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Sample records for plant antimicrobial agents

  1. Plant nutraceuticals as antimicrobial agents in food preservation: terpenoids, polyphenols and thiols.

    Science.gov (United States)

    Gutiérrez-Del-Río, Ignacio; Fernández, Javier; Lombó, Felipe

    2018-05-16

    Synthetic food additives generate a negative perception in consumers. Therefore, food manufacturers search for safer natural alternatives as those involving phytochemicals and plant essential oils. These bioactives have antimicrobial activities widely proved in in vitro tests. Foodborne diseases cause thousands of deaths and millions of infections every year, mainly due to pathogenic bacteria as Salmonella spp., Campylobacter spp., Escherichia coli, Bacillus cereus, Listeria monocytogenes or Staphylococcus aureus. This review summarizes industrially interesting antimicrobial bioactivities, as well as their mechanisms of action, for three main types of plant nutraceuticals, terpenoids (as carnosic acid), polyphenols (as quercetin) and thiols (as allicin), which are important constituents of plant essential oils with a broad range of antimicrobial effects. These phytochemicals are widely distributed in fruits and vegetables and are really useful in food preservation as they inhibit microbial growth. Copyright © 2018. Published by Elsevier B.V.

  2. Antimicrobial and anti-Quorum Sensing activities of selected medicinal plants of Ethiopia: Implication for development of potent antimicrobial agents.

    Science.gov (United States)

    Bacha, Ketema; Tariku, Yinebeb; Gebreyesus, Fisseha; Zerihun, Shibru; Mohammed, Ali; Weiland-Bräuer, Nancy; Schmitz, Ruth A; Mulat, Mulugeta

    2016-07-11

    Traditional medicinal plants have been used as an alternative medicine in many parts of the world, including Ethiopia. There are many documented scientific reports on antimicrobial activities of the same. To our knowledge, however, there is no report on the anti-Quorum Sensing (Quorum Quenching, QQ) potential of traditional Ethiopian medicinal plants. As many of the opportunistic pathogenic bacteria depend on Quorum Sensing (QS) systems to coordinate their virulence expression, interference with QS could be a novel approach to control bacterial infections. Thus, the aim of this study was to evaluate selected medicinal plants from Ethiopia for their antimicrobial activities against bacterial and fungal pathogens; and to assess the interference of these plant extracts with QS of bacteria. Antimicrobial activities of plant extracts (oil, resins and crude extracts) were evaluated following standard agar diffusion technique. The minimum inhibitory concentrations (MIC) of potent extracts were determined using 96 well micro-titer plates and optical densities were measured using an ELISA Microplate reader. Interference with Quorum Sensing activities of extracts was determined using the recently established E. coli based reporter strain AI1-QQ.1 and signaling molecule N-(ß-ketocaproyl)-L-homoserine lactone (3-oxo-C6-HSL). Petroleum ether extract of seed of Nigella sativa exhibited the highest activity against both the laboratory isolated Bacillus cereus [inhibition zone (IZ), 44 ± 0.31 mm] and B. cereus ATCC 10987 (IZ, 40 ± 2.33 mm). Similarly, oil extract from mature ripe fruit husk of Aframomum corrorima and mature unripe fruit of A. corrorima revealed promising activities against Candida albicans ATCC 90028 (IZ, 35 ± 1.52 mm) and Staphylococcus aureus DSM 346 (IZ, 25 ± 1.32 mm), respectively. Antimicrobial activities of oil extract from husk of A. corrorima and petroleum ether extract of seed of N. sativa were significantly higher than that of

  3. Antimicrobial agents of plant origin for the treatment of phlogistic-infectious diseases of the lower female genital tract

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    Francesco Gon

    2012-12-01

    Full Text Available The phlogistic-infectious diseases of the lower female genital tract are one of the most widespread obstetricgynecologic issues, due to treatment failures that cause frequent relapses and to the adverse effects of some commonly used drugs.The most common vaginal syndromes are due to uncontrolled growth of bacteria or fungi which replace the normal vaginal flora, causing phlogistic and infectious based diseases. These infections are treated with anti-inflammatory and antibiotic therapy; however, the emergence of resistant strains and the ability of many microorganisms to grow inside biofilms severely reduce the repertoire of useful agents.Thus, in the last years increasing interest has been focused toward compounds of plant origin with anti-microbial properties. In the present work, we studied the antimicrobial activity of fractions obtained from endemic plants of Sardinia towards microorganisms that frequently are involved in vaginal infectious diseases: Streptococcus agalactiae, Gardnerella vaginalis and Candida albicans.

  4. Plants of the Melaleuca Genus as Antimicrobial Agents: From Farm to Pharmacy.

    Science.gov (United States)

    Sharifi-Rad, Javad; Salehi, Bahare; Varoni, Elena Maria; Sharopov, Farukh; Yousaf, Zubaida; Ayatollahi, Seyed Abdulmajid; Kobarfard, Farzad; Sharifi-Rad, Mehdi; Afdjei, Mohammad Hossain; Sharifi-Rad, Majid; Iriti, Marcello

    2017-10-01

    Plants belonging to Melaleuca genus (Myrtaceae family) are native to Oceania, where they have been used for ages by Aborigine people in Australian traditional medicine, mainly because of their broad-spectrum antimicrobial activity. Although, M. linariifolia, M. dissitiflora, and other species of Melaleuca can also be used, the tea tree oil, an essential oil obtained from M. alternifolia shows the longest history of medicinal uses. Tea tree oil contains for the 80-90% several monoterpenes (terpinen-4-ol, α-terpinene, 1,8-cineol, p-cymene, α-terpineol, α-pinene, terpinolene, limonene, and sabinene). Sesquiterpenes and aromatic compounds further compose this oil. The essential oil of Melaleuca spp. has been reported to possess effective antibacterial and antifungal properties in vitro. In particular, data show that 1,8-cineol, terpinen-4-ol and methyl eugenol play the key role in mediating this oil's antimicrobial activity. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Development and Sequential Analysis of a New Multi-Agent, Anti-Acne Formulation Based on Plant-Derived Antimicrobial and Anti-Inflammatory Compounds

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    Crina Saviuc

    2017-01-01

    Full Text Available The antibacterial and anti-inflammatory potential of natural, plant-derived compounds has been reported in many studies. Emerging evidence indicates that plant-derived essential oils and/or their major compounds may represent a plausible alternative treatment for acne, a prevalent skin disorder in both adolescent and adult populations. Therefore, the purpose of this study was to develop and subsequently analyze the antimicrobial activity of a new multi-agent, synergic formulation based on plant-derived antimicrobial compounds (i.e., eugenol, β-pinene, eucalyptol, and limonene and anti-inflammatory agents for potential use in the topical treatment of acne and other skin infections. The optimal antimicrobial combinations selected in this study were eugenol/β-pinene/salicylic acid and eugenol/β-pinene/2-phenoxyethanol/potassium sorbate. The possible mechanisms of action revealed by flow cytometry were cellular permeabilization and inhibition of efflux pumps activity induced by concentrations corresponding to sub-minimal inhibitory (sub-MIC values. The most active antimicrobial combination represented by salycilic acid/eugenol/β-pinene/2-phenoxyethanol/potassium sorbate was included in a cream base, which demonstrated thermodynamic stability and optimum microbiological characteristics.

  6. Effect of Plant Antimicrobial Agents Containing Marinades on Storage Stability and Microbiological Quality of Broiler Chicken Cuts Packed with Modified Atmosphere Packaging.

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    Alakomi, H-L; Maukonen, J; Honkapää, K; Storgårds, E; Quirin, K-W; Yang, B; Saarela, M

    2017-10-01

    The food industry, including the meat industry, is currently looking for natural preservatives to prevent the growth of harmful microbes in foods. The potential of plant-derived antimicrobial extracts to increase the shelf life and to delay the microbiological spoilage of marinated broiler chicken cuts in modified atmosphere packages during cold storage was investigated in this study. We evaluated the impact of aqueous ethanolic extracts of Finnish sea buckthorn berries and lingonberries and supercritical CO 2 -extracted herbal extracts from an antimicrobial blend and oregano leaves on the shelf life of broiler meat. The commercial antimicrobial blend extract and the oregano extract inhibited the growth of lactic acid bacteria (LAB) and Brochothrix thermosphacta in the marinated samples. The antimicrobial blend extract also reduced the growth of psychrotrophic aerobic bacteria, whereas the sea buckthorn and lingonberry extracts did not. Only minor antimicrobial activity against Enterobacteriaceae by all the extracts was observed. Plate count analysis, denaturing gradient gel electrophoresis, and quantitative real-time PCR indicated that LAB, which are the major spoilage group in marinated modified atmosphere-packaged poultry products, were not significantly affected by the berry extracts studied. During this shelf-life study, LAB isolates of Lactobacillus and Leuconostoc were identified in the marinated samples. Antimicrobial blends and oregano leaf extracts can act as antimicrobial agents in marinade blends, although tailoring of the dose is needed because of their strong taste. Further studies for exploiting synergistic effects of plant extracts could contribute to the development of potential and more effective antimicrobial blends. Studies are needed in meat matrices and in product applications to demonstrate the efficacy of these compounds.

  7. Animal venoms as antimicrobial agents.

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    Perumal Samy, Ramar; Stiles, Bradley G; Franco, Octavio L; Sethi, Gautam; Lim, Lina H K

    2017-06-15

    Hospitals are breeding grounds for many life-threatening bacteria worldwide. Clinically associated gram-positive bacteria such as Staphylococcus aureus/methicillin-resistant S. aureus and many others increase the risk of severe mortality and morbidity. The failure of antibiotics to kill various pathogens due to bacterial resistance highlights the urgent need to develop novel, potent, and less toxic agents from natural sources against various infectious agents. Currently, several promising classes of natural molecules from snake (terrestrial and sea), scorpion, spider, honey bee and wasp venoms hold promise as rich sources of chemotherapeutics against infectious pathogens. Interestingly, snake venom-derived synthetic peptide/snake cathelicidin not only has potent antimicrobial and wound-repair activity but is highly stable and safe. Such molecules are promising candidates for novel venom-based drugs against S. aureus infections. The structure of animal venom proteins/peptides (cysteine rich) consists of hydrophobic α-helices or β-sheets that produce lethal pores and membrane-damaging effects on bacteria. All these antimicrobial peptides are under early experimental or pre-clinical stages of development. It is therefore important to employ novel tools for the design and the development of new antibiotics from the untapped animal venoms of snake, scorpion, and spider for treating resistant pathogens. To date, snail venom toxins have shown little antibiotic potency against human pathogens. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The Discovery of a Potential Antimicrobial Agent: the Novel Compound Natural Medicinal Plant Fermentation Extracts against Candida albicans

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    Song, Mingzhu; Wang, Xirui; Mao, Canquan; Yao, Wei

    2018-01-01

    Natural medicinal plants and their extracts are important sources of antimicrobial drug development. In this study, we reported an ancient formula of Chinese folk medicine, the compound natural medicinal plant fermentation extracts (CNMPFE) for its antimicrobial effects. The effects and mechanisms of CNMPFE on C. albicans were studied by cell damage experiments including antimicrobial kinetics, fungal growth curve, alkaline phosphatase (AKP) activity, ultraviolet absorption, electric conductivity and the evaluation of cellular ultra microstructure. The results showed that the minimal inhibitory concentration and minimum fungicidal concentration of CNMPFE against C. albicans were 75% (vol/vol) and 80% (vol/vol) respectively. The inhibition of CNMPFE for C. albicans was dose and time dependent, based on increasing of the AKP activities and the ultraviolet absorptions and the electric conductivities of the fungal solutions, it may exert its antifungal properties by disrupting the structure of cell wall and the cell membrane integrity and their permeability, subsequently resulting in cell death. Taken together, these findings suggest that CNMPFE may be a promising drug candidate for the treatment of fungal infections skin diseases.

  9. Production of Antimicrobial Agent by Streptomyces violachromogenes

    International Nuclear Information System (INIS)

    Ahmed, Arwa A.

    2007-01-01

    The isolation of antibiotics from microorganisms improved the discovery of novel antibiotics, which is relatively easy as compared to chemical synthesis of antimicrobial agents. This study starts from isolation and purification of the antimicrobial producing Sterptomycetes obtained from soil habitat of Yemen. The good antimicrobial producing Sterptomycetes isolate was selected from a batch of Sterptomycetes isolates then identified. This isolate has bioactivity against some G+ve and G-ve bacteria. The antimicrobial agent isolated from Streptomyces violachromogenes (isolate no.YA118) was extracted with ethyl acetate at pH 3. The residue was applied to a silica gel column chromatography and eluted stepwise with many solvent systems. The active fractions were tested with B. subtilis NCTC10400. The purification of the antibiotic has been carried out by thin layer chromatography then the physical and chemical properties were studied to identify the antimicrobial agent. The isolated antimicrobial agent is an antibiotic belonging to the neomycin group. (author)

  10. Antimicrobial Agents Used in Endodontic Treatment

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    Marina George Kudiyirickal

    2008-01-01

    Full Text Available Biomechanical preparation alone does not completely eradicate microorganisms from the root canal, hence the next logical step is to perform root canal procedures in conjunction with antimicrobials. The use of an antimicrobial agent improves the efficacy and prognosis of endodontic treatment. This review enumerates the most widely used antimicrobial agents, their mechanism of action and their potential use in reducing the microbial load.

  11. Mechanisms of bacterial resistance to antimicrobial agents.

    NARCIS (Netherlands)

    van Duijkeren, Engeline; Schink, Anne-Kathrin; Roberts, Marilyn C; Wang, Yang; Schwarz, Stefan

    During the past decades resistance to virtually all antimicrobial agents has been observed in bacteria of animal origin. This chapter describes in detail the mechanisms so far encountered for the various classes of antimicrobial agents. The main mechanisms include enzymatic inactivation by either

  12. Antimicrobial activity of some Iranian medicinal plants

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    Ghasemi Pirbalouti Abdollah

    2010-01-01

    Full Text Available The major aim of this study was to determine the antimicrobial activity of the extracts of eight plant species which are endemic in Iran. The antimicrobial activities of the extracts of eight Iranian traditional plants, including Hypericum scabrum, Myrtus communis, Pistachia atlantica, Arnebia euchroma, Salvia hydrangea, Satureja bachtiarica, Thymus daenensis and Kelussia odoratissima, were investigated against Escherichia coli O157:H7, Bacillus cereus, Listeria monocytogenes and Candida albicans by agar disc diffusion and serial dilution assays. Most of the extracts showed a relatively high antimicrobial activity against all the tested bacteria and fungi. Of the plants studied, the most active extracts were those obtained from the essential oils of M. communis and T. daenensis. The MIC values for active extract and essential oil ranged between 0.039 and 10 mg/ml. It can be said that the extract and essential oil of some medicinal plants could be used as natural antimicrobial agents in food preservation. .

  13. Antimicrobial Peptides from Plants

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    James P. Tam

    2015-11-01

    Full Text Available Plant antimicrobial peptides (AMPs have evolved differently from AMPs from other life forms. They are generally rich in cysteine residues which form multiple disulfides. In turn, the disulfides cross-braced plant AMPs as cystine-rich peptides to confer them with extraordinary high chemical, thermal and proteolytic stability. The cystine-rich or commonly known as cysteine-rich peptides (CRPs of plant AMPs are classified into families based on their sequence similarity, cysteine motifs that determine their distinctive disulfide bond patterns and tertiary structure fold. Cystine-rich plant AMP families include thionins, defensins, hevein-like peptides, knottin-type peptides (linear and cyclic, lipid transfer proteins, α-hairpinin and snakins family. In addition, there are AMPs which are rich in other amino acids. The ability of plant AMPs to organize into specific families with conserved structural folds that enable sequence variation of non-Cys residues encased in the same scaffold within a particular family to play multiple functions. Furthermore, the ability of plant AMPs to tolerate hypervariable sequences using a conserved scaffold provides diversity to recognize different targets by varying the sequence of the non-cysteine residues. These properties bode well for developing plant AMPs as potential therapeutics and for protection of crops through transgenic methods. This review provides an overview of the major families of plant AMPs, including their structures, functions, and putative mechanisms.

  14. Ion Channels Induced by Antimicrobial Agents in Model Lipid Membranes are Modulated by Plant Polyphenols Through Surrounding Lipid Media.

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    Efimova, Svetlana S; Zakharova, Anastasiia A; Medvedev, Roman Ya; Ostroumova, Olga S

    2018-03-16

    The potential therapeutic applications of plant polyphenols in various neurological, cardiovascular, metabolic and malignant disorders determine the relevance of studying the molecular mechanisms of their action on the cell membranes. Here, the quantitative changes in the physical parameters of model bilayer lipid membranes upon the adsorption of plant polyphenols were evaluated. It was shown that butein and naringenin significantly decreased the intrinsic dipole potential of cholesterol-free and cholesterol-enriched membranes. Cardamonin, 4'-hydroxychalcone, licochalcone A and liquiritigenin demonstrated the average efficiency, while resveratrol did not characterized by the ability to modulate the bilayer electrostatics. At the same time, the tested polyphenols affected melting of phospholipids with saturated acyl chains. The effects were attributed to the lipid disordering and a promotion of the positive curvature stress. According to DSC data and results of measurements of the threshold voltages that cause bilayer breakdown licochalcone A is the most effective agent. Furthermore, the role of the polyphenol induced changes in the electric and elastic properties of lipid host in the regulation of reconstituted ion channels was examined. The ability of the tested polyphenols to decrease the conductance of single ion channels produced by the antifungal cyclic lipopeptide syringomycin E was in agreement with their effects on the dipole potential of the lipid bilayers. The greatest effect of licochalcone A on the steady-state membrane conductance induced by the antifungal polyene macrolide antibiotic nystatin correlated with its greatest efficacy to induce the positive curvature stress. We also found that butein and naringenin bind specifically to a single pore formed by α-hemolysin from Staphylococcus aureus.

  15. Antimicrobial activities of the essential oils of various plants against tomato late blight disease agent Phytophthora infestans.

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    Soylu, E Mine; Soylu, Soner; Kurt, Sener

    2006-02-01

    The aim of this study was to find an alternative to synthetic fungicides currently used in the control of devastating oomycete pathogen Phytophthora infestans, causal agent of late blight disease of tomato. Antifungal activities of essential oils obtained from aerial parts of aromatic plants such as oregano (Origanum syriacum var. bevanii), thyme (Thymbra spicata subsp. spicata), lavender (Lavandula stoechas subsp. stoechas), rosemary (Rosmarinus officinalis), fennel (Foeniculum vulgare), and laurel (Laurus nobilis), were investigated against P. infestans. Both contact and volatile phase effects of different concentrations of the essential oils used were determined by using two in vitro methods. Chemical compositions of the essential oils were also determined by GC-MS analysis. Major compounds found in essential oils of thyme, oregano, rosemary, lavender, fennel and laurel were carvacrol (37.9%), carvacrol (79.8), borneol (20.4%), camphor (20.2%), anethole (82.8%) and 1,8-cineole (35.5%), respectively. All essential oils were found to inhibit the growth of P. infestans in a dose-dependent manner. Volatile phase effect of oregano and thyme oils at 0.3 microg/ml air was found to completely inhibit the growth of P. infestans. Complete growth inhibition of pathogen by essential oil of fennel, rosemary, lavender and laurel was, however, observed at 0.4-2.0 microg/ml air concentrations. For the determination of the contact phase effects of the tested essential oils, oregano, thyme and fennel oils at 6.4 microg/ml were found to inhibit the growth of P. infestans completely. Essential oils of rosemary, lavender and laurel were inhibitory at relatively higher concentrations (12.8, 25.6, 51.2 microg/ml respectively). Volatile phase effects of essential oils were consistently found to be more effective on fungal growth than contact phase effect. Sporangial production was also inhibited by the essential oil tested. Light and scanning electron microscopic (SEM) observation on

  16. Plant-Derived Antimicrobials: Insights into Mitigation of Antimicrobial Resistance

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    Shun-Kai Yang

    2018-07-01

    Full Text Available Antibiotic resistance had first been reported not long after the discovery of the first antibiotic and has remained a major public health issue ever since. Challenges are constantly encountered during the mitigation process of antibiotic resistance in the clinical setting; especially with the emergence of the formidable superbug, a bacteria with multiple resistance towards different antibiotics; this resulted in the term multidrug resistant (MDR bacteria. This rapid evolution of the resistance phenomenon has propelled researchers to continuously uncover new antimicrobial agents in a bid to hopefully, downplay the rate of evolution despite a drying pipeline. Recently, there has been a paradigm shift in the mining of potential antimicrobials; in the past, targets for drug discovery were from microorganisms and at current, the focus has moved onto plants, this is mainly due to the beneficial attributes that plants are able to confer over that of microorganisms. This review will briefly discuss antibiotic resistance mechanisms employed by resistant bacteria followed by a detailed expository regarding the use of secondary metabolites from plants as a potential solution to the MDR pathogen. Finally, future prospects recommending enhancements to the usage of plant secondary metabolites to directly target antibiotic resistant pathogens will be discussed.

  17. Antimicrobial topical agents used in the vagina.

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    Frey Tirri, Brigitte

    2011-01-01

    Vaginally applied antimicrobial agents are widely used in the vagina in women with lower genital tract infections. An 'antimicrobial' is a general term that refers to a group of drugs that are effective against bacteria, fungi, viruses and protozoa. Topical treatments can be prescribed for a wide variety of vaginal infections. Many bacterial infections, such as bacterial vaginosis, desquamative inflammatory vaginitis or, as some European authors call it, aerobic vaginitis as well as infection with Staphylococcus aureus or group A streptococci, may be treated in this way. Candida vulvovaginitis is a fungal infection that is very amenable to topical treatment. The most common viral infections which can be treated with topical medications are condylomata acuminata and herpes simplex. The most often encountered protozoal vaginitis, which is caused by Trichomonas vaginalis, may be susceptible to topical medications, although this infection is treated systemically. This chapter covers the wide variety of commonly used topical antimicrobial agents for these diseases and focuses on the individual therapeutic agents and their clinical efficacy. In addition, potential difficulties that can occur in practice, as well as the usage of these medications in the special setting of pregnancy, are described in this chapter. Copyright © 2011 S. Karger AG, Basel.

  18. Insights on antimicrobial resistance, biofilms and the use of phytochemicals as new antimicrobial agents.

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    Borges, Anabela; Saavedra, Maria J; Simões, Manuel

    2015-01-01

    Antimicrobial resistance is one of the most serious public health problems. This is of particular concern when bacteria become resistant to various antimicrobial agents simultaneously and when they form biofilms. Consequently, therapeutic options for the treatment of infections have become limited, leading frequently to recurrent infections, treatment failure and increase of morbidity and mortality. Both, persistence and spread of antibiotic resistance, in combination with decreased effectiveness and increased toxicity of current antibiotics have emphasized the urgent need to search alternative sources of antimicrobial substances. Plants are recognized as a source of unexplored chemical structures with high therapeutic potential, including antimicrobial activity against clinically important microorganisms. Additionally, phytochemicals (plant secondary metabolites) present several advantages over synthetic molecules, including green status and different mechanisms of action from antibiotics which could help to overcome the resistance problem. In this study, an overview of the main classes of phytochemicals with antimicrobial properties and their mode of action is presented. A revision about the application of phytochemicals for biofilm prevention and control is also done. Moreover, the use of phytochemicals as scaffolds of new functional molecules to expand the antibiotics pipeline is reviewed.

  19. Macromolecular agents with antimicrobial potentialities: A drive to combat antimicrobial resistance.

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    Bilal, Muhammad; Rasheed, Tahir; Iqbal, Hafiz M N; Hu, Hongbo; Wang, Wei; Zhang, Xuehong

    2017-10-01

    In recent years, the antimicrobial resistance (AMR) or multidrug resistance (MDR) has become a serious health concern and major challenging issue, worldwide. After decades of negligence, the AMR has now captured global attention. The increasing number of antibiotic-resistant strains has threatened the achievements of science and medicine since it inactivates conventional antimicrobial therapeutics. Scientists are trying to respond to AMR/MDR threat by exploring innovative platforms and new therapeutic strategies to tackle infections from these resistant strains and bypass treatment limitations related to these pathologies. The present review focuses on the utilization of bio-inspired novel constructs and their potential applications as novel antimicrobial agents. The first part of the review describes plant-based biological macromolecules containing an immense variety of secondary metabolites, which could be potentially used as alternative strategies to combat antimicrobial resistance. The second part discusses the potential of metal-based macromolecules as effective antimicrobial platforms for preventing infections from resistant strains. The third part comprehensively elucidates how nanoparticles, in particular, metal-integrated nanoparticles can overcome this AMR or MDR issue. Towards the end, information is given with critical concluding remarks, gaps, and finally envisioned with future considerations. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Antimicrobial activity of Nigerian medicinal plants

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    Anyanwu, Madubuike Umunna; Okoye, Rosemary Chinazam

    2017-01-01

    Antimicrobial resistance (AMR) is currently one of the major threats facing mankind. The emergence and rapid spread of multi- and pan-drug-resistant organisms (such as vancomycin-, methicillin-, extended-spectrum β-lactam-, carbapenem- and colistin-resistant organisms) has put the world in a dilemma. The health and economic burden associated with AMR on a global scale are dreadful. Available antimicrobials have been misused and are almost ineffective with some of these drugs associated with dangerous side effects in some individuals. Development of new, effective, and safe antimicrobials is one of the ways by which AMR burden can be reduced. The rate at which microorganisms develop AMR mechanisms outpaces the rate at which new antimicrobials are being developed. Medicinal plants are potential sources of new antimicrobial molecules. There is renewed interest in antimicrobial activities of phytochemicals. Nigeria boasts of a huge heritage of medicinal plants and there is avalanche of researches that have been undertaken to screen antimicrobial activities of these plants. Scientific compilation of these studies could provide useful information on the antimicrobial properties of the plants. This information can be useful in the development of new antimicrobial drugs. This paper reviews antimicrobial researches that have been undertaken on Nigerian medicinal plants. PMID:28512606

  1. Prodigiosin - A Multifaceted Escherichia coli Antimicrobial Agent.

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    Tjaša Danevčič

    Full Text Available Despite a considerable interest in prodigiosin, the mechanism of its antibacterial activity is still poorly understood. In this work, Escherichia coli cells were treated with prodigiosin to determine its antimicrobial effect on bacterial physiology. The effect of prodigiosin was concentration dependent. In prodigiosin treated cells above MIC value no significant DNA damage or cytoplasmic membrane disintegration was observed. The outer membrane, however, becomes leaky. Cells had severely decreased respiration activity. In prodigiosin treated cells protein and RNA synthesis were inhibited, cells were elongated but could not divide. Pre-treatment with prodigiosin improved E. coli survival rate in media containing ampicillin, kanamycin and erythromycin but not phleomycin. The results suggest that prodigiosin acts as a bacteriostatic agent in E. coli cells. If prodigiosin was diluted, cells resumed growth. The results indicate that prodigiosin has distinct mode of antibacterial action in different bacteria.

  2. Antimicrobial effects of Indian medicinal plants against acne ...

    African Journals Online (AJOL)

    Propionibacterium acnes and Staphylococcus epidermidis have been recognized as pus-forming bacteria triggering an inflammation in acne. The present study was conducted to evaluate antimicrobial activities of Indian medicinal plants against these etiologic agents of acne vulgaris. Ethanolic extracts of Hemidesmus ...

  3. Antimicrobial peptides: Possible anti-infective agents.

    Science.gov (United States)

    Lakshmaiah Narayana, Jayaram; Chen, Jyh-Yih

    2015-10-01

    Multidrug-resistant bacterial, fungal, viral, and parasitic infections are major health threats. The Infectious Diseases Society of America has expressed concern on the decrease of pharmaceutical companies working on antibiotic research and development. However, small companies, along with academic research institutes, are stepping forward to develop novel therapeutic methods to overcome the present healthcare situation. Among the leading alternatives to current drugs are antimicrobial peptides (AMPs), which are abundantly distributed in nature. AMPs exhibit broad-spectrum activity against a wide variety of bacteria, fungi, viruses, and parasites, and even cancerous cells. They also show potential immunomodulatory properties, and are highly responsive to infectious agents and innate immuno-stimulatory molecules. In recent years, many AMPs have undergone or are undergoing clinical development, and a few are commercially available for topical and other applications. In this review, we outline selected anion and cationic AMPs which are at various stages of development, from preliminary analysis to clinical drug development. Moreover, we also consider current production methods and delivery tools for AMPs, which must be improved for the effective use of these agents. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Resistencia bacteriana Bacterial resistance to antimicrobial agents

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    Jesualdo Fuentes

    1993-01-01

    Full Text Available

    Se presenta un panorama de la resistencia bacteriana incluyendo su fisiopatogenia y formas de presentación y se establecen algunas consideraciones generales de tipo clínico como auxiliares para racionalizar el uso de los antimicrobianos y evitar o retardar el problema de la resistencia; éste plantea la necesidad de un reordenamiento definitivo en la prescripción de antimicrobianos. No será tanto la creación o descubrimiento de nuevos antibióticos sino la racionalización del manejo de los existentes lo que permitirá alcanzar victorias sobre estos microorganismos. Es Importante mantener educación continua sobre el uso adecuado de los antimicrobianos desde los puntos de vista epidemiológico, farmacocinético y fisiopatogénico.

    An overview on bacterial resistance to antimicrobial agents is presented. It includes the different genetic mechanisms for Its development and the biochemical phenomena that explain It. Some clinical considerations are proposed in order to rationalize the use of these drugs and to avoid or delay the appearance of resistance.

  5. Use of antimicrobial agents in aquaculture.

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    Park, Y H; Hwang, S Y; Hong, M K; Kwon, K H

    2012-04-01

    The aquaculture industry has grown dramatically, and plays an important role in the world's food supply chain. Antimicrobial resistance in bacteria associated with food animals receives much attention, and drug use in aquaculture is also an important issue. There are many differences between aquatic and terrestrial management systems, such as the methods used for administration of drugs. Unique problems are related to the application of drugs in aquatic environments. Residual drugs in fish products can affect people who consume them, and antimicrobials released into aquatic environments can select for resistant bacteria. Moreover, these antimicrobial-resistant bacteria, or their resistance genes, can be transferred to humans. To decrease the risks associated with the use of antimicrobials, various regulations have been developed. In addition, it is necessary to prevent bacterial diseases in aquatic animals by vaccination, to improve culture systems, and to monitor the amount of antimicrobial drugs used and the prevalence of antimicrobial-resistant bacteria.

  6. Bacteriophages show promise as antimicrobial agents.

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    Alisky, J; Iczkowski, K; Rapoport, A; Troitsky, N

    1998-01-01

    The emergence of antibiotic-resistant bacteria has prompted interest in alternatives to conventional drugs. One possible option is to use bacteriophages (phage) as antimicrobial agents. We have conducted a literature review of all Medline citations from 1966-1996 that dealt with the therapeutic use of phage. There were 27 papers from Poland, the Soviet Union, Britain and the U.S.A. The Polish and Soviets administered phage orally, topically or systemically to treat a wide variety of antibiotic-resistant pathogens in both adults and children. Infections included suppurative wound infections, gastroenteritis, sepsis, osteomyelitis, dermatitis, empyemas and pneumonia; pathogens included Staphylococcus, Streptococcus, Klebsiella, Escherichia, Proteus, Pseudomonas, Shigella and Salmonella spp. Overall, the Polish and Soviets reported success rates of 80-95% for phage therapy, with rare, reversible gastrointestinal or allergic side effects. However, efficacy of phage was determined almost exclusively by qualitative clinical assessment of patients, and details of dosages and clinical criteria were very sketchy. There were also six British reports describing controlled trials of phage in animal models (mice, guinea pigs and livestock), measuring survival rates and other objective criteria. All of the British studies raised phage against specific pathogens then used to create experimental infections. Demonstrable efficacy against Escherichia, Acinetobacter, Pseudomonas and Staphylococcus spp. was noted in these model systems. Two U.S. papers dealt with improving the bioavailability of phage. Phage is sequestered in the spleen and removed from circulation. This can be overcome by serial passage of phage through mice to isolate mutants that resist sequestration. In conclusion, bacteriophages may show promise for treating antibiotic resistant pathogens. To facilitate further progress, directions for future research are discussed and a directory of authors from the reviewed

  7. De-novo design of antimicrobial peptides for plant protection.

    Directory of Open Access Journals (Sweden)

    Benjamin Zeitler

    Full Text Available This work describes the de-novo design of peptides that inhibit a broad range of plant pathogens. Four structurally different groups of peptides were developed that differ in size and position of their charged and hydrophobic clusters and were assayed for their ability to inhibit bacterial growth and fungal spore germination. Several peptides are highly active at concentrations between 0,1 and 1 µg/ml against plant pathogenic bacteria, such as Pseudomonas syringae, Pectobacterium carotovorum, and Xanthomonas vesicatoria. Importantly, no hemolytic activity could be detected for these peptides at concentrations up to 200 µg/ml. Moreover, the peptides are also active after spraying on the plant surface demonstrating a possible way of application. In sum, our designed peptides represent new antimicrobial agents and with the increasing demand for antimicrobial compounds for production of "healthy" food, these peptides might serve as templates for novel antibacterial and antifungal agents.

  8. Human Health Consequences of Use of Antimicrobial Agents in Aquaculture

    DEFF Research Database (Denmark)

    Heuer, Ole Eske; Kruse, H.; Grave, K.

    2009-01-01

    industry in many regions of the world and the widespread, intensive, and often unregulated use of antimicrobial agents in this area of animal production, efforts are needed to prevent development and spread of antimicrobial resistance in aquaculture to reduce the risk to human health....... in aquaculture, several are classified by the World Health Organisation as critically important for use in humans. Occurrence of resistance to these antimicrobial agents in human pathogens severely limits the therapeutic options in human infections. Considering the rapid growth and importance of aquaculture...... gene transfer and reach human pathogens, or drug-resistant pathogens from the aquatic environment may reach humans directly. Horizontal gene transfer may occur in the aquaculture environment, in the food chain, or in the human intestinal tract. Among the antimicrobial agents commonly used...

  9. Pyridinium Oxime Compounds as Antimicrobial Agents

    National Research Council Canada - National Science Library

    Berger, Bradley J; Knodel, Marvin H

    2007-01-01

    ... (as a model for Leishmania spp.). In general, the compounds were found to have little to no antimicrobial effect, with KJD-2-11, a thiourea derivative, being the most active in all the test systems.

  10. Lipids and essential oils as antimicrobial agents

    National Research Council Canada - National Science Library

    Thormar, Halldor

    2011-01-01

    ... of Antimicrobial Lipids on Cell Membranes 20 1.7 Conclusions 21 Acknowledgements 21 References 22 2 Antibacterial Effects of Lipids: Historical Review (1881 to 1960) Halldor Thormar 2.1 Introduction 2....

  11. Computer-aided discovery of antimicrobial agents as potential enoyl ...

    African Journals Online (AJOL)

    Computer-aided discovery of antimicrobial agents as potential enoyl acyl carrier protein reductase inhibitors. ... Conclusion: Overall, the newly discovered hits can act as a good starting point in the future for the development of safe and potent antibacterial agents. Keywords: Enoyl acyl carrier protein reductase, saFabI, ...

  12. Predictive value of pharmacodynamic parameters of antimicrobial agents

    NARCIS (Netherlands)

    J.G. den Hollander (Jan)

    1999-01-01

    textabstractThe study of the phamlacodynamicg of antimicrobial agents has been a rapidly developing line of research in recent years. Regarding this line of research it is important to appreciate the difference between the pharmacokinetics and the phannacodynamics of phamlaceutical agents.

  13. The risk of some veterinary antimicrobial agents on public health associated with antimicrobial resistance and their molecular basis

    OpenAIRE

    Haihong Hao; Zahid Iqbal; Yulian Wang; Guyue Cheng; Zong-Hui Yuan

    2016-01-01

    The risk of antimicrobial agents used in food-producing animals on public health associated with antimicrobial resistance continues to be a current topic of discussion as related to animal and human public health. In the present review, resistance monitoring data and risk assessment result of some important antimicrobial agents were cited to elucidate the possible association of antimicrobial use in food animals and antimicrobial resistance in human. From the selected examples, it was obvious...

  14. Nanosilver: Potent antimicrobial agent and its biosynthesis

    African Journals Online (AJOL)

    VIKAS

    2014-01-22

    Jan 22, 2014 ... synthesis of silver nanoparticles, potential and the possible mechanism of antimicrobial actions. NANOSILVER SYNTHESIS- AN OVERVIEW. Nano silver are one of the promising products in the nanotechnology industry. The development of consistent processes for the synthesis of silver nanoparticles is an.

  15. The Use of Plant Antimicrobial Compounds for Food Preservation

    Science.gov (United States)

    Hintz, Tana; Matthews, Karl K.

    2015-01-01

    Foodborne disease is a global issue with significant impact on human health. With the growing consumer demand for natural preservatives to replace chemical compounds, plant antimicrobial compounds must be thoroughly investigated for their potential to serve as biopreservatives. This review paper will focus on the plant-derived products as antimicrobial agents for use in food preservation and to control foodborne pathogens in foods. Structure, modes of action, stability, and resistance to these plant compounds will be discussed as well as their application in food industries and possible technologies by which they can be delivered. Benefits as well as challenges, such as the need for further research for implementation and governmental regulation, will be highlighted. PMID:26539472

  16. Mushrooms as Possible Antioxidant and Antimicrobial Agents

    Science.gov (United States)

    Kosanić, Marijana; Ranković, Branislav; Dašić, Marko

    2012-01-01

    The aim of the study is to examine in-vitro antioxidant and antimicrobial activity of the acetonic and methanolic extracts of the mushrooms Boletus aestivalis, Boletus edulis and Leccinum carpini. Antioxidant activity was evaluated by using free radical scavenging activity and reducing power. In addition, total content of phenol and flavonoid in extracts were determined as pyrocatechol equivalent, and as rutin equivalent, respectively. As a result of the study acetonic extracts from Boletus edulis was more powerful antioxidant activity with IC50 value of 4.72 μg/mL which was similar or greater than the standard antioxidants, ascorbic acid (IC50 = 4.22 μg/mL), BHA (IC50 = 6.42 μg/mL) and α-tocopherol (IC50 = 62.43 μg/mL). Moreover, the tested extracts had effective reducing power. A significant relationship between total phenolic and flavonoid contents and their antioxidative activities was significantly observed. The antimicrobial activity of each extract was estimated by determination of the minimum inhibitory concentration by using microdilution plate method against five species of bacteria and five species of fungi. Generally, the tested mushroom extracts had relatively strong antimicrobial activity against the tested microorganisms. The minimum inhibitory concentration for both extracts related to the tested bacteria and fungi were 1.25 - 10 mg/ mL. The present study shows that tested mushroom species demonstrated a strong antioxidant and antimicrobial activity. It suggests that mushroom may be used as good sources of natural antioxidants and for pharmaceutical purposes in treating of various deseases. PMID:24250542

  17. The In Vitro Antimicrobial Effects of Lavandula angustifolia Essential Oil in Combination with Conventional Antimicrobial Agents

    Science.gov (United States)

    de Rapper, Stephanie; Viljoen, Alvaro

    2016-01-01

    The paper focuses on the in vitro antimicrobial activity of Lavandula angustifolia Mill. (lavender) essential oil in combination with four commercial antimicrobial agents. Stock solutions of chloramphenicol, ciprofloxacin, nystatin, and fusidic acid were tested in combination with L. angustifolia essential oil. The antimicrobial activities of the combinations were investigated against the Gram-positive bacterial strain Staphylococcus aureus (ATCC 6538) and Gram-negative Pseudomonas aeruginosa (ATCC 27858) and Candida albicans (ATCC 10231) was selected to represent the yeasts. The antimicrobial effect was performed using the minimum inhibitory concentration (MIC) microdilution assay. Isobolograms were constructed for varying ratios. The most prominent interaction was noted when L. angustifolia essential oil was combined with chloramphenicol and tested against the pathogen P. aeruginosa (ΣFIC of 0.29). Lavendula angustifolia essential oil was shown in most cases to interact synergistically with conventional antimicrobials when combined in ratios where higher volumes of L. angustifolia essential oil were incorporated into the combination. PMID:27891157

  18. The In Vitro Antimicrobial Effects of Lavandula angustifolia Essential Oil in Combination with Conventional Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Stephanie de Rapper

    2016-01-01

    Full Text Available The paper focuses on the in vitro antimicrobial activity of Lavandula angustifolia Mill. (lavender essential oil in combination with four commercial antimicrobial agents. Stock solutions of chloramphenicol, ciprofloxacin, nystatin, and fusidic acid were tested in combination with L. angustifolia essential oil. The antimicrobial activities of the combinations were investigated against the Gram-positive bacterial strain Staphylococcus aureus (ATCC 6538 and Gram-negative Pseudomonas aeruginosa (ATCC 27858 and Candida albicans (ATCC 10231 was selected to represent the yeasts. The antimicrobial effect was performed using the minimum inhibitory concentration (MIC microdilution assay. Isobolograms were constructed for varying ratios. The most prominent interaction was noted when L. angustifolia essential oil was combined with chloramphenicol and tested against the pathogen P. aeruginosa (ΣFIC of 0.29. Lavendula angustifolia essential oil was shown in most cases to interact synergistically with conventional antimicrobials when combined in ratios where higher volumes of L. angustifolia essential oil were incorporated into the combination.

  19. Pharmacological interactions of anti-microbial agents in odontology.

    Science.gov (United States)

    Gómez-Moreno, Gerardo; Guardia, Javier; Cutando, Antonio; Calvo-Guirado, José-Luis

    2009-03-01

    In this third article we describe the pharmacological interactions resulting from the use of anti-microbial agents. Although the antimicrobials prescribed in odontology are generally safe they can produce interactions with other medicaments which can give rise to serious adverse reactions which are well documented in clinical studies. Antibiotics with grave and dangerous life threatening consequences are erythromycin, clarithromycin and metronidazol and the anti-fungal agents are ketoconazol and itraconazol. Regarding the capacity of the anti-microbials to reduce the efficacy of oral anti-contraceptives the clinical studies to date are inconclusive, however, it would be prudent for the oral cavity specialist to point out the risk of a possible interaction. Therefore the specialist should be aware of possible interactions as a consequence of administering an antibiotic together with other medicaments the patient may be taking.

  20. In vitro susceptibilities of zygomycetes to combinations of antimicrobial agents.

    NARCIS (Netherlands)

    Danaoui, E.; Afeltra, J.; Meis, J.F.G.M.; Verweij, P.E.

    2002-01-01

    Combinations of antimicrobial agents were tested against 35 strains of zygomycetes. The interaction between amphotericin B and rifampin was synergistic or additive. Flucytosine alone was inactive and, upon combination with amphotericin B, synergy was not achieved. The combination of amphotericin B

  1. Resistance of Streptococcus sanguis biofilms to antimicrobial agents

    DEFF Research Database (Denmark)

    Larsen, T; Fiehn, N E

    1996-01-01

    of Streptococcus sanguis 804 and ATCC 10556 to amoxicillin, doxycycline and chlorhexidine was determined by a broth dilution method. Subsequently, S. sanguis biofilms established in an in vitro flow model were perfused with the antimicrobial agents for 48 h at concentrations equal to and up to 500 times the MIC...

  2. Chemerin is an antimicrobial agent in human epidermis.

    Directory of Open Access Journals (Sweden)

    Magdalena Banas

    Full Text Available Chemerin, a chemoattractant ligand for chemokine-like receptor 1 (CMKLR1 is predicted to share similar tertiary structure with antibacterial cathelicidins. Recombinant chemerin has antimicrobial activity. Here we show that endogenous chemerin is abundant in human epidermis, and that inhibition of bacteria growth by exudates from organ cultures of primary human skin keratinocytes is largely chemerin-dependent. Using a panel of overlapping chemerin-derived synthetic peptides, we demonstrate that the antibacterial activity of chemerin is primarily mediated by Val(66-Pro(85, which causes direct bacterial lysis. Therefore, chemerin is an antimicrobial agent in human skin.

  3. Synthesis and Evaluation of Some Coumarin Containing Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Sayali D. Kudale

    2012-01-01

    Full Text Available A series of the Schiff’s bases incorporating coumarin and chalcone moeities, 3-(4-(4-(substituted phenylprop-1-ene-3-one phenylimino methyl-4-chloro-2h-chromen-2-one 4(a-g were synthesized as potential antimicrobial agents. These compounds were characterized on the basis of their spectral (IR, 1H NMR data and evaluated for antimicrobial activity in vitro against gram positive and gram negative bacteria and fungi. Compound 4b was found to be most active with an MIC of 20 µg/mL against all the tested organisms.

  4. Antimicrobial properties of Honduran medicinal plants.

    Science.gov (United States)

    Lentz, D L; Clark, A M; Hufford, C D; Meurer-Grimes, B; Passreiter, C M; Cordero, J; Ibrahimi, O; Okunade, A L

    1998-12-01

    Ninety-two plants used in the traditional pharmacopoeia of the Pech and neighboring Mestizo peoples of central Honduras are reported. The results of in vitro antimicrobial screens showed that 19 of the extracts from medicinal plants revealed signs of antifungal activity while 22 demonstrated a measurable inhibitory effect on one or more bacterial cultures. Bioassay-guided fractionation of extracts from Mikania micrantha, Neurolaena lobata and Piper aduncum produced weak to moderately active isolates. The broad spectrum of activity of the extracts helps to explain the widespread use of these plants for wound healing and other applications.

  5. Review of new insights into antimicrobial agents.

    Science.gov (United States)

    Dehghan Esmatabadi, M J; Bozorgmehr, A; Hajjari, S N; Sadat Sombolestani, A; Malekshahi, Z V; Sadeghizadeh, M

    2017-02-28

    People have known the bacteria and have used various ways to deal with them, from a long time ago. Perhaps, natural antibiotics with have been the first step in fighting against pathogens. However, several factors, such as dealing with unfamiliar bacteria or emergence of drug-resistant species, have motivated us to discover new antibiotics or  even change previous types. In this regard, a variety of natural and synthetic antibiotics with different origins, mechanism of action, structures and functional spectrum, have been developed and used. Some impact on the synthesis of nucleic acids and some affect protein synthesis so destroy bacteria. There is a ring in the structure of most of the antibiotics which gives them special properties. However, despite their numerous advantages, antibiotics also have drawbacks ehich limit their use in all situations. Therefore, other approaches such as photodynamic therapy (PDT) and antibacterial peptides were considered as alternatives. Photodynamic therapy (PDT) is a treatment that uses photosensitizing agents, along with light, to kill bacteria. The photosensitizing agents only work after they have been activated by certain kinds of light. Antibacterial peptides are a unique and diverse group of molecules which have  between 12 and 50 amino acids in general.  In this paper, will reviewt hree mentioned topics, namely antibiotics, photodynamic therapy and antibacterial peptides and will discuss the advantages and disadvantages of each approach briefly.

  6. Current and future challenges in the development of antimicrobial agents.

    Science.gov (United States)

    Rennie, Robert P

    2012-01-01

    Micro-organisms exist to survive. Even in the absence of antimicrobial agents, many have determinants of resistance that may be expressed phenotypically, should the need arise. With the advent of the antibiotic age, as more and more drugs were developed to treat serious infections, micro-organisms (particularly bacteria) rapidly developed resistance determinants to prevent their own demise.The most important determinants of resistance have been in the Gram-positive and Gram-negative bacteria. Among Gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and penicillin-resistant Streptococcus pneumoniae (PRSP) have taxed researchers and pharmaceutical companies to develop new agents that are effective against these resistant strains. Among the Gram-negative bacteria, extended-spectrum beta-lactamase (ESBL) enzymes, carbapenemases (CREs) and the so-called amp-C enzymes that may be readily transferred between species of enterobacteriaceae and other facultative species have created multi-drug resistant organisms that are difficult to treat. Other resistance determinants have been seen in other clinically important bacterial species such as Neisseria gonorrhoeae, Clostridium difficile, Haemophilus influenzae and Mycobacterium tuberculosis. These issues have now spread to fungal agents of infection.A variety of modalities have been used to stem the tide of resistance. These include the development of niche compounds that target specific resistance determinants. Other approaches have been to find new targets for antimicrobial activity, use of combination agents that are effective against more than one target in the cell, or new delivery mechanism to maximize the concentration of antimicrobial agents at the site of infection without causing toxicity to the host. It is important that such new modalities have been proved effective for clinical therapy. Animal models and non-mammalian systems have been developed to

  7. Essential oils as natural food antimicrobial agents: a review.

    Science.gov (United States)

    Vergis, Jess; Gokulakrishnan, P; Agarwal, R K; Kumar, Ashok

    2015-01-01

    Food-borne illnesses pose a real scourge in the present scenario as the consumerism of packaged food has increased to a great extend. Pathogens entering the packaged foods may survive longer, which needs a check. Antimicrobial agents either alone or in combination are added to the food or packaging materials for this purpose. Exploiting the antimicrobial property, essential oils are considered as a "natural" remedy to this problem other than its flavoring property instead of using synthetic agents. The essential oils are well known for its antibacterial, antiviral, antimycotic, antiparasitic, and antioxidant properties due to the presence of phenolic functional group. Gram-positive organisms are found more susceptible to the action of the essential oils. Essential oils improve the shelf-life of packaged products, control the microbial growth, and unriddle the consumer concerns regarding the use of chemical preservatives. This review is intended to provide an overview of the essential oils and their role as natural antimicrobial agents in the food industry.

  8. Biologically Active and Antimicrobial Peptides from Plants

    Science.gov (United States)

    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

  9. Biologically Active and Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    Carlos E. Salas

    2015-01-01

    Full Text Available 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.

  10. Antityrosinase and antimicrobial activities from Thai medicinal plants.

    Science.gov (United States)

    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.

  11. Antimicrobial screening of ethnobotanically important stem bark of medicinal plants.

    Science.gov (United States)

    Singh, Meenakshi; Khatoon, Sayyada; Singh, Shweta; Kumar, Vivek; Rawat, Ajay Kumar Singh; Mehrotra, Shanta

    2010-07-01

    The stem barks are the rich sources of tannins and other phenolic compounds. Tannins inhibited the growth of various fungi, yeast, bacteria and virus. Hence, ten stem barks of ethnomedicinally important plants were screened for antibacterial and antifungal activities against human pathogenic strains. Air-dried and powdered stem bark of each plant was extracted with 50% aqueous ethanol, lyophilized and the dried crude extracts were used for the screening against 11 bacteria and 8 fungi. Antibacterial and antifungal activities were performed according to microdilution methods by NCCLS. The plants Prosopis chilensis, Pithecellobium dulce, Mangifera indica showed significant antibacterial and antifungal activities against Streptococcus pneumonia, Enterobacter aerogenes, Klebsiella pneumonia and Candida albicans with MIC of 0.08mg/ml. Pithecellobium dulce bark also showed significant antibacterial activity against Bacillus cereus. The bark of Pithecellobium dulce has more or less similar activity against the known antibiotic and may be considered as potent antimicrobial agent for various infectious diseases.

  12. Susceptibility of Haemophilus equigenitalis, the causal agent of contagious equine metritis, to 31 antimicrobial agents.

    Science.gov (United States)

    Sugimoto, C; Isayama, Y; Kashiwazaki, M; Mitani, K

    1981-01-01

    The minimal inhibitory concentrations of 31 antimicrobial agents were determined for 99 isolates of Haemophilus equigenitalis by the agar dilution method. All the isolates showed good susceptibility to 26 antimicrobial agents tests, minimal inhibitory concentrations of which were less than 3.13 micrograms/ml for more than 90% of the isolates. Of these agents, 4 macrolides (erythromycin, oleandomycin, kitasamycin, tylosin), 3 tetracyclines (tetracycline, chlortetracycline, oxytetracycline), 1 peptide (colistin), 1 penicillin (ampicillin) and 1 pleuromutilin (tiamulin) were the most active agents, showing a minimal inhibitory concentration of less than 0.39 micrograms/ml for more than 90% of the isolates. The growth of more than 90% of the isolates was not inhibited by 800 micrograms/ml of streptomycin.

  13. Antimicrobial nature and use of some medicinal plants in Nigeria ...

    African Journals Online (AJOL)

    Forty eight medicinal plants in Nigeria were screened for their antimicrobial activity. Twenty three (47.91%) of the plants caused over 70% mortality of the test organism which include anopheline and culicine larva. Bacillus spp. and Escherichia coli were shown to be susceptible to the antimicrobial activity of some plants.

  14. NATURAL ANTIMICROBIAL AGENT USE IN THE PRESERVATION OF FRUITS AND VEGETABLES

    Directory of Open Access Journals (Sweden)

    Elvia Nereyda Rodríguez Sauceda

    2011-01-01

    Full Text Available Today has been a need to find alternatives of conservation, because it has been associated with consumption of poison chemical preservatives. The demand for minimally processed fresh products is increasing, and interest in natural antimicrobial agents (derived from plants, so now looking for the combination of two or more factors that interact additively or synergistically controlling population microbial, allowing it to fresh produce similar products with less additives, it should be noted that the rate of microbial spoilage depends not only on microorganisms but also the chemical combination of product and type of initial microbial load. That is why the main aim of food processing is to provide comfort to humans through a safe, nutritionally adequate and meet the expectations of taste, aroma and appearance, so the use of natural food additives involves the isolation, purification, stabilization and incorporation of these compounds to food antimicrobial purposes, without adversely affecting the sensory characteristics. In general, every time we discover more plants or parts thereof which contain natural antimicrobials, such as including phenolic compounds from bark, stems, leaves, flowers, organic acids present in fruits and phytoalexins produced in plants, so as will not only safer, but better food quality and type of antimicrobials that are regarded as potentially safer sources.

  15. Electrospun Nanofibres Containing Antimicrobial Plant Extracts

    Directory of Open Access Journals (Sweden)

    Wanwei Zhang

    2017-02-01

    Full Text Available Over the last 10 years great research interest has been directed toward nanofibrous architectures produced by electrospinning bioactive plant extracts. The resulting structures possess antimicrobial, anti-inflammatory, and anti-oxidant activity, which are attractive for biomedical applications and food industry. This review describes the diverse approaches that have been developed to produce electrospun nanofibres that are able to deliver naturally-derived chemical compounds in a controlled way and to prevent their degradation. The efficacy of those composite nanofibres as wound dressings, scaffolds for tissue engineering, and active food packaging systems will be discussed.

  16. Retainment of the antimicrobial agent triclosan in a septic tank

    DEFF Research Database (Denmark)

    Kirjanova, Ala; Rimeika, Mindaugas; Vollertsen, Jes

    2014-01-01

    Laboratory experiments were conducted to investigate the fate of the antimicrobial agent triclosan (TCS) in a conventional septic tank. The main mechanism of TCS removal from wastewater was identified to be rapid TCS sorption to suspended particles followed by settling of these particles...... to the bottom of the septic tank. Sorption to particles was completed within minutes while the settling took several days. Therefore, in a septic tank the removal of TCS from wastewater is mainly determined by the removal of suspended particles by sedimentation. Over 5 days of hydraulic residence time...... subsequent sorption onto the septic sludge....

  17. Aqueous Zinc Compounds as Residual Antimicrobial Agents for Textiles.

    Science.gov (United States)

    Holt, Brandon Alexander; Gregory, Shawn Alan; Sulchek, Todd; Yee, Shannon; Losego, Mark D

    2018-03-07

    Textiles, especially those worn by patients and medical professionals, serve as vectors for proliferating pathogens. Upstream manufacturing techniques and end-user practices, such as transition-metal embedment in textile fibers or alcohol-based disinfectants, can mitigate pathogen growth, but both techniques have their shortcomings. Fiber embedment requires complete replacement of all fabrics in a facility, and the effects of embedded nanoparticles on human health remain unknown. Alcohol-based, end-user disinfectants are short-lived because they quickly volatilize. In this work, common zinc salts are explored as an end-user residual antimicrobial agent. Zinc salts show cost-effective and long-lasting antimicrobial efficacy when solution-deposited on common textiles, such as nylon, polyester, and cotton. Unlike common alcohol-based disinfectants, these zinc salt-treated textiles mitigate microbial growth for more than 30 days and withstand commercial drying. Polyester fabrics treated with ZnO and ZnCl 2 were further explored because of their commercial ubiquity and likelihood for rapid commercialization. ZnCl 2 -treated textiles were found to retain their antimicrobial coating through abrasive testing, whereas ZnO-treated textiles did not. Scanning electron microscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry analyses suggest that ZnCl 2 likely hydrolyzes and reacts with portions of the polyester fiber, chemically attaching to the fiber, whereas colloidal ZnO simply sediments and binds with weaker physical interactions.

  18. An Investigation on the antimicrobial activity of some endemic plant ...

    African Journals Online (AJOL)

    SERVER

    2008-01-04

    Jan 4, 2008 ... Key words: Antimicrobial activity, endemic plants, plant extract. INTRODUCTION ..... The essential oil of A. balsamea was found to be inactive against E. ... Origanum solymicum and Origanum bilgeri from Turkey. Afr. J. Trad.

  19. Antibiofilm agents: A new perspective for antimicrobial strategy.

    Science.gov (United States)

    Li, Xi-Hui; Lee, Joon-Hee

    2017-10-01

    Biofilms are complex microbial architectures that attach to surfaces and encase microorganisms in a matrix composed of self-produced hydrated extracellular polymeric substances (EPSs). In biofilms, microorganisms become much more resistant to antimicrobial treatments, harsh environmental conditions, and host immunity. Biofilm formation by microbial pathogens greatly enhances survival in hosts and causes chronic infections that result in persistent inflammation and tissue damages. Currently, it is believed over 80% of chronic infectious diseases are mediated by biofilms, and it is known that conventional antibiotic medications are inadequate at eradicating these biofilm-mediated infections. This situation demands new strategies for biofilm-associated infections, and currently, researchers focus on the development of antibiofilm agents that are specific to biofilms, but are nontoxic, because it is believed that this prevents the development of drug resistance. Here, we review the most promising antibiofilm agents undergoing intensive research and development.

  20. Bioactive and wood-associated stilbenes as multifunctional antimicrobial and health promoting agents - BIOSTIMUL

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A. von (Univ. of Eastern Finland, Kuopio (Finland). Dept. of Biosciences.), Email: atte.vonWright@uef.fi

    2010-10-15

    Plant polyphenolics have a wide range of bioactivities. Coniferous trees are a rich source of stilbenes, such as pinosylvin in the genus Pinus. Pinosylvin is structurally very similar to resveratrol, a stilbene found in grapes and red berries, and which is reported to have beneficial health effects such as prevention of cardiovascular diseases, tumourigenesis, and according to recent findings, also type II diabetes. In our previous studies the bioactivities of pinosylvin (antimicrobial effects and cytotoxic activities against cancer cells) were very similar to those of resveratrol. In this project we elucidate the potential of pinosylvin and its derivatives in food applications as multifunctional antimicrobial agents with positive health effects (including prevention of type II diabetes) highlighting results. (orig.)

  1. Bioactive and wood-associated stilbenes as multifunctional antimicrobial and health promoting agents - BIOSTIMUL

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A. von (Univ. of Kuopio, Dept. of Biosciences (Finland)), email: atte.vonWright@uku.fi

    2009-10-15

    Plant polyphenolics have a wide range of bioactivities. Coniferous trees are a rich source of stilbenes, such as pinosylvin in the genus Pinus. Pinosylvin is structurally very similar to resveratrol, a stilbene found in grapes and red berries, and which is reported to have beneficial health effects such as prevention of cardiovascular diseases, tumourigenesis, and according to recent findings, also type 2 diabetes. In our previous studies the bioactivities of pinosylvin (antimicrobial effects and cytotoxic activities against cancer cells) were very similar to those of resveratrol. In this project we elucidate the potential of pinosylvin and its derivatives in food applications as multifunctional antimicrobial agents with positive health effects (including prevention of type 2 diabetes) highlighting results. (orig.)

  2. Bioactive and wood-associated stilbenes as multifunctional antimicrobial and health promoting agents (BIOSTIMUL)

    Energy Technology Data Exchange (ETDEWEB)

    Wright, A. von (Kuopio Univ., Department of Biosciences (Finland))

    2008-07-01

    Plant polyphenolics have a wide range of bioactivities. Coniferous trees are a rich source of stilbenes, such as pinosylvin in the genus Pinus. Pinosylvin is structurally very similar to resveratrol, a stilbene found in grapes and red berries, and which is reported to have beneficial health effects such as prevention of cardiovascular diseases, tumourigenesis, and according to recent findings, also type II diabetes. In our previous studies the bioactivities of pinosylvin (antimicrobial effects and cytotoxic activities against cancer cells) were very similar to those of resveratrol. In this project we elucidate the potential of pinosylvin and as derivatives in food applications as multifunctional antimicrobial agents with positive health effects (including prevention of type II diabetes) highlighting results. (orig.)

  3. Antimicrobial activity of four plants from Peruvian north-east

    OpenAIRE

    Ruiz Q., Julio R.; Roque A., Mirtha

    2014-01-01

    The present work investigated the in vitro antimicrobial activities of ethanolic, methonolic and hydroalcoholic extracts corresponding to four plants of north easter of Peru; Cassia reticulata (whole plant), Ilex guayusa Loes (leaves), Piper lineatum (leaves), y Terminalia catappa (leaves). The plants were collected in the department of Cajamarca, except Terminalia catappa (Amazonas). The antimicrobial activity was determinated by the method of agar diffusion. The used microorganisms were the...

  4. Synergy between antibiotics and natural agents results in increased antimicrobial activity against Staphylococcus epidermidis.

    Science.gov (United States)

    Abidi, Syed Hani; Ahmed, Khalid; Sherwani, Sikander Khan; Kazmi, Shahana Urooj

    2015-09-27

    Staphylococcus epidermidis is one of the most frequent causes of biofilm-associated infections on indwelling medical devices. With the emergence of methicillin-resistant S. epidermidis (MRSE), there is an urgent need to discover novel active agents against a range of Gram-positive pathogens. We screened the clinical isolates of S. epidermidis for susceptibility/resistance against commonly prescribed antibiotics. Furthermore, we tested some natural agents alone and in combination with antibiotics to find possible synergistic antimicrobial effects. S. epidermidis clinical isolates were screened for susceptibility/resistance against vancomycin, erythromycin, tetracycline, chloramphenicol, ampicillin, ofloxacin, cephalexin, and gentamicin using the Kirby-Bauer disk diffusion method. The antimicrobial potential of Camellia sinensis, Juglans regia, and Hippophae rhamnoides alone and in combination with antibiotics were examined using the disk diffusion method, where the antimicrobial potential activity was measured in terms of formation of zones of inhibition. Most S. epidermidis isolates were found to be resistant to one or more antibiotics. Gentamycin and ofloxacin were found to be the most effective antibiotics against S. epidermidis isolates. Extracts of Hippophae rhamnoides, Juglans regia, and Camellia sinensis were found to be equally effective against S. epidermidis isolates. In combination with antibiotics, these extracts exhibited appreciable synergistic activity; the highest synergistic activity was observed with erythromycin and cephalexin. In the case of cephalexin, a reversion in resistance was observed. The plant extracts used in the study exhibited additive and synergistic antibacterial activity against S. epidermidis, hence providing an effective alternative to deal with the problem of multidrug resistance.

  5. Oxygen tension during biofilm growth influences the efficacy antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Raquel Pippi ANTONIAZZI

    Full Text Available Abstract Objective To compare the antimicrobial efficacy of a 0.12% chlorhexidine (CHX and herbal green tea (Camellia sinensis solution on established biofilms formed at different oxygen tensions in an in situ model. Method Twenty-five dental students were eligible for the study. In situ devices with standardized enamel specimens (ES facing the palatal and buccal sides were inserted in the mouths of volunteers for a 7 day period. No agent was applied during the first four days. From the fifth day onward, both agents were applied to the test ES group and no agent was applied to the control ES group. After 7 days the ES fragments were removed from the devices, sonicated, plated on agar, and incubated for 24 h at 37 °C to determine and quantify the colony forming units (CFUs. Result CHX had significantly higher efficacy compared to green tea on the buccal (1330 vs. 2170 CFU/µL and palatal (2250 vs. 2520 CFU/µL ES. In addition, intragroup comparisons showed significantly higher efficacy in buccal ES over palatal ES (1330 vs. 2250 CFU/µL for CHX and 2170 vs, 2520 CFU/µL for CV for both solutions. Analysis of the ES controls showed significantly higher biofilm formation in palatal ES compared to buccal ES. Conclusion CHX has higher efficacy than green tea on 4-day biofilms. The efficacy of both agents was reduced for biofilms grown in a low oxygen tension environment. Therefore, the oxygen tension environment seems to influence the efficacy of the tested agents.

  6. [Susceptibility and resistence of Pseudomonas aeruginosa to antimicrobial agents].

    Science.gov (United States)

    Gamero Delgado, M C; García-Mayorgas, A D; Rodríguez, F; Ibarra, A; Casal, M

    2007-06-01

    Pseudomonas aeruginosa is an opportunistic microorganism that is frequently the cause of nosocomial infections. Multiple mechanisms are involved in its natural and acquired resistance to many of the antimicrobial agents commonly used in clinical practice. The objective of this study was to assess the susceptibility and resistance patterns of P. aeruginosa strains isolated in Hospital Reina Sofia between 2000 and 2005, as well as to analyze the differences between intrahospital and extrahospital isolates in 2005 and to compare the results with those obtained in other studies. A total of 3,019 strains of P. aeruginosa from different hospitals and nonhospital settings were evaluated, taking into consideration their degree of sensitivity to different antibiotics. The MICs were determined by means of the Wider I automated system (Soria Melguizo), taking into consideration the criteria of susceptibility and resistance recommended by MENSURA. Results of the analysis showed that P. aeruginosa maintained similar levels of antimicrobial susceptibility during the period 2000-2005, with increased susceptibility to amikacin, gentamicin and tobramycin. There were also important differences in the degree of susceptibility between intrahospital and extrahospital strains, except for imipenem and fosfomycin. The intrahospital difference in susceptibility was also evaluated, emphasizing the importance of periodically studying susceptibility and resistance patterns of P. aeruginosa in each setting in order to evaluate different therapeutic guidelines, as it is not always advisable to extrapolate data from different regions. These differences can be explained by the different use of antibiotics in each center and the geographic variations of the resistance mechanisms of P. aeruginosa.

  7. Retainment of the antimicrobial agent triclosan in a septic tank.

    Science.gov (United States)

    Kirjanova, Ala; Rimeika, Mindaugas; Vollertsen, Jes; Nielsen, Asbjørn Haaning

    2014-01-01

    Laboratory experiments were conducted to investigate the fate of the antimicrobial agent triclosan (TCS) in a conventional septic tank. The main mechanism of TCS removal from wastewater was identified to be rapid TCS sorption to suspended particles followed by settling of these particles to the bottom of the septic tank. Sorption to particles was completed within minutes while the settling took several days. Therefore, in a septic tank the removal of TCS from wastewater is mainly determined by the removal of suspended particles by sedimentation. Over 5 days of hydraulic residence time the initial dissolved TCS concentration of 100 μg L(-1) was reduced by 87 ± 8%. During the first 24 hours, 66-86% of all removed TCS was retained, whereas during the remainder of the experiment a slight but steady decrease in TCS concentration was observed. This was most likely caused by TCS diffusion and its subsequent sorption onto the septic sludge.

  8. Antimicrobial Peptides: An Emerging Category of Therapeutic Agents.

    Science.gov (United States)

    Mahlapuu, Margit; Håkansson, Joakim; Ringstad, Lovisa; Björn, Camilla

    2016-01-01

    Antimicrobial peptides (AMPs), also known as host defense peptides, are short and generally positively charged peptides found in a wide variety of life forms from microorganisms to humans. Most AMPs have the ability to kill microbial pathogens directly, whereas others act indirectly by modulating the host defense systems. Against a background of rapidly increasing resistance development to conventional antibiotics all over the world, efforts to bring AMPs into clinical use are accelerating. Several AMPs are currently being evaluated in clinical trials as novel anti-infectives, but also as new pharmacological agents to modulate the immune response, promote wound healing, and prevent post-surgical adhesions. In this review, we provide an overview of the biological role, classification, and mode of action of AMPs, discuss the opportunities and challenges to develop these peptides for clinical applications, and review the innovative formulation strategies for application of AMPs.

  9. THE STUDY THE EFFICACY AND SAFETY OF ANTIMICROBIAL AGENTS

    Directory of Open Access Journals (Sweden)

    V. V. Bagaeva

    2015-01-01

    Full Text Available Abstract:Effective treatment of patients with infectious and inflammatory diseases of the skin and mucous membranes often involves the use of antimicrobial agents.The purpose of the study was an in vitro estimation of cytotoxicity and the efficiency of national resources for local use: gel with bacteriophages («Otofag», «Fagogin», «Fagoderm», «Fagodent» and antiseptic — «Сhlorhexidine» and «Miramistin».Materials and Methods. To study the effectiveness of antimicrobial agents they used to provide crop strains of Staphylococcus aureus and Streptococcus pyogenes as one of the most common representatives of pathogens. The study of cell viability and cytotoxicity antimicrobials performed on cell lines KB — epidermoid carcinoma of the oral cavity of a human. For this purpose we use mikrotetrazoly test, which is widely used in the assessment of the effects on the cells of toxins, pharmaceuticals, adverse environmental factors, allowing to evaluate the toxicity of investigational drugs in vitro.The results showed that the efficacy against pathogens Staphylococcus aureus and Streptococcus pyogenes, has even a 10‑fold dilution of «Сhlorhexidine» 0.05% and gels with bacteriophages. Antiseptic «Miramistin» is effective only on the initial concentration. The study of cytotoxicity showed that the processing of epidermoid carcinoma cells with «Chlorhexidine» and «Мiramistin» invokes the irreversible reactions, while the composition processing of gels based on bacteriophages not further affect cell viability.Conclusions The results of the experiment confirmed the significant toxicity of tools such as «Сhlorhexidine» and «Miramistin» in proposed concentrations in the pharmacy network. Despite the high efficiency of these vehicles with regard to the studied pathogens, their long-term use in treatment of inflammatory diseases of the skin and mucous membranes can cause a slowing of repair processes. Gel means with bacteriophages

  10. Antimicrobial activity of medicinal plant leaf extracts against pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Atikya Farjana

    2014-09-01

    Full Text Available Objective: To determine antibacterial activity of water, oil and methanol extracts of guava (Psidium guajava, green tea (Camellia sinensis, neem (Azadirachta indica and marigold (Calendula officinalis against different species of bacteria, Pseudomonas spp., Vibrio cholerae, Vibrio parahaemolyticus (V. parahaemolyticus, Klebsiella spp., Escherichia coli, Salmonella spp. and Staphylococcus aureus (S. aureus. Methods: Antibacterial activity of plant extracts was measured by agar well diffusion method. Results: Boiled water extracts of guava leaf showed the largest zone of inhibition (22 mm against V. parahaemolyticus. Water extracts of green tea leaf at boiling and room temperature showed 17.5 mm and 19 mm zone of inhibitions against V. parahaemolyticus and S. aureus, respectively. Boiled water extract of neem leaf showed moderate zone of inhibition against Escherichia coli (10 mm and Klebsiella spp. (11 mm. Water and oil extracts of marigold leaf at both boiling and room temperature did not show any zone of inhibition against any of the tested microorganisms. Methanol extracts of both guava and green tea leaves showed same zone of inhibition against Pseudomonus spp. (18 mm. Methanol extract of neem leaf showed antibacterial acitivity against Klebsiella spp. (16 mm and Vibrio cholerae (14 mm and that of marigold leaf showed antimicrobial activity against S. aureus (18 mm and Klebsiella spp. (12 mm. Conclusions: The results from the study suggest that the leaves of guava, green tea, neem and marigold show anibacterial activity against different bacterial species. They could be used as alternatives to common antimicrobial agents for treatment of bacterial infections.

  11. In Vivo, In Vitro, and In Silico Characterization of Peptoids as Antimicrobial Agents

    DEFF Research Database (Denmark)

    Czyzewski, Ann M.; Jenssen, Håvard; Fjell, Christopher D.

    2016-01-01

    report a new QSAR model that we developed based on 27 diverse peptoid sequences, which accurately correlates antimicrobial peptoid structure with antimicrobial activity. We have identified a number of peptoids that have potent, broad-spectrum in vitro activity against multi-drug resistant bacterial......Bacterial resistance to conventional antibiotics is a global threat that has spurred the development of antimicrobial peptides (AMPs) and their mimetics as novel anti-infective agents. While the bioavailability of AMPs is often reduced due to protease activity, the non-natural structure of AMP...... potential of peptoids as antimicrobial agents....

  12. Nontherapeutic Use of Antimicrobial Agents in Animal Agriculture: Implications for Pediatrics.

    Science.gov (United States)

    Paulson, Jerome A; Zaoutis, Theoklis E

    2015-12-01

    Antimicrobial resistance is one of the most serious threats to public health globally and threatens our ability to treat infectious diseases. Antimicrobial-resistant infections are associated with increased morbidity, mortality, and health care costs. Infants and children are affected by transmission of susceptible and resistant food zoonotic pathogens through the food supply, direct contact with animals, and environmental pathways. The overuse and misuse of antimicrobial agents in veterinary and human medicine is, in large part, responsible for the emergence of antibiotic resistance. Approximately 80% of the overall tonnage of antimicrobial agents sold in the United States in 2012 was for animal use, and approximately 60% of those agents are considered important for human medicine. Most of the use involves the addition of low doses of antimicrobial agents to the feed of healthy animals over prolonged periods to promote growth and increase feed efficiency or at a range of doses to prevent disease. These nontherapeutic uses contribute to resistance and create new health dangers for humans. This report describes how antimicrobial agents are used in animal agriculture, reviews the mechanisms of how such use contributes to development of resistance, and discusses US and global initiatives to curb the use of antimicrobial agents in agriculture. Copyright © 2015 by the American Academy of Pediatrics.

  13. Novel food packaging systems with natural antimicrobial agents.

    Science.gov (United States)

    Irkin, Reyhan; Esmer, Ozlem Kizilirmak

    2015-10-01

    A new type of packaging that combines food packaging materials with antimicrobial substances to control microbial surface contamination of foods to enhance product microbial safety and to extend shelf-life is attracting interest in the packaging industry. Several antimicrobial compounds can be combined with different types of packaging materials. But in recent years, since consumer demand for natural food ingredients has increased because of safety and availability, these natural compounds are beginning to replace the chemical additives in foods and are perceived to be safer and claimed to alleviate safety concerns. Recent research studies are mainly focused on the application of natural antimicrobials in food packaging system. Biologically derived compounds like bacteriocins, phytochemicals, enzymes can be used in antimicrobial food packaging. The aim of this review is to give an overview of most important knowledge about application of natural antimicrobial packagings with model food systems and their antimicrobial effects on food products.

