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Sample records for designer proline-rich antibacterial

  1. Thermodynamic dissection of the binding energetics of proline-rich peptides to the Abl-SH3 domain: implications for rational ligand design.

    Science.gov (United States)

    Palencia, Andrés; Cobos, Eva S; Mateo, Pedro L; Martínez, Jose C; Luque, Irene

    2004-02-13

    The inhibition of the interactions between SH3 domains and their targets is emerging as a promising therapeutic strategy. To date, rational design of potent ligands for these domains has been hindered by the lack of understanding of the origins of the binding energy. We present here a complete thermodynamic analysis of the binding energetics of the p41 proline-rich decapeptide (APSYSPPPPP) to the SH3 domain of the c-Abl oncogene. Isothermal titration calorimetry experiments have revealed a thermodynamic signature for this interaction (very favourable enthalpic contributions opposed by an unfavourable binding entropy) inconsistent with the highly hydrophobic nature of the p41 ligand and the Abl-SH3 binding site. Our structural and thermodynamic analyses have led us to the conclusion, having once ruled out any possible ionization events or conformational changes coupled to the association, that the establishment of a complex hydrogen-bond network mediated by water molecules buried at the binding interface is responsible for the observed thermodynamic behaviour. The origin of the binding energetics for proline-rich ligands to the Abl-SH3 domain is further investigated by a comparative calorimetric analysis of a set of p41-related ligands. The striking effects upon the enthalpic and entropic contributions provoked by conservative substitutions at solvent-exposed positions in the ligand confirm the complexity of the interaction. The implications of these results for rational ligand design are discussed.

  2. Antibacterial surface design - Contact kill

    Science.gov (United States)

    Kaur, Rajbir; Liu, Song

    2016-08-01

    Designing antibacterial surfaces has become extremely important to minimize Healthcare Associated Infections which are a major cause of mortality worldwide. A previous biocide-releasing approach is based on leaching of encapsulated biocides such as silver and triclosan which exerts negative impacts on the environment and potentially contributes to the development of bacterial resistance. This drawback of leachable compounds led to the shift of interest towards a more sustainable and environmentally friendly approach: contact-killing surfaces. Biocides that can be bound onto surfaces to give the substrates contact-active antibacterial activity include quaternary ammonium compounds (QACs), quaternary phosphoniums (QPs), carbon nanotubes, antibacterial peptides, and N-chloramines. Among the above, QACs and N-chloramines are the most researched contact-active biocides. We review the engineering of contact-active surfaces using QACs or N-chloramines, the modes of actions as well as the test methods. The charge-density threshold of cationic surfaces for desired antibacterial efficacy and attempts to combine various biocides for the generation of new contact-active surfaces are discussed in detail. Surface positive charge density is identified as a key parameter to define antibacterial efficacy. We expect that this research field will continue to attract more research interest in view of the potential impact of self-disinfective surfaces on healthcare-associated infections, food safety and corrosion/fouling resistance required on industrial surfaces such as oil pipes and ship hulls.

  3. Sequential assignment of proline-rich regions in proteins: Application to modular binding domain complexes

    International Nuclear Information System (INIS)

    Kanelis, Voula; Donaldson, Logan; Muhandiram, D.R.; Rotin, Daniela; Forman-Kay, Julie D.; Kay, Lewis E.

    2000-01-01

    Many protein-protein interactions involve amino acid sequences containing proline-rich motifs and even poly-proline stretches. The lack of amide protons in such regions complicates assignment, since 1 HN-based triple-resonance assignment strategies cannot be employed. Two such systems that we are currently studying include an SH2 domain from the protein Crk with a region containing 9 prolines in a 14 amino acid sequence, as well as a WW domain that interacts with a proline-rich target. A modified version of the HACAN pulse scheme, originally described by Bax and co-workers [Wang et al. (1995) J. Biomol. NMR, 5, 376-382], and an experiment which correlates the intra-residue 1 H α , 13 C α / 13 C β chemical shifts with the 15 N shift of the subsequent residue are presented and applied to the two systems listed above, allowing sequential assignment of the molecules

  4. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium

    DEFF Research Database (Denmark)

    Arcanjo, Daniel Dias Rufino; Vasconcelos, Andreanne Gomes; Comerma-Steffensen, Simón Gabriel

    2015-01-01

    Proline-rich oligopeptides (PROs) are a large family which comprises the bradykinin-potentiating peptides (BPPs). They inhibit the activity of the angiotensin I-converting enzyme (ACE) and have a typical pyroglutamyl (Pyr)/proline-rich structure at the N- and C-terminus, respectively. Furthermore......, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated...... form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C...

  5. Salivary proline-rich protein may reduce tannin-iron chelation: a systematic narrative review

    OpenAIRE

    Delimont, Nicole M.; Rosenkranz, Sara K.; Haub, Mark D.; Lindshield, Brian L.

    2017-01-01

    Background Tannins are often cited for antinutritional effects, including chelation of non-heme iron. Despite this, studies exploring non-heme iron bioavailability inhibition with long-term consumption have reported mixed results. Salivary proline-rich proteins (PRPs) may mediate tannin-antinutritional effects on non-heme iron bioavailability. Aim To review evidence regarding biochemical binding mechanisms and affinity states between PRPs and tannins, as well as effects of PRPs on non-heme ir...

  6. Characterization of the cell penetrating properties of a human salivary proline-rich peptide.

    Science.gov (United States)

    Radicioni, Giorgia; Stringaro, Annarita; Molinari, Agnese; Nocca, Giuseppina; Longhi, Renato; Pirolli, Davide; Scarano, Emanuele; Iavarone, Federica; Manconi, Barbara; Cabras, Tiziana; Messana, Irene; Castagnola, Massimo; Vitali, Alberto

    2015-11-01

    Saliva contains hundreds of small proline-rich peptides most of which derive from the post-translational and post-secretory processing of the acidic and basic salivary proline-rich proteins. Among these peptides we found that a 20 residue proline-rich peptide (p1932), commonly present in human saliva and patented for its antiviral activity, was internalized within cells of the oral mucosa. The cell-penetrating properties of p1932 have been studied in a primary gingival fibroblast cell line and in a squamous cancer cell line, and compared to its retro-inverso form. We observed by mass-spectrometry, flow cytometry and confocal microscopy that both peptides were internalized in the two cell lines on a time scale of minutes, being the natural form more efficient than the retro-inverso one. The cytosolic localization was dependent on the cell type: both peptide forms were able to localize within nuclei of tumoral cells, but not in the nuclei of gingival fibroblasts. The uptake was shown to be dependent on the culture conditions used: peptide internalization was indeed effective in a complete medium than in a serum-free one allowing the hypothesis that the internalization could be dependent on the cell cycle. Both peptides were internalized likely by a lipid raft-mediated endocytosis mechanism as suggested by the reduced uptake in the presence of methyl-ß-cyclodextrin. These results suggest that the natural peptide may play a role within the cells of the oral mucosa after its secretion and subsequent internalization. Furthermore, lack of cytotoxicity of both peptide forms highlights their possible application as novel drug delivery agents.

  7. First evidences of interaction between pyranoanthocyanins and salivary proline-rich proteins.

    Science.gov (United States)

    García-Estévez, Ignacio; Cruz, Luís; Oliveira, Joana; Mateus, Nuno; de Freitas, Victor; Soares, Susana

    2017-08-01

    The contribution of other classes of polyphenol compounds besides tannins to the overall perception of astringency is still poorly understood. So, this work aimed to study the interaction between a family of salivary proline-rich proteins (aPRPs) and representative pyranoanthocyanins in red wines [pyranomalvidin-3-glucoside (vitisin B), pyranomalvidin-3-glucoside-catechol, and pyranomalvidin-3-glucoside-epicatechin] using saturation transfer difference-NMR and MALDI-TOF. For vitisin B K D was of 1.74mM; for pyranomalvidin-3-glucoside-catechol was 1.17mM and for pyranomalvidin-3-glucoside-epicatechin it was 0.87mM. The presence of the flavanol structural unit in the pyranoanthocyanins led to an increase in their interaction with aPRPs. Further, it is also interesting that the values obtained were in the range of K D obtained previously reported for the interaction between the human saliva proline-rich peptides (IB7 14 and IB9 37 ) and procyanidins. Overall, the results obtained suggest that, along with tannins, other polyphenols present in red wine, namely pyranoanthocyanins, could actively contribute to red wine global astringency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Natural Proline-Rich Cyclopolypeptides from Marine Organisms: Chemistry, Synthetic Methodologies and Biological Status.

    Science.gov (United States)

    Fang, Wan-Yin; Dahiya, Rajiv; Qin, Hua-Li; Mourya, Rita; Maharaj, Sandeep

    2016-10-26

    Peptides have gained increased interest as therapeutics during recent years. More than 60 peptide drugs have reached the market for the benefit of patients and several hundreds of novel therapeutic peptides are in preclinical and clinical development. The key contributor to this success is the potent and specific, yet safe, mode of action of peptides. Among the wide range of biologically-active peptides, naturally-occurring marine-derived cyclopolypeptides exhibit a broad range of unusual and potent pharmacological activities. Because of their size and complexity, proline-rich cyclic peptides (PRCPs) occupy a crucial chemical space in drug discovery that may provide useful scaffolds for modulating more challenging biological targets, such as protein-protein interactions and allosteric binding sites. Diverse pharmacological activities of natural cyclic peptides from marine sponges, tunicates and cyanobacteria have encouraged efforts to develop cyclic peptides with well-known synthetic methods, including solid-phase and solution-phase techniques of peptide synthesis. The present review highlights the natural resources, unique structural features and the most relevant biological properties of proline-rich peptides of marine-origin, focusing on the potential therapeutic role that the PRCPs may play as a promising source of new peptide-based novel drugs.

  9. PCR Assays for Identification of Coccidioides posadasii Based on the Nucleotide Sequence of the Antigen 2/Proline-Rich Antigen

    Science.gov (United States)

    Bialek, Ralf; Kern, Jan; Herrmann, Tanja; Tijerina, Rolando; Ceceñas, Luis; Reischl, Udo; González, Gloria M.

    2004-01-01

    A conventional nested PCR and a real-time LightCycler PCR assay for detection of Coccidioides posadasii DNA were designed and tested in 120 clinical strains. These had been isolated from 114 patients within 10 years in Monterrey, Nuevo Leon, Mexico, known to be endemic for coccidioidomycosis. The gene encoding the specific antigen 2/proline-rich antigen (Ag2/PRA) was used as a target. All strains were correctly identified, whereas DNA from related members of the family Onygenaceae remained negative. Melting curve analysis by LightCycler and sequencing of the 526-bp product of the first PCR demonstrated either 100% identity to the GenBank sequence of the Silveira strain, now known to be C. posadasii (accession number AF013256), or a single silent mutation at position 1228. Length determination of two microsatellite-containing loci (GAC and 621) identified all 120 isolates as C. posadasii. Specific DNA was amplified by conventional nested PCR from three microscopically spherule-positive paraffin-embedded tissue samples, whereas 20 human tissue samples positive for other dimorphic fungi remained negative. Additionally, the safety of each step of a modified commercially available DNA extraction procedure was evaluated by using 10 strains. At least three steps of the protocol were demonstrated to sufficiently kill arthroconidia. This safe procedure is applicable to cultures and to clinical specimens. PMID:14766853

  10. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium.

    Science.gov (United States)

    Arcanjo, Daniel Dias Rufino; Vasconcelos, Andreanne Gomes; Comerma-Steffensen, Simón Gabriel; Jesus, Joilson Ramos; Silva, Luciano Paulino; Pires Júnior, Osmindo Rodrigues; Costa-Neto, Claudio Miguel; Oliveira, Eduardo Brandt; Migliolo, Ludovico; Franco, Octávio Luiz; Restini, Carolina Baraldi Araújo; Paulo, Michele; Bendhack, Lusiane Maria; Bemquerer, Marcelo Porto; Oliveira, Aldeidia Pereira; Simonsen, Ulf; Leite, José Roberto de Souza de Almeida

    2015-01-01

    Proline-rich oligopeptides (PROs) are a large family which comprises the bradykinin-potentiating peptides (BPPs). They inhibit the activity of the angiotensin I-converting enzyme (ACE) and have a typical pyroglutamyl (Pyr)/proline-rich structure at the N- and C-terminus, respectively. Furthermore, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C-domain active site. Moreover, in rat thoracic aorta BPP-BrachyNH2 induces potent endothelium-dependent vasodilatation with similar magnitude as captopril. In DAF-FM DA-loaded aortic cross sections examined by confocal microscopy, BPP-BrachyNH2 was found to increase the release of nitric oxide (NO). Moreover, BPP-BrachyNH2 was devoid of toxicity in endothelial and smooth muscle cell cultures. In conclusion, the peptide BPP-BrachyNH2 has a novel sequence being the first BPP isolated from the skin secretion of the Brachycephalidae family. This opens for exploring amphibians as a source of new biomolecules. The BPP-BrachyNH2 is devoid of cytotoxicity and elicits endothelium-dependent vasodilatation mediated by NO. These findings open for the possibility of potential application of these peptides in the treatment of endothelial dysfunction and cardiovascular diseases.

  11. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium.

    Directory of Open Access Journals (Sweden)

    Daniel Dias Rufino Arcanjo

    Full Text Available Proline-rich oligopeptides (PROs are a large family which comprises the bradykinin-potentiating peptides (BPPs. They inhibit the activity of the angiotensin I-converting enzyme (ACE and have a typical pyroglutamyl (Pyr/proline-rich structure at the N- and C-terminus, respectively. Furthermore, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C-domain active site. Moreover, in rat thoracic aorta BPP-BrachyNH2 induces potent endothelium-dependent vasodilatation with similar magnitude as captopril. In DAF-FM DA-loaded aortic cross sections examined by confocal microscopy, BPP-BrachyNH2 was found to increase the release of nitric oxide (NO. Moreover, BPP-BrachyNH2 was devoid of toxicity in endothelial and smooth muscle cell cultures. In conclusion, the peptide BPP-BrachyNH2 has a novel sequence being the first BPP isolated from the skin secretion of the Brachycephalidae family. This opens for exploring amphibians as a source of new biomolecules. The BPP-BrachyNH2 is devoid of cytotoxicity and elicits endothelium-dependent vasodilatation mediated by NO. These findings open for the possibility of potential application of these peptides in the treatment of endothelial dysfunction and cardiovascular diseases.

  12. The Tomato Hybrid Proline-Rich Protein regulates the abcission zone competence to respond to ethylene signals

    Science.gov (United States)

    The Tomato Hybrid Proline-Rich Protein (THyPRP) gene was specifically expressed in the tomato (Solanum lycopersicum) flower abscission zone (FAZ), and its stable antisense silencing under the control of an abscission zone (AZ)-specific promoter, Tomato Abscission Polygalacturonase4,significantly inh...

  13. New proline-rich oligopeptides from the venom of African adders: Insights into the hypotensive effect of the venoms.

    Science.gov (United States)

    Kodama, Roberto T; Cajado-Carvalho, Daniela; Kuniyoshi, Alexandre K; Kitano, Eduardo S; Tashima, Alexandre K; Barna, Barbara F; Takakura, Ana Carolina; Serrano, Solange M T; Dias-Da-Silva, Wilmar; Tambourgi, Denise V; Portaro, Fernanda V

    2015-06-01

    The snakes from the Bitis genus are some of the most medically important venomous snakes in sub Saharan Africa, however little is known about the composition and effects of these snake venom peptides. Considering that the victims with Bitis genus snakes have exacerbate hypotension and cardiovascular disorders, we investigated here the presence of angiotensin-converting enzyme modulators on four different species of venoms. The peptide fractions from Bitis gabonica gabonica, Bitis nasicornis, Bitis gabonica rhinoceros and Bitis arietans which showed inhibitory activity on angiotensin-converting enzyme were subjected to mass spectrometry analysis. Eight proline-rich peptides were synthetized and their potencies were evaluated in vitro and in vivo. The MS analysis resulted in over 150 sequences, out of which 32 are new proline-rich oligopeptides, and eight were selected for syntheses. For some peptides, inhibition assays showed inhibitory potentials of cleavage of angiotensin I ten times greater when compared to bradykinin. In vivo tests showed that all peptides decreased mean arterial pressure, followed by tachycardia in 6 out of 8 of the tests. We describe here some new and already known proline-rich peptides, also known as bradykinin-potentiating peptides. Four synthetic peptides indicated a preferential inhibition of angiotensin-converting enzyme C-domain. In vivo studies show that the proline-rich oligopeptides are hypotensive molecules. Although proline-rich oligopeptides are known molecules, we present here 32 new sequences that are inhibitors of the angiotensin-converting enzyme and consistent with the symptoms of the victims of Bitis spp, who display severe hypotension. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Study of human salivary proline-rich proteins interaction with food tannins.

    Science.gov (United States)

    Soares, Susana; García-Estévez, Ignacio; Ferrer-Galego, Raúl; Brás, Natércia F; Brandão, Elsa; Silva, Mafalda; Teixeira, Natércia; Fonseca, Fátima; Sousa, Sérgio F; Ferreira-da-Silva, Frederico; Mateus, Nuno; de Freitas, Victor

    2018-03-15

    In this work, saturation transfer difference-NMR, isothermal microcalorimetry and molecular dynamics simulations have been used to study the individual interactions between basic, glycosylated and acidic proline-rich proteins (bPRPS, gPRPs, aPRPs) and P-B peptide with some representative food tannins [procyanidin B2, procyanidin B2 3'-O-gallate (B2g) and procyanidin trimer (catechin-4-8-catechin-4-8-catechin)]. Results showed that P-B peptide was in general the salivary protein (SP) with higher affinity whereas aPRPs showed lower affinity to the studied procyanidins. Moreover, B2g was the procyanidin with higher affinity for all SP. Hydrophobic and hydrogen bonds were present in all interactions but the major driving force depended on the procyanidin-SP pair. Furthermore, proline clusters or residues in their vicinity were identified as the probable sites of proteins for interaction with procyanidins. For bPRP and aPRP a significant change to less extended conformations was observed, while P-B peptide did not display any structural rearrangement upon procyanidins binding. Copyright © 2017. Published by Elsevier Ltd.

  15. Hybrid proline-rich proteins: novel players in plant cell elongation?

    Science.gov (United States)

    Dvořáková, Lenka; Srba, Miroslav; Opatrny, Zdenek; Fischer, Lukas

    2012-01-01

    Background and Aims Hybrid proline-rich proteins (HyPRPs) represent a large family of putative cell-wall proteins characterized by the presence of a variable N-terminal domain and a conserved C-terminal domain that is related to non-specific lipid transfer proteins. The function of HyPRPs remains unclear, but their widespread occurrence and abundant expression patterns indicate that they may be involved in a basic cellular process. Methods To elucidate the cellular function of HyPRPs, we modulated the expression of three HyPRP genes in tobacco (Nicotiana tabacum) BY-2 cell lines and in potato (Solanum tuberosum) plants. Key Results In BY-2 lines, over-expression of the three HyPRP genes with different types of N-terminal domains resulted in similar phenotypic changes, namely increased cell elongation, both in suspension culture and on solid media where the over-expression resulted in enhanced calli size. The over-expressing cells showed increased plasmolysis in a hypertonic mannitol solution and accelerated rate of protoplast release, suggesting loosening of the cell walls. In contrast to BY-2 lines, no phenotypic changes were observed in potato plants over-expressing the same or analogous HyPRP genes, presumably due to more complex compensatory mechanisms in planta. Conclusions Based on the results from BY-2 lines, we propose that HyPRPs, more specifically their C-terminal domains, represent a novel group of proteins involved in cell expansion. PMID:22028464

  16. Structural landscape of the proline-rich domain of Sos1 nucleotide exchange factor.

    Science.gov (United States)

    McDonald, Caleb B; Bhat, Vikas; Kurouski, Dmitry; Mikles, David C; Deegan, Brian J; Seldeen, Kenneth L; Lednev, Igor K; Farooq, Amjad

    2013-01-01

    Despite its key role in mediating a plethora of cellular signaling cascades pertinent to health and disease, little is known about the structural landscape of the proline-rich (PR) domain of Sos1 guanine nucleotide exchange factor. Herein, using a battery of biophysical tools, we provide evidence that the PR domain of Sos1 is structurally disordered and adopts an extended random coil-like conformation in solution. Of particular interest is the observation that while chemical denaturation of PR domain results in the formation of a significant amount of polyproline II (PPII) helices, it has little or negligible effect on its overall size as measured by its hydrodynamic radius. Our data also show that the PR domain displays a highly dynamic conformational basin in agreement with the knowledge that the intrinsically unstructured proteins rapidly interconvert between an ensemble of conformations. Collectively, our study provides new insights into the conformational equilibrium of a key signaling molecule with important consequences on its physiological function. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Analysis of the thermodynamics of binding of an SH3 domain to proline-rich peptides using a chimeric fusion protein.

    Science.gov (United States)

    Candel, Adela M; van Nuland, Nico A J; Martin-Sierra, Francisco M; Martinez, Jose C; Conejero-Lara, Francisco

    2008-03-14

    A complete understanding of the thermodynamic determinants of binding between SH3 domains and proline-rich peptides is crucial to the development of rational strategies for designing ligands for these important domains. Recently we engineered a single-chain chimeric protein by fusing the alpha-spectrin Src homology region 3 (SH3) domain to the decapeptide APSYSPPPPP (p41). This chimera mimics the structural and energetic features of the interaction between SH3 domains and proline-rich peptides. Here we show that analysing the unfolding thermodynamics of single-point mutants of this chimeric fusion protein constitutes a very useful approach to deciphering the thermodynamics of SH3-ligand interactions. To this end, we investigated the contribution of each proline residue of the ligand sequence to the SH3-peptide interaction by producing six single Pro-Ala mutants of the chimeric protein and analysing their unfolding thermodynamics by differential scanning calorimetry (DSC). Structural analyses of the mutant chimeras by circular dichroism, fluorescence and NMR together with NMR-relaxation measurements indicate conformational flexibility at the binding interface, which is strongly affected by the different Pro-Ala mutations. An analysis of the DSC thermograms on the basis of a three-state unfolding model has allowed us to distinguish and separate the thermodynamic magnitudes of the interaction at the binding interface. The model assumes equilibrium between the "unbound" and "bound" states at the SH3-peptide binding interface. The resulting thermodynamic magnitudes classify the different proline residues according to their importance in the interaction as P2 approximately P7 approximately P10>P9 approximately P6>P8, which agrees well with Lim's model for the interaction between SH3 domains and proline-rich peptides. In addition, the thermodynamic signature of the interaction is the same as that usually found for this type of binding, with a strong enthalpy

  18. Effect of proline rich 15-deficiency on trophoblast viability and survival.

    Directory of Open Access Journals (Sweden)

    Katherine C Gates

    Full Text Available Deviations from the normal program of gene expression during early pregnancy can lead to early embryonic loss as well as dysfunctional placentation, which can cause significant morbidity and mortality. Proline rich 15 (PRR15 is a low molecular weight nuclear protein expressed by the trophoblast during early gestation. Lentivirus-mediated knockdown of PRR15 mRNA in ovine trophectoderm led to demise of the embryo by gestational day 15, providing compelling evidence that PRR15 expression is critical during this precarious window of development. Our objective was to determine the effect of PRR15 knockdown on trophoblast gene expression, proliferation, and survival. The first-trimester human trophoblast cell line, ACH-3P, was infected with control lentivirus or a lentivirus expressing a short hairpin (shRNA to target PRR15 mRNA for degradation, resulting in a 68% reduction in PRR15 mRNA. Microarray analysis of these cell lines revealed differential expression of genes related to cancer, focal adhesion, and p53 signaling. These changes included significant up-regulation of GDF15, a cytokine increased in pregnancies with preeclampsia. Viability and proliferation decreased in PRR15-deficient cells, which was consistent with down-regulation of cell cycle-related genes CCND1 and CDK6 and an up-regulation of CCNG2 and CDKN1A in the PRR15-deficient cells. TNFSF10, a tumor necrosis factor superfamily member known to induce apoptosis increased significantly in the PRR15-deficient cells. Migration through a basement membrane matrix decreased and an increased population of apoptotic cells was present when treated with shRNA to target PRR15. These results suggest that PRR15 enhances trophoblast viability and survival during early implantation and placentation.

  19. Location and nature of calcium-binding sites in salivary acidic proline-rich phosphoproteins

    International Nuclear Information System (INIS)

    Bennick, A.; McLaughlin, A.C.; Grey, A.A.; Madapallimattam, G.

    1981-01-01

    The location of the calcium-binding sites in the human acidic proline-rich proteins, salivary proteins A and C, was determined by equilibrium dialysis of the tryptic peptides with buffers containing 45 Ca. All the calcium-binding sites are located in the NH 2 -terminal tryptic peptide (TX peptide). The nature of the calcium binding sites in the TX peptide and native salivary proteins A and C, as well as dephosphorylated proteins was compared. Two types of sites can be distinguished in peptide TX. Type I sites have an apparent dissociation constant (K) of 38 μM and are responsible for the binding of 2.6 mol of Ca/mol of peptide. The corresponding figures for Type II sites are 780 μM and 5.3 mol of Ca/mol of peptide. In the native proteins, the amount of calcium bound at the type II sites decreases to 3.9 mol of Ca/mol of proteins A and C and K increases to 1100 μM. The amount of calcium bound at type I sites decreases to 1.5 mol/mol of protein A and 0.6 mol/mol of protein C, but there is no change in K. Dephosphorylation affects the calcium binding at both types of sites. The experiments indicate that the COOH-terminal parts of the native proteins affect the number and the nature of the protein calcium-binding sites. Proton and phosphorous NMR data demonstrate that β-COOH in aspartic acid, as well as phosphoserine, are part of the calcium-binding sites. The difference in calcium binding to salivary proteins A and C may be due at least partially to differences in the environment of one or more aspartic acids

  20. Lacrimal proline rich 4 (LPRR4 protein in the tear fluid is a potential biomarker of dry eye syndrome.

    Directory of Open Access Journals (Sweden)

    Saijyothi Venkata Aluru

    Full Text Available Dry eye syndrome (DES is a complex, multifactorial, immune-associated disorder of the tear and ocular surface. DES with a high prevalence world over needs identification of potential biomarkers so as to understand not only the disease mechanism but also to identify drug targets. In this study we looked for differentially expressed proteins in tear samples of DES to arrive at characteristic biomarkers. As part of a prospective case-control study, tear specimen were collected using Schirmer strips from 129 dry eye cases and 73 age matched controls. 2D electrophoresis (2DE and Differential gel electrophoresis (DIGE was done to identify differentially expressed proteins. One of the differentially expressed protein in DES is lacrimal proline rich 4 protein (LPRR4. LPRR4 protein expression was quantified by enzyme immune sorbent assay (ELISA. LPRR4 was down regulated significantly in all types of dry eye cases, correlating with the disease severity as measured by clinical investigations. Further characterization of the protein is required to assess its therapeutic potential in DES.

  1. Protective Effects of Proline-Rich Peptide in a Rat Model of Alzheimer Disease: An Electrophysiological Study.

    Science.gov (United States)

    Khalaji, Naser; Sarkissian, John; Chavushyan, Vergine; Sarkisian, Vaghinak

    2017-01-01

    Alzheimer disease (AD) is the most common form of dementia in the elderly that slowly destroys memory and cognitive functions. The disease has no cure and leads to significant structural and functional brain abnormalities. To facilitate the treatment of this disease, we aimed to investigate proline-rich peptide (PRP-1) action of hypothalamus on hippocampal (HP) neurons and dynamics of their recovery, after intracerebroventricular (ICV) injection of amyloid-β (Aβ). Experiments were carried out on 24 adult, male Albino rats (average weight: 230±30 g). The animals were randomly divided into 3 groups (control, Aβ, and Aβ plus PRP-1). Electrophysiological patterns of hippocampal neurons in response to stimulation of entorhinal cortex (EC) with high frequency stimulation (50 Hz) were studied. It was found that Aβ (25-35) suppresses the electrical activity of hippocampal neurons. The PRP-1 would return this activity to normal levels. In general, PRP-1 has protective effect against AD-related alterations induced by amyloid peptides. This protective effect is probably due to stimulation of the immune and glia system.

  2. Tissue distribution in mice of BPP 10c, a potent proline-rich anti-hypertensive peptide of Bothrops jararaca.

    Science.gov (United States)

    Silva, Carlos A; Portaro, Fernanda C V; Fernandes, Beatriz L; Ianzer, Danielle A; Guerreiro, Juliano R; Gomes, Claudiana L; Konno, Katsuhiro; Serrano, Solange M T; Nascimento, Nanci; Camargo, Antonio C M

    2008-03-15

    The snake venom proline-rich peptide BPP 10c is an active somatic angiotensin-converting enzyme (sACE) inhibitors. Recently we demonstrated that the anti-hypertensive effect of BPP 10c is not related to the inhibition of sACE alone, thus suggesting that this enzyme is not its only target for blood pressure reduction. In the present work, a biodistribution study in Swiss mice of [(125)I]-BPP 10c in the absence or in the presence of a saturating concentration of captopril, a selective active-site inhibitor of sACE, demonstrated that: (1) [(125)I]-BPP 10c was present in several organs and the renal absorption was significantly high; (2) [(125)I]-BPP 10c showed a clear preference for the kidney, maintaining a high concentration in this organ in the presence of captopril for at least 3h; (3) The residual amount of [(125)I]-BPP 10c in the kidney of animals simultaneously treated with captopril suggest that the peptide can interact with other targets different from sACE in this organ. We also showed that Cy3-labeled BPP 10c was internalized by human embryonic kidney cells (HEK-293T). Taken together, these results suggest that sACE inhibition by captopril affects the tissue distribution of [(125)I]-BPP 10c and that the anti-hypertensive effects of BPP 10c are not only dependent on sACE inhibition.

  3. Disruption of Fyn SH3 domain interaction with a proline-rich motif in liver kinase B1 results in activation of AMP-activated protein kinase.

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    Eijiro Yamada

    Full Text Available Fyn-deficient mice display increased AMP-activated Protein Kinase (AMPK activity as a result of Fyn-dependent regulation of Liver Kinase B1 (LKB1 in skeletal muscle. Mutation of Fyn-specific tyrosine sites in LKB1 results in LKB1 export into the cytoplasm and increased AMPK activation site phosphorylation. This study characterizes the structural elements responsible for the physical interaction between Fyn and LKB1. Effects of point mutations in the Fyn SH2/SH3 domains and in the LKB1 proline-rich motif on 1 Fyn and LKB1 binding, 2 LKB1 subcellular localization and 3 AMPK phosphorylation were investigated in C2C12 muscle cells. Additionally, novel LKB1 proline-rich motif mimicking cell permeable peptides were generated to disrupt Fyn/LKB1 binding and investigate the consequences on AMPK activity in both C2C12 cells and mouse skeletal muscle. Mutation of either Fyn SH3 domain or the proline-rich motif of LKB1 resulted in the disruption of Fyn/LKB1 binding, re-localization of 70% of LKB1 signal in the cytoplasm and a 2-fold increase in AMPK phosphorylation. In vivo disruption of the Fyn/LKB1 interaction using LKB1 proline-rich motif mimicking cell permeable peptides recapitulated Fyn pharmacological inhibition. We have pinpointed the structural elements within Fyn and LKB1 that are responsible for their binding, demonstrating the functionality of this interaction in regulating AMPK activity.

  4. Isolation and characterization of the messenger RNA and the gene coding for a proline-rich zein from corn endosperm

    International Nuclear Information System (INIS)

    Wang, S.Z.

    1985-01-01

    Gamma-zein, a proline-rich protein from corn endosperm, was investigated at the molecular level. Immunological and electrophoretic data indicated that gamma-zein was deposited into protein bodies in corn endosperm. Both isolated polysomes and poly(A) + mRNA were found to direct into vitro synthesis of gamma-zein in a wheat germ system. In vitro synthesized gamma-zein was immunoprecipitated from the total in vitro translation products. A cDNA expression library was constructed by reverse transcription of total poly(A) + mRNA using pUC8 plasmid as vector and E. coli strain DH1 as host. The library was screened for the expression of gamma-zein and alpha-zein by specific antibodies. The library was also screened with 32 P-labeled gamma-zein and alpha-zein cDNA probes. The results indicated that gamma-zein and its fragments were readily expressed in E. coli while alpha-zein was not. Seven independently selected clones, six of which were selected by antibody and one by a cDNA probe, were sequenced. A comparison of sequence information from seven clones revealed that their overlapping regions were identical. This suggests that gamma-zein is encoded by a single gene. This finding is in conflict with what was expected on the basis of extensive charge heterogeneity of gamma-zein in isoelectric focusing. Individual bands cut from an IEF gel were rerun and shown to give several bands suggesting that the charge heterogeneity of gamma-zein may be an artifact. Sequence information of gamma-zein indicated that the gene encodes a mature protein whose primary structure includes 204 amino acids and has a molecular weight of 21,824 daltons

  5. Design, Synthesis, and Antibacterial Activities of Novel Heterocyclic Arylsulphonamide Derivatives.

    Science.gov (United States)

    Singh, Anuradha; Srivastava, Ritika; Singh, Ramendra K

    2017-02-13

    Design, synthesis, and antibacterial activities of a series of arylsulphonamide derivatives as probable peptide deformylase (PDF) inhibitors have been discussed. Compounds have been designed following Lipinski's rule and after docking into the active site of PDF protein (PDB code: 1G2A) synthesized later on. Furthermore, to assess their antibacterial activity, screening of the compound was done in vitro conditions against Gram-positive and Gram-negative bacterial strains. In silico, studies revealed these compounds as potential antibacterial agents and this fact was also supported by their prominent scoring functions. Antibacterial results indicated that these molecules possessed a significant activity against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli with MIC values ranging from 0.06 to 0.29 μM. TOPKAT results showed that high LD 50 values and the compounds were assumed non-carcinogenic when various animal models were studied computationally.

  6. A Proline-Rich N-Terminal Region of the Dengue Virus NS3 Is Crucial for Infectious Particle Production.

    Science.gov (United States)

    Gebhard, Leopoldo G; Iglesias, Néstor G; Byk, Laura A; Filomatori, Claudia V; De Maio, Federico A; Gamarnik, Andrea V

    2016-06-01

    Dengue virus is currently the most important insect-borne viral human pathogen. Viral nonstructural protein 3 (NS3) is a key component of the viral replication machinery that performs multiple functions during viral replication and participates in antiviral evasion. Using dengue virus infectious clones and reporter systems to dissect each step of the viral life cycle, we examined the requirements of different domains of NS3 on viral particle assembly. A thorough site-directed mutagenesis study based on solvent-accessible surface areas of NS3 revealed that, in addition to being essential for RNA replication, different domains of dengue virus NS3 are critically required for production of infectious viral particles. Unexpectedly, point mutations in the protease, interdomain linker, or helicase domain were sufficient to abolish infectious particle formation without affecting translation, polyprotein processing, or RNA replication. In particular, we identified a novel proline-rich N-terminal unstructured region of NS3 that contains several amino acid residues involved in infectious particle formation. We also showed a new role for the interdomain linker of NS3 in virion assembly. In conclusion, we present a comprehensive genetic map of novel NS3 determinants for viral particle assembly. Importantly, our results provide evidence of a central role of NS3 in the coordination of both dengue virus RNA replication and particle formation. Dengue virus is an important human pathogen, and its prominence is expanding globally; however, basic aspects of its biology are still unclear, hindering the development of effective therapeutic and prophylactic treatments. Little is known about the initial steps of dengue and other flavivirus particle assembly. This process involves a complex interplay between viral and cellular components, making it an attractive antiviral target. Unpredictably, we identified spatially separated regions of the large NS3 viral protein as determinants for

  7. Design of New Antibacterial Enhancers Based on AcrB’s Structure and the Evaluation of Their Antibacterial Enhancement Activity

    Directory of Open Access Journals (Sweden)

    Yi Song

    2016-11-01

    Full Text Available Previously, artesunate (AS and dihydroartemisinine 7 (DHA7 were found to have antibacterial enhancement activity against Escherichia coli via inhibition of the efflux pump AcrB. However, they were only effective against E. coli standard strains. This study aimed to develop effective antibacterial enhancers based on the previous work. Our results demonstrate that 86 new antibacterial enhancers were designed via 3D-SAR and molecular docking. Among them, DHA27 had the best antibacterial enhancement activity. It could potentiate the antibacterial effects of ampicillin against not only E. coli standard strain but also clinical strains, and of β-lactam antibiotics, not non-β-lactamantibiotics. DHA27 could increase the accumulation of daunomycin and nile red within E. coli ATCC 35218, but did not increase the bacterial membrane permeability. DHA27 reduced acrB’s mRNA expression of E. coli ATCC 35218 in a dose-dependent manner, and its antibacterial enhancement activity is related to the degree of acrB mRNA expression in E. coli clinical strains. The polypeptides from AcrB were obtained via molecular docking assay; the pre-incubated polypeptides could inhibit the activity of DHA27. Importantly, DHA27 had no cytotoxicity on cell proliferation. In conclusion, among newly designed antibacterial enhancers, DHA27 had favorable physical and pharmacological properties with no significant cytotoxicity at effective concentrations, and might serve as a potential efflux pump inhibitor in the future.

  8. Production and characterization of two major Aspergillus oryzae secreted prolyl endopeptidases able to efficiently digest proline-rich peptides of gliadin.

    Science.gov (United States)

    Eugster, Philippe J; Salamin, Karine; Grouzmann, Eric; Monod, Michel

    2015-12-01

    Prolyl endopeptidases are key enzymes in the digestion of proline-rich proteins. Fungal extracts rich in prolyl endopeptidases produced by a species such as Aspergillus oryzae used in food fermentation would be of particular interest for the development of an oral enzyme therapy product in patients affected by intolerance to gluten. Two major A. oryzae secreted prolyl endopeptidases of the MEROPS S28 peptidase family, AoS28A and AoS28B, were identified when this fungus was grown at acidic pH in a medium containing soy meal protein or wheat gliadin as the sole source of nitrogen. AoS28B was produced by 12 reference A. oryzae strains used in food fermentation. AoS28A was secreted by six of these 12 strains. This protease is the orthologue of the previously characterized Aspergillus fumigatus (AfuS28) and Aspergillus niger (AN-PEP) prolyl endopeptidases which are encoded by genes with a similar intron-exon structure. Large amounts of secreted AoS28A and AoS28B were obtained by gene overexpression in A. oryzae. AoS28A and AoS28B are endoproteases able to cleave N-terminally blocked proline substrates. Both enzymes very efficiently digested the proline-rich 33-mer of gliadin, the most representative immunotoxic peptide deriving from gliadin, with some differences in terms of specificity and optimal pH. Digestion of the gliadin peptide in short peptides with both enzymes was found to occur from its N terminus.

  9. Designing Antibacterial Peptides with Enhanced Killing Kinetics

    Directory of Open Access Journals (Sweden)

    Faiza H. Waghu

    2018-02-01

    Full Text Available Antimicrobial peptides (AMPs are gaining attention as substitutes for antibiotics in order to combat the risk posed by multi-drug resistant pathogens. Several research groups are engaged in design of potent anti-infective agents using natural AMPs as templates. In this study, a library of peptides with high sequence similarity to Myeloid Antimicrobial Peptide (MAP family were screened using popular online prediction algorithms. These peptide variants were designed in a manner to retain the conserved residues within the MAP family. The prediction algorithms were found to effectively classify peptides based on their antimicrobial nature. In order to improve the activity of the identified peptides, molecular dynamics (MD simulations, using bilayer and micellar systems could be used to design and predict effect of residue substitution on membranes of microbial and mammalian cells. The inference from MD simulation studies well corroborated with the wet-lab observations indicating that MD-guided rational design could lead to discovery of potent AMPs. The effect of the residue substitution on membrane activity was studied in greater detail using killing kinetic analysis. Killing kinetics studies on Gram-positive, negative and human erythrocytes indicated that a single residue change has a drastic effect on the potency of AMPs. An interesting outcome was a switch from monophasic to biphasic death rate constant of Staphylococcus aureus due to a single residue mutation in the peptide.

  10. The colloidal state of tannins impacts the nature of their interaction with proteins: the case of salivary proline-rich protein/procyanidins binding.

    Science.gov (United States)

    Cala, Olivier; Dufourc, Erick J; Fouquet, Eric; Manigand, Claude; Laguerre, Michel; Pianet, Isabelle

    2012-12-18

    While the definition of tannins has been historically associated with its propensity to bind proteins in a nonspecific way, it is now admitted that specific interaction also occurs. The case of the astringency perception is a good example to illustrate this phenomenon: astringency is commonly described as a tactile sensation induced by the precipitation of a complex composed of proline-rich proteins present in the human saliva and tannins present in beverages such as tea or red wines. In the present work, the interactions between a human saliva protein segment and three different procyanidins (B1, B3, and C2) were investigated at the atomic level by NMR and molecular dynamics. The data provided evidence for (i) an increase in affinity compared to shortest human saliva peptides, which is accounted for by protein "wraping around" the tannin, (ii) a specificity in the interaction below tannin critical micelle concentration (CMC) of ca. 10 mM, with an affinity scale such that C2 > B1 > B3, and (iii) a nonspecific binding above tannin CMC that conducts irremediably to the precipitation of the tannins/protein complex. Such physicochemical findings describe in accurate terms saliva protein-tannin interactions and provide support for a more subtle description by oenologists of wine astringency perception in the mouth.

  11. Structure-activity relationships of the antimicrobial peptide arasin 1 - and mode of action studies of the N-terminal, proline-rich region.

    Directory of Open Access Journals (Sweden)

    Victoria S Paulsen

    Full Text Available Arasin 1 is a 37 amino acid long proline-rich antimicrobial peptide isolated from the spider crab, Hyas araneus. In this work the active region of arasin 1 was identified through structure-activity studies using different peptide fragments derived from the arasin 1 sequence. The pharmacophore was found to be located in the proline/arginine-rich NH(2 terminus of the peptide and the fragment arasin 1(1-23 was almost equally active to the full length peptide. Arasin 1 and its active fragment arasin 1(1-23 were shown to be non-toxic to human red blood cells and arasin 1(1-23 was able to bind chitin, a component of fungal cell walls and the crustacean shell. The mode of action of the fully active N-terminal arasin 1(1-23 was explored through killing kinetic and membrane permeabilization studies. At the minimal inhibitory concentration (MIC, arasin 1(1-23 was not bactericidal and had no membrane disruptive effect. In contrast, at concentrations of 5×MIC and above it was bactericidal and interfered with membrane integrity. We conclude that arasin 1(1-23 has a different mode of action than lytic peptides, like cecropin P1. Thus, we suggest a dual mode of action for arasin 1(1-23 involving membrane disruption at peptide concentrations above MIC, and an alternative mechanism of action, possibly involving intracellular targets, at MIC.

  12. Toll like receptors TLR1/2, TLR6 and MUC5B as binding interaction partners with cytostatic proline rich polypeptide 1 in human chondrosarcoma.

    Science.gov (United States)

    Galoian, Karina; Abrahamyan, Silva; Chailyan, Gor; Qureshi, Amir; Patel, Parthik; Metser, Gil; Moran, Alexandra; Sahakyan, Inesa; Tumasyan, Narine; Lee, Albert; Davtyan, Tigran; Chailyan, Samvel; Galoyan, Armen

    2018-01-01

    Metastatic chondrosarcoma is a bone malignancy not responsive to conventional therapies; new approaches and therapies are urgently needed. We have previously reported that mTORC1 inhibitor, antitumorigenic cytostatic proline rich polypeptide 1 (PRP-1), galarmin caused a significant upregulation of tumor suppressors including TET1/2 and SOCS3 (known to be involved in inflammatory processes), downregulation of oncoproteins and embryonic stem cell marker miR-302C and its targets Nanog, c-Myc and Bmi-1 in human chondrosarcoma. To understand better the mechanism of PRP-1 action it was very important to identify the receptor it binds to. Nuclear pathway receptor and GPCR assays indicated that PRP-1 receptors are not G protein coupled, neither do they belong to family of nuclear or orphan receptors. In the present study, we have demonstrated that PRP-1 binding interacting partners belong to innate immunity pattern recognition toll like receptors TLR1/2 and TLR6 and gel forming secreted mucin MUC5B. MUC5B was identified as PRP-1 receptor in human chondrosarcoma JJ012 cell line using Ligand-receptor capture technology. Toll like receptors TLR1/2 and TLR6 were identified as binding interaction partners with PRP-1 by western blot analysis in human chondrosarcoma JJ012 cell line lysates. Immunocytochemistry experiments confirmed the finding and indicated the localization of PRP-1 receptors in the tumor nucleus predominantly. TLR1/2, TLR6 and MUC5B were downregulated in human chondrosarcoma and upregulated in dose-response manner upon PRP-1 treatment. Experimental data indicated that in this cellular context the mentioned receptors had tumor suppressive function.

  13. Pyrrhocoricin, a proline-rich antimicrobial peptide derived from insect, inhibits the translation process in the cell-free Escherichia coli protein synthesis system.

    Science.gov (United States)

    Taniguchi, Masayuki; Ochiai, Akihito; Kondo, Hiroshi; Fukuda, Shun; Ishiyama, Yohei; Saitoh, Eiichi; Kato, Tetsuo; Tanaka, Takaaki

    2016-05-01

    Previous studies have shown that pyrrhocoricin, a proline-rich antimicrobial peptide (PrAMP), killed sensitive species in a dose-dependent manner by specifically binding to DnaK. Here, on the basis of the finding that DnaK-deficient Escherichia coli strains are susceptible to PrAMPs, we used pyrrhocoricin to investigate internal targets other than DnaK. Using conventional antibiotics (bleomycin, streptomycin, and fosfomycin) that have known modes of action, first, we validated the availability of an assay using a cell-free rapid translation system (RTS), which is an in vitro protein synthesis system based on E. coli lysate, for evaluating inhibition of protein synthesis. We found that, similarly to bleomycin and streptomycin, pyrrhocoricin inhibited GFP synthesis in RTS in a concentration-dependent manner. In addition, blockage of transcription and translation steps in RTS was individually estimated using RT-PCR after gene expression to determine mRNA products and using sodium dodecyl sulfate-polyacrylamide gel electrophoresis to determine the amounts of GFP expressed from purified mRNA, respectively. The results demonstrated that this inhibition of GFP synthesis by pyrrhocoricin did not occur at the transcription step but rather at the translation step, in a manner similar to that of GFP synthesis by streptomycin, an inhibitor of the translation step by causing misreading of tRNA. These results suggest that RTS is a powerful assay system for determining if antimicrobial peptides inhibit protein synthesis and its transcription and/or translation steps. This is the first study to have shown that pyrrhocoricin inhibited protein synthesis by specifically repressing the translation step. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Proline-rich tyrosine kinase 2 (Pyk2 regulates IGF-I-induced cell motility and invasion of urothelial carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Marco Genua

    Full Text Available The insulin-like growth factor receptor I (IGF-IR plays an essential role in transformation by promoting cell growth and protecting cancer cells from apoptosis. We have recently demonstrated that the IGF-IR is overexpressed in invasive bladder cancer tissues and promotes motility and invasion of urothelial carcinoma cells. These effects require IGF-I-induced Akt- and MAPK-dependent activation of paxillin. The latter co-localizes with focal adhesion kinases (FAK at dynamic focal adhesions and is critical for promoting motility of urothelial cancer cells. FAK and its homolog Proline-rich tyrosine kinase 2 (Pyk2 modulate paxillin activation; however, their role in regulating IGF-IR-dependent signaling and motility in bladder cancer has not been established. In this study we demonstrate that FAK was not required for IGF-IR-dependent signaling and motility of invasive urothelial carcinoma cells. On the contrary, Pyk2, which was strongly activated by IGF-I, was critical for IGF-IR-dependent motility and invasion and regulated IGF-I-dependent activation of the Akt and MAPK pathways. Using immunofluorescence and AQUA analysis we further discovered that Pyk2 was overexpressed in bladder cancer tissues as compared to normal tissue controls. Significantly, in urothelial carcinoma tissues there was increased Pyk2 localization in the nuclei as compared to normal tissue controls. These results provide the first evidence of a specific Pyk2 activity in regulating IGF-IR-dependent motility and invasion of bladder cancer cells suggesting that Pyk2 and the IGF-IR may play a critical role in the invasive phenotype in urothelial neoplasia. In addition, Pyk2 and the IGF-IR may serve as novel biomarkers with diagnostic and prognostic significance in bladder cancer.

  15. Responsiveness to 6-n-propylthiouracil (PROP is associated with salivary levels of two specific basic proline-rich proteins in humans.

    Directory of Open Access Journals (Sweden)

    Tiziana Cabras

    Full Text Available Thiourea tasting can be predictive of individual differences in bitter taste responses, general food preferences and eating behavior, and could be correlated with saliva chemical composition. We investigated the possible relationship between PROP bitter taste responsiveness and the salivary proteome in subjects genotyped for TAS2R38 and gustin gene polymorphisms. Taste perception intensity evoked by PROP and NaCl solutions was measured in sixty-three volunteers (21 males, 42 females, age 25±3 y to establish their PROP taster status, and 24 PROP super-tasters and 21 nontasters were selected to participate in the study. TAS2R38 and gustin gene molecular analysis were performed using PCR techniques. Qualitative and quantitative determination of salivary proteins was performed by HPLC-ESI-MS before and after PROP taste stimulation. PROP super-tastings was strongly associated with the 'taster' variant (PAV haplotype of TAS2R38 and the A allele of rs2274333 polymorphism in the gustin gene and nontasting was associated with the minor alleles at both loci. ANOVA revealed that basal levels of II-2 and Ps-1 proteins, belonging to the basic proline-rich protein (bPRPs family, were significantly higher in PROP super-taster than in nontaster un-stimulated saliva, and that PROP stimulation elicited a rapid increase in the levels of these same proteins only in PROP super-taster saliva. These data show for the first time that responsiveness to PROP is associated with salivary levels of II-2 peptide and Ps-1 protein, which are products of the PRB1 gene. These findings suggest that PRB1, in addition to TAS2R38 and gustin, could contribute to individual differences in thiourea sensitivity, and the expression of the PROP phenotype as a complex genetic trait.

  16. Responsiveness to 6-n-propylthiouracil (PROP) is associated with salivary levels of two specific basic proline-rich proteins in humans.

    Science.gov (United States)

    Cabras, Tiziana; Melis, Melania; Castagnola, Massimo; Padiglia, Alessandra; Tepper, Beverly J; Messana, Irene; Tomassini Barbarossa, Iole

    2012-01-01

    Thiourea tasting can be predictive of individual differences in bitter taste responses, general food preferences and eating behavior, and could be correlated with saliva chemical composition. We investigated the possible relationship between PROP bitter taste responsiveness and the salivary proteome in subjects genotyped for TAS2R38 and gustin gene polymorphisms. Taste perception intensity evoked by PROP and NaCl solutions was measured in sixty-three volunteers (21 males, 42 females, age 25±3 y) to establish their PROP taster status, and 24 PROP super-tasters and 21 nontasters were selected to participate in the study. TAS2R38 and gustin gene molecular analysis were performed using PCR techniques. Qualitative and quantitative determination of salivary proteins was performed by HPLC-ESI-MS before and after PROP taste stimulation. PROP super-tastings was strongly associated with the 'taster' variant (PAV haplotype) of TAS2R38 and the A allele of rs2274333 polymorphism in the gustin gene and nontasting was associated with the minor alleles at both loci. ANOVA revealed that basal levels of II-2 and Ps-1 proteins, belonging to the basic proline-rich protein (bPRPs) family, were significantly higher in PROP super-taster than in nontaster un-stimulated saliva, and that PROP stimulation elicited a rapid increase in the levels of these same proteins only in PROP super-taster saliva. These data show for the first time that responsiveness to PROP is associated with salivary levels of II-2 peptide and Ps-1 protein, which are products of the PRB1 gene. These findings suggest that PRB1, in addition to TAS2R38 and gustin, could contribute to individual differences in thiourea sensitivity, and the expression of the PROP phenotype as a complex genetic trait.

  17. Design, Synthesis, Molecular Docking, and Antibacterial Evaluation of Some Novel Flouroquinolone Derivatives as Potent Antibacterial Agent

    Directory of Open Access Journals (Sweden)

    Mehul M. Patel

    2014-01-01

    Full Text Available Objective. Quinolone moiety is an important class of nitrogen containing heterocycles widely used as key building blocks for medicinal agents. It exhibits a wide spectrum of pharmacophores and has bactericidal, antiviral, antimalarial, and anticancer activities. In view of the reported antimicrobial activity of various fluoroquinolones, the importance of the C-7 substituents is that they exhibit potent antimicrobial activities. Our objective was to synthesize newer quinolone analogues with increasing bulk at C-7 position of the main 6-fluoroquinolone scaffold to produce the target compounds which have potent antimicrobial activity. Methods. A novel series of 1-ethyl-6-fluoro-4-oxo-7-{4-[2-(4-substituted phenyl-2-(substituted-ethyl]-1-piperazinyl}-1,4-dihydroquinoline-3-carboxylic acid derivatives were synthesized. To understand the interaction of binding sites with bacterial protein receptor, the docking study was performed using topoisomerase II DNA gyrase enzymes (PDB ID: 2XCT by Schrodinger’s Maestro program. In vitro antibacterial activity of the synthesized compounds was studied and the MIC value was calculated by the broth dilution method. Results. Among all the synthesized compounds, some compounds showed potent antimicrobial activity. The compound 8g exhibited good antibacterial activity. Conclusion. This investigation identified the potent antibacterial agents against certain infections.

  18. Study of the interactions between a proline-rich protein and a flavan-3-ol by NMR: residual structures in the natively unfolded protein provides anchorage points for the ligands.

    Science.gov (United States)

    Pascal, Christine; Paté, Franck; Cheynier, Véronique; Delsuc, Marc-André

    2009-09-01

    Astringency is one of the major organoleptic properties of food and beverages that are made from plants, such as tea, chocolate, beer, or red wine. This sensation is thought to be due to interactions between tannins and salivary proline-rich proteins, which are natively unfolded proteins. A human salivary proline-rich protein, namely IB-5, was produced by the recombinant method. Its interactions with a model tannin, epigallocatechin gallate (EGCG), the major flavan-3-ol in green tea, were studied here. Circular dichroism experiments showed that IB-5 presents residual structures (PPII helices) when the ionic strength is close to that in saliva. In the presence of these residual structures, IB-5 undergoes an increase in structural content upon binding to EGCG. NMR data corroborated the presence of preformed structural elements within the protein prior to binding and a partial assignment was proposed, showing partial structuration. TOCSY experiments showed that amino acids that are involved in PPII helices are more likely to interact with EGCG than those in random coil regions, as if they were anchorage points for the ligand. The signal from IB-5 in the DOSY NMR spectrum revealed an increase in polydispersity upon addition of EGCG while the mean hydrodynamic radius remained unchanged. This strongly suggests the formation of IB-5/EGCG aggregates.

  19. Design and Fabrication of Smart Diapers with Antibacterial Yarn

    Directory of Open Access Journals (Sweden)

    Jia-Horng Lin

    2017-01-01

    Full Text Available In this study, intelligent eco-diapers are made by combining antibacterial yarns coated with quaternary ammonium salts with conductive yarns to improve caretaking for urinary incontinence. The combination of conductive yarns and sensors can detect the moisture content in eco-diapers, and an alarm is sent when moisture is significant. A wireless module is used to send detected signals to a smartphone or tablet PC via the Internet. This concept is used for a scenario in which nurses do not randomly check on patients in a long-term care institution. When used offline, eco-diapers can send caregivers an alarm for the need to change diapers via cell phones. The diameters of the copper and silver-plated copper fibers are 0.08 and 0.10 mm, respectively. Cotton yarns are twisted with copper and silver-plated copper fibers to form the conductive yarns, which are 0.12 mm in diameter. Moreover, 30-count cotton and 150 D nylon yarns are coated with quaternary ammonium salt via dyeing and finishing processes to form antibacterial yarns. In the current study, intelligent eco-diapers are tested for their electrical and antibacterial properties as specified by AATC and JISL test standards.

  20. 76 FR 39883 - Design of Clinical Trials for Systemic Antibacterial Drugs for the Treatment of Acute Otitis...

    Science.gov (United States)

    2011-07-07

    ...] Design of Clinical Trials for Systemic Antibacterial Drugs for the Treatment of Acute Otitis Media... Clinical Trials for Systemic Antibacterial Agents for the Treatment of Acute Otitis Media. This public... the treatment of acute otitis media (middle ear infection). Discussions will focus on [[Page 39884...

  1. Synthetic bovine proline-rich-polypeptides generate hydroxyl radicals and fail to protect dopaminergic neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopaminergic neurotoxicity in mice.

    Science.gov (United States)

    Knaryan, Varduhi H; Samantaray, Supriti; Varghese, Merina; Srinivasan, Ambika; Galoyan, Armen A; Mohanakumar, Kochupurackal P

    2006-08-01

    Proline-rich-polypeptides (PRPs) isolated from bovine hypothalamus have been shown to render protection against neuronal injury of the brain and spinal cord. We examined two PRPs containing 15 and 10 amino acid residues (PRP-1 and PRP-4 synthetic polypeptide) for their effect, if any, on dopaminergic neuronal damage caused by the parkinsonian neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Effects of these PRPs on hydroxyl radical ((*)OH) generation in a Fenton-like reaction as well as from isolated mitochondria were monitored, employing a sensitive salicylate hydroxylation procedure. Balb/c mice treated (i.p., twice, 16 h apart) with MPTP (30 mg/kg) or PRP-1 (1.6 mg/kg), but not PRP-4 (1.6 mg/kg) showed significant loss of striatal dopamine and norepinephrine as assayed by an HPLC-electrochemical procedure. Pretreatment with the PRPs, 30 min prior to the neurotoxin administration failed to attenuate MPTP-induced striatal dopamine or norepinephrine depletion, but significantly attenuated the MPTP-induced decrease in dopamine turnover. A significant increase in the generation of (*)OH by the PRPs in a Fenton-like reaction or from isolated mitochondria suggests their pro-oxidant action, and explains their failure to protect against MPTP-induced parkinsonism in mice.

  2. Novel double-stranded RNA viruses of plant-feeding insects encode a serine-alanine-proline rich protein and a polymerase distantly related to fungal viruses

    Science.gov (United States)

    Novel double stranded RNAs (~8 kbp) were isolated from the three cornered alfalfa hopper (Spissistilus festinus) and beet leafhopper (Circulifer tenellus), two plant-feeding hemipteran insect pests. Genome organization of the two new viruses, designated as Spissistilus festinus virus 1 (SpFV1) and ...

