Deposition of antimicrobial coatings on microstereolithography-fabricated microneedles

Science.gov (United States)

Gittard, Shaun D.; Miller, Philip R.; Jin, Chunming; Martin, Timothy N.; Boehm, Ryan D.; Chisholm, Bret J.; Stafslien, Shane J.; Daniels, Justin W.; Cilz, Nicholas; Monteiro-Riviere, Nancy A.; Nasir, Adnan; Narayan, Roger J.

2011-06-01

Microneedles are small-scale needle-like projections that may be used for transdermal delivery of pharmacologic agents, including protein-containing and nucleic acid-containing agents. Commercial translation of polymeric microneedles would benefit from the use of facile and cost effective fabrication methods. In this study, visible light dynamic mask microstereolithography, a rapid prototyping technique that utilizes digital light projection for selective polymerization of a liquid resin, was used for fabrication of solid microneedle array structures out of an acrylate-based polymer. Pulsed laser deposition was used to deposit silver and zinc oxide coatings on the surfaces of the visible light dynamic mask microstereolithography-fabricated microneedle array structures. Agar diffusion studies were used to demonstrate the antimicrobial activity of the coated microneedle array structures. This study indicates that light-based technologies, including visible light dynamic mask microstereolithography and pulsed laser deposition, may be used to fabricate microneedles with antimicrobial properties for treatment of local skin infections.

Antimicrobial properties of graphene-like nanoparticles: coating effect on Staphylococcus aureus

Energy Technology Data Exchange (ETDEWEB)

Olivi, M. [Sapienza University of Rome, Department of Biology and Biotechnology (Italy); Alfè, M.; Gargiulo, V. [CNR, Institute for Research on Combustion (Italy); Valle, F. [ISMN, Institute of Nanostructured Materials (Italy); Mura, F. [Sapienza University of Rome, Department of Chemistry (Italy); Di Giosia, M.; Rapino, S. [University of Bologna, Department of Chemistry “Giacomo Ciamician” (Italy); Palleschi, C.; Uccelletti, D., E-mail: daniela.uccelletti@uniroma1.it [Sapienza University of Rome, Department of Biology and Biotechnology (Italy); Fiorito, S., E-mail: silvana.fiorito@ift.cnr.it [CNR, Institute of Translational Pharmacology (Italy)

2016-12-15

The exploitation of nanomaterials with antimicrobial properties has attracted an ever-growing interest in the recent years. Carbon-based materials, such as graphene and graphene family materials (GFMs), have gained most of the attention for application in many biomedical fields. Here, we describe the antimicrobial activity of graphene-like (GL) layers derived from the chemical demolition of carbon black, against the planktonic growth of Staphylococcus aureus cells, primary cause of hospital and community-acquired infections, often leading to bacteremia and sepsis. The inhibitory capabilities of GL layers on the formation of S. aureus biofilm are also assessed. The antimicrobial properties seem based mainly on the interaction between GL layers and bacteria surfaces. FESEM and AFM analyses suggest that the GL layers coat the cells as soon as they get in contact with them, as also indicated by the wettability of the GLs.

Antimicrobial properties of graphene-like nanoparticles: coating effect on Staphylococcus aureus

International Nuclear Information System (INIS)

Olivi, M.; Alfè, M.; Gargiulo, V.; Valle, F.; Mura, F.; Di Giosia, M.; Rapino, S.; Palleschi, C.; Uccelletti, D.; Fiorito, S.

2016-01-01

The exploitation of nanomaterials with antimicrobial properties has attracted an ever-growing interest in the recent years. Carbon-based materials, such as graphene and graphene family materials (GFMs), have gained most of the attention for application in many biomedical fields. Here, we describe the antimicrobial activity of graphene-like (GL) layers derived from the chemical demolition of carbon black, against the planktonic growth of Staphylococcus aureus cells, primary cause of hospital and community-acquired infections, often leading to bacteremia and sepsis. The inhibitory capabilities of GL layers on the formation of S. aureus biofilm are also assessed. The antimicrobial properties seem based mainly on the interaction between GL layers and bacteria surfaces. FESEM and AFM analyses suggest that the GL layers coat the cells as soon as they get in contact with them, as also indicated by the wettability of the GLs.

Antimicrobial Edible Films and Coatings for Meat and Meat Products Preservation

Directory of Open Access Journals (Sweden)

Irais Sánchez-Ortega

2014-01-01

Full Text Available Animal origin foods are widely distributed and consumed around the world due to their high nutrients availability but may also provide a suitable environment for growth of pathogenic and spoilage microorganisms. Nowadays consumers demand high quality food with an extended shelf life without chemical additives. Edible films and coatings (EFC added with natural antimicrobials are a promising preservation technology for raw and processed meats because they provide good barrier against spoilage and pathogenic microorganisms. This review gathers updated research reported over the last ten years related to antimicrobial EFC applied to meat and meat products. In addition, the films gas barrier properties contribute to extended shelf life because physicochemical changes, such as color, texture, and moisture, may be significantly minimized. The effectiveness showed by different types of antimicrobial EFC depends on meat source, polymer used, film barrier properties, target microorganism, antimicrobial substance properties, and storage conditions. The perspective of this technology includes tailoring of coating procedures to meet industry requirements and shelf life increase of meat and meat products to ensure quality and safety without changes in sensory characteristics.

Autoclaving-Derived Surface Coating with In Vitro and In Vivo Antimicrobial and Antibiofilm Efficacies.

Science.gov (United States)

Su, Yajuan; Zhi, Zelun; Gao, Qiang; Xie, Meihua; Yu, Meng; Lei, Bo; Li, Peng; Ma, Peter X

2017-03-01

Biomedical device-associated infections which engender severe threat to public health require feasible solutions. In this study, block copolymers consisting of antimicrobial, antifouling, and surface-tethering segments in one molecule are synthesized and grafted on polymeric substrates by a facile plasma/autoclave-assisted method. Hetero-bifunctional polyethylene glycol (PEG) with allyl and tosyl groups (APEG-OTs) is first prepared. PEGs with different molecular weights (1200 and 2400 Da) are employed. Polyhexamethylene guanidine (PHMG) which has excellent broad-spectrum antimicrobial activity and thermal/chemical stability, is conjugated with APEG-OTs to generate the block copolymer (APEG-PHMG). Allyl terminated PHMG (A-PHMG) without PEG segments is also synthesized by reacting PHMG with allyl glycidyl ether. The synthesized copolymers are thermal initiated by autoclaving and grafted on plasma pretreated silicone surface, forming permanently bonded bottlebrush-like coatings. Both A-PHMG and APEG 1200/2400 -PHMG coatings exhibit potent antimicrobial activity against gram-positive/negative bacteria and fungus, whereas APEG 1200/2400 -PHMG coatings show superior antifouling activity and long-term reusability to A-PHMG coating. APEG 2400 -PHMG coating demonstrates the most effective in vitro antibiofilm and protein/platelet-resistant properties, as well as excellent hemo/biocompatibility. Furthermore, APEG 2400 -PHMG greatly reduces the bacteria number with 5-log reduction in a rodent subcutaneous infection model. This rationally designed dual-functional antimicrobial and antifouling coating has great potential in combating biomedical devices/implant-associated infections. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elimination of Listeria inoculated in ready-to-eat carrots by combination of antimicrobial coating and γ-irradiation

International Nuclear Information System (INIS)

Turgis, Mélanie; Millette, Mathieu; Salmieri, Stéphane; Lacroix, Monique

2012-01-01

A combined treatment of an edible coating composed of trans-cinnamaldehyde (TCN; 0.5% p/p) with γ-irradiation was investigated against Listeria inoculated in peeled mini-carrots. First, the D 10 value (γ-irradiation dose required to eliminate 90% of the bacterial population) of TCN was evaluated under air. This treatment resulted in a 3.66-fold increase in relative bacterial radiosensitivity (RBR) as compared to the control without antimicrobial coating. Secondly, the shelf life of mini-carrots during 21 day of storage at 4 °C was studied. Antimicrobial coating containing TCN was assayed in combination with two irradiation doses (0.25 and 0.5 kGy). Results suggested that the inactive coating did not have any antimicrobial effect against Listeria while the coating containing TCN resulted in a 1.29 log reduction in carrots packed under air after 21 days of storage. Hence, these observations indicated that the combination of irradiation with antimicrobial coating played an important role in enhancing the radiosensitization of Listeria to γ-irradiation. - Highlights: ► Synergistic effect of essential oils and γ-radiation against food pathogens. ► Reducing any undesirable organoleptic impact due to high concentration of EOs. ► Potential in controlling food pathogens and food spoilage bacteria in food. ► Elimination of Listeria monocytogenes in the carrots during the storage.

Novel Bioactive Antimicrobial Lignin Containing Coatings on Titanium Obtained by Electrophoretic Deposition

Directory of Open Access Journals (Sweden)

Sanja Erakovic

2014-07-01

Full Text Available Hydroxyapatite (HAP is the most suitable biocompatible material for bone implant coatings; its brittleness, however, is a major obstacle, and the reason why research focuses on creating composites with biopolymers. Organosolv lignin (Lig is used for the production of composite coatings, and these composites were examined in this study. Titanium substrate is a key biomedical material due to its well-known properties, but infections of the implantation site still impose a serious threat. One approach to prevent infection is to improve antimicrobial properties of the coating material. Silver doped hydroxyapatite (Ag/HAP and HAP coatings on titanium were obtained by an electrophoretic deposition method in order to control deposited coating mass and morphology by varying applied voltage and deposition time. The effect of lignin on microstructure, morphology and thermal behavior of biocomposite coatings was investigated. The results showed that higher lignin concentrations protect the HAP lattice during sintering, improving coating stability. The corrosion stability was evaluated in simulated body fluid (SBF at 37 °C. Newly formed plate-shaped carbonate-HAP was detected, indicating enhanced bioactive performance. The antimicrobial efficiency of Ag/HAP/Lig was confirmed by its higher reduction of bacteria Staphylococcus aureus TL (S. aureus TL than of HAP/Lig coating. Cytotoxicity assay revealed that both coatings can be classified as non-toxic against healthy immunocompetent peripheral blood mononuclear cells (PBMC.

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

Science.gov (United States)

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

Antimicrobial peptide coatings for hydroxyapatite:Electrostatic and covalent attachment of antimicrobial peptides to surfaces

OpenAIRE

Townsend, Leigh; Williams, Richard L.; Anuforom, Olachi; Berwick, Matthew R.; Halstead, Fenella; Hughes, Erik; Stamboulis, Artemis; Oppenheim, Beryl; Gough, Julie; Grover, Liam; Scott, Robert A H; Webber, Mark; Peacock, Anna F A; Belli, Antonio; Logan, Ann

2017-01-01

The interface between implanted devices and their host tissue is complex and is often optimized for maximal integration and cell adhesion. However, this also gives a surface suitable for bacterial colonization. We have developed a novel method of modifying the surface at the material-tissue interface with an antimicrobial peptide (AMP) coating to allowcell attachment while inhibiting bacterial colonization. The technology reported here is a dual AMP coating. The dual coating consists ofAMPs c...

Antimicrobial and anti-biofilm properties of polypropylene meshes coated with metal-containing DLC thin films.

Science.gov (United States)

Cazalini, Elisa M; Miyakawa, Walter; Teodoro, Guilherme R; Sobrinho, Argemiro S S; Matieli, José E; Massi, Marcos; Koga-Ito, Cristiane Y

2017-06-01

A promising strategy to reduce nosocomial infections related to prosthetic meshes is the prevention of microbial colonization. To this aim, prosthetic meshes coated with antimicrobial thin films are proposed. Commercial polypropylene meshes were coated with metal-containing diamond-like carbon (Me-DLC) thin films by the magnetron sputtering technique. Several dissimilar metals (silver, cobalt, indium, tungsten, tin, aluminum, chromium, zinc, manganese, tantalum, and titanium) were tested and compositional analyses of each Me-DLC were performed by Rutherford backscattering spectrometry. Antimicrobial activities of the films against five microbial species (Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis) were also investigated by a modified Kirby-Bauer test. Results showed that films containing silver and cobalt have inhibited the growth of all microbial species. Tungsten-DLC, tin-DLC, aluminum-DLC, zinc-DLC, manganese-DLC, and tantalum-DLC inhibited the growth of some strains, while chromium- and titanium-DLC weakly inhibited the growth of only one tested strain. In-DLC film showed no antimicrobial activity. The effects of tungsten-DLC and cobalt-DLC on Pseudomonas aeruginosa biofilm formation were also assessed. Tungsten-DLC was able to significantly reduce biofilm formation. Overall, the experimental results in the present study have shown new approaches to coating polymeric biomaterials aiming antimicrobial effect.

Characterization and antimicrobial performance of nano silver coatings on leather materials

Directory of Open Access Journals (Sweden)

N. Lkhagvajav

2015-03-01

Full Text Available In this study, the characterization and the antimicrobial properties of nano silver (nAg coating on leather were investigated. For this purpose, turbidity, viscosity and pH of nAg solutions prepared by the sol-gel method were measured. The formation of films from these solutions was characterized according to temperature by Differential Thermal Analysis-Thermogravimetry (DTA-TG equipment. The surface morphology of treated leathers was observed using Scanning Electron Microscopy (SEM. The antimicrobial performance of nAg coatings on leather materials to the test microorganisms as Escherichia coli, Staphylococcus aureus, Candida albicans and Aspergillius niger was evaluated by the application of qualitative (Agar overlay method and quantitative (percentage of microbial reduction tests. According to qualitative test results it was found that 20 μg/cm2 and higher concentrations of nAg on the leather samples were effective against all microorganisms tested. Moreover, quantitative test results showed that leather samples treated with 20 μg/cm2 of nAg demonstrated the highest antibacterial activity against E. coli with 99.25% bacterium removal, whereas a 10 μg/cm2 concentration of nAg on leather was enough to exhibit the excellent percentage reduction against S. aureus of 99.91%. The results are promising for the use of colloidal nano silver solution on lining leather as antimicrobial coating.

Biological and immunotoxicity evaluation of antimicrobial peptide-loaded coatings using a layer-by-layer process on titanium

Science.gov (United States)

Shi, Jue; Liu, Yu; Wang, Ying; Zhang, Jing; Zhao, Shifang; Yang, Guoli

2015-11-01

The prevention and control of peri-implantitis is a challenge in dental implant surgery. Dental implants with sustained antimicrobial coating are an ideal way of preventing peri-implantitis. This study reports development of a non- immunotoxicity multilayered coating on a titanium surface that had sustained antimicrobial activity and limited early biofilm formation. In this study, the broad spectrum AMP, Tet213, was linked to collagen IV through sulfo-SMPB and has been renamed as AMPCol. The multilayer AMPCol coatings were assembled on smooth titanium surfaces using a LBL technique. Using XPS, AFM, contact angle analysis, and QCM, layer-by-layer accumulation of coating thickness was measured and increased surface wetting compared to controls was confirmed. Non-cytotoxicity to HaCaT and low erythrocyte hemolysis by the AMPCol coatings was observed. In vivo immunotoxicity assays showed IP administration of AMPCol did not effect serum immunoglobulin levels. This coating with controlled release of AMP decreased the growth of both a Gram-positive aerobe (Staphylococcus aureus) and a Gram-negative anaerobe (Porphyromonas gingivalis) up to one month. Early S. aureus biofilm formation was inhibited by the coating. The excellent long-term sustained antimicrobial activity of this multilayer coating is a potential method for preventing peri-implantitis through coated on the neck of implants before surgery.

Combinatorial materials research applied to the development of new surface coatings XIII: an investigation of polysiloxane antimicrobial coatings containing tethered quaternary ammonium salt groups.

Science.gov (United States)

Majumdar, Partha; Lee, Elizabeth; Gubbins, Nathan; Christianson, David A; Stafslien, Shane J; Daniels, Justin; Vanderwal, Lyndsi; Bahr, James; Chisholm, Bret J

2009-01-01

High-throughput biological assays were used to develop structure - antimicrobial relationships for polysiloxane coatings containing chemically bound (tethered) quaternary ammonium salt (QAS) moieties. The QAS-functional polysiloxanes were derived from solution blends of a silanol-terminated polydimethylsiloxane, a trimethoxysilane-functional QAS (QAS-TMS), and methylacetoxysilane. Since the QAS moieties provide antimicrobial activity through interaction with the microorganism cell wall, most of the compositional variables that were investigated were associated with the chemical structure of the QAS-TMS. Twenty different QAS-TMS were synthesized for the study and the antimicrobial activity of sixty unique polysiloxane coatings derived from these QAS-TMS determined toward Escherichia coli , Staphylococcus aureus , and Candida albicans . The results of the study showed that essentially all of the compositional variables significantly influenced antimicrobial activity. Surface characterization of these moisture-cured coatings using atomic force microscopy as well as water contact angle and water contact angle hysteresis measurements indicated that the compositional variables significantly affected coating surface morphology and surface chemistry. Overall, compositional variables that produced heterogeneous surface morphologies provided the highest antimicrobial activity suggesting that the antimicrobial activity was primarily derived from the relationship between coating chemical composition and self-assembly of QAS moieties at the coating/air interface. Using data modeling software, a narrow region of the compositional space was identified that provided broad-spectrum antimicrobial activity.

Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles

International Nuclear Information System (INIS)

Chong, Eui-seok; Hwang, Gi Byoung; Nho, Chu Won; Kwon, Bo Mi; Lee, Jung Eun; Seo, SungChul; Bae, Gwi-Nam; Jung, Jae Hee

2013-01-01

Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ∼ 90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens. - Graphical abstract: Variations in (a) the concentrations of major antimicrobial chemical compounds on S. flavescens nanoparticle-coated filters: kurarinone, kuraridin, and sophoraflavanone-G and (b) the inactivation rate of antimicrobial filters as a function of time.

Antimicrobial durability of air filters coated with airborne Sophora flavescens nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Chong, Eui-seok; Hwang, Gi Byoung [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Nho, Chu Won [Functional Food Center, Korea Institute of Science and Technology (KIST Gangneung Institute), Gangneung, Gangwon-do 210-340 (Korea, Republic of); Kwon, Bo Mi [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Lee, Jung Eun [Biosafety Research Team, National Institute of Environmental Research, Kyungseo-Dong, Seo-Gu, Incheon 404-170 (Korea, Republic of); Seo, SungChul [Department of Environmental Health, College of Medicine, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Bae, Gwi-Nam, E-mail: gnbae@kist.re.kr [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Jung, Jae Hee, E-mail: jaehee@kist.re.kr [Center for Environment, Health, and Welfare Research, Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

2013-02-01

Airborne biological particles containing viruses, bacteria, and/or fungi can be toxic and cause infections and allergy symptoms. Recently, natural materials such as tea tree oil and Sophora flavescens have shown promising antimicrobial activity when applied as air filter media. Although many of these studies demonstrated excellent antimicrobial efficacy, only a few of them considered external environmental effects such as the surrounding humidity, temperature, and natural degradation of chemicals, all of which can affect the antimicrobial performance of these natural materials. In this study, we investigated the antimicrobial durability of air filters containing airborne nanoparticles from S. flavescens for 5 months. Antimicrobial tests and quantitative chemical analyses were performed every 30 days. Morphological changes in the nanoparticles were also evaluated by scanning electron microscopy. The major antimicrobial compounds remained stable and active for ∼ 90 days at room temperature. After about 90 days, the quantities of major antimicrobial compounds decreased noticeably with a consequent decrease in antimicrobial activity. These results are promising for the implementation of new technologies using natural antimicrobial products and provide useful information regarding the average life expectancy of antimicrobial filters using nanoparticles of S. flavescens. - Graphical abstract: Variations in (a) the concentrations of major antimicrobial chemical compounds on S. flavescens nanoparticle-coated filters: kurarinone, kuraridin, and sophoraflavanone-G and (b) the inactivation rate of antimicrobial filters as a function of time.

Antimicrobial activity of chitosan coatings and films against Listeria monocytogenes on black radish.

Science.gov (United States)

Jovanović, Gordana D; Klaus, Anita S; Nikšić, Miomir P

2016-01-01

The antibacterial activity of chitosan coatings prepared with acetic or lactic acid, as well as of composite chitosan-gelatin films prepared with essential oils, was evaluated in fresh shredded black radish samples inoculated with Listeria monocytogenes ATCC 19115 and L. monocytogenes ATCC 19112 during seven days of storage at 4°C. The chitosan coating prepared with acetic acid showed the most effective antibacterial activity. All tested formulations of chitosan films exhibited strong antimicrobial activity on the growth of L. monocytogenes on black radish, although a higher inhibition of pathogens was achieved at higher concentrations of chitosan. The antimicrobial effect of chitosan films was even more pronounced with the addition of essential oils. Chitosan-gelatin films with thyme essential oils showed the most effective antimicrobial activity. A reduction of 2.4log10CFU/g for L. monocytogenes ATCC 19115 and 2.1log10CFU/g for L. monocytogenes ATCC 19112 was achieved in the presence of 1% chitosan film containing 0.2% of thyme essential oil after 24h of storage. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Investigation of antimicrobial activity and morphological properties of metal coated textile surfaces

International Nuclear Information System (INIS)

Aslan, Necdet; Sen, Tuba; Senturk, Kenan; Corukhlu, Turgay; Varturk, Ipek; Seker, S.; Shahidi, S.; Korachi, May; Dobrovolskiy, A.M.; Tsiolko, V.V.; Matsevich, S.V.; Keskin, S.S.

2014-01-01

The results of investigation antimicrobial and surface properties of the textiles metal coated by means of magnetron or the cleaning-deposition system, which is based on sequentially arranged DC anode layer accelerator and hollow cathode, are presented. The antimicrobial properties against bacteria E. coli and S. aureus of cotton and polyester/cotton textiles coated by Cu, Ti and Ag with the use of two different systems were examined and compared.

Mechanically stable antimicrobial chitosan-PVA-silver nanocomposite coatings deposited on titanium implants.

Science.gov (United States)

Mishra, Sandeep K; Ferreira, J M F; Kannan, S

2015-05-05

Bionanocomposite coatings with antimicrobial activity comprising polyvinyl alcohol (PVA)-capped silver nanoparticles embedded in chitosan (CS) matrix were developed by a green soft chemistry synthesis route. Colloidal sols of PVA-capped silver nanoparticles (AgNPs) were synthesized by microwave irradiating an aqueous solution comprising silver nitrate and PVA. The bionanocomposites were prepared by adding an aqueous solution of chitosan to the synthesized PVA-capped AgNPs sols in appropriate ratios. Uniform bionanocomposite coatings with different contents of PVA-capped AgNPs were deposited onto titanium substrates by "spread casting" followed by solvent evaporation. Nanoindentation and antimicrobial activity tests performed on CS and bionanocomposites revealed that the incorporation of PVA-capped AgNPs enhanced the overall functional properties of the coatings, namely their mechanical stability and bactericidal activity against Escherichia coli and Staphylococcus aureus. The coated specimens maintained their antimicrobial activity for 8h due to the slow sustained release of silver ions. The overall benefits for the relevant functional properties of the coatings were shown increase with increasing contents of PVA-capped AgNPs in the bionanocomposites. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antibacterial effect of PEO coating with silver on AA7075

Energy Technology Data Exchange (ETDEWEB)

Cerchier, P., E-mail: pietrogiovanni.cerchier@studenti.unipd.it [Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35131 Padova (Italy); Pezzato, L.; Brunelli, K. [Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35131 Padova (Italy); Dolcet, P. [Department of Chemical Science, University of Padua, INSTM, UdR Padova and ICMATE-CNR, Padova (Italy); Bartolozzi, A.; Bertani, R.; Dabalà, M. [Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35131 Padova (Italy)

2017-06-01

In this work, plasma electrolytic oxidation (PEO) coatings were produced on AA7075 using alkaline solution containing silicates compounds and silver micrometric particles in order to give to the coating an antimicrobial effect. In the optic of circular economy, silver chloride derived from the acid pre-treatment of electronic scraps was used as raw material and successively silver powders were synthesized from silver chloride solution using glucose syrup as reducing agent. The coatings were characterized by scanning electron microscope (SEM), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization test and antimicrobial tests. The results evidenced that the obtained coatings were homogenous and give to the samples higher corrosion resistance than untreated alloy. The silver particles, found both inside and outside of the pores that characterize the PEO layer, produced an efficacious antimicrobial effect both against E. coli and S. aureus. - Highlights: • Silver particles were incorporated into PEO coatings produced on aluminum alloys. • The incorporation was performed with direct addition of the particles in the electrolyte. • The particles resulted equally distributed on the samples surfaces. • The obtained coatings show antimicrobial activity with both E. coli and S. aureus. • The obtained coatings were characterized by acceptable corrosion resistance.

Antibacterial effect of PEO coating with silver on AA7075

International Nuclear Information System (INIS)

Cerchier, P.; Pezzato, L.; Brunelli, K.; Dolcet, P.; Bartolozzi, A.; Bertani, R.; Dabalà, M.

2017-01-01

In this work, plasma electrolytic oxidation (PEO) coatings were produced on AA7075 using alkaline solution containing silicates compounds and silver micrometric particles in order to give to the coating an antimicrobial effect. In the optic of circular economy, silver chloride derived from the acid pre-treatment of electronic scraps was used as raw material and successively silver powders were synthesized from silver chloride solution using glucose syrup as reducing agent. The coatings were characterized by scanning electron microscope (SEM), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization test and antimicrobial tests. The results evidenced that the obtained coatings were homogenous and give to the samples higher corrosion resistance than untreated alloy. The silver particles, found both inside and outside of the pores that characterize the PEO layer, produced an efficacious antimicrobial effect both against E. coli and S. aureus. - Highlights: • Silver particles were incorporated into PEO coatings produced on aluminum alloys. • The incorporation was performed with direct addition of the particles in the electrolyte. • The particles resulted equally distributed on the samples surfaces. • The obtained coatings show antimicrobial activity with both E. coli and S. aureus. • The obtained coatings were characterized by acceptable corrosion resistance.

Antimicrobial characterization of silver nanoparticle-coated surfaces by “touch test” method

Directory of Open Access Journals (Sweden)

Gunell M

2017-11-01

Full Text Available Marianne Gunell,1,2 Janne Haapanen,3 Kofi J Brobbey,4 Jarkko J Saarinen,4 Martti Toivakka,4 Jyrki M Mäkelä,3 Pentti Huovinen,1 Erkki Eerola1,2 1Department of Medical Microbiology and Immunology, University of Turku, 2Department of Clinical Microbiology and Immunology, Microbiology and Genetics Service Area, Turku University Hospital, Turku, 3Aerosol Physics Laboratory, Department of Physics, Tampere University of Technology, Tampere, 4Laboratory of Paper Coating and Converting, Center for Functional Materials, Åbo Akademi University, Turku, Finland Abstract: Bacterial infections, especially by antimicrobial resistant (AMR bacteria, are an increasing problem worldwide. AMR is especially a problem with health care-associated infections due to bacteria in hospital environments being easily transferred from patient to patient and from patient to environment, and thus, solutions to prevent bacterial transmission are needed. Hand washing is an effective tool for preventing bacterial infections, but other approaches such as nanoparticle-coated surfaces are also needed. In the current study, direct and indirect liquid flame spray (LFS method was used to produce silver nanoparticle-coated surfaces. The antimicrobial properties of these nanoparticle surfaces were evaluated with the “touch test” method against Escherichia coli and Staphylococcus aureus. It was shown in this study that in glass samples one silver nanoparticle-coating cycle can inhibit E. coli growth, whereas at least two coating cycles were needed to inhibit S. aureus growth. Silver nanoparticle-coated polyethylene (PE and PE terephthalate samples did not inhibit bacterial growth as effectively as glass samples: three nanoparticle-coating cycles were needed to inhibit E. coli growth, and more than 30 coating cycles were needed until S. aureus growth was inhibited. To conclude, with the LFS method, it is possible to produce nanostructured large-area antibacterial surfaces which show

Pulsed laser deposition of antimicrobial silver coating on Ormocer (registered) microneedles

Energy Technology Data Exchange (ETDEWEB)

Gittard, S D; Narayan, R J; Jin, C; Monteiro-Riviere, N A [Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Ovsianikov, A; Chichkov, B N [Laser Zentrum Hannover, Hollerithallee 8, 30419 Hannover (Germany); Stafslien, S; Chisholm, B, E-mail: roger_narayan@msn.co [Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102 (United States)

2009-12-15

One promising option for transdermal delivery of protein- and nucleic acid-based pharmacologic agents involves the use of microneedles. However, microneedle-generated pores may allow microorganisms to penetrate the stratum corneum layer of the epidermis and cause local or systemic infection. In this study, microneedles with antimicrobial functionality were fabricated using two-photon polymerization-micromolding and pulsed laser deposition. The antibacterial activity of the silver-coated organically modified ceramic (Ormocer (registered) ) microneedles was demonstrated using an agar diffusion assay. Human epidermal keratinocyte viability on the Ormocer (registered) surfaces coated with silver was similar to that on uncoated Ormocer (registered) surfaces. This study indicates that coating microneedles with silver thin films using pulsed laser deposition is a useful and novel approach for creating microneedles with antimicrobial functionality. (communication)

Pulsed laser deposition of antimicrobial silver coating on Ormocer (registered) microneedles

International Nuclear Information System (INIS)

Gittard, S D; Narayan, R J; Jin, C; Monteiro-Riviere, N A; Ovsianikov, A; Chichkov, B N; Stafslien, S; Chisholm, B

2009-01-01

One promising option for transdermal delivery of protein- and nucleic acid-based pharmacologic agents involves the use of microneedles. However, microneedle-generated pores may allow microorganisms to penetrate the stratum corneum layer of the epidermis and cause local or systemic infection. In this study, microneedles with antimicrobial functionality were fabricated using two-photon polymerization-micromolding and pulsed laser deposition. The antibacterial activity of the silver-coated organically modified ceramic (Ormocer (registered) ) microneedles was demonstrated using an agar diffusion assay. Human epidermal keratinocyte viability on the Ormocer (registered) surfaces coated with silver was similar to that on uncoated Ormocer (registered) surfaces. This study indicates that coating microneedles with silver thin films using pulsed laser deposition is a useful and novel approach for creating microneedles with antimicrobial functionality. (communication)

Bovine Serum Albumin and Chitosan Coated Silver Nanoparticles and Its Antimicrobial Activity against Oral and Nonoral Bacteria

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León Francisco Espinosa-Cristóbal

2015-01-01

Full Text Available Antimicrobial agents have been developed for drug-resistance infections, which have been rapidly increasing; however, the control of involved microorganisms is still a challenge. In this work, SNP with bovine serum albumin (BSA and chitosan (CS coatings were prepared with an aqueous reduction method, characterized using dispersion light scattering, transmission electron microscopy, and thermal analysis. Antibacterial activity was tested on seven oral and nonoral bacteria by microdilution test and scanning electron microscopy. Six different sizes and shapes of coated SNP were prepared and used. Characterization revealed narrow size and good distribution of particles, spherical and pseudospherical shapes, and the presence of coatings on the SNP surfaces. All samples showed antimicrobial activity, although smaller sizes and CS samples had the best inhibition effects. The highest microbial resistance was shown by Gram-positive bacteria. Although coated SNP action depends on particular bacterium, BSA and CS coated SNP could be used for drug-resistance infections.

Antimicrobial coatings on polyethylene terephthalate based on curcumin/cyclodextrin complex embedded in a multilayer polyelectrolyte architecture.

Science.gov (United States)

Shlar, Ilya; Droby, Samir; Rodov, Victor

2018-04-01

Bacterial contamination is a growing concern worldwide. The aim of this work was to develop an antimicrobial coating based on curcumin-cyclodextrin inclusion complex and using polyethylene terephthalate (PET) film as a support matrix. After a pre-treatment aimed to provide sufficient electric charge to the PET surface, it was electrostatically coated with repeated multilayers comprising alternately deposited positively-charged poly-l-lysine (PLL) and negatively-charged poly-l-glutamic acid (PLGA) and carboxymethyl-β-cyclodextrin (CMBCD). The coatings had an architecture (PLL-PLGA) 6 -(PLL-PLGA-PLL-CMBCD) n , with the number of repeated multilayers n varying from 5 to 20. The CMBCD molecules were either covalently cross-linked using carbodiimide crosslinker chemistry or left unbound. The surface morphology, structure and elemental composition of the coatings were analysed by scanning electron microscopy and energy dispersive x-ray spectroscopy. To impart antimicrobial properties to the coatings they were loaded with a natural phenolic compound curcumin forming inclusion complexes with β-cyclodextrin. The non-cross-linked coatings showed bactericidal activity towards Escherichia coli in the dark, and this activity was further enhanced upon illumination with white light. Curcumin was released from the non-cross-linked coatings into an aqueous medium in the form of cyclodextrin inclusion complex. After the cross-linking, the coating lost its dark antimicrobial activity but retained the photodynamic properties. Stabilized cross-linked curcumin-loaded coatings can serve a basis for developing photoactivated antimicrobial surfaces controlling bacterial contamination and spread. Copyright © 2018 Elsevier B.V. All rights reserved.

Dual-coating of liposomes as encapsulating matrix of antimicrobial peptides: Development and characterization

Science.gov (United States)

Gomaa, Ahmed I.; Martinent, Cynthia; Hammami, Riadh; Fliss, Ismail; Subirade, Muriel

2017-11-01

Abstract Antimicrobial peptides have been proposed as a potential biopreservatives in pharmaceutical research and agribusiness. However, many limitations hinder their utilization, such as their vulnerability to proteolytic digestion and their potential interaction with other food ingredients in complex food systems. One approach to overcome such problems is developing formulations entrapping and thereby protecting the antimicrobial peptides. Liposome encapsulation is a strategy that could be implemented to combine protection of the antimicrobial activity of the peptides from proteolytic enzymes and the controlled release of the encapsulated active ingredients. The objective of this study was to develop dual-coated food grade liposome formulations for oral administration of bacteriocins. The formulations were developed from anionic and cationic phospholipids as models of negatively and positively charged liposomes, respectively. Liposomes were prepared by the hydration of lipid films. Subsequently, the liposomes were coated with two layers comprising a biopolymer network (pectin) and whey proteins (WPI) in order to further improve their stability and enable the gradual release of the developed liposomes. Liposomes were characterized for their size, charge, molecular structure, morphology, encapsulation efficiency and release. The results of FTIR, zeta potential, size distribution and transmission electron microscopy confirmed that the liposomes were efficiently coated. Ionic interactions were involved in the stabilization of the positively charged liposome formulations. Negatively charge liposome formulations were stabilized through weak interactions. The release study proved the efficiency of dual coating on the protection of liposomes against gastrointestinal digestion. This work is the first to study the encapsulation of antimicrobial peptides in dual-coated liposomes. Furthermore, the work successfully encapsulated MccJ25 in both negative and positive liposome

Melimine-Coated Antimicrobial Contact Lenses Reduce Microbial Keratitis in an Animal Model.

Science.gov (United States)

Dutta, Debarun; Vijay, Ajay K; Kumar, Naresh; Willcox, Mark D P

2016-10-01

To determine the ability of antimicrobial peptide melimine-coated contact lenses to reduce the incidence of microbial keratitis (MK) in a rabbit model of contact lens wear. In vitro antimicrobial activity of melimine-coated contact lenses was determined against Pseudomonas aeruginosa by viable count and a radiolabeled assay. The amount of lipopolysaccharide (LPS) associated with bacteria bound to melimine-coated and control lenses was determined. Ocular swabs from rabbit eyes were collected for assessment of ocular microflora. A rabbit model for MK was developed that used overnight wear of contact lenses colonized by P. aeruginosa in the absence of a corneal scratch. During lens wear, detailed ocular examinations were performed, and the incidence of MK was investigated. Bacteria associated with worn lenses and infected corneas were determined by viable plate count. Inhibition in viable and total P. aeruginosa adhesion by melimine-coated contact lenses was 3.1 log10 and 0.4 log10, respectively. After colonization, the amount of LPS on lenses was approximately the same with or without melimine. Gram-positive bacteria were found in all the ocular swabs followed by fungus (42%). Melimine-coated lens wear was protective and significantly (odds ratio 10.12; P = 0.012) reduced the incidence of P. aeruginosa-driven MK in the rabbit model. The antimicrobial lenses were associated with significantly (P lenses can produce MK without corneal epithelial defect in an animal model. Melimine-coated contact lenses reduced the incidence of MK associated with P. aeruginosa in vivo. Development of MK requires viable bacteria adherent to contact lenses, and bacterial debris adherent at the lens surface did not cause keratitis.

Influence of thickness and coatings morphology in the antimicrobial performance of zinc oxide coatings

Energy Technology Data Exchange (ETDEWEB)

Carvalho, P. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Sampaio, P. [CBMA, University of Minho, Campus de Gualtar, 4700 Braga (Portugal); Azevedo, S. [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Vaz, C. [CBMA, University of Minho, Campus de Gualtar, 4700 Braga (Portugal); Espinós, J.P. [Instituto de Ciencia de Materiales de Sevilla, CSIC-University of Sevilla, Avda. Américo Vespucio 49, 41092 Sevilla (Spain); Teixeira, V., E-mail: vasco@fisica.uminho.pt [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal); Carneiro, J.O., E-mail: carneiro@fisica.uminho.pt [Department of Physics, University of Minho, Campus de Azurém, 4800-058 Guimaraes (Portugal)

2014-07-01

In this research work, the production of undoped and silver (Ag) doped zinc oxide (ZnO) thin films for food-packaging applications were developed. The main goal was to determine the influence of coatings morphology and thickness on the antimicrobial performance of the produced samples. The ZnO based thin films were deposited on PET (Polyethylene terephthalate) substrates by means of DC reactive magnetron sputtering. The thin films were characterized by optical spectroscopy, X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy (SEM). The antimicrobial performance of the undoped and Ag-doped ZnO thin films was also evaluated. The results attained have shown that all the deposited zinc oxide and Ag-doped ZnO coatings present columnar morphology with V-shaped columns. The increase of ZnO coatings thickness until 200 nm increases the active surface area of the columns. The thinner samples (50 and 100 nm) present a less pronounced antibacterial activity than the thickest ones (200–600 nm). Regarding Ag-doped ZnO thin films, it was verified that increasing the silver content decreases the growth rate of Escherichia coli and decreases the amount of bacteria cells present at the end of the experiment.

Biocompatible antimicrobial cotton fibres for healthcare industries: a biogenic approach for synthesis of bio-organic-coated silver nanoparticles.

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Kashid, Sahebrao B; Lakkakula, Jaya R; Chauhan, Deepak S; Srivastava, Rohit; Raut, Rajesh W

2017-12-01

Cotton fibres coated with biogenically fabricated silver nanoparticles (SNPs) are most sought material because of their enhanced activity and biocompatibility. After successful synthesis of SNPs on cotton fibres using leaf extract of Vitex negundo Linn, the fibres were studied using diffuse reflectance spectroscopy, scanning electron microscopy, nanoparticle tracking analysis, energy dispersive X-ray, and inductively coupled plasma atomic emission spectrometry. The characterisation revealed uniformly distributed spherical agglomerates of SNPs having individual particle size around 50 nm with the deposition load of 423 μg of silver per gram of cotton. Antimicrobial assay of cotton-SNPs fibres showed effective performance against pathogenic bacteria and fungi. The method is biogenic, environmentally benign, rapid, and cost-effective, producing highly biocompatible antimicrobial coating required for the healthcare industry.

Antimicrobial activity of lauric arginate-coated polylactic acid films against Listeria monocytogenes and Salmonella typhimurium on cooked sliced ham.

Science.gov (United States)

Theinsathid, Pornpun; Visessanguan, Wonnop; Kruenate, Jittiporn; Kingcha, Yutthana; Keeratipibul, Suwimon

2012-02-01

A novel type of environmentally friendly packaging with antibacterial activity was developed from lauric arginate (LAE)-coating of polylactic acid (PLA) films after surface activation using a corona discharge. Scanning electron microscopy (SEM)-based analysis of the LAE/PLA films confirmed the successful coating of LAE on the PLA surface. The mechanical properties of the LAE/PLA films with different levels of LAE-coating (0% to 2.6%[w/w]) were essentially the same as those of the neat PLA film. The antibacterial activity of the LAE/PLA films against Listeria monocytogenes and Salmonella enterica Serovar Typhimurium (S. Typhimurium) was confirmed by a qualitative modified agar diffusion assay and quantitative JIS Z 2801:2000 method. Using the LAE/PLA film as a food-contact antimicrobial packaging for cooked cured ham, as a model system, suggested a potential application to inhibit L. monocytogenes and S. Typhimurium on ham with a 0.07% (w/w) LAE coating on the PLA when high transparency is required, as evidenced from the 2 to 3 log CFU/tested film lower pathogen growth after 7 d storage but even greater antibacterial activity is obtained with a LAE coating level of 2.6% (w/w) but at the cost of a reduced transparency of the finished product. This article shows how we can simply develop functional green packaging of PLA for food with effective and efficient antimicrobial activity by use of LAE coating on the surface via corona discharge. The effectiveness of an innovative antimicrobial LAE-coated PLA film against foodborne pathogens was demonstrated. Importantly, the application of the LAE to form the LAE-coated PLA film can be customized within current film manufacturing lines. © 2012 Institute of Food Technologists®

Antimicrobial Activity of TiO2 Nanoparticle-Coated Film for Potential Food Packaging Applications

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Siti Hajar Othman

2014-01-01

Full Text Available Recent uses of titanium dioxide (TiO2 have involved various applications which include the food industry. This study aims to develop TiO2 nanoparticle-coated film for potential food packaging applications due to the photocatalytic antimicrobial property of TiO2. The TiO2 nanoparticles with varying concentrations (0–0.11 g/ 100 mL organic solvent were coated on food packaging film, particularly low density polyethylene (LDPE film. The antimicrobial activity of the films was investigated by their capability to inactivate Escherichia coli (E. coli in an actual food packaging application test under various conditions, including types of light (fluorescent and ultraviolet (UV and the length of time the film was exposed to light (one–three days. The antimicrobial activity of the TiO2 nanoparticle-coated films exposed under both types of lighting was found to increase with an increase in the TiO2 nanoparticle concentration and the light exposure time. It was also found that the antimicrobial activity of the films exposed under UV light was higher than that under fluorescent light. The developed film has the potential to be used as a food packaging film that can extend the shelf life, maintain the quality, and assure the safety of food.

Application of Nanofibrillated Cellulose on BOPP/LDPE Film as Oxygen Barrier and Antimicrobial Coating Based on Cold Plasma Treatment

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Peng Lu

2018-05-01

Full Text Available The application of nanofibrillated cellulose (NC films in packaging industry has been hindered by its lack of heat-sealing ability. Incorporation of NC films with the biaxially oriented polypropylene/low density polyethylene (BOPP/LDPE laminates can take advantage of each material and endow the films with novel functions for food packaging applications. In this study, a coating that consists of NC and nisin was applied onto a cold plasma treated BOPP/LDPE film to fabricate a novel active packaging with an improved oxygen barrier performance and an added antimicrobial effect. The results showed that cold plasma treatment improved the surface hydrophilicity of BOPP/LDPE films for better attachment of the coatings. NC coatings significantly enhanced oxygen barrier property of the BOPP/LDPE film, with an oxygen transmission rate as low as 24.02 cc/m2·day as compared to that of the non-coated one (67.03 cc/m2·day. The addition of nisin in the coating at a concentration of 5 mg/g caused no significant change in barrier properties but imparted the film excellent antimicrobial properties, with a growth inhibition of L. monocytogenes by 94%. All films exhibit satisfying mechanical properties and transparency, and this new film has the potential to be used as antimicrobial and oxygen barrier packaging.

Hybrid Antifouling and Antimicrobial Coatings Prepared by Electroless Co-Deposition of Fluoropolymer and Cationic Silica Nanoparticles on Stainless Steel: Efficacy against Listeria monocytogenes.

Science.gov (United States)

Huang, Kang; Chen, Juhong; Nugen, Sam R; Goddard, Julie M

2016-06-29

Controlling formation, establishment, and proliferation of microbial biofilms on surfaces is critical for ensuring public safety. Herein, we report on the synthesis of antimicrobial nanoparticles and their co-deposition along with fluorinated nanoparticles during electroless nickel plating of stainless steel. Plating bath composition is optimized to ensure sufficiently low surface energy to resist fouling and microbial adhesion as well as to exert significant (>99.99% reduction) antimicrobial activity against Listeria monocytogenes. The resulting coatings present hybrid antifouling and antimicrobial character, can be applied onto stainless steel, and do not rely on leaching or migration of the antimicrobial nanoparticles to be effective. Such coatings can support reducing public health issues related to microbial cross-contamination in areas such as food processing, hospitals, and water purification.

Specialised cleaning associated with antimicrobial coatings for reduction of hospital acquired infection. Opinion of the COST Action Network AMiCI (CA15114).

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Dunne, Suzanne S; Ahonen, Merja; Modic, Martina; Crijns, Francy Rl; Keinänen-Toivola, Minna M; Meinke, Ruth; Keevil, C William; Gray, Jim; O'Connell, Nuala H; Dunne, Colum P

2018-03-14

Recognized issues with poor hand hygiene compliance among healthcare workers, and reports of re-contamination of previously chemically disinfected surfaces through hand contact, emphasize need for novel hygiene methods in addition to those currently available. One such approach involves antimicrobial (nano)-coatings (AMC), whereby integrated active ingredients are responsible for elimination of microorganisms that come into contact with treated surfaces. While widely studied under laboratory conditions with promising results, studies under real life healthcare conditions are scarce. The views of 75 contributors from 30 European countries were collated regarding specialised cleaning associated with antimicrobial coatings for reduction of hospital acquired infection. There was unanimous agreement that generation of scientific guidelines for cleaning of antimicrobial coatings, using traditional or new processes, are needed. Specific topics included: understanding mechanisms of action of cleaning materials and their physical interactions with conventional and antimicrobial coatings; that assessments mimic the life-cycle of coatings to determine the impact of repetitive cleaning and other aspects of ageing (e.g., exposure to sunlight); determining concentrations of AMC-derived biocides in effluents, and development of effective de-activation and sterilisation treatments for cleaning effluents. Further, the consensus opinion was that prior to widespread implementation of AMCs, the varying responsibilities of involved clinical, healthcare management, cleaning services, and environmental safety stakeholders need clarification. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Antimicrobial particulate silver coatings on stainless steel implants for fracture management

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DeVasConCellos, Paul; Bose, Susmita [W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA (United States); Beyenal, Haluk [School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA (United States); Bandyopadhyay, Amit, E-mail: amitband@wsu.edu [W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA (United States); Zirkle, Lewis G. [Surgical Implant Generation Network (SIGN), Richland, WA (United States)

2012-07-01

We have used particulate silver coating on stainless steel to prevent in vivo bacterial infection. Stainless steel is commonly used as an implant material for fracture management. The antimicrobial use of silver has been well documented and studied, therefore the novelty of this research is the use of a particulate coating as well as facing the real world challenges of a fracture repair implant. The variable parameters for applying the coating were time of deposition, silver solution concentration, voltage applied, heat treatment temperature between 400 and 500 Degree-Sign C and time. The resultant coating is shown to be non-toxic to human osteoblasts using an MTT assay for proliferation and SEM images for morphology. In vitro silver release studies of various treatments were done using simulated body fluid. The bactericidal effects were tested by challenging the coatings with Pseudomonas aeruginosa in a bioreactor and compared against uncoated stainless steel. A 13-fold reduction in bacteria was observed at 24 h and proved to be statistically significant. - Highlights: Black-Right-Pointing-Pointer Processing of particulate silver coating that are strongly adherent on SS surface. Black-Right-Pointing-Pointer Optimized the amount of silver that is sufficient to reduce bacterial colonization but non-toxic to human bone tissue. Black-Right-Pointing-Pointer The adhesion strength of silver was sufficient to survive industrial sterilization steps used for fracture management devices.

Antimicrobial particulate silver coatings on stainless steel implants for fracture management

International Nuclear Information System (INIS)

DeVasConCellos, Paul; Bose, Susmita; Beyenal, Haluk; Bandyopadhyay, Amit; Zirkle, Lewis G.

2012-01-01

We have used particulate silver coating on stainless steel to prevent in vivo bacterial infection. Stainless steel is commonly used as an implant material for fracture management. The antimicrobial use of silver has been well documented and studied, therefore the novelty of this research is the use of a particulate coating as well as facing the real world challenges of a fracture repair implant. The variable parameters for applying the coating were time of deposition, silver solution concentration, voltage applied, heat treatment temperature between 400 and 500 °C and time. The resultant coating is shown to be non-toxic to human osteoblasts using an MTT assay for proliferation and SEM images for morphology. In vitro silver release studies of various treatments were done using simulated body fluid. The bactericidal effects were tested by challenging the coatings with Pseudomonas aeruginosa in a bioreactor and compared against uncoated stainless steel. A 13-fold reduction in bacteria was observed at 24 h and proved to be statistically significant. - Highlights: ► Processing of particulate silver coating that are strongly adherent on SS surface. ► Optimized the amount of silver that is sufficient to reduce bacterial colonization but non-toxic to human bone tissue. ► The adhesion strength of silver was sufficient to survive industrial sterilization steps used for fracture management devices.

Antimicrobial activities of tapioca starch/decolorized hsian-tsao leaf gum coatings containing green tea extracts in fruit-based salads, romaine hearts and pork slices.

Science.gov (United States)

Chiu, Po-En; Lai, Lih-Shiuh

2010-04-30

The antimicrobial activities of edible coatings based on a tapioca starch/decolorized hsian-tsao leaf gum (dHG) matrix with various green tea extracts (GTEs) were evaluated. Its effect on the shelf-life extension of fruit-based salads, romaine hearts, and pork slices were investigated as well. Three types of GTEs from hot water (80 degrees C) (W), 40% (E4) and 80% (E8) ethanol were prepared. It was found that all GTEs showed pronounced inhibition on Gram positive bacteria in agar media, including Staphylococcus aureus BCRC 10781, Bacillus cereus BCRC 11778 and Listeria monocytogenes BCRC 14848, but not on Gram negative bacteria, such as Escherichia coli DH10beta and Salmonella enteria BCRC 10747. The antimicrobial activities increased with increasing GTEs concentration (1, 2 and 5%), but did not differentiate significantly in terms of the effect of extraction solvents. When various GTEs (1%) were added to an edible coating formulation based on 1.35% tapioca starch +0.15% dHG +0.225% glycerol, pronounced antimicrobial activity on Gram positive bacteria was also observed as evaluated by using cylinder diffusion and antimicrobial migration tests. It was believed that the active compounds in green tea extracts could leave the coating matrix and migrate to increase the non-growth area. When being sprayed on various real food models, all tapioca starch/dHG coatings containing GTEs could successfully reduce the aerobic counting and growth of yeasts/molds by 1 to 2 log cycles in fruit-based salads, as compared to the control sample. Furthermore, during refrigerated storage of romaine hearts and pork slices for 48h, tapioca starch/dHG coatings with E4 extracts demonstrated pronounced antimicrobial activity against Gram positive bacteria (4-6 log cycles reduction), followed by W extracts and E8 extracts in a decreasing order. Such results implied the high efficacy of antimicrobial migration of tapioca starch/dHG coatings containing GTEs and their application potentials on

Antimicrobial beeswax coated polylactide films with silver control release capacity.

Science.gov (United States)

Martínez-Abad, Antonio; Lagarón, Jose Maria; Ocio, María Jose

2014-03-17

Although the application of silver based antimicrobial systems is a widespread technology, its implementation in areas such as food packaging is still challenging. The present paper describes the fabrication of poly(lactic acid) (PLA) coated with beeswax with controlled release properties for sustained antimicrobial performance. Release of silver ions from the polymers was monitored voltammetrically under various conditions (surface contact, immersion in various liquid media and at different pH values) throughout at least 7days. A higher release was noted with decreasing pH while surface release was much slower than the release when immersed in liquid medium. While uncoated films demonstrated a high burst release which in some instances implied surpassing some current migration restrictions (food), the addition of a beeswax layer allowed a sustained release of the antimicrobial compound. Increasing the thickness of the beeswax layer resulted in an increase in the water barrier properties of the films while reducing the relatively constant values of sustained release. Antimicrobial performance was correlated with the release of silver ions, indicating threshold concentrations for biocide action of films displayed a strong bactericidal effect against Salmonella enterica. The application of this functional barrier thus offers the possibility of tuning the release profiles of the films to suit a specific application and puts forth the possible suitability of these materials for food packaging or other migration sensitive applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Preparation of the antithrombotic and antimicrobial coating through layer-by-layer self-assembly of nattokinase-nanosilver complex and polyethylenimine.

Science.gov (United States)

Wei, Xuetuan; Luo, Mingfang; Liu, Huizhou

2014-04-01

The bifunctional coating with antithrombotic and antimicrobial activity was developed using nattokinase (NK) and nanosilver (AgNPs). Firstly, the adsorption interactions between NK and AgNPs were confirmed, and the composite particles of NK-AgNPs were prepared by adsorption of NK with AgNPs. At 5FU/mL of NK concentration, the saturation adsorption capacity reached 24.35 FU/mg AgNPs with a high activity recovery of 97%, and adsorption by AgNPs also enhanced the heat stability and anticoagulant effect of NK. Based on the electrostatic force driven layer-by-layer self-assembly, the NK-AgNPs were further assembled with polyethylenimine (PEI) to form coating. UV-vis analysis showed that the self-assembly process was regular, and atom force microscopy analysis indicated that NK-AgNPs were uniformly embedded into the coating. The NK-AgNPs-PEI composite coating showed potent antithrombotic activity and antibacterial activity. This study developed a novel strategy to construct the bifunctional coating with antithrombotic and antimicrobial properties, and the coating material showed promising potential to be applied in the medical device. Copyright © 2014 Elsevier B.V. All rights reserved.

Proactive Approach for Safe Use of Antimicrobial Coatings in Healthcare Settings: Opinion of the COST Action Network AMiCI

Directory of Open Access Journals (Sweden)

Merja Ahonen

2017-03-01

Full Text Available Infections and infectious diseases are considered a major challenge to human health in healthcare units worldwide. This opinion paper was initiated by EU COST Action network AMiCI (AntiMicrobial Coating Innovations and focuses on scientific information essential for weighing the risks and benefits of antimicrobial surfaces in healthcare settings. Particular attention is drawn on nanomaterial-based antimicrobial surfaces in frequently-touched areas in healthcare settings and the potential of these nano-enabled coatings to induce (ecotoxicological hazard and antimicrobial resistance. Possibilities to minimize those risks e.g., at the level of safe-by-design are demonstrated.

Development of antimicrobial coating by later-by-layer dip coating of chlorhexidine-loaded micelles.

Science.gov (United States)

Tambunlertchai, Supreeda; Srisang, Siriwan; Nasongkla, Norased

2017-06-01

Layer-by-layer (LbL) dip coating, accompanying with the use of micelle structure, allows hydrophobic molecules to be coated on medical devices' surface via hydrogen bonding interaction. In addition, micelle structure also allows control release of encapsulated compound. In this research, we investigated methods to coat and maximize the amount of chlorhexidine (CHX) on silicone surface through LbL dip coating method utilizing hydrogen bonding interaction between PEG on micelle corona and PAA. The number of coated cycles was varied in the process and 90 coating cycles provided the maximum amount of CHX loaded onto the surface. In addition, pre-coating the surface with PAA enhanced the amount of coated CHX by 20%. Scanning electron microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used to validate and characterize the coating. For control release aspect, the coated film tended to disrupt at physiological condition; hence chemical crosslinking was performed to minimize the disruption and maximize the release time. Chemical crosslinking at pH 2.5 and 4.5 were performed in the process. It was found that chemical crosslinking could help extend the release period up to 18 days. This was significantly longer when compared to the non-crosslinking silicone tube that could only prolong the release for 5 days. In addition, chemical crosslinking at pH 2.5 gave higher and better initial burst release, release period and antimicrobial properties than that of pH 4.5 or the normal used pH for chemical crosslinking process.

Antimicrobial polycaprolactone/polyethylene glycol embedded lysozyme coatings of Ti implants for osteoblast functional properties in tissue engineering

Science.gov (United States)

Visan, A.; Cristescu, R.; Stefan, N.; Miroiu, M.; Nita, C.; Socol, M.; Florica, C.; Rasoga, O.; Zgura, I.; Sima, L. E.; Chiritoiu, M.; Chifiriuc, M. C.; Holban, A. M.; Mihailescu, I. N.; Socol, G.