  14. Aquatic plants as potential sources of antimicrobial compounds ...

    African Journals Online (AJOL)

    Resistance of pathogens to common veterinary antibiotics hampers mastitis treatment and motivates the discovery of new antimicrobials. In this study, extracts from two aquatic plants, Salvinia auriculata and Hydrocleys nymphoides, were assayed against bovine mastitis pathogens. Selected parts of plants were extracted ...

  15. In Vitro Antimicrobial Assay Of Plants Used In Traditional Medicine ...

    African Journals Online (AJOL)

    The paper discusses the probable therapeutic basis of these traditional plants based on their secondary metabolite profiles and for the first time draws research attention to Bukoba Rural district as a source for plants with potential pharmaceutical applications. Keywords: Antimicrobial activity, Secondary metabolites, ...

  16. An Investigation on the antimicrobial activity of some endemic plant ...

    African Journals Online (AJOL)

    In this study performed on six endemic plant species, antimicrobial activity was observed in Campanula lyrata subsp.lyrata and Abies nordmanniana subsp. bornmuelleriana plants. The minimum inhibitory concentration of C. lyrata subsp. lyrata (leaf and flower) extract was found to be 29 mg/ml for Baccillus subtilis and 14.5 ...

  17. Effects of treatment with antimicrobial agents on the human colonic microflora

    OpenAIRE

    Rafii, Fatemeh

    2008-01-01

    Fatemeh Rafii, John B Sutherland, Carl E CernigliaDivision of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR, USAAbstract: Antimicrobial agents are the most valuable means available for treating bacterial infections. However, the administration of therapeutic doses of antimicrobial agents to patients is a leading cause of disturbance of the normal gastrointestinal microflora. This disturbance results in diminishing the natural defense mechanisms provided by the c...

  18. Effects of treatment with antimicrobial agents on the human colonic microflora

    Directory of Open Access Journals (Sweden)

    Fatemeh Rafii

    2008-12-01

    Full Text Available Fatemeh Rafii, John B Sutherland, Carl E CernigliaDivision of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR, USAAbstract: Antimicrobial agents are the most valuable means available for treating bacterial infections. However, the administration of therapeutic doses of antimicrobial agents to patients is a leading cause of disturbance of the normal gastrointestinal microflora. This disturbance results in diminishing the natural defense mechanisms provided by the colonic microbial ecosystem, making the host vulnerable to infection by commensal microorganisms or nosocomial pathogens. In this minireview, the impacts of antimicrobials, individually and in combinations, on the human colonic microflora are discussed.Keywords: antibiotics, intestinal bacteria

  19. Variations in the sales and sales patterns of veterinary antimicrobial agents in 25 European countries.

    Science.gov (United States)

    Grave, Kari; Torren-Edo, Jordi; Muller, Arno; Greko, Christina; Moulin, Gerard; Mackay, David

    2014-08-01

    To describe sales and sales patterns of veterinary antimicrobial agents in 25 European Union (EU)/European Economic Area (EEA) countries for 2011. Data on the sales of veterinary antimicrobial agents from 25 EU member states and EEA countries for 2011 were collected at package level (name, formulation, strength, pack size, number of packages sold) according to a standardized protocol and template and presented in a harmonized manner. These data were calculated to express amounts sold, in metric tonnes, of active ingredient of each package. A population correction unit (PCU) was applied as a proxy for the animal biomass potentially treated with antimicrobial agents. The indicator used to express sales was milligrams of active substance per PCU. Substantial variations in the sales patterns and in the magnitude of sales of veterinary antimicrobial agents, expressed as mg/PCU, between the countries were observed. The proportion of sales, in mg/PCU, of products applicable for treatment of groups or herds of animals (premixes, oral powders and oral solution) varied considerably between the countries. Some countries reported much lower sales of veterinary antimicrobial agents than others, when expressed as mg/PCU. Sales patterns varied between countries, particularly with respect to pharmaceutical forms. Further studies are needed to understand the factors that explain the observed differences. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Investigating the Antimicrobial Bioactivity of Cyano bacterial Extracts on Some Plant and Human Pathogens

    International Nuclear Information System (INIS)

    El-Semary, N.A.; Osman, M.E.; Ahmed, A.S.; Botros, H.W.; Farag, A.T.

    2014-01-01

    The search for broad spectrum antimicrobial agents against microbial pathogens, as the available bioactive compounds, has decreasing efficacy and the multidrug resistance trait is spreading among pathogens. Accordingly, the study was carried out to investigate the antimicrobial bioactivity of extracts derived from a cyano bacterial strain from Egypt. The solvents used were diethyl ether, chloroform and methanol. The antimicrobial bioassay of the lipophilic fraction dissolved in diethyl ether of Synechococcus spp. (isolated from Wadi El-Natroun, Egypt) showed the highest broad spectrum bioactivity as it inhibited the growth of both plant and human pathogens. The extract was also effective on the filamentous plant pathogenic fungi Aspergillus flavus and Aspergillus niger. The effects of incubation periods, growth media and pH values on both growth and antimicrobial activity of Synechococcus spp. were investigated. Chu medium was the medium that gave the highest growth followed by BG11 medium then Oscillatoria medium and all these three media showed antibacterial activities but only BG11 showed both antibacterial and antifungal activities after 18 days of incubation. The pH value 10 proved to be the best for growth and antimicrobial activities of Synechococcus spp. in BG11 medium

  1. In vitro evaluation of the root canal cleaning ability of plant extracts and their antimicrobial action

    Directory of Open Access Journals (Sweden)

    Edja Maria Melo de Brito Costa

    2012-06-01

    Full Text Available This in vitro study evaluated both the antimicrobial activity and the root canal cleaning ability of plant extracts used in irrigation solutions. The antimicrobial activities of the aroeira-da-praia (Schinus terebintifolius Raddi and the quixabeira (Syderoxylum obtusifolium Roem & Schult hydroalcoholic extracts, of 2.5% sodium hypochlorite (NaOCl and of 0.12% chlorhexidine (positive control against Enterococcus faecalis were tested with the agar well diffusion method. The level of root canal cleanliness was examined by scanning electron microscopy (SEM. Twenty one single-rooted human teeth were divided into three groups according to the irrigation solution applied: 1 50% aroeira-da-praia; 2 50% quixabeira and 3 a combination of 2.5% sodium hypochlorite + 17% EDTA. All solutions tested demonstrated antimicrobial activity against Enterococcus faecalis. The SEM analysis revealed that higher and lower degrees of surface cleaning were observed, in the three groups, respectively for the coronal and apical thirds, in that quixabeira showed the greatest efficiency in removing the smear layer in the apical third. All the agents tested presented antimicrobial activity against E. faecalis. None, however, was able to completely remove the smear layer of the dentinal surface in the different thirds of the root canal. The results suggest that the analyzed plant extracts may represent a new therapeutic option in the list of alternative agents available for endodontic treatment.

  2. 241 Comparative Effectiveness of Certain Antimicrobial Agents in ...

    African Journals Online (AJOL)

    Nekky Umera

    Indexed African Journals Online: www.ajol.info ... effectiveness of antimicrobial preservation during storage life of preparations ... The low cost and long history of safe use probably explains the .... In Hugo, W.B and Rusell, A.D. Pharmaceutical.

  3. Antimicrobial activity of Olea europaea Linné extracts and their applicability as natural food preservative agents.

    Science.gov (United States)

    Thielmann, J; Kohnen, S; Hauser, C

    2017-06-19

    The antimicrobial activity of phenolic compounds from Olea (O.) europaea Linné (L.) is part of the scientific discussion regarding the use of natural plant extracts as alternative food preservative agents. Although, the basic knowledge on the antimicrobial potential of certain molecules such as oleuropein, hydroxytyrosol or elenolic acid derivatives is given, there is still little information regarding their applicability for food preservation. This might be primarily due to the lack of information regarding the full antimicrobial spectrum of the compounds, their synergisms in natural or artificial combinations and their interaction with food ingredients. The present review accumulates available literature from the past 40 years, investigating the antimicrobial activity of O. europaea L. derived extracts and compounds in vitro and in food matrices, in order to evaluate their food applicability. In summary, defined extracts from olive fruit or leaves, containing the strongest antimicrobial compounds hydroxytyrosol, oleacein or oleacanthal in considerable concentrations, appear to be suitable for food preservation. Nonetheless there is still need for consequent research on the compounds activity in food matrices, their effect on the natural microbiota of certain foods and their influence on the sensorial properties of the targeted products. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Antimicrobial effects of Thai medicinal plants against acne-inducing bacteria.

    Science.gov (United States)

    Chomnawang, Mullika Traidej; Surassmo, Suvimol; Nukoolkarn, Veena S; Gritsanapan, Wandee

    2005-10-03

    Propionibacterium acnes and Staphylococcus epidermidis have been recognized as pus-forming bacteria triggering an inflammation in acne. The present study was conducted to evaluate antimicrobial activities of Thai medicinal plants against these etiologic agents of acne vulgaris. Crude extracts were tested for antimicrobial activities by disc diffusion and broth dilution methods. The results from the disc diffusion method showed that 13 medicinal plants could inhibit the growth of Propionibacterium acnes. Among those, Senna alata, Eupatorium odoratum, Garcinia mangostana, and Barleria lupulina had strong inhibitory effects. Based on a broth dilution method, the Garcinia mangostana extract had the greatest antimicrobial effect. The MIC values were the same (0.039 mg/ml) for both bacterial species and the MBC values were 0.039 and 0.156 mg/ml against Propionibacterium acnes and Staphylococcus epidermidis, respectively. In bioautography assay, the Garcinia mangostana extract produced strong inhibition zones against Propionibacterium acnes. Antimicrobial activity from fractions of column chromatography revealed one of the active compounds in Garcinia mangostana could be mangostin, a xanthone derivative. Taken together, our data indicated that Garcinia mangostana had a strong inhibitory effect on Propionibacterium acnes and Staphylococcus epidermidis. Therefore, this plant would be an interesting topic for further study and possibly for an alternative treatment for acne.

  5. Optimization of extinguishing agents for nuclear power plants

    International Nuclear Information System (INIS)

    Boleman, M.; Lipar, M.; Balog, K.

    1998-01-01

    Focus is placed on use of extinguishing agents in nuclear power plants. The advantages and disadvantages of these agents are compared. Further perspectives for using particular extinguishing agents in nuclear power plants are outlined. (author)

  6. Antimicrobial and antioxidant activities of two endemic plants from ...

    African Journals Online (AJOL)

    In addition to the antioxidant activity of these plants, the total phenolic compounds and flavonoids were also measured in the extracts. ... that the extracts of A. scabriflorum and A. tchihatschewii possess antimicrobial and antioxidant properties, and therefore, they can be used as a natural preservative ingredient in food

  7. Antimicrobial nature and use of some medicinal plants in Nigeria

    African Journals Online (AJOL)

    SERVER

    2008-03-04

    Mar 4, 2008 ... Forty eight medicinal plants in Nigeria were screened for their antimicrobial ... are capable of producing toxic materials, which may exert some ... is commonly used as a means of evaluating drugs or .... zones of growth inhibition and the diameter of these zones were ..... region of Eastern Ghat, S India. Sci.

  8. Screening of some Siberian medicinal plants for antimicrobial activity

    Czech Academy of Sciences Publication Activity Database

    Kokoška, L.; Polesný, Z.; Rada, V.; Nepovím, Aleš; Vaněk, Tomáš

    2002-01-01

    Roč. 82, - (2002), s. 51-53 ISSN 0378-8741 R&D Projects: GA ČR GA525/02/0257 Institutional research plan: CEZ:AV0Z4055905 Keywords : antimicrobial activity * medicinal plants Subject RIV: CE - Biochemistry Impact factor: 1.188, year: 2002

  9. In vitro antimicrobial activity of ten medicinal plants against clinical isolates of oral cancer cases.

    Science.gov (United States)

    Panghal, Manju; Kaushal, Vivek; Yadav, Jaya P

    2011-05-20

    significant antimicrobial activity (P medicinal plant can prove as effective antimicrobial agent to check the secondary infections in treated cancer patients.

  10. A novel approach to pharmacodynamic assessment of antimicrobial agents: new insights to dosing regimen design.

    Directory of Open Access Journals (Sweden)

    Vincent H Tam

    Full Text Available Pharmacodynamic modeling has been increasingly used as a decision support tool to guide dosing regimen selection, both in the drug development and clinical settings. Killing by antimicrobial agents has been traditionally classified categorically as concentration-dependent (which would favor less fractionating regimens or time-dependent (for which more frequent dosing is preferred. While intuitive and useful to explain empiric data, a more informative approach is necessary to provide a robust assessment of pharmacodynamic profiles in situations other than the extremes of the spectrum (e.g., agents which exhibit partial concentration-dependent killing. A quantitative approach to describe the interaction of an antimicrobial agent and a pathogen is proposed to fill this unmet need. A hypothetic antimicrobial agent with linear pharmacokinetics is used for illustrative purposes. A non-linear functional form (sigmoid Emax of killing consisted of 3 parameters is used. Using different parameter values in conjunction with the relative growth rate of the pathogen and antimicrobial agent concentration ranges, various conventional pharmacodynamic surrogate indices (e.g., AUC/MIC, Cmax/MIC, %T>MIC could be satisfactorily linked to outcomes. In addition, the dosing intensity represented by the average kill rate of a dosing regimen can be derived, which could be used for quantitative comparison. The relevance of our approach is further supported by experimental data from our previous investigations using a variety of gram-negative bacteria and antimicrobial agents (moxifloxacin, levofloxacin, gentamicin, amikacin and meropenem. The pharmacodynamic profiles of a wide range of antimicrobial agents can be assessed by a more flexible computational tool to support dosing selection.

  11. [Spanish scientific production in antimicrobial agents and susceptibility procedures during period 1990-2002].

    Science.gov (United States)

    Ramos, J M; Gutiérrez, F; Royo, G

    2005-03-01

    The aim of this study was to analyze the scientific production of Spanish authors on antimicrobial agents and susceptibility tests during the period 1990-2002. Articles from Spanish scientific institutions of microbiology, bacteriology, mycology and parasitology published and recorded in the MEDLINE database (WEBSPIRS version 4.2) during the period 1990-2002 were selected. Only articles about antimicrobial agents and susceptibility procedures were reviewed. A total of 5,259 documents were analyzed, of which 1,041 (19.8%) were about antimicrobal agents. The annual number of documents increased by two-fold (from 48 in 1990 to 101 in 2002). The journal that published most documents was Antimicrobial Agents and Chemotherapy, with 183 (17.1%). The main field of interest of the documents was antimicrobial agents and susceptibility tests (765; 73.5%) and in vitro resistance analyses (265; 25.5%). The highest number of contributions came from hospitals (571; 54.9%), followed by universities (351; 33.7%). The institutions with most documents published were the Ramón y Cajal Hospital (8.6%), and Seville University Faculty of Medicine (6%). The most productive autonomous communities were Madrid (43.4%), Catalonia (16.4%) and Andalusia (4.7%). A total of 787 documents (75.6%) were published in journals with impact factors and the mean expected impact factor was 2.390 +/- 1.546. It was concluded that the scientific production of Spanish researchers in antimicrobial agents had increased during the period 1990-2002, and that hospitals were the most productive institutions in this area of microbiology, with the main areas of interest being antimicrobial agents and susceptibility tests.

  12. Occurrence of Salmonella spp. in broiler chicken carcasses and their susceptibility to antimicrobial agents

    Science.gov (United States)

    Duarte, Dalila Angélica Moliterno; Ribeiro, Aldemir Reginato; Vasconcelos, Ana Mércia Mendes; Santos, Sylnei Barros; Silva, Juliana Vital Domingos; de Andrade, Patrícia Lúcia Arruda; de Arruda Falcão, Lúcia Sadae Pereira da Costa

    2009-01-01

    The present study was carried out to evaluate the occurrence of Salmonellae in broiler chicken carcasses and to determine the antimicrobial resistance profile of the isolated strains. Twenty-five out of the 260 broiler chicken carcasses samples (9.6%) were positive for Salmonella. S. Enteritidis was the most frequent serovar. Nineteen Salmonella isolates were tested for antimicrobial resistance, and the results indicated that 94.7% were resistant to at least one antimicrobial agent. Resistance to streptomycin (73.7%), nitrofurantoin (52.3%), tetracycline (31.6%), and nalidixic acid (21%) were the prevalent amongst Salmonella strains tested. PMID:24031401

  13. Synthesis and characterization of barbitones as antimicrobial agents

    Directory of Open Access Journals (Sweden)

    H. G. SANGANI

    2006-06-01

    Full Text Available Barbitones (3 were synthesised by the condensation of chalcones (2 with barbituric acid. The structure of the synthesized compounds were assigned on the basis of elemental analyses, IR, NMR and mass spectral studies. All the products were evaluated for their in vitro antimicrobial activity against various strains of bacteria and fungi.

  14. Protein C Inhibitor-A Novel Antimicrobial Agent

    NARCIS (Netherlands)

    Malmström, E.; Mörgelin, M.; Malmsten, M.; Johansson, L.; Norrby-Teglund, A.; Shannon, O.; Schmidtchen, A.; Meijers, J.C.M.; Herwald, H.

    2009-01-01

    Protein C inhibitor (PCI) is a heparin-binding serine proteinase inhibitor belonging to the family of serpin proteins. Here we describe that PCI exerts broad antimicrobial activity against bacterial pathogens. This ability is mediated by the interaction of PCI with lipid membranes, which

  15. Association between the consumption of antimicrobial agents in animal husbandry and the occurrence of resistant bacteria among food animals

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller

    1999-01-01

    Antimicrobial agents are used in food animals for therapy and prophylaxis of bacterial infections and in feed to promote growth. The use of antimicrobial agents for food animals may cause problems in the therapy of infections by selecting for resistance among bacteria pathogenic for animals...... animals, the quantitative impact of the use of different antimicrobial agents on selection for resistance and the most appropriate treatment regimens to limit the development of resistance is incomplete. Surveillance programmes monitoring the occurrence and development of resistance and consumption...... or humans. The emergence of resistant bacteria and resistance genes following the use of antimicrobial agents is relatively well documented and it seems evident that all antimicrobial agents will select for resistance. However, current knowledge regarding the occurrence of antimicrobial resistance in food...

  16. Antioxidant and antimicrobial activities of selected medicinal plants from Algeria

    Institute of Scientific and Technical Information of China (English)

    Krimat Soumia; Dob Tahar; Lamari Lynda; Boumeridja Saida; Chelghoum Chabane; Metidji Hafidha

    2014-01-01

    Objective:To evaluate the antioxidant and antimicrobial activity of methanolic extract extracts of selected Algerian medicinal plants. Methods:Antioxidant activity of extracts was evaluated in terms of radical scavenging potential (2,2-diphenyl-1-picrylhydrazyl) and β-carotene bleaching assay. Total phenolic contents and flavonoid contents were also measured. Antimicrobial activity of these plants was examined against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. Results:The values of IC50 ranged from 4.30 μg/mL to 486.6 μg/mL for the DPPH method, while total antioxidant activity using β-carotene/linoleic acid bleaching assay ranged from 17.03%to 86.13%. It was found that Pistacia lentiscus showed the highest antioxidant capacities using DPPH assay (IC50=4.30 μg/mL), while Populus trimula, Origanum glandulosum, Centaurea calcitrapa, Sysimbrium officinalis and Rhamnus alaternus showed the highest percent of total antioxidant activity inβ-carotene/linoleic acid bleaching assay. Total phenolic and flavonoid contents ranged from 3.96 to 259.65 mg GAE/g extract and from 1.13 to 26.84 mg QE/g extract, respectively. The most interesting antimicrobial activity was obtained from Sysimbrium officinalis, Rhamnus alaternus, Origanum glandulosum, Cupressus sempervirens, Pinus halipensis and Centaurea calcitrapa. Conclusions:The results indicated that the plants tested may be potential sources for isolation of natural antioxidant and antimicrobial compounds.

  17. SCREENING OF PLANT EXTRACTS FOR ANTIMICROBIAL ACTIVITY AGAINST BACTERIA

    Directory of Open Access Journals (Sweden)

    Alexander Vatľák

    2014-02-01

    Full Text Available The aim of this study was antimicrobial action of the methanolic extracts of Equisetum arvense L. and Urtica dioica L. against gramnegative and grampositive bacteria. The antimicrobial activities of the extracts against gramnegative bacteria: Escherichia coli CCM 3988, Listeria ivanovii CCM 5884, Listeria innocua CCM 4030, Pseudomonas aeruginosa CCM 1960, Serratia rubidaea CCM 4684 and grampositive bacteria: Brochothrix thermosphacta CCM 4769, Enterococcus raffinosus CCM 4216, Lactobacillus rhamnosus CCM 1828, Paenobacillus larvae CCM 4483 and Staphylococcus epidermis CCM 4418 were determined by the disc diffusion method and the microbroth dilution method according to CLSI. Probit analysis was used in this experiment. Of the 2 plant extracts tested, all extracts showed antimicrobial activity against one or more species of microorganisms. The most antimicrobial activity showed methanolic plant extract of E. arvense against S. epidermis with disc diffusion method and with microbroth dilution method against S. rubidaea and plant extract Urtica dioica with disc diffusion method against P. aeruginosa and with microbroth dilution method against S. rubidaea and E. coli.

  18. Antimicrobial Peptides Derived from Fusion Peptides of Influenza A Viruses, a Promising Approach to Designing Potent Antimicrobial Agents.

    Science.gov (United States)

    Wang, Jingyu; Zhong, Wenjing; Lin, Dongguo; Xia, Fan; Wu, Wenjiao; Zhang, Heyuan; Lv, Lin; Liu, Shuwen; He, Jian

    2015-10-01

    The emergence and dissemination of antibiotic-resistant bacterial pathogens have spurred the urgent need to develop novel antimicrobial agents with different mode of action. In this respect, we turned several fusogenic peptides (FPs) derived from the hemagglutinin glycoproteins (HAs) of IAV into potent antibacterials by replacing the negatively or neutrally charged residues of FPs with positively charged lysines. Their antibacterial activities were evaluated by testing the MICs against a panel of bacterial strains including S. aureus, S. mutans, P. aeruginosa, and E. coli. The results showed that peptides HA-FP-1, HA-FP-2-1, and HA-FP-3-1 were effective against both Gram-positive and Gram-negative bacteria with MICs ranging from 1.9 to 16.0 μm, while the toxicities toward mammalian cells were low. In addition, the mode of action and the secondary structure of these peptides were also discussed. These data not only provide several potent peptides displaying promising potential in development as broad antimicrobial agents, but also present a useful strategy in designing new antimicrobial agents. © 2015 John Wiley & Sons A/S.

  19. In vitro antimicrobial activity of ten medicinal plants against clinical isolates of oral cancer cases

    Science.gov (United States)

    2011-01-01

    Background Suppression of immune system in treated cancer patients may lead to secondary infections that obviate the need of antibiotics. In the present study, an attempt was made to understand the occurrence of secondary infections in immuno-suppressed patients along with herbal control of these infections with the following objectives to: (a) isolate the microbial species from the treated oral cancer patients along with the estimation of absolute neutrophile counts of patients (b) assess the in vitro antimicrobial activity medicinal plants against the above clinical isolates. Methods Blood and oral swab cultures were taken from 40 oral cancer patients undergoing treatment in the radiotherapy unit of Regional Cancer Institute, Pt. B.D.S. Health University, Rohtak, Haryana. Clinical isolates were identified by following general microbiological, staining and biochemical methods. The absolute neutrophile counts were done by following the standard methods. The medicinal plants selected for antimicrobial activity analysis were Asphodelus tenuifolius Cav., Asparagus racemosus Willd., Balanites aegyptiaca L., Cestrum diurnum L., Cordia dichotoma G. Forst, Eclipta alba L., Murraya koenigii (L.) Spreng. , Pedalium murex L., Ricinus communis L. and Trigonella foenum graecum L. The antimicrobial efficacy of medicinal plants was evaluated by modified Kirby-Bauer disc diffusion method. MIC and MFC were investigated by serial two fold microbroth dilution method. Results Prevalent bacterial pathogens isolated were Staphylococcus aureus (23.2%), Escherichia coli (15.62%), Staphylococcus epidermidis (12.5%), Pseudomonas aeruginosa (9.37%), Klebsiella pneumonia (7.81%), Proteus mirabilis (3.6%), Proteus vulgaris (4.2%) and the fungal pathogens were Candida albicans (14.6%), Aspergillus fumigatus (9.37%). Out of 40 cases, 35 (87.5%) were observed as neutropenic. Eight medicinal plants (A. tenuifolius, A. racemosus, B. aegyptiaca, E. alba, M. koenigii, P. murex R. communis and T

  20. Isolation and characterization of antimicrobial compounds in plant extracts against multidrug-resistant Acinetobacter baumannii.

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    Yoko Miyasaki

    Full Text Available The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant Acinetobacter baumannii (A. baumannii is extremely limited. Magnolia officinalis, Mahonia bealei, Rabdosia rubescens, Rosa rugosa, Rubus chingii, Scutellaria baicalensis, and Terminalia chebula plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of A. baumannii. In this study, the compounds responsible for their antimicrobial activity were identified by fractionating each plant extract using high performance liquid chromatography, and determining the antimicrobial activity of each fraction against A. baumannii. The chemical structures of the fractions inhibiting >40% of the bacterial growth were elucidated by liquid chromatography/mass spectrometry analysis and nuclear magnetic resonance spectroscopy. The six most active compounds were identified as: ellagic acid in Rosa rugosa; norwogonin in Scutellaria baicalensis; and chebulagic acid, chebulinic acid, corilagin, and terchebulin in Terminalia chebula. The most potent compound was identified as norwogonin with a minimum inhibitory concentration of 128 µg/mL, and minimum bactericidal concentration of 256 µg/mL against clinically relevant strains of A. baumannii. Combination studies of norwogonin with ten anti-Gram negative bacterial agents demonstrated that norwogonin did not enhance the antimicrobial activity of the synthetic antibiotics chosen for this study. In conclusion, of all identified antimicrobial compounds, norwogonin was the most potent against multidrug-resistant A. baumannii strains. Further studies are warranted to ascertain the prophylactic and therapeutic potential of norwogonin for infections due to multidrug-resistant A. baumannii.

  1. ANTIMICROBIAL ACTIVITY OF ESSENTIAL OILS OF PLANTS BELONGING TO LAMIACEAE JUSS. FAMILY

    Directory of Open Access Journals (Sweden)

    Shanayda M.I.

    2015-12-01

    Full Text Available Introduction. One of the important sources of therapeutic and prophylactic agents of modern medicines are essential oils of medicinal plants. Essential oils are the main group of biologically active substances of a number of plants belonging to Lamiaceae Juss. Family. Antibacterial activity of medicinal plants belonging to Lamiaceae Family many scientists associated with containing of essential oils. In this regard, considerable interest presents the comparative analysis of the antimicrobial properties of essential oils of Lamiaceae Family representatives. Material and methods.The antimicrobial activity of essential oils of investigated plants was studied with using in vitro condition. The essential oils derived from the aerial parts of cultivated plants of Ocimum, Hyssopus, Dracocephalum, Lophanthus, Monarda and Satureja genus harvested during flowering period (in terms of Ternopil region. The antimicrobial activity of essential oils studied plants was studied by serial dilution method and disk diffusion assay. It has been applied on standard microorganism test strains: Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027 and Candida albicans ATCC 885-653. Results and discussion. It was conducted a comparative study of the influence of some essential oils of cultivated plants belonging to Lamiaceae family on microorganisms in conditions in vitro. It was found that essential oils of the studied plants were most effective in the maximum concentration (1:10. Gram-positive cocci S. aureus and yeast C. albicans were the most sensitive to influence of investigated essential oils. It was analyzed the relationship of the biological activity with the component composition of essential oils of plants. Essential oils of L. anisatus, M. fistulosa and S. hortensis characterized by the dominance of aromatic compounds and had shown stronger antimicrobial activity than essential oils of

  2. Screening of plant extracts for antimicrobial activity against bacteria and yeasts with dermatological relevance.

    Science.gov (United States)

    Weckesser, S; Engel, K; Simon-Haarhaus, B; Wittmer, A; Pelz, K; Schempp, C M

    2007-08-01

    There is cumulative resistance against antibiotics of many bacteria. Therefore, the development of new antiseptics and antimicrobial agents for the treatment of skin infections is of increasing interest. We have screened six plant extracts and isolated compounds for antimicrobial effects on bacteria and yeasts with dermatological relevance. The following plant extracts have been tested: Gentiana lutea, Harpagophytum procumbens, Boswellia serrata (dry extracts), Usnea barbata, Rosmarinus officinalis and Salvia officinalis (supercritical carbon dioxide [CO2] extracts). Additionally, the following characteristic plant substances were tested: usnic acid, carnosol, carnosic acid, ursolic acid, oleanolic acid, harpagoside, boswellic acid and gentiopicroside. The extracts and compounds were tested against 29 aerobic and anaerobic bacteria and yeasts in the agar dilution test. U. barbata-extract and usnic acid were the most active compounds, especially in anaerobic bacteria. Usnea CO2-extract effectively inhibited the growth of several Gram-positive bacteria like Staphylococcus aureus (including methicillin-resistant strains - MRSA), Propionibacterium acnes and Corynebacterium species. Growth of the dimorphic yeast Malassezia furfur was also inhibited by Usnea-extract. Besides the Usnea-extract, Rosmarinus-, Salvia-, Boswellia- and Harpagophytum-extracts proved to be effective against a panel of bacteria. It is concluded that due to their antimicrobial effects some of the plant extracts may be used for the topical treatment of skin disorders like acne vulgaris and seborrhoic eczema.

  3. Antimicrobial Activity of Bacteriophage Endolysin Produced in Nicotiana benthamiana Plants.

    Science.gov (United States)

    Kovalskaya, Natalia; Foster-Frey, Juli; Donovan, David M; Bauchan, Gary; Hammond, Rosemarie W

    2016-01-01

    The increasing spread of antibiotic-resistant pathogens has raised the interest in alternative antimicrobial treatments. In our study, the functionally active gram-negative bacterium bacteriophage CP933 endolysin was produced in Nicotiana benthamiana plants by a combination of transient expression and vacuole targeting strategies, and its antimicrobial activity was investigated. Expression of the cp933 gene in E. coli led to growth inhibition and lysis of the host cells or production of trace amounts of CP933. Cytoplasmic expression of the cp933 gene in plants using Potato virus X-based transient expression vectors (pP2C2S and pGR107) resulted in death of the apical portion of experimental plants. To protect plants against the toxic effects of the CP933 protein, the cp933 coding region was fused at its Nterminus to an N-terminal signal peptide from the potato proteinase inhibitor I to direct CP933 to the delta-type vacuoles. Plants producing the CP933 fusion protein did not exhibit the severe toxic effects seen with the unfused protein and the level of expression was 0.16 mg/g of plant tissue. Antimicrobial assays revealed that, in contrast to gram-negative bacterium E. coli (BL21(DE3)), the gram-positive plant pathogenic bacterium Clavibacter michiganensis was more susceptible to the plant-produced CP933, showing 18% growth inhibition. The results of our experiments demonstrate that the combination of transient expression and protein targeting to the delta vacuoles is a promising approach to produce functionally active proteins that exhibit toxicity when expressed in plant cells.

  4. In vitro susceptibility of Pasteurella multocida subspecies multocida strains isolated from swine to 42 antimicrobial agents.

    Science.gov (United States)

    Gutiérrez Martin, C B; Rodríguez Ferri, E F

    1993-08-01

    The minimal inhibitory concentrations (MICs) of 42 antimicrobial agents were determined against 59 strains of Pasteurella multocida subspecies multocida, all isolated from swine lungs with lesions indicative of pneumonia. Penicillins (except cloxacillin), aminoglycosides, tetracyclines, erythromycin, josamycin, thiamphenicol, colistin, rifampin and mupirocin showed good activities, with ranging resistance between 0 and 6.8%. Higher resistance was observed for spiramycin and fosfomycin. Tylosin, vancomycin, metronidazole, dapsone and tiamulin, to which strains showed high rates of resistance, were ineffective. Cephalosporins (especially the third-generation cephalosporins) and quinolones (especially the fluorinated quinolones) were the most effective antimicrobial agents against P. multocida subsp. multocida strains and they might be of value for in vivo use.

  5. Susceptibilities of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum strains to antimicrobial agents in vitro.

    OpenAIRE

    ter Laak, E A; Noordergraaf, J H; Verschure, M H

    1993-01-01

    The purpose of this study was to determine the susceptibility of various strains of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum, which are prevalent causes of pneumonia in calves, to 16 antimicrobial agents in vitro. The MICs of the antimicrobial agents were determined by a serial broth dilution method for 16 field strains and the type strain of M. bovis, for 19 field strains and the type strain of M. dispar, and for 17 field strains of U. diversum. Final MICs for M. bovis an...

  6. Synthesis of New Macrocyclic Polyamides as Antimicrobial Agent Candidates

    Directory of Open Access Journals (Sweden)

    Osama I. Abd El-Salam

    2012-12-01

    Full Text Available A series of macrocyclic imides and Schiff-bases have been prepared via the cyclocondensation of pyridine-2,6-dicarbonyl dichloride (1 with L-ornithine methyl ester to give the corresponding macrocyclic bisester 2. Treatment of 2 with hydrazine hydrate gave macrocyclic bisacid hydrazide 3, which was used as starting material. Condensation of bishydrazide 3 with diacid anhydrides or aromatic aldehydes in refluxing acetic acid or ethanol gave the corresponding macrocyclic bisimides 4, 5a,b and macrocyclic bis- hydrazones 6a–j, respectively. The structure assignments of the new compounds were based on chemical and spectroscopic evidence. The antimicrobial screening showed that many of these newly synthesized compounds have good antimicrobial activities, comparable to ampicillin and ketaconazole used as reference drugs.

  7. Synthesis of Functionalized Arylaziridines as Potential Antimicrobial Agents

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    Arianna Giovine

    2014-08-01

    Full Text Available By using the Suzuki-Miyaura protocol, a simple straightforward synthesis of functionalized 2-arylaziridines has been developed. By means of this synthetic strategy from readily available ortho-, meta- and para-bromophenylaziridines and aryl- or heteroarylboronic acids, new aziridines could be obtained. The cross-coupling reactions occurred without ring opening of the three membered ring. Preliminary results on the antimicrobial activity of the heterosubstituted biaryl compounds have been also included.

  8. Modified lysozymes as novel broad spectrum natural antimicrobial agents in foods.

    Science.gov (United States)

    Aminlari, Ladan; Hashemi, Marjan Mohammadi; Aminlari, Mahmoud

    2014-06-01

    In recent years much attention and interest have been directed toward application of natural antimicrobial agents in foods. Some naturally occurring proteins such as lactoperoxidase, lactoferrin, and lysozyme have received considerable attention and are being considered as potential antimicrobial agents in foods. Lysozyme kills bacteria by hydrolyzing the peptidoglycan layer of the cell wall of certain bacterial species, hence its application as a natural antimicrobial agent has been suggested. However, limitations in the action of lysozyme against only Gram-positive bacteria have prompted scientists to extend the antimicrobial effects of lysozyme by several types of chemical modifications. During the last 2 decades extensive research has been directed toward modification of lysozyme in order to improve its antimicrobial properties. This review will report on the latest information available on lysozyme modifications and examine the applicability of the modified lysozymes in controlling growth of Gram-positive and Gram-negative bacteria in foods. The results of modifications of lysozyme using its conjugation with different small molecule, polysaccharides, as well as modifications using proteolytic enzymes will be reviewed. These types of modifications have not only increased the functional properties of lysozyme (such as solubility and heat stability) but also extended the antimicrobial activity of lysozyme. Many examples will be given to show that modification can decrease the count of Gram-negative bacteria in bacterial culture and in foods by as much as 5 log CFU/mL and in some cases essentially eliminated Escherichia coli. In conclusion this review demonstrates that modified lysozymes are excellent natural food preservatives, which can be used in food industry. The subject described in this review article can lead to the development of methods to produce new broad-spectrum natural antimicrobial agents, based on modification of chicken egg white lysozyme, which

  9. Chitosan-thioglycolic acid as a versatile antimicrobial agent.

    Science.gov (United States)

    Geisberger, Georg; Gyenge, Emina Besic; Hinger, Doris; Käch, Andres; Maake, Caroline; Patzke, Greta R

    2013-04-08

    As functionalized chitosans hold great potential for the development of effective and broad-spectrum antibiotics, representative chitosan derivatives were tested for antimicrobial activity in neutral media: trimethyl chitosan (TMC), carboxy-methyl chitosan (CMC), and chitosan-thioglycolic acid (TGA; medium molecular weight: MMW-TGA; low molecular weight: LMW-TGA). Colony forming assays indicated that LMW-TGA displayed superior antimicrobial activity over the other derivatives tested: a 30 min incubation killed 100% Streptococcus sobrinus (Gram-positive bacteria) and reduced colony counts by 99.99% in Neisseria subflava (Gram-negative bacteria) and 99.97% in Candida albicans (fungi). To elucidate LMW-TGA effects at the cellular level, microscopic studies were performed. Use of fluorescein isothiocyanate (FITC)-labeled chitosan derivates in confocal microscopy showed that LMW-TGA attaches to microbial cell walls, while transmission electron microscopy indicated that this derivative severely affects cell wall integrity and intracellular ultrastructure in all species tested. We therefore propose LMW-TGA as a promising and effective broad-band antimicrobial compound.

  10. Dill (Anethum graveolens L. seeds essential oil as a potential natural antioxidant and antimicrobial agent

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    Stanojević, Lj.P.

    2016-09-01

    Full Text Available Synthetic antioxidants and antimicrobial agents can induce many undesired side effects, which attracts interest of food producers and consumers in finding ingredients of natural origin. The antioxidative and antimicrobial activity of essential oil from dill (Anethum graveolens L. seeds was investigated in terms of its possible application as natural antioxidant and antimicrobial agent. DPPH test and FRAP method have been used for the investigation of antioxidative activity of essential oil. Disc-diffusion method has been used for investigation of oil antimicrobial activity on following microorganisms: Staphylococcus aureus, Listeria monocytogenes, Bacillus subtilis, Escherichia coli, Salmonella enteritidis and Candida albicans. Essential oil, in concentration of 29 mg/mL, incubated for 60 minutes has shown the highest degree of DPPH radicals’ neutralization (79.62%. FRAP activity of oil was 40.63 μmol Fe2+/g of essential oil. Essential oil showed the best antimicrobial activity on Staphylococcus aureus. Furthermore, there was a significant antimicrobial activity on all investigated microorganisms.

  11. Antimicrobial agents are societal drugs: how should this influence prescribing?

    Science.gov (United States)

    Sarkar, Paul; Gould, Ian M

    2006-01-01

    This paper is concerned with how those who prescribe antimicrobials should consider the wider repercussions of their actions. It is accepted that in an ecological system, pressure will cause evolution; this is also the case with antimicrobials, the result being the development of resistance and the therapeutic failure of drugs. To an extent, this can be ameliorated through advances by the pharmaceutical industry, but that should not stop us from critically appraising our use and modifying our behavior to slow this process down. Up to 50% of prescribing in human medicine and 80% in veterinary medicine and farming has been considered questionable. The Alliance for the Prudent Use of Antimicrobials (APUA) was approached by the WHO to review the situation. Their recommendations include decreasing the prescribing of antibacterials for nonbacterial infections. In the UK, there has been an initiative called "the path of least resistance". This encourages general practitioners to avoid prescribing or reduce the duration of prescriptions for conditions such as upper respiratory tract infections and uncomplicated urinary tract infections; this approach has been successful. Another recommendation is to reduce the prescribing of broad-spectrum antibacterials. In UK hospitals, the problems identified with the inappropriate use of antibacterials are insufficient training in infectious disease, difficulty in selecting empirical antibacterial therapy, poor use of available microbiological information, the fear of litigation and the fact that the majority of antibacterials are prescribed by the least experienced doctors. With close liaison between the laboratories and clinicians, and the development of local protocols, this can be addressed. Another recommendation is to tighten the use of antibacterial prophylaxis and to improve patient compliance. Through a combination of improved education for doctors and patients, and improved communication skills, these problems can be

  12. PHARMACOEPIDEMIOLOGY OF ANTIMICROBIAL AGENTS IN NEONATOLOGY: RESULTS OF THE RETROSPECTIVE CROSS-SECTIONAL STUDY

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    Alexey S. Kolbin

    2016-01-01

    Full Text Available Background. Infectious diseases remain the leading causes of morbidity and mortality worldwide. Against the background of ever-increasing resistance of bacteria, it is necessary to develop effective measures aimed at the structure optimization of consumption of antimicrobial agents. Therefore, the pharmacoepidemiological data describing either the consumption of antimicrobial agents or the resistance level to them is required. Objective: Our aim was to assess the antimicrobial load in term and preterm newborns during their stay in the maternity wards and/or in the intensive care units (ICU. Methods. A retrospective cross-sectional study has been carried out. The analysis included data of 419 newborns from 5 medical centers. The study has been carried out as part of a multi-purpose program on antibiotic resistance containment being held in St. Petersburg from 2014. Results. The antimicrobial load on the child's body expressed in days of the antimicrobial therapy was 1,838 per 1,000 patient-days in children staying in the ICU for not more than 16 days, and 1,434 per 1,000 patient-days when staying in the ICU for more than 16 days. The average duration of the antimicrobial therapy is 28 days in the ICU and 5 days out the ICU (department for newborns, physiological departments. The most commonly, the children were treated with ampicillin — 384 (92%, gentamicin — 254 (61%, and fluconazole — 150 (36%. The prevalence of off-label prescriptions was 41% (of 1,557 analyzed prescriptions, unlicensed prescriptions — 10%. Congenital infections were the main reasons for prescription of antimicrobial drugs — 225 (62%. Conclusion. The high anti-bacterial load in newborns has been established. The indicator 'days of antimicrobial therapy' in the ICU is 4 times higher than that in the United States. The prevalence of off-label and unlicensed prescriptions is comparable with foreign data.

  13. Benzofuran as a promising scaffold for the synthesis of antimicrobial and antibreast cancer agents: A review

    Directory of Open Access Journals (Sweden)

    Ghadamali Khodarahmi

    2015-01-01

    Full Text Available Benzofuran as an important heterocyclic compound is extensively found in natural products as well as synthetic materials. Since benzofuran drivatives display a diverse array of pharmacological activities, an interest in developing new biologically active agents from benzofuran is still under consideration. This review highlights recent findings on biological activities of benzofuran derivatives as antimicrobial and antibreast cancer agents and lays emphasis on the importance of benzofurans as a major source for drug design and development.

  14. Evaluating bionanoparticle infused fungal metabolites as a novel antimicrobial agent

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    Kartikeya Rajpal

    2016-01-01

    Full Text Available Therapeutic properties of fungal metabolites and silver nanoparticles have been well documented. While fungal metabolites have been used for centuries as medicinal drugs, potential of biogenic silver nanoparticles has recently received attention. We have evaluated the antimicrobial potential of Aspergillus terreus crude extract, silver nanoparticles and an amalgamation of both against four pathogenic bacterial strains. Antimicrobial activity of the following was evaluated – A. terreus extract, biogenic silver nanoparticles, and a mixture containing extract and nanoparticles. Four pathogenic bacteria - Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, and Bacillus cereus were used as test organisms. Phenol, flavonoid, and alkaloid content of extract were determined to understand the chemical profile of the fungus. The extract contained significantly high amounts of phenols, flavonoids, and alkaloids. The extract and biogenic silver nanoparticle exhibited significant antibacterial activity at concentrations of 10 μg/ml and 1 μg/ml, respectively. When used in combination, the extract-nanoparticle mixture showed equally potent antibacterial activity at a much lower concentration of 2.5 μg/ml extract + 0.5 μg/ml nanoparticle. Given its high antibacterial potential, the fungal extract can be a promising source of novel drug lead compounds. The extract – silver nanoparticle mixture exhibited synergism in their antibacterial efficacy. This property can be further used to formulate new age drugs.

  15. Synthesis, biological evaluation and QSAR study of a series of substituted quinazolines as antimicrobial agents

    Czech Academy of Sciences Publication Activity Database

    Buha, V. M.; Rana, D. N.; Chhabria, M. T.; Chikhalia, K. H.; Mahajan, B. M.; Brahmkshatriya, Pathik; Shah, N. K.

    2013-01-01

    Roč. 22, č. 9 (2013), s. 4096-4109 ISSN 1054-2523 Institutional support: RVO:61388963 Keywords : antimicrobial agents * quantitative structure-activity relationship * genetic function approximation * quinazoline Subject RIV: CE - Biochemistry Impact factor: 1.612, year: 2012

  16. Screening of in vitro antimicrobial activity of plants used in traditional Indonesian medicine.

    Science.gov (United States)

    Romulo, Andreas; Zuhud, Ervizal A M; Rondevaldova, Johana; Kokoska, Ladislav

    2018-12-01

    In many regions of Indonesia, there are numerous traditional herbal preparations for treatment of infectious diseases. However, their antimicrobial potential has been poorly studied by modern laboratory methods. This study investigates in vitro antimicrobial activity of 49 ethanol extracts from 37 plant species used in Indonesian traditional medicine for treatment against Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The plants were collected from the Biopharmaca collection garden, Bogor, Indonesia. The plant material was dried, finely grounded, extracted using ethanol, concentrated, and the dried residue was dissolved in 100% DMSO. Antimicrobial activity was determined in terms of a minimum inhibitory concentration (MIC) using a broth microdilution method in 96-well microplates. The extract of Orthosiphon aristatus (Blume) Miq. (Lamiaceae) leaf produced the strongest antimicrobial effect, inhibiting the growth of C. albicans (MIC 128 μg/mL), S. aureus (MIC 256 μg/mL), E. faecalis (MIC 256 μg/mL) and P. aeruginosa (MIC 256 μg/mL). The leaf extract of Woodfordia floribunda Salisb. (Lythraceae) also exhibited significant effect against C. albicans (MIC 128 μg/mL), S. aureus (MIC 256 μg/mL) and E. faecalis (MIC 256 μg/mL). Rotheca serrata (L.) Steane & Mabb. (Lamiaceae) leaf extract inhibited the growth of S. aureus (MIC 256 µg/mL) and C. albicans (MIC 256 µg/mL). The leaf extract of O. aristatus and W. floribunda exhibited a significant anti-candidal effect. Therefore, both of these plants can serve as prospective source materials for the development of new anti-candidal agents.

  17. Diversity of fecal coliforms and their antimicrobial resistance patterns in wastewater treatment model plant.

    Science.gov (United States)

    Luczkiewicz, A; Fudala-Ksiazek, S; Jankowska, K; Quant, B; Olańczuk-Neyman, K

    2010-01-01

    The occurrence of resistance patterns among wastewater fecal coliforms was determined in the study. Susceptibility of the isolates was tested against 19 antimicrobial agents: aminoglycosides, aztreonam, carbapenems, cephalosporines, beta-lactam/beta-lactamase inhibitors, penicillines, tetracycline, trimethoprim/sulfamethoxazole, and fluoroquinolones. Additionally the removal of resistant isolates was evaluated in the laboratory-scale wastewater treatment model plant (M-WWTP), continuously supplied with the wastewater obtained from the full-scale WWTP. Number of fecal coliforms in raw (after mechanical treatment) and treated wastewater, as well as in aerobic chamber effluent was determined using selective medium. The selected strains were identified and examined for antibiotic resistance using Phoenix Automated Microbiology System (BD Biosciences, USA). The strains were identified as Escherichia coli (n=222), Klebsiella pneumoniae ssp. ozaenae (n=9), and Pantoea agglomerans (n=1). The isolate of P. agglomerans as well as 48% of E. coli isolates were sensitive to all antimicrobials tested. The most frequent resistance patterns were found for ampicillin: 100% of K. pneumoniae ssp. ozaenae and 41% of E. coli isolates. Among E. coli isolates 12% was regarded as multiple antimicrobial resistant (MAR). In the studied M-WWTP, the applied activated sludge processes reduced considerably the number of fecal coliforms, but increased the ratio of antimicrobial-resistant E. coli isolates to sensitive ones, especially among strains with MAR patterns.

  18. Inhibitory effects of antimicrobial agents against Fusarium species.

    Science.gov (United States)

    Kawakami, Hideaki; Inuzuka, Hiroko; Hori, Nobuhide; Takahashi, Nobumichi; Ishida, Kyoko; Mochizuki, Kiyofumi; Ohkusu, Kiyofumi; Muraosa, Yasunori; Watanabe, Akira; Kamei, Katsuhiko

    2015-08-01

    We investigated the inhibitory effects of antibacterial, biocidal, and antifungal agents against Fusarium spp. Seven Fusarium spp: four F. falciforme (Fusarium solani species complex), one Fusarium spp, one Fusarium spp. (Fusarium incarnatum-equiseti species complex), and one F. napiforme (Gibberella fujikuroi species complex), isolated from eyes with fungal keratitis were used in this study. Their susceptibility to antibacterial agents: flomoxef, imipenem, gatifloxacin, levofloxacin, moxifloxacin, gentamicin, tobramycin, and Tobracin® (contained 3,000 μg/ml of tobramycin and 25 μg/ml of benzalkonium chloride (BAK), a biocidal agent: BAK, and antifungal agents: amphotericin B, pimaricin (natamycin), fluconazole, itraconazole, miconazole, voriconazole, and micafungin, was determined by broth microdilution tests. The half-maximal inhibitory concentration (IC50), 100% inhibitory concentration (IC100), and minimum inhibitory concentration (MIC) against the Fusarium isolates were determined. BAK had the highest activity against the Fusarium spp. except for the antifungal agents. Three fluoroquinolones and two aminoglycosides had inhibitory effects against the Fusarium spp. at relatively high concentrations. Tobracin® had a higher inhibitory effect against Fusarium spp. than tobramycin alone. Amphotericin B had the highest inhibitory effect against the Fusarium spp, although it had different degrees of activity against each isolate. Our findings showed that fluoroquinolones, aminoglycosides, and BAK had some degree of inhibitory effect against the seven Fusarium isolates, although these agents had considerably lower effect than amphotericin B. However, the inhibitory effects of amphotericin B against the Fusarium spp. varied for the different isolates. Further studies for more effective medications against Fusarium, such as different combinations of antibacterial, biocidal, and antifungal agents are needed. © The Author 2015. Published by Oxford University Press on

  19. Clemastine as Antimicrobial Agent: Effectiveness and Mechanism of Action

    Directory of Open Access Journals (Sweden)

    S.Fazli Bazaz

    1991-07-01

    Full Text Available In this investigation, the antimicrobial activity of Clemastine was studied.The Minimum Inhibitory Concentrations (MICs of this drug against some bacteria were determined using tube dilution method.To find out the bactericidal activity of Clemastine, the number of living bacteria in the presence of drug was counted by a culture method (pour plate method. Thereafter, the preservative effectiveness of Clemastine was studied in detail using standard method (USP 1985.The results show a good antibacterial but not antifungal activity."nIn considering the mechanism of action of Clemastine, it can be seen that the drug has some effect on cell membrane permeability and causes leakage of intracellular material including the K+ .Comparing the bactericidal results with the leakage of K+, shows that the leakage may be due to the bactericidal activity of the drug.

  20. Antimicrobial Activities of Three Medicinal Plants and Investigation of Flavonoids of Tripleurospermum disciforme.

    Science.gov (United States)

    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.

  1. Animals living in polluted environments are potential source of antimicrobials against infectious agents

    Science.gov (United States)

    Lee, Simon; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2012-01-01

    The antimicrobials crisis is a ticking time bomb which could lead to millions of people dying from untreatable infections. With the worsening trends of antimicrobial resistance, we are heading towards a pre-antibiotic era. Thus, there is a need for newer and more powerful antibiotic agents. The search for new antibiotic compounds originating from natural resources is a promising research area. Animals living in germ-infested environments are a potent source of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of bacteria, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances which show potent activity in the nervous system. We hope that the discovery of antimicrobial activity in the cockroach brain will stimulate research in finding antimicrobials from unusual sources, and has potential for the development of novel antibiotics. Nevertheless, intensive research in the next few years will be required to approach or realize these expectations. PMID:23265422

  2. Metabolic network analysis-based identification of antimicrobial drug targets in category A bioterrorism agents.

    Directory of Open Access Journals (Sweden)

    Yong-Yeol Ahn

    Full Text Available The 2001 anthrax mail attacks in the United States demonstrated the potential threat of bioterrorism, hence driving the need to develop sophisticated treatment and diagnostic protocols to counter biological warfare. Here, by performing flux balance analyses on the fully-annotated metabolic networks of multiple, whole genome-sequenced bacterial strains, we have identified a large number of metabolic enzymes as potential drug targets for each of the three Category A-designated bioterrorism agents including Bacillus anthracis, Francisella tularensis and Yersinia pestis. Nine metabolic enzymes- belonging to the coenzyme A, folate, phosphatidyl-ethanolamine and nucleic acid pathways common to all strains across the three distinct genera were identified as targets. Antimicrobial agents against some of these enzymes are available. Thus, a combination of cross species-specific antibiotics and common antimicrobials against shared targets may represent a useful combinatorial therapeutic approach against all Category A bioterrorism agents.

  3. Synthesis of modified pyridine and bipyridine substituted coumarins as potent antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Lad Hemali B.

    2015-01-01

    Full Text Available In search for new antimicrobial agents a series of new modified pyridine and bipyridine substituted coumarins 5a-y was designed and synthesized by adopting molecular hybridization strategy. All the synthesized compounds were evaluated for their in vitro antimicrobial activity using broth dilution method against selected bacterial (Gram-positive and Gram-negative and fungal strains. Compounds 5a, 5f, 5g, 5n, 5r, 5t, 5w, 5x and 5y demonstrated promising antibacterial activity while other derivatives showed comparable activity to standard drugs used as reference.

  4. Survey of metals on antimicrobial and deodorant agents in household Necessities; Mukikei kokinsei kakoseihin no shiyojittai

    Energy Technology Data Exchange (ETDEWEB)

    Kan, Teruo

    1999-11-01

    It measured the metal bearing quantity in household necessities in order to clarify use actual condition of the metal system drug. And, it tried the detection of the drug used from detected metal. Too there is the report until now in the investigation of the metallic element in household necessities. However, metals examined this time are silver and zinc, four of copper and aluminum that it says that it has the antimicrobial action and is Key element of inorganic system antimicrobial agent. And, it carried out the analysis by inductive coupling plasma emission analysis method, after the wet digestion of the sample was done. (NEDO)

  5. Susceptibilities of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum strains to antimicrobial agents in vitro.

    Science.gov (United States)

    ter Laak, E A; Noordergraaf, J H; Verschure, M H

    1993-02-01

    The purpose of this study was to determine the susceptibility of various strains of Mycoplasma bovis, Mycoplasma dispar, and Ureaplasma diversum, which are prevalent causes of pneumonia in calves, to 16 antimicrobial agents in vitro. The MICs of the antimicrobial agents were determined by a serial broth dilution method for 16 field strains and the type strain of M. bovis, for 19 field strains and the type strain of M. dispar, and for 17 field strains of U. diversum. Final MICs for M. bovis and M. dispar were read after 7 days and final MICs for U. diversum after 1 to 2 days. All strains tested were susceptible to tylosin, kitasamycin, and tiamulin but were resistant to nifuroquine and streptomycin. Most strains of U. diversum were intermediately susceptible to oxytetracycline but fully susceptible to chlortetracycline; most strains of M. bovis and M. dispar, however, were resistant to both agents. Strains of M. dispar and U. diversum were susceptible to doxycycline and minocycline, but strains of M. bovis were only intermediately susceptible. Susceptibility or resistance to chloramphenicol, spiramycin, spectinomycin, lincomycin, or enrofloxacin depended on the species but was not equal for the three species. The type strains of M. bovis and M. dispar were more susceptible to various antimicrobial agents, including tetracyclines, than the field strains. This finding might indicate that M. bovis and M. dispar strains are becoming resistant to these agents. Antimicrobial agents that are effective in vitro against all three mycoplasma species can be considered for treating mycoplasma infections in pneumonic calves. Therefore, tylosin, kitasamycin, and tiamulin may be preferred over oxytetracycline and chlortetracycline.

  6. Antioxidant, antimicrobial, antitumor, and cytotoxic activities of an important medicinal plant (Euphorbia royleana from Pakistan

    Directory of Open Access Journals (Sweden)

    Aisha Ashraf

    2015-03-01

    Full Text Available The aim of present study was to evaluate antioxidant, antimicrobial, and antitumor activities of methanol, hexane, and aqueous extracts of fresh Euphorbia royleana. Total phenolic and flavonoid contents were estimated as gallic acid and querectin equivalents, respectively. Antioxidant activity was assessed by scavenging of free 2,2′- diphenyl-1-picrylhydrazyl radicals and reduction of ferric ions, and it was observed that inhibition values increase linearly with increase in concentration of extract. The results of ferric reducing antioxidant power assay showed that hexane extract has maximum ferric reducing power (12.70 ± 0.49 mg gallic acid equivalents/g of plant extract. Maximum phenolic (47.47 ± 0.71 μg gallic acid equivalents/mg of plant extract and flavonoid (63.68 ± 0.43 μg querectin equivalents/mg of plant extract contents were also found in the hexane extract. Furthermore, we examined antimicrobial activity of the three extracts (methanol, hexane, aqueous against a panel of microorganisms (Escherichia coli, Bacillus subtillis, Pasteurella multocida, Aspergillus niger, and Fusarium solani by disc-diffusion assay, and found the hexane extract to be the best antimicrobial agent. Hexane extract was also observed as to be most effective in a potato disc assay. As hexane extract showed potent activity in all the investigated assays, it was targeted for cytotoxic assessment. Maximum cytotoxicity (61.66% by hexane extract was found at 800 μg/mL. It is concluded that investigated extracts have potential for isolation of antioxidant and antimicrobial compounds for the pharmaceutical industry.

  7. Preliminary screening of some traditional zulu medicinal plants for anti-inflammatory and anti-microbial activities.

    Science.gov (United States)

    Lin, J; Opoku, A R; Geheeb-Keller, M; Hutchings, A D; Terblanche, S E; Jäger, A K; van Staden, J

    1999-12-15

    Aqueous and methanolic extracts from different parts of nine traditional Zulu medicinal plants, of the Vitaceae from KwaZulu-Natal, South Africa were evaluated for therapeutic potential as anti-inflammatory and anti-microbial agents. Of the twenty-nine crude extracts assayed for prostaglandin synthesis inhibitors, only five methanolic extracts of Cyphostemma natalitium-root, Rhoicissus digitata-leaf, R. rhomboidea-root, R. tomentosa-leaf/stem and R. tridentata-root showed significant inhibition of cyclo-oxygenase (COX-1). The extracts of R. digitata-leaf and of R. rhomboidea-root exhibited the highest inhibition of prostaglandin synthesis with 53 and 56%, respectively. The results suggest that Rhoicissus digitata leaves and of Rhoicissus rhomboidea roots may have the potential to be used as anti-inflammatory agents. All the screened plant extracts showed some degrees of anti-microbial activity against gram-positive and gram-negative microorganisms. The methanolic extracts of C. natalitium-stem and root, R. rhomboidea-root, and R. tomentosa-leaf/stem, showed different anti-microbial activities against almost all micro-organisms tested. Generally, these plant extracts inhibited the gram-positive micro-organisms more than the gram-negative ones. Several plant extracts inhibited the growth of Candida albicans while only one plant extract showed inhibitory activity against Saccharomyces cerevisiae. All the plant extracts which demonstrated good anti-inflammatory activities also showed better inhibitory activity against Candida albicans.

  8. Synthesis of 2-phenylamino-thiazole derivatives as antimicrobial agents

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    Dominique Serge Ngono Bikobo

    2017-11-01

    Full Text Available A series of 10 new N-phenyl-4-(4-(thiazol-2-yl-phenyl-thiazol-2-amine derivatives (3a–j and 4 new 5-(2-(phenylamino-thiazol-4-yl-benzamide ethers (3′a–d were synthesized from 4-(2-phenylamino-thiazol-4-yl-benzothioamide and 2-hydroxy-5-(2-(phenylamino-thiazol-4-yl-benzamide with several α-halo-ketones, by the Hantzsch reaction. All compounds were characterized by elemental analysis and spectral data (MS, FT-IR and NMR. The final 14 substances were screened for antimicrobial activity, against two Gram-positive, one Gram-negative bacterial strains, and two fungal strains. Some of the synthesized molecules were more potent than the reference drugs, against the pathogenic strains used. The antibacterial activity of compounds was more pronounced against the Gram-positive strains. Compound 3e manifested the highest growth inhibitory effect against all pathogens tested (MIC of 31.25 μg/mL against the Gram-positive bacterial strains and 7.81 μg/mL against the Candida strains.

  9. Antimicrobial Resistance and the Alternative Resources with Special Emphasis on Plant-Based Antimicrobials—A Review

    Directory of Open Access Journals (Sweden)

    Harish Chandra

    2017-04-01

    Full Text Available Indiscriminate and irrational use of antibiotics has created an unprecedented challenge for human civilization due to microbe’s development of antimicrobial resistance. It is difficult to treat bacterial infection due to bacteria’s ability to develop resistance against antimicrobial agents. Antimicrobial agents are categorized according to their mechanism of action, i.e., interference with cell wall synthesis, DNA and RNA synthesis, lysis of the bacterial membrane, inhibition of protein synthesis, inhibition of metabolic pathways, etc. Bacteria may become resistant by antibiotic inactivation, target modification, efflux pump and plasmidic efflux. Currently, the clinically available treatment is not effective against the antibiotic resistance developed by some bacterial species. However, plant-based antimicrobials have immense potential to combat bacterial, fungal, protozoal and viral diseases without any known side effects. Such plant metabolites include quinines, alkaloids, lectins, polypeptides, flavones, flavonoids, flavonols, coumarin, terpenoids, essential oils and tannins. The present review focuses on antibiotic resistance, the resistance mechanism in bacteria against antibiotics and the role of plant-active secondary metabolites against microorganisms, which might be useful as an alternative and effective strategy to break the resistance among microbes.

  10. Common errors in the treatment of intra-abdominal infections: the irrational use of antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Belinda De Simone

    2016-06-01

    Full Text Available Antimicrobial resistance (AR is a global, emergent problem because an increasing numbers of serious community acquired and nosocomial infections are caused by resistant bacterial pathogens. It is a direct consequence of the excessive and irrational use of antibiotics. The use of antimicrobial agents – aimed to decrease morbidity and mortality rate related to intra-abdominal infections – is very high, often improper, in the Departments of General and Emergency Surgery and Intensive Cure Units. Source control and empiric antibiotic therapy have to be administrated as early as possible to decrease high mortality rates in patients with severe sepsis or septic shock and, in this, the general surgeon has a crucial role. Proper antimicrobial stewardship in selecting an appropriate antibiotic and optimizing its dose and duration to cure intraabdominal infections may prevent the emergence of AR and decrease costs for antibiotics.

  11. Repurposing Auranofin, Ebselen, and PX-12 as Antimicrobial Agents Targeting the Thioredoxin System

    Directory of Open Access Journals (Sweden)

    Holly C. May

    2018-03-01

    Full Text Available As microbial resistance to drugs continues to rise at an alarming rate, finding new ways to combat pathogens is an issue of utmost importance. Development of novel and specific antimicrobial drugs is a time-consuming and expensive process. However, the re-purposing of previously tested and/or approved drugs could be a feasible way to circumvent this long and costly process. In this review, we evaluate the U.S. Food and Drug Administration tested drugs auranofin, ebselen, and PX-12 as antimicrobial agents targeting the thioredoxin system. These drugs have been shown to act on bacterial, fungal, protozoan, and helminth pathogens without significant toxicity to the host. We propose that the thioredoxin system could serve as a useful therapeutic target with broad spectrum antimicrobial activity.

  12. Nanosilver: Potent antimicrobial agent and its biosynthesis | Sarsar ...

    African Journals Online (AJOL)

    The synthesis of silver nanoparticles has been reported using chemical and physical methods. This review describes a cost effective and ecofriendly approach for the synthesis of silver nanoparticles. Thus, in this review we focus on the role of microorganisms and plants in the synthesis of nanosilver and their potent ...

  13. Insights into Animal and Plant Lectins with Antimicrobial Activities

    Directory of Open Access Journals (Sweden)

    Renata de Oliveira Dias

    2015-01-01

    Full Text Available Lectins are multivalent proteins with the ability to recognize and bind diverse carbohydrate structures. The glyco -binding and diverse molecular structures observed in these protein classes make them a large and heterogeneous group with a wide range of biological activities in microorganisms, animals and plants. Lectins from plants and animals are commonly used in direct defense against pathogens and in immune regulation. This review focuses on sources of animal and plant lectins, describing their functional classification and tridimensional structures, relating these properties with biotechnological purposes, including antimicrobial activities. In summary, this work focuses on structural-functional elucidation of diverse lectin groups, shedding some light on host-pathogen interactions; it also examines their emergence as biotechnological tools through gene manipulation and development of new drugs.

  14. Antimicrobial activity of Eucalyptus camaldulensis essential oils and their interactions with conventional antimicrobial agents against multi-drug resistant Acinetobacter baumannii.

    Science.gov (United States)

    Knezevic, Petar; Aleksic, Verica; Simin, Natasa; Svircev, Emilija; Petrovic, Aleksandra; Mimica-Dukic, Neda

    2016-02-03

    Traditional herbal medicine has become an important issue on the global scale during the past decade. Among drugs of natural origin, special place belongs to essential oils, known as strong antimicrobial agents that can be used to combat antibiotic-resistant bacteria. Eucalyptus camaldulensis leaves are traditional herbal remedy used for various purposes, including treatment of infections. The aim of this study was to determine antimicrobial potential of two E. camaldulensis essential oils against multi-drug resistant (MDR) Acinetobacter baumannii wound isolates and to examine possible interactions of essential oils with conventional antimicrobial agents. Chemical composition of essential oils was determined by gas chromatography-mass spectrometry analysis (GC-MS). MIC values of essential oils against A. baumannii strains were estimated by modified broth microdilution method. The components responsible for antimicrobial activity were detected by bioautographic analysis. The potential synergy between the essential oils and antibiotics (ciprofloxacin, gentamicin and polymyxin B) was examined by checkerboard method and time kill curve. The dominant components of both essential oils were spatulenol, cryptone, p-cimene, 1,8-cineole, terpinen-4-ol and β-pinene. The detected MICs for the E. camaldulensis essential oils were in range from 0.5 to 2 μl mL(-1). The bioautographic assay confirmed antibacterial activity of polar terpene compounds. In combination with conventional antibiotics (ciprofloxacin, gentamicin and polymyxin B), the examined essential oils showed synergistic antibacterial effect in most of the cases, while in some even re-sensitized MDR A. baumannii strains. The synergistic interaction was confirmed by time-kill curves for E. camaldulensis essential oil and polymyxin B combination which reduced bacterial count under detection limit very fast, i.e. after 6h of incubation. The detected anti-A. baumannii activity of E. camaldulensis essential oils

  15. High-Level Antimicrobial Efficacy of Representative Mediterranean Natural Plant Extracts against Oral Microorganisms

    Directory of Open Access Journals (Sweden)

    Lamprini Karygianni

    2014-01-01

    Full Text Available Nature is an unexplored reservoir of novel phytopharmaceuticals. Since biofilm-related oral diseases often correlate with antibiotic resistance, plant-derived antimicrobial agents could enhance existing treatment options. Therefore, the rationale of the present report was to examine the antimicrobial impact of Mediterranean natural extracts on oral microorganisms. Five different extracts from Olea europaea, mastic gum, and Inula viscosa were tested against ten bacteria and one Candida albicans strain. The extraction protocols were conducted according to established experimental procedures. Two antimicrobial assays—the minimum inhibitory concentration (MIC assay and the minimum bactericidal concentration (MBC assay—were applied. The screened extracts were found to be active against each of the tested microorganisms. O. europaea presented MIC and MBC ranges of 0.07–10.00 mg mL−1 and 0.60–10.00 mg mL−1, respectively. The mean MBC values for mastic gum and I. viscosa were 0.07–10.00 mg mL−1 and 0.15–10.00 mg mL−1, respectively. Extracts were less effective against C. albicans and exerted bactericidal effects at a concentration range of 0.07–5.00 mg mL−1 on strict anaerobic bacteria (Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Parvimonas micra. Ethyl acetate I. viscosa extract and total mastic extract showed considerable antimicrobial activity against oral microorganisms and could therefore be considered as alternative natural anti-infectious agents.

  16. In vitro antimicrobial activity of ten medicinal plants against clinical isolates of oral cancer cases

    Directory of Open Access Journals (Sweden)

    Kaushal Vivek

    2011-05-01

    . communis and T. foenum graecum showed significant antimicrobial activity (P P. aeruginosa was observed highest susceptible bacteria (46.6% on the basis of susceptible index. Conclusion It can be concluded that treated oral cancer patients were neutropenic and prone to secondary infection of microbes. The medicinal plant can prove as effective antimicrobial agent to check the secondary infections in treated cancer patients.

  17. Patterns of antimicrobial agent prescription in a sentinel population of canine and feline veterinary practices in the United Kingdom.

    Science.gov (United States)

    Singleton, D A; Sánchez-Vizcaíno, F; Dawson, S; Jones, P H; Noble, P J M; Pinchbeck, G L; Williams, N J; Radford, A D

    2017-06-01

    Antimicrobial resistance is an increasingly important global health threat and the use of antimicrobial agents is a key risk factor in its development. This study describes antimicrobial agent prescription (AAP) patterns over a 2year period using electronic health records (EHRs) from booked consultations in a network of 457 sentinel veterinary premises in the United Kingdom. A semi-automated classification methodology was used to map practitioner defined product codes in 918,333 EHRs from 413,870 dogs and 352,730 EHRs from 200,541 cats, including 289,789 AAPs. AAP as a proportion of total booked consultations was more frequent in dogs (18.8%, 95% confidence interval, CI, 18.2-19.4) than cats (17.5%, 95% CI 16.9-18.1). Prescription of topical antimicrobial agents was more frequent in dogs (7.4%, 95% CI 7.2-7.7) than cats (3.2%, 95% CI 3.1-3.3), whilst prescription of systemic antimicrobial agents was more frequent in cats (14.8%, 95% CI 14.2-15.4) than dogs (12.2%, 95% CI 11.7-12.7). A decreasing temporal pattern was identified for prescription of systemic antimicrobial agents in dogs and cats. Premises which prescribed antimicrobial agents frequently for dogs also prescribed frequently for cats. AAP was most frequent during pruritus consultations in dogs and trauma consultations in cats. Clavulanic acid potentiated amoxicillin was the most frequently prescribed antimicrobial agent in dogs (28.6% of prescriptions, 95% CI 27.4-29.8), whereas cefovecin, a third generation cephalosporin, was the most frequently prescribed antimicrobial agent in cats (36.2%, 95% CI 33.9-38.5). This study demonstrated patterns in AAP over time and for different conditions in a population of companion animals in the United Kingdom. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  18. Engineered Chimeric Peptides as Antimicrobial Surface Coating Agents toward Infection-Free Implants.

    Science.gov (United States)

    Yazici, Hilal; O'Neill, Mary B; Kacar, Turgay; Wilson, Brandon R; Oren, E Emre; Sarikaya, Mehmet; Tamerler, Candan

    2016-03-02

    Prevention of bacterial colonization and consequent biofilm formation remains a major challenge in implantable medical devices. Implant-associated infections are not only a major cause of implant failures but also their conventional treatment with antibiotics brings further complications due to the escalation in multidrug resistance to a variety of bacterial species. Owing to their unique properties, antimicrobial peptides (AMPs) have gained significant attention as effective agents to combat colonization of microorganisms. These peptides have been shown to exhibit a wide spectrum of activities with specificity to a target cell while having a low tendency for developing bacterial resistance. Engineering biomaterial surfaces that feature AMP properties, therefore, offer a promising approach to prevent implant infections. Here, we engineered a chimeric peptide with bifunctionality that both forms a robust solid-surface coating while presenting antimicrobial property. The individual domains of the chimeric peptides were evaluated for their solid-binding kinetics to titanium substrate as well as for their antimicrobial properties in solution. The antimicrobial efficacy of the chimeric peptide on the implant material was evaluated in vitro against infection by a variety of bacteria, including Streptococcus mutans, Staphylococcus. epidermidis, and Escherichia coli, which are commonly found in oral and orthopedic implant related surgeries. Our results demonstrate significant improvement in reducing bacterial colonization onto titanium surfaces below the detectable limit. Engineered chimeric peptides with freely displayed antimicrobial domains could be a potential solution for developing infection-free surfaces by engineering implant interfaces with highly reduced bacterial colonization property.

  19. Metal oxide nanoparticles as antimicrobial agents: a promise for the future.

    Science.gov (United States)

    Raghunath, Azhwar; Perumal, Ekambaram

    2017-02-01

    Microbial infectious diseases are a global threat to human health. Excess and improper use of antibiotics has created antimicrobial-resistant microbes that can defy clinical treatment. The hunt for safe and alternate antimicrobial agents is on in order to overcome such resistant micro-organisms, and the birth of nanotechnology offers promise to combat infectious organisms. Over the past two decades, metal oxide nanoparticles (MeO-NPs) have become an attractive alternative source to combat microbes that are highly resistant to various classes of antibiotics. Their vast array of physicochemical properties enables MeO-NPs to act as antimicrobial agents through various mechanisms. Apart from exhibiting antimicrobial properties, MeO-NPs also serve as carriers of drugs, thus barely providing a chance for micro-organisms to develop resistance. These immense multiple properties exhibited by MeO-NPs will have an impact on the treatment of deadly infectious diseases. This review discusses the mechanisms of action of MeO-NPs against micro-organisms, safety concerns, challenges and future perspectives. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  20. Effect of ionizing energy on extracts of Quillaja saponaria to be used as an antimicrobial agent on irradiated edible coating for fresh strawberries

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga, G.E., E-mail: gustavo.zuniga@usach.cl [Universidad de Santiago de Chile (USACH), Facultad de Quimica y Biologia, Depto. de Biologia, Alameda 3363, Estacion Central, Santiago (Chile); Junqueira-Goncalves, M.P., E-mail: mpaula.junqueira@usach.cl [Universidad de Santiago de Chile (USACH), Facultad Tecnologica, Depto. de Ciencia y Tecnologia de Alimentos, Ecuador 3769, Estacion Central, Santiago (Chile); Pizarro, M.; Contreras, R. [Universidad de Santiago de Chile (USACH), Facultad de Quimica y Biologia, Depto. de Biologia, Alameda 3363, Estacion Central, Santiago (Chile); Tapia, A. [Universidad de Santiago de Chile (USACH), Facultad Tecnologica, Depto. de Ciencia y Tecnologia de Alimentos, Ecuador 3769, Estacion Central, Santiago (Chile); Silva, S. [Comision Chilena de Energia Nuclear, Depto. de Aplicaciones Nucleares, Seccion Salud y Alimentos, La Reina, Santiago (Chile)

    2012-01-15

    Incorporating antimicrobial compounds into edible films or coatings provides a novel way to improve the safety and shelf life of ready-to-eat foods. Diverse studies with Quillaja saponaria Mol. (popularly named quillay) extracts have demonstrated their potential as antifungal agents against phytopathogenic fungi. Crosslinking induced by ionizing radiation is an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on milk proteins. However there are few reports about the effects of {gamma}-radiation on plant extracts. The aim of this work was to evaluate the effect of ionizing radiation (0, 5, 10, 15, 20, 25 and 35 kGy) on extracts prepared from in vitro plants of Q. saponaria to be used as antimicrobial agent in irradiated edible coating based on calcium caseinate and whey protein isolated, and also to establish the concentration of Q. saponaria extract to be added as an antifungal agent in the coating. Gamma irradiation since 15 kGy affects negatively the antimicrobial activity and metabolites composition of extract of Q. saponaria by reducing compounds of phenolic nature. Otherwise no effect on saponins profile was observed even at higher doses. It was possible to conclude that the antifungal activity of Q. saponaria extract is mainly related to phenolic compounds content. In addition, our work also shows that to obtain an efficient antifungal protection is necessary to add a minimum concentration of 6% of the extract after the coating irradiation. - Highlights: > Antimicrobial compounds into edible coatings improve food' safety and shelf life. > Q. saponaria extract is an antifungal agent against phytopathogenic fungi. > Crosslinking induced by {gamma}-radiation over 30 kGy improves properties of the coatings. > {gamma}-radiation since 15 kGy affects the antimicrobial activity of Q. saponaria extract. > This extract should be added after the coating radiation, at a minimum of 6%.

