Sample records for plant antimicrobial agents

  1. Plant Products as Antimicrobial Agents

    PubMed Central

    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

  2. Plant Antimicrobial Peptides as Potential Anticancer Agents

    PubMed Central

    Guzmán-Rodríguez, Jaquelina Julia; López-Gómez, Rodolfo

    2015-01-01

    Antimicrobial peptides (AMPs) are part of the innate immune defense mechanism of many organisms and are promising candidates to treat infections caused by pathogenic bacteria to animals and humans. AMPs also display anticancer activities because of their ability to inactivate a wide range of cancer cells. Cancer remains a cause of high morbidity and mortality worldwide. Therefore, the development of methods for its control is desirable. Attractive alternatives include plant AMP thionins, defensins, and cyclotides, which have anticancer activities. Here, we provide an overview of plant AMPs anticancer activities, with an emphasis on their mode of action, their selectivity, and their efficacy. PMID:25815333

  3. Plant Antimicrobial Agents and Their Effects on Plant and Human Pathogens

    PubMed Central

    González-Lamothe, Rocío; Mitchell, Gabriel; Gattuso, Mariza; Diarra, Moussa S.; Malouin, François; Bouarab, Kamal

    2009-01-01

    To protect themselves, plants accumulate an armoury of antimicrobial secondary metabolites. Some metabolites represent constitutive chemical barriers to microbial attack (phytoanticipins) and others inducible antimicrobials (phytoalexins). They are extensively studied as promising plant and human disease-controlling agents. This review discusses the bioactivity of several phytoalexins and phytoanticipins defending plants against fungal and bacterial aggressors and those with antibacterial activities against pathogens affecting humans such as Pseudomonas aeruginosa and Staphylococcus aureus involved in respiratory infections of cystic fibrosis patients. The utility of plant products as “antibiotic potentiators” and “virulence attenuators” is also described as well as some biotechnological applications in phytoprotection. PMID:20111686

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

    PubMed

    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. PMID:24446991

  5. Medicinal plants and antimicrobial activity

    Microsoft Academic Search

    J. L. Ríos; M. C. Recio

    2005-01-01

    In the present paper, we analyze the past, present and future of medicinal plants, both as potential antimicrobial crude drugs as well as a source for natural compounds that act as new anti-infection agents. In the past few decades, the search for new anti-infection agents has occupied many research groups in the field of ethnopharmacology. When we reviewed the number

  6. Fluoroquinolone antimicrobial agents.

    PubMed Central

    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 drugs are bactericidal and potent in vitro against members of the family Enterobacteriaceae, Haemophilus spp., and Neisseria spp., have good activity against Pseudomonas aeruginosa and staphylococci, and (with several exceptions) are less potent against streptococci and have fair to poor activity against anaerobic species. Potency in vitro decreases in the presence of low pH, magnesium ions, or urine but is little affected by different media, increased inoculum, or serum. The effects of the drugs in combination with a beta-lactam or aminoglycoside are often additive, occasionally synergistic, and rarely antagonistic. The agents are orally absorbed, require at most twice-daily dosing, and achieve high concentrations in urine, feces, and kidney and good concentrations in lung, bone, prostate, and other tissues. The drugs are efficacious in treatment of a variety of bacterial infections, including uncomplicated and complicated urinary tract infections, bacterial gastroenteritis, and gonorrhea, and show promise for therapy of prostatitis, respiratory tract infections, osteomyelitis, and cutaneous infections, particularly when caused by aerobic gram-negative bacilli. Fluoroquinolones have also proved to be efficacious for prophylaxis against travelers' diarrhea and infection with gram-negative bacilli in neutropenic patients. The drugs are effective in eliminating carriage of Neisseria meningitidis. Patient tolerability appears acceptable, with gastrointestinal or central nervous system toxicities occurring most commonly, but only rarely necessitating discontinuance of therapy. In 17 of 18 prospective, randomized, double-blind comparisons with another agent or placebo, fluoroquinolones were tolerated as well as or better than the comparison regimen. Bacterial resistance has been uncommonly documented but occurs, most notably with P. aeruginosa and Staphylococcus aureus and occasionally other species for which the therapeutic ratio is less favorable. Fluoroquinolones offer an efficacious, well-tolerated, and cost-effective alternative to parenteral therapies of selected infections. PMID:2680058

  7. Investigational Antimicrobial Agents of 2013

    PubMed Central

    Pucci, Michael J.

    2013-01-01

    SUMMARY New antimicrobial agents are always needed to counteract the resistant pathogens that continue to be selected by current therapeutic regimens. This review provides a survey of known antimicrobial agents that were currently in clinical development in the fall of 2012 and spring of 2013. Data were collected from published literature primarily from 2010 to 2012, meeting abstracts (2011 to 2012), government websites, and company websites when appropriate. Compared to what was reported in previous surveys, a surprising number of new agents are currently in company pipelines, particularly in phase 3 clinical development. Familiar antibacterial classes of the quinolones, tetracyclines, oxazolidinones, glycopeptides, and cephalosporins are represented by entities with enhanced antimicrobial or pharmacological properties. More importantly, compounds of novel chemical structures targeting bacterial pathways not previously exploited are under development. Some of the most promising compounds include novel ?-lactamase inhibitor combinations that target many multidrug-resistant Gram-negative bacteria, a critical medical need. Although new antimicrobial agents will continue to be needed to address increasing antibiotic resistance, there are novel agents in development to tackle at least some of the more worrisome pathogens in the current nosocomial setting. PMID:24092856

  8. Ruthenium complexes as antimicrobial agents.

    PubMed

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

    2015-04-10

    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. PMID:25724019

  9. Secondary Metabolites from Plants Inhibiting ABC Transporters and Reversing Resistance of Cancer Cells and Microbes to Cytotoxic and Antimicrobial Agents

    PubMed Central

    Wink, Michael; Ashour, Mohamed L.; El-Readi, Mahmoud Zaki

    2012-01-01

    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 ATP-binding cassette (ABC) transporters, such as P-gp, which pump out lipophilic compounds that have entered a cell, (2) Activation of cytochrome p450 oxidases which can oxidize lipophilic agents to make them more hydrophilic and accessible for conjugation reaction with glucuronic acid, sulfate, or amino acids, and (3) Activation of glutathione transferase, which can conjugate xenobiotics. This review summarizes the evidence that secondary metabolites (SM) 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, multiple resistance-associated protein 1, and Breast cancer resistance protein 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 multidrug resistance, at least partially, of adapted and resistant cells. If these SM are applied in combination with a cytotoxic or antimicrobial agent, they may reverse resistance in a synergistic fashion. PMID:22536197

  10. Plant antimicrobial peptides.

    PubMed

    Nawrot, Robert; Barylski, Jakub; Nowicki, Grzegorz; Broniarczyk, Justyna; Buchwald, Waldemar; Go?dzicka-Józefiak, Anna

    2014-05-01

    Plant antimicrobial peptides (AMPs) are a component of barrier defense system of plants. They have been isolated from roots, seeds, flowers, stems, and leaves of a wide variety of species and have activities towards phytopathogens, as well as against bacteria pathogenic to humans. Thus, plant AMPs are considered as promising antibiotic compounds with important biotechnological applications. Plant AMPs are grouped into several families and share general features such as positive charge, the presence of disulfide bonds (which stabilize the structure), and the mechanism of action targeting outer membrane structures. PMID:24092498

  11. Antimicrobial Activities of the Essential Oils of Various Plants against Tomato Late Blight Disease Agent Phytophthora infestans

    Microsoft Academic Search

    E. Mine Soylu; Soner Soylu; Sener Kurt

    2006-01-01

    The aim of this study was to find an alternative to synthetic fungicides currently used in the control of devastating oomycete\\u000a pathogen Phytophthora infestans, causal agent of late blight disease of tomato. Antifungal activities of essential oils obtained from aerial parts of aromatic\\u000a plants such as oregano (Origanum syriacum var. bevanii), thyme (Thymbra spicata subsp. spicata), lavender (Lavandula stoechas subsp.

  12. Effect of antimicrobial agents on livestock waste emissions.

    PubMed

    Varel, V H; Miller, D N

    2000-06-01

    Various antimicrobial agents were evaluated with the purpose of reducing the microbial fermentation in stored cattle waste and the resulting odor emissions. Duplicate sealed 2-L flasks with 500 ml waste slurry, with and without antimicrobial inhibitors, were used to measure the production of short-chain volatile fatty acids, lactate, and total fermentation gas over 27-30 days. A combination of chlorhexidine diacetate (2 mM), iodoacetate (2 mM), and alpha-pinene (3.8 mM) reduced gas production 80% (1000 ml to 200 ml) and total volatile fatty acid production 50% (145 mM to 72 mM). Pinene had little antimicrobial effect; rather, it served as an effective masking agent, giving the waste a less offensive odor. A combination of chlorhexidine diacetate and the deaminase inhibitor, diphenyliodonium chloride (1.3 mM) had a similar effect in reducing short-chain volatile fatty acid production (145 mM to 80 mM). It is concluded that a combination of antimicrobial agents may be useful in controlling odor emissions and conserving organic matter in livestock wastes, therefore providing a potentially more useful byproduct waste when used as plant fertilizer. PMID:10827282

  13. Susceptibility of Genital Mycoplasmas to Antimicrobial Agents

    PubMed Central

    Braun, Peter; Klein, Jerome O.; Kass, Edward H.

    1970-01-01

    The susceptibility of 11 T-strains, 12 strains of Mycoplasma hominis, and a single strain of M. fermentans to 15 antimicrobial agents was determined by study of inhibition of metabolic activity in a broth dilution system. All three species were inhibited by tetracycline, chloramphenicol, streptomycin, gentamicin, and kanamycin, and were relatively resistant to cephalothin, cephaloridine, polymyxin, vancomycin, and ampicillin. Three antimicrobial agents had significant differential effects on these species. Erythromycin was more active against T-strains than against M. hominis or M. fermentans. Lincomycin, clindamycin, and nitrofurantoin had greater activity against M. hominis and M. fermentans than against T-strains. The activity of the drugs tested was generally uniform over a wide range of inocula. The effect of pH and the difference between minimal inhibiting and minimal mycoplasmacidal concentrations of the drugs tested were consistent with expectations based on the effects of these drugs on bacteria. PMID:4313312

  14. Mechanisms of biofilm resistance to antimicrobial agents

    Microsoft Academic Search

    Thien-Fah C. Mah; George A. O'Toole

    2001-01-01

    Biofilms are communities of microorganisms attached to a surface. It has become clear that biofilm-grown cells express properties distinct from planktonic cells, one of which is an increased resistance to antimicrobial agents. Recent work has indicated that slow growth and\\/or induction of an rpoS-mediated stress response could contribute to biocide resistance. The physical and\\/or chemical structure of exopolysaccharides or other

  15. Bdellovibrio bacteriovorus : A future antimicrobial agent?

    PubMed Central

    Harini, K.; Ajila, Vidya; Hegde, Shruthi

    2013-01-01

    Bdellovibrio and like organisms (BALOs) are small, predatory, Deltaproteobacteria that prey on other Gram-negative pathogens. Many authors have unfolded the possible use of BALOs as biological control agents in environmental as well as medical microbiological settings. They are found strongly associated with natural biofilms and recent studies have shown that effective predation occurs in these naturally occurring bacterial communities. Periodontal infections could also be an interesting target for the application of BALOs as biological Gram-negative bacteria and therefore potentially susceptible to BALOs antimicrobial agents. This proposition is based on the fact that almost all periodontal pathogens are predation. Accordingly, this review aims to present the evolution toward applying Bdellovibrio bacteriovorus as an antibacterial agent to deal with oral infections, general medical conditions, environmental and industrial issues. PMID:24554900

  16. Bdellovibrio bacteriovorus : A future antimicrobial agent?

    PubMed

    Harini, K; Ajila, Vidya; Hegde, Shruthi

    2013-11-01

    Bdellovibrio and like organisms (BALOs) are small, predatory, Deltaproteobacteria that prey on other Gram-negative pathogens. Many authors have unfolded the possible use of BALOs as biological control agents in environmental as well as medical microbiological settings. They are found strongly associated with natural biofilms and recent studies have shown that effective predation occurs in these naturally occurring bacterial communities. Periodontal infections could also be an interesting target for the application of BALOs as biological Gram-negative bacteria and therefore potentially susceptible to BALOs antimicrobial agents. This proposition is based on the fact that almost all periodontal pathogens are predation. Accordingly, this review aims to present the evolution toward applying Bdellovibrio bacteriovorus as an antibacterial agent to deal with oral infections, general medical conditions, environmental and industrial issues. PMID:24554900

  17. Discovery and development of new antimicrobial agents.

    PubMed Central

    Gootz, T D

    1990-01-01

    The unprecedented growth in the number of new antibiotics over the past two decades has been the result of extensive research efforts that have exploited the growing body of knowledge describing the interactions of antibiotics with their targets in bacterial cells. Information gained from one class of antimicrobial agents has often been used to advance the development of other classes. In the case of beta-lactams, information on structure-activity relationships gleaned from penicillins and cephalosporins was rapidly applied to the cephamycins, monobactams, penems, and carbapenems in order to discover broad-spectrum agents with markedly improved potency. These efforts have led to the introduction of many new antibiotics that demonstrate outstanding clinical efficacy and improved pharmacokinetics in humans. The current review discusses those factors that have influenced the rapid proliferation of new antimicrobial agents, including the discovery of new lead structures from natural products and the impact of bacterial resistance development in the clinical setting. The development process for a new antibiotic is discussed in detail, from the stage of early safety testing in animals through phase I, II, and III clinical trials. PMID:2404566

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

    Microsoft Academic Search

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

    2007-01-01

    There is cumulative resistance against antibiotics of many bacteria. Therefore, the development of new antiseptics and antimicrobial agents for the treatment of skin infections is of increasing interest. We have screened six plant extracts and isolated compounds for antimicrobial effects on bacteria and yeasts with dermatological relevance. The following plant extracts have been tested: Gentiana lutea, Harpagophytum procumbens, Boswellia serrata

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

    PubMed

    Zeitler, Benjamin; Herrera Diaz, Areli; Dangel, Alexandra; Thellmann, Martha; Meyer, Helge; Sattler, Michael; Lindermayr, Christian

    2013-01-01

    This work describes the de-novo design of peptides that inhibit a broad range of plant pathogens. Four structurally different groups of peptides were developed that differ in size and position of their charged and hydrophobic clusters and were assayed for their ability to inhibit bacterial growth and fungal spore germination. Several peptides are highly active at concentrations between 0,1 and 1 µg/ml against plant pathogenic bacteria, such as Pseudomonas syringae, Pectobacterium carotovorum, and Xanthomonas vesicatoria. Importantly, no hemolytic activity could be detected for these peptides at concentrations up to 200 µg/ml. Moreover, the peptides are also active after spraying on the plant surface demonstrating a possible way of application. In sum, our designed peptides represent new antimicrobial agents and with the increasing demand for antimicrobial compounds for production of "healthy" food, these peptides might serve as templates for novel antibacterial and antifungal agents. PMID:23951222

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

    Microsoft Academic Search

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

    2005-01-01

    Propionibacterium acnes and Staphylococcus epidermidis have been recognized as pus-forming bacteria triggering an inflammation in acne. The present study was conducted to evaluate antimicrobial activities of Thai medicinal plants against these etiologic agents of acne vulgaris. Crude extracts were tested for antimicrobial activities by disc diffusion and broth dilution methods. The results from the disc diffusion method showed that 13

  1. Antimicrobial susceptibility of Lactobacillus species isolated from commercial ethanol plants

    Microsoft Academic Search

    Kenneth M. Bischoff; Kelly A. Skinner-Nemec; Timothy D. Leathers

    2007-01-01

    Bacterial contamination of commercial fermentation cultures is a common and costly problem to the fuel ethanol industry. Antimicrobials\\u000a such as virginiamycin (VIR) and penicillin (PEN) are frequently used to control contamination but there are little data available\\u000a on the susceptibility of bacterial contaminants to these agents. A survey of bacterial contaminants from a wet-mill ethanol\\u000a plant with no history of

  2. Diphosphonium Ionic Liquids as Broad Spectrum Antimicrobial Agents

    PubMed Central

    O’Toole, George A.; Wathier, Michel; Zegans, Michael E.; Shanks, Robert M.Q.; Kowalski, Regis; Grinstaff, Mark W.

    2011-01-01

    Purpose One of the most disturbing trends in recent years is the growth of resistant strains of bacteria with the simultaneous dearth of new antimicrobial agents. Thus, new antimicrobial agents for use on the ocular surface are needed. Methods We synthesized a variety of ionic liquid compounds, which possess two positively charged phosphonium groups separated by ten methylene units in a “bola” type configuration. We tested these compounds for antimicrobial activity versus a variety of ocular pathogens, as well as their cytoxicity in vitro in a corneal cell line and in vivo in mice. Results The ionic liquid Di-Hex C10 demonstrated broad in vitro antimicrobial activity at the low micromolar concentrations versus Gram-negative and Gram-positive organisms, including methicillin-resistant Staphylococcus aureus strains, as well as ocular fungal pathogens. Treatment with Di-Hex C10 resulted in bacterial killing in as little as 15 minutes in vitro. Di-Hex C10 showed little cytotoxicity at 1 ?M versus a corneal epithelial cell line or at 10 ?M in a mouse corneal wound model. We also show that this bis-phosphonium ionic liquid structure is key, as a comparable mono phosphonium ionic liquid is cytotoxic to both bacteria and corneal epithelial cells. Conclusions Here we report the first use of dicationic bis-phosphonium ionic liquids as antimicrobial agents. Our data suggest that diphosphonium ionic liquids may represent a new class of broad-spectrum antimicrobial agents for use on the ocular surface. PMID:22236790

  3. Thioridazine: resurrection as an antimicrobial agent?

    PubMed Central

    Thanacoody, H K R

    2007-01-01

    The emergence of multiresistant bacterial strains and the continuing burden of infectious disease globally point to the urgent need for novel affordable antimicrobial drugs. Thioridazine is a phenothiazine antipsychotic drug with well-recognized antimicrobial activity, but this property has not been harnessed for clinical use as a result of its central nervous system and cardiac side-effects. The cardiotoxicity of thioridazine has recently been shown to be structurally specific at a molecular level, whereas its antimicrobial properties are shared by a number of phenothiazine analogues. This raises the possibility that its enantiomers or its inactive metabolite, the ring sulphoxide, may act as a lead compound in the future development of antimicrobial drugs to face the new challenges in infectious disease. PMID:17764469

  4. Antimicrobial Activity of Indigenous Medicinal Plants Against Enterococcus

    E-print Network

    Firestone, Jeremy

    Antimicrobial Activity of Indigenous Medicinal Plants Against Enterococcus faecalis By Daniel setting against the antibiotic-resistant pathogen, Enterococcus faecalis. This was accomplished by first. #12;Antimicrobial Activity of Indigenous Medicinal Plants Against Enterococcus faecalis Introduction

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

    PubMed Central

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

    2013-01-01

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

  6. Total phenolic content, antioxidant and antimicrobial activities of some medicinal plants.

    PubMed

    Sengul, Memnune; Yildiz, Hilal; Gungor, Neva; Cetin, Bulent; Eser, Zeynep; Ercisli, Sezai

    2009-01-01

    Crude extracts from Inula aucherana, Fumaria officinalis, Crocus sativus, Vicum album, Tribulus terestris, Polygonatum multiflorum, Alkanna tinctoria and Taraxacum officinale were screened for their in vitro antioxidant and antimicrobial properties. Total phenolic content of extracts from these plants were also determined. beta-carotene bleaching assay and Folin-Ciocalteu reagent were used to determine total antioxidant activity and total phenols of plant extracts. Antimicrobial activity was determined by using disk diffusion assay. Antioxidant activity and total phenolic content varied among plants used and Viscum album and Crocus sativus had the highest antioxidant (82.23%) and total phenolic content (42.29 mgGAE/g DW), respectively. The methanol extracts from Vicum album and Alkanna tinctoria showed antimicrobial activity against 9 out of 32 microorganisms, however extract from Inula aucherana showed antimicrobial activity against 15 out of 32 microorganisms. The results provided evidence that the studied plant might indeed be potential sources of natural antioxidant and antimicrobial agents. PMID:19168430

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

    PubMed

    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. PMID:19242391

  8. Mushrooms as possible antioxidant and antimicrobial agents.

    PubMed

    Kosani?, Marijana; Rankovi?, Branislav; Daši?, 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 ?g/mL which was similar or greater than the standard antioxidants, ascorbic acid (IC50 = 4.22 ?g/mL), BHA (IC50 = 6.42 ?g/mL) and ?-tocopherol (IC50 = 62.43 ?g/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

  9. Mushrooms as Possible Antioxidant and Antimicrobial Agents

    PubMed Central

    Kosani?, Marijana; Rankovi?, Branislav; Daši?, 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 ?g/mL which was similar or greater than the standard antioxidants, ascorbic acid (IC50 = 4.22 ?g/mL), BHA (IC50 = 6.42 ?g/mL) and ?-tocopherol (IC50 = 62.43 ?g/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

  10. Combating microbial resistance to antimicrobial agents through dosing regimen optimization

    E-print Network

    Nikolaou, Michael

    - 1 - Combating microbial resistance to antimicrobial agents through dosing regimen optimization College of Pharmacy Houston, TX 77030 vhtam@central.uh.edu #12;- 2 - Abstract Microbial resistance of resistant microbial populations is crucial. In this chapter we provide a comprehensive presentation of our

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

    PubMed Central

    Akhtar, Muammad Saeed; Imran, Muhammad Babar; Nadeem, Muhammad Afzal; Shahid, Abubaker

    2012-01-01

    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. PMID:22675369

  12. Chemerin Is an Antimicrobial Agent in Human Epidermis

    PubMed Central

    Banas, Magdalena; Zabieglo, Katarzyna; Kasetty, Gopinath; Kapinska-Mrowiecka, Monika; Borowczyk, Julia; Drukala, Justyna; Murzyn, Krzysztof; Zabel, Brian A.; Butcher, Eugene C.; Schroeder, Jens M.; Schmidtchen, Artur; Cichy, Joanna

    2013-01-01

    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 Val66-Pro85, which causes direct bacterial lysis. Therefore, chemerin is an antimicrobial agent in human skin. PMID:23527010

  13. New antimicrobial agents for methicillin-resistant Staphylococcus aureus.

    PubMed

    Kollef, Marin H

    2009-12-01

    In bacterial and fungal infections, optimal outcomes are obtained through the timely provision of adequate antimicrobial coverage in an initial anti-infective treatment regimen. However, selecting appropriate antimicrobial regimens to treat infections in the intensive care unit is challenging because of the expansion of antibiotic resistance. Multidrug anti-infective regimens are typically needed to adequately cover common important pathogens in ICUs. Here, we describe novel antibacterial agents in the late stages of clinical development that show potential for treating methicillin-resistant Staphylococcus aureus (MRSA) infections. These include the fifth-generation cephalosporins, ceftaroline and ceftobiprole; the glycopeptides, dalbavancin, oritavancin, and telavancin; and iclaprim. PMID:20001879

  14. The Role of Unregulated Sale and Dispensing of Antimicrobial Agents on the Development of Antimicrobial Resistance in Developing Countries

    Microsoft Academic Search

    Eric S. Mitema

    \\u000a Antimicrobial resistance has become a major medical and public health problem worldwide. This has been brought about by overuse\\u000a and\\/or misuse of these drugs especially in developing countries. The role of unregulated sale and dispensing of antimicrobial\\u000a agents on the development of resistance is presented in this chapter.\\u000a \\u000a \\u000a Developing countries use both branded and generic antimicrobial agents which include major

  15. Antimicrobial susceptibility of Leptospira isolates from dogs and rats to 12 antimicrobial agents.

    PubMed

    Suepaul, S M; Carrington, C; Campbell, M; Borde, G; Adesiyun, A A

    2015-03-01

    This study determined the antimicrobial susceptibilities of 67 isolates of Leptospira from dogs (suspect canine cases: n=7 and stray dogs: n=6) and rodents (n=54) in Trinidad to 12 antimicrobial agents using broth microdilution and macrodilution techniques. Commonly used antimicrobial agents such as the penicillin G and ceftriaxone had relatively low minimal inhibitory concentrations (MICs) while doxycycline displayed a relatively higher value but was still considered to be effective. While imipenem was the most effective with low MIC values in vitro, sulphamethoxazole-trimethoprim had the highest i.e. least effective. Based on these results, the drugs commonly used in the treatment of leptospirosis (penicillin G, penicillin-streptomycin, doxycycline and ceftriaxone) in both humans and animals in Trinidad appear to have similar MICs and MBCs in vitro when compared with published reports. The serovar of Leptospira spp. and in most cases the origin of the isolates did not significantly (P>0.05) influence their susceptibilities to the antimicrobial agents tested. PMID:25801249

  16. Systemic anti-microbial agents used in periodontal therapy

    PubMed Central

    Patil, Vishakha; Mali, Rohini; Mali, Amita

    2013-01-01

    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. PMID:23869120

  17. Antityrosinase and antimicrobial activities from Thai medicinal plants.

    PubMed

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

    2014-04-01

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

  18. Antimicrobial activity of some Indian medicinal plants.

    PubMed

    Dabur, Rajesh; Gupta, Amita; Mandal, T K; Singh, Desh Deepak; Bajpai, Vivek; Gurav, A M; Lavekar, G S

    2007-01-01

    The antimicrobial potential of seventy-seven extracts from twenty-four plants was screened against eight bacteria and four pathogenic fungi, using microbroth dilution assay. Lowest concentration of the extract, which inhibits any visual microbial growth after treatment with p-iodonitrotetrazolium violet, was considered to be minimum inhibitory concentration (MIC). Water extracts of Acacia nilotica, Justicia zelanica, Lantana camara and Saraca asoca exhibited good activity against all the bacteria tested and the MIC was recorded in range of 9.375-37.5 microg/ml and 75.0-300.0 microg/ml against the bacterial and fungal pathogens, respectively. The other extracts of Phyllanthus urinaria, Thevetia nerifolia, Jatropha gossypifolia Saraca asoca, Tamarindus indica, Aegle marmelos, Acacia nilotica, Chlorophytum borivilianum, Mangifera indica, Woodfordia fruticosa and Phyllanthus emblica showed antimicrobial activity in a range of 75-1200 microg/ml. PMID:20161895

  19. New antimicrobial agents on the horizon.

    PubMed

    Bush, Karen; Pucci, Michael J

    2011-12-01

    Antibiotic resistance issues necessitate the continued discovery and development of new antibacterial agents. Efforts are ongoing in two approaches to find new compounds that are effective against antibiotic-resistant pathogens. These efforts involve modification of existing classes including fluoroquinolones, tetracyclines, aminoglycosides, and ?-lactams and identification of inhibitors against previously unexploited antibacterial targets. Examples of both approaches are described here with emphasis on compounds in late pre-clinical or clinical stages of development. PMID:21798250

  20. Biologically Active and Antimicrobial Peptides from Plants

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-08-24

    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. PMID:24915323

  2. Bacterial cell wall compounds as promising targets of antimicrobial agents I. Antimicrobial peptides and lipopolyamines

    PubMed Central

    de Tejada, Guillermo Martinez; Sánchez-Gómez, Susana; Kowalski, Ina; Kaconis, Yani; Andrä, Jörg; Schürholz, Tobias; Hornef, Mathias; Dupont, Aline; Garidel, Patrick; Gutsmann, Thomas; David, Sunil A.; Brandenburg, Klaus

    2013-01-01

    The first barrier that an antimicrobial agent must overcome when interacting with its target is the microbial cell wall. In the case of Gram-negative bacteria, additional to the cytoplasmic membrane and the peptidoglycan layer, an outer membrane (OM) is the outermost barrier. The OM has an asymmetric distribution of the lipids with phospholipids and lipopolysaccharide (LPS) located in the inner and outer leaflets, respectively. In contrast, Gram-positive bacteria lack OM and possess a much thicker peptidoglycan layer compared to their Gram-negative counterparts. An additional class of amphiphiles exist in Gram-positives, the lipoteichoic acids (LTA), which may represent important structural components. These long molecules cross-bridge the entire cell envelope with their lipid component inserting into the outer leaflet of the cytoplasmic membrane and the teichoic acid portion penetrating into the peptidoglycan layer. Furthermore, both classes of bacteria have other important amphiphiles, such as lipoproteins, whose importance has become evident only recently. It is not known yet whether any of these amphiphilic components are able to stimulate the immune system under physiological conditions as constituents of intact bacteria. However, all of them have a very high pro-inflammatory activity when released from the cell. Such a release may take place through the interaction with the immune system, or with antibiotics (particularly with those targeting cell wall components), or simply by the bacterial division. Therefore, a given antimicrobial agent must ideally have a double character, namely, it must overcome the bacterial cell wall barrier, without inducing the liberation of the pro-inflammatory amphiphiles. Here, new data are presented which describe the development and use of membrane-active antimicrobial agents, in particular antimicrobial peptides (AMPs) and lipopolyamines. In this way, essential progress was achieved, in particular with respect to the inhibition of deleterious consequences of bacterial infections such as severe sepsis and septic shock. PMID:22664072

  3. Preliminary phytochemical screening and antimicrobial evaluation of three medicinal plants used in Nigeria.

    PubMed

    Baba, Haruna; Onanuga, Adebola

    2011-01-01

    Methanol extract of three Nigerian medicinal plants were screened for antimicrobial activity using modified Kirby-Bauer disc diffusion and agar dilution techniques to determine the diameters of zone of inhibition and minimum inhibitory concentrations (MIC) of the extracts respectively. The extract of each of the plants were tested against five clinical bacterial isolates comprising of two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumonia) organisms. All the extracts exhibited moderate to high level of antimicrobial activities against these microorganisms. Phytochemical screening of powdered plant material revealed the presence of some secondary metabolites such as alkaloids, saponins, tannins, anthraquinones and flavonoids. These Nigerian medicinal plants could be developed into cheap, safe and culturally acceptable standardized herbal products and may serve as a source of new molecules for broad-spectrum antimicrobial agents. PMID:22654215

  4. Effect of Two Cancer Chemotherapeutic Agents on the Antibacterial Activity of Three Antimicrobial Agents

    PubMed Central

    Moody, Marcia R.; Morris, Maureen J.; Young, Viola Mae; Moyé, Lemuel A.; Schimpff, Stephen C.; Wiernik, Peter H.

    1978-01-01

    Cancer chemotherapeutic agents and antibacterial antibiotics are often given concomitantly. Daunorubicin, cytosine arabinoside, and three antibiotics (gentamicin, amikacin, and ticarcillin) were tested individually and in combinations to determine their antimicrobial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. These cytotoxic agents are commonly employed in the therapy of acute nonlymphocytic leukemia for remission induction therapy, and these antimicrobial agents are used in infection therapy. The maximum concentrations of the two cytotoxic drugs were chosen to be twice the known peak plasma levels of commonly employed dosage schedules. Neither of the cancer chemotherapeutic agents, alone or in combination, demonstrated bactericidal activity at the levels tested. However, in the presence of these agents, the antimicrobial activity of gentamicin and amikacin, although not that of ticarcillin, was depressed for 11 of 15 K. pneumoniae strains and 8 of 15 P. aeruginosa strains, but for none of the strains of E. coli. This level of decreased activity occasionally resulted in a minimal inhibitory concentration of the tested aminoglycoside well above the standard serum levels. Daunorubicin was more likely to antagonize gentamicin than was cytosine arabinoside. PMID:103494

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

    PubMed Central

    Méndez-Samperio, Patricia

    2014-01-01

    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. PMID:25210467

  6. In Vitro Activity of 39 Antimicrobial Agents Against Treponema hyodysenteriae

    PubMed Central

    Kitai, Kazuhisa; Kashiwazaki, Mamoru; Adachi, Yoshikazu; Kume, Tsuneo; Arakawa, Akira

    1979-01-01

    The in vitro activities of 39 antimicrobial agents against 23 isolates of Treponema hyodysenteriae, the majority of which were field isolates, were determined by the agar dilution technique. Quinoxalines, pleuromutilin, nitroimidazoles, and nitrofuran were the most active. Their activities ranged from ?0.10 to 1.56 ?g/ml. Lincomycin, penicillins, chloramphenicol, tetracyclines, cephalosporins, three peptides (virginiamycin, thiopeptin, and bacitracin), and one aminoglycoside (gentamicin) exhibited intermediate levels of activity ranging from 0.39 to 50 ?g/ml. Four peptides (enduracidin, viomycin, bicyclomycin, and colistin), three aminoglycosides (kanamycin, streptomycin, and neomycin), polyene, and other agents, including novobiocin, vancomycin, rifampin, nalidixic acid, and p-arsanilic acid, displayed limited activities ranging from 12.5 to ?100 ?g/ml. Macrolides showed varying degrees of activity depending upon isolates. PMID:464566

  7. Hydrolysis kinetics and QSAR investigation of soft antimicrobial agents.

    PubMed

    Loftsson, Thorsteinn; Thorsteinsson, Thorsteinn; Másson, Már

    2005-06-01

    Quaternary ammonium surfactants, such as benzalkonium chloride and cetylpyridinium chloride, are commonly used as antibacterial agents for disinfectants and for general environmental sanitation, as well as in surfactants, penetration enhancers and preservatives in pharmaceutical and cosmetic formulations. However, these agents are known to cause various side-effects and toxic reactions that are believed to be associated with their chemical stability. Soft analogues of the long-chain quaternary ammonium compounds were synthesized according to the soft drug approach and their physicochemical properties investigated, such as their hydrolytic rate constant, surface activity and lipophilicity. Structure-activity studies showed that the antimicrobial activity of the compounds was strongly influenced by their lipophilicity and chemical stability, the activity increasing with increasing lipophilicity and stability. However, in soft drug design structure-activity relationships are combined with structure-inactivation relationships during the lead optimization. The safety index (SI) of compounds was defined as the hydrolytic rate constant divided by the minimum inhibitory concentration. The SI of the soft antibacterial agents was found to increase with increasing lipophilicity but optimum SI was obtained when their hydrolytic t1/2, at pH 6 and 60 degrees C, was about 11 h. Optimization of the soft antibacterial agents through SI optimization resulted in potent but chemically unstable quaternary ammonium antibacterial agents. PMID:15969926

  8. Risk Factors for Resistance to Antimicrobial Agents among Nursing Home Residents

    Microsoft Academic Search

    Mark B. Loeb; Sharon Craven; Allison J. McGeer; Andrew E. Simor; Suzanne F. Bradley; Donald E. Low; Maxine Armstrong-Evans; Lorraine A. Moss; Stephen D. Walter

    The authors prospectively collected data on exposure to antimicrobial agents and susceptibility patterns among all clinical isolates of bacteria taken from 9,156 residents of 50 nursing homes in Canada and the United States in 1998-1999. Exposure to antimicrobial agents was measured during the 10 weeks prior to detection of targeted resistant bacteria in residents and compared with antibiotic exposure during

  9. Susceptibility of Nocardia asteroides to 45 Antimicrobial Agents In Vitro

    PubMed Central

    Bach, Michael C.; Sabath, Leon D.; Finland, Maxwell

    1973-01-01

    A method for preparing uniformly dispersed cultures of Nocardia asteroides for use in tests for susceptibility to antimicrobial agents is described. The minimal inhibiting concentration (MIC) of 45 agents for cultures thus prepared was determined with the use of a replica-inoculating apparatus. Minocycline at a concentration of 3.1 ?g or less/ml inhibited 90% of the strains tested, and all were inhibited by 6.3 ?g/ml. An erythromycin concentration of 0.8 ?g or less/ml inhibited 40% of the strains, but the MIC for most of the others was > 100 ?g/ml. The other agents were generally less active. Chemically related analogues varied in activity to different degrees. Also, the MIC of each antibiotic against different strains generally varied over a wide range. Sulfonamides and trimethoprim were not active against most strains in the method used. The size of the inoculum markedly affected the MIC of sulfonamides and had variable effects on other agents. Marked synergy of erythromycin with ampicillin was demonstrated for nearly all strains tested. PMID:4597708

  10. Antimicrobial Activity of Seven Essential Oils From Iranian Aromatic Plants Against Common Causes of Oral Infections

    PubMed Central

    Zomorodian, Kamiar; Ghadiri, Pooria; Saharkhiz, Mohammad Jamal; Moein, Mohammad Reza; Mehriar, Peiman; Bahrani, Farideh; Golzar, Tahereh; Pakshir, Keyvan; Fani, Mohammad Mehdi

    2015-01-01

    Background: Over the past two decades, there has been a growing trend in using oral hygienic products originating from natural resources such as essential oils (EOs) and plant extracts. Seven aromatic plants used in this study are among popular traditional Iranian medicinal plants with potential application in modern medicine as anti-oral infectious diseases. Objectives: This study was conducted to determine the chemical composition and antimicrobial activities of essential oils from seven medicinal plants against pathogens causing oral infections. Materials and Methods: The chemical compositions of EOs distilled from seven plants were analyzed by gas chromatography/mass spectrometry (GC/MS). These plants included Satureja khuzestanica, S. bachtiarica, Ocimum sanctum, Artemisia sieberi, Zataria multiflora, Carum copticum and Oliveria decumbens. The antimicrobial activity of the essential oils was evaluated by broth micro-dilution in 96 well plates as recommended by the Clinical and Laboratory Standards Institute (CLSI) methods. Results: The tested EOs inhibited the growth of examined oral pathogens at concentrations of 0.015-16 µL/mL. Among the examined oral pathogens, Enterococcus faecalis had the highest Minimum Inhibitory Concentrations (MICs) and Minimum Microbicidal Concentrations (MMCs). Of the examined EOs, S. khuzestanica, Z. multiflora and S. bachtiarica, showed the highest antimicrobial activities, respectively, while Artemisia sieberi exhibited the lowest antimicrobial activity. Conclusions: The excellent antimicrobial activities of the tested EOs might be due to their major phenolic or alcoholic monoterpenes with known antimicrobial activities. Hence, these EOs can be possibly used as an antimicrobial agent in treatment and control of oral pathogens.

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

    PubMed

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

    2014-01-01

    Laboratory experiments were conducted to investigate the fate of the antimicrobial agent triclosan (TCS) in a conventional septic tank. The main mechanism of TCS removal from wastewater was identified to be rapid TCS sorption to suspended particles followed by settling of these particles to the bottom of the septic tank. Sorption to particles was completed within minutes while the settling took several days. Therefore, in a septic tank the removal of TCS from wastewater is mainly determined by the removal of suspended particles by sedimentation. Over 5 days of hydraulic residence time the initial dissolved TCS concentration of 100 ?g L(-1) was reduced by 87 ± 8%. During the first 24 hours, 66-86% of all removed TCS was retained, whereas during the remainder of the experiment a slight but steady decrease in TCS concentration was observed. This was most likely caused by TCS diffusion and its subsequent sorption onto the septic sludge. PMID:25116485

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

    PubMed Central

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

    2010-01-01

    Background: The stem barks are the rich sources of tannins and other phenolic compounds. Tannins inhibited the growth of various fungi, yeast, bacteria and virus. Hence, ten stem barks of ethnomedicinally important plants were screened for antibacterial and antifungal activities against human pathogenic strains. Methods: Air-dried and powdered stem bark of each plant was extracted with 50% aqueous ethanol, lyophilized and the dried crude extracts were used for the screening against 11 bacteria and 8 fungi. Antibacterial and antifungal activities were performed according to microdilution methods by NCCLS. Results: The plants Prosopis chilensis, Pithecellobium dulce, Mangifera indica showed significant antibacterial and antifungal activities against Streptococcus pneumonia, Enterobacter aerogenes, Klebsiella pneumonia and Candida albicans with MIC of 0.08mg/ml. Pithecellobium dulce bark also showed significant antibacterial activity against Bacillus cereus. Conclusion: The bark of Pithecellobium dulce has more or less similar activity against the known antibiotic and may be considered as potent antimicrobial agent for various infectious diseases. PMID:21808577

  13. Multidrug pump inhibitors uncover remarkable activity of plant antimicrobials.

    PubMed

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

    2002-10-01

    Plant antimicrobials are not used as systemic antibiotics at present. The main reason for this is their low level of activity, especially against gram-negative bacteria. The reported MIC is often in the range of 100 to 1,000 micro g/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. Major plant pathogens belong to the gram-negative bacteria, which makes the low level of activity of plant antimicrobials against this group of microorganisms puzzling. Gram-negative bacteria have an effective permeability barrier, comprised of the outer membrane, which restricts the penetration of amphipathic compounds, and multidrug resistance pumps (MDRs), which extrude toxins across this barrier. It is possible that the apparent ineffectiveness of plant antimicrobials is largely due to the permeability barrier. We tested this hypothesis in the present study by applying a combination of MDR mutants and MDR inhibitors. A panel of plant antimicrobials was tested by using a set of bacteria representing the main groups of plant pathogens. The human pathogens Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica serovar Typhimurium were also tested. The results show that the activities of the majority of plant antimicrobials were considerably greater against the gram-positive bacteria Staphylococcus aureus and Bacillus megaterium and that disabling of the MDRs in gram-negative species leads to a striking increase in antimicrobial activity. Thus, the activity of rhein, the principal antimicrobial from rhubarb, was potentiated 100- to 2,000-fold (depending on the bacterial species) by disabling the MDRs. Comparable potentiation of activity was observed with plumbagin, resveratrol, gossypol, coumestrol, and berberine. Direct measurement of the uptake of berberine, a model plant antimicrobial, confirmed that disabling of the MDRs strongly increases the level of penetration of berberine into the cells of gram-negative bacteria. These results suggest that plants might have developed means of delivering their antimicrobials into bacterial cells. These findings also suggest that plant antimicrobials might be developed into effective, broad-spectrum antibiotics in combination with inhibitors of MDRs. PMID:12234835

  14. Multidrug Pump Inhibitors Uncover Remarkable Activity of Plant Antimicrobials

    PubMed Central

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

    2002-01-01

    Plant antimicrobials are not used as systemic antibiotics at present. The main reason for this is their low level of activity, especially against gram-negative bacteria. The reported MIC is often in the range of 100 to 1,000 ?g/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. Major plant pathogens belong to the gram-negative bacteria, which makes the low level of activity of plant antimicrobials against this group of microorganisms puzzling. Gram-negative bacteria have an effective permeability barrier, comprised of the outer membrane, which restricts the penetration of amphipathic compounds, and multidrug resistance pumps (MDRs), which extrude toxins across this barrier. It is possible that the apparent ineffectiveness of plant antimicrobials is largely due to the permeability barrier. We tested this hypothesis in the present study by applying a combination of MDR mutants and MDR inhibitors. A panel of plant antimicrobials was tested by using a set of bacteria representing the main groups of plant pathogens. The human pathogens Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica serovar Typhimurium were also tested. The results show that the activities of the majority of plant antimicrobials were considerably greater against the gram-positive bacteria Staphylococcus aureus and Bacillus megaterium and that disabling of the MDRs in gram-negative species leads to a striking increase in antimicrobial activity. Thus, the activity of rhein, the principal antimicrobial from rhubarb, was potentiated 100- to 2,000-fold (depending on the bacterial species) by disabling the MDRs. Comparable potentiation of activity was observed with plumbagin, resveratrol, gossypol, coumestrol, and berberine. Direct measurement of the uptake of berberine, a model plant antimicrobial, confirmed that disabling of the MDRs strongly increases the level of penetration of berberine into the cells of gram-negative bacteria. These results suggest that plants might have developed means of delivering their antimicrobials into bacterial cells. These findings also suggest that plant antimicrobials might be developed into effective, broad-spectrum antibiotics in combination with inhibitors of MDRs. PMID:12234835

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

    PubMed

    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. PMID:17893761

  16. A Minimalist Design Approach to Antimicrobial Agents Based on a Thionin Template

    E-print Network

    Pompeu Fabra, Universitat

    A Minimalist Design Approach to Antimicrobial Agents Based on a Thionin Template Miquel Vila. Stabilization of secondary structure has been widely used in medicinal chemistry for the de novo design-hydrocarbon,3,14 or disulfide bonds.15,16 In this paper we describe how potent antimicrobial drug candidates

  17. Effect of Abolishment of the Use of Antimicrobial Agents for Growth Promotion on Occurrence of Antimicrobial Resistance in Fecal Enterococci from Food Animals in Denmark

    Microsoft Academic Search

    FRANK MØLLER AARESTRUP; ANNE METTE SEYFARTH; HANNE-DORTHE EMBORG; KARL PEDERSEN; R. S. Hendriksen; F. Bager

    2001-01-01

    From 1995 to 2000, a total of 673 Enterococcus faecium and 1,088 Enterococcus faecalis isolates from pigs together with 856 E. faecium isolates from broilers were isolated and tested for susceptibility to four classes of antimicrobial agents used for growth promotion as part of the Danish program of monitoring for antimicrobial resistance. The four antimicrobials were avilamycin, erythromycin, vancomycin, and

  18. Antimicrobial cyclic peptides for plant disease control.

    PubMed

    Lee, Dong Wan; Kim, Beom Seok

    2015-03-01

    Antimicrobial cyclic peptides derived from microbes bind stably with target sites, have a tolerance to hydrolysis by proteases, and a favorable degradability under field conditions, which make them an attractive proposition for use as agricultural fungicides. Antimicrobial cyclic peptides are classified according to the types of bonds within the ring structure; homodetic, heterodetic, and complex cyclic peptides, which in turn reflect diverse physicochemical features. Most antimicrobial cyclic peptides affect the integrity of the cell envelope. This is achieved through direct interaction with the cell membrane or disturbance of the cell wall and membrane component biosynthesis such as chitin, glucan, and sphingolipid. These are specific and selective targets providing reliable activity and safety for non-target organisms. Synthetic cyclic peptides produced through combinatorial chemistry offer an alternative approach to develop antimicrobials for agricultural uses. Those synthesized so far have been studied for antibacterial activity, however, the recent advancements in powerful technologies now promise to provide novel antimicrobial cyclic peptides that are yet to be discovered from natural resources. PMID:25774105

  19. Antimicrobial Cyclic Peptides for Plant Disease Control

    PubMed Central

    Lee, Dong Wan; Kim, Beom Seok

    2015-01-01

    Antimicrobial cyclic peptides derived from microbes bind stably with target sites, have a tolerance to hydrolysis by proteases, and a favorable degradability under field conditions, which make them an attractive proposition for use as agricultural fungicides. Antimicrobial cyclic peptides are classified according to the types of bonds within the ring structure; homodetic, heterodetic, and complex cyclic peptides, which in turn reflect diverse physicochemical features. Most antimicrobial cyclic peptides affect the integrity of the cell envelope. This is achieved through direct interaction with the cell membrane or disturbance of the cell wall and membrane component biosynthesis such as chitin, glucan, and sphingolipid. These are specific and selective targets providing reliable activity and safety for non-target organisms. Synthetic cyclic peptides produced through combinatorial chemistry offer an alternative approach to develop antimicrobials for agricultural uses. Those synthesized so far have been studied for antibacterial activity, however, the recent advancements in powerful technologies now promise to provide novel antimicrobial cyclic peptides that are yet to be discovered from natural resources. PMID:25774105

  20. Agent-Based Plant Growth Modeling

    Microsoft Academic Search

    Xiaoming Li; Zhongbin Su; Hongmin Sun; Ping Zheng

    2009-01-01

    Introducing Agent theory is an efficient way to solve the limitation of the method that constructing plant growth modeling in the virtual plant research, based on the definition and features of Agent and introduction of the virtual plant's significance and present situation. A new system of plant growth modeling is proposed, which is applied in soybean growth system, according to

  1. Antimicrobial peptides: agents of border protection for companion animals.

    PubMed

    Leonard, Brian C; Affolter, Verena K; Bevins, Charles L

    2012-06-01

    Over the past 20 years, there have been significant inroads into understanding the roles of antimicrobial peptides in homeostatic functions and their involvement in disease pathogenesis. In addition to direct antimicrobial activity, these peptides participate in many cellular functions, including chemotaxis, wound healing and even determination of canine coat colour. Various biological and genetic approaches have helped to elucidate the role of antimicrobial peptides with respect to innate immunity and host defense. Associations of antimicrobial peptides with various skin diseases, including psoriasis, rosacea and atopic dermatitis, have been documented in humans. In the longer term, therapeutic modulation of antimicrobial peptide expression may provide effective new treatments for disease. This review highlights current knowledge about antimicrobial peptides of the skin and circulating leukocytes, with particular focus on relevance to physiology and disease in companion animals. PMID:22409270

  2. Lauryl-poly-L-lysine: A New Antimicrobial Agent?

    PubMed Central

    Thuault, Véronique; Mangas, Arturo; Thienpont, Anne; Geffard, Michel

    2014-01-01

    The development of multiple antibiotic resistance is a global problem. It is necessary to find new tools whose mechanisms of action differ from those of currently used antibiotics. It is known that fatty acids and cationic polypeptides are able to fight bacteria. Here, we describe the synthesis of fatty acids linked to a polypeptide with antibacterial activity. The linkage of fatty acids to a polypeptide is reported to increase the antibacterial effect of the linked fatty acid in comparison with free fatty acids (FA) or free poly-L-lysine (PLL) or a mixture of both (FA free + PLL free). A number of C6–C18 fatty acids were linked to PLL to obtain new synthetic products. These compounds were assessed in vitro to evaluate their antibacterial activity. Some fatty acid-PLLs showed a good ability to fight bacteria. Their bactericidal activity was evaluated, and, lauryl linked to PLL was found to be the most active product against both Gram-positive and Gram-negative bacteria. This new active component showed a good degree of specificity and reproducibility and its minimum inhibitory concentration (MIC) was comparatively good. The antibacterial activity of the lauryl-PLL compound suggests that it is a new and promising antimicrobial agent. PMID:24660058

  3. Antimicrobial agent resistance in mycobacteria: molecular genetic insights.

    PubMed Central

    Musser, J M

    1995-01-01

    The primary theme emerging from molecular genetic work conducted with Mycobacterium tuberculosis and several other mycobacterial species is that resistance is commonly associated with simple nucleotide alterations in target chromosomal genes rather than with acquisition of new genetic elements encoding antibiotic-altering enzymes. Mutations in an 81-bp region of the gene (rpoB) encoding the beta subunit of RNA polymerase account for rifampin resistance in 96% of M. tuberculosis and many Mycobacterium leprae isolates. Streptomycin resistance in about one-half of M. tuberculosis isolates is associated with missense mutations in the rpsL gene coding for ribosomal protein S12 or nucleotide substitutions in the 16S rRNA gene (rrs). Mutations in the katG gene resulting in catalase-peroxidase amino acid alterations nad nucleotide substitutions in the presumed regulatory region of the inhA locus are repeatedly associated with isoniazid-resistant M. tuberculosis isolates. A majority of fluoroquinolone-resistant M. tuberculosis isolates have amino acid substitutions in a region of the DNA gyrase A subunit homologous to a conserved fluoroquinolone resistance-determining region. Multidrug-resistant isolates of M. tuberculosis arise as a consequence of sequential accumulation of mutations conferring resistance to single therapeutic agents. Molecular strategies show considerable promise for rapid detection of mutations associated with antimicrobial resistance. These approaches are now amenable to utilization in an appropriately equipped clinical microbiology laboratory. PMID:8665467

  4. Quantitative determination of infinite inhibition concentrations of antimicrobial agents.

    PubMed

    Marwan, A G; Nagel, C W

    1986-03-01

    We developed a method to determine the infinite inhibition concentrations (IICs) of antimicrobial agents. This method was based on finding the relative effectiveness of an inhibitor at various concentrations. Benzoic acid and parabens were tested on Saccharomyces bayanus, Hansenula sp., and Pseudomonas fluorescens. The relative effectiveness values of these compounds were established. A plot of the inhibitor concentration versus the reciprocal of relative effectiveness was linear. The chi-axis intercept was the concentration of the inhibitor which gave infinite microbial inhibition. For S. bayanus the IICs were 330, 930, 480, and 220 ppm (330, 930, 480, and 220 ml/liter) for benzoic acid and methyl-, ethyl-, and propylparabens, respectively. For Hansenula sp. the IIC was 180 ppm for benzoic acid. For P. fluorescens the IICs were 1,310, 960, and 670 ppm for methyl-, ethyl-, and propylparabens, respectively. Our results indicated that the IIC is affected by the growth medium. The advantages and applications of this method are discussed. PMID:3083773

  5. Evidence of an Association Between Use of Antimicrobial Agents in Food Animals and Antimicrobial Resistance Among Bacteria Isolated from Humans and the Human Health Consequences of Such Resistance

    Microsoft Academic Search

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

    2004-01-01

    Summary 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 Sal- monella and Campylobacter isolated from humans, but also appears likely among enterococci, Escherichia coli and other

  6. The dynamic observation of plasma concentration of antimicrobial agents during balanced ultrafiltration in vitro.

    PubMed

    Fang, Yinghui; Guan, Yulong; Wan, Caihong; Fu, Zhida; Jiang, Juanjuan; Wu, Chunfu; Zhao, Ju; Sun, Peng; Long, Cun

    2014-01-01

    Routine perioperative intravenous antimicrobial agents are administered as surgical prophylaxis. However, whether balanced ultrafiltration during extracorporeal circulation has substantial effect on the concentration of antimicrobial agents remains unclear. The concentrations of antimicrobial agents in plasma and ultrafiltrate samples were measured in this pseudo-extracorporeal circulation model. Extracorporeal circulation consisted of cardiotomy reservoir, membrane oxygenator, and pediatric arterial line filter. A hemoconcentrator was placed between the arterial purge line and oxygenator venous reservoir. Fresh donor human whole blood was added into the circuit and mixed with Ringer's solution to obtain a final hematocrit of 24-28%. Two kinds of antimicrobial agents, cefotiam (320?mg) and cefmetazole (160?mg), were bolus added into the circuit. After 30?min of extracorporeal circulation, zero-balanced ultrafiltration was initiated and arterial line pressure was maintained at approximately 100?mm?Hg with a Hoffman clamp. The rate of ultrafiltration (12?mL/min) was controlled by ultrafiltrate outlet pressure. An identical volume of Plasmalyte A was dripped into the circuit to maintain stable hematocrit during 45?min of experiment. Plasma and ultrafiltrate samples were drawn every 5?min, and concentrations of antimicrobial agents (including cefotiam and cefmetazole) were measured with high performance liquid chromatography. Both antimicrobial agents were detected in ultrafiltrate, demonstrating hemoconcentration may remove antimicrobial agents. The concentrations of plasma antimicrobial agents decreased linearly with the increase of ultrafiltrate volume. At end of balanced ultrafiltration, the concentration of plasma cefotiam was 104.96?±?44.36?mg/L, which is about 44.38%?±?7.42% of the initial concentration (238.95?±?101.12?mg/L) (P?antimicrobial agents from plasma and has a prominent influence on plasma concentration of antimicrobial agent. The strategy of surgical prophylaxis should consider this unique technique during extracorporeal circulation. PMID:23865445

  7. Antimicrobial and phytochemical studies on 45 Indian medicinal plants against multi-drug resistant human pathogens

    Microsoft Academic Search

    Iqbal Ahmad; Arina Z. Beg

    2001-01-01

    Ethanolic extracts of 45 Indian medicinal plants traditionally used in medicine were studied for their antimicrobial activity against certain drug-resistant bacteria and a yeast Candida albicans of clinical origin. Of these, 40 plant extracts showed varied levels of antimicrobial activity against one or more test bacteria. Anticandidal activity was detected in 24 plant extracts. Overall, broad-spectrum antimicrobial activity was observed

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

    PubMed Central

    Cecere, Manuel; Skaltsounis, Alexios Leandros; Argyropoulou, Aikaterini; Hellwig, Elmar; Aligiannis, Nektarios

    2014-01-01

    Nature is an unexplored reservoir of novel phytopharmaceuticals. Since biofilm-related oral diseases often correlate with antibiotic resistance, plant-derived antimicrobial agents could enhance existing treatment options. Therefore, the rationale of the present report was to examine the antimicrobial impact of Mediterranean natural extracts on oral microorganisms. Five different extracts from Olea europaea, mastic gum, and Inula viscosa were tested against ten bacteria and one Candida albicans strain. The extraction protocols were conducted according to established experimental procedures. Two antimicrobial assays—the minimum inhibitory concentration (MIC) assay and the minimum bactericidal concentration (MBC) assay—were applied. The screened extracts were found to be active against each of the tested microorganisms. O. europaea presented MIC and MBC ranges of 0.07–10.00?mg?mL?1 and 0.60–10.00?mg?mL?1, respectively. The mean MBC values for mastic gum and I. viscosa were 0.07–10.00?mg?mL?1 and 0.15–10.00?mg?mL?1, respectively. Extracts were less effective against C. albicans and exerted bactericidal effects at a concentration range of 0.07–5.00?mg?mL?1 on strict anaerobic bacteria (Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Parvimonas micra). Ethyl acetate I. viscosa extract and total mastic extract showed considerable antimicrobial activity against oral microorganisms and could therefore be considered as alternative natural anti-infectious agents. PMID:25054150

  9. Screening of some Cuban medicinal plants for antimicrobial activity

    Microsoft Academic Search

    M. J. Martínez; J. Betancourt; N. Alonso-González; A. Jauregui

    1996-01-01

    The antimicrobial activities of 23 extracts of 12 Cuban plant species reported in traditional medicine were tested. The agar diffusion method was used to assess the activity against four bacteria and one yeast: Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The results, evaluated as the diameter of the inhibition zone of microbial growth, showed that nine

  10. Antimicrobial activity of the essential oils of Turkish plant spices

    Microsoft Academic Search

    M. Özcan; Osman Erkmen

    2001-01-01

    The antimicrobial activity of the essential oils of nine plant spices (savory, laurel, oregano, basil, cumin, seafennel, myrtle, pickling herb, and mint) were tested at three concentrations (1, 10, and 15%) and tested on various microorganisms (Salmonella typhimurium, Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Yersinia enterocolitica, Saccharomyces cerevisiae, Candida rugosa, Rhizopus oryzae and Aspergillus niger). The results showed

  11. Bacterial resistance to antimicrobial agents used in fish farming: A critical evaluation of method and meaning

    Microsoft Academic Search

    Peter Smith; Maura Hiney; Ole Samuelsen

    1994-01-01

    The use of antimicrobial agents in aquaculture has resulted in the increase in the frequency of strains resistant to these agents. Potentially these resistant strains can have an impact on the therapy of fish diseases, the therapy of human diseases or the environment of the fish farms. The analysis of the extent of these impacts is hindered by the limited

  12. In vitro susceptibility testing of nonsporing anaerobes to ten antimicrobial agents.

    PubMed

    Rao, P S; Shivananda, P G

    2000-07-01

    Antibiotic susceptibility was performed on sixty clinical isolates of nonsporing anaerobes against ten antimicrobial agents. The test was performed on Muller Hinton Agar and Wilkins Chalgren blood agar by preparing suspension of freshly isolated colonies in BHI broth. Apart from Metronidazole and Chloramphenicol newer antibiotics like Minocycline, Secnidazole, Tinidazole, Clarithromycin, Roxithromycin were also tried. Antimicrobial agents like Metronidazole, Secnidazole, Tinidazole and Minocycline were 100% sensitive, followed by Chloramphenicol, Clarithromycin and Roxithromycin. These newer agents can be good alternatives for the treatment of non sporing anaerobes. PMID:11218673

  13. Pharmacokinetics and the dosage regimen of antimicrobial agents

    E-print Network

    Paris-Sud XI, Université de

    , France) Summary― Some consider antimicrobial therapy an art rather than a science. The drug that antimicrobial therapy is more of an art than a science. It is our be- lief that there are more failures due être considérée comme un art plutôt qu une science. La concentration en médicament au site de l

  14. Multidrug Pump Inhibitors Uncover Remarkable Activity of Plant Antimicrobials

    Microsoft Academic Search

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

    2002-01-01

    Plant antimicrobials are not used as systemic antibiotics at present. The main reason for this is their low level of activity, especially against gram-negative bacteria. The reported MIC is often in the range of 100 to 1,000 g\\/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. Major plant pathogens belong to the gram-negative bacteria,

  15. Isolation and Characterization of Antimicrobial Compounds in Plant Extracts against Multidrug-Resistant Acinetobacter baumannii

    PubMed Central

    Miyasaki, Yoko; Rabenstein, John D.; Rhea, Joshua; Crouch, Marie-Laure; Mocek, Ulla M.; Kittell, Patricia Emmett; Morgan, Margie A.; Nichols, Wesley Stephen; Van Benschoten, M. M.; Hardy, William David; Liu, George Y.