  3. Designing N-halamine based antibacterial surface on polymers: Fabrication, characterization, and biocidal functions

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yong, E-mail: ychen168@126.com [Department of Applied Chemistry, College of Chemical and Environmental Engineering, Shandong University of Science and Technology, 579 Qianwangang Rd., Huangdao Zone, Qingdao 266510 (China); Han Qiuxia [Department of Biological Engineering, College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266510 (China)

    2011-05-01

    We demonstrate a valuable method to generate reactive groups on inert polymer surfaces and bond antibacterial agents for biocidal ability. Polystyrene (PS) surfaces were functionalized by spin coating of sub-monolayer and monolayer films of poly(styrene-b-tert-butyl acrylate) (PS-PtBA) block copolymer from solutions in toluene. PS-PtBA self-assembled to a bilayer structure on PS that contains a surface layer of the PtBA blocks ordering at the air-polymer interface and a bottom layer of the PS blocks entangling with the PS substrate. The thickness of PtBA layer could be linearly controlled by the concentration of the spin coating solution and a 2.5 nm saturated monolayer coverage of PtBA was achieved at 0.35% (w/w). Carboxyl groups were generated by exposing the tert-butyl ester groups of PtBA on saturated surface to trifluoroacetic acid (TFA) to bond tert-butylamine via amide bonds that were further chlorinated to N-halamine with NaOCl solution. The density of N-halamine on the chlorinated surface was calculated to be 1.05 x 10{sup -5} mol/m{sup 2} by iodimetric/thiosulfate titration. Presented data showed the N-halamine surface provided powerful antibacterial activities against Staphylococcus aureus and Escherichia coli. Over 50% of the chlorine lost after UVA irradiation could be regained upon rechlorination. This design concept can be virtually applied to any inert polymer by choosing appropriate block copolymers and antibacterial agents to attain desirable biocidal activity.

  4. Direct selection of expressed sequences on a YAC clone revealed proline-rich-like genes and BARE-1 sequences physically linked to the complex ¤Mla¤ powdery mildew resistance locus of barley (¤Hordeum vulgare¤ L.)

    DEFF Research Database (Denmark)

    Schwarz, G.; Michalek, W.; Jahoor, A.

    2002-01-01

    homology to the copia-like retroelement BA REI of barley, putatively involved in evolution of disease resistance loci. The high degree of clones representing barley rRNA sequences or false positives is a major disadvantage of direct selection of cDNAs in barley. (C) 2002 Elsevier Science Ireland Ltd. All...... gene. Of 22 selected cDNA clones, six were re-located on the YAC by southern analysis. Two of these clones are predicted to encode members of the hydroxyproline-rich glycoprotein and proline-rich protein gene families which have been implicated in plant defense response. Four sequences showed high...

  5. Characterization of a human peptide deformylase: implications for antibacterial drug design.

    Science.gov (United States)

    Nguyen, Kiet T; Hu, Xubo; Colton, Craig; Chakrabarti, Ratna; Zhu, Michael X; Pei, Dehua

    2003-08-26

    Ribosomal protein synthesis in eubacteria and eukaryotic organelles initiates with an N-formylmethionyl-tRNA(i), resulting in N-terminal formylation of all nascent polypeptides. Peptide deformylase (PDF) catalyzes the subsequent removal of the N-terminal formyl group from the majority of bacterial proteins. Deformylation was for a long time thought to be a feature unique to the prokaryotes, making PDF an attractive target for designing novel antibiotics. However, recent genomic sequencing has revealed PDF-like sequences in many eukaryotes, including man. In this work, the cDNA encoding Homo sapiens PDF (HsPDF) has been cloned and a truncated form that lacks the N-terminal 58-amino-acid targeting sequence was overexpressed in Escherichia coli. The recombinant, Co(2+)-substituted protein is catalytically active in deformylating N-formylated peptides, shares many of the properties of bacterial PDF, and is strongly inhibited by specific PDF inhibitors. Expression of HsPDF fused to the enhanced green fluorescence protein in human embryonic kidney cells revealed its location in the mitochondrion. However, HsPDF is much less active than its bacterial counterpart, providing a possible explanation for the apparent lack of deformylation in the mammalian mitochondria. The lower catalytic activity is at least partially due to mutation of a highly conserved residue (Leu-91 in E. coli PDF) in mammalian PDF. PDF inhibitors had no detectable effect on two different human cell lines. These results suggest that HsPDF is likely an evolutional remnant without any functional role in protein formylation/deformylation and validates PDF as an excellent target for antibacterial drug design.

  6. Antibacterial Activity of Copper Oxide (CuO Nanoparticles Biosynthesized by Bacillus sp. FU4: Optimization of Experiment Design

    Directory of Open Access Journals (Sweden)

    Mojtaba Taran, Maryam Rad, Mehran Alavi

    2017-09-01

    Full Text Available Background: There are several methods for synthesis of metallic nanoparticles (NPs including chemical, physical and biological process. In this study, Bacillus sp. FU4 was used as biological source for biosynthesis of CuO NPs. Methods: CuO NPs have been prepared by copper sulfate (CuSO4. CuO NPs were formed after oxidation of Cu NPs. Design and analysis of Taguchi experiments (an orthogonal assay and analysis of variance (ANOVA carried out by the Qualitek-4 software. Average effect of CuSO4 concentration (0.1, 0.01 and 0.001 M, incubation and culturing time (48, 72, 96 hours as three controllable factors with three levels were evaluated in CuO NPs biosynthesis. Characterization of CuO NPs was determined by UV-Vis spectroscopy, X-ray diffraction (XRD, Fourier transform infra-red (FT-IR spectroscopy and scanning electron microscopy (SEM. Also, the antimicrobial properties of CuO NPs were investigated using Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 43300 as multidrug resistant (MDR bacteria. Results: Results: It was evaluated that, NPs size distributions were in the range of 2-41 nm with spherical shapes. The anti-bacterial activities of CuO NPs were measured based on diameter of inhibition zone in disk diffusion tests of NPs dispersed in batch cultures. Two levels of CuSO4 concentrations (0.1 and 0.01M had antibacterial effect on E.coli (33±0.57 and 6 ±2mm. In the case of S. aureus, there was surprisingly no sign of growth. Conclusion: CuO NPs have antibacterial activity that can be benefit in medicinal aspect for fighting against prominent pathogen bacteria such as E.coli ATCC 25922 and S.aureus ATCC 43300.

  7. Design and synthesis of an indol derivative as antibacterial agent against Staphylococcus aureus.

    Science.gov (United States)

    Lenin, Hau-Heredia; Lauro, Figueroa-Valverde; Marcela, Rosas-Nexticapa; Socorro, Herrera-Meza; Maria, López-Ramos; Francisco, Díaz-Cedillo; Elodia, García-Cervera; Eduardo, Pool-Gómez; Josefa, Paat-Estrella; Regina, Cauich-Carrillo; Saidy, Euan-Hau

    2017-10-01

    Several indole derivatives with antibacterial activity have been prepared using different protocols; however, some require special reagents and conditions. The aim of this study involved the synthesis of some indole derivatives using estrone and OTBS-estrone as chemical tools. The synthesis of the indole derivatives involves reactions such as follows: (1) synthesis of two indol derivatives ( 4 or 5 ) by reaction of estrone or OTBS-estrone with phenylhydrazine in medium acid; (2) reaction of 4 or 5 with 6-cloro-1-hexyne in medium basic to form two hexynyl-indol ( 7 or 8 ); (3) preparation of indol-propargylic alcohol derivatives ( 10 or 11 ) by reaction of benzaldehyde with 7 or 8 in medium basic; (4) synthesis of indol-aldehydes ( 12 or 13 ) via oxidation of 10 or 11 with DMSO; (5) synthesis of indeno-indol-carbaldehyde ( 15 or 16 ) via alkynylation/cyclization of 12 or 13 with hexyne in presence of copper(II); (6) preparation indeno-indol-carbaldehyde complex ( 19 or 20 ) via alkynylation/cyclization of 12 or 13 with 1-(hex-5-yn-1-yl)-2-phenyl-1 H -imidazole. The antibacterial effect exerted by the indol-steroid derivatives against Streptococcus pneumoniae and Staphylococcus aureus bacteria was evaluated using dilution method and the minimum inhibitory concentration (MIC). The results showed that only the compound 19 inhibit the growth bacterial of S. aureus . In conclusion, these data indicate that antibacterial activity of 19 can be due mainly to functional groups involved in the chemical structure in comparison with the compounds studied.

  8. Design, Synthesis and DFT/DNP Modeling Study of New 2-Amino-5-arylazothiazole Derivatives as Potential Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Sraa Abu-Melha

    2018-02-01

    Full Text Available A new series of 2-amino-5-arylazothiazole derivatives has been designed and synthesized in 61–78% yields and screened as potential antibacterial drug candidates against the Gram negative bacterium Escherichia coli. The geometry of the title compounds were being studied using the Material Studio package and semi-core pseudopods calculations (dspp were performed with the double numerica basis sets plus polarization functional (DNP to predict the properties of materials using the hybrid FT/B3LYP method. Modeling calculations, especially the (EH-EL difference and the energetic parameters revealed that some of the title compounds may be promising tools for further research work and the activity is structure dependent.

  9. Antibacterial textiles

    NARCIS (Netherlands)

    Amrit, Usha

    2015-01-01

    The aim of this thesis was the antibacterial functionalization of textiles and its application in professional laundries. The antibacterial functionalization was meant for the various textile packages lent out by the laundry companies to their customers from hotels, hospital or food industries. The

  10. Antibacterial Resistance Leadership Group: Open for Business

    OpenAIRE

    Chambers, Henry F.; Bartlett, John G.; Bonomo, Robert A.; Chiou, Christine; Cosgrove, Sara E.; Cross, Heather R.; Daum, Robert S.; Downing, Michele; Evans, Scott R.; Knisely, Jane; Kreiswirth, Barry N.; Lautenbach, Ebbing; Mickley, Brenda S.; Patel, Robin; Pettigrew, Melinda M.

    2014-01-01

    The Antibacterial Resistance Leadership Group (ARLG) is tasked with prioritizing, designing, implementing, and conducting clinical studies to address antibacterial resistance. This article outlines clinical research resources and opportunities made available by ARLG and encourages submission of proposals that address antibacterial resistance.

  11. Combined treatment of Thymus vulgaris L., Rosmarinus officinalis L. and Myrtus communis L. essential oils against Salmonella typhimurium: Optimization of antibacterial activity by mixture design methodology.

    Science.gov (United States)

    Fadil, Mouhcine; Fikri-Benbrahim, Kawtar; Rachiq, Saad; Ihssane, Bouchaib; Lebrazi, Sara; Chraibi, Marwa; Haloui, Taoufik; Farah, Abdellah

    2018-05-01

    To increase the sensibility of Salmonella typhimurium strain, a mixture of Thymus vulgaris L. (T. vulgaris L.), Rosmarinus officinalis L. (R. officinalis L.) and Myrtus communis L. (M. communis L.) essential oils (EOs) was used in combined treatment by experimental design methodology (mixture design). The chemical composition of EOs was firstly identified by GC and GC/MS and their antibacterial activity was evaluated. The results of this first step have shown that thymol and borneol were the major compounds in T. vulgaris and M. communis L. EOs, respectively, while 1,8-cineole and α-pinene were found as major compounds in R. officinalis L. The same results have shown a strong antibacterial activity of T. vulgaris L. EO followed by an important power of M. communis L. EO against a moderate activity of R. officinalis L. EO. Besides, 1/20 (v/v) was the concentration giving a strain response classified as sensitive. From this concentration, the mixture design was performed and analyzed. The optimization of mixtures antibacterial activities has highlighted the synergistic effect between T. vulgaris L. and M. communis L. essential oils. A formulation comprising 55% of T. vulgaris L. and 45% of M. communis L. essential oils, respectively, can be considered for the increase of Salmonella typhimurium sensibility. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Evaluation of the Antibacterial Effects of Flavonoid Combination from the Leaves of Dracontomelon dao by Microcalorimetry and the Quadratic Rotary Combination Design

    Science.gov (United States)

    Li, Yang; Xia, Houlin; Wu, Mingquan; Wang, Jiabo; Lu, Xiaohua; Wei, Shizhang; Li, Kun; Wang, Lifu; Wang, Ruilin; Zhao, Pan; Zhao, Yanling; Xiao, Xiaohe

    2017-01-01

    Skin infectious disease is a common public health problem due to the emergence of drug-resistant bacteria caused by the antibiotic misuse. Dracontomelon dao (Blanco) Merr. et Rolfe, a traditional Chinese medicine, has been used for the treatment of various skin infectious diseases over 1000 of years. Previous reports have demonstrated that the leaves of D. dao present favorable antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtitles. The flavonoids are the main components of the ethyl acetate extract of D. dao leaf. However, the correlation between flavonoids and antibacterial activities is yet to be determined. In this study, the combined antibacterial activities of these flavonoids were investigated. Three samples with the different concentrations of flavonoids (S1–S3) were obtained. By microcalorimetric measurements, the results showed that the IC50 value of S2 was lower than those of S1 and S3. The contents of main flavonoids (including Luteolin, L-Epicatechin, Cianidanol, and Quercetin) in S1–S3 were various, confirmed by the method of the Ultra High Performance Liquid Chromatography (UPLC). Based on the method of quadratic general rotary unitized design, the antibacterial effect of single flavonoid, and the potential synergistic effects between Luteolin and Quercetin, Luteolin and Cianidanol were calculated, which were also proved by microcalorimetric analysis. The antibacterial activities of main flavonoids were Luteolin > Cianidanol > Quercetin > L-Epicatechin. Meanwhile, the synergistic effects of Luteolin and Cianidanol (PL+C = 1.425), Quercetin and Luteolin (PL+Q = 1.129) on anti-microbial activity were validated. Finally, we found that the contents of Luteolin, L-Epicatechin, Cianidanol, Quercetin were 1061.00–1061.00, 189.14–262.86, 15,990.33–16,973.62, 6799.67–7662.64 ng·ml−1 respectively, with the antibacterial rate over 60.00%. In conclusion, this study could provide

  13. Rational Design of Novel Allosteric Dihydrofolate Reductase Inhibitors Showing Antibacterial Effects on Drug-Resistant Escherichia coli Escape Variants.

    Science.gov (United States)

    Srinivasan, Bharath; Rodrigues, João V; Tonddast-Navaei, Sam; Shakhnovich, Eugene; Skolnick, Jeffrey

    2017-07-21

    In drug discovery, systematic variations of substituents on a common scaffold and bioisosteric replacements are often used to generate diversity and obtain molecules with better biological effects. However, this could saturate the small-molecule diversity pool resulting in drug resistance. On the other hand, conventional drug discovery relies on targeting known pockets on protein surfaces leading to drug resistance by mutations of critical pocket residues. Here, we present a two-pronged strategy of designing novel drugs that target unique pockets on a protein's surface to overcome the above problems. Dihydrofolate reductase, DHFR, is a critical enzyme involved in thymidine and purine nucleotide biosynthesis. Several classes of compounds that are structural analogues of the substrate dihydrofolate have been explored for their antifolate activity. Here, we describe 10 novel small-molecule inhibitors of Escherichia coli DHFR, EcDHFR, belonging to the stilbenoid, deoxybenzoin, and chalcone family of compounds discovered by a combination of pocket-based virtual ligand screening and systematic scaffold hopping. These inhibitors show a unique uncompetitive or noncompetitive inhibition mechanism, distinct from those reported for all known inhibitors of DHFR, indicative of binding to a unique pocket distinct from either substrate or cofactor-binding pockets. Furthermore, we demonstrate that rescue mutants of EcDHFR, with reduced affinity to all known classes of DHFR inhibitors, are inhibited at the same concentration as the wild-type. These compounds also exhibit antibacterial activity against E. coli harboring the drug-resistant variant of DHFR. This discovery is the first report on a novel class of inhibitors targeting a unique pocket on EcDHFR.

  14. Peptidoglycan glycosyltransferase substrate mimics as templates for the design of new antibacterial drugs

    Directory of Open Access Journals (Sweden)

    Adeline eDerouaux

    2013-03-01

    Full Text Available Peptidoglycan (PG is an essential net-like macromolecule that surrounds bacteria, gives them their shape, and protects them against their own high osmotic pressure. PG synthesis inhibition leads to bacterial cell lysis, making it an important target for many antibiotics. The final two reactions in PG synthesis are performed by penicillin-binding proteins (PBPs. Their glycosyltransferase (GT activity uses the lipid II precursor to synthesize glycan chains and their transpeptidase (TP activity catalyzes the cross-linking of two glycan chains via the peptide side chains. Inhibition of either of these two reactions leads to bacterial cell death. β-Lactam antibiotics target the transpeptidation reaction while antibiotic therapy based on inhibition of the GTs remains to be developed. Ongoing research is trying to fill this gap by studying the interactions of GTs with inhibitors and substrate mimics and utilizing the latter as templates for the design of new antibiotics. In this mini review we present an updated overview on the GTs and describe the structure-activity relationship of recently developed synthetic ligands.

  15. Enantioselective Total Synthesis of Antibiotic CJ-16,264, Synthesis and Biological Evaluation of Designed Analogues, and Discovery of Highly Potent and Simpler Antibacterial Agents.

    Science.gov (United States)

    Nicolaou, K C; Pulukuri, Kiran Kumar; Rigol, Stephan; Buchman, Marek; Shah, Akshay A; Cen, Nicholas; McCurry, Megan D; Beabout, Kathryn; Shamoo, Yousif

    2017-11-08

    An improved and enantioselective total synthesis of antibiotic CJ-16,264 through a practical kinetic resolution and an iodolactonization reaction to form the iodo pyrrolizidinone fragment of the molecule is described. A series of racemic and enantiopure analogues of CJ-16,264 was designed and synthesized through the developed synthetic technologies and tested against drug-resistant bacterial strains. These studies led to interesting structure-activity relationships and the identification of a number of simpler, and yet equipotent, or even more potent, antibacterial agents than the natural product, thereby setting the foundation for further investigations in the quest for new anti-infective drugs.

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

    Science.gov (United States)

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

    2012-10-01

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

  17. Design, Synthesis and Evaluation of Branched RRWQWR-Based Peptides as Antibacterial Agents Against Clinically Relevant Gram-Positive and Gram-Negative Pathogens

    Directory of Open Access Journals (Sweden)

    Sandra C. Vega

    2018-03-01

    Full Text Available Multidrug resistance of pathogenic bacteria has become a public health crisis that requires the urgent design of new antibacterial drugs such as antimicrobial peptides (AMPs. Seeking to obtain new, lactoferricin B (LfcinB-based synthetic peptides as viable early-stage candidates for future development as AMPs against clinically relevant bacteria, we designed, synthesized and screened three new cationic peptides derived from bovine LfcinB. These peptides contain at least one RRWQWR motif and differ by the copy number (monomeric, dimeric or tetrameric and structure (linear or branched of this motif. They comprise a linear palindromic peptide (RWQWRWQWR, a dimeric peptide (RRWQWR2KAhx and a tetrameric peptide (RRWQWR4K2Ahx2C2. They were screened for antibacterial activity against Enterococcus faecalis (ATCC 29212 and ATCC 51575 strains, Pseudomonas aeruginosa (ATCC 10145 and ATCC 27853 strains and clinical isolates of two Gram-positive bacteria (Enterococcus faecium and Staphylococcus aureus and two Gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa. All three peptides exhibited greater activity than did the reference peptide, LfcinB (17–31, which contains a single linear RRWQWR motif. Against the ATCC reference strains, the three new peptides exhibited minimum inhibitory concentration (MIC50 values of 3.1–198.0 μM and minimum bactericidal concentration (MBC values of 25–200 μM, and against the clinical isolates, MIC50 values of 1.6–75.0 μM and MBC values of 12.5–100 μM. However, the tetrameric peptide was also found to be strongly hemolytic (49.1% at 100 μM. Scanning Electron Microscopy (SEM demonstrated that in the dimeric and tetrameric peptides, the RRWQWR motif is exposed to the pathogen surface. Our results may inform the design of new, RRWQWR-based AMPs.

  18. Antibacterial components of honey

    NARCIS (Netherlands)

    Kwakman, Paulus H. S.; Zaat, Sebastian A. J.

    2012-01-01

    The antibacterial activity of honey has been known since the 19th century. Recently, the potent activity of honey against antibiotic-resistant bacteria has further increased the interest for application of honey, but incomplete knowledge of the antibacterial activity is a major obstacle for clinical

  19. Antibacterial Resistance in African Catfish Aquaculture: a Review

    Directory of Open Access Journals (Sweden)

    Madubuike U. ANYANWU

    2016-03-01

    Full Text Available Antibacterial resistance (AR is currently one of the greatest threats to mankind as it constitutes health crisis. Extensive use of antibacterial agents in human and veterinary medicine, and farm crops have resulted in emergence of antibacterial-resistant organisms in different environmental settings including aquaculture. Antibacterial resistance in aquaculture is a serious global concern because antibacterial resistance genes (ARGs can be transferred easily from aquaculture setting to other ecosystems and the food chain. African catfish (ACF aquaculture has increased at a phenomenal rate through a continuous process of intensification, expansion and diversification. Risk of bacterial diseases has also increased and consequently there is increased use of antibacterial agents for treatment. Antibacterial resistance in ACF aquaculture has huge impact on the food chain and thus represents risk to public and animal health. In “one health” approach of curbing AR, knowledge of the sources, mechanisms and magnitude of AR in ACF aquaculture and its potential impact on the food chain is important in designing and prioritizing monitoring programs that may generate data that would be relevant for performing quantitative risk assessments, implementation of antibacterial stewardship plans, and developing effective treatment strategies for the control of ACF disease and reducing risk to public health. This review provides insight on the sources, mechanisms, prevalence and impact of antibacterial resistance in ACF aquaculture environment, a setting where the impact of AR is neglected or underestimated.

  20. Design, Synthesis, Fluorescence Properties and Antibacterial Activities of New 8-Chloro-3-Alkyl-3H-Pyrazolo[4,3-a]acridine-11-Carbonitriles

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, Zeynab; Pordel, Mehdi; Davoodnia, Abolghasem [Islamic Azad Univ., Mashhad (Iran, Islamic Republic of)

    2014-02-15

    The treatment of alkylated nitro derivatives of indazole with 2-(4-chlorophenyl)acetonitrile under basic conditions gave the new 8-chloro-3-alkyl-3H-pyrazolo[4,3-a]acridine-11-carbonitriles via the nucleophilic substitution of hydrogen which proceeds at room temperature with concomitant cyclisation in fairly good yields. The structures of all newly synthesized compounds were confirmed by IR, {sup 1}H NMR, {sup 13}C NMR and mass spectral data. Fluorescence experimental results of all newly synthesized compounds revealed remarkable photoluminescence properties and strong green fluorescence properties. Also, the new compounds exhibited potent antibacterial activity and their antibacterial activity (MIC) against Gram positive (Staphylococcuse aureus methicillin resistant S. aureus and Bacillus subtilis) and negative bacterial (Pseudomonas aeruginosa and Escherichia coli) species were determined.

  1. Antibacterial and antifungal properties of guanylhydrazones

    Directory of Open Access Journals (Sweden)

    Ajdačić Vladimir

    2017-01-01

    Full Text Available A series of novel guanylhydrazones were designed, synthesized and characterized. All the compounds were screened for their antibacterial and antifungal activity. Compounds 26 and 27 showed excellent antibacterial activities against Staphylococcus aureus ATCC 25923 and Micrococcus luteus ATCC 379 with minimal inhibitory concentrations of 4 μg mL-1, and good antifungal activity against Candida parapsilosis ATCC 22019. These results suggested that the selected guanylhydrazones could serve as promising leads for improved antimicrobial development. [Project of the Ministry of Education, Science and Technological Development of the Republic of Serbia, Grant No. 172008 and Grant No. 173048

  2. METAL OXIDE DOPED ANTIBACTERIAL POLYMERIC COATED TEXTILE MATERIALS AND ASSESSEMENT OF ANTIBACTERIAL ACTIVITY WITH ELECTRON SPIN RESONANCE

    Directory of Open Access Journals (Sweden)

    GEDIK Gorkem

    2017-05-01

    Full Text Available Antibacterial activity of a food conveyor belt is an essential property in some cases. However, every antibacterial chemical is not suitable to contact with food materials. Many metal oxides are suitable option for this purpose. The aim of this study was to investigate antibacterial properties of zinc oxide doped PVC polymer coated with electron spin resonance technique. Therefore, optimum zinc oxide containing PVC paste was prepared and applied to textile surface. Coating construction was designed as double layered, first layer did not contain antibacterial agent, thin second layer contained zinc oxide at 10-35% concentration. Oxygen radicals released from zinc oxide containing polymeric coated surface were spin trapped with DMPO (dimethylpyrroline-N-oxide spin trap and measured with Electron Spin Resonance (ESR. Besides conveyor belt samples, oxygen radical release from zinc oxide surface was measured with ESR under UV light and dark conditions. Oxygen radical release was determined even at dark conditions. Antibacterial properties were tested with ISO 22196 standard using Listeria innocua species. Measured antibacterial properties were related with ESR results. Higher concentration of zinc oxide resulted in higher antibacterial efficiency. DCFH-DA flourometric assay was carried out to determine oxidative stress insidebacteria. It is tought that, this technique will lead to decrease on the labour and time needed for conventional antibacterial tests.

  3. The oxadiazole antibacterials.

    Science.gov (United States)

    Janardhanan, Jeshina; Chang, Mayland; Mobashery, Shahriar

    2016-10-01

    The oxadiazoles are a class of antibacterials discovered by in silico docking and scoring of compounds against the X-ray structure of a penicillin-binding protein. These antibacterials exhibit activity against Gram-positive bacteria, including against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). They show in vivo efficacy in murine models of peritonitis/sepsis and neutropenic thigh MRSA infection. They are bactericidal and orally bioavailable. The oxadiazoles show promise in treatment of MRSA infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. [Distiller Yeasts Producing Antibacterial Peptides].

    Science.gov (United States)

    Klyachko, E V; Morozkina, E V; Zaitchik, B Ts; Benevolensky, S V

    2015-01-01

    A new method of controlling lactic acid bacteria contamination was developed with the use of recombinant Saccharomyces cerevisiae strains producing antibacterial peptides. Genes encoding the antibacterial peptides pediocin and plantaricin with codons preferable for S. cerevisiae were synthesized, and a system was constructed for their secretory expression. Recombinant S. cerevisiae strains producing antibacterial peptides effectively inhibit the growth of Lactobacillus sakei, Pediacoccus pentasaceus, Pediacoccus acidilactici, etc. The application of distiller yeasts producing antibacterial peptides enhances the ethanol yield in cases of bacterial contamination. Recombinant yeasts producing the antibacterial peptides pediocin and plantaricin can successfully substitute the available industrial yeast strains upon ethanol production.

  5. Application of Box-Behnken design for preparation of levofloxacin-loaded stearic acid solid lipid nanoparticles for ocular delivery: Optimization, in vitro release, ocular tolerance, and antibacterial activity.

    Science.gov (United States)

    Baig, Mirza Salman; Ahad, Abdul; Aslam, Mohammed; Imam, Syed Sarim; Aqil, Mohd; Ali, Asgar

    2016-04-01

    The aim of the present study was to develop and optimize levofloxacin loaded solid lipid nanoparticles for the treatment of conjunctivitis. Box-Behnken experimental design was applied for optimization of solid lipid nanoparticles. The independent variables were stearic acid as lipid (X1), Tween 80 as surfactant (X2) and sodium deoxycholate as co-surfactant (X3) while particle size (Y1) and entrapment efficiency (Y2) were the dependent variables. Further in vitro release and antibacterial activity in vitro were also performed. The optimized formulation of levofloxacin provides particle size of 237.82 nm and showed 78.71% entrapment efficiency and achieved flux 0.2,493 μg/cm(2)/h across excised goat cornea. In vitro release study showed prolonged drug release from the optimized formulation following Korsmeyer-Peppas model. Antimicrobial study revealed that the developed formulation possesses antibacterial activity against Staphylococcus aureus, and Escherichia coli equivalent to marketed eye drops. HET-CAM test demonstrated that optimized formulation was found to be non-irritant and safe for topical ophthalmic use. Our results concluded that solid lipid nanoparticles are an efficient carrier for ocular delivery of levofloxacin and other drugs. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Antibacterial Activity of Oenothera rosea (L 'Her) Leaf Extracts

    OpenAIRE

    Gomez-Flores, Ricardo; Reyna-Martínez, Raúl; Tamez-Guerra, Patricia; Quintanilla-Licea, Ramiro

    2012-01-01

    Aims: To determine the antibacterial effect of Oenothera rosea against Escherichia coli, Salmonella enteritidis and Vibrio cholerae. Study Design: In vitro antibacterial study. Place and Duration of Study: Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Departamento de Microbiología e Inmunología and Departamento de Química, San Nicolás de los Garza, NL. México, from June 2010 to June 2011. Methodology: The antibacterial in vitro effect of methanol and aqueous extracts of...

  7. Antibacterial Surface Design of Titanium-Based Biomaterials for Enhanced Bacteria-Killing and Cell-Assisting Functions Against Periprosthetic Joint Infection.

    Science.gov (United States)

    Wang, Jiaxing; Li, Jinhua; Qian, Shi; Guo, Geyong; Wang, Qiaojie; Tang, Jin; Shen, Hao; Liu, Xuanyong; Zhang, Xianlong; Chu, Paul K

    2016-05-04

    Periprosthetic joint infection (PJI) is one of the formidable and recalcitrant complications after orthopedic surgery, and inhibiting biofilm formation on the implant surface is considered crucial to prophylaxis of PJI. However, it has recently been demonstrated that free-floating biofilm-like aggregates in the local body fluid and bacterial colonization on the implant and peri-implant tissues can coexist and are involved in the pathogenesis of PJI. An effective surface with both contact-killing and release-killing antimicrobial capabilities can potentially abate these concerns and minimize PJI caused by adherent/planktonic bacteria. Herein, Ag nanoparticles (NPs) are embedded in titania (TiO2) nanotubes by anodic oxidation and plasma immersion ion implantation (PIII) to form a contact-killing surface. Vancomycin is then incorporated into the nanotubes by vacuum extraction and lyophilization to produce the release-killing effect. A novel clinical PJI model system involving both in vitro and in vivo use of methicillin-resistant Staphylococcus aureus (MRSA) ST239 is established to systematically evaluate the antibacterial properties of the hybrid surface against planktonic and sessile bacteria. The vancomycin-loaded and Ag-implanted TiO2 nanotubular surface exhibits excellent antimicrobial and antibiofilm effects against planktonic/adherent bacteria without appreciable silver ion release. The fibroblasts/bacteria cocultures reveal that the surface can help fibroblasts to combat bacteria. We first utilize the nanoarchitecture of implant surface as a bridge between the inorganic bactericide (Ag NPs) and organic antibacterial agent (vancomycin) to achieve total victory in the battle of PJI. The combination of contact-killing and release-killing together with cell-assisting function also provides a novel and effective strategy to mitigate bacterial infection and biofilm formation on biomaterials and has large potential in orthopedic applications.

  8. PRODUCTION OF ANTIBACTERIAL FILTER PAPER FROM WOOD CELLULOSE

    OpenAIRE

    Reza Imani; Mohammad Talaiepour; Joydeep Dutta; Mohammad R. Ghobadinezhad; Amir H. Hemmasi; Mousa M. Nazhad

    2011-01-01

    Paper has a visible market-share in hygiene products either in the form of personal hygiene or as food packaging. The designation “hygiene”, though it suggests cleanliness, does not imply antibacterial properties; rather it can be stated that hygiene products do not initiate microorganism growth. Antibacterial products could restrict propagation of pathogenic bacteria either by holding bacteria or by trapping and neutralizing them. Most research in this field has been conducted using textile ...

  9. Antibacterial Applications of Nanodiamonds.

    Science.gov (United States)

    Szunerits, Sabine; Barras, Alexandre; Boukherroub, Rabah

    2016-04-12

    Bacterial infectious diseases, sharing clinical characteristics such as chronic inflammation and tissue damage, pose a major threat to human health. The steady increase of multidrug-resistant bacteria infections adds up to the current problems modern healthcare is facing. The treatment of bacterial infections with multi-resistant germs is very difficult, as the development of new antimicrobial drugs is hardly catching up with the development of antibiotic resistant pathogens. These and other considerations have generated an increased interest in the development of viable alternatives to antibiotics. A promising strategy is the use of nanomaterials with antibacterial character and of nanostructures displaying anti-adhesive activity against biofilms. Glycan-modified nanodiamonds (NDs) revealed themselves to be of great promise as useful nanostructures for combating microbial infections. This review summarizes the current efforts in the synthesis of glycan-modified ND particles and evaluation of their antibacterial and anti-biofilm activities.

  10. Antibacterial Applications of Nanodiamonds

    Directory of Open Access Journals (Sweden)

    Sabine Szunerits

    2016-04-01

    Full Text Available Bacterial infectious diseases, sharing clinical characteristics such as chronic inflammation and tissue damage, pose a major threat to human health. The steady increase of multidrug-resistant bacteria infections adds up to the current problems modern healthcare is facing. The treatment of bacterial infections with multi-resistant germs is very difficult, as the development of new antimicrobial drugs is hardly catching up with the development of antibiotic resistant pathogens. These and other considerations have generated an increased interest in the development of viable alternatives to antibiotics. A promising strategy is the use of nanomaterials with antibacterial character and of nanostructures displaying anti-adhesive activity against biofilms. Glycan-modified nanodiamonds (NDs revealed themselves to be of great promise as useful nanostructures for combating microbial infections. This review summarizes the current efforts in the synthesis of glycan-modified ND particles and evaluation of their antibacterial and anti-biofilm activities.

  11. Proline-rich peptide from the coral pathogen Vibrio shiloi that inhibits photosynthesis of Zooxanthellae.

    Science.gov (United States)

    Banin, E; Khare, S K; Naider, F; Rosenberg, E

    2001-04-01

    The coral-bleaching bacterium Vibrio shiloi biosynthesizes and secretes an extracellular peptide, referred to as toxin P, which inhibits photosynthesis of coral symbiotic algae (zooxanthellae). Toxin P was produced during the stationary phase when the bacterium was grown on peptone or Casamino Acids media at 29 degrees C. Glycerol inhibited the production of toxin P. Toxin P was purified to homogeneity, yielding the following 12-residue peptide: PYPVYAPPPVVP (molecular weight, 1,295.54). The structure of toxin P was confirmed by chemical synthesis. In the presence of 12.5 mM NH(4)Cl, pure natural or synthetic toxin P (10 microM) caused a 64% decrease in the photosynthetic quantum yield of zooxanthellae within 5 min. The inhibition was proportional to the toxin P concentration. Toxin P bound avidly to zooxanthellae, such that subsequent addition of NH(4)Cl resulted in rapid inhibition of photosynthesis. When zooxanthellae were incubated in the presence of NH(4)Cl and toxin P, there was a rapid decrease in the pH (pH 7.8 to 7.2) of the bulk liquid, suggesting that toxin P facilitates transport of NH(3) into the cell. It is known that uptake of NH(3) into cells can destroy the pH gradient and block photosynthesis. This mode of action of toxin P can help explain the mechanism of coral bleaching by V. shiloi.

  12. PPII propensity of multiple-guest amino acids in a proline-rich environment.

    Science.gov (United States)

    Moradi, Mahmoud; Babin, Volodymyr; Sagui, Celeste; Roland, Christopher

    2011-07-07

    There has been considerable debate about the intrinsic PPII propensity of amino acid residues in denatured polypeptides. Experimentally, this scale is based on the behavior of guest amino acid residues placed in the middle of proline-based hosts. We have used classical molecular dynamics simulations combined with replica-exchange methods to carry out a comprehensive analysis of the conformational equilibria of proline-based host oligopeptides with multiple guest amino acids including alanine, glutamine, valine, and asparagine. The tracked structural characteristics include the secondary structural motifs based on the Ramachandran angles and the cis/trans isomerization of the prolyl bonds. In agreement with our recent study of single amino acid guests, we did not observe an intrinsic PPII propensity in any of the guest amino acids in a multiple-guest setting. Instead, the experimental results can be explained in terms of (i) the steric restrictions imposed on the C-terminal guest amino acid that is immediately followed by a proline residue and (ii) an increase in the trans content of the prolyl bonds due to the presence of guest residues. In terms of the latter, we found that the more guests added to the system, the larger the increase in the trans content of the prolyl bonds, which results in an effective increase in the PPII content of the peptide.

  13. Ginkgotides: Proline-Rich Hevein-Like Peptides from Gymnosperm Ginkgo biloba.

    Science.gov (United States)

    Wong, Ka H; Tan, Wei Liang; Serra, Aida; Xiao, Tianshu; Sze, Siu Kwan; Yang, Daiwen; Tam, James P

    2016-01-01

    Hevein and hevein-like peptides belong to the family of chitin-binding cysteine-rich peptides. They are classified into three subfamilies, the prototypic 8C- and the 6C- and 10C-hevein-like peptides. Thus far, only five 8C-hevein-like peptides have been characterized from three angiosperms and none from gymnosperm. To determine their occurrence and distribution in the gymnosperm, Ginkgo biloba leaves were examined. Here, we report the discovery and characterization of 11 novel 8C-hevein-like peptides, namely ginkgotides gB1-gB11. Proteomic analysis showed that the ginkgotides contain 41-44 amino acids (aa), a chitin-binding domain and are Pro-rich, a distinguishing feature that differs from other hevein-like peptides. Solution NMR structure determination revealed that gB5 contains a three β-stranded structure shaped by a cystine knot with an additional disulfide bond at the C-terminus. Transcriptomic analysis showed that the ginkgotide precursors contain a three-domain architecture, comprised of a C-terminal tail (20 aa) that is significantly shorter than those of other 8C- and 10C-hevein-like peptides, which generally contain a protein cargo such as a Barwin-like protein (126 aa) or class I chitinase (254 aa). Transcriptomic data mining found an additional 48 ginkgotide homologs in 39 different gymnosperms. Phylogenetic analysis revealed that ginkgotides and their homologs belong to a new class of 8C-hevein-like peptides. Stability studies showed that ginkgotides are highly resistant to thermal, acidic and endopeptidase degradation. Ginkgotides flanked at both the N- and C-terminal ends by Pro were resistant to exopeptidase degradation by carboxypeptidase A and aminopeptidase. Antifungal assays showed that ginkgotides inhibit the hyphal growth of phyto-pathogenic fungi. Taken together, ginkgotides represent the first suite of hevein-like peptides isolated and characterized from gymnosperms. As a group, they represent a novel class of 8C-hevein-like peptides that are Pro-rich and protein-cargo free. Our findings also suggest that the ginkgotide scaffold could be useful for engineering metabolic-stable peptide therapeutics.

  14. Ginkgotides: Proline-rich Hevein-like Peptides from Gymnosperm Ginkgo biloba

    Directory of Open Access Journals (Sweden)

    Ka Ho Wong

    2016-11-01

    Full Text Available Hevein and hevein-like peptides belong to the family of chitin-binding cysteine-rich peptides. They are classified into three subfamilies, the prototypic 8C- and the 6C- and 10C-hevein-like peptides. Thus far, only five 8C-hevein-like peptides have been characterized from three angiosperms and none from gymnosperm. To determine their occurrence and distribution in the gymnosperm, Ginkgo biloba leaves were examined. Here, we report the discovery and characterization of eleven novel 8C-hevein-like peptides, namely ginkgotides gB1–gB11. Proteomic analysis showed that the ginkgotides contain 41–44 amino acids (aa, a chitin-binding domain and are Pro-rich, a distinguishing feature that differs from other hevein-like peptides. Solution 1H-NMR structure determination revealed that gB5 contains a three β-stranded structure shaped by a cystine knot with an additional disulfide bond at the C-terminus. Transcriptomic analysis showed that the ginkgotide precursors contain a three-domain architecture, comprised of a C-terminal tail (20 aa that is significantly shorter than those of other 8C- and 10C-hevein-like peptides, which generally contain a protein cargo such as a Barwin-like protein (126 aa or class I chitinase (254 aa. Transcriptomic data mining found an additional 48 ginkgotide homologs in 39 different gymnosperms. Phylogenetic analysis revealed that ginkgotides and their homologs belong to a new class of 8C-hevein-like peptides. Stability studies showed that ginkgotides are highly resistant to thermal, acidic and endopeptidase degradation. Ginkgotides flanked at both the N- and C-terminal ends by Pro were resistant to exopeptidase degradation by carboxypeptidase A and aminopeptidase. Antifungal assays showed that ginkgotides inhibit the hyphal growth of phyto-pathogenic fungi. Taken together, ginkgotides represent the first suite of hevein-like peptides isolated and characterized from gymnosperms. As a group, they represent a novel class of 8C-hevein-like peptides that are Pro-rich and protein-cargo free. Our findings also suggest that the ginkgotide scaffold could be useful for engineering metabolic-stable peptide therapeutics.

  15. Normal Development and Function of T Cells in Proline Rich 7 (Prr7) Deficient Mice

    Czech Academy of Sciences Publication Activity Database

    Hrdinka, M.; Sudan, K.; Just, S.; Drobek, Aleš; Štěpánek, Ondřej; Schlueter, D.; Reinhold, D.; Jordan, B.A.; Gintschel, P.; Schraven, B.; Kreutz, M.R.

    2016-01-01

    Roč. 11, č. 9 (2016), č. článku e0162863. E-ISSN 1932-6203 R&D Projects: GA ČR GJ16-09208Y Institutional support: RVO:68378050 Keywords : transmembrane adapter proteins * experimental autoimmune encephalomyelitis * multiple-sclerosis * listeria - monocytogenes * lymphocyte development * negative regulation * activation * receptor * neurodegeneration * apoptosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.806, year: 2016

  16. The biology of Mur ligases as an antibacterial target.

    Science.gov (United States)

    Kouidmi, Imène; Levesque, Roger C; Paradis-Bleau, Catherine

    2014-10-01

    With antibiotic resistance mechanisms increasing in diversity and spreading among bacterial pathogens, the development of new classes of antibacterial agents against judiciously chosen targets is a high-priority task. The biochemical pathway for peptidoglycan biosynthesis is one of the best sources of antibacterial targets. Within this pathway are the Mur ligases, described in this review as highly suitable targets for the development of new classes of antibacterial agents. The amide ligases MurC, MurD, MurE and MurF function with the same catalytic mechanism and share conserved amino acid regions and structural features that can conceivably be exploited for the design of inhibitors that simultaneously target more than one enzyme. This would provide multi-target antibacterial weapons with minimized likelihood of target-mediated resistance development. © 2014 John Wiley & Sons Ltd.

  17. Compound design guidelines for evading the efflux and permeation barriers of Escherichia coli with the oxazolidinone class of antibacterials: Test case for a general approach to improving whole cell Gram-negative activity.

    Science.gov (United States)

    Spaulding, Andrew; Takrouri, Khuloud; Mahalingam, Pornachandran; Cleary, Dillon C; Cooper, Harold D; Zucchi, Paola; Tear, Westley; Koleva, Bilyana; Beuning, Penny J; Hirsch, Elizabeth B; Aggen, James B

    2017-12-01

    Previously we reported the results from an effort to improve Gram-negative antibacterial activity in the oxazolidinone class of antibiotics via a systematic medicinal chemistry campaign focused entirely on C-ring modifications. In that series we set about testing if the efflux and permeation barriers intrinsic to the outer membrane of Escherichia coli could be rationally overcome by designing analogs to reside in specific property limits associated with Gram-negative activity: i) low MW (<400), ii) high polarity (clogD 7.4 <1), and iii) zwitterionic character at pH 7.4. Indeed, we observed that only analogs residing within these limits were able to overcome these barriers. Herein we report the results from a parallel effort where we explored structural changes throughout all three rings in the scaffold for the same purpose. Compounds were tested against a diagnostic MIC panel of Escherichia coli and Staphylococcus aureus strains to determine the impact of combining structural modifications in overcoming the OM barriers and in bridging the potency gap between the species. The results demonstrated that distributing the charge-carrying moieties across two rings was also beneficial for avoidance of the outer membrane barriers. Importantly, analysis of the structure-permeation relationship (SPR) obtained from this and the prior study indicated that in addition to MW, polarity, and zwitterionic character, having ≤4 rotatable bonds is also associated with evasion of the OM barriers. These combined results provide the medicinal chemist with a framework and strategy for overcoming the OM barriers in GNB in antibacterial drug discovery efforts. Copyright © 2017. Published by Elsevier Ltd.

  18. Carbon Nanomaterials as Antibacterial Colloids

    Directory of Open Access Journals (Sweden)

    Michael Maas

    2016-07-01

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

  19. Antibacterial Au nanostructured surfaces

    Science.gov (United States)

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-01-01

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies.We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all

  20. Bioactive and biocompatible copper containing glass-ceramics with remarkable antibacterial properties and high cell viability designed for future in vivo trials.

    Science.gov (United States)

    Popescu, R A; Magyari, K; Vulpoi, A; Trandafir, D L; Licarete, E; Todea, M; Ştefan, R; Voica, C; Vodnar, D C; Simon, S; Papuc, I; Baia, L

    2016-07-19

    In the present study our interest is focused on finding the efficiency of 60SiO2·(32 - x)CaO·8P2O5·xCuO (mol%) glass-ceramics, with 0 ≤ x ≤ 4 mol%, in terms of bioactivity, biocompatibility, antibacterial properties and cell viability in order to determine the most appropriate composition for their further use in in vivo trials. The sol-gel synthesized samples show a preponderantly amorphous structure with a few crystallization centers associated with the formation of an apatite and calcium carbonate crystalline phases. The Fourier Transform Infrared (FT-IR) spectra revealed slightly modified absorption bands due to the addition of copper oxide, while the information derived from the measurements performed by transmission electron microscopy, UV-vis and electron paramagnetic resonance spectroscopy showed the presence of ions and metallic copper species. X-Ray photoelectron spectroscopic analysis indicated the presence of copper metallic species, in a reduced amount, only on the sample surface with the highest Cu content. Regarding in vitro assessment of bioactivity, the results obtained by X-ray diffraction, FT-IR spectroscopy and scanning electron microscopy, demonstrated the formation of a calcium phosphate layer on all investigated sample surfaces. The inhibitory effect of the investigated samples was more significant on the Pseudomonas aeruginosa than the Staphylococcus aureus strain, the sample with the lowest concentration of copper oxide (0.5 mol%) being also the most efficient in both bacterial cultures. This sample also exhibits a very good bactericidal activity, for the other samples it was necessary to use a higher quantity to inhibit and kill the bacterial species. The secondary structure of adsorbed albumin presents few minor changes, indicating the biocompatibility of the glass-ceramics. The cell viability assay shows a good proliferation rate on samples with 0.5 and 1.5 mol% CuO, although all glass-ceramic samples exhibited a good in vivo

  1. Synthesis and in vitro antibacterial activity of oxazolidine LBM-415 analogs as peptide deformylase inhibitors.

    Science.gov (United States)

    Yu, Linliang; Zhou, Weicheng; Wang, Zhenyu

    2011-03-01

    The drug resistant bacteria pose a severe threat to human health. The increasing resistance of those pathogens to traditional antibacterial therapy renders the identification of new antibacterial agents with novel antibacterial mechanisms an urgent need. In this study, a series of (2S)-N-substituted-1-[(formyhydroxyamino)methyl]-1-oxohexyl]-2-oxazolidinecarboxamides were designed, synthesized and evaluated for in vitro antibacterial activity. Most of these compounds displayed good activities against Gram-positive organisms comparable to reference agent LBM-415. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  2. Antibacterial Au nanostructured surfaces.

    Science.gov (United States)

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-02-07

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies.

  3. Antibacterial activity of antileukoprotease.

    Science.gov (United States)

    Hiemstra, P S; Maassen, R J; Stolk, J; Heinzel-Wieland, R; Steffens, G J; Dijkman, J H

    1996-01-01

    Antileukoprotease (ALP), or secretory leukocyte proteinase inhibitor, is an endogenous inhibitor of serine proteinases that is present in various external secretions. ALP, one of the major inhibitors of serine proteinases present in the human lung, is a potent reversible inhibitor of elastase and, to a lesser extent, of cathepsin G. In equine neutrophils, an antimicrobial polypeptide that has some of the characteristics of ALP has been identified (M. A. Couto, S. S. L. Harwig, J. S. Cullor, J. P. Hughes, and R. I. Lehrer, Infect. Immun. 60:5042-5047, 1992). This report, together with the cationic nature of ALP, led us to investigate the antimicrobial activity of ALP. ALP was shown to display marked in vitro antibacterial activity against Escherichia coli and Staphylococcus aureus. On a molar basis, the activity of ALP was lower than that of two other cationic antimicrobial polypeptides, lysozyme and defensin. ALP comprises two homologous domains: its proteinase-inhibitory activities are known to be located in the second COOH-terminal domain, and the function of its first NH2-terminal domain is largely unknown. Incubation of intact ALP or its isolated first domain with E. coli or S. aureus resulted in killing of these bacteria, whereas its second domain displayed very little antibacterial activity. Together these data suggest a putative antimicrobial role for the first domain of ALP and indicate that its antimicrobial activity may equip ALP to contribute to host defense against infection. PMID:8890201

  4. Antibacterial biodegradable Mg-Ag alloys

    Directory of Open Access Journals (Sweden)

    D Tie

    2013-06-01

    Full Text Available The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4 and aging (T6 heat treatment.The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7, revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231 and Staphylococcus epidermidis (DSMZ 3269, and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  5. Antibacterial Metallic Touch Surfaces

    Directory of Open Access Journals (Sweden)

    Victor M. Villapún

    2016-08-01

    Full Text Available Our aim is to present a comprehensive review of the development of modern antibacterial metallic materials as touch surfaces in healthcare settings. Initially we compare Japanese, European and US standards for the assessment of antimicrobial activity. The variations in methodologies defined in these standards are highlighted. Our review will also cover the most relevant factors that define the antimicrobial performance of metals, namely, the effect of humidity, material geometry, chemistry, physical properties and oxidation of the material. The state of the art in contact-killing materials will be described. Finally, the effect of cleaning products, including disinfectants, on the antimicrobial performance, either by direct contact or by altering the touch surface chemistry on which the microbes attach, will be discussed. We offer our outlook, identifying research areas that require further development and an overview of potential future directions of this exciting field.

  6. Antibacterial activity of Ficus capensis

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    Allium sativum) is used to reduce cholesterol levels and to boost immune system; it lowers high blood pressure and its oil has been seen to have antibacterial properties (Juurlink, 2001). Milk thistle. Silybum marianum has also ...

  7. Antibacterial resistance: an emerging 'zoonosis'?

    Science.gov (United States)

    Labro, Marie-Thérèse; Bryskier, Jean-Marie

    2014-12-01

    Antibacterial resistance is a worldwide threat, and concerns have arisen about the involvement of animal commensal and pathogenic bacteria in the maintenance and spread of resistance genes. However, beyond the facts related to the occurrence of resistant microorganisms in food, food-producing animals and companion animals and their transmission to humans, it is important to consider the vast environmental 'resistome', the selective pathways underlying the emergence of antibacterial resistance and how we can prepare answers for tomorrow.

  8. Antibacterial triterpenoids from Melia toosendan

    Directory of Open Access Journals (Sweden)

    Qin Zhu

    2015-01-01

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

  9. Antibacterial activity of ethanolic extracts of some moss species

    Directory of Open Access Journals (Sweden)

    Karpiński Tomasz M.

    2017-09-01

    Full Text Available Introduction: For centuries, mosses have been used in traditional medicine due to their antibacterial, antifungal, and antiviral activities. Objective: The present study was designed to evaluate the antibacterial activity of ethanolic extracts obtained from 12 moss species: Brachythecium albicans, Bryum argenteum, Ceratodon purpureus, Dicranum scoparium, Dryptodon pulvinatus, Orthotrichum anomalum, Oxyrrhynchium hians, Plagiomnium undulatum, Polytrichum juniperinum, P. piliferum, Schistidium crassipilum, and Syntrichia ruralis. Methods: The antimicrobial activity of extracts was investigated against three Gram(+ bacteria (Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pyogenes and two Gram(- bacteria (Escherichia coli and Klebsiella pneumoniae, using the agar disc-diffusion method. Results: The high activity against all investigated bacteria was determined for extracts of D. pulvinatus, P. undulatum, B. argenteum, S. crassipilum, O. anomalum (mean inhibition zone: 11.3-13.1 mm and to a lesser extent in the case of D. scoparium (8.3 mm. Extracts from P. juniperinum and P. piliferum showed activity only against Gram-positive bacteria, with an inhibition zone from 7.3 to 9.7 mm. Four species: B. albicans, C. purpureus, O. hians, and S. ruralis had not antibacterial properties. Conclusions: The obtained results indicate that mosses could be a significant source of antibacterial agents. For the first time, we presented antibacterial activity of ethanolic extracts from S. crassipilum and O. anomalum.

  10. Synthesis and antibacterial activity of novel enolphosphate derivatives.

    Science.gov (United States)

    Grison, Claude; Barthes, Nicolas; Finance, Chantal; Duval, Raphael E

    2010-10-01

    A new class of enolphosphates derivatives, the 1-alkenyldiphosphates, was designed and a rapid and efficient synthesis for these compounds was developed. These new molecules showed interesting in vitro antibacterial activities (MIC) against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative pathogens including Pseudomonas aeruginosa and Escherichia coli. 2010 Elsevier Inc. All rights reserved.

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

    African Journals Online (AJOL)

    2018-02-23

    Feb 23, 2018 ... 2018 Nigerian Journal of Clinical Practice | Published by Wolters Kluwer ... Objective: The aim of this study was to evaluate the antibacterial surface .... glass ionomer cement. ..... resin containing antibacterial monomer MDPB.

  12. Substituted Hydroxyapatites with Antibacterial Properties

    Directory of Open Access Journals (Sweden)

    Joanna Kolmas

    2014-01-01

    Full Text Available Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency.

  13. Substituted Hydroxyapatites with Antibacterial Properties

    Science.gov (United States)

    Kolmas, Joanna; Groszyk, Ewa; Kwiatkowska-Różycka, Dagmara

    2014-01-01

    Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency. PMID:24949423

  14. Design and synthesis of novel N-benzylidenesulfonohydrazide inhibitors of MurC and MurD as potential antibacterial agents.

    Science.gov (United States)

    Frlan, Rok; Kovac, Andreja; Blanot, Didier; Gobec, Stanislav; Pecar, Slavko; Obreza, Ales

    2008-01-11

    A series of novel N-benzylidenesulfonohydrazide compounds were designed and synthesized as inhibitors of UDP-N-acetylmuramic acid: L-alanine ligase (MurC) and UDP-N-acetylmuramoyl-L-alanine: D-glutamate ligase (MurD) from E. coli, involved in the biosynthesis of bacterial cell-walls. Some compounds possessed inhibitory activity against both enzymes with IC(50) values as low as 30 microM. In addition, a new, one-pot synthesis of amidobenzaldehydes is reported.

  15. Silver Nanoparticles as Potential Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Gianluigi Franci

    2015-05-01

    Full Text Available Multi-drug resistance is a growing problem in the treatment of infectious diseases and the widespread use of broad-spectrum antibiotics has produced antibiotic resistance for many human bacterial pathogens. Advances in nanotechnology have opened new horizons in nanomedicine, allowing the synthesis of nanoparticles that can be assembled into complex architectures. Novel studies and technologies are devoted to understanding the mechanisms of disease for the design of new drugs, but unfortunately infectious diseases continue to be a major health burden worldwide. Since ancient times, silver was known for its anti-bacterial effects and for centuries it has been used for prevention and control of disparate infections. Currently nanotechnology and nanomaterials are fully integrated in common applications and objects that we use every day. In addition, the silver nanoparticles are attracting much interest because of their potent antibacterial activity. Many studies have also shown an important activity of silver nanoparticles against bacterial biofilms. This review aims to summarize the emerging efforts to address current challenges and solutions in the treatment of infectious diseases, particularly the use of nanosilver antimicrobials.

  16. Silver nanoparticles as potential antibacterial agents.

    Science.gov (United States)

    Franci, Gianluigi; Falanga, Annarita; Galdiero, Stefania; Palomba, Luciana; Rai, Mahendra; Morelli, Giancarlo; Galdiero, Massimiliano

    2015-05-18

    Multi-drug resistance is a growing problem in the treatment of infectious diseases and the widespread use of broad-spectrum antibiotics has produced antibiotic resistance for many human bacterial pathogens. Advances in nanotechnology have opened new horizons in nanomedicine, allowing the synthesis of nanoparticles that can be assembled into complex architectures. Novel studies and technologies are devoted to understanding the mechanisms of disease for the design of new drugs, but unfortunately infectious diseases continue to be a major health burden worldwide. Since ancient times, silver was known for its anti-bacterial effects and for centuries it has been used for prevention and control of disparate infections. Currently nanotechnology and nanomaterials are fully integrated in common applications and objects that we use every day. In addition, the silver nanoparticles are attracting much interest because of their potent antibacterial activity. Many studies have also shown an important activity of silver nanoparticles against bacterial biofilms. This review aims to summarize the emerging efforts to address current challenges and solutions in the treatment of infectious diseases, particularly the use of nanosilver antimicrobials.

  17. Cost-effectiveness and pricing of antibacterial drugs.

    Science.gov (United States)

    Verhoef, Talitha I; Morris, Stephen

    2015-01-01

    Growing resistance to antibacterial agents has increased the need for the development of new drugs to treat bacterial infections. Given increasing pressure on limited health budgets, it is important to study the cost-effectiveness of these drugs, as well as their safety and efficacy, to find out whether or not they provide value for money and should be reimbursed. In this article, we systematically reviewed 38 cost-effectiveness analyses of new antibacterial agents. Most studies showed the new antibacterial drugs were cost-effective compared to older generation drugs. Drug pricing is a complicated process, involving different stakeholders, and has a large influence on cost-effectiveness. Value-based pricing is a method to determine the price of a drug at which it can be cost-effective. It is currently unclear what the influence of value-based pricing will be on the prices of new antibacterial agents, but an important factor will be the definition of 'value', which as well as the impact of the drug on patient health might also include other factors such as wider social impact and the health impact of disease. © 2015 The Authors. Chemical Biology & Drug Design Published by John Wiley & Sons Ltd.

  18. Antibacterial activity of Artocarpus heterophyllus.

    Science.gov (United States)

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

    2003-07-01

    The crude methanolic extracts of the stem and root barks, stem and root heart-wood, leaves, fruits and seeds of Artocarpus heterophyllus and their subsequent partitioning with petrol, dichloromethane, ethyl acetate and butanol gave fractions that exhibited a broad spectrum of antibacterial activity. The butanol fractions of the root bark and fruits were found to be the most active. None of the fractions were active against the fungi tested.

  19. Human-use antibacterial residues in the natural environment of China: implication for ecopharmacovigilance.

    Science.gov (United States)

    Wang, Jun; He, Bingshu; Hu, Xiamin

    2015-06-01

    Antibacterial residues in the natural environment have been of increasing concern due to their impact on bacteria resistance development and toxicity to natural communities and ultimately to public health. China is a large country with high production and consumption of antibacterials for its population growth and economic development in recent years. In this article, we summarized the current situation of human-use antibacterial pollution in Chinese water (wastewaters, natural and drinking waters) and solid matrices (sludge, sediment, and soil) reported in 33 peer-reviewed papers. We found that, although there are adequate wastewater treatment systems in China, human-use antibacterial residues in the natural environment were reported almost throughout the whole country. Three most frequently prescribed classes of antibacterials in China, including quinolones, macrolides, and β-lactam, were also the predominant classes of residues in Chinese environment, manifested as the high concentration and detection frequency. In view of this alarming situation, we have presented that ecopharmacovigilance (EPV) might be implemented in the antibacterial drug administration of China, as the active participation of the pharmaceutical industry and drug regulatory authorities from the diffuse source of antibacterial pollution. Considering EPV experience of developed countries together with the actual conditions of China, we have identified some approaches that can be taken, including:• Focus on education;• Further strengthening and persevering the antibacterial stewardship strategies and pharmaceutical take-back programs in China;• Designing greener antibacterials with better degradability in the environment;• Implementing environmental risk assessment prior to launch of new drugs;• Strengthening collaboration in EPV-related areas.

