WorldWideScience

Sample records for antimicrobial agents

  1. Fluoroquinolone antimicrobial agents.

    OpenAIRE

    Wolfson, J S; Hooper, D C

    1989-01-01

    The fluoroquinolones, a new class of potent orally absorbed antimicrobial agents, are reviewed, considering structure, mechanisms of action and resistance, spectrum, variables affecting activity in vitro, pharmacokinetic properties, clinical efficacy, emergence of resistance, and tolerability. The primary bacterial target is the enzyme deoxyribonucleic acid gyrase. Bacterial resistance occurs by chromosomal mutations altering deoxyribonucleic acid gyrase and decreasing drug permeation. The dr...

  2. IRANIAN MEDICINAL PLANTS AS ANTIMICROBIAL AGENTS

    OpenAIRE

    Mohaddese Mahboubi

    2013-01-01

    Resistance of human and food spoilage pathogens to antimicrobial agents and the side effects of chemical agents or preservative for human is caused for finding natural new antimicrobial agents, especially among the medicinal plants. This review introduces the methods that are used for antimicrobial evaluations and synergistic activities and the antimicrobial potential of some Iranian medicinal plants.

  3. Ruthenium complexes as antimicrobial agents.

    Science.gov (United States)

    Li, Fangfei; Collins, J Grant; Keene, F Richard

    2015-04-21

    One of the major advances in medical science has been the development of antimicrobials; however, a consequence of their widespread use has been the emergence of drug-resistant populations of microorganisms. There is clearly a need for the development of new antimicrobials--but more importantly, there is the need for the development of new classes of antimicrobials, rather than drugs based upon analogues of known scaffolds. Due to the success of the platinum anticancer agents, there has been considerable interest in the development of therapeutic agents based upon other transition metals--and in particular ruthenium(II/III) complexes, due to their well known interaction with DNA. There have been many studies of the anticancer properties and cellular localisation of a range of ruthenium complexes in eukaryotic cells over the last decade. However, only very recently has there been significant interest in their antimicrobial properties. This review highlights the types of ruthenium complexes that have exhibited significant antimicrobial activity and discusses the relationship between chemical structure and biological processing--including site(s) of intracellular accumulation--of the ruthenium complexes in both bacterial and eukaryotic cells.

  4. Topical antimicrobial agents in ophthalmology. A review

    Directory of Open Access Journals (Sweden)

    E. V. Dovgan’

    2014-01-01

    Full Text Available The data on different antimicrobial agents (fluoroquinolones, minoglycosides, macrolides, fusidic acid, chloramphenicol and their activity against various microorganisms are reviewed. The findings from different researchers are analyzed. Considerable attention is devoted to the problem of antimicrobial resistance in ophthalmology. Pharmacokinetics of topical antimicrobial agents applied in ophthalmology, their safety and tolerability are described. The indications for topical antimicrobial agents use in ophthalmology approved in Russian Federation are presented. With regard for pharmacokinetics and pharmacodynamics, safety profile and good tolerability, it is concluded that fluoroquinolones are medication of choice for empirical antimicrobial treatment in ophthalmology.

  5. Animal venoms as antimicrobial agents.

    Science.gov (United States)

    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.

  6. 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

  7. Antimicrobial Agents and Catheter Complications in Outpatient Parenteral Antimicrobial Therapy.

    Science.gov (United States)

    Keller, Sara C; Dzintars, Kathryn; Gorski, Lisa A; Williams, Deborah; Cosgrove, Sara E

    2018-03-01

    Debate about whether certain antimicrobial agents traditionally considered vesicants increase the risk of catheter complications has led to uncertainty in venous catheter placement protocols. To understand whether patients requiring home-based outpatient parenteral antimicrobial therapy (OPAT) should receive peripheral catheters (e.g., midline catheters) versus central venous catheters, and to understand whether certain antimicrobial agents place home-based OPAT patients at higher risk for catheter complications, we investigated associations between antimicrobial agent(s) and catheter complications. We performed a prospective cohort study of patients requiring home-based OPAT discharged from two urban tertiary care academic medical centers, including telephone surveys and chart abstractions. Multivariable Poisson regressions were used to evaluate: (i) associations between antimicrobial agents traditionally considered vesicants, based on pH or osmolarity, and catheter complication rates, and (ii) associations between antimicrobial agent and rates of catheter complications. Vesicant antimicrobials defined using pH or osmolarity criteria were not associated with an increased rate of catheter complications (adjusted incidence rate ratio [aIRR]: 1.63, 95% confidence interval [CI]: 0.89-2.96). Vancomycin was associated with an increased rate of catheter complications, as was daptomycin (aIRR: 2.32 [95% CI: 1.20-4.46] and 4.45 [95% CI: 1.02-19.41], respectively). Staphylococcus aureus infections were also associated with an increased rate of catheter complications (aIRR: 2.13, 95% CI: 1.09-4.19), as were midline catheters (aIRR: 9.44, 95% CI: 2.12-41.97). Our study supports recent guidance identifying vancomycin as a vesicant, among a subset of antimicrobial agents, and removal of pH criteria for identification of vesicants. © 2018 Pharmacotherapy Publications, Inc.

  8. Plant Products as Antimicrobial Agents

    Science.gov (United States)

    Cowan, Marjorie Murphy

    1999-01-01

    The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and “leads” which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations. PMID:10515903

  9. Efflux pump inhibitors (EPIs) as new antimicrobial agents against ...

    African Journals Online (AJOL)

    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 ...

  10. Prodigiosin - A Multifaceted Escherichia coli Antimicrobial Agent.

    Directory of Open Access Journals (Sweden)

    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.

  11. Resistencia bacteriana Bacterial resistance to antimicrobial agents

    Directory of Open Access Journals (Sweden)

    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.

  12. Use of antimicrobial agents in aquaculture.

    Science.gov (United States)

    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.

  13. 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. Mohammad A Ghattas, Nermin A Eissa, Sanaa K Bardaweel, Abdallah Abu Mellal, Noor Atatreh ...

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    Intensive use of antimicrobial agents in aquaculture provides a selective pressure creating reservoirs of drug-resistant bacteria and transferable resistance genes in fish pathogens and other bacteria in the aquatic environment. From these reservoirs, resistance genes may disseminate by horizonta...... 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....

  15. 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....

  16. Controlled fermentation of kimchi using naturally occurring antimicrobial agents.

    Science.gov (United States)

    Kim, Jinsol; Bang, Jihyun; Beuchat, Larry R; Kim, Hoikyung; Ryu, Jee-Hoon

    2012-10-01

    Kimchi is a traditional Korean fermented food. Since it ferments continuously during distribution and storage, the extension of shelf life by preventing over-acidification is a major concern in the kimchi industry. One of the most frequently attempted ways to delay fermentation is to add naturally occurring antimicrobial agents. Many researchers have investigated ways to delay over-acidification by adding minor ingredients, fruits or fruit seed extracts, extracts of medicinal herbs, culinary herbs and spices, and other miscellaneous substances to kimchi. The addition of naturally occurring antimicrobial agents may enhance the acceptability of kimchi to consumers over a longer period of time but may also have a disadvantage in that it may cause changes in sensory quality, especially if added in large amounts. To avoid undesirable sensory changes, application of hurdle technologies (i.e., multifactor preservative systems) which involve using combinations of low amounts of various naturally occurring antimicrobial agents as ingredients should be explored with the goal of controlling fermentation. If synergistic or additive antimicrobial effects can be achieved using small amounts of a combination of natural agents, changes in sensory qualities will be minimized, thereby prolonging shelf life. Research findings summarized in this review provide a basis for developing effective hurdle technologies using naturally occurring antimicrobial agents to extend shelf life of kimchi and perhaps other types of traditional fermented foods. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. 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.

  18. Plant essential oils as active antimicrobial agents.

    Science.gov (United States)

    Seow, Yi Xin; Yeo, Chia Rou; Chung, Hui Ling; Yuk, Hyun-Gyun

    2014-01-01

    Essential oils derived from plants have been recognized for decades to exhibit biological activities, including antioxidant, anticancer, and antimicrobial attributes. Antimicrobial activities of these natural plant materials have been intensively explored in recent years, mainly in response to the overwhelming concern of consumers over the safety of synthetic food additives. Gram-negative organisms are believed to be slightly less sensitive to essential oils than Gram-positive bacteria. Generally, a higher concentration is required to obtain the same efficacy in foods than in synthetic media. The combinations of different types of essential oils or with other food additives have been found to potentially exhibit synergistic if not additive effects. This suggests a cost-efficient and wholesome alternative to both food industry and consumers, at the same time adhering to the hurdle technology in inhibiting proliferation of foodborne pathogens. This review aims to examine the conventional methods commonly used for assessment of antimicrobial activities of essential oils and phytochemicals, the use of these substances as antimicrobials in food products, factors that affect their efficacy, synergism between components or with available food preservatives as well as the challenges and future directions of using essential oils and phytochemicals as natural food preservatives.

  19. Amino acid–based surfactants: New antimicrobial agents.

    Science.gov (United States)

    Pinazo, A; Manresa, M A; Marques, A M; Bustelo, M; Espuny, M J; Pérez, L

    2016-02-01

    The rapid increase of drug resistant bacteria makes necessary the development of new antimicrobial agents. Synthetic amino acid-based surfactants constitute a promising alternative to conventional antimicrobial compounds given that they can be prepared from renewable raw materials. In this review, we discuss the structural features that promote antimicrobial activity of amino acid-based surfactants. Monocatenary, dicatenary and gemini surfactants that contain different amino acids on the polar head and show activity against bacteria are revised. The synthesis and basic physico-chemical properties have also been included.

  20. 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

  1. 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 b......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...

  2. Antimicrobial agents - optimising the ecological balance.

    Science.gov (United States)

    Woon, Sze-Ann; Fisher, Dale

    2016-08-05

    There is no more challenging a group of pharmaceuticals than antimicrobials. With the antibiotic era came great optimism as countless deaths were prevented from what were previously fatal conditions. Although antimicrobial resistance was quickly identified, the abundance of antibiotics entering the market helped cement attitudes of arrogance as the "battle against pestilence appeared won". Opposite emotions soon followed as many heralded the return of the pre-antibiotic era, suggesting that the "antibiotic pipeline had dried up" and that our existing armament would soon be rendered worthless. In reality, humans overrate their ecological importance. For millions of years there has been a balance between factors promoting bacterial survival and those disturbing it. The first half century of the "antibiotic era" was characterised by a cavalier attitude disturbing the natural balance; however, recent efforts have been made through several mechanisms to respond and re-strengthen the antimicrobial armament. Such mechanisms include a variety of incentives, educational efforts and negotiations. Today, there are many more "man-made" factors that will determine a new balance or state of ecological harmony. Antibiotics are not a panacea nor will they ever be inutile. New resistance mechanisms will be identified and new antibiotics will be discovered, but most importantly, we must optimise our application of these extraordinary "biological tools"; therein lays our greatest challenge - creating a society that understands and respects the determinants of the effectiveness of antibiotics.

  3. 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.

  4. 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.

  5. Pathogenic Bacteria and their Susceptibility to Antimicrobial Agents ...

    African Journals Online (AJOL)

    Background: Antibiotic-resistant Gram negative bacteria are increasingly emerging as serious causes of infections than ever before. Materials and Methods: This retrospective study examined the pattern of pathogenic bacterial isolates and their susceptibilities to antimicrobial agents at Abouzar Children Hospital, Ahavz-Iran ...

  6. Prospects of Nanostructure Materials and Their Composites as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Anupriya Baranwal

    2018-03-01

    Full Text Available Nanostructured materials (NSMs have increasingly been used as a substitute for antibiotics and additives in various products to impart microbicidal effect. In particular, use of silver nanoparticles (AgNPs has garnered huge researchers' attention as potent bactericidal agent due to the inherent antimicrobial property of the silver metal. Moreover, other nanomaterials (carbon nanotubes, fullerenes, graphene, chitosan, etc. have also been studied for their antimicrobial effects in order ensure their application in widespread domains. The present review exclusively emphasizes on materials that possess antimicrobial activity in nanoscale range and describes their various modes of antimicrobial action. It also entails broad classification of NSMs along with their application in various fields. For instance, use of AgNPs in consumer products, gold nanoparticles (AuNPs in drug delivery. Likewise, use of zinc oxide nanoparticles (ZnO-NPs and titanium dioxide nanoparticles (TiO2-NPs as additives in consumer merchandises and nanoscale chitosan (NCH in medical products and wastewater treatment. Furthermore, this review briefly discusses the current scenario of antimicrobial nanostructured materials (aNSMs, limitations of current research and their future prospects. To put various perceptive insights on the recent advancements of such antimicrobials, an extended table is incorporated, which describes effect of NSMs of different dimensions on test microorganisms along with their potential widespread applications.

  7. Antimicrobial Peptides as Infection Imaging Agents: Better Than Radiolabeled Antibiotics

    Directory of Open Access Journals (Sweden)

    Muammad Saeed Akhtar

    2012-01-01

    Full Text Available Nuclear medicine imaging techniques offer whole body imaging for localization of number and site of infective foci inspite of limitation of spatial resolution. The innate human immune system contains a large member of important elements including antimicrobial peptides to combat any form of infection. However, development of antibiotics against bacteria progressed rapidly and gained popularity over antimicrobial peptides but even powerful antimicrobials failed to reduce morbidity and mortality due to emergence of mutant strains of bacteria resulting in antimicrobial resistance. Differentiation between infection and inflammation using radiolabeled compounds with nuclear medicine techniques has always been a dilemma which is still to be resolved. Starting from nonspecific tracers to specific radiolabeled tracers, the question is still unanswered. Specific radiolabeled tracers included antibiotics and antimicrobial peptides which bind directly to the bacteria for efficient localization with advanced nuclear medicine equipments. However, there are merits and demerits attributed to each. In the current paper, radiolabeled antibiotics and radiolabeled peptides for infection localization have been discussed starting with the background of primitive nonspecific tracers. Radiolabeled antimicrobial peptides have certain merits compared with labeled antibiotics which make them superior agents for localization of infective focus.

  8. 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.

  9. 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.

  10. High-throughput platform for rapid deployment of antimicrobial agents.

    Science.gov (United States)

    Svarovsky, Sergei A; Gonzalez-Moa, Maria J

    2011-11-14

    A new approach to conducting bacterial binding assays by using an addressable high density random sequence peptide microarray is described. When bacterial binding is carried out in the presence of a competing excess of corresponding bacterial lipopolysaccharide (LPS), most of the observed bacterial binding is inhibited, suggesting that LPS is the major target of the bacterial binding peptides. Importantly, the amino acid composition of the selected peptides closely resembles the composition of natural antimicrobial peptides. Conjugation of selected peptides to polyvalent nanoparticle scaffold yields constructs that show potent antibacterial agglutination activities. The system is general enough to potentially create antimicrobial agents to virtually any pathogen.

  11. Novel isoquinoline derivatives as antimicrobial agents.

    Science.gov (United States)

    Galán, Abraham; Moreno, Laura; Párraga, Javier; Serrano, Ángel; Sanz, Ma Jesús; Cortes, Diego; Cabedo, Nuria

    2013-06-01

    The wide variety of potent biological activities of natural and synthetic isoquinoline alkaloids encouraged us to develop novel antimicrobial isoquinoline compounds. We synthesized a variety of differently functionalized 1-pentyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines (THIQs), including dihydroisoquinolinium salts (2 and 5), methyl pentanoate-THIQ (6), 1-pentanol-THIQ (7), ester derivatives (8-15) and carbamate derivatives (16-23). We employed classic intramolecular Bischler-Napieralski cyclodehydration to generate the isoquinoline core. All the structures were characterized by nuclear magnetic resonance and mass spectrometry. The bactericide and fungicide activities were evaluated for all the synthesized compounds and structure-activity relationships were established. Many compounds exhibited high and broad-range bactericidal activity. Fluorophenylpropanoate ester 13 and the halogenated phenyl- (17, 18) and phenethyl carbamates (21, 22) exerted the most remarkable bactericidal activity. However, few compounds displayed antifungal activity against most of the fungi tested. Among them, chlorinated derivatives like chlorobenzoate and chlorophenylpropanoate esters (10 and 14, respectively) and chlorophenethyl carbamate 22, exhibited the greatest antifungal activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Systemic anti-microbial agents used in periodontal therapy.

    Science.gov (United States)

    Patil, Vishakha; Mali, Rohini; Mali, Amita

    2013-03-01

    Periodontitis is an infectious disease with marked inflammatory response, leading to destruction of underlying tissues. The aim of periodontal therapy is to eradicate the pathogens associated with the disease and attain periodontal health. This is achieved by non-surgical and surgical therapy; however, mechanical debridement and topical application of antiseptics may not be helpful in all cases. In such cases, adjunctive systemic antibiotic therapy remains the treatment of choice. It can reach micro-organisms at the base of the deep periodontal pockets and furcation areas via serum, and also affect organisms residing within gingival epithelium and connective tissue. Before advising any anti-microbial agent, it is necessary to have knowledge of that agent. The aim of this review article is to provide basic details of each systemic anti-microbial agent used in periodontal therapy. The points discussed are its mode of action, susceptible periodontal pathogens, dosage, its use in treatment of periodontal disease, and mechanism of bacterial resistance to each anti-microbial agent. It might be of some help while prescribing these drugs.

  14. 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.

  15. Resistance of Streptococcus sanguis biofilms to antimicrobial agents

    DEFF Research Database (Denmark)

    Larsen, T; Fiehn, N E

    1996-01-01

    Bacteria living in biofilms as dental plaque on tooth surfaces are generally more resistant to antimicrobial agents than bacteria in batch culture normally used for in vitro susceptibility testing. In order to compare the resistance of free-living and surface-grown oral bacteria, the MIC of Strep......Bacteria living in biofilms as dental plaque on tooth surfaces are generally more resistant to antimicrobial agents than bacteria in batch culture normally used for in vitro susceptibility testing. In order to compare the resistance of free-living and surface-grown oral bacteria, the MIC...... 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...... gradually decreased. Chlorhexidine also gradually reduced biofilm cell number, but was inhibitory at concentrations closer to the MIC than was the case for the antibiotics. Thus S. sanguis in biofilms survived up to 500 times the MIC found in batch culture for up to 48 h....

  16. Development of non-natural flavanones as antimicrobial agents.

    Directory of Open Access Journals (Sweden)

    Zachary L Fowler

    Full Text Available With growing concerns over multidrug resistance microorganisms, particularly strains of bacteria and fungi, evolving to become resistant to the antimicrobial agents used against them, the identification of new molecular targets becomes paramount for novel treatment options. Recently, the use of new treatments containing multiple active ingredients has been shown to increase the effectiveness of existing molecules for some infections, often with these added compounds enabling the transport of a toxic molecule into the infecting species. Flavonoids are among the most abundant plant secondary metabolites and have been shown to have natural abilities as microbial deterrents and anti-infection agents in plants. Combining these ideas we first sought to investigate the potency of natural flavonoids in the presence of efflux pump inhibitors to limit Escherichia coli growth. Then we used the natural flavonoid scaffold to synthesize non-natural flavanone molecules and further evaluate their antimicrobial efficacy on Escherichia coli, Bacillus subtilis and the fungal pathogens Cryptococcus neoformans and Aspergillus fumigatus. Of those screened, we identified the synthetic molecule 4-chloro-flavanone as the most potent antimicrobial compound with a MIC value of 70 µg/mL in E. coli when combined with the inhibitor Phe-Arg-ß-naphthylamide, and MICs of 30 µg/mL in S. cerevesiae and 30 µg/mL in C. neoformans when used alone. Through this study we have demonstrated that combinatorial synthesis of non-natural flavonones can identify novel antimicrobial agents with activity against bacteria and fungi but with minimal toxicity to human cells.

  17. Development of non-natural flavanones as antimicrobial agents.

    Science.gov (United States)

    Fowler, Zachary L; Shah, Karan; Panepinto, John C; Jacobs, Amy; Koffas, Mattheos A G

    2011-01-01

    With growing concerns over multidrug resistance microorganisms, particularly strains of bacteria and fungi, evolving to become resistant to the antimicrobial agents used against them, the identification of new molecular targets becomes paramount for novel treatment options. Recently, the use of new treatments containing multiple active ingredients has been shown to increase the effectiveness of existing molecules for some infections, often with these added compounds enabling the transport of a toxic molecule into the infecting species. Flavonoids are among the most abundant plant secondary metabolites and have been shown to have natural abilities as microbial deterrents and anti-infection agents in plants. Combining these ideas we first sought to investigate the potency of natural flavonoids in the presence of efflux pump inhibitors to limit Escherichia coli growth. Then we used the natural flavonoid scaffold to synthesize non-natural flavanone molecules and further evaluate their antimicrobial efficacy on Escherichia coli, Bacillus subtilis and the fungal pathogens Cryptococcus neoformans and Aspergillus fumigatus. Of those screened, we identified the synthetic molecule 4-chloro-flavanone as the most potent antimicrobial compound with a MIC value of 70 µg/mL in E. coli when combined with the inhibitor Phe-Arg-ß-naphthylamide, and MICs of 30 µg/mL in S. cerevesiae and 30 µg/mL in C. neoformans when used alone. Through this study we have demonstrated that combinatorial synthesis of non-natural flavonones can identify novel antimicrobial agents with activity against bacteria and fungi but with minimal toxicity to human cells.

  18. Synthesis, Antimicrobial, and Computational Evaluation of Novel Isobutylchalcones as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Afzal Basha Shaik

    2017-01-01

    Full Text Available A series of 25 new chalcones were synthesized by Claisen-Schmidt condensation, well characterized by spectroscopic data, and evaluated for their antibacterial and antifungal activities by serial tube dilution method. Among the compounds tested, A3 and A6 containing 2,4-dichlorophenyl and 2,4-difluorophenyl moiety, respectively, were found to be the most potent in the series against both bacterial and fungal strains with a MIC value of 16 µg/mL in each case. Further computational evaluation for antimicrobial activity was performed by atom based 3D-QSAR using PHASE™ software in order to have a correlation between the observed activities and predicted activities. The computational studies were in agreement with the in vitro antimicrobial results and had identified the most promising chalcones as antimicrobial agents and the responsible structural features for the proposed activity.

  19. Peptidomimetics as a new generation of antimicrobial agents: current progress

    Directory of Open Access Journals (Sweden)

    Méndez-Samperio P

    2014-08-01

    Full Text Available Patricia Méndez-Samperio Department of Immunology, National School of Biological Sciences, National Polytechnic Institute, Mexico City, Mexico Abstract: Antibiotic resistance is an increasing public health concern around the world. Rapid increase in the emergence of multidrug-resistant bacteria has been the target of extensive research efforts to develop a novel class of antibiotics. Antimicrobial peptides (AMPs are small cationic amphiphilic peptides, which play an important role in the defense against bacterial infections through disruption of their membranes. They have been regarded as a potential source of future antibiotics, owing to a remarkable set of advantageous properties such as broad-spectrum activity, and they do not readily induce drug-resistance. However, AMPs have some intrinsic drawbacks, such as susceptibility to enzymatic degradation, toxicity, and high production cost. Currently, a new class of AMPs termed "peptidomimetics" have been developed, which can mimic the bactericidal mechanism of AMPs, while being stable to enzymatic degradation and displaying potent activity against multidrug-resistant bacteria. This review will focus on current findings of antimicrobial peptidomimetics. The potential future directions in the development of more potent analogs of peptidomimetics as a new generation of antimicrobial agents are also presented. Keywords: drug resistance, infection, antimicrobial peptides

  20. Essential oil nanoemulsions as antimicrobial agents in food.

    Science.gov (United States)

    Donsì, Francesco; Ferrari, Giovanna

    2016-09-10

    The crescent interest in the use of essential oils (EOs) as natural antimicrobials and preservatives in the food industry has been driven in the last years by the growing consumers' demand for natural products with improved microbial safety, and fresh-like organoleptic properties. Nanoemulsions efficiently contribute to support the use of EOs in foods by increasing their dispersibility in the food areas where microorganisms grow and proliferate, by reducing the impact on the quality attributes of the product, as well as by enhancing their antimicrobial activity. Understanding how nanoemulsions intervene on the mass transfer of EOs to the cell membrane and on the mechanism of antimicrobial action will support the engineering of more effective delivery systems and foster the application of EOs in real food systems. This review focuses on the enabling contribution of nanoemulsions to the use of EOs as natural preservative agents in food, (a) specifically addressing the formulation and fabrication of stable EO nanoemulsions, (b) critically analyzing the reported antimicrobial activity data, both in vitro and in product, to infer the impact of the delivery system on the mechanisms of action of EOs, as well as (c) discussing the regulatory issues associated with their use in food systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Mono- and combined antimicrobial agents efficiency in experimental wound infection

    Directory of Open Access Journals (Sweden)

    Наталія Ігорівна Філімонова

    2015-10-01

    Full Text Available Modern problems of antibiotic therapy are shown by wide range of side effects, both on organism and microbiological levels: the spread of allergies, toxic for organ systems reactions, dysbiosis development, and resistant pathogens formation and dissemination. Therefore the necessity of search for new effective drugs with significant antimicrobial activity applied for the wounds treatment arises. Development of combined remedies on the background of different origin antimicrobial agents’ derivatives is one of the fight directions against infectious diseases in the skin pathology. Recently among the existing antimicrobial agents one should focus on antiseptic drugs, due to degenerative and dysfunctional effect on microbial cell.Aim of research. The comparison of mono- and combined antimicrobial agents chemotherapeutic efficiency in the treatment of localized purulent infection under experimental conditions.Metods. The study of chemotherapeutic efficiency was carried out on the model of localized purulent Staphylococcus infection on albino mice weighting 14 – 16 g. S.aureus ATCC 25923 strains were used as infectious agents. The contamination was performed subcutaneously to the right side of mice’s skin after depilation. The animals were randomly divided into 4 groups: the 1st group – infected mice without treatment (control; the 2nd group – infected mice treated with a ciprofloxacin; the 3rd group – infected mice treated with a Ciprofloxacin and Decamethoxin combination; the 4th group – infected mice treated with a combined drug on the base of mutual prodrugs (Hexamethylenetetramine and Phenyl salicylate.Results. The efficiency of mono- and combined antimicrobial agents under experimental Staphylococcus wound infection conditions was studied. It was found that localized purulent staph center was formed more slowly in comparison with control and mono preparation use (2nd group of animals. The average index of skin lesions in comparison

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  4. Comparisons of Halogenated β-Nitrostyrenes as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Hugh Cornell

    2014-08-01

    Full Text Available The influence of three types of halogen-substituted E-β-methyl-β-nitrostyrenes (such as Compounds B, D, H to overcome bacterial activity that is currently a significant health threat was studied. The evaluations of their bio-potency was measured and related to their structure and activity relationships for the purposes of serving to inhibit and overcoming resistant microorganisms. In particular, fluorine-containing β-nitrostyrenes were found to be highly active antimicrobial agents. The addition of the β-bromo group enhanced the antibacterial activity significantly. Our work has illustrated that halogen substituents at both the 4-position in the aromatic ring and also at the β-position on the alkene side chain of nitropropenyl arenes enhanced the antimicrobial activity of these compounds.

  5. Synthetic cationic amphiphilic α-helical peptides as antimicrobial agents.

    Science.gov (United States)

    Wiradharma, Nikken; Khoe, Ulung; Hauser, Charlotte A E; Seow, See Voon; Zhang, Shuguang; Yang, Yi-Yan

    2011-03-01

    Antimicrobial peptides (AMPs) secreted by the innate immune system are prevalent as the effective first-line of defense to overcome recurring microbial invasions. They have been widely accepted as the blueprints for the development of new antimicrobial agents for the treatment of drug resistant infections. However, there is also a growing concern that AMPs with a sequence that is too close to the host organism's AMP may inevitably compromise its own natural defense. In this study, we design a series of synthetic (non-natural) short α-helical AMPs to expand the arsenal of the AMP families and to gain further insights on their antimicrobial activities. These cationic and amphiphilic peptides have a general sequence of (XXYY)(n) (X: hydrophobic residue, Y: cationic residue, and n: the number of repeat units), and are designed to mimic the folding behavior of the naturally-occurring α-helical AMPs. The synthetic α-helical AMPs with 3 repeat units, (FFRR)(3), (LLRR)(3), and (LLKK)(3), are found to be more selective towards microbial cells than rat red blood cells, with minimum inhibitory concentration (MIC) values that are more than 10 times lower than their 50% hemolytic concentrations (HC(50)). They are effective against Gram-positive B. subtilis and yeast C. albicans; and the studies using scanning electron microscopy (SEM) have elucidated that these peptides possess membrane-lytic activities against microbial cells. Furthermore, non-specific immune stimulation assays of a typical peptide shows negligible IFN-α, IFN-γ, and TNF-α inductions in human peripheral blood mononuclear cells, which implies additional safety aspects of the peptide for both systemic and topical use. Therefore, the peptides designed in this study can be promising antimicrobial agents against the frequently-encountered Gram-positive bacteria- or yeast-induced infections. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. 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.

  7. Interactions of antimicrobial compounds with cross-linking agents of alginate dressings.

    Science.gov (United States)

    Goh, Cheong Hian; Heng, Paul Wan Sia; Huang, Esther Pei En; Li, Benny Kai Hui; Chan, Lai Wah

    2008-07-01

    The aim of this study was to investigate the antimicrobial activities of calcium ions and other cross-linking agents of alginate dressings, as well as their compatibility with commonly used topical antimicrobials. The antimicrobial activities of cross-linking agents and antimicrobials (five antibiotics and four antiseptics) were evaluated by the broth dilution method. The interactions between individual cross-linking agents and antimicrobials were evaluated using the chequerboard test against common skin pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. From the MIC determined, antibiotics were the most active, followed by the antiseptics and cross-linking agents. Calcium ions, which are commonly used to cross-link alginate, exhibited very weak antimicrobial activity and higher fractional inhibitory concentration than the other cross-linking agents. The use of calcium and gentamicin resulted in antagonism against S. aureus. In contrast, aluminium, zinc and copper ions exhibited higher antimicrobial activities but insignificant interactions with the antimicrobials. Commonly used topical antimicrobials that are active against the skin pathogens S. aureus and P. aeruginosa could be potentially incompatible with calcium alginate dressings. Copper, zinc and aluminium ions are more suitable cross-linking agents for alginate as they do not show antagonism with the antimicrobials and could impart antimicrobial property to the resultant dressing.

  8. 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.

  9. [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.

  10. Resistance of Streptococcus sanguis biofilms to antimicrobial agents

    DEFF Research Database (Denmark)

    Larsen, T; Fiehn, N E

    1996-01-01

    Bacteria living in biofilms as dental plaque on tooth surfaces are generally more resistant to antimicrobial agents than bacteria in batch culture normally used for in vitro susceptibility testing. In order to compare the resistance of free-living and surface-grown oral bacteria, the MIC......, and biofilm cell number was determined during this period. The antibiotics at the MIC did not affect the cell number of S. sanguis biofilms compared to the starting point, and only after 48 h at 500 times the MIC were the biofilm bacteria eliminated. At intermediate concentrations biofilm cell number...... gradually decreased. Chlorhexidine also gradually reduced biofilm cell number, but was inhibitory at concentrations closer to the MIC than was the case for the antibiotics. Thus S. sanguis in biofilms survived up to 500 times the MIC found in batch culture for up to 48 h....

  11. 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

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

    OpenAIRE

    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 m...

  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. In-Vitro efficacy of antimicrobial agents used in the treatment of ...

    African Journals Online (AJOL)

    Failure to cure eye infections, and reduced potency in topical antimicrobials had been observed in South Western Nigeria, this study sought to evaluate in vitro, the efficacy of antimicrobial agents in the treatment of ocular infections. A total of 46 ocular bacterial isolates were recovered from the diagnostic laboratory of the ...

  15. SUSCEPTIBILY OF Aeromonar hydrophylla BACTERIA ISOLATED FROM UNHEALTHY BAUNG FISH (Mystus nemurus TOWARDS ANTIMICROBIAL AGENTS

    Directory of Open Access Journals (Sweden)

    Pipik Taufik

    2010-06-01

    Full Text Available The susceptibility of Aeromonas hydrophila isolated from ikan baung (Mystus nemurus to antimicrobial agents was carried out. The objective of study is to know the kind of antimicrobial agents for the control aeromonasis  of Mystus nemurus. Tryptic soy agar (TSA plate consisted 106 cells/plate of A. hydrophila on its surface was kept paper disk consisted antimicrobial agent, than incubated on 30 0C for 24 hours. The results showed that from 10 isolates to be tested, 5 isolates were resistant, 2 isolates were intermediate and 3 isolates were sensitive to tetracycline and chloramphenicol respectively; one isolate was resistant, 6 isolates were intermediate and 2 isolates were sensitive to nalidixic acid. Minimal in hibitory concentration (MIC of tetracycline and chlorampenicol to the sensitive isolates were 0.5 ppm respectively.   Keywords: The susceptibility, Aeromonas hydrophila, antimicrobial agents

  16. 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...

  17. In vitro susceptibility of Campylobacter jejuni from Kuwait to tigecycline & other antimicrobial agents

    Directory of Open Access Journals (Sweden)

    M John Albert

    2013-01-01

    Full Text Available Background & objectives: There is an increasing frequency of resistance of Campylobacter jejuni to antimicrobial agents making treatment difficult. In this study, the in vitro susceptibility of C. jejuni isolates collected over an eight year period was tested against tigecycline, a glycylcycline, the previously tested antimicrobial agents in Kuwait, ciprofloxacin, erythromycin and tetracycline, and other antimicrobial agents not previously tested in Kuwait, amoxicillin-clavulanic acid, gentamicin, imipenem and meropenem. Methods: A total of 97 C. jejuni isolates from diarrhoeal stools of Kuwaiti patients during 2002-2010 were studied for susceptibility to the above antimicrobial agents by E test. Results: Erythromycin resistance increased from 5.0 per cent in 2002-2003 to 13.8 per cent in 2007-2010. The figures for ciprofloxacin resistance for the same periods were 53 and 65.5 per cent, respectively. Tetracycline resistance increased from 40.0 per cent in 2003-2006 to 62.1 per cent in 2007-2010 (P=0.05. However, all isolates were uniformly susceptible to tigecycline and other antimicrobial agents. Interpretation & conclusions: There was a progressive increase in the prevalence of resistance to ciprofloxacin, erythromycin and tetracycline. As all isolates were uniformly susceptible to tigecycline, this antimicrobial agent can be considered as a potential candidate for treatment in clinical studies.

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

    Science.gov (United States)

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

    2012-08-01

    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.

  19. Antimicrobial agents for preventing peritonitis in peritoneal dialysis patients.

    Science.gov (United States)

    Campbell, Denise; Mudge, David W; Craig, Jonathan C; Johnson, David W; Tong, Allison; Strippoli, Giovanni Fm

    2017-04-08

    Peritoneal dialysis (PD) is an important therapy for patients with end-stage kidney disease and is used in more than 200,000 such patients globally. However, its value is often limited by the development of infections such as peritonitis and exit-site and tunnel infections. Multiple strategies have been developed to reduce the risk of peritonitis including antibiotics, topical disinfectants to the exit site and antifungal agents. However, the effectiveness of these strategies has been variable and are based on a small number of randomised controlled trials (RCTs). The optimal preventive strategies to reduce the occurrence of peritonitis remain unclear.This is an update of a Cochrane review first published in 2004. To evaluate the benefits and harms of antimicrobial strategies used to prevent peritonitis in PD patients. We searched the Cochrane Kidney and Transplant's Specialised Register to 4 October 2016 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. RCTs or quasi-RCTs in patients receiving chronic PD, which evaluated any antimicrobial agents used systemically or locally to prevent peritonitis or exit-site/tunnel infection were included. Two authors independently assessed risk of bias and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratio (RR) with 95% confidence intervals (CI). Thirty-nine studies, randomising 4435 patients, were included. Twenty additional studies have been included in this update. The risk of bias domains were often unclear or high; risk of bias was judged to be low in 19 (49%) studies for random sequence generation, 12 (31%) studies for

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

    DEFF Research Database (Denmark)

    Kumburu, Happiness Houka; Sonda, Tolbert; Mmbaga, Blandina Theophil

    2017-01-01

    Objective To determine the causative agents of infections and their antimicrobial susceptibility at a tertiary care hospital in Moshi, Tanzania, to guide optimal treatment. Methods 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 disk diffusion was used to determine the antimicrobial susceptibility pattern of the bacteria isolates. Results A total of 249 (42.2%) specimens were culture-positive yielding...... 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...

  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...... of pathogenic bacteria more difficult. Furthermore, it has been suggested that use of biocides may contribute to the development of resistance in bacteria to antimicrobial agents used in human and animal therapy. So far, it is evident that cross- and co-resistance mechanisms to antimicrobials agents...... and biocides exist. However, much less is known about the potential effect of biocides on development of antimicrobial resistance in bacteria by promoting the horizontal transfer of resistance genes or by inducing the mutation rate. Even though biocides are commonly used at working concentrations way above...

  2. assessment of commonly available antimicrobial agents. a study ...

    African Journals Online (AJOL)

    But the most dangerous counterfeits are the imitation medicines sold to unwitting consumers.5. METHODOLOGY. The disc diffusion method was used for the determination of antimicrobial activities. MATERIALS. Apparatus used: Universal bottles, incubator, autoclave, Petri dishes, flasks, pipettes, Bunsen burner,.

  3. Recent advances in screening of natural products for antimicrobial agents.

    Science.gov (United States)

    Zhou, Meng; Luo, Hao; Li, Zhi; Wu, Feng; Huang, Canhua; Ding, Zhenyu; Li, Rui

    2012-05-01

    It has been a very long history for human to resist diseases. During this period, a large number of drugs that could kill or inhibit the growth of microbe has been discovered, most of which were natural products. However, there may still be a large amount of antimicrobial medicines in natural compounds which have not been found yet. The ways of screening for antimicrobial always cost a long time and need a lot of manpower before. However, in recent years, a lot of new antimicrobial targets, antimicrobial drugs and screening methods which are simpler, faster and more efficient have been invented. In this paper the newly discovered targets, natural products and representative technologies were reviewed, which were expected to make some contributions to the research and development of medicines.

  4. Natural resins and bioactive natural products thereof as potential antimicrobial agents.

    Science.gov (United States)

    Termentzi, Aikaterini; Fokialakis, Nikolas; Skaltsounis, Alexios Leandros

    2011-01-01

    Natural products and their derivatives have historically been invaluable as a source of therapeutic agents and have contributed to the discovery of antimicrobial agents. However, today with the development of drug-resistant strains, new scaffolds and new sources of bioactive compounds are needed. To this end, plant derived natural resins are reviewed for their potential application as antimicrobial agents. Natural gums, extracts of the whole resins, as well as specific extracts, fractions, essential oils and isolated compounds from the above resins are discussed in terms of their antifungal, antibacterial, and antiprotozoal activity.

  5. Ethyl Pyruvate: An Anti-Microbial Agent that Selectively Targets Pathobionts and Biofilms.

    Science.gov (United States)

    Debebe, Tewodros; Krüger, Monika; Huse, Klaus; Kacza, Johannes; Mühlberg, Katja; König, Brigitte; Birkenmeier, Gerd

    The microbiota has a strong influence on health and disease in humans. A causative shift favoring pathobionts is strongly linked to diseases. Therefore, anti-microbial agents selectively targeting potential pathogens as well as their biofilms are urgently demanded. Here we demonstrate the impact of ethyl pyruvate, so far known as ROS scavenger and anti-inflammatory agent, on planktonic microbes and biofilms. Ethyl pyruvate combats preferably the growth of pathobionts belonging to bacteria and fungi independent of the genera and prevailing drug resistance. Surprisingly, this anti-microbial agent preserves symbionts like Lactobacillus species. Moreover, ethyl pyruvate prevents the formation of biofilms and promotes matured biofilms dissolution. This potentially new anti-microbial and anti-biofilm agent could have a tremendous positive impact on human, veterinary medicine and technical industry as well.

  6. Ethyl Pyruvate: An Anti-Microbial Agent that Selectively Targets Pathobionts and Biofilms.

    Directory of Open Access Journals (Sweden)

    Tewodros Debebe

    Full Text Available The microbiota has a strong influence on health and disease in humans. A causative shift favoring pathobionts is strongly linked to diseases. Therefore, anti-microbial agents selectively targeting potential pathogens as well as their biofilms are urgently demanded. Here we demonstrate the impact of ethyl pyruvate, so far known as ROS scavenger and anti-inflammatory agent, on planktonic microbes and biofilms. Ethyl pyruvate combats preferably the growth of pathobionts belonging to bacteria and fungi independent of the genera and prevailing drug resistance. Surprisingly, this anti-microbial agent preserves symbionts like Lactobacillus species. Moreover, ethyl pyruvate prevents the formation of biofilms and promotes matured biofilms dissolution. This potentially new anti-microbial and anti-biofilm agent could have a tremendous positive impact on human, veterinary medicine and technical industry as well.

  7. IQ-motif peptides as novel anti-microbial agents.

    Science.gov (United States)

    McLean, Denise T F; Lundy, Fionnuala T; Timson, David J

    2013-04-01

    The IQ-motif is an amphipathic, often positively charged, α-helical, calmodulin binding sequence found in a number of eukaryote signalling, transport and cytoskeletal proteins. They share common biophysical characteristics with established, cationic α-helical antimicrobial peptides, such as the human cathelicidin LL-37. Therefore, we tested eight peptides encoding the sequences of IQ-motifs derived from the human cytoskeletal scaffolding proteins IQGAP2 and IQGAP3. Some of these peptides were able to inhibit the growth of Escherichia coli and Staphylococcus aureus with minimal inhibitory concentrations (MIC) comparable to LL-37. In addition some IQ-motifs had activity against the fungus Candida albicans. This antimicrobial activity is combined with low haemolytic activity (comparable to, or lower than, that of LL-37). Those IQ-motifs with anti-microbial activity tended to be able to bind to lipopolysaccharide. Some of these were also able to permeabilise the cell membranes of both Gram positive and Gram negative bacteria. These results demonstrate that IQ-motifs are viable lead sequences for the identification and optimisation of novel anti-microbial peptides. Thus, further investigation of the anti-microbial properties of this diverse group of sequences is merited. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  8. Anthocyanins as antimicrobial agents of natural plant origin.

    Science.gov (United States)

    Cisowska, Agnieszka; Wojnicz, Dorota; Hendrich, Andrzej B

    2011-01-01

    Anthocyanins are particularly abundant in different fruits, especially in berries. The beneficial effects of these compounds for human health have been known from at least the 16th century. Despite the great number of papers devoted to the different biological effects exerted by anthocyanins only a limited number of studies is focused on the antimicrobial activity of these compounds. Anthocyanin content of berry fruits varies from 7.5 mg/100 mg fresh fruit in redcurrant (Ribes rubum) up to 460 mg/100 g fresh fruit in chokeberry (Aronia melanocarpa). After consumption, anthocyanins are intensively metabolized, mainly in the intestines and liver. Glucorination, methylation and sulfation are the most typical metabolic reactions. Antimicrobial activity of crude extracts of plant phenolic compounds against human pathogens has been intensively studied to characterize and develop new healthy food ingredients as well as medical and pharmaceutical products. However, there is very little information available about the antimicrobial activity of the pure anthocyanins. In the last part of this review we present the collection of papers describing the anthocyanin profiles of different fruits (mainly berries) and the antimicrobial properties of the identified compounds. Generally, anthocyanins are active against different microbes, however Gram-positive bacteria usually are more susceptible to the anthocyanin action than Gram-negative ones. Mechanisms underlying anthocyanin activity include both membrane and intracellular interactions of these compounds. Antimicrobial activity of berries and other anthocyanin-containing fruits is likely to be caused by multiple mechanisms and synergies because they contain various compounds including anthocyanins, weak organic acids, phenolic acids, and their mixtures of different chemical forms. Therefore, the antimicrobial effect of chemically complex compounds has to be critically analyzed.

  9. [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.

  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. Use of silica supports for enhancing the stability of folates and developing antimicrobial agents

    OpenAIRE

    Ruiz Rico, María

    2017-01-01

    The present PhD thesis, entitled "Use of silica supports for enhancing the stability of folates and developing antimicrobial agents", focuses on the development and evaluation of new smart systems based on the use of silica nano- and microparticles as inorganic supports for the encapsulation or immobilization of two compounds types of interest to the food industry: vitamins and antimicrobials. The first chapter shows the effect of encapsulation of folic acid and 5-formyltetrahydrofolate i...

  12. 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.

  13. In vitro activity of certain antimicrobial agents in combination with ...

    African Journals Online (AJOL)

    The ability of methicillin-resistant Staphycoccus aureus to acquire resistance to most antibiotics is a worldwide concern that necessitated the study of the antimicrobial activity of the medicinal plant Augouardia lestestii alone and in combination with existing antibiotics. The minimum inhibitory concentration was determined ...