    2013-01-01

    The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant Acinetobacter baumannii (A. baumannii) is extremely limited. Magnolia officinalis, Mahonia bealei, Rabdosia rubescens, Rosa rugosa, Rubus chingii, Scutellaria baicalensis, and Terminalia chebula plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of A. baumannii. In this study, the compounds responsible for their antimicrobial activity were identified by fractionating each plant extract using high performance liquid chromatography, and determining the antimicrobial activity of each fraction against A. baumannii. The chemical structures of the fractions inhibiting >40% of the bacterial growth were elucidated by liquid chromatography/mass spectrometry analysis and nuclear magnetic resonance spectroscopy. The six most active compounds were identified as: ellagic acid in Rosa rugosa; norwogonin in Scutellaria baicalensis; and chebulagic acid, chebulinic acid, corilagin, and terchebulin in Terminalia chebula. The most potent compound was identified as norwogonin with a minimum inhibitory concentration of 128 µg/mL, and minimum bactericidal concentration of 256 µg/mL against clinically relevant strains of A. baumannii. Combination studies of norwogonin with ten anti-Gram negative bacterial agents demonstrated that norwogonin did not enhance the antimicrobial activity of the synthetic antibiotics chosen for this study. In conclusion, of all identified antimicrobial compounds, norwogonin was the most potent against multidrug-resistant A. baumannii strains. Further studies are warranted to ascertain the prophylactic and therapeutic potential of norwogonin for infections due to multidrug-resistant A. baumannii. PMID:23630600

  16. Collagen Patches Impregnated with Antimicrobial Agents Have High Local Antimicrobial Efficacy and Achieve Effective Tissue Gluing

    Microsoft Academic Search

    S. Baar; C. Schörner; M. Röllinghoff; M. Radespiel-Tröger; H. P. Hümmer; R. T. Carbon

    2001-01-01

    Background: Local antimicrobial systems have gained importance, as illustrated by current, research on drug delivery systems (DDS). We\\u000a aimed to develop materials that combine hemostatic and antimicrobial efficacy as well as adhesiveness for use in surgical\\u000a tissue management.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and Methods: Materials were evaluated by in vitro studies employing microbiological and technological methods.\\u000a \\u000a \\u000a \\u000a \\u000a Results: Antimicrobial impregnation of a collagen fleece,

  17. Antimicrobial activity of certain Indian medicinal plants used in folkloric medicine

    Microsoft Academic Search

    D. Srinivasan; Sangeetha Nathan; T. Suresh; P. Lakshmana Perumalsamy

    2001-01-01

    Fifty medicinal plants belonging to 26 families were studied for their antimicrobial activity. Among 50 plants tested, 72% showed antimicrobial activity. About 22 plant extracts from 15 families exhibited activity against both Gram-positive and Gram-negative bacteria. Fourteen plants belonging to 11 families did not show activity against any of the bacteria tested. Only nine plant extracts showed antifungal activity. The

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

    PubMed

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

    2007-08-01

    There is cumulative resistance against antibiotics of many bacteria. Therefore, the development of new antiseptics and antimicrobial agents for the treatment of skin infections is of increasing interest. We have screened six plant extracts and isolated compounds for antimicrobial effects on bacteria and yeasts with dermatological relevance. The following plant extracts have been tested: Gentiana lutea, Harpagophytum procumbens, Boswellia serrata (dry extracts), Usnea barbata, Rosmarinus officinalis and Salvia officinalis (supercritical carbon dioxide [CO2] extracts). Additionally, the following characteristic plant substances were tested: usnic acid, carnosol, carnosic acid, ursolic acid, oleanolic acid, harpagoside, boswellic acid and gentiopicroside. The extracts and compounds were tested against 29 aerobic and anaerobic bacteria and yeasts in the agar dilution test. U. barbata-extract and usnic acid were the most active compounds, especially in anaerobic bacteria. Usnea CO2-extract effectively inhibited the growth of several Gram-positive bacteria like Staphylococcus aureus (including methicillin-resistant strains - MRSA), Propionibacterium acnes and Corynebacterium species. Growth of the dimorphic yeast Malassezia furfur was also inhibited by Usnea-extract. Besides the Usnea-extract, Rosmarinus-, Salvia-, Boswellia- and Harpagophytum-extracts proved to be effective against a panel of bacteria. It is concluded that due to their antimicrobial effects some of the plant extracts may be used for the topical treatment of skin disorders like acne vulgaris and seborrhoic eczema. PMID:17291738

  19. Novel natural food antimicrobials.

    PubMed

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

    2012-01-01

    Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry. PMID:22385168

  20. Antimicrobial and cytotoxic activities of some crude drug extracts from Mexican medicinal plants.

    PubMed

    Gutierrez-Lugo, M T; Barrientos-Benítez, T; Luna, B; Ramirez-Gama, R M; Bye, R; Linares, E; Mata, R

    1996-03-01

    31 crude extracts derived from 28 plants highly valued as anti-infective agents in Mexican folk medicine have been screened for antimicrobial activity against four bacteria, a yeast and two molds. The results of the quantitative study indicated that the extracts derived from five species (Malmea depressa, Heliopsis longipes, Datura lanosa, Cnidosculus tehuacanensis and Helianthella quinquenervis) possessed significant antiseptic properties, therefore supporting the ethnomedical uses of these species. The cytotoxic activity was assayed against three cell lines HT-29 (Colon adenocarcinoma), MCF-7 (Breast carcinoma), A-549 (Lung carcinoma) and only the extract of Helianthella quinquenervis possessed significant activity against the MCF-7 cell line. PMID:23194772

  1. Pectin functionalized with natural fatty acids as antimicrobial agent.

    PubMed

    Calce, Enrica; Mignogna, Eleonora; Bugatti, Valeria; Galdiero, Massimiliano; Vittoria, Vittoria; De Luca, Stefania

    2014-07-01

    Several pectin derivatives were prepared by chemical modifications of the polysaccharide with natural fatty acids. The obtained biodegradable pectin-based materials, pectin-linoleate, pectin-oleate and pectin-palmitate, were investigated for their antimicrobial activity against several bacterial strains, Staphylococcus aureus and Escherichia coli. Good results were obtained for pectin-oleate and pectin-linoleate, which inhibit the growth of the selected microorganisms by 50-70%. They exert the better antimicrobial activity against S. aureus. Subsequently, the pectin-oleate and the pectin-linoleate samples were coated on polyethylene films and were assessed for their capacity to capture the oxygen molecules, reducing its penetration into the polymeric support. These results confirmed a possible application of the new materials in the field of active food packaging. PMID:24751510

  2. The potential of nitric oxide releasing therapies as antimicrobial agents

    PubMed Central

    Schairer, David O.; Chouake, Jason S.; Nosanchuk, Joshua D.; Friedman, Adam J.

    2012-01-01

    Nitric oxide (NO) is a short-lived, diatomic, lipophilic gas that plays an integral role in defending against pathogens. Among its many functions are involvement in immune cell signaling and in the biochemical reactions by which immune cells defend against bacteria, fungi, viruses and parasites. NO signaling directs a broad spectrum of processes, including the differentiation, proliferation, and apoptosis of immune cells. When secreted by activated immune cells, NO diffuses across cellular membranes and exacts nitrosative and oxidative damage on invading pathogens. These observations led to the development of NO delivery systems that can harness the antimicrobial properties of this evanescent gas. The innate microbicidal properties of NO, as well as the antimicrobial activity of the various NO delivery systems, are reviewed. PMID:22546899

  3. Susceptibility of Bifidobacteria of Animal Origin to Selected Antimicrobial Agents

    PubMed Central

    Mayrhofer, Sigrid; Mair, Christiane; Kneifel, Wolfgang; Domig, Konrad J.

    2011-01-01

    Strains of the genus Bifidobacterium are frequently used as probiotics, for which the absence of acquired antimicrobial resistance has become an important safety criterion. This clarifies the need for antibiotic susceptibility data for bifidobacteria. Based on a recently published standard for antimicrobial susceptibility testing of bifidobacteria with broth microdilution method, the range of susceptibility to selected antibiotics in 117 animal bifidobacterial strains was examined. Narrow unimodal MIC distributions either situated at the low-end (chloramphenicol, linezolid, and quinupristin/dalfopristin) or high-end (kanamycin, neomycin) concentration range could be detected. In contrast, the MIC distribution of trimethoprim was multimodal. Data derived from this study can be used as a basis for reviewing or verifying present microbiological breakpoints suggested by regulatory agencies to assess the safety of these micro-organisms intended for the use in probiotics. PMID:22312561

  4. Hypothiocyanite ion: detection of the antimicrobial agent in human saliva.

    PubMed

    Thomas, E L; Bates, K P; Jefferson, M M

    1980-09-01

    The median concentration of hypothiocyanite (OSCN-) in freshly collected whole saliva was 10 microM. The OSCN- concentration increased to a median value of 36 microM during incubation for one h at 37 degrees in vitro. This increase was partially inhibited by adding certain sugars (especially sucrose). The results suggest that OSCN- is a naturally occurring component of human saliva. Also, dietary carbohydrate may inhibit OSCN- accumulation and antimicrobial action in saliva. PMID:6931123

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

    PubMed

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

    2013-04-01

    As functionalized chitosans hold great potential for the development of effective and broad-spectrum antibiotics, representative chitosan derivatives were tested for antimicrobial activity in neutral media: trimethyl chitosan (TMC), carboxy-methyl chitosan (CMC), and chitosan-thioglycolic acid (TGA; medium molecular weight: MMW-TGA; low molecular weight: LMW-TGA). Colony forming assays indicated that LMW-TGA displayed superior antimicrobial activity over the other derivatives tested: a 30 min incubation killed 100% Streptococcus sobrinus (Gram-positive bacteria) and reduced colony counts by 99.99% in Neisseria subflava (Gram-negative bacteria) and 99.97% in Candida albicans (fungi). To elucidate LMW-TGA effects at the cellular level, microscopic studies were performed. Use of fluorescein isothiocyanate (FITC)-labeled chitosan derivates in confocal microscopy showed that LMW-TGA attaches to microbial cell walls, while transmission electron microscopy indicated that this derivative severely affects cell wall integrity and intracellular ultrastructure in all species tested. We therefore propose LMW-TGA as a promising and effective broad-band antimicrobial compound. PMID:23470196

  6. Antimicrobial Activity of Some Essential Oils Against Paenibacillus larvae, the Causal Agent of American Foulbrood Disease

    Microsoft Academic Search

    Adriana M. Alippi; Jorge A. Ringuelet; Elsa L. Cerimele; María S. Re; Cynthia P. Henning

    1996-01-01

    Essential oils from savory (Satureja hortensis), lavandin (Lavandula hybrida), eucalyptus (Eucalyptus globulus), lemon grass (Cymbopogon citratus), peppermint (Mentha × piperita), oregano (Origanum vulgare), rosemary (Rosmarinus officinalis), and thyme (Thymus vulgaris) were tested for antimicrobial activities against Paenibacillus larvae, the causal agent of American Foulbrood Disease (AFB) of honey bees. Trials for determining the minimum inhibitory concentration (MIC) of these oils

  7. Antimicrobial activity of some medicinal plants from the cerrado of the centralwestern region of Brazil.

    PubMed

    Violante, Ivana Maria Póvoa; Hamerski, Lidilhone; Garcez, Walmir Silva; Batista, Ana Lucia; Chang, Marilene Rodrigues; Pott, Vali Joana; Garcez, Fernanda Rodrigues

    2012-10-01

    Ethanol extracts from six selected species from the Cerrado of the Central-Western region of Brazil, which are used in traditional medicine for the treatment of infectious diseases and other medical conditions, namely Erythroxylum suberosum St. Hil. (Erythroxylaceae), Hyptis crenata Pohl. ex Benth. (Lamiaceae), Roupala brasiliensis Klotz. (Proteaceae), Simarouba versicolor St. Hil. (Simaroubaceae), Guazuma ulmifolia Lam. (Sterculiaceae) and Protium heptaphyllum (Aubl.) March. (Burseraceae), as well as fractions resulting from partition of these crude extracts, were screened in vitro for their antifungal and antibacterial properties. The antimicrobial activities were assessed by the broth microdilution assay against six control fungal strains, Candida albicans, C. glabrata, C. krusei, C. parapsilosis, C. tropicalis and Cryptococcus neoformans, and five control Gram-positive and negative bacterial strains, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. Toxicity of the extracts and fractions against Artemia salina was also evaluated in this work. All plants investigated showed antimicrobial properties against at least one microorganism and two species were also significantly toxic to brine shrimp larvae. The results tend to support the traditional use of these plants for the treatment of respiratory and gastrointestinal disorders and/or skin diseases, opening the possibility of finding new antimicrobial agents from these natural sources. Among the species investigated, Hyptis crenata, Erythroxylum suberosum and Roupala brasiliensis were considered the most promising candidates for developing of future bioactivity-guided phytochemical investigations. PMID:24031956

  8. Plants belonging to the genus Thymus as antibacterial agents: from farm to pharmacy.

    PubMed

    Nabavi, Seyed Mohammad; Marchese, Anna; Izadi, Morteza; Curti, Valeria; Daglia, Maria; Nabavi, Seyed Fazel

    2015-04-15

    In traditional medicine, plants have been used since ancient times for the prevention and/or protection against infectious diseases. In recent years, the use of herbal medicines and food supplements containing botanical ingredients, as alternative therapy for infectious diseases, has been intensified due to their high content of antimicrobial agents such as polyphenols, i.e. flavonoids, tannins, and alkaloids. Plants from the genus Thymus are important medicinal herbs, which are known to contain antimicrobial agents, and are rich in different active substances such as thymol, carvacrol, p-cymene and terpinene. In this review, we summarise the available literature data about the in vitro antibacterial effects of the main plants belonging to the genus Thymus. We also provide information about cultivation, chemical composition of the essential oils obtained from these plants, and their use for medicinal purposes. PMID:25466031

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

    PubMed Central

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

    2012-01-01

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

  10. Antimicrobial activity of selected South African medicinal plants

    PubMed Central

    2012-01-01

    Background Nearly 3,000 plant species are used as medicines in South Africa, with approximately 350 species forming the most commonly traded and used medicinal plants. In the present study, twelve South African medicinal plants were selected and tested for their antimicrobial activities against eight microbial species belonging to fungi, Mycobacteria, Gram-positive and Gram-negative bacteria. Methods The radiometric respiratory technique using the BACTEC 460 system was used for susceptibility testing against Mycobacterium tuberculosis, and the liquid micro-broth dilution was used for other antimicrobial assays. Results The results of the minimal inhibitory concentration (MIC) determinations indicated that the methanol extracts from Acacia karoo, Erythrophleum lasianthum and Salvia africana were able to prevent the growth of all the tested microorganisms. All other samples showed selective activities. MIC values below 100??g/ml were recorded with A. karoo, C. dentate, E. lasianthum, P. obligun and S. africana on at least one of the nine tested microorganisms. The best activity (MIC value of 39.06??g/ml) was noted with S. africana against E. coli, S. aureus and M. audouinii, and Knowltonia vesitoria against M. tuberculosis. Conclusion The overall results of the present work provide baseline information for the possible use of the studied South African plant extracts in the treatment of microbial infections. PMID:22704594

  11. Synthesis and evaluation of some new benzothiazole derivatives as potential antimicrobial agents

    Microsoft Academic Search

    Balram Soni; Mahendra Singh Ranawat; Rambabu Sharma; Anil Bhandari; Sanjay Sharma

    2010-01-01

    As benzothiazole has proven to be good antimicrobial agent, a novel series of Schiff bases of benzothiazole derivatives were synthesized. Thus condensation of 5-[2-(1,3-benzothiazol-2-yl-amino) ethyl]-4-amino-3-mercapto-(4H)-1,2,4-triazole 5 with appropriate aromatic aldehydes afforded 5-[2-(1,3-benzothiazol-2-yl-amino)ethyl]-4-(arylideneamino)-3-mercapto-(4H)-1,2,4-triazoles 6a–g. Structures of the synthesized compounds were elucidated on the basis of elemental analyses and spectral data. All the synthesized compounds were screened for their antimicrobial activity.

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

    PubMed

    Ahn, Yong-Yeol; Lee, Deok-Sun; Burd, Henry; Blank, William; Kapatral, Vinayak

    2014-01-01

    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. PMID:24454817

  13. Photo induced silver on nano titanium dioxide as an enhanced antimicrobial agent for wool.

    PubMed

    Montazer, Majid; Behzadnia, Amir; Pakdel, Esfandiar; Rahimi, Mohammad Karim; Moghadam, Mohammad Bameni

    2011-06-01

    In this study an effective nanocomposite antimicrobial agent for wool fabric was introduced. The silver loaded nano TiO(2) as a nanocomposite was prepared through UV irradiation in an ultrasonic bath. The nanocomposite was stabilized on the wool fabric surface by using citric acid as a friendly cross-linking agent. The treated wool fabrics indicated an antimicrobial activity against both Staphylococcus aureus and Escherichia coli bacteria. Increasing the concentration of Ag/TiO(2) nanocomposite led to an improvement in antibacterial activities of the treated fabrics. Also increasing the amount of citric acid improved the adsorption of Ag/TiO(2) on the wool fabric surface leading to enhance antibacterial activity. The EDS spectrum, SEM images, and XRD patterns was studied to confirm the presence of existence of nanocomposite on the fabric surface. The role of both cross-linking agent and nanocomposite concentrations on the results was investigated using response surface methodology (RSM). PMID:21474327

  14. Metabolic Network Analysis-Based Identification of Antimicrobial Drug Targets in Category A Bioterrorism Agents

    PubMed Central

    Ahn, Yong-Yeol; Lee, Deok-Sun; Burd, Henry; Blank, William; Kapatral, Vinayak

    2014-01-01

    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. PMID:24454817

  15. Treatment of lepromatous ulcers using citric acid as a sole antimicrobial agent.

    PubMed

    Nagoba, Basavraj S; Wadher, Bharat J; Rao, Arunkumar; Selkar, Sohan P; Gandhi, Rajan C

    2012-10-01

    A prospective study was carried out to assess the role of citric acid as a sole antimicrobial agent in the management of lepromatous ulcers. Thirty-four known cases of lepromatous ulcers not responding to conventional antibiotic therapies for long duration were investigated for culture and susceptibility studies. Staphylococcus aureus (25·00%) and Klebsiella spp. (23·43%) were found to be the most common isolates. Amikacin (68·75%) and ciprofloxacin (67·18%) were found to be the most effective antimicrobial agents. Topical application of citric acid ointment resulted in complete healing in 25 (73·52%) cases. In eight cases (26·48%), there was elimination of infective agent from ulcer site and formation of healthy granulation, but no complete healing of ulcer was seen. Results indicate that citric acid is the best alternative for the effective management of lepromatous ulcers when other therapies are exhausted. PMID:22264346

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

    Microsoft Academic Search

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

    1999-01-01

    Aqueous and methanolic extracts from different parts of nine traditional Zulu medicinal plants, of the Vitaceae from KwaZulu-Natal, South Africa were evaluated for therapeutic potential as anti-inflammatory and anti-microbial agents. Of the twenty-nine crude extracts assayed for prostaglandin synthesis inhibitors, only five methanolic extracts of Cyphostemma natalitium-root, Rhoicissus digitata-leaf, R. rhomboidea-root, R. tomentosa-leaf\\/stem and R. tridentata-root showed significant inhibition of

  17. Recombinant antimicrobial peptide hPAB-? expressed in Pichia pastoris , a potential agent active against methicillin-resistant Staphylococcus aureus

    Microsoft Academic Search

    Zhijin Chen; Dongmei Wang; Yanguang Cong; Jing Wang; Junmin Zhu; Jie Yang; Zhen Hu; Xiaomei Hu; Yinling Tan; Fuquan Hu; Xiancai Rao

    2011-01-01

    As a potential therapeutic agent, antimicrobial peptide has received increased attention in recent years. However, high-level\\u000a expression of a small peptide with antimicrobial activity is still a challenging task. In this study, the coding sequence\\u000a of antimicrobial peptide hPAB-?, a variant derived from human beta-defensin 2, was cloned into pPIC9K vector and transformed\\u000a into Pichia pastoris. P. pastoris transformants harbored

  18. Essential oils from aromatic herbs as antimicrobial agents.

    PubMed

    Solórzano-Santos, Fortino; Miranda-Novales, Maria Guadalupe

    2012-04-01

    Bacterial resistance to multiple antibiotics is a health problem. Essential oils (EOs) possess antibacterial properties and have been screened as potential sources of novel antimicrobial compounds. Terpenes and terpenoids are components derived from EOs. Some of these EOs show inhibitory activity against Staphylococcus aureus. Carvacrol has specific effects on S. aureus and Staphylococcus epidermidis. Perilla oil suppresses expression of ?-toxin, Staphylococcus enterotoxin A and B and toxic shock syndrome toxin. Geraniol shows good activity in modulating drug resistance in several gram-negative species. EOs could act as biopreservatives, reducing or eliminating pathogenic bacteria and increasing the overall quality of animal and vegetable food products. Although clinical studies are scarce, the uses of EOs for topical administration and as penetration enhancers for antiseptics are promising. Little information exists for oral administration. PMID:21903378

  19. The in vitro efficacy of antimicrobial agents against the pathogenic free-living amoeba Balamuthia mandrillaris.

    PubMed

    Ahmad, Arine F; Heaselgrave, Wayne; Andrew, Peter W; Kilvington, Simon

    2013-01-01

    The free-living amoeba Balamuthia mandrillaris causes usually fatal encephalitis in humans and animals. Only limited studies have investigated the efficacy of antimicrobial agents against the organism. Assay methods were developed to assess antimicrobial efficacy against both the trophozoite and cyst stage of B. mandrillaris (ATCC 50209). Amphotericin B, ciclopirox olamine, miltefosine, natamycin, paromomycin, pentamidine isethionate, protriptyline, spiramycin, sulconazole and telithromycin had limited activity with amoebacidal levels of > 135-500 ?M. However, diminazene aceturate (Berenil(®) ) was amoebacidal at 7.8 ?M and 31.3-61.5 ?M for trophozoites and cysts, respectively. Assays for antimicrobial testing may improve the prognosis for infection and aid in the development of primary selective culture isolation media. PMID:23869955

  20. Self-assembled cationic peptide nanoparticles as an efficient antimicrobial agent

    NASA Astrophysics Data System (ADS)

    Liu, Lihong; Xu, Kaijin; Wang, Huaying; Jeremy Tan, P. K.; Fan, Weimin; Venkatraman, Subbu S.; Li, Lanjuan; Yang, Yi-Yan

    2009-07-01

    Antimicrobial cationic peptides are of interest because they can combat multi-drug-resistant microbes. Most peptides form ?-helices or ?-sheet-like structures that can insert into and subsequently disintegrate negatively charged bacterial cell surfaces. Here, we show that a novel class of core-shell nanoparticles formed by self-assembly of an amphiphilic peptide have strong antimicrobial properties against a range of bacteria, yeasts and fungi. The nanoparticles show a high therapeutic index against Staphylococcus aureus infection in mice and are more potent than their unassembled peptide counterparts. Using Staphylococcus aureus-infected meningitis rabbits, we show that the nanoparticles can cross the blood-brain barrier and suppress bacterial growth in infected brains. Taken together, these nanoparticles are promising antimicrobial agents that can be used to treat brain infections and other infectious diseases.

  1. The Role and Efficacy of Herbal Antimicrobial Agents in Orthodontic Treatment

    PubMed Central

    Mishra, Sumita; Kumar Sahu, Sanjeeb; Bhusan Nanda, Smruti; Charan Sahu, Kanhu

    2014-01-01

    Aims: To assess the effect of herbal antimicrobial agents on Streptococcus mutans count in biofilm formations during orthodontic treatment. Materials and Methods: We calculated the growth inhibition of oral bacteria in the orthodontic appliances after herbal antibacterial agents were placed in culture media. The Minimum Inhibitory Concentrations (MICs) of these agents on Streptococcus mutans growth were determined. After cultivating colonies of Streptococci in biofilm medium with these herbal antimicrobial agents and orthodontic attachments, viable cell counting was performed from the bacteria which were attached on them. Scanning electron microscopy (SEM) analysis of morphology was observed on bacterial cells which were attached to orthodontic attachments. The effects of these agents were then evaluated and recommendations were forwarded. Results: There was an increase in count of Streptococcus mutans with respect to the herbal antibacterial agents. Conclusion: Despite the antibacterial functions of these herbal agents, there was increase in the biofilm formation caused by Streptococcus mutans to orthodontic bands, which had occurred most likely through upregulation of glucosyl transferase expression. These extracts may thus play an important role in increased bacterial attachment to orthodontic wires. Thus, this study was corroborative of an amalgamation of Ayurvedic therapy and Orthodontic treatment. PMID:25121056

  2. From individual to collective immunity: The role of the venom as antimicrobial agent in the Stenogastrinae wasp societies

    E-print Network

    Chittka, Lars

    From individual to collective immunity: The role of the venom as antimicrobial agent is represented by antimicrobial secretions. In many eusocial hymenopteran species venom glands represent one the venom is spread on both the cuticle of insects and the comb, thus becoming a component of the so called

  3. A Study of Utilization of Antimicrobial Agents in Patients on Ventilator in Intensive Care Unit (ICU) at Tertiary Care Teaching Hospital, India

    PubMed Central

    Gandhi, Anuradha M; Patel, Prakruti P

    2014-01-01

    Objective: To study the use of antimicrobial agents in patients on ventilator in ICU. Materials and Methods: Study was conducted at tertiary care teaching hospital Ahmedabad, India. Total 300 patients admitted in ICU and prescribed antimicrobial agents were included in the study. The data were recorded in preformed Case Record Form (CRF) and were analysed by Z and x2 Test. Results: Patients were divided into group A (patients on ventilator support) and group B (patients without ventilator support). In all the patients antimicrobial agents were prescribed empirically and more than two antimicrobial agents were prescribed in both groups. It was observed that above 60% antimicrobial agents were prescribed according to WHO, National and State Essential Medicine List (EML). Restricted antimicrobial agents (according to antimicrobial policy of tertiary care teaching hospital) were prescribed significantly (p<0.05) higher in group A as compared to group B. Resistance to antimicrobial agents by Pseudomonas aeruginosa and Kleibsella shown significantly (p<0.05) higher in group A as compared to group B. Change of antimicrobial therapy after Culture Sensitivity Test (CST) was significantly (p<0.05) higher in group A as compared to group B. Conclusion: Number of antimicrobial agents, antimicrobial resistance and change of antimicrobial therapy after CST were higher in patients on ventilator support. PMID:25584243

  4. Quaternized N-substituted carboxymethyl chitosan derivatives as antimicrobial agents.

    PubMed

    Mohamed, Nadia A; Sabaa, Magdy W; El-Ghandour, Ahmed H; Abdel-Aziz, Marwa M; Abdel-Gawad, Omayma F

    2013-09-01

    Introduction of quaternary ammonium moieties into N-substituted carboxymethyl chitosan (N-substituted CMCh) derivatives enhances their biological activity. Several derivatives of CMCh having a variety of N-aryl substituents bearing either electron-donating or electron withdrawing groups have been synthesized by the reaction between amino group of CMCh with various aromatic aldehydes under acidic conditions, followed by reduction of the produced Schiff base derivatives with sodium cyanoborohydride. Each of the reduced derivatives was further quaternized using N-(3-chloro-2-hydroxy-propyl)trimethylammonium chloride (Quat-188). The resulting quaternized materials were characterized by FTIR and (1)H NMR spectroscopy. Their antibacterial activities against Streptococcus pneumoniae (S. pneumonia, RCMB 010010), Bacillis subtilis (B. subtilis, RCMB 010067), as Gram positive bacteria and against Escherichia coli (E. coli, RCMB 010052) as Gram negative bacteria and their antifungal activities against Aspergillus fumigatus (A. fumigates, RCMB 02568), Geotricum candidum (G. candidum, RCMB 05097), and Candida albicans (C. albicans, RCMB 05031) were examined using agar disk diffusion method. The results indicated that all the quaternized derivatives showed better antimicrobial activities than that of CMCh. These derivatives are highly potent against Gram positive bacteria compared to Gram negative bacteria. This is illustrated for example as the values of minimum inhibitory concentration (MIC) of Q4NO2-BzCMCh against B. subtilis and S. pneumonia were 6.25 and 12.5 ?g/mL, respectively corresponded to 20.0 ?g/mL against E. coli. The antimicrobial activity of quaternized N-aryl CMCh derivatives affected by not only the nature of the microorganisms but also by the nature, position and number of the substituent groups on the phenyl ring. Thus while the derivatives with groups of electron withdrawing nature show higher inhibition zone diameter and lower MIC values relative to that of those having electron-donating nature, the non-substituted derivative lies between these two extremes. Antibacterial activities of Q4NO2-BzCMCh, Q3Cl-BzCMCh and Q3Br-BzCMCh against E. coli are nearly equivalent to that of the standard drug Gentamycin. Q3Br-BzCMCh emerged almost equivalent antibacterial activity to Ampicillin against S. pneumonia. PMID:23732327

  5. Resistance of gram-negative bacilli as related to hospital use of antimicrobial agents.

    PubMed Central

    Ma, M Y; Goldstein, E J; Friedman, M H; Anderson, M S; Mulligan, M E

    1983-01-01

    The development of resistance of gram-negative bacilli, which are common nosocomial pathogens, is an increasing problem. It is generally accepted that this resistance may directly reflect the frequency of use of various antimicrobial agents. Because our institution experienced in 1976 a dramatic change in the pattern of antimicrobial use, primarily a marked decrease in prescribing cephalosporins, we attempted to evaluate retrospectively the effects of this change upon the resistance of gram-negative bacilli that are common nosocomial pathogens. Susceptibilities of Klebsiella and Providencia spp., Pseudomonas aeruginosa, and Serratia marcescens were determined for the years 1975 to 1979. Not unexpectedly, we observed a substantial decrease in cephalosporin resistance. An unexpected finding was a decrease in aminoglycoside resistance, despite increased use of these agents. The possibility that decreased cephalosporin use may lead to decreased aminoglycoside resistance is an intriguing and provocative thesis which can only be speculative at this time but which would seem worthy of additional formal investigation. PMID:6638994

  6. In Vitro Activity of A-86719.1, a Novel 2Pyridone Antimicrobial Agent

    Microsoft Academic Search

    G. M. ELIOPOULOS; C. B. WENNERSTEN; G. COLE; D. CHU; D. PIZZUTI; C. MOELLERING

    1995-01-01

    This study evaluated the in vitro activity of A-86719.1, a novel 2-pyridone antimicrobial agent. The drug inhibited all tested members of the family Enterobacteriaceae at #0.5 mg\\/ml and all tested Pseudomonas aeruginosa,Burkholderia(Pseudomonas)cepacia, andXanthomonas maltophiliastrains at #2 mg\\/ml. All but two strains of gram-positive bacteria were inhibited by #1 mg of the new drug per ml, including isolates highly resistant to

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

    NASA Astrophysics Data System (ADS)

    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 ?-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.

  8. Morphological and biochemical changes in Pseudomonas fluorescens biofilms induced by sub-inhibitory exposure to antimicrobial agents.

    PubMed

    Dynes, James J; Lawrence, John R; Korber, Darren R; Swerhone, George D W; Leppard, Gary G; Hitchcock, Adam P

    2009-02-01

    Confocal laser scanning microscopy (CLSM) and scanning transmission X-ray microscopy (STXM) were used to examine the morphological and biochemical changes in Pseudomonas fluorescens biofilms grown in the presence of subinhibitory concentrations of 4 antimicrobial agents: triclosan, benzalkonium chloride, chlorhexidine dihydrochloride, and trisodium phosphate. CLSM analyses using the stains SYTO9 and propidium iodide indicated that the antimicrobial agents affected cell membrane integrity and cellular density to differing degrees. However, fluorescein diacetate assays and plate counts demonstrated that the cells remained metabolically active. Fluorescent lectin binding assays showed that changes in the arrangement and composition of the exopolymer matrix of the biofilms also occurred and that these changes depended on the antimicrobial agent. Detailed single cell analyses using STXM provided evidence that the cell morphology, and the spatial distribution and relative amounts of protein, lipids and polysaccharides in the biofilms and within the cells were different for each antimicrobial. The distribution of chlorhexidine in the biofilm, determined from its distinct spectral signature, was localized mainly inside the bacterial cells. Each antimicrobial agent elicited a unique response; P. fluorescens cells and biofilms changed their morphology and architecture, as well as the distribution and abundance of biomacromolecules, in particular the exopolymer matrix. Pseudomonas fluorescens also exhibited adaptation to benzalkonium chloride at 10 microg/mL. Our observations point to the importance of changes in the quantity and chemistry of the exopolymeric matrix in the response to antimicrobial agents and suggest their importance as targets for control. PMID:19295649

  9. Antimicrobial activity of essential oils and other plant extracts.

    PubMed

    Hammer, K A; Carson, C F; Riley, T V

    1999-06-01

    The antimicrobial activity of plant oils and extracts has been recognized for many years. However, few investigations have compared large numbers of oils and extracts using methods that are directly comparable. In the present study, 52 plant oils and extracts were investigated for activity against Acinetobacter baumanii, Aeromonas veronii biogroup sobria, Candida albicans, Enterococcus faecalis, Escherichia col, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhimurium, Serratia marcescens and Staphylococcus aureus, using an agar dilution method. Lemongrass, oregano and bay inhibited all organisms at concentrations of < or = 2.0% (v/v). Six oils did not inhibit any organisms at the highest concentration, which was 2.0% (v/v) oil for apricot kernel, evening primrose, macadamia, pumpkin, sage and sweet almond. Variable activity was recorded for the remaining oils. Twenty of the plant oils and extracts were investigated, using a broth microdilution method, for activity against C. albicans, Staph. aureus and E. coli. The lowest minimum inhibitory concentrations were 0.03% (v/v) thyme oil against C. albicans and E. coli and 0.008% (v/v) vetiver oil against Staph. aureus. These results support the notion that plant essential oils and extracts may have a role as pharmaceuticals and preservatives. PMID:10438227

  10. Potential of antimicrobial agents to inhibit fungi to aid isolation of Campylobacter.

    PubMed

    Murinda, Shelton E; Nguyen, Lien T; Headrick, Susan J; Meleo, Paola; Oliver, Stephen P

    2006-01-01

    In preliminary studies conducted to isolate thermophilic Campylobacter spp. from cull dairy cow fecal samples, growth of fungal strains on Abeyta-Hunt-Bark agar and charcoal cefoperazone desoxycholate agar (CCDA) interfered with isolation of target bacteria. Concentrations of antifungal substances in the agar media were not effective in suppressing growth of antibiotic resistant fungi. The objective of the current study was to determine the efficacy of supplemental antimicrobial agents to inhibit growth of fungi of fecal origin on Campylobacter isolation media where microbial growth is overwhelmed by fungi. The inhibitory effect of rifampicin and seven antimycotic agents--cycloheximide, 5-fluorouracil, 5-fluorocytosine, sodium propionate, potassium sorbate, nystatin, and amphotericin B--was evaluated. Antimicrobial agents were added singly or combined at concentrations ranging from 12.3 to 227 mg/L. Incubation was conducted at 42 degrees C for 24-48 h in gas jars (CO2+H2). The most effective antibiotic combinations that inhibited fungal growth without affecting Campylobacter growth were CCDA selective supplement SR155E with amphotericin B (59.5 or 114 mg/L) or a mixture of rifampicin, 5-fluorocytosine, and nystatin (119 or 227 mg/L each). Results of the present study indicate that addition of supplemental antifungal agents in the presence of antibiotics such as rifampicin may enhance suppression of fungal overgrowth on Campylobacter isolation agar media. PMID:16972780

  11. Mechanisms of antiviral action of plant antimicrobials against murine norovirus.

    PubMed

    Gilling, Damian H; Kitajima, Masaaki; Torrey, Jason R; Bright, Kelly R

    2014-08-01

    Numerous plant compounds have antibacterial or antiviral properties; however, limited research has been conducted with nonenveloped viruses. The efficacies of allspice oil, lemongrass oil, and citral were evaluated against the nonenveloped murine norovirus (MNV), a human norovirus surrogate. The antiviral mechanisms of action were also examined using an RNase I protection assay, a host cell binding assay, and transmission electron microscopy. All three antimicrobials produced significant reductions (P ? 0.05) in viral infectivity within 6 h of exposure (0.90 log10 to 1.88 log10). After 24 h, the reductions were 2.74, 3.00, and 3.41 log10 for lemongrass oil, citral, and allspice oil, respectively. The antiviral effect of allspice oil was both time and concentration dependent; the effects of lemongrass oil and citral were time dependent. Based on the RNase I assay, allspice oil appeared to act directly upon the viral capsid and RNA. The capsids enlarged from ? 35 nm to up to 75 nm following treatment. MNV adsorption to host cells was not significantly affected. Alternatively, the capsid remained intact following exposure to lemongrass oil and citral, which appeared to coat the capsid, causing nonspecific and nonproductive binding to host cells that did not lead to successful infection. Such contrasting effects between allspice oil and both lemongrass oil and citral suggest that though different plant compounds may yield similar reductions in virus infectivity, the mechanisms of inactivation may be highly varied and specific to the antimicrobial. This study demonstrates the antiviral properties of allspice oil, lemongrass oil, and citral against MNV and thus indicates their potential as natural food and surface sanitizers to control noroviruses. PMID:24907316

  12. Mechanisms of Antiviral Action of Plant Antimicrobials against Murine Norovirus

    PubMed Central

    Gilling, Damian H.; Kitajima, Masaaki; Torrey, Jason R.

    2014-01-01

    Numerous plant compounds have antibacterial or antiviral properties; however, limited research has been conducted with nonenveloped viruses. The efficacies of allspice oil, lemongrass oil, and citral were evaluated against the nonenveloped murine norovirus (MNV), a human norovirus surrogate. The antiviral mechanisms of action were also examined using an RNase I protection assay, a host cell binding assay, and transmission electron microscopy. All three antimicrobials produced significant reductions (P ? 0.05) in viral infectivity within 6 h of exposure (0.90 log10 to 1.88 log10). After 24 h, the reductions were 2.74, 3.00, and 3.41 log10 for lemongrass oil, citral, and allspice oil, respectively. The antiviral effect of allspice oil was both time and concentration dependent; the effects of lemongrass oil and citral were time dependent. Based on the RNase I assay, allspice oil appeared to act directly upon the viral capsid and RNA. The capsids enlarged from ?35 nm to up to 75 nm following treatment. MNV adsorption to host cells was not significantly affected. Alternatively, the capsid remained intact following exposure to lemongrass oil and citral, which appeared to coat the capsid, causing nonspecific and nonproductive binding to host cells that did not lead to successful infection. Such contrasting effects between allspice oil and both lemongrass oil and citral suggest that though different plant compounds may yield similar reductions in virus infectivity, the mechanisms of inactivation may be highly varied and specific to the antimicrobial. This study demonstrates the antiviral properties of allspice oil, lemongrass oil, and citral against MNV and thus indicates their potential as natural food and surface sanitizers to control noroviruses. PMID:24907316

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

    PubMed

    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. PMID:22029522

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

    PubMed Central

    Askoura, Momen; Mottawea, Walid; Abujamel, Turki; Taher, Ibrahim

    2011-01-01

    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 ?-naphthylamide (PA?N) 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 PA?N 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. PMID:21594004

  15. Antimicrobial and cytotoxic activities screening of some Brazilian medicinal plants used in Governador Valadares district

    Microsoft Academic Search

    Beatriz Gonçalves Brasileiro; Virgínia Ramos Pizziolo; Délio Soares Raslan; Claudia Mashrouah Jamal; Dâmaris Silveira

    2006-01-01

    Ethanol extracts from medicinal plants commonly used by Governador Valadares people were tested for antimicrobial activity and cytotoxicity (BST assay). The field survey was conducted during the years 1997-2000 by means of direct interviews with healing men (\\

  16. Synthesis and biological evaluation of pyrazolylthiazole carboxylic acids as potent anti-inflammatory-antimicrobial agents.

    PubMed

    Khloya, Poonam; Kumar, Satish; Kaushik, Pawan; Surain, Parveen; Kaushik, Dhirender; Sharma, Pawan K

    2015-03-15

    Current Letter presents design, synthesis and biological evaluation of a novel series of pyrazolylthiazole carboxylates 1a-1p and corresponding acid derivatives 2a-2p. All 32 novel compounds were tested for their in vivo anti-inflammatory activity by carrageenan-induced rat paw edema method as well as for in vitro antimicrobial activity. All the tested compounds exhibited excellent AI activity profile. Three compounds 1p (R=Cl, R(1)=Cl), 2c (R=H, R(1)=F) and 2n (R=Cl, R(1)=OCH3) were identified as potent anti-inflammatory agents exhibiting edema inhibition of 93.06-89.59% which is comparable to the reference drug indomethacin (91.32%) after 3h of carrageenan injection while most of the other compounds displayed inhibition ?80%. In addition, pyrazolylthiazole carboxylic acids (2a-2p) also showed good antimicrobial profile. Compound 2h (R=OCH3, R(1)=Cl) showed excellent antimicrobial activity (MIC 6.25?g/mL) against both Gram positive bacteria comparable with the reference drug ciprofloxacin (MIC 6.25?g/mL). PMID:25702850

  17. Antimicrobial activity of some medicinal plants from India.

    PubMed

    Samy, R Perumal

    2005-12-01

    The results of a preliminary antimicrobial screening of the methanol extracts of Zingiber officinale, Asteracantha longifolia, Citrus acida, Salacia microsperma and Tinospora cordifolia are reported. PMID:16229969

  18. Prevalence, enumeration, and antimicrobial agent resistance of Clostridium difficile in cattle at harvest in the United States.

    PubMed

    Rodriguez-Palacios, Alexander; Koohmaraie, Mohammad; LeJeune, Jeffrey T

    2011-10-01

    To assess the potential for food contamination with Clostridium difficile from food animals, we conducted a cross-sectional fecal prevalence study in 944 randomly selected cattle harvested at seven commercial meat processing plants, representing four distant regions (median distance of 1,500 km) of the United States. In all, 944 animals were sampled in the summer of 2008. C. difficile was isolated from 1.8% (17 of 944) of cattle, with median fecal shedding concentration of 2.2 log CFU/g (range = 1.6 to 4.8, 95% confidence interval = 1.6, 4.3). Toxigenic C. difficile isolates were recovered from only four (0.4%) cattle. One of these isolates was emerging PCR ribotype 078/toxinotype V. The remaining toxigenic isolates were toxinotype 0, one of which was an isolate with resistance to linezolid, clindamycin, and moxifloxacin (by the E-test). All isolates were susceptible to vancomycin, metronidazole, and tigecycline, but the MICs against linezolid were as high as the highest reported values for human-derived isolates. The source of the linezolid-clindamycin-moxifloxacin resistance in a toxigenic C. difficile isolate from cattle is uncertain. However, since the use of these three antimicrobial agents in cattle is not allowed in North America, it is possible that resistance originated from an environmental source, from other species where those antimicrobial agents are used, or transferred from other intestinal bacteria. This study confirms that commercial cattle can carry epidemiologically relevant C. difficile strains at the time of harvest, but the prevalence at the time they enter the food chain is low. PMID:22004807

  19. Plant pathogens as biocontrol agents of Cirsium arvense an overestimated approach? 1 Plant pathogens as biocontrol agents of

    E-print Network

    Richner, Heinz

    Plant pathogens as biocontrol agents of Cirsium arvense ­ an overestimated approach? 1 Plant pathogens as biocontrol agents of Cirsium arvense ­ an overestimated approach? Esther Müller1 , Wolfgang: Müller E, Nentwig W (2011) Plant pathogens as biocontrol agents of Cirsium arvense ­ an overestimated

  20. Synthesis and biological evaluation of pyrazoline derivatives bearing an indole moiety as new antimicrobial agents.

    PubMed

    Özdemir, Ahmet; Altintop, Mehlika Dilek; Kaplanc?kl?, Zafer Asim; Turan-Zitouni, Gülhan; Karaca, Hülya; Tunal?, Ya?mur

    2013-06-01

    1-(p-Methylphenyl)-3,5-diaryl-2-pyrazoline derivatives (2a-f) were synthesized via the treatment of 1-(1H-indol-3-yl)-3-aryl-2-propen-1-ones (1a-f) with p-methylphenylhydrazine hydrochloride in hot acetic acid. The structures of these compounds were elucidated by IR, ¹H NMR, and mass spectral data and elemental analysis. These compounds were investigated for their antimicrobial activity. Brine-Shrimp lethality assay was carried out to determine the toxicity of the compounds. Compound 2e, which is the pyrazoline derivative bearing the 2,5-dichlorophenyl moiety, can be identified as the most promising agent against Klebsiella pneumoniae (ATCC 13883) and Candida glabrata (ATCC 36583) due to its inhibitory effects on K. pneumoniae and C. glabrata with a MIC value of 100 µg/mL as a non-toxic agent (LC?? > 1000 µg/mL). PMID:23681942

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

    NASA Astrophysics Data System (ADS)

    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 concentrations of nanoparticles incorporated into the polymer. The incorporation of LDH modified by sodium benzoate further improved the mechanical properties in comparison with unmodified LDH, which may be due to the increased compatibility between PHBV and nanoparticles and the larger basal distance between nanolayers after modification. The concentration of benzoate anions in LDH nanoparticles was another factor which affected the properties of PHBV composite films. The PHBV film with 2% modified LDH with 20.9 % w/w of benzoate anions in LDH had the best mechanical and thermomechanical properties. Apparent glass transition temperature increased with the addition of modified LDH but did not change with the addition of unmodified LDH. Moreover, the effect of nanoparticles on thermal properties as well as crystallization of PHBV composites was dependent on the type of nanoparticles. A comparison of mechanical properties and release kinetics of antimicrobial agents directly dispersed in PHBV and modified in LDH and then dispersed in PHBV was made. The results indicated that mechanical properties increased and release rate decreased in the latter case. The release of benzoate and gallate into DI water from PHBV composite films with LDH modified by benzoate and gallate followed pseudo-Fickian behavior fitted with a power law model. The release of benzoate from PHBV composite films with LDH modified by benzoate was also fitted with a Weibull model indicating Fickian behavior in fractal substrate morphologically similar to the percolation cluster. The concentration of modified LDH and the loading of benzoate in modified LDH showed a significant effect on the release kinetics of benzoate. The diffusivities of benzoate at 21 °C ranged from 3.41 to14.97 x 10-16 m 2/s. The slowest release rate was achieved by the PHBV film containing 5 % w/w of modified LDH with medium loading of benzoate (21 % w/w of benzoate) in nanoparticles. The release of gallate from PHBV was much faster than that of benzoate. The effective diffusivity of benzoate increased with increase of temperature

  2. Effect of storage temperature and pH on the stability of antimicrobial agents in MIC trays.

    PubMed Central

    Hwang, J M; Piccinini, T E; Lammel, C J; Hadley, W K; Brooks, G F

    1986-01-01

    Twelve antimicrobial agents, ampicillin, aztreonam, cefamandole, cefazolin, cefonicid, ceforanide, ceftazidime, ceftizoxime, ceftriaxone, cefuroxime, ciprofloxacin, and norfloxacin, were prepared at pH 6.80 and 7.31 in microdilution trays for storage at 4, -10, -25, and -70 degrees C and for weekly susceptibility testing. All 12 drugs had stable biological activity when stored at -70 degrees C for 1 year. All but ampicillin and aztreonam were stable at -25 degrees C. Storage at -10 degrees C was least satisfactory. Desiccation occurred at 4 degrees C, but short-term storage at this temperature is possible since the antimicrobial agents are stable for up to several months. PMID:3711284

  3. Comparative In Vitro Activities of Ciprofloxacin, Gemifloxacin, Grepafloxacin, Moxifloxacin, Ofloxacin, Sparfloxacin, Trovafloxacin, and Other Antimicrobial Agents against Bloodstream Isolates of Gram-Positive Cocci

    Microsoft Academic Search

    DWIGHT HARDY; DANIEL AMSTERDAM; LIONEL A. MANDELL; COLEMAN ROTSTEIN

    2000-01-01

    The in vitro activity of gemifloxacin against 316 bloodstream isolates of staphylococci, pneumococci, and enterococci was compared with the activities of six fluoroquinolones and three other antimicrobial agents. Of the antimicrobial agents tested, gemifloxacin was the most potent against penicillin-intermediate and -resis- tant pneumococci, methicillin-susceptible and -resistant Staphylococcus epidermidis isolates, and coagulase- negative staphylococci. Due to the increasing penicillin resistance

  4. Antimicrobial activity of flavonoids in medicinal plants from Tafí del Valle (Tucumán, Argentina).

    PubMed

    Hernández, N E; Tereschuk, M L; Abdala, L R

    2000-11-01

    Preliminary studies of flavonoids have been realised in five native species from Tafí del Valle (Tucumán, Argentina) used in popular medicine. Most of compounds detected were flavonoids mono and dihydroxylated in B ring. Screening for antimicrobial activity against Gram positive and Gram negative microorganisms has been realised with Lippia turbinata, Satureja parvifolia, Sambucus peruviana, Verbena officinalis and Chenopodium graveolens. The total extracts of flavonoids of each plant were tested and four species studied showed antimicrobial activity. PMID:11025172

  5. Antibiofilm effect of plant derived antimicrobials on Listeria monocytogenes.

    PubMed

    Upadhyay, Abhinav; Upadhyaya, Indu; Kollanoor-Johny, Anup; Venkitanarayanan, Kumar

    2013-10-01

    The present study investigated the efficacy of sub-inhibitory concentrations (SICs, concentrations not inhibiting bacterial growth) and bactericidal concentrations (MBCs) of four, generally recognized as safe (GRAS), plant-derived antimicrobials (PDAs) in inhibiting Listeria monocytogenes (LM) biofilm formation and inactivating mature LM biofilms, at 37, 25 and 4 °C on polystyrene plates and stainless-steel coupons. In addition, the effect of SICs of PDAs on the expression of LM genes critical for biofilm synthesis was determined by real-time quantitative PCR. The PDAs and their SICs used for inhibition of biofilm were trans-cinnamaldehyde (TC 0.50, 0.75 mM), carvacrol (CR 0.50, 0.65 mM), thymol (TY 0.33, 0.50 mM), and eugenol (EG 1.8, 2.5 mM), whereas the PDA concentrations used for inactivating mature biofilms were 5.0 and 10.0 mM (TC, CR), 3.3 and 5.0 mM (TY), 18.5 and 25.0 mM (EG). All PDAs inhibited biofilm synthesis and inactivated fully formed LM biofilms on both matrices at three temperatures tested (P < 0.05). Real-time quantitative PCR data revealed that all PDAs down-regulated critical LM biofilm-associated genes (P < 0.05). Results suggest that TC, CR, TY, and EG could potentially be used to control LM biofilms in food processing environments, although further studies under commercial settings are necessary. PMID:23764223

  6. Comparative In Vitro Activity of Faropenem and 11 Other Antimicrobial Agents Against 250 Invasive Streptococcus pneumoniae Isolates from France

    Microsoft Academic Search

    J. W. Decousser; P. Pina; F. Picot; P. Y. Allouch

    2003-01-01

    The aim of the study presented here was to evaluate the in vitro activity of faropenem, a new member of the penem class intended for oral administration, compared with 11 other antimicrobial agents against a large number of Streptococcus pneumoniae strains isolated from adults and children with bloodstream infections in France. The minimum inhibitory concentration of faropenem against 90% of

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  8. Edible Coating as Carrier of Antimicrobial Agents to Extend the Shelf Life of Fresh-Cut Apples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edible coatings with antimicrobial agents provide a novel way to improve the safety and shelf-life of fresh-cut fruit. The effect of lemongrass, oregano oil and vanillin, incorporated in apple puree-alginate edible coatings, on the shelf-life of fresh-cut Fuji apples, was investigated. Coated appl...

  9. In vitro activities of 18 antimicrobial agents against Staphylococcus aureus isolates from the Institut Pasteur of Madagascar

    Microsoft Academic Search

    Frédérique Randrianirina; Jean-Louis Soares; Elisoa Ratsima; Jean-François Carod; Patrice Combe; Pierre Grosjean; Vincent Richard; Antoine Talarmin

    2007-01-01

    BACKGROUND: Staphylococcus aureus, one of the most frequently isolated pathogens in both hospitals and the community, has been particularly efficient at developing resistance to antimicrobial agents. In developed countries, as methicillin-resistant S. aureus (MRSA) has prevailed and, furthermore, as S. aureus with reduced susceptibility to vancomycin has emerged, the therapeutic options for the treatment of S. aureus infections have become

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Phyllanthus wightianus Müll. Arg.: A Potential Source for Natural Antimicrobial Agents

    PubMed Central

    Natarajan, D.; Srinivasan, R.; Shivakumar, M. S.

    2014-01-01

    Phyllanthus wightianus belongs to Euphorbiaceae family having ethnobotanical importance. The present study deals with validating the antimicrobial potential of solvent leaf extracts of P. wightianus. 11 human bacterial pathogens (Bacillus subtilis, Streptococcus pneumoniae, Staphylococcus epidermidis, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhimurium, Escherichia coli, Shigella flexneri, Proteus vulgaris, and Serratia marcescens) and 4 fungal pathogens (Candida albicans, Cryptococcus neoformans, Mucor racemosus, and Aspergillus niger) were also challenged with solvent leaf extracts usingagar well and disc diffusion methods. Further, identification of the active component present in the bioactive extract was done using GC-MS analysis. Results show that all extracts exhibited broad spectrum (6–29?mm) of antibacterial activity on most of the tested organisms. The results highlight the fact that the well in agar method was more effective than disc diffusion method. Significant antimicrobial activity was detected in methanol extract against S. pneumoniae (29?mm) with MIC and MBC values of 15.62??g/mL. GC-MS analysis revealed that 29 bioactive constituents were present in methanolic extract of P. wightianus, of which 9,12-octadecaenioic acid (peak area 22.82%; RT-23.97) and N-hexadecanoic acid (peak area 21.55% RT-21.796) are the major compounds. The findings of this study show that P. wightianus extracts may be used as an anti-infective agent in folklore medicine. PMID:24883301

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    Kelly, Corey; Murphy, Megan; Giuliani, Maximiliano; Dutcher, John

    2011-03-01

    The pole-to-pole oscillation of the MinD proteins in E. coli 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 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. [4pt] [1] Raskin, D.M.; de Boer, P. (1999) Proc Natl. Acad. Sci. 96: 4971-4976.[0pt] [2] Colville, K.; Tompkins, N.; Rutenberg, A. D.; Jericho, M. H. (2010) Langmuir 2010:26.[0pt] [3] Downing, B.; Rutenberg, A.; Touhami, A.; Jericho, M. (2009) PLoS ONE 4: e7285.

  14. Antimicrobial, Antioxidant and Cytotoxic Activities and Phytochemical Screening of Some Yemeni Medicinal Plants

    Microsoft Academic Search

    Ramzi A. A. Mothana; Salah A. A. Abdo; Sidgi Hasson; Faisal M. N. Althawab; Sama A. Z. Alaghbari; Ulrike Lindequist

    2008-01-01

    The traditional medicine still plays an important role in the primary health care in Yemen. The current study represents the investigation of 16 selected plants, which were collected from different localities of Yemen. The plants were dried and extracted with two different solvents (methanol and hot water) to yield 34 crude extracts. The obtained extracts were tested for their antimicrobial

  15. Antimicrobial effects of Finnish plant extracts containing flavonoids and other phenolic compounds

    Microsoft Academic Search

    Jussi-Pekka Rauha; Susanna Remes; Marina Heinonen; Anu Hopia; Marja Kähkönen; Tytti Kujala; Kalevi Pihlaja; Heikki Vuorela; Pia Vuorela

    2000-01-01

    Plant phenolics, especially dietary flavonoids, are currently of growing interest owing to their supposed functional properties in promoting human health. Antimicrobial screening of 13 phenolic substances and 29 extracts prepared from Finnish plant materials against selected microbes was conducted in this study. The tests were carried out using diffusion methods with four to nine microbial species (Aspergillus niger, Bacillus subtilis,

  16. Antimicrobial activity of snakin-defensin hybrid protein in tobacco and potato plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To augment plant protection against phytopathogens, we constructed a fusion gene for the simultaneous expression of snakin-1 (SN1) and defensin-1 (PTH1) antimicrobial proteins as a hybrid protein (SAP) in plant cells. Prior to in vivo evaluation of SAP phytoprotective activity, the hybrid protein ex...

  17. Plants' Metabolites as Potential Antiobesity Agents

    PubMed Central

    Gooda Sahib, Najla; Saari, Nazamid; Ismail, Amin; Khatib, Alfi; Mahomoodally, Fawzi; Abdul Hamid, Azizah

    2012-01-01

    Obesity and obesity-related complications are on the increase both in the developed and developing world. Since existing pharmaceuticals fail to come up with long-term solutions to address this issue, there is an ever-pressing need to find and develop new drugs and alternatives. Natural products, particularly medicinal plants, are believed to harbor potential antiobesity agents that can act through various mechanisms either by preventing weight gain or promoting weight loss amongst others. The inhibition of key lipid and carbohydrate hydrolyzing and metabolizing enzymes, disruption of adipogenesis, and modulation of its factors or appetite suppression are some of the plethora of targeted approaches to probe the antiobesity potential of medicinal plants. A new technology such as metabolomics, which deals with the study of the whole metabolome, has been identified to be a promising technique to probe the progression of diseases, elucidate their pathologies, and assess the effects of natural health products on certain pathological conditions. This has been applied to drug research, bone health, and to a limited extent to obesity research. This paper thus endeavors to give an overview of those plants, which have been reported to have antiobesity effects and highlight the potential and relevance of metabolomics in obesity research. PMID:22666121

  18. Neutralization effect of some agents on the antimicrobial activity of ammoniacal silver nitrate.

    PubMed

    Lan, W H

    1978-03-01

    The effect of some agents on the antimicrobial activity of ammoniacal silver nitrate, an endodontic medicament, was tested with Streptococcus faecalis by the serial tube dilution method. Its results indicated that sodium hypochlorite, hydrogen peroxide, and blood had a marked inhibitory effect. However, the presence of dentin, necrotic tissue, saliva, and hydrogen sulfide gas liberated from protein decomposition showed no or little effect on the antibacterial properties of the chemical. Since antiseptics or antibiotics generally may be decomposed by necrotic tissues, these findings suggested that the use of ammoniacal silver nitrate not only may resolve the problem of recalcitrant cases in endodontic treatment but also may simplify the disinfecting procedure for root canals. PMID:415823

  19. Screening Various Plant and Fungal Extracts Against Clostridium perfringens for Antimicrobial Activity

    Microsoft Academic Search

    Thomas R. Larson

    2007-01-01

    Clostridium is an anaerobic, endospore forming Gram-positive bacillus genus containing many important pathogenic species, including Clostridium difficile and Clostridium perfringens. Both of these pathogenic species have been implicated as the causative agents of serious gastrointestinal tract infections. Recently, there has been an emergence of antimicrobial drug resistant Clostridium species. Because of these concerns, a new drug is warranted. There is

  20. Viability of Streptococcus mutans and Streptococcus sobrinus in whole saliva with varying concentrations of indigenous antimicrobial agents.