  1. Effect of ionizing energy on extracts of Quillaja saponaria to be used as an antimicrobial agent on irradiated edible coating for fresh strawberries

    International Nuclear Information System (INIS)

    Zuniga, G.E.; Junqueira-Goncalves, M.P.; Pizarro, M.; Contreras, R.; Tapia, A.; Silva, S.

    2012-01-01

    Incorporating antimicrobial compounds into edible films or coatings provides a novel way to improve the safety and shelf life of ready-to-eat foods. Diverse studies with Quillaja saponaria Mol. (popularly named quillay) extracts have demonstrated their potential as antifungal agents against phytopathogenic fungi. Crosslinking induced by ionizing radiation is an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on milk proteins. However there are few reports about the effects of γ-radiation on plant extracts. The aim of this work was to evaluate the effect of ionizing radiation (0, 5, 10, 15, 20, 25 and 35 kGy) on extracts prepared from in vitro plants of Q. saponaria to be used as antimicrobial agent in irradiated edible coating based on calcium caseinate and whey protein isolated, and also to establish the concentration of Q. saponaria extract to be added as an antifungal agent in the coating. Gamma irradiation since 15 kGy affects negatively the antimicrobial activity and metabolites composition of extract of Q. saponaria by reducing compounds of phenolic nature. Otherwise no effect on saponins profile was observed even at higher doses. It was possible to conclude that the antifungal activity of Q. saponaria extract is mainly related to phenolic compounds content. In addition, our work also shows that to obtain an efficient antifungal protection is necessary to add a minimum concentration of 6% of the extract after the coating irradiation. - Highlights: → Antimicrobial compounds into edible coatings improve food' safety and shelf life. → Q. saponaria extract is an antifungal agent against phytopathogenic fungi. → Crosslinking induced by γ-radiation over 30 kGy improves properties of the coatings. → γ-radiation since 15 kGy affects the antimicrobial activity of Q. saponaria extract. → This extract should be added after the coating radiation, at a minimum of 6%.

  2. Development of membranes of PLGA functionalized with antimicrobial agents nanostructured

    International Nuclear Information System (INIS)

    Souza, S.G.; Molin, M.L.A.L.; Nogueira, A.L.; Schneider, E. Duek; Pezzin, A.P.T.

    2016-01-01

    Periodontitis is a disease affecting the tooth supporting tissues, causing loss of bone attachment. One of the possible treatments is through guided tissue regeneration (GTR). Currently, a variety of resorbable membranes are available as alternative to conventional non-resorbable membranes for this application, as the membranes of poly (lactic acid-co-glycolic acid) (PLGA). In this context, this study aimed to produce membranes were biocompatible and nanostructured functionalized with antibacterial agents and evaluate its thermal properties for future application in RTG. For the production of membranes were used as the PLGA polymer matrix. The NpAg were used at concentrations of 5, 7, 8 and 10 ppm and NpZnO were: 10, 50, 100 and 150 ppm. The materials were characterized by TGA and DSC. (author)

  3. Trends and Sources of Zoonoses, Zoonotic Agents and Antimicrobial resistance in the European Union in 2004

    DEFF Research Database (Denmark)

    Helwigh, Birgitte

    EFSA's Community Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Antimicrobial resistance in the European Union in 2004 was published in December 2005. The zoonoses, meaning infectious diseases transmissible from animals to humans, affected over 380,000 EU citizens in 2004....... Often the human form of the disease is acquired through contaminated food. According to the report, the two most frequently reported zoonotic diseases in humans were Salmonella and Campylobacter infections. These bacteria were also commonly found in food and animals. The report includes information...... of 11 zoonoses, antimicrobial resistance in zoonotic agents as well as foodborne outbreaks. The national zoonoses country reports which have been used as a basis for this Summary report are below. The utmost effort was made to keep the information in the Summary Report and the national reports identical...

  4. Polymeric nanoparticles – a novel solution for delivery of antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Grzegorz Michalak

    2016-04-01

    Full Text Available The increased prevalence of antibiotic-resistant pathogens requires additional efforts to develop new antimicrobial agents and alternative methods to prevent and treat infections. In response to this challenge, a variety of nanotechnology-based tools are currently being designed and thoroughly investigated. To date, a considerable number of studies have reported increased activity of antibiotic-conjugated polymeric nanoparticles against bacteria and fungi associated with various infections, including those caused by drug-resistant pathogens. Importantly, high biocompatibility of these structures coupled with enhanced biological activity and improved pharmacokinetic properties supports the potential of these nanosystems as new tools to treat infections. In this review, we summarize the synthesis of polymer-based nanoparticles and describe their mechanism of action. We also highlight the recent advances in the application of antibiotic-conjugated polymeric nanoparticles as novel antimicrobial agents.

  5. Plants' Metabolites as Potential Antiobesity Agents

    Directory of Open Access Journals (Sweden)

    Najla Gooda Sahib

    2012-01-01

    Full Text Available Obesity and obesity-related complications are on the increase both in the developed and developing world. Since existing pharmaceuticals fail to come up with long-term solutions to address this issue, there is an ever-pressing need to find and develop new drugs and alternatives. Natural products, particularly medicinal plants, are believed to harbor potential antiobesity agents that can act through various mechanisms either by preventing weight gain or promoting weight loss amongst others. The inhibition of key lipid and carbohydrate hydrolyzing and metabolizing enzymes, disruption of adipogenesis, and modulation of its factors or appetite suppression are some of the plethora of targeted approaches to probe the antiobesity potential of medicinal plants. A new technology such as metabolomics, which deals with the study of the whole metabolome, has been identified to be a promising technique to probe the progression of diseases, elucidate their pathologies, and assess the effects of natural health products on certain pathological conditions. This has been applied to drug research, bone health, and to a limited extent to obesity research. This paper thus endeavors to give an overview of those plants, which have been reported to have antiobesity effects and highlight the potential and relevance of metabolomics in obesity research.

  6. Comparison of methods for in vitro testing of susceptibility of porcine Mycoplasma species to antimicrobial agents.

    OpenAIRE

    Ter Laak, E A; Pijpers, A; Noordergraaf, J H; Schoevers, E C; Verheijden, J H

    1991-01-01

    The MICs of 18 antimicrobial agents used against strains of three porcine Mycoplasma species were determined by a serial broth dilution method. Twenty field strains of M. hyorhinis, ten field strains of M. hyopneumoniae, six field strains of M. flocculare, and the type strains of these species were tested. Twelve field strains and the type strain of M. hyorhinis were also tested by an agar dilution method. Tests were read at various time points. When the broth dilution method was used, the fi...

  7. Novel natural food antimicrobials.

    Science.gov (United States)

    Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

    2012-01-01

    Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

  8. Evaluation of antimicrobial activity of selected plant extracts by rapid XTT colorimetry and bacterial enumeration.

    Science.gov (United States)

    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.

  9. Antimicrobial activity of disinfectant agents incorporated into type IV dental stone.

    Science.gov (United States)

    Pereira, Rodrigo de Paula; Lucas, Matheus Guilherme; Spolidorio, Denise Madalena Palomari; Arioli Filho, João Neudenir

    2012-06-01

    This study evaluated the antimicrobial activity of two disinfectant agents, 2% chlorhexidine digluconate solution (CHX) and 98% chlorhexidine hydrochloride powder (HYD), incorporated into type IV dental stone at the time of mixing. Agar diffusion test was used for the following microorganisms: Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Candida albicans. The specimens were grouped in: (1) dental stone mixed with sterile distilled water; (2) paper disc soaked with CHX; (3) dental stone mixed with CHX; and (4) dental stone with incorporation of HYD, in 1% proportion of the dental stone mass and mixed with sterile distilled water. The culture medium was inoculated with microbial suspensions 1 and 24 h after pouring of the dental stone. The antimicrobial activity was evaluated by the average diameter of microbial growth inhibition zones. The data were analysed with a nested anova (p < 0.05) and Tukey test for specific comparisons. The disinfectant agents demonstrated antimicrobial activity against all microorganisms, with the exception of C. albicans, against which the CHX was ineffective in two periods of analysis. Significant differences between disinfectants were found with all microorganisms. The disinfectant agents analysed were effective against most of the microorganisms tested, except C. albicans. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  10. Species of Genus Ganoderma (Agaricomycetes) Fermentation Broth: A Novel Antioxidant and Antimicrobial Agent.

    Science.gov (United States)

    Cilerdzic, Jasmina; Kosanic, Marijana; Stajić, Mirjana; Vukojevic, Jelena; Ranković, Branislav

    2016-01-01

    The bioactivity of Ganoderma lucidum basidiocarps has been well documented, but there are no data on the medicinal properties of its submerged cultivation broth nor on the other species of the genus Ganoderma. Thus the aim of this study was to test the potential antimicrobial and antioxidant activity of fermentation broth obtained after submerged cultivation of G. applanatum, G. carnosum, and G. lucidum. DPPH· scavenging ability, total phenols, and flavonoid contents were measured to determine the antioxidative potential of Ganoderma spp. fermentation filtrates, whereas their antimicrobial potential was studied using the microdilution method. DPPH· scavenging activity of G. lucidum fermentation filtrates was significantly higher than that of G. applanatum and G. carnosum, with the maximum (39.67%) obtained from strain BEOFB 432. This filtrate also contained the highest concentrations of phenols (134.89 μg gallic acid equivalents/mL) and flavonoids (42.20 μg quercetin equivalent/mL). High correlations between the activity and phenol content in the extracts showed that these compounds were active components of the antioxidative activity. G. lucidum strain BEOFB 432 was the most effective antibacterial agent, whereas strain BEOFB 434 has proven to be the most effective antifungal agent. The study showed that Ganoderma spp. fermentation filtrates are novel potent antioxidative and antimicrobial agents that could be obtained more quickly and cheaper than basidiocarps.

  11. Antimicrobial screening of some medicinal plants from Mato Grosso Cerrado

    Directory of Open Access Journals (Sweden)

    Iberê E Silva Junior

    Full Text Available Hexane, dichloromethane, ethyl acetate and ethanol extracts from stem barks of Bowdichia virgilioides, Calophyllum brasiliense, Cariniana rubra, Lafoensia pacari, and Stryphnodendron obovatum and rhizome of Simaba ferruginea and Dragon's blood red sap from Croton urucurana were screened against a panel of bacteria and fungi using the micro-broth dilution method. Dragon's blood from Croton urucurana was the most effective antimicrobial plant material. Ethyl acetate and hexane extracts of Calophyllum brasiliense stem bark deserved distinction by their selective antibacterial activity. Lafoensia pacari stem bark polar extracts distinguished by their potent and selective anti-yeast activity and Bowdichia virgilioides polar and non-polar extracts by their antifungal activity towards hyalohypho-mycetes and dermatophytes. This is the first report showing antifungal activity for polar extracts of Cariniana rubra and Simaba ferruginea. This study has demonstrated antimicrobial activity of Mato Grosso Cerrado ethnomedicinal plants in in vitro assays and has indicated that they can be effective potential candidates for the development of new strategies to treat fungal and bacterial infections.

  12. Antimicrobial activity of essential oils from Mediterranean aromatic plants against several foodborne and spoilage bacteria.

    Science.gov (United States)

    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.

  13. A review on plants extract mediated synthesis of silver nanoparticles for antimicrobial applications: A green expertise

    Science.gov (United States)

    Ahmed, Shakeel; Ahmad, Mudasir; Swami, Babu Lal; Ikram, Saiqa

    2015-01-01

    Metallic nanoparticles are being utilized in every phase of science along with engineering including medical fields and are still charming the scientists to explore new dimensions for their respective worth which is generally attributed to their corresponding small sizes. The up-and-coming researches have proven their antimicrobial significance. Among several noble metal nanoparticles, silver nanoparticles have attained a special focus. Conventionally silver nanoparticles are synthesized by chemical method using chemicals as reducing agents which later on become accountable for various biological risks due to their general toxicity; engendering the serious concern to develop environment friendly processes. Thus, to solve the objective; biological approaches are coming up to fill the void; for instance green syntheses using biological molecules derived from plant sources in the form of extracts exhibiting superiority over chemical and/or biological methods. These plant based biological molecules undergo highly controlled assembly for making them suitable for the metal nanoparticle syntheses. The present review explores the huge plant diversity to be utilized towards rapid and single step protocol preparatory method with green principles over the conventional ones and describes the antimicrobial activities of silver nanoparticles. PMID:26843966

  14. A review on plants extract mediated synthesis of silver nanoparticles for antimicrobial applications: A green expertise

    Directory of Open Access Journals (Sweden)

    Shakeel Ahmed

    2016-01-01

    Full Text Available Metallic nanoparticles are being utilized in every phase of science along with engineering including medical fields and are still charming the scientists to explore new dimensions for their respective worth which is generally attributed to their corresponding small sizes. The up-and-coming researches have proven their antimicrobial significance. Among several noble metal nanoparticles, silver nanoparticles have attained a special focus. Conventionally silver nanoparticles are synthesized by chemical method using chemicals as reducing agents which later on become accountable for various biological risks due to their general toxicity; engendering the serious concern to develop environment friendly processes. Thus, to solve the objective; biological approaches are coming up to fill the void; for instance green syntheses using biological molecules derived from plant sources in the form of extracts exhibiting superiority over chemical and/or biological methods. These plant based biological molecules undergo highly controlled assembly for making them suitable for the metal nanoparticle syntheses. The present review explores the huge plant diversity to be utilized towards rapid and single step protocol preparatory method with green principles over the conventional ones and describes the antimicrobial activities of silver nanoparticles.

  15. Workshop report: the 2012 antimicrobial agents in veterinary medicine: exploring the consequences of antimicrobial drug use: a 3-D approach.

    Science.gov (United States)

    Martinez, M; Blondeau, J; Cerniglia, C E; Fink-Gremmels, J; Guenther, S; Hunter, R P; Li, X-Z; Papich, M; Silley, P; Soback, S; Toutain, P-L; Zhang, Q

    2014-02-01

    Antimicrobial resistance is a global challenge that impacts both human and veterinary health care. The resilience of microbes is reflected in their ability to adapt and survive in spite of our best efforts to constrain their infectious capabilities. As science advances, many of the mechanisms for microbial survival and resistance element transfer have been identified. During the 2012 meeting of Antimicrobial Agents in Veterinary Medicine (AAVM), experts provided insights on such issues as use vs. resistance, the available tools for supporting appropriate drug use, the importance of meeting the therapeutic needs within the domestic animal health care, and the requirements associated with food safety and food security. This report aims to provide a summary of the presentations and discussions occurring during the 2012 AAVM with the goal of stimulating future discussions and enhancing the opportunity to establish creative and sustainable solutions that will guarantee the availability of an effective therapeutic arsenal for veterinary species. © Published (2014). This article is a U.S. Government work and is in the public domain in the USA.

  16. Resistance of Staphylococcus aureus to antimicrobial agents in Ethiopia: a meta-analysis.

    Science.gov (United States)

    Deyno, Serawit; Fekadu, Sintayehu; Astatkie, Ayalew

    2017-01-01

    Emergence of antimicrobial resistance by Staphylococcus aureus has limited treatment options against its infections. The purpose of this study was to determine the pooled prevalence of resistance to different antimicrobial agents by S. aureus in Ethiopia. Web-based search was conducted in the databases of PubMed, Google Scholar, Hinari, Scopus and the Directory of Open Access Journals (DOAJ) to identify potentially eligible published studies. Required data were extracted and entered into Excel spread sheet. Statistical analyses were performed using Stata version 13.0. The metaprop Stata command was used to pool prevalence values. Twenty-one separate meta-analysis were done to estimate the pooled prevalence of the resistance of S. aureus to twenty-one different antimicrobial agents. Heterogeneity among the studies was assessed using the I 2 statistic and chi-square test. Publication bias was assessed using Egger's test. Because of significant heterogeneity amongst the studies, the random effects model was used to pool prevalence values. The electronic database search yielded 1317 studies among which 45 studies met our inclusion criteria. Our analyses demonstrated very high level of resistance to amoxicillin (77% [95% confidence interval (CI): 68%, 0.85%]), penicillin (76% [95% CI: 67%, 84%]), ampicillin (75% [95% CI: 65%, 85%]), tetracycline (62% [95% CI: 55%, 68%]), methicillin (47% [95% CI: 33%, 61%]), cotrimoxaziole (47% [95% CI: 40%, 55%]), doxycycline (43% [95% CI: 26%, 60%]), and erythromycin (41% [95% CI: 29%, 54%]). Relatively low prevalence of resistance was observed with kanamycin (14% [95% CI: 5%, 25%]) and ciprofloxacin (19% [95% CI: 13%, 26%]). The resistance level to vancomycin is 11% 995% CI: (4%, 20%). High heterogeneity was observed for each of the meta-analysis performed (I 2 ranging from 79.36% to 95.93%; all p -values ≤0.01). Eggers' test did not show a significant publication bias for all antimicrobial agents except for erythromycin and

  17. Resistance of Staphylococcus aureus to antimicrobial agents in Ethiopia: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Serawit Deyno

    2017-08-01

    Full Text Available Abstract Background Emergence of antimicrobial resistance by Staphylococcus aureus has limited treatment options against its infections. The purpose of this study was to determine the pooled prevalence of resistance to different antimicrobial agents by S. aureus in Ethiopia. Methods Web-based search was conducted in the databases of PubMed, Google Scholar, Hinari, Scopus and the Directory of Open Access Journals (DOAJ to identify potentially eligible published studies. Required data were extracted and entered into Excel spread sheet. Statistical analyses were performed using Stata version 13.0. The metaprop Stata command was used to pool prevalence values. Twenty-one separate meta-analysis were done to estimate the pooled prevalence of the resistance of S. aureus to twenty-one different antimicrobial agents. Heterogeneity among the studies was assessed using the I2 statistic and chi-square test. Publication bias was assessed using Egger’s test. Because of significant heterogeneity amongst the studies, the random effects model was used to pool prevalence values. Results The electronic database search yielded 1317 studies among which 45 studies met our inclusion criteria. Our analyses demonstrated very high level of resistance to amoxicillin (77% [95% confidence interval (CI: 68%, 0.85%], penicillin (76% [95% CI: 67%, 84%], ampicillin (75% [95% CI: 65%, 85%], tetracycline (62% [95% CI: 55%, 68%], methicillin (47% [95% CI: 33%, 61%], cotrimoxaziole (47% [95% CI: 40%, 55%], doxycycline (43% [95% CI: 26%, 60%], and erythromycin (41% [95% CI: 29%, 54%]. Relatively low prevalence of resistance was observed with kanamycin (14% [95% CI: 5%, 25%] and ciprofloxacin (19% [95% CI: 13%, 26%]. The resistance level to vancomycin is 11% 995% CI: (4%, 20%. High heterogeneity was observed for each of the meta-analysis performed (I2 ranging from 79.36% to 95.93%; all p-values ≤0.01. Eggers’ test did not show a significant publication bias for all

  18. Antimicrobial peptide production and plant-based expression systems for medical and agricultural biotechnology.

    Science.gov (United States)

    Holaskova, Edita; Galuszka, Petr; Frebort, Ivo; Oz, M Tufan

    2015-11-01

    Antimicrobial peptides (AMPs) are vital components of the innate immune system of nearly all living organisms. They generally act in the first line of defense against various pathogenic bacteria, parasites, enveloped viruses and fungi. These low molecular mass peptides are considered prospective therapeutic agents due to their broad-spectrum rapid activity, low cytotoxicity to mammalian cells and unique mode of action which hinders emergence of pathogen resistance. In addition to medical use, AMPs can also be employed for development of innovative approaches for plant protection in agriculture. Conferred disease resistance by AMPs might help us surmount losses in yield, quality and safety of agricultural products due to plant pathogens. Heterologous expression in plant-based systems, also called plant molecular farming, offers cost-effective large-scale production which is regarded as one of the most important factors for clinical or agricultural use of AMPs. This review presents various types of AMPs as well as plant-based platforms ranging from cell suspensions to whole plants employed for peptide production. Although AMP production in plants holds great promises for medicine and agriculture, specific technical limitations regarding product yield, function and stability still remain. Additionally, establishment of particular stable expression systems employing plants or plant tissues generally requires extended time scale for platform development compared to certain other heterologous systems. Therefore, fast and promising tools for evaluation of plant-based expression strategies and assessment of function and stability of the heterologously produced AMPs are critical for molecular farming and plant protection. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Design, Recombinant Fusion Expression and Biological Evaluation of Vasoactive Intestinal Peptide Analogue as Novel Antimicrobial Agent

    Directory of Open Access Journals (Sweden)

    Chunlan Xu

    2017-11-01

    Full Text Available Antimicrobial peptides represent an emerging category of therapeutic agents with remarkable structural and functional diversity. Modified vasoactive intestinal peptide (VIP (VIP analogue 8 with amino acid sequence “FTANYTRLRRQLAVRRYLAAILGRR” without haemolytic activity and cytotoxicity displayed enhanced antimicrobial activities against Staphylococcus aureus (S. aureus ATCC 25923 and Escherichia coli (E. coli ATCC 25922 than parent VIP even in the presence of 180 mM NaCl or 50 mM MgCl2, or in the range of pH 4–10. VIP analogue 8 was expressed as fusion protein thioredoxin (Trx-VIP8 in E. coli BL21(DE at a yield of 45.67 mg/L. The minimum inhibitory concentration (MIC of the recombinant VIP analogue 8 against S. aureus ATCC 25923 and E. coli ATCC 25922 were 2 μM. These findings suggest that VIP analogue 8 is a promising candidate for application as a new and safe antimicrobial agent.

  20. An Injectable System for Local and Sustained Release of Antimicrobial Agents in the Periodontal Pocket.

    Science.gov (United States)

    Morelli, Laura; Cappelluti, Martino Alfredo; Ricotti, Leonardo; Lenardi, Cristina; Gerges, Irini

    2017-08-01

    Periodontitis treatments usually require local administration of antimicrobial drugs with the aim to reduce the bacterial load inside the periodontal pocket. Effective pharmaceutical treatments may require sustained local drug release for several days in the site of interest. Currently available solutions are still not able to fulfill the clinical need for high-quality treatments, mainly in terms of release profiles and patients' comfort. This work aims to fill this gap through the development of an in situ gelling system, capable to achieve controlled and sustained release of antimicrobial agents for medium-to-long-term treatments. The system is composed of micrometer-sized β-cyclodextrin-based hydrogel (bCD-Jef-MPs), featured by a strong hydrophilic character, suspended in a synthetic block-co-polymer solution (Poloxamer 407), which is capable to undergo rapid thermally induced sol-gel phase transition at body temperature. The chemical structure of bCD-Jef-MPs was confirmed by cross-correlating data from Fourier transform infrared (FTIR) spectroscopy, swelling test, and degradation kinetics. The thermally induced sol-gel phase transition is demonstrated by rheometric tests. The effectiveness of the described system to achieve sustained release of antimicrobial agents is demonstrated in vitro, using chlorhexidine digluconate as a drug model. The results achieved in this work disclose the potential of the mentioned system in effectively treating periodontitis lesions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Development of bacterial resistance to biocides and antimicrobial agents as a consequence of biocide usage

    DEFF Research Database (Denmark)

    Seier-Petersen, Maria Amalie

    to antimicrobial agents. So far, only few studies have investigated the susceptibility of livestock-associated isolates to biocides used in their environment. Pigs are increasingly recognised as a potential reservoir of community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA), especially clones...... be of potential risk for human health, since these disinfectants are widely used at hospitals and in the food industry. Mobile genetic elements such as conjugative transposons are important vectors in the dissemination of antibiotic resistance determinants. Tn916 including the tetracycline resistance gene tet......Biocides are chemical compounds with antimicrobial properties and they are widely used for disinfection, antiseptic and preservation purposes. Biocides have been applied for centuries due to early empirical approaches, such as cleansing of wounds with wine, vinegar and honey and salting of fish...

  2. Plants of Haiti used as antifertility agents.

    Science.gov (United States)

    Weniger, B; Haag-Berrurier, M; Anton, R

    1982-07-01

    Haitian empirical medicine sprang from both European (16th to 19th century) and African (especially voodoo) traditional therapies. The use of medicinal herbs is highly developed. Our purpose was to list the plants held to be antifertility agents in the island. We identified about twenty species more or less currently used by the women as abortifacients or emmenagogues. The chemistry and active components of a few species are well-known. However, for most of them, some were partially studied, and no relation could be established between their chemical composition and their potential activities, and the rest are chemically unknown. We chemically screened extracts of Casearia ilicifolia, Eleutherine bulbosa, Rhoeo spathacea and Stemodia durantifolia, and identified flavonoids, triterpenes and sterols in the leaves of C. ilicifolia, and naphthoquinones, and a new anthraquinone, anthracene-9,10-dione-1,5-diol-4-methoxy-3-methyl-2-carboxylic acid methyl ester, in the bulbs of E, bulbosa. R. spathacea showed a stimulative activity on mouse uterus. Antifertility screening tests of C. ilicifolia and E. bulbosa showed activity in rats, but also probably toxicity.

  3. Drug Susceptibility Testing of 31 Antimicrobial Agents on Rapidly Growing Mycobacteria Isolates from China.

    Science.gov (United States)

    Pang, Hui; Li, Guilian; Zhao, Xiuqin; Liu, Haican; Wan, Kanglin; Yu, Ping

    2015-01-01

    Several species of rapidly growing mycobacteria (RGM) are now recognized as human pathogens. However, limited data on effective drug treatments against these organisms exists. Here, we describe the species distribution and drug susceptibility profiles of RGM clinical isolates collected from four southern Chinese provinces from January 2005 to December 2012. Clinical isolates (73) were subjected to in vitro testing with 31 antimicrobial agents using the cation-adjusted Mueller-Hinton broth microdilution method. The isolates included 55 M. abscessus, 11 M. fortuitum, 3 M. chelonae, 2 M. neoaurum, and 2 M. septicum isolates. M. abscessus (75.34%) and M. fortuitum (15.07%), the most common species, exhibited greater antibiotic resistance than the other three species. The isolates had low resistance to amikacin, linezolid, and tigecycline, and high resistance to first-line antituberculous agents, amoxicillin-clavulanic acid, rifapentine, dapsone, thioacetazone, and pasiniazid. M. abscessus and M. fortuitum were highly resistant to ofloxacin and rifabutin, respectively. The isolates showed moderate resistance to the other antimicrobial agents. Our results suggest that tigecycline, linezolid, clofazimine, and cefmetazole are appropriate choices for M. abscessus infections. Capreomycin, sulfamethoxazole, tigecycline, clofazimine, and cefmetazole are potentially good choices for M. fortuitum infections. Our drug susceptibility data should be useful to clinicians.

  4. Drug Susceptibility Testing of 31 Antimicrobial Agents on Rapidly Growing Mycobacteria Isolates from China

    Directory of Open Access Journals (Sweden)

    Hui Pang

    2015-01-01

    Full Text Available Objectives. Several species of rapidly growing mycobacteria (RGM are now recognized as human pathogens. However, limited data on effective drug treatments against these organisms exists. Here, we describe the species distribution and drug susceptibility profiles of RGM clinical isolates collected from four southern Chinese provinces from January 2005 to December 2012. Methods. Clinical isolates (73 were subjected to in vitro testing with 31 antimicrobial agents using the cation-adjusted Mueller-Hinton broth microdilution method. The isolates included 55 M. abscessus, 11 M. fortuitum, 3 M. chelonae, 2 M. neoaurum, and 2 M. septicum isolates. Results. M. abscessus (75.34% and M. fortuitum (15.07%, the most common species, exhibited greater antibiotic resistance than the other three species. The isolates had low resistance to amikacin, linezolid, and tigecycline, and high resistance to first-line antituberculous agents, amoxicillin-clavulanic acid, rifapentine, dapsone, thioacetazone, and pasiniazid. M. abscessus and M. fortuitum were highly resistant to ofloxacin and rifabutin, respectively. The isolates showed moderate resistance to the other antimicrobial agents. Conclusions. Our results suggest that tigecycline, linezolid, clofazimine, and cefmetazole are appropriate choices for M. abscessus infections. Capreomycin, sulfamethoxazole, tigecycline, clofazimine, and cefmetazole are potentially good choices for M. fortuitum infections. Our drug susceptibility data should be useful to clinicians.

  5. Coping with antibiotic resistance: combining nanoparticles with antibiotics and other antimicrobial agents.

    Science.gov (United States)

    Allahverdiyev, Adil M; Kon, Kateryna Volodymyrivna; Abamor, Emrah Sefik; Bagirova, Malahat; Rafailovich, Miriam

    2011-11-01

    The worldwide escalation of bacterial resistance to conventional medical antibiotics is a serious concern for modern medicine. High prevalence of multidrug-resistant bacteria among bacteria-based infections decreases effectiveness of current treatments and causes thousands of deaths. New improvements in present methods and novel strategies are urgently needed to cope with this problem. Owing to their antibacterial activities, metallic nanoparticles represent an effective solution for overcoming bacterial resistance. However, metallic nanoparticles are toxic, which causes restrictions in their use. Recent studies have shown that combining nanoparticles with antibiotics not only reduces the toxicity of both agents towards human cells by decreasing the requirement for high dosages but also enhances their bactericidal properties. Combining antibiotics with nanoparticles also restores their ability to destroy bacteria that have acquired resistance to them. Furthermore, nanoparticles tagged with antibiotics have been shown to increase the concentration of antibiotics at the site of bacterium-antibiotic interaction, and to facilitate binding of antibiotics to bacteria. Likewise, combining nanoparticles with antimicrobial peptides and essential oils generates genuine synergy against bacterial resistance. In this article, we aim to summarize recent studies on interactions between nanoparticles and antibiotics, as well as other antibacterial agents to formulate new prospects for future studies. Based on the promising data that demonstrated the synergistic effects of antimicrobial agents with nanoparticles, we believe that this combination is a potential candidate for more research into treatments for antibiotic-resistant bacteria.

  6. Antimicrobial activity of plant extracts on Candida albicans: An in vitro study

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    Sunitha Jagalur Doddanna

    2013-01-01

    Full Text Available Background and Objectives: Plants as sources of medicinal compounds have continued to play a predominant role in the maintenance of human health since ancient times. Even though several effective antifungal agents are available for oral candida infections, the failure is not uncommon because isolates of Candida albicans may exhibits resistance to the drug during therapy. The present study was conducted to evaluate the antimicrobial effects of few plant extracts on Candida albicans. An additional objective was to identify an alternative, inexpensive, simple, and effective method of preventing and controlling Candida albicans. Materials and Methods: Fine texture powder or paste form of leaves was soaked in sterile distilled water and 100% ethyl alcohol, which were kept in refrigerator at 4°C for 24 h. Then filtrates were prepared and kept in a hot air oven to get a black shining crystal powder/paste form. Stock solutions of plant extracts were inoculated on petri plates containing species of Candida albicans and incubated at 25 ± 2°C for 72 h. Results: Alcoholic curry leaves showed the maximum zone of inhibition on Candida albicans followed by aqueous tea leaves. The other plant extracts like alcoholic onion leaves, alcoholic tea leaves, alcoholic onion bulb, alcoholic aloe vera, and alcoholic mint leaves also inhibited the growth of Candida albicans but lesser extent. Conclusion: The present study renders few medicinal plants as an alternative medicines to the field of dentistry which can be used adjunct to conventional therapy of oral candidasis.

  7. Antimicrobial activity of traditional medicinal plants from Ankober District, North Shewa Zone, Amhara Region, Ethiopia

    OpenAIRE

    Molla, Ermias Lulekal; Rondevaldova, J; Bernaskova, E; Cepkova, J; Asfaw, Z; Kelbessa, E; Kokoska, L; Van Damme, Patrick

    2014-01-01

    Context: Traditional medicinal plants have long been used in Ethiopia to treat human and livestock ailments. Despite a well-documented rich tradition of medicinal plant use in the country, their direct antimicrobial effects are still poorly known. Objective: To investigate the antimicrobial activity of 19 medicinal plant species that were selected based on the ethnobotanical information on their traditional use to treat infectious diseases in Ankober District. Methods: About 23 differ...

  8. Efflux pump inhibitors (EPIs as new antimicrobial agents against Pseudomonas aeruginosa

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    Momen Askoura

    2011-05-01

    Full Text Available Pseudomonas aeruginosa is an opportunistic human pathogen and one of the leading causes of nosocomial infections worldwide. The difficulty in treatment of pseudomonas infections arises from being multidrug resistant (MDR and exhibits resistance to most antimicrobial agents due to the expression of different mechanisms overcoming their effects. Of these resistance mechanisms, the active efflux pumps in Pseudomonas aeruginosa that belong to the resistance nodulation division (RND plays a very important role in extruding the antibiotics outside the bacterial cells providing a protective means against their antibacterial activity. Beside its role against the antimicrobial agents, these pumps can extrude biocides, detergents, and other metabolic inhibitors. It is clear that efflux pumps can be targets for new antimicrobial agents. Peptidomimetic compounds such as phenylalanine arginyl β-naphthylamide (PAβN have been introduced as efflux pump inhibitors (EPIs; their mechanism of action is through competitive inhibition with antibiotics on the efflux pump resulting in increased intracellular concentration of antibiotic, hence, restoring its antibacterial activity. The advantage of EPIs is the difficulty to develop bacterial resistance against them, but the disadvantage is their toxic property hindering their clinical application. The structure activity relationship of these compounds showed other derivatives from PAβN that are higher in their activity with higher solubility in biological fluids and decreased toxicity level. This raises further questions on how can we compact Pseudomonas infections. Of particular importance, the recent resurgence in the use of older antibiotics such as polymyxins and probably applying stricter control measures in order to prevent their spread in clinical sittings.

  9. Chitosan-Based Coating with Antimicrobial Agents: Preparation, Property, Mechanism, and Application Effectiveness on Fruits and Vegetables

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    Yage Xing

    2016-01-01

    Full Text Available Chitosan coating is beneficial to maintaining the storage quality and prolonging the shelf life of postharvest fruits and vegetables, which is always used as the carrier film for the antimicrobial agents. This review focuses on the preparation, property, mechanism, and application effectiveness on the fruits and vegetables of chitosan-based coating with antimicrobial agents. Chitosan, derived by deacetylation of chitin, is a modified and natural biopolymer as the coating material. In this article, the safety and biocompatible and antimicrobial properties of chitosan were introduced because these attributes are very important for its application. The methods to prepare the chitosan-based coating with antimicrobial agents, such as essential oils, acid, and nanoparticles, were developed by other researchers. Meanwhile, the application of chitosan-based coating is mainly due to its antimicrobial activity and other functional properties, which were investigated, introduced, and analyzed in this review. Furthermore, the surface and mechanical properties were also investigated by researchers and concluded in this article. Finally, the effects of chitosan-based coating on the storage quality, microbial safety, and shelf life of fruits and vegetables were introduced. Their results indicated that chitosan-based coating with different antimicrobial agents would probably have wide prospect in the preservation of fruits and vegetables in the future.

  10. Patterns of infections, aetiological agents and antimicrobial resistance at a tertiary care hospital in northern Tanzania.

    Science.gov (United States)

    Kumburu, Happiness Houka; Sonda, Tolbert; Mmbaga, Blandina Theophil; Alifrangis, Michael; Lund, Ole; Kibiki, Gibson; Aarestrup, Frank M

    2017-04-01

    To determine the causative agents of infections and their antimicrobial susceptibility at a tertiary care hospital in Moshi, Tanzania, to guide optimal treatment. A total of 590 specimens (stool (56), sputum (122), blood (126) and wound swabs (286)) were collected from 575 patients admitted in the medical and surgical departments. The bacterial species were determined by conventional methods, and disc diffusion was used to determine the antimicrobial susceptibility pattern of the bacterial isolates. A total of 249 (42.2%) specimens were culture-positive yielding a total of 377 isolates. A wide range of bacteria was isolated, the most predominant being Gram-negative bacteria: Proteus spp. (n = 48, 12.7%), Escherichia coli (n = 44, 11.7%), Pseudomonas spp. (n = 40, 10.6%) and Klebsiella spp (n = 38, 10.1%). Wound infections were characterised by multiple isolates (n = 293, 77.7%), with the most frequent being Proteus spp. (n = 44, 15%), Pseudomonas (n = 37, 12.6%), Staphylococcus (n = 29, 9.9%) and Klebsiella spp. (n = 28, 9.6%). All Staphylococcus aureus tested were resistant to penicillin (n = 22, 100%) and susceptible to vancomycin. Significant resistance to cephalosporins such as cefazolin (n = 62, 72.9%), ceftriaxone (n = 44, 51.8%) and ceftazidime (n = 40, 37.4%) was observed in Gram-negative bacteria, as well as resistance to cefoxitin (n = 6, 27.3%) in S. aureus. The study has revealed a wide range of causative agents, with an alarming rate of resistance to the commonly used antimicrobial agents. Furthermore, the bacterial spectrum differs from those often observed in high-income countries. This highlights the imperative of regular generation of data on aetiological agents and their antimicrobial susceptibility patterns especially in infectious disease endemic settings. The key steps would be to ensure the diagnostic capacity at a sufficient number of sites and implement structures to routinely exchange, compare, analyse and report data. Sentinel sites

  11. In vitro susceptibility of Actinobacillus pleuropneumoniae strains to 42 antimicrobial agents.

    Science.gov (United States)

    Gutiérrez, C B; Píriz, S; Vadillo, S; Rodríguez Ferri, E F

    1993-04-01

    Minimal inhibitory concentration of 42 antimicrobial agents was determined against 57 field strains of Actinobacillus pleuropneumoniae isolated from pigs in Spain. Penicillins, aminoglycosides, and tetracyclines had irregular activity; ticarcillin, tobramycin, and doxycycline were the most active of each group, respectively. Macrolides, vancomycin, dapsone, and tiamulin, to which strains had high rate of resistance, were almost ineffective. Thiamphenicol, colistin, rifampin, fosfomycin, mupirocin, and metronidazole had good activity, with resistance ranging between 0 and 8.8%. Finally, cephalosporins (except cephalexin) and quinolones (especially ciprofloxacin, enrofloxacin, and sparfloxacin) were the most active antibiotics against A pleuropneumoniae.

  12. Antimicrobial activity and phyto constituents of Some medicinal plants from Kordofan province in Sudan

    International Nuclear Information System (INIS)

    Sulieman, M. H. A.; Ayoub, S. M. H.

    2008-01-01

    Twenty four extracts from different morphological parts of eleven medicinal plants belonging to ten families growing in the study area Wad Albaga, Kordofan province, have been screened photochemically and assessed for their antimicrobial activity. Selection of plants was based primarily on their ethnobotanical and ethno pharmacological uses as antimicrobial plants for treatment of infections and wounds. Flavonoids, tannins, and terpenoids were detected in all screened extracts, about 66% of the extract contained alkaloids and 66% contained saponins with different concentrations. The extracts exhibited variable antimicrobial activity against two Gram-positive and three Gram-negative standard bacteria and two fungi. (Author)

  13. Evaluation of Phenolic Content Variability along with Antioxidant, Antimicrobial, and Cytotoxic Potential of Selected Traditional Medicinal Plants from India.

    Science.gov (United States)

    Singh, Garima; Passsari, Ajit K; Leo, Vincent V; Mishra, Vineet K; Subbarayan, Sarathbabu; Singh, Bhim P; Kumar, Brijesh; Kumar, Sunil; Gupta, Vijai K; Lalhlenmawia, Hauzel; Nachimuthu, Senthil K

    2016-01-01

    Plants have been used since ancient times as an important source of biologically active substances. The aim of the present study was to investigate the phytochemical constituents (flavonoids and phenolics), antioxidant potential, cytotoxicity against HepG2 (human hepato carcinoma) cancer cell lines, and the antimicrobial activity of the methanol extract of selected traditional medicinal plants collected from Mizoram, India. A number of phenolic compounds were detected using HPLC-DAD-ESI-TOF-MS, mainly Luteolin, Kaempferol, Myricetin, Gallic Acid, Quercetin and Rutin, some of which have been described for the first time in the selected plants. The total phenolic and flavonoid contents showed high variation ranging from 4.44 to 181.91 μg of Gallic Acid equivalent per milligram DW (GAE/mg DW) and 3.17 to 102.2 μg of Quercetin/mg, respectively. The antioxidant capacity was determined by DPPH (IC50 values ranges from 34.22 to 131.4 μg/mL), ABTS (IC50 values ranges from 24.08 to 513.4 μg/mL), and reducing power assays. Antimicrobial activity was assayed against gram positive (Staphylococcus aureus), gram negative (Escherichia coli, Pseudomonas aeruginosa), and yeast (Candida albicans) demonstrating that the methanol extracts of some plants were efficacious antimicrobial agents. Additionally, cytotoxicity was assessed on human hepato carcinoma (HepG2) cancer cell lines and found that the extracts of Albizia lebbeck, Dillenia indica, and Bombax ceiba significantly decreased the cell viability at low concentrations with IC50 values of 24.03, 25.09, and 29.66 μg/mL, respectively. This is the first report of detection of phenolic compounds along with antimicrobial, antioxidant and cytotoxic potential of selected medicinal plants from India, which indicates that these plants might be valuable source for human and animal health.

  14. Evaluation of phenolic content variability, antioxidant, antimicrobial and cytotoxic potential of selected traditional medicinal plants from India

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    Garima eSingh

    2016-03-01

    Full Text Available Plants have been used since ancient times as an important source of biologically active substances. The aim of the present study was to investigate the phytochemical constituents (flavonoids and phenolics, antioxidant potential, cytotoxicity against HepG2 (human hepato carcinoma cancer cell lines and the antimicrobial activity of the methanol extract of selected traditional medicinal plants collected from Mizoram, India. A number of phenolic compounds were detected using HPLC-DAD-ESI-TOF-MS, mainly Luteolin, Kaempferol, Myricetin, Gallic Acid, Quercetin and Rutin, some of which have been described for the first time in the selected plants. The total phenolic and flavonoid contents showed high variation ranging from 4.44 to 181.91 µg of Gallic Acid equivalent per milligram DW (GAE/mg DW and 3.17 to 102.2 µg of Quercetin/mg, respectively. The antioxidant capacity was determined by DPPH (IC50 values ranges from 34.22 to 131.4 µg/mL, ABTS (IC50 values ranges from 24.08 to 513.4 µg/mL and reducing power assays. Antimicrobial activity was assayed against gram positive (Staphylococcus aureus, gram negative (Escherichia coli, Pseudomonas aeruginosa and yeast (Candida albicans demonstrating that the methanol extracts of some plants were efficacious antimicrobial agents. Additionally, cytotoxicity was assessed on human hepato carcinoma (HepG2 cancer cell lines and found that the extracts of Albizia lebbeck, Dillenia indica and Bombax ceiba significantly decreased the cell viability at low concentrations with IC50 values of 24.03, 25.09 and 29.66 µg/mL, respectively. This is the first report of detection of phenolic compounds along with antimicrobial, antioxidant and cytotoxic potential of selected medicinal plants from India, which indicates that these plants might be valuable source for human and animal health.

  15. Some medicinal plants as natural anticancer agents

    OpenAIRE

    Govind Pandey; S Madhuri

    2009-01-01

    India is the largest producer of medicinal plants and is rightly called the "Botanical garden of the World". The medicinal plants, besides having natural therapeutic values against various diseases, also provide high quality of food and raw materials for livelihood. Considerable works have been done on these plants to treat cancer, and some plant products have been marketed as anticancer drugs, based on the traditional uses and scientific reports. These plants may promote host resistance agai...

  16. Search for antibacterial and antifungal agents from selected Indian medicinal plants.

    Science.gov (United States)

    Kumar, V Prashanth; Chauhan, Neelam S; Padh, Harish; Rajani, M

    2006-09-19

    A series of 61 Indian medicinal plants belonging to 33 different families used in various infectious disorders, were screened for their antimicrobial properties. Screening was carried out at 1000 and 500 microg/ml concentrations by agar dilution method against Bacillus cereus var mycoides, Bacillus pumilus, Bacillus subtilis, Bordetella bronchiseptica, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus faecalis, Candida albicans, Aspergillus niger and Saccharomyces cerevisiae. Twenty-eight plant extracts showed activity against at least one of the test organisms used in the screening. On the basis of the results obtained, we conclude that the crude extracts of Dorema ammoniacum, Sphaeranthus indicus, Dracaena cinnabari, Mallotus philippinensis, Jatropha gossypifolia, Aristolochia indica, Lantana camara, Nardostachys jatamansi, Randia dumetorum and Cassia fistula exhibited significant antimicrobial activity and properties that support folkloric use in the treatment of some diseases as broad-spectrum antimicrobial agents. This probably explains the use of these plants by the indigenous people against a number of infections.

  17. Antimicrobial activity of traditional medicinal plants from Ankober District, North Shewa Zone, Amhara Region, Ethiopia.

    Science.gov (United States)

    Lulekal, E; Rondevaldova, J; Bernaskova, E; Cepkova, J; Asfaw, Z; Kelbessa, E; Kokoska, L; Van Damme, P

    2014-05-01

    Traditional medicinal plants have long been used in Ethiopia to treat human and livestock ailments. Despite a well-documented rich tradition of medicinal plant use in the country, their direct antimicrobial effects are still poorly known. To investigate the antimicrobial activity of 19 medicinal plant species that were selected based on the ethnobotanical information on their traditional use to treat infectious diseases in Ankober District. About 23 different ethanol extracts of plants obtained by maceration of various parts of 19 medicinal plant species were studied for potential antimicrobial activity using a broth microdilution method against Bacillus cereus, Bacteroides fragilis, Candida albicans, Clostridium perfringens, Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enteritidis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. Plant extracts from Embelia schimperi Vatke (Myrsinaceae) showed the strongest antibacterial activity with a minimum inhibitory concentration (MIC) value of 64 µg/ml against B. cereus, L. monocytogenes, and S. pyogenes. Growth inhibitory activities were also observed for extracts of Ocimum lamiifolium Hochst. (Lamiaceae) against S. pyogenes, and those of Rubus steudneri Schweinf. (Rosaceae) against S. epidermidis at an MIC value of 128 µg/ml. Generally, 74% of ethanol extracts (17 extracts) showed antimicrobial activity against one or more of the microbial strains tested at an MIC value of 512 µg/ml or below. Results confirm the antimicrobial role of traditional medicinal plants of Ankober and warrant further investigations on promising medicinal plant species so as to isolate and characterise chemicals responsible for the observed strong antimicrobial activities.

  18. In vitro susceptibility of Helicobacter pullorum strains to different antimicrobial agents.

    Science.gov (United States)

    Ceelen, Liesbeth; Decostere, Annemie; Devriese, Luc A; Ducatelle, Richard; Haesebrouck, Freddy

    2005-01-01

    The in vitro activity of 13 antimicrobial agents against 23 Helicobacter pullorum strains from poultry (21) and human (two) origin, and one human H. canadensis strain was tested by the agar dilution method. With the H. pullorum strains, monomodal distributions of Minimum Inhibitory Concentrations (MICs) were seen with lincomycin, doxycycline, gentamicin, tobramycin, erythromycin, tylosin, metronidazole, and enrofloxacin in concentration ranges considered as indicating susceptibility in other bacteria. The normal susceptibility level for nalidixic acid was situated at or slightly above the MIC breakpoints proposed for Campylobacteriaceae. Ampicillin, ceftriaxone, and sulphamethoxazole-trimethoprim showed poor activity against H. pullorum. For the H. canadensis strain, a similar susceptibility pattern was seen, except for nalidixic acid and enrofloxacin, whose MIC of >512 and 8 microg/ml, respectively, indicated resistance of this agent. With spectinomycin, a bimodal distribution of the MICs was noted for the tested strains; eight H. pullorum isolates originating from one flock showed acquired resistance (MIC>512 microg/ml).

  19. Multidrug resistant Salmonella enterica isolated from conventional pig farms using antimicrobial agents in preventative medicine programmes.

    Science.gov (United States)

    Cameron-Veas, Karla; Fraile, Lorenzo; Napp, Sebastian; Garrido, Victoria; Grilló, María Jesús; Migura-Garcia, Lourdes

    2018-04-01

    A longitudinal study was conducted to investigate the presence of multidrug antimicrobial resistance (multi-AR) in Salmonella enterica in pigs reared under conventional preventative medicine programmes in Spain and the possible association of multi-AR with ceftiofur or tulathromycin treatment during the pre-weaning period. Groups of 7-day-old piglets were treated by intramuscular injection with ceftiofur on four farms (n=40 piglets per farm) and with tulathromycin on another four farms (n=40 piglets per farm). A control group of untreated piglets (n=30 per farm) was present on each farm. Faecal swabs were collected for S. enterica culture prior to treatment, at 2, 7 and 180days post-treatment, and at slaughter. Minimal inhibitory concentrations of 14 antimicrobial agents, pulsed-field gel electrophoresis and detection of resistance genes representing five families of antimicrobial agents were performed. Plasmids carrying cephalosporin resistant (CR) genes were characterised. Sixty-six S. enterica isolates were recovered from five of eight farms. Forty-seven isolates were multi-AR and four contained bla CTX-M genes harboured in conjugative plasmids of the IncI1 family; three of these isolates were recovered before treatment with ceftiofur. The most frequent AR genes detected were tet(A) (51/66, 77%), sul1 (17/66, 26%); tet(B) (15/66, 23%) and qnrB (10/66, 15%). A direct relation between the use of ceftiofur in these conditions and the occurrence of CR S. enterica was not established. However, multi-AR was common, especially for ampicillin, streptomycin, sulphonamides and tetracycline. These antibiotics are used frequently in veterinary medicine in Spain and, therefore, should be used sparingly to minimise the spread of multi-AR. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Novel Penicillin Analogues as Potential Antimicrobial Agents; Design, Synthesis and Docking Studies.

    Science.gov (United States)

    Ashraf, Zaman; Bais, Abdul; Manir, Md Maniruzzaman; Niazi, Umar

    2015-01-01

    A number of penicillin derivatives (4a-h) were synthesized by the condensation of 6-amino penicillinic acid (6-APA) with non-steroidal anti-inflammatory drugs as antimicrobial agents. In silico docking study of these analogues was performed against Penicillin Binding Protein (PDBID 1CEF) using AutoDock Tools 1.5.6 in order to investigate the antimicrobial data on structural basis. Penicillin binding proteins function as either transpeptidases or carboxypeptidases and in few cases demonstrate transglycosylase activity in bacteria. The excellent antibacterial potential was depicted by compounds 4c and 4e against Escherichia coli, Staphylococcus epidermidus and Staphylococcus aureus compared to the standard amoxicillin. The most potent penicillin derivative 4e exhibited same activity as standard amoxicillin against S. aureus. In the enzyme inhibitory assay the compound 4e inhibited E. coli MurC with an IC50 value of 12.5 μM. The docking scores of these compounds 4c and 4e also verified their greater antibacterial potential. The results verified the importance of side chain functionalities along with the presence of central penam nucleus. The binding affinities calculated from docking results expressed in the form of binding energies ranges from -7.8 to -9.2kcal/mol. The carboxylic group of penam nucleus in all these compounds is responsible for strong binding with receptor protein with the bond length ranges from 3.4 to 4.4 Ǻ. The results of present work ratify that derivatives 4c and 4e may serve as a structural template for the design and development of potent antimicrobial agents.

  1. Novel Penicillin Analogues as Potential Antimicrobial Agents; Design, Synthesis and Docking Studies.

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    Zaman Ashraf

    Full Text Available A number of penicillin derivatives (4a-h were synthesized by the condensation of 6-amino penicillinic acid (6-APA with non-steroidal anti-inflammatory drugs as antimicrobial agents. In silico docking study of these analogues was performed against Penicillin Binding Protein (PDBID 1CEF using AutoDock Tools 1.5.6 in order to investigate the antimicrobial data on structural basis. Penicillin binding proteins function as either transpeptidases or carboxypeptidases and in few cases demonstrate transglycosylase activity in bacteria. The excellent antibacterial potential was depicted by compounds 4c and 4e against Escherichia coli, Staphylococcus epidermidus and Staphylococcus aureus compared to the standard amoxicillin. The most potent penicillin derivative 4e exhibited same activity as standard amoxicillin against S. aureus. In the enzyme inhibitory assay the compound 4e inhibited E. coli MurC with an IC50 value of 12.5 μM. The docking scores of these compounds 4c and 4e also verified their greater antibacterial potential. The results verified the importance of side chain functionalities along with the presence of central penam nucleus. The binding affinities calculated from docking results expressed in the form of binding energies ranges from -7.8 to -9.2kcal/mol. The carboxylic group of penam nucleus in all these compounds is responsible for strong binding with receptor protein with the bond length ranges from 3.4 to 4.4 Ǻ. The results of present work ratify that derivatives 4c and 4e may serve as a structural template for the design and development of potent antimicrobial agents.

  2. Epidemiology and susceptibility to antimicrobial agents of the main Nocardia species in Spain.

    Science.gov (United States)

    Valdezate, Sylvia; Garrido, Noelia; Carrasco, Gema; Medina-Pascual, María J; Villalón, Pilar; Navarro, Ana M; Saéz-Nieto, Juan A

    2017-03-01

    The aims of this study were to explore the clinical distribution, by species, of the genus Nocardia and to assess the antimicrobial susceptibilities of the 10 most prevalent species identified in Spain. Over a 10 year period (2005-14), 1119 Nocardia strains were molecularly identified and subjected to the Etest. The distribution and resistance trends over the sub-periods 2005-09 and 2010-14 were also examined. Of the strains examined, 82.9% belonged to the following species: Nocardia cyriacigeorgica (25.3%), Nocardia nova (15.0%), Nocardia abscessus (12.7%), Nocardia farcinica (11.4%), Nocardia carnea (4.3%), Nocardia brasiliensis (3.5%), Nocardia otitidiscaviarum (3.1%), Nocardia flavorosea (2.6%), Nocardia rhamnosiphila (2.6%) and Nocardia transvalensis (2.4%). Their prevalence values were similar during 2005-09 and 2010-14, except for those of N. abscessus , N. farcinica and N. transvalensis , which fell significantly in the second sub-period ( P ≤  0.05). The major location of isolation was the respiratory tract (∼86%). Half (13/27) of all strains from the CNS were N. farcinica . Significant differences in MIC results were recorded for some species between the two sub-periods. According to the CLSI's breakpoints, low resistance rates (≤15%) were recorded for seven species with respect to cefotaxime, imipenem and tobramycin; five species showed similar rates with respect to trimethoprim/sulfamethoxazole. Linezolid and amikacin were the most frequently active agents. The accurate identification of the infecting species and the determination of its susceptibility to antimicrobial agents, given the large number of strains with atypical patterns, are crucial if patients with nocardiosis are to be successfully treated. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Antimicrobial and Antifouling Polymeric Agents for Surface Functionalization of Medical Implants.

    Science.gov (United States)

    Zeng, Qiang; Zhu, Yiwen; Yu, Bingran; Sun, Yujie; Ding, Xiaokang; Xu, Chen; Wu, Yu-Wei; Tang, Zhihui; Xu, Fu-Jian

    2018-05-09

    Combating implant-associated infections is an urgent demand due to the increasing numbers in surgical operations such as joint replacements and dental implantations. Surface functionalization of implantable medical devices with polymeric antimicrobial and antifouling agents is an efficient strategy to prevent bacterial fouling and associated infections. In this work, antimicrobial and antifouling branched polymeric agents (GPEG and GEG) were synthesized via ring-opening reaction involving gentamicin and ethylene glycol species. Due to their rich primary amine groups, they can be readily coated on the polydopamine-modified implant (such as titanium) surfaces. The resultant surface coatings of Ti-GPEG and Ti-GEG produce excellent in vitro antibacterial efficacy toward both Staphylococcus aureus and Escherichia coli, while Ti-GPEG exhibit better antifouling ability. Moreover, the infection model with S. aureus shows that implanted Ti-GPEG possessed excellent antibacterial and antifouling ability in vivo. This study would provide a promising strategy for the surface functionalization of implantable medical devices to prevent implant-associated infections.

  4. Insights into the Antimicrobial Properties of Hepcidins: Advantages and Drawbacks as Potential Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Lisa Lombardi

    2015-04-01

    Full Text Available The increasing frequency of multi-drug resistant microorganisms has driven research into alternative therapeutic strategies. In this respect, natural antimicrobial peptides (AMPs hold much promise as candidates for the development of novel antibiotics. However, AMPs have some intrinsic drawbacks, such as partial degradation by host proteases or inhibition by host body fluid composition, potential toxicity, and high production costs. This review focuses on the hepcidins, which are peptides produced by the human liver with a known role in iron homeostasis, as well by numerous other organisms (including fish, reptiles, other mammals, and their potential as antibacterial and antifungal agents. Interestingly, the antimicrobial properties of human hepcidins are enhanced at acidic pH, rendering these peptides appealing for the design of new drugs targeting infections that occur in body areas with acidic physiological pH. This review not only considers current research on the direct killing activity of these peptides, but evaluates the potential application of these molecules as coating agents preventing biofilm formation and critically assesses technical obstacles preventing their therapeutic application.

  5. Efficacy of antimicrobial agents incorporated in orthodontic bonding systems: a systematic review and meta-analysis.

    Science.gov (United States)

    de Almeida, C M; da Rosa, W L O; Meereis, C T W; de Almeida, S M; Ribeiro, J S; da Silva, A F; Lund, Rafael Guerra

    2018-03-05

    The purpose of this study was to evaluate the efficacy of orthodontic bonding systems containing different antimicrobial agents, as well as the influence of antimicrobial agent incorporation in the bonding properties of these materials. Eight databases were searched: PubMed (Medline), Web of Science, Scopus, Lilacs, Ibecs, BBO, Scielo and Google Scholar. Any study that evaluated antimicrobial activity in experimental or commercial orthodontic bonding systems was included. Data were tabulated independently and in duplicated by two authors on pre-designed data collection form. The global analysis was carried out using a random-effects model, and pooled-effect estimates were obtained by comparing the standardised mean difference of each antimicrobial orthodontic adhesive with the respective control group. A p-value orthodontic bonding systems. The antimicrobial agent incorporation in orthodontic bonding systems showed higher antimicrobial activity than the control group in agar diffusion (overall standardised mean difference: 3.71; 95% CI 2.98 to 4.43) and optical density tests (0.41; 95% CI -0.05 to 0.86) (p orthodontic bonding systems were statistically similar to the control. Although there is evidence of antibacterial activity from in vitro studies, clinical and long-term studies are still necessary to confirm the effectiveness of antibacterial orthodontic bonding systems in preventing caries disease.

  6. Antimicrobial and Antioxidant Activities of Plants from Northeast of Mexico

    Science.gov (United States)

    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

  7. Antimicrobial and Antioxidant Activities of Plants from Northeast of Mexico

    Directory of Open Access Journals (Sweden)

    Ricardo Salazar-Aranda

    2011-01-01

    Full Text Available 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.

  8. Antioxidant and antimicrobial effect of some natural plant extracts added to lamb patties during storage

    Directory of Open Access Journals (Sweden)

    Ibrahim, Hayam M.

    2011-06-01

    Full Text Available Natural plants are considered an important target to investigate in order to provide a new source of natural antioxidants and/or antimicrobial agents. The optimum concentrations of some natural plant (jojoba, jatropha, ginseng and ginger extracts were determined and added to lamb patties. Some chemical and microbial characteristics of the prepared patties during storage for 9 days at 4°C were evaluated. Both the addition of these extracts and storage time had a significant effect on the patties throughout the storage period. The effectiveness of the tested natural extracts can be listed in the following order of decreasing Thiobarbituric acid reactive substance (TBARS values: ginseng > jatropha > jojoba > ginger. Aerobic plate count, mould and yeast counts decreased significantly with addition of the extracts during the storage period. Also, the addition of the extracts was significantly effective in reducing histamine, tyramine and putrescine formation during the storage period. Compared to control patties, the addition of these natural extracts was effective as antioxidant and antimicrobial agents for improving the properties of lamb patties.

    Las plantas naturales están consideradas como un importante producto donde buscar y encontrar nuevas fuentes de antioxidantes naturales y/o agentes antimicrobianos. La concentración óptima de algunos extractos de plantas naturales (jojoba, jatropha, ginseng y jengibre fueron determinado y añadidas a pasteles de cordero. Algunas características químicas y microbiológicas de los pasteles preparados y almacenados durante 9 días a 4°C fueron evaluados. Tanto la adición de estos extractos como el tiempo de almacenamiento tuvieron un efecto significativo en los pasteles en el periodo de almacenamiento. La efectividad de los extractos naturales ensayados puede ser enumerada en el siguiente orden decreciente de valores de substancias reactivas con el ácido tiobarbitúrico (TBARS: ginseng

  9. Antimicrobial efficacy of oral topical agents on microorganisms associated with radiated head and neck cancer patients: an in vitro study.

    Science.gov (United States)

    Bidra, Avinash S; Tarrand, Jeffery J; Roberts, Dianna B; Rolston, Kenneth V; Chambers, Mark S

    2011-04-01

    A variety of oral topical agents have been used for prevention and management of radiotherapy-induced adverse effects. The antimicrobial nature of some of the commonly used agents is unknown. The purpose of this study was to evaluate antimicrobial efficacies of various oral topical agents on common microorganisms associated with radiated head and neck cancer patients. Seven commonly used topical oral agents-0.12% chlorhexidine with alcohol, 0.12% chlorhexidine without alcohol, baking soda-salt rinse, 0.4% stannous fluoride gel, 0.63% stannous fluoride rinse, calcium phosphate mouthrinse, and acemannan hydrogel (aloe vera) rinse-were evaluated in vitro for their antimicrobial efficacies against four common microorganisms. A combination of baking soda-salt rinse and 0.4% stannous fluoride gel was evaluated as the eighth agent. The microorganisms used were Staphylococcus aureus, group B Streptococcus, Escherichia coli, and Candida albicans. An ELISA reader was used to measure the turbidity of microbial culture wells and optical density (OD) values for each of the 960 wells recorded. Mean OD values were rank ordered based on their turbidity. One-way ANOVA with Tukey HSD post hoc analysis was used to study differences in OD values (P baking soda- salt, calcium phosphate rinse, and the combination of baking soda-salt and stannous fluoride gel. Mean OD values classified for microorganisms from lowest to highest were Escherichia coli, Staphylococcus aureus, group B Streptococcus, and Candida albicans. A significant difference among the antimicrobial efficacies of topical agents was evident for each of four microorganisms (P < .05). There was also a significant difference among the antimicrobial efficacies of the same topical agent on the four microorganisms tested (P < .05).

  10. Resistance profiles to antimicrobial agents in bacteria isolated from acute endodontic infections: systematic review and meta-analysis.

    Science.gov (United States)

    Lang, Pauline M; Jacinto, Rogério C; Dal Pizzol, Tatiane S; Ferreira, Maria Beatriz C; Montagner, Francisco

    2016-11-01

    Infected root canal or acute apical abscess exudates can harbour several species, including Fusobacterium, Porphyromonas, Prevotella, Parvimonas, Streptococcus, Treponema, Olsenella and not-yet cultivable species. A systematic review and meta-analysis was performed to assess resistance rates to antimicrobial agents in clinical studies that isolated bacteria from acute endodontic infections. Electronic databases and the grey literature were searched up to May 2015. Clinical studies in humans evaluating the antimicrobial resistance of primary acute endodontic infection isolates were included. PRISMA guidelines were followed. A random-effect meta-analysis was employed. The outcome was described as the pooled resistance rates for each antimicrobial agent. Heterogeneity and sensitivity analyses were performed. Subgroup analyses were conducted based upon report or not of the use of antibiotics prior to sampling as an exclusion factor (subgroups A and B, respectively). Data from seven studies were extracted. Resistance rates for 15 different antimicrobial agents were evaluated (range, 3.5-40.0%). Lower resistance rates were observed for amoxicillin/clavulanic acid and amoxicillin; higher resistance rates were detected for tetracycline. Resistance rates varied according to previous use of an antimicrobial agent as demonstrated by the subgroup analyses. Heterogeneity was observed for the resistance profiles of penicillin G in subgroup A and for amoxicillin, clindamycin, metronidazole and tetracycline in subgroup B. Sensitivity analyses demonstrated that resistance rates changed for metronidazole, clindamycin, tetracycline and amoxicillin. These findings suggest that clinical isolates had low resistance to β-lactams. Further well-designed studies are needed to clarify whether the differences in susceptibility among the antimicrobial agents may influence clinical responses to treatment. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights

  11. Shelf-life extension of gilthead seabream fillets by osmotic treatment and antimicrobial agents.

    Science.gov (United States)

    Tsironi, T N; Taoukis, P S

    2012-02-01

    The objectives of the study were to evaluate the effect of selected antimicrobial agents on the shelf life of osmotically pretreated gilthead seabream and to establish reliable kinetic equations for shelf-life determination validated in dynamic conditions. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (HDM, DE 47) plus 5% NaCl and 0·5% carvacrol, 0·5% glucono-δ-lactone or 1% Citrox (commercial antimicrobial mix). Untreated and treated slices were aerobically packed and stored isothermally (0-15°C). Microbial growth and quality-related chemical indices were modelled as functions of temperature. Models were validated at dynamic storage conditions. Osmotic pretreatment with the use of antimicrobials led to significant shelf-life extension of fillets, in terms of microbial growth and organoleptic deterioration. The shelf life was 7 days for control samples at 5°C. The osmotic pretreatment with carvacrol, glucono-δ-lactone and Citrox allowed for shelf-life extension by 8, 10 and 5 days at 5°C, respectively. The results of the study show the potential of adding carvacrol, glucono-δ-lactone or Citrox in the osmotic solution to extend the shelf life and improve commercial value of chilled osmotically pretreated fish products. The developed models can be a reliable tool for predicting the shelf life of fresh or minimally processed gilthead seabream fillets in the real chill chain. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  12. Quantitative susceptibility of Streptococcus suis strains isolated from diseased pigs in seven European countries to antimicrobial agents licenced in veterinary medicine

    NARCIS (Netherlands)

    Wisselink, H.J.; Veldman, K.T.; Salmon, S.A.; Mevius, D.J.

    2006-01-01

    The susceptibility of Streptococcus suis strains (n = 384) isolated from diseased pigs in seven European countries to 10 antimicrobial agents was determined. For that purpose a microbroth dilution method was used according to CLSI recommendations. The following antimicrobial agents were tested:

  13. Antimicrobial activity of Northwestern Mexican plants against Helicobacter pylori.

    Science.gov (United States)

    Robles-Zepeda, Ramón E; Velázquez-Contreras, Carlos A; Garibay-Escobar, Adriana; Gálvez-Ruiz, Juan C; Ruiz-Bustos, Eduardo

    2011-10-01

    Helicobacter pylori is the major etiologic agent of such gastric disorders as chronic active gastritis and gastric carcinoma. Over the past few years, the appearance of antibiotic-resistant bacteria has led to the development of better treatments, such as the use of natural products. This study evaluated the anti-H. pylori activity of 17 Mexican plants used mainly in the northwestern part of Mexico (Sonora) for the empirical treatment of gastrointestinal disorders. The anti-H. pylori activity of methanolic extracts of the plants was determined by using the broth microdilution method. The 50% minimum inhibitory concentrations ranged from less than 200 to 400 μg/mL for Castella tortuosa, Amphipterygium adstringens, Ibervillea sonorae, Pscalium decompositum, Krameria erecta, Selaginella lepidophylla, Pimpinella anisum, Marrubium vulgare, Ambrosia confertiflora, and Couterea latiflora and were greater than 800 μg/mL for Byophyllum pinnatum, Tecoma stans linnaeus, Kohleria deppena, Jatropha cuneata, Chenopodium ambrosoides, and Taxodium macronatum. Only Equisetum gigantum showed no activity against H. pylori. This study suggests the important role that these plants may have in the treatment of gastrointestinal disorders caused by H. pylori. The findings set the groundwork for further characterization and elucidation of the active compounds responsible for such activity.

  14. In vivo antimicrobial activity of silver nanoparticles produced via a green chemistry synthesis using Acacia rigidula as a reducing and capping agent.

    Science.gov (United States)

    Escárcega-González, Carlos Enrique; Garza-Cervantes, J A; Vázquez-Rodríguez, A; Montelongo-Peralta, Liliana Zulem; Treviño-González, M T; Díaz Barriga Castro, E; Saucedo-Salazar, E M; Chávez Morales, R M; Regalado Soto, D I; Treviño González, F M; Carrazco Rosales, J L; Cruz, Rocío Villalobos; Morones-Ramírez, José Rubén

    2018-01-01

    One of the main issues in the medical field and clinical practice is the development of novel and effective treatments against infections caused by antibiotic-resistant bacteria. One avenue that has been approached to develop effective antimicrobials is the use of silver nanoparticles (Ag-NPs), since they have been found to exhibit an efficient and wide spectrum of antimicrobial properties. Among the main drawbacks of using Ag-NPs are their potential cytotoxicity against eukaryotic cells and the latent environmental toxicity of their synthesis methods. Therefore, diverse green synthesis methods, which involve the use of environmentally friendly plant extracts as reductive and capping agents, have become attractive to synthesize Ag-NPs that exhibit antimicrobial effects against resistant bacteria at concentrations below toxicity thresholds for eukaryotic cells. In this study, we report a green one-pot synthesis method that uses Acacia rigidula extract as a reducing and capping agent, to produce Ag-NPs with applications as therapeutic agents to treat infections in vivo. The Ag-NPs were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, energy-dispersive spectroscopy, ultraviolet-visible, and Fourier transform infrared. We show that Ag-NPs are spherical with a narrow size distribution. The Ag-NPs show antimicrobial activities in vitro against Gram-negative ( Escherichia coli , Pseudomonas aeruginosa , and a clinical multidrug-resistant strain of P. aeruginosa ) and Gram-positive ( Bacillus subtilis ) bacteria. Moreover, antimicrobial effects of the Ag-NPs, against a resistant P. aeruginosa clinical strain, were tested in a murine skin infection model. The results demonstrate that the Ag-NPs reported in this work are capable of eradicating pathogenic resistant bacteria in an infection in vivo. In addition, skin, liver, and kidney damage profiles were monitored in the murine infection model, and the

  15. Soft antimicrobial agents: synthesis and activity of labile environmentally friendly long chain quaternary ammonium compounds.

    Science.gov (United States)

    Thorsteinsson, Thorsteinn; Másson, Már; Kristinsson, Karl G; Hjálmarsdóttir, Martha A; Hilmarsson, Hilmar; Loftsson, Thorsteinn

    2003-09-11

    A series of soft quaternary ammonium antimicrobial agents, which are analogues to currently used quaternary ammonium preservatives such as cetyl pyridinium chloride and benzalkonium chloride, were synthesized. These soft analogues consist of long alkyl chain connected to a polar headgroup via chemically labile spacer group. They are characterized by facile nonenzymatic and enzymatic degradation to form their original nontoxic building blocks. However, their chemical stability has to be adequate in order for them to have antimicrobial effects. Stability studies and antibacterial and antiviral activity measurements revealed relationship between activity, lipophilicity, and stability. Their minimum inhibitory concentration (MIC) was as low as 1 microg/mL, and their viral reduction was in some cases greater than 6.7 log. The structure-activity studies demonstrate that the bioactive compounds (i.e., MIC for Gram-positive bacteria of <10 microg/mL) have an alkyl chain length between 12 and 18 carbon atoms, with a polar headgroup preferably of a small quaternary ammonium group, and their acquired inactivation half-life must be greater than 3 h at 60 degrees C.

  16. Antimicrobial peptides as potential anti-biofilm agents against multidrug-resistant bacteria.

    Science.gov (United States)

    Chung, Pooi Yin; Khanum, Ramona

    2017-08-01

    Bacterial resistance to commonly used drugs has become a global health problem, causing increased infection cases and mortality rate. One of the main virulence determinants in many bacterial infections is biofilm formation, which significantly increases bacterial resistance to antibiotics and innate host defence. In the search to address the chronic infections caused by biofilms, antimicrobial peptides (AMP) have been considered as potential alternative agents to conventional antibiotics. Although AMPs are commonly considered as the primitive mechanism of immunity and has been extensively studied in insects and non-vertebrate organisms, there is now increasing evidence that AMPs also play a crucial role in human immunity. AMPs have exhibited broad-spectrum activity against many strains of Gram-positive and Gram-negative bacteria, including drug-resistant strains, and fungi. In addition, AMPs also showed synergy with classical antibiotics, neutralize toxins and are active in animal models. In this review, the important mechanisms of action and potential of AMPs in the eradication of biofilm formation in multidrug-resistant pathogen, with the goal of designing novel antimicrobial therapeutics, are discussed. Copyright © 2017. Published by Elsevier B.V.

