol and beta-caryophyllene. The antimicrobial effects of S. montana and S. cuneifolia oils were found to have a broad spectrum activity against multidrug-resistant pathogens by the broth microdilution method. These oils were active against all the test strains, with the exception of Pseudomonas aeruginosa. Compared with S. cuneifolia, savory oil exhibited greater antimicrobial activity. The maximum activity of savory oil was observed against Escherichia coli, methicillin-resistant Staphylococcus aureus and against the yeast (Candida albicans). The essential oil of S. cuneifolia was also found to inhibit the growth of medically important pathogens such as S. aureus and E. coli. Fungicidal activity for both oils against C. albicans and S. cerevisiae was also observed. PMID:15742345

  20. Synthesis of Cu/CNTs nanocomposites for antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Singhal, Sunil Kumar; Lal, Maneet; Lata; Ranjan Kabi, Soumya; Behari Mathur, Rakesh

    2012-12-01

    We report a facile method for the synthesis of Cu/multi-walled carbon nanotubes (CNTs) composite powder employing a chemical reduction method followed by high-energy ball milling involving the use of sodium borohydride as a reducing agent and copper sulphate as the precursor material. Control of oxidation of Cu nanoparticles (CuNPs) is a key factor in the synthesis of Cu/CNTs nanocomposites via chemical reduction methods and other methods. To overcome this problem we have applied a new facile rapid synthesis method using a combination of molecular-level mixing followed by high-energy ball milling to produce mostly CuNPs. X-ray diffraction results indicated the presence of mostly CuNPs in composite powder. Scanning electron microscopy and high resolution transmission electron microscopy (HRTEM) was used to ascertain the dispersion of CNTs in Cu matrix. Most of the CuNPs synthesized in the present work had a particle size ranging from 20–50 nm as revealed by HRTEM characterization. Moreover, the CNTs were also found to be homogeneously dispersed in Cu matrix. The Cu/CNTs nanocomposite has a wide range of applications from fuel cells to electronic chip components. In the present work we have investigated the antimicrobial activity of Cu powder and varying concentrations of Cu/CNTs nanocomposite against gram negative Providencia sp. bacteria, and gram positive Bacillus sp. bacteria. These findings suggest that Cu/CNTs nanocomposite can be used in antibacterial controlling systems and as an effective growth inhibitor in the case of various microorganisms.

  1. Antioxidant and antimicrobial activities of cinnamic acid derivatives.

    PubMed

    Sova, M

    2012-07-01

    Cinnamic acid is an organic acid occurring naturally in plants that has low toxicity and a broad spectrum of biological activities. In the search for novel pharmacologically active compounds, cinnamic acid derivatives are important and promising compounds with high potential for development into drugs. Many cinnamic acid derivatives, especially those with the phenolic hydroxyl group, are well-known antioxidants and are supposed to have several health benefits due to their strong free radical scavenging properties. It is also well known that cinnamic acid has antimicrobial activity. Cinnamic acid derivatives, both isolated from plant material and synthesized, have been reported to have antibacterial, antiviral and antifungal properties. Acids, esters, amides, hydrazides and related derivatives of cinnamic acid with such activities are here reviewed. PMID:22512578

  2. In vitro antimicrobial activity of Persian shallot (Allium hirtifolium).

    PubMed

    Soroush, Setareh; Taherikalani, Morovat; Asadollahi, Parisa; Asadollahi, Khairollah; Taran, Mojtaba; Emaneini, Mohammad; Alizadeh, Sajjad

    2012-01-01

    Allium hirtifolium is a Persian native plant grown in cool mountain slopes of Iran. It has been used as a spice in Iran for many years. According to the literature review, there are no considerable reports on the antimicrobial properties of this plant. In this study, the antimicrobial activity of Persian shallot hydroalcoholic extract and F1 fraction of the plant (containing amino acid derivatives and/or other cationic compounds) was investigated on some Gram positive cocci and bacilli, Gram negative bacilli, two protozoa, a yeast and a fungus. Excellent activity against Candida albicans (MIC = 64 microg/ml, MBC = 128 microg/ml), Leishmania infantum (MIC = 0.2 mg/ml on the first day of study) and Trichomonas vaginalis (MIC = 5 microg/ml in PSDE form) and a moderate activity against Bacillus spp and Pseudomonas aeroginosa (MIC = 128 microg/ml) was observed. The results showed that this plant contains some anti-trichomonas and anti-leishmania components. PMID:23210319

  3. Biosynthesis and Antimicrobial Activity of Semiconductor Nanoparticles against Oral Pathogens

    PubMed Central

    Malarkodi, C.; Rajeshkumar, S.; Paulkumar, K.; Vanaja, M.; Gnanajobitha, G.; Annadurai, G.

    2014-01-01

    Dental care is an essential phenomenon in human health. Oral pathogens can cause severe break which may show the way to serious issues in human disease like blood circulation and coronary disease. In the current study, we demonstrated the synthesis and antimicrobial activity of cadmium sulphide and zinc sulphide nanoparticles against oral pathogens. The process for the synthesis of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles is fast, novel, and ecofriendly. Formation of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles was confirmed by surface plasmon spectra using UV-Vis spectrophotometer. The morphology of crystalline phase of nanoparticles was determined from transmission electron microscopy (TEM) and X-ray diffraction (XRD) spectra. The average size of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles was in the range of 10 nm to 25 nm and 65 nm, respectively, and the observed morphology was spherical. The results indicated that the proteins, which contain amine groups, played a reducing and controlling responsibility during the formation of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles in the colloidal solution. The antimicrobial activity was assessed against oral pathogens such as Streptococcus sp. Staphylococcus sp. Lactobacillus sp., and Candida albicans and these results confirmed that the sulphide nanoparticles are exhibiting good bactericidal activity. PMID:24860280

  4. Antimicrobial Activity of Starch Hydrogel Incorporated with Copper Nanoparticles.

    PubMed

    Villanueva, María Emilia; Diez, Ana María Del Rosario; González, Joaquín Antonio; Pérez, Claudio Javier; Orrego, Manuel; Piehl, Lidia; Teves, Sergio; Copello, Guillermo Javier

    2016-06-29

    In order to obtain an antimicrobial gel, a starch-based hydrogel reinforced with silica-coated copper nanoparticles (Cu NPs) was developed. Cu NPs were synthesized by use of a copper salt and hydrazine as a reducing agent. In order to enhance Cu NP stability over time, they were synthesized in a starch medium followed by a silica coating. The starch hydrogel was prepared by use of urea and water as plasticizers and it was treated with different concentrations of silica-coated copper nanoparticles (Si-Cu NPs). The obtained materials were characterized by Fourier transform infrared (FT-IR) spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, scanning electron microscopy (SEM), and rheometry. FT-IR and EPR spectra were used for characterization of Cu NPs and Si-Cu NPs, confirming that a starch cap was formed around the Cu NP and demonstrating the stability of the copper nanoparticle after the silica coating step. SEM images showed Cu NP, Si-Cu NP, and hydrogel morphology. The particle size was polydisperse and the structure of the gels changed along with particle concentration. Increased NP content led to larger pores in starch structure. These results were in accordance with the rheological behavior, where reinforcement by the Si-Cu NP was seen. Antimicrobial activity was evaluated against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial species. The hydrogels were demonstrated to maintain antimicrobial activity for at least four cycles of use. A dermal acute toxicity test showed that the material could be scored as slightly irritant, proving its biocompatibility. With these advantages, it is believed that the designed Si-Cu NP loaded hydrogel may show high potential for applications in various clinical fields, such as wound dressings and fillers. PMID:27295333

  5. Determination of antimicrobial activity and resistance to oxidation of moringa peregrina seed oil.

    PubMed

    Lalas, Stavros; Gortzi, Olga; Athanasiadis, Vasilios; Tsaknis, John; Chinou, Ioanna

    2012-01-01

    The antimicrobial activity of the oil extracted with n-hexane from the seeds of Moringa peregrina was tested against Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Candida albicans, C. tropicalis and C. glabrata. The oil proved effective against all of the tested microorganisms. Standard antibiotics (netilmycin, 5-flucytocine, intraconazole and 7-amino-4-methylcoumarin-3-acetic acid) were used for comparison. The resistance to oxidation of the extracted seed oil was also determined. PMID:22367027

  6. Antimicrobial activity of essential oils from Mediterranean aromatic plants against several foodborne and spoilage bacteria.

    PubMed

    Silva, Nuno; Alves, Sofia; Gonçalves, Alexandre; Amaral, Joana S; Poeta, Patrícia

    2013-12-01

    The antimicrobial activity of essential oils extracted from a variety of aromatic plants, often used in the Portuguese gastronomy was studied in vitro by the agar diffusion method. The essential oils of thyme, oregano, rosemary, verbena, basil, peppermint, pennyroyal and mint were tested against Gram-positive (Listeria monocytogenes, Clostridium perfringens, Bacillus cereus, Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, and Staphylococcus epidermidis) and Gram-negative strains (Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa). For most essential oils examined, S. aureus, was the most susceptible bacteria, while P. aeruginosa showed, in general, least susceptibility. Among the eight essential oils evaluated, thyme, oregano and pennyroyal oils showed the greatest antimicrobial activity, followed by rosemary, peppermint and verbena, while basil and mint showed the weakest antimicrobial activity. Most of the essential oils considered in this study exhibited a significant inhibitory effect. Thyme oil showed a promising inhibitory activity even at low concentration, thus revealing its potential as a natural preservative in food products against several causal agents of foodborne diseases and food spoilage. In general, the results demonstrate that, besides flavoring the food, the use of aromatic herbs in gastronomy can also contribute to a bacteriostatic effect against pathogens. PMID:23444311

  7. Pharmacological assessment of the medicinal potential of Acacia mearnsii De Wild.: antimicrobial and toxicity activities.

    PubMed

    Olajuyigbe, Olufunmiso O; Afolayan, Anthony J

    2012-01-01

    Acacia mearnsii De Wild. (Fabaceae) is a medicinal plant used in the treatment of microbial infections in South Africa without scientific validation of its bioactivity and toxicity. The antimicrobial activity of the crude acetone extract was evaluated by both agar diffusion and macrobroth dilution methods while its cytotoxicity effect was assessed with brine shrimp lethality assay. The study showed that both bacterial and fungal isolates were highly inhibited by the crude extract. The MIC values for the gram-positive bacteria (78.1-312.5) μg/mL, gram-negative bacteria (39.1-625) μg/mL and fungal isolates (625-5000) μg/mL differ significantly. The bacteria were more susceptible than the fungal strains tested. The antibiosis determination showed that the extract was more (75%) bactericidal than bacteriostatic (25%) and more fungicidal (66.67%) than fungistatic (33.33%). The cytotoxic activity of the extract was observed between 31.25 μg/mL and 500 μg/mL and the LC(50) value (112.36 μg/mL) indicates that the extract was nontoxic in the brine shrimp lethality assay (LC(50) > 100 μg/mL). These results support the use of A. mearnsii in traditional medicine for treatment of microbial infections. The extract exhibiting significant broad spectrum antimicrobial activity and nontoxic effects has potential to yield active antimicrobial compounds. PMID:22605976

  8. Pharmacological Assessment of the Medicinal Potential of Acacia mearnsii De Wild.: Antimicrobial and Toxicity Activities

    PubMed Central

    Olajuyigbe, Olufunmiso O.; Afolayan, Anthony J.

    2012-01-01

    Acacia mearnsii De Wild. (Fabaceae) is a medicinal plant used in the treatment of microbial infections in South Africa without scientific validation of its bioactivity and toxicity. The antimicrobial activity of the crude acetone extract was evaluated by both agar diffusion and macrobroth dilution methods while its cytotoxicity effect was assessed with brine shrimp lethality assay. The study showed that both bacterial and fungal isolates were highly inhibited by the crude extract. The MIC values for the gram-positive bacteria (78.1–312.5) μg/mL, gram-negative bacteria (39.1–625) μg/mL and fungal isolates (625–5000) μg/mL differ significantly. The bacteria were more susceptible than the fungal strains tested. The antibiosis determination showed that the extract was more (75%) bactericidal than bacteriostatic (25%) and more fungicidal (66.67%) than fungistatic (33.33%). The cytotoxic activity of the extract was observed between 31.25 μg/mL and 500 μg/mL and the LC50 value (112.36 μg/mL) indicates that the extract was nontoxic in the brine shrimp lethality assay (LC50 > 100 μg/mL). These results support the use of A. mearnsii in traditional medicine for treatment of microbial infections. The extract exhibiting significant broad spectrum antimicrobial activity and nontoxic effects has potential to yield active antimicrobial compounds. PMID:22605976

  9. Neomycin Sulfate Improves the Antimicrobial Activity of Mupirocin-Based Antibacterial Ointments

    PubMed Central

    Blanchard, Catlyn; Brooks, Lauren; Beckley, Andrew; Colquhoun, Jennifer; Dewhurst, Stephen

    2015-01-01

    In the midst of the current antimicrobial pipeline void, alternative approaches are needed to reduce the incidence of infection and decrease reliance on last-resort antibiotics for the therapeutic intervention of bacterial pathogens. In that regard, mupirocin ointment-based decolonization and wound maintenance practices have proven effective in reducing Staphylococcus aureus transmission and mitigating invasive disease. However, the emergence of mupirocin-resistant strains has compromised the agent's efficacy, necessitating new strategies for the prevention of staphylococcal infections. Herein, we set out to improve the performance of mupirocin-based ointments. A screen of a Food and Drug Administration (FDA)-approved drug library revealed that the antibiotic neomycin sulfate potentiates the antimicrobial activity of mupirocin, whereas other library antibiotics did not. Preliminary mechanism of action studies indicate that neomycin's potentiating activity may be mediated by inhibition of the organism's RNase P function, an enzyme that is believed to participate in the tRNA processing pathway immediately upstream of the primary target of mupirocin. The improved antimicrobial activity of neomycin and mupirocin was maintained in ointment formulations and reduced S. aureus bacterial burden in murine models of nasal colonization and wound site infections. Combination therapy improved upon the effects of either agent alone and was effective in the treatment of contemporary methicillin-susceptible, methicillin-resistant, and high-level mupirocin-resistant S. aureus strains. From these perspectives, combination mupirocin-and-neomycin ointments appear to be superior to that of mupirocin alone and warrant further development. PMID:26596945

  10. Antimicrobial activity of Chinese medicine herbs against common bacteria in oral biofilm. A pilot study.

    PubMed

    Wong, R W K; Hägg, U; Samaranayake, L; Yuen, M K Z; Seneviratne, C J; Kao, R

    2010-06-01

    Twenty traditional Chinese medicines (TCM) were evaluated for their antimicrobial activity against four common oral bacteria. TCMs were tested for sensitivity against Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis. Aliquots of suspension of each bacterial species were inoculated onto a horse blood agar plate with TCMs soaked separately on 6mm paper disks. The plates were incubated for 48h anaerobically and the mean diameters of growth inhibition of three different areas obtained. 0.2% (w/v) chlorhexidine was used as a positive control. Broth microdilution assay was used to determine minimum inhibitory concentration and minimum bactericidal concentration. Fructus armeniaca mume was effective against all four bacteria. Thirteen TCMs demonstrated antimicrobial activity against Porphyromonas gingivalis, including Cortex magnoliae officinalis, Cortex phellodendri, Flos caryophylli, Flos lonicerae japonicae, Fructus armeniaca mume, Fructus forsythiae suspensae, Herba cum radice violae yedoensitis, Herba menthae haplocalycis, Pericarpium granati, Radix et rhizoma rhei, Radix gentianae, Ramulus cinnamomi cassia and Rhizoma cimicifugae. Cortex phellodendri showed antimicrobial activity against Streptococcus mutans, while Radix et rhizoma rhei was effective against Streptococcus mitis and Streptococcus sanguis. Fructus armeniaca mume had inhibitory effects against Streptococcus mitis, Streptococcus sanguis, Streptococcus mutans and Porphyromonas gingivalis in vitro. PMID:20418062

  11. Synthesis and Antimicrobial Activity of 1,2-Benzothiazine Derivatives.

    PubMed

    Patel, Chandani; Bassin, Jatinder P; Scott, Mark; Flye, Jenna; Hunter, Ann P; Martin, Lee; Goyal, Madhu