    PubMed

    Lenander-Lumikari, M; Tenovuo, J; Emilson, C G; Vilja, P

    1992-01-01

    We have studied the possible relationship between indigenous salivary antimicrobial agents, indigenous mutans streptococci and the capability of added mutans streptococci to grow in saliva. Stimulated whole saliva was collected from 19 healthy donors. Saliva samples were sterilized, supplemented with glucose and inoculated with Streptococcus mutans or Streptococcus sobrinus. The mixtures were incubated for 20 h followed by counting of viable cells. Saliva samples were analysed, both before and after sterilization, for indigenous antimicrobial agents and the bacterial flora. The subjects could be divided into two groups: those (n = 9) whose saliva promoted and those (n = 10) whose saliva inhibited the growth of the inoculated streptococci. A statistically significant correlation (+0.82, p < 0.001) was found between the numbers of viable cells of S. mutans and S. sobrinus after incubation in saliva. The sterilization procedure reduced the content of all antimicrobial proteins. Salivary antimicrobial factors, or levels of indigenous mutans streptococci, did not differ between the two groups. We conclude that none of the individual salivary antimicrobial factors alone can explain the large individual differences in growth-promoting or growth-inhibiting patterns of saliva on S. mutans and S. sobrinus. Inter-individually, saliva either supports or inhibits the growth of mutans streptococci, indicating a similar response of these two species in relation to the properties of saliva. PMID:1334804

  1. Antimicrobial compounds from the endophytic fungus Fusarium sp. Ppf4 isolated from the medicinal plant Paris polyphylla var. yunnanensis.

    PubMed

    Huang, Yongfu; Zhao, Jianglin; Zhou, Ligang; Wang, Mingan; Wang, Jingguo; Li, Xiaolin; Chen, Qing

    2009-11-01

    Two sterols and one fatty acid were obtained by bioassay-guided fractionation from the light petroleum extract of the fungus Fusarium sp. Ppf4 isolated from the rhizomes of Paris polyphylla var. yunnanensis Hand.-Mazz., a medicinal species distributed in the southwest of China. The compounds were elucidated as 5alpha, 8alpha-epidioxyergosta-6, 22-dien-3beta-ol (1), ergosta-8(9), 22-dien-3beta, 5alpha, 6beta, 7alpha-tetraol (2), and butanedioic acid (3), respectively, by means of physical and spectrometric analysis. Both fungal spore germination and micro-dilution-MTT assays were employed to evaluate their antimicrobial activity. Compound 1 was found to be the most bioactive, and compound 3 less active against the test pathogens. This is the first report of the antimicrobial activity of the compounds isolated from the endophytic Fusarium sp. Ppf4 associated with P. polyphylla var. yunnanensis. The results provide promising baseline information for the potential use of the compounds of this endophytic fungus as an antimicrobial agent to control plant and animal diseases. PMID:19967972

  2. Therapeutic Potential of Plants as Anti-microbials for Drug Discovery

    PubMed Central

    Perumal Samy, Ramar

    2010-01-01

    The uses of traditional medicinal plants for primary health care have steadily increased worldwide in recent years. Scientists are in search of new phytochemicals that could be developed as useful anti-microbials for treatment of infectious diseases. Currently, out of 80% of pharmaceuticals derived from plants, very few are now being used as anti-microbials. Plants are rich in a wide variety of secondary metabolites that have found anti-microbial properties. This review highlights the current status of traditional medicine, its contribution to modern medicine, recent trends in the evaluation of anti-microbials with a special emphasis upon some tribal medicine, in vitro and in vivo experimental design for screening, and therapeutic efficacy in safety and human clinical trails for commercial outlet. Many of these commercially available compounds are crude preparations administered without performing human clinical trials. Recent methods are useful to standardize the extraction for scientific investigation of new phytochemicals and anti-microbials of traditionally used plants. It is concluded that once the local ethnomedical preparations of traditional sources are scientifically evaluated before dispensing they should replace existing drugs commonly used for the therapeutic treatment of infection. This method should be put into practice for future investigations in the field of ethnopharmacology, phytochemistry, ethnobotany and other biological fields for drug discovery. PMID:18955349

  3. Essential oils and herbal extracts as antimicrobial agents in cosmetic emulsion.

    PubMed

    Herman, Anna; Herman, Andrzej Przemys?aw; Domagalska, Beata Wanda; M?ynarczyk, Andrzej

    2013-06-01

    The cosmetic industry adapts to the needs of consumers seeking to limit the use of preservatives and develop of preservative-free or self-preserving cosmetics, where preservatives are replaced by raw materials of plant origin. The aim of study was a comparison of the antimicrobial activity of extracts (Matricaria chamomilla, Aloe vera, Calendula officinalis) and essential oils (Lavandulla officinallis, Melaleuca alternifolia, Cinnamomum zeylanicum) with methylparaben. Extracts (2.5 %), essential oils (2.5 %) and methylparaben (0.4 %) were tested against Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Candida albicans ATCC 14053. Essentials oils showed higher inhibitory activity against tested microorganism strain than extracts and methylparaben. Depending on tested microorganism strain, all tested extracts and essential oils show antimicrobial activity 0.8-1.7 and 1-3.5 times stronger than methylparaben, respectively. This shows that tested extracts and essential oils could replace use of methylparaben, at the same time giving a guarantee of microbiological purity of the cosmetic under its use and storage. PMID:24426114

  4. Antimicrobial and free radical scavenging activities of five Palestinian medicinal plants.

    PubMed

    Qabaha, Khaled Ibraheem

    2013-01-01

    Extracts from five indigenous Palestinian medicinal plants including Rosmarinus officinalis, Pisidium guajava, Punica granatum peel, grape seeds and Teucrium polium were investigated for antimicrobial and free radical scavenging activities against eight microorganisms, using well diffusion method. The microorganisms included six bacterial isolates (i.e. Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginos, Klebsiella pneumonia, Bacillus subtilis and Micrococcus luteus) and two fungal isolates (i.e. Candida albicans and Aspergillus niger). A standard antioxidant assay was performed on the plant extracts to assess their capability in scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH). Of the five tested plant extract, only Rosmarinus offcinalis extract contained significant antimicrobial activity against all eight microbial isolates including Pseudomonas aeruginosa. Extracts from other four plants exhibited a variable antimicrobial activity against all microorganisms, except Pseudomonas aeruginosa. Significant antioxidant activity was detected in all plant extracts. However, extracts from Pisidium guajava leaves contained significantly higher antioxidant activity compared to the other extracts tested. The antimicrobial and scavenging activities detected in this in vitro study in extracts from the five Palestinian medicinal plants suggest that further study is needed to identify active compounds to target diseases caused by a wide-spectrum pathogens. PMID:24146509

  5. Antibiotic susceptibilities of periodontal bacteria. In vitro susceptibilities to eight antimicrobial agents.

    PubMed

    Walker, C B; Pappas, J D; Tyler, K Z; Cohen, S; Gordon, J M

    1985-11-01

    In vitro susceptibilities of 369 to 966 bacterial isolates from periodontal lesions to eight antibiotics were determined by agar dilution technique as a means of determining which antimicrobial agents were inhibitory for bacteria frequently associated with destructive periodontal diseases. Although most bacteria were relatively susceptible to the penicillins, greater activity was generally noted with amoxicillin than with either penicillin or ampicillin with the exception of Selenomonas sputigena and Peptostreptococcus. Antibacterial activities obtained with minocycline were significantly higher than with tetracycline for Actinobacillus actinomycetemcomitans and Streptococcus but comparable for most other taxa. Clindamycin and metronidazole both demonstrated excellent activity against the anaerobic Gram-negative rods but were less effective against some of the capnophilic and facultative organisms. Eikenella corrodens was exceptionally resistant to both of these drugs; and A. actinomycetemcomitans was generally resistant to clindamycin but relatively susceptible to metronidazole. Erythromycin was considerably less active than the other antibiotics against the majority of the periodontal bacteria. No single antibiotic, at concentrations equivalent to those achieved in body fluids, was uniformly effective in inhibiting all bacteria currently implicated or suspected as etiologic agents of periodontal diseases. PMID:3866054

  6. Assessment of antimicrobial (host defense) peptides as anti-cancer agents.

    PubMed

    Douglas, Susan; Hoskin, David W; Hilchie, Ashley L

    2014-01-01

    Cationic antimicrobial (host defense) peptides (CAPs) are able to kill microorganisms and cancer cells, leading to their consideration as novel candidate therapeutic agents in human medicine. CAPs can physically associate with anionic membrane structures, such as those found on cancer cells, causing pore formation, intracellular disturbances, and leakage of cell contents. In contrast, normal cells are less negatively-charged and are typically not susceptible to CAP-mediated cell death. Because the interaction of CAPs with cells is based on charge properties rather than cell proliferation, both rapidly dividing and quiescent cancer cells, as well as multidrug-resistant cancer cells, are targeted by CAPs, making CAPS potentially valuable as anti-cancer agents. CAPs often exist as families of peptides with slightly different amino acid sequences. In addition, libraries of synthetic peptide variants based on naturally occurring CAP templates can be generated in order to improve upon their action. High-throughput screens are needed to quickly and efficiently assess the suitability of each CAP variant. Here we present the methods for assessing CAP-mediated cytotoxicity against cancer cells (suspension and adherent) and untransformed cells (measured using the tritiated thymidine-release or MTT assay), and for discriminating between cell death caused by necrosis (measured using lactate dehydrogenase- or (51)Cr-release assays), or apoptosis and necrosis (single-stranded DNA content measured by flow cytometry). In addition the clonogenic assay, which assesses the ability of single transformed cells to multiply and produce colonies, is described. PMID:24146403

  7. Antimicrobial susceptibility of Lactobacillus species isolated from commercial ethanol plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial contamination of commercial fermentation cultures is a common and costly problem to the fuel ethanol industry. Antimicrobials such as virginiamycin (VIR) and penicillin (PEN) are frequently used to control contamination but there are little data available on the susceptibility of bacteria...

  8. Search for antisickling agents from plants

    PubMed Central

    Dash, Bisnu Prasad; Archana, Y.; Satapathy, Nibarana; Naik, Soumendra Kumar

    2013-01-01

    The sickle cell disease is fatal in nature. Thousands of children are dying off due to this health problem throughout the globe. Due to the rapid development of diagnosis and clinical managements such patients are living up to a respectable age. But as there is no permanent cure the patients are suffering from bone and joint pain, jaundice, hepato-splenomegaly, chronic infections etc. The main physiological complicacy is due to the polymerization of sickle hemoglobin (HbS), (sickling process) inside the red blood cell (RBC) of these patients during deoxygenating state. The change of RBC from spherical to sickle shape is due to the polymerization of mutant hemoglobin (HbS) inside the RBC and membrane distortion during anoxic condition. The mechanism and the process of sickling are very complex and multifactor in nature. To get rid from such complicacies it is necessary to suitably and accurately stop the sickling of RBC of the patients. The potential anti-sickling agents either from natural sources and/or synthetic molecules may be helpful for reducing the clinical morbidity of the patients. A lot of natural compounds from plant extracts have been tried by several workers in recent past. Most of the studies are based on in vitro red cell sickling studies and their mode of action has not been properly understood. Although, few studies have been in vivo in nature pertaining to transgenic sickle animal model, there is paucity of data on the human studies. The result of such studies although has shown some degree of success, a promising anti-sickling agent is yet to be established. PMID:23922457

  9. The use of the antimicrobial peptide piscidin (PCD)-1 as a novel anti-nociceptive agent.

    PubMed

    Chen, Wu-Fu; Huang, Shi-Ying; Liao, Chang-Yi; Sung, Chun-Sung; Chen, Jyh-Yih; Wen, Zhi-Hong

    2015-06-01

    The antimicrobial peptide piscidin (PCD)-1 has been reported to have antibacterial and immunomodulatory functions. Here, we investigated the anti-neuropathic properties of PCD-1, in order to determine its potential as a compound to alleviate pain. Treatment with PCD-1 suppressed the inflammatory proteins COX-2 and iNOS in murine macrophage (RAW264.7) and microglial (BV2) cell lines stimulated by lipopolysaccharide (LPS). For studies of the effect of PCD-1 in vivo, mononeuropathy in rats was induced by chronic constriction injury (CCI), and the resulting anti-nociceptive behaviors were compared between CCI controls and CCI rats given intrathecal injections of PCD-1. Much like gabapentin, PCD-1 exerts anti-nociceptive effects against thermal hyperalgesia, with a median effective dose (ED50) of 9.5 ?g in CCI rats. In CCI rats, PCD-1 exerted effects against mechanical and cold allodynia, thermal hyperalgesia, and weight-bearing deficits. Furthermore, CCI-mediated activation of microglia and astrocytes in the dorsal horn of the lumbar spinal cord were decreased by PCD-1. In addition, PCD-1 suppressed up-regulation of interleukin-1? (IL-1?) and phosphorylated mammalian target of rapamycin (phospho-mTOR) in CCI rats. Finally, CCI-induced down-regulation of transforming growth factor-?1 (TGF-?1) in rats was attenuated by injection of PCD-1. Taken together, the present findings demonstrate that the marine antimicrobial peptide PCD-1 has anti-nociceptive effects, and thus may have potential for development as an alternative pain-alleviating agent. PMID:25890701

  10. Synthesis and structure-activity relationship of N-(cinnamyl) chitosan analogs as antimicrobial agents.

    PubMed

    Badawy, Mohamed E I; Rabea, Entsar I

    2013-06-01

    The current study focuses on the preparation of new N-(cinnamyl) chitosan derivatives as antimicrobial agents against nine types of crop-threatening pathogens. Chitosan was reacted with a set of aromatic cinnamaldehyde analogs by reductive amination involving formation of the corresponding imines, followed by reduction with sodium borohydride to produce N-(cinnamyl) chitosan derivatives. The structural characterization was confirmed by (1)H and (13)C NMR spectroscopy and the degrees of substitution ranged from 0.08 to 0.28. The antibacterial activity was evaluated in vitro by minimum inhibitory concentration (MIC) against Agrobacterium tumefaciens and Erwinia carotovora. A higher inhibition activity was obtained by N-(?-methylcinnamyl) chitosan with MIC 1275 and 1025 mg/L against A. tumefaciens and E. carotovora, respectively followed by N-(o-methoxycinnamyl) chitosan (MIC=1925 and 1550 mg/L, respectively). The antifungal assessment was evaluated in vitro by mycelial radial growth technique against Alternaria alternata, Botrytis cinerea, Botryodiplodia theobromae, Fusarium oxysporum, Fusarium solani, Pythium debaryanum and Phytophthora infestans. N-(o-methoxycinnamyl) chitosan showed the highest antifungal activity among the tested compounds against the airborne fungi A. alternata, B. cinerea, Bd. theobromae and Ph. infestans with EC?? of 672, 796, 980 and 636 mg/L, respectively. However, N-(p-N-dimethylaminocinnamyl) chitosan was the most active against the soil born fungi F. oxysporum, F. solani and P. debaryanum (EC50=411, 566 and 404 mg/L, respectively). On the other hand, the chitosan derivatives caused significant reduction in spore germination of A. alternata, B. cinerea, F. oxysporum and F. solani compared to chitosan and the reduction in spore germination was higher than that of the mycelia inhibition. The synthesis and characterization of new chitosan derivatives are ongoing in our laboratory aiming to obtain derivatives with higher antimicrobial activities and used as safe alternatives to harmful microbicides. PMID:23511055

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  12. Pharmacodynamics of Antimicrobials against Mycoplasma mycoides mycoides Small Colony, the Causative Agent of Contagious Bovine Pleuropneumonia

    PubMed Central

    Mitchell, John D.; McKellar, Quintin A.; McKeever, Declan J.

    2012-01-01

    Background Mycoplasma mycoides subspecies mycoides Small Colony (MmmSC) is the causative agent of Contagious Bovine Pleuropneumonia (CBPP), a disease of substantial economic importance in sub-Saharan Africa. Failure of vaccination to curtail spread of this disease has led to calls for evaluation of the role of antimicrobials in CBPP control. Three major classes of antimicrobial are effective against mycoplasmas, namely tetracyclines, fluoroquinolones and macrolides. Therefore, the objectives of this study were to determine the effector kinetics of oxytetracycline, danofloxacin and tulathromycin against two MmmSC field strains in artificial medium and adult bovine serum. Methods Minimum inhibitory concentrations (MIC) were determined for oxytetracycline, danofloxacin and tulathromycin against MmmSC strains B237 and Tan8 using a macrodilution technique, and time-kill curves were constructed for various multiples of the MIC over a 24 hour period in artificial medium and serum. Data were fitted to sigmoid Emax models to obtain 24 hour-area under curve/MIC ratios for mycoplasmastasis and, where appropriate, for mycoplasmacidal activity and virtual mycoplasmal elimination. Results Minimum inhibitory concentrations against B237 were 20-fold higher, 2-fold higher and approximately 330-fold lower in serum than in artificial medium for oxytetracycline, danofloxacin and tulathromycin, respectively. Such differences were mirrored in experiments using Tan8. Oxytetracycline was mycoplasmastatic against both strains in both matrices. Danofloxacin elicited mycoplasmacidal activity against B237 and virtual elimination of Tan8; similar maximum antimycoplasmal effects were observed in artificial medium and serum. Tulathromycin effected virtual elimination of B237 but was mycoplasmastatic against Tan8 in artificial medium. However, this drug was mycoplasmastatic against both strains in the more physiologically relevant matrix of serum. Conclusions Oxytetracycline, danofloxacin and tulathromycin are all suitable candidates for further investigation as potential treatments for CBPP. This study also highlights the importance of testing drug activity in biological matrices as well as artificial media. PMID:22952911

  13. Susceptibility of bacterial etiological agents to commonly-used antimicrobial agents in children with sepsis at the Tamale Teaching Hospital

    PubMed Central

    2013-01-01

    Background Bloodstream infections in neonates and infants are life-threatening emergencies. Identification of the common bacteria causing such infections and their susceptibility patterns will provide necessary information for timely intervention. This study is aimed at determining the susceptibilities of bacterial etiological agents to commonly-used antimicrobial agents for empirical treatment of suspected bacterial septicaemia in children. Methods This is a hospital based retrospective analysis of blood cultures from infants to children up to 14 years of age with preliminary diagnosis of sepsis and admitted to the Neonatal Intensive Care Unit (NICU) and Paediatric Wards of the Teaching Hospital Tamale from July 2011 to January 2012. Results Out of 331 blood specimens cultured, the prevalence of confirmed bacterial sepsis was 25.9% (86/331). Point prevalence for confirmed cases from NICU was 44.4% (28/63) and 21.6% (58/268) from the Paediatric ward. Gram positive cocci (GPC) were the predominant isolates with Coagulase positive (32.2%) and Coagulase-negative (28.7%) Staphylococci accounting for 60.9% of the total isolates. Gram negative rods (GNR) comprised 39.1% of all isolates with Klebsiella, E.coli and Salmonella being the most common organisms isolated. Klebsiella was the most frequent GNR from the NICU and Salmonella typhi was predominantly isolated from the paediatric ward. Acinetobacter showed 100.0% susceptibility to Ceftriaxone and Cefotaxime but was resistant (100.0%) to Ampicillin, Tetracycline and Cotrimoxazole. Escherichia coli and Klebsiella were 80.0% and 91.0% susceptible to Ceftriaxone and Cefotaxime respectively. Klebsiella species showed 8.3% susceptibility to Tetracycline but was resistant to Ampicillin and Cotrimoxazole. Escherichia coli showed 40.0% susceptibility to Ampicillin, Chloramphenicol and Cotrimoxazole; 20.0% susceptibility to Tetracycline and 80.0% susceptible to Gentamicin and Cefuroxime. Coagulase negative Staphylococci was susceptible to Gentamicin (72.0%) but Coagulase positive Staphylococci showed intermediate sensitivity to Gentamicin (42.9%). Conclusion Coagulase Negative, Coagulase Positive Staphylococci, Salmonella and Klebsiella were the aetiological agents of bloodstream infection among children at TTH. While gram-positive and gram-negative bacteria showed low susceptibility to Ampicillin, Tetracycline and Cotrimoxazole, the GNR were susceptible to Gentamicin and third-generation cephalosporins. PMID:23419199

  14. Antimicrobial activity of essential oils from plants against selected pathogenic and saprophytic microorganisms.

    PubMed

    Elgayyar, M; Draughon, F A; Golden, D A; Mount, J R

    2001-07-01

    The beneficial health effects of extracts from many types of plants that are used as seasoning agents in foods and beverages have been claimed for centuries. The purpose of this study was to examine the effectiveness of selected herb and spice essential oils for control of growth and survival of microorganisms. Inhibition of growth was tested by the paper disc agar diffusion method. Antibiotic susceptibility discs were used as control. Minimum lethal concentration (MLC) was determined by the tube dilution method. Essential oils from anise, angelica, basil, carrot, celery, cardamom, coriander, dill weed, fennel, oregano, parsley, and rosemary were evaluated. Inhibition ranged from complete with oregano to no inhibition with carrot oil for each of the test strains that included: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O:157:H7, Yersinia enterocolitica, Pseudomonas aeruginosa, Lactobacillus plantarum, Aspergillus niger, Geotrichum, and Rhodotorula. Oregano essential oil showed the greatest inhibition (zone, > or = 70 to 80 mm) (MLC, approximately 8 ppm). Coriander and basil were also highly inhibitory (MLC, approximately 25 to 50 ppm) to E. coli O:157:H7 and to the other bacteria and fungi tested. Anise oil was not particularly inhibitory to bacteria (inhibition zone, approximately 25 mm); however, anise oil was highly inhibitory to molds. Because some of the herbal and spice essential oils are highly inhibitory to selected pathogenic and spoilage microorganisms, they may provide alternatives and supplements to conventional antimicrobial additives in foods. PMID:11456186

  15. In vitro antimicrobial activity of Romanian medicinal plants hydroalcoholic extracts on planktonic and adhered cells.

    PubMed

    Stanciuc, A M; Gaspar, A; Moldovan, L; Saviuc, C; Popa, M; M?ru?escu, L

    2011-01-01

    The aim of this study was to assess the antibacterial and antifungal potential of some Romanian medicinal plants, arnica--Arnica montana, wormwood--Artemisia absinthium and nettle--Urtica dioica. In order to perform this antimicrobial screening, we obtained the vegetal extracts and we tested them on a series of Gram-positive and Gram-negative bacteria, and also against two fungal strains. The vegetal extracts showed antimicrobial activity preferentially directed against the planktonic fungal and bacterial growth, while the effect against biofilm formation and development was demonstrated only against S. aureus and C. albicans. Our in vitro assays indicate that the studied plant extracts are a significant source of natural alternatives to antimicrobial therapy, thus avoiding antibiotic therapy, the use of which has become excessive in recent years. PMID:21717806

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

    PubMed Central

    Upadhyaya, Indu; Kollanoor-Johny, Anup

    2014-01-01

    The emergence of antibiotic resistance in pathogenic bacteria has led to renewed interest in exploring the potential of plant-derived antimicrobials (PDAs) as an alternative therapeutic strategy to combat microbial infections. Historically, plant extracts have been used as a safe, effective, and natural remedy for ailments and diseases in traditional medicine. Extensive research in the last two decades has identified a plethora of PDAs with a wide spectrum of activity against a variety of fungal and bacterial pathogens causing infections in humans and animals. Active components of many plant extracts have been characterized and are commercially available; however, research delineating the mechanistic basis of their antimicrobial action is scanty. This review highlights the potential of various plant-derived compounds to control pathogenic bacteria, especially the diverse effects exerted by plant compounds on various virulence factors that are critical for pathogenicity inside the host. In addition, the potential effect of PDAs on gut microbiota is discussed. PMID:25298964

  17. Antimicrobials Treatment

    NASA Astrophysics Data System (ADS)

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

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

  18. Occurrence of antimicrobials in the final effluents of wastewater treatment plants in Canada.

    PubMed

    Miao, Xiu-Sheng; Bishay, Farida; Chen, Mei; Metcalfe, Chris D

    2004-07-01

    To investigate the occurrence of antimicrobials in the final effluents from wastewater treatment plants (WWTPs) in Canada, analytical methods were developed or modified from previously described methods using solid-phase extraction followed by liquid chromatography-electrospray ionization tandem mass spectrometry. Thirty-one antimicrobials from the macrolide, quinolone, quinoxaline dioxide, sulfonamide, and tetracycline classes were investigated in the final (treated) effluents from eight WWTPs, located in five Canadian cities. Ciprofloxacin, clarithromycin, erythromycin-H20, ofloxacin, sulfamethoxazole, sulfapyridine, and tetracycline were frequently detected in the effluents. The detection of sulfapyridine in effluents is the first report of this compound in environmental samples. Antimicrobials used exclusively for veterinary applications or treatment of livestock, such as carbadox, olaquindox, and chlortetracycline were not detected in the WWTP final effluents. There appear to be differences in the relative concentrations of antimicrobials detected in WWTP final effluents in Canada relative to concentrations reported previously in northern Europe, particularly for quinolone and sulfonamide compounds. These data may reflect differences in prescription patterns in Canada and northern Europe. The antimicrobials frequently detected in WWTP effluents appear to be those prescribed heavily in Canada for medical applications, and these compounds should be considered priority compounds for monitoring in surface water near WWTP discharges. The concentrations of antimicrobials detected in WWTP final effluents did not exceed 1 microg/L; levels that are unlikely to affect the growth and survival of aquatic organisms. PMID:15296302

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

    PubMed Central

    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

  20. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, July 2008, p. 26162625 Vol. 52, No. 7 0066-4804/08/$08.00 0 doi:10.1128/AAC.01643-07

    E-print Network

    Dever, Jennifer A.

    ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, July 2008, p. 2616­2625 Vol. 52, No. 7 0066-4804/08/$08.00 0 Cassone,2 and Alessandra Carattoli2 * National Research Council, Segrate, Milan 20090, Italy1 ; Department

  1. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Feb. 2009, p. 756764 Vol. 53, No. 2 0066-4804/09/$08.00 0 doi:10.1128/AAC.00607-08

    E-print Network

    Higgins, Darren

    ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Feb. 2009, p. 756­764 Vol. 53, No. 2 0066-4804/09/$08.00 0 cellular processes required for intracellular infection can be obtained. This approach also has the benefit

  2. Antimicrobial Studies on Selected Medicinal Plants, Erode Region, Tamilnadu, India

    Microsoft Academic Search

    C. Chitravadivu; S. Manian; K. Kalaichelvi

    3 Abstract: Medicinal plants contribute in human health care system. Most of the plants utilized by villag e peoples as a folk medicine. Now we are turned in to medicinal plant analysis of active compounds and conservation aspect. In the present study we had select the four important medicinal plants in the Erode district. Such plants are widely used in

  3. The Antimicrobial Properties of Cedar Leaf (Thuja plicata) Oil; A Safe and Efficient Decontamination Agent for Buildings

    PubMed Central

    Hudson, James; Kuo, Michael; Vimalanathan, Selvarani

    2011-01-01

    Cedar leaf oil (CLO), derived from the Western red cedar, Thuja plicata, was evaluated as a safe and acceptable broad spectrum antimicrobial agent, with a view to its potential applications in buildings, including the alleviation of sick building syndrome. Various Gram-positive and Gram-negative human bacteria, and two fungal organisms, all known to be common environmental sources of potential infection, were selected and tested quantitatively, and all of them were found to be susceptible to CLO liquid and vapor. Bacterial spores and Aspergillus niger were sensitive, although less so than the vegetative bacteria. Similar tests with cultured human lung cells showed that continuous exposure to CLO vapor for at least 60 minutes was not toxic to the cells. Based on these results, CLO shows promise as a prospective safe, green, broad-spectrum anti-microbial agent for decontamination of buildings. PMID:22408584

  4. The antimicrobial properties of cedar leaf (Thuja plicata) oil; a safe and efficient decontamination agent for buildings.

    PubMed

    Hudson, James; Kuo, Michael; Vimalanathan, Selvarani

    2011-12-01

    Cedar leaf oil (CLO), derived from the Western red cedar, Thuja plicata, was evaluated as a safe and acceptable broad spectrum antimicrobial agent, with a view to its potential applications in buildings, including the alleviation of sick building syndrome. Various Gram-positive and Gram-negative human bacteria, and two fungal organisms, all known to be common environmental sources of potential infection, were selected and tested quantitatively, and all of them were found to be susceptible to CLO liquid and vapor. Bacterial spores and Aspergillus niger were sensitive, although less so than the vegetative bacteria. Similar tests with cultured human lung cells showed that continuous exposure to CLO vapor for at least 60 minutes was not toxic to the cells. Based on these results, CLO shows promise as a prospective safe, green, broad-spectrum anti-microbial agent for decontamination of buildings. PMID:22408584

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. Antimicrobial activities of some selected traditional Ethiopian medicinal plants used in the treatment of skin disorders

    Microsoft Academic Search

    Hailu Tadeg; Endris Mohammed; Kaleab Asres; Tsige Gebre-Mariam

    2005-01-01

    Hydroalcoholic extracts of eight species of medicinal plants, namely, Acokanthera schimperi (Apocynaceae), Calpurnia aurea (Leguminosae), Kalanchoe petitiana (Crassulaceae), Lippia adoensis (Verbenaceae), Malva parviflora (Malvaceae), Olinia rochetiana (Oliniaceae), Phytolacca dodecandra (Phytolaccaceae) and Verbascum sinaiticum (Scrophulariaceae), traditionally used in the treatment of various skin disorders were screened for antimicrobial activity against different strains of bacteria and fungi which are known to cause

  7. Mechanical, Barrier and Antimicrobial Properties of Apple Puree Edible Films Containing Plant Essential Oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edible films, as carriers of antimicrobial compounds, constitute an approach for incorporating plant essential oils onto fresh-cut fruit surfaces. The effect against Escherichia coli O157:H7 of oregano, cinnamon and lemongrass oils in apple puree film-forming solution (APFFS) and in an edible film ...

  8. In Vitro Susceptibilities of 400 Spanish Isolates of Neisseria gonorrhoeae to Gemifloxacin and 11 Other Antimicrobial Agents

    Microsoft Academic Search

    S. Berron; J. A. Vazquez; M. J. Gimenez; L. de la Fuente; L. Aguilar

    2000-01-01

    The in vitro activity of gemifloxacin versus those of 11 other antimicrobial agents against 400 strains of Neisseria gonorrhoeae was determined by microdilution with supplemented GC agar. A total of 37.5% of the strains were b-lactamase positive. A total of 70 and 6.4% of the b-lactamase-negative strains exhibited intermediate and high-level penicillin resistance, respectively. Ceftriaxone and gemifloxacin were the most

  9. Synthesis and biological evaluation of 2-aminobenzamide derivatives as antimicrobial agents: opening/closing pharmacophore site.

    PubMed

    Mabkhot, Yahia N; Al-Majid, Abdullah M; Barakat, Assem; Al-Showiman, Salim S; Al-Har, Munirah S; Radi, Smaail; Naseer, Muhammad Moazzam; Hadda, Taibi B

    2014-01-01

    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. PMID:24663060

  10. Cationic antitrypanosomal and other antimicrobial agents in the therapy of experimental Pneumocystis carinii pneumonia.

    PubMed Central

    Walzer, P D; Kim, C K; Foy, J; Linke, M J; Cushion, M T

    1988-01-01

    Cationic compounds used in the treatment of veterinary African trypanosomiasis have structural properties similar to those of pentamidine, which has been used in the therapy of human trypanosomiasis and infection with Pneumocystis carinii. We have compared the activities of these drugs and other antimicrobial agents in an immunosuppressed rat model of P. carinii pneumonia. Diminazene, imidocarb, amicarbalide, quinapyramine, and isometamidium showed efficacy greater than or equal to that of pentamidine in the therapy of P. carinii infection, whereas ethidium and methylglyoxal bis(guanylhydrazone) were only slightly active against the organism. Diminazene and pentamidine also exhibited comparable efficacy in P. carinii prophylaxis, alpha-Difluoromethylornithine (DFMO), a polyamine inhibitor, was ineffective therapy when used alone and did not improve the effectiveness of pentamidine or diminazene. Quinine, quinidine, quinacrine, chlorpromazine, spiramycin, Pentostam, Astiban, dehydroemetine, ampicillin, gentamicin, chloramphenicol, and spectinomycin also showed little or no activity against the organism. Thus, in this model anti-P. carinii activity appears to be a common property of veterinary cationic trypanocidal compounds. This should be important in studying structure-activity relationships and in developing new drugs for the treatment of P. carinii infection in humans. PMID:3137861

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

    PubMed Central

    Mabkhot, Yahia N.; Al-Majid, Abdullah M.; Barakat, Assem; Al-Showiman, Salim S.; Al-Har, Munirah S.; Radi, Smaail; Naseer, Muhammad Moazzam; Hadda, Taibi B.

    2014-01-01

    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. PMID:24663060

  12. Oxidative degradation study on antimicrobial agent ciprofloxacin by electro-Fenton process: kinetics and oxidation products.

    PubMed

    Yahya, Muna Sh; Oturan, Nihal; El Kacemi, Kacem; El Karbane, Miloud; Aravindakumar, C T; Oturan, Mehmet A

    2014-12-01

    Oxidative degradation of the antimicrobial agent ciprofloxacin hydrochloride (CIP) has been investigated using electro-Fenton (EF) treatment with a constant current in the range 60-500 mA. The process generates highly oxidant species OH in situ via electrochemically monitored Fenton reaction. The EF experiments were performed using cells with a carbon felt cathode and Pt anode. Effect of applied current and catalyst concentration on the kinetics of oxidative degradation and mineralization efficiency have been investigated. Degradation of CIP followed pseudo-first order reaction kinetics. The rate constant of the oxidation of CIP by OH has been determined to be (1.01 ± 0.14) × 10(10) M(-1) s(-1) by using competitive kinetics method. An optimum current of 400 mA and a catalyst concentration of Fe(2+) at 0.1mM are found to be optimal for an effective degradation of CIP under our operating conditions. A remarkably high degree of mineralization (>94%) was obtained at 6h of treatment under these conditions. A number of stable intermediate products have been identified using HPLC and LC-MS/MS analyses. Based on the identified reaction intermediates, a plausible reaction pathway was proposed for the mineralization process. The high degree of mineralization obtained in this work highlights the potential application of EF process in the efficient removal of fluoroquinolone based drugs in aqueous medium. PMID:25201488

  13. VINEGAR AS AN ANTIMICROBIAL AGENT FOR CONTROL OF Candida spp. IN COMPLETE DENTURE WEARERS

    PubMed Central

    Pinto, Telma Maria Silva; Neves, Ana Christina Claro; Leão, Mariella Vieira Pereira; Jorge, Antonio Olavo Cardoso

    2008-01-01

    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. PMID:19082396

  14. Antimicrobial activity of some coumarin containing herbal plants growing in Finland

    Microsoft Academic Search

    Tiina Ojala; Susanna Remes; Pasi Haansuu; Heikki Vuorela; Raimo Hiltunen; Kielo Haahtela; Pia Vuorela

    2000-01-01

    Antimicrobial screening against selected Gram-positive and Gram-negative bacteria, yeasts, mold, as well as plant pathogenic fungi, with emphasis on method optimization was carried out on methanol extracts prepared from seven plants grown in Finland. Sensitivity to the extracts was found to vary considerably among the micro-organisms, the extract from Petroselinum crispum and Ruta graveolens showing the highest toxicity against Rhizoctonia

  15. Rhamnolipids as emulsifying agents for essential oil formulations: Antimicrobial effect against Candidaalbicans and methicillin-resistant Staphylococcus aureus.

    PubMed

    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. PMID:25269010

  16. Screening of some Indian medicinal plants for their antimicrobial properties

    Microsoft Academic Search

    Iqbal Ahmad; Zafar Mehmood; Faiz Mohammad

    1998-01-01

    A total of 82 Indian medicinal plants traditionally used in medicines were subjected to preliminary antibacterial screening against several pathogenic and opportunistic microorganisms. Aqueous, hexane and alcoholic extracts of each plant were tested for their antibacterial activity using agar well diffusion method at sample concentration of 200 mg\\/ml. The results indicated that out of 82 plants, 56 exhibited antibacterial activity

  17. Susceptibilities of Listeria species isolated from food to nine antimicrobial agents.

    PubMed

    Franco Abuín, C M; Quinto Fernández, E J; Fente Sampayo, C; Rodríguez Otero, J L; Domínguez Rodríguez, L; Cepeda Sáez, A

    1994-07-01

    The agar dilution method was used to determine the activities of gentamicin, erythromycin, streptomycin, chloramphenicol, ampicillin, sulfamethazine, cephalothin, penicillin G, and tetracycline against 73 strains belonging to the genus Listeria (L. innocua, L. seeligeri, and L. monocytogenes). All strains were isolated from raw milk, cheese, the dairy processing plant, poultry, and the poultry slaughterhouse. Gentamicin, ampicillin, and erythromycin, of which the MICs for 90% of the strains tested for all three species were < or = 5.96 micrograms/ml, were found to be the most active agents studied. Most of the L. innocua strains isolated from poultry and the poultry slaughterhouse were resistant to tetracycline. PMID:7979303

  18. The continuing search for antitumor agents from higher plants

    PubMed Central

    Pan, Li; Chai, Heebyung; Kinghorn, A. Douglas

    2009-01-01

    Plant secondary metabolites and their semi-synthetic derivatives continue to play an important role in anticancer drug therapy. In this short review, selected single chemical entity antineoplastic agents from higher plants that are currently in clinical trials as cancer chemotherapy drug candidates are described. These compounds are representative of a wide structural diversity. In addition, the approaches taken toward the discovery of anticancer agents from tropical plants in the laboratory of the authors are summarized. The successful clinical utilization of cancer chemotherapeutic agents from higher plants has been evident for about half a century, and, when considered with the promising pipeline of new plant-derived compounds now in clinical trials, this augurs well for the continuation of drug discovery research efforts to elucidate additional candidate substances of this type. PMID:20228943

  19. Sensitivity of Staphylococcus aureus and Streptococcus pyogenes isolated from skin infections in 1992 to antimicrobial agents.

    PubMed

    Nishijima, S; Namura, S; Kawai, S; Akamatsu, H; Asada, Y; Kawabata, S

    1994-04-01

    We studied the efficacy of antimicrobial agents against Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes) isolated from skin infections in 1992. For S. aureus, we measured the minimum inhibitory concentrations (MICs) of the following 10 drugs: methicillin (DMPPC), cefaclor (CCL), gentamicin (GM), erythromycin (EM), clindamycin (CLDM), minocycline (MINO), vancomycin (VAN), fusidic acid (FA), ofloxacin (OFLX) and nadifloxacin (NDFX); for S. pyogenes, we determined the MICs of the following 9 drugs: ampicillin (ABPC), amoxicillin (AMPC), cefpodoxime proxetil (CPDX-PR), erythromycin (EM), clindamycin (CLDM), minocycline (MINO), norfloxacin (NFLX), of loxacin (OFLX) and nadifloxacin (NDFX). These drugs are frequently used to treat skin infections, either systemically or topically. NDFX is a new synthetic fluoroquinolone, recently developed for use as a topical acne medication in Japan. It is used NDFX for acne, but not for skin infections. There were no strains of S. aureus resistant to NDFX, VAN or FA. The resistance (> or = 12.5 micrograms/ml) of S. aureus was highest to GM and lowest to OFLX. Four strains of methicillin-resistant (> or = 12.5 micrograms/ml) S. aureus (MRSA) were found. In contrast, no resistant strains of S. pyogenes were found except to MINO. Only two strains of S. pyogenes were susceptible to MINO. The sensitivity of S. pyogenes to ABPC, AMPC, CPDX-PR, EM and CLDM was very good. All the strains were susceptible at a MIC below > or = 0.05 microgram/ml. However, the S. pyogenes strains were not very sensitive to the new quinolones, especially NFLX. We concluded that penicillins, cephalosporins and macrolides are still effective against streptococcal infections.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8056894

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

    PubMed

    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. PMID:21858429

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

    PubMed

    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. PMID:22806922

  2. Antimicrobial Agent of Susceptibilities and Antiseptic Resistance Gene Distribution among Methicillin-Resistant Staphylococcus aureus Isolates from Patients with Impetigo and Staphylococcal Scalded Skin Syndrome

    Microsoft Academic Search

    Norihisa Noguchi; Hidemasa Nakaminami; Setsuko Nishijima; Ichiro Kurokawa; Hiromu So; Masanori Sasatsu

    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

  3. Plant antimicrobial peptides: an overview of SuperSAGE transcriptional profile and a functional review.

    PubMed

    Kido, E A; Pandolfi, V; Houllou-Kido, L M; Andrade, P P; Marcelino, F C; Nepomuceno, A L; Abdelnoor, R V; Burnquist, W L; Benko-Iseppon, A M

    2010-05-01

    Defensin, thionin and lipid transfer protein (LTP) gene families, which antimicrobial activity has an attractive use in protein engineering and transgenic production of agronomical important plants, have been here functionally reviewed. Also, a transcriptional overview of a set of plant SuperSAGE libraries and analysis looking for 26 bp tags possibly annotated for those families is presented. Tags differentially expressed (p = 0.05) or constitutively transcribed were identified from leaves or roots SuperSAGE libraries from important Brazilian plant species [cowpea (Vigna unguiculata (L.) Walp.), soybean (Glycine max (L.) Merr.) and modern sugarcane hybrids (Saccharum spp.)] submitted to abiotic [salt (100 mM NaCl) or drought] or biotic stresses [fungus inoculation (Phakopsora pachyrhizi; Asiatic Soyben Rust phytopathogen)]. The diverse transcriptional patterns observed, probably related to the variable range of targets and functions involved, could be the first step to unravel the antimicrobial peptide world and the plant stress response relationship. Moreover, SuperSAGE opens the opportunity to find some SNPs or even rare transcript that could be important on plant stress resistance mechanisms. Putative defensin or LTP identified by SuperSAGE following a specific plant treatment or physiological condition could be useful for future use in genetic improvement of plants. PMID:20088771

  4. Nanopores, megatonnes, and milliseconds : exploring engineered peptides as antimicrobial, carbon-capture,and biocatalytic agents

    E-print Network

    Barbero, Roberto Juan

    2012-01-01

    This work investigates the roles that peptides play in the fields of antimicrobials, surface functionalization, carbon capture, and biocatalysis. The results demonstrate that peptides, sometimes dismissed for their lack ...

  5. Screening of plant Macaranga peltata for its antioxidant, antimicrobial and cytotoxicity activity

    Microsoft Academic Search

    Meenakshi Verma; P. V. Raj; H. R. Chandrasekhar; J. V. Rao; N. Udupa

    2009-01-01

    The plant Macaranga peltata (Euphorbiaceae) leaves and stem bark was tested for its in vitro antioxidant, antimicrobial and cytotoxicity activity using different methods. In vitro anti oxidant activity stem bark extract showed inhibitory concentration 50% (IC50) value of 10.13 than the leaf extract IC50 = 14.85 for DPPH assay. Standard ascorbic acid showed IC50 = 7.28. For ABTS free radical

  6. Self-assembled cationic peptide nanoparticles as an efficient antimicrobial agent

    Microsoft Academic Search

    Lihong Liu; Kaijin Xu; Huaying Wang; P. K. Jeremy Tan; Weimin Fan; Subbu S. Venkatraman; Lanjuan Li; Yi-Yan Yang

    2009-01-01

    Antimicrobial cationic peptides are of interest because they can combat multi-drug-resistant microbes. Most peptides form ?-helices or ?-sheet-like structures that can insert into and subsequently disintegrate negatively charged bacterial cell surfaces. Here, we show that a novel class of core–shell nanoparticles formed by self-assembly of an amphiphilic peptide have strong antimicrobial properties against a range of bacteria, yeasts and fungi.

  7. Antimicrobial activities of some selected traditional Ethiopian medicinal plants used in the treatment of skin disorders.

    PubMed

    Tadeg, Hailu; Mohammed, Endris; Asres, Kaleab; Gebre-Mariam, Tsige

    2005-08-22

    Hydroalcoholic extracts of eight species of medicinal plants, namely, Acokanthera schimperi (Apocynaceae), Calpurnia aurea (Leguminosae), Kalanchoe petitiana (Crassulaceae), Lippia adoensis (Verbenaceae), Malva parviflora (Malvaceae), Olinia rochetiana (Oliniaceae), Phytolacca dodecandra (Phytolaccaceae) and Verbascum sinaiticum (Scrophulariaceae), traditionally used in the treatment of various skin disorders were screened for antimicrobial activity against different strains of bacteria and fungi which are known to cause different types of skin infections. The tests were carried out using agar well diffusion method at three concentration levels (100, 50 and 25mg/ml) of the crude extracts. The MICs of the crude extracts of Lippia adoensis and Olinia rochetiana were determined by agar dilution method. Furthermore, the powdered leaves of Lippia adoensis and Olinia rochetiana were fractionated into different solvents of wide ranging polarity and the resulting fractions were screened for antimicrobial activity against the same organisms. Of all the plants tested, Lippia adoensis and Olinia rochetiana were found to be the most active species against bacterial and fungal strains, respectively. In addition, almost all species of plants were found to have activity on at least one microbial strain. The antimicrobial activity profile also showed that Staphylococcus aureus and Trichophyton mentagrophytes were the most susceptible bacterial and fungal strains, respectively. The results indicate the potential of these herbal drugs in treating microbial infections of the skin, thus, justifying their claimed uses in the treatment of various skin disorders, the majority of which are of infectious origin. PMID:16054532

  8. Screening of selected medicinal plants of Nepal for antimicrobial activities

    Microsoft Academic Search

    R. S. Taylor; N. P. Manandhar; G. H. N. Towers

    1995-01-01

    In an ethnopharmacological screening of selected medicinal plants used in Nepal, methanol extracts from 21 plant species were assayed for activity against 8 strains of bacteria and 5 strains of fungi. Duplicate assays were conducted with and without exposure to UV-A radiation to test for light-activated or light-enhanced activity. All 21 of the extracts showed activity against at least 2

  9. Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

    PubMed Central

    ALCÂNTARA, Cristiane S.; de MACÊDO, Allana F.C.; GURGEL, Bruno C.V.; JORGE, Janaina H.; NEPPELENBROEK, Karin H.; URBAN, Vanessa M.

    2012-01-01

    In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties. Objective This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply). Material and Methods Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37ºC for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers' instructions and stored in distilled water at 37ºC for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (?=0.05) and the failure modes were visually classified. Results No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups. Conclusions Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents. PMID:23329241

  10. Screening of Amazonian plants from the Adolpho Ducke forest reserve, Manaus, state of Amazonas, Brazil, for antimicrobial activity.

    PubMed

    Carneiro, Ana Lúcia Basílio; Teixeira, Maria Francisca Simas; Oliveira, Viviana Maria Araújo de; Fernandes, Ormezinda Celeste Cristo; Cauper, Gláucia Socorro de Barros; Pohlit, Adrian Martin

    2008-02-01

    Tropical forests are species-rich reserves for the discovery and development of antimicrobial drugs. The aim of this work is to investigate the in vitro antimicrobial potential of Amazon plants found within the National Institute on Amazon Research's Adolpho Ducke forest reserve, located in Manaus, state of Amazonas, Brazil. 75 methanol, chloroform and water extracts representing 12 plant species were tested for antimicrobial activity towards strains of Mycobacterium smegmatis, Escherichia coli, Streptococcus sanguis, Streptococcus oralis, Staphylococcus aureus and Candida albicans using the gel-diffusion method. Active extracts were further evaluated to establish minimum inhibitory concentrations (MIC) and antimicrobial profiles using bioautography on normal-phase thin-layer chromatography plates. Diclinanona calycina presented extracts with good antimicrobial activity and S. oralis and M. smegmatis were the most sensitive bacteria. D. calycina and Lacmellea gracilis presented extracts with the lowest MIC (48.8 microg/ml). D. calycina methanol and chloroform leaf extracts presented the best overall antimicrobial activity. All test organisms were sensitive to D. calycina branch chloroform extract in the bioautography assay. This is the first evaluation of the biological activity of these plant species and significant in vitro antimicrobial activity was detected in extracts and components from two species, D. calycina and L. gracilis. PMID:18368234

  11. Ixodes scapularis JAK-STAT pathway regulates tick antimicrobial peptides, thereby controlling the agent of human granulocytic anaplasmosis.

    PubMed

    Liu, Lei; Dai, Jianfeng; Zhao, Yang O; Narasimhan, Sukanya; Yang, Ying; Zhang, Lili; Fikrig, Erol

    2012-10-01

    Ixodes scapularis transmits the agent of human granulocytic anaplasmosis, among other pathogens. The mechanisms used by the tick to control Anaplasma phagocytophilum are not known. We demonstrate that the I. scapularis Janus kinase (JAK)-signaling transducer activator of transcription (STAT) pathway plays a critical role in A. phagocytophilum infection of ticks. The A. phagocytophilum burden increases in salivary glands and hemolymph when the JAK-STAT pathway is suppressed by RNA interference. The JAK-STAT pathway exerts its anti-Anaplasma activity presumably through STAT-regulated effectors. A salivary gland gene family encoding 5.3-kDa antimicrobial peptides is highly induced upon A. phagocytophilum infection of tick salivary glands. Gene expression and electrophoretic mobility shift assays showed that the 5.3-kDa antimicrobial peptide-encoding genes are regulated by tick STAT. Silencing of these genes increased A. phagocytophilum infection of tick salivary glands and transmission to mammalian host. These data suggest that the JAK-STAT signaling pathway plays a key role in controlling A. phagocytophilum infection in ticks by regulating the expression of antimicrobial peptides. PMID:22859824

  12. Antimicrobial Activities of Various Medicinal and Commercial Plant Extracts

    Microsoft Academic Search

    D. Ayfer; Özlem Turgay ERDO

    The antibacterial activities of the alcohol, ethyl acetate, acetone and chloroform extracts of 5 plant species were studied. The extracts of Pimpinella anisum (L.) (anise, aniseed) (seed), Coriandrum sativum (L.) (coriander, cilantro) (seed), Glycyrrhiza glabra (L.) (liquorice) (root), Cinnamomum cassia Blume (cassia bark, Chinese cinnamon) (bark), and Juniperus oxycedrus (L.) (juniper) (seed) were tested in vitro against 13 bacterial species

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

    PubMed Central

    Chan, Lai Wah; Cheah, Emily LC; Saw, Constance LL; Weng, Wanyu; Heng, Paul WS

    2008-01-01

    Background Eight medicinal plants were tested for their antimicrobial and antioxidant activities. Different extraction methods were also tested for their effects on the bioactivities of the medicinal plants. Methods Eight plants, namely Herba Polygonis Hydropiperis (Laliaocao), Folium Murraya Koenigii (Jialiye), Rhizoma Arachis Hypogea (Huashenggen), Herba Houttuyniae (Yuxingcao), Epipremnum pinnatum (Pashulong), Rhizoma Typhonium Flagelliforme (Laoshuyu), Cortex Magnoliae Officinalis (Houpo) and Rhizoma Imperatae (Baimaogen) were investigated for their potential antimicrobial and antioxidant properties. Results Extracts of Cortex Magnoliae Officinalis had the strongest activities against M. Smegmatis, C. albicans, B. subtilis and S. aureus. Boiled extracts of Cortex Magnoliae Officinalis, Folium Murraya Koenigii, Herba Polygonis Hydropiperis and Herba Houttuyniae demonstrated greater antioxidant activities than other tested medicinal plants. Conclusion Among the eight tested medicinal plants, Cortex Magnoliae Officinalis showed the highest antimicrobial and antioxidant activities. Different methods of extraction yield different spectra of bioactivities. PMID:19038060

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

    PubMed

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

    2006-04-01

    The antimicrobial activities of 10 plant species (Voacanga africana, Crepis cameroonica, Plagiostyles africana, Crotalaria retusa, Mammea africana, Lophira lanceolata, Ochna afzelii, Ouratea elongata, Ou. flava and Ou. sulcata), each of which is currently used in the traditional medicine of Cameroon, were investigated in vitro. The activities of a methanol extract of each plant were tested, in disc-diffusion assays, against 37 reference or laboratory strains of seven species of microorganism (Staphylococcus aureus, S. epidermidis, Enterococcus hirae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans). The minimal inhibitory concentrations of each extract were then estimated, against each of the more susceptible microorganisms (i.e. those giving an inhibition zone measuring at least 9 mm in diameter in the disc-diffusion assays), by agar dilution. Although, in the disc-diffusion assays, each of the 10 methanol extracts investigated displayed some degree of antimicrobial activity against at least one species of microorganism, no activity against the Gram-negative bacteria (Es. coli, K. pneumoniae and Ps. aeruginosa) was observed. The extract with the greatest antimicrobial activity was that of Pl. africana (Euphorbiaceae). PMID:16630381

  15. Marine antimicrobial peptide tachyplesin as an efficient nanocarrier for macromolecule delivery in plant and mammalian cells.

    PubMed

    Jain, Aastha; Yadav, Bhoopesh K; Chugh, Archana

    2015-02-01

    Membrane-active peptides can be classified as cell-penetrating peptides and antimicrobial peptides (AMPs) that are known to play interchangeable roles. In this study, this dual behaviour was studied for the marine AMP, tachyplesin. It is a well-established cyclic peptide known to possess antimicrobial properties and was investigated for its cell-penetrating property and cargo delivery ability. Because of its derivation from a marine organism as well as cyclic nature, it has been shown to possess higher stability in vitro. In this study, its internalization as a cell-penetrating peptide was established and characterized in both plant and mammalian systems. It was shown to deliver cargo molecules in both living systems, emerging as an efficient nonviral macromolecule nanocarrier. PMID:25514997

  16. Plant extracts as natural amoebicidal agents.

    PubMed

    Derda, Monika; Hada?, Edward; Thiem, Barbara

    2009-02-01

    Strains of Acanthamoeba sp. constitute a factor contributing to the occurrence of chronic granulomatous amoebic encephalitis, keratitis, pneumonia, as well as inflammations of other organs. Treatment of these diseases is very difficult and not always effective. A majority of these infections have been fatal. The aim of our study was to examine the amoebicidal or amoebistatic activity of plant extracts from Rubus chamaemorus, Pueraria lobata, Solidago virgaurea and Solidago graminifolia. For the purpose of isolation of pharmacologically active substances, we used the aboveground parts of plants, together with flowers, roots and leaves. It was established that extracts from S. virgauera, P. lobata and R. chamaemorus displayed chemotherapeutic properties in vitro in concentrations of approximately 0.01-0.05 mg extract/mL, i.e., in concentrations of 0.350 microg/mL expressed in ellagic acid for R. chamaemorus and 0.053 microg/mL expressed in puerarin for P. lobata. Therapeutic index values is 3.5-20. As a result of in vivo experiments, it was found out that, following therapy using the extracts, animals infected with Acanthamoeba sp. survived for an extended period (2.5-3 times longer). It was determined that plant extracts may be used both externally and internally in the case of a combined therapy for acanthamoebiasis. The tested extracts are not toxic for animals. PMID:19050923

  17. Impact of Feed Supplementation with Antimicrobial Agents on Growth Performance of Broiler Chickens, Clostridium perfringens and Enterococcus Counts, and Antibiotic Resistance Phenotypes and Distribution of Antimicrobial Resistance Determinants in Escherichia coli Isolates

    Microsoft Academic Search

    Moussa S. Diarra; Fred G. Silversides; Fatoumata Diarrassouba; Jane Pritchard; Luke Masson; Roland Brousseau; Claudie Bonnet; Pascal Delaquis; Susan Bach; Brent J. Skura; Edward Topp

    2007-01-01

    The effects of feed supplementation with the approved antimicrobial agents bambermycin, penicillin, sali- nomycin, and bacitracin or a combination of salinomycin plus bacitracin were evaluated for the incidence and distribution of antibiotic resistance in 197 commensal Escherichia coli isolates from broiler chickens over 35 days. All isolates showed some degree of multiple antibiotic resistance. Resistance to tetracycline (68.5%), amoxicillin (61.4%),

  18. Phytochemical composition and in vitro antimicrobial and antioxidant activities of some medicinal plants.

    PubMed

    Jaberian, Hamideh; Piri, Khosro; Nazari, Javad

    2013-01-01

    Different parts of three plants (Primula auriculata, Fumaria vaillantii and Falcaria vulgaris) were extracted with three different solvents to yield 72 crude extracts. The phytochemical analysis (chemical screening, GC-MS) of three plants was investigated for their antioxidant and antibacterial activity using nine Gram-positive and Gram-negative bacteria. The principal antioxidant and antimicrobial components were determined using HPLC with UV detection. All extracts possessed antibacterial activity especially methanolic extracts from flowers of P. auriculata. The DPPH-radical scavenging assay exhibited high antioxidant activities in three plants (more than 80% at 50?g). The F. vulgaris showed high content of carvacrol (29.8%) as main component. The contents of carvacrol and fumaric acid in the methanolic-water extracts were 1119 and 1966mg/l respectively. Our results indicate that these plants would be able to promise sources of natural products with potential antibacterial and antioxidant activity. PMID:23017418

  19. Biodiversity of thermotolerant Bacillus sp. producing biosurfactants, biocatalysts, and antimicrobial agents

    Microsoft Academic Search

    Arda Pakpitcharoena

    Thermotolerant bacteria isolated from soil and water samples taken from 76 hot springs in Thailand were investigated for their biosurfactant, biocatalytic, and antimicrobial properties. DNA samples purified from 148 pure isolates were PCR amplified using primers specific for the 16S rDNA hypervariable region of the genus Bacillus. The DNAPAR phylogenetic tree clearly demonstrated that these isolates were related to Bacillus

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

    PubMed

    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 ?-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. PMID:25515896

  1. Food Antimicrobials Nanocarriers

    PubMed Central

    Blanco-Padilla, Adriana; Soto, Karen M.; Hernández Iturriaga, Montserrat

    2014-01-01

    Natural food antimicrobials are bioactive compounds that inhibit the growth of microorganisms involved in food spoilage or food-borne illness. However, stability issues result in degradation and loss of antimicrobial activity. Nanoencapsulation allows protection of antimicrobial food agents from unfavorable environmental conditions and incompatibilities. Encapsulation of food antimicrobials control delivery increasing the concentration of the antimicrobials in specific areas and the improvement of passive cellular absorption mechanisms resulted in higher antimicrobial activity. This paper reviews the present state of the art of the nanostructures used as food antimicrobial carriers including nanoemulsions, nanoliposomes, nanoparticles, and nanofibers. PMID:24995363

  2. A novel antimicrobial protein for plant protection consisting of a Xanthomonas oryzae harpin and active domains of cecropin A and melittin

    PubMed Central

    Che, Yi?Zhou; Li, Yu?Rong; Zou, Hua?Song; Zou, Li?Fang; Zhang, Bing; Chen, Gong?You

    2011-01-01

    Summary Discoveries about antimicrobial peptides and plant defence activators have made possible the de novo and rational design of novel peptides for use in crop protection. Here we report a novel chimeric protein, Hcm1, which was made by linking the active domains of cecropin A and melittin to the hypersensitive response (HR)?elicitor Hpa1 of Xanthomonas oryzae pv. oryzicola, the causal agent of rice bacterial leaf streak. The resulting chimeric protein maintained not only the HR?inducing property of the harpin, but also the antimicrobial activity of the cecropin A?melittin hybrid. Hcm1 was purified from engineered Escherichia coli and evaluated in terms of the minimal inhibitory concentration (MIC) and the 50% effective dose (ED50) against important plant pathogenic bacteria and fungi. Importantly, the protein acted as a potential pesticide by inducing disease resistance for viral, bacterial and fungal pathogens. This designed drug can be considered as a lead compound for use in plant protection, either for the development of new broad?spectrum pesticides or for expression in transgenic plants. PMID:21895994

  3. Antimicrobial action of exogenous chitosan.

    PubMed

    Cuero, R G

    1999-01-01

    The objective of this chapter is to present fundamental factors (e.g. intrinsic and extrinsic) influencing chitosan as antimicrobial agent, for effective practical application. The antimicrobial activity of chitosan is well observed on a wide variety of micro-organisms including fungi, algae and some bacteria. However, the antimicrobial action is influenced by intrinsic and extrinsic factors such as the type of chitosan (e.g. plain or derivative); degree of chitosan polymerization; host natural nutrient constituency; substrate chemical and/or nutrient composition; and environmental conditions (e.g. substrate water activity (Aw) and/or moisture). Although both plain and derivative chitosans are effective as antimicrobial agents, there is a differential effect between them. Their differential antimicrobial effect is mainly exhibited in live host plants; thus the antifungal effect of N-carboxymethyl chitosan (NCMC) is different in vegetable as compared with graminea host. At the same time, pentamer and heptamer chitosan units seem to have better antifungal action than larger units. Chitosan antimicrobial action is more immediate on fungi and algae, followed by bacteria; the chitosan site of action is at the microbial cell wall. PMID:10906970

  4. Studies of the in vitro anticancer, antimicrobial and antioxidant potentials of selected Yemeni medicinal plants from the island Soqotra

    Microsoft Academic Search

    Ramzi A Mothana; Ulrike Lindequist; Renate Gruenert; Patrick J Bednarski

    2009-01-01

    BACKGROUND: Recent years have witnessed that there is a revival of interest in drug discovery from medicinal plants for the maintenance of health in all parts of the world. The aim of this work was to investigate 26 plants belonging to 17 families collected from a unique place in Yemen (Soqotra Island) for their in vitro anticancer, antimicrobial and antioxidant

  5. Antimicrobial effects of Finnish plant extracts containing flavonoids and other phenolic compounds.

    PubMed

    Rauha, J P; Remes, S; Heinonen, M; Hopia, A; Kähkönen, M; Kujala, T; Pihlaja, K; Vuorela, H; Vuorela, P

    2000-05-25

    Plant phenolics, especially dietary flavonoids, are currently of growing interest owing to their supposed functional properties in promoting human health. Antimicrobial screening of 13 phenolic substances and 29 extracts prepared from Finnish plant materials against selected microbes was conducted in this study. The tests were carried out using diffusion methods with four to nine microbial species (Aspergillus niger, Bacillus subtilis, Candida albicans, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Saccharomyces cerevisiae, Staphylococcus aureus and Staphylococcus epidermidis). Flavone, quercetin and naringenin were effective in inhibiting the growth of the organisms. The most active plant extracts were purple loosestrife (Lythrum salicaria L.) against Candida albicans, meadowsweet (Filipendula ulmaria (L.) Maxim.), willow herb (Epilobium angustifolium L.), cloudberry (Rubus chamaemorus L.) and raspberry (Rubus idaeus L.) against bacteria, and white birch (Betula pubescens Ehrh.), pine (Pinus sylvestris L.) and potato (Solanum tuberosum. L.) against gram-positive Staphylococcus aureus. PMID:10857921

  6. Preliminary Screening of Endophytic Fungi from Medicinal Plants in Malaysia for Antimicrobial and Antitumor Activity

    PubMed Central

    Radu, Son; Kqueen, Cheah Yoke

    2002-01-01

    The screening of antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, yeast and fungi was carried out on isopropanol extracts prepared from 121 isolates of endophytic fungi isolated from medicinal plants in Malaysia. Sensitivity was found to vary among the microorganisms. Bacillus subtilis, Saccharomyces cerevisiae and Alternaria sp. were susceptible to extracts from three, two and two isolates of endophytic fungi, respectively. None were found effective against Salmonella typhimurium. Sixteen endophytic fungal isolates tested were also found to exhibit antitumor activity in the yeast cell-based assay. PMID:22844221

  7. Metabolomics reveals the origins of antimicrobial plant resins collected by honey bees.

    PubMed

    Wilson, Michael B; Spivak, Marla; Hegeman, Adrian D; Rendahl, Aaron; Cohen, Jerry D

    2013-01-01

    The deposition of antimicrobial plant resins in honey bee, Apis mellifera, nests has important physiological benefits. Resin foraging is difficult to approach experimentally because resin composition is highly variable among and between plant families, the environmental and plant-genotypic effects on resins are unknown, and resin foragers are relatively rare and often forage in unobservable tree canopies. Subsequently, little is known about the botanical origins of resins in many regions or the benefits of specific resins to bees. We used metabolomic methods as a type of environmental forensics to track individual resin forager behavior through comparisons of global resin metabolite patterns. The resin from the corbiculae of a single bee was sufficient to identify that resin's botanical source without prior knowledge of resin composition. Bees from our apiary discriminately foraged for resin from eastern cottonwood (Populus deltoides), and balsam poplar (P. balsamifera) among many available, even closely related, resinous plants. Cottonwood and balsam poplar resin composition did not show significant seasonal or regional changes in composition. Metabolomic analysis of resin from 6 North American Populus spp. and 5 hybrids revealed peaks characteristic to taxonomic nodes within Populus, while antimicrobial analysis revealed that resin from different species varied in inhibition of the bee bacterial pathogen, Paenibacillus larvae. We conclude that honey bees make discrete choices among many resinous plant species, even among closely related species. Bees also maintained fidelity to a single source during a foraging trip. Furthermore, the differential inhibition of P. larvae by Populus spp., thought to be preferential for resin collection in temperate regions, suggests that resins from closely related plant species many have different benefits to bees. PMID:24204850

  8. Metabolomics Reveals the Origins of Antimicrobial Plant Resins Collected by Honey Bees

    PubMed Central

    Wilson, Michael B.; Spivak, Marla; Hegeman, Adrian D.; Rendahl, Aaron; Cohen, Jerry D.