  17. Green One-pot Synthesis of Novel Polysubstituted Pyrazole Derivatives as Potential Antimicrobial Agents.

    Science.gov (United States)

    Beyzaei, Hamid; Motraghi, Zahra; Aryan, Reza; Zahedi, Mohammad Mehdi; Samzadeh-Kermani, Alireza

    2017-12-01

    Various biological properties of natural and synthetic pyrazole derivatives such as anti-inflammatory, antimicrobial, neuroprotective, anticonvulsant, antidepressant and anticancer activities encouraged us to propose a new, fast, green and eco-friendly procedure for the preparation of some novel 5-amino-3-(aryl substituted)-1-(2,4-dinitrophenyl)-1H-pyrazole-4-carbonitriles. They were efficiently synthesized via one-pot two-step process reaction of malononitrile, 2,4-dinitrophenylhydrazine and different benzaldehydes in deep eutectic solvent (DES) glycerol/potassium carbonate. The products yield and reaction times were considerably improved in the presence of applied DES. Antibacterial effects of all newly synthesized pyrazoles in comparison with several common antibiotics were evaluated against a variety of Gram-positive and Gram-negative pathogenic bacteria. In addition to, their inhibitory activities on three fungi were compared to some current antifungal agents. The moderate to good antimicrobial potentials particularly against fungi were observed in the major heterocyclic compounds according to the IZD, MIC, MBC and MFC results.

  18. [Identification and susceptibility to antimicrobial agents of strictly anaerobic bacteria isolated from hospitalized patients].

    Science.gov (United States)

    Kot, Katarzyna; Rokosz, Alicja; Sawicka-Grzelak, Anna; łuczak, MirosŁaw

    2002-01-01

    The aim of this study was to identify anaerobic strains isolated in 2001 from clinical specimens obtained from patients of Warsaw hospital and to evaluate a susceptibility of these strains to antimicrobial agents. In 2001 two hundred and twenty five clinical strains of obligate anaerobes were cultured, which were identified in the automatic ATB system (bioMérieux, France) using biochemical tests API 20 A. Drug-susceptibility of strains was determined also in ATB system with the use of ATB ANA strips. C. difficile strains were isolated on selective CCCA medium. Toxins A/B of C. difficile directly in stool specimens were detected by means of ELISA test (TechLab, USA). Fifty four strains of Gram-negative anaerobes (B. fragilis strains dominated) and 171 strains of Gram-positive anaerobes (the greatest number of strains belonged to genus Peptostreptococcus) were cultured from clinical specimens. In the cases of antibiotic-associated diarrhea 28 C. difficile strains were isolated and C. difficile toxins A/B were detected in 39 stool samples. The most active in vitro antimicrobials against Gram-negative anaerobes were metronidazole, imipenem, ticarcillin combined with clavulanic acid and piperacillin with tazobactam. Gram-positive, clinical strains of anaerobes were the most susceptible in vitro to beta-lactam antibiotics combined with beta-lactamase inhibitors (amoxicillin/clavulanate, piperacillin/tazobactam, ticarcillin/clavulanate) and imipenem.

  19. Novel aminopyrimidinyl benzimidazoles as potentially antimicrobial agents: Design, synthesis and biological evaluation.

    Science.gov (United States)

    Liu, Han-Bo; Gao, Wei-Wei; Tangadanchu, Vijai Kumar Reddy; Zhou, Cheng-He; Geng, Rong-Xia

    2018-01-01

    A series of novel aminopyrimidinyl benzimidazoles as potentially antimicrobial agents were designed, synthesized and characterized by IR, NMR and HRMS spectra. The biological evaluation in vitro revealed that some of the target compounds exerted good antibacterial and antifungal activity in comparison with the reference drugs. Noticeably, compound 7d could effectively inhibit the growth of A. flavus, E. coli DH52 and MRSA with MIC values of 1, 1 and 8 μg/mL, respectively. Further studies revealed that pyrimidine derivative 7d could exhibit bactericidal mode of action against both Gram positive (S. aureus and MRSA) and Gram negative (P. aeruginosa) bacteria. The active molecule 7d showed low cell toxicity and did not obviously trigger the development of resistance in bacteria even after 16 passages. Furthermore, compound 7d was able to beneficially regulate reactive oxygen species (ROS) generation for an excellent safety profile. Molecular docking study revealed that compound 7d could bind with DNA gyrase by the formation of hydrogen bonds. The preliminary exploration for antimicrobial mechanism disclosed that compound 7d could effectively intercalate into calf thymus DNA to form a steady supramolecular complex, which might further block DNA replication to exert the powerful bioactivities. The binding investigation of compound 7d with human serum albumins (HSA) revealed that this molecule could be effectively transported by HSA. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Differential antimicrobial activity of silver nanoparticles to bacteria Bacillus subtilis and Escherichia coli, and toxicity to crop plant Zea mays and beneficial B. subtilis-inoculated Z. mays

    Science.gov (United States)

    Doody, Michael A.; Wang, Dengjun; Bais, Harsh P.; Jin, Yan

    2016-10-01

    As silver nanoparticles (AgNPs) have become increasingly used in commercial antimicrobial agents and industrial and military products, concerns are increasing over their broad environmental and health impacts and risks because they are finding their way to the environment. This study was designed to quantify the antimicrobial activity of citrate-coated AgNPs (c-AgNPs; transmission electron microscope size of 44.9 ± 7.2 nm) to two species of bacteria, i.e., Gram-positive Bacillus subtilis and Gram-negative Escherichia coli, and toxicity to a major crop plant Zea mays and beneficial bacteria-inoculated plant (i.e., B. subtilis-inoculated Z. mays symbiont). Our results reveal that the exposure of c-AgNPs significantly inhibited bacteria growth and altered their growth kinetics. Z. mays experienced significant sublethal effects including reduced root length and biomass, and hyper-accumulation of Ag in roots. The beneficial interactions between B. subtilis and Z. mays were weakened as well because both species suffered sublethal effects. Potential mechanisms leading to the antimicrobial activity and toxicity of c-AgNPs to the bacteria, plant, and plant-bacteria symbiont examined in this study were discussed. Taken together, our findings advance the current knowledge of AgNPs antimicrobial property or toxicity to bacteria, crop plant, and beneficial plant-bacteria symbiotic interaction, which is a critical component for NPs environmental impact and risk assessment.

  1. New heterocycles having double characters; as antimicrobial and surface active agents.

    Directory of Open Access Journals (Sweden)

    El-Sayed, R.

    2004-12-01

    Full Text Available Fatty acids isothiocyanate (1 was used as a starting material to synthesize some important heterocycles such as triazoles, oxazoles, thiazoles, benzoxazoles and quinazolines by treating with different types of nucleophiles such as nitrogen nucleophiles, oxygen nucleophiles, and sulfur nucleophiles. The produced compounds were subjected to propylene oxide in different moles (n = 3, 5 and 7 to produce novel groups of nonionic compounds having the double function as antimicrobial and surface active agents which can be used in the manufacturing of drugs, cosmetics, pesticides or can be used as antibacterial and/or antifungal. The physical properties as surface and interfacial tension, cloud point, foaming height, wetting time, emulsification power and the critical micelle concentration (CMC were determined, antimicrobial and biodegradability were also determined.Isocianatos de acidos grasos se utilizaron como material de partida para la síntesis de importantes heterociclos tales como triazoles, oxazoles, thoazoles, benzoxazoles y quinazolinas mediante el tratamiento de los mismos con diferentes tipos de nucleofilos tales como nucleofilos nitrogenados, oxigenados, o azufrados. Los compuestos producidos se trataron con oxido de propileno a diferentes concentraciones molares (n = 3, 5 y 7 para producir nuevos grupos de compuestos no iónicos que tuvieran la doble función de ser compuestos antimicrobianos y agentes de superficie, que se pudieran usar en la fabricación de medicinas, cosméticos, pesticidas o como antibacterianos o antifúngicos. Se determinaron sus propiedades tales como tensión superficial e interfacial, punto de turbidez, altura de espuma, tiempo de mojado, poder de emulsificación y concentración micelar crítica (CMC, asi como sus propiedades antimicrobianas y de degradabilidad.

  2. Clinical Features and Antimicrobial Resistance of Bacterial Agents of Ventilator-Associated Tracheobronchitis in Hamedan, Iran

    Directory of Open Access Journals (Sweden)

    Seyyed Hamid Hashemi

    2017-09-01

    Full Text Available Objectives: Ventilator-associated tracheobronchitis (VAT is a common cause of mortality and morbidity in patients admitted to intensive care units (ICUs. This study was conducted to evaluate the clinical course, etiology, and antimicrobial resistance of bacterial agents of VAT in ICUs in Hamedan, Iran. Methods: During a 12-month period, all patients with VAT in a medical and a surgical ICU were included. The criteria for the diagnosis of VAT were fever, mucus production, a positive culture of tracheal secretions, and the absence of lung infiltration. Clinical course, including changes in temperature and tracheal secretions, and outcomes were followed. The endotracheal aspirates were cultured on blood agar and chocolate agar, and antimicrobial susceptibility testing of isolates were performed using the disk diffusion method. Results: Of the 1 070 ICU patients, 69 (6.4% were diagnosed with VAT. The mean interval between the patient’s intubation and the onset of symptoms was 4.7±8.5 days. The mean duration of response to treatment was 4.9±4.7 days. A total of 23 patients (33.3% progressed to ventilator-associated pneumonia (VAP, and 38 patients (55.0% died. The most prevalent bacterial isolates included Acinetobacter baumannii (24.6%, Pseudomonas aeruginosa (20.2%, and Enterobacter(13.0%. P. aeruginosa and Enterobacter were the most prevalent bacteria in surgical ICU, and A. baumannii and K. pneumoniae were the most common in the medical ICU. All A. baumannii and Citrobacter species were multidrug-resistant (MDR. MDR pathogens were more prevalent in medical ICU compared to surgical ICU (p < 0.001. Conclusions: VAT increases the rates of progression to VAP, the need for tracheostomy, and the incidence of mortality in ICUs. Most bacterial agents of VAT are MDR. Preventive policies for VAP, including the use of ventilator care bundle, and appropriate empirical antibiotic therapy for VAT may reduce the incidence of VAP.

  3. Antimicrobial activity and phytochemical analysis of crude extracts and essential oils from medicinal plants.

    Science.gov (United States)

    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.

  4. Use of Extract of Citrus sinensis as an antimicrobial agent for foodborne zoonotic pathogens and spoilage bacteria

    Science.gov (United States)

    Foodborne pathogens remain global health problems despite concerted efforts to control the transmission of these microorganisms through food. The resurgence of drug resistant bacteria has renewed interest in developing and testing new sources of antimicrobial agents to control foodborne illness. Thi...

  5. Systematic review of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the management of oral mucositis in cancer patients

    NARCIS (Netherlands)

    Saunders, Deborah P.; Epstein, Joel B.; Elad, Sharon; Allemano, Justin; Bossi, Paolo; van de Wetering, Marianne D.; Rao, Nikhil G.; Potting, Carin; Cheng, Karis K.; Freidank, Annette; Brennan, Michael T.; Bowen, Joanne; Dennis, Kristopher; Lalla, Rajesh V.

    2013-01-01

    The aim of this project was to develop clinical practice guidelines on the use of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the prevention and management of oral mucositis (OM) in cancer patients. A systematic review of the available literature was conducted. The body

  6. Systematic review of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the management of oral mucositis in cancer patients.

    NARCIS (Netherlands)

    Saunders, D.P.; Epstein, J.B.; Elad, S.; Allemano, J.; Bossi, P.; Wetering, M.D. van de; Rao, N.G.; Potting, C.M.J.; Cheng, K.K.; Freidank, A.; Brennan, M.T.; Bowen, J.; Dennis, K.; Lalla, R.V.

    2013-01-01

    PURPOSE: The aim of this project was to develop clinical practice guidelines on the use of antimicrobials, mucosal coating agents, anesthetics, and analgesics for the prevention and management of oral mucositis (OM) in cancer patients. METHODS: A systematic review of the available literature was

  7. Edible coating as carrier of antimicrobial agents to extend the shelf life of fresh-cut apples

    Science.gov (United States)

    Edible coatings with antimicrobial agents can extend shelf-life of fresh-cut fruits. The effect of lemongrass, oregano oil and vanillin incorporated in apple puree-alginate edible coatings, on shelf-life of fresh-cut 'Fuji' apples, was investigated. Coated apples were packed in air filled polypropyl...

  8. Antimicrobial Activity of 22 Plants Used in Urolithiasis Medicine in Western Algeria

    Directory of Open Access Journals (Sweden)

    F. Bouabdelli

    2012-05-01

    Full Text Available Objective: Our investigation is about the determination of the antibacterial efficiency of 22 medicinal plants on the four most frequent bacteria in urinary infections. These infections are responsible for more than 15% of urinary stones formation. Methods: We have initiated an extraction liquid/solid. In this respect, we have used water extractions according to the standard methods utilized by the local population, i.e: (i the d écoction, (ii the infusion, (iii the mac ération and (iiii the percolation. The microorganisms used are Staphylooccus aureus, Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa. The strains were isolated from patients having urinary infections. The antibiotic disks Kanamicin, Colistin, Amoxicillin, Gentamicin, Ampicillin were applied to the reference bacteria at concentrations of 30 毺 g, 50毺 g, 25毺 g, 10毺 g et 10毺 g respectively. Results: These studies showed that decoction (d had the higher effect with 43.3 % followed by percolation (p (28.3% and maceration (m (16.7%. Infusion (i had a limited effect (11.7%. Escherichia coli (E.coli, Proteus mirabilis, Staphylococcus aureus showed an average sensitivity of 28% in each case. However, Pseudomonas aeruginosa, a highly pathogenic and resistant bacteria showed up to 17.5% of sensitivity. 16.3% of the plant extracts showed a high antimicrobial activity. Pseudomonas aeruginosa was highly resistant to Kanamycin, Amoxicillin and Ampicillin and at a lower extent to Colistin and Gentamicin. However, it was sensitive to some plant extracts such as Allium sativum, Artemesia compestris(p,m, Citrus aurantium(p, Cotula cinerea(p, Lavandula officinalis (d , Globularia alypum (d , Juniperus phoeniceae (m , Olea europaea (p, Pistacia lentiscus (m , Trachyspermum ammi (m, Zygophyllum album (p and Zingiber officinalis (d. Conclusion: The present work shows that most of the studied plants are potentially a good source of antimicrobial agents and it proves the

  9. Antimicrobial, Anthelmintic, and Antiviral Activity of Plants Traditionally Used for Treating Infectious Disease in the Similipal Biosphere Reserve, Odisha, India.

    Science.gov (United States)

    Panda, Sujogya K; Padhi, Laxmipriya; Leyssen, Pieter; Liu, Maoxuan; Neyts, Johan; Luyten, Walter

    2017-01-01

    In the present study, we tested in vitro different parts of 35 plants used by tribals of the Similipal Biosphere Reserve (SBR, Mayurbhanj district, India) for the management of infections. From each plant, three extracts were prepared with different solvents (water, ethanol, and acetone) and tested for antimicrobial ( E. coli, S. aureus, C. albicans ); anthelmintic ( C. elegans ); and antiviral ( enterovirus 71 ) bioactivity. In total, 35 plant species belonging to 21 families were recorded from tribes of the SBR and periphery. Of the 35 plants, eight plants (23%) showed broad-spectrum in vitro antimicrobial activity (inhibiting all three test strains), while 12 (34%) exhibited narrow spectrum activity against individual pathogens (seven as anti-staphylococcal and five as anti-candidal). Plants such as Alangium salviifolium, Antidesma bunius, Bauhinia racemosa, Careya arborea, Caseria graveolens, Cleistanthus patulus, Colebrookea oppositifolia, Crotalaria pallida, Croton roxburghii, Holarrhena pubescens, Hypericum gaitii, Macaranga peltata, Protium serratum, Rubus ellipticus , and Suregada multiflora showed strong antibacterial effects, whilst Alstonia scholaris, Butea monosperma, C. arborea, C. pallida, Diospyros malbarica, Gmelina arborea, H. pubescens, M. peltata, P. serratum, Pterospermum acerifolium, R. ellipticus , and S. multiflora demonstrated strong antifungal activity. Plants such as A. salviifolium, A. bunius, Aporosa octandra, Barringtonia acutangula, C. graveolens, C. pallida, C. patulus, G. arborea, H. pubescens, H. gaitii, Lannea coromandelica, M. peltata, Melastoma malabathricum, Millettia extensa, Nyctanthes arbor-tristis, P. serratum, P. acerifolium, R. ellipticus, S. multiflora, Symplocos cochinchinensis, Ventilago maderaspatana , and Wrightia arborea inhibit survival of C. elegans and could be a potential source for anthelmintic activity. Additionally, plants such as A. bunius, C. graveolens, C. patulus, C. oppositifolia, H. gaitii, M. extensa

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

    OpenAIRE

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

    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 chromatograp...

  11. Phenolic profile and antimicrobial activities to selected microorganisms of some wild medical plant from Slovakia

    Directory of Open Access Journals (Sweden)

    Lukáš Hleba

    2014-08-01

    Full Text Available Objective: To investigate the chemical composition and antimicrobial activity of the methanol extracts of Tussilago farfara (T. farfara, Equisetum arvense, Sambucus nigra (S. nigra and Aesculus hippocastanum. Methods: The antimicrobial activities of the extracts against Enterococcus raffinosus, Escherichia coli, Lactobacillus rhamnosus, Pseudomonas aeruginosa, Serratia rubidaea, Saccharomyces cerevisiae and Staphylococcus epidermis were determined by the microbroth dilution method according to Clinical and Laboratory Standards Institute, while the concentrations of main phenolic acids and flavonoids in the form of trimethylsilyl ethers were analysed using gas chromatography-mass spectrometry. The probit analysis was used for statistical evaluation. Results: Of the 4 plant tested, all extracts showed a significant antimicrobial activity against one or more species of examined microorganisms. The most active antimicrobial plant extract was gathered from T. farfara, followed by Aesculus hippocastanum and Equisetum arvense. The extract from S. nigra showed no antimicrobial effects. The flavonoids quercetin and kaempferol, as well as several phenolic acids (p-hydroxybenzoic acid, gallic acid, ferulic acid and caffeic acid were identified in all extracts. The highest concentrations of bioactive compounds were detected in the extracts of T. farfara (9 587.6 µg/mg quercetin and 4 875.3 µg/mg caffeic acid as well as S. nigra (4788.8 µg/mg kaempferol. Conclusions: We can state that the methanolic plant extract of T. farfara showed the strongest antimicrobial activity against Saccharomyces cerevisiae as well as other tested microorganisms. At the same time, a good antimicrobial activity was found in the other medical plant extracts as well. No antimicrobial effect of the S. nigra extract was found with respect to the growth of Pseudomonas aeruginosa, Enterococcus raffinosus and Saccharomyces cerevisiae.

  12. Root Canal Irrigation: Chemical Agents and Plant Extracts Against Enterococcus faecalis

    Science.gov (United States)

    Borzini, Letizia; Condò, Roberta; De Dominicis, Paolo; Casaglia, Adriano; Cerroni, Loredana

    2016-01-01

    Background: There are various microorganisms related to intra and extra-radicular infections and many of these are involved in persistent infections. Bacterial elimination from the root canal is achieved by means of the mechanical action of instruments and irrigation as well as the antibacterial effects of the irrigating solutions. Enterococcus faecalis can frequently be isolated from root canals in cases of failed root canal treatments. Antimicrobial agents have often been developed and optimized for their activity against endodontic bacteria. An ideal root canal irrigant should be biocompatible, because of its close contact with the periodontal tissues during endodontic treatment. Sodium hypoclorite (NaOCl) is one of the most widely recommended and used endodontic irrigants but it is highly toxic to periapical tissues. Objectives: To analyze the literature on the chemotherapeutic agent and plant extracts studied as root canal irrigants. In particularly, the study is focused on their effect on Enterococcus faecalis. Method: Literature search was performed electronically in PubMed (PubMed Central, MEDLINE) for articles published in English from 1982 to April 2015. The searched keywords were “endodontic irrigants” and “Enterococcus faecalis” and “essential oil” and “plant extracts”. Results: Many of the studied chemotherapeutic agents and plant extracts have shown promising results in vitro. Conclusion: Some of the considered phytotherapic substances, could be a potential alternative to NaOCl for the biomechanical treatment of the endodontic space. PMID:28217184

  13. Cytotoxicity of topical antimicrobial agents used in burn wounds in Australasia.

    Science.gov (United States)

    Fraser, John F; Cuttle, Leila; Kempf, Margit; Kimble, Roy M

    2004-03-01

    Burn sepsis is a leading cause of mortality and morbidity in patients with major burns. The use of topical antimicrobial agents has helped improve the survival of these patients. Silvazine (Sigma Pharmaceuticals, Melbourne, Australia) (1% silver sulphadiazine and 0.2% chlorhexidine digluconate) is used exclusively in Australasia, and there is no published study on its cytotoxicity. This study compared the relative cytotoxicity of Silvazine with 1% silver sulphadiazine (Flamazine (Smith & Nephew Healthcare, Hull, UK)) and a silver-based dressing (Acticoat (Smith & Nephew Healthcare, Hull, UK)). Dressings were applied to the centre of culture plates that were then seeded with keratinocytes at an estimated 25% confluence. The plates were incubated for 72 h and culture medium and dressings then removed. Toluidine blue was added to stain the remaining keratinocytes. Following removal of the dye, the plates were photographed under standard conditions and these digital images were analysed using image analysis software. Data was analysed using Student's t-test. In the present study, Silvazine is the most cytotoxic agent. Seventy-two hour exposure to Silvazine in the present study results in almost no keratinocyte survival at all and a highly statistically significant reduction in cell survival relative to control, Acticoat and Flamazine (Pstudy comparing Acticoat, Silvazine and Flamazine, Silvazine shows an increased cytotoxic effect, relative to control, Flamazine and Acticoat. An in-vivo study is required to determine whether this effect is carried into the clinical setting.

  14. Echinacea plants as antioxidant and antibacterial agents: From traditional medicine to biotechnological applications.

    Science.gov (United States)

    Sharifi-Rad, Mehdi; Mnayer, Dima; Morais-Braga, Maria Flaviana Bezerra; Carneiro, Joara Nályda Pereira; Bezerra, Camila Fonseca; Coutinho, Henrique Douglas Melo; Salehi, Bahare; Martorell, Miquel; Del Mar Contreras, María; Soltani-Nejad, Azam; Uribe, Yoshie Adriana Hata; Yousaf, Zubaida; Iriti, Marcello; Sharifi-Rad, Javad

    2018-05-10

    The genus Echinacea consists of 11 taxa of herbaceous and perennial flowering plants. In particular, Echinacea purpurea (L.) Moench is widely cultivated all over the United States, Canada, and in Europe, exclusively in Germany, for its beauty and reported medicinal properties. Echinacea extracts have been used traditionally as wound healing to improve the immune system and to treat respiratory symptoms caused by bacterial infections. Echinacea extracts have demonstrated antioxidant and antimicrobial activities, and to be safe. This survey aims at reviewing the medicinal properties of Echinacea species, their cultivation, chemical composition, and the potential uses of these plants as antioxidant and antibacterial agents in foods and in a clinical context. Moreover, the factors affecting the chemical composition of Echinacea spp. are also covered. Copyright © 2018 John Wiley & Sons, Ltd.

  15. Gold nanoparticles synthesized by Brassica oleracea (Broccoli) acting as antimicrobial agents against human pathogenic bacteria and fungi

    Science.gov (United States)

    Piruthiviraj, Prakash; Margret, Anita; Krishnamurthy, Poornima Priyadharsani

    2016-04-01

    Production of antimicrobial agents through the synthesis of gold nanoparticles using green technology has been extensively made consistent by various researchers; yet, this study uses the flower bud's aqueous extracts of Brassica oleracea (Broccoli) as a reducing agent for chloroauric acid (1 mM). After 30 min of incubation, synthesis of gold nanoparticles (AuNps) was observed by a change in extract color from pale yellow to purple color. Synthesis of AuNps was confirmed in UV-visible spectroscopy at the range of approximately 560 nm. The SEM analysis showed the average nanoparticles size of 12-22 nm. The antimicrobial activity of AuNps was analyzed by subjecting it to human pathogenic bacteria (Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumonia) and fungi (Aspergillus flavus, Aspergillus niger and Candida albicans) using disc diffusion method. The broccoli-synthesized AuNps showed the efficient antibacterial and antifungal activity of above-mentioned microbes. It was confirmed that AuNps have the best antimicrobial agent compared to the standard antibiotics (Gentamicin and Fluconazole). When the concentrations of AuNps were increased (10, 25, and 50 µg/ml), the sensitivity zone also increased for all the tested microbes. The synthesized AuNps are capable of rendering high antimicrobial efficacy and, hence, have a great potential in the preparation of drugs used against major bacterial and fungal diseases in humans.

  16. Synthesis of bio-based nanocomposites for controlled release of antimicrobial agents in food packaging

    Science.gov (United States)

    DeGruson, Min Liu

    The utilization of bio-based polymers as packaging materials has attracted great attention in both scientific and industrial areas due to the non-renewable and nondegradable nature of synthetic plastic packaging. Polyhydroxyalkanoate (PHA) is a biobased polymer with excellent film-forming and coating properties, but exhibits brittleness, insufficient gas barrier properties, and poor thermal stability. The overall goal of the project was to develop the polyhydroxyalkanoate-based bio-nanocomposite films modified by antimicrobial agents with improved mechanical and gas barrier properties, along with a controlled release rate of antimicrobial agents for the inhibition of foodborne pathogens and fungi in food. The ability for antimicrobial agents to intercalate into layered double hydroxides depended on the nature of the antimicrobial agents, such as size, spatial structure, and polarity, etc. Benzoate and gallate anions were successfully intercalated into LDH in the present study and different amounts of benzoate anion were loaded into LDH under different reaction conditions. Incorporation of nanoparticles showed no significant effect on mechanical properties of polyhydroxybutyrate (PHB) films, however, significantly increased the tensile strength and elongation at break of polyhydroxybutyrate-co-valerate (PHBV) films. The effects of type and concentration of LDH nanoparticles (unmodified LDH and LDH modified by sodium benzoate and sodium gallate) on structure and properties of PHBV films were then studied. The arrangement of LDH in the bio-nanocomposite matrices ranged from exfoliated to phase-separated depending on the type and concentration of LDH nanoparticles. Intercalated or partially exfoliated structures were obtained using modified LDH, however, only phase-separated structures were formed using unmodified LDH. The mechanical (tensile strength and elongation at break) and thermo-mechanical (storage modulus) properties were significantly improved with low

  17. Susceptibility of bacteria isolated from acute gastrointestinal infections to rifaximin and other antimicrobial agents in Mexico.

    Science.gov (United States)

    Novoa-Farías, O; Frati-Munari, A C; Peredo, M A; Flores-Juárez, S; Novoa-García, O; Galicia-Tapia, J; Romero-Carpio, C E

    2016-01-01

    Bacterial resistance may hamper the antimicrobial management of acute gastroenteritis. Bacterial susceptibility to rifaximin, an antibiotic that achieves high fecal concentrations (up to 8,000μg/g), has not been evaluated in Mexico. To determine the susceptibility to rifaximin and other antimicrobial agents of enteropathogenic bacteria isolated from patients with acute gastroenteritis in Mexico. Bacterial strains were analyzed in stool samples from 1,000 patients with diagnosis of acute gastroenteritis. The susceptibility to rifaximin (RIF) was tested by microdilution (<100, <200, <400 and <800μg/ml) and susceptibility to chloramphenicol (CHL), trimethoprim-sulfamethoxazole (T-S), neomycin (NEO), furazolidone (FUR), fosfomycin (FOS), ampicillin (AMP) and ciprofloxacin (CIP) was tested by agar diffusion at the concentrations recommended by the Clinical & Laboratory Standards Institute and the American Society for Microbiology. Isolated bacteria were: enteropathogenic Escherichia coli (E. coli) (EPEC) 531, Shigella 120, non-Typhi Salmonella 117, Aeromonas spp. 80, enterotoxigenic E. coli (ETEC) 54, Yersinia enterocolitica 20, Campylobacter jejuni 20, Vibrio spp. 20, Plesiomonas shigelloides 20, and enterohemorrhagic E. coli (EHEC 0:157) 18. The overall cumulative susceptibility to RIF at <100, <200, <400, and <800μg/ml was 70.6, 90.8, 99.3, and 100%, respectively. The overall susceptibility to each antibiotic was: AMP 32.2%, T-S 53.6%, NEO 54.1%, FUR 64.7%, CIP 67.3%, CLO 73%, and FOS 81.3%. The susceptibility to RIF <400 and RIF <800μg/ml was significantly greater than with the other antibiotics (p<0.001). Resistance of enteropathogenic bacteria to various antibiotics used in gastrointestinal infections is high. Rifaximin was active against 99-100% of these enteropathogens at reachable concentrations in the intestine with the recommended dose. Copyright © 2015 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.

  18. Chimeric Peptides as Implant Functionalization Agents for Titanium Alloy Implants with Antimicrobial Properties

    Science.gov (United States)

    Yucesoy, Deniz T.; Hnilova, Marketa; Boone, Kyle; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

    2015-04-01

    Implant-associated infections can have severe effects on the longevity of implant devices and they also represent a major cause of implant failures. Treating these infections associated with implants by antibiotics is not always an effective strategy due to poor penetration rates of antibiotics into biofilms. Additionally, emerging antibiotic resistance poses serious concerns. There is an urge to develop effective antibacterial surfaces that prevent bacterial adhesion and proliferation. A novel class of bacterial therapeutic agents, known as antimicrobial peptides (AMPs), are receiving increasing attention as an unconventional option to treat septic infection, partly due to their capacity to stimulate innate immune responses and for the difficulty of microorganisms to develop resistance towards them. While host and bacterial cells compete in determining the ultimate fate of the implant, functionalization of implant surfaces with AMPs can shift the balance and prevent implant infections. In the present study, we developed a novel chimeric peptide to functionalize the implant material surface. The chimeric peptide simultaneously presents two functionalities, with one domain binding to a titanium alloy implant surface through a titanium-binding domain while the other domain displays an antimicrobial property. This approach gains strength through control over the bio-material interfaces, a property built upon molecular recognition and self-assembly through a titanium alloy binding domain in the chimeric peptide. The efficiency of chimeric peptide both in-solution and absorbed onto titanium alloy surface was evaluated in vitro against three common human host infectious bacteria, Streptococcus mutans, Staphylococcus epidermidis, and Escherichia coli. In biological interactions such as occur on implants, it is the surface and the interface that dictate the ultimate outcome. Controlling the implant surface by creating an interface composed chimeric peptides may therefore

  19. Anti-microbial and anti-biofilm compounds from Indonesian medicinal plants

    NARCIS (Netherlands)

    Pratiwi, Sylvia U.T.

    2015-01-01

    Microbial biofilms causing elevated resistance to both most anti-microbial drugs and the host defense systems, which often results in persistent and difficult-to-treat infections. The discovery of anti-infective agents which are active against planktonic and biofilm microorganisms are therefore

  20. Therapeutic Potential of Plants as Anti-Microbials for Drug Discovery

    Directory of Open Access Journals (Sweden)

    Ramar Perumal Samy

    2010-01-01

    Full Text Available The uses of traditional medicinal plants for primary health care have steadily increased worldwide in recent years. Scientists are in search of new phytochemicals that could be developed as useful anti-microbials for treatment of infectious diseases. Currently, out of 80% of pharmaceuticals derived from plants, very few are now being used as anti-microbials. Plants are rich in a wide variety of secondary metabolites that have found anti-microbial properties. This review highlights the current status of traditional medicine, its contribution to modern medicine, recent trends in the evaluation of anti-microbials with a special emphasis upon some tribal medicine, in vitro and in vivo experimental design for screening, and therapeutic efficacy in safety and human clinical trails for commercial outlet. Many of these commercially available compounds are crude preparations administered without performing human clinical trials. Recent methods are useful to standardize the extraction for scientific investigation of new phytochemicals and anti-microbials of traditionally used plants. It is concluded that once the local ethnomedical preparations of traditional sources are scientifically evaluated before dispensing they should replace existing drugs commonly used for the therapeutic treatment of infection. This method should be put into practice for future investigations in the field of ethnopharmacology, phytochemistry, ethnobotany and other biological fields for drug discovery.

  1. Antimicrobial activities of medicinal plants used in folklore remedies ...

    African Journals Online (AJOL)

    In south-western part of Nigeria Psidium guajava and Mangifera indica are commonly used for herbal preparations in the treatment of toothache, gastrointestinal disorders, dynsentery, diarrhoea, sore gums and sore throats. This has, therefore, led to the investigation of the antimicrobial activities of methanolic extracts of P.

  2. In Vitro Antimicrobial Activity Of Crude Extracts From Plants ...

    African Journals Online (AJOL)

    Extracts from the leaves of Bryophyllum pinnatum and Kalanchoe crenata were screened for their antimicrobial activities. Solvents used included water, methanol, and local solvents such as palmwine, local gin (Seaman's Schnapps 40% alcoholic drink,) and “omi ekan-ogi” (Sour water from 3 days fermented milled maize).

  3. Differential antimicrobial activity of silver nanoparticles to bacteria Bacillus subtilis and Escherichia coli, and toxicity to crop plant Zea mays and beneficial B. subtilis-inoculated Z. mays

    Energy Technology Data Exchange (ETDEWEB)

    Doody, Michael A.; Wang, Dengjun; Bais, Harsh P.; Jin, Yan, E-mail: yjin@udel.edu [University of Delaware, Department of Plant and Soil Sciences (United States)

    2016-10-15

    As silver nanoparticles (AgNPs) have become increasingly used in commercial antimicrobial agents and industrial and military products, concerns are increasing over their broad environmental and health impacts and risks because they are finding their way to the environment. This study was designed to quantify the antimicrobial activity of citrate-coated AgNPs (c-AgNPs; transmission electron microscope size of 44.9 ± 7.2 nm) to two species of bacteria, i.e., Gram-positive Bacillus subtilis and Gram-negative Escherichia coli, and toxicity to a major crop plant Zea mays and beneficial bacteria-inoculated plant (i.e., B. subtilis-inoculated Z. mays symbiont). Our results reveal that the exposure of c-AgNPs significantly inhibited bacteria growth and altered their growth kinetics. Z. mays experienced significant sublethal effects including reduced root length and biomass, and hyper-accumulation of Ag in roots. The beneficial interactions between B. subtilis and Z. mays were weakened as well because both species suffered sublethal effects. Potential mechanisms leading to the antimicrobial activity and toxicity of c-AgNPs to the bacteria, plant, and plant–bacteria symbiont examined in this study were discussed. Taken together, our findings advance the current knowledge of AgNPs antimicrobial property or toxicity to bacteria, crop plant, and beneficial plant–bacteria symbiotic interaction, which is a critical component for NPs environmental impact and risk assessment.Graphical Abstract.

  4. Differential antimicrobial activity of silver nanoparticles to bacteria Bacillus subtilis and Escherichia coli, and toxicity to crop plant Zea mays and beneficial B. subtilis-inoculated Z. mays

    International Nuclear Information System (INIS)

    Doody, Michael A.; Wang, Dengjun; Bais, Harsh P.; Jin, Yan

    2016-01-01

    As silver nanoparticles (AgNPs) have become increasingly used in commercial antimicrobial agents and industrial and military products, concerns are increasing over their broad environmental and health impacts and risks because they are finding their way to the environment. This study was designed to quantify the antimicrobial activity of citrate-coated AgNPs (c-AgNPs; transmission electron microscope size of 44.9 ± 7.2 nm) to two species of bacteria, i.e., Gram-positive Bacillus subtilis and Gram-negative Escherichia coli, and toxicity to a major crop plant Zea mays and beneficial bacteria-inoculated plant (i.e., B. subtilis-inoculated Z. mays symbiont). Our results reveal that the exposure of c-AgNPs significantly inhibited bacteria growth and altered their growth kinetics. Z. mays experienced significant sublethal effects including reduced root length and biomass, and hyper-accumulation of Ag in roots. The beneficial interactions between B. subtilis and Z. mays were weakened as well because both species suffered sublethal effects. Potential mechanisms leading to the antimicrobial activity and toxicity of c-AgNPs to the bacteria, plant, and plant–bacteria symbiont examined in this study were discussed. Taken together, our findings advance the current knowledge of AgNPs antimicrobial property or toxicity to bacteria, crop plant, and beneficial plant–bacteria symbiotic interaction, which is a critical component for NPs environmental impact and risk assessment.Graphical Abstract

  5. Indications and patterns of therapeutic use of antimicrobial agents in the Danish pig production from 2002 to 2008

    DEFF Research Database (Denmark)

    Jensen, Vibeke Frøkjær; Emborg, Hanne-Dorthe; Aarestrup, Frank Møller

    2011-01-01

    This study describes trends in the use and indications for prescriptions of antimicrobial agents in the Danish pig production in the period between 2002 and 2008 and is the first description of a complete prescription pattern for one animal species in an entire country. Data on all prescription...... for pigs in Denmark were retrieved from the VetStat database. Antimicrobial use was measured in defined animal daily doses (ADD) for the specific age-group and in ADDkg as a measure of amounts used. According to the results of the ADDkg data, 26% of all antimicrobials were prescribed for sows, 38....../piglets, by 141% for weaning pigs, and by 81% for finisher pig. The most commonly used class of antibiotics was tetracycline for all age-groups, replacing the previously used macrolide/lincosamide group. The use of pleuromutilin increased in 2008 to the level of macrolides. In sow/piglets, the second most used...

  6. Design, synthesis and biological evaluation of 5-fluorouracil-derived benzimidazoles as novel type of potential antimicrobial agents.

    Science.gov (United States)

    Fang, Xue-Jie; Jeyakkumar, Ponmani; Avula, Srinivasa Rao; Zhou, Qian; Zhou, Cheng-He

    2016-06-01

    A series of 5-fluorouracil benzimidazoles as novel type of potential antimicrobial agents were designed and synthesized for the first time. Bioactive assay manifested that some of the prepared compounds exhibited good or even stronger antibacterial and antifungal activities against the tested strains in comparison with reference drugs norfloxacin, chloromycin and fluconazole. Noticeably, 3-fluorobenzyl benzimidazole derivative 5c gave remarkable antimicrobial activities against Saccharomyces cerevisiae, MRSA and Bacillus proteus with MIC values of 1, 2 and 4μg/mL, respectively. Experimental research revealed that compound 5c could effectively intercalate into calf thymus DNA to form compound 5c-DNA complex which might block DNA replication and thus exert antimicrobial activities. Molecular docking indicated that compound 5c should bind with DNA topoisomerase IA through three hydrogen bonds by the use of fluorine atom and oxygen atoms in 5-fluorouracil with the residue Lys 423. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Turning Waste into Value: Nanosized Natural Plant Materials of Solanum incanum L. and Pterocarpus erinaceus Poir with Promising Antimicrobial Activities

    Directory of Open Access Journals (Sweden)

    Sharoon Griffin

    2016-04-01

    Full Text Available Numerous plants are known to exhibit considerable biological activities in the fields of medicine and agriculture, yet access to their active ingredients is often complicated, cumbersome and expensive. As a consequence, many plants harbouring potential drugs or green phyto-protectants go largely unnoticed, especially in poorer countries which, at the same time, are in desperate need of antimicrobial agents. As in the case of plants such as the Jericho tomato, Solanum incanum, and the common African tree Pterocarpus erinaceus, nanosizing of original plant materials may provide an interesting alternative to extensive extraction and isolation procedures. Indeed, it is straightforward to obtain considerable amounts of such common, often weed-like plants, and to mill the dried material to more or less uniform particles of microscopic and nanoscopic size. These particles exhibit activity against Steinernema feltiae or Escherichia coli, which is comparable to the ones seen for processed extracts of the same, respective plants. As S. feltiae is used as a model nematode indicative of possible phyto-protective uses in the agricultural arena, these findings also showcase the potential of nanosizing of crude “waste” plant materials for specific practical applications, especially—but not exclusively—in developing countries lacking a more sophisticated industrial infrastructure.

  8. Immune mediators of sea-cucumber Holothuria tubulosa (Echinodermata) as source of novel antimicrobial and anti-staphylococcal biofilm agents.

    Science.gov (United States)

    Schillaci, Domenico; Cusimano, Maria Grazia; Cunsolo, Vincenzo; Saletti, Rosaria; Russo, Debora; Vazzana, Mirella; Vitale, Maria; Arizza, Vincenzo

    2013-06-24

    The present study aims to investigate coelomocytes, immune mediators cells in the echinoderm Holothuria tubulosa, as an unusual source of antimicrobial and antibiofilm agents. The activity of the 5kDa peptide fraction of the cytosol from H. tubulosa coelomocytes (5-HCC) was tested against a reference group of Gram-negative and Gram-positive human pathogens. Minimal inhibitory concentrations (MICs) ranging from 125 to 500 mg/ml were determined against tested strains. The observed biological activity of 5-HCC could be due to two novel peptides, identified by capillary RP-HPLC/nESI-MS/MS, which present the common chemical-physical characteristics of antimicrobial peptides. Such peptides were chemically synthesized and their antimicrobial activity was tested. The synthetic peptides showed broad-spectrum activity at 12.5 mg/ml against the majority of the tested Gram-positive and Gram-negative strains, and they were also able to inhibit biofilm formation in a significant percentage at a concentration of 3.1 mg/ml against staphylococcal and Pseudomonas aeruginosa strains.The immune mediators in H. tubulosa are a source of novel antimicrobial peptides for the development of new agents against biofilm bacterial communities that are often intrinsically resistant to conventional antibiotics.

  9. Antimicrobial Activity of Various Plant Extracts on Pseudomonas Species Associated with Spoilage of Chilled Fish

    Directory of Open Access Journals (Sweden)

    Osan Bahurmiz

    2016-11-01

    Full Text Available The antimicrobial activity of various plant extracts on Pseudomonas bacteria isolated from spoiled chilled tilapia (Oreochromis sp. was evaluated in this study. In the first stage of this study, red tilapia was subjected to chilled storage (4°C for 3 weeks, and spoilage bacteria were isolated and identified from the spoiled fish. Pseudomonas was the dominant bacteria isolated from the spoiled fish and further identification revealed that P. putida, P. fluorescens and Pseudomonas spp. were the main species of this group. In the second stage, methanolic extracts of 15 selected plant species were screened for their antimicrobial activity, by agar disc diffusion method, against the Pseudomonas isolates. Results indicated that most of the extracts had different degrees of activity against the bacterial isolates. The strongest activity was exhibited by bottlebrush flower (Callistemon viminalis extract. This was followed by extracts from guava bark (Psidium guajava and henna leaf (Lawsonia inermis. Moderate antimicrobial activities were observed in extracts of clove (Syzygium aromaticum, leaf and peel of tamarind (Tamarindus indica, cinnamon bark (Cinnamomum zeylanicum, wild betel leaf (Piper sarmentosum and fresh thyme (Thymus spp.. Weak or no antimicrobial activity was observed from the remaining extracts. The potential antimicrobial activity shown by some plant extracts in this study could significantly contribute to the fish preservation.

  10. Combating Pathogenic Microorganisms Using Plant-Derived Antimicrobials: A Minireview of the Mechanistic Basis

    Directory of Open Access Journals (Sweden)

    Abhinav Upadhyay

    2014-01-01

    Full Text Available The emergence of antibiotic resistance in pathogenic bacteria has led to renewed interest in exploring the potential of plant-derived antimicrobials (PDAs as an alternative therapeutic strategy to combat microbial infections. Historically, plant extracts have been used as a safe, effective, and natural remedy for ailments and diseases in traditional medicine. Extensive research in the last two decades has identified a plethora of PDAs with a wide spectrum of activity against a variety of fungal and bacterial pathogens causing infections in humans and animals. Active components of many plant extracts have been characterized and are commercially available; however, research delineating the mechanistic basis of their antimicrobial action is scanty. This review highlights the potential of various plant-derived compounds to control pathogenic bacteria, especially the diverse effects exerted by plant compounds on various virulence factors that are critical for pathogenicity inside the host. In addition, the potential effect of PDAs on gut microbiota is discussed.

  11. Vinegar as an antimicrobial agent for control of Candida spp. in complete denture wearers

    Directory of Open Access Journals (Sweden)

    Telma Maria Silva Pinto

    2008-12-01

    Full Text Available The use of denture is known to increase the carriage of Candida in healthy patients, and the proliferation of Candida albicans strains can be associated with denture-induced stomatitis. The aim of this study was to evaluate the use of vinegar as an antimicrobial agent for control of Candida spp. in complete upper denture wearers. Fifty-five patients were submitted to a detailed clinical interview and oral clinical examination, and were instructed to keep their dentures immersed in a 10% vinegar solution (pH less than 3 overnight for 45 days. Before and after the experimental period, saliva samples were collected for detection of Candida, counting of cfu/mL and identification of species by phenotypical tests (germ tube formation, chlamidoconidia production, and carbohydrate fermentation and assimilation. The results were analyzed using Spearman's correlation and Student's t-test (p£0.05. Candida yeasts were present in 87.3% of saliva samples before the treatment. A significant reduction was verified in CFU/mL counts of Candida after treatment. A positive correlation between Candida and denture stomatitis was verified, since the decrease of cfu/mL counts was correlated with a reduction in cases of denture stomatitis. Although it was not able to eliminate C. albicans, the immersion of the complete denture in 10% vinegar solution, during the night, reduced the amounts (cfu/mL of Candida spp. in the saliva and the presence of denture stomatitis in the studied patients.

  12. Interactions between the antimicrobial agent triclosan and the bloom-forming cyanobacteria Microcystis aeruginosa

    International Nuclear Information System (INIS)

    Huang, Xiaolong; Tu, Yenan; Song, Chaofeng; Li, Tiancui; Lin, Juan; Wu, Yonghong; Liu, Jiantong; Wu, Chenxi

    2016-01-01

    Highlights: • Triclosan inhibit the growth and photosynthesis of M. aeruginosa at environmental relevant level. • TEM imaging showed destruction of M. aeruginosa cell ultrastructure during triclosan exposure. • Triclosan can be biotransformed by M. aeruginosa with methylation as a major pathway. • Presence of M. aeruginosa enhanced the photodegradation of triclosan. - Abstract: Cyanobacteria can co-exist in eutrophic waters with chemicals or other substances derived from personal care products discharged in wastewater. In this work, we investigate the interactions between the antimicrobial agent triclosan (TCS) and the bloom-forming cyanobacteria Microcystis aeruginosa. M. aeruginosa was very sensitive to TCS with the 96 h lowest observed effect concentration of 1.0 and 10 μg/L for inhibition of growth and photosynthetic activity, respectively. Exposure to TCS at environmentally relevant levels (0.1–2.0 μg/L) also affected the activities of superoxide dismutase (SOD) and the generation of reduced glutathione (GSH), while microcystin production was not affected. Transmission electron microscope (TEM) examination showed the destruction of M. aeruginosa cell ultrastructure during TCS exposure. TCS however, can be biotransformed by M. aeruginosa with methylation as a major biotransformation pathway. Furthermore, the presence of M. aeruginosa in solution promoted the photodegradation of TCS. Overall, our results demonstrate that M. aeruginosa plays an important role in the dissipation of TCS in aquatic environments but high residual TCS can exert toxic effects on M. aeruginosa.

  13. Synthesis and In Vitro Evaluation of New Thiosemicarbazone Derivatives as Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Zafer Asım Kaplancıklı

    2016-01-01

    Full Text Available In an effort to develop potent antimicrobial agents, new thiosemicarbazone derivatives were synthesized via the reaction of 4-[4-(trifluoromethylphenyl]thiosemicarbazide with aromatic aldehydes. The compounds were evaluated for their inhibitory effects on pathogenic bacteria and yeasts using the CLSI broth microdilution method. Microplate Alamar Blue Assay was also carried out to determine the antimycobacterial activities of the compounds against Mycobacterium tuberculosis H37Rv. Among these derivatives, compounds 5 and 11 were more effective against Enterococcus faecalis (ATCC 29212 than chloramphenicol, whereas compounds 1, 2, and 12 and chloramphenicol showed the same level of antibacterial activity against E. faecalis. Moreover, compound 2 and chloramphenicol exhibited the same level of antibacterial activity against Staphylococcus aureus. On the other hand, the most potent anticandidal derivatives were found as compounds 2 and 5. These derivatives and ketoconazole exhibited the same level of antifungal activity against Candida glabrata. According to the Microplate Alamar Blue Assay, the tested compounds showed weak to moderate antitubercular activity.

  14. Comparative in vitro activity of 16 antimicrobial agents against Actinobacillus pleuropneumoniae.

    Science.gov (United States)

    Yoshimura, H; Takagi, M; Ishimura, M; Endoh, Y S

    2002-01-01

    Sixteen antimicrobial agents were tested for their activity against 68 isolates of Actinobacillus pleuropneumoniae by determining the minimum inhibitory concentrations (MICs). Ceftiofur and the fluoroquinolones danofloxacin and enrofloxacin were the most active compounds, with a MIC for 90% of the isolates (MIC90) of (0.05 microg/ml. The MIC90 values of benzylpenicillin, amoxicillin and aspoxicillin were 0.78 units/ml, 0.39 microg/ml and colistin and tiamulin. Of these, spectinomycin was the least active, with a MIC50 of 25 microg/ml, followed by tiamulin, with a MIC50 of 6.25 microg/ml. Of the 68 isolates tested, 49 (72.0%) were of serotype 2; 14 (20.5%) were of serotype 1; 2 each (3.0%) were of serotypes 5 and 6; and one was of serotype 7. Of the isolates, 23 (33.8%) were resistant to one or more of the major antibiotics. Antibiotic resistance was found only infrequently among serotype 2, with 5 (10.2%) of 49 isolates being resistant to chloramphenicol and/or oxytetracycline, while it occurred in 18 (94.7%) of the 19 isolates of other serotypes.

  15. Comparison of methods for in vitro testing of susceptibility of porcine Mycoplasma species to antimicrobial agents.

    Science.gov (United States)

    Ter Laak, E A; Pijpers, A; Noordergraaf, J H; Schoevers, E C; Verheijden, J H

    1991-02-01

    The MICs of 18 antimicrobial agents used against strains of three porcine Mycoplasma species were determined by a serial broth dilution method. Twenty field strains of M. hyorhinis, ten field strains of M. hyopneumoniae, six field strains of M. flocculare, and the type strains of these species were tested. Twelve field strains and the type strain of M. hyorhinis were also tested by an agar dilution method. Tests were read at various time points. When the broth dilution method was used, the final MIC had to be read 2 days after color changes had stopped. MICs of tetracycline, oxytetracycline, doxycycline, and minocycline were low for the three Mycoplasma species tested. MICs of chlortetracycline were 8 to 16 times higher than MICs of the other tetracyclines. Spiramycin, tylosin, kitasamycin, spectinomycin, tiamulin, lincomycin, and clindamycin were effective against all strains of M. hyorhinis and M. hyopneumoniae. The quinolones were highly effective against M. hyopneumoniae but less effective against M. hyorhinis. The susceptibility patterns for M. hyopneumoniae and M. flocculare were similar.

  16. Potential of Submergedly Cultivated Mycelia of Ganoderma spp. as Antioxidant and Antimicrobial Agents.

    Science.gov (United States)

    Ćilerdžić, Jasmina; Stajic, Mirjana; Vukojevic, Jelena

    2016-01-01

    The study aimed to evaluate the antiradical and antimicrobial (antibacterial and antifungal) potentials of ethanol mycelial extracts of selected Ganoderma species and strains and to define interand intraspecies diversity among Ganoderma species and strains. Ganoderma lucidum strains were good DPPH• scavengers (neutralizing up to 57.12% radicals), contrary to G. applanatum (20.35%) and G. carnosum (17.04%). High correlations between the activities and contents of total phenols in the extracts showed that these compounds were carriers of the activity. Results obtained by both discdiffusion and microdilution methods indicated that the extract of G. lucidum BEOFB 433 was the most potent antibacterial agent that inhibited growth of almost all bacterial species at a concentration of 1.0 mg/mL. Salmonella typhimurium was the most sensitive species to the mycelium extracts. Extracts of G. lucidum BEOFB 431 and BEOFB 434 showed the best antifungal activity since in concentration of 0.5 mg/mL inhibited the growth of Aspergillus glaucus (BEOFB 431) and the growth of A. glaucus and Trichoderma viride (BEOFB 434). Extracts of G. applanatum and G. lucidum BEOFB 431 had the strongest fungicidal effects, with lethal outcomes for A. glaucus and T. viride, respectively, being noted at a concentration of 1.17 mg/mL. Aspergillus niger was proved as the most resistant species.

  17. Interactions between the antimicrobial agent triclosan and the bloom-forming cyanobacteria Microcystis aeruginosa

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaolong [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Wuhan Zhongke Hydrobiological Environment Engineering Co., Ltd, Wuhan 430071 (China); Tu, Yenan; Song, Chaofeng; Li, Tiancui; Lin, Juan [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu, Yonghong [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Sciences, Chinese Academy of Sciences, Nanjing 210008 (China); Liu, Jiantong [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Wu, Chenxi, E-mail: chenxi.wu@ihb.ac.cn [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2016-03-15

    Highlights: • Triclosan inhibit the growth and photosynthesis of M. aeruginosa at environmental relevant level. • TEM imaging showed destruction of M. aeruginosa cell ultrastructure during triclosan exposure. • Triclosan can be biotransformed by M. aeruginosa with methylation as a major pathway. • Presence of M. aeruginosa enhanced the photodegradation of triclosan. - Abstract: Cyanobacteria can co-exist in eutrophic waters with chemicals or other substances derived from personal care products discharged in wastewater. In this work, we investigate the interactions between the antimicrobial agent triclosan (TCS) and the bloom-forming cyanobacteria Microcystis aeruginosa. M. aeruginosa was very sensitive to TCS with the 96 h lowest observed effect concentration of 1.0 and 10 μg/L for inhibition of growth and photosynthetic activity, respectively. Exposure to TCS at environmentally relevant levels (0.1–2.0 μg/L) also affected the activities of superoxide dismutase (SOD) and the generation of reduced glutathione (GSH), while microcystin production was not affected. Transmission electron microscope (TEM) examination showed the destruction of M. aeruginosa cell ultrastructure during TCS exposure. TCS however, can be biotransformed by M. aeruginosa with methylation as a major biotransformation pathway. Furthermore, the presence of M. aeruginosa in solution promoted the photodegradation of TCS. Overall, our results demonstrate that M. aeruginosa plays an important role in the dissipation of TCS in aquatic environments but high residual TCS can exert toxic effects on M. aeruginosa.

  18. Antimicrobial thin films based on ayurvedic plants extracts embedded in a bioactive glass matrix

    Science.gov (United States)

    Floroian, L.; Ristoscu, C.; Candiani, G.; Pastori, N.; Moscatelli, M.; Mihailescu, N.; Negut, I.; Badea, M.; Gilca, M.; Chiesa, R.; Mihailescu, I. N.

    2017-09-01

    Ayurvedic medicine is one of the oldest medical systems. It is an example of a coherent traditional system which has a time-tested and precise algorithm for medicinal plant selection, based on several ethnopharmacophore descriptors which knowledge endows the user to adequately choose the optimal plant for the treatment of certain pathology. This work aims for linking traditional knowledge with biomedical science by using traditional ayurvedic plants extracts with antimicrobial effect in form of thin films for implant protection. We report on the transfer of novel composites from bioactive glass mixed with antimicrobial plants extracts and polymer by matrix-assisted pulsed laser evaporation into uniform thin layers onto stainless steel implant-like surfaces. The comprehensive characterization of the deposited films was performed by complementary analyses: Fourier transformed infrared spectroscopy, glow discharge optical emission spectroscopy, scanning electron microscopy, atomic force microscopy, electrochemical impedance spectroscopy, UV-VIS absorption spectroscopy and antimicrobial tests. The results emphasize upon the multifunctionality of these coatings which allow to halt the leakage of metal and metal oxides into the biological fluids and eventually to inner organs (by polymer use), to speed up the osseointegration (due to the bioactive glass use), to exert antimicrobial effects (by ayurvedic plants extracts use) and to decrease the implant price (by cheaper stainless steel use).

  19. Resistance to antimicrobial agents among Salmonella isolates recovered from layer farms and eggs in the Caribbean region.

    Science.gov (United States)

    Adesiyun, Abiodun; Webb, Lloyd; Musai, Lisa; Louison, Bowen; Joseph, George; Stewart-Johnson, Alva; Samlal, Sannandan; Rodrigo, Shelly

    2014-12-01

    This investigation determined the frequency of resistance of 84 isolates of Salmonella comprising 14 serotypes recovered from layer farms in three Caribbean countries (Trinidad and Tobago, Grenada, and St. Lucia) to eight antimicrobial agents, using the disc diffusion method. Resistance among isolates of Salmonella was related to the country of recovery, type of sample, size of layer farms, and isolate serotype. Overall, all (100.0%) of the isolates exhibited resistance to one or more of seven antimicrobial agents tested, and all were susceptible to chloramphenicol. The resistance detected ranged from 11.9% to sulphamethoxazole-trimethoprim (SXT) to 100.0% to erythromycin. The difference was, however, not statistically significant (P = 0.23). Across countries, for types of samples that yielded Salmonella, significant differences in frequency of resistance were detected only to SXT (P = 0.002) in Trinidad and Tobago and to gentamycin (P = 0.027) in St. Lucia. For the three countries, the frequency of resistance to antimicrobial agents was significantly different for ampicillin (P = 0.001) and SXT (P = 0.032). A total of 83 (98.8%) of the 84 isolates exhibited 39 multidrug resistance patterns. Farm size significantly (P = 0.032) affected the frequency of resistance to kanamycin across the countries. Overall, among the 14 serotypes of Salmonella tested, significant (P resistance were detected to kanamycin, ampicillin, and SXT. Results suggest that the relatively high frequency of resistance to six of the antimicrobial agents (erythromycin, streptomycin, gentamycin, kanamycin, ampicillin, and tetracycline) tested and the multidrug resistance detected may pose prophylactic and therapeutic concerns for chicken layer farms in the three countries studied.

  20. Potential inhibitors of dapE and argE enzymes as the new antimicrobial agents: Synthesis and characterization

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Jan; Pícha, Jan; Vaněk, Václav; Jiráček, Jiří; Slaninová, Jiřina; Fučík, Vladimír; Holz, R. C.

    2008-01-01

    Roč. 14, č. 8 (2008), s. 83-84 ISSN 1075-2617. [European Peptide Symposium /30./. 31.08.2008-05.09.2008, Helsinki] R&D Projects: GA AV ČR IAA400550614 Institutional research plan: CEZ:AV0Z40550506 Keywords : antimicrobial agents * dapE and argE inhibitors * synthesis and activity Subject RIV: CC - Organic Chemistry

  1. In vitro and in vivo analysis of antimicrobial agents alone and in combination against multi-drug resistant Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Songzhe eHE

    2015-05-01

    Full Text Available Objective To investigate the in vitro and in vivo antibacterial activities of tigecycline and other 13 common antimicrobial agents, alone or in combination, against multi-drug resistant Acinetobacter baumannii.MethodsAn in vitro susceptibility test of 101 Acinetobacter baumannii was used to detect minimal inhibitory concentrations (MICs. A mouse lung infection model of multi-drug resistant Acinetobacter baumannii,established by the ultrasonic atomization method, was used to define in vivo antimicrobial activities.Results Multi-drug resistant Acinetobacter baumannii showed high sensitivity to tigecycline (98% inhibition, polymyxin B (78.2% inhibition, and minocycline (74.2% inhibition. However, the use of these antimicrobial agents in combination with other antimicrobial agents produced synergistic or additive effects. In vivo data showed that white blood cell (WBC counts in drug combination groups C (minocycline + amikacin and D (minocycline + rifampicin were significantly higher than in groups A (tigecycline and B (polymyxin B (P < 0.05, after administration of the drugs 24h post-infection. Lung tissue inflammation gradually increased in the model group during the first 24h after ultrasonic atomization infection; vasodilation, congestion with hemorrhage were observed 48h post infection. After three days of anti-infective therapy in groups A, B, C and D, lung tissue inflammation in each group gradually recovered with clear structures. The mortality rates in drug combination groups (groups C and D were much lower than in groups A and B.ConclusionThe combination of minocycline with either rifampicin or amikacin is more effective against multidrug-resistant Acinetobacter baumannii than single-agent tigecycline or polymyxin B. In addition, the mouse lung infection by ultrasonic atomization is a suitable model for drug screening and analysis of infection mechanism.

  2. Initial antimicrobial activity studies of plants of the riverside forests of the southern Uruguay River

    Directory of Open Access Journals (Sweden)

    Ana Bertucci

    Full Text Available Development of new antimicrobial compounds against different microorganisms is becoming critically important, as infectious diseases are still one of the leading causes of death in the world. Plants can be a useful source of these lead compounds. In this study, 66 extracts of 25 plants of the riverside forest of southern Uruguay River were studied for antimicrobial activity against Staphylococcus aureus, Listeria inocua, Escherichia coli, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Aspergillus niger and Candida albicans. Fifty-three of these extracts showed some kind of antimicrobial activity. Six of these (Eugenia mansoni, Eugenia repanda, Myrcianthes cisplatensis, Paullinia ellegans, Petunia sp and Ruprechtia laxiflora presented activity against Mycobacterium tuberculosis with MIC values as low as 50 μg/mL.

  3. Peptide LyeTx I mnΔk: A potential antimicrobial agent

    International Nuclear Information System (INIS)

    Fuscaldi, Leonardo Lima; Avelar Júnior, Joaquim T. de; Boff, Daiane; Santos, Daniel M. dos; Oliveira, Vívian L.S. de; Mata, Lays M. da; Contarini, Sara M. Lopes; Miranda, Sued E. Mendes; Amaral, Flavio Almeida; Diniz, Simone O.F.; Lima, Maria Elena de; Cardoso, Valbert N.

    2017-01-01

    Full text: Introduction: The emergence of resistance to current antibiotics and the incidence of opportunistic bacterial infections have stimulated the search for new antibiotic agents. In this sense, antimicrobial peptides are promising molecules due to their different mechanisms of action compared to classic antibiotics. Peptides LyeTx I (Lycosa erythrognatha venom) and LyeTx I mnΔK (truncated and modified derivative) present in vitro antimicrobial activity. Aim: To evaluate in vivo antimicrobial activity of LyeTx I mnΔK in an experimental model of septic arthritis. Methods: CEUA/UFMG: protocol nº 236/2014. At day 0, male C57/BL6 mice (∼7 weeks; (∼25 g) were inoculated with 10 μL of a S. aureus (ATCC® 6538) suspension (8 x 107 CFU/mL) or of sterile PBS (negative control group) by intraarticular injection (i.a.) in the right posterior articulation. At days 2, 4 and 6, mice were treated, by i.a., with clindamycin, LyeTx I or LyeTx I mnΔK (7.35, 0.08, 0.08 nmol/i.a., respectively). The positive control group received saline as treatment. At day 2 (before the first dose) and at day 7, an aliquot containing 7.4 MBq of technetium- 99m -Ceftizoxime ( 99m Tc-CFT) was injected into the tail vein of mice. At 2 h postradiopharmaceutical injection, animals were anesthetized and placed under a gamma camera (NuclideTM TH 22). Images were acquired during 5 min and quantitative analyzed to determine 99m Tc-CFT uptake by infectious focus, by means of target to non-target ratio (t/n-t) determination. Beyond scintigraphic images, animals were conducted to some other investigations post-treatment (at day 7). First, bacterial recovery assay was performed in order to assess pathogen reduction in the infected joint. Then, inflammatory process reduction was evaluated by the determination of immune cells recruitment. Finally, the removal threshold hypernociception was measured aiming to estimate pain. Quantitative data were expressed as 'mean±error' (n=4-6) and

  4. Peptide LyeTx I mnΔk: A potential antimicrobial agent

    Energy Technology Data Exchange (ETDEWEB)

    Fuscaldi, Leonardo Lima; Avelar Júnior, Joaquim T. de; Boff, Daiane; Santos, Daniel M. dos; Oliveira, Vívian L.S. de; Mata, Lays M. da; Contarini, Sara M. Lopes; Miranda, Sued E. Mendes; Amaral, Flavio Almeida; Diniz, Simone O.F.; Lima, Maria Elena de; Cardoso, Valbert N. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Full text: Introduction: The emergence of resistance to current antibiotics and the incidence of opportunistic bacterial infections have stimulated the search for new antibiotic agents. In this sense, antimicrobial peptides are promising molecules due to their different mechanisms of action compared to classic antibiotics. Peptides LyeTx I (Lycosa erythrognatha venom) and LyeTx I mnΔK (truncated and modified derivative) present in vitro antimicrobial activity. Aim: To evaluate in vivo antimicrobial activity of LyeTx I mnΔK in an experimental model of septic arthritis. Methods: CEUA/UFMG: protocol nº 236/2014. At day 0, male C57/BL6 mice (∼7 weeks; (∼25 g) were inoculated with 10 μL of a S. aureus (ATCC® 6538) suspension (8 x 107 CFU/mL) or of sterile PBS (negative control group) by intraarticular injection (i.a.) in the right posterior articulation. At days 2, 4 and 6, mice were treated, by i.a., with clindamycin, LyeTx I or LyeTx I mnΔK (7.35, 0.08, 0.08 nmol/i.a., respectively). The positive control group received saline as treatment. At day 2 (before the first dose) and at day 7, an aliquot containing 7.4 MBq of technetium-{sup 99m}-Ceftizoxime ({sup 99m}Tc-CFT) was injected into the tail vein of mice. At 2 h postradiopharmaceutical injection, animals were anesthetized and placed under a gamma camera (NuclideTM TH 22). Images were acquired during 5 min and quantitative analyzed to determine {sup 99m}Tc-CFT uptake by infectious focus, by means of target to non-target ratio (t/n-t) determination. Beyond scintigraphic images, animals were conducted to some other investigations post-treatment (at day 7). First, bacterial recovery assay was performed in order to assess pathogen reduction in the infected joint. Then, inflammatory process reduction was evaluated by the determination of immune cells recruitment. Finally, the removal threshold hypernociception was measured aiming to estimate pain. Quantitative data were expressed as 'mean±error' (n=4

  5. ANTIMICROBIAL ACTIVITY OF OIL-BEARING PLANTS LAMIACEAE LINDL. TOWARDS ESCHERICHIA COLI

    Directory of Open Access Journals (Sweden)

    L.A. Kotyuk

    2016-03-01

    Full Text Available The paper relates to study of biological activity of 40% ethanol extracts of Dracocephalum moldavica, Hyssopus officinalis, Satureja hortensis, Lophanthus anisatus and Monarda diduma, grown in Ukrainian Polissya, against a pathogenic agent Escherichia coli UCM – B (ATCC 25922. The research proves that ethanol extracts of H. officinalis, D. moldavica, S. hortensis, L. anisatus exert antimicrobial activity as the extracted substances provided a twofold increase in minimum bactericidal concentration (MBC values against E. coli. Likewise, a twofold increase was observed in minimum inhibitory concentration (MIC of L. anisatus ethanol extracts. As to M. diduma ethanol extracts, their inhibitory and bactericidal influence on E. coli was not registered. Oil-bearing plants (family Lamiaceae, grown in Zhytomyr Polissya, are characterized by antimicrobial properties, attributed to biologically active substances that are formed and accumulated in the plant material. The main components of hyssop essential oil are isopinocamphone (44.43%, pinocamphone (35.49%, myrtenol (5.26 %, germacrene D (3.15 %, pulegone (2.93 %, bicyclogermacrene (1.35 %. In mint anise essential oil prevailed pulegone (59.19%, izomenton (14.34%, bicyclogermacrene (3,21 %, β-kariofilen (2,99 %, menton (2.21 %, 1,6-germacradien-5-ol (1.5 %, isopulegone (1.4 %, in summer savory – carvacrol (89.07%, g-terpinene (3.53%, α-thujone (1.7 %, camphor (1.48 %. The dominant components of moldavian dragonhead essential oil were geranial (26.19% and neral (22.36%, 2-(1-hydroxy-1-isopropyl-cyklopentanon (8.29 % , 2,3-dehydro-1,8-cineole (6.87 %, 3-(1-hydroxy-1-isopropyl cyklopentanon (6,51 %, nerol (4.74 %, 3-methyl-2-cyclohexane 1-on (2.13 %. The paper draws attention to further more detailed study of ethanol extracts of hyssop, moldavian dragonhead, summer savory, mint anise with the aim of producing antibacterial herbal

  6. Microbiological aspects of an in situ model to study effects of antimicrobial agents on dental plaque ecology.

    Science.gov (United States)

    Giertsen, E; Guggenheim, B; Thurnheer, T; Gmür, R

    2000-10-01

    This study validates an in situ model for ecological studies of dental plaque exposed to various antimicrobial agents with different modes of action on plaque bacteria. Eleven subjects wore two acrylic appliances, each containing two bovine enamel discs, during two 1-wk test periods. Using a split-mouth crossover design, the appliances were dipped twice daily for 1 min into water (control; treatment A), fluoride (26.3 mM NaF; B), zinc acetate (20.0 mM; C), or fluoride plus zinc acetate (D). Four of the subjects used also chlorhexidine diacetate (2.2 mM; E) and chlorhexidine plus fluoride (F). At the end of each period, plaque was collected from the discs, after which the microbiota were analyzed by culture, automated quantitative immunofluorescence, and a viability fluorescence stain. As compared to control, treatments B, C, and D resulted in a significant reduction of individual taxa as detected by immunofluorescence, whereas similar bacterial viability and total bacterial numbers were observed. In contrast, chlorhexidine significantly reduced bacterial viability, total cell numbers, and the abundance of most of the enumerated taxa. We conclude that this in situ model is well suited to study effects of antimicrobial agents on dental plaque ecology. Combined with viability testing, immunofluorescence is obviously superior to culture in detecting taxa-specific shifts caused by antimicrobial agents.

  7. Screening of Methanol and Acetone Extracts of Fourteen Indian Medicinal Plants for Antimicrobial Activity

    OpenAIRE

    VAGHASIYA, Yogeshkumar; CHANDA, Sumitra V.

    2014-01-01

    The methanol and acetone extracts of 14 plants belonging to different families were evaluated for antimicrobial activity against five Gram-positive bacteria: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Bacillus subtilis, Micrococcus flavus; seven Gram-negative bacteria: Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Salmonella typhimurium, Citrobacter freundii; and three fungi: Candida tropicalis, Cryptococcus lut...

  8. Multitasking antimicrobial peptides, plant development, and host defense against biotic/abiotic stress

    Science.gov (United States)

    Crop losses due to pathogens are a major threat to global food security. Plants employ a multilayer defense system against pathogens including use of physical barriers (cell wall), induction of hypersensitive defense response (HR), resistance (R) proteins, and synthesis of antimicrobial peptides (AM...

  9. In vitro susceptibility of contagious ovine digital dermatitis associated Treponema spp. isolates to antimicrobial agents in the UK.

    Science.gov (United States)

    Angell, Joseph W; Clegg, Simon R; Sullivan, Leigh E; Duncan, Jennifer S; Grove-White, Dai H; Carter, Stuart D; Evans, Nicholas J

    2015-12-01

    Contagious ovine digital dermatitis (CODD) is an important cause of infectious lameness in sheep in the UK and Ireland and has a severe impact on the welfare of affected individuals. The three treponemal phylogroups Treponema medium/Treponema vincentii-like, Treponema phagedenis-like and Treponema pedis spirochaetes have been associated with clinical CODD lesions and are considered to be a necessary cause of disease. There are scant data on the antimicrobial susceptibility of the treponemes cultured from CODD lesions. The aim of this study was to determine in vitro the miniumum inhibitory concentration/ minimum bactericidal concentration (MIC/MBC) of antimicrobials used in the sheep industry for isolates of the three CODD associated treponeme phylogroups T. medium/T. vincentii-like, T. phagedenis-like and T. pedis. Twenty treponeme isolates; from 19 sheep with clinical CODD lesions. A microdilution method was used to determine in vitro the MIC/MBC of 10 antimicrobial agents for 20 treponeme isolates (five T. medium/T. vincentii-like, 10 T. phagedenis-like and five T. pedis). The antimicrobials tested were penicillin G, amoxicillin, oxytetracycline, tilmicosin, lincomycin, spectinomycin, tylosin, tildipirosin, tulathromycin and gamithromycin. The treponeme isolates tested showed low MICs and MBCs to all 10 antimicrobials tested. They were most susceptible to gamithromycin and tildipirosin (MIC90: 0.0469 mg/L), and were least susceptible to lincomycin, spectinomycin and oxytetracycline (MIC90: 48 mg/L, 24 mg/L and 3 mg/L, respectively). These data are comparable to in vitro antimicrobial susceptibility data for treponemes cultured from bovine digital dermatitis lesions. Dependent on local licensing, penicillin and tilmicosin appear to be the best candidates for future in vivo studies. © 2015 The Authors. Veterinary Dermatology published by John Wiley & Sons Ltd on behalf of the ESVD and ACVD.

  10. Physical and Antimicrobial Properties of Starch-PVA Blend Films as Affected by the Incorporation of Natural Antimicrobial Agents.

    Science.gov (United States)

    Cano, Amalia; Cháfer, Maite; Chiralt, Amparo; González-Martínez, Chelo

    2015-12-26

    In this work, active films based on starch and PVA (S:PVA ratio of 2:1) were developed by incorporating neem (NO) and oregano essential oils (OEO). First, a screening of the antifungal effectiveness of different natural extracts (echinacea, horsetail extract, liquid smoke and neem seed oil) against two fungus ( P. expansum and A. niger ) was carried out. The effect of NO and OEO incorporation on the films' physical and antimicrobial properties was analyzed. Only composite films containing OEO exhibited antibacterial and antifungal activity. Antibacterial activity occurred at low OEO concentration (6.7%), while antifungal effect required higher doses of OEO in the films. Incorporation of oils did not notably affect the water sorption capacity and water vapor barrier properties of S-PVA films, but reduced their transparency and gloss, especially at the highest concentrations. The mechanical response of the S-PVA films was also negatively affected by oil incorporation but this was only relevant at the highest oil ratio (22%). S-PVA films with 6.7% of OEO exhibited the best physical properties, without significant differences with respect to the S-PVA matrix, while exhibiting antibacterial activity. Thus, the use of OEO as a natural antimicrobial incorporated into starch-PVA films represents a good and novel alternative in food packaging applications.

  11. Physical and Antimicrobial Properties of Starch-PVA Blend Films as Affected by the Incorporation of Natural Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Amalia Cano

    2015-12-01

    Full Text Available In this work, active films based on starch and PVA (S:PVA ratio of 2:1 were developed by incorporating neem (NO and oregano essential oils (OEO. First, a screening of the antifungal effectiveness of different natural extracts (echinacea, horsetail extract, liquid smoke and neem seed oil against two fungus (P. expansum and A. niger was carried out. The effect of NO and OEO incorporation on the films’ physical and antimicrobial properties was analyzed. Only composite films containing OEO exhibited antibacterial and antifungal activity. Antibacterial activity occurred at low OEO concentration (6.7%, while antifungal effect required higher doses of OEO in the films. Incorporation of oils did not notably affect the water sorption capacity and water vapor barrier properties of S-PVA films, but reduced their transparency and gloss, especially at the highest concentrations. The mechanical response of the S-PVA films was also negatively affected by oil incorporation but this was only relevant at the highest oil ratio (22%. S-PVA films with 6.7% of OEO exhibited the best physical properties, without significant differences with respect to the S-PVA matrix, while exhibiting antibacterial activity. Thus, the use of OEO as a natural antimicrobial incorporated into starch-PVA films represents a good and novel alternative in food packaging applications.