2017-09-01

In this study, coatings based on lysozyme embedded into a matrix of polyethylene glycol (PEG) and polycaprolactone (PCL) were fabricated by two different methods (Matrix Assisted Pulsed Laser Evaporation - MAPLE and Dip Coating) for obtaining antimicrobial coatings envisaged for long term medical applications. Coatings with different PEG:PCL compositions (3:1; 1:1; 1:3) were synthesized in order to evaluate the antimicrobial activity of lysozyme embedded into the polymeric matrix. The main surface features, such as roughness and wettability, with impact on the microbial adhesion as well as on the eukaryote cell function were measured. The obtained composite coatings exhibited a significant antibacterial activity against Escherichia coli, Bacillus subtilis, Enterococcus faecalis and Staphylococcus aureus strains. As well, specific blended coatings showed appropriate viability, good spreading and normal cell morphology of SaOs2 human osteoblasts and mesenchymal stem cells (MSCs). These investigations highlight the suitability of biodegradable composites as implant coatings for decreasing the risk of bacterial contamination associated with prosthetic procedures.

Particulate Respirators Functionalized with Silver Nanoparticles Showed Excellent Real-Time Antimicrobial Effects against Pathogens.

Science.gov (United States)

Zheng, Clark Renjun; Li, Shuai; Ye, Chengsong; Li, Xinyang; Zhang, Chiqian; Yu, Xin

2016-07-05

Particulate respirators designed to filtrate fine particulate matters usually do not possess antimicrobial functions. The current study aimed to functionalize particulate respirators with silver nanoparticles (nanosilver or AgNPs), which have excellent antimicrobial activities, utilizing a straightforward and effective method. We first enhanced the nanosilver-coating ability of nonwoven fabrics from a particulate respirator through surface modification by sodium oleate. The surfactant treatment significantly improved the fabrics' water wet preference where the static water contact angles reduced from 122° to 56°. Both macroscopic agar-plate tests and microscopic scanning electron microscope (SEM) characterization revealed that nanosilver functionalized fabrics could effectively inhibit the growth of two model bacterial strains (i.e., Staphylococcus aureus and Pseudomonas aeruginosa). The coating of silver nanoparticles would not affect the main function of particulate respirators (i.e., filtration of fine air-borne particles). Nanosilver coated particulate respirators with excellent antimicrobial activities can provide real-time protection to people in regions with severe air pollution against air-borne pathogens.

Anhydrous polymer-based coating with sustainable controlled release functionality for facile, efficacious impregnation, and delivery of antimicrobial peptides.

Science.gov (United States)

Lim, Kaiyang; Saravanan, Rathi; Chong, Kelvin K L; Goh, Sharon H M; Chua, Ray R Y; Tambyah, Paul A; Chang, Matthew W; Kline, Kimberly A; Leong, Susanna S J

2018-04-17

Anhydrous polymers are actively explored as alternative materials to overcome limitations of conventional hydrogel-based antibacterial coating. However, the requirement for strong organic solvent in polymerization reactions often necessitates extra protection steps for encapsulation of target biomolecules, lowering encapsulation efficiency, and increasing process complexity. This study reports a novel coating strategy that allows direct solvation and encapsulation of antimicrobial peptides (HHC36) into anhydrous polycaprolactone (PCL) polymer-based dual layer coating. A thin 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) film is layered onto the peptide-impregnated PCL as a diffusion barrier, to modulate and enhance release kinetics. The impregnated peptides are eventually released in a controlled fashion. The use of 2,2,2-trifluoroethanol (TFE), as polymerization and solvation medium, induces the impregnated peptides to adopt highly stable turned conformation, conserving peptide integrity, and functionality during both encapsulation and subsequent release processes. The dual layer coating showed sustained antibacterial functionality, lasting for 14 days. In vivo assessment using an experimental mouse wounding model demonstrated good biocompatibility and significant antimicrobial efficacy of the coating under physiological conditions. The coating was translated onto silicone urinary catheters and showed promising antibacterial efficacy, even outperforming commercial silver-based Dover cather. This anhydrous polymer-based platform holds immense potential as an effective antibacterial coating to prevent clinical device-associated infections. The simplicity of the coating process enhances its industrial viability. © 2018 Wiley Periodicals, Inc.

In vivo osseointegration of dental implants with an antimicrobial peptide coating.

Science.gov (United States)

Chen, X; Zhou, X C; Liu, S; Wu, R F; Aparicio, C; Wu, J Y

2017-05-01

This study aimed to evaluate the in vivo osseointegration of implants with hydrophobic antimicrobial GL13K-peptide coating in rabbit femoral condyles by micro-CT and histological analysis. Six male Japanese Rabbits (4 months old and weighing 2.5 kg each) were included in this study. Twelve implants (3.75 mm wide, 7 mm long) were randomly distributed in two groups, with six implants in the experimental group coated with GL13K peptide and six implants in the control group without surface coating. Each implant in the test and the control group was randomly implanted in the left or right side of femoral condyles. On one side randomly-selected of the femur, each rabbit received a drill that was left without implant as control for the natural healing of bone. After 3 weeks of healing radiographic evaluation of the implant sites was taken. After 6 weeks of healing, rabbits were sacrificed for evaluation of the short-term osseointegration of the dental implants using digital radiography, micro-CT and histology analysis. To perform evaluation of osseointegration, implant location and group was double blinded for surgeon and histology/radiology researcher. Two rabbits died of wound infection in sites with non-coated implants 2 weeks after surgery. Thus, at least four rabbits per group survived after 6 weeks of healing. The wounds healed without suppuration and inflammation. No implant was loose after 6 weeks of healing. Radiography observations showed good osseointegration after 3 and 6 weeks postoperatively, which proved that the tissues followed a natural healing process. Micro-CT reconstruction and analysis showed that there was no statistically significant difference (P > 0.05) in volume of bone around the implant between implants coated with GL13K peptide and implants without coating. Histomorphometric analysis also showed that the mineralized bone area was no statistically different (P > 0.05) between implants coated with GL13K peptide and

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

Science.gov (United States)

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

2016-03-02

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

ANTIMICROBIAL PROPERTIES OF HYDROXYAPATITE COATINGS CONTAINING OF CHITOSAN AND SILVER ON TITANIUM SUBSTRATES IN RELATION TO MICROORGANISMS E.COLI ATCC 25922

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Sukhodub LB

2013-03-01

Full Text Available In this work it was studied the antibacterial properties of coatings based on HA, with Chitosan and silver ions additions, produced by substrates termodeposition method from aqueous solutions with varying concentrations of Chitosan (0.025 and 0.1 g/l and silver (1 mg/l as the antimicrobial components as well as three-part cover, consisting of a film of Chitosan, HA and silver. Study on antibacterial properties of composite coatings on the pathogen E.coli ATCC 25922 was held by Spectrophotometric measurement and analysis of optical density of suspensions, containing samples. 3 series of measurements data were averaged. The results showed that the concentration of antimicrobial components have indicated a bacteriostatic effect of coatings on the culture of E. coli AS ATCC 25922 in physiological solution at a temperature of 37 °C. The most effective was the three-part cover consisting of a film of chitosan, HA and silver.

Feasibility Study Exploring the Potential of Novel Battacin Lipopeptides as Antimicrobial Coatings.

Science.gov (United States)

De Zoysa, Gayan Heruka; Sarojini, Vijayalekshmi

2017-01-18

Colonization of medical implant surfaces by pathogenic microorganisms causes implant failure and undermines their clinical applicability. Alarming increase in multidrug-resistant bacteria poses serious concerns with the use of medical implants. Antimicrobial peptides (AMPs) that form part of the innate immune system in all forms of life are attractive alternatives to conventional antibiotics to treat multidrug-resistant bacterial biofilms. The aim of this study was to assess the in vitro antibacterial potency of our recently discovered lipopeptides from the battacin family upon immobilization to various surfaces. To achieve this, glass, silicon, and titanium surfaces were functionalized through silanization followed by addition of the heterobifunctional cross-linker, succinimidyl-[N-maleimidopropionamido]-poly(ethylene glycol) ester to generate maleimide-functionalized surfaces. The lipopeptide, GZ3.27, with an added N-terminal cysteine was covalently coupled to the surfaces via a thioether bond through a Michael-type addition between the cysteine sulfhydryl group and the maleimide moiety. Success of surface immobilization and antimicrobial activity of the coated surfaces was assessed using water contact angle measurements, X-ray photoelectron spectroscopy, ellipsometry, scanning electron microscopy, colony forming unit assays and biofilm analysis. The lipopeptide-coated surfaces caused significant damage to the cellular envelop of Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli) upon contact and prevented surface colonization by P. aeruginosa and E. coli biofilms. The lipopeptides investigated in this study were not hemolytic to mouse blood cells in solution. Findings from this study indicate that these lipopeptides have the potential to be developed as promising antimicrobial coatings on medical implants.

Development of Antimicrobial Coatings by Atmospheric Pressure Plasma Using a Guanidine-Based Precursor

Science.gov (United States)

2013-10-29

AP- PECVD) process to develop coatings from a guanidine-derived monomer, 1,1,3,3-tetramethylguanidine ( TMG ), that impart antimicrobial behavior onto...cleaned in ethanol and dried in open air. The antimicrobial agent, 1,1,3,3- tetramethylguanidine ( TMG ) (99%, Aldrich), was used as received. TMG ...solutions used in the deposition process included 1.0, 5.0, and 10.0% (w/w) of TMG in deionized water (Milli-Q, 18 MΩ•cm) and were used to study the role

Inactivation of E.coli O157:H7 and Salmonella on fresh strawberries by antimicrobial washing and coating

Science.gov (United States)

Antimicrobial washing, antimicrobial coating, and a combination of both treatments were evaluated for their ability to inactivate artificially inoculated foodborne pathogens and native microflora on strawberries stored at 4 degrees C. Strawberries were inoculated with a six-strain composite of E. co...

New Strategies in the Development of Antimicrobial Coatings: The Example of Increasing Usage of Silver and Silver Nanoparticles

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Leo H. Koole

2011-01-01

Full Text Available Bacterial infection from medical devices is a major problem and accounts for an increasing number of deaths as well as high medical costs. Many different strategies have been developed to decrease the incidence of medical device related infection. One way to prevent infection is by modifying the surface of the devices in such a way that no bacterial adhesion can occur. This requires modification of the complete surface with, mostly, hydrophilic polymeric surface coatings. These materials are designed to be non-fouling, meaning that protein adsorption and subsequent microbial adhesion are minimized. Incorporation of antimicrobial agents in the bulk material or as a surface coating has been considered a viable alternative for systemic application of antibiotics. However, the manifestation of more and more multi-drug resistant bacterial strains restrains the use of antibiotics in a preventive strategy. The application of silver nanoparticles on the surface of medical devices has been used to prevent bacterial adhesion and subsequent biofilm formation. The nanoparticles are either deposited directly on the device surface, or applied in a polymeric surface coating. The silver is slowly released from the surface, thereby killing the bacteria present near the surface. In the last decade there has been a surplus of studies applying the concept of silver nanoparticles as an antimicrobial agent on a range of different medical devices. The main problem however is that the exact antimicrobial mechanism of silver remains unclear. Additionally, the antimicrobial efficacy of silver on medical devices varies to a great extent. Here we will review existing antimicrobial coating strategies and discuss the use of silver or silver nanoparticles on surfaces that are designed to prevent medical device related infections.

Antimicrobial polymers - The antibacterial effect of photoactivated nano titanium dioxide polymer composites

International Nuclear Information System (INIS)

Huppmann, T.; Leonhardt, S.; Krampe, E.; Wintermantel, E.; Yatsenko, S.; Radovanovic, I.; Bastian, M.

2014-01-01

To obtain a polymer with antimicrobial properties for medical and sanitary applications nanoscale titanium dioxide (TiO 2 ) particles have been incorporated into a medical grade polypropylene (PP) matrix with various filler contents (0 wt %, 2 wt %, 10 wt % and 15 wt %). The standard application of TiO 2 for antimicrobial efficacy is to deposit a thin TiO 2 coating on the surface. In contrast to the common way of applying a coating, TiO 2 particles were applied into the bulk polymer. With this design we want to ensure antimicrobial properties even after application of impact effects that could lead to surface defects. The filler material (Aeroxide® TiO 2 P25, Evonik) was applied via melt compounding and the compounding parameters were optimized with respect to nanoscale titanium dioxide. In a next step the effect of UV-irradiation on the compounds concerning their photocatalytic activity, which is related to the titanium dioxide amount, was investigated. The photocatalytic effect of TiO 2 -PP-composites was analyzed by contact angle measurement, by methylene blue testing and by evaluation of inactivation potential for Escherichia coli (E.coli) bacteria. The dependence of antimicrobial activity on the filler content was evaluated, and on the basis of different titanium dioxide fractions adequate amounts of additives within the compounds were discussed. Specimens displayed a higher photocatalytic and also antimicrobial activity and lower contact angles with increasing titania content. The results suggest that the presence of titania embedded in the PP matrix leads to a surface change and a photocatalytic effect with bacteria killing result

Efficacy of antimicrobial pullulan-based coating to improve internal quality and shelf-life of chicken eggs during storage.

Science.gov (United States)

Morsy, Mohamed K; Sharoba, Ashraf M; Khalaf, Hassan H; El-Tanahy, Hassan H; Cutter, Catherine N

2015-05-01

There has been a growing interest in the use of natural materials as a delivery mechanism for antimicrobials and coatings in foods. The aim of the present study was to evaluate the effectiveness of pullulan coatings to improve internal quality and shelf-life of fresh eggs during 10 wk of storage at 25 and 4 °C. Three treatments of eggs were evaluated as follows; non-coated (control; C), coated with pullulan (P), and coated with pullulan containing nisin (N). The effects of the pullulan coatings on microbiological qualities, physical properties, and freshness parameters were investigated and compared with non-coated eggs. For non-coated eggs, as storage time increased, yolk index, albumen index, and Haugh unit value decreased and weight loss increased. However, pullulan coatings (P or N) minimized weight loss (eggs (with a final B grade) 3 wk longer than non-coated eggs at 25 °C. At 4 °C, both P- and N-coated eggs went from AA to A grade after 9 wk and maintained the grade for 10 wk (4 wk longer than that of non-coated eggs). This study is the first to demonstrate that pullulan coatings can preserve the internal quality, prolong the shelf-life, and minimize weight loss of fresh eggs. © 2015 Institute of Food Technologists®

Photocatalytic, Antimicrobial and Biocompatibility Features of Cotton Knit Coated with Fe-N-Doped Titanium Dioxide Nanoparticles

Directory of Open Access Journals (Sweden)

Miruna Silvia Stan

2016-09-01

Full Text Available Our research was focused on the evaluation of the photocatalytic and antimicrobial properties, as well as biocompatibility of cotton fabrics coated with fresh and reused dispersions of nanoscaled TiO2-1% Fe-N particles prepared by the hydrothermal method and post-annealed at 400 °C. The powders were characterized by X-ray diffraction (XRD, Mössbauer spectroscopy and X-ray photoelectron spectroscopy. The textiles coated with doped TiO2 were characterized by scanning electron microscopy and energy dispersive X-ray analyses, and their photocatalytic effect by trichromatic coordinates of the materials stained with methylene blue and coffee and exposed to UV, visible and solar light. The resulting doped TiO2 consists of a mixture of prevailing anatase phase and a small amount (~15%–20% of brookite, containing Fe3+ and nitrogen. By reusing dispersions of TiO2-1% Fe-N, high amounts of photocatalysts were deposited on the fabrics, and the photocatalytic activity was improved, especially under visible light. The treated fabrics exhibited specific antimicrobial features, which were dependent on their composition, microbial strain and incubation time. The in vitro biocompatibility evaluation on CCD-1070Sk dermal fibroblasts confirmed the absence of cytotoxicity after short-term exposure. These results highlight the potential of TiO2-1% Fe-N nanoparticles for further use in the development of innovative self-cleaning and antimicrobial photocatalytic cotton textiles. However, further studies are required in order to assess the long-term skin exposure effects and the possible particle release due to wearing.

Preparation of an orthodontic bracket coated with an nitrogen-doped TiO(2-x)N(y) thin film and examination of its antimicrobial performance.

Science.gov (United States)

Cao, Baocheng; Wang, Yuhua; Li, Na; Liu, Bin; Zhang, Yingjie

2013-01-01

A bracket coated with a nitrogen-doped (N-doped) TiO(2-x)N(y) thin film was prepared using the RF magnetron sputtering method. The physicochemical properties of the thin film were measured using X-ray diffraction and energy-dispersive X-ray spectrometry, while the antimicrobial activity of the bracket against common oral pathogenic microbes was assessed on the basis of colony counts. The rate of antimicrobial activity of the bracket coated with nano-TiO(2-x)N(y) thin film against Streptococcus mutans, Lactobacillus acidophilus, Actinomyces viscous, and Candida albicans was 95.19%, 91.00%, 69.44%, and 98.86%, respectively. Scanning electron microscopy showed that fewer microbes adhered to the surface of this newly designed bracket than to the surface of the normal edgewise bracket. The brackets coated with the N-doped TiO(2-x)N(y) thin film showed high antimicrobial and bacterial adhesive properties against normal oral pathogenic bacterial through visible light, which is effective in prevention of enamel demineralization and gingivitis in orthodontic patients.

Synthesis of cuprous oxide epoxy nanocomposite as an environmentally antimicrobial coating.

Science.gov (United States)

M El Saeed, Ashraf; Abd El-Fattah, M; Azzam, Ahmed M; Dardir, M M; Bader, Magd M

2016-08-01

Cuprous oxide is commonly used as a pigment; paint manufacturers begin to employ cuprous oxide as booster biocides in their formulations, to replace the banned organotins as the principal antifouling compounds. Epoxy coating was reinforced with cuprous oxide nanoparticles (Cu2O NPs). The antibacterial as well as antifungal activity of Cu2O epoxy nanocomposite (Cu2O EN) coating films was investigated. Cu2O NPs were also experimented for antibiofilm and time-kill assay. The thermal stability and the mechanical properties of Cu2O EN coating films were also investigated. The antimicrobial activity results showed slowdown, the growth of organisms on the Cu2O EN coating surface. TGA results showed that incorporating Cu2O NPs into epoxy coating considerably enhanced the thermal stability and increased the char residue. The addition of Cu2O NPs at lower concentration into epoxy coating also led to an improvement in the mechanical resistance such as scratch and abrasion. Cu2O NPs purity was confirmed by XRD. The TEM photograph demonstrated that the synthesized Cu2O NPs were of cubic shape and the average diameter of the crystals was around 25nm. The resulting perfect dispersion of Cu2O NPs in epoxy coating revealed by SEM ensured white particles embedded in the epoxy matrix. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimicrobial polymers - The antibacterial effect of photoactivated nano titanium dioxide polymer composites

Energy Technology Data Exchange (ETDEWEB)

Huppmann, T., E-mail: teresa.huppmann@tum.de; Leonhardt, S., E-mail: stefan.leonhardt@mytum.de, E-mail: erhard.krampe@tum.de; Krampe, E., E-mail: stefan.leonhardt@mytum.de, E-mail: erhard.krampe@tum.de; Wintermantel, E., E-mail: wintermantel@tum.de [Institute of Medical and Polymer Engineering, Technische Universität München (Germany); Yatsenko, S., E-mail: s.yatsenko@skz.de; Radovanovic, I., E-mail: i.radovanovic@skz.de, E-mail: m.bastian@skz.de; Bastian, M., E-mail: i.radovanovic@skz.de, E-mail: m.bastian@skz.de [SKZ- German Plastics Center, Würzburg (Germany)

2014-05-15

To obtain a polymer with antimicrobial properties for medical and sanitary applications nanoscale titanium dioxide (TiO{sub 2}) particles have been incorporated into a medical grade polypropylene (PP) matrix with various filler contents (0 wt %, 2 wt %, 10 wt % and 15 wt %). The standard application of TiO{sub 2} for antimicrobial efficacy is to deposit a thin TiO{sub 2} coating on the surface. In contrast to the common way of applying a coating, TiO{sub 2} particles were applied into the bulk polymer. With this design we want to ensure antimicrobial properties even after application of impact effects that could lead to surface defects. The filler material (Aeroxide® TiO{sub 2} P25, Evonik) was applied via melt compounding and the compounding parameters were optimized with respect to nanoscale titanium dioxide. In a next step the effect of UV-irradiation on the compounds concerning their photocatalytic activity, which is related to the titanium dioxide amount, was investigated. The photocatalytic effect of TiO{sub 2}-PP-composites was analyzed by contact angle measurement, by methylene blue testing and by evaluation of inactivation potential for Escherichia coli (E.coli) bacteria. The dependence of antimicrobial activity on the filler content was evaluated, and on the basis of different titanium dioxide fractions adequate amounts of additives within the compounds were discussed. Specimens displayed a higher photocatalytic and also antimicrobial activity and lower contact angles with increasing titania content. The results suggest that the presence of titania embedded in the PP matrix leads to a surface change and a photocatalytic effect with bacteria killing result.

Erythrocyte membrane-coated nanogel for combinatorial antivirulence and responsive antimicrobial delivery against Staphylococcus aureus infection.

Science.gov (United States)

Zhang, Yue; Zhang, Jianhua; Chen, Wansong; Angsantikul, Pavimol; Spiekermann, Kevin A; Fang, Ronnie H; Gao, Weiwei; Zhang, Liangfang

2017-10-10

We reported an erythrocyte membrane-coated nanogel (RBC-nanogel) system with combinatorial antivirulence and responsive antibiotic delivery for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection. RBC membrane was coated onto the nanogel via a membrane vesicle templated in situ gelation process, whereas the redox-responsiveness was achieved by using a disulfide bond-based crosslinker. We demonstrated that the RBC-nanogels effectively neutralized MRSA-associated toxins in extracellular environment and the toxin neutralization in turn promoted bacterial uptake by macrophages. In intracellular reducing environment, the RBC-nanogels showed an accelerated drug release profile, which resulted in more effective bacterial inhibition. When added to the macrophages infected with intracellular MRSA bacteria, the RBC-nanogels significantly inhibited bacterial growth compared to free antibiotics and non-responsive nanogel counterparts. These results indicate the great potential of the RBC-nanogel system as a new and effective antimicrobial agent against MRSA infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Safe and Effective Ag Nanoparticles Immobilized Antimicrobial NanoNonwovens

DEFF Research Database (Denmark)

Song, Jie; Chen, Menglin; Regina, Viduthalai R.

2012-01-01

and possibility of introduction of secondary pollution. Here, we present a novel strategy to produce a safe and effective antimicrobial nanononwoven material by immobilizing AgNPs on a rigid polymer nanofibrous matrix through simple co-electrospinning of pre-prepaired AgNPs and polystyrene (PS). Distribution...... of the AgNPs on the surface of PS fibers was achieved by tuning fiber diameters during electrospinning. Atomic force microscopy (AFM) analysis revealed that the AgNPs distributed at the fiber surface were still covered by a layer of polymer, which inhibited their antimicrobial activity. UV/ozone treatment...... was thus employed to degrade the polymer coating without loosening the AgNPs, resulting in an active antimicrobial nonwoven against Gram-positive Staphylococcus xylosus. The mechanism based on cellular uptake of silver ions via close contact to the surface of AgNPs is proposed. The novel nanononwoven...

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

Science.gov (United States)

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

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

Antimicrobial and bone-forming activity of a copper coated implant in a rabbit model.

Science.gov (United States)

Prinz, Cornelia; Elhensheri, Mohamed; Rychly, Joachim; Neumann, Hans-Georg

2017-08-01

Current strategies in implant technology are directed to generate bioactive implants that are capable to activate the regenerative potential of the surrounding tissue. On the other hand, implant-related infections are a common problem in orthopaedic trauma patients. To meet both challenges, i.e. to generate a bone implant with regenerative and antimicrobial characteristics, we tested the use of copper coated nails for surgical fixation in a rabbit model. Copper acetate was galvanically deposited with a copper load of 1 µg/mm 2 onto a porous oxide layer of Ti6Al4V nails, which were used for the fixation of a tibia fracture, inoculated with bacteria. After implantation of the nail the concentration of copper ions did not increase in blood which indicates that copper released from the implant was locally restricted to the fracture site. After four weeks, analyses of the extracted implants revealed a distinct antimicrobial effect of copper, because copper completely prevented both a weak adhesion and firm attachment of biofilm-forming bacteria on the titanium implant. To evaluate fracture healing, radiographic examination demonstrated an increased callus index in animals with copper coated nails. This result indicates a stimulated bone formation by releasing copper ions. We conclude that the use of implants with a defined load of copper ions enables both prevention of bacterial infection and the stimulation of regenerative processes.

Antimicrobial effectiveness of bioactive packaging materials from edible chitosan and casein polymers: assessment on carrot, cheese, and salami.

Science.gov (United States)

Moreira, Maria del Rosario; Pereda, Mariana; Marcovich, Norma E; Roura, Sara I

2011-01-01

Antimicrobial packaging is one of the most promising active packaging systems for controlling spoilage and pathogenic microorganisms. In this work, the intrinsic antimicrobial properties of chitosan (CH) were combined with the excellent thermoplastic and film-forming properties of sodium caseinate (SC) to prepare SC/CH film-forming solutions and films. The antimicrobial effectiveness of SC, CH, and SC/CH coatings on the native microfloras of cheese, salami, and carrots was evaluated. In vitro assays through the test tube assay indicated that the most significant antimicrobial effect was achieved by CH and SC/CH solutions on carrot and cheese native microfloras. SC film-forming solutions did not exert antimicrobial activity on any of the native microflora studied. SC, CH, and SC/CH films stored in controlled environments showed that the retention of the antimicrobial action was observed until 5-d storage, at 65% relative humidity in both temperatures (10 °C and 20 °C). In vivo assays were also performed with SC, CH, and SC/CH applied as coatings or wrappers on the 3 food substrates. CH and SC/CH applied at both immersion and wrapper exerted a significant bactericidal action on mesophilic, psychrotrophic, and yeasts and molds counts, showing the 3 microbial populations analyzed a significant reduction (2.0 to 4.5 log CFU/g). An improvement of the bactericidal properties of the CH/SC blend respect to those of the neat CH film is reported. The ionic interaction between both macromolecules enhances its antimicrobial properties. Practical Application: The continuous consumer interest in high quality and food safety, combined with environmental concerns has stimulated the development and study of biodegradable coatings that avoid the use of synthetic materials. Among them, edible coatings, obtained from generally recognized as safe (GRAS) materials, have the potential to reduce weight loss, respiration rate, and improve food appearance and integrity. They can be used in

Comparative performance of a panel of commercially available antimicrobial nanocoatings in Europe

Directory of Open Access Journals (Sweden)

Molling JW

2014-11-01

Full Text Available Johan W Molling, Jacques W Seezink, Birgit EJ Teunissen, Inhua Muijrers-Chen, Paul JA Borm Zuyd University of Applied Sciences, Heerlen, the Netherlands Background: Bacterial resistance against the classic antibiotics is posing an increasing challenge for the prevention and treatment of infections in health care environments. The introduction of antimicrobial nanocoatings with active ingredients provides alternative measures for active killing of microorganisms, through a preventive hygiene approach. Purpose: The purpose of this study was to investigate the antimicrobial activity of a panel of antimicrobial coatings available on the European market. Methods: A comparative, biased selection of commercially available antimicrobial coatings was tested for antimicrobial efficiency. Suppliers were contacted to deliver their coatings on glass and/or stainless steel substrates. In total, 23 coatings from eleven suppliers were received, which were investigated for their effect on the growth of Escherichia coli, using the International Organization for Standardization (ISO 22196 protocol. Results: The majority of nanomaterial-containing coatings (n=13 contained nanosilver (n=12, while only one had photocatalytic TiO2 as the active particle. The differences in antimicrobial activity among all of the coatings, expressed as log reduction values, varied between 1.3 and 6.6, while the variation within the nanomaterial-based group was between 2.0 and 6.2. Although nanosilver coatings were on average very effective in reducing the number of viable bacteria after challenge, the strongest log reduction (6.6 was seen with a coating that has immobilized, covalently bound quaternary ammonium salt in its matrix. Besides these two compounds, coatings containing TiO2, poly(dimethylsiloxane, triclosan, or zinc pyrithione evoked 100% killing of E. coli. Conclusion: Our findings indicate that nanosilver dominates the nanoparticle-based coatings and performs adequately

Effects of chitosan-essential oil coatings on safety and quality of fresh blueberries.

Science.gov (United States)

Sun, Xiuxiu; Narciso, Jan; Wang, Zhe; Ference, Christopher; Bai, Jinhe; Zhou, Kequan

2014-05-01

Chitosan coating plus different essential oils was developed and applied to fresh blueberries in order to find more natural treatments to preserve fresh fruit quality and safety during postharvest storage. Studies were 1st performed in vitro where wild-type Escherichia coli and Penicillium digitatum were grown in suitable media, and then subjected to 6 essential oils. Three compounds, carvacrol (CAR), cinnamaldehyde (CIN), and trans-cinnamaldehyde (ECIN) had high antimicrobial capacity and were selected for an in vivo study for postharvest storage of blueberries. The selected essential oils, 0.5% each, were added into a chitosan solution and coated on fresh blueberries. After storage at 5, 10, and 20 °C for various days, fruit firmness and microbial populations were evaluated. The chitosan coating substantially decreased bacteria and yeasts/molds on the fruit, and all 3 essential oils added to the antimicrobial activities. Further dosage experiments showed that the antimicrobial activity remained even when lowering CAR concentration to 0.1% and ECIN to 0.2%. Chitosan, CAR, and ECIN also maintained fruit firmness. Our results suggest that chitosan coatings containing essential oils are effective in extending the shelf life of fresh blueberries. Blueberries are high-value fruit with strong antioxidant capacity and other health-promoting benefits. However, microbial food safety is an increasing concern, and decay and softening limits their storability. A combination of ≥ 0.1% CAR or ≥ 0.2% ECIN with a chitosan coating effectively reduced softening of fresh berries and decay by inhibiting microbial growth. © 2014 Institute of Food Technologists®

Polydimethylsiloxane-polymethacrylate block copolymers tethering quaternary ammonium salt groups for antimicrobial coating

Energy Technology Data Exchange (ETDEWEB)

Qin, Xiaoshuai; Li, Yancai; Zhou, Fang; Ren, Lixia; Zhao, Yunhui, E-mail: zhaoyunhui@tju.edu.cn; Yuan, Xiaoyan

2015-02-15

Highlights: • A series of PDMS-b-QPDMAEMA block copolymers were synthesized via RAFT polymerization. • The composition and morphology of the copolymer films strongly depended on the content of QPDMAEMA. • Migration of QPDMAEMA blocks toward surface was promoted when contacting with water. • Heterogeneous film surfaces with higher N{sup +} content exhibited more obvious antimicrobial activity. - Abstract: Block copolymers PDMS-b-PDMAEMA were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization involving N,N-dimethylaminoethyl methacrylate (DMAEMA) by using poly(dimethylsiloxane) (PDMS) macro-chain transfer agent. And, the tertiary amino groups in PDMAEMA were quaternized with n-octyliodide to provide quaternary ammonium salts (QPDMAEMA). The well-defined copolymers generated composition variation and morphology evolvement on film surfaces, which were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, and contact angle measurements. The results indicated that the enrichment of QPDMAEMA brought about lower elemental ratios of Si/N on the film surfaces. The surface morphologies evolved with the variations of QPDMAEMA content, and the variation trend of film roughness was exactly opposite to that of water contact angle hysteresis. With regard to structure-antimicrobial relationships, the copolymer films had more evident antimicrobial activity against Gram-positive, Bacillus subtilis, and the surfaces with heterogeneous morphology and higher N{sup +} content presented better antimicrobial activity. The functionalized copolymers based PDMS and quaternary ammonium salts materials have the potential applications as antimicrobial coatings.

Assessing antibacterial effect of filter media coated with silver nanoparticles against Bacillus spp

Directory of Open Access Journals (Sweden)

Mahmood Nafisi Bahabadi

2016-04-01

Full Text Available Background: Nanotechnology is a field of applied science and technology covering a broad range of topics. Use of nanotechnology and especially silver nanoparticles in control of bacterial diseases and infections has been studied in the recent years. The aim of the present study was to investigate the in vitro antibacterial effect of filter media coated with silver nanoparticles against Bacillus spp. Materials and methods: In this research, first, the antibacterial effects of silver nanoparticles against mentioned bacteria were evaluated by microdilution method in Broth medium. After confidence of inhibitory effect of colloidal silver nanoparticles, antibacterial effect of filter media coated with silver nanoparticles was evaluated via in vitro microbiology tests (zone of inhibition test and test tube test. Results: Present study showed that colloidal silver nanoparticles have good antimicrobial effects against tested bacteria, so that MIC and MBC of silver nanoparticles for Bacillus spp. were calculated 3.9 and 31.25 mg/L, respectively. Also significant decrease was observed in bacterial growth after exposure to filter media coated with silver nanoparticles in test tube test and  zone of inhibition test (P≤ 5%. Conclusion: The results of this research indicate that filter media coated with silver nanoparticles have considerable antimicrobial effects; therefore they could possibly be used as excellent antibacterial water filters and would have several applications in other sectors.

New antimicrobial contact catalyst killing antibiotic resistant clinical and waterborne pathogens

Energy Technology Data Exchange (ETDEWEB)

Guridi, A. [Biophysics Unit (CSIC, UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940 Leioa (Spain); Diederich, A.-K. [University Medical Center Freiburg, Division of Infectious Diseases, Hugstetter Strasse 55, 79106 Freiburg (Germany); Biology II, Microbiology, Albert-Ludwigs-University Freiburg, Schänzlestrasse 1, 79104 Freiburg (Germany); Aguila-Arcos, S.; Garcia-Moreno, M. [Biophysics Unit (CSIC, UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940 Leioa (Spain); Blasi, R.; Broszat, M. [University Medical Center Freiburg, Division of Infectious Diseases, Hugstetter Strasse 55, 79106 Freiburg (Germany); Biology II, Microbiology, Albert-Ludwigs-University Freiburg, Schänzlestrasse 1, 79104 Freiburg (Germany); Schmieder, W.; Clauss-Lendzian, E. [Biology II, Microbiology, Albert-Ludwigs-University Freiburg, Schänzlestrasse 1, 79104 Freiburg (Germany); Sakinc-Gueler, T. [University Medical Center Freiburg, Division of Infectious Diseases, Hugstetter Strasse 55, 79106 Freiburg (Germany); Andrade, R. [Advanced Research Facilities (SGIker), University of the Basque Country, UPV/EHU, 48940 Leioa (Spain); Alkorta, I. [Biophysics Unit (CSIC, UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940 Leioa (Spain); Meyer, C.; Landau, U. [Largentec GmbH, Am Waldhaus 32, 14129 Berlin (Germany); Grohmann, E., E-mail: elisabeth.grohmann@googlemail.com [Biophysics Unit (CSIC, UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940 Leioa (Spain); University Medical Center Freiburg, Division of Infectious Diseases, Hugstetter Strasse 55, 79106 Freiburg (Germany); Biology II, Microbiology, Albert-Ludwigs-University Freiburg, Schänzlestrasse 1, 79104 Freiburg (Germany)

2015-05-01

Microbial growth on medical and technical devices is a big health issue, particularly when microorganisms aggregate to form biofilms. Moreover, the occurrence of antibiotic-resistant bacteria in the clinical environment is dramatically growing, making treatment of bacterial infections very challenging. In search of an alternative, we studied a novel antimicrobial surface coating based on micro galvanic elements formed by silver and ruthenium with surface catalytic properties. The antimicrobial coating efficiently inhibited the growth of the nosocomial pathogens Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Enterococcus faecium as demonstrated by the growth inhibition on agar surface and in biofilms of antibiotic resistant clinical E. faecalis, E. faecium, and S. aureus isolates. It also strongly reduced the growth of Legionella in a drinking water pipeline and of Escherichia coli in urine. We postulate a mode of action of the antimicrobial material, which is independent of the release of silver ions. Thus, the novel antimicrobial coating could represent an alternative to combat microbial growth avoiding the toxic side effects of high levels of silver ions on eukaryotic cells. - Highlights: • The novel antimicrobial inhibits growth of clinical staphylococci and enterococci. • The novel antimicrobial inhibits growth of Legionella in drinking water. • A putative mode of action of the antimicrobial coating is presented.

New antimicrobial contact catalyst killing antibiotic resistant clinical and waterborne pathogens

International Nuclear Information System (INIS)

Guridi, A.; Diederich, A.-K.; Aguila-Arcos, S.; Garcia-Moreno, M.; Blasi, R.; Broszat, M.; Schmieder, W.; Clauss-Lendzian, E.; Sakinc-Gueler, T.; Andrade, R.; Alkorta, I.; Meyer, C.; Landau, U.; Grohmann, E.

2015-01-01

Microbial growth on medical and technical devices is a big health issue, particularly when microorganisms aggregate to form biofilms. Moreover, the occurrence of antibiotic-resistant bacteria in the clinical environment is dramatically growing, making treatment of bacterial infections very challenging. In search of an alternative, we studied a novel antimicrobial surface coating based on micro galvanic elements formed by silver and ruthenium with surface catalytic properties. The antimicrobial coating efficiently inhibited the growth of the nosocomial pathogens Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Enterococcus faecium as demonstrated by the growth inhibition on agar surface and in biofilms of antibiotic resistant clinical E. faecalis, E. faecium, and S. aureus isolates. It also strongly reduced the growth of Legionella in a drinking water pipeline and of Escherichia coli in urine. We postulate a mode of action of the antimicrobial material, which is independent of the release of silver ions. Thus, the novel antimicrobial coating could represent an alternative to combat microbial growth avoiding the toxic side effects of high levels of silver ions on eukaryotic cells. - Highlights: • The novel antimicrobial inhibits growth of clinical staphylococci and enterococci. • The novel antimicrobial inhibits growth of Legionella in drinking water. • A putative mode of action of the antimicrobial coating is presented

Deposition of Antimicrobial Copper-Rich Coatings on Polymers by Atmospheric Pressure Jet Plasmas

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Jana Kredl

2016-04-01

Full Text Available Inanimate surfaces serve as a permanent reservoir for infectious microorganisms, which is a growing problem in areas in everyday life. Coating of surfaces with inorganic antimicrobials, such as copper, can contribute to reduce the adherence and growth of microorganisms. The use of a DC operated air plasma jet for the deposition of copper thin films on acrylonitrile butadiene styrene (ABS substrates is reported. ABS is a widespread material used in consumer applications, including hospitals. The influence of gas flow rate and input current on thin film characteristics and its bactericidal effect have been studied. Results from X-ray photoelectron spectroscopy (XPS and atomic force microscopy confirmed the presence of thin copper layers on plasma-exposed ABS and the formation of copper particles with a size in the range from 20 to 100 nm, respectively. The bactericidal properties of the copper-coated surfaces were tested against Staphylococcus aureus. A reduction in growth by 93% compared with the attachment of bacteria on untreated samples was observed for coverage of the surface with 7 at. % copper.

Antimicrobial activity of novel nanostructured Cu-SiO2 coatings prepared by chemical vapour deposition against hospital related pathogens.

Science.gov (United States)

Varghese, Sajnu; Elfakhri, Souad O; Sheel, David W; Sheel, Paul; Bolton, Frederick J Eric; Foster, Howard A

2013-09-05

There is increasing recognition that the healthcare environment acts as an important reservoir for transmission of healthcare acquired infections (HCAI). One method of reducing environmental contamination would be use of antimicrobial materials. The antimicrobial activity of thin silica-copper films prepared by chemical vapour deposition was evaluated against standard strains of bacteria used for disinfectant testing and bacteria of current interest in HCAI. The structure of the coatings was determined using Scanning Electron Microscopy and their hardness and adhesion to the substrate determined. Antimicrobial activity was tested using a method based on BS ISO 22196:2007. The coatings had a pale green-brown colour and had a similar hardness to steel. SEM showed nano-structured aggregates of Cu within a silica matrix. A log10 reduction in viability of >5 could be obtained within 4 h for the disinfectant test strains and within 6 h for producing Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia. Activity against the other hospital isolates was slower but still gave log10 reduction factors of >5 for extended spectrum β-lactamase producing Escherichia coli and >3 for vancomycin resistant Enterococcus faecium, methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa within 24 h. The results demonstrate the importance of testing antimicrobial materials destined for healthcare use against isolates of current interest in hospitals as well as standard test strains. The coatings used here can also be applied to substrates such as metals and ceramics and have potential applications where reduction of microbial environmental contamination is desirable.

Prevention of Biofouling in Hydrocarbons by Antimicrobial Vessel and Pipeline Coating for Cost Savings and an Increase in Safety and Reliability

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Maximilian Lackner

2013-04-01

Full Text Available Hydrocarbons are prone to bacterial and fungal contamination. Bacteria and fungi live and proliferate in water droplets within the fuels and on surfaces surrounding them. This can cause corrosion in oil exploration and production, clogging of fuel lines in aviation and higher emissions in diesel combustion engines to state few examples. State-of-the-art is the addition of biocides to fuels, which is associated with several disadvantages like costs and environmental burden. A novel technology to prevent biofouling in hydrocarbons is presented here. By applying an anti-microbial coating to the surfaces of hydrocarbon processing units, pipelines, and fuel containers, microbial growth can effectively be reduced. The coating can be a paint or varnish, for instance, epoxy resin as already used in aircraft fuel tanks to today. It contains transition metal oxides, thus an acidic surface is produced. This acidic surface was shown to eliminate up to 109 colony forming units per milliliter (CFU.ml-1 of bacteria of the species of agrobacterium tumefaciens and others in diesel, kerosene, and biodiesel, where other anti-microbial coatings based on silver did not perform. The technology has the potential to bring huge cost savings to the oil and gas industry, alongside an increase in safety and equipment reliability.

Applications of nano-structured metal oxides for treatment of arsenic in water and for antimicrobial coatings

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Sadu, Rakesh Babu

Dependency of technology has been increasing radically through cellular phones for communication, data storage devices for education, drinking water purifiers for healthiness, antimicrobial-coated textiles for cleanliness, nanomedicines for deadliest diseases, solar cells for natural power, nanorobots for engineering and many more. Nanotechnology develops many unprecedented products and methodologies with its adroitness in this modern scientific world. Syntheses of nanomaterials play a significant role in the development of technology. Solution combustion and hydrothermal syntheses produce many nanomaterials with different structures and pioneering applications. Nanometal oxides, like titania, silver oxide, manganese oxide and iron oxide have their unique applications in engineering, chemistry and biochemistry. Likewise, this study talks about the syntheses and applications of nanomaterials such as magnetic graphene nanoplatelets (M-Gras) decorated with uniformly dispersed NPs, manganese doped titania nanotubes (Mn-TNTs), and silver doped titania nanopartcles (nAg-TNPs) and their polyurethane based polymer nanocomposite coating (nAg-TiO2 /PU). Basically, M-Gras, and Mn-TNTs were applied for the treatment of arsenic contaminated water, and nAg- TiO2/PU applied for antimicrobial coatings on textiles. Adsorption of arsenic over Mn- TNTs, and M-Gras was discussed while considering all the regulations of arsenic contamination in drinking water and oxidation of arsenic over Mn-TNTs also discussed with the possible surface reactions. Silver doped titania and its polyurethane nanocomposite was coated on polyester fabric and examined the coated fabric for bactericidal activity for gram-negative (E. coli) and gram-positive ( S. epidermidis) bacteria. This study elucidates the development of suitable nanomaterials and their applications to treat or rectify the environmental hazards while following the scientific standards and regulations.

Wound-healing and antimicrobial properties of dichloromethane fraction of Dialium guineense (Wild) fruit coat

OpenAIRE

Nnadi Charles Okeke; K C Udeani Theophilus; Ugwu Linus Onyebuchi

2016-01-01

This research established the scientific bases for the folkloric use of the neglected Dialium guineense fruit coat in wound and microbial infection management in Nigeria. The phytochemical analysis of the crude extract, fractions and sub-fractions was performed by standard methods. Agar well diffusion protocol was adopted for the antimicrobial assay while the wound healing properties was determined by full thickness skin excision wound model. Phytochemical analysis showed high relative propor...

State of the Art of Antimicrobial Edible Coatings for Food Packaging Applications

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Arantzazu Valdés

2017-04-01

Full Text Available The interest for the development of new active packaging materials has rapidly increased in the last few years. Antimicrobial active packaging is a potential alternative to protect perishable products during their preparation, storage and distribution to increase their shelf-life by reducing bacterial and fungal growth. This review underlines the most recent trends in the use of new edible coatings enriched with antimicrobial agents to reduce the growth of different microorganisms, such as Gram-negative and Gram-positive bacteria, molds and yeasts. The application of edible biopolymers directly extracted from biomass (proteins, lipids and polysaccharides or their combinations, by themselves or enriched with natural extracts, essential oils, bacteriocins, metals or enzyme systems, such as lactoperoxidase, have shown interesting properties to reduce the contamination and decomposition of perishable food products, mainly fish, meat, fruits and vegetables. These formulations can be also applied to food products to control gas exchange, moisture permeation and oxidation processes.

Wound-healing and antimicrobial properties of dichloromethane fraction of Dialium guineense (Wild) fruit coat.

Science.gov (United States)

Okeke, Nnadi Charles; Udeani, Theophilus Kc; Onyebuchi, Ugwu Linus

2016-01-01

This research established the scientific bases for the folkloric use of the neglected Dialium guineense fruit coat in wound and microbial infection management in Nigeria. The phytochemical analysis of the crude extract, fractions and sub-fractions was performed by standard methods. Agar well diffusion protocol was adopted for the antimicrobial assay while the wound healing properties was determined by full thickness skin excision wound model. Phytochemical analysis showed high relative proportion of alkaloids (6.05 ± 0.98 %), saponins (3.91 ± 0.02 %) and tannins (1.86 ± 0.05 %). The only active fraction (DF) and sub-fraction (DF-5) were effective against Gram-positive (inhibition zone diameters, IZDs, 8-10 mm and 11-15 mm) and Gram-negative (IZDs, 15-19 mm and 16-21 mm) bacteria and fungi (6-8 mm) compared with 20-24 mm and 18-19 mm of the standard (ciprofloxacin) respectively. Fifty mg/kg of the DF-5 showed nearly equal percentage wound healing post-surgery days to Cicatrin®. The 50 mg/kg dose of DF and DF-5 showed more than 50 % wound healing at 10(th) day post-surgery, 50 mg/kg crude extract showed 54 % on day 14 while distilled water showed 56 % wound healing on day 17 with no sign of infection in all animal groups. All the treatments were significantly (P<0.01) different from control (distilled water) in wound healing by the 10(th) and 17(th) post-surgery days. The studies revealed that the fruit coat, which hitherto was treated as wastes could be explored for antimicrobial and wound healing properties against the backdrop of continually emerging antibiotic resistant strains of microorganisms.

Prior frozen storage enhances the effect of edible coatings against Listeria monocytogenes on cold-smoked salmon during subsequent refrigerated storage.

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Ye, M; Neetoo, H; Chen, H

2011-10-01

Listeria monocytogenes is a major safety concern for ready-to-eat foods. The overall objective of this study was to investigate whether prior frozen storage could enhance the efficacy of edible coatings against L. monocytogenes on cold-smoked salmon during subsequent refrigerated storage. A formulation consisting of sodium lactate (SL, 1·2-2·4%) and sodium diacetate (SD, 0·125-0·25%) or 2·5% Opti.Form (a commercial formulation of SL and SD) was incorporated into each of five edible coatings: alginate, κ-carrageenan, pectin, gelatin and starch. The coatings were applied onto the surface of cold-smoked salmon slices inoculated with L. monocytogenes at a level of 500 CFU cm⁻². In the first phase, the slices were first frozen at -18°C for 6 days and stored at 22°C for 6 days. Alginate, gelatin and starch appeared to be the most effective carriers. In the second phase, cold-smoked salmon slices were inoculated with L. monocytogenes, coated with alginate, gelatin or starch with or without the antimicrobials and stored frozen at -18°C for 12 months. Every 2 months, samples were removed from the freezer and kept at 4°C for 30 days. Prior frozen storage at -18°C substantially enhanced the antilisterial efficacy of the edible coatings with or without antimicrobials during the subsequent refrigerated storage. Plain coatings with ≥ 2 months frozen storage and antimicrobial edible coatings represent an effective intervention to inhibit the growth of L. monocytogenes on cold-smoked salmon. This study demonstrates the effectiveness of the conjunct application of frozen storage and edible coatings to control the growth of L. monocytogenes to enhance the microbiological safety of cold-smoked salmon. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Characterisation and functional properties of antimicrobial bio-barriers formed by natural fibres.

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Tomšič, Brigita; Ilec, Eva; Žerjav, Metka; Hladnik, Aleš; Simončič, Andrej; Simončič, Barbara

2014-10-01

Antimicrobial bio-barriers formed on cotton (CO), silk (SE), and woollen (WO) fabrics were prepared by the application of 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (Si-QAC) at 11 concentrations ranging from 0.5% to 20% using an exhaustion method. The presence of the Si-QAC coating on the treated fabric samples was detected by X-ray photoelectron spectroscopy. The bromophenol blue reagent was used to determine the concentration of quaternary ammonium groups in the coating. The antimicrobial activity of the coated fibres against Gram-negative and Gram-positive bacteria (Escherichia coli and Staphylococcus aureus), fungi (Aspergillus niger and Chaetomium globosum), and soil microflora was assessed using standard microbiological methods. The antimicrobial protection of the fibres increased with increases in the applied concentration of Si-QAC. The fibre type strongly influenced the antimicrobial activity of Si-QAC. Si-QAC was most effective for CO fibres, less effective for WO fibres, and least effective for SE fibres, suggesting that Si-QAC is less accessible for interactions with microorganisms when applied to protein fibres than to cellulose. Although Si-QAC reduced the microbial growth, it did not significantly hinder the biodegradability or sustainability of the coated fibres when exposed to soil microflora. The extent of rotting was more influenced by the morphological and chemical properties of the fibres than by the presence of Si-QAC. Copyright © 2014 Elsevier B.V. All rights reserved.

Antimicrobial peptides on calcium phosphate-coated titanium for the prevention of implant-associated infections

DEFF Research Database (Denmark)

Kazemzadeh-Narbat, Mehdi; Kindrachuk, Jason; Duan, Ke

2010-01-01

of this study was to develop a technique that enables the loading and local delivery of a unique group of cationic antimicrobial peptides (AMP) through implant surfaces. A thin layer of micro-porous calcium phosphate (CaP) coating was processed by electrolytic deposition onto the surface of titanium as the drug......Prevention of implant-associated infections has been one of the main challenges in orthopaedic surgery. This challenge is further complicated by the concern over the development of antibiotic resistance as a result of using traditional antibiotics for infection prophylaxis. The objective......) bacteria with 106-fold reductions of both bacterial strains within 30 min as assessed by measuring colony-forming units (CFU). Repeated CFU assays on the same CaP-Tet213 specimen demonstrated retention of antimicrobial activity by the CaP-Tet213 surfaces through four test cycles. The susceptibility...

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

NARCIS (Netherlands)

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

2013-01-01

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

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

NARCIS (Netherlands)

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

2013-01-01

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

Morphology and inhibition performance of Ag thin film as antimicrobial coating deposited by RF-PVD on 316 L stainless steel

Science.gov (United States)

Purniawan, A.; Khrisna, Y. S. A.; Rasyida, A.; Atmono, T. M.

2018-04-01

Foreign body related infection (FBRIs) is caused by forming biofilm of bacterial colony of medical equipment surfaces. In many cases, the FBRIs is still happened on the surface after medical sterilization process has been performed. In order to avoid the case, surface modification by antimicrobial coating was used. In this work, we present silver (Ag) thin film on 316 L stainless steel substrate surface was deposited using Radio Frequency Sputtering PVD (RF-PVD). The morphology of Ag thin film were characterized using SEM-EDX. Surface roughness of the thin film was measured by AFM. In addition, Kirby Bauer Test in Escherichia coli (E. coli) was conducted in order to evaluate the inhibition performance of the Ag thin film antimicrobial coating. Based on SEM and AFM results show that the particle size is increased from 523 nm to 708 nm and surface roughness from 9 to 20 nm for deposition time 10 minutes to 20 minutes, respectively. In addition, the inhibition layer of the coating is about 29 mm.

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

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Galdiero E

2016-08-01

Full Text Available Emilia Galdiero,1 Antonietta Siciliano,1 Valeria Maselli,1 Renato Gesuele,1 Marco Guida,1 Domenico Fulgione,1 Stefania Galdiero,2 Lucia Lombardi,3 Annarita Falanga2 1Department of Biology, University of Naples “Federico II”, Naples, Italy; 2Department of Pharmacy and Cirpeb, University of Naples “Federico II”, Naples, Italy; 3Department of Experimental Medicine, Second University of Naples, Naples, Italy Abstract: This study attempts to evaluate the antimicrobial activity and the ecotoxicity of quantum dots (QDs alone and coated with indolicidin. To meet this objective, we tested the level of antimicrobial activity on Gram-positive and Gram-negative bacteria, and we designed an ecotoxicological battery of test systems and indicators able to detect different effects using a variety of end points. The antibacterial activity was analyzed against Staphylococcus aureus (ATCC 6538, Pseudomonas aeruginosa (ATCC 1025, Escherichia coli (ATCC 11229, and Klebsiella pneumoniae (ATCC 10031, and the results showed an improved germicidal action of QDs-Ind. Toxicity studies on Daphnia magna indicated a decrease in toxicity for QDs-Ind compared to QDs alone, lack of bioluminescence inhibition on Vibrio fisheri, and no mutations in Salmonella typhimurium TA 100. The comet assay and oxidative stress experiments performed on D. magna showed a genotoxic and an oxidative damage with a dose–response trend. Indolicidin retained its activity when bound to QDs. We observed an enhanced activity for QDs-Ind. The presence of indolicidin on the surface of QDs was able to decrease its QDs toxicity. Keywords: peptide, quantum dots, ecotoxicity, antimicrobial activity, oxidative stress, genotoxicity

Fimbrolide-coated antimicrobial lenses: their in vitro and in vivo effects.

Science.gov (United States)

Zhu, Hua; Kumar, Ajay; Ozkan, Jerome; Bandara, Rani; Ding, Aidong; Perera, Indrani; Steinberg, Peter; Kumar, Naresh; Lao, William; Griesser, Stefani S; Britcher, Leanne; Griesser, Hans J; Willcox, Mark D P

2008-05-01

To examine the ability of contact lenses coated with fimbrolides, inhibitors of bacterial quorum sensing, to prevent microbial adhesion and their safety during short-term clinical assessment. A fimbrolide was covalently attached to commercially available high Dk contact lenses. Subsequently Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens, or Acanthamoeba sp. were added to the lenses and control uncoated contact lenses. Lenses plus microbes were incubated for 24 h, then washed thoroughly to remove non-adherent microbes. Lenses were macerated and resulting slurry plated onto agar plates. After appropriate incubation, the numbers of colony forming units of bacteria (or numbers of Acanthamoeba trophozoites measured using a hemocytometer) from fimbrolide-coated and uncoated lenses were examined. A Guinea Pig model of lens wear was used to assess the safety of lenses worn on a continuous basis for 1 month. In a separate study, 10 subjects wore fimbrolide-coated lenses for 24 h. The responses of the Guinea Pigs and human volunteers to the lenses were assessed by slit lamp examination. The fimbrolides-coated lenses reduced the adhesion of all bacterial strains tested, with reductions occurring of between 67 and 92%. For Acanthamoeba a reduction of 70% was seen. There were no significant differences in ocular responses to fimbrolide-coated lenses compared with controls in either the 1 month animal model or overnight human trial. Fimbrolide-coated lenses show promise as an antibacterial and anti-acanthamoebal coating on contact lenses and appear to be safe when worn on the eye in an animal model.

Antimicrobial and anticancer activity of AgNPs coated with Alphonsea sclerocarpa extract.

Science.gov (United States)

Doddapaneni, Suman Joshi D S; Amgoth, Chander; Kalle, Arunasree M; Suryadevara, Surya Narayana; Alapati, Krishna Satya

2018-03-01

The synthesis and characterization of an aggregate of AgNPs coated with plant extract (PE) from Alphonsea sclerocarpa and its significant antimicrobial activity and inhibition on K562 (blood cancer) cells have been appended in the article. Synthesis of aggregate [(AgNPs)-(PE)] has been followed by a facile eco-friendly approach without using any harmful chemicals. The morphology of an aggregate [(AgNPs)-(PE)] was confirmed by TEM and SEM microscopic characterizations. Properties like solid state, the presence of functional groups, and elemental composition have been characterized through the XRD, FTIR, and EDAX. The biocompatibility of synthesized aggregate of [(AgNPs)-(PE)] was confirmed by the MTT assay. An in vitro cell (HEK293)-based studies were performed for the biocompatibility tests and it is found that the aggregate [(AgNPs)-(PE)] is not harmful to normal/healthy cells. Even though A. sclerocarpa show the antimicrobial (antibacterial and antifungal) activity, it has been further enhanced with the developed aggregate of [(AgNPs)-(PE)]. Furthermore, it has been extended to examine the cellular inhibition on K562 cells and obtained > 75% cell inhibition for 24 h treated cells.