    2013-01-01

    The deposition of antimicrobial plant resins in honey bee, Apis mellifera, nests has important physiological benefits. Resin foraging is difficult to approach experimentally because resin composition is highly variable among and between plant families, the environmental and plant-genotypic effects on resins are unknown, and resin foragers are relatively rare and often forage in unobservable tree canopies. Subsequently, little is known about the botanical origins of resins in many regions or the benefits of specific resins to bees. We used metabolomic methods as a type of environmental forensics to track individual resin forager behavior through comparisons of global resin metabolite patterns. The resin from the corbiculae of a single bee was sufficient to identify that resin's botanical source without prior knowledge of resin composition. Bees from our apiary discriminately foraged for resin from eastern cottonwood (Populus deltoides), and balsam poplar (P. balsamifera) among many available, even closely related, resinous plants. Cottonwood and balsam poplar resin composition did not show significant seasonal or regional changes in composition. Metabolomic analysis of resin from 6 North American Populus spp. and 5 hybrids revealed peaks characteristic to taxonomic nodes within Populus, while antimicrobial analysis revealed that resin from different species varied in inhibition of the bee bacterial pathogen, Paenibacillus larvae. We conclude that honey bees make discrete choices among many resinous plant species, even among closely related species. Bees also maintained fidelity to a single source during a foraging trip. Furthermore, the differential inhibition of P. larvae by Populus spp., thought to be preferential for resin collection in temperate regions, suggests that resins from closely related plant species many have different benefits to bees. PMID:24204850

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Commensal Escherichia coli isolate resistant to eight classes of antimicrobial agents in the United States.

    PubMed

    Krueger, Amy L; Folster, Jason; Medalla, Felicita; Joyce, Kevin; Perri, Mary Beth; Johnson, Laura; Zervos, Marcus; Whichard, Jean M; Barzilay, Ezra J

    2011-02-01

    To increase understanding of community-acquired resistance, stool samples from 477 nonhospitalized persons in Maryland and Michigan, from 2004 to 2008, were screened for ceftriaxone resistance. Seven (1.5%) yielded ceftriaxone-resistant Escherichia coli; one isolate was resistant to all eight antimicrobial classes routinely tested: aminoglycosides, ?-lactam/?-lactamase inhibitor combinations, cephems, penicillins, folate pathway inhibitors, phenicols, quinolones, and tetracyclines. The extensively resistant isolate was from a 50-year-old woman who denied antimicrobial use, hospitalization, or international travel within 6 months. Meat (beef, chicken, and pork) and eggs were consumed within 1 month before stool collection. Further studies are warranted to understand potential sources, including the food supply, of resistant E. coli. PMID:20973731

  11. Synthesis and Evaluation of Some Novel Chromone Based Dithiazoles as Antimicrobial Agents

    PubMed Central

    Aggarwal, Naureen; Sharma, Vishal; Kaur, Harpreet; Ishar, Mohan Paul Singh

    2013-01-01

    Novel substituted 1,2,4-dithiazolylchromones 3a–j were synthesized by the reaction of 3-formylchromones (1a–j) with two equivalents of p-chlorothiobenzamide (2) in dry xylene and characterized spectroscopically (IR, 1H and 13C NMR, mass) and elemental analysis. All synthesized compounds were screened for in vitro antimicrobial activity against various pathogenic bacterial and fungal strains and were found to possess good to moderate inhibitory potential against all tested strains. Antimicrobial results reveal that compounds bearing lipophilic electron withdrawing groups such as chloro and bromo displayed significant inhibitory potential against both bacterial and fungal strains. Particularly, compound 3c displayed significant inhibitory against bacterial strains and compound 3h exhibits significant inhibitory potential in comparison to standard drug fluconazole against fungal strain S. cerevisiae. PMID:25379291

  12. Optimization and production of novel antimicrobial agents from sponge associated marine actinomycetes Nocardiopsis dassonvillei MAD08

    Microsoft Academic Search

    Joseph Selvin; S. Shanmughapriya; R. Gandhimathi; G. Seghal Kiran; T. Rajeetha Ravji; K. Natarajaseenivasan; T. A. Hema

    2009-01-01

    The sponge-associated actinomycetes were isolated from the marine sponge Dendrilla nigra, collected from the southwest coast of India. Eleven actinomycetes were isolated depending upon the heterogeneity and stability\\u000a in subculturing. Among these, Nocardiopsis dassonvillei MAD08 showed 100% activity against the multidrug resistant pathogens tested. The culture conditions of N. dassonvillei MAD08 was optimized under submerged fermentation conditions for enhanced antimicrobial

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

    PubMed

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

    2010-11-01

    Ten silver(I) cyanoximates of AgL composition (L = NC-C(NO)-R, where R is electron withdrawing groups: -CN, -C(O)NR(2), -C(O)R' (alkyl), -C(O)OEt, 2-heteroaryl fragments such as 2-pyridyl, 2-benzimidazolyl, 2-benzoxazolyl, 2-benzthiazolyl) were synthesized and characterized using spectroscopic methods and X-ray analysis. Crystal structures of four complexes were determined and revealed the formation of two-dimensional (2D) coordination polymers of different complexity in which anions exhibit bridging or combined chelate and bridging binding modes. In these compounds, anions are in the nitroso form. All studied AgL complexes are sparingly soluble in water and are thermally stable to 150 °C. Synthesized compounds demonstrated remarkable insensitivity toward visible light and UV-radiation, which was explained based on their polymeric structures with multiple covalent bonds between bridging cyanoxime ligands and Ag(I) centers. All 10 silver(I) cyanoximates were tested in vitro on the subject of their antimicrobial activity against both Gram-positive and Gram-negative microorganisms such as Escherichia coli, Klebsiella pneumoniae, Proteus sp., Pseudomonas aeruginosa, Enterococcus hirae, Streptococcus mutans, Staphylococcus aureus, and Mycobacterium fortuitum as well as against Candida albicans in solutions, and in the solid state as pressed pellets and dried filter paper disks presoaked with solutions of AgL in DMF. Results showed pronounced antimicrobial activity for all investigated complexes. A combination of five factors: (1) light insensitivity, (2) poor water solubility, (3) high thermal stability, (4) lack of toxicity of organic ligands, and (5) in vitro antimicrobial activity allows development of silver(I) cyanoximates for medical applications. These include antimicrobial additives to acrylate glue, cured by UV-radiation, used in introduction of prosthetic joints and dental implants, and prevention of biofilm formation on several types of indwelling medical devices. PMID:20873734

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

    PubMed

    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 (p<0.05). At 168 h, all materials showed similar pHs (p>0.05). 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. PMID:23306227

  15. Use of mandelic acid condensation polymer (SAMMA), a new antimicrobial contraceptive agent, for vaginal prophylaxis

    Microsoft Academic Search

    Lourens J. D Zaneveld; Robert A Anderson; Xiao-Hui Diao; Donald P Waller; Calvin Chany; Kenneth Feathergill; Gustavo Doncel; Morris D Cooper; Betsy Herold

    2002-01-01

    Objective: To assess the contraceptive properties, antimicrobial activity, and safety of mandelic acid condensation polymer (SAMMA).Design: Experimental study of SAMMA’s in vitro and in vivo properties.Setting: Academic research laboratories.Patient(s): Healthy volunteers for semen donation in an academic research environment.Intervention(s): Inhibition of sperm function indicators, conception, sexually transmitted infection-causing pathogens (including HIV), and lactobacilli was evaluated. Safety indicators were studied.Main Outcome

  16. [Antimicrobial activities of ant Ponericin W1 against plant pathogens in vitro and the disease resistance in its transgenic Arabidopsis].

    PubMed

    Chen, Yong-Fang; Sun, Peng-Wei; Tang, Ding-Zhong

    2013-08-01

    The antimicrobial peptides (AMPs) exhibit a broad antimicrobial spectrum. The application of AMPs from non-plant organisms attracts considerable attention in plant disease resistance engineering. Ponericin W1, isolated from the venom of ant (Pachycondyla goeldii), shows antimicrobial activities against Gram-positive bacteria, Gram-negative bacteria and the budding yeast (Saccharomyces cerevisiae); however, it is not clear whether Ponericin W1 is effective against plant pathogens. The results of this study indicated synthesized Ponericin W1 inhibited mycelial growth of Magnaporthe oryzae and Botrytis cinerea, as well as hyphal growth and spore production of Fusarium graminearum. Besides, Ponericin W1 exhibited antibacterial activities against Pseudomonas syringae pv. tomato and Xanthomonas oryzae pv. oryzae. After codon optimization, Ponericin W1 gene was constructed into plant expression vector, and transformed into Arabidopsis thaliana by floral dip method. The Ponericin W1 was located in intercellular space of the transgenic plants as expected. Compared with the wild-type plants, there were ungerminated spores and less hyphal, conidia on the leaves of transgenic plants after innoculation with the powdery mildew fungus Golovinomyces cichoracearum. After innoculation with the pathogenic bac-terium Pseudomonas syringae pv. tomato, the baceria in the leaves of transgenic plants was significantly less than the wild-type plants, indicating that the transgenic plants displayed enhanced disease resistance to pathogens. These results demonstrate a potential use of Ponericin W1 in genetic engineering for broad-spectrum plant disease resistance. PMID:23956091

  17. Discovery of new anticancer agents from higher plants

    PubMed Central

    Pan, Li; Chai, Hee-Byung; Kinghorn, A. Douglas

    2012-01-01

    1. ABSTRACT Small organic molecules derived from higher plants have been one of the mainstays of cancer chemotherapy for approximately the past half a century. In the present review, selected single chemical entity natural products of plant origin and their semi-synthetic derivatives currently in clinical trials are featured as examples of new cancer chemotherapeutic drug candidates. Several more recently isolated compounds obtained from plants showing promising in vivo biological activity are also discussed in terms of their potential as anticancer agents, with many of these obtained from species that grow in tropical regions. Since extracts of only a relatively small proportion of the ca. 300,000 higher plants on earth have been screened biologically to date, bioactive compounds from plants should play an important role in future anticancer drug discovery efforts. PMID:22202049

  18. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, July 2009, p. 28242833 Vol. 53, No. 7 0066-4804/09/$08.00 0 doi:10.1128/AAC.01568-08

    E-print Network

    Schnaufer, Achim

    and Drug Discovery, School of Life Sciences, Wellcome Trust Biocentre, University of Dundee, DundeeANTIMICROBIAL AGENTS AND CHEMOTHERAPY, July 2009, p. 2824­2833 Vol. 53, No. 7 0066-4804/09/$08.00 0 Royal Pde,1 and Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences

  19. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, July 2010, p. 28932900 Vol. 54, No. 7 0066-4804/10/$12.00 doi:10.1128/AAC.00332-10

    E-print Network

    Schnaufer, Achim

    * Division of Biological Chemistry and Drug Discovery, Wellcome Trust Biocentre, College of Life SciencesANTIMICROBIAL AGENTS AND CHEMOTHERAPY, July 2010, p. 2893­2900 Vol. 54, No. 7 0066. Cross-Resistance to Nitro Drugs and Implications for Treatment of Human African Trypanosomiasis

  20. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Apr. 2008, p. 13591365 Vol. 52, No. 4 0066-4804/08/$08.00 0 doi:10.1128/AAC.01563-07

    E-print Network

    Schnaufer, Achim

    Wyllie,* Tim J. Vickers, and Alan H. Fairlamb Division of Biological Chemistry and Drug DiscoveryANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Apr. 2008, p. 1359­1365 Vol. 52, No. 4 0066-4804/08/$08.00 0 The clinical value of antimonial drugs, the mainstay therapy for leishmaniasis, is now threatened

  1. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 0066-4804/01/$04.00 0 DOI: 10.1128/AAC.45.6.19281929.2001

    E-print Network

    ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 0066-4804/01/$04.00 0 DOI: 10.1128/AAC.45 Reserved. In Vitro Growth of Leishmania amazonensis Promastigotes Resistant to Pentamidine Is Dependent resistance. In particular, the growth of resistant strains was reduced when they shared the same environment

  2. Apple Puree-Alginate Edible Coating as Carrier of Antimicrobial Agents to Prolong Shelf-Life of Fresh-Cut Apples

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. A Mixed-culture Chemostat System to Predict the Effect of Antimicrobial Agents on the Oral Flora: Preliminary Studies using Chlorhexidine

    Microsoft Academic Search

    A. S. McDermid; A. S. McKee; P. D. Marsh

    1987-01-01

    A mixed-culture chemostat system, composed of nine bacterial species representative of plaque in health and disease, has been assessed as an improved laboratory method of evaluating the likely in vivo effects of antimicrobial agents used in dentistry. The advantages of the system include reproducibility, the long-term stable cultivation of bacteria under controllable conditions, and repeated sampling, for bacteriological and biochemical

  4. Synthesis, Biological Evaluation and 2D-QSAR Study of Halophenyl Bis-Hydrazones as Antimicrobial and Antitubercular Agents.

    PubMed

    Abdel-Aziz, Hatem A; Eldehna, Wagdy M; Fares, Mohamed; Al-Rashood, Sara T A; Al-Rashood, Khalid A; Abdel-Aziz, Marwa M; Soliman, Dalia H

    2015-01-01

    In continuation of our endeavor towards the development of potent and effective antimicrobial agents, three series of halophenyl bis-hydrazones (14a-n, 16a-d, 17a and 17b) were synthesized and evaluated for their potential antibacterial, antifungal and antimycobacterial activities. These efforts led to the identification of five molecules 14c, 14g, 16b, 17a and 17b (MIC range from 0.12 to 7.81 ?g/mL) with broad antimicrobial activity against Mycobacterium tuberculosis; Aspergillus fumigates; Gram positive bacteria, Staphylococcus aureus, Streptococcus pneumonia, and Bacillis subtilis; and Gram negative bacteria, Salmonella typhimurium, Klebsiella pneumonia, and Escherichia coli. Three of the most active compounds, 16b, 17a and 17b, were also devoid of apparent cytotoxicity to lung cancer cell line A549. Amphotericin B and ciprofloxacin were used as references for antifungal and antibacterial screening, while isoniazid and pyrazinamide were used as references for antimycobacterial activity. Furthermore, three Quantitative Structure Activity Relationship (QSAR) models were built to explore the structural requirements controlling the different activities of the prepared bis-hydrazones. PMID:25903147

  5. In Vitro Antimicrobial Activity of Extracts from Plants Used Traditionally in South Africa to Treat Tuberculosis and Related Symptoms

    PubMed Central

    Madikizela, Balungile; Ndhlala, Ashwell Rungano; Finnie, Jeffrey Franklin; Staden, Johannes Van

    2013-01-01

    Respiratory ailments are major human killers, especially in developing countries. Tuberculosis (TB) is an infectious disease causing a threat to human healthcare. Many South African plants are used in the traditional treatment of TB and related symptoms, but there has not been a sufficient focus on evaluating their antimicrobial properties. The aim of this study was to evaluate the antimicrobial properties of plants used traditionally to treat TB and related symptoms against microorganisms (Klebsiella pneumoniae, Staphylococcus aureus, and Mycobacterium aurum A+) associated with respiratory infections using the microdilution assay. Ten plants were selected based on a survey of available literature of medicinal plants used in South Africa for the treatment of TB and related symptoms. The petroleum ether, dichloromethane, 80% ethanol, and water extracts of the selected plants were evaluated for antibacterial activity. Out of 68 extracts tested from different parts of the 10 plant species, 17 showed good antimicrobial activities against at least one or more of the microbial strains tested, with minimum inhibitory concentration ranging from 0.195 to 12.5?mg/mL. The good antimicrobial properties of Abrus precatorius, Terminalia phanerophlebia, Indigofera arrecta, and Pentanisia prunelloides authenticate their traditional use in the treatment of respiratory diseases. Thus, further pharmacological and phytochemical analysis is required. PMID:23533527

  6. Biodiversity of genes encoding anti-microbial traits within plant associated microbes

    PubMed Central

    Mousa, Walaa K.; Raizada, Manish N.

    2015-01-01

    The plant is an attractive versatile home for diverse associated microbes. A subset of these microbes produces a diversity of anti-microbial natural products including polyketides, non-ribosomal peptides, terpenoids, heterocylic nitrogenous compounds, volatile compounds, bacteriocins, and lytic enzymes. In recent years, detailed molecular analysis has led to a better understanding of the underlying genetic mechanisms. New genomic and bioinformatic tools have permitted comparisons of orthologous genes between species, leading to predictions of the associated evolutionary mechanisms responsible for diversification at the genetic and corresponding biochemical levels. The purpose of this review is to describe the biodiversity of biosynthetic genes of plant-associated bacteria and fungi that encode selected examples of antimicrobial natural products. For each compound, the target pathogen and biochemical mode of action are described, in order to draw attention to the complexity of these phenomena. We review recent information of the underlying molecular diversity and draw lessons through comparative genomic analysis of the orthologous coding sequences (CDS). We conclude by discussing emerging themes and gaps, discuss the metabolic pathways in the context of the phylogeny and ecology of their microbial hosts, and discuss potential evolutionary mechanisms that led to the diversification of biosynthetic gene clusters.

  7. Antimicrobial, Antioxidant and Cytotoxic Activities and Phytochemical Screening of Some Yemeni Medicinal Plants

    PubMed Central

    Abdo, Salah A. A.; Hasson, Sidgi; Althawab, Faisal M. N.; Alaghbari, Sama A. Z.; Lindequist, Ulrike

    2010-01-01

    The traditional medicine still plays an important role in the primary health care in Yemen. The current study represents the investigation of 16 selected plants, which were collected from different localities of Yemen. The plants were dried and extracted with two different solvents (methanol and hot water) to yield 34 crude extracts. The obtained extracts were tested for their antimicrobial activity against three Gram-positive bacteria, two Gram-negative bacteria, one yeast species and three multiresistant Staphylococcus strains using agar diffusion method, for their antioxidant activity using scavenging activity of DPPH radical method and for their cytotoxic activity using the neutral red uptake assay. In addition, a phytochemical screening of the methanolic extracts was done. Antibacterial activity was shown only against Gram-positive bacteria, among them multiresistant bacteria. The highest antimicrobial activity was exhibited by the methanolic extracts of Acalypha fruticosa, Centaurea pseudosinaica, Dodonaea viscosa, Jatropha variegata, Lippia citriodora, Plectranthus hadiensis, Tragia pungens and Verbascum bottae. Six methanolic extracts especially those of A. fruticosa, Actiniopteris semiflabellata, D. viscosa, P. hadiensis, T. pungens and V. bottae showed high free radical scavenging activity. Moreover, remarkable cytotoxic activity against FL-cells was found for the methanolic extracts of A. fruticosa, Iris albicans, L. citriodora and T. pungens. The phytochemical screening demonstrated the presence of different types of compounds like flavonoids, terpenoids and others, which could be responsible for the obtained activities. PMID:18955315

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

    PubMed

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

    2013-07-01

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

  9. Production of phytotoxic cationic ?-helical antimicrobial peptides in plant cells using inducible promoters.

    PubMed

    Company, Nuri; Nadal, Anna; Ruiz, Cristina; Pla, Maria

    2014-01-01

    Synthetic linear antimicrobial peptides with cationic ?-helical structures, such as BP100, have potent and specific activities against economically important plant pathogenic bacteria. They are also recognized as valuable therapeutics and preservatives. However, highly active BP100 derivatives are often phytotoxic when expressed at high levels as recombinant peptides in plants. Here we demonstrate that production of recombinant phytotoxic peptides in transgenic plants is possible by strictly limiting transgene expression to certain tissues and conditions, and specifically that minimization of this expression during transformation and regeneration of transgenic plants is essential to obtain viable plant biofactories. On the basis of whole-genome transcriptomic data available online, we identified the Os.hsp82 promoter that fulfilled this requirement and was highly induced in response to heat shock. Using this strategy, we generated transgenic rice lines producing moderate yields of severely phytotoxic BP100 derivatives on exposure to high temperature. In addition, a threshold for gene expression in selected tissues and stages was experimentally established, below which the corresponding promoters should be suitable for driving the expression of recombinant phytotoxic proteins in genetically modified plants. In view of the growing transcriptomics data available, this approach is of interest to assist promoter selection for specific purposes. PMID:25387106

  10. Multitasking antimicrobial peptides in plant development and host defense against biotic/abiotic stress.

    PubMed

    Goyal, Ravinder K; Mattoo, Autar K

    2014-11-01

    Crop losses due to pathogens are a major threat to global food security. Plants employ a multilayer defense against a pathogen including the use of physical barriers (cell wall), induction of hypersensitive defense response (HR), resistance (R) proteins, and synthesis of antimicrobial peptides (AMPs). Unlike a complex R gene-mediated immunity, AMPs directly target diverse microbial pathogens. Many a times, R-mediated immunity breaks down and plant defense is compromised. Although R-gene dependent pathogen resistance has been well studied, comparatively little is known about the interactions of AMPs with host defense and physiology. AMPs are ubiquitous, low molecular weight peptides that display broad spectrum resistance against bacteria, fungi and viruses. In plants, AMPs are mainly classified into cyclotides, defensins, thionins, lipid transfer proteins, snakins, and hevein-like vicilin-like and knottins. Genetic distance lineages suggest their conservation with minimal effect of speciation events during evolution. AMPs provide durable resistance in plants through a combination of membrane lysis and cellular toxicity of the pathogen. Plant hormones - gibberellins, ethylene, jasmonates, and salicylic acid, are among the physiological regulators that regulate the expression of AMPs. Transgenically produced AMP-plants have become a means showing that AMPs are able to mitigate host defense responses while providing durable resistance against pathogens. PMID:25438794

  11. Production of Phytotoxic Cationic ?-Helical Antimicrobial Peptides in Plant Cells Using Inducible Promoters

    PubMed Central

    Company, Nuri; Nadal, Anna; Ruiz, Cristina; Pla, Maria

    2014-01-01

    Synthetic linear antimicrobial peptides with cationic ?-helical structures, such as BP100, have potent and specific activities against economically important plant pathogenic bacteria. They are also recognized as valuable therapeutics and preservatives. However, highly active BP100 derivatives are often phytotoxic when expressed at high levels as recombinant peptides in plants. Here we demonstrate that production of recombinant phytotoxic peptides in transgenic plants is possible by strictly limiting transgene expression to certain tissues and conditions, and specifically that minimization of this expression during transformation and regeneration of transgenic plants is essential to obtain viable plant biofactories. On the basis of whole-genome transcriptomic data available online, we identified the Os.hsp82 promoter that fulfilled this requirement and was highly induced in response to heat shock. Using this strategy, we generated transgenic rice lines producing moderate yields of severely phytotoxic BP100 derivatives on exposure to high temperature. In addition, a threshold for gene expression in selected tissues and stages was experimentally established, below which the corresponding promoters should be suitable for driving the expression of recombinant phytotoxic proteins in genetically modified plants. In view of the growing transcriptomics data available, this approach is of interest to assist promoter selection for specific purposes. PMID:25387106

  12. Antimicrobial activity of some water plants from the northeastern Anatolian region of Turkey.

    PubMed

    Ozbay, Hanife; Alim, Ahmet

    2009-01-01

    The antimicrobial activity of methanol and acetone extracts of Butomus umbellatus, Polygonum amphibium, and two species of the genus Sparganium (S. erectum and S. emersum)against three Gram-positive, five Gram-negative bacteria and one fungus was assessed by the disk diffusion method. The microorganisms used were Staphylococcus aureusATCC-29740, Escherichia coli ATCC-25922, Pseudomonas aeruginosa ATCC-15442, Salmonella typhi NCTC-9394, Klebsiella pneumoniae NCTC-5046, Proteus vulgaris ATCC-7829, Bacillus subtilis ATCC-6633, Corynebacterium diphteriae RSHM-633 and Candida albicans ATCC-10231. Methanol extracts of the plants did not exhibit any inhibitory activity against any of the microorganisms, while the acetone extracts of the all tested plants only showed significant activity against Bacillus subtilis, with inhibition zones and minimal inhibitory concentration values in the 7-16 mm and 0.49-12.50 mg/mL ranges, respectively. PMID:19145212

  13. ANTIMICROBIAL ACTIVITY AND PHYTOCHEMICAL SCREENING OF CRUDE EXTRACTS OF MEDICINAL PLANTS GROWN IN EASTERN ETHIOPIA

    E-print Network

    Kesatebrhan Haile Asressu

    The aim of my research was to screen secondary metabolites and antimicrobial activities of methanolic extracts of the leaves Vernonia amygdalina and Plantago lanceolata, and acetone extracts of the leaves Rosmarinus officinalis and Thymus schimperi against two bacteria (Staphylococcus aureus and Escherichia coli) and two fungi (Aspergillus niger and Fusarium oxysporum) using paper disc diffusion method. Phytochemical screening of the extracts revealed the presence of alkaloids, flavonoids, saponins, steroids, tannins, phenolic compounds, anthraquinones, cardiac glycosides and triterpenes in the plants investigated. The plant extracts were found to be more effective on bacteria than fungi. The bioassay has indicated that the inhibition effect of the extracts was proportional to the concentration. The acetone leaf extracts of Rosmarinus officinalis possess higher antibacterial properties than Vernonia amygdalina, Plantago lanceolata and Thymus schimperi. Phytochemical investigation results showed that the highest antibacterial potential of Rosmarinus officinalis may be attributed to flavonoids, phenolic compounds and triterpenes.

  14. Cyclodextrins as encapsulation agents for plant bioactive compounds.

    PubMed

    Pinho, Eva; Grootveld, Martin; Soares, Graça; Henriques, Mariana

    2014-01-30

    Plants possess a wide range of molecules capable of improve healing: fibre, vitamins, phytosterols, and further sulphur-containing compounds, carotenoids, organic acid anions and polyphenolics. However, they require an adequate level of protection from the environmental conditions to prevent losing their structural integrity and bioactivity. Cyclodextrins are cyclic oligosaccharides arising from the degradation of starch, which can be a viable option as encapsulation technique. Cyclodextrins are inexpensive, friendly to humans, and also capable of improving the biological, chemical and physical properties of bioactive molecules. Therefore, the aim of this review is to highlight the use of cyclodextrins as encapsulating agents for bioactive plant molecules in the pharmaceutical field. PMID:24299757

  15. A Study on the Usage Pattern of Antimicrobial Agents for the Prevention of Surgical Site Infections (SSIs) in a Tertiary Care Teaching Hospital

    PubMed Central

    Khan A.K, Afzal; P.V, Mirshad; Rashed, Mohammed Rafiuddin; Banu, Gausia

    2013-01-01

    Context: Inappropriate antimicrobial use increases the incidence of drug resistance, drug toxicity and superinfections, thereby increasing the healthcare costs. Various approaches for rationalizing the antimicrobial therapy, have been suggested. Collection of baseline data on the pattern of the antimicrobial use is usually suggested as the first step in this direction, which will help in identifying the problem areas, which demand our attention. Aims: To study the usage pattern of prophylactic antimicrobials in surgical patients, in order to detect any inappropriateness concerning the selection, timing, redosing and the duration of antimicrobial administration. Settings and Design: A retrospective review of the randomly selected medical records of general surgical cases over an 8 month period in a tertiary care teaching hospital. Methods and Material: The medical records of 258 patients who had undergone surgical procedures were verified for the appropriateness of the antimicrobial prophylaxis, with respect to the choice of the antimicrobial agent, the time of its administration, the intraoperative dosing, and the duration of the postoperative use. The obtained data was analyzed and conclusions were drawn with the help of descriptive statistics. Results: Third generation cephalosporins were used preoperatively in all the 258(100%) patients through the intravenous route. In addition, 77(30%) patients received metronidazole or amikacin. The antimicrobials were administered half an hour to one hour before the surgery. No intraoperative redosing was given. The duration of the postoperative prophylaxis was extended to 36 hours or more in 248(96%) of the cases. Conclusions: The timing of administration of the preoperative dose was appropriate and well delegated to the operating room nurse. The intra operative dose was appropriately omitted. The main concern was the increasing use of the third generation cephalosporins and the unnecessary prolonged duration of the postoperative prophylaxis, which needed to be addressed. PMID:23730643

  16. Screening for antimicrobial activity of ten medicinal plants used in Colombian folkloric medicine: A possible alternative in the treatment of non-nosocomial infections

    PubMed Central

    Rojas, Jhon J; Ochoa, Veronica J; Ocampo, Saul A; Muñoz, John F

    2006-01-01

    Background The antimicrobial activity and Minimal Inhibitory Concentration (MIC) of the extracts of Bidens pilosa L., Bixa orellana L., Cecropia peltata L., Cinchona officinalis L., Gliricidia sepium H.B. & K, Jacaranda mimosifolia D.Don, Justicia secunda Vahl., Piper pulchrum C.DC, P. paniculata L. and Spilanthes americana Hieron were evaluated against five bacteria (Staphylococcus aureus, Streptococcus ? hemolític, Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli), and one yeast (Candida albicans). These plants are used in Colombian folk medicine to treat infections of microbial origin. Methods Plants were collected by farmers and traditional healers. The ethanol, hexane and water extracts were obtained by standard methods. The antimicrobial activity was found by using a modified agar well diffusion method. All microorganisms were obtained from the American Type Culture Collection (ATCC). MIC was determined in the plant extracts that showed some efficacy against the tested microorganisms. Gentamycin sulfate (1.0 ?g/ml), clindamycin (0.3 ?g/ml) and nystatin (1.0 ?g/ml) were used as positive controls. Results The water extracts of Bidens pilosa L., Jacaranda mimosifolia D.Don, and Piper pulchrum C.DC showed a higher activity against Bacillus cereus and Escherichia coli than gentamycin sulfate. Similarly, the ethanol extracts of all species were active against Staphylococcus aureus except for Justicia secunda. Furthermore, Bixa orellana L, Justicia secunda Vahl. and Piper pulchrum C.DC presented the lowest MICs against Escherichia coli (0.8, 0.6 and 0.6 ?g/ml, respectively) compared to gentamycin sulfate (0.9 8g/ml). Likewise, Justicia secunda and Piper pulchrum C.DC showed an analogous MIC against Candida albicans (0.5 and 0.6 ?g/ml, respectively) compared to nystatin (0.6 ?g/ml). Bixa orellana L, exhibited a better MIC against Bacillus cereus (0.2 ?g/ml) than gentamycin sulfate (0.5 ?g/ml). Conclusion This in vitro study corroborated the antimicrobial activity of the selected plants used in folkloric medicine. All these plants were effective against three or more of the pathogenic microorganisms. However, they were ineffective against Streptococcus ? hemolytic and Pseudomonas aeruginosa. Their medicinal use in infections associated with these two species is not recommended. This study also showed that Bixa orellana L, Justicia secunda Vahl. and Piper pulchrum C.DC could be potential sources of new antimicrobial agents. PMID:16483385

  17. Corpet et al., 1989 Antimicrob. Agents Chemother. 33 : 535-540 Author's Version 535 Antimicrobial Agents and Chemotherapy, Apr. 1989. Vol. 33, No. 4, p. 535-540 Author's Version

    E-print Network

    Paris-Sud XI, Université de

    Levels for Selecting a Resistance Plasmid in a Gnotobiotic Animal Model DENIS E. CORPET,* SOLANGE LUMEAU Antimicrobial Agents and Chemotherapy, Apr. 1989. Vol. 33, No. 4, p. 535-540 Author's Version Minimum Antibiotic,31931 Toulouse, France The minimum antibiotic concentrations for selecting an R plasmid in vivo were determined

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

    PubMed

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

    2010-10-01

    Essential oils of clove (Syzygium aromaticum L.), fennel (Foeniculum vulgare Miller), cypress (Cupressus sempervirens L.), lavender (Lavandula angustifolia), thyme (Thymus vulgaris L.), herb-of-the-cross (Verbena officinalis L.), pine (Pinus sylvestris) and rosemary (Rosmarinus officinalis) were tested for their antimicrobial activity on 18 genera of bacteria, which included some important food pathogen and spoilage bacteria. Clove essential oil showed the highest inhibitory effect, followed by rosemary and lavender. In an attempt to evaluate the usefulness of these essential oils as food preservatives, they were also tested on an extract made of fish, where clove and thyme essential oils were the most effective. Then, gelatin-chitosan-based edible films incorporated with clove essential oil were elaborated and their antimicrobial activity tested against six selected microorganisms: Pseudomonas fluorescens, Shewanella putrefaciens, Photobacterium phosphoreum, Listeria innocua, Escherichia coli and Lactobacillus acidophilus. The clove-containing films inhibited all these microorganisms irrespectively of the film matrix or type of microorganism. In a further experiment, when the complex gelatin-chitosan film incorporating clove essential oil was applied to fish during chilled storage, the growth of microorganisms was drastically reduced in gram-negative bacteria, especially enterobacteria, while lactic acid bacteria remained practically constant for much of the storage period. The effect on the microorganisms during this period was in accordance with biochemical indexes of quality, indicating the viability of these films for fish preservation. PMID:20688230

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

    PubMed

    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 ?g/ml), 7/77 isolates tested were resistant to ampicillin (resistance breakpoint ? 2 ?g/ml), 4/242 isolates tested were resistant to chloramphenicol (resistance breakpoint ? 32 ?g/ml), 12/158 isolates tested were resistant to clindamycin (resistance breakpoint ? 8 ?g/ml), 10/247 isolates tested were resistant to metronidazole (resistance breakpoint ? 32 ?g/ml), and 54/243 isolates tested were resistant to penicillin (resistance breakpoint ? 2 ?g/ml). These data suggest that anaerobes are generally susceptible to antimicrobial drugs in vitro. PMID:24025899

  20. C31G, a new agent for oral use with potent antimicrobial and antiadherence properties.

    PubMed

    Corner, A M; Dolan, M M; Yankell, S L; Malamud, D

    1988-03-01

    C31G, an equimolar mixture of alkyl dimethyl glycine and alkyl dimethyl amine oxide, was evaluated for antimicrobial and antiadherence properties. The efficacy of C31G, its two components, and several commercial mouth rinses was determined in assays measuring inhibition of glycolysis, inhibition of bacterial adherence, and MICs. Inhibition of glycolysis was determined by using a saliva sediment model, with glycolytic activity expressed as the change in pH relative to that of a control. Adherence studies were undertaken with Streptococcus sobrinus 6715 to measure inhibition of adherence to nichrome wires. MICs were determined against selected microorganisms by standard methods. C31G demonstrated broad-spectrum antimicrobial properties, with activity against both gram-positive and gram-negative organisms and Candida albicans, a yeast. C31G inhibited both glycolysis by salivary bacteria and adherence of Streptococcus strains to wire mesh. C31G was more effective in the assays conducted than any commercial formulation tested and was as effective as chlorhexidine. A synergistic effect was demonstrated between the individual components of C31G, and no loss of activity was noted when it was formulated into a mouth rinse vehicle. PMID:3364952

  1. Frequency of Resistance in Obligate Anaerobic Bacteria Isolated from Dogs, Cats, and Horses to Antimicrobial Agents

    PubMed Central

    Taylor, A.; Fajt, V. R.

    2013-01-01

    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 ?g/ml), 7/77 isolates tested were resistant to ampicillin (resistance breakpoint ? 2 ?g/ml), 4/242 isolates tested were resistant to chloramphenicol (resistance breakpoint ? 32 ?g/ml), 12/158 isolates tested were resistant to clindamycin (resistance breakpoint ? 8 ?g/ml), 10/247 isolates tested were resistant to metronidazole (resistance breakpoint ? 32 ?g/ml), and 54/243 isolates tested were resistant to penicillin (resistance breakpoint ? 2 ?g/ml). These data suggest that anaerobes are generally susceptible to antimicrobial drugs in vitro. PMID:24025899

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Antimicrobial Stewardship Programs

    PubMed Central

    Leuthner, Kimberly D.

    2013-01-01

    The development of antimicrobial agents represents one of the most significant achievements in medicine during the past century. However, the emergence of antimicrobial resistance combined with the downturn in the development of new antimicrobial agents in the pharmaceutical industry poses unanticipated challenges in the effective management of infection. The issue of how we can most effectively utilize these invaluable resources, antimicrobials, in the face of infections that are ever more difficult to treat arises. This issue serves as the fundamental basis for the concept of antimicrobial stewardship, the topic of this minireview. PMID:23926165

  4. Antimicrobial and inhibitory enzyme activity of N-(benzyl) and quaternary N-(benzyl) chitosan derivatives on plant pathogens.

    PubMed

    Badawy, Mohamed E I; Rabea, Entsar I; Taktak, Nehad E M

    2014-10-13

    Chemical modification of a biopolymer chitosan by introducing quaternary ammonium moieties into the polymer backbone enhances its antimicrobial activity. In the present study, a series of quaternary N-(benzyl) chitosan derivatives were synthesized and characterized by (1)H-NMR, FT-IR and UV spectroscopic techniques. The antimicrobial activity against crop-threatening bacteria Agrobacterium tumefaciens and Erwinia carotovora and fungi Botrytis cinerea, Botryodiplodia theobromae, Fusarium oxysporum and Phytophthora infestans were evaluated. The results proved that the grafting of benzyl moiety or quaternization of the derivatives onto chitosan molecule was successful in inhibiting the microbial growth. Moreover, increase water-solubility of the compounds by quaternization significantly increased the activity against bacteria and fungi. Exocellular enzymes including polygalacturonase (PGase), pectin-lyase (PLase), polyphenol oxidase (PPOase) and cellulase were also affected at 1000 mg/L. These compounds especially quaternary-based chitosan derivatives that have good inhibitory effect should be potentially used as antimicrobial agents in crop protection. PMID:25037402

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

    PubMed Central

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

    2014-01-01

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

  6. Antimicrobial activity of diterpenoids from hairy roots of Salvia sclarea L.: salvipisone as a potential anti-biofilm agent active against antibiotic resistant Staphylococci.

    PubMed

    Ku?ma, ?; Rózalski, M; Walencka, E; Rózalska, B; Wysoki?ska, H

    2007-01-01

    The antimicrobial activities of crude dichloromethane fractions from acetone extracts of Agrobacterium rhizogenes transformed roots and roots of field-grown plants of Salvia sclarea as well as four pure abietane diterpenoids isolated from the hairy root cultures were determined. The growth of Gram-positive bacteria (Staphylococcus aureus, S. epidermidis, Enterococcus faecalis) but not Gram-negative ones (Escherichia coli, Pseudomonas aeruginosa) or pathogenic fungi (Candida albicans) was inhibited by fractions tested at concentrations of 37.5-75.0 microgml(-1). Abietane diterpenoids: salvipisone, aethiopinone, 1-oxoaethiopinone and ferruginol were shown to be bacteriostatic as well as bacteriocidal for the cultures of S. aureus and S. epidermidis strains, regardless of their antibiotic susceptibility profile. This was demonstrated by using simultaneously the optical density measuring method and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide-reduction assay. The highest activity was shown by salvipisone which demonstrated also a very interesting activity when its effect on 24-h-old staphylococcal biofilm cells viability was examined. It limited the survival of biofilms formed by S. aureus as well as by S. epidermidis, putting this compound to the list of potential anti-biofilm agents, better than most of known antibiotics. PMID:17190643

  7. Anticancer and Antimicrobial Activities of Some Antioxidant-Rich Cameroonian Medicinal Plants

    PubMed Central

    Tamokou, Jean de Dieu; Chouna, Jean Rodolphe; Fischer-Fodor, Eva; Chereches, Gabriela; Barbos, Otilia; Damian, Grigore; Benedec, Daniela; Duma, Mihaela; Efouet, Alango Pépin Nkeng; Wabo, Hippolyte Kamdem; Kuiate, Jules Roger; Mot, Augustin; Silaghi-Dumitrescu, Radu

    2013-01-01

    Traditional remedies have a long-standing history in Cameroon and continue to provide useful and applicable tools for treating ailments. Here, the anticancer, antimicrobial and antioxidant activities of ten antioxidant-rich Cameroonian medicinal plants and of some of their isolated compounds are evaluated.The plant extracts were prepared by maceration in organic solvents. Fractionation of plant extract was performed by column chromatography and the structures of isolated compounds (emodin, 3-geranyloxyemodin, 2-geranylemodin) were confirmed spectroscopically. The antioxidant activity (AOA) was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) bleaching method, the trolox equivalent antioxidant capacity (TEAC), and the hemoglobin ascorbate peroxidase activity inhibition (HAPX) assays. The anticancer activity was evaluated against A431 squamous epidermal carcinoma, WM35 melanoma, A2780 ovary carcinoma and cisplatin-resistant A2780cis cells, using a direct colorimetric assay. The total phenolic content in the extracts was determined spectrophotometrically by the Folin–Ciocalteu method. Rumex abyssinicus showed the best AOA among the three assays employed. The AOA of emodin was significantly higher than that of 3-geranyloxyemodin and 2-geranylemodin for both TEAC and HAPX methods. The lowest IC50 values (i.e., highest cytotoxicity) were found for the extracts of Vismia laurentii, Psorospermum febrifugum, Pentadesma butyracea and Ficus asperifolia. The Ficus asperifolia and Psorospermum febrifugum extracts are selective against A2780cis ovary cells, a cell line which is resistant to the standard anticancer drug cisplatin. Emodin is more toxic compared to the whole extract, 3-geranyloxyemodin and 2-geranylemodin. Its selectivity against the platinum-resistant A2780cis cell line is highest. All of the extracts display antimicrobial activity, in some cases comparable to that of gentamycin. PMID:23409075

  8. In vitro activity of ceftobiprole and seven other antimicrobial agents against invasive Streptococcus pneumoniae isolates in Spain.

    PubMed

    Ríos Dueñas, E; Rodríguez-Avial, I; Picazo, J J

    2011-12-01

    The in vitro activity of ceftobiprole was compared with that of seven antimicrobial agents against invasive Streptococcus pneumoniae isolated from adult patients (>15 years old). Characterization of erythromycin-resistant strains and serotype distribution of all pneumococci were also evaluated. Seventy invasive S. pneumoniae strains were isolated from December 2007 to January 2009. Serotyping was carried out by Quellung reaction. Antibiotic susceptibility was tested by broth microdilution (CLSI guidelines). The comparator agents were penicillin, cefotaxime, erythromycin, clindamycin, telithromycin, tetracycline and moxifloxacin. Phenotypic characterization of macrolide resistance was performed by the double disk method. Macrolide resistance genes [erm(B) and mef(A/E)] and the promoter of erm(B) were detected by PCR. Twenty-five different serotypes were detected of which 87% were non-PCV7 types. The percentages of resistance to erythromycin, clindamycin and tetracycline were 20%, 8.6% and 16%, respectively. A penicillin MIC ?0.12 mg/L was observed in 14 of the 70 invasive pneumococci strains. The cefotaxime and ceftobiprole MIC(50)/MIC(90) of these 14 strains were 1/4 and 0.03/1 mg/L, respectively. Ceftobiprole showed higher in vitro activity than penicillin and cefotaxime with all isolates being inhibited by ?1 mg/L. Its high in vitro activity should make ceftobiprole a very promising drug for the treatment of pneumococcal infections. PMID:21786208

  9. DETOXIFICATION OF CORN ANTIMICROBIAL COMPOUNDS BY THE ENDOPHYTIC FUNGUS FUSARIUM VERTICILLIOIDES AND THE SIGNIFICANCE TO PLANT-FUNGUS INTERACTIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium verticillioides (= F. moniliforme) is a fungus of significant economic importance because of its deleterious effects on plant and animal health and the quality of their products. Corn, the primary host for F. verticillioides, produces the preformed antimicrobial compounds DIMBOA (2,4-dihyd...

  10. The diversity and antimicrobial activity of endophytic fungi associated with medicinal plant Baccharis trimera (Asteraceae) from the Brazilian savannah.

    PubMed

    Vieira, Mariana L A; Johann, Susana; Hughes, Frederic M; Rosa, Carlos A; Rosa, Luiz H

    2014-12-01

    The fungal endophyte community associated with Baccharis trimera, a Brazilian medicinal plant, was characterized and screened for its ability to present antimicrobial activity. By using molecular methods, we identified and classified the endophytic fungi obtained into 25 different taxa from the phyla Ascomycota and Basidiomycota. The most abundant species were closely related to Diaporthe phaseolorum, Pestalotiopsis sp. 1, and Preussia pseudominima. The differences observed in endophytic assemblages from different B. trimera specimens might be associated with their crude extract activities. Plants that had higher ?-biodiversity were also those that contributed more to the regional (?) diversity. All fungal isolates were cultured and their crude extracts screened to examine the antimicrobial activities. Twenty-three extracts (12.8%) displayed antimicrobial activities against at least one target microorganism. Among these extracts, those obtained from Epicoccum sp., Pestalotiopsis sp. 1, Cochliobolus lunatus, and Nigrospora sp. presented the best minimum inhibitory concentration values. Our results show that the endophytic fungal community associated with the medicinal plant B. trimera included few dominant bioactive taxa, which may represent sources of compounds with antifungal activity. Additionally, the discovery of these bioactive fungi in association with B. trimera suggests that Brazilian plants used as folk medicine may shelter a rich fungal diversity as well as taxa able to produce bioactive metabolites with antimicrobial activities. PMID:25403761

  11. Effect of plant essential oils on antimicrobial and physical properties of apple-puree, edible films and coatings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of edible films as carriers of antimicrobial plant essential oils and other phytochemicals constitutes an approach for external protection of food systems to reduce surface microbial populations and to enhance oxygen-barrier properties, thus enhancing food safety as well as shelf life. The o...

  12. Prevalence, Serotype, and Antimicrobial Resistance of Salmonella on Broiler Carcasses Postpick and Postchill in 20 U. S. Processing Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to measure the effect of broiler processing on the prevalence, serotype and antimicrobial resistance profiles of salmonellae. Twenty US commercial processing plants representing eight integrators in thirteen states were included in the survey. In each of four replic...

  13. Potential of the essential oil from Pimenta pseudocaryophyllus as an antimicrobial agent.

    PubMed

    Suzuki, Érika Yoko; Baptista, Edilene Bolutari; Resende Do Carmo, Antônio Márcio; Miranda Chaves, Maria Das Graças Afonso; Chicourel, Elizabeth Lemos; Barbosa Raposo, Nádia Rezende

    2014-09-01

    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 ?g 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. PMID:25296683

  14. Sarothrin from Alkanna orientalis is an antimicrobial agent and efflux pump inhibitor.

    PubMed

    Bame, Jessica R; Graf, Tyler N; Junio, Hiyas A; Bussey, R Owen; Jarmusch, Scott A; El-Elimat, Tamam; Falkinham, Joseph O; Oberlies, Nicholas H; Cech, Richard A; Cech, Nadja B

    2013-03-01

    An Alkanna orientalis leaf and flower extract inhibited the growth of Staphylococcus aureus, a pathogen that causes an estimated 478 000 hospitalizations in the US annually. Bioassay-guided fractionation of A. orientalis resulted in isolation of the flavonoid sarothrin (5,7,4'-trihydroxy-3,6,8-trimethoxyflavone), which inhibited the growth of Mycobacterium smegmatis (MIC 75 µM) and S. aureus (MIC > 800 µM), and possessed efflux pump inhibitory activity. This is the first report of antimicrobial or efflux pump inhibitory activity of sarothrin, and of its presence in A. orientalis. Our findings suggest that the effectiveness of A. orientalis extracts is due to a combination of multiple constituents, including sarothrin. PMID:23468310

  15. Synthesis of Schiff bases of 4-(4-aminophenyl)-morpholine as potential antimicrobial agents.

    PubMed

    Panneerselvam, Perumal; Nair, Rajasree R; Vijayalakshmi, Gudaparthi; Subramanian, Ekambaram Harihara; Sridhar, Seshaiah Krishnan

    2005-02-01

    In the present study, a novel series of Schiff bases of 4-(4-aminophenyl)-morpholine were synthesised and characterised by IR, 1H-NMR, 13C-NMR, Mass spectral and elemental analysis. The compounds were screened for antibacterial (Staphylococcus aureus (ATCC 9144), Staphylococcus epidermidis (ATCC 155), Bacillus cereus (ATCC 11778), Micrococcus luteus (ATCC 4678), and Escherichia coli (ATCC 25922)) and antifungal (Candida albicans (ATCC 2091) and Aspergillus niger (ATCC 9029)) activities. The minimum inhibitory concentrations of the compounds were also ascertained by agar streak dilution method. 4-(4-(4-Hydroxy-benzylidene-imino)phenyl)-morpholine (7) was found to be the most potent antimicrobial activity with MIC of 25, 19, 21, 16, 29, 20 and 40 microg/ml against S. aureus, S. epidermidis, B. cereus, M. luteus, E. coli, C. albicans and A. niger, respectively. All the other compounds exhibited moderate activity against the bacterial and fungal organisms tested. PMID:15694658

  16. Poly(ethylene imine)s as antimicrobial agents with selective activity

    PubMed Central

    Gibney, Katherine; Sovadinova, Iva; Lopez, Analette I.; Urban, Michael; Ridgway, Zachary; Caputo, Gregory A.; Kuroda, Kenichi

    2014-01-01

    We report the structure-activity relationship in the antimicrobial activity of linear and branched poly(ethylene imine)s (L- and B-PEIs) with a range of molecular weights (MWs) (500–12,000). Both L- and B-PEIs displayed enhanced activity against Staphylococcus aureus over Escherichia coli. Both B- and L-PEIs did not cause any significant permeabilization of E. coli cytoplasmic membrane. L-PEIs induced depolarization of S. aureus membrane although B-PEIs did not. The low MW B-PEIs caused little or no hemolysis while L-PEIs are hemolytic. The low MW B-PEIs are less cytotoxic to human HEp-2 cells than other PEIs. However, they induced significant cell viability reduction after 24 hours incubation. The results presented here highlight the interplay between polymer size and structure on activity. PMID:22865776

  17. General principles of antimicrobial therapy.

    PubMed

    Leekha, Surbhi; Terrell, Christine L; Edson, Randall S

    2011-02-01

    Antimicrobial agents are some of the most widely, and often injudiciously, used therapeutic drugs worldwide. Important considerations when prescribing antimicrobial therapy include obtaining an accurate diagnosis of infection; understanding the difference between empiric and definitive therapy; identifying opportunities to switch to narrow-spectrum, cost-effective oral agents for the shortest duration necessary; understanding drug characteristics that are peculiar to antimicrobial agents (such as pharmacodynamics and efficacy at the site of infection); accounting for host characteristics that influence antimicrobial activity; and in turn, recognizing the adverse effects of antimicrobial agents on the host. It is also important to understand the importance of antimicrobial stewardship, to know when to consult infectious disease specialists for guidance, and to be able to identify situations when antimicrobial therapy is not needed. By following these general principles, all practicing physicians should be able to use antimicrobial agents in a responsible manner that benefits both the individual patient and the community. PMID:21282489

  18. General Principles of Antimicrobial Therapy

    PubMed Central

    Leekha, Surbhi; Terrell, Christine L.; Edson, Randall S.

    2011-01-01

    Antimicrobial agents are some of the most widely, and often injudiciously, used therapeutic drugs worldwide. Important considerations when prescribing antimicrobial therapy include obtaining an accurate diagnosis of infection; understanding the difference between empiric and definitive therapy; identifying opportunities to switch to narrow-spectrum, cost-effective oral agents for the shortest duration necessary; understanding drug characteristics that are peculiar to antimicrobial agents (such as pharmacodynamics and efficacy at the site of infection); accounting for host characteristics that influence antimicrobial activity; and in turn, recognizing the adverse effects of antimicrobial agents on the host. It is also important to understand the importance of antimicrobial stewardship, to know when to consult infectious disease specialists for guidance, and to be able to identify situations when antimicrobial therapy is not needed. By following these general principles, all practicing physicians should be able to use antimicrobial agents in a responsible manner that benefits both the individual patient and the community. PMID:21282489

  19. Antimicrobial activity of {gamma}-thionin-like soybean SE60 in E. coli and tobacco plants

    SciTech Connect

    Choi, Yeonhee [School of Biological Sciences, Seoul National University, Seoul 151-747 (Korea, Republic of)], E-mail: yhc@snu.ac.kr; Choi, Yang Do [Department of Agricultural Biotechnology and Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921 (Korea, Republic of); Lee, Jong Seob [School of Biological Sciences, Seoul National University, Seoul 151-747 (Korea, Republic of)], E-mail: jongslee@plaza.snu.ac.kr

    2008-10-17

    The SE60, a low molecular weight, sulfur-rich protein in soybean, is known to be homologous to wheat {gamma}-purothionin. To elucidate the functional role of SE60, we expressed SE60 cDNA in Escherichia coli and in tobacco plants. A single protein band was detected by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) after anti-FLAG affinity purification of the protein from transformed E. coli. While the control E. coli cells harboring pFLAG-1 showed standard growth with Isopropyl {beta}-D-1-thiogalactopyranoside (IPTG) induction, E. coli cells expressing the SE60 fusion protein did not grow at all, suggesting that SE60 has toxic effects on E. coli growth. Genomic integration and the expression of transgene in the transgenic tobacco plants were confirmed by Southern and Northern blot analysis, respectively. The transgenic plants demonstrated enhanced resistance against the pathogen Pseudomonas syringae. Taken together, these results strongly suggest that SE60 has antimicrobial activity and play a role in the defense mechanism in soybean plants.