  12. Applications of the pharmacokinetic/pharmacodynamic (PK/PD) analysis of antimicrobial agents.

    Science.gov (United States)

    Asín-Prieto, Eduardo; Rodríguez-Gascón, Alicia; Isla, Arantxazu

    2015-05-01

    The alarming increase of resistance against multiple currently available antibiotics is leading to a rapid lose of treatment options against infectious diseases. Since the antibiotic resistance is partially due to a misuse or abuse of the antibiotics, this situation can be reverted when improving their use. One strategy is the optimization of the antimicrobial dosing regimens. In fact, inappropriate drug choice and suboptimal dosing are two major factors that should be considered because they lead to the emergence of drug resistance and consequently, poorer clinical outcomes. Pharmacokinetic/pharmacodynamic (PK/PD) analysis in combination with Monte Carlo simulation allows to optimize dosing regimens of the antibiotic agents in order to conserve their therapeutic value. Therefore, the aim of this review is to explain the basis of the PK/PD analysis and associated techniques, and provide a brief revision of the applications of PK/PD analysis from a therapeutic point-of-view. The establishment and reevaluation of clinical breakpoints is the sticking point in antibiotic therapy as the clinical use of the antibiotics depends on them. Two methodologies are described to establish the PK/PD breakpoints, which are a big part of the clinical breakpoint setting machine. Furthermore, the main subpopulations of patients with altered characteristics that can condition the PK/PD behavior (such as critically ill, elderly, pediatric or obese patients) and therefore, the outcome of the antibiotic therapy, are reviewed. Finally, some recommendations are provided from a PK/PD point of view to enhance the efficacy of prophylaxis protocols used in surgery. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Reductive destruction and decontamination of aqueous solutions of chlorinated antimicrobial agent using bimetallic systems

    Energy Technology Data Exchange (ETDEWEB)

    Ghauch, Antoine, E-mail: antoine.ghauch@aub.edu.lb [American University of Beirut, Faculty of Arts and Sciences, Department of Chemistry, P.O. Box 11-0236 Riad El Solh, 1107-2020 Beirut (Lebanon); Tuqan, Almuthanna [American University of Beirut, Faculty of Arts and Sciences, Department of Chemistry, P.O. Box 11-0236 Riad El Solh, 1107-2020 Beirut (Lebanon)

    2009-05-30

    Palladium, ruthenium and silver were investigated as catalysts for the dechlorination of dichlorophen (DCP, 2,2'-methylenebis(4-chlorophenol)), an antimicrobial and anthelmintic agent largely used as algicide, fungicide and bactericide. Experiments were undertaken under oxic and anoxic conditions for experimental durations up to 180 min (3 h). The anoxic conditions were achieved by purging the solutions with nitrogen gas. Reactions were performed in a 12 {+-} 0.5 mg L{sup -1} DCP solution (V = 20 mL) using 0.8 g of Fe{sup 0} (40 g L{sup -1}). Along with micrometric Fe{sup 0}, five Fe{sup 0}-plated systems were investigated: Pd (1%), Ru (0.01%), Ru (0.1%), Ru (1%) and Ag (1%). Metal plating was controlled by atomic absorption spectroscopy. DCP degradation was monitored using: (i) two HPLC devices, (ii) ion chromatography, (iii) UV and fluorescence spectrophotometry. Results indicated: (i) total dechlorination with Fe/Pd, (ii) partial dechlorination (40%) with Fe/Ru, and no reaction with Fe/Ag. DCP is vanished completely after 90 min of contact with Fe/Pd following a first order kinetic. The observed degradation rate k{sub obs} was about (3.98 {+-} 0.10) x 10{sup -2} min{sup -1}, the calculated half-life t{sub 1/2} about 17.4 {+-} 0.9 min and a t{sub 50} about 10.1 {+-} 0.5 min. A DCP degradation pathway map was also proposed.

  14. [Antimycoplasmal activities of ofloxacin and commonly used antimicrobial agents on Mycoplasma gallisepticum].

    Science.gov (United States)

    Takahashi, I; Yoshida, T

    1989-05-01

    In vitro activities of ofloxacin (OFLX), a new quinolone derivative, against 29 strains of Mycoplasma gallisepticum was compared with those of 4 commonly used antimicrobial agents, doxycycline (DOXY), tylosin (TS), spectinomycin (SPCM) and thiamphenicol (TP). Antimycoplasmal activities of the drugs were evaluated on the MIC (final MIC) and MPC (minimum mycoplasmacidal concentration) values which were determined by a broth dilution procedure. The following results were obtained. 1. The MIC90s of OFLX and DOXY were both 0.20 micrograms/ml. The MICs of TS were distributed through a wide range (less than or equal to 0.006 - 0.78 micrograms/ml), and its MIC90 was 0.78 micrograms/ml. Of 29 M. gallisepticum strains, 27.6% were recognized as TS-resistant. The MIC90 values of SPCM and TP were 1.56 micrograms/ml and 3.13 micrograms/ml, respectively. The MIC90 of OFLX was equal to that of DOXY and 4- to 16-fold smaller than the values of the other 3 antibiotics. 2. The MPC of OFLX was the lowest among the antibiotics tested, its MPC90 value was 0.39 micrograms/ml and was followed by DOXY (1.56 micrograms/ml). The MPCs of TS were distributed in a wide range (0.012 - 3.13 micrograms/ml), and its MPC90 was 3.13 micrograms/ml. The MPC90 values of SPCM and TP were both 6.25 micrograms/ml. Therefore, the mycoplasmacidal activity of OFLX evaluated with MPC90 values was 4- to 16-fold greater than those of the other 4 antibiotics.

  15. The effect of radiopacifiers agents on pH, calcium release, radiopacity, and antimicrobial properties of different calcium hydroxide dressings.

    Science.gov (United States)

    Ordinola-Zapata, Ronald; Bramante, Clovis Monteiro; García-Godoy, Franklin; Moldauer, Bertram Ivan; Gagliardi Minotti, Paloma; Tercília Grizzo, Larissa; Duarte, Marco Antonio Hungaro

    2015-07-01

    The aim of this study was to evaluate the antimicrobial activity, pH level, calcium ion release, and radiopacity of calcium hydroxide pastes associated with three radiopacifying agents (iodoform, zinc oxide, and barium sulfate). For the pH and calcium release tests, 45 acrylic teeth were utilized and immersed in ultrapure water. After 24 h, 72 h, and 7 days the solution was analyzed by using a pH meter and an atomic absorption spectrophotometer. Polyethylene tubes filled with the pastes were used to perform the radiopacity test. For the antimicrobial test, 25 dentin specimens were infected intraorally in order to induce the biofilm colonization and treated with the pastes for 7 days. The Live/Dead technique and a confocal microscope were used to obtain the ratio of live cells. Parametric and nonparametric statistical tests were performed to show differences among the groups (P calcium release test on the 7th day (P > 0.05). The calcium hydroxide/iodoform samples had the highest radiopacity and antimicrobial activity against the biofilm-infected dentin in comparison to the other pastes (P Calcium hydroxide mixed with 17% iodoform and 35% propylene glycol into a paste had the highest pH, calcium ion release, radiopacity, and the greatest antimicrobial action versus similar samples mixed with BaSO4 or ZnO. © 2015 Wiley Periodicals, Inc.

  16. Screening of commercial and pecan shell-extracted liquid smoke agents as natural antimicrobials against foodborne pathogens.

    Science.gov (United States)

    Van Loo, Ellen J; Babu, D; Crandall, Philip G; Ricke, Steven C

    2012-06-01

    Liquid smoke extracts have traditionally been used as flavoring agents, are known to possess antioxidant properties, and serve as natural alternatives to conventional antimicrobials. The antimicrobial efficacies of commercial liquid smoke samples may vary depending on their source and composition and the methods used to extract and concentrate the smoke. We investigated the MICs of eight commercial liquid smoke samples against Salmonella Enteritidis, Staphylococcus aureus, and Escherichia coli . The commercial liquid smoke samples purchased were supplied by the manufacturer as water-based or concentrated extracts of smoke from different wood sources. The MICs of the commercial smokes to inhibit the growth of foodborne pathogens ranged from 0.5 to 6.0% for E. coli, 0.5 to 8.0% for Salmonella, and 0.38 to 6% for S. aureus. The MIC for each liquid smoke sample was similar in its effect on both E. coli and Salmonella. Solvent-extracted antimicrobials prepared using pecan shells displayed significant differences between their inhibitory concentrations depending on the type of solvent used for extraction. The results indicated that the liquid smoke samples tested in this study could serve as effective natural antimicrobials and that their inhibitory effects depended more on the solvents used for extraction than the wood source.

  17. Antimicrobial and Cytotoxic Activity of Three Bitter Plants-Enhydra fluctuans, Andrographis Peniculata and Clerodendrum Viscosum.

    Directory of Open Access Journals (Sweden)

    M. Ruhul Amin

    2012-08-01

    Full Text Available Purpose: In this study, three important medicinal plants (Enhydra fluctuans Lour, Clerodendrum viscosum Vent and Andrographis peniculata Wall of Bangladesh were investigated to analyze their antimicrobial and cytotoxic activities against some pathogenic microorganisms and Artemia salina (brine shrimp nauplii. Methods: The coarse powder material of leaves of each plant was extracted separately with methanol and acetone to yield methanol extracts of leaves of Enhydra fluctuans (MLE, Clerodendrum viscosum (MLC and Andrographis peniculata (MLA, and acetone extracts of leaves of Enhydra fluctuans (ALE, Clerodendrum viscosum (ALC and Andrographis peniculata (ALA. The disc diffusion method and the method described by Meyer were used to determine the antimicrobial and cytotoxic activities of each plant extract. Results: Among the test samples, MLE and ALE showed comparatively better antimicrobial activity against a number of bacteria and fungi with inhibition zones in the range of 06-15 mm and according to the intensity of activity, the efficacy against microorganisms were found in the order of Enhydra fluctuans> Andrographi speniculata> Clerodendrum viscosum. In cytotoxicity assay, all samples were found to be active against brine shrimp nauplii (Artemia salina and ALA produced lowest LC50 value (7.03 μg/ml. Conclusion: Enhydra fluctuans and Andrographi speniculata possesses significant antimicrobial and cytotoxic activities.

  18. Antimicrobial and antioxidant activities of medicinal plant Glycyrrhiza glabra var. glandulifera from different habitats

    Directory of Open Access Journals (Sweden)

    Faruk Karahan

    2016-07-01

    Full Text Available In this study, the antimicrobial and antioxidant activities of root methanolic extracts of Glycyrrhiza glabra var. glandulifera (Waldst. & Kit. Boiss. (Fabaceae were investigated. Plant samples were collected from different habitats in the East Mediterranean part of Turkey. The plant extracts were evaluated for antimicrobial activities against nine bacterial and two yeast strains using disc-diffusion and minimum inhibitory concentration methods. The antioxidant activity was determined by using the DPPH (1,1-diphenyl-2-picrylhydrazyl method. The antimicrobial assays indicated that the plant root extracts were more effective against Gram-positive bacteria than against Gram-negative ones. In addition, the extracts had higher antimicrobial effect against Candida species than against bacteria. The extracts showed good antioxidant activity, with a median inhibitory concentration (IC50 in the range of 588 ± 0.86 µg/mL to 2190 ± 1.73 µg/mL. Results indicated that different environmental conditions in each habitat might affect the contents of chemical compounds and biological activity in the natural licorice populations of. This study also supported the traditional use of licorice and as well as suggested that it may also be its beneficial role in the treatment of other infections. The obtained results indicated that different environmental conditions in each habitat might affect the contents of chemical compounds and the biological activity in the natural licorice populations.

  19. Synergism between plant extract and antimicrobial drugs used on Staphylococcus aureus diseases

    Directory of Open Access Journals (Sweden)

    Joyce Elaine Cristina Betoni

    2006-06-01

    Full Text Available Searches for substances with antimicrobial activity are frequent, and medicinal plants have been considered interesting by some researchers since they are frequently used in popular medicine as remedies for many infectious diseases. The aim of this study was to verify the synergism between 13 antimicrobial drugs and 8 plant extracts - "guaco" (Mikania glomerata, guava (Psidium guajava, clove (Syzygium aromaticum, garlic (Allium sativum, lemongrass (Cymbopogon citratus, ginger (Zingiber officinale, "carqueja" (Baccharis trimera, and mint (Mentha piperita - against Staphylococcus aureus strains, and for this purpose, the disk method was the antimicrobial susceptibility test performed. Petri dishes were prepared with or without dilution of plant extracts at sub-inhibitory concentrations in Mueller-Hinton Agar (MHA, and the inhibitory zones were recorded in millimeters. In vitro anti-Staphylococcus aureus activities of the extracts were confirmed, and synergism was verified for all the extracts; clove, guava, and lemongrass presented the highest synergism rate with antimicrobial drugs, while ginger and garlic showed limited synergistic capacity.

  20. A STUDY OF ANTIMICROBIAL ACTIVITY OF FOAM-WASHING AGENT SPECIMENS AT ACIDIC pH VALUES

    Directory of Open Access Journals (Sweden)

    Strilets O. P.

    2017-06-01

    Full Text Available Introduction. It is well-known that any parapharmaceutical substance, in particular, foam-washing agents comprising water in combination with detergents, extracts, water-soluble vitamins, viscosity regulators, pH, etc., is the ideal environment for microbial growth. Therefore, it is indispensable to use preservatives to protect any foam-washing agent from possible contamination by microorganisms. Their main advantages are: presence of a single antimicrobial and antifungal effect, expanded range of effects, decrease in the risk of resistance of microorganisms and decrease in the toxicity and concentration of the preserving mixture. In this regard, the shelf life of parapharmaceutical substances is not provided through the use of large quantities of preservatives, but thanks to their rational combination. Materials and Methods. For this study, we have made a number of samples of foam washing bases with a number of preservatives, which are often used in developing foam-washing agents with acidic pH value, namely: sample number 1 – foam washing base + sodium benzoate; sample number 2 – foam washing base + «Euxyl K300» (phenoxyethanol, methylparaben, bulylparaben, ethylparaben, propylparaben, isobutylaraben; sample number 3 – foam washing base + «Germaben II» (polypropylene glycol, diazolium dinomovine, methylparaben, propylparaben; sample number 4 – foam washing base + «Nipaquard CMB» (benzyl alcohol, triethylene glycol, chloromethylisothiazoline, methylisothiazoline. The concentration of preservative in each sample was 0.1% (average concentration that is recommended for developing foam-washing agents. The antimicrobial activity of prototype gels was studied in vitro by diffusion in agar (“wells” method. The antimicrobial activity was measured immediately after sample preparation. All the studies were performed in aseptic conditions using a laminar box (biological safety cabinet AS2-4E1 "Esco" Indonesia. Results. According to the

  1. pH Dependent Antimicrobial Peptides and Proteins, Their Mechanisms of Action and Potential as Therapeutic Agents

    Directory of Open Access Journals (Sweden)

    Erum Malik

    2016-11-01

    and hydrogel delivery systems. Nonetheless, many pH dependent AMPs and antimicrobial proteins have yet to be fully characterized and these molecules, as a whole, represent an untapped source of novel biologically active agents that could aid fulfillment of the urgent need for alternatives to conventional antibiotics, helping to avert a return to the pre-antibiotic era.

  2. Modulation of the multidrug efflux pump EmrD-3 from Vibrio cholerae by Allium sativum extract and the bioactive agent allyl sulfide plus synergistic enhancement of antimicrobial susceptibility by A. sativum extract.

    Science.gov (United States)

    Bruns, Merissa M; Kakarla, Prathusha; Floyd, Jared T; Mukherjee, Mun Mun; Ponce, Robert C; Garcia, John A; Ranaweera, Indrika; Sanford, Leslie M; Hernandez, Alberto J; Willmon, T Mark; Tolson, Grace L; Varela, Manuel F

    2017-10-01

    The causative agent of cholera, Vibrio cholerae, is a public health concern. Multidrug-resistant V. cholerae variants may reduce chemotherapeutic efficacies of severe cholera. We previously reported that the multidrug efflux pump EmrD-3 from V. cholerae confers resistance to multiple structurally distinct antimicrobials. Medicinal plant compounds are potential candidates for EmrD-3 efflux pump modulation. The antibacterial activities of garlic Allium sativum, although poorly understood, predicts that a main bioactive component, allyl sulfide, modulates EmrD-3 efflux. Thus, we tested whether A. sativum extract acts in synergy with antimicrobials and that a main bioactive component allyl sulfide inhibits EmrD-3 efflux. We found that A. sativum extract and allyl sulfide inhibited ethidium bromide efflux in cells harboring EmrD-3 and that A. sativum lowered the MICs of multiple antibacterials. We conclude that A. sativum and allyl sulfide inhibit EmrD-3 and that A. sativum extract synergistically enhances antibacterial agents.

  3. Antimicrobial Activity Of Some Medicinal Plants Used By Herbalists ...

    African Journals Online (AJOL)

    The aqueous extracts from medicinal plants commonly used by herbalists in Mbeere, and Embu districts of Eastern province, Kenya, were tested for their inhibitory activity against three selected strains of bacteria. All the selected plant extracts (infusions: 1.0g sample in 100 ml water) investigated showed activity against ...

  4. Antimicrobial activity of some endemic plant species from Turkey

    African Journals Online (AJOL)

    SERVER

    2007-08-06

    Aug 6, 2007 ... Antibacterial and antifungal activity of Heracleum sphondylium subsp. arvinense. Afr. J. Biotechnol. 5: 1087-1089. Ertürk Ö (2006). Antibacterial and antifungal activity of ethanolic extracts from eleven spice plants. Biologia. 61: 275-278. Fazly Bazzaz BS, Haririzadeh G (2003). Screening of Iranian plants for.

  5. Evaluation of the Antimicrobial Activity of Some Medicinal Plants ...

    African Journals Online (AJOL)

    Purpose: To evaluate the anti-enterobacterial potential of nine ethnobotanically selected plants traditionally used in different parts of India for the treatment of gastrointestinal disorders such as cholera, diarrhea or dysentery. Methods: The methanol extracts of these plants were screened for antibacterial activity against 11 ...

  6. Extraction of essential oils from native plants and algae from the coast of Peniche (Portugal: antimicrobial and antioxidant activity.

    Directory of Open Access Journals (Sweden)

    Clélia Neves Afonso

    2014-06-01

    Full Text Available Coastal areas are highly complex and dynamic ecosystem of interface between land, sea and atmosphere, which also suffer biotic influences. These areas play several important ecological functions, and here we can find an enormous biodiversity. The coastline of Portugal features a high number of endemic flora and vegetation with the potential to provide functional compounds that may provide physiological benefits at nutritional and therapeutic levels, as sources of bioactive substances with antimicrobial, antioxidant, antifungal, antitumalr and anti-inflammatory activity. Among these compounds, we find essential oils, also known as volatile oils, which are a result of secondary metabolism of aromatic plants, containing a large number of substances with varied chemical composition that can be obtained by different methods of extraction. The aim of this study was to extract essential oils of native plants and seaweeds from the coast of Peniche by hydrodistillation in Clevenger apparatus, with optimization of the purification process. Extracted essential oils were tested as to their ability as antibacterial and antifungal agents, and also as antioxidants. The plants studied for this purpose were Inula chritmoides L., Juniperus phoenicea subsp. turbinata (Guss. Nyman, Daucus carota spp. halophilus and the seaweeds Fucus spiralis L., Codium tomentosum Stackhouse, Stypocaulon scoparium (Linnaeus Kützing and Plocamium cartilagineum (Linnaeus P.S.Dixon. The antimicrobial ability was tested in two bacteria species, Bacillus subtilis and Escherichia coli and in the yeast Saccharomyces cerevisiae, using standard procedures. The antioxidant potential was evaluated and from the results obtained, we can conclude that the essential oils extracted by the hydrodistillation method of plants and algae contain bioactive compounds present in its constitution with interesting bio-activity that can offer significant benefits and biotechnological relevance.

  7. Effect of Antimicrobials on Salmonella Spp. Strains Isolated from Poultry Processing Plants

    Directory of Open Access Journals (Sweden)

    L Mion

    Full Text Available ABSTRACT The routine use of antimicrobials in animal production for the treatment of infections, disease prevention, or as growth promoters is a predisposing factor for the development and dissemination of antimicrobial resistance. In food industries, sanitizers are used for the control of microbial colonization, and their efficacy depends on contact time and on the dilution of the products used. The present study assessed the effect of 12 antimicrobials and four commercial sanitizers on 18 Salmonella spp. strains isolated from poultry processing plants. None of the evaluated antimicrobials was 100% effective against the tested Salmonella spp. strains; however, 94% of the isolates were susceptible to ciprofloxacin, 77% to amoxicillin + clavulanic acid and to ampicillin, and 72% to enrofloxacin, whereas 100% of the isolates were resistant to penicillin G, 16% to tetracycline, and 11% to sulfonamide. The tested Salmonella spp. strains were 100% inhibited by peracetic acid after five minutes of contact, 0.5% by quaternary ammonium after 15 minutes, and 85.7% by chlorhexidine after 15 minutes. The results indicate the importance of testing of efficacy of antimicrobials used in animal production and in public health to monitor their action and the development of resistance.

  8. Proposed quality control guidelines for National Committee for Clinical Laboratory Standards Susceptibility Tests using the veterinary antimicrobial agent tiamulin.

    Science.gov (United States)

    Pfaller, M A; Jones, R N; Walter, D H

    2001-01-01

    Quality control guidelines for standardized antimicrobial susceptibility test methods are critical for the continuing accuracy of these clinical tests. In this report, quality control limits were proposed for the veterinary antimicrobial agent tiamulin with minimum inhibitory concentration (MIC) ranges of three or four log(2) dilution steps in two different medium formulations. Disk diffusion zone diameter ranges were proposed for tiamulin tested against Actinobacillus pleuropneumoniae ATCC 27090 (12-18 mm) and Staphylococcus aureus ATCC 25923 (25-32 mm). The data from eight participating laboratories produced 100% of results within proposed MIC limits (8-32 microg/mL), and 95.8-97.0% of zones were found within suggested zone diameter QC guidelines. These proposed QC ranges should be validated by in-use results from veterinary clinical laboratories.

  9. Synthesis and characterization of silver-copper core-shell nanoparticles using polyol method for antimicrobial agent

    Science.gov (United States)

    Hikmah, N.; Idrus, N. F.; Jai, J.; Hadi, A.

    2016-06-01

    Silver and copper nanoparticles are well-known as the good antimicrobial agent. The nano-size of particles influences in enhancing the antimicrobial activity. This paper discusses the effect of molarity on the microstructure and morphology of silver-copper core-shell nanoparticles prepared by a polyol method. In this study, silver-copper nanoparticles are synthesized through the green approach of polyol method using ethylene glycol (EG) as green solvent and reductant, and polyoxyethylene-(80)-sorbitan monooleate (Tween 80) as a nontoxic stabilizer. The phase and morphology of silver-copper nanoparticles are characterized by X-ray diffraction (XRD) and Field emission scanning electron microscope (FESEM) and Transmission electron microscope (TEM). The results XRD confirm the pure crystalline of silver and copper nanoparticles with face-centered cubic (FCC) structure. FESEM and TEM analysis confirm the existence of Ag and Cu nanoparticles in core-shell shape.

  10. Design and synthesis of some new 2,3'-bipyridine-5-carbonitriles as potential anti-inflammatory/antimicrobial agents.

    Science.gov (United States)

    Elzahhar, Perihan A; Elkazaz, Salwa; Soliman, Raafat; El-Tombary, Alaa A; Shaltout, Hossam A; El-Ashmawy, Ibrahim M; Abdel Wahab, Abeer E; El-Hawash, Soad A

    2017-08-01

    Inflammation may cause accumulation of fluid in the injured area, which may promote bacterial growth. Other reports disclosed that non-steroidal anti-inflammatory drugs may enhance progression of bacterial infection. This work describes synthesis of new series of 2,3'-bipyridine-5-carbonitriles as structural analogs of etoricoxib, linked at position-6 to variously substituted thio or oxo moieties. Biological screening results revealed that compounds 2b, 4b, 7e and 8 showed significant acute and chronic AI activities and broad spectrum of antimicrobial activity. In addition, similarity ensemble approach was applied to predict potential biological targets of the tested compounds. Then, pharmacophore modeling study was employed to determine the most important structural parameters controlling bioactivity. Moreover, title compounds showed physicochemical properties within those considered adequate for drug candidates. This study explored the potential of such series of compounds as structural leads for further modification to develop a new class of dual AI-antimicrobial agents.

  11. Antimicrobial effects of 14 Medicinal plant speices of Dashti in Bushehr province

    Directory of Open Access Journals (Sweden)

    Afshin Shirkani

    2014-04-01

    Full Text Available Background: Medicinal plants are used in treating diseases as low-risk, available and inexpensive natural materials with higher consumption by people comparing to synthetic antimicrobial drugs. Excessive use of antimicrobial drugs led to medicinal resistance against different antibiotics in most bacteria. Material and Methods: In this empirical experimental study, the antimicrobial effects of methanolic extracts of 14 medicinal plants species were examined comparing to conventional therapeutic antibiotics against standard bacterial strains. The plant species were collected from dashti of Bushehr province.The methanolic extract of the cultivations broths were prepared in different concentrations (0/25%, 0/5%, 1%, 2% and 4% dissolved in DMSO/ Methanolic solution and their antibacterial potency respected on the inhibition zone using the disc diffusion assay. Results: The maximum effects on Escherichia coli belonged to Arundo donax and the least effects belonged to Calotropis procera. The maximum effects on Staphylococcus aureus belonged to Lawsonia inermis and the least effects belonged to Calotropis procera. The maximum effects on Micrococcus luteus belonged to Phoeniex doctylifera and the least effects belonged to Oligomeris baccatus. The maximum effects on Klebsiella pneumonia belonged to mnocarpos decander and the least effects belonged Oligomeris baccatus. The maximum effects on pseudomonas aeroginosa belonged to Arundo donax. The maximum effects on Bacillus subtilis belonged to Astragalus arbusculinus. Conclusion: The antimicrobial effects of 4% methanolic extracts of Arundo donax were comparable to Cephalotin (30mcg, Piperacilin (30mcg and Amikacin (30mcg against Escherichia coli and pseudomonas aeroginosa. The antimicrobial effects of %4 extracts of Lawsonia inermis were similar to Amikacin (30mcg and Chloramphenicol (30mcg against Klebsiella penumoniae.

  12. Distribution and antimicrobial potential of endophytic fungi associated with ethnomedicinal plant Melastoma malabathricum L.

    Science.gov (United States)

    Mishra, Vineet Kumar; Singh, Garima; Passari, Ajit Kumar; Yadav, Mukesh Kumar; Gupta, Vijai Kumar; Singh, Bhim Pratap

    2016-03-01

    Distributions of endophytic fungi associated with ethnomedicinal plant Melastoma malabathricum L. was studied and 91 isolates belonging to 18 genera were recovered. The isolates were distributed to sordariomycetes (62.63%), dothideomycetes (19.78%), eurotiomycetes (7.69%), zygomycetes (4.19%), agaricomycetes (1.09%), and mycelia sterilia (4.39%). Based on colony morphology and examination of spores, the isolates were classified into 18 taxa, of which Colletotrichum, Phomopsis and Phoma were dominant, their relative frequencies were 23.07%, 17.58% and 12.08% respectively. The colonization rate of endophytic fungi was determined and found to be significantly higher in leaf segments (50.76%), followed by root (41.53%) and stem tissues (27.69%). All the isolates were screened for antimicrobial activity and revealed that 26.37% endophytic fungi were active against one or more pathogens. Twenty four isolates showing significant antimicrobial activity were identified by sequencing the ITS1-5.8S-ITS2 region of rRNA gene. Results indicated that endophytic fungi associated with leaf were functionally versatile as they showed antimicrobial activity against most of the tested pathogens. The endophytic fungi Diaporthe phaseolorum var. meridionalis (KF193982) inhibited all the tested bacterial pathogens, whereas, Penicillium chermesinum (KM405640) displayed most significant antifungal activity. This seems to be the first hand report to understand the distribution and antimicrobial ability of endophytic fungi from ethno-medicinal plant M. malabathricum.

  13. Plants as antimalarial agents in Sub-Saharan Africa.

    Science.gov (United States)

    Chinsembu, Kazhila C

    2015-12-01

    Although the burden of malaria is decreasing, parasite resistance to current antimalarial drugs and resistance to insecticides by vector mosquitoes threaten the prospects of malaria elimination in endemic areas. Corollary, there is a scientific departure to discover new antimalarial agents from nature. Because the two antimalarial drugs quinine and artemisinin were discovered through improved understanding of the indigenous knowledge of plants, bioprospecting Sub-Saharan Africa's enormous plant biodiversity may be a source of new and better drugs to treat malaria. This review analyses the medicinal plants used to manage malaria in Sub-Saharan Africa. Chemical compounds with antiplasmodial activity are described. In the Sub-Saharan African countries cited in this review, hundreds of plants are used as antimalarial remedies. While the number of plant species is not exhaustive, plants used in more than one country probably indicate better antimalarial efficacy and safety. The antiplasmodial data suggest an opportunity for inventing new antimalarial drugs from Sub-Saharan-African flora. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. In vitro antimicrobial activity and antagonistic effect of essential oils from plant species.

    Science.gov (United States)

    Toroglu, Sevil

    2007-07-01

    Kahramanmaras, is a developing city located in the southern part of Turkey Thymus eigii (M. Zohary and RH. Davis) Jalas, Pinus nigraAm. sub sp pallasiana and Cupressus sempervirens L. are the useful plants of the Kahramanmaras province and have been understudy since 2004 for the traditional uses of plants empiric drug, spice, herbal tea industry herbal gum and fuel. The study was designed to examine the antimicrobial activities of essential oils of these plants by the disc diffusion and minimum inhibitory concentration (MIC) methods. In addition, antimicrobial activity of Thymus eigii was researched by effects when it was used together with antibiotics and even when it was combined with other essential oils. When the results of this study were compared with vancomycin (30 mcg) and erytromycin (15 mcg) standards, it was found that Thymus eigii essential oil was particularly found to possess strongerantimicrobial activity whereas other essential oils showed susceptible or moderate activity However, antimicrobial activity changed also by in vitro interactions between antibiotics and Thymus eigii essential oil, also between essential oils of these plants and that of Thymus eigii causing synergic, additive, antagonist effect.

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

    Science.gov (United States)

    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

  16. Urinary tract infection in pregnant population, which empirical antimicrobial agent should be specified in each of the three trimesters?

    Science.gov (United States)

    Unlu, Bekir Serdar; Yildiz, Yunus; Keles, Ibrahim; Kaba, Metin; Kara, Halil; Tasin, Cuma; Erkilinc, Selcuk; Yildirim, Gulcin

    2014-05-01

    We aimed to investigate the bacterial profile and the adequacy of antimicrobial treatment in pregnant women with urinary tract infection. This retrospective observational study was conducted with 753 pregnant women who needed hospitalization because of UTI in each of the three trimesters. Midstream urine culture and antimicrobial susceptibility tests were evaluated. E. Coli was the most frequently isolated bacterial agent (82.2%), followed by Klebsiella spp. (11.2%). In each of the three trimesters, E. Coli remained the most frequently isolated bacterium (86%, 82.2%, 79.5%, respectively), followed by Klebsiella spp. (9%, 11.6%, 12.2%, respectively). Enterococcus spp. were isolated as a third microbial agent, with 43 patients (5.7%) in the three trimesters. The bacteria were found to be highly sensitive to fosfomycin, with 98-99% sensitivity for E.Coli and 88-89% for Klebsiella spp. and for Enterococcus spp. 93-100% nitrofurantoin sensitivity for each of the three trimesters. We demonstrated that E. Coli and Klebsiella spp. are the most common bacterial agents isolated from urine culture of pregnant women with UTI in each of the three trimesters. We consider fosfomycin to be the most adequate first-line treatment regimen due to high sensitivity to the drug, ease of use and safety for use in pregnancy

  17. Drug-induced liver injury due to antimicrobials, central nervous system agents, and nonsteroidal anti-inflammatory drugs.

    Science.gov (United States)

    Devarbhavi, Harshad; Andrade, Raúl J

    2014-05-01

    Antimicrobial agents including antituberculosis (anti-TB) agents are the most common cause of idiosyncratic drug-induced liver injury (DILI) and drug-induced liver failure across the world. Better molecular and genetic biomarkers are acutely needed to help identify those at risk of liver injury particularly for those needing antituberculosis therapy. Some antibiotics such as amoxicillin-clavulanate and isoniazid consistently top the lists of agents in retrospective and prospective DILI databases. Central nervous system agents, particularly antiepileptics, account for the second most common class of agents implicated in DILI registries. Hepatotoxicity from older antiepileptics such as carbamazepine, phenytoin, and phenobarbital are often associated with hypersensitivity features, whereas newer antiepileptic drugs have a more favorable safety profile. Antidepressants and nonsteroidal anti-inflammatory drugs carry very low risk of significant liver injury, but their prolific use make them important causes of DILI. Early diagnosis and withdrawal of the offending agent remain the mainstays of minimizing hepatotoxicity. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  18. Antimicrobials Treatment

    Science.gov (United States)

    Drosinos, Eleftherios H.; Skandamis, Panagiotis N.; Mataragas, Marios

    The use of antimicrobials is a common practice for preservation of foods. Incorporation, in a food recipe, of chemical antimicrobials towards inhibition of spoilage and pathogenic micro-organisms results in the compositional modification of food. This treatment is nowadays undesirable for the consumer, who likes natural products. Scientific community reflecting consumers demand for natural antimicrobials has made efforts to investigate the possibility to use natural antimicrobials such us bacteriocins and essential oils of plant origin to inhibit microbial growth.

  19. The management of risk arising from the use of antimicrobial agents in veterinary medicine in EU/EEA countries - a review.

    Science.gov (United States)

    Törneke, K; Torren-Edo, J; Grave, K; Mackay, D K J

    2015-12-01

    Antimicrobials are essential medicines for the treatment of many microbial infections in humans and animals. Only a small number of antimicrobial agents with new mechanisms of action have been authorized in recent years for use in either humans or animals. Antimicrobial resistance (AMR) arising from the use of antimicrobial agents in veterinary medicine is a concern for public health due to the detection of increasing levels of resistance in foodborne zoonotic bacteria, particularly gram-negative bacteria, and due to the detection of determinants of resistance such as Extended-spectrum beta-lactamases (ESBL) in bacteria from animals and in foodstuffs of animal origin. The importance and the extent of the emergence and spread of AMR from animals to humans has yet to be quantified. Likewise, the relative contribution that the use of antimicrobial agents in animals makes to the overall risk to human from AMR is currently a subject of debate that can only be resolved through further research. Nevertheless, risk managers have agreed that the impact on public health of the use of antimicrobials in animals should be minimized as far as possible and a variety of measures have been introduced by different authorities in the EU to achieve this objective. This article reviews a range of measures that have been implemented within European countries to reduce the occurrence and the risk of transmission of AMR to humans following the use of antimicrobial agents in animals and briefly describes some of the alternatives to the use of antimicrobial agents that are being developed. © 2015 John Wiley & Sons Ltd.

  20. Research Concerning Antimicrobial Activities of Some Essential Oils Extracted from Plants

    Directory of Open Access Journals (Sweden)

    ADRIANA DALILA CRISTE

    2014-10-01

    Full Text Available The principal components of some essential oils extracted from plants have been found to have microbial activity. Depending on the concentration, the members of this class are known to be bactericide or bacteriostatic. Their action mechanism is unclear, but some studies suggest that the compounds penetrate the cell, where they interfere with cellular metabolism. The purpose of this study was to evaluate the antimicrobial activity of 5 essential oils extracted from plants on Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus and Bacillus cereus and to determinate how different amount of the used oils can influence the results of inhibition tests. These results showed that mainly all the natural extracts presented an antimicrobial effect. Thereby, some extracts were more efficient than another and the order is: Eucalyptus globulus (eucalyptus, Mentha piperita (mint, Lavandula angustifolia (lavender, Matricaria chamomilla (chamomile, Calendula officinalis (calendula.

  1. [The obtainment and characteristics of Kalanchoe pinnata L. plants expressing the artificial gene of the cecropin P1 antimicrobial peptide].

    Science.gov (United States)

    Zakharchenko, N S; Rukavtsova, E B; Shevchuk, T V; Furs, O V; Pigoleva, S V; Lebedeva, A A; Chulina, I A; Baidakova, L K; Bur'yanov, Ya I

    2016-01-01

    Kalanchoe pinnata L. plants bearing an artificial CP1 gene encoding the cecropin P1 antimicrobial peptide have been obtained. The presence of the CP1 gene in the plant genome has been confirmed by PCR. Cecropin P1 synthesis in transgenic plants has been shown by MALDI mass spectrometry and Western blotting. The obtained plants have been highly resistant to bacterial and fungal phytopathogens, and their extracts have demonstrated antimicrobial activity towards human and animal pathogens. It has been shown that transgenic plants bearing the CP1 gene can be colonized by the beneficial associative microorganisms Methylovorus mays.

  2. Antimicrobial activity of Ulopterol isolated from Toddalia asiatica (L.) Lam.: a traditional medicinal plant.

    Science.gov (United States)

    Karunai Raj, M; Balachandran, C; Duraipandiyan, V; Agastian, P; Ignacimuthu, S

    2012-03-06

    The leaves of Toddalia asiatica (L.) Lam. (Rutaceae) are widely used in folk medicine in India to treat various ailments like cough, malaria, indigestion, influenza lung diseases and rheumatism, fever, stomach ailments, cholera and diarrhea. In our earlier communication we have reported the antimicrobial study on the various extracts of the leaves and the isolation and identification of Flindersine, a quinolone alkaloid as the major active principle. In the present study, we report the antibacterial and antifungal activities of Ulopterol, a coumarin isolated as another major active antimicrobial principle. The leaves were successively extracted with hexane, chloroform, ethyl acetate, methanol and water. The extracts were studied for their antimicrobial activity against selected bacteria and fungi by using disc-diffusion method. The ethyl acetate extract which was found to possess highest antimicrobial activity was subjected to activity guided fractionation by column chromatography over silica gel. This resulted in the isolation of the coumarin, Ulopetrol, an active principle besides Flindersine which was reported by us earlier. The structure of the compound was elucidated using physical and spectroscopic data. Flindersine and Ulopterol were quantified by HPLC. Ulopterol showed activity against the bacteria viz. Staphylococcus epidermidis, Enterobacter aerogenes, Shigella flexneri, Klebsiella pneumoniae (ESBL-3967), Escherichia coli (ESBL-3984) and fungi viz. Aspergillus flavus, Candida krusei and Botrytis cinerea. Quantification by HPLC showed the content of Flindersine and Ulopterol to be 0.361% and 0.266% respectively on dry weight basis of the leaves. Ethyl acetate extract (successive extraction) contained Ulopterol, a coumarin, besides Flindersine, a quinolone alkaloid, as a major active principle in the antimicrobial studies. This is the first report of the antimicrobial activity of Ulopterol and also its first report from the plant. Copyright © 2012

  3. Current state of a dual behaviour of antimicrobial peptides-Therapeutic agents and promising delivery vectors.

    Science.gov (United States)

    Piotrowska, Urszula; Sobczak, Marcin; Oledzka, Ewa

    2017-12-01

    Micro-organism resistance is an important challenge in modern medicine due to the global uncontrolled use of antibiotics. Natural and synthetic antimicrobial peptides (AMPs) symbolize a new family of antibiotics, which have stimulated research and clinical interest as new therapeutic options for infections. They represent one of the most promising antimicrobial substances, due to their broad spectrum of biological activity, against bacteria, fungi, protozoa, viruses, yeast and even tumour cells. Besides, being antimicrobial, AMPs have been shown to bind and neutralize bacterial endotoxins, as well as possess immunomodulatory, anti-inflammatory, wound-healing, angiogenic and antitumour properties. In contrast to conventional antibiotics, which have very defined and specific molecular targets, host cationic peptides show varying, complex and very rapid mechanisms of actions that make it difficult to form an effective antimicrobial defence. Importantly, AMPs display their antimicrobial activity at micromolar concentrations or less. To do this, many peptide-based drugs are commercially available for the treatment of numerous diseases, such as hepatitis C, myeloma, skin infections and diabetes. Herein, we present an overview of the general mechanism of AMPs action, along with recent developments regarding carriers of AMPs and their potential applications in medical fields. © 2017 John Wiley & Sons A/S.

  4. Antimicrobial agents from Licaria puchuri-major and their synergistic effect with polygodial.

    Science.gov (United States)

    Himejima, M; Kubo, I

    1992-05-01

    The resistance of the seeds of Licaria puchuri-major (Lauraceae) to decomposition in nature seems to be due largely to chemical defense, since its n-hexane extract contains antimicrobial principles in quantity, with a broad antimicrobial spectrum. In order to identify the active principles, the n-hexane extract was steam-distilled to yield a distillate and a residue. Subsequent bioassay indicated that the distillate retained the original broad antimicrobial activity, while the residue exhibited almost no activity. Gc-ms analysis showed that the distillate contained four phenolic compounds, seven monoterpenes, and one sesquiterpene. In contrast, the residue contained, almost exclusively, lauric acid. In the detailed antimicrobial assay with the pure compounds identified, most of them showed broad, but moderate, antimicrobial activity. Some of the components identified in the distillate were combined with polygodial [1] in order to enhance their antifungal activity. Unexpectedly, while polygodial did not synergize the antifungal activity of any of the compounds tested, the antifungal activity of polygodial was significantly increased when combined with aromatic substances such as anethole, safrole, or methyleugenol.

  5. Identification and primary characterization of a plant antimicrobial ...

    African Journals Online (AJOL)

    Then an agar-overlay method using fully separated proteins on sodium dodecyl sulphate-polyacryliamide gel electrophoresis (SDS-PAGE) gels was used for initial determination and primary characterization of active putative defensins in the plant seeds. Clear and remarkable zones of inhibition in a region corresponding to ...

  6. Antimicrobial, Antioxidant, and Anti-Inflammatory Activities of Essential Oils of Selected Aromatic Plants from Tajikistan

    OpenAIRE

    Sharopov, Farukh; Braun, Markus Santhosh; Gulmurodov, Isomiddin; Khalifaev, Davlat; Isupov, Salomiddin; Wink, Michael

    2015-01-01

    Antimicrobial, antioxidant, and anti-inflammatory activities of the essential oils of 18 plant species from Tajikistan (Central Asia) were investigated. The essential oil of Origanum tyttanthum showed a strong antibacterial activity with both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 312.5 µg/mL for E. coli, 625 µg/mL (MIC) and 1250 µg/mL (MBC) for MRSA (methicillin-resistant Staphylococcus aureus), respectively. The essential oil of Galagan...

  7. Microwave Assisted Synthesis of Novel Imidazolopyridinyl Indoles as Potent Antioxidant and Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Jaiprakash S. Biradar

    2014-01-01

    Full Text Available We describe herein the design, synthesis, and pharmacological evaluation of novel series of imidazolopyridinyl indole analogues as potent antioxidants and antimicrobials. These novel compounds (3a–i were synthesized by reacting 3,5-disubstituted-indole-2-carboxylic acid (1a–i with 2,3-diamino pyridine (2 in excellent yield. The novel products were confirmed by their IR, 1H NMR, 13C NMR, mass spectral, and analytical data. These compounds were screened for their antioxidant and antimicrobial activities. Among the compounds tested, 3a–d showed the highest total antioxidant capacity, scavenging, and antimicrobial activities. Compounds 3c-d and 3g-h have shown excellent ferric reducing activity.

  8. ZnO and TiO{sub 2} nanoparticles as novel antimicrobial agents for oral hygiene: a review

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Shams Tabrez, E-mail: shamsalig75@gmail.com; Al-Khedhairy, Abdulaziz A. [King Saud University, Department of Zoology, College of Science (Saudi Arabia); Musarrat, Javed [AMU, Department of Agricultural Microbiology, Faculty of Agricultural Sciences (India)

    2015-06-15

    Oral cavity is inhabited by more than 25,000 different bacterial phylotypes; some of them cause systemic infections in addition to dental and periodontal diseases. Emergence of multiple antibiotic resistance among these bacteria necessitates the development of alternative antimicrobial agents that are safe, stable, and relatively economic. This review focuses on the significance of metal oxide nanoparticles, especially zinc oxide and titanium dioxide nanoparticles as supplementary antimicrobials for controlling oral infections and biofilm formation. Indeed, the ZnO NPs and TiO{sub 2} NPs have exhibited significant antimicrobial activity against oral bacteria at concentrations which is not toxic in in vivo toxicity assays. These nanoparticles are being produced at an industrial scale for use in a variety of commercial products including food products. Thus, the application of ZnO and TiO{sub 2} NPs as nanoantibiotics for the development of mouthwashes, dental pastes, and other oral hygiene materials is envisaged. It is also suggested that these NPs could serve as healthier, innocuous, and effective alternative for controlling both the dental biofilms and oral planktonic bacteria with lesser side effects and antibiotic resistance.

  9. Synthesis and Biological Evaluation of 2H-Indazole Derivatives: Towards Antimicrobial and Anti-Inflammatory Dual Agents

    Directory of Open Access Journals (Sweden)

    Jaime Pérez-Villanueva

    2017-10-01

    Full Text Available Indazole is considered a very important scaffold in medicinal chemistry. It is commonly found in compounds with diverse biological activities, e.g., antimicrobial and anti-inflammatory agents. Considering that infectious diseases are associated to an inflammatory response, we designed a set of 2H-indazole derivatives by hybridization of cyclic systems commonly found in antimicrobial and anti-inflammatory compounds. The derivatives were synthesized and tested against selected intestinal and vaginal pathogens, including the protozoa Giardia intestinalis, Entamoeba histolytica, and Trichomonas vaginalis; the bacteria Escherichia coli and Salmonella enterica serovar Typhi; and the yeasts Candida albicans and Candida glabrata. Biological evaluations revealed that synthesized compounds have antiprotozoal activity and, in most cases, are more potent than the reference drug metronidazole, e.g., compound 18 is 12.8 times more active than metronidazole against G. intestinalis. Furthermore, two 2,3-diphenyl-2H-indazole derivatives (18 and 23 showed in vitro growth inhibition against Candida albicans and Candida glabrata. In addition to their antimicrobial activity, the anti-inflammatory potential for selected compounds was evaluated in silico and in vitro against human cyclooxygenase-2 (COX-2. The results showed that compounds 18, 21, 23, and 26 display in vitro inhibitory activity against COX-2, whereas docking calculations suggest a similar binding mode as compared to rofecoxib, the crystallographic reference.

  10. ZnO and TiO2 nanoparticles as novel antimicrobial agents for oral hygiene: a review

    Science.gov (United States)

    Khan, Shams Tabrez; Al-Khedhairy, Abdulaziz A.; Musarrat, Javed

    2015-06-01

    Oral cavity is inhabited by more than 25,000 different bacterial phylotypes; some of them cause systemic infections in addition to dental and periodontal diseases. Emergence of multiple antibiotic resistance among these bacteria necessitates the development of alternative antimicrobial agents that are safe, stable, and relatively economic. This review focuses on the significance of metal oxide nanoparticles, especially zinc oxide and titanium dioxide nanoparticles as supplementary antimicrobials for controlling oral infections and biofilm formation. Indeed, the ZnO NPs and TiO2 NPs have exhibited significant antimicrobial activity against oral bacteria at concentrations which is not toxic in in vivo toxicity assays. These nanoparticles are being produced at an industrial scale for use in a variety of commercial products including food products. Thus, the application of ZnO and TiO2 NPs as nanoantibiotics for the development of mouthwashes, dental pastes, and other oral hygiene materials is envisaged. It is also suggested that these NPs could serve as healthier, innocuous, and effective alternative for controlling both the dental biofilms and oral planktonic bacteria with lesser side effects and antibiotic resistance.

  11. ZnO and TiO2 nanoparticles as novel antimicrobial agents for oral hygiene: a review

    International Nuclear Information System (INIS)

    Khan, Shams Tabrez; Al-Khedhairy, Abdulaziz A.; Musarrat, Javed

    2015-01-01

    Oral cavity is inhabited by more than 25,000 different bacterial phylotypes; some of them cause systemic infections in addition to dental and periodontal diseases. Emergence of multiple antibiotic resistance among these bacteria necessitates the development of alternative antimicrobial agents that are safe, stable, and relatively economic. This review focuses on the significance of metal oxide nanoparticles, especially zinc oxide and titanium dioxide nanoparticles as supplementary antimicrobials for controlling oral infections and biofilm formation. Indeed, the ZnO NPs and TiO 2 NPs have exhibited significant antimicrobial activity against oral bacteria at concentrations which is not toxic in in vivo toxicity assays. These nanoparticles are being produced at an industrial scale for use in a variety of commercial products including food products. Thus, the application of ZnO and TiO 2 NPs as nanoantibiotics for the development of mouthwashes, dental pastes, and other oral hygiene materials is envisaged. It is also suggested that these NPs could serve as healthier, innocuous, and effective alternative for controlling both the dental biofilms and oral planktonic bacteria with lesser side effects and antibiotic resistance

  12. KR-12-a5 is a non-cytotoxic agent with potent antimicrobial effects against oral pathogens.

    Science.gov (United States)

    Caiaffa, Karina Sampaio; Massunari, Loiane; Danelon, Marcelle; Abuna, Gabriel Flores; Bedran, Telma Blanca Lombardo; Santos-Filho, Norival Alves; Spolidorio, Denise Madalena Palomari; Vizoto, Natalia Leal; Cilli, Eduardo Maffud; Duque, Cristiane

    2017-11-01

    This study evaluated the cytotoxicity and antimicrobial activity of analogs of cationic peptides against microorganisms associated with endodontic infections. L-929 fibroblasts were exposed to LL-37, KR-12-a5 and hBD-3-1C V and chlorhexidine (CHX, control), and cell metabolism was evaluated with MTT. The minimal inhibitory concentration (MIC) and the minimal bactericidal/fungicidal concentration (MBC/MFC) of the peptides and CHX were determined against oral pathogens associated with endodontic infections. Enterococcus faecalis and Streptococcus mutans biofilms were cultivated in bovine dentin blocks, exposed to different concentrations of the most efficient antimicrobial peptide and analyzed by confocal laser scanning microscopy. CHX and peptides affected the metabolism of L-929 at concentrations > 31.25 and 500 μg ml -1 , respectively. Among the peptides, KR-12-a5 inhibited growth of both the microorganisms tested with the lowest MIC/MBC/MFC values. In addition, KR-12-a5 significantly reduced E. faecalis and S. mutans biofilms inside dentin tubules. In conclusion, KR-12-a5 is a non-cytotoxic agent with potent antimicrobial and anti-biofilm activity against oral pathogens associated with endodontic infections.

  13. Phytochemical and antimicrobial studies on essential oils of some ...

    African Journals Online (AJOL)

    USER

    2010-07-12

    Jul 12, 2010 ... chromatograph (GC) and high performance thin layer chromatography (HPTLC) analysis consisted of eugenol (56.07%), 1, 8 cineole ... Key words: Essential oils, aromatic plants, phytochemical analysis, antimicrobial activity. INTRODUCTION ... microbial agents in phytopathology, medical microbiology,.

  14. ANTIMICROBIAL ACTIVITY OF NONTRADITIONAL PLANT POLLEN AGAINST DIFFERENT SPECIES OF MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    Miroslava Kačániová

    2014-08-01

    Full Text Available The aim of this study was to detect the antimicrobial activity of four plant pollen samples to pathogenic bacteria, microscopic fungi and yeasts. Pollens of dogwood common (Cornus mas, ray mountain (Secale strictum spp. strictum, pumpkin rape (Cucurbita pepo var. styriaca and grape vine (Vitis vinifera were collected in 2010 in Slovakia. The antimicrobial effects of the four nontraditional plant pollens were tested using the agar well diffusion method. For extraction, 70% ethanol (aqueous, v/v was applied. Antimicrobial susceptibility of five different strains of bacteria - three gram positive (Listeria monocytogenes CCM 4699, Pseudomonas aeruginosa CCM 1960, Staphylococcus aureus CCM 3953 and gram negative (Salmonella enterica CCM 4420, Escherichia coli CCM 3988, as well as three different strains of microscopic fungi, Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, and three different strains of yeasts Candida albicans, Geotrichum candidum and Rhodotorula mucilaginosa, were examinated. L. monocytogenes was the most sensitive among bacteria to the three ethanol extracts of plant pollen after 24 hours of inoculation, A. flavus and C. albicans were the most sensitive microscopic fungi and yeast species, respectively.

  15. Antimicrobial and plant growth-promoting properties of the cacao endophyte Bacillus subtilis ALB629.

    Science.gov (United States)

    Falcäo, L L; Silva-Werneck, J O; Vilarinho, B R; da Silva, J P; Pomella, A W V; Marcellino, L H

    2014-06-01

    To investigate the effects of the endophyte Bacillus subtilisALB629 on the growth of cacao seedlings at early developmental stage and to evaluate its antimicrobial properties. Germinating cacao seeds were inoculated with ALB629, and seedlings growth was evaluated 30 days later. Significant increase (P cacao-grafting procedure in the field, ALB629 increased the grafting success rate (24%), indicating its protective effect. In addition, this Bacillus secretes an antagonist compound, as shown by the antifungal activity of the cell-free culture. Bacillus subtilisALB629 promotes cacao root growth, besides promoting growth of the aerial part of cacao seedlings. It has antimicrobial properties and produces an antifungal compound. ALB629 presented beneficial characteristics for cacao cultivation, being a good biological control agent candidate. Furthermore, it is a potential source of antifungal compound with potential for commercial exploitation. © 2014 The Society for Applied Microbiology.

  16. Antimicrobial Activity of Some Medicinal Plant Extracts against Multidrug Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Majid Masoumian

    2017-11-01

    Full Text Available Background: Nowadays, it is necessary to discover new and efficient antifungal or antimicrobial drugs because of increasing drug resistance organisms. Using medicinal plants for natural treatment of diseases caused by bacterial origin has mainly been considered. Objectives: In this study, the impacts of antimicrobial medicinal plants extract were compared based on four bacteria in vitro. Methods: In this experimental study, disc diffusion assay and the minimum inhibitory concentration (MIC method were used to investigate the antibacterial effects of selected plant extract elicited by two different solvent on S. aureus, E. coli, P. aeruginosa and S. enteric. Data were analyzed with a statistical software program (SPSS 16. Results: The hydro-alcoholic extract of Myrtus communis (myrtle and water extract of Cinnamomun zeylanicum (cinnamon were the most active extracts screened for antimicrobial activities against different four bacteria as tested organisms. The diameter of inhibition zones ranged from 23 to 28 mm. Comparison of the antibacterial effect of plant extracts and commercial drug revealed that the size of inhibition zone of penicillin against Staphylococcus aureus bacterium was larger than the plant extracts. However, myrtle extract at the minimum inhibitory concentration (MIC of 30 mg/mL showed more powerful antibacterial activity compared to the other extracts and even penicillin. Petroselinum crispum (parsley, Nerium oleander (Oleander and Glycyrihiza glabra (licorice were found to have the least effect on the tested bacteria. Conclusions: In the present study, plant extracts with different compounds showed antibacterial activity (especially myrtle and cinnamon. Hence, they can be used as new source for antibacterial substances.

  17. Antimicrobial screening of some plants of medicinal importance

    International Nuclear Information System (INIS)

    Mehjabeen, A.; Ahmad, M.; Zia-ul-Haq, M.; Wazir, A.; Jahan, N.

    2011-01-01

    Methanolic extracts of Solanum nigrum (leaves and seeds of both black and red varieties), Elettaria cardamomum Cuscuta reflexa and Cinnamomum camphora were tested in vitro for their antibacterial and antifungal activities. Antibacterial study performed against six bacteria viz., Escherichia coli, Citrobacter, Shigella flexenari, Staphylococcus aureus, Pseudomonas aeruginosa and Yersinia aldovae indicated that investigated plants have potent activity against all microorganisms. The antifungal activity of these extracts was performed against six fungi, viz., Saccharomyces cereviciae, Aspergillus parasiticus, Trichophyton rubrum, Macrophomina, Fusarium solani and Candida albicans. The extracts showed moderate as well as significant activity against different fungal strains. (author)

  18. Influence of radiopacifying agents on the solubility, pH and antimicrobial activity of portland cement.

    Science.gov (United States)

    Weckwerth, Paulo Henrique; Machado, Adriano Cosme de Oliveira; Kuga, Milton Carlos; Vivan, Rodrigo Ricci; Polleto, Raquel da Silva; Duarte, Marco Antonio Hungaro

    2012-01-01

    The aim of this study was to evaluate the interference of the radiopacifiers bismuth oxide (BO), bismuth carbonate (BC), bismuth subnitrate (BS), and zirconiun oxide (ZO) on the solubility, alkalinity and antimicrobial properties of white Portland cement (WPC). The substances were incorporated to PC, at a ratio of 1:4 (v/v) and subjected to a solubility test. To evaluate the pH, the cements were inserted into retrograde cavities prepared in simulated acrylic teeth and immediately immersed in deionized water. The pH of the solution was measured at 3, 24, 72 and 168 h. The antimicrobial activity was evaluated by a radial diffusion method against the microorganisms S. aureus (ATCC 25923), P. aeruginosa (ATCC 27853), E. faecalis (ATCC 29212) and C. albicans (ATCC 10231). The zone of microbial growth inhibition was measured after 24 h. The addition of BS and BC increased the solubility of the cement. The pH values demonstrated that all materials produced alkaline levels. At 3 h, BS showed lower pH than WPC (p0.05). The materials did not present antimicrobial activity for S. aureus, P. aeruginosas and E. faecalis (p>0.05). With regards to C. albicans, all materials formed an inhibition zone, mainly the mixture of WPC with ZO (p<0.05). The type of radiopacifier incorporated into WPC interfered with its physical and antimicrobial properties. ZO was found to be a viable radiopacifier that can be used with WPC.

  19. Effects of irradiation, antimicrobial agents and modified packaging on histamine production by Morganella morganii in mackerel fillets

    International Nuclear Information System (INIS)

    Aytac, S.A.; Ozbas, Z.Y.; Vural, H.

    2000-01-01

    The effects of gamma irradiation (0.5 and 2.0 kGy), antimicrobial agents (5% sodium chloride and 1% potassium sorbate) and modified atmosphere (100% CO2) packaging (MAP) on histamine production by Morganella morganii were examined in mackerel fillets during 8 days of cold storage. MAP combined with antimicrobial agents was also applied to the fillets. The changes in histamine levels, M. morganii and total aerobic bacterial counts were determined during the storage. All methods used in this study showed beneficial effect in controlling bacterial growth and histamine production on mackerel fillets during 2-3 days of storage. MAP combined with 5% sodium chloride has more retarding effect on production of histamine than the other methods. For M. morganii, maximum inhibition effect was found at the dose of 2.0 kGy. Irradiation with a dose of 2.0 kGy, MAP combined with sodium chloride and MAP were also found to have the most inhibiting effects on total aerobic bacterial count during the storage

  20. In vitro activity of five tetracyclines and some other antimicrobial agents against four porcine respiratory tract pathogens.

    Science.gov (United States)

    Pijpers, A; Van Klingeren, B; Schoevers, E J; Verheijden, J H; Van Miert, A S

    1989-09-01

    The minimal inhibitory concentrations (MIC) of five tetracyclines and ten other antimicrobial agents were determined for four porcine bacterial respiratory tract pathogens by the agar dilution method. For the following oxytetracycline-susceptible strains, the MIC50 ranges of the tetracyclines were: P. multocida (n = 17) 0.25-0.5 micrograms/ml; B. bronchiseptica (n = 20) 0.25-1.0 micrograms/ml; H. pleuropneumoniae (n = 20) 0.25-0.5 micrograms/ml; S. suis Type 2 (n = 20) 0.06-0.25 micrograms/ml. For 19 oxytetracycline-resistant P. multocida strains the MIC50 of the tetracyclines varied from 64 micrograms/ml for oxytetracycline to 0.5 micrograms/ml for minocycline. Strikingly, minocycline showed no cross-resistance with oxytetracycline, tetracycline, chlortetracycline and doxycycline in P. multocida and in H. pleuropneumoniae. Moreover, in susceptible strains minocycline showed the highest in vitro activity followed by doxycycline. Low MIC50 values were observed for chloramphenicol, ampicillin, flumequine, ofloxacin and ciprofloxacin against P. multocida and H. pleuropneumoniae. B. bronchiseptica was moderately susceptible or resistant to these compounds. As expected tiamulin, lincomycin, tylosin and spiramycin were not active against H. pleuropneumoniae. Except for flumequine, the MIC50 values of nine antimicrobial agents were low for S. suis Type 2. Six strains of this species showed resistance to the macrolides and lincomycin.

  1. Synthesis in plants and plant extracts of silver nanoparticles with potent antimicrobial properties: current status and future prospects.

    Science.gov (United States)

    Mashwani, Zia-ur-Rehman; Khan, Tariq; Khan, Mubarak Ali; Nadhman, Akhtar

    2015-12-01

    Synthesis of silver nanoparticles by plants and plant extracts (green synthesis) has been developed into an important innovative biotechnology, especially in the application of such particles in the control of pathogenic bacteria. This is a safer technology, biologically and environmentally, than synthesis of silver nanoparticles by chemical or physical methods. Plants are preferable to microbes as agents for the synthesis of silver nanoparticles because plants do not need to be maintained in cell culture. The antibacterial activity of bionanoparticles has been extensively explored during the past decade. This review examines studies published in the last decade that deal with the synthesis of silver nanoparticles in plants and their antibacterial activity.

  2. In vitro antimicrobial activity of plant extracts of Avicennia alba against some important pathogens

    Directory of Open Access Journals (Sweden)

    Varahalarao Vadlapudi

    2012-05-01

    Full Text Available Objective: In this present study antimicrobial activity of aerial parts of Avicennia alba were evaluated against the resistant pathogens belong to aquatic, human and plant origin. Methods: Soxhlet extraction method was used to get the corresponding extracts of hexane, chloroform and methanol. The antimicrobial activities of the organic solvent extracts on the various test microorganisms, including bacteria and fungi investigated using agar well diffusion technique. The length of inhibition zone was measured in millimeters from the edge of the well to the edge of the inhibition zone. Methanol and chloroform extracts exhibited promising antimicrobial activity than hexane extracts. Results: The zone of inhibition of chloroform varies from (9 to 17 mm where as with methanol (11 to 28 mm at 100 mg/ml concentration. Among all microorganisms studied Erwinia caratovara and Pseudomonas syringae showed the considerable growth inhibition with chloroform and methanolic extracts. Conclusions: A. alba can be used in the treatment of infectious diseases caused by resistant pathogenic microorganisms. Further studies are being carried out in order to separate the individual components that are present in plant extracts of A. alba using column chromatography.

  3. The in-vitro antimicrobial activities of some medicinal plants from Cameroon.

    Science.gov (United States)

    Gangoué-Piéboji, J; Pegnyemb, D E; Niyitegeka, D; Nsangou, A; Eze, N; Minyem, C; Mbing, J Ngo; Ngassam, P; Tih, R Ghogomu; Sodengam, B L; Bodo, B

    2006-04-01

    The antimicrobial activities of 10 plant species (Voacanga africana, Crepis cameroonica, Plagiostyles africana, Crotalaria retusa, Mammea africana, Lophira lanceolata, Ochna afzelii, Ouratea elongata, Ou. flava and Ou. sulcata), each of which is currently used in the traditional medicine of Cameroon, were investigated in vitro. The activities of a methanol extract of each plant were tested, in disc-diffusion assays, against 37 reference or laboratory strains of seven species of microorganism (Staphylococcus aureus, S. epidermidis, Enterococcus hirae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans). The minimal inhibitory concentrations of each extract were then estimated, against each of the more susceptible microorganisms (i.e. those giving an inhibition zone measuring at least 9 mm in diameter in the disc-diffusion assays), by agar dilution. Although, in the disc-diffusion assays, each of the 10 methanol extracts investigated displayed some degree of antimicrobial activity against at least one species of microorganism, no activity against the Gram-negative bacteria (Es. coli, K. pneumoniae and Ps. aeruginosa) was observed. The extract with the greatest antimicrobial activity was that of Pl. africana (Euphorbiaceae).

  4. Antimicrobial and antioxidant activities of Cortex Magnoliae Officinalis and some other medicinal plants commonly used in South-East Asia

    Directory of Open Access Journals (Sweden)

    Weng Wanyu

    2008-11-01

    Full Text Available Abstract 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.

  5. Antimicrobial and antioxidant activities of Cortex Magnoliae Officinalis and some other medicinal plants commonly used in South-East Asia

    Science.gov (United States)

    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

  6. Antimicrobial Effect of Escherichia Coli on Essential Oils Derived from Romanian Aromatic Plants

    Directory of Open Access Journals (Sweden)

    Şandru Daniela Maria

    2015-07-01

    Full Text Available This paper investigates the antimicrobial action of Escherichia coli ATCCR CRM-8739TM on the following essential oils: Teucrium marum, Pinus sylwestris, Thymus vulgaris, Salviae aethedaroleum, Cinnamomum aromaticum, Hippophae rhamnoides, Lavandula angustifolia, Abies alba, Zingiber officinale, Anethum graveolens, Coriandrum sativum, Origanum vulgare, extracted industrialy from romanian plants, using the diffusion disc method. The most intense activity was observed at the essential oil of Cinnamomum aromaticum (cinnamon and the mildest activity was observed at Zingiber officinale (ginger. Many of the essential oils tested exhibited moderate antimicrobial activity, as Teucrium marum, Thymus vulgaris, Hippophae rhamnoides, Lavandula angustifolia,Coriandrum sativum. The lowest antibacterial activity was exhibited on Pinus sylwestris, Salviae aethedaroleum, Zingiber officinale and Anethum graveolens.

  7. Plant-Derived Urease Inhibitors as Alternative Chemotherapeutic Agents.

    Science.gov (United States)

    Hassan, Sherif T S; Žemlička, Milan

    2016-07-01

    Inhibition of the metalloenzyme urease has important pharmacologic applications in the field of antiulcer and antigastric cancer agents. Urease is involved in many serious infections caused by Helicobacter pylori in the gastric tract as well as by Proteus and related species in the urinary tract. Although numerous studies have described several novel urease inhibitors (UIs) used for the treatment of gastric and urinary infections, all these compounds have exhibited severe side effects, toxicity, and instability. Therefore, to overcome such problems, it is necessary to search for new sources of UIs, such as natural products, that provide reduced side effects, low toxicity, greater stability, and bioavailability. As limited studies have been conducted on plant-derived UIs, this paper aims to highlight and summarize the most promising compounds isolated and identified from plants, such as terpenoids, phenolic compounds, alkaloids, and other substances with inhibitory activities against plant and bacterial ureases; these are in vitro and in vivo studies with an emphasis on structure-activity relationship studies and types of inhibition that show high and promising levels of anti-urease activity. This will aid medicinal chemists in the design and synthesis of novel and pharmacologically potent UIs useful for the development of antiulcer drugs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Synthesis, molecular modeling and structural characterization of vanillin derivatives as antimicrobial agents

    Science.gov (United States)

    Sun, Juan; Yin, Yong; Sheng, Gui-Hua; Yang, Zhi-Bo; Zhu, Hai-Liang

    2013-05-01

    Two vanillin derivatives have been designed and synthesized and their biological activities were also evaluated for antimicrobial activity. Their chemical structures are characterized by single crystal X-ray diffraction studies, 1H NMR, MS, and elemental analysis. Structural stabilization of them followed by intramolecular as well as intermolecular H-bonds makes these molecules as perfect examples in molecular recognition with self-complementary donor and acceptor units within a single molecule. Docking simulations have been performed to position compounds into the FtsZ active site to determine their probable binding model. Compound 3a shows the most potent biological activity, which may be a promising antimicrobial leading compound for the further research.

  9. Small cationic antimicrobial peptidomimetics: emerging candidate for the development of potential anti-infective agents.

    Science.gov (United States)

    Lohan, Sandeep; Bisht, Gopal Singh

    2013-01-01

    Rapid increase in the emergence and spread of microbes resistant to conventionally used antibiotics has become a major threat to global health care. Antimicrobial peptides (AMPs) are considered as a potential source of novel antibiotics because of their numerous advantages such as broad-spectrum activity, lower tendency to induce resistance, immunomodulatory response and unique mode of action. However, AMPs have several drawbacks such as; susceptibility to protease degradation, toxicity and high costs of manufacturing. Therefore, extensive research efforts are underway to explore the therapeutic potential of these fascinating natural compounds. This review highlights the potential of small cationic antimicrobial peptidomimetics (SCAMPs; M.W. ≅ 700 Da) as new generation antibiotics. In particular, we focused on recently identified small active pharmacophore from bulky templates of native AMPs, β-peptides, and lipopeptides. In addition, various design strategies recently undertaken to improve the physicochemical properties (proteolytic stability & plasma protein binding) of small cationic peptides have also been discussed.

  10. Indole diterpenoids from the endophytic fungus Drechmeria sp. as natural antimicrobial agents.

    Science.gov (United States)

    Zhao, Jian-Chao; Wang, Ya-Li; Zhang, Tian-Yuan; Chen, Zhong-Jian; Yang, Tian-Mei; Wu, Ying-Ying; Sun, Cheng-Peng; Ma, Xiao-Chi; Zhang, Yi-Xuan

    2018-04-01

    A fungal strain, Drechmeria sp., was isolated from the root of Panax notoginseng. Totally, seven new indole diterpenoids, drechmerins A-G (1-7), were isolated from the fermentation broth of Drechmeria sp. together with four known analogues (8-11). Their structures were determined on the basis of 1D and 2D NMR and electronic circular dichroism (ECD) spectroscopic analyses as well as theoretical calculations. All the isolated compounds were evaluated for their antimicrobial activities against Candida albicans, Staphylococcus aureus, Bacillus cereus, B. subtillis, Pseudomonas aeruginosa, and Klebsiella pneumonia, respectively. Drechmerin B (2) displayed antimicrobial activity against C. albicans with an MIC value of 12.5 μg/mL. Molecular docking was used to investigate interactions of peptide deformylase with compounds 1-3, 5-7, 9, and 10. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Antimicrobial and phyto chemical investigations of Veronia Amygdalina and other sudanese medicinal plants

    International Nuclear Information System (INIS)

    Almagboul, A.Z.; Bashir, A. K.; Salih, A. Karim M.; Khalid, S. A.; Farouk, A.

    1994-01-01

    Extracts of 111 Sudanese medicinal plants were subjected to preliminary antibacterial screening against four standard organisms (Bacillus subtilis, Stapylococcus aureus, Escherichia coli and pseudomonas aeruginasa). Out of the 573 extracts screened, 433 (70%) exhibited inhibitory activity against one ore more of the four tested bacteria. Most of the bioactive extracts (61%) showed inhibitory effects against the four organisms, while 11% were active against three, 20% against two and 8% against one organism. Based on the potent antibacterial activity and availability, eighteen plant species were selected and further extracted and subjected to antimicrobial investigation. About 38% of each of the methanolic and chloroformic extracts studied showed marked inhibitory effects against the tested organisms, where as the aqueous extracts exhibited less bioactivity (24%). None of these aqueous and methanolic extracts showed inhibitory against the two standard fungi tested (Aspergillus niger and candida albicans), while 97% of the chloroformic extracts exerted inhibitory effects against A. niger and 94% against C.albicans. On the basis of its prominent antimicrobial profiles against both bacteria and fungi tested, vernonia amygdalina was chosen as an appropriate candidate to pursue in depth phytochemical studies. the chloroformic extract which exhibited the most significant antimicrobial activity was subjected to bioactivity-directed fractionation. The bioactive fractions yielded two sesquiter-pene lactones, identified on the basis of their spectroscopical data (UV, IR, 1 H, NMR and mass spectroscopy) as vernodalin and vernolepin. Vernolepin has not been previously reported in this taxon, and it is the first time to publish the 13 C NMR of this compound. The present study established evidence of the potent antimicrobial activity of these two sesquiterpene lactones. The possible biogenetic pathway and structure/ activity relationships were discussed. (Author)

  12. Study of in vitro antimicrobial and antiproliferative activities of selected Saharan plants.

    Science.gov (United States)

    Palici, Ionut F; Liktor-Busa, Erika; Zupkó, István; Touzard, Blaise; Chaieb, Mohamed; Urbán, Edit; Hohmann, Judit

    2015-12-01

    The aim of the present study was the evaluation of the antimicrobial and antiproliferative activities of selected Saharan species, which are applied in the traditional medicine but not studied thoroughly from chemical and pharmacological point of view. The studied plants, namely Anthyllis henoniana, Centropodia forskalii, Cornulaca monacantha, Ephedra alata var. alenda, Euphorbia guyoniana, Helianthemum confertum, Henophyton deserti, Moltkiopsis ciliata and Spartidium saharae were collected from remote areas of North Africa, especially from the Tunisian region of Sahara. After drying and applying the appropriate extraction methods, the plant extracts were tested in antimicrobial screening assay, performed on 19 Gram-positive and -negative strains of microbes. The inhibition zones produced by plant extracts were determined by disc-diffusion method. Remarkable antibacterial activities were exhibited by extracts of Ephedra alata var. alenda and Helianthemum confertum against B. subtilis, M. catarrhalis and methicillin-resistant and non-resistant S. aureus. Minimum inhibitory concentrations of these two species were also determined. Antiproliferative effects of the extracts were evaluated against 4 human adherent cell lines (HeLa, A431, A2780 and MCF7). Notable cell growth inhibition was found for extract of Helianthemum confertum and Euphorbia guyoniana. Our results provided data for selection of some plant species for further detailed pharmacological and phytochemical examinations.