  20. Antibacterial activity of combined medicinal plants extract against multiple drug resistant strains

    Directory of Open Access Journals (Sweden)

    Rafiqul Islam

    2015-06-01

    Full Text Available Objective: To find out the combined antibacterial efficacy of Aegle marmelos, Aphanamixis polystachya, Cuscuta reflexa and Aesclynomene indica against bacterial pathogens. Methods: Antibacterial potency of combined plant extracts has been tested against Bacillus subtilis IFO 3026, Sarcina lutea IFO 3232, Xanthomonas campestris IAM 1671, Escherichia coli IFO 3007, Klebsiella pneumoniae ATTC 10031, Proteus vulgaris MTCC 321 and Pseudomonas denitrificans KACC 32026 by disc diffusion assay. Commercially available standard antibiotic discs were also used to find out antibiotic resistance pattern of test organisms. Results: Among the test organisms, Escherichia coli, Proteus vulgaris, Klebsiella pneumoniae and Proteus denitrificans showed resistance against multiple commercially available antibiotics. On the other hand, these multiple drug resistant organisms showed susceptibility against combined plant extracts. Conclusions: These combined plants extracts showed synergistic antibacterial activity and could lead to new antibacterial drug designing.

  1. Fast Screening of Antibacterial Compounds from Fusaria

    DEFF Research Database (Denmark)

    Sondergaard, Teis Esben; Fredborg, Marlene; Christensen, Ann-Maria Oppenhagen

    2016-01-01

    Bio-guided screening is an important method to identify bioactive compounds from fungi. In this study we applied a fast digital time-lapse microscopic method for assessment of the antibacterial properties of secondary metabolites from the fungal genus Fusarium. Here antibacterial effects could...

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

    African Journals Online (AJOL)

    SERVER

    2007-10-18

    Oct 18, 2007 ... The toxigenesis of one Penicillium aurantiogriseum and one Penicillium viridicatum isolates was investigated. Sterile culture filtrates of both fungi had a clear antibacterial effect only against Bacillus subtilis. The effect on B. subtilis varied with amount of filtrate used and temperature. The antibacterial.

  3. What makes a natural clay antibacterial?

    Science.gov (United States)

    Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Port-Peterson, Amisha T.

    2011-01-01

    Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (2+ solubility.

  4. Antibacterial activity of selected Myanmar medicinal plants

    International Nuclear Information System (INIS)

    Nwe Yee Win; Nyunt Wynn; Mar Mar Nyein; Win Myint; Saw Hla Myint; Myint Khine

    2001-01-01

    Thirteen plants which are traditionally used for the treatment of dysentery and diarrhoea in Myanmar were selected and tested for antibacterial activity by using agar disc diffusion technique. Polar and nonpolar solvents were employed for extraction of plants. The minimum inhibitory concentration (MIC) of the extracts with the most significant predominant activity were evaluated by plate dilution method. The plants Eugenia jambolana, Quisqualis indica, Leucaena glauca and Euphorbia splendens var. 1 were found to show significant antibacterial activity. It was also observed that extracts using nonpolar solvents did not show any antibacterial activity and extracts using polar solvents showed antibacterial activity on tested bacteria, indicating that the active chemical compound responsible for the antibacterial action must be a polar soluble compound. (author)

  5. Antibacterial activity of baking soda.

    Science.gov (United States)

    Drake, D

    1997-01-01

    The antibacterial activity of baking soda (sodium bicarbonate) was assessed using three different experimental approaches. Standard minimum inhibitory concentration analyses revealed substantial inhibitory activity against Streptococcus mutans that was not due to ionic strength or high osmolarity. Short-term exposure assays showed significant killing of bacterial suspensions when baking soda was combined with the detergent sodium dodecylsulfate. Multiple, brief exposures of sucrose-colonized S mutans to baking soda and sodium dodecylsulfate caused statistically significant decreases in numbers of viable cells. Use of oral health care products with high concentrations of baking soda could conceivably result in decreased levels of cariogenic S mutans in saliva and plaque.

  6. Plasmonic gold nanoparticles modified titania nanotubes for antibacterial application

    International Nuclear Information System (INIS)

    Li, Jinhua; Zhou, Huaijuan; Qian, Shi; Liu, Ziwei; Feng, Jingwei; Jin, Ping; Liu, Xuanyong

    2014-01-01

    Close-packed TiO 2 nanotube arrays are prepared on metallic Ti surface by electrochemical anodization. Subsequently, by magnetron sputtering, Au nanoparticles are coated onto the top sidewall and tube inwall. The Au@TiO 2 systems can effectively kill Staphylococcus aureus and Escherichia coli in darkness due to the existence of Au nanoparticles. On the basis of classical optical theories, the antibacterial mechanism is proposed from the perspective of localized surface plasmon resonance. Respiratory electrons of bacterial membrane transfer to Au nanoparticles and then to TiO 2 , which makes bacteria steadily lose electrons until death. This work provides insights for the better understanding and designing of noble metal nanoparticles-based plasmonic heterostructures for antibacterial application.

  7. Proteolytic activity of Escherichia coli oligopeptidase B against proline-rich antimicrobial peptides

    DEFF Research Database (Denmark)

    Mattiuzzo, Maura; De Gobba, Cristian; Runti, Giulia

    2014-01-01

    Oligopeptidase B (OpdB) is a serine peptidase widespread among bacteria and protozoa that has emerged as a virulence factor despite its function has not yet been precisely established. By using an OpdB-overexpressing Escherichia coli strain, we found that the overexpressed peptidase makes...

  8. Myosin-1E interacts with FAK proline-rich region 1 to induce fibronectin-type matrix

    DEFF Research Database (Denmark)

    Heim, Joel B; Squirewell, Edwin J; Neu, Ancilla

    2017-01-01

    Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase involved in development and human disease, including cancer. It is currently thought that the four-point one, ezrin, radixin, moesin (FERM)-kinase domain linker, which contains autophosphorylation site tyrosine (Y) 397, is not required...... for in vivo FAK function until late midgestation. Here, we directly tested this hypothesis by generating mice with FAK Y397-to-phenylalanine (F) mutations in the germline. We found that Y397F embryos exhibited reduced mesodermal fibronectin (FN) and osteopontin expression and died during mesoderm development...... and other FN-type matrix in both mouse embryonic fibroblasts and human melanoma. Our data support a model in which FAK Y397 autophosphorylation is required for FAK function in vivo and is positively regulated by MYO1E....

  9. Folding machineries displayed on a cation-exchanger for the concerted refolding of cysteine- or proline-rich proteins

    Directory of Open Access Journals (Sweden)

    Lee Dae-Hee

    2009-03-01

    Full Text Available Abstract Background Escherichia coli has been most widely used for the production of valuable recombinant proteins. However, over-production of heterologous proteins in E. coli frequently leads to their misfolding and aggregation yielding inclusion bodies. Previous attempts to refold the inclusion bodies into bioactive forms usually result in poor recovery and account for the major cost in industrial production of desired proteins from recombinant E. coli. Here, we describe the successful use of the immobilized folding machineries for in vitro refolding with the examples of high yield refolding of a ribonuclease A (RNase A and cyclohexanone monooxygenase (CHMO. Results We have generated refolding-facilitating media immobilized with three folding machineries, mini-chaperone (a monomeric apical domain consisting of residues 191–345 of GroEL and two foldases (DsbA and human peptidyl-prolyl cis-trans isomerase by mimicking oxidative refolding chromatography. For efficient and simple purification and immobilization simultaneously, folding machineries were fused with the positively-charged consecutive 10-arginine tag at their C-terminal. The immobilized folding machineries were fully functional when assayed in a batch mode. When the refolding-facilitating matrices were applied to the refolding of denatured and reduced RNase A and CHMO, both of which contain many cysteine and proline residues, RNase A and CHMO were recovered in 73% and 53% yield of soluble protein with full enzyme activity, respectively. Conclusion The refolding-facilitating media presented here could be a cost-efficient platform and should be applicable to refold a wide range of E. coli inclusion bodies in high yield with biological function.

  10. Antibacterial Activity of Silicate Bioceramics

    Institute of Scientific and Technical Information of China (English)

    HU Sheng; NING Congqin; ZHOU Yue; CHEN Lei; LIN Kaili; CHANG Jiang

    2011-01-01

    Four kinds of pure silicate ceramic particles, CaSiO3, Ca3SiO5, bredigite and akermanite were prepared and their bactericidal effects were systematically investigated. The phase compositions of these silicate ceramics were characterized by XRD. The ionic concentration meas urement revealed that the Calcium (Ca) ion concentration were relatively higher in Ca3SiO5 and bredigite, and much lower in CaSiO3 and akermanite. Accordingly, the pH values of the four silicate ceramics extracts showed a positive correlation with the particle concentrations. Meanwhile, by decreasing the particle size, higher Ca ion concentrations can be achieved, leading to the increase of aqueous pH value as well. In summary, all of the four silicate ceramics tested in our study showed antibacterial effect in a dose-dependent manner. Generally, the order of their antibacterial activity against E.coli from strong to weak is Ca3SiO5, bredigite, CaSiO3 and akermanite.

  11. Antibacterial-induced nephrotoxicity in the newborn.

    Science.gov (United States)

    Fanos, V; Cataldi, L

    1999-03-01

    Antibacterials are the primary cause of drug-induced kidney disease in all age groups and these agents bring about renal damage by 2 main mechanisms, namely, direct and immunologically mediated. For some antibacterials (aminoglycosides and vancomycin) nephrotoxicity is very frequent but generally reversible upon discontinuation of the drug. However, the development of acute renal failure with these agents is possible and its incidence in the newborn seems to be increasing. Antibacterials are very often used in the neonatal period especially in very low birthweight neonates. The role of neonatal age in developing nephrotoxicity has still to be defined. Since the traditional laboratory parameters of nephrotoxicity are abnormal only in the presence of substantial renal damage, the identification of early non-invasive markers of the renal damage (urinary microglobulins, enzymes and growth factors) is of importance. Aminoglycosides and glycopeptides are still frequently used, either alone or in combination, despite their low therapeutic index. Numerous factors intervene in bringing about the kidney damage induced by these 2 classes of antibacterials, such as factors related to the antibacterial itself and others related to the associated pathology as well as pharmacological factors. Nephrotoxicity can be caused by the beta-lactams and related compounds. Their potential to cause nephrotoxicity decreases in the order: carbapenems > cephalosporins > penicillins > monobactams. Third generation cephalosporins are frequently used in neonates. However, they are well tolerated compounds at the renal level. The nephrotoxicity of other classes of antibacterials is not discussed either because they are only used in neonates in exceptional circumstances, for example, chloramphenicol and cotrimoxazole (trimethoprim-sulfamethoxazole) or are not associated with significant nephrotoxicity, for example macrolides, clindamicin, quinolones, rifampicin (rifampin) and metronidazole

  12. Chitosan coating as an antibacterial surface for biomedical applications.

    Directory of Open Access Journals (Sweden)

    Mélanie D'Almeida

    Full Text Available A current public health issue is preventing post-surgical complications by designing antibacterial implants. To achieve this goal, in this study we evaluated the antibacterial activity of an animal-free chitosan grafted onto a titanium alloy.Animal-free chitosan binding on the substrate was performed by covalent link via a two-step process using TriEthoxySilylPropyl Succinic Anhydride (TESPSA as the coupling agent. All grafting steps were studied and validated by means of X-ray Photoelectron Spectroscopy (XPS, Time-of-Flight secondary ion mass spectrometry (ToF-SIMS analyses and Dynamic-mode Secondary Ion Mass Spectrometry (DSIMS. The antibacterial activity against Escherichia coli and Staphylococcus aureus strains of the developed coating was assessed using the number of colony forming units (CFU.XPS showed a significant increase in the C and N atomic percentages assigned to the presence of chitosan. A thick layer of polymer deposit was detected by ToF-SIMS and the results obtained by DSIMS measurements are in agreement with ToF-SIMS and XPS analyses and confirms that the coating synthesis was a success. The developed coating was active against both gram negative and gram positive tested bacteria.The success of the chitosan immobilization was proven using the surface characterization techniques applied in this study. The coating was found to be effective against Escherichia coli and Staphylococcus aureus strains.

  13. Optical control of antibacterial activity

    Science.gov (United States)

    Velema, Willem A.; van der Berg, Jan Pieter; Hansen, Mickel J.; Szymanski, Wiktor; Driessen, Arnold J. M.; Feringa, Ben L.

    2013-11-01

    Bacterial resistance is a major problem in the modern world, stemming in part from the build-up of antibiotics in the environment. Novel molecular approaches that enable an externally triggered increase in antibiotic activity with high spatiotemporal resolution and auto-inactivation are highly desirable. Here we report a responsive, broad-spectrum, antibacterial agent that can be temporally activated with light, whereupon it auto-inactivates on the scale of hours. The use of such a ‘smart’ antibiotic might prevent the build-up of active antimicrobial material in the environment. Reversible optical control over active drug concentration enables us to obtain pharmacodynamic information. Precisely localized control of activity is achieved, allowing the growth of bacteria to be confined to defined patterns, which has potential for the development of treatments that avoid interference with the endogenous microbial population in other parts of the organism.

  14. SYNTHESIS, STRUCTURAL AND ANTIBACTERIAL STUDY OF ...

    African Journals Online (AJOL)

    diffraction, thermogravimetric analysis, scanning electron microscopy, atomic ... possess interesting biological properties like antibacterial properties [4-7]. ... compounds used for treating mental illness, epilepsy, and nicotine addiction [9, 10].

  15. Antibacterial activity of Mangifera indica L

    African Journals Online (AJOL)

    Dr Steve Ogbonnia

    2011-11-09

    Nov 9, 2011 ... specimens like blood, urine, catheter, stool and pus. Antibacterial ... In addition to this problem, antibiotics ... number of multi-drug resistant microbial strains and the appearance of ... to fine powder and stored in airtight bottles.

  16. Topical Antibacterials and Global Challenges on Resistance ...

    African Journals Online (AJOL)

    skin infections can be easily treated with topical antibacterial medication that is available over the counter or by ... infection in minor cut or burn, eyes and ear infection [5]. .... Sensitive/dry skin ... includes both oral and topical antibiotics, but.

  17. Development and antibacterial performance of silver nanoparticles ...

    Indian Academy of Sciences (India)

    Antibacterial activity; in situ fabrication; polyester fabric; silver nanoparticle. 1. Introduction ... transmitter found in central nervous system which has a vital role in human health. .... finished fabric were higher due to the presence of higher.

  18. Antibacterial and haematological activity of Moringa oleifera ...

    African Journals Online (AJOL)

    The phytochemical, antibacterial and haematologic activity of aqueous seed extract of Moringa oleifera (Moringaceae) were evaluated. Phytochemicals such as tannins, carbohydrates, alkaloids, cardiac glycosides, anthraquinones and flavonoids in low, moderate and high concentrations were present in the seeds.

  19. Antibacterial and haematological activity of Moringa oleifera ...

    African Journals Online (AJOL)

    ADEYEYE

    6Department of Human Anatomy, College of Medical Sciences, University of Maiduguri, Borno ... Keywords: Antibacterial effect, Haematology, Moringa olifera, Phytochemical analysis, Wistar albino rats. ..... Moringa oleifera: A food plant with.

  20. Investigation into the prevalence and antibacterial susceptibility ...

    African Journals Online (AJOL)

    Investigation into the prevalence and antibacterial susceptibility patterns of aeromonas and plesiomonas species isolated from children with diarrhoea in Amuwo-Odofin and Surulere Local Government areas of Lagos, Nigeria.

  1. Antibacterial Titanium Produced Using Selective Laser Melting

    Science.gov (United States)

    Macpherson, Andrew; Li, Xiaopeng; McCormick, Paul; Ren, Ling; Yang, Ke; Sercombe, Timothy B.

    2017-12-01

    Titanium and titanium alloys used in current medical and dental applications do not possess antibacterial properties, and therefore, postoperative infection remains a significant risk. Recently, the addition of silver and copper to conventional biomaterials has been shown to produce a material with good antibacterial properties. In this article, we investigate selective laser melting as a method of producing antibacterial Ti-6Al-4V containing elemental additions of Cu or Ag. The addition of Ag had no effect on the microstructure or strength, but it did result in a 300% increase in the ductility of the alloy. In contrast, the addition of Cu resulted in an increase in strength but in a decrease in ductility, along with a change in the structure of the material. The Cu-containing alloy also showed moderate antibacterial properties and was superior to the Ag-containing alloy.

  2. Acute exacerbations of chronic bronchitis: a pharmacoeconomic review of antibacterial use.

    Science.gov (United States)

    Morris, Stephen; Anderson, Pippa; Irwin, Debra E

    2002-01-01

    Chronic bronchitis is a common problem affecting a large proportion of the adult population. People with chronic bronchitis are subject to recurrent attacks of bronchial inflammation called acute exacerbations of chronic bronchitis (AECBs). In patients with AECBs, symptoms may worsen due to a bacterial infection; the exacerbation is then known as an acute bacterial exacerbation of chronic bronchitis (ABECB). ABECBs are thought to be controllable through the use of antibacterial agents. In this paper we review current evidence on the cost of chronic bronchitis and AECBs, the cost effectiveness of antibacterials in the management of ABECB, and the factors that may affect the cost-effectiveness of antibacterials in the management of ABECB. We find that the number of economic evaluations conducted in this area is small. Of the few economic evaluations that have been conducted there has been only one prospective economic evaluation based on a clinical trial. The remainder are simple decision analysis-based modelling studies or retrospective database studies. Our principle findings are as follows: a key factor affecting the cost-effective use of antibacterials in the management of ABECB is the definitive diagnosis of the condition. Unfortunately, diagnosing a bacterial cause of an AECB is difficult, which presents problems in ensuring that antibacterials are not prescribed unnecessarily;current evidence suggests but does not prove that use of more effective but more costly first-line antibacterials may be relatively cost effective and may minimise overall expenditure by reducing the high costs associated with treatment failure;chronic bronchitis and AECB have a significant and negative physical and psychological effect on health-related quality of life. In conclusion, the small number of economic evaluations conducted in this area, coupled with the nature of the design of these studies, precludes a definitive statement recommending which specific antibacterial should be

  3. The characterization of the antibacterial efficacy of an electrically activated silver ion-based surface system

    Science.gov (United States)

    Shirwaiker, Rohan A.

    There have been growing concerns in the global healthcare system about the eradication of pathogens in hospitals and other health-critical environments. The problem has been aggravated by the overuse of antibiotics and antimicrobial agents leading to the emergence of antibiotic-resistant superbugs such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) which are difficult to kill. Lower immunity of sick patients coupled with the escalating concurrent problem of antibiotic-resistant pathogens has resulted in increasing incidences of hospital acquired (nosocomial) infections. There is an immediate need to control the transmission of such infections, primarily in healthcare environments, by creating touch-contact and work surfaces (e.g., door knobs, push plates, countertops) that utilize alternative antibacterial materials like the heavy metal, silver. Recent research has shown that it is silver in its ionic (Ag+ ) and not elemental form that is antibacterial. Thus, silver-based antibacterial surfaces have to release silver ions directly into the pathogenic environment (generally, an aqueous media) in order to be effective. This dissertation presents the study and analysis of a new silver-based surface system that utilizes low intensity direct electric current (LIDC) for generation of silver ions to primarily inhibit indirect contact transmission of infections. The broader objective of this research is to understand the design, and characterization of the electrically activated silver ion-based antibacterial surface system. The specific objectives of this dissertation include: (1) Developing a comprehensive system design, and identifying and studying its critical design parameters and functional mechanisms. (2) Evaluating effects of the critical design parameters on the antibacterial efficacy of the proposed surface system. (3) Developing a response surface model for the surface system performance. These objectives are

  4. Design junctions

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik

    2012-01-01

    . This case study illustrates how dominant regimes of practice, established through the conception of pathogen bacteria and antibacterial treatments and disinfection, are now creating signals that call into question fundamental design of hygiene practices. By examining the epistemic assumptions of scientific...

  5. Multiaction antibacterial nanofibrous membranes fabricated by electrospinning: an excellent system for antibacterial applications

    International Nuclear Information System (INIS)

    Wu Yiguang; Jia Weijie; An Qi; Li Guangtao; Liu Yuanfeng; Chen Jinchun

    2009-01-01

    In this paper, novel multiaction antibacterial nanofibrous membranes containing apatite, Ag, AgBr and TiO 2 as four active components were fabricated by an electrospinning technique. In this antibacterial membrane, each component serves a different function: the hydroxyapatite acts as the adsorption material for capturing bacteria, the Ag nanoparticles act as the release-active antibacterial agent, the AgBr nanoparticles act as the visible sensitive and release-active antibacterial agent, and the TiO 2 acts as the UV sensitive antibacterial material and substrate for other functional components. Using E. coli as the typical testing organism, such multicomponent membranes exhibit excellent antimicrobial activity under UV light, visible light or in a dark environment. The significant antibacterial properties may be due to the synergetic action of the four major functional components, and the unique porous structure and high surface area of the nanofibrous membrane. It takes only 20 min for the bacteria to be completely (99.9%) destroyed under visible light. Even in a dark environment, about 50 min is enough to kill all of the bacteria. Compared to the four component system in powder form reported previously, the addition of the electrospun membrane could significantly improve the antibacterial inactivation of E. coli under the same evaluation conditions. Besides the superior antimicrobial capability, the permanence of the antibacterial activity of the prepared free-standing membranes was also demonstrated in repeated applications.

  6. ANTIBACTERIAL EFFECTS OF FRESH AND PRESERVED ROYAL JELLY

    Directory of Open Access Journals (Sweden)

    Zinka Maksimović

    2013-10-01

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

  7. Separation and Identification of Four New Compounds with Antibacterial Activity from Portulaca oleracea L.

    Directory of Open Access Journals (Sweden)

    Xia Lei

    2015-09-01

    Full Text Available The Portulaca oleracea L. (P. oleracea has been used to treat bacillary dysentery for thousands of years in China. Pharmacology studies on P. oleracea have also showed its significant antibacterial effects on the enteropathogenic bacteria, which might reveal the treatment of P. oleracea in cases of bacillary dysentery to some extent. To date, however, the therapeutic basis of P. oleracea treating on bacillary dysentery remains unknown. We determined the antibacterial effective fraction of P. oleracea in a previous study. The current study, which is based on our previous study, was first designed to isolate, identify and screen antibacterial active constituents from P. oleracea. As a result, four new compounds (1–4, portulacerebroside B (1, portulacerebroside C (2, portulacerebroside D (3 and portulaceramide A (4 along with five known compounds (5–9 were isolated, and structures were established by their physico-chemical constants and spectroscopic analysis. The antibacterial activities against common enteropathogenic bacteria were evaluated for all compounds and the new compounds 1–4 showed significant antibacterial effect on enteropathogenic bacteria in vitro, which might contribute to revealing the treatment of P. oleracea in cases of bacillary dysentery.

  8. Separation and Identification of Four New Compounds with Antibacterial Activity from Portulaca oleracea L.

    Science.gov (United States)

    Lei, Xia; Li, Jianmin; Liu, Bin; Zhang, Ning; Liu, Haiyang

    2015-09-10

    The Portulaca oleracea L. (P. oleracea) has been used to treat bacillary dysentery for thousands of years in China. Pharmacology studies on P. oleracea have also showed its significant antibacterial effects on the enteropathogenic bacteria, which might reveal the treatment of P. oleracea in cases of bacillary dysentery to some extent. To date, however, the therapeutic basis of P. oleracea treating on bacillary dysentery remains unknown. We determined the antibacterial effective fraction of P. oleracea in a previous study. The current study, which is based on our previous study, was first designed to isolate, identify and screen antibacterial active constituents from P. oleracea. As a result, four new compounds (1-4), portulacerebroside B (1), portulacerebroside C (2), portulacerebroside D (3) and portulaceramide A (4) along with five known compounds (5-9) were isolated, and structures were established by their physico-chemical constants and spectroscopic analysis. The antibacterial activities against common enteropathogenic bacteria were evaluated for all compounds and the new compounds 1-4 showed significant antibacterial effect on enteropathogenic bacteria in vitro, which might contribute to revealing the treatment of P. oleracea in cases of bacillary dysentery.

  9. antibacterial properties of calyx, stem bark and root of hibiscus ...

    African Journals Online (AJOL)

    HS) were tested for their antibacterial activities. The root of the plant exhibited marked antibacterial activity against gram positive and gram negative organisms of Klebsiella pneumonia, Escherichia coli, Proteus spp., Pseudomonas aureginosa, ...

  10. The antibacterial potential of the seaweeds (Rhodophyceae) of the ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-20

    Sep 20, 2010 ... The antibacterial activity of extracts from 26 marine Rhodophyceae (8 Ceramiales, 7 Gelidiales, 9 ... seaweed extracts as a source of antibacterial compounds. ... Macroalgae are a rich source of natural bioactive products.

  11. Antibacterial action of an aqueous grape seed polyphenolic extract

    African Journals Online (AJOL)

    Jane

    2011-07-06

    Jul 6, 2011 ... The potential of a polyphenolic grape seed extract for use as a natural antibacterial agent was ... electrospray ionisation-mass spectrometry; PBS, phosphate .... The antibacterial tests were carried out by disc diffusion method.

  12. Tunable, antibacterial activity of silicone polyether surfactants.

    Science.gov (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A

    2015-08-01

    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Targeted Drug-Carrying Bacteriophages as Antibacterial Nanomedicines▿

    OpenAIRE

    Yacoby, Iftach; Bar, Hagit; Benhar, Itai

    2007-01-01

    While the resistance of bacteria to traditional antibiotics is a major public health concern, the use of extremely potent antibacterial agents is limited by their lack of selectivity. As in cancer therapy, antibacterial targeted therapy could provide an opportunity to reintroduce toxic substances to the antibacterial arsenal. A desirable targeted antibacterial agent should combine binding specificity, a large drug payload per binding event, and a programmed drug release mechanism. Recently, w...

  14. MgO nanoparticles as antibacterial agent: preparation and activity

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zhen-Xing, E-mail: tangzhenxing@126.com [Department of Food Science, Anqing, Vocational and Technical College, Anqing, Anhui (China); Lv, Bin-Feng [Date Palm Research Center, King Faisal University, (Saudi Arabia)

    2014-07-15

    Bacterial pollution is a great risk for human health. Nanotechnology offers a way to develop new inorganic antibacterial agents. Nano-inorganic metal oxide has a potential to reduce bacterial contamination. MgO is an important inorganic oxide and has been widely used in many fields. Many studies have shown that MgO nanoparticles have good antibacterial activity. Therefore, in this paper, the main synthesis methods, antibacterial activity and antibacterial mechanisms of MgO nanoparticles are reviewed. (author)

  15. MgO nanoparticles as antibacterial agent: preparation and activity

    International Nuclear Information System (INIS)

    Tang, Zhen-Xing; Lv, Bin-Feng

    2014-01-01

    Bacterial pollution is a great risk for human health. Nanotechnology offers a way to develop new inorganic antibacterial agents. Nano-inorganic metal oxide has a potential to reduce bacterial contamination. MgO is an important inorganic oxide and has been widely used in many fields. Many studies have shown that MgO nanoparticles have good antibacterial activity. Therefore, in this paper, the main synthesis methods, antibacterial activity and antibacterial mechanisms of MgO nanoparticles are reviewed. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-04-01

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

  17. Antibacterial activity of indium curcumin and indium diacetylcurcumin

    African Journals Online (AJOL)

    Studies on curcumin, the principal element of turmeric powder, have demonstrated several biological actions such as antibacterial activity. Evaluation of new analogs or new compounds of curcumin for their antibacterial effect is interesting for researchers. In this in vitro study, we attempted to test the antibacterial activity of ...

  18. Antibacterial activity of some selected plants traditionally used as ...

    African Journals Online (AJOL)

    SAM

    2014-03-26

    Mar 26, 2014 ... K. Womens'College, Kongkhampat,Nambol-795134, Manipur, India. 2Department of Life Science and Bioinformatics, Assam University, Silchar, ... antibacterial activity. The study revealed that all extracts show varied degree of antibacterial activity against the tested bacterial pathogens. The antibacterial ...

  19. Antibacterial resistance leadership group: open for business.

    Science.gov (United States)

    Chambers, Henry F; Bartlett, John G; Bonomo, Robert A; Chiou, Christine; Cosgrove, Sara E; Cross, Heather R; Daum, Robert S; Downing, Michele; Evans, Scott R; Knisely, Jane; Kreiswirth, Barry N; Lautenbach, Ebbing; Mickley, Brenda S; Patel, Robin; Pettigrew, Melinda M; Rodvold, Keith A; Spellberg, Brad; Fowler, Vance G

    2014-06-01

    Funded by the National Institute of Allergy and Infectious Diseases, the Antibacterial Resistance Leadership Group (ARLG) is tasked with developing a clinical research agenda and conducting clinical studies to address the growing public health threat of antibacterial resistance. The ARLG has identified 4 high-priority areas of research: infections caused by gram-negative bacteria, infections caused by gram-positive bacteria, antimicrobial stewardship and infection prevention, and diagnostics. The ARLG will be accepting proposals from the scientific community for clinical research that addresses 1 or more of these high-priority areas. These studies should have the potential to transform medical practice and be unlikely to occur without ARLG support. The purpose of this article is to make interested parties aware of clinical research opportunities made available by ARLG and to encourage submission of clinical research proposals that address the problem of antibacterial resistance.

  20. Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Raheleh Ghanbari

    2012-12-01

    Full Text Available Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp. were evaluated. Papain hydrolysis showed the highest DH value (89.44%, followed by alcalase hydrolysis (83.35%. Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.

  1. Antibacterial Compounds from Red Seaweeds (Rhodophyta

    Directory of Open Access Journals (Sweden)

    Noer Kasanah

    2015-07-01

    Full Text Available Seaweeds produce great variety of metabolites benefit for human. Red seaweeds (Rhodophyta are well known as producer of phycocolloids such agar, agarose, carragenan and great variety of secondary metabolites. This review discusses the red algal secondary metabolites with antibacterial activity. The chemical constituents of red algae are steroid, terpenoid, acetogenin and dominated by halogenated compounds mainly brominated compounds. Novel compounds with intriguing skeleton are also reported such as bromophycolides and neurymenolides. In summary, red seaweeds are potential sources for antibacterial agents and can serve as lead in synthesis of new natural medicines.

  2. Phytochemical Screening and Antibacterial Activity of Cybopogon ...

    African Journals Online (AJOL)

    Similarly, the results of antibacterial activity testing of the extracts at equal disc concentration of 30@g/disc showed that E. coli was sensitive to all extracts with inhibition zone diameters of 7mm, Klebsiella spp. and Proteus spp. were sensitive to acetone extract of the plant with inhibition zone diameters of 7mm each while ...

  3. Development and antibacterial performance of silver nanoparticles ...

    Indian Academy of Sciences (India)

    Metallization is one of the finishing processes in textile treatment that can produce multifunctional effects. The present study dealt with the development of an antibacterial polyester-knitted fabric via facile and green impregnation of silver nanoparticles (SNPs). This was done by applying a polymeric foundation on the ...

  4. Antibacterial properties of polyaniline-silver films

    Czech Academy of Sciences Publication Activity Database

    Kuceková, Z.; Kašpárková, V.; Humpolíček, P.; Ševčíková, P.; Stejskal, Jaroslav

    2013-01-01

    Roč. 67, č. 8 (2013), s. 1103-1108 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GA13-08944S Institutional support: RVO:61389013 Keywords : polyaniline * silver * antibacterial properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.193, year: 2013

  5. Phytochemical Screening and Antibacterial Activities of Hibiscus ...

    African Journals Online (AJOL)

    The phytochemical properties and the antibacterial potency of rosselle (Hibiscus sabdariffa L) leaf extracts were evaluated using the cold maceration method, agar diffusion method and qualitative phytochemical analysis respectively. The methanolic extract was tested against Salmonella typhi, Escherichia coli and ...

  6. Phytochemical screening and antibacterial investigations of crude ...

    African Journals Online (AJOL)

    The objective of this research was to evaluate the presence of phytochemicals present in the different plant parts and their antibacterial activity. Methodology and results: Leaves, flowers, stem bark, immature pods and root barks were collected from Siaya, Nandi and Nakuru Counties. These were dried and ground.

  7. Antibacterial properties and preliminary phytochemical analysis of ...

    African Journals Online (AJOL)

    Partial purification (Thin Layer Chromatography) of the crude extract revealed five (5) components. Characteristics of these components were viewed by Infrared and UV/VIS spectrophotometer showing the presence of alkaloid, saponin, tannin, steroid and flavonoid. The observed antibacterial activity was believed to be due ...

  8. Synthesis and antibacterial activity screening of quaternary ...

    Indian Academy of Sciences (India)

    A series of quaternary ammonium derivatives of triazolyl pyranochromen-2-ones have been synthesized and characterized; their antibacterial potential were investigated against two gram negative (Pseudomonas aeruginosa and Escherichia coli) and two gram positive bacterial strains (Bacillus cereus and Staphylococcus ...

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

    African Journals Online (AJOL)

    Objective: The aim of this study was to evaluate the antibacterial surface pretreatment methods against Streptococcus mutans within the infected dentin surface using a tooth cavity model. Material and Methods: Seventy-two cavities were prepared on caries-free third molars (n = 8). After sterilization, teeth were inoculated ...

  10. Precursor Dependent Structural Properties and Antibacterial Activity ...

    Indian Academy of Sciences (India)

    71

    10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30 ... absorption spectroscopy, Scanning electron microscopy (SEM) and Zeta ... The antibacterial activity of the synthesized CuO were studied against human .... Sample d : Copper oxide synthesized with cupric sulphate as precursor ...... Chem.4 86.

  11. Studies on Buddleja asiatica antibacterial, antifungal, antispasmodic ...

    African Journals Online (AJOL)

    Jane

    2011-07-27

    Jul 27, 2011 ... Studies on Buddleja asiatica antibacterial, antifungal, antispasmodic and Ca. ++ ... strong cyclo-oxygenase inhibitory activities in elicited rat peritoneal ... A resting tension of 1 g was applied to each tissue and kept constant ... Statistical analysis .... through opening of VDCs, thus allowing the influx of extra.

  12. SYNERGISTIC ANTIBACTERIAL EFFECT OF STEM BARK ...

    African Journals Online (AJOL)

    userpc

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

  13. Phytochemical Screening, Antibacterial and Toxicological Activities ...

    African Journals Online (AJOL)

    The phytochemical screening, antibacterial and toxicological activities of extracts of the stem bark of Acacia senegal were investigated. The phytochemical analyses according to standard screening tests using conventional protocols revealed the presence of tannins, saponins and sterols in the stem bark of the plant.

  14. antibacterial properties and preliminary phytochemical analysis

    African Journals Online (AJOL)

    DR. AMINU

    IBDF Ministeroida Agricultura, Riode Janesio, 63pp. Edeoja, O.H., Okwu, E.D. and Mbaebie, O.B. (2005). Phytochemical constituents of some Nigerian medicinal plants. African Journal of Biotechnology. 4(7):685-688. Ekhaise, F.O. and Okoruwa, P. (2001). Antibacterial activity of Aloe vera (Aloe barbadensis) extract on.

  15. Purification, Characterization and Antibacterial Mechanism of ...

    African Journals Online (AJOL)

    Purpose: To carry out the extraction, purification and biological characterization, and assess the antibacterial activity of bacteriocin from Lactobacillus acidophilus XH1. Methods: Chloroform extraction method was used for bacteriocin extraction while characterization of bacteriocin was carried out by flat-dug well agar ...

  16. DRUG-INTERACTIONS WITH QUINOLONE ANTIBACTERIALS

    NARCIS (Netherlands)

    BROUWERS, JRBJ

    1992-01-01

    The quinolone antibacterials are prone to many interactions with other drugs. Quinolone absorption is markedly reduced with antacids containing aluminium, magnesium and/or calcium and therapeutic failure may result. Other metallic ion-containing drugs, such as sucralfate, iron salts, and zinc salts,

  17. Preparation, Characterization and Antibacterial Properties of Silver ...

    African Journals Online (AJOL)

    electron microscopy (SEM), differential scanning calorimetry (DSC), dynamic light scattering (DLS) and laser Doppler electrophoresis (LDE). The antibacterial ... silver nanoparticles. The size of the nanoparticles can be modulated by varying both chitosan MW and process conditions such as temperature and stirring speed.

  18. ANTIBACTERIAL ACTIVITIES, DFT AND QSAR STUDIES OF ...

    African Journals Online (AJOL)

    Latif Hesham4. 1Department of ... [5] and characterized, see Figure 1. In the present study, our aim is to investigate the antibacterial activity of 1 and 2. Moreover, ..... in Figure 3. The pink color parts embody the regions of negative electrostatic.

  19. Phytochemical screening and antibacterial activity of Azadiracta ...

    African Journals Online (AJOL)

    Preliminary phytochemical analysis showed that both stem bark and leaf extracts contain alkaloid, tannin, anthraquinone, flavonoid, phenols and terpenoid. The extracts of the plant demonstrated antibacterial activity due to presence of phytochemical constituents hence, the application of the decoction of leaf and stem bark ...

  20. Synthesis, spectral characterization and in vitro antibacterial ...

    African Journals Online (AJOL)

    Shafqat Nadeem

    2015-12-17

    Dec 17, 2015 ... slightly toxic and present a potential for antibacterial activity. Moreover, they ... interaction, in this paper, we describe the coordination of Pal- ladium(II) iodide with .... between steric/electrostatic property and biological activity. Table. 1 ..... properties, affinity to proteins, reactivity, toxicity, metabolic stability and ...

  1. Phytochemical screening, free radical scavenging and antibacterial ...

    African Journals Online (AJOL)

    Cassia sieberiana is a tropical plant, widely distributed throughout Sudan and Guinea savannah. It is used in traditional medicine for the treatment of malarial, cancer and stomach ache. The study was conducted to screen for phytochemicals, free radical scavenging and antibacterial potentials of the root bark.

  2. Antiproliferative and antibacterial activity evaluation of red ...

    African Journals Online (AJOL)

    Antibacterial activity of these extracts was also tested against Salmonella choleraesuis, Listeria monocytogenes and Staphylococcus aureus. All extracts were obtained from lyophilized biomass of red microalgae. Extract A was obtained using 40% ammonium sulfate precipitation and gel filtration chromatography with G-25 ...

  3. Antibacterial evaluation of Anacardium occidentale (Linn ...

    African Journals Online (AJOL)

    aghomotsegin

    has led to the seeking of new antibiotics that are effective and opens paths for the ... to evaluate the antibacterial activity of ethanol extract of the leaves and stem peels of .... radiation intensity and production of phenol compounds such as ...

  4. Evaluation of phytochemical and antibacterial properties of ...

    African Journals Online (AJOL)

    Phytochemical screening of aqueous and ethanol crude extracts of the different plant parts of Terminalia avicennioides was carried out using standard chemical evaluation methods. The antibacterial effects of aqueous and ethanol crude extracts of Terminalia avicennioides against E.coli and S.typhimurium clinical and ...

  5. Isolation, characterization and chromatography based purification of antibacterial compound isolated from rare endophytic actinomycetes Micrococcus yunnanensis

    Directory of Open Access Journals (Sweden)

    Ravi Ranjan

    2017-10-01

    Full Text Available Endophytic actinomycetes are considered as one of the relatively unexplored potential sources in search of antibiotic producer against antibiotic resistant pathogens. A potent strain isolated from Catharanthus roseus that displays antibacterial potential against antibiotic resistant human pathogen Staphylococcus aureus was characterized and designated as Micrococcus yunnanensis strain rsk5. Rsk5 is capable of producing optimum antibacterial metabolites on starch casein medium at 30 °C, pH 5 and 2% NaCl condition. The crude antibacterial agent was extracted from fermentation broth by ethyl acetate and separated by TLC using chloroform-methanol (24:1, v/v solvent system with Rf value of 0.26. It was partially purified by flash chromatography, followed by HPLC and analyzed by ultraviolet visible spectrophotometer to get absorption maxima at 208.4 nm. The ESI-MS spectra showed molecular ion peaks at m/z 472.4 [M-H], which does not match with any known antibacterial compound.

  6. Isolation, characterization and chromatography based purification of antibacterial compound isolated from rare endophytic actinomycetes Micrococcus yunnanensis.

    Science.gov (United States)

    Ranjan, Ravi; Jadeja, Vasantba

    2017-10-01

    Endophytic actinomycetes are considered as one of the relatively unexplored potential sources in search of antibiotic producer against antibiotic resistant pathogens. A potent strain isolated from Catharanthus roseus that displays antibacterial potential against antibiotic resistant human pathogen Staphylococcus aureus was characterized and designated as Micrococcus yunnanensis strain rsk5. Rsk5 is capable of producing optimum antibacterial metabolites on starch casein medium at 30 °C, pH 5 and 2% NaCl condition. The crude antibacterial agent was extracted from fermentation broth by ethyl acetate and separated by TLC using chloroform-methanol (24:1, v/v) solvent system with R f value of 0.26. It was partially purified by flash chromatography, followed by HPLC and analyzed by ultraviolet visible spectrophotometer to get absorption maxima at 208.4 nm. The ESI-MS spectra showed molecular ion peaks at m / z 472.4 [M-H], which does not match with any known antibacterial compound.

  7. Synthesis, characterization and antibacterial properties of dihydroxy quaternary ammonium salts with long chain alkyl bromides.

    Science.gov (United States)

    Liu, Wen-Shuai; Wang, Chun-Hua; Sun, Ju-Feng; Hou, Gui-Ge; Wang, Yu-Peng; Qu, Rong-Jun

    2015-01-01

    Five N-methyl-N-R-N,N-bis(2-hydroxyethyl) ammonium bromides (R = -benzyl (chloride, BNQAS), -dodecyl (C12QAS), -tetradecyl (C14QAS), -hexadecyl (C16QAS), -octadecyl (C18QAS)) were prepared based on N-methyldiethanolamine (MDEA) and halohydrocarbon. Five QAS were characterized by FTIR, NMR, and MS. BNQAS, C12QAS, C14QAS, and C16QAS were confirmed by X-ray single-crystal diffraction. Their antibacterial properties indicated good antibacterial abilities against E. coli, S. aureus, B. subtilis, especially C12QAS with the best antibacterial ability (100% to E. coli, 95.65% to S. aureus, and 91.41% to B. subtilis). In addition, C12QAS also displayed the best antifungal activities than BNQAS and C18QAS against Cytospora mandshurica, Botryosphaeria ribis, Physalospora piricola, and Glomerella cingulata with the ratio of full marks. The strategy provides a facile way to design and develop new types of antibacterial drugs for application in preventing the fruit rot, especially apple. © 2014 John Wiley & Sons A/S.

  8. Tagetes erecta, A Potential Medicinal Plant for Discovering a New Antibacterial Agent

    Directory of Open Access Journals (Sweden)

    Motamedi

    2015-08-01

    Full Text Available Background Tagetes genus contains 56 species and is native in North and South America, but some have become widespread around the world. Objectives This study was designed to examine the antibacterial potential of methanolic and ethanolic extracts of Tagetes erecta. Materials and Methods Hydroalcoholic extracts from aerial parts of this plant were prepared using aqueous solution of ethanol and methanol (8:2 v/v. The inhibitory effect of 1.5, 3, 6, 12 and 18 mg of effective dose per disc of these extracts was discovered against clinical bacterial isolates including three Gram-positive bacteria: Bacillus cereus, Staphylococcus aureus and S. epidermidis and five Gram-negative bacteria: Salmonella Typhi, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Proteus mirabilis. Minimum inhibitory concentration (MIC, minimum bactericidal concentration (MBC and time kill kinetic assay of these extracts were also investigated. Scanning electron microscopy (SEM analysis was performed to find possible structural changes following exposure to the extract. Results Both extracts of T. erecta were active against B. cereus, S. aureus, S. epidermidis and S. Typhi. Hydroalcoholic extracts of T. erecta showed significant antibacterial effects against some clinically important pathogenic bacteria. These extract also caused deformation and lysis of bacterial cells, as shown by SEM. Conclusions These extracts can be used as antibacterial agents in treating infectious diseases. Further studies are needed for considering this plant as an antibacterial plant and benefit from its clinical applications for routine use.

  9. Nasal Bacterial Colonization in Pediatric Epistaxis: The Role of Topical Antibacterial Treatment

    Directory of Open Access Journals (Sweden)

    Mukaddder Korkmaz

    2016-04-01

    Full Text Available Background: Epistaxis is a common problem in childhood. It has been shown that children with recurrent epistaxis are more likely to have nasal colonization with Staphylococcus aureus. It has been suggested that low-grade inflammation, crusting and increased vascularity due to bacterial colonization contributes to the development of epistaxis in children. Aims: This study aimed to investigate the nasal colonization and treatment outcome in pediatric epistaxis patients. Study Design: Retrospective cross-sectional study. Methods: Charts of the pediatric patients referred to our university hospital otolaryngology outpatient clinics for the evaluation of epistaxis were reviewed. The patients whose nasal cultures had been taken at the first clinical visit comprised the study group. Results: Staphylococcus aureus was the most common bacteria grown. The presence of crusting and hypervascularity was not dependent on the type of bacterial growth and there was no relation between hypervascularity and crusting of the nasal mucosa. Thirty-six patients were evaluated for the outcome analysis. Resolution of bleeding was not dependent on nasal colonization; in patients with colonization, there was no difference between topical antibacterial and non-antibacterial treatments. Conclusion: Despite the high colonization rates, topical antibacterial treatment was not found superior to non-antibacterial treatment. Our study does not support the belief that bacterial colonization results in hypervascularity of the septal mucosa causing epistaxis since no relation was found between nasal colonization, hypervascularity and crusting. The role of bacterial colonization in pediatric epistaxis need to be further investigated and treatment protocols must be determined accordingly.

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

    Directory of Open Access Journals (Sweden)

    D. J. BARNA

    2008-10-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  12. Antibacterial Barbituric Acid Analogues Inspired from Natural 3-Acyltetramic Acids; Synthesis, Tautomerism and Structure and Physicochemical Property-Antibacterial Activity Relationships

    Directory of Open Access Journals (Sweden)

    Yong-Chul Jeong

    2015-02-01

    Full Text Available The synthesis, tautomerism and antibacterial activity of novel barbiturates is reported. In particular, 3-acyl and 3-carboxamidobarbiturates exhibited antibacterial activity, against susceptible and some resistant Gram-positive strains of particular interest is that these systems possess amenable molecular weight, rotatable bonds and number of proton-donors/acceptors for drug design as well as less lipophilic character, with physicochemical properties and ionic states that are similar to current antibiotic agents for oral and injectable use. Unfortunately, the reduction of plasma protein affinity by the barbituric core is not sufficient to achieve activity in vivo. Further optimization to reduce plasma protein affinity and/or elevate antibiotic potency is therefore required, but we believe that these systems offer unusual opportunities for antibiotic drug discovery.

  13. [Cloning, prokaryotic expression and antibacterial assay of Tenecin gene encoding an antibacterial peptide from Tenebrio molitor].

    Science.gov (United States)

    Liu, Ying; Jiang, Yu-xin; Li, Chao-pin

    2011-12-01

    To clone tenecin gene, an antibacterial peptide gene, from Tenebrio molitor for its prokaryotic expression and explore the molecular mechanism for regulating the expression of antibacterial peptide in Tenebrio molitor larvae. The antibacterial peptide was induced from the larvae of Tenebrio molitor by intraperitoneal injection of Escherichia coli DH-5α (1×10(8)/ml). RT-PCR was performed 72 h after the injection to clone Tenecin gene followed by sequencing and bioinformatic analysis. The recombinant expression vector pET-28a(+)-Tenecin was constructed and transformed into E. coli BL21(DE3) cells and the expression of tenecin protein was observed after IPTG induction. Tenecin expression was detected in transformed E.coli using SDS-PAGE after 1 mmol/L IPTG induction. Tenecin gene, which was about 255 bp in length, encoded Tenecin protein with a relative molecular mass of 9 kD. Incubation of E.coli with 80, 60, 40, and 20 µg/ml tenecin for 18 h resulted in a diameter of the inhibition zone of 25.1∓0.03, 20.7∓0.06, 17.2∓0.11 and 9.3∓0.04 mm, respectively. Tenecin protein possesses strong antibacterial activity against E. coli DH-5α, which warrants further study of this protein for its potential as an antibacterial agent in clinical application.

  14. ANTIBACTERIAL ACTIVITY OF DRACONTOMELON DAO EXTRACTS ON METHICILLIN-RESISTANT S. AUREUS (MRSA) AND E. COLI MULTIPLE DRUG RESISTANCE (MDR).

    Science.gov (United States)

    Yuniati, Yuniati; Hasanah, Nurul; Ismail, Sjarif; Anitasari, Silvia; Paramita, Swandari

    2018-01-01

    Staphylococcus aureus , methicillin-resistant and Escherichia coli , multidrug-resistant included in the list of antibiotic-resistant priority pathogens from WHO. As multidrug-resistant bacteria problem is increasing, it is necessary to probe new sources for identifying antimicrobial compounds. Medicinal plants represent a rich source of antimicrobial agents. One of the potential plants for further examined as antibacterial is Dracontomelon dao (Blanco) Merr. & Rolfe. The present study designed to find the antibacterial activity of D. dao stem bark extracts on Methicillin-resistant S. aureus (MRSA) and E. coli Multiple Drug Resistance (MDR), followed by determined secondary metabolites with antibacterial activity and determined the value of MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration). D. dao stem bark extracted using 60% ethanol. Disc diffusion test methods used to find the antibacterial activity, following by microdilution methods to find the value of MIC and MBC. Secondary metabolites with antibacterial activity determined by bioautography using TLC (thin layer chromatography) methods. D. dao stem bark extracts are sensitive to MSSA, MRSA and E.coli MDR bacteria. The inhibition zone is 16.0 mm in MSSA, 11.7 mm in MRSA and 10.7 mm in E. coli MDR. The entire MBC/MIC ratios for MSSA, MRSA and E.coli MDR is lower than 4. The ratio showed bactericidal effects of D. dao stem bark extracts. In TLC results, colorless bands found to be secondary metabolites with antibacterial activity. D. dao stem bark extracts are potential to develop as antibacterial agent especially against MRSA and E. coli MDR strain.

  15. Antibacterial and Antifungal Activities of Spices

    Science.gov (United States)

    Liu, Qing; Meng, Xiao; Li, Ya; Zhao, Cai-Ning; Tang, Guo-Yi; Li, Hua-Bin

    2017-01-01

    Infectious diseases caused by pathogens and food poisoning caused by spoilage microorganisms are threatening human health all over the world. The efficacies of some antimicrobial agents, which are currently used to extend shelf-life and increase the safety of food products in food industry and to inhibit disease-causing microorganisms in medicine, have been weakened by microbial resistance. Therefore, new antimicrobial agents that could overcome this resistance need to be discovered. Many spices—such as clove, oregano, thyme, cinnamon, and cumin—possessed significant antibacterial and antifungal activities against food spoilage bacteria like Bacillus subtilis and Pseudomonas fluorescens, pathogens like Staphylococcus aureus and Vibrio parahaemolyticus, harmful fungi like Aspergillus flavus, even antibiotic resistant microorganisms such as methicillin resistant Staphylococcus aureus. Therefore, spices have a great potential to be developed as new and safe antimicrobial agents. This review summarizes scientific studies on the antibacterial and antifungal activities of several spices and their derivatives. PMID:28621716

  16. Fast Screening of Antibacterial Compounds from Fusaria

    Directory of Open Access Journals (Sweden)

    Teis Esben Sondergaard

    2016-11-01

    Full Text Available Bio-guided screening is an important method to identify bioactive compounds from fungi. In this study we applied a fast digital time-lapse microscopic method for assessment of the antibacterial properties of secondary metabolites from the fungal genus Fusarium. Here antibacterial effects could be detected for antibiotic Y, aurofusarin, beauvericin, enniatins and fusaric acid after six hours of cultivation. The system was then used in a bio-guided screen of extracts from 14 different Fusarium species, which had been fractionated by HPLC. In this screen, fractions containing the red pigments aurofusarin and bikaverin showed effects against strains of Lactobacillus and Bifidobacterium. The IC50 for aurofusarin against Lactobacillus acidophilus was 8 µM, and against Bifidobacterium breve it was 64 µM. Aurofusarin only showed an effect on probiotic bacteria, leading to the speculation that only health-promoting bacteria with a positive effect in the gut system are affected.

  17. Antibacterial phenolics from the mangrove Lumnitzera racemosa

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, L.; Wahidullah, S.; PrabhaDevi

    -(4- hydroxyphenyl)-propyl-3′-(3,4-dihydroxyphenyl)- propionate1. This communication relates to the identification of antibacterial principle in L. racemosa which is associated with polyphenolic constituents. The efficacy of this mangrove has been studied... be necessary for a full evaluation of their practical usefulness in the field of modern medicine. Acknowledgements The authors thank Dr. S. R. Shetye, Director, NIO for his keen interest in the work. Financial support by Ministry of Earth Sciences under...

  18. Antibacterial nanofiber materials activated by light

    Czech Academy of Sciences Publication Activity Database

    Jesenská, S.; Plištil, L.; Kubát, Pavel; Lang, Kamil; Brožová, Libuše; Popelka, Štěpán; Szatmáry, Lórant; Mosinger, Jiří

    99A, č. 4 (2011), s. 676-683 ISSN 1549-3296 R&D Projects: GA ČR GAP208/10/1678 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40320502; CEZ:AV0Z40500505 Keywords : antibacterial nanofiber materials * photoactive * singlet oxygen Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.625, year: 2011

  19. Antibacterial Compounds from Red Seaweeds (Rhodophyta)

    OpenAIRE

    Noer Kasanah; Triyanto Triyanto; Drajad Sarwo Seto; Windi Amelia; Alim Isnansetyo

    2015-01-01

    Seaweeds produce great variety of metabolites benefit for human. Red seaweeds (Rhodophyta) are well known as producer of phycocolloids such agar, agarose, carragenan and great variety of secondary metabolites. This review discusses the red algal secondary metabolites with antibacterial activity. The chemical constituents of red algae are steroid, terpenoid, acetogenin and dominated by halogenated compounds mainly brominated compounds. Novel compounds with intriguing skeleton are also reported...

  20. A new antibacterial benzophenone glycoside from Psidium guajava (Linn.) leaves.

    Science.gov (United States)

    Ukwueze, Stanley E; Osadebe, Patience O; Okoye, Festus B C

    2015-01-01

    Bioactivity-guided fractionation of methanol extract from the leaves of Psidium guajava L. (Myrtaceae) yielded a new benzophenone glycoside, Guajaphenone A (2) together with two known compounds, Garcimangosone D (1) and Guaijaverin (3). Their structures were elucidated by analysis of spectroscopic data including 1D and 2D NMR and electrospray ionisation mass spectrometry (ESI-MS). The isolated compounds were screened against standard strains of Gram-positive and Gram-negative bacteria using broth dilution assay method, and the MIC values determined and compared with reference antibiotic ceftriaxone. They were found to have significant antibacterial activities against Escherichia coli and Staphylococcus aureus with all of them showing better activities against S. aureus, but displaying weaker activities, in comparison to ceftriaxone. However, despite reduced effect of these compounds against the organisms, this work opens the perspective to use these molecules as 'leads' for the design of novel and selective drug candidates for some tropical infectious diseases.

  1. What Makes a Natural Clay Antibacterial?

    Science.gov (United States)

    Williams, Lynda B.; Metge, David W.; Eberl, Dennis D.; Harvey, Ronald W.; Turner, Amanda G.; Prapaipong, Panjai; Poret-Peterson, Amisha T.

    2011-01-01

    Natural clays have been used in ancient and modern medicine, but the mechanism(s) that make certain clays lethal against bacterial pathogens has not been identified. We have compared the depositional environments, mineralogies, and chemistries of clays that exhibit antibacterial effects on a broad spectrum of human pathogens including antibiotic resistant strains. Natural antibacterial clays contain nanoscale (clay minerals in the bactericidal process is to buffer the aqueous pH and oxidation state to conditions that promote Fe2+ solubility. Chemical analyses of E. coli killed by aqueous leachates of an antibacterial clay show that intracellular concentrations of Fe and P are elevated relative to controls. Phosphorus uptake by the cells supports a regulatory role of polyphosphate or phospholipids in controlling Fe2+. Fenton reaction products can degrade critical cell components, but we deduce that extracellular processes do not cause cell death. Rather, Fe2+ overwhelms outer membrane regulatory proteins and is oxidized when it enters the cell, precipitating Fe3+ and producing lethal hydroxyl radicals. PMID:21413758

  2. Antibacterial Functionalization of PVD Coatings on Ceramics

    Directory of Open Access Journals (Sweden)

    Javier Osés

    2018-05-01

    Full Text Available The application of surface treatments that incorporate silver or copper as antibacterial elements has become a common practice for a wide variety of medical devices and materials because of their effective activity against nosocomial infections. Ceramic tiles are choice materials for cladding the floors and walls of operation rooms and other hospital spaces. This study is focused on the deposition of biocide physical vapor deposition (PVD coatings on glazed ceramic tiles. The objective was to provide antibacterial activity to the surfaces without worsening their mechanical properties. Silver and copper-doped chromium nitride (CrN and titanium nitride (TiN coatings were deposited on samples of tiles. A complete characterization was carried out in order to determine the composition and structure of the coatings, as well as their topographical and mechanical properties. The distribution of Ag and Cu within the coating was analyzed using glow discharge optical emission spectrometry (GD-OES and field emission scanning electron microscope (FE-SEM. Roughness, microhardness, and scratch resistance were measured for all of the combinations of coatings and dopants, as well as their wettability. Finally, tests of antibacterial efficacy against Staphylococcus aureus and Escherichia coli were carried out, showing that all of the doped coatings had pronounced biocide activity.

  3. Antibacterial properties of laser spinning glass nanofibers.

    Science.gov (United States)

    Echezarreta-López, M M; De Miguel, T; Quintero, F; Pou, J; Landin, M

    2014-12-30

    A laser-spinning technique has been used to produce amorphous, dense and flexible glass nanofibers of two different compositions with potential utility as reinforcement materials in composites, fillers in bone defects or scaffolds (3D structures) for tissue engineering. Morphological and microstructural analyses have been carried out using SEM-EDX, ATR-FTIR and TEM. Bioactivity studies allow the nanofibers with high proportion in SiO2 (S18/12) to be classified as a bioinert glass and the nanofibers with high proportion of calcium (ICIE16) as a bioactive glass. The cell viability tests (MTT) show high biocompatibility of the laser spinning glass nanofibers. Results from the antibacterial activity study carried out using dynamic conditions revealed that the bioactive glass nanofibers show a dose-dependent bactericidal effect on Sthaphylococcus aureus (S. aureus) while the bioinert glass nanofibers show a bacteriostatic effect also dose-dependent. The antibacterial activity has been related to the release of alkaline ions, the increase of pH of the medium and also the formation of needle-like aggregates of calcium phosphate at the surface of the bioactive glass nanofibers which act as a physical mechanism against bacteria. The antibacterial properties give an additional value to the laser-spinning glass nanofibers for different biomedical applications, such as treating or preventing surgery-associated infections. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Towards Identify Selective Antibacterial Peptides Based on Abstracts Meaning

    Directory of Open Access Journals (Sweden)

    Liliana I. Barbosa-Santillán

    2016-01-01

    Full Text Available We present an Identify Selective Antibacterial Peptides (ISAP approach based on abstracts meaning. Laboratories and researchers have significantly increased the report of their discoveries related to antibacterial peptides in primary publications. It is important to find antibacterial peptides that have been reported in primary publications because they can produce antibiotics of different generations that attack and destroy the bacteria. Unfortunately, researchers used heterogeneous forms of natural language to describe their discoveries (sometimes without the sequence of the peptides. Thus, we propose that learning the words meaning instead of the antibacterial peptides sequence is possible to identify and predict antibacterial peptides reported in the PubMed engine. The ISAP approach consists of two stages: training and discovering. ISAP founds that the 35% of the abstracts sample had antibacterial peptides and we tested in the updated Antimicrobial Peptide Database 2 (APD2. ISAP predicted that 45% of the abstracts had antibacterial peptides. That is, ISAP found that 810 antibacterial peptides were not classified like that, so they are not reported in APD2. As a result, this new search tool would complement the APD2 with a set of peptides that are candidates to be antibacterial. Finally, 20% of the abstracts were not semantic related to APD2.