  20. Ethnobotanical and antimicrobial study of some selected medicinal plants used in Khyber Pakhtunkhwa (KPK) as a potential source to cure infectious diseases

    PubMed Central

    2014-01-01

    Background Present investigation deals with antimicrobial screening of ten medicinally important plants used by the inhabitants of district Haripur, Khyber Pakhtunkhwa (KPK) for different infectious diseases. Methods Aqueous, n-hexane and ethanolic extracts of each plant were tested for their antimicrobial activity against both Gram positive and Gram negative strains of bacteria, as well as strain of yeast. Agar well diffusion and broth dilution methods were used to determine the antimicrobial activity of different plant extracts. Results The results indicated that all plants exhibited antimicrobial activity against one or more test pathogens. Interestingly, extracts of three plants showed strong and broad spectrum activity as compared to rest of the extracts which demonstrated the moderate activity. On the whole ethanolic extracts exhibited maximum antimicrobial effect than their corresponding aqueous and n-hexane extracts, when compared with standard antibiotics i.e., Streptomycin and Tetracycline. Among various extracts, only ethanloic extract of Azadirachta indica and aqueous and ethanolic extracts of Eucalyptus globulus and Bergenia ciliata and ethanolic extract of Punica granatum were found to have potentially promising activity against test microorganisms. Conclusion Different plant extracts show promising antimicrobial activity justifying their usage in traditional medicines. This study will be continued to identify more plants with potential antimicrobial components. PMID:24708514

  1. Antimicrobials in beekeeping.

    PubMed

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

    2012-07-01

    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. PMID:22342494

  2. In vitro antimicrobial activity of plants used in Cambodian traditional medicine.

    PubMed

    Chea, Aun; Jonville, Marie-Caroline; Bun, Sok-Siya; Laget, Michèle; Elias, Riad; Duménil, Gérard; Balansard, Guy

    2007-01-01

    The purpose of the present study was to screen 27 plant species used in the traditional medicine of Cambodia for in vitro antibacterial and antifungal activities. Thirty-three methanolic extracts were tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Mycobacterium smegmatis and Candida albicans. Screened by disk diffusion assay, the extracts showed antimicrobial activity especially on Gram-positive bacteria. None of the crude methanolic extracts showed activity against P. aeruginosa. Twenty-five selected extracts were evaluated using a micro-dilution test. Harrisonia perforata (roots) and Hymenodictyon excelsum (bark) exhibited a bactericidal effect against S. aureus at a concentration of 500 microg/ml. Azadirachta indica (bark), Harrisonia perforata (roots and stem) and Shorea obtusa (roots) exhibited a bactericidal effect against M. smegmatis at 250 microg/ml. PMID:17963325

  3. Synergy in a medicinal plant: Antimicrobial action of berberine potentiated by 5?-methoxyhydnocarpin, a multidrug pump inhibitor

    PubMed Central

    Stermitz, Frank R.; Lorenz, Peter; Tawara, Jeanne N.; Zenewicz, Lauren A.; Lewis, Kim

    2000-01-01

    Multidrug resistance pumps (MDRs) protect microbial cells from both synthetic and natural antimicrobials. Amphipathic cations are preferred substrates of MDRs. Berberine alkaloids, which are cationic antimicrobials produced by a variety of plants, are readily extruded by MDRs. Several Berberis medicinal plants producing berberine were found also to synthesize an inhibitor of the NorA MDR pump of a human pathogen Staphylococcus aureus. The inhibitor was identified as 5?-methoxyhydnocarpin (5?-MHC), previously reported as a minor component of chaulmoogra oil, a traditional therapy for leprosy. 5?-MHC is an amphipathic weak acid and is distinctly different from the cationic substrates of NorA. 5?-MHC had no antimicrobial activity alone but strongly potentiated the action of berberine and other NorA substrates against S. aureus. MDR-dependent efflux of ethidium bromide and berberine from S. aureus cells was completely inhibited by 5?-MHC. The level of accumulation of berberine in the cells was increased strongly in the presence of 5?-MHC, indicating that this plant compound effectively disabled the bacterial resistance mechanism against the berberine antimicrobial. PMID:10677479

  4. Synergy in a medicinal plant: antimicrobial action of berberine potentiated by 5'-methoxyhydnocarpin, a multidrug pump inhibitor.

    PubMed

    Stermitz, F R; Lorenz, P; Tawara, J N; Zenewicz, L A; Lewis, K

    2000-02-15

    Multidrug resistance pumps (MDRs) protect microbial cells from both synthetic and natural antimicrobials. Amphipathic cations are preferred substrates of MDRs. Berberine alkaloids, which are cationic antimicrobials produced by a variety of plants, are readily extruded by MDRs. Several Berberis medicinal plants producing berberine were found also to synthesize an inhibitor of the NorA MDR pump of a human pathogen Staphylococcus aureus. The inhibitor was identified as 5'-methoxyhydnocarpin (5'-MHC), previously reported as a minor component of chaulmoogra oil, a traditional therapy for leprosy. 5'-MHC is an amphipathic weak acid and is distinctly different from the cationic substrates of NorA. 5'-MHC had no antimicrobial activity alone but strongly potentiated the action of berberine and other NorA substrates against S. aureus. MDR-dependent efflux of ethidium bromide and berberine from S. aureus cells was completely inhibited by 5'-MHC. The level of accumulation of berberine in the cells was increased strongly in the presence of 5'-MHC, indicating that this plant compound effectively disabled the bacterial resistance mechanism against the berberine antimicrobial. PMID:10677479

  5. Udder pathogens and their resistance to antimicrobial agents in dairy cows in Estonia

    PubMed Central

    2011-01-01

    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 < 0.005). A significantly higher risk of 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 13.5%, respectively. Conclusions This study showed that the main pathogens associated with clinical mastitis were Str. uberis and E. coli. Subclinical mastitis was caused mainly by S. aureus and CNS. The number of S. aureus and Str. agalactiae isolates depended on herd size. Antimicrobial resistance was highly prevalent, especially penicillin resistance in S. aureus and CNS. PMID:21299911

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

    PubMed Central

    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. PMID:25566215

  7. Molecular genetic basis of antimicrobial agent resistance in Mycobacterium tuberculosis: 1998 update

    Microsoft Academic Search

    S. Ramaswamy; J. M. Musser

    1998-01-01

    Knowledge of the molecular genetic basis of resistance to antituberculous agents has advanced rapidly since we reviewed this topic 3 years ago. Virtually all isolates resistant to rifampin and related rifamycins have a mutation that alters the sequence of a 27-amino-acid region of the beta subunit of ribonucleic acid (RNA) polymerase. Resistance to isoniazid (INH) is more complex. Many resistant

  8. Effect of inoculum size and medium on activity of seven antimicrobial agents against Bacteroides fragilis strains.

    PubMed

    Wexler, H M; Reeves, D; Finegold, S M

    1989-01-01

    Antimicrobial activity of cefoxitin, cefotetan, cefotaxime, ceftizoxime, ceftazidime, imipenem, and clindamycin against four inocula of Bacteroides fragilis strains was determined on three different media. The inoculum sizes were 10(4), 10(5), 10(6), and 10(7) colony forming units (CFU) per spot. On all three media, substantial effects of inoculum size on minimal inhibitory concentrations (MIC) of cefotaxime and ceftizoxime were found: the doubled dilution differences in MICs between inocula of 10(7) and 10(4) CFU/spot were 2.2, 2.3, and 2.1 micrograms/ml of cefotaxime and 1.8, 4.4, and 4.0 micrograms/ml of ceftizoxime on Brucella base-laked blood agar, Wilkins-Chalgren agar, and a brain-heart infusion medium, respectively. An inoculum difference found on all three media with ceftazidime may also be of practical significance. There was evidence of larger differences between inocula on the Wilkins-Chalgren agar and brain-heart infusion than on the Brucella agar. PMID:2611824

  9. [Use of aminopenicillins: first cause of error in the prescription of antimicrobial agents at a hospital].

    PubMed

    Cartón, J A; Maradona, J A

    1989-03-01

    The patterns of use and quality of prescription of ampicillin and amoxycillin (A/A) as compared with the rest of antimicrobials (AM) was evaluated by means of the review of the therapeutic sheets of 4572 admitted patients, in coincidence with 5 calculations of prevalence in a university hospital. 25.7% of patients received AM. These were used in 865 instances, and 6% were disqualified. A/A participated in 57% of these errors (p = 0.002 as related with the rest of AM). 309 patients received AM as prophylactic drugs, and 70% of them did not comply with the standard rules. The election of A/A for prophylaxis was associated with 71% of these errors (p less than 0.0001). Nine out of every 10 prophylactic administrations of A/A were abnormal owing to incorrect indication (77%), dosage (10%), oral route (62%) or excessive duration (82%). The high prevalence of prescription of aminopenicillins (30%) was associated with 68% of the errors in the use of AM, owing, among other reasons, to the high resistance rates of the major recovered organisms excluding enterococci. The nonjustified overuse of aminopenicillins was the leading detected problem; it can be managed by a restrictive antibiotic policy and educational measures oriented to an adequate medical prescription. PMID:2716414

  10. Spiroplasmas: infectious agents of plants, arthropods and vertebrates.

    PubMed

    Bové, J M

    1997-08-01

    The spiroplasmas are mollicutes characterized by motility and helical morphology. They were discovered through studies on corn stunt and citrus stubborn diseases. The stubborn agent was the first mollicute of plant origin to be obtained in culture and the first cultured mollicute to possess a helical morphology. The citrus pathogen has been known as Spiroplasma citri since 1973. The corn stunt agent was cultured in 1975 and fully characterized as Spiroplasma kunkelii by 1986. The third and only other phytopathogenic spiroplasma is Spiroplasma phoeniceum, cultured from naturally infected periwinkle plants in Syria and described in 1986. These three spiroplasmas are restricted to the phloem sievetubes of the infected plants and are transmitted from plant by various phloem feeding leafhopper vectors in which the spiroplasmas multiply. Following the pioneering work on S. citri and S. kunkelii, close to fifty other spiroplasma species or proposed species have been discovered. All spiroplasmas have been isolated from insects, ticks and plants. Insects are particularly rich sources of spiroplasmas. Some insect-derived spiroplasmas are entomopathogens. S. melliferum and S. apis are honey bee pathogens. They cross the insect-gut barrier and reach the hemolymph, where they multiply abundantly and kill the bee. Spiroplasma floricola is the agent of lethargy disease of Melolontha melolontha (cockchafer). Spiroplasma poulsonii infects the neotropical species of Drosophila, is transmitted transovarially and kills the male progeny of an infected female fly, hence the name sex ratio spiroplasma. Some insect-derived spiroplasmas are also found on plant (flower) surfaces. For instance, S. apis was cultured from the surfaces of flowers growing in the vicinity of affected beehives. This suggests that the plant surface spiroplasmas are deposited on these surfaces by contaminated insects. Many insect spiroplasmas are not pathogenic, are often restricted to the gut and may be regarded as mutualists or incidental commensals. Of the three known tick spiroplasmas, only Spiroplasma mirum obtained from rabbit ticks is pathogenic to the vertebrate animal (chick embryo, new-born rodents, adult rabbit), but only upon experimental inoculation of the spiroplasma. Strain SMCA induces high incidence of cataracts in new born rodents. With strain GT-48 no cataracts are observed, but fatal encephalitis occurs. Spiral membranous inclusions resembling spiroplasmas have been seen in brain biopsies taken from patients with Creutzfeldt-Jakob disease. However, failure to detect spiroplasmas by serology and culture points to the absence of spiroplasmal involvement in spongiform encephalopathies. Transposon Tn 4001 mutagenesis has been applied for the first time to Spiroplasma citri, and pathogenicity can now be studied at the genetic level. One Tn 4001 mutant does not multiply in the leafhoppers and is, therefore, not transmitted to the plant. Another mutant multiplies well in the plant and is transmitted to the plant, where it reaches high titers, but without inducing symptoms in the plant. In this non-phytopathogenic mutant, Tn 4001 is inserted in the spiroplasmal fructose operon, and the mutant is unable to use fructose. Finally, to study involvement of spiroplasmal motility in pathogenicity, a non-motile mutant has been obtained. Motility was restored by complementation with the wild type genes. This is the first time that successful complementation has been reported, not only in the spiroplasmas but in the mollicutes in general. Undoubtedly, studies on pathogenicity have entered a new era. PMID:9286068

  11. Thin-layer chromatographic (TLC) separations and bioassays of plant extracts to identify antimicrobial compounds.

    PubMed

    Kagan, Isabelle A; Flythe, Michael D

    2014-01-01

    A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions. This paper describes standard protocols for TLC and contact bioautography with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light. Zones are cut out and incubated face down onto agar inoculated with the test microorganism. Inhibitory bands are visualized by staining the agar plates with tetrazolium red. The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen. The TLC methods apply to many types of plant extracts and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species. PMID:24747583

  12. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

    PubMed Central

    2012-01-01

    Background The Biopeptide BP100 is a synthetic and strongly cationic ?-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER), analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der) was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII) transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM) plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP), had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic ?-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM plants expressing, for example, BP100 based on inverted repeats, have adequate agronomic performance and resistant phenotypes as a result of a complex equilibrium between bp100der toxicity to plant cells, antimicrobial activity and transgene-derived plant stress response. It is likely that these results can be extended to other peptides with similar characteristics. PMID:22947243

  13. Disinfection of maxillofacial silicone elastomer using a novel antimicrobial agent: recombinant human beta-defensin-3.

    PubMed

    Shi, Y; Song, W; Feng, Z H; Zhao, Y T; Li, F; Tian, Y; Zhao, Y M

    2009-04-01

    Maxillofacial silicone elastomer, when used as a prosthesis, is in contact with wound surfaces and mucosa, and tends to be contaminated with microorganisms from a patient's saliva and blood. The aim of the study was to evaluate the efficacy of human beta-defensin-3 (HBD3) on the reduction of two resistant bacteria species from the surface of maxillofacial silicone elastomer. HBD3 cDNA was amplified from total RNA, which had been extracted from human gingival epithelium by means of reverse-transcription polymerase chain reaction (RT-PCR). Following this, the cDNA fragments were recombined in a prokaryotic expression vector. The constructed expression vectors pET-32a/HBD3 were transformed into Escherichia coli to obtain recombinant protein. After protein purification and refolding, the product was verified in classic antimicrobial experiments against Staphylococcus aureus and Candida albicans. Specimens made of silicone elastomer A-2186, which had been contaminated with S. aureus or C. albicans, were immersed in rHBD3 or 5.25% sodium hypochlorite (a positive control) for 5 min, 10 min, 30 min, or 60 min. The active recombinant HBD3 obtained in the current study eliminated the S. aureus and C. albicans microorganism from the surface of the maxillofacial elastomer after a 30-min immersion. There was no statistically significant difference between the rHBD3 group and the sodium hypochlorite 5.25% group. In conclusion, rHBD3 exhibits antibacterial activity against oral pathogenic strains that adhere to maxillofacial elastomer, and may, thus, contribute to the prevention of infections caused by S. aureus and C. albicans. PMID:18841402

  14. Essential oil from blackcurrant buds as chemotaxonomy marker and antimicrobial agent.

    PubMed

    Ethor?evi?, Boban S; Pljevljakuši?, Ðor?evi? S; Savikin, Katarina P; Stevi?, Tatjana R; Bigovi?, 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., ?-pinene (1.6-5.4%), sabinene (1.9-38.4%), ?-car-3-ene (13.0-50.7%), ?-phellandrene (2.9-18.0%), terpinolene (6.6-11.9%), terpinen-4-ol (0.9-6.6%), ?-caryophyllene (3.8-10.4%), and ?-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, ?-car-3-ene, and ?-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. PMID:25146766

  15. Medicinal plants from Peru: a review of plants as potential agents against cancer.

    PubMed

    Gonzales, Gustavo F; Valerio, Luis G

    2006-09-01

    Natural products have played a significant role in drug discovery and development especially for agents against cancer and infectious disease. An analysis of new and approved drugs for cancer by the United States Food and Drug Administration over the period of 1981-2002 showed that 62% of these cancer drugs were of natural origin. Natural compounds possess highly diverse and complex molecular structures compared to small molecule synthetic drugs and often provide highly specific biological activities likely derived from the rigidity and high number of chiral centers. Ethnotraditional use of plant-derived natural products has been a major source for discovery of potential medicinal agents. A number of native Andean and Amazonian medicines of plant origin are used as traditional medicine in Peru to treat different diseases. Of particular interest in this mini-review are three plant materials endemic to Peru with the common names of Cat's claw (Uncaria tomentosa), Maca (Lepidium meyenii), and Dragon's blood (Croton lechleri) each having been scientifically investigated for a wide range of therapeutic uses including as specific anti-cancer agents as originally discovered from the long history of traditional usage and anecdotal information by local population groups in South America. Against this background, we present an evidence-based analysis of the chemistry, biological properties, and anti-tumor activities for these three plant materials. In addition, this review will discuss areas requiring future study and the inherent limitations in their experimental use as anti-cancer agents. PMID:17017852

  16. Relationships of host plant phylogeny, chemistry and host plant specificity of several agents of yellow starthistle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant species used for host specificity testing are usually chosen based on the assumption that the risk of attack by a prospective biological control agent decreases with increasing phylogenetic distance from the target weed. Molecular genetics methods have greatly improved our ability to measure ...

  17. Antagonism of Azole Activity against Candida albicans following Induction of Multidrug Resistance Genes by Selected Antimicrobial Agents

    PubMed Central

    Henry, Karl W.; Cruz, M. Cristina; Katiyar, Santosh K.; Edlind, Thomas D.

    1999-01-01

    Antifungal azoles (e.g., fluconazole) are widely used for prophylaxis or treatment of Candida albicans infections in immunocompromised individuals, such as those with AIDS. These individuals are frequently treated with a variety of additional antimicrobial agents. Potential interactions between three azoles and 16 unrelated drugs (antiviral, antibacterial, antifungal, and antiprotozoal agents) were examined in vitro. Two compounds, tested at concentrations achievable in serum, demonstrated an antagonistic effect on azole activity against C. albicans. At fluconazole concentrations two to four times the 50% inhibitory concentration, C. albicans growth (relative to treatment with fluconazole alone) increased 3- to 18-fold in the presence of albendazole (2 ?g/ml) or sulfadiazine (50 ?g/ml). Antagonism (3- to 78-fold) of ketoconazole and itraconazole activity by these compounds was also observed. Since azole resistance has been correlated with overexpression of genes encoding efflux proteins, we hypothesized that antagonism results from drug-induced overexpression of these same genes. Indeed, brief incubation of C. albicans with albendazole or sulfadiazine resulted in a 3-to->10-fold increase in RNAs encoding multidrug transporter Cdr1p or Cdr2p. Zidovudine, trimethoprim, and isoniazid, which were not antagonistic with azoles, did not induce these RNAs. Fluphenazine, a known substrate for Cdr1p and Cdr2p, strongly induced their RNAs and, consistent with our hypothesis, strongly antagonized azole activity. Finally, antagonism was shown to require a functional Cdr1p. The possibility that azole activity against C. albicans is antagonized in vivo as well as in vitro in the presence of albendazole and sulfadiazine warrants investigation. Drug-induced overexpression of efflux proteins represents a new and potentially general mechanism for drug antagonism. PMID:10428921

  18. In vitro activity of nemonoxacin, tigecycline, and other antimicrobial agents against Helicobacter pylori isolates in Taiwan, 1998-2007.

    PubMed

    Yang, J-C; Lee, P-I; Hsueh, P-R

    2010-11-01

    The minimum inhibitory concentrations (MICs) of 330 nonduplicate Helicobacter pylori isolates to nemonoxacin, tigecycline, and eight other antimicrobial agents were determined by using the agar dilution method. Sequencing the quinolone resistance-determining regions (QRDRs) in the gyrA gene of these isolates was also performed. Resistance to clarithromycin showed an increasing trend during the ten-year study period and was highest (38%) in 2005. Tigecycline had potent in vitro activities against all isolates, with an MIC(90) of 0.06 ?g/ml. Among the quinolones tested, nemonoxacin (MIC(50) of 0.12 ?g/ml and MIC(90) of 0.25 ?g/ml) and gemifloxacin had one to two-fold better in vitro activities than ciprofloxacin, levofloxacin, and moxifloxacin. Among the nine isolates (2.7%) with levofloxacin resistance, four (44.4%) were also resistant to metronidazole, three (33.3%) to clarithromycin, and two (22.2%) to amoxicillin. Isolates with levofloxacin resistance exhibited one or two of three amino acid alterations (Ser-70, Asn-87, and Asp-91) involved in QRDRs in the gyrA gene. A double mutation at Ser70Cys and Asn87Ile had a higher level of resistance. The results of this study suggest a potentially useful role of nemonoxacin and tigecycline in the treatment of infections caused by H. pylori. The gyrA mutation at Ser-70 is a novel finding and has an impact on levofloxacin resistance. PMID:20658256

  19. Susceptibility to antimicrobial agents among bovine mastitis pathogens isolated from North American dairy cattle, 2002-2010.

    PubMed

    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. PMID:23907894

  20. Antimicrobial and cytotoxic activity of Ferula gummosa plant essential oil compared to NaOCl and CHX: a preliminary in vitro study

    PubMed Central

    Abbaszadegan, Abbas; Gholami, Ahmad; Saliminasab, Mina; Kazemi, Aboozar; Moein, Mahmood Reza

    2015-01-01

    Objectives The usage of medicinal plants as natural antimicrobial agents has grown in many fields including dental medicine. The aim of this in vitro study was three-fold: (i) to determine the chemical compositions of the Ferula gummosa essential oil (FGEO), (ii) to compare the antimicrobial efficacy of the oil with sodium hypochlorite (NaOCl) and chlorhexidine (CHX), (iii) to assess the toxic behavior of FGEO in different concentrations compared to 5% NaOCl and 0.2% CHX. Materials and Methods Gas chromatography/mass spectrometry (GC/MS) was used to determine the chemical compositions of the oil. The disk diffusion method and a broth micro-dilution susceptibility assay were exploited to assess the antimicrobial efficacy against Enterococcus faecalis, Staphylococcus aureus, Streptococcus mitis, and Candida albicans. The cytocompatibility of the FGEO was assessed on L929 fibroblasts, and compared to that of NaOCl and CHX. Results Twenty-seven constituents were recognized in FGEO. The major component of the oil was ?-pinene (51.83%). All three irrigants significantly inhibited the growth of all examined microorganisms compared to the negative control group. FGEO at 50 µg/mL was effective in lower concentration against Enterococcus faecalis than 5% NaOCl and 0.2% CHX, and was also more potent than 0.2% CHX against Candida albicans and Staphylococcus aureus. FGEO was a cytocompatible solution, and had significantly lower toxicity compared to 5% NaOCl and 0.2% CHX. Conclusions FGEO showed a promising biological potency as a root canal disinfectant. More investigations are required on the effectiveness of this oil on intracanal bacterial biofilms. PMID:25671213

  1. Antimicrobial activity of isothiocyanates from cruciferous plants against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Dias, Carla; Aires, Alfredo; Saavedra, Maria José

    2014-01-01

    Purified isothiocyanates from cruciferous plants (Brassicacea, Syn. Cruciferae) plants were evaluated against 15 isolates of methicillin-resistant S. aureus isolated from diabetic foot-ulcer patients aiming the study of the potential usage of allyl-isothiocyanate, benzyl-isothiocyanate and 2-phenylethyl-isothiocyanate against this important bacteria. Disc diffusion and minimum inhibitory concentration methods were used to access the antimicrobial activity. The index (Ia) and rate (Ra) of the antibacterial activity for each compound were calculated. The results showed a highly dose-dependent compound and chemical structure antibacterial effectiveness. The results showed a strong relation between the chemical structure of isothiocyanates and its antibacterial effectiveness. The benzyl-isothiocyanate was the most effective with a minimum inhibitory concentration varying between 2.9 and 110 µg·mL(-1) with an antibacterial activity rate up to 87%. Moreover, their antibacterial activity was mainly bactericidal. This study provides scientific evidence that isothiocyanates have an interesting biological value and must be considered as an important tool to be used against MRSA. PMID:25353177

  2. Antimicrobial Activity of Isothiocyanates from Cruciferous Plants against Methicillin-Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Dias, Carla; Aires, Alfredo; Saavedra, Maria José

    2014-01-01

    Purified isothiocyanates from cruciferous plants (Brassicacea, Syn. Cruciferae) plants were evaluated against 15 isolates of methicillin-resistant S. aureus isolated from diabetic foot-ulcer patients aiming the study of the potential usage of allyl-isothiocyanate, benzyl-isothiocyanate and 2-phenylethyl-isothiocyanate against this important bacteria. Disc diffusion and minimum inhibitory concentration methods were used to access the antimicrobial activity. The index (Ia) and rate (Ra) of the antibacterial activity for each compound were calculated. The results showed a highly dose-dependent compound and chemical structure antibacterial effectiveness. The results showed a strong relation between the chemical structure of isothiocyanates and its antibacterial effectiveness. The benzyl-isothiocyanate was the most effective with a minimum inhibitory concentration varying between 2.9 and 110 µg· mL?1 with an antibacterial activity rate up to 87%. Moreover, their antibacterial activity was mainly bactericidal. This study provides scientific evidence that isothiocyanates have an interesting biological value and must be considered as an important tool to be used against MRSA. PMID:25353177

  3. New Type of Antimicrobial Protein Produced by the Plant Pathogen Clavibacter michiganensis subsp. michiganensis

    PubMed Central

    Liu, Zhanliang; Ma, Ping; Holtsmark, Ingrid; Skaugen, Morten; Eijsink, Vincent G. H.

    2013-01-01

    It has previously been shown that the tomato pathogen Clavibacter michiganensis subsp. michiganensis secretes a 14-kDa protein, C. michiganensis subsp. michiganensis AMP-I (CmmAMP-I), that inhibits growth of Clavibacter michiganensis subsp. sepedonicus, the causal agent of bacterial ring rot of potato. Using sequences obtained from tryptic fragments, we have identified the gene encoding CmmAMP-I and we have recombinantly produced the protein with an N-terminal intein tag. The gene sequence showed that CmmAMP-I contains a typical N-terminal signal peptide for Sec-dependent secretion. The recombinant protein was highly active, with 50% growth inhibition (IC50) of approximately 10 pmol, but was not toxic to potato leaves or tubers. CmmAMP-I does not resemble any known protein and thus represents a completely new type of bacteriocin. Due to its high antimicrobial activity and its very narrow inhibitory spectrum, CmmAMP-1 may be of interest in combating potato ring rot disease. PMID:23851100

  4. Design and regioselective synthesis of trifluoromethylquinolone derivatives as potent antimicrobial agents.

    PubMed

    Garudachari, B; Isloor, Arun M; Satyanarayana, M N; Fun, Hoong-Kun; Pavithra, N; Kulal, Ananda

    2013-10-01

    Three series of new trifluoromethyl substituted quinolone derivatives were synthesized (4a-f, 6a-f and 8a-f) from corresponding substituted anilines by multi-step reactions. The regioselective alkylation with different alkyl halides were carried out by approaching two different routes to get the final products in good yield. Newly synthesized compounds were characterized by spectral study and also by C, H, N analyses. Three dimensional structure of 2b and 4b were also confirmed by single crystal X-ray studies. The final compounds (4a-f, 6a-f and 8a-f) were screened for their in-vitro antibacterial and antifungal activity by well plate method (zone of inhibition). The results revealed that, compounds 4a, 6b, 6c and 8e showed significant antibacterial activity as compared to the standard drug Ciprofloxacin. The compound 8a was found to be a potent antifungal agent. PMID:23994870

  5. Bactericidal effects of antimicrobial agents on epithelial cell-associated Pseudomonas aeruginosa.

    PubMed

    Hirakata, Yoichi; Yano, Hisakazu; Arai, Kazuaki; Kitagawa, Miho; Hatta, Masumitsu; Kunishima, Hiroyuki; Kaku, Mitsuo

    2012-06-01

    It is not clear whether antipseudomonal agents can kill cell-associated bacteria within a short time. Madin-Darby canine kidney (MDCK) and A549 cells were infected with Pseudomonas aeruginosa ATCC 27853 and PAO1 and the bactericidal activity of ceftazidime, imipenem, meropenem, gentamicin, and ciprofloxacin against the organisms was investigated. In both MDCK and A549 cells, ?-lactams could not kill epithelial cell-associated bacteria within 2 h. Gentamicin at concentrations ?32 ?g/ml killed more than 99% of epithelial cell-associated bacteria. Ciprofloxacin at 0.5 ?g/ml killed more than 99.9% of MDCK cell-associated bacteria. Ciprofloxacin has the strongest and most rapid bactericidal activity against epithelial cell-associated bacteria, which may be explained by the combination of potent in-vitro bactericidal activity and high penetration ability into epithelial cells. PMID:22116462

  6. Evaluating the toxic effect of an antimicrobial agent on single bacterial cells with optical tweezers

    PubMed Central

    Samadi, Akbar; Zhang, Chensong; Chen, Joseph; Reihani, S. N. S.; Chen, Zhigang

    2014-01-01

    We implement an optical tweezers technique to assess the effects of chemical agents on single bacterial cells. As a proof of principle, the viability of a trapped Escherichia coli bacterium is determined by monitoring its flagellar motility in the presence of varying concentrations of ethyl alcohol. We show that the “killing time” of the bacterium can be effectively identified from the correlation statistics of the positional time series recorded from the trap, while direct quantification from the time series or associated power spectra is intractable. Our results, which minimize the lethal effects of bacterial photodamage, are consistent with previous reports of ethanol toxicity that used conventional culture-based methods. This approach can be adapted to study other pairwise combinations of drugs and motile bacteria, especially to measure the response times of single cells with better precision. PMID:25657879

  7. [Prospects for the use of low-temperature gas plasma as an antimicrobial agent].

    PubMed

    Ermolaeva, S A; Petrov, O F; Miller, G G; Shaginian, I A; Naroditski?, B S; Sysoliatina, E V; Mukhachev, A Ia; Morfill, G E; Fortov, V E; Grigor'ev, A I; Gintsburg, A L

    2011-01-01

    Results of application of LTP at atmospheric pressure as an antibacterial agent during the last decade are considered with reference to physicochemical mechanisms of its bactericidal action. The principles of designing modern LTP sources are described in conjunction with the results of LTP application against pathogenic bacteria in vitro and in biofilms. The possibility to destroy biofilm matrix by LTP is estimated along with the results of its testing for the treatment of acute and chronic wound surfaces. Prospects for the development of "plasma medicine" in this country and abroad are discussed with special emphasis on its advantages, such as the absence of long-acting toxic compounds, small probability of spontaneous mutations accounting for resistance to LTP, relatively low cost of LTP sources, independence of LTP effect of the surface relief, painless application. PMID:22168034

  8. Potential applications of plant based derivatives as fat replacers, antioxidants and antimicrobials in fresh and processed meat products.

    PubMed

    Hygreeva, Desugari; Pandey, M C; Radhakrishna, K

    2014-09-01

    Growing concern about diet and health has led to development of healthier food products. In general consumer perception towards the intake of meat and meat products is unhealthy because it may increase the risk of diseases like cardiovascular diseases, obesity and cancer, because of its high fat content (especially saturated fat) and added synthetic antioxidants and antimicrobials. Addition of plant derivatives having antioxidant components including vitamins A, C and E, minerals, polyphenols, flavanoids and terpenoids in meat products may decrease the risk of several degenerative diseases. To change consumer attitudes towards meat consumption, the meat industry is undergoing major transformations by addition of nonmeat ingredients as animal fat replacers, natural antioxidants and antimicrobials, preferably derived from plant sources. PMID:24845336

  9. Phenolic characterization and antimicrobial activity of folk medicinal plant extracts for their applications in olive production.

    PubMed

    Boiteux, Joana; Soto Vargas, Carolina; Pizzuolo, Pablo; Lucero, Gabriela; Silva, María Fernanda

    2014-06-01

    Phytophthora spp is important in plant pathology due to the importance of the diseases it causes. In olive trees, severe damages are caused by the disease known as "dry branch" occasioned by Phytophthora nicotianae, P. citrophthora and P. palmivora. Much effort has been made to find efficient methods of control, with a low negative impact on environment. In this regard, treatment with plant extracts is a valid strategy. The aims of the present study are (i) to determine the polyphenol composition of extracts of Thymus vulgaris, Origanum vulgare, Matricaria recutita, and Larrea divaricata by CZE, (ii) correlate the analytical composition of these extracts with the inhibition on the mycelial growth, and (iii) determine the individual antimicrobial activity of the most active ingredients. A simple methodology was developed for the determination of catechin, naringenin, cinnamic acid, syringic acid, chlorogenic acid, apigenin, vanillic acid, luteolin, quercetin, and caffeic acid in plant extracts by CZE. The extraction of phenolic compounds in extract was performed by a miniaturized solid phase extraction using a home-made minicolumn packed with suitable filtering material (C18 , 50 mg). The optimized analyses conditions were: 30 mM boric acid buffer, pH 9.50; capillary, 57 cm full length, 50 cm effective length, 75 ?m id, hydrodynamic injection 30 mbar, 2 s; 25 kV; 25°C, detection by UV absorbance at 290 nm. Sample results suggest that phenolic composition seems to have a great influence on inhibition of pathogens. The highest inhibitions of mycelial growth were observed for cinnamic acid and naringenin. PMID:24668423

  10. Engineered plant biomass particles coated with biological agents

    DOEpatents

    Dooley, James H.; Lanning, David N.

    2014-06-24

    Plant biomass particles coated with a biological agent such as a bacterium or seed, characterized by a length dimension (L) aligned substantially parallel to a grain direction and defining a substantially uniform distance along the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L. In particular, the L.times.H dimensions define a pair of substantially parallel side surfaces characterized by substantially intact longitudinally arrayed fibers, the W.times.H dimensions define a pair of substantially parallel end surfaces characterized by crosscut fibers and end checking between fibers, and the L.times.W dimensions define a pair of substantially parallel top and bottom surfaces.

  11. Engineered plant biomass particles coated with bioactive agents

    DOEpatents

    Dooley, James H; Lanning, David N

    2013-07-30

    Plant biomass particles coated with a bioactive agent such as a fertilizer or pesticide, characterized by a length dimension (L) aligned substantially parallel to a grain direction and defining a substantially uniform distance along the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L. In particular, the L.times.H dimensions define a pair of substantially parallel side surfaces characterized by substantially intact longitudinally arrayed fibers, the W.times.H dimensions define a pair of substantially parallel end surfaces characterized by crosscut fibers and end checking between fibers, and the L.times.W dimensions define a pair of substantially parallel top and bottom surfaces.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25313139

  13. Synthesis of potent inhibitors of ?-ketoacyl-acyl carrier protein synthase III as potential antimicrobial agents.

    PubMed

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

    2012-01-01

    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 H??Rv. The results demonstrate that the compound 7d possesses good in vitro antimycobacterial activity against Mycobacterium tuberculosis H??Rv (Minimum Inhibitory Concentration value [MIC], 12.5 µg/mL).These compounds may prove useful in the discovery and development of new anti-tuberculosis drugs. PMID:22534662

  14. Bacteriophage PBC1 and Its Endolysin as an Antimicrobial Agent against Bacillus cereus.

    PubMed

    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. PMID:25595773

  15. Role of Antibiofilm-Antimicrobial Agents in Control of Device-Related Infections

    PubMed Central

    Aslam, Saima; Darouiche, Rabih O.

    2011-01-01

    Objectives To assess the effects of N-acetylcysteine (NAC) on organism viability in planktonic and biofilm phases, biofilm thickness, and extracellular polysaccharide content. Methods We performed time-kill curves and broth macrodilution assays of bacterial and fungal clinical isolates with varying concentrations of NAC. We also created in-vitro bacterial biofilms, incubated them with NAC or control, and then stained with propidium iodide and FITC-labelled concanavalin A. We measured biofilm thickness, number of non-viable cells, and fluorescent intensity as a marker of extracellular matrix via a confocal laser scanning microscope. All experiments were conducted in triplicate. Tested organisms included methicillin-sensitive and - resistant Staphylococcus aureus (MSSA, MRSA), S. epidermidis, vancomycin-resistant Enterococcus faecalis (VRE), Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae, Candida albicans and C. krusei. Results NAC 80 mg/ml was uniformly bactericidal (>99.9% reduction) against all tested bacteria with no recoverable organisms after 30 minutes of incubation, but was fungistatic against candida species. Minimum inhibitory and bactericidal concentrations of NAC ranged from 5–10 mg/ml. Biofilm thickness was significantly decreased in NAC-treated biofilms for all organisms except VRE. The number of non-viable cells in NAC-treated Gram-positive biofilms was increased (p<0.05 for MRSA and VRE). NAC-treated Gram-negative biofilms had scant cellularity and lacked complex 3-dimensional structures that were characteristic of controls. Fluorescent intensity was similar in the experimental and control arms. Conclusions NAC is bactericidal against clinically relevant and drug-resistant bacteria and also leads to biofilm disruption. NAC has the potential for use as a novel agent for prevention or treatment of biofilm-related infections. PMID:22094553

  16. The Human Milk Protein-Lipid Complex HAMLET Sensitizes Bacterial Pathogens to Traditional Antimicrobial Agents

    PubMed Central

    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 the lifetime of the current treatment arsenal. PMID:22905269

  17. A (2)H solid-state NMR study of the effect of antimicrobial agents on intact Escherichia coli without mutating.

    PubMed

    Tardy-Laporte, Catherine; Arnold, Alexandre A; Genard, Bertrand; Gastineau, Romain; Morançais, Michèle; Mouget, Jean-Luc; Tremblay, Réjean; Marcotte, Isabelle

    2013-02-01

    Solid-state nuclear magnetic resonance (NMR) is a useful tool to probe the organization and dynamics of phospholipids in bilayers. The interactions of molecules with membranes are usually studied with model systems; however, the complex composition of biological membranes motivates such investigations on intact cells. We have thus developed a protocol to deuterate membrane phospholipids in Escherichia coli without mutating to facilitate (2)H solid-state NMR studies on intact bacteria. By exploiting the natural lipid biosynthesis pathway and using perdeuterated palmitic acid, our results show that 76% deuteration of the phospholipid fatty acid chains was attained. To verify the responsiveness of these membrane-deuterated E. coli, the effect of known antimicrobial agents was studied. (2)H solid-state NMR spectra combined to spectral moment analysis support the insertion of the antibiotic polymyxin B lipid tail in the bacterial membrane. The use of membrane-deuterated bacteria was shown to be important in cases where antibiotic action of molecules relies on the interaction with lipopolysaccharides. This is the case of fullerenol nanoparticles which showed a different effect on intact cells when compared to dipalmitoylphosphatidylcholine/dipalmitoylphosphatidylglycerol membranes. Our results also suggest that membrane rigidification could play a role in the biocide activity of the detergent cetyltrimethyammonium chloride. Finally, the deuterated E. coli were used to verify the potential antibacterial effect of a marennine-like pigment produced by marine microalgae. We were able to detect a different perturbation of the bacteria membranes by intra- and extracellular forms of the pigment, thus providing valuable information on their action mechanism and suggesting structural differences. PMID:22989726

  18. Antimicrobial susceptibility pattern of bacterial isolates from wound infection and their sensitivity to alternative topical agents at Jimma University Specialized Hospital, South-West Ethiopia

    PubMed Central

    2014-01-01

    Background Wound infection is one of the health problems that are caused and aggravated by the invasion of pathogenic organisms. Information on local pathogens and sensitivity to antimicrobial agents, and topical agents like acetic acid is crucial for successful treatment of wounds. Objectives To determine antimicrobial susceptibility pattern of bacterial isolates from wound infection and their sensitivity to alternative topical agents at Jimma University Specialized Hospital. Methods A cross sectional study was conducted among patients with wound infection visiting Jimma University Specialized Hospital, from May to September 2013. Wound swab was collected using sterile cotton swabs and processed for bacterial isolation and susceptibility testing to antimicrobial agents, acetic acid, hydrogen peroxide and dabkin solution following standard bacteriological techniques. Biochemical tests were done to identify the species of the organisms. Sensitivity testing was done using Kirby- Baur disk diffusion method. Minimum inhibitory and bactericidal concentration was done using tube dilution method. Results In this study 145 bacterial isolates were recovered from 150 specimens showing an isolation rate of 87.3%. The predominant bacteria isolated from the infected wounds were Staphylococcus aureus 47 (32.4%) followed by Escherichia coli 29 (20%), Proteus species 23 (16%), Coagulase negative Staphylococci 21 (14.5%), Klebsiella pneumoniae 14 (10%) and Pseudomonas aeruginosa 11 (8%). All isolates showed high frequency of resistance to ampicillin, penicillin, cephalothin and tetracycline. The overall multiple drug resistance patterns were found to be 85%. Acetic acid (0.5%), Dabkin solution (1%) and 3% hydrogen peroxide were bactericidal to all isolated bacteria and lethal effect observed when applied for 10 minutes. Conclusions On in vitro sensitivity testing, ampicillin, penicillin, cephalothin and tetracycline were the least effective. Gentamicin, norfloxacin, ciprofloxacin, vancomycin and amikacin were the most effective antibiotics. Acetic acid (0.5%), dabkin solution (1%) and H2O2 (3%) were bactericidal to all isolates. PMID:24731394

  19. Antimicrobial activity of diterpenoids from hairy roots of Salvia sclarea L.: Salvipisone as a potential anti-biofilm agent active against antibiotic resistant Staphylococci

    Microsoft Academic Search

    ?. Ku?ma; M. Ró?alski; E. Walencka; B. Ró?alska; H. Wysoki?ska

    2007-01-01

    The antimicrobial activities of crude dichloromethane fractions from acetone extracts of Agrobacterium rhizogenes transformed roots and roots of field-grown plants of Salvia sclarea as well as four pure abietane diterpenoids isolated from the hairy root cultures were determined. The growth of Gram-positive bacteria (Staphylococcus aureus, S. epidermidis, Enterococcus faecalis) but not Gram-negative ones (Escherichia coli, Pseudomonas aeruginosa) or pathogenic fungi

  20. Effective Phages as Green Antimicrobial Agents Against Antibiotic-Resistant Hospital Escherichia coli

    PubMed Central

    Rahmani, Rana; Zarrini, Gholamreza; Sheikhzadeh, Farzam; Aghamohammadzadeh, Naser

    2015-01-01

    Background: Bacteriophages are viruses that attack bacteria and lead to their lysis in an efficient and highly specific manner. These natural enemies of bacteria were used as therapeutic agents before the advent of antibiotics. Currently, with the rapid spread of multi-drug resistant bacteria, phage therapy can be an effective alternative treatment for antibiotic resistant bacteria. Objectives: This study evaluated the effectiveness of bacteriophages in removing antibiotic-resistant clinical Escherichia coli strains in vitro and in vivo. Patients and Methods: Different samples were taken from bed sore and foot ulcers of patients with diabetes. E. coli strains were isolated and identified by standard methods. The antibiogram was ascertained using the Kirby Bauer disc diffusion method for ten antibiotics. The bacteriophages were isolated from environmental water samples. They were exposed to the host bacteria by the double-layer agar technique (DLA) to observe plaques. Cross reaction of the phages on test E. coli strains was performed to determine broader-spectrum phages. Phage TPR7 was selected for animal trials. Five groups of mice including a control group, bacterial group, phage group, antibiotic therapy group and phage therapy group, were examined. Results: Ten E. coli strains were isolated from hospital samples. They showed high resistance to the used antibiotics. An effective bacteriophage was isolated for each strain. The cross-reaction showed phages which affect more than six E. coli strains. They can be a good choice for clinical therapeutic use. In animal trials the group challenged with phages after being infected showed similar results as the group treated with gentamicin after being infected. In both groups infection was removed after 48 hours. Conclusions: According to the results, six strains were resistant to six or seven antibiotics and all strains were at least resistant to two antibiotics. However, for each of these resistant bacteria one bacteriophage was isolated from environmental samples, which showed the effectiveness of bacteriophages to remove clinically resistant E. coli strains. Effective phages in vitro showed effective results in vivo as well.

  1. Natural products as antibacterial agents

    Microsoft Academic Search

    Gail B. Mahady; Yue Huang; Brian J. Doyle; Tracie Locklear

    2008-01-01

    For thousands of years medicinal plants have played a significant role in the treatment of a wide range of medical conditions, including infectious diseases. Some naturally occurring chemical compounds serve as models for a large percentage clinically proven drugs, and many are now being re-assessed as antimicrobial agents. The primary reason for this renaissance is the fact that infectious disease

  2. Phytochemical screening and evaluation of Monechma ciliatum (black mahlab) seed extracts as antimicrobial agents

    PubMed Central

    Ahmed Oshi, Murtada; Mohmmed Abdelkarim, Abdelkarim

    2013-01-01

    Objective: Tribes in Nubia Mountains regions of Sudan used Monechma ciliatum seeds for common cold and other chest allergic conditions as a traditional medicine. The aim of this paper is to validate this traditional practice scientifically. Materials and Methods: Monechma ciliatum seeds were screened for major phytochemical groups using standard methods. Different extracts were bioassayed in- vitro for their bioactivity to inhibit the growth of pathogenic bacteria and fungi. Results: Phytochemical screening results showed the presence of flavonoids, tannins, triterpens, and anthraquinones. Staphylococcus aureus was found to be sensitive to both water extract with zones of inhibition 22 – 26 mm at concentrations of 50 and 100mg/ml and ethanol extract 17 mm at concentration of 100 mg/ml. The growth of Klebsiella pneumoniae was inhibited by ethanol extract with zones of inhibition equal to 16, 26, and 33 mm at concentrations of 50, 100, and 150 mg/ml, respectively. Pseudomonas aeruginosa was insensitive to all extracts used. Similarly, all used fungi were found to be insensitive to extracts used. The minimum inhibitory concentrations of the extracts against microorganisms were ranged from 12.5 to 25 mg/ml. Conclusion: The findings of the current study support the traditional uses of the plant's seed in the therapy of respiratory tract infections caused by Staphylococcus aureus and Klebsiella pneumoniae. PMID:25050266

  3. Approaches towards the synthesis of a novel class of 2-amino-5-arylazonicotinate, pyridazinone and pyrido[2,3-d]pyrimidine derivatives as potent antimicrobial agents

    PubMed Central

    2013-01-01

    Background Despite significant progresses in antimicrobial therapy, infectious diseases caused by bacteria and fungi remain a major worldwide health problem because of the rapid development of resistance to existing antimicrobial drugs. Therefore, there is a constant need for new antimicrobial agents. There are a large number of heterocyclic derivatives containing nitrogen atoms that possess a broad spectrum of biological activities including pyridine and pyridazine, which are two of the most important heterocycles in medicinal chemistry. Results The reaction of 3-oxo-2-arylhydrazonopropanals 2 with ethyl cyanoacetate and malononitrile 3a,b has led to the formation of 2-amino-5-arylazo-6-aryl substituted nicotinates 8a-k as sole isolable products when the aryl group in the arylazo moiety was substituted with an electron-withdrawing group like Cl, Br, NO2. The pyridazinones 10 were formed from the same reaction when the arylazo moiety was phenyl or phenyl substituted with an electron-donating group. The 2-aminoazonicotinates 8 were condensed with DMF-DMA to afford the amidines 13a,b, which then were cyclized to afford the targeted pyrido[2,3-d]pyrimidine derivatives 15a,b, respectively. The structures of all new substances prepared in this investigation were determined by using X-ray crystallographic analysis and spectroscopic methods. Most of the synthesized compounds were tested and evaluated as antimicrobial agents and the results indicated that many of the obtained compounds exhibited high antimicrobial activity comparable to ampicillin, which was used as the reference compound. Conclusion A general rule for the synthesis of 2-amino-5-arylazo-6-aryl substituted nicotinic acid and pyridazinone was established using 3-oxo-2-arylhydrazonopropanal as a precursor. Moreover, a novel route to pyrido[2,3-d]pyrimidine was achieved. Most of the synthesized compounds were found to exhibit strong inhibitory effects on the growth of Gram-positive bacteria especially Bacillus subtilis. Compounds 1a, 8a-h, 10a-c, 15b and 16 showed a broad spectrum of antimicrobial activity against B. subtilis. PMID:23867062

  4. Antimicrobial Use and Antimicrobial Resistance: A Population Perspective

    Microsoft Academic Search

    Marc Lipsitch; Matthew H. Samore

    2002-01-01

    The need to stem the growing problem of antimicrobial resistance has prompted multiple, sometimes con- flicting, calls for changes in the use of antimicrobial agents. One source of disagreement concerns the major mechanisms by which antibiotics select resistant strains. For infections like tuberculosis, in which resistance can emerge in treated hosts through mutation, prevention of antimicrobial resistance in individ- ual

  5. Potency of Anidulafungin Compared to Nine Other Antifungal Agents Tested against Candida spp., Cryptococcus spp., and Aspergillus spp.: Results from the Global SENTRY Antimicrobial Surveillance Program (2008) ?

    PubMed Central

    Messer, Shawn A.; Jones, Ronald N.; Moet, Gary J.; Kirby, Jeffrey T.; Castanheira, Mariana

    2010-01-01

    The SENTRY Antimicrobial Surveillance Program regularly monitors global susceptibility rates for a spectrum of both novel and established antifungal agents. Anidulafungin and the other echinocandins displayed sustained, excellent activity against Candida spp. and Aspergillus fumigatus, with ?98% of MIC results at ?2 ?g/ml. Six yeast isolates (all Candida glabrata) showing caspofungin MIC values of ?0.5 ?g/ml were further analyzed for potential fks hot spot (HS) mutations; three isolates had confirmed mutations in the fks1 HS1 region (S645P), and three exhibited mutations in the fks2 HS1 region (S645F and S645P). PMID:20534798

  6. Metabolization of the bacteriostatic agent triclosan in edible plants and its consequences for plant uptake assessment.

    PubMed

    Macherius, André; Eggen, Trine; Lorenz, Wilhelm; Moeder, Monika; Ondruschka, Jelka; Reemtsma, Thorsten

    2012-10-01

    Persistent environmental contaminants may enter agricultural fields via the application of sewage sludge, by irrigation with treated municipal wastewater or by manuring. It has been shown that such contaminants can be incorporated into crop plants. The metabolism of the bacteriostatic agents triclocarban, triclosan, and its transformation product methyl triclosan was investigated after their uptake into carrot cell cultures. A fast metabolization of triclosan was observed and eight so far unknown phase II metabolites, conjugates with saccharides, disaccharides, malonic acid, and sulfate, were identified by liquid chromatography-mass spectrometry. Triclocarban and methyl triclosan lack a phenolic group and remained unaltered in the cell cultures. Phase I metabolization was not observed for any of the compounds. All eight triclosan conjugates identified in the cell cultures were also detected in extracts of intact carrot plants cultivated on triclosan contaminated soils. Their total amount in the plants was assessed to exceed the amount of the triclosan itself by a factor of 5. This study shows that a disregard of conjugates in studies on plant uptake of environmental contaminants may severely underestimates the extent of uptake into plants and, eventually, the potential human exposure to contaminants via food of plant origin. PMID:22989227

  7. Real-Time Based Agent Architecture for Power Plant Control

    Microsoft Academic Search

    Joel H. Van Sickel; Kwang Y. Lee

    2009-01-01

    Building upon the work of the multi-agent system (MAS) based intelligent heuristic optimal control system (MAS-IHOCS) a new distributed real-time agent framework with time-warp (DRAFT) has been developed to enhance performance and development of multi-agent systems used to control real time processes. Using distributed discrete event simulation techniques for optimistic simulation with time-warp speeds up the simulation of the multi-agent

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

    PubMed Central

    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

    Background Development of an environmentally benign process for the synthesis of silver nanomaterials is an important aspect of current nanotechnology research. Among the 600 species of the genus Dioscorea, Dioscorea bulbifera has profound therapeutic applications due to its unique phytochemistry. In this paper, we report on the rapid synthesis of silver nanoparticles by reduction of aqueous Ag+ ions using D. bulbifera tuber extract. Methods and results Phytochemical analysis revealed that D. bulbifera tuber extract is rich in flavonoid, phenolics, reducing sugars, starch, diosgenin, ascorbic acid, and citric acid. The biosynthesis process was quite fast, and silver nanoparticles were formed within 5 hours. Ultraviolet-visible absorption spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, and x-ray diffraction confirmed reduction of the Ag+ ions. Varied morphology of the bioreduced silver nanoparticles included spheres, triangles, and hexagons. Optimization studies revealed that the maximum rate of synthesis could be achieved with 0.7 mM AgNO3 solution at 50°C in 5 hours. The resulting silver nanoparticles were found to possess potent antibacterial activity against both Gram-negative and Gram-positive bacteria. Beta-lactam (piperacillin) and macrolide (eryth-romycin) 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. PMID:22334779

  9. Antimicrobial properties and phytochemical constituents of the leaves of African mistletoe ( Tapinanthus dodoneifolius (DC) Danser) (Loranthaceae): an ethnomedicinal plant of Hausaland, Northern Nigeria

    Microsoft Academic Search

    Y. Y Deeni; N. M Sadiq

    2002-01-01

    African mistletoe (Tapinanthusdodoneifolius (DC) Danser) called ‘Kauchi’ in Hausa is a hemi-plant parasite used ethnomedicinally by the Hausa and the Fulani tribes of Northern Nigeria as a remedy for several human and animal ailments that include stomach ache, diarrhoea, dysentery, wound and cancer. Screening of the plant, obtained from 14 different hosts, revealed a wide spectrum of antimicrobial activities against

  10. Repositioning Antimicrobial Agent Pentamidine as a Disruptor of the Lateral Interactions of Transmembrane Domain 5 of EBV Latent Membrane Protein 1

    PubMed Central

    Wang, Xiaohui; Fiorini, Zeno; Smith, Christina; Zhang, Yingning; Li, Jing; Watkins, Linda R.; Yin, Hang

    2012-01-01

    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. PMID:23094078

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

    PubMed Central

    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 ?g/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

  12. Antimicrobial activity of plant essential oils against bacterial and fungal species involved in food poisoning and/or food decay.

    PubMed

    Lixandru, Brîndu?a-Elena; Dr?cea, Nicoleta Olgu?a; Dragomirescu, Cristiana Cerasella; Dr?gulescu, Elena Carmina; Coldea, Ileana Lumini?a; Anton, Liliana; Dobre, Elena; Rovinaru, Camelia; Codi??, Irina

    2010-01-01

    The currative properties of aromatic and medicinal plants have been recognized since ancient times and, more recently, the antimicrobial activity of plant essential oils has been used in several applications, including food preservation. The purpose of this study was to create directly comparable, quantitative data on the antimicrobial activity of some plant essential oils prepared in the National Institute of Research-Development for Chemistry and Petrochemistry, Bucharest to be used for the further development of food packaging technology, based on their antibacterial and antifungal activity. The essential oils extracted from thyme (Thymus vulgaris L.), basil (Ocimum basilicum L.), coriander (Coriandrum sativum L.), rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.), fennel (Foeniculum vulgare L.), spearmint (Mentha spicata L.) and carraway (Carum carvi L.) were investigated for their antimicrobial activity against eleven different bacterial and three fungal strains belonging to species reported to be involved in food poisoning and/or food decay: S. aureus ATCC 25923, S. aureus ATCC 6538, S. aureus ATCC 25913, E. coli ATCC 25922, E. coli ATCC 35218, Salmonella enterica serovar Enteritidis Cantacuzino Institute Culture Collection (CICC) 10878, Listeria monocytogenes ATCC 19112, Bacillus cereus CIP 5127, Bacillus cereus ATCC 11778, Candida albicans ATCC 10231, Aspergillus niger ATCC 16404, Penicillium spp. CICC 251 and two E. coli and Salmonella enterica serovar Enteritidis clinical isolates. The majority of the tested essential oils exibited considerable inhibitory capacity against all the organisms tested, as supported by growth inhibition zone diameters, MICs and MBC's. Thyme, coriander and basil oils proved the best antibacterial activity, while thyme and spearmint oils better inhibited the fungal species. PMID:21462837

  13. Ethnomedicinal and phytochemical review of Pakistani medicinal plants used as antibacterial agents against Escherichia coli

    PubMed Central

    2014-01-01

    Medicinal plants have always been part of human culture and have the potential to cure different diseases caused by microorganisms. In Pakistan, biologists are mainly focusing on plantsantimicrobial activities against Escherichia coli due to its increasing resistance to antibiotics. In total, extracts from 34 ethnomedicinally valuable Pakistani plants were reported for in-vitro anti-E. coli activities. Mostly methanolic extracts of medicinal plants were used in different studies, which have shown comparatively higher inhibitory activities against E. coli than n-hexane and aqueous extracts. It has been found that increasing concentration (mg/ml) of methanolic extract can significantly increase (p plants are extracted in solvents others than above, which should also be tested against E. coli. Moreover, medicinal plant species must be fully explored phytochemically, which may lead to the development of new drugs. PMID:25135359

  14. Ethnomedicinal and phytochemical review of Pakistani medicinal plants used as antibacterial agents against Escherichia coli.

    PubMed

    Adnan, Muhammad; Bibi, Roqaia; Mussarat, Sakina; Tariq, Akash; Shinwari, Zabta Khan

    2014-01-01

    Medicinal plants have always been part of human culture and have the potential to cure different diseases caused by microorganisms. In Pakistan, biologists are mainly focusing on plants' antimicrobial activities against Escherichia coli due to its increasing resistance to antibiotics. In total, extracts from 34 ethnomedicinally valuable Pakistani plants were reported for in-vitro anti-E. coli activities. Mostly methanolic extracts of medicinal plants were used in different studies, which have shown comparatively higher inhibitory activities against E. coli than n-hexane and aqueous extracts. It has been found that increasing concentration (mg/ml) of methanolic extract can significantly increase (p<0.01) anti-E. coli activities. Not all medicinal plants are extracted in solvents others than above, which should also be tested against E. coli. Moreover, medicinal plant species must be fully explored phytochemically, which may lead to the development of new drugs. PMID:25135359

  15. Longitudinal analysis of the association of human salivary antimicrobial agents with caries increment and cariogenic micro-organisms: a two-year cohort study.

    PubMed

    Kirstilä, V; Häkkinen, P; Jentsch, H; Vilja, P; Tenovuo, J

    1998-01-01

    Previous studies of the possible associations of salivary antimicrobial agents with dental caries have given controversial results, obviously mainly because almost all studies have been cross-sectional. Our aim was to find out, in a two-year longitudinal follow-up study, the associations among selected salivary non-immune and immune antimicrobial variables, cariogenic bacteria, and caries increment. The study population was comprised of 63 subjects, all of whom had their 13th birthday during the first study year. In addition to a comprehensive dental examination at baseline and after 2 yrs, paraffin-stimulated whole saliva samples were collected in a standardized way at six-month intervals. Saliva samples were analyzed for flow rate, buffer effect, lysozyme, lactoferrin, total peroxidase activity, hypothiocyanite, thiocyanate, agglutination rate, and total and specific anti-S. mutans IgA and IgG, as well as for numbers of total and mutans streptococci, lactobacilli, and total anaerobic bacteria. Cluster analysis and Spearman-Rank correlation coefficients were used to explore possible associations between and among the studied variables. During the two-year period, a statistically significant increase was observed in flow rate, thiocyanate, agglutination rate, anti-S. mutans IgA antibodies, lactobacilli, and total anaerobes, whereas lysozyme, lactoferrin, and total and anti-S. mutans IgG antibodies declined significantly. Based on various analyses, it can be concluded that, at baseline, total IgG and hypothiocyanite had an inverse relationship with subsequent two-year caries increment, anti-S. mutans IgG antibodies increased with caries development, and mutans streptococci and lactobacilli correlated positively with both baseline caries and caries increment. Total anaerobic microflora was consistently more abundant among caries-free individuals. In spite of the above associations, we conclude that none of the single antimicrobial agents as such has sufficiently strong power to have diagnostic significance in vivo with respect to future caries. PMID:9437402

  16. TiO2 nanotube arrays deposited on Ti substrate by anodic oxidation and their potential as a long-term drug delivery system for antimicrobial agents

    NASA Astrophysics Data System (ADS)

    Moseke, Claus; Hage, Felix; Vorndran, Elke; Gbureck, Uwe

    2012-05-01

    Nanotube arrays on medical titanium surfaces were fabricated by two different anodization methods and their potential for storage and release of antimicrobial substances was evaluated. The treatment of the Ti surfaces in fluoride containing electrolytes on water as well as on polyethylene glycol basis led to the formation of TiO2 nanotubes with up to 6.54 ?m length and average diameters of up to 160 nm. Drug release experiments with the model antibiotic vancomycin and with antibacterial silver ions showed that the increased surface area of the anodized samples enabled them to be loaded with up to 450% more active agent than the untreated Ti surfaces. Significant surface-dependent differences in the release kinetics of vancomycin were observed. In comparison to surfaces anodized in an aqueous electrolyte, the release of the antibiotic from surfaces anodized in an electrolyte based on ethylene glycol was significantly retarded, with a release of noticeable amounts over a period of more than 300 days. Loading of nanotube surfaces fabricated in aqueous electrolyte with silver ions revealed increased amounts of adsorbed silver by up to 230%, while the release kinetics showed significant differences in comparison to untreated Ti. It was concluded that nanotube arrays on favored medical implant materials have a high potential for loading with antimicrobial agents and also provide the possibility of tailored release kinetics by variation of anodization parameters.