  13. Light insensitive silver(I) cyanoximates as antimicrobial agents for indwelling medical devices.

    Science.gov (United States)

    Gerasimchuk, Nikolay; Gamian, Andrzej; Glover, Garrett; Szponar, Bogumila

    2010-11-01

    Ten silver(I) cyanoximates of AgL composition (L = NC-C(NO)-R, where R is electron withdrawing groups: -CN, -C(O)NR(2), -C(O)R' (alkyl), -C(O)OEt, 2-heteroaryl fragments such as 2-pyridyl, 2-benzimidazolyl, 2-benzoxazolyl, 2-benzthiazolyl) were synthesized and characterized using spectroscopic methods and X-ray analysis. Crystal structures of four complexes were determined and revealed the formation of two-dimensional (2D) coordination polymers of different complexity in which anions exhibit bridging or combined chelate and bridging binding modes. In these compounds, anions are in the nitroso form. All studied AgL complexes are sparingly soluble in water and are thermally stable to 150 °C. Synthesized compounds demonstrated remarkable insensitivity toward visible light and UV-radiation, which was explained based on their polymeric structures with multiple covalent bonds between bridging cyanoxime ligands and Ag(I) centers. All 10 silver(I) cyanoximates were tested in vitro on the subject of their antimicrobial activity against both Gram-positive and Gram-negative microorganisms such as Escherichia coli, Klebsiella pneumoniae, Proteus sp., Pseudomonas aeruginosa, Enterococcus hirae, Streptococcus mutans, Staphylococcus aureus, and Mycobacterium fortuitum as well as against Candida albicans in solutions, and in the solid state as pressed pellets and dried filter paper disks presoaked with solutions of AgL in DMF. Results showed pronounced antimicrobial activity for all investigated complexes. A combination of five factors: (1) light insensitivity, (2) poor water solubility, (3) high thermal stability, (4) lack of toxicity of organic ligands, and (5) in vitro antimicrobial activity allows development of silver(I) cyanoximates for medical applications. These include antimicrobial additives to acrylate glue, cured by UV-radiation, used in introduction of prosthetic joints and dental implants, and prevention of biofilm formation on several types of indwelling medical

  14. Physicochemical investigations of biogenic chitosan-silver nanocomposite as antimicrobial and anticancer agent.

    Science.gov (United States)

    Arjunan, Nithya; Kumari, Henry Linda Jeeva; Singaravelu, Chandra Mohan; Kandasamy, Ruckmani; Kandasamy, Jothivenkatachalam

    2016-11-01

    Chitosan (CS), a seaweed polysaccharide is a natural macromolecule which is widely being used in medical applications because of its distinctive antimicrobial and anticancer properties. Silver, a noble metal, is also receiving wide attention for its potential usage in antimicrobial and anticancer therapeutics. In this study, an effective way of reduction of silver using chitosan at varying reaction temperatures and an optimised concentration of silver were performed. The optical, structural, spectral, morphological and elemental studies of the biosynthesized chitosan-silver (CS-Ag) nanocomposites were characterized by several techniques. The synthesized CS-Ag nanocomposites exhibit particle size around 20nm and were further exploited for potent biological applications in nanomedicine due to their nanometric sizes and biocompatibility of chitosan. The antimicrobial activity of the biosynthesized CS-Ag nanocomposites exhibits zone of inhibition ranged between 09.666±0.577 and 19.000±1.000 (mm). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were from 8 to 128μgmL -1 and 16 to 256μgmL -1 respectively, with the highest antimicrobial activity shown against Gram-negative Salmonella sp. The synergistic effect of chitosan and silver as a composite in nanometric size revealed significant IC 50 value of 29.35μgmL -1 and a maximum of 95.56% inhibition at 100μgmL -1 against A549 lung cancer cell line, resulting in potent anticancer effect. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. The Role Of Milk Peptide As Antimicrobial Agent In Supporting Health Status

    Directory of Open Access Journals (Sweden)

    Eni Kusumaningtyas

    2013-06-01

    Full Text Available Antimicrobial peptide is commonly present in all species as a component of their innate immune defense against infection. Antimicrobial peptides derived from milk such as isracidin, casocidin, casecidin and other fragments with variety of amino acid sequence are released upon enzymatic hydrolysis from milk protein К-casein, α-casein, β-casein, α-lactalbumin and β- lactoglobulin. These peptides were produced by the activity of digestive or microbial protease such as trypsin, pepsin, chymosin or alcalase. The mode of action of these peptides is by interaction of their positive with negative charge of target cell membrane leading to disruption of membrane associated with physiological event such as cell division or translocation of peptide across the membrane to interact with cytoplasmic target. Modification of charged or nonpolar aliphatic residues within peptides can enhance or reduce the activities of the peptides against a number of microbial strains and it seems to be strain dependent. Several peptides act not only as an antimicrobial but also as an angiotensin-converting enzyme inhibitor, antioxidant, immunomodulator, antiinflamation, food and feed preservative. Although the commercial production of these peptides is still limited due to lack of suitable large-scale technologies, fast development of some methods for peptide production will hopefully increase the possibility for mass production.

  16. Antimicrobial activity of camwood (Baphia nitida) dyes on common ...

    African Journals Online (AJOL)

    enoh

    2012-03-29

    Mar 29, 2012 ... on common human pathogens. O. K. Agwa*, C. I. ... and have antimicrobial properties (Egharevba and. Ikhatua, 2008). ... properties. Antibiotic susceptibility is used to determine the efficacy of these plants for use as antibiotics. The most basic laboratory measurement of the activity of an antimicrobial agent ...

  17. Influence of triclosan and triclocarban antimicrobial agents on the microbial activity in three physicochemically differing soils of south Australia

    Directory of Open Access Journals (Sweden)

    Abid Ali, Muhammad Arshad, Zahir A. Zahir

    2011-11-01

    Full Text Available Antimicrobial agents are being used in numerous consumer and health care products on account of which their annual global consumption has reached in millions of kilograms. They are flushed down the drain and become the part of wastewater and sewage sludge and end up in the ultimate sink of agricultural soils. Once they are in the soil, they may disturb the soil’s ecology as a result of which microbial activity useful for soil fertility and biodegradation of xenobiotics may severely be impacted. The present study was designed to assess the influence of two antimicrobial agents triclosan (TCS and triclocarban (TCC, commonly used in consumer and health care products, on the microbial activity in the three agricultural soils from South Australia having different characteristics. The study was laid out following the two factors factorial design by applying 14C-glucose at 5 µg g-1 with either TCS at 0, 30, 90 and 270 µg g-1 or TCC at 0, 50, 150 and 450 µg g-1 in three agricultural soils, Freeling (Typic Rhodoxeralf–sodic, Booleroo (Typic Rhodoxeralf and Avon (Calcixerralic Xerochrepts. The 14CO2, which was released as a result of microbial respiration, was trapped in 3 mL 1M NaOH and was quantified on Wallac WinSpectral α/β 1414 Liquid Scintillation Counter. The results revealed a significant difference in amounts of 14C-glucose mineralized in the three soils. A significant concentration dependant suppressive effect of TCS on the biomineralization of 14C-glucose appeared in all the tested soils as opposed to TCC where no such concentration dependent effect could be recorded. The reduction in 14C-glucose biomineralization in the Freeling, Booleroo and Avon soils was recorded up to 53.6, 38.5 and 37.4 % by TCS at 270 µg g-1 and 13.0, 5.8 and 1.6 % by TCC at 450 µg g-1 respectively. However, a significant negative correlation of CEC and pH was recorded with TCS and TCC effects. These results may imply that presence of such antimicrobial agents

  18. Preparation and Characterization of Antibacterial Polypropylene Meshes with Covalently Incorporated β-Cyclodextrins and Captured Antimicrobial Agent for Hernia Repair

    Directory of Open Access Journals (Sweden)

    Noor Sanbhal

    2018-01-01

    Full Text Available Polypropylene (PP light weight meshes are commonly used as hernioplasty implants. Nevertheless, the growth of bacteria within textile knitted mesh intersections can occur after surgical mesh implantation, causing infections. Thus, bacterial reproduction has to be stopped in the very early stage of mesh implantation. Herein, novel antimicrobial PP meshes grafted with β-CD and complexes with triclosan were prepared for mesh infection prevention. Initially, PP mesh surfaces were functionalized with suitable cold oxygen plasma. Then, hexamethylene diisocyanate (HDI was successfully grafted on the plasma-activated PP surfaces. Afterwards, β-CD was connected with the already HDI reacted PP meshes and triclosan, serving as a model antimicrobial agent, was loaded into the cyclodextrin (CD cavity for desired antibacterial functions. The hydrophobic interior and hydrophilic exterior of β-CD are well suited to form complexes with hydrophobic host guest molecules. Thus, the prepared PP mesh samples, CD-TCL-2 and CD-TCL-6 demonstrated excellent antibacterial properties against Staphylococcus aureus and Escherichia coli that were sustained up to 11 and 13 days, respectively. The surfaces of chemically modified PP meshes showed dramatically reduced water contact angles. Moreover, X-ray diffractometer (XRD, differential scanning calorimeter (DSC, and Thermogravimetric (TGA evidenced that there was no significant effect of grafted hexamethylene diisocyanate (HDI and CD on the structural and thermal properties of the PP meshes.

  19. Evaluation of antimicrobial activity of glycerol monolaurate nanocapsules against American foulbrood disease agent and toxicity on bees.

    Science.gov (United States)

    Lopes, Leonardo Q S; Santos, Cayane G; de Almeida Vaucher, Rodrigo; Gende, Liesel; Raffin, Renata P; Santos, Roberto C V

    2016-08-01

    The American Foulbrood Disease (AFB) is a fatal larval bee infection. The etiologic agent is the bacterium Paenibacillus larvae. The treatment involves incineration of all contaminated materials, leading to high losses. The Glycerol Monolaurate (GML) is a known antimicrobial potential compound, however its use is reduced due to its low solubility in water and high melting point. The nanoencapsulation of some drugs offers several advantages like improved stability and solubility in water. The present study aimed to evaluate the antimicrobial activity against P. larvae and the toxicity in bees of GML nanoparticles. The nanocapsules were produced and presented mean diameter of 210 nm, polydispersity index of 0.044, and zeta potential of -23.4 mV demonstrating the acceptable values to predict a stable system. The microdilution assay showed that it is necessary 142 and 285 μg/mL of GML nanocapsules to obtain a bacteriostatic and bactericidal effect respectively. The time-kill curve showed the controlled release of compound, exterminating the microorganism after 24 h. The GML nanocapsules were able to kill the spore form of Paenibacillus larvae while the GML do not cause any effect. The assay in bees showed that the GML has a high toxicity while the GML nanoparticles showed a decrease on toxic effects. Concluding, the formulation shows positive results in the action to combat AFB besides not causing damage to bees. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Reduced Susceptibility to Rifampicin and Resistance to Multiple Antimicrobial Agents among Brucella abortus Isolates from Cattle in Brazil.

    Science.gov (United States)

    Barbosa Pauletti, Rebeca; Reinato Stynen, Ana Paula; Pinto da Silva Mol, Juliana; Seles Dorneles, Elaine Maria; Alves, Telma Maria; de Sousa Moura Souto, Monalisa; Minharro, Silvia; Heinemann, Marcos Bryan; Lage, Andrey Pereira

    2015-01-01

    This study aimed to determine the susceptibility profile of Brazilian Brucella abortus isolates from cattle to eight antimicrobial agents that are recommended for the treatment of human brucellosis and to correlate the susceptibility patterns with origin, biotype and MLVA16-genotype of the strains. Screening of 147 B. abortus strains showed 100% sensitivity to doxycycline and ofloxacin, one (0.68%) strain resistant to ciprofloxacin, two strains (1.36%) resistant to streptomycin, two strains (1.36%) resistant to trimethoprim-sulfamethoxazole and five strains (3.40%) resistant to gentamicin. For rifampicin, three strains (2.04%) were resistant and 54 strains (36.73%) showed reduced sensitivity. Two strains were considered multidrug resistant. In conclusion, the majority of B. abortus strains isolated from cattle in Brazil were sensitive to the antimicrobials commonly used for the treatment of human brucellosis; however, a considerable proportion of strains showed reduced susceptibility to rifampicin and two strains were considered multidrug resistant. Moreover, there was no correlation among the drug susceptibility pattern, origin, biotype and MLVA16-genotypes of these strains.

  1. Synthesis, spectroscopic characterization and computational chemical study of 5-cyano-2-thiouracil derivatives as potential antimicrobial agents

    Science.gov (United States)

    Rizk, Sameh A.; El-Naggar, Abeer M.; El-Badawy, Azza A.

    2018-03-01

    A series of 5-cyano-2-thiouracil derivatives, containing diverse hydrophobic groups in the 2-, 4- and 6-positions, were synthesized through one pot reaction of thiophene 2-carboxaldehyde, ethylcyanoacetate and thiourea using classic reflux-based method as well as microwave-assisted methods. Such prepared compounds were reacted with different electrophilic reagents to synthesize potent anti-microbial agents, e.g. 1,3,4-thiadiazinopyrimidine, hydrazide and triazolopyrimidine derivatives (compounds 4a-e, 9 and 10-12) respectively. The density functional theory (DFT) was then applied to explore the structural and electronic characteristics of these materials. It is found that compound 12 exhibited the highest antibacterial and antifungal activity against C. Albicans showing six-fold increasing biological affinity compared to that of Colitrimazole drug with MIC values 7.8 and 49 μg/mL, respectively. All the synthesized compounds have been characterized based on their elemental analyses and spectral data. Such compounds can be submitted to in vivo antimicrobial studies in future works.

  2. Plant flavones enhance antimicrobial activity of respiratory epithelial cell secretions against Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Benjamin M Hariri

    Full Text Available Flavones are a class of natural plant secondary metabolites that have anti-inflammatory and anti-bacterial effects. Some flavones also activate the T2R14 bitter taste receptor, which is expressed in motile cilia of the sinonasal epithelium and activates innate immune nitric oxide (NO production. Flavones may thus be potential therapeutics for respiratory infections. Our objective was to examine the anti-microbial effects of flavones on the common sinonasal pathogens Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa, evaluating both planktonic and biofilm growth. Flavones had only very low-level antibacterial activity alone. They did not reduce biofilm formation, but did reduce production of the important P. aeruginosa inflammatory mediator and ciliotoxin pyocyanin. However, flavones exhibited synergy against P. aeruginosa in the presence of antibiotics or recombinant human lysozyme. They also enhanced the efficacy of antimicrobials secreted by cultured and primary human airway cells grown at air-liquid interface. This suggests that flavones may have anti-gram-negative potential as topical therapeutics when combined with antibiotics or in the context of innate antimicrobials secreted by the respiratory or other epithelia. This may have an additive effect when combined with T2R14-activated NO production. Additional studies are necessary to understand which flavone compounds or mixtures are the most efficacious.

  3. Chemical Composition and Antimicrobial Activities of Essential Oils of Some Coniferous Plants Cultivated in Egypt.

    Science.gov (United States)

    Ibrahim, Taghreed A; El-Hela, Atef A; El-Hefnawy, Hala M; Al-Taweel, Areej M; Perveen, Shagufta

    2017-01-01

    Family Cupressaceae is the largest coniferous plant family. Essential oils of many species belonging to family Cupressaceae are known to have several biological activities specially antimicrobial activity. The essential oils from aerial parts of Calocedrus decurrens Torr., Cupressus sempervirens stricta L. and Tetraclinis articulata (Vahl) Mast. were prepared by hydrodistillation. The chemical composition of the essential oils has been elucidated by gas chromatography-mass spectroscopy analysis. The prepared essential oils were examined against selected species of Gram-positive, Gram-negative bacteria and Candida species. Broth dilution methods were used to detect minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC). Sixteen compounds were identified in the essential oils of both Calocedrus decurrens and Cupressus sempervirens L. and fifteen compounds were identified in the essential oil of Tetraclinis articulata . δ-3-Carene (43.10%), (+)-Cedrol (74.03%) and Camphor (21.23%) were the major constituents in the essential oils of Calocedrus decurrens , Cupressus sempervirens L. and Tetraclinis articulata , respectively. The essential oils showed strong antimicrobial activities against the selected microorganisms in concentration range 0.02 3- 3.03 µL/mL. This study could contribute to the chemotaxonomic characterization of family Cupressaceae. In addition, it proved that the essential oils under investigation possess potential antimicrobial properties.

  4. Analysis of Antimicrobial and Antioxidant Activities of Chenopodium ambrosioides: An Ethnomedicinal Plant

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    Muhammad Ajaib

    2016-01-01

    Full Text Available The antimicrobial and antioxidant potential of Chenopodium ambrosioides L. was explored. Antimicrobial potential was investigated through zone of inhibition and minimum inhibition concentration whereas antioxidant potential of selected plant was evaluated through different techniques, that is, total phenolic contents, total flavonoids content, DPPH assay, ABTS assay, and metal chelating. It is concluded that both parts showed good to satisfactory antimicrobial and antioxidant results. The maximum antibacterial potential is exhibited by bark macerated in petroleum ether against Bacillus subtilis (33±1.5 mm and maximum antifungal potential exhibited by methanol extracts of fruit against Aspergillus niger (16±1.5 mm. Aqueous extracts failed to show any activity against selected organisms. The minimum (significant MIC value exhibited by fruit extract against Staphylococcus aureus was 0.009±0.02 at 0.7 mg/mL. Aqueous extracts of bark and fruit exhibited maximum antioxidant potential in all assays except DPPH assay. Petroleum ether bark extract showed maximum % DPPH value.

  5. Efficacy of anti-microbial agents on vaginal microorganisms and reproductive performance of synchronized estrus ewes

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    Mohammed KM

    2017-05-01

    Full Text Available Objective: To isolate and identify microflora and fungal species at different phases during estrus synchronization of ewes and estimate their prevalence; compare the effectiveness of antimicrobial administration to intravaginal sponge on the changes in the vaginal microorganisms and reproductive performance. Methods: Sixty Egyptian ewes were allocated into three equal groups (G: 1, 2 and 3. G1 was inserted with vaginal sponge containing medroxyprogesterone acetate and served as control; without antimicrobial additive. The other two groups were treated as G1, but sponges were previously injected with ciprofloxacin (G2, while sponges of G3 were injected with ciprofloxacin and clotrimazole. Vaginal swabs were collected from each treated ewe, prior sponge insertion, at sponge withdrawal and 48 h later for microbiological investigation and bacterial count. On the day of sponge removal, 300 IU/eCG was administered for each treated ewe. The identified bacterial strains before sponge insertion were tested for sensitivity with antimicrobial disks. Results: Bacterial isolates before sponge insertion were more sensitive to ciprofloxacin. Frequencies of ewes in estrus; the interval from sponge withdrawal to onset estrus and the duration of estrus were statistically similar among treated groups. The pregnancy rate in G2 (100.0% was higher than G1 (66.7% and G3 (82.4%. The total bacterial count before sponge insertion was similar between all treatments and increased significantly in all groups on the day of sponge withdraw. The prevailing bacteria on D0, D14 and 48 h after sponge removal for all treated groups were Staphylococcus spp. followed by Escherichia coli. Regarding to fungus species, percentages of isolation increased from 5.00% (before sponge insertion to 100.00% and 88.89% at sponge withdraw for G1 and G2, respectively. In G3, the fungus was declined from 10% (before sponge insertion to 5% (at sponge removal. Conclusions: The concomitant treatments

  6. Efficacy of anti-microbial agents on vaginal microorganisms and reproductive performance of synchronized estrus ewes

    Directory of Open Access Journals (Sweden)

    K M Mohammed

    2017-01-01

    Full Text Available Objective: To isolate and identify microflora and fungal species at different phases during estrus synchronization of ewes and estimate their prevalence; compare the effectiveness of antimicrobial administration to intravaginal sponge on the changes in the vaginal microorganisms and reproductive performance.Methods: Sixty Egyptian ewes were allocated into three equal groups (G: 1, 2 and 3. G1 was inserted with vaginal sponge containing medroxy- progesterone acetate and served as control; without antimicrobial additive. The other two groups were treated as G1, but sponges were previously injected with ciprofloxacin (G2, while sponges of G3 were injected with ciprofloxacin and clotrimazole. Vaginal swabs were collected from each treated ewe, prior sponge insertion, at sponge withdrawal and 48 h later for microbiological investigation and bacterial count. On the day of sponge removal, 300 IU/eCG was administered for each treated ewe. The identified bacterial strains before sponge insertion were tested for sensitivity with antimicrobial disks.Results: Bacterial isolates before sponge insertion were more sensitive to ciprofloxacin. Frequencies of ewes in estrus; the interval from sponge withdrawal to onset estrus and the duration of estrus were statistically similar among treated groups. The pregnancy rate in G2 (100.0% was higher than G1 (66.7% and G3 (82.4%. The total bacterial count before sponge insertion was similar between all treatments and increased significantly in all groups on the day of sponge withdraw. The prevailing bacteria on D0, D14 and 48 h after sponge removal for all treated groups were Staphylococcus spp. followed by Escherichia coli. Regarding to fungus species, percentages of isolation increased from 5.00% (before sponge insertion to 100.00% and 88.89% at sponge withdraw for G1 and G2, respectively. In G3, the fungus was declined from 10% (before sponge insertion to 5% (at sponge removal.Conclusions: The concomitant treatments

  7. In Vitro Synergism between Azithromycin or Terbinafine and Topical Antimicrobial Agents against Pythium insidiosum

    Science.gov (United States)

    Itaqui, Sabrina R.; Verdi, Camila M.; Tondolo, Juliana S. M.; da Luz, Thaisa S.; Alves, Sydney H.; Santurio, Janio M.

    2016-01-01

    We describe here in vitro activity for the combination of azithromycin or terbinafine and benzalkonium, cetrimide, cetylpyridinium, mupirocin, triclosan, or potassium permanganate. With the exception of potassium permanganate, the remaining antimicrobial drugs were active and had an MIC90 between 2 and 32 μg∕ml. The greatest synergism was observed for the combination of terbinafine and cetrimide (71.4%). In vivo experimental evaluations will clarify the potential of these drugs for the topical treatment of lesions caused by Pythium insidiosum. PMID:27216049

  8. Development of membranes of PLGA functionalized with antimicrobial agents nanostructured; Desenvolvimento de membranas de PLGA funcionalizadas com agentes antimicrobianos nanoestruturados

    Energy Technology Data Exchange (ETDEWEB)

    Souza, S.G.; Molin, M.L.A.L.; Nogueira, A.L.; Schneider, E. Duek; Pezzin, A.P.T., E-mail: suelengdesouza@gmail.com [Universidade da Regiao de Joinville (UNIVILLE), SC (Brazil)

    2016-07-01

    Periodontitis is a disease affecting the tooth supporting tissues, causing loss of bone attachment. One of the possible treatments is through guided tissue regeneration (GTR). Currently, a variety of resorbable membranes are available as alternative to conventional non-resorbable membranes for this application, as the membranes of poly (lactic acid-co-glycolic acid) (PLGA). In this context, this study aimed to produce membranes were biocompatible and nanostructured functionalized with antibacterial agents and evaluate its thermal properties for future application in RTG. For the production of membranes were used as the PLGA polymer matrix. The NpAg were used at concentrations of 5, 7, 8 and 10 ppm and NpZnO were: 10, 50, 100 and 150 ppm. The materials were characterized by TGA and DSC. (author)

  9. Biodegradable gelatin-chitosan films incorporated with essential oils as antimicrobial agents for fish preservation.

    Science.gov (United States)

    Gómez-Estaca, J; López de Lacey, A; López-Caballero, M E; Gómez-Guillén, M C; Montero, P

    2010-10-01

    Essential oils of clove (Syzygium aromaticum L.), fennel (Foeniculum vulgare Miller), cypress (Cupressus sempervirens L.), lavender (Lavandula angustifolia), thyme (Thymus vulgaris L.), herb-of-the-cross (Verbena officinalis L.), pine (Pinus sylvestris) and rosemary (Rosmarinus officinalis) were tested for their antimicrobial activity on 18 genera of bacteria, which included some important food pathogen and spoilage bacteria. Clove essential oil showed the highest inhibitory effect, followed by rosemary and lavender. In an attempt to evaluate the usefulness of these essential oils as food preservatives, they were also tested on an extract made of fish, where clove and thyme essential oils were the most effective. Then, gelatin-chitosan-based edible films incorporated with clove essential oil were elaborated and their antimicrobial activity tested against six selected microorganisms: Pseudomonas fluorescens, Shewanella putrefaciens, Photobacterium phosphoreum, Listeria innocua, Escherichia coli and Lactobacillus acidophilus. The clove-containing films inhibited all these microorganisms irrespectively of the film matrix or type of microorganism. In a further experiment, when the complex gelatin-chitosan film incorporating clove essential oil was applied to fish during chilled storage, the growth of microorganisms was drastically reduced in gram-negative bacteria, especially enterobacteria, while lactic acid bacteria remained practically constant for much of the storage period. The effect on the microorganisms during this period was in accordance with biochemical indexes of quality, indicating the viability of these films for fish preservation. 2010 Elsevier Ltd. All rights reserved.

  10. Frequency of resistance in obligate anaerobic bacteria isolated from dogs, cats, and horses to antimicrobial agents.

    Science.gov (United States)

    Lawhon, S D; Taylor, A; Fajt, V R

    2013-11-01

    Clinical specimens from dogs, cats, and horses were examined for the presence of obligate anaerobic bacteria. Of 4,018 specimens cultured, 368 yielded 606 isolates of obligate anaerobic bacteria (248 from dogs, 50 from cats, and 308 from horses). There were 100 specimens from 94 animals from which only anaerobes were isolated (25 dogs, 8 cats, and 61 horses). The most common sites tested were abdominal fluid (dogs and cats) and intestinal contents (horses). The most common microorganism isolated from dogs, cats, and horses was Clostridium perfringens (75, 13, and101 isolates, respectively). The MICs of amoxicillin with clavulanate, ampicillin, chloramphenicol, metronidazole, and penicillin were determined using a gradient endpoint method for anaerobes. Isolates collected at necropsy were not tested for antimicrobial susceptibility unless so requested by the clinician. There were 1/145 isolates tested that were resistant to amoxicillin-clavulanate (resistance breakpoint ≥ 16/8 μg/ml), 7/77 isolates tested were resistant to ampicillin (resistance breakpoint ≥ 2 μg/ml), 4/242 isolates tested were resistant to chloramphenicol (resistance breakpoint ≥ 32 μg/ml), 12/158 isolates tested were resistant to clindamycin (resistance breakpoint ≥ 8 μg/ml), 10/247 isolates tested were resistant to metronidazole (resistance breakpoint ≥ 32 μg/ml), and 54/243 isolates tested were resistant to penicillin (resistance breakpoint ≥ 2 μg/ml). These data suggest that anaerobes are generally susceptible to antimicrobial drugs in vitro.

  11. Design of Novel 4-Hydroxy-chromene-2-one Derivatives as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Milan Mladenović

    2010-06-01

    Full Text Available This paper presents the design of novel 4-hydroxy-chromene-2 one derivatives, based on previously obtained minimal inhibitory concentration values (MICs, against twenty four microorganism cultures, Gram positive and negative bacteria and fungi. Two of our compounds, 3b (MIC range 130–500 μg/mL and 9c (31.25–62.5 μg/mL, presented high potential antimicrobial activity. The compound 9c had equal activity to the standard ketoconazole (31.25 μg/mL against M. mucedo. Enlarged resistance of S. aureus, E. coli and C. albicans on the effect of potential drugs and known toxicity of coumarin antibiotics, motivated us to establish SAR and QSAR models of activity against these cultures and correlate biological activity, molecular descriptors and partial charges of functional groups to explain activity and use for the design of new compounds. The QSAR study presents essential relation of antimicrobial activity and dominant substituents, 4-hydroxy, 3-acetyl and thiazole functional groups, also confirmed through molecular docking. The result was ten new designed compounds with much improved predicted inhibition constants and average biological activity.

  12. New Biofunctional Loading of Natural Antimicrobial Agent in Biodegradable Polymeric Films for Biomedical Applications

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    Bakhtawar Ghafoor

    2016-01-01

    Full Text Available The study focuses on the development of novel Aloe vera based polymeric composite films and antimicrobial suture coatings. Polyvinyl alcohol (PVA, a synthetic biocompatible and biodegradable polymer, was combined with Aloe vera, a natural herb used for soothing burning effects and cosmetic purposes. The properties of these two materials were combined together to get additional benefits such as wound healing and prevention of surgical site infections. PVA and Aloe vera were mixed in a fixed quantity to produce polymer based films. The films were screened for antibacterial and antifungal activity against bacterial (E. coli, P. aeruginosa and fungal strains (Aspergillus flavus and Aspergillus tubingensis screened. Aloe vera based PVA films showed antimicrobial activity against all the strains; the lowest Aloe vera concentration (5% showed the highest activity against all the strains. In vitro degradation and release profile of these films was also evaluated. The coating for sutures was prepared, in vitro antibacterial tests of these coated sutures were carried out, and later on in vivo studies of these coated sutures were also performed. The results showed that sutures coated with Aloe vera/PVA coating solution have antibacterial effects and thus have the potential to be used in the prevention of surgical site infections and Aloe vera/PVA based films have the potential to be used for wound healing purposes.

  13. Antimicrobial Peptides (AMPs

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    Mehrzad Sadredinamin

    2016-04-01

    Full Text Available Antimicrobial peptides (AMPs are extensive group of molecules that produced by variety tissues of invertebrate, plants, and animal species which play an important role in their immunity response. AMPs have different classifications such as; biosynthetic machines, biological sources, biological functions, molecular properties, covalent bonding patterns, three dimensional structures, and molecular targets.These molecules have multidimensional properties including antimicrobial activity, antiviral activity, antifungal activity, anti-parasite activity, biofilm control, antitumor activity, mitogens activity and linking innate to adaptive immunity that making them promising agents for therapeutic drugs. In spite of this advantage of AMPs, their clinical developments have some limitation for commercial development. But some of AMPs are under clinical trials for the therapeutic purpose such as diabetic foot ulcers, different bacterial infections and tissue damage. In this review, we emphasized on the source, structure, multidimensional properties, limitation and therapeutic applications of various antimicrobial peptides.

  14. Vancomycin-modified Fe3O4@SiO2@Ag microflowers as effective antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Wang C

    2017-04-01

    Full Text Available Chongwen Wang,1,2,* Kehan Zhang,2,* Zhe Zhou,2,* Qingjun Li,2 Liting Shao,2 Rong Zhang Hao,3 Rui Xiao,2 Shengqi Wang1,2 1College of Life Sciences & Bio-Engineering, Beijing University of Technology, 2Beijing Key Laboratory of New Molecular Diagnosis Technologies for Infectious Diseases, Beijing Institute of Radiation Medicine, Beijing, 3Institute for Disease Control and Prevention, Academy of Military Medical Sciences, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Nanomaterials combined with antibiotics exhibit synergistic effects and have gained increasing interest as promising antimicrobial agents. In this study, vancomycin-modified magnetic-based silver microflowers (Van/Fe3O4@SiO2@Ag microflowers were rationally designed and prepared to achieve strong bactericidal ability, a wide antimicrobial spectrum, and good recyclability. High-performance Fe3O4@SiO2@Ag microflowers served as a multifunction-supporting matrix and exhibited sufficient magnetic response property due to their 200 nm Fe3O4 core. The microflowers also possessed a highly branched flower-like Ag shell that provided a large surface area for effective Ag ion release and bacterial contact. The modified-vancomycin layer was effectively bound to the cell wall of bacteria to increase the permeability of the cell membrane and facilitate the entry of the Ag ions into the bacterium, resulting in cell death. As such, the fabricated Van/Fe3O4@SiO2@Ag microflowers were predicted to be an effective and environment-friendly antibacterial agent. This hypothesis was verified through sterilization of Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus, with minimum inhibitory concentrations of 10 and 20 µg mL-1, respectively. The microflowers also showed enhanced effect compared with bare Fe3O4@SiO2@Ag microflowers and free-form vancomycin, confirming the synergistic effects of the combination of the

  15. In vitro evaluation of the effects of some plant essential oils on Ascosphaera apis, the causative agent of Chalkbrood disease

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    Mohammad Javed Ansari

    2017-07-01

    Full Text Available Ascosphaera apis is one of the major fungal pathogens of honey bee broods and the causative agent of Chalkbrood disease. The factors responsible for the pathogenesis of Chalkbrood disease are still not fully understood, and the increasing resistance of A. apis to commonly used antifungal agents necessitates a search for new agents to control this disease. The in vitro antifungal activities of 27 plant essential oils against two isolates of A. apis (Aksu-4 and Aksu-9 were evaluated. Out of the 27 plant essential oils tested, 21 were found to be effective in killing both isolates of A. apis. Based on their minimum fungicidal concentration (MFC values, the effective oils were grouped into three categories: highly effective, moderately effective and minimally effective. Mountain pepper oil, Kala Bhangra oil, spearmint oil, babuna oil, betel leaf oil, carrot seed oil, cumin seed oil and clove bud oil were highly effective, with MBC values between 50.0 μg/mL and 600.0 μg/mL. Mountain pepper was the most effective essential oil, with an MBC value of 50.0 μg/mL. Citral and caryophyllene containing oils were the most effective with MIC 50 ppm. The essential oils tested exhibited significant antimicrobial activities against both strains of A. apis, and they may contain compounds that could play an important role in the treatment or prevention of Chalkbrood disease of honeybee.

  16. Production of phytotoxic cationic α-helical antimicrobial peptides in plant cells using inducible promoters.

    Directory of Open Access Journals (Sweden)

    Nuri Company

    Full Text Available Synthetic linear antimicrobial peptides with cationic α-helical structures, such as BP100, have potent and specific activities against economically important plant pathogenic bacteria. They are also recognized as valuable therapeutics and preservatives. However, highly active BP100 derivatives are often phytotoxic when expressed at high levels as recombinant peptides in plants. Here we demonstrate that production of recombinant phytotoxic peptides in transgenic plants is possible by strictly limiting transgene expression to certain tissues and conditions, and specifically that minimization of this expression during transformation and regeneration of transgenic plants is essential to obtain viable plant biofactories. On the basis of whole-genome transcriptomic data available online, we identified the Os.hsp82 promoter that fulfilled this requirement and was highly induced in response to heat shock. Using this strategy, we generated transgenic rice lines producing moderate yields of severely phytotoxic BP100 derivatives on exposure to high temperature. In addition, a threshold for gene expression in selected tissues and stages was experimentally established, below which the corresponding promoters should be suitable for driving the expression of recombinant phytotoxic proteins in genetically modified plants. In view of the growing transcriptomics data available, this approach is of interest to assist promoter selection for specific purposes.

  17. Biocompatibility index of antiseptic agents by parallel assessment of antimicrobial activity and cellular cytotoxicity.

    Science.gov (United States)

    Müller, Gerald; Kramer, Axel

    2008-06-01

    To assess the suitability of an antiseptic agent, both the microbicidal activity and the cytotoxic effect must be taken into consideration to derive biocompatible antibacterial agents. We defined the biocompatibility index (BI) by measuring the antibacterial activity against the test organisms Escherichia coli and Staphylococcus aureus and, in parallel, the cytotoxicity on cultured murine fibroblasts. The antiseptic agents tested were benzalkonium chloride (BAC), cetylpyridinium chloride (CPC), chlorhexidine digluconate (CHX), mild silver protein (MSP), octenidine dihydrochloride (OCT), polyhexamethylene biguanide (PHMB), povidone iodine in solution [PVP-I(s)], povidone iodine in ointment [PVP-I(o)], silver nitrate (AgNO(3)), silver (I) sulfadiazine (SSD) and triclosan (TRI). Assays were carried out for 30 min of exposure at 37 degrees C in the presence of cell culture medium containing 10% fetal bovine serum. The resulting dimensionless BI was defined as the ratio of the concentration at which 50% of the murine fibroblasts are damaged and the microbicidal effect producing at least 3 log(10) (99.9%) reduction. The resulting rank ordering of BI for the ratio of fibroblast cytotoxicity to E. coli toxicity was OCT > PHMB > CHX > PVP-I(o) > PVP-I(s) > BAC > CPC > TRI > MSP and that to S. aureus was OCT > PHMB > CHX > CPC > PVP-I(o) > BAC > PVP(s) > TRI > MSP. OCT and PHMB were the most suitable agents with a BI greater than 1. The BI presented may be a useful tool to evaluate antiseptic agents for use in clinical practice.

  18. ANTIMICROBIAL ACTIVITY OF THE SUBSTANCES RECEIVED FROM RAW MATERIALS OF BIRCH FAMILY PLANTS

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    Fedchenkova Yu.A

    2016-12-01

    Full Text Available Introduction. In accordance with the last events in Ukraine (considering military operations in anti-terrorist operation in the Luhansk and Donetsk regions the domestic medicine is in great need in preparations with antimicrobial activity. Our attention as the sources of receiving biologically active substances with antimicrobial activity was drawn with birch Betulaceae family plants – hazel ordinary Corylus avellana L. and black alder Alnus glutinosa (L. Gaertn. It is known that in medicine the leaves of hazel ordinary are used as antiseptic, anti-inflammatory, vesselrestorative drug, and the leaves of black alder reveal the antiinflammatory, astringent, wound healing, spasmolytic and choleretic action. However, the drugs with antimicrobial action received from the leaves of these plants are absent on the market of Ukraine. Therefore the studying of antimicrobial activity of this type of raw materials received from hazel ordinary and black alder, for creation of new medicines, is now one of the main directions in pharmacy. For this purpose we have revealed tinctures, spirit, lipophilic and polysacharid fractions received from the leaves of hazel ordinary and black alder. The purpose of our research is studying of antimicrobial activity of revealed substance received from the leaves of black alder and hazel ordinary. Materials and methods. There were being examined tinctures, lipophilic, spirit and polysacharid fractions received from the leaves of hazel ordinary and black alder. The test of antimicrobial effect of substances was carried out by means of serial dilution concerning the following six reference cultures: Staphylococcus aureus ATCC 6538-P, Candida albicans ATCC 885-653, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6833, Bacillus cereus ATCC 10702, Pseudomonas aeruginosa ATCC 9027, according to the State Pharmacopoeia of Ukraine, in the Department of Microbiology and Immunology of KMAPE. For the experiment there was prepared

  19. Motuporamine Derivatives as Antimicrobial Agents and Antibiotic Enhancers against Resistant Gram-Negative Bacteria.

    Science.gov (United States)

    Borselli, Diane; Blanchet, Marine; Bolla, Jean-Michel; Muth, Aaron; Skruber, Kristen; Phanstiel, Otto; Brunel, Jean Michel

    2017-02-01

    Dihydromotuporamine C and its derivatives were evaluated for their in vitro antimicrobial activities and antibiotic enhancement properties against Gram-negative bacteria and clinical isolates. The mechanism of action of one of these derivatives, MOTU-N44, was investigated against Enterobacter aerogenes by using fluorescent dyes to evaluate outer-membrane depolarization and permeabilization. Its efficiency correlated with inhibition of dye transport, thus suggesting that these molecules inhibit drug transporters by de-energization of the efflux pump rather than by direct interaction of the molecule with the pump. This suggests that depowering the efflux pump provides another strategy to address antibiotic resistance. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  20. Potential of the Essential Oil from Pimenta Pseudocaryophyllus as an Antimicrobial Agent

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    Suzuki Érika Yoko

    2014-09-01

    Full Text Available This study evaluated the effectiveness of the essential oil of Pimenta pseudocaryophyllus in inhibiting the growth of the main bacteria responsible for bad perspiration odor (Staphylococcus epidermidis, Proteus hauseri, Micrococcus yunnanensis and Corynebacterium xerosis. The chemical profile of the essential oil was evaluated by high-resolution gas chromatography (HR-GC and four constituents were identified, eugenol being the major component (88.6 %. The antimicrobial activity was evaluated by means of the turbidimetric method, using the microdilution assay. The minimum inhibitory concentration (MIC values of the essential oil ranged from 500 to 1,000 μg mL-1. Scanning electron microscope (SEM observations confirmed the physical damage and morphological alteration of the test bacteria treated with the essential oil, reference drugs and eugenol. The findings of the study demonstrated that this essential oil can be used in the formulation of personal care products.

  1. Antimicrobial activity of biodegradable polysaccharide and protein-based films containing active agents.

    Science.gov (United States)

    Kuorwel, Kuorwel K; Cran, Marlene J; Sonneveld, Kees; Miltz, Joseph; Bigger, Stephen W

    2011-04-01

    Significant interest has emerged in the introduction of food packaging materials manufactured from biodegradable polymers that have the potential to reduce the environmental impacts associated with conventional packaging materials. Current technologies in active packaging enable effective antimicrobial (AM) packaging films to be prepared from biodegradable materials that have been modified and/or blended with different compatible materials and/or plasticisers. A wide range of AM films prepared from modified biodegradable materials have the potential to be used for packaging of various food products. This review examines biodegradable polymers derived from polysaccharides and protein-based materials for their potential use in packaging systems designed for the protection of food products from microbial contamination. A comprehensive table that systematically analyses and categorizes much of the current literature in this area is included in the review.

  2. Mechanical and Morphological Effect of Plant Based Antimicrobial Solutions on Maxillofacial Silicone Elastomer.

    Science.gov (United States)

    Tetteh, Sophia; Bibb, Richard J; Martin, Simon J

    2018-05-30

    The objective of this study was to determine the effect of plant based antimicrobial solutions specifically tea tree and Manuka oil on facial silicone elastomers. The purpose of this in vitro study was to evaluate the effect of disinfection with plant extract solution on mechanical properties and morphology on the silicone elastomer. Test specimens were subjected to disinfection using tea tree oil, Manuka oil and the staphylococcus epidermidis bacteria. Furthermore, a procedure duration was used in the disinfection process to simulate up to one year of usage. Over 500 test specimens were fabricated for all tests performed namely hardness, elongation, tensile, tear strength tests, visual inspection and lastly surface characterization using SEM. A repeated measures ANOVA revealed that hardness and elongation at break varied significantly over the time period, whereas this was not observed in the tear and tensile strength parameters of the test samples.

  3. Mechanical and Morphological Effect of Plant Based Antimicrobial Solutions on Maxillofacial Silicone Elastomer

    Directory of Open Access Journals (Sweden)

    Sophia Tetteh

    2018-05-01

    Full Text Available The objective of this study was to determine the effect of plant based antimicrobial solutions specifically tea tree and Manuka oil on facial silicone elastomers. The purpose of this in vitro study was to evaluate the effect of disinfection with plant extract solution on mechanical properties and morphology on the silicone elastomer. Test specimens were subjected to disinfection using tea tree oil, Manuka oil and the staphylococcus epidermidis bacteria. Furthermore, a procedure duration was used in the disinfection process to simulate up to one year of usage. Over 500 test specimens were fabricated for all tests performed namely hardness, elongation, tensile, tear strength tests, visual inspection and lastly surface characterization using SEM. A repeated measures ANOVA revealed that hardness and elongation at break varied significantly over the time period, whereas this was not observed in the tear and tensile strength parameters of the test samples.

  4. Tragacanth gum as a natural polymeric wall for producing antimicrobial nanocapsules loaded with plant extract.

    Science.gov (United States)

    Ghayempour, Soraya; Montazer, Majid; Mahmoudi Rad, Mahnaz

    2015-11-01

    Tragacanth gum as a biocompatible and biodegradable polymer with good properties including emulsifying, viscosity and cross-linking ability can be used as the wall material in encapsulation of different compounds, specifically plant extracts. In this paper, for the first time, Tragacanth gum was used to produce nanocapsules containing plant extract through microemulsion method. The effect of different parameters on the average size of prepared nanocapsules in presence of aluminum and calcium chloride through ultrasonic and magnetic stirrer was investigated. The high efficient nanocapsules were prepared with spherical shape and smooth surface. The average size of nanocapsules prepared through ultrasonic using aluminum chloride (22nm) was smaller than other products. The structure of prepared nanocapsules was studied by FT-IR spectroscopy. Antimicrobial activity of different nanocapsules against Escherichia coli, Staphylococcus aureus and Candida albicans was investigated by shake flask method during their release showed 100% microbial reduction after 12h stirring. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Resistance to antimicrobial agents used for animal therapy in pathogenic , zoonotic and indicator bacteria isolated from different food animals in Denmark: A baseline study for the Danish Integrated Antimicrobial Resistance Monitoring Programme (DANMAP)

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Bager, Flemming; Jensen, N. E.

    1998-01-01

    was found. The occurrence of resistance varied by animal origin and bacterial species. In general, resistance was observed more frequently among isolates from pigs than from cattle and broilers. The association between the occurrence of resistance and the consumption of the antimicrobial is discussed......, as is the occurrence of resistance in other countries. The results of this study show the present level of resistance to antimicrobial agents among a number of bacterial species isolated from food animals in Denmark. Thus, the baseline for comparison with future prospective studies has been established, enabling......This study describes the establishment and first results of a continuous surveillance system of antimicrobial resistance among bacteria isolated from pigs, cattle and broilers in Denmark. The three categories of bacteria tested were: 1) indicator bacteria (Escherichia coli, Enterococcus faecalis...

  6. Impact of medicated feed along with clay mineral supplementation on Escherichia coli resistance to antimicrobial agents in pigs after weaning in field conditions.

    Science.gov (United States)

    Jahanbakhsh, Seyedehameneh; Kabore, Kiswendsida Paul; Fravalo, Philippe; Letellier, Ann; Fairbrother, John Morris

    2015-10-01

    The aim of this study was to examine changes in antimicrobial resistance (AMR) phenotype and virulence and AMR gene profiles in Escherichia coli from pigs receiving in-feed antimicrobial medication following weaning and the effect of feed supplementation with a clay mineral, clinoptilolite, on this dynamic. Eighty E. coli strains isolated from fecal samples of pigs receiving a diet containing chlortetracycline and penicillin, with or without 2% clinoptilolite, were examined for antimicrobial resistance to 15 antimicrobial agents. Overall, an increased resistance to 10 antimicrobials was observed with time. Supplementation with clinoptilolite was associated with an early increase but later decrease in blaCMY-2, in isolates, as shown by DNA probe. Concurrently, a later increase in the frequency of blaCMY-2 and the virulence genes iucD and tsh was observed in the control pig isolates, being significantly greater than in the supplemented pigs at day 28. Our results suggest that, in the long term, supplementation with clinoptilolite could decrease the prevalence of E. coli carrying certain antimicrobial resistance and virulence genes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Associations between the use of antimicrobial agents for growth promotion and the occurrence of resistance among Enterococcus faecium from broilers and pigs in Denmark, Finland, and Norway

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Kruse, H.; Tast, E.

    2000-01-01

    This study compares the susceptibility of Enterococcus faecium isolated from pigs and poultry in Denmark, Finland, and Norway to antimicrobial agents used for growth promotion. E. faecium was isolated from 211 broilers and 55 pigs in Denmark in 1997, from Norwegian 55 poultry farms (turkey and br......%) of the virginiamycin-resistant isolates from pigs in Denmark. This study indicates that the use of antimicrobial agents for growth promotion in Denmark, Finland, and Norway have selected for resistance to most of these drugs among E. faecium in food animals....... as resistant to monensin or salinomycin. In general, an association between the usage of antimicrobial agents in the respective countries and the occurrence of associated resistance was observed. Resistance to avilamycin was frequently observed among isolates from broilers in Denmark, where avilamycin has been...... used, whereas all isolates from Finland and Norway, where these drugs have not been used, were susceptible. The same phenomenon could be observed for avoparcin, bacitracin, tylosin, and virginiamycin; resistance was frequently observed among isolates from where these antimicrobials have been widely...

  8. Udder pathogens and their resistance to antimicrobial agents in dairy cows in Estonia

    Directory of Open Access Journals (Sweden)

    Orro Toomas

    2011-02-01

    Full Text Available Abstract Background The goal of this study was to estimate the distribution of udder pathogens and their antibiotic resistance in Estonia during the years 2007-2009. Methods The bacteriological findings reported in this study originate from quarter milk samples collected from cows on Estonian dairy farms that had clinical or subclinical mastitis. The samples were submitted by local veterinarians to the Estonian Veterinary and Food Laboratory during 2007-2009. Milk samples were examined by conventional bacteriology. In vitro antimicrobial susceptibility testing was performed with the disc diffusion test. Logistic regression with a random herd effect to control for clustering was used for statistical analysis. Results During the study period, 3058 clinical mastitis samples from 190 farms and 5146 subclinical mastitis samples from 274 farms were investigated. Positive results were found in 57% of the samples (4680 out of 8204, and the proportion did not differ according to year (p > 0.05. The proportion of bacteriologically negative samples was 22.3% and that of mixed growth was 20.6%. Streptococcus uberis (Str. uberis was the bacterium isolated most frequently (18.4% from cases of clinical mastitis, followed by Escherichia coli (E. coli (15.9% and Streptococcus agalactiae (Str. agalactiae (11.9%. The bacteria that caused subclinical mastitis were mainly Staphylococcus aureus (S. aureus (20% and coagulase-negative staphylococci (CNS (15.4%. The probability of isolating S. aureus from milk samples was significantly higher on farms that had fewer than 30 cows, when compared with farms that had more than 100 cows (p Str. agalactiae infection was found on farms with more than 600 cows (p = 0.034 compared with smaller farms. The proportion of S. aureus and CNS isolates that were resistant to penicillin was 61.4% and 38.5%, respectively. Among the E. coli isolates, ampicillin, streptomycin and tetracycline resistance were observed in 24.3%, 15.6% and 13

  9. Synthesis of Some Novel Heterocyclic and Schiff Base Derivatives as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Mohamed E. Azab

    2015-10-01

    Full Text Available Treatment of 2,3-diaryloxirane-2,3-dicarbonitriles 1a–c with different nitrogen nucleophiles, e.g., hydrazine, methyl hydrazine, phenyl hydrazine, hydroxylamine, thiosemicarbazide, and/or 2-amino-5-phenyl-1,3,4-thiadiazole, afforded pyrazole, isoxazole, pyrrolotriazine, imidazolothiadiazole derivatives 2–5, respectively. Reacting pyrazoles 2a–c with aromatic aldehydes and/or methyl glycinate produced Schiff’s bases 7a–d and pyrazolo[3,4-b]-pyrazinone derivative 8, respectively. Treating 7 with ammonium acetate and/or hydrazine hydrate, furnished the imidazolopyrazole and pyrazolotriazine derivatives 9 and 10, respectively. Reaction of 8 with chloroacetic acid and/or diethyl malonate gave tricyclic compound 11 and triketone 12, respectively. On the other hand, compound 1 was reacted with active methylene precursors, e.g., acetylacetone and/or cyclopentanone producing adducts 14a,b which upon fusion with ammonium acetate furnished the 3-pyridone derivatives 15a,b, respectively. Some of newly synthesized compounds were screened for activity against bacterial and fungal strains and most of the newly synthesized compounds showed high antimicrobial activities. The structures of the new compounds were elucidated using IR, 1H-NMR, 13C-NMR and mass spectroscopy.

  10. The detection limits of antimicrobial agents in cow's milk by a simple Yoghurt Culture Test.

    Science.gov (United States)

    Mohsenzadeh, M; Bahrainipour, A

    2008-09-15

    The aim of this study was to study performance of Yoghurt Culture Test (YCT) in the detection of antimicrobial residues in milk. For this purpose, the sensitivity of YCT for 15 antibiotics were determined. For each drug, 8 concentrations were tested. The detection limits of YCT at 2.5 h and 4 h incubation were determined (microg kg(-1)): 15 and 37.5, penicillin G; 4 and 5, ampicillin; 5 and 7.5, amoxycillin; 100 and 200, cephalexin; 80 and 100, cefazoline; 100 and 200, oxytetracycline; 500 and 100, chlortetracycline; 100 and 200, tetracycline; 150 and 200, doxycycline; 200 and 400, sulphadimidine; 500 and 1000, gentamycin; 1000 and 1500, spectinomycin; 400 and 500, erythromycin; 50 and 100, tylosin; 5000 and 10000, chloramphenicol. The YCT detection limits at 2.5 h incubation for ampicillin, cephalexin, tetracycline, oxytetracycline and tylosin are similar to those obtained as Maximum Residue Limit (MRL) according to Regulation 2377/90 EEC as set out by the European Union. In addition the detection limits of YCT for some antibiotics were lower than some of microbial inhibitor test.

  11. Biogenic synthesis of palladium nanoparticles and their applications as catalyst and antimicrobial agent.

    Science.gov (United States)

    Hazarika, Munmi; Borah, Debajit; Bora, Popymita; Silva, Ana R; Das, Pankaj

    2017-01-01

    This paper describes a simple in-situ process of synthesizing highly dispersed palladium nanoparticles (PdNPs) using aqueous leaf extract of GarciniapedunculataRoxb as bio-reductant and starch (0.3%) as bio-stabilizer. The PdNPs are characterized by techniques like FTIR, TEM, SEM-EDX, XRD and XPS analysis. It is worthnoting thatwhen the synthesis of nanoparticles was carried out in absence of starch, agglomeration of particles has been noticed.The starch-assisted PdNPs showed excellent aqueous-phase catalytic activities for three important reactions: the Suzuki-Miyaura cross-coupling reactions of aryl halides (aryl bromides and iodides) with arylboronic acids; selective oxidations of alcohols to corresponding carbonyl compounds; and reduction of toxic Cr(VI) to nontoxic Cr(III). Our catalyst could be reused up to four cycles without much compromising with its activity. Furthermore, the material also demonstrated excellent antimicrobial and anti-biofilm activities against a novel multidrug resistant clinical bacterial isolate Cronobactersakazakii strain AMD04. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PdNPswere found to be 0.06 and 0.12 mM respectively.

  12. Biogenic synthesis of palladium nanoparticles and their applications as catalyst and antimicrobial agent.

    Directory of Open Access Journals (Sweden)

    Munmi Hazarika

    Full Text Available This paper describes a simple in-situ process of synthesizing highly dispersed palladium nanoparticles (PdNPs using aqueous leaf extract of GarciniapedunculataRoxb as bio-reductant and starch (0.3% as bio-stabilizer. The PdNPs are characterized by techniques like FTIR, TEM, SEM-EDX, XRD and XPS analysis. It is worthnoting thatwhen the synthesis of nanoparticles was carried out in absence of starch, agglomeration of particles has been noticed.The starch-assisted PdNPs showed excellent aqueous-phase catalytic activities for three important reactions: the Suzuki-Miyaura cross-coupling reactions of aryl halides (aryl bromides and iodides with arylboronic acids; selective oxidations of alcohols to corresponding carbonyl compounds; and reduction of toxic Cr(VI to nontoxic Cr(III. Our catalyst could be reused up to four cycles without much compromising with its activity. Furthermore, the material also demonstrated excellent antimicrobial and anti-biofilm activities against a novel multidrug resistant clinical bacterial isolate Cronobactersakazakii strain AMD04. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of PdNPswere found to be 0.06 and 0.12 mM respectively.

  13. [Susceptibilities of Escherichia coli, Salmonella and Staphylococcus aureus isolated from animals to ofloxacin and commonly used antimicrobial agents].

    Science.gov (United States)

    Takahashi, I; Yoshida, T; Higashide, Y; Sakano, T

    1990-01-01

    Susceptibilities of Escherichia coli, Salmonella and Staphylococcus aureus isolated from chickens, pigs and cattle to ofloxacin (OFLX) and commonly used antimicrobial agents were investigated. 1. E. coli (28 isolates) demonstrated the highest level of susceptibility of OFLX (MIC 0.10-0.39 micrograms/ml for all the isolates) among all the test drugs. Commonly used antimicrobial agents to which these isolates responded with relatively high susceptibilities (MIC50 0.78-6.25 micrograms/ml) included oxolinic acid (OXA), ampicillin (ABPC), kanamycin (KM) and chloramphenicol (CP) with their MIC50 values in the increasing order as above. Drugs to which these isolates responded with moderate to weak susceptibilities (MIC50 25 approximately greater than 800 micrograms/ml) were doxycycline (DOXY), streptomycin (SM), spectinomycin (SPCM) and sulfadimethoxine (SDMX) in the increasing order of MIC50. E. coli isolates with resistances to all the test drugs other than OFLX and OXA amounted to 7.1-57.1% of the isolates examined and 20 isolates (71.4%) in total. 2. Susceptibilities to OFLX and 4 existing pyridonecarboxylic acid derivatives of E. coli (48 samples) isolated recently from diarrheal pigs were compared. When evaluated in terms of MIC50, the values of OFLX and norfloxacin were both 0.10 micrograms/ml. The values increased by differences of 0.39-3.13 micrograms/ml in an order of OXA, pipemidic acid and nalidixic acid. 3. Salmonella (28 isolates) demonstrated the highest level of susceptibility to OFLX (MIC 0.20-0.39 micrograms/ml for all the isolates) among all the test drugs. The drugs to which these isolates responded with relatively high to moderate susceptibilities (MIC50 0.78-12.5 micrograms/ml) included ABPC, OXA, DOXY, KM, CP and SM with their MIC50 values increasing in this order. The drugs to which the isolates responded with low susceptibilities (MIC50 above 100 micrograms/ml) were SPCM and SDMX. Of all the 28 Salmonella isolates tested, 7.1-32.1% were resistant

  14. Synthesis of aryl b-N-acetylglucosamine desmodified at C-6 as potential antimicrobial agents; Sintese de b-N-acetilglicosaminideos de arila modificados em C-6 como potenciais agentes antimicrobianos

    Energy Technology Data Exchange (ETDEWEB)

    Manfrini, Rozangela Magalhaes; Souza Filho, Jose Dias de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas; Figueireido, Rute Cunha; D' Angelis, Allison Fabiano; Prado, Maria Auxiliadora Fontes; Nunan, Elziria de Aguiar; Martins, Gabriela Aires; Alves, Ricardo Jose [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Dept. de Produtos Farmaceuticos]. E-mail: ricardodylan@farmacia.ufmg.br

    2008-07-01

    We report herein the synthesis of aryl beta-N-acetylglucosaminides containing azido, amino and acetamido groups at C-6 as potential antimicrobial agents. It was expected that these compounds could interfere with the biosynthesis and/or biotransformation of Nacetylglucosamine in fungi and bacteria. None of the compounds showed antimicrobial activity against bacteria (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa), filamentous fungus (Aspergillus niger) and yeasts (Saccharomyces cerevisae, Candida albicans and Candida tropicallis), at the concentration of 1 mg/mL in agar diffusion assay. (author)

  15. Evaluation of antinociceptive and antimicrobial activities of galbanum plant (Ferula gumosa Boiss

    Directory of Open Access Journals (Sweden)

    B. S. Fazly Bazzaz

    1997-08-01

    Full Text Available To evaluate the antinociceptive and antimicrobial activities of galbanum plant (Ferula gumosa, various parts of the plant were collected at specific seasons. Aerial parts and root of the plant were dried in shady place and grinded to desirable. Unnatural and natural gum resins did not have the drying and grinding stages. The alcohol-aqueous (33%extract was obtained by masuration and the solvent was removed by rotary evaporator at low temperature and vaccum condition. The essential oil was extracted by water and steam distillation. Its antinociceptive effect was investigated in mice using hot plate method. Antibacterial effect was determined using paper disk method. The results suggest that the maximum antinociceptive effect (efficacy of root and aerial parts extract was higher than morphine and maximum effect of unnatural and natural gum resins extract was equal to morphine. The maximum effect of essential oil and unnatural gum resin was less than morphine but potency of these preparations were less than morphine. The amount of microbial growth inhibition of all extracts was less than chloramphenicol (30 ;ug on gram positive bacteria, but these extracts have not any growth inhibitory effect on gram negative baceria. These extracts inhibited fungus growth equal to nystatin (100units. "nThese results in conjunction with economic considerations suggest the usefulness of aerial parts of plant for medical treatment.

  16. Antimicrobial activity of γ-thionin-like soybean SE60 in E. coli and tobacco plants

    International Nuclear Information System (INIS)

    Choi, Yeonhee; Choi, Yang Do; Lee, Jong Seob

    2008-01-01

    The SE60, a low molecular weight, sulfur-rich protein in soybean, is known to be homologous to wheat γ-purothionin. To elucidate the functional role of SE60, we expressed SE60 cDNA in Escherichia coli and in tobacco plants. A single protein band was detected by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) after anti-FLAG affinity purification of the protein from transformed E. coli. While the control E. coli cells harboring pFLAG-1 showed standard growth with Isopropyl β-D-1-thiogalactopyranoside (IPTG) induction, E. coli cells expressing the SE60 fusion protein did not grow at all, suggesting that SE60 has toxic effects on E. coli growth. Genomic integration and the expression of transgene in the transgenic tobacco plants were confirmed by Southern and Northern blot analysis, respectively. The transgenic plants demonstrated enhanced resistance against the pathogen Pseudomonas syringae. Taken together, these results strongly suggest that SE60 has antimicrobial activity and play a role in the defense mechanism in soybean plants

  17. Phenotypically anchored transcriptome profiling of developmental exposure to the antimicrobial agent, triclosan, reveals hepatotoxicity in embryonic zebrafish

    International Nuclear Information System (INIS)

    Haggard, Derik E.; Noyes, Pamela D.; Waters, Katrina M.; Tanguay, Robert L.

    2016-01-01

    Triclosan (TCS) is an antimicrobial agent commonly found in a variety of personal care products and cosmetics. TCS readily enters the environment through wastewater and is detected in human plasma, urine, and breast milk due to its widespread use. Studies have implicated TCS as a disruptor of thyroid and estrogen signaling; therefore, research examining the developmental effects of TCS is warranted. In this study, we used embryonic zebrafish to investigate the developmental toxicity and potential mechanism of action of TCS. Embryos were exposed to graded concentrations of TCS from 6 to 120 hours post-fertilization (hpf) and the concentration where 80% of the animals had mortality or morbidity at 120 hpf (EC 80 ) was calculated. Transcriptomic profiling was conducted on embryos exposed to the EC 80 (7.37 μM). We identified a total of 922 significant differentially expressed transcripts (FDR adjusted P-value ≤ 0.05; fold change ≥ 2). Pathway and gene ontology enrichment analyses identified biological networks and transcriptional hubs involving normal liver functioning, suggesting TCS may be hepatotoxic in zebrafish. Tissue-specific gene enrichment analysis further supported the role of the liver as a target organ for TCS toxicity. We also examined the in vitro bioactivity profile of TCS reported by the ToxCast screening program. TCS had a diverse bioactivity profile and was a hit in 217 of the 385 assay endpoints we identified. We observed similarities in gene expression and hepatic steatosis assays; however, hit data for TCS were more concordant with the hypothesized CAR/PXR activity of TCS from rodent and human in vitro studies. - Highlights: • Triclosan is a common antimicrobial agent with widespread human exposure. • Exposure to the triclosan EC 80 causes robust gene expression changes in zebrafish. • The liver may be a target organ of triclosan toxicity in embryonic zebrafish. • Triclosan disrupts normal liver functioning and development in

  18. Phenotypically anchored transcriptome profiling of developmental exposure to the antimicrobial agent, triclosan, reveals hepatotoxicity in embryonic zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Haggard, Derik E. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR (United States); Noyes, Pamela D. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR (United States); Office of Science Coordination and Policy (OSCP), Office of Chemical Safety and Pollution Prevention, U.S. Environmental Protection Agency, Washington, DC (United States); Waters, Katrina M. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA (United States); Tanguay, Robert L., E-mail: Robert.Tanguay@oregonstate.edu [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR (United States)

    2016-10-01

    Triclosan (TCS) is an antimicrobial agent commonly found in a variety of personal care products and cosmetics. TCS readily enters the environment through wastewater and is detected in human plasma, urine, and breast milk due to its widespread use. Studies have implicated TCS as a disruptor of thyroid and estrogen signaling; therefore, research examining the developmental effects of TCS is warranted. In this study, we used embryonic zebrafish to investigate the developmental toxicity and potential mechanism of action of TCS. Embryos were exposed to graded concentrations of TCS from 6 to 120 hours post-fertilization (hpf) and the concentration where 80% of the animals had mortality or morbidity at 120 hpf (EC{sub 80}) was calculated. Transcriptomic profiling was conducted on embryos exposed to the EC{sub 80} (7.37 μM). We identified a total of 922 significant differentially expressed transcripts (FDR adjusted P-value ≤ 0.05; fold change ≥ 2). Pathway and gene ontology enrichment analyses identified biological networks and transcriptional hubs involving normal liver functioning, suggesting TCS may be hepatotoxic in zebrafish. Tissue-specific gene enrichment analysis further supported the role of the liver as a target organ for TCS toxicity. We also examined the in vitro bioactivity profile of TCS reported by the ToxCast screening program. TCS had a diverse bioactivity profile and was a hit in 217 of the 385 assay endpoints we identified. We observed similarities in gene expression and hepatic steatosis assays; however, hit data for TCS were more concordant with the hypothesized CAR/PXR activity of TCS from rodent and human in vitro studies. - Highlights: • Triclosan is a common antimicrobial agent with widespread human exposure. • Exposure to the triclosan EC{sub 80} causes robust gene expression changes in zebrafish. • The liver may be a target organ of triclosan toxicity in embryonic zebrafish. • Triclosan disrupts normal liver functioning and

  19. Antimicrobial, Antioxidant, and Anti-Inflammatory Activities of Essential Oils of Selected Aromatic Plants from Tajikistan

    Directory of Open Access Journals (Sweden)

    Farukh Sharopov

    2015-11-01

    Full Text Available Antimicrobial, antioxidant, and anti-inflammatory activities of the essential oils of 18 plant species from Tajikistan (Central Asia were investigated. The essential oil of Origanum tyttanthum showed a strong antibacterial activity with both minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC values of 312.5 µg/mL for E. coli, 625 µg/mL (MIC and 1250 µg/mL (MBC for MRSA (methicillin-resistant Staphylococcus aureus, respectively. The essential oil of Galagania fragrantissima was highly active against MRSA at concentrations as low as 39.1 µg/mL and 78.2 µg/mL for MIC and MBC, respectively. Origanum tyttanthum essential oil showed the highest antioxidant activity with IC50 values of 0.12 mg/mL for ABTS (2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid and 0.28 mg/mL for DPPH (2,2-diphenyl-1-picrylhydrazyl. Galagania fragrantissima and Origanum tyttanthum essential oils showed the highest anti-inflammatory activity; IC50 values of 5-lipoxygenase (5-LOX inhibition were 7.34 and 14.78 µg/mL, respectively. In conclusion, essential oils of Origanum tyttanthum and Galagania fragrantissima exhibit substantial antimicrobial, antioxidant, and anti-inflammatory activities. They are interesting candidates in phytotherapy.

  20. Antimicrobial, Antioxidant, and Anti-Inflammatory Activities of Essential Oils of Selected Aromatic Plants from Tajikistan.

    Science.gov (United States)

    Sharopov, Farukh; Braun, Markus Santhosh; Gulmurodov, Isomiddin; Khalifaev, Davlat; Isupov, Salomiddin; Wink, Michael

    2015-11-02

    Antimicrobial, antioxidant, and anti-inflammatory activities of the essential oils of 18 plant species from Tajikistan (Central Asia) were investigated. The essential oil of Origanum tyttanthum showed a strong antibacterial activity with both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 312.5 µg/mL for E. coli , 625 µg/mL (MIC) and 1250 µg/mL (MBC) for MRSA (methicillin-resistant Staphylococcus aureus), respectively. The essential oil of Galagania fragrantissima was highly active against MRSA at concentrations as low as 39.1 µg/mL and 78.2 µg/mL for MIC and MBC, respectively. Origanum tyttanthum essential oil showed the highest antioxidant activity with IC 50 values of 0.12 mg/mL for ABTS (2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid)) and 0.28 mg/mL for DPPH (2,2-diphenyl-1-picrylhydrazyl) . Galagania fragrantissima and Origanum tyttanthum essential oils showed the highest anti-inflammatory activity; IC 50 values of 5-lipoxygenase (5-LOX) inhibition were 7.34 and 14.78 µg/mL, respectively. In conclusion, essential oils of Origanum tyttanthum and Galagania fragrantissima exhibit substantial antimicrobial, antioxidant, and anti-inflammatory activities. They are interesting candidates in phytotherapy.

  1. Evaluation of Chitosan/Fructose Model as an Antioxidant and Antimicrobial Agent for Shelf Life Extension of Beef Meat During Freezing

    Directory of Open Access Journals (Sweden)

    Shaheen Mohmed S.

    2016-12-01

    Full Text Available In the present study the effect of chitosan/fructose Maillard reaction products (CF-MRPs as antioxidant and antimicrobial agents was evaluated and applied on minced beef meat during frozen storage. Antioxidant and antimicrobial properties of chitosan-fructose complexes were tested. Anti-oxidant properties were measured by the DPPH, β-carotene and ABTS methods. These three methods showed the same profile of antioxidant activity. Chitosan with 4% fructose autoclaved for 45 min (CF9 showed to have the most effective antioxidant activity. It was demonstrated that the browning product exhibited antioxidant activity. For antimicrobial activity, most chitosan-fructose complexes were less effective than chitosan. Thus, MRPs derived from chitosan-sugar model system can be promoted as a novel antioxidant to prevent lipid oxidation in minced beef. Chitosan-sugar complex could be a potential alternative natural product for synthetic food additive replacement that would additionally meet consumer safety requirement.

  2. Ruthenium (II) complexes of thiosemicarbazone: Synthesis, biosensor applications and evaluation as antimicrobial agents

    Energy Technology Data Exchange (ETDEWEB)

    Yildirim, Hatice [Dokuz Eylul University, The Graduate School of Natural and Applied Sciences, Department of Chemistry, 35160 Buca, Izmir (Turkey); Guler, Emine [Ege University, Faculty of Science, Department of Biochemistry, 35100 Bornova, Izmir (Turkey); Yavuz, Murat, E-mail: myavuz@dicle.edu.tr [Ege University, Faculty of Science, Department of Biochemistry, 35100 Bornova, Izmir (Turkey); Dicle University, Faculty of Science, Department of Chemistry, 21280 Diyarbakir (Turkey); Ozturk, Nurdan; Kose Yaman, Pelin [Dokuz Eylul University, The Graduate School of Natural and Applied Sciences, Department of Chemistry, 35160 Buca, Izmir (Turkey); Subasi, Elif; Sahin, Elif [Dokuz Eylul University, Faculty of Science, Department of Chemistry, 35160 Buca, Izmir (Turkey); Timur, Suna [Ege University, Faculty of Science, Department of Biochemistry, 35100 Bornova, Izmir (Turkey); Ege University, Institute on Drug Abuse, Toxicology and Pharmaceutical Science (BATI), 35100 Bornova, Izmir (Turkey)

    2014-11-01

    A conformationally rigid half-sandwich organoruthenium (II) complex [(η{sup 6}-p-cymene)RuClTSC{sup N–S}]Cl, (1) and carbonyl complex [Ru(CO)Cl(PPh{sub 3}){sub 2}TSC{sup N–S}] (2) have been synthesized from the reaction of [{(η"6-p-cymene)RuCl}{sub 2}(μ-Cl){sub 2}] and [Ru(H)(Cl)(CO)(PPh{sub 3}){sub 3}] with thiophene-2-carboxaldehyde thiosemicarbazon (TSC) respectively and both novel ruthenium (II) complexes have been characterized by elemental analysis, FT-IR and NMR spectroscopy. The peripheral TSC in the complexes acts as an electrochemical coupling unit providing the ability to carry out electrochemical deposition (ED) and to form an electro-deposited film on a graphite electrode surface. The biosensing applicability of complexes 1 and 2 was investigated by using glucose oxidase (GOx) as a model enzyme. Electrochemical measurements at − 0.9 V versus Ag/AgCl electrode by following the ED Ru(II) reduction/oxidation due to from the enzyme activity, in the presence of glucose substrate. The designed biosensor showed a very good linearity for 0.01–0.5 mM glucose. The in vitro antimicrobial activities of complexes 1 and 2 were also investigated against nine bacterial strains and one fungus by the disc diffusion test method. No activity was observed against the Gram-negative strains and fungus, whereas complex 1 showed moderate antibacterial activities against Gram-positive bacterial strains. - Highlights: • Novel Ru (II) thiosemicarbazone complexes were synthesized and characterized. • Electrochemical depositions were performed. • Rigid half-sandwich Ru (II) complex showed enhanced antibacterial activity.

  3. Ruthenium (II) complexes of thiosemicarbazone: Synthesis, biosensor applications and evaluation as antimicrobial agents

    International Nuclear Information System (INIS)

    Yildirim, Hatice; Guler, Emine; Yavuz, Murat; Ozturk, Nurdan; Kose Yaman, Pelin; Subasi, Elif; Sahin, Elif; Timur, Suna

    2014-01-01

    A conformationally rigid half-sandwich organoruthenium (II) complex [(η 6 -p-cymene)RuClTSC N–S ]Cl, (1) and carbonyl complex [Ru(CO)Cl(PPh 3 ) 2 TSC N–S ] (2) have been synthesized from the reaction of [{(η 6 -p-cymene)RuCl} 2 (μ-Cl) 2 ] and [Ru(H)(Cl)(CO)(PPh 3 ) 3 ] with thiophene-2-carboxaldehyde thiosemicarbazon (TSC) respectively and both novel ruthenium (II) complexes have been characterized by elemental analysis, FT-IR and NMR spectroscopy. The peripheral TSC in the complexes acts as an electrochemical coupling unit providing the ability to carry out electrochemical deposition (ED) and to form an electro-deposited film on a graphite electrode surface. The biosensing applicability of complexes 1 and 2 was investigated by using glucose oxidase (GOx) as a model enzyme. Electrochemical measurements at − 0.9 V versus Ag/AgCl electrode by following the ED Ru(II) reduction/oxidation due to from the enzyme activity, in the presence of glucose substrate. The designed biosensor showed a very good linearity for 0.01–0.5 mM glucose. The in vitro antimicrobial activities of complexes 1 and 2 were also investigated against nine bacterial strains and one fungus by the disc diffusion test method. No activity was observed against the Gram-negative strains and fungus, whereas complex 1 showed moderate antibacterial activities against Gram-positive bacterial strains. - Highlights: • Novel Ru (II) thiosemicarbazone complexes were synthesized and characterized. • Electrochemical depositions were performed. • Rigid half-sandwich Ru (II) complex showed enhanced antibacterial activity

  4. Antimicrobial Activity of Plant Extracts from Aloe Vera, Citrus Hystrix, Sabah Snake Grass and Zingiber Officinale against Pyricularia Oryzae that causes Rice Blast Disease in Paddy Plants

    Science.gov (United States)

    Uda, M. N. A.; Harzana Shaari, N.; Shamiera. Said, N.; Hulwani Ibrahim, Nur; Akhir, Maisara A. M.; Khairul Rabani Hashim, Mohd; Salimi, M. N.; Nuradibah, M. A.; Hashim, Uda; Gopinath, Subash C. B.

    2018-03-01

    Rice blast disease, caused by the fungus known as Pyricularia oryzae, has become an important and serious disease of rice worldwide. Around 50% of production may be lost in a field moderately affected by infection and each year the fungus destroys rice, which is enough to feed an estimated 60 million people. Therefore, use of herbal plants offer an alternative for the management of plant diseases. Herbal plant like Aloe vera, Citrus hystrix, Sabah snake grass and Zingiber officinale extracts can be used for controlling disease of rice blast. In this study, these four herbal plants were used for evaluating antimicrobial activity against rice plant fungus Pyricularia oryzae, which causes rice blast disease.