  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. 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

  16. 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...

  17. Pharmacokinetic parameters explain the therapeutic activity of antimicrobial agents in a silkworm infection model.

    Science.gov (United States)

    Paudel, Atmika; Panthee, Suresh; Urai, Makoto; Hamamoto, Hiroshi; Ohwada, Tomohiko; Sekimizu, Kazuhisa

    2018-01-25

    Poor pharmacokinetic parameters are a major reason for the lack of therapeutic activity of some drug candidates. Determining the pharmacokinetic parameters of drug candidates at an early stage of development requires an inexpensive animal model with few associated ethical issues. In this study, we used the silkworm infection model to perform structure-activity relationship studies of an antimicrobial agent, GPI0039, a novel nitrofuran dichloro-benzyl ester, and successfully identified compound 5, a nitrothiophene dichloro-benzyl ester, as a potent antimicrobial agent with superior therapeutic activity in the silkworm infection model. Further, we compared the pharmacokinetic parameters of compound 5 with a nitrothiophene benzyl ester lacking chlorine, compound 7, that exerted similar antimicrobial activity but had less therapeutic activity in silkworms, and examined the metabolism of these antimicrobial agents in human liver fractions in vitro. Compound 5 had appropriate pharmacokinetic parameters, such as an adequate half-life, slow clearance, large area under the curve, low volume of distribution, and long mean residence time, compared with compound 7, and was slowly metabolized by human liver fractions. These findings suggest that the therapeutic effectiveness of an antimicrobial agent in the silkworms reflects appropriate pharmacokinetic properties.

  18. 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.

  19. 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...... 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Utilization of antimicrobial agents with and without prescription by out-patients in selected pharmacies in South-eastern Nigeria.

    Science.gov (United States)

    Esimone, Charles Okey; Nworu, Chukwuemeka Sylvester; Udeogaranya, Obinna Patrick

    2007-12-01

    We conducted a study in out-patient pharmacies in South-eastern Nigeria in order to determine the extent of self-medication of antimicrobial agents in this area, assess the dosing error associated with this practice and to ascertain the extent of involvement of community pharmacies. A survey was carried out daily in selected community pharmacies for a period of 90 days. Data were collected on the number of patients visiting these shops for antimicrobial agents, the number getting their medication with a prescription, the number getting their order without prescription and on the type and dose of antimicrobial agents received. MAIN OUT-COME MEASURE: The percentage of patients with prescription and without prescription was compared. The percentage under-dosages or over-dosages associated with how each antimicrobial agent was obtained were compared. The total DDDs of antimicrobial agents dispensed within this period with and without prescription were compared. A total of 4,128 outpatients visited the shops for antimicrobial agents within the period and were involved in the study. Of this number, 1,742 (42.2%) came with a prescription from qualified medical personnel and 2,386 (57.8%) came without a prescription. A total of 13,693.13 DDDs of antimicrobial agents was dispensed, of which 56.38% was dispensed with prescription and 43.62% was dispensed without prescription. The degrees of under-dosing were significantly (P better regulation of antimicrobial agents dispensing and utilization in the region.

  2. Comparative evaluation Of Topical Antimicrobial Agents In Healing Lacerated Wounds In Children

    Directory of Open Access Journals (Sweden)

    Parhate S.M

    1996-01-01

    Full Text Available Various topical anti-microbial agents are used for lacerated wounds. The reports on the efficacy of these agents in healing the wounds are not comprehensive. This study reviews the results of seven topical antimicrobial agents applied under sterile occlusive dressing of superficial lacerated wounds in children. All the patients were given P.O. amplicillin for five days. Healing rate of 100% was achieved with framycetin, gention violet paint, mercurochrome paint and povidone iodine with 4-6 days of treatment; whereas only 56.25%, 66.66% and 54.55% wound healing were observed with nitrofurazone, polymixin + neomycin + bacitracin and silver sulphadiazine respectively. The nonheating wounds in the latter group when subjected to an application of the agents that showed 100% healing, heated in another 5-6 days.

  3. Lycopersicon esculentum seeds: an industrial byproduct as an antimicrobial agent.

    Science.gov (United States)

    Taveira, Marcos; Silva, Luís R; Vale-Silva, Luís A; Pinto, Eugénia; Valentão, Patrícia; Ferreres, Federico; Guedes de Pinho, Paula; Andrade, Paula B

    2010-09-08

    Lycopersicon esculentum (tomato) fruit is a widely studied matrix. However, only few works focus their attention on its seeds, which constitute a major byproduct of the tomato processing industry. In this study the antimicrobial potential of ten different tomato seed extracts from "Bull's heart" and "Cherry" varieties were analyzed against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Enterococcus faecalis and Bacillus cereus) and Gram-negative (Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium) bacteria and fungi (Candida albicans, Aspergillus fumigatus and Trichophyton rubrum). Regarding antibacterial capacity, the different extracts were revealed to be active only against Gram-positive bacteria, E. faecalis being the most susceptible one (MIC: 2.5-10 mg/mL). Concerning antifungal activity, "Bull's heart" extracts were the most active. In a general way C. albicans was the most susceptible species (MIC: 5-10 mg/mL). The chemical composition of the extracts was also pursued, concerning organic acids, phenolics and fatty acids, in order to establish a possible relationship with the observed antimicrobial effect.

  4. Ethyl Pyruvate: An Anti-Microbial Agent that Selectively Targets Pathobionts and Biofilms

    OpenAIRE

    Debebe, Tewodros; Kr?ger, Monika; Huse, Klaus; Kacza, Johannes; M?hlberg, Katja; K?nig, Brigitte; Birkenmeier, Gerd

    2016-01-01

    The microbiota has a strong influence on health and disease in humans. A causative shift favoring pathobionts is strongly linked to diseases. Therefore, anti-microbial agents selectively targeting potential pathogens as well as their biofilms are urgently demanded. Here we demonstrate the impact of ethyl pyruvate, so far known as ROS scavenger and anti-inflammatory agent, on planktonic microbes and biofilms. Ethyl pyruvate combats preferably the growth of pathobionts belonging to bacteria and...

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Chemokine-Derived Peptides: Novel Antimicrobial and Antineoplasic Agents

    Directory of Open Access Journals (Sweden)

    Julio Valdivia-Silva

    2015-06-01

    Full Text Available Chemokines are a burgeoning family of chemotactic cytokines displaying a broad array of functions such as regulation of homeostatic leukocyte traffic and development, as well as activating the innate immune system. Their role in controlling early and late inflammatory stages is now well recognized. An improper balance either in chemokine synthesis or chemokine receptor expression contributes to various pathological disorders making chemokines and their receptors a useful therapeutic target. Research in this area is progressing rapidly, and development of novel agents based on chemokine/ chemokine receptors antagonist functions are emerging as attractive alternative drugs. Some of these novel agents include generation of chemokine-derived peptides (CDP with potential agonist and antagonist effects on inflammation, cancer and against bacterial infections. CDP have been generated mainly from N- and C-terminus chemokine sequences with subsequent modifications such as truncations or elongations. In this review, we present a glimpse of the different pharmacological actions reported for CDP and our current understanding regarding the potential use of CDP alone or as part of the novel therapies proposed in the treatment of microbial infections and cancer.

  15. Hydrazide-hydrazones as potential antimicrobial agents: overview of the literature since 2010.

    Science.gov (United States)

    Popiołek, Łukasz

    2017-01-01

    Hydrazide-hydrazone derivatives are present in many bioactive molecules and display a wide variety of biological activities, such as antibacterial, antitubercular, antifungal, anticancer, anti-inflammatory, anticonvulsant, antiviral, and antiprotozoal action. Therefore, many medicinal chemists synthesize various hydrazide-hydrazones and evaluate them for biological activities. Among biological properties of this class of compounds, antimicrobial activity is the most frequently encountered in scientific literature. This paper is focused on the overview of the literature findings of the last six years (2010-2016) covering the research on antimicrobial activity of hydrazide-hydrazone derivatives. This review may also serve as a useful guide for the development of new hydrazide-hydrazones as potential antimicrobial agents.

  16. 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.

  17. Potential of medicinal plants as antimicrobial and antioxidant agents in food industry: a hypothesis.

    Science.gov (United States)

    Ortega-Ramirez, Luis Alberto; Rodriguez-Garcia, Isela; Leyva, Juan Manuel; Cruz-Valenzuela, Manuel Reynaldo; Silva-Espinoza, Brenda Adriana; Gonzalez-Aguilar, Gustavo A; Siddiqui, Wasim; Ayala-Zavala, Jesus Fernando

    2014-02-01

    Many food preservation strategies can be used for the control of microbial spoilage and oxidation; however, these quality problems are not yet controlled adequately. Although synthetic antimicrobial and antioxidant agents are approved in many countries, the use of natural safe and effective preservatives is a demand of food consumers and producers. This paper proposes medicinal plants, traditionally used to treat health disorders and prevent diseases, as a source of bioactive compounds having food additive properties. Medicinal plants are rich in terpenes and phenolic compounds that present antimicrobial and antioxidant properties; in addition, the literature revealed that these bioactive compounds extracted from other plants have been effective in food systems. In this context, the present hypothesis paper states that bioactive molecules extracted from medicinal plants can be used as antimicrobial and antioxidant additives in the food industry. © 2014 Institute of Food Technologists®

  18. 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.

  19. Systematic study of non-natural short cationic lipopeptides as novel broad-spectrum antimicrobial agents.

    Science.gov (United States)

    Lohan, Sandeep; Cameotra, Swaranjit S; Bisht, Gopal S

    2013-11-01

    We describe the design and synthesis of a new series of non-natural short cationic lipopeptides (MW = 700) as antimicrobial agents. All of the synthesized lipopeptides were tested against a range of microbes such as Gram-positive, Gram-negative bacteria, fungi including methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE). By systematic study of design template, we found that three ornithine residues conjugated with myristic acid are minimum requirement for a compound to be an antimicrobial agent. The most potent lipopeptide LP16 possesses broad-spectrum antimicrobial activity and has MICs in the range of 1.5-6.25 μg/mL against Escherichia coli, S. aureus, Pseudomonas aeruginosa, Bacillus subtilis, and MRSE. All lipopeptides showed high selectivity toward microbial strains as compared to human red blood cells (HC50 > 250 μg/mL). Moreover, most potent lipopeptides (LP16 and LP23) did not induce drug resistance in S. aureus even after 15 rounds of passaging. In addition, a representative lipopeptide (LP16) showed tryptic stability for 24 h. These results suggest the potential of short cationic lipopeptides to boost the discovery of future antimicrobial therapeutics. © 2013 John Wiley & Sons A/S.

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

    Science.gov (United States)

    Czyzewski, Ann M; Jenssen, Håvard; Fjell, Christopher D; Waldbrook, Matt; Chongsiriwatana, Nathaniel P; Yuen, Eddie; Hancock, Robert E W; Barron, Annelise E

    2016-01-01

    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 mimetics renders them robust to proteolytic degradation, thus offering a distinct advantage for their clinical application. We explore the therapeutic potential of N-substituted glycines, or peptoids, as AMP mimics using a multi-faceted approach that includes in silico, in vitro, and in vivo techniques. We 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 strains. Lastly, using a murine model of invasive S. aureus infection, we demonstrate that one of the best candidate peptoids at 4 mg/kg significantly reduces with a two-log order the bacterial counts compared with saline-treated controls. Taken together, our results demonstrate the promising therapeutic potential of peptoids as antimicrobial agents.

  1. Component Release and Mechanical Properties of Endodontic Sealers following Incorporation of Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Elizabeta S. Gjorgievska

    2017-01-01

    Full Text Available Root canal sealers with antimicrobial activity are highly beneficial; therefore, their antimicrobial properties could be improved by incorporation of antimicrobial agents. In the present study, the release of the quaternary ammonium compounds from endodontic sealers admixed with either benzalkonium chloride (BC or cetylpyridinium chloride (CPC at loadings of 2% wt was monitored. The effect of these additives on the compressive strengths and their release from the sealers was determined after 1 and 4 weeks. All of the materials studied were found to be capable of releasing antimicrobial additive in useful quantities. The release of CPC occurred to a statistically significant greater extent than BC for all materials. The addition of both BC and CPC generally decreased the compressive strength of all the endodontic sealers, with the exception of CPC in AH Plus, where the compressive strength was significantly increased. This suggests that, for these endodontic sealers, the antimicrobial additives alter the setting chemistry. AH Plus is an epoxy-based material cured with an amine, and in this case the increase in compressive strength with CPC is attributed to an enhanced cure reaction with this system. In all other cases, the additive inhibited the cure reaction to a greater or lesser extent.

  2. 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.

  3. ADVERSE REACTIONS TO ANTIMICROBIAL AGENTS IN INTERNAL MEDICINE AND ORTHOPEDIC SERVICES. JOSINA MACHEL HOSPITAL, 2014

    OpenAIRE

    Mateus Sebastião João Fernandes; Héctor Lara Fernández; Vladimir Calzadilla Moreira

    2015-01-01

    A descriptive, prospective study was conducted to characterize the incidence and type of Adverse Drug Reactions (ADR) to antimicrobial agents in patients hospitalized in internal medicine and Orthopedic services at “Josina Machel” Central Hospital, in Luanda, in the period from January to February 2014 . The occurrence of adverse drug reactions was assessed by daily review of the clinical history of the patients with active search for potentially adverse effects associated with prescription a...

  4. 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.

  5. All Natural and Clean-Label Preservatives and Antimicrobial Agents Used during Poultry Processing and Packaging.

    Science.gov (United States)

    Grant, Ar'quette; Parveen, Salina

    2017-04-01

    The poultry industry is faced with compounding pressures of maintaining product safety and wholesomeness while keeping up with consumer trends of all-natural foods and label accuracy. Consumers are increasingly demanding that their foods be minimally processed and contain compounds that are easily read and recognized, i.e., products must be clean labeled. The purpose of this review is to briefly describe several natural antimicrobial agents that can be incorporated into poultry processing. These compounds and their essential oils were included in this mini-review because they are generally recognized as safe by the U.S. Food and Drug Administration and are considered clean label: thyme extract, rosemary extract, garlic, and oregano. This list of natural antimicrobial agents by no means includes all of the options available to poultry processors. Rather, this review provides a brief glance at the potential these natural antimicrobial agents have in terms of reduced pathogenicity, increased shelf stability, and sensory acceptability through direct product application or as part of the product packaging.

  6. Identification of Cyclic Dipeptides from Escherichia coli as New Antimicrobial Agents against Ralstonia Solanacearum

    Directory of Open Access Journals (Sweden)

    Shihao Song

    2018-01-01

    Full Text Available Ralstonia solanacearum is a causative agent of bacterial wilt in many important crops throughout the world. How to control bacterial wilt caused by R. solanacearum is a major problem in agriculture. In this study, we aim to isolate the biocontrol agents that have high efficacy in the control of bacterial wilt. Three new bacterial strains with high antimicrobial activity against R. solanacearum GMI1000 were isolated and identified. Our results demonstrated that these bacteria could remarkably inhibit the disease index of host plant infected by R. solanacearum. It was indicated that strain GZ-34 (CCTCC No. M 2016353 showed an excellent protective effect to tomato under greenhouse conditions. Strain GZ-34 was characterized as Escherichia coli based on morphology, biochemistry, and 16S rRNA analysis. We identified that the main antimicrobial compounds produced by E. coli GZ-34 were cyclo(l-Pro-d-Ile and cyclo(l-Pro-l-Phe using electrospray ionization mass spectrometry (ESI-MS and nuclear magnetic resonance (NMR analysis. The two active compounds also interfered with the expression levels of some pathogenicity-contributors of R. solanacearum. Furthermore, cyclo(l-Pro-l-Phe effectively inhibited spore formation of Magnaporthe grisea, which is a vital pathogenesis process of the fungal pathogen, suggesting cyclic dipeptides from E. coli are promising potential antimicrobial agents with broad-spectrum activity to kill pathogens or interfere with their pathogenesis.

  7. Functional gold nanoclusters as antimicrobial agents for antibiotic-resistant bacteria.

    Science.gov (United States)

    Chen, Wei-Yu; Lin, Ju-Yu; Chen, Wei-Jen; Luo, Liyang; Wei-Guang Diau, Eric; Chen, Yu-Chie

    2010-07-01

    Our aim was to demonstrate that lysozyme-directed generation of gold nanoclusters (Au NCs) are potential antimicrobial agents for antibiotic-resistant bacteria and broad labeling agents for pathogenic bacteria. Lysozyme is an enzyme that is capable of hydrolyzing the cell walls of bacteria. In this study, we demonstrated the generation of functional Au NCs by using lysozyme as the sequester and the reducing agent for Au precursors at 40 degrees C. In addition, to shorten the reaction time, the reaction was conducted under microwave irradiation within a short period of time for the first time. The bioactivity of the lysozyme on the Au NCs was retained. Therefore, the as-prepared lysozyme-Au NCs with desirable fluorescence feature were successfully employed to be broad-band labeling agents for pathogenic bacteria. Furthermore, we also demonstrated that the lysozyme-Au NCs can be used to effectively inhibit the cell growth of notorious antibiotic-resistant bacteria, including pan-drug-resistant Acinetobacter baumannii and vancomycin-resistant Enterococcus faecalis. The potential of employing the lysozyme-Au NCs for bacterial labeling and as antimicrobial agents is expected.

  8. 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

  9. Resistance ofStaphylococcus aureusto 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

  10. 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.

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

    OpenAIRE

    Xing, Yage; Xu, Qinglian; Li, Xingchen; Chen, Cunkun; Ma, Li; Li, Shaohua; Che, Zhenming; Lin, Hongbin

    2016-01-01

    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 art...

  12. Effect of electrical current on the activities of antimicrobial agents against Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis biofilms.

    Science.gov (United States)

    del Pozo, Jose L; Rouse, Mark S; Mandrekar, Jayawant N; Sampedro, Marta Fernandez; Steckelberg, James M; Patel, Robin

    2009-01-01

    Bacterial biofilms are resistant to conventional antimicrobial agents. Prior in vitro studies have shown that electrical current (EC) enhances the activities of aminoglycosides, quinolones, and oxytetracycline against Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus epidermidis, Escherichia coli, and Streptococcus gordonii. This phenomenon, known as the bioelectric effect, has been only partially defined. The purpose of this work was to study the in vitro bioelectric effect on the activities of 11 antimicrobial agents representing a variety of different classes against P. aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and S. epidermidis. An eight-channel current generator/controller and eight chambers delivering a continuous flow of fresh medium with or without antimicrobial agents and/or EC to biofilm-coated coupons were used. No significant decreases in the numbers of log(10) CFU/cm(2) were seen after exposure to antimicrobial agents alone, with the exception of a 4.57-log-unit reduction for S. epidermidis and trimethoprim-sulfamethoxazole. We detected a statistically significant bioelectric effect when vancomycin plus 2,000 microamperes EC were used against MRSA biofilms (P = 0.04) and when daptomycin and erythromycin were used in combination with 200 or 2,000 microamperes EC against S. epidermidis biofilms (P = 0.02 and 0.0004, respectively). The results of these experiments indicate that the enhancement of the activity of antimicrobial agents against biofilm organisms by EC is not a generalizable phenomenon across microorganisms and antimicrobial agents.

  13. 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.

  14. 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.

  15. 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.

  16. Antimicrobial activities of Rhizobium sp. strains against Pseudomonas savastanoi, the agent responsible for the olive knot disease in Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Mourad, K.; Fadhila, K.; Chahinez, M.; Merien, R.; Philippe, L. de; Abdelkader, B.

    2009-07-01

    In the present investigation, six Rhizobium strains isolated from Algerian soil were checked for their antimicrobial activity against Pseudomonas savastanoi, the agent responsible for olive knot disease. Rhizobium sp. ORN 24 and ORN 83 were found to produce antimicrobial activities against Pseudomonas savastanoi. The antimicrobial activity produced by Rhizobium sp. ORN24 was precipitable with ammonium sulfate, between 1,000 and 10,000 KDa molecular weight, heat resistant but sensitive to proteases and detergents. These characteristics suggest the bacteriocin nature of the antimicrobial substance produced by Rhizobium sp. ORN24, named rhizobiocin 24. In contrast, the antimicrobial activity produced by Rhizobium sp. ORN83 was not precipitable with ammonium sulfate; it was smaller than 1,000 KDa molecular weight, heat labile, and protease and detergent resistant. These characteristics could indicate the relationship between the antimicrobial substance produced by Rhizobium sp. ORN 83 and the small bacteriocins described in other rhizobia. (Author) 51 refs.

  17. Efficacy of Yeast' Vacuoles as Antimicrobial Agents to Escherichia coli Bacteremia in Rat.

    Science.gov (United States)

    Yoon, Jihee; Cho, Ho-Seong; Park, Chul; Park, Byoung-Yong; Kim, Yang-Hoon; Min, Jiho

    2017-01-01

    Yeast vacuoles, lysosomes, are cell organelles that have antimicrobial activity against several bacteria in vitro. Lysosomes have a potential application to the treatment of pathogens such as antibiotics in vivo. Therefore, the in vivo efficacy of lysosomes was examined in a rat infection model against pathogenic Escherichia coli with varying susceptibilities to standard antimicrobial agents. Before in vivo testing, the concentration-dependent safety of lysosomes was confirmed by blood test and histopathology of normal rats. The therapeutic efficacy of lysosomes was examined in terms of the survival of E. coli in infected rat blood. The complete blood count and histopathology results were affected by the lysosomes concentration. In addition, the E. coli growth was inhibited by the initial injection of lysosomes. These results support the use of lysosomes as a bacterial inhibitor of an infected rat model.

  18. 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.)

  19. 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.)

  20. Antimicrobial peptides incorporating non-natural amino acids as agents for plant protection.

    Science.gov (United States)

    Ng-Choi, Iteng; Soler, Marta; Güell, Imma; Badosa, Esther; Cabrefiga, Jordi; Bardaji, Eduard; Montesinos, Emilio; Planas, Marta; Feliu, Lidia

    2014-04-01

    The control of plant pathogens is mainly based on copper compounds and antibiotics. However, the use of these compounds has some limitations. They have a high environmental impact and the use of antibiotics is not allowed in several countries. Moreover, resistance has been developed to these pathogens. The identification of new agents able to fight plant pathogenic bacteria and fungi will represent an alternative to currently used antibiotics or pesticides. Antimicrobial peptides are widely recognized as promising candidates, however naturally occurring sequences present drawbacks that limit their development. These include susceptibility to protease degradation and low bioavailability. To overcome these problems, research has focused on the introduction of unnatural amino acids into lead peptide sequences. In particular, we have improved the biological profile of antimicrobial peptides active against plant pathogenic bacteria and fungi by incorporating triazolyl, biaryl and D-amino acids into their sequence. These modifications and their influence on the biological activity are summarized.

  1. Design, synthesis, and evaluation of fimbrolide-nitric oxide donor hybrids as antimicrobial agents.

    Science.gov (United States)

    Kutty, Samuel K; Barraud, Nicolas; Pham, Amy; Iskander, George; Rice, Scott A; Black, David StC; Kumar, Naresh

    2013-12-12

    Fimbrolides from marine algae have shown promising activity against quorum sensing (QS), a chief regulatory and communication system in bacteria controlling biofilm formation and virulence factor. Nitric oxide (NO) at sublethal concentration has also been reported to induce dispersal of bacterial biofilms and increase their susceptibility toward standard biocides and antibiotics. Therefore, the combination of QS inhibitors and NO donors has the potential to control the development of biofilm and promote their dispersion via a nonbactericidal mechanism. Inspired by these ideas, novel fimbrolide-NO donor hybrid compounds were designed and synthesized. Fimbrolide-NO hybrids 6b, 6f, and 14a were found to be particularly effective as antimicrobials compared to the nonhybrid natural fimbrolides as revealed by bioluminescent P. aeruginosa QS reporter assays and biofilm inhibition assays. Significantly, these fimbrolide-NO hybrids represent the first dual-action antimicrobial agent based on the baterial QS inhibition and NO signaling.

  2. Antimicrobial agents used in the control of periodontal biofilms: effective adjuncts to mechanical plaque control?

    Directory of Open Access Journals (Sweden)

    Ricardo Palmier Teles

    2009-06-01

    Full Text Available The control of biofilm accumulation on teeth has been the cornerstone of periodontal disease prevention for decades. However, the widespread prevalence of gingivitis suggests the inefficiency of self-performed mechanical plaque control in preventing gingival inflammation. This is particularly relevant in light of recent evidence suggesting that long standing gingivitis increases the risk of loss of attachment and that prevention of gingival inflammation might reduce the prevalence of mild to moderate periodontitis. Several antimicrobials have been tested as adjuncts to mechanical plaque control in order to improve the results obtained with oral home care. Recent studies, including meta-analyses, have indicated that home care products containing chemical antimicrobials can provide gingivitis reduction beyond what can be accomplished with brushing and flossing. Particularly, formulations containing chlorhexidine, mouthrinses containing essential oils and triclosan/copolymer dentifrices have well documented clinical antiplaque and antigingivitis effects. In vivo microbiological tests have demonstrated the ability of these antimicrobial agents to penetrate the biofilm mass and to kill bacteria growing within biofilms. In addition, chemical antimicrobials can reach difficult-to-clean areas such as interproximal surfaces and can also impact the growth of biofilms on soft tissue. These agents have a positive track record of safety and their use does not seem to increase the levels of resistant species. Further, no study has been able to establish a correlation between mouthrinses containing alcohol and oral cancer. In summary, the adjunct use of chemical plaque control should be recommended to subjects with well documented difficulties in achieving proper biofilm control using only mechanical means.

  3. Antimicrobial agents used in the control of periodontal biofilms: effective adjuncts to mechanical plaque control?

    Science.gov (United States)

    Teles, Ricardo Palmier; Teles, Flavia Rocha Fonseca

    2009-01-01

    The control of biofilm accumulation on teeth has been the cornerstone of periodontal disease prevention for decades. However, the widespread prevalence of gingivitis suggests the inefficiency of self-performed mechanical plaque control in preventing gingival inflammation. This is particularly relevant in light of recent evidence suggesting that long standing gingivitis increases the risk of loss of attachment and that prevention of gingival inflammation might reduce the prevalence of mild to moderate periodontitis. Several antimicrobials have been tested as adjuncts to mechanical plaque control in order to improve the results obtained with oral home care. Recent studies, including meta-analyses, have indicated that home care products containing chemical antimicrobials can provide gingivitis reduction beyond what can be accomplished with brushing and flossing. Particularly, formulations containing chlorhexidine, mouthrinses containing essential oils and triclosan/copolymer dentifrices have well documented clinical antiplaque and antigingivitis effects. In vivo microbiological tests have demonstrated the ability of these antimicrobial agents to penetrate the biofilm mass and to kill bacteria growing within biofilms. In addition, chemical antimicrobials can reach difficult-to-clean areas such as interproximal surfaces and can also impact the growth of biofilms on soft tissue. These agents have a positive track record of safety and their use does not seem to increase the levels of resistant species. Further, no study has been able to establish a correlation between mouthrinses containing alcohol and oral cancer. In summary, the adjunct use of chemical plaque control should be recommended to subjects with well documented difficulties in achieving proper biofilm control using only mechanical means.

  4. Matrix Metalloproteinase Inhibitor as an Antimicrobial Agent to Eradicate Enterococcus faecalis Biofilm.

    Science.gov (United States)

    Tay, Chiew Xsia; Quah, Samantha Yiling; Lui, Jeen Nee; Yu, Victoria Soo Hoon; Tan, Kai Soo

    2015-06-01

    Successful endodontic treatment outcomes require new strategies for the complete eradication of microbial biofilms in the root canal system. Matrix metalloproteinases (MMPs) are essential enzymes in microbial cell growth and homeostasis, and they require transition metal ion cofactors to function. Targeting MMP activity also preserves dentin collagen integrity. In this study, 1,10-phenanthroline-5,6-dione (Phendione), a metal chelator, was tested as a potentially novel antimicrobial agent against Enterococcus faecalis and inhibitor of human MMP in the root canal. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Phendione on E. faecalis were determined. The antimicrobial properties of Phendione in the presence of dentin powder and various transition metal ions were examined. The ability of Phendione to inhibit human MMP-2 was subsequently tested. The efficacy of Phendione against E. faecalis biofilm was determined by exposure of 7-day-old E. faecalis biofilms to Phendione. The MIC and MBC of Phendione were 2.0 μg/mL and 16 μg/mL, respectively, whereas 64 μg/mL was required to kill E. faecalis biofilm. Phendione completely eradicated E. faecalis despite dentin preincubation. The presence of Zn(2+), and to a lesser extent Fe(2+), abrogated the antimicrobial effect of Phendione. In addition, Phendione at MIC and MBC significantly inhibited human MMP-2 activity. Phendione effectively eradicated E. faecalis biofilms and significantly inhibited human MMP-2 through its ability to chelate metal ions. The antibacterial property of Phendione was preserved in the presence of dentin. Phendione can potentially be applied in endodontic treatment as both an antimicrobial agent and MMP inhibitor. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  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. Staphylococcus aureus: nuevos y antiguos antimicrobianos Staphylococcus aureus: new and old antimicrobial agents

    Directory of Open Access Journals (Sweden)

    B. Perazzi

    2010-09-01

    Full Text Available El objetivo del trabajo fue evaluar la sensibilidad a antiguos y nuevos antimicrobianos de aislamientos de Staphylococcus aureus resistentes a la oxacilina, de origen hospitalario (SAOR-H y adquiridos en la comunidad (SAOR-AC, y también en aislamientos sensibles a la oxacilina (SAOS. Se estudió en forma prospectiva la concentración inhibitoria mínima a diversos antimicrobianos en 118 aislamientos consecutivos por dilución seriada en agar según las indicaciones del CLSI. En los aislamientos de SAOR sin resistencia acompañante se determinó la presencia de los genes mec A, leucocidina de Panton Valentine (LPV y γ-hemolisina por PCR, y del cassette SCC mec por PCR múltiple. De los 118 aislamientos estudiados, 44 fueron SAOR-H, 16 SAOR-AC y 58 SAOS. Los aislamientos de SAOR-H presentaron resistencia simultánea a eritromicina, clindamicina, gentamicina, ciprofloxacina, levofloxacina y moxifloxacina, y todos fueron sensibles a tigeciclina (TIG, vancomicina, teicoplanina y linezolid (LZD. Los aislamientos de SAOR-AC fueron resistentes solamente a OXA y sensibles a todos los antimicrobianos ensayados. En todos ellos se detectaron los genes mec A, LPV, γ-hemolisina y el cassette SCC mec IV. En SAOS y en SAOR-AC todos los antimicrobianos no ß-lactámicos ensayados presentaron excelente actividad in vitro, mientras que en SAOR-H sólo los antiguos antimicrobianos como glucopéptidos, doxiciclina, rifampicina y trimetoprima-sulfametoxazol presentaron buena actividad in vitro, al igual que LZD y TIG entre los nuevos antimicrobianos. El fenotipo de SAOR sin resistencia acompañante fue altamente predictivo de SAOR-AC, ya que fue confirmado por presentar el cassette SCC mec IV.The objective of the study was to evaluate the susceptibility to old and new antimicrobial agents against hospital-acquired oxacillin-resistant Staphylococcus aureus (HA-ORSA, community-acquired oxacillin-resistant S. aureus (CA-ORSA, and oxacillin-susceptible S. aureus (OSSA

  7. In vitro susceptibility of European human Borrelia burgdorferi sensu stricto strains to antimicrobial agents.

    Science.gov (United States)

    Veinović, Gorana; Cerar, Tjaša; Strle, Franc; Lotrič-Furlan, Stanka; Maraspin, Vera; Cimperman, Jože; Ružić-Sabljić, Eva

    2013-03-01

    Broth microdilution and macrodilution assays were used to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of six antimicrobial agents (ceftriaxone, cefuroxime sodium, azithromycin, amoxicillin, doxycycline and amikacin) for nine European human isolates of Borrelia burgdorferi sensu stricto (s.s.). Strains were obtained from patients diagnosed with Lyme borreliosis in Slovenia. Modified Kelly-Pettenkofer medium with a final inoculum of 10⁵ Borrelia cells/mL and incubation periods of 72 h and of 3 weeks and 6 weeks were used in the determination of MICs and MBCs, respectively. Observed MICs indicated that all isolates were susceptible to all the tested antimicrobial agents with the exception of amikacin. Cefuroxime sodium (MIC₉₀=0.063 mg/L), azithromycin (MIC₉₀=0.22 mg/L) and ceftriaxone (MIC₉₀=0.25 mg/L) displayed the lowest MICs, followed by amoxicillin (MIC₉₀=1 mg/L) and doxycycline (MIC₉₀=2 mg/L); no strain was susceptible to amikacin (MIC₉₀=256 mg/L). MBCs after incubation for 3 weeks and 6 weeks were determined for amoxicillin (MBC₉₀=32 mg/L), doxycycline (MBC₉₀)=32 mg/L) and amikacin (MBC₉₀=1024 mg/L) and were found to be high (but not defined) for azithromycin (MBC₉₀>0.88 mg/L), cefuroxime sodium (MBC₉₀>4 mg/L) and ceftriaxone (MBC₉₀>4 mg/L). In determination of borrelial susceptibility to antimicrobial agents, intrinsic low susceptibility or methodological factors could result in low in vitro susceptibility of individual strains. This study is the first report on the antibiotic susceptibility of a series of European human isolates of B. burgdorferi s.s. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  8. ADVERSE REACTIONS TO ANTIMICROBIAL AGENTS IN INTERNAL MEDICINE AND ORTHOPEDIC SERVICES. JOSINA MACHEL HOSPITAL, 2014

    Directory of Open Access Journals (Sweden)

    Mateus Sebastião João Fernandes

    2015-10-01

    Full Text Available A descriptive, prospective study was conducted to characterize the incidence and type of Adverse Drug Reactions (ADR to antimicrobial agents in patients hospitalized in internal medicine and Orthopedic services at “Josina Machel” Central Hospital, in Luanda, in the period from January to February 2014 . The occurrence of adverse drug reactions was assessed by daily review of the clinical history of the patients with active search for potentially adverse effects associated with prescription antimicrobial agents. Of a total of 206 hospitalized patients, 21 were affected by ADR, corresponding to an incidence rate of 10.2%. The incidence was significantly higher in the internal medicine service, occurring in 11.7% of 137 patients admitted, while in the orthopedic service the incidence was 7.2% (5/69. The highest incidence of ADR was recorded in patients aged 30-39 years in 10 patients (4.9%, and in the female gender (7.8%. The most common clinical manifestations of ADR were rash (17.2%, followed by headache, pruritus and nausea and vomiting (13.8%. The antimicrobials most frequently associated with the occurrence of ADR were the antimalarial, related to more than half the cases. Among the antibacterial agents cephalosporins were associated to five cases of ADR (23.8%. Most ADR were classified according to severity as mild (52.4% and as probable (57.1% regarding the attribution of causality. Given the growing impact of the occurrence of ADR we recommend pursuing this research, in order to further deepen this problem.

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

    Directory of Open Access Journals (Sweden)

    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.

  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. Effect of antimicrobial agents on the Euglena method of serum vitamin B12 assay

    Science.gov (United States)

    Lie, J. T.; Ungar, Berta; Cowling, D. C.

    1969-01-01

    Antimicrobial agents in the serum may affect the results of the Euglena method of serum vitamin B12 assay. Sulphonamides suppress the growth of Euglena in concentrations attainable in the serum during treatment; streptomycin, chlortetracycline, erythromycin, kanamycin, and nitrofurantoin bleach Euglena but only when present in concentrations far exceeding the normal peak therapeutic blood levels. False low results of serum vitamin B12 assay due to inhibitory and/or bleaching substances in the serum can be readily detected by microscopy of the assay cultures and Euglena cell counts. PMID:5364439

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

    Directory of Open Access Journals (Sweden)

    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.

  13. In Vitro Synergistic Effect of Psidium guineense (Swartz in Combination with Antimicrobial Agents against Methicillin-Resistant Staphylococcus aureus Strains

    Directory of Open Access Journals (Sweden)

    Tiago Gomes Fernandes

    2012-01-01

    Full Text Available The aim of this study was to evaluate the antimicrobial activity of aqueous extract of Psidium guineense Swartz (Araçá-do-campo and five antimicrobials (ampicillin, amoxicillin/clavulanic acid, cefoxitin, ciprofloxacin, and meropenem against twelve strains of Staphylococcus aureus with a resistant phenotype previously determined by the disk diffusion method. Four S. aureus strains showed resistance to all antimicrobial agents tested and were selected for the study of the interaction between aqueous extract of P. guineense and antimicrobial agents, by the checkerboard method. The criteria used to evaluate the synergistic activity were defined by the fractional inhibitory concentration index (FICI. All S. aureus strains were susceptible to P. guineense as determined by the microdilution method. The combination of the P. guineense extract with the antimicrobial agents resulted in an eight-fold reduction in the MIC of these agents, which showed a FICI ranging from 0.125 to 0.5, suggesting a synergistic interaction against methicillin-resistant Staphylococcus aureus (MRSA strains. The combination of the aqueous extract of P. guineense with cefoxitin showed the lowest FICI values. This study demonstrated that the aqueous extract of P. guineense combined with beta lactamics antimicrobials, fluoroquinolones, and carbapenems, acts synergistically by inhibiting MRSA strains.

  14. Etiological agents and antimicrobial susceptibility in hospitalized children with acute pyelonephritis.

    Science.gov (United States)

    Flor-de-Lima, Filipa; Martins, Tânia; Teixeira, Ana; Pinto, Helena; Botelho-Moniz, Edgar; Caldas-Afonso, Alberto

    2015-01-01

    Antibiotic resistance driven by antibiotic use remains a major public health and professional concern. Our aim was to know the local prevalence of uropathogens and their antimicrobial susceptibility profile in acute pyelonephritis. A prospective study of patients admitted in a level III Pediatric Department ward with acute pyelonephritis from 1994 to 2012 was performed in Northern Portugal. Etiological agents and their antimicrobial sensitivity profile were evaluated in four timed periods (G1: 1994-97; G2: 2002; G3: 2007; G4: 2012). We evaluated 581 patients, 66% female with median age 22 months. Escherichia coli was the leading uropathogen and its prevalence remained stable during the last 18 years. It showed an increased sensitivity to amoxicillin-clavulanate from 71% in G1 to 81.5% in G4 (p = 0.001) and a decreased resistance rate from 8.7% in G1 to 2.8% in G4 (p = 0.008). Its sensitivity to 2nd and 3rd generation cephalosporin was more than 90% (p = ns) and more than 95% to nitrofurantoin (p = ns). Resistance rate of cotrimoxazole increased from 22% to 26% (p = 0.008). Escherichia coli remains the main uropathogen responsible for acute pyelonephritis, reason why its antimicrobial sensitivity profile will determine the empirical therapeutic choice. Amoxicillin-clavulanate remains a good first-line choice for empirical treatment of acute pyelonephritis in our inpatient health care.

  15. Synergistic antibiotic effect of looped antimicrobial peptide CLP-19 with bactericidal and bacteriostatic agents.

    Science.gov (United States)

    Li, Di; Yang, Ya; Tian, Zhiqiang; Lv, Jun; Sun, Fengjun; Wang, Qian; Liu, Yao; Xia, Peiyuan

    2017-08-22

    The treatment of drug-resistant infections is complicated and the alarming rise in infectious diseases poses a unique challenge for development of effective therapeutic strategies. Antibiotic-induced liberation of the bacterial endotoxin lipopolysaccharide (LPS) may have immediate adverse effects promoting septic shock in patients. In the present study, we first confirmed our previous finding that looped antimicrobial peptide CLP-19 exerts non-specific direct antibacterial activity with no toxic to mammalian cells and second revealed that CLP-19 has synergistic effect to enhance the antibacterial activities of other conventional bactericidal (ampicillin and ceftazidime) and bacteriostatic (erythromycin and levofloxacin) agents. Third, the underlying mechanism of antibiotic effect was likely associated with stimulation of hydroxyl radical generation. Lastly, CLP-19 was shown to effectively reduce the antibiotic-induced liberation of LPS, through direct neutralization of the LPS. Thus, CLP-19 is a potential therapeutic agent for combinatorial antibiotic therapy.

  16. β-Lactone natural products and derivatives inactivate homoserine transacetylase, a target for antimicrobial agents.

    Science.gov (United States)

    De Pascale, Gianfranco; Nazi, Ishac; Harrison, Paul H M; Wright, Gerard D

    2011-07-01

    Homoserine transacetylase (HTA) catalyzes the transfer of an acetyl group from acetyl-CoA to the hydroxyl group of homoserine. This is the first committed step in the biosynthesis of methionine (Met) from aspartic acid in many fungi, Gram-positive and some Gram-negative bacteria. The enzyme is absent in higher eukaryotes and is important for microorganism growth in Met-poor environments, such as blood serum, making HTA an attractive target for new antimicrobial agents. HTA catalyzes acetyl transfer via a double displacement mechanism facilitated by a classic Ser-His-Asp catalytic triad located at the bottom of a narrow actives site tunnel. We explored the inhibitory activity of several β-lactones to block the activity of HTA. In particular, the natural product ebelactone A, a β-lactone with a hydrophobic tail was found to be a potent inactivator of HTA from Haemophilus influenzae. Synthetic analogs of ebelactone A demonstrated improved inactivation characteristics. Covalent modification of HTA was confirmed by mass spectrometry, and peptide mapping identified Ser143 as the modified residue, consistent with the known structure and mechanism of the enzyme. These results demonstrate that β-lactone inhibitors are excellent biochemical probes of HTA and potential leads for new antimicrobial agents.

  17. Inactivation of staphylococcal virulence factors using a light-activated antimicrobial agent

    Directory of Open Access Journals (Sweden)

    Wilson Michael

    2009-10-01

    Full Text Available Abstract Background One of the limitations of antibiotic therapy is that even after successful killing of the infecting microorganism, virulence factors may still be present and cause significant damage to the host. Light-activated antimicrobials show potential for the treatment of topical infections; therefore if these agents can also inactivate microbial virulence factors, this would represent an advantage over conventional antibiotic therapy. Staphylococcus aureus produces a wide range of virulence factors that contribute to its success as a pathogen by facilitating colonisation and destruction of host tissues. Results In this study, the ability of the light-activated antimicrobial agent methylene blue in combination with laser light of 665 nm to inactivate staphylococcal virulence factors was assessed. A number of proteinaceous virulence factors were exposed to laser light in the presence of methylene blue and their biological activities re-determined. The activities of V8 protease, α-haemolysin and sphingomyelinase were shown to be inhibited in a dose-dependent manner by exposure to laser light in the presence of methylene blue. Conclusion These results suggest that photodynamic therapy could reduce the harmful impact of preformed virulence factors on the host.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. 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.

  1. 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...

  2. In vitro assessment of chloramphenicol and florfenicol as second-line antimicrobial agents in dogs.

    Science.gov (United States)

    Maaland, M G; Mo, S S; Schwarz, S; Guardabassi, L

    2015-10-01

    The aim of this study was to evaluate the potential of chloramphenicol and florfenicol as second-line antimicrobial agents for treatment of infections caused by methicillin-resistant Staphylococcus pseudintermedius (MRSP) and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in dogs, through a systematic in vitro assessment of the pharmacodynamic properties of the two drugs. Minimum inhibitory concentrations (MIC) and phenicol resistance genes were determined for 169 S. pseudintermedius and 167 E. coli isolates. Minimum bactericidal concentrations (MBC), time-killing kinetics, and postantibiotic effect (PAE) of both agents against wild-type isolates of each species were assessed. For S. pseudintermedius, the chloramphenicol MIC90 was 32 μg/mL. No florfenicol resistance was detected in this species (MIC90 = 4 μg/mL). The MIC90 of both agents against E. coli was 8 μg/mL. Resistance genes found were catpC221 in S. pseudintermedius and catA1 and/or floR in E. coli. The phenicols displayed a time-dependent, mainly, bacteriostatic effect on both species. Prolonged PAEs were observed for S. pseudintermedius, and no PAEs were detected for E. coli. More research into determination of PK/PD targets of efficacy is needed to further assess the clinical use of chloramphenicol and florfenicol as second-line agents in dogs, optimize dosage regimens, and set up species-specific clinical break points. © 2015 John Wiley & Sons Ltd.