    2016-01-01

    A number of 1,2-benzothiazines have been synthesized in a three-step process. Nine chalcones 1-9 bearing methyl, fluoro, chloro and bromo substituents were chlorosulfonated with chlorosulfonic acid to generate the chalcone sulfonyl chlorides 10-18. These were converted to the dibromo compounds 19-27 through reaction with bromine in glacial acetic acid. Compounds 19-27 were reacted with ammonia, methylamine, ethylamine, aniline and benzylamine to generate a library of 45 1,2-benzothiazines 28-72. Compounds 28-72 were evaluated for their antimicrobial activity using broth microdilution techniques against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram-negative bacteria (Proteus vulgaris and Salmonella typhimurium). The results demonstrated that none of the compounds showed any activity against Gram-negative bacteria P. vulgaris and S. typhimurium; however, compounds 31, 33, 38, 43, 45, 50, 53, 55, 58, 60, 63 and 68 showed activity against Gram-positive bacteria Bacillus subtilis and Staphylococcous aureus. The range of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was 25-600 µg/mL, though some of the MIC and MBC concentrations were high, indicating weak activity. Structure activity relationship studies revealed that the compounds with a hydrogen atom or an ethyl group on the nitrogen of the thiazine ring exerted antibacterial activity against Gram-positive bacteria. The results also showed that the compounds where the benzene ring of the benzoyl moiety contained a methyl group or a chlorine or bromine atom in the para position showed higher antimicrobial activity. Similar influences were identified where either a bromine or chlorine atom was in the meta position. PMID:27376253

  12. Actin and DNA Protect Histones from Degradation by Bacterial Proteases but Inhibit Their Antimicrobial Activity

    PubMed Central

    Sol, Asaf; Skvirsky, Yaniv; Blotnick, Edna; Bachrach, Gilad; Muhlrad, Andras

    2016-01-01

    Histones are small polycationic proteins located in the cell nucleus. Together, DNA and histones are integral constituents of the nucleosomes. Upon apoptosis, necrosis, and infection – induced cell death, histones are released from the cell. The extracellular histones have strong antimicrobial activity but are also cytotoxic and thought as mediators of cell death in sepsis. The antimicrobial activity of the cationic extracellular histones is inhibited by the polyanionic DNA and F-actin, which also become extracellular upon cell death. DNA and F-actin protect histones from degradation by the proteases of Pseudomonas aeruginosa and Porphyromonas gingivalis. However, though the integrity of the histones is protected, the activity of histones as antibacterial agents is lost. The inhibition of the histone’s antibacterial activity and their protection from proteolysis by DNA and F-actin indicate a tight electrostatic interaction between the positively charged histones and negatively charged DNA and F-actin, which may have physiological significance in maintaining the equilibrium between the beneficial antimicrobial activity of extracellular histones and their cytotoxic effects. PMID:27555840

  13. Vibrational spectra and antimicrobial activity of selected bivalent cation benzoates

    NASA Astrophysics Data System (ADS)

    Borawska, M. H.; Koczoń, P.; Piekut, J.; Świsłocka, R.; Lewandowski, W.

    2009-02-01

    Selected bands of FT-IR spectra of Mg(II), Ca(II), Cu(II) and Zn(II) benzoates of both solid state and water solution, were assigned to appropriate molecular vibrations. Next evaluation of electronic charge distribution in both carboxylic anion and aromatic ring of studied compounds was performed. Classical plate tests and turbidimetry measurements, monitoring growth of bacteria Escherichia coli, Bacillus subtilis and yeasts Pichia anomala and Saccharomyces cerevisiae during 24 h of incubation, in optimal growth conditions (control) and in medium with addition of studied benzoate (concentration of 0.01% expressed as the concentration of benzoic acid), proved antimicrobial activity of studied compounds against investigated micro-organisms. PLS (partially least square) and PCR (principal component regression) techniques were applied to build a model, correlating spectral data reflecting molecular structure of studied compounds, with degree of influence of those compounds on growth of studied micro-organisms. Statistically significant correlation within cross validation diagnostic of PLS-1 calibration was found, when log 1/T of selected spectral regions of water solution samples were used as input data. The correlation coefficients between predicted with PLS calibration based on created 1, 2 or 3 factor models, and actual values of antimicrobial activity were: 0.70; 0.76, 0.81 for P. anomala, B. subtilis, and E. coli, respectively. Log(PRESS) values of appropriate models were 2.10, 2,39 and 3.23 for P. anomala, B. subtilis, and E. coli, respectively.

  14. Synthesis, characteristics and antimicrobial activity of ZnO nanoparticles.

    PubMed

    Janaki, A Chinnammal; Sailatha, E; Gunasekaran, S

    2015-06-01

    The utilization of various plant resources for the bio synthesis of metallic nano particles is called green technology and it does not utilize any harmful protocols. Present study focuses on the green synthesis of ZnO nano particles by Zinc Carbonate and utilizing the bio-components of powder extract of dry ginger rhizome (Zingiber officinale). The ZnO nano crystallites of average size range of 23-26 nm have been synthesized by rapid, simple and eco friendly method. Zinc oxide nano particles were characterized by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed the adsorption of surfactant molecules at the surface of ZnO nanoparticles and the presence of ZnO bonding. Antimicrobial activity of ZnO nano particles was done by well diffusion method against pathogenic organisms like Klebsiella pneumonia, Staphylococcus aureus and Candida albicans and Penicillium notatum. It is observed that the ZnO synthesized in the process has the efficient antimicrobial activity. PMID:25748589

  15. Synthesis, characteristics and antimicrobial activity of ZnO nanoparticles

    NASA Astrophysics Data System (ADS)

    Janaki, A. Chinnammal; Sailatha, E.; Gunasekaran, S.

    2015-06-01

    The utilization of various plant resources for the bio synthesis of metallic nano particles is called green technology and it does not utilize any harmful protocols. Present study focuses on the green synthesis of ZnO nano particles by Zinc Carbonate and utilizing the bio-components of powder extract of dry ginger rhizome (Zingiber officinale). The ZnO nano crystallites of average size range of 23-26 nm have been synthesized by rapid, simple and eco friendly method. Zinc oxide nano particles were characterized by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed the adsorption of surfactant molecules at the surface of ZnO nanoparticles and the presence of ZnO bonding. Antimicrobial activity of ZnO nano particles was done by well diffusion method against pathogenic organisms like Klebsiella pneumonia, Staphylococcus aureus and Candida albicans and Penicillium notatum. It is observed that the ZnO synthesized in the process has the efficient antimicrobial activity.

  16. Inhibitory Effects of Antimicrobial Peptides on Lipopolysaccharide-Induced Inflammation

    PubMed Central

    Sun, Yue; Shang, Dejing

    2015-01-01

    Antimicrobial peptides (AMPs) are usually small molecule peptides, which display broad-spectrum antimicrobial activity, high efficiency, and stability. For the multiple-antibiotic-resistant strains, AMPs play a significant role in the development of novel antibiotics because of their broad-spectrum antimicrobial activities and specific antimicrobial mechanism. Besides broad-spectrum antibacterial activity, AMPs also have anti-inflammatory activity. The neutralization of lipopolysaccharides (LPS) plays a key role in anti-inflammatory action of AMPs. On the one hand, AMPs can readily penetrate the cell wall barrier by neutralizing LPS to remove Gram-negative bacteria that can lead to infection. On the contrary, AMPs can also inhibit the production of biological inflammatory cytokines to reduce the inflammatory response through neutralizing circulating LPS. In addition, AMPs also modulate the host immune system by chemotaxis of leukocytes, to promote immune cell proliferation, epithelialization, and angiogenesis and thus play a protective role. This review summarizes some recent researches about anti-inflammatory AMPs, with a focus on the interaction of AMPs and LPS on the past decade. PMID:26612970

  17. Assessment of the in vitro antimicrobial activity of Lactobacillus species for identifying new potential antibiotics.

    PubMed

    Dubourg, Grégory; Elsawi, Ziena; Raoult, Didier

    2015-11-01

    The bacteriocin-mediated antimicrobial properties of Lactobacillus spp. have been widely studied, leading to the use of these micro-organisms in the food industry as preservative agents against foodborne pathogens. In an era in which antibiotic resistance is becoming a public health issue, the antimicrobial activity of Lactobacillus spp. could be used for the discovery of new potential antibiotics. Thus, it is essential to have an accurate method of screening the production of antimicrobial agents by prokaryotes. Many in vitro assays have been published to date, largely concerning but not limited to Lactobacillus spp. However, these methods mainly use the spot-on-the-lawn method, which is prone to contamination during the overlay stage, with protocols using methanol vapours or the reverse side agar technique being applied to avoid such contamination. In this study, a method combining the spot-on-the-lawn and well diffusion methods was tested, permitting clear identification of inhibition zones from eight Lactobacillus spp. towards clinical isolates of 12 species (11 bacteria and 1 yeast) commonly found in human pathology. Lactobacillus plantarum CIP 106786 and Lactobacillus rhamnosus CSUR P567 exhibited the widest antimicrobial activity, whereas Lactobacillus acidophilus strain DSM 20079 was relatively inactive. In addition, the putative MIC(50) of L. rhamnosus against Proteus mirabilis was estimated at 1.1×10(9)CFU/mL using culture broth dilution. In conclusion, considering the increasing cultivable bacterial human repertoire, these findings open the way of an effective method to screen in vitro for the production of potential antimicrobial compounds. PMID:26163158

  18. Comparative Antimicrobial Activities of Aerosolized Sodium Hypochlorite, Chlorine Dioxide, and Electrochemically Activated Solutions Evaluated Using a Novel Standardized Assay

    PubMed Central

    Thorn, R. M. S.; Robinson, G. M.

    2013-01-01

    The main aim of this study was to develop a standardized experimental assay to enable differential antimicrobial comparisons of test biocidal aerosols. This study represents the first chlorine-matched comparative assessment of the antimicrobial activities of aerosolized sodium hypochlorite, chlorine dioxide, and electrochemically activated solution (ECAS) to determine their relative abilities to decontaminate various surface-associated health care-relevant microbial challenges. Standard microbiological challenges were developed by surface-associating typed Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis spores, or a clinical methicillin-resistant S. aureus (MRSA) strain on stainless steel, polypropylene, or fabric. All test coupons were subjected to 20-min biocidal aerosols of chlorine-matched (100 ppm) sodium hypochlorite, chlorine dioxide, or ECAS within a standard aerosolization chamber using a commercial humidifier under defined conditions. Biocidal treatment type and material surface had a significant effect on the number of microorganisms recovered from various material surfaces following treatment exposure. Under the conditions of the assay, the order of antimicrobial efficacy of biocidal aerosol treatment was as follows: ECAS > chlorine dioxide > sodium hypochlorite. For all biocides, greater antimicrobial reductions were seen when treating stainless steel and fabric than when treating plastic-associated microorganisms. The experimental fogging system and assay protocol designed within this study were shown capable of differentiating the comparative efficacies of multiple chlorine-matched biocidal aerosols against a spectrum of target organisms on a range of test surface materials and would be appropriate for testing other biocidal aerosol treatments or material surfaces. PMID:23459480

  19. White Light-Activated Antimicrobial Paint using Crystal Violet.

    PubMed

    Hwang, Gi Byoung; Allan, Elaine; Parkin, Ivan P

    2016-06-22

    Crystal violet (CV) was incorporated into acrylic latex to produce white-light-activated antimicrobial paint (WLAAP). Measurement of the water contact angle of the WLAAP showed that the water contact angle increased with increasing CV concentration. In a leaching test over 120 h, the amount of CV that leached from the WLAAPs was close to the detection limit (<0.03%). The WLAAPs were used to coat samples of polyurethane, and these showed bactericidal activity against Escherichia coli, which is a key causative agent of healthcare-associated infections (HAIs). A reduction in the numbers of viable bacteria was observed on the painted coated polyurethane after 6 h in the dark, and the bactericidal activity increased with increasing CV concentration (P < 0.1). After 6 h of white light exposure, all of coated polyurethanes demonstrated a potent photobactericidal activity, and it was statistically confirmed that the WLAAP showed better activity in white light than in the dark (P < 0.05). At the highest CV concentration, the numbers of viable bacteria fell below the detection limit (<10(3) CFU/mL) after 6 h of white light exposure. The difference in antimicrobial activity between the materials in the light and dark was 0.48 log at CV 250 ppm, and it increased by 0.43 log at each increment of CV 250 ppm. The difference was the highest (>1.8 log) at the highest CV concentration (1000 ppm). These WLAAPs are promising candidates for use in healthcare facilities to reduce HAIs. PMID:26479680

  20. Antimicrobial activity of clove oil dispersed in a concentrated sugar solution.

    PubMed

    Briozzo, J; Núñez, L; Chirife, J; Herszage, L; D'Aquino, M

    1989-01-01

    Essential oil of clove, dispersed (0.4% v/v) in a concentrated sugar solution, had a marked germicidal effect against various bacteria and Candida albicans. Staphylococcus aureus (five strains), Klebsiella pneumoniae, Pseudomonas aeruginosa, Clostridium perfringens, and Escherichia coli inoculated at a level of 10(7) cfu/ml, and C. albicans (inoculum 4.0 x 10(5) cfu/ml) were killed (greater than 99.999%) after 2-7 min in a laboratory broth supplemented with 63% (v/w) of sugar, and containing 0.4% (v/w) of essential oil of clove. Added organic matter (i.e. human or bovine serum) did not impair its antimicrobial activity. Sugar was not necessary for the antimicrobial activity of clove oil, but the concentrated sugar solution provided a good vehicle for obtaining an oil dispersion that is relatively stable for certain practical applications. PMID:2542213

  1. Properties and limits of some essential oils: chemical characterisation, antimicrobial activity, interaction with antibiotics and cytotoxicity.

    PubMed

    Scazzocchio, Francesca; Garzoli, Stefania; Conti, Cinzia; Leone, Claudia; Renaioli, Clio; Pepi, Federico; Angiolella, Letizia

    2016-09-01

    Because of the emergence of multi-drug resistance bacteria and fungi, alternatives to conventional antimicrobial therapy are needed. This study aims to evaluate in vitro the antimicrobial activity of: Mirtus communis, Coriandrum sativum, Pelargonium capitatum, Cuminum cyminum, Ocimum basilicum, Citrus aurantium amara, Cymbopogon. winterianus, Cymbopogon martini, Salvia sclarea, Melaleuca alternifolia and Mentha suaveolens essential oils on bacteria and fungi, in relation to their chemical composition. The potential interaction of M. alternifolia (TTO), C. sativum (CDO) and M. suaveolens (EOMS) essential oils when used in combination with gentamicin and fluconazole has been evaluated. The results obtained showed a synergic effect on some bacteria and fungi, with FICI values ≤5. The cytotoxicity of TTO, CDO and EOMS was investigated towards HeLa cells. Only EOMS did not result cytotoxic at the active concentrations on micro-organisms. Further studies are necessary to obtain optimal ratios and dosing regimens for higher therapeutic efficacy and to decrease toxicological profiles. PMID:26395247

  2. Antimicrobial activity of selected synbiotics targeted for the elderly against pathogenic Escherichia coli strains.

    PubMed

    Likotrafiti, E; Tuohy, K M; Gibson, G R; Rastall, R A

    2016-01-01

    The aim of the present study was to evaluate the antimicrobial activity of two synbiotic combinations, Lactobacillus fermentum with short-chain fructooligosaccharides (FOS-LF) and Bifidobacterium longum with isomaltooligosaccharides (IMO-BL), against enterohaemorrhagic Escherichia coli O157:H7 and enteropathogenic E. coli O86. Antimicrobial activity was determined (1) by co-culturing the synbiotics and pathogens in batch cultures, and (2) with the three-stage continuous culture system (gut model), inoculated with faecal slurry from an elderly donor. In the co-culture experiments, IMO-BL was significantly inhibitory to both E. coli strains, while FOS-LF was slightly inhibitory or not inhibitory. Factors other than acid production appeared to play a role in the inhibition. In the gut models, both synbiotics effectively inhibited E. coli O157 in the first vessel, but not in vessels 2 and 3. E. coli O86 was not significantly inhibited. PMID:26754553

  3. Alternative Hand Contamination Technique To Compare the Activities of Antimicrobial and Nonantimicrobial Soaps under Different Test Conditions▿

    PubMed Central

    Fuls, Janice L.; Rodgers, Nancy D.; Fischler, George E.; Howard, Jeanne M.; Patel, Monica; Weidner, Patrick L.; Duran, Melani H.