  17. Antimicrobial Peptides

    PubMed Central

    Bahar, Ali Adem; Ren, Dacheng

    2013-01-01

    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). PMID:24287494

  18. Absorbent silver (I) antimicrobial fabrics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. Antimicrobial Activity of Lippia Species from the Brazilian Semiarid Region Traditionally Used as Antiseptic and Anti-Infective Agents

    PubMed Central

    Pinto, Cristiana da Purificação; Rodrigues, Velize Dias; Pinto, Fernanda da Purificação; Pinto, Renata da Purificação; Uetanabaro, Ana Paula Trovatti; Pinheiro, Carla Santos Ribeiro; Gadea, Suzana Ferreira Magalhães; Silva, Tânia Regina dos Santos; Lucchese, Angélica Maria

    2013-01-01

    Lippia origanoides Kunth, Lippia alnifolia Schauer, and Lippia thymoides Martius and Schauer are shrubs used in the traditional Brazilian medicine as antiseptics, as well as in the treatment of infectious diseases. This study was designed to investigate the antibacterial and antifungal activities of the methanolic extracts of these species, as new potential sources of antimicrobial drugs. The antimicrobial activity of methanolic extracts was investigated against resistant yeasts and bacteria by agar disk diffusion. Then, the MIC determination of the most active species and its fractions in hexane, dichloromethane, ethyl acetate, and water was performed. By the agar diffusion assay, all species were active against at least two microorganisms, giving evidence to support their use in the popular medicine. L. origanoides leaves exhibited the widest antimicrobial action, inhibiting the growth of two Gram-positive bacteria and two yeasts; this activity was also confirmed by the MIC evaluation. The fractionation of L. origanoides crude extracts improved the activity in spectrum and intensity. The results obtained in this study indicate that L. origanoides may be a promising alternative in the treatment of bacterial and fungal infections and in the seeking of new antimicrobial drugs. PMID:24109492

  20. Antimicrobial peptides from plants: stabilization of the ? core of a tomato defensin by intramolecular disulfide bond.

    PubMed

    Avitabile, C; Capparelli, R; Rigano, M M; Fulgione, A; Barone, A; Pedone, C; Romanelli, A

    2013-04-01

    Cysteine-containing antimicrobial peptides of diverse phylogeny share a common structural signature, the ? core, characterized by a strong polarization of charges in two antiparallel ? sheets. In this work, we analyzed peptides derived from the tomato defensin SolyC07g007760 corresponding to the protein ? core and demonstrated that cyclization of the peptides, which results in segregation of positive charges to the turn region, produces peptides very active against Gram negative bacteria, such as Salmonella enterica and Helicobacter pylori. Interestingly, these peptides show very low hemolytic activity and thus represent a scaffold for the design of new antimicrobial peptides. PMID:23420649

  1. Assessment of long-term storage on antimicrobial and cyclooxygenase-inhibitory properties of South African medicinal plants.

    PubMed

    Amoo, Stephen O; Aremu, Adeyemi O; Moyo, Mack; Van Staden, Johannes

    2013-07-01

    In traditional medicine, plant materials are often stored by traditional healers, plant gatherers and traders before they are eventually consumed or sold. The critical point is whether stored medicinal plants are as active as freshly harvested dried material. We evaluated the effects of long-term storage (12 or 16?years) on the antimicrobial (microplate dilution method) and anti-inflammatory (COX-1 and COX-2 inhibition) potencies of 21 extensively used traditional medicinal plants in treating pain and infection-related ailments. The minimum inhibitory concentration (MIC) values obtained against Staphylococcus aureus and Pseudomonas aeruginosa in the stored plant materials were generally either lower or roughly the same as in the fresh material. Most of the stored plant material had comparable minimum microbicidal concentration (MMC) values as the fresh material against S. aureus and P. aeruignosa. Similarly, the majority (71%) of the stored plant material had similar MIC and/or MMC values as fresh material against the fungus Candida albicans. The percentage inhibition of COX-1 by the majority (88%) of the stored material was not significantly different when compared to those freshly collected. Stored material of Clausena anisata, Ekebergia capensis and Trichilia dregeana showed a significantly higher COX-1 inhibition than the fresh material. The therapeutic and conservation implications of the results are discussed. PMID:22933443

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

    PubMed

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

    2015-01-01

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

  3. Multicenter study in Taiwan of the in vitro activities of nemonoxacin, tigecycline, doripenem, and other antimicrobial agents against clinical isolates of various Nocardia species.

    PubMed

    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=gemifloxacinantimicrobial 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

  4. ANTIMICROBIAL SUSCEPTIBILITY OF BACTERIAL CONTAMINANTS FROM A WET-MILL ETHANOL PLANT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contamination of commercial fermentation cultures is a recurring problem in the fuel ethanol industry. Although some facilities use antimicrobials to control contamination, there are little data available to assess the value of such treatments. As part of a broader study to determine the efficacy ...

  5. ANTIMICROBIAL SUSCEPTIBILITY OF LACTOBACILLUS SPECIES ISOLATED FROM FUEL-ETHANOL PLANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial contamination of commercial fermentation cultures is a common and costly problem to the fuel ethanol industry. Antimicrobials such as tetracycline (TET), penicillin G (PEN), and virginiamycin (VIR) are frequently used to control contamination but there are little data available on the sus...

  6. Evaluation of the in vitro anticancer, antimicrobial and antioxidant activities of some Yemeni plants used in folk medicine.

    PubMed

    Mothana, R A A; Gruenert, R; Bednarski, P J; Lindequist, U

    2009-04-01

    The present research study deals with the evaluation of sixty four methanolic and aqueous extracts of thirty Yemeni plants used in traditional medicine for their in vitro antiproliferative activity against three human cancer cell lines in a microtiter plate assay based on cellular staining with crystal violet, for their antimicrobial activity against antibiotic susceptible three Gram-positive, three Gram-negative bacterial and one fungal stains and three multiresistant Staphylococcus strains by the agar diffusion method and the determination of MIC against three Gram-positive bacteria with the broth micro-dilution assay, as well as for their antioxidant activity using the DPPH radical scavenging method. Furthermore the chemical composition of the methanolic extracts was determined by using chromatographic methods. As a result of this work, 12 Yemeni herbs namely Centaurothamus maximus, Costus arabicus, Cupressus sempervirens, Dichrocephala integrifolia, Euphorbia schimperi, Gomphocarpus fruticosus, Kanahia laniflora, Meriandera benghalensis, Pulicaria inuloides, Solanum glabratum, Tarconanthus camphoratus and Vernonia leopoldii demonstrated a noteworthy growth inhibitory effect against all cancer cell lines with IC50 values <50 microg/ml. Pronounced antimicrobial activity was observed only against Gram-positive bacteria among them multiresistant bacteria with inhibition zones >15 mm and MIC values <500 microg/ml, by 9 plants especially Centaurothamus maximus, Cupressus sempervirens, Enicostemma verticillare, Meriandera benghalensis, Nepeta deflersiana, Pulicaria inuloides, Tarconanthus camphoratus, Teucrium yemense and Vernonia leopoldii. Moreover, the methanolic extracts of Cupressus sempervirens, Meriandera benghalensis, Pulicaria inuloides and Rhus retinorrhaea showed a remarkable radical scavenging effect at low concentrations. PMID:19435146

  7. The intrinsic resistance of Escherichia coli to various antimicrobial agents requires ppGpp and sigma s.

    PubMed

    Greenway, D L; England, R R

    1999-11-01

    We have examined the effect of a wide range of antimicrobial compounds (antibiotics and biocides) on the growth of various strains of Escherichia coli which vary in their ability to produce ppGpp and sigma s. We conclude that strains able to synthesize ppGpp, either in a RelA- or SpoT-dependent manner, possess a greater resistance to antimicrobial compounds compared with strains that cannot produce ppGpp. Investigation of an E. coli strain, unable to produce sigma s, and an isogenic parent strain, suggests that there is a requirement for this sigma factor in increased expression of intrinsic resistance. We propose that ppGpp is required to induce production of sigma s, which in turn directs gene expression of intrinsic resistance determinants. PMID:10664973

  8. Broth Microdilution Susceptibility Testing of Campylobacter jejuni and the Determination of Quality Control Ranges for Fourteen Antimicrobial Agents

    PubMed Central

    McDermott, Patrick F.; Bodeis-Jones, Sonya M.; Fritsche, Thomas R.; Jones, Ronald N.; Walker, Robert D.; Campylobacter Susceptibility Testing Group, the

    2005-01-01

    Quality control ranges were developed for broth microdilution testing of Campylobacter jejuni ATCC 33560 against 14 antimicrobials. Cation-adjusted Mueller-Hinton broth containing 2.5% laked horse blood was the preferred medium, with incubation in a microaerobic atmosphere of 10% CO2, 5% O2, and 85% N2 at 36°C for 48 h or 42°C for 24 h. PMID:16333113

  9. Design, synthesis and pharmacological screening of ?-amino-, thiadiazole/thiadiazine-phosphonate based triazole motifs as antimicrobial/cytotoxic agents.

    PubMed

    Abdou, Wafaa M; Ganoub, Neven A; Sabry, Eman

    2014-09-01

    Three different series of phosphonate derivatives, ?-amino- and fused thiadiazolo/thiadiazine-phosphonates have been synthesized using the addition and/or addition-cyclization protocol of Horner-Wadsworth-Emmons (HWE) reagents to 1,2,4-triazole-3-thiols. The design of potentially antimicrobial and anticancer phosphor esters relied on the results of computer-assisted molecular modeling. All synthesized phosphonates were evaluated for their in vitro antimicrobial activities while anticancer properties were determined for eight out of twenty new phosphonates. The tested phosphonates, except for compounds that have a nitrile moiety, exhibited moderate to significant antimicrobial activity. Nevertheless, the most active compounds were fused thiadiazole-phosphonates, which inhibited the growth of both Gram-negative and Gram-positive bacteria better than ?-aminophosphonates and fused thiadiazolophosphonates. In parallel, the antitumor activity screenings of selected phosphonates from each series and substrate 1 were also done. Their antitumor properties against ten carcinoma cell lines, including breast (MCF7, MDA-MB- 231/ ATCC, MDA-MB-435, BT-549), ovarian (IGROVI, OVCAR-3, SK-OV-3), prostate (PX-3, PU-145), and liver (HEPG2), were investigated. The results showed that all synthesized compounds reflected remarkable antitumor activity against breast (especially MDA-MB-231/ATCC and BT-549), and prostate carcinoma cell lines (PC-3 and DU-145), whereas a moderate to good effect on ovarian and liver cancer cells was observed. PMID:25296674

  10. In vitro antibacterial activity of medicinal plant extracts against Escherichia coli strains from human clinical specimens and interactions with antimicrobial drugs.

    PubMed

    Ushimaru, P I; Barbosa, L N; Fernandes, A A H; Di Stasi, L C; Fernandes, A

    2012-01-01

    The biological properties of medicinal plants have been documented worldwide for many centuries. We aimed to evaluate interactions between crude extracts from Psidium guajava, Zingiber officinale, Cymbopogon citratus, Caryophyllus aromaticus, Mikania glomerata and Allium sativum samples and antimicrobial drugs against Escherichia coli strains. The susceptibility test performed was disc diffusion, and crude extracts were diluted (%v/v) into Müller-Hinton agar (MHA) at one quarter of the minimal inhibitory concentration for 90% (MIC(90%)) of E. coli strains found previously. Synergistic interactions were observed between C. citratus and polymyxin, and A. sativum extracts and gentamicin. The crude A. sativum extract was the only one that did not show any antagonism with the antimicrobial drugs. The results thus showed the potential use of these medicinal plants against E. coli strains, although antagonism with antimicrobial drugs is a negative aspect in the combined therapy of infectious diseases caused by E. coli. PMID:22011190

  11. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Sept. 2003, p. 27252731 Vol. 47, No. 9 0066-4804/03/$08.00 0 DOI: 10.1128/AAC.47.9.27252731.2003

    E-print Network

    Trumpower, Bernard L.

    ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Sept. 2003, p. 2725­2731 Vol. 47, No. 9 0066 Resistance to Atovaquone in Pneumocystis jiroveci Philip Hill,1 Jacques Kessl,2 Nicholas Fisher,1 Steven resistance to atovaquone, a hydroxynaphthoquinone that is used to treat P. jiroveci infections, was linked

  12. Potential Antiosteoporotic Agents from Plants: A Comprehensive Review

    PubMed Central

    Jia, Min; Nie, Yan; Cao, Da-Peng; Xue, Yun-Yun; Wang, Jie-Si; Zhao, Lu; Rahman, Khalid; Zhang, Qiao-Yan; Qin, Lu-Ping

    2012-01-01

    Osteoporosis is a major health hazard and is a disease of old age; it is a silent epidemic affecting more than 200 million people worldwide in recent years. Based on a large number of chemical and pharmacological research many plants and their compounds have been shown to possess antiosteoporosis activity. This paper reviews the medicinal plants displaying antiosteoporosis properties including their origin, active constituents, and pharmacological data. The plants reported here are the ones which are commonly used in traditional medical systems and have demonstrated clinical effectiveness against osteoporosis. Although many plants have the potential to prevent and treat osteoporosis, so far, only a fraction of these plants have been thoroughly investigated for their physiological and pharmacological properties including their mechanism of action. An attempt should be made to highlight plant species with possible antiosteoporosis properties and they should be investigated further to help with future drug development for treating this disease. PMID:23365596

  13. Phytochemical screening and antimicrobial activities of plant extract of Lantana camara.

    PubMed

    Pradeep, B Vishwanath; Tejaswini, M; Nishal, P; Pardhu, G; Shylaja, S; Kumar, Kranthi Ch

    2013-05-01

    Natural products continue to play an important role in the discovery and development of new pharmaceuticals. Several chemical compounds have been extracted and identified from its species known as Lantana camara (L .camara). The present study was designed for phytochemical analysis of L. camara and extraction of bioactive compound by HPLC. This also included the antimicrobial activity of the bioactive compound obtained by crude extract and the column extract. The study showed the presence of the bioactive component parthenin extracted from the HPLC analysis at a peak height of 10.3807 and it was showing antimicrobial activity against E. coli, P. aeruginosa, B. subtilis and E. fecalis, crude (6.8 to 8.1 mm ) and column (4.0 to 6.2 mm) zone of inhibition. PMID:24617153

  14. Antimicrobial peptides

    PubMed Central

    2011-01-01

    Complicated schemes of classical breeding and their drawbacks, environmental risks imposed by agrochemicals, decrease of arable land, and coincident escalating damages of pests and pathogens have accentuated the necessity for highly efficient measures to improve crop protection. During co-evolution of host-microbe interactions, antimicrobial peptides (AMPs) have exhibited a brilliant history in protecting host organisms against devastation by invading pathogens. Since the 1980s, a plethora of AMPs has been isolated from and characterized in different organisms. Nevertheless the AMPs expressed in plants render them more resistant to diverse pathogens, a more orchestrated approach based on knowledge of their mechanisms of action and cellular targets, structural toxic principle, and possible impact on immune system of corresponding transgenic plants will considerably improve crop protection strategies against harmful plant diseases. This review outlines the current knowledge on different modes of action of AMPs and then argues the waves of AMPs' ectopic expression on transgenic plants' immune system. PMID:21847025

  15. Impact of wastewater from different sources on the prevalence of antimicrobial-resistant Escherichia coli in sewage treatment plants in South India.

    PubMed

    Akiba, Masato; Senba, Hironobu; Otagiri, Haruna; Prabhasankar, Valipparambil P; Taniyasu, Sachi; Yamashita, Nobuyoshi; Lee, Ken-Ichi; Yamamoto, Takehisa; Tsutsui, Toshiyuki; Ian Joshua, Derrick; Balakrishna, Keshava; Bairy, Indira; Iwata, Taketoshi; Kusumoto, Masahiro; Kannan, Kurunthachalam; Guruge, Keerthi S

    2015-05-01

    The sewage treatment plant (STP) is one of the most important interfaces between the human population and the aquatic environment, leading to contamination of the latter by antimicrobial-resistant bacteria. To identify factors affecting the prevalence of antimicrobial-resistant bacteria, water samples were collected from three different STPs in South India. STP1 exclusively treats sewage generated by a domestic population. STP2 predominantly treats sewage generated by a domestic population with a mix of hospital effluent. STP3 treats effluents generated exclusively by a hospital. The water samples were collected between three intermediate treatment steps including equalization, aeration, and clarification, in addition to the outlet to assess the removal rates of bacteria as the effluent passed through the treatment plant. The samples were collected in three different seasons to study the effect of seasonal variation. Escherichia coli isolated from the water samples were tested for susceptibility to 12 antimicrobials. The results of logistic regression analysis suggest that the hospital wastewater inflow significantly increased the prevalence of antimicrobial-resistant E. coli, whereas the treatment processes and sampling seasons did not affect the prevalence of these isolates. A bias in the genotype distribution of E. coli was observed among the isolates obtained from STP3. In conclusion, hospital wastewaters should be carefully treated to prevent the contamination of Indian environment with antimicrobial-resistant bacteria. PMID:25704279

  16. Evidence of VX nerve agent use from contaminated white mustard plants.

    PubMed

    Gravett, Matthew R; Hopkins, Farrha B; Self, Adam J; Webb, Andrew J; Timperley, Christopher M; Baker, Matthew J

    2014-08-01

    The Chemical Weapons Convention prohibits the development, production, acquisition, stockpiling, retention, transfer or use of chemical weapons by Member States. Verification of compliance and investigations into allegations of use require accurate detection of chemical warfare agents (CWAs) and their degradation products. Detection of CWAs such as organophosphorus nerve agents in the environment relies mainly upon the analysis of soil. We now present a method for the detection of the nerve agent VX and its hydrolysis products by gas chromatography and liquid chromatography mass spectrometry of ethanol extracts of contaminated white mustard plants (Sinapis alba) which retained the compounds of interest for up to 45 days. VX is hydrolysed by the plants to ethyl methylphosphonic acid and then to methylphosphonic acid. The utility of white mustard as a nerve agent detector and remediator of nerve agent-polluted sites is discussed. The work described will help deter the employment of VX in conflict. PMID:25104906

  17. Surveillance of susceptibility patterns in 1297 European and US anaerobic and capnophilic isolates to co-amoxiclav and five other antimicrobial agents.

    PubMed

    Koeth, Laura M; Good, Caryn E; Appelbaum, Peter C; Goldstein, Ellie J C; Rodloff, Arne C; Claros, Marina; Dubreuil, Luc J

    2004-06-01

    In vitro susceptibility data were collected for co-amoxiclav and other antimicrobial agents against 1297 recent anaerobe isolates collected in Europe and the USA. The co-amoxiclav (amoxicillin/clavulanic acid) MIC(50/90)s (amoxicillin/clavulanic acid concentration in a ratio of 2:1, expressed in terms of amoxicillin concentration in mg/L) were 0.5/4 for Bacteroides fragilis, antimicrobial treatment and prophylaxis of many anaerobic infections. Among the comparator drugs, metronidazole was very active against all bacterial species (>96% susceptible) except E. corrodens (MIC(50/90) of >32/>64 mg/L), which is a capnophilic organism. Imipenem was also highly active against all species (>98% susceptible). Levofloxacin and clindamycin were the least potent agents tested, particularly against Bacteroides, Prevotella and Peptostreptococcus (levofloxacin susceptibility rates: Bacteroides 72.7%, Prevotella 71.5%, F. magna 72.4%; clindamycin susceptibility rates: Bacteroides 79.5%, Prevotella 92.1%, F. magna 84.7%). PMID:15128729

  18. Ciprofloxacin: an oral quinolone for the treatment of infections with gram-negative pathogens. Committee on Antimicrobial Agents. Canadian Infectious Disease Society.

    PubMed Central

    Louie, T J

    1994-01-01

    OBJECTIVE: To optimize the use of ciprofloxacin, a synthetic fluoroquinolone, in community and hospital practice, and to minimize overprescribing by providing an overview of the literature and recommendations for appropriate use. OPTIONS: First-line treatment for infections in which ciprofloxacin is shown to be effective, treatment with oral ciprofloxacin rather than parenteral therapy with another drug, and step-down therapy with oral ciprofloxacin after initial parenteral treatment. OUTCOMES: In order of importance: efficacy, side effects and cost. EVIDENCE: A MEDLINE search of articles concerning ciprofloxacin, including in-vitro and pharmacokinetic studies using recognized standard methods with appropriate controls and published in recognized peer-reviewed journals, and randomized, controlled, double-blind clinical trials. VALUES: The Committee on Antimicrobial Agents of the Canadian Infectious Disease Society (CIDS) and a recognized expert (T.J.L.) recommended use of ciprofloxacin to treat infections against which it has proved effective both in vitro and in randomized controlled trials. They took into account its value as an oral replacement for other drugs given parenterally and development of resistance. BENEFITS, HARMS AND COSTS: With more appropriate use of ciprofloxacin there will be less development of resistant pathogens. For certain infections patients who would otherwise require admission to hospital could be treated at home and patients initially admitted for parenteral therapy could be discharged sooner on oral therapy with ciprofloxacin. RECOMMENDATIONS: Ciprofloxacin may be considered as first-line treatment for a number of infections in which gram-negative pathogens are proven or strongly suspected, including complicated urinary tract infections, bacterial prostatitis, bacterial diarrhea, selected bone and joint infections, malignant otitis externa, bronchopulmonary infections in patients with cystic fibrosis and selected pneumonia cases. VALIDATION: The paper was prepared, reviewed and revised by the Committee on Antimicrobial Agents of the CIDS. It was then reviewed and revised further by the Council of the CIDS. SPONSOR: The CIDS is solely responsible for developing, funding and endorsing these guidelines. PMID:8313286

  19. Antimicrobial Prophylaxis in Adults

    PubMed Central

    Enzler, Mark J.; Berbari, Elie; Osmon, Douglas R.

    2011-01-01

    Antimicrobial prophylaxis is commonly used by clinicians for the prevention of numerous infectious diseases, including herpes simplex infection, rheumatic fever, recurrent cellulitis, meningococcal disease, recurrent uncomplicated urinary tract infections in women, spontaneous bacterial peritonitis in patients with cirrhosis, influenza, infective endocarditis, pertussis, and acute necrotizing pancreatitis, as well as infections associated with open fractures, recent prosthetic joint placement, and bite wounds. Perioperative antimicrobial prophylaxis is recommended for various surgical procedures to prevent surgical site infections. Optimal antimicrobial agents for prophylaxis should be bactericidal, nontoxic, inexpensive, and active against the typical pathogens that can cause surgical site infection postoperatively. To maximize its effectiveness, intravenous perioperative prophylaxis should be administered within 30 to 60 minutes before the surgical incision. Antimicrobial prophylaxis should be of short duration to decrease toxicity and antimicrobial resistance and to reduce cost. PMID:21719623

  20. Sustainable bioproduction of phytochemicals by plant in vitro cultures: anticancer agents

    Microsoft Academic Search

    Michael Wink; A. Wilhelm Alfermann; Rochus Franke; Bernhard Wetterauer; Melanie Distl; Oliver Krohn; Elisabeth Fuss; Hermann Garden; Abdolali Mohagheghzadeh; Eckart Wildi; Peter Ripplinger

    2005-01-01

    Due to their complex structure with several chiral centres important anticancer agents are still extracted from plants and not synthesized chemically on a commercial scale. Sustainable biopro- duction of the compounds of interest may be achieved by plant in vitro cultures. Undifferen- tiated callus and suspension cultures, which can be cultivated in large bioreactors easily, very often fail to accumulate

  1. SOFTWARE AGENTS IN HANDLING ABNORMAL SITUATIONS IN INDUSTRIAL PLANTS

    E-print Network

    artificial intelligence to be implemented. 446-049 7 #12;2.2 BDI-model of practical reasoning BDI, for example, more flexibility than many other programming concepts and they fit well for complex situations: · Intelligence refers to agent's ability to make reasonable decisions based on its observations and internal

  2. EFFECT OF A FLYASH CONDITIONING AGENT ON POWER PLANT EMISSIONS

    EPA Science Inventory

    The report gives results of a study undertaken as a preliminary program to provide data on the environmental effects of a chemical flyash conditioning agent (Apollo Chemicals conditioner LPA 402A). Both the emissions due to the chemical and its effect on electrostatic precipitato...

  3. Frequency of resistance to methicillin and other antimicrobial agents among Staphylococcus aureus strains isolated from pigs and their human handlers in Trinidad

    PubMed Central

    Gordon, Annika; Marshall, Jennelle; Ramdass, Kris; Stewart-Johnson, Alva; Adesiyun, Abiodun

    2014-01-01

    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 implications. Finally, the diagnostic limitation of using CHROMagar and testing for oxacillin resistance by the disc diffusion method alone to determine MRSA strains without performing confirmatory tests cannot be overemphasized because the possibility of overdiagnosis of MRSA infections cannot be ignored. PMID:24765251

  4. Alternative Antimicrobial Approach: Nano-Antimicrobial Materials

    PubMed Central

    Beyth, Nurit; Houri-Haddad, Yael; Domb, Avi; Khan, Wahid; Hazan, Ronen

    2015-01-01

    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.

  5. Induction of Defense Responses in Cucumber Plants (Cucumis sativus L.) by the Biocontrol Agent Trichoderma harzianum

    Microsoft Academic Search

    I. YEDIDIA; N. BENHAMOU; I. CHET

    1999-01-01

    The potential of the biocontrol agent Trichoderma harzianum T-203 to trigger plant defense responses was investigated by inoculating roots of cucumber seedlings with Trichoderma in an aseptic, hydroponic system. Trichoderma-treated plants were more developed than nontreated plants throughout the experiment. Electron microscopy of ultrathin sections from Trichoderma-treated roots revealed penetration of Trichoderma into the roots, restricted mainly to the epidermis

  6. From individual to collective immunity: the role of the venom as antimicrobial agent in the Stenogastrinae wasp societies.

    PubMed

    Baracchi, David; Mazza, Giuseppe; Turillazzi, Stefano

    2012-01-01

    Sociality is associated with an increased risk of disease transmission and one of the first defense of the insect colonies is represented by antimicrobial secretions. In many eusocial hymenopteran species venom glands represent one of the most important source of antimicrobial substances. It is known that in highly eusocial species the venom is spread on both the cuticle of insects and the comb, thus becoming a component of the so called "social immunity". So far, it is never been ascertained whether this phenomenon is also present in more primitively eusocial and incipiently eusocial groups. Using incipiently eusocial hover wasps as model, we demonstrate that venom is present on insect cuticles and that it strongly acts against microorganisms. By contrast, the nest, regardless of materials, does not represent a ''medium" where the venom is deposited by wasps in order to act as a social antiseptic weapon. Our findings discussed in an evolutionary perspective indicate that a certain degree of sociality or a sufficient number of individuals in an insect society are thresholds to be reached for the rise of complex and efficient forms of collective and social immunity as mechanisms of resistance to diseases. PMID:22108024

  7. Antibiotic Conjugated Fluorescent Carbon Dots as a Theranostic Agent for Controlled Drug Release, Bioimaging, and Enhanced Antimicrobial Activity

    PubMed Central

    Patil, Vaibhav; Khade, Monika; Goshi, Ekta; Sharon, Madhuri

    2014-01-01

    A novel report on microwave assisted synthesis of bright carbon dots (C-dots) using gum arabic (GA) and its use as molecular vehicle to ferry ciprofloxacin hydrochloride, a broad spectrum antibiotic, is reported in the present work. Density gradient centrifugation (DGC) was used to separate different types of C-dots. After careful analysis of the fractions obtained after centrifugation, ciprofloxacin was attached to synthesize ciprofloxacin conjugated with C-dots (Cipro@C-dots conjugate). Release of ciprofloxacin was found to be extremely regulated under physiological conditions. Cipro@C-dots were found to be biocompatible on Vero cells as compared to free ciprofloxacin (1.2?mM) even at very high concentrations. Bare C-dots (?13?mg?mL?1) were used for microbial imaging of the simplest eukaryotic model—Saccharomyces cerevisiae (yeast). Bright green fluorescent was obtained when live imaging was performed to view yeast cells under fluorescent microscope suggesting C-dots incorporation inside the cells. Cipro@C-dots conjugate also showed enhanced antimicrobial activity against both model gram positive and gram negative microorganisms. Thus, the Cipro@C-dots conjugate paves not only a way for bioimaging but also an efficient new nanocarrier for controlled drug release with high antimicrobial activity, thereby serving potential tool for theranostics. PMID:24744921

  8. Antimicrobial activity of an Amazon medicinal plant (Chancapiedra) (Phyllanthus niruri L.) against Helicobacter pylori and lactic acid bacteria.

    PubMed

    Ranilla, Lena Gálvez; Apostolidis, Emmanouil; Shetty, Kalidas

    2012-06-01

    The potential of water extracts of the Amazon medicinal plant Chancapiedra (Phyllanthus niruri L.) from Ecuador and Peru for antimicrobial activity against Helicobacter pylori and different strains of lactic acid bacteria such as Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum was investigated. H. pylori was inhibited by both water extracts in a dose dependent manner, whereas lactic acid bacterial growth was not affected. Both extracts contained ellagic acid and hydroxycinnamic acid derivatives and exhibited high free radical scavenging linked-antioxidant activities (89%). However, gallic acid was detected only in the Ecuadorian extract. Preliminary studies on the mode of action of Chancapiedra against H. pylori revealed that inhibition may not involve proline dehydrogenase-based oxidative phosphorylation inhibition associated with simple mono-phenolics and could involve ellagitannins or other non-phenolic compounds through a yet unknown mechanism. This study provides evidence about the potential of Chancapiedra for H. pylori inhibition without affecting beneficial lactic acid bacteria. PMID:22034238

  9. Water and antimicrobial agent permation of PU and PHEMA membranes in relation to their surface and bulk properties.

    PubMed

    Pulat, M; Abbaso?lu, U

    1995-04-01

    Four types of polyurethane (PU) and two types of 2-polyhydroxyethylmethacrylate (PHEMA) membranes were prepared by convenient methods. Surface properties, water and antibacterial agent permeabilities of PU membranes were investigated. Water permeability values were determined in the region of 2000 g/m2.24 h. The membranes were found to have sufficient permeability toward antibacterial agents of 1% Silver Sulfadiazine and Bacitracin 10,000 UI-Neomycin sulphate 100 mg ointment. PMID:9309505

  10. Isolation, Diversity, and Antimicrobial Activity of Rare Actinobacteria from Medicinal Plants of Tropical Rain Forests in Xishuangbanna, China? †

    PubMed Central

    Qin, Sheng; Li, Jie; Chen, Hua-Hong; Zhao, Guo-Zhen; Zhu, Wen-Yong; Jiang, Cheng-Lin; Xu, Li-Hua; Li, Wen-Jun

    2009-01-01

    Endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. Xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. However, little is known about the endophytic actinobacteria of this tropical area. In this work, we studied the diversity of actinobacteria isolated from medicinal plants collected from tropical rain forests in Xishuangbanna. By the use of different selective isolation media and methods, a total of 2,174 actinobacteria were isolated. Forty-six isolates were selected on the basis of their morphologies on different media and were further characterized by 16S rRNA gene sequencing. The results showed an unexpected level of diversity, with 32 different genera. To our knowledge, this is the first report describing the isolation of Saccharopolyspora, Dietzia, Blastococcus, Dactylosporangium, Promicromonospora, Oerskovia, Actinocorallia, and Jiangella species from endophytic environments. At least 19 isolates are considered novel taxa by our current research. In addition, all 46 isolates were tested for antimicrobial activity and were screened for the presence of genes encoding polyketide synthetases and nonribosomal peptide synthetases. The results confirm that the medicinal plants of Xishuangbanna represent an extremely rich reservoir for the isolation of a significant diversity of actinobacteria, including novel species, that are potential sources for the discovery of biologically active compounds. PMID:19648362

  11. In vitro antimicrobial activity of essential oils from aromatic plants against selected foodborne pathogens.

    PubMed

    Rota, C; Carramiñana, J J; Burillo, J; Herrera, A

    2004-06-01

    The purpose of this study was to examine the effectiveness of selected essential oils for the control of growth and survival of pathogenic microorganisms of significant importance in food hygiene and to determine whether the antimicrobial effect was due to the major compounds of the oils. MIC and MBC were determined by the tube dilution method. Essential oils from Thymus vulgaris from Spain and France, Salvia sclarea, Salvia officinalis, Salvia lavandulifolia, Lavandula latifolia, Lavandula angustifolia, three hybrids of Lavandula latifolia x Lavandula angustifolia (Lavandin 'Super', Lavandin 'Abrialis', and Lavandin 'Grosso'), Rosmarinus officinalis, Hissopus officinalis, and Satureja montana were evaluated. Inhibition ranged from the strong activity of Satureja montana and Thymus vulgaris (France) to no inhibition with Salvia sclarea and Hissopus officinalis for each of the test strains: Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli O157:H7, Yersinia enterocolitica, Shigella flexneri, Listeria monocytogenes serovar 4b, and Staphylococcus aureus. Because some of the essential oils were highly inhibitory in small quantities to selected pathogenic microorganisms, they may provide alternatives to conventional antimicrobial additives in foods. PMID:15222560

  12. Novel ethyl 1,5-disubstituted-1H-pyrazole-3-carboxylates as a new class of antimicrobial agents.

    PubMed

    Radwan, Awwad A; Ghorab, Mostafa M; Alsaid, Mansour S; Alanazi, Fares K

    2014-09-01

    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) (MIC(E.coli) = 0.038 ?mol mL?¹, MIC(P. aerug.) = 0.067 ?mol mL?¹) is nearly as active as ampicillin (MIC = 0.033 and 0.067 ?mol mL?¹), respectively. Ethyl 5-(4-bromo-2-chlorophenyl)-1-phenyl-1H-pyrazole-3-carboxylate (16) (MIC = 0.015 ?mol mL?¹) is more active than fluconazole (0.020 ?mol mL?¹) as a reference drug against C. parapsilosis. PMID:25296679

  13. Contrasting effects of two antimicrobial agents (triclosan and triclocarban) on biomineralisation of an organophosphate pesticide in soils.

    PubMed

    Kookana, R S; Ali, A; Smith, L; Arshad, M

    2014-07-01

    We examined the impact of triclosan (TCS) and triclocarban (TCC) antimicrobial compounds on the biomineralisation of glucose and cadusafos pesticide in three Australian soils. Mineralisations of radiolabelled ((14)C) compounds were measured over a period of up to 77 d in sterile and non-sterile soils treated with different concentrations of TCS and TCC (0-450 mg kg(-1)). The rates of mineralisation of cadusafos were found to decrease with increasing concentration of TCS in all soils, but varied with soil type. Soils treated with TCS at the highest concentration (270 mg kg(-1)) reduced cadusafos mineralisation by up to 58%. However, glucose mineralisation was not significantly affected by the presence of TCS. While TCS, significantly reduced the mineralisation of cadusafos (by 17%; p<0.05) even at the lowest studied concentration (30 mg kg(-1)), no significant effect of TCC was observed on cadusafos or glucose mineralisation even at the highest concentration used (450 mg kg(-1)). PMID:24461429

  14. Lipooligosaccharide Structure is an Important Determinant in the Resistance of Neisseria Gonorrhoeae to Antimicrobial Agents of Innate Host Defense.

    PubMed

    Balthazar, Jacqueline T; Gusa, Asiya; Martin, Larry E; Choudhury, Biswa; Carlson, Russell; Shafer, William M

    2011-01-01

    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 ?-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 ?-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 pathogenesis. PMID:21747781

  15. Occurrence of anabolic agents in plants and their importance.

    PubMed

    Lindner, H R

    1976-01-01

    More than 40 plant species have been shown to contain substances that are active in biological assays for estrogenic activity. Such substances may be constitutive metabolic products of a plant, or be formed adaptively in response to environmental factors, such as fungal attack (e.g. coumestrol synthesis in alfalfa infected with Pseudopeziza medicagensis); in other instances estrogens may arise from microbial attack on plant material during storage (e.g. zearalenone formation from corn by Fusarium spp.) Phyto-estrogens may reach man through direct consumption of fresh fruit, vegetables and processed plant products (e.g. administration of olive or cornoil can induce vaginal keratinization in post-menopausal women); or---more relevant to this Symposium---by consumption of carcasses and products from animals fed estrogen-containing forage. Important pasture and forage plants shown to contain phyto-oestrogens include Trifolium subterraneum L, notably the cultivars Dwalganup, Mt. Barker, Yarloop and Marrar, T. pratense (red clover), T. fragiferum L. (strawberry clover), T. alexandrinum (berseem clover), Medicago sativa (alfalfa or lucerne) and Soya hispida (soya beans). A beneficial anabolic action of the estrogens contained in these plants has been implied, but not unequivically established. More attention has been paid to their noxious effects on livestock. On affected T. subterraneum pasture, castrated male sheep showed lactation, squamous metaplasia of the bulbo-urethral glands and urethral stenosis; infertility, variously attributed to suppression of gonadotrophin release and ovulation; faulty ovum transport; premature regression of corpora lutea; irreversible cystic hyperplasia of endometrial glands on prolonged exposure; dystocia and prolapse of the uterus. Sporadic incidence of phyto-estrogen induced infertility in cattle has been reported, attended by ovarian cyst formation. Estrogenic activity in forage plants has been reported from Australia, New Zealand, India, Sweden, Great Britain, Germany, Denmark, Holland, Finland, Egypt and Israel. The clover constituents chiefly incriminated for these effects are glycosides of the isoflavone derivatives genistein and its 4'-methyl ether biochanin-A, daidzein and its 4'-methyl ether formononetin, and pratensein; coumestrol and its 3'- and 4'-methyl ethers account for the estrogenic activity of alfalfa. The isoflavone content of subterranean clover may reach 3 percent of its dry weight, and the coumestrol content of lucerne may exceed 100 mug/g. Coumestrol and genistein compete with 17beta-estradiol for binding sites on the uterine cytoplasmic receptor and induce macromolecular synthesis in the uterus, but fail to induce ovum implantation in ovariectomized, gestagen-maintained rats. Uterotrophic activity of coumestrol and genistein given parenterally to sheep is approximately 10(-3) and 10(-5) times that of stilboestrol, respectively. Biological activity of ingested phytoestrogens is modified by ruminal micro-organisms and hepatic metabolism... PMID:1066275

  16. Antimicrobial Peptides: Versatile Biological Properties

    PubMed Central

    Pushpanathan, Muthuirulan; Rajendhran, Jeyaprakash

    2013-01-01

    Antimicrobial peptides are diverse group of biologically active molecules with multidimensional properties. In recent past, a wide variety of AMPs with diverse structures have been reported from different sources such as plants, animals, mammals, and microorganisms. The presence of unusual amino acids and structural motifs in AMPs confers unique structural properties to the peptide that attribute for their specific mode of action. The ability of these active AMPs to act as multifunctional effector molecules such as signalling molecule, immune modulators, mitogen, antitumor, and contraceptive agent makes it an interesting candidate to study every aspect of their structural and biological properties for prophylactic and therapeutic applications. In addition, easy cloning and recombinant expression of AMPs in heterologous plant host systems provided a pipeline for production of disease resistant transgenic plants. Besides these properties, AMPs were also used as drug delivery vectors to deliver cell impermeable drugs to cell interior. The present review focuses on the diversity and broad spectrum antimicrobial activity of AMPs along with its multidimensional properties that could be exploited for the application of these bioactive peptides as a potential and promising drug candidate in pharmaceutical industries. PMID:23935642

  17. Genetic analysis of plant endophytic Pseudomonas putida BP25 and chemo-profiling of its antimicrobial volatile organic compounds.

    PubMed

    Sheoran, Neelam; Valiya Nadakkakath, Agisha; Munjal, Vibhuti; Kundu, Aditi; Subaharan, Kesavan; Venugopal, Vibina; Rajamma, Suseelabhai; Eapen, Santhosh J; Kumar, Aundy

    2015-04-01

    Black pepper associated bacterium BP25 was isolated from root endosphere of apparently healthy cultivar Panniyur-5 that protected black pepper against Phytophthora capsici and Radopholus similis - the major production constraints. The bacterium was characterized and mechanisms of its antagonistic action against major pathogens are elucidated. The polyphasic phenotypic analysis revealed its identity as Pseudomonas putida. Multi locus sequence typing revealed that the bacterium shared gene sequences with several other isolates representing diverse habitats. Tissue localization assays exploiting green fluorescence protein expression clearly indicated that PpBP25 endophytically colonized not only its host plant - black pepper, but also other distantly related plants such as ginger and arabidopsis. PpBP25 colonies could be enumerated from internal tissues of plants four weeks post inoculation indicated its stable establishment and persistence in the plant system. The bacterium inhibited broad range of pathogens such as Phytophthora capsici, Pythium myriotylum, Giberella moniliformis, Rhizoctonia solani, Athelia rolfsii, Colletotrichum gloeosporioides and plant parasitic nematode, Radopholus similis by its volatile substances. GC/MS based chemical profiling revealed presence of Heneicosane; Tetratetracontane; Pyrrolo [1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl); Tetracosyl heptafluorobutyrate; 1-3-Eicosene, (E)-; 1-Heneicosanol; Octadecyl trifluoroacetate and 1-Pentadecene in PpBP25 metabolite. Dynamic head space GC/MS analysis of airborne volatiles indicated the presence of aromatic compounds such as 1-Undecene;Disulfide dimethyl; Pyrazine, methyl-Pyrazine, 2,5-dimethyl-; Isoamyl alcohol; Pyrazine, methyl-; Dimethyl trisulfide, etc. The work paved way for profiling of broad spectrum antimicrobial VOCs in endophytic PpBP25 for crop protection. PMID:25801973

  18. Diversity of root associated microorganisms of selected medicinal plants and influence of rhizomicroorganisms on the antimicrobial property of Coriandrum sativum.

    PubMed

    Tamilarasi, S; Nanthakumar, K; Karthikeyan, K; Lakshmanaperumalsamy, P

    2008-01-01

    The total heterotrophic bacteria, actinomycetes and fungus were enumerated from the rhizosphere and non-rhizosphere soil of 50 selected locally available medicinal plants in and around Bharathiar University. In all the plants, population of microorganism were higher in the rhizosphere soil than in the non rhizosphere soil. Among the microorganisms, bacterial population was higher in number followed by fungus and actinomycetes. Of the medicinal plants, the maximum rhizosphere effect was observed in Annona squamosa and the minimum effect was seen in Eclipta alba and Cassia auriculata. Among the bacteria the dominant species was Bacillus followed by Pseudomonas, Enterobacter, Corynebacterium, Micrococcus and Serratia. The Streptomyces species was found to be dominant followed by Deuteromycetes and Frankia among the actinomycetes. Among the fungal isolates Rhizopus was found to be higher in number followed by Aspergillus, Penicillium, Mucor and Fusarium. About 70.96% of the bacterial isolates were found to be nitrate reducers and 90.60% of the bacteria solubilised phosphate. The rhizosphere bacterial isolates were also capable of hydrolyzing starch, cellulose, casein, urea and gelatin. The isolates of bacteria, actinomycetes and fungus were also able to produce phytohormone Indole-3-acetic acid (IAA). The maximum IAA production was recorded by Fusarium sp (5.8 mg/l). The rhizosphere bacterial isolates showed resistance to 14 commercially used antibiotics. In an attempt to check the influence of these plant growth promoting microorganisms on the antimicrobial property of Coriandrum sativum against Escherichia coli MTCC-443 and Aeromonas hydrophila MTCC-646, the results observed was not encouraging since the inoculants did not influence the antibacterial property. However extensive and in depth study is required to find out the influence of rhizomicroorganisms on the antibacterial property of medicinal plants. The other results clearly indicated that the rhizosphere microorganisms could be exploited for its innumerable properties and active metabolites. PMID:18831345

  19. Antimicrobial peptide inhibition of fungalysin proteases that target plant type 19 Family IV defense chitinases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal crops and other plants produce secreted seed chitinases that reduce pathogenic infection, most likely by targeting the fungal chitinous cell wall. We have shown that corn (Zea mays) produces three GH family 19, plant class IV chitinases, that help in protecting the plant against Fusarium and ...

  20. The phenotypic and genotypic characteristics of antibiotic resistance in Escherichia coli populations isolated from farm animals with different exposure to antimicrobial agents.

    PubMed

    Mazurek, Justyna; Pusz, Pawe?; Bok, Ewa; Stosik, Micha?; 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. PMID:24053020

  1. Alternatives to the use of antimicrobial agents in pig production: A multi-country expert-ranking of perceived effectiveness, feasibility and return on investment.

    PubMed

    Postma, Merel; Stärk, Katharina D C; Sjölund, Marie; Backhans, Annette; Beilage, Elisabeth Grosse; Lösken, Svenja; Belloc, Catherine; Collineau, Lucie; Iten, Denise; Visschers, Vivianne; Nielsen, Elisabeth O; Dewulf, Jeroen

    2015-03-01

    Nineteen alternatives to antimicrobial agents were ranked on perceived effectiveness, feasibility and return on investment (ROI) from 0 (not effective, not feasible, no ROI) to 10 (fully effective, completely feasible, maximum ROI) by 111 pig health experts from Belgium, Denmark, France, Germany, Sweden and Switzerland. The top 5 measures in terms of perceived effectiveness were (1) improved internal biosecurity, (2) improved external biosecurity, (3) improved climate/environmental conditions, (4) high health/Specific Pathogen Free/disease eradication and (5) increased vaccination. The top 5 measures in terms of perceived feasibility were (1) increased vaccination, (2) increased use of anti-inflammatory products, (3) improved water quality, (4) feed quality/optimization and (5) use of zinc/metals. The top 5 measures in terms of perceived ROI were (1) improved internal biosecurity, (2) zinc/metals, (3) diagnostics/action plan, (4) feed quality/optimization and (5) climate/environmental improvements. Univariate linear regression showed that veterinary practitioners rank internal biosecurity, vaccination, use of zinc/metals, feed quality optimization and climate/environmental on average highest, while researchers and professors focused more on increased use of diagnostics and action plans. Financial incentives/penalties ranked low in all countries. Belgian respondents ranked feed quality significantly lower compared to the German respondents while reduction of stocking density was ranked higher in Belgium compared to Denmark. Categorical Principal Component Analysis applied to the average ranking supported the finding that veterinary practitioners had a preference for more practical, common and already known alternatives. The results showed that improvements in biosecurity, increased use of vaccination, use of zinc/metals, feed quality improvement and regular diagnostic testing combined with a clear action plan were perceived to be the most promising alternatives to antimicrobials in industrial pig production based on combined effectiveness, feasibility and ROI. PMID:25650306

  2. Isolation, abundance and phylogenetic affiliation of endophytic actinomycetes associated with medicinal plants and screening for their in vitro antimicrobial biosynthetic potential

    PubMed Central

    Passari, Ajit K.; Mishra, Vineet K.; Saikia, Ratul; Gupta, Vijai K.; Singh, Bhim P.

    2015-01-01

    Microorganisms associated with medicinal plants are of interest as the producers of important bioactive compounds. To date, the diversity of culturable endophytic actinomycetes associated with medicinal plants is in its initial phase of exploration. In this study, 42 endophytic actinomycetes were isolated from different organs of seven selected medicinal plants. The highest number of isolates (n = 22, 52.3%) of actinomycetes was isolated from roots, followed by stems (n = 9, 21.4%), leaves (n = 6, 14.2%), flowers (n = 3, 7.1%), and petioles (n = 2, 4.7%). The genus Streptomyces was the most dominant among the isolates (66.6%) in both the locations (Dampa TRF and Phawngpuii NP, Mizoram, India). From a total of 42 isolates, 22 isolates were selected for further studies based on their ability to inhibit one of the tested human bacterial or fungal pathogen. Selected isolates were identified based on 16S rRNA gene analysis and subsequently the isolates were grouped to four different genera; Streptomyces, Brevibacterium, Microbacterium, and Leifsonia. Antibiotic sensitivity assay was performed to understand the responsible antimicrobials present in the isolates showing the antimicrobial activities and revealed that the isolates were mostly resistant to penicillin G and ampicillin. Further, antimicrobial properties and antibiotic sensitivity assay in combination with the results of amplification of biosynthetic genes polyketide synthase (PKS-I) and non-ribosomal peptide synthetase (NRPS) showed that the endophytic actinomycetes associated with the selected medicinal plants have broad-spectrum antimicrobial activity. This is the first report of the isolation of Brevibacterium sp., Microbacterium sp., and Leifsonia xyli from endophytic environments of medicinal plants, Mirabilis jalapa and Clerodendrum colebrookianum. Our results emphasize that endophytic actinomycetes associated with medicinal plants are an unexplored resource for the discovery of biologically active compounds.

  3. Uses of antimicrobial genes from microbial genome

    DOEpatents

    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.

  4. Chemicals as peak shaving agents in IGCC based power plants

    SciTech Connect

    Hansen, J.B.; Aasberg-Petersen, K.; Sigurdardottir, D.; Nielsen, H. [Haldor Topsoe A/S (Denmark)

    1998-12-31

    Coal gasification generates a very impure synthesis gas, which before use in gas turbines for Integrated Gasification Combined Cycle (IGCC) plants has to be cleaned thoroughly. The purification of such a gas may be done by hot gas cleaning to a level which allows the gas to be used for production of chemicals such as methanol or dimethyl ether (DME). Such a production may be attractive either for use of the substances as such in the chemical industry or as automotive fuels. Alternatively these fuels may also be used as gas turbine fuels for power production. In the latter case an interesting possibility exists in the form of chemical recuperation. Low grade heat is used in the catalytically based transformation of methanol or DME into hydrogen and carbon monoxide. The present paper deals with the hot gas cleaning processes and the catalytic processes involved in a power plant in which the produced methanol and/or DME is used for peak shaving purposes.

  5. Antimicrobial Stewardship

    PubMed Central

    Doron, Shira; Davidson, Lisa E.

    2011-01-01

    Antimicrobial resistance is increasing; however, antimicrobial drug development is slowing. Now more than ever before, antimicrobial stewardship is of the utmost importance as a way to optimize the use of antimicrobials to prevent the development of resistance and improve patient outcomes. This review describes the why, what, who, how, when, and where of antimicrobial stewardship. Techniques of stewardship are summarized, and a plan for implementation of a stewardship program is outlined. PMID:22033257

  6. Evaluation of linalool, a natural antimicrobial and insecticidal essential oil from basil: Effects on poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Linalool is a natural plant product used in perfumes, cosmetics, and flavoring agents. Linalool has proven antimicrobial and insect repellant properties which indicate it might be useful for control of enteropathogens or insect pests in poultry production. However, there are no published reports t...

  7. Editorial of the Special Issue Antimicrobial Polymers

    PubMed Central

    Piozzi, Antonella; Francolini, Iolanda

    2013-01-01

    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. PMID:24005863

  8. Biochemical analysis of a multifunctional cytochrome P450 (CYP51) enzyme required for synthesis of antimicrobial triterpenes in plants

    PubMed Central

    Geisler, Katrin; Hughes, Richard K.; Sainsbury, Frank; Lomonossoff, George P.; Rejzek, Martin; Fairhurst, Shirley; Olsen, Carl-Erik; Motawia, Mohammed Saddik; Melton, Rachel E.; Hemmings, Andrew M.; Bak, Søren; Osbourn, Anne

    2013-01-01

    Members of the cytochromes P450 superfamily (P450s) catalyze a huge variety of oxidation reactions in microbes and higher organisms. Most P450 families are highly divergent, but in contrast the cytochrome P450 14?-sterol demethylase (CYP51) family is one of the most ancient and conserved, catalyzing sterol 14?-demethylase reactions required for essential sterol synthesis across the fungal, animal, and plant kingdoms. Oats (Avena spp.) produce antimicrobial compounds, avenacins, that provide protection against disease. Avenacins are synthesized from the simple triterpene, ?-amyrin. Previously we identified a gene encoding a member of the CYP51 family of cytochromes P450, AsCyp51H10 (also known as Saponin-deficient 2, Sad2), that is required for avenacin synthesis in a forward screen for avenacin-deficient oat mutants. sad2 mutants accumulate ?-amyrin, suggesting that they are blocked early in the pathway. Here, using a transient plant expression system, we show that AsCYP51H10 is a multifunctional P450 capable of modifying both the C and D rings of the pentacyclic triterpene scaffold to give 12,13?-epoxy-3?,16?-dihydroxy-oleanane (12,13?-epoxy-16?-hydroxy-?-amyrin). Molecular modeling and docking experiments indicate that C16 hydroxylation is likely to precede C12,13 epoxidation. Our computational modeling, in combination with analysis of a suite of sad2 mutants, provides insights into the unusual catalytic behavior of AsCYP51H10 and its active site mutants. Fungal bioassays show that the C12,13 epoxy group is an important determinant of antifungal activity. Accordingly, the oat AsCYP51H10 enzyme has been recruited from primary metabolism and has acquired a different function compared to other characterized members of the plant CYP51 family—as a multifunctional stereo- and regio-specific hydroxylase in plant specialized metabolism. PMID:23940321

  9. Improvement of water treatment pilot plant with Moringa oleifera extract as flocculant agent

    Microsoft Academic Search

    2009-01-01

    Moringa oleifera extract is a high?capacity flocculant agent for turbidity removal in surface water treatment. A complete study of a pilot?plant installation has been carried out. Because of flocculent sedimentability of treated water, a residual turbidity occured in the pilot plant (around 30 NTU), which could not be reduced just by a coagulation?flocculation?sedimentation process. Because of this limitation, the pilot

  10. Quinones derived from plant secondary metabolites as anti-cancer agents.

    PubMed

    Lu, Jin-Jian; Bao, Jiao-Lin; Wu, Guo-Sheng; Xu, Wen-Shan; Huang, Ming-Qing; Chen, Xiu-Ping; Wang, Yi-Tao

    2013-03-01

    Quinones are plant-derived secondary metabolites that present some anti-proliferation and anti-metastasis effects in various cancer types both in vitro and in vivo. This review focuses on the anti-cancer prospects of plant-derived quinones, namely, aloe-emodin, juglone, ?-lapachol, plumbagin, shikonin, and thymoquinone. We intend to summarize their anti-cancer effects and investigate the mechanism of actions to promote the research and development of anti-cancer agents from quinones. PMID:22931417

  11. Identification of penicillinase producing Neisseria gonorrhoeae in Chile during clinical and microbiological study of gonococcal susceptibility to antimicrobial agents.

    PubMed Central

    Garcia Moreno, J; Dillon, J R; Arroyave, R; Maldonado, A; Fich, F; Salvo, A; Villalobos, D; Vincent, P; Pauze, M

    1987-01-01

    The first penicillinase producing isolates of Neisseria gonorrhoeae (PPNG) identified in Chile were discovered during a clinical and microbiological study to compare the efficacy of penicillin (4.8 MIU aqueous procaine penicillin G plus 1 g oral probenecid) and tetracycline (1.5 g followed by 500 mg four times daily for four days) treatment regimens for acute uncomplicated gonorrhoea. Penicillin treatment was effective in 93.1% (282) of 303 patients, whereas tetracycline was effective in 98.3% (233) of 237 patients. Six of the penicillin treatment failures were attributable to PPNG strains. In all, 21 PPNG strains were identified during the study. They were genetically identical, having a wild type auxotype, a WII/III serotype (serovar Bajk), and carrying cryptic and transfer plasmids and an Asian type penicillinase producing plasmid. In addition, 674 non-PPNG isolates were tested for their susceptibility to eight antimicrobials. Over 95% were sensitivie to 1 mg/l of penicillin, ampicillin, cefotaxime, cefuroxime, and erythromycin, over 90% were sensitive to 1 mg/l of tetracycline and 2 mg/l of thiamphenicol, and all were sensitive to spectinomycin. Of 226 non-PPNG isolates characterised for plasmid content and auxotype, 90% (205) were either wild type or proline requiring, 67% (153) carried only the cryptic plasmid, and a further 31% (71) carried both cryptic and transfer plasmids. Unusually, three of four isolates lacking the cryptic plasmid carried only the transfer plasmid. Images PMID:3102348

  12. [Effects of plant polysaccharide compound agents on the photosynthetic characteristics and dry matter of soybean].

    PubMed

    Bai, Wen-Bo; Song, Ji-Qing; Guo, Jin-Yi; Liu, Xing-Hai; Li, Ji-Hui

    2012-07-01

    A field experiment was conducted to study the effects of foliar spraying three compound agents [plant polysaccharides (P1), plant polysaccharides and 5-aminolevulinic acid (P2), and plant polysaccharides and 5-aminolevulinic acid and dimethylpiperidinium chloride (P3)] at the initial flowering stage of soybean on its leaf chlorophyll content, photosynthesis and transpiration, dry matter accumulation and allocation, and grain yield. Within 35 days after spraying the three compound agents, the leaf chlorophyll content had obvious increase, and its decreasing trend with plant growth had somewhat delay. Compared with the control, spraying P1 and P3 increased the leaf photosynthetic rate and water use efficiency by more than 13.2% and 10.3%, respectively. With the spraying of the three compound agents, the dry matter accumulation in aerial part increased, and the allocation of dry matter from leaf to pod was also enhanced, with the contribution of post-anthesis assimilates to grain yield increased by more than 17.1%. The 100-grain mass and the pods and seeds per plant increased significantly after spraying P1 and P3, but had no significant increase after spraying P2. The grain yield of soybean treated with the three compound agents increased by more than 5.9%, compared with the control. This study showed that the three plant polysaccharide compound agents could increase the leaf chlorophyll content, delay the leaf-senescence, improve the leaf photosynthetic capacity and water status, effectively control the dry matter accumulation and post-anthesis assimilates allocation, and increase the grain yield of soybean. PMID:23173460

  13. Screening of hundred Rwandese medicinal plants for antimicrobial and antiviral properties

    Microsoft Academic Search

    A. J. Vlietinck; L. Van Hoof; J. Totté; A. Lasure; D. Vanden Berghe; P. C. Rwangabo; J. Mvukiyumwami

    1995-01-01

    A series of 100 Rwandese medicinal plants (267 plant extracts), used by traditional healers to treat infections, were screened for antibacterial, antifungal and antiviral properties. The results of the testing showed that 45% were active against Staphylococcus aureus, 2% against Escherichia coli, 16% against Pseudomonas aeruginosa, 7% against Candida albicans, 80% against Microsporum canis and 60% against Trichophyton mentagrophytes. Not

  14. [Measurement of chemical agents in metallurgy field: electric steel plant].