  3. Essential oils and metal ions as alternative antimicrobial agents: a focus on tea tree oil and silver.

    Science.gov (United States)

    Low, Wan-Li; Kenward, Ken; Britland, Stephen T; Amin, Mohd Cim; Martin, Claire

    2017-04-01

    The increasing occurrence of hospital-acquired infections and the emerging problems posed by antibiotic-resistant microbial strains have both contributed to the escalating cost of treatment. The presence of infection at the wound site can potentially stall the healing process at the inflammatory stage, leading to the development of a chronic wound. Traditional wound treatment regimes can no longer cope with the complications posed by antibiotic-resistant strains; hence, there is a need to explore the use of alternative antimicrobial agents. Pre-antibiotic compounds, including heavy metal ions and essential oils, have been re-investigated for their potential use as effective antimicrobial agents. Essential oils have potent antimicrobial, antifungal, antiviral, anti-inflammatory, antioxidant and other beneficial therapeutic properties. Similarly, heavy metal ions have also been used as disinfecting agents because of their broad spectrum activities. Both of these alternative antimicrobials interact with many different intracellular components, thereby resulting in the disruption of vital cell functions and eventually cell death. This review will discuss the application of essential oils and heavy metal ions, particularly tea tree oil and silver ions, as alternative antimicrobial agents for the treatment of chronic, infected wounds. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  4. 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).

  5. 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

  6. Appropriateness of gram-negative agent use at a tertiary care hospital in the setting of significant antimicrobial resistance.

    Science.gov (United States)

    Vora, Neil M; Kubin, Christine J; Furuya, E Yoko

    2015-01-01

    Background.  Practicing antimicrobial stewardship in the setting of widespread antimicrobial resistance among gram-negative bacilli, particularly in urban areas, is challenging. Methods.  We conducted a retrospective cross-sectional study at a tertiary care hospital with an established antimicrobial stewardship program in New York, New York to determine appropriateness of use of gram-negative antimicrobials and to identify factors associated with suboptimal antimicrobial use. Adult inpatients who received gram-negative agents on 2 dates, 1 June 2010 or 1 December 2010, were identified through pharmacy records. Clinical data were collected for each patient. Use of gram-negative agents was deemed optimal or suboptimal through chart review and according to hospital guidelines. Data were compared using χ(2) or Fischer's exact test for categorical variables and Student t test or Mann-Whitney U test for continuous variables. Results.  A total of 356 patients were included who received 422 gram-negative agents. Administration was deemed suboptimal in 26% of instances, with the most common reason being spectrum of activity too broad. In multivariable analysis, being in an intensive care unit (adjusted odds ratio [aOR], .49; 95% confidence interval [CI], .29-.84), having an infectious diseases consultation within the previous 7 days (aOR, .52; 95% CI, .28-.98), and having a history of multidrug-resistant gram-negative bacilli within the past year (aOR, .24; 95% CI, .09-.65) were associated with optimal gram-negative agent use. Beta-lactam/beta-lactamase inhibitor combination drug use (aOR, 2.6; 95% CI, 1.35-5.16) was associated with suboptimal use. Conclusions.  Gram-negative agents were used too broadly despite numerous antimicrobial stewardship program activities.

  7. 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.

  8. Tri- and tetra-nuclear polypyridyl ruthenium(II) complexes as antimicrobial agents.

    Science.gov (United States)

    Gorle, Anil K; Feterl, Marshall; Warner, Jeffrey M; Wallace, Lynne; Keene, F Richard; Collins, J Grant

    2014-11-28

    A series of inert tri- and tetra-nuclear polypyridylruthenium(II) complexes that are linked by the bis[4(4'-methyl-2,2'-bipyridyl)]-1,n-alkane ligand ("bb(n)" for n = 10, 12 and 16) have been synthesised and their potential as antimicrobial agents examined. Due to the modular nature of the synthesis of the oligonuclear complexes, it was possible to make both linear and non-linear tetranuclear ruthenium species. The minimum inhibitory concentrations (MIC) of the ruthenium(II) complexes were determined against four strains of bacteria--Gram positive Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA), and Gram negative Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). In order to gain an understanding of the relative antimicrobial activities, the cellular uptake and water-octanol partition coefficients (log P) were determined for a selection of the ruthenium complexes. Although the trinuclear complexes were the most lipophilic based upon log P values and showed the greatest cellular uptake, the linear tetranuclear complexes were generally more active, with MIC values complexes were slightly more lipophilic and were taken up to a greater extent by the bacteria, they were consistently less active than their linear counterparts. Of particular note, the cellular accumulation of the oligonuclear ruthenium complexes was greater in the Gram negative strains compared to that in the Gram positive S. aureus and MRSA. The results demonstrate that the lower antimicrobial activity of polypyridylruthenium(II) complexes towards Gram negative bacteria, particularly P. aeruginosa, is not strongly correlated to the cellular accumulation but rather to a lower intrinsic ability to kill the Gram negative cells.

  9. Bacterial resistance to antimicrobial agents and its impact on veterinary and human medicine.

    Science.gov (United States)

    Schwarz, Stefan; Loeffler, Anette; Kadlec, Kristina

    2017-02-01

    Antimicrobial resistance has become a major challenge in veterinary medicine, particularly in the context of bacterial pathogens that play a role in both humans and animals. This review serves as an update on acquired resistance mechanisms in bacterial pathogens of human and animal origin, including examples of transfer of resistant pathogens between hosts and of resistance genes between bacteria. Acquired resistance is based on resistance-mediating mutations or on mobile resistance genes. Although mutations are transferred vertically, mobile resistance genes are also transferred horizontally (by transformation, transduction or conjugation/mobilization), contributing to the dissemination of resistance. Mobile genes specifying any of the three major resistance mechanisms - enzymatic inactivation, reduced intracellular accumulation or modification of the cellular target sites - have been found in a variety of bacteria that may be isolated from animals. Such resistance genes are associated with plasmids, transposons, gene cassettes, integrative and conjugative elements or other mobile elements. Bacteria, including zoonotic pathogens, can be exchanged between animals and humans mainly via direct contact, but also via dust, aerosols or foods. Proof of the direction of transfer of resistant bacteria can be difficult and depends on the location of resistance genes or mutations in the chromosomal DNA or on a mobile element. The wide variety in resistance and resistance transfer mechanisms will continue to ensure the success of bacterial pathogens in the future. Our strategies to counteract resistance and preserve the efficacy of antimicrobial agents need to be equally diverse and resourceful. © 2016 ESVD and ACVD.

  10. Effect of Antimicrobial Agents on MinD Protein Oscillations in E. coli Bacterial Cells

    Science.gov (United States)

    Kelly, Corey; Giuliani, Maximiliano; Dutcher, John

    2012-02-01

    The pole-to-pole oscillation of MinD proteins in E. coli cells determines the location of the division septum, and is integral to healthy cell division. It has been shown previously that the MinD oscillation period is approximately 40 s for healthy cells [1] but is strongly dependant on environmental factors such as temperature, which may place stress on the cell [2,3]. We use a strain of E. coli in which the MinD proteins are tagged with green fluorescent protein (GFP), allowing fluorescence visualization of the MinD oscillation. We use high-resolution total internal reflection fluorescence (TIRF) microscopy and a custom, temperature controlled flow cell to observe the effect of exposure to antimicrobial agents on the MinD oscillation period and, more generally, to analyze the time variation of the spatial distribution of the MinD proteins within the cells. These measurements provide insight into the mechanism of antimicrobial action. [1] Raskin, D.M.; de Boer, P. (1999) Proc. Natl. Acad. Sci. 96: 4971-4976. [2] Touhami, A.; Jericho, M; Rutenberg, A. (2006) J. Bacteriol. 188: 7661-7667. [3] Downing, B.; Rutenberg, A.; Touhami, A.; Jericho, M. (2009) PLoS ONE 4: e7285.

  11. 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.

  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. Allicin-inspired pyridyl disulfides as antimicrobial agents for multidrug-resistant Staphylococcus aureus.

    Science.gov (United States)

    Sheppard, Jordan G; McAleer, Jeremy P; Saralkar, Pushkar; Geldenhuys, Werner J; Long, Timothy E

    2018-01-01

    A chemical library comprised of nineteen synthesized pyridyl disulfides that emulate the chemical reactivity of allicin (garlic) was evaluated for antimicrobial activity against a panel of pathogenic bacteria. Gram-positive species including vancomycin-intermediate and vancomycin-resistant Staphylococcus aureus (VISA, VRSA) demonstrated the highest level of susceptibility toward analogs with S-alkyl chains of 7-9 carbons in length. Further biological studies revealed that the disulfides display synergy with vancomycin against VRSA, cause dispersal of S. aureus biofilms, exhibit low cytotoxicity, and decelerate S. aureus metabolism. In final analysis, pyridyl disulfides represent a novel class of mechanism-based antibacterial agents that have a potential application as antibiotic adjuvants in combination therapy of S. aureus infections with reduced vancomycin susceptibility. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. Synthesis and biological evaluation of 2-aminoimidazole/carbamate hybrid anti-biofilm and anti-microbial agents.

    Science.gov (United States)

    Rogers, Steven A; Lindsey, Erick A; Whitehead, Daniel C; Mullikin, Trey; Melander, Christian

    2011-02-15

    The successful marriage of structural features from our 2-aminoimidazole and menthyl carbamate classes of anti-biofilm agents has resulted in the development of a novel hybrid scaffold of biofilm modulators. The compounds were evaluated against a panel of four bacterial strains for anti-biofilm and anti-microbial activity. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. 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...

  20. Consumer-mediated nutrient recycling is influenced by interactions between nutrient enrichment and the anti-microbial agent triclosan

    Science.gov (United States)

    Triclosan (5-chloro-2-(2, 4-dichlorophenoxy)phenol) is a widely used antimicrobial agent in personal care products whose fate and transport in aquatic ecosystems is a growing environmental concern. Evidence for chronic ecological effects of triclosan in aquatic organisms is increasing. At larger sca...

  1. Efficacy of Natural and Allopathic Antimicrobial Agents Incorporated onto Guided Tissue Regeneration Membrane Against Periodontal Pathogens: An in vitro Study.

    Science.gov (United States)

    Mehrotra, Neha; Reddy Palle, Ajay; Kumar Gedela, Rajani; Vasudevan, Sanjay

    2017-01-01

    Periodontal disease is one of the most prevalent afflictions worldwide. It is an infection of the periodontium as a result of subgingival colonization of the specific microbiota, leading to loss of attachment, which requires optimal care for regeneration to its pre-disease state. Guided Tissue Regeneration (GTR) is one of the successful treatment modalities in Periodontal Regenerative Therapy, but is vulnerable to bacterial colonization. The conflict between usage of classical antibiotics and plant origin antimicrobial agents has recently been in the limelight. The aim of this study was to assess the in vitro antimicrobial activity of amoxicillin, metronidazole and green coffee extract loaded onto GTR membrane against periodonto-pathogens. Pure form of amoxicillin, metronidazole and green coffee extract were obtained. One percent concentration of each antimicrobial agent was prepared by appropriate dilution with distilled water. GTR membrane was cut into a size of 1x0.5 cm under sterile conditions and was coated with the antimicrobial agents respectively and with distilled water as the negative control. Antimicrobial activity was checked against Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) and Porphyromonas gingivalis (P. gingivalis) using agar disc diffusion method. The statistical analysis was done using Kruskal Wallis ANOVA and Mann-Whitney U test. One percent amoxicillin showed level of significance (p>0.05) against both A. actinomycetemcomitans and P. gingivalis. Green coffee extract showed no zone of inhibition against both the bacterial species. Loading of commercially available antimicrobial agents onto GTR membrane can prevent its bacterial colonization leading to better treatment outcomes for periodontal regeneration.

  2. Chewing gum of antimicrobial decapeptide (KSL) as a sustained antiplaque agent: preformulation study.

    Science.gov (United States)

    Na, Dong Hee; Faraj, Jabar; Capan, Yilmaz; Leung, Kai P; DeLuca, Patrick P

    2005-09-20

    The purpose of this study was to investigate the potential of KSL, an antimicrobial decapeptide, which has been shown to inhibit the growth of oral bacterial strains associated with caries development and plaque formation, to act as an antiplaque agent in a chewing gum formulation. A reversed-phase high-performance liquid chromatography method was developed for KSL and found to be stability-indicating. KSL was stable in acetate buffer at pH 4 and artificial saliva. On the affinity of KSL to tooth-like materials, the KSL showed favorable interaction with hydroxyapatite discs pretreated with human saliva. A chewing gum formulation of KSL was prepared based on conventional procedures and the release of KSL from the gum was studied in vitro using the chewing apparatus and in vivo by a chew-out method. The gum formulations showed promising in vitro/in vivo release profiles, in which 70-80% KSL was released in a sustained manner over 20 min of chewing time. This study suggests that KSL in a gum formulation is suitable for the delivery in the oral cavity, thereby serving as a novel antiplaque agent.

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

    Science.gov (United States)

    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

    2013-11-01

    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 of evidence for the use of each agent, in each setting, was assigned a level of evidence. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, or no guideline possible. A recommendation was developed in favor of patient-controlled analgesia with morphine in hematopoietic stem cell transplant (HSCT) patients. Suggestions were developed in favor of transdermal fentanyl in standard dose chemotherapy and HSCT patients and morphine mouth rinse and doxepin rinse in head and neck radiation therapy (H&N RT) patients. Recommendations were developed against the use of topical antimicrobial agents for the prevention of mucositis. These included recommendations against the use of iseganan for mucositis prevention in HSCT and H&N RT and against the use of antimicrobial lozenges (polymyxin-tobramycin-amphotericin B lozenges/paste and bacitracin-clotrimazole-gentamicin lozenges) for mucositis prevention in H&N RT. Recommendations were developed against the use of the mucosal coating agent sucralfate for the prevention or treatment of chemotherapy-induced or radiation-induced OM. No guidelines were possible for any other agent due to insufficient and/or conflicting evidence. Additional well-designed research is needed on prevention and management approaches for OM.

  4. 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

  5. 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.

  6. 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.

  7. Establishing the Minimal Bactericidal Concentration of an Antimicrobial Agent for Planktonic Cells (MBC-P) and Biofilm Cells (MBC-B)

    Science.gov (United States)

    Mah, Thien-Fah

    2014-01-01

    This protocol allows for a direct comparison between planktonic and biofilm resistance for a bacterial strain that can form a biofilm in vitro. Bacteria are inoculated into the wells of a 96-well microtiter plate. In the case of the planktonic assay, serial dilutions of the antimicrobial agent of choice are added to the bacterial suspensions. In the biofilm assay, once inoculated, the bacteria are left to form a biofilm over a set period of time. Unattached cells are removed from the wells, the media is replenished and serial dilutions of the antimicrobial agent of choice are added. After exposure to the antimicrobial agent, the planktonic cells are assayed for growth. For the biofilm assay, the media is refreshed with fresh media lacking the antimicrobial agent and the biofilm cells are left to recover. Biofilm cell viability is assayed after the recovery period. The MBC-P for the antimicrobial agent is defined as the lowest concentration of drug that kills the cells in the planktonic culture.  In contrast, the MBC-B for a strain is determined by exposing preformed biofilms to increasing concentrations of antimicrobial agent for 24 hr. The MBC-B is defined as the lowest concentration of antimicrobial agent that kills the cells in the biofilm. PMID:24430536

  8. Evaluation of antimicrobial and physical properties of orthodontic composite resin modified by addition of antimicrobial agents--an in-vitro study.

    Science.gov (United States)

    Sehgal, Vikas; Shetty, V Surendra; Mogra, Subraya; Bhat, Gopalkrishna; Eipe, Montu; Jacob, Shery; Prabu, Laxman

    2007-04-01

    This study was designed to investigate the antimicrobial and physical properties of orthodontic composite resin modified by the addition of antimicrobial agents. Unite bonding adhesive (3M Unitek, Monrovia, Calif), a chemically cured composite resin, modified by the addition of benzalkonium chloride (BAC), chlorhexidine, and triclosan in concentrations of 0.1 wt%, 0.2 wt%, and 0.3 wt%, respectively, was formed into tablets for testing. The tablets of each group and a control group were subjected to the agar plate diffusion test to measure the zone of bacterial inhibition. In addition, they were incubated for 24 hours in tryptic soy broth inoculated with Streptococcus mutans and examined for bacterial growth. A total of 80 extracted premolars were collected and divided into 2 sets of 40 teeth each. Stainless steel Begg brackets were bonded by using control and experimental composites. A universal testing machine was used to determine shear bond strength. The first set of teeth was tested after 24 hours and the second set after 25 days of storage in distilled water. Time-dependent release of antimicrobial agents from the modified composites was monitored spectrophotometrically. The findings indicated that (1) addition of BAC to the orthodontic composite resin enhanced its antimicrobial properties, (2) there was no significant difference in the bond strengths of the control and the experimental resin tested after 24 hours and 25 days, and (3) maximum release of BAC from the modified resin was higher than that of chlorhexidine or triclosan, and was much higher than the minimum inhibitory concentration level.

  9. Evidence of an association between use of anti-microbial agents in food animals and anti-microbial resistance among bacteria isolated from humans and the human health consequences of such resistance.

    Science.gov (United States)

    Angulo, F J; Nargund, V N; Chiller, T C

    2004-01-01

    Several lines of evidence indicate that the use of anti-microbial agents in food animals is associated with anti-microbial resistance among bacteria isolated from humans. The use of anti-microbial agents in food animals is most clearly associated with anti-microbial resistance among Salmonella and Campylobacter isolated from humans, but also appears likely among enterococci, Escherichia coli and other bacteria. Evidence is also accumulating that the anti-microbial resistance among bacteria isolated from humans could be the result of using anti-microbial agents in food animals and is leading to human health consequences. These human health consequences include: (i) infections that would not have otherwise occurred and (ii) increased frequency of treatment failures and increased severity of infection. Increased severity of infection includes longer duration of illness, increased frequency of bloodstream infections, increased hospitalization and increased mortality. Continued work and research efforts will provide more evidence to explain the connection between the use of anti-microbial agents in food animals and anti-microbial-resistant infections in humans. One particular focus, which would solidify this connection, is to understand the factors that dictate spread of resistance determinants, especially resistant genes. With continued efforts on the part of the medical, veterinary and public health community, such research may contribute to more precise guidelines on the use of anti-microbials in food animals.

  10. 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.

  11. Synthesis and Biological Evaluation of 2-Aminobenzamide Derivatives as Antimicrobial Agents: Opening/Closing Pharmacophore Site

    Directory of Open Access Journals (Sweden)

    Yahia N. Mabkhot

    2014-03-01

    Full Text Available A series of new 2-aminobenzamide derivatives (1–10 has been synthesized in good to excellent yields by adopting both conventional and/or a time-efficient microwave assisted methodologies starting from isatoic anhydride (ISA and characterized on the basis of their physical, spectral and microanalytical data. Selected compounds of this series were then tested against various bacterial (Bacillus subtilis (RCMB 000107 and Staphylococcus aureus (RCMB 000106. Pseudomonas aeruginosa (RCMB 000102 and Escherichia coli (RCMB 000103 and fungal strains (Saccharomyces cerevisiae (RCMB 006002, Aspergillus fumigatus (RCMB 002003 and Candida albicans (RCMB 005002 to explore their potential as antimicrobial agents. Compound 5 was found to be the most active compound among those tested, which showed excellent antifungal activity against Aspergillus fumigatus (RCMB 002003 more potent than standard Clotrimazole, and moderate to good antibacterial and antifungal activity against most of the other strains of bacteria and fungi. Furthermore, potential pharmacophore sites were identified and their activity was related with the structures in the solution.

  12. Assessment of spermicidal activity of the antimicrobial peptide sarcotoxin Pd: A potent contraceptive agent.

    Science.gov (United States)

    Zare-Zardini, Hadi; Fesahat, Farzaneh; Anbari, Fatemeh; Halvaei, Iman; Ebrahimi, Leila

    2016-01-01

    In searching for new spermicidal microbicides for use in the prevention of unplanned pregnancy and sexually transmitted infections (STIs) we investigated the spermicidal and cytotoxicity activities of the antimicrobial peptide sarcotoxin Pd. Washed sperm from 10 healthy, normal volunteers was treated with different concentrations of sarcotoxin Pd. Sperm motility and morphology were assessed at 0, 0.3, 5, 10 and 15 min. The cytotoxicity of sarcotoxin Pd in normal human cervical HeLa cells was measured. Percentage cell survival was expressed as the number of live cells in the test group. The cytotoxic effect of sarcotoxin Pd was concentration-dependent. Significant cytotoxicity was observed at concentrations above 24 μg/ml. Sarcotoxin Pd immobilised 100% of spermatozoa at a dose of 90 and 80 μg/ml after 0.3 and 5 min, respectively, and immobilised 50% of spermatozoa after 15 min at lower doses. Sarcotoxin Pd inhibited sperm motility in a dose-dependent manner. The peptide immobilised sperm within 20 s at its maximal effective concentration of 90 μg/ml. Sarcotoxin Pd appears to be a good candidate for a contraceptive agent in the prevention of unplanned pregnancy and STIs.

  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. 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.

  15. 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.

  16. 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.

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

    Science.gov (United States)

    2013-01-01

    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. PMID:23800329

  18. 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.

  19. Synthesis, biological evaluation and molecular modeling of novel thienopyrimidinone and triazolothienopyrimidinone derivatives as dual anti-inflammatory antimicrobial agents.

    Science.gov (United States)

    Bekhit, Adnan A; Farghaly, Ahmed M; Shafik, Ragab M; Elsemary, Mona M A; Bekhit, Alaa El-Din A; Guemei, Aida A; El-Shoukrofy, Mai S; Ibrahim, Tamer M

    2018-04-01

    New thienopyrimidinone and triazolothienopyrimidinone derivatives have been synthesized. These compounds were subjected to anti-inflammatory and antimicrobial activity screening aiming to identify new candidates that have dual anti-inflammatory and antimicrobial activities. Compounds 5, 7 and 10a showed minimal ulcerogenic effect and high selectivity towards human recombinant COX-2 over COX-1 enzyme. Their docking outcome correlated with their biological activity and assured the high selectivity binding towards COX-2. In addition, they could act safely up to 80 mg/kg orally or 40 mg/kg parentrally. The antimicrobial screening showed that compound 10a displayed distinctive inhibitory effect on the growth of Escherichia coli comparable to that of ampicillin. Moreover, compounds 5, 7, 9 and 12a possessed 50% of the inhibitory activity of ampicillin against E. coli. Thus, compounds 5, 7 and 10a represent promising dual acting anti-inflammatory and antimicrobial agents. This work provides rewarding template enriching the chemical space for dual anti-inflammatory anti-microbial activities. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. The role of spices and lactic acid bacteria as antimicrobial agent to extend the shelf life of metata ayib (traditional Ethiopian spiced fermented cottage cheese)

    OpenAIRE

    Geremew, Tsehayneh; Kebede, Ameha; Andualem, Berhanu

    2015-01-01

    Spices and lactic acid bacteria have natural antimicrobial substances and organic compounds having antagonistic activity against microorganisms. The objective of this study was to investigate the role of spices and lactic acid bacteria as antimicrobial agent to extend the shelf life of metata ayib. Antimicrobial activities of spices and lactic acid bacteria (LAB) filtrates were determined by agar well diffusion method against E. coli, S. aureus, S. flexneri and S. peumoniae. Aantimicrobial ac...

  1. Synthesis and biological evaluation of a novel series of chalcones incorporated pyrazole moiety as anticancer and antimicrobial agents.

    Science.gov (United States)

    Mohamed, Magda F; Mohamed, Mervat S; Shouman, Samia A; Fathi, Mohamed M; Abdelhamid, Ismail Abdelshafy

    2012-11-01

    A newly synthesized series of chalcone derivatives containing pyrazole rings were synthesized and evaluated for their cytotoxic activities in vitro against several human cancer cell lines. Most of the prepared compounds showed potential cytotoxicity against human breast cancer cell lines MCF-7, HEPG-2, and HCT-116. Also the compounds were evaluated as antimicrobial agents. The three compounds 3, 4, and 5 were proved to be better anticancer agents than the positive standard doxorubicin with IC50 values (4.7, 4.4, and 3.9 μg/ml) against the same human cancer cell lines, whereas compounds 5 and 6 showed the most active antimicrobial compounds in comparison to the other chalcones.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. Plated coating with antimicrobial agent and application; Kokinsei mekki to sono oyo

    Energy Technology Data Exchange (ETDEWEB)

    Hiramatsu, Minoru; Fukuzaki, Satoshi

    1999-11-01

    Needs of society for the plating technology which gives the function of antifouling property and antimicrobial, etc. on the material surface is big. However, the superfluous antimicrobial treatment has been killed to necessary mycorrhizal fungus, when the human lives. In the development of future antimicrobe plating, not only safety to antimicrobial activity and organism but also consideration to the environmental problem are also the important development element. Here, it introduces production technique and antimicrobe product of the antimicrobe plating. (NEDO)

  8. Combination Antimicrobial Nanocomposite Materials for Neutralization of Biological Threat Agents (PREPRINT)

    National Research Council Canada - National Science Library

    Eby, D. M; Farrington, Karen E; Johnson, Glenn R

    2008-01-01

    .... We are exploring approaches that integrate molecules of the innate immune system and nanoscale inorganic materials in order to create novel antimicrobial composites and self-sterilizing coatings...

  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

    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.

  11. 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.

  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. 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

  14. Rhamnolipids as emulsifying agents for essential oil formulations: antimicrobial effect against Candida albicans and methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Haba, Ester; Bouhdid, Samira; Torrego-Solana, Noelia; Marqués, A M; Espuny, M José; García-Celma, M José; Manresa, Angeles

    2014-12-10

    This work examines the influence of essential oil composition on emulsification with rhamnolipids and their use as therapeutic antimicrobial agents against two opportunistic pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans. Rhamnolipids, produced by Pseudomonas aeruginosa, with waste frying oil as the carbon source, were composed of eight rhamnolipid homologues. The rhamnolipid mixture was used to produce emulsions containing essential oils (EOs) of Melaleuca alternifolia, Cinnamomum verum, Origanum compactum and Lavandula angustifolia using the titration method. Ternary phase diagrams were designed to evaluate emulsion stability, which differed depending on the essential oil. The in vitro antimicrobial activity of the EOs alone and the emulsions was evaluated. The antimicrobial activity presented by the essential oils alone increased with emulsification. The surface properties of rhamnolipids contribute to the positive dispersion of EOs and thus increase their availability and antimicrobial activity against C. albicans and S. aureus. Therefore, rhamnolipid-based emulsions represent a promising approach to the development of EO delivery systems. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Identification of 5,6-dihydroimidazo[2,1-b]thiazoles as a new class of antimicrobial agents.

    Science.gov (United States)

    Li, Yangmei; Bionda, Nina; Fleeman, Renee; Wang, Hongjie; Ozawa, Akihiko; Houghten, Richard A; Shaw, Lindsey

    2016-11-01

    In an effort to develop novel antimicrobial agents against drug-resistant bacterial infections, 5,6-dihydroimidazo[2,1-b]thiazole compounds were synthesized and tested for their antimicrobial activity. Eight compounds comprised by two sub-scaffolds were identified as hits against methicillin-resistant Staphylococcus aureus (MRSA). These hits were modified at 6-position by replacing (S)-6 to (R)-6 configuration and the (R)-isomers increased their antimicrobial activities by two-fold. The most active compound showed a MIC 90 value of 3.7μg/mL against MRSA in a standard microdilution bacterial growth inhibitory assay. This compound protected wax moth worms against MRSA at a dose of 5× MIC using a worm infectious model. This compound also exhibited inhibition of DNA gyrase activity in a DNA gyrase supercoil assay, suggesting the 5,6-dihydroimidazo[2,1-b]thiazoles may target DNA gyrase for the antimicrobial action. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Antimicrobial factor from Bacillus amyloliquefaciens inhibits Paenibacillus larvae, the causative agent of American foulbrood.

    Science.gov (United States)

    Benitez, Lisianne Brittes; Velho, Renata Voltolini; de Souza da Motta, Amanda; Segalin, Jéferson; Brandelli, Adriano

    2012-03-01

    Bacillus amyloliquefaciens LBM 5006 produces an antimicrobial factor active against Paenibacillus larvae, a major honeybee pathogen. The antagonistic effect and the mode of action of the antimicrobial factor were investigated. The antibacterial activity was produced starting at mid-logarithmic growth phase, reaching its maximum during the stationary phase. Exposure of cell suspensions of P. larvae to this antimicrobial resulted in loss of cell viability and reduction in optical density associated with cell lysis. Scanning electron microscopy showed damaged cell envelope and loss of protoplasmic material. The antimicrobial factor was stable for up to 80°C, but it was sensitive to proteinase K and trypsin. Mass spectrometry analysis indicates that the antimicrobial activity is associated with iturin-like peptides. The antimicrobial factor from B. amyloliquefaciens LBM 5006 showed a bactericidal effect against P. larvae cells and spores. This is the first report on iturin activity against P. larvae. This antimicrobial presents potential for use in the control of American foulbrood disease.

  17. 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.

  18. [In vitro activity of 16 antimicrobial agents against Helicobacter (Campylobacter) pylori].

    Science.gov (United States)

    García-Rodríguez, J A; García-García, M I; García-Sánchez, E; García-Sánchez, J E; Muñoz Bellido, J L

    1989-12-01

    Campylobacter pylori has been associated with the etiology of gastritis and duodenal ulcer. It has been shown that several drugs, among them a variety of antimicrobials, eliminate C. pylori from gastric mucosa at least for a time, resulting in an improvement of the patients' symptoms. The activity of 16 antimicrobials (ampicillin, cefazolin, cefuroxime, cefotaxime, imipenem, aztreonam, tigemonam, erythromycin, vancomycin, nalidixic acid, colistin , norfloxacin, ciprofloxacin, difloxacin, ofloxacin and perfloxacin) was tested against 30 clinical isolates of C. pylori. The antimicrobials showing the highest activity were ampicillin, imipenem and ciprofloxacin, followed by cefazolin, cefuroxime, cefotaxime, aztreonam, tigemonam, erythromycin and difloxacin. Nalidixic acid, colistin and vancomycin were virtually ineffective against C. pylori.

  19. 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

  20. 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.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Discovery of membrane active benzimidazole quinolones-based topoisomerase inhibitors as potential DNA-binding antimicrobial agents.

    Science.gov (United States)

    Zhang, Ling; Addla, Dinesh; Ponmani, Jeyakkumar; Wang, Ao; Xie, Dan; Wang, Ya-Nan; Zhang, Shao-Lin; Geng, Rong-Xia; Cai, Gui-Xin; Li, Shuo; Zhou, Cheng-He

    2016-03-23

    A series of novel benzimidazole quinolones as potential antimicrobial agents were designed and synthesized. Most of the prepared compounds exhibited good or even stronger antimicrobial activities in comparison with reference drugs. The most potent compound 15m was membrane active and did not trigger the development of resistance in bacteria. It not only inhibited the formation of biofilms but also disrupted the established Staphylococcus aureus and Escherichia coli biofilms. It was able to inhibit the relaxation activity of E. coli topoisomerase IV at 10 μM concentration. Moreover, this compound also showed low toxicity against mammalian cells. Molecular modeling and experimental investigation of compound 15m with DNA suggested that this compound could effectively bind with DNA to form a steady 15m-DNA complex which might further block DNA replication to exert the powerful bioactivities. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Ecotoxicity and screening level ecotoxicological risk assessment of five antimicrobial agents: triclosan, triclocarban, resorcinol, phenoxyethanol and p-thymol.

    Science.gov (United States)

    Tamura, Ikumi; Kagota, Kei-Ichiro; Yasuda, Yusuke; Yoneda, Saori; Morita, Junpei; Nakada, Norihide; Kameda, Yutaka; Kimura, Kumiko; Tatarazako, Norihisa; Yamamoto, Hiroshi

    2013-11-01

    Acute and chronic (or sub-chronic) toxicity of five selected antimicrobial agents, including triclosan (TCS), triclocarban (TCC), resorcinol, phenoxyethanol and p-thymol, was investigated using the conventional three-aquatic-organism battery. These compounds are widely used in cosmetics and other personal care products and their ecological risk has recently become a significant concern. As results of toxicity tests, TCS was found to be most strongly toxic for green algae [e.g. 72 h no observed effect concentration (NOEC) of 0.50 µg l(-1) ] among the selected compounds, followed by TCC, while TCC was more toxic or similar to TCS for Daphnia and fish (e.g. Daphnia 8 day NOEC of 1.9 µg l(-1) ). Having compared the predicted no effect concentration (PNEC) determined from the toxicity data with measured environmental concentrations (MEC), the preliminary ecological risk assessment of these five antimicrobials was conducted. The MEC/PNEC ratios of TCS and TCC were over 1 for some monitoring data, especially in urban streams with watershed areas without sewage service coverage, and their potential risk for green algae and Daphnia might be at a level of concern, although the contribution of TCS/TCC on the total toxicity of the those sites needs to be further investigated. For the three other antimicrobials, the maximum MEC/PNEC ratio for resorcinol was 0.1-1, but those for phenoxyethanol and p-thymol were <0.1 and their risk to aquatic organisms is limited, although the additive effects with TCS, TCC and other antimicrobial agents, such as parabens, need to be further examined in future studies. Copyright © 2012 John Wiley & Sons, Ltd.

  5. 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

  6. Antimicrobial susceptibility of 6 antimicrobial agents in Helicobacter pylori clinical isolates by using EUCAST breakpoints compared with previously used breakpoints.

    Science.gov (United States)

    Alarcón, Teresa; Urruzuno, Pedro; Martínez, Maria Josefa; Domingo, Diego; Llorca, Laura; Correa, Ana; López-Brea, Manuel

    2017-05-01

    The aim of this study was to determine the differences in percentage resistance in H. pylori clinical isolates using EUCAST breakpoints compared with previously used breakpoints. MIC value distribution in H. pylori clinical isolates was also studied. Susceptibility to amoxicillin, tetracycline, metronidazole, clarithromycin, rifampicin and levofloxacin was performed by E-test in 824 H. pylori clinical isolates. EUCAST and previous breakpoints defined resistance as follows: MIC >0.12mg/L and ≥2mg/L for amoxicillin, >8mg/L and ≥8mg/L for metronidazole, >0.5mg/L and ≥1mg/L for clarithromycin, >1mg/L and ≥32mg/L for rifampicin, and >1mg/L and ≥4mg/L for tetracycline and >1mg/L levofloxacin. Overall resistance rate by EUCAST and by previous breakpoints was 8.5% and 3.2% for amoxicillin, 0.6% and 0.1% for tetracycline, 39.2% and 39.7% for metronidazole, 51.2% and 51.2% for clarithromycin, 32% and 3.1% for rifampicin, and 6.7% and 6.7% for levofloxacin. When using the different breakpoints for antimicrobial susceptibility testing, similar results were found with most antibiotics tested (tetracycline, metronidazole, clarithromycin, and levofloxacin), except for amoxicillin and rifampicin. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  7. 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.

  8. 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.

  9. Impact of reporting gram stain results from blood culture bottles on the selection of antimicrobial agents.

    Science.gov (United States)

    Uehara, Yuki; Yagoshi, Michiko; Tanimichi, Yumiko; Yamada, Hiroko; Shimoguchi, Kazuo; Yamamoto, Sachiyo; Yanai, Mitsuru; Kumasaka, Kazunari

    2009-07-01

    We assessed the usefulness of reporting direct blood Gram stain results compared with the results of positive blood cultures in 482 episodes and monitored impact on selection of antimicrobial treatment. We found that the reporting groups "Staphylococcus spp," "Pseudomonas spp and related organisms," and "yeasts" identified in this way matched perfectly with later culture identification. When the report indicated Staphylococcus spp or Pseudomonas spp and related organisms, physicians started or changed antimicrobials suitable for these bacteria more frequently than when "other streptococci" and "family Enterobacteriaceae" were reported (P Gram stain results that definitively identify Staphylococcus spp, Pseudomonas spp and related organisms, and yeasts reliably can be rapidly provided by clinical laboratories; this information has a significant impact on early selection of effective antimicrobials. Further investigation is needed to assess the clinical impact of reporting Gram stain results in bacteremia.

  10. In Vitro ADME Properties of Two Novel Antimicrobial Peptoid-Based Compounds as Potential Agents against Canine Pyoderma

    Directory of Open Access Journals (Sweden)

    Ines Greco

    2018-03-01

    Full Text Available Antimicrobial peptides (AMPs hold promise as the next generation of antimicrobial agents, but often suffer from rapid degradation in vivo. Modifying AMPs with non-proteinogenic residues such as peptoids (oligomers of N-alkylglycines provides the potential to improve stability. We have identified two novel peptoid-based compounds, B1 and D2, which are effective against the canine skin pathogen Staphylococcus pseudintermedius, the main cause of antibiotic use in companion animals. We report on their potential to treat infections topically by characterizing their release from formulation and in vitro ADME properties. In vitro ADME assays included skin penetration profiles, stability to proteases and liver microsomes, and plasma protein binding. Both B1 and D2 were resistant to proteases and >98% bound to plasma proteins. While half-lives in liver microsomes for both were >2 h, peptoid D2 showed higher stability to plasma proteases than the peptide-peptoid hybrid B1 (>2 versus 0.5 h. Both compounds were suitable for administration in an oil-in-water cream formulation (50% release in 8 h, and displayed no skin permeation, in the absence or presence of skin permeability modifiers. Our results indicate that these peptoid-based drugs may be suitable as antimicrobials for local treatment of canine superficial pyoderma and that they can overcome the inherent limitations of stability encountered in peptides.

  11. 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.

  12. 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

  13. 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.

  14. Natural antimicrobial/antioxidant agents in meat and poultry products as well as fruits and vegetables: A review.

    Science.gov (United States)

    Aziz, Marya; Karboune, Salwa

    2018-02-11

    Synthetic preservatives are widely used by the food industry to control the growth of spoilage and pathogenic microorganisms and to inhibit the process of lipid oxidation extending the shelf-life, quality and safety of food products. However, consumer's preference for natural food additives and concern regarding the safety of synthetic preservatives prompted the food industry to look for natural alternatives. Natural antimicrobials, including plant extracts and their essential oils, enzymes, peptides, bacteriocins, bacteriophages, and fermented ingredients have all been shown to have the potential for use as alternatives to chemical antimicrobials. Some spices, herbs and other plant extracts were also reported to be strong antioxidants. The antimicrobial/antioxidant activities of some plant extracts and/or their essential oils are mainly due to the presence of some major bioactive compounds, including phenolic acids, terpenes, aldehydes, and flavonoids. The proposed mechanisms of action of these natural preservatives are reported. An overview of the research done on the direct incorporation of natural preservatives agents into meat and poultry products as well as fruit and vegetables to extend their shelf-life is presented. The development of edible packaging materials containing natural preservatives is growing and their applications in selected food products are also presented in this review.

  15. Zinc Oxide Nanorods-Decorated Graphene Nanoplatelets: A Promising Antimicrobial Agent against the Cariogenic Bacterium Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Elena Zanni

    2016-09-01

    Full Text Available Nanomaterials are revolutionizing the field of medicine to improve the quality of life due to the myriad of applications stemming from their unique properties, including the antimicrobial activity against pathogens. In this study, the antimicrobial and antibiofilm properties of a novel nanomaterial composed by zinc oxide nanorods-decorated graphene nanoplatelets (ZNGs are investigated. ZNGs were produced by hydrothermal method and characterized through field-emission scanning electron microscopy (FE-SEM, energy-dispersive X-ray spectroscopy (EDX and X-ray diffraction (XRD techniques. The antimicrobial activity of ZNGs was evaluated against Streptococcus mutans, the main bacteriological agent in the etiology of dental caries. Cell viability assay demonstrated that ZNGs exerted a strikingly high killing effect on S. mutans cells in a dose-dependent manner. Moreover, FE-SEM analysis revealed relevant mechanical damages exerted by ZNGs at the cell surface of this dental pathogen rather than reactive oxygen species (ROS generation. In addition, inductively coupled plasma mass spectrometry (ICP-MS measurements showed negligible zinc dissolution, demonstrating that zinc ion release in the suspension is not associated with the high cell mortality rate. Finally, our data indicated that also S. mutans biofilm formation was affected by the presence of graphene-zinc oxide (ZnO based material, as witnessed by the safranin staining and growth curve analysis. Therefore, ZNGs can be a remarkable nanobactericide against one of the main dental pathogens. The potential applications in dental care and therapy are very promising.

  16. 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.

  17. Hydrazides/hydrazones as antimicrobial and anticancer agents in the new millennium.

    Science.gov (United States)

    Kumar, Pradeep; Narasimhan, Balasubramanian

    2013-06-01

    Hydrazide/hydrazone derivatives are of quite interest for medicinal chemists because of their vast spectrum of biological activity. Literature reports reveal that the hydrazide derivatives have been extensively studied for their biological profile during the past decade. The aim of the present work is to collect literature reports focusing the antimicrobial and anticancer study of different hydrazide/hydrazone derivatives carried out during the past decade which will serve as a valuable source of information for the researchers working in the field of antimicrobial and anticancer research.

  18. Novel Antimicrobial Agents: Fluorinated 2-(3-(Benzofuran-2-yl pyrazol-1-ylthiazoles

    Directory of Open Access Journals (Sweden)

    Hanan A. Mohamed

    2013-01-01

    Full Text Available A new series of 2-pyrazolin-1-ylthiazoles 8a–d and 13–16 was synthesized by cyclization of N-thiocarboxamide-2-pyrazoline with different haloketones and 2,3-dichloroquinoxaline. The structures of the new compounds were confirmed by elemental analyses as well as NMR, IR, and mass spectral data. The newly synthesized compounds were evaluated for their antimicrobial activities, and also their minimum inhibitory concentration (MIC against most of test organisms was performed. Amongst the tested ones, compound 8c displayed excellent antimicrobial activity.

  19. 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

    measurements were generated. The total data generated in the trial was used to quantify the intra- and inter-laboratory precisions. The study design also facilitated the investigation of the influence of the source of media and the source of discs on zone sizes. A smaller two-laboratory trial was employed......The precision of the disc diffusion protocols previously published by Alderman and Smith (Aquaculture 196 (2002) 211) was analysed in a seven-laboratory trial using Escherichia coli ATCC 25922 as the test strain. Discs containing seven antimicrobial agents were employed and 2899 zone size...... 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...

  20. Hydrazide?hydrazones as potential antimicrobial agents: overview of the literature since 2010

    OpenAIRE

    Popio?ek, ?ukasz

    2016-01-01

    Hydrazide?hydrazone derivatives are present in many bioactive molecules and display a wide variety of biological activities, such as antibacterial, antitubercular, antifungal, anticancer, anti-inflammatory, anticonvulsant, antiviral, and antiprotozoal action. Therefore, many medicinal chemists synthesize various hydrazide?hydrazones and evaluate them for biological activities. Among biological properties of this class of compounds, antimicrobial activity is the most frequently encountered in ...

  1. Effect of tea tree (Melaleuca alternifolia) oil as a natural antimicrobial agent in lipophilic formulations.

    Science.gov (United States)

    Mantil, Elisabeth; Daly, Grace; Avis, Tyler J

    2015-01-01

    There has been increased interest surrounding the use of tea tree oil (TTO) as a natural antimicrobial. In this study, the antimicrobial activity of TTO and its components were investigated in vitro and in a predominantly lipid-based personal care formulation. In vitro, TTO showed minimal inhibitory concentrations of 0.2% (for Saccharomyces cerevisiae and Pythium sulcatum), 0.4% (for Escherichia coli, Bacillus subtilis, and Rhizopus stolonifer), and 0.8% (for Botrytis cinerea). TTO at 0.08%-0.8% was often as efficient as parabens. Comparison of the antimicrobial activities of TTO components showed that terpinen-4-ol and γ-terpinene were generally most effective in inhibiting microbial growth. TTO activity in a personal care product was evaluated through air and water exposure, artificial inoculation, and shelf life studies. While TTO did not increase shelf life of unopened products, it decreased microbial load in products exposed to water and air. Results from this study support that antimicrobial activity of TTO can be attributed to varying levels of its components and that low levels of TTO were effective in reducing microbial growth during the use of the product. This study showed that TTO can act as a suitable preservative system within an oil-based formulation.

  2. Chitin nanofibers as reinforcing and antimicrobial agents in carboxymethyl cellulose films: Influence of partial deacetylation

    Science.gov (United States)

    The development of edible, environmentally friendly, mechanically strong and antimicrobial biopolymer films for active food packaging has gained considerable interest in recent years. The present work deals with the extraction and deacetylation of chitin nanofibers (ChNFs) from crab shells and their...

  3. 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.