  5. Antimicrobial Effect of 15 Medicinal Plant Species and their Dependency on Climatic Conditions of Growth in Different Geographical and Ecological Areas of Fars Province

    Directory of Open Access Journals (Sweden)

    Abbas Abdollahi

    2012-05-01

    Full Text Available Background: The effects of medicinal plants are variable in different conditions. Here, the antimicrobial effect of 15 medicinal plant species and their dependency on the climatic condition of growth in different geographical and ecological areas of Fars Province were studied. Materials and Methods: In This empirical study, the antimicrobial effect of hydro-alcoholic extract of 15 medicinal plant species was examined against standard bacterial strains comparing to conventional therapeutic antibiotics using disk diffusion assay and serial broth dilution. Results: All Extracts were effective against S.aureus ATCC 25923 growth; also Peganum harmala, Myrtus communis, Mentha pulegium, Mentha spp, and Zataria multiflora extracts were observed to have antimicrobial activity against E.coli ATCC 25922. This antimicrobial activity had partially similar results, comparing to conventional antibioticsConclusion: Medicinal plants produce various amounts of antimicrobial substances under the climatic and ecological conditions of each zone, which must be considered in manufacturing herbal medicines.

  6. Plant location and extraction procedure strongly alter the antimicrobial activity of murta extracts

    DEFF Research Database (Denmark)

    Shene, Carolina; Reyes, Agnes K.; Villarroel, Mario

    2009-01-01

    plants grown nearer to the mountain (58 mg GAE/g murta), subjected to extreme summer/winter-day/night temperature changes and rainy regime. Extracts from leaves collected in the valley and coast contained 46 and 40 mg GAE/g murta, respectively. A mixture of 50% ethanol/water was the most efficient......Leaves and fruits of Murta (Ugni Molinae Turcz.) growing in three locations of Chile with diverse climatic conditions were extracted by using ethanol/water mixtures at different ratios and the antimicrobial activity was assessed. Extracts containing the highest polyphenolic content were from murta...... in extracting polyphenols, showing pure solvents-both water and ethanol-a lower extraction capacity. No correlation between antioxidant capacity and polyphenolic content was found. Extracts from Murta leaves provoked a decrease in the growing of Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus...

  7. Occurrence of Salmonella spp. in broiler chicken carcasses and their susceptibility to antimicrobial agents Ocorrência de Salmonella spp. em carcaças de frango e sua suscetibilidade a agentes antimicrobianos

    Directory of Open Access Journals (Sweden)

    Dalila Angélica Moliterno Duarte

    2009-09-01

    Full Text Available The present study was carried out to evaluate the occurrence of Salmonellae in broiler chicken carcasses and to determine the antimicrobial resistance profile of the isolated strains. Twenty-five out of the 260 broiler chicken carcasses samples (9.6% were positive for Salmonella. S. Enteritidis was the most frequent serovar. Nineteen Salmonella isolates were tested for antimicrobial resistance, and the results indicated that 94.7% were resistant to at least one antimicrobial agent. Resistance to streptomycin (73.7%, nitrofurantoin (52.3%, tetracycline (31.6%, and nalidixic acid (21% were the prevalent amongst Salmonella strains tested.O presente estudo teve como objetivo verificar a ocorrência de Salmonellae em amostras de carcaças de frango e a suscetibilidade dos isolados a agentes antimicrobianos. Das 260 carcaças analisadas, 25 (9,6% foram positivas para Salmonella. Salmonella Enteritidis foi o sorovar predominante. Com relação à suscetibilidade a agentes antimicrobianos, 94,7% das cepas de Salmonella testadas, apresentaram resistência a um ou mais agentes antimicrobianos. Os perfís de resistência mais comumente observados entre os isolados foram a resistência à estreptomicina (73,7%, nitrofurantoína (52,3%, tetraciclina (31,6% e ácido nalidíxico (21%.

  8. Gold Nanoparticles: An Efficient Antimicrobial Agent against Enteric Bacterial Human Pathogen

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    Shahzadi Shamaila

    2016-04-01

    Full Text Available Enteric bacterial human pathogens, i.e., Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Klebsiella pneumoniae, are the major cause of diarrheal infections in children and adults. Their structure badly affects the human immune system. It is important to explore new antibacterial agents instead of antibiotics for treatment. This project is an attempt to explain how gold nanoparticles affect these bacteria. We investigated the important role of the mean particle size, and the inhibition of a bacterium is dose-dependent. Ultra Violet (UV-visible spectroscopy revealed the size of chemically synthesized gold nanoparticle as 6–40 nm. Atomic force microscopy (AFM analysis confirmed the size and X-ray diffractometry (XRD analysis determined the polycrystalline nature of gold nanoparticles. The present findings explained how gold nanoparticles lyse Gram-negative and Gram-positive bacteria.

  9. In Vitro Activity of Antimicrobial Agents against Isolates from Patients with Acute Tonsillopharyngitis in Dakar, Senegal

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    A. Gueye Ndiaye

    2009-01-01

    Full Text Available Streptococcus pyogenes ( S. pyogenes is the most important causative agent of tonsillopharyngitis. Beta-lactam antibiotics, particularly penicillin, are the drug of first choice and macrolides are recommended for patients who are allergic to penicillin. However, other antibiotics are also used for the treatment of streptococcal tonsillopharyngitis. In recent years, the increase in the incidence of respiratory tract pathogens that are resistant to current antibacterial agents highlights the need to monitor the evolution of the resistance of these pathogens to antibiotics. In this study, we assess the susceptibility of 98 isolates of S. pyogenes to 16 antibiotics. The pathogens were recovered from patients with acute tonsillopharyngitis in Dakar, the Senegalese capital city, who were recruited from May 2005 to August 2006. All strains were susceptible to penicillin with low Minimum Inhibitory Concentration (MIC = 0,016 mg/L. Amoxicillin had high activity (100% showing its importance in treatment of streptococcal infections. Cephalosporins had MIC 90 values ranging from 0.016 to 0.094 mg/L. Macrolides have shown high activity. All strains were resistant to tetracyclin. Other molecules such as teicoplanin, levofloxacin and chloramphenicol were also active and would represent alternatives to treatment of tonsillopharyngitis due to this pathogen. These results indicate that no significant resistance to antibiotics was found among patients with tonsillopharyngitis studied in Dakar. Limitations of this study were that the number of isolates tested was small and all isolates were collected from one hospital in Dakar. Hence, results may not be representative of the isolates found, in the wider community or other regions of Senegal. Further studies are needed in other parts of Dakar and other geographic regions of Senegal, in order to better clarify the antibiotic susceptibility profile of S. pyogenes isolates recovered from patients with

  10. Poly(vinyl chloride) catheters modified with pH-responsive poly(methacrylic acid) with affinity for antimicrobial agents

    Science.gov (United States)

    Zuñiga-Zamorano, Ivette; Meléndez-Ortiz, H. Iván; Costoya, Alejandro; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Bucio, Emilio

    2018-01-01

    Radiation-grafting of pH-responsive methacrylic acid (MAA) onto poly(vinyl chloride) (PVC) was carried out by the pre-irradiation method using gamma rays, which demonstrated to be an efficient and fast procedure for obtaining PVC-g-MAA copolymers. The influence of preparation conditions, such as absorbed dose, monomer concentration, reaction time, and reaction temperature on the grafting yield was studied. The grafting of MAA onto PVC catheters was confirmed by means of Fourier transform infrared spectroscopy (FT-IR), thermogravimetry analysis (TGA), and differential scanning calorimetry (DSC). The pH-responsiveness of the grafted copolymers (critical point 8.5) was measured by swelling under cyclic changes in the pH of the medium. Interestingly, PVC-g-MAA showed enhanced capability to immobilize benzalkonium chloride and, particularly, ciprofloxacin and to sustain the release this antimicrobial agent at both acid and alkaline pH. Tests carried out with Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus point out that the developed functionalized catheters may play a role in the prevention/management of urinary tract infections.

  11. Susceptibility to antimicrobial agents among bovine mastitis pathogens isolated from North American dairy cattle, 2002-2010.

    Science.gov (United States)

    Lindeman, Cynthia J; Portis, Ellen; Johansen, Lacie; Mullins, Lisa M; Stoltman, Gillian A

    2013-09-01

    Approximately 8,000 isolates of Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Staphylococcus aureus, and Escherichia coli, isolated by 25 veterinary laboratories across North America between 2002 and 2010, were tested for in vitro susceptibility to beta-lactam, macrolide, and lincosamide drugs. The minimal inhibitory concentrations (MICs) of the beta-lactam drugs remained low against most of the Gram-positive strains tested, and no substantial changes in the MIC distributions were seen over time. Of the beta-lactam antimicrobial agents tested, only ceftiofur showed good in vitro activity against E. coli. The MICs of the macrolides and lincosamides also remained low against Gram-positive mastitis pathogens. While the MIC values given by 50% of isolates (MIC50) for erythromycin and pirlimycin and the streptococci were all low (≤0.5 µg/ml), the MIC values given by 90% of isolates (MIC90) were higher and more variable, but with no apparent increase over time. Staphylococcus aureus showed little change in erythromycin susceptibility over time, but there may be a small, numerical increase in pirlimycin MIC50 and MIC90 values. Overall, the results suggest that mastitis pathogens in the United States and Canada have not shown any substantial changes in the in vitro susceptibility to beta-lactam, macrolide, and lincosamide drugs tested over the 9 years of the study.

  12. Antimicrobial biosynthetic potential and genetic diversity of endophytic actinomycetes associated with medicinal plants.

    Science.gov (United States)

    Gohain, Anwesha; Gogoi, Animesh; Debnath, Rajal; Yadav, Archana; Singh, Bhim P; Gupta, Vijai K; Sharma, Rajeev; Saikia, Ratul

    2015-10-01

    Endophytic actinomycetes are one of the primary groups that share symbiotic relationships with medicinal plants and are key reservoir of biologically active compounds. In this study, six selective medicinal plants were targeted for the first time for endophytic actinomycetes isolation from Gibbon Wild Life Sanctuary, Assam, India, during winter and summer and 76 isolates were obtained. The isolates were found to be prevalent in roots followed by stem and leaves. 16S rRNA gene sequence analysis revealed 16 genera, including rare genera, Verrucosispora, Isoptericola and Kytococcus, which have never been previously reported as endophytic. The genus Streptomyces (66%) was dominant in both seasons. Shannon's diversity index showed that Azadirachta indica (1.49), Rauwolfia serpentina (1.43) and Emblica officinalis (1.24) were relatively good habitat for endophytic actinomycetes. Antimicrobial strains showed prevalence of polyketide synthase (PKS) type-II (85%) followed by PKS type-I (14%) encoded in the genomes. Expression studies showed 12-fold upregulation of PKSII gene in seventh day of incubation for Streptomyces antibioticus (EAAG90). Our results emphasize that the actinomycetes assemblages within plant tissue exhibited biosynthetic systems encoding for important biologically active compounds. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. A split-body, randomized, blinded study to evaluate the efficacy of a topical spray composed of essential oils and essential fatty acids from plant extracts with antimicrobial properties.

    Science.gov (United States)

    Bensignor, Emmanuel; Fabriès, Lionel; Bailleux, Lucie

    2016-12-01

    Bacterial pyoderma is a frequent presentation in dogs. Despite the widespread availability of effective systemic and topical antimicrobial products, good clinical practice currently recommends avoidance of long-term use to mitigate the development of bacterial resistance. To evaluate the speed of resolution of clinical signs of bacterial pyoderma in dogs treated with a systemic antimicrobial agent with or without the use of an adjunctive spray with antimicrobial properties. Twelve dogs with superficial bacterial pyoderma. In this controlled and blinded study, all dogs were treated with oral cefalexin and a topical spray (PYOClean Spray) for 4 weeks. The spray was applied to one half of each dog's body, whereas a placebo spray was applied to the other half. Twelve dogs completed the study. Mean clinical scores were significantly reduced on spray-treated sites, for test product and placebo (respectively), by 47% and 34% at Week 1, 83% and 60% at Week 2, 95% and 82% at Week 3, and 100% and 96% at Week 4. Fifty percent of treated sites were considered clinically and cytologically cured at Week 2, 83% at Week 3, and 100% at Week 4 compared to 8%, 50% and 83% for the placebo sites, respectively. These results demonstrate that use of a topical spray which contains plant-derived essential oils and fatty acids, and compounds with antimicrobial properties (Manuka oil and N-acetyl cysteine) may help to speed resolution of pyoderma and may allow for shorter antimicrobial treatment time. © 2016 ESVD and ACVD.

  14. The rhizospheres of traditional medicinal plants in Panxi, China, host a diverse selection of actinobacteria with antimicrobial properties.

    Science.gov (United States)

    Zhao, Ke; Penttinen, Petri; Chen, Qiang; Guan, Tongwei; Lindström, Kristina; Ao, Xiaoling; Zhang, Lili; Zhang, Xiaoping

    2012-06-01

    Actinobacteria are a prolific source of antibiotics. Since the rate of discovery of novel antibiotics is decreasing, actinobacteria from unique environments need to be explored. In particular, actinobacterial biocontrol strains from medicinal plants need to be studied as they can be a source of potent antibiotics. We combined culture-dependent and culture-independent methods in analyzing the actinobacterial diversity in the rhizosphere of seven traditional medicinal plant species from Panxi, China, and assessed the antimicrobial activity of the isolates. Each of the plant species hosted a unique set of actinobacterial strains. Out of the 64 morphologically distinct isolates, half were Streptomyces sp., eight were Micromonospora sp., and the rest were members of 18 actinobacterial genera. In particular, Ainsliaea henryi Diels. hosted a diverse selection of actinobacteria, although the 16S ribosomal RNA (rRNA) sequence identity ranges of the isolates and of the 16S rRNA gene clone library were not congruent. In the clone library, 40% of the sequences were related to uncultured actinobacteria, emphasizing the need to develop isolation methods to assess the full potential of the actinobacteria. All Streptomyces isolates showed antimicrobial activity. While the antimicrobial activities of the rare actinobacteria were limited, the growth of Escherichia coli, Verticillium dahliae, and Fusarium oxysporum were inhibited only by rare actinobacteria, and strains related to Saccharopolyspora shandongensis and Streptosporangium roseum showed broad antimicrobial activity.

  15. Synthesis of silver nanoparticles using Dioscorea bulbifera tuber extract and evaluation of its synergistic potential in combination with antimicrobial agents

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    Ghosh S

    2012-02-01

    -positive bacteria. Beta-lactam (piperacillin and macrolide (erythromycin antibiotics showed a 3.6-fold and 3-fold increase, respectively, in combination with silver nanoparticles selectively against multidrug-resistant Acinetobacter baumannii. Notable synergy was seen between silver nanoparticles and chloramphenicol or vancomycin against Pseudomonas aeruginosa, and was supported by a 4.9-fold and 4.2-fold increase in zone diameter, respectively. Similarly, we found a maximum 11.8-fold increase in zone diameter of streptomycin when combined with silver nanoparticles against E. coli, providing strong evidence for the synergistic action of a combination of antibiotics and silver nanoparticles.Conclusion: This is the first report on the synthesis of silver nanoparticles using D. bulbifera tuber extract followed by an estimation of its synergistic potential for enhancement of the antibacterial activity of broad spectrum antimicrobial agents.Keywords: Dioscorea bulbifera tuber extract, silver nanoparticles, antimicrobial synergy

  16. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

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    Nadal Anna

    2012-09-01

    Full Text Available Abstract Background The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER, analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP, had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM

  17. The human milk protein-lipid complex HAMLET sensitizes bacterial pathogens to traditional antimicrobial agents.

    Science.gov (United States)

    Marks, Laura R; Clementi, Emily A; Hakansson, Anders P

    2012-01-01

    The fight against antibiotic resistance is one of the most significant challenges to public health of our time. The inevitable development of resistance following the introduction of novel antibiotics has led to an urgent need for the development of new antibacterial drugs with new mechanisms of action that are not susceptible to existing resistance mechanisms. One such compound is HAMLET, a natural complex from human milk that kills Streptococcus pneumoniae (the pneumococcus) using a mechanism different from common antibiotics and is immune to resistance-development. In this study we show that sublethal concentrations of HAMLET potentiate the effect of common antibiotics (penicillins, macrolides, and aminoglycosides) against pneumococci. Using MIC assays and short-time killing assays we dramatically reduced the concentrations of antibiotics needed to kill pneumococci, especially for antibiotic-resistant strains that in the presence of HAMLET fell into the clinically sensitive range. Using a biofilm model in vitro and nasopharyngeal colonization in vivo, a combination of HAMLET and antibiotics completely eradicated both biofilms and colonization in mice of both antibiotic-sensitive and resistant strains, something each agent alone was unable to do. HAMLET-potentiation of antibiotics was partially due to increased accessibility of antibiotics to the bacteria, but relied more on calcium import and kinase activation, the same activation pathway HAMLET uses when killing pneumococci by itself. Finally, the sensitizing effect was not confined to species sensitive to HAMLET. The HAMLET-resistant respiratory species Acinetobacter baumanii and Moraxella catarrhalis were all sensitized to various classes of antibiotics in the presence of HAMLET, activating the same mechanism as in pneumococci. Combined these results suggest the presence of a conserved HAMLET-activated pathway that circumvents antibiotic resistance in bacteria. The ability to activate this pathway may extend

  18. Key considerations on nebulization of antimicrobial agents to mechanically ventilated patients.

    Science.gov (United States)

    Rello, J; Rouby, J J; Sole-Lleonart, C; Chastre, J; Blot, S; Luyt, C E; Riera, J; Vos, M C; Monsel, A; Dhanani, J; Roberts, J A

    2017-09-01

    Nebulized antibiotics have an established role in patients with cystic fibrosis or bronchiectasis. Their potential benefit to treat respiratory infections in mechanically ventilated patients is receiving increasing interest. In this consensus statement of the European Society of Clinical Microbiology and Infectious Diseases, the body of evidence of the therapeutic utility of aerosolized antibiotics in mechanically ventilated patients was reviewed and resulted in the following recommendations: Vibrating-mesh nebulizers should be preferred to jet or ultrasonic nebulizers. To decrease turbulence and limit circuit and tracheobronchial deposition, we recommend: (a) the use of specifically designed respiratory circuits avoiding sharp angles and characterized by smooth inner surfaces, (b) the use of specific ventilator settings during nebulization including use of a volume controlled mode using constant inspiratory flow, tidal volume 8 mL/kg, respiratory frequency 12 to 15 bpm, inspiratory:expiratory ratio 50%, inspiratory pause 20% and positive end-expiratory pressure 5 to 10 cm H 2 O and (c) the administration of a short-acting sedative agent if coordination between the patient and the ventilator is not obtained, to avoid patient's flow triggering and episodes of peak decelerating inspiratory flow. A filter should be inserted on the expiratory limb to protect the ventilator flow device and changed between each nebulization to avoid expiratory flow obstruction. A heat and moisture exchanger and/or conventional heated humidifier should be stopped during the nebulization period to avoid a massive loss of aerosolized particles through trapping and condensation. If these technical requirements are not followed, there is a high risk of treatment failure and adverse events in mechanically ventilated patients receiving nebulized antibiotics for pneumonia. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights

  19. Emerging Gram negative resistance to last-line antimicrobial agents fosfomycin, colistin and ceftazidime-avibactam - epidemiology, laboratory detection and treatment implications.

    Science.gov (United States)

    Sherry, Norelle; Howden, Benjamin

    2018-04-01

    Multidrug-resistant (MDR) and extensively-drug-resistant (XDR) Gram-negative bacteria have emerged as a major threat to human health globally. This has resulted in the 're-discovery' of some older antimicrobials and development of new agents, however resistance has also rapidly emerged to these agents. Areas covered: Here we describe recent developments in resistance to three of the most important last-line antimicrobials for treatment of MDR and XDR Gram negatives: fosfomycin, colistin and ceftazidime-avibactam. Expert commentary: A key challenge for microbiologists and clinicians using these agents for treating patients with MDR and XDR Gram negative infections is the need to ensure appropriate reference methods are being used to test susceptibility to these agents, especially colistin and fosfomycin. These methods are not available in all laboratories meaning accurate results are either delayed, or potentially inaccurate as non-reference methods are employed. Combination therapy for MDR and XDR Gram negatives is likely to become more common, and future studies should focus on the clinical effects of monotherapy vs combination therapy, as well as validation of synergy testing methods. Effective national and international surveillance systems to detect and respond to resistance to these last line agents are also critical.

  20. Antimicrobial Activity of Isothiocyanates from Cruciferous Plants against Methicillin-Resistant Staphylococcus aureus (MRSA

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    Carla Dias

    2014-10-01

    Full Text Available Purified isothiocyanates from cruciferous plants (Brassicacea, Syn. Cruciferae plants were evaluated against 15 isolates of methicillin-resistant S. aureus isolated from diabetic foot-ulcer patients aiming the study of the potential usage of allyl-isothiocyanate, benzyl-isothiocyanate and 2-phenylethyl-isothiocyanate against this important bacteria. Disc diffusion and minimum inhibitory concentration methods were used to access the antimicrobial activity. The index (Ia and rate (Ra of the antibacterial activity for each compound were calculated. The results showed a highly dose-dependent compound and chemical structure antibacterial effectiveness. The results showed a strong relation between the chemical structure of isothiocyanates and its antibacterial effectiveness. The benzyl-isothiocyanate was the most effective with a minimum inhibitory concentration varying between 2.9 and 110 µg·mL−1 with an antibacterial activity rate up to 87%. Moreover, their antibacterial activity was mainly bactericidal. This study provides scientific evidence that isothiocyanates have an interesting biological value and must be considered as an important tool to be used against MRSA.

  1. Exopolysaccharide Gellan Gum and Derived Oligo-Gellan Enhance Growth and Antimicrobial Activity in Eucomis Plants

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    Piotr Salachna

    2018-02-01

    Full Text Available One of the visible trends in the cultivation of plants, particularly of medicinal ones, is the increasing interest of researchers in polysaccharides and their derivatives that show biostimulatory properties and are also safe to use. In the current study, we evaluated the effects of gellan gum and its depolymerized form oligo-gellan, on growth and antimicrobial activity of two ornamental species Eucomis bicolor and Eucomis comosa used in natural medicine. The biopolymers were applied in the form of bulb coating prepared by using polyelectrolyte complexes. In both species investigated, gellan gum and oligo-gellan enhanced the fresh weight of leaves and bulbs, the performance of the photosynthetic apparatus, and the leaf content of basic macronutrients. In comparison with the control, the plants treated with oligo-gellan accumulated more biomass, were first to flower, and had the highest leaf content of potassium. The extracts from the bulbs treated with gellan gum and oligo-gellan showed higher effectiveness in reducing the count of Bacillus atrophaeus, Escherichia coli, and Staphylococcus aureus than those from the bulbs not treated with the polysaccharides. The research described here largely expands our current knowledge on the effects of gellan gum derivatives and has a huge practical potential in agriculture production.

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

    Science.gov (United States)

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

    2014-12-01

    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. 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. 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. These data suggest the potential of endophytic fungi of C. amboinicus as source for antimicrobial agents.

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

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    Puji Astuti

    2014-12-01

    Full Text Available 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.

  4. Synthesis of silver nanoparticles using Dioscorea bulbifera tuber extract and evaluation of its synergistic potential in combination with antimicrobial agents.

    Science.gov (United States)

    Ghosh, Sougata; Patil, Sumersing; Ahire, Mehul; Kitture, Rohini; Kale, Sangeeta; Pardesi, Karishma; Cameotra, Swaranjit S; Bellare, Jayesh; Dhavale, Dilip D; Jabgunde, Amit; Chopade, Balu A

    2012-01-01

    the synthesis of silver nanoparticles using D. bulbifera tuber extract followed by an estimation of its synergistic potential for enhancement of the antibacterial activity of broad spectrum antimicrobial agents.

  5. Neonatal nosocomial sepsis in a level-III NICU: evaluation of the causative agents and antimicrobial susceptibilities.

    Science.gov (United States)

    Yalaz, Mehmet; Cetin, Hasan; Akisu, Mete; Aydemir, Söhret; Tunger, Alper; Kültürsay, Nilgün

    2006-01-01

    Despite advances in supportive care and use of antibiotics, sepsis preserves its importance due to its high mortality and morbidity for neonates. Identifying the causative agents and antibiotic resistance yearly in a neonatal intensive care unit (NICU) helps the physician to choose the most appropriate empirical therapy. In this study we aimed to evaluate positive blood cultures and antibiotic susceptibilities of newborns with proven sepsis during the years 2000-2002 in our NICU. The charts of babies with sepsis were evaluated for clinical characteristics, positive cultures and antimicrobial susceptibilities, retrospectively. Although most of the admitted patients were premature (76.5%), the frequency of proven sepsis was quite low, at 9.1% among 909 newborns. Mortality rate in sepsis was 16%. The most commonly isolated micro-organisms were coagulase-negative staphylococci (CoNS) (31.3%), fungi (19.2%), Staphylococcus aureus (13%) and Klebsiella pneumoniae (10.5%). Methicillin resistance for CoNS was 92.3% and for S. aureus was 72.7%. In the last year, a significant increase in the frequency of Klebsiella pneumoniae (8.3 vs 14.2%), CoNS (27.1 vs 37.1%), Pseudomonas aeruginosa (2.1 vs 8.6%) and fungal infections (18.8 vs 20%) was observed compared to the previous years. An initial empirical antibiotic therapy for late-onset sepsis was designed with teicoplanin + piperacillin-tazobactam/meropenem + antifungal (fluconazole or amphotericin B) as the best combination to cover this spectrum until the culture results arrive. However, this combination is only compatible with our results and may not be applied in all units. Every unit must follow the bacterial spectrum and antibacterial resistance patterns to choose their specific empirical treatment strategy for nosocomial infections.

  6. Antimicrobial agent triclosan disrupts mitochondrial structure, revealed by super-resolution microscopy, and inhibits mast cell signaling via calcium modulation.

    Science.gov (United States)

    Weatherly, Lisa M; Nelson, Andrew J; Shim, Juyoung; Riitano, Abigail M; Gerson, Erik D; Hart, Andrew J; de Juan-Sanz, Jaime; Ryan, Timothy A; Sher, Roger; Hess, Samuel T; Gosse, Julie A

    2018-06-15

    The antimicrobial agent triclosan (TCS) is used in products such as toothpaste and surgical soaps and is readily absorbed into oral mucosa and human skin. These and many other tissues contain mast cells, which are involved in numerous physiologies and diseases. Mast cells release chemical mediators through a process termed degranulation, which is inhibited by TCS. Investigation into the underlying mechanisms led to the finding that TCS is a mitochondrial uncoupler at non-cytotoxic, low-micromolar doses in several cell types and live zebrafish. Our aim was to determine the mechanisms underlying TCS disruption of mitochondrial function and of mast cell signaling. We combined super-resolution (fluorescence photoactivation localization) microscopy and multiple fluorescence-based assays to detail triclosan's effects in living mast cells, fibroblasts, and primary human keratinocytes. TCS disrupts mitochondrial nanostructure, causing mitochondria to undergo fission and to form a toroidal, "donut" shape. TCS increases reactive oxygen species production, decreases mitochondrial membrane potential, and disrupts ER and mitochondrial Ca 2+ levels, processes that cause mitochondrial fission. TCS is 60 × more potent than the banned uncoupler 2,4-dinitrophenol. TCS inhibits mast cell degranulation by decreasing mitochondrial membrane potential, disrupting microtubule polymerization, and inhibiting mitochondrial translocation, which reduces Ca 2+ influx into the cell. Our findings provide mechanisms for both triclosan's inhibition of mast cell signaling and its universal disruption of mitochondria. These mechanisms provide partial explanations for triclosan's adverse effects on human reproduction, immunology, and development. This study is the first to utilize super-resolution microscopy in the field of toxicology. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Plants as sources of antiviral agents | Abonyi | African Journal of ...

    African Journals Online (AJOL)

    Antivirals are substances other than a virus or virus containing vaccine or specific antibody which can produce either a protective or therapeutic effect to the clear detectable advantage of the virus infected host. The search for antiviral agents began in earnest in the 1950s but this was directed mainly by chance, with little or ...

  8. Antimicrobial, Cytotoxicity and Phytochemical Screening of Jordanian Plants Used in Traditional Medicine

    Directory of Open Access Journals (Sweden)

    Adel M. Mahasneh

    2010-03-01

    Full Text Available Antimicrobial activity and cytotoxicity of fifty one extracts of different parts of 14 plants were studied. Ethanol, methanol, aqueous, butanol, and n-hexane extracts were tested against three Gram negative, two Gram positive bacteria, and two fungi. Cytotoxicity and phytochemical screening were determined using MTT and TLC assays, respectively. Of the fifty one extracts, twenty two showed activities against different microorganisms with MICs ranging from 62.5 to 1000 µg/mL. The highest activity (100% inhibition was for a butanol extract of Rosa damascena receptacles against Salmonella typhimurium and Bacillus cereus (MIC of 62.5 and 250 µg/mL respectively. Butanol extract of Narcissus tazetta aerial parts and aqueous extract of Rosa damascena receptacles were both active against Candida albicans (MIC of 125 µg/mL. Methicillin-resistant Staphylococcus aureus was inhibited by butanol, aqueous extracts of Rosa damascena receptacles and butanol extract of Inula viscosa flowers (MIC of 500, 500, and 250 µg/mL respectively. Rosa damascena receptacles and Verbascum sinaiticum flowers ethanol extract showed lowest cytoxicity against Vero cell line (IC50 of 454.11and 367.11. Most toxic was the ethanol extract of Ononis hirta aerial parts (IC50 72.50 µg/mL. Flavonoids and terpenoids were present in all plants. Ononis hirta and Narcissus tazetta contained alkaloids. The results validate the use of these plants and report for the first time bioactivity of Rosa damascena receptacles and further justifies the use of such screening programs in the quest for new drugs.

  9. Suitability of various plant derived gelling agents as agar substitute ...

    African Journals Online (AJOL)

    USER

    2012-06-05

    Jun 5, 2012 ... of three test fungi (Trichoderma harzianum, Alternaria alternata and Alternaria solani) as good as agar. ... used for cell culture, derived from plants or animals and .... and used to jell various foods, drugs and cosmetics) and rice.

  10. Insights into Comparative Antimicrobial Efficacies of Synthetic and Organic Agents: The Case of ZnS Nanoparticles and Zingiber officinale Rosc.

    Science.gov (United States)

    Obidi, O. F.; Nejo, A. O.; Ayeni, R. A.; Revaprasadu, N.

    2018-03-01

    The differences among the antimicrobial activities of synthetic nanoparticles (NPs), organic agents and conventional antibiotics against human pathogens are little known. We compared the antimicrobial activities of aqueous, ethanol and ethyl acetate extracts of Zingiber officinale rhizomes with ZnS NPs and tetracycline/nystatin using agar-diffusion techniques. Transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and ultraviolet spectroscopy were used to characterize ZnS NPs. At 100 mg/ml, ethanol and ethyl acetate extract inhibited Acinetobacter baumannii, Salmonella typhimurium, Enterococcus faecium, Shigella flexneri, Klebsiella pneumoniae, Staphylococcus epidermidis and Candida albicans with zones of inhibition (ZOI) ranging between 0-42 mm and 0-39 mm, respectively. Candida albicans had a remarkable ZOI of 42 mm and 22 mm from ethanol and ZnS NPs compared with 20 mm from conventional nystatin. TEM and FTIR revealed spherically shaped polydispersed NPs with particle size of 12.5 nm and the role of banana peel extracts in ZnS NPs synthesis. Organic and synthetic NPs proved potential alternatives to conventional antimicrobial agents.

  11. Insights into Comparative Antimicrobial Efficacies of Synthetic and Organic Agents: The Case of ZnS Nanoparticles and Zingiber officinale Rosc.

    Science.gov (United States)

    Obidi, O. F.; Nejo, A. O.; Ayeni, R. A.; Revaprasadu, N.

    2018-06-01

    The differences among the antimicrobial activities of synthetic nanoparticles (NPs), organic agents and conventional antibiotics against human pathogens are little known. We compared the antimicrobial activities of aqueous, ethanol and ethyl acetate extracts of Zingiber officinale rhizomes with ZnS NPs and tetracycline/nystatin using agar-diffusion techniques. Transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and ultraviolet spectroscopy were used to characterize ZnS NPs. At 100 mg/ml, ethanol and ethyl acetate extract inhibited Acinetobacter baumannii, Salmonella typhimurium, Enterococcus faecium, Shigella flexneri, Klebsiella pneumoniae, Staphylococcus epidermidis and Candida albicans with zones of inhibition (ZOI) ranging between 0-42 mm and 0-39 mm, respectively. Candida albicans had a remarkable ZOI of 42 mm and 22 mm from ethanol and ZnS NPs compared with 20 mm from conventional nystatin. TEM and FTIR revealed spherically shaped polydispersed NPs with particle size of 12.5 nm and the role of banana peel extracts in ZnS NPs synthesis. Organic and synthetic NPs proved potential alternatives to conventional antimicrobial agents.

  12. Alginate edible films containing microencapsulated lemongrass oil or citral: effect of encapsulating agent and storage time on physical and antimicrobial properties.

    Science.gov (United States)

    Alarcón-Moyano, Jessica K; Bustos, Rubén O; Herrera, María Lidia; Matiacevich, Silvia B

    2017-08-01

    Active edible films have been proposed as an alternative to extend shelf life of fresh foods. Most essential oils have antimicrobial properties; however, storage conditions could reduce their activity. To avoid this effect the essential oil (EO) can be microencapsulated prior to film casting. The aim of this study was to determine the effects of the type of encapsulating agent (EA), type of EO and storage time on physical properties and antimicrobial activity of alginate-based films against Escherichia coli ATCC 25922. Trehalose (TH), Capsul ® (CAP) and Tween 20 (Tw20) were used as EA. Lemongrass essential oil (LMO) and citral were used as active agents. The results showed that the type of EA affected the stability of the film forming-emulsions as well as the changes in opacity and colour of the films during storage but not the antimicrobial activity of them. Both microencapsulated EOs showed a prolonged release from the alginate films during the 28 days of storage. Trehalose was selected to encapsulate both active compounds because the films made with this microencapsulated EA showed the greatest physical stability and the lowest color variation among all the films studied.

  13. Adsorption of various antimicrobial agents to endotoxin removal polymyxin-B immobilized fiber (Toraymyxin®). Part 2: Adsorption of two drugs to Toraymyxin PMX-20R cartridges.

    Science.gov (United States)

    Shimokawa, Ken-ichi; Takakuwa, Ryotaro; Wada, Yuko; Yamazaki, Noriko; Ishii, Fumiyoshi

    2013-01-01

    In our previous study, the degree of adsorption of 9 representative antimicrobial agents to Toraymyxin(®) PMX-F sheets was quantitatively evaluated. As a result, the adsorption rate was 22.1% for Linezolid in the presence of serum. Therefore, we investigated whether two types of antimicrobial agents (Ciprofroxacin and Linezolid) can be better adsorbed on PMX-F sheets. When the number of PMX-F sheets was increased in a step wise manner, specifically 2, 4, 6, 8 and 12, the adsorption rate increased linearly. In addition, the adsorption to polymyxin-B immobilized fiber (Toraymyxin(®) PMX-20R) cartridges, widely used to remove endotoxins from circulating blood in the treatment of sepsis, was quantitatively evaluated. As a result, in the presence of serum, Linezolid showed adsorption to PMX-20R, and the adsorption rate after 2h was 54.5%, and that after 4h was 65.8%. The results of this study suggest the necessity of monitoring blood antimicrobial concentration during treatment for sepsis with Linezolid, which showed adsorption to PMX-20R in an environment close to a clinical environment. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Potential applications of plant based derivatives as fat replacers, antioxidants and antimicrobials in fresh and processed meat products.

    Science.gov (United States)

    Hygreeva, Desugari; Pandey, M C; Radhakrishna, K

    2014-09-01

    Growing concern about diet and health has led to development of healthier food products. In general consumer perception towards the intake of meat and meat products is unhealthy because it may increase the risk of diseases like cardiovascular diseases, obesity and cancer, because of its high fat content (especially saturated fat) and added synthetic antioxidants and antimicrobials. Addition of plant derivatives having antioxidant components including vitamins A, C and E, minerals, polyphenols, flavanoids and terpenoids in meat products may decrease the risk of several degenerative diseases. To change consumer attitudes towards meat consumption, the meat industry is undergoing major transformations by addition of nonmeat ingredients as animal fat replacers, natural antioxidants and antimicrobials, preferably derived from plant sources. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Expression and Purification of the Main Component Contained in Camel Milk and Its Antimicrobial Activities Against Bacterial Plant Pathogens.

    Science.gov (United States)

    Tanhaeian, Abbas; Shahriari Ahmadi, Farajollah; Sekhavati, Mohammad Hadi; Mamarabadi, Mojtaba

    2018-04-04

    Lactoferrin is the most dominant protein in milk after casein. This protein plays a crucial role in many biological processes including the regulation of iron metabolism, induction and modulation of the immune system, the primary defense against microorganisms, inhibiting lipid peroxidation and presenting antimicrobial activity against various pathogens such as parasites, fungi, bacteria, and viruses. The major antimicrobial effect of lactoferrin is related to its N-terminal tail where different peptides for instance lactoferricin and lactoferrampin which are important for their antimicrobial abilities are present. The growth rate of bacterial cells in camel milk is lower than that of the cow milk due to having more antimicrobial compounds. In this study, we have fused a codon-optimized partial camel lactoferrcin and lactoferrampin DNA sequences in order to construct a fused peptide via a lysine. This chimeric 42-mer peptide consists of complete and partial amino acid sequence of camel lactoferrampin and lactoferricin, respectively. Human embryonic kidney 293 (HEK-293) cells were used for synthesizing this recombinant peptide. Finally, the antibacterial activities of this constructed peptide were investigated under in vitro condition. The result showed that, all construction, cloning and expression processes were successfully performed in HEK-293. One His-tag tail was added to the chimera in order to optimize the isolation and purification processes and also reduce the cost of production. Additionally, His-tag retained the antimicrobial activity of the chimera. The antimicrobial tests showed that the growth rate in the majority of bacterial plant pathogens, including gram negative and positive bacteria, was inhibited by recombinant chimera as the level of MIC values were evaluated between 0.39 and 25.07 μg/ml for different bacterial isolates.

  16. Plant-Derived Agents for Counteracting Cisplatin-Induced Nephrotoxicity

    OpenAIRE

    Ojha, Shreesh; Venkataraman, Balaji; Kurdi, Amani; Mahgoub, Eglal; Sadek, Bassem; Rajesh, Mohanraj

    2016-01-01

    Cisplatin (CSP) is a chemotherapeutic agent commonly used to treat a variety of malignancies. The major setback with CSP treatment is that its clinical efficacy is compromised by its induction of organ toxicity, particular to the kidneys and ears. Despite the significant strides that have been made in understanding the mechanisms underlying CSP-induced renal toxicity, advances in developing renoprotective strategies are still lacking. In addition, the renoprotective approaches described in th...

  17. Remediation of toxic ad hazardous wastes: plants as biological agents to mitigate heavy metal pollution

    International Nuclear Information System (INIS)

    Cadiz, Nina M.; Principe, Eduardo B.

    2005-01-01

    This papers introduced the plants as biological agents to control heavy metal pollution and the process used the green plants to clean contaminated soils or to render the toxic ions harmless is a new technology called phytoremediation with two levels, the phytostabilization and phytoextraction

  18. Chemical composition and antimicrobial activity of the essential oil from the edible aromatic plant Aristolochia delavayi.

    Science.gov (United States)

    Li, Zhi-Jian; Njateng, Guy S S; He, Wen-Jia; Zhang, Hong-Xia; Gu, Jian-Long; Chen, Shan-Na; Du, Zhi-Zhi

    2013-11-01

    The essential oil obtained by hydrodistillation from the aerial parts of Aristolochia delavayi Franch. (Aristolochiaceae), a unique edible aromatic plant consumed by the Nakhi (Naxi) people in Yunnan, China, was investigated using GC/MS analysis. In total, 95 components, representing more than 95% of the oil composition, were identified, and the main constituents found were (E)-dec-2-enal (52.0%), (E)-dodec-2-enal (6.8%), dodecanal (3.35%), heptanal (2.88%), and decanal (2.63%). The essential oil showed strong inhibitory activity (96% reduction) of the production of bacterial volatile sulfide compounds (VSC) by Klebsiella pneumoniae, an effect that was comparable with that of the reference compound citral (91% reduction). Moreover, the antimicrobial activity of the essential oil and the isolated major compound against eight bacterial and six fungal strains were evaluated. The essential oil showed significant antibacterial activity against Providencia stuartii and Escherichia coli, with minimal inhibitory concentrations (MIC) ranging from 3.9 to 62.5 μg/ml. The oil also showed strong inhibitory activity against the fungal strains Trichophyton ajelloi, Trichophyton terrestre, Candida glabrata, Candida guilliermondii, and Cryptococcus neoformans, with MIC values ranging from 3.9 to 31.25 μg/ml, while (E)-dec-2-enal presented a lower antifungal activity than the essential oil. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  19. General principles of antimicrobial therapy.

    Science.gov (United States)

    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.

  20. Transgenic Brassica juncea plants expressing MsrA1, a synthetic cationic antimicrobial peptide, exhibit resistance to fungal phytopathogens.

    Science.gov (United States)

    Rustagi, Anjana; Kumar, Deepak; Shekhar, Shashi; Yusuf, Mohd Aslam; Misra, Santosh; Sarin, Neera Bhalla

    2014-06-01

    Cationic antimicrobial peptides (CAPs) have shown potential against broad spectrum of phytopathogens. Synthetic versions with desirable properties have been modeled on these natural peptides. MsrA1 is a synthetic chimera of cecropin A and melittin CAPs with antimicrobial properties. We generated transgenic Brassica juncea plants expressing the msrA1 gene aimed at conferring fungal resistance. Five independent transgenic lines were evaluated for resistance to Alternaria brassicae and Sclerotinia sclerotiorum, two of the most devastating pathogens of B. juncea crops. In vitro assays showed inhibition by MsrA1 of Alternaria hyphae growth by 44-62 %. As assessed by the number and size of lesions and time taken for complete leaf necrosis, the Alternaria infection was delayed and restricted in the transgenic plants with the protection varying from 69 to 85 % in different transgenic lines. In case of S. sclerotiorum infection, the lesions were more severe and spread profusely in untransformed control compared with transgenic plants. The sclerotia formed in the stem of untransformed control plants were significantly more in number and larger in size than those present in the transgenic plants where disease protection of 56-71.5 % was obtained. We discuss the potential of engineering broad spectrum biotic stress tolerance by transgenic expression of CAPs in crop plants.

  1. Prophylaxis of post-ERC infectious complications in patients with biliary obstruction by adding antimicrobial agents into ERC contrast media- a single center retrospective study.

    Science.gov (United States)

    Wobser, Hella; Gunesch, Agnetha; Klebl, Frank

    2017-01-13

    Patients with biliary obstruction are at high risk to develop septic complications after endoscopic retrograde cholangiography (ERC). We evaluated the benefits of local application of antimicrobial agents into ERC contrast media in preventing post-ERC infectious complications in a high-risk study population. Patients undergoing ERC at our tertiary referral center were retrospectively included. Addition of vancomycin, gentamicin and fluconazol into ERC contrast media was evaluated in a case-control design. Outcomes comprised infectious complications within 3 days after ERC. In total, 84 ERC cases were analyzed. Primarily indications for ERC were sclerosing cholangitis (75%) and malignant stenosis (9.5%). Microbial testing of collected bile fluid in the treatment group was positive in 91.4%. Detected organisms were sensitive to the administered antimicrobials in 93%. The use of antimicrobials in contrast media was associated with a significant decrease in post-ERC infectious complications compared to non-use (14.3% vs. 33.3%; odds ratio [OR]: 0.33, 95% confidence interval [CI]: 0.114-0.978). After adjusting for the variables acute cholangitis prior to ERC and incomplete biliary drainage, the beneficial effect of intraductal antibiotic prophylaxis was even more evident (OR = 0.153; 95% CI: 0.039-0.598, p = 0.007). Patients profiting most obviously from intraductal antimicrobials were those with secondary sclerosing cholangitis. Local application of a combination of antibiotic and antimycotic agents to ERC contrast media efficiently reduced post-ERC infectious events in patients with biliary obstruction. This is the first study that evaluates ERC-related infectious complications in patients with secondary sclerosing cholangitis. Our first clinical results should now be prospectively evaluated in a larger patient cohort to improve the safety of ERC, especially in patients with secondary sclerosing cholangitis.

  2. Evaluation of antimicrobial activity of silver nanoparticles synthesized from Piper betle leaves against human and plant pathogens

    Science.gov (United States)

    Jha, Babita; Rao, Mugdha; Prasad, K.; Jha, Anal K.

    2018-05-01

    The present work encompasses the fabrication of biocompatible silver nanoparticles from the leaves of the medicinal plant Piper betle using green chemistry approach. The synthesized nanoparticles were characterized by different standard techniques like: UV-visible spectroscopy, X-ray diffraction, scanning electron microscopy and Fourier transformed infrared spectroscopy. The antimicrobial efficacy of the silver nanoparticles was assessed against human and plant pathogens namely Ralstonia solanacearum, Burkholderia gladioli, Escherichia coli and Sacchromyces cerevisiae by agar well diffusion method. The obtained results clearly indicate its possible use as an alternative to antibiotics and pesticides in near future.

  3. Chromatographic analysis of natural pigments L. and quercus infectoria oliv: produced from datisca cannabina plants and their antimicrobial activity

    International Nuclear Information System (INIS)

    Deveoglu, O.; Muhammed, A.; Fouad, A.; Torgan, E.; Karadag, R.

    2012-01-01

    In this study, natural pigments from the hemp (Datisca cannabina L.) and dyer's oak ). 12H/sub 2/O (alum) mordant. A (Quercus infectoria Oliv.) dye plants were prepared by using KAl(SO/sub 4)/sub 2/ reversed-phase high performance liquid chromatography (RP-HPLC) with diode array detection (DAD) method was used in the identification of dyes in the natural pigments. The dye extractions from the natural pigments were carried out with 37% HCl/MeOH/H/sub 2/O (2:1:1 v/v/v) mixture. Also, antimicrobial activity of crude extracts of plants and pigments were investigated. (author)

  4. Multicenter Study in Taiwan of the In Vitro Activities of Nemonoxacin, Tigecycline, Doripenem, and Other Antimicrobial Agents against Clinical Isolates of Various Nocardia Species▿

    Science.gov (United States)

    Lai, Chih-Cheng; Liu, Wei-Lun; Ko, Wen-Chien; Chen, Yen-Hsu; Tan, Hon-Ren; Huang, Yu-Tsung; Hsueh, Po-Ren

    2011-01-01

    The aim of this study was to assess the in vitro activities of nemonoxacin (a novel nonfluorinated quinolone), doripenem, tigecycline, and 16 other antimicrobial agents against Nocardia species. The MICs of the 19 agents against 151 clinical isolates of Nocardia species were determined by the broth microdilution method. The isolates were identified to the species level using 16S rRNA gene sequencing analysis. The results showed that N. brasiliensis (n = 60; 40%) was the most common species, followed by N. cyriacigeorgica (n = 24; 16%), N. farcinica (n = 12; 8%), N. beijingensis (n = 9), N. otitidiscaviarum (n = 8), N. nova (n = 8), N. asiatica (n = 7), N. puris (n = 6), N. flavorosea (n = 5), N. abscessus (n = 3), N. carnea (2), and one each of N. alba, N. asteroides complex, N. rhamnosiphila, N. elegans, N. jinanensis, N. takedensis, and N. transvalensis. The MIC90s of the tested quinolones against the N. brasiliensis isolates were in the order nemonoxacin = gemifloxacin Nocardia isolates. Among the four tested carbapenems, imipenem had the lowest MIC90s. All of the clinical isolates of N. beijingensis, N. otitidiscaviarum, N. nova, and N. puris and more than half of the N. brasiliensis and N. cyriacigeorgica isolates were resistant to at least one antimicrobial agent. The results of this in vitro study suggest that nemonoxacin, linezolid, and tigecycline are promising treatment options for nocardiosis. Further investigation of their clinical role is warranted. PMID:21343461

  5. Multicenter study in Taiwan of the in vitro activities of nemonoxacin, tigecycline, doripenem, and other antimicrobial agents against clinical isolates of various Nocardia species.

    Science.gov (United States)

    Lai, Chih-Cheng; Liu, Wei-Lun; Ko, Wen-Chien; Chen, Yen-Hsu; Tan, Hon-Ren; Huang, Yu-Tsung; Hsueh, Po-Ren

    2011-05-01

    The aim of this study was to assess the in vitro activities of nemonoxacin (a novel nonfluorinated quinolone), doripenem, tigecycline, and 16 other antimicrobial agents against Nocardia species. The MICs of the 19 agents against 151 clinical isolates of Nocardia species were determined by the broth microdilution method. The isolates were identified to the species level using 16S rRNA gene sequencing analysis. The results showed that N. brasiliensis (n=60; 40%) was the most common species, followed by N. cyriacigeorgica (n=24; 16%), N. farcinica (n=12; 8%), N. beijingensis (n=9), N. otitidiscaviarum (n=8), N. nova (n=8), N. asiatica (n=7), N. puris (n=6), N. flavorosea (n=5), N. abscessus (n=3), N. carnea (2), and one each of N. alba, N. asteroides complex, N. rhamnosiphila, N. elegans, N. jinanensis, N. takedensis, and N. transvalensis. The MIC90s of the tested quinolones against the N. brasiliensis isolates were in the order nemonoxacin=gemifloxacinNocardia isolates. Among the four tested carbapenems, imipenem had the lowest MIC90s. All of the clinical isolates of N. beijingensis, N. otitidiscaviarum, N. nova, and N. puris and more than half of the N. brasiliensis and N. cyriacigeorgica isolates were resistant to at least one antimicrobial agent. The results of this in vitro study suggest that nemonoxacin, linezolid, and tigecycline are promising treatment options for nocardiosis. Further investigation of their clinical role is warranted.

  6. Antimicrobial activities of some Thai traditional medical longevity formulations from plants and antibacterial compounds from Ficus foveolata.

    Science.gov (United States)

    Meerungrueang, W; Panichayupakaranant, P

    2014-09-01

    Medicinal plants involved in traditional Thai longevity formulations are potential sources of antimicrobial compounds. To evaluate the antimicrobial activities of some extracts from medicinal plants used in traditional Thai longevity formulations against some oral pathogens, including Streptococcus pyogenes, Streptococcus mitis, Streptococcus mutans, and Candida albicans. An extract that possessed the strongest antimicrobial activity was fractionated to isolate and identify the active compounds. Methanol and ethyl acetate extracts of 25 medicinal plants used as Thai longevity formulations were evaluated for their antimicrobial activity using disc diffusion (5 mg/disc) and broth microdilution (1.2-2500 µg/mL) methods. The ethyl acetate extract of Ficus foveolata Wall. (Moraceae) stems that exhibited the strongest antibacterial activity was fractionated to isolate the active compounds by an antibacterial assay-guided isolation process. The ethyl acetate extract of F. foveolata showed the strongest antibacterial activity with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 19.5-39.0 and 39.0-156.2 µg/mL, respectively. On the basis of an antibacterial assay-guided isolation, seven antibacterial compounds, including 2,6-dimethoxy-1,4-benzoquinone (1), syringaldehyde (2), sinapaldehyde (3), coniferaldehyde (4), 3β-hydroxystigmast-5-en-7-one (5), umbelliferone (6), and scopoletin (7), were purified. Among these isolated compounds, 2,6-dimethoxy-1,4-benzoquinone (1) exhibited the strongest antibacterial activities against S. pyogenes, S. mitis, and S. mutans with MIC values of 7.8, 7.8, and 15.6 µg/mL, and MBC values of 7.8, 7.8, and 31.2 µg/mL, respectively. In addition, this is the first report of these antibacterial compounds in the stems of F. foveolata.

  7. Removal of Pb, Zn, and Cd from contaminated soil by new washing agent from plant material.

    Science.gov (United States)

    Cao, Yaru; Zhang, Shirong; Wang, Guiyin; Huang, Qinling; Li, Ting; Xu, Xiaoxun

    2017-03-01

    Soil washing is an effective approach to remove soil heavy metals, and the washing agent is generally regarded as one of the primary factors in the process, but there is still a lack of efficient and eco-friendly agents for this technique. Here, we showed that four plant washing agents-from water extracts of Coriaria nepalensis (CN), Clematis brevicaudata (CB), Pistacia weinmannifolia (PW), and Ricinus communis (RC)-could be feasible agents for the removal of soil lead (Pb), zinc (Zn), and cadmium (Cd). The metal removal efficiencies of the agents increased with their concentrations from 20 to 80 g L -1 , decreased with the increasing solution pH, and presented different trends with the reaction time increasing. CN among the four agents had the highest removal efficiencies of soil Pb (62.02%) and Zn (29.18%) but owned the relatively low Cd removal efficiencies (21.59%). The Fourier transform infrared spectroscopy showed that the abilities of plant washing agents for the removal of soil heavy metals may result from bioactive substances with specific functional groups such as -COOH, -NH 2 , and -OH. Our study provided CN as the best washing agents for the remediation of contaminated soil by heavy metals.

  8. Comparrisson of MICs of ceftioufur and other antimicrobial agents against bacterial pathogens of swine from the United States, Canada and Denmark

    DEFF Research Database (Denmark)

    Salmon, S.A.; Watts, J.L.; Case, C.A.

    1995-01-01

    , sulfamethazine, trimethoprim-sulfadiazine (1:19), erythromycin, lincomycin, spectinomycin, lincomycin-spectinomycin (1:8), tilmicosin, and tetracycline. Tilmicosin was only tested against the U.S. isolates. Overall, ceftiofur and enrofloxacin were the most active antimicrobial agents tested against all isolates.......0 and 8.0 mu g/ml, respectively). However, this compound was not active against the remaining U.S. isolates (MIC(90)s, >64.0 mu g/ml), Differences in the MICs from one country to another were not detected with enrofloxacin, ceftiofur, or lincomycin for the strains tested, but variations in the MICs...

  9. Distribution of phylogroups and co-resistance to antimicrobial agents in ampicillin resistant Escherichia coli isolated from healthy humans and from patients with bacteraemia

    DEFF Research Database (Denmark)

    Haugaard, A.; Hammerum, A. M.; Porsbo, Lone Jannok

    inhibitory concentration to antimicrobial agents and examined by PCR to determine their phylogroups. The phylotyping grouped the faecal samples into A (13%), B1 (10%), B2 (42%), D (19%), NT (16%) while the blood isolates grouped into A (16%), B1 (0%), B2 (48%), D (32%) and NT (3%). The frequency...... of resistance in faecal and blood isolates (F/B) was: tetracycline (48%/48%), gentamicin (0%/10%), ciprofloxacin (3%,13%), sulfonamide (68%/77%) and trimethoprim (39%/39%). Conclusion: B2 was the most prevalent phylogroup found both in faecal isolates collected from healthy humans and in blood isolates from...

  10. Interscience Conference on Antimicrobial Agents and Chemotherapy--49th annual meeting. Part 2. 12-15 September 2009, San Francisco, CA, USA.

    Science.gov (United States)

    Turner, Ben; Murch, Lisa

    2009-11-01

    The Interscience Conference on Antimicrobial Agents and Chemotherapy held in San Francisco included topics covering new therapeutic developments for the treatment of infectious diseases. This conference report highlights selected presentations on several antibiotics in development including a broad-spectrum penem beta-lactam antibiotic, a novel siderophore monobactam, as well as other novel antibiotics. Investigational drugs discussed include sulopenem and sulopenem etzadroxil (both Pfizer Inc), BAL-30072 (Basilea Pharmaceutica International Ltd), TP-120 and TP-787 (both Tetraphase Pharmaceuticals Inc), NAI-107 (New Anti Infectives Consortium/NexThera Biosciences) and ABI-200 (AdRem Biotech/US Department of Agriculture).

  11. Studies of the in vitro anticancer, antimicrobial and antioxidant potentials of selected Yemeni medicinal plants from the island Soqotra

    Science.gov (United States)

    2009-01-01

    Background Recent years have witnessed that there is a revival of interest in drug discovery from medicinal plants for the maintenance of health in all parts of the world. The aim of this work was to investigate 26 plants belonging to 17 families collected from a unique place in Yemen (Soqotra Island) for their in vitro anticancer, antimicrobial and antioxidant activities. Methods The 26 plants were extracted with methanol and hot water to yield 52 extracts. Evaluation for in vitro anticancer activity was done against three human cancer cell lines (A-427, 5637 and MCF-7) by using an established microtiter plate assay based on cellular staining with crystal violet. Antimicrobial activity was tested against three Gram-positive bacteria, two Gram-negative bacteria, one yeast species and three multiresistant Staphylococcus strains by using an agar diffusion method and the determination of MIC against three Gram-positive bacteria with the broth micro-dilution assay. Antioxidant activity was investigated by measuring the scavenging activity of the DPPH radical. Moreover, a phytochemical screening of the methanolic extracts was done. Results Notable cancer cell growth inhibition was observed for extracts from Ballochia atro-virgata, Eureiandra balfourii and Hypoestes pubescens, with IC50 values ranging between 0.8 and 8.2 μg/ml. The methanol extracts of Acanthospermum hispidum, Boswellia dioscorides, Boswellia socotrana, Commiphora ornifolia and Euphorbia socotrana also showed noticeable antiproliferative potency with IC50 values 15 mm and MIC values ≤ 250 μg/ml. In addition, the methanolic extracts of Acacia pennivenia, Boswellia dioscorides, Boswellia socotrana and Commiphora ornifolia showed good antioxidant potential at low concentrations (more than 80% at 50 μg/ml). Conclusion Our results show once again that medicinal plants can be promising sources of natural products with potential anticancer, antimicrobial and antioxidative activity. The results will guide

  12. Phytochemical and antimicrobial study of an antidiabetic plant: Scoparia dulcis L.

    Science.gov (United States)

    Latha, M; Ramkumar, K M; Pari, L; Damodaran, P N; Rajeshkannan, V; Suresh, T

    2006-01-01

    The antimicrobial and antifungal effects of different concentrations of chloroform/methanol fractions of Scoparia dulcis were investigated. The isolated fractions were tested against different bacteria like Salmonella typhii, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Proteus vulgaris and fungal strains such as Alternaria macrospora, Candida albicans, Aspergillus niger, and Fusarium oxysporum. The isolated fractions exhibited significant antimicrobial and antifungal activity against all the tested organisms compared with respective reference drugs. The isolated fractions of S. dulcis showed properties like antimicrobial and antifungal activities that will enable researchers in turn to look for application-oriented principles.

  13. Anti-phytopathogen potential of endophytic actinobacteria isolated from tomato plants (Lycopersicon esculentum) in southern Brazil, and characterization of Streptomyces sp. R18(6), a potential biocontrol agent.

    Science.gov (United States)

    de Oliveira, Margaroni Fialho; da Silva, Mariana Germano; Van Der Sand, Sueli T

    2010-09-01

    Tomato plants (Lycopersicon esculentum) are highly susceptible to phytopathogen attack. The resulting intensive application of pesticides on tomato crops can affect the environment and health of humans and animals. The objective of this study was to select potential biocontrol agents among actinobacteria from tomato plants, in a search for alternative phytopathogen control. We evaluated 70 endophytic actinobacteria isolated from tomato plants in southern Brazil, testing their antimicrobial activity, siderophore production, indoleacetic acid production, and phosphate solubility. The actinomycete isolate with the highest antimicrobial potential was selected using the agar-well diffusion method, in order to optimize conditions for the production of compounds with antimicrobial activity. For this study, six growth media (starch casein-SC, ISP2, Bennett's, Sahin, Czapek-Dox, and TSB), three temperatures (25 degrees C, 30 degrees C, and 35 degrees C) and different pH were tested. Of the actinobacteria tested, 88.6% showed antimicrobial activity against at least one phytopathogen, 72.1% showed a positive reaction for indoleacetic acid production, 86.8% produced siderophores and 16.2% showed a positive reaction for phosphate solubility. Isolate R18(6) was selected due to its antagonistic activity against all phytopathogenic microorganisms tested in this study. The best conditions for production were observed in the SC medium, at 30 degrees C and pH 7.0. The isolate R18(6) showed close biochemical and genetic similarity to Streptomyces pluricolorescens. Copyright 2010 Elsevier Masson SAS. All rights reserved.

  14. [Measurement of chemical agents in metallurgy field: electric steel plant].

    Science.gov (United States)

    Cottica, D; Grignani, E; Ghitti, R; Festa, D; Apostoli, P

    2012-01-01

    The steel industry maintains its important position in the context of the Italian production involving thousands of workers. The iron and steel processes are divided into primary steel industry, production of intermediate minerals, and secondary steel, scrap from the production of semi-finished industrial and consumer sector (metal inserted into components and metal used for dissipative uses, primarily coatings) and industrial waste. The paper presents the results of environmental monitoring carried out in some electric steel plant for the measurement of airborne chemicals that characterize the occupational exposure of workers employed in particular area like electric oven, to treatment outside the furnace, continuous casting area. For the sampling of the pollutants were used both personal and in fixed positions samplers. The pollutants measured are those typical of steel processes inhalable dust, metals, respirable dust, crystalline silica, but also Polycyclic Aromatic Hydrocarbons (PAH), polychlorinated dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).

  15. [Expression of plant antimicrobial peptide pro-SmAMP2 gene increases resistance of transgenic potato plants to Alternaria and Fusarium pathogens].

    Science.gov (United States)

    Vetchinkina, E M; Komakhina, V V; Vysotskii, D A; Zaitsev, D V; Smirnov, A N; Babakov, A V; Komakhin, R A

    2016-09-01

    The chickweed (Stellaria media L.) pro-SmAMP2 gene encodes the hevein-like peptides that have in vitro antimicrobial activity against certain harmful microorganisms. These peptides play an important role in protecting the chickweed plants from infection, and the pro-SmAMP2 gene was previously used to protect transgenic tobacco and Arabidopsis plants from phytopathogens. In this study, the pro-SmAMP2 gene under control of viral CaMV35S promoter or under control of its own pro-SmAMP2 promoter was transformed into cultivated potato plants of two cultivars, differing in the resistance to Alternaria: Yubiley Zhukova (resistant) and Skoroplodny (susceptible). With the help of quantitative real-time PCR, it was demonstrated that transgenic potato plants expressed the pro-SmAMP2 gene under control of both promoters at the level comparable to or exceeding the level of the potato actin gene. Assessment of the immune status of the transformants demonstrated that expression of antimicrobial peptide pro-SmAMP2 gene was able to increase the resistance to a complex of Alternaria sp. and Fusarium sp. phytopathogens only in potato plants of the Yubiley Zhukova cultivar. The possible role of the pro-SmAMP2 products in protecting potatoes from Alternaria sp. and Fusarium sp. is discussed.

  16. Effects of subinhibitory concentrations of antimicrobial agents on Escherichia coli O157:H7 Shiga toxin release and role of the SOS response.

    Science.gov (United States)

    Nassar, Farah J; Rahal, Elias A; Sabra, Ahmad; Matar, Ghassan M

    2013-09-01

    Treatment of Escherichia coli O157:H7 by certain antimicrobial agents often exacerbates the patient's condition by increasing either the release of preformed Shiga toxins (Stx) upon cell lysis or their production through the SOS response-triggered induction of Stx-producing prophages. Recommended subinhibitory concentrations (sub-MICs) of azithromycin (AZI), gentamicin (GEN), imipenem (IMI), and rifampicin (RIF) were evaluated in comparison to norfloxacin (NOR), an SOS-inducer, to assess the role of the SOS response in Stx release. Relative expression of recA (SOS-inducer), Q (late antitermination gene of Stx-producing prophage), stx1, and stx2 genes was assessed at two sub-MICs of the antimicrobials for two different strains of E. coli O157:H7 using reverse transcription-real-time polymerase chain reaction. Both strains at the two sub-MICs were also subjected to Western blotting for LexA protein expression and to reverse passive latex agglutination for Stx detection. For both strains at both sub-MICs, NOR and AZI caused SOS-induced Stx production (high recA, Q, and stx2 gene expression and high Stx2 production), so they should be avoided in E. coli O157:H7 treatment; however, sub-MICs of RIF and IMI induced Stx2 production in an SOS-independent manner except for one strain at the first twofold dilution below MIC of RIF where Stx2 production decreased. Moreover, GEN caused somewhat increased Stx2 production due to its mode of action rather than any effect on gene expression. The choice of antimicrobial therapy should rely on the antimicrobial mode of action, its concentration, and on the nature of the strain.

  17. Potential New Pharmacological Agents Derived From Medicinal Plants for the Treatment of Pancreatic Cancer.

    Science.gov (United States)

    Azimi, Haniye; Khakshur, Ali Asghar; Abdollahi, Mohammad; Rahimi, Roja

    2015-01-01

    In the present article, we reviewed plants and phytochemical compounds demonstrating beneficial effects in pancreatic cancer to find new sources of pharmaceutical agents. For this purpose, Scopus, PubMed, Web of Science, and Google scholar were searched for plants or herbal components with beneficial effects in the treatment of pancreatic cancer. Data were collected up to January 2013. The search terms were "plant," "herb," "herbal therapy," or "phytotherapy" and "pancreatic cancer" or "pancreas." All of the human in vivo and in vitro studies were included. According to studies, among diverse plants and phytochemicals, 12 compounds including apigenin, genistein, quercetin, resveratrol, epigallocatechin gallate, benzyl isothiocyanate, sulforaphane, curcumin, thymoquinone, dihydroartemisinin, cucurbitacin B, and perillyl alcohol have beneficial action against pancreatic cancer cells through 4 or more mechanisms. Applying their plausible synergistic effects can be an imperative approach for finding new efficient pharmacological agents in the treatment of pancreatic cancer.

  18. NethMap 2017: Consumption of antimicrobial agents and antimicrobial resistance among medically important bacteria in the Netherlands / MARAN 2017: Monitoring of antimicrobial resistance and antibiotic usage in animals in the Netherlands in 2016

    NARCIS (Netherlands)

    de Greeff SC; Mouton JW; ZIA; I&V

    2017-01-01

    The number of bacteria that are resistant to antimicrobials is increasing worldwide. In the Netherlands, the number of resistant bacteria that can cause infections in humans has remained broadly stable. Nevertheless there is cause for concern and caution. Compared to 2015, in 2016 more 'outbreaks'

  19. Total Phenolic, Flavonoid, Tomatine, and Tomatidine Contents and Antioxidant and Antimicrobial Activities of Extracts of Tomato Plant

    Science.gov (United States)

    Silva-Beltrán, Norma Patricia; Ruiz-Cruz, Saul; Cira-Chávez, Luis Alberto; Estrada-Alvarado, María Isabel; Ornelas-Paz, José de Jesús; López-Mata, Marco Antonio; Del-Toro-Sánchez, Carmen Lizette; Ayala-Zavala, J. Fernando; Márquez-Ríos, Enrique

    2015-01-01

    The purpose of this study was to evaluate the antioxidant and antimicrobial properties of extracts of different fractions of two tomato plant cultivars. The stems, roots, leaves, and whole-plant fractions were evaluated. Tomatine and tomatidine were identified by HPLC-DAD. The leaf extracts from the two varieties showed the highest flavonoids, chlorophyll, carotenoids, and total phenolics contents and the highest antioxidant activity determined by DPPH, ABTS, and ORAC. A positive correlation was observed between the antioxidant capacities of the extracts and the total phenolic, flavonoid, and chlorophyll contents. The Pitenza variety extracts inhibited the growth of pathogens such as E. coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, and Listeria ivanovii, yielding inhibition halos of 8.0 to 12.9 mm in diameter and MIC values of 12.5 to 3.125 mg/mL. These results suggest that tomato plant shows well potential as sources of various bioactive compounds, antioxidants, and antimicrobials. PMID:26609308

  20. Synergism in mutations induction in Tradescantia by plants protection agents acting jointly with ionizing radiation

    International Nuclear Information System (INIS)

    Cebulska-Wasilewska, A.; Smagala, J.

    1990-01-01

    Tradescantia was first treated by plants protection agents such as: Ambusz, Afalton, Ripcord, Decis, deltametryne and after that irradiated with X radiation. The synergism of both factors was observed. The mutation frequency dependence on radiation doses was studied. 7 figs., 4 refs. (A.S.)

  1. Effects of biological control agents and exotic plant invasion on deer mouse populations

    Science.gov (United States)

    Yvette K. Ortega; Dean E. Pearson; Kevin S. McKelvey

    2004-01-01

    Exotic insects are commonly introduced as biological control agents to reduce densities of invasive exotic plants. Although current biocontrol programs for weeds take precautions to minimize ecological risks, little attention is paid to the potential nontarget effects of introduced food subsidies on native consumers. Previous research demonstrated that two gall flies (...

  2. Antimicrobial activity of ceftaroline and other anti-infective agents against microbial pathogens recovered from the surgical intensive care patient population: a prevalence analysis.

    Science.gov (United States)

    Edmiston, Charles E; Krepel, Candace J; Leaper, David; Ledeboer, Nathan A; Mackey, Tami-Lea; Graham, Mary Beth; Lee, Cheong; Rossi, Peter J; Brown, Kellie R; Lewis, Brian D; Seabrook, Gary R

    2014-12-01

    Ceftaroline is a new parenteral cephalosporin agent with excellent activity against methicillin-sensitive (MSSA) and resistant strains of Staphylococcus aureus (MRSA). Critically ill surgical patients are susceptible to infection, often by multi-drug-resistant pathogens. The activity of ceftaroline against such pathogens has not been described. Three hundred thirty-five consecutive microbial isolates were collected from surgical wounds or abscesses, respiratory, urine, and blood cultures from patients in the surgical intensive care unit (SICU) of a major tertiary medical center. Using Clinical and Laboratory Standards Institute (CLSI) standard methodology and published breakpoints, all aerobic, facultative anaerobic isolates were tested against ceftaroline and selected comparative antimicrobial agents. All staphylococcal isolates were susceptible to ceftaroline at a breakpoint of ≤1.0 mcg/mL. In addition, ceftaroline exhibited excellent activity against all streptococcal clinical isolates and non-ESBL-producing strains of Enterobacteriaceae (93.5%) recovered from SICU patients. Ceftaroline was inactive against ESBL-producing Enterobacteriaceae, Pseudomonas aeruginosa, vancomycin-resistant enterococci, and selective gram-negative anaerobic bacteria. At present, ceftaroline is the only cephalosporin agent that is active against community and healthcare-associated MRSA. Further studies are needed to validate the benefit of this novel broad-spectrum anti-infective agent for the treatment of susceptible serious infections in the SICU patient population.

  3. EFFECT OF SILVER NANOPARTICLES ON THE PHYSICAL AND CHEMICAL PROPERTIES OF PLANT OILS AND THEIR ANTIMICROBIAL ACTIVITY

    Directory of Open Access Journals (Sweden)

    V. M. Minarchenko

    2017-12-01

    Full Text Available The aim of our research was to investigate the influence of silver nanoparticles on the physical and chemical features of plant oils of dogrose, flax, cedar, amaranth and watermelon and their antimicrobial activity. Plant oils were saturated with silver nanoparticles using electron-beam technology for depositing a molecular stream of metal in a vacuum. To characterize the rancidity of plant oils, the acid, iodine, peroxide, ester and saponification values were determined. A sharp drop in the iodine number and an increase in the peroxide number in oils saturated with silver nanoparticles were observed, as compared to pure oils, indicating a decrease in the number of unsaturated bonds in fatty acids and the formation of peroxides in oils. All pure plant oils and a separate sample of silver nanoparticles suppressed the growth of only E. faecalis colonies. Plant oils that were saturated with silver nanoparticles delayed the growth of S. aureus, S. epidermidis, E. faecalis, E. coli, P. aeruginosa, and C. albicans; the greatest delay in the growth of colonies was caused by flaxseed oil. Thus, the features of the plant oils under study essentially changed after they are aturated with silver nanoparticles. It can be assumed that the metal acted as a catalyst for peroxide oxidation of lipids in the investigated plant oil samples, the products of which caused toxic effects on cultures of bacteria and fungi in the experiment.

  4. Demand Response Integration Through Agent-Based Coordination of Consumers in Virtual Power Plants

    DEFF Research Database (Denmark)

    Clausen, Anders; Umair, Aisha; Ma, Zheng

    2016-01-01

    of industrial loads. Coordination happens in response to Demand Response events, while considering local objectives in the industrial domain. We illustrate the applicability of our approach on a Virtual Power Plant scenario with three simulated greenhouses. The results suggest that the proposed design is able...... Power Plant design that is able to balance the demand of energy-intensive, industrial loads with the supply situation in the electricity grid. The proposed Virtual Power Plant design uses a novel inter-agent, multi-objective, multi-issue negotiation mechanism, to coordinate the electricity demands...... to coordinate the electricity demands of industrial loads, in compliance with external Demand Response events....

  5. Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    K. Al-Mughrabi

    2003-12-01

    Full Text Available Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. stolonifer. The weakest effect was against A. solani. Extracts from the stems had a stronger inhibitory effect than those from the flowers or leaves. Butanol was the best solvent to extract antimicrobial compounds from leaves, stems and flowers and was superior to chloroform, water and petroleum ether. Results clearly indicate that E. macroclada is a promising source of antimicrobial compounds.

  6. Synthesis of coumarin-theophylline hybrids as a new class of anti-tubercular and anti-microbial agents.

    Science.gov (United States)

    Mangasuli, Sumitra N; Hosamani, Kallappa M; Devarajegowda, Hirihalli C; Kurjogi, Mahantesh M; Joshi, Shrinivas D

    2018-02-25

    A series of novel coumarin-theophylline hybrids were synthesized and examined for their anti-tubercular activity in vitro against Mycobacterium tuberculosis H 37 Rv, anti-microbial activity in vitro against gram-positive bacteria (Staphylococcus aureus) and gram-negative bacterias (Escherichia coli, Salmonella typhi) as well as fungi (Candida albicans). The compound (3a) has shown excellent anti-tubercular activity with MIC of 0.12 μg/mL. Electron donating compounds (3a, 3f) have displayed significant anti-microbial activity. The compounds have also been precisely elucidated using single crystal X-ray diffraction techniques. Molecular docking study has been performed against 4DQU enzyme of Mycobacterium tuberculosis showed good binding interactions and is in agreement with the in vitro results. Copyright © 2018. Published by Elsevier Masson SAS.