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

    Science.gov (United States)

    Senthilkumar, Pandurangan; Karthik, Thangavelu

    2016-04-01

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

  6. 3D-printed bioceramic scaffolds with antibacterial and osteogenic activity.

    Science.gov (United States)

    Zhang, Yongliang; Zhai, Dong; Xu, Mengchi; Yao, Qingqiang; Zhu, Huiying; Chang, Jiang; Wu, Chengtie

    2017-06-20

    Bacterial infection poses a significant risk with the wide application of bone graft materials. Designing bone grafts with good antibacterial performance and excellent bone-forming activity is of particular significance for bone tissue engineering. In our study, a 3D printing method was used to prepare β-tricalcium phosphate (β-TCP) bioceramic scaffolds. Silver (Ag) nanoparticles were uniformly dispersed on graphene oxide (GO) to form a homogeneous nanocomposite (named Ag@GO) with different Ag-to-graphene oxide mass ratios, with this being synthesized via the liquid chemical reduction approach. Ag@GO nanocomposites were successfully modified on the β-TCP scaffolds by a simple soaking method to achieve bifunctional biomaterials with antibacterial and osteogenic activity. The prepared scaffolds possessed a connected network with triangle pore morphology and the surfaces of the β-TCP scaffolds were uniformly modified by the Ag@GO nanocomposite layers. The Ag content in the scaffolds was controlled by changing the coating times and concentration of the Ag@GO nanocomposites. The antibacterial activity of the scaffolds was assessed with Gram-negative bacteria (Escherichia coli, E. coli). The results demonstrated that the scaffolds with Ag@GO nanocomposites presented excellent antibacterial activity. In addition, the scaffolds coated with Ag@GO nanocomposites conspicuously accelerated the osteogenic differentiation of rabbit bone marrow stromal cells by improving their alkaline phosphatase activity and bone-related gene expression (osteopontin, runt-related transcription factor 2, osteocalcin and bone sialoprotein). This study demonstrates that bifunctional scaffolds with a combination of antibacterial and osteogenic activity can be achieved for the reconstruction of large-bone defects while preventing or treating infections.

  7. Bacillus spp. produce antibacterial activities against lactic acid bacteria that contaminate fuel ethanol plants.

    Science.gov (United States)

    Manitchotpisit, Pennapa; Bischoff, Kenneth M; Price, Neil P J; Leathers, Timothy D

    2013-05-01

    Lactic acid bacteria (LAB) frequently contaminate commercial fuel ethanol fermentations, reducing yields and decreasing profitability of biofuel production. Microorganisms from environmental sources in different geographic regions of Thailand were tested for antibacterial activity against LAB. Four bacterial strains, designated as ALT3A, ALT3B, ALT17, and MR1, produced inhibitory effects on growth of LAB. Sequencing of rRNA identified these strains as species of Bacillus subtilis (ALT3A and ALT3B) and B. cereus (ALT17 and MR1). Cell mass from colonies and agar samples from inhibition zones were analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The spectra of ALT3A and ALT3B showed a strong signal at m/z 1,060, similar in mass to the surfactin family of antimicrobial lipopeptides. ALT3A and ALT3B were analyzed by zymogram analysis using SDS-PAGE gels placed on agar plates inoculated with LAB. Cell lysates possessed an inhibitory protein of less than 10 kDa, consistent with the production of an antibacterial lipopeptide. Mass spectra of ALT17 and MR1 had notable signals at m/z 908 and 930 in the whole cell extracts and at m/z 687 in agar, but these masses do not correlate with those of previously reported antibacterial lipopeptides, and no antibacterial activity was detected by zymogram. The antibacterial activities produced by these strains may have application in the fuel ethanol industry as an alternative to antibiotics for prevention and control of bacterial contamination.

  8. Pharmacokinetics, efficacy prediction indexes and residue depletion of antibacterial drugs.

    Directory of Open Access Journals (Sweden)

    Arturo Anadón

    2016-06-01

    Full Text Available Pharmacokinetics behaviour of the antibacterial in food producing animals, provides information on the rates of absorption and elimination, half-life in plasma and tissue, elimination pathways and metabolism. The dose and the dosing interval of the antimicrobial can be justified by considering the pharmacokinetic/pharmacodynamic (PK/PD relationship, if established, as well as the severity of the disease, whereas the number of administrations should be in line with the nature of the disease. The target population for therapy should be well defined and possible to identify under field conditions. Based on in vitro susceptibility data, and target animal PK data, an analysis for the PK/PD relationship may be used to support dose regimen selection and interpretation criteria for a clinical breakpoint. Therefore, for all antibacterials with systemic activity, the MIC data collected should be compared with the concentration of the compound at the relevant biophase following administration at the assumed therapeutic dose as recorded in the pharmacokinetic studies. Currently, the most frequently used parameters to express the PK/PD relationship are Cmax/MIC (maximum serum concentration/MIC, %T > MIC (fraction of time in which concentration exceeds MIC and AUC/MIC (area under the inhibitory concentration– time curve/MIC. Furthermore, the pharmacokinetic parameters provide the first indication of the potential for persistent residues and the tissues in which they may occur. The information on residue depletion in food-producing animals, provides the data on which MRL recommendations will be based. A critical factor in the antibacterial medication of all food-producing animals is the mandatory withdrawal period, defined as the time during which drug must not be administered prior to the slaughter of the animal for consumption. The withdrawal period is an integral part of the regulatory authorities’ approval process and is designed to ensure that no

  9. Microwave synthesis and antibacterial studies of bioceramics doped with antibacterial metal

    Science.gov (United States)

    Iqbal, Nida; Kadir, M. R. Abdul

    2017-12-01

    The aim of this work was to evaluate the effect of zinc metal ion on the antibacterial properties of bioceramics i.e. hydroxyapatite for the protection of bacterial infections. In this paper, rapid icrowave synthesis of hydroxyapatite with different weightages of antibacterial ions zinc (2 and 4 wt%) at 850 watts via microwave irradiation method at 10 mins was reported. The synthesized bioceramics were chemically characterized using energy dispersive X-ray (EDAX) and Fourier transform infrared spectroscopy (FTIR) studies. FT-IR analysis revealed the presence of Zn into HA lattices due to the increasing in the vibrational modes corresponds to phosphates and hydroxyl groups and EDAX analysis confirmed the presence of oxygen (O), calcium (Ca), phosphor (P), and zinc (Zn) in the ZnHA samples. Antibacterial studies have demonstrated that each of the Zn-bearing bioceramics samples exhibits marked antibacterial effects against Bacillus subtilis and Pseudomonas aeruginosa. Based on the results, it can be concluded that the synthesized Zn HA bioceramics have potential to prevent the bacterial infections and can be used as bone tissue regeneration.

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

    African Journals Online (AJOL)

    USER

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

  11. Anti-bacterial activities and phytochemical screening of extracts of ...

    African Journals Online (AJOL)

    Anti-bacterial activity tests were carried out using disc diffusion assay and tube dilution technique, and phytochemical screening was carried out through Thin Layer Chromatography. The crude extracts showed antibacterial effects on M. vaccae, P. aeruginosa and B. subtilis. M. vaccae was most sensitive, particularly to the ...

  12. CRISPR-Based Antibacterials: Transforming Bacterial Defense into Offense.

    Science.gov (United States)

    Greene, Adrienne C

    2018-02-01

    The development of antimicrobial-resistant (AMR) bacteria poses a serious worldwide health concern. CRISPR-based antibacterials are a novel and adaptable method for building an arsenal of antibacterials potentially capable of targeting any pathogenic bacteria. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Evaluation of in vitro antibacterial property of seaweeds of southeast ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... high antibacterial activity than other members of the algae tested in the present ... study confirmed the potential use of seaweed extracts as a source of antibacterial compounds. ... marine algae belonging to families such as Chlorphyceae .... seasons, method, organic solvents used for extraction of bioactive ...

  14. Antibacterial Activity and Mode of Action of Mentha arvensis Ethanol ...

    African Journals Online (AJOL)

    Antibacterial Activity and Mode of Action of Mentha arvensis Ethanol Extract against ... the antibacterial effect of ethanol extract of Mentha arvensis against multi-drug ... Reactive oxygen species (ROS) generation and protein leakage from the ... A. baumannii and acts by inducing lethal cellular damage to the bacterium.

  15. Antibacterial compounds from marine Vibrionaceae isolated on a global expedition

    DEFF Research Database (Denmark)

    Wietz, Matthias; Månsson, Maria; Gotfredsen, Charlotte Held

    2010-01-01

    known antibiotics as being responsible for the antibacterial activity; andrimid (from V. coralliilyticus) and holomycin (from P. halotolerans). Despite the isolation of already known antibiotics, our findings show that marine Vibrionaceae are a resource of antibacterial compounds and may have potential...

  16. The phytochemical, antibacterial and antioxidant activity of five ...

    African Journals Online (AJOL)

    The phytochemical, antibacterial and antioxidant activity of five medicinal plants against the wound infecting bacteria. ... Phytochemical analyses of the extracts were performed using thin layer chromatography (TLC). ... Antibacterial activity of the plants was evaluated using micro-dilution and bioautography methods.

  17. Antibacterial activity of the crude extract of Chinese green tea ...

    African Journals Online (AJOL)

    Antibacterial activity of the crude extract of Chinese green tea (Camellia sinensis) on Listeria monocytogenes. TI Mbata, LU Debiao, A Saikia. Abstract. The antibacterial activity of the methanol and aqueous extract of Camellia sinensis on Listeria monocytogenes were investigated using agar-gel diffusion, paper disk ...

  18. Antibacterial action of an aqueous grape seed polyphenolic extract ...

    African Journals Online (AJOL)

    The potential of a polyphenolic grape seed extract for use as a natural antibacterial agent was evaluated. Pure catechin (CS) and a previously LC-MS characterized grape seed phenolic extract (PE) were evaluated as antibacterial agents against Escherichia coli and Brevibacterium linens on solid and in liquid culture media ...

  19. Economic Evaluation pf Antibacterial Usage in Ear, Nose and Throat ...

    African Journals Online (AJOL)

    Purpose: To carry out economic evaluation of antibacterial usage for Ear, Nose and Throat infections in a tertiary health care facility in Nigeria. Methods: Antibacterial utilisation evaluation was carried out retrospectively over one year period by reviewing 122 case notes containing 182 prescriptions of patient with Ear Nose ...

  20. Evaluation of phytochemical and antibacterial potential of Helicteres ...

    African Journals Online (AJOL)

    Antibacterial activities of aqueous, acetone, ethanol and methanol extracts of fruits of Helicteres isora (Mororphali) were studied. The fruit aqueous extracts of H. isora showed prominent antibacterial activities against E.coli, Staphylococcus epidermidis, Salmonella typhimurium and Proteus vulgaris; moderate activity against ...

  1. Antibacterial activities of PHU - AgNO3 nanocomposite

    International Nuclear Information System (INIS)

    Panzaru, Carmen; Danciu, M; Mihailovici, Maria-Sultana; Ciobanu, C

    2009-01-01

    Objective was to characterize the antibacterial action for six combination of PHU-AgNO 3 synthesized in 'Petru Poni' Institute of Macromolecular Chemistry, Iasi, Romania. The advantages of Ag nanoparticles are durability, heat resistant, low toxicity. Silver is known for its antibacterial qualities for a long time and has been used in medicine in topical treatment.

  2. Investigation Into The Antibacterial And Antidiarrhoeal Properties Of ...

    African Journals Online (AJOL)

    Objective: The water extract (WE) and ethanol extract (EE) of Psidium guava Leaf were carried out for antibacterial and antidiarrhoeal effects using patients stool and animal models. The antibacterial sensitivity tests were based on their zone of inhibition for six species of bacteria which include: Aeromonas hydrophila, ...

  3. Fumaric acid, an antibacterial component of Aloe vera L. | He ...

    African Journals Online (AJOL)

    The acetoacetate fraction partitioned from Aloe vera L. showed an effective antibacterial activity against four clinically frequent pathogenic bacteria. Through a series of chromatographic methods and activity assays, one compound was obtained and it has potent antibacterial activity. Based on the data of mass spectrometry, ...

  4. Antibacterial activity of Mangifera indica L. seeds against some ...

    African Journals Online (AJOL)

    Antibacterial activity of methanol extract of Mangifera indica L. seeds was done against 41 clinically isolated and 20 standard bacterial strains. Clinical bacterial strains were isolated from different specimens like blood, urine, catheter, stool and pus. Antibacterial activity was done by agar disc diffusion method at two different ...

  5. Antibacterial activity and probiotic properties of some lactic acid ...

    African Journals Online (AJOL)

    Several lactic acid bacteria strains were screened for the production of antibacterial substances active against some pathogenic bacteria. The inhibitory mechanism was investigated and was shown to be dependant of bacteriocin production. The objective was to isolate LAB with antibacterial activity from raib and to select ...

  6. Evaluation of Antibacterial Activity of Prosopis Juliflora (Sw.) Dc ...

    African Journals Online (AJOL)

    Background: The ethnobotanical importance of Prosopis juliflora is well-known in the folkloric system of medicine for the treatment of various ailments. Although, the study related to the antibacterial potential of this plant, from Central India is scanty. Material and methods: The in vitro antibacterial activity of Prosopis juliflora ...

  7. Antifungal and antibacterial activities of the ethanolic and aqueous ...

    African Journals Online (AJOL)

    SERVER

    2007-07-18

    Jul 18, 2007 ... psoriasis and eczema, through to the more serious disease like leprosy, syphilis and skin cancer (Burkill,. 1985). Previous studies of the fruits of K. africana showed some antibacterial activity (Grace et al., 2002). However there is no report on the antibacterial and antifungal properties of the stem bark of this ...

  8. Antibacterial activity of some selected plants traditionally used as ...

    African Journals Online (AJOL)

    Antibacterial activity of some selected plants traditionally used as medicine in Manipur. ... Hence these plants can be used to discover bioactive natural products that may serve as leads in the development of the new pharmaceuticals. Keywords: Antibacterial, human pathogens, methanolic extract, traditional medicine

  9. Antibacterial properties and toxicity from metallic nanomaterials

    Directory of Open Access Journals (Sweden)

    Vimbela GV

    2017-05-01

    Full Text Available Gina V Vimbela,1,* Sang M Ngo,2,* Carolyn Fraze,3 Lei Yang,4,5 David A Stout5–7 1Department of Chemical Engineering, 2Department of Electrical Engineering, California State University, Long Beach, CA, 3Brigham Young University Idaho, Rexburg, ID, USA; 4Department of Orthopaedics, Orthopaedic Institute, The First Affiliated Hospital, 5International Research Center for Translational Orthopaedics (IRCTO, Soochow University, Suzhou, Jiangsu, People’s Republic of China; 6Department of Mechanical and Aerospace Engineering, 7Department of Biomedical Engineering, California State University, Long Beach, CA, USA *These authors contributed equally to this work Abstract: The era of antibiotic resistance is a cause of increasing concern as bacteria continue to develop adaptive countermeasures against current antibiotics at an alarming rate. In recent years, studies have reported nanoparticles as a promising alternative to antibacterial reagents because of their exhibited antibacterial activity in several biomedical applications, including drug and gene delivery, tissue engineering, and imaging. Moreover, nanomaterial research has led to reports of a possible relationship between the morphological characteristics of a nanomaterial and the magnitude of its delivered toxicity. However, conventional synthesis of nanoparticles requires harsh chemicals and costly energy consumption. Additionally, the exact relationship between toxicity and morphology of nanomaterials has not been well established. Here, we review the recent advancements in synthesis techniques for silver, gold, copper, titanium, zinc oxide, and magnesium oxide nanomaterials and composites, with a focus on the toxicity exhibited by nanomaterials of multidimensions. This article highlights the benefits of selecting each material or metal-based composite for certain applications while also addressing possible setbacks and the toxic effects of the nanomaterials on the environment. Keywords

  10. Antibacterial characteristics of thermal plasma spray system.

    Science.gov (United States)

    Goudarzi, M; Saviz, Sh; Ghoranneviss, M; Salar Elahi, A

    2018-03-15

    The objective of this study is to investigate antibacterial characteristics of a thermal plasma spray system. For this purpose, copper powder was coated on a handmade atmospheric plasma spraying system made by the stainless steel 316 substrate, which is preheated at different temperatures before spraying. A number of deposition characteristics such as antibacterial characteristics, adhesion strength and hardness of coating, was investigated. All of the spray parameters are fixed except the substrate temperature. The chemical composition was analyzed by X-ray diffraction (XRD). A scanning electron microscopy (SEM) and back scattering electron microscopy (BSE) were used to show the coating microstructure, its thickness and also the powder micrograph. The energy dispersive X-ray spectroscopy (EDX) was used to analyze the coating particles. Hardness of the deposition was examined by Vickers tester (HV0.1). Its adhesion strength was declared by cross cut tester (TQC). In addition, the percentage of bactericidal coating was evidenced with Staphylococcus aurous and Escherichia coli bacteria. Study results show that as the substrates temperature increases, the number of splats in the shape of pancake increases, the greatness and percentage of the deposition porosity both decrease. The increment of the substrate temperature leads to more oxidation and makes thicker dendrites on the splat. The enhancement of the substrate temperature also enlarges thickness and efficiency of coating. The interesting results are that antibacterial properties of coatings against the Escherichia coli are more than Staphylococcus aurous bacteria. However the bactericidal percentage of the coatings against Staphylococcus aurous and Escherichia coli bacteria roughly does not change with increasing the substrate temperature. Furthermore, by increment of the substrate temperature, coatings with both high adhesion and hardness are obtained. Accordingly, the temperature of substrate can be an

  11. Trace elements and antibacterial activity in amniotic fluid.

    Science.gov (United States)

    Honkonen, E; Näntö, V; Hyörä, H; Vuorinen, K; Erkkola, R

    1986-01-01

    Antibacterial activity and trace element concentrations in amniotic fluid (AF) were determined in a population of 39 pregnant women in the second half of gestation. Antibacterial activity in each AF was measured by a spectrophotometric micromethod after 18 h incubation at 37 degrees C using Escherichia coli K 12 as a reference bacterium. Concentrations of zinc, iron, copper, calcium, potassium and bromine were measured by particle-induced X-ray emission method and the zinc concentration was also measured by atomic absorption spectrophotometry. Phosphate concentration was determined by direct albumin adding method. In AFs with good antibacterial activity significantly lower concentrations of potassium and bromine were found when compared to AFs with lower antibacterial activity. Concentrations of zinc, iron, copper, calcium or phosphate did not correlate with antibacterial activity in AF.

  12. In Vitro Antibacterial Activity of Essential Oils against Streptococcus pyogenes

    Directory of Open Access Journals (Sweden)

    Julien Sfeir

    2013-01-01

    Full Text Available Streptococcus pyogenes plays an important role in the pathogenesis of tonsillitis. The present study was conducted to evaluate the in vitro antibacterial activities of 18 essential oils chemotypes from aromatic medicinal plants against S. pyogenes. Antibacterial activity of essential oils was investigated using disc diffusion method. Minimum Inhibitory Concentration of essential oils showing an important antibacterial activity was measured using broth dilution method. Out of 18 essential oils tested, 14 showed antibacterial activity against S. pyogenes. Among them Cinnamomum verum, Cymbopogon citratus, Thymus vulgaris CT thymol, Origanum compactum, and Satureja montana essential oils exhibited significant antibacterial activity. The in vitro results reported here suggest that, for patients suffering from bacterial throat infections, if aromatherapy is used, these essential oils, considered as potential antimicrobial agents, should be preferred.

  13. Carbon nanotubes as anti-bacterial agents.

    Science.gov (United States)

    Mocan, Teodora; Matea, Cristian T; Pop, Teodora; Mosteanu, Ofelia; Buzoianu, Anca Dana; Suciu, Soimita; Puia, Cosmin; Zdrehus, Claudiu; Iancu, Cornel; Mocan, Lucian

    2017-10-01

    Multidrug-resistant bacterial infections that have evolved via natural selection have increased alarmingly at a global level. Thus, there is a strong need for the development of novel antibiotics for the treatment of these infections. Functionalized carbon nanotubes through their unique properties hold great promise in the fight against multidrug-resistant bacterial infections. This new family of nanovectors for therapeutic delivery proved to be innovative and efficient for the transport and cellular translocation of therapeutic molecules. The current review examines the latest progress in the antibacterial activity of carbon nanotubes and their composites.

  14. Tragacanth gum/nano silver hydrogel on cotton fabric: In-situ synthesis and antibacterial properties.

    Science.gov (United States)

    Montazer, M; Keshvari, A; Kahali, P

    2016-12-10

    This paper is mainly focused on introducing cotton fabric with hydrogel and antimicrobial properties using Tragacanth gum as a natural polymer with hydrogel properties, silver nitrate as silver precursor, citric acid as a cross-linking agent and sodium hypophosphite as catalyst. The water absorption behavior of the treated fabrics was investigated with moisture regain, water retention, drying time of wetted fabric at room condition and vertical wicking tests. Antibacterial properties of the samples were evaluated against Escherichia coli and Staphylococcous aureus. The SEM pictures confirmed formation of nano silver and hydrogel layer on the fabric surface and XRD performed the crystal and particle size of the nano silver. The chemical structure of the fabric samples was identified with FTIR spectra. The central composite design (CCD) was used for statistical modelling, evaluated effective parameters and created optimum conditions. The treated cotton fabrics showed good water absorption properties along with reasonable antibacterial effectiveness. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Design

    DEFF Research Database (Denmark)

    Volf, Mette

    This publication is unique in its demystification and operationalization of the complex and elusive nature of the design process. The publication portrays the designer’s daily work and the creative process, which the designer is a part of. Apart from displaying the designer’s work methods...... and design parameters, the publication shows examples from renowned Danish design firms. Through these examples the reader gets an insight into the designer’s reality....

  16. Antibacterial Nanoparticles in Endodontics: A Review.

    Science.gov (United States)

    Shrestha, Annie; Kishen, Anil

    2016-10-01

    A major challenge in root canal treatment is the inability of the current cleaning and shaping procedures to eliminate bacterial biofilms surviving within the anatomic complexities and uninstrumented portions of the root canal system. Nanoparticles with their enhanced and unique physicochemical properties, such as ultrasmall sizes, large surface area/mass ratio, and increased chemical reactivity, have led research toward new prospects of treating and preventing dental infections. This article presents a comprehensive review on the scientific knowledge that is available on the application of antibacterial nanoparticles in endodontics. The application of nanoparticles in the form of solutions for irrigation, medication, and as an additive within sealers/restorative materials has been evaluated to primarily improve the antibiofilm efficacy in root canal and restorative treatments. In addition, antibiotic or photosensitizer functionalized nanoparticles have been proposed recently to provide more potent antibacterial efficacy. The increasing interest in this field warrants sound research based on scientific and clinical collaborations to emphasize the near future potential of nanoparticles in clinical endodontics. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Quaternary Ammonium Polyethyleneimine: Antibacterial Activity Ira

    International Nuclear Information System (INIS)

    Farber, Y.; Domb, A.G.; Golenser, J.; Beyth, N.; Weiss, E.I.

    2010-01-01

    Quaternary ammonium polyethyleneimine- (QA-PEI-) based nanoparticles were synthesized using two synthetic methods, reductive amination and N-alkylation. According to the first method, QA-PEI nanoparticles were synthesized by cross-linking with glutaraldehyde followed by reductive amination with octanal and further N-methylation with methyl iodide. The second method is based on crosslinking with dialkyl halide followed by N-alkylation with octyl halide and further N-methylation with methyl iodide. QA-PEI nanoparticles completely inhibited bacterial growth (>106 bacteria), including both Gram-positive, that is, Staphylococcus aureus at 80 μ/mL, and Gram-negative, that is, Escherichia coli at 320 μ/mL. Activity analysis revealed that the degree of alkylation and N-methylation of the QA-PEI nanoparticles plays a significant role in antibacterial activity of the reagent. The most potent compound was octyl alkylated QA-PEI alkylated at 1 : 1 mole ratio (primary amine of PEI monomer units/alkylating agent). Also, cytotoxicity studies on MAT-LyLu and MBT cell lines were performed with QA-PEI nanoparticles. These findings confirm previous reports that poly cations bearing quaternary ammonium moieties inhibit bacterial growth in vitro and have a potential use as additives in medical devices which need antibacterial properties.

  18. Antibacterial activity of plasma from crocodile (Crocodylus siamensis against pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Kommanee Jintana

    2012-07-01

    , perturbing and damaging bacterial membranes. The effect of the crude plasma was not toxic by the yellow tetrazolium bromide (MTT assay using a macrophage-like cell, RAW 264.7. The pooled four fractions, designated as fractions D1-D4, were obtained by column chromatography, and only fraction D1 showed growth inhibition in the reference strains and the clinical, human pathogenic isolates. Conclusions The crude and purified plasma from the Siamese crocodile significantly showed antibacterial activity against pathogenic bacteria and reference strains by damage cell membrane of target bacterial cells. From the MTT assay, the Siamese crocodile plasma was not cytotoxic to the cells.

  19. Antibacterial and Antioxidant Activities of Novel Actinobacteria Strain Isolated from Gulf of Khambhat, Gujarat.

    Science.gov (United States)

    Dholakiya, Riddhi N; Kumar, Raghawendra; Mishra, Avinash; Mody, Kalpana H; Jha, Bhavanath

    2017-01-01

    Bacterial secondary metabolites possess a wide range of biologically active compounds including antibacterial and antioxidants. In this study, a Gram-positive novel marine Actinobacteria was isolated from sea sediment which showed 84% 16S rRNA gene sequence (KT588655) similarity with Streptomyces variabilis (EU841661) and designated as Streptomyces variabilis RD-5. The genus Streptomyces is considered as a promising source of bioactive secondary metabolites. The isolated novel bacterial strain was characterized by antibacterial characteristics and antioxidant activities. The BIOLOG based analysis suggested that S. variabilis RD-5 utilized a wide range of substrates compared to the reference strain. The result is further supported by statistical analysis such as AWCD (average well color development), heat-map and PCA (principal component analysis). The whole cell fatty acid profiling showed the dominance of iso/anteiso branched C15-C17 long chain fatty acids. The identified strain S. variabilis RD-5 exhibited a broad spectrum of antibacterial activities for the Gram-negative bacteria ( Escherichia coli NCIM 2065, Shigella boydii NCIM, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas sp. NCIM 2200 and Salmonella enteritidis NCIM), and Gram-positive bacteria ( Bacillus subtilis NCIM 2920 and Staphylococcus aureus MTCC 96). Extract of S. variabilis strain RD-5 showed 82.86 and 89% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and metal chelating activity, respectively, at 5.0 mg/mL. While H 2 O 2 scavenging activity was 74.5% at 0.05 mg/mL concentration. Furthermore, polyketide synthases (PKSs types I and II), an enzyme complex that produces polyketides, the encoding gene(s) detected in the strain RD-5 which may probably involve for the synthesis of antibacterial compound(s). In conclusion, a novel bacterial strain of Actinobacteria , isolated from the unexplored sea sediment of Alang, Gulf of Khambhat (Gujarat), India showed promising

  20. Antibacterial and Antioxidant Activities of Novel Actinobacteria Strain Isolated from Gulf of Khambhat, Gujarat

    Directory of Open Access Journals (Sweden)

    Riddhi N. Dholakiya

    2017-12-01

    Full Text Available Bacterial secondary metabolites possess a wide range of biologically active compounds including antibacterial and antioxidants. In this study, a Gram-positive novel marine Actinobacteria was isolated from sea sediment which showed 84% 16S rRNA gene sequence (KT588655 similarity with Streptomyces variabilis (EU841661 and designated as Streptomyces variabilis RD-5. The genus Streptomyces is considered as a promising source of bioactive secondary metabolites. The isolated novel bacterial strain was characterized by antibacterial characteristics and antioxidant activities. The BIOLOG based analysis suggested that S. variabilis RD-5 utilized a wide range of substrates compared to the reference strain. The result is further supported by statistical analysis such as AWCD (average well color development, heat-map and PCA (principal component analysis. The whole cell fatty acid profiling showed the dominance of iso/anteiso branched C15–C17 long chain fatty acids. The identified strain S. variabilis RD-5 exhibited a broad spectrum of antibacterial activities for the Gram-negative bacteria (Escherichia coli NCIM 2065, Shigella boydii NCIM, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas sp. NCIM 2200 and Salmonella enteritidis NCIM, and Gram-positive bacteria (Bacillus subtilis NCIM 2920 and Staphylococcus aureus MTCC 96. Extract of S. variabilis strain RD-5 showed 82.86 and 89% of 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical scavenging and metal chelating activity, respectively, at 5.0 mg/mL. While H2O2 scavenging activity was 74.5% at 0.05 mg/mL concentration. Furthermore, polyketide synthases (PKSs types I and II, an enzyme complex that produces polyketides, the encoding gene(s detected in the strain RD-5 which may probably involve for the synthesis of antibacterial compound(s. In conclusion, a novel bacterial strain of Actinobacteria, isolated from the unexplored sea sediment of Alang, Gulf of Khambhat (Gujarat, India showed promising

  1. Antibacterial and Antioxidant Activities of Novel Actinobacteria Strain Isolated from Gulf of Khambhat, Gujarat

    Science.gov (United States)

    Dholakiya, Riddhi N.; Kumar, Raghawendra; Mishra, Avinash; Mody, Kalpana H.; Jha, Bhavanath

    2017-01-01

    Bacterial secondary metabolites possess a wide range of biologically active compounds including antibacterial and antioxidants. In this study, a Gram-positive novel marine Actinobacteria was isolated from sea sediment which showed 84% 16S rRNA gene sequence (KT588655) similarity with Streptomyces variabilis (EU841661) and designated as Streptomyces variabilis RD-5. The genus Streptomyces is considered as a promising source of bioactive secondary metabolites. The isolated novel bacterial strain was characterized by antibacterial characteristics and antioxidant activities. The BIOLOG based analysis suggested that S. variabilis RD-5 utilized a wide range of substrates compared to the reference strain. The result is further supported by statistical analysis such as AWCD (average well color development), heat-map and PCA (principal component analysis). The whole cell fatty acid profiling showed the dominance of iso/anteiso branched C15–C17 long chain fatty acids. The identified strain S. variabilis RD-5 exhibited a broad spectrum of antibacterial activities for the Gram-negative bacteria (Escherichia coli NCIM 2065, Shigella boydii NCIM, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas sp. NCIM 2200 and Salmonella enteritidis NCIM), and Gram-positive bacteria (Bacillus subtilis NCIM 2920 and Staphylococcus aureus MTCC 96). Extract of S. variabilis strain RD-5 showed 82.86 and 89% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and metal chelating activity, respectively, at 5.0 mg/mL. While H2O2 scavenging activity was 74.5% at 0.05 mg/mL concentration. Furthermore, polyketide synthases (PKSs types I and II), an enzyme complex that produces polyketides, the encoding gene(s) detected in the strain RD-5 which may probably involve for the synthesis of antibacterial compound(s). In conclusion, a novel bacterial strain of Actinobacteria, isolated from the unexplored sea sediment of Alang, Gulf of Khambhat (Gujarat), India showed promising

  2. Five Ochna species have high antibacterial activity and more than ten antibacterial compounds

    Directory of Open Access Journals (Sweden)

    Jacobus N. Eloff

    2012-01-01

    Full Text Available New measures to control infections in humans and other animals are continuously being sought because of the increasing resistance of bacteria to antibiotics. In a wide tree screening survey of the antimicrobial activity of extracts of tree leaves (www.up.ac.za/phyto, Ochna pulchra, a small tree found widely in southern Africa, had good antibacterial activity. We therefore investigated the antibacterial activity of acetone leaf extracts of some other available Ochna spp. Antibacterial activity and the number of antibacterial compounds in acetone leaf extracts of Ochna natalitia, Ochna pretoriensis, O. pulchra, Ochna gamostigmata and Ochna serullata were determined with a tetrazolium violet serial microplate dilution assay and bioautography against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis and Pseudomonas aeruginosa, bacteria commonly associated with nosocomial infections. The percentage yields of the extracts varied from 2.5% to 8%. The minimum inhibitory concentrations of the five species ranged from 40 µg/mL to 1250 µg/mL. E. coli was sensitive to all the extracts. The O. pretoriensis extract was the most active with minimum inhibitory concentrations of 0.065 mg/mL and 0.039 mg/mL against E. coli and E. faecalis, respectively. The O. pretoriensis extract also had the highest total activities of 923 mL/g and 1538 mL/g, indicating that the acetone extract from 1 g of dried plant material could be diluted to 923 mL or 1538 mL and would still kill these bacteria. Based on the bioautography results, the two most active species, O. pretoriensis and O. pulchra, contained at least 10 antibacterial compounds with similar Rf values. Some of these antibacterial compounds were polar and others were non-polar. Variation in the chemical composition of the species

  3. Design, synthesis and antibacterial activity of a novel hybrid ...

    African Journals Online (AJOL)

    Antimicrobial peptides produced by many tissues and cell types of invertebrates, insects and humans as part of their innate immune system, have received increasing attention as potential candidates due to their administration as pharmaceutical agents. In the present study, a novel hybrid antimicrobial peptide LFM23 ...

  4. Design, synthesis and antibacterial activity of a novel hybrid ...

    African Journals Online (AJOL)

    ajl user 1

    2012-01-26

    Jan 26, 2012 ... 1College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China. ... Antimicrobial peptides produced by many tissues and cell types of invertebrates, insects and humans as part of ..... In nature, almost all kinds of plants, animals and micro- .... Biopolymers, 65: 254-262.

  5. Antibacterial Activity of Dental Cements Containing Quaternary Ammonium Polyethylenimine Nanoparticles

    International Nuclear Information System (INIS)

    Beyth, N.; Weiss, E.I.; Pilo, R.

    2012-01-01

    Glass ionomer cements (GICs) are commonly used for cementing full cast crown restorations. Regrettably, although the dental cements fill the gap between the tooth and the crown, bacterial micro leakage may occur, resulting in secondary caries. As micro leakage cannot be completely prevented, GCS possessing antibacterial properties are in demand. In the present study the antibacterial activity of insoluble, cross-linked quaternary ammonium polyethylenimine (Qp) nanoparticles incorporated at 1% w/w in two clinically available GCS were studied. The antibacterial activity was tested against Streptococcus mutans and Lactobacillus casei using the direct contact test (Dct) and the agar diffusion test (Ad). Using the direct contact test, antibacterial activity (P<0.05) was found in both tested GICs with incorporated QPEI nanoparticles, the effect lasting for at least one month. However, the ADT showed no inhibition halo in the test bacteria, indicating that the antimicrobial nanoparticles do not diffuse into the agar. The results show that the incorporation of QPEI nanoparticles in glass ionomer cements has a long-lasting antibacterial effect against Streptococcus mutans and Lactobacillus casei. Changing the antibacterial properties of glass ionomer cements by incorporating QPEI antibacterial nanoparticles may prolong the clinical performance of dental crowns.

  6. Future prospects of antibacterial metal nanoparticles as enzyme inhibitor

    International Nuclear Information System (INIS)

    Ahmed, Khan Behlol Ayaz; Raman, Thiagarajan; Veerappan, Anbazhagan

    2016-01-01

    Nanoparticles are being widely used as antibacterial agents with metal nanoparticles emerging as the most efficient antibacterial agents. There have been many studies which have reported the mechanism of antibacterial activity of nanoparticles on bacteria. In this review we aim to emphasize on all the possible mechanisms which are involved in the antibacterial activity of nanoparticles and also to understand their mode of action and role as bacterial enzyme inhibitor by comparing their antibacterial mechanism to that of antibiotics with enzyme inhibition as a major mechanism. With the emergence of widespread antibiotic resistance, nanoparticles offer a better alternative to our conventional arsenal of antibiotics. Once the biological safety of these nanoparticles is addressed, these nanoparticles can be of great medical importance in our fight against bacterial infections. - Highlights: • Mechanisms of antibiotics and metal nanoparticles resemble one another. • Bactericidal mechanisms of NPs are cell wall damage, and ROS generation. • Metal NPs inhibit membrane synthesis enzyme. • NPs can be used as antibacterial agents. • NP as antibacterial strategy important due to widespread antibiotic resistance

  7. Antibacterial Activity of Garlic Extract Against some Pathogenic Animal Bacteria

    Directory of Open Access Journals (Sweden)

    M. Safithri

    2011-12-01

    Full Text Available The antimicrobial activity of garlic extract against Gram-positive and Gram-negative bacterial isolates was well studied. However, reports on antibacterial activity of garlic extract against some pathogenic bacteria in animals in Indonesia, are still limited. Therefore, the aim of this study was to evaluate the antibacterial activity of water and ethanol extracts of garlic against Salmonella typhimurium in chickens, and Streptococcus agalactie, Escherichia coli, and Staphylococcus aureus causing mastitis in dairy cows in Indonesia. A filtrate of fresh garlic was used to determine the antibacterial activity against S. typhimurium at concentrations of 5%, 10%, 20%, 30%, and 40% w/v, whereas, the antibacterial activity of water and ethanol extracts was determined against S. agalactie, E. coli, and S. aureus at concentrations of 5%, 10%, 15%, 20%, and 25% w/v. Results showed that antibacterial activity of 30% garlic filtrate was equivalent to 10% tetracycline. Meanwhile, antibacterial activity of garlic aqueous extract on mastitis bacteria was better than that of the garlic ethanol extract. Aqueous extract of garlic at 20% had the same antibacterial activity as 0.01% ampicillin on mastitis bacteria. Filtrates of fresh garlic can be used to inhibit growth of S. typhimurium and mastitis bacteria.

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

    Directory of Open Access Journals (Sweden)

    Amanpour Raana

    2015-04-01

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

  9. Studies on antibacterial screening of corm of Amorphophallus campanulatus (Roxb.

    Directory of Open Access Journals (Sweden)

    Bhagwan Mariba Waghmare

    2017-05-01

    Full Text Available Objective: To study the antibacterial screening of corm of Amorphophallus campanulatus (Roxb. (A. campanulatus. Methods: Antibacterial activities of methanolic, petroleum ether and ethyl acetate extracts of corm of A. campanulatus were studied by agar diffusion technique to determine in vitro antibacterial activities. The antibacterial activity was measured with respect to the standard antibacterial drug. In addition, minimum inhibitory concentration was also determined by using serial dilution method to determine and evaluate antibacterial potency of test corm extracts of A. campanulatus. Results: The results showed significant antibacterial activities against four pathogenic bacteria. The minimum inhibitory concentration values against test bacteria were found to be remarkable range in bacteria like methicillin-resistant Staphylococcus aureus at concentration 0.25 mg/ well, in Pseudomonas aeruginosa at 0.5 mg/well concentration, in Vibrio cholerae was 2 mg/ well, Streptococcus pyogenes at concentration of 0.5 mg/well and Proteus mirabilis was at concentration of 2 mg/well. Conclusions: The methanolic and petroleum ether extracts are capable to maximum inhibition of the tested pathogenic bacteria.

  10. Antibacterial Effect of Diclofenac Sodium on Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Amin Salemmilani

    2013-01-01

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

  11. Future prospects of antibacterial metal nanoparticles as enzyme inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Khan Behlol Ayaz; Raman, Thiagarajan, E-mail: raman@biotech.sastra.edu; Veerappan, Anbazhagan, E-mail: anbazhagan@scbt.sastra.edu

    2016-11-01

    Nanoparticles are being widely used as antibacterial agents with metal nanoparticles emerging as the most efficient antibacterial agents. There have been many studies which have reported the mechanism of antibacterial activity of nanoparticles on bacteria. In this review we aim to emphasize on all the possible mechanisms which are involved in the antibacterial activity of nanoparticles and also to understand their mode of action and role as bacterial enzyme inhibitor by comparing their antibacterial mechanism to that of antibiotics with enzyme inhibition as a major mechanism. With the emergence of widespread antibiotic resistance, nanoparticles offer a better alternative to our conventional arsenal of antibiotics. Once the biological safety of these nanoparticles is addressed, these nanoparticles can be of great medical importance in our fight against bacterial infections. - Highlights: • Mechanisms of antibiotics and metal nanoparticles resemble one another. • Bactericidal mechanisms of NPs are cell wall damage, and ROS generation. • Metal NPs inhibit membrane synthesis enzyme. • NPs can be used as antibacterial agents. • NP as antibacterial strategy important due to widespread antibiotic resistance.

  12. Antibacterial Activity of Dental Cements Containing Quaternary Ammonium Polyethylenimine Nanoparticles

    Directory of Open Access Journals (Sweden)

    Nurit Beyth

    2012-01-01

    Full Text Available Glass ionomer cements (GICs are commonly used for cementing full cast crown restorations. Regrettably, although the dental cements fill the gap between the tooth and the crown, bacterial microleakage may occur, resulting in secondary caries. As microleakage cannot be completely prevented, GICs possessing antibacterial properties are in demand. In the present study the antibacterial activity of insoluble, cross-linked quaternary ammonium polyethylenimine (QPEI nanoparticles incorporated at 1% w/w in two clinically available GICs were studied. The antibacterial activity was tested against Streptococcus mutans and Lactobacillus casei using the direct contact test (DCT and the agar diffusion test (ADT. Using the direct contact test, antibacterial activity (<0.05 was found in both tested GICs with incorporated QPEI nanoparticles, the effect lasting for at least one month. However, the ADT showed no inhibition halo in the test bacteria, indicating that the antimicrobial nanoparticles do not diffuse into the agar. The results show that the incorporation of QPEI nanoparticles in glass ionomer cements has a long-lasting antibacterial effect against Streptococcus mutans and Lactobacillus casei. Changing the antibacterial properties of glass ionomer cements by incorporating QPEI antibacterial nanoparticles may prolong the clinical performance of dental crowns.

  13. Blue green alga mediated synthesis of gold nanoparticles and its antibacterial efficacy against Gram positive organisms

    Energy Technology Data Exchange (ETDEWEB)

    Uma Suganya, K.S. [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Govindaraju, K., E-mail: govindtu@gmail.com [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Ganesh Kumar, V.; Stalin Dhas, T.; Karthick, V. [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Singaravelu, G. [Nanoscience Division, Department of Zoology, Thiruvalluvar University, Vellore 632115 (India); Elanchezhiyan, M. [Department of Microbiology, Dr ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Chennai 600113 (India)

    2015-02-01

    Biofunctionalized gold nanoparticles (AuNPs) play an important role in design and development of nanomedicine. Synthesis of AuNPs from biogenic materials is environmentally benign and possesses high bacterial inhibition and bactericidal properties. In the present study, blue green alga Spirulina platensis protein mediated synthesis of AuNPs and its antibacterial activity against Gram positive bacteria is discussed. AuNPs were characterized using Ultraviolet–visible (UV–vis) spectroscopy, Fluorescence spectroscopy, Fourier Transform-Infrared (FTIR) spectroscopy, Raman spectroscopy, High Resolution-Transmission Electron Microscopy (HR-TEM) and Energy Dispersive X-ray analysis (EDAX). Stable, well defined AuNPs of smaller and uniform shape with an average size of ∼ 5 nm were obtained. The antibacterial efficacy of protein functionalized AuNPs were tested against Gram positive organisms Bacillus subtilis and Staphylococcus aureus. - Highlights: • Size controlled synthesis of gold nanoparticles from blue green alga Spirulina platensis • Stability of gold nanoparticles at different temperatures • Potent antibacterial efficacy against Gram positive organisms.

  14. Layer-by-Layer (LBL) Self-Assembled Biohybrid Nanomaterials for Efficient Antibacterial Applications.

    Science.gov (United States)

    Wu, Yuanhao; Long, Yubo; Li, Qing-Lan; Han, Shuying; Ma, Jianbiao; Yang, Ying-Wei; Gao, Hui

    2015-08-12

    Although antibiotics have been widely used in clinical applications to treat pathogenic infections at present, the problem of drug-resistance associated with abuse of antibiotics is becoming a potential threat to human beings. We report a biohybrid nanomaterial consisting of antibiotics, enzyme, polymers, hyaluronic acid (HA), and mesoporous silica nanoparticles (MSNs), which exhibits efficient in vitro and in vivo antibacterial activity with good biocompatibility and negligible hemolytic side effect. Herein, biocompatible layer-by-layer (LBL) coated MSNs are designed and crafted to release encapsulated antibiotics, e.g., amoxicillin (AMO), upon triggering with hyaluronidase, produced by various pathogenic Staphylococcus aureus (S. aureus). The LBL coating process comprises lysozyme (Lys), HA, and 1,2-ethanediamine (EDA)-modified polyglycerol methacrylate (PGMA). The Lys and cationic polymers provided multivalent interactions between MSN-Lys-HA-PGMA and bacterial membrane and accordingly immobilized the nanoparticles to facilitate the synergistic effect of these antibacterial agents. Loading process was characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray diffraction spectroscopy (XRD). The minimal inhibition concentration (MIC) of MSN-Lys-HA-PGMA treated to antibiotic resistant bacteria is much lower than that of isodose Lys and AMO. Especially, MSN-Lys-HA-PGMA exhibited good inhibition for pathogens in bacteria-infected wounds in vivo. Therefore, this type of new biohybrid nanomaterials showed great potential as novel antibacterial agents.

  15. Electrospun curcumin-loaded cellulose acetate/polyvinylpyrrolidone fibrous materials with complex architecture and antibacterial activity

    International Nuclear Information System (INIS)

    Tsekova, Petya B.; Spasova, Mariya G.; Manolova, Nevena E.; Markova, Nadya D.; Rashkov, Iliya B.

    2017-01-01

    Novel fibrous materials from cellulose acetate (CA) and polyvinylpyrrolidone (PVP) containing curcumin (Curc) with original design were prepared by one-pot electrospinning or dual spinneret electrospinning. The electrospun materials were characterized by scanning electron microscopy (SEM), fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV–Vis), differential scanning calorimetry (DSC), water contact angle measurements, and microbiological tests. It was found that the incorporation of Curc into the CA and PVP solutions resulted in an increase of the solution viscosity and obtaining fibers with larger diameters (ca. 1.5 μm) compared to the neat CA (ca. 800 nm) and PVP fibers (ca. 500 nm). The incorporation of PVP resulted in increased hydrophilicity of the fibers and in faster Curc release. Curc was found in the amorphous state in the Curc-containing fibers and these mats exhibited antibacterial activity against Staphylococcus aureus (S. aureus). The results suggest that, due to their complex architecture, the obtained new antibacterial materials are suitable for wound dressing applications, which necessitate diverse release behaviors of the bioactive compound. - Highlights: • Novel curcumin-loaded materials based on cellulose acetate and polyvinylpyrrolidone were prepared by electrospinning. • Using one-pot or dual spinneret electrospinning enabled modulating drug release. • The incorporation of polyvinylpyrrolidone resulted in faster curcumin release. • The curcumin-containing mats exhibited antibacterial activity thus rendering them suitable for wound dressing applications.

  16. Electrospun curcumin-loaded cellulose acetate/polyvinylpyrrolidone fibrous materials with complex architecture and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Tsekova, Petya B.; Spasova, Mariya G.; Manolova, Nevena E. [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 103A, BG-1113 Sofia (Bulgaria); Markova, Nadya D. [Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 26, BG-1113 Sofia (Bulgaria); Rashkov, Iliya B., E-mail: rashkov@polymer.bas.bg [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 103A, BG-1113 Sofia (Bulgaria)

    2017-04-01

    Novel fibrous materials from cellulose acetate (CA) and polyvinylpyrrolidone (PVP) containing curcumin (Curc) with original design were prepared by one-pot electrospinning or dual spinneret electrospinning. The electrospun materials were characterized by scanning electron microscopy (SEM), fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV–Vis), differential scanning calorimetry (DSC), water contact angle measurements, and microbiological tests. It was found that the incorporation of Curc into the CA and PVP solutions resulted in an increase of the solution viscosity and obtaining fibers with larger diameters (ca. 1.5 μm) compared to the neat CA (ca. 800 nm) and PVP fibers (ca. 500 nm). The incorporation of PVP resulted in increased hydrophilicity of the fibers and in faster Curc release. Curc was found in the amorphous state in the Curc-containing fibers and these mats exhibited antibacterial activity against Staphylococcus aureus (S. aureus). The results suggest that, due to their complex architecture, the obtained new antibacterial materials are suitable for wound dressing applications, which necessitate diverse release behaviors of the bioactive compound. - Highlights: • Novel curcumin-loaded materials based on cellulose acetate and polyvinylpyrrolidone were prepared by electrospinning. • Using one-pot or dual spinneret electrospinning enabled modulating drug release. • The incorporation of polyvinylpyrrolidone resulted in faster curcumin release. • The curcumin-containing mats exhibited antibacterial activity thus rendering them suitable for wound dressing applications.

  17. Calcium phosphate coating containing silver shows high antibacterial activity and low cytotoxicity and inhibits bacterial adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Yoshiki, E-mail: andoy@jmmc.jp [Division of Microbiology, Department of Pathology and Microbiology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Research Department, Japan Medical Materials Corporation, Uemura Nissei Bldg.9F 3-3-31 Miyahara, Yodogawa-ku, Osaka 532-0003 (Japan); Miyamoto, Hiroshi [Division of Microbiology, Department of Pathology and Microbiology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Noda, Iwao; Sakurai, Nobuko [Research Department, Japan Medical Materials Corporation, Uemura Nissei Bldg.9F 3-3-31 Miyahara, Yodogawa-ku, Osaka 532-0003 (Japan); Akiyama, Tomonori [Division of Microbiology, Department of Pathology and Microbiology, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Yonekura, Yutaka; Shimazaki, Takafumi; Miyazaki, Masaki; Mawatari, Masaaki; Hotokebuchi, Takao [Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan)

    2010-01-01

    Surgical site infection is one of the serious complications of orthopedic implants. In order to reduce the incidence of implant-associated infections, we developed a novel coating technology of calcium phosphate (CP) containing silver (Ag), designated Ag-CP coating, using a thermal spraying technique. In this study, we evaluated the antibacterial efficacy and biological safety of this coating. In vitro antibacterial activity tests showed that the growths of Escherichia coli, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) are completely suppressed on Ag-CP coating. In vitro bacterial adherence tests revealed that the number of adherent bacteria on the surface of this coating is significantly less (p < 0.02) than that on the surface of the CP coating. Moreover, the Ag-CP coating completely inhibits MRSA adhesion [<10 colony-forming units (CFU)] when 10{sup 2} CFU MRSA is inoculated. On the other hand, V79 Chinese hamster lung cells were found to grow on the Ag-CP coating as well as on the CP coating in a cytotoxicity test. These results indicate that the Ag-CP coating on the surface of orthopedic implants exhibits antibacterial activity and inhibits bacterial adhesion without cytotoxicity.

  18. Application of Chitosan as Antibacterial for Pangasius Fillet at Low Temperature Storage

    Directory of Open Access Journals (Sweden)

    Windi Damayanti

    2017-02-01

    Full Text Available AbstractThis research were to obtain the optimal concentration of chitosan as an antibacterial material wich had the longest of storage period of pangasius fillet at low temperature storage (5-10oC. The method used is an experimental method with a completely randomized design, four treatments and three replications. Pangasius fillet was soaked with chitosan 0%, 1%, 2% and 3% for 3 minutes, then packed with styrofoam and plastic wrap and stored at low teperature. The observation were made on day 1st, 3rd, 5th, 6th ,7th, 9th,10th, 11th and 12th. The parameters observed total bacterial colonies, the degree of acidity (pH, weight loss, and antibacterial activity of chitosan using disc diffusion methods. The conclusion of research was that the 2% chitosan is optimal concentration for pangasius fillet storage at a low temperature until day 11th, with a total 6.7 X105 cfu/g of bacterial colonies, pH 6.67 and total 6,78 % of weight loss.Chitosan also has a higher antibacterial capability against Escherichia coli (Gram negative bacteria than Staphylococcus aureus and Bacillus subtilis (Gram positive bacteria.

  19. Application of Chitosan as Antibacterial for Pangasius Fillet at Low Temperature Storage

    Directory of Open Access Journals (Sweden)

    Windi Damayanti

    2016-12-01

    Full Text Available This research was conducted in the Laboratory of Fishery Products Processing, Faculty of Fisheries andMarine Science, University of Padjadjaran, Jatinangor. The purpose of this research is to obtain the optimalconcentration of chitosan as an antibacterial material wich had the longest of storage period of pangasiusfillet at low temperature storage (5-10oC. The method used is an experimental method with a completelyrandomized design, four treatments and three replications. Pangasius fillet was soaked with chitosan 0%,1%, 2% and 3% for 3 minutes, then packed with styrofoam and plastic wrap and stored at low teperature.The observation were made on day 1st, 3rd, 5th, 6th ,7th, 9th,10th, 11th and 12th. The parameters observedtotal bacterial colonies, the degree of acidity (pH, weight loss, and antibacterial activity of chitosan usingdisc diffusion methods. The final conclusion is that the 2% chitosan is optimal concentration for pangasiusfillet storage at a low temperature until day 11th, with a total 6.7 X105 cfu/g of bacterial colonies, pH 6.67 andtotal 6,78 % of weight loss.Chitosan also has a higher antibacterial capability against Escherichia coli (Gramnegative bacteria than Staphylococcus aureus and Bacillus subtilis (Gram positive bacteria.

  20. Combinatorial development of antibacterial Zr-Cu-Al-Ag thin film metallic glasses.

    Science.gov (United States)

    Liu, Yanhui; Padmanabhan, Jagannath; Cheung, Bettina; Liu, Jingbei; Chen, Zheng; Scanley, B Ellen; Wesolowski, Donna; Pressley, Mariyah; Broadbridge, Christine C; Altman, Sidney; Schwarz, Udo D; Kyriakides, Themis R; Schroers, Jan

    2016-05-27

    Metallic alloys are normally composed of multiple constituent elements in order to achieve integration of a plurality of properties required in technological applications. However, conventional alloy development paradigm, by sequential trial-and-error approach, requires completely unrelated strategies to optimize compositions out of a vast phase space, making alloy development time consuming and labor intensive. Here, we challenge the conventional paradigm by proposing a combinatorial strategy that enables parallel screening of a multitude of alloys. Utilizing a typical metallic glass forming alloy system Zr-Cu-Al-Ag as an example, we demonstrate how glass formation and antibacterial activity, two unrelated properties, can be simultaneously characterized and the optimal composition can be efficiently identified. We found that in the Zr-Cu-Al-Ag alloy system fully glassy phase can be obtained in a wide compositional range by co-sputtering, and antibacterial activity is strongly dependent on alloy compositions. Our results indicate that antibacterial activity is sensitive to Cu and Ag while essentially remains unchanged within a wide range of Zr and Al. The proposed strategy not only facilitates development of high-performing alloys, but also provides a tool to unveil the composition dependence of properties in a highly parallel fashion, which helps the development of new materials by design.

  1. Towards a Scalable, Biomimetic, Antibacterial Coating

    Science.gov (United States)

    Dickson, Mary Nora

    Corneal afflictions are the second leading cause of blindness worldwide. When a corneal transplant is unavailable or contraindicated, an artificial cornea device is the only chance to save sight. Bacterial or fungal biofilm build up on artificial cornea devices can lead to serious complications including the need for systemic antibiotic treatment and even explantation. As a result, much emphasis has been placed on anti-adhesion chemical coatings and antibiotic leeching coatings. These methods are not long-lasting, and microorganisms can eventually circumvent these measures. Thus, I have developed a surface topographical antimicrobial coating. Various surface structures including rough surfaces, superhydrophobic surfaces, and the natural surfaces of insects' wings and sharks' skin are promising anti-biofilm candidates, however none meet the criteria necessary for implementation on the surface of an artificial cornea device. In this thesis I: 1) developed scalable fabrication protocols for a library of biomimetic nanostructure polymer surfaces 2) assessed the potential these for poly(methyl methacrylate) nanopillars to kill or prevent formation of biofilm by E. coli bacteria and species of Pseudomonas and Staphylococcus bacteria and improved upon a proposed mechanism for the rupture of Gram-negative bacterial cell walls 3) developed a scalable, commercially viable method for producing antibacterial nanopillars on a curved, PMMA artificial cornea device and 4) developed scalable fabrication protocols for implantation of antibacterial nanopatterned surfaces on the surfaces of thermoplastic polyurethane materials, commonly used in catheter tubings. This project constitutes a first step towards fabrication of the first entirely PMMA artificial cornea device. The major finding of this work is that by precisely controlling the topography of a polymer surface at the nano-scale, we can kill adherent bacteria and prevent biofilm formation of certain pathogenic bacteria

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

    Directory of Open Access Journals (Sweden)

    Masoud Dadashi

    2015-10-01

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

  3. In vivo Antibacterial and Wound Healing Activities of Roman Chamomile (Chamaemelum nobile).

    Science.gov (United States)

    Kazemian, Hossein; Ghafourian, Sobhan; Sadeghifard, Nourkhoda; Houshmandfar, Reza; Badakhsh, Behzad; Taji, Asieh; Shavalipour, Aref; Mohebi, Reza; Ebrahim-Saraie, Hadi Sedigh; Houri, Hamidreza; Heidari, Hamid

    2018-01-01

    Today considerable number of drugs are produced from plants. Several plants with antibacterial and healing applications are used in medicine such as Roman chamomile (Chamaemelum nobile L.). Wound infection is one of the most prevalent infections among infectious diseases around the world. Due to appearance of drug resistance, researchers are now paying attention to medicinal plants. Therefore, this study was designed to investigate the antimicrobial and wound healing properties of C. nobile against Pseudomonas aeruginosa using in vivo conditions. Ethanolic extract of C. nobile was provided using standard method. The 5% C. nobile ointment was prepared by dissolving lyophilized extract in eucerin. Forty five male rats were obtained from Ilam university. After anesthetization and wound creation, wounds were infected by P. aeruginosa. The rats were divided into three groups, group I was treated with C. nobile ointment, group II was treated with tetracycline ointment and the third group was treated with base gel as control group. Antibacterial and wound healing activities of C. nobile ointment were more than tetracycline ointment significantly. Our results indicated that extract of C. nobile had effective antibacterial activity and accelerated the progression of wound healing. Our study indicated that antibacterial and wound healing activities of C. nobile ointment were notable. C. nobile therapy in combination with antibiotics can also be useful because medicinal plants contents operate in synergy with antibiotics. These results revealed the value of plant extracts to control antibiotic resistant bacteria in wound infections. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. A Novel Chimeric Endolysin with Antibacterial Activity against Methicillin-Resistant Staphylococcus aureus.