  4. Effect of the addition of antimicrobial agents on Shore A hardness and roughness of soft lining materials.

    Science.gov (United States)

    Urban, Vanessa M; Lima, Thiago F; Bueno, Mirian G; Giannini, Marcelo; Arioli Filho, João N; de Almeida, Ana Lúcia P F; Neppelenbroek, Karin H

    2015-04-01

    While the incorporation of antimicrobial agents into soft denture liners has been suggested as a reliable alternative treatment for denture stomatitis, it may affect the liner's properties. The effect of addition of antimicrobial agents for the treatment of denture stomatitis on the surface roughness and Shore A hardness of soft lining materials was evaluated. The test groups comprised specimens (36 × 7 × 6 mm(3) ) of soft materials (Softone and Trusoft) without (control) or with incorporation of drugs (nystatin, miconazole, ketoconazole, chlorhexidine diacetate, and itraconazole). Hardness (Shore A) and roughness (Ra) were evaluated after immersion of specimens (n = 10) in distilled water at 37°C for 24 hours, 7 and 14 days. Data were analyzed by 3-way ANOVA/Tukey's test (α = 0.05). After 14 days, an increase (p hardness of soft materials with time for the modified specimens, except for itraconazole. Addition of drugs increased the Softone roughness only for the addition of miconazole and chlorhexidine (p hardness and roughness with time in the modified groups compared to controls were observed for itraconazole groups for both materials. © 2014 by the American College of Prosthodontists.

  5. In vitro activities of tulathromycin and ceftiofur combined with other antimicrobial agents using bovine Pasteurella multocida and Mannheimia haemolytica isolates.

    Science.gov (United States)

    Sweeney, Michael T; Brumbaugh, Gordon W; Watts, Jeffrey L

    2008-01-01

    The purpose of this study was to determine the activities of two antibacterial agents used in the treatment of bovine respiratory infections-tulathromycin, a macrolide, and ceftiofur, a third-generation cephalosporin-alone, in combination with each other, and in combination with each of seven additional antibiotics (tilmicosin, florfenicol, enrofloxacin, danofloxacin, ampicillin, tetracycline, and penicillin G) against bovine Pasteurella multocida (n = 60) and Mannheimia haemolytica (n = 10) isolates for determination of synergy, antagonism, or indifference. Of 458 organism-drug combinations, 160 combinations of tulathromycin and 209 combinations of ceftiofur with eight antimicrobial drugs were indifferent. One combination was antagonistic (ceftiofur + florfenicol against one isolate of P. multocida). Time-kill studies showed loss of cidality for ceftiofur when combined with florfenicol at 1x the minimal inhibitory concentration. Overall, the in vitro data demonstrated that tulathromycin and ceftiofur, in combination with each other or seven other antimicrobial agents, primarily produce an indifferent response with no occurrences of synergism and rare occurrences of antagonism.

  6. 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

  7. 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.

  8. Comparative Activity of Several Antimicrobial Agents against Nosocomial Gram-Negative Rods Isolated across Canada

    Directory of Open Access Journals (Sweden)

    Shelley R Scriver

    1995-01-01

    Full Text Available In 1992, a surveillance study was performed in Canada to determine the susceptibility of nosocomial Gram-negative rods to several wide spectrum antimicrobials. Consecutive isolates from 10 institutions, as well as additional strains of selected species of Enterobacteriaceae that are known to possess the Bush group 1 beta-lactamase, were tested for susceptibility to 12 antimicrobials. Third-generation cephalosporin resistance was found to be as high as 29% in Enterobacter cloacae that possesses the Bush group 1 beta-lactamase and less than 4% in those isolates not possessing this enzyme. Cefepime equalled or exceeded the activity of the third-generation cephalosporins against the species of Enterobacteriaceae that demonstrated resistance to the third-generation cephalosporins.

  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. 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.

  12. Susceptibility of Campylobacter Fetus Subsp. Jejuni, Isolated from Patients in Jakarta, Indonesia to Ten Antimicrobial Agents

    Science.gov (United States)

    1981-06-16

    antimicrobials was tested against 28 Campylohacter letus subsp. jejuni isolates cultured from the stools of human gastroenteritis and suspected typhoid fever...isolated from the faeces of gastroenteritis and suspected typhoid fever patients in Jakarta, Indonesia and to compare the MIC values with those...jejuni strains used in this study were cultured from the faeces of 19 gastroenteritis and five suspected typhoid fever patients examined at the

  13. Pharmacokinetic drug-drug interactions between calcineurin inhibitors and proliferation signal inhibitors with anti-microbial agents: implications for therapeutic drug monitoring.

    Science.gov (United States)

    Page, Robert L; Mueller, Scott W; Levi, Marilyn E; Lindenfeld, Joann

    2011-02-01

    Infections account for 15% to 20% of deaths in transplant recipients; thus, rapid and appropriate therapeutic intervention is required. However, many anti-microbial agents can interact significantly with a transplant recipient's immunosuppressive regimen, placing them at risk for a potential adverse drug reaction and prolonged hospitalization. This investigation highlights the pharmacokinetic drug-drug interactions between the calcineurin inhibitors and proliferation signal inhibitors with commonly used anti-microbial agents, specifically addressing mechanism, management, onset of action, magnitude of effect and strength of evidence for each interaction. Copyright © 2011 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  14. Surface Functionalization of Iron Oxide Nanoparticles with Gallic Acid as Potential Antioxidant and Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Syed Tawab Shah

    2017-10-01

    Full Text Available In this research, we report the size-controlled synthesis and surface-functionalization of magnetite with the natural antioxidant gallic acid (GA as a ligand, using in situ and post-synthesis methods. GA functionalization provided narrow size distribution, with an average particle size of 5 and 8 nm for in situ synthesis of gallic acid functionalized magnetite IONP@GA1 and IONP@GA2, respectively, which are ultra-small particles as compared to unfunctionalized magnetite (IONP and post functionalized magnetite IONP@GA3 with average size of 10 and 11 nm respectively. All the IONPs@GA samples were found hydrophilic with stable aggregation state. Prior to commencement of experimental lab work, PASS software was used to predict the biological activities of GA and it is found that experimental antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH assay and antimicrobial studies using well diffusion method are in good agreement with the simulated results. Furthermore, the half maximal inhibitory concentration (IC50 values of DPPH antioxidant assay revealed a 2–4 fold decrease as compared to unfunctionalized IONP. In addition to antioxidant activity, all the three IONP@GA proved outstanding antimicrobial activity while testing on different bacterial and fungal strains. The results collectively indicate the successful fabrication of novel antioxidant, antimicrobial IONP@GA composite, which are magnetically separable, efficient, and low cost, with potential applications in polymers, cosmetics, and biomedical and food industries.

  15. Surface Functionalization of Iron Oxide Nanoparticles with Gallic Acid as Potential Antioxidant and Antimicrobial Agents

    Science.gov (United States)

    Shah, Syed Tawab; Saad, Omar; Simarani, Khanom; Chowdhury, Zaira Zaman; Alhadi, Abeer A.; Al-Ani, Lina A.

    2017-01-01

    In this research, we report the size-controlled synthesis and surface-functionalization of magnetite with the natural antioxidant gallic acid (GA) as a ligand, using in situ and post-synthesis methods. GA functionalization provided narrow size distribution, with an average particle size of 5 and 8 nm for in situ synthesis of gallic acid functionalized magnetite IONP@GA1 and IONP@GA2, respectively, which are ultra-small particles as compared to unfunctionalized magnetite (IONP) and post functionalized magnetite IONP@GA3 with average size of 10 and 11 nm respectively. All the IONPs@GA samples were found hydrophilic with stable aggregation state. Prior to commencement of experimental lab work, PASS software was used to predict the biological activities of GA and it is found that experimental antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and antimicrobial studies using well diffusion method are in good agreement with the simulated results. Furthermore, the half maximal inhibitory concentration (IC50) values of DPPH antioxidant assay revealed a 2–4 fold decrease as compared to unfunctionalized IONP. In addition to antioxidant activity, all the three IONP@GA proved outstanding antimicrobial activity while testing on different bacterial and fungal strains. The results collectively indicate the successful fabrication of novel antioxidant, antimicrobial IONP@GA composite, which are magnetically separable, efficient, and low cost, with potential applications in polymers, cosmetics, and biomedical and food industries. PMID:28981476

  16. 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.

  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. 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)

  19. 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.

  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. Evaluation of bishexadecyltrimethyl ammonium palladium tetrachloride based dual functional colloidal carrier as an antimicrobial and anticancer agent.

    Science.gov (United States)

    Kaur, Gurpreet; Kumar, Sandeep; Dilbaghi, Neeraj; Kaur, Baljinder; Kant, Ravi; Guru, Santosh Kumar; Bhushan, Shashi; Jaglan, Sundeep

    2016-04-21

    We have developed a dual function carrier using bishexadecyltrimethyl ammonium palladium tetrachloride, which has anticancer as well as antibacterial activity, using a ligand insertion method with a simple and easy work procedure. The complex is prepared by a simple and cost effective method using hexadecyltrimethyl ammonium chloride and palladium chloride under controlled stoichiometry. Herein, we report the aggregation (self assembly) of the metallosurfactant having palladium as a counter ion, in aqueous medium along with its binding affinity with bovine serum albumin. The palladium surfactant has exhibited excellent antimicrobial efficacy against fungus and bacteria (both Gram-positive and Gram-negative bacteria). Cytotoxicity of palladium surfactant against cancerous (Human leukemia HL-60, pancreatic MIA-Pa-Ca-2 and prostate cancer PC-3) and healthy cells (fR2 human breast epithelial cells) was also evaluated using MTT assay. The present dual functional moiety shows a low IC50 value and has potential to be used as an anticancer agent. Our dual function carrier which itself possesses antimicrobial and anticancer activity represents a simple and effective system and can also be utilized as a drug carrier in the future.

  2. Radiosensitivities of parabens and characterization of the radical species induced in this class of antimicrobial agents after gamma irradiation

    Science.gov (United States)

    Üstündaǧ, Ilknur; Korkmaz, Özden

    Radiosensitivities of methyl, ethyl, propyl and butyl parabens and sodium salts of methyl and propyl parabens (hereafter, MP, EP, PP, BP, SMP and SPP, respectively) were investigated by monitoring, through electron spin resonance (ESR) spectroscopy, the evolution under different experimental conditions of characteristic features of the radicalic species produced upon irradiation by gamma radiation. While ESR spectra of the studied parabens consisted of the sum of broad and narrow resonance lines of different microwave saturation and thermal characteristics, those of sodium salts appeared to consist of the sum of two overlapping narrow resonance lines. Radical species presented different room and high-temperature decay characteristics, depending on the extent of the cage effect created by the lattice networks on these species. A model based on the presence of two radical species presenting different spectroscopic and kinetic features described best the experimental data collected for parabens and their sodium salts. Radiation yields of the studied parabens towards gamma radiation were calculated to be low (G≤10-2), providing the opportunity of using these antimicrobial agents in food, cosmetics and drugs to be sterilized by radiation without much loss from their antimicrobial activities.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  5. Recent advances in synthetic lipopeptides as anti-microbial agents: designs and synthetic approaches.

    Science.gov (United States)

    Koh, Jun-Jie; Lin, Shuimu; Beuerman, Roger W; Liu, Shouping

    2017-10-01

    Infectious diseases impose serious public health burdens and continue to be a global public health crisis. The treatment of infections caused by multidrug-resistant pathogens is challenging because only a few viable therapeutic options are clinically available. The emergence and risk of drug-resistant superbugs and the dearth of new classes of antibiotics have drawn increasing awareness that we may return to the pre-antibiotic era. To date, lipopeptides have been received considerable attention because of the following properties: They exhibit potent antimicrobial activities against a broad spectrum of pathogens, rapid bactericidal activity and have a different antimicrobial action compared with most of the conventional antibiotics used today and very slow development of drug resistance tendency. In general, lipopeptides can be structurally classified into two parts: a hydrophilic peptide moiety and a hydrophobic fatty acyl chain. To date, a significant amount of design and synthesis of lipopeptides have been done to improve the therapeutic potential of lipopeptides. This review will present the current knowledge and the recent research in design and synthesis of new lipopeptides and their derivatives in the last 5 years.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. 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.

  9. 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.

  10. Stenusine, an antimicrobial agent in the rove beetle genus Stenus (Coleoptera, Staphylinidae)

    Science.gov (United States)

    Lusebrink, Inka; Dettner, Konrad; Seifert, Karlheinz

    2008-08-01

    Stenusine is well known as the alkaloid, discharged by the rove beetle, genus Stenus Latreille (Coleoptera, Staphylinidae). The Stenus beetles employ the alkaloid as an escape mechanism when on water surfaces. In the case of danger, they lower their abdomen and emit stenusine from their pygidial glands. Stenusine shows a low surface tension and therefore a high spreading pressure; these properties propel the beetle quickly over the water. Many Steninae do not live in habitats with open waters, but in detritus, leaf litter, mosses, etc. This raises the possibility that stenusine might also have another function, e.g., as antibiotic or fungicide. Stenus beetles show an intense grooming behaviour. With gas chromatography mass spectrometry analyses we could prove that they cover themselves with their secretion. To tests its antimicrobial properties we conducted agar diffusion tests with stenusine and norstenusine, another substance that is abundant in most Stenus species. Both compounds have an antimicrobial effect on entomopathogenic bacteria and fungi. Stenusine not only allows for an extraordinary method of locomotion on water surfaces, it also protects the Steninae from being infested with microorganisms.

  11. In vitro activity of lauric acid or myristylamine in combination with six antimicrobial agents against methicillin-resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Kitahara, Takashi; Aoyama, Yuko; Hirakata, Yoichi; Kamihira, Shimeru; Kohno, Shigeru; Ichikawa, Nobuhiro; Nakashima, Mikiro; Sasaki, Hitoshi; Higuchi, Shun

    2006-01-01

    The objective of this study was to investigate the in vitro activities of lauric acid and myristylamine in combination with six antimicrobial agents against methicillin-resistant Staphylococcus aureus (MRSA). The combination effect of lipids and antimicrobial agents was evaluated by the checkerboard method to obtain a fractional inhibitory concentration (FIC) index. The effects of lauric acid + gentamicin (GM) and lauric acid + imipenem (IPM) combinations were synergistic against the clinical isolates in 12 combinations. An antagonistic FIC index was observed only with the myristylamine + GM combination. We investigated in detail the antimicrobial activity for two combinations that showed a synergistic effect. The cytotoxicity of lauric acid was not enhanced by the addition of GM and IPM. In time-kill studies, lauric acid + GM and lauric acid + IPM combinations at one-eighth of the minimum inhibitory concentration produced a bacteriostatic effect.

  12. 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.......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...... 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...

  13. 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...

  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. 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.

  16. USING OF ANTIMICROBIAL AGENTS (ESSENTIAL OIL FOR MICROBIOLOGY POULTRY AND ITS PRODUCTS

    Directory of Open Access Journals (Sweden)

    Sulltana Ajçe

    2010-01-01

    Full Text Available Recently there is increasing of the consume of the poultry product in the World and European market. The aboveconsume is now related with the tendency to buy and consume healthy food products. Group of populations thatconsuming poultry products industry searching them safety and guarantee. The pollution of fresh and packagingpoultry meat and other poultry product derives from the environment and from the operating procedures applied in thecompanies of the production. The evaluation of their safety and quality involves also microbiological analysis ofcontrol, as an important part to evaluate and manage the risk, originated from the microbial strains presented there. Inthis framework, there are realized many scientific studies using natural antimicrobials (essential oils, drizzle etc.. toreduce the microbial load of the poultry products.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. Synthesis and Biological Evaluation of Mannich Bases of Isoxazoline Derivatives as Novel Anti-Microbial Agents

    Directory of Open Access Journals (Sweden)

    Pawar Sudhir

    2012-01-01

    Full Text Available A novel series of compounds were synthesized by condensation reaction of substituted acetophenone (1a-b with substituted aldehyde (2a-b in presence of alcoholic sodium hydroxide to get intermediate chalcones (3a-c, which were further treated with hydroxylamine hydrochloride in presence of sodium hydroxide to get isoxazolines derivatives (4a-c. The latter were refluxed with substituted primary amines and formaldehyde for 6-10 h to afford Mannich bases. The synthesized compounds were characterized on the basis of their spectral (IR, 1HNMR data and evaluated for the antimicrobial activity by using Zone of Inhibition by cup plate method and Minimum Inhibitory Concentration by broth dilution method.

  20. Further investigation of inhibitors of MRSA pyruvate kinase: Towards the conception of novel antimicrobial agents.

    Science.gov (United States)

    Labrière, Christophe; Gong, Huansheng; Finlay, B Brett; Reiner, Neil E; Young, Robert N

    2017-01-05

    Several novel series of compounds were synthesized and evaluated as inhibitors of methicillin-resistant Staphylococcus aureus (MRSA) pyruvate kinase (PK). PK has been identified as a highly interconnected essential 'hub' protein in MRSA, with structural features distinct from the human homologs which makes it a novel antimicrobial target. Several MRSA PK inhibitors (including the hydrazide 1) were identified using in silico screening combined with enzyme assays and were found to be selective for bacterial enzyme compared to human PK isoforms. Structure-activity relationship (SAR) studies were carried out on the replacement of the hydrazide linker with 3-atoms, 2-atoms and 0-atom linkers and led us to discover more potent compounds with enzyme inhibiting activities in the low nanomolar range and some were found to effectively inhibit bacteria growth in culture with minimum inhibitory concentrations (MIC) as low as 1 μg/mL. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  1. Quaternary ammonium biocides as antimicrobial agents protecting historical wood and brick.

    Science.gov (United States)

    Rajkowska, Katarzyna; Koziróg, Anna; Otlewska, Anna; Piotrowska, Małgorzata; Nowicka-Krawczyk, Paulina; Brycki, Bogumił; Kunicka-Styczyńska, Alina; Gutarowska, Beata

    2016-01-01

    Quaternary ammonium compounds (QACs) are widely used in disinfection of water, surfaces and instruments as well as in textile, leather and food industries because of their relatively low toxicity, broad antimicrobial spectrum, non-volatility and chemical stability. Due to these advantages, QACs are also used in restoration and can be applied on historical material. The aim of this study was to determine the usefulness of biocides based on quaternary ammonium salts and containing various excipients in the protection of historical materials against microbial growth. The study determined the antimicrobial activity of three biocides against bacteria: Pseudomonas fluorescens, Staphylococcus equorum, Bacillus cereus, Bacillus muralis, Sporosarcina aquimarina and Rhodococcus fascians, and moulds: Chaetomium globosum, Penicillium citreonigrum, Cladosporium cladosporioides I, Acremonium strictum, Aspergillus fumigatus and Cladosporium cladosporioides II, all isolated from historical wood and brick. Staphylococcus equorum, Bacillus cereus, Sporosarcina aquimarina and Rhodococcus fascians bacteria, and Cladosporium cladosporioides I and Acremonium strictum moulds showed high sensitivity to quaternary ammonium biocides. Historical wood can be effectively disinfected by three applications of biocide A (30% v/v) containing dodecyl dimethyl ammonium chloride (DDAC), citric acid, propiconazole and propanol. Disinfection of historical brick can be carried out by three applications of 6% v/v solutions of biocide B (based on DDAC and ethylenediaminetetraacetic acid - EDTA) or biocide C (containing a non-ionic surfactant, DDAC and EDTA). Effective protection of historical building materials against microbial growth for a period of seven days can be achieved by the application of biocide A (30% v/v) on the wood surface and biocide B (6% v/v) on the brick surface.

  2. Isolation, Purification and Characterization of Antimicrobial Agent Antagonistic to Escherichia coli ATCC 10536 Produced by Bacillus pumilus SAFR-032 Isolated from the Soil of Unaizah, Al Qassim Province of Saudi Arabia.

    Science.gov (United States)

    S Alanazi, Abdurrahman; Qureshi, Kamal Ahmad; Elhassan, Gamal Osman; I El-Agamy, Elsayed

    Escherichia coli is one of the most common pathogenic bacteria, which cause urinary tract infections in infants as well as in adult human beings. Due to the emergence of antibiotic resistance in E. coli, there is a great demand of new antimicrobial agent for the treatment of infections caused by such E. coli. This study aims to isolate, identify and characterize the native soil-bacterial strains predominate in the soil of Unaizah city, which produce antimicrobial agent antagonistic to E. coli ATCC 10536, followed by isolation, purification and characterization of antimicrobial agent. Pour plate, spread plate and 16S rRNA sequence analysis methods were followed for the isolation and identification of soil bacteria. Ammonium sulphate and dialysis (MWCO-8 KD) methods were followed for the isolation and partial purification of antimicrobial agent from the cell free broths. The characterization of antimicrobial agent was carried out by determining the minimum inhibitory concentration and effects of temperature and pH on the antimicrobial stability. Out of the twenty five soil samples, only one soil-bacterial strain was found to produce antimicrobial agent antagonistic to E. coli ATCC 10536. The isolated soil bacterium was identified as Bacillus pumilus SAFR-032. The soil isolate was characterized and results suggest that 30°C temperature and pH 7.0 were the optimum growth parameters and soybean casein digest broth was the best fermentation medium, whereas the highest production of antimicrobial agent was at 35°C temperature, pH 7.0, shaking at 150-220 rpm and at 60th h of incubation. The maximum yield of antimicrobial agent was obtained at 60% of (NH 4) 2SO 4. The results of characterization of antimicrobial agent suggest that the maximum and minimum antimicrobial activities were at pH 3.0 and 8.0, respectively, whereas antimicrobial activity was unaffected by temperature. The antimicrobial agent was highly stable at varying range of temperature 50-120°C. Minimum

  3. Optimization of four types of antimicrobial agents to increase the inhibitory ability of marine Arthrobacter oxydans KQ11 dextranase mouthwash

    Science.gov (United States)

    Ren, Wei; Wang, Shujun; Lü, Mingsheng; Wang, Xiaobei; Fang, Yaowei; Jiao, Yuliang; Hu, Jianen

    2016-03-01

    We adopted the response surface methodology using single factor and orthogonal experiments to optimize four types of antimicrobial agents that could inhibit biofilm formation by Streptococcus mutans, which is commonly found in the human oral cavity and causes tooth decay. The objective was to improve the function of marine Arthrobacter oxydans KQ11 dextranase mouthwash (designed and developed by our laboratory). The experiment was conducted in a three-level, four-variable central composite design to determine the best combination of ZnSO4, lysozyme, citric acid and chitosan. The optimized antibacterial agents were 2.16 g/L ZnSO4, 14 g/L lysozyme, 4.5 g/L citric acid and 5 g/L chitosan. The biofilm formation inhibition reached 84.49%. In addition, microscopic observation of the biofilm was performed using scanning electron microscopy and confocal laser scanning microscopy. The optimized formula was tested in marine dextranase Arthrobacter oxydans KQ11 mouthwash and enhanced the inhibition of S. mutans. This work may be promoted for the design and development of future marine dextranase oral care products.

  4. 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.

  5. Oregano essential oil-pectin edible films as anti-quorum sensing and food antimicrobial agents.

    Science.gov (United States)

    Alvarez, Maria V; Ortega-Ramirez, Luis A; Gutierrez-Pacheco, M Melissa; Bernal-Mercado, A Thalia; Rodriguez-Garcia, Isela; Gonzalez-Aguilar, Gustavo A; Ponce, Alejandra; Moreira, Maria Del R; Roura, Sara I; Ayala-Zavala, J Fernando

    2014-01-01

    Edible films can be used as carriers for antimicrobial compounds to assure food safety and quality; in addition, pathogenesis of food bacteria is related to a cell to cell communication mechanism called quorum sensing (QS). Oregano essential oil (OEO) has proved to be useful as food antimicrobial; however, its food applications can be compromised by the volatile character of its active constituents. Therefore, formulation of edible films containing OEO can be an alternative to improve its food usages. QS inhibitory activity of OEO and pectin-OEO films was evaluated using Chromobacterium violaceum as bacterial model. Additionally, antibacterial activity was tested against Escherichia coli O157:H7, Salmonella Choleraesuis, Staphylococcus aureus, and Listeria monocytogenes. OEO was effective to inhibit bacterial growth at MIC of 0.24 mg/mL for all tested bacteria and MBC of 0.24, 0.24, 0.48, and 0.24 mg/mL against E. coli O157:H7, S. Choleraesuis, S. aureus, and L. monocytogenes, respectively. Pectin-films incorporated with 36.1 and 25.9 mg/mL of OEO showed inhibition diameters of 16.3 and 15.2 mm for E. coli O157:H7; 18.1 and 24.2 mm for S. Choleraesuis; 20.8 and 20.3 mm for S. aureus; 21.3 and 19.3 mm for L. monocytogenes, respectively. Pectin-OEO film (15.7 mg/mL) was effective against E. coli O157:H7 (9.3 mm), S. aureus (9.7 mm), and L. monocytogenes (9.2 mm), but not for S. Choleraesuis. All concentrations of OEO (0.0156, 0.0312, 0.0625 and 0.125 mg/mL) and pectin-OEO films (15.7, 25.9 and 36.1 mg/mL) showed a significant anti-QS activity expressed as inhibition of violacein production by C. violaceum. Additionally, the application of pectin-OEO films was effective reducing total coliforms, yeast, and molds of shrimp and cucumber slices stored at 4°C during 15 d. These results demonstrated the potential of pectin films enriched with OEO as food related microorganisms and QS inhibitors.

  6. 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

  7. Oregano essential oil-pectin edible films as anti-quorum sensing and food antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Victoria eAlvarez

    2014-12-01

    Full Text Available Edible films can be used as carriers for antimicrobial compounds to assure food safety and quality; in addition, pathogenesis of food bacteria is related to a cell to cell communication mechanism called quorum sensing (QS. Oregano essential oil (OEO has proved to be useful as food antimicrobial; however, its food applications can be compromised by the volatile character of its active constituents. Therefore, formulation of edible films containing OEO can be an alternative to improve its food usages. QS inhibitory activity of OEO and pectin-OEO films was evaluated using Chromobacterium violaceum as bacterial model. Additionally, antibacterial activity was tested against Escherichia coli O157:H7, Salmonella Choleraesuis, Staphylococcus aureus, and Listeria monocytogenes. OEO was effective to inhibit bacterial growth at MIC of 0.24 mg/mL for all tested bacteria and MBC of 0.24, 0.24, 0.48, and 0.24 mg/mL against E. coli O157:H7, S. Choleraesuis, S. aureus, and L. monocytogenes, respectively. Pectin-films incorporated with 36.1 and 25.9 mg/mL of OEO showed inhibition diameters of 16.3 and 15.2 mm for E. coli O157:H7; 18.1 and 24.2 mm for S. Choleraesuis; 20.8 and 20.3 mm for S. aureus; 21.3 and 19.3 mm for L. monocytogenes, respectively. Pectin-OEO film (15.7 mg/mL was effective against E. coli O157:H7 (9.3 mm, S. aureus (9.7 mm, and L. monocytogenes (9.2 mm, but not for S. Choleraesuis. All concentrations of OEO (0.0156, 0.0312, 0.0625 and 0.125 mg/mL and pectin-OEO films (15.7, 25.9 and 36.1 mg/mL showed a significant anti-QS activity expressed as inhibition of violacein production by C. violaceum. Additionally, the application of pectin-OEO films was effective reducing total coliforms, yeast, and molds of shrimp and cucumber slices stored at 4 °C during 15 d. These results demonstrated the potential of pectin films enriched with OEO as food related microorganisms and QS inhibitors.

  8. Secondary metabolites inhibiting ABC transporters and reversing resistance of cancer cells and fungi to cytotoxic and antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Michael eWink

    2012-04-01

    Full Text Available Fungal, bacterial and cancer cells can develop resistance against antifungal, antibacterial or anticancer agents. Mechanisms of resistance are complex and often multifactorial. Mechanisms include: 1. Activation of ABC transporters, such as P-gp, which pump out lipophilic compounds that have entered a cell, 2. Activation of cytochrome p450 oxidases which can oxidise lipophilic agents to make them more hydrophilic and accessible for conjugation reaction with glucuronic acid, sulphate or amino acids, and 3. Activation of glutathione transferase, which can conjugate xenobiotics. This review summarises the evidence that secondary metabolites of plants, such as alkaloids, phenolics and terpenoids can interfere with ABC transporters in cancer cells, parasites, bacteria and fungi. Among the active natural products several lipophilic terpenoids ( monoterpenes, diterpenes, triterpenes (including saponins, steroids (including cardiac glycosides and tetraterpenes but also some alkaloids (isoquinoline, protoberberine, quinoline, indole, monoterpene indole, and steroidal alkaloids function probably as competitive inhibitors of P-gp, MRP1 and BCRP in cancer cells, or efflux pumps in bacteria (NorA and fungi. More polar phenolics (phenolic acids, flavonoids, catechins, chalcones, xanthones, stilbenes, anthocyanins, tannins, anthraquinones, and naphthoquinones directly inhibit proteins forming several hydrogen and ionic bonds and thus disturbing the 3D structure of the transporters. The natural products may be interesting in medicine or agriculture as they can enhance the activity of active chemotherapeutics or pesticides or even reverse MDR, at least partially, of adapted and resistant cells. If these secondary metabolites are applied in combination with a cytotoxic or antimicrobial agent, they may reverse resistance in a synergistic fashion.

  9. Synthesis of metallocomplexes of water soluble bisquinolinylporhyrins as potential antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Yu. V. Ishkov

    2017-12-01

    Full Text Available At present, extensive research is being carried out on the phenomenon of resistance of microbes to antibiotics, including the newest of them. Among the most promising drug candidates for treatment such superbugs is derivatives of 5,15-disubstituted water-soluble porphyrins developed and patented by Destiny Pharma, UK. Here, we continued of our investigation of quinolinylporphyrins and report about synthesis of 5,15-di(n-propyl-10,20-di(3-quinolinylporphyrine and its isomer - 5,10-di(n-propyl-15,20-di(3-quinolinylporphyrine and their complexes with Fe and Mn. The porphyrins was obtained by mixed aldehydes condensation of mixture quinoline-3-carbaldehyde and n-butyraldehyde with pyrrole in propionic acid with small amount propionic anhydride. Above mentioned porphyrins was separated and purified by column chromatography on silica gel and their Fe and Mn complexes was synthesized in refluxing DMF by treatment respectively FeCl3 and Mn(CH3CO22. Water-soluble form of the metalloporphyrines was obtained by quaternization of nitrogen atom of quinolinyl substituents by methyl-paratoluenesulfonate for further investigation their antimicrobial properties.

  10. 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.

  11. 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.

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

    Science.gov (United States)

    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.

  13. 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%.

  14. 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%.

  15. 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)

  16. 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.

  17. 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.

  18. Essential oil from black currant buds as chemotaxonomy marker and antimicrobial agent.

    Science.gov (United States)

    Ethorđević, Boban S; Pljevljakušić, Ðorđević S; Savikin, Katarina P; Stević, Tatjana R; Bigović, Dubravka J

    2014-08-01

    Dormant buds are recognized as valuable side product of the blackcurrant cultivation. Four blackcurrant varieties cultivated in Serbia, i.e., Ben Sarek, Ometa, Ben Lomond, and Ben Nevis, were evaluated for the content, chemical composition, and antimicrobial activity of their bud essential oils. The oil yields of buds harvested during two different growth periods ranged from 1.2-2.0%, and the variety Ometa had the highest yield among the tested varieties. GC-FID and GC/MS analysis of the oils allowed the identification of eight main components, i.e., α-pinene (1.6-5.4%), sabinene (1.9-38.4%), δ-car-3-ene (13.0-50.7%), β-phellandrene (2.9-18.0%), terpinolene (6.6-11.9%), terpinen-4-ol (0.9-6.6%), β-caryophyllene (3.8-10.4%), and α-humulene (0.2-4.1%). In addition, the similarity degree of the essential-oil compositions of buds harvested from the upper and lower parts of the shrubs was investigated by hierarchical clustering. All essential oils originating from the same genotype were grouped in the same cluster, indicating the reliability of essential oils as chemotaxonomic markers. For more detailed chemotaxonomic investigations, the three compounds with the greatest variance were chosen, i.e., sabinene, δ-car-3-ene, and β-phellandrene, which proved to be efficient for the variety distinction. Factor analysis showed that the essential-oil composition as chemotaxonomic marker in blackcurrants was more reliable for variety Ben Sarek than for variety Ben Nevis. Moreover, it was demonstrated that the essential oils had very strong inhibitory activity against all tested microorganisms. Fungi were more sensitive than bacteria; indeed their growth was completely inhibited at much lower concentrations. In comparison to commercial antibiotics, significantly lower concentrations of the oils were necessary for the complete inhibition of fungal growth. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

  19. Gold Nanoparticles: An Efficient Antimicrobial Agent against Enteric Bacterial Human Pathogen

    Directory of Open Access Journals (Sweden)

    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.

  20. A colorimetric broth microdilution method for assessment of Helicobacter pylori sensitivity to antimicrobial agents.

    Science.gov (United States)

    Knezevic, Petar; Aleksic Sabo, Verica; Simin, Natasa; Lesjak, Marija; Mimica-Dukic, Neda

    2018-04-15

    Helicobacter pylori is a major infective etiological agent of the upper gastrointestinal tract diseases. The bacterium exhibits resistance to various conventional antibiotics, being usually challenging for eradication. Since there is an urge to consider alternative therapeutic strategies, the aim of the study was to examine selected essential oils of plants belonging to families Cupressaceae (Juniperus communis) and Lamiaceae (Hyssopus officinalis, Salvia officinalis, Melissa officinalis, Lavandula angustifolia, Ocimum basilicum and Thymus serpyllum) against H. pylori, using an improved microdilution broth method. The oils were examined in concentration range from 0.03 to 4 μL/mL. The method comprises Brain-heart infusion broth supplemented with yeast extract, horse serum and IsoVitaleX. After 3 day incubation, an equal volume of double strengthen Christensen's urea was added into each well and incubated for additional 4 h. In wells with present H. pylori, the medium changed color from yellow to purple, allowing MIC determination even without a microtitre plate reader. The microtitre format method is convenient as it is less expensive, easier to perform and requires less amount of an anti-H. pylori agent. The improved method enhances specificity to H. pylori, as fast urease activity is almost an exclusive property of this bacterium. The application of the second step incubation with Christensen's urea decreases the possibility of false positive/negative results due to contaminant growth or commonly poor H. pylori growth. Among the examined oils, J. communis, H. officinalis and O. basilicum were not active with the highest applied concentrations, while the most active was T. serpyllum, with MIC 2.0-4.0 μL/mL. This is the first report on essential oils activity of T. serpyllum and H. officinalis against H. pylori. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. In Vitro Activity of Antimicrobial Agents against Isolates from Patients with Acute Tonsillopharyngitis in Dakar, Senegal

    Directory of Open Access Journals (Sweden)

    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

  2. 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%.

  3. Design, synthesis and 2D QSAR study of novel pyridine and quinolone hydrazone derivatives as potential antimicrobial and antitubercular agents.

    Science.gov (United States)

    Abdelrahman, Mohamed A; Salama, Ismail; Gomaa, Mohamed S; Elaasser, Mahmoud M; Abdel-Aziz, Marwa M; Soliman, Dalia H

    2017-09-29

    The increased development of highly resistant bacterial strains and tuberculosis, constitute a serious public health threat, highlighting the urgent need of novel antibacterial agents. In this work, two novel series of nicotinic acid hydrazone derivatives (6a-r) and quinolone hydrazide derivatives (12a-l) were synthesized and evaluated as antimicrobial and antitubercular agents. The synthesized compounds were evaluated in vitro for their antibacterial, antifungal and antimycobacterial activities. Compounds 6f and 6p bearing the 3,4,5- (OCH3)3 and 2,5-(OCH3)2 benzylidene motifs were the most potent and as antibacterial, antifungal (MIC: 0.49-1.95 μg/mL) and (MIC: 0.49-0.98 μg/mL) respectively and antimycobacterial activity (MIC = 0.76 and 0.39 μg/mL) respectively. Besides, several derivatives, 6e, 6h, 6l-6o, 6q, 6r, 12a, 12b, 12e, 12h, 12k and 12l, exhibited significant antibacterial and antifungal activities with MIC values ranging from 1.95 to 7.81 μg/mL, they also displayed excellent to good activity against Mycobacterium tuberculosis with MIC range from 0.39 to 3.12 μg/mL. In addition, some of the most active compounds were tested for cytotoxic activities against human lung fibroblast normal cells (WI-38) and displayed low toxicity. Moreover, 2D-QSAR models to characterize the descriptors controlling the observed activities, were generated and validated. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. The effect of colouring agent on the physical properties of glass ceramic produced from waste glass for antimicrobial coating deposition

    Science.gov (United States)

    Juoi, J. M.; Ayoob, N. F.; Rosli, Z. M.; Rosli, N. R.; Husain, K.

    2016-07-01

    Domestic waste glass is utilized as raw material for the production of glass ceramic material (GCM) via sinter crystallisation route. The glass ceramic material in a form of tiles is to be utilized for the deposition of Ag-TiO2 antimicrobial coating. Two types of soda lime glass (SLG) that are non-coloured and green SLG are utilised as main raw materials during the batch formulation in order to study the effect of colouring agent (Fe2O3) on the physical and mechanical properties of glass ceramic produced. Glass powder were prepared by crushing bottles using hammer milled with milling machine and sieved until they passed through 75 µm sieve. The process continues by mixing glass powder with ball clay with ratio of 95:5 wt. %, 90:10 wt. % and 85:15 wt. %. Each batch mixture was then uniaxial pressed and sintered at 800°C, 825 °C and 850 °C. The physical and mechanical properties were then determined and compared between those produced from non-coloured and green coloured SLG in order to evaluate the effect of colouring agent (Fe2O3) on the GCM produced. The optimum properties of non-coloured SLG is produced with smaller ball clay content (10 wt. %) compared to green SLG (15 wt. %). The physical properties (determined thru ASTM C373) of the optimized GCM produced from non-coloured SLG and green SLG are 0.69 % of porosity, 1.92 g/cm3 of bulk density, 0.36 % of water absorption; and 1.96 % of porosity, 2.69 g/cm3 of bulk density, 0.73 % of water absorption; respectively. Results also indicate that the most suitable temperature in producing GCM from both glasses with optimized physical and mechanical properties is at 850 °C.

  5. 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.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Saviuc, Crina; Ciubucă, Bianca; Dincă, Gabriela; Bleotu, Coralia; Drumea, Veronica; Chifiriuc, Mariana-Carmen; Popa, Marcela; Gradisteanu Pircalabioru, Gratiela; Marutescu, Luminita; Lazăr, Veronica

    2017-01-17

    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.

  9. 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......, whereas satA was not observed among any of the virginiamycin-resistant isolates from Finland. A total of 72% of the virginiamycin-resistant E. faecium from broilers in Denmark and all nine virginiamycin-resistant E. faeciuim from Finland contained satG. This gene was also observed among two (7......%) 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....

  10. DNA vaccines: technology and application as anti-parasite and anti-microbial agents.

    Science.gov (United States)

    Alarcon, J B; Waine, G W; McManus, D P

    1999-01-01

    DNA vaccines have been termed The Third Generation of Vaccines. The recent successful immunization of experimental animals against a range of infectious agents and several tumour models of disease with plasmid DNA testifies to the powerful nature of this revolutionary approach in vaccinology. Among numerous advantages, a major attraction of DNA vaccines over conventional vaccines is that they are able to induce protective cytotoxic T-cell responses as well as helper T-cell and humoral immunity. Here we review the current state of nucleic acid vaccines and cover a wide range of topics including delivery mechanisms, uptake and expression of plasmid DNA, and the types of immune responses generated. Further, we discuss safety issues, and document the use of nucleic acid vaccines against viral, bacterial and parasitic diseases, and cancer. The early potential promise of DNA vaccination has been fully substantiated with recent, exciting developments including the movement from testing DNA vaccines in laboratory models to non-human primates and initial human clinical trials. These advances and the emerging voluminous literature on DNA vaccines highlight the rapid progress that has been made in the DNA immunization field. It will be of considerable interest to see whether the progress and optimism currently prevailing can be maintained, and whether the approach can indeed fulfil the medical and commerical promise anticipated.

  11. The fatty acid synthase inhibitor triclosan: repurposing an anti-microbial agent for targeting prostate cancer.

    Science.gov (United States)

    Sadowski, Martin C; Pouwer, Rebecca H; Gunter, Jennifer H; Lubik, Amy A; Quinn, Ronald J; Nelson, Colleen C

    2014-10-15

    Inhibition of FASN has emerged as a promising therapeutic target in cancer, and numerous inhibitors have been investigated. However, severe pharmacological limitations have challenged their clinical testing. The synthetic FASN inhibitor triclosan, which was initially developed as a topical antibacterial agent, is merely affected by these pharmacological limitations. Yet, little is known about its mechanism in inhibiting the growth of cancer cells. Here we compared the cellular and molecular effects of triclosan in a panel of eight malignant and non-malignant prostate cell lines to the well-known FASN inhibitors C75 and orlistat, which target different partial catalytic activities of FASN. Triclosan displayed a superior cytotoxic profile with a several-fold lower IC50 than C75 or orlistat. Structure-function analysis revealed that alcohol functionality of the parent phenol is critical for inhibitory action. Rescue experiments confirmed that end product starvation was a major cause of cytotoxicity. Importantly, triclosan, C75 and orlistat induced distinct changes to morphology, cell cycle, lipid content and the expression of key enzymes of lipid metabolism, demonstrating that inhibition of different partial catalytic activities of FASN activates different metabolic pathways. These finding combined with its well-documented pharmacological safety profile make triclosan a promising drug candidate for the treatment of prostate cancer.

  12. 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

  13. 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

  14. Bacteriophage PBC1 and its endolysin as an antimicrobial agent against Bacillus cereus.

    Science.gov (United States)

    Kong, Minsuk; Ryu, Sangryeol

    2015-04-01

    Bacillus cereus is an opportunistic human pathogen responsible for food poisoning and other, nongastrointestinal infections. Due to the emergence of multidrug-resistant B. cereus strains, the demand for alternative therapeutic options is increasing. To address these problems, we isolated and characterized a Siphoviridae virulent phage, PBC1, and its lytic enzymes. PBC1 showed a very narrow host range, infecting only 1 of 22 B. cereus strains. Phylogenetic analysis based on the major capsid protein revealed that PBC1 is more closely related to the Bacillus clarkii phage BCJA1c and phages of lactic acid bacteria than to the phages infecting B. cereus. Whole-genome comparison showed that the late-gene region, including the terminase gene, structural genes, and holin gene of PBC1, is similar to that from B. cereus temperate phage 250, whereas their endolysins are different. Compared to the extreme host specificity of PBC1, its endolysin, LysPBC1, showed a much broader lytic spectrum, albeit limited to the genus Bacillus. The catalytic domain of LysPBC1 when expressed alone also showed Bacillus-specific lytic activity, which was lower against the B. cereus group but higher against the Bacillus subtilis group than the full-length protein. Taken together, these results suggest that the virulent phage PBC1 is a useful component of a phage cocktail to control B. cereus, even with its exceptionally narrow host range, as it can kill a strain of B. cereus that is not killed by other phages, and that LysPBC1 is an alternative biocontrol agent against B. cereus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Synthesis of silver nanoparticles using Dioscorea bulbifera tuber extract and evaluation of its synergistic potential in combination with antimicrobial agents

    Directory of Open Access Journals (Sweden)

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

    Science.gov (United States)

    Zúñiga, G. E.; Junqueira-Gonçalves, 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.

  17. 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.

  18. Qualitative screening of veterinary anti-microbial agents in tissues, milk, and eggs of food-producing animals using liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Chen, Dongmei; Yu, Jie; Tao, Yanfei; Pan, Yuanhu; Xie, Shuyu; Huang, Lingli; Peng, Dapeng; Wang, Xu; Wang, Yulian; Liu, Zhenli; Yuan, Zonghui

    2016-04-01

    A method for the analysis of 120 drugs in animal derived food was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). These analytes belong to 12 families of veterinary anti-microbial agents (quinolones, macrolides, β-lactams, nitroimidazoles, sulfonamides, lincomycines, chloramphenicols, quinoxalines, tetracyclines, polypeptides, and antibacterial synergists) as well as other compounds not assigned to a particular drug family. The animal derived food samples include muscle and liver of swine, bovine, sheep, and chicken, as well as hen eggs and dairy milk. The sample preparation included ultrasound-assisted extraction (UAE) with acetonitrile-water and a final clean-up with auto solid-phase extraction (SPE) on HLB cartridges. The detection and quantification of 120 anti-microbial agents was performed using LC-MS/MS in positive and negative ion mode. The chromatographic separation was performed on a C18 column using acetonitrile and 0.1% formic acid as the mobile phase. The limit of detection (LOD) and limit of quantification (LOQ) of all drugs in food-producing animals were 0.5-3.0μg/kg and 1.5-10.0μg/kg, respectively. The developed method was successfully utilized to monitor real samples, which demonstrated that it is a simple, fast, and robust method, and could be used as a regulatory to screen for the presence of residues from veterinary anti-microbial drugs in animal-derived foods. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Initial identification and sensitivity to antimicrobial agents of Salmonella sp.isolated from poultry products in the state of Ceara, Brazil

    Directory of Open Access Journals (Sweden)

    WF Oliveira

    2006-09-01

    Full Text Available The objective of this research was to isolate and to verify the sensitivity to antimicrobial agents of strains of Salmonella sp. isolated from poultry products in the state of Ceara, Brazil. A total number of 114 samples was collected from 63 broiler carcasses derived from two processing plants and two supermarkets, and 51 excreta samples were collected in broiler farms located in the state of Ceara, which used three live production stages. Each excreta sample consisted of a fresh excreta pool from 100 birds. Samples were submitted to microbiological analyses, and the isolated Salmonella strains were tested for antimicrobial sensitivity. No Salmonella was isolated from excreta samples, while broiler carcass samples showed a high contamination rate of11.8%. Three serotypes were identified: Salmonella enterica serovar Enteritidis, 50%; Salmonella enterica serovar Panama 33%, and Salmonella enterica serovar Newport, 17%. As to the susceptibility tests to antimicrobial agents, 100% of the isolated Salmonella strains showed resistance to Ampicillin and Tetracycline, and sensitivity to Gentamycin, Netilmycin, Carbenicillin, Chloramphenicol.