    2008-01-01

    Antimicrobial hand soaps provide a greater bacterial reduction than nonantimicrobial soaps. However, the link between greater bacterial reduction and a reduction of disease has not been definitively demonstrated. Confounding factors, such as compliance, soap volume, and wash time, may all influence the outcomes of studies. The aim of this work was to examine the effects of wash time and soap volume on the relative activities and the subsequent transfer of bacteria to inanimate objects for antimicrobial and nonantimicrobial soaps. Increasing the wash time from 15 to 30 seconds increased reduction of Shigella flexneri from 2.90 to 3.33 log10 counts (P = 0.086) for the antimicrobial soap, while nonantimicrobial soap achieved reductions of 1.72 and 1.67 log10 counts (P > 0.6). Increasing soap volume increased bacterial reductions for both the antimicrobial and the nonantimicrobial soaps. When the soap volume was normalized based on weight (∼3 g), nonantimicrobial soap reduced Serratia marcescens by 1.08 log10 counts, compared to the 3.83-log10 reduction caused by the antimicrobial soap (P < 0.001). The transfer of Escherichia coli to plastic balls following a 15-second hand wash with antimicrobial soap resulted in a bacterial recovery of 2.49 log10 counts, compared to the 4.22-log10 (P < 0.001) bacterial recovery on balls handled by hands washed with nonantimicrobial soap. This indicates that nonantimicrobial soap was less active and that the effectiveness of antimicrobial soaps can be improved with longer wash time and greater soap volume. The transfer of bacteria to objects was significantly reduced due to greater reduction in bacteria following the use of antimicrobial soap. PMID:18441107

  4. Alternative hand contamination technique to compare the activities of antimicrobial and nonantimicrobial soaps under different test conditions.

    PubMed

    Fuls, Janice L; Rodgers, Nancy D; Fischler, George E; Howard, Jeanne M; Patel, Monica; Weidner, Patrick L; Duran, Melani H

    2008-06-01

    Antimicrobial hand soaps provide a greater bacterial reduction than nonantimicrobial soaps. However, the link between greater bacterial reduction and a reduction of disease has not been definitively demonstrated. Confounding factors, such as compliance, soap volume, and wash time, may all influence the outcomes of studies. The aim of this work was to examine the effects of wash time and soap volume on the relative activities and the subsequent transfer of bacteria to inanimate objects for antimicrobial and nonantimicrobial soaps. Increasing the wash time from 15 to 30 seconds increased reduction of Shigella flexneri from 2.90 to 3.33 log(10) counts (P = 0.086) for the antimicrobial soap, while nonantimicrobial soap achieved reductions of 1.72 and 1.67 log(10) counts (P > 0.6). Increasing soap volume increased bacterial reductions for both the antimicrobial and the nonantimicrobial soaps. When the soap volume was normalized based on weight (approximately 3 g), nonantimicrobial soap reduced Serratia marcescens by 1.08 log(10) counts, compared to the 3.83-log(10) reduction caused by the antimicrobial soap (P < 0.001). The transfer of Escherichia coli to plastic balls following a 15-second hand wash with antimicrobial soap resulted in a bacterial recovery of 2.49 log(10) counts, compared to the 4.22-log(10) (P < 0.001) bacterial recovery on balls handled by hands washed with nonantimicrobial soap. This indicates that nonantimicrobial soap was less active and that the effectiveness of antimicrobial soaps can be improved with longer wash time and greater soap volume. The transfer of bacteria to objects was significantly reduced due to greater reduction in bacteria following the use of antimicrobial soap. PMID:18441107

  5. Antiradical, antimicrobial and cytotoxic activities of commercial beetroot pomace.

    PubMed

    Vulić, Jelena J; Cebović, Tatjana N; Canadanović, Vladimir M; Cetković, Gordana S; Djilas, Sonja M; Canadanović-Brunet, Jasna M; Velićanski, Aleksandra S; Cvetković, Dragoljub D; Tumbas, Vesna T

    2013-04-30

    The by-product of food processing is often utilized as feed, and for the preparation of dietary fiber and biofuel. However, these products are also promising sources of bioactive antioxidants and color giving compounds, which could be used as additives in the food, pharmaceutical and cosmetic industry. The aim of this study was to investigate the phytochemical profile, and the antiradical, antimicrobial and cytotoxic activities of industrial beetroot pomace extract (BPE). The content of phenolics (45.68 mg gallic acid equivalents g(-1)), flavonoids (25.89 mg rutin equivalents g(-1)) and betalains (4.09 mg betanin g(-1); 7.32 mg vulgaxanthin I g(-1)) were determined spectrophotometrically. The antiradical activity on DPPH (EC(50)(DPPH·) = 0.0797 mg ml(-1)), hydroxyl (EC(50)(·OH) = 0.0655 mg ml(-1)) and superoxide anion (EC(50)(O2·-) = 1.0625 mg ml(-1)) radicals were measured by electron spin resonance (ESR) spectroscopy. The antimicrobial activity was determined using the agar-well diffusion method. Gram(-) bacteria (Salmonella typhimurium, Citrobacter freundii) and Gram(+) bacteria, (Staphylococcus aureus, Staphylococcus sciuri, Bacillus cereus) showed high susceptibility, while yeasts and moulds were resistant. BPE exhibits cytotoxic properties against Ehrlich carcinoma (EAC) cells in vivo due to induction of oxidative stress. The largest decreases in EAC cell numbers were observed in the pre-treated male (approximately 53%) and female (approximately 47%) mice, and also the EAC cell viability was decreased after administration of BPE. The activities of the antioxidant enzymes, xanthine oxidase (XOD) and peroxidase (Px), were significantly different between the untreated EAC control group and all other groups that were treated with BPE. The XOD and Px activities were very low in untreated malignant cells, but increased significantly after administration of BPE. Our results show that BPE holds promise in the food industry as a source of bioactive compounds. PMID

  6. In vivo antimicrobial activity of marbofloxacin against Pasteurella multocida in a tissue cage model in calves.

    PubMed

    Cao, Changfu; Qu, Ying; Sun, Meizhen; Qiu, Zhenzhen; Huang, Xianhui; Huai, Binbin; Lu, Yan; Zeng, Zhenling

    2015-01-01

    Marbofloxacin is a fluoroquinolone specially developed for use in veterinary medicine with broad-spectrum antibacterial activity. The objective of our study was to re-evaluate in vivo antimicrobial activity of marbofloxacin against Pasteurella multocida using subcutaneously implanted tissue cages in calves. Calves were infected by direct injection into tissue cages with P. multocida(type B, serotype 2), then intramuscularly received a range of marbofloxacin doses 24 h after inoculation. The ratio of 24 h area under the concentration-time curve divided by the minimum inhibitory concentration or the mutant prevention concentration (AUC24 h/MIC or AUC24 h/MPC) was the pharmacokinetic-pharmacodynamic (PK/PD) index that best described the effectiveness of marbofloxacin against P. multocida (R (2) = 0.8514) by non-linear regression analysis. Marbofloxacin exhibited a good antimicrobial activity in vivo. The levels of AUC24 h/MIC and AUC24 h/MPC that produced 50% (1.5log10 CFU/mL reduction) and 90% (3log10 CFU/mL reduction) of maximum response were 18.60 and 50.65 h, 4.67 and 12.89 h by using sigmoid Emax model WINNONLIN software, respectively. The in vivo PK/PD integrated methods by tissue cage model display the advantage of the evaluation of antimicrobial activity and the optimization of the dosage regimen for antibiotics in the presence of the host defenses, especially in target animal of veterinary interest. PMID:26257726

  7. In vivo antimicrobial activity of marbofloxacin against Pasteurella multocida in a tissue cage model in calves

    PubMed Central

    Cao, Changfu; Qu, Ying; Sun, Meizhen; Qiu, Zhenzhen; Huang, Xianhui; Huai, Binbin; Lu, Yan; Zeng, Zhenling

    2015-01-01

    Marbofloxacin is a fluoroquinolone specially developed for use in veterinary medicine with broad-spectrum antibacterial activity. The objective of our study was to re-evaluate in vivo antimicrobial activity of marbofloxacin against Pasteurella multocida using subcutaneously implanted tissue cages in calves. Calves were infected by direct injection into tissue cages with P. multocida(type B, serotype 2), then intramuscularly received a range of marbofloxacin doses 24 h after inoculation. The ratio of 24 h area under the concentration-time curve divided by the minimum inhibitory concentration or the mutant prevention concentration (AUC24 h/MIC or AUC24 h/MPC) was the pharmacokinetic-pharmacodynamic (PK/PD) index that best described the effectiveness of marbofloxacin against P. multocida (R2 = 0.8514) by non-linear regression analysis. Marbofloxacin exhibited a good antimicrobial activity in vivo. The levels of AUC24 h/MIC and AUC24 h/MPC that produced 50% (1.5log10 CFU/mL reduction) and 90% (3log10 CFU/mL reduction) of maximum response were 18.60 and 50.65 h, 4.67 and 12.89 h by using sigmoid Emax model WINNONLIN software, respectively. The in vivo PK/PD integrated methods by tissue cage model display the advantage of the evaluation of antimicrobial activity and the optimization of the dosage regimen for antibiotics in the presence of the host defenses, especially in target animal of veterinary interest. PMID:26257726

  8. Antimicrobial activity and composition profile of grape (Vitis vinifera) pomace extracts obtained by supercritical fluids.

    PubMed

    Oliveira, Daniela A; Salvador, Ana Augusta; Smânia, Artur; Smânia, Elza F A; Maraschin, Marcelo; Ferreira, Sandra R S

    2013-04-10

    The possibility of increasing the aggregated value of the huge amount of residues generated by wineries around the world foment studies using the grape pomace - the residue from the wine production, composed by seed, skin and stems - to obtain functional ingredients. Nowadays, consumers in general prefer natural and safe products mainly for food and cosmetic fields, where the supercritical fluid extraction is of great importance due to the purity of the extracts provided. Therefore, the objective of this work is to evaluate the global extraction yield, the antimicrobial activity and the composition profile of Merlot and Syrah grape pomace extracts obtained by supercritical CO2 (SC-CO2) and CO2 added with co-solvent at pressures up to 300 bar and temperatures of 50 and 60 °C. The results were compared with the ones obtained by Soxhlet and by ultrasound-assisted leaching extraction methods. The main components from the extracts, identified by HPLC, were gallic acid, p-OH-benzoic acid, vanillic acid and epicatechin. The antibacterial and antifungal activities of the extracts were evaluated using four strains of bacteria (Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa) and three fungi strains (Candida albicans, Candida parapsilosis, Candida krusei). Despite lower extraction yield results, the supercritical fluid extracts presented the highest antimicrobial effectiveness compared to the other grape pomace extracts due to the presence of antimicrobial active compounds. Syrah extracts were less efficient against the microorganisms tested and Merlot extracts were more active against Gram-positive bacteria. PMID:23036924

  9. Chemical Compositions and Antimicrobial Activities of Ocimum sanctum L. Essential Oils at Different Harvest Stages

    PubMed Central

    Saharkhiz, Mohammad Jamal; Kamyab, Amir Alam; Kazerani, Narges Khatoon; Zomorodian, Kamiar; Pakshir, Keyvan; Rahimi, Mohammad Javad

    2014-01-01

    Background: Essential Oils (EOs) possess antibacterial properties and represent a natural source to treat infections and prevent food spoilage. Their chemical composition might be affected by the environmental condition and the developmental growth stages of the plant. Objectives: The current study aimed to determine the variations in chemical compositions and antimicrobial activities of the EOs of Ocimum sanctum L. at different stages of harvesting. Materials and Methods: The oils constituents were analyzed by gas chromatography/mass spectrometry (GC/MS). The effects of three different harvest stages of O. sanctum EOs against most common causes of food-borne were evaluated by broth micro-dilution method as recommended by the Clinical and Laboratory Standards Institute (CLSI). Results: The analysis of the EOs indicated that eugenol was the major compound of the EOs at all developmental stages which reached its maximum level at the second stage. The results showed that the tested EOs exhibited antimicrobial activities against all of the examined pathogens at concentrations of 0.125-32 µL/mL, except Pseudomonas aeruginosa which was only inhibited by high concentrations of the floral budding and full flowering EOs. EO distilled from the second developmental growth stage (floral budding) of O. sanctum exhibited the strongest antibacterial activities against the food borne bacteria. Conclusions: Considering the wide range of antimicrobial activities of the examined EOs, they might have the potential to be used to manage infectious diseases or extend the shelf life of food products. PMID:25763132

  10. Evaluation of the Antimicrobial Effect of Chitosan/Polyvinyl Alcohol Electrospun Nanofibers Containing Mafenide Acetate

    PubMed Central

    Abbaspour, Mohammadreza; Sharif Makhmalzadeh, Behzad; Rezaee, Behjat; Shoja, Saeed; Ahangari, Zohreh

    2015-01-01

    Background: Chitosan, an important biodegradable and biocompatible polymer, has demonstrated wound-healing and antimicrobial properties. Objectives: This study aimed to evaluate the antimicrobial properties of mafenide acetate-loaded nanofibrous films, prepared by the electrospinning technique, using chitosan and polyvinyl alcohol (PVA). Materials and Methods: A 32 full factorial design was used for formulating electrospinning solutions. The chitosan percentage in chitosan/PVA solutions (0%, 10%, and 30%) and the drug content (0%, 20%, and 40%) were chosen as independent variables. The release rate of mafenide acetate from nanofibrous films and their microbial penetration were evaluated. The antimicrobial activity of different nanofibrous film formulations against Staphylococcus aureus and Pseudomonas aeruginosa was studied. Results: The results indicated that all nanofibrous films, with and without drug, can prevent bacterial penetration. Incorporation of mafenide acetate into chitosan/PVA nanofibers enhanced their antimicrobial activity against P. aeruginosa and S. aureus. Conclusions: Overall, the results showed that chitosan/polyvinyl alcohol (PVA) nanofibrous films are applicable for use as a wound dressing with protective, healing, and antimicrobial effects. PMID:26587214

  11. Antimicrobial activity of different filling pastes for deciduous tooth treatment.

    PubMed

    Antoniazzi, Bruna Feltrin; Pires, Carine Weber; Bresolin, Carmela Rampazzo; Weiss, Rita Niederauer; Praetzel, Juliana Rodrigues

    2015-01-01

    Guedes-Pinto paste is the filling material most employed in Brazil for endodontic treatment of deciduous teeth; however, the Rifocort® ointment has been removed. Thus, the aim of this study was to investigate the antimicrobial potential of filling pastes, by proposing three new pharmacological associations to replace Rifocort® ointment with drugs of already established antimicrobial power: Nebacetin® ointment, 2% Chlorhexidine Gluconate gel, and Maxitrol® ointment. A paste composed of Iodoform, Rifocort® ointment and Camphorated Paramonochlorophenol (CPC) was employed as the gold standard (G1). The other associations were: Iodoform, Nebacetin® ointment and CPC (G2); Iodoform, 2% Chlorhexidine Digluconate gel and CPC (G3); Iodoform, Maxitrol® ointment and CPC (G4). The associations were tested for Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus oralis (S. oralis), Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), and Bacillus subtilis (B. subtilis), using the methods of dilution on solid medium - orifice agar - and broth dilution. The results were tested using statistical analysis ANOVA and Kruskal-Wallis. They showed that all the pastes had a bacteriostatic effect on all the microorganisms, without any statistically significant difference, compared with G1. S. aureus was statistically significant (multiple comparison test of Tukey), insofar as G2 and G3 presented the worst and the best performance, respectively. All associations were bactericidal for E. coli, S. aureus, S. mutans and S. oralis. Only G3 and G4 were bactericidal for E. faecalis, whereas no product was bactericidal for B. subtilis. Thus, the tested pastes have antimicrobial potential and have proved acceptable for endodontic treatment of primary teeth. PMID:25466327

  12. Green Synthesis and Characterization of Silver Nanoparticles for Antimicrobial Activity Against Burn Wounds Contaminating Bacteria

    NASA Astrophysics Data System (ADS)

    Rout, Anandini; Jena, Padan K.; Sahoo, Debasish; Parida, Umesh K.; Bindhani, Birendra K.