    PubMed

    Cottica, D; Grignani, E; Ghitti, R; Festa, D; Apostoli, P

    2012-01-01

    The steel industry maintains its important position in the context of the Italian production involving thousands of workers. The iron and steel processes are divided into primary steel industry, production of intermediate minerals, and secondary steel, scrap from the production of semi-finished industrial and consumer sector (metal inserted into components and metal used for dissipative uses, primarily coatings) and industrial waste. The paper presents the results of environmental monitoring carried out in some electric steel plant for the measurement of airborne chemicals that characterize the occupational exposure of workers employed in particular area like electric oven, to treatment outside the furnace, continuous casting area. For the sampling of the pollutants were used both personal and in fixed positions samplers. The pollutants measured are those typical of steel processes inhalable dust, metals, respirable dust, crystalline silica, but also Polycyclic Aromatic Hydrocarbons (PAH), polychlorinated dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). PMID:23213795

  15. In Vitro Susceptibilities of Naegleria fowleri Strain HB-1 to Selected Antimicrobial Agents, Singly and in Combination

    PubMed Central

    Lee, Kenneth K.; Karr, Stephen L.; Wong, Ming M.; Hoeprich, Paul D.

    1979-01-01

    The overall prognosis of primary amoebic meningoencephalitis remains poor. The results of this study support previous finding that amphotericin B is the most efficacious drug against the Naegleria species in in vitro testing. In addition, the methyl ester of amphotericin B, a new derivative, also appears to be an effective agent. Of the drug combinations studied, amphotericin B plus minocycline and amphotericin B plus tetracycline showed synergy. The clinical significance of these findings remains to be determined. PMID:485131

  16. Plant-mediated interactions: considerations for agent selection in weed biological control programs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-mediated indirect interactions among herbivores (arthropods and pathogens) are common and extensively reported in the ecological literature. However, they are not well-documented with respect to weed biological control. Such interactions between biological control agents can have net positive...

  17. 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

    Microsoft Academic Search

    Claudia Pileggi; Aida Bianco; Domenico Flotta; Carmelo GA Nobile; Maria Pavia

    2011-01-01

    Introduction  Given the high morbidity and mortality attributable to ventilator-associated pneumonia (VAP) in intensive care unit (ICU)\\u000a patients, prevention plays a key role in the management of patients undergoing mechanical ventilation. One of the candidate\\u000a preventive interventions is the selective decontamination of the digestive or respiratory tract (SDRD) by topical antiseptic\\u000a or antimicrobial agents. We performed a meta-analysis to investigate the

  18. Effect of mechanical damage on emission of volatile organic compounds from plant leaves and implications for evaluation of host plant specificity of prospective biological control agents of weeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Assessment of host plant specificity is a critical step in the evaluation of classical biological control agents of weeds, which is necessary for avoiding possible damage to nontarget plants. Volatile organic compounds (VOC) emitted by plants likely play an important role in determining which plant...

  19. Screening and Scoring of Antimicrobial and Biological Activities of Italian Vulnerary Plants against Major Oral Pathogenic Bacteria

    PubMed Central

    Ferrazzano, Gianmaria F.; Roberto, Lia; Catania, Maria Rosaria; Chiaviello, Angela; De Natale, Antonino; Roscetto, Emanuela; Pinto, Gabriele; Pollio, Antonino; Ingenito, Aniello; Palumbo, Giuseppe

    2013-01-01

    This study aims to evaluate the activity of Italian vulnerary plants against the most important oral pathogenic bacteria. This estimate was accomplished through a fivefold process: (a) a review of ethnobotanical and microbiological data concerning the Italian vulnerary plants; (b) the development of a scoring system to rank the plants; (c) the comparative assessment of microbiological properties; (d) the assessment of potential cytotoxic effects on keratinocyte-like cells and gingival fibroblasts in culture by XTT cell viability assay; (e) clinical evaluation of the most suitable plant extract as antibacterial agent in a home-made mouthwash. The study assays hexane (H), ethanol (E), and water (W) extracts from 72 plants. The agar diffusion method was used to evaluate the activity against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, and Actinomyces viscosus. Twenty-two plants showed appreciable activity. The extracts showing the strongest antibacterial power were those from Cotinus coggygria Scop., Equisetum hyemale L., Helichrysum litoreum Guss, Juniperus communis L., and Phyllitis scolopendrium (L.) Newman subsp. scolopendrium. The potential cytotoxic effect of these extracts was assessed. On the basis of these observations, a mouth-rinse containing the ethanolic extract of H. litoreum has been tested in vivo, resulting in reduction of the salivary concentration of S. mutans. PMID:24302963

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

    PubMed Central

    2014-01-01

    Background 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. Results 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 ?M), and greater inhibitory effect was observed at 40°C, a temperature similar to a high fever (IC50, 6.58?±?4.1 ?M). 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 ?M at 24, 48 and 72 h, respectively. Conclusions 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. PMID:24885331

  1. Waging War Against Extended Spectrum Beta Lactamase and Metallobetalactamase Producing Pathogens- Novel Adjuvant Antimicrobial Agent Cse1034- An Extended Hope

    PubMed Central

    Sanjith, S; Bhalekar, Pallavi; Keny, Dipti

    2014-01-01

    Preamble: In the visage of multidrug resistance among gram negative bacilli, we look forward to carbapenem group of drugs as empiric choice in seriously ill patients. However increasing resistance to carbapenems, the last resort, is of growing concern for all. It’s high time to look beyond Carbapenems and emphasize on Carbapenem sparers. Objective: This study is to find the susceptibility pattern of the novel adjuvant antimicrobial CSE 1034 a combination of Ceftriaxone+sulbactam+disodium edetate for the current ESBL and MBL isolates in a tertiary care centre. Materials and Methods: A total of 823 gram negative bacterial isolates were obtained from different clinical specimens during the period of March, 2013 to October, 2013. The overall prevalence of metallobetalactamase producing gram negative organisms was 11 percent (n=91). We included a total of 141 clinical isolates for this study. Results: Among 141 clinical isolates, 50 isolates (35%) were ESBL producers and 91 (65%) were MBL producers. Maximum numbers of ESBL producers were identified in Escherichia coli followed by Klebsiella pneumoniae, Acinetobacter baumannii and Proteus spp. Maximum numbers of MBL producers were identified in Klebsiella pneumoniae followed by Pseudomonas aeruginosa. CSE 1034 (Ceftriaxone+sulbactam+disodium edetate) showed fairly good in-vitro susceptibility for these ESBL and MBL producing isolates. It exhibited 64 % to 100% susceptibility and 18% to 22% intermediate sensitivity to ESBL producing isolates and 42 % to 89 % susceptible and 10 % to 51 % intermediate response to MBL producing isolates. Conclusion: With increasing resistance to the commonly prescribed drugs used to treat infections caused by variety of gram negative organisms, Ceftriaxone+sulbactam+disodium edetate, a novel Antibiotic Adjuvant Entity (AAE) may be a promising option. PMID:25120981

  2. Expression of an Engineered Heterologous Antimicrobial Peptide in Potato Alters Plant Development and Mitigates Normal Abiotic and Biotic Responses

    PubMed Central

    Goyal, Ravinder K.; Hancock, Robert E. W.; Mattoo, Autar K.; Misra, Santosh

    2013-01-01

    Antimicrobial cationic peptides (AMPs) are ubiquitous small proteins used by living cells to defend against a wide spectrum of pathogens. Their amphipathic property helps their interaction with negatively charged cellular membrane of the pathogen causing cell lysis and death. AMPs also modulate signaling pathway(s) and cellular processes in animal models; however, little is known of cellular processes other than the pathogen-lysis phenomenon modulated by AMPs in plants. An engineered heterologous AMP, msrA3, expressed in potato was previously shown to cause resistance of the transgenic plants against selected fungal and bacterial pathogens. These lines together with the wild type were studied for growth habits, and for inducible defense responses during challenge with biotic (necrotroph Fusarium solani) and abiotic stressors (dark-induced senescence, wounding and temperature stress). msrA3-expression not only conferred protection against F. solani but also delayed development of floral buds and prolonged vegetative phase. Analysis of select gene transcript profiles showed that the transgenic potato plants were suppressed in the hypersensitive (HR) and reactive oxygen species (ROS) responses to both biotic and abiotic stressors. Also, the transgenic leaves accumulated lesser amounts of the defense hormone jasmonic acid upon wounding with only a slight change in salicylic acid as compared to the wild type. Thus, normal host defense responses to the pathogen and abiotic stressors were mitigated by msrA3 expression suggesting MSRA3 regulates a common step(s) of these response pathways. The stemming of the pathogen growth and mitigating stress response pathways likely contributes to resource reallocation for higher tuber yield. PMID:24147012

  3. Determining the ecological impacts of organic contaminants in biosolids using a high-throughput colorimetric denitrification assay: a case study with antimicrobial agents.

    PubMed

    Holzem, R M; Stapleton, H M; Gunsch, C K

    2014-02-01

    Land application accounts for ? 50% of wastewater solid disposal in the United States. Still, little is known regarding the ecological impacts of nonregulated contaminants found in biosolids. Because of the myriad of contaminants, there is a need for a rapid, high-throughput method to evaluate their ecotoxicity. Herein, we developed a novel assay that measures denitrification inhibition in a model denitrifier, Paracoccus denitrificans Pd1222. Two common (triclosan and triclocarban) and four emerging (2,4,5 trichlorophenol, 2-benzyl-4-chlorophenol, 2-chloro-4-phenylphenol, and bis(5-chloro-2-hydroxyphenyl)methane) antimicrobial agents found in biosolids were analyzed. Overall, the assay was reproducible and measured impacts on denitrification over 3 orders of magnitude exposure. The lowest observable adverse effect concentrations (LOAECs) were 1.04 ?M for triclosan, 3.17 ?M for triclocarban, 0.372 ?M for bis-(5-chloro-2-hydroxyphenyl)methane, 4.89 ?M for 2-chloro-4-phenyl phenol, 45.7 ?M for 2-benzyl-4-chorophenol, and 50.6 ?M for 2,4,5-trichlorophenol. Compared with gene expression and cell viability based methods, the denitrification assay was more sensitive and resulted in lower LOAECs. The increased sensitivity, low cost, and high-throughput adaptability make this method an attractive alternative for meeting the initial testing regulatory framework for the Federal Insecticide, Fungicide, and Rodenticide Act, and recommended for the Toxic Substances Control Act, in determining the ecotoxicity of biosolids-derived emerging contaminants. PMID:24410196

  4. Stacking of antimicrobial genes in potato transgenic plants confers increased resistance to bacterial and fungal pathogens.

    PubMed

    Rivero, Mercedes; Furman, Nicolás; Mencacci, Nicolás; Picca, Pablo; Toum, Laila; Lentz, Ezequiel; Bravo-Almonacid, Fernando; Mentaberry, Alejandro

    2012-01-20

    Solanum tuberosum plants were transformed with three genetic constructions expressing the Nicotiana tabacum AP24 osmotine, Phyllomedusa sauvagii dermaseptin and Gallus gallus lysozyme, and with a double-transgene construction expressing the AP24 and lysozyme sequences. Re-transformation of dermaseptin-transformed plants with the AP24/lysozyme construction allowed selection of plants simultaneously expressing the three transgenes. Potato lines expressing individual transgenes or double- and triple-transgene combinations were assayed for resistance to Erwinia carotovora using whole-plant and tuber infection assays. Resistance levels for both infection tests compared consistently for most potato lines and allowed selection of highly resistant phenotypes. Higher resistance levels were found in lines carrying the dermaseptin and lysozyme sequences, indicating that theses proteins are the major contributors to antibacterial activity. Similar results were obtained in tuber infection tests conducted with Streptomyces scabies. Plant lines showing the higher resistance to bacterial infections were challenged with Phytophthora infestans, Rhizoctonia solani and Fusarium solani. Considerable levels of resistance to each of these pathogens were evidenced employing semi-quantitative tests based in detached-leaf inoculation, fungal growth inhibition and in vitro plant inoculation. On the basis of these results, we propose that stacking of these transgenes is a promising approach to achieve resistance to both bacterial and fungal pathogens. PMID:22115953

  5. In Vitro Evaluation of Antimicrobial Activity of Crude Extract from Plants Diospyros peregrina, Coccinia grandis and Swietenia macrophylla

    Microsoft Academic Search

    S Dewanjee; M Kundu; A Maiti; R Majumdar; A Majumdar

    Purpose: The aim of the present study was to investigate antimicrobial activity of methanol extract of Diospyros peregrina fruits (MEDP), Coccinia grandis leaves (MECG) and Swietenia macrophylla barks (MESM). Methods: MEDP, MECG and MESM were examined against some selective gram positive and gram negative bacterial (20) and fungal (4) strains. Preliminary antimicrobial activity was evaluated by agar disc diffusion method.

  6. In vitro antimicrobial activity of crude extracts from plants Bryophyllum pinnatum and Kalanchoe crenata.

    PubMed

    Akinsulire, Odunayo R; Aibinu, Ibukun E; Adenipekun, Tayo; Adelowotan, Toyin; Odugbemi, Tolu

    2007-01-01

    Extracts from the leaves of Bryophyllum pinnatum and Kalanchoe crenata were screened for their antimicrobial activities. Solvents used included water, methanol, and local solvents such as palmwine, local gin (Seaman's Schnapps 40% alcoholic drink,) and "omi ekan-ogi" (Sour water from 3 days fermented milled maize). Leaves were dried and powdered before being soaked in solvents for 3 days. Another traditional method of extraction by squeezing raw juice from the leaves was also employed. All extracts were lyophilized. These extracts were tested against some gram-negative organisms (Escherichia coli ATCC 25922, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Shigella flexneri, Salmonella paratyphi, Citrobacter spp); gram-positive organisms Staphylococcus aureus ATCC 25213, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis) and a fungus (Candida albicans). Agar well diffusion and broth dilution methods were used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at concentrations of 512 mg/ml to 4 mg/ml. All the organisms except Candida albicans were susceptible to the extracts obtained from the traditional method. The squeezed-leaf juice of Kalanchoe crenata was the most active one with MIC of 8 mg/ml against Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus subtilis, 32 mg/ml against Shigella flexneri, 64 mg/ml against Escherichia coli and 128 mg/ml against the control strain Staphylococcus aureus while its MBC is 256 mg/ml against these organisms except Bacillus subtilis and Klebsiella pneumoniae. The gram-positive organisms were more sensitive to the methanol and local gin-extract of Bryophyllum pinnatum. Extracts from other solvents showed moderate to weak activity. PMID:20161897

  7. Biological screening of some Turkish medicinal plant extracts for antimicrobial and toxicity activities.

    PubMed

    Turker, A U; Usta, C

    2008-01-20

    Screening of antibacterial activity and toxicity of 22 aqueous plant extracts from 17 Turkish plants was conducted. Antibacterial activity was performed with six bacteria including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Staphylococcus epidermidis. Extracts of Tussilago farfara leaves, Helichyrsum plicatum flowers, Solanum dulcamara aerial parts and Urtica dioica leaves gave the best inhibitory activity against S. pyogenes, S. aureus and S. epidermidis. Of the 22 plant extracts, 20 extracts displayed toxicity (LC50 was <1000 mg L(-1)) in the brine shrimp bioassay. For radish seed bioassay, two different determinations (root length and seed germination) were performed with a comparison between two concentrations (50,000 mg L(-1) and 10,000 mg L(-1)). At low concentration (10,000 mg L(-1)), S. dulcamara aerial parts and Primula vulgaris leaf extracts were observed to inhibit the root length more than the other plant extracts. Also, the most inhibitive plant extract for seed germination was obtained with S. dulcamara aerial parts. PMID:18075897

  8. Metabolomics Reveals the Origins of Antimicrobial Plant Resins Collected by Honey Bees

    E-print Network

    Weiblen, George D

    composition. Bees from our apiary discriminately foraged for resin from eastern cottonwood (Populus deltoides), and balsam poplar (P. balsamifera) among many available, even closely related, resinous plants. Cottonwood. Metabolomic analysis of resin from 6 North American Populus spp. and 5 hybrids revealed peaks characteristic

  9. Comparative antimicrobial activity of tannin extracts from perennial plants on mastitis pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three strains of pathogenic bacteria were treated with condensed tannins (CT) purified from eight different woody plant species to investigate their inhibition effect on the growth of these bacteria in vitro. Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were tested against low...

  10. Comparison of Essential Oils from Three Plants for Enhancement of Antimicrobial Activity of Nitrofurantoin against Enterobacteria

    Microsoft Academic Search

    Fatemeh Rafii; Ahmad R. Shahverdi

    2007-01-01

    Background: Piperitone from plant essential oils enhancesbactericidal activities of nitrofurantoin and furazolidone against bacteria from the family Enterobacteriaceae. In this study, the essential oils of spearmint (Mentha spicata L.), dill (Anethum graveolens L.) and peppermint (Mentha piperita L.)were screened for augmentation of nitrofurantoin activity and the most active components were determined. Method: The effects of essential oils and their components

  11. Global expression profile of biofilm resistance to antimicrobial compounds in the plant-pathogenic bacterium Xylella fastidiosa reveals evidence of persister cells.

    PubMed

    Muranaka, Lígia S; Takita, Marco A; Olivato, Jacqueline C; Kishi, Luciano T; de Souza, Alessandra A

    2012-09-01

    Investigations of biofilm resistance response rarely focus on plant-pathogenic bacteria. Since Xylella fastidiosa is a multihost plant-pathogenic bacterium that forms biofilm in the xylem, the behavior of its biofilm in response to antimicrobial compounds needs to be better investigated. We analyzed here the transcriptional profile of X. fastidiosa subsp. pauca in response to inhibitory and subinhibitory concentrations of copper and tetracycline. Copper-based products are routinely used to control citrus diseases in the field, while antibiotics are more widely used for bacterial control in mammals. The use of antimicrobial compounds triggers specific responses to each compound, such as biofilm formation and phage activity for copper. Common changes in expression responses comprise the repression of genes associated with metabolic functions and movement and the induction of toxin-antitoxin systems, which have been associated with the formation of persister cells. Our results also show that these cells were found in the population at a ca. 0.05% density under inhibitory conditions for both antimicrobial compounds and that pretreatment with subinhibitory concentration of copper increases this number. No previous report has detected the presence of these cells in X. fastidiosa population, suggesting that this could lead to a multidrug tolerance response in the biofilm under a stressed environment. This is a mechanism that has recently become the focus of studies on resistance of human-pathogenic bacteria to antibiotics and, based on our data, it seems to be more broadly applicable. PMID:22730126

  12. Antimicrobial Pesticides

    NSDL National Science Digital Library

    This newly launched site from the US Environmental Protection Agency (EPA) offers a variety of resources describing how the EPA regulates antimicrobial pesticides. Antimicrobial pesticides are used in a huge variety of household and commercial products to "disinfect, sanitize, reduce, or mitigate growth or development of microbiological organisms" and to "protect inanimate objects (for example floors and walls), industrial processes or systems, surfaces, water, or other chemical substances from contamination, fouling, or deterioration caused by bacteria, viruses, fungi, protozoa, algae, or slime." Intended mainly for a regulatory audience, the site includes Antimicrobials Science Policy Documents, Antimicrobials Registration Policy Documents, Label Review Manual, Chemical/ Registration Number Indexes, and Antimicrobial PR notices.

  13. Evaluation of Antimicrobial Activity of the Methanol Extracts from 8 Traditional Medicinal Plants

    PubMed Central

    Kang, Chang-Geun; Hah, Dae-Sik; Kim, Chung-Hui; Kim, Young-Hwan; Kim, Euikyung

    2011-01-01

    The methanol extract of 12 medicinal plants were evaluated for its antibacterial activity against Gram-positive (5 strains) and Gram-negative bacteria (10 strains) by assay for minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) . The antibacterial activity was determined by an agar dilution method (according to the guidelines of Clinical and Laboratory Standard Institute) . All the compounds (12 extracts) of the 8 medicinal plants (leaf or root) were active against both Gram-negative and Gram-positive bacteria. Gram-negative showed a more potent action than Gram positive bacteria. The MIC concentrations were various ranged from 0.6 ?g/ml to 5000 ?g/ml. The lowest MIC (0.6 ?g/ml) and MBC (1.22 ?g/ml) values were obtained with extract on 4 and 3 of the 15 microorganisms tested, respectively. PMID:24278548

  14. In vitro antimicrobial activity of plant-derived diterpenes against bovine mastitis bacteria.

    PubMed

    Fonseca, Ariana P; Estrela, Fernanda T; Moraes, Thaís S; Carneiro, Luiza J; Bastos, Jairo K; dos Santos, Raquel A; Ambrósio, Sérgio R; Martins, Carlos H G; Veneziani, Rodrigo C S

    2013-01-01

    We evaluated the antibacterial activity of three diterpenes isolated from natural sources against a panel of microorganisms responsible for bovine mastitis. ent-Copalic acid (CA) was the most active metabolite, with promising MIC values (from 1.56 to 6.25 µg mL-1) against Staphylococcus aureus (ATCC and clinical isolate), Staphylococcus epidermidis, Streptococcus agalactiae, and Streptococcus dysgalactiae. We conducted time-kill assays of CA against S. aureus, a commensal organism considered to be a ubiquitous etiological agent of bovine mastitis in dairy farms worldwide. In the first 12 h, CA only inhibited the growth of the inoculums (bacteriostatic effect), but its bactericidal effect was clearly noted thereafter (between 12 and 24 h). In conclusion, CA should be considered for the control of several Gram-positive bacteria related to bovine mastitis. PMID:23884123

  15. Terrestrial Plant-Derived Anticancer Agents and Plant Species Used in Anticancer Research

    Microsoft Academic Search

    Spiridon E. Kintzios

    2006-01-01

    Cancer is a major cause of death and the number of new cases, as well as the number of individuals living with cancer, is expanding continuously. Due to the enormous propensity of plants that synthesize mixtures of structurally diverse bioactive compounds, the plant kingdom is potentially a very diverse source of chemical constituents with tumor cytotoxic activity. Despite the successful

  16. Antimicrobial properties and phytochemical constituents of the leaves of African mistletoe (Tapinanthus dodoneifolius (DC) Danser) (Loranthaceae): an ethnomedicinal plant of Hausaland, Northern Nigeria.

    PubMed

    Deeni, Y Y; Sadiq, N M

    2002-12-01

    African mistletoe (Tapinanthus dodoneifolius (DC) Danser) called 'Kauchi' in Hausa is a hemi-plant parasite used ethnomedicinally by the Hausa and the Fulani tribes of Northern Nigeria as a remedy for several human and animal ailments that include stomach ache, diarrhoea, dysentery, wound and cancer. Screening of the plant, obtained from 14 different hosts, revealed a wide spectrum of antimicrobial activities against certain multiple drug resistant bacterial and fungal isolates of farm animals. Interestingly, the inhibition of the growth of Agrobacterium tumefaciens, Bacillus sp., Escherichia coli, Salmonella sp., Proteus sp. and Pseudomonas sp., bacterial sp. known to be associated with either crown gall or gastrointestinal tract and wound infections, by extracts of T. dodoneifolius gives credence to the ethnomedicinal usage of the plant. Phytochemical screening showed the common occurrence of anthraquinones, saponins, and tannins, a rare presence of alkaloids and the absence of phlobatannins in the hemi-parasite. Moreover, the antimicrobial activity and the presence or distribution of phytochemical substances in T. dodoneifolius appeared to be partly dependent on the host plant species. PMID:12426091

  17. Combinations of Biocontrol Agents for Management of Plant-Parasitic Nematodes and Soilborne Plant-Pathogenic Fungi

    PubMed Central

    Meyer, Susan L. F.; Roberts, Daniel P.

    2002-01-01

    Numerous microbes are antagonistic to plant-parasitic nematodes and soilborne plant-pathogenic fungi, but few of these organisms are commercially available for management of these pathogens. Inconsistent performance of applied biocontrol agents has proven to be a primary obstacle to the development of successful commercial products. One of the strategies for overcoming inconsistent performance is to combine the disease-suppressive activity of two (or more) beneficial microbes in a biocontrol preparation. Such combinations have potential for more extensive colonization of the rhizosphere, more consistent expression of beneficial traits under a broad range of soil conditions, and antagonism to a larger number of plant pests or pathogens than strains applied individually. Conversely, microbes applied in combination also may have antagonistic interactions with each other. Increased, decreased, and unaltered suppression of the target pathogen or pest has been observed when biocontrol microbes have been applied in combination. Unfortunately, the ecological basis for increased or decreased suppression has not been determined in many cases and needs further consideration. The complexity of interactions involved in the application of multiple organisms for biological control has slowed progress toward development of successful formulations. However, this approach has potential for overcoming some of the efficacy problems that occur with application of individual biocontrol agents. PMID:19265899

  18. In Vitro Antimicrobial Potential of the Lichen Parmotrema sp. Extracts against Various Pathogens

    PubMed Central

    Chauhan, Ritika; Abraham, Jayanthi

    2013-01-01

    Objective(s): The ongoing increasing antibiotic resistance is one of the biggest challenges faced by global public health. The perennial need for new antimicrobials against a background of increasing antibiotic resistance in pathogenic and opportunistic microorganisms obliges the scientific community to constantly develop new drugs and antimicrobial agents. Lichens are known prolific sources of natural antimicrobial drugs and biologically active natural products. This study was aimed to explore in vitro antimicrobial activity of lichen Parmotrema sp. Material and Methods: The methanol and aqueous extracts of lichen Parmotrema sp. was extracted using Soxhlet extractor. Antibiotic assessment of methanol and aqueous extracts was done against eight bacterial (Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Salmonella sp., Shigella sp., Enterococci faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae,) clinical pathogens and five plant pathogenic fungal strains (Aspergillus terreus strain JAS1, Scedosporium sp. JAS1, Ganoderma sp. JAS4, Candida tropicalis and Fusarium sp.) by Kirby-Bauer method. Results: The methanol lichen Parmotrema sp. extract inhibited all the test organisms. The highest antibacterial activity was found against Pseudomonas aeruginosa and Staphylococcus aureus. The weakest activity was manifested in Salmonella sp. and Scedosporium sp. JAS1. Strong antifungal effect was found against Ganoderma sp. JAS4 and Fusarium sp. The aqueous lichen Parmotrema sp. extract revealed neither antibacterial nor antifungal activity. Conclusion: The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens. PMID:23997920

  19. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Jan. 2011, p. 417420 Vol. 55, No. 1 0066-4804/11/$12.00 doi:10.1128/AAC.01080-10

    E-print Network

    Barron, Annelise E.

    and the polymyxin and echinocandin families of clinically approved antibiotics are an increasingly important class of antimicrobial peptides. Poly- myxin B (34) and trichogin (27) possess fatty acid moieties that are known

  20. Expression, purification and antimicrobial activity of puroindoline A protein and its mutants.

    PubMed

    Miao, Yingjie; Chen, Ling; Wang, Cheng; Wang, Yajuan; Zheng, Qian; Gao, Chunbao; Yang, Guangxiao; He, Guangyuan

    2012-10-01

    Wheat puroindoline proteins, PINA and PINB, play key roles in determining wheat grain hardness as well as in defending the plant against pathogens. PINA has much greater membrane-binding property and antimicrobial activity because it contains more tryptophan residues in the unique tryptophan-rich domain (TRD). In order to obtain proteins with higher antimicrobial activity, mutants of PINA containing two or three copies of TRD, designated ABBC and ABBBC, respectively, were constructed and expressed in E. coli Rosetta-gami (DE3). Metal affinity chromatography was used to purify the soluble affinity-tagged recombinant proteins. The secondary structures of the recombinant proteins were predicted by the online program Protein Homology/analog Y Recognition Engine v2.0 and experimentally assessed using circular dichroism. Minimum inhibition concentration tests and fluorescence microscope analyses were employed to evaluate the antimicrobial activities of the mutants. The results showed that the purified recombinant ABBC was correctly folded and presented significantly higher antimicrobial activities against E. coli and S. aureus than wild-type PINA, suggesting its potential use as an antimicrobial agent. The results also confirmed that TRD is a determinant of the antimicrobial activity of PINA and demonstrated that it is feasible to enhance the antimicrobial activity of PINA by adding one copy of TRD. PMID:22402594

  1. Antimicrobial peptides

    PubMed Central

    2014-01-01

    With increasing antibiotics resistance, there is an urgent need for novel infection therapeutics. Since antimicrobial peptides provide opportunities for this, identification and optimization of such peptides have attracted much interest during recent years. Here, a brief overview of antimicrobial peptides is provided, with focus placed on how selected hydrophobic modifications of antimicrobial peptides can be employed to combat also more demanding pathogens, including multi-resistant strains, without conferring unacceptable toxicity. PMID:24758244

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

    PubMed Central

    Liu, Fangwei; Anis, Reema; Hwang, Eunmi; Ovalle, Rafael; Varela-Ramírez, Armando; Aguilera, Renato J.; Contel, María

    2011-01-01

    New group 11 metal complexes have been prepared using the previously described tripodal bis(imidazole) thioether ligand (N-methyl-4,5-diphenyl-2-imidazolyl)2C(OMe)C(CH3)2S(tert-Bu) ({BITOMe,StBu}, 2). The pincer ligand offers a N2S donor atom set that can be used to coordinate the group 11 metals in different oxidation states [AuI, AuIII, AgI, CuI and CuII]. Thus the new compounds [Au{BITOMe,StBu}Cl][AuCl4]2 (3), [Au{BITOMe,StBu}Cl] (4), [Ag{BITOMe,StBu}X] (X = OSO2CF3 ? 5, PF6 ? 6) and [Cu{BITOMe,StBu}Cl2] (7) have been synthesized from reaction of 2 with the appropriate metal precursors, and characterized in solution. While attempting characterization in the solid state of 3, single crystals of the neutral dinuclear mixed AuIII-AuI species [Au2{BITOMe,S}Cl3] (8) were obtained and its crystal structure was determined by X-ray diffraction studies. The structure shows a AuIII center coordinated to the pincer ligand through one N and the S atom. The soft AuI center coordinates to the ligand through the same S atom that has lost the tert-butyl group, thus becoming a thiolate ligand. The short distance between the AuI–AuIII atoms (3.383 Å) may indicate a weak metal-metal interaction. Complexes 2–7 and the previously described CuI compound [Cu{BITOMe,StBu}]PF6 (9) have been evaluated in the oxidation of biphenyl ethylene with tert-butyl hydrogen peroxide (TBHP) as the oxidant. Results have shown that the AuI and AgI complexes 4 and 6 (at 10 mol % loading) are the more active catalysts in this oxidative cleavage. The antimicrobial activity of compounds 2–5, 7 and 9 against Gram-positive and Gram-negative bacteria and yeast has also been evaluated. The new gold and silver compounds display moderate to high antibacterial activity, while the copper derivatives are mostly inactive. The gold and silver complexes were also potent against fungi. Their cytotoxic properties have been analyzed in vitro utilizing HeLa human cervical carcinoma cells. The compounds displayed a 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. PMID:25134773

  3. Investigation of cream and ointment on antimicrobial activity of Mangifera indica extract

    PubMed Central

    Awad El-Gied, Amgad A.; Abdelkareem, Abdelkareem M.; Hamedelniel, Elnazeer I.

    2015-01-01

    Medicinal plants have curative properties due to the presence of various complex chemical substance of different composition, which are found as secondary plant metabolites in one or more parts of these plants. Mangifera indica Linn (MI L.) is a species of mango in the Anacardiaceae family. Phytoconstituents in the seed extracts may be responsible for the antimicrobial activity of the plant. The purpose of the study was to formulate and evaluate the antimicrobial herbal ointment and cream from extracts of the seeds of mango (MI L.) The formulated ointments containing oleaginous-based showed the best formulation compared to the emulsion water in oil type, the ointment and cream bases in different concentration 1%, 5% and 10%. The formulated ointment and cream of MI L. were subjected to evaluation of Uniformity of Weight, measurement of pH, viscosity, Spreadability, Acute skin irritation study, stability study and antimicrobial activity. Our study shows that MI has high potential as an antimicrobial agent when formulated as ointment and creams for topical use. Thus, the present study concludes that the formulated formulations of the MI are safe and efficient carriers, with potent antimicrobial activity.

  4. Plant-bacteria bioremediation agents affect the response of plant bioindicators independent of 2-chlorobenzoic acid degradation

    SciTech Connect

    Siciliano, S.D.; Germida, J.J. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada)

    1995-12-31

    Plants are known to degrade toxicants in soil and are potentially useful bioremediation agents. The authors developed plant-bacteria associations (e.g., Meadow brome [Bromus riparius] and Pseudomonas aeruginosa strain R75) that degrade 2-chlorobenzoic acid (2CBA) in soil, and assessed their success using Slender wheatgrass (Agropyron trachycaulum) germination as a bioindicator of 2CBA levels. Gas chromatography was used to chemically assess 2CBA levels. Specific plant-bacteria bioremediation treatments decreased soil 2CBA levels by 17 to 52%, but bioindicator response did not correspond to chemical analysis. Contaminated and uncontaminated soil was subjected to bioremediation treatments. After 42 days, uncontaminated soil was collected and amended to various 2CBA levels. This soil and the remediated soil were analyzed by the plant bioindicator and gas chromatography. Bioremediation treatments altered germination of Slender wheatgrass in both contaminated and noncontaminated soils to a similar extent. These treatments decreased the toxicity of 2CBA to Slender wheatgrass in both contaminated and noncontaminated soils to a similar extent. These treatments decreased the toxicity of 2CBA to Slender wheatgrass at low 2CBA levels, but increased the toxicity of 2CBA at high 2CBA levels. For example, germination in soil subjected to the Meadow brome and R75 treatment was increased by ca. 30% at 50 mg kg{sup {minus}1} 2CBA, but decreased by ca. 50% at 150 mg kg{sup {minus}1} 2CBA. The results indicate that specific plant-bacteria bioremediation treatments affect plant bioindicator response independent of 2CBA degradation, and may confound efforts to determine the toxicity of 2CBA in soil.

  5. Medicinal Plants Used as Antitumor Agents in Brazil: An Ethnobotanical Approach

    PubMed Central

    de Melo, Joabe Gomes; Santos, Ariane Gaspar; de Amorim, Elba Lúcia Cavalcanti; do Nascimento, Silene Carneiro; de Albuquerque, Ulysses Paulino

    2011-01-01

    We describe the medicinal plants that have been reported to be antitumor agents and that have been used in ethnobotanic research in Brazil to answer the following questions: what is the abundance of plants reported to be antitumor in Brazil? Have the plant species used for tumor treatment in traditional Brazilian medicine been sufficiently examined scientifically? Our analysis included papers published between 1980 and 2008. A total of 84 medicinal plant species were reported to be used for cancer and tumor prevention or treatment; 69.05% of these were cited as being used for the treatment of tumors and cancer in general and 30.95% for specific tumors or cancers. The plants that were cited at a higher frequency were Aloe vera, Euphorbia tirucalli, and Tabebuia impetiginosa. At least, one pharmacological study was found for 35.71% of the species. Majority of the studies selected were conducted in rural communities and urban areas and in areas with traditional healers in Brazil. We found the following molecules to be the most studied in vitro and in vivo: silibinin, ?-lapachone, plumbagin and capsaicin. The species addressed here constitute interesting objects for future studies to various professionals in the field of natural products. PMID:21528006

  6. Lepidopterans as Potential Agents for the Biological Control of the Invasive Plant, Miconia calvescens

    PubMed Central

    Morais, Elisangela G.F.; Picanço, Marcelo C.; Semeão, Altair A.; Barreto, Robert W.; Rosado, Jander F.; Martins, Julio C.

    2012-01-01

    This work investigated eight species of Lepidoptera associated with Miconia calvescens DC. (Myrtales: Melastomataceae) in Brazil, including six defoliators, Salbia lotanalis Druce (Lepidoptera: Pyralidae), Druentia inscita Schaus (Mimallonidae), Antiblemma leucocyma Hampson (Noctuidae), three Limacodidae species, a fruit borer Carposina cardinata Meyrick (Carposinidae), and a damager of flowers Pleuroprucha rudimentaria Guenée (Geometridae). Based on host specificity and the damage caused to plants, S. lotanalis and D. inscita are the most promising species for biological control of M. calvescens. Furthermore, if C. cardinata and P. rudimentaria have host specificity in future tests, these caterpillars could also be considered as appropriate biocontrol agents. PMID:22938203

  7. Lepidopterans as potential agents for the biological control of the invasive plant, Miconia calvescens.

    PubMed

    Morais, Elisangela G F; Picanço, Marcelo C; Semeão, Altair A; Barreto, Robert W; Rosado, Jander F; Martins, Julio C

    2012-01-01

    This work investigated eight species of Lepidoptera associated with Miconia calvescens DC. (Myrtales: Melastomataceae) in Brazil, including six defoliators, Salbia lotanalis Druce (Lepidoptera: Pyralidae), Druentia inscita Schaus (Mimallonidae), Antiblemma leucocyma Hampson (Noctuidae), three Limacodidae species, a fruit borer Carposina cardinata Meyrick (Carposinidae), and a damager of flowers Pleuroprucha rudimentaria Guenée (Geometridae). Based on host specificity and the damage caused to plants, S. lotanalis and D. inscita are the most promising species for biological control of M. calvescens. Furthermore, if C. cardinata and P. rudimentaria have host specificity in future tests, these caterpillars could also be considered as appropriate biocontrol agents. PMID:22938203

  8. Early experience with combined use of two plant-based hemostatic agents.

    PubMed

    Matsushita, Tsutomu; Masuda, Shinsuke; Inoue, Tomoya

    2010-07-01

    Bleeding from anastomoses, which is more effectively controlled with topical hemostatic agents than with sutures, has been one of the major problems in cardiovascular surgery. We describe a novel hemostatic technique using microporous polysaccharide hemosphere (Arista; Medafor Inc, Minneapolis, MN) in conjunction with a patch of oxidized regenerated cellulose (Nu-Knit; Ethicon, Johnson & Johnson, Somerville, NJ). Both of them are plant-based products and eliminate the risk of animal-borne or human-borne contaminants and have bactericidal advantages. PMID:20609820

  9. Antimicrobial Agents Used on Textiles

    NSDL National Science Digital Library

    The featured molecules of this month come from the article "Chemistry of Durable and Regenerable Biocidal Textiles" by Gang Sun and S. Dave Worley on the history and chemistry of biocidal textiles for use in the health care industry. All of these molecules can be bound to cellulose in a fabric through chemical modification, illustrating yet again the importance of such polymer-bound substrates in a wide-range of chemistries.

  10. Expression of an engineered heterologous antimicrobial peptide in potato alters plant development and mitigates normal abiotic and biotic responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial cationic peptides (AMPs) are ubiquitous small proteins used by living cells to defend against a wide spectrum of pathogens. Their amphipathic property helps their interaction with negatively charged cellular membrane of the pathogen causing cell lysis and death. AMPs also modulate sign...

  11. In-vitro antimicrobial activity screening of some ethnoveterinary medicinal plants traditionally used against mastitis, wound and gastrointestinal tract complication in Tigray Region, Ethiopia

    PubMed Central

    Kalayou, Shewit; Haileselassie, Mekonnen; Gebre-egziabher, Gebremedhin; Tiku'e, Tsegay; Sahle, Samson; Taddele, Habtamu; Ghezu, Mussie

    2012-01-01

    Objective To screen the antibacterial activity of nine ethnoveterinary plants traditionally used for the treatment of mastitis, wound and gastrointestinal complications. Methods Hydroalcoholic exctracts of medicinal plants namely, Achyranthes aspera (A. aspera) L. (Family Asparagaceae), Ficus caria (F. caria) (Family Moraceae), Malvi parviflora (M. parviflora) (Family Malvaceae), Vernonia species (V. species) (local name Alakit, Family Asteraceae), Solanum hastifolium (S. hastifolium) (Family Solanaceae), Calpurinia aurea (C. aurea) (Ait) Benth (Family Fabaceae), Nicotiana tabacum (N. tabacum) L. (Family Solanaceae), Ziziphus spina-christi (Z. spina-christi) (Family Rhamnaceae), Croton macrostachys (C. macrostachys) (Family Euphorbiaceae), were screened against clinical bacterial isolates of veterinary importance from October 2007 to April 2009. The antibacterial activity was tested using disc diffusion at two concentrations (200 mg/mL and 100 mg/mL) and broth dilution methods using 70% methanol macerated leaf extracts. Results With the exception of S. hastifolium all plant extracts exhibited antibacterial activity. Among the medicinal plants tested C. aurea, C. macrostachyus, A. aspera, N. tabacum and vernonia species (Alakit) showed the most promising antimicrobial properties. Conclusions It can be concluded that many of the tested plants have antibacterial activity and supports the traditional usage of the plants for mastitis, wound and gastrointestinal complications treatment. Further studies into their toxicity and phytochemistry is advocated. PMID:23569962

  12. Introduction: the goals of antimicrobial therapy

    Microsoft Academic Search

    Jac-Hoon Song

    2003-01-01

    Antimicrobial agents are generally evaluated in preclinical studies assessing in vitro activity, animal models demonstrating in vivo bacteriologic efficacy, and clinical trials primarily investigating safety and clinical efficacy. However, large sample sizes are required to detect any differences in outcomes between antimicrobials in clinical trials, and, generally, studies are powered to show only clinical equivalence. In addition, diagnosis is often

  13. Green synthesis of gold nanoparticles using plant extracts as reducing agents.

    PubMed

    Elia, Paz; Zach, Raya; Hazan, Sharon; Kolusheva, Sofiya; Porat, Ze'ev; Zeiri, Yehuda

    2014-01-01

    Gold nanoparticles (GNPs) were prepared using four different plant extracts as reducing and stabilizing agents. The extracts were obtained from the following plants: Salvia officinalis, Lippia citriodora, Pelargonium graveolens and Punica granatum. The size distributions of the GNPs were measured using three different methods: dynamic light scattering, nanoparticle-tracking analysis and analysis of scanning electron microscopy images. The three methods yielded similar size distributions. Biocompatibility was examined by correlation of L-cell growth in the presence of different amounts of GNPs. All GNPs showed good biocompatibility and good stability for over 3 weeks. Therefore, they can be used for imaging and drug-delivery applications in the human body. High-resolution transmission electron microscopy was used to view the shapes of the larger GNPs, while infrared spectroscopy was employed to characterize the various functional groups in the organic layer that stabilize the particles. Finally, active ingredients in the plant extract that might be involved in the formation of GNPs are proposed, based on experiments with pure antioxidants that are known to exist in that plant. PMID:25187704

  14. Green synthesis of gold nanoparticles using plant extracts as reducing agents

    PubMed Central

    Elia, Paz; Zach, Raya; Hazan, Sharon; Kolusheva, Sofiya; Porat, Ze’ev; Zeiri, Yehuda

    2014-01-01

    Gold nanoparticles (GNPs) were prepared using four different plant extracts as reducing and stabilizing agents. The extracts were obtained from the following plants: Salvia officinalis, Lippia citriodora, Pelargonium graveolens and Punica granatum. The size distributions of the GNPs were measured using three different methods: dynamic light scattering, nanoparticle-tracking analysis and analysis of scanning electron microscopy images. The three methods yielded similar size distributions. Biocompatibility was examined by correlation of L-cell growth in the presence of different amounts of GNPs. All GNPs showed good biocompatibility and good stability for over 3 weeks. Therefore, they can be used for imaging and drug-delivery applications in the human body. High-resolution transmission electron microscopy was used to view the shapes of the larger GNPs, while infrared spectroscopy was employed to characterize the various functional groups in the organic layer that stabilize the particles. Finally, active ingredients in the plant extract that might be involved in the formation of GNPs are proposed, based on experiments with pure antioxidants that are known to exist in that plant. PMID:25187704

  15. Antimicrobial contact lenses and lens cases: a review.

    PubMed

    Dutta, Debarun; Willcox, Mark D P

    2014-09-01

    Antimicrobial agents are being examined with the aim of developing antimicrobial contact lenses and new forms of antimicrobial lens cases. It is hoped that these developments will result in reduced contact lens-related microbial adverse events. In this review, we assess aspects of various antimicrobial strategies, such as cationic metals and peptides, selenium, quorum sensing inhibitors, and various biocidal and non-cidal agents. We highlight the historical challenges, the current scenario of this field, and recommendations for future antimicrobial strategies. PMID:25083781

  16. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Aug. 2011, p. 38613869 Vol. 55, No. 8 0066-4804/11/$12.00 doi:10.1128/AAC.00474-11

    E-print Network

    Strynadka, Natalie

    for tuberculosis (TB) are limited and notoriously ineffective despite the wide variety of potent antibiotics available antibiotics with limited efficacy against Mycobacterium tuberculosis might be used for TB. Among them, several families of antimicrobial compounds, including macrolides and azoles, were also

  17. Antimicrobial activity of spherical silver nanoparticles prepared using a biocompatible macromolecular capping agent: evidence for induction of a greatly prolonged bacterial lag phase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have evaluated the antimicrobial properties of Ag-based nanoparticles (Np) using two solid platform-based bioassays and found that 10-20 uL of 0.3-3 uM keratin-based Nps (depending on the starting bacteria concentration = CI) completely inhibited the growth of an equivalent volume of ca. 1,000 to...

  18. Antimicrobial Peptides Design by Evolutionary Multiobjective Optimization

    PubMed Central

    Maccari, Giuseppe; Di Luca, Mariagrazia; Nifosí, Riccardo; Cardarelli, Francesco; Signore, Giovanni; Boccardi, Claudia; Bifone, Angelo

    2013-01-01

    Antimicrobial peptides (AMPs) are an abundant and wide class of molecules produced by many tissues and cell types in a variety of mammals, plant and animal species. Linear alpha-helical antimicrobial peptides are among the most widespread membrane-disruptive AMPs in nature, representing a particularly successful structural arrangement in innate defense. Recently, AMPs have received increasing attention as potential therapeutic agents, owing to their broad activity spectrum and their reduced tendency to induce resistance. The introduction of non-natural amino acids will be a key requisite in order to contrast host resistance and increase compound's life. In this work, the possibility to design novel AMP sequences with non-natural amino acids was achieved through a flexible computational approach, based on chemophysical profiles of peptide sequences. Quantitative structure-activity relationship (QSAR) descriptors were employed to code each peptide and train two statistical models in order to account for structural and functional properties of alpha-helical amphipathic AMPs. These models were then used as fitness functions for a multi-objective evolutional algorithm, together with a set of constraints for the design of a series of candidate AMPs. Two ab-initio natural peptides were synthesized and experimentally validated for antimicrobial activity, together with a series of control peptides. Furthermore, a well-known Cecropin-Mellitin alpha helical antimicrobial hybrid (CM18) was optimized by shortening its amino acid sequence while maintaining its activity and a peptide with non-natural amino acids was designed and tested, demonstrating the higher activity achievable with artificial residues. PMID:24039565

  19. Antimicrobial properties of honey.

    PubMed

    Israili, Zafar H

    2014-01-01

    Honey has been widely accepted as food and medicine by all generations, traditions, and civilizations, both ancient and modern. For at least 2700 years, honey has been used by humans to treat a variety of ailments through topical application, but only recently have the antiseptic and antimicrobial properties of honey been discovered. Honey has been reported to be effective in a number of human pathologies. Clinical studies have demonstrated that application of honey to severely infected cutaneous wounds rapidly clears infection from the wound and improves tissue healing. A large number of in vitro and limited clinical studies have confirmed the broad-spectrum antimicrobial (antibacterial, antifungal, antiviral, and antimycobacterial) properties of honey, which may be attributed to the acidity (low pH), osmotic effect, high sugar concentration, presence of bacteriostatic and bactericidal factors (hydrogen peroxide, antioxidants, lysozyme, polyphenols, phenolic acids, flavonoids, methylglyoxal, and bee peptides), and increase in cytokine release, and to immune modulating and anti-inflammatory properties of honey; the antimicrobial action involves several mechanisms. Despite a large amount of data confirming the antimicrobial activity of honey, there are no studies that support the systemic use of honey as an antibacterial agent. PMID:23782759

  20. Antimicrobial, antioxidant, antitumour-promoting and cytotoxic activities of different plant part extracts of Garcinia atroviridis Griff. ex T. Anders

    Microsoft Academic Search

    M. M Mackeen; A. M Ali; N. H Lajis; K Kawazu; Z Hassan; M Amran; M Habsah; L. Y Mooi; S. M Mohamed

    2000-01-01

    Crude extracts (methanol) of various parts, viz. the leaves, fruits, roots, stem and trunk bark, of Garcinia atroviridis were screened for antimicrobial, cytotoxic, brine shrimp toxic, antitumour-promoting and antioxidant activities. The crude extracts exhibited predominantly antibacterial activity with the root extract showing the strongest inhibition against the test bacteria at a minimum inhibitory dose (MID) of 15.6 ?g\\/disc. Although all

  1. Occupational exposure to solid chemical agents in biomass-fired power plants and associated health effects.

    PubMed

    Jumpponen, M; Rönkkömäki, H; Pasanen, P; Laitinen, J

    2014-06-01

    Occupational exposure to aluminium, arsenic, lead, cadmium, and manganese can increase the risk of numerous neurophysiological changes in workers, and may lead to conditions resembling Parkinson's and Alzheimer's disease. However, although the health hazard aspect of these agents has been examined, biomass-fired power plant workers' exposure to them remains a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to inhalable dust, metals, and crystalline silica during their work tasks in biomass-fired power plants. Maintenance and ash removal workers were exposed to high inhalable dust concentrations inside biomass-fired boilers. The median air inhalable dust concentration in workers' breathing zones were 33 mg m(-3) and 120 mg m(-3) in ash removal and maintenance tasks, respectively. The median concentration of manganese (0.31 mg m(-3)) exceeded the occupational exposure limit in worker's breathing zone samples in maintenance tasks. The most evident exposure-associated health risk from multiple exposures to metals was that of cancer, followed by central nervous system disorders, lower respiratory tract irritation, and finally upper respiratory tract irritation. To avoid the above mentioned health effects, powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors are recommended as the minimum requirement for these work tasks. A compressed air breathing apparatus is the best form of protection for the most demanding work phases inside boilers in biomass-fired power plants. PMID:24289933

  2. Agent-Based Modleing of Power Plants Placement to Evaluate the Clean Energy Standard Goal

    SciTech Connect

    Omitaomu, Olufemi A [ORNL] [ORNL

    2014-01-01

    There is a political push for utilities to supply a specified share of their electricity sales from clean energy resources under the clean energy standard (CES). The goal is to achieve 80% clean energy by 2035. However, there are uncertainties about the ability of the utility industry to ramp up quickly even with the incentives that will be provided. Water availability from the streams is one of the major factors. The contiguous United States is divided into eighteen water regions, and multiple states share water from a single water region. Consequently, water usage decisions made in one state (located upstream of a water region that crosses multiple states) will greatly impact what is available downstream in another state. In this paper, an agent-based modeling approach is proposed to evaluate the clean energy standard goal for water-dependent energy resources. Specifically, using a water region rather than a state boundary as a bounding envelope for the modeling and starting at the headwaters, virtual power plants are placed based on the conditions that there is: (i) suitable land to site a particular power plant, (ii) enough water that meet regulatory guidelines within 20 miles of the suitable land, and (iii) a 20-mile buffer zone from an existing or a virtual power plant. The results obtained are discussed in the context of the proposed clean energy standard goal for states that overlap with one water region.

  3. Efficacy of plant-derived compounds combined with hydrogen peroxide as antimicrobial wash and coating treatment for reducing Listeria monocytogenes on cantaloupes.

    PubMed

    Upadhyay, Abhinav; Upadhyaya, Indu; Mooyottu, Shankumar; Kollanoor-Johny, Anup; Venkitanarayanan, Kumar

    2014-12-01

    The efficacy of four plant-derived antimicrobials (PDAs), namely carvacrol, thymol, ?-resorcylic acid, and caprylic acid, with or without hydrogen peroxide (HP), as antimicrobial wash and chitosan based coating for reducing Listeria monocytogenes (LM) on cantaloupes was investigated. Cantaloupe rind plugs inoculated with LM (10(7) CFU/cm(2)) were washed for 3, 6, 10 min at 25 °C or 1, 3, 5 min at 55 or 65 °C in water, or water containing 2% PDAs with or without 2% HP. Additionally, inoculated cantaloupes (10(8) CFU/fruit) washed with 2% PDA-HP combinations at 55 or 65 °C (5 min) were cut into rindless cubical pieces, stored at 4 °C for 7 days and sampled for LM. Furthermore, inoculated plugs coated with 2% PDAs were stored for 7 days and sampled for surviving LM. Individual PDA washes reduced LM on rinds by ?2.5 log CFU/cm(2) by 3 min (P < 0.05). PDA-HP combinations decreased LM to undetectable levels by 5 min at 55, 65 °C, and 10 min at 25 °C (P < 0.05) and reduced LM transfer from cantaloupe surface to interior (P < 0.0001). All PDA coating treatments reduced LM on cantaloupe to undetectable levels by 5 days (P < 0.05). Results indicate that PDAs alone, or with HP could be used to reduce LM on cantaloupes. PMID:25084644

  4. Antimicrobial resistance of fecal indicators in disinfected wastewater.

    PubMed

    Luczkiewicz, A; Jankowska, K; Bray, R; Kulbat, E; Quant, B; Sokolowska, A; Olanczuk-Neyman, K

    2011-01-01

    The main objective of the study was to assess the potential of three systems (UV irradiation, ozonation, and micro/ultrafiltration) operated in a pilot scale in removal of antimicrobial-resistant fecal bacteria from secondary effluent of the local wastewater treatment plant (700,000 population equivalent). The effectiveness of the processes was analysed using the removal ratio of fecal indicators (Escherichia coli and Enterococcus spp.). The susceptibility of fecal indicators to antimicrobial agents important in human therapy was examined. Resistance to nitrofurantoin and erythromycin was common among enterococci and followed by resistance to fluoroquinolones and tetracycline. Resistance to high-level aminoglycosides and glycopeptides was also observed. E. coli isolates were most frequently resistant to penicillins and tetracycline. The extended-spectrum beta-lactamase-producing E. coli was detected once, after ozonation. Substantial attention should be paid to the E. coli and enterococci resistant to three or more chemical classes of antimicrobials (MAR), which in general constituted up to 15 and 49% of the tested isolates, respectively. Although the applied methods were effective in elimination of fecal indicators (removal efficiency up to 99.99%), special attention has to be paid to the application of sufficient disinfection and operation conditions to avoid selection of antimicrobial resistant bacteria. PMID:22170827

  5. Antimicrobial peptides of multicellular organisms

    Microsoft Academic Search

    Michael Zasloff

    2002-01-01

    Multicellular organisms live, by and large, harmoniously with microbes. The cornea of the eye of an animal is almost always free of signs of infection. The insect flourishes without lymphocytes or antibodies. A plant seed germinates successfully in the midst of soil microbes. How is this accomplished? Both animals and plants possess potent, broad-spectrum antimicrobial peptides, which they use to

  6. Antimicrobial hydrogels for the treatment of infection

    PubMed Central

    Veiga, Ana Salomé; Schneider, Joel P.

    2014-01-01

    The increasing prevalence of microbial infections, especially those associated with impaired wound healing and biomedical implant failure has spurred the development of new materials having antimicrobial activity. Hydrogels are a class of highly hydrated material finding use in diverse medical applications such as drug delivery, tissue engineering, as wound fillers and as implant coatings, to name a few. The biocompatible nature of many gels make them a convenient starting platform to develop selectively active antimicrobial materials. Hydrogels with antimicrobial properties can be obtained through the encapsulation or covalent immobilization of known antimicrobial agents, or the material itself can be designed to possess inherent antimicrobial activity. In this review we present an overview of antimicrobial hydrogels that have recently been developed and when possible provide a discussion relevant to their mechanism of action. PMID:24122459

  7. Synthesis and biological screening of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyls as possible anti-tubercular and antimicrobial agents.

    PubMed

    Abhale, Yogita K; Sasane, Amit V; Chavan, Abhijit P; Deshmukh, Keshav K; Kotapalli, Sudha Sravanti; Ummanni, Ramesh; Sayyad, Sadikali F; Mhaske, Pravin C

    2015-04-13

    A series of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyl derivatives, 25-64 were synthesized and evaluated for inhibitory activity against Mycobacterium smegmatis MC(2) 155 strain and antimicrobial activities against four pathogenic bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Proteus vulgaris. Among them, compounds 40, 49, 50, and 54 exhibited moderate to good inhibition on the growth of the bacteria Mycobacterium smegmatis at the concentration of 30 ?M. Compounds 26, 40, 44, 54 and 56 exhibited moderate to good antibacterial activity. Compound 5-(2'-(4-fluorobenzyl)thiazol-4'-yl)-2-(4-fluorophenyl)-4-methyl-thiazole (54) exhibited both antitubercular as well as antimicrobial activity against all tested strains. PMID:25778990

  8. Preliminary studies towards utilization of various plant extracts as antisolar agents.

    PubMed

    Ramos, M F; Santos, E P; Bizarri, C H; Mattos, H A; Padilha, M R; Duarte, H M

    1996-06-01

    Synopsis The aim of this work was to evaluate several plant extracts with regard to ultraviolet absorption spectra in view of a possible application as antisolar agents. Liquid and dry extracts of Hamamelis virginiana, Matricaria recutita, Aesculus hippocastanum, Rhamnus purshiana and Cinnamomum zeylanicum were prepared by repercolation, maceration and microwave oven extraction. UVB absorption spectra (290-320nm) were obtained and the solar protection factors (SPF) of these preparations were determined by a spectrophotometric method. The results showed that after incorporation to a 2% solution of the synthetic sunscreen octylmethoxycinnamate, the extracts showed an intensification in SPF values, suggesting that this can be an interesting method to intensify SPF. In addition, these extracts can contribute their emollient and moistening properties to the product. These are important characteristics for protecting skin against exposure to the sun. PMID:19245460

  9. In-plant Validation of Two Antimicrobial Agents Applied During the Production of Tenderized and/or Enhanced Beef Products

    E-print Network

    Nelson, Kayla

    2013-08-28

    -associated bloody diarrhea and hemolytic uremic syndrome from hamburgers: the Washington experience. J. Am. Med. Assoc. 272:1349-1353. 6. Cabrera-Diaz, E., T. M. Moseley, L. M. Lucia, J. S. Dickson, A. Castillo, and G. R. Acuff. 2009. Fluorescent protein...-marked Escherichia coli Biotype I strains as surrogates for enteric pathogens in validation of beef carcass interventions. J. Food Prot. 72:295-303. 7. Castillo, A., L. M. Lucia, K. J. Goodson, J. W. Savell, and G. R. Acuff. 1998. Comparison of water wash...