  20. 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.

  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. The role of spices and lactic acid bacteria as antimicrobial agent to extend the shelf life of metata ayib (traditional Ethiopian spiced fermented cottage cheese).

    Science.gov (United States)

    Geremew, Tsehayneh; Kebede, Ameha; Andualem, Berhanu

    2015-09-01

    Spices and lactic acid bacteria have natural antimicrobial substances and organic compounds having antagonistic activity against microorganisms. The objective of this study was to investigate the role of spices and lactic acid bacteria as antimicrobial agent to extend the shelf life of metata ayib. Antimicrobial activities of spices and lactic acid bacteria (LAB) filtrates were determined by agar well diffusion method against E. coli, S. aureus, S. flexneri and S. peumoniae. Aantimicrobial activity of garlic was found to be the most effective against all the tested pathogens. Inhibition zones of garlic extract against all pathogens was significantly (P ≤ 0.05) greater than the remaining spice extracts. Inhibition zones (12.50 ± 1.00 to 15.50 ± 1.00 mm) of ginger and R. graveolens ethanol extracts against all tested pathogens were significantly (P ≤ 0.05) greater than the remaining solvent extracts. Inhibition zone of O. basilicum ethanol extract against all pathogenic bacteria was significantly (p ≤ 0.05) greater than hexane and acetone extracts. Lactobacillus isolates were shown the highest antimicrobial activity than the other LAB isolates against all pathogens. The synergistic effect of spices together with LAB might be contributed a lot to preserve and extend shelf life of metata ayib. Their antimicrobial activity can reduce the risk of spoilage and pathogenesis. The possible reason of LAB isolates was may be due to production of lactic acid, acetic acid and secondary metabolites like bacteriocins. Aseptic processing of traditional cottage cheese (ayib) is by far needed to minimize risks associated during consumption of metata ayib.

  3. Synthesis and evaluation of (Z)-2,3-diphenylacrylonitrile analogs as anti-cancer and anti-microbial agents.

    Science.gov (United States)

    Alam, Mohammad Sayed; Nam, Young-Joo; Lee, Dong-Ung

    2013-11-01

    In the present study, a series of (Z)-2,3-diphenylacrylonitrile analogs were synthesized and then evaluated in terms of their cytotoxic activities against four human cancer cell lines, e.g. lung cancer (A549), ovarian cancer (SK-OV-3), skin cancer (SK-MEL-2), and colon cancer (HCT15), as well as anti-microbial activities against three microbes, e.g. Staphylococcus aureus, Salmonella typhi, and Aspergillus niger. The title compounds were synthesized by Knoevenagel condensation reaction of benzyl cyanide or p-nitrobenzyl cyanide with substituted benzaldehydes in good yields. Most of the compounds exhibited significant suppressive activities against the growth of all cancer cell lines. Compound 3c was most active in inhibiting the growth of A549, SK-OV-3, SK-MEL-2, and HCT15 cells lines with IC50 values of 0.57, 0.14, 0.65, and 0.34 mg/mL, respectively, followed by compounds 3f, 3i, and 3h. Compound 3c exhibited 2.4 times greater cytotoxic activity against HCT15 cells, whereas it showed similar potency against SK-OV-3 cells to that of the standard anti-cancer agent doxorubicin. Structure-activity relationship study revealed that electron-donating groups at the para-position of phenyl ring B were more favorable for improved cytotoxic activity, whereas the presence of electron-withdrawing groups was unfavorable compare to unsubstituted acrylonitrile. An optimal electron density on phenyl ring A of (Z)-2,3-diphenylacrylonitrile analogs was crucial for their cytotoxic activities against human cancer cell lines used in the present study. Qualitative structure-cytotoxic activity relationships were studied using physicochemical parameters; a good correlation between calculated polar surface area (PSA), a lipophobic parameter, and cytotoxic activity was found. Moreover, all compounds showed significant anti-bacterial activities against S. typhi, whereas compound 3k showed potent inhibition against both S. aureus and S. typhi bacterial strains. Copyright © 2013 Elsevier

  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

    . 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. PMID:22334779

  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

    2011-01-01

    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

  6. 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.

  7. Establishing the Minimal Bactericidal Concentration of an Antimicrobial Agent for Planktonic Cells (MBC-P) and Biofilm Cells (MBC-B)

    OpenAIRE

    Mah, Thien-Fah

    2014-01-01

    This protocol allows for a direct comparison between planktonic and biofilm resistance for a bacterial strain that can form a biofilm in vitro. Bacteria are inoculated into the wells of a 96-well microtiter plate. In the case of the planktonic assay, serial dilutions of the antimicrobial agent of choice are added to the bacterial suspensions. In the biofilm assay, once inoculated, the bacteria are left to form a biofilm over a set period of time. Unattached cells are removed from the wells, t...

  8. 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.

  9. Repositioning antimicrobial agent pentamidine as a disruptor of the lateral interactions of transmembrane domain 5 of EBV latent membrane protein 1.

    Directory of Open Access Journals (Sweden)

    Xiaohui Wang

    Full Text Available The lateral transmembrane protein-protein interactions (PPI have been regarded as "undruggable" despite their importance in many essential biological processes. The homo-trimerization of transmembrane domain 5 (TMD-5 of latent membrane protein 1 (LMP-1 is critical for the constitutive oncogenic activation of the Epstein-Barr virus (EBV. Herein we repurpose the antimicrobial agent pentamidine as a regulator of LMP-1 TMD-5 lateral interactions. The results of ToxR assay, tryptophan fluorescence assay, courmarin fluorescence dequenching assay, and Bis-Tris sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE consistently show pentamidine disrupts LMP-1 TMD-5 lateral interactions. Furthermore, pentamidine inhibits LMP-1 signaling, inducing cellular apoptosis and suppressing cell proliferation in the EBV infected B cells. In contrast, EBV negative cells are less susceptible to pentamidine. This study provides a novel non-peptide small molecule agent for regulating LMP-1 TMD-5 lateral interactions.

  10. Evaluation of minimum inhibitory and minimum bactericidal concentration of nano-silver base inorganic anti-microbial agent (Novaron(®)) against streptococcus mutans.

    Science.gov (United States)

    Holla, Goda; Yeluri, Ramakrishna; Munshi, Autar Krishen

    2012-07-01

    We attempted to find the possibility of determining the minimum inhibitory concentration and minimum bactericidal concentration needed for nano-silver base inorganic anti-microbial agent (Novaron(®) AG 300, AG 1100) against Streptococcus mutans in vitro using broth dilution assay. An ampoule of freeze-dried S. mutans NCTC reference strain was revived, and the colony-forming units (CFU) were calculated. The MIC and MBC was determined by broth dilution assay using different concentrations of Novaron(®) AG 300 and Novaron(®) AG 1100 against 1 × 10(5) CFU/ml of S. mutans. The MIC and MBC of Novaron(®) AG 300 and Novaron(®) AG 1100 against S. mutans were found to be 40 μg/ml. Novaron(®) has anti-bacterial effect against S. mutans. Further studies are needed to explore the applicability of these silver-supported anti- microbial agents in clinical dentistry.

  11. Cathelicidin-BF, a snake cathelicidin-derived antimicrobial peptide, could be an excellent therapeutic agent for acne vulgaris.

    Directory of Open Access Journals (Sweden)

    Yipeng Wang

    Full Text Available Cathelicidins are a family of antimicrobial peptides acting as multifunctional effector molecules in innate immunity. Cathelicidin-BF has been purified from the snake venoms of Bungarus fasciatus and it is the first identified cathelicidin antimicrobial peptide in reptiles. In this study, cathelicidin-BF was found exerting strong antibacterial activities against Propionibacterium acnes. Its minimal inhibitory concentration against two strains of P. acnes was 4.7 µg/ml. Cathelicidin-BF also effectively killed other microorganisms including Staphylococcus epidermidis, which was possible pathogen for acne vulgaris. Cathelicidin-BF significantly inhibited pro-inflammatory factors secretion in human monocytic cells and P. acnes-induced O2.- production of human HaCaT keratinocyte cells. Observed by scanning electron microscopy, the surfaces of the treated pathogens underwent obvious morphological changes compared with the untreated controls, suggesting that this antimicrobial peptide exerts its action by disrupting membranes of microorganisms. The efficacy of cathelicidin-BF gel topical administering was evaluated in experimental mice skin colonization model. In vivo anti-inflammatory effects of cathelicidin-BF were confirmed by relieving P. acnes-induced mice ear swelling and granulomatous inflammation. The anti-inflammatory effects combined with potent antimicrobial activities and O2.- production inhibition activities of cathelicidin-BF indicate its potential as a novel therapeutic option for acne vulgaris.

  12. 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.

  13. Design and synthesis of Quinazolinone, Benzothiazole derivatives bearing guanidinopropanoic acid moiety and their Schiff bases as cytotoxic and antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Palani Venkatesh

    2016-09-01

    Full Text Available Two series of Benzothiazole, Quinazolinone derivatives bearing guanidinopropanoic acid (38 compounds including 27 intermediates and one series of Schiff base derivatives (14 compounds were synthesized, characterized then evaluated for their cytotoxicity against human cervix cell line (HeLa by MTT assay; antimicrobial activity against 11 pathogenic bacteria, 10 pathogenic fungus using standard of ciprofloxacin and Clotrimazole respectively. Compounds 13–18 showed significant activity against HeLa with IC50 range of 2–550 μM. Compound 3-(3-(6-hydroxybenzo[d]thiazol-2-ylguanidinopropanoic acid (18 showed potent activity against human HeLa cell line with the half maximal inhibitory concentration (IC50 values of 1.8 μM which was close to the value of the positive control, doxorubicin. Antimicrobial result indicated that, compounds showed differential activity against the tested fungus and bacteria. Compounds 11, 14, 38 and 49 exhibited potent antibacterial and antifungal activity.

  14. 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.

  15. In Vitro Synergistic Activity of Antimicrobial Agents in Combination against Clinical Isolates of Colistin-Resistant Acinetobacter baumannii

    OpenAIRE

    Bae, Seongman; Kim, Min-Chul; Park, Su-Jin; Kim, Hee Sueng; Sung, Heungsup; Kim, Mi-Na; Kim, Sung-Han; Lee, Sang-Oh; Choi, Sang-Ho; Woo, Jun Hee; Kim, Yang Soo; Chong, Yong Pil

    2016-01-01

    Emerging resistance to colistin in clinical Acinetobacter baumannii isolates is of growing concern. Since current treatment options for these strains are extremely limited, we investigated the in vitro activities of various antimicrobial combinations against colistin-resistant A. baumannii. Nine clinical isolates (8 from bacteremia cases and 1 from a pneumonia case) of colistin-resistant A. baumannii were collected in Asan Medical Center, Seoul, South Korea, between January 2010 and December ...

  16. Synthesis of 2-azetidinones from 2-diazo-1, 2-diarylethanones and N-(2-thienylidene)imines as possible antimicrobial agents.

    Science.gov (United States)

    Singh, Girija S; Mmolotsi, Boycie J

    2005-09-01

    An equimolar reaction of 2-diazo-1, 2-diarylethanones with N-(2-thienylidene)imines affords 1-substituted-3, 3-diaryl-4-(2-thienyl)-2-azetidinones in excellent yields. The products have been characterized on the basis of satisfactory analytical and spectral (IR, 1H and 13C NMR, MS) data. The mechanism of formation of the products is shown. The antimicrobial activity of the compounds against some Gram(+) and Gram(-) bacteria, and fungi is reported.

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

    Science.gov (United States)

    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.

  18. Binary and Tertiary Mixtures of Satureja hortensis and Origanum vulgare Essential Oils as Potent Antimicrobial Agents Against Helicobacter pylori.

    Science.gov (United States)

    Lesjak, Marija; Simin, Natasa; Orcic, Dejan; Franciskovic, Marina; Knezevic, Petar; Beara, Ivana; Aleksic, Verica; Svircev, Emilija; Buzas, Krisztina; Mimica-Dukic, Neda

    2016-03-01

    Essential oils possess strong antimicrobial activity, even against multiresistant Helicobacter pylori. Available therapies against H. pylori infection have multiple disadvantages, indicating a great need for a development of new therapeutics. The purpose of this study was to develop a potent natural product based anti-H. pylori formulation. First, anti-H. pylori activity of nine essential oils was determined, after which the most active oils were mixed in various ratios for further testing. Satureja hortensis, Origanum vulgare subsp. vulgare and O. vulgare subsp. hirtum essential oils expressed the highest activity (MIC = 2 μL mL(-1)). Their binary and ternary mixtures exhibited notably higher antimicrobial activity (MIC ≤ 2 μL mL(-1)). The most active was the mixture of S. hortensis and O. vulgare subsp. hirtum oils in volume ratio 2:1, which expressed 4 times higher activity than individual oils (MIC = 0.5 μL mL(-1)). According to GC-MS, both oils in the mixture were characterized by high content of phenols (48-73%), with carvacrol as the main carrier of antimicrobial activity. Presented in vitro study pointed out binary mixture of S. hortensis and O. vulgare subsp. hirtum essential oils in volume ratio 2:1 as promising candidate for further in vivo studies targeting H. pylori infection. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Design, synthesis and docking studies of new furobenzopyranones and pyranobenzopyranones as photoreagent towards DNA and as antimicrobial agents.

    Science.gov (United States)

    Farag, Nahla A H; El-Tayeb, Wafaa

    2010-01-01

    A number of new furobenzopyranones and pyranobenzopyranones carrying an electron-withdrawing function at the position 3 are synthesized in order to obtain new photoreagents towards DNA. Our interest in this study is to investigate the effect of introduction of electron withdrawing function on the position 3 of the benzo-á-pyranone ring of linear furobenzo-á-pyranone (5,8-dimethoxypsoralen) or angular pyranobenzo-á-pyranone on the biological activity, by preparing 3-cyano, carboxylic acid, carboxylic acid ester, acid hydrazide, thiosemicarbazide, or mercaptotriazole derivatives. 5-acetyl-6-hydroxybenzofuran, and 8-acetyl-7-hydroxy-4-phenylbenzopyranone are the key starting compounds on which 3-cyano-4-methylfurobenzopyranone and 3-cyano-4-methyl pyranobenzopyranone moieties were built respectively. The photobiological activity of the newly synthesized compounds was evaluated. It looks most promising for enhancement of photoreactivity of compounds towards DNA, and a certain effect was observed in the dark determining the antimicrobial activity. Compounds 5, 6, 7, 13, 14 exhibit potential photoreactivity towards DNA, while 3-mercaptotriazole derivatives 7, 14 possess only photosensitizing activity. To investigate the antimicrobial data on structural basis, molecular modelling and docking studies of the tested compounds into the crystal structure of topoisomerase II DNA Gyrase B complexed with the natural inhibitor bearing the coumarin moiety clorobiocin (1kzn), using Molsoft ICM 3.4-8C program was performed in order to predict the affinity and orientation of the synthesized compounds at the active site. The ICM score values and hydrogen bonds formed with the surrounding amino acids show good agreement with predicted binding affinities obtained by molecular docking studies as verified by antimicrobial screening, where compounds 5, 6, 13 were the most active compounds against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. Compound 13 has good

  20. Therapeutic drug monitoring of antimicrobials.

    Science.gov (United States)

    Balakrishnan, Indran; Shorten, Robert J

    2016-05-01

    As pathology services become more centralized and automated, the measurement of therapeutic antimicrobial drugs concentrations is increasingly performed in clinical biochemistry or 'blood science' laboratories. This review outlines key groups of antimicrobial agents: aminoglycosides, glycopeptides, antifungal agents and antituberculosis agents, their role in managing infectious diseases, and the reasons why serum concentration measurement is important. © The Author(s) 2016.

  1. The fractional inhibitory concentration index of antimicrobial agents for bacteria and Mycoplasma isolated from the nasal swabs of cattle with respiratory diseases.

    Science.gov (United States)

    Katoh, T; Sakai, J; Itagaki, M; Watanabe, E; Watanabe, D; Ogata, Y

    1996-08-01

    We investigated the effect of thiamphenicol plus lincomycin (TP + LCM) and thiamphenicol plus tylosin (TP + TS) combinations using checker board method on the growth of Pasteurella (P.) multocida, P. haemolytica and Mycoplasma (M.) bovis by calculating the fractional inhibitory concentration index (FIC index). The results showed that the FIC indexes of the TP + LCM combination for P. multocida, P. haemolytica and M. bovis were 0.36 +/- 0.10, 0.72 +/- 0.09 and 0.81 +/- 0.18, respectively. The FIC indexes of the TP + TS combination for P. multocida, P. haemolytica, and M. bovis were 0.79 +/- 0.20, 0.66 +/- 0.11 and 0.32 +/- 0.14, respectively. Thus, these combinations are assumed to have a more synergistic or additive effect on bacteria growth than a single antimicrobial agent.

  2. Resistance to antimicrobial agents of Vibrio cholerae El Tor strains isolated during the fourth cholera epidemic in the United Republic of Tanzania

    Science.gov (United States)

    Towner, K. J.; Pearson, N. J.; Mhalu, F. S.; O'Grady, F.

    1980-01-01

    Isolates of Vibrio cholerae obtained immediately after the outbreak of the fourth recorded epidemic of cholera in the United Republic of Tanzania were sensitive to tetracycline, but after five months of its extensive therapeutic and prophylactic use, 76% of the isolates were observed to be resistant to this and other antimicrobial agents. The appearance of resistance was found to be due to the rapid spread of antibiotic resistance plasmids belonging to the C incompatibility complex. Although most plasmid incompatibility groups have been shown to be unstable in V. cholerae, the strains found in the present epidemic seem to carry a plasmid belonging to one of the few relatively stable groups. These findings emphasize the importance of monitoring any emergence of bacterial resistance that may occur when mass prophylaxis programmes are in operation and also the importance of determining the genetic basis of the resistance mechanism. PMID:6975183

  3. Effectiveness of the antimicrobial removal device, BACTEC 16B medium, and thiol broth in neutralizing antibacterial activities of imipenem, norfloxacin, and related agents.

    Science.gov (United States)

    Weinberg, E; Shungu, D L; Gadebusch, H H

    1984-02-01

    The Antimicrobial Removal Device (ARD), BACTEC 16B medium, and Thiol broth were evaluated for their effectiveness in reducing the activity of imipenem (IPM), cefoxitin, moxalactam, and ceftazidime in blood samples. In addition, the capability of the ARD and Thiol broth to bind norfloxacin and the ARD to bind oxolinic and nalidixic acids in urine samples was investigated. At the highest concentrations of the drugs tested (32 micrograms/ml for the four beta-lactams and 256 micrograms/ml for the three quinolinecarboxylic acids), there was at least a 95% reduction in the in vitro activity of each of the antibacterial agents for treated versus untreated samples. Of the compounds tested in the ARD system, the organic acids were more completely removed than were the beta-lactams. The Thiol broth was more effective than the ARD and the BACTEC 16B medium in inactivating imipenem, but it had no effect on the antibacterial activity of norfloxacin.

  4. In Vitro Evaluation of the Remineralizing Potential and Antimicrobial Activity of a Cariostatic Agent with Silver Nanoparticles

    OpenAIRE

    Scarpelli, Beatriz Brandão; Punhagui, Marília Franco; Hoeppner, Márcio Grama; Almeida, Ricardo Sergio Couto de; Juliani, Felipe Augusto; Guiraldo, Ricardo Danil; Berger, Sandrine Bittencourt

    2017-01-01

    Abstract Cariostatic treatment has been shown to successfully arrest caries. However, it blackens the carious tooth structure. This study evaluated the effects of an experimental cariostatic agent with silver nanoparticles (Ag-Nano) using microhardness (MH) and microbiological tests. The cariostatic agents tested were: Saforide®, Cariestop®, Ancarie® and Ag-Nano. Sixty-six samples from deciduous enamel were submitted to initial (after pH cycling to obtain initial caries-like lesion) and final...

  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. First report on rapid screening of nanomaterial-based antimicrobial agents against β-lactamase resistance using pGLO plasmid transformed Escherichia coli HB 101 K-12

    Science.gov (United States)

    Raj, M. Alpha; Muralidhar, Y.; Sravanthi, M.; Prasad, T. N. V. K. V.; Nissipriya, M.; Reddy, P. Sirisha; Neelima, T. Shoba; Reddy, G. Dilip; Adilaxmamma, K.; Kumar, P. Anand; Krishna, T. Giridhara

    2016-08-01

    Combating antibiotic resistance requires discovery of novel antimicrobials effective against resistant bacteria. Herein, we present for the first time, pGLO plasmid transformed Escherichia coli HB 101 K 12 as novel model for screening of nanomaterial-based antimicrobial agents against β-lactamase resistance. E. coli HB 101 was transformed by pGLO plasmid in the presence of calcium chloride (50 mM; pH 6.1) aided by heat shock (0-42-0 °C). The transformed bacteria were grown on Luria-Bertani agar containing ampicillin (amp) and arabinose (ara). The transformed culture was able to grow in the presence of ampicillin and also exhibited fluorescence under UV light. Both untransformed and transformed bacteria were used for screening citrate-mediated nanosilver (CNS), aloin-mediated nanosilver (ANS), 11-α-keto-boswellic acid (AKBA)-mediated nanosilver (BNS); nanozinc oxide, nanomanganese oxide (NMO) and phytochemicals such as aloin and AKBA. Minimum inhibitory concentrations (MIC) were obtained by microplate method using ρ-iodo nitro tetrazolium indicator. All the compounds were effective against transformed bacteria except NMO and AKBA. Transformed bacteria exhibited reverse cross resistance against aloin. ANS showed the highest antibacterial activity with a MIC of 0.32 ppm followed by BNS (10.32 ppm), CNS (20.64 ppm) and NZO (34.83 ppm). Thus, pGLO plasmid can be used to induce resistance against β-lactam antibiotics and the model can be used for rapid screening of new antibacterial agents effective against resistant bacteria.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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 

  12. Synthesis, spectroscopic and molecular docking studies of imidazolium and pyridinium based ionic liquids with HSA as potential antimicrobial agents

    Science.gov (United States)

    Trush, Maria M.; Semenyuta, Ivan V.; Vdovenko, Sergey I.; Rogalsky, Sergiy P.; Lobko, Evgeniya O.; Metelytsia, Larisa O.

    2017-06-01

    The interaction between human serum albumin (HSA) and synthesized imidazolium and pyridinium based ionic liquids (ILs), as good potential microbial growth inhibitors, was investigated by spectroscopic techniques combined with molecular docking analysis. All compounds were significant active against the tested bacterial and fungal strains. FT-IR spectroscopy indicated that the interaction of HSA with ILs generates considerable changes in protein secondary structure. The results of the molecular docking study showed that the studied ILs are able to firmly bind in the subdomain IIA of HSA with almost equal binding affinity (about -6.23 kcal/mol). Investigated HSA-ILs complex binds through hydrogen bonding or/and cation-π interactions. This study provides a better understanding of the binding of imidazolium and pyridinium based ILs to HSA and opens the way for their further biological and pharmaceutical investigations as candidates with antimicrobial properties.

  13. Synthesis of 1-(4-methoxybenzyl)-3-cyclopropyl-1H-pyrazol-5-amine derivatives as antimicrobial agents.

    Science.gov (United States)

    Raju, H; Nagamani, T S; Chandrappa, S; Ananda, H; Vinaya, K; Thimmegowda, N R; Byregowda, S M; Rangappa, K S

    2010-08-01

    A series of novel substituted 1-(4-methoxybenzyl)-3-cyclopropyl-1H-pyrazol-5-amine benzamides 9(a-h) were synthesized to determine their antibacterial and antifungal activities as well as possible structure-activity relationships (SARs) to improve therapeutic efficacy. The pyrazol-5-amine benzamides were screened for their antibacterial activity against standard strains of Gram-positive (Streptococcus pyogenes NCIM 2608, Staphylococcus aureus ATCC 29737, Bacillus subtilis NCIM 2010) and Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 20852, Klebsiella pneumoniae MTCC 618) bacteria by using streptomycin as positive control. They were also tested for their antifungal activities against mycotoxic strains of Fusarium verticillioides, Aspergillus ochraceous, Aspergillus flavus, Alternaria alternata, and Penicillium chrysogenum using nystatin as positive control. Among the synthesized compounds, 9d, 9g, and 9h showed potent antimicrobial activities.

  14. Cytochrome bd Protects Bacteria against Oxidative and Nitrosative Stress: A Potential Target for Next-Generation Antimicrobial Agents.

    Science.gov (United States)

    Borisov, V B; Forte, E; Siletsky, S A; Arese, M; Davletshin, A I; Sarti, P; Giuffrè, A

    2015-05-01

    Cytochrome bd is a terminal quinol oxidase of the bacterial respiratory chain. This tri-heme integral membrane protein generates a proton motive force at lower efficiency than heme-copper oxidases. This notwithstanding, under unfavorable growth conditions bacteria often use cytochrome bd in place of heme-copper enzymes as the main terminal oxidase. This is the case for several pathogenic and opportunistic bacteria during host colonization. This review summarizes recent data on the contribution of cytochrome bd to bacterial resistance to hydrogen peroxide, nitric oxide, and peroxynitrite, harmful species produced by the host as part of the immune response to microbial infections. Growing evidence supports the hypothesis that bd-type oxidases contribute to bacterial virulence by promoting microbial survival under oxidative and nitrosative stress conditions. For these reasons, cytochrome bd represents a protein target for the development of next-generation antimicrobials.

  15. 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

  16. Efficient Synthesis and Biological Evaluation of a Novel Series of 1,5-Benzodiazepine Derivatives as Potential Antimicrobial Agents.

    Science.gov (United States)

    An, Ying-Shuang; Hao, Zhen-Fang; Zhang, Xiu-Jun; Wang, Lan-Zhi

    2016-07-01

    A series of novel 1,5-benzodiazepine derivatives were rationally designed and synthesized following the principle of the superposition of bioactive substructures by the combination of 1,5-benzodiazepine, pyridine (phenyl), and an ester group. The structures of the target compounds were determined by (1) H NMR, (13) C NMR, MS, IR, and elemental analysis. All the synthesized compounds were evaluated for their antimicrobial activities in vitro against the fungi C. neoformans, C. neoformans clinical isolates (ATCC 32264), C. albicans (ATCC 10231), Gram-negative bacterium E. coli (ATCC 44752), and Gram-positive bacterium S. aureus (ATCC 25923). The results of the bioactive assay demonstrated that most of the tested compounds exhibited variable inhibitory effects on the growth of the tested microorganisms. All the active compounds showed better antifungal activity than antibacterial activity. Notably, compound 2b displayed the highest activity (MIC = 30 μg/mL) against C. neoformans and (MIC = 31 μg/mL) against C. neoformans clinical isolates. In addition, compound 2a also showed excellent activity against C. neoformans and C. neoformans clinical isolates with minimum inhibitory concentration of 35 and 36 μg/mL, respectively. Compounds 2a and 2b were further studied by evaluating their cytotoxicities, and the results showed that they have relatively low level cytotoxicity for BV2 and 293T cell. Preliminary structure-activity relationship study on three diverse sets (C-2, C-3, and C-8 positions) of 1,5-benzodiazepines was performed. The results revealed that the presence of a -CH3 group at the C-8 position had a positive effect on the inhibitory activity of these compounds. Additionally, the 2-pyridyl group at the C-2 position may be a pharmacophore and -COOC2 H5 at C-3 position is the best substituent for the maintenance of antimicrobial activities. © 2016 John Wiley & Sons A/S.

  17. [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.

  18. Evaluation of minimum inhibitory and minimum bactericidal concentration of nano-silver base inorganic anti-microbial agent (Novaron® against streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Goda Holla

    2012-01-01

    Full Text Available Objective: We attempted to find the possibility of determining the minimum inhibitory concentration and minimum bactericidal concentration needed for nano-silver base inorganic anti-microbial agent (Novaron® AG 300, AG 1100 against Streptococcus mutans in vitro using broth dilution assay. Materials and Methods: An ampoule of freeze-dried S. mutans NCTC reference strain was revived, and the colony-forming units (CFU were calculated. The MIC and MBC was determined by broth dilution assay using different concentrations of Novaron® AG 300 and Novaron® AG 1100 against 1 x 10 5 CFU/ml of S. mutans. Results: The MIC and MBC of Novaron® AG 300 and Novaron® AG 1100 against S. mutans were found to be 40 μg/ml. Conclusions: Novaron® has anti-bacterial effect against S. mutans. Further studies are needed to explore the applicability of these silver-supported anti- microbial agents in clinical dentistry.

  19. Evaluation of minimum inhibitory and minimum bactericidal concentration of nano-silver base inorganic anti-microbial agent (Novaron®) against streptococcus mutans

    Science.gov (United States)

    Holla, Goda; Yeluri, Ramakrishna; Munshi, Autar Krishen

    2012-01-01

    Objective: We attempted to find the possibility of determining the minimum inhibitory concentration and minimum bactericidal concentration needed for nano-silver base inorganic anti-microbial agent (Novaron® AG 300, AG 1100) against Streptococcus mutans in vitro using broth dilution assay. Materials and Methods: An ampoule of freeze-dried S. mutans NCTC reference strain was revived, and the colony-forming units (CFU) were calculated. The MIC and MBC was determined by broth dilution assay using different concentrations of Novaron® AG 300 and Novaron® AG 1100 against 1 × 105 CFU/ml of S. mutans. Results: The MIC and MBC of Novaron® AG 300 and Novaron® AG 1100 against S. mutans were found to be 40 μg/ml. Conclusions: Novaron® has anti-bacterial effect against S. mutans. Further studies are needed to explore the applicability of these silver-supported anti- microbial agents in clinical dentistry. PMID:23293483

  20. 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

  1. 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.

  2. Hydrazones of 2-aryl-quinoline-4-carboxylic acid hydrazides: synthesis and preliminary evaluation as antimicrobial agents.

    Science.gov (United States)

    Metwally, Kamel A; Abdel-Aziz, Lobna M; Lashine, El-Sayed M; Husseiny, Mohamed I; Badawy, Rania H

    2006-12-15

    A new series of 2-arylquinoline-4-carboxylic acid hydrazide-hydrazones was synthesized using an appropriate synthetic route. All the target compounds were evaluated for their in vitro antimicrobial activity against Staphylococcus aureus as an example for Gram-positive bacteria, Escherichia coli as an example for Gram-negative bacteria, and Candida albicans as a representative of fungi. The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standards. Among the compounds tested, compounds having nitro substituents at the arylidene moiety showed the most potent antifungal as well as antibacterial activities against E. coli. Compound 23 displayed an antifungal activity comparable to that of nystatin. However, none of the compounds demonstrated any antibacterial activity against S. aureus. Hydrophobicity of the target compounds correlated weakly with their antibacterial and antifungal activities. The most potent compounds namely, 7, 18, 19, 22, and 23 were assessed for hemolytic toxicity and found to be non-hemolytic up to a concentration of 100mug/mL. In addition, the most potent compound (23) was evaluated for in vitro cytotoxic activity against various cancer cell lines. This compound was found to display no cytotoxic activity but rather it induces the proliferation rate of Hep-G2 cells.

  3. Novel Ethyl 1,5-Disubstituted-1H-Pyrazole-3-Carboxylates as a New Class of Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Radwan Awwad A.

    2014-09-01

    Full Text Available A series of pyrazole derivatives 9-22 were designed and synthesized. All the newly synthesized compounds were assayed for their antimicrobial activity against the Grampositive bacteria Staphyllococcus aureus and Bacillius subtilis and the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, in addition to the fungi organisms, Candida albicans, C. parapsilosis and C. tropicalis. Ethyl 5-(2,5-dimethylthiophen- 3-yl-1-phenyl-1H-pyrazole-3-carboxylate (21 (MICE.coli = 0.038 μmol mL-1, MICP. aerug. = 0.067 μmol mL-1 is nearly as active as ampicillin (MIC = 0.033 and 0.067 μmol mL-1, respectively. Ethyl 5-(4-bromo-2-chlorophenyl- 1-phenyl-1H-pyrazole-3-carboxylate (16 (MIC = 0.015 μmol mL-1 is more active than fluconazole (0.020 μmol mL-1 as a reference drug against C. parapsilosis.

  4. 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.

  5. Efficacy of cinnamon bark oil and cinnamaldehyde on anti-multidrug resistant Pseudomonas aeruginosa and the synergistic effects in combination with other antimicrobial agents.

    Science.gov (United States)

    Utchariyakiat, Itsaraporn; Surassmo, Suvimol; Jaturanpinyo, Montree; Khuntayaporn, Piyatip; Chomnawang, Mullika Traidej

    2016-06-01

    The emergence of drug resistant pathogens becomes a crucial problem for infectious diseases worldwide. Among these bacteria, Pseudomonas aeruginosa is one of which highly resists to many currently used drugs and becomes a major concern in public health. Up till now, the search for potential antimicrobial agents has been still a challenge for researchers. Broth microdilution assay was used to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the essential oils and antibiotics against P. aeruginosa. Inhibition activity of the essential oils under vapor condition was examined to obtain the minimum inhibitory dose (MID). Time-kill assay included in this study was performed according to CLSI guideline. Bioautographic assay was used to detect active components of the essential oil. Synergistic effect with currently used antibiotics was further examined by checkerboard assay. In this study, a variety of essential oils were examined for anti-multidrug resistant P. aeruginosa (MDR-PA) activity, of which cinnamon bark oil showed the strongest antimicrobial activity against all clinical-isolated MDR-PA strains with MIC of 0.0562-0.225 % v/v and MBC of 0.1125-1.8 % v/v. Bioautographic results demonstrated that the active compounds of cinnamon bark oil were cinnamaldehyde and eugenol which showed strong inhibitory effect against P. aeruginosa. Interestingly, cinnamaldehyde, a major constituent of cinnamon bark oil, possessed stronger antimicrobial effect to P. aeruginosa than eugenol. Under gaseous condition, cinnamon bark oil and cinnamaldehyde showed antibacterial activity against MDR-PA strains with MID of 0.5-1 mg/L. Moreover, combination of cinnamon bark oil or cinnamaldehyde with currently used antibiotics was further studied by checkerboard assay to examine synergistic interactions on clinically isolated MDR-PA strains. Cinnamon bark oil and cinnamaldehyde combined with colistin demonstrated synergistic rates at 16

  6. Synthesis and antimicrobial evaluation of two peptide LyeTx I derivatives modified with the chelating agent HYNIC for radiolabeling with technetium-{sup 99m}

    Energy Technology Data Exchange (ETDEWEB)

    Fuscaldi, Leonardo Lima; Santos, Daniel Moreira dos; Pinheiro, Natalia Gabriela Silva; Araujo, Raquel Silva; Barros, Andre Luis Branco de; Resende, Jarbas Magalhaes; Fernandes, Simone Odilia Antunes; Lima, Maria Elena de; Cardoso, Valbert Nascimento, E-mail: valbertncardoso@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Analises Clinicas Toxicologica

    2016-11-01

    Background: 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 {sup 99m}Tc. Methods: 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 {sub 99m}Tc was performed in the presence of co-ligands (tricine and EDDA) and reducing agent (SnCl{sub 2} . 2H{sub 2}O), 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 < 0.05). Results: Both LyeTx I derivatives were suitably synthesized and purified, as shown by RP-HPLC and MALDI-ToF-MS analysis. The microbiological test showed that HYNIC-LyeTx I (N-terminal modification) did not inhibit bacterial growth, whereas LyeTx I-K-HYNIC (C-terminal modification) showed a MIC of 5.05 μmol. L−1 (S. aureus) and 10.10 μmol. L−1 (E. coli

  7. Antimicrobials in beekeeping.

    Science.gov (United States)

    Reybroeck, Wim; Daeseleire, Els; De Brabander, Hubert F; Herman, Lieve

    2012-07-06

    The bee diseases American and European foulbrood and nosemosis can be treated with anti-infectious agents. However, in the EU and the USA the use of these agents in beekeeping is strictly regulated due to the lack of tolerance (e.g. Maximum Residue Limit) for residues of antibiotics and chemotherapeutics in honey. This article reviews the literature dealing with antimicrobials of interest in apiculture, stability of these antimicrobials in honey, and disposition of the antimicrobials in honeybee hives. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Ali Adem Bahar

    2013-11-01

    Full Text Available The rapid increase in drug-resistant infections has presented a serious challenge to antimicrobial therapies. The failure of the most potent antibiotics to kill “superbugs” emphasizes the urgent need to develop other control agents. Here we review the history and new development of antimicrobial peptides (AMPs, a growing class of natural and synthetic peptides with a wide spectrum of targets including viruses, bacteria, fungi, and parasites. We summarize the major types of AMPs, their modes of action, and the common mechanisms of AMP resistance. In addition, we discuss the principles for designing effective AMPs and the potential of using AMPs to control biofilms (multicellular structures of bacteria embedded in extracellular matrixes and persister cells (dormant phenotypic variants of bacterial cells that are highly tolerant to antibiotics.

  9. The importance of expressing antimicrobial agents on water basis in growth/no growth interface models: a case study for Zygosaccharomyces bailii.

    Science.gov (United States)

    Dang, T D T; Vermeulen, A; Mertens, L; Geeraerd, A H; Van Impe, J F; Devlieghere, F

    2011-01-31

    In a previous study on Zygosaccharomyces bailii, three growth/no growth models have been developed, predicting growth probability of the yeast at different conditions typical for acidified foods (Dang, T.D.T., Mertens, L., Vermeulen, A., Geeraerd, A.H., Van Impe, J.F., Debevere, J., Devlieghere, F., 2010. Modeling the growth/no growth boundary of Z. bailii in acidic conditions: A contribution to the alternative method to preserve foods without using chemical preservatives. International Journal of Food Microbiology 137, 1-12). In these broth-based models, the variables were pH, water activity and acetic acid, with acetic acid concentration expressed in volume % on the total culture medium (i.e., broth). To continue the previous study, validation experiments were performed for 15 selected combinations of intrinsic factors to assess the performance of the model at 22°C (60days) in a real food product (ketchup). Although the majority of experimental results were consistent, some remarkable deviations between prediction and validation were observed, e.g., Z. bailii growth occurred in conditions where almost no growth had been predicted. A thorough investigation revealed that the difference between two ways of expressing acetic acid concentration (i.e., on broth basis and on water basis) is rather significant, particularly for media containing high amounts of dry matter. Consequently, the use of broth-based concentrations in the models was not appropriate. Three models with acetic acid concentration expressed on water basis were established and it was observed that predictions by these models well matched the validation results; therefore a "systematic error" in broth-based models was recognized. In practice, quantities of antimicrobial agents are often calculated based on the water content of food products. Hence, to assure reliable predictions and facilitate the application of models (developed from lab media with high dry matter contents), it is important to express

  10. Efficacy of Neem Extract and Three Antimicrobial Agents Incorporated into Tissue Conditioner in Inhibiting the Growth of C. Albicans and S. Mutans.

    Science.gov (United States)

    Barua, Dikshita Ray; Basavanna, Jayaprakash Mugur; Varghese, Rana Kalappattil

    2017-05-01

    Denture stomatitis is an inflammatory condition which compromises the mucosal surface beneath dentures. The aetiology of denture stomatitis is usually multifactorial which varies from trauma from ill fitting denture to poor immune system. There are evidences that denture stomatitis is an outcome of multispecies biofilms that include Candida albicans and Streptococcus mutans . Tissue conditioners are found to be more susceptible to colonisation by micro-organisms. The purpose of this study was to compare the efficacy of neem leaf extract and three other antimicrobial agents incorporated in a tissue conditioner against both Candida albicans and Streptococcus mutans . Standard strain of Candida albicans and Streptococcus mutans were inoculated into Sabouraud Dextrose broth and Mitis-Salivarius-Bacitracin broth respectively incubated at 37°C. Tissue conditioner (Viscogel) mixed with two different concentrations of ketoconazole, nystatin and chlorhexidine diacetate (5%, 10% w/w) and neem leaf extract (7.5% w/w and 15% w/w) and control group (plain tissue conditioner) were placed into punch hole (6 mm diameter) agar plate inoculated with Candida albicans and Streptococcus mutans . A total of 216 samples were prepared for both Candida albicans and Streptococcus mutans . Mean Inhibition Diameter (MID) across each punch holes were measured in millimetres at 24 hours and seven days and data were statistically analysed using Kruskal Wallis test followed by Mann-Whitney U test. Both ketoconazole and nystatin (10% w/w) showed maximum inhibition of 32 mm and mean of 31.75 followed by 15% w/w neem leaf extract with an inhibition of 21 mm and mean of 20.67 after 24 hours against Candida albicans whereas chlorhexidine diacetate (10% w/w) showed mean of 25.67 followed by chlorhexidine diacetate (5% w/w) and neem extract (15% w/w) which showed mean of 24.17 and 23.67 respectively against Streptococcus mutans . Neem leaf extract exhibited considerable potential to be an efficacious

  11. Absorbent silver (I) antimicrobial fabrics

    Science.gov (United States)

    In recent years, silver in form of silver ions, has been gaining importance in the wound management as an effective broad-spectrum antimicrobial agent. Silver has a long history as an antimicrobial agent, especially in the treatment of wounds. Alginates and carboxymethyl (CM) cotton contain carboxyl...

  12. Identification of natural antimicrobial agents to treat dengue infection: In vitro analysis of latarcin peptide activity against dengue virus.

    Science.gov (United States)

    Rothan, Hussin A; Bahrani, Hirbod; Rahman, Noorsaadah Abd; Yusof, Rohana

    2014-05-31

    Although there have been considerable advances in the study of dengue virus, no vaccines or anti-dengue drugs are currently available for humans. Therefore, new approaches are necessary for the development of potent anti-dengue drugs. Natural antimicrobial peptides (AMPs) with potent antiviral activities are potential hits-to-leads for antiviral drug discovery. We performed this study to identify and characterise the inhibitory potential of the latarcin peptide (Ltc 1, SMWSGMWRRKLKKLRNALKKKLKGE) against dengue virus replication in infected cells. The Ltc 1 peptide showed a significantly inhibitory effect against the dengue protease NS2B-NS3pro at 37°C, a physiological human temperature, (IC50, 12.68 ± 3.2 μM), and greater inhibitory effect was observed at 40°C, a temperature similar to a high fever (IC50, 6.58 ± 4.1 μM). A greater reduction in viral load (p.f.u./ml) was observed at simultaneous (0.7 ± 0.3 vs. 7.2 ± 0.5 control) and post-treatment (1.8 ± 0.7 vs. 6.8 ± 0.6 control) compared to the pre-treatment (4.5 ± 0.6 vs. 6.9 ± 0.5 control). Treatment with the Ltc 1 peptide reduced the viral RNA in a dose-dependent manner with EC50 values of 8.3 ± 1.2, 7.6 ± 2.7 and 6.8 ± 2.5 μM at 24, 48 and 72 h, respectively. The Ltc 1 peptide exhibited significant inhibitory effects against dengue NS2B-NS3pro and virus replication in the infected cells. Therefore, further investigation is necessary to develop the Ltc 1 peptide as a new anti-dengue therapeutic.

  13. Zinc-Substituted Myoglobin Is a Naturally Occurring Photo-antimicrobial Agent with Potential Applications in Food Decontamination.