    2014-04-01

    Silver nanoparticles (AgNPs) were prepared from the plant extract of N. arbor-tristis under atmospheric conditions through green synthesis and characterized by various physicochemical techniques like UV-Visible spectroscopy, IR Spectra, energy dispersive X-ray spectrometry (EDS), X-ray diffraction and transmission electron microscopy (TEM) and the results confirmed the synthesis of homogeneous and stable AgNPs by the plant extracts. The antimicrobial activity of AgNPs was investigated against most common bacteria found in burn wound Staphylococcus epidermidis and Pseudomonas aeruginosa. In these tests, Mueller Hinton agar plates were used with AgNPs of various concentrations, supplemented in liquid systems. P. aeruginosa was inhibited at the low concentration of AgNPs, whereas the growth-inhibitory effect on S. epidermidis was mild. These results suggest that AgNPs can be used as effective growth inhibitors of various microorganisms, making them applicable to diverse medical devices and antimicrobial control systems.

  13. Antimicrobial activity of extracts from Tamarindus indica L. leaves.

    PubMed

    Escalona-Arranz, Julio César; Péres-Roses, Renato; Urdaneta-Laffita, Imilci; Camacho-Pozo, Miladis Isabel; Rodríguez-Amado, Jesús; Licea-Jiménez, Irina

    2010-07-01

    Tamarindus indica L. leaves are reported worldwide as antibacterial and antifungal agents; however, this observation is not completely accurate in the case of Cuba. In this article, decoctions from fresh and sun dried leaves, as well as fluid extracts prepared with 30 and 70% ethanol-water and the pure essential oil from tamarind leaves were microbiologically tested against Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomona aeruginosa and Candida albicans. Aqueous and fluid extracts were previously characterized by spectrophotometric determination of their total phenols and flavonoids, while the essential oil was chemically evaluated by gas chromatography/mass spectroscopy (GC/MS). Experimental data suggest phenols as active compounds against B. subtilis cultures, but not against other microorganisms. On the other hand, the essential oil exhibited a good antimicrobial spectrum when pure, but its relative low concentrations in common folk preparations do not allow for any good activity in these extracts. PMID:20931087

  14. Synthesis and antimicrobial activity of monodisperse copper nanoparticles.

    PubMed

    Kruk, Tomasz; Szczepanowicz, Krzysztof; Stefańska, Joanna; Socha, Robert P; Warszyński, Piotr

    2015-04-01

    Metallic monodisperse copper nanoparticles at a relatively high concentration (300 ppm CuNPs) have been synthesized by the reduction of copper salt with hydrazine in the aqueous SDS solution. The average particles size and the distribution size were characterized by Dynamic Light Scattering (DLS), Nanosight-Nanoparticle Tracking Analysis (NTA). The morphology and structure of nanoparticles were investigated using Scanning Electron Microscopy (SEM). The chemical composition of the copper nanoparticles was determined by X-ray Photoelectron Spectroscopy (XPS). Monodisperse copper nanoparticles with average diameter 50 nm were received. UV/vis absorption spectra confirmed the formation of the nanoparticles with the characteristic peak 550 nm. The antimicrobial studies showed that the copper nanoparticles had high activity against Gram-positive bacteria, standard and clinical strains, including methicillin-resistant Staphylococcus aureus, comparable to silver nanoparticles and some antibiotics. They also exhibited antifungal activity against Candida species. PMID:25723345

  15. Antimicrobial activity of extracts from Tamarindus indica L. leaves

    PubMed Central

    Escalona-Arranz, Julio César; Péres-Roses, Renato; Urdaneta-Laffita, Imilci; Camacho-Pozo, Miladis Isabel; Rodríguez-Amado, Jesús; Licea-Jiménez, Irina

    2010-01-01

    Tamarindus indica L. leaves are reported worldwide as antibacterial and antifungal agents; however, this observation is not completely accurate in the case of Cuba. In this article, decoctions from fresh and sun dried leaves, as well as fluid extracts prepared with 30 and 70% ethanol-water and the pure essential oil from tamarind leaves were microbiologically tested against Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomona aeruginosa and Candida albicans. Aqueous and fluid extracts were previously characterized by spectrophotometric determination of their total phenols and flavonoids, while the essential oil was chemically evaluated by gas chromatography/mass spectroscopy (GC/MS). Experimental data suggest phenols as active compounds against B. subtilis cultures, but not against other microorganisms. On the other hand, the essential oil exhibited a good antimicrobial spectrum when pure, but its relative low concentrations in common folk preparations do not allow for any good activity in these extracts. PMID:20931087

  16. In vitro antimicrobial activity of peroxide-based bleaching agents.

    PubMed

    Napimoga, Marcelo Henrique; de Oliveira, Rogério; Reis, André Figueiredo; Gonçalves, Reginaldo Bruno; Giannini, Marcelo

    2007-06-01

    Antibacterial activity of 4 commercial bleaching agents (Day White, Colgate Platinum, Whiteness 10% and 16%) on 6 oral pathogens (Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis, Candida albicans, Lactobacillus casei, and Lactobacillus acidophilus) and Staphylococcus aureus were evaluated. A chlorhexidine solution was used as a positive control, while distilled water was the negative control. Bleaching agents and control materials were inserted in sterilized stainless-steel cylinders that were positioned under inoculated agar plate (n = 4). After incubation according to the appropriate period of time for each microorganism, the inhibition zones were measured. Data were analyzed by 2-way analysis of variance and Tukey test (a = 0.05). All bleaching agents and the chlorhexidine solution produced antibacterial inhibition zones. Antimicrobial activity was dependent on peroxide-based bleaching agents. For most microorganisms evaluated, bleaching agents produced inhibition zones similar to or larger than that observed for chlorhexidine. C albicans, L casei, and L acidophilus were the most resistant microorganisms. PMID:17625621

  17. Antimicrobial activity of diterpenes from Viguiera arenaria against endodontic bacteria.

    PubMed

    Carvalho, Tatiane C; Simão, Marília R; Ambrósio, Sérgio R; Furtado, Niege A J C; Veneziani, Rodrigo C S; Heleno, Vladimir C G; Da Costa, Fernando B; Gomes, Brenda P F A; Souza, Maria Gorete M; Borges dos Reis, Erika; Martins, Carlos H G

    2011-01-01

    Six pimarane-type diterpenes isolated from Viguiera arenaria Baker and two semi-synthetic derivatives were evaluated in vitro against a panel of representative microorganisms responsible for dental root canal infections. The microdilution method was used for the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Porphyromonas gingivalis, Prevotella nigrescens, Prevotella intermedia, Prevotella buccae, Fusobacterium nucleatum, Bacteroides fragilis, Actinomyces naeslundii, Actinomyces viscosus, Peptostreptococcus micros, Enterococcus faecalis and Aggregatibacter actinomycetemcomitans. The compounds ent-pimara-8(14),15-dien-19-oic acid, its sodium salt and ent-8(14),15-pimaradien-3β-ol were the most active, displaying MIC values ranging from 1 to 10 μg mL-1. The results also allow us to conclude that minor structural differences among these diterpenes significantly influence their antimicrobial activity, bringing new perspectives to the discovery of new chemicals for use as a complement to instrumental endodontic procedures. PMID:21233793

  18. Antioxidant, Antimicrobial Activity and Medicinal Properties of Grewia asiatica L.

    PubMed

    Shukla, Ritu; Sharma, Dinesh C; Baig, Mohammad H; Bano, Shabana; Roy, Sudeep; Provazník, Ivo; Kamal, Mohammad A

    2016-01-01

    Since ancient time, India is a well known subcontinent for medicinal plants where diversity of plants is known for the treatment of many human disorders. Grewia asiatica is a dicot shrub belonging to the Grewioideae family and well known for its medicinally important fruit commonly called Falsa. G. asiatica, a seasonal summer plant is distributed in the forest of central India, south India, also available in northern plains and western Himalaya up to the height of 3000 ft. Fruits of G. asiatica are traditionally used as a cooling agent, refreshing drink, anti-inflammatory agent and for the treatment of some urological disorders. Recent advancement of Falsa researches concluded its antimicrobial and anti-diabetic activity. Since ancient time medicinal plants are traditionally used for the treatment of different diseases G. asiatica fruit is the edible and tasty part of the plant, now considered as a valuable source of unique natural product for the development of medicines which are used in different disease conditions like anti-diabetic, anti-inflammatory, anti-cancerous and antimicrobial. Now a days, G. asiatica is being used in different Ayurvedic formulation for the cure of different types of diseases. Different pharmacological investigations reveal the presence of phenols, saponnins, flavonoids and tannins compound in the fruits. Present review highlights the phytopharmacological and different traditional use of G. asiatica which is mentioned in ancient Ayurvedic texts. This review stimulates the researchers and scientists for further research on G. asiatica. PMID:26516779

  19. IL-27 suppresses antimicrobial activity in human leprosy

    PubMed Central

    Teles, Rosane M. B.; Kelly-Scumpia, Kindra M.; Sarno, Euzenir N.; Rea, Thomas H.; Ochoa, Maria T.; Cheng, Genhong; Modlin, Robert L.

    2015-01-01

    The mechanisms by which intracellular pathogens trigger immunosuppressive pathways are critical for understanding the pathogenesis of microbial infection. One pathway that inhibits host defense responses involves the induction of type I interferons and subsequently IL-10, yet the mechanism by which type I IFN induces IL-10 remains unclear. Our studies of gene expression profiles derived from leprosy skin lesions suggested a link between IL-27 and the IFN-β induced IL-10 pathway. Here, we demonstrate that the IL-27p28 subunit is upregulated following treatment of monocytes with IFN-β and Mycobacterium leprae, the intracellular bacterium that causes leprosy. The ability of IFN-β and M. leprae to induce IL-10 was diminished by IL-27 knockdown. Additionally, treatment of monocytes with recombinant IL-27 was sufficient to induce the production of IL-10. Functionally, IL-27 inhibited the ability of IFN-γ to trigger antimicrobial activity against M. leprae in infected monocytes. At the site of disease, IL-27 was more strongly expressed in skin lesions of patients with progressive lepromatous leprosy, correlating and colocalizing with IFN-β and IL-10 in macrophages. Together, these data provide evidence that in the human cutaneous immune responses to microbial infection, IL-27 contributes to the suppression of host antimicrobial responses. PMID:26030183

  20. IL-27 Suppresses Antimicrobial Activity in Human Leprosy.

    PubMed

    Teles, Rosane M B; Kelly-Scumpia, Kindra M; Sarno, Euzenir N; Rea, Thomas H; Ochoa, Maria T; Cheng, Genhong; Modlin, Robert L

    2015-10-01

    The mechanisms by which intracellular pathogens trigger immunosuppressive pathways are critical for understanding the pathogenesis of microbial infection. One pathway that inhibits host defense responses involves the induction of type I interferons and subsequently IL-10, yet the mechanism by which type I IFN induces IL-10 remains unclear. Our studies of gene expression profiles derived from leprosy skin lesions suggested a link between IL-27 and the IFN-β induced IL-10 pathway. Here, we demonstrate that the IL-27p28 subunit is upregulated following treatment of monocytes with IFN-β and Mycobacterium leprae, the intracellular bacterium that causes leprosy. The ability of IFN-β and M. leprae to induce IL-10 was diminished by IL-27 knockdown. Additionally, treatment of monocytes with recombinant IL-27 was sufficient to induce the production of IL-10. Functionally, IL-27 inhibited the ability of IFN-γ to trigger antimicrobial activity against M. leprae in infected monocytes. At the site of disease, IL-27 was more strongly expressed in skin lesions of patients with progressive lepromatous leprosy, correlating and colocalizing with IFN-β and IL-10 in macrophages. Together, these data provide evidence that in the human cutaneous immune responses to microbial infection, IL-27 contributes to the suppression of host antimicrobial responses. PMID:26030183

  1. Antimicrobial Activity of Terminalia catappa, Manilkara zapota and Piper betel Leaf Extract

    PubMed Central

    Nair, R.; Chanda, Sumitra

    2008-01-01

    Aqueous and methanol extract of the leaves of Terminalia catappa L., Manilkara zapota L. and Piper betel L. were evaluated for antibacterial activity against 10 Gram positive, 12 Gram negative bacteria and one fungal strain, Candida tropicalis. Piperacillin and gentamicin were used as standards for antibacterial assay, while fluconazole was used as standard for antifungal assay. The three plants showed different degree of activity against the microorganisms investigated. The methanolic extract was considerably more effective than aqueous extract in inhibiting the investigated microbial strains. The most active antimicrobial plant was Piper betel. PMID:20046756

  2. Antimicrobial Activity of Terminalia catappa, Manilkara zapota and Piper betel Leaf Extract.

    PubMed

    Nair, R; Chanda, Sumitra

    2008-01-01

    Aqueous and methanol extract of the leaves of Terminalia catappa L., Manilkara zapota L. and Piper betel L. were evaluated for antibacterial activity against 10 Gram positive, 12 Gram negative bacteria and one fungal strain, Candida tropicalis. Piperacillin and gentamicin were used as standards for antibacterial assay, while fluconazole was used as standard for antifungal assay. The three plants showed different degree of activity against the microorganisms investigated. The methanolic extract was considerably more effective than aqueous extract in inhibiting the investigated microbial strains. The most active antimicrobial plant was Piper betel. PMID:20046756

  3. Antimicrobial and antioxidant activities of Cortex Magnoliae Officinalis and some other medicinal plants commonly used in South-East Asia

    PubMed Central

    Chan, Lai Wah; Cheah, Emily LC; Saw, Constance LL; Weng, Wanyu; Heng, Paul WS

    2008-01-01

    Background Eight medicinal plants were tested for their antimicrobial and antioxidant activities. Different extraction methods were also tested for their effects on the bioactivities of the medicinal plants. Methods Eight plants, namely Herba Polygonis Hydropiperis (Laliaocao), Folium Murraya Koenigii (Jialiye), Rhizoma Arachis Hypogea (Huashenggen), Herba Houttuyniae (Yuxingcao), Epipremnum pinnatum (Pashulong), Rhizoma Typhonium Flagelliforme (Laoshuyu), Cortex Magnoliae Officinalis (Houpo) and Rhizoma Imperatae (Baimaogen) were investigated for their potential antimicrobial and antioxidant properties. Results Extracts of Cortex Magnoliae Officinalis had the strongest activities against M. Smegmatis, C. albicans, B. subtilis and S. aureus. Boiled extracts of Cortex Magnoliae Officinalis, Folium Murraya Koenigii, Herba Polygonis Hydropiperis and Herba Houttuyniae demonstrated greater antioxidant activities than other tested medicinal plants. Conclusion Among the eight tested medicinal plants, Cortex Magnoliae Officinalis showed the highest antimicrobial and antioxidant activities. Different methods of extraction yield different spectra of bioactivities. PMID:19038060

  4. Phytochemical screening and antimicrobial activities of the constituents isolated from Koelreuteria paniculata leaves.