    Science.gov (United States)

    Haddad Kashani, Hamed; Fahimi, Hossein; Dasteh Goli, Yasaman; Moniri, Rezvan

    2017-01-01

    Cysteine/histidine-dependent amidohydrolase/peptidase (CHAP) and amidase are known as catalytic domains of the bacteriophage-derived endolysin LysK and were previously reported to show lytic activity against methicillin-resistant Staphylococcus aureus (MRSA). In the current study, the in silico design and analysis of chimeric CHAP-amidase model was applied to enhance the stability and solubility of protein, which was achieved through improving the properties of primary, secondary and tertiary structures. The coding gene sequence of the chimeric CHAP-amidase was synthesized and subcloned into the pET-22(+) expression vector, and the recombinant protein was expressed in E. coli BL21 (DE3) strain. Subsequent affinity-based purification yielded ~12 mg soluble protein per liter of E. coli culture. Statistical analysis indicated that concentrations of ≥1 μg/mL of the purified protein have significant antibacterial activity against S. aureus MRSA 252 cells. The engineered chimeric CHAP-amidase exhibited 3.2 log reduction of MRSA 252 cell counts at the concentration of 10 μg/mL. A synergistic interaction between CHAP-amidase and vancomycin was detected by using checkerboard assay and calculating the fractional inhibitory concentration (FIC) index. This synergistic effect was shown by 8-fold reduction in the minimum inhibitory concentration of vancomycin. The chimeric CHAP-amidase displayed strong antibacterial activity against S. aureus, S. epidermidis , and enterococcus . However, it did not indicate any significant antibacterial activity against E. coli and Lactococcus lactis . Taken together, these findings suggest that our chimeric CHAP-amidase might represent potential to be used for the development of efficient antibacterial therapies targeting MRSA and certain Gram-positive bacteria.

  5. Isolation and characterization of cDNA clones for carrot extensin and a proline-rich 33-kDa protein

    International Nuclear Information System (INIS)

    Chen, J.; Varner, J.E.

    1985-01-01

    Extensins are hydroxyproline-rich glycoproteins associated with most dicotyledonous plant cell walls. To isolate cDNA clones encoding extensin, the authors started by isolating poly(A) + RNA from carrot root tissue, and then translating the RNA in vitro, in the presence of tritiated leucine or proline. A 33-kDa peptide was identified in the translation products as a putative extensin precursor. From a cDNA library constructed with poly(A) + RNA from wounded carrots, one cDNA clone (pDC5) was identified that specifically hybridized to poly(A) + RNA encoding this 33-kDa peptide. They isolated three cDNA clones (pDC11, pDC12, and pDC16) from another cDNA library using pCD5 as a probe. DNA sequence data, RNA hybridization analysis, and hybrid released in vitro translation indicate that the cDNA clones pDC11 encodes extensin and that cDNA clones pDC12 and pDC16 encode the 33-kDa peptide, which as yet has an unknown identity and function. The assumption that the 33-kDa peptide was an extensin precursor was invalid. RNA hybridization analysis showed that RNA encoded by both clone types is accumulated upon wounding

  6. Adaptor proteins intersectin 1 and 2 bind similar proline-rich ligands but are differentially recognized by SH2 domain-containing proteins.

    Directory of Open Access Journals (Sweden)

    Olga Novokhatska

    Full Text Available BACKGROUND: Scaffolding proteins of the intersectin (ITSN family, ITSN1 and ITSN2, are crucial for the initiation stage of clathrin-mediated endocytosis. These proteins are closely related but have implications in distinct pathologies. To determine how these proteins could be separated in certain cell pathways we performed a comparative study of ITSNs. METHODOLOGY/PRINCIPAL FINDINGS: We have shown that endogenous ITSN1 and ITSN2 colocalize and form a complex in cells. A structural comparison of five SH3 domains, which mediated most ITSNs protein-protein interactions, demonstrated a similarity of their ligand-binding sites. We showed that the SH3 domains of ITSN2 bound well-established interactors of ITSN1 as well as newly identified ITSNs protein partners. A search for a novel interacting interface revealed multiple tyrosines that could be phosphorylated in ITSN2. Phosphorylation of ITSN2 isoforms but not ITSN1 short isoform was observed in various cell lines. EGF stimulation of HeLa cells enhanced tyrosine phosphorylation of ITSN2 isoforms and enabled their recognition by the SH2 domains of the Fyn, Fgr and Abl1 kinases, the regulatory subunit of PI3K, the adaptor proteins Grb2 and Crk, and phospholipase C gamma. The SH2 domains mentioned were unable to bind ITSN1 short isoform. CONCLUSIONS/SIGNIFICANCE: Our results indicate that during evolution of vertebrates ITSN2 acquired a novel protein-interaction interface that allows its specific recognition by the SH2 domains of signaling proteins. We propose that these data could be important to understand the functional diversity of paralogous ITSN proteins.

  7. Effect of Enamel Matrix Derivative and of Proline-Rich Synthetic Peptides on the Differentiation of Human Mesenchymal Stem Cells Toward the Osteogenic Lineage

    Czech Academy of Sciences Publication Activity Database

    Ramis, J. M.; Rubert, M.; Vondrášek, Jiří; Gaya, A.; Lyngstadaas, S. P.; Monjo, M.

    2012-01-01

    Roč. 18, 11/12 (2012), s. 1253-1263 ISSN 1937-3341 Grant - others:GA ČR(CZ) GAP302/10/0427 Institutional research plan: CEZ:AV0Z40550506 Keywords : bone-marrow-cells * de-novo peptide * in-vitro * structure prediction Subject RIV: EI - Biotechnology ; Bionics

  8. Proline-rich tyrosine kinase 2 (Pyk2) mediates vascular endothelial-cadherin-based cell-cell adhesion by regulating beta-catenin tyrosine phosphorylation

    NARCIS (Netherlands)

    van Buul, Jaap D.; Anthony, Eloise C.; Fernandez-Borja, Mar; Burridge, Keith; Hordijk, Peter L.

    2005-01-01

    Vascular endothelial-cadherin (VE-cadherin) controls endothelial cell-cell adhesion and preserves endothelial integrity. In order to maintain endothelial barrier function, VE-cadherin function is tightly regulated through mechanisms that involve protein phosphorylation and cytoskeletal dynamics.

  9. Antibacterial iodine-supported titanium implants.

    Science.gov (United States)

    Shirai, T; Shimizu, T; Ohtani, K; Zen, Y; Takaya, M; Tsuchiya, H

    2011-04-01

    Deep infection remains a serious complication in orthopedic implant surgery. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. This study focused on evaluating the antibacterial activity of iodine-supported titanium (Ti-I(2)) and its impact on post-implant infection, as well as determining the potential suitability of Ti-I(2) as a biomaterial. External fixation pins were used in this experiment as trial implants because of the ease of making the septic models. The antibacterial activity of the metal was measured using a modification of the Japanese Industrial Standards method. Activity was evaluated by exposing the implants to Staphylococcus aureus or Escherichia coli and comparing reaction of pathogens to Ti-I(2) vs. stainless steel and titanium controls. Ti-I(2) clearly inhibited bacterial colonization more than the control metals. In addition, cytocompatibility was assessed by counting the number of colonies that formed on the metals. The three metals showed the same amount of fibroblast colony formation. Japanese white rabbits were used as an in vivo model. Three pins were inserted into both femora of six rabbits for histological analysis. Pin sites were inspected and graded for infection and inflammation. Fewer signs of infection and inflammatory changes were observed in conjunction with the Ti-I(2) pins. Furthermore, osteoconductivity of the implant was evaluated with osteoid formation surface of the pin. Consecutive bone formation was observed around the Ti-I(2) and titanium pins, while little osteoid formation was found around the stainless steel pins. These findings suggest that Ti-I(2) has antimicrobial activity and exhibits cytocompatibility. Therefore, Ti-I(2) substantially reduces the incidence of implant infection and shows particular promise as a biomaterial. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. Antibacterial properties of 3-(phenylsulfonyl)-2-pyrazinecarbonitrile.

    Science.gov (United States)

    Rajamuthiah, Rajmohan; Jayamani, Elamparithi; Majed, Hiwa; Conery, Annie L; Kim, Wooseong; Kwon, Bumsup; Fuchs, Beth Burgwyn; Kelso, Michael J; Ausubel, Frederick M; Mylonakis, Eleftherios

    2015-11-15

    The emergence of multidrug-resistant bacterial strains has heightened the need for new antimicrobial agents based on novel chemical scaffolds that are able to circumvent current modes of resistance. We recently developed a whole-animal drug-screening methodology in pursuit of this goal and now report the discovery of 3-(phenylsulfonyl)-2-pyrazinecarbonitrile (PSPC) as a novel antibacterial effective against resistant nosocomial pathogens. The minimum inhibitory concentrations (MIC) of PSPC against Staphylococcus aureus and Enterococcus faecium were 4 μg/mL and 8 μg/mL, respectively, whereas the MICs were higher against the Gram-negative bacteria Klebsiella pneumoniae (64 μg/mL), Acinetobacter baumannii (32 μg/mL), Pseudomonas aeruginosa (>64 μg/mL), and Enterobacter spp. (>64 μg/mL). However, co-treatment of PSPC with the efflux pump inhibitor phenylalanine arginyl β-naphthylamide (PAβN) or with sub-inhibitory concentrations of the lipopeptide antibiotic polymyxin B reduced the MICs of PSPC against the Gram-negative strains by >4-fold. A sulfide analog of PSPC (PSPC-1S) showed no antibacterial activity, whereas the sulfoxide analog (PSPC-6S) showed identical activity as PSPC across all strains, confirming structure-dependent activity for PSPC and suggesting a target-based mechanism of action. PSPC displayed dose dependent toxicity to both Caenorhabditis elegans and HEK-293 mammalian cells, culminating with a survival rate of 16% (100 μg/mL) and 8.5% (64 μg/mL), respectively, at the maximum tested concentration. However, PSPC did not result in hemolysis of erythrocytes, even at a concentration of 64 μg/mL. Together these results support PSPC as a new chemotype suitable for further development of new antibiotics against Gram-positive and Gram-negative bacteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Green synthesis, characterization and antibacterial activity of copper ...

    African Journals Online (AJOL)

    Green synthesis, characterization and antibacterial activity of copper nanoparticles using L -ascorbic ... Journal Home > Vol 10, No 3 (2017) > ... In this study, simple, economical, convenient and environmentally-friendly chemical reduction ...

  12. A new screening method for discovering antibacterial agents from ...

    African Journals Online (AJOL)

    A new screening method for discovering antibacterial agents from filamentous fungi. ... African Journal of Biotechnology ... Keywords: Drug-resistant bacterial pathogens, novel antibiotics; screening method, filamentous fungi products ...

  13. Antioxidant and antibacterial properties of Ziziphus mucronata and ...

    African Journals Online (AJOL)

    sulphuric acid reagent, Fehling's solution, concentrated sulphuric acid, ferric chloride, Drangendorff's reagent, acetic anhydride, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), p-iodonitrotetrazolium violet, Methods: Antibacterial activity was evaluated using ...

  14. Antibacterial properties of palladium nanostructures sputtered on polyethylene naphthalate

    Czech Academy of Sciences Publication Activity Database

    Polívková, M.; Válová, M.; Siegel, J.; Rimpelová, S.; Hubáček, Tomáš; Lyutakov, O.; Švorčík, V.

    2015-01-01

    Roč. 5, č. 90 (2015), s. 73767-73774 ISSN 2046-2069 Institutional support: RVO:60077344 Keywords : polymer * palladium sputtering * annealing * nanostructure * antibacterial effect Subject RIV: JJ - Other Materials Impact factor: 3.289, year: 2015

  15. A new screening method for discovering antibacterial agents from ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-04-26

    Apr 26, 2012 ... 1College of Chemistry & Life Science, China Three Gorges University, Yichang ... However, antibacterial drug discovery and development ... Untapped biological ..... gratefully thank Professor David M. Johnson for helpful.

  16. Evaluation of antioxidant, antihemolytic and antibacterial potential of six

    Directory of Open Access Journals (Sweden)

    Eimad dine Tariq Bouhlali

    2016-04-01

    These results suggested that date fruit extract, especially Jihl and Bousrdon extract, is not only an important source of antioxidants, which possess a high protective effect of membrane against free radical, but also a potential source of antibacterial components.

  17. Screening of antibacterial potentials of some medicinal plants from ...

    African Journals Online (AJOL)

    Out of these medicinal plants Caesalpinia bonducella, Gardenia gummifera and ... arabica, Gardenia gummifera and ethanol, methanol extracts of Caesalpinia ... Key words: Antibacterial activity, Melghat, Medicinal Plants, Phytochemical ...

  18. Phytochemicals, antioxidant and antibacterial properties of a lichen ...

    African Journals Online (AJOL)

    MARSHYMARGGIE

    2012-04-17

    Apr 17, 2012 ... done using chemical tests. Antibacterial activities of Cladonia digitata were determined by a disk ... of antimicrobial therapeutics or lead compounds to synthesis of new .... ingredients used in cosmetics. J. Am. Acad. Dermatol ...

  19. antibacterial properties of mangifera indica on staphylococcus aureus.

    African Journals Online (AJOL)

    boaz

    Antibacterial activity of Mangifera indica stem bark extracts was determined using disk ... In disk diffusion method, inhibition zone sizes were used to determine the ...... There is need for lead compounds ... pharmaceutical and cosmetics.

  20. Antibacterial efficacy of raw and commercially available honey

    African Journals Online (AJOL)

    Administrator

    2011-09-19

    Sep 19, 2011 ... Key words: Honey, antibacterial activity, raw honey, commercially available honey, minimum inhibitory ... against pathogenic bacteria, oral bacteria as well as food .... explore the possible benefits of the use of honey among.

  1. Research Note: Comparative antibacterial activities of oil-palm ...

    African Journals Online (AJOL)

    Research Note: Comparative antibacterial activities of oil-palm Elaeis ... The antimicrobial activities liquid pyrolysates (obtained by destructive distillation), their ... respective chloroform fractions which showed higher activities than the crude ...

  2. Antibacterial Properties of Marine Sponges from Mauritius Waters

    African Journals Online (AJOL)

    assay. The extracts were screened for the presence of compounds that could be responsible for bioactivity. ... Keywords: Biemna tubulosa, Stylissa spp., Antibacterial activity, Marine sponges, MIC. Tropical ..... Bio-organic and Med. Chem 2003 ...

  3. Synthesis, characterization and antibacterial activity of new fluorescent chitosan derivatives

    Czech Academy of Sciences Publication Activity Database

    Přichystalová, H.; Almonasy, N.; Abdel-Mohsen, A. M.; Abdel-Rahman, R. M.; Fouda, M. M. G.; Vojtova, L.; Kobera, Libor; Spotz, Z.; Burgert, L.; Jancar, J.

    2014-01-01

    Roč. 65, April (2014), s. 234-240 ISSN 0141-8130 Institutional support: RVO:61389013 Keywords : chitosan derivatives * fluorescence * antibacterial activity Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.858, year: 2014

  4. Antibacterial activity and phytochemical analysis of leaf extracts of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-05

    Jan 5, 2009 ... medicinal plant Lasienthera africanum (“Editan”) and their antibacterial activities against clinical isolates ... parts of Nigeria and many of the herbal remedies have ... drugs abound in various markets today, there is need for.

  5. Chemical composition and antibacterial activity of the essential oil of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-18

    Jul 18, 2008 ... essential oil of Pinus caribaea from Nigeria. O. Oluwadayo ... Key words: Pinus caribbea, Pinaceae, essential oil, β-phellandrene, β-caryophyllene, antibacterial. .... cones of Pinus. Pinea, P. halepensis, P. pinaster and P. nigra.

  6. Antibacterial activity of eight medicinal plants against Diarrhoea ...

    African Journals Online (AJOL)

    The studies involve the phytochemical screening and antibacterial activity of leaf extracts eight medicinal plants. The selected plants were Timarindus indica, Guiera senegalensis, Prosopis africana, Deterium microcarpum, Citrus aurantifolia, Psidium guajava, Acacia nilotica and Momordica charantia. Methanolics and ...

  7. Antibacterial activity of some selected plants traditionally used as ...

    African Journals Online (AJOL)

    SAM

    2014-03-26

    Mar 26, 2014 ... The antibacterial activity was determined using agar well diffusion ... antimicrobial chemotherapeutic agents, but the cost of production of .... Hamilton ex D Don. in the traditional system of medicine ... Based on this, further.

  8. Synthesis, characterization and in vitro antibacterial activity of novel ...

    Indian Academy of Sciences (India)

    MARZIEH ABBASI

    The prepared compounds were screened for antibacterial activity against. Escherichia coli (E. ..... HCl in the presence of phenol phthalein as an indicator. The number of H. + ... correspond to the symmetric and asymmetric SO2 and also C-S ...

  9. Antibacterial activities of three medicinal plants against some gastro ...

    African Journals Online (AJOL)

    ... Klebsiella pneumoniae, Proteus mirabilis, Salmonella typhi, and Shigella ... The antibacterial assay showed that the three plants significantly inhibited all the test ... Bambusa vulgaris, Erigeron floribundus, Fluerya aestuans, medicinal plants ...

  10. Antibacterial activity of watermelon (Citrullus lanatus) seed against ...

    African Journals Online (AJOL)

    Engr Akande

    2015-04-08

    Apr 8, 2015 ... Also, saponins which have been implicated in antimicrobial activity were found to be ... Key words: Watermelon seed, antibacterial, Soxhlet extraction, cold ..... International Centre for Science and High Technology, Trieste, pp.

  11. Antibacterial activities of the crude ethanol extracts of medicinal ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-07-05

    Jul 5, 2010 ... extract. On the other hand, the antimicrobial activity was mainly a function of their chemical ... determine antibacterial properties of these plants extracts .... vancomycin (30 µg); PEN= penicillin G (10 unit); AMP = ampicillin (5.

  12. Screening for antibacterial and antiprotozoal activities of crude ...

    African Journals Online (AJOL)

    The antibacterial properties of organic and aqueous extracts of these plants were determined by the microdilution method and the microplate alamar blue assay against Stenotrophomonas maltophilia, Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, ...

  13. Antibacterial activity of seed extracts of Argemone mexicana L. on ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... Chloroform extract of seeds exhibited varying level of antibacterial activity, with minimum ... et al., 1999; Scheck et al.,. 2006). The glycoside and saponins from Quillaja saponaria and Acacia auriculoformis were found to be.

  14. Antioxidant and antibacterial activities of ethanolic extracts of ...

    African Journals Online (AJOL)

    Antioxidant and antibacterial activities of ethanolic extracts of Asparagus officinalis cv. Mary Washington: Comparison of in vivo and in vitro grown plant bioactivities. Arash Khorasani, Wirakarnain Sani, Koshy Philip, Rosna Mat Taha, Arash Rafat ...

  15. Antibacterial activity of six indigenous Indian plants: Acacia nilotica ...

    African Journals Online (AJOL)

    sunny t

    2016-04-20

    Apr 20, 2016 ... The antibacterial activity of extracts (water, acetone and methanol) from six indigenous Indian plants: Acacia ... attention to traditional methods, looking for novel ... Five grams powder of each plant was equally divided into.

  16. Fabrication and Antibacterial Performance of Nano-silver-Doped ...

    African Journals Online (AJOL)

    NICO

    Human beings are often infected by microorganisms like bacteria, moulds, yeast ... However, antibacterial materials such as zeolites covered with silver ions ... copy (TEM) was recorded using LEO-912 AB and scanning tunnelling microscopy ...

  17. Comparison of antibacterial activity of parent plant of Tylophora ...

    African Journals Online (AJOL)

    Valued Acer Customer

    2013-07-31

    Jul 31, 2013 ... raised plant and its callus. Key words: Tylophora indica, in vitro raised plant and callus, antibacterial activity. .... Callusing was initiated from the cut ends of the explants after 25 days of ..... Glossary of Indian Medicinal. Plants,.

  18. Antibacterial activity and medicinal properties of ginger ( Zingiber ...

    African Journals Online (AJOL)

    . Ginger extracts were obtained using solvents, n-hexane, ethyl acetate, ethanolic soxhlet and water. The extracts were assayed for antibacterial activity and bacterial growth inhibition activity. The results showed that all the extracts except the ...

  19. Phytochemical screening and antibacterial activity of Garcinia kola ...

    African Journals Online (AJOL)

    , Tannin, Saponin, and Cardiac glycoside, Flavonoid, Terpenoid, Phenols, Anthraquinone and Steroid. However, reducing sugar is absent. The antibacterial activity of the extracts against the isolates showed that ethanol extract is more ...

  20. An evaluation of antibacterial activities of Seidenfia rheedii (Sw ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-01

    Dec 1, 2009 ... Key words: Seidenfia rheedii, drug resistance, antibacterial activity. INTRODUCTION ... The plant materials (leaves) were shade dried at 31°C for 10 days. ... purchased from Microbial Type Culture Collection (MTCC), Institute.

  1. Titanium Dioxide-Based Antibacterial Surfaces for Water Treatment

    Science.gov (United States)

    The field of water disinfection is gaining much interest since waterborne diseases caused by pathogenic microorganisms directly endanger human health. Antibacterial surfaces offer a new, ecofriendly technique to reduce the harmful disinfection byproducts that form in medical and ...

  2. Antibacterial and Cytotoxic Activities of Acacia nilotica Lam ...

    African Journals Online (AJOL)

    Erah

    Keywords: Acacia nilotica, ESBLs, MRSA, E. coli, Klebsiella, Antibacterial resistance, Cytotoxicity. Received: ... infectious diseases, is an age-long practice, especially ... used in a variety of infections. ... E. coli K1 [14] and MRSA [15] were used.

  3. Stable isotope-assisted NMR characterization of interaction between lipid A and sarcotoxin IA, a cecropin-type antibacterial peptide

    Energy Technology Data Exchange (ETDEWEB)

    Yagi-Utsumi, Maho [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); Yamaguchi, Yoshiki [Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); Advanced Science Institute, RIKEN, Wako 351-0198 (Japan); Boonsri, Pornthip [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Iguchi, Takeshi [Bioscience Research Laboratory, Fujiya Co., Ltd., Hadano, Kanagawa 257-0031 (Japan); Okemoto, Kazuo [Department of Biochemistry and Cell Biology, National Institute of Infectious Disease, Tokyo 162-8640 (Japan); Natori, Shunji [National Institute of Agrobiological Sciences, Tsukuba 305-8602 (Japan); Kato, Koichi, E-mail: kkatonmr@ims.ac.jp [Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787 (Japan); Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603 (Japan); The Glycoscience Institute, Ochanomizu University, Tokyo 135-0064 (Japan); GLYENCE Co., Ltd., Nagoya 474-0858 (Japan)

    2013-02-08

    Highlights: ► Recombinant sarcotoxin IA was successfully produced with {sup 13}C- and {sup 15}N-labeling. ► Sarcotoxin IA adopts an N-terminal α-helix upon binding to lipid A-embedding micelles. ► Two lysine residues are involved in lipid A-mediated antibacterial activities. -- Abstract: Sarcotoxin IA is a 39-residue cecropin-type peptide from Sarcophaga peregrina. This peptide exhibits antibacterial activity against Gram-negative bacteria through its interaction with lipid A, a core component of lipopolysaccharides. To acquire detailed structural information on this specific interaction, we performed NMR analysis using bacterially expressed sarcotoxin IA analogs with {sup 13}C- and {sup 15}N-labeling along with lipid A-embedding micelles composed of dodecylphosphocholine. By inspecting the stable isotope-assisted NMR data, we revealed that the N-terminal segment (Leu3–Arg18) of sarcotoxin IA formed an amphiphilic α-helix upon its interaction with the aqueous micelles. Furthermore, chemical shift perturbation data indicated that the amino acid residues displayed on this α-helix were involved in the specific interaction with lipid A. On the basis of these data, we successfully identified Lys4 and Lys5 as key residues in the interaction with lipid A and the consequent antibacterial activity. Therefore, these results provide unique information for designing chemotherapeutics based on antibacterial peptide structures.

  4. Design

    DEFF Research Database (Denmark)

    Volf, Mette

    Design - proces & metode iBog®  er enestående i sit fokus på afmystificering og operationalisering af designprocessens flygtige og komplekse karakter. Udgivelsen går bag om designerens daglige arbejde og giver et indblik i den kreative skabelsesproces, som designeren er en del af. Udover et bredt...... indblik i designerens arbejdsmetoder og designparametre giver Design - proces & metode en række eksempler fra anerkendte designvirksomheder, der gør det muligt at komme helt tæt på designerens virkelighed....

  5. Synthesis and comparative antibacterial studies of some benzylidene monosaccharide benzoates

    Directory of Open Access Journals (Sweden)

    Mohammed Matin

    2015-03-01

    Full Text Available Some 4,6-O-benzylidene protected 2,3-di-O-benzoates of methyl a-D-glucopyranoside and methyl a-D-mannopyranoside were prepared. All the compounds (1-7 were screened for in vitro antibacterial activity study against ten human pathogenic bacteria. The study revealed that the benzoylated mannopyranosides (5-7 are more prone towards antibacterial functionalities than that of the glucopyranosides (2-3.

  6. Antibacterial marine bacterium deter luminous vibriosis in shrimp larvae

    OpenAIRE

    Abraham, T.J.

    2004-01-01

    Inhibitory activity of a marine pigmented bacterium - Alteromonas sp. - isolated from Penaeus monodon Fabricius larva against pathogenic and environmental isolates of Vibrio harveyi was studied. All the isolates were inhibited to varying degrees by Alteromonas sp. in vitro. The antibacterial substance produced by the Alteromonas sp. was soluble in organic solvent and closely bound to the external surface of bacterial cells. The antibacterial Alteromonas sp., when allowed to colonize on shrimp...

  7. Antibacterial performance of bovine lactoferrin-fish gelatine electrospun nanocomposites

    OpenAIRE

    Padrão, Jorge; Machado, Raul; Casal, Margarida; Rodrigues, L. R.; Dourado, Fernando; Lanceros-Méndez, S.; Sencadas, V.

    2014-01-01

    Antibacterial performance of bovine lactoferrin-fish gelatine electrospun nanocomposites The alarming increase of antibiotic resistant microorganisms urged the development and synthesis of novel antimicrobial biomaterials, to be employed in a broad range of applications, ranging from food casings to medical devices [1 – 3]. This work describes the processing and characterization of an innovative fully biobased eletrctrospun nanocomposite material displaying antibacterial properties. Its c...

  8. Antibacterial and antiadherent properties of silver dioxide-coated brackets

    OpenAIRE

    Rizwan A Gilani; S M Laxmikanth; C S Ramachandra; Sangeeta L Prasad; Sushruth Shetty; S D Vasudevan

    2017-01-01

    Introduction: Enamel demineralization after fixed orthodontic treatment can occur in 50% of patients. Brackets play a significant role in enamel demineralization. Silver has already been prooved to have antibacterial properties. Hence the present study is conducted to assess the antiadherent and antibacterial properties of photocatalytic silver dioxide (AgO2) surface modified stainless steel orthodontic brackets against S. mutans. Materials and Methods: 80 stainless steel brackets of maxillar...

  9. Honey Antibacterial Effect Boosting Using Origanum vulgare L. Essential Oil

    OpenAIRE

    Imtara, Hamada; Elamine, Youssef; Lyoussi, Badiâa

    2018-01-01

    The appearance of new bacterial strains which cause pathogenic diseases and which are resistant to the most used antibiotics requires probing new antibacterial agents sources. Therefore, the main aim of the present work was to follow the antibacterial activity of honey samples from Palestine and Morocco, after the combination with Origanum vulgare L. essential oil, and figure out whether the honey physicochemical parameters and geographic origin influence the final activity. The results of th...

  10. Design

    Science.gov (United States)

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  11. Characterization and antibacterial properties of porous fibers containing silver ions

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhaoyang; Fan, Chenxu; Tang, Xiaopeng; Zhao, Jianghui; Song, Yanhua; Shao, Zhongbiao [National Engineering Laboratory for Modern Silk, College of Textile and Engineering, Soochow University, 199 Ren-ai Road, Suzhou 215123 (China); Xu, Lan, E-mail: lanxu@suda.edu.cn [National Engineering Laboratory for Modern Silk, College of Textile and Engineering, Soochow University, 199 Ren-ai Road, Suzhou 215123 (China); Nantong Textile Institute of Soochow University, 58 Chong-chuan Road, Nantong 226018 (China)

    2016-11-30

    Highlights: • Antibacterial electrospun PLA porous fibers containing silver ions were prepared. • Porous structure and porosity of PLA/Ag{sup +} porous fibers were investigated. • The antibacterial effects of PLA/Ag{sup +} porous fibers were studied. • The released mechanism of silver ions in the porous fibers was illustrated. • The porous structure could improve the antibacterial properties. - Abstract: Materials prepared on the base of bioactive silver compounds have become more and more popular. In the present work, the surface morphology, structure and properties, of electrospun Polylactide Polylactic acid (PLA) porous fibers containing various ratios of silver ions were investigated by a combination of X-ray photoelectron spectroscopy (XPS), universal testing machine, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and et al. The biological activities of the proposed porous fibers were discussed in view of the released silver ions concentration. Antibacterial properties of these porous fibers were studied using two bacterial strains: Escherichia coli (E. coli) and Methicillin-resistant Staphylococcus aureus (MRSA). Results of the antibacterial testing suggested that PLA porous fibers containing silver ions could be used as potent antibacterial wound dressing materials in the biomedical field.

  12. Morpho-phenological and Antibacterial Characteristics of Aconitum spp.

    Directory of Open Access Journals (Sweden)

    Yoirentomba Meetei SINAM

    2013-05-01

    Full Text Available Aconitum species have been traditionally used as ethnomedicine to cure various ailments. The present study reveals the morpho-phenology and antibacterial property of alkaloid extracts of the two Aconitum species. The morpho-phenological characteristics will be helpful for determining the resource availability. Aconitum nagarum is erect type, whereas, Aconitum elwesii is a climber. Aconitum elwesii grows in advance of A. nagarum in terms of growth, flowering and senescence. Towards the end of the year, when the fruits have ripened, the parent tuber dies off. As a result, the daughter tuber becomes independent and in the following spring, takes over the function of the parent tuber. Aconitum nagarum and A. elwesii were found to contain 4-5 aconitine equivalent (AE mg/g of alkaloid. These alkaloids showed antibacterial activity against different bacterial species including human pathogens, namely, Staphylococcus aureus, Salmonella typhimurium, Bordetella bronchiseptica, Escherichia coli, Bacillus subtilis, Pseudomonas putida, Pseudomonas fluorescence and Xanthomonas campestris. However, the extent of antibacterial activity varied among different bacterial species. The antibacterial activity against S. aureus, B. bronchiseptica, and B. subtilis was bactericidal in nature, whereas, against other tested bacterial species was bacteriostatic. Efficacy of the antibacterial activity of these alkaloids was evaluated by comparing with that of standard antibiotics. Differential localization of the antibacterial principle was observed among the Aconitum species studied.

  13. Light-activated polymethylmethacrylate nanofibers with antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Elashnikov, Roman [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic); Lyutakov, Oleksiy, E-mail: lyutakoo@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic); Ulbrich, Pavel [Department of Biochemistry and Microbiology, University of Chemistry and Technology, 16628 Prague (Czech Republic); Svorcik, Vaclav [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic)

    2016-07-01

    The creation of an antibacterial material with triggerable properties enables us to avoid the overuse or misuse of antibacterial substances and, thus, prevent the emergence of resistant bacterial strains. As a potential light-activated antibacterial material, polymethylmethacrylate (PMMA) nanofibers doped with silver nanoparticles (AgNPs) and meso-tetraphenylporphyrin (TPP) were prepared by electrospinning. TPP was chosen as an effectively reactive oxygen species (ROS) producer. Antibacterial tests on Staphylococcus epidermidis (S. epidermidis) and Enterococcus faecalis (E. faecalis) showed the excellent light-triggerable antibacterial activity of the doped materials. Upon light irradiation at the wavelength corresponding to the TPP absorption peak (405 nm), antibacterial activity dramatically increased, mostly due to the release of AgNPs from the polymer matrix. Furthermore, under prolonged light irradiation, the AgNPs/TPP/PMMA nanofibers, displayed enhanced longevity and photothermal stability. Thus, our results suggest that the proposed material is a promising option for the photodynamic inactivation of bacteria. - Highlights: • The novelty of proposed work can be summared as follow: • Silver nanoparticles/meso-tetraphenylporphyrin embedded polymethylmethacrylate nanofibers were obtained for the first time. • Light triggering of PMMA fibers leads to sufficient release of AgNPs or their agglomeration, depending on the light source. • Release of AgNPs leads to appearance of pronounced antimicrobial activity, which can be switched on/off by the illumination.

  14. Antibacterial properties and mechanisms of gold-silver nanocages

    Science.gov (United States)

    Wang, Yulan; Wan, Jiangshan; Miron, Richard J.; Zhao, Yanbin; Zhang, Yufeng

    2016-05-01

    Despite the number of antibiotics used in routine clinical practice, bacterial infections continue to be one of the most important challenges faced in humans. The main concerns arise from the continuing emergence of antibiotic-resistant bacteria and the difficulties faced with the pharmaceutical development of new antibiotics. Thus, advancements in the avenue of novel antibacterial agents are essential. In this study, gold (Au) was combined with silver (Ag), a well-known antibacterial material, to form silver nanoparticles producing a gold-silver alloy structure with hollow interiors and porous walls (gold-silver nanocage). This novel material was promising in antibacterial applications due to its better biocompatibility than Ag nanoparticles, potential in photothermal effects and drug delivery ability. The gold-silver nanocage was then tested for its antibacterial properties and the mechanism involved leading to its antibacterial properties. This study confirms that this novel gold-silver nanocage has broad-spectrum antibacterial properties exerting its effects through the destruction of the cell membrane, production of reactive oxygen species (ROS) and induction of cell apoptosis. Therefore, we introduce a novel gold-silver nanocage that serves as a potential nanocarrier for the future delivery of antibiotics.

  15. Antibacterial activity of propolins from Taiwanese green propolis

    Directory of Open Access Journals (Sweden)

    Yue-Wen Chen

    2018-04-01

    Full Text Available Taiwanese green propolis is a prenylated flavonoid rich honeybee product and propolins isolated from Taiwanese green propolis exert a broad spectrum of biological activities, such as anti-cancer and anti-oxidant. However, the anti-bacterial effects of Taiwanese green propolis or propolins are still poorly understood. In the current study, the antibacterial effects of Taiwanese green propolis and propolins were evaluated. Results show that the maximum dry matter yields of Taiwanese green propolis were observed in the 95% and 99.5% ethanol extracts compared to other extraction methods. Consistently, the highest concentration of propolins C, D, F and G from Taiwanese green propolis was obtained in 95% and 99.5% ethanol extracts. Propolins inhibited the growth of gram-positive bacterial strains (Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes and Paenibacillus larvae. The average minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of propolins from ethanol extracts were 20 μg/ml. Among the propolins, propolin C had the highest antibacterial activity. Furthermore, Taiwanese green propolis also showed antibacterial activity against methicillin-resistant S. aureus (MRSA. In conclusion, these results demonstrate that Taiwanese green propolis and propolins have significant antibacterial activity, particularly against gram-positive bacterial strains. Keywords: Antibacterial activity, Propolins, Taiwan, Green propolis

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

    Science.gov (United States)

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

    2016-08-01

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

  17. Antibacterial effects and dissolution behavior of six bioactive glasses.

    Science.gov (United States)

    Zhang, Di; Leppäranta, Outi; Munukka, Eveliina; Ylänen, Heimo; Viljanen, Matti K; Eerola, Erkki; Hupa, Mikko; Hupa, Leena

    2010-05-01

    Dissolution behavior of six bioactive glasses was correlated with the antibacterial effects of the same glasses against sixteen clinically important bacterial species. Powdered glasses (<45 microm) were immersed in simulated body fluid (SBF) for 48 h. The pH in the solution inside the glass powder was measured in situ with a microelectrode. After 2, 4, 27, and 48 h, the pH and concentration of ions after removing the particles and mixing the SBF were measured with a normal glass pH electrode and ICP-OES. The bacteria were cultured in broth with the glass powder for up to 4 days, after which the viability of the bacteria was determined. The antibacterial effect of the glasses increased with increasing pH and concentration of alkali ions and thus with increased dissolution tendency of the glasses, but it also depended on the bacterium type. The changes in the concentrations of Si, Ca, Mg, P, and B ions in SBF did not show statistically significant influence on the antibacterial property. Bioactive glasses showed strong antibacterial effects for a wide selection of aerobic bacteria at a high sample concentration (100 mg/mL). The antibacterial effects increased with glass concentration and a concentration of 50 mg/mL (SA/V 185 cm(-1)) was required to generate the bactericidal effects. Understanding the dissolution mechanisms of bioactive glasses is essential when assessing their antibacterial effects. Copyright 2009 Wiley Periodicals, Inc.

  18. Evaluation of antibacterial activity of Prosopis juliflora (SW.) DC. leaves.

    Science.gov (United States)

    Thakur, Rupesh; Singh, Rupal; Saxena, Pooja; Mani, Abin

    2014-01-01

    The ethnobotanical importance of Prosopis juliflora is well-known in the folkloric system of medicine for the treatment of various ailments. Although, the study related to the antibacterial potential of this plant, from Central India is scanty. The in vitro antibacterial activity of Prosopis juliflora leaves collected from the local area was evaluated against ten bacterial type cultures by agar well diffusion assay. The crude extracts prepared by two methods separately with three different solvents were examined for the preliminary antibacterial activity and phytochemical screening, the results of which were used for the choice of solvent and mass extraction of crude extract. Solvent fractionation of crude extract was done employing two sets of solvents namely Set-PCE and Set-HDB which resulted in total, six organic and two aqueous fractions, which were finally subjected to antibacterial activities. Varying degrees of growth inhibition was shown by all the fractions against tested microorganisms. The highest antibacterial activity was observed in aqueous fractions as compared to solvent fractions. Isolation and characterization of the bioactive components can be further done by systematic screening of the most active solvent fraction which could lead to the possible source of new antibacterial agents.

  19. Characterization and antibacterial properties of porous fibers containing silver ions

    International Nuclear Information System (INIS)

    Sun, Zhaoyang; Fan, Chenxu; Tang, Xiaopeng; Zhao, Jianghui; Song, Yanhua; Shao, Zhongbiao; Xu, Lan

    2016-01-01

    Highlights: • Antibacterial electrospun PLA porous fibers containing silver ions were prepared. • Porous structure and porosity of PLA/Ag + porous fibers were investigated. • The antibacterial effects of PLA/Ag + porous fibers were studied. • The released mechanism of silver ions in the porous fibers was illustrated. • The porous structure could improve the antibacterial properties. - Abstract: Materials prepared on the base of bioactive silver compounds have become more and more popular. In the present work, the surface morphology, structure and properties, of electrospun Polylactide Polylactic acid (PLA) porous fibers containing various ratios of silver ions were investigated by a combination of X-ray photoelectron spectroscopy (XPS), universal testing machine, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and et al. The biological activities of the proposed porous fibers were discussed in view of the released silver ions concentration. Antibacterial properties of these porous fibers were studied using two bacterial strains: Escherichia coli (E. coli) and Methicillin-resistant Staphylococcus aureus (MRSA). Results of the antibacterial testing suggested that PLA porous fibers containing silver ions could be used as potent antibacterial wound dressing materials in the biomedical field.

  20. New antibacterials for the treatment of toxoplasmosis; a patent review.

    Science.gov (United States)

    Rodriguez, Juan Bautista; Szajnman, Sergio Hernán

    2012-03-01

    Toxoplasma gondii is an opportunistic protozoan parasite responsible for toxoplasmosis. T. gondii is able to infect a wide range of hosts, particularly humans and warm-blooded animals. Toxoplasmosis can be considered as one of the most prevalent parasitic diseases affecting close to one billion people worldwide, but its current chemotherapy is still deficient and is only effective in the acute phase of the disease. This review covers different approaches to toxoplasmosis chemotherapy focused on the metabolic differences between the host and the parasite. Selective action on different targets such as the isoprenoid pathway, dihydrofolate reductase, T. gondii adenosine kinase, different antibacterials, T. gondii histone deacetylase and calcium-dependent protein kinases is discussed. A new and safe chemotherapy is needed, as T. gondii causes serious morbidity and mortality in pregnant women and immunodeficient patients undergoing chemotherapy. A particular drawback of the available treatments is the lack of efficacy against the tissue cyst of the parasite. During this review a broad scope of several attractive targets for drug design have been presented. In this context, the isoprenoid pathway, dihydrofolate reductase, T. gondii histone deacetylase are promising molecular targets.

  1. Preparation and antibacterial property of silver decorated carbon microspheres

    International Nuclear Information System (INIS)

    Li, Sha; Yan, Xiaoliang; Yang, Zhi; Yang, Yongzhen; Liu, Xuguang; Zou, Jing

    2014-01-01

    Carbon microspheres (CMSs) were prepared by glucose hydrothermal method. The effects of glucose concentration and reaction time on the size and morphology of CMSs were studied. CMSs with surface area of 642.5 m 2 /g and pore size of 0.8 nm were exploited to design hybrid material of CMSs with Ag decoration by radio frequency plasma (RF plasma). A series of investigations using X-ray diffraction, UV–vis spectrometry, Fourier transform infrared spectrometry, X-ray photoelectron spectrometry, thermogravimetric analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy was carried out to characterize the Ag decorated CMSs. RF plasma was employed to reduce Ag + ions to metallic nano-particles with the particle size of 10–20 nm and form a clean metal-support (Ag-CMSs) interface. The mechanism for the structure formation of Ag decorated CMSs was discussed. Plasma produced Ag/CMSs showed antibacterial property and proved suitable for potential biological and environmental applications.

  2. Surface ligand controls silver ion release of nanosilver and its antibacterial activity against Escherichia coli

    Directory of Open Access Journals (Sweden)

    Long Y

    2017-04-01

    Full Text Available Yan-Min Long,1,2 Li-Gang Hu,1,3 Xue-Ting Yan,1,3 Xing-Chen Zhao,1,3 Qun-Fang Zhou,1,3 Yong Cai,2,4 Gui-Bin Jiang1,3 1State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Beijing, China; 2Institute of Environment and Health, Jianghan University, Wuhan, Hubei, China; 3College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China; 4Department of Chemistry and Biochemistry, Southeast Environmental Research Center, Florida International University, Miami, FL, USA Abstract: Understanding the mechanism of nanosilver-dependent antibacterial activity against microorganisms helps optimize the design and usage of the related nanomaterials. In this study, we prepared four kinds of 10 nm-sized silver nanoparticles (AgNPs with dictated surface chemistry by capping different ligands, including citrate, mercaptopropionic acid, mercaptohexanoic acid, and mercaptopropionic sulfonic acid. Their surface-dependent chemistry and antibacterial activities were investigated. Owing to the weak bond to surface Ag, short carbon chain, and low silver ion attraction, citrate-coated AgNPs caused the highest silver ion release and the strongest antibacterial activity against Escherichia coli, when compared to the other tested AgNPs. The study on the underlying antibacterial mechanisms indicated that cellular membrane uptake of Ag, NAD+/NADH ratio increase, and intracellular reactive oxygen species (ROS generation were significantly induced in both AgNP and silver ion exposure groups. The released silver ions from AgNPs inside cells through a Trojan-horse-type mechanism were suggested to interact with respiratory chain proteins on the membrane, interrupt intracellular O2 reduction, and induce ROS production. The further oxidative damages of lipid peroxidation and membrane breakdown caused the lethal effect on E. coli. Altogether, this study demonstrated that AgNPs exerted

  3. Antibacterial agents in composite restorations for the prevention of dental caries.

    Science.gov (United States)

    Pereira-Cenci, Tatiana; Cenci, Maximiliano S; Fedorowicz, Zbys; Azevedo, Marina

    2013-12-17

    assess trial quality using standard Cochrane Collaboration methodologies. We retrieved 308 references to studies, none of which matched the inclusion criteria for this review and all of which were excluded. We were unable to identify any randomised controlled trials on the effects of antibacterial agents incorporated into composite restorations for the prevention of dental caries. The absence of high level evidence for the effectiveness of this intervention emphasises the need for well designed, adequately powered, randomised controlled clinical trials. Thus, conclusions remain the same as the previously published review, with no included clinical trials.

  4. Antibacterial, antimalarial and leishmanicidal activities of Cu (II) and nickel (II) complexes of diclofenac sodium

    International Nuclear Information System (INIS)

    Rehman, F.U.; Khan, M.F.; Khan, G.M.; Khan, H.; Khan, I.U.

    2010-01-01

    Metal complexes are famous for a wide array of chemotherapeutic effects. The current study was designed to synthesize and evaluate unexplored chemotherapeutic effects of Cu (II) and Nickel (II) complexes of the non-steroidal anti-inflammatory drug diclofenac. Nickel complex exhibited significant leishmanicidal activity against Lieshmania major, while the copper complex was found to possess low activity against the same pathogen. Both of the complexes revealed low antibacterial activities and were interestingly failed to produce any considerable antimalarial activity against Plasmodium falciparum 3D7. Selective leishmanicidal activities of Nickel (II) complex of diclofenac needs further improvement to be developed as potential new metal-based leishmanicidal agent.(author)

  5. Antibacterial, antimalarial and leishmanicidal activities of Cu (II) and nickel (II) complexes of diclofenac sodium

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, F U; Khan, M F; Khan, G M; Khan, H [Gomal University, D.I. Khan (Pakistan). Dept. of Faculty of Pharmacy; Khan, I U [University of Peshawar (Pakistan). Dept. of Faculty of Pharmacy

    2010-08-15

    Metal complexes are famous for a wide array of chemotherapeutic effects. The current study was designed to synthesize and evaluate unexplored chemotherapeutic effects of Cu (II) and Nickel (II) complexes of the non-steroidal anti-inflammatory drug diclofenac. Nickel complex exhibited significant leishmanicidal activity against Lieshmania major, while the copper complex was found to possess low activity against the same pathogen. Both of the complexes revealed low antibacterial activities and were interestingly failed to produce any considerable antimalarial activity against Plasmodium falciparum 3D7. Selective leishmanicidal activities of Nickel (II) complex of diclofenac needs further improvement to be developed as potential new metal-based leishmanicidal agent.(author)

  6. Environmental monitoring and assessment of antibacterial metabolite producing actinobacteria screened from marine sediments in south coastal regions of Karnataka, India.

    Science.gov (United States)

    Skariyachan, Sinosh; Garka, Shruthi; Puttaswamy, Sushmitha; Shanbhogue, Shobitha; Devaraju, Raksha; Narayanappa, Rajeswari

    2017-06-01

    Assessment of the therapeutic potential of secondary metabolite producing microorganisms from the marine coastal areas imparts scope and application in the field of environmental monitoring. The present study aims to screen metabolites with antibacterial potential from actionbacteria associated with marine sediments collected from south coastal regions of Karnataka, India. The actinobacteria were isolated and characterized from marine sediments by standard protocol. The metabolites were extracted, and antibacterial potential was analyzed against eight hospital associated bacteria. The selected metabolites were partially characterized by proximate analysis, SDS-PAGE, and FTIR-spectroscopy. The antibiogram of the test clinical isolates revealed that they were emerged as multidrug-resistant strains (P ≤ 0.05). Among six actinobacteria (IS1-1S6) screened, 100 μl -1 metabolite from IS1 showed significant antibacterial activities against all the clinical isolates except Pseudomonas aeruginosa. IS2 demonstrated antimicrobial potential towards Proteus mirabilis, Streptococcus pyogenes, and Escherichia coli. The metabolite from IS3 showed activity against Strep. pyogenes and E. coli. The metabolites from IS4, IS5, and IS6 exhibited antimicrobial activities against Ps. aeruginosa (P ≤ 0.05). The two metabolites that depicted highest antibacterial activities against the test strains were suggested to be antimicrobial peptides with low molecular weight. These isolates were characterized and designated as Streptomyces sp. strain mangaluru01 and Streptomyces sp. mangaloreK01 by 16S ribosomal DNA (rDNA) sequencing. This study suggests that south coastal regions of Karnataka, India, are one of the richest sources of antibacterial metabolites producing actinobacteria and monitoring of these regions for therapeutic intervention plays profound role in healthcare management.

  7. ANTIBACTERIAL ACTIVITY OF GINGER OIL AGAINST FOOD BORN PATHOGENS

    International Nuclear Information System (INIS)

    TAHA, S.M.A.

    2008-01-01

    This study was carried out to investigate the antibacterial activity of ginger oil against Food Born pathogens and the effect of heating, microwave heating and gamma irradiation on microbiological quality and antibacterial activity of ginger oil. Growth and survival of A. hydrophila and L. monocytogenes in broth media and carrot juice with different concentrations of ginger oil was also studied. Gram-negative bacteria were more resistant than gram-positive bacteria. Heating at 80 0 C for 10 min did not change the antibacterial activity of ginger oil, whereas heating at 100 0 C for 5 min and autoclaving at 121 0 C for 15 min caused slight reduction in antibacterial activity in most microorganisms tested. Heating by microwave of ginger oil destroyed its antibacterial activity against B. cereus although it still works against other microorganisms tested. The dose 6 kGy caused slight reduction in antibacterial activity of ginger oil, whereas the dose 10 kGy caused markedly reduction in antibacterial activity of ginger oil against most microorganisms tested. Ginger oil was more effective on L. monocytogenes as compared with its effect on A. hydrophila in tryptone soya broth at 4 0 C or 25 0 C. Supplementation of ginger oil with carrot juice was more effective on A. hydrophila and L. monocytogenes than in tryptone soya broth and this effect was increased with increasing the time of incubation and the concentration of ginger oil. These results support the notion that plant essential oils may have an important role as pharmaceuticals and food preservatives

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

    Science.gov (United States)

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

    2017-08-09

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

  9. Antiseptic mouthwashes: in vitro antibacterial activity.

    Science.gov (United States)

    Watanabe, Evandro; Nascimento, Andresa P; Guerreiro-Tanomaru, Juliane M; Razaboni, Ana M; de Andrade, Denise; Tanomaru-Filho, Mário

    2015-01-01

    Mouthwashes are used as an adjunct to tooth brushing for improving breath and preventing oral diseases. The aim of this study was to compare the in vitro Maximum Inhibitory Dilution (MID) of 3 mouthwashes with different active ingredients against mutans streptococci (MS). The products analyzed were Periogard®, Cepacol® and Plax® Fresh Mint. Their antibacterial activity was assessed in duplicate in 96-well microtiter plates against 36 clinical isolates of MS. Each mouthwash was submitted to a serial two-fold dilution (1/2.5 to 1/5120) using double concentration of Tryptose Soy Broth with 1.0% yeast extract. The final volume in each well was 100 mL plus 5 mL of a bacterial suspension, equivalent to 107 CFU/mL. They were incubated microaerobically at 37 °C for 48 hours and the MIDs determined. MID was 1/320 for Periogard® and Cepacol®, and 1/20 for PlaxR® Statistical analysis revealed that the MID of Periogard® MID did not differ from that of Cepacol® (p>0.05), and was higher than that of Plax® (pantiseptic mouthwashes containing chlorhexidine (Periogard®) and cetylpyridinium chloride (Cepacol®) had higher in vitroantibacterial activity (MID) against MS than the antiseptic mouthwash containing triclosan (Plax®), according to microbiological method employed.

  10. Antibacterial mechanism of fraxetin against Staphylococcus aureus

    Science.gov (United States)

    WANG, HAITING; ZOU, DAN; XIE, KUNPEING; XIE, MINGJIE

    2014-01-01

    Fraxetin is one of the main constituents of the traditional medicinal plant Fraxinus rhynchophylla. The inhibitory effect of fraxetin on various bacterial strains has been extensively reported, however, its mechanism of action on bacterial cells remains to be elucidated. In the present study, the antibacterial mechanism of fraxetin on Staphylococcus aureus was systematically investigated by examining its effect on cell membranes, protein synthesis, nucleic acid content and topoisomerase activity. The results indicated that fraxetin increased the permeability of the cell membrane but did not render it permeable to macromolecules, such as DNA and RNA. Additionally, the quantity of protein, DNA and RNA decreased to 55.74, 33.86 and 48.96%, respectively following treatment with fraxetin for 16 h. The activity of topoisomerase I and topoisomerase II were also markedly inhibited as fraxetin concentration increased. The result of the ultraviolet-visible spectrophotometry demonstrated that the DNA characteristics exhibited a blue shift and hypochromic effect following treatment with fraxetin. These results indicated that fraxetin had a marked inhibitory effect on S.aureus proliferation. Further mechanistic studies showed that fraxetin could disrupt nucleic acid and protein synthesis by preventing topoisomerase from binding to DNA. PMID:25189268

  11. Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Pettiway, Keon

    2017-01-01

    In this chapter, Ole B. Jensen takes a situational approach to mobilities to examine how ordinary life activities are structured by technology and design. Using “staging mobilities” as a theoretical approach, Jensen considers mobilities as overlapping, actions, interactions and decisions by desig...... by providing ideas about future research for investigating mobilities in situ as a kind of “staging,” which he notes is influenced by the “material turn” in social sciences....... with a brief description of how movement is studied within social sciences after the “mobilities turn” versus the idea of physical movement in transport geography and engineering. He then explains how “mobilities design” was derived from connections between traffic and architecture. Jensen concludes...

  12. Selective etching of injection molded zirconia-toughened alumina: Towards osseointegrated and antibacterial ceramic implants.

    Science.gov (United States)

    Flamant, Quentin; Caravaca, Carlos; Meille, Sylvain; Gremillard, Laurent; Chevalier, Jérôme; Biotteau-Deheuvels, Katia; Kuntz, Meinhard; Chandrawati, Rona; Herrmann, Inge K; Spicer, Christopher D; Stevens, Molly M; Anglada, Marc

    2016-12-01

    Due to their outstanding mechanical properties and excellent biocompatibility, zirconia-toughened alumina (ZTA) ceramics have become the gold standard in orthopedics for the fabrication of ceramic bearing components over the last decade. However, ZTA is bioinert, which hampers its implantation in direct contact with bone. Furthermore, periprosthetic joint infections are now the leading cause of failure for joint arthroplasty prostheses. To address both issues, an improved surface design is required: a controlled micro- and nano-roughness can promote osseointegration and limit bacterial adhesion whereas surface porosity allows loading and delivery of antibacterial compounds. In this work, we developed an integrated strategy aiming to provide both osseointegrative and antibacterial properties to ZTA surfaces. The micro-topography was controlled by injection molding. Meanwhile a novel process involving the selective dissolution of zirconia (selective etching) was used to produce nano-roughness and interconnected nanoporosity. Potential utilization of the porosity for loading and delivery of antibiotic molecules was demonstrated, and the impact of selective etching on mechanical properties and hydrothermal stability was shown to be limited. The combination of injection molding and selective etching thus appears promising for fabricating a new generation of ZTA components implantable in direct contact with bone. Zirconia-toughened alumina (ZTA) is the current gold standard for the fabrication of orthopedic ceramic components. In the present work, we propose an innovative strategy to provide both osseointegrative and antibacterial properties to ZTA surfaces: we demonstrate that injection molding allows a flexible design of surface micro-topography and can be combined with selective etching, a novel process that induces nano-roughness and surface interconnected porosity without the need for coating, avoiding reliability issues. These surface modifications have the

  13. Characterization of antibacterial polyethersulfone membranes using the respiration activity monitoring system (RAMOS)

    NARCIS (Netherlands)

    Kochan, J.; Scheidle, M.; Erkel, J. van; Bikel, M.; Büchs, J.; Wong, J.E.; Melin, T.; Wessling, M.

    2012-01-01

    Membranes with antibacterial properties were developed using surface modification of polyethersulfone ultrafiltration membranes. Three different modification strategies using polyelectrolyte layer-by-layer (LbL) technique are described. The first strategy relying on the intrinsic antibacterial

  14. Antibacterial characteristics of anthocyanins extracted from wild blueberries against foodborne pathogens

    Science.gov (United States)

    Wild blueberries have rich bioactive compounds, such as polyphenols, phenolics and organic acids. Previous studies demonstrated the antibacterial activity of blueberries against the growth of pathogenic bacteria. The objective of this study was to evaluate the antibacterial characteristics and mech...

  15. Comparative analysis of antibacterial activity of povidone iodine and homoeopathic mother tinctures as antiseptics

    Directory of Open Access Journals (Sweden)

    Muhammad Mohsin Zaman

    2016-01-01

    Conclusion: This study confirms the antibacterial activity and more effectiveness of Thuja occidentalis and Rhus glabra mother tinctures than povidone iodine. The other tested mother tinctures also have antibacterial activity against tested bacteria, except Echinacea.

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

    Directory of Open Access Journals (Sweden)

    Hassan Habibi

    2017-05-01

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

  17. Antibacterial activity of the latex of Argemone ochroleuca Sweet

    International Nuclear Information System (INIS)

    Saad A. Alamri; Mahmoud F. Moustafa

    2010-01-01

    To investigate the antibacterial effect of the crude latex of Argemone ochroleuca (A. ochroleuca) as antibacterial potential against a range of human pathogenic bacteria. This study was carried out at King Khalid University, Abha, Kingdom of Saudi Arabia from January to March 2010. Seventeen ml of fresh latex from A. ochroleuca Sweet was collected, and the antibacterial activity of crude and diluted latex were examined using one ml of standardized inoculum suspension, and using the agar diffusion method test against Bacillus subtilis, Enterobacter aerogenes, Micrococcus luteus, Escherichia coli, and Staphylococcus aureus. All inoculated plates were incubated aerobically at 290C for 48 hours. The diameter of the zones of inhibition was measured to the nearest mm. The crude latex of A. ochroleuca exhibited a potent antibacterial effect on all bacterial strains examined. The zones of inhibition against the tested bacteria were found in the range of 9.30 - 40.3 mm along with their respective minimum inhibitory concentration values 100 ul/ml. The observable inhibition on selected bacteria by latex of A. ochroleuca makes it a promising alternative as a potential source of natural antibacterial (Author).

  18. Antibacterial Properties of Silver-Loaded Plasma Polymer Coatings

    International Nuclear Information System (INIS)

    Ploux, L.; Mateescu, M.; Anselme, K.; Vasilev, K.

    2012-01-01

    In a previous paper, we proposed new silver nanoparticles (SNPs) based antibacterial coatings able to protect eukaryotic cells from SNPs related toxic effects, while preserving antibacterial efficiency. A SNPs containing n-heptylamine (HA) polymer matrix was deposited by plasma polymerization and coated by a second HA layer. In this paper, we elucidate the antibacterial action of these new coatings. We demonstrated that SNPs-loaded material can be covered by thin HA polymer layer without losing the antibacterial activity to planktonic bacteria living in the near surroundings of the material. SNPs-containing materials also revealed antibacterial effect on adhered bacteria. Adhered bacteria number was significantly reduced compared to pure HA plasma polymer and the physiology of the bacteria was affected. The number of adhered bacteria directly decreased with thickness of the second HA layer. Surprisingly, the quantity of cultivable bacteria harvested by transfer to nutritive agar decreased not only with the presence of SNPs, but also in relation to the covering HA layer thickness, that is, oppositely to the increase in adhered bacteria number. Two hypotheses are proposed for this surprising result (stronger attachment or weaker vitality), which raises the question of the diverse potential ways of action of SNPs entrapped in a polymer matrix.