    Science.gov (United States)

    Delcanale, Pietro; Montali, Chiara; Rodríguez-Amigo, Beatriz; Abbruzzetti, Stefania; Bruno, Stefano; Bianchini, Paolo; Diaspro, Alberto; Agut, Montserrat; Nonell, Santi; Viappiani, Cristiano

    2016-11-16

    Zinc-substituted myoglobin (ZnMb) is a naturally occurring photosensitizer that generates singlet oxygen with a high quantum yield. Using a combination of photophysical and fluorescence imaging techniques, we demonstrate the interaction of ZnMb with Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. An efficient antibacterial action against S. aureus was observed, with a reduction up to 99.9999% in the number of colony-forming units, whereas no sizable effect was detected against E. coli. Because ZnMb is known to form during the maturation of additive-free not-cooked cured ham, the use of this protein as a built-in photodynamic agent may constitute a viable method for the decontamination of these food products from Gram-positive bacteria.

  14. In Vitro Activity of Antimicrobial Agents Against Streptococcus Pyogenes Isolates from patients with Acute Tonsillopharyngitis in Dakar, Senegal

    Directory of Open Access Journals (Sweden)

    A. Gueye Ndiaye

    2009-06-01

    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 MIC90 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 tonsillopharyngitis.

  15. Evaluation of the synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp strains

    Directory of Open Access Journals (Sweden)

    Lívia Viganor da Silva

    2011-02-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA and coagulase-negative Staphylococcus spp (CNS are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT, VAN plus rifampin (RIF and VAN plus imipenem (IPM in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.

  16. Aerosol-based efficient delivery of telithromycin, a ketolide antimicrobial agent, to lung epithelial lining fluid and alveolar macrophages for treatment of respiratory infections.

    Science.gov (United States)

    Togami, Kohei; Chono, Sumio; Seki, Toshinobu; Morimoto, Kazuhiro

    2010-07-01

    The efficacy of aerosol-based delivery of telithromycin (TEL), as a model antimicrobial agent, for the treatment of respiratory infections was evaluated by comparison with oral administration. The aerosol formulation (0.2 mg/kg) was administered to rat lungs using a Liquid MicroSprayer. The time courses of the concentration of TEL in lung epithelial lining fluid (ELF) and alveolar macrophages (AMs) following administration of an aerosol formulation to rat lungs were markedly higher than that following the administration of an oral formulation (50 mg/kg). The time course of the concentrations of TEL in plasma following administration of the aerosol formulation was markedly lower than that in ELF and AMs. These results indicate that the aerosol formulation is more effective in delivering TEL to ELF and AMs, compared to the oral formulation, despite a low dose and it avoids distribution of TEL to the blood. In addition, the antibacterial effects of TEL in ELF and AMs following administration of the aerosol formulation were estimated by pharmacokinetics/pharmacodynamics analysis. The concentrations of TEL in ELF and the AMs time curve/minimum inhibitory concentration of TEL ratio were markedly higher than the effective values. This study indicates that an antibiotic aerosol formulation may be an effective pulmonary drug delivery system for the treatment of respiratory infections.

  17. Ziziphora clinopodioides Essential Oil and Nisin as Potential Antimicrobial Agents against Escherichia coli O157:H7 in Doogh (Iranian Yoghurt Drink

    Directory of Open Access Journals (Sweden)

    Yasser Shahbazi

    2015-01-01

    Full Text Available The aim of the present study was to evaluate the effects of Ziziphora clinopodioides essential oil (0.1 and 0.2% and nisin (250 and 500 IU/mL separately and in combination on survival of Escherichia coli O157:H7 inoculated in Doogh (Iranian yoghurt drink during storage under refrigerated temperature (4 ± 1°C for 9 days. Viability of Lactobacillus casei at different concentrations of Z. clinopodioides essential oil (0.1 and 0.2% in Doogh was also examined. The major components were carvacrol (64.22%, thymol (19.22%, γ-terpinene (4.63%, and p-cymene (4.86%. There was no significant difference (p>0.05 between samples treated with nisin and those of untreated samples. Samples treated with both concentrations of the essential oil (0.1 and 0.2% showed populations of E. coli O157:H7 significantly (p<0.05 lower than those of untreated samples. The essential oil of Z. clinopodioides in combination with nisin had a potential synergistic effect against E. coli O157:H7 in Doogh samples after 5 days. The count of L. casei was not inhibited by different concentrations of the Z. clinopodioides essential oil. It is concluded that the leaf essential oil of Z. clinopodioides in combination with nisin can be applied as alternative antimicrobial agents in Doogh to inhibit the growth of E. coli O157:H7.

  18. A DFT Study of Some Structural and Spectral Properties of 4-Methoxyacetophenone Thiosemicarbazone and Its Complexes with Some Transition Metal Chlorides: Potent Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Julius Numbonui Ghogomu

    2016-01-01

    Full Text Available Recent studies have shown that 4-methoxyacetophenone thiosemicarbazone (MAPTSC and its complexes with some transition metal chlorides are potent antimicrobial agents. To deepen the understanding of their structure-activity relationships necessary for rational drug design, their structural and spectral properties, along with thione-thiol tautomerism of MAPTSC, have been studied herein using the density functional theory (DFT. From our results, the thione tautomer of MAPTSC is more stable than the thiol counterpart in ethanolic solution, and thione-to-thiol tautomerization is highly precluded at ambient temperature (25°C by a high barrier height ≈46.41 kcal/mol. MAPTSC can therefore exist as a mixture of the thione (major and thiol (minor tautomers in ethanolic solution at room and higher temperatures. Conformational analysis has revealed five possible conformers of the thione tautomer, of which two are stable enough to be isolated at 25°C. Based on our computed values of MAPTSC-metal(II binding energies, enthalpies, and Gibbs free energies, the thione tautomer of MAPTSC exhibits a higher affinity for the d8 metal ions Ni(II, Pd(II, and Pt(II and can therefore efficiently chelate them in chemical and biological systems. Natural population analysis has revealed ligand-metal charge transfer in the MAPTSC complexes studied. A good agreement has been found between calculated and experimentally observed spectral properties (IR, UV-Vis, and NMR.

  19. 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

    , Salmonella choleraesuis, Salmonella typhimurium, Streptococcus suis, Streptococcus dysgalactiae subsp. equisimilis, Streptococcus equi subsp. equi, and Streptococcus equi subsp. zooepidemicus. In addition to ceftiofur, the following antimicrobial agents or combinations were tested: enroflaxacin, ampicillin.......0, greater than or equal to 256.0, greater than or equal to 32.0, and greater than or equal to 16.0 mu g/ml, respectively. Trimethoprim-sulfadiazine was active against isolates of A. pleuropneumoniae, S. choleraesuis, S. typhimurium, P. multocida, S. equi, and S. suis (MIC(90)s, less than or equal to 0.5 mu...... g/ml) but was less active against the E. coli strains tested (MIG(90), >16.0 mu g/ml). Ampicillin was active against the P. multocida, S. suis, and S. equi isolates tested (MIC(90)s, 0.5, 0.06, and 0.06 mu g/ml, respectively) and was moderately active against S. typhimurium (MIC(90)s, 2.0 mu g...

  20. Danish integrated antimicrobial in resistance monitoring and research program

    DEFF Research Database (Denmark)

    Hammerum, Anette Marie; Heuer, Ole Eske; Emborg, Hanne-Dorthe

    2007-01-01

    a systematic and continuous monitoring program of antimicrobial drug consumption and antimicrobial agent resistance in animals, food, and humans, the Danish Integrated Antimicrobial Resistance Monitoring and Research Program (DANMAP). Monitoring of antimicrobial drug resistance and a range of research......Resistance to antimicrobial agents is an emerging problem worldwide. Awareness of the undesirable consequences of its widespread occurrence has led to the initiation of antimicrobial agent resistance monitoring programs in several countries. In 1995, Denmark was the first country to establish...... activities related to DANMAP have contributed to restrictions or bans of use of several antimicrobial agents in food animals in Denmark and other European Union countries....

  1. Synthesis of potent inhibitor/span>s of β-ketoacyl-acyl carrier protein synthase III as potential antimicrobial agents.

    Science.gov (United States)

    Liu, Yan; Zhong, Wu; Li, Rui-Juan; Li, Song

    2012-04-25

    Mycobacterium tuberculosis FabH, an essential enzyme in the mycolic acid biosynthetic pathway, is an attractive target for novel anti-tubercolosis agents. Structure-based design and synthesis of 1-(4-carboxybutyl)-4-(4-(substituted benzyloxy)phenyl)-1H-pyrrole-2-carboxylic acid derivatives 7a-h, a subset of eight potential FabH inhibitors, is described in this paper. The Vilsmeier-Haack reaction was employed as a key step. The structures of all the newly synthesized compounds were identified by IR, ¹H-NMR, ¹³C-NMR, ESI-MS and HRMS. The alamarBlue™ microassay was employed to evaluate the compounds 7a-h against Mycobacterium tuberculosis H₃₇Rv. The results demonstrate that the compound 7d possesses good in vitro antimycobacterial activity against Mycobacterium tuberculosis H₃₇Rv (Minimum Inhibitory Concentration value [MIC], 12.5 µg/mL).These compounds may prove useful in the discovery and development of new anti-tuberculosis drugs.

  2. Isolation and Discovery of New Antimicrobial-agent Producer Strains Using Antibacterial Screening of Halophilic Gram-positive Endospore-forming Bacteria Isolated from Saline Lakes of Iran

    OpenAIRE

    Asefeh Dahmardeh Ghalehno; Maryam Ghavidel-Aliabadi; Zeinab Shahmohamadi; Maliheh Mehrshad; Mohammad Ali Amoozegar; Abolghasem Danesh

    2018-01-01

    Abstract Background: Today, discovery and production of new antimicrobial drugs has been emphasized due to the growing of antimicrobial resistance. The purpose of this study was to screen out antimicrobial producing bacteria among halophilic or halotolerant Gram-positive endospore-forming bacteria isolated from different areas of Iran. Materials and Methods: 62 strains were isolated from salin lakes of Iran, endospore-forming ability was evaluated and further identification of strains ...

  3. Efficacy of Calendula officinalis Extract (Marigold Flower as an Antimicrobial Agent against Oral Microbes: An Invitro Study in Comparison with Chlorhexidine Digluconate

    Directory of Open Access Journals (Sweden)

    Shrinidhi Maji Shankar

    2017-10-01

    Full Text Available Introduction: Calendula officinalis is a member of the family Asteraceae containing flavonoids, and essential oils etc. It is known to be effective against certain gram negative and gram positive clinical pathogens. Incorporating natural plant extracts into periodontal antiinfective therapy is a wise alternative in light of rampant antibiotic resistance amongst periodontal pathogens. Aim: To assess the antimicrobial efficacy of C.officinalis against five oral microbes, as compared to gold standard chlorhexidine digluconate. Materials and Methods: The inhibitory action of the two test agents, chlorhexidine digluconate 0.2% and C.officinalis raw extract was assessed using tests to determine minimum inhibitory concentration, minimum bactericidal concentration, and inhibition zones using agar diffusion method. Time kill curve method was used to assess the time in which drug was inhibitive against five oral microbes namely, A.actinomycetemcomitans, P.gingivalis, P.intermedia, F.nucelatum and S.mutans. Results: P.gingivalis and P.intermedia were sensitive to C.officinalis, while F.nucleatum and A.actinomycetemcomitans exhibited reduced sensitivity. C.officinalis was highly effective against S.mutans (3.12 µg/mL, its inhibitory concentration close to that of chlorhexidine digluconate 0.2% (6.25 µg/mL. C.officinalis took longer than chlorhexidine digluconate 0.2% to exhibit lethality against all the organisms that it inhibited. Chlorhexidine exhibited immediate lethality (zero minute against S.mutans while it inhibited the other microbes at 5 minutes. A.actinomycetemcomitans and P.intermedia were inhibited by C.officinalis at 30 minutes, S.mutans at 10 minutes. F.nucleatum was inhibited by C.officinalis at 2 hours and no inhibition of P.gingivalis by C.officinalis was observed. Conclusion: C.officinalis showed antimicrobial efficacy against most organisms tested, yet its efficacy was not on par with chlorhexidine digluconate 0.2%. However, its

  4. Clinical evaluation of antimicrobial peptide [{sup 99m}Tc/Tricine/HYNIC{sup 0}]ubiquicidin 29-41 as a human-specific infection imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Gandomkar, Mostafa [Nuclear Science Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, Tehran, 11365-3486 (Iran, Islamic Republic of)], E-mail: msgandomkar@yahoo.com; Najafi, Reza; Shafiei, Mohammad; Mazidi, Mohammad; Goudarzi, Mostafa; Mirfallah, Seyed Hassan [Nuclear Science Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, Tehran, 11365-3486 (Iran, Islamic Republic of); Ebrahimi, Farhad; Heydarpor, Hamid Reza; Abdie, Noroz [Noor Institute of Nuclear Medicine, Tehran (Iran, Islamic Republic of)

    2009-02-15

    Introduction: Ubiquicidin (UBI) 29-41 is a cationic synthetic antimicrobial peptide fragment that binds preferentially with the anionic microbial cell membrane at the site of infection. This study was conducted to evaluate the potentiality of [{sup 99m}Tc/Tricine/HYNIC{sup 0}]UBI 29-41 prepared from lyophilized kits as an infection imaging agent in humans. Methods: Seven patients (5 males and 2 females; mean age=55 years; age range=35-75 years) with suspected bone or soft-tissue infections participated in this study. [{sup 99m}Tc/Tricine/HYNIC]UBI 29-41, corresponding to activity in the range 555-740 MBq added to 40 {mu}g of peptide obtained from instant freeze-dried kit formulations with radiochemical purities >95%, was injected intravenously. A 45-min dynamic study was followed by spot views of the suspected region of infection (target) and a corresponding normal area (nontarget). Whole-body anterior and posterior images were also acquired at 30, 60 and 120 min after injection. True- or false-positive or true- or false-negative images were interpreted upon bacterial culture, radiography, clinical tests and bone scanning. Results: The biodistribution of [{sup 99m}Tc/Tricine/HYNIC]UBI 29-41 in patients showed rapid accumulation of activity in the kidneys in the first 30 min after injection that gradually declined and accumulated in the urinary bladder. There were positive findings in five studies and negative findings in two. Findings were subsequently confirmed to be true positive or negative. Images showed minimal accumulation in nontarget tissues, with an average target/nontarget ratio of 2.10{+-}0.33 in positive lesions at 30 min. Conclusion: Given its favorable clinical characteristics, [{sup 99m}Tc/Tricine/HYNIC]UBI 29-41 shows promise as a tracer for infection imaging that allows early diagnosis (30 min) of infection.

  5. Aerosol-based efficient delivery of clarithromycin, a macrolide antimicrobial agent, to lung epithelial lining fluid and alveolar macrophages for treatment of respiratory infections.

    Science.gov (United States)

    Togami, Kohei; Chono, Sumio; Morimoto, Kazuhiro

    2012-04-01

    Macrolide antimicrobial agents are generally given by the oral route for the treatment of respiratory infections caused by pathogenic microorganisms infected in lung epithelial lining fluid (ELF) and alveolar macrophages (AMs). However, because macrolides distribute to many different tissues via the blood after oral administration, systemic side effects are frequently induced. In contrast with oral administration, aerosolization may be an efficient method for delivering macrolides directly to ELF and AMs. In this study, the efficacy of aerosol-based delivery of clarithromycin (CAM), as a model macrolide, for the treatment of respiratory infections was evaluated by comparison with oral administration. The aerosol formulation of CAM (0.2 mg/kg) was administered to rat lungs using a Liquid MicroSprayer(®). The oral formulation of CAM (50 mg/kg) was used for comparison. Time courses of concentrations of CAM in ELF and AMs following administration were obtained, and then the bioavailability (BA) was calculated. In addition, the area under the concentrations of CAM in ELF and AMs-time curve/minimum inhibitory concentration at which 90% of isolates ratio [area under the curve (AUC/MIC(90))] were calculated to estimate the antibacterial effects in ELF and AMs. The BA of CAM in ELF and AMs following administration of aerosol formulation were markedly greater than that following administration of oral formulation. This indicates that the aerosol formulation is more effective in delivering CAM to ELF and AMs, compared with the oral formulation, despite a low dose. The AUC/MIC(90) of CAM in ELF and AMs were markedly higher than the effective values. This indicates that the aerosol formulation could be useful for the treatment of respiratory infections caused by pathogenic microorganisms infected in ELF and AMs. This study suggests that aerosol formulation of macrolides is an effective pulmonary drug delivery system for the treatment of respiratory infections.

  6. Electrophoretic large volume sample stacking for sensitive determination of the anti-microbial agent pentamidine in rat plasma for pharmacological studies.

    Science.gov (United States)

    Tůma, Petr; Heneberg, Petr; Vaculín, Šimon; Koval, Dušan

    2018-01-02

    A sensitive capillary electrophoretic method with on-line sample preconcentration by large volume sample stacking has been developed for determination of the anti-microbial agent pentamidine. The separation is performed in a fused silica capillary coated with covalently bound hydroxypropyl cellulose, with an internal diameter of 50 μm and length of 31.5 cm; the background electrolyte was 100 mM acetic acid/Tris at pH 4.7. The stacking is tested using a model sample of 1 μM pentamidine dissolved in 25% infusion solution and 75% acidified acetonitrile. Stacking permits the injection of a sample zone with a length of 95% of the total capillary length to achieve an enhancing factor of 77 compared to low injection into 1.8% of the total capillary length, with simultaneous high separation efficiency of approximately 1 350 000 plates/m. Stacking is based on simultaneous application of a separation field and a hydrodynamic pressure to force the acetonitrile zone out of the capillary. This approach allows the determination of pentamidine in rat blood plasma using only 12.5 μL of plasma treated by the addition of acetonitrile in a ratio of 1:3 v/v. The attained LOD is 0.03 μM and the intra-day repeatability is 0.1% for the migration time and 1.0% for the peak area at the injection 28.3% of capillary length. The performed pharmacokinetic study with ten-second scanning of the blood reveals rapid dynamics of pentamidine in the arterial bloodstream, while the changes are much slower in the venous system. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. β-Lactamase Production in Prevotella intermedia, Prevotella nigrescens, and Prevotella pallens Genotypes and In Vitro Susceptibilities to Selected Antimicrobial Agents

    Science.gov (United States)

    Mättö, Jaana; Asikainen, Sirkka; Väisänen, Marja-Liisa; Von Troil-Lindén, Birgitta; Könönen, Eija; Saarela, Maria; Salminen, Kari; Finegold, Sydney M.; Jousimies-Somer, Hannele

    1999-01-01

    The present study investigated the β-lactamase production of 73 Prevotella intermedia, 84 Prevotella nigrescens, and 14 Prevotella pallens isolates and their in vitro susceptibilities to six antimicrobial agents. The P. intermedia and P. nigrescens isolates were recovered from oral and extraoral samples obtained from subjects in two geographic locations from 1985 to 1995. The clonality of the β-lactamase-positive and β-lactamase-negative isolates and the clustering of the genotypes were studied by arbitrarily primed-PCR fingerprinting. β-Lactamase production was detected in 29% of P. intermedia isolates, 29% of P. nigrescens isolates, and 57% of P. pallens isolates. No difference in the frequencies of β-lactamase production by P. intermedia and P. nigrescens between isolates from oral and extraoral sites, between isolates obtained at different time periods, or between P. intermedia isolates from different geographic locations was observed. However, the P. nigrescens isolates from the United States were significantly more frequently (P = 0.015) β-lactamase positive than those from Finland. No association between the genotypes and β-lactamase production or between the genotypes and the sources of the isolates was found. The penicillin G MICs at which 90% of the isolates were inhibited were 8 μg/ml for P. intermedia, 8 μg/ml for P. nigrescens, and 16 μg/ml for P. pallens. For the β-lactamase-negative isolates, the corresponding values were 0.031, 0.031, and 0.125 μg/ml, and for the β-lactamase-positive isolates, the corresponding values were 16, 8, and 32 μg/ml. All isolates were susceptible to amoxicillin-clavulanate, cefoxitin, metronidazole, azithromycin, and trovafloxacin. The MICs of amoxicillin-clavulanate and cefoxitin were relatively higher for the β-lactamase-positive population than for the β-lactamase-negative population. PMID:10508011

  8. Antimicrobial Tolerance in Biofilms

    OpenAIRE

    Stewart, Philip S.

    2015-01-01

    The tolerance of microorganisms in biofilms to antimicrobial agents is examined through a meta-analysis of literature data. A numerical tolerance factor comparing the rates of killing in the planktonic and biofilm states is defined to provide a quantitative basis for the analysis. Tolerance factors for biocides and antibiotics range over three orders of magnitude. This variation is not explained by taking into account the molecular weight of the agent, the chemistry of the agent, the substrat...

  9. Alternative Antimicrobial Approach: Nano-Antimicrobial Materials

    Directory of Open Access Journals (Sweden)

    Nurit Beyth

    2015-01-01

    Full Text Available Despite numerous existing potent antibiotics and other antimicrobial means, bacterial infections are still a major cause of morbidity and mortality. Moreover, the need to develop additional bactericidal means has significantly increased due to the growing concern regarding multidrug-resistant bacterial strains and biofilm associated infections. Consequently, attention has been especially devoted to new and emerging nanoparticle-based materials in the field of antimicrobial chemotherapy. The present review discusses the activities of nanoparticles as an antimicrobial means, their mode of action, nanoparticle effect on drug-resistant bacteria, and the risks attendant on their use as antibacterial agents. Factors contributing to nanoparticle performance in the clinical setting, their unique properties, and mechanism of action as antibacterial agents are discussed in detail.

  10. AMDD: Antimicrobial Drug Database

    OpenAIRE

    Danishuddin, Mohd; Kaushal, Lalima; Hassan Baig, Mohd; Khan, Asad U.

    2012-01-01

    Drug resistance is one of the major concerns for antimicrobial chemotherapy against any particular target. Knowledge of the primary structure of antimicrobial agents and their activities is essential for rational drug design. Thus, we developed a comprehensive database, anti microbial drug database (AMDD), of known synthetic antibacterial and antifungal compounds that were extracted from the available literature and other chemical databases, e.g., PubChem, PubChem BioAssay and ZINC, etc. The ...

  11. Avaliação da vanilina como agente antimicrobiano em abacaxi 'Pérola' minimamente processado Evaluation of vanillin as an antimicrobial agent on fresh-cut 'Pérola' pineapple

    Directory of Open Access Journals (Sweden)

    Lucimara Rogéria Antoniolli

    2004-09-01

    Full Text Available Procurou-se avaliar os efeitos da vanilina como agente antimicrobiano, bem como o nível de injúria física como fator de contaminação inicial em abacaxi (Ananas comosus (L. Meer cv. Pérola minimamente processado. Fatias e cubos foram obtidos a partir de frutos sanitizados, descascados e fatiados mecanicamente. Os dois tipos de corte foram imersos, separadamente, em água (controle ou soluções de vanilina 3000 ou 5000mg.L-1, durante 30 segundos. Após período de repouso, para drenagem do excesso de líquido, foram acondicionados em embalagens de polietileno tereftalato e mantidos à temperatura de 4 ± 1°C durante 12 dias. As análises microbiológicas, realizadas em intervalos de 3 dias, envolveram a contagem de microrganismos aeróbios mesófilos e de bolores e leveduras e a determinação de coliformes totais e fecais. A utilização de vanilina mostrou-se ineficiente no controle do crescimento da população de microrganismos aeróbios mesófilos e de bolores e leveduras em abacaxi 'Pérola' minimamente processado. O maior nível de injúrias físicas efetuado nos cubos parece favorecer a contaminação inicial do produto.The purpose of this research was to evaluate the effects of vanillin as an antimicrobial agent, as well as the relationship between the injury degree and initial contamination in fresh-cut pineapple (Ananas comosus (L. Meer cv. Pérola. Slices and cubes were obtained from whole fruits that were mechanically peeled and sliced after sanitization. Both kinds of cutting were dipped in pure water (control or vanillin solutions 3000 or 5000mg.L-1, for 30 seconds. After that, the liquid was drained, slices and cubes were placed in polyethylene terephtalate packages and stored at 4 ± 1°C during 12 days. Microbiological analyses were carried out every 3 days and involved mesophile aerobic counts, molds and yeasts and total and fecal coliforms determination. The use of vanillin was inefficient for the control of mesophile

  12. Group 11 Metal Compounds with Tripodal Bis(imidazole Thioether Ligands. Applications as Catalysts in the Oxidation of Alkenes and as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Armando Varela-Ramírez

    2011-08-01

    very low cytotoxicity on this cell line (5 to 10 times lower than cisplatin and on normal primary cells derived from C57B6 mouse muscle explants, which may make them promising candidates as potential antimicrobial agents and safer catalysts due to low toxicity in human and other mammalian tissues.

  13. Novel antimicrobial activity of a dichloromethane extract obtained from red seaweed Ceramium rubrum (Hudson (Rhodophyta: Florideophyceae against Yersinia ruckeri and Saprolegnia parasitica, agents that cause diseases in salmonids

    Directory of Open Access Journals (Sweden)

    Yurima Cortés

    2014-05-01

    Conclusions: These results may constitute a basis for promising future applied research that could investigate the use of C. rubrum seaweed as a source of antimicrobial compounds against fish pathogens.

  14. In vitro evaluation of antimicrobial agents on Acanthamoeba sp. and evidence of a natural resilience to amphotericin B

    Directory of Open Access Journals (Sweden)

    Alexandre Taravaud

    2017-12-01

    to intrinsic antiacanthamoebal activity. Keywords: Acanthamoeba sp., Antimicrobial agents, Amphotericin B, Resilience

  15. Antimicrobial susceptibility profile of isolates of Aeromonas ...

    African Journals Online (AJOL)

    Antimicrobial susceptibility profile of 45 Aeromonas hydrophila isolates (from different sources) to 11 commonly used antimicrobial agents was determined by agar diffusion technique. Minimal inhibitory concentrations (MICs) of antimicrobial drugs were also determined using amylase property of Aeromonas as end-point ...

  16. Uses of antimicrobial genes from microbial genome

    Science.gov (United States)

    Sorek, Rotem; Rubin, Edward M.

    2013-08-20

    We describe a method for mining microbial genomes to discover antimicrobial genes and proteins having broad spectrum of activity. Also described are antimicrobial genes and their expression products from various microbial genomes that were found using this method. The products of such genes can be used as antimicrobial agents or as tools for molecular biology.

  17. Dimers of coumarin-1,2,3-triazole hybrids bearing alkyl spacer: Design, microwave-assisted synthesis, molecular docking and evaluation as antimycobacterial and antimicrobial agents

    Science.gov (United States)

    Ashok, Dongamanti; Gundu, Srinivas; Aamate, Vikas Kumar; Devulapally, Mohan Gandhi; Bathini, Raju; Manga, Vijjulatha

    2018-04-01

    The present study demonstrated the synthesis of new series of coumarin-1,2,3-triazole hybrids under microwave irradiation method. Several dimers of coumarin based 1,2,3-triazole derivatives were synthesized and their antimycobacterial and antimicrobial activities were investigated. The antimycobacterial activity screening results revealed that compounds 6i and 6j were the most active against Mycobacterium tuberculosis H37Rv strain. The active compounds were further evaluated for cytotoxicity with HEK cell lines and exhibited less % of inhibition. The same synthetic hybrids were evaluated for their antimicrobial activity against various bacterial strains and fungal strains and compounds 6e, 6h, 6i and 6j were found to be the most promising antimicrobial potent molecules. Furthermore, the active compounds against Mycobacterium tuberculosis were evaluated for their molecular docking studies against pantothenate synthetase (PS) enzyme of MTB and the docking results are in well agreement with the antitubercular evaluation results.

  18. Editorial of the Special Issue Antimicrobial Polymers

    Directory of Open Access Journals (Sweden)

    Iolanda Francolini

    2013-09-01

    Full Text Available The special issue “Antimicrobial Polymers” includes research and review papers concerning the recent advances on preparation of antimicrobial polymers and their relevance to industrial settings and biomedical field. Antimicrobial polymers have recently emerged as promising candidates to fight microbial contamination onto surfaces thanks to their interesting properties. In this special issue, the main strategies pursued for developing antimicrobial polymers, including polymer impregnation with antimicrobial agents or synthesis of polymers bearing antimicrobial moieties, were discussed. The future application of these polymers either in industrial or healthcare settings could result in an extremely positive impact not only at the economic level but also for the improvement of quality of life.

  19. Design, Synthesis and Evaluation of Novel Phthalimide Derivatives as in Vitro Anti-Microbial, Anti-Oxidant and Anti-Inflammatory Agents

    OpenAIRE

    Lamie, P.F.; Philoppes, J.N.; El-Gendy, A.O.; Rárová, L. (Lucie); Grúz, J. (Jiří)

    2015-01-01

    Sixteen new phthalimide derivatives were synthesized and evaluated for their in vitro anti-microbial, anti-oxidant and anti-inflammatory activities. The cytotoxicity for all synthesized compounds was also determined in cancer cell lines and in normal human cells. None of the target derivatives had any cytotoxic activity. (ZE)-2-[4-(1-Hydrazono-ethyl) phenyl]isoindoline-1,3-dione (12) showed remarkable anti-microbial activity. Its activity against Bacillus subtilis was 133%, 106% and 88.8% wh...

  20. Synthesis and biological evaluation of (E)-1-(substituted)-3-phenylprop-2-en-1-ones bearing rhodanines as potent anti-microbial agents.

    Science.gov (United States)

    Song, Ming-Xia; Deng, Xian-Qing; Li, Ya-Ru; Zheng, Chang-Ji; Hong, Lan; Piao, Hu-Ri

    2014-10-01

    Herein, we report the design, syntheses and in vitro anti-microbial activity of two series of rhodanines with chalcone moiety. Anti-microbial tests showed that some of the synthesized compounds exhibited good inhibition (MIC = 1-8 µg/mL) against multi-drug-resistant Gram-positive organisms, including methicillin resistant and quinolone-resistant Staphylococcus aureus, in which the compound 4g was found to be the most potent with minimum inhibitory concentration (MIC) value of 1 µg/mL against two methicillin-resistant S. aureus.

  1. Multifactorial antimicrobial wood protectants

    Science.gov (United States)

    Robert D. Coleman; Carol A. Clausen

    2008-01-01

    It is unlikely that a single antimicrobial compound, whether synthetic or natural, will provide the ‘magic bullet’ for eliminating multiple biological agents affecting wood products. Development of synergistic combinations of selected compounds, especially those derived from natural sources, is recognized as a promising approach to improved wood protection. Recent...

  2. 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

    , Enterococcus faecium), 2) zoonotic bacteria (Campylobacter coli/jejuni, Salmonella enterica, Yelsinia enterocolitica), and 3) animal pathogens (E. coli, Staphylococcus aureus, coagulase-negative staphylococci (CNS), Staphylococcus hyicus, Actinobacillus pleuropneumoniae). A total of 3304 bacterial isolates...... 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......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...

  3. Rosin modified cellulose nanofiber as a reinforcing and co-antimicrobial agents in polylactic acid /chitosan composite film for food packaging.

    Science.gov (United States)

    Niu, Xun; Liu, Yating; Song, Yang; Han, Jinquan; Pan, Hui

    2018-03-01

    Cellulose nanofiber (CNF) was modified by rosin and used as a reinforcement filler within a polylactic acid (PLA) matrix. The resulting film was then coated with chitosan (CHT) to prepare a two-layer composite film for antimicrobial food packaging. The FT-IR spectra of rosin modified CNF (R-CNF) displayed a clear peak at 1730cm -1 , which confirmed the successful esterification of CNF by rosin. The R-CNF showed a better dispersion in PLA matrix than CNF and the loading of R-CNF had a significant effect on the mechanical properties of the resulting film. A percolation network was formed when the R-CNF loading was 8%, where the composite film displayed optimum mechanical properties. The antimicrobial test showed that the R-CNF/PLA/CHT composite film exhibited excellent antimicrobial performance against E. coli and B. subtilis, which could be attributed to the synergistic antimicrobial effect of CHT and rosin. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Evaluation of the antimicrobial and physical properties of an orthodontic photo-activated adhesive modified with an antiplaque agent: An in vitro study

    Directory of Open Access Journals (Sweden)

    Chanjyot Singh

    2013-01-01

    Results: The findings indicated that (1 addition of chlorhexidine to the orthodontic composite resin enhanced its antimicrobial properties, (2 there was no significant difference between the bond strengths of the control and the experimental resins tested after 24 h and 25 days and (3 maximum release of chlorhexidine from the modified resin was much higher than the minimum inhibitory concentration level.

  5. Design, Synthesis and Evaluation of Novel Phthalimide Derivatives as in Vitro Anti-Microbial, Anti-Oxidant and Anti-Inflammatory Agents

    Czech Academy of Sciences Publication Activity Database

    Lamie, P.F.; Philoppes, J.N.; El-Gendy, A.O.; Rárová, Lucie; Grúz, Jiří

    2015-01-01

    Roč. 20, č. 9 (2015), s. 16620-16642 ISSN 1420-3049 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : synthesis * phthalimides * anti-microbial Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.465, year: 2015

  6. Synthesis, characterization, and antimicrobial evaluation of a small library of ferrocene-containing acetoacetates and phenyl analogs: the discovery of a potent anticandidal agent.

    Science.gov (United States)

    Radulović, Niko S; Mladenović, Marko Z; Stojanović-Radić, Zorica; Bogdanović, Goran A; Stevanović, Dragana; Vukićević, Rastko D

    2014-08-01

    A library of 16 2-substituted methyl acetoacetates containing ferrocenyl or phenyl units was designed to disclose differences in the antimicrobial activity of ferrocene-containing compounds and their phenyl analogs. Two methyl acetoacetates, whose structures do not contain an aromatic nucleus, were also included in order to probe the inherent activity of the scaffold itself. The acetoacetates were synthesized (low-to-good yields) and fully characterized by spectral (MS, IR, UV-Vis, 1D and 2D NMR) and electrochemical (cyclic voltammetry) techniques. Single-crystal X-ray analysis has been performed for methyl 2-acetyl-2-(ferrocenylmethyl)-5-methylhex-4-enoate. All compounds have demonstrated in vitro antimicrobial activity against six bacterial (three Gram-positive and three Gram-negative) and two fungal strains with minimal inhibitory concentration values of 0.0050-20.6 μmol mL(-1). The most active compound was 2-acetyl-2-(ferrocenylmethyl)-4-methylpent-4-enoate whose activity was comparable to that of nystatin against the yeast Candida albicans. Agglomerative hierarchical clustering statistical analysis of the antimicrobial assay data demonstrated that ferrocene-containing compounds have statistically different and greater antimicrobial activity when compared to their phenyl analogs.

  7. Antimicrobial Activity and Toxicity of Zhumeria Majdae Essential Oil and its Capsulated Form

    Directory of Open Access Journals (Sweden)

    Rahil Emami

    2015-03-01

    Conclusion: It was found that in some cases, encapsulation could lead to better antimicrobial property and less toxicity. Because of high antimicrobial activity, both EO and EFEO of Zhumeria majdae may be used as powerfully antimicrobial agents.

  8. Antimicrobial Resistance

    Science.gov (United States)

    ... least 10 countries (Australia, Austria, Canada, France, Japan, Norway, Slovenia, South Africa, Sweden and the United Kingdom ... plan Global report on surveillance Country situation analysis Policy to combat antimicrobial resistance More on antimicrobial resistance ...

  9. Therapeutic drug monitoring of antimicrobials

    Science.gov (United States)

    Roberts, Jason A; Norris, Ross; Paterson, David L; Martin, Jennifer H

    2012-01-01

    Optimizing the prescription of antimicrobials is required to improve clinical outcome from infections and to reduce the development of antimicrobial resistance. One such method to improve antimicrobial dosing in individual patients is through application of therapeutic drug monitoring (TDM). The aim of this manuscript is to review the place of TDM in the dosing of antimicrobial agents, specifically the importance of pharmacokinetics (PK) and pharmacodynamics (PD) to define the antimicrobial exposures necessary for maximizing killing or inhibition of bacterial growth. In this context, there are robust data for some antimicrobials, including the ratio of a PK parameter (e.g. peak concentration) to the minimal inhibitory concentration of the bacteria associated with maximal antimicrobial effect. Blood sampling of an individual patient can then further define the relevant PK parameter value in that patient and, if necessary, antimicrobial dosing can be adjusted to enable achievement of the target PK/PD ratio. To date, the clinical outcome benefits of a systematic TDM programme for antimicrobials have only been demonstrated for aminoglycosides, although the decreasing susceptibility of bacteria to available antimicrobials and the increasing costs of pharmaceuticals, as well as emerging data on pharmacokinetic variability, suggest that benefits are likely. PMID:21831196

  10. Effectiveness of the antimicrobial removal device, BACTEC 16B medium, and thiol broth in neutralizing antibacterial activities of imipenem, norfloxacin, and related agents.

    OpenAIRE

    Weinberg, E; Shungu, D L; Gadebusch, H H

    1984-01-01

    The Antimicrobial Removal Device (ARD), BACTEC 16B medium, and Thiol broth were evaluated for their effectiveness in reducing the activity of imipenem (IPM), cefoxitin, moxalactam, and ceftazidime in blood samples. In addition, the capability of the ARD and Thiol broth to bind norfloxacin and the ARD to bind oxolinic and nalidixic acids in urine samples was investigated. At the highest concentrations of the drugs tested (32 micrograms/ml for the four beta-lactams and 256 micrograms/ml for the...

  11. Synthesis of silver nanoparticles using the Streptomyces coelicolor klmp33 pigment: An antimicrobial agent against extended-spectrum beta-lactamase (ESBL) producing Escherichia coli

    International Nuclear Information System (INIS)

    Manikprabhu, Deene; Lingappa, K.

    2014-01-01

    The increasing emergence of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) occurred mainly due to continuous persistent exposure to antibiotics causing high morbidity and mortality so studies in controlling this infection are required. In the present investigation, we developed a synthesis for silver nanoparticles employing a pigment produced by Streptomyces coelicolor klmp33, and assessed the antimicrobial activity of these nanoparticles against ESBL producing E. coli. The ESBL producing E. coli were isolated from urine samples collected from the Gulbarga region in India. As can been seen from our studies, the silver nanoparticles having irregular shapes and size of 28–50 nm showed remarkable antimicrobial activity and moreover the synthesis time is just 20 min and thus the same can be used for formulating pharmaceutical remedies. - Highlights: • Silver nanoparticle synthesis by photo-irradiation method in just 20 min • Isolation of ESBL producing E. coli from urine samples from the Gulbarga region. • Antimicrobial activity of silver nanoparticles against ESBL producing E. coli • The minimum inhibitory concentration of silver nanoparticles against ESBL producing E. coli was 40 μL

  12. Synthesis of silver nanoparticles using the Streptomyces coelicolor klmp33 pigment: An antimicrobial agent against extended-spectrum beta-lactamase (ESBL) producing Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Manikprabhu, Deene; Lingappa, K., E-mail: lingappak123@gmail.com

    2014-12-01

    The increasing emergence of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) occurred mainly due to continuous persistent exposure to antibiotics causing high morbidity and mortality so studies in controlling this infection are required. In the present investigation, we developed a synthesis for silver nanoparticles employing a pigment produced by Streptomyces coelicolor klmp33, and assessed the antimicrobial activity of these nanoparticles against ESBL producing E. coli. The ESBL producing E. coli were isolated from urine samples collected from the Gulbarga region in India. As can been seen from our studies, the silver nanoparticles having irregular shapes and size of 28–50 nm showed remarkable antimicrobial activity and moreover the synthesis time is just 20 min and thus the same can be used for formulating pharmaceutical remedies. - Highlights: • Silver nanoparticle synthesis by photo-irradiation method in just 20 min • Isolation of ESBL producing E. coli from urine samples from the Gulbarga region. • Antimicrobial activity of silver nanoparticles against ESBL producing E. coli • The minimum inhibitory concentration of silver nanoparticles against ESBL producing E. coli was 40 μL.

  13. Antimicrobial Food Packaging: Potential & Pitfalls

    Directory of Open Access Journals (Sweden)

    BHANU eMALHOTRA

    2015-06-01

    Full Text Available Nowadays food preservation, quality maintenance, and safety are major growing concerns of the food industry. It is evident that over time consumers’ demand for natural and safe food products with stringent regulations to prevent food-borne infectious diseases. Antimicrobial packaging which is thought to be a subset of active packaging and controlled release packaging is one such promising technology which effectively impregnates the antimicrobial into the food packaging film material and subsequently delivers it over the stipulated period of time to kill the pathogenic microorganisms affecting food products thereby increasing the shelf life to severe folds. This paper presents a picture of the recent research on antimicrobial agents that are aimed at enhancing and improving food quality and safety by reduction of pathogen growth and extension of shelf life, in a form of a comprehensive review. Examination of the available antimicrobial packaging technologies is also presented along with their significant impact on food safety. This article entails various antimicrobial agents for commercial applications, as well as the difference between the use of antimicrobials under laboratory scale and real time applications. Development of resistance amongst microorganisms is considered as a future implication of antimicrobials with an aim to come up with actual efficacies in extension of shelf life as well as reduction in bacterial growth through the upcoming and promising use of antimicrobials in food packaging for the forthcoming research down the line.

  14. Antimicrobial commodities. 3. Antimicrobial treatment for plastics; Kokin seikatsu yohin. 3. Kokin plastic

    Energy Technology Data Exchange (ETDEWEB)

    Tomioka, T. [Matsushita Electric Industrial Co. Ltd., Osaka (Japan)

    1998-06-01

    This paper describes antimicrobial plastics. Antimicrobial agents may sometimes be used to maintain cleanliness on surface of plastics. The antimicrobial agents can be divided into organic agents including natural substance systems and inorganic materials. The organic agents are volatile, can retain their effects even if dust is deposited on the surface, and are utilized as anti-fungus agents. The inorganic systems, which are heat resistant, can withstand plastics molding temperatures, and are used kneaded with plastic materials. The inorganic systems use silver or silver complex, copper and zinc carried or displaced in inorganic oxides. Properties of the carriers produce different features. The action mechanism of a silver antimicrobial agent uses active oxidization of plastic surface by means of catalytic action of silver, and enzymatic inhibition of silver ions. Antimicrobial treatment methods include mixing and kneading with resins, and surface coating. Antimicrobial agents can include those having high reactivity against resins, whereas the antimicrobial treatment and the mold processing must be conceived independently and cooperatively. What is important is not simply the initial antimicrobial characteristics, but their sustainability. Their using environment and required antimicrobial performance require adequate evaluation and verification. 4 refs., 12 figs., 8 tabs.

  15. Use of an Electrostatic Spraying System or the Sprayed Lethality in Container Method To Deliver Antimicrobial Agents onto the Surface of Beef Subprimals To Control Shiga Toxin-Producing Escherichia coli.

    Science.gov (United States)

    Stella, J Max; Luchansky, John B; Miller, Kelsey; Shoyer, Bradley A; Shane, Laura E; McGeary, Lianna; Osoria, Manuela; Stahler, Laura J; Sevart, Nicholas J; Phebus, Randall K; Thippareddi, Harshavardhan; Porto-Fett, Anna C S

    2017-08-01

    The efficacy of an electrostatic spraying system (ESS) and/or the sprayed lethality in container (SLIC) method to deliver antimicrobial agents onto the surface of beef subprimals to reduce levels of Shiga toxin-producing Escherichia coli (STEC) was evaluated. Beef subprimals were surface inoculated (lean side; ca. 5.8 log CFU per subprimal) with 2 mL of an eight-strain cocktail comprising single strains of rifampin-resistant (100 μg/mL) STEC (O26:H11, O45:H2, O103:H2, O104:H4, O111:H - , O121:H19, O145:NM, and O157:H7). Next, inoculated subprimals were surface treated with lauric arginate (LAE; 1%), peroxyacetic acid (PAA; 0.025%), or cetylpyridinium chloride (CPC; 0.4%) by passing each subprimal, with the inoculated lean side facing upward, through an ESS cabinet or via SLIC. Subprimals were then vacuum packaged and stored at 4°C. One set of subprimals was sampled after an additional 2 h, 3 days, or 7 days of refrigerated storage, whereas another set was retreated via SLIC after 3 days of storage with a different one of the three antimicrobial agents (e.g., a subprimal treated with LAE on day 0 was then treated with PAA or CPE on day 3). Retreated subprimals were sampled after 2 h or 4 days of additional storage at 4°C. A single initial application of LAE, PAA, or CPC via ESS or SLIC resulted in STEC reductions of ca. 0.3 to 1.3 log CFU per subprimal after 7 days of storage. However, when subprimals were initially treated with LAE, PAA, or CPC via ESS or SLIC and then separately retreated with a different one of these antimicrobial agents via SLIC on day 3, additional STEC reductions of 0.4 to 1.0 log CFU per subprimal were observed after an additional 4 days of storage. Application of LAE, PAA, or CPC, either alone or in combination, via ESS or SLIC is effective for reducing low levels (ca. 0.3 to 1.6 log CFU) of STEC that may be naturally present on the surface of beef subprimals.