  10. Antimicrobial activity of spherical silver nanoparticles prepared using a biocompatible macromolecular capping agent: evidence for induction of a greatly prolonged bacterial lag phase

    Microsoft Academic Search

    Peter Irwin; Justin Martin; Ly-Huong Nguyen; Yiping He; Andrew Gehring; Chin-Yi Chen

    2010-01-01

    BACKGROUND: We have evaluated the antimicrobial properties of Ag-based nanoparticles (Nps) using two solid phase bioassays and found that 10-20 ?L of 0.3-3 ?M keratin-stabilized Nps (depending on the starting bacterial concentration = CI) completely inhibited the growth of an equivalent volume of ca. 103 to 104 colony forming units per mL (CFU mL-1) Staphylococcus aureus, Salmonella Typhimurium, or Escherichia

  11. Organic extracts from Indigofera suffruticosa leaves have antimicrobial and synergic actions with erythromycin against Staphylococcus aureus

    PubMed Central

    Bezerra dos Santos, Ana Thereza; Araújo, Tiago Ferreira da Silva; Nascimento da Silva, Luis Cláudio; da Silva, Cleideana Bezerra; de Oliveira, Antonio Fernando Morais; Araújo, Janete Magali; Correia, Maria Tereza dos Santos; Lima, Vera Lúcia de Menezes

    2015-01-01

    A characteristic feature of Staphylococcus aureus is its ability to acquire resistance to antimicrobial agents. There is a need, therefore, for new approaches to combat this pathogen; for example, employing a combination of plant-derived products and antibiotics to overcome bacterial resistance. Indigofera suffruticosa is a plant popularly used to treat infections and has verified antimicrobial action. Here, we investigate the antimicrobial activity of different extracts from I. suffruticosa against S. aureus and their synergistic effects with erythromycin. Leaves of I. suffruticosa were extracted sequentially using diethyl ether, chloroform and acetone and the antimicrobial activity of each extract then tested against nine clinical isolates of S. aureus. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by microdilution tests, while the fractional inhibitory concentration (FIC) was assessed by checkerboard assay. All organic solvent extracts showed antimicrobial activity against S. aureus strains. The acetone extract was the most potent inhibitor of S. aureus (MIC and MBC of 0.78 and 3.12 mg/mL), followed by the chloroform extract (MIC and MBC of 3.12 and 6.25 mg/mL). Furthermore, acetone or chloroform extracts of I. suffruticosa enhanced the activity of erythromycin against S. aureus (FIC ? 0.5). We conclude that organic extracts from leaves of I. suffruticosa, alone or combined with erythromycin, are promising natural products for the development of new anti-S. aureus formulations. PMID:25699022

  12. Organic extracts from Indigofera suffruticosa leaves have antimicrobial and synergic actions with erythromycin against Staphylococcus aureus.

    PubMed

    Bezerra Dos Santos, Ana Thereza; Araújo, Tiago Ferreira da Silva; Nascimento da Silva, Luis Cláudio; da Silva, Cleideana Bezerra; de Oliveira, Antonio Fernando Morais; Araújo, Janete Magali; Correia, Maria Tereza Dos Santos; Lima, Vera Lúcia de Menezes

    2015-01-01

    A characteristic feature of Staphylococcus aureus is its ability to acquire resistance to antimicrobial agents. There is a need, therefore, for new approaches to combat this pathogen; for example, employing a combination of plant-derived products and antibiotics to overcome bacterial resistance. Indigofera suffruticosa is a plant popularly used to treat infections and has verified antimicrobial action. Here, we investigate the antimicrobial activity of different extracts from I. suffruticosa against S. aureus and their synergistic effects with erythromycin. Leaves of I. suffruticosa were extracted sequentially using diethyl ether, chloroform and acetone and the antimicrobial activity of each extract then tested against nine clinical isolates of S. aureus. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by microdilution tests, while the fractional inhibitory concentration (FIC) was assessed by checkerboard assay. All organic solvent extracts showed antimicrobial activity against S. aureus strains. The acetone extract was the most potent inhibitor of S. aureus (MIC and MBC of 0.78 and 3.12 mg/mL), followed by the chloroform extract (MIC and MBC of 3.12 and 6.25 mg/mL). Furthermore, acetone or chloroform extracts of I. suffruticosa enhanced the activity of erythromycin against S. aureus (FIC ? 0.5). We conclude that organic extracts from leaves of I. suffruticosa, alone or combined with erythromycin, are promising natural products for the development of new anti-S. aureus formulations. PMID:25699022

  13. Efflux-mediated antimicrobial resistance

    Microsoft Academic Search

    Keith Poole

    2005-01-01

    biocide resistance is as yet unrealized, in vitro and in vivo episodes of reduced biocide susceptibility are common and the history of antibiotic resistance should not be ignored in the development and use of biocidal agents. Efflux mechanisms of resistance, both drug specific and multidrug, are important deter- minants of intrinsic and\\/or acquired resistance to these antimicrobials, with some accommodating

  14. ALTERNATIVES TO ANTIMICROBIAL USE IN FOOD ANIMAL PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of antimicrobial agents in food animal production and its potential human health impact have captured the attention of scientists, animal producers, physicians, veterinarians, and consumers on a global level. Use of antimicrobial agents as a method to enhance animal performance or for disease pr...

  15. In vitro anti-microbial activity of the Cuban medicinal plants Simarouba glauca DC, Melaleuca leucadendron L and Artemisia absinthium L.

    PubMed

    Valdés, Aymé Fernández-Calienes; Martínez, Judith Mendiola; Lizama, Ramón Scull; Vermeersch, Marieke; Cos, Paul; Maes, Louis

    2008-09-01

    In the present study, an extensive in vitro antimicrobial profiling was performed for three medicinal plants grown in Cuba, namely Simarouba glauca, Melaleuca leucadendron and Artemisia absinthium. Ethanol extracts were tested for their antiprotozoal potential against Trypanosoma b. brucei, Trypanosoma cruzi, Leishmania infantum and Plasmodium falciparum. Antifungal activities were evaluated against Microsporum canis and Candida albicans whereas Escherichia coli and Staphylococcus aureus were used as test organisms for antibacterial activity. Cytotoxicity was assessed against human MRC-5 cells. Only M. leucadendron extract showed selective activity against microorganisms tested. Although S. glauca exhibited strong activity against all protozoa, it must be considered non-specific. The value of integrated evaluation of extracts with particular reference to selectivity is discussed. PMID:18949336

  16. Isolation and characterization of endophytic bacteria from Plectranthus tenuiflorus medicinal plant in Saudi Arabia desert and their antimicrobial activities

    Microsoft Academic Search

    Bahig El-Deeb; Khalaf Fayez; Youssuf Gherbawy

    2012-01-01

    The diversity and beneficial characteristics of endophytic microorganisms have been studied in Plectranthus tenuiflorus medicinal plant. However, information regarding naturally occurring P. tenuiflorus plant associated endophytes among different organs of host is limited. Endophytic bacteria were isolated from root, stem, and leaves of P. tenuiflorus plant. Among 28 endophytic bacterial isolates from different organs of P. tenuiflorus plant, 8 isolates

  17. Management of fluoroquinolone resistance in Pseudomonas aeruginosa—Outcome of monitored use in a referral hospital 1 Presented, in part, at the 33rd Interscience Conference on Antimicrobial Agents and Chemotherapy, New Orleans, LA, October 17–21, 1993. Abstract #234. 1

    Microsoft Academic Search

    L. R Peterson; M Postelnick; T. L Pozdol; B Reisberg; G. A Noskin

    1998-01-01

    We evaluated a strategy designed to improve useful activity of ciprofloxacin against Pseudomonas aeruginosa. Following changes in antimicrobial agent use made by the institutional Pharmacy and Therapeutic Drug Committee, monthly drug usage and microbial susceptibility records from June 1992 through October l995 were reviewed. From July 1992 through October 1992 (Period 1), ciprofloxacin and ofloxacin usage represented 95 and 5%

  18. Antimicrobial activities of endophytic fungi isolated from Ophiopogon japonicus (Liliaceae)

    PubMed Central

    2012-01-01

    Background Drug resistance in bacteria has become a global concern and the search for new antibacterial agents is urgent and ongoing. Endophytes provide an abundant reservoir of bioactive metabolites for medicinal exploitation, and an increasing number of novel compounds are being isolated from endophytic fungi. Ophiopogon japonicus, containing compounds with antibacterial activity, is a traditional Chinese medicinal plant used for eliminating phlegm, relieving coughs, latent heat in the lungs, and alleviating diabetes mellitus. We investigated the antimicrobial activities of 30 strains of O. japonicus. Methods Fungal endophytes were isolated from roots and stems of O. japonicus collected from Chongqing City, southwestern China. Mycelial extracts (MC) and fermentation broth (FB) were tested for antimicrobial activity using peptide deformylase (PDF) inhibition fluorescence assays and MTT cell proliferation assays. Results A total of 30 endophytic strains were isolated from O. japonicus; 22 from roots and eight from stems. 53.33% of the mycelial extracts (MC) and 33.33% of the fermentation broths (FB) displayed potent inhibition of PDF. 80% of MC and 33.33% of FB significantly inhibited Staphylococcus aureus. 70% of MC and 36.67% of FB showed strong activities against Cryptococcus neoformans. None showed influence on Escherichia coli. Conclusion The secondary metabolites of endophytic fungi from O. japonicus are potential antimicrobial agents. PMID:23190550

  19. Interaction of antimicrobial cyclic lipopeptides from Bacillus subtilis influences their effect on spore germination and membrane permeability in fungal plant pathogens.

    PubMed

    Liu, Jiajie; Hagberg, Ingrid; Novitsky, Laura; Hadj-Moussa, Hanane; Avis, Tyler J

    2014-11-01

    Bacillus subtilis cyclic lipopeptides are known to have various antimicrobial effects including different types of interactions with the cell membranes of plant pathogenic fungi. The various spectra of activities of the three main lipopeptide families (fengycins, iturins, and surfactins) seem to be linked to their respective mechanisms of action on the fungal biomembrane. Few studies have shown the combined effect of more than one family of lipopeptides on fungal plant pathogens. In an effort to understand the effect of producing multiple lipopeptide families, sensitivity and membrane permeability of spores from four fungal plant pathogens (Alternaria solani, Fusarium sambucinum, Rhizopus stolonifer, and Verticillium dahliae) were assayed in response to lipopeptides, both individually and as combined treatments. Results showed that inhibition of spores was highly variable depending on the tested fungus-lipopeptide treatment. Results also showed that inhibition of the spores was closely associated with SYTOX stain absorption suggesting effects of efficient treatments on membrane permeability. Combined lipopeptide treatments revealed additive, synergistic or sometimes mutual inhibition of beneficial effects. PMID:25442289

  20. Antimicrobial effects of selected plant essential oils on the growth of a Pseudomonas putida strain isolated from meat.

    PubMed

    Oussalah, Mounia; Caillet, Stéphane; Saucier, Linda; Lacroix, Monique

    2006-06-01

    The inhibitory effect of 60 different essential oils was evaluated on a Pseudomonas putida strain of meat origin, associated with meat spoilage. Essential oils were tested at concentrations from 0.003 to 0.8% (wt/vol) to determine minimum inhibitory and maximal tolerated concentrations (MIC and MTC, respectively) using an agar medium culture. Of the 60 samples tested, Corydothymus capitatus essential oil was the most active showing a MIC of 0.025% and a MTC of 0.06%. Seven essential oils (Cinnamomum cassia, Origanum compactum, Origanum heracleoticum, Satureja hortensis, Satureja montana, Thymus vulgaris carvacroliferum, Thymus vulgaris thymoliferum) have shown a strong antimicrobial activity against P. putida with a MIC of 0.05% and a MTC ranging from 0.013% to 0.025%. Ten other oils (Cinnamomum verum (leaf and bark), Eugenia caryophyllus, Cymbopogon martinii var. motia, Cymbopogon nardus, Melaleuca linariifolia, Origanum majorana, Pimenta dioica, Thymus satureoides, Thymus serpyllum) showed a high antimicrobial activity showing a MIC ranging from 0.1% to 0.4%, while the remaining were less active showing a MIC?0.8%. PMID:22062294

  1. Plant size preference of Agapeta zoegana L. (Lepidoptera: Tortricidae), a root-feeding biological control agent of spotted knapweed

    Microsoft Academic Search

    L. Smith; J. M. Story

    2003-01-01

    Agapeta zoegana L. (Lepidoptera: Tortricidae) is an oligophagous herbivore that was introduced to North America as a biological control agent of spotted knapweed, Centaurea stoebe L. subsp. micranthos (Gugler) Hayek (often called Centaurea maculosa Lam.). Spotted knapweed is a perennial plant that usually increases in size each year. A previous field study reported that more larvae were found on larger

  2. Effects of the Magnetic Resonance Imaging Contrast Agent Gd-DTPA on Plant Growth and Root Imaging in Rice

    PubMed Central

    Liu, Binmei; Wang, Qi; Ni, Xiaoyu; Dong, Yaling; Zhong, Kai; Wu, Yuejin

    2014-01-01

    Although paramagnetic contrast agents have a wide range of applications in medical studies involving magnetic resonance imaging (MRI), these agents are seldom used to enhance MRI images of plant root systems. To extend the application of MRI contrast agents to plant research and to develop related techniques to study root systems, we examined the applicability of the MRI contrast agent Gd-DTPA to the imaging of rice roots. Specifically, we examined the biological effects of various concentrations of Gd-DTPA on rice growth and MRI images. Analysis of electrical conductivity and plant height demonstrated that 5 mmol Gd-DTPA had little impact on rice in the short-term. The results of signal intensity and spin-lattice relaxation time (T1) analysis suggested that 5 mmol Gd-DTPA was the appropriate concentration for enhancing MRI signals. In addition, examination of the long-term effects of Gd-DTPA on plant height showed that levels of this compound up to 5 mmol had little impact on rice growth and (to some extent) increased the biomass of rice. PMID:24945975

  3. Host plant oviposition preference of Ceratapion basicorne (Coleoptera: Apionidae), a potential biological control agent of yellow starthistle

    Microsoft Academic Search

    Lincoln Smith

    2012-01-01

    Ceratapion basicorne is a weevil native to Europe and western Asia that is being evaluated as a prospective classical biological control agent of Centaurea solstitialis (yellow starthistle) in the United States. Choice oviposition experiments were conducted under laboratory conditions to help assess host plant specificity of the insect. Mean oviposition rates were highest on C. solstitialis (66% of eggs, on

  4. Effect of host-plant genotypes on the performance of three candidate biological control agents of Schinus terebinthifolius in Florida.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brazilian pepper is a weed in Florida, California and Hawaii that originates from South America. In Florida we have found two distinct types of Brazilian pepper plant and a hybrid between these two types. To control this weed, three biological control agents are being evaluated from Brazil. These ar...

  5. Defensins: antimicrobial peptides of innate immunity

    Microsoft Academic Search

    Tomas Ganz

    2003-01-01

    The production of natural antibiotic peptides has emerged as an important mechanism of innate immunity in plants and animals. Defensins are diverse members of a large family of antimicrobial peptides, contributing to the antimicrobial action of granulocytes, mucosal host defence in the small intestine and epithelial host defence in the skin and elsewhere. This review, inspired by a spate of

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

    PubMed Central

    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. PMID:23812079

  7. 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

    Microsoft Academic Search

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

    2009-01-01

    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.

  8. Cationic Antimicrobial Polymers and Their Assemblies

    PubMed Central

    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

  9. An in-vitro evaluation of the efficacy of garlic extract as an antimicrobial agent on periodontal pathogens: A microbiological study

    PubMed Central

    Shetty, Sunaina; Thomas, Biju; Shetty, Veena; Bhandary, Rahul; Shetty, Raghavendra M.

    2013-01-01

    With the rise in bacterial resistance to antibiotics, there is considerable interest in the development of other classes of antimicrobials for the control of infection. Garlic (Allium sativum Linn.) has been used as medicine since ancient times and has long been known to have antibacterial, antifungal, and antiviral properties. This study was undertaken to assess the inhibitory effect of garlic on Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, to assess the time-kill curve of P. gingivalis and A. actinomycetemcomitans, and to determine the antiproteolytic activity of garlic on P. gingivalis. Ethanolic garlic extract (EGE) and aqueous garlic extract (AGE) were prepared and the inhibitory effects of these extracts for two periodontal pathogens (P. gingivalis and A. actinomycetemcomitans) were tested. Antiproteolytic activity on protease of P. gingivalis was determined. 25 microliter (?l), 50 ?l, and 75 ?l of AGE showed 16 mm, 20 mm, and 25 mm zone of inhibition, respectively, on P. gingivalis. The AGE showed greater bacteriostatic activity against the P. gingivalis with minimum inhibitory concentration determined at 16.6 ?l/ml. The time-kill assay of AGE and EGE were compared for P. gingivalis and A. actinomycetemcomitans. AGE showed better antiproteolytic activity on total protease of P. gingivalis compared to the EGE. Thus, the study concludes the antimicrobial activity of garlic extract against periodontal pathogens, P. gingivalis, A. actinomycetemcomitans. Its action against P. gingivalis includes inhibition of total protease activity, and this raises the possibility that garlic may have therapeutic use for periodontitis and possibly other oral infections. PMID:24695825

  10. Antimicrobial polymers.

    PubMed

    Jain, Anjali; Duvvuri, L Sailaja; Farah, Shady; Beyth, Nurit; Domb, Abraham J; Khan, Wahid

    2014-12-01

    Better health is basic requirement of human being, but the rapid growth of harmful pathogens and their serious health effects pose a significant challenge to modern science. Infections by pathogenic microorganisms are of great concern in many fields such as medical devices, drugs, hospital surfaces/furniture, dental restoration, surgery equipment, health care products, and hygienic applications (e.g., water purification systems, textiles, food packaging and storage, major or domestic appliances etc.) Antimicrobial polymers are the materials having the capability to kill/inhibit the growth of microbes on their surface or surrounding environment. Recently, they gained considerable interest for both academic research and industry and were found to be better than their small molecular counterparts in terms of enhanced efficacy, reduced toxicity, minimized environmental problems, resistance, and prolonged lifetime. Hence, efforts have focused on the development of antimicrobial polymers with all desired characters for optimum activity. In this Review, an overview of different antimicrobial polymers, their mechanism of action, factors affecting antimicrobial activity, and application in various fields are given. Recent advances and the current clinical status of these polymers are also discussed. PMID:25408272

  11. Chemogeography and antimicrobial activity of essential oils from Geijera parviflora and Geijera salicifolia (Rutaceae): two traditional Australian medicinal plants.

    PubMed

    Sadgrove, Nicholas J; Gonçalves-Martins, Maximilien; Jones, Graham L

    2014-08-01

    Essential oils were hydrodistilled from 27 specimens of Geijera parviflora Lindl., (Rutaceae) and nine specimens of Geijera salicifolia Schott, collected over a wide geographic range in New South Wales, Queensland and South Australia. Essential oils were produced by traditional hydrodistillation and characterised using GC-MS. From one specimen a serendipitous discovery was made of bioactive coumarins dissolved in the hydrosol, which were the coumarins isopsoralen, xanthyletine and osthole. These coumarins were not present in the essential oil from that specimen. Using essential oil composition from all specimens, principal component analysis (PCA) demonstrated nine clusters for G. parviflora and three for G. salicifolia. Some clusters are representative of previously described chemotypes and some are reflective of possible chemotypes requiring more comprehensive sampling for confirmation. Thus, another three or four possible chemotypes of G. parviflora and one of G. salicifolia have been tentatively identified. Using micro-titre plate broth dilution assays, antibacterial and antifungal activity of all chemotypes was investigated. In this regard, the 'green oil' chemotype, restricted to G. parviflora, with major components linalool, geijerene/pregeijerene, 1,8-cineol and bicyclogermacrene, demonstrated the highest antimicrobial and free radical scavenging activity. Thus, in the light of traditional use reports of local analgaesia and bioactivity demonstrated in the current study, oils from select chemotypes of G. parviflora may be useful in suitably compounded lotions and creams designed for topical antimicrobial applications and local pain relief. In addition, because major components are known for insecticidal activities, such lotions may also be useful as topically applied insect repellents. PMID:24878365

  12. Antimicrobial and cytotoxic constituents from the seeds of Annona squamosa

    Microsoft Academic Search

    M. Mukhlesur Rahman; Shahnaj Parvin; M. Ekramul Haque; M. Ekramul Islam; Mohammad A. Mosaddik

    2005-01-01

    Annotemoyin-1, Annotemoyin-2, squamocin and cholesteryl glucopyranoside were isolated from the seeds of Annona squamosa. These compounds and plant extracts showed remarkable antimicrobial and cytotoxic activities.

  13. Antimicrobial activity and probable mechanisms of action of medicinal plants of Kenya: Withania somnifera, Warbugia ugandensis, Prunus africana and Plectrunthus barbatus.

    PubMed

    Mwitari, Peter G; Ayeka, Peter A; Ondicho, Joyce; Matu, Esther N; Bii, Christine C

    2013-01-01

    Withania somnifera, Warbugia ugandensis, Prunus africana and Plectrunthus barbatus are used traditionally in Kenya for treatment of microbial infections and cancer. Information on their use is available, but scientific data on their bioactivity, safety and mechanisms of action is still scanty. A study was conducted on the effect of organic extracts of these plants on both bacterial and fungal strains, and their mechanisms of action. Extracts were evaluated through the disc diffusion assay. Bacteria and yeast test strains were cultured on Mueller-Hinton agar and on Sabouraud dextrose agar for the filamentous fungi. A 0.5 McFarland standard suspension was prepared. Sterile paper discs 6 mm in diameter impregnated with 10 µl of the test extract (100 mg/ml) were aseptically placed onto the surface of the inoculated media. Chloramphenicol (30 µg) and fluconazole (25 µg) were used as standards. Discs impregnated with dissolution medium were used as controls. Activity of the extracts was expressed according to zone of inhibition diameter. MIC was determined at 0.78-100 mg/ml. Safety studies were carried using Cell Counting Kit 8 cell proliferation assay protocol. To evaluate extracts mechanisms of action, IEC-6 cells and RT-PCR technique was employed in vitro to evaluate Interleukin 7 cytokine. Investigated plants extracts have both bactericidal and fungicidal activity. W. ugandensis is cytotoxic at IC50<50 µg/ml with MIC values of less than 0.78 mg/ml. Prunus africana shuts down expression of IL 7 mRNA at 50 µg/ml. W. somnifera has the best antimicrobial (1.5625 mg/ml), immunopotentiation (2 times IL 7 mRNA expression) and safety level (IC50>200 µg/ml). Fractions from W. ugandensis and W. somnifera too demonstrated antimicrobial activity. Mechanisms of action can largely be attributed to cytotoxicity, Gene silencing and immunopotentiation. Use of medicinal plants in traditional medicine has been justified and possible mechanisms of action demonstrated. Studies to isolate and characterize the bioactive constituents continue. PMID:23785437

  14. Aqueous and Organic Solvent-Extracts of Selected South African Medicinal Plants Possess Antimicrobial Activity against Drug-Resistant Strains of Helicobacter pylori: Inhibitory and Bactericidal Potential

    PubMed Central

    Njume, Collise; Jide, Afolayan A.; Ndip, Roland N.

    2011-01-01

    The aim of this study was to identify sources of cheap starting materials for the synthesis of new drugs against Helicobacter pylori. Solvent-extracts of selected medicinal plants; Combretum molle, Sclerocarya birrea, Garcinia kola, Alepidea amatymbica and a single Strychnos species were investigated against 30 clinical strains of H. pylori alongside a reference control strain (NCTC 11638) using standard microbiological techniques. Metronidazole and amoxicillin were included in these experiments as positive control antibiotics. All the plants demonstrated anti-H. pylori activity with zone diameters of inhibition between 0 and 38 mm and 50% minimum inhibitory concentration (MIC50) values ranging from 0.06 to 5.0 mg/mL. MIC50 values for amoxicillin and metronidazole ranged from 0.001 to 0.63 mg/mL and 0.004 to 5.0 mg/mL respectively. The acetone extracts of C. molle and S. birrea exhibited a remarkable bactericidal activity against H. pylori killing more than 50% of the strains within 18 h at 4× MIC and complete elimination of the organisms within 24 h. Their antimicrobial activity was comparable to the control antibiotics. However, the activity of the ethanol extract of G. kola was lower than amoxicillin (P < 0.05) as opposed to metronidazole (P > 0.05). These results demonstrate that S. birrea, C. molle and G. kola may represent good sources of compounds with anti-H. pylori activity. PMID:22016616

  15. Crystallizing new approaches for antimicrobial drug discovery

    Microsoft Academic Search

    Molly B. Schmid

    2006-01-01

    Over the past decade, the sequences of microbial genomes have accumulated, changing the strategies for the discovery of novel anti-infective agents. Targets have become plentiful, yet new antimicrobial agents have been slow to emerge from this effort. In part, this reflects the long discovery and development times needed to bring new drugs to market. In addition, bottlenecks have been revealed

  16. The need for antimicrobial resistance surveillance

    Microsoft Academic Search

    David Felmingham

    2002-01-01

    Although antimicrobial agents drastically reduced patient morbidity and mortality, bacterial resistance to these agents developed shortly after their introduction. Because the laboratory diagnosis of respiratory tract infection (RTI) is not always possible, and rarely of immediate use, treatment success or failure often depends upon the availability of reliable susceptibility infor- mation at the time of therapeutic decision-making. Hence, the need

  17. Culturable leaf-associated bacteria on tomato plants and their potential as biological control agents.

    PubMed

    Enya, Junichiro; Shinohara, Hirosuke; Yoshida, Shigenobu; Tsukiboshi, Takao; Negishi, Hiromitsu; Suyama, Kazuo; Tsushima, Seiya

    2007-05-01

    Culturable leaf-associated bacteria inhabiting a plant have been considered as promising biological control agent (BCA) candidates because they can survive on the plant. We investigated the relationship between bacterial groups of culturable leaf-associated bacteria on greenhouse- and field-grown tomato leaves and their antifungal activities against tomato diseases in vitro and in vivo. In addition, the isolated bacteria were analyzed for N-acyl-homoserine lactone (AHL) and indole-3-acetic acid (IAA) production, which have been reported to associate with bacterial colonization, and resistance to a tomato alkaloid (alpha-tomatine). Leaf washings and subsequent leaf macerates were used to estimate the population size of epiphytic and more internal bacteria. Bacterial population sizes on leaves at the same position increased as the leaves aged under both greenhouse and field conditions. Field-grown tomatoes had significantly larger population sizes than greenhouse-grown tomatoes. Analysis of 16S rRNA gene (rDNA) sequencing using 887 culturable leaf-associated bacteria revealed a predominance of the Bacillus and Pseudomonas culturable leaf-associated bacterial groups on greenhouse- and field-grown tomatoes, respectively. Curtobacterium and Sphingomonas were frequently recovered from both locations. From the 2138 bacterial strains tested, we selected several strains having in vitro antifungal activity against three fungal pathogens of tomato: Botrytis cinerea, Fulvia fulva, and Alternaria solani. Among bacterial strains with strong in vitro antifungal activities, Bacillus and Pantoea tended to show strong antifungal activities, whereas Curtobacterium and Sphingomonas were not effective. The results indicated the differences in antifungal activity among predominant bacterial groups. Analysis of alpha-tomatine resistance revealed that most bacterial strains in the dominant groups exhibited moderate or high resistance to alpha-tomatine in growth medium. Furthermore, some Sphingomonas and Pantoea strains showed AHL and IAA production activities. Strain 125NP12 (Pantoea ananatis) showed particular alpha-tomatine resistance, and AHL and IAA production had the highest protective value (91.7) against gray mold. Thus, the differences of these physiological properties among dominant bacteria may be associated with the disease suppression ability of BCAs on tomato plants. PMID:17356949

  18. Synthetic biology of antimicrobial discovery

    PubMed Central

    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

  19. Synthetic biology of antimicrobial discovery.

    PubMed

    Zakeri, Bijan; Lu, Timothy K

    2013-07-19

    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

  20. Animation of Antimicrobial Resistance

    MedlinePLUS Videos and Cool Tools

    ... 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 ...

  1. Antimicrobial Surfaces

    Microsoft Academic Search

    Joerg C. Tiller

    \\u000a In this review, the general principles of antimicrobial surfaces will be discussed in detail. Because many common products\\u000a that keep microbes off surfaces have been banned in the past decade, the search for alternatives is in full run. In recent\\u000a research, numerous new ways to produce so-called self-sterilizing surfaces have been introduced. These technologies are discussed\\u000a with respect to their

  2. Animal Antimicrobial Peptides: An Overview

    E-print Network

    Pompeu Fabra, Universitat

    Animal Antimicrobial Peptides: An Overview David Andreu1 Luis Rivas2 1 Universitat de Barcelona concepts of nonspecific and specific de- fense systems for plants and animals, respectively, are being defense systems, while on the other hand innate (nonadaptive) immunity in animals largely de- pends

  3. First Discovery of Acetone Extract from Cottonseed Oil Sludge as a Novel Antiviral Agent against Plant Viruses

    PubMed Central

    Zhao, Lei; Feng, Chaohong; Hou, Caiting; Hu, Lingyun; Wang, Qiaochun; Wu, Yunfeng

    2015-01-01

    A novel acetone extract from cottonseed oil sludge was firstly discovered against plant viruses including Tobacco mosaic virus (TMV), Rice stripe virus (RSV) and Southern rice black streaked dwarf virus (SRBSDV). Gossypol and ?-sitosterol separated from the acetone extract were tested for their effects on anti-TMV and analysed by nuclear magnetic resonance (NMR) assay. In vivo and field trials in different geographic distributions and different host varieties declared that this extract mixture was more efficient than the commercial agent Ningnanmycin with a broad spectrum of anti-plant-viruses activity. No phytotoxic activity was observed in the treated plants and environmental toxicology showed that this new acetone extract was environmentally friendly, indicating that this acetone extract has potential application in the control of plant virus in the future. PMID:25705894

  4. First discovery of acetone extract from cottonseed oil sludge as a novel antiviral agent against plant viruses.

    PubMed

    Zhao, Lei; Feng, Chaohong; Hou, Caiting; Hu, Lingyun; Wang, Qiaochun; Wu, Yunfeng

    2015-01-01

    A novel acetone extract from cottonseed oil sludge was firstly discovered against plant viruses including Tobacco mosaic virus (TMV), Rice stripe virus (RSV) and Southern rice black streaked dwarf virus (SRBSDV). Gossypol and ?-sitosterol separated from the acetone extract were tested for their effects on anti-TMV and analysed by nuclear magnetic resonance (NMR) assay. In vivo and field trials in different geographic distributions and different host varieties declared that this extract mixture was more efficient than the commercial agent Ningnanmycin with a broad spectrum of anti-plant-viruses activity. No phytotoxic activity was observed in the treated plants and environmental toxicology showed that this new acetone extract was environmentally friendly, indicating that this acetone extract has potential application in the control of plant virus in the future. PMID:25705894

  5. Antimicrobial activity of borate-buffered solutions.

    PubMed Central

    Houlsby, R D; Ghajar, M; Chavez, G O

    1986-01-01

    A minimal salts medium adjusted to physiological pH and osmolality was buffered with either 0.3% phosphate or 1.2% borate and evaluated for antimicrobial activity. The borate-buffered medium, either with or without a carbon source, exhibited significant antimicrobial activity against 15 Pseudomonas strains, 12 strains of enteric bacteria, and 7 strains of staphylococci. The borate-buffered system appears suitable for use as a generic vehicle for ophthalmic pharmaceutical agents. PMID:3729341

  6. Boosting Salt Resistance of Short Antimicrobial Peptides

    PubMed Central

    Chu, Hung-Lun; Yu, Hui-Yuan; Yip, Bak-Sau; Chih, Ya-Han; Liang, Chong-Wen; Cheng, Hsi-Tsung

    2013-01-01

    The efficacies of many antimicrobial peptides are greatly reduced under high salt concentrations, therefore limiting their use as pharmaceutical agents. Here, we describe a strategy to boost salt resistance and serum stability of short antimicrobial peptides by adding the nonnatural bulky amino acid ?-naphthylalanine to their termini. The activities of the short salt-sensitive tryptophan-rich peptide S1 were diminished at high salt concentrations, whereas the activities of its ?-naphthylalanine end-tagged variants were less affected. PMID:23716061

  7. Chemical composition, antimicrobial and insecticidal activities of the essential oils of Conyza linifolia and Chenopodium ambrosioides.

    PubMed

    Harraz, Fathalla M; Hammoda, Hala M; El Ghazouly, Maged G; Farag, Mohamed A; El-Aswad, Ahmed F; Bassam, Samar M

    2015-05-01

    Two essential oil-containing plants growing wildly in Egypt: Conyza linifolia (Willd.) Täckh. (Asteraceae) and Chenopodium ambrosioides L. (Chenopodiaceae) were subjected to essential oil analysis and biological investigation. The essential oils from both plants were prepared by hydrodistillation, and GC/MS was employed for volatiles profiling. This study is the first to perform GC/MS analysis of C. linifolia essential oil growing in Egypt. C. linifolia essential oil contained mainly sesquiterpenes, while that of C. ambrosioides was rich in monoterpenes. Ascaridole, previously identified as the major component of the latter, was found at much lower levels. In addition, the oils were investigated for their antimicrobial activity against two Gram positive and two Gram negative bacteria, and one fungus. The insecticidal activities of both oils, including mosquitocidal and pesticidal potentials, were also evaluated. The results of biological activities encourage further investigation of the two oils as antimicrobial and insecticidal agents of natural origin. PMID:25495783

  8. Defence-related gene expression in transgenic lemon plants producing an antimicrobial Trichoderma harzianum endochitinase during fungal infection

    Microsoft Academic Search

    Gaetano Distefano; Stefano La Malfa; Alessandro Vitale; Matteo Lorito; Ziniu Deng; Alessandra Gentile

    2008-01-01

    Constitutive over-expression of antifungal genes from microorganisms involved in plant defence mechanisms represents a promising\\u000a strategy for conferring genetic resistance against a broad range of plant pathogenic fungi. In the present work, two transgenic\\u000a lemon clones with the chit42 gene from Trichoderma harzianum were tested for resistance to fungal disease and expression level of defence-related genes was evaluated. Different resistance-related

  9. Antimicrobial Polymers with Metal Nanoparticles

    PubMed Central

    Palza, Humberto

    2015-01-01

    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. PMID:25607734

  10. Antiproliferative activity of the non-myelotoxic antitumour agent of plant origin, Thaliblastine, on two human glioma cell lines

    Microsoft Academic Search

    D. K. Todorov; W. J. Zeller

    1992-01-01

    Summary The antiproliferative activity of the non-myelotoxic antitumour agent of plant origin, Thaliblastine, on two human glioma cell lines is described. Thaliblastine was added once one day following start of culture; proliferation was monitored over 7 days. The anti-proliferative activity of Thaliblastine was strongly dependent on concentration and time of incubation. The ID50 of Thaliblastine in T406 and GW27 glioma

  11. Effect of Plant Age on Endophytic Bacterial Diversity of Balloon Flower ( Platycodon grandiflorum ) Root and Their Antimicrobial Activities

    Microsoft Academic Search

    Jong Min Kim; Myoung Geun Yun; Ji Joong Cho; Eun Jin Kim; Young Han Lee; Han Dae Yun

    2010-01-01

    Balloon flower (Platycodon grandiflorum) is widely cultivated vegetable and used as a remedy for asthma in East Asia. Experiments were conducted to isolate endophytic\\u000a bacteria from 1-, 3-, and 6-year-old balloon flower roots and to analyze the enzymatic, antifungal, and anti-human pathogenic\\u000a activities of the potential endophytic biocontrol agents obtained. Total 120 bacterial colonies were isolated from the interior\\u000a of

  12. Genome Sequence of the Plant Pathogen and Biotechnology Agent Agrobacterium tumefaciens C58

    Microsoft Academic Search

    Brad Goodner; Gregory Hinkle; Stacie Gattung; Nancy Miller; Mary Blanchard; Barbara Qurollo; Barry S. Goldman; Yongwei Cao; Manor Askenazi; Conrad Halling; Lori Mullin; Kathryn Houmiel; Jeffrey Gordon; Mark Vaudin; Oleg Iartchouk; Andrew Epp; Fang Liu; Clifford Wollam; Mike Allinger; Dahlia Doughty; Charlaine Scott; Courtney Lappas; Brian Markelz; Casey Flanagan; Chris Crowell; Jordan Gurson; Caroline Lomo; Carolyn Sear; Graham Strub; Chris Cielo; Steven Slater

    2001-01-01

    Agrobacterium tumefaciens is a plant pathogen capable of transferring a defined segment of DNA to a host plant, generating a gall tumor. Replacing the transferred tumor-inducing genes with exogenous DNA allows the introduction of any desired gene into the plant. Thus, A. tumefaciens has been critical for the development of modern plant genetics and agricultural biotechnology. Here we describe the

  13. Effect of Plant Derived Antimicrobials on Salmonella Enteritidis Adhesion to and Invasion of Primary Chicken Oviduct Epithelial Cells in vitro and Virulence Gene Expression.

    PubMed

    Upadhyaya, Indu; Upadhyay, Abhinav; Kollanoor-Johny, Anup; Darre, Michael J; Venkitanarayanan, Kumar

    2013-01-01

    Salmonella Enteritidis (SE) is a major foodborne pathogen in the United States and one of the most frequently reported Salmonella serotypes globally. Eggs are the most common food product associated with SE infections in humans. The pathogen colonizes the intestinal tract in layers, and migrates to reproductive organs systemically. Since adhesion to and invasion of chicken oviduct epithelial cells (COEC) is critical for SE colonization in reproductive tract, reducing these virulence factors could potentially decrease egg yolk contamination. This study investigated the efficacy of sub-inhibitory concentrations of three plant-derived antimicrobials (PDAs), namely carvacrol, thymol and eugenol in reducing SE adhesion to and invasion of COEC, and survival in chicken macrophages. In addition, the effect of PDAs on SE genes critical for oviduct colonization and macrophage survival was determined using real-time quantitative PCR (RT-qPCR). All PDAs significantly reduced SE adhesion to and invasion of COEC (p < 0.001). The PDAs, except thymol consistently decreased SE survival in macrophages (p < 0.001). RT-qPCR results revealed down-regulation in the expression of genes involved in SE colonization and macrophage survival (p < 0.001). The results indicate that PDAs could potentially be used to control SE colonization in chicken reproductive tract; however, in vivo studies validating these results are warranted. PMID:23698782

  14. Plant-Derived Antimicrobials Reduce E. coli O157:H7 Virulence Factors Critical for Colonization in Cattle Gastrointestinal Tract In Vitro

    PubMed Central

    Ananda Baskaran, Sangeetha

    2014-01-01

    This study investigated the effect of subinhibitory concentrations (SIC) of five plant-derived antimicrobials (PDAs), namely, trans cinnamaldehyde, eugenol, carvacrol, thymol, and ?-resorcylic acid, on E. coli O157:H7 (EHEC) attachment and invasion of cultured bovine colonic (CO) and rectoanal junction (RAJ) epithelial cells. In addition, PDAs' effect on EHEC genes critical for colonization of cattle gastrointestinal tract (CGIT) was determined in bovine rumen fluid (RF) and intestinal contents (BICs). Primary bovine CO and RAJ epithelial cells were established and were separately inoculated with three EHEC strains with or without (control) SIC of each PDA. Following incubation, EHEC that attached and invaded the cells were determined. Furthermore, the expression of EHEC genes critical for colonization in cattle was investigated using real-time, quantitative polymerase chain reaction in RF and BICs. All the PDAs decreased EHEC invasion of CO and RAJ epithelial cells (P < 0.05). The PDAs also downregulated (P < 0.05) the expression of EHEC genes critical for colonization in CGIT. Results suggest that the PDAs could potentially be used to control EHEC colonization in cattle; however follow-up in vivo studies in cattle are warranted. PMID:25050328

  15. Antimicrobial peptides from scorpion venoms.

    PubMed

    Harrison, Patrick L; Abdel-Rahman, Mohamed A; Miller, Keith; Strong, Peter N

    2014-09-01

    The need for new antimicrobial agents is becoming one of the most urgent requirements in modern medicine. The venoms of many different species are rich sources of biologically active components and various therapeutic agents have been characterized including antimicrobial peptides (AMPs). Due to their potent activity, low resistance rates and unique mode of action, AMPs have recently received much attention. This review focuses on AMPs from the venoms of scorpions and examines all classes of AMPs found to date. It gives details of their biological activities with reference to peptide structure. The review examines the mechanism of action of AMPs and with this information, suggests possible mechanisms of action of less well characterised peptides. Finally, the review examines current and future trends of scorpion AMP research, by discussing recent successes obtained through proteomic and transcriptomic approaches. PMID:24951876

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

    PubMed Central

    Yazdankhah, Siamak; Rudi, Knut; Bernhoft, Aksel

    2014-01-01

    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. PMID:25317117

  17. Simultaneous detection and quantification of select nitromusks, antimicrobial agent, and antihistamine in fish of grocery stores by gas chromatography-mass spectrometry.

    PubMed

    Foltz, James; Abdul Mottaleb, M; Meziani, Mohammed J; Rafiq Islam, M

    2014-07-01

    Continually detected biologically persistent nitromusks; galaxolide (HHCB), tonalide (AHTN) and musk ketone (MK), antimicrobial triclosan (TCS), and antihistamine diphenhydramine (DPH) were examined for the first time in edible fillets originating from eight fish species grown in salt- and fresh-water. The sampled fish collected from local grocery stores were homogenized, extracted, pre-concentrated and analyzed by gas chromatography-mass spectrometry (GC-MS) using selected ion monitoring (SIM). The presence of the target compounds in fish extracts was confirmed based on similar mass spectral features and retention behavior with standards. Internal standard based calibration plots were used for quantification. The HHCB, AHTN, TCS and DPH were consistently observed with concentration of 0.163-0.892, 0.068-0.904, 0.189-1.182, and 0.942-7.472 ng g(-1), respectively. These values are at least 1-3 orders of magnitude lower than those obtained in environmental fish specimens. The MK was not detected in any fish. PMID:24377446

  18. Antioxidant, Antimicrobial Activity and Toxicity Test of Pilea microphylla

    PubMed Central

    Modarresi Chahardehi, Amir; Ibrahim, Darah; Fariza Sulaiman, Shaida

    2010-01-01

    A total of 9 plant extracts were tested, using two different kinds of extracting methods to evaluate the antioxidant and antimicrobial activities from Pilea microphylla (Urticaceae family) and including toxicity test. Antioxidant activity were tested by using DPPH free radical scavenging, also total phenolic contents and total flavonoid contents were determined. Toxicity assay carried out by using brine shrimps. Methanol extract of method I (ME I) showed the highest antioxidant activity at 69.51 ± 1.03. Chloroform extract of method I (CE I) showed the highest total phenolic contents at 72.10 ± 0.71 and chloroform extract of method II (CE II) showed the highest total flavonoid contents at 60.14 ± 0.33. The antimicrobial activity of Pilea microphylla extract was tested in vitro by using disc diffusion method and minimum inhibitory concentration (MIC). The Pilea microphylla extract showed antibacterial activity against some Gram negative and positive bacteria. The extracts did not exhibit antifungal and antiyeast activity. The hexane extract of method I (HE I) was not toxic against brine shrimp (LC50 value was 3880??g/ml). Therefore, the extracts could be suitable as antimicrobial and antioxidative agents in food industry. PMID:20652052

  19. Use of low-cost gelling agents and support matrices for industrial scale plant tissue culture

    Microsoft Academic Search

    Parthasarathi Bhattacharya; Satyahari Dey; Bimal Chandra Bhattacharyya

    1994-01-01

    The efficacies of sago (from Metroxylon sagu Rottb.) and isubgol (from Plantago ovata Forsk.) as gelling agents and those of filter paper, nylon cloth, polystyrene foam and glass wool cloth as support matrices have been tested for the propagation of plantlets of chrysanthemum (Dendranthema grandiflora Tzvelev). The performances of these low-cost gelling agents and matrices were found satisfactory and could

  20. Enabling Virtual Screening of Potent and Safer Antimicrobial Agents Against Noma: mtk-QSBER Model for Simultaneous Prediction of Antibacterial Activities and ADMET Properties.

    PubMed

    Speck-Planche, Alejandro; Cordeiro, M N D S

    2015-01-01

    Neglected diseases are infections that thrive mainly among underdeveloped countries, particularly those belonging to regions found in Asia, Africa, and America. One of the most complex diseases is noma, a dangerous health condition characterized by a polymicrobial and opportunistic nature. The search for potent and safer antibacterial agents against this disease is therefore a goal of particular interest. Chemoinformatics can be used to rationalize the discovery of drug candidates, diminishing time and financial resources. However, in the case of noma, there is no in silico model available for its use in the discovery of efficacious antibacterial agents. This work is devoted to report the first mtk-QSBER model, which integrates dissimilar kinds of chemical and biological data. The model was generated with the aim of simultaneously predicting activity against bacteria present in noma, and ADMET (absorption, distribution, metabolism, elimination, toxicity) parameters. The mtk-QSBER model was constructed by employing a large and heterogeneous dataset of chemicals and displayed accuracies higher than 90% in both training and prediction sets. We confirmed the practical applicability of the model by predicting multiple profiles of the investigational antibacterial drug delafloxacin, and the predictions converged with the experimental reports. To date, this is the first model focused on the virtual search for desirable anti-noma agents. PMID:25769968

  1. Antifungal proteins: More than antimicrobials?

    PubMed Central

    Hegedüs, Nikoletta; Marx, Florentine

    2013-01-01

    Antimicrobial proteins (AMPs) are widely distributed in nature. In higher eukaryotes, AMPs provide the host with an important defence mechanism against invading pathogens. AMPs of lower eukaryotes and prokaryotes may support successful competition for nutrients with other microorganisms of the same ecological niche. AMPs show a vast variety in structure, function, antimicrobial spectrum and mechanism of action. Most interestingly, there is growing evidence that AMPs also fulfil important biological functions other than antimicrobial activity. The present review focuses on the mechanistic function of small, cationic, cysteine-rich AMPs of mammals, insects, plants and fungi with antifungal activity and specifically aims at summarizing current knowledge concerning additional biological properties which opens novel aspects for their future use in medicine, agriculture and biotechnology. PMID:23412850

  2. Rapid 'one-pot' synthesis of a novel benzimidazole-5-carboxylate and its hydrazone derivatives as potential anti-inflammatory and antimicrobial agents.

    PubMed

    Vasantha, Kumar; Basavarajaswamy, Guru; Vaishali Rai, M; Boja, Poojary; Pai, Vinitha R; Shruthi, N; Bhat, Mahima

    2015-04-01

    A novel series of N-arylidene-2-(2,4-dichloro phenyl)-1-propyl-1H-benzo[d] imidazole-5-carbohydrazides having different substitution on the arylidene part were synthesized in good yield. The core nucleus benzimidazole-5-carboxylate (5) was efficiently synthesized by 'one-pot' nitro reductive cyclization reaction between ethyl-3-nitro-4-(propylamino)benzoate and 2,4-dichlorobenzaldehyde using sodium dithionite in dimethylsulfoxide. This 'one-pot' reaction was proceeded very smoothly, in short reaction time with an excellent yield. All the compounds (7a-r) were screened for their in vivo anti-inflammatory and in vitro antimicrobial activity. Most of the compounds exhibited remarkable paw-edema inhibition in the initial one hour of administration indicating the higher potentiality of these molecules. In particular, compounds 7a, 7d, 7f and 7g displayed a high level of carrageenan-induced paw edema inhibition compared to that of indomethacin. Compound 7p exhibited very good antibacterial activity and antifungal activity with a MIC of 3.12?g/mL against most of the tested organisms. Furthermore, compounds 7d, 7f, 7h and 7p found to be good inhibitors of Aspergillus niger with MIC of 3.12?g/mL. Cytotoxicity of the potent compounds 7d, 7f and 7p was checked using MDA MB-231 breast cancer cell line and are found to be non toxic at the highest concentration used (i.e., 10?g/mL). PMID:25765910

  3. Trends in the susceptibility of methicillin-resistant Staphylococcus aureus to nine antimicrobial agents, including ceftobiprole, nemonoxacin, and tyrothricin: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2006-2010.

    PubMed

    Chen, Y-H; Liu, C-Y; Ko, W-C; Liao, C-H; Lu, P-L; Huang, C-H; Lu, C-T; Chuang, Y-C; Tsao, S-M; Chen, Y-S; Liu, Y-C; Chen, W-Y; Jang, T-N; Lin, H-C; Chen, C-M; Shi, Z-Y; Pan, S-C; Yang, J-L; Kung, H-C; Liu, C-E; Cheng, Y-J; Liu, J-W; Sun, W; Wang, L-S; Yu, K-W; Chiang, P-C; Lee, M-H; Lee, C-M; Hsu, G-J; Hsueh, P-R

    2014-02-01

    This study investigated the in vitro susceptibilities of methicillin-resistant Staphylococcus aureus (MRSA) to nine antimicrobial agents in Taiwan. A total of 1,725 isolates were obtained from 20 hospitals throughout Taiwan from 2006 to 2010. The minimum inhibitory concentrations (MICs) of the nine agents were determined by the agar dilution method. The MICs of mupirocin and tyrothricin were determined for 223 MRSA isolates collected from 2009 to 2010. For vancomycin, 99.7 % were susceptible; however, 30.0 % (n?=?517) exhibited MICs of 2 ?g/ml and 0.3 % (n?=?6) demonstrated intermediate susceptibility (MICs of 4 ?g/ml). Nearly all isolates (? 99.9 %) were susceptible to teicoplanin, linezolid, and daptomycin. The MIC90 values were 2 ?g/ml for ceftobiprole and 1 ?g/ml for nemonoxacin. The MIC90 values of mupirocin and tyrothricin were 0.12 and 4 ?g/ml, respectively. MIC creep was noted for daptomycin during this period, but not for vancomycin, teicoplanin, linezolid, or tigecycline. For isolates with vancomycin MICs of 2 ?g/ml, the MIC90 values were 2 ?g/ml for teicoplanin, 0.5 ?g/ml for daptomycin, and 0.5 ?g/ml for tigecycline. Those values were four- to eight-fold higher than those among isolates with vancomycin MICs of 0.5 ?g/ml (2, 0.06, and 0.12 ?g/ml, respectively). Of the nine MRSA isolates exhibiting non-susceptibility to vancomycin (n?=?6), teicoplanin (n?=?1), daptomycin (n?=?2), or tigecycline (n?=?1), all had different pulsotypes, indicating the absence of intra-hospital or inter-hospital spread. The presence of a high proportion of MRSA isolates with elevated MICs (2 ?g/ml) and MIC creep of daptomycin might alert clinicians on the therapy for serious MRSA infections in Taiwan. PMID:23955154

  4. Antimicrobial Properties of Light-activated Polyurethane Containing Indocyanine Green

    Microsoft Academic Search

    Stefano Perni; Jonathan Pratten; Michael Wilson; Clara Piccirillo; Ivan P. Parkin; Polina Prokopovich

    2011-01-01

    The aim of this study was to produce novel antimicrobial polymers containing the light-activated antimicrobial agent indocyanine green (ICG). The novel materials were prepared by swelling polyurethane in acetone containing water and ICG, followed by solvent evaporation. The uptake of ICG was dependent upon the ratio of acetone to water. Only at a ratio of 99 parts acetone to 1

  5. Field experiments to evaluate host plant specificity of prospective agents of Onopordum acanthium in Bulgaria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scotch thistle, Onopordum acanthium, is an invasive alien weed in North America that originates from Europe. Previous field observations in Bulgaria have confirmed the presence of prospective biological control agents including Cassida rubiginosa, Chaetostomella cylindrica, Eublemma amoena, Larinus ...

  6. [Plant fungi: the first pathogenic agents recognized in the history of science].

    PubMed

    Rapilly, F

    2001-10-01

    The eighteenth century is the beginning of the scientific emergence of plant pathology. Naturalists disproved spontaneous generation, meteorological and supernatural origins of plant diseases. It is necessary to explain plant alterations and to find possibilities of control to reduce significant losses of yield and to limit famine. In 1728, the words 'plant parasite', 'plant disease', and 'epidemics' were used for the first time. In 1755, the first seed treatment and, in 1805 the first description of a whole cycle of plant disease were proposed. In the nineteenth century much work on bunt and rusts of wheat, potato downy mildew, and grape vine powdery mildew established the scientific status of plant pathology. A retrospective analysis of these early developments shows a very good concordance with Koch's postulate published one century later. PMID:11570276

  7. Phytochemical Screening and Antimicrobial Activity of Some Medicinal Plants Against Multi-drug Resistant Bacteria from Clinical Isolates

    PubMed Central

    Dahiya, Praveen; Purkayastha, Sharmishtha

    2012-01-01

    The in vitro antibacterial activity of various solvents and water extracts of aloe vera, neem, bryophyllum, lemongrass, tulsi, oregano, rosemary and thyme was assessed on 10 multi-drug resistant clinical isolates from both Gram-positive and Gram-negative bacteria and two standard strains including Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. The zone of inhibition as determined by agar well diffusion method varied with the plant extract, the solvent used for extraction, and the organism tested. Klebsiella pneumoniae 2, Escherichia coli 3 and Staphylococcus aureus 3 were resistant to the plant extracts tested. Moreover, water extracts did not restrain the growth of any tested bacteria. Ethanol and methanol extracts were found to be more potent being capable of exerting significant inhibitory activities against majority of the bacteria investigated. Staphylococcus aureus 1 was the most inhibited bacterial isolate with 24 extracts (60%) inhibiting its growth whereas Escherichia coli 2 exhibited strong resistance being inhibited by only 11 extracts (28%). The results obtained in the agar diffusion plates were in fair correlation with that obtained in the minimum inhibitory concentration tests. The minimum inhibitory concentration of tulsi, oregano, rosemary and aloe vera extracts was found in the range of 1.56-6.25 mg/ml for the multi-drug resistant Staphylococcus aureus isolates tested whereas higher values (6.25-25 mg/ml) were obtained against the multi-drug resistant isolates Klebsiella pneumoniae 1 and Escherichia coli 1 and 2. Qualitative phytochemical analysis demonstrated the presence of tannins and saponins in all plants tested. Thin layer chromatography and bioautography agar overlay assay of ethanol extracts of neem, tulsi and aloe vera indicated flavonoids and tannins as major active compounds against methicillin-resistant Staphylococcus aureus. PMID:23716873

  8. LAMP: A Database Linking Antimicrobial Peptides

    PubMed Central

    Lu, Hairong; Li, Guodong; Huang, Qingshan

    2013-01-01

    The frequent emergence of drug-resistant bacteria has created an urgent demand for new antimicrobial agents. Traditional methods of novel antibiotic development are almost obsolete. Antimicrobial peptides (AMPs) are now regarded as a potential solution to revive the traditional methods of antibiotic development, although, until now, many AMPs have failed in clinical trials. A comprehensive database of AMPs with information about their antimicrobial activity and cytotoxicity will help promote the process of finding novel AMPs with improved antimicrobial activity and reduced cytotoxicity and eventually accelerate the speed of translating the discovery of new AMPs into clinical or preclinical trials. LAMP, a database linking AMPs, serves as a tool to aid the discovery and design of AMPs as new antimicrobial agents. The current version of LAMP has 5,547 entries, comprising 3,904 natural AMPs and 1,643 synthetic peptides. The database can be queried using either simply keywords or combinatorial conditions searches. Equipped with the detailed antimicrobial activity and cytotoxicity data, the cross-linking and top similar AMPs functions implemented in LAMP will help enhance our current understanding of AMPs and this may speed up the development of new AMPs for medical applications. LAMP is freely available at: http://biotechlab.fudan.edu.cn/database/lamp. PMID:23825543

  9. Antimicrobial resistance changes in enteric Escherichia coli of horses during hospitalisation: resistance profiling of isolates.

    PubMed

    Williams, A; Christley, R M; McKane, S A; Roberts, V L H; Clegg, P D; Williams, N J

    2013-01-01

    The aim of this study was to determine whether hospitalisation of horses leads to increased antimicrobial resistance in equine faecal Escherichia coli isolates. E. coli were cultured from faecal samples of horses on admission and after 7 days of hospitalisation; antimicrobial susceptibility was determined for eight antimicrobial agents. Resistance profiles of E. coli isolates were grouped into clusters, which were analysed to determine resistance patterns. Resistance to 7/8 antimicrobial agents and multi-drug resistance (MDR; resistance to ?3 antimicrobial classes) were significantly higher after 7 days of hospitalisation. Forty-eight resistance profiles were identified; 15/48 were present on day 0 only, 16/48 on day 7 only and 17/48 at both times of sampling. There was a significant association between day 7 profiles and resistance detected to an increased number of antimicrobial agents. Hospitalisation of horses for 7 days resulted in alterations in equine faecal E. coli antimicrobial resistance profiles. PMID:22967926

  10. Antimicrobial silver: An unprecedented anion effect

    PubMed Central

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

    2014-01-01

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

  11. Antimicrobial-Coated Granules for Disinfecting Water

    NASA Technical Reports Server (NTRS)

    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.

  12. Antimicrobial silver: An unprecedented anion effect

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  13. The Global Challenge of Antimicrobial Resistance: Insights from Economic Analysis

    PubMed Central

    Eggleston, Karen; Zhang, Ruifang; Zeckhauser, Richard J.

    2010-01-01

    The prevalence of antimicrobial resistance (AR) limits the therapeutic options for treatment of infections, and increases the social benefit from disease prevention. Like an environmental resource, antimicrobials require stewardship. The effectiveness of an antimicrobial agent is a global public good. We argue for greater use of economic analysis as an input to policy discussion about AR, including for understanding the incentives underlying health behaviors that spawn AR, and to supplement other methods of tracing the evolution of AR internationally. We also discuss integrating antimicrobial stewardship into global health governance. PMID:20948953

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

    PubMed Central

    2011-01-01

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

  15. Defensins: antimicrobial peptides of innate immunity.

    PubMed

    Ganz, Tomas

    2003-09-01

    The production of natural antibiotic peptides has emerged as an important mechanism of innate immunity in plants and animals. Defensins are diverse members of a large family of antimicrobial peptides, contributing to the antimicrobial action of granulocytes, mucosal host defence in the small intestine and epithelial host defence in the skin and elsewhere. This review, inspired by a spate of recent studies of defensins in human diseases and animal models, focuses on the biological function of defensins. PMID:12949495

  16. Recent Advances in the Discovery and Development of Plant-derived Chemotherapeutic Agents

    Microsoft Academic Search

    Kuo-Hsiung Lee

    2005-01-01

    Plants have long served as traditional herbal medicines, and natural products make excellent leads for new drug development. New plant-derived medicines can come from three sources: single active principles, active fractions, and validated prescriptions. Conventionally, for single active compounds, lead discovery and drug development involve highly efficient bio- activity-directed fractionation and isolation (BDFI) coupled with structural characterization, analog synthesis, and

  17. A comparative evaluation of some blood sugar lowering agents of plant origin

    Microsoft Academic Search

    R. R Chattopadhyay

    1999-01-01

    A comparison of blood sugar lowering activity of four important medicinal plants (Azadirachta indica, Gymnema sylvestre, Catharanthus roseus and Ocimum sanctum) were carried out against normal and streptozotocin-induced diabetic rat models. The plant extracts decreased the blood sugar level in varying degrees. Blood sugar lowering unit (BLU) of activity of each leaf extract and tolbutamide was calculated by ED50 values.

  18. Effective selection and regeneration of transgenic rice plants with mannose as selective agent

    Microsoft Academic Search

    Paola Lucca; Xudong Ye; Ingo Potrykus

    2001-01-01

    A new method for the selection of transgenic rice plants without the use of antibiotics or herbicides has been developed. The phosphomannose isomerase (PMI) gene from Escherichia coli has been cloned and consitutively expressed in japonica rice variety TP 309. The PMI gene was transferred to immature rice embryos by Agrobacterium-mediated transformation, which allowed the selection of transgenic plants with

  19. Role of plant phenology in mediating interactions between two biological control agents for spotted knapweed

    Microsoft Academic Search

    R. S. Bourchier; M. L. Crowe

    2011-01-01

    The role of spotted knapweed phenology on the attack rate of two seed-head insects Urophora affinis and Larinus minutus was assessed in a series of field studies at four study sites in south-eastern British Columbia, Canada. Slow or later developing knapweed plants had more seed heads that contained only single or multiple U. affinis whereas early or faster developing plants

  20. Gum katira – a cheap gelling agent for plant tissue culture media

    Microsoft Academic Search

    Neeru Jain; Shashi B. Babbar

    2002-01-01

    Gum katira, an insoluble gum derived from the bark of Cochlospermum religiosum, has been successfully used as a gelling agent in tissue culture media for in vitro shoot formation and rooting in Syzygium cuminii and somatic embryogenesis in Albizzia lebbeck. The epicotyl segments, excised from in vitro grown seedlings of S. cuminii, developed shoots when cultured on MS medium (Murashige