    PubMed

    Ghahari, Somayeh; Alinezhad, Heshmatollah; Nematzadeh, Ghorban Ali; Ghahari, Sajjad

    2015-01-01

    Methanolic extract of Golden rain leaves was fractionated by column chromatography on silica gel and 18 fractions were obtained. Antimicrobial activities of fractions were investigated against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa as quality control bacteria and fungus Pyricularia grisea which causes Blast disease in rice. Fractions showed more antibacterial activity at 0.04 g/mL concentration only on B. subtilis and S. aureus as gram positive bacteria. Also, three fractions indicated excellent antifungal effect on fungus P. grisea. Moreover, in the present study, fractions that showed very good effect on microorganisms were used for gas chromatography-mass spectrometry analysis to identify different phytochemicals. PMID:25813082

  5. Contribution of Amphipathicity and Hydrophobicity to the Antimicrobial Activity and Cytotoxicity of β-Hairpin Peptides

    PubMed Central

    2016-01-01

    Bacteria have acquired extensive resistance mechanisms to protect themselves against antibiotic action. Today the bacterial membrane has become one of the “final frontiers” in the search for new compounds acting on novel targets to address the threat of multi-drug resistant (MDR) and XDR bacterial pathogens. β-Hairpin antimicrobial peptides are amphipathic, membrane-binding antibiotics that exhibit a broad range of activities against Gram-positive, Gram-negative, and fungal pathogens. However, most members of the class also possess adverse cytotoxicity and hemolytic activity that preclude their development as candidate antimicrobials. We examined peptide hydrophobicity, amphipathicity, and structure to better dissect and understand the correlation between antimicrobial activity and toxicity, membrane binding, and membrane permeability. The hydrophobicity, pI, net charge at physiological pH, and amphipathic moment for the β-hairpin antimicrobial peptides tachyplesin-1, polyphemusin-1, protegrin-1, gomesin, arenicin-3, and thanatin were determined and correlated with key antimicrobial activity and toxicity data. These included antimicrobial activity against five key bacterial pathogens and two fungi, cytotoxicity against human cell lines, and hemolytic activity in human erythrocytes. Observed antimicrobial activity trends correlated with compound amphipathicity and, to a lesser extent, with overall hydrophobicity. Antimicrobial activity increased with amphipathicity, but unfortunately so did toxicity. Of note, tachyplesin-1 was found to be 8-fold more amphipathic than gomesin. These analyses identify tachyplesin-1 as a promising scaffold for rational design and synthetic optimization toward an antibiotic candidate. PMID:27331141

  6. Protocols to test the activity of antimicrobial peptides against the honey bee pathogen Paenibacillus larvae.

    PubMed

    Khilnani, Jasmin C; Wing, Helen J

    2015-10-01

    Paenibacillus larvae is the causal agent of the honey bee disease American Foulbrood. Two enhanced protocols that allow the activity of antimicrobial peptides to be tested against P. larvae are presented. Proof of principle experiments demonstrate that the honey bee antimicrobial peptide defensin 1 is active in both assays. PMID:26210039

  7. Antimicrobial activity and cellular toxicity of nanoparticle-polymyxin B conjugates

    NASA Astrophysics Data System (ADS)

    Park, Soonhyang; Chibli, Hicham; Wong, Jody; Nadeau, Jay L.

    2011-05-01

    We investigate the antimicrobial activity and cytotoxicity to mammalian cells of conjugates of the peptide antibiotic polymyxin B (PMB) to Au nanoparticles and CdTe quantum dots. Au nanoparticles fully covered with PMB are identical in antimicrobial activity to the free drug alone, whereas partially-conjugated Au particles show decreased effectiveness in proportion to the concentration of Au. CdTe-PMB conjugates are more toxic to Escherichia coli than PMB alone, resulting in a flattening of the steep PMB dose-response curve. The effect is most pronounced at low concentrations of PMB, with a greater effect on the concentration required to reduce growth by half (IC50) than on the concentration needed to inhibit all growth (minimum inhibitory concentration, MIC). The Gram positive organism Staphylococcus aureus is resistant to both PMB and CdTe, showing minimal increased sensitivity when the two are conjugated. Measurement of reactive oxygen species (ROS) generation shows a significant reduction in photo-generated hydroxyl and superoxide radicals with CdTe-PMB as compared with bare CdTe. There is a corresponding reduction in toxicity of QD-PMB versus bare CdTe to mammalian cells, with nearly 100% survival in fibroblasts exposed to bactericidal concentrations of QD-PMB. The situation in bacteria is more complex: photoexcitation of the CdTe particles plays a small role in IC50 but has a significant effect on the MIC, suggesting that at least two different mechanisms are responsible for the antimicrobial action seen. These results show that it is possible to create antimicrobial agents using concentrations of CdTe quantum dots that do not harm mammalian cells.

  8. Effect of dietary antimicrobials on immune status in broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present experiment was conducted to evaluate the effect of dietary antimicrobials (anticoccidials plus antibiotic growth promoters) on the development of post-hatch immune systems in commercial broiler chickens. One hundred and five day-old broiler chicks were raised on the used litter and provi...

  9. Broad Spectrum Antimicrobial Activity of Forest-Derived Soil Actinomycete, Nocardia sp. PB-52

    PubMed Central

    Sharma, Priyanka; Kalita, Mohan C.; Thakur, Debajit

    2016-01-01

    A mesophilic actinomycete strain designated as PB-52 was isolated from soil samples of Pobitora Wildlife Sanctuary of Assam, India. Based on phenotypic and molecular characteristics, the strain was identified as Nocardia sp. which shares 99.7% sequence similarity with Nocardia niigatensis IFM 0330 (NR_112195). The strain is a Gram-positive filamentous bacterium with rugose spore surface which exhibited a wide range of antimicrobial activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), Gram-negative bacteria, and yeasts. Optimization for the growth and antimicrobial activity of the strain PB-52 was carried out in batch culture under shaking condition. The optimum growth and antimicrobial potential of the strain were recorded in GLM medium at 28°C, initial pH 7.4 of the medium and incubation period of 8 days. Based on polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS) gene-targeted PCR amplification, the occurrence of both of these biosynthetic pathways was detected which might be involved in the production of antimicrobial compounds in PB-52. Extract of the fermented broth culture of PB-52 was prepared with organic solvent extraction method using ethyl acetate. The ethyl acetate extract of PB-52 (EA-PB-52) showed lowest minimum inhibitory concentration (MIC) against S. aureus MTCC 96 (0.975 μg/mL) whereas highest was recorded against Klebsiella pneumoniae ATCC 13883 (62.5 μg/mL). Scanning electron microscopy (SEM) revealed that treatment of the test microorganisms with EA-PB-52 destroyed the targeted cells with prominent loss of cell shape and integrity. In order to determine the constituents responsible for its antimicrobial activity, EA-PB-52 was subjected to chemical analysis using gas chromatography-mass spectrometry (GC-MS). GC-MS analysis showed the presence of twelve different chemical constituents in the extract, some of which are reported to possess diverse biological activity. These

  10. Antimicrobial activities of natural antimicrobial compounds against susceptible and antibiotic-resistant pathogens in the absence and presence of food

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to improve microbial food safety, we are studying the antimicrobial activities of different classes of natural compounds including plant essential oils, apple, grape, olive, and tea extracts, bioactive components, and seashell-derived chitosans against multiple foodborne pathogens in cu...

  11. General principles of antimicrobial therapy.

    PubMed

    Leekha, Surbhi; Terrell, Christine L; Edson, Randall S

    2011-02-01

    Antimicrobial agents are some of the most widely, and often injudiciously, used therapeutic drugs worldwide. Important considerations when prescribing antimicrobial therapy include obtaining an accurate diagnosis of infection; understanding the difference between empiric and definitive therapy; identifying opportunities to switch to narrow-spectrum, cost-effective oral agents for the shortest duration necessary; understanding drug characteristics that are peculiar to antimicrobial agents (such as pharmacodynamics and efficacy at the site of infection); accounting for host characteristics that influence antimicrobial activity; and in turn, recognizing the adverse effects of antimicrobial agents on the host. It is also important to understand the importance of antimicrobial stewardship, to know when to consult infectious disease specialists for guidance, and to be able to identify situations when antimicrobial therapy is not needed. By following these general principles, all practicing physicians should be able to use antimicrobial agents in a responsible manner that benefits both the individual patient and the community. PMID:21282489

  12. Antimicrobial activity of clove and cinnamon essential oils against Listeria monocytogenes in pasteurized milk.

    PubMed

    Cava, R; Nowak, E; Taboada, A; Marin-Iniesta, F

    2007-12-01

    The antimicrobial activity of essential oils (EOs) of cinnamon bark, cinnamon leaf, and clove against Listeria monocytogenes Scott A were studied in semiskimmed milk incubated at 7 degrees C for 14 days and at 35 degrees C for 24 h. The MIC was 500 ppm for cinnamon bark EO and 3,000 ppm for the cinnamon leaf and clove EOs. These effective concentrations increased to 1,000 ppm for cinnamon bark EO, 3,500 ppm for clove EO, and 4,000 ppm for cinnamon leaf EO when the semiskimmed milk was incubated at 35 degrees C for 24 h. Partial inhibitory concentrations and partial bactericidal concentrations were obtained for all the assayed EOs. The MBC was 3,000 ppm for the cinnamon bark EO, 10,500 ppm for clove EO, and 11,000 ppm for cinnamon leaf EO. The incubation temperature did not affect the MBC of the EOs but slightly increased the MIC at 35 degrees C. The increased activity at the lower temperature could be attributed to the increased membrane fluidity and to the membrane-perturbing action of EOs. The influence of the fat content of milk on the antimicrobial activity of EOs was tested in whole and skimmed milk. In milk samples with higher fat content, the antimicrobial activity of the EOs was reduced. These results indicate the possibility of using these three EOs in milk beverages as natural antimicrobials, especially because milk beverages flavored with cinnamon and clove are consumed worldwide and have been increasing in popularity in recent years. PMID:18095427

  13. Exploring of Antimicrobial Activity of Triphala Mashi—an Ayurvedic Formulation

    PubMed Central

    Jagatap, Sheetal; Khandelwal, K. R.; Singhania, Smita S.

    2008-01-01

    Triphala Mashi is an ayurvedic formulation that was prepared in our lab. Aqueous and alcoholic extracts of both Triphala and Triphala Mashi were used, to evaluate antimicrobial activity. Comparative phytochemical profile of Triphala and Triphala Mashi was done by preliminary phytochemical screening, total phenolic content and thin layer chromatography (TLC). Antimicrobial activity includes isolation of pathogens from clinical samples, its characterization, testing its multiple drug resistance against standard antibiotics and antimicrobial activity of aqueous and alcoholic extracts of both Triphala and Triphala Mashi against these organisms by using agar gel diffusion method. Triphala Mashi containing phenolic compounds, tannins exhibited comparable antimicrobial activity in relation to Triphala against all the microorganisms tested. It inhibits the dose-dependent growth of Gram-positive and Gram-negative bacteria. In conclusion, it appears that Triphala Mashi has non-specific antimicrobial activity. PMID:18317557

  14. In vitro antimicrobial activity of phytotherapic Uncaria tomentosa against endodontic pathogens.

    PubMed

    Herrera, Daniel R; Tay, Lidia Y; Rezende, Eluise C; Kozlowski, Vitoldo A; Santos, Elizabete B dos

    2010-09-01

    The aim of this study was to evaluate the antimicrobial activity of Uncaria tomentosa (Willd.) DC (cat's claw) against Enterococcus faecalis, Staphylococcus aureus, and Candida albicans. Suspensions with 10(8) cells/ml of each microorganism were plated in triplicate on Mueller-Hinton agar. Wells in the agar were made and filled with 2% chlorhexidine (CHX) gel, 2% cat's claw (CC) gel, 2% CHX+CC, and 1% hydroxyethylcellulose (NAT) gel. Inhibition halos were measured after 24 h at 37°C and differences were analyzed using one-way ANOVA. The mean diameter of the microbial growth inhibition zones of 2% CHX+CC against the tested microbial strains ranged from 21.7 to 33.5 mm. This was the most effective substance against E. faecalis and C. albicans, followed by CHX and CC. Against S. aureus, CHX+CC, CHX, and CC showed similar antimicrobial activity (P > 0.05). The results indicate that all the investigated compounds had antimicrobial activity against microorganisms frequently found in infected root-filled teeth. PMID:20881342

  15. Selection of enhanced antimicrobial activity posing lactic acid bacteria characterised by (GTG)5-PCR fingerprinting.

    PubMed

    Šalomskienė, Joana; Abraitienė, Asta; Jonkuvienė, Dovilė; Mačionienė, Irena; Repečkienė, Jūratė

    2015-07-01

    The aim of the study was a detail evaluation of genetic diversity among the lactic acid bacteria (LAB) strains having an advantage of a starter culture in order to select genotypically diverse strains with enhanced antimicrobial effect on some harmfull and pathogenic microorganisms. Antimicrobial activity of LAB was performed by the agar well diffusion method and was examined against the reference strains and foodborne isolates of Bacillus cereus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Antifungal activity was tested against the foodborne isolates of Candida parapsilosis, Debaromyces hansenii, Kluyveromyces marxianus, Pichia guilliermondii, Yarowia lipolytica, Aspergillus brasiliensis, Aspergillus versicolor, Cladosporium herbarum, Penicillium chrysogenum and Scopulariopsis brevicaulis. A total 40 LAB strains representing Lactobacillus (23 strains), Lactococcus (13 strains) and Streptococcus spp. (4 strains) were characterised by repetitive sequence based polymerase chain reaction fingerprinting which generated highly discriminatory profiles, confirmed the identity and revealed high genotypic heterogeneity among the strains. Many of tested LAB demonstrated strong antimicrobial activity specialised against one or few indicator strains. Twelve LAB strains were superior in suppressing growth of the whole complex of pathogenic bacteria and fungi. These results demonstrated that separate taxonomic units offered different possibilities of selection for novel LAB strains could be used as starter cultures enhancing food preservation. PMID:26139877

  16. Composition, antimicrobial activity and in vitro cytotoxicity of essential oil from Cinnamomum zeylanicum Blume (Lauraceae).

    PubMed

    Unlu, Mehmet; Ergene, Emel; Unlu, Gulhan Vardar; Zeytinoglu, Hulya Sivas; Vural, Nilufer

    2010-11-01

    The essential oil from the bark of Cinnamomum zeylanicum Blume was analyzed by GC-MS and bioassays were carried out. Nine constituents representing 99.24% of the oil were identified by GC-MS. The major compounds in the oil were (E)-cinnamaldehyde (68.95%), benzaldehyde (9.94%) and (E)-cinnamyl acetate (7.44%). The antimicrobial activity of the oil was investigated in order to evaluate its efficacy against 21 bacteria and 4 Candida species, using disc diffusion and minimum inhibitory concentration methods. The essential oil showed strong antimicrobial activity against all microorganisms tested. The cytotoxic and apoptotic effects of the essential oil on ras active (5RP7) and normal (F2408) fibroblasts were examined by MTT assay and acridine orange/ethidium bromide staining, respectively. The cytotoxicity of the oil was quite strong with IC(50) values less than 20 μg/mL for both cell lines. 5RP7 cells were affected stronger than normal cells. Morphological observation of apoptotic cells indicated the induction of apoptosis at the high level of the oil, especially in 5RP7 cells. The present study showed the potential antimicrobial and anticarcinogenic properties of the essential oil of cinnamon bark, indicating the possibilities of its potential use in the formula of natural remedies for the topical treatment of infections and neoplasms. PMID:20828600

  17. Electrochemically activated solutions: evidence for antimicrobial efficacy and applications in healthcare environments.

    PubMed

    Thorn, R M S; Lee, S W H; Robinson, G M; Greenman, J; Reynolds, D M

    2012-05-01

    Due to the limitations associated with the use of existing biocidal agents, there is a need to explore new methods of disinfection to help maintain effective bioburden control, especially within the healthcare environment. The transformation of low mineral salt solutions into an activated metastable state, by electrochemical unipolar action, produces a solution containing a variety of oxidants, including hypochlorous acid, free chlorine and free radicals, known to possess antimicrobial properties. Electrochemically activated solutions (ECAS) have been shown to have broad-spectrum antimicrobial activity, and have the potential to be widely adopted within the healthcare environment due to low-cost raw material requirements and ease of production (either remotely or in situ). Numerous studies have found ECAS to be highly efficacious, as both a novel environmental decontaminant and a topical treatment agent (with low accompanying toxicity), but they are still not in widespread use, particularly within the healthcare environment. This review provides an overview of the scientific evidence for the mode of action, antimicrobial spectrum and potential healthcare-related applications of ECAS, providing an insight into these novel yet seldom utilised biocides. PMID:21809085

  18. Comparative evaluation of the antimicrobial activity of 19 essential oils.

    PubMed

    Chaftar, Naouel; Girardot, Marion; Labanowski, Jérôme; Ghrairi, Tawfik; Hani, Khaled; Frère, Jacques; Imbert, Christine

    2016-01-01

    In our research on natural compounds efficient against human pathogen or opportunist microorganisms contracted by food or water, the antimicrobial activity of 19 essential oils (EOs) was investigated against 11 bacterial species (6 Gram positive, 5 Gram negative) and 7 fungal species (2 dermatophytes, 1 mould, 4 yeasts) using microdilution assays. Five essential oils were obtained from Tunisian plants (EOtun): Artemisia herba-alba Asso, Juniperus phoenicea L., Rosmarinus officinalis L., Ruta graveolens L. and Thymus vulgaris L., whereas others were commercial products (EOcom). Overall, T. vulgaris EOtun was the most efficient EO against both bacteria (Gram negative: MIC ≤ 0.34 mg/mL; Gram positive: MIC ≤ 0.70 mg/mL) and fungi (yeasts: MIC ≤ 0.55 mg/mL; mould: MIC = 0.30 mg/mL; dermatophytes: MIC ≤ 0.07 mg/mL). Two EOcom displayed both acceptable antibacterial and antifungal potency, although weaker than T. vulgaris EOtun activity: Origanum vulgare EOcom (bacteria: MIC ≤ 1.13 mg/mL, fungi: MIC ≤ 1.80 mg/mL), and Cymbopogon martinii var. motia EOcom (bacteria: MIC ≤ 1.00 mg/mL, fungi: MIC ≤ 0.80 mg/mL). Bacillus megaterium, Legionella pneumophila, Listeria monocytogenes and Trichophyton spp. were the most sensitive species to both EOcom and EOtun. This study demonstrated the noteworthy antimicrobial activity of two commercial EOs and points out the remarkable efficiency of T. vulgaris EOtun on all tested bacterial and fungal species, certainly associated with its high content in carvacrol (85 %). These three oils could thus represent promising candidates for applications in water and food protections. PMID:26566647

  19. Bile Acids Improve the Antimicrobial Effect of Rifaximin▿ †

    PubMed Central

    Darkoh, Charles; Lichtenberger, Lenard M.; Ajami, Nadim; Dial, Elizabeth J.; Jiang, Zhi-Dong; DuPont, Herbert L.