  19. Antibacterial Activity of Germacrane Type Sesquiterpenes from Curcuma heyneana Rhizomes

    Directory of Open Access Journals (Sweden)

    Hartiwi Diastuti

    2014-03-01

    Full Text Available The isolation of terpenoids from C. heyneana rhizomes and their antibacterial activity have been conducted. The terpenoids were isolated by using vacuum liquid chromatography and radial chromatography. The structures of the compounds were determined based on spectroscopic data (1H-NMR, 13C-NMR (1D and 2D. The antibacterial activity was carried out by using microdilution method and evaluated against eight bacteria. Three germacrane type sesquiterpenes have been isolated from C. heyneana rhizhomes and were identified as germacrone, dehydrocurdione, and 1(10,4(5-diepoxygermacrone. Germacrone showed highest antibacterial activity against P. aeruginosa with MIC values of 15.6 µg/mL and MBC values 31.2 µg/mL. Dehydrocurdione showed highest antibacterial activity against B. subtilis with MIC values of 31.2 µg/mL and MBC values of 31.2 µg/mL. However, 1(10,4(5-diepoxygermacrone showed a weak antibacterial activity.

  20. A technology for developing synbodies with antibacterial activity.

    Directory of Open Access Journals (Sweden)

    Valeriy Domenyuk

    Full Text Available The rise in antibiotic resistance has led to an increased research focus on discovery of new antibacterial candidates. While broad-spectrum antibiotics are widely pursued, there is evidence that resistance arises in part from the wide spread use of these antibiotics. Our group has developed a system to produce protein affinity agents, called synbodies, which have high affinity and specificity for their target. In this report, we describe the adaptation of this system to produce new antibacterial candidates towards a target bacterium. The system functions by screening target bacteria against an array of 10,000 random sequence peptides and, using a combination of membrane labeling and intracellular dyes, we identified peptides with target specific binding or killing functions. Binding and lytic peptides were identified in this manner and in vitro tests confirmed the activity of the lead peptides. A peptide with antibacterial activity was linked to a peptide specifically binding Staphylococcus aureus to create a synbody with increased antibacterial activity. Subsequent tests showed that this peptide could block S. aureus induced killing of HEK293 cells in a co-culture experiment. These results demonstrate the feasibility of using the synbody system to discover new antibacterial candidate agents.

  1. Plaque-left-behind after brushing: intra-oral reservoir for antibacterial toothpaste ingredients

    OpenAIRE

    Otten, Marieke P. T.; Busscher, Henk J.; Abbas, Frank; van der Mei, Henny C.; van Hoogmoed, Chris G.

    2012-01-01

    Objectives Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims. Materials and methods First, volunteers brushed 2 weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12 h af...

  2. ANTIBACTERIAL PROPERTIES OF PHARMACEUTICAL COMPOSITION OF HEPATOPROTECTORS

    Directory of Open Access Journals (Sweden)

    Aslanian MA

    2016-12-01

    Full Text Available Pathology problemof hepatobiliary system (HBS of contagious origin becomes relevant with the increase of disturbance and complications of lipid metabolism and bile pigments among young people. Leading role in prophylaxis and treatment in the context of this pathology belongs to antibacterialc hemotherapeutic agents. However, along with antimicrobial activity, numerous side effects can be observed during treatment with antibacterial agents. According to the recent study on hepatobiliary system (HBS, therapeutic effect can be seen only while using herbal medicine with choleretic action as well as their various compositions.Amountof medicine with the appropriate effect is insufficient, that is why the study was conducted towards finding effective combinations of plant substances of different groups for the purpose of creatingan effective medicine for treatment of hepatobiliary system (HBS of contagious origin. Aim of the work The purpose of study was to examine antibacterial properties of different combinations with flamin and lavender oil in combined medicine during the course of treatment of cholecystitis and cholangitis. Materials and methods. It the result of study 61 microbial strains were distinguished and identified from the pathological material taken from 53 patients with cholecystitis and cholangitis. All distinguished clinical microbial strains taken from the patients were tested for sensitivity to combined medicine in the form of tablets with flamin and lavender oil. Minimal inhibitory concentration for S. aureus АТСС 25923 amounted to 250-350 ug/ml, for E. coli АТСС 25922 - 350±50,0 ug/ml, for P. aeruginosa АТСС 27853 750±100,0 ug/ml, for Р. vulgaris АТСС 4636 - 850±100,0 ug/ml, minimal inhibitory concentration to the tablets № 2 та № 3 amounted to > 1000 мкг/мл. Minimal inhibitory concentration for B. subtilis АТСС 6633 amounted to 250±50,0 ug/ml, for C. albicans ATCC 885/653 300±50,0 ug

  3. Preparation and antibacterial activity of Ag–TiO 2 composite film by ...

    Indian Academy of Sciences (India)

    From these analyses, it was found that silver ions were trapped in TiO2 matrix and their reduction could be achieved at 600°C annealing temperature. The antibacterial activity against S. aureus and . coli has been studied applying the so called antibacterial-drop test. The Ag–TiO2 thin films exhibited a high antibacterial ...

  4. Studies on the antibacterial activity of dodecylglycerol

    International Nuclear Information System (INIS)

    Brissette, J.L.

    1985-01-01

    The antimicrobial activity of lipids has been known for many years, with dodecanoylglycerol (dodecanoic acid esterified to glycerol) being one of the most potential. However, the antibacterial potency of dodecylglycerol (DDG), the corresponding 1-O-alkyl glycerol ether, is considerably greater. The superior efficacy of DDG can be attributed, at least in part, to the greater chemical and metabolic stability of the ether bond as compared to esters. In an attempt towards elucidating the mode of action of DDG, the effect of DDG on bacterial lipid metabolism was examined using Streptococcus mutans BHT, a tolerant bacterium. The metabolic fate of the ether was also determined with the use of three radioactive tracers, 14 C-glycerol, 32 Pi, and 14 C-DDG. Treatment of exponentially growing cultures of S. mutans BHI with growth inhibitory concentrations of DDG (10 and 20 μg/ml) inhibited the incorporation of 14 C-glycerol into lipid. In vivo studies using 14 C-DDG showed that the 14 C-ether was readily incorporated almost exclusively into phosphatidic (PA) and lysophosphatidic (LPA) acids. When cells prelabelled with either 14 C-glycerol or 32 Pi were exposed to 10 and 20 + g/ml DDG for 2 h, the accumulation of PA and diphosphatidylglycerol (diPG) was greatly stimulated. However, diPG accumulated at the expense of its precursor, glycerol, which greatly decreased. These data suggest that the ether-containing PA inhibits the synthesis of CDP-diglyceride. Moreover, these results clearly demonstrate that DDG functions as a metabolic rather than physical effector, disputing the conventional notion that bactericidal lipids act as detergents, physically dissolving the cellular envelope

  5. Facts and myths of antibacterial properties of silk.

    Science.gov (United States)

    Kaur, Jasjeet; Rajkhowa, Rangam; Afrin, Tarannum; Tsuzuki, Takuya; Wang, Xungai

    2014-03-01

    Silk cocoons provide protection to silkworm from biotic and abiotic hazards during the immobile pupal phase of the lifecycle of silkworms. Protection is particularly important for the wild silk cocoons reared in an open and harsh environment. To understand whether some of the cocoon components resist growth of microorganisms, in vitro studies were performed using gram negative bacteria Escherichia coli (E. coli) to investigate antibacterial properties of silk fiber, silk gum, and calcium oxalate crystals embedded inside some cocoons. The results show that the previously reported antibacterial properties of silk cocoons are actually due to residues of chemicals used to isolate/purify cocoon elements, and properly isolated silk fiber, gum, and embedded crystals free from such residues do not have inherent resistance to E. coli. This study removes the uncertainty created by previous studies over the presence of antibacterial properties of silk cocoons, particularly the silk gum and sericin. Copyright © 2013 Wiley Periodicals, Inc.

  6. Antibacterial gold nanoparticles-biomass assisted synthesis and characterization.

    Science.gov (United States)

    Badwaik, Vivek D; Willis, Chad B; Pender, Dillon S; Paripelly, Rammohan; Shah, Monic; Kherde, Yogesh A; Vangala, Lakshmisri M; Gonzalez, Matthew S; Dakshinamurthy, Rajalingam

    2013-10-01

    Xylose is a natural monosaccharide found in biomass such as straw, pecan shells, cottonseed hulls, and corncobs. Using this monosaccharide, we report the facile, green synthesis and characterization of stable xylose encapsulated gold nanoparticles (Xyl-GNPs) with potent antibacterial activity. Xyl-GNPs were synthesized using the reduction property of xylose in an aqueous solution containing choloraurate anions carried out at room temperature and atmospheric pressure. These nanoparticles were stable and near spherical in shape with an average diameter of 15 +/- 5 nm. Microbiological assay results showed the concentration dependent antibacterial activity of these particles against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus epidermidis) bacteria. Thus the facile, environmentally friendly Xyl-GNPs have many potential applications in chemical and biomedical industries, particularly in the development of antibacterial agents in the field of biomedicine.

  7. Antibacterial and antioxidant activities of Licania tomentosa (Benth. fritsch (crhysobalanaceae

    Directory of Open Access Journals (Sweden)

    Silva J.B.N.F.

    2012-01-01

    Full Text Available This work describes the chemical composition, and evaluates the antimicrobial and antioxidant activities of a hydroalcoholic extract from the leaves of the Licania tomentosa. Gram positive and negative bacterial strains were used in this work. Examination of the phytochemical composition of L. tomentosa revealed the presence of secondary metabolites such as tannins, flavonoids, saponins, alkaloids, steroids and triterpenoids. An antibacterial assay pointed out that the extract had a lower minimal inhibitory concentration (MIC - 32 μg/mL towards Staphylococcus aureus (ATCC12692. The extract also presented antibacterial activity against other assayed bacteria, with the MIC varying between 64 and 512 μg/ mL. Our findings reveal that the extract presented an antioxidative capacity lower than that of BHT at the same concentration, used as positive control. Our results suggest that the levels and combinations between the secondary metabolites of this plant should be investigated to explain the demonstrated antibacterial activity.

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

    Directory of Open Access Journals (Sweden)

    Claudia Pasca

    2016-11-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-15

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

  11. Novel orthodontic cement containing dimethylaminohexadecyl methacrylate with strong antibacterial capability.

    Science.gov (United States)

    Feng, Xiaodong; Zhang, Ning; Xu, Hockin H K; Weir, Michael D; Melo, Mary Anne S; Bai, Yuxing; Zhang, Ke

    2017-09-26

    Orthodontic treatments increase the incidence of white spot lesions. The objectives of this study were to develop an antibacterial orthodontic cement to inhibit demineralization, and to evaluate its enamel shear bond strength and anti-biofilm properties. Novel antibacterial monomer dimethylaminohexadecyl methacrylate (DMAHDM) was synthesized and incorporated into Transbond XT at 0, 1.5 and 3% by mass. Anti-biofilm activity was assessed using a human dental plaque microcosm biofilm model. Shear bond strength and adhesive remnant index were also tested. Biofilm activity precipitously dropped when contacting orthodontic cement with DMAHDM. Orthodontic cement containing 3% DMAHDM significantly reduced biofilm metabolic activity and lactic acid production (p0.1). By incorporating DMAHDM into Transbond XT for the first time, the modified orthodontic cement obtained a strong antibacterial capability without compromising the enamel bond strength.

  12. Lateral dimension-dependent antibacterial activity of graphene oxide sheets.

    Science.gov (United States)

    Liu, Shaobin; Hu, Ming; Zeng, Tingying Helen; Wu, Ran; Jiang, Rongrong; Wei, Jun; Wang, Liang; Kong, Jing; Chen, Yuan

    2012-08-21

    Graphene oxide (GO) is a promising precursor to produce graphene-family nanomaterials for various applications. Their potential health and environmental impacts need a good understanding of their cellular interactions. Many factors may influence their biological interactions with cells, and the lateral dimension of GO sheets is one of the most relevant material properties. In this study, a model bacterium, Escherichia coli ( E. coli ), was used to evaluate the antibacterial activity of well-dispersed GO sheets, whose lateral size differs by more than 100 times. Our results show that the antibacterial activity of GO sheets toward E. coli cells is lateral size dependent. Larger GO sheets show stronger antibacterial activity than do smaller ones, and they have different time- and concentration-dependent antibacterial activities. Large GO sheets lead to most cell loss after 1 h incubation, and their concentration strongly influences antibacterial activity at relative low concentration (oxidation capacity toward glutathione is similar, consistent with X-ray photoelectron spectroscopy and ultraviolet-visible absorption spectroscopy results. This suggests the lateral size-dependent antibacterial activity of GO sheets is caused by neither their aggregation states, nor oxidation capacity. Atomic force microscope analysis of GO sheets and cells shows that GO sheets interact strongly with cells. Large GO sheets more easily cover cells, and cells cannot proliferate once fully covered, resulting in the cell viability loss observed in the followed colony counting test. In contrast, small GO sheets adhere to the bacterial surfaces, which cannot effectively isolate cells from environment. This study highlights the importance of tailoring the lateral dimension of GO sheets to optimize the application potential with minimal risks for environmental health and safety.

  13. Consumption of antibacterial molecules in broiler production in Morocco.

    Science.gov (United States)

    Rahmatallah, Naoufal; El Rhaffouli, Hicham; Lahlou Amine, Idriss; Sekhsokh, Yassine; Fassi Fihri, Ouafaa; El Houadfi, Mohammed

    2018-05-01

    Monitoring the use of antibacterial agents in food-producing animals is crucial in order to reduce antimicrobial resistance, selection and dissemination of resistant bacterial strains, and drug residues in the animal food products. The broiler production sector is considered a great consumer of antibacterials and incriminated in the rise of antimicrobial resistance level in zoonotic bacterial pathogens such as Escherichia coli, Salmonella and Campylobacter. Following recommendations from the OIE and WHO, a survey was conducted about the use and consumption of several antibacterial agents in Moroccan broiler flocks. More than 5 million broilers were randomly surveyed at the prescriber level, that is, via the veterinary clinics involved in their health management. The results showed that 93% of the flocks received at least one antibacterial treatment of minimum 3 days duration. Enrofloxacin, colistin and trimethoprim/sulphonamides were the most used antibacterials followed by oxytetracycline, florfenicol and amoxicillin. Oxytetracycline, enrofloxacin and colistin were overdosed in most of the administration, while amoxicillin and the combination of trimethoprim/sulphonamides were under-dosed. The total amount of antibacterial consumed in the survey was 63.48 mg/kg and the Animal Level of Exposure to Antimicrobials (ALEA) was 94.45%. The reasons for this frequent use were related mainly to the poor quality of broiler production management. Chicks and animal feed provided to producers were of variable quality. Management of rearing stock density was often poor and biosecurity inadequate, and broilers were challenged by a high prevalence of infectious diseases. © 2018 The Authors. Veterinary Medicine and Science Published by John Wiley & Sons Ltd.

  14. Emerging trends in the discovery of natural product antibacterials

    DEFF Research Database (Denmark)

    Bologa, Cristian G; Ursu, Oleg; Oprea, Tudor

    2013-01-01

    This article highlights current trends and advances in exploiting natural sources for the deployment of novel and potent anti-infective countermeasures. The key challenge is to therapeutically target bacterial pathogens that exhibit a variety of puzzling and evolutionarily complex resistance...... mechanisms. Special emphasis is given to the strengths, weaknesses, and opportunities in the natural product antibacterial drug discovery arena, and to emerging applications driven by advances in bioinformatics, chemical biology, and synthetic biology in concert with exploiting bacterial phenotypes....... These efforts have identified a critical mass of natural product antibacterial lead compounds and discovery technologies with high probability of successful implementation against emerging bacterial pathogens....

  15. Synthesis, Antibacterial and Antifungal Activities of s Derivatives

    Directory of Open Access Journals (Sweden)

    B. B. Baldaniya

    2009-01-01

    Full Text Available Several Nʹ-{4-[(3-chloro-4-fluorophenyl amino]-6-[(-aryl amino] -1, 3, 5-triazin-2-yl} isonicotinohydrazides (6a-r and N2-(Aryl-N4, N6-dipyrimidin-2-yl-1,3,5-triazine-2,4,6-triamines (4a-o were prepared. All newly synthesized compounds have been tested for their antibacterial activity against gram (+ve and gram (-ve bacteria and also on different strains of fungi. Introduction of -OH, -OCH3, -NO2, -Cl and -Br groups to the heterocyclic frame work enhanced antibacterial and antifungal activities.

  16. Optimizing the extraction of antibacterial compounds from pineapple leaf fiber

    Directory of Open Access Journals (Sweden)

    Zhuang Zhikai

    2016-01-01

    Full Text Available Five different solvents (petroleum ether, chloroform, ethyl acetate, acetone, and distilled water were used to extract antibacterial compounds from pineapple leaf fiber. Compounds extracted using acetone showed the greatest antibacterial effect against Escherichia coli, measured by inhibition zone diameter. Three extraction parameters including temperature, time and solid-liquid ratio were optimized through orthogonal experiment based on single factor investigations for achieving maximum active substance extraction rate and bacteriostatic effect. Results showed that using acetone, the optimum extraction conditions for temperature, time and solid-liquid ratio were 45°C, 8 h, and 1:40 (g/ml, respectively.

  17. Antibacterial activity of kecombrang flower extract (Nicolaia speciosa) microencapsulation with food additive materials formulation

    Science.gov (United States)

    Naufalin, R.; Rukmini, H. S.

    2018-01-01

    Kecombrang flower (Nicolaia speciosa) contains bioactive components of alkaloids, flavonoids, polyphenols, steroids, saponins, and essential oils as potential antimicrobials. The use of antibacterials in the form of essential oils has constraints; therefore microencapsulation needs to be done to prevent damage to the bioactive components. Microencapsulation can prevent degradation due to radiation or oxygen, easy-mix with foodstuffs and also slow the occurrence of evaporation. This study aimed to determine the effect of types of kecombrang extract, the concentration of microcapsules in food additives (NaCl and sucrose), and concentration of flower extract in the microcapsules. This study used Randomized Block Design (RBD) with 18 treatment combinations and two replications. Factors studied were types of kecombrang flower extract of (semi polar and polar extract), Food Additive types (sucrose and NaCl), the concentration of microcapsules in food additive (0%; 15%; 30% w /v). The results showed that polar and non-polar extract microcapsules produced antibacterial activity of 7.178 mm and 7.145 respectively of Bacillus cereus bacteria, while Escherichia coli was 7.272 mm and 7.289 mm respectively. A 30 percent microcapsule concentration provides antibacterial activity with inhibiting zone of 7, 818 mm for B. cereus and 8,045 for E.coli. Food Additive of sucrose concentrations showed that microcapsules produced tend to be more effective in inhibiting the growth of E.coli and B. cereus bacteria than that of NaCl, with each inhibition zone of 7.499 mm and 7.357 mm

  18. Syzygium jambos Displayed Antibacterial and Antibiotic-Modulating Activities against Resistant Phenotypes

    Directory of Open Access Journals (Sweden)

    Brice E. N. Wamba

    2018-01-01

    Full Text Available The present study was designed to evaluate the antibacterial activities of methanol extracts of bark and leaves of Syzygium jambos, as well as their synergistic effects with selected antibiotics against drug-resistant Gram-positive and Gram-negative bacteria. The crude extracts were subjected to qualitative phytochemical screening; broth microdilution method was used for antibacterial assays. Phytochemical studies indicate that leaves and bark extracts contained polyphenols, anthraquinones, tannins, and steroids. Extract of the leaves was active against all the 26 strains of Staphylococcus aureus and all the 21 strains of Gram-negative bacteria tested, within the minimum inhibitory concentration (MIC range of 32–512 μg/mL. The lowest MIC value of 32 μg/mL was obtained with extract of the leaves against Staphylococcus aureus MRSA9 strain. In Gram-negative bacteria, the lowest MIC value of 64 μg/mL was also obtained against Enterobacter aerogenes EA294 and Klebsiella pneumoniae K24 strains. Against S. aureus strains, antibiotic-modulating activity of extracts at MIC/2 towards more than 70% of the tested strains was obtained when leaves and bark extracts were tested in association with chloramphenicol (CHL. This was also the case when leaves extract was combined with CHL, kanamycin (KAN, tetracycline (TET, and erythromycin (ERY and when bark extract was combined with ciprofloxacin (CIP, TET, and ERY against Gram-negative bacteria. In conclusion, this study demonstrated that Syzygium jambos has antibacterial and antibiotic-modulating activities.

  19. Protoporphyrin-IX conjugated cellulose nanofibers that exhibit high antibacterial photodynamic inactivation efficacy

    Science.gov (United States)

    Dong, Jiancheng; Ghiladi, Reza A.; Wang, Qingqing; Cai, Yibing; Wei, Qufu

    2018-06-01

    Towards the development of anti-infective nanoscale materials employing a photodynamic mechanism of action, we report the synthesis, physical properties (SEM, mechanical strength, water contact angle), spectroscopic characterization (infrared, Raman, DRUV), and evaluation of antibacterial efficacy of porphyrin-conjugated regenerated cellulose nanofibers, termed RC-TETA-PPIX-Zn. Cellulose acetate was electrospun to produce nanofibers, thermally treated to enhance mechanical strength, and finally hydrolyzed to produce regenerated cellulose (RC) nanofibers that possessed a high surface area and nanofibrous structure. Covalent grafting of a protoporphyrin IX (PPIX) photosensitizer using epichlorohydrin/triethylenetetramine (TETA), followed by zinc chelation, afforded RC-TETA-PPIX-Zn. The high surface area afforded by the nanofibers and efficient photosensitizer conjugation led to a very high loading of 412 nmol PPIX/mg material, corresponding to a degree of substitution of 0.1. Antibacterial efficacy was evaluated against Staphylococcus aureus (ATCC-6538) and Escherichia coli (ATCC-8099), with our best results achieving detection limit inactivation (99.999+%) of both bacteria after only 20 min illumination (Xe lamp, λ ≥ 420 nm). No statistically significant loss in antibacterial activity was observed when using nanofibers that had been ‘photo-aged’ with 5 h of pre-illumination to simulate the effects of photobleaching. Post aPDI, scanning electron microscopy revealed that the bacteria had undergone cell membrane leakage, consistent with oxidative damage caused by photo-generated reactive oxygen species. Taken together, the conjugation strategy employed here provides a scalable, facile and efficient route to creating nanofibrous materials from natural polymers with a high photosensitizer loading, enabling the use of commercially-available neutral porphyrin photosensitizers, such as PPIX, in the design and synthesis of potent anti-infective nanomaterials.

  20. Comparison of the antibacterial activity and synergistic activity towards antibiotics of different mammalian sera.

    Science.gov (United States)

    Miglioli, P A; Pea, F; Mazzo, M; Berti, T

    1993-02-01

    The antibacterial activity against Escherichia coli ATCC 10798 and Staphylococcus aureus Mag 90 of normal sera from nine species of mammals was investigated by Avantage (Abbott). Human and rat sera showed the highest antibacterial activity against E. coli ATCC 10798, while all investigated sera did not exhibit, till the maximum concentration tested (20%), spontaneous antibacterial activity against S. aureus Mag 90. Heat inactivated sera (56 degrees C for 30 min) of all investigated species lost their antibacterial activity, but maintained their synergistic effect with sub-MICs of some antibacterial drugs, principally against E. coli ATCC 10798.

  1. Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Yerly Vargas Casanova

    2017-09-01

    Full Text Available Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922 and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.

  2. Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines.

    Science.gov (United States)

    Vargas Casanova, Yerly; Rodríguez Guerra, Jorge Antonio; Umaña Pérez, Yadi Adriana; Leal Castro, Aura Lucía; Almanzar Reina, Giovanni; García Castañeda, Javier Eduardo; Rivera Monroy, Zuly Jenny

    2017-09-29

    Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922) and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.

  3. In Silico Characterization of the Binding Affinity of Dendrimers to Penicillin-Binding Proteins (PBPs): Can PBPs be Potential Targets for Antibacterial Dendrimers?

    Science.gov (United States)

    Ahmed, Shaimaa; Vepuri, Suresh B; Ramesh, Muthusamy; Kalhapure, Rahul; Suleman, Nadia; Govender, Thirumala

    2016-04-01

    We have shown that novel silver salts of poly (propyl ether) imine (PETIM) dendron and dendrimers developed in our group exhibit preferential antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus. This led us to examine whether molecular modeling methods could be used to identify the key structural design principles for a bioactive lead molecule, explore the mechanism of binding with biological targets, and explain their preferential antibacterial activity. The current article reports the conformational landscape as well as mechanism of binding of generation 1 PETIM dendron and dendrimers to penicillin-binding proteins (PBPs) in order to understand the antibacterial activity profiles of their silver salts. Molecular dynamics at different simulation protocols and conformational analysis were performed to elaborate on the conformational features of the studied dendrimers, as well as to create the initial structure for further binding studies. The results showed that for all compounds, there were no significant conformational changes due to variation in simulation conditions. Molecular docking calculations were performed to investigate the binding theme between the studied dendrimers and PBPs. Interestingly, in significant accordance with the experimental data, dendron and dendrimer with aliphatic cores were found to show higher activity against S. aureus than the dendrimer with an aromatic core. The latter showed higher activity against MRSA. The findings from this computational and molecular modeling report together with the experimental results serve as a road map toward designing more potent antibacterial dendrimers against resistant bacterial strains.

  4. [The history of the development and changes of quinolone antibacterial agents].

    Science.gov (United States)

    Takahashi, Hisashi; Hayakawa, Isao; Akimoto, Takeshi

    2003-01-01

    The quinolones, especially the new quinolones (the 6-fluoroquinolones), are the synthetic antibacterial agents to rival the Beta-lactam and the macrolide antibacterials for impact in clinical usage in the antibacterial therapeutic field. They have a broad antibacterial spectrum of activity against Gram-positive, Gram-negative and mycobacterial pathogens as well as anaerobes. Further, they show good-to-moderate oral absorption and tissue penetration with favorable pharmacokinetics in humans resulting in high clinical efficacy in the treatment of many kinds of infections. They also exhibit excellent safety profiles as well as those of oral Beta-lactam antibiotics. The bacterial effects of quinolones inhibit the function of bacterial DNA gyrase and topoisomerase IV. The history of the development of the quinolones originated from nalidixic acid (NA), developed in 1962. In addition, the breakthrough in the drug design for the scaffold and the basic side chains have allowed improvements to be made to the first new quinolone, norfloxacin (NFLX), patented in 1978. Although currently more than 10,000 compounds have been already synthesized in the world, only two percent of them were developed and tested in clinical studies. Furthermore, out of all these compounds, only twenty have been successfully launched into the market. In this paper, the history of the development and changes of the quinolones are described from the first quinolone, NA, via, the first new quinolone (6-fluorinated quinolone) NFLX, to the latest extended-spectrum quinolone antibacterial agents against multi-drug resistant bacterial infections. NA has only modest activity against Gram-negative bacteria and low oral absorption, therefore a suitable candidate for treatment of systemic infections (UTIs) is required. Since the original discovery of NA, a series of quinolones, which are referred to as the old quinolones, have been developed leading to the first new quinolone, NFLX, with moderate improvements

  5. Recent advances in engineering topography mediated antibacterial surfaces

    Science.gov (United States)

    Hasan, Jafar; Chatterjee, Kaushik

    2015-09-01

    The tendency of bacterial cells to adhere and colonize a material surface leading to biofilm formation is a fundamental challenge underlying many different applications including microbial infections associated with biomedical devices and products. Although, bacterial attachment to surfaces has been extensively studied in the past, the effect of surface topography on bacteria-material interactions has received little attention until more recently. We review the recent progress in surface topography based approaches for engineering antibacterial surfaces. Biomimicry of antibacterial surfaces in nature is a popular strategy. Whereas earlier endeavors in the field aimed at minimizing cell attachment, more recent efforts have focused on developing bactericidal surfaces. However, not all such topography mediated bactericidal surfaces are necessarily cytocompatible thus underscoring the need for continued efforts for research in this area for developing antibacterial and yet cytocompatible surfaces for use in implantable biomedical applications. This mini-review provides a brief overview of the current strategies and challenges in the emerging field of topography mediated antibacterial surfaces.

  6. In Vitro antibacterial activity of rumex nervosus, plantago lanceolata ...

    African Journals Online (AJOL)

    The finding indicated that Rumex nervosus showed have the highest zone of inhibition (20mm) against the genus Salmonella followed by Plantago lanceolata with the zone of inhibition (16mm) against L. monocytogenes. On the other hand, Lepidium sativum and Solanum incanum did not have any antibacterial activity ...

  7. Assessment of antibacterial activity of three plants used in Pakistan ...

    African Journals Online (AJOL)

    The in vitro antimicrobial activity of Justicia adhatoda, Glycyrrhiza glabra and Hyssopus officinalis extracts were studied against selected bacteria by using agar well diffusion assay. Methanol, ethanol, chloroform, diethyl-ether and aqueous extracts were tested in crude form for antibacterial activity against Bacillus subtillus, ...

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

    African Journals Online (AJOL)

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

  9. Evaluation of the antibacterial spectrum of drosocin analogues

    NARCIS (Netherlands)

    Bikker, F.J.; Kaman-van Zanten, W.E.; Vries-van de Ruit, A.M.B.C. de; Voskamp-Visser, I.; Hooft, P.A.V. van; Mars-Groenendijk, R.H.; Visser, P.C. de; Noort, D.

    2006-01-01

    Drosocin is a 19-mer, cationic antimicrobial peptide from Drosophila melanogaster. The aim of the study was to examine the antibacterial spectrum of unglycosylated drosocin analogues. Furthermore, the amino acid sequence of DnaK, drosocin's intracellular target, from susceptible species was aligned

  10. Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

    Directory of Open Access Journals (Sweden)

    Mehnaz Pervin

    2013-12-01

    Full Text Available Objective: To investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum . Methods: Free radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenolic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx, metal chelating activity, reduction power, lipid peroxidation inhibition and the prevention of oxidative DNA damage. Antibacterial activity was determined by using disc diffusion method against seven strains of bacteria. Results: Results found that V. corymbosum leaf extract had significant antibacterial activity. The tested extract displayed the highest activity (about 23.18 mm inhibition zone against Salmonella typhymurium and the lowest antibacterial activity was observed against Enterococcus faecalis (about 14.08 mm inhibition zone at 10 mg/ disc. The IC 50 values for DPPH, ABTS and radical scavenging activity were 0.120, 0.049 and 1.160 mg/mL, respectively. V. corymbosum leaf extract also showed dose dependent reduction power, lipid peroxidation, DNA damage prevention and significant antioxidant enzymatic activity. Conclusions: These findings demonstrate that leaf extract of V. corymbosum could be used as an alternative therapy for antibiotic-resistant bacteria and help prevent various free radical related diseases.

  11. Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

    Science.gov (United States)

    Pervin, Mehnaz; Hasnat, Md Abul; Lim, Beong Ou

    2013-01-01

    Objective To investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum). Methods Free radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenoic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx), metal chelating activity, reduction power, lipid peroxidation inhibition and the prevention of oxidative DNA damage. Antibacterial activity was determined by using disc diffusion for seven strains of bacteria. Results Results found that V. corymbosum leaf extract had significant antibacterial activity. The tested extract displayed the highest activity (about 23.18 mm inhibition zone) against Salmonella typhymurium and the lowest antibacterial activity was observed against Enterococcus faecalis (about 14.08 mm inhibition zone) at 10 mg/ disc. The IC50 values for DPPH, ABTS and radical scavenging activity were 0.120, 0.049 and 1.160 mg/mL, respectively. V. corymbosum leaf extract also showed dose dependent reduction power, lipid peroxidation, DNA damage prevention and significant antioxidant enzymatic activity. Conclusions These findings demonstrate that leaf extract of V. corymbosum could be used as an alternative therapy for antibiotic-resistant bacteria and help prevent various free radical related diseases.

  12. Antibacterial, antioxidant and cytotoxic activities of extracts from the ...

    African Journals Online (AJOL)

    Unicellular green algal strains, identified as Cosmarium (Chlorophyta), were isolated from Ain-Echeffa hot spring in north Tunisia. Different extracts (methanol, hexane, acetone, acetone: methanol and water) obtained from both biomass and extracellular polysaccharides (EPS) were evaluated for their antibacterial, ...

  13. Antibacterial activity of Eucalpytus citriodora Hk. oil on few clinically ...

    African Journals Online (AJOL)

    SERVER

    2008-01-04

    Jan 4, 2008 ... The antibacterial activity of Eucalyptus citriodora oil was evaluated. The volatile oil was extracted by steam distillation method. The tested bacterial strains were Escherichia coli ATCC 25922,. Staphylococcus aureus, Proteus mirabilis NCIM2241, Pseudomonas aeruginosa ATCC27853, Proteus vulgaris ...

  14. Antioxidant, Antibacterial and Cell Toxicity Effects of Polyphenols

    African Journals Online (AJOL)

    Z. Ghouila, S. Laurent, S. Boutry, L. Vander Elst, F. Nateche, R. N. Muller, A. Baaliouamer

    2017-01-01

    Jan 1, 2017 ... At 100 μg/mL, GSE induced a moderate toxicity of the order of ... the many phytochemical compounds consumed in our diet, polyphenols are the most ... action of grape seed extract in many health related areas due to its antioxidant effect [11]. In ...... antibacterial activities of southern Serbian red wines.

  15. Phytochemical Screening and Antibacterial Activity of Cucurbita pepo

    African Journals Online (AJOL)

    Phytochemical screening and antibacterial activity of the extracts of Cucurbita pepo (backpeel and seeds) against Staphylococcus aureus and Salmonella typhi were carried out using standard procedures. The extraction was achieved using percolation method with ethanol and methanol as solvents. Higher yield of the ...

  16. Evaluation of anti-leishmanial and antibacterial activity of ...

    African Journals Online (AJOL)

    Purpose: To evaluate the anti-leishmanial and antibacterial activities of a relatively unexplored whole plant of Waldheimia tomentosa (Asteraceae) and the chemical profiling of its most bioactive fraction. Methods: The whole plant material was extracted with methanol - water (9 : 1) and fractionated into nhexane (C6H14 or ...

  17. Antifungal and antibacterial activities of an alcoholic extract of ...

    African Journals Online (AJOL)

    Methanolic, ethanolic and petroleum ether extracts of Senna alata leaves were screened for phytochemicals, antibacterial and antifungal activities. Out of the three crude extracts, the methanolic extract showed the highest activity than the ethanolic and petroleum ether extracts. The unidentified active components purified ...

  18. Antibacterial activity of soaps against daily encountered bacteria ...

    African Journals Online (AJOL)

    This study aims to check the antibacterial activity of various branded soaps against bacteria that are normally present in the environment. The proposed study includes selection of most common bacterial strains from the environment. Identification of bacterial strains was done by standard microbiological techniques, which ...

  19. Antibacterial activity of watermelon ( Citrullus lanatus ) seed against ...

    African Journals Online (AJOL)

    This study was aimed at evaluating the effect of extraction methods on the antibacterial activity of Citrullus lanatus seed extract. C. lanatus (watermelon) is a popular fruit consumed all over the world. Three solvents were used for the extraction process: chloroform, methanol and distilled water while two extraction conditions- ...

  20. Isolation and Characterization of Antibacterial Compounds from Sea Urchin

    Directory of Open Access Journals (Sweden)

    Febrina Olivia Akerina,

    2015-06-01

    Full Text Available method, toxicity potential using brine shrimp lethality test (BSLT method, bioactive compound using phytochemical method, and proximate composition by AOAC. This research was devided into two phases, the preliminary research was to determine the best body part of sea urchin showing antibacterial activity. Sea urchins were collected from Pramuka Island and extracted by meseration method. For the preliminary research, gonad extract showed the high antibacterial activity against E. coli and S. aureus at 1.83 ± 0.74 mm and 1.5 mm, respectively. The main research includes the determination of proximate composition, toxicity, bioactive compound, and antibacterial activity from the best body part of sea urchin. The proximate composition from gonad of sea urchin showed that water content 64.97 ± 0.08%; ash 2.72 ± 0.13%; lipid 19.73 ± 0.04%; protein 12.26 ± 0.3%, and 0.33 ± 0.17%, respectively. The detected bioactive compounds from the three different solvents of gonads extracts were steroid, triterpenoid and saponin. The result of lethal toxicity (LC50 from the three gonads extract was 471.861 ppm (n-hexane, 563.226 ppm (ethyl acetate and 577.531 ppm (methanolic, respectively. Gonads ethyl acetate extracts showed the highest antibacterial activity than n-hexane and methanolic extract, its inhibition zone was 2.71 mm against S. aureus and 4.13 against E. coli.

  1. Targeted Drug-Carrying Bacteriophages as Antibacterial Nanomedicines▿

    Science.gov (United States)

    Yacoby, Iftach; Bar, Hagit; Benhar, Itai

    2007-01-01

    While the resistance of bacteria to traditional antibiotics is a major public health concern, the use of extremely potent antibacterial agents is limited by their lack of selectivity. As in cancer therapy, antibacterial targeted therapy could provide an opportunity to reintroduce toxic substances to the antibacterial arsenal. A desirable targeted antibacterial agent should combine binding specificity, a large drug payload per binding event, and a programmed drug release mechanism. Recently, we presented a novel application of filamentous bacteriophages as targeted drug carriers that could partially inhibit the growth of Staphylococcus aureus bacteria. This partial success was due to limitations of drug-loading capacity that resulted from the hydrophobicity of the drug. Here we present a novel drug conjugation chemistry which is based on connecting hydrophobic drugs to the phage via aminoglycoside antibiotics that serve as solubility-enhancing branched linkers. This new formulation allowed a significantly larger drug-carrying capacity of the phages, resulting in a drastic improvement in their performance as targeted drug-carrying nanoparticles. As an example for a potential systemic use for potent agents that are limited for topical use, we present antibody-targeted phage nanoparticles that carry a large payload of the hemolytic antibiotic chloramphenicol connected through the aminoglycoside neomycin. We demonstrate complete growth inhibition toward the pathogens Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli with an improvement in potency by a factor of ∼20,000 compared to the free drug. PMID:17404004

  2. Magnesium Oxide Nanoparticles: Effective Agricultural Antibacterial Agent Against Ralstonia solanacearum

    Directory of Open Access Journals (Sweden)

    Lin Cai

    2018-04-01

    Full Text Available Magnesium (Mg is an essential mineral element for plants and is nontoxic to organisms. In this study, we took advantage of nanotechnologies to systematically investigate the antibacterial mechanisms of magnesium oxide nanoparticles (MgONPs against the phytopathogen Ralstonia solanacearum (R. solanacearum in vitro and in vivo for the first time. R. solanacearum has contributed to catastrophic bacterial wilt, which has resulted in the world-wide reduction of tobacco production. The results demonstrated that MgONPs possessed statistically significant concentration-dependent antibacterial activity, and the minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were measured as 200 and 250 μg/mL, respectively. Additional studies, aimed at understanding the toxicity mechanism of MgONPs, indicated that physical injury occurred to the cell membranes, along with decreased motility and biofilm formation ability of R. solanacearum, due to the direct attachment of MgONPs to the surfaces of the bacterial cells, which was observed by scanning electron microscopy (SEM and transmission electron microscopy (TEM. Reactive oxygen species (ROS accumulation could also be an important reason for the antibacterial action, inducing DNA damage. The toxicity assessment assay under greenhouse conditions demonstrated that the MgONPs had exerted a large effect on tobacco bacterial wilt, reducing the bacterial wilt index. Altogether, the results suggest that the development of MgONPs as alternative antibacterial agents will become a new research subject.

  3. In vitro antibacterial activity of crude methanol extracts of various ...

    African Journals Online (AJOL)

    Parthenium hysterophorus is an aggressive and exotic weed plant traditionally reported to be used as remedy for various diseases. In the present study in vitro antibacterial activities of P. hysterophorus leaf, flower, bark and root crude methanol extracts were evaluated against five reference strains of pathogenic bacterial ...

  4. Antibacterial activity of Sargassum polycystum C. Agardh and ...

    African Journals Online (AJOL)

    In this study, the antibacterial activity of n-hexane, dichloromethane and methanolic extracts of brown seaweeds (Phaeophyceae), Sargassum polycystum C. Agardh and Padina australis Hauck, was examined using the disc diffusion and broth microdilution methods. The bioactivity of the seaweed extracts was expressed as ...

  5. In vitro antibacterial activity of some plant essential oils

    Directory of Open Access Journals (Sweden)

    Ignacimuthu Savarimuthu

    2006-11-01

    Full Text Available Abstract Background: To evaluate the antibacterial activity of 21 plant essential oils against six bacterial species. Methods: The selected essential oils were screened against four gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris and two gram-positive bacteria Bacillus subtilis and Staphylococcus aureus at four different concentrations (1:1, 1:5, 1:10 and 1:20 using disc diffusion method. The MIC of the active essential oils were tested using two fold agar dilution method at concentrations ranging from 0.2 to 25.6 mg/ml. Results: Out of 21 essential oils tested, 19 oils showed antibacterial activity against one or more strains. Cinnamon, clove, geranium, lemon, lime, orange and rosemary oils exhibited significant inhibitory effect. Cinnamon oil showed promising inhibitory activity even at low concentration, whereas aniseed, eucalyptus and camphor oils were least active against the tested bacteria. In general, B. subtilis was the most susceptible. On the other hand, K. pneumoniae exhibited low degree of sensitivity. Conclusion: Majority of the oils showed antibacterial activity against the tested strains. However Cinnamon, clove and lime oils were found to be inhibiting both gram-positive and gram-negative bacteria. Cinnamon oil can be a good source of antibacterial agents.

  6. phytochemical and antibacterial properties of garlic extracts 45

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The antibacterial potency of aqueous and methanol extracts of garlic was determined invitro against three bacterial isolates (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) by agar well diffusion method. Preliminary phytochemical screening revealed the presence of tannin, flavonoid, ...

  7. In-Vitro Antibacterial Activities And Preliminary Phytochemical ...

    African Journals Online (AJOL)

    Studies on the in-vitro antibacterial activities and phytochemical screening of the aqueous and ethanolic extracts of Zingiber officinale (ginger) against some clinical bacterial isolates (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) obtained from ear and urine samples were carried out using ...

  8. Phytochemical and Antibacterial Properties of Root and Leaf ...

    African Journals Online (AJOL)

    Antibacterial growth inhibition was determined using Ditch method against ... have examined the effects of plants used traditionally ... and 16 cm wide (Aliyu, 2006). .... India. Likewise, water extracts obtained from the root did not show activity on all the test organisms except .... toxicity studies of Parkinsonia aculeate L.

  9. Phytochemical study and antibacterial activity of different extracts of ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the phytochemical proprieties, antioxidant and antibacterial activities of different extracts of Pistacia lentiscus on two pathogenic bacteria. The concentration of total phenols was analyzed using Folin-Ciocalteu's method. Exracts of plant were evaluated for their antimicrobial ...

  10. Antibacterial activity of chrysophanol isolated from Aloe excelsa ...

    African Journals Online (AJOL)

    Extraction of the yellow colour compounds of leaves of Aloe excelsa were performed and 1,8-dihydroxy-3-methylanthracenedione (chrysophanol) was isolated and tested for antibacterial activities against four gram negative and five gram positive bacterial strains. The structures of chrysophanol was determined by chemical ...

  11. Antibacterial-guided isolation of constituents from Senna alata ...

    African Journals Online (AJOL)

    From these results obtained, S. alata leaf could be considered as a natural antibacterial source ... al., 2014; Ogwuche et al., 2015). To the best of our .... American Type Culture Collection (ATCC) strain, Staphylococcus aureus ATCC 25923, was used for quality ... values ranging from 64 to 1024 µg/ml (Table. 1), and were ...

  12. Antibacterial and antioxidant activities of the essential oils and ...

    African Journals Online (AJOL)

    The present study deals with the evaluation of the in vitro antioxidant and antibacterial activity of phenolic extracts and essential oils of two medicinal and aromatic plants Zygophyllum album and Myrtus communis by using the 2,2- diphenyl-2-picrylhydrazyl radical, total antioxidant power and agar diffusion methods and ...

  13. antibacterial activities of the volatile oil and aqueous extract of ...

    African Journals Online (AJOL)

    The volatile oil of Murraya keonigii was active against Staphylococcus epidemidis, S. aureus, and Streptococcus specie while the aqueous extract was not active. Key Words: Murraya koenigii, Rutaceae, antibacterial activity. Nig. J. Nat. Prod. And Med. Vol.2 1998: 44-45 ...

  14. Antibacterial activities of the crude ethanol extracts of medicinal ...

    African Journals Online (AJOL)

    Antibacterial activities of the crude ethanol extracts of medicinal plants against Listeria monocytogenes and some other pathogenic strains. ... The major components of extracts tested were identified by gas chromatography coupled with mass spectrometry (GC/MS) analysis. The obtained results revealed in vitro anti-Listeria ...

  15. Preliminary studies of the antibacterial activities of processed ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-06

    Oct 6, 2006 ... Toda M, Okubo S, Ikigai H, Suzuki T, Shimamura T (1991). The protective activity of the tea against infection by Vibrio cholerae J. Appl. Bacterial 70: 109 – 112. Toda M, Okubo S, Hiyoshi R, Shimamura T(1989) Antibacterial and bactericidal activities of Japanese green tea. Jpn. J. Bacteriol 44(4):. 669-672.

  16. In-vitro antibacterial activity of selected medicinal plants from ...

    African Journals Online (AJOL)

    Background: Current strategies to overcome the global problem of antimicrobial resistance include research in finding new and innovative antimicrobials from plants. This study was carried out to determine the antibacterial activity of plant extracts of Olea africana stem-bark, Psidium guajava leaves, Vernonia amygdalina ...

  17. Protein interactions in genome maintenance as novel antibacterial targets.

    Directory of Open Access Journals (Sweden)

    Aimee H Marceau

    Full Text Available Antibacterial compounds typically act by directly inhibiting essential bacterial enzyme activities. Although this general mechanism of action has fueled traditional antibiotic discovery efforts for decades, new antibiotic development has not kept pace with the emergence of drug resistant bacterial strains. These limitations have severely restricted the therapeutic tools available for treating bacterial infections. Here we test an alternative antibacterial lead-compound identification strategy in which essential protein-protein interactions are targeted rather than enzymatic activities. Bacterial single-stranded DNA-binding proteins (SSBs form conserved protein interaction "hubs" that are essential for recruiting many DNA replication, recombination, and repair proteins to SSB/DNA nucleoprotein substrates. Three small molecules that block SSB/protein interactions are shown to have antibacterial activity against diverse bacterial species. Consistent with a model in which the compounds target multiple SSB/protein interactions, treatment of Bacillus subtilis cultures with the compounds leads to rapid inhibition of DNA replication and recombination, and ultimately to cell death. The compounds also have unanticipated effects on protein synthesis that could be due to a previously unknown role for SSB/protein interactions in translation or to off-target effects. Our results highlight the potential of targeting protein-protein interactions, particularly those that mediate genome maintenance, as a powerful approach for identifying new antibacterial compounds.

  18. Cytotoxicity and antibacterial studies of iridoids and phenolic ...

    African Journals Online (AJOL)

    The latex of Himatanthus sucuuba (Spruce) Woodson, used popularly in the Amazon for the treatment of tumors, gastritis, inflammations and infections, was evaluated for cytotoxicity and antibacterial activities. The iridoid lactones, plumericin and isoplumericin were isolated from latex by bioassay fractionation and were ...

  19. Synthesis and antibacterial evaluation of some novel mannich ...

    African Journals Online (AJOL)

    Substituted benzimidazoles are known for their chemotherapeutic importance and many pharmacological properties. In this paper, we synthesized some novel Mannich bases of benzimidazole derivatives. The synthesized compounds were characterized by their physical and spectral data and in vitro antibacterial activity of ...

  20. Characterisation and Safety of Intraperitoneal Perioperative Administration of Antibacterial Agents

    DEFF Research Database (Denmark)

    Fonnes, Siv; Holzknecht, Barbara Juliane; Arpi, Magnus

    2017-01-01

    event was discomfort or pain during administration, especially with use of oxytetracycline. Conclusion At least 12 different classes of antibacterial agents have been administered intraperitoneally during or after surgery as prophylaxis or treatment of intraabdominal infections. Intraperitoneal...... administration seems safe although use of oxytetracycline may cause discomfort or pain....

  1. Antibacterial activity of papain hydrolysed camel whey and its fractions

    DEFF Research Database (Denmark)

    Abdel-Hamid, Mahmoud; Goda, Hanan A.; De Gobba, Cristian

    2016-01-01

    Camel whey (ON) was hydrolysed with papain from Carica papaya and fractionated by size exclusion chromatography (SEC). The antibacterial activity of the CW, camel whey hydrolysate (CWH) and the obtained SEC-fractions was assessed using the disc-diffusion method. The CWH exhibited significantly...

  2. Synthesis and antibacterial activity of sulfonamide derivatives at C-8 ...

    Indian Academy of Sciences (India)

    showed higher antibacterial activity compared with standard drug ampicillin. Keywords. Synthesis ... factor-kB regulated gene products leading to potenti- ation of ... constituent of CNSL natural source to evaluate their biological activity by ... Analytical thin layer ..... cially available CNSL by a reported method.26 Accord-.

  3. Antibacterial activity of essential oils: potential applications in food

    NARCIS (Netherlands)

    Burt, S.A.

    2007-01-01

    Due to its antibacterial activity, oregano oil has lately become interesting as a potential 'natural' food preservative. Oregano oil was found to be a fast acting and effective inhibitor of a strain of Escherichia coli O157:H7, the causative agent of a serious gastro-enteritis, and was lethal to

  4. Preliminary studies of the antibacterial activities of processed ...

    African Journals Online (AJOL)

    The antibacterial activities of extracts in Kenyan and Nigerian tea bags were tested for activity against six organisms; Pseudomonas aeruginosa, Staphylococcus aureus, Vibrio cholerea, Salmonella sp., Proteus sp. and Escherichia coli using the agar-gel diffusion method. The result obtained showed that 20% extract of both ...

  5. Comparative Study of Antibacterial Activities of the Fresh and Dried ...

    African Journals Online (AJOL)

    The fresh and dried fruit extracts of Capsicum species were screened for antibacterial activities against Staph. aureus, S. typhi and B. subtilis using two assay methods. The filter disk and agar plate diffusion were the assay methods employed in the study. The results of the study revealed that the extracts obtained from the ...

  6. Evaluation of the antibacterial activity of Syzygium cordatum fruit ...

    African Journals Online (AJOL)

    This study aimed at evaluating the antibacterial activity of S. cordatum fruits and seeds against bacteria causing GIT infections. The harvested fruits were separated into fruit-pulp and seeds, dried and extracted with methanol using Soxhlet extraction. The extracts were phytochemically screened and micro dilution assay was ...

  7. Selective antibacterial effects of mixed ZnMgO nanoparticles

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  8. Phytochemicals, antioxidant and antibacterial properties of a lichen ...

    African Journals Online (AJOL)

    Antioxidant activity assessment was performed using the free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and reducing power assay. Phytochemical screening was done using chemical tests. Antibacterial activities of Cladonia digitata were determined by a disk diffusion method at ...

  9. Antibacterial and Anti-Inflammatory Activities of Anacardium ...

    African Journals Online (AJOL)

    ABSTRACT: Anacardium occidentale is a local medicinal plant used in ethno medicine for the treatment of diarrhea, constipation,pain and inflammation. The aqueous and ethanolic extracts of this plant parts were assessed for anti- inflammatory and antibacterial activities using experimental animal model and agar disc ...

  10. The antibacterial activity of Clausena anisata hook, a South African ...

    African Journals Online (AJOL)

    African Journal of Traditional, Complementary and Alternative Medicines ... Background: Clausena anisata Hook also known as Iperepesi in Xhosa language is a medicinal plant used traditionally for the treatment of various ailments and ... Key words: Clausena anisata; tuberculosis; antibacterial activity; herbal medicine.

  11. Antibacterial activity of honey and medicinal plant extracts against ...

    African Journals Online (AJOL)

    Using a broth dilution method, the antibacterial activity extracts of six South African honeys and medicinal plants against six enteric microorganisms viz- Enterobacter cloacae, Escheriachia coli, Klebsiella pneumoniae, Citrobacter freundii isolated from geophagia samples and Aeromonas hydrophila and plesiomonas ...

  12. Prospects for new antibacterials: can we do better?

    Science.gov (United States)

    Georgopapadakou, Nafsika H

    2014-02-01

    Bacterial resistance to antibacterial drugs has been increasing relentlessly over the past two decades. This includes common residents of the human body: Staphylococcus aureus (methicillin resistant or MRSA) Enteroccus faecalis and E. faecium (vancomycin resistant or VRE): Enterobacteriaceae (multiresistant, carbapenems included or CRE). It also includes environmental, opportunistic, but intrinsically multiresistant species: Pseudomonas aeruginosa and Acinetobacter baumannii. Financial considerations have curtailed R&D activity in the antibacterial field in all, but a couple of large pharmaceutical companies and small biotech companies have largely been unable to fill the drug discovery gap. Antibacterials currently under development have targeted, almost exclusively, Gram-positive bacteria; hence, greater effort must be directed against Gram-negative bacteria, particularly enterobacteria. There also has to be more transparency and care in clinical development. To get ahead of the problem of resistance, we must look for first-in-class antibacterials and new targets. The need to innovate is best addressed through partnerships between drug-makers and public institutions. Such partnerships would provide a long-term view and stability to projects, but also balance the interests of corporate and public stakeholders.

  13. Specific gravity and antibacterial assays of some synthetic industrial ...

    African Journals Online (AJOL)

    ... naturalcounterpart may contain certain antibacterial agents with similar effects to standard Chloramphenicol used in this work. However, further studies are required to justify the safety of the application of SIEO as antimicrobial agents. Keywords: synthetic fragrance, Staphylococcus aureus, Escherichia coli, human health ...

  14. Antibacterial activity of whole plant extract of Marrubium vulgare

    African Journals Online (AJOL)

    SERVER

    2007-11-26

    Nov 26, 2007 ... Key words: Disc diffusion, antibacterial activity, Marrubium vulgare. INTRODUCTION .... Glossary of Indian Medicinal. Plants, CSIR, V ed. ... 22. E. coli MTCC 443. 0. 0. 0. 10. 15. 400. 25. P. vulgaris MTCC 426. 0. 0. 0. 11. 16.

  15. In vitro Antibacterial Activity of Alchornea cordifolia Bark Extract ...

    African Journals Online (AJOL)

    Four extracts of Alchornea cordifolia (Schumach.) Müll. Arg. (Euphorbiaceae) bark, including aqueous, methanol, acetone and hexane extracts, were tested for their antibacterial activities against Salmonella typhi, Salmonella paratyphi A and Salmonella paratyphi B, using both agar diffusion and broth dilution methods.

  16. Antibacterial activity of oxytetracycline photoproducts in marine aquaculture's water.

    Science.gov (United States)

    Leal, J F; Henriques, I S; Correia, A; Santos, E B H; Esteves, V I

    2017-01-01

    Oxytetracycline (OTC) is one of the most used antibiotics in aquaculture. The main concern related to its use is the bacterial resistance, when ineffective treatments are applied for its removal or inactivation. OTC photo-degradation has been suggested as an efficient complementary process to conventional methods used in intensive fish production (e.g.: ozonation). Despite this, and knowing that the complete mineralization of OTC is difficult, few studies have examined the antibacterial activity of OTC photoproducts. Thus, the main aim of this work is to assess whether the OTC photoproducts retain the antibacterial activity of its parent compound (OTC) after its irradiation, using simulated sunlight. For that, three Gram-negative bacteria (Escherichia coli, Vibrio sp. and Aeromonas sp.) and different synthetic and natural aqueous matrices (phosphate buffered solutions at different salinities, 0 and 21‰, and three different samples from marine aquaculture industries) were tested. The microbiological assays were made using the well-diffusion method before and after OTC has been exposed to sunlight. The results revealed a clear effect of simulated sunlight, resulting on the decrease or elimination of the antibacterial activity for all strains and in all aqueous matrices due to OTC photo-degradation. For E. coli, it was also observed that the antibacterial activity of OTC is lower in the presence of sea-salts, as demonstrated by comparison of halos in aqueous matrices containing or not sea-salts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Selective antibacterial effects of mixed ZnMgO nanoparticles

    Science.gov (United States)

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

    2013-05-01

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

  18. Selective antibacterial effects of mixed ZnMgO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-15

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

  19. Synthesis, antiproliferative and antibacterial activity of new amides of salinomycin.

    Science.gov (United States)

    Antoszczak, Michał; Maj, Ewa; Stefańska, Joanna; Wietrzyk, Joanna; Janczak, Jan; Brzezinski, Bogumil; Huczyński, Adam

    2014-04-01

    A series of 11 novel amides of salinomycin were synthesized for the first time. All the obtained compounds were found to show potent antiproliferative activity against human cancer cell lines including the drug-resistant cancer cells. Four new salinomycin derivatives revealed good antibacterial activity against clinical isolates of methicillin-resistant Staphylococcus epidermidis (MRSE). Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Comparative Costs of Antibacterial Usage in Sexually Transmitted ...

    African Journals Online (AJOL)

    Erah

    Purpose: To evaluate the cost of antibacterial usage to patients in a tertiary health facility in Nigeria. Methods: Drug utilization evaluation was carried out retrospectively among patients with sexually transmitted infections (STIs) over a one-year period between 2005 and 2006 in Lagos University. Teaching Hospital (LUTH) ...

  1. Antibacterial and Cytotoxic Activity of Compounds Isolated from Flourensia oolepis

    Directory of Open Access Journals (Sweden)

    Mariana Belén Joray

    2015-01-01

    Full Text Available The antibacterial and cytotoxic effects of metabolites isolated from an antibacterial extract of Flourensia oolepis were evaluated. Bioguided fractionation led to five flavonoids, identified as 2′,4′-dihydroxychalcone (1, isoliquiritigenin (2, pinocembrin (3, 7-hydroxyflavanone (4, and 7,4′-dihydroxy-3′-methoxyflavanone (5. Compound 1 showed the highest antibacterial effect, with minimum inhibitory concentration (MIC values ranging from 31 to 62 and 62 to 250 μg/mL, against Gram-positive and Gram-negative bacteria, respectively. On further assays, the cytotoxic effect of compounds 1–5 was determined by MTT assay on acute lymphoblastic leukemia (ALL and chronic myeloid leukemia (CML cell lines including their multidrug resistant (MDR phenotypes. Compound 1 induced a remarkable cytotoxic activity toward ALL cells (IC50 = 6.6–9.9 μM and a lower effect against CML cells (IC50 = 27.5–30.0 μM. Flow cytometry was used to analyze cell cycle distribution and cell death by PI-labeled cells and by Annexin V/PI staining, respectively. Upon treatment, 1 induced cell cycle arrest in the G2/M phase accompanied by a strong induction of apoptosis. These results describe for the first time the antibacterial metabolites of F. oolepis extract, with 1 being the most effective. This chalcone also emerges as a selective cytotoxic agent against sensitive and resistant leukemic cells, highlighting its potential as a lead compound.

  2. Antibacterial profile of fermented seed extracts of ricinus communis ...

    African Journals Online (AJOL)

    The study was carried out to ascertain the antibacterial properties inherent in fermented seed extracts of Ricinus communis. Dry seeds of R. communis (Castor oil plant) were deshelled, grounded to powder, fermented, and then extracted both with alcohol and water using Soxhlet machine. Different concentrations of the ...

  3. Quantification and antibacterial activity of flavonoids in coffee samples

    African Journals Online (AJOL)

    Background: Flavonoids are the phenolic substances widely found in fruits, vegetables, grains, bark, roots, stems, flowers, tea and coffee. Methodology: In the current study quantity of flavonoids and antibacterial activities were determined in different coffee samples namely Nescafe classic, Nescafe gold, Nescafe martina, ...