Inactivation of Vegetative Cells, but Not Spores, of Bacillus anthracis, B. cereus, and B. subtilis on Stainless Steel Surfaces Coated with an Antimicrobial Silver- and Zinc-Containing Zeolite Formulation

Science.gov (United States)

Galeano, Belinda; Korff, Emily; Nicholson, Wayne L.

2003-01-01

Stainless steel surfaces coated with paints containing a silver- and zinc-containing zeolite (AgION antimicrobial) were assayed in comparison to uncoated stainless steel for antimicrobial activity against vegetative cells and spores of three Bacillus species, namely, B. anthracis Sterne, B. cereus T, and B. subtilis 168. Under the test conditions (25°C and 80% relative humidity), the zeolite coating produced approximately 3 log10 inactivation of vegetative cells within a 5- to 24-h period, but viability of spores of the three species was not significantly affected. PMID:12839825

Natamycin based sol-gel antimicrobial coatings on polylactic acid films for food packaging.

Science.gov (United States)

Lantano, Claudia; Alfieri, Ilaria; Cavazza, Antonella; Corradini, Claudio; Lorenzi, Andrea; Zucchetto, Nicola; Montenero, Angelo

2014-12-15

In this work a comprehensive study on a new active packaging obtained by a hybrid organic-inorganic coating with antimicrobial properties was carried out. The packaging system based on polylactic acid was realised by sol-gel processing, employing tetraethoxysilane as a precursor of the inorganic phase and polyvinyl alcohol as the organic component, and incorporating natamycin as the active agent. Films with different organic-inorganic ratios (in a range between 1:19 and 1:4) were prepared, and the amount of antimycotic entrapped was found to be modulated by the sol composition, and was between 0.18 and 0.25mg/dm(2). FTIR microspectroscopic measurements were used to characterise the prepared coatings. The antifungal properties of the films were investigated against mould growth on the surface of commercial semi-soft cheese. The release of natamycin from the films to ethanol 50% (v/v) was studied by means of HPLC UV-DAD. The maximal level released was about 0.105 mg/dm(2), which is far below the value allowed by legislation. Copyright © 2014 Elsevier Ltd. All rights reserved.

In Vitro Evaluation of the Antimicrobial Effectiveness and Moisture Binding Properties of Wound Dressings

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Teerapol Srichana

2010-08-01

Full Text Available A variety of silver-coated dressings and some impregnated with other chemicals are now available in the market; however, there have been few studies analyzing their comparative efficacies as antimicrobial agents. Moreover, their properties for retaining an appropriate level of moisture that is critical for effective wound healing have never been reported. Five commercially available silver-containing and chlorhexidine dressings, Urgotul SSD®, Bactigras®, Acticoat®, Askina Calgitrol Ag® and Aquacel Ag®, were tested to determine their comparative antimicrobial effectiveness in vitro against five common wound pathogens, namely methicillin-sensitive and -resistant Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Mepitel®, a flexible polyamide net coated with soft silicone, was used as a control. The zones of inhibition and both the rapidity and the extent of killing of these pathogens were evaluated. All five antimicrobial dressings investigated exerted some bactericidal activity, particularly against E. coli. The spectrum and rapidity of action ranged widely for the different dressings. Acticoat® had a broad spectrum of action against both Gram-positive and -negative bacteria. Other dressings demonstrated a narrower range of bactericidal activities. Regarding the absorption and release of moisture, Askina Calgitrol Ag® absorbed and released the most moisture from the environment. Aquacel Ag® also exhibited good moisture absorption and moisture release, but to a lower degree. The other tested dressings absorbed or released very little moisture. Askina Calgitrol Ag® and Aquacel Ag® are good alternative dressings for treating wounds with high exudates and pus. An understanding of the characteristics of these dressings will be useful for utilizing them for specific requirements under specified conditions.

Functionalized Antimicrobial Composite Thin Films Printing for Stainless Steel Implant Coatings

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Laura Floroian

2016-06-01

Full Text Available In this work we try to address the large interest existing nowadays in the better understanding of the interaction between microbial biofilms and metallic implants. Our aimed was to identify a new preventive strategy to control drug release, biofilm formation and contamination of medical devices with microbes. The transfer and printing of novel bioactive glass-polymer-antibiotic composites by Matrix-Assisted Pulsed Laser Evaporation into uniform thin films onto 316 L stainless steel substrates of the type used in implants are reported. The targets were prepared by freezing in liquid nitrogen mixtures containing polymer and antibiotic reinforced with bioglass powder. The cryogenic targets were submitted to multipulse evaporation by irradiation with an UV KrF* (λ = 248 nm, τFWHM ≤ 25 ns excimer laser source. The prepared structures were analyzed by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and profilometry, before and after immersion in physiological fluids. The bioactivity and the release of the antibiotic have been evaluated. We showed that the incorporated antibiotic underwent a gradually dissolution in physiological fluids thus supporting a high local treatment efficiency. Electrochemical measurements including linear sweep voltammetry and impedance spectroscopy studies were carried out to investigate the corrosion resistance of the coatings in physiological environments. The in vitro biocompatibility assay using the MG63 mammalian cell line revealed that the obtained nanostructured composite films are non-cytotoxic. The antimicrobial effect of the coatings was tested against Staphylococcus aureus and Escherichia coli strains, usually present in implant-associated infections. An anti-biofilm activity was evidenced, stronger against E. coli than the S. aureus strain. The results proved that the applied method allows for the fabrication of implantable biomaterials which shield metal ion release

Functionalized Antimicrobial Composite Thin Films Printing for Stainless Steel Implant Coatings.

Science.gov (United States)

Floroian, Laura; Ristoscu, Carmen; Mihailescu, Natalia; Negut, Irina; Badea, Mihaela; Ursutiu, Doru; Chifiriuc, Mariana Carmen; Urzica, Iuliana; Dyia, Hussien Mohammed; Bleotu, Coralia; Mihailescu, Ion N

2016-06-09

In this work we try to address the large interest existing nowadays in the better understanding of the interaction between microbial biofilms and metallic implants. Our aimed was to identify a new preventive strategy to control drug release, biofilm formation and contamination of medical devices with microbes. The transfer and printing of novel bioactive glass-polymer-antibiotic composites by Matrix-Assisted Pulsed Laser Evaporation into uniform thin films onto 316 L stainless steel substrates of the type used in implants are reported. The targets were prepared by freezing in liquid nitrogen mixtures containing polymer and antibiotic reinforced with bioglass powder. The cryogenic targets were submitted to multipulse evaporation by irradiation with an UV KrF* (λ = 248 nm, τFWHM ≤ 25 ns) excimer laser source. The prepared structures were analyzed by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and profilometry, before and after immersion in physiological fluids. The bioactivity and the release of the antibiotic have been evaluated. We showed that the incorporated antibiotic underwent a gradually dissolution in physiological fluids thus supporting a high local treatment efficiency. Electrochemical measurements including linear sweep voltammetry and impedance spectroscopy studies were carried out to investigate the corrosion resistance of the coatings in physiological environments. The in vitro biocompatibility assay using the MG63 mammalian cell line revealed that the obtained nanostructured composite films are non-cytotoxic. The antimicrobial effect of the coatings was tested against Staphylococcus aureus and Escherichia coli strains, usually present in implant-associated infections. An anti-biofilm activity was evidenced, stronger against E. coli than the S. aureus strain. The results proved that the applied method allows for the fabrication of implantable biomaterials which shield metal ion release and possess

Comparison of Antibacterial Effects of ZnO and CuO Nanoparticles Coated Brackets against Streptococcus Mutans.

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Ramazanzadeh, Baratali; Jahanbin, Arezoo; Yaghoubi, Masoud; Shahtahmassbi, Nasser; Ghazvini, Kiarash; Shakeri, Mohammadtaghi; Shafaee, Hooman

2015-09-01

During the orthodontic treatment, microbial plaques may accumulate around the brackets and cause caries, especially in high-risk patients. Finding ways to eliminate this microbial plaque seems to be essential. The aim of this study was to compare the antibacterial effects of nano copper oxide (CuO) and nano zinc oxide (ZnO) coated brackets against Streptococcus mutans (S.mutans) in order to decrease the risk of caries around the orthodontic brackets during the treatment. Sixty brackets were coated with nanoparticles of ZnO (n=20), CuO (n=20) and CuO-ZnO (n=20). Twelve uncoated brackets constituted the control group. The brackets were bonded to the crowns of extracted premolars, sterilized and prepared for antimicrobial tests (S.mutans ATCC35668). The samples taken after 0, 2, 4, 6 and 24 hours were cultured on agar plates. Colonies were counted 24 hours after incubation. One-way ANOVA and Tukey tests were used for statistical analysis. In CuO and CuO-ZnO coated brackets, no colony growth was seen after two hours. Between 0-6 hours, the mean colony counts were not significantly different between the ZnO and the control group (p>0.05). During 6-24 hours, the growth of S.mutans was significantly reduced by ZnO nanoparticles in comparison with the control group (pbrackets have better antimicrobial effect on S.mutans than ZnO coated brackets.

Inhibition of Listeria monocytogenes ATCC 19115 on ham steak by tea bioactive compounds incorporated into chitosan-coated plastic films

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Vodnar Dan C

2012-07-01

Full Text Available Abstract Background The consumer demands for better quality and safety of food products have given rise to the development and implementation of edible films. The use of antimicrobial films can be a promising tool for controlling L. monocytogenes on ready to eat products. The aim of this study was to develop effective antimicrobial films incorporating bioactive compounds from green and black teas into chitosan, for controlling L. monocytogenes ATCC 19115 on vacuum-packaged ham steak. The effectiveness of these antimicrobial films was evaluated at room temperature (20°C for 10 days and at refrigerated temperature (4°C for 8 weeks. Results The HPLC results clearly show that relative concentrations of catechins and caffeine in green tea ranked EGCG>EGC>CAF>ECG>EC>C while in black tea extracts ranked CAF>EGCG>ECG>EGC>EC>C. The chitosan-coated plastic films incorporating green tea and black tea extracts shows specific markers identified by FTIR. Incorporating natural extracts into chitosan showed that the growth of L monocytogenes ATCC 19115 was inhibited. The efficacy of antimicrobial effect of tea extracts incorporated into chitosan-coated plastic film was dose dependent. However, chitosan-coated films without addition of tea extracts did not inhibit the growth of L. monocytogenes ATCC 19115. Chitosan-coated plastic films incorporating 4% Green tea extract was the most effective antimicrobial, reducing the initial counts from 3.2 to 2.65 log CFU/cm2 during room temperature storage and from 3.2 to 1–1.5 log CFU/cm2 during refrigerated storage. Conclusions Incorporation of tea extracts into the chitosan-coated films considerably enhanced their effectiveness against L. monocytogenes ATCC 19115. 4% Green tea incorporated into chitosan-coated plastic film had a better antilisterial effect than 2% green tea or 2% and 4% black tea. Data from this study would provide new formulation options for developing antimicrobial packaging films using tea

Antimicrobial compounds in tears.

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McDermott, Alison M

2013-12-01

The tear film coats the cornea and conjunctiva and serves several important functions. It provides lubrication, prevents drying of the ocular surface epithelia, helps provide a smooth surface for refracting light, supplies oxygen and is an important component of the innate defense system of the eye providing protection against a range of potential pathogens. This review describes both classic antimicrobial compounds found in tears such as lysozyme and some more recently identified such as members of the cationic antimicrobial peptide family and surfactant protein-D as well as potential new candidate molecules that may contribute to antimicrobial protection. As is readily evident from the literature review herein, tears, like all mucosal fluids, contain a plethora of molecules with known antimicrobial effects. That all of these are active in vivo is debatable as many are present in low concentrations, may be influenced by other tear components such as the ionic environment, and antimicrobial action may be only one of several activities ascribed to the molecule. However, there are many studies showing synergistic/additive interactions between several of the tear antimicrobials and it is highly likely that cooperativity between molecules is the primary way tears are able to afford significant antimicrobial protection to the ocular surface in vivo. In addition to effects on pathogen growth and survival some tear components prevent epithelial cell invasion and promote the epithelial expression of innate defense molecules. Given the protective role of tears a number of scenarios can be envisaged that may affect the amount and/or activity of tear antimicrobials and hence compromise tear immunity. Two such situations, dry eye disease and contact lens wear, are discussed here. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of photocatalytic and hydrophobic coatings on brewery surface microorganisms.

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Priha, O; Laakso, J; Tapani, K; Levänen, E; Kolari, M; Mäntylä, T; Storgårds, E

2011-11-01

The aim of this study was to determine whether process hygiene in the beverage industry could be improved by applying new coating techniques to process surfaces. Photocatalytic titanium dioxide (TiO(2)) and hydrophobic coatings applied to stainless steel with or without added antimicrobial compounds were studied in laboratory attachment tests and in a 15-month process study. No clear reductions in numbers of attached microbes were obtained with photocatalytic coatings, except for coatings to which silver had been added. These TiO(2)+Ag coatings reduced microbial coverage in laboratory studies and in some process samples. Hydrophobic coatings reduced the area coverage of microorganisms in 4-h laboratory studies but did not affect colony counts in laboratory or process studies. The surfaces had changed from hydrophobic into hydrophilic during the process study. The coatings did not mechanically fully withstand process conditions; part of the hydrophobic coatings had peeled off, most of the precipitated Ag had dissolved, and some of the TiO(2) coatings were damaged. In conclusion, functional coatings have potential for reducing microbial loads on beverage industry surfaces, but these coatings need further development.

Antimicrobial coatings based on zinc oxide and orange oil for improved bioactive wound dressings and other applications.

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Rădulescu, Marius; Andronescu, Ecaterina; Cirja, Andreea; Holban, Alina Maria; Mogoantă, LaurenŢiu; Bălşeanu, Tudor Adrian; Cătălin, Bogdan; Neagu, Tiberiu Paul; Lascăr, Ioan; Florea, Denisa Alexandra; Grumezescu, Alexandru Mihai; Ciubuca, Bianca; Lazăr, Veronica; Chifiriuc, Mariana Carmen; Bolocan, Alexandra

2016-01-01

This work presents a novel nano-modified coating for wound dressings and other medical devices with anti-infective properties, based on functionalized zinc oxide nanostructures and orange oil (ZnO@OO). The obtained nanosurfaces were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), selected area electron diffraction (SAED), differential thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The obtained nanocomposite coatings exhibited an antimicrobial activity superior to bare ZnO nanoparticles (NPs) and to the control antibiotic against Staphylococcus aureus and Escherichia coli, as revealed by the lower minimal inhibitory concentration values. For the quantitative measurement of biofilm-embedded microbial cells, a culture-based, viable cell count method was used. The coated wound dressings proved to be more resistant to S. aureus microbial colonization and biofilm formation compared to the uncoated controls. These results, correlated with the good in vivo biodistribution open new directions for the design of nanostructured bioactive coating and surfaces, which can find applications in the medical field, for obtaining improved bioactive wound dressings and prosthetic devices, but also in food packaging and cosmetic industry.

Bioactive Coatings for Orthopaedic Implants—Recent Trends in Development of Implant Coatings

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Bill G. X. Zhang

2014-07-01

Full Text Available Joint replacement is a major orthopaedic procedure used to treat joint osteoarthritis. Aseptic loosening and infection are the two most significant causes of prosthetic implant failure. The ideal implant should be able to promote osteointegration, deter bacterial adhesion and minimize prosthetic infection. Recent developments in material science and cell biology have seen the development of new orthopaedic implant coatings to address these issues. Coatings consisting of bioceramics, extracellular matrix proteins, biological peptides or growth factors impart bioactivity and biocompatibility to the metallic surface of conventional orthopaedic prosthesis that promote bone ingrowth and differentiation of stem cells into osteoblasts leading to enhanced osteointegration of the implant. Furthermore, coatings such as silver, nitric oxide, antibiotics, antiseptics and antimicrobial peptides with anti-microbial properties have also been developed, which show promise in reducing bacterial adhesion and prosthetic infections. This review summarizes some of the recent developments in coatings for orthopaedic implants.

Antidepressants, antimicrobials or both? Gut microbiota dysbiosis in depression and possible implications of the antimicrobial effects of antidepressant drugs for antidepressant effectiveness.

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Macedo, Danielle; Filho, Adriano José Maia Chaves; Soares de Sousa, Caren Nádia; Quevedo, João; Barichello, Tatiana; Júnior, Hélio Vitoriano Nobre; Freitas de Lucena, David

2017-01-15

The first drug repurposed for the treatment of depression was the tuberculostatic iproniazid. At present, drugs belonging to new classes of antidepressants still have antimicrobial effects. Dysbiosis of gut microbiota was implicated in the development or exacerbation of mental disorders, such as major depressive disorder (MDD). Based on the current interest in the gut-brain axis, the focus of this narrative review is to compile the available studies regarding the influences of gut microbiota in behavior and depression and to show the antimicrobial effect of antidepressant drugs. A discussion regarding the possible contribution of the antimicrobial effect of antidepressant drugs to its effectiveness/resistance is included. The search included relevant articles from PubMed, SciELO, LILACS, PsycINFO, and ISI Web of Knowledge. MDD is associated with changes in gut permeability and microbiota composition. In this respect, antidepressant drugs present antimicrobial effects that could also be related to the effectiveness of these drugs for MDD treatment. Conversely, some antimicrobials present antidepressant effects. Both antidepressants and antimicrobials present neuroprotective/antidepressant and antimicrobial effects. Further studies are needed to evaluate the participation of antimicrobial mechanisms of antidepressants in MDD treatment as well as to determine the contribution of this effect to antidepressant resistance. Copyright © 2016 Elsevier B.V. All rights reserved.

Effectiveness of incorporating citric acid in cassava starch edible coatings to preserve quality of Martha tomatoes

Science.gov (United States)

Ambarsari, I.; Oktaningrum, G. N.; Endrasari, R.

2018-01-01

Tomato as an agricultural product is extremely perishable. Coatings of tomatoes with edible starch extend quality and storage life of the fruits. Incorporation of citric acid as antimicrobial agent in the edible starch coatings is expected to preserve the quality of tomatoes during storage. The aim of this study was to verify the effectiveness of citric acid incorporated in cassava starch coating to preserve quality of tomatoes. The edible coatings formula consisted of cassava starch solutions (1; 2; 3%), citric acid (0.5; 1.0%) and glycerol (10%). Tomatoes were dipped to the coating solution for 10 seconds, then air-dried and stored at room temperature during 18 days. All the treatments were carried out in triplicates. Experimental data were analyzed using One Way ANOVA. The results showed that coating treatments did not affect the weight loss, moisture content, color characteristic, carotene and vitamin C content on Martha tomatoes. The low concentration of starch coating on Martha tomatoes are indicated to be the reason why there was no significant difference between coated and coated tomatoes for some parameters. However, incorporating citric acid in cassava starch-based coatings could prevent tomato fruits from firmness reduction and spoilage during storage.

Effect of Chromate and Chromate-Free Organic Coatings on Corrosion Fatigue of an Aluminum Alloy

Science.gov (United States)

2012-02-20

81. 50. T.N. Kalichak, V.I.Pokhmurskii. Influence of Galvanic and Organic Coatings on Fatigue Life of Martensitic Stainless Steel // Fizyko...34Antimicrobial Efficacy of a Silver- Zeolite Matrix Coatings on Stainless Steel ". Ind. Microbiol. Biotechnol, 30 102 (2003). 82. I. M. Zin’, S. B. Lyon, L...to provide corrosion inhibiting properties when incorporated into a primer coatings and paints for iron and steel [38-40]. Regarding the

Reducing ZnO nanoparticles toxicity through silica coating

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Sing Ling Chia

2016-10-01

Full Text Available ZnO NPs have good antimicrobial activity that can be utilized as agents to prevent harmful microorganism growth in food. However, the use of ZnO NPs as food additive is limited by the perceived high toxicity of ZnO NPs in many earlier toxicity studies. In this study, surface modification by silica coating was used to reduce the toxicity of ZnO NPs by significantly reducing the dissolution of the core ZnO NPs. To more accurately recapitulate the scenario of ingested ZnO NPs, we tested our as synthesized ZnO NPs in ingestion fluids (synthetic saliva and synthetic gastric juice to determine the possible forms of ZnO NPs in digestive system before exposing the products to colorectal cell lines. The results showed that silica coating is highly effective in reducing toxicity of ZnO NPs through prevention of the dissociation of ZnO NPs to zinc ions in both neutral and acidic condition. The silica coating however did not alter the desired antimicrobial activity of ZnO NPs to E. coli and S. aureus. Thus, silica coating offered a potential solution to improve the biocompatibility of ZnO NPs for applications such as antimicrobial agent in foods or food related products like food packaging. Nevertheless, caution remains that high concentration of silica coated ZnO NPs can still induce undesirable cytotoxicity to mammalian gut cells. This study indicated that upstream safer-by-design philosophy in nanotechnology can be very helpful in a product development.

Polymeric Coatings for Combating Biocorrosion

Science.gov (United States)

Guo, Jing; Yuan, Shaojun; Jiang, Wei; Lv, Li; Liang, Bin; Pehkonen, Simo O.

2018-03-01

Biocorrosion has been considered as big trouble in many industries and marine environments due to causing great economic loss. The main disadvantages of present approaches to prevent corrosion include being limited by environmental factors, being expensive, inapplicable to field, and sometimes inefficient. Studies show that polymer coatings with anti-corrosion and anti-microbial properties have been widely accepted as a novel and effective approach to preventbiocorrosion. The main purpose of this review is to summarize up the progressive status of polymer coatings used for combating microbially-induced corrosion. Polymers used to synthesize protective coatings are generally divided into three categories: i) traditional polymers incorporated with biocides, ii) antibacterial polymers containing quaternary ammonium compounds, and iii) conductive polymers. The strategies to synthesize polymer coatings resort mainly to grafting anti-bacterial polymers from the metal substrate surface using novel surface-functionalization approaches, such as free radical polymerization, chemically oxidative polymerization and surface-initiated atom transfer radical polymerization, as opposed to the traditional approaches of dip coating or spin coating.

Vegetable-Oil-Based Hyperbranched Polyester-Styrene Copolymer Containing Silver Nanoparticle as Antimicrobial and Corrosion-Resistant Coating Materials

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Manawwer Alam

2013-01-01

Full Text Available Pongamia oil (PO was converted to Pongamia oil hydroxyl (POH via epoxidation process. The esterification of POH with linolenic acid was carried out to form hyperbranched polyester (HBPE, and further styrenation was performed at the conjugated double bond in the chain of linolenic acid. After styrenation, silver nanoparticle was added in different weight percentages (0.1–0.4 wt%. The structural elucidation of POH, HBPE, and HBPE-St was carried out by FT-IR, 1H-NMR, and 13C-NMR spectroscopic techniques. Physicochemical and physicomechanical analyses were performed by standard method. Thermal behavior of the HBPE-St was analyzed by using thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. The coatings of HBPE-St were prepared on mild steel strips. The anticorrosive behavior of HBPE-St resin-based coatings in acid, saline, and tap water was evaluated, and the molecular weight of HBPE-St was determined by gel permeation chromatography (GPC. The antibacterial activities of the HBPE-St copolymers were tested in vitro against bacteria and fungi by disc diffusion method. The HBPE-St copolymers exhibited good antibacterial activities and can be used as antimicrobial and corrosion-resistant coating materials.

Effect of gallic acid/chitosan coating on fresh pork quality in modified atmosphere packaging.

Science.gov (United States)

Fang, Zhongxiang; Lin, Daniel; Warner, Robyn Dorothy; Ha, Minh

2018-09-15

Fresh meat safety and quality is a major concern of consumers in the current food market. The objective of this research was to investigate a newly developed gallic acid/chitosan edible coating on the preservation of fresh pork quality in modified atmosphere package (MAP) stored at 4 °C. The pork loins were coated with 2% chitosan (CHI), 0.2% gallic acid in 2% chitosan (CHI/0.2G), or 0.4% gallic acid in 2% chitosan (CHI/0.4G). Results showed that the antimicrobial activity of the chitosan coating was increased with the incorporation of gallic acid. The CHI/0.2G and CHI/0.4G pork loins also had lower lipid oxidation and myoglobin oxidation. However, the CHI/0.4G sample exhibited a pro-protein oxidation effect, suggesting an optimal concentration of gallic acid should be incorporated. This research provides a practical method in application of gallic acid/chitosan coatings on preservation of fresh pork to improve the safety and quality in MAP environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Switchable antifouling coatings and uses thereof

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Denton, Michele L. Baca; Dirk, Shawn M.; Johnson, Ross Stefan

2017-02-28

The present invention relates to antifouling coatings capable of being switched by using heat or ultraviolet light. Prior to switching, the coating includes an onium cation component having antimicrobial and antibacterial properties. Upon switching, the coating is converted to a conjugated polymer state, and the cationic component is released with any adsorbed biofilm layer. Thus, the coatings herein have switchable and releasable properties. Methods of making and using such coatings are also described.

Antimicrobial properties of metal and metal-halide nanoparticles and their potential applications

Science.gov (United States)

Torrey, Jason Robert

Heavy metals, including silver and copper, have been known to possess antimicrobial properties against bacterial, fungal, and viral pathogens. Metal nanoparticles (aggregations of metal atoms 1-200 nm in size) have recently become the subject of intensive study for their increased antimicrobial properties. In the current studies, metal and metal-halide nanoparticles were evaluated for their antibacterial efficacy. Silver (Ag), silver bromide (AgBr), silver iodide (AgI), and copper iodide (CuI) nanoparticles significantly reduced bacterial numbers of the Gram-negative Pseudomonas aeruginosa and the Gram-positive Staphylococcus aureus within 24 hours and were more effective against P. aeruginosa. CuI nanoparticles were found to be highly effective, reducing both organisms by >4.43 log 10 within 15 minutes at 60 ppm Cu. CuI nanoparticles formulated with different stabilizers (sodium dodecyl sulfate, SDS; polyvinyl pyrrolidone, PVP) were further tested against representative Gram-positive and Gram-negative bacteria, Mycobacteria, a fungus (Candida albicans ), and a non-enveloped virus (poliovirus). Both nanoparticles caused significant reductions in most of the Gram-negative bacteria within five minutes (>5.09-log10). The Gram-positive bacterial species and C. albicans were more sensitive to the CuI-SDS than the CuI-PVP nanoparticles. In contrast, the acid-fast Mycobacterium smegmatis was more resistant to CuI-SDS than CuI-PVP nanoparticles. Poliovirus was more resistant than the other organisms tested except for Mycobacterium fortuitum, which displayed the greatest resistance to CuI nanoparticles. As an example of a real world antimicrobial application, polymer coatings embedded with various concentrations of CuI nanoparticles were tested for antibacterial efficacy against P. aeruginosa and S. aureus. Polyester-epoxy powder coatings were found to display superior uniformity, stability and antimicrobial properties against both organisms (>4.92 log 10 after six hours at

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

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Bakhtawar Ghafoor

2016-01-01

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

In vivo performance of melimine as an antimicrobial coating for contact lenses in models of CLARE and CLPU.

Science.gov (United States)

Cole, Nerida; Hume, Emma B H; Vijay, Ajay K; Sankaridurg, Padmaja; Kumar, Naresh; Willcox, Mark D P

2010-01-01

One strategy to minimize bacteria-associated adverse responses such as microbial keratitis, contact lens-induced acute red eye (CLARE), and contact lens induced peripheral ulcers (CLPUs) that occur with contact lens wear is the development of an antimicrobial or antiadhesive contact lens. Cationic peptides represent a novel approach for the development of antimicrobial lenses. A novel cationic peptide, melimine, was covalently incorporated into silicone hydrogel lenses. Confirmation tests to determine the presence of peptide and anti-microbial activity were performed. Cationic lenses were then tested for their ability to prevent CLPU in the Staphylococcus aureus rabbit model and CLARE in the Pseudomonas aeruginosa guinea pig model. In the rabbit model of CLPU, melimine-coated lenses resulted in significant reductions in ocular symptom scores and in the extent of corneal infiltration (P lenses in the CLARE model showed significant improvement in all ocular response parameters measured, including the percentage of eyes with corneal infiltrates, compared with those observed in the eyes fitted with the control lens (P lenses with the peptide melimine may represent a novel method of prevention of bacterial growth on contact lenses and consequently result in reduction of the incidence and severity of adverse responses due to Gram-positive and -negative bacteria during lens wear.

Synthesis and Characterization of Antimicrobial Nanomaterials

Science.gov (United States)

2013-01-01

and silver coatings on surgical steel .30 Uniform antimicrobial coatings were deposited on surgical stainless steel blades and needles using an...electrophoretic deposition technique. Electrodeposited films firmly adhered to stainless steel surfaces even after extensive washing and retained the...as modified materials for personal hygiene to limit biofilm formation on materials exposed to the environment. Two approaches explored within are

Antimicrobial effect, frictional resistance, and surface roughness of stainless steel orthodontic brackets coated with nanofilms of silver and titanium oxide: a preliminary study.

Science.gov (United States)

Ghasemi, Tania; Arash, Valiollah; Rabiee, Sayed Mahmood; Rajabnia, Ramazan; Pourzare, Amirhosein; Rakhshan, Vahid

2017-06-01

Nano-silver and nano-titanium oxide films can be coated over brackets in order to reduce bacterial aggregation and friction. However, their antimicrobial efficacy, surface roughness, and frictional resistance are not assessed before. Fifty-five stainless-steel brackets were divided into 5 groups of 11 brackets each: uncoated brackets, brackets coated with 60 µm silver, 100 µm silver, 60 µm titanium, and 100 µm titanium. Coating was performed using physical vapor deposition method. For friction test, three brackets from each group were randomly selected and tested. For scanning electron microscopy and atomic-force microscopy assessments, one and one brackets were selected from each group. For antibacterial assessment, six brackets were selected from each group. Of them, three were immediately subjected to direct contact with S. mutans. Colonies were counted 3, 6, 24, and 48 h of contact. The other three were stored in water for 3 months. Then were subjected to a similar direct contact test. Results pertaining to both subgroups were combined. Groups were compared statistically. Mean (SD) friction values of the groups 'control, silver-60, silver-100, titanium-60, and titanium-100' were 0.55 ± 0.14, 0.77 ± 0.08, 0.82 ± 0.11, 1.52 ± 0.24, and 1.57 ± 0.41 N, respectively (p = .0004, Kruskal-Wallis). Titanium frictions were significantly greater than control (p  .05, Dunn). In the uncoated group, colony count increased exponentially within 48 h. The coated groups showed significant reductions in colony count (p < .05, two-way-repeated-measures ANOVA). In conclusions, all four explained coatings reduce surface roughness and bacterial growth. Nano-titanium films are not suitable for friction reduction. Nano-silver results were not conclusive and need future larger studies. © 2016 Wiley Periodicals, Inc.

In vitro methods for the evaluation of antimicrobial surface designs

NARCIS (Netherlands)

Sjollema, Jelmer; Zaat, Sebastian A. J.; Fontaine, Veronique; Ramstedt, Madeleine; Luginbuehl, Reto; Thevissen, Karin; Li, Jiuyi; van der Mei, Henny C.; Busscher, Henk J.

2018-01-01

Bacterial adhesion and subsequent biofilm formation on biomedical implants and devices are a major cause of their failure. As systemic antibiotic treatment is often ineffective, there is an urgent need for antimicrobial biomaterials and coatings. The term "antimicrobial" can encompass different

Application of edible coating with essential oil in food preservation.

Science.gov (United States)

Ju, Jian; Xie, Yunfei; Guo, Yahui; Cheng, Yuliang; Qian, He; Yao, Weirong

2018-03-26

Compared with other types of packaging, edible coatings are becoming more and more popular because of their more environmentally friendly properties and active ingredients carrying ability. The edible coating can reduce the influence of essential oils (EOs) on the flavor of the product and also can prolong the action time of EOs through the slow-release effect, which effectively promote the application of EOs in food. Understanding the different combinations of edible coatings and EOs as well as their antimicrobial effects on different microorganisms will be more powerful and targeted to promote the application of EOs in real food systems. The review focus on the contribution of the combination of EOs and edible coatings (EO-edible coatings) to prolong the shelf life of food products, (1) specifically addressing the main materials used in the preparation of EO-edible coatings and the application of EO-edible coatings in the product, (2) systematically summarizing the main production method of EO-edible coatings, (3) discussing the antiseptic activity of EO-edible coatings on different microorganisms in food.

Antimicrobial activity of tantalum oxide coatings decorated with Ag nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Cao, Huiliang, E-mail: hlc@mail.sic.ac.cn; Meng, Fanhao; Liu, Xuanyong, E-mail: xyliu@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

2016-07-15

Silver plasma immersion ion implantation was used to decorate silver nanoparticles (Ag NPs) on tantalum oxide (TO) coatings. The coatings acted against bacterial cells (Staphylococcus epidermidis) in the dark by disrupting their integrity. The action was independent of silver release and likely driven by the electron storage capability of the Schottky barriers established at the interfaces between Ag NPs and the TO support. Moreover, no apparent side effect on the adhesion and differentiation of rat bone mesenchymal stem cells was detected when using Ag NPs-modified TO coatings. These results demonstrate that decoration of tantalum oxide using Ag NPs could be a promising procedure for improving the antibacterial properties for orthopedic and dental implants.

Application of an active alginate coating to control the growth of Listeria monocytogenes on poached and deli turkey products.

Science.gov (United States)

Juck, Greg; Neetoo, Hudaa; Chen, Haiqiang

2010-09-01

The relatively high prevalence of Listeria monocytogenes in ready-to-eat (RTE) turkey products is of great concern. The overall objective of this study was to develop antimicrobial edible coating formulations to effectively control the growth of this pathogen. The antimicrobials studied were nisin (500IU/g), Novagard CB 1 (0.25%), Guardian NR100 (500ppm), sodium lactate (SL, 2.4%), sodium diacetate (SD, 0.25%), and potassium sorbate (PS, 0.3%). These were incorporated alone or in binary combinations into five edible coatings: alginate, kappa-carrageenan, pectin, xanthan gum, and starch. The coatings were applied onto the surface of home-style poached and processed deli turkey discs inoculated with ~3log CFU/g of L. monocytogenes. The turkey samples were then stored at 22 degrees C for 7days. For poached and processed deli turkey, the coatings were found to be equally effective, with pectin being slightly less effective than the others. The most effective poached turkey treatments seemed to be SL (2.4%)/SD (0.25%) and Nisin (500IU/g)/SL (2.4%), which yielded final populations of 3.0 and 4.9log CFU/g respectively compared to the control which was 7.9log CFU/g. For processed deli turkey, the most effective antimicrobial treatments seemed to be Nisin (500IU/g)/SD (0.25%) and Nisin (500IU/g)/SL (2.4%) with final populations of 1.5 and 1.7log CFU/g respectively compared to the control which was 6.5log CFU/g. In the second phase of the study, home-style poached and store-purchased roasted (deli) turkey inoculated with the pathogen at a level of ~3log CFU/g were coated with alginate incorporating selected antimicrobial combinations and stored for 8weeks at 4 degrees C. Alginate coatings supplemented with SL (2.4%)/PS (0.3%) delayed the growth of L. monocytogenes with final counts reaching 4.3log CFU/g (home-style poached turkey) and 6.5log CFU/g (roasted deli turkey) respectively while the counts in their untreated counterparts were significantly higher (P<0.05) reaching 9

Characterization of a silver-incorporated calcium phosphate film by RBS and its antimicrobial effects

International Nuclear Information System (INIS)

Han, I-H; Lee, I-S; Song, J-H; Lee, M-H; Park, J-C; Lee, G-H; Sun, X-D; Chung, S-M

2007-01-01

A thin calcium phosphate film was synthesized on both commercially pure Ti and Si wafers by electron beam evaporation of hydroxyapatite as an evaporant with simultaneous Ar ion beam bombardments. Silver was introduced into an ion-beam-assisted deposition of a calcium phosphate thin film for antimicrobial effect. The amount of incorporated silver ions was controlled by immersing calcium-phosphate-coated samples in different AgNO 3 concentrations, and Rutherford backscattering spectrometry (RBS) was employed to measure the amounts of substituted silver. The higher concentration of silver in the calcium phosphate film was more effective in reducing the bacteria of Escherichia coli ATCC 8739 and Streptococcus mutans OMZ 65 on contact with respect to controls

Characterization of a silver-incorporated calcium phosphate film by RBS and its antimicrobial effects

Energy Technology Data Exchange (ETDEWEB)

Han, I-H [Institute of Physics and Applied Physics, and Atomic-Scale Surface Science Research Center, Yonsei University, Seou1 120-749 (Korea, Republic of); Lee, I-S [Institute of Physics and Applied Physics, and Atomic-Scale Surface Science Research Center, Yonsei University, Seou1 120-749 (Korea, Republic of); Song, J-H [Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Lee, M-H [Department of Medical Engineering, Yonsei University, Seoul 120-752 (Korea, Republic of); Park, J-C [Department of Medical Engineering, Yonsei University, Seoul 120-752 (Korea, Republic of); Lee, G-H [Korea Institute of Machinery and Materials, Chang-Won 641-010 (Korea, Republic of); Sun, X-D [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Chung, S-M [Implantium Research Center, Seoul 135-879 (Korea, Republic of)

2007-09-15

A thin calcium phosphate film was synthesized on both commercially pure Ti and Si wafers by electron beam evaporation of hydroxyapatite as an evaporant with simultaneous Ar ion beam bombardments. Silver was introduced into an ion-beam-assisted deposition of a calcium phosphate thin film for antimicrobial effect. The amount of incorporated silver ions was controlled by immersing calcium-phosphate-coated samples in different AgNO{sub 3} concentrations, and Rutherford backscattering spectrometry (RBS) was employed to measure the amounts of substituted silver. The higher concentration of silver in the calcium phosphate film was more effective in reducing the bacteria of Escherichia coli ATCC 8739 and Streptococcus mutans OMZ 65 on contact with respect to controls.

Broad spectrum antimicrobial activity of melimine covalently bound to contact lenses.

Science.gov (United States)

Dutta, Debarun; Cole, Nerida; Kumar, Naresh; Willcox, Mark D P

2013-01-07

To develop a stable antimicrobial contact lens, which is effective against the International Organization for Standardization (ISO) panel microorganisms, Acanthamoeba castellanii and drug resistant strains of Pseudomonas aeruginosa and Staphylococcus aureus. Melimine was covalently incorporated into etafilcon A lenses. The amount of peptide present on the lens surface was quantified using amino acid analysis. After coating, the heat stability (121°C), lens surface hydrophobicity (by captive bubble), and in vitro cytotoxicity to mouse L929 cells of the lenses were investigated. Antimicrobial activity against the micro-organisms was evaluated by viable plate count and fluorescence microscopy, measuring the proportion of cell death compared with control lenses with no melimine. The most effective concentration was determined to be 152 ± 44 μg lens(-1) melimine on the lens surface. After coating, lenses were relatively hydrophilic and were nontoxic to mammalian cells. The activity remained high after autoclaving (e.g., 3.1, 3.9, 1.2, and 1.0 log inhibition against P. aeruginosa, S. aureus, A. castellanii, and Fusarium solani, respectively). Fluorescence microscopy confirmed significantly reduced (P bacteria to melimine contact lenses. Viable count confirmed that lenses were active against all the bacteria and fungi from the ISO panel, Acanthamoeba and gave at least 2 log inhibition against all the multidrug resistant S. aureus and P. aeruginosa strains. Melimine may offer excellent potential for development as a broad spectrum antimicrobial coating for contact lenses, showing activity against all the bacterial and fungal ISO panel microorganisms, Acanthamoeba, and antibiotic resistant strains of P. aeruginosa and S. aureus.

Antimicrobial activity and cytocompatibility of silver nanoparticles coated catheters via a biomimetic surface functionalization strategy

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Wu K

2015-12-01

Full Text Available Ke Wu,1 Yun Yang,2,3 Yanmei Zhang,2,3 Jiexi Deng,1 Changjian Lin2,31Department of Cardiology, The Affiliated Dongnan Hospital of Xiamen University, Zhangzhou, 2Department of Medical Materials, Beijing Medical Implant Engineering Research Center, Beijing Naton Technology Group, Beijing, 3State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People’s Republic of ChinaAbstract: Catheter-related bloodstream infections are a significant problem in the clinic and may result in a serious infection. Here, we developed a facile and green procedure for buildup of silver nanoparticles (AgNPs on the central venous catheters (CVCs surface. Inspired by mussel adhesive proteins, dopamine was used to form a thin polydopamine layer and induce AgNPs formation without additional reductants or stabilizers. The chemical and physicochemical properties of AgNPs coated CVCs were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and water contact angle. The Staphylococcus aureus culture experiment was used to study the antibacterial properties. The cytocompatibility was assessed by water soluble tetrazolium salts (WST-1 assay, fluorescence staining, and scanning electron microscopy analysis. The results indicated that the CVCs surface was successfully coated with compact AgNPs. AgNPs were significantly well separated and spherical with a size of 30–50 nm. The density of AgNPs could be modulated by the concentration of silver nitrate solution. The antibacterial activity was dependent on the AgNPs dose. The high dose of AgNPs showed excellent antibacterial activity while associated with increased cytotoxicity. The appropriate density of AgNPs coated CVCs could exhibit improved biocompatibility and maintained evident sterilization effect. It is promising to design mussel-inspired silver releasing CVCs with both

Antimicrobial Peptides in 2014

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Guangshun Wang

2015-03-01

Full Text Available This article highlights new members, novel mechanisms of action, new functions, and interesting applications of antimicrobial peptides reported in 2014. As of December 2014, over 100 new peptides were registered into the Antimicrobial Peptide Database, increasing the total number of entries to 2493. Unique antimicrobial peptides have been identified from marine bacteria, fungi, and plants. Environmental conditions clearly influence peptide activity or function. Human α-defensin HD-6 is only antimicrobial under reduced conditions. The pH-dependent oligomerization of human cathelicidin LL-37 is linked to double-stranded RNA delivery to endosomes, where the acidic pH triggers the dissociation of the peptide aggregate to release its cargo. Proline-rich peptides, previously known to bind to heat shock proteins, are shown to inhibit protein synthesis. A model antimicrobial peptide is demonstrated to have multiple hits on bacteria, including surface protein delocalization. While cell surface modification to decrease cationic peptide binding is a recognized resistance mechanism for pathogenic bacteria, it is also used as a survival strategy for commensal bacteria. The year 2014 also witnessed continued efforts in exploiting potential applications of antimicrobial peptides. We highlight 3D structure-based design of peptide antimicrobials and vaccines, surface coating, delivery systems, and microbial detection devices involving antimicrobial peptides. The 2014 results also support that combination therapy is preferred over monotherapy in treating biofilms.

Antimicrobial stewardship in long term care facilities: what is effective?

OpenAIRE

Nicolle, Lindsay E

2014-01-01

Intense antimicrobial use in long term care facilities promotes the emergence and persistence of antimicrobial resistant organisms and leads to adverse effects such as C. difficile colitis. Guidelines recommend development of antimicrobial stewardship programs for these facilities to promote optimal antimicrobial use. However, the effectiveness of these programs or the contribution of any specific program component is not known. For this review, publications describing evaluation of antimicro...

CrCuAgN PVD nanocomposite coatings: Effects of annealing on coating morphology and nanostructure

Energy Technology Data Exchange (ETDEWEB)

Liu, Xingguang, E-mail: xingguangliu1@gmail.com [Department of Materials Science and Engineering, Sir Robert Hadfield Building, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Iamvasant, Chanon, E-mail: ciamvasant1@sheffield.ac.uk [Department of Materials Science and Engineering, Sir Robert Hadfield Building, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Liu, Chang, E-mail: chang.liu@sheffield.ac.uk [Department of Materials Science and Engineering, Sir Robert Hadfield Building, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Matthews, Allan, E-mail: allan.matthews@manchester.ac.uk [Pariser Building - B24 ICAM, School of Materials, The University of Manchester, Manchester, M13 9PL (United Kingdom); Leyland, Adrian, E-mail: a.leyland@sheffield.ac.uk [Department of Materials Science and Engineering, Sir Robert Hadfield Building, The University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)

2017-01-15

Highlights: • Coatings with nitrogen content up to 16 at.% exhibit a metallic Cr solid solution, even after post-coat annealing at 300 °C and 500 °C. • At higher N/Cr atomic ratios (approaching Cr{sub 2}N stoichiometry), chromium was still inclined to exist in solid solution with nitrogen, rather than as a ceramic nitride phase, even after annealing at 500 °C. • Transportation of Cu and Ag to the surface depends on annealing temperature, annealing duration, nitrogen concentration and ‘global’ Cu + Ag concentration. • Incorporation of copper appears to be a powerful strategy to enhance Ag mobility at low concentration (∼3 at.% Ag in this study) under moderately high service temperature. • A significant decrease in friction coefficient was obtained at room temperature after annealing, or during sliding wear testing at elevated temperature. - Abstract: CrCuAgN PVD nanocomposite coatings were produced using pulsed DC unbalanced magnetron sputtering. This investigation focuses on the effects of post-coat annealing on the surface morphology, phase composition and nanostructure of such coatings. In coatings with nitrogen contents up to 16 at.%, chromium exists as metallic Cr with N in supersaturated solid solution, even after 300 °C and 500 °C post-coat annealing. Annealing at 300 °C did not obviously change the phase composition of both nitrogen-free and nitrogen-containing coatings; however, 500 °C annealing resulted in significant transformation of the nitrogen-containing coatings. The formation of Ag aggregates relates to the (Cu + Ag)/Cr atomic ratio (threshold around 0.2), whereas the formation of Cu aggregates relates to the (Cu + Ag + N)/Cr atomic ratio (threshold around 0.5). The primary annealing-induced changes were reduced solubility of Cu, Ag and N in Cr, and the composition altering from a mixed ultra-fine nanocrystalline and partly amorphous phase constitution to a coarser, but still largely nanocrystalline structure. It was also

A cost-effectiveness analysis of two different antimicrobial stewardship programs

OpenAIRE

Lucas Miyake Okumura; Bruno Salgado Riveros; Monica Maria Gomes-da-Silva; Izelandia Veroneze

2016-01-01

There is a lack of formal economic analysis to assess the efficiency of antimicrobial stewardship programs. Herein, we conducted a cost-effectiveness study to assess two different strategies of Antimicrobial Stewardship Programs. A 30-day Markov model was developed to analyze how cost-effective was a Bundled Antimicrobial Stewardship implemented in a university hospital in Brazil. Clinical data derived from a historical cohort that compared two different strategies of antimicrobial stewardshi...

Incorporation of silver and strontium in hydroxyapatite coating on titanium surface for enhanced antibacterial and biological properties

Energy Technology Data Exchange (ETDEWEB)

Geng, Zhen [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Wang, Renfeng [School of Laboratory Medicine, Tianjin Medical University, Tianjin 300072 (China); Zhuo, Xianglong, E-mail: doctorzhuo@139.com [Department of Spinal Surgery, Liuzhou Worker' s Hospital, Liuzhou 545001 (China); Li, Zhaoyang, E-mail: zyli@tju.edu.cn [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China); Huang, Yongcan [Orthopedics Research Center, Peking University Shenzhen Hospital, Shenzhen 518036 (China); Ma, Lili; Cui, Zhenduo [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Zhu, Shengli [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China); Liang, Yanqin [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Liu, Yunde; Bao, Huijing; Li, Xue; Huo, Qianyu; Liu, Zhili [School of Laboratory Medicine, Tianjin Medical University, Tianjin 300072 (China); Yang, Xianjin, E-mail: xjyang@tju.edu.cn [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China)

2017-02-01

Implant-related infection in primary total joint prostheses has attracted considerable research attention. As a measure to improve the antimicrobial properties of implant materials, silver (Ag) was incorporated into calcium phosphate (CaP) coatings on Titanium (Ti) via a hydrothermal method. Further, strontium (Sr) was added as a binary dopant to reduce the cytotoxicity of Ag in the coatings. Results showed that the CaP coatings were uniformly deposited on Ti with enhanced hydrophilicity and nanoscale surface roughness. Moreover, cell adhesion, proliferation, and differentiation were improved after the CaP coating deposition. The antibacterial properties of the coatings were distinctly improved by the incorporation of Ag, but the cell proliferation and differentiation were significantly decreased. Owing to the incorporation of Sr, the Ag-CaP coatings were able to effectively counteract the negative effects of Ag while maintaining good antibacterial properties. In summary, hydrothermally deposited CaP coatings doped with Ag and Sr exhibit excellent biocompatibility and antimicrobial activity. Thus, such co-doped CaP coatings have considerable potential for orthopaedic implant modification. - Highlights: • Ag- and Sr-substituted HA coating is deposited on titanium by hydrothermal method. • This coating shows a remarkable antibacterial activity and good biocompatibility. • The coating process is simple and suitable for large-scale fabrication. • The possible mechanism of Sr{sup 2+} is proposed.

Antimicrobial stewardship in long term care facilities: what is effective?

Science.gov (United States)

Nicolle, Lindsay E

2014-02-12

Intense antimicrobial use in long term care facilities promotes the emergence and persistence of antimicrobial resistant organisms and leads to adverse effects such as C. difficile colitis. Guidelines recommend development of antimicrobial stewardship programs for these facilities to promote optimal antimicrobial use. However, the effectiveness of these programs or the contribution of any specific program component is not known. For this review, publications describing evaluation of antimicrobial stewardship programs for long term care facilities were identified through a systematic literature search. Interventions included education, guidelines development, feedback to practitioners, and infectious disease consultation. The studies reviewed varied in types of facilities, interventions used, implementation, and evaluation. Comprehensive programs addressing all infections were reported to have improved antimicrobial use for at least some outcomes. Targeted programs for treatment of pneumonia were minimally effective, and only for indicators of uncertain relevance for stewardship. Programs focusing on specific aspects of treatment of urinary infection - limiting treatment of asymptomatic bacteriuria or prophylaxis of urinary infection - were reported to be effective. There were no reports of cost-effectiveness, and the sustainability of most of the programs is unclear. There is a need for further evaluation to characterize effective antimicrobial stewardship for long term care facilities.

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

Science.gov (United States)

Holman, Devin B; Chénier, Martin R

2015-11-01

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

A cost-effectiveness analysis of two different antimicrobial stewardship programs

OpenAIRE

Okumura, Lucas Miyake; Riveros, Bruno Salgado; Gomes-da-Silva, Monica Maria; Veroneze, Izelandia

2016-01-01

Abstract There is a lack of formal economic analysis to assess the efficiency of antimicrobial stewardship programs. Herein, we conducted a cost-effectiveness study to assess two different strategies of Antimicrobial Stewardship Programs. A 30-day Markov model was developed to analyze how cost-effective was a Bundled Antimicrobial Stewardship implemented in a university hospital in Brazil. Clinical data derived from a historical cohort that compared two different strategies of antimicrobial s...

Effect of surface topological structure and chemical modification of flame sprayed aluminum coatings on the colonization of Cylindrotheca closterium on their surfaces

Science.gov (United States)

Chen, Xiuyong; He, Xiaoyan; Suo, Xinkun; Huang, Jing; Gong, Yongfeng; Liu, Yi; Li, Hua

2016-12-01

Biofouling is one of the major problems for the coatings used for protecting marine infrastructures during their long-term services. Regulation in surface structure and local chemistry is usually the key for adjusting antifouling performances of the coatings. In this study, flame sprayed multi-layered aluminum coatings with micropatterned surfaces were constructed and the effects of their surface structure and chemistry on the settlement of typical marine diatoms were investigated. Micropatterned topographical morphology of the coatings was constructed by employing steel mesh as a shielding plate during the coating deposition. A silicone elastomer layer for sealing and interconnection was further brush-coated on the micropatterned coatings. Additional surface modification was made using zwitterionic molecules via DOPA linkage. The surface-modified coatings resist effectively colonization of Cylindrotheca closterium. This is explained by the quantitative examination of a simplified conditioning layer that deteriorated adsorption of bovine calf serum proteins on the zwitterionic molecule-treated samples is revealed. The colonization behaviors of the marine diatoms are markedly influenced by the micropatterned topographical morphology. Either the surface micropatterning or the surface modification by zwitterionic molecules enhances antimicrobial ability of the coatings. However, the combined micropatterned structure and zwitterionic modification do not show synergistic effect. The results give insight into anti-corrosion/fouling applications of the modified aluminum coatings in the marine environment.

Multifunctional Mesoporous Carbon Capsules and their Robust Coatings for Encapsulation of Actives: Antimicrobial and Anti-bioadhesion Functions.

Science.gov (United States)

Mishra, Gargi; Mittal, Nitesh; Sharma, Ashutosh

2017-06-14

We present the synthesis and applications of multifunctional hollow porous carbon spheres with well-ordered pore architecture and ability to encapsulate functional nanoparticles. In the present work, the applications of hollow mesoporous carbon capsules (HMCCs) are illustrated in two different contexts. In the first approach, the hollow capsule core is used to encapsulate silver nanoparticles to impart antimicrobial characteristics. It is shown that silver-loaded HMCCs (concentration ∼100 μg/mL) inhibit the growth and multiplication of bacterial colonies of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) up to 96% and 83%, respectively. In the second part, the fabrication of hierarchical micro- and nanostructured superhydrophobic coatings of HMCCs (without encapsulation with silver nanoparticles) is evaluated for anti-bioadhesion properties. Studies of protein adsorption and microorganism and platelet adhesion have shown a significant reduction (up to 100%) for the HMCC-based superhydrophobic surfaces compared with the control surfaces. Therefore, this unique architecture of HMCCs and their coatings with the ability to encapsulate functional materials make them a promising candidate for a variety of applications.

Studies for improving and formulating of chitosan-based coatings by radiation treatment for fruit preservation

International Nuclear Information System (INIS)

Nguyen Duy Lam; Tran Bang Diep; Tran Minh Quynh; Le Thi Dinh; Nguyen Van Binh; Ho Minh Duc; Vo Van Thuan

2003-01-01

Presented are the investigations: effect of chitosan on fruit - spoiling microorganism and enhancement of antifungal activity by radiation treatment; improvement of antimicrobial activity of chitosan by its derivatives synthesis in combination with radiation treatment; dependence of chitosan antimicrobial activity on molecular weight and distribution of molecular weight; comparative study on the antifungal activity of chitosan of various origins tested in different conditions of radiation treatment and culture mediums; formulation of chitosan membranes and for their properties in mango coating; effectiveness of chitosan-based coatings on fresh fruit appearance and quality during storage; influence of irradiated chitosan on rice plant growing in media contaminated with salt and heavy metals; effect of chitosan solution varied in concentration and molecular weight on seed germination and seedling growth of groundnut, soybean and cabbage. (NHA)

Non-thermal plasma technology for the development of antimicrobial surfaces: a review

Science.gov (United States)

Nikiforov, Anton; Deng, Xiaolong; Xiong, Qing; Cvelbar, U.; DeGeyter, N.; Morent, R.; Leys, Christophe

2016-05-01

Antimicrobial coatings are in high demand in many fields including the biomaterials and healthcare sectors. Within recent progress in nanoscience and engineering at the nanoscale, preparation of nanocomposite films containing metal nanoparticles (such as silver nanoparticles, copper nanoparticles, zinc oxide nanoparticles) is becoming an important step in manufacturing biomaterials with high antimicrobial activity. Controlled release of antibiotic agents and eliminating free nanoparticles are of equal importance for engineering antimicrobial nanocomposite materials. Compared to traditional chemical ‘wet’ methods, plasma deposition and plasma polymerization are promising approaches for the fabrication of nanocomposite films with the advantages of gas phase dry processes, effective use of chemicals and applicability to various substrates. In this article, we present a short overview of state-of-the-art engineering of antimicrobial materials based on the use of non-thermal plasmas at low and atmospheric pressure.

Active edible coating and γ-irradiation as cold combined treatments to assure the safety of broccoli florets (Brassica oleracea L.).