    2010-01-01

    Diarrhea is one of the most common infirmities affecting international travelers, occurring in 20 to 50% of persons from industrialized countries visiting developing regions. Enterotoxigenic Escherichia coli (ETEC) is the most common causative agent and is isolated from approximately half of the cases of traveler's diarrhea. Rifaximin, a largely water-insoluble, nonabsorbable (<0.4%) antibiotic that inhibits bacterial RNA synthesis, is approved for use for the treatment of traveler's diarrhea caused by diarrheagenic E. coli. However, the drug has minimal effect on the bacterial flora or the infecting E. coli strain in the aqueous environment of the colon. The purpose of the present study was to evaluate the antimicrobial effect and bioavailability of rifaximin in aqueous solution in the presence and absence of physiologic concentrations of bile acids. The methods used included growth measurement of ETEC (strain H10407), rifaximin solubility measurements, total bacterial protein determination, and assessment of the functional activity of rifaximin by monitoring inhibition of bacterial β-galactosidase expression. Solubility studies showed rifaximin to be 70- to 120-fold more soluble in bile acids (approximately 30% in 4 mM bile acids) than in aqueous solution. Addition of both purified bile acids and human bile to rifaximin at subinhibitory and inhibitory concentrations significantly improved the drug's anti-ETEC effect by 71% and 73%, respectively, after 4 h. This observation was confirmed by showing a decrease in the overall amount of total bacterial protein expressed during incubation of rifaximin plus bile acids. Rifaximin-treated samples containing bile acids inhibited the expression of ETEC β-galactosidase at a higher magnitude than samples that did not contain bile acids. The study provides data showing that bile acids solubilize rifaximin on a dose-response basis, increasing the drug's bioavailability and antimicrobial effect. These observations suggest

  20. Anti-inflammatory and antimicrobial activities of novel pyrazole analogues.

    PubMed

    Surendra Kumar, R; Arif, Ibrahim A; Ahamed, Anis; Idhayadhulla, Akbar

    2016-09-01

    A new sequence of pyrazole derivatives (1-6) was synthesized from condensation technique under utilizing ultrasound irradiation. Synthesized compounds were characterized from IR, (1)H NMR, (13)C NMR, Mass and elemental analysis. Synthesized compounds (1-6) were screened for antimicrobial activity. Among the compounds 3 (MIC: 0.25 μg/mL) was exceedingly antibacterially active against gram negative bacteria of Escherichia coli and compound 4 (MIC: 0.25 μg/mL) was highly active against gram positive bacteria of Streptococcus epidermidis compared with standard Ciprofloxacin. Compound 2 (MIC: 1 μg/mL) was highly antifungal active against Aspergillus niger proportionate to Clotrimazole. Synthesized compounds (1-6) were screened for anti-inflammatory activity and the compound 2-((5-hydroxy-3-methyl-1H-pyrazol-4-yl)(4-nitrophenyl)methyl)hydrazinecarboxamide (4) was better activity against anti-inflammatory when compared with standard drugs (Diclofenac sodium). Compounds (2, 3 and 4) are the most important molecules and hence the need to develop new drugs of antibacterial, antifungal and anti-inflammatory agents. PMID:27579011

  1. Olive Mill Waste Extracts: Polyphenols Content, Antioxidant, and Antimicrobial Activities

    PubMed Central

    Leouifoudi, Inass; Harnafi, Hicham; Zyad, Abdelmajid

    2015-01-01

    Natural polyphenols extracts have been usually associated with great bioactive properties. In this work, we investigated in vitro antioxidant and antimicrobial potential of the phenolic olive mill wastewater extracts (OWWE) and the olive cake extracts (OCE). Using the Folin Ciocalteux method, OWWE contained higher total phenol content compared to OCE (8.90 ± 0.728 g/L versus 0.95 ± 0.017 mg/g). The phenolic compounds identification was carried out with a performance liquid chromatograph coupled to tandem mass spectrometry equipment (HPLC-ESI-MS). With this method, a list of polyphenols from OWWE and OCE was obtained. The antioxidant activity was measured in aqueous (DPPH) and emulsion (BCBT) systems. Using the DPPH assay, the results show that OWWE was more active than OCE and interestingly the extracts originating from mountainous areas were more active than those produced from plain areas (EC50 = 12.1 ± 5.6 μg/mL; EC50 = 157.7 ± 34.9 μg/mL, resp.). However, when the antioxidant activity was reversed in the BCBT, OCE produced from plain area was more potent than mountainous OCE. Testing by the gel diffusion assay, all the tested extracts have showed significant spectrum antibacterial activity against Staphylococcus aureus, whereas the biophenols extracts showed more limited activity against Escherichia coli and Streptococcus faecalis. PMID:26693221

  2. The antimicrobial and antibiofilm activities of copper(II) complexes.

    PubMed

    Beeton, Michael L; Aldrich-Wright, Janice R; Bolhuis, Albert

    2014-11-01

    Biofilm-related bacterial infections pose a significant problem, as they are generally more tolerant to antibiotics and the immune system. Development of novel compounds with antibiofilm activity is therefore paramount. In this study we have analysed metal complexes of the general structure [M(IL)(AL)](2+) (where IL represents functionalised 1,10-phenanthrolines and AL represents 1S,2S- or 1R,2R-diaminocyclohexane) and [Cu(IL)3](2+). Antimicrobial activity was tested on a number of bacterial strains, showing that copper(II) compounds were active against both Gram-positive and Gram-negative bacteria, albeit that activity was generally higher for the former. The antibiofilm activity was then determined against a clinical isolate of meticillin-resistant Staphylococcus aureus (MRSA). Strikingly, the copper complexes tested showed significant activity against biofilms, and were better in the removal of biofilms than vancomycin, an antibiotic that is currently used in the treatment of MRSA infections. PMID:25124857

  3. Olive Mill Waste Extracts: Polyphenols Content, Antioxidant, and Antimicrobial Activities.

    PubMed

    Leouifoudi, Inass; Harnafi, Hicham; Zyad, Abdelmajid

    2015-01-01

    Natural polyphenols extracts have been usually associated with great bioactive properties. In this work, we investigated in vitro antioxidant and antimicrobial potential of the phenolic olive mill wastewater extracts (OWWE) and the olive cake extracts (OCE). Using the Folin Ciocalteux method, OWWE contained higher total phenol content compared to OCE (8.90 ± 0.728 g/L versus 0.95 ± 0.017 mg/g). The phenolic compounds identification was carried out with a performance liquid chromatograph coupled to tandem mass spectrometry equipment (HPLC-ESI-MS). With this method, a list of polyphenols from OWWE and OCE was obtained. The antioxidant activity was measured in aqueous (DPPH) and emulsion (BCBT) systems. Using the DPPH assay, the results show that OWWE was more active than OCE and interestingly the extracts originating from mountainous areas were more active than those produced from plain areas (EC50 = 12.1 ± 5.6 μg/mL; EC50 = 157.7 ± 34.9 μg/mL, resp.). However, when the antioxidant activity was reversed in the BCBT, OCE produced from plain area was more potent than mountainous OCE. Testing by the gel diffusion assay, all the tested extracts have showed significant spectrum antibacterial activity against Staphylococcus aureus, whereas the biophenols extracts showed more limited activity against Escherichia coli and Streptococcus faecalis. PMID:26693221

  4. Antimicrobial Organometallic Dendrimers with Tunable Activity against Multidrug-Resistant Bacteria.

    PubMed

    Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola; Overy, David P; Lanteigne, Martin; McQuillan, Katherine; Kerr, Russell G

    2015-11-01

    Multidrug-resistant pathogens are an increasing threat to public health. In an effort to curb the virulence of these pathogens, new antimicrobial agents are sought. Here we report a new class of antimicrobial organometallic dendrimers with tunable activity against multidrug-resistant Gram-positive bacteria that included methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. Mechanistically, these redox-active, cationic organometallic dendrimers induced oxidative stress on bacteria and also disrupted the microbial cell membrane. The minimum inhibitory concentrations, which provide a quantitative measure of the antimicrobial activity of these dendrimers, were in the low micromolar range. AlamarBlue cell viability assay also confirms the antimicrobial activity of these dendrimers. Interestingly, these dendrimers were noncytotoxic to epidermal cell lines and to mammalian red blood cells, making them potential antimicrobial platforms for topical applications. PMID:26452022

  5. Antimicrobial activity of thin solid films of silver doped hydroxyapatite prepared by sol-gel method.

    PubMed

    Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

    2014-01-01

    In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x(Ag) = 0.5 are effective against E. coli and S. aureus after 24 h. PMID:24523630

  6. Preclinical screening of phyllanthus amarus ethanolic extract for its analgesic and antimicrobial activity

    PubMed Central

    Bhat, S. Sham; Hegde, K. Sundeep; Chandrashekhar, Sharath; Rao, S. N.; Manikkoth, Shyamjith

    2015-01-01

    Background: To discover a new agent which possesses dual property of analgesic and antimicrobial activity, thereby reducing the burden of polypharmacy. Phyllanthus amarus was screened for its analgesic and antimicrobial activities. Objectives: The objective was to evaluate the analgesic and antimicrobial activity, of P. amarus ethanolic extract (PAEE). Materials and Methods: The ethanolic extract of P. amarus was prepared using Soxhlet apparatus. An in vivo study using Swiss albino mice was done to screen the central and peripheral analgesic activity of P. amarus extract. The extract was administered at a dose of 100 mg/kg body weight orally. The peripheral analgesic activity was assessed using acetic acid induced writhing test. The central analgesic activity was assessed using Eddy's hot plate apparatus. An in vitro study was carried out to study the antimicrobial activity of the above extract using selected species of Streptococcus mutans, and S. salivarius. The antimicrobial activities were determined using the agar well method. Results: The ethanolic extract of P. amarus showed significant (P < 0.05) peripheral and central analgesic activity. In vitro antimicrobial screening indicated that the ethanolic extract had shown a zone of inhibition against S. mutans and S. salivarius in the agar wells. Conclusion: This study showed that PAEE exhibited significant analgesic and antimicrobial activities. PMID:26692753

  7. Examination of antimicrobial activity of selected non-antibiotic drugs.

    PubMed

    Kruszewska, Hanna; Zareba, Tomasz; Tyski, Stefan

    2004-12-01

    A variety of pharmaceutical preparations, which are applied in the management of non-infectious diseases, have shown in vitro some antimicrobial activity. These drugs are called "non-antibiotics". The aim of this study was to detect and characterize the antimicrobial activity of non-antibiotic drugs, selected from the preparations analysed during state control performed in the National Institute of Public Health in Poland. Over 180 of pharmaceutical preparations were randomly chosen from different groups of drugs. A surveillance study was performed on standard ATCC microbial strains used for drug control: S. aureus, E. coli, P. aeruginosa and C. albicans. It was shown that the drugs listed below inhibited growth of at least one of the examined strains: Actonel 5 mg tabl. (risedronate), Aldan 10 mg tabl. (amlodipine), Aleras 10 mg tabl. (cetirisine), Aspicam 15 mg tabl. (meloxicam), Baikadent 6 mg/g gel (flavons of Scutellariae), Debretin 100 mg tabl. (trimebutine), Ferro-Duo 100 mg tabl. (ferrum), Gastrovent 145 mg caps. (bismuth citrate), Ibum 200 mg caps., Upfen 200 mg tabl. (ibuprofen), Lastet 100 mg caps. (etoposide), Legalon 70 mg tabl. (sylimarin), Madopar 125 tabl. (benserazide, levodopa), Moxenil 100 mg tabl. (nimesulide), Neurotin 800 mg tabl. (gabapentin), Propranolol 40 mg tabl. (propranolol), Rexetin 20 mg tabl. (paroxetine), Salipax 20 mg caps. (fluoxetine), Selofen 10 mg caps. (zaleplon) Stenorol 0.6% powder (halofuginone), Stimuloton 50 mg tabl. (sertraline), Superoptim 0.3 mg tabl. (hipericine), Uversan 50 mg tabl. (arbutine from Arctostaphylos uva ursi). S. aureus strain was susceptible to the most of the drugs listed above. The lowest inhibitory concentration was found for sertraline and hipericine (0.16 and 0.075 mg/mL, respectively). PMID:15909927

  8. Antimicrobial and cytotoxic effects of phosphoric acid solution compared to other root canal irrigants

    PubMed Central

    PRADO, Maíra; da SILVA, Emmanuel João Nogueira Leal; DUQUE, Thais Mageste; ZAIA, Alexandre Augusto; FERRAZ, Caio Cezar Randi; de ALMEIDA, José Flávio Affonso; GOMES, Brenda Paula Figueiredo de Almeida

    2015-01-01

    Phosphoric acid has been suggested as an irrigant due to its effectiveness in removing the smear layer. Objectives : The purpose of this study was to compare the antimicrobial and cytotoxic effects of a 37% phosphoric acid solution to other irrigants commonly used in endodontics. Material and Methods : The substances 37% phosphoric acid, 17% EDTA, 10% citric acid, 2% chlorhexidine (solution and gel), and 5.25% NaOCl were evaluated. The antimicrobial activity was tested against Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Actinomyces meyeri, Parvimonas micra, Porphyromonas gingivalis, and Prevotella nigrescens according to the agar diffusion method. The cytotoxicity of the irrigants was determined by using the MTT assay. Results : Phosphoric acid presented higher antimicrobial activity compared to the other tested irrigants. With regard to the cell viability, this solution showed results similar to those with 5.25% NaOCl and 2% chlorhexidine (gel and solution), whereas 17% EDTA and 10% citric acid showed higher cell viability compared to other irrigants. Conclusion : Phosphoric acid demonstrated higher antimicrobial activity and cytotoxicity similar to that of 5.25% NaOCl and 2% chlorhexidine (gel and solution). PMID:26018307

  9. Antimicrobial activity of some medicinal plants from Ghana.

    PubMed

    Konning, G H; Agyare, C; Ennison, B

    2004-01-01

    The results of a preliminary antimicrobial screening of the methanol extracts of Aframomum melegueta, Piper guineense, Xylopia aethiopica, Zingiber officinale, medicinal plants of Ghana, are reported. PMID:14693222

  10. Antimicrobial activity of some medicinal plants from India.

    PubMed

    Samy, R Perumal

    2005-12-01

    The results of a preliminary antimicrobial screening of the methanol extracts of Zingiber officinale, Asteracantha longifolia, Citrus acida, Salacia microsperma and Tinospora cordifolia are reported. PMID:16229969

  11. Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties

    PubMed Central

    2011-01-01

    Background Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated. Results Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique. Conclusions The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile. PMID:21699688

  12. Preliminary Screening of Endophytic Fungi from Medicinal Plants in Malaysia for Antimicrobial and Antitumor Activity

    PubMed Central

    Radu, Son; Kqueen, Cheah Yoke

    2002-01-01

    The screening of antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, yeast and fungi was carried out on isopropanol extracts prepared from 121 isolates of endophytic fungi isolated from medicinal plants in Malaysia. Sensitivity was found to vary among the microorganisms. Bacillus subtilis, Saccharomyces cerevisiae and Alternaria sp. were susceptible to extracts from three, two and two isolates of endophytic fungi, respectively. None were found effective against Salmonella typhimurium. Sixteen endophytic fungal isolates tested were also found to exhibit antitumor activity in the yeast cell-based assay. PMID:22844221