  4. antibacterial and antioxidant activities of the essential oils

    African Journals Online (AJOL)

    Belmimoun A, Meddah B, Meddah A.T.T and Sonnet P

    2016-05-01

    May 1, 2016 ... been used historically in the pharmaceutical, food and perfume industries because of their antibacterial properties, culinary and fragrance, respectively. Antioxidants have been widely used as additives to avoid the degradation of foods. Also, are compounds that react with free radicals, neualizing them and ...

  5. Antibacterial activities and toxicological potentials of crude ethanolic ...

    African Journals Online (AJOL)

    Leaves of Euphorbia hirta used in traditional medicine for the treatments of boils, wounds and control of diarrhoea and dysentery were extracted by maceration in ethanol. The agar diffusion method was used to determine the antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, ...

  6. Antibacterial hemostatic dressings with nanoporous bioglass containing silver

    Directory of Open Access Journals (Sweden)

    Hu G

    2012-05-01

    Full Text Available Gangfeng Hu,1 Luwei Xiao,2 Peijian Tong,2 Dawei Bi,1 Hui Wang,1 Haitao Ma,1 Gang Zhu,1 Hui Liu21The First People’s Hospital of Xiaoshan, Hangzhou, China; 2Zhejiang Traditional Chinese Medical University, Hangzhou, ChinaAbstract: Nanoporous bioglass containing silver (n-BGS was fabricated using the sol-gel method, with cetyltrimethyl ammonium bromide as template. The results showed that n-BGS with nanoporous structure had a surface area of 467 m2/g and a pore size of around 6 nm, and exhibited a significantly higher water absorption rate compared with BGS without nanopores. The n-BGS containing small amounts of silver (Ag had a slight effect on its surface area. The n-BGS containing 0.02 wt% Ag, without cytotoxicity, had a good antibacterial effect on Escherichia coli, and its antibacterial rate reached 99% in 12 hours. The n-BGS’s clotting ability significantly decreased prothrombin time (PT and activated partial thromboplastin time (APTT, indicating n-BGS with a higher surface area could significantly promote blood clotting (by decreasing clotting time compared with BGS without nanopores. Effective hemostasis was achieved in skin injury models, and bleeding time was reduced. It is suggested that n-BGS could be a good dressing, with antibacterial and hemostatic properties, which might shorten wound bleeding time and control hemorrhage.Keywords: antibacterial, bioglass, cytotoxicity, dressing, hemostasis, nanopore, silver

  7. In vitro antibacterial activity of Anogeissus leiocarpus leaf extracts on ...

    African Journals Online (AJOL)

    In vitro antibacterial activity of aqueous and ethanol extracts of the leaf of Anogeissus leiocarpus was tested on some bacteria associated with diarrhea which included Escherichia coli,Salmonella typhi,Salmonella typhimurium, Klebsiella aerogens and Yersinia enterocolitica using agar well diffusion method. There was ...

  8. Antioxidant, antibacterial activity, and phytochemical characterization of Melaleuca cajuputi extract.

    Science.gov (United States)

    Al-Abd, Nazeh M; Mohamed Nor, Zurainee; Mansor, Marzida; Azhar, Fadzly; Hasan, M S; Kassim, Mustafa

    2015-10-24

    The threat posed by drug-resistant pathogens has resulted in the increasing momentum in research and development for effective alternative medications. The antioxidant and antibacterial properties of phytochemical extracts makes them attractive alternative complementary medicines. Therefore, this study evaluated the phytochemical constituents of Melaleuca cajuputi flower and leaf (GF and GL, respectively) extracts and their antioxidant and antibacterial activities. Radical scavenging capacity of the extracts was estimated using 2,2-diphenyl-2-picrylhydrazyl and Fe(2+)-chelating activity. Total antioxidant activity was determined using ferric reducing antioxidant power assay. Well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration assays were used to determine antibacterial activity against eight pathogens, namely Staphylococcus aureus, Escherichia coli, Bacillus cereus, Staphylococcus epidermidis, Salmonella typhimurium, Klebsiella pneumonia, Streptococcus pneumoniae, and Pasteurella multocida. We identified and quantified the phytochemical constituents in methanol extracts using liquid chromatography/mass spectrometry (LC/MS) and gas chromatography (GC)/MS. This study reports the antioxidant and radical scavenging activity of M. cajuputi methanolic extracts. The GF extract showed better efficacy than that of the GL extract. The total phenolic contents were higher in the flower extract than they were in the leaf extract (0.55 ± 0.05 and 0.37 ± 0.05 gallic acid equivalent per mg extract dry weight, respectively). As expected, the percentage radical inhibition by GF was higher than that by the GL extract (81 and 75 %, respectively). A similar trend was observed in Fe(2+)-chelating activity and β-carotene bleaching tests. The antibacterial assay of the extracts revealed no inhibition zones with the Gram-negative bacteria tested. However, the extracts demonstrated activity against B. cereus, S. aureus, and S. epidermidis. In

  9. [Mutant prevention concentrations of antibacterial agents to ocular pathogenic bacteria].

    Science.gov (United States)

    Liang, Qing-Feng; Wang, Zhi-Qun; Li, Ran; Luo, Shi-Yun; Deng, Shi-Jing; Sun, Xu-Guang

    2009-01-01

    To establish a method to measure mutant prevention concentration (MPC) in vitro, and to measure MPC of antibacterial agents for ocular bacteria caused keratitis. It was an experimental study. Forty strains of ocular bacteria were separated from cornea in Beijing Institute of Ophthalmology, which included 8 strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa and Klebsiella pneumoniae respectively. The minimal inhibitory concentration (MIC) of the levofloxacin (LVF), ofloxacin (OFL), ciprofloxacin (CIP), norfloxacin (NFL), tobramycin (TOB) and chloromycetin (CHL) were determined by agar dilution method from National Committee of Clinical Laboratory Standard (NCCLS). The MPC were measured by accumulate-bacterial methods with bacterial population inoculated more than 1.2 x 10(10) colony forming units per milliliter with Mueller-Hinton broth and tryptic soy agar plate. With the software of SPSS 11.0, the datum such as the range of MIC, MPC, MIC90 and MPC90 were calculated, and the selection index (MPC90/ MI90) and mutant selection window (MSW) were obtained. The MI90 of LVF and TOB (4 mg/L) to Staphylococcus aureus strains were the lowest. CIP showed the lowest MIC90 (0.25 mg/L) to Pseudomonas aeruginosa among six kinds of antibacterial agents. The MIC90 of LVF to Staphylococcus epidermidis (256 mg/L), Streptococcus pneumoniae (1 mg/L) and Klebsiella pneumoniae (0.25 mg/L) were lower than other antibacterial agents. The MPC90, MSW and the MPC90/MIC90 of levofloxacin showed lower values compared with other antibacterial medicines. From all the datum, the MIC90 of CHL was the highest and the activity was the weakest. Although the activity of LVF was higher to every kind of bacteria, CIP had the highest activity antibacterial to Pseudomonas aeruginosa. The capacity of CHL and TOB was weaker than Quinolones for restricting resistant mutants on ocular bacteria. LVF had the strongest capacity for restricting resistant

  10. Novel Antibacterial Compounds and their Drug Targets - Successes and Challenges.

    Science.gov (United States)

    Kaczor, Agnieszka A; Polski, Andrzej; Sobótka-Polska, Karolina; Pachuta-Stec, Anna; Makarska-Bialokoz, Magdalena; Pitucha, Monika

    2017-01-01

    Infectious diseases are one of the most important and urgent health problems in the world. According to the World Health Organization (WHO) statistics, infectious and parasitic diseases are a cause of about 16% of all deaths worldwide and over 40% of deaths in Africa. A considerable progress that has been made during last hundred years in the fight against infectious diseases, in particular bacterial infections, can be attributed mainly to three factors: (1) the general improvement of living conditions, in particular sanitation; (2) development of vaccines and (3) development of efficient antibacterial drugs. Although considerable progress in reduction of the number of cases of bacterial infections, especially in lethal cases, has been made, continued cases and outbreaks of these diseases persist, which is caused by different contributing factors. Indeed, during last sixty years antibacterial drugs were used against various infectious diseases caused by bacterial pathogens with an undoubtable success. The most fruitful period for antibiotic development lasted from 40's to 60's of the last century and resulted in the majority of antibiotics currently on the market, which were obtained by screening actinomycetes derived from soil. Although the market for antibacterial drugs is nowadays greater than 25 billion US dollars per year, novel antibacterial drugs are still demanded due to developed resistance of many pathogenic bacteria against current antibiotics. In the last five years, one can observe a dramatic increase in cases of resistant bacteria strains (e.g. Klebsiella pneumoniae and E. coli) which are responsible for difficult to treat pneumonia and infections of urinary tract. The development of resistant bacteria strains is a side effect of antibiotic application for treatment: the infections become untreatable as a result of the existence of antibiotic-tolerant persisters. In this review, we discuss the challenges in antibacterial drug discovery, including the

  11. Antibacterial activities of medicinal plants used in Mexican traditional medicine.

    Science.gov (United States)

    Sharma, Ashutosh; Flores-Vallejo, Rosario Del Carmen; Cardoso-Taketa, Alexandre; Villarreal, María Luisa

    2017-08-17

    We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species. We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11

  12. Evaluation of the electron transfer flavoprotein as an antibacterial target in Burkholderia cenocepacia.

    Science.gov (United States)

    Stietz, Maria S; Lopez, Christina; Osifo, Osasumwen; Tolmasky, Marcelo E; Cardona, Silvia T

    2017-10-01

    There are hundreds of essential genes in multidrug-resistant bacterial genomes, but only a few of their products are exploited as antibacterial targets. An example is the electron transfer flavoprotein (ETF), which is required for growth and viability in Burkholderia cenocepacia. Here, we evaluated ETF as an antibiotic target for Burkholderia cepacia complex (Bcc). Depletion of the bacterial ETF during infection of Caenorhabditis elegans significantly extended survival of the nematodes, proving that ETF is essential for survival of B. cenocepacia in this host model. In spite of the arrest in respiration in ETF mutants, the inhibition of etf expression did not increase the formation of persister cells, when treated with high doses of ciprofloxacin or meropenem. To test if etf translation could be inhibited by RNA interference, antisense oligonucleotides that target the etfBA operon were synthesized. One antisense oligonucleotide was effective in inhibiting etfB translation in vitro but not in vivo, highlighting the challenge of reduced membrane permeability for the design of drugs against B. cenocepacia. This work contributes to the validation of ETF of B. cenocepacia as a target for antibacterial therapy and demonstrates the utility of a C. elegans liquid killing assay to validate gene essentiality in an in vivo infection model.

  13. Synthesis of Azole-containing Piperazine Derivatives and Evaluation of their Antibacterial, Antifungal and Cytotoxic Activities

    International Nuclear Information System (INIS)

    Gan, Lin Ling; Fang, Bo; Zhou, Cheng He

    2010-01-01

    A series of azole-containing piperazine derivatives have been designed and synthesized. The obtained compounds were investigated in vitro for their antibacterial, antifungal and cytotoxic activities. The preliminary results showed that most compounds exhibited moderate to significant antibacterial and antifungal activities in vitro. 1-(4-((4-chlorophenyl) (phenyl)methyl)piperazin-1-yl)-2-(1H-imidazol-1-yl)ethanone and 1-(4-((4-Chlorophenyl)(phenyl)methyl)piperazin-1- yl)-2-(2-phenyl-1H-imidazol-1-yl)ethanone gave remarkable and broad-spectrum antimicrobial efficacy against all tested strains with MIC values ranging from 3.1 to 25 μg/mL, and exhibited comparable activities to the standard drugs chloramphenicol and fluconazole in clinic. Moreover, 2-((4-((4-chlorophenyl)(phenyl)methyl)piperazin-1-yl)methyl)- 1H-benzo[d]imidazole was found to be the most effective in vitro against the PC-3 cell line, reaching growth inhibition values (36.4, 60.1 and 76.5%) for each tested concentration: 25 μM, 50 μM and 100 μM in dose-dependent manner. The results also showed that the azole ring had noticeable effect on their antimicrobial and cytotoxic activities, and imidazole and benzimidazole moiety were much more favourable to biological activity than 1,2,4-triazole

  14. Antibacterial Composite Layers on Ti: Role of ZnO Nanoparticles

    Directory of Open Access Journals (Sweden)

    Roguska A.

    2016-03-01

    Full Text Available Problem of Post-operative infections of implant materials caused by bacterial adhesion to their surfaces is very serious. Enhancement of antibacterial properties is potentially beneficial for biomaterials value. Therefore, the metallic and metallic oxide nanoparticles attract particular attention as antimicrobial factors. The aim of this work was to create nanotubular (NT oxide layers on Ti with the addition of ZnO nanoparticles, designed for antibacterial biomedical coatings. Antimicrobial activities of titanium, TiO2 NT and ZnO/TiO2 NT surfaces were evaluated against bacterial strain typical for orthopaedic infections: S. epidermidis. TiO2 NT alone killed the free bacterial cells significantly but promoted their adhesion to the surfaces. The presence of moderate amount of ZnO nanoparticles significantly reduced the S. epidermidis cells adhesion and viability of bacterial cells in contact with modified surfaces. However, higher amount of loaded nanoZnO showed the reduced antimicrobial properties than the medium amount, suggesting the overdose effect.

  15. Antitumor and Antibacterial Derivatives of Oridonin: A Main Composition of Dong-Ling-Cao

    Directory of Open Access Journals (Sweden)

    Dahong Li

    2016-04-01

    Full Text Available Isodon rubescens has been used as a traditional green tea for more than 1000 years and many medicinal functions of I. rubescens are also very useful, such as its well-known antitumor and antibacterial activities. Oridonin, a bioactive ent-kaurane diterpenoid, is the major ingredient of this medicinal tea. Herein, 22 novel oridonin derivatives were designed and synthesized. The antibacterial activity was evaluated for the first time. Compound 12 was the most promising one with MIC of 2.0 μg/mL against B. subtilis, which was nearly 3-fold stronger than positive control chloromycetin. The antiproliferative property was also assayed and compound 19 showed stronger activity than taxol. The apoptosis-inducing ability, cell cycle arrest effect at S phase and influence of mitochondrial membrane potential by 19 in CaEs-17 cancer cells were first disclosed. Based on the above results, the cell apoptosis induced by compound 19 in CaEs-17 cells was most probably involved in the intrinsic apoptotic pathway.

  16. The investigation of antibacterial activity of selected native plants from North of Iran.

    Science.gov (United States)

    Koohsari, H; Ghaemi, E A; Sadegh Sheshpoli, M; Jahedi, M; Zahiri, M

    2015-01-01

    Plant derived products have been used for medicinal purposes during centuries. Bacterial resistance to currently used antibiotics has become a concern to public health. The development of bacterial super resistant strains has resulted in the currently used antibiotic agents failing to end many bacterial infections. For this reason, the search is ongoing for new antimicrobial agents, both by the design and by the synthesis of new agents, or through the search of natural sources for yet undiscovered antimicrobial agents. Herbal medications in particular have seen a revival of interest due to a perception that there is a lower incidence of adverse reactions to plant preparations compared to synthetic pharmaceuticals. Coupled with the reduced costs of plant preparations, this makes the search for natural therapeutics an attractive option. This research was carried out to assess the antibacterial activity aqueous and ethanolic extracts of six Azadshahr township Native plants in north of Iran against six species of pathogen bacteria by using three methods of Disk diffusion, Well method and MBC. The results of this research indicated that the effect of ethanol extracts were more than aqueous extract and among six plants, Lippia citriodora and Plantago major ethanol extract had the most antibacterial activity in any of the three methods. Gram-positive bacteria were more sensitive than gram-negative bacteria. Staphylococcus epidermidis and Staphylococcus aureus were the most susceptible Gram-positive bacteria.

  17. Antibacterial activity of large-area monolayer graphene film manipulated by charge transfer.

    Science.gov (United States)

    Li, Jinhua; Wang, Gang; Zhu, Hongqin; Zhang, Miao; Zheng, Xiaohu; Di, Zengfeng; Liu, Xuanyong; Wang, Xi

    2014-03-12

    Graphene has attracted increasing attention for potential applications in biotechnology due to its excellent electronic property and biocompatibility. Here we use both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) to investigate the antibacterial actions of large-area monolayer graphene film on conductor Cu, semiconductor Ge and insulator SiO2. The results show that the graphene films on Cu and Ge can surprisingly inhibit the growth of both bacteria, especially the former. However, the proliferation of both bacteria cannot be significantly restricted by the graphene film on SiO2. The morphology of S. aureus and E. coli on graphene films further confirms that the direct contact of both bacteria with graphene on Cu and Ge can cause membrane damage and destroy membrane integrity, while no evident membrane destruction is induced by graphene on SiO2. From the viewpoint of charge transfer, a plausible mechanism is proposed here to explain this phenomenon. This study may provide new insights for the better understanding of antibacterial actions of graphene film and for the better designing of graphene-based antibiotics or other biomedical applications.

  18. Understanding the properties of chitosan aryl substituted thioureas in their role and potential as antibacterial agents

    Science.gov (United States)

    Khairul, Wan M.; Daud, Adibah Izzati; Ismail, Noraznawati

    2018-02-01

    In this study, the effort was to design and synthesize a series of thiourea-chitosan derivatives featuring five aryl substituted members namely N-chitosan-N'-(4-nitrobenzoyl) thiourea (1), N-chitosan-N'-(4-chlorobenzoyl) thiourea (2), N-chitosan-N'-(4-methylbenzoyl) thiourea (3), N-chitosan-N'-(2-iodobenzoyl) thiourea (4), and N-chitosan-N'-(2-methylbenzoyl) thiourea (5) via SN2 reaction pathway having different donating and withdrawing groups. Their molecular structures were then characterised by FT-IR, UV-Vis, and thermogravimetric analysis (TGA). The antimicrobial activities of these derivatives against four species bacteria Bacillus cereus, Staphylococcus aureus, Salmonella typhi, and Escherichia coli of both Gram-positive and Gram-negative type bacteria at minimum concentration 6mg/ml were carried out to investigate their potential as antibacterial agents. Compound 1 exhibited specific activity as it can only inhibit Gram-positive bacteria while other compounds 2-5 showed broad range spectrum activity as they were able to inhibit both Gram-positive and Gram-negative bacteria. Therefore, 1-5 showed good antibacterial activity and have high potential to be further developed as active materials in pharmaceutical interests.

  19. Synthesis of Azole-containing Piperazine Derivatives and Evaluation of their Antibacterial, Antifungal and Cytotoxic Activities

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Lin Ling; Fang, Bo; Zhou, Cheng He [Southwest University, Chongqing (China)

    2010-12-15

    A series of azole-containing piperazine derivatives have been designed and synthesized. The obtained compounds were investigated in vitro for their antibacterial, antifungal and cytotoxic activities. The preliminary results showed that most compounds exhibited moderate to significant antibacterial and antifungal activities in vitro. 1-(4-((4-chlorophenyl) (phenyl)methyl)piperazin-1-yl)-2-(1H-imidazol-1-yl)ethanone and 1-(4-((4-Chlorophenyl)(phenyl)methyl)piperazin-1- yl)-2-(2-phenyl-1H-imidazol-1-yl)ethanone gave remarkable and broad-spectrum antimicrobial efficacy against all tested strains with MIC values ranging from 3.1 to 25 μg/mL, and exhibited comparable activities to the standard drugs chloramphenicol and fluconazole in clinic. Moreover, 2-((4-((4-chlorophenyl)(phenyl)methyl)piperazin-1-yl)methyl)- 1H-benzo[d]imidazole was found to be the most effective in vitro against the PC-3 cell line, reaching growth inhibition values (36.4, 60.1 and 76.5%) for each tested concentration: 25 μM, 50 μM and 100 μM in dose-dependent manner. The results also showed that the azole ring had noticeable effect on their antimicrobial and cytotoxic activities, and imidazole and benzimidazole moiety were much more favourable to biological activity than 1,2,4-triazole.

  20. Superparamagnetic nickel colloidal nanocrystal clusters with antibacterial activity and bacteria binding ability

    Science.gov (United States)

    Peng, Bo; Zhang, Xinglin; Aarts, Dirk G. A. L.; Dullens, Roel P. A.

    2018-06-01

    Recent progress in synthetic nanotechnology and the ancient use of metals in food preservation and the antibacterial treatment of wounds have prompted the development of nanometallic materials for antimicrobial applications1-4. However, the materials designed so far do not simultaneously display antimicrobial activity and the capability of binding and capturing bacteria and spores. Here, we develop a one-step pyrolysis procedure to synthesize monodisperse superparamagnetic nickel colloidal nanocrystal clusters (SNCNCs), which show both antibacterial activity and the ability to bind Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria, as well as bacterial spores. The SNCNCs are formed from a rapid burst of nickel nanoparticles, which self-assemble slowly into clusters. The clusters can magnetically extract 99.99% of bacteria and spores and provide a promising approach for the removal of microbes, including hard-to-treat microorganisms. We believe that our work illustrates the exciting opportunities that nanotechnology offers for alternative antimicrobial strategies and other applications in microbiology.

  1. Fundamentals and Catalytic Innovation: The Statistical and Data Management Center of the Antibacterial Resistance Leadership Group.

    Science.gov (United States)

    Huvane, Jacqueline; Komarow, Lauren; Hill, Carol; Tran, Thuy Tien T; Pereira, Carol; Rosenkranz, Susan L; Finnemeyer, Matt; Earley, Michelle; Jiang, Hongyu Jeanne; Wang, Rui; Lok, Judith; Evans, Scott R

    2017-03-15

    The Statistical and Data Management Center (SDMC) provides the Antibacterial Resistance Leadership Group (ARLG) with statistical and data management expertise to advance the ARLG research agenda. The SDMC is active at all stages of a study, including design; data collection and monitoring; data analyses and archival; and publication of study results. The SDMC enhances the scientific integrity of ARLG studies through the development and implementation of innovative and practical statistical methodologies and by educating research colleagues regarding the application of clinical trial fundamentals. This article summarizes the challenges and roles, as well as the innovative contributions in the design, monitoring, and analyses of clinical trials and diagnostic studies, of the ARLG SDMC. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  2. Antibacterial and antibiofouling clay nanotube–silicone composite

    Directory of Open Access Journals (Sweden)

    Boyer CJ

    2018-04-01

    Full Text Available CJ Boyer,1 J Ambrose Jr,2 S Das,1 A Humayun,1 D Chappidi,1 R Giorno,3 DK Mills2,3 1Molecular Science and Nanotechnology, College of Engineering & Science, Louisiana Tech University, Ruston, LA, USA; 2Center for Biomedical Engineering and Rehabilitation Science, Louisiana Tech University, Ruston, LA, USA; 3School of Biological Sciences, Louisiana Tech University, Ruston, LA, USA Introduction: Invasive medical devices are used in treating millions of patients each day. Bacterial adherence to their surface is an early step in biofilm formation that may lead to infection, health complications, longer hospital stays, and death. Prevention of bacterial adherence and biofilm development continues to be a major healthcare challenge. Accordingly, there is a pressing need to improve the anti-microbial properties of medical devices. Materials and Methods: Polydimethylsiloxane (PDMS was doped with halloysite nanotubes (HNTs, and the PDMS-HNT composite surfaces were coated with PDMS-b-polyethylene oxide (PEO and antibacterials. The composite material properties were examined using SEM, energy dispersive spectroscopy, water contact angle measurements, tensile testing, UV-Vis spectroscopy, and thermal gravimetric analysis. The antibacterial potential of the PDMS-HNT composites was compared to commercial urinary catheters using cultures of E. coli and S. aureus. Fibrinogen adsorption studies were also performed on the PDMS-HNT-PEO composites. Results: HNT addition increased drug load during solvent swelling without reducing material strength. The hydrophilic properties provided by PEO were maintained after HNT addition, and the composites displayed protein-repelling properties. Additionally, composites showed superiority over commercial catheters at inhibiting bacterial growth. Conclusion: PDMS-HNT composites showed superiority regarding their efficacy at inhibiting bacterial growth, in comparison to commercial antibacterial catheters. Our data suggest that

  3. Screening and antibacterial efficacy of selected Indian medicinal plants

    Institute of Scientific and Technical Information of China (English)

    Suresh Mickymaray; Mohammad Saleh Al Aboody; Pradipta Kumar Rath; Panneerselvam Annamalai; Thajuddin Nooruddin

    2016-01-01

    Objective: To evaluate the antibacterial efficacy of five Indian medicinal plants such as Acalypha indica L.(A. indica), Aerva lanata(L.) Juss. ex Schult.(A. lanata), Clerodendrum inerme(L.) Gaertn., Pergularia daemia(Forsk.) Chiov. and Solanum surattense Burm. f. against opportunistic bacterial pathogens isolated from HIV infected patients for the potential phytoconstituents in plant extracts.Methods: The opportunistic bacterial pathogens such as Escherichia coli(E. coli),Pseudomonas aeruginosa, Salmonella typhi and Serratia marcescens from Gramnegative group and Staphylococcus aureus from Gram-positive group were isolated from HIV infected patients. The antibacterial efficacy of ethanolic extracts of selected medicinal plants was carried out by disc diffusion method. The potential phytoconstituents of medicinal plant extracts were identified by gas chromatography and mass spectrometry(GC–MS) analysis.Results: Among the five medicinal plants tested, A. indica and A. lanata showed the significant antibacterial activity. A. indica showed potential activity against Staphylococcus aureus and E. coli. A. lanata significantly exhibited antibacterial activity against E. coli, Salmonella typhi and Pseudomonas aeruginosa. A total of 19 phytoconstituents were identified in the ethanolic extract of A. indica and A. lanata by GC–MS analysis respectively.Conclusions: The results of the present investigation revealed that A. indica and A. lanata, possessed significant antibacterial activity when compared with the other plant extracts tested. The presence of 3-O-methyl-D-glucose by GC–MS analysis in both A. indica and A. lanata extracts has not been reported elsewhere in the literature and the findings in this study could be the first one to report.

  4. Silk fibroin based antibacterial bionanotextiles as wound dressing materials

    Energy Technology Data Exchange (ETDEWEB)

    Çalamak, Semih [Hacettepe University, Faculty of Pharmacy, Department of Basic Pharmaceutical Sciences, 06100 Ankara (Turkey); Hacettepe University, Department of Nanotechnology and Nanomedicine, 06800 Ankara (Turkey); Erdoğdu, Ceren; Özalp, Meral [Hacettepe University, Faculty of Pharmacy, Department of Pharmaceutical Microbiology, 06100 Ankara (Turkey); Ulubayram, Kezban, E-mail: ukezban@hacettepe.edu.tr [Hacettepe University, Faculty of Pharmacy, Department of Basic Pharmaceutical Sciences, 06100 Ankara (Turkey); Hacettepe University, Department of Nanotechnology and Nanomedicine, 06800 Ankara (Turkey)

    2014-10-01

    New applications for medical biotextiles have been identified with the development of nanotechnological manufacturing technologies. Combination of nanotechnology and biotextile technology has resulted into a new field called bionanotextiles. Bionanotextiles are used in many areas which include wound dressings, bandages and tissue scaffolds. Silk fibroin (SF) from the cocoon of Bombyx mori, is one of the most favorable wound dressing materials due to its unique properties including biocompatibility, permeability, biodegradability, morphologic flexibility, and proper mechanical properties. The modification of antimicrobial properties of SFs can provide a barrier for bacterial penetration as wound dressing materials. In the present study, antibacterial polyethylenimine (PEI) (10, 20 and 30% (w/w)) was blended with SF and bionanotextiles were successfully fabricated by electrospinning. In addition, silk fibroin nanofibers were also functionalized with sulphate group in order to test whether they exhibit an antibacterial activity or not. Fibroin based bionanotextiles were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The cytotoxicity evaluations were carried out by L929 fibroblasts with MTT assay. The indirect cytotoxicity results demonstrate that all fibroin and PEI/fibroin extracts have no cytotoxicity on L929 cancer cell line. PEI/fibroin bionanotextiles showed strong antibacterial activities against gram positive Staphylococcus aureus and gram negative Pseudomonas aeruginosa. - Highlights: • Bionanotextiles are combination of nanotechnology and biotextile technology. • Bionanotextiles have good antibacterial activity against both of S. aureus and P. aeruginosa. • Antibacterial bionanotextiles are applicable to most of the infected wounds. • No cytotoxicity was observed on L929 cell line.

  5. Silk fibroin based antibacterial bionanotextiles as wound dressing materials

    International Nuclear Information System (INIS)

    Çalamak, Semih; Erdoğdu, Ceren; Özalp, Meral; Ulubayram, Kezban

    2014-01-01

    New applications for medical biotextiles have been identified with the development of nanotechnological manufacturing technologies. Combination of nanotechnology and biotextile technology has resulted into a new field called bionanotextiles. Bionanotextiles are used in many areas which include wound dressings, bandages and tissue scaffolds. Silk fibroin (SF) from the cocoon of Bombyx mori, is one of the most favorable wound dressing materials due to its unique properties including biocompatibility, permeability, biodegradability, morphologic flexibility, and proper mechanical properties. The modification of antimicrobial properties of SFs can provide a barrier for bacterial penetration as wound dressing materials. In the present study, antibacterial polyethylenimine (PEI) (10, 20 and 30% (w/w)) was blended with SF and bionanotextiles were successfully fabricated by electrospinning. In addition, silk fibroin nanofibers were also functionalized with sulphate group in order to test whether they exhibit an antibacterial activity or not. Fibroin based bionanotextiles were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The cytotoxicity evaluations were carried out by L929 fibroblasts with MTT assay. The indirect cytotoxicity results demonstrate that all fibroin and PEI/fibroin extracts have no cytotoxicity on L929 cancer cell line. PEI/fibroin bionanotextiles showed strong antibacterial activities against gram positive Staphylococcus aureus and gram negative Pseudomonas aeruginosa. - Highlights: • Bionanotextiles are combination of nanotechnology and biotextile technology. • Bionanotextiles have good antibacterial activity against both of S. aureus and P. aeruginosa. • Antibacterial bionanotextiles are applicable to most of the infected wounds. • No cytotoxicity was observed on L929 cell line

  6. Mur Ligase Inhibitors as Anti-bacterials: A Comprehensive Review.

    Science.gov (United States)

    Sangshetti, Jaiprakash N; Joshi, Suyog S; Patil, Rajendra H; Moloney, Mark G; Shinde, Devanand B

    2017-01-01

    Exploring a new target for antibacterial drug discovery has gained much attention because of the emergence of Multidrug Resistance (MDR) strains of bacteria. To overcome this problem the development of novel antibacterial was considered as highest priority task and was one of the biggest challenge since multiple factors were involved. The bacterial peptidoglycan biosynthetic pathway has been well documented in the last few years and has been found to be imperative source for the development of novel antibacterial agents with high target specificity as they are essential for bacterial survival and have no homologs in humans. We have therefore reviewed the process of peptidoglycan biosynthesis which involves various steps like formation of UDP-Nacetylglucosamine (GlcNAc), UDP-N-acetylmuramic acid (MurNAc) and lipid intermediates (Lipid I and Lipid II) which are controlled by various enzymes like GlmS, GlmM, GlmU enzyme, followed by Mur Ligases (MurAMurF) and finally by MraY and MurG respectively. These four amide ligases MurC-MurF can be used as the source for the development of novel multi-target antibacterial agents as they shared and conserved amino acid regions, catalytic mechanisms and structural features. This review begins with the need for novel antibacterial agents and challenges in their development even after the development of bacterial genomic studies. An overview of the peptidoglycan monomer formation, as a source of disparity in this process is presented, followed by detailed discussion of structural and functional aspects of all Mur enzymes and different chemical classes of their inhibitors along with their SAR studies and inhibitory potential. This review finally emphasizes on different patents and novel Mur inhibitors in the development phase. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Antibacterial and Antibiotic-Modifying Activity of Methanol Extracts from Six Cameroonian Food Plants against Multidrug-Resistant Enteric Bacteria

    Directory of Open Access Journals (Sweden)

    Joachim K. Dzotam

    2017-01-01

    Full Text Available The present work was designed to investigate the antibacterial activities of methanol extracts from six Cameroonian edible plants and their synergistic effects with some commonly used antibiotics against multidrug-resistant (MDR Gram-negative bacteria expressing active efflux pumps. The extracts were subjected to qualitative phytochemical screening and the microdilution broth method was used for antibacterial assays. The results of phytochemical tests indicate that all tested crude extracts contained polyphenols, flavonoids, triterpenes, and steroids. Extracts displayed selective antibacterial activities with the minimal inhibitory concentration (MIC values ranging from 32 to 1024 μg/mL. The lowest MIC value (32 μg/mL was recorded with Coula edulis extract against E. coli AG102 and K. pneumoniae K2 and with Mangifera indica bark extract against P. aeruginosa PA01 and Citrus sinensis extract against E. coli W3110 which also displayed the best MBC (256 μg/mL value against E. coli ATCC8739. In combination with antibiotics, extracts from M. indica leaves showed synergistic effects with 75% (6/8 of the tested antibiotics against more than 80% of the tested bacteria. The findings of the present work indicate that the tested plants may be used alone or in combination in the treatment of bacterial infections including the multidrug-resistant bacteria.

  8. Screening of marine algae (Padina sp. from the Lengeh Port, Persian Gulf for antibacterial and antifungal activities

    Directory of Open Access Journals (Sweden)

    Azadeh Taherpour

    2016-09-01

    Full Text Available Objective: To evaluate the antibacterial efficacy of different solvent extracts of Padina sp. against selected human pathogenic bacteria and fungi species such as Escherichia coli, Shigella sp., Staphylococcus aureus (S. aureus, Pseudomonas aeruginosa, Aspergillus flavus and Candida albicans. Methods: Various solvents including methanol, ethyl acetate, chloroform and hexane were used to acquire crude extracts from marine algae Padina sp. After crude preparation, antibacterial and antifungal activities were screened against clinically important human pathogenic bacteria using disc and well diffusion methods. For all the bacterial species used in this research, minimum inhibitory concentration was undertaken considering various solvent extracts of Padina sp. To ensure the accuracy of experiments, a positive control was also included. Results: Confirmed that hexane is the best solvent to extract antimicrobial agents from Padina sp. Among selected bacteria, S. aureus was the most sensitive test microorganism. While, all other microorganisms showed resistance against methanol, ethyl acetate, chloroform extracts. In fact, by increasing concentration of hexane extract, inhibition of S. aureus growth or antimicrobial activity was increased. Growth inhibition zone in well method showed better results compared to disc diffusion method. The minimum inhibitory concentration and minimum bactericidal concentration of hexane extract were 15 and 30 mg/mL against S. aureus, respectively. All Padina sp. extracts did not reveal any antifungal activities against fungi species in this study. Conclusions: Brown algae extracts showed sufficient antibacterial properties against S. aureus. Therefore, Padina sp. in this research can be a good candidate to design and manufacture novel antibacterial agents used in pharmaceutical industries.

  9. Antibacterial and wound healing properties of chitosan/poly(vinyl alcohol)/zinc oxide beads (CS/PVA/ZnO).

    Science.gov (United States)

    Gutha, Yuvaraja; Pathak, Janak L; Zhang, Weijiang; Zhang, Yaping; Jiao, Xu

    2017-10-01

    Treatment against bacterial infection is crucial for wound healing. Development of cost-effective antibacterial agent with wound healing properties is still in high demand. In this study we aimed to design chitosan/poly(vinyl alcohol)/zinc oxide (CS/PVA/ZnO) beads as novel antibacterial agent with wound healing properties. CS/PVA/ZnO beads were synthesized, and characterized by using XRD, FTIR, SEM, and TEM analysis. Pure chitosan exhibits two peaks at 2θ=10 and 20 and the CS/PVA polymer matrix exhibit the peaks at 2θ=19.7° and another of low intensity at 2θ=11.5°. Pure ZnO shows the characteristic peaks at (100), (002), (101), (102), (110), (103), (200), and (112) that were in good agreement with wurtzite ore having hexagonal lattice structure. The antibacterial activity of CS/PVA/ZnO against Escherichia coli, and Staphylococcus aureus were evaluated with the zone of inhibition method. Antibacterial activity of CS/PVA/ZnO was higher than that of chitosan (CS) and poly(vinyl alcohol (PVA). Hemocompatibility and biocompatibility of CS/PVA/ZnO were tested in in vitro. Wound healing properties of CS/PVA/ZnO were tested in mice skin wound. CS/PVA/ZnO showed strong antimicrobial, wound healing effect, hemocompatibility and biocompatibility. Hence the results strongly support the possibility of using this novel CS/PVA/ZnO material for the anti bacterial and wound healing application. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Protein-only, antimicrobial peptide-containing recombinant nanoparticles with inherent built-in antibacterial activity.

    Science.gov (United States)

    Serna, Naroa; Sánchez-García, Laura; Sánchez-Chardi, Alejandro; Unzueta, Ugutz; Roldán, Mónica; Mangues, Ramón; Vázquez, Esther; Villaverde, Antonio

    2017-09-15

    The emergence of bacterial antibiotic resistances is a serious concern in human and animal health. In this context, naturally occurring cationic antimicrobial peptides (AMPs) might play a main role in a next generation of drugs against bacterial infections. Taking an innovative approach to design self-organizing functional proteins, we have generated here protein-only nanoparticles with intrinsic AMP microbicide activity. Using a recombinant version of the GWH1 antimicrobial peptide as building block, these materials show a wide antibacterial activity spectrum in absence of detectable toxicity on mammalian cells. The GWH1-based nanoparticles combine clinically appealing properties of nanoscale materials with full biocompatibility, structural and functional plasticity and biological efficacy exhibited by proteins. Because of the largely implemented biological fabrication of recombinant protein drugs, the protein-based platform presented here represents a novel and scalable strategy in antimicrobial drug design, that by solving some of the limitations of AMPs offers a promising alternative to conventional antibiotics. The low molecular weight antimicrobial peptide GWH1 has been engineered to oligomerize as self-assembling protein-only nanoparticles of around 50nm. In this form, the peptide exhibits potent and broad antibacterial activities against both Gram-positive and Gram-negative bacteria, without any harmful effect over mammalian cells. As a solid proof-of-concept, this finding strongly supports the design and biofabrication of nanoscale antimicrobial materials with in-built functionalities. The protein-based homogeneous composition offer advantages over alternative materials explored as antimicrobial agents, regarding biocompatibility, biodegradability and environmental suitability. Beyond the described prototype, this transversal engineering concept has wide applicability in the design of novel nanomedicines for advanced treatments of bacterial infections

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

    Directory of Open Access Journals (Sweden)

    Fan Yu

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

  12. Antibacterial silver nanocluster/silica composite coatings on stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, M.; Perero, S. [Politecnico di Torino, Department of Applied Science and Technology, Torino, C.so Duca degli Abruzzi 24, I-10129 (Italy); Ferraris, S., E-mail: sara.ferraris@polito.it [Politecnico di Torino, Department of Applied Science and Technology, Torino, C.so Duca degli Abruzzi 24, I-10129 (Italy); Miola, M.; Vernè, E. [Politecnico di Torino, Department of Applied Science and Technology, Torino, C.so Duca degli Abruzzi 24, I-10129 (Italy); Skoglund, S. [KTH Royal Institute of Technology, Div. Surface and Corrosion Science, Dr. Kristinas v. 51, SE-100 44 (Sweden); Blomberg, E. [KTH Royal Institute of Technology, Div. Surface and Corrosion Science, Dr. Kristinas v. 51, SE-100 44 (Sweden); SP Technical Research Institute of Sweden, Chemistry, Materials and Surfaces, P.O. Box 5607, SE-114 86 Stockholm (Sweden); Odnevall Wallinder, I. [KTH Royal Institute of Technology, Div. Surface and Corrosion Science, Dr. Kristinas v. 51, SE-100 44 (Sweden)

    2017-02-28

    Highlights: • A silver nanocluster-silica composite coating sputter-deposited onto stainless steel. • Good adhesion and resistance upon cleaning with NaOH, H{sub 2}SO{sub 4} and detergents. • Low release of silver ions and no release as silver nanoparticles. • Good antibacterial activity against S. aureus even after heating to 450 °C. • Good antibacterial activity shown during cheese production. - Abstract: A coating made of silver nanocluster/silica composites has been deposited, via a radio frequency (RF) co-sputtering technique, for the first time onto stainless steel (AISI 304L) with the aim to improve its antibacterial properties. Different thermal treatments after coating deposition have been applied in order to optimize the coating adhesion, cohesion and its antibacterial properties. Its applicability has been investigated at realistic conditions in a cheese production plant. The physico-chemical characteristics of the coatings have been analyzed by means of different bulk and surface analytical techniques. Field emission scanning electron microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM) were employed to assess coating morphology, composition, surface roughness, wetting properties, size and local distribution of the nanoparticles within the coating. Tape tests were used to determine the adhesion/cohesion properties of the coating. The amount and time-dependence of released silver in solutions of acetic acid, artificial water, artificial tap water and artificial milk were determined by means of Atomic Absorption Spectroscopy (AAS). The antibacterial effect of the coating was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus in compliance with National Committee for Clinical Laboratory Standards (NCCLS) and AATCC 147 standards. The Ahearn test was performed to measure the adhesion of bacteria to the coated stainless steel

  13. Antibacterial silver nanocluster/silica composite coatings on stainless steel

    International Nuclear Information System (INIS)

    Ferraris, M.; Perero, S.; Ferraris, S.; Miola, M.; Vernè, E.; Skoglund, S.; Blomberg, E.; Odnevall Wallinder, I.

    2017-01-01

    Highlights: • A silver nanocluster-silica composite coating sputter-deposited onto stainless steel. • Good adhesion and resistance upon cleaning with NaOH, H_2SO_4 and detergents. • Low release of silver ions and no release as silver nanoparticles. • Good antibacterial activity against S. aureus even after heating to 450 °C. • Good antibacterial activity shown during cheese production. - Abstract: A coating made of silver nanocluster/silica composites has been deposited, via a radio frequency (RF) co-sputtering technique, for the first time onto stainless steel (AISI 304L) with the aim to improve its antibacterial properties. Different thermal treatments after coating deposition have been applied in order to optimize the coating adhesion, cohesion and its antibacterial properties. Its applicability has been investigated at realistic conditions in a cheese production plant. The physico-chemical characteristics of the coatings have been analyzed by means of different bulk and surface analytical techniques. Field emission scanning electron microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), contact angle measurements and atomic force microscopy (AFM) were employed to assess coating morphology, composition, surface roughness, wetting properties, size and local distribution of the nanoparticles within the coating. Tape tests were used to determine the adhesion/cohesion properties of the coating. The amount and time-dependence of released silver in solutions of acetic acid, artificial water, artificial tap water and artificial milk were determined by means of Atomic Absorption Spectroscopy (AAS). The antibacterial effect of the coating was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus in compliance with National Committee for Clinical Laboratory Standards (NCCLS) and AATCC 147 standards. The Ahearn test was performed to measure the adhesion of bacteria to the coated stainless steel surface

  14. Synthesis, screening and QSAR studies of 3-benzoyl-2-oxo/thioxo-1,2,3,4-tetrahydro-pyrimidine analogues as antibacterial agents

    Directory of Open Access Journals (Sweden)

    Ramesh L. Sawant

    2008-12-01

    Full Text Available The purpose of this study was to synthesize several 3-benzoyl-5-acyl-6-methyl-4-substituted-2-oxo/thioxo-1,2,3,4-tetrahydropyrimidines, evaluate them for their antibacterial activity and to establish correlation between the activity and physicochemical properties. 5-Acyl-6-methyl-4-substituted-2-oxo/thioxo-1,2,3,4-tetrahydropyrimidines (A were synthesized by cyclocondensation reaction between appropriate aldehyde, acetoacetate and urea/thiourea in presence of aluminium chloride and hydrochloric acid which upon treatment with benzoyl chloride in presence of pyridine in benzene furnish the title compounds (1-28. The structures of all title compounds have been confirmed on the basis of their analytical, IR and NMR spectral data. The title compounds have been tested for antibacterial activity against Staphylococcus aureus. The compounds were divided into training and test sets. A quantitative structure activity relationship study was made using various descriptors. Several statistical expressions were developed using stepwise multiple linear regression analysis. The best quantitative structure activity relationship model was further cross validated. The study revealed that total positive partial charge (PC+ and total polar negative Van der Waals surface area (Q_VSA_PNEG contributes negatively where as contribution of Van der Waals surface area to molar refractivity (SMR_VSA7 contributes positively to the antibacterial activity. The compounds with improved antibacterial potential can be successfully designed with selected quantitative structure activity relationship model.

  15. Chitosan encapsulation of essential oil "cocktails" with well-defined binary Zn(II)-Schiff base species targeting antibacterial medicinal nanotechnology.

    Science.gov (United States)

    Halevas, Eleftherios; Nday, Christiane M; Chatzigeorgiou, Evanthia; Varsamis, Vasileios; Eleftheriadou, Despoina; Jackson, Graham E; Litsardakis, Georgios; Lazari, Diamanto; Ypsilantis, Konstantinos; Salifoglou, Athanasios

    2017-11-01

    The advent of biodegradable nanomaterials with enhanced antibacterial activity stands as a challenge to the global research community. In an attempt to pursue the development of novel antibacterial medicinal nanotechnology, we herein a) synthesized ionic-gelated chitosan nanoparticles, b) compared and evaluated the antibacterial activity of essential oils extracted from nine different herbs (Greek origin) and their combinations with a well-defined antibacterial Zn(II)-Schiff base compound, and c) encapsulated the most effective hybrid combination of Zn(II)-essential oils inside the chitosan matrix, thereby targeting well-formulated nanoparticles of distinct biological impact. The empty and loaded chitosan nanoparticles were physicochemically characterized by FT-IR, Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), with the entrapment and drug release studies being conducted through UV-Visible and atomic absorption techniques. The antimicrobial properties of the novel hybrid materials were demonstrated against Gram positive (S. aureus, B. subtilis, and B. cereus) and Gram negative (E. coli and X. campestris) bacteria using modified agar diffusion methods. The collective physicochemical profile of the hybrid Zn(II)-essential oil cocktails, formulated so as to achieve optimal activity when loaded to chitosan nanoparticles, signifies the importance of design in the development of efficient nanomedicinal pharmaceuticals a) based on both natural products and biogenic metal ionic cofactors, and b) targeting bacterial infections and drug resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Antibacterial nanocarriers of resveratrol with gold and silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sohyun [College of Pharmacy, Inje University, 197 Inje-ro Gimhae, Gyeongnam 621-749 (Korea, Republic of); Cha, Song-Hyun [National Creative Research Initiatives (NCRI) Center for Isogeometric Optimal Design, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Cho, Inyoung [School of Civil, Environmental and Architecture Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Park, Soomin [National Creative Research Initiatives (NCRI) Center for Isogeometric Optimal Design, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Park, Yohan [College of Pharmacy, Inje University, 197 Inje-ro Gimhae, Gyeongnam 621-749 (Korea, Republic of); Cho, Seonho [National Creative Research Initiatives (NCRI) Center for Isogeometric Optimal Design, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Park, Youmie, E-mail: youmiep@inje.ac.kr [College of Pharmacy, Inje University, 197 Inje-ro Gimhae, Gyeongnam 621-749 (Korea, Republic of); National Creative Research Initiatives (NCRI) Center for Isogeometric Optimal Design, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

    2016-01-01

    This study focused on the preparation of resveratrol nanocarrier systems and the evaluation of their in vitro antibacterial activities. Gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) for resveratrol nanocarrier systems were synthesized using green synthetic routes. During the synthesis steps, resveratrol was utilized as a reducing agent to chemically reduce gold and silver ions to AuNPs and AgNPs. This system provides green and eco-friendly synthesis routes that do not involve additional chemical reducing agents. Resveratrol nanocarriers with AuNPs (Res-AuNPs) and AgNPs (Res-AgNPs) were observed to be spherical and to exhibit characteristic surface plasmon resonance at 547 nm and at 412–417 nm, respectively. The mean size of the nanoparticles ranged from 8.32 to 21.84 nm, as determined by high-resolution transmission electron microscopy. The face-centered cubic structure of the Res-AuNPs was confirmed by high-resolution X-ray diffraction. Fourier-transform infrared spectra indicated that the hydroxyl groups and C=C in the aromatic ring of resveratrol were involved in the reduction reaction. Res-AuNPs retained excellent colloidal stability during ultracentrifugation and re-dispersion, suggesting that resveratrol also played a role as a capping agent. Zeta potentials of Res-AuNPs and Res-AgNPs were in the range of − 20.58 to − 48.54 mV. Generally, against Gram-positive and Gram-negative bacteria, the Res-AuNPs and Res-AgNPs exhibited greater antibacterial activity compared to that of resveratrol alone. Among the tested strains, the highest antibacterial activity of the Res-AuNPs was observed against Streptococcus pneumoniae. The addition of sodium dodecyl sulfate during the synthesis of Res-AgNPs slightly increased their antibacterial activity. These results suggest that the newly developed resveratrol nanocarrier systems with metallic nanoparticles show potential for application as nano-antibacterial agents with enhanced activities. - Highlights

  17. Antibacterial activity of nitric oxide releasing silver nanoparticles

    Science.gov (United States)

    Seabra, Amedea B.; Manosalva, Nixson; de Araujo Lima, Bruna; Pelegrino, Milena T.; Brocchi, Marcelo; Rubilar, Olga; Duran, Nelson

    2017-06-01

    Silver nanoparticles (AgNPs) are well known potent antimicrobial agents. Similarly, the free radical nitric oxide (NO) has important antibacterial activity, and due to its instability, the combination of NO and nanomaterials has been applied in several biomedical applications. The aim of this work was to synthesize, characterize and evaluate the antibacterial activity of a new NO-releasing AgNPs. Herein, AgNPs were synthesized by the reduction of silver ions (Ag+) by catechin, a natural polyphenol and potent antioxidant agent, derived from green tea extract. Catechin acts as a reducing agent and as a capping molecule on the surface of AgNPs, minimizing particle agglomeration. The as-synthesized nanoparticles were characterized by different techniques. The results showed the formation of AgNPs with average hydrodynamic size of 44 nm, polydispersity index of 0.21, and zeta potential of -35.9 mV. X-ray diffraction and Fourier transform infrared spectroscopy revealed the presence of the AgNP core and cathecin as capping agent. The low molecular weight mercaptosuccinic acid (MSA), which contain free thiol group, was added on the surface of catechin-AgNPs, leading to the formation of MSA-catechin-AgNPs (the NO precursor nanoparticle). Free thiol groups of MSA-catechin-AgNPs were nitrosated leading to the formation of S-nitroso-mercaptosuccinic acid (S-nitroso-MSA), the NO donor. The amount of 342 ± 16 µmol of NO was released per gram of S-nitroso-MSA-catechin-AgNPs. The antibacterial activities of catechin-AgNPs, MSA-catechin-AgNPs, and S-nitroso-MSA-catechin-AgNPs were evaluated towards different resistant bacterial strains. The results demonstrated an enhanced antibacterial activity of the NO-releasing AgNP. For instance, the minimal inhibitory concentration values for Pseudomonas aeruginosa (ATCC 27853) incubated with AgNPs-catechin, AgNPs-catechin-MSA, and AgNPs-catechin-S-nitroso-MSA were found to be 62, 125 and 3 µg/mL, respectively. While in the case of

  18. Design, synthesis, characterization and antibacterial and antifungal activity of a new 2-{(E-[(4-aminophenylimino]-methyl}-4,6-dichlorophenol and its complexes with Co(II, Ni(II, Cu(II and Zn(II: An experimental and DFT study

    Directory of Open Access Journals (Sweden)

    Bakirdere Emine Gulhan

    2016-01-01

    Full Text Available In this study, the complexes of Co (II, Ni (II, Cu (II and Zn (II with 2-(E-(4-aminophenyliminomethyl-4,6-dichlorophenol were prepared and characterized by physical, spectral and analytical data. The metal: ligand stoichiometric ratio is 1:2 in all the complexes. The results suggested that the Schiff bases are coordinated to the metal ions through the phenolic oxygens and azomethine nitrogen to give mononuclear complexes. Their structures were elucidated on the basis of elemental analysis, IR, 1H and 13C NMR spectra, UV-VIS, magnetic susceptibility measurements and thermogravimetric analyses. Both the antibacterial and antifungal activities and MIC values of compounds were reported. Among the tested compounds, the most effective compound providing a MIC value of 64 μg/mL is Zn(L2 against C. tropicalis and B. subtilis. The theoretically optimized geometries of complexes have tetrahedral structures. The computed stretching frequencies of C=N, C-O and N-H bonds were found to be in good agreement with experimental data. All calculated frequencies fall within about 5% of the experimental frequency regions.

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

    Science.gov (United States)

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

    1988-01-01

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

  20. [New antibacterial agents on the market and in the pipeline].

    Science.gov (United States)

    Kern, W V

    2015-11-01

    After some years of stagnation there have been several new successful developments in the field of antibacterial agents. Most of these new developments have been in conventional antibacterial classes. New drugs among the beta-lactam agents are methicillin-resistant Staphylococcus aureus (MRSA) active cephalosporins (ceftaroline and ceftobiprole) and new combinations of beta-lactam with beta-lactamase inhibitors (ceftolozane/tazobactam, ceftazidime/avibactam, imipenem/relebactam and meropenem/RPX7009). New developments can also be observed among oxazolidinones (tedizolid, radezolid, cadazolid and MRX-I), macrolides/ketolides (modithromycin and solithromycin), aminoglycosides (plazomicin), quinolones (nemonoxacin, delafloxacin and avarofloxacin), tetracyclines (omadacycline and eravacycline) as well as among glycopeptides and lipopeptides (oritavancin, telavancin, dalbavancin and surotomycin). New agents in a very early developmental phase are FabI inhibitors, endolysines, peptidomimetics, lipid A inhibitors, methionyl-tRNA synthetase inhibitors and teixobactin.

  1. Synthesis of photothermal nanocomposites and their application to antibacterial assays

    Science.gov (United States)

    Yang, Ning; Wang, Chun; Wang, Xiaoyu; Li, Lidong

    2018-04-01

    In this work, we report a novel gold nanorod (AuNR)-based nanocomposite that shows strong binding to bacterium and high antibacterial efficiency. The AuNRs were used as a photothermal material to transform near-infrared radiation (NIR) into heat. We selected poly (acrylic acid) to modify the surface of the AuNRs based on a simple self-assembly method. After conjugation of the bacterium-binding molecule vancomycin, the nanocomposites were capable of efficiently gathering on the cell walls of bacteria. The nanocomposites exhibited a high bacterial inhibition capability owing to NIR-induced heat generation in situ. Therefore, the prepared photothermal nanocomposites show great potential for use in antibacterial assays.

  2. Availability and usage of new antibacterial drugs in Europe.

    Science.gov (United States)

    Ziv, G

    1980-05-15

    The present-day availability and usage of established and new antibacterial drugs approved for clinical and therapeutic purposes in food-producing animals and poultry in the United States and Europe were compared. Presently, 42 such drugs are approved in Europe, 13 of which were approved since Dec 31, 1974. In the United States, 17 such drugs are currently approved, only four were approved since Dec 31, 1974. Most drug products approved in Europe contain two or more antibacterial agents, whereas most of the products approved in the United States are single drug entities. Drugs approved in Europe but not in the United States include sulfonamide and trimethoprim combinations, nafcillin, oxacillin, metampicillin, cephoxazole, cephalonium, cephacetrile, cephalexin, gentamicin, rifamycin SV, nifuroquine, tiamulin, chloramphenicol, colistin, and polymyxin B. Pharmacologic and clinical features of several of these drugs are briefly described.

  3. Antibacterial and antifungal screening of four medicinal plants

    Directory of Open Access Journals (Sweden)

    Nadjib Mohammed Rahmoun

    2014-12-01

    Full Text Available Objective: To describe the ethnopharmacology study and screening of the antimicrobial activity of hydroalcoholic and chloroform extracts of the four plants Ceratonia siliqua (C. siliqua, Salvadora persica, Aloe vera and Anastatica hierochuntica. Methods: The antimicrobial activity was determined using diffusion disk and solid agar dilution methods against 12 bacteria, according to the recommendations of the Clinical and Laboratory Standards Institute. Results: The ethnopharmacology study provided useful information about how the parts used for the preparation of extracts. The extracts obtained by maceration reveal variable yields depending on the polarity of the solvent used. The higher yields were those extracts obtained by the hydroalcoholic solvents. The Anastatica hierochuntica and C. siliqua extracts were by far the most interesting and exerted significant antibacterial activity (minimum inhibitory concentration of 0.07 to 0.13 mg/mL. Conclusions: These results suggest that C. siliqua could serve as an alternative source of antibacterial agents for human protection against infectious diseases.

  4. [Antibacterial activity of rare Streptomyces species against clinical resistant bacteria].

    Science.gov (United States)

    Boughachiche, Faiza; Reghioua, Sihem; Zerizer, Habiba; Boulahrouf, Abderrahmane

    2012-01-01

    In the search for new antibiotics from Steptomyces, investigating extremes habitats enhances the probability of isolating novel producers. In this context, the antibacterial activity of four Streptomyces strains isolated from Ezzmoul saltpans was studied. Two of them showed antibacterial activity against antibiotic's resistant bacteria (Bacillus cereus: β-lactamines and sulfamides resistant, Streptococcus faecalis: penicillin, tetracycline and cotrimoxazole resistant, and Staphylococcus aureus Mu 50: vancomycine resistant). The most active Streptomyces strain produces one type of polar bioactive molecules that resists to temperature variation and light exposition. Its activity appears in the first culture day and reaches its maximal value in the fourth day. The second strain presents themoresistant activity that reaches its maximal value in the first culture day. It produces two types of bioactive molecules, one is polar and the second is non polar (according to thin layer chromatography technique results).

  5. Activity of endodontic antibacterial agents against selected anaerobic bacteria

    Directory of Open Access Journals (Sweden)

    Ferreira Cláudio Maniglia

    2002-01-01

    Full Text Available The antimicrobial activity of substances used as antibacterial agents (solutions of 10% calcium hydroxide, camphorated paramonochlorophenol - PMCC, 2% chlorhexidine digluconate and 10% castor oil plant detergent on anaerobic bacteria (Fusobacterium nucleatum ATCC 25586, Prevotella nigrescens ATCC 33563, Clostridium perfringens ATCC 13124 and Bacteroides fragilis ATCC 25285, using a broth dilution technique, was evaluated in vitro. For determination of minimum inhibitory and minimum bactericide concentrations (MIC and MBC, two culture broths, Reinforced Clostridial Medium (RCM and supplemented Brucella, standardized inoculum and serially diluted solutions were used. All antibacterial agents presented antimicrobial activity that varied for different bacteria. There were no differences in the performance of the two broths. Chlorhexidine digluconate was the most effective, with the lowest MICs, followed by castor oil detergent, PMCC and calcium hydroxide. C. perfringens and B. fragilis were the most resistant bacteria to all agents.

  6. Antibacterial Modification of Microcrystalline Cellulose by Grafting Copolymerization

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2015-11-01

    Full Text Available Microcrystalline cellulose (MCC has the advantage of a high specific surface area as compared to that of conventional cellulose fibers. In this study the monomer methacrylamide (MAM was used to treat MCC by grafting copolymerization. SEM, FTIR, and solid 13C NMR were used to characterize the morphology and composition of MAM-g-MCC. After the chlorination of MAM-g-MCC with 10% sodium hypochlorite solution, the grafted MCC exhibited antibacterial activity as a result of the formation of N-Cl bonds. The thermal stability, antibacterial ability, and storage stability of chlorinated MAM-g-MCC were also studied. The results showed that the chlorinated MAM-g-MCC had excellent storage stability and could inactivate all S. aureus and E. coli O157:H7 within 10 min.