  16. Relation between antimicrobial use and resistance in Belgian pig herds

    OpenAIRE

    Callens, Benedicte; Boyen, Filip; Maes, Dominiek; Haesebrouck, Freddy; Butaye, Patrick; Dewulf, Jeroen

    2011-01-01

    The aim of this study was to determine the link between the characteristics of antimicrobial therapy and occurrence of antimicrobial resistance in Escherichia coli of clinically healthy pigs exposed to antimicrobial treatments. A total of 918 Escherichia coli isolates were obtained from faecal samples, collected from 50 pig herds at the end of the fattening period and susceptibility was tested towards 15 different antimicrobial agents, using the disk diffusion method. The Antimicrobial Resist...

  17. Antimicrobial susceptibility test in Brachyspira pilosicoli strains isolated from commercial layers farms in Colombia PRUEBAS DE SENSIBILIDAD FRENTE A AGENTES ANTIMICROBIANOS EN CEPAS DE Brachyspira pilosicoli AISLADAS A PARTIR DE PONEDORAS COMERCIALES EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Figueroa Ramìrez Judith

    2009-04-01

    Full Text Available Intestinal Spirochaetes of the genus Brachyspira cause important diseases in swine and poultry. An increasing problem in the presentation of resistant strains to the antimicrobial drugs usually used to treat the intestinal spirochaetosis in swine has been evidenced and this could be applicable to the isolations from poultry. There are very few reports of in vitro antimicrobial susceptibility of Brachyspira spp. isolated from birds. In this study the antimicrobial susceptibility of twelve Brachyspira pilosicoli isolates obtain from commercial layers was evaluated against tiamulin, tylosin and lincomycin establishing the Minimum Inhibitory Concentration (MIC by agar dilution technique. All bacteria analyzed were sensitive to tiamulin (MIC ≤0,1μg/ml, and lincomycin (MIC 1μg/ml and resistant to tylosin (MIC 5μg/ml.Las espiroquetas intestinales del género Brachyspira ocasionan enfermedades importantes en porcinos y aves. Se ha evidenciado un problema de incremento en la presentación de cepas resistentes a los antimicrobianos utilizados normalmente para tratar las espiroquetosis intestinales en porcinos, y esto podría ser aplicable a los aislamientos de aves. Hay muy pocos reportes de sensibilidad antimicrobiana in vitro de cepas de Brachyspira spp. Aisladas en aves. En este estudio se evaluó la sensibilidad de doce aislamientos de Brachyspira pilosicoli obtenidos de granjas de ponedoras comerciales a los agentes antimicrobianos tiamulina, tilosina y lincomicina, y se estableció la concentración mínima inhibitoria (CMI mediante la técnica de dilución en agar. Todas las bacterias analizadas fueron sensibles a tiamulina (CMI ≤0,1 μg/ml y lincomicina (CMI 1 μg/ml y resistentes a tilosina (CMI 5 μg/ml.

  18. 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

  19. Complexes of Silver(I Ions and Silver Phosphate Nanoparticles with Hyaluronic Acid and/or Chitosan as Promising Antimicrobial Agents for Vascular Grafts

    Directory of Open Access Journals (Sweden)

    Vojtech Adam

    2013-06-01

    Full Text Available Polymers are currently widely used to replace a variety of natural materials with respect to their favourable physical and chemical properties, and due to their economic advantage. One of the most important branches of application of polymers is the production of different products for medical use. In this case, it is necessary to face a significant disadvantage of polymer products due to possible and very common colonization of the surface by various microorganisms that can pose a potential danger to the patient. One of the possible solutions is to prepare polymer with antibacterial/antimicrobial properties that is resistant to bacterial colonization. The aim of this study was to contribute to the development of antimicrobial polymeric material ideal for covering vascular implants with subsequent use in transplant surgery. Therefore, the complexes of polymeric substances (hyaluronic acid and chitosan with silver nitrate or silver phosphate nanoparticles were created, and their effects on gram-positive bacterial culture of Staphylococcus aureus were monitored. Stages of formation of complexes of silver nitrate and silver phosphate nanoparticles with polymeric compounds were characterized using electrochemical and spectrophotometric methods. Furthermore, the antimicrobial activity of complexes was determined using the methods of determination of growth curves and zones of inhibition. The results of this study revealed that the complex of chitosan, with silver phosphate nanoparticles, was the most suitable in order to have an antibacterial effect on bacterial culture of Staphylococcus aureus. Formation of this complex was under way at low concentrations of chitosan. The results of electrochemical determination corresponded with the results of spectrophotometric methods and verified good interaction and formation of the complex. The complex has an outstanding antibacterial effect and this effect was of several orders higher compared to other

  20. 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

  1. Complexes of silver(I) ions and silver phosphate nanoparticles with hyaluronic acid and/or chitosan as promising antimicrobial agents for vascular grafts.

    Science.gov (United States)

    Chudobova, Dagmar; Nejdl, Lukas; Gumulec, Jaromir; Krystofova, Olga; Rodrigo, Miguel Angel Merlos; Kynicky, Jindrich; Ruttkay-Nedecky, Branislav; Kopel, Pavel; Babula, Petr; Adam, Vojtech; Kizek, Rene

    2013-06-28

    Polymers are currently widely used to replace a variety of natural materials with respect to their favourable physical and chemical properties, and due to their economic advantage. One of the most important branches of application of polymers is the production of different products for medical use. In this case, it is necessary to face a significant disadvantage of polymer products due to possible and very common colonization of the surface by various microorganisms that can pose a potential danger to the patient. One of the possible solutions is to prepare polymer with antibacterial/antimicrobial properties that is resistant to bacterial colonization. The aim of this study was to contribute to the development of antimicrobial polymeric material ideal for covering vascular implants with subsequent use in transplant surgery. Therefore, the complexes of polymeric substances (hyaluronic acid and chitosan) with silver nitrate or silver phosphate nanoparticles were created, and their effects on gram-positive bacterial culture of Staphylococcus aureus were monitored. Stages of formation of complexes of silver nitrate and silver phosphate nanoparticles with polymeric compounds were characterized using electrochemical and spectrophotometric methods. Furthermore, the antimicrobial activity of complexes was determined using the methods of determination of growth curves and zones of inhibition. The results of this study revealed that the complex of chitosan, with silver phosphate nanoparticles, was the most suitable in order to have an antibacterial effect on bacterial culture of Staphylococcus aureus. Formation of this complex was under way at low concentrations of chitosan. The results of electrochemical determination corresponded with the results of spectrophotometric methods and verified good interaction and formation of the complex. The complex has an outstanding antibacterial effect and this effect was of several orders higher compared to other investigated complexes.

  2. Complexes of Silver(I) Ions and Silver Phosphate Nanoparticles with Hyaluronic Acid and/or Chitosan as Promising Antimicrobial Agents for Vascular Grafts

    Science.gov (United States)

    Chudobova, Dagmar; Nejdl, Lukas; Gumulec, Jaromir; Krystofova, Olga; Rodrigo, Miguel Angel Merlos; Kynicky, Jindrich; Ruttkay-Nedecky, Branislav; Kopel, Pavel; Babula, Petr; Adam, Vojtech; Kizek, Rene

    2013-01-01

    Polymers are currently widely used to replace a variety of natural materials with respect to their favourable physical and chemical properties, and due to their economic advantage. One of the most important branches of application of polymers is the production of different products for medical use. In this case, it is necessary to face a significant disadvantage of polymer products due to possible and very common colonization of the surface by various microorganisms that can pose a potential danger to the patient. One of the possible solutions is to prepare polymer with antibacterial/antimicrobial properties that is resistant to bacterial colonization. The aim of this study was to contribute to the development of antimicrobial polymeric material ideal for covering vascular implants with subsequent use in transplant surgery. Therefore, the complexes of polymeric substances (hyaluronic acid and chitosan) with silver nitrate or silver phosphate nanoparticles were created, and their effects on gram-positive bacterial culture of Staphylococcus aureus were monitored. Stages of formation of complexes of silver nitrate and silver phosphate nanoparticles with polymeric compounds were characterized using electrochemical and spectrophotometric methods. Furthermore, the antimicrobial activity of complexes was determined using the methods of determination of growth curves and zones of inhibition. The results of this study revealed that the complex of chitosan, with silver phosphate nanoparticles, was the most suitable in order to have an antibacterial effect on bacterial culture of Staphylococcus aureus. Formation of this complex was under way at low concentrations of chitosan. The results of electrochemical determination corresponded with the results of spectrophotometric methods and verified good interaction and formation of the complex. The complex has an outstanding antibacterial effect and this effect was of several orders higher compared to other investigated complexes

  3. Pan-European monitoring of susceptibility to human-use antimicrobial agents in enteric bacteria isolated from healthy food-producing animals.

    Science.gov (United States)

    de Jong, Anno; Thomas, Valérie; Simjee, Shabbir; Godinho, Kevin; Schiessl, Brigitte; Klein, Ulrich; Butty, Pascal; Vallé, Michel; Marion, Hervé; Shryock, Thomas R

    2012-03-01

    To determine the antimicrobial susceptibility of Escherichia coli, Salmonella, Campylobacter and Enterococcus from cattle, pigs and chickens across the European Union (EU) using uniform methodology. Intestinal samples (1624) were taken at slaughter across five EU countries. Bacteria were isolated in national laboratories, whilst MICs were determined in a central laboratory for key antimicrobials used in human medicine. Clinical resistance was based on CLSI breakpoints and decreased susceptibility based on European Food Safety Authority (EFSA)/EUCAST epidemiological cut-off values. Isolation rates were high for E. coli (n=1540), low for Salmonella (n=201) and intermediate for Campylobacter (n=940) and Enterococcus (n=786). For E. coli and Salmonella, clinical resistance to newer compounds (cefepime, cefotaxime and ciprofloxacin) was absent or low, but decreased susceptibility was apparent, particularly in chicken strains. Resistance to older compounds (except gentamicin) was variable and higher. Colistin resistance was absent for E. coli, but apparent for Salmonella. For Campylobacter jejuni, ciprofloxacin resistance was markedly prevalent for chickens, whereas clinical resistance and decreased susceptibility to erythromycin was absent or very low. For Campylobacter coli, resistance was notably higher. None of the Enterococcus faecium strains was resistant to linezolid, but some were resistant to ampicillin or vancomycin. Resistance to quinupristin/dalfopristin was frequent. Resistance patterns varied widely depending on bacterial species, antibiotics, hosts and region. Resistance varied among countries, particularly for older antimicrobials, but clinical resistance to newer antibiotics used to treat foodborne disease in humans was generally very low. In the absence of resistance to newer compounds in E. coli and Salmonella, the apparent decreased susceptibility should be monitored.

  4. Antimicrobial Peptides (AMPs

    Directory of Open Access Journals (Sweden)

    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.

  5. Sodium and potassium salts of dichloroisocyanuric acid and their hydrates as antimicrobials agents studied by 35Cl-NQR spectroscopy and DFT calculations

    International Nuclear Information System (INIS)

    Walczak, A.; Brycki, B.; Kaczmarek, M.; Poleshchuk, O.Kh.; Ostafin, M.; Nogaj, B.

    2006-01-01

    The electronic structure of dichloroisocyanuric acid derivatives was analysed by 35 Cl-NQR spectroscopy and DFT calculations. Here we concentrate our attention on three different factors: type of metallic substituent (sodium and potassium), temperature of the sample (liquid nitrogen and room) and degree of hydration (an amount of water molecules attached to analysed compounds). In particular, all the variations in 35 Cl-NQR frequencies upon hydration of salts containing sodium and potassium ions are explained as a consequence of H-bonds formation and accompanied effects of charge redistribution. Our studies can be useful in searching for the derivatives of dichloroisocyanuric acid revealing higher antimicrobial activity

  6. Agentes bacterianos enteropatogênicos em suínos de diferentes faixas etárias e perfil de resistência a antimicrobianos de cepas de Escherichia coli e Salmonella spp Enteropathogenic bacterial agents in pigs of different age groups and profile of resistance in strains of Escherichia coli and Salmonella spp. to antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Álvaro Menin

    2008-09-01

    Full Text Available As enterites infecciosas bacterianas provocam severas perdas para a indústria suína em todo o mundo. Os objetivos deste trabalho foram determinar os agentes bacterianos, associados com a ocorrência de diarréia em suínos, em diferentes faixas etárias, no Estado de Santa Catarina, Brasil, e verificar o perfil de resistência das cepas de Escherichia coli e Salmonella spp, frente aos principais antimicrobianos utilizados em granjas de suínos. Os principais gêneros/espécies bacterianos diagnosticados foram Escherichia coli, Clostridium spp, Salmonella spp Brachyspira hyodysenteriae, Brachyspira pilosicoli e Lawsonia intracellularis. Os fatores de virulência de E. coli mais prevalentes na fase de maternidade foram F5 / (K99 20%, F6 / (987P 16,3%, F42 6,8% e F41 5,7%, já nas fases de creche e terminação, predominaram cepas com fimbrias F4 (K88 11,2% e 5,4%, respectivamente. Para E. coli os maiores índices de resistência foram encontrados para oxitetraciclina (94% e tetraciclina (89,5% e os menores índices de resistência para neomicina (55%, ceftiofur (57,4%. Quanto às amostras de Salmonella spp, estas apresentaram maior resistência à oxitetraciclina (77%, e à tetraciclina (42,1% e menor à gentamicina (3,5% e amoxicilina (4,8%.Infectious bacterial enteritis causes severe losses to the swine industry worldwide. The objective of this study was to determine the epidemiology of bacterial agents that are associated with the occurrence of diarrhea in pigs at different age groups, and to verify the profile of resistance of strains of Escherichia coli and Salmonella spp to the main antimicrobial agents. The main bacterial species diagnosed were Escherichia coli, Clostridium spp, Salmonella spp, Brachyspira hyodysenteriae, Brachyspira pilosicoli and Lawsonia intracellularis. The E. coli virulence factors of higher prevalence in preweaning piglets were F5 / (K99 20%, F6 / (987P 16.3%, F42 6.8% and F41 5.7%, whereas at the nursery and with

  7. Synthesis, in-vitro antibacterial, antifungal, and molecular modeling of potent anti-microbial agents with a combined pyrazole and thiophene pharmacophore.

    Science.gov (United States)

    Mabkhot, Yahia Nasser; Kaal, Nahed Ahmed; Alterary, Seham; Al-Showiman, Salim S; Barakat, Assem; Ghabbour, Hazem A; Frey, Wolfgang

    2015-05-14

    Ethyl 5-acetyl-4-methyl-2-(phenylamino)thiophene-3-carboxylate (2) and there derivatives 3a-c, 4, 6a-c and 9a-f were synthesized. The structure of compound 2 was deduced by 1H-NMR, 13C-NMR, FT-IR, MS, microanalysis, and single-crystal X-ray crystallography. The compound crystallized in the monoclinic system, with space group P21/c and cell coordinates a = 8.5752(16) Å, b = 21.046(4) Å, c = 8.2941(12) Å, β = 101.131(6)°, V = 1468.7(4) Å3, and Z = 4. Compounds 2, 3a-c, 4, 5a-c and 9a-f were subjected into in vitro antimicrobial activity tests. Compounds 3a and 3c were more potent than standard drug amphotericin B, showing MIC values of 23.8 ± 0.42 and 24.3 ± 0.68, respectively, against Aspergillus fumigatus while the standard drug MIC was 23.7 ± 0.1. Compound 3c was also more potent (MIC 24.8 ± 0.64) than the standard drug amphotericin B (MIC 19.7 ± 0.2) against Syncephalastrum racemosum. Compounds 4 and 9f also showed promising anti-microbial activity. Molecular modeling was performed for the most active compounds.

  8. Structure-activity relationships and molecular docking studies of chromene and chromene based azo chromophores: A novel series of potent antimicrobial and anticancer agents.

    Science.gov (United States)

    Afifi, Tarek H; Okasha, Rawda M; Ahmed, Hany E A; Ilaš, Janez; Saleh, Tarek; Abd-El-Aziz, Alaa S

    2017-01-01

    The design of novel materials with significant biological properties is a main target in drug design research. Chromene compounds represent an interesting medicinal scaffold in drug replacement systems. This report illustrates a successful synthesis and characterization of two novel series of chromene compounds using multi-component reactions. The synthesis of the first example of azo chromophores containing chromene moieties has also been established using the same methodology. The antimicrobial activity of the new molecules has been tested against seven human pathogens including two Gm+ve, two Gm-ve bacteria, and four fungi, and the results of the inhibition zones with minimum inhibitory concentrations were reported as compared to reference drugs. All the designed compounds showed significant potent antimicrobial activities, among of them, four potent compounds 4b , 4c , 13e , and 13i showed promising MIC from 0.007 to 3.9 µg/mL. In addition, antiproliferative analysis against three target cell lines was examined for the novel compounds. Compounds 4a , 4b , 4c , and 7c possessed significant antiproliferative activity against three cell lines with an IC 50 of 0.3 to 2 µg/mL. Apoptotic analysis was performed for the most potent compounds via caspase enzyme activity assays as a potential mechanism for their antiproliferative effects. Finally, the computational 2D QSAR and docking simulations were accomplished for structure-activity relationship analyses.

  9. Antimicrobial ceramics. Kokinsei ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Yoshinari, T.; Uchida, M. (Shinagawa Fuel Co. Ltd., Nagoya (Japan))

    1993-07-01

    In recent years, the occurrence of infection by methicillin resistant staphylococcus aureus (MRSA), for which almost all antibiotics do not affect, in facilities such as hospitals is causing trouble. The antimicrobial property of silver has been known empirically since the ancient times. However, since 1985, so called silver zeolite in which zeolite carries silver ions has become utilized as an inorganic antimicrobial agent with silver as its constituent. In this article, the effect of inhibiting MRSA propagation of antimicrobial fibers containing silver zeolite is explained centering around the physical properties of silver zeolite. MRSA has resistance against antibiotics, methicillin which is mainly used at present. When the antimicrobial power of silver zeolite is compared with those of copper zeolite and zinc zeolite, the antimicrobial power of silver zeolite is the strongest and further increases as the silver ion concentration in the zeolite increases. Silver zeolite is safe to use and used for tools and clothes to be used in the fields of food and medical care. 12 refs., 3 figs., 8 tabs.

  10. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... Animal & Veterinary Safety & Health Antimicrobial Resistance Animation of Antimicrobial Resistance Share Tweet Linkedin Pin it More sharing options ... of Animation of Antimicrobial Resistance More in Antimicrobial ... Antimicrobial Resistance Monitoring System About NARMS 2015 NARMS Integrated ...

  11. Animation of Antimicrobial Resistance

    Science.gov (United States)

    ... Animal & Veterinary Safety & Health Antimicrobial Resistance Animation of Antimicrobial Resistance Share Tweet Linkedin Pin it More sharing options ... of Animation of Antimicrobial Resistance More in Antimicrobial ... Antimicrobial Resistance Monitoring System About NARMS 2015 NARMS Integrated ...

  12. Bacteroides forsythus: sensibilidade a antimicrobianos em amostras de pacientes portadores de periodontite Bacteroides forsythus: sensitivity to antimicrobial agents in samples from patients with periodontitis

    Directory of Open Access Journals (Sweden)

    Roberto Fraga Moreira LOTUFO

    2001-03-01

    Full Text Available Os autores realizaram teste de sensibilidade antimicrobiana in vitro (técnica de diluição em ágar para 105 cepas de B. forsythus obtidas de pacientes portadores de periodontite. De acordo com o teste realizado, o microrganismo demonstrou ser sensível ao metronidazol (100% das cepas testadas e à amoxicilina (94% das cepas testadas, enquanto 72% e 65% das cepas foram susceptíveis à tetraciclina e ciprofloxacina, respectivamente. O metronidazol e a amoxicilina parecem ser os antimicrobianos indicados para o tratamento de infecções periodontais nas quais B. forsythus seja o patógeno predominante.An in vitro antimicrobial sensitivity test (technique of agar dilution was carried out for 105 clinical isolates of B. forsythus from patients with periodontitis. Metronidazole and amoxicillin were the most efficient drugs and, thus, are indicated for the treatment of periodontal infections in which this microorganism is the most prevalent pathogen.

  13. Looking for new preparations for antibacterial therapy. IV. New antimicrobial agents from the aminoglycoside, macrolide and tetracycline groups in clinical trials.

    Science.gov (United States)

    Karpiuk, Izabela; Tyski, Stefan

    2015-01-01

    This paper is the fourth in a series on the search for new antibacterial therapies, and covers new compounds belonging to the aminoglycoside, macrolide and tetracycline groups of antibiotics. The article describes eight new substances at the clinical trial stage of development. One of them is an aminoglycoside (plazomicin), four are macrolides, collectively known as ketolides (cethromycin, solithromycin, EDP-420 and EDP-788), and the remaining three are members of the tetracycline group (omadacycline, eravacycline, sarecycline). Despite the long-term and very expensive process of collecting documentation proving the efficacy of antimicrobial drugs, there is a possibility, that particular compounds find use as active ingredients of medicinal products allowing for the triumph over the clinically relevant, dangerous bacteria.

  14. Design, Synthesis and Evaluation of Novel Phthalimide Derivatives as in Vitro Anti-Microbial, Anti-Oxidant and Anti-Inflammatory Agents.

    Science.gov (United States)

    Lamie, Phoebe F; Phillopes, John N; El-Gendy, Ahmed O; Rarova, Lucie; Gruz, Jiri

    2015-09-14

    Sixteen new phthalimide derivatives were synthesized and evaluated for their in vitro anti-microbial, anti-oxidant and anti-inflammatory activities. The cytotoxicity for all synthesized compounds was also determined in cancer cell lines and in normal human cells. None of the target derivatives had any cytotoxic activity. (ZE)-2-[4-(1-Hydrazono-ethyl) phenyl]isoindoline-1,3-dione (12) showed remarkable anti-microbial activity. Its activity against Bacillus subtilis was 133%, 106% and 88.8% when compared with the standard antibiotics ampicillin, cefotaxime and gentamicin, respectively. Compound 12 also showed its highest activities in Gram negative bacteria against Pseudomonas aeruginosa where the percentage activities were 75% and 57.6% when compared sequentially with the standard antibiotics cefotaxime and gentamicin. It was also found that the compounds 2-[4-(4-ethyl-3-methyl-5-thioxo-1,2,4-triazolidin-3-yl)phenyl]isoindoline-1,3-dione (13b) and 2-[4-(3-methyl-5-thioxo-4-phenyl-1,2,4-triazolidin-3-yl)phenyl]isoindoline-1,3-dione (13c) had anti-oxidant activity. 4-(N'-{1-[4-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-phenyl]-ethylidene}-hydrazino)-benzenesulfonamide (17c) showed the highest in vitro anti-inflammatory activity of the tested compounds (a decrease of 32%). To determine the mechanism of the anti-inflammatory activity of 17c, a docking study was carried out on the COX-2 enzyme. The results confirmed that 17c had a higher binding energy score (-17.89 kcal/mol) than that of the ligand celecoxib (-17.27 kcal/mol).

  15. Antimicrobial Activity of Tamarindus indica Linn

    African Journals Online (AJOL)

    Patrick Erah

    body pain, jaundice, yellow fever and as blood tonic and skin cleanser. Because of its wide usage and availability, this study was set out to investigate the antimicrobial activity of the plant and to determine the effect of temperature and. pH on the efficacy of the plant as an antimicrobial agent. MATERIALS AND METHODS.

  16. Microbiological characteristics and antimicrobial potential of ...

    African Journals Online (AJOL)

    ... 19mm and Aspergillus fumigatus was the only fungi recorded to be susceptible from the tested isolates. There is a possibility of harnessing the antimicrobial potency of the infusion for the development of antimicrobial agents to combat resistant pathogenic organisms tested for. Key words: Cola nitida and Cola acuminata, ...

  17. Assessment techniques of antimicrobial properties of natural ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... Key words: Medicinal plants, plant extracts, antimicrobial agents, antimicrobial activity. INTRODUCTION. Plant-derived .... terpenes are the essential oils of which monoterpenes, diterpenes and sesquiterpenes form ... technology have created the tools to produce botanical mixtures at a level comparable to ...

  18. Antimicrobial resistance patterns and plasmid profiles of ...

    African Journals Online (AJOL)

    Objectives: To determine the frequency of resistance of Staphylococcus aureus to various antimicrobial agents, and the relationship between antimicrobial resistance of the isolates and carriage of plasmids. Design: A random sampling of milk and meat samples was carried out. Setting: Milk was collected from various dairy ...

  19. Synthesis and characterization of some novel 1,2,4-triazoles, 1,3,4-thiadiazoles and Schiff bases incorporating imidazole moiety as potential antimicrobial agents

    KAUST Repository

    Aouad, Mohamed Reda

    2015-05-23

    (1,4,5-Triphenylimidazol-2-yl-thio)butyric acid hydrazide (3) was obtained via alkylation of 1,4,5-triphenylimidazol-2- thiol (1) with ethylbromobutyrate, followed by addition of hydrazine hydrate. Treatment of acid hydrazide 3 with carbon disulfide in an ethanolic potassium hydroxide solution gave the intermediate potassium dithiocarbazinate salt, which was cyclized to 4-amino-5-[(1,4,5-triphenylimidazol- -2-yl)thiopropyl]-2H-1,2,4-triazole-3-thione (4) in the presence of hydrazine hydrate. Condensation of compound 3 with alkyl/arylisothiocyanate afforded the corresponding 1-[4-(1,4,5-triphenylimidazol-2-ylthio)butanoyl]-4-alkyl/arylthiosemicarbazides (5-7), which upon refluxing with sodium hydroxide, yielded the corresponding 1,2,4-triazole - -3-thiols 8-10. Under acidic conditions, compounds 4-6 were converted to aminothiadiazoles 11-13. Moreover, the series of Schiff bases 14-18 were synthesized from the condensation of compound 3 with different aromatic aldehydes. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral analyses. They were also preliminarily screened for their antimicrobial activity.

  20. Synthesis and characterization of some novel 1,2,4-triazoles, 1,3,4-thiadiazoles and Schiff bases incorporating imidazole moiety as potential antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Aouad Mohamed Reda

    2015-06-01

    Full Text Available (1,4,5-Triphenylimidazol-2-yl-thiobutyric acid hydrazide (3 was obtained via alkylation of 1,4,5-triphenylimidazol-2- thiol (1 with ethylbromobutyrate, followed by addition of hydrazine hydrate. Treatment of acid hydrazide 3 with carbon disulfide in an ethanolic potassium hydroxide solution gave the intermediate potassium dithiocarbazinate salt, which was cyclized to 4-amino-5-[(1,4,5-triphenylimidazol- -2-ylthiopropyl]-2H-1,2,4-triazole-3-thione (4 in the presence of hydrazine hydrate. Condensation of compound 3 with alkyl/arylisothiocyanate afforded the corresponding 1-[4-(1,4,5-triphenylimidazol-2-ylthiobutanoyl]-4-alkyl/arylthiosemicarbazides (5-7, which upon refluxing with sodium hydroxide, yielded the corresponding 1,2,4-triazole - -3-thiols 8-10. Under acidic conditions, compounds 4-6 were converted to aminothiadiazoles 11-13. Moreover, the series of Schiff bases 14-18 were synthesized from the condensation of compound 3 with different aromatic aldehydes. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral analyses. They were also preliminarily screened for their antimicrobial activity.

  1. In vitro activity of antimicrobial compounds against Xylella fastidiosa, the causal agent of the olive quick decline syndrome in Apulia (Italy).

    Science.gov (United States)

    Bleve, Gianluca; Gallo, Antonia; Altomare, Claudio; Vurro, Maurizio; Maiorano, Gabriele; Cardinali, Angela; D'Antuono, Isabella; Marchi, Guido; Mita, Giovanni

    2018-03-01

    Olive quick decline syndrome (OQDS) causes severe damages to the olive trees in Salento (Apulia, Italy) and poses a severe threat for the agriculture of Mediterranean countries. DNA-based typing methods have pointed out that OQDS is caused by a single outbreak strain of Xylella fastidiosa subsp. pauca referred to as CoDiRO or ST53. Since no effective control measures are currently available, the objective of this study was to evaluate in vitro antimicrobial activities of different classes of compounds against Salento-1 isolated by an OQDS affected plant and classified as ST53. A bioassay based on agar disk diffusion method revealed that 17 out of the 32 tested antibiotics did not affect bacterial growth at a dose of 5 μg disk-1. When we assayed micro-, ultra- and nano-filtered fractions of olive mill wastewaters, we found that the micro-filtered fraction resulted to be the most effective against the bacterium. Moreover, some phenolics (4-methylcathecol, cathecol, veratric acid, caffeic acid, oleuropein) were active in their pure form. Noteworthy, also some fungal extracts and fungal toxins showed inhibitory effects on bacterial growth. Some of these compounds can be further explored as potential candidate in future applications for curative/preventive treating OQDS-affected or at-risk olive plants.

  2. Zinc and copper in animal feed – development of resistance and co-resistance to antimicrobial agents in bacteria of animal origin

    Directory of Open Access Journals (Sweden)

    Siamak Yazdankhah

    2014-09-01

    Full Text Available Farmed animals such as pig and poultry receive additional Zn and Cu in their diets due to supplementing elements in compound feed as well as medical remedies. Enteral bacteria in farmed animals are shown to develop resistance to trace elements such as Zn and Cu. Resistance to Zn is often linked with resistance to methicillin in staphylococci, and Zn supplementation to animal feed may increase the proportion of multiresistant E. coli in the gut. Resistance to Cu in bacteria, in particular enterococci, is often associated with resistance to antimicrobial drugs like macrolides and glycopeptides (e.g. vancomycin. Such resistant bacteria may be transferred from the food-producing animals to humans (farmers, veterinarians, and consumers. Data on dose-response relation for Zn/Cu exposure and resistance are lacking; however, it seems more likely that a resistance-driven effect occurs at high trace element exposure than at more basal exposure levels. There is also lack of data which could demonstrate whether Zn/Cu-resistant bacteria may acquire antibiotic resistance genes/become antibiotics resistant, or if antibiotics-resistant bacteria are more capable to become Zn/Cu resistant than antibiotics-susceptible bacteria. Further research is needed to elucidate the link between Zn/Cu and antibiotic resistance in bacteria.

  3. Synthesis of formazans from Mannich base of 5-(4-chlorophenyl amino-2-mercapto-1,3,4-thiadiazole as antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Pramilla Sah

    2014-04-01

    Full Text Available 5-(4-Chlorophenyl amino-2-mercapto-1,3,4-thiadiazole (I was refluxed with formaldehyde and ammonium chloride in ethanol yielding the Mannich base 5-(4-chloro phenyl amino-3-aminomethyl-2-mercapto-1,3,4-thiadiazole (II. Esterification with 4-chloro-(2,6-dinitro phenoxy-ethyl acetate (III under anhydrous conditions gave the intermediate (IV. Subsequent hydrazinolysis with hydrazine hydrate gave the corresponding hydrazide 3-amino methyl-5-(4-chloro phenyl amino-2-mercapto-4′-(2′,6′-dinitro phenoxy-acetyl hydrazide (V. The hydrazide was converted into the Schiff bases (VIa–b by reacting with 2-chlorobenzaldehyde and 3-methoxy-4-hydroxy benzaldehyde in presence of methanol containing 2–3 drops of acetic acid. Diazotisation with aromatic amines, sulphanilic acid and sulphur drugs gave the formazans (VIIa–g respectively. Chemical structures have been established by elemental analysis and the spectral techniques of FTIR, 1H NMR and mass. Antimicrobial activity (in vitro was evaluated against the two pathogenic bacterial strains. Escherichia coli and Salmonella typhi, three fungal strains Aspergillus niger, Penicillium species and Candida albicans. The compounds have shown moderate activity.

  4. Antimicrobial drug use in a small Indian community hospital

    DEFF Research Database (Denmark)

    Blomberg, M; Jensen, M Blomberg; Henry, A

    2010-01-01

    -trimoxazole, ciprofloxacin and metronidazole were most commonly used and all antimicrobial drugs were given empirically with no confirmation of the infective agent. Reports of increasing resistance to antimicrobial drugs in India, and elsewhere, necessitates a focus on how antimicrobials drugs are used in relation...

  5. CARACTERIZACIÓN MORFOLÓGICA DE PELÍCULAS BIODEGRADABLES A PARTIR DE ALMIDÓN MODIFICADO DE YUCA, AGENTE ANTIMICROBIANO Y PLASTIFICANTE CARACTERIZAÇÃO MORFOLÓGICA DE FILMES BIODEGRADÁVEIS A PARTIR DE AMIDO MODIFICADO DE MANDIOCA, AGENTE ANTIMICROBIANO E PLASTIFICANTE MORPHOLOGICAL CHARACTERIZATION OF BIODEGRADABLE FILMS MADE FROM MODIFIED CASSAVA STARCH, ANTIMICROBIAL AGENT AND PLASTICIZER

    Directory of Open Access Journals (Sweden)

    REINALDO VELASCO M

    2012-12-01

    propriedades microestruturais e mecânicas dos amidos termoplásticos, que são essenciais para a continuidade no estudo de filmes biodegradáveisIt was evaluated the morphological surface of thermoplastic starch (TPS obtained from three modified cassava starch varieties, plasticizer and an antimicrobial agent. The films was made by blown extrusion and extended over a slide and then was taken photomicrographs with 4x and 10x objectives. It was used High Resolution Optical Microscopy to image characterization. The technique showed the effect of plasticizer addition over the starch films microstructure, it was found some inhomogeneity; however was identified some smooth regions related to form and size of starch granule, plasticizer concentration and extrusion variables process like velocity screw and temperature profile. This research contributed to characterize microstructural properties and gave some insights about the mechanical behaviour of TPS films, needed to study and make biodegradable films.

  6. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... video) Animation of Antimicrobial Resistance (text version) Arabic Translation of Animation of Antimicrobial Resistance Chinese Translation of Animation of Antimicrobial Resistance French Translation of ...

  7. Antimicrobial textiles.

    Science.gov (United States)

    McArthur, J Vaun; Tuckfield, R C; Baker-Austin, C

    2012-01-01

    Bacteria have evolved unique mechanisms that allow them survive in the presence of strong selection pressures. Included in these mechanisms is the ability to share genetic determinants among and between species of bacteria thus spreading metal or antibiotic resistance traits quickly. The textile industry in response to demand has developed antimicrobial fabrics by the addition of bactericidal compounds during production. Some of these antimicrobials include metal nanoparticles, quaternary ammonia compounds, and broad spectrum compounds like triclosan. Bacteria have already expressed resistance to each of these bactericides. Here we discuss the evolutionary and ecological consequences of antimicrobial textiles in terms of co-selection. We predict that continued use of such materials could result in increased and widespread resistance to specific antimicrobials, especially metals, with an increased resistance to antibiotics. Such increases have the potential to find their way into other bacterial populations of human pathogens leading to serious and unintended public health consequences.

  8. Antimicrobial Pesticides

    Science.gov (United States)

    ... may be harboring disease organisms. Determining human and ecological risks from exposure to antimicrobial pesticides requires different ... Open Government Regulations.gov Subscribe USA.gov White House Ask. Contact Us Hotlines FOIA Requests Frequent Questions ...

  9. Antimicrobial resistance mechanisms among Campylobacter.

    Science.gov (United States)

    Wieczorek, Kinga; Osek, Jacek

    2013-01-01

    Campylobacter jejuni and Campylobacter coli are recognized as the most common causative agents of bacterial gastroenteritis in the world. Humans most often become infected by ingesting contaminated food, especially undercooked chicken, but also other sources of bacteria have been described. Campylobacteriosis is normally a self-limiting disease. Antimicrobial treatment is needed only in patients with more severe disease and in those who are immunologically compromised. The most common antimicrobial agents used in the treatment of Campylobacter infections are macrolides, such as erythromycin, and fluoroquinolones, such as ciprofloxacin. Tetracyclines have been suggested as an alternative choice in the treatment of clinical campylobacteriosis but in practice are not often used. However, during the past few decades an increasing number of resistant Campylobacter isolates have developed resistance to fluoroquinolones and other antimicrobials such as macrolides, aminoglycosides, and beta-lactams. Trends in antimicrobial resistance have shown a clear correlation between use of antibiotics in the veterinary medicine and animal production and resistant isolates of Campylobacter in humans. In this review, the patterns of emerging resistance to the antimicrobial agents useful in treatment of the disease are presented and the mechanisms of resistance to these drugs in Campylobacter are discussed.

  10. Antimicrobial Resistance Mechanisms among Campylobacter

    Science.gov (United States)

    2013-01-01

    Campylobacter jejuni and Campylobacter coli are recognized as the most common causative agents of bacterial gastroenteritis in the world. Humans most often become infected by ingesting contaminated food, especially undercooked chicken, but also other sources of bacteria have been described. Campylobacteriosis is normally a self-limiting disease. Antimicrobial treatment is needed only in patients with more severe disease and in those who are immunologically compromised. The most common antimicrobial agents used in the treatment of Campylobacter infections are macrolides, such as erythromycin, and fluoroquinolones, such as ciprofloxacin. Tetracyclines have been suggested as an alternative choice in the treatment of clinical campylobacteriosis but in practice are not often used. However, during the past few decades an increasing number of resistant Campylobacter isolates have developed resistance to fluoroquinolones and other antimicrobials such as macrolides, aminoglycosides, and beta-lactams. Trends in antimicrobial resistance have shown a clear correlation between use of antibiotics in the veterinary medicine and animal production and resistant isolates of Campylobacter in humans. In this review, the patterns of emerging resistance to the antimicrobial agents useful in treatment of the disease are presented and the mechanisms of resistance to these drugs in Campylobacter are discussed. PMID:23865047

  11. Prevention of ventilator-associated pneumonia, mortality and all intensive care unit acquired infections by topically applied antimicrobial or antiseptic agents: a meta-analysis of randomized controlled trials in intensive care units.

    Science.gov (United States)

    Pileggi, Claudia; Bianco, Aida; Flotta, Domenico; Nobile, Carmelo G A; Pavia, Maria

    2011-06-24

    Given the high morbidity and mortality attributable to ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients, prevention plays a key role in the management of patients undergoing mechanical ventilation. One of the candidate preventive interventions is the selective decontamination of the digestive or respiratory tract (SDRD) by topical antiseptic or antimicrobial agents. We performed a meta-analysis to investigate the effect of topical digestive or respiratory tract decontamination with antiseptics or antibiotics in the prevention of VAP, of mortality and of all ICU-acquired infections in mechanically ventilated ICU patients. A meta-analysis of randomised controlled trials was performed. The U.S. National Library of Medicine's MEDLINE database, Embase, and Cochrane Library computerized bibliographic databases, and reference lists of selected studies were used. Selection criteria for inclusion were: randomised controlled trials (RCTs); primary studies; examining the reduction of VAP and/or mortality and/or all ICU-acquired infections in ICU patients by prophylactic use of one or more of following topical treatments: 1) oropharyngeal decontamination using antiseptics or antibiotics, 2) gastrointestinal tract decontamination using antibiotics, 3) oropharyngeal plus gastrointestinal tract decontamination using antibiotics and 4) respiratory tract decontamination using antibiotics; reported enough data to estimate the odds ratio (OR) or risk ratio (RR) and their variance; English language; published through June 2010. A total of 28 articles met all inclusion criteria and were included in the meta-analysis. The overall estimate of efficacy of topical SDRD in the prevention of VAP was 27% (95% CI of efficacy = 16% to 37%) for antiseptics and 36% (95% CI of efficacy = 18% to 50%) for antibiotics, whereas in none of the meta-analyses conducted on mortality was a significant effect found. The effect of topical SDRD in the prevention of all ICU

  12. Antimicrobial resistance of thermophilic Campylobacter

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Engberg, J.

    2001-01-01

    Campylobacter has become the leading cause of zoonotic enteric infections in developed and developing countries world-wide. Antimicrobial resistance has emerged among Campylobacter mainly as a consequence of the use of antimicrobial agents in food animal production. Resistance to drugs of choice...... for the treatment of infections, macrolides and fluoroquinolones has emerged as a clinical problem and interventions to reduce this are recommended. Resistance to fluoroquinolones and macrolides is mediated by chromosomal mutations. Resistance to other relevant antimicrobial agents, mediated by acquired resistance...... genes, has not become widespread so far. However, resistance genes originating from both Gram-positive and Gram-negative bacterial species have been found, showing the potential for acquired resistance to emerge in Campylobacter....

  13. Antimicrobial susceptibility of Lactobacillus rhamnosus

    NARCIS (Netherlands)

    Korhonen, J.M.; Hoek, van A.H.A.M.; Saarela, M.; Huys, G.; Tosi, L.; Mayrhofer, S.; Wright, A.

    2010-01-01

    We aimed to determine the minimum inhibitory concentrations (MICs) of Lactobacillus rhamnosus (n=75) strains, to study their antibiotic resistance genes with microarray, and to assess the microbiological cut-off values of tested antimicrobial agents. L. rhamnosus strains were tested with agar

  14. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... Veterinary Home Animal & Veterinary Safety & Health Antimicrobial Resistance Animation of Antimicrobial Resistance Share Tweet Linkedin Pin it ... Veterinary Medicine is cited as the corporate author. Animation Animation of Antimicrobial Resistance (video) Animation of Antimicrobial ...

  15. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... Antimicrobial Resistance More in Antimicrobial Resistance National Antimicrobial Resistance Monitoring System About NARMS 2015 NARMS Integrated Report Data Meetings and Publications Resources Judicious Use of Antimicrobials Page Last Updated: ...

  16. Antimicrobial susceptibility pattern of Vibrio cholerae 01 strains ...

    African Journals Online (AJOL)

    Conclusion: Significant proportion of V. cholerae 0l strains in Dar es Salaam were resistant to commonly used antimicrobial agents during the two years of the study. Therefore, there is a great need to control the utilisation of antimicrobial agents in cholera control, in addition to continuing carrying out surveillance of ...

  17. Chemical composition and evaluation of antimicrobial properties of ...

    African Journals Online (AJOL)

    Jane

    2011-10-17

    Oct 17, 2011 ... Key words: Rosmarinus officinalis L., essential oil, chemical composition, antimicrobial properties. INTRODUCTION. Even though ... tuations of the antimicrobial agent(s), which usually are prepared in serial two fold dilutions, .... However, the role of other minor compounds should not be neglected. Gill et al.

  18. Monitoring of antimicrobial resistance among food animals: Principles and limitations

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller

    2004-01-01

    Large amounts of antimicrobial agents are in the production of food animals used for therapy and prophylactics of bacterial infections and in feed to promote growth. The use of antimicrobial agents causes problems in the therapy of infections through the selection for resistance among bacteria pa...

  19. ANTIMICROBIAL ACTIVITY OF THE ESSENTIAL OIL OF Myrtus ...

    African Journals Online (AJOL)

    2015-02-05

    Feb 5, 2015 ... a tendency to replace synthetic antimicrobials with natural alternative agents [1]. Plant based products are among the alternative agents examined in order to replace conventional antibiotics. Accordingly, extensive researches have been carried out in order to evaluate the antimicrobial effect of the essential ...

  20. Synthesis and antimicrobial activity of guanylhydrazones. Synthesis of 2-(2-methylthio-2-aminovinyl)-1-methylpyridinium iodides and 2-(2-methylthio-2-aminovinyl)-1-methylquinolinium iodides as potential radioprotective and anticancer agents

    International Nuclear Information System (INIS)

    Almassian, B.

    1985-01-01

    The finding of appreciable antileukemic activity in a series of 2-(2-methylthio-2-amino)vinyl-1-methylquinolinium iodides (Foye et al., 1980, 1983) suggested that greater basicity, as compared with the corresponding dithioacetic acids, was contributing to the increase in activity. The addition of a greater degree of basicity in the design of anticancer possibilities in this series was considered worth investigation, particularly in view of the activity of a series of bis(quanylhydrazones) synthesized at Lederle Laboratories. Accordingly, a series of guanylhydrazones of 4-pyridine-,2-pyridine- and 4-quinolinecarboxyaldehydes was synthesized for anticancer as well as antibacterial screening. Also, substitution of additional basic functions in the 2-(2-methylthio-2-amino) vinyl-1-methylquinolinium and pyridinium iodide series has been made. Appreciable antimicrobial activities have been found with both 2-pyridine and 4-quinolinealdehyde guanylhydrazones, as well as with 2-(2-methylthio-2-amino)vinyl-1-methyl-pyridinium iodides. The overall approach to the synthesis of potential anticancer agents in this project is thus to observe the effect of increasing basicity of these compounds on DNA binding and anticancer activity

  1. 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...