  13. Antimicrobial, antioxidant and anti-inflammatory phenolic activities in extra virgin olive oil.

    PubMed

    Cicerale, S; Lucas, L J; Keast, R S J

    2012-04-01

    The Mediterranean diet is associated with a lower incidence of chronic degenerative diseases and higher life expectancy. These health benefits have been partially attributed to the dietary consumption of extra virgin olive oil (EVOO) by Mediterranean populations, and more specifically the phenolic compounds naturally present in EVOO. Studies involving humans and animals (in vivo and in vitro) have demonstrated that olive oil phenolic compounds have potentially beneficial biological effects resulting from their antimicrobial, antioxidant and anti-inflammatory activities. This paper summarizes current knowledge on the biological activities of specific olive oil phenolic compounds together with information on their concentration in EVOO, bioavailability and stability over time. PMID:22000808

  14. Colonic MUC2 mucin regulates the expression and antimicrobial activity of β-defensin 2

    PubMed Central

    Cobo, E R; Kissoon-Singh, V; Moreau, F; Chadee, K

    2015-01-01

    In this study we identified mechanisms at the colonic mucosa by which MUC2 mucin regulated the production of β-defensin in a proinflammatory milieu but functionally protected susceptible bacteria from its antimicrobial effects. The regulator role of MUC2 on production of β-defensin 2 in combination with the proinflammatory cytokine interleukin-1β (IL-1β) was confirmed using purified human colonic MUC2 mucin and colonic goblet cells short hairpin RNA (shRNA) silenced for MUC2. In vivo, Muc2−/− mice showed impaired β-defensin mRNA expression and peptide localization in the colon as compared with Muc2+/− and Muc2+/+ littermates. Importantly, purified MUC2 mucin abrogated the antimicrobial activity of β-defensin 2 against nonpathogenic and enteropathogenic Escherichia coli. Sodium metaperiodate oxidation of MUC2 removed the capacity of MUC2 to stimulate β-defensin production and MUC2's inhibition of defensin antimicrobial activity. This study highlights that a defective MUC2 mucin barrier, typical in inflammatory bowel diseases, may lead to deficient stimulation of β-defensin 2 and an unbalanced microbiota that favor the growth of β-defensin-resistant microbes such as Clostridium difficile. PMID:25921338

  15. Antimicrobial activities of silver used as a polymerization catalyst for a wound-healing matrix.

    PubMed

    Babu, Ranjith; Zhang, Jianying; Beckman, Eric J; Virji, Mohammed; Pasculle, William A; Wells, Alan

    2006-08-01

    Wound healing is a complex and orchestrated process that re-establishes the barrier and other functions of the skin. While wound healing proceeds apace in healthy individual, bacterial overgrowth and infection disrupts this process with significant morbidity and mortality. As such, any artificial matrix to promote wound healing must also control infecting microbes. We had earlier developed a two-part space-conforming gel backbone based on polyethyleneglycol (PEG) or lactose, which used ionic silver as the catalyst for gelation. As silver is widely used as an in vitro antimicrobial, use of silver as a catalyst for gelation provided the opportunity to assess its function as an anti-microbial agent in the gels. We found that these gels show bacteriostatic and bactericidal activity for a range of Gram-negative and Gram-positive organisms, including aerobic as well as anaerobic bacteria. This activity lasted for days, as silver leached out of the formed gels over a day in the manner of second-order decay. Importantly the gels did not limit either cell growth or viability, though cell migration was affected. Adding collagen I fragments to the gels corrected this effect on cell migration. We also found that the PEG gel did not interfere with hemostasis. These observations provide the basis for use of the gel backbones for incorporation of anesthetic agents and factors that promote wound repair. In conclusion, silver ions can serve dual functions of catalyzing gelation and providing anti-microbial properties to a biocompatible polymer. PMID:16635526

  16. Antimicrobial activities of silver used as a polymerization catalyst for a wound-healing matrix

    PubMed Central

    Babu, Ranjith; Zhang, Jianying; Beckman, Eric J.; Virji, Mohammed; Pasculle, William A.; Wells, Alan

    2007-01-01

    Wound healing is a complex and orchestrated process that re-establishes the barrier and other functions of the skin. While wound healing proceeds apace in healthy individual, bacterial overgrowth and infection disrupts this process with significant morbidity and mortality. As such, any artificial matrix to promote wound healing must also control infecting microbes. We had earlier developed a two-part space-conforming gel backbone based on polyethyleneglycol (PEG) or lactose, which used ionic silver as the catalyst for gelation. As silver is widely used as an in vitro antimicrobial, use of silver as a catalyst for gelation provided the opportunity to assess its function as an anti-microbial agent in the gels. We found that these gels show bacteriostatic and bactericidal activity for a range of Gram-negative and Gram-positive organisms, including aerobic as well as anaerobic bacteria. This activity lasted for days, as silver leached out of the formed gels over a day in the manner of second-order decay. Importantly the gels did not limit either cell growth or viability, though cell migration was affected. Adding collagen I fragments to the gels corrected this effect on cell migration. We also found that the PEG gel did not interfere with hemostasis. These observations provide the basis for use of the gel backbones for incorporation of anesthetic agents and factors that promote wound repair. In conclusion, silver ions can serve dual functions of catalyzing gelation and providing anti-microbial properties to a biocompatible polymer. PMID:16635526

  17. Evaluation of antimicrobial activity of silver nanoparticles for carboxymethylcellulose film applications in food packaging.

    PubMed

    Siqueira, Maria C; Coelho, Gustavo F; de Moura, Márcia R; Bresolin, Joana D; Hubinger, Silviane Z; Marconcini, José M; Mattoso, Luiz H C

    2014-07-01

    In this study, silver nanoparticles were prepared and incorporated into carboxymethylcellulose films to evaluate the antimicrobial activity for food packaging applications. The techniques carried out for material characterization were: infrared spectroscopy and thermal analysis for the silver nanoparticles and films, as well as particle size distribution for the nanoparticles and water vapor permeability for the films. The antimicrobial activity of silver nanoparticles prepared by casting method was investigated. The minimum inhibitory concentration (MIC) value of the silver nanoparticles to test Gram-positive (Enterococcus faecalis) and Gram-negative (Escherichia coli) microorganisms was carried out by the serial dilution technique, tested in triplicate to confirm the concentration used. The results were developed using the Mcfarland scale which indicates that the presence or absence of turbidity tube demonstrates the inhibition of bacteria in relation to the substance inoculated. It was found that the silver nanoparticles inhibited the growth of the tested microorganisms. The carboxymethylcellulose film embedded with silver nanoparticles showed the best antimicrobial effect against Gram-positive (E. faecalis) and Gram-negative (E. coli) bacteria (0.1 microg cm(-3)). PMID:24758059

  18. Alarin but not its alternative-splicing form, GALP (Galanin-like peptide) has antimicrobial activity

    SciTech Connect

    Wada, Akihiro; Wong, Pooi-Fong; Hojo, Hironobu; Hasegawa, Makoto; Ichinose, Akitoyo; Llanes, Rafael; Kubo, Yoshinao; Senba, Masachika; Ichinose, Yoshio

    2013-05-03

    Highlights: • Alarin inhibits the growth of E. coli but not S. aureus. • Alarin’s potency is comparable to LL-37 in inhibiting the growth of E. coli. • Alarin can cause bacterial membrane blebbing. • Alalin does not induce hemolysis on erythrocytes. -- Abstract: Alarin is an alternative-splicing form of GALP (galanin-like peptide). It shares only 5 conserved amino acids at the N-terminal region with GALP which is involved in a diverse range of normal brain functions. This study seeks to investigate whether alarin has additional functions due to its differences from GALP. Here, we have shown using a radial diffusion assay that alarin but not GALP inhibited the growth of Escherichia coli (strain ML-35). The conserved N-terminal region, however, remained essential for the antimicrobial activity of alarin as truncated peptides showed reduced killing effect. Moreover, alarin inhibited the growth of E. coli in a similar potency as human cathelicidin LL-37, a well-studied antimicrobial peptide. Electron microscopy further showed that alarin induced bacterial membrane blebbing but unlike LL-37, it did not cause hemolysis of erythrocytes. In addition, alarin is only active against the gram-negative bacteria, E. coli but not the gram-positive bacteria, Staphylococcus aureus. Thus, these data suggest that alarin has potentials as an antimicrobial and should be considered for the development in human therapeutics.

  19. Antimicrobial Activity of Artemisinin and Precursor Derived from In Vitro Plantlets of Artemisia annua L.

    PubMed Central

    Appalasamy, Suganthi; Lo, Kiah Yann; Ch'ng, Song Jin; Nornadia, Ku; Othman, Ahmad Sofiman; Chan, Lai-Keng

    2014-01-01

    Artemisia annua L., a medicinal herb, produces secondary metabolites with antimicrobial property. In Malaysia due to the tropical hot climate, A. annua could not be planted for production of artemisinin, the main bioactive compound. In this study, the leaves of three in vitro A. annua L. clones were, extracted and two bioactive compounds, artemisinin and a precursor, were isolated by thin layer chromatography. These compounds were found to be effective in inhibiting the growth of Gram-positive and Gram-negative bacteria but not Candida albicans. Their antimicrobial activity was similar to that of antibactericidal antibiotic streptomycin. They were found to inhibit the growth of the tested microbes at the minimum inhibition concentration of 0.09 mg/mL, and toxicity test using brine shrimp showed that even the low concentration of 0.09 mg/mL was very lethal towards the brine shrimps with 100% mortality rate. This study hence indicated that in vitro cultured plantlets of A. annua can be used as the alternative method for production of artemisinin and its precursor with antimicrobial activities. PMID:24575401

  20. Antimicrobial activity of artemisinin and precursor derived from in vitro plantlets of Artemisia annua L.

    PubMed

    Appalasamy, Suganthi; Lo, Kiah Yann; Ch'ng, Song Jin; Nornadia, Ku; Othman, Ahmad Sofiman; Chan, Lai-Keng

    2014-01-01

    Artemisia annua L., a medicinal herb, produces secondary metabolites with antimicrobial property. In Malaysia due to the tropical hot climate, A. annua could not be planted for production of artemisinin, the main bioactive compound. In this study, the leaves of three in vitro A. annua L. clones were, extracted and two bioactive compounds, artemisinin and a precursor, were isolated by thin layer chromatography. These compounds were found to be effective in inhibiting the growth of Gram-positive and Gram-negative bacteria but not Candida albicans. Their antimicrobial activity was similar to that of antibactericidal antibiotic streptomycin. They were found to inhibit the growth of the tested microbes at the minimum inhibition concentration of 0.09 mg/mL, and toxicity test using brine shrimp showed that even the low concentration of 0.09 mg/mL was very lethal towards the brine shrimps with 100% mortality rate. This study hence indicated that in vitro cultured plantlets of A. annua can be used as the alternative method for production of artemisinin and its precursor with antimicrobial activities. PMID:24575401

  1. Antimicrobial activity of Nerolidol and its derivatives against airborne microbes and further biological activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nerolidol and its derivatives, namely cis-nerolidol, O-methyl-nerolidol, O-ethyl-nerolidol, (-)-alpha-bisabolol, trans,trans-farnesol and its main natural source Cabreuva essential oil, were tested for their antimicrobial activity against airborne microbes and antifungal properties against plant pat...

  2. Antimicrobial activity of lemongrass oil against Salmonella enterica on organic leafy greens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to discover new and natural antimicrobial treatments against Salmonella Newport on organic produce, we evaluated the antimicrobial effect of lemongrass essential oil on four different types of organic leafy greens inoculated with S. Newport. The effects of lemongrass treatment exposure...

  3. Antimicrobial polymers - The antibacterial effect of photoactivated nano titanium dioxide polymer composites

    SciTech Connect

    Huppmann, T. Leonhardt, S. E-mail: erhard.krampe@tum.de; Krampe, E. E-mail: erhard.krampe@tum.de; Wintermantel, E.; Yatsenko, S. Radovanovic, I. E-mail: m.bastian@skz.de; Bastian, M. E-mail: m.bastian@skz.de

    2014-05-15

    To obtain a polymer with antimicrobial properties for medical and sanitary applications nanoscale titanium dioxide (TiO{sub 2}) particles have been incorporated into a medical grade polypropylene (PP) matrix with various filler contents (0 wt %, 2 wt %, 10 wt % and 15 wt %). The standard application of TiO{sub 2} for antimicrobial efficacy is to deposit a thin TiO{sub 2} coating on the surface. In contrast to the common way of applying a coating, TiO{sub 2} particles were applied into the bulk polymer. With this design we want to ensure antimicrobial properties even after application of impact effects that could lead to surface defects. The filler material (Aeroxide® TiO{sub 2} P25, Evonik) was applied via melt compounding and the compounding parameters were optimized with respect to nanoscale titanium dioxide. In a next step the effect of UV-irradiation on the compounds concerning their photocatalytic activity, which is related to the titanium dioxide amount, was investigated. The photocatalytic effect of TiO{sub 2}-PP-composites was analyzed by contact angle measurement, by methylene blue testing and by evaluation of inactivation potential for Escherichia coli (E.coli) bacteria. The dependence of antimicrobial activity on the filler content was evaluated, and on the basis of different titanium dioxide fractions adequate amounts of additives within the compounds were discussed. Specimens displayed a higher photocatalytic and also antimicrobial activity and lower contact angles with increasing titania content. The results suggest that the presence of titania embedded in the PP matrix leads to a surface change and a photocatalytic effect with bacteria killing result.

  4. Antimicrobial Activity of Peganum Harmala L. on Streptococcus mutans Compared to 0.2% Chlorhexidine

    PubMed Central

    Motamedifar, Mohammad; Khosropanah, Hengameh; Dabiri, Shima

    2016-01-01

    Statement of the Problem Dental caries is one the most prevalent diseases that affects humans throughout their lives. Streptococcus mutans (S. mutans) is recognized as the most important microorganism during tooth cariogenicity. Reducing this germ in oral cavity can reduce the rate of tooth decays in humans. Purpose The present study compared the antimicrobial activity of ethanolic extract of Peganum harmala L. seeds and 0.2% chlorhexidine on S. mutans. Materials and Method Agar diffusion technique and micro broth dilution method were employed to test the antimicrobial effects of these two agents on S. mutans. Moreover, the cytotoxicity of ethanolic extract of P. harmala was studied on Vero cells by MTT (thiazolyl blue tetrazolium dye) colorimetric method. The data were analyzed with descriptive methods. Results Concentrations of 50, 25, and 12.5 mg/mL of the extract made inhibition zones of bacterial growth around the wells; but, lower concentrations could not inhibit the growth of S. mutans. Besides, the antimicrobial effect of 0.2% chlorhexidine was more than 50 mg/mL of the extract. Minimum inhibitory concentration (MIC) of the extract on S. mutans was 1.83±0.6 mg/mL and minimum bactericidal concentration (MBC) was 4.3±1 mg/mL. The MIC and MBC for 0.2% chlorhexidine were reported to be 0.19 mg/mL, and 0.78 mg/mL, respectively. The extract concentrations more than 0.5 mg/mL were toxic and caused more than 50% Vero cell death. Conclusion Despite the remarkable antimicrobial effects of high concentrations of P. harmala on S. mutans, high cell toxicity of this plant would restrict its in vivo therapeutic use. PMID:27602397

  5. Antimicrobial activity and phytochemical analysis of crude extracts and essential oils from medicinal plants.

    PubMed

    Silva, N C C; Barbosa, L; Seito, L N; Fernandes, A

    2012-01-01

    We aimed to establish a phytochemical analysis of the crude extracts and performed GC-MS of the essential oils (EOs) of Eugenia uniflora L. (Myrtaceae) and Asteraceae species Baccharis dracunculifolia DC, Matricaria chamomilla L. and Vernonia polyanthes Less, as well as determining their antimicrobial activity. Establishment of the minimal inhibitory concentrations of the crude extracts and EOs against 16 Staphylococcus aureus and 16 Escherichia coli strains from human specimens was carried out using the dilution method in Mueller-Hinton agar. Some phenolic compounds with antimicrobial properties were established, and all EOs had a higher antimicrobial activity than the extracts. Matricaria chamomilla extract and E. uniflora EO were efficient against S. aureus strains, while E. uniflora and V. polyanthes extracts and V. polyanthes EO showed the best antimicrobial activity against E. coli strains. Staphylococcus aureus strains were more susceptible to the tested plant products than E. coli, but all natural products promoted antimicrobial growth inhibition. PMID:22007687

  6. Supercritical carbon dioxide extraction of compounds with antimicrobial activity from Origanum vulgare L.: determination of optimal extraction parameters.