Science.gov (United States)

Ben-Fadhel, Yosra; Saltaji, Sabrina; Khlifi, Mohamed Ali; Salmieri, Stephane; Dang Vu, Khanh; Lacroix, Monique

2017-01-16

The antimicrobial activity of essential oils (EOs), organic acid (OA) salts and natamycin, a natural antifungal produced during fermentation by the bacterium Streptomyces natalensis, was assessed against four pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium and Aspergillus niger). The Minimum Inhibitory Concentration (MIC) of each antimicrobial (AM) was assessed to determine their efficiency on tested microbial species in order to select the most efficient. Then, the interactions between different antimicrobial compounds showing the lowest MIC were determined by the checkerboard method. The most effective antimicrobial formulation showing synergistic or additive effects was then encapsulated in an alginate matrix to protect the antimicrobial efficiency during storage. The effectiveness of the formulation was then evaluated in situ using broccoli as a food model. A combined treatment of active coating and γ-irradiation (0.4 and 0.8kGy) was also done in order to evaluate the possible synergistic effect between treatments. The results of this study allowed the selection of 4 EOs, one OA salt and the natamycin as an antifungal agent exhibiting lower MIC values. The interactive antimicrobial effects between them showed that an antimicrobial formulation composed of 300ppm of lemongrass EO, 5000ppm of sodium diacetate and 80ppm of natamycin resulted in an additive effect against A. niger, E. coli and S. Typhimurium and showing synergistic effect against L. monocytogenes. Finally, in situ analyses showed a synergistic antimicrobial activity between active coating and γ-irradiation and allowed the extension of the shelf-life of ready-to-eat (RTE) broccoli during storage at 4°C. Copyright © 2016 Elsevier B.V. All rights reserved.

Antifungal Paper Based on a Polyborneolacrylate Coating

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Jiangqi Xu

2018-04-01

Full Text Available Paper documents and products are very susceptible to microbial contamination and damage. Fungi are mainly responsible for those biodeterioration processes. Traditional microbicidal strategies constitute a serious health risk even when microbes are dead. Ideal methods should not be toxic to humans and should have no adverse effects on paper, but should own a broad spectrum, good chemical stability and low cost. In this work, we utilize an advanced antimicrobial strategy of surface stereochemistry by applying a coating of a shallow layer of polyborneolacrylate (PBA, resulting in the desired antifungal performance. The PBA-coated paper is challenged with the most common air-borne fungi growing on paper, Aspergillus niger and Penicillium sp. Ten percent by weight of the coating concentration or a 19-μm infiltration of PBA is sufficient to keep the paper spotless. The PBA coating also exhibits significant inhibition of spores’ germination. After PBA coating, both physicochemical properties (paper whiteness, pH, mechanical strength and inking performance display only slight changes, which are acceptable for general utilization. This PBA coating method is nontoxic, rapid and cost-effective, thus demonstrating great potential for applications in paper products.

Integration of antimicrobial pectin-based edible coating and active modified atmosphere packaging to preserve the quality and microbial safety of fresh-cut persimmon (Diospyros kaki Thunb. cv. Rojo Brillante).

Science.gov (United States)

Sanchís, Elena; Ghidelli, Christian; Sheth, Chirag C; Mateos, Milagros; Palou, Lluís; Pérez-Gago, María B

2017-01-01

The greatest hurdle to the commercial marketing of fresh-cut fruits is related to their higher susceptibility to enzymatic browning, tissue softening, and microbial growth. The aim of this study was to test the efficacy of a pectin-based edible coating and low oxygen modified atmosphere packaging (MAP) to control enzymatic browning and reduce microbial growth of fresh-cut 'Rojo Brillante' persimmon. The survival of Escherichia coli, Salmonella enteritidis and Listeria monocytogenes artificially inoculated on fresh-cut fruit was also assessed. The pectin coating was amended with 500 IU mL -1 nisin (NI) as antimicrobial agent and 10 g kg -1 citric acid and 10 g kg -1 calcium chloride as anti-browning and firming agents, respectively. Persimmon slices were dipped in the coating or in water (control) and packed under 5 kPa O 2 (MAP) or in ambient atmosphere for up to 9 days at 5 °C. Microbial growth, package gas composition, colour, firmness, polyphenol oxidase activity, visual quality and overall sensory flavour of persimmon slices were measured during storage. Coating application combined with active MAP significantly reduced the CO 2 emission and O 2 consumption in the package. The coating was effective in reducing browning and also inhibited the growth of mesophilic aerobic bacteria. Coating also reduced the populations of E. coli, S. enteritidis and L. monocytogenes. The combination of the pectin-based edible coating and active MAP proved to be the most effective treatment to maintain the sensory and microbiological quality of persimmon slices for more than 9 days of storage. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Cyclodextrins: A Weapon in the Fight Against Antimicrobial Resistance

Science.gov (United States)

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

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

Disentangling the effects of polymer coatings on silver nanoparticle agglomeration, dissolution, and toxicity to determine mechanisms of nanotoxicity

Science.gov (United States)

Zook, Justin M.; Halter, Melissa D.; Cleveland, Danielle; Long, Stephen E.

2012-10-01

Silver nanoparticles (AgNPs) are frequently coated with a variety of polymers, which may affect various interdependent mechanisms of toxicity or antimicrobial action, including agglomeration and dissolution rates. Here, we systematically measure how citrate, dextran, 5 and 20 kDa poly(ethylene glycol) (PEG), and poly(vinyl pyrrolidone) coatings affect AgNP agglomeration, dissolution, and toxicity. In addition, to disentangle the coatings' effects on agglomeration from their other effects, we produce multiple stable agglomerate sizes of several of the coated 23 nm AgNPs ranging from singly-dispersed to mean agglomerate sizes of several hundred nanometers. These dispersions allow us to independently study the effects of agglomeration and polymer coating on dissolution rate and hemolytic toxicity. We find that both hemolytic toxicity and dissolution rate are highest for the 5 kDa PEG coating, and toxicity and dissolution rate decrease significantly with increasing agglomerate size independent of coating. This correlation between toxicity and dissolution rate suggests that both polymer coating and agglomeration may affect hemolytic toxicity largely through their effects on dissolution. Because both the AgNP dissolution rate and hemolysis decrease only moderately compared to the large increases in agglomerate size, AgNPs' hemolytic toxicity may be caused by their large surface area and consequently high dissolution rate, rather than from other size-specific effects. At the silver concentrations used in this work, silver dissolved from AgNPs is expected to be primarily in the form of AgCl NPs, which are therefore more likely than Ag+ ions to be the primary drivers of hemolytic toxicity. In addition, all AgNPs we tested are much more toxic to horse red blood cells than sheep red blood cells, highlighting the complexity of toxic responses and the need to test toxicity in multiple biological systems.

Disentangling the effects of polymer coatings on silver nanoparticle agglomeration, dissolution, and toxicity to determine mechanisms of nanotoxicity

Energy Technology Data Exchange (ETDEWEB)

Zook, Justin M., E-mail: jzook@nist.gov; Halter, Melissa D.; Cleveland, Danielle; Long, Stephen E. [National Institute of Standards and Technology, Material Measurement Laboratory (United States)

2012-10-15

Silver nanoparticles (AgNPs) are frequently coated with a variety of polymers, which may affect various interdependent mechanisms of toxicity or antimicrobial action, including agglomeration and dissolution rates. Here, we systematically measure how citrate, dextran, 5 and 20 kDa poly(ethylene glycol) (PEG), and poly(vinyl pyrrolidone) coatings affect AgNP agglomeration, dissolution, and toxicity. In addition, to disentangle the coatings' effects on agglomeration from their other effects, we produce multiple stable agglomerate sizes of several of the coated {approx}23 nm AgNPs ranging from singly-dispersed to mean agglomerate sizes of several hundred nanometers. These dispersions allow us to independently study the effects of agglomeration and polymer coating on dissolution rate and hemolytic toxicity. We find that both hemolytic toxicity and dissolution rate are highest for the 5 kDa PEG coating, and toxicity and dissolution rate decrease significantly with increasing agglomerate size independent of coating. This correlation between toxicity and dissolution rate suggests that both polymer coating and agglomeration may affect hemolytic toxicity largely through their effects on dissolution. Because both the AgNP dissolution rate and hemolysis decrease only moderately compared to the large increases in agglomerate size, AgNPs' hemolytic toxicity may be caused by their large surface area and consequently high dissolution rate, rather than from other size-specific effects. At the silver concentrations used in this work, silver dissolved from AgNPs is expected to be primarily in the form of AgCl NPs, which are therefore more likely than Ag{sup +} ions to be the primary drivers of hemolytic toxicity. In addition, all AgNPs we tested are much more toxic to horse red blood cells than sheep red blood cells, highlighting the complexity of toxic responses and the need to test toxicity in multiple biological systems.

FORMATION OF ANTIBACTERIAL EFFECT ON CERAMIC TILE SURFACES

Directory of Open Access Journals (Sweden)

Selçuk ÖZCAN

2017-03-01

Full Text Available Biocidal antimicrobial molecular barrier (BAMB solutions are known to provide antimicrobial effect on the surfaces in industrial applications. However, there has been a lack of scientific reports about the subject in the literature. In this study, in order to impart an antimicrobial surface property on ceramic surfaces, a BAMB solution was applied on gloss fired ceramic wall tile substrates and the surface antimicrobial activity results were compared with that of plain wall tiles (without BAMB application. The ceramic surfaces were cleaned, and stove dried at120°C prior to spray coating with a BAMB solution. The coated substrates were dried in the ambient. The intactness of the coatings was checked with the bromophenol blue test. The microstructural and molecular characterization of the BAMB coated surfaces were carried out with SEM imaging and surface FTIR, respectively. The antimicrobial activity tests of the surfaces were conducted according to ASTM E2180-07 (Standard Test Method for Determining the Activity of Incorporated Antimicrobial Agent in Polymeric or Hydrophobic Materials. The microorganisms used were Staphylococcus aureus (ATCC 6538 and Pseudomonas aeruginosa (ATCC 15442 bacteria. The BAMB coated surfaces showed less flocculent bacterial growth in comparison to uncoated ceramic surfaces leading to the conclusion that the BAMB improved the antimicrobial property.

Antimicrobial effect of essential oils: a systematic review

Directory of Open Access Journals (Sweden)

E Sadeghi

2015-08-01

Full Text Available Regarding the harmful effects of chemical foods preservatives on human body, it is crucial to find out safe antimicrobials among essential oils and herbs. This study aimed to address the effects of different essential oils on various bacterial species through a systematic review. A wide range of published papers in national and international data bases have been searched for the relevant articles. For this reason, the keywords used in searching were: "essential oils in food", "antimicrobial effect" and "vegetable oils". Among 462 retrieved articles, 76 papers were selected for further reviewing based on their title and abstracts. Based on results, the antimicrobial effects of different essential oils on pathogenic and spoilage organisms were compared. Moreover, the most effective as well as the least effective essential oils on microbial growth were identified. It was concluded that essential oils are more effective on gram positive bacteria rather than gram negatives. Besides, it was evident that some essential oils negatively affected the useful organisms such as lactobacilli.

Effects of the Buffer Layers on the Adhesion and Antimicrobial Properties of the Amorphous ZrAlNiCuSi Films

Science.gov (United States)

Chiang, Pai-Tsung; Chen, Guo-Ju; Jian, Sheng-Rui; Shih, Yung-Hui

2011-06-01

To extend the practical applications of the bulk metallic glasses (BMGs), the preparation of the metallic glass coatings on various substrates becomes an important research issue. Among the interfacial properties of the coatings, the adhesion between films and substrates is the most crucial. In this study, amorphous Zr61Al7.5Ni10Cu17.5Si4 (ZrAlNiCuSi) thin films were deposited on SUS304 stainless steel at various sputtering powers by DC sputtering. According to the scratch tests, the introduction of the Cr and Ti buffer layers effectively improves the adhesion between the amorphous thin films and substrate without changing the surface properties, such as roughness and morphology. The antimicrobial results show that the biological activities of these microbes, except Acinetobacter baumannii, are effectively suppressed during the test period.

Antimicrobial Effect of Extracts of Cruciferous Vegetables

Directory of Open Access Journals (Sweden)

Shu-Hui Hu

2004-12-01

Full Text Available The cruciferous vegetables cauliflower, broccoli, cabbage, Chinese radish, Chinese kale, and Chinese kitam were used in this study to prepare water-soluble and methanol-water extracts. Crude protein extracts were also obtained by diethylaminoethyl (DEAE anion exchange chromatography. Water-soluble polysaccharides were prepared by ethanol precipitation followed by ultrafiltration. The antimicrobial effects of all these extracts were evaluated against Gram-positive bacteria, Gram-negative bacteria, and yeast. Crude protein extracts exhibited the greatest antimicrobial activity in monoculture experiments. The antimicrobial effects of cruciferous vegetables were also studied by steeping beef, carrot, and celery in chlorine (10 ppm or citric acid solution (1% containing the crude protein extract (500 ppm for different time periods. Total aerobic plate counts and coliform counts on these foods decreased significantly after 10 minutes in all steeping solutions (p < 0.05.

Pectin-honey coating as novel dehydrating bioactive agent for cut fruit: Enhancement of the functional properties of coated dried fruits.

Science.gov (United States)

Santagata, Gabriella; Mallardo, Salvatore; Fasulo, Gabriella; Lavermicocca, Paola; Valerio, Francesca; Di Biase, Mariaelena; Di Stasio, Michele; Malinconico, Mario; Volpe, Maria Grazia

2018-08-30

In this paper, a novel and sustainable process for the fruit dehydration was described. Specifically, edible coatings based on pectin and honey were prepared and used as dehydrating and antimicrobial agents of cut fruit samples, in this way promoting the fruit preservation from irreversible deteriorative processes. Pectin-honey coating was tested on apple, cantaloupe melon, mango and pineapple. The analysis were performed also on uncoated dehydrated fruits (control). The coated fruit evidenced enhanced dehydration percentage, enriched polyphenol and vitamin C contents, improved antioxidant activity and volatile molecules profile. Moreover, the antimicrobial activity against Pseudomonas and Escherichia coli was assessed. Finally, morphological analysis performed on fruit fractured surface, highlighted the formation of a non-sticky and homogeneous thin layer. These outcomes suggested that the novel fruit dehydration process, performed by using pectin-honey coating, was able to both preserve the safety and quality of dehydrated fruits, and enhance their authenticity and naturalness. Copyright © 2018 Elsevier Ltd. All rights reserved.

Antimicrobial properties of Zr–Cu–Al–Ag thin film metallic glass

Energy Technology Data Exchange (ETDEWEB)

Chen, Hsien-Wei; Hsu, Kai-Chieh; Chan, Yu-Chen [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Duh, Jenq-Gong, E-mail: jgd@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Lee, Jyh-Wei [Department of Materials Engineering, Ming Chi University of Technology, Taipei, Taiwan (China); Center for Thin Film Technologies and Applications, Mingchi University of Technology, Taipei, Taiwan (China); Jang, Jason Shian-Ching [Department of Mechanical Engineering, Institute of Materials Science and Engineering, National Central University, Chung-Li, Taiwan (China); Chen, Guo-Ju [Department of Materials Science and Engineering, I-Shou University, Kaohsiung, Taiwan (China)

2014-06-30

Metallic glass as a prominent class of structure and multifunctional materials exhibits several unique properties in mechanical, electrochemical, and thermal properties. This study aimed to realize the advantage of biomedical application and to promote the attainable size of metallic glasses by the physical vapor deposition. The Zr–Cu–Al–Ag thin film metallic glass (TFMG) was deposited on silicon wafer and SUS304 stainless steel substrates by magnetron sputtering with single target. For X-ray diffraction analysis, all TFMGs revealed typical broad peaks around the incident angle of 30 to 50°, suggesting that coatings possess amorphous structure. In addition, diffuse halo ring patterns of transmission electron microscopy indicated a fine amorphorization for TFMG via sputtering process. The variation of surface roughness showed that TFMG derived from higher power of metallic targets revealed rougher morphology. Besides, the roughness of SUS304 stainless steel substrate significantly reduced from 7 nm to about 1 nm after TFMGs were deposited. The microbes of Candida albicans, Escherichia coli, and Pseudomonas aeruginosa were used and cultivated on the TFMG coatings with medium to investigate the antimicrobial properties. In the incubation experiment, the growth of each microbe was recorded by a digital photography system and the growth area was calculated by image processing software. The growth area of the microbes on the TFMG was mostly smaller than that on SUS304 stainless steel ones within incubation time of 72 h, indicating that the TFMGs reveal better antimicrobial capability. Moreover, the coatings exhibit a particularly long-term antimicrobial effect for P. aeruginosa. In summary, the Zr–Cu–Al–Ag prepared by sputtering with a single target device presented superior glass forming ability, and coatings with copper and silver constituents revealed significantly antimicrobial properties. Besides, the surface roughness is another factor to affect the

Antimicrobial properties of Zr–Cu–Al–Ag thin film metallic glass

International Nuclear Information System (INIS)

Chen, Hsien-Wei; Hsu, Kai-Chieh; Chan, Yu-Chen; Duh, Jenq-Gong; Lee, Jyh-Wei; Jang, Jason Shian-Ching; Chen, Guo-Ju

2014-01-01

Metallic glass as a prominent class of structure and multifunctional materials exhibits several unique properties in mechanical, electrochemical, and thermal properties. This study aimed to realize the advantage of biomedical application and to promote the attainable size of metallic glasses by the physical vapor deposition. The Zr–Cu–Al–Ag thin film metallic glass (TFMG) was deposited on silicon wafer and SUS304 stainless steel substrates by magnetron sputtering with single target. For X-ray diffraction analysis, all TFMGs revealed typical broad peaks around the incident angle of 30 to 50°, suggesting that coatings possess amorphous structure. In addition, diffuse halo ring patterns of transmission electron microscopy indicated a fine amorphorization for TFMG via sputtering process. The variation of surface roughness showed that TFMG derived from higher power of metallic targets revealed rougher morphology. Besides, the roughness of SUS304 stainless steel substrate significantly reduced from 7 nm to about 1 nm after TFMGs were deposited. The microbes of Candida albicans, Escherichia coli, and Pseudomonas aeruginosa were used and cultivated on the TFMG coatings with medium to investigate the antimicrobial properties. In the incubation experiment, the growth of each microbe was recorded by a digital photography system and the growth area was calculated by image processing software. The growth area of the microbes on the TFMG was mostly smaller than that on SUS304 stainless steel ones within incubation time of 72 h, indicating that the TFMGs reveal better antimicrobial capability. Moreover, the coatings exhibit a particularly long-term antimicrobial effect for P. aeruginosa. In summary, the Zr–Cu–Al–Ag prepared by sputtering with a single target device presented superior glass forming ability, and coatings with copper and silver constituents revealed significantly antimicrobial properties. Besides, the surface roughness is another factor to affect the

Disentangling the effects of polymer coatings on silver nanoparticle agglomeration, dissolution, and toxicity to determine mechanisms of nanotoxicity

International Nuclear Information System (INIS)

Zook, Justin M.; Halter, Melissa D.; Cleveland, Danielle; Long, Stephen E.

2012-01-01

Silver nanoparticles (AgNPs) are frequently coated with a variety of polymers, which may affect various interdependent mechanisms of toxicity or antimicrobial action, including agglomeration and dissolution rates. Here, we systematically measure how citrate, dextran, 5 and 20 kDa poly(ethylene glycol) (PEG), and poly(vinyl pyrrolidone) coatings affect AgNP agglomeration, dissolution, and toxicity. In addition, to disentangle the coatings’ effects on agglomeration from their other effects, we produce multiple stable agglomerate sizes of several of the coated ∼23 nm AgNPs ranging from singly-dispersed to mean agglomerate sizes of several hundred nanometers. These dispersions allow us to independently study the effects of agglomeration and polymer coating on dissolution rate and hemolytic toxicity. We find that both hemolytic toxicity and dissolution rate are highest for the 5 kDa PEG coating, and toxicity and dissolution rate decrease significantly with increasing agglomerate size independent of coating. This correlation between toxicity and dissolution rate suggests that both polymer coating and agglomeration may affect hemolytic toxicity largely through their effects on dissolution. Because both the AgNP dissolution rate and hemolysis decrease only moderately compared to the large increases in agglomerate size, AgNPs’ hemolytic toxicity may be caused by their large surface area and consequently high dissolution rate, rather than from other size-specific effects. At the silver concentrations used in this work, silver dissolved from AgNPs is expected to be primarily in the form of AgCl NPs, which are therefore more likely than Ag + ions to be the primary drivers of hemolytic toxicity. In addition, all AgNPs we tested are much more toxic to horse red blood cells than sheep red blood cells, highlighting the complexity of toxic responses and the need to test toxicity in multiple biological systems.

Fat coating of Ca butyrate results in extended butyrate release in the gastrointestinal tract of broilers

NARCIS (Netherlands)

Borne, van den J.J.G.C.; Heetkamp, M.J.W.; Buyse, J.; Niewold, T.A.

2015-01-01

Based on its described beneficial effects on small and large intestinal epithelium, butyrate can be a very good alternative to antimicrobial growth promoters. Effective dietary application requires coating because the majority of uncoated butyrate is purportedly absorbed before reaching the proximal

Investigation of silver impact on hydroxyapatite/lignin coatings electrodeposited on titanium

Energy Technology Data Exchange (ETDEWEB)

Eraković, Sanja; Janković, Ana [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11 000 Belgrade (Serbia); Matić, Ivana Z.; Juranić, Zorica D. [Institute of Oncology and Radiology of Serbia, Pasterova 14, 11 000 Belgrade (Serbia); Vukašinović-Sekulić, Maja [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11 000 Belgrade (Serbia); Stevanović, Tatjana [Département des sciences du bois et de la forêt, Université Laval, 2425 rue de la Terrasse, Québec (Canada); Mišković-Stanković, Vesna, E-mail: vesna@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11 000 Belgrade (Serbia)

2013-11-01

Silver doped hydroxyapatite (HAP) [Ca{sub 9.95}Ag{sub 0.05}(PO{sub 4}){sub 6}(OH){sub 2}] composite coatings with natural polymer organosolv lignin (Lig) were produced by electrophoretic deposition (EPD) on titanium. Coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The corrosion stability of electrodeposited coatings was evaluated in vitro in Kokubo's simulated body fluid (SBF) at 37 °C using electrochemical impedance spectroscopy (EIS). Antimicrobial properties are directly proportional to the rate of silver ions release from the coatings, determined from inductively coupled plasma spectrometry (ICP-AES). The obtained results are in good agreement with viability of pathogenic bacteria strain Staphylococcus aureus TL in suspension, which had completely disappeared after 24 h. Composite Ag/HAP/Lig coatings were confirmed as non-toxic for healthy immunocompetent peripheral blood mononuclear cells (PBMC). - Highlights: • Biocompatibility and antimicrobial properties of Ag/HAP/Lig were investigated. • Ag ions embedded into HAP lattice are released from material upon immersion in SBF. • Strong antibactericidal effect against Staphylococcus aureus. • Non-toxic properties of nanocomposite confirmed against PBMC cells. • Promising result for the future developments of bioactive implant materials.

Antimicrobial action and anti-corrosion effect against sulfate reducing bacteria by lemongrass (Cymbopogon citratus) essential oil and its major component, the citral.

Science.gov (United States)

Korenblum, Elisa; Regina de Vasconcelos Goulart, Fátima; de Almeida Rodrigues, Igor; Abreu, Fernanda; Lins, Ulysses; Alves, Péricles Barreto; Blank, Arie Fitzgerald; Valoni, Erika; Sebastián, Gina V; Alviano, Daniela Sales; Alviano, Celuta Sales; Seldin, Lucy

2013-08-10

The anti-corrosion effect and the antimicrobial activity of lemongrass essential oil (LEO) against the planktonic and sessile growth of a sulfate reducing bacterium (SRB) were evaluated. Minimum inhibitory concentration (MIC) of LEO and its major component, the citral, was 0.17 mg ml-1. In addition, both LEO and citral showed an immediate killing effect against SRB in liquid medium, suggesting that citral is responsible for the antimicrobial activity of LEO against SRB. Transmission electron microscopy revealed that the MIC of LEO caused discernible cell membrane alterations and formed electron-dense inclusions. Neither biofilm formation nor corrosion was observed on carbon steel coupons after LEO treatment. LEO was effective for the control of the planktonic and sessile SRB growth and for the protection of carbon steel coupons against biocorrosion. The application of LEO as a potential biocide for SRB growth control in petroleum reservoirs and, consequently, for souring prevention, and/or as a coating protection against biocorrosion is of great interest for the petroleum industries.

A cost-effectiveness analysis of two different antimicrobial stewardship programs.

Science.gov (United States)

Okumura, Lucas Miyake; Riveros, Bruno Salgado; Gomes-da-Silva, Monica Maria; Veroneze, Izelandia

2016-01-01

There is a lack of formal economic analysis to assess the efficiency of antimicrobial stewardship programs. Herein, we conducted a cost-effectiveness study to assess two different strategies of Antimicrobial Stewardship Programs. A 30-day Markov model was developed to analyze how cost-effective was a Bundled Antimicrobial Stewardship implemented in a university hospital in Brazil. Clinical data derived from a historical cohort that compared two different strategies of antimicrobial stewardship programs and had 30-day mortality as main outcome. Selected costs included: workload, cost of defined daily doses, length of stay, laboratory and imaging resources used to diagnose infections. Data were analyzed by deterministic and probabilistic sensitivity analysis to assess model's robustness, tornado diagram and Cost-Effectiveness Acceptability Curve. Bundled Strategy was more expensive (Cost difference US$ 2119.70), however, it was more efficient (US$ 27,549.15 vs 29,011.46). Deterministic and probabilistic sensitivity analysis suggested that critical variables did not alter final Incremental Cost-Effectiveness Ratio. Bundled Strategy had higher probabilities of being cost-effective, which was endorsed by cost-effectiveness acceptability curve. As health systems claim for efficient technologies, this study conclude that Bundled Antimicrobial Stewardship Program was more cost-effective, which means that stewardship strategies with such characteristics would be of special interest in a societal and clinical perspective. Copyright © 2016 Elsevier Editora Ltda. All rights reserved.

A cost-effectiveness analysis of two different antimicrobial stewardship programs

Directory of Open Access Journals (Sweden)

Lucas Miyake Okumura

2016-05-01

Full Text Available There is a lack of formal economic analysis to assess the efficiency of antimicrobial stewardship programs. Herein, we conducted a cost-effectiveness study to assess two different strategies of Antimicrobial Stewardship Programs. A 30-day Markov model was developed to analyze how cost-effective was a Bundled Antimicrobial Stewardship implemented in a university hospital in Brazil. Clinical data derived from a historical cohort that compared two different strategies of antimicrobial stewardship programs and had 30-day mortality as main outcome. Selected costs included: workload, cost of defined daily doses, length of stay, laboratory and imaging resources used to diagnose infections. Data were analyzed by deterministic and probabilistic sensitivity analysis to assess model's robustness, tornado diagram and Cost-Effectiveness Acceptability Curve. Bundled Strategy was more expensive (Cost difference US$ 2119.70, however, it was more efficient (US$ 27,549.15 vs 29,011.46. Deterministic and probabilistic sensitivity analysis suggested that critical variables did not alter final Incremental Cost-Effectiveness Ratio. Bundled Strategy had higher probabilities of being cost-effective, which was endorsed by cost-effectiveness acceptability curve. As health systems claim for efficient technologies, this study conclude that Bundled Antimicrobial Stewardship Program was more cost-effective, which means that stewardship strategies with such characteristics would be of special interest in a societal and clinical perspective.

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

Science.gov (United States)

de Rapper, Stephanie; Viljoen, Alvaro

2016-01-01

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

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

Directory of Open Access Journals (Sweden)

Stephanie de Rapper

2016-01-01

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

Antimicrobial coatings — obtaining and characterization

Indian Academy of Sciences (India)

Author Affiliations. Cornelia Guran1 Alexandra Pica2 Denisa Ficai1 Anton Ficai1 Cezar Comanescu1. Politehnica University of Bucharest, 1-7 Polizu St, Bucharest 011061, Romania; Research Institute for Advanced Coating, 49 A Theodor Pallady Bd, Bucharest 032258, Romania ...

Effect of Encapsulation on Antimicrobial Activity of Herbal Extracts with Lysozyme

Directory of Open Access Journals (Sweden)

Petra Matouskova

2016-01-01

Full Text Available Resistance of microorganisms to antibiotics has increased. The use of natural components with antimicrobial properties can be of great significance to reduce this problem. The presented work is focused on the study of the effect of encapsulation of selected plant and animal antimicrobial substances (herbs, spices, lysozyme and nisin on their activity and stability. Antimicrobial components were packaged into liposomes and polysaccharide particles (alginate, chitosan and starch. Antimicrobial activity was tested against two Gram-positive (Bacillus subtilis and Micrococcus luteus and two Gram-negative (Escherichia coli and Serratia marcescens bacteria. Encapsulation was successful in all types of polysaccharide particles and liposomes. The prepared particles exhibited very good long-term stability, especially in aqueous conditions. Antimicrobial activity was retained in all types of particles. Liposomes with encapsulated herb and spice extracts exhibited very good inhibitory effect against all tested bacterial strains. Most of herbal extracts had very good antimicrobial effect against the tested Gram-negative bacterial strains, while Gram-positive bacteria were more sensitive to lysozyme particles. Thus, particles with co-encapsulated herbs and lysozyme are more active against different types of bacteria, and more stable and more effective during long-term storage. Particles with encapsulated mixture of selected plant extracts and lysozyme could be used as complex antimicrobial preparation with controlled release in the production of food and food supplements, pharmaceutical and cosmetic industries.

Characterization of antimicrobial properties on the growth of S. aureus of novel renewable blends of gliadins and chitosan of interest in food packaging and coating applications.

Science.gov (United States)

Fernandez-Saiz, P; Lagaron, J M; Hernandez-Muñoz, P; Ocio, M J

2008-05-10

The biocide properties of chitosan-based materials have been known for many years. However, typical antimicrobial formulations of chitosan, mostly chitosonium salts, are known to be very water sensitive materials which may impair their use in many application fields such as food packaging or food coating applications. This first work reports on the development and characterization of the antimicrobial properties of novel fully renewable blends of chitosan with more water-resistant gliadin proteins isolated from wheat gluten. Chitosan release to the nutrient broth from a wide range of blends was studied making use of the ninhydrin method. The results indicated that both pure chitosan and its blends with gliadins presented significant antimicrobial activity, which increased with increasing the amount of chitosan in the composite formulation as expected. The gliadins-chitosan blends showed good transparency and film-forming properties and better water resistance than pure chitosan. The release tests revealed that dissolution of the biocide glucosamine groups, i.e. the chitosan water soluble fractions, also increased with the amount of chitosan present in the formulation. The release of these groups was for the first time directly correlated with the antimicrobial properties exhibited by the blends. Thus, incorporation of chitosan into an insoluble biopolymer matrix was revealed as a very feasible strategy to generate novel chitosan-based antimicrobial materials with potential advantages, for instance active food packaging applications.

Membrane interactions and antimicrobial effects of layered double hydroxide nanoparticles

DEFF Research Database (Denmark)

Malekkhaiat Häffner, S; Nyström, L; Nordström, R

2017-01-01

Membrane interactions are critical for the successful use of inorganic nanoparticles as antimicrobial agents and as carriers of, or co-actives with, antimicrobial peptides (AMPs). In order to contribute to an increased understanding of these, we here investigate effects of particle size (42-208 nm...... into size-dependent synergistic effects with the antimicrobial peptide LL-37. Due to strong interactions with anionic lipopolysaccharide and peptidoglycan layers, direct membrane disruption of both Gram-negative and Gram-positive bacteria is suppressed. However, LDH nanoparticles cause size-dependent charge...

Plasma deposition of antimicrobial coating on organic polymer

Science.gov (United States)

Rżanek-Boroch, Zenobia; Dziadczyk, Paulina; Czajkowska, Danuta; Krawczyk, Krzysztof; Fabianowski, Wojciech

2013-02-01

Organic materials used for packing food products prevent the access of microorganisms or gases, like oxygen or water vapor. To prolong the stability of products, preservatives such as sulfur dioxide, sulfites, benzoates, nitrites and many other chemical compounds are used. To eliminate or limit the amount of preservatives added to food, so-called active packaging is sought for, which would limit the development of microorganisms. Such packaging can be achieved, among others, by plasma modification of a material to deposit on its surface substances inhibiting the growth of bacteria. In this work plasma modification was carried out in barrier discharge under atmospheric pressure. Sulfur dioxide or/and sodium oxide were used as the coating precursors. As a result of bacteriological studies it was found that sulfur containing coatings show a 16% inhibition of Salmonella bacteria growth and 8% inhibition of Staphylococcus aureus bacteria growth. Sodium containing coatings show worse (by 10%) inhibiting properties. Moreover, films with plasma deposited coatings show good sealing properties against water vapor. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Ségui.

Ionizing radiation effect on central venous catheters (CVC) of polyurethane coatings with silver nanoparticles

International Nuclear Information System (INIS)

Heilman, Sonia; Silva, Leonardo G.A.; Hewer, Thiago L.R.; Souza, Michele L.

2015-01-01

The present work aimed to study the use of ionizing radiation for coating of silver nanoparticles on central polyurethane catheters, providing reduction of infections associated with contamination of catheters introduced into the bloodstream. Silver nanoparticles have physical, chemical and biological properties only when compared to metal on a macroscopic scale, and have been used in the medical field because of its remarkable antimicrobial activity. Titanium dioxide nanoparticles obtained by the sol gel method were used as the coating catheters for subsequent impregnation of silver nanoparticles with ionizing radiation at doses of 25 and 50 kGy. A Raman spectrometry was used to identify the polymorph of titanium oxide, rutile. In trials with (ICP OES) were evaluated amounts of titanium and silver coated catheters in titanium oxide and silver.(author)

Nanoparticulate zinc oxide as a coating material for orthopedic and dental implants.

Science.gov (United States)

Memarzadeh, Kaveh; Sharili, Amir S; Huang, Jie; Rawlinson, Simon C F; Allaker, Robert P

2015-03-01

Orthopedic and dental implants are prone to infection. In this study, we describe a novel system using zinc oxide nanoparticles (nZnO) as a coating material to inhibit bacterial adhesion and promote osteoblast growth. Electrohydrodynamic atomisation (EHDA) was employed to deposit mixtures of nZnO and nanohydroxyapatite (nHA) onto the surface of glass substrates. Nano-coated substrates were exposed to Staphylococcus aureus suspended in buffered saline or bovine serum to determine antimicrobial activity. Our results indicate that 100% nZnO and 75% nZnO/25% nHA composite-coated substrates have significant antimicrobial activity. Furthermore, osteoblast function was explored by exposing cells to nZnO. UMR-106 cells exposed to nZnO supernatants showed minimal toxicity. Similarly, MG-63 cells cultured on nZnO substrates did not show release of TNF-α and IL-6 cytokines. These results were reinforced by both proliferation and differentiation studies which revealed that a substrate coated with exclusively nZnO is more efficient than composite surface coatings. Finally, electron and light microscopy, together with immunofluorescence staining, revealed that all cell types tested, including human mesenchymal cell (hMSC), were able to maintain normal cell morphology when adhered onto the surface of the nano-coated substrates. Collectively, these findings indicate that nZnO can, on its own, provide an optimal coating for future bone implants that are both antimicrobial and biocompatible. © 2014 Wiley Periodicals, Inc.

Gum acacia coating with garlic and cinnamon as an alternate ...

African Journals Online (AJOL)

Madhumita

The antibacterial activity of gum arabic coating with ... Key words: Gum acacia coating, garlic, cinnamon, antioxidant, antimicrobial, meat, ... cinnamaldehyde and eugenol inhibit production of an ... antioxidant activity because these two properties are ... temperatures .... activity of these spices but no report on its application.

Surface-engineered core-shell nano-size ferrites and their antimicrobial activity

International Nuclear Information System (INIS)

Baraliya, Jagdish D.; Joshi, Hiren H.

2014-01-01

We report the results of biological study on core-shell structured MFe 2 O 4 (where M = Co, Mn, Ni) nanoparticles and influence of silica- DEG dual coating on their antimicrobial activity. Spherical MFe 2 O 4 nanoparticles were prepared via a Co-precipitation method. The microstructures and morphologies of these nanoparticles were studied by x-ray diffraction and FTIR. The antimicrobial activity study carried out in nutrient agar medium with addition of antimicrobial synthesis compound which is tested for its activity against different types of bacteria

Review of antimicrobial and antioxidative activities of chitosans in food.

Science.gov (United States)

Friedman, Mendel; Juneja, Vijay K

2010-09-01

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

The Utilization of Ocimum sanctum L. Essential Oil for Antimicrobial Edible Packaging and Its Application for Aloe Vera Dodol

Directory of Open Access Journals (Sweden)

Pramono Putro Utomo

2013-12-01

Full Text Available Aloe vera dodol is a traditional food of West Kalimantan that has short shelf life because of its microbial activity. Antimicrobial edible packaging could be used to maintain the quality of packaged food product actively.The purpose of this study is to prolong the shelf life of food products using antimicrobial edible packaging from durian peel and basil (Ocimum sanctum L. essential oil. The research was conducted through 4 phases,i.e. the extraction of pectin from durian peel, basil essential oil distillation, Aspergillus flavus inhibition assay, and antimicrobial edible coating production incorporated with Ocimum sanctum L. essential oil. The results showed that pectin extracted from durian peel at pH 4.5 could give yield of 5.9% with a clear coat (Colourless.The concentration of Ocimum sanctum L. essential oil by 0.6% could inhibit the growth of Aspergillus flavus and prolong the shelf life when applied as an antimicrobial ingredient in edible coating.

Active Packaging Coatings

Directory of Open Access Journals (Sweden)

Luis J. Bastarrachea

2015-11-01

Full Text Available Active food packaging involves the packaging of foods with materials that provide an enhanced functionality, such as antimicrobial, antioxidant or biocatalytic functions. This can be achieved through the incorporation of active compounds into the matrix of the commonly used packaging materials, or by the application of coatings with the corresponding functionality through surface modification. The latter option offers the advantage of preserving the packaging materials’ bulk properties nearly intact. Herein, different coating technologies like embedding for controlled release, immobilization, layer-by-layer deposition, and photografting are explained and their potential application for active food packaging is explored and discussed.

Effect of sodium alginate coating incorporated with nisin, Cinnamomum zeylanicum, and rosemary essential oils on microbial quality of chicken meat and fate of Listeria monocytogenes during refrigeration.

Science.gov (United States)

Raeisi, Mojtaba; Tabaraei, Alijan; Hashemi, Mohammad; Behnampour, Nasser

2016-12-05

The present study was conducted to preserve the microbial quality of chicken meat fillets during storage time by using sodium alginate active coating solutions incorporated with different natural antimicrobials including nisin, Cinnamomum zeylanicum (cinnamon), and rosemary essential oils (EOs) which were added individually and in combination. The samples were stored in refrigeration condition for 15days and were analyzed for total viable count, Enterobacteriaceae count, lactic acid bacteria count, Pseudomonas spp. count, psychrotrophic count, and yeast and mold count, as well as fate of inoculated Listeria monocytogenes at 3-day intervals. Results indicated that values of tested microbial indicators in all samples increased during storage. Antimicrobial agents, when used in combination, had stronger effect in preserving the microbial quality of chicken meat samples rather than their individual use and the strongest effect was observed in samples coated with alginate solution containing both cinnamon and rosemary EOs (CEO+REO). However, all treatments significantly inhibited microbial growth when compared to the control (Ppreservatives is recommended in meat products especially in chicken meats. Copyright © 2016. Published by Elsevier B.V.

Effect of coating current density on the wettability of electrodeposited copper thin film on aluminum substrate

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Arun Augustin

2016-09-01

Full Text Available Copper is the only one solid metal registered by the US Environmental Protection Agency as an antimicrobial touch surface. In touch surface applications, wettability of the surface has high significance. The killing rate of the harmful microbes depends on the wetting of pathogenic solution. Compared to the bulk copper, coated one on aluminum has the advantage of economic competitiveness and the possibility of manufacturing complex shapes. In the present work, the copper coating on the aluminum surface has successfully carried out by electrodeposition using non cyanide alkaline bath. To ensure good adhesion strength, the substrate has been pre-zincated prior to copper deposition. The coating current density is one of the important parameters which determine the nucleation density of the copper on the substrate. To understand the effect of current density on wettability, the coating has done at different current densities in the range of 3 A dm−2 to 9 A dm−2 for fixed time interval. The grain size has been measured from TEM micrographs and showed that as current density increases, grain size reduces from 62 nm to 35 nm. Since the grain size reduces, grain boundary volume has increases. As a result the value of strain energy (calculated by Williamson–Hall method has increased. The density of nodular morphology observed in SEM analysis has been increased with coating current density. Further, wettability studies with respect to double distilled water on the electrodeposited copper coatings which are coated at different current densities are carried out. At higher current density the coating is more wettable by water because at these conditions grain size of the coating decreases and morphology of grain changes to a favorable dense nodularity.

Antimicrobial activity of thin solid films of silver doped hydroxyapatite prepared by sol-gel method.

Science.gov (United States)

Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

2014-01-01

In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x(Ag) = 0.5 are effective against E. coli and S. aureus after 24 h.

Antimicrobial Activity of Thin Solid Films of Silver Doped Hydroxyapatite Prepared by Sol-Gel Method

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Simona Liliana Iconaru

2014-01-01

Full Text Available In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM with energy Dispersive X-ray attachment (X-EDS, Fourier transform infrared spectroscopy (FT-IR, and glow discharge optical emission spectroscopy (GDOES. These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with xAg=0.5 are effective against E. coli and S. aureus after 24 h.

Antimicrobial Activity of Thin Solid Films of Silver Doped Hydroxyapatite Prepared by Sol-Gel Method

Science.gov (United States)

Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

2014-01-01

In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x Ag = 0.5 are effective against E. coli and S. aureus after 24 h. PMID:24523630

One-Step Synthesis of Silver Nanoparticles on Polydopamine-Coated Sericin/Polyvinyl Alcohol Composite Films for Potential Antimicrobial Applications

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Rui Cai

2017-04-01

Full Text Available Silk sericin has great potential as a biomaterial for biomedical applications due to its good hydrophilicity, reactivity, and biodegradability. To develop multifunctional sericin materials for potential antibacterial application, a one-step synthesis method for preparing silver nanoparticles (AgNPs modified on polydopamine-coated sericin/polyvinyl alcohol (PVA composite films was developed. Polydopamine (PDA acted as both metal ion chelating and reducing agent to synthesize AgNPs in situ on the sericin/PVA composite film. Scanning electron microscopy and energy dispersive spectroscopy analysis revealed that polydopamine could effectively facilitate the high-density growth of AgNPs as a 3-D matrix. X-ray diffractometry studies suggested the synthesized AgNPs formed good face-centered cubic crystalline structures. Contact angle measurement and mechanical test indicated AgNPs modified PDA-sericin/PVA composite film had good hydrophilicity and mechanical property. The bacterial growth curve and inhibition zone assays showed the AgNPs modified PDA-sericin/PVA composite film had long-term antibacterial activities. This work develops a new method for the preparation of AgNPs modified PDA-sericin/PVA film with good hydrophilicity, mechanical performance and antibacterial activities for the potential antimicrobial application in biomedicine.

Performance evaluation of nanoclay enriched anti-microbial hydrogels for biomedical applications

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Sonali Karnik

2016-02-01

Full Text Available A major factor contributing to the failure of orthopedic and orthodontic implants is post-surgical infection. Coating metallic implant surfaces with anti-microbial agents has shown promise but does not always prevent the formation of bacterial biofilms. Furthermore, breakdown of these coatings within the human body can cause release of the anti-microbial drugs in an uncontrolled or unpredictable fashion. In this study, we used a calcium alginate and calcium phosphate cement (CPC hydrogel composite as the base material and enriched these hydrogels with the anti-microbial drug, gentamicin sulfate, loaded within a halloysite nanotubes (HNTs. Our results demonstrate a sustained and extended release of gentamicin from hydrogels enriched with the gentamicin-loaded HNTs. When tested against the gram-negative bacteria, the hydrogel/nanoclay composites showed a pronounced zone of inhibition suggesting that anti-microbial doped nanoclay enriched hydrogels can prevent the growth of bacteria. The release of gentamicin sulfate for a period of five days from the nanoclay-enriched hydrogels would supply anti-microbial agents in a sustained and controlled manner and assist in preventing microbial growth and biofilm formation on the titanium implant surface. A pilot study, using mouse osteoblasts, confirmed that the nanoclay enriched surfaces are also cell supportive as osteoblasts readily, proliferated and produced a type I collagen and proteoglycan matrix.

Chemical composition, antioxidant effects and antimicrobial ...

African Journals Online (AJOL)

Thymus vulgaris, Cinnamomum zeylanicum and Ocimum gratissimum are spices widely used as aroma enhancers and food preservatives. This work assessed the chemical composition, antioxidant and antimicrobial effect of their essential oils on some food pathogenic bacteria, namely, Staphylococcus aureus, Citrobacter ...

Antimicrobial action and anti-corrosion effect against sulfate reducing bacteria by lemongrass (Cymbopogon citratus) essential oil and its major component, the citral

Science.gov (United States)

2013-01-01

The anti-corrosion effect and the antimicrobial activity of lemongrass essential oil (LEO) against the planktonic and sessile growth of a sulfate reducing bacterium (SRB) were evaluated. Minimum inhibitory concentration (MIC) of LEO and its major component, the citral, was 0.17 mg ml-1. In addition, both LEO and citral showed an immediate killing effect against SRB in liquid medium, suggesting that citral is responsible for the antimicrobial activity of LEO against SRB. Transmission electron microscopy revealed that the MIC of LEO caused discernible cell membrane alterations and formed electron-dense inclusions. Neither biofilm formation nor corrosion was observed on carbon steel coupons after LEO treatment. LEO was effective for the control of the planktonic and sessile SRB growth and for the protection of carbon steel coupons against biocorrosion. The application of LEO as a potential biocide for SRB growth control in petroleum reservoirs and, consequently, for souring prevention, and/or as a coating protection against biocorrosion is of great interest for the petroleum industries. PMID:23938023

Influence of factors on release of antimicrobials from antimicrobial packaging materials.

Science.gov (United States)

Wu, Yu-Mei; Wang, Zhi-Wei; Hu, Chang-Ying; Nerín, Cristina

2018-05-03

Antimicrobial packaging materials (films or coatings) (APMs) have aroused great interest among the scientists or the experts specialized in material science, food science, packaging engineering, biology and chemistry. APMs have been used to package the food, such as dairy products, poultry, meat (e.g., beef), salmon muscle, pastry dough, fresh pasta, bakery products, fruits, vegetables and beverages. Some materials have been already commercialized. The ability of APMs to extend the shelf-life of the food depends on the release rate of the antimicrobials (AMs) from the materials to the food. The optimum rate is defined as target release rate (TRR). To achieve TRR, the influencing factors of the release rate should be considered. Herein we reviewed for the first time these factors and their influence on the release. These factors mainly include the AMs, food (or food simulant), packaging materials, the interactions among them, the temperature and environmental relative humidity (RH).

Studies on the antimicrobial effect of corn steep liquor on some ...

African Journals Online (AJOL)

ROFIAT

2014-01-08

Jan 8, 2014 ... The antimicrobial effect of Corn Steep Liquor (CSL) was investigated over a five day period. The pH and titrable acidity of the liquor were determined, while the antimicrobial effect on some diarrhoea causing organisms such as Escherichia coli, Salmonella enteriditis, Staphylococcus aureus and Vibrio.

Edible films and coatings in seafood preservation: A review.

Science.gov (United States)

Dehghani, Samira; Hosseini, Seyed Vali; Regenstein, Joe M

2018-02-01

Seafood is highly perishable and has a short shelf-life. During storage many reactions occur leading to changes in quality such as endogenous chemical and enzymatic reactions. The safety and shelf-life are related to the presence of food spoilage and pathogenic microorganisms. Despite improved manufacturing facilities and implementation of effective process control procedures such as the Hazard Analysis Critical Control Point system by seafood companies, the number of seafood-related foodborne illnesses has increased. Edible coatings can improve the quality of fresh and frozen products by retarding microbial growth, reducing lipid oxidation and moisture loss, and functioning as a carrier of food additives such as antimicrobial and antioxidant agents. Biodegradable edible coatings have various advantages over synthetic coatings such as being edible and generally being more environmentally friendly. This paper reviews the application of various types of natural bio-polymer and different active ingredients incorporated into the films and their effects on seafood quality attributes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-corrosive and anti-microbial properties of nanocrystalline Ni-Ag coatings

Energy Technology Data Exchange (ETDEWEB)

Raghupathy, Y.; Natarajan, K.A.; Srivastava, Chandan, E-mail: csrivastava@materials.iisc.ernet.in

2016-04-15

Graphical abstract: - Highlights: • Electrodeposition yielded phase-segregated, nanocrystalline Ni-Ag coatings. • Ni-Ag alloys exhibited smaller Ni crystals compared to pure Ni. • Ultra fine Ni grains of size 12–14 nm favoured Ni-Ag solid solution. • Nanocrystalline Ag resisted bio-fouling by Sulphate Reducing bacteria. • Ni-Ag outperformed pure Ni in corrosion and bio-corrosion tests. - Abstract: Anti-corrosive and anti-bacterial properties of electrodeposited nanocrystalline Ni-Ag coatings are illustrated. Pure Ni, Ni-7 at.% Ag, & Ni-14 at.% Ag coatings were electrodeposited on Cu substrate. Coating consisted of Ni-rich and Ag-rich solid solution phases. With increase in the Ag content, the corrosion resistance of the Ni-Ag coating initially increased and then decreased. The initial increase was due to the Ni-Ag solid solution. The subsequent decrease was due to the increased galvanic coupling between the Ag-rich and Ni-rich phases. For all Ag contents, the corrosion resistance of the Ni-Ag coating was higher than the pure Ni coating. Exposure to Sulphate Reducing Bacteria (SRB) revealed that the extent of bio-fouling decreased with increase in the Ag content. After 2 month exposure to SRB, the Ni-Ag coatings demonstrated less loss in corrosion resistance (58% for Ni-7 at.% Ag and 20% for Ni-14 at.% Ag) when compared pure Ni coating (115%).

Antimicrobial resistance challenged with metal-based antimicrobial macromolecules.

Science.gov (United States)

Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola

2017-02-01

Antimicrobial resistance threatens the achievements of science and medicine, as it deactivates conventional antimicrobial therapeutics. Scientists respond to the threat by developing new antimicrobial platforms to prevent and treat infections from these resistant strains. Metal-based antimicrobial macromolecules are emerging as an alternative to conventional platforms because they combine multiple mechanisms of action into one platform due to the distinctive properties of metals. For example, metals interact with intracellular proteins and enzymes, and catalyse various intracellular processes. The macromolecular architecture offers a means to enhance antimicrobial activity since several antimicrobial moieties can be conjugated to the scaffold. Further, these macromolecules can be fabricated into antimicrobial materials for contact-killing medical implants, fabrics, and devices. As volatilization or leaching out of the antimicrobial moieties from the macromolecular scaffold is reduced, these medical implants, fabrics, and devices can retain their antimicrobial activity over an extended period. Recent advances demonstrate the potential of metal-based antimicrobial macromolecules as effective platforms that prevent and treat infections from resistant strains. In this review these advances are thoroughly discussed within the context of examples of metal-based antimicrobial macromolecules, their mechanisms of action and biocompatibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS IN LAB COATS OF NURSING STUDENTS

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Jean Phellipe Marques do Nascimento

2016-05-01

Full Text Available The aim of the present study was to investigate the presence of Staphylococcus sp. in lab coats nursing students, in addition to determining the antimicrobial sensitivity profile of the isolated bacteria. The bacterial samples were collected, identified and characterized phenotypically, with subsequent determination of antimicrobial sensitivity profile by disk diffusion technique, according to recommendation of the Clinical and Laboratory Standards Institute. 57 colonies were isolated, where 51% were identified as Staphylococcus coagulase negative, 47% as Staphylococcus aureus and 2% belonging to a genus not identified. Among the samples identified as S. aureus, 15% were resistant to Oxacillin and 55% showed resistance to more than one antimicrobial.The results obtained in this work strengthen the role of the lab coat as a source of contamination of pathogenic microorganisms, as well as its possible role in the spread of these pathogens within and outside the hospital environment

Activity of a melimine derived peptide Mel4 against Stenotrophomonas, Delftia, Elizabethkingia, Burkholderia and biocompatibility as a contact lens coating

DEFF Research Database (Denmark)

Dutta, Debarun; Zhao, Timothy; Cheah, Kai Bing

2017-01-01

Purpose To determine the antimicrobial activity of the melimine derived peptide Mel4 against Delftia, Stenotrophomonas, Elizabethkingia, Burkholderia and to investigate biocompatibility of Mel4 as an antimicrobial coating on contact lenses in animals and humans. Methods In vitro antimicrobial...... activity of Mel4 was determined against the four Gram negative bacteria by investigating growth curves for 24 h followed by viable counts to determine the minimum inhibitory concentration (MIC). Contact lenses were coated by covalently binding Mel4, characterized by amino acid analysis, and were...... was active against all the bacteria tested (MIC50 ranged from 31–1000 μg ml−1) and produced an antimicrobial surface on contact lenses. Mel4-coating resulted hydrophilic surface without any significant change in contact lens parameters, and showed no signs of cytotoxicity or ocular irritation during rabbit...

Antimicrobial Air Filters Using Natural Euscaphis japonica Nanoparticles.

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Gi Byoung Hwang

Full Text Available Controlling bioaerosols has become more important with increasing participation in indoor activities. Treatments using natural-product nanomaterials are a promising technique because of their relatively low toxicity compared to inorganic nanomaterials such as silver nanoparticles or carbon nanotubes. In this study, antimicrobial filters were fabricated from natural Euscaphis japonica nanoparticles, which were produced by nebulizing E. japonica extract. The coated filters were assessed in terms of pressure drop, antimicrobial activity, filtration efficiency, major chemical components, and cytotoxicity. Pressure drop and antimicrobial activity increased as a function of nanoparticle deposition time (590, 855, and 1150 µg/cm2(filter at 3-, 6-, and 9-min depositions, respectively. In filter tests, the antimicrobial efficacy was greater against Staphylococcus epidermidis than Micrococcus luteus; ~61, ~73, and ~82% of M. luteus cells were inactivated on filters that had been coated for 3, 6, and 9 min, respectively, while the corresponding values were ~78, ~88, and ~94% with S. epidermidis. Although statistically significant differences in filtration performance were not observed between samples as a function of deposition time, the average filtration efficacy was slightly higher for S. epidermidis aerosols (~97% than for M. luteus aerosols (~95%. High-performance liquid chromatography (HPLC and electrospray ionization-tandem mass spectrometry (ESI/MS analyses confirmed that the major chemical compounds in the E. japonica extract were 1(ß-O-galloyl pedunculagin, quercetin-3-O-glucuronide, and kaempferol-3-O-glucoside. In vitro cytotoxicity and disk diffusion tests showed that E. japonica nanoparticles were less toxic and exhibited stronger antimicrobial activity toward some bacterial strains than a reference soluble nickel compound, which is classified as a human carcinogen. This study provides valuable information for the development of a

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

Science.gov (United States)

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

2014-05-01

d-Limonene has been considered to be a safer alternative compared to synthetic antimicrobial food additives. However, its hydrophobic and oxidative nature has limited its application in foods. The purpose of this research was to study effects of nisin on the antimicrobial activity of d-limonene and its nanoemulsion and develop a novel antimicrobial delivery system by combining the positive effect of these two antibacterial agents at the same time. By the checkerboard method, both the synergistic and additive effects of d-limonene and nisin were found against four selected food-related microorganisms. Then, d-limonene nanoemulsion with or without nisin was prepared by catastrophic phase inversion method, which has shown good droplet size and stability. The positive effects and outstanding antimicrobial activity of d-limonene nanoemulsion with nisin were confirmed by MICs comparison, scanning electron microscopy and determination of cell constituents released. Overall, the research described in the current article would be helpful in developing a more effective antimicrobial system for the production and preservation of foods. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Skin compatibility and antimicrobial studies on biofunctionalized polypropylene fabric

Energy Technology Data Exchange (ETDEWEB)

Anjum, Sadiya [Bioengineering Laboratory, Department of Textile Technology, Indian Institute of Technology, New Delhi 110016 (India); Gupta, Amlan; Sharma, Deepika [Department of Pathology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102 (India); Dalal, Prashansa [Bioengineering Laboratory, Department of Textile Technology, Indian Institute of Technology, New Delhi 110016 (India); Gupta, Bhuvanesh, E-mail: bgupta@textile.iitd.ernet.in [Bioengineering Laboratory, Department of Textile Technology, Indian Institute of Technology, New Delhi 110016 (India)

2016-12-01

The aim of this study was the development of antimicrobial fabric which can be used as skin contacting material. The nanosilver loaded bioactive nanogels of polyacrylamide were prepared by gamma irradiation process and the particle size was observed to be in the range of 10–50 nm. In this study, we used polyethylene glycol as carrier for the combination of functional nanogel and essential oils together. Plasma functionalized polypropylene fabric was used as the base material for the bio-immobilization. Bioactive emulsion was coated on the fabric which exhibited excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. Skin irritation studies were carried out over a period of 3 d on Swiss albino mice. Histopathology studies of the fabric did not show adverse inflammatory response in contact with the skin. The biofunctionalized fabric offers appear to be promising material for skin contacting applications. - Highlights: • Antimicrobial processing of PP fabric for skin contacting material • Polyethylene glycol is used for the carrier of bioactive nanogels. • Synergistic effect of functional nanosilver and essential oil has been investigated. • Skin compatibility and histopathological studies of material have been observed.