  7. Potential antibacterial activity of some Saudi Arabia honey

    Directory of Open Access Journals (Sweden)

    Ahmed G. Hegazi

    2017-02-01

    Full Text Available Aim: The aim of this study was to investigate the potential antibacterial activity of some Saudi Arabia honey against selected bacterial strains of medical importance. Materials and Methods: A total of 10 Saudi Arabia honey used to evaluate their antimicrobial activity against some antibiotic-resistant pathogenic bacterial strains. The bacterial strains were Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa. Results: The antibacterial activity of Saudi honey against five bacterial strains showed different levels of inhibition according to the type of honey. The overall results showed that the potential activity was differing according to the pathogen and honey type. Conclusion: It could be concluded that the Saudi honey inhibit the growth of bacterial strains and that honey can be used as complementary antimicrobial agent against selected pathogenic bacteria.

  8. Antioxidant and antibacterial activity of Rhoeo spathacea (Swartz) Stearn leaves

    OpenAIRE

    Tan, Joash Ban Lee; Lim, Yau Yan; Lee, Sui Mae

    2013-01-01

    The decoction and infusion of Rhoeo spathacea (Swartz) Stearn leaves have been recognized as a functional food particularly in South America, but has not yet gained international popularity as a beverage. The primary aim of this study was to establish the viability of R. spathacea aqueous leaf extracts as a beverage, in terms of its antioxidant activity and antibacterial activity. The antioxidant contents of aqueous and methanol leaf extracts were evaluated by the total phenolic content (TPC)...

  9. Antibacterial and antioxidant activities of Vaccinium corymbosum L. leaf extract

    OpenAIRE

    Pervin, Mehnaz; Hasnat, Md Abul; Lim, Beong Ou

    2013-01-01

    Objective: To investigate antibacterial and antioxidant activity of the leaf extract of tropical medicinal herb and food plant Vaccinium corymbosum L. (V. corymbosum) . Methods: Free radical scavenging activity on DPPH, ABTS, and nitrites were used to analyse phenolic and flavonoid contents of leaf extract. Other focuses included the determination of antioxidant enzymatic activity (SOD, CAT and GPx), metal chelating activity, reduction power, lipid peroxidation inhibition and t...

  10. Gramicidin D enhances the antibacterial activity of fluoride

    OpenAIRE

    Nelson, James W.; Zhou, Zhiyuan; Breaker, Ronald R.

    2014-01-01

    Fluoride is a toxic anion found in many natural environments. One of the major bacterial defenses against fluoride is the cell envelope, which limits passage of the membrane-impermeant fluoride anion. Accordingly, compounds that enhance the permeability of bacterial membranes to fluoride should also enhance fluoride toxicity. In this study, we demonstrate that the pore-forming antibiotic gramicidin D increases fluoride uptake in B. subtilis and that the antibacterial activity of this compound...

  11. Highly antibacterial UHMWPE surfaces by implantation of titanium ions

    Energy Technology Data Exchange (ETDEWEB)

    Delle Side, D., E-mail: domenico.delleside@le.infn.it [LEAS, Dipartimento di Matematica e Fisica “Ennio de Giorgi”, Università del Salento, Lecce (Italy); Istituto Nazionale di Fisica Nucleare – Sezione di Lecce, Lecce (Italy); Nassisi, V.; Giuffreda, E.; Velardi, L. [LEAS, Dipartimento di Matematica e Fisica “Ennio de Giorgi”, Università del Salento, Lecce (Italy); Istituto Nazionale di Fisica Nucleare – Sezione di Lecce, Lecce (Italy); Alifano, P.; Talà, A.; Tredici, S.M. [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce (Italy)

    2014-07-15

    The spreading of pathogens represents a serious threat for human beings. Consequently, efficient antimicrobial surfaces are needed in order to reduce risks of contracting severe diseases. In this work we present the first evidences of a new technique to obtain a highly antibacterial Ultra High Molecular Weight Polyethylene (UHMWPE) based on a non-stoichiometric titanium oxide coating, visible-light responsive, obtained through ion implantation.

  12. Highly antibacterial UHMWPE surfaces by implantation of titanium ions

    Science.gov (United States)

    Delle Side, D.; Nassisi, V.; Giuffreda, E.; Velardi, L.; Alifano, P.; Talà, A.; Tredici, S. M.

    2014-07-01

    The spreading of pathogens represents a serious threat for human beings. Consequently, efficient antimicrobial surfaces are needed in order to reduce risks of contracting severe diseases. In this work we present the first evidences of a new technique to obtain a highly antibacterial Ultra High Molecular Weight Polyethylene (UHMWPE) based on a non-stoichiometric titanium oxide coating, visible-light responsive, obtained through ion implantation.

  13. Bismuth subsalicylate nanoparticles with anaerobic antibacterial activity for dental applications

    Science.gov (United States)

    Vega-Jiménez, A. L.; Almaguer-Flores, A.; Flores-Castañeda, M.; Camps, E.; Uribe-Ramírez, M.; Aztatzi-Aguilar, O. G.; De Vizcaya-Ruiz, A.

    2017-10-01

    In recent years, nanomaterials have been used in the medical-dental field as new alternative antimicrobial agents. Bismuth subsalicylate (BSS) has been used as an antimicrobial agent, but the effect of BSS in the form of nanoparticles (BSS-nano) as a potential antimicrobial agent has not been tested, in specific against bacteria responsible for periodontal disease. The aim of this study was to evaluate the antibacterial effect of BSS-nano against oral anaerobic bacteria and to assess the safety of BSS-nano by evaluating their cytotoxicity in human gingival fibroblast (HGF-1) cells. BSS-nano were synthesized by laser ablation and were previously physico-chemically characterized using in vitro assays. The antibacterial activity was measured using the tetrazolium-based XTT assay, and cytotoxicity was determined using lactate dehydrogenase (LDH) and MTS assays in HGF-1 cells. Transmission electron microscopy of HGF-1 exposed to BSS-nano was also performed. BSS-nano was shown to have a primary size of 4-22 nm and a polygonal shape. Among the tested bacterial strains, those with a greater sensitivity to BSS-nano (highest concentration of 21.7 μg ml-1) were A. actinomycetemcomitans, C. gingivalis, and P. gingivalis. BSS-nano at a concentration of 60 μg ml-1 showed low cytotoxicity (6%) in HFG-1 cells and was mainly localized intracellularly in acidic vesicles. Our results indicate that the concentration of BSS-nano used as an effective antibacterial agent does not induce cytotoxicity in mammalian cells; thus, BSS-nano can be applied as an antibacterial agent in dental materials or antiseptic solutions.

  14. Deposition of silver nanoparticles on titanium surface for antibacterial effect

    Directory of Open Access Journals (Sweden)

    Liao Juan

    2010-04-01

    Full Text Available Liao Juan1, Zhu Zhimin3, Mo Anchun1,2, Li Lei1, Zhang Jingchao11State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, PR China; 2Department of Dental Implant, West China Stomatology Hospital, Sichuan University, Chengdu 610041, PR China; 3Department of Prosthodontics, West China Stomatology Hospital, Sichuan University, Chengdu 610041, PR ChinaAbstract: Microbial colonization on implanted devices and biofilm formation is a recurrent complication in implant surgery and may result in loss of implants. The aim of this study was to deposit silver nanoparticles on a titanium surface to obtain antibacterial properties. In the present study, we prepared a silver nanoparticle-modified titanium (Ti-nAg surface using silanization method. The morphology and chemical components of the Ti-nAg surface were characterized by scanning electron microscopy (SEM equipped with energy-dispersive spectroscopy (EDS. Two species of bacteria, Staphylococcus aureus and Escherichia coli, were utilized to test the antibacterial effect of the Ti-nAg treated surface. The SEM examination revealed that a small quantity of silver nanoparticles was sparsely deposited on the titanium surface. The diameter of these nanoparticles ranged from ten to several hundred nm. EDS analyses revealed that there was 4.26% of Ag present on the surface. After a 24-hour incubation, 94% of Staphylococcus aureus and over 95% of Escherichia coli had been killed on the Ti-nAg surface, and the SEM examination of anti-adhesive efficacy test showed that there were less bacteria attached to Ti-nAg surface than to a control surface of untreated Titanium. These data suggest that silver nanoparticle-modified titanium is a promising material with an antibacterial property that may be used as an implantable biomaterial.Keywords: nano-silver, titanium, antibacterial activity, silanization method

  15. Antibacterial activities of serum from the Komodo Dragon (Varanus komodoensis)

    OpenAIRE

    Mark Merchant; Danyell Henry; Rodolfo Falconi; Bekky Muscher; Judith Bryja

    2013-01-01

    Komodo dragons (Varanus komodoensis) are able to feed on large prey items by injecting a dose of toxic bacteria with their bite that, over time, kills the prey by systemic infection. Dragons also suffer bites from other members of their own species during territorial disputes and feeding frenzies. However, they do not suffer the same fate as their prey, suggesting that they have developed a strong immunity to bacterial infections. This study was undertaken to determine the antibacterial activ...

  16. Screening and antibacterial efficacy of selected Indian medicinal plants

    Directory of Open Access Journals (Sweden)

    Suresh Mickymaray

    2016-03-01

    Conclusions: The results of the present investigation revealed that A. indica and A. lanata, possessed significant antibacterial activity when compared with the other plant extracts tested. The presence of 3-O-methyl-d-glucose by GC–MS analysis in both A. indica and A. lanata extracts has not been reported elsewhere in the literature and the findings in this study could be the first one to report.

  17. Synthesis and antibacterial studies of some novel isoxazoline derivatives

    Directory of Open Access Journals (Sweden)

    TEJASKUMAR SHAH

    2007-05-01

    Full Text Available A series of 3-[3-(2,4-dichloro-5-fluorophenyl-5-(2-furyl-4,5-dihydro-1H-pyrazol-1-yl]-5-(substituted phenyl/2-thienylisoxazolines (4a-j were prepared. The structures of the isoxazoline derivatives were confirmed on the bases of elemental analysis and spectral data. The compounds were screened for their in vitro antibacterial activity using gram-positive bacteria and gram-negative bacteria.

  18. Antibacterial Activity of Hawaiian Corals: Possible Protection from Disease?

    Science.gov (United States)

    Gochfeld, D. J.; Aeby, G. S.; Miller, J. D.

    2006-12-01

    Reports of coral diseases in the Caribbean have appeared with increasing frequency over the past two decades; however, records of coral diseases in the Pacific have lagged far behind. Recent surveys of coral disease in the Hawaiian Islands indicate relatively low, but consistent, levels of disease throughout the inhabited Main and uninhabited Northwestern Hawaiian Islands, and demonstrate variation in levels of disease among the major genera of Hawaiian corals. Although little is known about immune defense to disease in corals, one potential mechanism of defense is the production of antimicrobial compounds that protect corals from pathogens. A preliminary survey of antibacterial chemical defenses among three dominant species of Hawaiian corals was undertaken. Crude aqueous extracts of Porites lobata, Pocillopora meandrina and Montipora capitata were tested against nine strains of bacteria in a growth inhibition assay. Inhibitory extracts were further tested to determine whether their effects were cytostatic or cytotoxic. The bacteria selected included known coral pathogens, potential marine pathogens found in human waste and strains previously identified from the surfaces of Hawaiian corals. Extracts from all three species of coral exhibited a high degree of antibacterial activity, but also a high degree of selectivity against different bacterial strains. In addition, some extracts were stimulatory to some bacteria. In addition to interspecific variability, extracts also exhibited intraspecific variability, both within and between sites. Hawaiian corals have significant antibacterial activity, which may explain the relatively low prevalence of disease in these corals; however, further characterization of pathogens specifically responsible for disease in Hawaiian corals is necessary before we can conclude that antibacterial activity protects Hawaiian corals from disease.

  19. Antibacterial Activity of Melanin from Cuttlefish and Squid Ink

    OpenAIRE

    Yuspihana Fitrial; Iin Khusnul Khotimah

    2017-01-01

    Marine environment comprises of many organism which are known to posses bioactive compound as a common means of self-defense or for the protection of eggs and embryos. Class Cephalopods (such as squidand cuttlefish) are notable for their defences, such as jetting escape movements, changes in colouration, toxic venom and inking.This study aims to compare the antibacterial activity of melanin from cuttlefish ink (Sepia sp.) with squid ink (Loligo sp.) against E. coli. Extraction and purificatio...

  20. IN VITRO ANTIBACTERIAL ACTIVITIES STUDY OF POLYMERIC CIPROFLOXACIN SUSPENSIONS

    OpenAIRE

    Sahoo Subhashree; Chakraborti Chandra Kanti; Behera Pradipta Kumar

    2012-01-01

    To study the in vitro antibacterial activities of mucoadhesive suspensions containing Ciprofloxacin, three different formulations were prepared by using three polymers, such as Hydroxypropyl methylcellulose (HPMC) (S1), Carbapol934 (S2) and Carbapol940 (S3), along with some common ingredients (bases). For the investigation, agar well diffusion method was performed taking Staphylococcus aureus (ATCC 25923), Bacillus subtilis and Escherichia coli (ATCC 25922). Apart from S. aureus, S1 and Cipro...

  1. Phytochemical study, antioxidant and antibacterial activities of Stemodia maritima

    Directory of Open Access Journals (Sweden)

    Francisca R. L. da Silva

    2014-01-01

    Full Text Available Stemodinol, a new natural compound, together with known compounds including jaceidin, stemodin, stemodinoside B, isocrenatoside, verbascoside, crenatoside, and isoverbascoside, were isolated from Stemodia maritima Linn. The antioxidant (DPPH method and antimicrobial activities of stemodin, stemodinoside B, and crenatoside were investigated. Among the components tested, only crenatoside isolated from the roots showed a high antioxidant power. Stemodin and stemodinoside B exhibited antibacterial activities.

  2. Antibacterial and antidermatophyte activities of some essential Oils from spices

    OpenAIRE

    El Kady, I. A. [اسماعيل عبد الرزاق القاضي; El-Maraghy, S. S. Mohamed; Eman Mostafa M.

    1993-01-01

    The inhibitory effects of ten essential oil from different spices against the growth of various isolates of bacteria representing Gram-positive (seven isolates) and Gram-negative (four isolates) were studied. Eight antibacterial agents were included for comparative purposes. Results show that essential oils of thyme (Thymus vulgaris L.), cinnamon (Cinnamomum verum Presl (Syn. C. zylanicum Blume) and cardamom (Elettaria cardamum White and Maton) were highly active against both Gram-negative an...

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

    Science.gov (United States)

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

    2014-01-01

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

  4. Physical Properties and Antibacterial Efficacy of Biodegradable Chitosan Films

    OpenAIRE

    中島, 照夫

    2009-01-01

    [Synopsis] Chitin, chitosan and quaternary chitosan films were prepared, and the physical properties and the antibacterial activities of chitosan and quaternary chitosan films were evaluated. The tensile strength of chitin films was 30~40% lower than that of chitosan films, but the crystallinity of chitin film was much higher than that of chitosan films. The crystallinity and orientation of crystallites were hardly affected by the four kinds of solvent chosen to cast chitosan films, but a de...

  5. Evaluation of antibacterial activity of "Mangabarana" Austroplenckia populnea Reissek (Celastraceae

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    Roqueline R. S. de Miranda

    Full Text Available Austroplenckia populnea (Mangabarana is popularly used by people from Minas Gerais, Brazil for dysenteries diseases treatment. Antitumor and antiulcer activities were also attributed to this plant. Extracts obtained using solvents of different polarities and pentacyclic triterpenes (PCTTs isolated from these extracts through phytochemical methods were submitted to antibacterial assays. The results showed the existence of this activity and open perspectives for news studies with other organic compounds isolated from this plant.

  6. Antibacterial behavior of diamond nanoparticles against Escherichia coli

    Czech Academy of Sciences Publication Activity Database

    Beranová, Jana; Seydlová, Gabriela; Kozak, Halyna; Potocký, Štěpán; Konopásek, I.; Kromka, Alexander

    2012-01-01

    Roč. 249, č. 12 (2012), s. 2581-2584 ISSN 0370-1972 R&D Projects: GA ČR GAP108/12/0910; GA ČR GPP205/12/P331; GA MŠk LH12186 Institutional research plan: CEZ:AV0Z10100521 Keywords : antibacterial properties * diamond nanoparticles * FTIR spectroscopy * Raman spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.489, year: 2012

  7. Synthesis and Antibacterial Screening of Novel Derivatives of Embelin

    Science.gov (United States)

    Subramanian, L.; Leema, M.; Pradeep, N. S.; Joy, B.; Pillai, Z. S.

    2018-02-01

    Embelin, a naturally occurring compound extracted from Embelia ribes is used in Ayurvedic system of medicine owing to its wide spectrum of biological activities. In the present work, we have aimed at improving the efficacy of Embelin by appropriate structural modifications. A few novel derivatives of Embelin have been prepared. The antibacterial screening of these derivatives were carried out and compared with a well known antibiotic, Streptomycin. The derivatives exhibited better activity than Streptomycin and the lead molecule, Embelin.

  8. Nanofilms of hyaluronan/chitosan assembled layer-by-layer: An antibacterial surface for Xylella fastidiosa.

    Science.gov (United States)

    Hernández-Montelongo, Jacobo; Nascimento, Vicente F; Murillo, Duber; Taketa, Thiago B; Sahoo, Prasana; de Souza, Alessandra A; Beppu, Marisa M; Cotta, Monica A

    2016-01-20

    In this work, nanofilms of hyaluronan/chitosan (HA/CHI) assembled layer by layer were synthesized; their application as a potential antimicrobial material was demonstrated for the phytopathogen Xylella fastidiosa, a gram-negative bacterium, here used as a model. For the synthesis, the influence of pH and ionic strength of these natural polymer stem-solutions on final characteristics of the HA/CHI nanofilms was studied in detail. The antibacterial effect was evaluated using widefield fluorescence microscopy. These results were correlated with the chemical properties of the nanofilms, studied by FTIR and Raman spectroscopy, as well as with their morphology and surface properties characterized using SEM and AFM. The present findings can be extended to design and optimize HA/CHI nanofilms with enhanced antimicrobial behavior for other type of phytopathogenic gram-negative bacteria species, such as Xanthomonas citri, Xanthomas campestri and Ralstonia solanacearum. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Electrospun polycaprolactone nanofibres decorated by drug loaded chitosan nano-reservoirs for antibacterial treatments

    Science.gov (United States)

    Guarino, Vincenzo; Cruz-Maya, Iriczalli; Altobelli, Rosaria; Khodir, W. K. Abdul; Ambrosio, Luigi; Alvarez Pèrez, Marco A.; Almaguer Flores, Argelia

    2017-12-01

    The main limitation of conventional antibiotic therapies concerns the low efficacy to fight bacteria attacks during long treatment times. In this context, the integrated use of electrofluidodynamics (EFDs)—basically electrospinning and electrospraying—may represent an interesting route for designing nanostructured platforms with controlled release to prevent the formation of bacterial biofilms in oral implant sites. They allow for the deposition of nanofibres and nanoparticles by different modes—i.e. sequential, simultaneous—for the fabrication of more efficacious systems in terms of degradation protection, pharmacokinetic control and drug distribution to the surrounding tissues. Herein, we will investigate EFDs processing modes and conditions to decorate polycaprolactone nanofibres surfaces by chitosan nano-reservoirs for the administration of Amoxicillin Trihydrate as an innovative antibacterial treatment of the periodontal pocket.

  10. Exchangeable Ions Are Responsible for the In Vitro Antibacterial Properties of Natural Clay Mixtures

    Science.gov (United States)

    Otto, Caitlin C.; Haydel, Shelley E.

    2013-01-01

    We have identified a natural clay mixture that exhibits in vitro antibacterial activity against a broad spectrum of bacterial pathogens. We collected four samples from the same source and demonstrated through antibacterial susceptibility testing that these clay mixtures have markedly different antibacterial activity against Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA). Here, we used X-ray diffraction (XRD) and inductively coupled plasma – optical emission spectroscopy (ICP-OES) and – mass spectrometry (ICP-MS) to characterize the mineralogical and chemical features of the four clay mixture samples. XRD analyses of the clay mixtures revealed minor mineralogical differences between the four samples. However, ICP analyses demonstrated that the concentrations of many elements, Fe, Co, Cu, Ni, and Zn, in particular, vary greatly across the four clay mixture leachates. Supplementation of a non-antibacterial leachate containing lower concentrations of Fe, Co, Ni, Cu, and Zn to final ion concentrations and a pH equivalent to that of the antibacterial leachate generated antibacterial activity against E. coli and MRSA, confirming the role of these ions in the antibacterial clay mixture leachates. Speciation modeling revealed increased concentrations of soluble Cu2+ and Fe2+ in the antibacterial leachates, compared to the non-antibacterial leachates, suggesting these ionic species specifically are modulating the antibacterial activity of the leachates. Finally, linear regression analyses comparing the log10 reduction in bacterial viability to the concentration of individual ion species revealed positive correlations with Zn2+ and Cu2+ and antibacterial activity, a negative correlation with Fe3+, and no correlation with pH. Together, these analyses further indicate that the ion concentration of specific species (Fe2+, Cu2+, and Zn2+) are responsible for antibacterial activity and that killing activity is not solely attributed to pH. PMID:23691149

  11. Expression of antibacterial resistance at the site of a delayed hypersensitivity reaction.

    OpenAIRE

    Patel, P J

    1980-01-01

    The site of a delayed hypersensitivity reaction to tuberculin or bovine serum ablumin was shown to contain mechanisms that expressed increased antibacterial activity, as evidenced by restricted growth of a local inoculum of Listeria monocytogenes. As was the case with a delayed hypersensitivity reaction, the local generation of antibacterial activity was antigen specific and T-cell dependent. Antibacterial resistance was always expressed at the site of injection of specific antigen in sensiti...

  12. Synergistic Antibacterial Activity of the Essential Oil of Aguaribay (Schinus molle L.)

    OpenAIRE

    Rocha, Pedro; Rodilla, Jesus; Díez, David; Elder, Heriberto; Guala, Maria; Silva, Lúcia; Pombo, Eunice

    2012-01-01

    Schinus molle L. (aguaribay, aroeira-falsa, “molle”, family Anacardiaceae), a native of South America, produces an active antibacterial essential oil extracted from the leaves and fruits. This work reports a complete study of its chemical composition and determines the antibacterial activity of Schinus molle L. essential oil and its main components. The results showed that the crude extract essential oil has a potent antibacterial effect on Staphylococcus aureus ATCC 25923...

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

    Directory of Open Access Journals (Sweden)

    LEXTER R. NATIVIDAD

    2014-02-01

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

  14. Antibacterial activity, surface roughness, flexural strength, and solubility of conventional luting cements containing chlorhexidine diacetate/cetrimide mixtures.

    Science.gov (United States)

    Korkmaz, Fatih Mehmet; Tüzüner, Tamer; Baygin, Ozgul; Buruk, Celal Kurtulus; Durkan, Rukiye; Bagis, Bora

    2013-08-01

    The failure of fixed dental restorations is commonly associated with caries. The use of conventional luting cements containing antibacterial agents may overcome this problem. The purpose of this study was to evaluate the antibacterial activity (ABA), surface roughness (Ra), flexural strength (FS), and solubility (SL) patterns of the conventional dental luting cements zinc phosphate (ZP), zinc polycarboxylate (PC), and glass ionomer (GIC) after the addition of 5% chlorhexidine diacetate/cetrimide (CHX+CT). Antibacterial agents with a total concentration of 5% (2.5% CHX+2.5% CT) were added to antibacterial agent-free conventional luting cement powders (ZPC, PCC, and GICC) and designated as experimental groups (ZPE, PCE, and GICE). ABA against Streptococcus mutans (SM) and Lactobacillus casei (LB) was examined by using the agar diffusion test method. Ra, FS, and SL values were obtained after storage in distilled water at 37°C for 24 hours. The Kruskal-Wallis and Mann Whitney U with Bonferroni correction tests were used to test for agar diffusion (α=.05) and 2-way ANOVA and Fisher Least Significant Difference (LSD) test were used to measure Ra, FS, and SL (α=.05). The control groups exhibited limited ABA. With the exception of PCE>PCC on day 1 for SM, all experimental groups showed significantly greater and longer-lasting protection against SM and LB bacteria for up to 180 days than their controls (PZPE; P>.05, PCC>PCE; PGICC (P>.05) when compared with their individual controls. Control groups exhibited higher FS values than did the experimental groups (ZPC>ZPE; PPCE; PGICE; P>.05). The experimental groups exhibited higher solubilities than did their controls in the ZPC (P>.05) and GICC groups (P<.05) but were lower in PCC group (P<.05). Incorporating a 5% CHX+CT mixture into conventional dental luting cements and altering their Ra, FS, and SL values may provide greater antibacterial protection against SM and LB. Copyright © 2013 The Editorial Council of the

  15. Microstructure and cytotoxicity evaluation of duplex-treated silver-containing antibacterial TiO{sub 2} coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiangyu; Wu, Haibo; Geng, Zhenhua; Huang, Xiaobo; Hang, Ruiqiang; Ma, Yong; Yao, Xiaohong; Tang, Bin, E-mail: tangbin6405@sina.com

    2014-12-01

    Implant-related infection is one of the most common and serious complications associated with biomedical implantation. To prevent bacterial adhesion, a series of porous TiO{sub 2} coatings with different concentrations of silver (designated as M0, M1, M2 and M3) were prepared on pure titanium substrates by a duplex-treatment technique combining magnetron sputtering with micro-arc oxidation. All coatings are porous with pore size less than 5 μm and the concentrations of silver in the M0, M1, M2 and M3 are 0, 0.95, 1.36 and 1.93 wt.%, respectively. Silver is found to be distributed throughout the thickness of the coatings by scanning electron microscopy. The release of silver from the TiO{sub 2} coatings was confirmed by an inductively-coupled plasma mass spectroscopy. The antibacterial effects of these coatings were tested against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli), and the cytotoxicity was evaluated using the mouse pre-osteoblast cells. The results indicate that the antibacterial activities of TiO{sub 2} coatings are greatly improved due to the incorporation of silver. No cytotoxic effect is found for the M1 surfaces from the observation of pre-osteoblast cell by MTT assay and fluorescence microscopy. Although the M2 and M3 coatings appeared to be toxic for pre-osteoblast cells after 1 day in culture, the cell viability on M2 and M3 surfaces was greatly raised after culturing for 2 days. Our results suggested that the TiO{sub 2} coatings incorporated with an optimum amount of silver can possess excellent antibacterial activities without cytotoxic effect, which has promising applications in biomedical devices. - Highlights: • Porous TiO{sub 2} coatings with various concentration of Ag on titanium were prepared. • Ag element was distributed throughout the thickness of the coatings. • The antibacterial activities were greatly improved due to the incorporation of Ag. • The release amounts of Ag were

  16. Microstructure and cytotoxicity evaluation of duplex-treated silver-containing antibacterial TiO2 coatings

    International Nuclear Information System (INIS)

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

    2014-01-01

    Implant-related infection is one of the most common and serious complications associated with biomedical implantation. To prevent bacterial adhesion, a series of porous TiO 2 coatings with different concentrations of silver (designated as M0, M1, M2 and M3) were prepared on pure titanium substrates by a duplex-treatment technique combining magnetron sputtering with micro-arc oxidation. All coatings are porous with pore size less than 5 μm and the concentrations of silver in the M0, M1, M2 and M3 are 0, 0.95, 1.36 and 1.93 wt.%, respectively. Silver is found to be distributed throughout the thickness of the coatings by scanning electron microscopy. The release of silver from the TiO 2 coatings was confirmed by an inductively-coupled plasma mass spectroscopy. The antibacterial effects of these coatings were tested against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli), and the cytotoxicity was evaluated using the mouse pre-osteoblast cells. The results indicate that the antibacterial activities of TiO 2 coatings are greatly improved due to the incorporation of silver. No cytotoxic effect is found for the M1 surfaces from the observation of pre-osteoblast cell by MTT assay and fluorescence microscopy. Although the M2 and M3 coatings appeared to be toxic for pre-osteoblast cells after 1 day in culture, the cell viability on M2 and M3 surfaces was greatly raised after culturing for 2 days. Our results suggested that the TiO 2 coatings incorporated with an optimum amount of silver can possess excellent antibacterial activities without cytotoxic effect, which has promising applications in biomedical devices. - Highlights: • Porous TiO 2 coatings with various concentration of Ag on titanium were prepared. • Ag element was distributed throughout the thickness of the coatings. • The antibacterial activities were greatly improved due to the incorporation of Ag. • The release amounts of Ag were initially high and gradually

  17. Preparation, characterization and antibacterial activity of oxidized κ-carrageenan.

    Science.gov (United States)

    Zhu, Mingjin; Ge, Liming; Lyu, Yongbo; Zi, Yaxin; Li, Xinying; Li, Defu; Mu, Changdao

    2017-10-15

    The oxidized κ-carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ-carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ-carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ-carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ-carrageenans against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) was systematically investigated. The results showed that the oxidized κ-carrageenan could damage the bacterial cell wall and cytoplasmic membrane and suppress the growth of both Gram-positive and Gram-negative bacteria. The oxidized κ-carrageenan possessed broad-spectrum antibacterial activity, which may be used as a new antibacterial agent. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Antifungal and Antibacterial Metabolites from a French Poplar Type Propolis

    Directory of Open Access Journals (Sweden)

    Séverine Boisard

    2015-01-01

    Full Text Available During this study, the in vitro antifungal and antibacterial activities of different extracts (aqueous and organic obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains: Candida albicans, C. glabrata, and Aspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains including Staphylococcus aureus. Organic extracts showed a significant antifungal activity against C. albicans and C. glabrata (MIC80 between 16 and 31 µg/mL but only a weak activity towards A. fumigatus (MIC80 = 250 µg/mL. DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially against S. aureus (SA and several of its methicillin-resistant (MRSA and methicillin-susceptible (MSSA strains (MIC100 30–97 µg/mL. A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.

  19. Study on antibacterial activity of hydrogel from irradiated silk protein

    International Nuclear Information System (INIS)

    Bunnak, J.; Chaisupakitsin, M.

    2001-01-01

    Hydrogels for biomedical application were prepared from solution blends of 3% silk protein and 3%, 10% poly (vinyl alcohol) (PVA) and followed with irradiation. Mixture of hydrogels were gamma irradiated at 10, 20, 30, 40 and 50 kGy under N 2 atmosphere. To clarify anti-bacterial activity of hydrogels, modified of the Agar disk diffusion method and American Association of Textile Chemists and Colorists, AATCC Test Method 90-1977, were carried out. The four kinds of bacteria such as Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis, were used. It was found that a 1:3 volume ratio of 3% silk protein and 3% PVA respectively, at 50 kGy irradiation, is suitable conditions for preparation hydrogels and trend to indicate the highest of an antibacterial activity against E. coli, B. subtilis and S. aureus. However the antibacterial activity of hydrogels against S. epidermidis was not clearly. These results are very useful to expand the application of hydrogel from irradiated silk protein to the medical products. (author)

  20. Prediction of antibacterial activity from physicochemical properties of antimicrobial peptides.

    Directory of Open Access Journals (Sweden)

    Manuel N Melo

    Full Text Available Consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. Studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible correlation of these with the in vivo onset of activity have only recently been proposed. In addition, such thresholds observed in model membranes occur at local peptide concentrations close to full membrane coverage. In this work we fully develop an interaction model of antimicrobial peptides with biological membranes; by exploring the consequences of the underlying partition formalism we arrive at a relationship that provides antibacterial activity prediction from two biophysical parameters: the affinity of the peptide to the membrane and the critical bound peptide to lipid ratio. A straightforward and robust method to implement this relationship, with potential application to high-throughput screening approaches, is presented and tested. In addition, disruptive thresholds in model membranes and the onset of antibacterial peptide activity are shown to occur over the same range of locally bound peptide concentrations (10 to 100 mM, which conciliates the two types of observations.

  1. Antibacterial Action of Curcumin against Staphylococcus aureus: A Brief Review

    Directory of Open Access Journals (Sweden)

    Sin-Yeang Teow

    2016-01-01

    Full Text Available Curcumin, the major constituent of Curcuma longa L. (Zingiberaceae family or turmeric, commonly used for cooking in Asian cuisine, is known to possess a broad range of pharmacological properties at relatively nontoxic doses. Curcumin is found to be effective against Staphylococcus aureus (S. aureus. As demonstrated by in vitro experiment, curcumin exerts even more potent effects when used in combination with various other antibacterial agents. Hence, curcumin which is a natural product derived from plant is believed to have profound medicinal benefits and could be potentially developed into a naturally derived antibiotic in the future. However, there are several noteworthy challenges in the development of curcumin as a medicine. S. aureus infections, particularly those caused by the multidrug-resistant strains, have emerged as a global health issue and urgent action is needed. This review focuses on the antibacterial activities of curcumin against both methicillin-sensitive S. aureus (MSSA and methicillin-resistant S. aureus (MRSA. We also attempt to highlight the potential challenges in the effort of developing curcumin into a therapeutic antibacterial agent.

  2. Ag/C:F Antibacterial and hydrophobic nanocomposite coatings

    Science.gov (United States)

    Kylián, Ondřej; Kratochvíl, Jiří; Petr, Martin; Kuzminova, Anna; Slavínská, Danka; Biederman, Hynek; Beranová, Jana

    Silver-based nanomaterials that exhibit antibacterial character are intensively studied as they represent promising weapon against multi-drug resistant bacteria. Equally important class of materials represent coatings that have highly water repellent nature. Such materials may be used for fabrication of anti-fogging or self-cleaning surfaces. The aim of this study is to combine both of these valuable material characteristics. Antibacterial and highly hydrophobic Ag/C:F nanocomposite films were fabricated by means of gas aggregation source of Ag nanoparticles and sputter deposition of C:F matrix. The nanocomposite coatings had three-layer structure C:F base layer/Ag nanoparticles/C:F top layer. It is shown that the increasing number of Ag nanoparticles in produced coatings leads not only in enhancement of their antibacterial activity, but also causes substantial increase of their hydrophobicity. Under optimized conditions, the coatings are super-hydrophobic with water contact angle equal to 165∘ and are capable to induce 6-log reduction of bacteria presented in solution within 4h.

  3. Antibacterial and antifungal effects of essential oils from coniferous trees.

    Science.gov (United States)

    Hong, Eui-Ju; Na, Ki-Jeung; Choi, In-Gyu; Choi, Kyung-Chul; Jeung, Eui-Bae

    2004-06-01

    Essential oils have potential biological effects, i.e., antibiotic, anticarcinogenic, and sedative effects during stress. In the present study, we investigated the antibacterial and antifungal effects of essential oils extracted from the coniferous species Pinus densiflora, Pinus koraiensis, and Chamaecyparis obtusa, because their biological activities have not been yet elucidated. The essential oils were quantified using gas chromatography and identified in gas chromatography-mass spectrometric analysis. Simultaneously, antibacterial and antifungal assays were performed using the essential oils distilled from the needles of coniferous trees. The major components and the percentage of each essential oil were: 19.33% beta-thujene in P. densiflora; 10.49% alpha-pinene in P. koraiensis; 10.88% bornyl acetate in C. obtusa. The essential oils from P. densiflora and C. obtusa have antibacterial effects, whereas essential oils from P. koraiensis and C. obtusa have antifungal effects. These results indicate that the essential oils from the three coniferous trees, which have mild antimicrobial properties, can inhibit the growth of gram-positive and gram-negative bacteria and fungi.

  4. Current Technology in the Discovery and Development of Novel Antibacterials.

    Science.gov (United States)

    Chung, Pooi Yin

    2018-01-01

    Bacterial resistance to antibiotics is one of the most serious challenge to global public health. The introduction of new antibiotics in clinical settings, i.e. agents that belong to a new class of antibacterials, act on new targets or has a novel mechanisms of action, may not be sufficient to cope with the emergence of multidrug-resistant pathogens such as Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii and Escherichia coli, which are increasingly prevalent in healthcare settings in Europe, the USA and Asia. Hence, coordinated efforts in minimizing the risk of spread of resistant bacteria and renewing research efforts in the search for novel antibacterial agents are urgently needed to manage this global crisis. This review highlights the challenges and potential in using current technologies in the discovery and development of novel antibacterial agents to keep up with the constantly evolving resistance in bacteria. With the explosion of bacterial genomic data and rapid development of new sequencing technologies, the understanding of bacterial pathogenesis and identification of novel antibiotic targets have significantly improved. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Antibacterial activity and toxicity of silver - nanosilver versus ionic silver

    International Nuclear Information System (INIS)

    Kvitek, L; Panacek, A; Prucek, R; Soukupova, J; Vanickova, M; Zboril, R; Kolar, M

    2011-01-01

    The in vitro study of antibacterial activity of silver nanoparticles (NPs), prepared via modified Tollens process, revealed high antibacterial activity even at very low concentrations around several units of mg/L. These concentrations are comparable with concentrations of ionic silver revealing same antibacterial effect. However, such low concentrations of silver NPs did not show acute cytotoxicity to mammalian cells - this occurs at concentrations higher than 60 mg/L of silver, while the cytotoxic level of ionic silver is much more lower (approx. 1 mg/L). Moreover, the silver NPs exhibit lower acute ecotoxicity against the eukaryotic organisms such as Paramecium caudatum, Monoraphidium sp. and D. melanogaster. The silver NPs are toxic to these organisms at the concentrations higher than 30 mg/L of silver. On contrary, ionic silver retains its cytoxicity and ecotoxicity even at the concentration equal to 1 mg/L. The performed experiments demonstrate significantly lower toxicity of silver NPs against the eukaryotic organisms than against the prokaryotic organisms.

  6. Antibacterial activity and toxicity of silver - nanosilver versus ionic silver

    Energy Technology Data Exchange (ETDEWEB)

    Kvitek, L; Panacek, A; Prucek, R; Soukupova, J; Vanickova, M; Zboril, R [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17. Listopadu 12, 77146 Olomouc (Czech Republic); Kolar, M, E-mail: ales.panacek@upol.cz [Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University, Hnevotinska 3, 77520 Olomouc (Czech Republic)

    2011-07-06

    The in vitro study of antibacterial activity of silver nanoparticles (NPs), prepared via modified Tollens process, revealed high antibacterial activity even at very low concentrations around several units of mg/L. These concentrations are comparable with concentrations of ionic silver revealing same antibacterial effect. However, such low concentrations of silver NPs did not show acute cytotoxicity to mammalian cells - this occurs at concentrations higher than 60 mg/L of silver, while the cytotoxic level of ionic silver is much more lower (approx. 1 mg/L). Moreover, the silver NPs exhibit lower acute ecotoxicity against the eukaryotic organisms such as Paramecium caudatum, Monoraphidium sp. and D. melanogaster. The silver NPs are toxic to these organisms at the concentrations higher than 30 mg/L of silver. On contrary, ionic silver retains its cytoxicity and ecotoxicity even at the concentration equal to 1 mg/L. The performed experiments demonstrate significantly lower toxicity of silver NPs against the eukaryotic organisms than against the prokaryotic organisms.

  7. Antibacterial activity of silver nanoparticles synthesized from serine

    Energy Technology Data Exchange (ETDEWEB)

    Jayaprakash, N. [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College, Chennai 600 034 (India); SRM Valliammai Engineering College, Department of Chemistry, Chennai 603 203 (India); Judith Vijaya, J., E-mail: jjvijayaloyola@yahoo.co.in [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College, Chennai 600 034 (India); John Kennedy, L. [Materials Division, School of Advanced Sciences, VIT University, Chennai Campus, Chennai 600 048 (India); Priadharsini, K.; Palani, P. [Department of Center for Advanced Study in Botany, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2015-04-01

    Silver nanoparticles (Ag NPs) were synthesized by a simple microwave irradiation method using polyvinyl pyrrolidone (PVP) as a capping agent and serine as a reducing agent. UV–Visible spectra were used to confirm the formation of Ag NPs by observing the surface plasmon resonance (SPR) band at 443 nm. The emission spectrum of Ag NPs showed an emission band at 484 nm. In the presence of microwave radiation, serine acts as a reducing agent, which was confirmed by Fourier transformed infrared (FT-IR) spectrum. High-resolution transmission electron microscopy (HR-TEM) and high-resolution scanning electron microscopy (HR-SEM) were used to investigate the morphology of the synthesized sample. These images showed the sphere-like morphology. The elemental composition of the sample was determined by the energy dispersive X-ray analysis (EDX). Selected area electron diffraction (SAED) was used to find the crystalline nature of the Ag NPs. The electrochemical behavior of the synthesized Ag NPs was analyzed by the cyclic voltammetry (CV). Antibacterial experiments showed that the prepared Ag NPs showed relatively similar antibacterial activities, when compared with AgNO{sub 3} against Gram-positive and Gram-negative bacteria. - Highlights: • Microwave irradiation method is used to synthesize silver nanoparticles. • Highly stable silver nanoparticles are produced from serine. • A detailed study of antibacterial activities is discussed. • Formation mechanism of silver microspheres has been proposed.

  8. Fabrication of silver nanoparticle sponge leather with durable antibacterial property.

    Science.gov (United States)

    Liu, Gongyan; Haiqi, Gao; Li, Kaijun; Xiang, Jun; Lan, Tianxiang; Zhang, Zongcai

    2018-03-15

    Leather product with durable antibacterial property is of great interest both from industry and consumer's point of view. To fabricate such functional leather, gallic acid modified silver nanoparticles (GA@AgNPs) were first in situ synthesized with a core-shell structure and an average size of 15.3nm. Due to its hydrophilic gallic acid surface, the GA@AgNPs possessed excellent stability and dispersibility in wide pH range from 3 to 12 and also showed effective antibacterial activity with a minimum inhibitory concentration (MIC) of around 10μgmL -1 . Then, such GA@AgNPs were used as retanning agent to be successfully filled into leather matrix during the leather manufacturing process. Moreover, taking the advantage of its high surface density of carboxyl groups, these GA@AgNPs could be further chemically cross-linked onto collagen fibers by chrome tanning agent. After retanning, the resultant leather was given a "AgNPs sponge" feature with high payload of silver nanoparticles against laundry, exhibiting high and durable antibacterial activity. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Antioxidant and antibacterial properties of the Melissa officinalis essential oil

    Directory of Open Access Journals (Sweden)

    R. Mahmodi

    2016-06-01

    Full Text Available Background: Increasing drug resistance in microorganisms and concerns for side effects of chemical preservatives, especially in the food industry, have led to extensive studies on novel potential agents with natural origin. Objective: The aim of this study was to determine the antioxidant and antibacterial properties of the Melissa officinalis essential oil. Methods: This experimental study was carried out at Islamic Azad University, Saveh Branch in 2012-2013. The essential oil was extracted from different parts of the plant (leaves, stem and flower by hydrodistillation. The essential oil was phytochemically characterized by gas chromatography-mass spectrometry (GC-MS analysis. Antibacterial properties were examined by disc diffusion and microtiter plates. Antioxidant activity was examined by diphenyl-picryl-hydrazyl (DPPH assay. Findings: E-Citral in leaves, 2-Cyclohexen-1-one, 2-methyl-5-(1-methylethenyl in stem, and Trans-Carveol in flower were the major components identified in the Melissa officinalis. Among different parts essential oil, the highest and the lowest antibacterial activity were related to leaves and stem, respectively. The largest diameter of the inhibition growth zone for Staphylococcus aureus and Pseudomonas aeruginosa was related to the leaves essential oil. The highest antioxidant activity was related to the leaves essential oil in DPPH assay. Conclusion: With regards to the results, the Melissa officinalis essential oil can be used as a natural preservative for increasing the shelf life of foods.

  10. Antibacterial activity of Thai herbal extracts on acne involved microorganism.

    Science.gov (United States)

    Niyomkam, P; Kaewbumrung, S; Kaewnpparat, S; Panichayupakaranant, P

    2010-04-01

    Ethyl acetate and methanol extracts of 18 Thai medicinal plants were investigated for their antibacterial activity against Propionibacterium acnes, Stapylococcus aureus, and S. epidermidis. Thirteen plant extracts were capable of inhibiting the growth of P. acnes and S. epidermidis, while 14 plant extracts exhibited an inhibitory effect on S. aureus. Based on the broth dilution method, the ethyl acetate extract of Alpinia galanga (L.) Wild. (Zingiberaceae) rhizome showed the strongest antibacterial effect against P. acnes, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 156.0 and 312.0 microg/mL, respectively. On the basis of bioassay-guided purification, the ethyl acetate extract was isolated to afford the antibacterial active compound, which was identified as 1'-acetoxychavicol acetate (1'-ACA). 1'-ACA had a strong inhibitory effect on P. acnes with MIC and MBC values of 62.0 and 250.0 microg/mL, respectively. Thus, 1'-ACA was used as an indicative marker for standardization of A. galanga extract using high performance liquid chromatography. These results suggest that A. galanga extract could be an interesting agent for further studies on an alternative treatment of acne.

  11. In Vitro Biocompatibility of Endodontic Sealers Incorporating Antibacterial Nanoparticles

    Directory of Open Access Journals (Sweden)

    Itzhak Abramovitz

    2012-01-01

    Full Text Available The main cause of endodontic disease is bacteria. Disinfection is presently achieved by cleaning the root canal system prior to obturation. Following setting, root canal filling is devoid of any antibacterial effect. Endodontic sealers with antimicrobial properties yet biocompatible may enhance root canal therapy. For this purpose, quaternized polyethylenimine nanoparticles which are antibacterial polymers, biocompatible, nonvolatile, and stable may be used. The aim of the present study was to examine the impact of added QPEI on the cytotoxicity of AH Plus, Epiphany, and GuttaFlow endodontic sealers. The effect of these sealers on the proliferation of RAW 264.7 macrophage and L-929 fibroblast cell lines and on the production of TNFα from macrophages was examined. Cell vitality was evaluated using a colorimetric XTT assay. The presence of cytokines was determined by two-site ELISA. Results show that QPEI at 1% concentration does not impair the basic properties of the examined sealers in both macrophages and fibroblast cell lines. Incorporation of 1% QPEI into the sealers did not impair their biocompatibility. QPEI is a potential clinical candidate to improve antibacterial activity of sealers without increasing cytotoxicity.

  12. Recyclable magnetite-silver heterodimer nanocomposites with durable antibacterial performance

    Directory of Open Access Journals (Sweden)

    Chunyan Yong

    2018-03-01

    Full Text Available There is a significant need for magnetite-silver nanocomposites that exhibit durable and recyclable antimicrobial activity. In this study, magnetic iron oxide nanoparticles (Fe3O4 NPs coated with ethylenediamine-modified chitosan/polyacrylic acid copolymeric layer (Fe3O4@ECS/PAA were fabricated. Subsequently, directly deposited silver (Ag NPs procedure was carried out to form the antibacterial heterodimers of Fe3O4@ECS/PAA-Ag NPs. The composition and morphology of the resultant nanostructures were confirmed by FT-IR, XRD, TEM and TGA. The overall length of the heterodimers was approximately 45 nm, in which the mean diameter of Fe3O4@ECS/PAA NPs reached up to 35 nm, and that of Ag NPs was around 15 nm. The mass fraction of silver NPs in the nanocomposites was about 63.1%. The obtained Fe3O4@ECS/PAA NPs exhibited good colloidal stability, and excellent response to additional magnetic field, making the NPs easy to recover after antibacterial tests. In particular, the Fe3O4@ECS/PAA-Ag NPs retained nearly 100% biocidal efficiency (106–107 CFU/mg nanoparticles for both Gram-negative bacteria E. coli and Gram-positive bacteria S. aureus throughout ten cycles without washing with any solvents or water, exhibiting potent and durable antibacterial activity.

  13. Shrink-Induced Superhydrophobic and Antibacterial Surfaces in Consumer Plastics

    Science.gov (United States)

    Freschauf, Lauren R.; McLane, Jolie; Sharma, Himanshu; Khine, Michelle

    2012-01-01

    Structurally modified superhydrophobic surfaces have become particularly desirable as stable antibacterial surfaces. Because their self-cleaning and water resistant properties prohibit bacteria growth, structurally modified superhydrophobic surfaces obviate bacterial resistance common with chemical agents, and therefore a robust and stable means to prevent bacteria growth is possible. In this study, we present a rapid fabrication method for creating such superhydrophobic surfaces in consumer hard plastic materials with resulting antibacterial effects. To replace complex fabrication materials and techniques, the initial mold is made with commodity shrink-wrap film and is compatible with large plastic roll-to-roll manufacturing and scale-up techniques. This method involves a purely structural modification free of chemical additives leading to its inherent consistency over time and successive recasting from the same molds. Finally, antibacterial properties are demonstrated in polystyrene (PS), polycarbonate (PC), and polyethylene (PE) by demonstrating the prevention of gram-negative Escherichia coli (E. coli) bacteria growth on our structured plastic surfaces. PMID:22916100

  14. Honey Antibacterial Effect Boosting Using Origanum vulgare L. Essential Oil.

    Science.gov (United States)

    Imtara, Hamada; Elamine, Youssef; Lyoussi, Badiâa

    2018-01-01

    The appearance of new bacterial strains which cause pathogenic diseases and which are resistant to the most used antibiotics requires probing new antibacterial agents sources. Therefore, the main aim of the present work was to follow the antibacterial activity of honey samples from Palestine and Morocco, after the combination with Origanum vulgare L. essential oil, and figure out whether the honey physicochemical parameters and geographic origin influence the final activity. The results of this study showed good geographical discrimination between the Palestinians and Moroccan honey samples. The antioxidant and antimicrobial activities showed a significant correlation with honey color, melanoidins, and phenolic and flavonoids contents. Furthermore, the possible effect of honey physicochemical parameters on the gained antimicrobial activities was assessed using the principal component analysis (PCA). Some parameters showed a promising effect and seem to be important in the process of honey samples selection. Namely, melanoidins content, phenolic content, electrical conductivity, and mineral content were shown to be positively influencing the gained antibacterial activity after the combination with essential oil against the tested strains, although a significant negative correlation was seen with the FIC only in the case of Escherichia coli (ATB: 57).

  15. Honey Antibacterial Effect Boosting Using Origanum vulgare L. Essential Oil

    Directory of Open Access Journals (Sweden)

    Hamada Imtara

    2018-01-01

    Full Text Available The appearance of new bacterial strains which cause pathogenic diseases and which are resistant to the most used antibiotics requires probing new antibacterial agents sources. Therefore, the main aim of the present work was to follow the antibacterial activity of honey samples from Palestine and Morocco, after the combination with Origanum vulgare L. essential oil, and figure out whether the honey physicochemical parameters and geographic origin influence the final activity. The results of this study showed good geographical discrimination between the Palestinians and Moroccan honey samples. The antioxidant and antimicrobial activities showed a significant correlation with honey color, melanoidins, and phenolic and flavonoids contents. Furthermore, the possible effect of honey physicochemical parameters on the gained antimicrobial activities was assessed using the principal component analysis (PCA. Some parameters showed a promising effect and seem to be important in the process of honey samples selection. Namely, melanoidins content, phenolic content, electrical conductivity, and mineral content were shown to be positively influencing the gained antibacterial activity after the combination with essential oil against the tested strains, although a significant negative correlation was seen with the FIC only in the case of Escherichia coli (ATB: 57.

  16. Study on antibacterial activity of hydrogel from irradiated silk protein

    Energy Technology Data Exchange (ETDEWEB)

    Bunnak, J; Chaisupakitsin, M [King Mongkut' s Institute of Technology Lardkrabang, Bangkok (Thailand)

    2001-03-01

    Hydrogels for biomedical application were prepared from solution blends of 3% silk protein and 3%, 10% poly (vinyl alcohol) (PVA) and followed with irradiation. Mixture of hydrogels were gamma irradiated at 10, 20, 30, 40 and 50 kGy under N{sub 2} atmosphere. To clarify anti-bacterial activity of hydrogels, modified of the Agar disk diffusion method and American Association of Textile Chemists and Colorists, AATCC Test Method 90-1977, were carried out. The four kinds of bacteria such as Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis, were used. It was found that a 1:3 volume ratio of 3% silk protein and 3% PVA respectively, at 50 kGy irradiation, is suitable conditions for preparation hydrogels and trend to indicate the highest of an antibacterial activity against E. coli, B. subtilis and S. aureus. However the antibacterial activity of hydrogels against S. epidermidis was not clearly. These results are very useful to expand the application of hydrogel from irradiated silk protein to the medical products. (author)

  17. Investigation of antibacterial activity of cotton fabric incorporating nano silver colloid

    International Nuclear Information System (INIS)

    Ngo Vo Ke Thanh; Nguyen Thi Phuong Phong

    2009-01-01

    In this work, silver nanoparticles were prepared by polyol process with microwave heating and incorporated on cotton fabric surfaces. The antibacterial performance of the antibacterial cotton fabric was tested for different concentration of nano-sized silver colloid, contact time germs, and washing times. It was found that antibacterial activity increased with the increasing concentration of nano-sized silver colloid. The antibacterial fabric with 758 mg/kg of silver nanoparticles on surface cotton was highly effective in killing test bacteria and had excellent water resisting property.

  18. Tricyclic GyrB/ParE (TriBE inhibitors: a new class of broad-spectrum dual-targeting antibacterial agents.

    Directory of Open Access Journals (Sweden)

    Leslie W Tari

    Full Text Available Increasing resistance to every major class of antibiotics and a dearth of novel classes of antibacterial agents in development pipelines has created a dwindling reservoir of treatment options for serious bacterial infections. The bacterial type IIA topoisomerases, DNA gyrase and topoisomerase IV, are validated antibacterial drug targets with multiple prospective drug binding sites, including the catalytic site targeted by the fluoroquinolone antibiotics. However, growing resistance to fluoroquinolones, frequently mediated by mutations in the drug-binding site, is increasingly limiting the utility of this antibiotic class, prompting the search for other inhibitor classes that target different sites on the topoisomerase complexes. The highly conserved ATP-binding subunits of DNA gyrase (GyrB and topoisomerase IV (ParE have long been recognized as excellent candidates for the development of dual-targeting antibacterial agents with broad-spectrum potential. However, to date, no natural product or small molecule inhibitors targeting these sites have succeeded in the clinic, and no inhibitors of these enzymes have yet been reported with broad-spectrum antibacterial activity encompassing the majority of Gram-negative pathogens. Using structure-based drug design (SBDD, we have created a novel dual-targeting pyrimidoindole inhibitor series with exquisite potency against GyrB and ParE enzymes from a broad range of clinically important pathogens. Inhibitors from this series demonstrate potent, broad-spectrum antibacterial activity against Gram-positive and Gram-negative pathogens of clinical importance, including fluoroquinolone resistant and multidrug resistant strains. Lead compounds have been discovered with clinical potential; they are well tolerated in animals, and efficacious in Gram-negative infection models.

  19. Plasma sprayed rutile titania-nanosilver antibacterial coatings

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jinjin [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Zhao, Chengjian [National Key Laboratory of Human Factors Engineering, Department of ECLSS, China Astronaut Researching and Training Center, Beijing, 100094 (China); Zhou, Jingfang [Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, SA, 5095 (Australia); Li, Chunxia [National Key Laboratory of Human Factors Engineering, Department of ECLSS, China Astronaut Researching and Training Center, Beijing, 100094 (China); Shao, Yiran; Shi, Chao [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Zhu, Yingchun, E-mail: yzhu@mail.sic.ac.cn [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2015-11-15

    Graphical abstract: - Highlights: • TiO{sub 2}/Ag feedstock powders containing 1–10,000 ppm silver nanoparticles were double sintered and deposited by plasma spray. • TiO{sub 2}/Ag coatings were composed of pure rutile phase and homogeneously-distributed metallic silver. • TiO{sub 2}/Ag coatings with more than 10 ppm silver nanoparticles exhibited strong antibacterial activity against E. coli and S. aureus. - Abstract: Rutile titania (TiO{sub 2}) coatings have superior mechanical properties and excellent stability that make them preferential candidates for various applications. In order to prevent infection arising from bacteria, significant efforts have been focused on antibacterial TiO{sub 2} coatings. In the study, titania-nanosilver (TiO{sub 2}/Ag) coatings with five different kinds of weight percentages of silver nanoparticles (AgNPs) were prepared by plasma spray. The feedstock powders, which had a composition of rutile TiO{sub 2} powders containing 1–10,000 ppm AgNPs, were double sintered and deposited on stainless steel substrates with optimized spraying parameters. X-Ray diffraction and scanning electron microscopy were used to analysize the phase composition and surface morphology of TiO{sub 2}/Ag powders and coatings. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were employed to examine the antibacterial activity of the as-prepared coatings by bacterial counting method. The results showed that silver existed homogeneously in the TiO{sub 2}/Ag coatings and no crystalline changed happened in the TiO{sub 2} structure. The reduction ratios on the TiO{sub 2}/Ag coatings with 10 ppm AgNPs were as high as 94.8% and 95.6% for E. coli and S. aureus, respectively, and the TiO{sub 2}/Ag coatings with 100–1000 ppm AgNPs exhibited 100% bactericidal activity against E. coli and S. aureus, which indicated the TiO{sub 2}/Ag coatings with more than 10 ppm AgNPs had strong antibacterial activity. Moreover, the main factors influencing the

  20. Plasma sprayed rutile titania-nanosilver antibacterial coatings

    International Nuclear Information System (INIS)

    Gao, Jinjin; Zhao, Chengjian; Zhou, Jingfang; Li, Chunxia; Shao, Yiran; Shi, Chao; Zhu, Yingchun

    2015-01-01

    Graphical abstract: - Highlights: • TiO_2/Ag feedstock powders containing 1–10,000 ppm silver nanoparticles were double sintered and deposited by plasma spray. • TiO_2/Ag coatings were composed of pure rutile phase and homogeneously-distributed metallic silver. • TiO_2/Ag coatings with more than 10 ppm silver nanoparticles exhibited strong antibacterial activity against E. coli and S. aureus. - Abstract: Rutile titania (TiO_2) coatings have superior mechanical properties and excellent stability that make them preferential candidates for various applications. In order to prevent infection arising from bacteria, significant efforts have been focused on antibacterial TiO_2 coatings. In the study, titania-nanosilver (TiO_2/Ag) coatings with five different kinds of weight percentages of silver nanoparticles (AgNPs) were prepared by plasma spray. The feedstock powders, which had a composition of rutile TiO_2 powders containing 1–10,000 ppm AgNPs, were double sintered and deposited on stainless steel substrates with optimized spraying parameters. X-Ray diffraction and scanning electron microscopy were used to analysize the phase composition and surface morphology of TiO_2/Ag powders and coatings. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were employed to examine the antibacterial activity of the as-prepared coatings by bacterial counting method. The results showed that silver existed homogeneously in the TiO_2/Ag coatings and no crystalline changed happened in the TiO_2 structure. The reduction ratios on the TiO_2/Ag coatings with 10 ppm AgNPs were as high as 94.8% and 95.6% for E. coli and S. aureus, respectively, and the TiO_2/Ag coatings with 100–1000 ppm AgNPs exhibited 100% bactericidal activity against E. coli and S. aureus, which indicated the TiO_2/Ag coatings with more than 10 ppm AgNPs had strong antibacterial activity. Moreover, the main factors influencing the antibacterial properties of TiO_2/Ag coatings were discussed with