    PubMed

    Santoyo, S; Cavero, S; Jaime, L; Ibañez, E; Señoráns, F J; Reglero, G

    2006-02-01

    Oregano leaves were extracted using a pilot-scale supercritical fluid extraction plant under a wide range of extraction conditions, with the goal of determining the extraction and fractionation conditions to obtain extracts with optimal antimicrobial activity. In this investigation, the essential oil-rich fractions were selectively precipitated in the second separator, and their chemical composition and antimicrobial activity were investigated. Gas chromatography-mass spectrometry analysis of the various fractions resulted in the identification of 27 compounds of the essential oil. The main components of these fractions were carvacrol, trans-sabinene hydrate, cis-piperitol, borneol, terpinen-4-ol, and linalool. Antimicrobial activity was investigated by the disk diffusion and broth dilution methods against six different microbial species, including two gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), a yeast (Candida albicans), and a fungus (Aspergillus niger). All of the supercritical fluid extraction fractions obtained showed antimicrobial activity against all of the microorganisms tested, although the most active fraction was the one obtained in experiment 5 (fraction was obtained with 7% ethanol at 150 bar and 40 degrees C). C. albicans was the most sensitive microorganism to the oregano extracts, whereas the least susceptible was A. niger. Carvacrol, sabinene hydrate, borneol, and linalool standards also showed antimicrobial activity against all of the microorganisms tested, with carvacrol being the most effective. Consequently, it was confirmed that essential oil from experiment 5, with the best antimicrobial activity, also presented the highest quantity of carvacrol. PMID:16496578

  7. Scolopendin 2, a cationic antimicrobial peptide from centipede, and its membrane-active mechanism.

    PubMed

    Lee, Heejeong; Hwang, Jae-Sam; Lee, Jaeho; Kim, Jae Il; Lee, Dong Gun

    2015-02-01

    Scolopendin 2 is a 16-mer peptide (AGLQFPVGRIGRLLRK) derived from the centipede Scolopendra subspinipes mutilans. We observed that this peptide exhibited antimicrobial activity in a salt-dependent manner against various fungal and bacterial pathogens and showed no hemolytic effect in the range of 1.6 μM to 100 μM. Circular dichroism analysis showed that the peptide has an α-helical properties. Furthermore, we determined the mechanism(s) of action using flow cytometry and by investigating the release of intracellular potassium. The results showed that the peptide permeabilized the membranes of Escherichia coli O157 and Candida albicans, resulting in loss of intracellular potassium ions. Additionally, bis-(1,3-dibutylbarbituric acid) trimethine oxonol and 3,3'-dipropylthiacarbocyanine iodide assays showed that the peptide caused membrane depolarization. Using giant unilamellar vesicles encapsulating calcein and large unilamellar vesicles containing fluorescein isothiocyanate-dextran, which were similar in composition to typical E. coli O157 and C. albicans membranes, we demonstrated that scolopendin 2 disrupts membranes, resulting in a pore size between 4.8 nm and 5.0 nm. Thus, we have demonstrated that a cationic antimicrobial peptide, scolopendin 2, exerts its broad-spectrum antimicrobial effects by forming pores in the cell membrane. PMID:25462167

  8. Antimicrobial activity of plumbagin, a naturally occurring naphthoquinone from Plumbago rosea, against Staphylococcus aureus and Candida albicans.

    PubMed

    Nair, Sweatha V; Baranwal, Gaurav; Chatterjee, Maitrayee; Sachu, Arun; Vasudevan, Anil Kumar; Bose, Chinchu; Banerji, Asoke; Biswas, Raja

    2016-06-01

    Candida albicans and Staphylococcus aureus are opportunistic pathogens. Despite causing a number of independent infections, both pathogens can co-infect to cause urinary tract infections, skin infections, biofilm associated infections, sepsis and pneumonia. Infections of these two pathogens especially their biofilm associated infections are often difficult to treat using currently available anti-bacterial and anti-fungal agents. In order to identify a common anti-microbial agent which could confer a broad range of protection against their infections, we screened several phytochemicals and identified plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone), a phytochemical from Plumbago species as a potent antimicrobial agent against S. aureus and C. albicans, with a minimum inhibitory concentration of 5μg/ml. Antimicrobial activity of plumbagin was validated using an ex-vivo porcine skin model. For better understanding of the antimicrobial activity of plumbagin, a Drosophila melanogaster infection model was used, where D. melanogaster was infected using S. aureus and C. albicans, or with both organisms. The fly's survival rate was dramatically increased when infected flies were treated using plumbagin. Further, plumbagin was effective in preventing and dispersing catheter associated biofilms formed by these pathogens. The overall results of this work provides evidence that plumbagin, possesses an excellent antimicrobial activity which should be explored further for the treatment of S. aureus and C. albicans infections. PMID:27212459

  9. Native Thrombocidin-1 and Unfolded Thrombocidin-1 Exert Antimicrobial Activity via Distinct Structural Elements

    PubMed Central

    Kwakman, Paulus H. S.; Krijgsveld, Jeroen; de Boer, Leonie; Nguyen, Leonard T.; Boszhard, Laura; Vreede, Jocelyne; Dekker, Henk L.; Speijer, Dave; Drijfhout, Jan W.; te Velde, Anje A.; Crielaard, Wim; Vogel, Hans J.; Vandenbroucke-Grauls, Christina M. J. E.; Zaat, Sebastian A. J.

    2011-01-01

    Chemokines (chemotactic cytokines) can have direct antimicrobial activity, which is apparently related to the presence of a distinct positively charged patch on the surface. However, chemokines can retain antimicrobial activity upon linearization despite the loss of their positive patch, thus questioning the importance of this patch for activity. Thrombocidin-1 (TC-1) is a microbicidal protein isolated from human blood platelets. TC-1 only differs from the chemokine NAP-2/CXCL7 by a two-amino acid C-terminal deletion, but this truncation is crucial for antimicrobial activity. We assessed the structure-activity relationship for antimicrobial activity of TC-1. Reduction of the charge of the TC-1-positive patch by replacing lysine 17 with alanine reduced the activity against bacteria and almost abolished activity against the yeast Candida albicans. Conversely, augmentation of the positive patch by increasing charge density or size resulted in a 2–3-fold increased activity against Staphylococcus aureus, Escherichia coli, and Bacillus subtilis but did not substantially affect activity against C. albicans. Reduction of TC-1 resulted in loss of the folded conformation, but this disruption of the positive patch did not affect antimicrobial activity. Using overlapping 15-mer synthetic peptides, we demonstrate peptides corresponding to the N-terminal part of TC-1 to have similar antimicrobial activity as intact TC-1. Although we demonstrate that the positive patch is essential for activity of folded TC-1, unfolded TC-1 retained antimicrobial activity despite the absence of a positive patch. This activity is probably exerted by a linear peptide stretch in the N-terminal part of the molecule. We conclude that intact TC-1 and unfolded TC-1 exert antimicrobial activity via distinct structural elements. PMID:22025617

  10. In vitro antimicrobial effect of the tissue conditioner containing silver nanoparticles

    PubMed Central

    2011-01-01

    PURPOSE The aim of this study was to identify in vitro antimicrobial activity of the tissue conditioner containing silver nanoparticles on microbial strains, Staphylococcus aureus, Streptococcus mutans and Candida albicans. MATERIALS AND METHODS Experimental disc samples (20.0×3.0 mm) of tissue conditioner (GC Soft-Liner, GC cooperation, Tokyo, Japan) containing 0.1 - 3.0% silver nanoparticles (0%: control) were fabricated. Samples were placed on separate culture plate dish and microbial suspensions (100 µL) of tested strains were inoculated then incubated at 37℃. Microbial growth was verified at 24 hrs and 72 hrs and the antimicrobial effects of samples were evaluated as a percentage of viable cells in withdrawn suspension (100 µL). Data were recorded as the mean of three colony forming unit (CFU) numerations and the borderline of the antimicrobial effect was determined at 0.1% viable cells. RESULTS A 0.1% silver nanoparticles combined to tissue conditioner displayed minimal bactericidal effect against Staphylococcus aureus and Streptococcus mutans strains, a 0.5% for fungal strain. Control group did not show any microbial inhibitory effect and there were no statistical difference between 24 hrs and extended 72 hrs incubation time (P > .05). CONCLUSION Within the limitation of this in vitro study, the results suggest that the tissue conditioner containing silver nanoparticles could be an antimicrobial dental material in denture plaque control. Further mechanical stability and toxicity studies are still required. PMID:21503189

  11. Antimicrobial effects of wine: separating the role of polyphenols, pH, ethanol, and other wine components.

    PubMed

    Boban, Natasa; Tonkic, Marija; Budimir, Danijela; Modun, Darko; Sutlovic, Davorka; Punda-Polic, Volga; Boban, Mladen

    2010-06-01

    While the antimicrobial effectiveness of wine is well documented, relative contributions of the wine components to its antimicrobial activity is controversial. To separate the role of wine phenolics, ethanol, and pH from other wine constituents, the antimicrobial effects of intact wine were compared to that of phenols-stripped wine, dealcoholized wine, ethanol, and low pH applied separately and in combination, against 2 common foodborne pathogens, Salmonella enterica serovar Enteritidis and Escherichia coli. All samples were biochemically characterized with respect to their total phenolics and resveratrol content, antioxidant capacity, ethanol content, and pH. Antioxidative activity of the samples corresponded to their total phenolics content. Except for respective controls, pH and ethanol content were similar in all samples. The order of antibacterial activity of the samples was: intact wine > phenols-stripped wine > dealcoholized wine > combination of ethanol and low pH > low pH > ethanol. Separate application of ethanol or low pH showed negligible antibacterial activity while their combination showed synergistic effect. Antibacterial activity of the samples could not be related to their total phenolics and resveratrol content, antioxidant capacity, ethanol content, or pH. Our study indicates that antimicrobial activity of complex solutions such as intact wine cannot be exclusively attributed to its phenolic or nonphenolic constituents, nor can the antimicrobial activity of wine be predicted on the basis of its particular components. PMID:20629891

  12. Search of antimicrobial activity of selected non-antibiotic drugs.

    PubMed

    Kruszewska, Hanna; Zareba, Tomasz; Tyski, Stefan

    2002-01-01

    A variety of pharmaceutical preparations, which are applied in the management of non-infectious diseases, have shown in vitro some antimicrobial activity. These drugs are called "non-antibiotics". The aim of this study was to detect and characterise the antimicrobial activity of non-antibiotic drugs. selected from the preparations analysed during state control performed at the Drug Institute in Poland. Over 160 pharmaceutical preparations were randomly chosen from different groups of drugs. The surveillance study was performed on standard ATCC microbial strains used for drug control: S aureus, E. coil, P. aeruginosa and C. albicans. It was shown that the drugs listed below inhibited growth of at least one of the examined strains:acyclovir (Awirol 5%, cream), alendronate (Alenato 5 mg, tabl.), alverine (Meteospasmyl 20 mg, caps.), butorphanole (Butamidor 10 mg/ml, amp.), clodronate (Sindronat 400 mg, caps), diclofenac (Olfen 75 mg, amp.), emadastine (Emadine 0.05%, eye dr.), etodolac (Febret 200 mg, caps.), fluvastatine (Lescol 40 mg, tabl.), ketamine (Ketamidor 10%, amp.), levocabastine (Histimet 0.5 mg/ml, eye dr.), losartan (Lorista 50 mg, tabl.), matipranolol (Betaman 0.3% eye dr.), mesalazine (Pentasa 1%, susp.), naproxen (Nalgesin 550 mg, tabl.), oxaprosine (Reumax 600 mg, tabl.), oxymethazoline (Nasivin 0.025%, nose dr.), proxymetacaine (Alcaine 0.5%, eye dr.), ribavirin (Rebetol 200 mg, caps.), rutoside with ascorbic acid (Cerutin 20+200 mg, tabl.), sulodexide (Vessel due F, 250 LSU, caps.), tegaserole (Zelmac 50 mg, tabl.), telmisartan (Pritor 20 mg, tabl.), temosolomide (Temodal 100 mg, caps.), ticlopidine (Ticlid 250 mg, tabl.), tolfenamic acid (Migea rapid 200 mg, tabl.), tramadole (Tramundin 100 mg, tabl.), tropicamide (Tropicamidum 1%, eye dr.). Staphylococcus aureus was susceptible to most of the drugs listed above. Ticlopidine showed activity against S. aureus, E. coli and C. albicans (MICs equal to: 0.45; 0.45 and 0.65 mg/ml, respectively

  13. Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the effects of storage and handling conditions on the antimicrobial activity of biodegradable composite films (polylactic acid and sugar beet pulp) coated with allyl isothiocyanate (AIT). Polylactic acid (PLA) and chitosan were incorporated with AIT and coated on one side of the film. T...

  14. Antimicrobial and antioxidant activities of three Mentha species essential oils.

    PubMed

    Mimica-Dukić, Neda; Bozin, Biljana; Soković, Marina; Mihajlović, Biserka; Matavulj, Milan

    2003-05-01

    The present study describes the antimicrobial activity and free radical scavenging capacity (RSC) of essential oils from Mentha aquatica L., Mentha longifolia L., and Mentha piperita L. The chemical profile of each essential oil was determined by GC-MS and TLC. All essential oils exhibited very strong antibacterial activity, in particularly against Esherichia coli strains. The most powerful was M. piperita essential oil, especially towards multiresistant strain of Shigella sonei and Micrococcus flavus ATTC 10,240. All tested oils showed significant fungistatic and fungicidal activity [expressed as minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values, respectively], that were considerably higher than those of the commercial fungicide bifonazole. The essential oils of M. piperita and M. longifolia were found to be more active than the essential oil of M. aquatica. Especially low MIC (4 microL/mL) and MFC (4 microL/mL) were found with M. piperita oil against Trichophyton tonsurans and Candida albicans (both 8 microL/mL). The RSC was evaluated by measuring the scavenging activity of the essential oils on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and OH radicals. All examined essential oils were able to reduce DPPH radicals into the neutral DPPH-H form, and this activity was dose-dependent. However, only the M. piperita oil reduced DPPH to 50 % (IC50 = 2.53 microg/mL). The M. piperita essential oil also exhibited the highest OH radical scavenging activity, reducing OH radical generation in the Fenton reaction by 24 % (pure oil). According to GC-MS and TLC (dot-blot techniques), the most powerful scavenging compounds were monoterpene ketones (menthone and isomenthone) in the essential oils of M. longifolia and M. piperita and 1,8-cineole in the oil of M. aquatica. PMID:12802721

  15. Antimicrobial and antioxidant activities of plants from northeast of Mexico.

    PubMed

    Salazar-Aranda, Ricardo; Pérez-López, Luis Alejandro; López-Arroyo, Joel; Alanís-Garza, Blanca Alicia; Waksman de Torres, Noemí

    2011-01-01

    Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000 μg ml(-1). We report here for the first time activity of Ceanothus coeruleus against S. aureus (flowers, minimal inhibitory concentration (MIC) 125 μg ml(-1)), C. glabrata (MICs 31.25 μg ml(-1)) and C. parapsilosis (MICs between 31.25 and 125 μg ml(-1)); Chrysanctinia mexicana against C. glabrata (MICs 31.25 μg ml(-1)); Colubrina greggii against E. faecalis (MICs 250 μg ml(-1)) and Cordia boissieri against C. glabrata (MIC 125 μg ml(-1)). Furthermore, this is the first report about antioxidant activity of extracts from Ceanothus coeruleus, Chrysanctinia mexicana, Colubrina greggii and Cyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the species Ceanothus coeruleus, Schinus molle, Colubrina greggii and Cordia boissieri. PMID:19770266

  16. Antimicrobial and Antioxidant Activities of Plants from Northeast of Mexico

    PubMed Central

    Salazar-Aranda, Ricardo; Pérez-López, Luis Alejandro; López-Arroyo, Joel; Alanís-Garza, Blanca Alicia; Waksman de Torres, Noemí

    2011-01-01

    Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 100