The effect of microstructure at interface between coating and substrate on damping capacity of coating systems

International Nuclear Information System (INIS)

Wang, Xueqin; Pei, Yanling; Ma, Yue

2013-01-01

Samples with various interface microstructures between the coating and the substrate were designed and fabricated in this paper. Dynamic mechanical thermal analyzer (DMTA) was utilized to investigate the dynamic mechanical properties of the samples and scanning electron microscopy (SEM) was used to observe the interface microstructure between the substrate and coating. The effect of the interface microstructure on damping was studied, and results indicated that the larger the coating/substrate interface thickness was and the more interface defects were, the higher interface system damping was. When the micro-hardness ratio of substrate to coating was increased, the damping of coating system was enhanced. The effect of the APS and EB-PVD coating on damping capacity was investigated. There was a dramatic increase in the damping value of the APS coating when the strain was higher than 20 ppm, while the damping amplitude effect of the EB-PVD coating was not so obvious, which could mainly be caused by the different energy dissipation mechanisms of the two coatings.

Nano ZnO/amine composites antimicrobial additives to acrylic paints

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H.B. Kamal

2015-12-01

Full Text Available Nano ZnO has been widely used as an antimicrobial agent not only for food packaging purposes but also in many coating processes. The present work is meant to enhance such functions through the preparation of sustainable and safe conduct of nano ZnO composites with amine derivatives that are characterized by their antimicrobial and anti-fouling functional activities. The results obtained revealed a more comprehensive approach to the antimicrobial function based on the reported active oxide species role. The oxide/amine composites and the acrylic emulsion paint were characterized chemically and structurally through FT-IR, TGA and TEM supported by biological assessment of each ZnO/amine composite action. Results of the study concluded that equilibrium between the nano ZnO particles size, their dispersion form, and amine ability to stabilize the actively produced oxygen species responsible for the antimicrobial function, should all be accounted for when persistence of antimicrobial agent efficiency is regarded.

Analysis of different coating thickness on new type of planar interdigital sensors for endotoxin detection

KAUST Repository

Syaifudin, A. R Mohd

2013-05-01

New types of planar interdigital sensors have been fabricated on Silicon/Silicon Dioxide (Si/SiO2) wafers. The sensors were coated with pre-cursor silica functionalized with APTES (3-aminopropyltrietoxysilane) at different thicknesses. All sensors were then immobilized with Polymyxin, B (PmB). PmB is an antimicrobial peptide produced by the Gram-positive bacterium-Bacillus, has been immobilized on the coated sensors because of its specific binding properties to endotoxin. Studies were conducted to analyze the effect of different thicknesses of coatings on the sensitivity and selectivity of the sensors. It was observed sensors coated with 3 layers of coating has better sensitivity and selectivity to the target molecules (endotoxin) compared to sensors with 5 layers of coating. The repeatability and stability of the coated sensors were tested by multiple standard endotoxin measurement and it was observed that the sensors give a good reproducibility and stability up to six continuous measurements before the coating degrades. © 2013 IEEE.

The surface properties of biopolymer-coated fruit: A review

Directory of Open Access Journals (Sweden)

Diana Cristina Moncayo Martinez

2013-09-01

Full Text Available Environmental conservation concerns have led to research and development regarding biodegradable materials from biopolymers, leading to new formulations for edible films and coatings for preserving the quality of fresh fruit and vegetables. Determining fruit skin surface properties for a given coating solution has led to predicting coating efficiency. Wetting was studied by considering spreading, adhesion and cohesion and measuring the contact angle, thus optimising the coating formulation in terms of biopolymer, plasticiser, surfactant, antimicrobial and antioxidant concentration. This work reviews the equations for determining fruit surface properties by using polar and dispersive interaction calculations and by determining the contact angle.

Effect of thyme oil-alginate-based coating on quality and microbial safety of fresh-cut apples.

Science.gov (United States)

Sarengaowa; Hu, Wenzhong; Jiang, Aili; Xiu, Zhilong; Feng, Ke

2018-04-01

Food preservation is critical for keeping fresh-cut products fresh, nutritious, safe, attractive and available for consumers. To improve the safety and quality of fresh-cut fruits, 15 essential oils (EOs) were screened to test the antimicrobial activity against Listeria monocytogenes (LM), Salmonella typhimurium (ST), Staphylococcus aureus (SA) and Escherichia coli O157:H7 (EC O157:H7). The effect of alginate-based edible coating (EC) incorporating different concentrations thyme oil on fresh-cut 'Red Fuji' apples was investigated. Results showed that thyme oil, cinnamon oil and oregano oil were more effective in inhibiting the microbes than other EOs. The result showed that the combined usage of 0.5 µL mL -1 thyme oil incorporated with alginate-based EC could significantly inhibit the microbial growth, respiration, weight loss, firmness and browning of fresh-cut 'Red Fuji' apples. The edible coating and natural additives like thyme oil could be used to preserve the quality of fresh-cut fruits. It revealed that EC incorporated with 0.5 µL mL -1 thyme oil can be a safe preservative for fresh-cut apples. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Activity of a melimine derived peptide Mel4 against Stenotrophomonas, Delftia, Elizabethkingia, Burkholderia and biocompatibility as a contact lens coating.

Science.gov (United States)

Dutta, Debarun; Zhao, Timothy; Cheah, Kai Bing; Holmlund, Larke; Willcox, Mark D P

2017-06-01

To determine the antimicrobial activity of the melimine derived peptide Mel4 against Delftia, Stenotrophomonas, Elizabethkingia, Burkholderia and to investigate biocompatibility of Mel4 as an antimicrobial coating on contact lenses in animals and humans. In vitro antimicrobial activity of Mel4 was determined against the four Gram negative bacteria by investigating growth curves for 24h followed by viable counts to determine the minimum inhibitory concentration (MIC). Contact lenses were coated by covalently binding Mel4, characterized by amino acid analysis, and were investigated for changes in lens parameters. Safety of Mel-4 coated lenses were determined in a rabbit model of daily contralateral wear. A prospective, randomised, double-masked, contralateral, 1week daily wear human clinical trial was used to evaluate subjective responses and ocular physiology. Mel4 was active against all the bacteria tested (MIC 50 ranged from 31-1000μgml -1 ) and produced an antimicrobial surface on contact lenses. Mel4-coating resulted hydrophilic surface without any significant change in contact lens parameters, and showed no signs of cytotoxicity or ocular irritation during rabbit wear. During human clinical trial, there were no differences between Mel4 coated and uncoated contact lenses in lens performance indicators and ocular signs such as corneal fluorescein staining. Mel4 and control uncoated lenses had no differences in ocular symptoms during lens wear. Mel4 has achieved antimicrobial activity against variety of Gram negative bacteria that are often resistant to the action of cationic peptides and have been implicated in contact lens related adverse events. Mel4-coated contact lenses were safe to wear. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

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

2005-10-03

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

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

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Afshin Shirkani

2014-04-01

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

Aqueous Zinc Compounds as Residual Antimicrobial Agents for Textiles.

Science.gov (United States)

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

2018-03-07

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

Antibacterial and Barrier Properties of Gelatin Coated by Electrospun Polycaprolactone Ultrathin Fibers Containing Black Pepper Oleoresin of Interest in Active Food Biopackaging Applications

Directory of Open Access Journals (Sweden)

Kelly Johana Figueroa-Lopez

2018-03-01

Full Text Available The present study evaluated the effect of using electrospun polycaprolactone (PCL as a barrier coating and black pepper oleoresin (OR as a natural extract on the morphology, thermal, mechanical, antimicrobial, oxygen, and water vapor barrier properties of solvent cast gelatin (GEL. The antimicrobial activity of the developed multilayer system obtained by the so-called electrospinning coating technique was also evaluated against Staphylococcus aureus strains for 10 days. The results showed that the multilayer system containing PCL and OR increased the thermal resistance, elongated the GEL film, and significantly diminished its permeance to water vapor. Active multilayer systems stored in hermetically closed bottles increased their antimicrobial activity after 10 days by inhibiting the growth of Staphylococcus aureus. This study demonstrates that addition of electrospun PCL ultrathin fibers and OR improved the properties of GEL films, which promoted its potential use in active food packaging applications.

Edible antimicrobial films based on microencapsulated lemongrass oil.

Science.gov (United States)

Bustos C, Rubén O; Alberti R, Francesca V; Matiacevich, Silvia B

2016-01-01

Edible films and coatings have been proposed as viable alternatives for the preservation of fresh food such as fruit, meat, fish and cheese. They can be designed to contain natural antioxidants, vitamins and antimicrobials in order to extend shelf life of the product keeping the natural sensorial properties. Essential oils have been targeted as potential active principles for edible films and coatings given their well-recognized antioxidant, antimicrobial and sensory properties. In the present work, lemongrass oil (LMO) microcapsules were prepared by the emulsification-separation method using sodium caseinate as wall material. Microcapsules had an average size of 22 μm and contained over 51 % oil in their nucleus. The release kinetics of the LMO components was studied for both, microcapsules and microcapsule containing films. Experimental data for the controlled release of LMO components showed good correlation with Peppas and Weibull models. The effect of the alginate matrix on the release parameters of the mathematical models could be detected by the modification of the b constant of the Weibull equation which changed from 0.167 for the microcapsules to 0.351 for the films. Films containing LMO at concentrations of 1250, 2500 and 5000 ppm were able to inhibit growth of Escherichia coli ATCC 25922 and Listeria monocytogenes ISP 65-08 in liquid cultures. A possible future application of these films for shelf life extension of fresh food is discussed.

Oral antimicrobials increase antimicrobial resistance in porcine E. coli--a systematic review.

Science.gov (United States)

Burow, E; Simoneit, C; Tenhagen, B-A; Käsbohrer, A

2014-03-01

Administration of antimicrobials to livestock increases the risk of antimicrobial resistance (AMR) in commensal bacteria. Antimicrobials in pig production are usually administered per pen via feed which implies treatment of sick alongside with healthy animals. The objective of this systematic literature review was to investigate the effect of orally administered antimicrobials on AMR in Escherichia coli of swine. Studies published in peer reviewed journals were retrieved from the international online databases ISI Web of Knowledge, PubMed, Scopus and the national electronic literature data base of Deutsches Institut für Medizinische Dokumentation und Information. The studies were assessed using the eligibility criteria English or German language, access to full paper version, defined treatment and control group (initial value or non-treatment) as well as administration and resistance testing of the same antimicrobial class. In the qualitative synthesis, only studies were included presenting the summary measures odds ratio or prevalence of resistance, the category of the applied antimicrobial and the dosage. An effect of the antimicrobial on AMR in E. coli was evaluated as an "increase", "no effect" or "decrease" if the odds or alternatively the prevalence ratio were >1.0, 1.0 or antimicrobial substance and dosage was missing in 4 and 5 of the 11 finally selected studies. The 36 identified trials were inhomogenous in usage and provision of information on sample size. Oral administration of antimicrobials increases the risk of AMR in E. coli from swine. There is however a lack of studies on the impact of dosage and longitudinal effects of treatment. The published studies have a number of issues concerning their scientific quality. More high quality research is needed to better address and quantifiy the effect of orally administered antimicrobials on AMR in swine. Copyright © 2014 Elsevier B.V. All rights reserved.

Antimicrobial activity of silica coated silicon nano-tubes (SCSNT) and silica coated silicon nano-particles (SCSNP) synthesized by gas phase condensation.

Science.gov (United States)

Tank, Chiti; Raman, Sujatha; Karan, Sujoy; Gosavi, Suresh; Lalla, Niranjan P; Sathe, Vasant; Berndt, Richard; Gade, W N; Bhoraskar, S V; Mathe, Vikas L

2013-06-01

Silica-coated, silicon nanotubes (SCSNTs) and silica-coated, silicon nanoparticles (SCSNPs) have been synthesized by catalyst-free single-step gas phase condensation using the arc plasma process. Transmission electron microscopy and scanning tunneling microscopy showed that SCSNTs exhibited a wall thickness of less than 1 nm, with an average diameter of 14 nm and a length of several 100 nm. Both nano-structures had a high specific surface area. The present study has demonstrated cheaper, resistance-free and effective antibacterial activity in silica-coated silicon nano-structures, each for two Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration (MIC) was estimated, using the optical densitometric technique, and by determining colony-forming units. The MIC was found to range in the order of micrograms, which is comparable to the reported MIC of metal oxides for these bacteria. SCSNTs were found to be more effective in limiting the growth of multidrug-resistant Staphylococcus aureus over SCSNPs at 10 μg/ml (IC 50 = 100 μg/ml).

Characterization of plasma-polymerized 4-vinyl pyridine with silver nanoparticies on poly(ethylene terephthalate) film for anti-microbial properties

DEFF Research Database (Denmark)

Jiang, J.; Winther-Jensen, Bjørn; Kjær, Erik Michael

2006-01-01

scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Different thicknesses Of poly(4-vinyl pyridine) coating under different plasma polymerization conditions were studied. Silver nanoparticles with diameter around 50nm deposit were precipitated...... on the poly(4-vinyl pyridine) coating by UV irradiation in Silver nitride water solution, in order to enhance the anti-microbial properties. Different kinds of modified PET films were tested for anti-microbial properties against yeast (Debaryomyces hansenii) by using microbiological analyser mu-4200...

Potential Adverse Effects of Broad-Spectrum Antimicrobial Exposure in the Intensive Care Unit.

Science.gov (United States)

Wiens, Jenna; Snyder, Graham M; Finlayson, Samuel; Mahoney, Monica V; Celi, Leo Anthony

2018-02-01

The potential adverse effects of empiric broad-spectrum antimicrobial use among patients with suspected but subsequently excluded infection have not been fully characterized. We sought novel methods to quantify the risk of adverse effects of broad-spectrum antimicrobial exposure among patients admitted to an intensive care unit (ICU). Among all adult patients admitted to ICUs at a single institution, we selected patients with negative blood cultures who also received ≥1 broad-spectrum antimicrobials. Broad-spectrum antimicrobials were categorized in ≥1 of 5 categories based on their spectrum of activity against potential pathogens. We performed, in serial, 5 cohort studies to measure the effect of each broad-spectrum category on patient outcomes. Exposed patients were defined as those receiving a specific category of broad-spectrum antimicrobial; nonexposed were all other patients in the cohort. The primary outcome was 30-day mortality. Secondary outcomes included length of hospital and ICU stay and nosocomial acquisition of antimicrobial-resistant bacteria (ARB) or Clostridium difficile within 30 days of admission. Among the study cohort of 1918 patients, 316 (16.5%) died within 30 days, 821 (42.8%) had either a length of hospital stay >7 days or an ICU length of stay >3 days, and 106 (5.5%) acquired either a nosocomial ARB or C. difficile . The short-term use of broad-spectrum antimicrobials in any of the defined broad-spectrum categories was not significantly associated with either primary or secondary outcomes. The prompt and brief empiric use of defined categories of broad-spectrum antimicrobials could not be associated with additional patient harm.

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

Science.gov (United States)

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

2017-09-01

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

Electrophoretic deposition of ZnO/alginate and ZnO-bioactive glass/alginate composite coatings for antimicrobial applications

Energy Technology Data Exchange (ETDEWEB)

Cordero-Arias, L.; Cabanas-Polo, S.; Goudouri, O.M. [Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, D-91058 Erlangen (Germany); Misra, S.K. [Materials Science and Engineering, Indian Institute of Technology Gandhinagar, Ahmedabad 382424 (India); Gilabert, J. [Institute of Ceramics Materials (ITC), University Jaume I, Avenida Vicent SosBaynat, 12006 Castellon (Spain); Valsami-Jones, E. [School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Sanchez, E. [Institute of Ceramics Materials (ITC), University Jaume I, Avenida Vicent SosBaynat, 12006 Castellon (Spain); Virtanen, S. [Institute for Surface Science and Corrosion (LKO, WW4), Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen (Germany); Boccaccini, A.R., E-mail: aldo.boccaccini@ww.uni-erlangen.de [Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, D-91058 Erlangen (Germany)

2015-10-01

Two organic/inorganic composite coatings based on alginate, as organic matrix, and zinc oxide nanoparticles (n-ZnO) with and without bioactive glass (BG), as inorganic components, intended for biomedical applications, were developed by electrophoretic deposition (EPD). Different n-ZnO (1–10 g/L) and BG (1–1.5 g/L) contents were studied for a fixed alginate concentration (2 g/L). The presence of n-ZnO was confirmed to impart antibacterial properties to the coatings against gram-negative bacteria Escherichia coli, while the BG induced the formation of hydroxyapatite on coating surfaces thereby imparting bioactivity, making the coating suitable for bone replacement applications. Coating composition was analyzed by thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) analyses. Scanning electron microscopy (SEM) was employed to study both the surface and the cross section morphology of the coatings. Polarization curves of the coated substrates made in cell culture media at 37 °C confirmed the corrosion protection function of the novel organic/inorganic composite coatings. - Highlights: • Organic–inorganic nanocomposite coatings fabricated by electrophoretic deposition • nZnO and bioactive glass containing alginate coatings exhibit antibacterial effect. • Bioactive character and anticorrosion function of coatings demonstrated.

Preparing high-adhesion silver coating on APTMS modified polyethylene with excellent anti-bacterial performance

Science.gov (United States)

Li, Wenfei; Chen, Yunxiang; Wu, Song; Zhang, Jian; Wang, Hao; Zeng, Dawen; Xie, Changsheng

2018-04-01

Silver coating as a broad-spectrum antimicrobial agent was considered to alleviate the inflammation caused by intrauterine device (IUD) in endometrium. In this work, to avoid the damage of silver coating and ensure its antibacterial properties, 3-aminopropyltrimethoxysilane (APTMS) was introduced to modify the polyethylene (PE) substrate for the purpose of improving the adhesion of the silver coating. From the 90° peel test, it could be found that the adhesive strength of silver coating on the APTMS modified PE substrate was nearly 23 times stronger than the silver coating on substrate without surface modification. The dramatically enhanced adhesive strength could be attributed to the formation of continuous chemical bonds between the silver coatings and substrates after surface modification, which had been confirmed by the XPS. Moreover, the standard antibacterial test revealed that the silver coated samples against Staphylococcus aureus (S. aureus) exhibit excellent antibacterial efficacy. Considering the largely enhanced adhesion and the effective antibacterial property, it is reasonable to believe that the silver coating could be considered as a potential candidate for the antibacterial agent in IUD.

Analyses of Biofilm on Implant Abutment Surfaces Coating with Diamond-Like Carbon and Biocompatibility.

Science.gov (United States)

Huacho, Patricia Milagros Maquera; Nogueira, Marianne N Marques; Basso, Fernanda G; Jafelicci Junior, Miguel; Francisconi, Renata S; Spolidorio, Denise M P

2017-01-01

The aim of this study was to evaluate the surface free energy (SFE), wetting and surface properties as well as antimicrobial, adhesion and biocompatibility properties of diamond-like carbon (DLC)-coated surfaces. In addition, the leakage of Escherichia coli through the abutment-dental implant interface was also calculated. SFE was calculated from contact angle values; R a was measured before and after DLC coating. Antimicrobial and adhesion properties against E. coli and cytotoxicity of DLC with human keratinocytes (HaCaT) were evaluated. Further, the ability of DLC-coated surfaces to prevent the migration of E. coli into the external hexagonal implant interface was also evaluated. A sterile technique was used for the semi-quantitative polymerase chain reaction (semi-quantitative PCR). The surfaces showed slight decreases in cell viability (p0.05). It was concluded that DLC was shown to be a biocompatible material with mild cytotoxicity that did not show changes in R a, SFE, bacterial adhesion or antimicrobial properties and did not inhibit the infiltration of E. coli into the abutment-dental implant interface.

Silver deposited carboxymethyl chitosan-grafted magnetic nanoparticles as dual action deliverable antimicrobial materials.

Science.gov (United States)

Vo, Duc-Thang; Sabrina, Sabrina; Lee, Cheng-Kang

2017-04-01

Carboxymethyl chitosan (CMCS) was known to have a much better antimicrobial activity than chitosan due to the increased cationic -NH 3 + groups resulted from the intra- and intermolecular interactions between the carboxyl and amino groups. CMCS was grafted onto the surface of silica coated magnetic nanoparticles (MNPs) to obtain magnetically retrievable and deliverable antimicrobial nanoparticles (MNPs@CMCS). The presence of carboxylate groups in CMCS not only enhanced antimicrobial activity but also enabled Ag ions chelating ability to induce the in situ formation of Ag nanoparticles (AgNPs). The deposition of AgNPs on the surface of MNPs@CMCS could significantly increase its antimicrobial activity against planktonic cells due to the dual action of CMCS and AgNPs. Due to its high magnetism, the as-prepared MNPs@CMCS-Ag could be efficiently delivered into an existing biofilm under the guidance of an applied magnetic field. Without direct contact, the Ag ions and/or radical oxygen species (ROS) released from the deposited Ag nanoparticles could effectively kill the bacteria embedded in the extracellular polymeric substances (EPS) matrix of biofilm. Copyright © 2016 Elsevier B.V. All rights reserved.

Viable adhered Staphylococcus aureus highly reduced on novel antimicrobial sutures using chlorhexidine and octenidine to avoid surgical site infection (SSI)

Science.gov (United States)

Schneider, Jochen; Harrasser, Norbert; Tübel, Jutta; Mühlhofer, Heinrich; Pförringer, Dominik; von Deimling, Constantin; Foehr, Peter; Kiefel, Barbara; Krämer, Christina; Stemberger, Axel; Schieker, Matthias

2018-01-01

Background Surgical sutures can promote migration of bacteria and thus start infections. Antiseptic coating of sutures may inhibit proliferation of adhered bacteria and avoid such complications. Objectives This study investigated the inhibition of viable adhering bacteria on novel antimicrobially coated surgical sutures using chlorhexidine or octenidine, a critical factor for proliferation at the onset of local infections. The medical need, a rapid eradication of bacteria in wounds, can be fulfilled by a high antimicrobial efficacy during the first days after wound closure. Methods As a pretesting on antibacterial efficacy against relevant bacterial pathogens a zone of inhibition assay was conducted with middle ranged concentrated suture coatings (22 μg/cm). For further investigation of adhering bacteria in detail the most clinically relevant Staphylococcus aureus (ATCC®49230™) was used. Absorbable braided sutures were coated with chlorhexidine-laurate, chlorhexidine-palmitate, octenidine-laurate, and octenidine-palmitate. Each coating type resulted in 11, 22, or 33 μg/cm drug content on sutures. Scanning electron microscopy (SEM) was performed once to inspect the coating quality and twice to investigate if bacteria have colonized on sutures. Adhesion experiments were assessed by exposing coated sutures to S. aureus suspensions for 3 h at 37°C. Subsequently, sutures were sonicated and the number of viable bacteria released from the suture surface was determined. Furthermore, the number of viable planktonic bacteria was measured in suspensions containing antimicrobial sutures. Commercially available sutures without drugs (Vicryl®, PGA Resorba®, and Gunze PGA), as well as triclosan-containing Vicryl® Plus were used as control groups. Results Zone of inhibition assay documented a multispecies efficacy of novel coated sutures against tested bacterial strains, comparable to most relevant S. aureus over 48 hours. SEM pictures demonstrated uniform layers on

The potential of photo-deposited silver coatings on Foley catheters to prevent urinary tract infections

International Nuclear Information System (INIS)

Cooper, Ian Richard; Pollini, Mauro; Paladini, Federica

2016-01-01

Catheter-associated urinary tract infection (CAUTI) represents one of the most common causes of morbidity and mortality. The resistance demonstrated by many microorganisms to conventional antibiotic therapies and the increasing health-care costs have recently encouraged the definition of alternative preventive strategies, which can have a positive effect in the management of infections. Antimicrobial urinary catheters have been developed through the photo-chemical deposition of silver coatings on the external and luminal surfaces. The substrates are exposed to ultraviolet radiation after impregnation into a silver-based solution, thus inducing the in situ synthesis of silver particles. The effect of the surface treatment on the material was investigated through scanning electron microscopy (SEM) and silver ion release measurements. The ability of microorganisms commonly associated with urinary tract infections was investigated in terms of bacterial viability, proliferation and biofilm development, using Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis as target organisms. The silver coatings demonstrated good distribution of silver particles to the substrate, and proved an effective antibacterial capability in simulated biological conditions. The low values of silver ion release demonstrated the optimum adhesion of the coating. The results indicated a good potential of silver-based antimicrobial materials for prevention of catheter-associated urinary tract infection. - Highlights: • Silver nanocoatings were deposited on urinary catheters. • Both luminal and outer surface were successfully treated. • The treated devices demonstrated were effective against different microorganisms. • The antibacterial potential of the devices was assessed.

The potential of photo-deposited silver coatings on Foley catheters to prevent urinary tract infections

Energy Technology Data Exchange (ETDEWEB)

Cooper, Ian Richard [School of Pharmacy & Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Pollini, Mauro, E-mail: mauro.pollini@unisalento.it [Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce (Italy); Silvertech Ltd, Via Monteroni, 73100 Lecce (Italy); Paladini, Federica [Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce (Italy)

2016-12-01

Catheter-associated urinary tract infection (CAUTI) represents one of the most common causes of morbidity and mortality. The resistance demonstrated by many microorganisms to conventional antibiotic therapies and the increasing health-care costs have recently encouraged the definition of alternative preventive strategies, which can have a positive effect in the management of infections. Antimicrobial urinary catheters have been developed through the photo-chemical deposition of silver coatings on the external and luminal surfaces. The substrates are exposed to ultraviolet radiation after impregnation into a silver-based solution, thus inducing the in situ synthesis of silver particles. The effect of the surface treatment on the material was investigated through scanning electron microscopy (SEM) and silver ion release measurements. The ability of microorganisms commonly associated with urinary tract infections was investigated in terms of bacterial viability, proliferation and biofilm development, using Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis as target organisms. The silver coatings demonstrated good distribution of silver particles to the substrate, and proved an effective antibacterial capability in simulated biological conditions. The low values of silver ion release demonstrated the optimum adhesion of the coating. The results indicated a good potential of silver-based antimicrobial materials for prevention of catheter-associated urinary tract infection. - Highlights: • Silver nanocoatings were deposited on urinary catheters. • Both luminal and outer surface were successfully treated. • The treated devices demonstrated were effective against different microorganisms. • The antibacterial potential of the devices was assessed.

[Isolation and antimicrobial activities of actinomycetes from vermicompost].

Science.gov (United States)

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

2015-02-01

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

Pediatric Obesity: Pharmacokinetic Alterations and Effects on Antimicrobial Dosing.

Science.gov (United States)

Natale, Stephanie; Bradley, John; Nguyen, William Huy; Tran, Tri; Ny, Pamela; La, Kirsten; Vivian, Eva; Le, Jennifer

2017-03-01

Limited data exist for appropriate drug dosing in obese children. This comprehensive review summarizes pharmacokinetic (PK) alterations that occur with age and obesity, and these effects on antimicrobial dosing. A thorough comparison of different measures of body weight and specific antimicrobial agents including cefazolin, cefepime, ceftazidime, daptomycin, doripenem, gentamicin, linezolid, meropenem, piperacillin-tazobactam, tobramycin, vancomycin, and voriconazole is presented. PubMed (1966-July 2015) and Cochrane Library searches were performed using these key terms: children, pharmacokinetic, obesity, overweight, body mass index, ideal body weight, lean body weight, body composition, and specific antimicrobial drugs. PK studies in obese children and, if necessary, data from adult studies were summarized. Knowledge of PK alterations stemming from physiologic changes that occur with age from the neonate to adolescent, as well as those that result from increased body fat, become an essential first step toward optimizing drug dosing in obese children. Excessive amounts of adipose tissue contribute significantly to body size, total body water content, and organ size and function that may modify drug distribution and clearance. PK studies that evaluated antimicrobial dosing primarily used total (or actual) body weight (TBW) for loading doses and TBW or adjusted body weight for maintenance doses, depending on the drugs' properties and dosing units. PK studies in obese children are imperative to elucidate drug distribution, clearance, and, consequently, the dose required for effective therapy in these children. Future studies should evaluate the effects of both age and obesity on drug dosing because the incidence of obesity is increasing in pediatric patients. © 2017 Pharmacotherapy Publications, Inc.

The Influence of Accelerated UV-A and Q-SUN Irradiation on the Antibacterial Properties of Hydrophobic Coatings Containing Eucomis comosa Extract

Directory of Open Access Journals (Sweden)

Małgorzata Mizielińska

2018-04-01

Full Text Available The purpose of this research was to examine the antimicrobial properties against Gram-positive bacteria, as well as the water vapour characteristic of polylactic acid (PLA films covered with a methyl–hydroxypropyl–cellulose (MHPC/cocoa butter carrier containing Eucomis comosa extract as an active substance. The second purpose of the study was to evaluate the influence of accelerated UV-A and Q-SUN irradiation (UV-aging on the antimicrobial properties and the barrier characteristic of the coatings. The results of the study revealed that MHPC/cocoa butter coatings had no influence on the growth of Staphylococcus aureus, Bacillus cereus, and Bacillus atrophaeus. MHPC/cocoa butter coatings containing E. comosa extract reduced the number of bacterial strains. MHPC/cocoa butter coatings also decreased the water vapour permeability of PLA. It was shown that accelerated UV-A and Q-SUN irradiations altered the chemical composition of the coatings containing cocoa butter. Despite the alteration of the chemical composition of the layers, the accelerated Q-SUN and UV-A irradiation had no influence on the antimicrobial properties of E. comosa extract coatings against S. aureus and B. cereus. It was found that only Q-SUN irradiation decreased the coating activity with an extract against B. atrophaeus, though this was to a small degree.

Nisin and its Antimicrobial Effect in Foods

Directory of Open Access Journals (Sweden)

Hamparsun Hampikyan

2007-04-01

Full Text Available Nisin is a bacteriocin which is produced by Lactococcus lactis and takes its place in I. class bacteriocins which are known as lantibiotics. Nisin has antimicrobial and bactericidal activity against a broad spectrum of gram positive bacteria and spores of Clostridium spp. and Bacillus spp. According to toxicity studies nisin is considered not toxic to humans. Its first established used was as a preservative in processed cheese products and since than numerous other applications in various foods such as meat and meat products, poultry products, sea products and beverages such as beer, wine have been used safely. In this review, the characteristics of nisin, its usage in food and its antimicrobial effect are considered. [TAF Prev Med Bull 2007; 6(2.000: 142-147

Effect of Dipping and Vacuum Impregnation Coating Techniques with Alginate Based Coating on Physical Quality Parameters of Cantaloupe Melon.

Science.gov (United States)

Senturk Parreidt, Tugce; Schmid, Markus; Müller, Kajetan

2018-04-01

Edible coating based on sodium alginate solution was applied to fresh-cut cantaloupe melon by dipping and vacuum impregnation coating methods. One aim of this work is to produce more technical information concerning these conventional and novel coating processes. For this purpose, the effect of various coating parameters (dipping time, draining time, time length of the vacuum period, vacuum pressure, atmospheric restoration time) with several levels on physical quality parameters (percentage of weight gain, color, and texture) of noncoated and coated samples were determined in order to define adequate coating process parameters to achieve a successful coating application. Additionally, the effects of dipping and vacuum impregnation processes were compared. Both processes improved the firmness of the melon pieces. However, vacuum impregnation application had higher firmness and weight gain results, and had significant effect (P coating technique and the parameters used significantly affect the physical quality characteristics of coated food products. The work presented produced more technical information concerning dipping and vacuum impregnation coating techniques, along with evaluating the effects of various coating parameters with several levels. The results revealed that vacuum impregnation technique is a successful coating method; however the effects should be carefully assessed for each product. © 2018 Institute of Food Technologists®.

Cholesterol suppresses antimicrobial effect of statins

Directory of Open Access Journals (Sweden)

Mohammad Reza Haeri

2015-12-01

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

241 Comparative Effectiveness of Certain Antimicrobial Agents in ...

African Journals Online (AJOL)

Nekky Umera

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

Mathematical modeling of photoinitiated coating degradation: Effects of coating glass transition temperature and light stabilizers

DEFF Research Database (Denmark)

Kiil, Søren; G.de With, R.A.T.M.Van Benthem

2013-01-01

A mathematical model, describing coating degradation mechanisms of thermoset coatings exposed to ultraviolet radiation and humidity at constant temperature, was extended to simulate the behavior of a coating with a low glass transition temperature. The effects of adding light stabilizers (a UV...

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

Directory of Open Access Journals (Sweden)

L Mion

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

Plum coatings of lemongrass oil-incorporating carnauba wax-based nanoemulsion.

Science.gov (United States)

Kim, In-Hah; Lee, Hanna; Kim, Jung Eun; Song, Kyung Bin; Lee, Youn Suk; Chung, Dae Sung; Min, Sea C

2013-10-01

Nanoemulsions containing lemongrass oil (LO) were developed for coating plums and the effects of the nanoemulsion coatings on the microbial safety and physicochemical storage qualities of plums during storage at 4 and 25 °C were investigated. The emulsions used for coating were produced by mixing a carnauba wax-based solution (18%, w/w) with LO at various concentrations (0.5% to 4.0%, w/w) using dynamic high pressure processing at 172 MPa. The coatings were evaluated for their ability to inhibit the growth of Salmonella Typhimurium and Escherichia coli O157:H7 and their ability to preserve various physicochemical qualities of plums. Uniform and continuous coatings on plums, formed with stable emulsions, initially inhibited S. Typhimurium and E. coli O157:H7 by 0.2 to 2.8 and 0.8 to 2.7 log CFU/g, respectively, depending on the concentration of LO and the sequence of coating. The coatings did not significantly alter the flavor, fracturability, or glossiness of the plums. The antimicrobial effects of the coatings against S. Typhimurium and E. coli O157:H7 were demonstrated during storage at 4 and 25 °C. The coatings reduced weight loss and ethylene production by approximately 2 to 3 and 1.4 to 4.0 fold, respectively, and also retarded the changes in lightness and the concentration of phenolic compounds in plums during storage. The firmness of coated plums was generally higher than uncoated plums when stored at 4 °C and plum respiration rates were reduced during storage. Coatings containing nanoemulsions of LO have the potential to inhibit Salmonella and E. coli O157:H7 contamination of plums and may extend plum shelf life. Journal of Food Science © 2013 Institute of Food Technologists® No claim to original US government works.

Advances in edible coatings for fresh fruits and vegetables: a review.

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Dhall, R K

2013-01-01

Edible coatings are an environmentally friendly technology that is applied on many products to control moisture transfer, gas exchange or oxidation processes. Edible coatings can provide an additional protective coating to produce and can also give the same effect as modified atmosphere storage in modifying internal gas composition. One major advantage of using edible films and coatings is that several active ingredients can be incorporated into the polymer matrix and consumed with the food, thus enhancing safety or even nutritional and sensory attributes. But, in some cases, edible coatings were not successful. The success of edible coatings for fresh products totally depends on the control of internal gas composition. Quality criteria for fruits and vegetables coated with edible films must be determined carefully and the quality parameters must be monitored throughout the storage period. Color change, firmness loss, ethanol fermentation, decay ratio and weight loss of edible film coated fruits need to be monitored. This review discusses the use of different edible coatings (polysaccharides, proteins, lipids and composite) as carriers of functional ingredients on fresh fruits and vegetables to maximize their quality and shelf life. This also includes the recent advances in the incorporation of antimicrobials, texture enhancers and nutraceuticals to improve quality and functionality of fresh-cut fruits. Sensory implications, regulatory status and future trends are also reviewed.

Development of bioactive coatings based on γ-irradiated proteins to preserve strawberries

International Nuclear Information System (INIS)

Vu, K.D.; Hollingsworth, R.G.; Salmieri, S.; Takala, P.N.; Lacroix, M.

2012-01-01

Gamma irradiation was applied for creating cross-linked proteins to enhance the physicochemical properties of edible films made of calcium caseinate, whey protein isolate and glycerol. The characteristics of γ irradiated cross-linked proteins were analyzed by Fourier Transform Infrared spectroscopy. A second derivative spectra exhibited changes in band intensities that were correlated to an increase of β-sheet structure and a decrease of α-helix and unordered fractions of γ irradiated-cross-linked proteins as compared to the control without irradiation. Furthermore, on addition of methylcellulose to the irradiated protein matrix it was found that it has potential in enhancing the puncture strength and has no detrimental effect on water vapor permeability of protein based films. Finally, these film formulations were used as bioactive edible coatings containing natural antimicrobial agents (limonene and peppermint) to preserve the shelf life of fresh strawberries during storage. The bioactive coatings containing peppermint was found to be more efficient as preserving coatings than the formulations containing limonene. Irradiated proteins/methylcellulose/peppermint formulation had only 40% of decay at day 8 while it was 65% for the control. - Highlights: ► Crosslinked proteins and antimicrobials agents was able to preserve strawberries. ► Crosslinked protein structure was more ordered. ► Films based on crosslinked proteins and methylcellulose enhanced puncture strength.

High performance polypyrrole coating for corrosion protection and biocidal applications

Science.gov (United States)

Nautiyal, Amit; Qiao, Mingyu; Cook, Jonathan Edwin; Zhang, Xinyu; Huang, Tung-Shi

2018-01-01

Polypyrrole (PPy) coating was electrochemically synthesized on carbon steel using sulfonic acids as dopants: p-toluene sulfonic acid (p-TSA), sulfuric acid (SA), (±) camphor sulfonic acid (CSA), sodium dodecyl sulfate (SDS), and sodium dodecylbenzene sulfonate (SDBS). The effect of acidic dopants (p-TSA, SA, CSA) on passivation of carbon steel was investigated by linear potentiodynamic and compared with morphology and corrosion protection performance of the coating produced. The types of the dopants used were significantly affecting the protection efficiency of the coating against chloride ion attack on the metal surface. The corrosion performance depends on size and alignment of dopant in the polymer backbone. Both p-TSA and SDBS have extra benzene ring that stack together to form a lamellar sheet like barrier to chloride ions thus making them appropriate dopants for PPy coating in suppressing the corrosion at significant level. Further, adhesion performance was enhanced by adding long chain carboxylic acid (decanoic acid) directly in the monomer solution. In addition, PPy coating doped with SDBS displayed excellent biocidal abilities against Staphylococcus aureus. The polypyrrole coatings on carbon steels with dual function of anti-corrosion and excellent biocidal properties shows great potential application in the industry for anti-corrosion/antimicrobial purposes.

Antimicrobial effect of calcium hydroxide as endo intracanal dressing on Streptococcus viridans

Directory of Open Access Journals (Sweden)

Nanik Zubaidah

2008-03-01

Full Text Available Calcium hydroxide had been used as the intra-canal dressing in endodontic treatment due to its high alkaline and antimicrobial capacity. It can also dissolve the necrotic tissue, prevent dental root resorbtion and regenerate a new hard tissue. The aim of this study was to determine the concentration of calcium hydroxide which had the highest antimicrobial effect on Streptococcus viridans. Samples were divided into 5 groups; each group consisted of 8 samples with different concentration of calcium hydroxide. Group I: 50%, group II: 55, Group III: 60%, Group IV: 65%, Group V: 70%. The antimicrobial testing was performed using diffusion method against Streptococcus viridans. The result of susceptibility test was showed by the inhibition zone diameter which measured with caliper (in millimeter. We analyzed the data using One-Way ANOVA test with significant difference 0.05 and subsequently LSD test. The study showed that calcium hydroxide with concentration 60% has the highest antimicrobial effect.

International cooperation to improve access to and sustain effectiveness of antimicrobials.

Science.gov (United States)

Årdal, Christine; Outterson, Kevin; Hoffman, Steven J; Ghafur, Abdul; Sharland, Mike; Ranganathan, Nisha; Smith, Richard; Zorzet, Anna; Cohn, Jennifer; Pittet, Didier; Daulaire, Nils; Morel, Chantal; Rizvi, Zain; Balasegaram, Manica; Dar, Osman A; Heymann, David L; Holmes, Alison H; Moore, Luke S P; Laxminarayan, Ramanan; Mendelson, Marc; Røttingen, John-Arne

2016-01-16

Securing access to effective antimicrobials is one of the greatest challenges today. Until now, efforts to address this issue have been isolated and uncoordinated, with little focus on sustainable and international solutions. Global collective action is necessary to improve access to life-saving antimicrobials, conserving them, and ensuring continued innovation. Access, conservation, and innovation are beneficial when achieved independently, but much more effective and sustainable if implemented in concert within and across countries. WHO alone will not be able to drive these actions. It will require a multisector response (including the health, agriculture, and veterinary sectors), global coordination, and financing mechanisms with sufficient mandates, authority, resources, and power. Fortunately, securing access to effective antimicrobials has finally gained a place on the global political agenda, and we call on policy makers to develop, endorse, and finance new global institutional arrangements that can ensure robust implementation and bold collective action. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chitosan-based coatings in the prevention of intravascular catheter-associated infections.

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Mendoza, Gracia; Regiel-Futyra, Anna; Tamayo, Alejandra; Monzon, Marta; Irusta, Silvia; de Gregorio, Miguel Angel; Kyzioł, Agnieszka; Arruebo, Manuel

2018-01-01

Central venous access devices play an important role in patients with prolonged intravenous administration requirements. In the last years, the coating of these devices with bactericidal compounds has emerged as a potential tool to prevent bacterial colonization. Our study describes the modification of 3D-printed reservoirs and silicone-based catheters, mimicking central venous access devices, through different approaches including their coating with the well known biocompatible and bactericidal polymer chitosan, with the anionic polysaccharide alginate; also, plasma treated surfaces were included in the study to promote polymer adhesion. The evaluation of the antimicrobial action of those surface modifications compared to that exerted by a model antibiotic (ciprofloxacin) adsorbed on the surface of the devices was carried out. Surface characterization was developed by different methodologies and the bactericidal effects of the different coatings were assayed in an in vitro model of Staphylococcus aureus infection. Our results showed a significant reduction in the reservoir roughness (≤73%) after coating though no changes were observed for coated catheters which was also confirmed by scanning electron microscopy, pointing to the importance of the surface device topography for the successful attachment of the coating and for the subsequent development of bactericidal effects. Furthermore, the single presence of chitosan on the reservoirs was enough to fully inhibit bacterial growth exerting the same efficiency as that showed by the model antibiotic. Importantly, chitosan coating showed low cytotoxicity against human keratinocytes, human lung adenocarcinoma epithelial cells, and murine colon carcinoma cells displaying viability percentages in the range of the control samples (>95%). Chitosan-based coatings are proposed as an effective and promising solution in the prevention of microbial infections associated to medical devices.

Fosfomycin Addition to Poly(D,L-Lactide Coating Does Not Affect Prophylaxis Efficacy in Rat Implant-Related Infection Model, But That of Gentamicin Does.

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Anil Gulcu

Full Text Available Gentamicin is the preferred antimicrobial agent used in implant coating for the prevention of implant-related infections (IRI. However, the present heavy local and systemic administration of gentamicin can lead to increased resistance, which has made its future use uncertain, together with related preventive technologies. Fosfomycin is an alternative antimicrobial agent that lacks the cross-resistance presented by other classes of antibiotics. We evaluated the efficacy of prophylaxis of 10% fosfomycin-containing poly(D,L-lactide (PDL coated K-wires in a rat IRI model and compared it with uncoated (Control 1, PDL-coated (Control 2, and 10% gentamicin-containing PDL-coated groups with a single layer of coating. Stainless steel K-wires were implanted and methicillin-resistant Staphylococcus aureus (ATCC 43300 suspensions (103 CFU/10 μl were injected into a cavity in the left tibiae. Thereafter, K-wires were removed and cultured in tryptic soy broth and then 5% sheep blood agar mediums. Sliced sections were removed from the tibiae, stained with hematoxylin-eosin, and semi-quantitatively evaluated with X-rays. The addition of fosfomycin into PDL did not affect the X-ray and histopathological evaluation scores; however, the addition of gentamicin lowered them. The addition of gentamicin showed a protective effect after the 28th day of X-ray evaluations. PDL-only coating provided no protection, while adding fosfomycin to PDL offered a 20% level protection and adding gentamicin offered 80%. Furthermore, there were 103 CFU level growths in the gentamicin-added group, while the other groups had 105. Thus, the addition of fosfomycin to PDL does not affect the efficacy of prophylaxis, but the addition of gentamicin does. We therefore do not advise the use of fosfomycin as a single antimicrobial agent in coating for IRI prophylaxis.

Antimicrobial Activity and Modulatory Effect of Essential Oil from the Leaf of Rhaphiodon echinus (Nees & Mart) Schauer on Some Antimicrobial Drugs.

Science.gov (United States)

Duarte, Antonia Eliene; de Menezes, Irwin Rose Alencar; Bezerra Morais Braga, Maria Flaviana; Leite, Nadghia Figueiredo; Barros, Luiz Marivando; Waczuk, Emily Pansera; Pessoa da Silva, Maria Arlene; Boligon, Aline; Teixeira Rocha, João Batista; Souza, Diogo Onofre; Kamdem, Jean Paul; Melo Coutinho, Henrique Douglas; Escobar Burger, Marilise

2016-06-08

Rhaphiodon echinus is a weed plant used in the Brazilian folk medicinal for the treatment of infectious diseases. In this study, the essential oil of R. echinus leaf was investigated for its antimicrobial properties. The chemical constituents of the essential oil were characterized by GC-MS. The antimicrobial properties were determined by studying by the microdilution method the effect of the oil alone, and in combination with antifungal or antibiotic drugs against the fungi Candida albicans, Candida krusei and Candida tropicalis and the microbes Escherichia coli, Staphylococcus aureus and Pseudomonas. In addition, the iron (II) chelation potential of the oil was determined. The results showed the presence of β-caryophyllene and bicyclogermacrene in major compounds, and revealed a low antifungal and antibacterial activity of the essential oil, but a strong modulatory effect on antimicrobial drugs when associated with the oil. The essential oil showed iron (II) chelation activity. The GC-MS characterization revealed the presence of monoterpenes and sesquiterpenes in the essential oil and metal chelation potential, which may be responsible in part for the modulatory effect of the oil. These findings suggest that essential oil of R. echinus is a natural product capable of enhancing the antibacterial and antifungal activity of antimicrobial drugs.

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

Science.gov (United States)

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

2018-05-09

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

Induced superhydrophobic and antimicrobial character of zinc metal modified ceramic wall tile surfaces

Science.gov (United States)

Özcan, Selçuk; Açıkbaş, Gökhan; Çalış Açıkbaş, Nurcan

2018-04-01

Hydrophobic surfaces are also known to have antimicrobial effect by restricting the adherence of microorganisms. However, ceramic products are produced by high temperature processes resulting in a hydrophilic surface. In this study, an industrial ceramic wall tile glaze composition was modified by the inclusion of metallic zinc powder in the glaze suspension applied on the pre-sintered wall tile bodies by spraying. The glazed tiles were gloss fired at industrially applicable peak temperatures ranging from 980 °C to 1100 °C. The fired tile surfaces were coated with a commercial fluoropolymer avoiding water absorption. The surfaces were characterized with SEM, EDS, XRD techniques, roughness, sessile water drop contact angle, surface energy measurements, and standard antimicrobial tests. The surface hydrophobicity and the antimicrobial activity results were compared with that of unmodified, uncoated gloss fired wall tiles. A superhydrophobic contact angle of 150° was achieved at 1000 °C peak temperature due to the formation of micro-structured nanocrystalline zinc oxide granules providing a specific surface topography. At higher peak temperatures the hydrophobicity was lost as the specific granular surface topography deteriorated with the conversion of zinc oxide granules to the ubiquitous willemite crystals embedded in the glassy matrix. The antimicrobial efficacy also correlated with the hydrophobic character.

Effects of materials containing antimicrobial compounds on food hygiene.

Science.gov (United States)

Møretrø, Trond; Langsrud, Solveig

2011-07-01

Surfaces with microorganisms may transfer unwanted microorganisms to food through cross-contamination during processing and preparation. A high hygienic status of surfaces that come in contact with food is important in order to reduce the risk of cross-contamination. During the last decade, products containing antimicrobial compounds, such as cutting boards, knives, countertops, kitchen utensils, refrigerators, and conveyor belts, have been introduced to the market, claiming hygienic effects. Such products are often referred to as "treated articles." Here we review various aspects related to treated articles intended for use during preparation and processing of food. Regulatory issues and methods to assess antibacterial effects are covered. Different concepts for treated articles as well as their antibacterial activity are reviewed. The effects of products with antimicrobials on food hygiene and safety are discussed. Copyright ©, International Association for Food Protection

Development of HA/Ag-NPs Composite Coating from Green Process for Hip Applications.

Science.gov (United States)

Lozoya-Rodríguez, Denisse A; de Lima, Renata; Fraceto, Leonardo F; Ledezma Pérez, Antonio; Bazaldua Domínguez, Mercedes; Gómez Batres, Roberto; Reyes Rojas, Armando; Orozco Carmona, Víctor

2017-08-08

In the present study, biological hydroxyapatite (HA) was obtained from bovine bones through a thermal process. A total of 0% and 1% of silver nanoparticles (Ag-NPs) synthesized from Opuntia ficus (nopal) were added to the biological hydroxyapatite coatings using an atmospheric plasma spray (APS) on a Ti6Al4V substrate. Following this, its antimicrobial efficiency was evaluated against the following bacterial strains: Escherichia coli , Staphylococcus aureus , and Pseudomonas aeruginosa . This was conducted according to the Japanese Industrial Standard (JIS) Z2801:2000 "Antimicrobial Product-Test for Antimicrobial Activity and Efficacy". Scanning electron microscopy (SEM) showed that the silver nanoparticles (Ag-NPs) were evenly distributed on the coating surface. Energy dispersive X-ray spectroscopy (EDX) shows that apatite deposition occurs on a daily basis, maintaining a Ca/P rate between 2.12 and 1.45. Biocompatibility properties were evaluated with osteoblast-like cells (MC3T3-E1) by single-cell gel electrophoresis assay and Tali image cytometry.

Production of Recombinant Antimicrobial Polymeric Protein Beta Casein-E 50-52 and Its Antimicrobial Synergistic Effects Assessment with Thymol

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Shohreh Fahimirad

2017-05-01

Full Text Available Accelerating emergence of antimicrobial resistance among food pathogens and consumers’ increasing demands for preservative-free foods are two contemporary challenging aspects within the food industry. Antimicrobial packaging and the use of natural preservatives are promising solutions. In the present study, we used beta-casein—one of the primary self-assembly proteins in milk with a high polymeric film production capability—as a fusion partner for the recombinant expression of E 50-52 antimicrobial peptide in Escherichia coli. The pET21a-BCN-E 50-52 construct was transformed to E. coli BL21 (DE3, and protein expression was induced under optimized conditions. Purified protein obtained from nickel affinity chromatography was refolded under optimized dialysis circumstances and concentrated to 1600 µg/mL fusion protein by ultrafiltration. Antimicrobial activities of recombinant BCN-E 50-52 performed against Escherichia coli, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, Aspergillus flavus, and Candida albicans. Subsequently, the synergistic effects of BCN-E 50-52 and thymol were assayed. Results of checkerboard tests showed strong synergistic activity between two compounds. Time–kill and growth kinetic studies indicated a sharp reduction of cell viability during the first period of exposure, and SEM (scanning electron microscope results validated the severe destructive effects of BCN E 50-52 and thymol in combination on bacterial cells.

Effect of novel bioactive edible coatings based on jujube gum and nettle oil-loaded nanoemulsions on the shelf-life of Beluga sturgeon fillets.

Science.gov (United States)

Gharibzahedi, Seyed Mohammad Taghi; Mohammadnabi, Sara

2017-02-01

Effect of jujube gum (JG; 4, 8 and 12% wt)-based nanoemulsions (NEs) containing nettle essential oil (NEO; 2, 3.5 and 5% wt) as new edible coatings was investigated to preserve Beluga sturgeon fillets (BSFs) during 15 day-refrigerated storage at 4°C. Physical (weight loss, cooking loss, color and texture), chemical (pH, FFA, PV, TBARS and TVB-N), microbiological (total and psychrotrophic bacterial counts), and sensorial characteristics of BSFs were kinetically analyzed. Preliminary studies showed that the NEs formulated with NEO lower than 5% at all JG concentrations were able to form stable coating solutions owing to the highest short-term stability (>90%) and entrapment efficiency (94.4-98.3%). Edible NE coating formulated with 12% JG and 3.5% NEO as a novel antimicrobial and antioxidant biomaterial exhibited the lowest weight and cooking losses, pH changes, textural and color deterioration, lipid oxidation and microbial growth in BSFs refrigerated over a period of 15days (P<0.05). Copyright © 2016 Elsevier B.V. All rights reserved.

Alternative Antimicrobial Approach: Nano-Antimicrobial Materials

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Nurit Beyth

2015-01-01

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

General principles of antimicrobial therapy.

Science.gov (United States)

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

2011-02-01

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

Effect of Coating and Packaging Materials on Photocatalytic and Antimicrobial Activities of Titanium Dioxide Nanoparticles

Science.gov (United States)

Food safety or foodborne pathogen contamination is a major concern in food industry. Titanium dioxide (TiO2) is a photocatalyst and can inactivate a wide spectrum of microorganisms under UV illumination. There is significant interest in the development of TiO2-coated or –incorporated food packaging ...

Antimicrobial effect of Malaysian vegetables against enteric bacteria

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Hassanain Al-Talib

2016-03-01

Conclusions: Garlic had excellent antimicrobial effects against enteric bacteria and was recommended to be given to patients with gastroenteritis. The other vegetables (pennywort, mint, parsley and celery showed no inhibitory effects on enteric bacteria but still can be used for its richness in vitamins and fibers. The performance of the well diffusion method was better than that of the disc diffusion method in detecting the antibacterial effects of green vegetables.

Effect of substrate preheating temperature and coating thickness on residual stress in plasma sprayed hydroxyapatite coating

International Nuclear Information System (INIS)

Tang, Dapei

2015-01-01

A thermal-mechanical coupling model was developed based on thermal-elastic- plastic theory according the special process of plasma spraying Hydroxyapatite (HA) coating upon Ti-6Al-4V substrate. On the one hand, the classical Fourier transient heat conduction equation was modified by introducing the effect item of deformation on temperature, on the other hand, the Johnson-Cook model, suitable for high temperature and high strain rate conditions, was used as constitutive equation after considering temperature softening effect, strain hardening effect and strain rate reinforcement effect. Based on the above coupling model, the residual stress field within the HA coating was simulated by using finite element method (FEM). Meanwhile, the substrate preheating temperature and coating thickness on the influence of residual stress components were calculated, respectively. The failure modes of coating were also preliminary analyzed. In addition, in order to verify the reliability of calculation, the material removal measurement technique was applied to determine the residual stress of HA coating near the interface. Some important conclusions are obtained. (paper)

Chitosan preparations for wounds and burns: antimicrobial and wound-healing effects

Science.gov (United States)

Dai, Tianhong; Tanaka, Masamitsu; Huang, Ying-Ying; Hamblin, Michael R

2011-01-01

Since its discovery approximately 200 years ago, chitosan, as a cationic natural polymer, has been widely used as a topical dressing in wound management owing to its hemostatic, stimulation of healing, antimicrobial, nontoxic, biocompatible and biodegradable properties. This article covers the antimicrobial and wound-healing effects of chitosan, as well as its derivatives and complexes, and its use as a vehicle to deliver biopharmaceuticals, antimicrobials and growth factors into tissue. Studies covering applications of chitosan in wounds and burns can be classified into in vitro, animal and clinical studies. Chitosan preparations are classified into native chitosan, chitosan formulations, complexes and derivatives with other substances. Chitosan can be used to prevent or treat wound and burn infections not only because of its intrinsic antimicrobial properties, but also by virtue of its ability to deliver extrinsic antimicrobial agents to wounds and burns. It can also be used as a slow-release drug-delivery vehicle for growth factors to improve wound healing. The large number of publications in this area suggests that chitosan will continue to be an important agent in the management of wounds and burns. PMID:21810057

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

Science.gov (United States)

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

2016-07-01

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

Antimicrobial effect of lactobacillus and bacillus derived ...