  2. Antimicrobial resistance

    DEFF Research Database (Denmark)

    Llor, Carl; Bjerrum, Lars

    2014-01-01

    Antimicrobial resistance is a global public health challenge, which has accelerated by the overuse of antibiotics worldwide. Increased antimicrobial resistance is the cause of severe infections, complications, longer hospital stays and increased mortality. Overprescribing of antibiotics......-the-counter sale of antibiotics, the use of antimicrobial stewardship programmes, the active participation of clinicians in audits, the utilization of valid rapid point-of-care tests, the promotion of delayed antibiotic prescribing strategies, the enhancement of communication skills with patients with the aid...... is associated with an increased risk of adverse effects, more frequent re-attendance and increased medicalization of self-limiting conditions. Antibiotic overprescribing is a particular problem in primary care, where viruses cause most infections. About 90% of all antibiotic prescriptions are issued by general...

  3. Actividad “in vitro” de 10 antimicrobianos frente a bacterias anaerobias: Estudio multicéntrico, 1999-2002 “In vitro” activity of ten antimicrobial agents against anaerobic bacteria. A collaborative study, 1999-2002

    Directory of Open Access Journals (Sweden)

    M. Litterio

    2004-09-01

    . Metronidazole and piperacillin-tazobactam were the most active antimicrobial agents tested and exhibited MIC90values of £ 2 µg/ml and £ 4 µg/ml against gram-negative organisms, and £ 2 µg/ml, and £ 8 µg/ml against gram-positive organisms, respectively. Among b-lactams the activity against gram-negative rods was in the following order: imipenem> piperacillin > cefoxitin > ceftriaxone > ampicillin. Among the gram-positive bacteria the decreased activity was: piperacillin> imipenem> cefoxitin > ceftriaxone > ampicillin. The majority of the species studied showed different degrees of resistance to clindamycin and azitromycin. Nevertheless, 90% of Fusobacterium nucleatum and Porphyromonas spp. isolates were inhibited by 0.125 mg/ml of clindamycin and azitromycin, respectively.

  4. Antimicrobial Efficacy of Emblica Officinalis Fruit Extracts on S. Mutans, E. Faecalis and C. Albicans

    Directory of Open Access Journals (Sweden)

    Shrudha Potdar

    2014-01-01

    Conclusion: Emblica officinalis could be considered as an effective antimicrobial agent. The antimicrobial activities can be enhanced if the phytoactive components are purified and adequate dosage determined for proper administration.

  5. Cationic Antimicrobial Polymers and Their Assemblies

    Science.gov (United States)

    Carmona-Ribeiro, Ana Maria; de Melo Carrasco, Letícia Dias

    2013-01-01

    Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs). The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications. PMID:23665898

  6. Antimicrobial food packaging: potential and pitfalls

    Science.gov (United States)

    Malhotra, Bhanu; Keshwani, Anu; Kharkwal, Harsha

    2015-01-01

    Nowadays food preservation, quality maintenance, and safety are major growing concerns of the food industry. It is evident that over time consumers’ demand for natural and safe food products with stringent regulations to prevent food-borne infectious diseases. Antimicrobial packaging which is thought to be a subset of active packaging and controlled release packaging is one such promising technology which effectively impregnates the antimicrobial into the food packaging film material and subsequently delivers it over the stipulated period of time to kill the pathogenic microorganisms affecting food products thereby increasing the shelf life to severe folds. This paper presents a picture of the recent research on antimicrobial agents that are aimed at enhancing and improving food quality and safety by reduction of pathogen growth and extension of shelf life, in a form of a comprehensive review. Examination of the available antimicrobial packaging technologies is also presented along with their significant impact on food safety. This article entails various antimicrobial agents for commercial applications, as well as the difference between the use of antimicrobials under laboratory scale and real time applications. Development of resistance amongst microorganisms is considered as a future implication of antimicrobials with an aim to come up with actual efficacies in extension of shelf life as well as reduction in bacterial growth through the upcoming and promising use of antimicrobials in food packaging for the forthcoming research down the line. PMID:26136740

  7. Cationic Antimicrobial Polymers and Their Assemblies

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2013-05-01

    Full Text Available Cationic compounds are promising candidates for development of antimicrobial agents. Positive charges attached to surfaces, particles, polymers, peptides or bilayers have been used as antimicrobial agents by themselves or in sophisticated formulations. The main positively charged moieties in these natural or synthetic structures are quaternary ammonium groups, resulting in quaternary ammonium compounds (QACs. The advantage of amphiphilic cationic polymers when compared to small amphiphilic molecules is their enhanced microbicidal activity. Besides, many of these polymeric structures also show low toxicity to human cells; a major requirement for biomedical applications. Determination of the specific elements in polymers, which affect their antimicrobial activity, has been previously difficult due to broad molecular weight distributions and random sequences characteristic of radical polymerization. With the advances in polymerization control, selection of well defined polymers and structures are allowing greater insight into their structure-antimicrobial activity relationship. On the other hand, antimicrobial polymers grafted or self-assembled to inert or non inert vehicles can yield hybrid antimicrobial nanostructures or films, which can act as antimicrobials by themselves or deliver bioactive molecules for a variety of applications, such as wound dressing, photodynamic antimicrobial therapy, food packing and preservation and antifouling applications.

  8. The interaction of fiber, supplied by distillers dried grains with solubles, with an antimicrobial and a nutrient partitioning agent on nitrogen balance, water utilization, and energy digestibility in finishing pigs.

    Science.gov (United States)

    Pilcher, C M; Arentson, R; Patience, J F

    2015-03-01

    The objective of this study was to determine if a higher-fiber diet alters the response of finishing pigs to an antimicrobial (tylosin phosphate [TP]) and a nutrient partitioning agent (ractopamine HCl [RAC]) in terms of N and water utilization and energy digestibility. Seventy-two gilts (initial BW = 107.4 ± 4.2 kg) were blocked by weight and allotted to 1 of 8 dietary treatments. Treatments were arranged as a 2 × 2 × 2 factorial: distillers dried grains with solubles (DDGS; 0 vs. 30%), RAC (0 mg of RAC/kg and 0.70% standardized ileal digestible [SID] Lys vs. 5 mg of RAC/kg and 0.95% SID Lys) and TP (0 vs. 44 mg of TP/kg). Pig was the experimental unit, with 9 replications per treatment. Pigs were housed in individual metabolism crates and fed treatment diets for 17 d. Feed was provided twice daily, as much as the pigs could consume within 1 h per meal, and water was provided to the pigs between feeding periods, ad libitum. Fecal and urine collection occurred on d 7 and 8 and on d 15 and 16, for sampling periods 1 and 2, respectively. Pigs fed the DDGS diets had reduced ADG ( interaction ( 0.10). Pigs fed DDGS diets had higher N intake ( < 0.01) and higher fecal ( < 0.0001) and urinary ( < 0.01) N excretion with no difference in N retention (g/d). Overall, RAC increased N retention by 33% ( < 0.0001) and the response to RAC was similar in both corn-soybean meal-based and corn-soybean meal-DDGS-based diets. Tylosin phosphate tended to improve growth performance in pigs fed corn-soybean meal-based diets but not in diets containing 30% DDGS; however, this response was not explained by changes in N balance or in energy digestibility.

  9. Learning from agriculture: understanding low-dose antimicrobials as drivers of resistome expansion

    OpenAIRE

    Yaqi eYou; Ellen K. Silbergeld

    2014-01-01

    Antimicrobial resistance is a growing public health challenge worldwide, with agricultural use of antimicrobials being one major contributor to the emergence and dissemination of antimicrobial resistance. Globally, most antimicrobials are used in industrial food animal production, a major context for microbiomes encountering low-doses or subtherapeutic-levels of antimicrobial agents from all mechanistic classes. This modern practice exerts broad eco-evolutionary effects on the gut microbiome ...

  10. Cyclodextrins: A Weapon in the Fight Against Antimicrobial Resistance

    Science.gov (United States)

    Wong, Chew Ee; Dolzhenko, Anton V.; Lee, Sui Mae; Young, David James

    Antimicrobial resistance poses one of the most serious global challenges of our age. Cyclodextrins (CDs) are widely utilized excipients in formulations because of their solubilizing properties, low toxicity, and low inflammatory response. This review summarizes recent investigations of antimicrobial agents involving CDs and CD-based antimicrobial materials. CDs have been employed for antimicrobial applications either through formation of inclusion complexes or by chemical modification of their hydroxyl groups to tailor pharmaceutically active compounds. Applications of these CD inclusion complexes include drug delivery, antimicrobial coatings on materials (e.g., biomedical devices and implants) and antimicrobial dressings that help to prevent wound infections. There are relatively limited studies of chemically modified CDs with antimicrobial activity. The mechanism of action of antimicrobial CD inclusion complexes and derivatives needs further elucidation, but activity of CDs and their derivatives is often associated with their interaction with bacterial cell membranes.

  11. Synthetic biology of antimicrobial discovery

    Science.gov (United States)

    Zakeri, Bijan; Lu, Timothy K.

    2012-01-01

    Antibiotic discovery has a storied history. From the discovery of penicillin by Sir Alexander Fleming to the relentless quest for antibiotics by Selman Waksman, the stories have become like folklore, used to inspire future generations of scientists. However, recent discovery pipelines have run dry at a time when multidrug resistant pathogens are on the rise. Nature has proven to be a valuable reservoir of antimicrobial agents, which are primarily produced by modularized biochemical pathways. Such modularization is well suited to remodeling by an interdisciplinary approach that spans science and engineering. Herein, we discuss the biological engineering of small molecules, peptides, and non-traditional antimicrobials and provide an overview of the growing applicability of synthetic biology to antimicrobials discovery. PMID:23654251

  12. Avaliação da atividade in vitro do cefetamet e outros agentes antimicrobianos diante de bactérias isoladas de infecções do trato respiratório In vitro activity of cefetamet compared with other antimicrobial agents against bacteria isolated from respiratory tract infections

    Directory of Open Access Journals (Sweden)

    C.M.F. Mendes

    1997-03-01

    Full Text Available O cefetamet pivoxil é uma nova cefalosporina de administração oral, estável à ação de beta-lactamases. A resistência aos antimicrobianos entre os patógenos isolados do trato respiratório tem-se tornado um importante problema tanto para o clínico como para o microbiologista, com os padrões de sensibilidade variando consideravelmente, de acordo com a localização geográfica, daí, também, a importância de sempre se realizar o teste de sensibilidade in vitro dos microrganismos isolados. OBJETIVO. Avaliar a atividade in vitro do cefetamet, o metabólito microbiologicamente ativo da pré-droga cefetamet pivoxil, comparativamente com outros 11 antibióticos, perante 376 bactérias recentemente isoladas de pacientes com infecções do trato respiratório. MÉTODOS. O estudo comparativo da atividade in vitro do cefetamet e outros 11 agentes antimicrobianos foi verificado perante 376 microrganismos isolados de pacientes com infecções do trato respiratório, durante período de estudo de seis meses. Por meio da determinação da concentração inibitória mínima (MIC dos antibióticos testados, verificou-se a sensibilidade das bactérias isoladas. RESULTADOS. O cefetamet mostrou alta atividade in vitro diante das bactérias testadas, possuindo um espectro de atividade semelhante ao de outras cefalosporinas orais recentemente desenvolvidas. A excelente atividade do cefetamet perante bactérias produtoras de beta-lactamase, como a Moraxella catarrhalis, pode ser atribuída à sua estabilidade ante essas enzimas. O cefetamet na concentração de 1,0µg/mL foi capaz de inibir 97% de todas as bactérias testadas. CONCLUSÃO. O estudo realizado nas 376 cepas, em que obtivemos o resultado do MIC90 dos 12 antimicrobianos testados, confirma a excelente atividade do cefetamet diante dos patógenos isolados do trato respiratório.Cefetamet pivoxil is a new ß lactamase orally stable administered cephalosporin. Antimicrobial resistance among

  13. Antimicrobial Peptides: Multifunctional Drugs for Different Applications

    Directory of Open Access Journals (Sweden)

    Lea-Jessica Albrecht

    2012-02-01

    Full Text Available Antimicrobial peptides (APs are an important part of the innate immune system in epithelial and non-epithelial surfaces. So far, many different antimicrobial peptides from various families have been discovered in non-vertebrates and vertebrates. They are characterized by antibiotic, antifungal and antiviral activities against a variety of microorganisms. In addition to their role as endogenous antimicrobials, APs participate in multiple aspects of immunity. They are involved in septic and non-septic inflammation, wound repair, angiogenesis, regulation of the adaptive immune system and in maintaining homeostasis. Due to those characteristics AP could play an important role in many practical applications. Limited therapeutic efficiency of current antimicrobial agents and the emerging resistance of pathogens require alternate antimicrobial drugs. The purpose of this review is to highlight recent literature on functions and mechanisms of APs. It also shows their current practical applications as peptide therapeutics and bioactive polymers and discusses the possibilities of future clinical developments.

  14. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... Veterinary Safety & Health Antimicrobial Resistance Animation of Antimicrobial Resistance Share Tweet Linkedin Pin it More sharing options ... produced a nine-minute animation explaining how antimicrobial resistance both emerges and proliferates among bacteria. Over time, ...

  15. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... how antimicrobial resistance both emerges and proliferates among bacteria. Over time, the use of antimicrobial drugs will result in the development of resistant strains of bacteria, complicating clinician's efforts to select the appropriate antimicrobial ...

  16. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... Animal & Veterinary Safety & Health Antimicrobial Resistance Animation of Antimicrobial Resistance Share Tweet Linkedin Pin it More sharing options ... CVM) produced a nine-minute animation explaining how antimicrobial resistance both emerges and proliferates among bacteria. Over time, ...

  17. Helical Antimicrobial Sulfono- {gamma} -AApeptides

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yaqiong; Wu, Haifan; Teng, Peng; Bai, Ge; Lin, Xiaoyang; Zuo, Xiaobing; Cao, Chuanhai; Cai, Jianfeng

    2015-06-11

    Host-defense peptides (HDPs) such as magainin 2 have emerged as potential therapeutic agents combating antibiotic resistance. Inspired by their structures and mechanism of action, herein we report the fi rst example of antimicrobial helical sulfono- γ - AApeptide foldamers. The lead molecule displays broad-spectrum and potent antimicrobial activity against multi-drug-resistant Gram- positive and Gram-negative bacterial pathogens. Time-kill studies and fl uorescence microscopy suggest that sulfono- γ -AApeptides eradicate bacteria by taking a mode of action analogous to that of HDPs. Clear structure - function relationships exist in the studied sequences. Longer sequences, presumably adopting more-de fi ned helical structures, are more potent than shorter ones. Interestingly, the sequence with less helical propensity in solution could be more selective than the stronger helix-forming sequences. Moreover, this class of antimicrobial agents are resistant to proteolytic degradation. These results may lead to the development of a new class of antimicrobial foldamers combating emerging antibiotic-resistant pathogens.

  18. Antimicrobial Polymers with Metal Nanoparticles

    Directory of Open Access Journals (Sweden)

    Humberto Palza

    2015-01-01

    Full Text Available Metals, such as copper and silver, can be extremely toxic to bacteria at exceptionally low concentrations. Because of this biocidal activity, metals have been widely used as antimicrobial agents in a multitude of applications related with agriculture, healthcare, and the industry in general. Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives. Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc. One recent route to further extend the antimicrobial applications of these metals is by their incorporation as nanoparticles into polymer matrices. These polymer/metal nanocomposites can be prepared by several routes such as in situ synthesis of the nanoparticle within a hydrogel or direct addition of the metal nanofiller into a thermoplastic matrix. The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms.

  19. Pyridinium Oxime Compounds as Antimicrobial Agents

    Science.gov (United States)

    2007-08-01

    requise pour supprimer la croissance microbienne de 50%) de 350 jiM contre B. cereus dans un riche milieu et de 80 pM contre B. anthracis Sterne dans...compkement d~pourvu de la capacit6 d’ernpfcher la croissance microbienne. Malgr-6 les hauts niveaux de serum r~alisables par ce compos6, l’oxime HI-6 n’aurait...U Defence Research and Recherche et d~veloppement 1 1 Development Canada pour la defense Canada DEFENCE DEFENSE Pyridiniumn Oxime Compounds as

  20. Bacteria‐Triggered Release of Antimicrobial Agents

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Chiang, Wen‐Chi; Tolker‐Nielsen, Tim

    2014-01-01

    Medical devices employed in healthcare practice are often susceptible to microbial contamination. Pathogenic bacteria may attach themselves to device surfaces of catheters or implants by formation of chemically complex biofilms, which may be the direct cause of device failure. Extracellular...... material is demonstrated by the bacteria‐triggered release of antibiotics to control bacterial populations and signaling molecules to modulate quorum sensing. The self‐regulating system provides the basis for the development of device‐relevant polymeric materials, which only release antibiotics...... in dependency of the titer of bacteria surrounding the medical device....

  1. Bacteria-Triggered Release of Antimicrobial Agents

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Chiang, Wen-Chi; Tolker-Nielsen, Tim

    2014-01-01

    Medical devices employed in healthcare practice are often susceptible to microbial contamination. Pathogenic bacteria may attach themselves to device surfaces of catheters or implants by formation of chemically complex biofilms, which may be the direct cause of device failure. Extracellular...... material is demonstrated by the bacteria‐triggered release of antibiotics to control bacterial populations and signaling molecules to modulate quorum sensing. The self‐regulating system provides the basis for the development of device‐relevant polymeric materials, which only release antibiotics...... in dependency of the titer of bacteria surrounding the medical device....

  2. Antimicrobial Pharmacokinetics and Pharmacodynamics in Older Adults.

    Science.gov (United States)

    Benson, John M

    2017-12-01

    Antimicrobial use in older adults requires working knowledge of the pharmacokinetics and pharmacodynamics of these drugs, and the alterations known to occur with these models as patients age. A summary of pharmacokinetic principles relevant to antimicrobials and an overview of published medical literature describing pharmacokinetic changes known to correlate with age are presented. Pharmacodynamic models that apply to antibacterial agents are reviewed, as are likely effects of aging on these models. The understanding of how older adults respond in terms of efficacy and toxicity is increasing but limited. Further research into the effects of aging on the actions of antimicrobials in the elderly is needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Antimicrobial commodities. part 2. Antimicrobial and odor-preventing fibers; Kokin seikatsu yohin ( 2 ). Kokin boshu sen`i

    Energy Technology Data Exchange (ETDEWEB)

    Yabe, N. [Toray Research Center Inc., Shiga (Japan)

    1998-05-01

    Demand for antimicrobial and order-preventing fibers is still expanding smoothly after a boom during a period from 1982 to 1985 owing to the great progress in its safety, manufacturing technology and evaluation of antimicrobial property. In this paper, the antimicrobial and odor-preventing fibers are described summarily. Main antimicrobial agents used in the antimicrobial and odor-preventing fibers hitherto are aromatic halogen compounds and organic silicon quaternary ammonium salts. In recent years, the kinds of antimicrobial agents are increased corresponding to the expansion of the demand for antimicrobial and odor-preventing fibers. Specifically, metals or inorganic particles containing metals; and quaternary ammonium salts or organic silicon quaternary ammonium salts are used frequently. Recently, the studies in respect to the utilization of chitin and chitosan are executed actively. Mainly employed processing method of the antimicrobial and odor-prevention fibers is a post processing by a working liquid containing kneaded fiber forming (mixed fiber forming) of antimicrobial inorganic particles such as metal powders or metal supporting zeolites; and an antimicrobial agent. 8 refs., 3 figs., 5 tabs.

  4. Evaluation of Origanum vulgare essential oil as antimicrobial agent in sausage Avaliação da atividade antimicrobiana de óleo essencial de Origanum vulgare em linguiça

    OpenAIRE

    Cassiano Busatta; Altemir José Mossi; Maria Regina Alves Rodrigues; Rogério Luis Cansian; José Vladimir de Oliveira

    2007-01-01

    This work reports antimicrobial activity of oregano (Origanum vulgare) essential oil against several bacteria in sausage. The in vitro minimum inhibitory concentration (MIC) was determined for 9 selected aerobic heterotrofic bacteria. The antimicrobial activity of distinct concentrations of the essential oil on the basis of the highest MIC found was tested in a food system comprised of fresh sausage. Batch food samples were also inoculated with Escherichia coli with a fixed concentration and ...

  5. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... More in Antimicrobial Resistance National Antimicrobial Resistance Monitoring System About NARMS 2015 NARMS Integrated Report Data Meetings and Publications Resources Judicious Use of ...

  6. Animation of Antimicrobial Resistance

    Medline Plus

    Full Text Available ... More in Antimicrobial Resistance National Antimicrobial Resistance Monitoring System ... If you need help accessing information in different file formats, see Instructions for Downloading ...

  7. Structural, physicochemical characterization and antimicrobial ...

    Indian Academy of Sciences (India)

    Abstract. Tetraaqua bismaleato iron(II) [Fe(C4H3O4)2(H2O)4], (1) is a new synthetic antimicrobial agent. Thermal analysis shows that the dehydration of the compound occurs in agreement with the structure. The sin- gle crystal salt crystallizes in the triclinic space group P-1 with a = 5.171(2) Å, b = 7.309(3) Å, c = 9.731(3).

  8. Structural, physicochemical characterization and antimicrobial ...

    Indian Academy of Sciences (India)

    Tetraaqua bismaleato iron(II) [Fe(C4H3O4)2 (H2O)4], (1) is a new synthetic antimicrobial agent. Thermal analysis shows that the dehydration of the compound occurs in agreement with the structure. The single crystal salt crystallizes in the triclinic space group -1 with = 5.171(2) Å, = 7.309(3) Å, = 9.731(3) Å, ...

  9. Sanguinarine: A Novel Agent Against Prostate Cancer

    National Research Council Canada - National Science Library

    Ahmad, Nihal

    2007-01-01

    ..., has been shown to possess anti-microbial, antioxidant and anti-inflammatory properties. Our earlier studies suggested that sanguinarine may be developed as an agent for the management of prostate cancer...

  10. Sanguinarine: A Novel Agent Against Prostate Cancer

    National Research Council Canada - National Science Library

    Ahmad, Nihal

    2008-01-01

    ..., has been shown to possess anti-microbial, antioxidant and anti-inflammatory properties. Our earlier studies suggested that sanguinarine may be developed as an agent for the management of prostate cancer...

  11. Antimicrobial Activities of Clove and Thyme Extracts

    Science.gov (United States)

    Nzeako, B C; Al-Kharousi, Zahra S N; Al-Mahrooqui, Zahra

    2006-01-01

    Objective: It has been postulated that geographical locations of the herbs affect the constituents of their essential oils and thus the degree of their antimicrobial action. This study examine two samples of clove obtained from Sri Lanka and Zanzibar and two samples of thyme from Iran and Oman to determine the antimicrobial potential of their extracted oils. Method: The active agents in each plant were extracted by steam distillation and by boiling. The antimicrobial activities of the extracts were determined at neat and by two-fold dilutions in well agar diffusion technique using Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Streptococcus pyogenes, Corynebacterium species, Salmonella species, Bacteroides fragilis and Candida albicans. Results: All oil extracts possessed antimicrobial activity against all bacteria and yeast tested. Their water extracts exhibited lower antimicrobial activity, though thyme aqueous extract was active only against S. aureus. The lowest concentration of antimicrobial activity (0.1% i.e., 1:1024) was obtained with thyme oil extract using Candida albicans. There was no significant difference in antimicrobial activity between clove obtained from Sri Lanka or Zanzibar or thyme obtained from Iran or Oman. Conclusion: Our experiment showed that the country of origin of the herbs has no effect on their antimicrobial activity. However, further work is necessary to ascertain why Candida albicans displayed remarkable degree of sensitivity with the extracts than all the other organisms test. PMID:21748125

  12. Antimicrobial activities of clove and thyme extracts.

    Science.gov (United States)

    Nzeako, B C; Al-Kharousi, Zahra S N; Al-Mahrooqui, Zahra

    2006-06-01

    It has been postulated that geographical locations of the herbs affect the constituents of their essential oils and thus the degree of their antimicrobial action. This study examine two samples of clove obtained from Sri Lanka and Zanzibar and two samples of thyme from Iran and Oman to determine the antimicrobial potential of their extracted oils. The active agents in each plant were extracted by steam distillation and by boiling. The antimicrobial activities of the extracts were determined at neat and by two-fold dilutions in well agar diffusion technique using Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Streptococcus pyogenes, Corynebacterium species, Salmonella species, Bacteroides fragilis and Candida albicans. All oil extracts possessed antimicrobial activity against all bacteria and yeast tested. Their water extracts exhibited lower antimicrobial activity, though thyme aqueous extract was active only against S. aureus. The lowest concentration of antimicrobial activity (0.1% i.e., 1:1024) was obtained with thyme oil extract using Candida albicans. There was no significant difference in antimicrobial activity between clove obtained from Sri Lanka or Zanzibar or thyme obtained from Iran or Oman. Our experiment showed that the country of origin of the herbs has no effect on their antimicrobial activity. However, further work is necessary to ascertain why Candida albicans displayed remarkable degree of sensitivity with the extracts than all the other organisms test.

  13. Antimicrobial susceptibility profiles of oral Treponema species.

    Science.gov (United States)

    Okamoto-Shibayama, Kazuko; Sekino, Jin; Yoshikawa, Kouki; Saito, Atsushi; Ishihara, Kazuyuki

    2017-12-01

    Treponemes occur in the microflora of the dental plaque. Certain Treponema species that are frequently isolated from chronic periodontitis lesions are involved in its initiation and progression. In addition to mechanical instrumentation, antimicrobial agents are used as an adjunctive treatment modality for periodontitis. Despite its importance for successful antimicrobial treatment, information about susceptibility is limited for Treponema species. The aim of this study was to assess the susceptibility of Treponema denticola strains, Treponema socranskii, and Treponema vincentii to eleven antimicrobial agents. The minimum inhibitory and minimum bactericidal concentrations of these antimicrobial agents revealed strain-specific variation. Doxycycline, minocycline, azithromycin, and erythromycin were effective against all Treponema species tested in this study, whereas fluoroquinolones only exhibited an equivalent effectiveness on T. socranskii. The susceptibility of one T. denticola strain, T. socranskii, and T. vincentii to kanamycin was influenced by prior exposure to aerobic conditions. The susceptibility to quinolone drugs varied among strains of T. denticola, although they share an amino acid sequence identity of greater than 99% for DNA gyrase (type II topoisomerase) subunit A. In addition, an ATP-binding cassette (ABC) transporter inhibitor assay for T. denticola indicated that the transport of quinolone drugs is partially related to this transporter, although there may be parallel transport mechanisms. Our results provide important insights into antimicrobial agent-Treponema dynamics and establish a basis for developing an appropriate adjunctive therapy for periodontal disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Spectrum of antimicrobial activity associated with ionic colloidal silver.

    Science.gov (United States)

    Morrill, Kira; May, Kathleen; Leek, Daniel; Langland, Nicole; Jeane, La Deana; Ventura, Jose; Skubisz, Corey; Scherer, Sean; Lopez, Eric; Crocker, Ephraim; Peters, Rachel; Oertle, John; Nguyen, Krystine; Just, Scott; Orian, Michael; Humphrey, Meaghan; Payne, David; Jacobs, Bertram; Waters, Robert; Langland, Jeffrey

    2013-03-01

    Silver has historically and extensively been used as a broad-spectrum antimicrobial agent. However, the Food and Drug Administration currently does not recognize colloidal silver as a safe and effective antimicrobial agent. The goal of this study was to further evaluate the antimicrobial efficacy of colloidal silver. Several strains of bacteria, fungi, and viruses were grown under multicycle growth conditions in the presence or absence of ionic colloidal silver in order to assess the antimicrobial activity. For bacteria grown under aerobic or anaerobic conditions, significant growth inhibition was observed, although multiple treatments were typically required. For fungal cultures, the effects of ionic colloidal silver varied significantly between different genera. No viral growth inhibition was observed with any strains tested. The study data support ionic colloidal silver as a broad-spectrum antimicrobial agent against aerobic and anaerobic bacteria, while having a more limited and specific spectrum of activity against fungi.

  15. Antimicrobial Resistance in Escherichia coli Isolates from Swine and Wild Small Mammals in the Proximity of Swine Farms and in Natural Environments in Ontario, Canada▿

    OpenAIRE

    Kozak, Gosia K.; Boerlin, Patrick; Janecko, Nicol; Reid-Smith, Richard J.; Jardine, Claire

    2008-01-01

    Wild animals not normally exposed to antimicrobial agents can acquire antimicrobial agent-resistant bacteria through contact with humans and domestic animals and through the environment. In this study we assessed the frequency of antimicrobial resistance in generic Escherichia coli isolates from wild small mammals (mice, voles, and shrews) and the effect of their habitat (farm or natural area) on antimicrobial resistance. Additionally, we compared the types and frequency of antimicrobial resi...

  16. antimicrobial susceptibility pattern of vibrio cholerae 01 strains

    African Journals Online (AJOL)

    hi-tech

    2000-07-07

    Jul 7, 2000 ... for the rapid rise in antimicrobial resistance have been extensive antimicrobial prophylaxis, unauthorised dispensing and use of these agents in animal husbandry(11,12). In Tanzania, data collected during cholera epidemics in 1990 and 1991 showed that all V. cholerae 01 strains were sensitive to ...

  17. Antimicrobial activity of Mucuna pruriens on selected bacteria ...

    African Journals Online (AJOL)

    ... negative and spore forming microorganisms and fungi. The methanol extract of M. pruriens showed broad-spectrum antimicrobial activity against all the tested microorganisms except Candida albicans. The results obtained in the study shows that M. pruriens extract can be a potential surce of natural antimicrobial agent.

  18. Polymeric Systems of Antimicrobial Peptides—Strategies and Potential Applications

    Directory of Open Access Journals (Sweden)

    Ewa Olędzka

    2013-11-01

    Full Text Available The past decade has seen growing interest in the investigation of peptides with antimicrobial activity (AMPs. One approach utilized in infection control is incorporation of antimicrobial agents conjugated with the polymers. This review presents the recent developments on polymeric AMP carriers and their potential applications in the biomedical and pharmaceutical fields.

  19. Antimicrobial activity of latex silver nanoparticles using Calotropis procera

    Directory of Open Access Journals (Sweden)

    Nadia Hussein Mohamed

    2014-11-01

    Conclusions: It can be concluded that serum latex of Calotropis procera was found to display strong potential for the synthesis of AgNPs as antimicrobial agents through rapid reduction of silver ions (Ag+ to Ag0. The green synthesized AgNPs were found to show higher antimicrobial efficacy than crude latex.

  20. Antimicrobial residues screening in pigs and goats slaughtered in ...

    African Journals Online (AJOL)

    Ekene Vivienne Ezenduka

    2012-07-17

    Jul 17, 2012 ... 2001; Pavlov et al., 2008). Antimicrobial use in food animals may result to residues in their products (meat, milk and egg) especially when the stipulated withdrawal period of the agent is not observed. This use of antimicrobial drugs in food animals has recently become a very important public health issue ...

  1. Antioxidant, antimicrobial and synergistic activities of tea polyphenols

    African Journals Online (AJOL)

    Microbial resistance to antibiotics has become an increasing global problem and there is a need to find out novel potent antimicrobial agents with alternative modes of action as accessories to antibiotic therapy. This study investigated the antioxidant, antimicrobial and synergistic properties of tea polyphenols. The tea ...

  2. Antimicrobial and Antioxidant Activities of the Stem Bark of Cussonia ...

    African Journals Online (AJOL)

    The results of this study justifies to some extent the use of C. bancoensis in the treatment of microbial infections and supports the ethnomedical evidence that the plant could be a potential source of natural antimicrobial and antioxidant agents. Keywords: Antimicrobial, antioxidant, phytochemical constituents, Cussonia ...

  3. Shigella Antimicrobial Drug Resistance Mechanisms, 2004-2014.

    Science.gov (United States)

    Nüesch-Inderbinen, Magdalena; Heini, Nicole; Zurfluh, Katrin; Althaus, Denise; Hächler, Herbert; Stephan, Roger

    2016-06-01

    To determine antimicrobial drug resistance mechanisms of Shigella spp., we analyzed 344 isolates collected in Switzerland during 2004-2014. Overall, 78.5% of isolates were multidrug resistant; 10.5% were ciprofloxacin resistant; and 2% harbored mph(A), a plasmid-mediated gene that confers reduced susceptibility to azithromycin, a last-resort antimicrobial agent for shigellosis.

  4. Antimicrobial activity of Monodora myristica seed oil | Odoh | Journal ...

    African Journals Online (AJOL)

    The essential oil is colourless, bitter with nice smell and the density is 0.789 g/ml. The oil had antimicrobial activity of the oil against Bacillus subtilis, Candida albicans and Staphylococcus aureus among the tested organism and can be incorporated into cream as antimicrobial agent and as a perfume. Key words: Monodora ...

  5. Plasmid profile and antimicrobial resistance ratings of enterococci ...

    African Journals Online (AJOL)

    Our aim was to isolate and investigate the resistance ratings of enterococci poultry and pig isolates to various antimicrobial agents as well as to determine their plasmid profiles. Antimicrobial resistance ratings and the plasmid profiles of Enterococci isolated from poultry birds and pigs were analyzed. Three hundred and ...

  6. Antimicrobial stewardship: attempting to preserve a strategic resource

    Directory of Open Access Journals (Sweden)

    Trevor Van Schooneveld, Md

    2011-07-01

    Full Text Available Antimicrobials hold a unique place in our drug armamentarium. Unfortunately the increase in resistance among both gram-positive and gram-negative pathogens coupled with a lack of new antimicrobial agents is threatening our ability to treat infections. Antimicrobial use is the driving force behind this rise in resistance and much of this use is suboptimal. Antimicrobial stewardship programs (ASP have been advocated as a strategy to improve antimicrobial use. The goals of ASP are to improve patient outcomes while minimizing toxicity and selection for resistant strains by assisting in the selection of the correct agent, right dose, and best duration. Two major strategies for ASP exist: restriction/pre-authorization that controls use at the time of ordering and audit and feedback that reviews ordered antimicrobials and makes suggestions for improvement. Both strategies have some limitations, but have been effective at achieving stewardship goals. Other supplemental strategies such as education, clinical prediction rules, biomarkers, clinical decision support software, and institutional guidelines have been effective at improving antimicrobial use. The most effective antimicrobial stewardship programs have employed multiple strategies to impact antimicrobial use. Using these strategies stewardship programs have been able to decrease antimicrobial use, the spread of resistant pathogens, the incidence of C. difficile infection, pharmacy costs, and improved patient outcomes.

  7. Use of antimicrobial growth promoters in food animals and Enterococcus faecium resistance to therapeutic antimicrobial drugs in Europe

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar; Aarestrup, Frank Møller; Jensen, Lars Bogø

    1999-01-01

    Supplementing animal feed with antimicrobial agents to enhance growth has been common practice for more than 30 years and is estimated to constitute more than half the total antimicrobial use worldwide. The potential public health consequences of this use have been debated; however, until recentl...

  8. Cytotoxicity and antimicrobial activity of Salvia officinalis L. flowers ...

    African Journals Online (AJOL)

    It exhibited antibacterial activities against Staphylococcus aureus, Bacillus stearothermophilus, Micrococcus luteus, Serratia mascences, Clostridium ... This work has revealed further potentials of S. officinalis L flowers as an antimicrobial agent, especially against P. aeruginosa which is resistant to some antibiotics.

  9. Retrospective evaluation of antimicrobial prescribing pattern in a ...

    African Journals Online (AJOL)

    This was followed by quinolones and cephalosporin. Ciprofloxacin and cephalexin were the most commonly prescribed quinolones and cephalosporins respectively. Gentamycin was ... Conclusion: Broad spectrum and older generation antibacterials were the predominantly utilized antimicrobials in this survey. Agents like ...

  10. Antimicrobial Activity of Bee Venom and Melittin against Borrelia burgdorferi

    OpenAIRE

    Kayla M. Socarras; Priyanka A. S. Theophilus; Jason P. Torres; Khusali Gupta; Eva Sapi

    2017-01-01

    Lyme disease is a tick-borne, multi-systemic disease, caused by the bacterium Borrelia burgdorferi. Though antibiotics are used as a primary treatment, relapse often occurs after the discontinuation of antimicrobial agents. The reason for relapse remains unknown, however previous studies suggest the possible presence of antibiotic resistant Borrelia round bodies, persisters and attached biofilm forms. Thus, there is an urgent need to find antimicrobial agents suitable to eliminate all known f...

  11. Synthetic biology platform technologies for antimicrobial applications.

    Science.gov (United States)

    Braff, Dana; Shis, David; Collins, James J

    2016-10-01

    The growing prevalence of antibiotic resistance calls for new approaches in the development of antimicrobial therapeutics. Likewise, improved diagnostic measures are essential in guiding the application of targeted therapies and preventing the evolution of therapeutic resistance. Discovery platforms are also needed to form new treatment strategies and identify novel antimicrobial agents. By applying engineering principles to molecular biology, synthetic biologists have developed platforms that improve upon, supplement, and will perhaps supplant traditional broad-spectrum antibiotics. Efforts in engineering bacteriophages and synthetic probiotics demonstrate targeted antimicrobial approaches that can be fine-tuned using synthetic biology-derived principles. Further, the development of paper-based, cell-free expression systems holds promise in promoting the clinical translation of molecular biology tools for diagnostic purposes. In this review, we highlight emerging synthetic biology platform technologies that are geared toward the generation of new antimicrobial therapies, diagnostics, and discovery channels. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Antimicrobial-Coated Granules for Disinfecting Water

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  13. Antimicrobial activity of some Iranian medicinal plants

    Directory of Open Access Journals (Sweden)

    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. .

  14. Antimicrobial consumption and resistance in five Gram-negative bacterial species in a hospital from 2003 to 2011.

    Science.gov (United States)

    Lee, Heng-Sim; Loh, Yue-Xia; Lee, Jen-Jain; Liu, Chang-Shee; Chu, Chishih

    2015-12-01

    The misuse of antimicrobial agents increases drug resistance in bacteria. The correlation between antimicrobial agent consumption and related resistance in the Gram-negative bacteria Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis was analyzed during the period 2003-2011. Among these five bacteria, overall E. coli and K. pneumoniae were more commonly isolated from bloodstream than the other species. Regarding Enterobacteriaceae, E. coli and K. pneumoniae showed annual increases of resistance to the tested antimicrobial agents; conversely, P. mirabilis exhibited reduced resistance to cefuroxime, ceftriaxone and cefepime. In contrast to the relatively low antimicrobial resistance in P. aeruginosa, A. baumannii revealed high resistance, which was over 85% resistant rate to the tested antimicrobial agents and over 80% carbapenem resistance in 2011. E. coli, K. pneumoniae, and P. mirabilis differed in development of antimicrobial resistance after consumption of the antimicrobial agents. K. pneumoniae developed resistance to all antimicrobial groups, whereas resistance in P. mirabilis was not related to any antimicrobial consumption. P. aeruginosa developed resistance to β-lactam antimicrobials and aminoglycosides, whereas A. baumanii developed resistance to carbapenems after their use. The development of antimicrobial resistance was related to antimicrobial agents and bacterial species. Copyright © 2014. Published by Elsevier B.V.

  15. Agents containing chlorhexidine in dentistry

    Directory of Open Access Journals (Sweden)

    Lebedeva S.N.

    2011-03-01

    Full Text Available Aclinical definition of the efficacy of chlorhexidine-containing means for reducing the risk of dental caries and gingivitis with plastic caps. Chlorhexidine is an effective antimicrobial agent for the formation of individual programs for the prevention of dental caries

  16. Synthesis, antimicrobial evaluation and QSAR studies of gallic acid derivatives

    Directory of Open Access Journals (Sweden)

    Anurag Khatkar

    2017-05-01

    Full Text Available A series of gallic acid derivatives (1–33 was synthesized and characterized by physicochemical and spectral means. The synthesized compounds were evaluated in vitro for their antimicrobial activity against different Gram positive and Gram negative bacterial and fungal strains by the tube dilution method. Results of antimicrobial screening indicated that compound 6 was the most active antimicrobial agent (pMICam = 1.92 μM/mL. The results of QSAR studies demonstrated that antibacterial, antifungal and overall antimicrobial activities of synthesized gallic acid derivatives were governed by the electronic parameters, cosmic total energy (Cos E. and nuclear energy (Nu. E..

  17. Biofilm disruption with rotating microrods enhances antimicrobial efficacy

    Science.gov (United States)

    Mair, Lamar O.; Nacev, Aleksandar; Hilaman, Ryan; Stepanov, Pavel Y.; Chowdhury, Sagar; Jafari, Sahar; Hausfeld, Jeffrey; Karlsson, Amy J.; Shirtliff, Mark E.; Shapiro, Benjamin; Weinberg, Irving N.

    2017-04-01

    Biofilms are a common and persistent cause of numerous illnesses. Compared to planktonic microbes, biofilm residing cells often demonstrate significant resistance to antimicrobial agents. Thus, methods for dislodging cells from the biofilm may increase the antimicrobial susceptibility of such cells, and serve as a mechanical means of increasing antimicrobial efficacy. Using Aspergillus fumigatus as a model microbe, we magnetically rotate microrods in and around biofilm. We show that such rods can improve the efficacy of antimicrobial Amphotericin B treatments in vitro. This work represents a first step in using kinetic magnetic particle therapy for disrupting fungal biofilms.

  18. Prospective approach to managing antimicrobial drug shortages.

    Science.gov (United States)

    Griffith, Milena M; Patel, Jean A; Sutton, Sarah H; Bolon, Maureen K; Esterly, John S; Gross, Alan E; Postelnick, Michael J; Zembower, Teresa R; Scheetz, Marc H

    2012-07-01

    Antimicrobial drug shortages continue to increase, with few new therapeutic options available. Nationally, proposals have been offered to alleviate drug shortages; however, these recommendations are unlikely to effect change in the near future. Thus, antimicrobial stewardship leaders in acute care hospitals must develop a prospective management strategy to lessen the impact of these shortages on patient care. Herein, we describe several resources available to aid professionals in antimicrobial stewardship and healthcare epidemiology to manage drug shortages. An effective approach should include prospectively tracking shortages and maximizing inventory by appropriately managing usage. Several tenets should underpin this management. Alternative agents should be rationally chosen before the inventory of the primary agent has reached zero, ethical considerations should be taken into account, and timely notification and communication with key stakeholders should occur throughout the prescribing and dispensing process.

  19. Antimicrobial activity of pomegranate peel extracts as affected by cultivar.

    Science.gov (United States)

    Rosas-Burgos, Ema C; Burgos-Hernández, Armando; Noguera-Artiaga, Luis; Kačániová, Miroslava; Hernández-García, Francisca; Cárdenas-López, José L; Carbonell-Barrachina, Ángel A

    2017-02-01

    Some studies have reported that different parts of the pomegranate fruit, especially the peel, may act as potential antimicrobial agents and thus might be proposed as a safe natural alternative to synthetic antimicrobial agents. The high tannin content, especially punicalagin, found in pomegranate extracts, has been reported as the main compound responsible for such antimicrobial activity. Because the pomegranate peel chemical composition may vary with the type of cultivar (sweet, sour-sweet and sour), pomegranates may also differ with respect to their antimicrobial capacity. The extract from PTO8 pomegranate cultivar peel had the highest antimicrobial activity, as well as the highest punicalagins (α and β) and ellagic acid concentrations. In the results obtained from both antibacterial and antifungal activity studies, the sour-sweet pomegranate cultivar PTO8 showed the best antimicrobial activity, and the highest ellagic acid concentrations. The results of the present study suggest that ellagic acid content has a significant influence on the antimicrobial activity of the pomegranate extracts investigated. The pomegranate peel of the PTO8 cultivar is a good source of antifungal and antibacterial compounds, and may represent an alternative to antimicrobial agents of synthetic origin. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  20. Chemical analysis of plasma-assisted antimicrobial treatment on cotton

    Science.gov (United States)

    Kan, C. W.; Lam, Y. L.; Yuen, C. W. M.; Luximon, A.; Lau, K. W.; Chen, K. S.

    2013-06-01

    This paper explores the use of plasma treatment as a pretreatment process to assist the application of antimicrobial process on cotton fabric with good functional effect. In this paper, antimicrobial finishing agent, Microfresh Liquid Formulation 9200-200 (MF), and a binder (polyurethane dispersion, Microban Liquid Formulation R10800-0, MB) will be used for treating the cotton fabric for improving the antimicrobial property and pre-treatment of cotton fabric by plasma under atmospheric pressure will be employed to improve loading of chemical agents. The chemical analysis of the treated cotton fabric will be conducted by Fourier transform Infrared Spectroscopy.