  7. Use of non-hyperaccumulator plant species for the phytoextraction of heavy metals using chelating agents

    Directory of Open Access Journals (Sweden)

    Lucas Anjos Souza

    2013-08-01

    Full Text Available Soil contamination by heavy metals is a challenge faced by many countries, and engineering technologies to solve this problem are expensive and can cause negative impacts on the environment. One way to minimise the levels of heavy metals in the soil is to use plants that can absorb and accumulate heavy metals into harvestable parts, a process called phytoextraction. Typical plant species used in research involving phytoextraction are heavy metal hyperaccumulators, but plants from this group are not good biomass producers and grow more slowly than most species; thus, they have an important role in helping scientists understand the mechanisms involved in accumulating high amounts of heavy metals without developing symptoms or dying. However, because of their slow growth, it is not practical to use these species for phytoextraction. An alternative approach is to use non-hyperaccumulator plants assisted by chelating agents, which may improve the ability of plants to accumulate more heavy metals than they would naturally. Chelating agents can be synthetic or organic acids, and the advantages and disadvantages of their use in improving the phytoextraction potential of non-hyperaccumulator plants are discussed in this article. We hope to draw attention to ways to improve the phytoextraction potential of non-hyperaccumulator plants that produce a large amount of biomass and to stimulate more research on phytoextraction-inducing substances.

  8. In vitro susceptibility of contagious ovine digital dermatitis associated Treponema spp. isolates to antimicrobial agents in the UK

    OpenAIRE

    Angell, Joseph W.; Clegg, Simon R.; Sullivan, Leigh E.; Duncan, Jennifer S.; Grove?White, Dai H.; Carter, Stuart D.; Evans, Nicholas J.

    2015-01-01

    Background: Contagious ovine digital dermatitis (CODD) is an important cause of infectious lameness in sheep in the UK and Ireland and has a severe impact on the welfare of affected individuals. The three treponemal phylogroups Treponema medium/Treponema vincentii-like, Treponema phagedenis-like and Treponema pedis spirochaetes have been associated with clinical CODD lesions and are considered to be a necessary cause of disease. There are scant data on the antimicrobial susceptibility of the ...

  9. The SOS Chromotest applied for screening plant antigenotoxic agents against ultraviolet radiation.

    Science.gov (United States)

    Fuentes, J L; García Forero, A; Quintero Ruiz, N; Prada Medina, C A; Rey Castellanos, N; Franco Niño, D A; Contreras García, D A; Córdoba Campo, Y; Stashenko, E E

    2017-09-13

    In this work, we investigated the usefulness of the SOS Chromotest for screening plant antigenotoxic agents against ultraviolet radiation (UV). Fifty Colombian plant extracts obtained by supercritical fluid (CO 2 ) extraction, twelve plant extract constituents (apigenin, carvacrol, β-caryophyllene, 1,8-cineole, citral, p-cymene, geraniol, naringenin, pinocembrin, quercetin, squalene, and thymol) and five standard antioxidant and/or photoprotective agents (curcumin, epigallocatechin gallate, resveratrol, α-tocopherol, and Trolox®) were evaluated for their genotoxicity and antigenotoxicity against UV using the SOS Chromotest. None of the plant extracts, constituents or agents were genotoxic in the SOS Chromotest at tested concentrations. Based on the minimal extract concentration that significantly inhibited UV-genotoxicity (CIG), five plant extracts were antigenotoxic against UV as follows: Baccharis nítida (16 μg mL -1 ) = Solanum crotonifolium (16 μg mL -1 ) > Hyptis suaveolens (31 μg mL -1 ) = Persea caerulea (31 μg mL -1 ) > Lippia origanoides (62 μg mL -1 ). Based on CIG values, the flavonoid compounds showed the highest antigenotoxic potential as follows: apigenin (7 μM) > pinocembrin (15 μM) > quercetin (26 μM) > naringenin (38 μM) > epigallocatechin gallate (108 μM) > resveratrol (642 μM). UV-genotoxicity inhibition with epigallocatechin gallate, naringenin and resveratrol was related to its capability for inhibiting protein synthesis. A correlation analysis between compound antigenotoxicity estimates and antioxidant activity evaluated by the oxygen radical absorbance capacity (ORAC) assay showed that these activities were not related. The usefulness of the SOS Chromotest for bioprospecting of plant antigenotoxic agents against UV was discussed.

  10. Bio-synthesis of silver nanoparticles using Potentilla fulgens Wall. ex Hook. and its therapeutic evaluation as anticancer and antimicrobial agent

    International Nuclear Information System (INIS)

    Mittal, Amit Kumar; Tripathy, Debabrata; Choudhary, Alka; Aili, Pavan Kumar; Chatterjee, Anupam; Singh, Inder Pal; Banerjee, Uttam Chand

    2015-01-01

    The present study aims to develop an easy and eco-friendly method for the synthesis of silver nanoparticles using extracts from the medicinal plant, Potentilla fulgens and evaluation of its anticancer and antimicrobial properties. The various parts of P. fulgens were screened and the root extract was found to have the highest potential for the synthesis of nanoparticles. The root extracts were able to quickly reduce Ag + to Ag 0 and stabilized the nanoparticles. The synthesis of nanoparticles was confirmed by UV–Visible spectrophotometry and further characterized using Zeta sizer, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Electron microscopic study showed that the size of the nanoparticle was in the range of 10 to 15 nm and spherical in shape. The studies of phytochemical analysis of nanoparticles indicated that the adsorbed components on the surface of nanoparticles were mainly flavonoid in nature. Furthermore, nanoparticles were evaluated as cytotoxic against various cancer cell lines and 0.2 to 12 μg/mL nanoparticles showed good toxicity. The IC 50 value of nanoparticles was found to be 4.91 and 8.23 μg/mL against MCF-7 and U-87 cell lines, respectively. Additionally, the apoptotic effect of synthesized nanoparticles on normal and cancer cells was studied using trypan blue assay and flow-cytometric analysis. The results indicate the synthesized nanoparticle ability to kill cancer cells compared to normal cells. The nanoparticles also exhibited comparable antimicrobial activity against both Gram-positive and Gram-negative bacteria. - Highlights: • Bio-synthesis of AgNPs using a medicinal plant Potentilla fulgens Wall. ex Hook. • Optimization of NP synthesis and its characterization using various techniques • Determination of therapeutic potential in terms of anticancer and antimicrobial properties • To know the mechanistic apoptosis effect of

  11. Bio-synthesis of silver nanoparticles using Potentilla fulgens Wall. ex Hook. and its therapeutic evaluation as anticancer and antimicrobial agent

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Amit Kumar [Department of Pharmaceutical Technology Biotechnology, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, 160062 Punjab (India); Tripathy, Debabrata [Department of Biotechnology and Bioinformatics, North Eastern Hill University, Shillong, 793002 Meghalaya (India); Choudhary, Alka [Department of Natural Products, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, 160062 Punjab (India); Aili, Pavan Kumar [Department of Pharmaceutical Technology Biotechnology, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, 160062 Punjab (India); Chatterjee, Anupam [Department of Biotechnology and Bioinformatics, North Eastern Hill University, Shillong, 793002 Meghalaya (India); Singh, Inder Pal [Department of Natural Products, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, 160062 Punjab (India); Banerjee, Uttam Chand, E-mail: ucbanerjee@niper.ac.in [Department of Pharmaceutical Technology Biotechnology, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, 160062 Punjab (India)

    2015-08-01

    The present study aims to develop an easy and eco-friendly method for the synthesis of silver nanoparticles using extracts from the medicinal plant, Potentilla fulgens and evaluation of its anticancer and antimicrobial properties. The various parts of P. fulgens were screened and the root extract was found to have the highest potential for the synthesis of nanoparticles. The root extracts were able to quickly reduce Ag{sup +} to Ag{sup 0} and stabilized the nanoparticles. The synthesis of nanoparticles was confirmed by UV–Visible spectrophotometry and further characterized using Zeta sizer, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Electron microscopic study showed that the size of the nanoparticle was in the range of 10 to 15 nm and spherical in shape. The studies of phytochemical analysis of nanoparticles indicated that the adsorbed components on the surface of nanoparticles were mainly flavonoid in nature. Furthermore, nanoparticles were evaluated as cytotoxic against various cancer cell lines and 0.2 to 12 μg/mL nanoparticles showed good toxicity. The IC{sub 50} value of nanoparticles was found to be 4.91 and 8.23 μg/mL against MCF-7 and U-87 cell lines, respectively. Additionally, the apoptotic effect of synthesized nanoparticles on normal and cancer cells was studied using trypan blue assay and flow-cytometric analysis. The results indicate the synthesized nanoparticle ability to kill cancer cells compared to normal cells. The nanoparticles also exhibited comparable antimicrobial activity against both Gram-positive and Gram-negative bacteria. - Highlights: • Bio-synthesis of AgNPs using a medicinal plant Potentilla fulgens Wall. ex Hook. • Optimization of NP synthesis and its characterization using various techniques • Determination of therapeutic potential in terms of anticancer and antimicrobial properties • To know the mechanistic

  12. Antimicrobial efficacy of Syzygium antisepticum plant extract against Staphylococcus aureus and methicillin-resistant S. aureus and its application potential with cooked chicken.

    Science.gov (United States)

    Yuan, Wenqian; Yuk, Hyun-Gyun

    2018-06-01

    For the past decades, there has been a growing demand for natural antimicrobials in the food industry. Plant extracts have attracted strong research interests due to their wide-spectrum antimicrobial activities, but only a limited number have been investigated thoroughly. The present study aimed at identifying a novel anti-staphylococcal plant extract, to validate its activity in a food model, and to investigate on its composition and antimicrobial mechanism. Four plant extracts were evaluated against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in vitro, with Syzygium antisepticum leaf extract showing the strongest antimicrobial activity (MIC = 0.125 mg/mL). Relatively high total phenolic content (276.3 mg GAE/g extract) and antioxidant activities (90.2-138.0 mg TE/g extract) were measured in S. antisepticum extract. Food validation study revealed that higher extract concentration (32 mg/mL) was able to inhibit or reduce staphylococcal growth in cooked chicken, but caused color change on meat surface. By GC-MS, β-caryophyllene (12.76 area%) was identified as the dominant volatile compound in extract. Both crude extract and pure β-caryophyllene induced membrane damages in S. aureus. These results suggested good anti-staphylococcal properties of S. antisepticum plant extract, identified its major volatile composition and its membrane-damaging antimicrobial mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Synthesis and antimicrobial evaluation of two peptide LyeTx I derivatives modified with the chelating agent HYNIC for radiolabeling with technetium-99m.

    Science.gov (United States)

    Fuscaldi, Leonardo Lima; Dos Santos, Daniel Moreira; Pinheiro, Natália Gabriela Silva; Araújo, Raquel Silva; de Barros, André Luís Branco; Resende, Jarbas Magalhães; Fernandes, Simone Odília Antunes; de Lima, Maria Elena; Cardoso, Valbert Nascimento

    2016-01-01

    Current diagnostic methods and imaging techniques are not able to differentiate septic and aseptic inflammation. Thus, reliable methods are sought to provide this distinction and scintigraphic imaging is an interesting option, since it is based on physiological changes. In this context, radiolabeled antimicrobial peptides have been investigated as they accumulate in infectious sites instead of aseptic inflammation. The peptide LyeTx I, from the venom of Lycosa erythrognatha, has potent antimicrobial activity. Therefore, this study aimed to synthesize LyeTx I derivatives with the chelating compound HYNIC, to evaluate their antimicrobial activity and to radiolabel them with (99m)Tc. Two LyeTx I derivatives, HYNIC-LyeTx I (N-terminal modification) and LyeTx I-K-HYNIC (C-terminal modification), were synthesized by Fmoc strategy and purified by RP-HPLC. The purified products were assessed by RP-HPLC and MALDI-ToF-MS analysis. Microbiological assays were performed against S. aureus (ATCC® 6538) and E. coli (ATCC® 10536) in liquid medium to calculate the MIC. The radiolabeling procedure of LyeTx I-K-HYNIC with (99m)Tc was performed in the presence of co-ligands (tricine and EDDA) and reducing agent (SnCl2 (.) 2H2O), and standardized taking into account the amount of peptide, reducing agent, pH and heating. Radiochemical purity analysis was performed by thin-layer chromatography on silica gel strips and the radiolabeled compound was assessed by RP-HPLC and radioactivity measurement of the collected fractions. Data were analyzed by ANOVA, followed by Tukey test (p-values EDDA). The binding of HYNIC to the N-terminal portion of LyeTx I seems to affect its activity against bacteria. Nevertheless, the radiolabeling of the C-terminal derivative, LyeTx I-K-HYNIC, must be better investigated to optimize the radiolabeled compound, in order to use it as a specific imaging agent to distinguish septic and aseptic inflammation.

  14. Antimicrobial Activity of Aerial Part Crude Extracts from the Saharan plant Anabasis aretioides

    Directory of Open Access Journals (Sweden)

    A. AMARI

    2015-03-01

    Full Text Available The antimicrobial activity of several crude extracts from the aerial parts of Anabasis aretioides was investigated by the disc diffusion method. The S. aureus, C. albicans and S. cereviceae Bacteria showed good efficiency in bacterial activity with most of the tested extract.

  15. Synergism of Plant Compound With Traditional Antimicrobials Against Streptococcus spp. Isolated From Bovine Mastitis

    Directory of Open Access Journals (Sweden)

    Natasha L. Maia

    2018-06-01

    Full Text Available Mastitis is an inflammation of the mammary gland that causes major losses in the dairy industry. Streptococcus spp. are among the main agents of this disease. Increased resistance to antibiotics is one of the causes of therapeutic failure. Plants, due to their broad chemodiversity, are an interesting source of new molecules with antibacterial activity. Using these compounds along with traditional antibiotics is a possible method for reversing resistance. The objective of this work was to determine the interactions between the activities of guttiferone-A and 7-epiclusianone, two active substances isolated from the fruits of Garcinia brasiliensis, and traditional antibiotics against Streptococcus spp. isolated from bovine mastitis and known to be resistant to them. First, the MIC for the antibiotics and bioactive compounds was determined, followed by their activities, alone and in combination. Then, their cytotoxicity was measured in bovine mammary epithelial cells. Finally, molecular docking simulations were performed to elucidate molecular details of the interactions between β-lactamase and the compounds binding to it (clavulanic acid, ampicillin, 7-epiclusianone, and guttiferone-A. The bacterial isolates were resistant to ampicillin and gentamicin. Both antibiotics showed predominantly synergistic antibacterial activities in combination with guttiferone-A or 7-epiclusianone. These two active substances were not cytotoxic at synergistic concentrations and both showed strong binding to β-lactamase, which may explain the reversal of ampicillin resistance. These substances are promising for the treatment of bovine mastitis.

  16. An Approach Towards Structure Based Antimicrobial Peptide Design for Use in Development of Transgenic Plants: A Strategy for Plant Disease Management.

    Science.gov (United States)

    Ilyas, Humaira; Datta, Aritreyee; Bhunia, Anirban

    2017-01-01

    Antimicrobial peptides (AMPs), also known as host defense peptides (HDPs), are ubiquitous and vital components of innate defense response that present themselves as potential candidates for drug design, and aim to control plant and animal diseases. Though their application for plant disease management has long been studied with natural AMPs, cytotoxicity and stability related shortcomings for the development of transgenic plants limit their usage. Newer technologies like molecular modelling, NMR spectroscopy and combinatorial chemistry allow screening for potent candidates and provide new avenues for the generation of rationally designed synthetic AMPs with multiple biological functions. Such AMPs can be used for the control of plant diseases that lead to huge yield losses of agriculturally important crop plants, via generation of transgenic plants. Such approaches have gained significant attention in the past decade as a consequence of increasing antibiotic resistance amongst plant pathogens, and the shortcomings of existing strategies that include environmental contamination and human/animal health hazards amongst others. This review summarizes the recent trends and approaches used for employing AMPs, emphasizing on designed/modified ones, and their applications toward agriculture and food technology. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Antimicrobial Properties of Plant Essential Oils against Human Pathogens and Their Mode of Action: An Updated Review

    Directory of Open Access Journals (Sweden)

    Mallappa Kumara Swamy

    2016-01-01

    Full Text Available A wide range of medicinal and aromatic plants (MAPs have been explored for their essential oils in the past few decades. Essential oils are complex volatile compounds, synthesized naturally in different plant parts during the process of secondary metabolism. Essential oils have great potential in the field of biomedicine as they effectively destroy several bacterial, fungal, and viral pathogens. The presence of different types of aldehydes, phenolics, terpenes, and other antimicrobial compounds means that the essential oils are effective against a diverse range of pathogens. The reactivity of essential oil depends upon the nature, composition, and orientation of its functional groups. The aim of this article is to review the antimicrobial potential of essential oils secreted from MAPs and their possible mechanisms of action against human pathogens. This comprehensive review will benefit researchers who wish to explore the potential of essential oils in the development of novel broad-spectrum key molecules against a broad range of drug-resistant pathogenic microbes.

  18. Antimicrobial Properties of Plant Essential Oils against Human Pathogens and Their Mode of Action: An Updated Review

    Science.gov (United States)

    2016-01-01

    A wide range of medicinal and aromatic plants (MAPs) have been explored for their essential oils in the past few decades. Essential oils are complex volatile compounds, synthesized naturally in different plant parts during the process of secondary metabolism. Essential oils have great potential in the field of biomedicine as they effectively destroy several bacterial, fungal, and viral pathogens. The presence of different types of aldehydes, phenolics, terpenes, and other antimicrobial compounds means that the essential oils are effective against a diverse range of pathogens. The reactivity of essential oil depends upon the nature, composition, and orientation of its functional groups. The aim of this article is to review the antimicrobial potential of essential oils secreted from MAPs and their possible mechanisms of action against human pathogens. This comprehensive review will benefit researchers who wish to explore the potential of essential oils in the development of novel broad-spectrum key molecules against a broad range of drug-resistant pathogenic microbes. PMID:28090211

  19. Studies of the in vitro anticancer, antimicrobial and antioxidant potentials of selected Yemeni medicinal plants from the island Soqotra

    Directory of Open Access Journals (Sweden)

    Bednarski Patrick J

    2009-03-01

    Full Text Available Abstract Background Recent years have witnessed that there is a revival of interest in drug discovery from medicinal plants for the maintenance of health in all parts of the world. The aim of this work was to investigate 26 plants belonging to 17 families collected from a unique place in Yemen (Soqotra Island for their in vitro anticancer, antimicrobial and antioxidant activities. Methods The 26 plants were extracted with methanol and hot water to yield 52 extracts. Evaluation for in vitro anticancer activity was done against three human cancer cell lines (A-427, 5637 and MCF-7 by using an established microtiter plate assay based on cellular staining with crystal violet. Antimicrobial activity was tested against three Gram-positive bacteria, two Gram-negative bacteria, one yeast species and three multiresistant Staphylococcus strains by using an agar diffusion method and the determination of MIC against three Gram-positive bacteria with the broth micro-dilution assay. Antioxidant activity was investigated by measuring the scavenging activity of the DPPH radical. Moreover, a phytochemical screening of the methanolic extracts was done. Results Notable cancer cell growth inhibition was observed for extracts from Ballochia atro-virgata, Eureiandra balfourii and Hypoestes pubescens, with IC50 values ranging between 0.8 and 8.2 μg/ml. The methanol extracts of Acanthospermum hispidum, Boswellia dioscorides, Boswellia socotrana, Commiphora ornifolia and Euphorbia socotrana also showed noticeable antiproliferative potency with IC50 values Acacia pennivenia, Boswellia dioscorides, Boswellia socotrana, Commiphora ornifolia, Euclea divinorum, Euphorbia socotrana, Leucas samhaensis, Leucas virgata, Rhus thyrsiflora, and Teucrium sokotranum with inhibition zones > 15 mm and MIC values ≤ 250 μg/ml. In addition, the methanolic extracts of Acacia pennivenia, Boswellia dioscorides, Boswellia socotrana and Commiphora ornifolia showed good antioxidant potential

  20. Plant growth-promoting rhizobacteria (PGPR: their potential as antagonists and biocontrol agents

    Directory of Open Access Journals (Sweden)

    Anelise Beneduzi

    2012-01-01

    Full Text Available Bacteria that colonize plant roots and promote plant growth are referred to as plant growth-promoting rhizobacteria (PGPR. PGPR are highly diverse and in this review we focus on rhizobacteria as biocontrol agents. Their effects can occur via local antagonism to soil-borne pathogens or by induction of systemic resistance against pathogens throughout the entire plant. Several substances produced by antagonistic rhizobacteria have been related to pathogen control and indirect promotion of growth in many plants, such as siderophores and antibiotics. Induced systemic resistance (ISR in plants resembles pathogen-induced systemic acquired resistance (SAR under conditions where the inducing bacteria and the challenging pathogen remain spatially separated. Both types of induced resistance render uninfected plant parts more resistant to pathogens in several plant species. Rhizobacteria induce resistance through the salicylic acid-dependent SAR pathway, or require jasmonic acid and ethylene perception from the plant for ISR. Rhizobacteria belonging to the genera Pseudomonas and Bacillus are well known for their antagonistic effects and their ability to trigger ISR. Resistance-inducing and antagonistic rhizobacteria might be useful in formulating new inoculants with combinations of different mechanisms of action, leading to a more efficient use for biocontrol strategies to improve cropping systems.

  1. Phytochemical And In Vitro Antimicrobial Assay Of The Leaf Extract ...

    African Journals Online (AJOL)

    This study has justified the traditional use of this plant for the treatment of stomach discomfort, diarrhea, dysentery and as a remedy for wound healing whose causative agents are some of the organisms used in this study. Keywords: Antimicrobial, Leaf Extracts,In Vitro, Phytochemical, Newbouldia laevis. African Journal of ...

  2. In vitro activity of 24 antimicrobial agents against Staphylococcus and Streptococcus isolated from diseased animals in Japan.

    Science.gov (United States)

    Morioka, Ayako; Asai, Tetsuo; Ishihara, Kanako; Kojima, Akemi; Tamura, Yutaka; Takahashi, Toshio

    2005-02-01

    A total of 88 Staphylococcus and 61 Streptococcus isolates from diseased animals throughout Japan were examined in 2000 for the minimum inhibitory concentrations of 24 different antimicrobials by the agar dilution method standardized by the Japanese Society of Chemotherapy. The resistance rates to aminobenzylpenicillin (36.4%) and benzylpenicillin (35.2%) were high in Staphylococcus isolates, and those to oxytetracycline (45.9%) and kanamycin (21.3%) were high in Streptococcus isolates. Two isolates resistant to oxacillin harbored the mecA gene. One was Staphylococcus epidermidis derived from a pig with arthritis, and the other Staphylococcus cohnii from a head of cattle with mastitis.

  3. Novel derivatives of 5,6-dimethoxy-1-indanone coupled with substituted pyridine as potential antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Vimal M. Patel

    2018-01-01

    Full Text Available Synthesis of novel derivatives of 5,6-dimethoxy-1-indanone was carried out via its Schiff’s base using 2-cyanoacetohydrazide followed by cyclization with 2-arylidenemalononitrile in the presence of a catalytical amount of piperidine to get 6-amino-1-(5,6-dimethoxy-2,3-dihydro-1H-inden-1-ylideneamino-2-oxo-4-aryl-1,2-dihydropyridine-3,5-dicarbonitrile derivatives. The structures of the synthesized compounds were confirmed on the basis of their spectral and elemental analysis. The synthesized compounds were also screened for antimicrobial activity and found to have promising antibacterial activity.

  4. Antimicrobial activity of southern African medicinal plants with dermatological relevance: From an ethnopharmacological screening approach, to combination studies and the isolation of a bioactive compound.

    Science.gov (United States)

    Mabona, Unathi; Viljoen, Alvaro; Shikanga, Emmanual; Marston, Andrew; Van Vuuren, Sandy

    2013-06-21

    Ethnobotanical reports on more than 100 southern African medicinal plants with dermatological relevance have been highlighted, yet there is still limited scientific data to support claims for their antimicrobial effectiveness against skin pathogens. Guided by ethnobotanical data, this paper explores the antimicrobial efficacies of southern African medicinal plants used to treat skin ailments. To investigate the antimicrobial properties of southern African medicinal plants against dermatologically relevant pathogens. The study also aimed at providing a scientific rationale for the traditional use of plant combinations to treat skin diseases and the isolation of the bio-active compound from the most active species, Aristea ecklonii (Iridaceae). Organic and aqueous extracts (132) were prepared from 47 plant species and screened for antimicrobial properties against dermatologically relevant pathogens using the micro-titre plate dilution method. Four different plant combinations were investigated for interactive properties and the sum of the fractional inhibitory concentration (ƩFIC) calculated. Isobolograms were used to further investigate the antimicrobial interactive properties of Pentanisia prunelloides combined with Elephantorrhiza elephantina at varied ratios. A bioactivity-guided fractionation process was adopted to fractionate the organic leaf extract of Aristea ecklonii. Plants demonstrating notable broad-spectrum activities (MIC values ≤1.00mg/ml) against the tested pathogens included extracts from Aristea ecklonii, Chenopodium ambrosioides, Diospyros mespiliformis, Elephantorrhiza elephantina, Eucalyptus camaldulensis, Gunnera perpensa, Harpephyllum caffrum, Hypericum perforatum, Melianthus comosus, Terminalia sericea and Warburgia salutaris. The organic extract of Elephantorrhiza elephantina, a plant reportedly used to treat acne vulgaris, demonstrated noteworthy antimicrobial activity (MIC value of 0.05mg/ml) against Propionibacterium acnes. Similarly

  5. THE EFFECT OF DIFFERENT TB DRUGS AND ANTIMICROBIAL AGENTS ON THE EFFICIENCY OF TREATMENT OF TUBERCULOSIS PATIENTS WITH MULTIPLE DRUG RESISTANCE

    Directory of Open Access Journals (Sweden)

    I. A. Vasilyeva

    2017-01-01

    Full Text Available Objective of the study: to study the effect of specific TB drugs and antimicrobial agents constituting chemotherapy regimens on the efficiency of treatment of tuberculosis patients with various patterns of multiple drug resistance.Subjects and Methods. 412 pulmonary tuberculosis patients with bacillary excretion and various patterns of multiple drug resistance were enrolled into the study (117 patients with MDR TB (non pre-XDR and non-XDR; 120 patients with pre-XDR TB and 175 with XDR TB. Patients in the subgroups were compatible regarding sex and age. The patients were prescribed regimens including 5-6 drugs in accordance with their drug resistance pattern. The time of sputum conversion (by culture versus the year of treatment was selected as a surrogate endpoint. The effect of specific TB drugs and antimicrobial agents on treatment efficiency was assessed through calculation of odds ratio (OR of achieving a surrogate endpoint in the patients receiving and not receiving a certain drug.Results. In the subgroup of pre-XDR TB, the following drugs demonstrated the valid increase of odds of sputum conversion: ethambutol (OR 11.8, pyrazinamide (OR 10.2, moxifloxacin (OR 7.8, capreomicin (OR 4.41. Sputum conversion was achieved in all 11 patients treated with bedaquiline.In the subgroup of XDR TB, the following drugs provided a positive effect on the achievement of sputum conversion: bedaquiline (OR 9.62, linezolid (OR 8.15, cycloserine (OR 7.88, pyrazinamide (OR 7.29, moxifloxacin (OR 7.08, and ethambutol (OR 6.69. Ofloxacin demonstrated a confident negative effect on achieving sputum conversion (95% CI 0.06-0.32. 

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

    Science.gov (United States)

    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.

  7. Trichoderma spp.: a biocontrol agent for sustainable management of plant diseases

    International Nuclear Information System (INIS)

    Naher, L.; Ismail, A.

    2014-01-01

    Trichoderma spp. are mainly asexual fungi that are present in all types of agricultural soils and also in decaying wood. The antagonistic activity of Trichoderma species showed that it is parasitic on many soil-borne and foliage pathogens. The fungus is also a decomposer of cellulosic waste materials. Recent discoveries show that the fungi not only act as biocontrol agents, but also stimulate plant resistance, and plant growth and development resulting in an increase in crop production. The biocontrol activity involving mycoparasitism, antibiotics and competition for nutrients, also induces defence responses or systemic resistance responses in plants. These responses are an important part of Trichoderma in biocontrol program. Currently, Trichoderma spp., is being used to control plant diseases in sustainable diseases management systems. This paper reviews the published information on Trichoderma spp., and its biocontrol activity in sustainable disease management programs. (author)

  8. Preventative and Curative Effects of Several Plant Derived Agents Against Powdery Mildew Disease of Okra

    Directory of Open Access Journals (Sweden)

    Moustafa Hemdan Ahmed MOHARAM

    2012-08-01

    Full Text Available The preventative and curative effects of some plant derived agents based on plant extracts or essential oils were studied at different concentrations against Erysiphe cichoracearum DC. ex Merat, the causal pathogen of okra powdery mildew by the detached leaf-disk and potted plants bioassays. Through detached leaf-disk assay, the highest mean preventative effect (97.74% was recorded by neem seed oil followed by jojoba oil (89.82% and extract of Rynoutria sachalinensis (82.77%. Neem seed oil at 1% was the most effective agent followed by jojoba oil and extract of R. sachalinensis at 1.5% and 2%, respectively, where they suppressed E. cichoracearum completely. Potted plants assay revealed that neem seed oil, jojoba oil and extract of R. sachalinensis as well as the fungicide (active ingredient dinocap showed higher preventative efficacy at all leaf olds treated after 7 and 14 days of inoculation as compared with extracts of henna and garlic. Moreover, the preventative efficacy partly remained apparent after 14 days of inoculation at all leaf olds tested. In field trials through 2010 and 2011 growing seasons, when the first symptoms of powdery mildew appeared naturally, 1.5% jojoba oil, 2% extract of R. sachalinensis and 1% neem seed oil were sprayed individually twice on grown plants to evaluate their efficacy on controlling powdery mildew, growth and yield of okra. Resulted showed that neem seed oil was the most effective agent and highly decreased the disease severity to 29.92%, recorded the highly curative effect (68.15% and also improved plant growth and pods yield.

  9. Antibiotic Conjugated Fluorescent Carbon Dots as a Theranostic Agent for Controlled Drug Release, Bioimaging, and Enhanced Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Mukeshchand Thakur

    2014-01-01

    Full Text Available A novel report on microwave assisted synthesis of bright carbon dots (C-dots using gum arabic (GA and its use as molecular vehicle to ferry ciprofloxacin hydrochloride, a broad spectrum antibiotic, is reported in the present work. Density gradient centrifugation (DGC was used to separate different types of C-dots. After careful analysis of the fractions obtained after centrifugation, ciprofloxacin was attached to synthesize ciprofloxacin conjugated with C-dots (Cipro@C-dots conjugate. Release of ciprofloxacin was found to be extremely regulated under physiological conditions. Cipro@C-dots were found to be biocompatible on Vero cells as compared to free ciprofloxacin (1.2 mM even at very high concentrations. Bare C-dots (∼13 mg mL−1 were used for microbial imaging of the simplest eukaryotic model—Saccharomyces cerevisiae (yeast. Bright green fluorescent was obtained when live imaging was performed to view yeast cells under fluorescent microscope suggesting C-dots incorporation inside the cells. Cipro@C-dots conjugate also showed enhanced antimicrobial activity against both model gram positive and gram negative microorganisms. Thus, the Cipro@C-dots conjugate paves not only a way for bioimaging but also an efficient new nanocarrier for controlled drug release with high antimicrobial activity, thereby serving potential tool for theranostics.

  10. In vitro antibacterial effect of exotic plants essential oils on the honeybee pathogen Paenibacillus larvae, causal agent of American foul brood

    Energy Technology Data Exchange (ETDEWEB)

    Fuselli, S. R.; Garcia de la Rosa, S. B.; Eguaras, M. J.; Fritz, R.

    2010-07-01

    Chemical composition and antimicrobial activity of exotic plants essential oils to potentially control Paenibacillus larvae, the causal agent of American foul brood disease (AFB) were determined. AFB represents one of the main plagues that affect the colonies of honeybees Apis mellifera L. with high negative impact on beekeepers worldwide. Essential oils tested were niaouli (Melaleuca viridiflora) and tea tree (Melaleuca alternifolia) from Myrtaceae, and citronella grass (Cymbopogon nardus) and palmarosa (Cymbopogon martinii) from Gramineae. The components of the essential oils were identified by SPME-GC/MS analysis. The antimicrobial activity of the oils against P. larvae was determined by the broth micro dilution method. In vitro assays of M. viridiflora and C. nardus oils showed the inhibition of the bacterial strains at the lowest concentrations tested, with minimal inhibitory concentration (MIC) mean value about 320 mg L{sup -}1 for both oils, respectively. This property could be attributed to the kind and percentage of the components of the oils. Terpinen-4-ol (29.09%), {alpha}-pinene (21.63%) and limonene (17.4%) were predominant in M. viridiflora, while limonene (24.74%), citronelal (24.61%) and geraniol (15.79%) were the bulk of C. nardus. The use of these essential oils contributes to the screening of alternative natural compounds to control AFB in the apiaries; toxicological risks and other undesirable effects would be avoided as resistance factors, developed by the indiscriminate use of antibiotics. (Author) 40 refs.

  11. Frequency of resistance to methicillin and other antimicrobial agents among Staphylococcus aureus strains isolated from pigs and their human handlers in Trinidad

    Directory of Open Access Journals (Sweden)

    Annika Gordon

    2014-04-01

    Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA has emerged recently worldwide in production animals, particularly pigs and veal calves, which act as reservoirs for MRSA strains for human infection. The study determined the prevalence of MRSA and other resistant strains of S. aureus isolated from the anterior nares of pigs and human handlers on pig farms in Trinidad. Methods: Isolation of S. aureus was done by concurrently inoculating Baird-Parker agar (BPA and Chromagar MRSA (CHROM with swab samples and isolates were identified using standard methods. Suspect MRSA isolates from Chromagar and BPA were subjected to confirmatory test using Oxoid PBP2 latex agglutination test. The disc diffusion method was used to determine resistance to antimicrobial agents. Results: The frequency of isolation of MRSA was 2.1% (15 of 723 for pigs but 0.0% (0 of 72 for humans. Generally, for isolates of S. aureus from humans there was a high frequency of resistance compared with those from pigs, which had moderate resistance to the following antimicrobials: penicillin G (54.5%, 51.5%, ampicillin (59.1%, 49.5%, and streptomycin (59.1%, 37.1%, respectively. There was moderate resistance to tetracycline (36.4%, 41.2% and gentamycin (27.2%, 23.7% for human and pig S. aureus isolates, respectively, and low resistance to sulfamethoxazole-trimethoprim (4.5%, 6.2% and norfloxacin (9.1%, 12.4%, respectively. The frequency of resistance to oxacillin by the disc method was 36.4 and 34.0% from S. aureus isolates from humans and pigs, respectively. Out of a total of 78 isolates of S. aureus from both human and pig sources that were resistant to oxacillin by the disc diffusion method, only 15 (19.2% were confirmed as MRSA by the PBP'2 latex test kit. Conclusions: The detection of MRSA strains in pigs, albeit at a low frequency, coupled with a high frequency of resistance to commonly used antimicrobial agents in pig and humans could have zoonotic and therapeutic

  12. Antimicrobial potential of actinobacteria isolated from the rhizosphere of the Caatinga biome plant Caesalpinia pyramidalis Tul.

    Science.gov (United States)

    Silva-Lacerda, G R; Santana, R C F; Vicalvi-Costa, M C V; Solidônio, E G; Sena, K X F R; Lima, G M S; Araújo, J M

    2016-03-04

    Actinobacteria are known to produce various secondary metabolites having antibiotic effects. This study assessed the antimicrobial potential of actinobacteria isolated from the rhizosphere of Caesalpinia pyramidalis Tul. from the Caatinga biome. Sixty-eight actinobacteria isolates were evaluated for antimicrobial activity against different microorganisms by disk diffusion and submerged fermentation, using different culture media, followed by determination of minimum inhibitory concentration (MIC) and chemical prospecting of the crude extract. Of the isolates studied, 52.9% of those isolated at 37°C and 47.05% of those isolated at 45°C had activity against Bacillus subtilis, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Fusarium moniliforme, and Candida albicans. When compared with others actinobacteria, the isolate C1.129 stood out with better activity and was identified by 16S rDNA gene analysis as Streptomyces parvulus. The crude ethanol extract showed an MIC of 0.97 μg/mL for MRSA and B. subtilis, while the ethyl acetate extract showed MIC of 3.9 μg/mL for S. aureus and MRSA, showing the greatest potential among the metabolites produced. Chemical prospecting revealed the presence of mono/sesquiterpenes, proanthocyanidin, triterpenes, and steroids in both crude extracts. This study evaluates S. parvulus activity against multi-resistant microorganisms such as MRSA. Thus, it proves that low-fertility soil, as is found in the Caatinga, may contain important microorganisms for the development of new antimicrobial drugs.

  13. [Antimicrobial susceptibility testing in clinically relevant non-fermenting gram-negative bacilli: recommendations from the Antimicrobial Agents Subcommittee of the Sociedad Argentina de Bacteriología, Micología y Parasitología Clínicas, Asociación Argentina de Microbiología].

    Science.gov (United States)

    Radice, Marcela; Marín, Marcelo; Giovanakis, Marta; Vay, Carlos; Almuzara, Marisa; Limansky, Adriana; Casellas, José M; Famiglietti, Angela; Quinteros, Mirta; Bantar, Carlos; Galas, Marcelo; Kovensky Pupko, Jaime; Nicola, Federico; Pasterán, Fernando; Soloaga, Rolando; Gutkind, Gabriel

    2011-01-01

    This document contains the recommendations for antimicrobial susceptibility testing of the clinically relevant non-fermenting gram-negative bacilli (NFGNB), adopted after conforming those from international committees to the experience of the Antimicrobial Agents Subcommittee members and invited experts. This document includes an update on NFGNB classification and description, as well as some specific descriptions regarding natural or frequent antimicrobial resistance and a brief account of associated resistance mechanisms. These recommendations not only suggest the antimicrobial drugs to be evaluated in each case, but also provide an optimization of the disk diffusion layout and a selection of results to be reported. Finally, this document also includes a summary of the different methodological approaches that may be used for detection and confirmation of emerging b-lactamases, such as class A and B carbapenemases.

  14. Antimicrobial activity of Diospyros melanoxylon bark from Similipal ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-04

    May 4, 2009 ... However, very limited studies on medicinal plants in general and antimicrobial ..... Recio MC (1989). A review of some antimicrobial compounds isolated ... Rwandese medicinal plants for antimicrobial and antiviral properties.

  15. Antimicrobial Agent of Susceptibilities and Antiseptic Resistance Gene Distribution among Methicillin-Resistant Staphylococcus aureus Isolates from Patients with Impetigo and Staphylococcal Scalded Skin Syndrome

    Science.gov (United States)

    Noguchi, Norihisa; Nakaminami, Hidemasa; Nishijima, Setsuko; Kurokawa, Ichiro; So, Hiromu; Sasatsu, Masanori

    2006-01-01

    The susceptibilities to antimicrobial agents of and distributions of antiseptic resistance genes in methicillin-resistant Staphylococcus aureus (MRSA) strains isolated between 1999 and 2004 in Japan were examined. The data of MRSA strains that are causative agents of impetigo and staphylococcal scalded skin syndrome (SSSS) were compared with those of MRSA strains isolated from patients with other diseases. The susceptibilities to antiseptic agents in MRSA isolates from patients with impetigo and SSSS were higher than those in MRSA isolates from patients with other diseases. The distribution of the qacA/B genes in MRSA strains isolated from patients with impetigo and SSSS (1.3%, 1/76) was remarkably lower than that in MRSA strains isolated from patients with other diseases (45.9%, 95/207). Epidemiologic typings of staphylococcal cassette chromosome mec (SCCmec) and pulsed-field gel electrophoresis (PFGE) showed that MRSA strains isolated from patients with impetigo and SSSS had type IV SCCmec (75/76), except for one strain, and 64.5% (49/76) of the strains had different PFGE types. In addition, the patterns of restriction digestion of all tested qacA/B plasmid in MRSA isolates having different PFGE types were identical. The results showed that a specific MRSA clone carrying qacA/B was not prevalent, but qacA/B was spread among health care-associated MRSA strains. Therefore, it was concluded that the lower distribution rate of qacA/B resulted in higher susceptibilities to cationic antiseptic agents in MRSA isolated from patients with impetigo and SSSS. PMID:16757607

  16. Combinations of biocontrol agents for management of plant-parasitic nematodes and soilborne plant-pathogenic fungi.

    Science.gov (United States)

    Meyer, Susan L F; Roberts, Daniel P

    2002-03-01

    Numerous microbes are antagonistic to plant-parasitic nematodes and soilborne plant-pathogenic fungi, but few of these organisms are commercially available for management of these pathogens. Inconsistent performance of applied biocontrol agents has proven to be a primary obstacle to the development of successful commercial products. One of the strategies for overcoming inconsistent performance is to combine the disease-suppressive activity of two (or more) beneficial microbes in a biocontrol preparation. Such combinations have potential for more extensive colonization of the rhizosphere, more consistent expression of beneficial traits under a broad range of soil conditions, and antagonism to a larger number of plant pests or pathogens than strains applied individually. Conversely, microbes applied in combination also may have antagonistic interactions with each other. Increased, decreased, and unaltered suppression of the target pathogen or pest has been observed when biocontrol microbes have been applied in combination. Unfortunately, the ecological basis for increased or decreased suppression has not been determined in many cases and needs further consideration. The complexity of interactions involved in the application of multiple organisms for biological control has slowed progress toward development of successful formulations. However, this approach has potential for overcoming some of the efficacy problems that occur with application of individual biocontrol agents.

  17. Microwave-assisted synthesis of new pyrazole derivatives bearing 1,2,3-triazole scaffold as potential antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Ashok Dongamanti

    2017-01-01

    Full Text Available A new series of (E-3-(3-(4-substituted phenyl-1-phenyl-1H-pyrazol- 4-yl-1-(2-hydroxy-4-((1-aryl-1H-1-2,3-triazol-4-ylmethoxyphenyl- prop-2-en-1-one derivatives was synthesized. The synthesis of the title compounds involved the 1,3-dipolar Cu(I-catalyzed alkyne–azide cycloaddition (CuAAC reaction of (E-3-(3-(4-substituted phenyl-1-phenyl-1H-pyrazol-4- -yl-1-(2-hydroxy-4-(prop-2-yn-1-yloxyphenylprop-2-en-1-ones with aromatic azides. The structures were confirmed by NMR, FT-IR, mass and elemental analysis. All the synthesized compounds (6a–j were evaluated for their antimicrobial activity. Compounds 6a, 6d and 6e demonstrated promising inhibitory effects on both bacterial and fungal strains.

  18. Design and Synthesis of Some New Quinoline Based 1,2,3-Triazoles as Antimicrobial and Antimalarial Agents

    Directory of Open Access Journals (Sweden)

    Parthasaradhi Y.

    2015-09-01

    Full Text Available A series of novel 6-bromo-2-chloro-3-(4-phenyl-[1,2,3]triazol-1-ylmethyl-quinoline and its derivatives (5a-j were synthesized in good yields from the intermediates (6-bromo-2-chloro-quinolin-3-yl-methanol (2, methanesulfonic acid (6-bromo-2-chloroquinolin-3-ylmethyl methanesulfonate (3 and 3-azidomethyl-6-bromo-2-chloro-quinoline (4. The synthetic route leading to the title compounds is commenced from commercially available 6-bromo-2-chloro-quinolin-3-carbaldehyde (1. The chemical structures of the newly synthesized compounds were elucidated by their IR, 1H and 13C NMR, mass spectral data and elemental analysis. Further, all the target compounds were screened for their antimicrobial activity against various microorganisms and antimalarial activity towards P. falciparum. DOI: http://dx.doi.org/10.17807/orbital.v7i3.692 

  19. In vitro and in vivo assessment of newer quinoxaline-oxadiazole hybrids as antimicrobial and antiprotozoal agents.

    Science.gov (United States)

    Patel, Navin B; Patel, Jignesh N; Purohit, Amit C; Patel, Vatsal M; Rajani, Dhanji P; Moo-Puc, Rosa; Lopez-Cedillo, Julio Cesar; Nogueda-Torres, Benjamin; Rivera, Gildardo

    2017-09-01

    A new series of N-(substituted-phenyl)-2-[5-(quinoxalin-2-yloxymethyl)-[1,3,4] oxadiazol-2-ylsulfanyl]-acetamides (5a-o) was designed and synthesised from the parent compound 2-hydroxy quinoxaline (1) through a multistep reaction sequence and was characterised by spectral and elemental analyses. All of the compounds synthesised were evaluated for their antimicrobial and antiprotozoal activities. The results revealed that quinoxaline-based 1,3,4-oxadiazoles displayed promising antibacterial, antifungal and anti-Trypanosoma cruzi activities compared with reference drugs, particularly the lead compound 5l in a short-term in vivo model in T. cruzi. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  20. Design, synthesis, conformational and molecular docking study of some novel acyl hydrazone based molecular hybrids as antimalarial and antimicrobial agents.

    Science.gov (United States)

    Kumar, Parvin; Kadyan, Kulbir; Duhan, Meenakshi; Sindhu, Jayant; Singh, Vineeta; Saharan, Baljeet Singh

    2017-11-14

    Acyl hydrazones are an important class of heterocyclic compounds promising pharmacological characteristics. Malaria is a life-threatening mosquito-borne blood disease caused by a plasmodium parasite. In some places, malaria can be treated and controlled with early diagnosis. However, some countries lack the resources to do this effectively. The present work involves the design and synthesis of some novel acyl hydrazone based molecular hybrids of 1,4-dihydropyridine and pyrazole (5a-g). These molecular hybrids were synthesised by condensation of 1,4-dihydropyridin-4-yl-phenoxyacetohydrazides with differently substituted pyrazole carbaldehyde. The final compound (5) showed two conformations (the major, E, s-cis and the minor, E, s-trans) as revealed by NMR spectral data and further supported by the energy calculations (MOPAC2016 using PM7 method). All the synthesised compounds were screened for their in vitro antimalarial activities against chloroquine-sensitive malaria parasite Plasmodium falciparum (3D7) and antimicrobial activity against Gram positive bacteria i.e. Bacillus cereus, Gram negative bacteria i.e. Escherichia coli and antifungal activity against one yeast i.e. Aspergillus niger. All these compounds were found more potent than chloroquine and clotrimazole, the standard drugs. In vitro antiplasmodial IC 50 value of the most potent compound 5d was found to be 4.40 nM which is even less than all the three reference drugs chloroquine (18.7 nM), pyrimethamine (11 nM) and artimisinin (6 nM). In silico binding study of compound 5d with plasmodial cysteine protease falcipain-2 indicated the inhibition of falcipain-2 as the probable reason for the antimalarial potency of compound 5d. All the compounds had shown good to excellent antimicrobial and antifungal activities.

  1. Lipooligosaccharide structure is an important determinant in the resistance of Neisseria gonorrhoeae to antimicrobial agents of innate host defense

    Directory of Open Access Journals (Sweden)

    Jacqueline T Balthazar

    2011-02-01

    Full Text Available The strict human pathogen Neisseria gonorrhoeae has caused the sexually transmitted infection termed gonorrhea for thousands of years. Over the millennia, the gonococcus has likely evolved mechanisms to evade host defense systems that operate on the genital mucosal surfaces in both males and females. Past research has shown that the presence or modification of certain cell envelope structures can significantly impact levels of gonococcal susceptibility to host-derived antimicrobial compounds that bathe genital mucosal surfaces and participate in innate host defense against invading pathogens. In order to facilitate the identification of gonococcal genes that are important in determining levels of bacterial susceptibility to mediators of innate host defense, we used the Himar I mariner in vitro mutagenesis system to construct a transposon insertion library in strain F62. As proof of principle that this strategy would be suitable for this purpose, we screened the library for mutants expressing decreased susceptibility to the bacteriolytic action of normal human serum (NHS. We found that a transposon insertion in the lgtD gene, which encodes an N-acetylgalactosamine transferase involved in the extension of the α-chain of lipooligosaccharide (LOS, could confer decreased susceptibility of strain F62 to complement-mediated killing by NHS. By complementation and chemical analyses, we demonstrated both linkage of the transposon insertion to the NHS-resistance phenotype and chemical changes in LOS structure that resulted from loss of LgtD production. Further truncation of the LOS α-chain or loss of phosphoethanolamine (PEA from the lipid A region of LOS also impacted levels of NHS-resistance. PEA decoration of lipid A also increased gonococcal resistance to the model cationic antimicrobial polymyxin B. Taken together, we conclude that the Himar I mariner in vitro mutagenesis procedure can facilitate studies on structures involved in gonococcal

  2. Characterization of Essential Oils Obtained from Abruzzo Autochthonous Plants: Antioxidant and Antimicrobial Activities Assessment for Food Application

    Science.gov (United States)

    Pellegrini, Marika; Chaves-López, Clemencia; Mazzarrino, Giovanni; D’Amato, Serena; Lo Sterzo, Claudio

    2018-01-01

    In the present study, the essential oils (EOs) of some officinal plants from Abruzzo territory (Italy) were evaluated for their antimicrobial and antioxidant activities and their volatile fraction chemical characterization. The EOs were extracted from Rosmarinus officinalis, Origanum vulgare, Salvia officinalis, Mentha piperita, Allium sativum, Foeniculum vulgare, Satureja montana, Thymus vulgaris and Coriandrum sativum seeds. The antimicrobial activity was screened against thirteen Gram-positive and Gram-negative strains to determine the Minimal Inhibitory Concentration (MIC). The total phenolic content (TPC) and the antioxidant capacity (AOC) were assessed by means of Folin-Ciocâlteu method, and Trolox Equivalent Antioxidant Capacity with 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (TEAC/ABTS), Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays respectively. Among the nine EOs tested, T. vulgaris, S. montana, O. vulgare and C. sativum EOs showed MIC values ranging from 0.625 to 5 μL/mL. The AOC and TPC results for these species were also interesting. The major components for these EOs were thymol for T. vulgaris (44%) and O. vulgare (40%), linalool (77%) for C. sativum, and carvacrol for S. montana (54%). The results allowed the study to establish that these EOs are good candidates for potential application as biopreservatives in foods and/or food manufacture environments. PMID:29393893

  3. Characterization of Essential Oils Obtained from Abruzzo Autochthonous Plants: Antioxidant and Antimicrobial Activities Assessment for Food Application

    Directory of Open Access Journals (Sweden)

    Marika Pellegrini

    2018-02-01

    Full Text Available In the present study, the essential oils (EOs of some officinal plants from Abruzzo territory (Italy were evaluated for their antimicrobial and antioxidant activities and their volatile fraction chemical characterization. The EOs were extracted from Rosmarinus officinalis, Origanum vulgare, Salvia officinalis, Mentha piperita, Allium sativum, Foeniculum vulgare, Satureja montana, Thymus vulgaris and Coriandrum sativum seeds. The antimicrobial activity was screened against thirteen Gram-positive and Gram-negative strains to determine the Minimal Inhibitory Concentration (MIC. The total phenolic content (TPC and the antioxidant capacity (AOC were assessed by means of Folin-Ciocâlteu method, and Trolox Equivalent Antioxidant Capacity with 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (TEAC/ABTS, Ferric Reducing Antioxidant Power (FRAP and 2,2-diphenyl-1-picrylhydrazyl (DPPH assays respectively. Among the nine EOs tested, T. vulgaris, S. montana, O. vulgare and C. sativum EOs showed MIC values ranging from 0.625 to 5 μL/mL. The AOC and TPC results for these species were also interesting. The major components for these EOs were thymol for T. vulgaris (44% and O. vulgare (40%, linalool (77% for C. sativum, and carvacrol for S. montana (54%. The results allowed the study to establish that these EOs are good candidates for potential application as biopreservatives in foods and/or food manufacture environments.

  4. Uptake of Plutonium-238 into Solanum tuberosum L. (potato plants) in presence of complexing agent EDTA.

    Science.gov (United States)

    Tawussi, Frank; Gupta, Dharmendra K; Mühr-Ebert, Elena L; Schneider, Stephanie; Bister, Stefan; Walther, Clemens

    2017-11-01

    Bioavailability and plant uptake of radionuclides depend on various factors. Transfer into different plant parts depends on chemical and physical processes, which need to be known for realistic ingestion dose modelling when these plants are used for food. Within the scope of the present work, the plutonium uptake by potato plants (Solanum tuberosum L.) was investigated in hydroponic solution of low concentration [Pu] = 10 -9  mol L -1 . Particular attention was paid to the speciation of radionuclides in the solution which was modelled by the speciation code PHREEQC. The speciation, the solubility and therefore the plant availability of radionuclides mainly depend on the pH value and the redox potential of the solution. During the contamination period, the redox potential did not change significantly. In contrast, the pH value showed characteristic changes depending on exudates excreted by the plants. Plant roots took up high amounts of plutonium (37%-50% of the added total amount). In addition to the uptake into the roots, the radionuclides can also adsorb to the exterior root surface. The solution-to-plant transfer factor showed values between 0.03 and 0.80 (Bq kg -1 / Bq L -1 ) for the potato tubers. By addition of the complexing agent EDTA (10 -4  mol L-1), the plutonium uptake from solution increased by 58% in tubers and by 155% in shoots/leaves. The results showed that excreted substances by plants affect bioavailability of radionuclides at low concentration, on the one hand. On the other hand, the uptake of plutonium by roots and the accumulation in different plant parts can lead to non-negligible ingestion doses, even at low concentration. We are aware of the limited transferability of data obtained in hydroponic solutions to plants growing in soil. However, the aim of this study is twofold: First we want to investigate the influence of Pu speciation on plant uptake in a rather well defined system which can be modelled using available thermodynamic data

  5. AROMA PROFILE AND ANTIMICROBIAL PROPERTIES OF ALCOHOLIC AND AQUEOUS EXTRACTS FROM ROOT, LEAF AND STALK OF NETTLE (Urtica dioica L.)

    OpenAIRE

    Razzagh Mahmoudi; Kiumars Amini; Omid Fakhri; Mahsa Alem

    2014-01-01

    Medicinal plant can be considered as a great source of new antimicrobial agents due to their enormous therapeutic potential and limited side effects. Nettle (Urtica dioica L.) is a widespread and common medicinal plant widely used in traditional medicine. The present study investigates the antimicrobial potency of alcoholic and aqueous extracts of Urtica dioica on some gram positive and negative bacteria and also a particular type of fungi and analyzes the extracts to find the active ingredie...

  6. Glycosides from Medicinal Plants as Potential Anticancer Agents: Emerging Trends towards Future Drugs.

    Science.gov (United States)

    Khan, Haroon; Saeedi, Mina; Nabavi, Seyed Mohammad; Mubarak, Mohammad S; Bishayee, Anupam

    2018-04-03

    Cancer continues to be a global burden, despite the advancement of various technological and pharmaceutical improvements over the past two decades. Methods for treating cancer include surgery, radiotherapy and chemotherapy in addition to other specialized techniques. On the other hand, medicinal plants have been traditionally employed either as the complementary medicine or dietary agents in the treatment and management of cancer. Medicinal plants are a rich source of secondary metabolites with interesting biological and pharmacological activities. Among these metabolites, glycosides are naturally occurring substances and have outstanding therapeutic potential and clinical utility. Different medical research engines such GoogleScholar, PubMed, SpringerLink, ScienceDirect were used to collect related literature on the subject matter. In this regard, only peer reviewed journals were considered. Emerging results showed that numerous glycosides isolated from various plants possessed marked anticancer activity against a variety of cancer cell lines. Accordingly, the aim of the present review is to shed light on the anticancer effects of glycosides, analyze possible mechanisms of action, and highlight the role of these natural agents as complementary and alternative medicine in combating and managing cancer. The glycosides isolated from different plants demonstrated potent cytotoxic effects against various cancer cell lines in initial preclinical studies. The anticancer effect was mediated through multiple mechanisms; however further detail studies are needed to understand the full potential of glycosides for clinical utility. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. An antimicrobial evaluation of plants used for the treatment of respiratory infections in rural Maputaland, KwaZulu-Natal, South Africa.

    Science.gov (United States)

    York, T; van Vuuren, S F; de Wet, H

    2012-10-31

    Abundant availability of medicinal plants in the study area offers low cost health care, but scientific validation is needed in order to lend credibility to the traditional use against respiratory infections. This study focussed on determining the antimicrobial efficacies of 30 plant species (independently and in various combinations) used for respiratory related infections in rural Maputaland. In vitro minimum inhibitory concentration (MIC) assays were undertaken on dichloromethane-methanol (CH(2)Cl(2): MeOH) and aqueous extracts, as well as the hydro-distilled essential oils (for aromatic plants). Selected plant parts were assessed for antimicrobial activity against a range of respiratory pathogens i.e. Cryptococcus neoformans (ATCC 14116), Klebsiella pneumoniae (ATCC 13883), Moraxella catarrhalis (ATCC 23246), Mycobacterium smegmatis (ATCC 14468) and Staphylococcus aureus (ATCC 6538). The sum of the fractional inhibitory concentrations (∑FIC) was determined for plants traditionally used in combination. Isobolograms represent MIC values for a selection of interactions where two plants were combined in various ratios. The most antimicrobially active aqueous extracts were that of Ozoroa obovata and Sclerocarya birrea (0.10 mg/ml) while organic extracts from Parinari capensis subsp. incohata and Tetradenia riparia demonstrated the most noteworthy (0.03 mg/ml) activity. Although both Lippia javanica and Eucalyptus grandis were by far the most popular plants traditionally used for respiratory infections, the antimicrobial activity was mostly only moderate. Furthermore, the traditional use in a 1:1 combination did not display strong antimicrobial interactions, but isobolograms demonstrate (against some test organisms) that when combined in various ratios, predominant additive interactions are evident where E. grandis was present in larger proportions. The combination of E. grandis with O. obovata demonstrated synergism against both C. neoformans and K. pneumoniae

  8. Phenotypic and genomic characterization of the antimicrobial producer Rheinheimera sp. EpRS3 isolated from the medicinal plant Echinacea purpurea: insights into its biotechnological relevance.

    Science.gov (United States)

    Presta, Luana; Bosi, Emanuele; Fondi, Marco; Maida, Isabel; Perrin, Elena; Miceli, Elisangela; Maggini, Valentina; Bogani, Patrizia; Firenzuoli, Fabio; Di Pilato, Vincenzo; Rossolini, Gian Maria; Mengoni, Alessio; Fani, Renato

    2017-04-01

    In recent years, there has been increasing interest in plant microbiota; however, despite medicinal plant relevance, very little is known about their highly complex endophytic communities. In this work, we report on the genomic and phenotypic characterization of the antimicrobial compound producer Rheinheimera sp. EpRS3, a bacterial strain isolated from the rhizospheric soil of the medicinal plant Echinacea purpurea. In particular, EpRS3 is able to inhibit growth of different bacterial pathogens (Bcc, Acinetobacter baumannii, and Klebsiella pneumoniae) which might be related to the presence of gene clusters involved in the biosynthesis of different types of secondary metabolites. The outcomes presented in this work highlight the fact that the strain possesses huge biotechnological potential; indeed, it also shows antimicrobial effects upon well-described multidrug-resistant (MDR) human pathogens, and it affects plant root elongation and morphology, mimicking indole acetic acid (IAA) action. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  9. Antimicrobial activity of four medicinal plants widely used in Persian folk medicine

    Directory of Open Access Journals (Sweden)

    A. Hamedi

    2015-12-01

    Full Text Available Background and objectives: Commiphora habessinica (O.Berg Engl. (Burseraceae, Boswellia sacra Flueck (Burseraceae, Phoenix dactylifera L. (Arecaceae, and Doronicum glaciale (Wulfen Nyman (Asteraceae are of ethnomedicinal importance in Persian folk medicine and are widely used to treat infectious diseases. The aim of the present study was to investigate the antimicrobial properties of these herbal medicines to prevent misadministration. Methods: Antifungal and antibacterial (Gram-positive and Gram-negative activities of the petroleum ether, dichloromethane and ethanol fractions obtained from oleo-gum-resin of C. habessinica and B. sacra, spathe of P. dactylifera and roots of D. glaciale were evaluated against standard species and clinical antibiotic resistant isolates using broth microdilution method. The fractions were tested at concentrations of 0.5 to 256 µg/mL.Results: The petroleum ether fraction of C. habessinica oleo-gum-resin exhibited the most anti-Candida activity with MIC50 of 0.5-16 µg/mL. The growth of C. glabrata and C. tropicalis was inhibited by the ethanol fraction of C. habessinica oleo-gum-resin with MIC50 of 1-16 μg/mL. C. glabrata was the most susceptible species. Among the tested fractions, only the petroleum ether fraction of C. habessinica oleo-gum-resin had an inhibitory effect on Aspergillus spp. with a MIC50 of 8-32 µg/mL. None of the fractions exhibited antimicrobial activity against the Gram-positive and Gram-negative bacteria at concentrations of 0.5 to 256 µg/mL. Conclusions: The sensitivity of fungi and bacteria to natural antimicrobials varies widely within species and it is essential to consider the sensitivity of the strains to prevent resistance.

  10. The precision and robustness of published protocols for disc diffusion assays of antimicrobial agent susceptibility: an inter-laboratory study

    DEFF Research Database (Denmark)

    Gabhainn, S.N.; Bergh, Ø.; Dixon, B.

    2004-01-01

    for each agent being 11.1%. Significant influences on zone size were detected for all three parameters of the protocol. Media source effects were particularly notable with respect to oxytetracycline and oxolinic acid discs, disc source effects with respect to ampicillin and sulphamethoxazole...

  11. Biological screening of some Turkish medicinal plant extracts for antimicrobial and toxicity activities.

    Science.gov (United States)

    Turker, A U; Usta, C

    2008-01-20

    Screening of antibacterial activity and toxicity of 22 aqueous plant extracts from 17 Turkish plants was conducted. Antibacterial activity was performed with six bacteria including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Staphylococcus epidermidis. Extracts of Tussilago farfara leaves, Helichyrsum plicatum flowers, Solanum dulcamara aerial parts and Urtica dioica leaves gave the best inhibitory activity against S. pyogenes, S. aureus and S. epidermidis. Of the 22 plant extracts, 20 extracts displayed toxicity (LC50 was plant extracts. Also, the most inhibitive plant extract for seed germination was obtained with S. dulcamara aerial parts.

  12. Susceptibilidad a antimicrobianos en aislamientos de Streptococcus pneumoniae invasor en Colombia Susceptibility to antimicrobial agents in isolates of invasive Streptococcus pneumoniae in Colombia

    Directory of Open Access Journals (Sweden)

    Aura Lucía Leal

    1999-03-01

    Full Text Available Se realizó un estudio para determinar los patrones de susceptibilidad a los antimicrobianos de los aislamientos de Streptococcus pneumoniae causante de enfermedad invasora diagnosticada en Colombia en niños menores de 5 años entre 1994 y 1996 y para establecer la distribución de los tipos capsulares de los aislamientos resistentes. Se analizaron 324 aislamientos recuperados durante la ejecución del Protocolo Nacional de Serotipificación de S. pneumoniae realizado en Santa Fe de Bogotá, Medellín y Cali, Colombia, entre julio de 1994 y marzo de 1996. Se observó que 119 de todos los aislamientos (36,7% presentaban susceptibilidad disminuida por lo menos a un antimicrobiano, que 39 (12% presentaban susceptibilidad disminuida a la penicilina y que de estos últimos aislamientos, 29 presentaban resistencia intermedia y 10 resistencia alta. Nueve aislamientos (2,8% presentaban resistencia a la ceftriaxona, 80 (24,7% a la combinación de trimetoprima y sulfametoxazol (TMS, 49 (15,1% al cloranfenicol y 31 (9,6% a la eritromicina. Se observó resistencia a dos antimicrobianos en 31 aislamientos (9,6% y multirresistencia en 22 (6,7%. Estos 22 aislamientos mostraron resistencia al TMS. Las asociaciones más frecuentes fueron penicilina, TMS y eritromicina en 5 casos; penicilina, cloranfenicol, TMS y eritromicina en 4; penicilina, ceftriaxona, cloranfenicol y TMS en 3; y penicilina, ceftriaxona, cloranfenicol, TMS y eritromicina en 3 casos. Los serotipos más frecuentes en los aislamientos resistentes a la penicilina fueron: 23F (53,8%, 14 (25,6%, 6B (7,7%, 9V (5,1%, 19F (5,1% y 34 (2,6%. Los serotipos más frecuentes en los aislamientos resistentes a antimicrobianos distintos de la penicilina fueron: 5 (37,5%, 23F (7,5%, 14 (18,8% y 6B (13,8%. Esta diferencia en la distribución de los serotipos fue estadísticamente significativa (P A study was done to determine the patterns of susceptibility to antimicrobial agents in isolates of Streptococcus

  13. Effects of gamma irradiation of the 60 Co on antimicrobial action of plant extracts of bark and leaves of Schinus terebinthifolius Raddi

    International Nuclear Information System (INIS)

    Silva, Edvane Borges da; Santos, Gustavo Henrique Farias dos; Amaral, Ademir de Jesus; Xisto, Kesia; Araujo, Rosilma de Oliveira

    2014-01-01

    This study aimed to evaluate the potential for antimicrobial activity in vitro of extracts of bark and leaves of S. terebinthifolius treated with 60 Co gamma radiation. 5,0 doses were used; 7.5 and 10 kGy, being held non-irradiated controls. To determine the antimicrobial activity was applied to the disc diffusion technique to evaluate the diameter of the inhibition zones against Gram-positive bacteria, gram-negative bacteria, alcohol-acid-resistant and yeast. Antimicrobial activity was considered significant for halos ≥ 15 mm. The results indicate an intensification of antimicrobial action of bark extracts, the 5.0 kGy, against S. aureus. Was held the micro dilution in broth to determine the minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC) of peels extracts, compared to eight clinical isolates of S. aureus. The MBC values showed that ionizing radiation did not produce the increased of anti bacteriostatic action of S. terebinthifolius, but the results indicated that S. terebinthifolius bark extracts can be used as an antimicrobial agent and ionizing radiation as an important alternative in this conservation feature

  14. Evaluation of the antimicrobial potential of two flavonoids isolated from limnophila plants.

    Science.gov (United States)

    Brahmachari, Goutam; Mandal, Narayan C; Jash, Shyamal K; Roy, Rajiv; Mandal, Lalan C; Mukhopadhyay, Arijit; Behera, Biswajit; Majhi, Sasadhar; Mondal, Avijit; Gangopadhyay, Arindam

    2011-06-01

    The antimicrobial potential of two bioflavonoids, i.e., 5,7-dihydroxy-4',6,8-trimethoxyflavone (1) and 5,6-dihydroxy-4',7,8-trimethoxyflavone (2), isolated from Limnophila heterophylla Benth. and L. indica (Linn.) Druce (Scrophulariaceae), respectively, were evaluated against the microbial strains Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Alternaria solani, and Candida albicans. Compounds 1 and 2 exhibited moderate but broad antimicrobial activities against both Gram-positive and Gram-negative bacteria and also against the fungal pathogens. Moreover, the mechanism of action of 1 and 2 on the cellular functions or structures of some of the microorganisms was studied. Compound 1 showed a bactericidal effect against E. coli and S. aureus (MICs of 200 and 250 μg/ml, resp.), while compound 2 was found to effectively kill B. subtilis by cell lysis. The growth of A. solani and C. albicans was inhibited by compounds 1 and 2, respectively. The effects of the flavonoids on the cellular structures and the carbohydrate metabolic pathways were studied by scanning electron microscopy (SEM) of the treated cells and by assessing the specific activity of key enzymes of the pathways, respectively. At sublethal doses, they enhanced the activity of gluconeogenic fructose bisphosphatase, but decreased the activity of phosphofructokinase and isocitrate dehydrogenase, the key enzymes of the EmbdenMeyerhofParnas pathway and the tricarboxylic acid cycle, respectively. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  15. Isolation, diversity, and antimicrobial activity of rare actinobacteria from medicinal plants of tropical rain forests in Xishuangbanna, China.

    Science.gov (United States)

    Qin, Sheng; Li, Jie; Chen, Hua-Hong; Zhao, Guo-Zhen; Zhu, Wen-Yong; Jiang, Cheng-Lin; Xu, Li-Hua; Li, Wen-Jun

    2009-10-01

    Endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. Xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. However, little is known about the endophytic actinobacteria of this tropical area. In this work, we studied the diversity of actinobacteria isolated from medicinal plants collected from tropical rain forests in Xishuangbanna. By the use of different selective isolation media and methods, a total of 2,174 actinobacteria were isolated. Forty-six isolates were selected on the basis of their morphologies on different media and were further characterized by 16S rRNA gene sequencing. The results showed an unexpected level of diversity, with 32 different genera. To our knowledge, this is the first report describing the isolation of Saccharopolyspora, Dietzia, Blastococcus, Dactylosporangium, Promicromonospora, Oerskovia, Actinocorallia, and Jiangella species from endophytic environments. At least 19 isolates are considered novel taxa by our current research. In addition, all 46 isolates were tested for antimicrobial activity and were screened for the presence of genes encoding polyketide synthetases and nonribosomal peptide synthetases. The results confirm that the medicinal plants of Xishuangbanna represent an extremely rich reservoir for the isolation of a significant diversity of actinobacteria, including novel species, that are potential sources for the discovery of biologically active compounds.

  16. The phenotypic and genotypic characteristics of antibiotic resistance in Escherichia coli populations isolated from farm animals with different exposure to antimicrobial agents.

    Science.gov (United States)

    Mazurek, Justyna; Pusz, Paweł; Bok, Ewa; Stosik, Michał; Baldy-Chudzik, Katarzyna

    2013-01-01

    The aim of the study was to determine the influence of the presence or the absence of antibiotic input on the emergence and maintenance of resistance in commensal bacteria from food producing animals. The research material constituted E. coli isolates from two animal species: swine at different age from one conventional pig farm with antibiotic input in young pigs and from beef and dairy cattle originated from organic breeding farm. The sensitivity to 16 antimicrobial agents was tested, and the presence of 15 resistance genes was examined. In E. coli from swine, the most prevalent resistance was resistance to streptomycin (88.3%), co-trimoxazole (78.8%), tetracycline (57.3%) ampicillin (49.3%) and doxycycline (44.9%) with multiple resistance in the majority. The most commonly observed resistance genes were: bla(TEM) (45.2%), tetA (35.8%), aadA1 (35.0%), sul3 (29.5%), dfrA1 (20.4%). Differences in phenotypes and genotypes of E. coli between young swine undergoing prevention program and the older ones without the antibiotic pressure occurred. A disparate resistance was found in E. coli from cattle: cephalothin (36.9%), cefuroxime (18.9%), doxycycline (8.2%), nitrofurantoin (7.7%), and concerned mainly dairy cows. Among isolates from cattle, multidrug resistance was outnumbered by resistance to one or two antibiotics and the only found gene markers were: bla(SHV), (3.4%), tetA (1.29%), bla(TEM) (0.43%) and tetC (0.43%). The presented outcomes provide evidence that antimicrobial pressure contributes to resistance development, and enteric microflora constitutes an essential reservoir of resistance genes.

  17. In vitro susceptibility testing to antimicrobial agents of urinary tract infection bacteria in women: a 5-year retrospective study

    Directory of Open Access Journals (Sweden)

    Laura Melgarejo

    2017-06-01

    Full Text Available Introduction: The growing resistance rates of urinary pathogens represent a serious problem. The aim of this study was to analyze the etiology of community-acquired urinary tract infections, their first-line antimicrobial resistance and the presence of extended-spectrum beta-lactamases (ESBL in gram negative bacilli. Methods: The study was conducted between January 2011 and December 2015 using data from the Microbiology Laboratory at the teaching hospital Hospital de Clínicas, which belongs to the National University of Asunción. Results: A total of 1957 urinary pathogens were found in women. Escherichia coli was the most commonly isolated bacterium (57%, followed by Klebsiella pneumoniae (11% and Streptococcus agalactiae (2%, Staphylococcus saprophyticus (2% and Proteus mirabilis (2%. The resistance rates of Escherichia coli were the following: to trimetoprim-sulfametoxazol, 43%; to ciprofloxacin, 32%; to ampicilin/sulbactam, 32%; to cefotaxime, 13 %; to piperacillin/tazobactam, 8%; nitrofurantoin, 2%, whereas it did not show resistance to meropenem during this period. Extended-spectrum beta-lactamases were produced by 11% of the E. coli isolates and 30% of the Klebsiella pneumoniae isolates. Conclusions: The resistance and cross-resistance rates found in this study pose a serious problem which compels the continuous assessment of the empirical therapy for urinary tract infections at this hospital.

  18. Atividade antimicrobiana in vitro de produtos vegetais em otite externa aguda In vitro antimicrobial activity of plants in Acute Otitis Externa

    Directory of Open Access Journals (Sweden)

    Janaina Cândida Rodrigues Nogueira

    2008-02-01

    Full Text Available Otite externa aguda é a inflamação do conduto auditivo externo, e plantas medicinais podem ser utilizadas, na cultura popular, para seu tratamento. OBJETIVO: Avaliar atividade antimicrobiana in vitro de Aleolanthus suaveolens, Caryophyllus aromaticus, Cymbopogon citratus, Matricaria chamomila, Pithecellobium avaremotemo, Plectranthus amboinicus e Ruta graveolens sobre agentes etiológicos de otite externa. CASUÍSTICA E MÉTODOS: A concentração inibitória mínima de extratos e óleos destas plantas foi obtida em amostras de otite externa. RESULTADOS: Staphylococcus aureus em 10 culturas, Pseudomonas aeruginosa em 8, Pseudomonas aeruginosa e Staphylococcus aureus, em associação, em 5 culturas e Candida albicans e Candida krusei em 4 culturas. P. aeruginosa foi resistente a todos os extratos e óleos essenciais testados; os extratos de A. suaveolens, P. avaremotemo e de R. graveolens foram inativos, o óleo essencial de C. aromaticus e M. chamomila foram ativos contra 3 cepas de S. aureus e as cepas de Candida; Sete das cepas de S. aureus foram sensíveis ao extrato de P. amboinicus, mas o óleo não mostrou atividade, 4 cepas de S.aureus e as cepas de Candida foram sensíveis ao óleo essencial de R. graveolens. CONCLUSÃO: Algumas plantas apresentaram resultados satisfatórios, dependendo do agente etiológico, porém se faz necessário estudos mais detalhados, para melhorar o aproveitamento destas plantas.Acute Otitis Externa is an inflammation of the outer auditory meatus, and according to popular saying, medicinal plant extracts can be used in its treatment. AIM: to assess the in vitro antimicrobial activity of the following plants: Aleolanthus suaveolens; Caryophyllus aromaticus; Cymbopogon citratus; Matricaria chamomila; Pithecellobium avaremotemo; Plectranthus amboinicus and Ruta graveolens on the germs that cause otitis externa. MATERIALS AND METHODS: the minimum inhibitory concentration of extracts and oils from these plants was