African Journals Online (AJOL)

This study focused on the screening, production, extraction of biosurfactants from Lactobacillus and Bacillus bacteria and their antimicrobial properties against causal microorganisms of food borne infections (food borne pathogens). The biosurfactants were investigated for potential antimicrobial activity using disk diffusion.

The Effect of CuO Nanoparticles on Antimicrobial Effects and Shear Bond Strength of Orthodontic Adhesives.

Science.gov (United States)

Toodehzaeim, Mohammad Hossein; Zandi, Hengameh; Meshkani, Hamidreza; Hosseinzadeh Firouzabadi, Azadeh

2018-03-01

Orthodontic appliances facilitate microbial plaque accumulation and increase the chance of white spot lesions. There is a need for new plaque control methods independent of patient's cooperation. The aim of this study was to determine the effects of incorporating copper oxide (CuO) nanoparticles on antimicrobial properties and bond strength of orthodontic adhesive. CuO nanoparticles were added to the composite transbond XT at concentrations of 0.01, 0.5 and 1 wt.%. To evaluate the antimicrobial properties of composites containing nanoparticles, the disk agar diffusion test was used. For this purpose, 10 discs from each concentration of nano-composites (totally 30 discs) and 10 discs from conventional composite (as the control group) were prepared. Then the diameter of streptococcus mutans growth inhibition around each disc was determined in blood agar medium. To evaluate the shear bond strength, with each concentration of nano-composites as well as the control group (conventional composite), 10 metal brackets were bonded to the human premolars and shear bond strength was determined using a universal testing machine. Nano-composites in all three concentrations showed significant antimicrobial effect compared to the control group ( p nano-composites compared to control group ( p = 0.695). Incorporating CuO nanoparticles into adhesive in all three studied concentrations added antimicrobial effects to the adhesive with no adverse effects on shear bond strength.

Superior sealing effect of hydroxyapatite in porous-coated implants

DEFF Research Database (Denmark)

Rahbek, Ole; Kold, Søren; Bendix, Knud

2005-01-01

Migration of wear debris to the periprosthetic bone is a major cause of osteolysis and implant failure. Both closed-pore porous coatings and hydroxyapatite (HA) coatings have been claimed to prevent the migration of wear debris. We investigated whether HA could augment the sealing effect of a por......Migration of wear debris to the periprosthetic bone is a major cause of osteolysis and implant failure. Both closed-pore porous coatings and hydroxyapatite (HA) coatings have been claimed to prevent the migration of wear debris. We investigated whether HA could augment the sealing effect...

Electrochemical Approach for Effective Antifouling and Antimicrobial Surfaces.

Science.gov (United States)

Gaw, Sheng Long; Sarkar, Sujoy; Nir, Sivan; Schnell, Yafit; Mandler, Daniel; Xu, Zhichuan J; Lee, Pooi See; Reches, Meital

2017-08-09

Biofouling, the adsorption of organisms to a surface, is a major problem today in many areas of our lives. This includes: (i) health, as biofouling on medical device leads to hospital-acquired infections, (ii) water, since the accumulation of organisms on membranes and pipes in desalination systems harms the function of the system, and (iii) energy, due to the heavy load of the organic layer that accumulates on marine vessels and causes a larger consumption of fuel. This paper presents an effective electrochemical approach for generating antifouling and antimicrobial surfaces. Distinct from previously reported antifouling or antimicrobial electrochemical studies, we demonstrate the formation of a hydrogen gas bubble layer through the application of a low-voltage square-waveform pulses to the conductive surface. This electrochemically generated gas bubble layer serves as a separation barrier between the surroundings and the target surface where the adhesion of bacteria can be deterred. Our results indicate that this barrier could effectively reduce the adsorption of bacteria to the surface by 99.5%. We propose that the antimicrobial mechanism correlates with the fundamental of hydrogen evolution reaction (HER). HER leads to an arid environment that does not allow the existence of live bacteria. In addition, we show that this drought condition kills the preadhered bacteria on the surface due to water stress. This work serves as the basis for the exploration of future self-sustainable antifouling techniques such as incorporating it with photocatalytic and photoelectrochemical reactions.

Comparative studies on structural properties and antimicrobial potential of spinel ferrite nanoparticles synthesized using various methods

Science.gov (United States)

Baraliya, Jagdish D.; Rakhashiya, Purvi M.; Patel, Pooja P.; Thaker, Vrinda S.; Joshi, Hiren H.

2017-05-01

In this study, novel multifunctional magnetic iron-based nanoparticles (CoFe2O4) coated with silica, silica-DEG (diethylene glycol), PEG (polyethylene glycol) were synthesized using Auto Combustion Method (ACM), Co-precipitation Method (COPM), Citrate Precursor Method (CPM), Flash Combustion Method (FCM). These spinel ferrite nanoparticles also contain very high antibacterial properties to fulfill the requirements of a drug delivery system so that the antibiotic concentration could be minimized. A potential delivery system could be based on a ferromagnetic fluid. The effects of various preparation methods on the physical properties of the nanoparticles were examined. The nanoparticles were also tested against four human pathogenic bacteria (Gram negative E.coli, P. aeruginosa, Gram positive S. aureus, S. pyogenus) and two fungi (C. albicans, A.niger). It was revealed that a nanoparticle has strong antibacterial activity as compared to antifungal. Further, Gram positive bacteria are more affected than Gram negative bacteria. It was also clear that different methods of coating have great influence on the antimicrobial properties. It was observed that these nanoparticles have significantly different but potentially very high antimicrobial activities against the tested organisms than found elsewhere by other nanoparticles on the same organisms.

Novel silver-based nanoclay as an antimicrobial in polylactic acid food packaging coatings.

Science.gov (United States)

Busolo, Maria A; Fernandez, Patricia; Ocio, Maria J; Lagaron, Jose M

2010-11-01

This paper presents a comprehensive performance study of polylactic acid (PLA) biocomposites, obtained by solvent casting, containing a novel silver-based antimicrobial layered silicate additive for use in active food packaging applications. The silver-based nanoclay showed strong antimicrobial activity against Gram-negative Salmonella spp. Despite the fact that no exfoliation of the silver-based nanoclay in PLA was observed, as suggested by transmission electron microscopy (TEM) and wide angle X-ray scattering (WAXS) experiments, the additive dispersed nicely throughout the PLA matrix to a nanoscale, yielding nanobiocomposites. The films were highly transparent with enhanced water barrier and strong biocidal properties. Silver migration from the films to a slightly acidified water medium, considered an aggressive food simulant, was measured by stripping voltammetry. Silver migration accelerated after 6 days of exposure. Nevertheless, the study suggests that migration levels of silver, within the specific migration levels referenced by the European Food Safety Agency (EFSA), exhibit antimicrobial activity, supporting the potential application of this biocidal additive in active food-packaging applications to improve food quality and safety.

Antiproliferative, Antimicrobial and Apoptosis Inducing Effects of Compounds Isolated from Inula viscosa

Directory of Open Access Journals (Sweden)

Wamidh H. Talib

2012-03-01

Full Text Available The antiproliferative and antimicrobial effects of thirteen compounds isolated from Inula viscosa (L. were tested in this study. The antiproliferative activity was tested against three cell lines using the MTT assay. The microdilution method was used to study the antimicrobial activity against two Gram positive bacteria, two Gram negative bacteria and one fungus. The apoptotic activity was determined using a TUNEL colorimetric assay. Scanning electron microscopy was used to study the morphological changes in treated cancer cells and bacteria. Antiproliferative activity was observed in four flavonoids (nepetin, 3,3′-di-O-methylquercetin, hispidulin, and 3-O-methylquercetin. 3,3′-di-O-Methylquercetin and 3-O-methylquercetin showed selective antiproliferative activity against MCF-7 cells, with IC50 values of 10.11 and 11.23 µg/mL, respectively. Both compounds exert their antiproliferative effect by inducing apoptosis as indicted by the presence of DNA fragmentation, nuclear condensation, and formation of apoptotic bodies in treated cancer cells. The antimicrobial effect of Inula viscosa were also noticed in 3,3′-di-O-methylquercetin and 3-O-methyquercetin that inhibited Bacillus cereus at MIC of 62.5 and 125 µg/mL, respectively. Salmonella typhimurium was inhibited by both compounds at MIC of 125 µg/mL. 3,3′-di-O-Methylquercetin induced damage in bacterial cell walls and cytoplasmic membranes. Methylated quercetins isolated from Inula viscosa have improved anticancer and antimicrobial properties compared with other flavonoids and are promising as potential anticancer and antimicrobial agents.

Chlorhexidine-releasing implant coating on intramedullary nail reduces infection in a rat model

Directory of Open Access Journals (Sweden)

SM Shiels

2018-03-01

Full Text Available The use of internal intramedullary nails for long bone fracture fixation is a common practice among surgeons. Bacteria naturally attach to these devices, increasing the risk for wound infection, which can result in non- or malunion, additional surgical procedures and extended hospital stays. Intramedullary nail surface properties can be modified to reduce bacterial colonisation and potentially infectious complications. In the current study, a coating combining a non-fouling property with leaching chlorhexidine for orthopaedic implantation was tested. Coating stability and chlorhexidine release were evaluated in vitro. Using a rat model of intramedullary fixation and infection, the effect of the coating on microbial colonisation and fracture healing was evaluated in vivo by quantitative microbiology, micro-computed tomography, plain radiography, three-point bending and/or histology. Low dose systemic cefazolin was administered to increase the similarities to clinical practice, without overshadowing the effect of the anti-infective coating. When introduced into a contaminated wound, the non-fouling chlorhexidine-coated implant reduced the overall bacteria colonisation within the bone and on the implant, reduced the osteolysis and increased the radiographic union, confirming its potential for reducing complications in wounds at high risk of infection. However, when implanted into a sterile wound, non-union increased. Further studies are required to best optimise the anti-microbial effectiveness, while not sacrificing fracture union.

Change in interfacial properties of polymer antifouling coating by controlling ring architecture of functional nanocomposites

International Nuclear Information System (INIS)

Yin, Bing; Zhang, Li; Liu, Tao; Li, Jing

2014-01-01

Greener protocols, long duration and applications are the necessary conditions of antifouling coating. The stability of anti-bacterial function decides its duration. Core–shell structured nanoparticles with Ag NPs and Ag + were successfully in situ fabricated in polyelectrolyte matrix, to avoid antimicrobial nanomaterials leaching out in the form of Ag or Ag + from the matrix. The nanocomposite materials prepared were well characterized by XRD, XPS, TEM and UV–visible. Through monitoring the hybrid polymer films soaked in the solution, sparingly soluble AgI as the shell in the hybrid structure nanoparticles showed excellent barrier effect. Using the synergy of Ag NPs and Ag + toward the killing of microbes, the duration of antimicrobial activity was prolonged. (paper)

Antimicrobial compounds targeting Gram-negative bacteria in food: Their mode of action and combinational effects

DEFF Research Database (Denmark)

Hyldgaard, Morten

2015-01-01

compromising food shelf-life or safety. Natural antimicrobial compounds have therefore gained increased interest as a label-friendly alternative that can be added directly to food products. Although natural antimicrobials constitute an interesting source of compounds, it is often not understood how...... they interact with bacterial cells to exert their mechanism of inhibition or killing. Furthermore, natural antimicrobials are often not potent enough as single compounds, and may cause unwanted sensory side-effects, which limit the quantities that can be applied to food. These problems might be circumvented...... by combining antimicrobials to decrease the concentrations needed without compromising their antimicrobial activity. The work described in this dissertation presents two projects concerning the mechanism of action of selected natural antimicrobial compounds primarily against Gram-negative bacteria, and two...

Space Environmental Effects on Coated Tether Materials

Science.gov (United States)

Gittemeier, Keith A.; Hawk, Clark W.; Finckenor, Miria M.; Watts, Ed

2005-01-01

The University of Alabama in Huntsville s Propulsion Research Center has teamed with NASA's Marshall Space Flight Center (MSFC) to research the effects of atomic oxygen (AO) bombardment on coated tether materials. Tethers Unlimited Inc. has provided several candidate tether materials with various coatings for AO exposure in MSFC s Atomic Oxygen Beam Facility. Additional samples were exposed to ultraviolet (UV) radiation at MSFC. AO erodes most organic materials, and ultraviolet radiation embrittles polymers. This test series was performed to determine the effect of AO and UV on the mechanical integrity of tether materials that were treated with AO-protective coatings, such as polyhedral oligomeric silsesquioxane (POSS) or metallization. Both TUI's Multi-Application Survivable Tether (MAST) Experiment and Marshall Space Flight Center s Momentum Exchange Electrodynamic Reboost (MXER) programs will benefit from this research by helping to determine tether materials and coatings that give the longest life with the lowest mass penalty.

Antimicrobial effect of probiotics on bacterial species from dental plaque.

Science.gov (United States)

Zambori, Csilla; Morvay, Attila Alexandru; Sala, Claudia; Licker, Monica; Gurban, Camelia; Tanasie, Gabriela; Tirziu, Emil

2016-03-31

The antimicrobial role of probiotic Lactobacillus casei subspecies casei DG (L. casei DG) and of the mix culture of probiotic Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 was tested on species of Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera from supragingival sites from dogs with dental disease of different breed, age, sex, weight, and diet. The research was conducted on these four genera because of their importance in zoonotic infections after dog bites. Species from Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera were isolated and identified. To test the antimicrobial efficacy of L. casei DG and the mixed culture of probiotic L. acidophilus LA-5 and Bifidobacterium bifidum BB-12 on the pathogenic species, the agar overlay method was used. L. casei DG had a bactericidal effect on all analyzed species isolated from Staphylococcus, Streptococcus, Pasteurella, and Neisseria genera after 24 hours of incubation. The mixed probiotic culture made up of L. acidophilus LA-5 and Bifidobacterium BB-12 species had no bactericidal effect on the species of Staphylococcus and Streptococcus genera, which were resistant. However, it had a bacteriostatic effect on several species of Pasteurella and Neisseria genera. This work highlights the antimicrobial potential of probiotics in vitro, demonstrating that the probiotic L. casei DG has a bactericidal effect on all analyzed species isolated from dental plaque and that the mix culture of probiotic L. acidophilus LA-5 and Bifidobacterium BB-12 has only a bacteriostatic effect.

Nanostructured thin film coatings with different strengthening effects

Directory of Open Access Journals (Sweden)

Panfilov Yury

2017-01-01

Full Text Available A number of articles on strengthening thin film coatings were analyzed and a lot of unusual strengthening effects, such as super high hardness and plasticity simultaneously, ultra low friction coefficient, high wear-resistance, curve rigidity increasing of drills with small diameter, associated with process formation of nanostructured coatings by the different thin film deposition methods were detected. Vacuum coater with RF magnetron sputtering system and ion-beam source and arc evaporator for nanostructured thin film coating manufacture are represented. Diamond Like Carbon and MoS2 thin film coatings, Ti, Al, Nb, Cr, nitride, carbide, and carbo-nitride thin film materials are described as strengthening coatings.

Effect of salivary pH on diametral tensile strength of glass ionomer cement coated with coating agent

Science.gov (United States)

Farahdillah; Triaminingsih, S.; Eriwati, Y. K.

2017-08-01

The aim of this study was to analyze the effect of salivary pH to diametral tensile strength of glass ionomer cement (GIC) coated with a coating agent. GIC specimens coated with varnish and nano-filled coating agent were stored in artificial saliva at pH values of 4.5, 5.5, and 7 for 24 h at 37°C, then the diametral tensile strength was tested by universal testing machine. Results showed that there was no significant difference in the diametral tensile strength of the GIC coated with varnish and nano-filled coating agent with decreasing of salivary pH (p salivary pH does not affect the diametral tensile strength of GIC coated by varnish or nano-filled coating agent

Hydrophobization and antimicrobial activity of chitosan and paper-based packaging material.

Science.gov (United States)

Bordenave, Nicolas; Grelier, Stephane; Coma, Veronique

2010-01-11

This study reports the elaboration of water-resistant, antimicrobial, chitosan and paper-based materials as environmentally friendly food packaging materials. Two types of papers were coated with chitosan-palmitic acid emulsions or with a blend of chitosan and O,O'-dipalmitoylchitosan (DPCT). Micromorphology studies showed that inclusion of hydrophobic compounds into the chitosan matrix was enhanced by grafting them onto chitosan and that this led to their penetration of the paper's core. Compared to chitosan-coated papers, the coating of chitosan-palmitic emulsion kept vapor-barrier properties unchanged (239 and 170 g.m(-2).d(-1) versus 241 and 161 g.m(-2).d(-1)), while the coating of chitosan-DPCT emulsion dramatically deteriorated them (441 and 442 g.m(-2).d(-1)). However, contact angle measurements (110-120 degrees after 1 min) and penetration dynamics analysis showed that both strategies improved liquid-water resistance of the materials. Kit-test showed that all hydrophobized chitosan-coated papers kept good grease barrier properties (degree of resistance 6-8/12). Finally, all chitosan-coated materials exhibited over 98% inhibition on Salmonella Typhimurium and Listeria monocytogenes .

Antibacterial and Tribological Performance of Carbonitride Coatings Doped with W, Ti, Zr, or Cr Deposited on AISI 316L Stainless Steel

Science.gov (United States)

Yao, Sun-Hui; Su, Yen-Liang; Lai, Yu-Cheng

2017-01-01

Carbonitride (CNx) coatings have existed for several decades but are not well understood. Related studies have indicated that CNx coatings exhibit behaviors comparable to diamond-like carbon (DLC) coatings. Metal-doped CNx coatings are expected to show superior performance to single CNx coatings. In this study, a CNx coating and a group of CNx coatings with 6 at. % metal doping (W, Ti, Zr, or Cr) were prepared on biograde AISI 316L stainless steel (SS316L) substrates, and they were then characterized and studied for antibacterial and wear performance. The microstructure, constituent phase, nanohardness, adhesion, surface roughness, and contact angle were evaluated. The antimicrobial test used Staphylococcus aureus and followed the Japanese Industrial Standard JIS Z 2801:2010. Finally, the wear behavior was assessed. The results showed that the CNx coating was a composite of amorphous CNx and amorphous C structures. The metal doping caused crystalline metal carbides/nitrides to form in the CNx coatings, which weakened their overall integrity. All the coatings showed antimicrobial ability for the SS316L samples. The CNx-Zr coating, the surface of which had the highest hydrophilicity, produced the best antibacterial performance. However, the CNx-Zr coating showed lower wear resistance than the CNx-W and CNx-Ti coatings. The CNx-Ti coating with a highly hydrophilic surface exhibited the lowest antibacterial ability. PMID:29039782

Antibacterial and Tribological Performance of Carbonitride Coatings Doped with W, Ti, Zr, or Cr Deposited on AISI 316L Stainless Steel

Directory of Open Access Journals (Sweden)

Sun-Hui Yao

2017-10-01

Full Text Available Carbonitride (CNx coatings have existed for several decades but are not well understood. Related studies have indicated that CNx coatings exhibit behaviors comparable to diamond-like carbon (DLC coatings. Metal-doped CNx coatings are expected to show superior performance to single CNx coatings. In this study, a CNx coating and a group of CNx coatings with 6 at. % metal doping (W, Ti, Zr, or Cr were prepared on biograde AISI 316L stainless steel (SS316L substrates, and they were then characterized and studied for antibacterial and wear performance. The microstructure, constituent phase, nanohardness, adhesion, surface roughness, and contact angle were evaluated. The antimicrobial test used Staphylococcus aureus and followed the Japanese Industrial Standard JIS Z 2801:2010. Finally, the wear behavior was assessed. The results showed that the CNx coating was a composite of amorphous CNx and amorphous C structures. The metal doping caused crystalline metal carbides/nitrides to form in the CNx coatings, which weakened their overall integrity. All the coatings showed antimicrobial ability for the SS316L samples. The CNx-Zr coating, the surface of which had the highest hydrophilicity, produced the best antibacterial performance. However, the CNx-Zr coating showed lower wear resistance than the CNx-W and CNx-Ti coatings. The CNx-Ti coating with a highly hydrophilic surface exhibited the lowest antibacterial ability.

Efficient fabrication of transparent antimicrobial poly(vinyl alcohol) thin films

International Nuclear Information System (INIS)

Liu Shuxia; He Junhui; Xue Jianfeng; Ding Wenjun

2009-01-01

We have explored in situ synthesis of Ag nanoparticles in transparent PVA films in view of increasing areas of application of those films. The two-step procedure consists of ion incorporation in the matrix and subsequent thermal reduction. Smooth and transparent PVA films containing Ag nanoparticles of 5-20 nm were fabricated by this approach. The optical property of the films and the size of metal nanoparticles could be controlled by changing the reaction conditions. By increasing heating temperature, the absorbance and wavelength of surface plasmon resonance (SPR) of the composite film increased, and nanoparticles with larger particle sizes and broader size distributions were obtained. In the temperature range of 130-170 o C, the wavelength of SPR increased with increasing the AgNO 3 concentration. At 190 o C, however, the wavelenght of SPR blue-shifted initially when the AgNO 3 concentration increased from 10 to 80 mmol/L, and red-shifted thereafter. The composite films showed excellent antimicrobial performance toward bacteria such as Escherchia coli. Such hybrids afford very effective and environment-friendly antimicrobial surface coatings.

Structural, compositional, mechanical characterization and biological assessment of bovine-derived hydroxyapatite coatings reinforced with MgF_2 or MgO for implants functionalization

International Nuclear Information System (INIS)

Mihailescu, Natalia; Stan, G.E.; Duta, L.; Chifiriuc, Mariana Carmen; Bleotu, Coralia; Sopronyi, M.; Luculescu, C.; Oktar, F.N.; Mihailescu, I.N.

2016-01-01

Hydroxyapatite (HA) is a consecrated biomaterial for bone reconstruction. In the form of thin films deposited by pulsed laser technologies, it can be used to cover metallic implants aiming to increase biocompatibility and osseointegration rate. HA of animal origin (bovine, BHA) reinforced with MgF_2 (2 wt.%) or MgO (5 wt.%) were used for deposition of thin coatings with improved adherence, biocompatibility and antimicrobial activity. For pulsed laser deposition experiments, a KrF* (λ = 248 nm, τ_F_W_H_M ≤ 25 ns) excimer laser source was used. The deposited structures were characterized from a physical–chemical point of view by X-Ray Diffraction, Fourier Transform Infra-Red Spectroscopy, Scanning Electron Microscopy in top- and cross-view modes, Energy Dispersive X-Ray Spectroscopy and Pull-out adherence tests. The microbiological assay using the HEp-2 cell line revealed that all target materials and deposited thin films are non-cytotoxic. We conducted tests on three strains isolated from patients with dental implants failure, i.e. Microccocus sp., Enterobacter sp. and Candida albicans sp. The most significant anti-biofilm effect against Microcococcus sp. strain, at 72 h, was obtained in the presence of BHA:MgO thin films. For Enterobacter sp. strain a superior antimicrobial activity at 72 h was noticed, in respect with simple BHA or Ti control. The enhanced antimicrobial performances, correlated with good cytocompatibility and mechanical properties recommend these biomaterials as an alternative to synthetic HA for the fabrication of reliable implant coatings for dentistry and other applications. - Highlights: • Novel biological derived HA coatings fabricated by pulsed laser deposition. • Renewable resources • Reinforcement with MgF_2 and MgO improves the HA coatings' bonding strength. • Significant anti-biofilm effect obtained for MgO reinforced HA films. • Alternative low cost solutions for a new generation of dental implants.

Can a novel silver nano coating reduce infections and maintain cell viability in vitro?

Science.gov (United States)

Qureshi, Ammar T; Landry, Jace P; Dasa, Vinod; Janes, Marlene; Hayes, Daniel J

2014-03-01

Herein we report a facile layer-by-layer method for creating an antimicrobial coating composed of silver nanoparticles on medical grade titanium test discs. Nanoscale silver nanoparticle layers are attached to the titanium orthopedic implant material via aminopropyltriethoxy silane crosslinker that reacts with neighboring silane moieties to create an interconnected network. A monolayer of silane, followed by a monolayer of silver nanoparticles would form one self-assembled layer and this process can be repeated serially, resulting in increased silver nanoparticles deposition. The release rate of silver ion increases predictably with increasing numbers of layers and at appropriate thicknesses these coatings demonstrate 3-4 log reduction of viable Escherichia coli and Staphylococcus aureus bacteria. Increasing the thickness of the coatings resulted in reduced bacterial colonization as determined by fluorescent staining and image analysis. Interestingly, the cytotoxicity of murine 3T3 cells as quantified by fluorescent staining and flow cytometry, was minimal and did not vary significantly with the coating thickness. Additionally, these coatings are mechanically stable and resist delamination by orthogonal stress test. This simple layer-by-layer coating technique may provide a cost-effective and biocompatible method for reducing microbial colonization of implantable orthopedic devices.

An effective zinc phthalocyanine derivative for photodynamic antimicrobial chemotherapy

International Nuclear Information System (INIS)

Chen, Zhuo; Zhou, Shanyong; Chen, Jincan; Li, Linsen; Hu, Ping; Chen, Song; Huang, Mingdong

2014-01-01

Bacterial infection is a common clinical problem. The emergence of antibiotic resistant bacteria posts a severe challenge to medical practice worldwide. Photodynamic antimicrobial chemotherapy (PACT) uses laser light at specific wavelength to activate oxygen molecule in the human tissue into reactive oxygen species as antimicrobial agent. This activation of oxygen by laser light is mediated through a photosensitizer. Two key properties for potent photosensitizer are its absorbance of light in the infrared region (630–700 nm), which promotes tissue penetration depth, and the selective accumulation on bacteria instead of human tissue. We herein report a zinc phthalocyanine derivative, pentalysine β-carbonylphthalocyanine zinc (ZnPc-(Lys) 5 ) and its antimicrobial effects in vitro and in an animal infection model. This photosensitizer has strong capability to kill bacteria at 670 nm. Chemically, it is a water-soluble and cationic photosensitizer carrying positive charge under physiological pH, and can specifically target to bacteria which usually bears negative charges on its surface. Compared with anionic ZnPc counterparts, ZnPc-(Lys) 5 shows a higher phototoxicity toward bacteria. PACT studies of ZnPc-(Lys) 5 in experimental infection animal model showed a significant bacteria inhibition compared to controls, and high selectivity of ZnPc-(Lys) 5 toward bacteria. These findings suggest ZnPc-(Lys) 5 is a promising antimicrobial photosensitizer for the treatment of infectious diseases. - Highlights: • Photodynamic antimicrobial chemotherapy (PACT) with water-soluble zinc phthalocyanine derivative offers a promising measure to deal with antibiotic resistance of bacteria. • The use of portable LED light sources that are battery-powered and with low cost may make possible the deployment of systems that can be used for wound decontamination. • ZnPc-(Lys) 5 is a potent photosensitizer for treatment of infectious diseases

An effective zinc phthalocyanine derivative for photodynamic antimicrobial chemotherapy

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhuo, E-mail: zchen@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Zhou, Shanyong; Chen, Jincan [State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Li, Linsen [Department of Biochemistry, Shenyang Medical College, Shenyang, Liaoning 110034 (China); Hu, Ping; Chen, Song [State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang, Mingdong, E-mail: mhuang@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2014-08-01

Bacterial infection is a common clinical problem. The emergence of antibiotic resistant bacteria posts a severe challenge to medical practice worldwide. Photodynamic antimicrobial chemotherapy (PACT) uses laser light at specific wavelength to activate oxygen molecule in the human tissue into reactive oxygen species as antimicrobial agent. This activation of oxygen by laser light is mediated through a photosensitizer. Two key properties for potent photosensitizer are its absorbance of light in the infrared region (630–700 nm), which promotes tissue penetration depth, and the selective accumulation on bacteria instead of human tissue. We herein report a zinc phthalocyanine derivative, pentalysine β-carbonylphthalocyanine zinc (ZnPc-(Lys){sub 5}) and its antimicrobial effects in vitro and in an animal infection model. This photosensitizer has strong capability to kill bacteria at 670 nm. Chemically, it is a water-soluble and cationic photosensitizer carrying positive charge under physiological pH, and can specifically target to bacteria which usually bears negative charges on its surface. Compared with anionic ZnPc counterparts, ZnPc-(Lys){sub 5} shows a higher phototoxicity toward bacteria. PACT studies of ZnPc-(Lys){sub 5} in experimental infection animal model showed a significant bacteria inhibition compared to controls, and high selectivity of ZnPc-(Lys){sub 5} toward bacteria. These findings suggest ZnPc-(Lys){sub 5} is a promising antimicrobial photosensitizer for the treatment of infectious diseases. - Highlights: • Photodynamic antimicrobial chemotherapy (PACT) with water-soluble zinc phthalocyanine derivative offers a promising measure to deal with antibiotic resistance of bacteria. • The use of portable LED light sources that are battery-powered and with low cost may make possible the deployment of systems that can be used for wound decontamination. • ZnPc-(Lys){sub 5} is a potent photosensitizer for treatment of infectious diseases.

Structural, compositional, mechanical characterization and biological assessment of bovine-derived hydroxyapatite coatings reinforced with MgF{sub 2} or MgO for implants functionalization

Energy Technology Data Exchange (ETDEWEB)

Mihailescu, Natalia [National Institute for Lasers, Plasma and Radiation Physics, Magurele RO-077125 (Romania); Stan, G.E. [National Institute of Materials Physics, Magurele RO-077125 (Romania); Duta, L. [National Institute for Lasers, Plasma and Radiation Physics, Magurele RO-077125 (Romania); Chifiriuc, Mariana Carmen [Department of Microbiology, Faculty of Biology, Bucharest RO-060101 (Romania); Bleotu, Coralia [Stefan S. Nicolau Institute of Virology, 85 Mihai Bravu Avenue, Bucharest RO-030304 (Romania); Sopronyi, M.; Luculescu, C. [National Institute for Lasers, Plasma and Radiation Physics, Magurele RO-077125 (Romania); Oktar, F.N. [Department of Bioengineering, Faculty of Engineering, Marmara University, Goztepe, Istanbul TR-34722 (Turkey); Advance Nanomaterials Research Laboratory, Marmara University, Goztepe, Istanbul TR-34722 (Turkey); Mihailescu, I.N., E-mail: ion.mihailescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Magurele RO-077125 (Romania)

2016-02-01

Hydroxyapatite (HA) is a consecrated biomaterial for bone reconstruction. In the form of thin films deposited by pulsed laser technologies, it can be used to cover metallic implants aiming to increase biocompatibility and osseointegration rate. HA of animal origin (bovine, BHA) reinforced with MgF{sub 2} (2 wt.%) or MgO (5 wt.%) were used for deposition of thin coatings with improved adherence, biocompatibility and antimicrobial activity. For pulsed laser deposition experiments, a KrF* (λ = 248 nm, τ{sub FWHM} ≤ 25 ns) excimer laser source was used. The deposited structures were characterized from a physical–chemical point of view by X-Ray Diffraction, Fourier Transform Infra-Red Spectroscopy, Scanning Electron Microscopy in top- and cross-view modes, Energy Dispersive X-Ray Spectroscopy and Pull-out adherence tests. The microbiological assay using the HEp-2 cell line revealed that all target materials and deposited thin films are non-cytotoxic. We conducted tests on three strains isolated from patients with dental implants failure, i.e. Microccocus sp., Enterobacter sp. and Candida albicans sp. The most significant anti-biofilm effect against Microcococcus sp. strain, at 72 h, was obtained in the presence of BHA:MgO thin films. For Enterobacter sp. strain a superior antimicrobial activity at 72 h was noticed, in respect with simple BHA or Ti control. The enhanced antimicrobial performances, correlated with good cytocompatibility and mechanical properties recommend these biomaterials as an alternative to synthetic HA for the fabrication of reliable implant coatings for dentistry and other applications. - Highlights: • Novel biological derived HA coatings fabricated by pulsed laser deposition. • Renewable resources • Reinforcement with MgF{sub 2} and MgO improves the HA coatings' bonding strength. • Significant anti-biofilm effect obtained for MgO reinforced HA films. • Alternative low cost solutions for a new generation of dental implants.

Novel natural food antimicrobials.

Science.gov (United States)

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

2012-01-01

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

GMI effect in CuO coated Co-based amorphous ribbons

Energy Technology Data Exchange (ETDEWEB)

Taysioglu, Asli Ayten [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Peksoz, Ahmet, E-mail: peksoz@uludag.edu.t [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Kaya, Yunus [Department of Chemistry, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Derebasi, Naim [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Irez, Gazi [Department of Chemistry, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey); Kaynak, Gokay [Department of Physics, Sciences and Arts Faculty, Uludag University, 16059 Gorukle, Bursa (Turkey)

2009-11-13

A Copper oxide (CuO) film has been grown on a surface of Co-based amorphous ribbon using chemical successive ionic layer adsorption and reaction technique, at room temperature and atmosphere pressure. The influence of coating and width of ribbon on giant magneto impedance have been investigated over a frequency range from 0.1 to 3 MHz and under a static magnetic field between -8 and +8 kA/m. The results showed that Co-based amorphous ribbons, which are coated CuO film, have a significant effect on the magnitude and operation frequency for the giant magneto impedance effect as compared to the samples without coating. The highest giant magneto impedance effect was found to be 14.90 on 5 mm width coated ribbon, which is 60% higher than the sample without coating. A surface observation of these samples has been carried out by an atomic force microscope. The AFM images reveal the difference between surfaces of coated and as-cast sample.

GMI effect in CuO coated Co-based amorphous ribbons

International Nuclear Information System (INIS)

Taysioglu, Asli Ayten; Peksoz, Ahmet; Kaya, Yunus; Derebasi, Naim; Irez, Gazi; Kaynak, Gokay

2009-01-01

A Copper oxide (CuO) film has been grown on a surface of Co-based amorphous ribbon using chemical successive ionic layer adsorption and reaction technique, at room temperature and atmosphere pressure. The influence of coating and width of ribbon on giant magneto impedance have been investigated over a frequency range from 0.1 to 3 MHz and under a static magnetic field between -8 and +8 kA/m. The results showed that Co-based amorphous ribbons, which are coated CuO film, have a significant effect on the magnitude and operation frequency for the giant magneto impedance effect as compared to the samples without coating. The highest giant magneto impedance effect was found to be 14.90 on 5 mm width coated ribbon, which is 60% higher than the sample without coating. A surface observation of these samples has been carried out by an atomic force microscope. The AFM images reveal the difference between surfaces of coated and as-cast sample.

Controversies in Antimicrobial Stewardship: Focus on New Rapid Diagnostic Technologies and Antimicrobials

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Eric Wenzler

2016-01-01

Full Text Available Antimicrobial stewardship programs (ASPs are challenged with ensuring appropriate antimicrobial use while minimizing expenditures. ASPs have consistently demonstrated improved patient outcomes and significant cost reductions but are continually required to justify the costs of their existence and interventions due to the silo mentality often adopted by hospital administrators. As new technologies and antimicrobials emerge, ASPs are in a constant tug-of-war between providing optimal clinical outcomes and ensuring cost containment. Additionally, robust data on cost-effectiveness of new rapid diagnostic technologies and antimicrobials with subsequent ASP interventions to provide justification are lacking. As the implementation of an ASP will soon be mandatory for acute care hospitals in the United States, ASPs must find ways to justify novel interventions to align themselves with healthcare administrators. This review provides a framework for the justification of implementing a rapid diagnostic test or adding a new antimicrobial to formulary with ASP intervention, reviews approaches to demonstrating cost-effectiveness, and proposes methods for which ASPs may reduce healthcare expenditures via alternative tactics.

Antimicrobial Effects of Helix D-derived Peptides of Human Antithrombin III*

Science.gov (United States)

Papareddy, Praveen; Kalle, Martina; Bhongir, Ravi K. V.; Mörgelin, Matthias; Malmsten, Martin; Schmidtchen, Artur

2014-01-01

Antithrombin III (ATIII) is a key antiproteinase involved in blood coagulation. Previous investigations have shown that ATIII is degraded by Staphylococcus aureus V8 protease, leading to release of heparin binding fragments derived from its D helix. As heparin binding and antimicrobial activity of peptides frequently overlap, we here set out to explore possible antibacterial effects of intact and degraded ATIII. In contrast to intact ATIII, the results showed that extensive degradation of the molecule yielded fragments with antimicrobial activity. Correspondingly, the heparin-binding, helix d-derived, peptide FFFAKLNCRLYRKANKSSKLV (FFF21) of human ATIII, was found to be antimicrobial against particularly the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Fluorescence microscopy and electron microscopy studies demonstrated that FFF21 binds to and permeabilizes bacterial membranes. Analogously, FFF21 was found to induce membrane leakage of model anionic liposomes. In vivo, FFF21 significantly reduced P. aeruginosa infection in mice. Additionally, FFF21 displayed anti-endotoxic effects in vitro. Taken together, our results suggest novel roles for ATIII-derived peptide fragments in host defense. PMID:25202017

Sakacin-A antimicrobial packaging for decreasing Listeria contamination in thin-cut meat: preliminary assessment.

Science.gov (United States)

Barbiroli, Alberto; Musatti, Alida; Capretti, Giorgio; Iametti, Stefania; Rollini, Manuela

2017-02-01

Minimally processed ready-to-eat products are considered a high-risk food because of the possibility of contamination with pathogenic bacteria, including Listeria monocytogenes from the animal reservoir, and the minimal processing they undergo. In this study, a sakacin-A anti-Listeria active package was developed and tested on thin-cut veal meat slices (carpaccio). Enriched food-grade sakacin-A was obtained from a cell-free supernatant of a Lactobacillus sakei culture and applied (0.63 mg cm -2 ) onto the surface of polyethylene-coated paper sheets to obtain an active antimicrobial package. The coating retained antimicrobial features, indicating that the process did not affect sakacin-A functionality, as evidenced in tests carried out in vitro. Thin-cut veal meat slices inoculated with Listeria innocua (a surrogate of pathogenic L. monocytogenes) were laid on active paper sheets. After 48 h incubation at 4 °C, the Listeria population was found to be 1.5 log units lower with respect to controls (3.05 vs 4.46 log colony-forming units (CFU) g -1 ). This study demonstrates the possibility of using an antimicrobial coating containing sakacin-A to inhibit or decrease the Listeria population in ready-to-eat products, thus lowering the risk of food-related diseases. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Silver nanoparticles as a medical device in healthcare settings: a five-step approach for candidate screening of coating agents

Science.gov (United States)

Marassi, Valentina; Di Cristo, Luisana; Smith, Stephen G. J.; Ortelli, Simona; Blosi, Magda; Costa, Anna L.; Reschiglian, Pierluigi; Volkov, Yuri; Prina-Mello, Adriele

2018-01-01

Silver nanoparticle-based antimicrobials can promote a long lasting bactericidal effect without detrimental toxic side effects. However, there is not a clear and complete protocol to define and relate the properties of the particles (size, shape, surface charge, ionic content) with their specific activity. In this paper, we propose an effective multi-step approach for the identification of a `purpose-specific active applicability window' to maximize the antimicrobial activity of medical devices containing silver nanoparticles (Ag NPs) (such as surface coaters), minimizing any consequent risk for human health (safety by design strategy). The antimicrobial activity and the cellular toxicity of four types of Ag NPs, differing in their coating composition and concentration have been quantified. Through the implementation of flow-field flow fractionation, Ag NPs have been characterized in terms of metal release, size and shape. The particles are fractionated in the process while being left unmodified, allowing for the identification of biological particle-specific contribution. Toxicity and inflammatory response in vitro have been assessed on human skin models, while antimicrobial activity has been monitored with both non-pathogenic and pathogenic Escherichia coli. The main benefit associated with such approach is the comprehensive assessment of the maximal effectiveness of candidate nanomaterials, while simultaneously indexing their properties against their safety.

Antimicrobial Effects of 7,8-Dihydroxy-6-Methoxycoumarin and 7-Hydroxy-6-Methoxycoumarin Analogues against Foodborne Pathogens and the Antimicrobial Mechanisms Associated with Membrane Permeability.

Science.gov (United States)

Yang, Ji-Yeon; Park, Jun-Hwan; Lee, Myung-Ji; Lee, Ji-Hoon; Lee, Hoi-Seon

2017-10-03

The antimicrobial effects of 7,8-dihydroxy-6-methoxycoumarin and 7-hydroxy-6-methoxycoumarin isolated from Fraxinus rhynchophylla bark and of their structural analogues were determined in an attempt to develop natural antimicrobial agents against the foodborne pathogens Escherichia coli, Bacillus cereus, Staphylococcus intermedius, and Listeria monocytogenes. To elucidate the relationship between structure and antimicrobial activity for the coumarin analogues, isolated constituents and their structural analogues were evaluated against foodborne pathogens. Based on the culture plate inhibition zones and MICs, 6,7-dimethoxycoumarin, 7,8-dihydroxy-6-methoxycoumarin, 7-hydroxy-6-methoxycoumarin, and 7-methoxycoumarin, containing a methoxy functional group on the coumarin skeleton, had the notable antimicrobial activity against foodborne pathogens. However, 7-hydroxycoumarin and 6,7-dihydroxycoumarin, which contained a hydroxyl functional group on the coumarin skeleton, had no antimicrobial activity against these pathogens. An increase in cell membrane permeability was confirmed by electron microscopy observations, and release of extracellular ATP and cell constituents followed treatment with the ethyl acetate fraction of F. rhynchophylla extract. These findings indicate that F. rhynchophylla extract and coumarin analogues have potential for use as antimicrobial agents against foodborne pathogens and that the antimicrobial mechanisms are associated with the loss of cell membrane integrity.

Oral administration of antimicrobials increase antimicrobial resistance in E. coli from chicken--a systematic review.

Science.gov (United States)

Simoneit, C; Burow, E; Tenhagen, B-A; Käsbohrer, A

2015-01-01

Antimicrobials play an important role in animal and human health care. It was the aim of this systematic review to assess the effects of oral administration of antimicrobials on the development of antimicrobial resistance (AMR) in Escherichia coli (E. coli) from chickens. Moreover, the effects of the administration of more than one antimicrobial and of different dosages were studied. Literature was searched in November 2012 from the electronic databases ISI Web of Science, PubMed, Scopus and a national literature database (DIMDI) as well as the database ProQuest LLC. The search was updated in March 2014. Original studies describing a treatment (A) and a control group of either non-treatment (C) or initial value (0) and determining AMR in E. coli at different sample points (SP) were included. The literature search resulted in 35 full text articles on the topic, seven (20%) of which contained sufficient information on the administered antimicrobial and the impact of treatment on AMR. Most papers described the use of more than one antimicrobial, several dosages, controls (non-treatment or pre-treatment) and measured AMR at different SPs leading to a total of 227 SPs on the impact of the use of antimicrobials on AMR in chickens. 74% of the SPs (168/227) described a higher AMR-rate in E. coli from treated animals than from controls. After the administration of a single antimicrobial, AMR increased at 72% of the SPs. Administration of more than one antimicrobial increased AMR at 82% of the SPs. Higher dosages were associated with similar or higher AMR rates. The limited number of studies for each antimicrobial agent and the high variability in the resistance effect call for more well designed studies on the impact of oral administration on AMR development and spread. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of antimicrobial compounds tylosin and chlortetracycline during batch anaerobic swine manure digestion.

Science.gov (United States)

Stone, James J; Clay, Sharon A; Zhu, Zhenwei; Wong, Kwok L; Porath, Laura R; Spellman, Garth M

2009-10-01

Tylosin and chlortetracycline (CTC) are antimicrobial chemicals that are fed to >45% of the US swine herds at therapeutic and sub-therapeutic dosages to enhance growth rates and treat swine health problems. These compounds are poorly absorbed during digestion so that the bioactive compound or metabolites are excreted. This study investigated the degradation and stabilization of swine manure that contained no additives and compared the observed processes with those of manure containing either tylosin or CTC. The batch anaerobic incubation lasted 216 days. The breakdown of insoluble organic matter through anaerobic hydrolysis reactions was faster for manure containing CTC compared with tylosin or no-antimicrobial treatments. Volatile fatty acid (VFA) accumulation, including acetate, butyrate, and propionate, was greater for CTC-containing manure compared to tylosin and no-antimicrobial treatments. The relative abundance of two aceticlastic methanogens, Methanosaetaceae and Methanosarcinaceae spp., were less for CTC manure than manure with no-antimicrobial treatment. In addition, generation of methane and carbon dioxide was inhibited by 27.8% and 28.4%, respectively, due to the presence of CTC. Tylosin effects on manure degradation were limited, however the relative abundance of Methanosarcinaceae spp. was greater than found in the CTC or no-antimicrobial manures. These data suggest that acetate and other C-1 VFA compounds would be effectively utilized during methanogenesis in the presence of tylosin.

Antimicrobial activity of Nigerian medicinal plants

Science.gov (United States)

Anyanwu, Madubuike Umunna; Okoye, Rosemary Chinazam

2017-01-01

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

Antimicrobial Peptides in Biomedical Device Manufacturing

Science.gov (United States)

Riool, Martijn; de Breij, Anna; Drijfhout, Jan W.; Nibbering, Peter H.; Zaat, Sebastian A. J.

2017-08-01

Over the past decades the use of medical devices, such as catheters, artificial heart valves, prosthetic joints and other implants, has grown significantly. Despite continuous improvements in device design, surgical procedures and wound care, biomaterial-associated infections (BAI) are still a major problem in modern medicine. Conventional antibiotic treatment often fails due to the low levels of antibiotic at the site of infection. The presence of biofilms on the biomaterial and/or the multidrug-resistant phenotype of the bacteria further impair the efficacy of antibiotic treatment. Removal of the biomaterial is then the last option to control the infection. Clearly, there is a pressing need for alternative strategies to prevent and treat BAI. Synthetic antimicrobial peptides (AMPs) are considered promising candidates as they are active against a broad spectrum of (antibiotic-resistant) planktonic bacteria and biofilms. Moreover, bacteria are less likely to develop resistance to these rapidly-acting peptides. In this review we highlight the four main strategies, three of which applying AMPs, in biomedical device manufacturing to prevent BAI. The first involves modification of the physicochemical characteristics of the surface of implants. Immobilization of AMPs on surfaces of medical devices with a variety of chemical techniques is essential in the second strategy. The main disadvantage of these two strategies relates to the limited antibacterial effect in the tissue surrounding the implant. This limitation is addressed by the third strategy that releases AMPs from a coating in a controlled fashion. Lastly, AMPs can be integrated in the design and manufacturing of additively manufactured / 3D-printed implants, owing to the physicochemical characteristics of the implant material and the versatile manufacturing technologies compatible with antimicrobials incorporation. These novel technologies utilizing AMPs will contribute to development of novel and safe

Antimicrobial Peptides in Biomedical Device Manufacturing

Directory of Open Access Journals (Sweden)

Martijn Riool

2017-08-01

Full Text Available Over the past decades the use of medical devices, such as catheters, artificial heart valves, prosthetic joints, and other implants, has grown significantly. Despite continuous improvements in device design, surgical procedures, and wound care, biomaterial-associated infections (BAI are still a major problem in modern medicine. Conventional antibiotic treatment often fails due to the low levels of antibiotic at the site of infection. The presence of biofilms on the biomaterial and/or the multidrug-resistant phenotype of the bacteria further impair the efficacy of antibiotic treatment. Removal of the biomaterial is then the last option to control the infection. Clearly, there is a pressing need for alternative strategies to prevent and treat BAI. Synthetic antimicrobial peptides (AMPs are considered promising candidates as they are active against a broad spectrum of (antibiotic-resistant planktonic bacteria and biofilms. Moreover, bacteria are less likely to develop resistance to these rapidly-acting peptides. In this review we highlight the four main strategies, three of which applying AMPs, in biomedical device manufacturing to prevent BAI. The first involves modification of the physicochemical characteristics of the surface of implants. Immobilization of AMPs on surfaces of medical devices with a variety of chemical techniques is essential in the second strategy. The main disadvantage of these two strategies relates to the limited antibacterial effect in the tissue surrounding the implant. This limitation is addressed by the third strategy that releases AMPs from a coating in a controlled fashion. Lastly, AMPs can be integrated in the design and manufacturing of additively manufactured/3D-printed implants, owing to the physicochemical characteristics of the implant material and the versatile manufacturing technologies compatible with antimicrobials incorporation. These novel technologies utilizing AMPs will contribute to development of novel

Association between selected antimicrobial resistance genes and antimicrobial exposure in Danish pig farms

DEFF Research Database (Denmark)

Birkegård, Anna Camilla; Hisham Beshara Halasa, Tariq; Græsbøll, Kaare

2017-01-01

Bacterial antimicrobial resistance (AMR) in pigs is an important public health concern due to its possible transfer to humans. We aimed at quantifying the relationship between the lifetime exposure of antimicrobials and seven antimicrobial resistance genes in Danish slaughter pig farms. AMR gene...... levels were quantified by qPCR of total-community DNA in faecal samples obtained from 681 batches of slaughter pigs. The lifetime exposure to antimicrobials was estimated at batch level for the piglet, weaner, and finisher periods individually for the sampled batches. We showed that the effect...... of antimicrobial exposure on the levels of AMR genes was complex and unique for each individual gene. Several antimicrobial classes had both negative and positive correlations with the AMR genes. From 10-42% of the variation in AMR gene levels could be explained in the final regression models, indicating...

Antimicrobial Treatments and Efficacy

Science.gov (United States)

To limit exposure to indoor biological contamination a risk-management approach which employs various antimicrobial treatments can effectively control contaminants and reduce exposure. Antimicrobial treatment of biological contaminants, especially mold in buildings, it is often n...

Guanidylation and tail effects in cationic antimicrobial lipopeptoids.

Directory of Open Access Journals (Sweden)

Brandon Findlay

Full Text Available Cationic antimicrobial peptides (CAMPs are attractive scaffolds for the next generation of antimicrobial compounds, due to their broad spectrum of activity against multi-drug resistant bacteria and the reduced fitness of CAMP-insensitive mutants. Unfortunately, they are limited by poor in vivo performance, including ready cleavage by endogenous serum proteases.To explore the potential for peptoid residues to replace well studied CAMP scaffolds we have produced a series of antimicrobial lipopeptoids, with sequences similar to previously reported lipopeptides. The activity of the peptoids was assessed against a panel of clinically relevant and laboratory reference bacteria, and the potential for non-specific binding was determined through hemolytic testing and repeating the antimicrobial testing in the presence of added bovine serum albumin (BSA. The most active peptoids displayed good to moderate activity against most of the gram positive strains tested and moderate to limited activity against the gram negatives. Antimicrobial activity was positively correlated with toxicity towards eukaryotic cells, but was almost completely eliminated by adding BSA.The lipopeptoids had similar activities to the previously reported lipopeptides, confirming their potential to act as replacement, proteolytically stable scaffolds for CAMPs.

Effect of Coating Parameters of the Buffer Layer on the Shape Ratio of TRISO-Coated Particles

International Nuclear Information System (INIS)

KIm, Weon Ju; Park, Jong Hoon; Park, Ji Yeon; Lee, Young Woo; Chang, Jong Hwa

2005-01-01

Fuel for high temperature gas-cooled reactors (HTGR's) consists of TRISO-coated particles. Fluidized bed chemical vapor deposition (FBCVD) has been applied to fabricate the TRISO-coated fuel particles. The TRISO particles consist of UO 2 microspheres coated with layers of porous pyrolytic carbon (PyC), inner dense PyC (IPyC), SiC, and outer dense PyC (OPyC). The porous PyC coating layer, called the buffer layer, attenuates fission recoils and provides void volume for gaseous fission products and carbon monoxide. The buffer layer, which has the highest coating rate among the coating layers, shows the largest variation of the coating thickness within a particle and a batch. This could be the most plausible source of an asphericity in the TRISO particles. The aspherical particles are expected to have an inferior fuel performance. Miller et al. have predicted that a larger stress is developed within the coating layers and thus the failure probability increases in the particles with high aspect ratios. Therefore, the shape of the TRISO-coated particles should be controlled properly and has been one of the important inspection items for the quality control of the fabrication process. In this paper, we investigated the effect of coating parameters of the buffer layer on the shape of the TRISO particles. The flow rate of coating gas and the coating temperature were varied to control the buffer layer. The asphericity of the TRISO-coated particles was evaluated for the various coating conditions of the buffer layer, but at constant coating parameters for the IPyC/SiC/OPyC layers

Effect of Layer-Graded Bond Coats on Edge Stress Concentration and Oxidation Behavior of Thermal Barrier Coatings

Science.gov (United States)

Zhu, Dongming; Ghosn, Louis J.; Miller, Robert A.

1998-01-01

Thermal barrier coating (TBC) durability is closely related to design, processing and microstructure of the coating Z, tn systems. Two important issues that must be considered during the design of a thermal barrier coating are thermal expansion and modulus mismatch between the substrate and the ceramic layer, and substrate oxidation. In many cases, both of these issues may be best addressed through the selection of an appropriate bond coat system. In this study, a low thermal expansion and layer-graded bond coat system, that consists of plasma-sprayed FeCoNiCrAl and FeCrAlY coatings, and a high velocity oxyfuel (HVOF) sprayed FeCrAlY coating, is developed to minimize the thermal stresses and provide oxidation resistance. The thermal expansion and oxidation behavior of the coating system are also characterized, and the strain isolation effect of the bond coat system is analyzed using the finite element method (FEM). Experiments and finite element results show that the layer-graded bond coat system possesses lower interfacial stresses. better strain isolation and excellent oxidation resistance. thus significantly improving the coating performance and durability.

Photocatalytic and antimicrobial Ag/ZnO nanocomposites for functionalization of textile fabrics

Energy Technology Data Exchange (ETDEWEB)

Ibănescu, Mariana [Centre of Nanostructures and Functional Materials-CNMF, Faculty of Materials and Environment Engineering, “Dunărea de Jos” University of Galaţi, 111 Domnească Street, 800201 Galaţi (Romania); Muşat, Viorica, E-mail: viorica.musat@ugal.ro [Centre of Nanostructures and Functional Materials-CNMF, Faculty of Materials and Environment Engineering, “Dunărea de Jos” University of Galaţi, 111 Domnească Street, 800201 Galaţi (Romania); Textor, Torsten [Deutsches Textilforschungszentrum Nord-West gGmbH, DTNW, Adlerstr. 1, 47798 Krefeld (Germany); CENIDE, Center for Nanointegration Duisburg-Essen (Germany); Badilita, Viorel [National R and D Institute for Non-ferrous and Rare Metals Nanostructured Materials Laboratory, Ilfov (Romania); Mahltig, Boris [Niederrhein University of Applied Sciences, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany)

2014-10-15

Highlights: • Higher silver doping smaller nanoparticles size and weaker agglomeration. • Higher silver concentration higher optical absorbance and band gap energy. • Small amouts of silver have considerably increased the antimicobial activity. • The photocatalytic activity is consistent with the increase of antimicrobial activity. - Abstract: The utilization of ZnO nanoparticles with photocatalytic and antimicrobial activity for textile treatment has received much attention in recent years. Since silver is a well-known but more expensive antibacterial material, it is of interest to study the extent to which a small amount of silver increases the photocatalytic and antimicrobial activity of the less expensive zinc oxide nanoparticles. This paper reports on the preparation of Ag/ZnO composite nanoparticles by reducing silver on the surface of commercial ZnO nanoparticles dispersed in isopropanol. Crystalline structure, particle size and band gap energy of as-prepared composite nanoparticles were investigated by X-ray diffraction and UV–Vis absorption measurements. Long term stable sols of ZnO and Ag/ZnO nanoparticles were prepared and applied as liquid coating agent for textile treatment, in combination with inorganic–organic hybrid polymer binder sols prepared from the precursors 3-glycidyloxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS). The coating process was carried out on cotton fabrics and cotton/polyester blended fabrics using the pad–dry–cure method. The photocatalytic activity of the nanoparticles, as prepared or applied on textile fabrics, was studied through the degradation of the dye methylene blue (MB) in water under the UV irradiation. The antimicrobial activity of the nanoparticles applied on textile fabrics, was tested against the Gram-negative bacterium Escherichia coli and Gram-positive Micrococcus luteus.

Photocatalytic and antimicrobial Ag/ZnO nanocomposites for functionalization of textile fabrics

International Nuclear Information System (INIS)

Ibănescu, Mariana; Muşat, Viorica; Textor, Torsten; Badilita, Viorel; Mahltig, Boris

2014-01-01

Highlights: • Higher silver doping smaller nanoparticles size and weaker agglomeration. • Higher silver concentration higher optical absorbance and band gap energy. • Small amouts of silver have considerably increased the antimicobial activity. • The photocatalytic activity is consistent with the increase of antimicrobial activity. - Abstract: The utilization of ZnO nanoparticles with photocatalytic and antimicrobial activity for textile treatment has received much attention in recent years. Since silver is a well-known but more expensive antibacterial material, it is of interest to study the extent to which a small amount of silver increases the photocatalytic and antimicrobial activity of the less expensive zinc oxide nanoparticles. This paper reports on the preparation of Ag/ZnO composite nanoparticles by reducing silver on the surface of commercial ZnO nanoparticles dispersed in isopropanol. Crystalline structure, particle size and band gap energy of as-prepared composite nanoparticles were investigated by X-ray diffraction and UV–Vis absorption measurements. Long term stable sols of ZnO and Ag/ZnO nanoparticles were prepared and applied as liquid coating agent for textile treatment, in combination with inorganic–organic hybrid polymer binder sols prepared from the precursors 3-glycidyloxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS). The coating process was carried out on cotton fabrics and cotton/polyester blended fabrics using the pad–dry–cure method. The photocatalytic activity of the nanoparticles, as prepared or applied on textile fabrics, was studied through the degradation of the dye methylene blue (MB) in water under the UV irradiation. The antimicrobial activity of the nanoparticles applied on textile fabrics, was tested against the Gram-negative bacterium Escherichia coli and Gram-positive Micrococcus luteus

In vitro and in vivo antimicrobial activities of seeds of Caesalpinia bonduc (Lin.) Roxb.

Science.gov (United States)

Arif, Tasleem; Mandal, T K; Kumar, Naresh; Bhosale, J D; Hole, Archana; Sharma, G L; Padhi, M M; Lavekar, G S; Dabur, Rajesh

2009-05-04

Caesalpinia bonduc (Lin.) Roxb. is a known drug in Ayurveda to treat various diseases specifically tumors, cysts and cystic fibrosis (CF). The aim of this study was to assess in vitro as well as in vivo antimicrobial activity of Caesalpinia bonduc seeds. The in vitro antimicrobial activities of seed coat and seed kernel extracts were investigated by microbroth dilution assay. In vivo activities of hydro-alcoholic extracts were investigated in rat models of chronic Pseudomonas aeruginosa pneumonia mimicking that in patients with cystic fibrosis. Various extracts of plant seeds exhibited in vitro antimicrobial activities in a range of 22-350 microg/ml. The extracts also showed activity against methicillin resistant (MR) Staphylococcus aureus and ampicillin resistant (AR) Pseudomonas aeruginosa as in the sensitive strains. In rat model of chronic Pseudomonas aeruginosa pneumonia, hydro-alcoholic extracts of Caesalpinia bonduc seed kernel (CBSK) and Caesalpinia bonduc seed coat (CBSC) were injected subcutaneously in the test groups of animals. The control groups were treated with cortisone and saline. Two weeks after challenge with Pseudomonas aeruginosa, the CBSK treated animals showed a significant bacterial clearance from the lungs (PCaesalpinia bonduc may have the potential to be promising natural medicine, with other forms of treatments, for CF patients with chronic Pseudomonas aeruginosa lung infections.

Antimicrobial effect of garlic (Allium sativum).

Science.gov (United States)

Goncagul, Gulsen; Ayaz, Erol

2010-01-01

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

Effect of protective coating on microhardness of a new glass ionomer cement: Nanofilled coating versus unfilled resin

OpenAIRE

Faraji, Foad; Heshmat, Haleh; Banava, Sepideh

2017-01-01

Background and Objectives: EQUIATM is a new gastrointestinal (GI) system with high compressive strength, surface microhardness (MH), and fluoride release potential. This in vitro study aimed to assess the effect of aging and type of protective coating on the MH of EQUIATM GI cement. Materials and Methods: A total of 30 disc-shaped specimens measuring 9 mm in diameter and 2 mm in thickness were fabricated of EQUIATM GI and divided into three groups of G-Coat nanofilled coating (a), no coating ...

Therapeutic drug monitoring of antimicrobials

Science.gov (United States)

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

2012-01-01

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

Effect of potassium sorbate on antimicrobial and physical properties of starch-clay nanocomposite films.

Science.gov (United States)

Barzegar, Hassan; Azizi, Mohammad Hossein; Barzegar, Mohsen; Hamidi-Esfahani, Zohreh

2014-09-22

Using fresh foods which undergo the least processing operations developed widely in recent years. Active packaging is a novel method for preserving these products. Active starch-clay nanocomposite films which contained potassium sorbate (PS) at a level of 0, 5, 7.5 and 10 g PS/100 g starch were produced and their physical, mechanical and antimicrobial properties were evaluated. In order to evaluate antimicrobial properties of films Aspergillus niger was used. The results showed that 5% of the PS did not produce antimicrobial property in the film, but by increasing the content of the additive in film formulation, antimicrobial effect increased. PS increased water permeability and elongation at break of the films, but decreased tensile strength. The rate of PS migration into the semi-solid medium in starch-nanocomposites was lower than starch films. This shows that nanocomposite films could retain their antimicrobial property for longer time. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of cassava starch-based edible coating incorporated with lemongrass essential oil on the quality of papaya MJ9

Science.gov (United States)

Praseptiangga, D.; Utami, R.; Khasanah, L. U.; Evirananda, I. P.; Kawiji

2017-02-01

Edible films and coatings have emerged as an alternative packaging in food applications and have received much attention due to their advantages. The incorporation of essential oils in film matrices to give antimicrobial properties had been observed recently, and could be used as promising preservation technology. In this study, cassava starch-based edible coating incorporated with lemongrass essential oil (1%) was applied by spraying and dipping methods to preserve papaya MJ9 during storage at room temperature. The quality of papaya MJ9 was analyzed based on its physicochemical and microbiological properties. The addition of lemongrass essential oil (1%) significantly inhibited the microbial growth on papaya MJ9 by reducing the value of total yeast and mold as compared to the control. This study also showed that for parameters of weight loss, total soluble solid, vitamin C, and total titratable acid, papaya MJ9 with cassava starch-based edible coating incorporated with lemongrass essential oil (1%) had the lower values than control, however, they had the higher value than control on firmness parameter. These results indicate that cassava starch-based edible coating incorporated with lemongrass essential oil (1%) can be used as an alternative preservation for papaya MJ9.

Antimicrobial effects of helix D-derived peptides of human antithrombin III.

Science.gov (United States)

Papareddy, Praveen; Kalle, Martina; Bhongir, Ravi K V; Mörgelin, Matthias; Malmsten, Martin; Schmidtchen, Artur

2014-10-24

Antithrombin III (ATIII) is a key antiproteinase involved in blood coagulation. Previous investigations have shown that ATIII is degraded by Staphylococcus aureus V8 protease, leading to release of heparin binding fragments derived from its D helix. As heparin binding and antimicrobial activity of peptides frequently overlap, we here set out to explore possible antibacterial effects of intact and degraded ATIII. In contrast to intact ATIII, the results showed that extensive degradation of the molecule yielded fragments with antimicrobial activity. Correspondingly, the heparin-binding, helix D-derived, peptide FFFAKLNCRLYRKANKSSKLV (FFF21) of human ATIII, was found to be antimicrobial against particularly the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Fluorescence microscopy and electron microscopy studies demonstrated that FFF21 binds to and permeabilizes bacterial membranes. Analogously, FFF21 was found to induce membrane leakage of model anionic liposomes. In vivo, FFF21 significantly reduced P. aeruginosa infection in mice. Additionally, FFF21 displayed anti-endotoxic effects in vitro. Taken together, our results suggest novel roles for ATIII-derived peptide fragments in host defense. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

[Antimicrobial effect of various calcium hydroxide on Porphyromonas endodontalis in vitro].

Science.gov (United States)

Du, Ting-ting; Qiu, Li-hong; Jia, Ge; Yang, Di; Guo, Yan

2012-04-01

To compare the antimicrobial activity of Endocal, calcium hydroxide paste, Calxyl, Vitapex on Porphyromonas endodontalis(P.e). (1) The antimicrobial activity of different calcium hydroxide on P.e was examined at different exposure times by dynamic nephelometry. (2) 85 freshly extracted single-rooted human teeth were selected and cut at the amelocemental junction. All roots were randomly divided into five groups. The bacteria were incubated in each canal and were sampled and counted before and after enveloping five kinds of intercanal medicine seeded. Student's t test, One-way ANOVA were used with SPSS11.0 software package for statistical analysis. The bacteria from each group were reduced significantly after intracanal medication (P<0.05). The antibacterial efficacy of Endocal and calcium hydroxide paste were superior to others under dynamic nephelometry test (P<0.05). Endocal, calcium hydroxide paste, Calxyl, Vitapex had strong inhibitory effect on P.e from infected root canals, and the rate of bacteria clearance was 95%. The antimicrobial activity of Endocal was significantly greater than others (P<0.05). Endocal, calcium hydroxide paste, Calxyl and Vitapex were effective for intercanal disinfection. The antibacterial activity of Endocal is greater than Vitapex.

Amphiphilic Peptide Interactions with Complex Biological Membranes : Effect of peptide properties on antimicrobial and anti-inflammatory effects

OpenAIRE

Singh, Shalini

2016-01-01

With increasing problem of resistance development in bacteria against conventional antibiotics, as well as problems associated with diseases either triggered or enhanced by infection, there is an urgent need to identify new types of effective therapeutics for the treatment of infectious diseases and its consequences. Antimicrobial and anti-inflammatory peptides have attracted considerable interest as potential new antibiotics in this context. While antimicrobial function of such peptides is b...

The effect of heat treatment on the antimicrobial properties of honey

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Cuilan eChen

2012-07-01

Full Text Available There is increasing interest in the antimicrobial properties of honey. In most honey samples, antimicrobial activity is due to the generation of hydrogen peroxide (H2O2 by the bee-derived enzyme glucose oxidase, however the amount of H2O2 produced can vary greatly among samples. In addition, honey is a complex product, and other components may contribute to or modulate this activity, which may be further affected by processing procedures used in large-scale commercial production. In this study we examined honey derived from three native Australian floral sources that had previously been associated with H2O2-dependent activity: spotted gum (Eucalyptus maculata, red stringybark (Eucalyptus macrorrhyncha and yellowbox (Eucalyptus melliodora. Antimicrobial activity was measured using standardized assays against the bacterial pathogen Staphylococcus aureus and the fungal pathogen Candida albicans. Antibacterial activity was only seen in four of the six red stringybark samples and ranged from 12-21.1% phenol equivalence. No antibacterial activity was detected in the spotted gum or yellowbox samples. Antifungal activity ranged from MIC values of 19-38.3 % (w/v, and although all samples were significantly more active than an osmotically equivalent sugar solution, most had relatively low activity. All honey samples were provided unprocessed and underwent standard heating and filtration procedures (45˚C for 8 hours followed by filtration with a 100 µm filter, allowing the effects of commercial heating and filtration methods on antimicrobial activity and H2O2 levels to be assessed. Average antibacterial and antifungal activities decreased, but while processing was usually detrimental, occasionally the reverse was seen and antimicrobial activity increased. Significant activity was eliminated from all samples by the addition of catalase, indicating that H2O2 was chiefly responsible for their antimicrobial action, and H2O2 production was measured in the

Bacterial Biofilm Characterization and Microscopic Evaluation of the Antibacterial Properties of a Photocatalytic Coating Protecting Building Material

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Thomas Verdier

2018-03-01

Full Text Available Use of photocatalytic paint-like coatings may be a way to protect building materials from microbial colonization. Numerous studies have shown the antimicrobial efficiency of TiO 2 photocatalysis on various microorganisms. However, few have focused on easy-to-apply solutions and on photocatalysis under low irradiance. This paper focuses on (a the antibacterial properties of a semi-transparent coating formulated using TiO 2 particles and (b the microscopic investigations of bacterial biofilm development on TiO 2 -coated building materials under accelerated growth conditions. Results showed significant antibacterial activity after few hours of testing. The efficiency seemed limited by the confinement of the TiO 2 particles inside the coating binder. However, a pre-irradiation with UV light can improve efficiency. In addition, a significant effect against the formation of a bacterial biofilm was also observed. The epifluorescence approach, in which fluorescence is produced by reflect rather than transmitted light, could be applied in further studies of microbial growth on coatings and building materials.

Effect of coating thickness on interfacial shear behavior of zirconia-coated sapphire fibers in a polycrystalline alumina matrix

International Nuclear Information System (INIS)

Hellmann, J.R.; Chou, Y.S.

1995-01-01

The effect of zirconia (ZrO 2 ) interfacial coatings on the interfacial shear behavior in sapphire reinforced alumina was examined in this study. Zirconia coatings of thicknesses ranging from 0.15 to 1.45 μm were applied to single crystal sapphire (Saphikon) fibers using a particulate loaded sol dipping technique. After calcining at 1,100 C in air, the coated fibers were incorporated into a polycrystalline alumina matrix via hot pressing. Interfacial shear strength and sliding behavior of the coated fibers was examined using thin-slice indentation fiber pushout and pushback techniques. In all cases, debonding and sliding occurred at the interface between the fibers and the coating. The coatings exhibited a dense microstructure and led to a higher interfacial shear strength (> 240 MPa) and interfacial sliding stress (> 75 MPa) relative to previous studies on the effect of a porous interphase on interfacial properties. The interfacial shear strength decreased with increasing fiber coating thickness (from 389 ± 59 to 241 ± 43 MPa for 0.15 to 1.45 microm thick coatings, respectively). Sliding behavior exhibited load modulation with increasing displacement during fiber sliding which is characteristic of fiber roughness-induced stick-slip. The high interfacial shear strengths and sliding stresses measured in this study, as well as the potentially strength degrading surface reconstruction observed on the coated fibers after hot pressing and heat treatment, indicate that dense zirconia coatings are not suitable candidates for optimizing composite toughness and strength in the sapphire fiber reinforced alumina system

Effect of Surface Coatings on Cylinders Exposed to Underwater Shock

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Y.W. Kwon

1994-01-01

Full Text Available The response of a coated cylinder (metallic cylinder coated with a rubber material subjected to an underwater explosion is analyzed numerically. The dynamic response of the coated cylinder appears to be adversely affected when impacted by an underwater shock wave under certain conditions of geometry and material properties of the coating. When adversely affected, significant deviations in values of axial stress, hoop stress, and strain are observed. The coated cylinder exhibits a larger deformation and higher internal energy in the metallic material. Rubber coatings appeared to inhibit energy dissipation from the metallic material to the surrounding water medium. A parametric study of various coatings was performed on both aluminum and steel cylinders. The adverse effect of the coating decreased when the stiffness of the rubber layer increased, indicating the existence of a threshold value. The results of this study indicate that the stiffness of the coating is a critical factor to the shock hardening of the coated cylinder.

Automatic day-2 intervention by a multidisciplinary Antimicrobial Stewardship-Team leads to multiple positive effects

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Jan-Willem H Dik

2015-06-01

Full Text Available Background: Antimicrobial resistance rates are increasing. This is, among others, caused by incorrect or inappropriate use of antimicrobials. To target this, a multidisciplinary Antimicrobial Stewardship-Team (A-Team was implemented at the University Medical Center Groningen on a urology ward. Goal of this study is to evaluate the clinical effects of the case-audits done by this team, looking at length of stay (LOS and antimicrobial use.Methods: Automatic e-mail alerts were sent after 48 hours of consecutive antimicrobial use triggering the case-audits, consisting of an A-Team member visiting the ward, discussing the patient’s therapy with the bed-side physician and together deciding on further treatment based on available diagnostics and guidelines. Clinical effects of the audits were evaluated through an Interrupted Time Series analysis and a retrospective historic cohort. Results: A significant systemic reduction of antimicrobial consumption for all patients on the ward, both with and without case-audits was observed. Furthermore, LOS for patients with case-audits who were admitted primarily due to infections decreased to 6.20 days (95% CI: 5.59-6.81 compared to the historic cohort (7.57 days; 95% CI: 6.92-8.21 (p=0.012. Antimicrobial consumption decreased for these patients from 8.17 DDD/patient (95% CI: 7.10-9.24 to 5.93 DDD/patient (95% CI: 5.02-6.83 (p=0.008. For patients with severe underlying diseases (e.g. cancer these outcome measures remained unchanged.Conclusions: The evaluation showed a considerable positive impact. Antibiotic use of the whole ward was reduced, transcending the intervened patients. Furthermore, LOS and mean antimicrobial consumption for a subgroup was reduced, thereby improving patient care and potentially lowering resistance rates.

Calcium and Zinc Containing Bactericidal Glass Coatings for Biomedical Metallic Substrates

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Leticia Esteban-Tejeda

2014-07-01

Full Text Available The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3–SiO2–Na2O–ZnO and SiO2–Na2O–Al2O3–CaO–B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log.

Ligand-Doped Copper Oxo-hydroxide Nanoparticles are Effective Antimicrobials

Science.gov (United States)

Bastos, Carlos A. P.; Faria, Nuno; Ivask, Angela; Bondarenko, Olesja M.; Kahru, Anne; Powell, Jonathan

2018-04-01

Bacterial resistance to antimicrobial therapies is an increasing clinical problem. This is as true for topical applications as it is for systemic therapy. Topically, copper ions may be effective and cheap antimicrobials that act through multiple pathways thereby limiting opportunities to bacteria for resistance. However, the chemistry of copper does not lend itself to facile formulations that will readily release copper ions at biologically compatible pHs. Here, we have developed nanoparticulate copper hydroxide adipate tartrate (CHAT) as a cheap, safe, and readily synthesised material that should enable antimicrobial copper ion release in an infected wound environment. First, we synthesised CHAT and showed that this had disperse aquated particle sizes of 2-5 nm and a mean zeta potential of - 40 mV. Next, when diluted into bacterial medium, CHAT demonstrated similar efficacy to copper chloride against Escherichia coli and Staphylococcus aureus, with dose-dependent activity occurring mostly around 12.5-50 mg/L of copper. Indeed, at these levels, CHAT very rapidly dissolved and, as confirmed by a bacterial copper biosensor, showed identical intracellular loading to copper ions derived from copper chloride. However, when formulated at 250 mg/L in a topically applied matrix, namely hydroxyethyl cellulose, the benefit of CHAT over copper chloride was apparent. The former yielded rapid sustained release of copper within the bactericidal range, but the copper chloride, which formed insoluble precipitates at such concentration and pH, achieved a maximum release of 10 ± 7 mg/L copper by 24 h. We provide a practical formulation for topical copper-based antimicrobial therapy. Further studies, especially in vivo, are merited.

Internal homogenization: effective permittivity of a coated sphere.

Science.gov (United States)

Chettiar, Uday K; Engheta, Nader

2012-10-08

The concept of internal homogenization is introduced as a complementary approach to the conventional homogenization schemes, which could be termed as external homogenization. The theory for the internal homogenization of the permittivity of subwavelength coated spheres is presented. The effective permittivity derived from the internal homogenization of coreshells is discussed for plasmonic and dielectric constituent materials. The effective model provided by the homogenization is a useful design tool in constructing coated particles with desired resonant properties.

CHEMICAL COMPOSITION, ANTIMICROBIAL AND ANTIOXYDANT ...

African Journals Online (AJOL)

VOUNDI

2016-04-20

Apr 20, 2016 ... antimicrobial activities of some spices' essential oils on ... antimicrobial effect of their essential oils on some food pathogenic bacteria, namely, Staphylococcus aureus ...... by Origanum compactum essential oil. J. Appl.

Influence of Food Characteristics and Food Additives on the Antimicrobial Effect of Garlic and Oregano Essential Oils.

Science.gov (United States)

García-Díez, Juan; Alheiro, Joana; Pinto, Ana Luisa; Soares, Luciana; Falco, Virgilio; Fraqueza, Maria João; Patarata, Luis

2017-06-10

Utilization of essential oils (EOs) as antimicrobial agents against foodborne disease has gained importance, for their use as natural preservatives. Since potential interactions between EOs and food characteristics may affect their antimicrobial properties, the present work studies the influence of fat, protein, pH, a w and food additives on the antimicrobial effect of oregano and garlic EOs against Salmonella spp. and Listeria monocytogenes. Results showed that protein, pH, a w , presence of beef extract, sodium lactate and nitrates did not influence their antimicrobial effect. In contrast, the presence of pork fat had a negative effect against both EOs associated with their dilution of the lipid content. The addition of food phosphates also exerts a negative effect against EOs probably associated with their emulsification properties as observed with the addition of fat. The results may help the food industry to select more appropriate challenges to guarantee the food safety of foodstuffs.

Nonadhesive, silica nanoparticles-based brush-coated contact lens cases--compromising between ease of cleaning and microbial transmission to contact lenses.

Science.gov (United States)

Qu, Wenwen; Hooymans, Johanna M M; Qiu, Jun; de-Bont, Nik; Gelling, Onko-Jan; van der Mei, Henny C; Busscher, Henk J

2013-05-01

Surface properties of lens cases are determinant for their cleanability and for microbial transmission from lens cases to contact lenses (CLs). PEG-polymer-brush-coatings are known to decrease microbial adhesion more than other surface-coatings. Here, we applied a robust, silica nanoparticles-based brush-coating to polypropylene cases to evaluate their ease of cleaning and probability of bacterial transmission to CLs. Adhesion forces of nine bacterial strains (Pseudomonas, Staphylococci, and Serratia) to rigid CLs, polypropylene, and silica nanoparticles-based brush-coated polypropylene were measured using atomic-force-microscopy and subjected to Weibull analyses to yield bacterial transmission probabilities. Biofilms of each strain were grown in coated and uncoated cases and rinsed with a NaCl or antimicrobial lens care solution. Residual, viable organisms were quantified. Bacterial adhesion forces of all strains were significantly, up to tenfold smaller on brush-coated than on uncoated polypropylene. This yielded, higher transmission probabilities to a CL, but mild-rinsing yielded 10-100 fold higher removal of bacteria from brush-coated than from polypropylene cases. Moreover, due to weak adhesion forces, bacteria on brush-coated cases were two-to-three fold more susceptible to an antimicrobial lens care solution than on polypropylene cases. Therewith, the design of lens case surfaces is a compromise between ease of cleaning and transmission probability to CLs. Copyright © 2013 Wiley Periodicals, Inc.

Effect of bond coat and preheat on the microstructure, hardness, and porosity of flame sprayed tungsten carbide coatings

Science.gov (United States)

Winarto, Winarto; Sofyan, Nofrijon; Rooscote, Didi

2017-06-01

Thermally sprayed coatings are used to improve the surface properties of tool steel materials. Bond coatings are commonly used as intermediate layers deposited on steel substrates (i.e. H13 tool steel) before the top coat is applied in order to enhance a number of critical performance criteria including adhesion of a barrier coating, limiting atomic migration of the base metal, and corrosion resistance. This paper presents the experimental results regarding the effect of nickel bond coat and preheats temperatures (i.e. 200°C, 300°C and 400°C) on microstructure, hardness, and porosity of tungsten carbide coatings sprayed by flame thermal coating. Micro-hardness, porosity and microstructure of tungsten carbide coatings are evaluated by using micro-hardness testing, optical microscopy, scanning electron microscopy, and X-ray diffraction. The results show that nickel bond coatings reduce the susceptibility of micro crack formation at the bonding area interfaces. The percentage of porosity level on the tungsten carbide coatings with nickel bond coat decreases from 5.36 % to 2.78% with the increase of preheat temperature of the steel substrate of H13 from 200°C to 400°C. The optimum hardness of tungsten carbide coatings is 1717 HVN in average resulted from the preheat temperature of 300°C.

Antimicrobial stewardship: attempting to preserve a strategic resource

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Trevor Van Schooneveld, Md

2011-07-01

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

Recent innovations in the area of edible films and coatings.

Science.gov (United States)

Maftoonazad, Neda; Badii, Fojan; Shahamirian, Maryam

2013-12-01

Edible films/coatings have been considered as one of the potential technologies that can be used to increase the storability of foods and to improve the existent packaging technology, helping to ensure the microbial safety and the preservation of food from the influence of external factors. Innovations constantly appear in food packaging, always aiming at creating a more efficient quality preservation system while improving foods' attractiveness and marketability. The utilization of renewable sources for packaging materials, such as hydrocolloids and lipids from biological origin, is one the main trends of the industry. These films should have acceptable sensory characteristics, appropriate barrier properties (CO2, O2, water, oil), microbial, biochemical and physicochemical stability, they should be safe, and produced by simple technology in low cost. Also they can act as effective carrier for antioxidant, flavor, color and nutritional or anti-microbial additives. Nowadays, a great discussion exists about the potential applications of edible films/coatings on food products. The general trend is to find the correct combination between the food product and the edible film/coating, which will ensure the success of the technology.

Application of lemon peel essential oil with edible coating agent to prolong shelf life of tofu and strawberry

Science.gov (United States)

Rahmawati, Della; Chandra, Mega; Santoso, Stefanus; Puteri, Maria Gunawan

2017-01-01

The essential oil of sweet orange, lemon, and key lime peel were analyzed for their antimicrobial activity. The antimicrobial activity of each citrus essential oil with different concentration was assessed using broth macro-dilution against Bacillus sp, Eschericia coli, Rhizopus stolonifer, and Botrytis sp which represented specific spoilage microorganism in tofu and fresh strawberry. Among all the citrus peel essential oils tested, lemon peel essential oil with 0.6% concentration showed significant activity as an antimicrobial agent against Escherichia coli and Bacillus sp. In other hand 1% of lemon peel essential oil is also considered to be the best concentration of inhibiting the Rhizopus Stolonifer and Botrytis sp. Lemon peel essential oil which has the highest antimicrobial activity was combined with two different kind of edible coating agents (cassava starch and sodium alginate) and was applied in both tofu and strawberry to observe whether it had possibility to decrease the degradation rate of tofu and strawberry. The addition of 0.6% and 1% lemon peel essential oil with each of edible coating agents was significantly able to reduce the degradation of tofu and fresh strawberry.

Biocompatible Silver-containing a-C:H and a-C coatings: AComparative Study

Energy Technology Data Exchange (ETDEWEB)

Endrino, Jose Luis; Allen, Matthew; Escobar Galindo, Ramon; Zhang, Hanshen; Anders, Andre; Albella, Jose Maria

2007-04-01

Hydrogenated diamond-like-carbon (a-C:H) and hydrogen-free amorphous carbon (a-C) coatings are known to be biocompatible and have good chemical inertness. For this reason, both of these materials are strong candidates to be used as a matrix that embeds metallic elements with antimicrobial effect. In this comparative study, we have incorporated silver into diamond-like carbon (DLC) coatings by plasma based ion implantation and deposition (PBII&D) using methane (CH4) plasma and simultaneously depositing Ag from a pulsed cathodic arc source. In addition, we have grown amorphous carbon - silver composite coatings using a dual-cathode pulsed filtered cathodic-arc (FCA) source. The silver atomic content of the deposited samples was analyzed using glow discharge optical spectroscopy (GDOES). In both cases, the arc pulse frequency of the silver cathode was adjusted in order to obtain samples with approximately 5 at.% of Ag. Surface hardness of the deposited films was analyzed using the nanoindentation technique. Cell viability for both a-C:H/Ag and a-C:/Ag samples deposited on 24-well tissue culture plates has been evaluated.

Effect of coating parameters on the microstructure of cerium oxide conversion coatings

Energy Technology Data Exchange (ETDEWEB)

Johnson, Benedict Y.; Edington, Joe; O' Keefe, Matthew J

2003-11-25

The microstructure and morphology of cerium oxide conversion coatings prepared under different deposition conditions were characterized by transmission electron microscopy (TEM). The coatings were formed by a spontaneous reaction between a water-based solution containing CeCl{sub 3} and aluminum alloy 7075-T6 substrates. Microstructural characterization was performed to determine the crystallinity of the coatings and to obtain a better understanding of the deposition parameters on coating microstructure. The results of TEM imaging and electron diffraction analysis indicated that the as-deposited coating was composed of nanocrystalline particles of a previously unreported cerium compound. The particles of the coatings produced using glycerol as an additive were found to be much finer than those of the coatings prepared in the absence of glycerol. This indicates that glycerol may act as a grain refiner and/or growth inhibitor during coating deposition. After deposition, the coated panels were treated for 5 min in a phosphate sealing solution. The sealing treatment converted the as-deposited coating into hydrated cerium phosphate. Panels coated from solutions containing no glycerol followed by phosphate sealing performed poorly in salt fog tests. With glycerol addition, the corrosion resistance of the coatings that were phosphate sealed improved considerably, achieving an average passing rate of 85%.

Antimicrobial activity Study of triclosan-loaded WBPU on Proteus mirabilis in vitro.

Science.gov (United States)

Tian, Ye; Jian, Zhongyu; Wang, Jianzhong; He, Wei; Liu, Qinyu; Wang, Kunjie; Li, Hong; Tan, Hong

2017-04-01

To evaluate the antimicrobial activity study of triclosan-loaded waterborne polyurethanes (WBPU) on Proteus mirabilis in vitro. Inhibition zone assays on petri plates with triclosan-loaded WBPU samples were used to test its antimicrobial activity on Proteus mirabilis. Models of the catheterized bladder supplied with artificial urine infected with Proteus mirabilis were employed to confirm the antimicrobial activity of triclosan-loaded WBPU. Bacteria colony counting, pH of the residual urine at each time point and catheter blockage time were recorded. Confocal laser scanning microscopy, scanning electron microscopy and encrustation deposits dry weighing were used for evaluating the biofilm formation. Inhibition zones formed in the triclosan-loaded WBPU groups in a dose-response manner (the radius for samples with 1, 0.1 and 0.01 mg triclosan were 9.93 ± 1.08, 6.07 ± 0.54 and 2.47 ± 0.25 mm, P Proteus mirabilis biofilm formation (33.9 ± 13.9 mg vs. 1.4 ± 1.5 mg, P = 0.016). Triclosan-loaded WBPU significantly inhibited Proteus mirabilis' growth and biofilm formation, indicating the promising antibacterial effects on Proteus mirabilis in vitro. Further efforts are under way that involves coating the material onto the urinary catheters and in vivo studies.

Comparison of the effectiveness of different antimicrobial surface technologies

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Buhl Sebastian

2017-09-01

Full Text Available The risk of infection via microbiologically contaminated surfaces has already been demonstrated by other publications. In this work two different antibacterial surface technologies transition metalloacids (AMiSTec and TiO2/AgNO3 (Health Complete were compared regarding feasibility as well as their advantages and disadvantages. The examination of the antimicrobial activity was assessed according to the JIS Z 2801. We could demonstrate that all of our tested samples showed a strong antimicrobial activity (>log 3 germ reduction in the JIS experiments. Furthermore this strong antibacterial effect could be shown already after <30min incubation and at low light intensity (approx. 300 Lux for the TiO2/AgNO3 samples. Both technologies provide a high potential for an improved infection control for example in a high risk environment like operation rooms or intensive care units.

Synergistic Antimicrobial Effect of Tribulus terrestris and Bitter Almond Extracts

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Hamid Abtahi

2014-12-01

Full Text Available Background: The antimicrobial effects of the extracts of different kinds of plants have been demonstrated in several studies. However, no study has been conducted so far on the synergistic effects of two herbal extracts on their germicidal effects. In this study, in addition to antibacterial effects of the aqueous, methanol or ethanol extracts of Tribulus terrestris and bitter almond on some bacteria, the synergistic effects of the extracts of these two plants were also evaluated. Materials and Methods: In this experimental study, water, methanol and ethanol extracts of seeds were screened against some bacterial strains. Seeds were extracted by percolation method. Aliquots of the extracts at variable concentrations were then incubated with different bacterial strains, and the antimicrobial activities of the extracts from seeds were determined by MIC. Three antibiotics were used as reference compounds for antibacterial activities. Seeds extract inhibited significantly the growth of the tested bacterial strains. Results: The greatest synergistic effect of T. terrestris and bitter almond extracts is detected in methanol and aqueous extracts. Among the bacterial strains tested, Staphylococcus aureus was most susceptibility. Conclusion: The results showed the highest antibacterial effect in the combination of methanol extract of T. terrestris and the aqueous extract of the bitter almond.

Effect of Chitosan Coating Treatments and Calcium Dips on Quality and Shelf-life of Strawberries

International Nuclear Information System (INIS)

Swailam, H.M.

2008-01-01

Strawberries are a highly perishable fruit and storage life may be less than a week. In these investigations strawberries were treated with one of the following treatments: I) 1 % calcium chloride dips (1 % CaCl 2 ), II) 2 % irradiated (150 kGy in the solid state) chitosan (CS) (2 % Irr. CS) and III) with a coating formulation containing 2 % Irr. CS + 1 % CaCl 2 . They were then stored at 6 degree C for up to 24 days. The effectiveness of the different treatments was assessed by evaluating the microbiological, physicochemical and sensory properties of strawberries during the storage period. Results indicated that no sign of strawberries decay were observed in the fruits treated with CS formulation containing 2 % Irr. CS + 1 % CaCl 2 up to 20 days, where 6.1 % wt loss was detected. This treatment slowed the ripening of strawberries as shown by their retention of firmness and delayed changes in their external colour anthocyanin. To a lesser extent titratable acidity and ph were also affected by coatings. This treatment decreased the initial log counts of total aerobic bacteria, mould and yeast, coliform and E. coli. After 20 days of cold storage, the log counts of these micro organisms were lower than the log count of uncoated strawberries. Thus, CS can be used as a natural antimicrobial coating on fresh strawberries to improve microbiological quality and extend shelf-life. CS formulation contains 2 % Irr. CS + 1 % CaCl 2 extended the shelf-life of strawberries to 20 days in cold storage at 6 degree C with acceptable appearance, firmness, flavour and colour, while uncoated strawberries only lasted for 4 days as a result of mould growth and loss of surface appearance

Study of antimicrobial effect of novel Quaternary Ammonium Compounds on bacteria and fungi

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Maryam Sadrnia

2014-10-01

Full Text Available Background: Quarterly Ammonium Compounds (QuAC are the more effective antimicrobial agents in medicine and industry. It needs to produce the new compounds with the wider spectrum and less toxicity, because of microbial resistance. Aim of this study was microbiological Evaluation of the new Quarterly Ammonium Compounds produced by Structural modifications on some bacteria, yeast and fungi. Material and Methods: 16 Quat salts were designed and made in Ethanol or Aceto Nitril. Minimum Inhibitory Concentration (MIC was determined by standard method on Nutrient Broth and Minimal agar culture media for bacteria , Potato Dextrose Agar (PDA for fungi and Nutrient Agar and Saboro Dextrose Agar (SDA for yeasts . Results: Compounds 2,7,8,9,12,13 has the more antimicrobial effect ( minimum of MIC. Furthermore, it was shown that MIC was unrelated to culture compounds. In yeast culture it must to increases the concentration in enriched media. Compounds 9,12 and 13 has the more antibacterial effect as well as antifungal effect. Conclusion: In comparison of structure of produced compounds and results of the study, it was revealed that radical R3 has the most important role in antimicrobial properties of Quats and it could to be substitute any suitable group related to increasing anti microbial effects.

Effect of Gamma Radiation on Chemical Composition and Antimicrobial Activity of Fennel and Geranium Volatile Oils

International Nuclear Information System (INIS)

Abo-Seoud, M. A.; Helal, I. M. M.; Sarhan, M. M.; Galal, A. M. M.

2004-01-01

Essential oils of fennel and geranium were gamma irradiated with doses of 0,10,20,30 and 40 kGy. The studied oils were tested for their antimicrobial activities against some pathogenic microorganisms (Alternaria alternata, Aspergillus niger, A. flavus, Fusarium oxysporium, Trichoderma viride and Pseudomonas citri). Both oils were used in four concentrations of 500, 1000, 2000 and 4000 ppm. The investigated oils showed different inhibition effects against the tested microorganisms. Gamma irradiated oils increased the antimicrobial activity with different magnitudes. Generally, increasing oil concentration increased antimicrobial activity of the used oils and that of 4000 ppm was the most effective one. The essential oils were analyzed by G.C. to evaluate the effect of gamma irradiation on the oil components. (authors)

Antimicrobial Drugs in Fighting against Antimicrobial Resistance

OpenAIRE

Cheng, Guyue; Dai, Menghong; Ahmed, Saeed; Hao, Haihong; Wang, Xu; Yuan, Zonghui

2016-01-01

The outbreak of antimicrobial resistance, together with the lack of newly developed antimicrobial drugs, represents an alarming signal for both human and animal healthcare worldwide. Selection of rational dosage regimens for traditional antimicrobial drugs based on pharmacokinetic/pharmacodynamic principles as well as development of novel antimicrobials targeting new bacterial targets or resistance mechanisms are key approaches in tackling AMR. In addition to the cellular level resistance (i....

Effect of edible co-polymers coatings using γ-irradiation on Hyani date fruit behavior during marketing.

Science.gov (United States)

El-Dein, Asmaa Ezz; Khozemy, Ehab E; Farag, Serag A; Abd El-Hamed, N; Dosoukey, I M

2018-05-24

The present work introduces a preparation of coating fruits film from natural biodegradable materials with evaluation of its efficiency in keeping the quality of fresh date fruits. Triple blend (Tb) which involved PVA, chitosan (Cs) and tannic (TA) acids was studied in preservation of Rutab (Hyani) date. Antimicrobial characters besides decay of fruits during a cold storage were determined. The blend solutions were exposed to the γ-irradiation (5.0 to 20 kGy) before casting or use. The effects of polymer composition and irradiation dose on the mechanical and thermo-mechanical properties were studied. The obtained results showed that γ-irradiation and the addition of tannic acid (TA) increased the mechanical properties of the films and the shelf-life of Rutab (Hyani) date during the marketing period (12 ± 2 °C, 98%, RH) from one week to one month of marketing period for consumers with accepted freshness and quality. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of protective coating on microhardness of a new glass ionomer cement: Nanofilled coating versus unfilled resin.

Science.gov (United States)

Faraji, Foad; Heshmat, Haleh; Banava, Sepideh

2017-01-01

EQUIA TM is a new gastrointestinal (GI) system with high compressive strength, surface microhardness (MH), and fluoride release potential. This in vitro study aimed to assess the effect of aging and type of protective coating on the MH of EQUIA TM GI cement. A total of 30 disc-shaped specimens measuring 9 mm in diameter and 2 mm in thickness were fabricated of EQUIA TM GI and divided into three groups of G-Coat nanofilled coating (a), no coating (b) and margin bond (c). The Vickers MH value of specimens was measured before (baseline) and at 3 and 6 months after water storage. Data were analyzed using repeated measures ANOVA. Group B had significantly higher MH than the other two groups at baseline. Both G-Coat and margin bond increased the surface MH of GI at 3 and 6 months. The MH values of G-Coat and margin bond groups did not significantly increase or decrease between 3 and 6 months. The increase in MH was greater in the G-Coat compared to the margin bond group in the long-term. Clinically, margin bond may be a suitable alternative when G-Coat is not available.

The Effect of Tempering on Strength Properties and Seed Coat ...

African Journals Online (AJOL)

The effect of tempering on seed coat adhesion strength and mechanical strength of sorghum and millet grain kernels was investigated at different tempering durations. Tempering reduced the kernel breaking strength and had significant effect on seed coat adhesion strength. Tempering the grain for 60 minutes at ambient ...

Maillard reaction products as antimicrobial components for packaging films.

Science.gov (United States)

Hauser, Carolin; Müller, Ulla; Sauer, Tanja; Augner, Kerstin; Pischetsrieder, Monika

2014-02-15

Active packaging foils with incorporated antimicrobial agents release the active ingredient during food storage. Maillard reaction products (MRPs) show antimicrobial activity that is at least partially mediated by H2O2. De novo generation of H2O2 by an MRP fraction, extracted from a ribose/lysine Maillard reaction mixture by 85% ethanol, was monitored at three concentrations (1.6, 16.1, and 32.3g/L) and three temperatures (4, 25, and 37 °C) between 0 and 96 h, reaching a maximum of 335 μM H2O2 (32.3g/L, 37 °C, 96 h). The active MRP fraction (16.1g/L) completely inhibited the growth of Escherichia coli for 24h and was therefore incorporated in a polyvinyl acetate-based lacquer and dispersed onto a low-density polyethylene film. The coated film generated about 100 μM H2O2 and resulted in a log-reduction of >5 log-cycles against E. coli. Thus, MRPs can be considered as active ingredients for antimicrobial packaging materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nanocomposited coatings produced by laser-assisted process to prevent silicone hydogels from protein fouling and bacterial contamination

International Nuclear Information System (INIS)

Huang, Guobang; Chen, Yi; Zhang, Jin

2016-01-01

Graphical abstract: Nanocomposited-coating was deposited on silicone hydrogel by using the matrix-assisted pulsed laser evaporation (MAPLE) process. The ZnO–PEG nanocomposited coating reduces over 50% protein absorption on silicone hydrogel, and can inhibit the bacterial growth efficiently. - Highlights: • We developed a nanocomposited coating to prevent silicone hydrogel from biofouling. • Matrix-assisted pulsed laser evaporation can deposit inorganic–organic nanomaterials. • The designed nanocomposited coating reduces protein absorption by over 50%. • The designed nanocomposited coating shows significant antimicrobial efficiency. - Abstract: Zinc oxide (ZnO) nanoparticles incorporating with polyethylene glycol (PEG) were deposited together on the surface of silicone hydrogel through matrix-assisted pulsed laser evaporation (MAPLE). In this process, frozen nanocomposites (ZnO–PEG) in isopropanol were irradiated under a pulsed Nd:YAG laser at 532 nm for 1 h. Our results indicate that the MAPLE process is able to maintain the chemical backbone of polymer and prevent the nanocomposite coating from contamination. The ZnO–PEG nanocomposited coating reduces over 50% protein absorption on silicone hydrogel. The cytotoxicity study shows that the ZnO–PEG nanocomposites deposited on silicone hydrogels do not impose the toxic effect on mouse NIH/3T3 cells. In addition, MAPLE-deposited ZnO–PEG nanocomposites can inhibit the bacterial growth significantly.

Development and characterization of multilayer films of polyaniline, titanium dioxide and CTAB for potential antimicrobial applications

International Nuclear Information System (INIS)

Farias, Emanuel Airton O.; Dionisio, Natália A.; Quelemes, Patrick V.; Leal, Sergio Henrique; Matos, José Milton E.; Filho, Edson C. Silva; Bechtold, Ivan H.; Leite, José Roberto S.A.; Eiras, Carla

2014-01-01

Composites prepared from polyaniline (PANI) and the ceramic technology of titanium dioxide (TiO 2 ) have been proposed, however, the interaction of these materials with greater control of molecular arrangement becomes attractive in order to achieve properties not previously described or yet the optimization of those already reported. Therefore, in this study, thin hybrid films made of polyaniline (PANI), a conductive polymer, and the technological ceramic, titanium dioxide (TiO 2 ), were prepared by the layer-by-layer (LbL) self-assembly technique. The films were characterized by cyclic voltammetry (CV), UV–VIS spectroscopy and atomic force microscopy (AFM). Aiming to improve the dispersion of the ceramic in the polymer matrix, the commercial surfactant, cetyl trimethylammonium bromide (CTAB), was used in the formation of the films. The best condition of deposition was found showing synergic interactions between the conjugated materials. The antibacterial activity of the PANI(TiO 2 )/CTAB films was studied and the obtained results suggest their use as antimicrobial coatings. - Highlights: • Nanocomposite films of PANI and TiO2 prepared by the LbL technique • Ceramic dispersion in PANI improved with CTAB for antimicrobial applications. • Optimized film deposition for synergic interactions of the conjugated materials • Antibacterial activity of the films suggests their use as antimicrobial coatings

Assessing the antimicrobial activity of zinc oxide thin films using disk diffusion and biofilm reactor

International Nuclear Information System (INIS)

Gittard, Shaun D.; Perfect, John R.; Monteiro-Riviere, Nancy A.; Wei Wei; Jin Chunming; Narayan, Roger J.

2009-01-01

The electronic and chemical properties of semiconductor materials may be useful in preventing growth of microorganisms. In this article, in vitro methods for assessing microbial growth on semiconductor materials will be presented. The structural and biological properties of silicon wafers coated with zinc oxide thin films were evaluated using atomic force microscopy, X-ray photoelectron spectroscopy, and MTT viability assay. The antimicrobial properties of zinc oxide thin films were established using disk diffusion and CDC Biofilm Reactor studies. Our results suggest that zinc oxide and other semiconductor materials may play a leading role in providing antimicrobial functionality to the next-generation medical devices

The Effect of Substrate Topography on Coating Cathodic Delamination

DEFF Research Database (Denmark)

Erik Weinell, Claus; Sørensen, Per A.; Kiil, Søren

2011-01-01

This article describes the effect of steel substrate topography on coating cathodic delamination. The study showed that the surface preparation can be used to control and minimize the rate of cathodic delamination. The coating should have maximum wetting properties so that substrates with high...

Effect of substrates on tribological properties of diamond-like carbon coating

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Renhui ZHANG

2017-06-01

Full Text Available In order to well investigate the effect of different substrates on the friction and wear of diamond-like carbon (DLC coating, the DLC coatings are deposited on substrates like the high-speed steel (HSS, SiC and 304 stainless steel by using plasma enhanced chemical vapor deposition method. The diamond-like carbon is prepared. The microstructure of the coatings is characterized using SEM, TEM and Raman. The SEM results exhibit that the total thickness of the coatings is about 6.5 μm, and there's apparent interfaces between layers. The TEM results imply that the coatings have an amorphous structure. Raman spectrum exhibits that G and D peaks are observed, which implies that the deposition coatings are diamond-like carbon coating. The results of tribological tests show that the substrates have a significant effect on the friction and wear of the coating. For different substrates, the transfer film is found on the steel counterpart surface, the wear track of the HSS has a lowest width, and the DLC coating that deposited on HSS exhibits the lowest wear and low friction coefficient (about 0.1.The microstructure of different substrates wear track surfaces is analyzed by using Raman spectrum, and the lowest wear of the HSS is attributed to the lower degree of the graphitization. The research provides reference for preparing the DLC coating with excellent tribological properties.

Short, multiple-stranded β-hairpin peptides have antimicrobial potency with high selectivity and salt resistance.

Science.gov (United States)

Chou, Shuli; Shao, Changxuan; Wang, Jiajun; Shan, Anshan; Xu, Lin; Dong, Na; Li, Zhongyu

2016-01-01

The β-hairpin structure has been proposed to exhibit potent antimicrobial properties with low cytotoxicity, thus, multiple β-hairpin structures have been proved to be highly stable in structures containing tightly packed hydrophobic cores. The aim of this study was to develop peptide-based synthetic strategies for generating short, but effective AMPs as inexpensive antimicrobial agents. Multiple-stranded β-hairpin peptides with the same β-hairpin unit, (WRXxRW)n where n=1, 2, 3, or 4 and Xx represent the turn sequence, were synthesized, and their potential as antimicrobial agents was evaluated. Owning to the tightly packed hydrophobic core and paired Trp of this multiple-stranded β-hairpin structure, all the 12-residues peptides exhibited high cell selectivity towards bacterial cells over human red blood cells (hRBCs), and the peptide W2 exhibited stronger antimicrobial activities with the MIC values of 2-8μM against various tested bacteria. Not only that, but W2 also showed obvious synergy with streptomycin and chloramphenicol against Escherichia coli, and displayed synergy with ciprofloxacin against Staphylococcus aureus with the FICI values ⩽0.5. Fluorescence spectroscopy and electron microscopy analyses indicated that W2 kills microbial cells by permeabilizing the cell membrane and damaging membrane integrity. Collectively, based on the multiple β-hairpin peptides, the ability to develop libraries of short and effective peptides will be a powerful approach to the discovery of novel antimicrobial agents. We successfully screened a peptide W2 ((WRPGRW)2) from a series of multiple-stranded β-hairpin antimicrobial peptides based on the "S-shaped" motif that induced the formation of a globular structure, and Trp zipper was used to replace the disulfide bonds to reduce the cost of production. This novel structure applied to AMPs improved cell selectivity and salt stability. The findings of this study will promote the development of peptide

Pre-post evaluation of effects of a titanium dioxide coating on environmental contamination of an intensive care unit: the TITANIC study.

Science.gov (United States)

de Jong, B; Meeder, A M; Koekkoek, K W A C; Schouten, M A; Westers, P; van Zanten, A R H

2018-07-01

Among patients admitted to European hospitals or intensive care units (ICUs), 5.7% and 19.5% will encounter healthcare-associated infections (HAIs), respectively, and antimicrobial resistance is emerging. As hospital surfaces are contaminated with potentially pathogenic bacteria, environmental cleanliness is an essential aspect to reduce HAIs. To address the efficacy of a titanium dioxide coating in reducing the microbial colonization of environmental surfaces in an ICU. A prospective, controlled, single-centre pilot study was conducted to examine the effect of a titanium dioxide coating on the microbial colonization of surfaces in an ICU. During the pre- and post-intervention periods, surfaces were cultured with agar contact plates (BBL RODAC plates). Factors that were potentially influencing the bacterial colonization of surfaces were recorded. A repeated measurements analysis within a hierarchic multi-level framework was used to analyse the effect of the intervention, controlling for the explanatory variables. The mean ratio for the total number of colony-forming units (cfus) in a room between the pre- and post-intervention periods was 0.86 (standard deviation 0.57). The optimal model included the following explanatory variables: intervention (P=0.065), week (P=0.002), culture surfaces (P<0.001), ICU room (P=0.039), and interaction between intervention and week (P=0.002) and between week and culture surfaces (P=0.031). The effect of the intervention on the number of cfus from all culture plates in Week 4 between the pre- and post-intervention periods was -0.47 (95% confidence interval -0.24 to - 0.70). This study found that a titanium dioxide coating had no effect on the microbial colonization of surfaces in an ICU. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Green tea as an effective antimicrobial for urinary tract infections caused by Escherichia coli

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Wanda eReygaert

2013-06-01

Full Text Available Background: Urinary tract infections (UTIs are a very most common type of infection worldwide, and result in billions of dollars in medical care costs. Escherichia coli is the infective agent for 80%-90% of all UTIs. Green tea, derived from leaves of the Camellia sinensis plant has been shown to have various potential health benefits (e.g. cardiovascular disease and cancer. The major beneficial components of green tea have been characterized, and are now known to be polyphenolic catechins. The main catechins in green tea are (--epicatechin-3-gallate (ECG, (--epigallocatechin (EGC, (--epicatechin (EC, and (--epigallocatechin-3-gallate (EGCG. EGCG and EGC have been shown to have antimicrobial effects, but only EGC has been shown to be excreted in urine. Isolates of E. coli from urinary tract infections collected between 2007-2008 were characterized for antimicrobial resistance to standard drugs. Then 80 of these isolates, representing a wide spectrum of antimicrobial susceptibility patterns, were selected for testing using an extract of green tea.Results: The concentrations of green tea extract tested were 0, 2.5, 3.0, 3.5, and 4.0 mg/ml. All of the strains tested, except one, had MICs of ≤4.0 mg/ml, with 40% of the isolates having an MIC of ≤2.5 mg/ml, 36% of the isolates having an MIC of ≤3.0 mg/ml, 18% of the isolates having an MIC of ≤3.5 mg/ml, and 5% of the isolates having an MIC of ≤4.0 mg/ml. Two control strains varied in susceptibility, one having an MIC of ≤2.5 mg/ml, another having an MIC of ≤3.5 mg/ml, and the third having an MIC of ≤4.0 mg/ml.Conclusion: Since EGC has been shown to have antimicrobial effects on E. coli, and EGC has been shown to be excreted in the urine in a high enough concentration to potentially be effective as an antimicrobial; these MIC results suggest that ingesting green tea could have potential antimicrobial effects on urinary tract infections caused by E. coli.

Iridium Coating Deposited by Double Glow Plasma Technique — Effect of Glow Plasma on Structure of Coating at Single Substrate Edge

International Nuclear Information System (INIS)

Wu Wangping; Chen Zhaofeng; Liu Yong

2012-01-01

Double glow plasma technique has a high deposition rate for preparing iridium coating. However, the glow plasma can influence the structure of the coating at the single substrate edge. In this study, the iridium coating was prepared by double glow plasma on the surface of single niobium substrate. The microstructure of iridium coating at the substrate edge was observed by scanning electron microscopy. The composition of the coating was confirmed by energy dispersive spectroscopy and X-ray diffraction. There was a boundary between the coating and the substrate edge. The covered area for the iridium coating at the substrate edge became fewer and fewer from the inner area to the outer flange-area. The bamboo sprout-like particles on the surface of the substrate edge were composed of elemental niobium. The substrate edge was composed of the Nb coating and there was a transition zone between the Ir coating and the Nb coating. The interesting phenomenon of the substrate edge could be attributed to the effects of the bias voltages and the plasma cloud in the deposition chamber. The substrate edge effect could be mitigated or eliminated by adding lots of small niobium plates around the substrate in a deposition process. (plasma technology)

Effects of cationic antimicrobial peptides on liquid-preserved boar spermatozoa.

Directory of Open Access Journals (Sweden)

Martin Schulze

Full Text Available Antibiotics are mandatory additives in semen extenders to control bacterial contamination. The worldwide increase in resistance to conventional antibiotics requires the search for alternatives not only for animal artificial insemination industries, but also for veterinary and human medicine. Cationic antimicrobial peptides are of interest as a novel class of antimicrobial additives for boar semen preservation. The present study investigated effects of two synthetic cyclic hexapeptides (c-WFW, c-WWW and a synthetic helical magainin II amide derivative (MK5E on boar sperm during semen storage at 16 °C for 4 days. The standard extender, Beltsville Thawing Solution (BTS containing 250 µg/mL gentamicin (standard, was compared to combinations of BTS with each of the peptides in a split-sample procedure. Examination revealed peptide- and concentration-dependent effects on sperm integrity and motility. Negative effects were more pronounced for MK5E than in hexapeptide-supplemented samples. The cyclic hexapeptides were partly able to stimulate a linear progressive sperm movement. When using low concentrations of cyclic hexapeptides (4 µM c-WFW, 2 µM c-WWW sperm quality was comparable to the standard extender over the course of preservation. C-WFW-supplemented boar semen resulted in normal fertility rates after AI. In order to investigate the interaction of peptides with the membrane, electron spin resonance spectroscopic measurements were performed using spin-labeled lipids. C-WWW and c-WFW reversibly immobilized an analog of phosphatidylcholine (PC, whereas MK5E caused an irreversible increase of PC mobility. These results suggest testing the antimicrobial efficiency of non-toxic concentrations of selected cyclic hexapeptides as potential candidates to supplement/replace common antibiotics in semen preservation.

Effects of cationic antimicrobial peptides on liquid-preserved boar spermatozoa.

Science.gov (United States)

Schulze, Martin; Junkes, Christof; Mueller, Peter; Speck, Stephanie; Ruediger, Karin; Dathe, Margitta; Mueller, Karin

2014-01-01

Antibiotics are mandatory additives in semen extenders to control bacterial contamination. The worldwide increase in resistance to conventional antibiotics requires the search for alternatives not only for animal artificial insemination industries, but also for veterinary and human medicine. Cationic antimicrobial peptides are of interest as a novel class of antimicrobial additives for boar semen preservation. The present study investigated effects of two synthetic cyclic hexapeptides (c-WFW, c-WWW) and a synthetic helical magainin II amide derivative (MK5E) on boar sperm during semen storage at 16 °C for 4 days. The standard extender, Beltsville Thawing Solution (BTS) containing 250 µg/mL gentamicin (standard), was compared to combinations of BTS with each of the peptides in a split-sample procedure. Examination revealed peptide- and concentration-dependent effects on sperm integrity and motility. Negative effects were more pronounced for MK5E than in hexapeptide-supplemented samples. The cyclic hexapeptides were partly able to stimulate a linear progressive sperm movement. When using low concentrations of cyclic hexapeptides (4 µM c-WFW, 2 µM c-WWW) sperm quality was comparable to the standard extender over the course of preservation. C-WFW-supplemented boar semen resulted in normal fertility rates after AI. In order to investigate the interaction of peptides with the membrane, electron spin resonance spectroscopic measurements were performed using spin-labeled lipids. C-WWW and c-WFW reversibly immobilized an analog of phosphatidylcholine (PC), whereas MK5E caused an irreversible increase of PC mobility. These results suggest testing the antimicrobial efficiency of non-toxic concentrations of selected cyclic hexapeptides as potential candidates to supplement/replace common antibiotics in semen preservation.

Antimicrobial polymers.

Science.gov (United States)

Jain, Anjali; Duvvuri, L Sailaja; Farah, Shady; Beyth, Nurit; Domb, Abraham J; Khan, Wahid

2014-12-01

Better health is basic requirement of human being, but the rapid growth of harmful pathogens and their serious health effects pose a significant challenge to modern science. Infections by pathogenic microorganisms are of great concern in many fields such as medical devices, drugs, hospital surfaces/furniture, dental restoration, surgery equipment, health care products, and hygienic applications (e.g., water purification systems, textiles, food packaging and storage, major or domestic appliances etc.) Antimicrobial polymers are the materials having the capability to kill/inhibit the growth of microbes on their surface or surrounding environment. Recently, they gained considerable interest for both academic research and industry and were found to be better than their small molecular counterparts in terms of enhanced efficacy, reduced toxicity, minimized environmental problems, resistance, and prolonged lifetime. Hence, efforts have focused on the development of antimicrobial polymers with all desired characters for optimum activity. In this Review, an overview of different antimicrobial polymers, their mechanism of action, factors affecting antimicrobial activity, and application in various fields are given. Recent advances and the current clinical status of these polymers are also discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Functionalization of Nanostructures and Their Potential Applications in Edible Coatings

Directory of Open Access Journals (Sweden)

Ricardo M. González-Reza

2018-04-01

Full Text Available Nowadays, edible coatings incorporated with nanostructures as systems of controlled release of flavors, colorants and/or antioxidants and antimicrobial substances, also used for thermal and environmental protection of active compounds, represent a gap of opportunity to increase the shelf life of food highly perishable, as well as for the development of new products. These functionalized nanostructures have the benefit of incorporating natural substances obtained from the food industry that are rich in polyphenols, dietary fibers, and antimicrobial substances. In addition, the polymers employed on its preparation, such as polysaccharides, solid lipids and proteins that are low cost and developed through sustainable processes, are friendly to the environment. The objective of this review is to present the materials commonly used in the preparation of nanostructures, the main ingredients with which they can be functionalized and used in the preparation of edible coatings, as well as the advances that these structures have represented when used as controlled release systems, increasing the shelf life and promoting the development of new products that meet the characteristics of functionality for fresh foods ready to eat.

Effectiveness of the actions of antimicrobial's control in the intensive care unit

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Santos Edilson Floriano dos

2003-01-01

Full Text Available There are various strategies to improve the effectiveness of antibiotics in hospitals. In general, the implementation of guidelines for appropriate antibiotic therapy and the participation of infectious disease (ID physicians deserve considerable attention. This study was a prospective ecological time-series study that evaluates the effectiveness of the ID physician's opinion to rationalize and control the use of antibiotics in medical-surgical intensive care units (ICU, and the impact of their intervention on treatment expenditures. There was significant change in the pattern of use of antimicrobials, this pattern approximating that of a medical-surgical ICU that participates in the ICARE (Intensive Care Antimicrobial Resistance Epidemiology Project. For example, there was a significant increase in the consumption of antimicrobials of the ampicillin group (Relative Risk [RR]=3.39; 95% CI: 2.34-4.91 and antipseudomonal penicillins (RR=2.89; 95% CI: 1.70-4.92. On the other hand, there was a significant reduction in the consumption of 3rd/4th generation cephalosporins (RR=0.66; 95% CI: 0.57-0.77 and carbapenems (RR=0.43; 95% CI: 0.33-0.56. On average, for every patient-day antibiotic expense was reduced 37.2% during calendar year 2001, when compared with 2000. The ID specialists' opinion and the adoption of guidelines for empirical antibiotic therapy of hospital-acquired pneumonia contributed to a reduction in the use of antimicrobials in medical-surgical ICU. However, further studies that have more control over confounding variables are needed to help determine the relevance of these discoveries.

Effectiveness of the actions of antimicrobial's control in the intensive care unit

Directory of Open Access Journals (Sweden)

Edilson Floriano dos Santos

Full Text Available There are various strategies to improve the effectiveness of antibiotics in hospitals. In general, the implementation of guidelines for appropriate antibiotic therapy and the participation of infectious disease (ID physicians deserve considerable attention. This study was a prospective ecological time-series study that evaluates the effectiveness of the ID physician's opinion to rationalize and control the use of antibiotics in medical-surgical intensive care units (ICU, and the impact of their intervention on treatment expenditures. There was significant change in the pattern of use of antimicrobials, this pattern approximating that of a medical-surgical ICU that participates in the ICARE (Intensive Care Antimicrobial Resistance Epidemiology Project. For example, there was a significant increase in the consumption of antimicrobials of the ampicillin group (Relative Risk [RR]=3.39; 95% CI: 2.34-4.91 and antipseudomonal penicillins (RR=2.89; 95% CI: 1.70-4.92. On the other hand, there was a significant reduction in the consumption of 3rd/4th generation cephalosporins (RR=0.66; 95% CI: 0.57-0.77 and carbapenems (RR=0.43; 95% CI: 0.33-0.56. On average, for every patient-day antibiotic expense was reduced 37.2% during calendar year 2001, when compared with 2000. The ID specialists' opinion and the adoption of guidelines for empirical antibiotic therapy of hospital-acquired pneumonia contributed to a reduction in the use of antimicrobials in medical-surgical ICU. However, further studies that have more control over confounding variables are needed to help determine the relevance of these discoveries.

Green synthesis of Kocuran-functionalized silver glyconanoparticles for use as antibiofilm coatings on silicone urethral catheters

International Nuclear Information System (INIS)

Kumar, C Ganesh; Sujitha, Pombala

2014-01-01

Microbial infections due to biofilm formation on medical implants are serious complications arising after surgery which can be prevented by using antimicrobial coatings on biomaterial surfaces. We developed a simple, rapid and green chemistry approach for synthesis of silver glyconanoparticles (AgNPs) using Kocuran, an exopolysaccharide produced by Kocuria rosea strain BS-1. Kocuran-capped AgNPs exhibited a characteristic surface plasmon resonance (SPR) peak around 435 nm. They were mono-dispersed, spherical with an average particle size of 12 nm. XRD and SAED studies suggested that AgNPs were crystalline in nature. AgNPs had a zeta potential of −33.9 mV and were anionic charged. They showed colloidal stability at different pH (6 to 10), temperatures (30 °C to 100 °C), in NaCl, NaNO 3 and BSA solutions. Kocuran-capped AgNPs exhibited effective antimicrobial activity against Staphylococcus aureus and Escherichia coli and cell death was mainly due to hydroxyl radical induction and depletion of NADH. They also inhibited the biofilm development by S. aureus and E. coli and confocal scanning laser microscopic images revealed the damage of intact cell architecture. In vitro evaluation of Kocuran-capped silver glyconanoparticles on human gingival fibroblasts demonstrated good cell proliferation as compared to commercial AgNPs suggesting that they are biocompatible and non-toxic in nature. This is a first report on Kocuran-functionalized AgNPs exhibiting potential antibacterial and antiadhesive properties for use as antimicrobial coatings against bacterial adhesion and biofilm formation on silicone urethral catheters. (paper)

Efficacy of triclosan as an antimicrobial hand soap and its potential impact on antimicrobial resistance: a focused review.

Science.gov (United States)

Giuliano, Christopher A; Rybak, Michael J

2015-03-01

Triclosan is a synthetic biocide found in many household products, including antimicrobial hand soap. Levels of triclosan have been found throughout the environment and in human urine, blood, and even breast milk. Increasing levels of exposure to triclosan have led to concerns over the development of resistance to triclosan and cross-resistance to other antimicrobials. We performed a literature search to assess whether the widespread use of triclosan displays a favorable benefit: risk ratio, defined by evaluation of triclosan's efficacy as an antimicrobial hand soap and its potential effect on the development of antimicrobial resistance. Data from laboratory-based studies regarding the efficacy of triclosan are conflicting, although well-designed studies suggest no significant difference in efficacy over nonantimicrobial soap. In addition, when triclosan was introduced in a community setting, no beneficial effects were observed on the reduction of infections over nonantimicrobial soap. Resistance to triclosan and cross-resistance to antimicrobials have been consistently demonstrated in laboratory settings, although overall resistance rates and cross-resistance rates in the community setting are low. Based on the available evidence, the risk of potential antimicrobial resistance outweighs the benefit of widespread triclosan use in antimicrobial soaps. © 2015 Pharmacotherapy Publications, Inc.

Effect of different scenarios for selective dry-cow therapy on udder health, antimicrobial usage, and economics.

Science.gov (United States)

Scherpenzeel, C G M; den Uijl, I E M; van Schaik, G; Riekerink, R G M Olde; Hogeveen, H; Lam, T J G M

2016-05-01

The goal of dry-cow therapy (DCT) is to reduce the prevalence of intramammary infections (IMI) by eliminating existing IMI at drying off and preventing new IMI from occurring during the dry period. Due to public health concerns, however, preventive use of antimicrobials has become questionable. In this study, we evaluated the effects of 8 scenarios for selecting animals for DCT, taking into account variation in parity and cow-level somatic cell count (SCC) at drying off. The aim of this study was to evaluate udder health, antimicrobial usage, and economics at the herd level when using different scenarios for selecting cows for DCT. To enable calculation and comparison of the effects of different scenarios to select cows for DCT in an "average" herd, we created an example herd, with a virtual herd size of 100 dairy cows to be calving during a year. Udder health, antimicrobial usage, and economics were evaluated during the dry period and the first 100 d in lactation, the period during which the greatest effect of DCT is expected. This leads to an estimated 13,551 cow-days at risk during a year in a 100-cow dairy herd. In addition to a blanket DCT (BDCT) scenario, we developed 7 scenarios to select cows for DCT based on SCC. The scenarios covered a range of possible approaches to select low-SCC cows for DCT, all based on cow-level SCC thresholds on the last milk recording before drying off. The incidence rate of clinical mastitis in the example herd varied from 11.6 to 14.5 cases of clinical mastitis per 10,000 cow-days at risk in the different scenarios, and the prevalence of subclinical mastitis varied from 38.8% in scenario 1 (BDCT) to 48.3% in scenario 8. Total antimicrobial usage for DCT and clinical mastitis treatment varied over the scenarios from 1.27 (scenario 8) to 3.15 animal daily dosages (BDCT), leading to a maximum reduction in antimicrobial usage of 60% for scenario 8 compared with BDCT. The total costs for each of the scenarios showed little variation

Adhesive coatings based on melanin-like nanoparticles for surgical membranes.

Science.gov (United States)

Scognamiglio, Francesca; Travan, Andrea; Turco, Gianluca; Borgogna, Massimiliano; Marsich, Eleonora; Pasqua, Mattia; Paoletti, Sergio; Donati, Ivan

2017-07-01

Adhesive coatings for implantable biomaterials can be designed to prevent material displacement from the site of implant. In this paper, a strategy based on the use of melanin-like nanoparticles (MNPs) for the development of adhesive coatings for polysaccharidic membranes was devised. MNPs were synthesized in vitro and characterized in terms of dimensions and surface potential, as a function of pH and ionic strength. The in vitro biocompatibility of MNPs was investigated on fibroblast cells, while the antimicrobial properties of MNPs in suspension were evaluated on E. coli and S. aureus cultures. The manufacturing of the adhesive coatings was carried out by spreading MNPs over the surface of polysaccharidic membranes; the adhesive properties of the nano-engineered coating to the target tissue (intestinal serosa) were studied in simulated physiological conditions. Overall, this study opens for novel approaches in the design of naturally inspired nanostructured adhesive systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Deposition stress effects on thermal barrier coating burner rig life

Science.gov (United States)

Watson, J. W.; Levine, S. R.

1984-01-01

A study of the effect of plasma spray processing parameters on the life of a two layer thermal barrier coating was conducted. The ceramic layer was plasma sprayed at plasma arc currents of 900 and 600 amps onto uncooled tubes, cooled tubes, and solid bars of Waspalloy in a lathe with 1 or 8 passes of the plasma gun. These processing changes affected the residual stress state of the coating. When the specimens were tested in a Mach 0.3 cyclic burner rig at 1130 deg C, a wide range of coating lives resulted. Processing factors which reduced the residual stress state in the coating, such as reduced plasma temperature and increased heat dissipation, significantly increased coating life.

Effect of structural animal health planning on antimicrobial use and animal health variables in conventional dairy farming in the Netherlands.

Science.gov (United States)

Speksnijder, David C; Graveland, Haitske; Eijck, Ineke A J M; Schepers, René W M; Heederik, Dick J J; Verheij, Theo J M; Wagenaar, Jaap A

2017-06-01

Widespread veterinary use of antimicrobials might contribute to the increasing burden of antimicrobial resistance. Despite many successful efforts to reduce veterinary antimicrobial use in the Netherlands, antimicrobial use on a substantial number of farms has remained relatively high over the past few years. Farm-specific solutions are required to further lower antimicrobial use on these farms. Reducing the burden of animal diseases at the farm level by means of a structured approach to animal health planning could be promising. This intervention study aimed to evaluate the main effects of an animal health planning program developed by an advisory team consisting of a dairy farmer, his veterinarian, and his feed adviser under the guidance of a professional facilitator. During an initial farm visit, the advisory team developed a farm-specific animal health planning program with support from the facilitator. After 1 yr, the effects of this program on animal health, production parameters, and antimicrobial use were evaluated and compared with control farms that did not have a facilitated animal health planning program. Antimicrobial use on intervention farms was significantly reduced between the start and the end of the study period; however, no significant differences in the rate of reduction between the intervention and control groups could be observed (-19% and -14%, respectively). Reduced antimicrobial use did not result in negative effects on animal health and production parameters during the study period in both groups. On intervention farms, a significant positive relationship was found between the percentage of completed action points at farm level and the percentage reduction in antimicrobial use. The level of compliance with action points and the quality of collaboration between farmer and advisers were positively associated with the accomplishment of corresponding objectives. However, the total number of objectives was negatively associated with the level

Effect of a gelatin-based edible coating containing cellulose nanocrystals (CNC) on the quality and nutrient retention of fresh strawberries during storage

Science.gov (United States)

Fakhouri, F. M.; Casari, A. C. A.; Mariano, M.; Yamashita, F.; Innocnentini Mei, L. H.; Soldi, V.; Martelli, S. M.

2014-08-01

Strawberry is a non-climacteric fruit with a very short postharvest shelf-life. Loss of quality in this fruit is mostly due to its relatively high metabolic activity and sensitivity to fungal decay, meanly grey mold (Botrytis cinerea). In this study, the ability of gelatin coatings containing cellulose nanocrystals (CNC) to extend the shelf-life of strawberry fruit (Fragaria ananassa) over 8 days were studied. The filmogenic solution was obtained by the hydration of 5 g of gelatin (GEL) in 100 mL of distillated water containing different amounts of CNC dispersion (10 mg CNC/g of GEL or 50 mg of CNC/g of GEL) for 1 hour at room temperature. After this period, the solution was heated to 70 °C and maintained at this temperature for 10 minutes. The plasticizer (glycerol) (10g/100g of the GEL) was then added with constant, gentle stirring in order to avoid forming air bubbles and also to avoid gelatin denaturation until complete homogenization. Strawberries (purchased at the local market) were immersed in the filmogenic solution for 1 minute and after coated were dried at 15 °C by 24 hours. The strawberries were then kept under refrigeration and characterized in terms of their properties (weight loss, ascorbic acid content, titratable acidity, water content). The results have shown that samples covered with GEL/CNC had a significant improvement in its shelf- life. For instance, for the control sample (without coating) the weight loss after 8 days of storage was around 65%, while covered samples loss in the range of 31-36%. Edible coating was also effective in the retention of ascorbic acid (AA) in the strawberries, while control sample presented a fast decay in the AA content, covered samples showed a slow decay in the AA concentration. Moreover, the use of GEL/CNC edible coating had an antimicrobial effect in the fruits.

Effect of a gelatin-based edible coating containing cellulose nanocrystals (CNC) on the quality and nutrient retention of fresh strawberries during storage

International Nuclear Information System (INIS)

Fakhouri, F M; Casari, A C A; Martelli, S M; Mariano, M; Soldi, V; Yamashita, F; Mei, L H Innocnentini

2014-01-01

Strawberry is a non-climacteric fruit with a very short postharvest shelf-life. Loss of quality in this fruit is mostly due to its relatively high metabolic activity and sensitivity to fungal decay, meanly grey mold (Botrytis cinerea). In this study, the ability of gelatin coatings containing cellulose nanocrystals (CNC) to extend the shelf-life of strawberry fruit (Fragaria ananassa) over 8 days were studied. The filmogenic solution was obtained by the hydration of 5 g of gelatin (GEL) in 100 mL of distillated water containing different amounts of CNC dispersion (10 mg CNC/g of GEL or 50 mg of CNC/g of GEL) for 1 hour at room temperature. After this period, the solution was heated to 70 °C and maintained at this temperature for 10 minutes. The plasticizer (glycerol) (10g/100g of the GEL) was then added with constant, gentle stirring in order to avoid forming air bubbles and also to avoid gelatin denaturation until complete homogenization. Strawberries (purchased at the local market) were immersed in the filmogenic solution for 1 minute and after coated were dried at 15 °C by 24 hours. The strawberries were then kept under refrigeration and characterized in terms of their properties (weight loss, ascorbic acid content, titratable acidity, water content). The results have shown that samples covered with GEL/CNC had a significant improvement in its shelf- life. For instance, for the control sample (without coating) the weight loss after 8 days of storage was around 65%, while covered samples loss in the range of 31-36%. Edible coating was also effective in the retention of ascorbic acid (AA) in the strawberries, while control sample presented a fast decay in the AA content, covered samples showed a slow decay in the AA concentration. Moreover, the use of GEL/CNC edible coating had an antimicrobial effect in the fruits

[BIOLOGICAL ACTIVITY OF ANTIMICROBIAL PEPTIDES FROM CHICKENS THROMBOCYTES].

Science.gov (United States)

Sycheva, M V; Vasilchenko, A S; Rogozhin, E A; Pashkova, T M; Popova, L P; Kartashova, O L

2016-01-01

Isolation and study of biological activity of antimicrobial peptides from chickens thrombocytes. Peptides from chickens thrombocytes, obtained by reverse-phase high-performance liquid chromatography method with stepped and linear gradients of concentration increase of the organic solvent were used in the study. Their antimicrobial activity was determined by microtitration method in broth; mechanism of biological effect--by using fluorescent spectroscopy method with DNA-tropic dyes. Individual fractions of peptides were isolated from chickens thrombocytes, that possess antimicrobial activity against Staphylococcus aureus P209 and Escherichia coli K12. A disruption of integrity of barrier structures of microorganisms under the effect of thrombocyte antimicrobial peptides and predominance of cells with damaged membrane in the population of E. coli was established. The data obtained on antimicrobial activity and mechanism of bactericidal effect of the peptide fractions from chickens thrombocytes isolated for the first time expand the understanding of functional properties of chickens thrombocytes and open a perspective for their further study with the aim of use as antimicrobial means.

Tuning antimicrobial properties of biomimetic nanopatterned surfaces.

Science.gov (United States)

Michalska, Martyna; Gambacorta, Francesca; Divan, Ralu; Aranson, Igor S; Sokolov, Andrey; Noirot, Philippe; Laible, Philip D

2018-04-05

Nature has amassed an impressive array of structures that afford protection from microbial colonization/infection when displayed on the exterior surfaces of organisms. Here, controlled variation of the features of mimetics derived from etched silicon allows for tuning of their antimicrobial efficacy. Materials with nanopillars up to 7 μm in length are extremely effective against a wide range of microbial species and exceed the performance of natural surfaces; in contrast, materials with shorter/blunter nanopillars (<2 μm) selectively killed specific species. Using a combination of microscopies, the mechanisms by which bacteria are killed are demonstrated, emphasizing the dependence upon pillar density and tip geometry. Additionally, real-time imaging reveals how cells are immobilized and killed rapidly. Generic or selective protection from microbial colonization could be conferred to surfaces [for, e.g., internal medicine, implants (joint, dental, and cosmetic), food preparation, and the agricultural industry] patterned with these materials as coatings.

Antimicrobial effectiveness of oregano and sage essential oils incorporated into whey protein films or cellulose-based filter paper.

Science.gov (United States)

Royo, Maite; Fernández-Pan, Idoya; Maté, Juan I

2010-07-01

In this study the antimicrobial effectiveness of oregano and sage essential oils (EOs) incorporated into two different matrices, whey protein isolate (WPI) and cellulose-based filter paper, was analysed. Antimicrobial properties of WPI-based films containing oregano and sage EOs were tested against Listeria innocua, Staphylococcus aureus and Salmonella enteritidis. Oregano EO showed antimicrobial activity against all three micro-organisms. The highest inhibition zones were against L. innocua. However, sage EO did not show antimicrobial activity against any of the micro-organisms. Antimicrobial activity was confirmed for both EOs using cellulose-based filter paper as supporting matrix, although it was significantly more intense for oregano EO. Inhibition surfaces were significantly greater when compared with those of the WPI films. This finding is likely due to the higher porosity and diffusivity of the active compounds in the filter paper. The interactions between the EOs and the films have a critical effect on the diffusivity of the active compounds and therefore on the final antimicrobial activity. As a result, to obtain active edible films, it is necessary to find the equilibrium point between the nature and concentration of the active compounds in the EO and the formulation of the film.

Antimicrobial stewardship initiatives throughout Europe: proven value for money

Directory of Open Access Journals (Sweden)

Edwin J.M. Oberjé

2017-03-01

Full Text Available Antimicrobial stewardship is recognized as a key component to stop the current European spread of antimicrobial resistance. It has also become evident that antimicrobial resistance is a problem that cannot be tackled by single institutions or physicians. Prevention of antimicrobial resistance needs rigorous actions at ward level, institution level, national level and at supra-national levels. Countries can learn from each other and possibly transplant best practices across borders to prevent antimicrobial resistance. The aim of this study is to highlight some of the success stories of proven cost-effective interventions, and to describe the actions that have been taken, the outcomes that have been found, and the difficulties that have been met. In some cases we came across substantial scope for real-life cost savings. Although the best approach to effectively hinder the spread of antimicrobial resistance remains unclear and may vary significantly among settings, several EU-wide examples demonstrate that cost-effective antimicrobial stewardship is possible. Such examples can encourage others to implement (the most cost-effective elements in their system.

Antitumour, Antimicrobial, Antioxidant and Antiacetylcholinesterase Effect of Ganoderma Lucidum Terpenoids and Polysaccharides: A Review.

Science.gov (United States)

Cör, Darija; Knez, Željko; Knez Hrnčič, Maša

2018-03-13

Ganoderma lucidum (Reishi) is a popular medicinal mushroom and has been used in oriental medicine because of its promoting effects on health and life expectancy. G. lucidum contains various compounds with a high grade of biological activty, which increase the immunity and show antitumour, antimicrobial, anti-inflammatory, antioxidant and acetylcholinesterase inhibitory activity. Several of these substances belong to the triterpenoids and polysaccharides classes. Proteins, lipids, phenols, sterols, etc. are also present. In the present review, an extensive overview of the presence of antitumour, antimicrobial, antioxidant and antiacetylcholinesterase compounds in G. lucidum extracts will be given, along with an evaluation of their therapeutic effects.

An environmentally benign antimicrobial nanoparticle based ...

Science.gov (United States)

Silver nanoparticles have antibacterial properties but their use has been a cause for concern because they persist in the environment. Here we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and together with silver ions can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies showed that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles

Effect of Anode Dielectric Coating on Hall Thruster Operation

International Nuclear Information System (INIS)

Dorf, L.; Raitses, Y.; Fisch, N.J.; Semenov, V.

2003-01-01

An interesting phenomenon observed in the near-anode region of a Hall thruster is that the anode fall changes from positive to negative upon removal of the dielectric coating, which is produced on the anode surface during the normal course of Hall thruster operation. The anode fall might affect the thruster lifetime and acceleration efficiency. The effect of the anode coating on the anode fall is studied experimentally using both biased and emissive probes. Measurements of discharge current oscillations indicate that thruster operation is more stable with the coated anode

Effects of dentin on the antimicrobial properties of endodontic medicaments.

Science.gov (United States)

Haapasalo, Markus; Qian, Wei; Portenier, Isabelle; Waltimo, Tuomas

2007-08-01

Successful treatment of apical periodontitis is dependent on the elimination of the infective microflora from the necrotic root canal system. Antimicrobial irrigating solutions and other locally used disinfecting agents and medicaments have a key role in the eradication of the microbes. While most if not all presently used disinfecting agents rapidly kill even the resistant microbes when tested in vitro in a test tube, the effectiveness of the same agents is clearly weaker in the in vivo conditions. Recent studies have given valuable information about the interaction of endodontic disinfecting agents with dentin and other compounds present in the necrotic root canal. As a result of such interactions the antimicrobial effectiveness of several of our key disinfectants may be weakened, or even eliminated under certain circumstances. Different disinfectants show different sensitivity to the action by the various potential inactivators, such as dentin, serum proteins, hydroxyapatite, collagen derived from different sources, and microbial biomass. This review is a summary of our present knowledge of the mostly negative interactions between endodontic disinfecting agents and the various compounds present in the root canal environment.

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

Science.gov (United States)

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

2017-10-01

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

Effect of Graphene Nanoplatelets on the Physical and Antimicrobial Properties of Biopolymer-Based Nanocomposites

Directory of Open Access Journals (Sweden)

Roberto Scaffaro

2016-05-01

Full Text Available In this work, biopolymer-based nanocomposites with antimicrobial properties were prepared via melt-compounding. In particular, graphene nanoplatelets (GnPs as fillers and an antibiotic, i.e., ciprofloxacin (CFX, as biocide were incorporated in a commercial biodegradable polymer blend of poly(lactic acid (PLA and a copolyester (BioFlex®. The prepared materials were characterized by scanning electron microscopy (SEM, and rheological and mechanical measurements. Moreover, the effect of GnPs on the antimicrobial properties and release kinetics of CFX was evaluated. The results indicated that the incorporation of GnPs increased the stiffness of the biopolymeric matrix and allowed for the tuning of the release of CFX without hindering the antimicrobial activity of the obtained materials.

Inactivation of microbial infectiousness by silver nanoparticles-coated condom: a new approach to inhibit HIV- and HSV-transmitted infection

Directory of Open Access Journals (Sweden)

Mohammed Fayaz A

2012-09-01

Full Text Available A Mohammed Fayaz,1,* Zhujun Ao,1,3,* Morkattu Girilal,2 Liyu Chen,3,4 Xianzhong Xiao,4 PT Kalaichelvan,2 Xiaojian Yao1,31Laboratory of Molecular Human Retrovirology, Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB, Canada; 2CAS in Botany, University of Madras, Guindy Campus, Chennai, Tamil Nadu, India; 3Department of Microbiology, 4School of Basic Medical Sciences, Central South University, Changsha, Hunan, People’s Republic of China*Both authors contributed equally to this workAbstract: Recent research suggests that today’s condoms are only 85% effective in preventing human immunodeficiency virus (HIV and other sexually transmitted diseases. In response, there has been a push to develop more effective ways of decreasing the spread of the disease. The new nanotechnology-based condom holds the promise of being more potent than the first-generation products. The preliminary goal of this study was to develop a silver nanoparticles (Ag-NPs-coated polyurethane condom (PUC and to investigate its antimicrobial potential including the inactivation of HIV and herpes simplex virus (HSV infectiousness. The Ag-NPs-coated PUC was characterized by using ultraviolet-visible spectrophotometry, Fourier transform-infrared spectroscopy, high-resolution scanning electron microscopy, and energy-dispersive analysis of X-ray spectroscopy. Nanoparticles were stable on the PUC and not washed away by water. Morphology of the PUC was retained after coating. The NP binding is due to its interaction with the nitrogen atom of the PUC. No significant toxic effects was observed when human HeLa cells, 293T and C8166 T cells were contacted to Ag-NPs-coated PUC for three hours. Interestingly, our results demonstrated that the contact of the Ag-NPs-coated PUC with HIV-1 and HSV-1/2 was able to efficiently inactivate their infectiousness. In an attempt to elucidate the antiviral action of the Ag-NPs, we have demonstrated that the

Effect of Rheological Properties on Liquid Curtain Coating

Science.gov (United States)

Mohammad Karim, Alireza; Suszynski, Wieslaw; Griffith, William; Pujari, Saswati; Carvalho, Marcio; Francis, Lorraine; Dow Chemical Company Collaboration; PUC-Rio Collaboration

2017-11-01

Curtain coating is one of the preferred methods for high-speed precision application of single-layer and multi-layer coatings in technology. However, uniform coatings are only obtained in a certain range of operating parameters, called coating window. The two main physical mechanisms that limit successful curtain coating are liquid curtain breakup and air entrainment. The rheological properties of the liquid play an important role on these mechanisms, but the fundamental understanding of these relations is still not complete. The effect of rate-dependent shear and extensional viscosities on the stability of viscoelastic and shear thinning liquid curtains were explored by high-speed visualization. Aqueous solutions of polyethylene oxide (PEO) and polyethylene glycol (PEG) were used as viscoelastic liquids. Xanthan Gum in water and glycerol solutions with a range of compositions were used as shear thinning liquids. The critical condition was determined by examining flow rate below which curtain broke. In this work, we also analyze relative importance of rate-dependent shear and extensional viscosity on both curtain breakup and air entrainment. We would like to acknowledge the financial support from the Dow Chemical Company.

Relative effectiveness of electron-proton damage on organic coatings

International Nuclear Information System (INIS)

Bartolomei, P.; Cabrini, A.

1988-01-01

With aim to verify the validity of simulation with photon irradiators, of damage caused on internal containment coatings by beta plus gamma mixed field following to a LOCA in LWR, irradiation tests with Co 60 photon and with nearly 1.5 MeV mean energy electrons have been performed. Changes of some properties of coating film have been verified versus absorbed doses up to 1000 KGy (100 Mrad). A special technique for measurement of dose absorbed in thin film of coating has been tested, to be related to absorbed dose in organic dosimeters and in water (Fricke solution) dosimeter. The changes of considered properties (tensile strength, ease to decontamination, color, brightness) do not allow at the moment, to determine undoubtedly the degree of equivalence between radiation damage to coatings by two types of radiation. A strong backscatter effect mainly evident in electron irradiation, has been pointed out, which contribute to damage to coating film

Comparative evaluation of antimicrobials for textile applications.

Science.gov (United States)

Windler, Lena; Height, Murray; Nowack, Bernd

2013-03-01

Many antimicrobial technologies are available for textiles. They may be used in many different textile applications to prevent the growth of microorganisms. Due to the biological activity of the antimicrobial compounds, the assessment of the safety of these substances is an ongoing subject of research and regulatory scrutiny. This review aims to give an overview on the main compounds used today for antimicrobial textile functionalization. Based on an evaluation of scientific publications, market data as well as regulatory documents, the potential effects of antimicrobials on the environment and on human health were considered and also life cycle perspectives were taken into account. The characteristics of each compound were summarized according to technical, environmental and human health criteria. Triclosan, silane quaternary ammonium compounds, zinc pyrithione and silver-based compounds are the main antimicrobials used in textiles. The synthetic organic compounds dominate the antimicrobials market on a weight basis. On the technical side the application rates of the antimicrobials used to functionalize a textile product are an important parameter with treatments requiring lower dosage rates offering clear benefits in terms of less active substance required to achieve the functionality. The durability of the antimicrobial treatment has a strong influence on the potential for release and subsequent environmental effects. In terms of environmental criteria, all compounds were rated similarly in effective removal in wastewater treatment processes. The extent of published information about environmental behavior for each compound varies, limiting the possibility for an in-depth comparison of all textile-relevant parameters across the antimicrobials. Nevertheless the comparative evaluation showed that each antimicrobial technology has specific risks and benefits that should be taken into account in evaluating the suitability of different antimicrobial products. The

Efficacy of silver coated surgical sutures on bacterial contamination, cellular response and wound healing

International Nuclear Information System (INIS)

Gallo, Anna Lucia; Paladini, Federica; Romano, Alessandro; Verri, Tiziano; Quattrini, Angelo; Sannino, Alessandro; Pollini, Mauro

2016-01-01

The resistance demonstrated by many microorganisms towards conventional antibiotics has stimulated the interest in alternative antimicrobial agents and in novel approaches for prevention of infections. Silver, a natural braod-spectrum antimicrobial agent known since antiquity, has been widely employed in biomedical field due to its recognized antibacterial, antifungal and antiviral properties. In this work, antibacterial silver coatings were deposited on absorbable surgical sutures through the in situ photo-chemical deposition of silver clusters. Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and thermo-gravimetric analysis (TGA) were performed in order to investigate the presence and distribution of the silver clusters on the substrate. The amounts of silver deposited and released by the silver treated sutures were calculated through Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS), and the results were related to the biodegradation of the material. The microbiological properties and the potential cytotoxicity of the silver-treated sutures were investigated in relation with hydrolysis experiments, in order to determine the effect of the degradation on antibacterial properties and biocompatibility. - Highlights: • The in situ photo-deposition of silver nano-coatings was used to develop silver treated PGLA sutures. • The silver particles deposited had good distribution and strong adhesion to the substrate. • The silver treated sutures demonstrated good biocompatibility and antibacterial capability. • The presence of silver promoted cell migration and proliferation in the wound area.

Efficacy of silver coated surgical sutures on bacterial contamination, cellular response and wound healing

Energy Technology Data Exchange (ETDEWEB)

Gallo, Anna Lucia [Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce (Italy); Paladini, Federica, E-mail: federica.paladini@unisalento.it [Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce (Italy); Romano, Alessandro [Neuropathology Unit, Institute of Experimental Neurology and Division of Neuroscience, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132 Milan (Italy); Verri, Tiziano [Di.S.Te.B.A., University of Salento, Via per Monteroni, 73100 Lecce (Italy); Quattrini, Angelo [Neuropathology Unit, Institute of Experimental Neurology and Division of Neuroscience, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132 Milan (Italy); Sannino, Alessandro; Pollini, Mauro [Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce (Italy)

2016-12-01

The resistance demonstrated by many microorganisms towards conventional antibiotics has stimulated the interest in alternative antimicrobial agents and in novel approaches for prevention of infections. Silver, a natural braod-spectrum antimicrobial agent known since antiquity, has been widely employed in biomedical field due to its recognized antibacterial, antifungal and antiviral properties. In this work, antibacterial silver coatings were deposited on absorbable surgical sutures through the in situ photo-chemical deposition of silver clusters. Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and thermo-gravimetric analysis (TGA) were performed in order to investigate the presence and distribution of the silver clusters on the substrate. The amounts of silver deposited and released by the silver treated sutures were calculated through Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS), and the results were related to the biodegradation of the material. The microbiological properties and the potential cytotoxicity of the silver-treated sutures were investigated in relation with hydrolysis experiments, in order to determine the effect of the degradation on antibacterial properties and biocompatibility. - Highlights: • The in situ photo-deposition of silver nano-coatings was used to develop silver treated PGLA sutures. • The silver particles deposited had good distribution and strong adhesion to the substrate. • The silver treated sutures demonstrated good biocompatibility and antibacterial capability. • The presence of silver promoted cell migration and proliferation in the wound area.

Preliminary coating design and coating developments for ATHENA

DEFF Research Database (Denmark)

Jakobsen, Anders Clemen; Ferreira, Desiree Della Monica; Christensen, Finn Erland

2011-01-01

We present initial novel coating design for ATHENA. We make use of both simple bilayer coatings of Ir and B4C and more complex constant period multilayer coatings to enhance the effective area and cover the energy range from 0.1 to 10 keV. We also present the coating technology used...... for these designs and present test results from coatings....

Low cytotoxic trace element selenium nanoparticles and their differential antimicrobial properties against S. aureus and E. coli

International Nuclear Information System (INIS)

Tran, Phong A; Biswas, Dhee P; O’Connor, Andrea J; O’Brien-Simpson, Neil; Reynolds, Eric C; Pantarat, Namfon

2016-01-01

Antimicrobial agents that have no or low cytotoxicity and high specificity are desirable to have no or minimal side effects. We report here the low cytotoxicity of polyvinyl alcohol-stabilized selenium (Se) nanoparticles and their differential effects on growth of S. aureus, a gram-positive bacterium and E. coli, a gram-negative bacterium. The nanoparticles were synthesised through redox reactions in an aqueous environment at room temperature and were characterised using UV visible spectrophotometry, transmission electron microscopy, dynamic light scattering and x-ray photoelectron spectroscopy. The nanoparticles showed low toxicity toward fibroblasts which remained more than 70% viable at Se concentrations as high as 128 ppm. The nanoparticles also exhibited very low haemolysis with only 18% of maximal lysis observed at a Se concentration of 128 ppm. Importantly, the nanoparticles showed strong growth inhibition toward S. aureus at a concentration as low as 1 ppm. Interestingly, growth of E. coli was unaffected at all concentrations tested. This study therefore strongly suggests that these nanoparticles should be investigated further to understand this differential effect as well as for potential advanced antimicrobial applications such as S. aureus infection—resisting, non-cytotoxic coatings for medical devices. (paper)

Development and characterization of multilayer films of polyaniline, titanium dioxide and CTAB for potential antimicrobial applications

Energy Technology Data Exchange (ETDEWEB)

Farias, Emanuel Airton O.; Dionisio, Natália A.; Quelemes, Patrick V. [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, CMRV, UFPI, Parnaíba, PI 64202-020 (Brazil); Leal, Sergio Henrique [CCNH, UFABC, Santo André, SP 09210-170 (Brazil); Matos, José Milton E.; Filho, Edson C. Silva [Laboratório Interdisciplinar de Materiais Avançados, LIMAv, CCN, UFPI, Teresina, PI 64049-550 (Brazil); Bechtold, Ivan H. [Departamento de Física — UFSC, Florianópolis, SC 88040-900 (Brazil); Leite, José Roberto S.A. [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, CMRV, UFPI, Parnaíba, PI 64202-020 (Brazil); Eiras, Carla, E-mail: carla.eiras.ufpi@gmail.com [Núcleo de Pesquisa em Biodiversidade e Biotecnologia, BIOTEC, CMRV, UFPI, Parnaíba, PI 64202-020 (Brazil); Laboratório Interdisciplinar de Materiais Avançados, LIMAv, CCN, UFPI, Teresina, PI 64049-550 (Brazil)

2014-02-01

Composites prepared from polyaniline (PANI) and the ceramic technology of titanium dioxide (TiO{sub 2}) have been proposed, however, the interaction of these materials with greater control of molecular arrangement becomes attractive in order to achieve properties not previously described or yet the optimization of those already reported. Therefore, in this study, thin hybrid films made of polyaniline (PANI), a conductive polymer, and the technological ceramic, titanium dioxide (TiO{sub 2}), were prepared by the layer-by-layer (LbL) self-assembly technique. The films were characterized by cyclic voltammetry (CV), UV–VIS spectroscopy and atomic force microscopy (AFM). Aiming to improve the dispersion of the ceramic in the polymer matrix, the commercial surfactant, cetyl trimethylammonium bromide (CTAB), was used in the formation of the films. The best condition of deposition was found showing synergic interactions between the conjugated materials. The antibacterial activity of the PANI(TiO{sub 2})/CTAB films was studied and the obtained results suggest their use as antimicrobial coatings. - Highlights: • Nanocomposite films of PANI and TiO2 prepared by the LbL technique • Ceramic dispersion in PANI improved with CTAB for antimicrobial applications. • Optimized film deposition for synergic interactions of the conjugated materials • Antibacterial activity of the films suggests their use as antimicrobial coatings.

Antibacterial effect of doxycycline-coated dental abutment surfaces

International Nuclear Information System (INIS)

Xing, Rui; Tiainen, Hanna; Shabestari, Maziar; Lyngstadaas, Ståle P; Haugen, Håvard J; Witsø, Ingun L; Lönn-Stensrud, Jessica; Jugowiec, Dawid

2015-01-01

Biofilm formation on dental abutment may lead to peri-implant mucositis and subsequent peri-implantitis. These cases are clinically treated with antibiotics such as doxycycline (Doxy). Here we used an electrochemical method of cathodic polarization to coat Doxy onto the outer surface of a dental abutment material. The Doxy-coated surface showed a burst release in phosphate-buffered saline during the first 24 h. However, a significant amount of Doxy remained on the surface for at least 2 weeks especially on a 5 mA–3 h sample with a higher Doxy amount, suggesting both an initial and a long-term bacteriostatic potential of the coated surface. Surface chemistry was analyzed by x-ray photoelectron spectroscopy and secondary ion mass spectrometry. Surface topography was evaluated by field emission scanning electron microscopy and blue-light profilometry. Longer polarization time from 1 h to 5 h and higher current density from 1 to 15 mA cm −2 resulted in a higher amount of Doxy on the surface. The surface was covered by a layer of Doxy less than 100 nm without significant changes in surface topography. The antibacterial property of the Doxy-coated surface was analyzed by biofilm and planktonic growth assays using Staphylococcus epidermidis. Doxy-coated samples reduced both biofilm accumulation and planktonic growth in broth culture, and also inhibited bacterial growth on agar plates. The antibacterial effect was stronger for samples of 5 mA–3 h coated with a higher amount of Doxy compared to that of 1 mA–1 h. Accordingly, an abutment surface coated with Doxy has potential for preventing bacterial colonization when exposed to the oral cavity. Doxy-coating could be a viable way to control peri-implant mucositis and prevent its progression into peri-implantitis. (paper)

Potential Negative Effects of Antimicrobial Allergy Labelling on Patient Care: A Systematic Review.

Science.gov (United States)

Wu, Julie Hui-Chih; Langford, Bradley J; Schwartz, Kevin L; Zvonar, Rosemary; Raybardhan, Sumit; Leung, Valerie; Garber, Gary

2018-01-01

Antimicrobial allergy labels, either self-reported or placed in a patient's medical record, are common, but in many cases they are not associated with a true immunoglobulin E-mediated allergic response. To assess the impact of antimicrobial allergy labels on antimicrobial prescribing, resource utilization, and clinical outcomes. The MEDLINE, Embase, CINAHL, and Scopus electronic databases were searched for the period 1990 to January 2016. Controlled studies with the objective of assessing antimicrobial prescribing, resource utilization, and/or clinical outcomes associated with antimicrobial allergy labels were included. The search identified 560 unique citations, of which 7 articles met the inclusion criteria. One additional article identified by an expert in the field was also included. Four of the identified papers were limited to penicillin or other β-lactam allergies. Six studies noted differences in antibiotic selection between patients with allergy labels and those without such labels. Broader-spectrum or second-line agents (e.g., vancomycin, clindamycin, and fluoroquinolones) were more commonly prescribed for patients with penicillin allergy labels. Antibiotic therapy costs were significantly higher for patients with allergy labels than for those without. The impact of allergy labels on clinical outcomes was mixed. One study indicated a longer length of hospital stay, 2 studies reported higher readmission rates, and 1 study reported a higher rate of antibiotic-resistant organisms for patients with allergy labels. Most of the available literature is limited to penicillin or β-lactam allergy. The growing body of knowledge supports the concept that β-lactam allergy labels are not benign and that labelling in the absence of a true allergy has a negative effect on patient care. Allergy labelling appears to be associated with suboptimal antibiotic selection, greater treatment costs, prolonged length of stay, greater readmission rates, and higher prevalence of

Development of a functionalized coating for inhibition of marine corrosion and biofouling

Science.gov (United States)

Gittens, Jeanette Elizabeth

The financial loss incurred by corrosion of metals in the marine environment has led to a need to develop effective, economic and environmentally friendly methods of protection. Traditional methods of counteracting the development of surface biofilms and biofouling within aqueous environments have involved implementing chemical biocides, often with a deleterious effect on non-target organisms. Sol gel coating technology offers a convenient route for immobilizing functional additives, such as inhibitors or, in the case of this study, biologically active microorganisms. Paenibacillus polymyxa biofilms inhibit the corrosion of metal substrates and this strain has the advantage of forming endospores can withstand the solvent and acid concentrations required in sol-gel formulation. Encapsulation of viable P. polymyxa endospores within the sol-gel matrix allowed germination on exposure to nutrients, when germinating endospores and vegetative cells were seen after fluorescence microscopy to be distributed throughout the coating. Laboratory electrochemical impedance tests were used to characterize the corrosion behaviour of the endospore-containing (biotic) sol-gel coating in comparison to an abiotic (no endospores) sol-gel only coating and one containing non-viable (killed) endospores. The technology enabled manipulation of the sol-gel formulation and the method of application to produce biotic sol-gel with enhanced corrosion inhibition properties on aluminium alloy. Field trials in a marine environment confirmed the corrosion protecting properties of the biotic coating and that the biotic coatings inhibited macroscopic biofouling for at least 29 weeks relative to the controls without encapsulated live endospores. Production of polymyxin by the encapsulated bacteria, which was proposed as a mechanism by which they inhibit MIC, was less than 1 mug per ml and below the threshold of detection by liquid chromatography mass spectrometry and antimicrobial bioassay. Microcosm

Effect of antimicrobial on mechanical, barrier and optical properties of corn starch based self-supporting edible film

Directory of Open Access Journals (Sweden)

Tanima Chowdhury

2013-10-01

Full Text Available Antimicrobials like potassium sorbate, sodium propionate, and benzoic acid were incorporated in corn starch based formulation to investigate their effect on mechanical, water vapour barrier and optical properties of the developed self supporting edible film. The film was prepared by casting technique. When incorporated at 1.40% and above, potassium sorbate decreased the tensile strength (about 22% and increased the elongation (about 55% of control film; whereas, it increased the water vapour permeability by 15% only when added at 2.66%. At 2.66%, benzoic acid reduced the tensile strength by 24% and sodium propionate increased elongation by 17%. These two antimicrobials did not change the water vapour permeability. However, all the three antimicrobials adversely affected the optical properties by decreasing the whiteness index, increasing yellowness index, and reducing the surface gloss, with potassium sorbate showing the maximum effect. Among the three antimicrobials, sodium propionate appeared to be the best with minimum deterioration of film properties.

Antimicrobial stewardship: Strategies for a global response

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Jenny Grunwald

2014-01-01

Full Text Available The increasing antimicrobial resistance worldwide, combined with dwindling antimicrobial armamentarium, has resulted in a critical threat to the public health and safety of patients. To combat this hazard, antimicrobial stewardship programs (ASPs have emerged. Antimicrobial stewardship programs prevent or slow the emergence of antimicrobial resistance by coordinated interventions designed to optimize antimicrobial use to achieve the best clinical outcomes and limiting selective pressures that drive the emergence of resistance. This also reduces excessive costs attributable to suboptimal antimicrobial use. Even though an ideal effective ASP should incorporate more than one element simultaneously, it also requires a multidisciplinary team, which should include an infectious diseases physician, a clinical pharmacist with infectious diseases training, infection control professionals, hospital epidemiologist, a clinical microbiologist and an information specialist. However, for antimicrobial stewardship (AMS programs to be successful, they must address the specific needs of individual institutions, must be built on available resources, the limitations and advantages of each institution, and the available staffing and technological infrastructure.

Shielding effects of concrete and foam external pipeline coatings

International Nuclear Information System (INIS)

Barlo, T.J.; Werner, D.P.

1992-01-01

The research project began in July, 1986 and was completed in December, 1990. The objectives of the research were: To determine whether concrete and urethane foam-barrier coatings shield the pipe from cathodic-protection current, To determine whether the barrier coatings also effectively shield the pipe from the environment, thus reducing the need for cathodic protection, To determine what levels of cathodic protection will be required to overcome shielding, and To establish what types of barrier coatings are most compatible with obtaining adequate levels of cathodic protection. To achieve these objectives, laboratory experiments were conducted with five barrier coating materials. These materials were (1) 2-lb/ft 3 , closed-cell urethane foam, (2) 3-lb/ft 3 , closed-cell urethane foam, (3) concrete barrier material, (4) glass fiber-reinforced concrete barrier material, and (5) sand. The barrier materials, whole and intentionally cracked, were applied to the bare, FBE-coated, and tape-coated steel specimens. The specimens were tested in aqueous electrolytes at room temperature and 140 degree F with no protection, protection to -0.95 V, and overprotection to -1.2 V (Cu/CuSO 4 )

Effect of selective decontamination on antimicrobial resistance in intensive care units: a systematic review and meta-analysis.

Science.gov (United States)

Daneman, Nick; Sarwar, Syed; Fowler, Robert A; Cuthbertson, Brian H

2013-04-01

Many meta-analyses have shown reductions in infection rates and mortality associated with the use of selective digestive decontamination (SDD) or selective oropharyngeal decontamination (SOD) in intensive care units (ICUs). These interventions have not been widely implemented because of concerns that their use could lead to the development of antimicrobial resistance in pathogens. We aimed to assess the effect of SDD and SOD on antimicrobial resistance rates in patients in ICUs. We did a systematic review of the effect of SDD and SOD on the rates of colonisation or infection with antimicrobial-resistant pathogens in patients who were critically ill. We searched for studies using Medline, Embase, and Cochrane databases, with no limits by language, date of publication, study design, or study quality. We included all studies of selective decontamination that involved prophylactic application of topical non-absorbable antimicrobials to the stomach or oropharynx of patients in ICUs, with or without additional systemic antimicrobials. We excluded studies of interventions that used only antiseptic or biocide agents such as chlorhexidine, unless antimicrobials were also included in the regimen. We used the Mantel-Haenszel model with random effects to calculate pooled odds ratios. We analysed 64 unique studies of SDD and SOD in ICUs, of which 47 were randomised controlled trials and 35 included data for the detection of antimicrobial resistance. When comparing data for patients in intervention groups (those who received SDD or SOD) versus data for those in control groups (who received no intervention), we identified no difference in the prevalence of colonisation or infection with Gram-positive antimicrobial-resistant pathogens of interest, including meticillin-resistant Staphylococcus aureus (odds ratio 1·46, 95% CI 0·90-2·37) and vancomycin-resistant enterococci (0·63, 0·39-1·02). Among Gram-negative bacilli, we detected no difference in aminoglycoside-resistance (0

Nanostructures for delivery of natural antimicrobials in food.

Science.gov (United States)

Lopes, Nathalie Almeida; Brandelli, Adriano

2017-04-10

Natural antimicrobial compounds are a topic of utmost interest in food science due to the increased demand for safe and high-quality foods with minimal processing. The use of nanostructures is an interesting alternative to protect and delivery antimicrobials in food, also providing controlled release of natural compounds such as bacteriocins and antimicrobial proteins, and also for delivery of plant derived antimicrobials. A diversity of nanostructures are capable of trapping natural antimicrobials maintaining the stability of substances that are frequently sensitive to food processing and storage conditions. This article provides an overview on natural antimicrobials incorporated in nanostructures, showing an effective antimicrobial activity on a diversity of food spoilage and pathogenic microorganisms.

Antimicrobial activity of transition metal acid MoO3 prevents microbial growth on material surfaces

International Nuclear Information System (INIS)

Zollfrank, Cordt; Gutbrod, Kai; Wechsler, Peter; Guggenbichler, Josef Peter

2012-01-01

Serious infectious complications of patients in healthcare settings are often transmitted by materials and devices colonised by microorganisms (nosocomial infections). Current strategies to generate material surfaces with an antimicrobial activity suffer from the consumption of the antimicrobial agent and emerging multidrug-resistant pathogens amongst others. Consequently, materials surfaces exhibiting a permanent antimicrobial activity without the risk of generating resistant microorganisms are desirable. This publication reports on the extraordinary efficient antimicrobial properties of transition metal acids such as molybdic acid (H 2 MoO 4 ), which is based on molybdenum trioxide (MoO 3 ). The modification of various materials (e.g. polymers, metals) with MoO 3 particles or sol–gel derived coatings showed that the modified materials surfaces were practically free of microorganisms six hours after contamination with infectious agents. The antimicrobial activity is based on the formation of an acidic surface deteriorating cell growth and proliferation. The application of transition metal acids as antimicrobial surface agents is an innovative approach to prevent the dissemination of microorganisms in healthcare units and public environments. Highlights: ► The presented modifications of materials surfaces with MoO 3 are non-cytotoxic and decrease biofilm growth and bacteria transmission. ► The material is insensitive towards emerging resistances of bacteria. ► Strong potential to reduce spreading of infectious agents on inanimate surfaces.

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

Energy Technology Data Exchange (ETDEWEB)

Pérez-Díaz, Mario Alberto [Facultad de Ciencias Químicas, UASLP, Álvaro Obregón 64, San Luis Potosí (Mexico); Boegli, Laura; James, Garth [Center for Biofilm Engineering, Montana State University, Bozeman, MT (United States); Velasquillo, Cristina; Sánchez-Sánchez, Roberto [Laboratorio de Biotecnología, Instituto Nacional de Rehabilitación (Mexico); Martínez-Martínez, Rita-Elizabeth; Martínez-Castañón, Gabriel Alejandro [Facultad de Estomatología, Universidad Autónoma de San Luis Potosí (Mexico); Martinez-Gutierrez, Fidel, E-mail: fidel@uaslp.mx [Facultad de Ciencias Químicas, UASLP, Álvaro Obregón 64, San Luis Potosí (Mexico)

2015-10-01

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Electrodeposition, characterization, and antibacterial activity of zinc/silver particle composite coatings

Energy Technology Data Exchange (ETDEWEB)

Reyes-Vidal, Y.; Suarez-Rojas, R.; Ruiz, C.; Torres, J. [Center of Research and Technological Development in Electrochemistry (CIDETEQ), Parque Tecnológico Sanfandila, Pedro Escobedo, Querétaro, A.P.064, C.P.76703, Querétaro (Mexico); Ţălu, Ştefan [Technical University of Cluj-Napoca, Faculty of Mechanical Engineering, Department of AET, Discipline of Descriptive Geometry and Engineering Graphics, 103-105 B-dul Muncii St., Cluj-Napoca 400641 Cluj (Romania); Méndez, Alia [Centro de Química-ICUAP Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria Puebla, 72530 Puebla (Mexico); Trejo, G., E-mail: gtrejo@cideteq.mx [Center of Research and Technological Development in Electrochemistry (CIDETEQ), Parque Tecnológico Sanfandila, Pedro Escobedo, Querétaro, A.P.064, C.P.76703, Querétaro (Mexico)

2015-07-01

Highlights: • Zn/AgPs composites coatings were formed for electrodeposition. • CTAB promotes occlusion of silver particles in the coating. • Zn/AgPs coatings present very good antibacterial activity. - Abstract: Composite coatings consisting of zinc and silver particles (Zn/AgPs) with antibacterial activity were prepared using an electrodeposition technique. The morphology, composition, and structure of the Zn/AgPs composite coatings were analyzed using scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS), inductively coupled plasma (ICP) spectrometry, and X-ray diffraction (XRD). The antibacterial properties of the coatings against the microorganisms Escherichia coli as a model Gram-negative bacterium and Staphylococcus aureus as a model Gram-positive bacterium were studied quantitatively and qualitatively. The results revealed that the dispersant cetyltrimethylammonium bromide (CTAB) assisted in the formation of a stable suspension of Ag particles in the electrolytic bath for 24 h. Likewise, a high concentration of CTAB in the electrolytic bath promoted an increase in the number of Ag particles occluded in the Zn/AgPs coatings. The Zn/AgPs coatings that were obtained were compact, smooth, and shiny materials. Antimicrobial tests performed on the Zn/AgPs coatings revealed that the inhibition of bacterial growth after 30 min of contact time was between 91% and 98% when the AgPs content ranged from 4.3 to 14.0 mg cm{sup −3}.

Antitumour, Antimicrobial, Antioxidant and Antiacetylcholinesterase Effect of Ganoderma Lucidum Terpenoids and Polysaccharides: A Review

Directory of Open Access Journals (Sweden)

Darija Cör

2018-03-01

Full Text Available Ganoderma lucidum (Reishi is a popular medicinal mushroom and has been used in oriental medicine because of its promoting effects on health and life expectancy. G. lucidum contains various compounds with a high grade of biological activty, which increase the immunity and show antitumour, antimicrobial, anti-inflammatory, antioxidant and acetylcholinesterase inhibitory activity. Several of these substances belong to the triterpenoids and polysaccharides classes. Proteins, lipids, phenols, sterols, etc. are also present. In the present review, an extensive overview of the presence of antitumour, antimicrobial, antioxidant and antiacetylcholinesterase compounds in G. lucidum extracts will be given, along with an evaluation of their therapeutic effects.

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

Science.gov (United States)

Toroglu, Sevil

2007-07-01

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

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

Science.gov (United States)

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

2009-09-23

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

Silver-loaded chitosan coating as an integrated approach to face titanium implant-associated infections: analytical characterization and biological activity.